Addition type two-component low viscosity self-adhesive heat-conducting pouring sealant and preparation method thereof

Abstract

This invention discloses an addition-type two-component low-viscosity self-adhesive thermally conductive potting compound and its preparation method, belonging to the field of polymer materials technology. The potting compound is composed of component A and component B in a 1:1 mass ratio. Component A contains vinyl silicone oil, coupling agent, thermally conductive filler, and platinum catalyst; component B contains vinyl silicone oil, coupling agent, thermally conductive filler, hydrogen-containing silicone oil, and inhibitor. Through a specific ratio of raw materials and a step-by-step preparation process, the product has low viscosity (component A ≤ 12200 mPa·s, component B ≤ 11080 mPa·s), high self-adhesion (shear strength ≥ 1.1 MPa), and excellent thermal conductivity (thermal conductivity ≥ 0.6 W·m⁻¹·K⁻¹). It also has good air release after mixing and is suitable for potting precision components in new energy, electronics, and other fields, especially for the protection of IGBT modules and PE plastic parts.

Description

Technical Field

[0001] This invention relates to the field of thermally conductive potting compound technology, specifically to an addition-type two-component low-viscosity self-adhesive thermally conductive potting compound and its preparation method. Background Technology

[0002] As is well known, with the rapid development of the electronics and new energy industries, the performance requirements of potting compounds for electronic components are increasing. Among the existing thermally conductive potting compounds, polyurethane and epoxy resins have good adhesion, but poor high-temperature resistance. Although silicone potting compounds have advantages such as high temperature resistance and no crosslinking by-products, they generally have problems with poor flowability and insufficient self-adhesion, making it difficult to meet the potting needs of precision components (such as IGBT modules). Therefore, the development of a silicone potting compound with low viscosity, high self-adhesion and excellent thermal conductivity has become an urgent need in the industry. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides an addition-type two-component low-viscosity self-adhesive thermally conductive potting compound and its preparation method.

[0004] To achieve the above objectives, the present invention provides the following technical solution: an addition-curing two-component low-viscosity self-adhesive thermally conductive potting compound, composed of component A and component B in a mass ratio of 1:1, with the specific formulation as follows: Component A (parts by weight): 100 parts vinyl silicone oil, 0.2-5 parts coupling agent, 100-200 parts thermally conductive filler, 0.1-1 parts platinum catalyst; Component B (parts by weight): 100 parts vinyl silicone oil, 0.2-5 parts coupling agent, 130-250 parts thermally conductive filler, 0.2-2 parts hydrogen-containing silicone oil, and 0.1-2 parts inhibitor.

[0005] Raw material description: Vinyl silicone oil: Vinyl-terminated polyorganosiloxanes are selected, with a vinyl content of 0.2~1.2% and a viscosity of 300~3000 mPa·s, providing the basic framework and crosslinking sites for the system; Coupling agents: By modifying the surface, the compatibility between the filler and the matrix is ​​improved. A combination of various silane coupling agents is preferred to enhance the interfacial bonding force. Thermally conductive filler: 5μm spherical alumina, 10μm spherical alumina and 20μm hexagonal boron nitride are compounded in a specific ratio, and the gaps are filled by different particle size distributions to construct a high-efficiency thermally conductive network; Platinum catalyst: initiates addition crosslinking reaction and controls reaction rate; hydrogen-containing silicone oil acts as a crosslinking agent, providing silane-hydrogen bonds; inhibitors delay premature crosslinking during storage.

[0006] Preparation method: Preparation of Component A: Vinyl silicone oil, coupling agent, and thermally conductive filler are stirred in a vacuum mixer at room temperature for 2-6 hours to ensure initial dispersion; the temperature is raised to 100-150℃ and vacuum stirred for 1-5 hours to remove moisture and air bubbles; after cooling, platinum catalyst is added and vacuum stirred for 0.5-2 hours to obtain a uniform Component A. Preparation of component B: The same dispersion process as component A is used. After cooling, hydrogen-containing silicone oil and inhibitor are added, and the mixture is stirred under vacuum for 0.5 to 2 hours to obtain component B.

