Novel modified heat conduction material and preparation process thereof

Abstract

The invention discloses a novel modified heat conduction material and a preparation process thereof, the novel modified heat conduction material comprises the following components in percentage by mass: 37.1% of resin, 6.5% of graphite and 56.4% of a reaction aid, and the modified nylon 6-based composite material has the advantages of excellent mechanical property, heat conduction and heat dissipation performance, insulating property and flame retardant property, convenience in processing, low cost, easiness in industrialization and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of modified material preparation, and in particular to a novel modified thermal conductive material and a preparation process thereof. Background Art

[0002] Nylon engineering plastics are widely used in the electronics, automotive, construction, office equipment, machinery, aerospace and other industries due to their high performance advantages in durability, corrosion resistance, and heat resistance. Replacing steel and wood with plastic has become an international trend. As the fastest-growing field in the world's plastics industry, the development of nylon engineering plastics not only supports the country's pillar industries and modern high-tech industries, but also promotes the transformation of traditional industries and the adjustment of product structures. At present, traditional nylon 6 materials still have significant limitations in some aspects and urgently need to be optimized through modification technology. Summary of the Invention

[0003] The purpose of the present invention is to provide a new type of modified thermal conductive material and its preparation process. The modified nylon 6-based composite material has excellent mechanical properties, thermal conductivity and heat dissipation properties, insulation properties and flame retardancy, and has the advantages of easy processing, low cost and easy industrialization.

[0004] A novel modified thermal conductive material provided by the present invention includes, by mass percentage, 37.1% of resin, 6.5% of graphite, and 56.4% of a reaction aid.

[0005] Furthermore, the resin is nylon 6 (polycaprolactam).

[0006] Furthermore, the reaction aid includes a combination of at least two or more of a toughening agent, a flame retardant, a colorant, a lubricant, and an antioxidant.

[0007] Furthermore, the antioxidant includes two kinds of agents: phosphorous acid solution and N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexanediamine.

[0008] Furthermore, the toughening agent is maleic anhydride grafted polyolefin elastomer, the flame retardant is magnesium hydroxide, the colorant is carbon black, and the lubricant is pentaerythritol stearate.

[0009] The present invention also provides a process for preparing the novel modified thermal conductive material as described above, comprising the steps of: S1: provides nylon 6; S2: Place nylon 6 in an oven and dry at 80-90°C for 2-4 hours; S3: providing 3% by weight of a toughening agent and 0.5% by weight of a phosphorous acid solution, and weighing 37.1% by weight of nylon 6 dried in step S2, the toughening agent and the phosphorous acid solution in step S3, and adding them together into a double-screw ribbon mixer, mixing for 10-15 minutes, and then removing them for later use; S4: Weigh 12.5% ​​by weight of magnesium hydroxide, 6.5% by weight of graphite, 0.5% by weight of pentaerythritol stearate, 0.2% by weight of carbon black, and 0.2% by weight of N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexanediamine, add the mixture to a conical mixer, mix for 20-30 minutes, and then remove from the mixer for later use; S5: Provide three loss-in-weight scales, add the two mixed materials obtained in step S3 and step S4 to two of the loss-in-weight scales respectively, and weigh 40% by mass of magnesium hydroxide and add it to the third loss-in-weight scale; S6: providing a twin-screw extruder, wherein the discharge ports of the three loss-in-weight scales in step S5 are connected to the feed port of the twin-screw extruder, and the three loss-in-weight scales discharge materials in a ratio of 40%, 20%, and 40%; S7: The mixed material in step S5 and magnesium hydroxide are kneaded in a twin-screw extruder and then cut into uniform particles.

[0010] Furthermore, after step S7, the method further includes the following steps: The uniform particles are screened through a vibrating screen to remove large particles and powder to obtain composite material particles of uniform size; the screened composite material of uniform size enters the homogenization bin through a vacuum feeder to further evenly mix the finished products in different time periods, and the homogenization time is 1-3 hours.

[0011] The beneficial effects of the present invention are: The obtained modified thermal conductive material has excellent mechanical properties, thermal conductivity and heat dissipation properties, insulation properties and flame retardancy, and has the advantages of convenient processing, low cost and easy industrialization. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a process flow chart of the preparation process of the new modified thermal conductive material described in an embodiment of the present invention. DETAILED DESCRIPTION

[0013] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0014] The present invention provides a novel modified thermal conductive material, which comprises, by mass percentage, 37.1% of resin, 6.5% of graphite and 56.4% of a reaction aid.

