Low-hardness high-adhesiveness acrylate heat-conducting gasket and preparation method thereof
By adding aliphatic polyurethane acrylate and other components with low glass transition temperature to the thermal conductivity gasket, the problem of silicon pollution and thermal conductivity balance in long-term use of existing thermal conductivity gaskets is solved, and the combination of low hardness, high adhesion and good thermal conductivity is achieved, reducing the risk of environmental pollution.
Patent Information
- Application Number
- CN202510220862.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-27
- Publication Date
- 2025-05-23
AI Technical Summary
Existing thermal conductivity gaskets will precipitate silicone oil during long-term use, resulting in silicon contamination and short circuits of electronic products, while it is difficult to maintain good flexibility and thermal conductivity balance.
By adding aliphatic polyurethane acrylate with low glass transition temperature (Tg), combined with toughening agents, diluted monomers, initiators, thermal conductive powders, antioxidants and defoamers, low hardness and high adhesion acrylate thermal gaskets are prepared, avoiding the use of silicone oil, and improving the balance of hardness, flexibility and thermal conductivity.
The thermal conductivity gasket is achieved with a lower hardness and better flexibility, and its thermal conductivity is enhanced, avoiding silicon pollution and short circuit problems, and does not contain organic solvents, reducing damage to users and environmental pollution.
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of thermal conductive materials, and in particular to a low-hardness and high-adhesiveness acrylic thermal conductive pad and a preparation method thereof. Background Art
[0002] With the rapid development of industries such as smart electronics, 5G communications, the automotive industry, and high-end manufacturing, more sophisticated electronic devices need to be integrated into smaller components to a higher degree, which results in high heat accumulation in a limited, narrow, and compact operating space. In order to increase the heat dissipation capacity between components, thermal conductive materials need to be installed on the heat-generating parts of these devices.
[0003] At present, the thermal conductive materials used for heat dissipation on the market include thermal conductive adhesives, thermal conductive pads, thermal conductive silicone grease, thermal conductive gel, thermal conductive phase change materials, etc. There are currently two main types of thermal conductive pads: silicone system and acrylate system. The thermal conductive materials of the silicone system will precipitate silicone oil and volatilize certain small molecular siloxane substances during long-term use, which will pollute electronic devices and may cause internal short circuits in electronic products, thereby affecting their use. At the same time, no matter which type of thermal conductive pad is used, it needs to have the ability to maintain a good shape, retain excellent flexibility and have good thermal conductivity. This balance is often difficult to grasp. Summary of the invention
[0004] In order to overcome the shortcomings of the prior art and avoid the above-mentioned traditional technical problem of silicon contamination, one of the purposes of the present invention is to provide a low-hardness and high-adhesion acrylic thermal conductive gasket to solve the above-mentioned traditional technical problems. It provides the ability to maintain a certain shape of adhesion by adding aliphatic polyurethane acrylate with a low glass transition temperature (Tg), improves the balance between hardness, flexibility and thermal conductivity, and thus enhances its performance.
[0005] The second object of the present invention is to provide a method for preparing the above-mentioned low-hardness and high-adhesion acrylic thermally conductive gasket.
[0006] One of the purposes of the present invention is achieved by the following technical solution: A low-hardness and high-adhesive acrylic thermally conductive pad comprises the following components in parts by weight: 2-10 parts of toughening agent, 3-10 parts of diluent monomer, 0.01-1 part of acrylate polymer, 0.05-2 parts of initiator, 90-150 parts of thermal conductive powder, 0.5-1 part of antioxidant, 0.01-1 part of defoaming agent, wherein the acrylate polymer is an aliphatic polyurethane acrylate with a low glass transition temperature (Tg).
[0007] In the present invention, a small amount of low glass transition temperature acrylic polymer is added to provide an adhesive ability to maintain a certain shape, and then toughening agents, diluent monomers, initiators, thermal conductive powders, antioxidants, defoaming agents and other ingredients are reasonably matched. Without using silicone oil, traditional problems such as silicone oil precipitation, small molecular siloxane volatilization, and silicon pollution are avoided to improve the balance of hardness, flexibility and thermal conductivity, so that the product has lower hardness, better flexibility, and enhanced thermal conductivity.
