A single-component low-volatility microwave-absorbing adhesive and its preparation method and application

Abstract

The present invention provides a method for preparing a single-component, low-volatility absorbing adhesive, namely, preparing a two-component adhesive at high temperature, then mixing the adhesive at room temperature to prepare the absorbing adhesive, and finally storing the adhesive at low temperature. Component A contains only vinyl silicone oil and a catalyst, while component B contains vinyl silicone oil, hydrogenated silicone oil, and an inhibitor. This process ensures that the low-volatility adhesive is prepared first, eliminating the risk of cross-linking the adhesive at high temperatures. Furthermore, the process is simple and easy to operate. The two components are mixed at room temperature to prepare a single-component absorbing adhesive, resulting in an absorbing adhesive that can be stored for a long period of time. Furthermore, the single-component absorbing adhesive does not contain low-volatile organic compounds and is adaptable to various operating environments. Whether in prolonged high-temperature conditions or alternating hot and cold environments, it maintains a good operating state and does not experience oil seepage or silicon precipitation.

Description

Technical Field

[0001] The present invention relates to the technical field of wave-absorbing and shielding materials, and in particular to a single-component low-volatile wave-absorbing adhesive and a preparation method and application thereof. Background Art

[0002] With the continuous development of electromagnetic waves and communication technologies, electromagnetic interference and pollution are becoming increasingly serious. Electromagnetic wave shielding and absorbing materials are becoming increasingly widely used. Absorbing materials are functional materials that convert incident electromagnetic wave energy into heat, thereby reducing or eliminating electromagnetic interference. Absorbing materials are gaining increasing popularity due to their excellent ability to mitigate electromagnetic interference. Currently, absorbing materials used in consumer electronics and communications are primarily thin sheets. However, these materials are difficult to meet the requirements for sealing and bonding applications. Glue products with absorbing properties can provide excellent electromagnetic compatibility in many applications requiring sealing and preventing electromagnetic interference and leakage. Currently, most shielding adhesives on the market use epoxy or polyurethane materials. While epoxy resin adhesives offer high bond strength after curing, they are brittle and not resistant to drops or shocks. Polyurethane adhesives are not heat-resistant (long-term operating temperatures generally do not exceed 120°C). Most organic silicone adhesives use condensation-type silicone rubber, which cures in moisture. Condensation-type silicone rubber produces small volatile molecules during the curing reaction, making it unsuitable for use in applications requiring low volatility. Addition-type silicone rubber cures via a vinyl-hydrogen addition reaction, which produces no small volatile molecules and is resistant to high temperatures (generally 200°C for long-term use), but exhibits poor bonding strength.

[0003] Chinese invention patent CN 111117260A discloses a method for preparing a micro-crosslinked, single-component thermally conductive, absorbing gel. The method employs a gradual addition of vinyl silicone oil. Hydrogenated silicone oil and vinyl silicone oil are first semi-vulcanized to partially crosslink and prevent the formation of a large crosslinked network. Fillers and additives are then added, and finally, hydrogenated silicone oil and vinyl silicone oil are added for full vulcanization. This addresses the issue of the crosslinking degree between the hydrogenated silicone oil and vinyl silicone oil systems, preventing oil seepage and silicon precipitation during alternating hot and cold conditions. However, the absorbing gel prepared using this method still exhibits oil seepage when used under long-term high-temperature conditions. Furthermore, the preparation steps in this patent are complex and require high component addition requirements. The semi-vulcanization stage easily leads to full vulcanization, forming a large-scale crosslinked system. This makes incomplete vulcanization very likely after the final addition of hydrogenated silicone oil and vinyl silicone oil, resulting in substandard bonding performance. Chinese invention patent CN114958005A discloses a two-component energy-storage absorbing gel material and its preparation method. By mixing components A and B, a cross-linking reaction occurs, forming a spatial network structure. The primary purpose is to bind the added phase-change material microcapsules and functional absorbing powder within the resin system and secure them in a relatively constant position. The patent adds phase-change material microcapsules to absorb and store heat generated by the chip during operation, while the added absorbing powder attenuates and absorbs electromagnetic waves, addressing the thermal management of high-power chips in confined spaces. In other words, the technology primarily addresses the thermal conductivity of the absorbing gel and does not address the issues of volatilization analysis under the primary operating environment.