[0015] The resin is nylon 6 (polycaprolactam).

[0016] The reaction aid includes a combination of at least two of a toughening agent, a flame retardant, a colorant, a lubricant, and an antioxidant.

[0017] The antioxidants include phosphorous acid solution and N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexanediamine.

[0018] The toughening agent is maleic anhydride grafted polyolefin elastomer, the flame retardant is magnesium hydroxide, the colorant is carbon black, and the lubricant is pentaerythritol stearate.

[0019] The present invention also provides a preparation process of the novel modified thermal conductive material as described above, comprising the steps of: S1: provides nylon 6; S2: Place nylon 6 in an oven and dry at 80-90°C for 2-4 hours; S3: providing 3% by weight of a toughening agent and 0.5% by weight of a phosphorous acid solution, and weighing 37.1% by weight of nylon 6 dried in step S2, the toughening agent and the phosphorous acid solution in step S3, and adding them together into a double-screw ribbon mixer, mixing for 10-15 minutes, and then removing them for later use; S4: Weigh 12.5% ​​by weight of magnesium hydroxide, 6.5% by weight of graphite, 0.5% by weight of pentaerythritol stearate, 0.2% by weight of carbon black, and 0.2% by weight of N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexanediamine, add the mixture to a conical mixer, mix for 20-30 minutes, and then remove from the mixer for later use; S5: Provide three loss-in-weight scales, add the two mixed materials obtained in step S3 and step S4 to two of the loss-in-weight scales respectively, and weigh 40% by mass of magnesium hydroxide and add it to the third loss-in-weight scale; S6: providing a twin-screw extruder, wherein the discharge ports of the three loss-in-weight scales in step S5 are connected to the feed port of the twin-screw extruder, and the three loss-in-weight scales discharge materials in a ratio of 40%, 20%, and 40%; S7: The mixed material in step S5 and magnesium hydroxide are kneaded in a twin-screw extruder and then cut into uniform particles.

[0020] After step S7, the method further includes the following steps: The uniform particles are screened through a vibrating screen to remove large particles and powder to obtain composite material particles of uniform size; the screened composite material of uniform size enters the homogenization bin through a vacuum feeder to further evenly mix the finished products in different time periods, and the homogenization time is 1-3 hours.

[0021] Example 1 A new modified thermal conductive material comprises, by mass percentage, 37.1% of resin, 6.5% of graphite, and 56.4% of reaction aid, wherein the resin is nylon 6 (polycaprolactam), the reaction aid comprises a combination of at least two of a toughening agent, a flame retardant, a colorant, a lubricant, and an antioxidant, the antioxidant comprising two types of antioxidants: a phosphorous acid solution and N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexanediamine, the toughening agent is a maleic anhydride grafted polyolefin elastomer, the flame retardant is magnesium hydroxide, the colorant is carbon black, and the lubricant is pentaerythritol stearate.

[0022] The preparation process of the novel modified thermal conductive material comprises the following steps: S1: provides nylon 6; S2: Place nylon 6 in an oven and dry at 85°C for 3 hours; S3: providing 3% by weight of a toughening agent and 0.5% by weight of a phosphorous acid solution, and weighing 37.1% by weight of nylon 6 dried in step S2, the toughening agent and the phosphorous acid solution in step S3, and adding them together into a double-screw ribbon mixer, mixing for 12 minutes, and then removing them for later use; S4: Weigh 12.5% ​​by weight of magnesium hydroxide, 6.5% by weight of graphite, 0.5% by weight of pentaerythritol stearate, 0.2% by weight of carbon black, and 0.2% by weight of N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexanediamine, add the mixture to a conical mixer, and mix for 25 minutes before removing from the mixer for later use. S5: Provide three loss-in-weight scales, add the two mixed materials obtained in step S3 and step S4 to two of the loss-in-weight scales respectively, and weigh 40% by mass of magnesium hydroxide and add it to the third loss-in-weight scale; S6: providing a twin-screw extruder, wherein the discharge ports of the three loss-in-weight scales in step S5 are connected to the feed port of the twin-screw extruder, and the three loss-in-weight scales discharge materials in a ratio of 40%, 20%, and 40%; S7: The mixed material in step S5 and magnesium hydroxide are kneaded in a twin-screw extruder and then cut into uniform particles; S8: The uniform particles are screened through a vibrating screen to remove large particles and powder to obtain composite material particles of uniform size; the screened composite material of uniform size is fed into a homogenization bin through a vacuum feeder to further evenly mix the finished products at different time periods. The homogenization time is 2 hours.

