Microwave absorbing material and processing technology

Abstract

The invention relates to the technical field of microwave absorbing materials, in particular to a microwave absorbing material and a processing technology thereof.The processing technology comprises the steps that firstly, silicone rubber is taken according to the proportion and added into an internal mixer for internal mixing; then adding a wave-absorbing agent, a coupling agent, carbon powder and a flame retardant in proportion, adding a curing agent at the same time, and continuously mixing to obtain a base material for later use; taking out the base material, putting the base material on an open mill, calendaring the base material into a sheet, standing for 24 hours, and rolling by adopting a roller press to obtain a primary product of the microwave absorbing material; the microwave absorbing material finished product can be obtained by performing corona treatment on the microwave absorbing material primary product and pasting a double-faced adhesive tape, the prepared microwave absorbing material can absorb electromagnetic waves within the wave band of 18-40GHz and has the advantages of large broadband, low reflection loss and the like, and meanwhile, the problem that the extremely inert surface of a rubber absorbing material is poor in reflection loss is solved by adopting a corona technology. Therefore, the adhesive tape can be firmly attached to the double-faced adhesive tape.

Description

Technical Field

[0001] The present invention relates to the technical field of microwave absorbing materials, and in particular to a microwave absorbing material and a processing technology thereof. Background Art

[0002] With the rapid development of 5G advanced communication technology and radar detection technology, the problem of electromagnetic radiation has become increasingly serious, interfering with the normal operation of equipment, causing device performance degradation or even failure. Electromagnetic pollution can also have adverse effects on human health. Absorbing materials coated or attached to the surface of equipment and equipment can reduce or eliminate electromagnetic pollution problems such as electromagnetic radiation interference. Therefore, absorbing materials have been widely used in both civilian and military fields. New absorbing materials need to have strong absorbing ability, wide absorbing frequency band, light weight and excellent coating or attachment performance.

[0003] Rubber microwave absorbing materials can convert the absorbed microwave energy into other forms of energy (mainly heat energy). It mainly absorbs electromagnetic waves through the absorbent in the material, and then converts electromagnetic waves into heat energy. Rubber microwave absorbing materials are widely used in military and civilian fields. The types of rubber microwave absorbing materials mainly include dielectric loss absorbing materials, magnetic loss absorbing materials and magnetic-dielectric synergistic absorbing materials. Among them, magnetic loss absorbing materials, such as carbonyl iron (CI), have been widely regarded as absorbing materials with great research and application value due to their high magnetic permeability and saturation magnetization, but there are problems such as low absorption bandwidth and poor reflection loss, which seriously affect the application of absorbing materials. In addition, silicone rubber is an extremely inert surface material, and it is not firm to directly use double-sided tape to stick. Usually, it needs to be treated with silicone treatment agent (silicone rubber back adhesive treatment agent) to achieve a higher strength bonding effect.

[0004] In summary, the existing absorbing materials have the problems of low absorption bandwidth, poor reflection loss, and poor adhesion with double-sided tape when used. Summary of the invention

[0005] The purpose of the present invention is to provide a microwave absorbing material and a processing technology, aiming to solve the technical problems that the absorbing materials in the prior art have low absorption bandwidth, poor reflection loss, and poor adhesion with double-sided adhesive when used.

[0006] To achieve the above purpose, the present invention adopts a microwave absorbing material, which includes 600-1200 parts of silicone rubber, 1200-2000 parts of absorbing agent, 1.5 parts of coupling agent, 0-900 parts of carbon powder, 15 parts of curing agent and 0-22 parts of flame retardant.

[0007] The silicone rubber is a mixture of one or more of nitrile butadiene rubber, methyl vinyl silicone rubber and silicone compound rubber.

[0008] Wherein, the wave absorbing agent is a mixture of one or more of carbonyl iron, ferrite, and sendust.

[0009] Wherein, the coupling agent is a mixture of one or more of γ-(2,3-epoxypropoxy)propyltrimethoxysilane, vinyltriethoxysilane and vinyltrimethoxysilane.

[0010] Wherein, the curing agent is one of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and hydrogen-containing silicone oil or a mixture of the two.

[0011] The present invention also provides a microwave absorbing material processing process, which is used to process the microwave absorbing material as described above.

[0012] The steps include:

[0013] First, take silicone rubber in proportion and add it into an internal mixer for internal mixing;

[0014] Then, the absorber, coupling agent, carbon powder and flame retardant are added in proportion, and the curing agent is added and mixed continuously to obtain the base material for use;

[0015] The base material is taken out, placed on an open mill and rolled into a thin sheet, and then left to stand for 24 hours, and then rolled using a roller press to obtain a preliminary product of the microwave absorbing material;

[0016] The initial microwave absorbing material is subjected to corona treatment and affixed with double-sided tape to obtain a finished microwave absorbing material.

[0017] When the silicone rubber is added into the internal mixer for internal mixing, the speed is 30 r / min, the temperature is 35° C., and the internal mixing time is 10 min.

