High thermal conductivity potting adhesive and preparation method thereof

Abstract

The application discloses a high-thermal-conductivity pouring sealant and a preparation method thereof. The A component comprises the following raw material components in weight: 30-50 parts of first vinyl MQ silicone resin, 20-25 parts of alpha, omega-end hydroxyl liquid silicone rubber, 20-25 parts of vinyl polysiloxane, 60-100 parts of thermal conductive filler, 20-30 parts of inorganic flame retardant, 1-5 parts of anti-settling agent and 0.2-0.5 parts of platinum gold catalyst; the B component comprises the following components in weight: 20-25 parts of second vinyl MQ silicone resin, 10-15 parts of alpha, omega-end hydroxyl liquid silicone rubber, 10-15 parts of hydrogen-containing silicone oil, 30-40 parts of thermal conductive filler, 30-40 parts of inorganic flame retardant and 1-5 parts of anti-settling agent. The pouring sealant has appropriate tear strength and is not too large.

Description

Technical Field

[0001] This invention belongs to the field of potting compound technology, and relates to a potting compound, specifically a potting compound with high thermal conductivity and its preparation method. Background Technology

[0002] Potting compounds are used for bonding, sealing, potting, and coating protection of electronic components. Before curing, potting compounds are liquid and fluid; their viscosity varies depending on the material, performance, and manufacturing process of the product. They only become usable after complete curing, providing functions such as waterproofing, moisture resistance, dustproofing, insulation, thermal conductivity, sealing, corrosion resistance, temperature resistance, and shock absorption. There are many types of electronic potting compounds. Classified by material type, the three most common are epoxy resin potting compounds, silicone resin potting compounds, and polyurethane potting compounds.

[0003] Organosilicon thermally conductive potting compounds require good thermal conductivity, as well as certain shock resistance and excellent tensile strength to adapt to changes in environmental stress and achieve durability. Chinese invention patent application number 202111139165.3 discloses an organosilicon potting compound and its preparation method, belonging to the field of potting materials technology. This organosilicon foam potting compound has a thermal conductivity of only 0.10–0.13 W / mk, which can easily lead to heat accumulation and damage to electronic components when used for potting electronic products. Chinese invention patent application number CN202310650423.7 discloses an organosilicon thermally conductive potting compound with high rigidity, poor bonding stability, high filler cost, and complex processing, which is not conducive to large-scale industrial production and promotion. Another example is Chinese invention patent application number CN202211265934.9, which discloses an organosilicon thermally conductive potting compound with excellent shock resistance but low thermal conductivity, and the use of organotin catalysts poses a significant environmental hazard. Summary of the Invention

[0004] In order to solve the above-mentioned technical problems, the purpose of this invention is to provide a potting compound with high thermal conductivity.

[0005] To achieve the above objectives, the present invention provides a potting compound with high thermal conductivity, comprising component A and component B in a mass ratio of 1:1 to 2.

[0006] Component A comprises the following raw material components by weight: 30-50 parts of first vinyl MQ silicone resin, 20-25 parts of hydroxyl-encapsulated vinyl silicone oil, 20-25 parts of vinyl polysiloxane, 60-100 parts of thermally conductive filler, 20-30 parts of inorganic flame retardant, 0.5-1.0 parts of dispersant, 1-5 parts of anti-settling agent, and 0.2-0.5 parts of platinum catalyst, wherein the vinyl content of the first vinyl MQ silicone resin is 0.5-1.5% by weight;

[0007] Component B comprises the following components in parts by weight: 20-25 parts of second vinyl MQ silicone resin, 10-15 parts of hydroxyl-terminated vinyl silicone oil, 10-15 parts of hydrogen-containing silicone oil, 30-40 parts of thermally conductive filler, 0.5-1.0 parts of dispersant, 30-40 parts of inorganic flame retardant, and 1-5 parts of anti-settling agent, wherein the vinyl content of the second vinyl MQ silicone resin is 2.0-3.0% by weight.

[0008] Optimally, the first vinyl MQ silicone resin is a mixture of one or more components selected from SH-5202, vmq308, DT-2750 and SH-VMQ.

