A silicone wave-absorbing foamed caulking material and a preparation method thereof

Abstract

The application provides a silicone wave-absorbing foaming gap filling material and a preparation method thereof. The gap filling agent is composed of an A component and a B component. The A component comprises vinyl silicone oil, a wave-absorbing agent, hydroxyl silicone oil, a platinum catalyst, white carbon black and a liquid flame retardant. The B component comprises vinyl silicone oil, hydrogen-containing silicone oil, a wave-absorbing agent, phenyl hydrogen-containing silicone resin, white carbon black and an inhibitor. The wave-absorbing agent is a multi-layer material obtained by coating an amino acid layer on the surface of a metal oxide and coating a silane coupling agent layer outside the amino acid layer. The material has low density, uniform pores, low water absorption and high magnetic permeability.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials, specifically relating to an organosilicon microwave absorbing foam sealant and its preparation method. Background Technology

[0002] Microwave-absorbing materials, as excellent materials for absorbing electromagnetic radiation and preventing electromagnetic interference, are used in specific application scenarios, especially with the development of 5G and the intelligence of new energy vehicles, leading to their consideration in more scenarios. Existing microwave-absorbing materials generally use silicone rubber, acrylic, polyurethane, and other base materials, made into sheet materials and applied to smooth interfaces. These materials have low absorber content, high hardness, high mechanical strength, and thermal conductivity, making them unsuitable for use in confined spaces and gaps. In particular, they suffer from drawbacks such as high density, poor shock resistance, and poor thermal insulation in certain situations.

[0003] By utilizing the foaming properties of silicone and filling it with microwave absorbing agents, microwave absorbing materials with temperature and weather resistance can be prepared, while also reducing material density to meet lightweight requirements. Therefore, silicone microwave absorbing foam materials are an excellent application in specific scenarios and possess good shock resistance and cushioning properties.

[0004] However, most silicone-based microwave absorbing materials on the market currently have low absorber content, making it difficult to achieve specific electromagnetic wave absorption capabilities. If the filler content is further increased, the density will inevitably increase, affecting practical use. Summary of the Invention

[0005] The purpose of this invention is to provide an organosilicon microwave absorbing sealant material, which has a high filling amount of microwave absorbing agent and a low density foam structure, thereby solving the problem of low filling amount and high density.

[0006] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows:

[0007] A two-component silicone foam microwave absorbing sealant, the sealant being composed of two components, A and B, wherein component A comprises the following raw materials in parts by weight:

[0008]

[0009] Component B comprises the following parts by weight of raw materials:

[0010]

[0011] The microwave absorbing agent is a multilayer material obtained by coating an amino acid layer on the surface of a metal oxide and then coating a silane coupling agent layer on the outside of the amino acid layer.

[0012] In this invention, the vinyl silicone oils of components A and B are low-viscosity vinyl silicone oils, preferably with a viscosity of 50-500 mPa·s.

[0013] In this invention, the microwave absorbing agents of components A and B are metal oxides, preferably ferrites and / or nickel oxides.

[0014] In this invention, the amino acid layers of the microwave absorbers in components A and B contain one or more of the following amino acids: alanine, valine, leucine, isoleucine, proline, glycine, tryptophan, and phenylalanine.

[0015] In this invention, the silane coupling agent of the microwave absorber in components A and B is preferably a trimethoxysilane containing a long-chain alkyl group.

[0016] In one embodiment, the preparation steps of the microwave absorbing agent are as follows: Take amino acids, metal oxides, and an aqueous solution of tetrabutyl titanate, mix them evenly using a high-speed mixer, heat, stir at high speed, and cool to obtain a microwave absorbing agent coated with an amino acid layer. Dissolve a coupling agent in an aqueous ethanol solution, stir evenly, then atomize it to fully contact the microwave absorbing agent containing the amino acid layer, which is being stirred at high speed. Heat the solution until it is used up, continue stirring, continue heating and stirring, and cool to obtain a double-layer coated microwave absorbing agent.

[0017] In this invention, the hydroxyl silicone oil of component A is a single-terminated and / or double-terminated hydroxyl silicone oil.

