Ceramic silicone rubber as well as preparation method and application thereof

Abstract

The invention provides ceramic silicone rubber as well as a preparation method and application thereof, and belongs to the technical field of functional materials. The ceramic silicone rubber provided by the invention is prepared from the following preparation raw materials in parts by mass: 90-105 parts of methyl vinyl silicone rubber; 35 to 45 parts of fumed silica; 3-10 parts of hydroxyl silicone oil; 0.1 to 8 parts of a silane coupling agent; 1-75 parts of an inorganic filler; the inorganic filler is mica powder, montmorillonite and wollastonite; 10-30 parts of low-melting-point glass powder, the melting point of the low-melting-point glass powder is 400-600 DEG C, and the low-melting-point glass powder is borate glass powder and / or phosphate glass powder; 0.1 to 0.3 part of platinum flame retardant; 0.5 to 1.5 parts of a vulcanizing agent; and 0.1-0.5 part of an internal release agent. The ceramic silicone rubber provided by the invention can maintain higher tensile strength and elongation at break on the basis of ensuring better ceramic performance.

Description

Technical Field

[0001] The present invention relates to the technical field of functional materials, and in particular to ceramic silicone rubber and a preparation method and application thereof. Background Art

[0002] Ceramic silicone rubber is usually made of silicone rubber, ceramic filler and flux. It has excellent insulation performance, aging resistance, arc resistance, ablation resistance and high and low temperature resistance. After being burned, it can quickly vitrify to form a ceramic shell, which plays a good role in fire prevention and heat insulation. It is widely used in the wire and cable industry, especially in places where high flame retardancy and fire resistance are required. In places where cables are densely laid, fires are very likely to occur, so these cable laying occasions have put forward higher requirements on the flame retardancy and fire resistance of cables. At the same time, in order to adapt to different usage scenarios and installation conditions, ceramic silicone rubber is usually required to have excellent mechanical properties. However, ceramic silicone rubber in the prior art often cannot take into account both excellent mechanical properties and vitrification properties, such as insufficient tensile strength and elongation at break, or the ceramic shell is prone to cracking. Summary of the invention

[0003] The object of the present invention is to provide a ceramic silicone rubber and a preparation method and application thereof. The ceramic silicone rubber provided by the present invention can maintain high tensile strength and elongation at break while ensuring good porcelain performance.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The present invention provides a ceramic silicone rubber, which is prepared from the following raw materials in parts by weight:

[0006] 90-105 parts of methyl vinyl silicone rubber;

[0007] 35-45 parts of fumed silica;

[0008] 3-10 parts of hydroxy silicone oil;

[0009] Silane coupling agent 0.1-8 parts;

[0010] 1 to 75 parts of inorganic filler; the inorganic filler is mica powder, montmorillonite and wollastonite;

[0011] 10 to 30 parts of low-melting-point glass powder, wherein the melting point of the low-melting-point glass powder is 400 to 600° C., and the low-melting-point glass powder is borate glass powder and / or phosphate glass powder;

[0012] 0.1 to 0.3 parts of a platinum flame retardant, wherein the mass content of platinum in the platinum flame retardant is 1000 to 3000 ppm;

[0013] Vulcanizing agent 0.5-1.5 parts.

[0014] Preferably, the mass ratio of the mica powder, montmorillonite and wollastonite is 15-25:15-25:15-25.

[0015] Preferably, the molar content of vinyl in the methyl vinyl silicone rubber is 0.01-0.3%; and the number average molecular weight of the methyl vinyl silicone rubber is 600,000-700,000.

[0016] Preferably, the particle size of the fumed silica is 10 to 50 nm, and the specific surface area is 200 to 300 m2 / g.

[0017] Preferably, the silane coupling agent includes one or more of vinyltrimethoxysilane, vinyltriethoxysilane and butadienyltriethoxysilane.

[0018] Preferably, the vulcanizing agent is an organic peroxide.

