A ceramifiable refractory silicone rubber foaming tape and its preparation method

Abstract

The present invention belongs to the technical field of ceramic silicone rubber, and specifically relates to a ceramic refractory silicone rubber foaming belt and a preparation method thereof. The ceramic refractory silicone rubber provided by the present invention comprises the following raw materials in parts by weight: 50-70 parts of methyl vinyl silicone rubber with a vinyl content of 0.04-0.06%, 30-50 parts of methyl vinyl silicone rubber with a vinyl content of 0.2-0.24%, 20-35 parts of modified silicone rubber, 35-45 parts of fumed silica, 30-40 parts of muscovite, 5-15 parts of glass powder, 3-8 parts of zinc borate, 0.02-0.08 parts of a first catalyst, 1-4 parts of hydrogen-containing silicone oil, and 1-4 parts of a vulcanizing agent. The ceramic refractory silicone rubber provided by the present invention can greatly improve the strength of the ceramic layer after calcination by adding a specific modified silicone rubber, and improve the mechanical properties and flame retardant properties of the ceramic silicone rubber.

Description

Technical Field

[0001] The present invention belongs to the technical field of ceramized silicone rubber, and particularly relates to a ceramized refractory silicone rubber foamed tape and a preparation method thereof. Background Art

[0002] As a material with good insulation performance and flame retardancy, silicone rubber is widely used in refractory materials. However, in case of fire, silicone rubber will turn into powder under the burning of flame, and can hardly maintain its strength, greatly reducing its protective performance in fire. To solve the above problems, it is found that doping some inorganic fillers in silicone rubber can make them melt under high temperature conditions and then form a dense ceramic layer, which can effectively solve the above problems. Therefore, ceramized silicone rubber has received more and more attention.

[0003] Ceramized silicone rubber generally uses vinyl silicone rubber as the main material, and a flame retardant, a ceramic-forming filler, a flux, a cross-linking agent, etc. are added to the vinyl silicone rubber. At high temperature, the silicone rubber will decompose to produce silicon dioxide, which will undergo a eutectic reaction with the melted inorganic filler to form a hard and dense ceramic layer. However, with the development of society and higher safety performance requirements, people have put forward higher requirements for the strength of the ceramic layer after calcination. Through research, it is found that when magnesium hydroxide and strong alumina inorganic fillers are added to silicone rubber, they will form MgAl 2 Si 4 O 12 crystals at high temperature, which can effectively improve the strength of the ceramic layer after calcination. However, due to the easy agglomeration of magnesium hydroxide and aluminum hydroxide when added as fillers, uneven distribution in the silicone rubber system, and poor compatibility with the silicone rubber system, etc., it hinders the formation of more MgAl 2 Si 4 O 12 crystals, thus limiting the improvement of the strength of the ceramic layer after calcination. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the strength improvement of the ceramic layer after calcination is limited when using magnesium hydroxide and aluminum hydroxide as inorganic fillers in the existing ceramized silicone rubber, and further provide a ceramized refractory silicone rubber foamed tape and a preparation method thereof.

[0005] To solve the above problems, the solution of the present invention is as follows:

[0006] A ceramized refractory silicone rubber, by weight, comprises the following raw materials:

[0007] 50-70 parts of methyl vinyl silicone rubber with a vinyl content of 0.04-0.06%, 30-50 parts of methyl vinyl silicone rubber with a vinyl content of 0.2-0.24%, 20-35 parts of modified silicone rubber, 35-45 parts of fumed silica, 30-40 parts of muscovite, 5-15 parts of glass powder, 3-8 parts of zinc borate, 0.02-0.08 parts of the first catalyst, 1-4 parts of hydrogen-containing silicone oil, and 1-4 parts of vulcanizing agent.

