Mineral wool

Abstract

According to a first aspect, the invention relates to a mineral wool suitable for being blown, the mineral wool comprising mineral fibers and potassium acetate. The invention also relates, according to a second aspect, to a method for preparing a mineral wool according to the invention, comprising a step of spraying potassium acetate onto the mineral wool. According to a third aspect, the invention relates to a thermal and / or acoustic insulation coating obtained by blowing a mineral wool according to the invention above. The invention also relates to a method for applying an insulation coating above, comprising a step of blowing a mineral wool according to the invention. Finally, according to another aspect, the invention relates to the use of potassium acetate as an antistatic agent in a mineral wool suitable for being blown. Figure 1.

Description

Title of the invention: Mineral wool Technical field

[0001] The invention relates to the field of thermal and / or acoustic insulation using blown mineral wool, in particular for applications in construction. The present invention relates more particularly to a loose insulation product comprising a blown mineral wool, preferably a glass wool, as well as a coating obtained by blowing such a product. TECHNOLOGICAL BACKGROUND

[0002] It is known to thermally and / or acoustically insulate a wall of a building, for example a wall, a floor or a floor, by depositing blown mineral wool, for example glass wool, in contact with the wall, for example in a wall cavity or on the horizontal surface of an attic. The loose glass wool can be packaged in a bag, in particular in compressed form, and undergo a first expansion when the bag is opened. The glass wool flakes can optionally be decompacted before being placed in a mineral wool blowing device or be introduced directly into a blowing device equipped with a carding machine, allowing the mineral wool to be subjected to a second expansion. The glass wool is then transported from the blowing device to the wall to be insulated using a long pneumatic conduit.This method of insulating with loose mineral wool has the advantage of being easy and quick to apply to both new and old buildings, of being able to cover walls with irregular morphology and of being a relatively inexpensive material. This method also reduces the volume of glass wool that needs to be stored and transported between its production and use.

[0003] When blowing mineral wool, the distribution of the latter through the pneumatic conduit and the application nozzle generally creates electrostatic charges on the surface of the fibers, by triboelectric effect. These electric charges repel each other, causing the dispersion of small fiber particles in the ambient atmosphere, the formation of a cloud of "dust" and the adhesion of the particles to most surfaces, including the user. This dust poses a comfort problem for the operator during blowing and complicates the application by spreading a significant quantity of particles which stick to the walls and the user's clothing, which may also require a larger quantity of product than expected.

[0004] It is known to reduce the amount of dust emitted when blowing wool glass wool by adding antistatic agents to the glass wool. US4555447 describes, in particular, the use of quaternary ammonium salt-based antistatic agents to reduce the tendency of small fiber particles to disperse. However, these agents tend to negatively impact the thermal insulation properties and / or the blown density of mineral wools.

[0005] The amount of dust emitted during blowing can also be reduced by adding mineral oil to the glass wool. However, the addition of mineral oil to the glass wool results in an increase in the thermal conductivity X of the blown glass wool, which reduces the thermal and / or acoustic performance of the blown glass wool. For example, document US20170198472 describes the use of a reduced amount of mineral oil applied to the glass fibers (between 0.1% and 0.6% of the weight of the glass fibers) to limit the negative impact on the thermal conductivity. However, the thermal conductivity of the described glass wool remains high in relation to the average density of the bulk material and the thickness used.

[0006] Thus, there is still a need to have a loose insulation product allowing a significant reduction in the quantity of particles emitted and dust generated during installation of the product by a user, while presenting satisfactory thermal performances, in particular a low thermal conductivity for a predetermined density of mineral wool.

[0007] It is to the applicant's credit to propose a blown mineral wool which, surprisingly, makes it possible to solve all of these problems. Summary of the invention

[0008] According to a first aspect, the invention relates to a mineral wool suitable for being blown, the mineral wool comprising mineral fibers and potassium acetate.

[0009] Surprisingly, the inventors have demonstrated that the presence of potassium acetate on mineral wool, even at low content, has an effect on the average charge of the mineral fibers during blowing, and that a zero or positive average charge of the fibers makes it possible to observe an antistatic effect greatly limiting the phenomenon of dispersion of particles and the “dust” effect on the user’s clothing or on the walls adjacent to the wall to be insulated. More particularly, the inventors have demonstrated that a mineral wool comprising potassium acetate has, during blowing, a zero (or close to zero) average charge.

