Composite Article Comprising Aerogel Particles and Foam

Abstract

The present invention relates to a method for preparing a composite article comprising aerogel particles and a foam, and to the composite article obtained thereby.

Description

[Technical Field]

[0001] The present invention relates to a method for preparing a composite article comprising aerogel particles and a foam, and to the composite article obtained thereby. [Background technology]

[0002] Many industrial and construction applications require thermal insulation and heat resistance at high temperatures. In view of the prior art, the present invention aims to provide foams with improved thermal insulation and heat resistance at low cost.

[0003] The inventors have surprisingly discovered that this problem can be solved by incorporating the aerogel into the foam after it has been formed. This can be accomplished by preparing an aerogel composition comprising aerogel powder and an organic solvent, and then impregnating, dipping, or pouring the aerogel composition into the foam. Summary of the Invention [Problem to be solved by the invention]

[0004] Incorporating aerogel into a foam substrate is extremely challenging due to several issues. First, in reactive foaming (e.g., PUR foaming, melamine foaming, phenolic foaming, etc.), the extremely high surface area of ​​aerogel particles dramatically increases the viscosity of the reaction system. Therefore, aerogel loading levels above 10 wt.% do not result in a reliable foaming process. Furthermore, in the foaming of thermoplastics, aerogel particles cause significant nucleation during the foaming process. Therefore, prior art techniques have not been able to achieve aerogel loading levels comparable to those achieved in the present invention when incorporating aerogel particles into a foam substrate prior to foaming. [Means for solving the problem]

[0005] Accordingly, in a first aspect, the present invention relates to a method for preparing a composite article comprising aerogel particles and a foam, the method comprising: - providing a foam-containing article comprising a foam; - providing an aerogel composition comprising an aerogel powder and an organic solvent (A); - combining a foam-containing article with an aerogel composition; and - Partial or complete removal of the organic solvent (A) to obtain a composite article.

[0006] The invention further relates to a composite article obtainable by this method.

[0007] Furthermore, the present invention relates to a composite article comprising aerogel particles and a foam, which can be obtained by impregnating, immersing or injecting an aerogel composition comprising aerogel powder, an organic solvent (A), and optionally an inorganic opacifying agent and / or a mineral filler into a foam-containing article consisting of a foam, and then partially or completely removing the organic solvent (A) to obtain the composite article.

[0008] In a further aspect, the present invention relates to a composite article comprising aerogel particles and a foam, wherein one or more of the following requirements (i) to (v) are met: (i) The weight ratio of the one or more aerogels to the one or more foams (aerogel / foam) in the composite article is 1:8 or greater; (ii) the composite article has a thermal conductivity at 0°C that is 0.030 W / m·K or less. Preferably, the thermal conductivity at 0°C is 0.028 W / m·K or less, more preferably 0.026 W / m·K or less, even more preferably 0.024 W / m·K or less, and even more preferably 0.022 W / m·K or less; (iii) the composite article has a thermal conductivity at 20°C that is 0.032 W / m·K or less. Preferably, the thermal conductivity at 20°C is 0.030 W / m·K or less, more preferably 0.028 W / m·K or less, even more preferably 0.026 W / m·K or less, and even more preferably 0.024 W / m·K or less; (iv) The composite molded article has a thermal conductivity at 40°C of 0.034 W / m K or less. Preferably, the thermal conductivity at 40°C is 0.032 W / m K or less, more preferably 0.030 W / m K or less, even more preferably 0.028 W / m K or less, and even more preferably 0.026 W / m K or less. (v) The composite article has a burn-through time (or burn-through time or burn-through time) of at least 10 minutes, and the burn-through resistance (or burn-through resistance or burn-through resistance) is determined by treating the composite article in the form of a 16 cm x 16 cm sheet of 8 mm thickness with a propane gas burner (flame source as defined in DIN EN ISO 11925-2 "Ignition properties of products subjected to direct impingement of flame - Part 2: Single flame source test") at the centre of its first major surface, the burn-through time being the time from the start of the flame treatment until the flame reaches the centre of the second major surface.

[0009] The thermal conductivities referred to herein are measured in accordance with standard DIN EN 12667, preferably using a LaserComp Fox 200 apparatus and the heat flow meter method using test specimens measuring 20x20 cm. [Brief explanation of the drawings]

[0010] BRIEF DESCRIPTION OF THE DRAWINGS [Figure 1] Thermal conductivity values ​​of Comparative Example 1 and Examples 1 to 3 [Figure 2] Photographs of Examples 2, 4 and 5 [Figure 3] The filled foam exhibits surprisingly high flexibility (Figure 3b), which is almost indistinguishable from the unfilled reference foam (Figure 3a) (Example 4). [Figure 4] No significant dusting is observed when the filled foam samples are bent: Micrographs of Example 2 show the high degree of filling and aerogel aggregation behavior (Figure 4b) versus the unfilled reference (Figure 4a): [Figure 5]Photographs of Example 2 after direct flame exposure. Flame penetration is significantly inhibited in the filled foam, with no combustion occurring even after 10 minutes of direct flame exposure: Figures 5a and 5c: Unfilled foam (Comparative Example 1): Burn-through after direct flame exposure (5a: flame-impacted side, 5c: unexposed side). Figures 5b and 5d: Filled foam (Example 2): No burn-through even after 10 minutes (5b: flame-impacted side, 5d: unexposed side). DETAILED DESCRIPTION OF THE INVENTION

[0011] Definitions used herein In the context of the present invention, the term "composite article" is understood to refer to any article containing one or more aerogel particles and one or more foams. Thus, the term "composite" does not imply any limitation other than the presence of aerogel particles and foam, which together form a foam-containing article. It should be understood that the aerogel particles and foam are not spatially separated. Rather, the aerogel particles are typically located within the foam.

[0012] The composite article is typically in the form of a foam sheet, tube, or other molded shape. The composite molded article preferably has a thickness in the range of 3 mm to 500 mm, preferably in the range of 3 mm to 100 mm, more preferably in the range of 3 mm to 50 mm, and even more preferably in the range of 5 mm to 30 mm. The extension in the other two dimensions is preferably at least five times the thickness in each case. The term "dimension" as used herein should be understood to refer to the three known spatial dimensions (as understood by "three dimensions") that are mutually orthogonal.

[0013] As used herein, the term "sheet" typically refers to a foam-containing article that extends less in one dimension than in the other two. Preferably, it refers to a foam-containing article that extends up to 1000 mm, preferably up to 500 mm, more preferably up to 100 mm in only one dimension, while extending at least 5 times in each of the other two dimensions. In other words, the term "sheet" typically refers to a flat or rectangular article.

[0014] Unless otherwise specified, the use of the singular or plural should be understood to allow for the presence of "one or more" of the singular or plural noun. In particular, the term "an article comprising a foam" refers to "an article comprising one or more foams." Similarly, the term "an aerogel composition comprising an aerogel powder and an organic solvent" should be understood to include the case where the aerogel composition contains more than one type of aerogel powder and / or more than one type of organic solvent. Mixtures of different types of aerogel powders and / or mixtures of different types of organic solvents may be used.

[0015] As used herein, the term "melamine-formaldehyde resin" or "melamine-formaldehyde binder" refers to an oligomer (or mixture of oligomers) derived primarily (typically at least 50% by weight) from melamine and formaldehyde, with formaldehyde acting as a crosslinker. Melamine typically reacts with formaldehyde under alkaline conditions to form a mixture of various oligomers, also known as methylol melamine. Thus, "melamine-formaldehyde resin" or "melamine-formaldehyde binder" preferably refers to an oligomer obtained from the reaction of melamine and formaldehyde, containing at least 50% by weight, preferably 60% by weight, more preferably 70% by weight, even more preferably 80% by weight, even more preferably 90% by weight, or even more preferably 95% by weight or 98% by weight of the atoms. Upon further heating, such oligomers undergo condensation or readily react with thiol, hydroxyl, carboxyl, and amide groups to form a three-dimensional thermosetting polymer network. Due to its oligomeric nature, it is soluble in water or mixtures of water and organic solvents (i.e., the solubility is preferably greater than 5 g / l in a 1:1 weight ratio mixture of water and 2-propanol at 20°C). In differential scanning calorimetry (DSC), the DSC thermogram of a "melamine-formaldehyde resin" or "melamine-formaldehyde binder" typically exhibits an exothermic enthalpy in the temperature range of 100-200°C (preferably, the enthalpy integral in this range is 10 J g). -1 A "melamine-formaldehyde resin" or "melamine-formaldehyde binder" is typically used in the manufacturing method of the present invention, while the final product typically includes a crosslinked product thereof, which is referred to herein as a "melamine resin" or a "crosslinked melamine-formaldehyde resin."

[0016] As used herein, the term "melamine resin" or "crosslinked melamine-formaldehyde resin" refers to a polymer obtainable by crosslinking a "melamine-formaldehyde resin" or "melamine-formaldehyde binder." Crosslinking, also known as "curing," typically refers to heating at a temperature of at least 100°C, typically 120-180°C, for 1-8 hours. Thus, "melamine resin" or "crosslinked melamine-formaldehyde resin" preferably relates to a polymer containing at least 50% by weight, preferably 60% by weight, more preferably 70% by weight, even more preferably 80% by weight, even more preferably 90% by weight, or even 95 or 98% by weight, of atoms derived from the reaction of melamine and formaldehyde. "Melamine resins" or "crosslinked melamine-formaldehyde resins" are typically crosslinked materials and are insoluble in neither water nor in mixtures of water and organic solvents (i.e., the solubility is preferably less than 5 g / L in a 1:1 weight ratio mixture of water and 2-propanol at 20°C). Due to their crosslinking nature, DSC thermograms of "melamine resins" or "crosslinked melamine-formaldehyde resins" typically do not exhibit an exothermic enthalpy in the temperature range of 100-200°C (preferably, the enthalpy integral in this range is less than 10 J g -1 (See below.) The definition of "melamine resin" also applies to melamine in melamine foam.

