Refractory composition

Abstract

The present invention relates to a refractory composition comprising calcium hydroxide, titanium dioxide, aluminum sulfate, magnesium oxide, and aerogel.

Description

Refractory composition

[0001] The present invention relates to a fire-resistant composition that can be applied to various products, such as paints and interior / exterior materials, to improve the fire resistance of the products.

[0002] Buildings with fire-resistant structures pose a low risk of combustion due to adjacent fires, and even if an internal fire causes the interior to burn, major structural components such as walls, columns, and beams remain structurally intact, allowing the building to be reused with simple repairs. Accordingly, the Enforcement Decree of the Building Act in Korea individually prescribes fire-resistant structural standards for major structural components of buildings, including walls, columns, floors, beams, roofs, and stairs.

[0003] However, in developed countries, following the trend of rapid development of new building materials, the method of specifying concrete standards for fire-resistant structures by structural part has been abandoned. Instead, a method has been adopted in which the performance capability to withstand a fire for a certain period of time is determined for each structural part.

[0004] Conventionally, fire-resistant materials used as core materials for various buildings have utilized forms consisting of inserted honeycomb or urethane foam, or structurally combined with glass fibers or rock wool. However, these materials have issues regarding toxicity to the human body and thermal insulation properties, and thus fail to provide sufficient fire resistance performance at a time when fire resistance standards are gradually being strengthened.

[0005] As an example of prior art, Korean Registered Patent No. 0610059 presents a technology regarding a water-soluble inorganic foamed refractory agent and a refractory board using the same, comprising 1-3 weight% of a phosphorus-based flame retardant containing a carboxylic acid derivative; 15-20 weight% of a first metal oxide; 48-65 weight% of a second metal oxide containing silicon dioxide; 10-20 weight% of an aluminum hydroxide silicate mineral having a layered structure; and the remainder being water.

[0006] However, even in the case of the above technology, there is a problem in that sufficient fire resistance performance cannot be expected to be secured.

[0007] The present invention was developed to solve the problems of the prior art as described above, and aims to provide a refractory composition that is environmentally friendly and capable of sufficiently securing fire resistance and thermal insulation properties by primarily using inorganic materials.

[0008] A refractory composition according to the present invention for achieving the above-mentioned purpose (hereinafter referred to as the "composition of the present invention") is characterized by comprising calcium hydroxide, titanium dioxide, aluminum sulfate, magnesium oxide, and aerogel.

[0009] As an example, it is characterized by the additional inclusion of polyvinyl alcohol and carbon fiber.

[0010] As one example, the above aerogel is characterized as being a silica aerogel.

[0011] In addition, the above aerogel is characterized by further including alumina aerogel.

[0012] As an example, it is characterized by the additional inclusion of carbon powder.

[0013] In addition, the carbon powder is characterized as being a non-foamed carbon powder.

[0014] As an example, it is characterized by further including a mixture of methylparaben and zirconium silicate.

[0015] As an example, the carbon fiber is characterized as being a carbon fiber surface-modified by boron doping.

[0016] As explained above, the composition of the present invention has the advantage of being applicable to various products, such as paints and interior and exterior materials, to improve the fire resistance and thermal insulation of the products.

[0017] A preferred embodiment according to the present invention will be described in detail below with reference to the attached drawings.

[0018] The composition of the present invention is characterized by comprising calcium hydroxide, titanium dioxide, aluminum sulfate, magnesium oxide, and aerogel.

[0019] Preferably, the composition of the present invention is formulated to include 10 to 50 parts by weight of titanium dioxide, 10 to 50 parts by weight of aluminum sulfate, 10 to 50 parts by weight of magnesium oxide, and 10 to 50 parts by weight of aerogel, based on 100 parts by weight of calcium hydroxide.

[0020] The aforementioned calcium hydroxide releases water vapor upon thermal decomposition at high temperatures, thereby lowering the surrounding temperature and enabling the inhibition of flame spread. In other words, it contributes to fire suppression and heat insulation through rapid heat absorption and moisture release in the event of a fire.