[0008] In the present invention, the weight proportion of the toughening agent may be 2 parts, 4 parts, 6 parts, 8 parts, 10 parts, etc.
[0009] The weight proportions of the diluent monomer may be 3 parts, 5 parts, 7 parts, 9 parts, 10 parts, etc.
[0010] The weight proportions of the acrylic acid ester polymer may be 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.4, 0.6, 0.8, 1, etc.
[0011] The weight proportion of the initiator can be 0.05 parts, 0.08 parts, 0.1 parts, 0.2 parts, 0.4 parts, 0.6 parts, 0.8 parts, 1 parts, 1.2 parts, 1.5 parts, 2 parts, etc.
[0012] The weight proportions of the thermally conductive powder may be 90 parts, 100 parts, 110 parts, 120 parts, 130 parts, 140 parts, 150 parts, etc.
[0013] The weight proportion of the antioxidant can be 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1 part, etc.
[0014] The weight proportions of the defoaming agent can be 0.01 part, 0.02 part, 0.03 part, 0.04 part, 0.05 part, 0.06 part, 0.07 part, 0.08 part, 0.09 part, 0.1 part, 0.2 part, 0.4 part, 0.6 part, 0.8 part, 1 part, etc.
[0015] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.
[0016] Further, the Tg of the aliphatic polyurethane acrylate is -50°C to -4°C, for example, -50°C, -45°C, -40°C, -35°C, -30°C, -25°C, -20°C, -15°C, -10°C, -5°C, -4°C, etc.
[0017] Furthermore, the aliphatic polyurethane acrylate with low glass transition temperature (Tg) is one or more of SD850, SD8816B, SD8602, SD9211, BR-3741AJ, and BR-5541M.
[0018] Among the above, SD 850 is a difunctional polyurethane acrylate with strong cohesive and adhesive strength, purchased from Guangzhou Songda New Material Technology Co., Ltd.
[0019] SD8816B is a rubber-modified elastomer with good resilience, good water boiling resistance of its rubber layer, high light transmittance, good weather resistance, good softness, good high temperature and humidity resistance, and good high and low temperature impact resistance. It was purchased from Guangzhou Songda New Material Technology Co., Ltd.
[0020] SD8602 is a difunctional polyurethane acrylate, which has strong cohesive and adhesive strength and was purchased from Guangzhou Songda New Material Technology Co., Ltd.
[0021] SD9211 is a difunctional polyester acrylate resin, which has the characteristics of low viscosity and good toughness. It was purchased from Guangzhou Songda New Material Technology Co., Ltd.
[0022] BR-3741AJ, purchased from Bomar Corporation.
[0023] BR-5541M, purchased from Bomar Company.
[0024] Furthermore, the mass ratio of the acrylate polymer to the diluent monomer is 1:(7-13), for example, it can be 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, etc.
[0025] Furthermore, the toughening agent is a mixture of at least one or more of a liquid polyolefin with a molecular weight of 3000-4000 and a hydroxyl-terminated polyolefin with a molecular weight of 1000-3000.
[0026] Furthermore, the liquid polyolefin is one or more of metallocene polyolefin, ethylene-vinyl acetate copolymer, polyisobutylene, poly-α-olefin, and liquid copolymer olefin.
[0027] Furthermore, the hydroxy-terminated polyolefin is one or more of hydroxy-terminated polybutadiene, hydroxy-terminated polyisoprene, hydroxy-terminated polyethylene-butadiene copolymer, hydroxy-terminated ethylene-propylene-butadiene copolymer, and hydroxy-terminated isoprene-butadiene copolymer.
[0028] Furthermore, the diluent monomer is at least one or more mixtures of polyether polyols with a molecular weight less than or equal to 500 and lauryl acrylate.
