Nanoparticle-filled silicone rubber and method of making same

Abstract

This invention discloses a nanoparticle-filled silicone rubber and its preparation method, relating to the field of polymer materials technology. The preparation method of the nanoparticle-filled silicone rubber of this invention includes the following steps: (1) adding 80-100 parts of raw silicone rubber, 10-25 parts of reinforcing filler, 1-3 parts of dimethyl hydroxy silicone oil, 3-10 parts of modified nano flame retardant, 0.05-2 parts of antioxidant, and 0.05-5 parts of lubricant to a mixing mill. Under nitrogen protection, the mixing temperature is 40-60℃, the rotation speed is 20-100 rpm, and the duration is 5-30 min to obtain a mixed mixture; (2) transferring the mixed mixture to an open mill, adding 2-5 parts of vulcanizing agent, mixing evenly, and then extruding and vulcanizing to obtain the product. The product prepared by this invention not only has good flame retardant properties but also excellent strength and toughness. The nanoparticle-filled silicone rubber of this invention can be widely used in high-grade wires and cables, aviation, aerospace, energy systems, electronics, automobiles, and other fields.

Description

Technical Field

[0001] This invention relates to a nanoparticle-filled silicone rubber and its preparation method, belonging to the field of polymer materials technology. Background Technology

[0002] Silicone rubber is a type of rubber whose main chain consists of alternating silicon and oxygen atoms, with two organic groups typically attached to each silicon atom. Ordinary silicone rubber is mainly composed of siloxane chains containing methyl groups and a small amount of vinyl groups. The introduction of phenyl groups improves the high and low temperature resistance of silicone rubber, while the introduction of trifluoropropyl and cyano groups improves its temperature and oil resistance. Silicone rubber has good low-temperature resistance, generally remaining functional at -55°C. With the introduction of phenyl groups, it can reach -73°C. Silicone rubber also exhibits outstanding heat resistance, capable of long-term operation at 180°C, and can withstand temperatures slightly above 200°C for weeks or longer while maintaining elasticity. It can also withstand instantaneous temperatures above 300°C. Silicone rubber has excellent air permeability, with the highest oxygen permeability among synthetic polymers.

[0003] Silicone rubber is mainly used in the wire and cable industry as an insulation material, insulating filler, and protective sheathing material. Silicone rubber possesses excellent high-temperature resistance, insulation properties, and anti-aging properties, maintaining good performance in harsh environments, thereby improving the transmission efficiency and safety of cables. The advantages of silicone rubber in wires and cables are mainly reflected in: 1. High-temperature resistance: Silicone rubber can work stably for a long time in high-temperature environments, with a service life of over 30 years at room temperature, meeting the requirements of cables operating in high-temperature environments. 2. Insulation properties: Silicone rubber has stable insulation properties and high reliability, able to withstand the effects of adverse environments such as high voltage, high temperature, humidity, and acids and alkalis. 3. Anti-aging properties: Silicone rubber has excellent oxidation resistance, UV resistance, and weather resistance, resulting in a long service life and reducing the possibility of cable aging and damage.

[0004] However, the flame-retardant properties of silicone rubber are limited when it burns, requiring the addition of flame retardants to the matrix to compensate for its poor flame retardancy. However, the large amount of common inorganic flame retardants added can severely affect the flexibility of silicone rubber. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a silicone rubber with good flame-retardant properties and a method for preparing the same.

[0006] A nanoparticle-filled silicone rubber is prepared from the following components in parts by weight:

[0007]

[0008] Lubricant 0.05-5 parts

[0009] The preferred raw silicone rubber is methyl vinyl silicone rubber.

[0010] The reinforcing agent is preferably silica, and the particle size is preferably greater than or equal to 2000 mesh.

[0011] The preferred vulcanizing agent is dicumyl peroxide.

[0012] Dimethyl hydroxy silicone oil can effectively control the structuring effect between raw silicone rubber, fillers, and nano flame retardants, improve the processing performance of silicone rubber, and enhance the mechanical properties of the product.