[0019] Preferably, the internal mold release agent is zinc stearate and stearic acid, and the mass ratio of zinc stearate to stearic acid is 2 to 2.5:1.

[0020] The present invention provides a method for preparing the ceramic silicone rubber described in the above technical solution, comprising the following steps:

[0021] Mixing methyl vinyl silicone rubber, fumed silica, hydroxy silicone oil, silane coupling agent, inorganic filler, low melting point glass powder, platinum flame retardant, vulcanizing agent and internal release agent to obtain a mixed material;

[0022] The mixed material is vulcanized to obtain the ceramic silicone rubber.

[0023] Preferably, the mixing comprises: first mixing methyl vinyl silicone rubber, hydroxy silicone oil, fumed silica and an internal release agent to obtain a first mixed material; second mixing the first mixed material, a silane coupling agent, an inorganic filler, a low melting point glass powder and a platinum flame retardant to obtain a second mixed material; third mixing the second mixed material and a vulcanizing agent;

[0024] The vulcanization includes sequentially performing a first vulcanization and a second vulcanization; the temperature of the first vulcanization is 100-120° C., and the time is 60-90 minutes; the temperature of the second vulcanization is 180-220° C., and the time is 90-120 minutes.

[0025] The present invention provides the use of the ceramic silicone rubber described in the above technical solution or the ceramic silicone rubber prepared by the preparation method described in the above technical solution in wires and cables or new energy vehicles.

[0026] The invention provides a ceramic silicone rubber, which is prepared from the following raw materials in parts by mass: 90-105 parts of methyl vinyl silicone rubber; 35-45 parts of fumed silica; 3-10 parts of hydroxy silicone oil; 0.1-8 parts of silane coupling agent; 1-75 parts of inorganic filler, wherein the inorganic filler is mica powder, montmorillonite and wollastonite; 10-30 parts of low-melting glass powder, wherein the melting point of the low-melting glass powder is 400-600°C, and the low-melting glass powder is borate glass powder and / or phosphate glass powder; 0.1-0.3 parts of platinum flame retardant, wherein the mass content of platinum in the platinum flame retardant is 1000-3000ppm; 0.5-1.5 parts of vulcanizer; and 0.1-0.5 parts of internal mold release agent. The present invention adopts methyl vinyl silicone rubber as a matrix material, and simultaneously compoundly uses fumed silica, hydroxy silicone oil, silane coupling agent, platinum flame retardant, vulcanizing agent, specific types of inorganic fillers and low-melting point glass powder to prepare ceramic silicone rubber. The ceramic silicone rubber can maintain high tensile strength and elongation at break while ensuring good porcelain performance. DETAILED DESCRIPTION

[0027] The present invention provides a ceramic silicone rubber, which is prepared from the following raw materials in parts by weight:

[0028] 90-105 parts of methyl vinyl silicone rubber;

[0029] 35-45 parts of fumed silica;

[0030] 3-10 parts of hydroxy silicone oil;

[0031] Silane coupling agent 0.1-5 parts;

[0032] 1 to 50 parts of inorganic filler; the inorganic filler is mica powder, montmorillonite and wollastonite;

[0033] 10 to 30 parts of low-melting-point glass powder, wherein the melting point of the low-melting-point glass powder is 400 to 600° C., and the low-melting-point glass powder is borate glass powder and / or phosphate glass powder;

[0034] 0.1 to 0.3 parts of a platinum flame retardant, wherein the mass content of platinum in the platinum flame retardant is 1000 to 3000 ppm;

[0035] 0.5-1.5 parts of vulcanizing agent;

[0036] Internal release agent 0.1 to 0.5 parts.

[0037] In the present invention, unless otherwise specified, the raw materials used are commercially available products well known to those skilled in the art.

