Wide-temperature-range porcelainized fireproof plugging material and preparation method thereof

Abstract

The invention discloses a wide-temperature-range porcelainized fireproof plugging material and a preparation method thereof, and the wide-temperature-range porcelainized fireproof plugging material is prepared by blending a silicone rubber compound, porcelainized powder and a fluxing agent and performing vulcanization mold pressing. The fireproof plugging material is prepared by blending a silicone rubber compound, porcelainized powder, a fluxing agent and the like according to a proportion, and performing vulcanization mold pressing. The material has the characteristic of wide ceramization temperature range, and the initial ceramization temperature can be as low as 600 DEG C, so that the ceramic forming effect is better in the fire heating process, no obvious toxic smoke is released, the formed ceramic body is stable in structure and high-temperature-resistant, and the material is endowed with excellent long-acting fireproof plugging capacity.

Description

Technical Field

[0001] The invention relates to the technical field of fireproof materials, and in particular to a wide-temperature-range porcelain fireproof sealing material and a preparation method thereof. Background Art

[0002] Fire blocking technology mainly studies the use of blocking materials with fireproof and heat-insulating effects to seal or fill various openings, holes, annular gaps and building gaps formed when various penetrations such as air ducts, process pipelines, cables, etc. pass through walls and floors in buildings. Fire blocking materials block various openings formed when penetrations such as cables and pipes pass through walls or floors, as well as the fire separation of cable trays, to prevent the spread of fire through these openings and gaps. The basic principle is that the blocking material expands to absorb heat and insulate, expands when exposed to fire to seal the gaps left by the combustion of combustibles, and prevents the spread of fire and toxic gases and smoke generated in the fire; absorbs heat and insulates to reduce the temperature of the back-fire surface of the penetration to prevent the combustion of combustibles on the back-fire surface. According to the composition and shape characteristics of the product, fire blocking materials can be divided into: inorganic blocking materials, organic blocking materials, organic-inorganic composite fireproof bags, etc.

[0003] The research on foreign fire blocking technology started in the 1970s. In the early days, sandbags were used as blocking materials. Since the fireproof effect of sandbags could not meet the engineering requirements, the blocking materials were improved by using corundum after the 1980s. However, corundum has obvious disadvantages, such as large mass, high bearing pressure and high possibility of collapse. Later, major companies began to increase their investment in research and development, among which 3M and Hilti were typical companies. Due to their advanced technology, environmentally friendly products, long service life, beautiful appearance and easy construction, the two companies quickly occupied the European and American markets. At the same time, the large demand for fire blocking related products has also spawned many small companies that produce various types of blocking materials.

[0004] In the early stage of fire blocking research in my country, relevant application research was mainly carried out with reference to the experience of ABB in Switzerland and Siemens in Germany. In the late 1980s, domestic experts tried to apply cast-type blocking materials in engineering, but their shortcomings were obvious and it was difficult to apply and replace them. In the 1990s, China established its own research team and launched a special research project on fire blocking materials. The fire blocking products studied mainly include fireproof bags, organic fire blocking materials, inorganic fire blocking materials and fireproof cement. These products occupy the main market of fire blocking projects, but they are gradually being eliminated by the market due to their backward technology, poor environmental protection and short service life.

[0005] In response to the problem of poor overall performance of building fireproof plugging products, foreign countries have mainly studied halogen-free intumescent fireproof plugging technology with EPDM rubber as the main material, and designed a modular plugging system suitable for different scenarios. The oxygen index of EPDM rubber is only 17.8%, which is a flammable material with a high fire hazard. It needs to be flame-retardantly modified to meet the needs of fireproof plugging (Xue Lei, Shang Ke, Wang Junsheng, Lin Guide, Jin Xing, Liu Dan, Yang Jinjun, Fire Science and Technology, 2019, 38(12): 1733-1735). However, the introduction of flame retardants will reduce the mechanical properties of the material, and the fire resistance limit of fireproof plugging with EPDM rubber as the main material can only reach 2 hours, and the material itself has high smoke toxicity.