[0029] Furthermore, the initiator is a peroxide initiator, specifically a mixture of one or more of tert-butyl peroxybenzoate and tert-butyl peroxy-2-ethylhexanoate.
[0030] Furthermore, the thermal conductive powder is alumina powder, specifically a mixture of one or more of Jinge New Materials DP-075, DRHY-327, and DRHY-381.
[0031] Furthermore, the antioxidant is at least one of a phenolic antioxidant or a phosphite antioxidant. Specifically, the phenolic antioxidant is antioxidant 1010 and / or antioxidant 1076; and the phosphite antioxidant is antioxidant 168.
[0032] Furthermore, the defoamer is one or a mixture of silicone or non-silicon defoamers, specifically one or a mixture of BYK-333, BYK-051, BYK-066N, KSZ-169A, Silok 8244, Silok 4084, and AKN-3003.
[0033] The second object of the present invention is achieved by adopting the following technical solution: A method for preparing a low-hardness and high-adhesion acrylic thermally conductive pad comprises the following steps: S1: degassing, stirring and mixing the formulated amount of toughening agent, diluent monomer, acrylate polymer and antioxidant in a gravity planetary mixer to obtain a first mixture; S2: adding the initiator, thermal conductive powder and defoaming agent in the formula to the first mixture, stirring evenly in a gravity planetary mixer and evacuating the mixture to obtain a second mixture; S3: Pour the second mixture into a fixed mold, and then put the mold into an oven at 120-150° C. and bake for 20 min-40 min to form an acrylic thermally conductive gasket.
[0034] Compared with the prior art, the present invention has the following beneficial effects: 1. The low-hardness and high-adhesion acrylic thermally conductive gasket of the present invention provides the adhesive ability to maintain a certain shape by adding a small amount of low glass transition temperature acrylic polymer, and then reasonably matches toughening agent, diluent monomer, initiator, thermal conductive powder, antioxidant, defoaming agent and other ingredients. Without using silicone oil, traditional problems such as silicone oil precipitation, small molecular siloxane volatilization, silicon pollution, etc. are avoided to improve the balance of hardness, flexibility and thermal conductivity, so that the product has lower hardness, better flexibility, and enhanced thermal conductivity.
[0035] 2. The low-hardness and high-adhesion acrylic thermally conductive pad of the present invention does not contain organic solvents, thereby reducing harm to users and reducing environmental pollution. DETAILED DESCRIPTION
[0036] The present invention is further described below in conjunction with specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form a new embodiment.
[0037] The sources of some components in the embodiments and comparative examples are as follows: Toughener 1: metallocene polypropylene (mPP) with a molecular weight of 3000-4000, purchased from Ningbo Zhongao Shenzhou Chemical Co., Ltd. Toughening agent 2: 1000-3000 molecular weight hydroxyl-terminated polyisoprene, purchased from Hubei Diehua New Materials Technology Co., Ltd.; Diluent 1: polypropylene glycol, 200-250 molecular weight, purchased from Haian Petrochemical Plant, Jiangsu Province; Diluent 2: dodecyl methacrylate, purchased from Guangdong Fangxin Biotechnology Co., Ltd.; Acrylate polymer 1: SD 850, purchased from Guangzhou Songda New Material Technology Co., Ltd.
[0038] Acrylate polymer 2: SD8816B, purchased from Guangzhou Songda New Material Technology Co., Ltd.
[0039] Acrylate polymer 3: BR-5541M, purchased from Bomar Corporation.
[0040] Initiator: tert-butyl perbenzoate, Shandong Jinghao Chemical Co., Ltd.; Thermal conductive powder: DP-075, Guangdong Jinge New Materials Co., Ltd. Antioxidant: Antioxidant 1076, Guangzhou Yinuo Chemical Technology Co., Ltd.; Defoaming agent: BYK-333, Yinhuang (Shanghai) Industrial Co., Ltd.