[0007] Compared with the prior art, the present invention provides an addition-type two-component low-viscosity self-adhesive thermally conductive potting compound and its preparation method, which has the following beneficial effects: This addition-curing two-component, low-viscosity, self-adhesive, thermally conductive potting compound and its preparation method optimize the viscosity of vinyl silicone oil and filler gradation, resulting in a product with low viscosity (component A ≤ 12200 mPa·s, component B ≤ 11080 mPa·s). After mixing, it exhibits good flowability, easily filling gaps in complex component structures, and excellent venting performance. The coupling agent and tackifying system work synergistically, achieving a shear strength ≥ 1.1 MPa for metal and PE plastic parts, meeting the bonding requirements of precision components. The compounded thermally conductive filler constructs a continuous thermally conductive network with a thermal conductivity ≥ 0.6 W·m⁻¹·K⁻¹, effectively dissipating the working heat of components. The 1:1 mixing ratio of the two components facilitates metering, and the preparation process requires no complex equipment, making it suitable for industrial production, especially showing significant application advantages in IGBT module potting in the new energy field. Detailed Implementation

[0008] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0009] This embodiment describes an addition-type two-component, low-viscosity, self-adhesive, thermally conductive potting compound, composed of two components, A and B, in parts by weight. The main preparation method includes the following steps: S1. Preparation of component A: Add 100 parts of vinyl silicone oil, 2 parts of silane coupling agent, and 150 parts of thermally conductive filler to a vacuum mixer and stir at room temperature for 4 hours; raise the temperature to 120°C, maintain vacuum conditions (<-0.08 MPa), stir for 2 hours, and then cool; add 0.5 parts of platinum catalyst, and stir under vacuum for 1 hour to obtain component A. S2. Preparation of component B: Add 100 parts of vinyl silicone oil, 2 parts of silane coupling agent, and 150 parts of thermally conductive filler to a vacuum mixer and stir at room temperature for 4 hours; raise the temperature to 120°C, maintain vacuum conditions (<-0.08 MPa), stir for 2 hours, and then cool; add 1 part of hydrogen-containing silicone oil and 0.2 parts of inhibitor, and stir under vacuum for 1 hour to obtain component B. Among them, the vinyl silicone oil has a vinyl content of 0.46% and a viscosity of 500 mPa·s; The silane coupling agent is vinyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane, and dimethyldiethoxysilane in a ratio of 1:1:1:1.

[0010] The thermally conductive filler contains alumina I: alumina II: boron nitride in a ratio of 3:6:1.

[0011] The hydrogen silane content in the hydrogen-containing silicone oil is 0.5%; The platinum catalyst contains 2500 ppm of platinum. Example

[0012] This embodiment describes an addition-type two-component, low-viscosity, self-adhesive, thermally conductive potting compound, composed of two components, A and B, in parts by weight. The main preparation method includes the following steps: S1. Preparation of component A: Add 100 parts of vinyl silicone oil, 2 parts of silane coupling agent, and 170 parts of thermally conductive filler to a vacuum mixer and stir at room temperature for 4 hours; raise the temperature to 120°C, maintain vacuum conditions (<-0.08 MPa), stir for 2 hours, and then cool; add 0.5 parts of platinum catalyst, and stir under vacuum for 1 hour to obtain component A. S2. Preparation of component B: Add 100 parts of vinyl silicone oil, 2 parts of silane coupling agent, and 170 parts of thermally conductive filler to a vacuum mixer and stir at room temperature for 4 hours; raise the temperature to 120°C, maintain vacuum conditions (<-0.08 MPa), stir for 2 hours, and then cool; add 1 part of hydrogen-containing silicone oil and 0.2 parts of inhibitor, and stir under vacuum for 1 hour to obtain component B. Among them, the vinyl silicone oil has a vinyl content of 0.46% and a viscosity of 500 mPa·s; The silane coupling agent is vinyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane, and dimethyldiethoxysilane in a ratio of 2:1:1:1.

[0013] The thermally conductive filler contains alumina I: alumina II: boron nitride in a ratio of 3:6:1.