[0013] The modified nano flame retardant is a modified nano-layered silicate mineral.

[0014] The layered silicate mineral is preferably nano-mica powder with a mesh size of not less than 10,000 mesh.

[0015] The modified nano flame retardant is prepared by adding 1 part by weight of the nano flame retardant to 10-100 parts by weight of 2-ethylhexyl diphenyl phosphate, impregnating, filtering and drying.

[0016] The soaking time is 0.5-24h; the soaking stirring speed is 100-3000 rpm.

[0017] 2-Ethylhexyl diphenyl phosphate can slightly corrode nano-mica powder, causing it to tightly coat the surface of the nano-mica powder particles. The long-chain alkyl groups are arranged outwards, which improves the dispersion performance of the nano-mica powder and makes it less prone to agglomeration.

[0018] The lubricant is preferably at least one of silicone oil and silicone grease.

[0019] The antioxidants mentioned are selected from one or more of hindered phenols, thiolated compounds, hindered amines (HALS), and phosphites.

[0020] Furthermore, the antioxidant is one or more of antioxidant 1076, antioxidant 1098, antioxidant 1010, antioxidant 300 or antioxidant 168.

[0021] A method for preparing nanoparticle-filled silicone rubber includes the following steps:

[0022] (1) Add 80-100 parts of raw silicone rubber, 10-25 parts of reinforcing filler, 1-3 parts of dimethyl hydroxy silicone oil, 3-10 parts of modified nano flame retardant, 0.05-2 parts of antioxidant and 0.05-5 parts of lubricant to a mixer. Under nitrogen protection, the mixing temperature is 40-60℃, the speed is 20-100rpm, and the duration is 5-30min to obtain a mixed mixture.

[0023] (2) Transfer the mixture to a two-roll mill, add 2-5 parts of vulcanizing agent, mix evenly, and then extrude and vulcanize to obtain the product.

[0024] The open mill roll temperature is 50-65℃; the extruder temperature is 100-130℃ in zone one, 120-150℃ in zone two, 140-160℃ in zone three, 140-160℃ in zone four, and 150-160℃ in die head; the vulcanization temperature is 170-185℃, and the time is 10-60 minutes.

[0025] The beneficial effects of this invention are:

[0026] 1. In this invention, 2-ethylhexyl diphenyl phosphate can slightly corrode the nano-mica powder, causing it to tightly coat the inner and outer surfaces of the nano-mica powder particles, with the long-chain alkyl groups arranged outwards, thereby improving the dispersion performance of the nano-mica powder and making it less prone to agglomeration.

[0027] 2-Ethylhexyl diphenyl phosphate can synergistically work with nano-mica powder. During the combustion of silicone rubber, it forms a dense barrier layer at the combustion site, effectively preventing the transfer of heat and oxygen, thus significantly reducing the combustion rate and improving the material's flame-retardant properties. The released water vapor can cool the surrounding heat-generating area, controlling combustion.

[0028] 3. The nanoparticle-filled silicone rubber of this invention can be widely used in high-grade wires and cables, aviation, aerospace, energy, electronics, automobiles and other fields. Detailed Implementation

[0029] Unless otherwise specified, all raw materials used in this invention are commercially available or prepared according to conventional methods in the art. Unless otherwise defined or stated, all technical and scientific terms used herein have the same meaning as are familiar to those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to the methods of this invention. Other aspects of this invention will be apparent to those skilled in the art from the disclosure herein. The invention is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0030] Unless otherwise specified, experimental methods in the following examples are generally performed according to national standards. If no corresponding national standard exists, general international standards, standard conditions, or conditions recommended by the manufacturer are followed. Unless otherwise stated, all parts are parts by weight, and all percentages are weight percentages.

[0031] It should be noted that those skilled in the art can make various changes and improvements without departing from the concept of this invention. These all fall within the scope of protection of this invention.

