Medium-temperature strain gauge patch adhesive and preparation method thereof

Abstract

The invention relates to the technical field of electronic packaging materials, and provides a medium-temperature strain gauge patch adhesive which comprises the following components in percentage by mass: 5-30% of an epoxy resin mixture; 5-30% of a phenolic resin mixture; 7-20% of a resin reinforced mixture; 35-60% of a solvent; 0-5% of a diluent; 5-10% of a curing agent; 0.1 to 2 percent of filler; 0-3% of an accelerant; 0-1% of a pigment; 0-1% of a coupling agent; 0-1% of a thixotropic agent; and 0.11-2.1% of an additive for mixing. By using the epoxy resin mixture, the phenolic resin mixture and other components in a specific proportion, the medium-temperature strain gauge patch adhesive can effectively reduce thermal deformation in a medium-temperature environment of 60-150 DEG C, thereby avoiding deviation and drifting of output resistance of a strain gauge, improving test precision and accuracy, enhancing stability in a high-temperature environment, and prolonging the service life of the medium-temperature strain gauge patch adhesive. And the device is suitable for a wider working temperature range.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic packaging materials, in particular to a medium-temperature strain gauge patch adhesive and a preparation method thereof. Background Art

[0002] As early as the 1930s, Ed Simmons of the California Institute of Technology and Arthur Ruge of the Massachusetts Institute of Technology independently discovered and invented resistance strain gauge technology. In 1936, Charles Kearns of Hamilton Standard fabricated the first resistance strain gauge for use in mechanical testing of propeller blades. Since then, resistance strain gauge technology and products have entered a period of rapid development. Resistance strain gauges have not only evolved and been optimized from the original wire-wound type to the foil type of today, but have also made significant progress in strain gauge grid design, metal foil materials, substrate materials, fabrication processes, and theoretical mechanical analysis. This has led to increasingly higher accuracy, larger measurement ranges, and a wider variety of applications for resistance strain gauges. Today, resistance strain gauges remain a core component for all mechanical and deformation testing and monitoring in the industrial sector. This is particularly evident with the development of the Internet of Things and the development of more strain gauge application scenarios, which has led to an even wider range of applications for resistance strain gauges.

[0003] Generally speaking, a resistance strain gauge consists of a sensitive grid, leads, adhesive, substrate, and cover layer. The resistance strain gauge is bonded to the surface of an elastomer or component being measured using adhesive. When the elastomer or component is subjected to a load, the slight deformation (elongation or contraction) of the surface causes the strain gauge's sensitive grid to deform, causing the gauge's resistance to change. The rate of change, ΔR / R, is proportional to the strain (ε) of the component where the strain gauge is mounted. By measuring this resistance change, the strain and corresponding stress on the component's surface can be calculated using a formula.

[0004] Currently, the chip adhesives on the market are primarily based on epoxy resin systems, which can meet process requirements and operate normally from ~10°C to 60°C. However, as the operating temperature increases further, such as from 60°C to 150°C, these chip adhesives will experience varying degrees of thermal deformation, which in turn causes the strain gauge output resistance to deviate and drift, affecting test precision and accuracy. Therefore, a medium-temperature strain gauge chip adhesive and preparation method are needed. Summary of the Invention

[0005] In response to the shortcomings of the existing technology, the present invention provides a medium-temperature strain gauge patch adhesive and a preparation method, which solves the problem that the existing patch adhesive will undergo varying degrees of thermal deformation as the operating temperature exceeds the withstand temperature, thereby causing the strain gauge output resistance to deviate and drift.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0007] A medium-temperature strain gauge patch adhesive, the medium-temperature strain gauge patch adhesive is divided into the following quality percentages:

[0008] Epoxy resin mixture 5-30%;

[0009] Phenolic resin mixture 5-30%;

[0010] Resin reinforced mixture 7-20%;

[0011] Solvent 35-60%;

[0012] Diluent 0-5%;

[0013] Curing agent 5-10%;

[0014] Filler 0.1-2%;

[0015] Accelerator 0-3%;

[0016] Pigment 0-1%;

[0017] Coupling agent 0-1%;

[0018] Thixotropic agent 0-1%;

[0019] Mixing additives 0.11-2.1%;

[0020] The resin reinforcement mixture comprises the following mass percentage compositions: 5-10% silicon carbide, 1-5% liquid nitrile rubber, 0-5% calcium silicate and 0-5% silicon nitride;

[0021] The mixing additive comprises the following mass percentage compositions: 0-1% of defoaming agent and 0.1-1% of toughening agent.