[0008] Preferably, the preparation method of the modified silicone rubber includes the following steps:

[0009] 1) Mix hydrogen-containing silicone rubber, the second catalyst, trichlorovinylsilane, and the first organic solvent and react. After the reaction ends, add sodium amide and continue to react. After the continuous reaction ends, wash and dry to obtain amino-modified hydrogen-containing silicone rubber;

[0010] 2) Mix the amino-modified hydrogen-containing silicone rubber prepared in step 1), the second organic solvent, and water, ultrasonically disperse, then add aluminum salt and magnesium salt to the ultrasonic dispersion, stir, then adjust the pH of the mixed solution to 10-13, continue to stir, stand, filter, wash the filter cake with water, and dry to obtain the modified silicone rubber.

[0011] Preferably, the mass ratio of the hydrogen-containing silicone rubber, the second catalyst, trichlorovinylsilane, the first organic solvent, and sodium amide is 1:(0.05-0.2):(0.3-0.8):(10-20):(0.32-0.4).

[0012] Preferably, the viscosity of the hydrogen-containing silicone rubber is 2000-3000 mPa·s; the hydrogen-containing silicone rubber in the present invention is an existing product, which can be obtained through commercial purchase or prepared by existing methods. For example, mix vinyl-terminated polydimethylsiloxane, hydrogen-containing silicone oil, and Pt catalyst (the mass ratio of vinyl-terminated polydimethylsiloxane, hydrogen-containing silicone oil, and Pt catalyst is 100:3.5:0.2), heat and react at 60 °C for 10 h, and after the reaction ends, wash with ethanol and water in sequence and dry to obtain hydrogen-containing silicone rubber.

[0013] The second catalyst is catalyst Pt, the first organic solvent is selected from toluene and absolute ethanol, and the mass ratio of toluene and absolute ethanol is 10:(1-3);

[0014] The addition amount of the aluminum salt is 40-65% of the mass of the hydrogen-containing silicone rubber, and the addition amount of the magnesium salt is 15-30% of the mass of the hydrogen-containing silicone rubber;

[0015] The second organic solvent is ethanol, and the mass ratio of the second organic solvent and water is (0.2-0.6):1;

[0016] In step 2), the addition amount of the second organic solvent is 4-7 times the mass of the hydrogen-containing silicone rubber.

[0017] Preferably, in step 1), the reaction temperature is 60-75 °C, the reaction time is 5-15 h, and the continued reaction time is 1-5 h;

[0018] In the washing step in step 1), ethanol and water are used for washing;

[0019] In step 2), the stirring temperature is 55-70 °C, the stirring time is 0.5-3 h, the continued stirring temperature is 55-70 °C, the continued stirring time is 1-3 h, the standing temperature is 55-70 °C, and the standing time is 3-8 h;

[0020] The ultrasonic dispersion time is 0.5-1.5 h, and the ultrasonic power is 200-500 W;

[0021] The pH of the mixed solution is adjusted to 10-13 with a sodium hydroxide solution with a mass fraction of 8-15%;

[0022] The aluminum salt is selected from aluminum chloride, and the magnesium salt is selected from magnesium chloride.

[0023] Preferably, the first catalyst is composed of diethyl phthalate platinum complex and Raney nickel, and the mass ratio of diethyl phthalate platinum complex to Raney nickel is (1.5-2.5):1;

[0024] The hydrogen content of the hydrogen-containing silicone oil is 0.1-0.25%, and the viscosity is 100-200 mPa·s;

[0025] The vulcanizing agent is selected from bis(2,4-dichlorobenzoyl) peroxide.

[0026] In the present invention, for the methyl vinyl silicone rubber with a vinyl content of 0.04-0.06% and the methyl vinyl silicone rubber with a vinyl content of 0.2-0.24%, the vinyl content refers to the molar content. The methyl vinyl silicone rubber with a vinyl content of 0.04-0.06% and the methyl vinyl silicone rubber with a vinyl content of 0.2-0.24% used in the present invention both have a molecular weight selected from 550,000-750,000.

