Dispensing molding FIP conductive glue material and preparation method thereof

Abstract

This invention discloses a dispensing-formed FIP conductive adhesive material, belonging to the field of composite polymer materials technology. The formulation of this FIP conductive adhesive material, by weight, includes: 20-40 parts of conductive particles, 5-15 parts of crosslinking agent, 50-150 parts of vinyl silicone oil, 1-10 parts of coupling agent, 1-5 parts of catalyst, and 10-20 parts of thixotropic agent. The conductive adhesive material prepared by this invention achieves curability at room temperature, eliminating the need for additional heating equipment and avoiding damage to components caused by high-temperature curing. It is compatible with various substrates such as metals and plastics, and has significant advantages in simplifying production, improving reliability, and reducing costs.

Description

Technical Field

[0001] This invention belongs to the field of composite polymer materials technology, specifically relating to a dispensing-molded FIP conductive adhesive material and its preparation method. Background Technology

[0002] FIP conductive adhesive is an electromagnetic shielding material formed through a precision dispensing process, primarily used for electromagnetic shielding and environmental sealing of electronic devices. As electronic devices become increasingly miniaturized and operate at higher frequencies, traditional shielding materials (such as metals and conductive rubber) struggle to meet the sealing requirements of precision structures. FIP conductive adhesive, due to its high precision and customizable dispensing capabilities, has become a key material in fields such as 5G communications, base station equipment, and consumer electronics.

[0003] Chinese patent CN104342081A discloses a two-component high-temperature vulcanizing conductive adhesive and its preparation method. This conductive adhesive mainly uses two-component adhesive dispensing for molding. This method requires steps such as proportioning and stirring before molding, and curing requires separate heating equipment, making the operation relatively cumbersome. Currently, a few existing technologies use single-component adhesives, but these still require heat curing and have high requirements for drying temperature.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a dispensing-formed FIP conductive adhesive material to solve the problems of cumbersome operation and the need for heating and curing.

[0006] To achieve the above objectives, the present invention provides the following technical solution: This dispensing-molded FIP conductive adhesive material, by weight, comprises the following raw materials: 20-40 parts of conductive particles, 5-15 parts of crosslinking agent, 50-150 parts of vinyl silicone oil, 1-10 parts of coupling agent, 1-5 parts of catalyst, and 10-20 parts of thixotropic agent.

[0007] Furthermore, the vinyl silicone oil is selected from vinyl polydimethylsiloxane with a molecular weight of 0.5 to 10 w.

[0008] Preferably, the vinyl silicone oil is selected from those with a molecular weight of 1 to 5 w.

[0009] Furthermore, the coupling agent is one or more of the following silane coupling agents: A171, KH550, A151, and VTPS.

[0010] Furthermore, the catalyst is dibutyltin dilaurate.

[0011] Furthermore, the crosslinking agent is tetraethyl orthosilicate, vinyltributylone oxime silane, or polymethyltriethoxysilane.

[0012] Furthermore, the thixotropic agent is fumed silica or precipitated silica.

[0013] Preferably, the thixotropic agent is fumed silica.

[0014] Furthermore, the conductive particles are silver-plated copper particles, silver-plated aluminum particles, silver-plated glass particles, nickel-plated graphite particles, or pure silver particles.

[0015] Furthermore, the particle size of the conductive particles ranges from 10 to 120 μm.

[0016] Preferably, the particle size of the conductive particles is in the range of 20~80μm, and more preferably, the particle size of the conductive particles is in the range of 20~30μm.

[0017] The preparation method of this dispensing-molded FIP conductive adhesive material includes the following specific steps: Step 1: Weigh the vinyl silicone oil and thixotropic agent according to the formula and add them to a planetary mixer and mix thoroughly at a speed of 400-500 rpm. Step 2: Add the conductive particles, coupling agent, crosslinking agent and catalyst weighed according to the formula to the homogeneous mixture obtained in Step 1. Stir at 400~500 rpm and mix thoroughly for 20~30 min to finally obtain the target FIP ​​conductive adhesive material.

[0018] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects: 1. This invention, through single-component design, pre-compiles the formula, which not only eliminates the step of controlling the mixing ratio and reduces the error in dispensing, but also avoids the curing failure problem caused by inaccurate ratio or uneven stirring when using two-component adhesives, thereby reducing the risk of operational errors.

[0019] 2. This invention uses crosslinking agents such as tetraethyl orthosilicate, vinyltributyl ketone oxime silane, or polymethyltriethoxysilane to make the entire curing process a condensation reaction, so that the prepared conductive adhesive material can be cured at room temperature without the need for additional heating equipment, thus avoiding damage to components caused by high-temperature curing. Therefore, it is compatible with a variety of substrates such as metals and plastics.