[0004] The above analysis demonstrates that no existing technology can address the high-temperature volatilization analysis proposed in this invention. Therefore, developing a single-component, low-volatility, high-bonding, and high-temperature resistant addition-type silicone rubber absorber is of great significance and has promising applications, particularly in thin-film electronic products. Summary of the Invention

[0005] In view of this, in order to solve the above problems, the present invention provides a one-component low-volatility radar-absorbing adhesive and its preparation method and application. The present invention adopts a preparation method of preparing a two-component adhesive at high temperature - mixing at room temperature - and storing at low temperature to obtain a radar-absorbing adhesive that can be stored for a long time. This process can first prepare an adhesive with low volatility, without worrying about the adhesive cross-linking at high temperature, and the process is simple and easy to operate.

[0006] To achieve the above objectives, the present invention provides a method for preparing a single-component, low-volatility radar-absorbing adhesive. The method utilizes a two-component adhesive composition prepared at high temperature, mixed at room temperature, and then stored at low temperature, resulting in a long-term storable radar-absorbing adhesive. The two-component adhesive composition comprises a component A mixed adhesive and a component B mixed adhesive, wherein component A contains vinyl silicone oil and a catalyst, and component B mixed adhesive contains vinyl silicone oil, hydrogenated silicone oil, and an inhibitor. The two components A and B are mixed and stirred at room temperature to produce the radar-absorbing adhesive. This process ensures the low-volatility adhesive is prepared first, eliminating the risk of cross-linking at high temperatures. Furthermore, the process is simple and easy to operate. The two components are then mixed at room temperature to produce a single-component radar-absorbing adhesive, which is then stored at low temperature to provide a long-term storable radar-absorbing adhesive.

[0007] Specifically, the specific steps for preparing the above-mentioned single-component low-volatility absorbing adhesive include:

[0008] -Preparing a mixed rubber compound of component A; mixing vinyl silicone oil, absorbent, coupling agent, reinforcing agent, tackifier and catalyst, and stirring at high temperature and vacuum to obtain the mixed rubber compound of component A;

[0009] -Preparing component B rubber; stirring vinyl silicone oil, hydrogen silicone oil, coupling agent, absorbent and inhibitor at high temperature and vacuum to obtain component B mixed rubber;

[0010] -Preparing an absorbing adhesive; cooling the mixed adhesive material of component A and the mixed adhesive material of component B to room temperature, respectively, and then cooling with water and stirring in a vacuum until uniformly stirred to obtain the absorbing adhesive;

[0011] The mass ratio of the vinyl silicone oil in the mixed rubber material of component A to the vinyl silicone oil in the mixed rubber material of component B is 1:1; the mass ratio of the hydrogenated silicone oil to the vinyl silicone oil in the mixed rubber material of component B is 1:3 to 1:8;

[0012] The prepared wave-absorbing adhesive is stored at a temperature below -5°C.

[0013] The microwave-absorbing adhesive prepared by the present invention can be cured at room temperature or under heating conditions, and needs to be stored at low temperature for long-term storage.

[0014] Preferably, in the mixed rubber material of component A, by mass percentage, vinyl silicone oil 5% to 45%, absorbent 50% to 90%, coupling agent 0.1% to 1%, reinforcing agent 1% to 5%, tackifier 0.1% to 1%, and catalyst 0.05% to 0.5%.

[0015] Preferably, in terms of mass percentage, the mixed rubber material of component B comprises 5% to 45% vinyl silicone oil, 0.5% to 5% hydrogenated silicone oil, 0.1% to 1% coupling agent, 50% to 90% absorbent and 0.05% to 0.1% inhibitor.

[0016] Preferably, the vinyl silicone oil comprises vinyl-terminated silicone oil and high-vinyl silicone oil; the viscosity of the vinyl-terminated silicone oil is 100-10,000 mPa·s, and the vinyl content is 0.1-1.2%; the viscosity of the high-vinyl silicone oil is 100-20,000 mPa·s, and the vinyl content is 0.5-20%.

[0017] Preferably, the active hydrogen group content in the base-containing silicone oil is 0.01 to 1.40%.

[0018] Preferably, the process conditions of high-temperature vacuum stirring include: vacuum conditions of -0.05 to 0.1 MPa, temperature of 80 to 150°C; water-cooled vacuum stirring includes: vacuum conditions of -0.05 to 0.1 MPa, stirring time of 30 to 180 minutes, and water-cooled stirring temperature of 10 to 25°C.