[0010] The invention also relates, according to a second aspect, to a process for preparing a mineral wool according to the invention, comprising a step of spraying potassium acetate onto the mineral wool.

[0011] According to a third aspect, the invention relates to a thermal and / or acoustic insulation coating obtained by blowing mineral wool according to the invention above.

[0012] The present invention also relates to a method of applying an above insulation coating, comprising a step of blowing a mineral wool according to the invention.

[0013] According to another aspect, the invention relates to the use of potassium acetate as an antistatic agent in a mineral wool suitable for being blown. DETAILED DESCRIPTION

[0014] The general terms used in this text are defined below.

[0015] The expression “comprising” encompasses the expression “consisting of”.

[0016] The expression “from ... to ...” must be understood inclusively.

[0017] The mineral wool according to the invention is suitable for being blown and comprises fibers minerals and potassium acetate.

[0018] The term "mineral wool" means a set of mineral fibers intermixed so as to form interstices capable of housing air. The interstices can house more or less air, depending on whether the mineral wool is more or less dense or compressed. The mineral fibers can be produced by melting an inorganic raw material, preferably glass, rock, and / or a slag. In particular, "glass wool" means a set of intermixed glass fibers and interstices containing air.

[0019] More particularly, the invention relates to mineral wool suitable for being blown, i.e. loose mineral wool or mineral wool in flake form. Loose mineral wool, which may or may not be in compacted form, consists of a multiplicity of individual and discrete tufts or flakes, as opposed to insulations with a unitary or monolithic overall structure which require the presence of binders. “Flakes” means pieces formed from agglomerates (or clusters) of entangled fibers having a certain size or dimension (e.g. 0.5 to 10 cm). Thus, loose glass wool according to the present invention is not comparable, for example, to fiberglass veils, glass wool panels or glass fiber reinforced materials (such as, for example, resins, plasterboards or wood panels, reinforced with glass fibers).

[0020] Advantageously, the mineral wool according to the invention is free of binders.

[0021] The term "binder" means a compound added to mineral fibers in an amount and sufficient distribution to allow mineral fibers to be bound (or combined) together, so as to form a cohesive whole. Examples of binders include cements, thermosetting resins, thermoplastic polymers, etc. Additives such as fire resistance enhancers, anti-corrosion agents, etc. dust(s), hydrophobic agents, antistatic agents, or colorants are not considered binders.

[0022] Unless explicitly stated, the term "free of binders" within the meaning of the present invention means a binder mass content of less than or equal to 1% relative to the total mass of the mineral wool, preferably less than or equal to 0.5% and more preferably less than or equal to 0.1%. More particularly, no binder is added during the preparation of the mineral wool according to the invention and the binder content corresponds to any residual binders provided by the raw materials used to manufacture the mineral wool (for example cullet or other recycled raw materials).

[0023] Advantageously, the mass content of potassium acetate in the mineral wool according to the invention is at least 0.02%, preferably at least 0.05%, more preferably at least 0.1%, better still at least 0.2%, relative to the total mass of the mineral wool.

[0024] Preferably, the mass content of potassium acetate in the mineral wool according to the invention is at most 1%, preferably at most 0.6%, more preferably at most 0.4%, relative to the total mass of the mineral wool.

[0025] Preferably, the mass content of potassium acetate in the mineral wool according to the invention is from 0.02% to 1%, preferably from 0.05% to 0.6%, more preferably from 0.1% to 0.4%, relative to the total mass of the mineral wool. This makes it possible to combine better efficiency, both in terms of antistatic effect and thermal properties.

[0026] Potassium acetate can, for example, be deposited on mineral fibers by spraying an aqueous solution of potassium acetate.

[0027] Advantageously, the mass content of mineral fibers in the mineral wool according to the invention is at least 92%, preferably at least 95%, preferably at least 97%, more preferably at least 98.8%, relative to the total mass of the mineral wool.

