Silicone grease conductive adhesive composition, silicone grease conductive adhesive, preparation method and application thereof

Abstract

The present application relates to the technical field of conductive adhesives, and specifically discloses a silicone conductive adhesive composition, silicone conductive adhesive, and a preparation method and application thereof. The present application discloses a silicone conductive adhesive composition, comprising the following components in parts by weight: 18-25 parts of liquid silicone rubber; 70-79 parts of conductive particles; 0.5-1.5 parts of hydroxy silicone oil; 1-3 parts of coupling agent; 3-7 parts of auxiliary agent; wherein the auxiliary agent includes one or two of glyceryl monostearate and propyl gallate and calcium carbonate. The present application also discloses a silicone conductive adhesive prepared using the above-mentioned silicone conductive adhesive composition and a preparation method thereof, the silicone conductive adhesive having excellent conductive properties and mechanical properties, simple use method, and can be cured at room temperature.

Description

Technical Field

[0001] The present application relates to the technical field of conductive adhesives, and in particular to a silicone conductive adhesive composition, a silicone conductive adhesive, and a preparation method and application thereof. Background Art

[0002] With the vigorous development of science and technology, as a hot spot in today's material research, conductive adhesive materials have excellent and stable conductivity and electromagnetic shielding effect, and have excellent water vapor sealing and mechanical properties. They have been widely used in metal shell sealing, conductive connections and electromagnetic shielding materials.

[0003] Among many types of conductive adhesives, silicone conductive adhesive uses highly viscous silicone as the matrix, and evenly distributes conductive particles in the silicone matrix. Pressure is used to make the conductive particles contact. The silicone conductive adhesive prepared by the above method has good conductive properties. Compared with other conductive adhesives, silicone conductive adhesive materials have a wider range of high and low temperature applications and a longer service life; at the same time, the strong chemical bond between the two parts of the silicone rubber matrix makes it difficult for the conductive adhesive composite material layer to peel off. Compared with ordinary extruded conductive adhesive products, silicone conductive adhesive has better processing and manufacturing performance, and is particularly suitable for manufacturing conductive adhesive products with good conductive properties, complex shapes, and fine structures.

[0004] At present, most silicone conductive adhesives are two-component. When using, the two components need to be mixed together in proportion and then used immediately, and cannot be recycled. Therefore, the use of two-component silicone conductive adhesives is relatively complicated and easily causes waste, increasing the cost of conductive adhesives. In addition, in order to meet the requirements of good conductivity, a large amount of conductive particles is used, which makes the shear strength and peel strength of silicone conductive adhesives lower, reducing the mechanical properties of conductive adhesives, thus seriously limiting the application of silicone conductive adhesives.

[0005] Therefore, it is necessary to improve the above-mentioned defects of silicone conductive adhesive to broaden its application range. Summary of the invention

[0006] In order to simplify the use of silicone conductive adhesive and obtain silicone conductive adhesive with excellent conductivity and mechanical properties, the present application provides a silicone conductive adhesive composition, silicone conductive adhesive and a preparation method and application thereof.

[0007] In a first aspect, the present application provides a silicone conductive adhesive composition, which adopts the following technical solution:

[0008] A silicone conductive adhesive composition comprises the following components in parts by weight: 18-25 parts of liquid silicone rubber; 70-79 parts of conductive particles; 0.5-1.5 parts of hydroxy silicone oil; 1-3 parts of coupling agent; and 3-7 parts of auxiliary agent; wherein the auxiliary agent comprises one or two of glyceryl monostearate and propyl gallate and calcium carbonate.

[0009] The present application utilizes one or two of glyceryl monostearate and propyl gallate and calcium carbonate as auxiliary agents, and liquid silicone rubber, conductive particles, hydroxy silicone oil and coupling agent as components in the silicone grease conductive adhesive composition, and controls the amount and ratio of the above components, so as to obtain a single-component silicone grease conductive adhesive with relatively excellent conductive properties and mechanical properties. The silicone grease conductive adhesive does not need to be blended when used, which simplifies the method of use; and the silicone grease conductive adhesive can be cured at room temperature, and has the excellent performance of a short curing time.

