inorganic wool

Abstract

Inorganic wool having a chemical composition containing the following components in weight percentage: 39% to 50% SiO2, 19.5% to 24.0% Al2O3, 8% to 15% CaO, 1% to 5% MgO, 5% to 20% Na2O, 0% to 15% K2O, 2% to 15% Fe2O3, and 0% to 2% B2O3, wherein the mass ratio of MgO / RO is greater than 0.10 and less than 0.50. the mass ratio of RO / (RO+RO) is less than 0.60, the mass ratio of (NaO+MgO) / CaO is greater than 0.8 and less than 1.4, and the mass ratio of (MgO+AlO) / FeO is less than 5.0, where RO represents alkaline earth metal oxides CaO, MgO, BaO, and SrO, and RO represents alkali metal oxides NaO and KO.

Description

[Technical Field]

[0001] The present invention relates to the field of artificial inorganic wool. The present invention is more particularly directed to inorganic wool intended for the production of thermal insulation materials. The present invention particularly relates to inorganic wool for fire protection applications.

[0002] More specifically, the present invention relates to inorganic wools whose chemical composition results in high liquidus temperatures and high flowability at fiberization temperatures, with correspondingly high glass transition temperatures. [Background technology]

[0003] Traditionally, inorganic wools of this type have been fiberized by the so-called "external" centrifugal method, which uses a cascade of centrifugal wheels to which the molten material is supplied by means of a fixed distributor, as described, for example, in particular in EP 0 465 310 or EP 0 439 385.

[0004] The so-called "internal" centrifugal fiberization process, i.e., a process using a high-speed rotating centrifuge with orifices, has so far been limited to fiberization of inorganic wools of the glass wool type, which generally have a composition relatively high in alkali oxides and low in alumina, a lower liquidus temperature, and a higher viscosity at the liquidus temperature than rock wool or basalt wool. This method is described in particular in EP 0 189 354 or EP 0 519 797.

[0005] A technical solution for applying the internal centrifuge method to the fiberization of rock wool is known, in particular from WO 93 / 02977, and is realized by modifying the composition of the materials constituting the centrifuge and its operating parameters. This application makes it possible to combine properties previously unique to either rock wool or glass wool. Thus, rock wool obtained by the internal centrifuge method has a lower proportion of unfiberized material than conventionally obtained rock wool, yet is comparable in quality to glass wool. Nevertheless, it still retains the two advantages associated with its chemical properties: low raw material costs and high temperature resistance.

[0006] In addition to quality standards and industrial and economic feasibility, health criteria are also required: commercial inorganic wool must be biosoluble, i.e., able to dissolve rapidly in a physiological environment, to prevent potential pathogenic risks due to the possibility of very fine fibres being inhaled and accumulating in the body.

[0007] In certain applications, inorganic wools are desirable because of their excellent resistance to very high temperatures. The fire resistance of a structural element corresponds to the period during which the element retains its structural function, ensures fire resistance, and retains its insulating properties. Standard fire resistance tests generally consist of a temperature increase according to the temperature curve for cellulose heating, in accordance with the ISO 834 standard.

[0008] Inorganic wool compositions have been developed that meet the criteria of being fiberizable by internal centrifugation, being biosoluble, and exhibiting excellent high-temperature resistance. Such compositions are described, for example, in WO 2005 / 033032. However, to meet the requirement of very high-temperature resistance, these inorganic fibers must be coated with an organic phosphate-based additive, as described in WO 2006 / 103375.

[0009] WO 2020 / 065191 describes an inorganic wool composition that has improved high-temperature resistance while retaining suitable rheological properties for internal centrifugation. However, it has been found that this composition can undergo significant spinel crystal formation at fiberization temperatures. The presence of these crystals can block the orifices of the fiberizing element, which can affect fiberization efficiency and / or the lifespan of the fiberizing element. Summary of the Invention [Problem to be solved by the invention]

[0010] It is an object of the present invention to provide an inorganic wool composition that can be fiberized in an internal centrifuge and that forms little or no spinel at fiberization temperatures, and that can also be biosoluble and resistant to very high temperatures without the need for organic phosphate additives.