[0009] Optimally, the hydroxyl-terminated vinyl silicone oil has a viscosity of 2000-3000 cps at 25°C, a vinyl content of 1.0-2.0%, and a hydroxyl value of 0.5-2.0. The presence of hydroxyl groups enables the colloid to form hydrogen bonds with the surface of the inorganic filler, which is more conducive to the mixing stability of the colloid and the powder. The vinyl polysiloxane has a viscosity of 1000-2000 cps at 25°C.

[0010] Ideally, the thermally conductive filler is selected from one or more of alumina, magnesium oxide, zinc oxide, aluminum nitride, boron nitride, and silicon carbide.

[0011] Ideally, the inorganic flame retardant is one or a combination of several selected from aluminum hydroxide, magnesium hydroxide, antimony-based flame retardants, and boron-based flame retardants.

[0012] Ideally, the anti-settling agent is surface-modified fumed silica with a particle size of 20-50 nm.

[0013] Preferably, the dispersant is a methyl long-chain alkyl silicone oil, wherein the long-chain alkyl group is a C12 to C18 alkyl group.

[0014] Another object of the present invention is to provide a method for preparing the above-mentioned high thermal conductivity potting compound, comprising the following steps:

[0015] (a) Mix the first vinyl MQ silicone resin, hydroxyl-terminated vinyl silicone oil, thermally conductive filler, inorganic flame retardant, dispersant and anti-settling agent in the formulation amount, and then add the vinyl polysiloxane and platinum catalyst in the formulation amount and mix to obtain component A;

[0016] (b) Mix the formulation amounts of second vinyl MQ silicone resin, hydroxyl-terminated vinyl silicone oil, hydrogen-containing silicone oil, dispersant, thermally conductive filler, inorganic flame retardant and anti-settling agent to obtain component B;

[0017] (c) Mix the components A and B and heat to cure at 120°C for 1 hour.

[0018] The high thermal conductivity potting compound of the present invention uses a mixture of components A and B with specific components and contents to crosslink and polymerize MQ silicone resin with different vinyl contents with other components, which enables the potting compound to have suitable tear strength without being too high, and ensures excellent elongation and thermal conductivity. Detailed Implementation

[0019] This invention relates to a high thermal conductivity potting compound comprising component A and component B in a mass ratio of 1:1 to 2. Component A comprises the following raw material components by weight: 30-50 parts of a first vinyl MQ silicone resin, 20-25 parts of hydroxyl-terminated vinyl silicone oil, 20-25 parts of vinyl polysiloxane, 60-100 parts of thermally conductive filler, 20-30 parts of inorganic flame retardant, 0.5-1.0 parts of dispersant, 1-5 parts of anti-settling agent, and 0.2-0.5 parts of platinum catalyst. The vinyl content of the first vinyl MQ silicone resin is 0.5-1%. 0.5%; Component B comprises the following components in parts by weight: 20-25 parts of second vinyl MQ silicone resin, 10-15 parts of hydroxyl-terminated vinyl silicone oil, 10-15 parts of hydrogen-containing silicone oil, 0.5-1.0 parts of dispersant, 30-40 parts of thermally conductive filler, 30-40 parts of inorganic flame retardant, and 1-5 parts of anti-settling agent. The vinyl content of the second vinyl MQ silicone resin is 2.0-3.0% by weight (the second vinyl MQ silicone resin is usually prepared according to the method disclosed in CN105585714A or is commercially available). By mixing components A and B with specific components and contents, MQ silicone resins with different vinyl contents can be crosslinked and polymerized with other components, enabling the potting compound to have suitable tear strength without being too high, and ensuring excellent elongation and thermal conductivity.

[0020] The first vinyl MQ silicone resin is preferably a mixture selected from one or more of SH-5202, VMQ308, DT-2750, and SH-VMQ. The hydroxyl-terminated vinyl silicone oil preferably has a viscosity of 2000-3000 cps at 25°C, a vinyl content of 1.0-2.0%, and a hydroxyl value of 0.5-2.0; the vinyl polysiloxane preferably has a viscosity of 1000-2000 cps at 25°C. The thermally conductive filler is preferably a combination of one or more of alumina, magnesium oxide, zinc oxide, aluminum nitride, boron nitride, and silicon carbide. The inorganic flame retardant is preferably a combination of one or more of aluminum hydroxide, magnesium hydroxide, antimony-based flame retardants, and boron-based flame retardants. The anti-settling agent is preferably surface-modified fumed silica with a particle size of 20-50 nm, and the dispersant is preferably C12-C18 methyl long-chain alkyl silicone oil.