[0010] Preferably, the liquid silicone rubber is selected from at least one of polydimethylsiloxane, polymethylhydrogensiloxane and dihydroxypolydimethylsiloxane.

[0011] The present application chooses to use liquid silicone rubber as the matrix. Due to the fluidity of liquid silicone rubber, compared with solid silicone rubber, the conductive adhesive prepared using liquid silicone rubber has excellent processing performance and is easier to shape.

[0012] Preferably, the coupling agent is selected from at least one of methyltriethoxysilane, tetramethoxysilane, methylvinylbispyrrolidonesilane and vinyltriethoxysilane.

[0013] The coupling agent is beneficial to enhance the coating between the conductive powder and the silicone rubber in the silicone conductive adhesive system, and at the same time increase the compatibility of the components in the system, further improving the performance of the silicone conductive adhesive. In this application, the coupling agent is a conventional component in the conductive rubber and no specific requirements are made.

[0014] The conductive particles in the conductive adhesive are easy to migrate, which will lead to a decrease in the conductivity of the conductive silicone surface and unstable conductivity; and the addition of conductive particles will reduce the mechanical properties of the silicone conductive adhesive. The present application found that the use of one or two of monostearate glyceryl and propyl gallate and calcium carbonate as additives can significantly improve the above defects, so that the conductive particles can be fully dispersed in the system; at the same time, increasing the cross-linking points between other components and silicone rubber is conducive to improving the intermolecular forces between the components in the silicone conductive adhesive, thereby improving the conductivity and mechanical properties of the silicone conductive adhesive.

[0015] Preferably, the additive amount is 4.5-5.5 parts.

[0016] In a specific embodiment, the additive amount may be 3 parts, 4.5 parts, 5 parts, 5.5 parts, or 7 parts.

[0017] In some specific embodiments, the additive amount may be 3-4.5 parts, 3-5 parts, 3-5.5 parts, 4.5-5 parts, 4.5-7 parts, 5-5.5 parts, 5-7 parts, 5.5-7 parts.

[0018] After experimental analysis, it is known that when the amount of additive added is less than 3 parts, the shear strength and peel strength of the silicone conductive adhesive are poor; when the amount of additive added is more than 7 parts, the conductivity of the silicone conductive adhesive drops sharply. Therefore, in order to obtain a silicone conductive adhesive with excellent conductivity and mechanical properties, the application controls the amount of additive added within the above range.

[0019] Furthermore, the auxiliary agent comprises glyceryl monostearate, propyl gallate and calcium carbonate in a weight ratio of (0.1-0.3):(0.1-0.3):7.

[0020] In a specific embodiment, the weight ratio of glyceryl monostearate, propyl gallate and calcium carbonate can be 0.1:0.1:7, 0.1:0.2:7, 0.1:0.3:7, 0.2:0.1:7, 0.2:0.2:7, 0.2:0.3:7, 0.3:0.1:7, 0.3:0.2:7, 0.3:0.3:7.

[0021] In some specific embodiments, the weight ratio of glyceryl monostearate, propyl gallate and calcium carbonate can also be (0.1-0.2):0.1:7, (0.1-0.2):0.2:7, (0.1-0.2):0.3:7, (0.2-0.3):0.1:7, (0.2-0.3):0.2:7, (0.2-0.3):0.3:7, 0.1:(0.1-0.2):7, 0.2:(0.1-0.2):7, 0.3:(0.1-0.2):7, 0.1:(0.2-0.3):7, 0.2:(0.2-0.3):7, 0.3:(0.2-0.3):7.

[0022] Through experimental analysis, it is known that when the weight ratio of glyceryl monostearate, propyl gallate, and calcium carbonate in the auxiliary agent is controlled within the above range, the conductivity, shear strength, and peel strength of the silicone conductive adhesive can be further improved. Therefore, the present application controls the weight ratio of glyceryl monostearate, propyl gallate, and calcium carbonate within the above range.

[0023] Furthermore, the particle size of the calcium carbonate is 5-15 um.