[0041] In the following examples, the preparation method of the low-hardness and high-adhesion acrylic thermally conductive pad is as follows: S1: degassing, stirring and mixing the formulated amount of toughening agent, diluent monomer, acrylate polymer and antioxidant in a gravity planetary mixer to obtain a first mixture; S2: adding the initiator, thermal conductive powder and defoaming agent in the formula to the first mixture, stirring evenly in a gravity planetary mixer and evacuating the mixture to obtain a second mixture; S3: Pour the second mixture into a fixed mold, then place the mold in a 130° C. oven and bake for 30 minutes to form an acrylic thermally conductive gasket.
[0042] Example 1 A low-hardness and high-adhesion acrylic thermally conductive pad comprises the following components in parts by weight: 3.28 parts of toughening agent 1, 3.28 parts of diluting monomer 2, 0.44 parts of acrylate polymer 1, 0.82 parts of initiator, 90.93 parts of thermal conductive powder, 0.71 parts of antioxidant, and 0.53 parts of defoaming agent.
[0043] Example 2 A low-hardness and high-adhesion acrylic thermally conductive pad comprises the following components in parts by weight: 2.64 parts of toughening agent 1, 2.82 parts of diluent monomer 1, 1.75 parts of diluent monomer 2, 0.61 parts of acrylate polymer 1, 0.81 parts of initiator, 90.14 parts of thermal conductive powder, 0.70 parts of antioxidant, and 0.53 parts of defoaming agent.
[0044] Example 3 A low-hardness and high-adhesion acrylic thermally conductive pad comprises the following components in parts by weight: 3.2 parts of toughening agent 2, 5.32 parts of diluting monomer 1, 0.72 parts of acrylate polymer 2, 0.81 parts of initiator, 90.14 parts of thermal conductive powder, 0.70 parts of antioxidant, and 0.53 parts of defoaming agent.
[0045] Example 4 A low-hardness and high-adhesion acrylic thermally conductive pad comprises the following components in parts by weight: 5.6 parts of toughening agent 1, 6.82 parts of diluting monomer 2, 0.81 parts of acrylate polymer 3, 0.81 parts of initiator, 95.19 parts of thermal conductive powder, 0.70 parts of antioxidant, and 0.53 parts of defoaming agent.
[0046] The comparative examples are shown below: Comparative Example 1 does not contain acrylate polymer 3.63 parts of toughening agent 1, 3.63 parts of diluting monomer 2, 0.91 parts of initiator, 90.76 parts of thermal conductive powder, 0.60 parts of antioxidant, and 0.50 parts of defoaming agent.
[0047] The other component requirements and preparation methods are the same as those of Example 1.
[0048] Comparative Example 2 Increasing the amount of acrylic acid ester polymer 3.28 parts of toughening agent 1, 3.28 parts of diluting monomer 2, 2.5 parts of acrylate polymer 1, 0.82 parts of initiator, 90.93 parts of thermal conductive powder, 0.71 parts of antioxidant, and 0.53 parts of defoaming agent.
[0049] The other component requirements and preparation methods are the same as those of Example 1.
[0050] Comparative Example 3 Increasing the amount of diluent monomer 3.28 parts of toughening agent 1, 15 parts of diluting monomer 2, 0.44 parts of acrylate polymer 1, 0.82 parts of initiator, 90.93 parts of thermal conductive powder, 0.71 parts of antioxidant, and 0.53 parts of defoaming agent.
[0051] The other component requirements and preparation methods are the same as those of Example 1.
[0052] Performance Testing 1. Test objects: Examples 1-4, Comparative Examples 1-3.
[0053] 2. During the test, the thermal conductivity is measured in accordance with "ASTM D 5470-01 Characterization test for testing the thermal conductivity properties of thin thermally conductive solid electrical insulating materials", and the test standard for Shore 00 hardness is mainly based on ASTM D2240 standard.
[0054] 3. The test results are shown in Table 1 below.