[0022] Preferably, the medium-temperature strain gauge patch adhesive is composed of the following mass percentages: epoxy resin mixture 15%, phenolic resin mixture 20%, silicon carbide 8%, liquid nitrile rubber 3.4%, calcium silicate 2%, solvent 40%, diluent 1%, curing agent 8%, filler 0.5%, accelerator 1%, pigment 0.3%, coupling agent 0.05%, thixotropic agent 0.1%, defoaming agent 0.1%, toughening agent 0.5%, and antioxidant 0.05%.

[0023] Preferably, the medium-temperature strain gauge patch adhesive is composed of the following mass percentages: 5% epoxy resin mixture, 30% phenolic resin mixture, 10% silicon carbide, 5% liquid nitrile rubber, 1% calcium silicate, 35% solvent, 0.5% diluent, 10% curing agent, 0.1% filler, 3% accelerator, 0.09% pigment, 0.05% coupling agent, 0.05% thixotropic agent, 0.1% defoaming agent, 0.1% toughening agent, and 0.01% antioxidant.

[0024] Preferably, the medium-temperature strain gauge patch adhesive is composed of the following mass percentages: epoxy resin mixture 20%, phenolic resin mixture 15%, silicon carbide 5.4%, liquid nitrile rubber 3%, silicon nitride 2%, solvent 43%, diluent 1%, curing agent 6%, filler 1%, accelerator 2%, pigment 0.5%, coupling agent 0.3%, thixotropic agent 0.2%, defoaming agent 0.1%, and toughening agent 0.5%.

[0025] Preferably, the epoxy resin mixture is a mixture of a multifunctional glycidylamine epoxy resin, a bisphenol A glycidyl ether epoxy resin and a phenolic epoxy resin, the multifunctional glycidylamine epoxy resin is a mixture of any one or more of TDE85, MY721, MY510, and MY500, the bisphenol A glycidyl ether epoxy resin is a mixture of any one or more of epoxy resin E12, epoxy resin E20, epoxy resin E44, epoxy resin E51 or epoxy resins of similar structures, the phenolic epoxy resin is a mixture of any one or two of F44 or F51, and the phenolic resin mixture is a mixture of any one or more of thermosetting phenolic resin 2402, thermosetting phenolic resin 2408, thermosetting phenolic resin 201 or thermosetting phenolic resin 202.

[0026] Preferably, the toughening agent is any one of an epoxy-active toughening agent or polypropylene glycol, and the antioxidant is any one of antioxidant DLTP, antioxidant 164, and tert-butylhydroquinone.

[0027] Preferably, the curing agent is a mixture of any one or more of dicyandiamide (dicyandiamide), 4,4-diaminodiphenyl sulfone (DDS), diethyltoluenediamine, methyltetrahydrophthalic anhydride, and pyromellitic anhydride; the accelerator is a mixture of any one or more of 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-imidazole, and 1-benzyl-2-methylimidazole; the solvent is a mixture of any one or more of tetrahydrofuran, ethylene glycol dimethyl ether, ethylene glycol ethyl ether, and ethylene glycol monobutyl ether; and the diluent is a mixture of any one or more of butyl glycidyl ether, phenyl glycidyl ether, and vinyl cyclohexene dioxide.

[0028] Preferably, the filler is a mixture of any one or more of silicon dioxide with a diameter of 10 to 200 nm, sericite with a size of 2000 to 3000 mesh, talc with a size of 2000 to 2500 mesh, and calcium carbonate with a size of 2000 to 3000 mesh; the pigment is iron oxide blue, iron oxide red, or titanium white; and the coupling agent is a mixture of any one or more of a silane coupling agent, a titanate coupling agent, and a borate coupling agent.

[0029] Preferably, the thixotropic agent is a mixture of any one or more of fumed silica, organic bentonite, asbestos powder, and attapulgite powder, and the defoaming agent is any one of organic silicon defoaming agent, polyether defoaming agent, latex defoaming agent, and the like.