[0038] In terms of mass fraction, the raw materials for preparing the ceramic silicone rubber of the present invention include 90 to 105 parts of methyl vinyl silicone rubber, specifically 90 parts, 93 parts, 95 parts, 98 parts, 100 parts, 102 parts or 105 parts. As an embodiment of the present invention, the vinyl molar content of the methyl vinyl silicone rubber can be 0.01 to 0.3%, specifically 0.01%, 0.03%, 0.05%, 0.08%, 0.1%, 0.2% or 0.3%; the number average molecular weight of the methyl vinyl silicone rubber can be 600,000 to 700,000, specifically 600,000, 630,000, 650,000, 670,000 or 700,000. The present invention uses methyl vinyl silicone rubber as a matrix material, and at the same time uses fumed silica, hydroxy silicone oil, silane coupling agent, platinum flame retardant, vulcanizing agent, and specific types of inorganic fillers and low-melting glass powder to prepare ceramic silicone rubber, which can be converted into inorganic ceramic materials under high temperature conditions to form a hard protective layer, which is conducive to isolating flames and heat.

[0039] Based on the mass fraction of the ceramic silicone rubber, the raw materials for preparing the ceramic silicone rubber of the present invention include 35 to 45 parts of fumed silica, specifically 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, 36 parts, 37 parts, 38 parts, 39 parts, 40 parts, 41 parts, 42 parts, 43 parts, 44 parts or 45 parts. As an embodiment of the present invention, the particle size of the fumed silica can be 10 to 50 nm, specifically 10 nm, 20 nm, 30 nm, 40 nm or 50 nm; the specific surface area is 200 to 300 m 2 / g, specifically 200m 2 / g, 250m 2 / g or 300m 2 In the embodiment of the present invention, the fumed silica with the above particle size and specific surface area can fill the gaps in the methyl vinyl silicone rubber to form a more compact structure, which is beneficial to improving the strength, wear resistance and weather resistance of the product.

[0040] Based on the mass fraction of the ceramic silicone rubber, the raw materials for preparing the ceramic silicone rubber of the present invention include 3 to 10 parts of hydroxy silicone oil, specifically 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts or 10 parts. The present invention adopts the above-mentioned amount of hydroxy silicone oil to improve the processing performance and physical properties of methyl vinyl silicone rubber, facilitate the uniform dispersion of fumed silica in methyl vinyl silicone rubber, prevent the structuring of methyl vinyl silicone rubber, and reduce permanent deformation.

[0041] Based on the mass fraction of the ceramic silicone rubber, the raw materials for preparing the ceramic silicone rubber of the present invention include 0.1 to 8 parts of silane coupling agent, specifically 0.1 parts, 1 parts, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts or 8 parts. As an embodiment of the present invention, the silane coupling agent includes one or more of vinyltrimethoxysilane, vinyltriethoxysilane and butadienyltriethoxysilane, specifically vinyltrimethoxysilane. The present invention uses the above-mentioned amount of silane coupling agent to enhance the physical properties and aging resistance of the product, such as enhancing the toughness, strength and ductility of the product, improving the aging resistance of the product under high temperature and ultraviolet rays, and extending the service life.

[0042] Based on the mass fraction of the ceramic silicone rubber, the raw materials for preparing the ceramic silicone rubber of the present invention include 1 to 75 parts of inorganic filler, and can further be 40 to 75 parts, specifically 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts or 75 parts; the inorganic filler is mica powder, montmorillonite and wollastonite, and the mass ratio of the mica powder, montmorillonite and wollastonite can be 15 to 25:15 to 25:15 to 25, specifically 1:1:1; the particle size of the inorganic filler can be 8 to 12 μm, specifically 10 μm. In the present invention, mica powder, montmorillonite and wollastonite are compounded as inorganic fillers, which can form a hard ceramic protective layer under high temperature conditions, prevent the methyl vinyl silicone rubber from further decomposing, and help improve the thermal stability and fire resistance of the product.