[0020] 3. By adopting a single-component adhesive design, the prepared adhesive material can be used in multiple applications, avoiding the problem of unused portions curing and being scrapped after mixing two-component adhesives. The present invention has significant advantages in simplifying production, improving reliability, and reducing costs. Detailed Implementation

[0021] Exemplary embodiments will now be described in detail. The embodiments described below are not representative of all embodiments consistent with this invention. Rather, they are merely examples consistent with some aspects of the invention as detailed in the appended claims.

[0022] Example 1 This embodiment provides a dispensing-molded FIP conductive adhesive material, specifically comprising 50 parts vinyl silicone oil, 5 parts crosslinking agent, 20 parts conductive particles, 1 part catalyst, 10 parts thixotropic agent, and 1 part coupling agent.

[0023] Specifically, the vinyl silicone oil is vinyl polydimethylsiloxane produced by Shandong Dayi Chemical Co., Ltd., with a molecular weight of 1~5 w.

[0024] Specifically, the conductive particles are nickel-plated graphite particles with a particle size of 20~30μm.

[0025] Specifically, the crosslinking agent is tetraethyl orthosilicate produced by Sinopharm Group.

[0026] Specifically, the coupling agent is A171 from Jiangxi Chenguang New Materials Co., Ltd.

[0027] Specifically, the thixotropic agent is commercially available fumed silica.

[0028] Specifically, the catalyst is dibutyltin dilaurate from Shandong Huachen New Materials Co., Ltd.

[0029] The preparation method of the FIP conductive adhesive material for dispensing in this embodiment includes the following specific steps: Step 1: Take 50 parts of vinyl silicone oil and 10 parts of thixotropic agent and add them to a planetary mixer and mix thoroughly at a speed of 400-500 rpm. Step 2: Add 20 parts of conductive particles, 1 part of coupling agent, 5 parts of crosslinking agent and 1 part of catalyst to the homogeneous mixture obtained in Step 1. Stir at 400~500 rpm and mix thoroughly for 20~30 min to finally obtain the target FIP ​​conductive adhesive material.

[0030] Specifically, the obtained target FIP ​​conductive adhesive material was applied and tested according to the following steps: First, clean the substrate surface with anhydrous ethanol, and then wipe the cleaned substrate surface with a lint-free cloth to ensure that the substrate surface is flat and free of defects.

[0031] Then, the conductive adhesive is evenly applied to the substrate surface using a fully automatic dispensing machine. The dispensing time is 60 seconds, the dispensing pressure is 4 Bar, the dispensing height is 2 mm, and the dispensing speed is 50 mm / s.

[0032] Finally, after dispensing, the adhesive was cured at room temperature for 48 hours.

[0033] The prepared conductive material was tested according to the testing standard MIL-G-83528. The shielding effectiveness of the conductive material in the P-Ka band was measured to be 90~100dB, and the volume resistivity was 3×10⁻⁶. -3 Ω·cm.

[0034] According to the testing standard GB / T528, the tensile strength of the conductive rubber material was measured to be 7.62 MPa, and the elongation at break was 430%.

[0035] According to the testing standard GB / T 533, the density of this conductive rubber material was measured to be 1.24 g / cm³. 3 .

[0036] Example 2 This embodiment provides a dispensing-molded FIP conductive adhesive material, specifically comprising 100 parts vinyl silicone oil, 10 parts crosslinking agent, 30 parts conductive particles, 3 parts catalyst, 15 parts thixotropic agent, and 5 parts coupling agent.

[0037] Specifically, the vinyl silicone oil is vinyl polydimethylsiloxane produced by Shandong Dayi Chemical Co., Ltd., with a molecular weight of 1~5 w.

[0038] Specifically, the conductive particles are silver-plated copper particles, silver-plated aluminum particles, or silver-plated glass particles, and the particle size of the conductive particles is 20~30μm. As a preferred embodiment of this example, the conductive particles are silver-plated aluminum particles.

[0039] Specifically, the crosslinking agent is vinyltributylone oxime silane manufactured by McLean.

[0040] Specifically, the coupling agents are KH550 and VTPS from Jiangxi Chenguang New Materials Co., Ltd.

[0041] Specifically, the thixotropic agent is commercially available fumed silica.

[0042] Specifically, the catalyst is dibutyltin dilaurate from Shandong Huachen New Materials Co., Ltd.