[0017] As used herein, the term "aerogel" refers to a porous material derived from a gel in which the liquid component of the gel has been essentially replaced by a gas without disrupting the gel structure. Preferably, the "aerogel" is a silica aerogel. Such silica aerogels typically have a density of 0.1 g / cm. 3 or less, preferably 0.05 g / cm 3 It has the following density and can be prepared by the well-known Stoeber process: In the present invention, "aerogel" is preferably a silica aerogel obtained according to the process described in EP 2 722 311 A2, preferably as defined in claim 22 thereof.

[0018] In the present invention, the term "aerogel particles" refers to silica aerogel particles, preferably obtainable according to the process described in EP 2 722 311 A2, preferably as defined in claim 22 thereof. Aerogel particles suitable for use in the present invention are commercially available, for example, as "Jios AeroVa", with "D20 grade" being preferred. "Jios AeroVa D20 grade" has a D95 particle size range of less than 20 μm, a density of 0.03-0.1 g / cm. 3 Bulk density of 0.017~0.022W / m·k, thermal conductivity of 600~800m 2 / g and a porosity of over 90%.

[0019] The term "heterophase reaction" preferably refers to a reaction carried out in a system containing two or more phases, for example a system consisting of two immiscible phases, namely an aqueous phase and a phase that is preferably a non-polar solvent phase and is not miscible with the aqueous phase. The reaction, i.e., the formation of the initial structure, begins at the interface of the different phases. It is therefore not relevant to reactions in which all reactants are dissolved in the same solvent. Examples of "heterophase reactions" are emulsion reactions, suspension reactions, or dispersion reactions.

[0020] The term "foam-containing article" refers to an article that contains one or more foams. Examples therefore include foam sheets, tubes, or other molded articles. The foam-containing article preferably has a thickness in the range of 3 mm to 500 mm, preferably in the range of 3 mm to 100 mm, more preferably in the range of 3 mm to 50 mm, and even more preferably in the range of 5 mm to 30 mm, while extending at least 5 times in each of the other two dimensions. Preferably, the "foam-containing article" is a foam.

[0021] As used herein, the term "aerogel composition" relates to any mixture comprising an aerogel powder and an organic solvent. Preferably, the "aerogel composition" is a mixture comprising an aerogel powder dispersed in an organic solvent. In other words, the "aerogel composition" is preferably an "aerogel dispersion (or aerogel dispersion)."

[0022] The term "dispersion" as used herein preferably relates to a mixture in which solid particles of one material are dispersed in a continuous phase of another material, which is a liquid. The terms solid and liquid as used herein refer to the state of the materials at a temperature of 25° C. and a pressure of 1 atmosphere. "Dispersed" preferably refers to a state in which the particles do not readily settle in the liquid continuous phase.

[0023] As used herein, the term "organic solvent" refers to any organic compound that is liquid at a temperature of 20°C and a pressure of 1 atmosphere. Preferred examples of organic solvents include hydrocarbon solvents and alcohols (including mixtures thereof). Hydrocarbons are understood to be organic compounds consisting of carbon and hydrogen atoms.

[0024] It should be understood that the term "removing the organic solvent" preferably also includes removing the water, and may also include curing (typically cross-linking) the melamine-formaldehyde resin.

[0025] The term "organic compound" as used herein refers to any compound containing at least one carbon-hydrogen bond. When calculating the content of organic compounds in the product of the present invention, foam materials and melamine-formaldehyde resins are preferably not considered as organic compounds.

[0026] In this specification, terms such as "comprise" or "contain" are used to openly express definitions of compositions, etc., such as "A comprises B." Thus, "A comprises B" is understood to indicate that A comprises at least B, but may further include any number and amounts of other components. In contrast, the term "consists of," such as "A consists of B," generally indicates that A does not contain any components other than B.

[0027] For example, a term such as "preferably" indicates that a certain characteristic may or may not be met. Thus, such a term precedes any characteristic. Generally, if the characteristic is met, an additional beneficial effect is expected.

[0028] As used herein, the term "injecting" refers to the act (or practice) of introducing (typically by application of force) a fluid (such as, for example, an aerogel composition) into a solid material (such as, for example, a foam-containing article). Suitable approaches for "injecting" are described, for example, in EP 3 023 528 A1.

[0029] As used herein, the terms "impregnating" or "soaking" refer to the act of introducing (typically without the application of force) a fluid (such as, for example, an aerogel composition) into a solid, porous material (such as, for example, a foam). "Impregnating" or "soaking" can be accomplished, for example, by either placing the foam-containing article to be impregnated or immersed in a container containing a typical liquid material with which the article is to be impregnated, or by pouring a liquid onto the article to be impregnated or immersed.

[0030] As used herein, the term "binder" refers to any material intended to provide adhesion between two solid materials. Preferably, the term "binder" refers to any material that serves to bind aerogel particles to each other and / or to the foam. Binders may be organic or inorganic in nature. Specific examples of binders include, but are not limited to, water glass, silicone-based binders, and phenolic resin-based binders.

[0031] Detailed Description of the Invention The present invention relates to a method for preparing a composite article comprising aerogel particles and a foam, and to the composite article obtained thereby.

[0032] method The present invention relates to a method for preparing a composite article comprising aerogel particles and a foam, the method comprising: - providing a foam-containing article comprising a foam; - providing an aerogel composition comprising an aerogel powder and an organic solvent (A); combining a foam-containing article with an aerogel composition; - Partial or complete removal of the organic solvent (A) to obtain a composite molding.

[0033] The method is not limited to these steps, and may include any number of additional steps before, between, or after each of these steps. Thus, the steps above are not necessarily sequential. However, it is preferred to perform them in the order specified. Furthermore, it is preferred that the steps be sequential.

[0034] Each step of the methods described herein can include additional activities. For example, the step of providing an aerogel composition comprising an aerogel powder and an organic solvent (A) can include providing an aerogel composition comprising additional components other than the aerogel powder and the organic solvent (A). Furthermore, the step of combining a foam-containing article with the aerogel composition can include combining not only the foam-containing article and the aerogel composition, but also additional articles, compositions, etc.

[0035] The foam-containing article and the aerogel composition are preferably combined by injecting, dipping, or impregnating the foam-containing article with the aerogel composition, more preferably by impregnating or dipping the foam-containing article with the aerogel composition. Suitable methods for injecting such compositions are known to those skilled in the art and are described, for example, in EP 3 023 528 A1.

[0036] Preferably, partially or completely removing the organic solvent (A) and obtaining the composite article by drying comprises drying at a temperature of 50 to 150°C for 1 to 8 hours, preferably at 100 to 120°C for 1 to 48 hours.

[0037] Composite articles obtained by this method The composite article obtained by the method of the present invention preferably comprises 50-98 wt% aerogel based on the total weight of the composite article, more preferably 60-96 wt%, even more preferably 70-95 wt%, or even more preferably 75-95 wt%, 80-95 wt%, or 85-95 wt%, such as 88-92 wt%, aerogel based on the total weight of the composite article.

[0038] The thickness of the composite article is typically in the range of 3 mm to 500 mm, preferably in the range of 3 mm to 100 mm, more preferably in the range of 3 mm to 50 mm, and even more preferably in the range of 5 mm to 30 mm.

[0039] If the width of the composite article is W, the length of the composite article is L, and the thickness of the composite article is T, the composite article preferably meets the following requirements:

number

[0040] The composite article may further comprise an inorganic opacifying agent and / or a mineral filler. Therefore, it is preferred that the step of providing an aerogel composition comprising an aerogel powder and an organic solvent (A) is a step of providing an aerogel composition comprising an aerogel powder, an organic solvent (A), and an inorganic opacifying agent and / or a mineral filler.

[0041] foam The foam used in the method of the present invention is typically a foam in which at least half (i.e., 50% or more) of the cells are interconnected. This continuous, interconnected capillary network allows liquids and gases to migrate through the open-cell or porous cell structure. The open-cell content of the foam is preferably 60 to 99%, particularly 85 to 95% or 90 to 99%. The foam preferably has an open-cell content of 40 to 99% according to ASTM D2856. The foam preferably comprises one or more selected from polyurethane (PUR) foam, polyisocyanurate (PIR) foam, melamine foam, phenolic foam, chemically crosslinked polyolefin foam, polypropylene foam, and mixtures thereof. Among these, melamine foam is particularly preferred.

[0042] Polyurethane (PUR) foam Flexible polyurethane (PUR) foams are particularly disclosed in WO 1996 / 001867 A1. Such flexible open-cell polyurethane foams can be prepared as the reaction product of a mixture containing (a) an aliphatic, cycloaliphatic, araliphatic, and / or aromatic polyisocyanate and (b) a polyol component. Component (a) is typically MDI or polymeric MDI. The polyol component can be any compound having more than one, preferably more than two, hydroxyl groups. Examples include ethylene glycol, propylene glycol, 1,4-butanediol, and 1,6-hexanediol. The polyol can also be a polyether polyol, polyester polyol, and / or polyamide polyol. Polyester polyols for polyurethanes can be prepared by the condensation reaction of a glycol (such as ethylene glycol, propylene glycol, 1,4-butanediol, or 1,6-hexanediol) with a dicarboxylic acid. Polyol components having 4 to 8 hydroxyl groups include erythritol, pentaerythritol; pentites, such as arabite, adonite, or xylitol; and hexahydrates, such as sorbitol, mannitol, or dulcitol. Low-molecular-weight reaction products of such polyhydroxy compounds with ethylene oxide and / or propylene oxide are particularly suitable, as are low-molecular-weight reaction products of other compounds containing groups capable of reacting with ethylene oxide and / or propylene oxide, such as ammonia, ethylenediamine, 1,4-diaminobenzene, 2,4-diaminotoluene, 2,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 1-methyl-3,5-diethyl-2,4-diaminobenzene, and / or 1-methyl-3,5-diethyl-2,6-diaminobenzene. Other suitable polyamines are described in EP-A-0 265 781.