[0018] In this invention, the platinum catalyst of component A is a Castells platinum catalyst.

[0019] In this invention, the liquid flame retardant of component A is a liquid flame retardant containing an ammonium phosphate structure; preferably, the liquid flame retardant is grafted with a polydimethylsiloxane structure.

[0020] In this invention, the hydrogen content of the hydrogen-containing silicone oil in component B is 1-1.6 wt%, and the viscosity is 10-100 mPa·s.

[0021] In this invention, the inhibitor of component B is one or more of vinyl cyclic compounds, 1-ethynyl-1-cyclohexanol, and 1,3-divinyltetramethyldisiloxane.

[0022] Another object of the present invention is to provide a method for preparing the above-mentioned microwave absorbing sealant.

[0023] A method for preparing the above-mentioned microwave absorbing sealant material, wherein the method comprises: mixing components A and B evenly and dispensing them into equal-volume tubing for later use.

[0024] In one embodiment, the A and B components of the adhesive are mixed and extruded into strips, coated or potted, cured and foamed at room temperature, and after 24 hours, a cured silicone microwave absorbing sealant is obtained.

[0025] Compared with the prior art, the positive effects of the present invention are as follows:

[0026] (1) The absorption capacity of the material is improved. The permeability of ordinary wave absorbing materials is below 100, while the permeability of the present invention is above 120 under the same frequency conditions (1G).

[0027] (2) The density of the material has been reduced; the density of ordinary microwave absorbing materials is 2.0 g / cm³. 3 The present invention adopts a foaming process, which greatly reduces the density to 1.0 g / cm³. 3 This helps meet the lightweight design requirements of applications;

[0028] (3) The material is designed as a two-component adhesive, which is well used online. Compared with ordinary sheets, it reduces the molding process and is conducive to on-site automation. It can also be used in small spaces. Detailed Implementation

[0029] The following embodiments further illustrate the technical solutions provided by the present invention, but the present invention is not limited to the listed embodiments, and also includes any other known modifications within the scope of the present invention.

[0030] The raw materials used in this invention are as follows:

[0031] Vinyl silicone oils: Vi321, 300 mPa·s, vinyl content 0.57 wt%, Zhejiang Runhe Organosilicon New Material Co., Ltd.; RH-Vi395, 55 mPa·s, vinyl content 1.65 wt%, Zhejiang Runhe Organosilicon New Material Co., Ltd.

[0032] Microwave absorber: Ferrite, 99.99% purity, 300 mesh particle size, Beijing Yijin New Material Technology Co., Ltd.; Nickel oxide: 99.99% purity, 300 mesh particle size, Wujiang Runtian Fine Chemicals East China Co., Ltd.

[0033] Fumed silica: H2O, specific surface area 200 g / cm³ 2 Wacker Chemie;

[0034] Hydroxyl silicone oil: 203, hydroxyl mass fraction ≥8.0%, viscosity 30 mPa·s, Jiangsu Jinli Chemical Co., Ltd.

[0035] Hydrogen-containing silicone oil: 80 mPa·s, KF99, active hydrogen content 1.6 wt%, Shin-Etsu Chemical; 20 mPa·s, active hydrogen content 1.1 wt%, Zhejiang Runhe Organosilicon New Material Co., Ltd.

[0036] Phenyl hydrogen-containing silicone resin: active hydrogen content 0.94%, Zhejiang Runhe Organosilicon New Material Co., Ltd.

[0037] Catalyst: Castells platinum catalyst, Pt content 3000ppm, Heraeus Chemicals;

[0038] Inhibitor: 1-ethynyl-1-cyclohexanol, Zhejiang Jiancheng Organosilicon Co., Ltd.;

[0039] Liquid flame retardant: Ammonium phosphate effective content 95%, Wuhan Anruike Technology Co., Ltd., treated with polydimethylsiloxane;

[0040] Alanine: 99% purity, Anhui Huaheng Biotechnology Co., Ltd.

[0041] Phenylalanine: 99% purity, Shaanxi Chenming Biotechnology Co., Ltd.

