Blown mineral wool and its use

Abstract

The present invention relates to a blown mineral wool, free of organic binders, comprising glass fibers coated with at least one monomeric acid having a boiling point of at least 135 °C and at least one silicone, as well as its manufacturing process. It also relates to the use of this mineral wool as thermal insulation for a structure, in which the mineral wool is blown into a cavity or onto a surface of said structure.

Description

Title of the invention: Blown mineral wool and its use FIELD OF INVENTION

[0001] The present invention relates to a blown mineral wool, free of organic binder, comprising glass fibers coated with at least one monomeric acid having a boiling point of at least 135 °C and at least one silicone, as well as its manufacturing process. It also relates to the use of this mineral wool as thermal insulation for a structure, in which the mineral wool is blown into a cavity or onto a surface of said structure. STATE OF THE ART

[0002] It is known to provide thermal and / or acoustic insulation to a building surface, for example a wall, floor, or subfloor, by blowing glass wool directly onto the surface. This solution is particularly suitable for insulating attics, hard-to-reach areas, or walls with irregular shapes, where glass wool batts cannot be used. Blown glass wool typically consists of short glass fibers without a binder, unlike the glass wool used in insulating batts. It is supplied loose in bags, where it is generally compressed to approximately 150 kg / m³. It undergoes initial expansion when the bag is opened and is then fed into a device configured for blowing the glass wool, such as a carding machine, where the glass wool undergoes a second expansion.The glass wool is then transported in a pneumatic tube from the carding machine to the wall to be insulated.

[0003] An important property of blown wool is its expansion capacity, which also affects its thermal properties. However, when stored in a humid environment, glass wool is susceptible to compaction due to chemical interactions between the water and the glass surface (particularly with hygroscopic carbonates), and between the glass fibers themselves. To counteract this phenomenon, it is known to apply a silicone emulsion to the glass fibers, which makes the glass surface hydrophobic and improves inter-fiber lubrication (US2019 / 315935; US2023 / 002275). This emulsion is generally sprayed onto the freshly formed glass fibers at the centrifugal spinning crown, and the fibers are then collected on a conveyor belt and dried.The breaking down of the silicone emulsion, allowing the silicone to spread onto the glass fibers, is achieved in a later step, through contact with air heated typically to 140-220 °C. The dry mat is then ground into flakes and then... possibly treated with an antistatic additive, then with an anti-dust additive, before being bagged.

[0004] However, it has been observed that when the surface of the glass comes into contact with water, mobile ions such as alkali or alkaline earth ions can be extracted and form metal hydroxides, leading to a local increase in pH. This, in turn, can cause depolymerization of the silicone, resulting in the emission of volatile organic compounds (cyclosiloxanes) and a loss of hydrophobicity in the glass, which thus becomes more sensitive to water. A vicious cycle is thus established, culminating in the compaction phenomena that silicone was supposed to prevent. Furthermore, the metal ions extracted from the glass are capable of reacting with carbon dioxide present in the ambient air to form carbonates, which appear as crystals on the surface of the glass fibers. Crystals of different morphologies can thus be observed under a scanning electron microscope, corresponding to different carbonates.These crystals serve as a marker of the glass corrosion phenomena described previously.

[0005] Among the solutions proposed so far to counteract this compaction phenomenon, US patent 10,876,286 suggests applying a reactive silicone downstream of the mill, i.e., at the end of the process. Another solution proposed in US patent 6,562,257 consists of applying a "blocking additive" to the newly formed glass fibers. This additive can comprise various chemical functionalities capable of interacting (via covalent, Van der Waals, or hydrogen bonds) with the hydroxyl groups present on the glass surface. These functionalities are selected from alcohols, esters, or amides. These compounds would prevent these hydroxyl groups from interacting with water. More specifically, they are modified silanes, such as aminosilanes.

[0006] For its part, US patent 2023 / 002275 suggests adding an acid such as acetic acid to an amino silicone emulsion in order to lower its pH to the range of 4 to 6 and thus improve the quality and speed of the silicone coating on the glass. Acetic acid has a sufficiently low boiling point to be eliminated when the glass wool is heated and is therefore no longer present on the blown-in wool. Consequently, it does not maintain the hydrophobic character of the amino silicone during the storage of the insulation products and therefore does not contribute to protecting the blown-in wool from moisture.