[0021] The above titanium dioxide provides excellent thermal stability and increases the UV resistance of refractories due to its UV blocking properties.

[0022] The above aluminum sulfate possesses the characteristic of being able to withstand high temperatures without melting, and is designed to exhibit a function of suppressing flame spread by absorbing heat generated during a fire. In the case of the above aluminum sulfate, it is also designed to exhibit a function of increasing the physical strength of the refractory material.

[0023] The aforementioned magnesium oxide has excellent heat resistance and enhances safety by absorbing harmful gases generated during a fire. In other words, it contributes to reducing the generation of toxic gases during a fire.

[0024] The above-mentioned aerogel has a very low thermal conductivity, so it has excellent thermal insulation performance.

[0025] In particular, the present invention presents an example in which silica aerogel is applied as the aerogel. The silica aerogel has a very low thermal conductivity, which enables the function of maximizing thermal insulation performance to be exhibited.

[0026] In addition, the present invention provides an example in which alumina aerogel is further included in addition to silica aerogel. The alumina aerogel maintains stable physical and chemical properties even in high-temperature environments and has the advantage of being usable in various environments due to its high resistance to chemicals such as acids and alkalis.

[0027] In addition, it has the advantage of possessing relatively higher mechanical strength compared to silica aerogel, and enables excellent thermal insulation performance, although not to the same extent as silica aerogel.

[0028] In other words, the present invention utilizes silica aerogel and alumina aerogel in combination to not only provide thermal insulation but also improve high-temperature stability. While the structural stability of silica aerogel may slightly decrease at high temperatures, alumina aerogel compensates for this, thereby significantly improving stability at high temperatures.

[0029] Furthermore, since the strength of alumina aerogel is higher than that of silica aerogel, the combination of the two materials enables an increase in the overall mechanical strength of the refractory material. Additionally, alumina aerogel exhibits advantageous effects in terms of chemical resistance compared to silica aerogel.

[0030] Preferably, the silica aerogel and alumina aerogel are in a weight ratio of (4:6) to (6:4).

[0031] In addition, the composition of the present invention is characterized by further including polyvinyl alcohol and carbon fiber.

[0032] Preferably, it is appropriate to mix 10 to 30 parts by weight of polyvinyl alcohol and 5 to 15 parts by weight of carbon fiber with respect to 100 parts by weight of calcium hydroxide.

[0033] The above-mentioned polyvinyl alcohol strengthens the bonding strength of the refractory composition and enables it to maintain its physical properties even at high temperatures.

[0034] The above carbon fiber provides high tensile strength and heat resistance, and improves resistance to cracking through mechanical crosslinking, thereby significantly enhancing the mechanical strength of the refractory material.

[0035] In addition, an example is presented in which carbon powder is further added to the composition of the present invention.

[0036] Preferably, it is appropriate to mix the carbon powder in an amount of 10 to 50 parts by weight per 100 parts by weight of calcium hydroxide.

[0037] Carbon powder has high thermal conductivity, which allows it to effectively disperse heat in the event of a fire.

[0038] In addition, carbon powder is added to the composition of the present invention, and the carbon powder is characterized as being a non-foamed carbon powder.

[0039] As such, the addition of non-foamed carbon powder can result in better refractory performance compared to the addition of conventional carbon powder. Since non-foamed carbon powder does not undergo a foaming process, it possesses higher purity and density, which improves refractory performance in various aspects.

[0040] General carbon powder is carbon powder produced through a foaming process and has a porous structure, making it lightweight and highly adsorbent; however, due to this porous structure, its strength and stability may decrease at high temperatures, and it has the disadvantage of limited fire resistance performance due to low thermal conductivity.