[0028] The mineral wool according to the invention may further comprise at least one additive, notably chosen from anti-dust agents, hydrophobic agents, antistatic agents, and colorants.

[0029] The term “anti-dust agent(s)” means a compound which makes it possible to reduce the quantity of dust released when blowing the mineral wool, and thus to prevent the penetration of fine particles of mineral fibers into the respiratory tract of the user. As non-limiting examples of anti-dust agent(s) which can be used, mention may be made of oils, for example an oil of vegetable origin and / or an oil of mineral origin. The mass content of anti-dust agent(s) may for example be from 0.3% to 1.2%, preferably from 0.5% to 1%, relative to the total mass of the wool mineral.

[0030] The term "hydrophobizing agent" means a compound which, when deposited on the mineral wool, makes it possible to give it hydrophobic properties. As non-limiting examples of hydrophobizing agents which can be used, mention may be made of silicone oils such as, for example, polydimethylsiloxane (PDMS). The mass content of hydrophobizing agent(s) may, for example, be from 0.05% to 0.4%, preferably from 0.1% to 0.2%, relative to the total mass of the mineral wool.

[0031] The term "antistatic agent" means a compound which, when deposited on the mineral wool, makes it possible to reduce the phenomenon of electrostatic adhesion during the blowing of the mineral wool, for example by increasing the average electrostatic charge of the blown mineral wool. As non-limiting examples of antistatic agents which can be used, mention may be made of a tertiary ammonium, a quaternary ammonium, a polyethylene glycol or a mixture of these compounds. The mass content of antistatic agent(s), other than potassium acetate, may for example be from 0.01% to 0.30%, preferably from 0.02% to 0.2%, relative to the total mass of the mineral wool.

[0032] Advantageously, the total content of additives, including potassium acetate, is at most 3% by mass, preferably at most 2% by mass, more preferably at most 1.2% by mass, relative to the total mass of the mineral wool. This makes it possible to optimize the thermal properties of the mineral wool since the additives tend to promote heat transfer through the mineral wool and therefore to degrade its insulating properties. Preferably, the total content of additives in the mineral wool according to the invention is from 0.4% to 1.2% by mass, preferably from 0.6% to 1% by mass, relative to the total mass of the mineral wool. This makes it possible to optimize the thermal properties of the mineral wool while allowing good ease and comfort of installation when blowing the mineral wool. The additive(s) may be added to the mineral fibers by spraying, for example in liquid form.

[0033] Advantageously, the mineral fibers of the mineral wool according to the invention are glass fibers. In other words, the mineral wool is a glass wool.

[0034] Preferably, the composition of the glass fibers comprises the following constituents, their sum representing at least 80% by mass of the glass composition: - SiO2, preferably at a mass content of 50% to 80%, - Na2O, preferably at a mass content of 5% to 25%, and - CaO, preferably at a mass content of 5% to 20%, the percentages being expressed relative to the total mass of the composition of the glass fibers.

[0035] The composition of the glass fibers may further comprise the following constituents: - MgO, preferably at a mass content of 0% to 10%, - A12O3, preferably at a mass content of 0% to 10%, - K2O, preferably at a mass content of 0% to 10%, - B2O3, preferably at a mass content of 0% to 10%, and / or - Fe2O3, preferably at a mass content of 0% to 15%, the percentages being expressed relative to the total mass of the composition of the glass fibers.

[0036] It is understood that this is the composition expressed, by convention, in oxides of the constituent elements (SiO2, Na2O, CaO, K2O, PbO, etc.). Indeed, glass is a substance of variable composition, resulting from complex reactions forming a random network. Although conventionally the compositions of glass are expressed in oxides of different elements, glass is not a mixture of these different oxides and does not contain these oxides as such.