[0018] When the base material is rolled into thin sheets using an open mixing mill, the vulcanization temperature is 160° C., the pressure is 10 MPa, and the speed is 10 mm / s.

[0019] The invention discloses a microwave absorbing material and a processing technology. First, silicone rubber is added into a mixer in proportion for mixing; then, an absorbing agent, a coupling agent, carbon powder and a flame retardant are added in proportion, and mixing is continued to obtain a base material for standby use; the base material is taken out, placed on an open mixer, rolled into a thin sheet, and then left to stand for 24 hours, and then rolled by a roller press to obtain a preliminary microwave absorbing material; the preliminary microwave absorbing material is subjected to corona treatment, and double-sided adhesive tape is attached to obtain a finished microwave absorbing material. The microwave absorbing material prepared in this way can absorb electromagnetic waves in the 18-40 GHz band, and has the advantages of large bandwidth, low reflection loss and the like. Meanwhile, the corona technology is used to solve the extremely inert surface of the rubber absorbing material, so that the rubber absorbing material can be firmly attached to the double-sided adhesive tape, thereby solving the technical problems of low absorption bandwidth, poor reflection loss and poor adhesion to the double-sided adhesive tape in the absorbing material in the prior art when in use. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is a schematic diagram of the reflection loss test results of the products prepared in Examples 1 to 3 of the present invention. DETAILED DESCRIPTION

[0022] Embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0023] The invention provides a microwave absorbing material, which comprises 600-1200 parts of silicone rubber, 1200-2000 parts of absorbing agent, 1.5 parts of coupling agent, 0-900 parts of carbon powder, 15 parts of curing agent and 0-22 parts of flame retardant.

[0024] The silicone rubber is a mixture of one or more of nitrile rubber, methyl vinyl silicone rubber and silicone compound rubber.

[0025] The wave absorbing agent is a mixture of one or more of carbonyl iron, ferrite, and sendust.

[0026] The coupling agent is a mixture of one or more of γ-(2,3-epoxypropoxy)propyltrimethoxysilane, vinyltriethoxysilane and vinyltrimethoxysilane.

[0027] The curing agent is one of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and hydrogen-containing silicone oil or a mixture of the two.

[0028] The present invention also provides a microwave absorbing material processing process, which is used to process the microwave absorbing material as described above.

[0029] The steps include:

[0030] S101, firstly, adding silicone rubber in proportion into an internal mixer for internal mixing;

[0031] According to this specific implementation mode, when the silicone rubber is added into the internal mixer for internal mixing, the rotation speed is 30 r / min, the temperature is 35° C., and the internal mixing time is 10 min.

[0032] S102, then adding the absorber, coupling agent, carbon powder and flame retardant in proportion, and adding the curing agent and continuing to mix to obtain the base material for use;

[0033] S103, taking out the base material, placing it on an open mill and rolling it into a thin sheet, then letting it stand for 24 hours, and then rolling it with a roller press to obtain a preliminary product of the microwave absorbing material;

[0034] According to this specific implementation method, when the base material is rolled into a thin sheet using an open mill, the vulcanization temperature is 160° C., the pressure is 10 MPa, and the speed is 10 mm / s.

[0035] S104, performing corona treatment on the initial microwave absorbing material, and affixing double-sided tape thereon to obtain a finished microwave absorbing material.

[0036] A microwave absorbing material and processing technology of the present embodiment are used. First, silicone rubber is added to a mixer in proportion for mixing; then an absorbent, a coupling agent, carbon powder and a flame retardant are added in proportion, and mixing is continued to obtain a base material for use; the base material is taken out, placed on an open mixer and rolled into a thin sheet, and then allowed to stand for 24 hours, and then rolled using a roller press to obtain a preliminary microwave absorbing material; the preliminary microwave absorbing material is subjected to corona treatment, and double-sided tape is attached to obtain a finished microwave absorbing material. The microwave absorbing material prepared in this way can absorb electromagnetic waves in the 18-40 GHz band, and has the advantages of large bandwidth, low reflection loss, etc. At the same time, the corona technology is used to solve the extremely inert surface of the rubber absorbing material, so that it can be firmly attached to the double-sided tape, thereby solving the technical problems of low absorption bandwidth, poor reflection loss and poor adhesion to the double-sided tape in the absorbing material in the prior art when in use.

[0037] Embodiment 1:

[0038] In this embodiment, the microwave absorbing material is prepared as follows:

[0039] 360 parts of silicone rubber and 240 parts of methyl vinyl silicone rubber were mixed in an internal mixer at a speed of 30 r / min and a temperature of 35°C for 10 minutes.

[0040] Then, 2000 parts of carbonyl iron powder, 1.5 parts of γ-(2,3-epoxypropoxy)propyltrimethoxysilane and 11 parts of flame retardant were added and kneaded for 20 minutes, and then 900 parts of carbon powder and 11 parts of flame retardant were added and kneaded for 20 minutes, and then 15 parts of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane were added and kneaded for 30 minutes, and the kneading was terminated;

[0041] The mixed base material was taken out and placed on an open mill for calendering (calendering parameters: 35°C, speed 4mm / s) to produce a sheet with a thickness of 1mm. After being parked for 24 hours, it was cured on a roller press with a vulcanization temperature of 160°C, a pressure of 10MPa, and a speed of 10mm / s. The sample reflection loss was tested using the bow method. Finally, the surface of the absorbing material was corona treated with a current of 40A and double-sided adhesive was applied on a backing machine.