[0041] In contrast, non-foamed carbon powder is carbon powder that has not undergone a foaming process; it possesses high density and purity and maintains a stable structure even at high temperatures. Consequently, non-foamed carbon powder has a higher thermal conductivity, which rapidly dissipates heat and improves refractory performance. Furthermore, due to its high density, it exhibits superior mechanical strength, and due to its high purity, it offers excellent chemical stability.

[0042] In addition, the present invention provides an example in which a mixture of methylparaben and zirconium silicate is further added in addition to the above compositions.

[0043] Preferably, it is appropriate to mix 5 to 15 parts by weight of a mixture of methylparaben and zirconium silicate with 100 parts by weight of calcium hydroxide.

[0044] The addition of methylparaben controls the degradation of the paste to improve the stability of its refractory performance.

[0045] However, when only methylparaben is added, there is a problem in that the thermal stability of methylparaben is somewhat weak, so the ability to control denaturation decreases when it is periodically exposed to high temperatures.

[0046] Accordingly, the present invention compensates for the decrease in thermal stability of methylparaben at high temperatures by adding zirconium silicate in addition to methylparaben. That is, a mixture of methylparaben and zirconium silicate is added so that the ability to control denaturation is stably expressed even when exposed to high temperatures.

[0047] Zirconium silicate has stable properties even at high temperatures and excellent thermal shock resistance; therefore, zirconium silicate is added to methylparaben to enable the aforementioned functions to be expressed. In addition, the addition of zirconium silicate can significantly improve not only refractory performance but also the stability of physical strength.

[0048] Preferably, methylparaben and zirconium silicate are mixed in a weight ratio of (60:40) to (90:10).

[0049] In addition, the present invention provides an example in which the carbon fiber among the above compositions is a carbon fiber surface-modified by boron doping.

[0050] By adding surface-modified carbon fibers through boron doping, the refractory performance is doubled and thermal stability is improved even at high temperatures, thereby maintaining physical properties such as the tensile strength of the paste even at high temperatures.

[0051] The boron compounds to be used for the above boron doping may include boric acid (H3BO3), boronic acid (B2O3), boron trifluoride (BF3), etc.

[0052] Various known methods can be applied for such boron doping, including chemical vapor deposition (CVD), high-temperature heat treatment, and solution chemical doping.

[0053] The dual Chemical Vapor Deposition (CVD) method involves converting boron compounds into a gaseous form and reacting them with carbon fibers in a high-temperature reactor to deposit boron atoms onto the fiber surface. This process allows the boron atoms to be integrated into the structure of the carbon fibers.

[0054] Carbon fibers surface-modified by boron doping in this way can be used stably without deformation or degradation even in high-temperature environments, thereby improving thermal stability; in particular, the improved thermal conductivity further enhances fire resistance.

[0055] Preferred embodiments of the present invention are described below by experimental examples.

[0056] <Example 1>

[0057] A sample was prepared by mixing 20 parts by weight of titanium dioxide, 15 parts by weight of aluminum sulfate, 15 parts by weight of magnesium oxide, 15 parts by weight of aerogel (silica aerogel), 10 parts by weight of polyvinyl alcohol, 10 parts by weight of carbon powder, and 5 parts by weight of carbon fiber for every 100 parts by weight of calcium hydroxide.

[0058] <Example 2>

[0059] A sample was prepared by mixing in the same way as in Example 1, but adding a mixture of silica aerogel and alumina aerogel (weight ratio 1:1) as the aerogel.

[0060] <Example 3>

[0061] A sample was prepared by mixing in the same way as in Example 2, but with non-foamed carbon powder added.

[0062] <Example 4>

[0063] A sample was prepared by mixing in the same way as in Example 2, but with an additional 5 parts by weight of methylparaben added to 100 parts by weight of calcium hydroxide.

[0064] <Example 5>

[0065] A sample was prepared by mixing in the same way as in Example 4, but with 1 part by weight of zirconium silicate added to 100 parts by weight of calcium hydroxide.

[0066] <Example 6>

[0067] A sample was prepared by formulating it in the same way as in Example 2, but with carbon fibers that were surface-modified by boron doping added.