[0043] Based on the mass fraction of the ceramic silicone rubber, the raw materials for preparing the ceramic silicone rubber of the present invention include 10 to 30 parts of low-melting glass powder, specifically 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 20 parts, 25 parts or 30 parts; the melting point of the low-melting glass powder is 400 to 600°C, specifically 450°C; the low-melting glass powder is borate glass powder and / or phosphate glass powder, specifically phosphate glass powder. Compared with the use of silicate glass powder, the present invention uses the above-mentioned type of low-melting glass powder, which can form a dense and hard ceramic body structure under high temperature conditions, resist a high temperature of at least 1000°C, and has a good flame retardant effect, which is beneficial to prevent further combustion and oxidation of the material, thereby playing a flame retardant role.

[0044] Based on the mass fraction of the ceramic silicone rubber, the raw materials for preparing the ceramic silicone rubber of the present invention include 0.1 to 0.3 parts of platinum flame retardant, specifically 0.1 parts, 0.2 parts or 0.3 parts; the mass content of platinum in the platinum flame retardant is 1000 to 3000ppm, specifically 1000ppm, 1500ppm, 2000ppm, 2500ppm or 3000ppm. In the embodiment of the present invention, the use of the platinum flame retardant with the above dosage and platinum content can improve the flame retardant performance and thermal stability of the product, is conducive to catalytic carbonization, protects the unburned part and reduces the cracking and oxidation reaction of the product under high temperature conditions.

[0045] Based on the mass fraction of the ceramic silicone rubber, the raw materials for preparing the ceramic silicone rubber of the present invention include 0.5 to 1.5 parts of a vulcanizing agent, specifically 0.5 parts, 1 part or 1.5 parts. As an embodiment of the present invention, the vulcanizing agent may be an organic peroxide, and the organic peroxide may be 2,4-dichlorobenzoyl peroxide. The vulcanizing agent of the above amount and type used in the embodiment of the present invention can decompose under high temperature conditions to produce free radicals, which form crosslinks with the organic side groups of the methyl vinyl silicone rubber to obtain the properties of silicone; it is beneficial to make the product have the characteristics of high strength, no bubble generation, good transparency and stable physical properties after secondary vulcanization.

[0046] Based on the mass fraction of the ceramic silicone rubber, the raw materials for preparing the ceramic silicone rubber of the present invention include 0.1 to 0.5 parts of an internal release agent, specifically 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts or 0.5 parts. As an embodiment of the present invention, the internal release agent can be zinc stearate and stearic acid, and the mass ratio of zinc stearate to stearic acid can be 2 to 2.5:1, specifically 2:1. The use of the above-mentioned amount and type of internal release agent in the embodiment of the present invention can reduce the degree of adhesion of methyl vinyl silicone rubber in the mold, which is conducive to easier removal of the product from the mold.

[0047] The present invention provides a method for preparing the ceramic silicone rubber described in the above technical solution, comprising the following steps:

[0048] Mixing methyl vinyl silicone rubber, fumed silica, hydroxy silicone oil, silane coupling agent, inorganic filler, low melting point glass powder, platinum flame retardant, vulcanizing agent and internal release agent to obtain a mixed material;

[0049] The mixed material is vulcanized to obtain the ceramic silicone rubber.

[0050] The present invention mixes methyl vinyl silicone rubber, fumed silica, hydroxy silicone oil, silane coupling agent, inorganic filler, low melting point glass powder, platinum flame retardant, vulcanizing agent and internal mold release agent to obtain a mixed material. As an embodiment of the present invention, the mixing may include: mixing methyl vinyl silicone rubber, hydroxy silicone oil, fumed silica and internal mold release agent for a first time to obtain a first mixed material; mixing the first mixed material, silane coupling agent, inorganic filler, low melting point glass powder and platinum flame retardant for a second time to obtain a second mixed material; mixing the second mixed material with the vulcanizing agent for a third time to obtain a mixed material (referred to as the third mixed material).

[0051] As an embodiment of the present invention, the methyl vinyl silicone rubber can be kneaded first, and then the kneaded material is mixed with hydroxy silicone oil, fumed silica and an internal release agent for a first time; the kneading temperature can be 130-150°C, specifically 130°C, 135°C, 140°C, 145°C or 150°C; the time can be 1-3h, specifically 1h, 2h or 3h; the first mixing temperature can be 130-150°C, specifically 130°C, 135°C, 140°C, 145°C or 150°C; the time can be 2-3h; the kneading and first mixing can be carried out in a kneader.