[0027] The present invention also provides a preparation method of the above-mentioned ceramifiable refractory silicone rubber, comprising the following steps:

[0028] Mix the methyl vinyl silicone rubber with a vinyl content of 0.04-0.06%, the methyl vinyl silicone rubber with a vinyl content of 0.2-0.24%, the modified silicone rubber and fumed silica, add mica, glass powder, zinc borate, the first catalyst, and the hydrogen-containing silicone oil for continuous mixing after the mixing is completed, evacuate after the continuous mixing is completed, then add the desulfurizing agent for further mixing, and vulcanize to obtain the ceramifiable refractory silicone rubber.

[0029] Preferably, the kneading temperature is 80 - 100 °C, the kneading time is 30 - 60 min, the continued kneading temperature is 90 - 110 °C, and the continued kneading time is 1 - 3 h;

[0030] The temperature for vacuum pumping operation is 120 - 150 °C, and the vacuum pumping time is 20 - 40 min;

[0031] The time for re - kneading is 20 - 40 min;

[0032] The vulcanization temperature is 160 - 180 °C, and the vulcanization time is 1 - 3 h.

[0033] The present invention also provides a ceramifiable refractory silicone rubber foam tape, which includes the ceramifiable refractory silicone rubber described above;

[0034] Preferably, the ceramifiable refractory silicone rubber foam tape further includes fiberglass cloth.

[0035] The present invention also provides a preparation method of the ceramifiable refractory silicone rubber foam tape described above, including the following steps: obtaining the ceramifiable refractory silicone rubber and fiberglass cloth through a calendering process.

[0036] The technical solution of the present invention has the following advantages:

[0037] For the ceramifiable refractory silicone rubber provided by the present invention, methyl vinyl silicone rubber with a vinyl content of 0.04 - 0.06% and methyl vinyl silicone rubber with a vinyl content of 0.2 - 0.24% are used as the main materials. On this basis, a modified silicone rubber is introduced. The preparation of the modified silicone rubber uses hydrogen - containing silicone rubber as the main material. Through trichlorovinylsilane and sodium amide, a multi - amino structure is grafted onto the hydrogen - containing silicone rubber to obtain an amino - modified hydrogen - containing silicone rubber. Then, the amino - modified hydrogen - containing silicone rubber is dispersed, and aluminum salts and magnesium salts are added. Under the chelation of amino groups, magnesium ions and aluminum ions will be uniformly dispersed on the surface of the hydrogen - containing silicone rubber. Subsequently, magnesium hydroxide and aluminum hydroxide are formed under alkaline conditions. After that, due to the presence of active hydrogen in the modified silicone rubber, it further cross - links with methyl vinyl silicone rubber to form a network structure, and magnesium hydroxide and aluminum hydroxide will be uniformly confined in the grid structure, achieving the purpose of uniform dispersion. By adding a specific modified silicone rubber, the present invention can better realize the dispersion of magnesium hydroxide and aluminum hydroxide, and increase their compatibility, which is beneficial to the formation of more MgAl 2 Si 4 O 12 crystals, greatly improving the strength of the ceramic layer after calcination. In addition, the present invention introduces fillers such as fumed silica, muscovite, glass powder, zinc borate, and hydrogen - containing silicone oil into the silicone rubber system. The mutual cooperation of several materials effectively improves the mechanical properties and flame - retardant properties of the ceramifiable silicone rubber. Detailed Embodiments

[0038] The following embodiments are for further understanding of the present invention, which are not limited to the best mode described above and do not limit the protection scope of the present invention.

[0039] For the experimental steps or conditions not specified in the following embodiments of the present invention, the conventional experimental steps and conditions adopted in the existing literature in this field can be implemented. For the reagents or instruments whose manufacturers are not specified, they are all conventional reagents or instruments that can be obtained through commercial purchase.