[0032] In the following examples and comparative examples, all raw materials were commercially available. Some raw material specifications and sources are as follows:

[0033] The supplier of raw methyl vinyl silicone rubber is Dongguan Shuang'ao Plastics Co., Ltd.

[0034] The silica is 3000 mesh, and the supplier is Shandong Kasong New Materials Co., Ltd.

[0035] The vulcanizing agent is dicumyl peroxide, and the supplier is Wanqing Chemical Technology Co., Ltd.

[0036] The supplier of dimethyl hydroxy silicone oil is Jinan Xinglongda Chemical Co., Ltd.

[0037] Nano mica powder, 15000 mesh, 12500 mesh, and 10000 mesh, is supplied by Donghai County Fucai Mineral Products Co., Ltd.

[0038] 2-Ethylhexyl diphenyl phosphate is a transparent yellow liquid, supplied by Jiangsu Puleisi Biotechnology Co., Ltd.

[0039] Unless otherwise specified, the modified nano-mica powder in each embodiment and comparative example is prepared by adding 1 part by weight of nano-mica powder to 50 parts by weight of 2-ethylhexyl diphenyl phosphate for 2 hours, stirring at 200 rpm, and then filtering and drying.

[0040] Example 1:

[0041] (1) Add 80 parts of silicone rubber raw rubber, 10 parts of silica, 1 part of dimethyl hydroxy silicone oil, 4 parts of modified nano mica powder, 0.1 parts of antioxidant 1010 and 0.1 parts of lubricant silicone grease to a mixer. Under nitrogen protection, the mixing temperature is 42℃, the speed is 30rpm, and the duration is 8min to obtain a mixed mixture.

[0042] (2) Transfer the mixed mixture to a two-roll mill, add 2 parts of the vulcanizing agent dicumyl peroxide, mix evenly, and then extrude and vulcanize to obtain the product. The roller temperature of the two-roll mill is 55℃; the extruder temperature is 100℃ in zone 1, 120℃ in zone 2, 140℃ in zone 3, 140℃ in zone 4, and the die temperature is 150℃; the vulcanization temperature is 170℃ and the time is 15min.

[0043] In this embodiment, the nano-mica powder is 10,000 mesh.

[0044] Example 2:

[0045] (1) 100 parts of raw silicone rubber, 25 parts of silica, 3 parts of dimethyl hydroxyl silicone oil, 10 parts of modified nano mica powder, 1 part of antioxidant 1010, 1 part of antioxidant 168, and 3 parts of lubricant silicone grease were added to a mixer. Under nitrogen protection, the mixing temperature was 58℃, the speed was 80rpm, and the duration was 30min to obtain a mixed mixture.

[0046] (2) The mixture is transferred to a two-roll mill, 5 parts of the vulcanizing agent dicumyl peroxide are added, and after being mixed evenly, it is extruded and vulcanized to obtain the product. The roller temperature of the two-roll mill is 65°C; the extruder temperature is 110°C in zone 1, 140°C in zone 2, 150°C in zone 3, 150°C in zone 4, and the die temperature is 160°C; the vulcanization temperature is 170°C and the time is 55 min.

[0047] In this embodiment, the nano-mica powder is 10,000 mesh.

[0048] Example 3:

[0049] (1) Add 90 parts of raw silicone rubber, 20 parts of silica, 2 parts of dimethyl hydroxyl silicone oil, 8 parts of modified nano mica powder, 0.5 parts of antioxidant, and 1 part of lubricant silicone grease to a mixer. Under nitrogen protection, the mixing temperature is 50℃, the speed is 30rpm, and the duration is 50-30min to obtain a mixed mixture.

[0050] (2) The mixed mixture is transferred to a two-roll mill, 4 parts of the vulcanizing agent dicumyl peroxide are added, and after being mixed evenly, it is extruded and vulcanized to obtain the product. The roller temperature of the two-roll mill is 55°C; the extruder temperature is 120°C in zone 1, 140°C in zone 2, 150°C in zone 3, 150°C in zone 4, and the die temperature is 160°C; the vulcanization temperature is 175°C and the time is 20 minutes.