[0021] The preparation method of the above-mentioned high thermal conductivity potting compound includes the following steps: (a) mixing the first vinyl MQ silicone resin, hydroxyl-terminated vinyl silicone oil, dispersant, thermally conductive filler, inorganic flame retardant and anti-settling agent in the prescribed amounts, and then adding the vinyl polysiloxane and platinum catalyst in the prescribed amounts to obtain component A; (b) mixing the second vinyl MQ silicone resin, hydroxyl-terminated vinyl silicone oil, dispersant, hydrogen-containing silicone oil, thermally conductive filler, inorganic flame retardant and anti-settling agent in the prescribed amounts to obtain component B; (c) mixing component A and component B, and curing at 120°C for 1 hour.

[0022] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art under the premise of equivalent changes and modifications should fall within the protection scope of the present invention.

[0023] Example 1

[0024] This embodiment provides a high thermal conductivity potting compound and its preparation method. The potting compound comprises component A and component B in a mass ratio of 1:1, as detailed below:

[0025] Component A includes: 300g of first vinyl MQ silicone resin (SH-5202, vinyl content of 0.5-1.5%), 250g of hydroxyl-terminated vinyl silicone oil (viscosity of 2000-3000cps at 25°C, within which range is acceptable), 250 parts of vinyl polysiloxane (viscosity of 1000-2000cps at 25°C, within which range is acceptable), 600g of thermally conductive filler (nano-alumina MG-Al032), 200g of inorganic flame retardant (aluminum hydroxide CAS: 21645-51-2), 10g of dispersant, 10g of anti-settling agent (DM-20S), and 2g of platinum catalyst (PL-2);

[0026] Component B comprises: 200g of second vinyl MQ silicone resin (see Example 2 of CN105585714A, with a vinyl content of 2.5%), 150g of hydroxyl-terminated vinyl silicone oil (viscosity of 2000-3000cps at 25°C, within which range is acceptable), 100g of hydrogen-containing silicone oil (CR-F22H), 10g of dispersant, 400g of thermally conductive filler (nano-alumina MG-Al032), 400g of inorganic flame retardant (aluminum hydroxide CAS: 21645-51-2), and 10g of anti-settling agent (DM-20S).

[0027] The preparation method of the above-mentioned high thermal conductivity potting compound includes the following steps:

[0028] (a) Mix the first vinyl MQ silicone resin, hydroxyl-terminated vinyl silicone oil, dispersant, thermally conductive filler, inorganic flame retardant and anti-settling agent in the formulation amount, and then add the vinyl polysiloxane and platinum catalyst in the formulation amount and mix to obtain component A;

[0029] (b) The formulation amounts of second vinyl MQ silicone resin, hydroxyl-terminated vinyl silicone oil, dispersant, hydrogen-containing silicone oil, thermally conductive filler, inorganic flame retardant and anti-settling agent are mixed to obtain component B;

[0030] (c) Mix components A and B and cure at 120°C for 1 hour.

[0031] Example 2

[0032] This embodiment provides a potting compound with high thermal conductivity and its preparation method, which is basically the same as that in Example 1, except that:

[0033] Component A includes: 500g of first vinyl MQ silicone resin (SH-5202, vinyl content of 0.5-1.5%), 200g of hydroxyl-terminated vinyl silicone oil (viscosity of 2000-3000cps at 25°C, within which range is acceptable), 200 parts of vinyl polysiloxane (viscosity of 1000-2000cps at 25°C, within which range is acceptable), 10g of dispersant, 1000g of thermally conductive filler (nano-alumina MG-Al032), 300g of inorganic flame retardant (aluminum hydroxide CAS: 21645-51-2), 50g of anti-settling agent (DM-20S), and 5g of platinum catalyst (PL-2);

[0034] Component B comprises: 250g of second vinyl MQ silicone resin (see Example 2 of CN105585714A, with a vinyl content of 2.5%), 100g of hydroxyl-terminated vinyl silicone oil (viscosity of 2000-3000 cps at 25°C, within which range is acceptable), 150g of hydrogen-containing silicone oil (CR-F22H), 10g of dispersant, 300g of thermally conductive filler (nano-alumina MG-Al032), 300g of inorganic flame retardant (aluminum hydroxide CAS: 21645-51-2), and 50g of anti-settling agent (DM-20S).