[0040] Example 1

[0041] This example provides a preparation method of ceramifiable refractory silicone rubber, including the following steps:

[0042] 50 kg of methyl vinyl silicone rubber with a vinyl content of 0.05%, 30 kg of methyl vinyl silicone rubber with a vinyl content of 0.2%, 20 kg of modified silicone rubber and 40 kg of fumed silica are kneaded in a kneader. The kneading temperature is 90 °C and the kneading time is 60 min. After the kneading is completed, 30 kg of mica, 10 kg of glass powder, 5 kg of zinc borate, 0.04 kg of diethyl phthalate platinum complex, 0.02 kg of Raney nickel, and 2 kg of hydrogen-containing silicone oil (hydrogen content is 0.2%, viscosity is 150 mPa·s) are added and kneaded continuously. The continuous kneading temperature is 100 °C and the continuous kneading time is 2 h. After the continuous kneading is completed, vacuum is drawn at 140 °C for 40 min, and then 2 kg of bis(2,4-dichlorobenzoyl) peroxide is added and kneaded on an open mill for 20 min, and vulcanized at 170 °C for 1.5 h to obtain the ceramifiable refractory silicone rubber.

[0043] The preparation method of the modified silicone rubber includes the following steps:

[0044] 1) 1 kg of hydrogen-containing silicone oil (viscosity is 3000 mPa·s), 0.1 kg of catalyst Pt, 0.5 kg of trichlorovinylsilane, 10 kg of toluene and 1 kg of absolute ethanol are mixed and reacted. The reaction temperature is 70 °C and the reaction time is 10 h. After the reaction is completed, 0.38 kg of sodium amide is added and the reaction continues for 3 h. After the continuous reaction is completed, it is washed successively with ethanol and water and dried to obtain amino-modified hydrogen-containing silicone rubber;

[0045] 2) The amino-modified hydrogen-containing silicone rubber prepared in step 1), 5 kg of ethanol and 10 kg of water are mixed and ultrasonically dispersed for 1.0 h. The ultrasonic power is 400 W. Then, 5 mol of AlCl 3 and 2.5 mol of MgCl 2, stir at 60 °C for 1.0 h, then add a sodium hydroxide solution with a mass fraction of 10% to adjust the pH of the mixture to 12, continue stirring at 60 °C for 1.5 h, then let it stand at 60 °C for 6 h, filter, wash the filter cake with water, and dry to obtain the modified silicone rubber. In the modified silicone rubber, the mass of aluminum hydroxide accounts for 12.5% of the total mass of the modified silicone rubber, and the mass of magnesium hydroxide accounts for 4.2% of the total mass of the modified silicone rubber.

[0046] Example 2

[0047] This example provides a method for preparing a ceramizable refractory silicone rubber, which includes the following steps:

[0048] Mix 50 kg of methyl vinyl silicone rubber with a vinyl content of 0.05%, 35 kg of methyl vinyl silicone rubber with a vinyl content of 0.2%, 25 kg of modified silicone rubber, and 50 kg of fumed silica in a kneader. The kneading temperature is 90 °C and the kneading time is 120 min. After kneading, add 35 kg of muscovite, 5 kg of glass powder, 4 kg of zinc borate, 0.03 kg of diethyl phthalate platinum complex, 0.02 kg of Raney nickel, and 1.5 kg of hydrogen-containing silicone oil (hydrogen content is 0.2%, viscosity is 150 mPa·s) and continue kneading. The continued kneading temperature is 100 °C and the continued kneading time is 2 h. After the continued kneading, evacuate at 130 °C for 40 min, then add 2 kg of bis(2,4-dichlorobenzoyl) peroxide on an open mill and knead for 20 min, and vulcanize at 160 °C for 1.5 h to obtain the ceramizable refractory silicone rubber.

[0049] The method for preparing the modified silicone rubber includes the following steps:

[0050] 1) Mix 1 kg of hydrogen-containing silicone rubber (viscosity is 3000 mPa·s), 0.1 kg of catalyst Pt, 0.5 kg of trichlorovinylsilane, 15 kg of toluene, and 1 kg of absolute ethanol and react. The reaction temperature is 65 °C and the reaction time is 10 h. After the reaction, add 0.4 kg of sodium amide and continue to react for 3 h. After the continued reaction, wash successively with ethanol and water, and dry to obtain amino-modified hydrogen-containing silicone rubber;