[0023] In this example, nylon 6, a matrix resin with excellent mechanical properties and heat resistance, is added as a thermally conductive filler to significantly enhance the material's thermal conductivity. Graphite, with its layered structure and high thermal conductivity, forms an effective thermal network within the resin matrix. Multiple experiments have verified that a graphite addition of 6.5% by weight maintains the material's mechanical properties while providing excellent thermal conductivity.

[0024] The composition design of the reaction aid is also an important feature of this embodiment. The toughening agent maleic anhydride grafted polyolefin elastomer can improve the toughness of the material and reduce the increase in brittleness caused by the addition of fillers. The flame retardant magnesium hydroxide not only has a flame retardant effect, but also can be used as a filler to improve the thermal conductivity of the material. The lubricant pentaerythritol stearate can improve the processing fluidity of the material and make the components more evenly dispersed during the mixing process. In addition to providing a stable black color, the colorant carbon black can also enhance the ultraviolet stability of the material. The antioxidant combination of phosphorous acid solution and N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl] hexanediamine can effectively prevent the oxidative degradation of the material during high-temperature processing and use, thereby extending the service life of the material.

[0025] The pretreatment step in the preparation process is crucial. Drying nylon 6 at 85°C for 3 hours can effectively remove moisture from the material and prevent hydrolysis reactions that lead to molecular weight loss during subsequent high-temperature processing. The use of double-screw mixers and conical mixers can ensure that the components achieve a good dispersion effect in the premixing stage.

[0026] Three loss-in-weight scales, each discharging material at a ratio of 40%, 20%, and 40%, ensure that materials enter the twin-screw extruder at a stable rate and ratio, avoiding product quality fluctuations caused by uneven feeding. The twin-screw extruder provides sufficient shear force and mixing effect during the mixing process, ensuring that the components are fully dispersed and compatible.

[0027] The final vibrating screen and homogenization steps ensure uniform particle size and consistent performance across batches. A two-hour homogenization time has been proven to achieve optimal homogenization results.

[0028] Through the above-mentioned formula design and process control, the new modified thermally conductive material of this embodiment has excellent thermal conductivity, good mechanical properties, and flame retardant properties, and is suitable for application scenarios requiring heat dissipation, such as electronic appliances and automotive parts. The thermal conductivity of the material can reach 0.8-1.2 W / (m·K), which is much higher than the 0.2-0.3 W / (m·K) of ordinary nylon materials. At the same time, the material maintains good processing properties and can be formed by conventional plastic processing methods such as injection molding and extrusion.

[0029] Example 2 A new modified thermally conductive material comprises, by mass, 37.1% resin, 6.5% graphite, and 56.4% reaction aids. The resin is nylon 6 (polycaprolactam), and the reaction aids include a combination of at least two of the following: a toughening agent, a flame retardant, a colorant, a lubricant, and an antioxidant. The antioxidants include phosphorous acid solution and N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexanediamine. The toughening agent is a maleic anhydride-grafted polyolefin elastomer, the flame retardant is magnesium hydroxide, the colorant is carbon black, and the lubricant is pentaerythritol stearate.