[0042] Glycine: 99% purity, Shaanxi Chenming Biotechnology Co., Ltd.

[0043] Coupling agent: Dodecyltrimethoxysilane, 95% purity, Guangzhou Jianyi Chemical Co., Ltd.

[0044] The main analytical testing equipment and manufacturers are as follows:

[0045] Rotational viscometer: Brookfield RV, Brookfield Corporation, USA, GB / T10247-2008;

[0046] Tensile testing machine: XL-250A, Guangzhou Experimental Instrument Factory, GB / T528-2009;

[0047] Permeability: LIST-MAGNETIK permeability meter, German LIST, JB / T13536-2018;

[0048] Density: Densitometer HTY-300A, Hengteya Technology Co., Ltd., GB / T6343-2009.

[0049] Preparation of microwave absorbing agent:

[0050] Preparation of microwave absorbing agent A: Take 5g of alanine, 500g of ferrite, and 1g of 95% tetrabutyl titanate aqueous solution, mix them evenly with a high-speed mixer, heat to 150℃, stir at high speed for 4h, and cool to obtain a microwave absorbing agent coated with an alanine layer. Take 10g of dodecyltrimethoxysilane and dissolve it in 50g of 80% ethanol aqueous solution, stir evenly, then atomize it and fully contact it with the microwave absorbing agent containing the alanine layer, which is stirred at high speed. Heat to 80℃, and after the solution is used up, continue stirring for 1h, heat to 110℃, continue stirring for 1h, and cool to obtain double-layer coated microwave absorbing agent A.

[0051] Preparation of microwave absorbing agent B: Take 4g of phenylalanine, 500g of ferrite microwave absorbing agent, and 1.5g of 95% tetrabutyl titanate aqueous solution, mix them evenly with a high-speed mixer, heat to 160℃, and stir at high speed for 5h to obtain a microwave absorbing agent coated with a phenylalanine layer. Take 10g of dodecyltrimethoxysilane and dissolve it in 50g of 80% ethanol aqueous solution, stir evenly, then atomize it, and fully contact it with the microwave absorbing agent containing the phenylalanine layer being stirred at high speed. Heat to 80℃, and after the solution is used up, continue stirring for 1h, heat to 110℃, continue stirring for 1h, and cool to obtain double-layer coated microwave absorbing agent B.

[0052] Preparation of microwave absorbing agent C: Take 4.5g of glycine, 500g of nickel oxide microwave absorbing agent, and 1g of 95% tetrabutyl titanate aqueous solution, mix them evenly with a high-speed mixer, heat to 130℃, and stir at high speed for 4h to obtain a microwave absorbing agent coated with a glycine layer. Take 10g of dodecyltrimethoxysilane and dissolve it in 50g of 85% ethanol aqueous solution, stir evenly, then atomize it, and fully contact it with the high-speed stirred microwave absorbing agent containing the glycine layer, and heat to 70℃. After the solution is used up, continue stirring for 1h, heat to 110℃, continue stirring for 1h, and cool to obtain double-layer coated microwave absorbing agent C.

[0053] Preparation of microwave absorbing agent D: Dissolve 10g of dodecyltrimethoxysilane in 50g of 80% ethanol aqueous solution, stir evenly, then atomize, and fully contact with ferrite stirred at high speed, and heat to 80℃. After the solution is used up, continue stirring for 1h, heat to 110℃, continue stirring for 1h, and cool to obtain microwave absorbing agent D.

[0054] Example 1

[0055] Component A: Take 400g of 50mpa.s vinyl silicone oil and 60g of fumed silica and knead them in a kneader for 2h. Heat to 180℃, keep at that temperature for 2h, and then apply a vacuum. Cool down to below 80℃, then add 1000g of microwave absorber A, continue kneading for 1h, and then apply a vacuum. Then add 120g of hydroxyl silicone oil, 20g of liquid flame retardant, and 2g of Pt catalyst in sequence, stir for 2h, apply a vacuum, and cool to room temperature.