[0024] The performance of the additive is affected by the particle size of calcium carbonate. The present application found that controlling the particle size of calcium carbonate within the above range can effectively improve the role of the additive in the silicone grease conductive adhesive, which is beneficial to further improve the conductivity and mechanical properties of the silicone grease conductive adhesive.

[0025] Preferably, the conductive particles are selected from at least one of glass silver-plated powder, graphite nickel-plated powder and copper silver-plated powder.

[0026] Through experimental analysis, it is known that when copper-plated silver powder, glass-plated silver powder, and graphite-plated nickel powder are selected as conductive particles, the performance of silicone grease conductive adhesive is in the order of copper-plated silver powder>glass-plated silver powder>graphite-plated nickel powder. This application provides the above three silicone grease conductive adhesives with different conductivity, and different conductive particles are selected according to the cost of conductive particles and the different requirements for conductivity.

[0027] Furthermore, the particle size of the conductive particles is 100-200 nm.

[0028] If the particle size of the conductive particles is too large or too small, it will significantly affect the conductive properties and mechanical properties of the silicone conductive adhesive. In the formula and preparation method provided in this application, when the particle size of the conductive particles is less than 100nm, in the material system of equal volume, the filling amount of the conductive particles is relatively large, while the proportion of silicone rubber and other components is relatively small, which significantly improves the conductivity of the silicone conductive adhesive, but reduces the elongation and bonding strength of the silicone conductive adhesive; when the particle size of the conductive particles is greater than 200nm, in the material system of equal volume, the filling amount of the conductive particles is relatively small, while the proportion of silicone rubber and other components will increase relatively, which significantly improves the elongation and bonding strength of the silicone conductive adhesive, but reduces the conductivity of the silicone conductive adhesive. Therefore, this application preferably uses conductive particles with a particle size between 100-200nm.

[0029] Preferably, the content of hydroxyl groups in the hydroxyl silicone oil is 1-3 wt %.

[0030] Silicone rubber is a linear polymer formed by the reaction of dimethylsiloxane and organic silicon monomers. The silicone rubber matrix in the conductive adhesive contains some unreacted silanol groups. The present application selects to use hydroxy silicone oil to add to the silicone conductive adhesive. The hydroxyl groups in the hydroxy silicone oil and the silanol groups in the silicone rubber produce hydrogen bonds, which is beneficial to improve the compatibility between the silicone rubber and other components, thereby improving the conductivity and mechanical properties of the silicone conductive adhesive. At the same time, the present application controls the hydroxyl content in the hydroxy silicone oil to 1-3wt%, thereby further improving the conductivity and mechanical properties of the silicone conductive adhesive.

[0031] In a second aspect, the present application provides a silicone conductive adhesive, which is prepared from the above-mentioned silicone conductive adhesive composition.

[0032] In a third aspect, the present application provides a method for preparing the above-mentioned silicone conductive adhesive, which specifically comprises the following steps:

[0033] S1: according to the formula, weigh the calcium carbonate and ultrasonically disperse it in an alcohol solvent, heat it to 40-50° C., add one or both of the glyceryl monostearate and the propyl gallate, react for 3-5 hours, and then dry it to prepare the auxiliary agent;

[0034] S2: Under vacuum conditions, the liquid silicone rubber, the conductive particles, the hydroxy silicone oil and the auxiliary agent are stirred and mixed, and then a coupling agent is added to react to obtain the silicone conductive adhesive.

[0035] Preferably, the alcohol solvent is selected from at least one of isopropanol, methanol, n-butanol and isobutanol.

[0036] The present application utilizes alcohol solution as solvent, which is conducive to the full reaction of one or both of glyceryl monostearate and propyl gallate with calcium carbonate, and then the prepared auxiliary agent is coordinated with other components to make the silicone grease conductive adhesive have good conductivity and mechanical properties.

[0037] The traditional preparation method of silicone conductive adhesive usually involves stirring the reaction in a non-vacuum state, which makes it easy for bubbles to form between the mixed components in the material system. These bubbles are retained in the system, resulting in uneven mixing of the silicone conductive adhesive and greatly weakening the bonding force between the components, thereby reducing the conductivity and mechanical properties of the silicone conductive adhesive. Therefore, the present application chooses to prepare silicone conductive adhesive under vacuum conditions to improve the above defects.