[0037] Advantageously, the mineral wool according to the invention is packaged, for example packaged in a container or a bag, preferably in compressed form. More preferably, the mineral wool according to the invention, packaged and compressed, has a density of 100 kg / m3 to 200 kg / m3, preferably of 120 kg / m3 to 180 kg / m3. Here, the density of the mineral wool corresponds to the ratio of the mass of the mineral wool compressed in a container filled with the mineral wool, to the volume of the container. Mineral wool manufacturing

[0038] The mineral wool according to the invention can be produced according to a conventional method for manufacturing mineral wool, in which a step of adding potassium acetate is implemented. A method for manufacturing mineral wool is for example described in document WO2023 / 002138, incorporated by reference. In particular, a glass wool production facility generally comprises a fiberizing unit, in which the mineral fibers are produced. The glass composition, previously melted in a furnace, flows into a centrifugation device provided with a peripheral strip pierced with a multitude of orifices through which the molten material can flow, forming filaments. Hot air can also be blown in order to orient the fibers, lengthen them by making them finer and / or direct them to collect them on a conveyor (for example a belt).The entire fiber assembly can then undergo a grinding step and the resulting mineral wool particles or flakes can be collected and conveyed using a pneumatic conduit.

[0039] Additives may further be sprayed, for example in liquid form, onto the formed mineral fibers. A spraying step may for example be carried out using spray rings after the step of stretching the fibers under hot air. (in particular under the fiberizing plate for hydrophobic agents) and / or using spray nozzles placed in the pneumatic conduit which transports the mineral wool flakes (in particular for the addition of potassium acetate). The additive(s) may be mixed, and / or optionally diluted in a solvent, before being sprayed or nebulized onto the fibers. The sprayed or nebulized liquid comprising the additive(s) may be distributed homogeneously over the surface of the fibers, in part or entirely, so as to form a coating of additives after the solvent has evaporated from the liquid. The liquid may also form droplets on the surface of the fibers, so that, after the solvent has evaporated, the additive(s) form discrete deposits on the fibers. The spraying step may optionally be followed by a drying step to evaporate the solvent.

[0040] The present invention also relates, according to a second aspect, to a process for preparing a mineral wool according to the invention, comprising a step of spraying potassium acetate onto the mineral wool.

[0041] Advantageously, the potassium acetate is sprayed in liquid form, preferably in solution in a solvent, preferably water. For example, the potassium acetate may be present at a content of 40% to 70% by mass in water, for example at 50% by mass in water.

[0042] Advantageously, the potassium acetate is sprayed onto the mineral wool using at least one spray nozzle, and more particularly, a nebulizing nozzle. This allows for better distribution of the potassium acetate on the surface of the mineral fibers in the form of fine droplets.

[0043] Advantageously, the spraying step is carried out in a pneumatic conduit intended to transport the mineral wool. This allows a better distribution of the potassium acetate on the surface of all the mineral fibers since, in pneumatic transport, the mineral wool flakes are relatively separated and "open". In addition, the air flow of the pneumatic transport allows the mineral wool to dry by facilitating the evaporation of the solvent used (for example water).

[0044] Preferably, the spraying step is carried out after a step of grinding the mineral wool.

[0045] According to a third aspect, the invention relates to a thermal and / or acoustic insulation coating obtained by blowing mineral wool according to the invention.

[0046] “Blowing” of mineral wool means blowing defined by standard EN 14064-1:2007, and preferably defined by the document “Cahier Technique 8, Confection des exemples d’essais pour les produits en vrac, Index de révision C, date de mise en application : 01 / 07 / 2019, ACERMI”, referring to annex C.2.1 of standard EN 14064-1:2007.

[0047] Blown mineral wool forms a coating by accumulating in layers the Blown mineral wool flakes. The resulting coating is used to insulate a building wall, such as a wall, floor, or slab. The effectiveness of the insulation depends on various parameters, such as the thickness of the coating, but also the density of the blown mineral wool coating and its thermal conductivity coefficient.

[0048] Preferably, the coating according to the invention has a blown density of 5 kg / m3 to 18 kg / m3, preferably of 7 kg / m3 to 12 kg / m3.

[0049] The "density" of a blown mineral wool covering can be obtained by calculating, using a container filled with blown mineral wool, the ratio of the mass of blown mineral wool to the volume of the container. More precisely, the measurement of the density of blown mineral wool is defined in the document "Cahier Technique 8, Confection des exemples d'essais pour les produits en vrac, Index de révision C, date of application: 01 / 07 / 2019, ACERMI", referring to Annex C.2.1 of standard EN 14064-1: 2007.