[0035] Example 3

[0036] This embodiment provides a potting compound with high thermal conductivity and its preparation method, which is basically the same as that in Example 1, except that:

[0037] Component A includes: 400g of first vinyl MQ silicone resin (SH-5202, vinyl content of 0.5-1.5%), 220g of hydroxyl-terminated vinyl silicone oil (viscosity of 2000-3000cps at 25°C, within which range is acceptable), 220 parts of vinyl polysiloxane (viscosity of 1000-2000cps at 25°C, within which range is acceptable), 10g of dispersant, 800g of thermally conductive filler (nano-alumina MG-Al032), 250g of inorganic flame retardant (aluminum hydroxide CAS: 21645-51-2), 30g of anti-settling agent (DM-20S), and 3g of platinum catalyst (PL-2);

[0038] Component B comprises: 220g of second vinyl MQ silicone resin (see Example 2 of CN105585714A, with a vinyl content of 2.5%), 120g of hydroxyl-terminated vinyl silicone oil (viscosity of 2000-3000 cps at 25°C, within which range is acceptable), 120g of hydrogen-containing silicone oil (CR-F22H), 10g of dispersant, 350g of thermally conductive filler (nano-alumina MG-Al032), 350g of inorganic flame retardant (aluminum hydroxide CAS: 21645-51-2), and 35g of anti-settling agent (DM-20S).

[0039] Example 4

[0040] This embodiment provides a high thermal conductivity potting compound and its preparation method, which is basically the same as that in Example 1, except that the potting compound includes component A and component B in a mass ratio of 1:2.

[0041] Comparative Example 1

[0042] This example provides a high thermal conductivity potting compound and its preparation method, which is basically the same as that in Example 1. The difference is that component A includes: 600g of first vinyl MQ silicone resin (SH-5202, vinyl content is 0.5-1.5%), 150g of hydroxyl-terminated vinyl silicone oil (viscosity at 25°C is 2000-3000cps, within which range is acceptable), 200 parts of vinyl polysiloxane (viscosity at 25°C is 1000-2000cps, within which range is acceptable), 10g of dispersant, 1000g of thermally conductive filler (nano-alumina MG-AlO32), 300g of inorganic flame retardant (aluminum hydroxide CAS: 21645-51-2), 50g of anti-settling agent (DM-20S), and 5g of platinum catalyst (PL-2).

[0043] Comparative Example 2

[0044] This example provides a high thermal conductivity potting compound and its preparation method, which is basically the same as that in Example 1. The difference is that component A includes: 200g of first vinyl MQ silicone resin (SH-5202, vinyl content is 0.5-1.5% by mass), 300g of hydroxyl-terminated vinyl silicone oil (viscosity at 25°C is 2000-3000cps, within which range is acceptable), 200 parts of vinyl polysiloxane (viscosity at 25°C is 1000-2000cps, within which range is acceptable), 10g of dispersant, 1000g of thermally conductive filler (nano-alumina MG-AlO32), 300g of inorganic flame retardant (aluminum hydroxide CAS: 21645-51-2), 50g of anti-settling agent (DM-20S), and 5g of platinum catalyst (PL-2).

[0045] Comparative Example 3

[0046] This example provides a high thermal conductivity potting compound and its preparation method, which is basically the same as that in Example 1. The difference is that component B includes: 300g of second vinyl MQ silicone resin (see Example 2 of CN105585714A, the vinyl content is 2.5%), 80g of hydroxyl-terminated vinyl silicone oil (viscosity of 2000-3000cps at 25°C, within which range is acceptable), 80g of hydrogen-containing silicone oil (CR-F22H), 10g of dispersant, 400g of thermally conductive filler (nano-alumina MG-AlO32), 400g of inorganic flame retardant (aluminum hydroxide CAS: 21645-51-2), and 10g of anti-settling agent (DM-20S).

[0047] Comparative Example 4

[0048] This example provides a high thermal conductivity potting compound and its preparation method, which is basically the same as that in Example 1. The difference is that component B includes: 150g of second vinyl MQ silicone resin (see Example 2 of CN105585714A, the vinyl content is 2.5%), 200g of hydroxyl-terminated vinyl silicone oil (viscosity of 2000-3000cps at 25°C, within which range is acceptable), 180g of hydrogen-containing silicone oil (CR-F22H), 10g of dispersant, 400g of thermally conductive filler (nano-alumina MG-Al032), 400g of inorganic flame retardant (aluminum hydroxide CAS: 21645-51-2), and 10g of anti-settling agent (DM-20S).