[0038] Preferably, the reaction conditions of step S2 are: vacuum degree of 0.2-0.4 MPa; stirring speed of 1500-3000 rpm; temperature of 20-30° C.; and time of 10-20 min.

[0039] The present application selects to fully mix the components under vacuum conditions, and controls the vacuum degree, stirring speed, temperature and time within the above ranges, which can effectively promote the completeness of the reaction, thereby further improving the performance of the silicone conductive adhesive.

[0040] In a fourth aspect, the present application also provides the application of the above-mentioned silicone conductive adhesive in conductive materials.

[0041] The silicone conductive adhesive prepared in the present application has good electrical conductivity and mechanical properties, and has the following many applications: (1) It can be used to connect or install various different conductive silicone rubber EMI gaskets; (2) Connect conductive rubber strips and shielding / sealing rings or gaskets with continuous travel; (3) The conductive gasket can be positioned on the shielding window fixing frame or on the groove edge of the embedded glass, and then the framed shielding window can be installed on the shielding body; (4) It is used to fix EMI shielding gaskets through components such as connectors or switches; (5) Connect small conductive screens or honeycomb or metal shielding ventilation panels to the shell; (6) Fix EMI gaskets in the grooves of cast chassis or cover plates; (7) It can be used to fill gaps.

[0042] In summary, the technical solution of this application has the following effects:

[0043] The present application uses one or two of monostearate glyceryl and propyl gallate and calcium carbonate as auxiliary agents, and liquid silicone rubber, conductive particles, hydroxy silicone oil and coupling agent as components in the silicone conductive adhesive composition, and controls the amount and ratio of the above components to prepare a silicone conductive adhesive. The silicone conductive adhesive has excellent conductivity, shear strength and peel strength; the silicone conductive adhesive can be used directly and has a simple operation method; at the same time, the silicone conductive adhesive can be cured at room temperature.

[0044] The present application further improves the conductivity and mechanical properties of silicone conductive adhesive by screening the addition amount of the additive, the weight ratio of glyceryl monostearate, propyl gallate and calcium carbonate in the additive, and the particle size of calcium carbonate.

[0045] The present application utilizes vacuum reaction conditions to effectively eliminate the generation of bubbles in the silicone grease conductive adhesive material, while promoting the mutual bonding force between silicone rubber, conductive particles and other components, thereby further improving the conductivity and mechanical properties of the silicone grease conductive adhesive. DETAILED DESCRIPTION

[0046] In the first aspect, the present application provides a silicone conductive adhesive, comprising the following components in parts by weight: 18-25 parts of liquid silicone rubber; 70-79 parts of conductive particles; 0.5-1.5 parts of hydroxy silicone oil; 1-3 parts of coupling agent; 3-7 parts of auxiliary agent; wherein the auxiliary agent includes one or two of glyceryl monostearate and propyl gallate and calcium carbonate.

[0047] The liquid silicone rubber is selected from at least one of polydimethylsiloxane, polymethylhydrogensiloxane and dihydroxypolydimethylsiloxane; the coupling agent is selected from at least one of methyltriethoxysilane, tetramethoxysilane, methylvinylbispyrrolidonesilane and vinyltriethoxysilane.

[0048] Specifically, the additive amount is 4.5-5.5 parts; the additive includes glyceryl monostearate, propyl gallate and calcium carbonate with a particle size of 5-15 um in a weight ratio of (0.1-0.3): (0.1-0.3): 7.

[0049] Meanwhile, the conductive particles are selected from at least one of glass silver-plated powder, graphite nickel-plated powder and copper silver-plated powder, and the particle size of the conductive particles is 100-200nm.

[0050] Furthermore, the content of hydroxyl groups in the hydroxy silicone oil is 1-3 wt %.

[0051] In a second aspect, the present application provides a silicone conductive adhesive prepared using the above-mentioned silicone conductive adhesive composition.