[0050] Preferably, the coating according to the invention has a thermal conductivity coefficient X of at most 55 mW.m *.K '. In particular, the coating according to the invention may have a thermal conductivity coefficient X of 35 mW.m '.K 1 to 55 mW.m *.K ', preferably of 40 mW.m '.K 1 to 52 mW.m *.K '.

[0051] The "thermal conductivity coefficient" (or "lambda coefficient (X)") represents the capacity of a material to facilitate or not thermal exchanges. The lower this coefficient, the more insulating the material. The principle consists of quantifying the thermal exchanges between two surfaces of a material (on the basis of a material having a surface area of ​​1 m2 and a thickness of 1 m), with a temperature difference of one kelvin between these two surfaces. In particular, the measurement of thermal conductivity X (expressed in Watt per meter Kelvin) is defined in the document "Cahier Technique 8, Confection des exemples d'essais pour les produits en vrac, Index de révision C, date of application: 01 / 07 / 2019, ACERMI", referring to standard EN 14064-1:2007.The thermal conductivity coefficient (X) is used to determine the thermal resistance (R) of a material (which reflects the insulating power of the material and depends both on its thickness (e) and the thermal conductivity coefficient (X): (R) = (e) / (X), expressed in m2.K / W).

[0052] The present invention also relates to a method of applying an insulation coating according to the invention, comprising a step of blowing a mineral wool according to the invention.

[0053] According to another aspect, the invention relates to the use of potassium acetate as an antistatic agent in a mineral wool suitable for being blown.

[0054] Surprisingly, the inventors have demonstrated that a mineral wool comprising potassium acetate has, after blowing, an average charge zero (or close to zero), and that potassium acetate has an antistatic effect which significantly limits the phenomenon of mineral fibers sticking to the user's clothing and / or to the surrounding walls.

[0055] The term “average charge” means the average of the charges of the mineral fibers measured during the blowing of the product. It can, for example, be measured by arranging, at the outlet of the pneumatic conduit allowing the blown mineral wool to be deposited on the wall to be insulated, a portable electrostatic sensor (for example a sensor of the Keyence SK-050 model). Examples

[0056] The example below was carried out in order to evaluate the impact of potassium acetate on the properties of blown mineral wool.

[0057] In a first step, a glass wool is manufactured in a standard fiberizing unit and taken from a conveyor after a grinding step. The taken glass wool also comprises a standard hydrophobic agent (silicone), added at the time of fiberizing, in a content of less than 0.6% by mass. In this example, the mineral wool samples also contain an anti-dust agent(s) (mineral oil), added after the possible antistatic agent, the total of the sum of the contents of hydrophobic agent and anti-dust agent(s) being 0.6% by mass.

[0058] In a second step, several samples are prepared to evaluate the impact of antistatic agents impregnated on mineral wool: - “A” glass wool without antistatic agent (containing only the anti-dust and hydrophobic agents mentioned above in a total content of 0.6% by mass); - a glass wool “B” comprising (in addition to the two additives above) 0.2% of an antistatic agent known and used in commercial glass wool, this antistatic agent comprising a mixture (57 / 43) of polyethylene glycol (PEG) and quaternary ammoniums (Momar 3006) respectively; - a “C” glass wool comprising (in addition to the anti-dust and hydrophobic agents mentioned above) 0.2% potassium acetate. The antistatic agent "PEG / Momar 3006" and potassium acetate are sprayed in a diluted form in water using spray nozzles into a pneumatic duct. For the three types of glass wool "A", "B" and "C", the previously mentioned anti-dust agent(s) is added in pure form using spray nozzles into the pneumatic duct, if necessary after the antistatic agent spraying step. Then the mineral wool samples are packed in bags in compressed form (density of approximately 150 kg / m3) and stored at room temperature for an aging period of 45 days.

[0059] The properties of three types of blown mineral wool samples ("A", "B" and "C") are then evaluated. For each of these three types of samples, four batches are tested, the average of the four batches being retained.