[0030] The preparation process of the novel modified thermal conductive material comprises the following steps: S1: provides nylon 6; S2: Place nylon 6 in an oven and dry at 80°C for 2 hours; S3: providing 3% by weight of a toughening agent and 0.5% by weight of a phosphorous acid solution, and weighing 37.1% by weight of nylon 6 dried in step S2, the toughening agent and the phosphorous acid solution in step S3, and adding them together into a double-screw ribbon mixer, mixing for 10 minutes, and then removing them for later use; S4: Weigh 12.5% ​​by weight of magnesium hydroxide, 6.5% by weight of graphite, 0.5% by weight of pentaerythritol stearate, 0.2% by weight of carbon black, and 0.2% by weight of N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexanediamine, add the mixture to a conical mixer, and mix for 20 minutes before removing from the mixer for later use. S5: Provide three loss-in-weight scales, add the two mixed materials obtained in step S3 and step S4 to two of the loss-in-weight scales respectively, and weigh 40% by mass of magnesium hydroxide and add it to the third loss-in-weight scale; S6: providing a twin-screw extruder, wherein the discharge ports of the three loss-in-weight scales in step S5 are connected to the feed port of the twin-screw extruder, and the three loss-in-weight scales discharge materials in a ratio of 40%, 20%, and 40%; S7: The mixed material in step S5 and magnesium hydroxide are kneaded in a twin-screw extruder and then cut into uniform particles; S8: The uniform particles are screened through a vibrating screen to remove large particles and powder to obtain composite material particles of uniform size; the screened composite material of uniform size is fed into a homogenization bin through a vacuum feeder to further evenly mix the finished products at different time periods. The homogenization time is 1 hour.

[0031] In this example, the main difference from Example 1 lies in adjustments to the drying conditions, mixing time, and homogenization time. Nylon 6 was dried at 80°C for 2 hours, compared to the 85°C drying time of Example 1, which reduced both the drying temperature and time. This adjustment is suitable for nylon 6 raw materials with lower moisture content, saving energy and production time.

[0032] The mixing time of the twin-screw ribbon mixer was reduced from 12 minutes to 10 minutes, the mixing time of the conical mixer was reduced from 25 minutes to 20 minutes, and the homogenization time was reduced from 2 hours to 1 hour. These time parameter adjustments are intended to improve production efficiency. At the same time, through experimental verification, it is still possible to ensure the full mixing and uniform dispersion of the material components under these conditions.

[0033] By optimizing and adjusting the aforementioned process parameters, the novel modified thermally conductive material of this embodiment maintains excellent performance while improving production efficiency and reducing energy consumption, making it more suitable for large-scale production. The material's thermal conductivity is approximately 0.75-1.1 W / (m·K), slightly lower than that of Example 1 but still significantly higher than that of conventional nylon materials.

[0034] Example 3 A new modified thermally conductive material comprises, by mass, 37.1% resin, 6.5% graphite, and 56.4% reaction aids. The resin is nylon 6 (polycaprolactam), and the reaction aids include a combination of at least two of the following: a toughening agent, a flame retardant, a colorant, a lubricant, and an antioxidant. The antioxidants include phosphorous acid solution and N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexanediamine. The toughening agent is a maleic anhydride-grafted polyolefin elastomer. The flame retardant is magnesium hydroxide, the colorant is carbon black, and the lubricant is pentaerythritol stearate.

[0035] The preparation process of the novel modified thermal conductive material comprises the following steps: S1: provides nylon 6; S2: Place nylon 6 in an oven and dry at 90°C for 4 hours; S3: providing 3% by weight of a toughening agent and 0.5% by weight of a phosphorous acid solution, and weighing 37.1% by weight of nylon 6 dried in step S2, the toughening agent and the phosphorous acid solution in step S3, and adding them together into a double-screw ribbon mixer, mixing for 15 minutes, and then removing them for later use; S4: Weigh 12.5% ​​by weight of magnesium hydroxide, 6.5% by weight of graphite, 0.5% by weight of pentaerythritol stearate, 0.2% by weight of carbon black, and 0.2% by weight of N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexanediamine, add the mixture to a conical mixer, and mix for 30 minutes before removing from the mixer for later use. S5: Provide three loss-in-weight scales, add the two mixed materials obtained in step S3 and step S4 to two of the loss-in-weight scales respectively, and weigh 40% by mass of magnesium hydroxide and add it to the third loss-in-weight scale; S6: providing a twin-screw extruder, wherein the discharge ports of the three loss-in-weight scales in step S5 are connected to the feed port of the twin-screw extruder, and the three loss-in-weight scales discharge materials in a ratio of 40%, 20%, and 40%; S7: The mixed material in step S5 and magnesium hydroxide are kneaded in a twin-screw extruder and then cut into uniform particles; S8: The uniform particles are screened through a vibrating screen to remove large particles and powder to obtain composite material particles of uniform size; the screened composite material of uniform size is fed into a homogenization bin through a vacuum feeder to further evenly mix the finished products at different time periods. The homogenization time is 3 hours.