[0052] In a third aspect, the present application provides a method for preparing the above-mentioned silicone conductive adhesive, which specifically comprises the following steps:

[0053] S1: According to the formula, calcium carbonate is weighed and ultrasonically dispersed in an alcohol solvent, the temperature is raised to 40-50° C., one or two of glyceryl monostearate and propyl gallate are added, the reaction is carried out for 3-5 hours, and then the mixture is dried to prepare an auxiliary agent;

[0054] S2: Under vacuum conditions, liquid silicone rubber, conductive particles, hydroxy silicone oil and additives are stirred and mixed, and then a coupling agent is added to react to obtain silicone conductive adhesive; wherein the reaction conditions are: vacuum degree of 0.2-0.4MPa; stirring speed of 1500-3000rpm; temperature of 20-30°C; time of 10-20min.

[0055] In a fourth aspect, the present application provides the application of the above-mentioned silicone conductive adhesive in conductive materials.

[0056] Unless otherwise specified, the reagents, methods and equipment used in this application are conventional reagents, methods and equipment in this technical field.

[0057] The present application is further described in detail below in conjunction with examples, comparative examples and performance testing experiments. These examples should not be construed as limiting the scope of protection claimed in the present application.

[0058] Example

[0059] Examples 1-10

[0060] Embodiments 1-10 respectively provide a silicone conductive adhesive.

[0061] The differences among the above embodiments are: the amount of additive added and the amount of each component in the additive added, as shown in Table 1.

[0062] The implementation method of the above embodiment specifically includes the following steps:

[0063] S1: According to the formula in Table 1, calcium carbonate with a particle size of 15 um was weighed and ultrasonically dispersed in 50 mL of isopropanol. The temperature was raised to 45°C, and then glyceryl monostearate and propyl gallate were added. The reaction was kept warm for 3-6 hours. After the reaction was completed, it was dried at 90°C to obtain an auxiliary agent.

[0064] S2: Under the condition of vacuum degree of 0.3Mpa, 20g liquid silicone rubber, 76g copper-plated silver powder as conductive particles, 1g hydroxy silicone oil with a hydroxyl content of 2wt% and 5g additives were stirred and mixed at 25°C and 2000rpm, and then 2g N,N-dimethyl-3-aminopropyltrimethoxysilane was added as a coupling agent. The reaction was stirred at 25°C and 2000rpm for 15min to obtain silicone grease conductive adhesive.

[0065] Table 1 The amount of additives added in Examples 1-10 and the amount of each component in the additives added

[0066]

[0067] Examples 11-14

[0068] Embodiments 11-14 respectively provide a silicone conductive adhesive.

[0069] The difference between the above embodiments and embodiment 1 is that the particle size of calcium carbonate is shown in Table 2.

[0070] Table 2 Particle size of calcium carbonate in Examples 1, 11-14

[0071]

[0072] Embodiment 15

[0073] This embodiment provides a silicone conductive adhesive.

[0074] The difference between this embodiment and the first embodiment is that the conductive particles are glass silver-plated powder. The remaining steps are the same as the first embodiment.

[0075] Example 16

[0076] This embodiment provides a silicone conductive adhesive.

[0077] The difference between this embodiment and embodiment 1 is that the conductive particles are graphite nickel-plated powder. The remaining steps are the same as those in embodiment 1.

[0078] Embodiment 17

[0079] This comparative example provides a silicone conductive adhesive.

[0080] The difference between this comparative example and Example 1 is that the hydroxyl content of the hydroxy silicone oil is 0.5 wt %.

[0081] Embodiment 18

[0082] This comparative example provides a silicone conductive adhesive.

[0083] The difference between this comparative example and Example 1 is that the hydroxyl content of the hydroxy silicone oil is 3.5 wt %.

[0084] Comparative Example

[0085] Comparative Example 1

[0086] This comparative example provides a silicone conductive adhesive.

[0087] The difference between this comparative example and Example 1 is that:

[0088] The preparation method of the silicone conductive adhesive in this comparative example is:

[0089] According to the formula, under the condition of vacuum degree of 0.3Mpa, 20g liquid silicone rubber, 76g copper-plated silver powder as conductive particles and 1g hydroxyl silicone oil with a hydroxyl content of 2wt% were stirred and mixed at 25°C and 2000rpm, and then 2g N,N-dimethyl-3-aminopropyltrimethoxysilane was added as a coupling agent. The reaction was stirred at 25°C and 2000rpm for 15min to obtain silicone grease conductive adhesive.