[0030] A method for preparing a medium-temperature strain gauge patch adhesive comprises the following steps:

[0031] Step 1: Mix the epoxy resin mixture, the phenolic resin mixture, the diluent, and the solvent according to the proportions, and stir them evenly at a temperature not higher than 60° C. to obtain component A1;

[0032] Step 2: Mix silicon carbide, liquid nitrile rubber, and any one of calcium silicate and silicon nitride according to proportion and stir evenly to obtain component A2;

[0033] Step 3: Mix component A1 with filler, pigment, toughening agent and thixotropic agent in proportion and stir evenly, then grind on a ball mill for not less than 3 hours to obtain component A3;

[0034] Step 4: Mix component A3, a coupling agent, and an antioxidant according to the proportions and stir evenly to obtain component A;

[0035] Step 5: Mix the curing agent, accelerator and solvent according to the proportion and stir evenly to obtain component B;

[0036] Step 6: Mix component A and component B according to the proportion, add defoaming agent, and then stir evenly to obtain the patch adhesive for medium-temperature strain gauge.

[0037] The present invention provides a medium-temperature strain gauge patch adhesive and a preparation method thereof. It has the following beneficial effects:

[0038] 1. The present invention uses a specific proportion of epoxy resin mixture, phenolic resin mixture and other ingredients to enable the medium-temperature strain gauge patch adhesive to effectively reduce thermal deformation in a medium temperature environment of 60°C to 150°C, thereby avoiding deviation and drift of the strain gauge output resistance, improving test precision and accuracy, enhancing stability in high temperature environments, and being suitable for a wider operating temperature range.

[0039] 2. The present invention adopts a batch mixing method, so that the main components can be stored and transported independently and mixed immediately before use, so that the patch adhesive maintains the integrity after mixing and molding, reducing aging caused by long-term storage. The addition of antioxidants reduces aging and degradation caused by the external high-temperature oxidative environment, further extending the storage and service life of the patch adhesive.

[0040] 3. After adding either silicon carbide or silicon nitride, the present invention improves the thermal conductivity of the patch adhesive, helps to quickly dissipate heat in a high-temperature environment, reduces the generation of thermal stress, and reduces the resistance of the patch adhesive to form a conductive path. The addition of liquid nitrile rubber and calcium silicate significantly improves the impact strength and toughness of the patch adhesive, enables the patch adhesive to absorb stress, prevents the expansion of cracks, and makes the adhesion of the patch adhesive stronger. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 The present invention is a flow chart of a method for preparing a medium-temperature strain gauge patch adhesive. DETAILED DESCRIPTION

[0042] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0043] An embodiment of the present invention provides a medium-temperature strain gauge patch adhesive. The quality percentage of the medium-temperature strain gauge patch adhesive is as follows:

[0044] 5-30% of the epoxy resin mixture is one of the main components, serving as a bonding and structural support, providing high bonding strength, good electrical insulation properties, and chemical corrosion resistance. The epoxy resin mixture is a mixture of a multifunctional glycidylamine epoxy resin, a bisphenol A glycidyl ether epoxy resin, and a novolac epoxy resin. The multifunctional glycidylamine epoxy resin is a mixture of any one or more of TDE85, MY721, MY510, and MY500. The bisphenol A glycidyl ether epoxy resin is a mixture of any one or more of epoxy resin E12, epoxy resin E20, epoxy resin E44, epoxy resin E51, or epoxy resins of similar structures. The novolac epoxy resin is a mixture of any one or two of F44 and F51.

[0045] 35-60% of the solvent is used to reduce the viscosity of the patch adhesive, extend the service life of the patch adhesive, and prevent it from curing prematurely. The solvent is a mixture of any one or more of tetrahydrofuran, ethylene glycol dimethyl ether, ethylene glycol ethyl ether, and ethylene glycol monobutyl ether;

[0046] 5-30% phenolic resin mixture, used to improve the heat resistance and mechanical strength of the patch adhesive. By mixing with the epoxy resin mixture, its stability in high temperature environments is enhanced. The phenolic resin mixture is a mixture of any one or more of thermosetting phenolic resin 2402, thermosetting phenolic resin 2408, thermosetting phenolic resin 201, or thermosetting phenolic resin 202.

[0047] Silicon carbide 5-10% has high chemical stability and usually does not react chemically with common solvents (such as alcohols, ketones, esters and other organic solvents). At room temperature, silicon carbide shows good stability to most acids and alkalis, thereby improving the corrosion resistance of the patch adhesive itself. The addition of silicon carbide improves the thermal conductivity of the patch adhesive composed of composite materials, which helps to quickly dissipate heat in high temperature environments, reduce the generation of thermal stress, and reduce the resistance of the patch adhesive to form a conductive path;

[0048] 1-5% liquid nitrile rubber, through reaction with epoxy resin, significantly improves the impact strength and toughness of epoxy resin, absorbs stress, prevents crack expansion, and thus improves the toughness of the material;