[0052] As an embodiment of the present invention, the temperature of the second mixing can be 150-170°C, specifically 150°C, 155°C, 160°C, 165°C or 170°C; the time can be 0.5-2h, specifically 0.5h, 1h or 2h; the second mixing can be specifically carried out in a kneader.

[0053] As an embodiment of the present invention, vacuum treatment is also included between the second mixing and the third mixing; the temperature of the vacuum treatment can be 150-160°C, specifically 150°C, 155°C or 160°C; the time can be 1-1.5h; the vacuum degree can be -0.05-0.08MPa, specifically -0.05MPa, -0.06MPa, -0.07MPa or -0.08MPa; the role of the vacuum treatment is to remove small molecules in the raw rubber, moisture in the fumed silica and low-boiling point by-products generated during the mixing process, so as to ensure that the performance of the mixed rubber is more stable.

[0054] As an embodiment of the present invention, the temperature of the third mixing can be 20-40°C, specifically 20°C, 30°C or 40°C; the time can be 15-20 minutes; and the third mixing can be specifically carried out in an open mixing mill.

[0055] After obtaining the mixed material, the present invention vulcanizes the mixed material to obtain the ceramic silicone rubber. As an embodiment of the present invention, the vulcanization may include sequentially performing the first vulcanization and the second vulcanization; in the embodiment of the present invention, two vulcanizations are used to further crosslink and eliminate low molecular weight compounds. As an embodiment of the present invention, the temperature of the first vulcanization may be 100-120°C, specifically 100°C, 110°C or 120°C; the time may be 60-90min, specifically 60min, 70min, 80min or 90min; the first vulcanization may be specifically performed on a flat vulcanizer. As an embodiment of the present invention, the temperature of the second vulcanization may be 180-220°C, specifically 180°C, 190°C, 200°C, 210°C or 220°C; the time may be 90-120min, specifically 90min, 100min, 110min or 120min; the second vulcanization may be specifically performed in an oven.

[0056] The ceramic silicone rubber provided by the present invention can be sintered into a hard ceramic shell after being burned by an open flame. The shell of the ceramic shell is hard and can withstand vibrations of a certain intensity. It will not crack or fall off after being rained on. Moreover, the ceramic silicone rubber of the present invention has good electrical properties. In addition, the preparation process of the ceramic silicone rubber of the present invention is simple and the production cost is low.

[0057] The present invention provides the application of the ceramic silicone rubber described in the above technical solution or the ceramic silicone rubber prepared by the preparation method described in the above technical solution in wires and cables or new energy vehicles. The present invention does not specifically limit the specific application method of the ceramic silicone rubber, and a method familiar to those skilled in the art can be used.

[0058] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0059] Example 1

[0060] In parts by weight, the raw materials for preparing the ceramic silicone rubber in this embodiment are as follows:

[0061] 100 parts of methyl vinyl silicone rubber, 30 parts of fumed silica, 10 parts of low melting point glass powder, 60 parts of inorganic filler, 6 parts of hydroxy silicone oil, 6 parts of silane coupling agent, 0.1 parts of platinum flame retardant, 0.3 parts of internal release agent, and 0.5 parts of vulcanizing agent;

[0062] The vinyl molar content of the methyl vinyl silicone rubber is 0.05%, and the number average molecular weight is 650,000; the particle size of the fumed silica is 10 nm and the specific surface area is 200 m 2 / g; the low-melting-point glass powder is phosphate glass powder with a melting point of 450°C; the inorganic filler is a mixture of montmorillonite, wollastonite and mica powder in a mass ratio of 1:1:1; the silane coupling agent is vinyltrimethoxysilane; the platinum content of the platinum flame retardant is 1500ppm; the internal release agent is a mixture of zinc stearate and stearic acid in a mass ratio of 2:1; the vulcanizing agent is 2,4-dichlorobenzoyl peroxide.