[0043] Suitable crosslinkers include the reaction products of triethanolamine, aldehydes, or ketones with polyamines (such as, for example, ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), hexaethyleneheptamine, propylenediamine, dipropylenetriamine, tripropylenetetramine, tetrapropylenepentamine, pentapropylenehexamine, or hexapropyleneheptamine).

[0044] Polyisocyanurate (PIR) foam Polyisocyanurate (PIR) foams are described, for example, in WO 2020 / 142887 A1. Similar to polyurethane (PUR) foams, PIRs are typically obtained by the reaction of an isocyanate (MDI) and a polyol. In the case of PUR, the components MDI and polyol are used in a molar ratio of about 1.00, whereas in the production of PIRs, MDI is used in a molar excess (e.g., 1.01:1 or greater, 1.03:1 or greater, 1.05:1 or greater, 1.10:1 or greater, or 1.2:1 or greater). The polyol and crosslinker may be as described above for polyurethane foams.

[0045] melamine foam Melamine foams are polymers obtained by reacting melamine (2,4,6-triamino-1,3,5-triazine) with one or more aldehydes. The aldehydes are typically one or more selected from formaldehyde, acetaldehyde, trimethylolacetaldehyde, acrolein, benzaldehyde, furfuralaldehyde, glyoxal, phthalaldehyde, and terephthalaldehyde. Preferably, the aldehyde is at least 50% by weight, and more preferably, the aldehyde is formaldehyde. Thus, preferred melamine foams are foams containing a polymer obtained by reacting melamine (2,4,6-triamino-1,3,5-triazine) with formaldehyde. Melamine foams such as those described in US Pat. No. 4,334,971 and DE 10 2010 009588 A1 can be used. Thus, elastic open-cell melamine-formaldehyde resin foams can be prepared, for example, as described in EP-A 071 672 or EP-A 037 470. The molar ratio of melamine to aldehyde (e.g., formaldehyde) is generally less than 1:1, preferably 1:1 to 1:5, in particular 1:1.5 to 1:3.5.

[0046] Melamine-formaldehyde condensates can be used to prepare melamine foams. In addition to melamine, these melamine-formaldehyde condensates typically contain up to 50% by weight, preferably up to 20% by weight, of other thermosetting resin precursors as co-condensed units. In addition to formaldehyde, they may also contain up to 50% by weight, preferably up to 20% by weight, of other aldehydes as co-condensed units. Unmodified melamine-formaldehyde condensates are particularly preferred. Examples of additional thermosetting resin precursors that may be present include alkyl-substituted melamines, ureas, urethanes, carboxylic acid amides, dicyandiamide, guanidine, sulfuryl amides, sulfonic acid amides, aliphatic amines, phenols, and their derivatives. Examples of other aldehydes that can be used include acetaldehyde, trimethylolacetaldehyde, acrolein, benzaldehyde, furfuralaldehyde, glyoxal, phthalaldehyde, and terephthalaldehyde. Further details regarding melamine-formaldehyde condensates are found in Houben-Weyl, Methoden der organischen Chemie, Volume 14 / 2, 1963, pp. 319-402. The molar ratio of thermosetting resin precursor to aldehyde may vary over a wide range, i.e., from 1:1.5 to 1:5, and in the case of melamine-formaldehyde condensates, is preferably from 1:2.5 to 1:3.5. The melamine resin advantageously contains co-condensed sulfite groups; these can be introduced, for example, by adding 1 to 20% by weight of sodium bisulfite during or after the condensation of the resin. The sulfite groups make the resin more hydrophilic and increase its compatibility with water. Furthermore, higher degrees of condensation can be achieved. Such melamine-formaldehyde low-order condensates (or precondensates) can be used to prepare desired foams, for example, by foaming an aqueous or alcoholic (such as ethanolic) solution or dispersion containing the melamine-formaldehyde low-order condensate, an emulsifier, a blowing agent, a curing agent, and optional additives, and then crosslinking the low-order condensate, and the solution or dispersion is heated to affect the foaming and crosslinking.Heating can be affected by ultra-high frequency irradiation in such a way that the power uptake by the solution or dispersion is between 5 and 200 KW per kg of water or alcohol in the solution or dispersion.

[0047] Phenolic Foam Suitable phenolic foams can be found, for example, in WO 2007 / 029222 A1. Phenolic foams comprise phenolic resins. Phenolic resins contain phenol and / or phenolic compounds (preferred phenolic compounds are cresol, xylenol, para-C 1-6 The phenolic resins can be obtained by reacting a phenolic resin selected from a phenolic resin such as methyl-, ...

[0048] The production of resole resins typically uses an alkaline catalyst (e.g., sodium hydroxide, potassium hydroxide, calcium hydroxide, or an aliphatic amine such as trimethylamine or triethylamine). The molar ratio of phenolic groups (hydroxyl groups bonded to carbon atoms that are part of an aromatic group) to aldehyde groups is not particularly limited. In particular, for resole resins, the molar ratio of phenolic groups to aldehyde groups is preferably in the range of 1:1 to 1:3, more preferably 1:1.5 to 1:2.5, and particularly preferably 1:1.6 to 1:2.1.

[0049] Novolac resins are typically prepared using an acid catalyst (e.g., benzenesulfonic acid, paratoluenesulfonic acid, xylenesulfonic acid, naphthalenesulfonic acid, ethylbenzenesulfonic acid, or phenolsulfonic acid). In particular, in the case of novolac resins, the molar ratio of phenol groups to aldehyde groups is preferably in the range of 1:1 to 3:1, more preferably 1.05:1 to 2.5:1, and particularly preferably 1.2:1 to 1.5:1.

[0050] Phenolic resins can be formed either directly to produce thermosetting network polymers (typically with an excess of aldehyde groups) or by preparing prepolymers (typically with an excess of phenolic groups, e.g., as in the case of novolacs), which can then be formed and cured by adding formaldehyde and preferably by heating.

[0051] In addition to the phenolic resin, the phenolic foam preferably contains a hydrocarbon blowing agent (preferably one or more hydrocarbons having 1 to 8 carbon atoms; e.g., 1 to 20 parts by weight per 100 parts by weight of the phenolic resin), optional catalyst(s), and optionally an inorganic filler (e.g., a metal hydroxide such as aluminum hydroxide or magnesium hydroxide; or a metal carbonate such as calcium carbonate, magnesium carbonate, barium carbonate, or zinc carbonate; e.g., 0.1 to 30 parts by weight per 100 parts by weight of the phenolic resin) to adjust the pH of the foam and to prevent corrosion of metal structures in prolonged contact with the phenolic foam.

[0052] Chemically crosslinked polyolefin foam Chemically crosslinked polyolefin foams are described, for example, in WO2006 / 024658A1. Therefore, the chemically crosslinked polyolefin foam preferably contains 50 to 95% by weight of polyolefin and 5 to 50% by weight of polystyrene. A preferred example of the chemically crosslinked polyolefin foam is chemically crosslinked PE (XLPE) foam.

[0053] The proportion of polystyrene in the chemically crosslinked polyolefin foam is preferably at most 50% by weight, but can be adjusted within a wide range. Preferred ratios of polyolefin and polystyrene are 60 and 40% by weight, 70 and 30% by weight, 80 and 20% by weight, and 90 and 10% by weight, respectively.

[0054] The polyolefins used are in particular polyethylene and / or polypropylene, in each case homopolymers, copolymers or polymer blends. Mixtures of several different polystyrenes, polyethylenes and / or polypropylenes, for example with different molecular weights or melt flow indices, can also be used.

[0055] The polymeric components are used in particular without prior functionalization or compatibilization, such as grafting, etching, irradiation, flame treatment or corona treatment, for example with silanes and monomers such as styrene or methacrylate.

[0056] Preferably, the polymer foam according to the invention does not contain any other polymers in addition to the polymer components (polyolefin and polystyrene), so that the weight fraction of the aforementioned polyolefin and polystyrene represents 100% of the total polymer component of the foam. Optionally, it is possible to add small proportions of 1 to 10% by weight of further polymers, such as, for example, polyethylene vinyl acetate, polyethylene ethyl acetate, polyethylene vinyl butyral, hydrogenated polystyrene and / or polybutene.

[0057] Suitable crosslinking agents can be selected from organic peroxides and / or triallyl isocyanurate can be applied as a coagent.

[0058] Polypropylene Foam Suitable polypropylene foams are known to those skilled in the art and are disclosed in WO 1994 / 013460 A1. Suitable propylene polymers include propylene homopolymers (polypropylene) and copolymers of propylene with copolymerizable ethylenically unsaturated comonomers. The propylene polymer foam may further contain a small amount (typically 10% by weight or less, preferably 5% by weight or less) of a non-propylene-based polymer. The propylene-based polymer may be composed of one or more propylene homopolymers alone, one or more propylene copolymers, or a blend of one or more propylene homopolymers and copolymers. Regardless of composition, the propylene polymer preferably contains 50% by weight or more, more preferably at least 70% by weight, of propylene monomer units, based on the total weight of the monomer units in the propylene polymer.

[0059] Suitable monoethylenically unsaturated comonomers include olefins, vinyl acetate, methyl acrylate, ethyl acrylate, methyl methacrylate, acrylic acid, itaconic acid, maleic acid, maleic anhydride, etc. The propylene copolymer preferably contains no more than 20% by weight of the ethylenically unsaturated comonomer.

[0060] Particularly useful propylene copolymers are copolymers of propylene with one or more non-propylene olefins. Propylene copolymers include random and block copolymers of propylene with an olefin selected from the group consisting of ethylene, C4-C10 α-olefins, and C4-C10 dienes. Propylene copolymers also include random terpolymers of propylene with an α-olefin selected from the group consisting of ethylene and C4-C8 α-olefins. In terpolymers containing both ethylene and C4-C8 α-olefins, the ethylene content is preferably 20% by weight or less. Examples of C4-C10 α-olefins include linear and / or branched C4-C10 α-olefins such as 1-butene, isobutylene, 1-pentene, 3-methyl-1-butene, 1-hexene, 3,4-dimethyl-1-butene, 1-heptene, and 3-methyl-1-hexene. Examples of C4-C10 dienes include 1,3-butadiene, 1,4-pentadiene, isoprene, 1,5-hexadiene, and 2,3-dimethyl-1,3-hexadiene.

