Organic silicon pouring sealant and preparation method thereof

Abstract

The invention relates to a preparation method of a pouring sealant, in particular to an organic silicon pouring sealant and a preparation method thereof. The organic silicon pouring sealant is composed of a component A and a component B, the component A is composed of 700 to 1000 parts of vinyl silicone oil, 110 to 200 parts of hydrogen-containing silicone oil, 1500 parts of a filling material, 5 to 15 parts of silane and 0.01 to 0.1 part of an inhibitor, and the component B is composed of 700 to 1000 parts of vinyl silicone oil, 1500 parts of a filling material, 75 to 132 parts of silane and 4.6 to 8.1 parts of a catalyst. The organic silicon pouring sealant prepared by the invention has excellent thermal conductivity, flame retardance and insulativity, has high thermal conductivity, low viscosity and low mechanical strength compared with a traditional two-component organic silicon pouring sealant, and solves the difficulties that an electric appliance element is convenient to detach and maintain when damaged and an electronic component is not damaged.

Description

Technical Field

[0001] The present invention relates to a preparation method of potting glue, in particular to a silicone potting glue and a preparation method thereof. Background Art

[0002] Traditional potting materials are widely used in the encapsulation and protection of electronic components, mainly including types such as epoxy resin and polyurethane. However, such traditional potting glues often have high mechanical strength and viscosity while having high thermal conductivity, and it is not convenient to repair once the electronic components are damaged. Summary of the Invention

[0003] Under the above background art, the present invention provides a two-component silicone potting glue that not only ensures high thermal conductivity and flame retardancy but also has low mechanical properties and viscosity.

[0004] Technical Solution of the Present Invention:

[0005] . A silicone potting glue, which is composed of component A and component B;

[0006] Component A is composed of 700 - 1000 parts of vinyl silicone oil, 110 - 200 parts of hydrogen-containing silicone oil, 1500 parts of filler, 5 - 15 parts of silane, and 0.01 - 0.1 part of inhibitor, and component B is composed of 700 - 1000 parts of vinyl silicone oil, 1500 parts of filler, 75 - 132 parts of silane, and 4.6 - 8.1 parts of catalyst.

[0007] Preferably: The main chain of the vinyl silicone oil is polysiloxane (-Si-O-), and part of the methyl groups (-CH3) in the side chains are replaced by vinyl groups (-CH = CH2), and its structural formula is usually expressed as: Vi—(SiMeO)n—SiMe—Vi

[0008] Among them, Vi represents vinyl (CH2 = CH-), and Me is methyl.

[0009] Preferably: The main chain of the hydrogen-containing silicone oil is siloxane (-Si-O-), and part of the methyl groups (-CH3) in the side chains are replaced by hydrogen atoms (-H) to form Si-H bonds, and its typical structural formula can be expressed as: H—(SiMeO) n —SiMe—H, or part of the hydrogen-containing structure: Me3SiO—(SiMeHO) m —(SiMeO) n —SiMe.

[0010] Preferably: The filler is one or several of a hardening-type filler, a reinforcing-type filler, a heat-conducting-type filler, a flame-retardant-type filler, or an insulating-type filler.

[0011] Preferably, the inhibitor is one of ethynylcyclohexanol or 3,5-dimethyl-1-hexyn-3-ol.

[0012] Preferably, the silane is one or more of methyltrimethoxysilane, cetyltrimethoxysilane, KH-560 (γ-glycidoxypropyltrimethoxysilane), KH570 (γ-methacryloxypropyltrimethoxysilane).

[0013] Preferably, the catalyst is a platinum catalyst (Karstedt).

[0014] A method for preparing an organosilicon potting adhesive, comprising the following steps:

[0015] Step 1: Put vinyl silicone oil, silane, and filler into a reaction kettle, set the temperature of the reaction kettle to 120 °C, stir for 1.5 h under a vacuum state, and after the temperature of the reaction kettle drops to room temperature, add hydrogen-containing silicone oil and inhibitor, and stir for 1 h to obtain Component A;

[0016] Step 2: Put vinyl silicone oil, filler, and silane into a reaction kettle, set the temperature of the reaction kettle to 120 °C, stir for 1.5 h under a vacuum state, and after the temperature of the reaction kettle drops to room temperature, add a catalyst, and stir for 1 h to obtain Component B;

[0017] Step 3: Mix Component A and Component B in a weight ratio of 1:1, and stir for 15-20 min to make them evenly mixed, thus obtaining the organosilicon potting adhesive.