[0051] 2) Mix the amino-modified hydrogen-containing silicone rubber prepared in step 1), 5 kg of ethanol, and 10 kg of water, and ultrasonically disperse for 1.5 h. The ultrasonic power is 400 W. Then add 4.5 mol of AlCl 3 , 3 mol of MgCl 2, stir at 60 °C for 1.0 h, then add a sodium hydroxide solution with a mass fraction of 10% to adjust the pH of the mixed solution to 12, continue stirring at 60 °C for 1.5 h, then stand at 60 °C for 6 h, filter, wash the filter cake with water, and dry to obtain the modified silicone rubber. In the modified silicone rubber, the mass of aluminum hydroxide accounts for 8.5% of the total mass of the modified silicone rubber, and the mass of magnesium hydroxide accounts for 4.5% of the total mass of the modified silicone rubber.

[0052] Example 3

[0053] This example provides a method for preparing ceramifiable refractory silicone rubber, which includes the following steps:

[0054] Mix 50 kg of methyl vinyl silicone rubber with a vinyl content of 0.05%, 40 kg of methyl vinyl silicone rubber with a vinyl content of 0.2%, 30 kg of modified silicone rubber, and 50 kg of fumed silica in a kneader. The kneading temperature is 90 °C, and the kneading time is 120 min. After kneading, add 40 kg of muscovite, 5 kg of glass powder, 4 kg of zinc borate, 0.03 kg of platinum complex of diethyl phthalate, 0.02 kg of Raney nickel, and 2.0 kg of hydrogen-containing silicone oil (hydrogen content is 0.2%, viscosity is 150 mPa·s) and continue kneading. The continued kneading temperature is 100 °C, and the continued kneading time is 2 h. After the continued kneading is completed, evacuate at 130 °C for 60 min, then add 2.5 kg of bis(2,4-dichlorobenzoyl) peroxide on an open mill and knead for 20 min, and vulcanize at 160 °C for 1.5 h to obtain the ceramifiable refractory silicone rubber.

[0055] The method for preparing the modified silicone rubber includes the following steps:

[0056] 1) Mix 1 kg of hydrogen-containing silicone rubber (viscosity is 3000 mPa·s), 0.1 kg of catalyst Pt, 0.5 kg of trichlorovinylsilane, 15 kg of toluene, and 1 kg of absolute ethanol and react. The reaction temperature is 65 °C, and the reaction time is 10 h. After the reaction, add 0.4 kg of sodium amide and continue to react for 4 h. After the continued reaction is completed, wash successively with ethanol and water, and dry to obtain amino-modified hydrogen-containing silicone rubber;

[0057] 2) Mix the amino-modified hydrogen-containing silicone rubber prepared in step 1), 5 kg of ethanol, and 10 kg of water, and ultrasonically disperse for 1.5 h. The ultrasonic power is 400 W, and then add 4.5 mol of AlCl 3 3 mol of MgCl 2, stir at 60 °C for 1.5 h, then add a sodium hydroxide solution with a mass fraction of 10% to adjust the pH of the mixture to 12, continue stirring at 60 °C for 2 h, then let it stand at 60 °C for 6 h, filter, wash the filter cake with water, and dry to obtain the modified silicone rubber. In the modified silicone rubber, the mass of aluminum hydroxide accounts for 8.8% of the total mass of the modified silicone rubber, and the mass of magnesium hydroxide accounts for 4.7% of the total mass of the modified silicone rubber.

[0058] Example 4

[0059] This example provides a preparation method of ceramizable refractory silicone rubber, which includes the following steps:

[0060] Mix 50 kg of methyl vinyl silicone rubber with a vinyl content of 0.05%, 40 kg of methyl vinyl silicone rubber with a vinyl content of 0.2%, 28 kg of modified silicone rubber, and 48 kg of fumed silica in a kneader. The kneading temperature is 90 °C, and the kneading time is 80 min. After the kneading is completed, add 35 kg of muscovite, 5 kg of glass powder, 4 kg of zinc borate, 0.04 kg of diethyl phthalate platinum complex, 0.01 kg of Raney nickel, and 2.0 kg of hydrogen-containing silicone oil (hydrogen content is 0.2%, viscosity is 150 mPa·s) and continue kneading. The continued kneading temperature is 100 °C, and the continued kneading time is 2 h. After the continued kneading is completed, evacuate at 130 °C for 60 min, then add 2.5 kg of bis(2,4-dichlorobenzoyl) peroxide on an open mill and knead for 20 min, and vulcanize at 160 °C for 1.5 h to obtain the ceramizable refractory silicone rubber.