[0042] Embodiment 2:

[0043] In this embodiment, the microwave absorbing material is prepared as follows:

[0044] Put 1200 parts of silicone rubber in a mixer at a speed of 30r / min and a temperature of 35°C for 10 minutes;

[0045] Then, 1200 parts of carbonyl iron powder and 1.5 parts of γ-(2,3-epoxypropoxy)propyltrimethoxysilane were added and kneaded for 20 minutes, and then 15 parts of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane were added and kneaded for 30 minutes, and the kneading was terminated;

[0046] After that, the mixed base material was taken out and placed on an open mill for calendering (calendering parameters: 35°C, speed 4mm / s), and a sheet with a thickness of 1mm was produced. After being parked for 24 hours, it was cured on a roller press with a vulcanization temperature of 160°C, a pressure of 10MPa, and a speed of 10mm / s. The sample reflection loss was tested using the bow method. Finally, the surface of the absorbing material was corona treated with a current of 40A and double-sided adhesive was applied on a backing machine.

[0047] Embodiment 3:

[0048] In this embodiment, the microwave absorbing material is prepared as follows:

[0049] 864 parts of silicone rubber were mixed in an internal mixer at a speed of 30 r / min and a temperature of 35°C for 10 minutes;

[0050] Then, 1800 parts of carbonyl iron powder and 1.5 parts of γ-(2,3-epoxypropoxy)propyltrimethoxysilane were added and kneaded for 20 minutes, 900 parts of carbon powder were added and kneaded for 20 minutes, and 15 parts of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane were added and kneaded for 30 minutes, and the kneading was terminated;

[0051] The mixed base material was taken out and placed on an open mill for calendering (calendering parameters: 35°C, speed 4mm / s) to produce a sheet with a thickness of 1mm. After being parked for 24 hours, it was cured on a roller press with a vulcanization temperature of 160°C, a pressure of 10MPa, and a speed of 10mm / s. The sample reflection loss was tested using the bow method. Finally, the surface of the absorbing material was corona treated with a current of 40A and double-sided adhesive was applied on a backing machine.

[0052] Figure 1 It is a schematic diagram of the reflection loss test results of the products prepared in Examples 1 to 3 of the present invention.

[0053] The wave absorbing performance test of the products prepared in Example 1 to Example 3 is shown in the following table:

[0054] Table 1: Wave absorbing properties of the products prepared in Examples 1 to 3

[0055]

[0056] What is disclosed above is only a preferred embodiment of the present invention, and it certainly cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A microwave absorbing material, characterized in that: The invention comprises 600-1200 parts of silicone rubber, 1200-2000 parts of wave absorbing agent, 1.5 parts of coupling agent, 0-900 parts of carbon powder, 15 parts of curing agent and 0-22 parts of flame retardant.

2. The microwave absorbing material according to claim 1, characterized in that: The silicone rubber is a mixture of one or more of nitrile rubber, methyl vinyl silicone rubber and silicone compound rubber.

3. The microwave absorbing material and processing technology according to claim 2, characterized in that: The wave absorbing agent is a mixture of one or more of carbonyl iron, ferrite, and sendust.

4. The microwave absorbing material and processing technology according to claim 3, characterized in that: The coupling agent is a mixture of one or more of γ-(2,3-epoxypropoxy)propyltrimethoxysilane, vinyltriethoxysilane and vinyltrimethoxysilane.

5. The microwave absorbing material and processing technology according to claim 4, characterized in that: The curing agent is one of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane and hydrogen-containing silicone oil or a mixture of the two.

6. A microwave absorbing material processing process, used for processing the microwave absorbing material according to claim 5, characterized in that: The steps include: First, take silicone rubber in proportion and add it into an internal mixer for internal mixing; Then, the absorber, coupling agent, carbon powder and flame retardant are added in proportion, and the curing agent is added and mixed continuously to obtain the base material for use; The base material is taken out, placed on an open mill and rolled into a thin sheet, and then left to stand for 24 hours, and then rolled using a roller press to obtain a preliminary product of the microwave absorbing material; The initial microwave absorbing material is subjected to corona treatment and affixed with double-sided tape to obtain a finished microwave absorbing material.

7. The microwave absorbing material processing process according to claim 6, characterized in that: When silicone rubber is added into the internal mixer for internal mixing, the speed is 30r / min, the temperature is 35°C, and the mixing time is 10min.

8. The microwave absorbing material processing process according to claim 7, characterized in that: When the base material is rolled into thin sheets using an open mill, the vulcanization temperature is 160°C, the pressure is 10 MPa, and the speed is 10 mm / s.

Images