[0060] The average charge of the mineral wool samples is measured using a portable electrostatic sensor (Keyence model SK-050) arranged at the outlet of a pneumatic conduit of a mineral wool blowing apparatus. The sensor measures an electrical potential difference AV (in kV) near a path along which the blown product is transported, between an electrical potential measured during the passage of the blown product along the path and an electrical potential measured at the same location, in the absence of passage of the blown product along the path. The measured potential difference is proportional to the average charge of the fibers passing through the path, and evolves in the same direction.

[0061] The average charge values ​​of the blown mineral wool flakes are illustrated in [Fig.l]. The mineral fibers not treated with an antistatic agent (samples "A") have a significant negative average charge, but such negative charges tend to exhibit poor electrostatic properties (in particular adhesion of particles to the surface of clothing). In contrast, the mineral fibers treated with potassium acetate (samples "C") exhibit, after blowing, a zero average charge (close to zero, or even very slightly positive), which demonstrates the effect of potassium acetate on the triboelectric charge. A zero or positive charge of the blown fibers (as is the case for samples "C" and "B" respectively) makes it possible to observe an antistatic effect of the mineral wools on the user's clothing.This was also confirmed during blowing tests of “C” samples where good blowing comfort could be observed.

[0062] The thermal properties of the insulation coating, obtained by blowing the above samples, were also evaluated. The results are listed in Table 1 below. [Tables 1] Sample reference Density in kg / m3 (according to ACERMI 590x590) Thermal conductivity coefficient “lambda” in mW / (mK) A 8.2 48.6 B 7.4 55.8 C 7.6 51.8

[0063] In conclusion, the mineral wool according to the invention comprising acetate of potassium exhibits good behavior during blowing while allowing the achievement of thermal insulation properties comparable to, or even better than, known mineral wools treated with an antistatic agent “PEG / Momar 3006”.

Claims

Claims

1. Mineral wool suitable for being blown, the mineral wool comprising mineral fibers and potassium acetate.

2. Mineral wool according to claim 1, the mineral wool comprising a mass content of potassium acetate of at least 0.02%, preferably at least 0.05%, more preferably at least 0.1%, even more preferably at least 0.2%, relative to the total mass of mineral wool.

3. Mineral wool according to any one of the preceding claims, the mineral wool comprising a mass content of mineral fibers of at least 92%, preferably at least 95%, preferably at least 97%, more preferably at least 98.8%, relative to the total mass of the mineral wool.

4. Mineral wool according to any one of the preceding claims, the mineral wool comprising at least one additive chosen from anti-dust agents, hydrophobic agents, antistatic agents, and dyes.

5. Mineral wool according to any one of the preceding claims, wherein the mineral fibers are glass fibers.

6. Mineral wool according to claim 5, wherein the composition of the glass fibers comprises the following constituents, their sum representing at least 80% of the glass composition: - SiO2, preferably at a mass content of 50% to 80%, - Na2O, preferably at a mass content of 5% to 25%, and - CaO, preferably at a mass content of 5% to 20%, the percentages being expressed relative to the total mass of the composition of the glass fibers.

7. Mineral wool according to any one of the preceding claims, the mineral wool being packaged, preferably in compressed form.

8. Mineral wool according to claim 7, preferably having a density of 100 kg / m3 to 200 kg / m3, preferably of 120 kg / m3 to 180 kg / m3.

9. A method of preparing a mineral wool according to any one of claims 1 to 8, comprising a step of spraying potassium acetate onto the mineral wool.

10. A method according to claim 9, wherein the spraying step is carried out in a pneumatic conduit intended to transport the wool mineral.

11. Thermal and / or acoustic insulation coating obtained by blowing mineral wool according to any one of claims 1 to 8.

12. A coating according to claim 11, the coating having a blown density of 5 kg / m3 to 18 kg / m3, preferably 7 kg / m3 to 12 kg / m3.

13. Coating according to claims 11 or 12, the coating having a thermal conductivity coefficient X of at most 55 mW.m *.K, preferably from 35 mW.m '.K 1 to 55 mW.m *.K, more preferably from 40 mW.m '.K 1 to 52 mW.m *.K '.

14. A method of applying an insulation coating according to any one of claims 11 to 13 comprising a step of blowing a mineral wool according to any one of claims 1 to 8.

15. Use of potassium acetate as an antistatic agent in a mineral wool suitable for being blown.

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