[0056] Component B: Take 400g of 50mpa.s vinyl silicone oil and 60g of fumed silica and knead them in a kneader for 2h, heat to 180℃, keep at the temperature for 2h, and then apply vacuum. Cool down to below 80℃, then add 1000g of microwave absorber A, continue kneading for 1h, apply vacuum, and then add 80g of 20mpa.s hydrogen-containing silicone oil, 60g of phenyl hydrogen-containing silicone resin, and 0.2g of inhibitor in sequence.

[0057] Components A and B were packaged separately in 400cc two-component tubing, extruded in a 1:1 mass ratio into a mold, and cured and foamed at room temperature with a foaming ratio of 3.5 times. After 24 hours, a cured silicone microwave absorbing sealant was obtained, and test samples were cut.

[0058] Typical test parameters are: viscosity 500 mPa·s, density 0.45 g / cm³. 3 The tensile strength is 0.2 MPa, the elongation at break is 110%, the compression rebound is 5%, the water absorption rate is 1%, and the magnetic permeability is 120.

[0059] Example 2

[0060] Component A: Take 560g of 300mpa.s vinyl silicone oil and 80g of fumed silica and knead them in a kneader for 2 hours. Heat to 180℃, keep at that temperature for 2 hours, and then apply a vacuum. Cool down to below 80℃, then add 1200g of microwave absorber B, continue kneading for 1 hour, and then apply a vacuum. Then add 120g of hydroxyl silicone oil, 40g of liquid flame retardant, and 2g of Pt catalyst in sequence, stir for 2 hours, apply a vacuum, and cool to room temperature.

[0061] Component B: Take 560g of 300mpa.s vinyl silicone oil and 80g of fumed silica and knead them in a kneader for 2 hours. Heat to 180℃, keep at that temperature for 2 hours, and then apply a vacuum. Cool down to below 80℃, then add 1200g of microwave absorber B and continue kneading for 1 hour. Apply a vacuum, then add 100g of 50mpa.s hydrogen-containing silicone oil, 40g of phenyl hydrogen-containing silicone resin, and 0.12g of inhibitor in sequence.

[0062] Components A and B were packaged separately in 400cc two-component tubing, extruded in a 1:1 mass ratio into a mold, and cured and foamed at room temperature with a foaming ratio of 3.5 times. After 24 hours, a cured silicone microwave absorbing sealant was obtained, and test samples were cut.

[0063] The typical parameters of the prepared microwave-absorbing sealant foam material are: viscosity of 800 mPa·s and density of 0.50 g / cm³. 3 Tensile strength 0.15MPa, elongation at break 60%, compression rebound 7%, water absorption 3%, magnetic permeability 135.

[0064] Example 3

[0065] Component A: Take 600g of 300mpa.s vinyl silicone oil and 100g of fumed silica and knead them in a kneader for 2 hours. Heat to 180℃, keep at that temperature for 2 hours, and then apply a vacuum. Cool down to below 80℃, then add 1400g of microwave absorber C, continue kneading for 1 hour, and then apply a vacuum. Then add 120g of hydroxyl silicone oil, 40g of liquid flame retardant, and 2g of Pt catalyst in sequence, stir for 2 hours, apply a vacuum, and cool to room temperature.

[0066] Component B: Take 600g of 300mpa.s vinyl silicone oil and 100g of fumed silica and knead them in a kneader for 2 hours. Heat to 180℃, keep at that temperature for 2 hours, and then apply a vacuum. Cool down to below 80℃, then add 1400g of microwave absorber C and continue kneading for 1 hour. Apply a vacuum, then add 140g of 50mpa.s hydrogen-containing silicone oil, 20g of phenyl hydrogen-containing silicone resin, and 0.12g of inhibitor in sequence.

[0067] Components A and B were packaged separately in 400cc two-component tubing, extruded in a 1:1 mass ratio into a mold, and cured and foamed at room temperature with a foaming ratio of 3.5 times. After 24 hours, a cured silicone microwave absorbing sealant was obtained, and test samples were cut.

[0068] The typical parameters of the prepared microwave-absorbing sealant foam material are: viscosity of 1000 mPa·s and density of 0.54 g / cm³. 3 Tensile strength 0.23 MPa, elongation at break 60%, compression rebound 9%, water absorption 2.5%, magnetic permeability 150.