[0049] Comparative Example 5

[0050] This example provides a potting compound with high thermal conductivity and its preparation method, which is basically the same as that in Example 1, except that the first vinyl MQ silicone resin is used in both component A and component B.

[0051] Comparative Example 6

[0052] This example provides a potting compound with high thermal conductivity and its preparation method, which is basically the same as that in Example 1, except that the second vinyl MQ silicone resin is used in both component A and component B.

[0053] The products of Examples 1-4 and Comparative Examples 1-6 were subjected to performance tests, and the results are shown in Table 1 (wherein, the test standard for elongation is GBT30776-2014, the test standard for thermal conductivity is ASTM-D5470, and the test standard for tensile strength is GB / T528).

[0054] Table 1 Performance of products in Examples 1-4 and Comparative Examples 1-6

[0055]

[0056] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. At the same time, those skilled in the art should understand and implement the above description. Therefore, any equivalent changes or modifications made without departing from the concept disclosed in the present invention should be covered within the scope of protection of the present invention.

Claims

1. A potting compound with high thermal conductivity, comprising component A and component B in a mass ratio of 1:1~2, characterized in that: Component A comprises the following raw material components by weight: 30-50 parts of first vinyl MQ silicone resin, 20-25 parts of hydroxyl-terminated vinyl silicone oil, 20-25 parts of vinyl polysiloxane, 60-100 parts of thermally conductive filler, 20-30 parts of inorganic flame retardant, 0.5-1.0 parts of dispersant, 1-5 parts of anti-settling agent, and 0.2-0.5 parts of platinum catalyst, wherein the vinyl content of the first vinyl MQ silicone resin is 0.5-1.5% by weight. Component B comprises the following components in parts by weight: 20-25 parts of second vinyl MQ silicone resin, 10-15 parts of hydroxyl-terminated vinyl silicone oil, 10-15 parts of hydrogen-containing silicone oil, 30-40 parts of thermally conductive filler, 30-40 parts of inorganic flame retardant, 0.5-1.0 parts of dispersant, and 1-5 parts of anti-settling agent, wherein the vinyl content of the second vinyl MQ silicone resin is 2.0-3.0% by weight. The first vinyl MQ silicone resin is a mixture of one or more components selected from SH-5202, vmq308, DT-2750 and SH-VMQ; The hydroxyl-terminated vinyl silicone oil has a viscosity of 2000-3000 cps at 25°C, and the vinyl polysiloxane has a viscosity of 1000-2000 cps at 25°C. The thermally conductive filler is selected from one or more of alumina, magnesium oxide, zinc oxide, aluminum nitride, boron nitride, and silicon carbide.

2. The high thermal conductivity potting compound according to claim 1, characterized in that: The inorganic flame retardant is selected from one or a combination of several of aluminum hydroxide, magnesium hydroxide, antimony-based flame retardants, and boron-based flame retardants.

3. The high thermal conductivity potting compound according to claim 1, characterized in that: The anti-settling agent is surface-modified fumed silica with a particle size of 20-50 nm.

4. The high thermal conductivity potting compound according to claim 1, characterized in that: The dispersant is a methyl long-chain alkyl silicone oil, wherein the long-chain alkyl group is one of C12 to C18 alkyl groups.

5. A method for preparing the high thermal conductivity potting compound according to any one of claims 1 to 4, characterized in that, Includes the following steps: (a) The first vinyl MQ silicone resin, hydroxyl-terminated vinyl silicone oil, thermally conductive filler, dispersant, inorganic flame retardant and anti-settling agent in the formulation amount are thoroughly mixed, and then the vinyl polysiloxane and platinum catalyst in the formulation amount are added and mixed to obtain component A; (b) The formulation amounts of second vinyl MQ silicone resin, hydroxyl-terminated vinyl silicone oil, hydrogen-containing silicone oil, thermally conductive filler, dispersant, inorganic flame retardant and anti-settling agent are mixed to obtain component B; (c) Mix the components A and B together and cure at 120°C for 1 hour.

Images