[0061] The preparation method of the modified silicone rubber includes the following steps:

[0062] 1) Mix 1 kg of hydrogen-containing silicone rubber (viscosity is 3000 mPa·s), 0.1 kg of catalyst Pt, 0.5 kg of trichlorovinylsilane, 15 kg of toluene, and 1 kg of absolute ethanol and react. The reaction temperature is 65 °C, and the reaction time is 10 h. After the reaction is completed, add 0.4 kg of sodium amide and continue to react for 6 h. After the continued reaction is completed, wash successively with ethanol and water, and dry to obtain amino-modified hydrogen-containing silicone rubber;

[0063] 2) Mix the amino-modified hydrogen-containing silicone rubber prepared in step 1), 6 kg of ethanol, and 10 kg of water, and ultrasonically disperse for 2.0 h. The ultrasonic power is 400 W, and then add 4.5 mol of AlCl 3 3 mol of MgCl 2, stir at 60 °C for 1.0 h, then add a sodium hydroxide solution with a mass fraction of 10% to adjust the pH of the mixture to 13, continue stirring at 60 °C for 1.5 h, then let it stand at 60 °C for 10 h, filter, wash the filter cake with water, and dry to obtain the modified silicone rubber. In the modified silicone rubber, the mass of aluminum hydroxide accounts for 9.2% of the total mass of the modified silicone rubber, and the mass of magnesium hydroxide accounts for 4.9% of the total mass of the modified silicone rubber.

[0064] Comparative Example 1

[0065] This comparative example provides a method for preparing ceramizable refractory silicone rubber, which includes the following steps:

[0066] Mix 70 kg of methyl vinyl silicone rubber with a vinyl content of 0.05%, 30 kg of methyl vinyl silicone rubber with a vinyl content of 0.2%, and 40 kg of fumed silica in a kneader. The kneading temperature is 90 °C and the kneading time is 60 min. After kneading, add 30 kg of mica, 10 kg of glass powder, 5 kg of zinc borate, 0.04 kg of diethyl phthalate platinum complex, 0.02 kg of Raney nickel, and 2 kg of hydrogen-containing silicone oil (hydrogen content is 0.2%, viscosity is 150 mPa·s) and continue kneading. The continued kneading temperature is 100 °C and the continued kneading time is 2 h. After the continued kneading is completed, evacuate at 140 °C for 40 min, then add 2 kg of bis(2,4-dichlorobenzoyl) peroxide on a mill and knead for 20 min, and vulcanize at 170 °C for 1.5 h to obtain the ceramizable refractory silicone rubber.

[0067] Comparative Example 2

[0068] This comparative example provides a method for preparing ceramizable refractory silicone rubber, which includes the following steps:

[0069] Mix 50 kg of methyl vinyl silicone rubber with a vinyl content of 0.05%, 30 kg of methyl vinyl silicone rubber with a vinyl content of 0.2%, 16.66 kg of amino-modified hydrogen-containing silicone rubber, 2.5 kg of aluminum hydroxide, 0.84 kg of magnesium hydroxide, and 40 kg of fumed silica in a kneader. The kneading temperature is 90 °C and the kneading time is 60 min. After kneading, add 30 kg of mica, 10 kg of glass powder, 5 kg of zinc borate, 0.04 kg of diethyl phthalate platinum complex, 0.02 kg of Raney nickel, and 2 kg of hydrogen-containing silicone oil (hydrogen content is 0.2%, viscosity is 150 mPa·s) and continue kneading. The continued kneading temperature is 100 °C and the continued kneading time is 2 h. After the continued kneading is completed, evacuate at 140 °C for 40 min, then add 2 kg of bis(2,4-dichlorobenzoyl) peroxide on a mill and knead for 20 min, and vulcanize at 170 °C for 1.5 h to obtain the ceramizable refractory silicone rubber.