[0006] At present, the main problems of organic sealing systems are poor flame retardant properties, cracking and powdering of sealing materials after fire, high smoke toxicity and insufficient fire resistance limit; inorganic products have better fire resistance but are easy to absorb moisture, are not smoke-proof and have limited construction, making it increasingly difficult to meet the requirements of high-efficiency, low-smoke and low-toxic fire sealing in enclosed spaces such as cable wells. Summary of the invention

[0007] The purpose of the present invention is to provide a wide temperature range porcelain fireproof plugging material and a preparation method thereof.

[0008] To achieve the above object, the present invention is implemented according to the following technical solutions:

[0009] The invention discloses a wide temperature range porcelain fireproof plugging material, which is obtained by mixing silicone rubber compound, porcelain powder and flux, and then vulcanizing and molding.

[0010] Furthermore, the flux is a mixture of a rare metal and a low-melting-point glass powder. The rare metal is any one of lanthanum oxide and cerium oxide. The low-melting-point glass powder is lead-free glass powder.

[0011] Preferably, the particle size of the melting point glass powder is 3 to 17 μm. The total content of the melting point glass powder is 4 to 8 wt%.

[0012] A method for preparing a wide temperature range porcelain fireproof plugging material of the present invention comprises the following steps:

[0013] S1: weigh the silicone rubber compound, porcelain powder and flux, blend them mechanically, mix the powders evenly and then add the vulcanizing agent and mix;

[0014] S2: The uniformly mixed material is molded and vulcanized on a flat vulcanizer, first hot pressed and then cold pressed, to obtain a wide temperature range porcelain fireproof sealing material.

[0015] The beneficial effects of the present invention are:

[0016] The present invention is a wide temperature range porcelain fireproof plugging material and its preparation method. Compared with the prior art, the present invention aims at the problems of high smoke toxicity, insufficient fire resistance and poor weather resistance of the existing fireproof plugging materials. The present invention introduces a wide temperature range porcelain system and utilizes the hydrogen bonding between a large number of hydroxyl groups on the surface of low-melting glass powder and silicone rubber to enhance the material, which is beneficial to processing and plugging construction. When the plugging material is exposed to fire and the temperature rises to the softening point of the low-melting glass powder, the low-melting glass powder first begins to melt to form a liquid phase. The liquid low-melting glass powder can react with the porcelain filler and the decomposition product of the silicone rubber to form a strong ceramic body. The formed ceramic body is resistant to high temperature, thereby preventing the spread of fire. The ceramic temperature of conventional ceramic silicone rubber needs to be above 1000°C. The low-melting glass powder containing rare metals such as lanthanum oxide and cerium oxide can reduce the ceramicization of the porcelain system to 600°C. The fire scene temperature in an actual fire can quickly rise to 600°C, and the peak temperature of the fire scene can reach 1000°C. The ceramicization temperature of 600℃ can better match the actual temperature change of the fire scene, which is conducive to the rapid ceramicization of the fireproof plugging material and achieves a plugging effect. The cerium oxide and cerium oxide contained in the catalytic ceramicization can also greatly reduce the release of smoke from the thermal decomposition of silicone rubber, so that the fireproof plugging material does not produce obvious toxic smoke when exposed to fire, and the smoke toxicity of the plugging material reaches ZA1 level, and the fire resistance limit reaches 3h. The low melting point glass powder used in the fireproof plugging material is lead-free, green and environmentally friendly, and harmless to the human body. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is the TG and DTG curve of the wide temperature range porcelain fireproof plugging material;

[0018] Figure 2 This is a picture of the wide temperature range porcelain fireproof plugging material after calcination at 1000℃;

[0019] Figure 3 This is a picture of the wide temperature range porcelain fireproof plugging material after calcination at 800℃;

[0020] Figure 4 This is a picture of the wide temperature range porcelain fireproof sealing material after calcination at 600℃. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention but are not intended to limit the present invention.