[0018] The present invention has the following beneficial effects:

[0019] The organosilicon potting adhesive prepared by the present invention has excellent thermal conductivity, flame retardancy, and insulation, and will not damage electronic components. Detailed implementation manners

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be described below through specific examples. However, it should be understood that these descriptions are only exemplary and do not intend to limit the scope of the present invention. In addition, in the following description, the descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0021] Detailed implementation manner one: An organosilicon potting adhesive in this implementation manner, the organosilicon potting adhesive is composed of Component A and Component B;

[0022] The component A consists of 700 - 1000 parts of vinyl silicone oil, 110 - 200 parts of hydrogen-containing silicone oil, 1500 parts of filler, 5 - 15 parts of silane, and 0.01 - 0.1 part of inhibitor. The component B consists of 700 - 1000 parts of vinyl silicone oil, 1500 parts of filler, 75 - 132 parts of silane, and 4.6 - 8.1 parts of catalyst.

[0023] Through the proportion design of each component and the separation of the two-component (A + B) system, this formulation realizes advantages in many aspects such as process controllability, performance adjustability, and cost optimization.

[0024] Specific Embodiment 2: An organosilicon potting adhesive in this embodiment. The main chain of the vinyl silicone oil is polysiloxane (-Si-O-), and part of the methyl groups (-CH3) in the side chains are replaced by vinyl groups (-CH=CH2). Its structural formula is usually expressed as: Vi—(SiMeO) n —SiMe—Vi

[0025] Among them, Vi represents vinyl (CH2=CH-), and Me is methyl.

[0026] The higher the vinyl content, the greater the crosslinking density, which may increase the viscosity, and its viscosity specifications vary from 50 to 10000 cSt. The vinyl silicone oil we use is one or several of different viscosity specifications.

[0027] This vinyl silicone oil structure realizes high crosslinking density, excellent thermal stability, and adjustable mechanical properties through side-chain vinyl substitution and polysiloxane main-chain design. It synergistically acts with components such as hydrogen-containing silicone oil, catalyst, and filler in the two-component potting adhesive system (A + B), and can meet the requirements of the electronic and electrical fields for high-performance potting materials.

[0028] Specific Embodiment 3: An organosilicon potting adhesive in this embodiment. The main chain of the hydrogen-containing silicone oil is siloxane (-Si-O-), and part of the methyl groups (-CH3) in the side chains are replaced by hydrogen atoms (-H) to form Si-H bonds. Its typical structural formula can be expressed as: H—(SiMeO) n —SiMe—H, or partial hydrogen-containing structure: Me3SiO—(SiMeHO) m —(SiMeO) n —SiMe.

[0029] The Si-H bond has high reactivity and can participate in reactions such as addition and condensation. The hydrogen content (i.e., the Si-H bond density) directly affects the crosslinking efficiency and material properties. The higher the hydrogen content, the faster the crosslinking speed, but excessive amount may lead to brittleness. Here, we use one or several of end-hydrogen-containing silicone oil and side-hydrogen-containing silicone oil with different hydrogen contents.

[0030] H—(SiMeO)n —SiMe—H: Simple structure but limited performance, suitable for low-end scenarios or auxiliary crosslinking;

[0031] Me3SiO—(SiMeHO) m —(SiMeO) n —SiMe3): Achieve high crosslinking density and process controllability through block design, suitable for the electronics and electrical fields.

[0032] Considering the crosslinking density, curing speed, and cost comprehensively, the side-chain hydrogen-containing type is preferably selected, and it can be compounded with the end-hydrogen type when necessary to optimize the fluidity.