[0061] Suitable non-propylene polymers that can be incorporated into the polypropylene foam include high, medium, low and linear density polyethylene, polybutene, ethylene-acrylic acid copolymer, ethylene-vinyl acetate copolymer, ethylene-propylene rubber, styrene-butadiene rubber, ethylene-ethyl acrylate copolymer, and ionomers.

[0062] The preferred propylene copolymer resin is a branched and / or crosslinked polypropylene resin. Branching or crosslinking can be achieved by chemical or irradiation branching (see, for example, US Pat. No. 4,916,198 and US Pat. No. 4,714,716). Suitable branching / crosslinking agents include azide- and vinyl-functional silanes, organic peroxides, and polyfunctional vinyl monomers, as described in WO 1994 / 013460 A1.

[0063] The foam used in the present invention is preferably chemically and / or physically crosslinked. The degree of crosslinking according to the Flory-Stockmayer theory or gel content according to ASTM D2765 is preferably 40 to 95%. A suitable crosslinking agent can be selected by those skilled in the art based on common technical knowledge depending on the type of polymer, as described above. Additional crosslinking agents include peroxides, triallyl cyanurate, triallyl isocyanurate, phenylmaleimide, thiadiazole, fatty acid amides, hydrosilylation agents, radiation activators (for radiation or UV curing), sulfur-based agents, bisphenol-based agents, metal oxides, etc.

[0064] Preferred blowing agents for preparing the foam include aliphatic hydrocarbons having 1 to 9 carbon atoms, halogenated aliphatic hydrocarbons having 1 to 4 carbon atoms, and aliphatic alcohols having 1 to 3 carbon atoms.

[0065] Aliphatic hydrocarbons include methane, ethane, propane, n-butane, isobutane, n-pentane, isopentane, and neopentane. Among halogenated hydrocarbons, fluorinated hydrocarbons are preferred. Examples of fluorinated hydrocarbons include methyl fluoride, perfluoromethane, ethyl fluoride, 1,1-difluoroethane, 1,1,1-trifluoroethane, 1,1,1,2-tetrafluoroethane, pentafluoroethane, perfluoroethane, 2,2-difluoropropane, 1,1,1-trifluoropropane, perfluoropropane, perfluorobutane, and perfluorocyclobutane. Examples of partially halogenated chlorocarbons and chlorofluorocarbons include methyl chloride, methylene chloride, ethyl chloride, 1,1,1-trichloroethane, 1,1-dichloro-1-fluoroethane, 1-chloro-1,1-difluoroethane, 1,1-dichloro-2,2,2-trifluoroethane, and 1-chloro-1,2,2,2-tetrafluoroethane. Aliphatic alcohols include methanol, ethanol, n-propanol, and isopropanol. Mixtures of any of the above may be used as blowing agents.

[0066] Suitable inorganic blowing agents include carbon dioxide, nitrogen, argon, water, air, nitrogen, and helium. Chemical blowing agents include azodicarbonamide, azodiisobutyronitrile, benzenesulfonhydrazide, 4,4-oxybenzenesulfonylsemicarbazide, p-toluenesulfonylsemicarbazide, barium azodicarboxylate, N,N'-dimethyl-N,N'-dinitrosoterephthalamide, and trihydrazinotriazine. It should be understood that crosslinkers and blowing agents, especially chemical blowing agents, may decompose and / or evaporate from the foam during foaming.

[0067] It is understood that the foam may contain any additives commonly used in foams, such as, for example, flame retardants, inorganic fillers, plasticizers, biocides, stabilizers (heat, UV, ozone, backlash, etc.), pigments, in any type and in any proportion.

[0068] The foam (to be understood before impregnation and / or coating) preferably has a water resistance of ≦200 kg / m according to DIN EN ISO 845. 3 , more preferably ≦150 kg / m 3 In particular, for melamine foams, the density is ≦20 kg / m 3 Preferably, the density is ≦10 kg / m 3 is.

[0069] Specific examples of open-cell foams that can be used in the present invention include:

[0070] [Table 1]

[0071] Solvent (A) The organic solvent (A) used in the process of the present invention is typically a hydrocarbon solvent, preferably a C 3-16 selected from saturated, unsaturated or partially saturated hydrocarbons or mixtures thereof, more preferably C 3-10selected from saturated linear, branched or cyclic hydrocarbons or mixtures thereof, more preferably C 3-10 selected from linear or branched alkanes or mixtures thereof, and even more preferably C 5-7 It is selected from linear or branched alkanes or mixtures thereof, even more preferably from hexane or heptane or mixtures thereof, most preferably n-hexane.

[0072] Alternatively, the organic solvent (A) used in the present invention is an alcohol solvent, preferably C 2-12 is selected from saturated, unsaturated or partially saturated alcohols or mixtures thereof, more preferably C 2-12 is selected from saturated linear, branched or cyclic alcohols or mixtures thereof, more preferably C 2-12 selected from saturated linear, branched or cyclic monohydric alcohols or mixtures thereof, even more preferably C 2-6 It is selected from saturated linear, branched or cyclic monohydric alcohols (such as ethanol, 1-propanol, 2-propanol, butanol, pentanols (including cyclopentanol) or hexanols (including cyclohexanol)) or mixtures thereof or mixtures thereof, even more preferably propanol or mixtures thereof, most preferably 2-propanol.

[0073] Furthermore, the organic solvent (A) may be a mixture of one or more of the above hydrocarbon solvents and one or more of the alcohol solvents.

[0074] aerogel The aerogel may be any inorganic aerogel. Preferably, the aerogel comprises or consists of one or more selected from silicon oxide, aluminum oxide, zirconium oxide, titanium oxide, hafnium oxide, and yttrium oxide. More preferably, the aerogel comprises or consists of silicon oxide. Even more preferably, the aerogel is a silica aerogel.

[0075] Aerogels typically have a porosity of 85% or greater, more preferably 90% or greater, as determined by adsorption and desorption isotherms. More specifically, the porosity is determined by measuring the pore volume and pore size distribution of the aerogel using the Barret-Joyner-Halenda (BJH) adsorption and desorption isotherm method.

[0076] The specific surface area of ​​aerogel is typically 300m 2 / g or more. Preferably, the specific surface area of ​​solids is 400 m / g, as determined according to DIN ISO 9277 2003-05 (determination of the specific surface area of ​​solids by gas adsorption according to the BET method). 2 / g or more, preferably 500m 2 / g or more, preferably 600m 2 / g or more, and preferably 2000m 2 / g or less, more preferably 1500m 2 / g or less, more preferably 1000m 2 / g or less, and even more preferably 800m 2 / g or less.

[0077] In the present invention, the aerogel powder preferably has a median particle size (d50) measured by laser diffraction, preferably using a Malvern Mastersizer, in the range of 1 to 50 μm, preferably 5 to 40 μm, more preferably 10 to 30 μm, and even more preferably 15 to 25 μm.

[0078] Aerogel powder can be obtained, for example, by heterogeneous reaction. In this case, the aerogel powder is preferably a silica aerogel powder obtained by mixing and reacting deionized water, water glass, an organosilane compound, an inorganic acid, and an organic solvent, preferably a nonpolar organic solvent, to obtain silica hydrogel primary particles. The silica hydrogel primary particles are then subjected to solvent exchange, and the solvent-exchanged gel particles are dried under atmospheric pressure to obtain silica aerogel powder. It is preferable that further grinding and sieving processes are not performed. Such heterogeneous reaction methods are known to those skilled in the art and are described, for example, in EP 2 722 311.

[0079] The aerogel powder is preferably prepared in the form of particles instead of monoliths. Therefore, the aerogel powder used in the present invention is preferably obtained by a process that does not involve grinding of the aerogel material. More preferably, the aerogel powder is in the form of primary particles (optionally including secondary particles). Therefore, no grinding or sieving process is required to produce the aerogel powder. Furthermore, the aerogel powder is preferably dried under normal pressure, e.g., 1 atmosphere, instead of using a supercritical drying process that is sometimes employed in the production of aerogels according to the prior art.

[0080] Aerogel composition The aerogel composition comprises an aerogel powder and an organic solvent (A). It is understood that the aerogel composition may comprise additional components. To achieve efficient distribution of the aerogel powder in the foam-containing article, the aerogel composition is preferably a dispersion of the aerogel powder in the organic solvent (A).

[0081] The aerogel composition typically contains 2 to 20 wt. % aerogel, preferably 4 to 18 wt. % aerogel, more preferably 6 to 18 wt. % aerogel, even more preferably 10 to 18 wt. % aerogel, and most preferably 10 to 14 wt. % aerogel, based on the total weight of the aerogel composition, with the remainder preferably being organic solvent (A).

[0082] The total content of the aerogel powder and the organic solvent (A) in the aerogel composition is preferably 90% by weight or more, preferably 95% by weight or more, more preferably 97% by weight or more, even more preferably 98% by weight or more, still more preferably 99% by weight or more, most preferably 99.5% by weight or more, and even more preferably 99.8% by weight or more, based on the total weight of the aerogel composition.

[0083] Alternatively, when this method includes the use of an inorganic opacifying agent and / or a mineral filler, the aerogel composition is preferably a dispersion of an aerogel powder, an inorganic opacifying agent, and / or a mineral filler in an organic solvent (A). Other components may or may not be included in the aerogel composition. The inorganic opacifying agent typically comprises or consists of one or more selected from iron oxide, zirconium oxide, titanium oxide, silicon carbide, and graphite (graphite is preferably present in the composite article in an amount of less than 5 wt. %, preferably less than 2 wt. %, and more preferably less than 1 wt. %, based on the total weight of the composite article). Among these, iron oxide, zirconium oxide, titanium oxide, and / or silicon carbide are preferred. Preferably, the inorganic opacifying agent comprises or consists of one or more selected from iron oxide, zirconium oxide, and silicon carbide, and more preferably, the inorganic opacifying agent is iron oxide or silicon carbide.