[0068] To each of the samples prepared in this way, 23% by weight of resol-type phenolic resin was added relative to the total sample weight and kneaded at room temperature for 30 minutes, and subsequently at 1000 kgf / cm² 2 After pressure molding into a shape of 30×30×160mm under pressure, heat treatment was performed at 180℃ for 20 hours.

[0069] Using each specimen prepared in this manner, the weight loss rate and decarburization layer thickness were measured after firing at 1400°C for 2 hours, and the heating surface temperature was heated to 1200°C for 90 minutes to measure the temperature (°C) of the heating surface and the back surface, and the results are shown in Table 1 below.

[0070] Weight loss rate (%) after firing at 1400℃ for 2 hours Decarburization layer thickness (mm) after firing at 1400℃ for 2 hours Heating surface temperature Rear surface temperature Example 15.9 5.1 116 238 Example 24.9 3.8 116 443 Example 33.5 2.7 116 349 Example 44.3 3.3 116 643 Example 53.1 2.9 116 740 Example 63.2 2.5 116 044

[0071] When comparing Example 1 and Example 2, it can be seen that Example 1 is somewhat more advantageous in terms of thermal insulation effect than Example 2, which is attributed to the fact that silica aerogel is somewhat more advantageous in terms of thermal insulation than alumina aerogel.

[0072] It can be seen that Example 2 is advantageous in terms of fire resistance, which is attributed to the fact that alumina aerogel is more advantageous than silica aerogel in terms of high temperature stability.

[0073] In terms of fire resistance and thermal insulation, the case of Example 2 is somewhat disadvantageous in terms of thermal insulation but much more advantageous in terms of fire resistance, so it is judged that the combined use of silica aerogel and alumina aerogel is more desirable.

[0074] When comparing Example 2 and Example 3, it can be seen that Example 3 is much more advantageous in terms of fire resistance. This is attributed to the fact that, unlike Example 2 where general carbon powder (expanded carbon powder) is applied, Example 3 uses non-expanded carbon powder, which improves fire resistance performance through high thermal conductivity.

[0075] When comparing Example 2 and Example 4, it can be seen that Example 4 is somewhat more advantageous in terms of fire resistance, which is attributed to the addition of methylparaben to Example 4, which improves resistance to thermal degradation.

[0076] Furthermore, it can be seen that the result of Example 5 is more improved than that of Example 4, which is attributed to the addition of zirconium silicate to methylparaben in Example 5, thereby controlling the degradation of methylparaben's function at high temperatures.

[0077] When comparing Example 2 and Example 6, it can be seen that Example 6 is advantageous in terms of fire resistance. This is attributed to the fact that in the case of Example 6, carbon fibers surface-modified by boron doping are applied, which improves thermal stability and, in particular, improves thermal conductivity, thereby further enhancing fire resistance.

[0078] As described above, although the present invention has been explained by limited embodiments and drawings, the present invention is not limited to the above embodiments, and it is obvious that various modifications and variations from the description above may be possible by those skilled in the art to which the present invention belongs.

Claims

1. A refractory composition characterized by comprising calcium hydroxide, titanium dioxide, aluminum sulfate, magnesium oxide, and aerogel.

2. In Paragraph 1, A refractory composition characterized by further including polyvinyl alcohol and carbon fiber.

3. In Paragraph 2, The above aerogel is, A refractory composition characterized by being a silica aerogel.

4. In Paragraph 3, The above aerogel includes, A refractory composition characterized by further including alumina aerogel.

5. In Paragraph 2, A refractory composition characterized by further including carbon powder.

6. In Paragraph 5, A refractory composition characterized in that the above carbon powder is a non-foamed carbon powder.

7. In Paragraph 2, A refractory composition characterized by further including a mixture of methylparaben and zirconium silicate.

8. In Paragraph 2, A refractory composition characterized in that the carbon fiber is a carbon fiber surface-modified by boron doping.