[0070] The preparation method of the amino-modified hydrogen-containing silicone rubber comprises the following steps:

[0071] Mix 1 kg of hydrogen-containing silicone rubber (viscosity: 3000 mPa·s), 0.1 kg of catalyst Pt, 0.5 kg of trichlorovinylsilane, 10 kg of toluene and 1 kg of absolute ethanol and react. The reaction temperature is 70 °C and the reaction time is 10 h. After the reaction ends, add 0.38 kg of sodium amide and continue to react for 3 h. After the continuous reaction ends, wash successively with ethanol and water, and then dry to obtain the amino-modified hydrogen-containing silicone rubber.

[0072] Comparative Example 3

[0073] This comparative example provides a preparation method of a ceramizable refractory silicone rubber. The difference compared with Example 1 is that the preparation method of the modified silicone rubber comprises the following steps:

[0074] Mix 1 kg of hydrogen-containing silicone rubber (viscosity: 3000 mPa·s), 5 kg of ethanol and 10 kg of water, and perform ultrasonic dispersion for 1.0 h with an ultrasonic power of 400 W. Then add 5 mol of AlCl 3 and 2.5 mol of MgCl 2 to the ultrasonic dispersion liquid, stir at 60 °C for 1.0 h, then add a sodium hydroxide solution with a mass fraction of 10% to adjust the pH of the mixed liquid to 12, continue to stir at 60 °C for 1.5 h, then stand at 60 °C for 6 h, filter, wash the filter cake with water, and dry to obtain the modified silicone rubber.

[0075] Test Example 1

[0076] Test the mechanical properties of the ceramizable refractory silicone rubber prepared in the above examples according to the standard of GB / T 528-2009;

[0077] The flame retardancy performance is tested according to GB / T11020-2005;

[0078] The test results are shown in Table 1.

[0079] Table 1

[0080]

[0081]

[0082] Test Example 2

[0083] Make the ceramizable refractory silicone rubbers prepared in the above examples and comparative examples into test specimens with dimensions of 100*30*3 mm, and calcine them in a muffle furnace at 800 °C for 15 min in an air atmosphere, and test the flexural performance of the porcelain products after calcination.

[0084] The test results are shown in Table 2.

[0085] Table 2

[0086]

[0087]

[0088] Obviously, for those of ordinary skill in the art, other variations can be made on the basis of the above embodiments, and the obvious variations thus brought about are still within the protection scope of the present invention.

Claims

1. A ceramic refractory silicone rubber, characterized in that: The following raw materials are included in parts by weight: 50-70 parts of methyl vinyl silicone rubber with a vinyl content of 0.04-0.06%, 30-50 parts of methyl vinyl silicone rubber with a vinyl content of 0.2-0.24%, 20-35 parts of modified silicone rubber, 35-45 parts of fumed silica, 30-40 parts of muscovite, 5-15 parts of glass powder, 3-8 parts of zinc borate, 0.02-0.08 parts of the first catalyst, 1-4 parts of hydrogenated silicone oil, and 1-4 parts of a vulcanizing agent; The preparation method of the modified silicone rubber comprises the following steps: 1) mixing hydrogenated silicone rubber, a second catalyst, trichlorovinyl silane and a first organic solvent and reacting them, adding sodium amide after the reaction, continuing the reaction, washing and drying after the reaction, and obtaining amino-modified hydrogenated silicone rubber; 2) The amino-modified hydrogenated silicone rubber prepared in step 1), the second organic solvent and water are mixed, ultrasonically dispersed, and then aluminum salt and magnesium salt are added to the ultrasonic dispersion, stirred, and then the pH of the mixed solution is adjusted to 10-13, and the stirring is continued, allowed to stand, filtered, the filter cake is washed with water, and dried to obtain the modified silicone rubber.