[0069] Comparative Example 1

[0070] Component A: Take 400g of 300mpa.s vinyl silicone oil and 60g of fumed silica and knead them in a kneader for 2 hours. Heat to 180℃, keep at that temperature for 2 hours, and then apply a vacuum. Cool down to below 80℃, then add 800g of microwave absorber D, continue kneading for 1 hour, and then apply a vacuum. Then add 120g of hydroxyl silicone oil, 20g of liquid flame retardant, and 2g of Pt catalyst in sequence, stir for 2 hours, apply a vacuum, and cool to room temperature.

[0071] Component B: Take 400g of 300mpa.s vinyl silicone oil and 60g of fumed silica and knead them in a kneader for 2 hours. Heat to 180℃, keep at that temperature for 2 hours, and then apply a vacuum. Cool down to below 80℃, then add 800g of microwave absorber D, continue kneading for 1 hour, apply a vacuum, and then add 80g of 20mpa.s hydrogen-containing silicone oil, 60g of phenyl hydrogen-containing silicone resin, and 0.2g of inhibitor in sequence.

[0072] Components A and B were packaged separately in 400cc two-component tubing, extruded in a 1:1 mass ratio into a mold, and cured and foamed at room temperature with a foaming ratio of 3.5 times. After 24 hours, a cured silicone microwave absorbing sealant was obtained, and test samples were cut.

[0073] The typical parameters of the prepared microwave-absorbing sealant foam material are: viscosity of 700 mPa·s and density of 0.51 g / cm³. 3 Tensile strength 0.15MPa, elongation at break 105%, compression rebound 4.5%, water absorption 1.1%, magnetic permeability 90.

[0074] Those skilled in the art will understand that modifications or adjustments can be made to the present invention based on the teachings of this specification. These modifications or adjustments should also be within the scope defined by the claims of the present invention.

Claims

1. A two-component silicone foamed wave-absorbing caulk material, characterized by, The gap filling material is composed of A and B two components, wherein the A component contains the following raw materials by mass fraction: The B component contains the following raw materials by mass fraction: The wave absorbing agent is a multi-layer material obtained by coating an amino acid layer on the surface of a metal oxide and coating a silane coupling agent layer outside the amino acid layer.

2. The wave-absorbing caulk material according to claim 1, characterized by, The vinyl silicone oil of the A component and the B component is a low viscosity vinyl silicone oil, and the viscosity of the vinyl silicone oil is 50-500 mpa.s.

3. The wave absorbing caulk material according to claim 1, wherein The amino acid contained in the amino acid layer of the wave absorbing agent of the A component and the B component is one or more of alanine, valine, leucine, isoleucine, proline, glycine, tryptophan, and phenylalanine. And / or, the silane coupling agent of the wave absorbing agent in the A component and the B component is a trimethoxysilane containing a long chain alkyl group.

4. The wave absorbing caulk material of claim 1, wherein The metal oxide of the A component and the B component is ferrite and / or nickel oxide.

5. The wave absorbing caulk material of claim 1, wherein The hydroxyl silicone oil of the A component is a single-end hydroxyl and / or double-end hydroxyl silicone oil.

6. The wave absorbing caulk material of claim 1, wherein The platinum catalyst of the A component is a Karstedt platinum gold catalyst.

7. The wave absorbing caulk material of claim 1, wherein The liquid flame retardant of the A component is a liquid flame retardant containing an ammonium phosphate structure.

8. The wave absorbing caulk material of claim 7, wherein The liquid flame retardant of the A component is treated with polydimethylsiloxane.

9. The wave absorbing caulk material of claim 1, wherein The hydrogen-containing silicone oil of the B component contains 1-1.6wt% of hydrogen and has a viscosity of 10-100 mpa.s.

10. The wave absorbing caulk material of claim 1, wherein The inhibitor of the B component is one or more of a vinyl ring, 1-ethynyl-1-cyclohexanol, and 1,3-divinyltetramethyldisiloxane.

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