[0019] Preferably, the absorbent comprises one or more of an iron-silicon-aluminum absorbent, an iron-silicon absorbent, a carbonyl iron powder absorbent, an iron-nickel absorbent, an iron-silicon-chromium absorbent, and a ferrite absorbent.

[0020] Preferably, the inhibitor comprises one of an alkynol compound, an amide compound and a maleate compound.

[0021] The alkynol compound is at least one of ethynylcyclohexanol, 3,5-dimethyl-1-hexyn-3-ol, 3,6-dimethyl-1-heptyn-3-ol, and 3,7,11-trimethyldodecyn-3-ol.

[0022] Preferably, the coupling agent comprises one of γ-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane, vinyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, and hexadecyltriethoxysilane.

[0023] Preferably, the adhesion promoter comprises one of organosilane, siloxane, silicone resin, titanate, boric acid or boron-containing compounds.

[0024] Preferably, the catalyst comprises a Custer catalyst.

[0025] The absorbing adhesive prepared by the above technical solution has a uniform cross-linked network structure, maintains a gel-state structure, has strong bonding properties, and has a wide range of uses. It is especially suitable for thin electronic products under long-term high temperature conditions. It can be applied not only to electronic components, but also to various fields such as PCB circuit boards, information and communication electronic products, especially for specific scenarios such as electronic products with a high degree of integration and insufficient space, optical modules, and optical fiber communications.

[0026] Principle of the invention:

[0027] The present invention prepares a two-component adhesive at high temperature. Component A contains only vinyl silicone oil and a catalyst, while component B contains vinyl silicone oil, hydrogenated silicone oil, and an inhibitor. This process ensures the initial preparation of a low-volatility adhesive, eliminating the risk of crosslinking at high temperatures. Furthermore, the process is simple and easy to operate. The two components are then mixed at room temperature to produce a single-component absorbing adhesive, which is then stored at low temperatures. This allows for long-term storage of the adhesive.

[0028] The beneficial technical effects obtained by the present invention are:

[0029] The technical solution of the present invention has simple process, simple raw materials, low energy consumption and is suitable for mass production and promotion.

[0030] The beneficial technical effects obtained by the present invention are:

[0031] 1. The radar-absorbing adhesive prepared by the technical solution of the present invention first prepares low-volatile component A and component B adhesives under high temperature conditions, and then prepares a single-component radar-absorbing adhesive at room temperature. The single-component system does not contain low-volatile organic compounds and can adapt to various usage environments. Whether it is long-term high temperature conditions or alternating hot and cold environments, it can maintain a good usage state and will not cause oil leakage or silicon precipitation.

[0032] 2. The wave-absorbing adhesive prepared by the technical solution of the present invention can have excellent bonding strength and mechanical strength while taking into account its attenuation performance, and has excellent comprehensive performance.

[0033] 3. The technical solution of the present invention has simple process, simple raw materials, low energy consumption, and is suitable for mass production and promotion. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0035] The present invention provides a method for preparing a single-component low-volatility radar-absorbing adhesive. The method comprises the following steps: preparing a two-component adhesive at high temperature, mixing at room temperature, and storing at low temperature to obtain a radar-absorbing adhesive capable of long-term storage and low volatility. The specific steps include:

[0036] -Preparing a mixed rubber compound of component A; mixing vinyl silicone oil, absorbent, coupling agent, reinforcing agent, tackifier and catalyst, and stirring under high temperature and vacuum conditions to obtain a mixed rubber compound of component A;

[0037] -Preparing component B rubber; stirring vinyl silicone oil, hydrogen silicone oil, coupling agent, absorbent and inhibitor under high temperature and vacuum conditions to obtain component B mixed rubber;

[0038] -Preparing an absorbing adhesive; cooling the mixed adhesive material of component A and the mixed adhesive material of component B to room temperature, respectively, and then stirring them in water under vacuum to obtain the absorbing adhesive;

[0039] The mass ratio of the vinyl silicone oil in the mixed rubber material of component A to the mixed rubber material of component B is 1:1; the mass ratio of the hydrogenated silicone oil to the vinyl silicone oil in the mixed rubber material of component B is 1:3 to 1:8;

[0040] The prepared wave-absorbing adhesive is stored at a temperature below -5°C.