[0011] The progress of fiberization by these methods is such that the molten material 3 The ideal fiberization temperature (T fib ≒T log3 ) must be less than 1220°C. Furthermore, the fiberization temperature (T fib ) and liquidus temperature (T liq ) there must be a sufficient difference between the liquidus temperature (T liq ) must be less than 1185°C. [Means for solving the problem]

[0012] The subject of the present invention is an inorganic wool, which comprises, in percentages by weight, the following components: SiO2 39% to 50%, preferably 39% to 49%, Al2O3 19.5% - 24.0%, preferably 20% - 23%, CaO 8% - 15%, preferably 10% - 14%, MgO 1% - 5%, preferably 2% - 5%, Na2O 5% - 20%, preferably 6% - 18%, K2O 0% - 15%, preferably 1% - 12%, Fe2O3 2% - 15%, preferably 3% - 12%, B2O3 0% - 2%, preferably 0% - 1.5% having a chemical composition containing, where the mass ratio of MgO / RO is greater than 0.10 and less than 0.50, preferably less than 0.40, or even less than 0.30, the mass ratio of RO / (RO + R2O) is less than 0.60, (Na2O + MgO) / CaO mass ratio is greater than 0.8 and less than 1.4, (MgO + Al2O3) / Fe2O3 mass ratio is less than 5.0, where RO represents alkaline earth metal oxides CaO, MgO, BaO, and SrO, and R2O represents alkali metal oxides Na2O and K2O, and it is an inorganic wool.

[0013] By having such a composition, desirable bio - solubility and processing characteristics (T fib ≒T log3 is less than 1220 °C, T liq is less than 1180 °C, T fib -T liq exceeds 35 °C and there is little or no spinel) are maintained, while the resistance characteristics at very high temperatures are significantly improved. The combination of these characteristics is achieved by the combination of magnesia, a relatively low alumina content (less than 24.0%), a clearly defined balance of alkaline earth metal oxides and alkali metal oxides (0.10 < MgO / RO < 0.50, RO / (RO + R2O) < 0.60, and 0.8 < (Na2O + MgO) / CaO < 1.4), and a clearly defined balance of alumina, magnesia, and iron oxide ((MgO + Al2O3) / Fe2O3 < 5.0).

[0014] The present invention also relates to a thermal and / or acoustic insulation product comprising the inorganic wool described above.

[0015] A further subject of the present invention is the use of the above-described inorganic wool in fire-resistant building systems. DETAILED DESCRIPTION OF THE INVENTION

[0016] In the composition according to the invention, the sum of the contents of SiO2, Al2O3, CaO, MgO, Na2O, K2O, Fe2O3 and B2O3 preferably accounts for at least 95% by weight, in particular at least 97% by weight, or even at least 98% by weight of the composition of the inorganic wool.

[0017] The silica (SiO2) content is in the range of 39% to 50%, particularly 49%, or even 48%. If the content exceeds 50%, the biosolubility of the inorganic fibers may decrease. If the content is less than 39%, the viscosity of the composition at the fiberization temperature may be adversely affected.

[0018] The alumina (Al2O3) content is in the range of 19.5% to 24.0%, particularly 20.0%, or even 21% to 23.5%, or even 23.0%. A content greater than 24% may promote spinel formation at the fiberization temperature. A content less than 19.5% may adversely affect the viscosity of the composition at the fiberization temperature.

[0019] The lime (CaO) content is in the range of 8% to 15%, in particular 9%, or even 10%, or even 10.5% to 14%. If the content is less than 8%, the liquidus temperature may increase.

[0020] The magnesia (MgO) content is in the range of 1% (or 1.0%) to 5%, in particular in the range of 1.5%, or even 2% to 4%, or even 3%. MgO contributes to the resistance to very high temperatures. This relatively high MgO content also allows for the incorporation of more recycled materials from inorganic wool waste, for example demolition waste, especially containing rock wool.

[0021] Inorganic wools generally do not contain alkaline earth metal oxides other than CaO and MgO, but may still contain small amounts of BaO or SrO, the respective contents of which may range up to 2%, indeed even up to 1%, 0.20%, or even 0.1%, and these oxides may be present as impurities in certain raw materials.

[0022] The ratio of magnesium oxide to the sum of alkaline earth metal oxides RO (CaO, MgO, BaO, and SrO), i.e., MgO / RO, is greater than 0.10 and less than 0.50, in particular 0.11, or even 0.12 to 0.40, or even 0.38, 0.35, or even 0.30. If the MgO / RO ratio is less than 0.10, it may affect the resistance to very high temperatures. On the other hand, if the MgO / RO ratio is greater than 0.50, the liquidus temperature may increase.

[0023] The total content of alkali metal oxides (RO), in particular sodium oxide (NaO) and potassium oxide (KO), is preferably greater than 12%. The NaO content is in the range of 5% to 20%, in particular 6%, or 7% to 18%, or even 15%, or 12%. The KO content is at most 15%, in particular 1%, or even 2% to 12%, or even 10%, 8%, 5%, or 4%. The inorganic wool preferably does not contain alkali metal oxides other than NaO and KO. Nevertheless, the inorganic wool may contain small amounts of LiO, which is sometimes present as an impurity in certain raw materials and whose content may range up to 0.5%, indeed even 0.2%, or even 0.1%.