[0049] Calcium silicate 0-5% appropriately increases the bonding performance of the patch adhesive. The needle-like structure of calcium silicate further increases the toughness of the patch adhesive to reduce the generation and expansion of cracks;

[0050] Silicon nitride 0-5%. Silicon nitride can maintain relatively stable performance in high temperature environment and will not decompose rapidly or significantly reduce performance at high temperature like some organic materials;

[0051] 0-5% diluent, used to further reduce the viscosity of the patch adhesive, improve its fluidity and wettability, so that it can better infiltrate the surface of the adherend, thereby increasing the bonding strength. The diluent is a mixture of any one or more of butyl glycidyl ether, phenyl glycidyl ether, and vinyl cyclohexene dioxide;

[0052] 5-10% of a curing agent, used to cure the raw materials by heating or at room temperature, wherein the curing agent is a mixture of any one or more of dicyandiamide (dicyandiamide), 4,4-diaminodiphenyl sulfone (DDS), diethyltoluenediamine, methyltetrahydrophthalic anhydride, and pyromellitic anhydride;

[0053] The filler is 0.1-2%, which improves the electrical insulation performance, high temperature resistance and mechanical strength of the patch adhesive, and can also adjust its viscosity and shrinkage rate after curing. The filler is a mixture of any one or more of silicon dioxide with a diameter of 10-200nm, sericite with a size of 2000-3000 mesh, talc with a size of 2000-2500 mesh, and calcium carbonate with a size of 2000-3000 mesh;

[0054] 0.1-1% toughening agent to improve the flexibility and impact resistance of the patch adhesive, the toughening agent is any one of epoxy active toughening agent or polypropylene glycol;

[0055] 0.01-0.1% of an antioxidant, used to reduce aging degradation caused by an external high-temperature oxidative environment after the raw materials are mixed, wherein the antioxidant is any one of antioxidant DLTP, antioxidant 164, and tert-butylhydroquinone;

[0056] 0-3% accelerator, used to accelerate the curing reaction of the raw materials, shorten the curing time, and improve production efficiency. The accelerator is a mixture of any one or more of 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, and 1-benzyl-2-methylimidazole;

[0057] Pigment 0-1%, used to dye the patch adhesive to make it recognizable, the pigment is iron oxide blue, iron oxide red or titanium white pigment;

[0058] 0-1% coupling agent, used to improve the compatibility between filler and resin, and enhance the bonding strength and heat resistance of patch adhesive. The coupling agent is a mixture of any one or more of silane coupling agent, titanate coupling agent, and borate coupling agent.

[0059] 0-1% thixotropic agent is used to give the patch adhesive thixotropy, so that it maintains a high viscosity in a static state, and prevents the adhesive from stratification, precipitation and leakage. The thixotropic agent is a mixture of any one or more of fumed silica, organic bentonite, asbestos powder, and attapulgite powder;

[0060] Defoaming agent 0-1% is used to eliminate air bubbles that penetrate into the mixed raw materials during the mixing process before the raw materials are mixed and allowed to stand and solidify. The defoaming agent can be any one of the defoaming agents such as silicone defoaming agent, polyether defoaming agent, latex defoaming agent, etc.

[0061] Please see the attached Figure 1 Based on the medium-temperature strain gauge patch provided above, as another aspect of the present application, a method for preparing a medium-temperature strain gauge patch adhesive comprises the following steps:

[0062] Step 1: Mix the epoxy resin mixture, the phenolic resin mixture, the diluent, and the solvent according to the proportions, and stir them evenly at a temperature not higher than 60° C. to obtain component A1;

[0063] Step 2: Mix silicon carbide, liquid nitrile rubber, and any one of calcium silicate and silicon nitride according to proportion and stir evenly to obtain component A2;

[0064] Step 3: Mix component A1 with filler, pigment, toughening agent and thixotropic agent in proportion and stir evenly, then grind on a ball mill for not less than 3 hours to obtain component A3;

[0065] Step 4: Mix component A3, a coupling agent, and an antioxidant according to the proportions and stir evenly to obtain component A;

[0066] Step 5: Mix the curing agent, accelerator and solvent according to the proportion and stir evenly to obtain component B;

[0067] Step 6: Mix component A and component B according to the proportion and add defoaming agent, then stir evenly to obtain patch adhesive for medium-temperature strain gauge. Let it stand for at least 48 hours before use.