[0033] Specific Embodiment 4: An organosilicon potting adhesive in this embodiment, where the filler is one or several of a hardening type filler, a reinforcing type filler, a heat-conducting type filler, a flame-retardant type filler, or an insulating type filler.

[0034] The filler is preferably aluminum hydroxide or alumina. Comparing with traditional fillers such as calcium carbonate and talcum powder: Although these fillers are inexpensive, they usually do not have the flame-retardant properties like aluminum hydroxide or the high thermal conductivity of alumina. In addition, the addition of aluminum hydroxide and alumina can also improve the electrical properties and mechanical properties of the material.

[0035] Comparing with fillers such as silica: Although silica can also provide a certain strengthening effect, in terms of thermal conductivity and mechanical strength, alumina is often superior. At the same time, the unique flame-retardant mechanism of aluminum hydroxide is difficult to replace by other fillers.

[0036] Specific Embodiment 5: An organosilicon potting adhesive in this embodiment, where the inhibitor is one of ethynylcyclohexanol or 3,5-dimethyl-1-hexyn-3-ol. Selecting ethynylcyclohexanol or 3,5-dimethyl-1-hexyn-3-ol as the inhibitor is mainly to precisely control the activity of the platinum catalyst, extend the operation time, and ensure the curing efficiency.

[0037] 3,5-dimethyl-1-hexyn-3-ol has low toxicity (LD50>2000mg / kg) and complies with the RoHS / REACH regulations. While sulfur / nitrogen-containing compounds may release harmful gases, the alkynol completely volatilizes or decomposes during the curing process and will not leave small molecules, avoiding causing yellowing of the material, a decrease in conductivity, or interfacial peeling.

[0038] Specific Embodiment 6: An organosilicon potting adhesive in this embodiment, where the silane is one or several of methyltrimethoxysilane, cetyltrimethoxysilane, KH-560 (γ-glycidoxypropyltrimethoxysilane), KH570 (γ-methacryloxypropyltrimethoxysilane).

[0039] Specific Embodiment Seven: An organosilicon potting adhesive in this embodiment, the catalyst is platinum catalyst (Karstedt). Using platinum catalyst (Karstedt) as the core of the curing system in the organosilicon potting adhesive can significantly improve the reaction efficiency, controllability and final performance of the material.

[0040] The Karstedt system has both high transparency, resistance to extreme environments and adjustable mechanical properties, and the addition curing mechanism does not require the release of small molecules, avoiding bubbles, shrinkage and interfacial delamination.

[0041] Specific Embodiment Eight: A preparation method of an organosilicon potting adhesive in this embodiment includes the following steps:

[0042] Step 1: Put vinyl silicone oil, silane and filler into a reaction kettle, set the temperature of the reaction kettle to 120 °C, stir for 1.5 h under vacuum, and after the temperature of the reaction kettle drops to room temperature, add hydrogen-containing silicone oil and inhibitor, and stir for 1 h to obtain Component A;

[0043] Step 2: Put vinyl silicone oil, filler and silane into a reaction kettle, set the temperature of the reaction kettle to 120 °C, stir for 1.5 h under vacuum, and after the temperature of the reaction kettle drops to room temperature, add the catalyst and stir for 1 h to obtain Component B;

[0044] Step 3: Mix Component A and Component B in a weight ratio of 1:1 and stir for 15 - 20 min to make them evenly mixed, then the organosilicon potting adhesive is obtained.

[0045] Example 1

[0046] A preparation method of an organosilicon potting adhesive includes the following steps:

[0047] Step 1: Weigh 400 g of 100 cSt vinyl silicone oil, 600 g of 500 cSt vinyl silicone oil, 1500 g of aluminum hydroxide, 5 g of methyltrimethoxysilane, and 160 g of terminal hydrogen-containing silicone oil with a hydrogen content of 85%, add them into a reaction kettle, under vacuum, start timing after heating to 120 °C, stir for 1.5 h, and after the temperature of the reaction kettle drops to 25 °C, add 0.8 g of ethynylcyclohexanol, and stir for 1 h under vacuum to obtain Component A;