[0024] The RO / (RO+RO) ratio is less than 0.60, in particular 0.15, or even 0.20, or 0.30 to 0.59, or even 0.58. If the RO / (RO+RO) ratio is greater than 0.60, the fiberizability of the composition may be affected.

[0025] The (Na2O+MgO) / CaO ratio is greater than 0.80 and less than 1.4, or even less than 1.3. A (Na2O+MgO) / CaO ratio less than 0.80 may affect the properties of resistance to very high temperatures, while a (Na2O+MgO) / CaO ratio greater than 1.4 may affect the fiberizability of the composition.

[0026] The iron oxide (Fe2O3) content is in the range of 2% to 15%, in particular 3%, or even 4%, or 4.5% to 12%, or even 10%, or 8%. Expressing the (total) iron oxide content as Fe2O3 does not necessarily mean that this iron oxide is present in the glass only in trivalent form. Although glasses generally contain iron oxide in both trivalent (Fe2O3) and divalent (FeO) forms, the total iron oxide content is conventionally referred to as Fe2O3. Iron oxide has a positive effect on the high-temperature performance of inorganic wools.

[0027] The (MgO+Al2O3) / Fe2O3 ratio is less than 5.0, in particular 2.0, or even 3.0 to 5.0. Ratios greater than 5.0 may favor spinel formation at drawing temperatures and / or may affect resistance to very high temperatures.

[0028] The content of boron oxide (BO) is at most 2%, in particular 0.1%, indeed even 0.5% to 1.5%, or even 1%. The presence of boron can be advantageous for improving the biosolubility of the fiber and / or enhancing its barrier properties. In some embodiments, the composition contains less than 1% BO.

[0029] The inorganic fiber compositions according to the invention may also contain P2O5, particularly in amounts up to 3%, and indeed even up to 1.2%, to enhance biosolubility at neutral pH, but preferably the inorganic fiber compositions according to the invention are substantially free of P2O5, although up to 0.5% may be present as an impurity.

[0030] The composition according to the invention may also contain other elements, particularly those present as unavoidable impurities. The composition according to the invention may contain titanium oxide (TiO2) and zirconia (ZrO2), each in a content of up to 3%, particularly 0.1% to 2.0%, and even 1.0%. The composition is preferably substantially free of halogens, particularly fluorine. The composition usually contains less than 1%, or even less than 0.5%, of halogens, particularly fluorine.

[0031] It is clear that the various preferred ranges above may be freely combined with one another, although for the sake of brevity it is not possible to list all the various combinations.

[0032] According to one preferred embodiment, the inorganic fibers according to the invention comprise the following components in weight percentage: SiO2 39%~48%, Al2O3 20% to 23%, preferably 21% to 23%, CaO 10% to 14%, MgO 2% to 4%, Na2O 7%~15%, K2O 2%~8%, Fe2O3 3%~8%, B2O30%~1%, wherein: the mass ratio of MgO / RO is greater than 0.10 and less than 0.50, preferably less than 0.40, or even less than 0.30; the mass ratio of RO / (RO+RO) is less than 0.60; The mass ratio of (Na2O+MgO) / CaO is greater than 0.8 and less than 1.4, The mass ratio of (MgO+Al2O3) / Fe2O3 is less than 5.0.

[0033] Another subject of the present invention is a method for obtaining the inorganic fibers according to the invention, comprising the steps of melting a vitrifiable mixture having substantially the same chemical composition as said inorganic fibers, and then carrying out fiberization, in particular by the internal centrifuge method.

[0034] The melting process can produce a bath of molten material from a vitrifiable mixture, which can include a variety of natural and / or artificial base materials, such as silica sand, phonolite, dolomite, sodium carbonate, etc.

[0035] The melting step can be carried out in various known ways, in particular by melting in a fuel-fired furnace or by electromelting.

[0036] A fuel-fired furnace comprises at least one burner, which may be of the submerged type (where the flame is positioned above the bath of molten material and heats the bath by radiation) or of the immersed type (where the flame is generated directly within the bath of molten material). The or each burner may be supplied with a variety of fuels, such as natural gas or fuel oil.