[0007] After much research, the inventors have developed a new solution to the aforementioned problems, which makes it possible to protect the surface of glass fibers from moisture and thus avoid the problems of compaction of insulating materials based on blown wool and emission of volatile organic compounds. Description of the invention

[0008] The present invention thus relates to a mineral wool without organic binder, comprising glass fibers coated with at least one monomeric acid having a boiling point of at least 135 °C and at least one silicone.

[0009] The present invention also relates to a method for manufacturing blown wool, comprising: - the transformation of molten glass into fibers, - the application to the fibers of at least one monomeric acid having a boiling point of at least 135 °C and at least one silicone, contained in one or more compositions, each free of compounds capable of polymerizing with each other and / or with the acid, - the collection of the fibers, - the grinding of the fibers, - possibly, the treatment of the ground fibers using at least one antistatic additive and / or at least one dust-suppressing additive, - the conditioning of the crushed fibers, possibly treated.

[0010] The invention further relates to the use of this mineral wool as thermal insulation for a structure, in which the mineral wool is blown into a cavity or onto a surface of said structure.

[0011] It also relates to the use of a monomeric acid having a boiling point of at least 135°C to protect blown wool, comprising silicone-coated glass fibers, against moisture, in particular to prevent or reduce corrosion of the glass and / or compaction of the glass wool and / or the emission of volatile organic compounds, in particular cyclosiloxanes.

[0012] The invention further relates to a method for protecting blown wool, comprising silicone-coated glass fibers, against moisture, in particular to prevent or reduce corrosion of the glass and / or compaction of the glass wool and / or emission of volatile organic compounds, in particular cyclosiloxanes, comprising the application to the glass fibers of at least one monomeric acid having a boiling point of at least 135°C. DESCRIPTION OF THE FIGURES

[0013] Other features, objectives and advantages of the invention will become apparent from the following description, taken in combination with the accompanying drawings in which:

[0014] Fig. 1 illustrates a fiberglass production installation that can be used in the manufacture of blown wool according to the invention.

[0015] Fig. 2 is a scanning electron microscopy image, showing reference glass fibers after aging in a humid environment.

[0016] Fig. 3 is a scanning electron microscopy image, showing glass fibers treated with citric acid, after aging in a humid environment.

[0017] Fig. 4 is a scanning electron microscopy image, showing glass fibers treated with sulfamic acid, after aging in a humid environment. DETAILED DESCRIPTION OF THE INVENTION

[0018] In the remainder of this description, the expression "between" should be understood as defining a range of values ​​including the bounds mentioned.

[0019] The invention relates to a blown mineral wool. By "blown wool" is meant a mineral wool based on an entanglement of glass fibers, which is adapted to be transported by an airflow and in particular to be subjected to a blowing process as defined by standard EN 14064-1:2007, and preferably defined by the document "Technical Notebook 8, Preparation of test specimens for bulk products, Revision Index C, date of implementation: 01 / 07 / 2019, ACERMI", referring to Annex C.2.1 of standard EN 14064-1:2007.

[0020] Blown wool differs from a glass wool mattress in that it is devoid of an organic binder. By "organic binder" is meant a thermosetting resin capable of binding the glass fibers together and which may in particular be: (a) a phenolic resin (in particular of the resol type), (b) a polyester resin obtained from reagents consisting of at least one carbohydrate and / or polyol and at least one polycarboxylic organic acid, (c) the products of the addition / elimination of anhydrides of aliphatic and / or aromatic polycarboxylic acids with alkanolamines, (d) the products of the Maillard reaction between a reducing sugar and a nitrogenous compound.

[0021] The mineral wool according to the invention comprises glass fibers coated with at least one silicone and at least one monomeric acid having a boiling point of at least 135 °C. These constituents will now be described in more detail. Fiberglass

[0022] Glass fibers can be made of borosilicates, aluminosilicates or aluminoborosilicates.