[0048] Step 2: Weigh 400 g of 100 cSt vinyl silicone oil, 600 g of 500 cSt vinyl silicone oil, 1500 g of aluminum hydroxide, 5 g of methyltrimethoxysilane, and 120 g of KH560 (γ-glycidoxypropyltrimethoxysilane), add them into a reaction kettle, under vacuum, start timing after heating to 120 °C, stir for 1.5 h, and after the temperature of the reaction kettle drops to 25 °C, add 6.3 g of platinum catalyst, and stir for 1 h under vacuum to obtain Component B;

[0049] Step 3: Mix Component A and Component B in a weight ratio of 1:1 and stir for 15 - 20 min to make them evenly mixed, thus obtaining the silicone potting adhesive.

[0050] Example 2

[0051] A preparation method of a silicone potting adhesive, comprising the following steps:

[0052] Step 1: Weigh 400 g of vinyl silicone oil with a viscosity of 100 cSt, 600 g of vinyl silicone oil with a viscosity of 500 cSt, 1500 g of aluminum hydroxide, 12 g of cetyltrimethoxysilane, and 160 g of side hydrogen-containing silicone oil with a hydrogen content of 85%. Add them to a reaction kettle. Under a vacuum condition, heat up to 120 °C and start timing, stir for 1.5 h. After the temperature of the reaction kettle drops to 25 °C, add 0.48 g of ethynylcyclohexanol and stir for 1 h under a vacuum condition to obtain Component A;

[0053] Step 2: Weigh 400 g of vinyl silicone oil with a viscosity of 100 cSt, 600 g of vinyl silicone oil with a viscosity of 500 cSt, 1500 g of aluminum hydroxide, 12 g of cetyltrimethoxysilane, and 120 g of KH560 (γ-glycidoxypropyltrimethoxysilane). Add them to a reaction kettle. Under a vacuum condition, heat up to 120 °C and start timing, stir for 1.5 h. After the temperature of the reaction kettle drops to 25 °C, add 4.6 g of platinum catalyst and stir for 1 h under a vacuum condition to obtain Component B;

[0054] Step 3: Mix Component A and Component B in a weight ratio of 1:1 and stir for 15 - 20 min to make them evenly mixed, thus obtaining the silicone potting adhesive.

[0055] Example 3

[0056] A preparation method of a silicone potting adhesive, comprising the following steps:

[0057] Step 1: Weigh 400 g of vinyl silicone oil with a viscosity of 100 cSt, 300 g of vinyl silicone oil with a viscosity of 1000 cSt, 1500 g of alumina, 7 g of methyltrimethoxysilane, 110 g of terminal hydrogen-containing silicone oil with a hydrogen content of 85%, and 90 g of side hydrogen-containing silicone oil with a hydrogen content of 36%. Add them to a reaction kettle. Under a vacuum condition, heat up to 120 °C and start timing, stir for 1.5 h. After the temperature of the reaction kettle drops to 25 °C, add 1.1 g of ethynylcyclohexanol and stir for 1 h under a vacuum condition to obtain Component A;

[0058] Step 2: Weigh 400 g of vinyl silicone oil with a viscosity of 100 cSt, 300 g of vinyl silicone oil with a viscosity of 1000 cSt, 1500 g of alumina, 7 g of methyltrimethoxysilane, and 80 g of KH570 (γ-methacryloxypropyltrimethoxysilane). Add them to the reaction kettle. Under a vacuum condition, heat up to 120 °C and then start timing. Stir for 1.5 h. After the temperature of the reaction kettle drops to 25 °C, add 8.1 g of platinum catalyst. Stir for 1 h under a vacuum condition to obtain Component B;

[0059] Step 3: Mix Component A and Component B in a weight ratio of 1:1 and stir for 15 - 20 min to make them evenly mixed, thus obtaining the silicone potting adhesive.