[0084] The mineral filler preferably comprises or consists of one or more selected from metal hydroxides and hydrated carbonates. Preferably, the mineral filler comprises or consists of one or more selected from aluminum hydroxide, magnesium hydroxide, hydromagnesite, and hydrocalcite. More preferably, the mineral filler is one or both selected from magnesium dihydroxide and aluminum trihydroxide.

[0085] Preferably, the inorganic opacifying agent and the mineral filler are not in the form of an aerogel. Particularly preferred are inorganic opacifying agents, more preferably mineral fillers, which have a bulk density of at least 0.1 g / cm3 as tested according to DIN EN ISO 787-11. 3 and / or the inorganic opacifying agent, more preferably the mineral filler, has a specific surface area of ​​300 m, as tested according to DIN ISO 9277 2003-05 (BET method). 2 / g or less. Alternatively or additionally, it is further preferred that the inorganic opacifying agent, more preferably the mineral filler, is chemically distinct from the material used as the aerogel. It is understood that any combination of the inorganic opacifying agents and mineral fillers mentioned herein can be used.

[0086] When containing an inorganic opacifying agent and / or a mineral filler, the aerogel composition preferably contains 2 to 20 wt. % aerogel, preferably 4 to 18 wt. % aerogel, more preferably 6 to 18 wt. % aerogel, even more preferably 10 to 18 wt. % aerogel, and most preferably 10 to 14 wt. % aerogel, based on the total weight of the aerogel composition, with the remainder preferably being the organic solvent (A) and the inorganic opacifying agent and mineral filler.

[0087] When an inorganic opacifying agent and / or a mineral filler is contained, the total content of the aerogel powder and the organic solvent (A) in the aerogel composition is typically 50% by weight or more, preferably 75% by weight or more, and more preferably 85% by weight or more. Furthermore, the total content of the inorganic opacifying agent and the mineral filler in the aerogel composition is typically 50% by weight or less, preferably 25% by weight or less, and more preferably 15% by weight or less, based on the total weight of the aerogel composition.

[0088] Aerogel composition further comprising a melamine-formaldehyde oligomer resin The aerogel composition may further include a melamine-formaldehyde resin. Such aerogel compositions further containing a melamine-formaldehyde resin are typically referred to herein as "melamine-aerogel compositions." The organic solvent used in the melamine-aerogel composition is preferably an alcohol solvent.

[0089] The melamine aerogel composition comprises aerogel powder, a melamine-formaldehyde resin, and an organic solvent (A). The melamine aerogel composition preferably further comprises water. The water content in the melamine aerogel composition is preferably in the range of 1 to 30 wt %, more preferably in the range of 3 to 22 wt %, even more preferably in the range of 5 to 20 wt %, even more preferably in the range of 8 to 18 wt %, and even more preferably in the range of 11 to 17 wt %, based on the total weight of the melamine aerogel composition. It is understood that the melamine aerogel composition may comprise additional components. To achieve efficient distribution of the aerogel powder and melamine-formaldehyde resin in the fibrous article, the melamine aerogel composition is preferably a dispersion of the aerogel powder and melamine-formaldehyde resin in the organic solvent (A) (and optionally water). The organic solvent of the melamine aerogel composition is preferably an alcohol solvent as defined above.

[0090] The melamine-aerogel composition typically contains 2 to 20 wt% aerogel, preferably 4 to 15 wt% aerogel, more preferably 5 to 12 wt% aerogel, and even more preferably 6 to 10 wt% aerogel, based on the total weight of the melamine-aerogel composition. The melamine-aerogel composition further typically contains 0.1 to 20 wt% melamine-formaldehyde resin, preferably 0.1 to 10 wt% melamine-formaldehyde resin, more preferably 0.5 to 8 wt% aerogel melamine-formaldehyde resin, and even more preferably 1 to 7 wt% melamine-formaldehyde resin, based on the total weight of the melamine-aerogel composition. The remainder is preferably organic solvent (A).

[0091] The melamine-aerogel composition is preferably obtained by mixing composition A, which contains aerogel and a first solvent, with composition B, which contains a melamine-formaldehyde resin and a second solvent. The first solvent preferably contains at least 90% by weight of isopropanol. The second solvent is preferably a mixture of isopropanol and water, more preferably 40-80% by weight of isopropanol and 60-20% by weight of water, preferably 50-80% by weight of isopropanol and 50-20% by weight of water, more preferably 60-70% by weight of isopropanol and 40-30% by weight of water. The weight ratio of composition A to composition B is preferably in the range of 20:1 to 1:2, more preferably 15:1 to 1:1, even more preferably 10:1 to 1:1, and even more preferably 7:1 to 1:1. Therefore, the water content in the melamine-aerogel composition is preferably in the range of 1 to 30 wt %, more preferably in the range of 3 to 22 wt %, even more preferably in the range of 5 to 20 wt %, even more preferably in the range of 8 to 18 wt %, and even more preferably in the range of 11 to 17 wt %, based on the total weight of the melamine-aerogel composition.

[0092] The weight ratio of aerogel to melamine-formaldehyde resin in the melamine-aerogel composition is preferably in the range of 1:10 to 100:1, more preferably 1:5 to 50:1, even more preferably 1:2 to 20:1, even more preferably 1:2 to 10:1, most preferably 1:1 to 8:1, or even more preferably 1:1 to 7:1. The same ratio preferably applies to the composite article.

[0093] The total content of the aerogel powder, melamine-formaldehyde resin, and organic solvent (A), and optionally water, in the melamine-aerogel composition is preferably 90% by weight or more, preferably 95% by weight or more, more preferably 97% by weight or more, even more preferably 98% by weight or more, still more preferably 99% by weight or more, most preferably 99.5% by weight or more, and even more preferably 99.8% by weight or more, based on the total weight of the melamine-aerogel composition.

[0094] Alternatively, when this method includes the use of an inorganic opacifying agent and / or mineral filler, the melamine-aerogel composition is preferably a dispersion of aerogel powder, melamine-formaldehyde resin, inorganic opacifying agent, and / or mineral filler in an organic solvent (A). Other components may or may not be included in the melamine-aerogel composition. The inorganic opacifying agent typically comprises or consists of one or more selected from iron oxide, zirconium oxide, titanium oxide, silicon carbide, and graphite (graphite is preferably contained in the composite article in an amount of less than 5 wt. %, preferably less than 2 wt. %, and more preferably less than 1 wt. %, based on the total weight of the composite article). Among these, iron oxide, zirconium oxide, titanium oxide, and / or silicon carbide are preferred. Preferably, the inorganic opacifying agent comprises or consists of one or more selected from iron oxide, zirconium oxide, and silicon carbide, and more preferably, the inorganic opacifying agent is iron oxide or silicon carbide.

[0095] The mineral filler preferably comprises or consists of one or more selected from metal hydroxides and hydrated carbonates. Preferably, the mineral filler comprises or consists of one or more selected from aluminum hydroxide, magnesium hydroxide, hydromagnesite, and hydrocalcite. More preferably, the mineral filler is one or both selected from magnesium dihydroxide and aluminum trihydroxide.

[0096] Preferably, the inorganic opacifying agent and the mineral filler are not in the form of an aerogel. Particularly preferred is when the inorganic opacifying agent, more preferably the mineral filler, has a bulk density of at least 0.1 g / cm, as tested according to DIN EN ISO 787-11. 3 and / or the inorganic opacifying agent, more preferably the mineral filler, has a specific surface area of ​​300 m, as tested according to DIN ISO 9277 2003-05 (BET method). 2 / g or less. Alternatively or additionally, it is further preferred that the inorganic opacifying agent, more preferably the mineral filler, is chemically distinct from the material used as the aerogel. It is understood that any combination of the inorganic opacifying agents and mineral fillers mentioned herein can be used.

[0097] When containing an inorganic opacifying agent and / or mineral filler, the melamine-aerogel composition preferably contains 4 to 15 wt % aerogel, more preferably 5 to 12 wt % aerogel, and even more preferably 6 to 10 wt % aerogel, based on the total weight of the melamine-aerogel composition; preferably contains 0.1 to 10 wt % melamine-formaldehyde resin, more preferably 0.5 to 8 wt % aerogel melamine-formaldehyde resin, and even more preferably 1 to 7 wt % melamine-formaldehyde resin, based on the total weight of the melamine-aerogel composition; and the remainder is preferably the organic solvent (A) and the inorganic opacifying agent and mineral filler.

[0098] When the melamine-aerogel composition contains an inorganic opacifying agent and / or a mineral filler, the total content of the aerogel powder, the melamine-formaldehyde resin, and the organic solvent (A) in the melamine-aerogel composition is typically 50% by weight or more, preferably 75% by weight or more, and more preferably 85% by weight or more. Furthermore, the total content of the inorganic opacifying agent and the mineral filler in the melamine-aerogel composition is typically 50% by weight or less, preferably 25% by weight or less, and more preferably 15% by weight or less, based on the total weight of the melamine-aerogel composition.

[0099] Composite articles obtained using the melamine-formaldehyde resin composition preferably contain 15 to 70 wt % aerogel based on the total weight of the composite article, more preferably 20 to 60 wt % aerogel, and even more preferably 30 to 50 wt % aerogel based on the total weight of the composite article.

[0100] Composite articles obtained using the melamine-formaldehyde resin composition preferably contain 0.1 to 20 wt % of melamine resin based on the total weight of the composite article, more preferably 0.5 to 15 wt %, even more preferably 1 to 12 wt %, and even more preferably 3 to 10 wt % of melamine resin based on the total weight of the composite article.