[0023] Preferably, the glass fibers can be produced by melting a glass having: - a SiO2 mass content between 50% and 75%, and preferably between 60% and 70%, and / or

[0024] - a mass concentration of Na2O between 10% and 25%, and preferably between between 10% and 20%, and / or

[0025] - a mass fraction of CaO between 5% and 15%, and preferably between 5% and 10%, and / or

[0026] - a mass percentage of MgO between 1% and 10%, and preferably between 2% and 5%, and / or - a sum of a mass percentage of CaO and a mass percentage of MgO between 5% and 20%, and / or

[0027] - a mass concentration of B2O3 between 0% and 10%, in particular between 2% and 8%, preferably between 3% and 7%, and more preferably between 4% and 6%; and / or

[0028] - a mass percentage of Al₂O₃ between 0% and 8%, and preferably between 1% and 6%, and / or

[0029] - a mass percentage of K2O between 0% and 5%, and preferably between 0.5% and 2%, and / or

[0030] - a sum of a mass percentage of Na2O and a mass percentage of K2O including between 12% and 20%.

[0031] In one embodiment of the invention, the fibers have a population distribution of fiber lengths such that the ratio between the fiber length equal to the 90th percentile in number of the distribution and between the median fiber length in number of the distribution is greater than 3, in particular greater than 4, and preferably greater than 5. Indeed, when a coating formed by the blown product has both a significant proportion of short and long fibers, it is possible to retain certain fibers that cause dust emission during the application of the coating and to minimize the thermal conductivity compared to a coating comprising only long fibers.

[0032] The average length of the number of fibers in the distribution can be between 0.5 mm and 1.5 mm.

[0033] The fiber length equal to the 90th percentile in number of the distribution may be strictly greater than 1 mm, in particular strictly greater than 1.5 mm and preferably strictly greater than 2.0 mm.

[0034] The median number fiber length of the distribution may be less than or equal to 2 mm, in particular less than 1 mm and preferably between 300 pm and 700 pm.

[0035] Glass fibers can have a fineness between 4 L / min and 9 L / min.

[0036] In the present application, the fineness of the glass fibers is determined by the The value of their micronaire under 5 g, expressed in L / min. The micronaire, also called the "fineness index," represents the specific surface area of ​​the fibers. Micronaire measurement includes measuring the aerodynamic pressure drop when a given quantity of fibers extracted from an insulating product is subjected to a given pressure from a gas, generally air or nitrogen. This measurement is common in mineral fiber production units and is standardized (DIN 53941 or ASTM D 1448) and it uses a device called a "micronaire apparatus". The method for measuring the micronaire is also described in document WO 2003 / 098209. The volume-weighted median diameter of the fibers can be between 5 pm and 15 pm, preferably between 7 pm and 11 pm.

[0037] The diameter and length of the fibers can be measured by depositing the fibers on a substrate and then imaging the deposited fibers with a microscope. A sample of the product or coating can be taken using forceps. Typically, between 10 and 30 mg of the product or coating can be taken. The number of fibers measured is greater than 1000, in particular greater than 2000, and preferably greater than 5000. The fibers in the sample can then be dispersed in a solvent. The solvent may comprise a mixture of distilled water and glycerin, for example in a 500:1 ratio, and / or include a surfactant. The sample is stirred using a laboratory stirrer for between 30 minutes and 2 hours, resulting in the dispersion of the fibers in the solvent. The fiber dispersion is then diluted in distilled water at a ratio of 1:3 to 1:20.The diluted fiber dispersion is then deposited onto a substrate, for example, the bottom of a Petri dish. The fibers within the dispersion are then imaged using a microscope with an objective offering a magnification of, for example, 20X, 40X, or 90X, or any other imaging system (camera, scanner) capable of observing the fibers at a resolution sufficient to determine their length. Image processing is then performed. In each image, pixel clusters smaller than a few pixels or with an eccentricity less than 0.5—that is, particles with a roughly circular shape—are excluded. Skeletonization is then applied to each image to obtain the fiber mid-axis. Finally, a scoring function is used to evaluate the probability that two fiber segments belong to the same fiber.The scoring function is also used to reconstruct fibers that were broken into fiber segments during the thresholding step. Silicone

[0038] The silicone can be chosen from organopolysiloxanes such as polydimethylsiloxanes, polymethylsiloxanes, polyphenylmethylsiloxanes, poly(2-phenylpropylmethyl)siloxanes and phenylsiloxanes, which can optionally be functionalized.