[0063] The preparation method of the ceramic silicone rubber described in this embodiment is as follows:

[0064] (1) adding methyl vinyl silicone rubber into a kneader, kneading at 60° C. for 5 min, then adding hydroxy silicone oil, silane coupling agent and internal release agent, and kneading at 130° C. for 2 h to obtain a first mixed material;

[0065] (2) adding a silane coupling agent, an inorganic filler, a low melting point glass powder and a platinum flame retardant to the first mixed material, and mixing the mixture at 150° C. for 1 h to obtain a second mixed material;

[0066] (3) subjecting the second mixed material to vacuum treatment at a vacuum degree of -0.06 MPa and a temperature of 160° C. for 1 h, cooling the obtained rubber material and placing it in an open mixer, then adding a vulcanizing agent, and mixing at 30° C. for 15 min to obtain a third mixed material;

[0067] (4) After the third mixed material is pressed into a sheet, it is placed on a flat vulcanizer and heated and vulcanized at 110° C. for 1 hour, and then placed in an oven and subjected to secondary vulcanization at 200° C. for 1.5 hours to obtain the ceramic silicone rubber.

[0068] Example 2

[0069] In parts by weight, the raw materials for preparing the ceramic silicone rubber in this embodiment are as follows:

[0070] 100 parts of methyl vinyl silicone rubber, 35 parts of fumed silica, 10 parts of low melting point glass powder, 45 parts of inorganic filler, 8 parts of hydroxy silicone oil, 4 parts of silane coupling agent, 0.2 parts of platinum flame retardant, 0.3 parts of internal release agent, 1 part of vulcanizing agent;

[0071] The vinyl molar content of the methyl vinyl silicone rubber is 0.08%, and the number average molecular weight is 650,000; the particle size of the fumed silica is 10 nm and the specific surface area is 200 m 2 / g; the low-melting-point glass powder is phosphate glass powder with a melting point of 450°C; the inorganic filler is a mixture of montmorillonite, wollastonite and mica powder in a mass ratio of 1:1:1; the silane coupling agent is vinyltrimethoxysilane; the platinum content of the platinum flame retardant is 1500ppm; the internal release agent is a mixture of zinc stearate and stearic acid in a mass ratio of 2:1; the vulcanizing agent is 2,4-dichlorobenzoyl peroxide.

[0072] The preparation method of the ceramic silicone rubber in this embodiment is carried out by referring to the operation in Embodiment 1.

[0073] Example 3

[0074] In parts by weight, the raw materials for preparing the ceramic silicone rubber in this embodiment are as follows:

[0075] 100 parts of methyl vinyl silicone rubber, 25 parts of fumed silica, 10 parts of low melting point glass powder, 75 parts of inorganic filler, 5 parts of hydroxy silicone oil, 8 parts of silane coupling agent, 0.2 parts of platinum flame retardant, 0.3 parts of internal release agent, 1 part of vulcanizing agent;

[0076] The vinyl molar content of the methyl vinyl silicone rubber is 0.05%, and the number average molecular weight is 650,000; the particle size of the fumed silica is 10 nm and the specific surface area is 200 m 2 / g; the low-melting-point glass powder is phosphate glass powder with a melting point of 450°C; the inorganic filler is a mixture of montmorillonite, wollastonite and mica powder in a mass ratio of 1:1:1; the silane coupling agent is vinyltrimethoxysilane; the platinum content of the platinum flame retardant is 2000ppm; the internal release agent is a mixture of zinc stearate and stearic acid in a mass ratio of 2:1; the vulcanizing agent is 2,4-dichlorobenzoyl peroxide.

[0077] The preparation method of the ceramic silicone rubber in this embodiment is carried out by referring to the operation in Embodiment 1.