[0022] The invention discloses a wide temperature range porcelain fireproof plugging material, which is obtained by mixing silicone rubber compound, porcelain powder and flux, and then vulcanizing and molding.

[0023] Furthermore, the flux is a mixture of a rare metal and a low-melting-point glass powder. The rare metal is any one of lanthanum oxide and cerium oxide. The low-melting-point glass powder is lead-free glass powder.

[0024] Preferably, the particle size of the melting point glass powder is 3 to 17 μm. The total content of the melting point glass powder is 4 to 8 wt%.

[0025] A method for preparing a wide temperature range porcelain fireproof plugging material of the present invention comprises the following steps:

[0026] S1: weigh the silicone rubber compound, porcelain powder and flux, blend them mechanically, mix the powders evenly and then add the vulcanizing agent and mix;

[0027] S2: The uniformly mixed material is molded and vulcanized on a flat vulcanizer, first hot pressed and then cold pressed, to obtain a wide temperature range porcelain fireproof sealing material.

[0028] Example 1

[0029] The lead-free low-melting glass powder containing lanthanum oxide is ground and sieved to control its particle size to 3-17 μm, and 5 parts of the low-melting glass powder are mixed with 30 parts of silicone rubber compound and 65 parts of porcelain powder on an open mill. After the powder is mixed, 1wt% of vulcanizing agent is added and mixed for 30-45 minutes. The mixed material is molded and vulcanized on a flat vulcanizer with a molding pressure of 10 MPa, hot pressed at 165°C for 10 minutes and then cold pressed for 5 minutes to obtain a wide temperature range porcelain fireproof plugging material.

[0030] Example 2

[0031] The lead-free low-melting glass powder containing cerium oxide is ground and sieved to control its particle size to 3-17 μm, and 5 parts of the low-melting glass powder are mixed with 65 parts of silicone rubber compound and 35 parts of porcelain powder on an open mill. After the powder is mixed, 1wt% of vulcanizing agent is added and mixed for 30-45 minutes. The mixed material is molded and vulcanized on a flat vulcanizing press with a molding pressure of 10 MPa, hot pressed at 165°C for 10 minutes and then cold pressed for 5 minutes to obtain a wide temperature range porcelain fireproof plugging material.

[0032] The ceramicization effect of this material greatly inhibits the release of toxic smoke from high-temperature decomposition. The smoke toxicity reaches AQ1 level. The formed ceramic body is resistant to high temperatures, has excellent barrier properties, a fire resistance limit time of up to 3 hours, and excellent weather resistance. It can be widely used in high-rise building fire protection, nuclear power plant fire protection and other fields to improve the inherent fire safety level.

[0033] Experimental data:

[0034] Sample preparation:

[0035] Place the powder filler in a blast drying oven and dry it at 120℃ for 2h. Remove the moisture on the filler surface and set aside. After cleaning the roller of the open mill with anhydrous ethanol, place the weighed silicone rubber between the two rollers. After the silicone rubber is wrapped around the roller, add fumed silica first and mix for 20-30min. After mixing evenly, add fillers such as porcelain powder and glass powder until the silicone rubber and filler are evenly mixed. Finally, add the vulcanizer and mix for about 30min to obtain a uniform silicone rubber composite material. After refining the refined silicone rubber composite material, place it in a 2mm or 3mm stainless steel mold frame and perform compression vulcanization molding in a flat vulcanizer. The processing temperature of compression molding is 165℃. After hot pressing for 10 minutes at a pressure of 10MPa, cold pressing for 5 minutes will obtain a wide temperature range porcelain fireproof sealing material.