[0039] Examples of functionalized (or reactive) silicones are OH-terminated polydimethylsiloxanes; H-terminated polydimethylsiloxanes; amine polydimethylsiloxanes, having, for example, an amine number between 0.05 and 0.40 (as measured according to DIN 53176), in particular poly(3- aminopropylmethyl)siloxanes, poly(aminoethylaminopropylmethoxy)siloxanes; or alkoxylated polydimethylsiloxanes; and mixtures thereof.

[0040] Examples of non-functionalized (or non-reactive) silicones are trimethylsiloxanes.

[0041] These silicones are generally available commercially in the form of emulsions, for example from WACKER under the trade names SILRES® BS 1042, SILRES® BS 1052 or SILRES® BS1340 or from DOW CORNING under the names DC 346, DC1171, DC75SF or DC2-7887. These emulsions contain, in addition to silicone, water and possibly one or more surfactants.

[0042] According to the invention, it is preferable to use a polydimethylsiloxane with a trimethylsilyl or OH termination.

[0043] Silicone can represent from 0.05% to 0.4% and preferably from 0.1% to 0.3% of the weight of the mineral wool according to the invention. Acid

[0044] The monomeric acid used according to the invention has a boiling point of at least 135 °C. In a particular embodiment, the boiling point of the acid is at least 140 °C, preferably at least 150 °C, more preferably at least 160 °C or even at least 170 °C, and advantageously less than 300 °C. In addition, it may comprise one or more acidic functional groups and may have at least a pKa at 25 °C greater than -1.74 and more preferably greater than 0. In particular, it may be selected from organic or inorganic acids, especially organic acids containing at least one carboxylic acid functional group and inorganic acids containing at least one sulfonic acid functional group, as well as mixtures thereof. It is preferably selected from citric acid, sulfamic acid, malic acid, and mixtures thereof; It is more preferably citric acid or sulfamic acid, better yet, citric acid.

[0045] In one embodiment of the invention, the quantity of acid ranges from 0.1 to 0.8%, preferably from 0.2 to 0.6% and more preferably from 0.2 to 0.5% by weight, relative to the weight of the glass fibers. Manufacturing process

[0046] The process for manufacturing mineral wool according to the invention includes a first step of transforming molten glass into fibers.

[0047] This step can be implemented in a production installation as illustrated in [Fig. 1], comprising a fiber-pulling unit equipped with a centrifugal device 1 configured to rotate about a vertical axis X. The centrifugal device 1 has a peripheral band. The peripheral band (or The plate is perforated with a plurality of orifices through which the molten raw material can flow from the inside of the centrifugation device to the outside, forming filaments of molten raw material. The fiber-forming unit may also include a burner 2. The burner 2 may be annular in shape and arranged to impose a controlled-temperature gas flow from the orifices. The burner 2 stretches the filaments exiting the orifices to form glass fibers. An annular inductor 3 may be arranged below the centrifugation device. The annular inductor 3 heats a lower part of the centrifugation device 1, in particular the plate. A receiving mat 5 is generally arranged below the centrifugation device 1 and collects the glass fibers in the form of mats 4.

[0048] According to the invention, one or more compositions, free of compounds capable of polymerizing with each other and / or with the acid, are applied to the fibers, typically sprayed onto the fibers via a ring equipped with nozzles (not shown) arranged between the annular inductor 3 and the conveyor belt 5. This may be a single composition comprising at least one monomeric acid having a boiling point of at least 135 °C and at least one silicone, or two separate compositions, each containing one of these constituents. These two compounds are thus applied separately or simultaneously to the fibers. In practice, a single composition is preferred. The silicone is typically applied to the fibers in the form of an emulsion which, under the temperature conditions of the fiber-laying unit (i.e., a temperature of approximately 180–210 °C at the fiber-laying floor), is capable of breaking down to form a substantially homogeneous silicone layer on the glass fibers.The presence of water in the silicone emulsion also helps to cool the hot glass fibers.

[0049] After collection on the conveyor belt 5, the fibers are ground, for example by means of a rotary grinder or a cutting grid, in order to reduce the mattress into flakes.

[0050] Glass fibers can be treated with at least one antistatic additive and / or at least one dust-suppressing additive.