[0041] In some preferred embodiments, the vinyl silicone oil comprises vinyl-terminated silicone oil and high-vinyl silicone oil; the viscosity of the vinyl-terminated silicone oil is 100-10,000 mPa·s, and the vinyl content is 0.1-1.2%; the viscosity of the high-vinyl silicone oil is 100-20,000 mPa·s, and the vinyl content is 0.5-20%.

[0042] In some preferred embodiments, the active hydrogen group content in the base-containing silicone oil is 0.01 to 1.40%.

[0043] In some preferred embodiments, the process conditions of high-temperature vacuum stirring include: vacuum conditions of -0.05 to 0.1 MPa, temperature of 80 to 150°C; water-cooled vacuum stirring includes: vacuum conditions of -0.05 to 0.1 MPa, stirring time of 30 to 180 minutes, and water-cooled stirring temperature of 10 to 25°C.

[0044] In some preferred embodiments, the absorbent includes one or more of an iron-silicon-aluminum absorbent, an iron-silicon absorbent, a carbonyl iron powder absorbent, an iron-nickel absorbent, an iron-silicon-chromium absorbent, and a ferrite absorbent.

[0045] In some preferred embodiments, the inhibitor comprises one of an alkynol compound, an amide compound, and a maleate compound.

[0046] In some preferred embodiments, the coupling agent comprises one of γ-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane, vinyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, and hexadecyltriethoxysilane.

[0047] In some preferred embodiments, the adhesion promoter comprises one of organosilane, siloxane, silicone resin, titanate, boric acid or boron-containing compounds.

[0048] In some preferred embodiments, the catalyst comprises a Custer catalyst.

[0049] The technical solutions and effects of the present invention are further illustrated below through specific embodiments.

[0050] Example 1

[0051] First, weigh the mixed rubber material of component A according to the proportions in Table 1: vinyl silicone oil, absorbent, coupling agent, tackifier, reinforcing agent and catalyst, add them into a stirring tank, high temperature 120℃, vacuum degree -0.09MPa, stir for 60 minutes and then take out.

[0052] Then, vinyl silicone oil, hydrogenated silicone oil, coupling agent, absorbent, reinforcing agent and inhibitor were weighed according to the proportion of the mixed rubber material of component B in Table 1 below, added into a stirring tank, heated to 120°C and vacuumed to -0.09 MPa, stirred for 60 minutes and then taken out.

[0053] After the two groups of materials are cooled to room temperature, they are mixed, and stirred for 60 minutes under water cooling (18° C.) with a vacuum degree of -0.09 MPa to obtain a wave-absorbing adhesive.

[0054] Finally, inject the absorbing glue into the tube and store it in a freezer at -5℃.

[0055] Table 1 Added raw material ingredients in Example 1

[0056]

[0057] Example 2

[0058] First, weigh the vinyl silicone oil, absorbent, coupling agent, tackifier, reinforcing agent and catalyst in the proportion of component A according to Table 2, add them to the stirring tank, heat at 110°C, vacuum at -0.1MPa, stir for 80 minutes and take out; then weigh the vinyl silicone oil, hydrogenated silicone oil, coupling agent, absorbent, reinforcing agent and inhibitor in the proportion of Table 2, add them to the stirring tank, heat at 110°C, vacuum at -0.1MPa, stir for 80 minutes and take out; after the two groups of materials are cooled to room temperature, mix the materials, water-cool (18°C), vacuum at -0.1MPa and stir for 80 minutes, finally, inject the absorbing glue into the hose and store it in a frozen state at -5°C.

[0059] Table 2 Added raw material ingredients in Example 2

[0060]

[0061] The difference between this embodiment and embodiment 1 is that the amount of the tackifier is reduced.

[0062] Example 3

[0063] First, weigh vinyl silicone oil, absorbent, coupling agent, tackifier, reinforcing agent and catalyst in a certain proportion according to Table 3, add them to a stirring tank, heat to 120°C, vacuum to -0.1MPa, stir for 90 minutes and take out; then weigh vinyl silicone oil, hydrogenated silicone oil, coupling agent, absorbent, reinforcing agent and inhibitor in a certain proportion according to Table 3, add them to a stirring tank, heat to 120°C, vacuum to -0.1MPa, stir for 90 minutes and take out; after the two groups of materials are cooled to room temperature, mix the materials, water-cool (20°C), vacuum to -0.1MPa and stir for 90 minutes, finally, inject the absorbing glue into the hose and store it in a frozen state at -5°C.