[0036] Flux is an inorganic filler with a lower melting point than the ceramic filler. When the silicone rubber composite material at high temperature reaches the softening point of the flux, the flux begins to melt and form a liquid phase. The liquid flux can react with the ceramic filler and the decomposition product of silicone rubber to form a strong ceramic body. The thermal properties of the wide temperature range ceramic fireproof plugging material were tested using the SDT Q600 synchronous thermal analyzer. During the test, the sample mass was controlled at about 10 mg, and the test was carried out at a heating rate of 20°C / min in a nitrogen atmosphere. Figure 1 These are the TG curve and DTG curve of a typical wide temperature range porcelain fireproof sealing material. The initial decomposition temperature of the material is 485.7°C, and it decomposes in two stages. The maximum weight loss rate in the first stage corresponds to a temperature of 470.8°C, and the maximum weight loss rate in the second stage corresponds to a temperature of 765.9°C. The residual mass at 800°C is 88.9wt%.

[0037] The wide temperature range porcelain fireproof sealing material was made into a 80mm×10mm×3mm specimen, which was placed in a muffle furnace and calcined at 1000℃, 800℃ and 600℃ for 30 minutes respectively. After the specimen was cooled to room temperature, the obtained ceramic body was photographed. Figure 2 , Figure 3 , Figure 4 These are the pictures after calcination at 1000℃, 800℃ and 600℃. It can be observed that the ceramic body formed after calcination at 1000℃ is overall white, dense and compact; the ceramic body formed after calcination at 800℃ is blue-gray; the ceramic body formed after calcination at 600℃ has a slight peeling.

[0038] The combustion performance of the wide temperature range porcelain fireproof sealing material was characterized by oxygen index and vertical combustion test. The LOI value of the material was 41.7%, and the vertical combustion reached V-0 level.

[0039] The samples of the wide temperature range porcelain fireproof plugging material were stacked to a thickness of 6mm, and the Shore A hardness tester was used to measure the Shore hardness of the material, and the hardness of the material was 82.5HA. The wide temperature range porcelain fireproof plugging material was cut into dumbbell-shaped specimens for tensile performance testing, and the tensile strength was 3.35MPa and the elongation at break was 112%.

[0040] According to the test of GB / T20285-2006 "Hazard Classification of Smoke Toxicity of Materials", the smoke toxicity of wide temperature range porcelain fireproof sealing materials can reach ZA1 level; the fireproof sealing made of this material can reach a fire resistance limit time of 3h according to the test of GB 23864-2023 "Fireproof Sealing Materials", see Table 1.

[0041] Table 1 Performance of vitrified fireproof plugging samples

[0042]

[0043] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. All technical variations made according to the technical solution of the present invention fall within the protection scope of the present invention.

Claims

1. A wide temperature range porcelain fireproof plugging material, characterized by: The wide temperature range porcelain fireproof plugging material is obtained by mixing silicone rubber compound, porcelain powder and flux and then vulcanizing and molding.

2. The wide temperature range porcelain fireproof plugging material according to claim 1, characterized in that: The auxiliary solvent is a mixture of rare metals and low-melting-point glass powder.

3. The wide temperature range porcelain fireproof plugging material according to claim 2, characterized in that: The rare metal is any one of lanthanum oxide and cerium oxide.

4. The wide temperature range porcelain fireproof plugging material according to claim 2, characterized in that: The low melting point glass powder is lead-free glass powder.

5. The wide temperature range porcelain fireproof plugging material according to claim 2 or 4, characterized in that: The particle size of the melting point glass powder is 3 to 17 μm.

6. The wide temperature range porcelain fireproof plugging material according to claim 2 or 4, characterized in that: The total content of the melting point glass powder is 4-8wt%.

7. A method for preparing a wide temperature range porcelain fireproof plugging material, characterized in that: The following steps are involved: S1: Weigh the silicone rubber compound, porcelain powder and flux, blend them mechanically, mix the powders evenly and then add the vulcanizing agent for mixing; S2: The uniformly mixed material is molded and vulcanized on a flat vulcanizer, first hot pressed and then cold pressed, to obtain a wide temperature range porcelain fireproof sealing material.

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