[0037] "Electric melting" should be understood to mean immersing an electrode in a bath of molten material and melting the vitrifiable mixture by the Joule effect; other heating means, such as a flame, are excluded. The vitrifiable mixture is usually distributed evenly over the surface of the bath of molten material using a mechanical device, thereby forming a heat shield. This heat shield limits the temperature above the bath of molten material, so that the presence of a superstructure is not necessary. The electrode can be suspended from above so that it is immersed in the bath of molten material, or it can be installed at the bottom or on the side wall of the tank. The first two options are generally preferred for large tanks, as they achieve the best possible distribution of heating of the bath of molten material. The electrode is preferably made of molybdenum, and in fact may even be made of tin oxide or graphite. The molybdenum electrode penetrates the bottom through a water-cooled electrode holder, preferably made of steel.

[0038] The melting process may also use both fuel combustion melting and electrical melting, for example, by using a fuel-fired furnace with electrodes on the side walls, which is used to accelerate the melting of the vitrifiable mixture.

[0039] The fiberization step is preferably carried out by internal centrifugation.

[0040] The resulting fibers can be bonded with a sizing composition sprayed onto the surface, and then packaged and shaped into various inorganic wool products such as rolls or panels. Preferably, such bonded inorganic wool products contain up to 15% by dry weight of binder, based on the combined weight of binder and inorganic fibers.

[0041] To achieve even better fire resistance, the inorganic wool can contain a phosphorus-based additive, which is preferably sprayed simultaneously with the sizing composition. The phosphorus-based additive can be an inorganic additive as described in WO 01 / 68546, or it can be a phosphate-based organic additive, such as a poly(phosphonic acid, or phosphoric acid, or phosphonic acid ester, or phosphate ester) type oligomer or polymer, as taught in WO 2006 / 103375. However, the inorganic wool composition according to the present invention has the advantage of inherently possessing very good resistance properties at very high temperatures. The use of a phosphorus-based additive further improves performance. However, even for certain highly demanding applications requiring fire retardancy, the use of such phosphorus-based compounds is unnecessary. In some embodiments, the inorganic wool does not contain a phosphorus-based additive.

[0042] Another subject of the present invention is a thermal insulation product comprising inorganic fibers according to the present invention. The thermal insulation product comprising inorganic fibers according to the present invention is particularly provided in the form of a roll or panel. The thermal insulation product comprising inorganic fibers according to the present invention can be used, for example, in buildings, industry, or transportation, especially railways or ships. The thermal insulation product comprising inorganic fibers according to the present invention is particularly suitable for applications where there may be continuous exposure to high temperatures (insulation of domestic or industrial ovens or stoves, or insulation of pipes for transporting fluids), or where there may be exposure to high temperatures in emergency fire protection (fire doors, boat insulation, tunnel insulation, insulation of offshore platforms, etc.). More generally, the product according to the present invention can be used for thermal insulation of all types of buildings, tertiary industry buildings, or residential facilities (apartments or individual houses). The product according to the present invention can be used, for example, in external insulation systems for insulating wooden houses, sandwich panels, ventilation ducts, etc.

[0043] A further object of the present invention is the use of the above inorganic wool in fire-resistant building systems.

[0044] The term "fire-resistant building system" refers to a system collectively comprising an assembly of materials, particularly inorganic wool and metal sheets, that can effectively retard the spread of heat during a fire, provide protection from flames and hot gases, and retain mechanical strength.

[0045] Standardized tests define the degree of fire resistance, expressed as the time it takes to reach a given temperature on the other side of a building system when exposed to a heat flux, for example from a burner flame or an electric furnace.

[0046] A building system is considered to have satisfactory fire resistance performance if it is considered to meet the requirements of, among other things, one of the following tests: - Fire door test: Test on mineral fibre boards according to German standard DIN 18 089 Part 1 (or equivalent). - the fire behavior of building materials and components as specified in German standard DIN 4102 (or equivalent), in particular DIN 4102 Part 5 for full-scale tests to determine the fire resistance class and / or DIN 4102 Part 8 for testing of specimens using small test equipment. - Tested in accordance with standard test IMO A.754(18) (or equivalent) which describes general fire test requirements for marine applications, including ship bulkheads. These tests are carried out on large specimens in an oven measuring 3m x 3m. An example is a steel bridge which must perform to a thermal insulation standard for at least 60 minutes on the insulated side in the event of a fire.

[0047] The following examples illustrate the invention without limiting it.

[0048] Example

[0049] Examples of glasses (Example 1 according to the invention, and Comparative Examples C1 to C5) were prepared, the compositions of which (wt %) are shown in Table 1.

[0050] The composition is determined by the fiberization temperature (T fib ≒T log3) is less than 1220°C, and the liquidus temperature T liq is less than 1180°C and T fib -T liq A fiber is considered to have satisfactory fiberizability properties ("good"), especially for the internal centrifugal drawing process, if the fiberizability range of the fiber is above 35°C. In contrast, if any of these conditions is not met, the fiberizability properties are not satisfactory ("poor").