[0090] Comparative Example 2

[0091] This comparative example provides a silicone conductive adhesive.

[0092] The difference between this comparative example and Example 1 is that:

[0093] The preparation method of the silicone conductive adhesive in this comparative example is:

[0094] According to the formula, under the condition of vacuum degree of 0.3Mpa, 20g liquid silicone rubber, 76g copper-plated silver powder as conductive particles, 1g hydroxy silicone oil with a hydroxyl content of 2wt% and 5g calcium carbonate with a particle size of 15um as an auxiliary agent were stirred and mixed at 25°C and 2000rpm, and then 2g N,N-dimethyl-3-aminopropyltrimethoxysilane was added as a coupling agent. The reaction was stirred at 25°C and 2000rpm for 15min to obtain silicone grease conductive adhesive.

[0095] Comparative Example 3

[0096] This comparative example provides a silicone conductive adhesive.

[0097] The difference between this comparative example and Example 1 is that the amount of the additive added is 2 g.

[0098] Comparative Example 4

[0099] This comparative example provides a silicone conductive adhesive.

[0100] The difference between this comparative example and Example 1 is that the amount of the additive added is 8 g.

[0101] Performance testing

[0102] The silicone conductive adhesives in Examples 1-18 and Comparative Examples 1-4 were used as test objects, and the volume resistivity, Shore hardness, shear strength, and peel strength of the silicone conductive adhesives were tested.

[0103] The technical requirements for silicone conductive adhesive are: volume resistivity ≤ 0.008Ω·cm; hardness = 58-72HA; shear strength ≥ 0.83Mpa; 108℃ peel strength ≥ 1.0KN / m.

[0104] (1) Volume resistivity: tested according to the standard method of ASTM D257.

[0105] (2) Shore hardness: tested in accordance with the standard method of GB / T 531.1-2008.

[0106] (3) Shear strength: tested according to the standard method of GB / T7124-2008.

[0107] (4) Peel strength: tested according to the test method of HB 5249-93.

[0108] Test results: as shown in Table 3.

[0109] Table 3 Performance test results of silicone conductive adhesive in Examples 1-18 and Comparative Examples 1-4

[0110]

[0111]

[0112] Combined with Table 3, by comparing the test results of Examples 1-18 and Comparative Examples 1-4, the present application uses one or two of glyceryl monostearate and propyl gallate and calcium carbonate as auxiliary agents, and liquid silicone rubber, conductive particles and coupling agents as components in the silicone conductive adhesive composition, and controls the amount and ratio of the above components. The volume resistivity of the prepared silicone conductive adhesive is lower than 0.008Ω·cm, the Shore hardness is in the range of 58-70HA, the shear strength is higher than 1.2MPa, and the peel strength is higher than 1.5KN / m. The above test results show that the silicone conductive adhesive prepared by the present application has good conductivity and mechanical properties; and the silicone conductive adhesive is a moisture-curing composition that can be used directly, can be cured at room temperature, and can achieve a non-sticky effect in a short time. The parts can be touched after 2 hours, and the parts can be used after 72 hours.

[0113] By comparing the test results of Examples 1, 4-5 and Comparative Examples 1-2, compared with not using an auxiliary agent, or choosing to use calcium carbonate alone as an auxiliary agent, the present application chooses to use glyceryl monostearate alone, or to use propyl gallate and calcium carbonate alone as an auxiliary agent, which can significantly improve the conductivity, shear strength and peel strength of the silicone conductive adhesive. Therefore, the present application chooses to use glyceryl monostearate, or to use propyl gallate and calcium carbonate as auxiliary agents. Further, the present application chooses to use glyceryl monostearate and propyl gallate in combination with calcium carbonate as auxiliary agents.