[0101] Any coating containing crosslinked melamine-formaldehyde resin The method of the present invention may further comprise the additional step of coating the composite article with a coating composition comprising a melamine-formaldehyde resin, the composite article thus obtained may also be referred to as a coated composite article.

[0102] The step of coating the composite article with a coating composition comprising a melamine-formaldehyde resin is preferably carried out by spraying the coating composition onto the composite article to be coated.

[0103] The coating composition contains a melamine-formaldehyde resin and preferably a solvent (B). The solvent (B) includes an organic solvent and water. It is understood that the organic solvent in the solvent (B) is preferably selected so as to form a homogeneous mixture with the water in the solvent (B). More preferably, the organic solvent in the solvent (B) is an alcohol solvent, preferably C 2-12 is selected from saturated, unsaturated or partially saturated alcohols or mixtures thereof, more preferably C 2-12 is selected from saturated linear, branched or cyclic alcohols or mixtures thereof, and even more preferably C 2-12 selected from saturated linear, branched or cyclic alcohols or mixtures thereof, even more preferably C 2-6The organic solvent is selected from saturated linear, branched, or cyclic monohydric alcohols or mixtures thereof (e.g., ethanol, 1-propanol, 2-propanol, butanol, pentanol (including cyclopentanol), or hexanol (including cyclohexanol)) or mixtures thereof, more preferably propanol or mixtures thereof, and most preferably 2-propanol. It is understood that the organic solvent may be a mixture of one or more such alcohol solvents.

[0104] The solvent (B) is preferably a mixture of isopropanol and water, more preferably 40 to 80% by weight of isopropanol and 60 to 20% by weight of water, preferably 50 to 80% by weight of isopropanol and 50 to 20% by weight of water, more preferably 60 to 70% by weight of isopropanol and 40 to 30% by weight of water.

[0105] The coating composition preferably comprises 0.1 to 30 wt% melamine-formaldehyde resin, preferably 1 to 25 wt% melamine-formaldehyde resin, more preferably 3 to 22 wt% aerogel melamine-formaldehyde resin, even more preferably 5 to 20 wt% melamine-formaldehyde resin, even more preferably 10 to 20 wt% melamine-formaldehyde resin, and even more preferably 12 to 18 wt% melamine-formaldehyde resin, based on the total weight of the coating composition.

[0106] The total content of the melamine-formaldehyde resin and the solvent (B) in the coating composition is, based on the total weight of the coating composition, 90% by weight or more, preferably 95% by weight or more, more preferably 97% by weight or more, even more preferably 98% by weight or more, still more preferably 99% by weight or more, most preferably 99.5% by weight or more, and even more preferably 99.8% by weight or more.

[0107] Optionally, the coating composition may include inorganic opacifying agents and / or mineral fillers, such as those described above for the aerogel compositions.

[0108] The step of coating the composite article with the coating composition comprising the melamine-formaldehyde resin may be followed by a step of partially or completely removing the solvent (B), which comprises drying / curing at a temperature of 120-180°C for 1-8 hours.

[0109] The coated composite article preferably contains 0.1 to 20 wt. % melamine resin based on the total weight of the coated composite article, more preferably 0.5 to 18 wt. % melamine resin, and even more preferably 1 to 15 wt. % melamine resin based on the total weight of the coated composite article.

[0110] The thickness of the coated composite article is preferably in the range of 0.1 mm to 500 mm. Generally, it is preferred that the coated composite article have a thickness of 1 to 30 mm.

[0111] The coating weight of the coated composite article is preferably 1 g / m 2 ~2000g / m 2 more preferably in the range of 2 g / m 2 ~1000g / m 2 in the range of 5 g / m 2 ~500g / m 2 and even more preferably in the range of 10 g / m 2 ~300g / m 2 As will be appreciated by those skilled in the art, the coating weight can be readily determined by varying the concentration of the coating composition (particularly the amount of components other than the solvent in the coating composition) and / or the amount of coating composition applied.

[0112] Composite articles obtained by this method The present invention further relates to a composite article obtainable by the method of the present invention. It is understood that the composite article exhibits the properties resulting from the method of the present invention. Accordingly, any of the characteristics described herein with respect to the method of the present invention, including any preferred ranges, also apply with respect to the composite article of the present invention.

[0113] For example, the composite molded article preferably contains 50 to 98 wt % of aerogel based on the total weight of the composite molded article.The thickness of the composite article is preferably in the range of 3 mm to 500 mm.

[0114] It is understood that any known filler may be included in the composite article of the present invention without particular limitation.

[0115] A composite article can be further defined by referring to either its method of manufacture or its properties.

[0116] Therefore, the composite article of the present invention can be defined as comprising aerogel particles and a foam, and the composite article can be obtained by impregnating a foam-containing article with an aerogel composition comprising aerogel powder, an organic solvent (A), and optionally an inorganic opacifying agent and / or a mineral filler, and then partially or completely removing the organic solvent (A) to obtain a composite article. The composite article can also be obtained by injecting, impregnating, or immersing a foam-containing article with an aerogel composition comprising aerogel powder, a melamine-formaldehyde resin, an organic solvent (A), and optionally an inorganic opacifying agent and / or a mineral filler, and then partially or completely removing the organic solvent (A) to obtain a composite molded article. Furthermore, the composite molded article may comprise a coating comprising a melamine resin. The weight of the coating of the composite article is preferably 1 g / m². 2 ~2000g / m 2 more preferably in the range of 2 g / m 2 ~1000g / m 2 in the range of 5 g / m 2 ~500g / m 2 and even more preferably in the range of 10 g / m 2 ~300g / m 2 As will be appreciated by those skilled in the art, the coating weight can be readily determined by varying the concentration of the coating composition (particularly the amount of components other than the solvent in the coating composition) and / or the amount of coating composition applied.

[0117] The composite article preferably contains 0.1 to 20 wt% melamine resin based on the total weight of the composite article, more preferably 0.5 to 18 wt%, and even more preferably 1 to 15 wt% melamine resin based on the total weight of the composite article.

[0118] Additionally or alternatively, a composite article may be defined as comprising aerogel particles and a foam, wherein one or more of the following requirements (i) through (v) are met: (i) the weight ratio of the one or more aerogels to the one or more foams (aerogel / foam) in the composite article is 1:8 or greater; (ii) the composite article has a thermal conductivity at 0°C of 0.030 W / m·K or less. Preferably, the thermal conductivity at 0°C is 0.028 W / m·K or less, more preferably 0.026 W / m·K or less, even more preferably 0.024 W / m·K or less, and even more preferably 0.022 W / m·K or less; (iii) The composite molded article has a thermal conductivity of 0.032 W / m·K or less at 20°C. Preferably, the thermal conductivity at 20°C is 0.030 W / m·K or less, more preferably 0.028 W / m·K or less, even more preferably 0.026 W / m·K or less, and even more preferably 0.024 W / m·K or less; (iv) The composite article has a thermal conductivity at 40°C of 0.034 W / m·K or less. Preferably, the thermal conductivity at 40°C is 0.032 W / m·K or less, more preferably 0.030 W / m·K or less, even more preferably 0.028 W / m·K or less, and even more preferably 0.026 W / m·K or less. (v) The composite article has a burn-through time of at least 10 minutes, the burn-through resistance being determined by treating the composite article in the form of a 16 cm x 16 cm sheet of 8 mm thickness with a propane gas burner (flame source as defined in DIN EN ISO 11925-2 "Ignitionability of products subjected to direct impingement of flame - Part 2: Single flame source test") at the centre of its first major surface, the burn-through time being the time from the start of the flame treatment until the flame reaches the centre of the second major surface.

[0119] The composite article may satisfy one or any number of possible combinations of requirements (i) through (v). For example, the composite article preferably satisfies requirement (i), or requirement (ii), or requirement (iii), or requirement (iv), or requirement (v). Alternatively, it is preferable that the composite article satisfy two requirements, such as (i) and (ii), (ii) and (iii), (iii) and (iv), (iv) and (v), (i) and (iii), (ii) and (iv), (iii) and (v), (i) and (iv), (ii) and (v), or (i) and (v). Alternatively, it is preferred to meet three requirements, such as (i) and (ii) and (iii), (i) and (ii) and (iv), (i) and (ii) and (v), (i) and (iii) and (iv), (i) and (iii) and (v), (i) and (iv) and (v), (ii) and (iii) and (iv), (ii) and (iii) and (v), (ii) and (iv) and (v), or (iii) and (iv) and (v). Alternatively, it is preferred to meet four or all of these requirements.

[0120] The composite article may further comprise a melamine resin. Preferably, at least a portion of the melamine resin is present in the form of a coating. The weight of the coating on the composite article is preferably less than 1 g / m 2 ~2000g / m 2 more preferably in the range of 2 g / m 2 ~1000g / m 2 and even more preferably in the range of 5 g / m 2 ~500g / m 2 and more preferably in the range of 10 g / m 2 ~300g / m 2 As will be appreciated by those skilled in the art, the coating weight can be readily determined by varying the concentration of the coating composition (particularly the amount of components other than the solvent in the coating composition) and / or the amount of coating composition applied.

[0121] The composite article preferably contains 0.1 to 20 wt% melamine resin based on the total weight of the composite article, more preferably 0.5 to 18 wt%, and even more preferably 1 to 15 wt% melamine resin based on the total weight of the composite article.

[0122] It should be understood that composite articles according to these alternative definitions may also further comprise inorganic opacifying agents and / or mineral fillers. The composite article preferably comprises 50-98 wt. %, more preferably 60-96 wt. %, even more preferably 70-95 wt. %, or even 75-95 wt. %, 80-95 wt. %, or 85-95 wt. %, such as 88-92 wt. %, of aerogel, based on the total weight of the composite article. Preferably, the composite article has a thickness in the range of 3 mm to 500 mm, more preferably 3 mm to 100 mm, even more preferably 3 mm to 50 mm, and even more preferably 5 mm to 30 mm. Additionally, where W is the width of the composite article, L is the length of the composite article, and T is the thickness of the composite article, the following requirements are preferably met:

number

[0123] It is understood that the composite articles of the present invention may include additional components, such as, for example, inert fillers or pigments, flame retardants, fire and smoke suppressants, binders, etc., which are preferably added by inclusion in the aerogel composition.