[0051] These additives can be sprayed onto the glass fiber mat 4 produced following the glass fiber mat 4 formation step described above and / or following the fiber grinding step, for example during the transport of the fibers in a pneumatic channel.

[0052] The antistatic additive may, for example, be selected from: an ammonium salt, polyethylene glycol, and mixtures thereof. The mass percentage of the antistatic additive may be between 0.01% and 0.30%, in particular between 0.02% and 0.20%, and preferably between 0.05% and 0.15%, relative to the weight of the coated fibers. Preferably, the antistatic additive comprises polyethylene glycol and at least A compound selected from an ammonium salt such as ammonium chloride and / or ammonium sulfate. The total mass percentage of the ammonium salt may be between 0.01% and 0.25%, in particular between 0.01% and 0.05%. The mass percentage of polyethylene glycol may be between 0.03% and 0.20%, in particular between 0.05% and 0.10%. These mass percentages are defined relative to the total mass of mineral wool.

[0053] The dust-suppressing additive reduces dust formation during the blowing of the blown-in wool, thereby increasing user comfort and preventing the penetration of glass fibers into the user's respiratory tract. It may comprise an oil, in particular a vegetable oil and / or a mineral oil, which may also reduce inter-fiber attrition during the application of the glass wool. The dust-suppressing additive may be formulated in water in the presence of a small amount of surfactant such as a mono-, di-, or triester of fatty acid. Preferably, the mass concentration of the dust-suppressing additive in the mineral wool according to the invention may be between 0.01% and 1.5%, preferably between 0.2% and 0.5%.

[0054] Generally, it is preferred that the mineral wool according to the invention have a mass percentage of the total additive(s) between 0.4% and 1.7%, in particular between 0.6% and 1.2%, and preferably between 0.7% and 0.9%. This maximizes the thermal insulation capacity of the product while limiting dust emissions during installation. Indeed, additives, which typically include organic compounds, promote heat transfer through the product and thus degrade the thermal insulation properties of the blown-in product.

[0055] The mass percentage of the total additive(s) can be determined by a loss on ignition measurement, in accordance with ISO 1887:2014.

[0056] In one embodiment of the invention, the process according to the invention may include an oven-drying step of the glass wool mattress, typically at a temperature of 135-170 °C (i.e., a core temperature of about 120 to 140 °C).

[0057] In all cases, in the process according to the invention, it is preferable that the fibers be dried at an ambient temperature of 135 to 220 °C, preferably 150 to 210 °C, before or after the collection step, for a period of time ranging, for example, from 5 seconds to 10 minutes, in particular from 10 seconds to 5 minutes.

[0058] The fibers are then packaged, typically in bags, and compressed with a compression ratio of at least 10:1 in general. The density of the compressed and bagged mineral wool can thus be between 100 kg / m³ and 180 kg / m³, in particular between 120 kg / m³ and 160 kg / m³. After expansion and blowing, the mineral wool according to the invention can have a density of between 5 kg / m³ and 18 kg / m³ (in open air supply) or between 25 kg / m³ and 35 kg / m³ (in a cavity). Furthermore, it is preferable that its expansion rate, as measured according to the method described in Example 4, be greater than 150%, and preferably greater than 200%, or even greater than 230%, after 6 months of bagged storage. Uses

[0059] The mineral wool according to the invention can be used as thermal insulation for a structure. To do this, the mineral wool is blown into a cavity or onto a surface of said structure, which may in particular be a part of a floor, ceiling or wall, for example in an air gap behind a brick wall or behind a wooden frame or in prefabricated boxes.

[0060] Any insulating product blowing device known to those skilled in the art can be used for this purpose. These blowing devices typically comprise a hopper into which the mineral wool is poured, a carding or clumping system to separate the wool, and a pneumatic system adapted to convey the carded wool to a distribution pipe. This pipe allows the mineral wool to be applied to the desired surfaces or into the cavities. Machines of this type are available, in particular, from the company SAINT-GOBAIN ISOVER.

[0061] The following examples are given for illustrative purposes only and are not intended to limit the scope of this invention. EXAMPLES

[0062] Example 1: Preparation of blowing wools

[0063] 5.32 kg of silicone emulsion (BS 1042® from SILRES) was mixed with 7.36 kg or 14.72 kg of acid (citric or sulfamic acid), and water in sufficient quantity to obtain 336 kg of additive composition.