[0060] Example 4

[0061] A preparation method of a silicone potting adhesive includes the following steps:

[0062] Step 1: Weigh 300 g of vinyl silicone oil with a viscosity of 200 cSt, 500 g of vinyl silicone oil with a viscosity of 500 cSt, 750 g of aluminum hydroxide, 750 g of alumina, 15 g of cetyltrimethoxysilane, and 130 g of terminal hydrogen-containing silicone oil with a hydrogen content of 75%. Add them to the reaction kettle. Under a vacuum condition, heat up to 120 °C and then start timing. Stir for 1.5 h. After the temperature of the reaction kettle drops to 25 °C, add 0.6 g of 3,5-dimethyl-1-hexyne-3-ol. Stir for 1 h under a vacuum condition to obtain Component A;

[0063] Step 2: Weigh 300 g of vinyl silicone oil with a viscosity of 200 cSt, 500 g of vinyl silicone oil with a viscosity of 500 cSt, 750 g of aluminum hydroxide, 750 g of alumina, 15 g of cetyltrimethoxysilane, and 120 g of KH560 (γ-glycidoxypropyltrimethoxysilane). Add them to the reaction kettle. Under a vacuum condition, heat up to 120 °C and then start timing. Stir for 1.5 h. After the temperature of the reaction kettle drops to 25 °C, add 5.8 g of platinum catalyst. Stir for 1 h under a vacuum condition to obtain Component B;

[0064] Step 3: Mix Component A and Component B in a weight ratio of 1:1 and stir for 15 - 20 min to make them evenly mixed, thus obtaining the silicone potting adhesive.

[0065] Example 5

[0066] A preparation method of a silicone potting adhesive includes the following steps:

[0067] Step 1: Weigh 600 g of vinyl silicone oil with a viscosity of 200 cSt, 400 g of vinyl silicone oil with a viscosity of 500 cSt, 1500 g of aluminum hydroxide, 8 g of methyltrimethoxysilane, 110 g of terminal hydrogen-containing silicone oil with a hydrogen content of 75%, and 80 g of side hydrogen-containing silicone oil with a hydrogen content of 36%. Add them to the reaction kettle. Under a vacuum condition, heat up to 120 °C and then start timing. Stir for 1.5 h. After the temperature of the reaction kettle drops to 25 °C, add 0.78 g of 3,5-dimethyl-1-hexyne-3-ol. Stir for 1 h under a vacuum condition to obtain Component A;

[0068] Step 2: Weigh 600 g of vinyl silicone oil with a viscosity of 200 cSt, 400 g of vinyl silicone oil with a viscosity of 500 cSt, 1500 g of aluminum hydroxide, 8 g of methyltrimethoxysilane, and 80 g of KH570 (γ-methacryloxypropyltrimethoxysilane). Add them to the reaction kettle. Under a vacuum condition, heat up to 120 °C and then start timing. Stir for 1.5 h. After the temperature of the reaction kettle drops to 25 °C, add 5.2 g of platinum catalyst. Stir for 1 h under a vacuum condition to obtain Component B;

[0069] Step 3: Mix Component A and Component B in a weight ratio of 1:1 and stir for 15 - 20 min to make them evenly mixed, thus obtaining the silicone potting adhesive.

[0070] Example 6

[0071] A preparation method of a silicone potting adhesive, comprising the following steps:

[0072] Step 1: Weigh 200 g of vinyl silicone oil with a viscosity of 1000 cSt, 600 g of vinyl silicone oil with a viscosity of 500 cSt, 1500 g of aluminum hydroxide, 15 g of cetyltrimethoxysilane, 180 g of terminal hydrogen-containing silicone oil with a hydrogen content of 75%, and 70 g of side hydrogen-containing silicone oil with a hydrogen content of 36%. Add them to the reaction kettle. Under a vacuum condition, heat up to 120 °C and then start timing. Stir for 1.5 h. After the temperature of the reaction kettle drops to 25 °C, add 0.8 g of ethynylcyclohexanol. Stir for 1 h under a vacuum condition to obtain Component A;

[0073] Step 2: Weigh 200 g of vinyl silicone oil with a viscosity of 1000 cSt, 600 g of vinyl silicone oil with a viscosity of 500 cSt, 1500 g of aluminum hydroxide, 15 g of cetyltrimethoxysilane, and 60 g of KH570 (γ-methacryloxypropyltrimethoxysilane). Add them to the reaction kettle. Under a vacuum condition, heat up to 120 °C and then start timing. Stir for 1.5 h. After the temperature of the reaction kettle drops to 25 °C, add 7.2 g of platinum catalyst. Stir for 1 h under a vacuum condition to obtain Component B;

[0074] Step 3: Mix Component A and Component B in a weight ratio of 1:1 and stir for 15 - 20 minutes to make them evenly mixed, thus obtaining the silicone potting adhesive.