[0036] In this embodiment, compared with Examples 1 and 2, the main difference is that a higher drying temperature and a longer processing time are used. Nylon 6 is dried at 90°C for 4 hours. This condition is suitable for nylon 6 raw materials with a high moisture content and can more thoroughly remove moisture from the material, ensuring that the material performance will not be degraded due to residual moisture during subsequent processing.

[0037] The mixing time of the twin-ribbon mixer is extended to 15 minutes, the mixing time of the conical mixer is extended to 30 minutes, and the homogenization time is extended to 3 hours. These extensions are intended to ensure more thorough mixing and dispersion of the components, making them particularly suitable for applications with extremely high requirements for product quality.

[0038] By adjusting the aforementioned process parameters, the novel modified thermally conductive material of this embodiment exhibits greater uniformity and stability, more even dispersion of the components, and a more complete thermal network. The thermal conductivity of the material can reach 0.9-1.3 W / (m·K), higher than that of Examples 1 and 2. However, this results in relatively low production efficiency and higher energy consumption.

[0039] This material is particularly suitable for applications such as precision electronic equipment and high-end automotive parts, which require extremely high heat dissipation performance. In addition to its excellent thermal conductivity, the material also exhibits improved long-term stability and aging resistance.

[0040] It should be noted that Example 1, Example 2, and Example 3 are all a type of new modified thermal conductive material.

[0041] It is worth noting that in Example 3, it is necessary to ensure that the graphite filler is not excessive, as excessive filler will cause agglomeration.

[0042] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A new type of modified thermal conductive material, characterized in that: The composition comprises 37.1% resin, 6.5% graphite and 56.4% reaction aid in percentage by mass.

2. The novel modified thermal conductive material according to claim 1, characterized in that: The resin is nylon 6 (polycaprolactam).

3. The novel modified thermal conductive material according to claim 2, characterized in that: The reaction aid comprises a combination of at least two of a toughening agent, a flame retardant, a colorant, a lubricant, and an antioxidant.

4. The novel modified thermal conductive material according to claim 3, characterized in that: The antioxidant comprises two kinds of agents: phosphorous acid solution and N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexanediamine.

5. The novel modified thermal conductive material according to claim 4, characterized in that: The toughening agent is maleic anhydride grafted polyolefin elastomer, the flame retardant is magnesium hydroxide, the colorant is carbon black, and the lubricant is pentaerythritol stearate.

6. A process for preparing the novel modified thermally conductive material according to any one of claim 5, characterized in that: Including steps: S1: provides nylon 6; S2: Place nylon 6 in an oven and dry at 80-90°C for 2-4 hours; S3: providing 3% by weight of a toughening agent and 0.5% by weight of a phosphorous acid solution, and weighing 37.1% by weight of nylon 6 dried in step S2, the toughening agent and the phosphorous acid solution in step S3, and adding them together into a double-screw ribbon mixer, mixing for 10-15 minutes, and then removing them for later use; S4: Weigh 12.5% ​​by weight of magnesium hydroxide, 6.5% by weight of graphite, 0.5% by weight of pentaerythritol stearate, 0.2% by weight of carbon black, and 0.2% by weight of N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexanediamine, add the mixture to a conical mixer, mix for 20-30 minutes, and then remove from the mixer for later use; S5: Provide three loss-in-weight scales, add the two mixed materials obtained in step S3 and step S4 to two of the loss-in-weight scales respectively, and weigh 40% by mass of magnesium hydroxide and add it to the third loss-in-weight scale; S6: providing a twin-screw extruder, wherein the discharge ports of the three loss-in-weight scales in step S5 are connected to the feed port of the twin-screw extruder, and the three loss-in-weight scales discharge materials in a ratio of 40%, 20%, and 40%; S7: The mixed material in step S5 and magnesium hydroxide are kneaded in a twin-screw extruder and then cut into uniform particles.

7. The preparation process of the novel modified thermal conductive material according to claim 6, characterized in that: After step S7, the method further includes the following steps: The uniform particles are screened through a vibrating screen to remove large particles and powder to obtain composite material particles of uniform size; the screened composite material of uniform size enters the homogenization bin through a vacuum feeder to further evenly mix the finished products in different time periods, and the homogenization time is 1-3 hours.

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