[0064] These compositions were sprayed onto freshly formed glass fibers, exhibiting a micronaire of 8.5 to 9 L / min, in the following quantities:

[0065] [Tables 1] Composition Acid % mass on fibers AC0.3 Citric 0.3% AC0.6 Citric 0.6% AS0.3 Sulfamic 0.3% AS0.6 Sulfamic 0.6%

[0066] A comparative acid-free composition (Ref) was also prepared and applied to the fibers.

[0067] The fibers were then collected. Before and / or after collection, they were dried at an ambient temperature of 170–180 °C. The fibers were then shredded and conveyed to a bagging device. During pneumatic conveying, an antistatic composition and then a dust-suppressant additive were successively sprayed onto the fibers. The antistatic composition contained 4.7% by dry weight of antistatic agent and 16.5% by dry weight of polyethylene glycol in water and was added in sufficient quantity to obtain an antistatic coating representing 0.06% of the weight of the coated fibers. The dust-suppressant additive consisted of a mineral oil.

[0068] Four products according to the invention were thus obtained, respectively designated by LAC0.3, LAC0.6, LAS0.3 and LAS0.6, as well as a reference product (LRef), obtained from the comparative composition.

[0069] Example 2: Visual observation

[0070] The blowing wools LRef, LAC0.3, and LAS0.3 obtained in Example 1 were observed under a scanning electron microscope before and after artificial aging (1 week at 50 °C and 90% relative humidity). As shown in the accompanying figures, the reference product exhibits signs of corrosion on its glass fibers ([Fig. 2]), unlike products LAC0.3 and LAS0.3 (Figures 3 and 4, respectively). [Fig. 2] shows calcium carbonate grains on the reference product, as well as droplet-like structures of varying sizes corresponding to additive droplets. These calcium carbonate grains are absent, or present only in very small quantities, on the products according to the invention.

[0071] Example 3: Measurement of water absorption

[0072] The water absorption by the insulating products prepared in Example 1 was evaluated according to standard EN 1609.

[0073] The results of these tests are summarized in the Table below.

[0074] [Tables2] Time (days) Water absorption (kg / m2) LRef LAS0.3 LAS0.6 LAC0.3 LAC0.6 90 0.08 0.02 0.025 0.015 0.03 194 0.075 0.045 0.045 0.025 0.035

[0075] As can be seen from this table, all values ​​are less than 1 kg / m2 and therefore acceptable for commercial use. Nevertheless, significant differences are observed between the products according to the invention (LAC0.3, LAC0.6, LAS0.3 and LAS0.6) and the reference product (LRef), the latter being much more sensitive to humidity.

[0076] Example 4: Measurement of expansion

[0077] The rate of expansion of the insulating products prepared in Example 1 upon application was evaluated as follows.

[0078] These products were initially presented in bagged form and had the appearance of mattresses with a given width, length, and thickness. The width of these mattresses was measured before and immediately after the bags were opened and stored for a given time at room temperature after bagging. The expansion rate was calculated as the ratio of the width after opening to the width before opening. An expansion rate of 100% thus means that the mattress is unable to regain its pre-bagging dimensions.

[0079] The results of these tests are summarized in the Table below.

[0080] [Tables3] Time (days) Expansion Rate (%) LRef LAS0.3 LAS0.6 LAC0.3 LAC0.6 90 232 253 246 253 246 194 172 254 237 246 235

[0081] As can be seen from this table, all values ​​are greater than 150% and therefore acceptable for commercial use. Nevertheless, significant differences are observed between the products according to the invention (LAC0.3, LAC0.6, LAS0.3 and LAS0.6) and the reference product (LRef), the latter tending to compact over time.

[0082] Example 5: Measurement of the level of volatile organic compounds

[0083] The total volatile organic compound (VOC) emissions from some of the insulating products prepared in Example 1 were evaluated according to ISO 16000 (in particular ISO 16000-11:2006 with regard to sample preparation and ISO 16000-6:2021 with regard to the measurement method).

[0084] The results of these tests are summarized in the Table below.