[0051] The shrinkage is determined by thermomechanical analysis. The resulting glasses were powdered to a particle size of less than 40 μm. Each glass powder was compressed into a cylindrical pellet with a diameter of 5 mm, a height of approximately 1 cm, and a density of 64% of the glass density. The shrinkage, expressed as a percentage, corresponds to the change in height of the glass powder pellet relative to its initial height when subjected to a gradient of 10 K / min from ambient temperature to 1100 °C. The height of the sample is measured using a probe placed on the top of the cylinder. Repeated tests allow a standard deviation of less than 1% to be determined. A shrinkage of less than 12% is considered satisfactory for achieving the desired cellulose fire resistance ("good"). On the other hand, a shrinkage of more than 12% indicates unsatisfactory resistance to the cellulose heating curve ("poor").

[0052] The presence of spinel is determined by microscopic analysis. The resulting glass is powdered to a particle size range of 815 μm to 2 mm. log3 +50℃~T log3 Annealing is performed at temperatures in the range of -50° C. Thin sections of the annealed glass are prepared and characterized for the presence of spinel crystals by observing them under an optical or electron microscope.

[0053] [Table 1]

[0054] The composition of Example 1 according to the present invention maintains a low shrinkage of less than 12% up to 1100°C, indicating good resistance to very high temperatures. log3 The temperature is less than 1220°C and T liq Since the temperature is below 1180°C and the fiberization range is above 35°C, this allows for internal centrifugal fiberization without the risk of devitrification. Furthermore, spinel is not formed at the fiberization temperature, which could affect the fiberization efficiency and / or the lifespan of the fiberization element. In contrast, the compositions of comparative examples C1 to C6 cannot meet all of these criteria. Compositions C1, C2, C3, C6, and C7 do not have sufficient resistance to very high temperatures. In particular, composition C6 shows collapse upon shrinkage after 1000°C, and at 1100°C, the shrinkage reaches more than 20%. Compositions C1 and C4 are particularly suitable for T liq The composition C5 and C7 do not show satisfactory fiberization properties, since the temperature is too high and fiberization by the internal centrifuge is not possible. Finally, the formation of spinel is observed at the fiberization temperature for compositions C5 and C7.

Claims

1. 1. An inorganic wool comprising, in weight percentage, the following components: Yes ２ 39% to 50%, Al ２ O ３ 19.5%~24.0%、 CaO 8% to 15%, MgO 1% to 5%, Na ２ O5%~20%、 K ２ O 0%~15%, Fe ２ O ３ 2%~15%、 B ２ O ３ 0%~2% wherein: the mass ratio of MgO / RO is greater than 0.10 and less than 0.50; RO / (RO+R ２ O) is less than 0.60 by mass; (Na ２ the mass ratio of (MgO+MgO) / CaO is greater than 0.8 and less than 1.4; (MgO + Al ２ O ３ ) / Fe ２ O ３ is less than 5.0 by mass ratio, Here, RO represents alkaline earth metal oxides CaO, MgO, BaO and SrO, and R ２ O is alkali metal oxide Na ２ O and K ２ O stands for inorganic wool.

2. R ２ 2. The inorganic wool according to claim 1, characterized in that the O content is greater than 12%.

3. Inorganic wool according to claim 1 or 2, characterized in that the composition contains 0% to 0.20% BaO.

4. The inorganic wool is 39% to 48% SiO ２ The inorganic wool according to any one of claims 1 to 3, characterized in that it contains:

5. The inorganic wool contains 20% to 23% Al ２ O ３ The inorganic wool according to any one of claims 1 to 4, characterized in that it contains:

6. Inorganic wool according to any one of claims 1 to 5, characterized in that the inorganic wool contains a CaO content of between 10% and 14%.

7. Inorganic wool according to any one of claims 1 to 6, characterized in that the inorganic wool contains an MgO content of between 2% and 4%.

8. The inorganic wool is 7% to 12% Na ２ Inorganic wool according to any one of claims 1 to 7, characterized in that it contains an O content.

9. The inorganic wool contains 2% to 5% K ２ Inorganic wool according to any one of claims 1 to 8, characterized in that it contains an O content.

10. The inorganic wool contains 4.5% to 8% Fe ２ O ３ The inorganic wool according to any one of claims 1 to 9, characterized in that it contains:

11. A thermal and / or acoustic insulation product comprising the inorganic wool of any one of claims 1 to 10.

12. Use of the inorganic wool according to any one of claims 1 to 10 in fire-resistant building systems or in insulation products for use at high temperatures.

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