[0055] Table 1 project Thermal conductivity W / mk HardnessShore oo Cured product formability Example 1 2.8 57 The solidified material has good molding degree, no deformation and elasticity Example 2 2.9 50 The solidified material has good molding degree, no deformation and elasticity Example 3 2.7 60 The solidified material has good molding degree, no deformation and elasticity Example 4 3.2 46 The solidified material has good molding degree, no deformation and elasticity Comparative Example 1 2.2 40 The cured product has poor molding, is easy to deform, and has no elasticity Comparative Example 2 2.5 43 The solidified material has poor molding, is easy to deform, and has no elasticity Comparative Example 3 2.6 83 The cured product has poor molding, is easy to deform, and has no elasticity The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.
Claims
1. A low-hardness and high-adhesion acrylic thermally conductive pad, characterized in that: The composition comprises the following components in parts by weight: 2-10 parts of toughening agent, 3-10 parts of diluent monomer, 0.01-1 part of acrylate polymer, 0.05-2 parts of initiator, 90-150 parts of thermal conductive powder, 0.5-1 part of antioxidant, 0.01-1 part of defoaming agent, wherein the acrylate polymer is an aliphatic polyurethane acrylate with a low glass transition temperature (Tg).
2. The low-hardness and high-adhesion acrylic thermally conductive pad according to claim 1, characterized in that: The Tg of the aliphatic polyurethane acrylate is -50°C to -4°C.
3. The low-hardness and high-adhesion acrylic thermally conductive pad according to claim 2, characterized in that: The aliphatic polyurethane acrylate with low glass transition temperature (Tg) is one or more of SD850, SD8816B, SD8602, SD9211, BR-3741AJ, and BR-5541M.
4. The low-hardness and high-adhesion acrylic thermally conductive pad according to claim 1, characterized in that: The mass ratio of the acrylic ester polymer to the diluent monomer is 1:(7-13).
5. The low-hardness and high-adhesion acrylic thermally conductive pad according to claim 1, characterized in that: The toughening agent is at least one or more mixtures of liquid polyolefin with a molecular weight of 3000-4000 and terminal hydroxyl polyolefin with a molecular weight of 1000-3000.
6. The low-hardness and high-adhesion acrylic thermally conductive pad according to claim 5, characterized in that: The liquid polyolefin is one or more of metallocene polyolefin, ethylene-vinyl acetate copolymer, polyisobutylene, polyα-olefin, and liquid copolymer olefin; the terminal hydroxyl polyolefin is one or more of terminal hydroxyl polybutadiene, terminal hydroxyl polyisoprene, terminal hydroxyl polyethylene-butadiene copolymer, terminal hydroxyl ethylene-propylene-butadiene copolymer, and terminal hydroxyl isoprene-butadiene copolymer.
7. The low-hardness and high-adhesion acrylic thermally conductive pad according to claim 1, characterized in that: The diluent monomer is at least one or a mixture of polyether polyol and lauryl acrylate; the initiator is a peroxide initiator; the antioxidant is at least one of a phenolic antioxidant or a phosphite antioxidant; and the defoamer is one or a mixture of silicone or non-silicon defoamers.
8. The low-hardness and high-adhesion acrylic thermally conductive pad according to claim 1, characterized in that: The thermally conductive powder is alumina powder.
9. The low-hardness and high-adhesion acrylic thermally conductive pad according to claim 8, characterized in that: The thermal conductive powder is a mixture of one or more of DP-075, DRHY-327 and DRHY-381.
10. A method for preparing a low-hardness and high-adhesion acrylic thermally conductive pad according to any one of claims 1 to 9, characterized in that: The steps include: S1: degassing, stirring and mixing the formulated amount of toughening agent, diluent monomer, acrylate polymer and antioxidant in a gravity planetary mixer to obtain a first mixture; S2: adding the initiator, thermal conductive powder and defoaming agent in the formula to the first mixture, stirring evenly in a gravity planetary mixer and evacuating the mixture to obtain a second mixture; S3: Pour the second mixture into a fixed mold, and then put the mold into an oven at 120-150° C. and bake for 20 min-40 min to form an acrylic thermally conductive gasket.