[0051] In this embodiment, the nano-mica powder is 15000 mesh.

[0052] Example 4:

[0053] (1) Add 90 parts of raw silicone rubber, 20 parts of silica, 2 parts of dimethyl hydroxyl silicone oil, 8 parts of modified nano mica powder, 0.5 parts of antioxidant, and 1 part of lubricant silicone grease to a mixer. Under nitrogen protection, the mixing temperature is 50℃, the speed is 30rpm, and the duration is 50-30min to obtain a mixed mixture.

[0054] (2) The mixed mixture is transferred to a two-roll mill, 4 parts of the vulcanizing agent dicumyl peroxide are added, and after being mixed evenly, it is extruded and vulcanized to obtain the product. The roller temperature of the two-roll mill is 55°C; the extruder temperature is 120°C in zone 1, 140°C in zone 2, 150°C in zone 3, 150°C in zone 4, and the die temperature is 160°C; the vulcanization temperature is 175°C and the time is 20 minutes.

[0055] In this embodiment, the nano-mica powder is 12500 mesh.

[0056] Example 5:

[0057] (1) Add 90 parts of raw silicone rubber, 20 parts of silica, 2 parts of dimethyl hydroxyl silicone oil, 8 parts of modified nano mica powder, 0.5 parts of antioxidant, and 1 part of lubricant silicone grease to a mixer. Under nitrogen protection, the mixing temperature is 50℃, the speed is 30rpm, and the duration is 50-30min to obtain a mixed mixture.

[0058] (2) The mixed mixture is transferred to a two-roll mill, 4 parts of the vulcanizing agent dicumyl peroxide are added, and after being mixed evenly, it is extruded and vulcanized to obtain the product. The roller temperature of the two-roll mill is 55°C; the extruder temperature is 120°C in zone 1, 140°C in zone 2, 150°C in zone 3, 150°C in zone 4, and the die temperature is 160°C; the vulcanization temperature is 175°C and the time is 20 minutes.

[0059] In this embodiment, the nano-mica powder is 10,000 mesh.

[0060] All comparative examples of this invention are compared with Example 4.

[0061] Comparative Example 1

[0062] (1) Add 92 parts of raw silicone rubber, 20 parts of silica, 8 parts of modified nano mica powder, 0.5 parts of antioxidant, and 1 part of lubricant silicone grease to a mixer. Under nitrogen protection, the mixing temperature is 50℃, the speed is 30rpm, and the duration is 50-30min to obtain a mixed mixture.

[0063] (2) The mixed mixture is transferred to a two-roll mill, 4 parts of the vulcanizing agent dicumyl peroxide are added, and after being mixed evenly, it is extruded and vulcanized to obtain the product. The roller temperature of the two-roll mill is 55°C; the extruder temperature is 120°C in zone 1, 140°C in zone 2, 150°C in zone 3, 150°C in zone 4, and the die temperature is 160°C; the vulcanization temperature is 175°C and the time is 20 minutes.

[0064] This comparative example does not include 2 parts of dimethyl hydroxy silicone oil, and the nano mica powder is 12500 mesh.

[0065] Comparative Example 2

[0066] (1) Add 90 parts of raw silicone rubber, 20 parts of silica, 2 parts of dimethyl hydroxyl silicone oil, 8 parts of nano mica powder, 0.5 parts of antioxidant, and 1 part of lubricant silicone grease to a mixer. Under nitrogen protection, the mixing temperature is 50℃, the speed is 30rpm, and the duration is 50-30min to obtain a mixed mixture.

[0067] (2) The mixed mixture is transferred to a two-roll mill, 4 parts of the vulcanizing agent dicumyl peroxide are added, and after being mixed evenly, it is extruded and vulcanized to obtain the product. The roller temperature of the two-roll mill is 55°C; the extruder temperature is 120°C in zone 1, 140°C in zone 2, 150°C in zone 3, 150°C in zone 4, and the die temperature is 160°C; the vulcanization temperature is 175°C and the time is 20 minutes.