[0114] By comparing the test results of Examples 1-3 with Comparative Examples 3-4, when the amount of the additive added is less than 3 parts, the conductivity of the silicone conductive adhesive does not change significantly, but the Shore hardness, shear strength and peel strength are poor; when the amount of the additive added is more than 7 parts, the conductivity of the silicone conductive adhesive drops sharply. Therefore, in order to obtain a silicone conductive adhesive with good conductivity, shear strength and peel strength, the application controls the amount of additive added to be within the range of 3-7 parts.

[0115] By comparing the test results of Example 1 with those of Examples 6-10, when the weight ratio of glyceryl monostearate, propyl gallate, and calcium carbonate in the auxiliary agent is controlled within the range of (0.1-0.3): (0.1-0.3): 7, the conductivity and mechanical properties of the silicone conductive adhesive can be further improved. Therefore, the present application controls the weight ratio of glyceryl monostearate, propyl gallate, and calcium carbonate within the above range.

[0116] By comparing the test results of Example 1 with those of Examples 11-14, when the particle size of calcium carbonate is controlled within the range of 5-15 um, the conductivity and mechanical properties of the silicone conductive adhesive can be further improved. Therefore, the particle size of calcium carbonate is controlled within the above range in this application.

[0117] By comparing the test results of Example 1 with those of Examples 15-16, when copper silver-plated powder, glass silver-plated powder, and graphite nickel-plated powder are selected as conductive particles, the conductivity of the prepared silicone conductive adhesive is 0.0051Ω·cm, 0.0068Ω·cm, and 0.0080Ω·cm, respectively, while other properties are reduced. The test results show that when the conductive particles change while other components and dosages remain unchanged, the shear strength and peel strength of the silicone conductive adhesive will be affected, and the relationship of the comprehensive performance of the silicone conductive adhesive is copper silver-plated powder>glass silver-plated powder>graphite nickel-plated powder.

[0118] By comparing the test results of Example 1 with those of Examples 17-18, when the content of hydroxyl groups in the hydroxyl silicone oil is controlled within the range of 1-3wt%, the conductivity and mechanical properties of the silicone conductive adhesive can be further improved. Therefore, the present application controls the content of hydroxyl groups in the hydroxyl silicone oil within the above range.

[0119] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made thereto based on the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A silicone conductive adhesive composition, It is characterized in that The invention comprises the following components in parts by weight: 18-25 parts of liquid silicone rubber; 70-79 parts of conductive particles; 0.5-1.5 parts of hydroxy silicone oil; 1-3 parts of coupling agent; 3-7 parts of auxiliary agent; the auxiliary agent comprises glyceryl monostearate, propyl gallate and calcium carbonate in a weight ratio of (0.1-0.3): (0.1-0.3):

7.

2. The silicone conductive adhesive composition according to claim 1, It is characterized in that The additive amount is 4.5-5.5 parts.

3. The silicone conductive adhesive composition according to claim 1, It is characterized in that The particle size of the calcium carbonate is 5-15um.

4. The silicone conductive adhesive composition according to claim 1, It is characterized in that The conductive particles are selected from at least one of glass silver-plated powder, graphite nickel-plated powder and copper silver-plated powder.

5. The silicone conductive adhesive composition according to claim 4, It is characterized in that The particle size of the conductive particles is 100-200 nm.

6. The silicone conductive adhesive composition according to claim 1, It is characterized in that The content of hydroxyl groups in the hydroxy silicone oil is 1-3 wt %.

7. A silicone conductive adhesive, It is characterized in that The silicone conductive adhesive is prepared from the silicone conductive adhesive composition described in any one of claims 1 to 6.

8. The method for preparing the silicone conductive adhesive according to claim 7, It is characterized in that The specific steps include: S1: according to the formula, weigh the calcium carbonate and ultrasonically disperse it in an alcohol solvent, heat it to 40-50° C., add the glyceryl monostearate and the propyl gallate, react for 3-5 hours, and then dry it to prepare the auxiliary agent; S2: Under vacuum conditions, the liquid silicone rubber, the conductive particles, the hydroxy silicone oil and the auxiliary agent are stirred and mixed, and then a coupling agent is added to react to obtain the silicone conductive adhesive.

9. Use of the silicone conductive adhesive as claimed in claim 7 in conductive materials.

Images