[0043] The preparation method of the FIP conductive adhesive material for dispensing in this embodiment includes the following specific steps: Step 1: Take 100 parts of vinyl silicone oil and 15 parts of thixotropic agent and add them to a planetary mixer and mix thoroughly at a speed of 400-500 rpm. Step 2: Add 30 parts of conductive particles, 5 parts of coupling agent, 10 parts of crosslinking agent and 3 parts of catalyst to the homogeneous mixture obtained in Step 1. Stir at 400~500 rpm and mix thoroughly for 20~30 minutes to finally obtain the target FIP ​​conductive adhesive material.

[0044] Specifically, the obtained target FIP ​​conductive adhesive material was applied and tested according to the following steps: First, clean the substrate surface with anhydrous ethanol, and then wipe the cleaned substrate surface with a lint-free cloth to ensure that the substrate surface is flat and free of defects.

[0045] Then, the conductive adhesive is evenly applied to the substrate surface using a fully automatic dispensing machine. The dispensing time is 60 seconds, the dispensing pressure is 4 Bar, the dispensing height is 2 mm, and the dispensing speed is 50 mm / s.

[0046] Finally, after dispensing, the adhesive was cured at room temperature for 48 hours.

[0047] The prepared conductive material was tested according to the testing standard MIL-G-83528. The shielding effectiveness of the conductive material in the P-Ka band was measured to be 90~120dB, and the volume resistivity was 5×10⁻⁶. -4 Ω·cm.

[0048] According to the testing standard GB / T528, the tensile strength of the conductive rubber material was measured to be 7.73 MPa, and the elongation at break was 360%.

[0049] According to the testing standard GB / T 533, the density of this conductive rubber material was measured to be 1.34 g / cm³. 3 .

[0050] Example 3 This embodiment provides a dispensing-molded FIP conductive adhesive material, specifically comprising 150 parts of vinyl silicone oil, 15 parts of crosslinking agent, 40 parts of conductive particles, 5 parts of catalyst, 20 parts of thixotropic agent, and 10 parts of coupling agent.

[0051] Specifically, the vinyl silicone oil is vinyl polydimethylsiloxane produced by Shandong Dayi Chemical Co., Ltd., with a molecular weight of 1~5 w.

[0052] Specifically, the conductive particles are pure silver conductive particles with a particle size of 20~30μm.

[0053] Specifically, the crosslinking agent is polymethyltriethoxysilane produced by McLean.

[0054] Specifically, the coupling agents are A151 and KH550 from Anhui Boiling Point New Materials Co., Ltd.

[0055] Specifically, the thixotropic agent is commercially available fumed silica.

[0056] Specifically, the catalyst is dibutyltin dilaurate from Shandong Huachen New Materials Co., Ltd.

[0057] The preparation method of the FIP conductive adhesive material for dispensing in this embodiment includes the following specific steps: Step 1: Take 150 parts of vinyl silicone oil and 20 parts of thixotropic agent and add them to a planetary mixer and mix thoroughly at a speed of 400-500 rpm. Step 2: Add 40 parts of conductive particles, 10 parts of coupling agent, 15 parts of crosslinking agent and 5 parts of catalyst to the homogeneous mixture obtained in Step 1. Stir at 400~500 rpm and mix thoroughly for 20~30 min to finally obtain the target FIP ​​conductive adhesive material.

[0058] Specifically, the obtained target FIP ​​conductive adhesive material was applied and tested according to the following steps: First, clean the substrate surface with anhydrous ethanol, and then wipe the cleaned substrate surface with a lint-free cloth to ensure that the substrate surface is flat and free of defects.

[0059] Then, the conductive adhesive is evenly applied to the substrate surface using a fully automatic dispensing machine. The dispensing time is 60 seconds, the dispensing pressure is 4 Bar, the dispensing height is 2 mm, and the dispensing speed is 50 mm / s.

[0060] Finally, after dispensing, the adhesive was cured at room temperature for 48 hours.

[0061] The prepared conductive material was tested according to the testing standard MIL-G-83528. The shielding effectiveness of the conductive material in the P-Ka band was measured to be 90~110 dB, and the volume resistivity was 4×10⁻⁶. -6 Ω·cm.

[0062] According to the testing standard GB / T528, the tensile strength of the conductive rubber material was measured to be 2.61 MPa, and the elongation at break was 230%.

[0063] According to the testing standard GB / T 533, the density of the conductive rubber material was measured to be 1.53 g / cm³. 3 .

[0064] Comparative Example 1 Based on Example 3, this comparative example provides a method for preparing a dispensing-molded FIP conductive adhesive material, the difference being that 200 parts of vinyl silicone oil are used.