[0014] The hydrogen silane content in the hydrogen-containing silicone oil is 0.5%; The platinum catalyst contains 2500 ppm of platinum. Example

[0015] This embodiment describes an addition-type two-component, low-viscosity, self-adhesive, thermally conductive potting compound, composed of two components, A and B, in parts by weight. The main preparation method includes the following steps: S1. Preparation of component A: Add 100 parts of vinyl silicone oil, 2 parts of silane coupling agent, and 150 parts of thermally conductive filler to a vacuum mixer and stir at room temperature for 4 hours; raise the temperature to 120°C, maintain vacuum conditions (<-0.08 MPa), stir for 2 hours, and then cool; add 0.5 parts of platinum catalyst, and stir under vacuum for 1 hour to obtain component A. S2. Preparation of component B: Add 100 parts of vinyl silicone oil, 2 parts of silane coupling agent, and 150 parts of thermally conductive filler to a vacuum mixer and stir at room temperature for 4 hours; raise the temperature to 120°C, maintain vacuum conditions (<-0.08 MPa), stir for 2 hours, and then cool; add 1 part of hydrogen-containing silicone oil and 0.2 parts of inhibitor, and stir under vacuum for 1 hour to obtain component B. Among them, the vinyl silicone oil has a vinyl content of 0.46% and a viscosity of 500 mPa·s; The silane coupling agent is vinyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane, and dimethyldiethoxysilane in a ratio of 2:1:1:1.

[0016] The thermally conductive filler contains alumina I: alumina II: boron nitride in a ratio of 3:5:2.

[0017] The hydrogen silane content in the hydrogen-containing silicone oil is 0.5%; The platinum catalyst contains 2500 ppm of platinum.

[0018] The addition-curing two-component low-viscosity self-adhesive thermally conductive potting compounds prepared in Examples 1-3 above were subjected to performance testing, and the test results are as follows: Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An addition-curing, two-component, low-viscosity, self-adhesive, thermally conductive potting compound, characterized in that: It is composed of component A and component B in a mass ratio of 1:

1. Component A, by weight, includes: 100 parts vinyl silicone oil, 0.2-5 parts coupling agent, 100-200 parts thermally conductive filler, and 0.1-1 parts platinum catalyst. Component B, by weight, includes: 100 parts vinyl silicone oil, 0.2-5 parts coupling agent, 130-250 parts thermally conductive filler, 0.2-2 parts hydrogen-containing silicone oil, and 0.1-2 parts inhibitor.

2. The addition-curing two-component low-viscosity self-adhesive thermally conductive potting compound according to claim 1, characterized in that: The vinyl silicone oil is a vinyl-terminated polyorganosiloxane with a vinyl content of 0.2-1.2% and a viscosity of 300-3000 mPa·s.

3. The addition-curing two-component low-viscosity self-adhesive thermally conductive potting compound according to claim 2, characterized in that: The coupling agent is one or more of vinyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane, and dimethyldiethoxysilane.

4. The addition-curing two-component low-viscosity self-adhesive thermally conductive potting compound according to claim 3, characterized in that: The thermally conductive filler is a composition of alumina I, alumina II, and boron nitride; alumina I is spherical alumina with an average particle size of 5 μm, alumina II is spherical alumina with an average particle size of 10 μm, and boron nitride is hexagonal boron nitride with an average particle size of 20 μm; the mass ratio of the three is 2~6:3~8:0.5~2.

5. The addition-curing two-component low-viscosity self-adhesive thermally conductive potting compound according to claim 4, characterized in that: The platinum catalyst is a platinum-divinyltetramethyldisiloxane complex with a platinum content of 2000~5000 ppm.

6. The addition-curing two-component low-viscosity self-adhesive thermally conductive potting compound according to claim 5, characterized in that: The hydrogen content of the hydrogen-containing silicone oil is 0.2-1.5%.

7. A method for preparing an addition-type two-component low-viscosity self-adhesive thermally conductive potting compound according to claims 1-6, characterized in that: Includes the following steps: S1. Preparation of component A: Add vinyl silicone oil, coupling agent, and thermally conductive filler to a vacuum mixer and stir at room temperature for 2-6 hours; heat to 100-150℃ and stir under vacuum for 1-5 hours; after cooling, add platinum catalyst and stir under vacuum for 0.5-2 hours to obtain component A. S2. Preparation of component B: Add vinyl silicone oil, coupling agent, and thermally conductive filler to a vacuum mixer and stir at room temperature for 2-6 hours; heat to 100-150℃ and stir under vacuum for 1-5 hours; after cooling, add hydrogen-containing silicone oil and inhibitor, and stir under vacuum for 0.5-2 hours to obtain component B.