[0068] Among them, component A obtained in step 4 and component B obtained in step 5 can be stored and transported separately and mixed immediately before use. Among them, component A containing an antioxidant can, with the assistance of the antioxidant, reduce the external high-temperature oxidation effect of component A with resin as the main component, thereby extending the storage time and reducing aging caused by storage.

[0069] Example 1:

[0070] A medium-temperature strain gauge patch adhesive comprises the following components by weight: 15% of an epoxy resin mixture, 20% of a phenolic resin mixture, 8% of silicon carbide, 3.4% of liquid nitrile rubber, 2% of calcium silicate, 40% of a solvent, 1% of a diluent, 8% of a curing agent, 0.5% of a filler, 1% of an accelerator, 0.3% of a pigment, 0.05% of a coupling agent, 0.1% of a thixotropic agent, 0.1% of a defoaming agent, 0.5% of a toughening agent, and 0.05% of an antioxidant.

[0071] Example 2:

[0072] A medium-temperature strain gauge patch adhesive comprises the following components by weight: 5% of an epoxy resin mixture, 30% of a phenolic resin mixture, 10% of silicon carbide, 5% of liquid nitrile rubber, 1% of calcium silicate, 35% of a solvent, 0.5% of a diluent, 10% of a curing agent, 0.1% of a filler, 3% of an accelerator, 0.09% of a pigment, 0.05% of a coupling agent, 0.05% of a thixotropic agent, 0.1% of a defoaming agent, 0.1% of a toughening agent, and 0.01% of an antioxidant.

[0073] Example 3:

[0074] A medium-temperature strain gauge patch adhesive comprises the following components by weight: 20% of an epoxy resin mixture, 15% of a phenolic resin mixture, 5.4% of silicon carbide, 3% of liquid nitrile rubber, 2% of silicon nitride, 43% of a solvent, 1% of a diluent, 6% of a curing agent, 1% of a filler, 2% of an accelerator, 0.5% of a pigment, 0.3% of a coupling agent, 0.2% of a thixotropic agent, 0.1% of a defoaming agent, and 0.5% of a toughening agent.

[0075] Experimental example:

[0076] Based on the mass percentage compositions provided in Example 1, Example 2, and Example 3, three molding experiments and index tests of medium-temperature strain gauge patch adhesives were conducted.

[0077] The molding test data are as follows:

[0078] Example 1 Example 2 Example 3 Curing temperature / time 155℃ / 3 hours 160℃ / 2.5 hours 170℃ / 2 hours Pressurization pressure 0.5MPa 0.5MPa 0.5MPa Bubble defoaming time 20 minutes 20 minutes 20 minutes State after curing Light yellow film Light yellow film Light yellow film

[0079] The indicator test data is as follows:

[0080]

[0081] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A medium temperature strain gauge patch adhesive, characterized in that: The medium temperature strain gauge patch adhesive quality percentages are: Epoxy resin mixture 5-30%; Phenolic resin mixture 5-30%; Resin reinforced mixture 7-20%; Solvent 35-60%; Diluent 0-5%; Curing agent 5-10%; Filler 0.1-2%; Accelerator 0-3%; Pigment 0-1%; Coupling agent 0-1%; Thixotropic agent 0-1%; Mixing additives 0.11-2.1%; The resin reinforcement mixture comprises the following mass percentage compositions: 5-10% silicon carbide, 1-5% liquid nitrile rubber, 0-5% calcium silicate and 0-5% silicon nitride; The mixing additive comprises the following mass percentage compositions: 0-1% of defoaming agent, 0.1-1% of toughening agent and 0.01-0.1% of antioxidant.

2. The medium temperature strain gauge patch adhesive according to claim 1, characterized in that: The weight percentage composition of the medium-temperature strain gauge patch adhesive is as follows: 15% epoxy resin mixture, 20% phenolic resin mixture, 8% silicon carbide, 3.4% liquid nitrile rubber, 2% calcium silicate, 40% solvent, 1% diluent, 8% curing agent, 0.5% filler, 1% accelerator, 0.3% pigment, 0.05% coupling agent, 0.1% thixotropic agent, 0.1% defoaming agent, 0.5% toughening agent, and 0.05% antioxidant.

3. The medium temperature strain gauge patch adhesive according to claim 1, characterized in that: The weight percentage composition of the medium-temperature strain gauge patch adhesive is as follows: 5% epoxy resin mixture, 30% phenolic resin mixture, 10% silicon carbide, 5% liquid nitrile rubber, 1% calcium silicate, 35% solvent, 0.5% diluent, 10% curing agent, 0.1% filler, 3% accelerator, 0.09% pigment, 0.05% coupling agent, 0.05% thixotropic agent, 0.1% defoaming agent, 0.1% toughening agent, and 0.01% antioxidant.