[0075] Project Case 1 Case 2 Case 3 Case 4 Case 5 Case 6 Thermal conductivity (W / mk) 4.98 5.37 4.78 4.69 5.26 5.77 Tensile strength (MPa) 1.03 1.06 1.09 1.37 1.25 1.03 Viscosity (cp) 21388 24100 20899 19366 20575 23330

[0076] It should be noted that in the above embodiments, as long as the technical solutions are not contradictory, they can be permutated and combined. Those skilled in the art can exhaust all possibilities based on the mathematical knowledge of permutation and combination. Therefore, the present invention will not explain the technical solutions after permutation and combination one by one, but it should be understood that the technical solutions after permutation and combination have been disclosed by the present invention.

[0077] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A silicone potting adhesive, characterized in that: The silicone potting adhesive consists of component A and component B; Component A consists of 700 - 1000 parts of vinyl silicone oil, 110 - 200 parts of hydrogen-containing silicone oil, 1500 parts of filler, 5 - 15 parts of silane, and 0.01 - 0.1 part of inhibitor. Component B consists of 700 - 1000 parts of vinyl silicone oil, 1500 parts of filler, 75 - 132 parts of silane, and 4.6 - 8.1 parts of catalyst.

2. The silicone potting adhesive according to claim 1, wherein: The main chain of the vinyl silicone oil is polysiloxane (-Si-O-), and the methyl groups (-CH3) of some side chains are replaced by vinyl groups (-CH=CH2). Its structural formula is: Vi—(SiMeO) n —SiMe—Vi Among them, Vi represents vinyl (CH2=CH-), and Me represents methyl.

3. An organosilicon potting adhesive according to claim 1, characterized in that: The main chain of the hydrogen-containing silicone oil is siloxane (-Si-O-), and the methyl groups (-CH3) in some side chains are replaced by hydrogen atoms (-H) to form Si-H bonds. Its structural formula can be expressed as: H—(SiMeO) n —SiMe—H, or a partial hydrogen-containing structure: Me3SiO—(SiMeHO) m —(SiMeO) n —SiMe.

4. The silicone potting adhesive according to claim 1, characterized in that: The filler is one or several of a hardening type filler, a reinforcing type filler, a heat-conducting type filler, a flame-retardant type filler, or an insulating type filler.

5. An organosilicon potting adhesive according to claim 1, characterized in that: The inhibitor is one of acetylene cyclohexanol or 3,5-dimethyl-1-hexyne-3-ol.

6. The silicone potting adhesive according to claim 1, wherein: The silane is one or several of methyltrimethoxysilane, cetyltrimethoxysilane, KH-560 (γ-glycidoxypropyltrimethoxysilane), KH570 (γ-methacryloxypropyltrimethoxysilane).

7. An organosilicon potting adhesive according to claim 1, characterized in that: The catalyst is platinum catalyst Karstedt.

8. A preparation method of an organosilicon potting adhesive, characterized in that, It includes the following steps: Step 1: Put vinyl silicone oil, silane, and filler into a reaction kettle. Set the temperature of the reaction kettle to 120°C and stir for 1.5 h under a vacuum state. After the temperature of the reaction kettle drops to room temperature, add hydrogen-containing silicone oil and inhibitor and stir for 1 h to obtain component A; Step 2: Put vinyl silicone oil, filler, and silane into a reaction kettle. Set the temperature of the reaction kettle to 120°C and stir for 1.5 h under a vacuum state. After the temperature of the reaction kettle drops to room temperature, add the catalyst and stir for 1 h to obtain component B; Step 3: Mix component A and component B in a weight ratio of 1:1 and stir for 15 - 20 min to make them evenly mixed, then the silicone potting adhesive is obtained.