[0124] The composite articles of the present invention may further be coated with a variety of other materials and / or combined with other materials such as, for example, woven fabrics and laminates to form further composites.

[0125] The present invention can be summarized by the following items: 1. A method for preparing a composite article comprising aerogel particles and a foam, the method comprising: providing a foam-containing article comprising a foam; providing an aerogel composition comprising an aerogel powder and an organic solvent (A); combining a foam-containing article with an aerogel composition; Partially or completely removing the organic solvent (A) to obtain a composite article. The present invention comprises:

[0126] 2. A method for preparing a composite article according to item 1, wherein the composite article further comprises an inorganic opacifying agent and / or a mineral filler, and the step of providing an aerogel composition comprising an aerogel powder and an organic solvent (A) is a step of providing an aerogel composition comprising an aerogel powder, an organic solvent (A), and an inorganic opacifying agent and / or a mineral filler.

[0127] 3. The method for preparing a composite article according to item 1 or 2, wherein the foam-containing article is a foam sheet.

[0128] 4. The foam-containing article has a compressive strength of 2 to 300 kg / m 3 , preferably 5 to 200 kg / m 3 , more preferably 6 to 150 kg / m 3 4. The method for preparing a composite article according to any one of items 1 to 3, wherein the composite article has a density of

[0129] 5. A method for preparing a composite article according to any one of the preceding items, wherein the open cell percentage of the foam is 50% or more, preferably 60-99%, in particular 85-95% or 90-99%, and the open cell percentage of the foam is preferably 40-99%, determined according to ASTM D2856.

[0130] 6. The method for preparing a composite article according to any one of the preceding items, wherein the foam comprises one or more selected from polyurethane foam, polyisocyanurate foam, melamine foam, phenolic foam, chemically crosslinked polyolefin foam, polypropylene foam, and mixtures thereof.

[0131] 7. A method for preparing a composite article according to any one of the preceding items, wherein the foam comprises one or more selected from polyurethane (PUR) foam, melamine foam, and phenolic foam.

[0132] 8. A method for preparing a composite article according to any one of the preceding items, wherein the foam comprises melamine foam.

[0133] 9. A method for preparing a composite article according to any one of the preceding items, wherein the foam is chemically and / or physically crosslinked.

[0134] 10. The organic solvent (A) is a hydrocarbon solvent, preferably C 3-16 selected from saturated, unsaturated or partially saturated hydrocarbons or mixtures thereof, more preferably C 3-10 selected from saturated linear or branched or cyclic hydrocarbons or mixtures thereof, more preferably C 3-10 selected from linear or branched alkanes or mixtures thereof, even more preferably C 3-10 selected from linear or branched alkanes or mixtures thereof, even more preferably C 5-7 3. A method for preparing a composite article according to any one of the preceding items, wherein the alkane is selected from a linear or branched alkane or a mixture thereof, even more preferably selected from hexane or heptane or a mixture thereof, and most preferably n-hexane.

[0135] 11. The organic solvent (A) is an alcohol solvent, preferably C 2-12 is selected from saturated, unsaturated or partially saturated alcohols or mixtures thereof, more preferably C 2-12is selected from saturated linear, branched or cyclic alcohols or mixtures thereof, more preferably C 2-12 is selected from saturated linear, branched or cyclic monohydric alcohols or mixtures thereof, and even more preferably C 2-6 10. The process for preparing a composite article according to any one of the preceding claims, wherein the alcohol is selected from saturated linear, branched or cyclic monohydric alcohols or mixtures thereof, even more preferably selected from propanol or mixtures thereof, most preferably 2-propanol.

[0136] 12. The method for preparing a composite article according to any one of the preceding items, wherein the aerogel comprises or consists of one or more selected from silicon oxide, aluminum oxide, zirconium oxide, titanium oxide, hafnium oxide, and yttrium oxide, preferably the aerogel comprises or consists of silicon oxide, and more preferably the aerogel is a silica aerogel.

[0137] 13. A method for preparing a composite article according to any one of the preceding items, wherein the aerogel has a porosity of 85% or more, more preferably 90% or more, as determined by isothermal adsorption and desorption.

[0138] 14. The aerogel has a specific surface area of ​​300 m2, determined according to DIN ISO 9277 2003-05 (Determination of the specific surface area of ​​solids by gas adsorption using the BET method). 2 / g or more, preferably 400m 2 / g or more, preferably 500m 2 / g or more, preferably 600m 2 / g or more, and preferably 2000m 2 / g or less, more preferably 1500m 2 / g or less, and even more preferably 1000m 2 A method for preparing a composite article according to any one of the preceding items, having a specific surface area of ​​0.15 wt. sq. / g or less.

[0139] 15. A method for preparing a composite article according to any one of the preceding items, wherein the powder of the aerogel has a median particle size (d50) in the range of 1 to 50 μm, preferably 5 to 40 μm, more preferably 10 to 30 μm, and even more preferably 15 to 25 μm, as measured by laser diffraction, preferably using a Malvern Mastersizer.

[0140] 16. A method for preparing a composite article according to any one of the preceding items, wherein the powder of the aerogel is obtained from a heterophase reaction.

[0141] 17. The method for preparing a composite article according to any one of the preceding items, wherein the aerogel powder is obtained by mixing and reacting deionized water, water glass, an organosilane compound, an inorganic acid, and an organic solvent, preferably a non-polar organic solvent, to obtain silica hydrogel primary particles, thereby solvent-substituting the silica hydrogel primary particles, and drying the gel particles after the solvent substitution under normal pressure, preferably without further grinding and sieving treatments.

[0142] 18. A method for preparing a composite article according to any one of items 1 or 3 to 17, wherein the aerogel composition is a dispersion of the aerogel powder in the organic solvent (A).

[0143] 19. A method for preparing a composite article according to any one of items 1 and 3 to 18, wherein the aerogel composition contains, based on the total weight of the aerogel composition, 2 to 20% by weight of aerogel, preferably 4 to 18% by weight of aerogel, more preferably 6 to 18% by weight of aerogel, and even more preferably 10 to 18% by weight of aerogel, and the remainder is preferably the organic solvent (A).

[0144] 20. A method for preparing a composite article according to any one of items 1 and 3 to 19, wherein the total content of the aerogel powder and the organic solvent (A) in the aerogel composition is 90% by weight or more, preferably 95% by weight or more, more preferably 97% by weight or more, even more preferably 98% by weight or more, still more preferably 99% by weight or more, most preferably 99.5% by weight or more, or even more preferably 99.8% by weight or more.

[0145] 21. The method for preparing a composite article according to any one of items 2 to 17, wherein the aerogel composition is a dispersion of the aerogel powder, an inorganic opacifying agent and / or a mineral filler in the organic solvent (A).

[0146] 22. The method for preparing a composite article according to any one of items 2 to 17 and 21, wherein the inorganic opacifying agent comprises or consists of one or more selected from iron oxide, zirconium oxide, titanium oxide, silicon carbide, and graphite, preferably the inorganic opacifying agent comprises or consists of one or more selected from iron oxide, zirconium oxide, and silicon carbide, more preferably the inorganic opacifying agent is iron oxide or silicon carbide.

[0147] 23. A method for preparing a composite article according to any one of items 2 to 17, 21 and 22, wherein the mineral filler comprises or consists of one or more selected from metal hydroxides and hydrated carbonates, preferably, the mineral filler comprises or consists of one or more selected from aluminum hydroxide, magnesium hydroxide, hydromagnesite and hydrocalcite, more preferably, the mineral filler is one or both selected from magnesium dihydroxide and aluminum trihydroxide.

[0148] 24. A method for preparing a composite article according to any one of Items 2 to 17 and 21 to 23, wherein the aerogel composition contains 2 to 20 wt. % aerogel, preferably 4 to 18 wt. % aerogel, more preferably 6 to 18 wt. % aerogel, and even more preferably 10 to 18 wt. % aerogel, based on the total weight of the aerogel composition, and the remainder is preferably the organic solvent (A), the inorganic opacifying agent, and the mineral filler.

[0149] 25. The method for preparing a composite article according to any one of items 2 to 17 and 21 to 24, wherein the total content of the aerogel powder and the organic solvent (A) in the aerogel composition is 50% by weight or more, preferably 75% by weight or more, and more preferably 85% by weight or more.

[0150] 26. A method for preparing a composite article according to any one of items 2 to 17 and 21 to 25, wherein the total content of the inorganic opacifying agent and the mineral filler in the aerogel composition is 50% by weight or less, preferably 25% by weight or less, more preferably 15% by weight or less.

[0151] 27. The method for preparing a composite article according to any one of the preceding items, wherein the aerogel composition comprises aerogel powder, a melamine-formaldehyde resin, and an organic solvent.

[0152] 28. A method for preparing a composite article according to item 27, wherein the aerogel composition is a dispersion of aerogel powder and melamine-formaldehyde resin in an organic solvent.

[0153] 29. A method for preparing a composite article according to Item 27 or 28, wherein the aerogel composition comprises, based on the total weight of the aerogel composition, 2 to 20 wt. % aerogel, preferably 4 to 15 wt. % aerogel, more preferably 5 to 12 wt. % aerogel, even more preferably 6 to 10 wt. % aerogel, and 0.1 to 20 wt. % melamine-formaldehyde resin, preferably 0.1 to 10 wt. % melamine-formaldehyde resin, more preferably 0.5 to 8 wt. % aerogel melamine-formaldehyde resin, even more preferably 1 to 7 wt. % melamine-formaldehyde resin, based on the total weight of the aerogel composition, and the remainder is preferably an organic solvent.