[0064] Table 3 Added raw material ingredients in Example 3

[0065]

[0066] The difference between this embodiment and embodiment 1 is that the amount of the tackifier is increased.

[0067] Example 4

[0068] First, weigh vinyl silicone oil, absorbent, coupling agent, tackifier, reinforcing agent and catalyst in a certain proportion according to Table 4, add them to a stirring tank, heat to 120°C, vacuum to -0.1MPa, stir for 100 minutes and take out; then weigh vinyl silicone oil, hydrogenated silicone oil, coupling agent, absorbent, reinforcing agent and inhibitor in a certain proportion according to Table 4, add them to a stirring tank, heat to 120°C, vacuum to -0.1MPa, stir for 120 minutes and take out; after the two groups of materials are cooled to room temperature, mix the materials, water-cool (15°C), vacuum to -0.1MPa and stir for 120 minutes, finally, inject the absorbing glue into the hose and store it in a frozen state at -5°C.

[0069] Table 4 Added raw material ingredients in Example 4

[0070]

[0071]

[0072] The difference between this embodiment and embodiment 1 is that the silane coupling agent is replaced.

[0073] Example 5

[0074] First, weigh the mixed rubber material of component A according to the proportions in Table 5: vinyl silicone oil, absorbent, coupling agent, tackifier, reinforcing agent and catalyst, add them into a stirring tank, high temperature 120℃, vacuum degree -0.09MPa, stir for 60 minutes and then take out.

[0075] Then, vinyl silicone oil, hydrogenated silicone oil, coupling agent, absorbent, reinforcing agent and inhibitor were weighed according to the proportion of the mixed rubber material of component B in Table 5, added into the mixing tank, heated to 120°C and vacuumed to -0.09 MPa, stirred for 60 minutes and then taken out.

[0076] After the two groups of materials are cooled to room temperature, they are mixed, and stirred for 60 minutes under water cooling (18° C.) with a vacuum degree of -0.09 MPa to obtain a wave-absorbing adhesive.

[0077] Finally, inject the absorbing glue into the tube and store it in a freezer at -5℃.

[0078] Table 5 Added raw material ingredients in Example 5

[0079]

[0080] The difference between this embodiment and embodiment 1 is that the amount of absorbent is increased.

[0081] Comparative Example 1

[0082] First, weigh the mixed rubber material of component A according to the proportions in Table 6: vinyl silicone oil, absorbent, coupling agent, tackifier, reinforcing agent and catalyst, add them into a stirring tank, high temperature 120℃, vacuum degree -0.09MPa, stir for 60 minutes and then take out.

[0083] Then, vinyl silicone oil, hydrogenated silicone oil, coupling agent, absorbent, reinforcing agent and inhibitor were weighed according to the proportion of the mixed rubber of component B in Table 6, added into a stirring tank, heated to 120°C and vacuumed to -0.09 MPa, stirred for 60 minutes and then taken out.

[0084] After the two groups of materials are cooled to room temperature, they are mixed, and stirred for 60 minutes under water cooling (18° C.) with a vacuum degree of -0.09 MPa to obtain a wave-absorbing adhesive.

[0085] Finally, inject the absorbing glue into the tube and store it in a freezer at -5℃.

[0086] Table 6 Added raw material ingredients in comparative example 1

[0087]

[0088] Compared with Example 1, the content of the tackifier in this comparative example is lower.

[0089] Comparative Example 2

[0090] First, weigh the mixed rubber material of component A according to the proportions in Table 7: vinyl silicone oil, absorbent, coupling agent, tackifier, reinforcing agent and catalyst, add them into a stirring tank, high temperature 120℃, vacuum degree -0.09MPa, stir for 60 minutes and then take out.

[0091] Then, vinyl silicone oil, hydrogenated silicone oil, coupling agent, absorbent, reinforcing agent and inhibitor were weighed according to the proportion of the mixed rubber of component B in Table 7, added into a stirring tank, heated to 120°C and vacuumed to -0.09 MPa, stirred for 60 minutes and then taken out.

[0092] After the two groups of materials are cooled to room temperature, they are mixed, and stirred for 60 minutes under water cooling (18° C.) with a vacuum degree of -0.09 MPa to obtain a wave-absorbing adhesive.