[0078] Example 4

[0079] In parts by weight, the raw materials for preparing the ceramic silicone rubber in this embodiment are as follows:

[0080] 100 parts of methyl vinyl silicone rubber, 30 parts of fumed silica, 10 parts of low melting point glass powder, 75 parts of inorganic filler, 6 parts of hydroxy silicone oil, 8 parts of silane coupling agent, 0.2 parts of platinum flame retardant, 0.3 parts of internal release agent, 1 part of vulcanizing agent;

[0081] The vinyl molar content of the methyl vinyl silicone rubber is 0.08%, and the number average molecular weight is 650,000; the particle size of the fumed silica is 10 nm and the specific surface area is 200 m 2 / g; the low-melting-point glass powder is phosphate glass powder with a melting point of 450°C; the inorganic filler is a mixture of montmorillonite, wollastonite and mica powder in a mass ratio of 1:1:1; the silane coupling agent is vinyltrimethoxysilane; the platinum content of the platinum flame retardant is 2500ppm; the internal release agent is a mixture of zinc stearate and stearic acid in a mass ratio of 2:1; the vulcanizing agent is 2,4-dichlorobenzoyl peroxide.

[0082] The preparation method of the ceramic silicone rubber in this embodiment is carried out by referring to the operation in Embodiment 1.

[0083] Example 5

[0084] In parts by weight, the raw materials for preparing the ceramic silicone rubber in this embodiment are as follows:

[0085] 100 parts of methyl vinyl silicone rubber, 35 parts of fumed silica, 10 parts of low melting point glass powder, 60 parts of inorganic filler, 7 parts of hydroxy silicone oil, 6 parts of silane coupling agent, 0.2 parts of platinum flame retardant, 0.3 parts of internal release agent, 1 part of vulcanizing agent;

[0086] The vinyl molar content of the methyl vinyl silicone rubber is 0.05%, and the number average molecular weight is 650,000; the particle size of the fumed silica is 10 nm and the specific surface area is 200 m 2 / g; the low-melting-point glass powder is phosphate glass powder with a melting point of 450°C; the inorganic filler is a mixture of montmorillonite, wollastonite and mica powder in a mass ratio of 1:1:1; the silane coupling agent is vinyltrimethoxysilane; the platinum content of the platinum flame retardant is 3000ppm; the internal release agent is a mixture of zinc stearate and stearic acid in a mass ratio of 2:1; the vulcanizing agent is 2,4-dichlorobenzoyl peroxide.

[0087] The preparation method of the ceramic silicone rubber in this embodiment is carried out by referring to the operation in Embodiment 1.

[0088] Comparative Example 1

[0089] The method of Example 5 is referred to, except that the low melting point glass powder is omitted.

[0090] Comparative Example 2

[0091] The method of Example 5 was followed, except that the platinum flame retardant was omitted.

[0092] Comparative Example 3

[0093] The method of Example 5 was followed, except that the phosphate glass powder (melting point of 450° C.) in Comparative Example 5 was replaced with silicate glass powder (melting point of 500° C.).

[0094] Comparative Example 4

[0095] The method of Example 5 is used as the reference, except that the inorganic filler is a mixture of wollastonite and mica powder in a mass ratio of 1:1.

[0096] Test Example 1

[0097] The ceramic silicone rubber prepared in the embodiment and the comparative example was subjected to performance tests, and the test results are shown in Table 1, wherein the tensile strength and elongation at break were tested according to the GB / T 1040 method; the breakdown strength was tested according to the GB / T 1408 method; the ceramic bending strength was tested according to the GB / T 6569-2006 method; the ceramic appearance was specifically tested by touching it with the hand and dropping it on the ground and listening to the sound. If it feels hard when touched by the hand and the sound is crisp, it means that it is hard. At the same time, it can be visually observed after dropping it on the ground. If there are no cracks, it means that it is intact.

[0098] Table 1 Performance test results of ceramic silicone rubber in Examples and Comparative Examples

[0099]

[0100] It can be seen from Table 1 that the ceramic silicone rubber prepared in Examples 1 to 5 of the present invention can maintain relatively high tensile strength and elongation at break while ensuring the hardness of the ceramic shell.