[0068] In this comparative example, the nano-mica powder is 12500 mesh.

[0069] Comparative Example 3

[0070] (1) Add 90 parts of raw silicone rubber, 20 parts of silica, 2 parts of dimethyl hydroxyl silicone oil, 8 parts of 2-ethylhexyl diphenyl phosphate, 0.5 parts of antioxidant, and 1 part of lubricant silicone grease to a mixer. Under nitrogen protection, the mixing temperature is 50℃, the speed is 30rpm, and the duration is 50-30min to obtain a mixed mixture.

[0071] (2) The mixed mixture is transferred to a two-roll mill, 4 parts of the vulcanizing agent dicumyl peroxide are added, and after being mixed evenly, it is extruded and vulcanized to obtain the product. The roller temperature of the two-roll mill is 55°C; the extruder temperature is 120°C in zone 1, 140°C in zone 2, 150°C in zone 3, 150°C in zone 4, and the die temperature is 160°C; the vulcanization temperature is 175°C and the time is 20 minutes.

[0072] Comparative Example 4

[0073] (1) Add 90 parts of raw silicone rubber, 20 parts of silica, 2 parts of dimethyl hydroxyl silicone oil, 6 parts of nano mica powder, 2 parts of 2-ethylhexyl diphenyl phosphate, 0.5 parts of antioxidant, and 1 part of lubricant silicone grease to a mixer. Under nitrogen protection, the mixing temperature is 50℃, the speed is 30rpm, and the duration is 50-30min to obtain a mixed mixture.

[0074] (2) The mixed mixture is transferred to a two-roll mill, 4 parts of the vulcanizing agent dicumyl peroxide are added, and after being mixed evenly, it is extruded and vulcanized to obtain the product. The roller temperature of the two-roll mill is 55°C; the extruder temperature is 120°C in zone 1, 140°C in zone 2, 150°C in zone 3, 150°C in zone 4, and the die temperature is 160°C; the vulcanization temperature is 175°C and the time is 20 minutes.

[0075] In this embodiment, the nano-mica powder is 12500 mesh.

[0076] Comparative Example 5

[0077] Preparation method of modified nano-mica powder: 1 part by weight of nano-mica powder is added to 50 parts by weight of coupling agent KH550 for 2 hours, stirred at 200 rpm, filtered and dried to obtain the powder.

[0078] (1) Add 90 parts of raw silicone rubber, 20 parts of silica, 2 parts of dimethyl hydroxyl silicone oil, 8 parts of modified nano mica powder, 0.5 parts of antioxidant, and 1 part of lubricant silicone grease to a mixer. Under nitrogen protection, the mixing temperature is 50℃, the speed is 30rpm, and the duration is 50-30min to obtain a mixed mixture.

[0079] (2) The mixed mixture is transferred to a two-roll mill, 4 parts of the vulcanizing agent dicumyl peroxide are added, and after being mixed evenly, it is extruded and vulcanized to obtain the product. The roller temperature of the two-roll mill is 55°C; the extruder temperature is 120°C in zone 1, 140°C in zone 2, 150°C in zone 3, 150°C in zone 4, and the die temperature is 160°C; the vulcanization temperature is 175°C and the time is 20 minutes.

[0080] In this embodiment, the nano-mica powder is 12500 mesh.

[0081] Comparative Example 6

[0082] Preparation method of modified nano-mica powder: 1 part by weight of nano-mica powder is added to 50 parts by weight of dispersant ammonium dodecyl sulfate for 2 hours, stirring at 200 rpm, and then filtered and dried to obtain the powder.

[0083] (1) Add 90 parts of raw silicone rubber, 20 parts of silica, 2 parts of dimethyl hydroxyl silicone oil, 8 parts of modified nano mica powder, 0.5 parts of antioxidant, and 1 part of lubricant silicone grease to a mixer. Under nitrogen protection, the mixing temperature is 50℃, the speed is 30rpm, and the duration is 50-30min to obtain a mixed mixture.