[0093] Finally, inject the absorbing glue into the tube and store it in a freezer at -5℃.

[0094] Table 7 Added raw material ingredients in Comparative Example 2

[0095]

[0096] Compared with Example 1, the absorbent content in this comparative example is higher.

[0097] The absorbing adhesives prepared in the above examples and control examples were extruded and cured at 85° C. for 3 h, and then tested for oil permeation, volatility, hardness, shear strength, tensile strength, and attenuation performance. The performance is shown in Table 8.

[0098] The test method for the performance of absorbing glue is as follows:

[0099] 1. Oil leakage test: Punch the cured absorbing film into a 30mm diameter disc. Place the disc on graph paper. Finally, place the sample and the graph paper in an oven at 130°C for 72 hours and observe the oil leakage.

[0100] 2. Volatility test: Punch the cured absorbing rubber sheet into a 10mm*10mm square sample, place the sample in a 10ml glass bottle, cover the bottle mouth with a glass sheet, and then place the glass bottle on a 100℃ heating table. After heating for 1000 hours, observe the volatility.

[0101] 3. Tensile strength test: Punch the cured film into standard size according to the national standard GB / T528-2009 to test the tensile strength.

[0102] 4. Shear strength test: According to the requirements of the national standard GB / T7124-2008, overlap the shear strength test samples of the absorbing glue and test the shear strength after the glue is cured.

[0103] 5. Hardness test: According to the requirements of the national standard GB / T531.1-2008, the cured absorbing film is stacked into a standard thickness to test the hardness.

[0104] 6. Absorption performance test: Punch the cured absorbing rubber sheet into a coaxial ring with an inner diameter of 3.04 and an outer diameter of 7mm. Then use a vector network analyzer to test the electromagnetic parameters and finally calculate the microwave attenuation performance of the absorbing rubber.

[0105] Table 8 Performance test table of embodiments and comparative examples

[0106]

[0107] The test results in Table 8 show that the tackifier dosage was adjusted in Examples 1-3 and Comparative Example 1. The tackifier primarily helps improve the bond strength of the absorbing adhesive to the bonding surface. Too low a dosage will not achieve optimal adhesion, while too high a dosage will reduce performance and may lead to volatilization of small molecule compounds. The product in Example 3 exhibits slight volatilization, while Comparative Example 1 no longer meets the requirements.

[0108] Example 1 and Example 4 use different silane coupling agents. Obviously, different coupling agents have different effects on improving the compatibility of powder and base rubber, resulting in differences in the mechanical properties of the rubber after curing. The performance of Example 1 is better than that of Example 4.

[0109] Examples 1, 5, and Comparative Example 2 used different amounts of absorbent. It can be seen that the absorbent can cause changes in the attenuation and mechanical properties of the absorbing adhesive. The attenuation coefficients of Comparative Example 2 were 65.2 @ 10 GHz and 93.7 @ 18 GHz, respectively. This is because a high absorbent content improves the attenuation performance of the absorbing adhesive. However, exceeding a certain absorbent content prevents the base adhesive from encapsulating the powder, resulting in a decrease in mechanical properties.

[0110] In summary, the absorbing adhesive prepared using the present invention can meet the requirements of long-term use under high-temperature conditions, with high bonding strength, excellent absorbing performance, and no precipitation of small molecule compounds. Furthermore, it remains stable even under conditions of large temperature fluctuations, such as alternating hot and cold temperatures, without oil seepage or silicon precipitation. In particular, the absorbing adhesive prepared using the technical solution of the present invention achieves excellent bonding and mechanical strength while also maintaining good attenuation performance.

[0111] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any variation, modification, replacement, integration, or parameter change to these embodiments, which is within the spirit and principles of the present invention and which achieves the same functionality through conventional substitutions, without departing from the principles and spirit of the present invention, falls within the scope of protection of the present invention.