2. The ceramic refractory silicone rubber according to claim 1, characterized in that: The mass ratio of the hydrogenated silicone rubber, the second catalyst, trichlorovinyl silane, the first organic solvent and sodium amide is 1: (0.05-0.2): (0.3-0.8): (10-20): (0.32-0.4).

3. The ceramic refractory silicone rubber according to claim 1, characterized in that: The viscosity of the hydrogen-containing silicone rubber is 2000-3000 mPa •s; The second catalyst is catalyst Pt, the first organic solvent is selected from toluene and anhydrous ethanol, and the mass ratio of toluene to anhydrous ethanol is 10:(1-3); The amount of aluminum salt added is 40-65% of the mass of hydrogen-containing silicone rubber, and the amount of magnesium salt added is 15-30% of the mass of hydrogen-containing silicone rubber; The second organic solvent is ethanol, and the mass ratio of the second organic solvent to water is (0.2-0.6):1; In step 2), the amount of the second organic solvent added is 4-7 times the mass of the hydrogen-containing silicone rubber.

4. The ceramic refractory silicone rubber according to claim 1, characterized in that: In step 1), the reaction temperature is 60-75°C, the reaction time is 5-15h, and the continued reaction time is 1-5h; The washing step in step 1) is performed using ethanol and water; In step 2), the stirring temperature is 55-70°C, the stirring time is 0.5-3h, the stirring temperature is continued to be 55-70°C, the stirring time is continued to be 1-3h, the standing temperature is 55-70°C, and the standing time is 3-8h; The ultrasonic dispersion time is 0.5-1.5h, and the ultrasonic power is 200-500W; The pH value of the mixed solution is adjusted to 10-13 using a sodium hydroxide solution with a mass fraction of 8-15%; The aluminum salt is selected from aluminum chloride, and the magnesium salt is selected from magnesium chloride.

5. The ceramic refractory silicone rubber according to claim 1, characterized in that: The first catalyst is composed of diethyl phthalate platinum complex and Raney nickel, and the mass ratio of diethyl phthalate platinum complex to Raney nickel is (1.5-2.5):1; The hydrogen content of the hydrogen-containing silicone oil is 0.1-0.25%, and the viscosity is 100-200 mPa •s; The vulcanizing agent is selected from bis(2,4-dichlorobenzoyl) peroxide.

6. The method for preparing the ceramic refractory silicone rubber according to any one of claims 1 to 5, characterized in that: The steps include: Methyl vinyl silicone rubber with a vinyl content of 0.04-0.06%, methyl vinyl silicone rubber with a vinyl content of 0.2-0.24%, modified silicone rubber and fumed silica are mixed, and muscovite, glass powder, zinc borate, a first catalyst, and hydrogen-containing silicone oil are added after the mixing is completed and the mixing is continued. After the mixing is completed, vacuum is drawn, and then a desulfurizer is added and mixed again, and vulcanization is performed to obtain the ceramicized refractory silicone rubber.

7. The preparation method according to claim 6, characterized in that: The mixing temperature is 80-100°C, the mixing time is 30-60min, the mixing temperature is continued to be 90-110°C, and the mixing time is continued to be 1-3h; The vacuum operation temperature is 120-150℃, and the vacuum time is 20-40min; The mixing time is 20-40 minutes again; The vulcanization temperature is 160-180°C and the vulcanization time is 1-3h.

8. A ceramic fire-resistant silicone rubber foam belt, characterized in that: The invention comprises the ceramicized refractory silicone rubber as described in any one of claims 1 to 5.

9. The ceramicized refractory silicone rubber foam belt according to claim 8, characterized in that: The ceramicized fire-resistant silicone rubber foaming belt also includes glass cloth.

10. The method for preparing the ceramicized refractory silicone rubber foam tape according to claim 9, characterized in that: The method comprises the following steps: obtaining the ceramicized refractory silicone rubber and glass cloth as described in any one of claims 1 to 5 through a calendering process.

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