[0084] (2) The mixed mixture is transferred to a two-roll mill, 4 parts of the vulcanizing agent dicumyl peroxide are added, and after being mixed evenly, it is extruded and vulcanized to obtain the product. The roller temperature of the two-roll mill is 55°C; the extruder temperature is 120°C in zone 1, 140°C in zone 2, 150°C in zone 3, 150°C in zone 4, and the die temperature is 160°C; the vulcanization temperature is 175°C and the time is 20 minutes.

[0085] In this embodiment, the nano-mica powder is 12500 mesh.

[0086] The performance parameter test methods and standards for each embodiment and comparative example are as follows:

[0087] Mechanical properties: Tensile strength was tested according to standard ISO 527-2 at a tensile speed of 50 mm / min.

[0088] Flame retardant performance: Referring to standard UL94, vertical burning test, thickness 1.6 mm. The results are shown in Table 1 below:

[0089] Table 1 Performance data for each embodiment

[0090]

[0091]

[0092] As can be seen from the table above, the product prepared by this invention not only has good flame retardant properties, but also excellent strength and toughness. The nanoparticle-filled silicone rubber of this invention can be widely used in high-grade wires and cables, aerospace, energy systems, electronics, automobiles, and other fields.

[0093] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A nanoparticle-filled silicone rubber, characterized in that, It is prepared from the following components in parts by weight:

2. The nanoparticle-filled silicone rubber as described in claim 1, characterized in that, The raw silicone rubber mentioned is methyl vinyl silicone rubber.

3. The nanoparticle-filled silicone rubber as described in claim 1, characterized in that, The reinforcing agent is silica with a particle size of not less than 2000 mesh; the vulcanizing agent is dicumyl peroxide.

4. The nanoparticle-filled silicone rubber as described in claim 1, characterized in that, The modified nano flame retardant is a modified nano-layered silicate mineral; the layered silicate mineral is nano mica powder with a particle size of not less than 10,000 mesh.

5. The nanoparticle-filled silicone rubber as described in claim 1, characterized in that, The modified nano flame retardant is prepared by adding 1 part by weight of the nano flame retardant to 10-100 parts by weight of 2-ethylhexyl diphenyl phosphate, impregnating, filtering and drying; the impregnation time is 0.5-24h; the impregnation stirring speed is 100-3000 rpm.

6. The nanoparticle-filled silicone rubber as described in claim 1, characterized in that, The lubricant is preferably at least one of silicone oil and silicone grease.

7. The nanoparticle-filled silicone rubber as described in claim 1, characterized in that, The antioxidants mentioned are selected from one or more of hindered phenols, thiolated compounds, hindered amines (HALS), and phosphites.

8. The nanoparticle-filled silicone rubber as described in claim 1, characterized in that, The antioxidant is one or more of antioxidant 1076, antioxidant 1098, antioxidant 1010, antioxidant 300 or antioxidant 168.

9. A method for preparing nanoparticle-filled silicone rubber, comprising the following steps: (1) Add 80-100 parts of raw silicone rubber, 10-25 parts of reinforcing filler, 1-3 parts of dimethyl hydroxy silicone oil, 3-10 parts of modified nano flame retardant, 0.05-2 parts of antioxidant and 0.05-5 parts of lubricant to a mixer. Under nitrogen protection, the mixing temperature is 40-60℃, the speed is 20-100rpm, and the duration is 5-30min to obtain a mixed mixture. (2) Transfer the mixture to a two-roll mill, add 2-5 parts of vulcanizing agent, mix evenly, and then extrude and vulcanize to obtain the product.

10. The method for preparing nanoparticle-filled silicone rubber as described in claim 9, characterized in that, The open mill roll temperature is 50-65℃; the extruder temperature is 100-130℃ in zone one, 120-150℃ in zone two, 140-160℃ in zone three, 140-160℃ in zone four, and 150-160℃ in die head; the vulcanization temperature is 170-185℃, and the time is 10-60 minutes.

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