Claims

1. A method for preparing a single-component low-volatility radar-absorbing adhesive, characterized in that: The wave-absorbing adhesive is obtained by adopting a preparation method of high-temperature preparation of a two-component adhesive material, room-temperature mixing, and low-temperature storage; The two-component rubber material comprises a mixed rubber material of component A and a mixed rubber material of component B, wherein the component A comprises vinyl silicone oil and a catalyst, and the component B mixed rubber material comprises vinyl silicone oil, hydrogen-containing silicone oil and an inhibitor. The mixed rubber material of component A and the mixed rubber material of component B are mixed and stirred at room temperature to obtain the radar-absorbing rubber; The specific steps include: -Preparing component A mixed rubber material; mixing vinyl silicone oil, absorbent, coupling agent, reinforcing agent, tackifier and catalyst, and stirring at high temperature and vacuum to obtain component A mixed rubber material; -Preparing component B rubber; vinyl silicone oil, hydrogen silicone oil, coupling agent, absorbent and inhibitor are stirred at high temperature and vacuum to obtain component B mixed rubber; -Preparing an absorbing adhesive; cooling the mixed adhesive material of component A and the mixed adhesive material of component B to room temperature, respectively, and then water-cooling and vacuum stirring to obtain the absorbing adhesive after stirring evenly; In terms of mass percentage, the mixed rubber material of component A comprises 5% to 45% of vinyl silicone oil, 50% to 90% of absorbent, 0.1% to 1% of coupling agent, 1% to 5% of reinforcing agent, 0.1% to 1% of tackifier, and 0.05% to 0.5% of catalyst; In terms of mass percentage, the mixed rubber material of component B comprises 5% to 45% of vinyl silicone oil, 0.5% to 5% of hydrogenated silicone oil, 0.1% to 1% of coupling agent, 50% to 90% of absorbent and 0.05% to 0.1% of inhibitor. The process conditions of high-temperature vacuum stirring include: vacuum condition of -0.05 to 0.1 MPa, temperature of 80 to 150°C; The water-cooled vacuum stirring comprises: vacuum conditions of -0.05 to 0.1 MPa, stirring time of 30 to 180 min, and water-cooled stirring temperature of 10 to 25° C.; The prepared wave-absorbing adhesive is stored at a temperature below -5°C.

2. The method for preparing a single-component low-volatility radar-absorbing adhesive according to claim 1, characterized in that: The mass ratio of the vinyl silicone oil in the A component mixed rubber material and the B component mixed rubber material is 1:

1.

3. The method for preparing a one-component low-volatility radar-absorbing adhesive according to claim 1, characterized in that: The absorbent includes one or more of an iron-silicon-aluminum absorbent, an iron-silicon absorbent, a carbonyl iron powder absorbent, an iron-nickel absorbent, an iron-silicon-chromium absorbent, and a ferrite absorbent.

4. The method for preparing a single-component low-volatility radar-absorbing adhesive according to claim 1, characterized in that: The inhibitor comprises one of an alkynol compound, an amide compound and a maleate compound.

5. The method for preparing a one-component low-volatility radar-absorbing adhesive according to claim 1, characterized in that: The coupling agent comprises one of γ-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane, vinyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane and hexadecyltriethoxysilane.

6. The method for preparing a single-component low-volatility radar-absorbing adhesive according to claim 1, characterized in that: The adhesion promoter comprises one of organic silane, siloxane, silicone resin, titanate, boric acid or boron-containing compounds.

7. The method for preparing a one-component low-volatility radar-absorbing adhesive according to claim 1, characterized in that: The catalyst comprises a Custer catalyst.

8. The method for preparing a one-component low-volatility radar-absorbing adhesive according to any one of claims 1 to 7, characterized in that: The vinyl silicone oil includes vinyl-terminated silicone oil and high-vinyl silicone oil; the viscosity of the vinyl-terminated silicone oil is 100-10,000 MPa·s, and the vinyl content is 0.1-1.2%; the viscosity of the high-vinyl silicone oil is 100-20,000 MPa·s, and the vinyl content is 0.5-20%.

9. The method for preparing a one-component low-volatility radar-absorbing adhesive according to claim 8, characterized in that: The hydrogen-containing silicone oil has an active hydrogen group content of 0.01 to 1.40%. In the mixed rubber material of component B, the mass ratio of the hydrogen-containing silicone oil to the vinyl silicone oil is 1:1 to 10.

10. A microwave-absorbing adhesive prepared according to the method for preparing a single-component low-volatility microwave-absorbing adhesive according to any one of claims 1 to 9.

11. Use of the single-component low-volatility absorbing adhesive prepared by the preparation method according to any one of claims 1 to 9 or the absorbing adhesive according to claim 10 in thin-sheet electronic products.

Images