[0065] The obtained target FIP ​​conductive adhesive material was applied by dotting according to the steps described in Example 3. Finally, after dispensing, it was cured at room temperature. After 48 hours, it still had not cured completely, and there was no sign of curing even after extending the curing time.

[0066] In this comparative example, only the amount of vinyl silicone oil was increased, without adjusting the proportion of crosslinking agent accordingly, resulting in a relative deficiency of crosslinking agent. Due to the insufficient amount of crosslinking agent, most silanol groups could not find reactive nodes, causing the chain growth reaction to stop in its initial stage. The molecular chains could only extend from short chains to medium-long chains, failing to crosslink and form a complete network structure. The resulting adhesive material remained in a fluid or semi-fluid state and could not be cured into an elastomer.

[0067] Comparative Example 2 Based on Example 2, this comparative example provides a method for preparing a dispensing-molded FIP conductive adhesive material, the difference being that 10 parts of conductive particles are used.

[0068] The obtained target FIP ​​conductive adhesive material was applied and tested according to the steps described in Example 2.

[0069] According to the testing standard GB / T528, the tensile strength of the conductive rubber material was measured to be 9.73 MPa, and the elongation at break was 760%.

[0070] According to the testing standard GB / T 533, the density of this conductive rubber material was measured to be 1.14 g / cm³. 3 .

[0071] Although the performance test results described above meet the requirements for daily use, according to the testing standard MIL-G-83528, the shielding effectiveness of this conductive material in the P-Ka band is measured to be 10-20 dB, and its volume resistivity is 3 × 10⁻⁶. 3 Its volume resistivity is too high (Ω·cm) to meet the needs of daily use.

[0072] In summary, the FIP conductive adhesive material provided by this invention, compared to conventional two-component adhesives, not only eliminates the step of controlling the mixing ratio, reducing mixing errors, but also avoids curing failures caused by inaccurate ratios or uneven mixing. Furthermore, it can cure at room temperature without the need for additional heating equipment, avoiding damage to components caused by high-temperature curing. This FIP conductive adhesive material exhibits good volume resistivity (4×10⁻⁶) at room temperature. -6 ~3×10 -3 The shielding effectiveness (Ω·cm) and tensile strength (2.61MPa~7.73MPa) in the P-Ka band are measured.

[0073] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention.

[0074] It should be understood that the present invention is not limited to the content already described above, and various modifications and changes can be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A dispensing-molded FIP conductive adhesive material, characterized in that, The FIP conductive adhesive material, by weight, comprises the following raw materials: 20-40 parts of conductive particles, 5-15 parts of crosslinking agent, 50-150 parts of vinyl silicone oil, 1-10 parts of coupling agent, 1-5 parts of catalyst, and 10-20 parts of thixotropic agent.

2. The FIP conductive adhesive material for dispensing according to claim 1, characterized in that, The vinyl silicone oil is selected from vinyl polydimethylsiloxane with a molecular weight of 0.5 to 10 w.

3. The FIP conductive adhesive material for dispensing according to claim 1, characterized in that, The coupling agent is one or more of the following silane coupling agents: A171, KH550, A151, and VTPS.

4. The FIP conductive adhesive material for dispensing according to claim 1, characterized in that, The catalyst is dibutyltin dilaurate.

5. The FIP conductive adhesive material for dispensing according to claim 1, characterized in that, The crosslinking agent is tetraethyl orthosilicate, vinyltributylone oxime silane, or polymethyltriethoxysilane.

6. The FIP conductive adhesive material for dispensing according to claim 1, characterized in that, The thixotropic agent is fumed silica or precipitated silica.

7. The FIP conductive adhesive material for dispensing according to claim 1, characterized in that, The conductive particles are silver-plated copper particles, silver-plated aluminum particles, silver-plated glass particles, nickel-plated graphite particles, or pure silver particles.

8. The FIP conductive adhesive material for dispensing according to claim 7, characterized in that, The particle size range of the conductive particles is 10-120 μm.

9. A method for preparing a dispensing-molded FIP conductive adhesive material according to any one of claims 1 to 8, characterized in that, Includes the following steps: Step 1: Weigh the vinyl silicone oil and thixotropic agent according to the formula and add them to the mixer and mix thoroughly at a speed of 400-500 rpm. Step 2: Add the conductive particles, coupling agent, crosslinking agent and catalyst weighed according to the formula to the homogeneous mixture obtained in Step 1. Stir at 400~500 rpm and mix thoroughly for 20~30 min to finally obtain the target FIP ​​conductive adhesive material.