4. The medium temperature strain gauge patch adhesive according to claim 1, characterized in that: The weight percentage composition of the medium-temperature strain gauge patch adhesive is as follows: 20% epoxy resin mixture, 15% phenolic resin mixture, 5.4% silicon carbide, 3% liquid nitrile rubber, 2% silicon nitride, 43% solvent, 1% diluent, 6% curing agent, 1% filler, 2% accelerator, 0.5% pigment, 0.3% coupling agent, 0.2% thixotropic agent, 0.1% defoaming agent, and 0.5% toughening agent.

5. The medium-temperature strain gauge patch adhesive according to any one of claims 1 to 4, characterized in that: The epoxy resin mixture is formed by mixing a multifunctional glycidylamine epoxy resin, a bisphenol A glycidyl ether epoxy resin and a phenolic epoxy resin. The multifunctional glycidylamine epoxy resin is a mixture of any one or more of TDE85, MY721, MY510, and MY500. The brand of the bisphenol A glycidyl ether epoxy resin is a mixture of any one or more of epoxy resin E12, epoxy resin E20, epoxy resin E44, epoxy resin E51, or epoxy resins of similar structures. The phenolic epoxy resin is a mixture of any one or two of F44 or F51. The phenolic resin mixture is a mixture of any one or more of thermosetting phenolic resin 2402, thermosetting phenolic resin 2408, thermosetting phenolic resin 201, or thermosetting phenolic resin 202.

6. The medium-temperature strain gauge patch adhesive according to any one of claims 1 to 4, characterized in that: The toughening agent is any one of epoxy active toughening agent or polypropylene glycol, and the antioxidant is any one of antioxidant DLTP, antioxidant 164, and tert-butylhydroquinone.

7. The medium-temperature strain gauge patch adhesive according to any one of claims 1 to 4, characterized in that: The curing agent is a mixture of any one or more of dicyandiamide, 4,4-diaminodiphenyl sulfone, diethyltoluenediamine, methyltetrahydrophthalic anhydride, and pyromellitic anhydride; the accelerator is a mixture of any one or more of 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, and 1-benzyl-2-methylimidazole; the solvent is a mixture of any one or more of tetrahydrofuran, ethylene glycol dimethyl ether, ethylene glycol ethyl ether, and ethylene glycol monobutyl ether; and the diluent is a mixture of any one or more of butyl glycidyl ether, phenyl glycidyl ether, and vinyl cyclohexene dioxide.

8. The medium-temperature strain gauge patch adhesive according to any one of claims 1 to 4, characterized in that: The filler is a mixture of any one or more of silicon dioxide with a diameter of 10 to 200 nm, sericite with a size of 2000 to 3000 mesh, talc with a size of 2000 to 2500 mesh, and calcium carbonate with a size of 2000 to 3000 mesh; the pigment is iron oxide blue, iron oxide red, or titanium white; and the coupling agent is a mixture of any one or more of a silane coupling agent, a titanate coupling agent, and a borate coupling agent.

9. The medium-temperature strain gauge patch adhesive according to any one of claims 1 to 4, characterized in that: The thixotropic agent is a mixture of any one or more of fumed silica, organic bentonite, asbestos powder, and attapulgite powder; the defoaming agent is any one of organic silicon defoaming agent, polyether defoaming agent, latex defoaming agent, and the like.

10. A method for preparing a medium-temperature strain gauge patch adhesive, using the medium-temperature strain gauge patch adhesive according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1: Mix the epoxy resin mixture, the phenolic resin mixture, the diluent, and the solvent according to the proportions, and stir them evenly at a temperature not higher than 60° C. to obtain component A1; Step 2: Mix silicon carbide, liquid nitrile rubber, and any one of calcium silicate and silicon nitride according to proportion and stir evenly to obtain component A2; Step 3: Mix component A1 with filler, pigment, toughening agent and thixotropic agent in proportion and stir evenly, then grind on a ball mill for not less than 3 hours to obtain component A3; Step 4: Mix component A3, a coupling agent, and an antioxidant according to the proportions and stir evenly to obtain component A; Step 5: Mix the curing agent, accelerator and solvent according to the proportion and stir evenly to obtain component B; Step 6: Mix component A and component B according to the proportion, add defoaming agent, and then stir evenly to obtain the patch adhesive for medium-temperature strain gauge.

Images