[0085] [Tables4] Time (d) TVOC (pg / m3) Total Cyclosiloxanes (pg / m3) LRef LAC0.3 LAC0.6 LRef LAC0.3 LAC0.6 3 2800 940 750 1644 425 292 28 1200 680 310 993 599.2 231.1

[0086] As shown in this table, all 28-day TVOC values ​​are below 1500 pg / m3 and therefore fall under category A as defined by French regulations concerning VOC emissions (Decree DEVL1101903D) of March 2011 and Decree DEVL1104875A of April 2011 amended in February 2012). The insulating products according to the invention emit less VOC than the reference product, in particular less cyclosiloxanes, and are even compliant with category A+.

[0087] Example 6: Measurement of the acid content on fibers

[0088] The amount of citric acid present on the LAC0.3 glass wool obtained in Example 1 was evaluated.

[0089] Protocol:

[0090] To determine the amount of residual citric acid in blown wool, leaching with ultrapure water is performed. The leaching process involves placing 15 g of blown wool in 450 mL of ultrapure water and using a propeller mill to promote contact between the fibers and the water (for only 1 minute). The leaching time required for complete extraction of citric acid is 24 hours. Subsequently, filtration is performed to separate the fibers from the leachate, which is then analyzed by ion chromatography with conductimetric detection. The ion chromatograph is calibrated with a citric acid standard in external calibration mode.

[0091] Results:

[0092] The LAC3.0 glass wool had a residual acid content of 0.26%.

Claims

Demands

1. Mineral wool free of organic binder, comprising glass fibers coated with at least one monomeric acid having a boiling point of at least 135 °C and at least one silicone.

2. Mineral wool according to claim 1, characterized in that the boiling point of the acid is at least 140 °C, preferably at least 150 °C, more preferably at least 160 °C or even at least 170 °C; and advantageously less than 300 °C.

3. Mineral wool according to claim 1 or 2, characterized in that the acid comprises one or more acid functions and has at least a pKa at 25 °C greater than -1.74 and more preferably greater than 0.

4. Mineral wool according to any one of claims 1 to 3, characterized in that the acid is selected from organic or inorganic acids, in particular organic acids containing at least one carboxylic acid function and inorganic acids containing at least one sulfonic acid function, as well as mixtures thereof, preferably from citric acid, sulfamic acid, malic acid and mixtures thereof, more preferably the acid is selected from citric acid and sulfamic acid, better, the acid is citric acid.

5. Mineral wool according to any one of claims 1 to 4, characterized in that the amount of acid ranges from 0.1 to 0.8%, preferably from 0.2 to 0.6% and more preferably from 0.2 to 0.5% by weight, relative to the weight of the glass fibers.

6. Mineral wool according to any one of claims 1 to 5, characterized in that the glass fibers have a fineness between 4 L / min and 9 L / min.

7. Mineral wool according to any one of claims 1 to 6, characterized in that the silicone is selected from a trimethylsiloxane ending in or OH.

8. A method for manufacturing blown wool, comprising: - the transformation of molten glass into fibers, - the application to the fibers of at least one monomeric acid having a boiling point of at least 135°C and at least one silicone, contained in one or more compositions each devoid of compounds capable of polymerizing with each other and / or with acid, - collection of fibers, - grinding of fibers, - possibly, treatment of ground fibers with at least one antistatic additive and / or at least one anti-dust additive, - packaging of ground fibers possibly treated.

9. A process according to claim 8, characterized in that the fibers are dried at an ambient temperature of 135 to 220 °C, preferably 150 to 210 °C, before or after the collection step.

10. Use of mineral wool according to any one of claims 1 to 7 as thermal insulation of a structure, wherein the mineral wool is blown into a cavity or onto a surface of said structure.

11. Use of a monomeric acid having a boiling point of at least 135 °C to protect blown wool, comprising silicone-coated glass fibers, against moisture, in particular to prevent or reduce corrosion of the glass and / or compaction of the glass wool and / or emission of volatile organic compounds, in particular cyclosiloxanes.

12. A method for protecting blown wool, comprising silicone-coated glass fibers, against moisture, in particular to prevent or reduce corrosion of the glass and / or compaction of the glass wool and / or emission of volatile organic compounds, in particular cyclosiloxanes, comprising applying to the glass fibers at least one monomeric acid having a boiling point of at least 135 °C.

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