[0101] In addition, it can be seen from Table 2 that in Comparative Example 1, glass powder is not used, and the ceramic silicone rubber prepared has a poor ceramic appearance and large surface cracks. In Comparative Example 2, platinum flame retardant is not used, and the flame retardant properties of the ceramic silicone rubber prepared are poor, and the ceramic strength is poor. In Comparative Example 3, silicate glass powder is used, and the tensile strength and elongation at break of the ceramic silicone rubber prepared are reduced. In Comparative Example 4, montmorillonite is not used as an inorganic filler, and the elongation at break and the breakdown strength of the ceramic silicone rubber prepared are reduced.

[0102] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A ceramic silicone rubber is prepared from the following raw materials in parts by weight: 90-105 parts of methyl vinyl silicone rubber; 35-45 parts of fumed silica; 3-10 parts of hydroxy silicone oil; Silane coupling agent 0.1-8 parts; 1 to 75 parts of inorganic filler; the inorganic filler is mica powder, montmorillonite and wollastonite; 10 to 30 parts of low-melting-point glass powder, wherein the melting point of the low-melting-point glass powder is 400 to 600° C., and the low-melting-point glass powder is borate glass powder and / or phosphate glass powder; 0.1 to 0.3 parts of a platinum flame retardant, wherein the mass content of platinum in the platinum flame retardant is 1000 to 3000 ppm; 0.5-1.5 parts of vulcanizing agent; Internal release agent 0.1 to 0.5 parts.

2. The ceramic silicone rubber according to claim 1, characterized in that: The mass ratio of the mica powder, montmorillonite and wollastonite is 15-25:15-25:15-25.

3. The ceramic silicone rubber according to claim 1, characterized in that: The vinyl molar content of the methyl vinyl silicone rubber is 0.01-0.3%; the number average molecular weight of the methyl vinyl silicone rubber is 600,000-700,000.

4. The ceramic silicone rubber according to claim 1, characterized in that: The particle size of the fumed silica is 10 to 50 nm, and the specific surface area is 200 to 300 m 2 / g.

5. The ceramic silicone rubber according to claim 1, characterized in that: The silane coupling agent includes one or more of vinyl trimethoxy silane, vinyl triethoxy silane and butadienyl triethoxy silane.

6. The ceramic silicone rubber according to claim 1, characterized in that: The vulcanizing agent is an organic peroxide.

7. The ceramic silicone rubber according to claim 1, characterized in that: The internal mold release agent is zinc stearate and stearic acid, and the mass ratio of zinc stearate to stearic acid is 2 to 2.5:

1.

8. The method for preparing the ceramic silicone rubber according to any one of claims 1 to 7, comprising the following steps: Mixing methyl vinyl silicone rubber, fumed silica, hydroxy silicone oil, silane coupling agent, inorganic filler, low melting point glass powder, platinum flame retardant, vulcanizing agent and internal release agent to obtain a mixed material; The mixed material is vulcanized to obtain the ceramic silicone rubber.

9. The preparation method according to claim 8, characterized in that: The mixing includes: first mixing methyl vinyl silicone rubber, hydroxy silicone oil, fumed silica and an internal release agent to obtain a first mixed material; second mixing the first mixed material, a silane coupling agent, an inorganic filler, a low melting point glass powder and a platinum flame retardant to obtain a second mixed material; and third mixing the second mixed material and a vulcanizing agent; The vulcanization includes sequentially performing a first vulcanization and a second vulcanization; the temperature of the first vulcanization is 100-120° C., and the time is 60-90 minutes; the temperature of the second vulcanization is 180-220° C., and the time is 90-120 minutes.

10. Use of the ceramic silicone rubber according to any one of claims 1 to 7 or the ceramic silicone rubber prepared by the preparation method according to claim 8 or 9 in wires and cables or new energy vehicles.

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