[0154] 30. The method for preparing a composite article according to any one of Items 27 to 29, wherein the total content of the aerogel powder, melamine-formaldehyde resin, and organic solvent in the aerogel composition is 90% by weight or more, preferably 95% by weight or more, more preferably 97% by weight or more, even more preferably 98% by weight or more, still more preferably 99% by weight or more, most preferably 99.5% by weight or more, and even more preferably 99.8% by weight or more.

[0155] 31. A method for preparing a composite article according to any one of items 27 to 30, wherein the aerogel composition is a dispersion of aerogel powder, melamine-formaldehyde resin, inorganic opacifying agent and / or mineral filler in the organic solvent.

[0156] 32. A method for preparing a composite article according to any one of Items 27 to 31, wherein the inorganic opacifying agent comprises or consists of one or more selected from iron oxide, zirconium oxide, titanium oxide, silicon carbide, and graphite, preferably the inorganic opacifying agent comprises or consists of one or more selected from iron oxide, zirconium oxide, and silicon carbide, more preferably the inorganic opacifying agent is iron oxide or silicon carbide.

[0157] 33. A method for preparing a composite article according to any one of items 27 to 32, wherein the mineral filler comprises or consists of one or more selected from metal hydroxides and hydrated carbonates, preferably comprises or consists of one or more selected from aluminum hydroxide, magnesium hydroxide, hydromagnesite and hydrocalcite, more preferably one or both selected from magnesium dihydroxide and aluminum trihydroxide.

[0158] 34. A method for preparing a composite article according to any one of Items 27 to 33, wherein the aerogel composition comprises, based on the total weight of the aerogel composition, 2 to 20 wt. % aerogel, preferably 4 to 15 wt. % aerogel, more preferably 5 to 12 wt. % aerogel, even more preferably 6 to 10 wt. % aerogel, and 0.1 to 20 wt. % melamine-formaldehyde resin, preferably 0.1 to 10 wt. % melamine-formaldehyde resin, more preferably 0.5 to 8 wt. % aerogel melamine-formaldehyde resin, even more preferably 1 to 7 wt. % melamine-formaldehyde resin, based on the total weight of the aerogel composition, with the remainder preferably being organic solvent, inorganic opacifying agent, and mineral filler.

[0159] 35. A method for preparing a composite article according to any one of Items 27 to 34, wherein the total content of the aerogel powder, the melamine-formaldehyde resin, and the organic solvent in the aerogel composition is 50% by weight or more, preferably 75% by weight or more, and more preferably 85% by weight or more.

[0160] 36. A method for preparing a composite article according to any one of items 27 to 35, wherein the total content of the inorganic opacifying agent and the mineral filler in the aerogel composition is 50% by weight or less, preferably 25% by weight or less, more preferably 15% by weight or less.

[0161] 37. A method for preparing a composite article according to any one of the preceding items, wherein the foam-containing article and the aerogel composition are combined by impregnating the foam-containing article with the aerogel composition.

[0162] 38. A method for preparing a composite article according to any one of the preceding items, wherein partially or completely removing the organic solvent (A) by drying to obtain the composite article comprises drying at a temperature of 50°C to 150°C for 1 hour to 8 hours, preferably at 100°C to 120°C for 1 hour to 48 hours.

[0163] 39. A method for preparing a composite article according to any one of the preceding items, wherein the composite article comprises 50 to 98 wt. %, preferably 60 to 96 wt. %, and more preferably 70 to 95 wt. % aerogel, based on the total weight of the composite article.

[0164] 40. A method for preparing a composite article according to any one of the preceding items, further comprising the step of coating the composite article with a coating composition comprising a melamine-formaldehyde resin.

[0165] 41. A method for preparing a composite article according to the preceding item, wherein the step of coating the composite article with a coating composition comprising a melamine-formaldehyde resin is carried out by spraying the coating composition onto the composite article to be coated.

[0166] 42. A method for preparing a composite article according to item 40 or 41, wherein the coating composition comprises a melamine-formaldehyde resin and a solvent (B), and the solvent (B) preferably comprises an organic solvent and water.

[0167] 43. The method for preparing a composite article according to the preceding paragraph, wherein the organic solvent in solvent (B) is an alcohol solvent (containing one or more alcohols), preferably C 2-12 is selected from saturated, unsaturated or partially saturated alcohols or mixtures thereof, more preferably C 2-12is selected from saturated linear, branched or cyclic alcohols or mixtures thereof, more preferably C 2-12 is selected from saturated linear, branched or cyclic monohydric alcohols or mixtures thereof, even more preferably C (such as, for example, ethanol, 1-propanol, 2-propanol, butanol, pentanol (including cyclopentanol) or hexanol (including cyclohexanol)). 2-6 The process according to claim 1, wherein the alcohol is selected from saturated linear, branched or cyclic monohydric alcohols or mixtures thereof, even more preferably selected from propanol or mixtures thereof, most preferably 2-propanol.

[0168] 44. The method for preparing a composite article according to item 42, wherein the solvent (B) is a mixture of isopropanol and water, preferably containing 40 to 80% by weight of isopropanol and 60 to 20% by weight of water, preferably 50 to 80% by weight of isopropanol and 50 to 20% by weight of water, more preferably 60 to 70% by weight of isopropanol and 40 to 30% by weight of water.

[0169] 45. A method for preparing a composite article according to any one of items 40 to 44, wherein the coating composition preferably comprises, based on the total weight of the coating composition, 0.1 to 30 wt. % of the melamine-formaldehyde resin, preferably 1 to 25 wt. % of the melamine-formaldehyde resin, more preferably 3 to 22 wt. % of the aerogel melamine-formaldehyde resin. Preferably, the coating composition comprises 3 to 22 wt. % of the melamine-formaldehyde resin, even more preferably 5 to 20 wt. % of the melamine-formaldehyde resin, even more preferably 10 to 20 wt. % of the melamine-formaldehyde resin, even more preferably 12 to 18 wt. % of the melamine-formaldehyde resin.

[0170] 46. ​​A method for preparing a composite article according to any one of Items 40 to 45, wherein the total content of the melamine-formaldehyde resin and the solvent (B) in the coating composition is 90% by weight or more, preferably 95% by weight or more, more preferably 97% by weight or more, even more preferably 98% by weight or more, still more preferably 99% by weight or more, most preferably 99.5% by weight or more, and even more preferably 99.8% by weight or more, based on the total weight of the coating composition.

[0171] 47. A method for preparing a composite article according to any one of items 40 to 46, wherein the step of coating the composite article with a coating composition comprising a melamine-formaldehyde resin is followed by a step of heating to a temperature of at least 100°C for at least 10 minutes (preferably 1 hour), preferably at a temperature of 120 to 180°C for 1 to 8 hours.

[0172] 48. A method for preparing a composite article according to any one of items 40 to 47, wherein the composite article comprises 15 to 70 wt %, preferably 20 to 60 wt %, more preferably 30 to 50 wt %, of aerogel, based on the total weight of the composite article, and 0.1 to 20 wt %, preferably 0.5 to 18 wt %, more preferably 1 to 15 wt %, of melamine resin, based on the total weight of the composite article.

[0173] 49. A method for preparing a composite article according to any one of the preceding items, wherein the composite article has a thickness in the range of 3 mm to 500 mm, preferably in the range of 3 to 100 mm, more preferably in the range of 3 to 50 mm, and even more preferably in the range of 5 to 30 mm.

[0174] 50. If the width of the composite article is W, the length of the composite article is L, and the thickness of the composite article is T, then:

number

[0175] 51. A method for preparing a composite article according to any one of the preceding items, wherein the composite article comprises less than 15% by weight of organic compounds other than melamine resin and foam materials, preferably less than 10% by weight of organic compounds other than melamine resin and foam materials, more preferably less than 5% by weight of organic compounds other than melamine resin and foam materials, the term organic compounds relating to any compound containing at least one carbon-hydrogen bond.

[0176] 52. A method for preparing a composite article according to any one of the preceding items, wherein the composite article comprises less than 10% by weight of binder, preferably less than 5% by weight of binder, more preferably less than 2% by weight of binder, even more preferably less than 1% by weight of binder, even more preferably less than 0.5% by weight of binder, and most preferably less than 0.1% by weight of binder.

[0177] 53. A composite article obtainable by the method according to any one of the preceding paragraphs.

[0178] 54. A composite molded article comprising aerogel particles and a foam, characterized in that the composite article is obtained by injecting, impregnating or immersing a foam-containing molded article made of a foam with an aerogel composition comprising aerogel powder and an organic solvent (A), and optionally containing an inorganic opacifying agent and / or a mineral filler, and then partially or completely removing the organic solvent (A) to obtain the composite molded article.

[0179] 55. A composite article according to item 54, wherein the composite article can be obtained by injecting, impregnating, or immersing an aerogel composition comprising an aerogel powder, a melamine-formaldehyde resin, and an organic solvent (A), as well as an optional inorganic opacifying agent and / or mineral filler, into a foam-containing article comprising a foam, and partially or completely removing the organic solvent (A) to obtain the composite article.

[0180] 56. The composite article of item 54 or 55, wherein the composite article further comprises a coating comprising a melamine resin.

[0181] 57. A composite molded article containing aerogel particles and a foam, which meets the following requirements (i) to (v): (i) the weight ratio of the one or more aerogels to the one or more foams in the composite article (aerogel / foam) is 1:8 or greater; (ii) the composite article has a thermal conductivity at 0°C of 0.030 W / m·K or less. Preferably, the thermal conductivity at 0°C is 0.028 W / m·K or less, more preferably 0.026 W / m·K or less, even more preferably 0.024 W / m·K or less, and even more preferably 0.022 W / m·K or less; (iii) the composite article has a thermal conductivity at 20°C of 0.032 W / m·K or less. Preferably, the thermal conductivity at 20°C is 0.030 W / m·K or less, more preferably 0.028 W / m·K or less, even more preferably 0.026 W / m·K or less, and even more preferably 0.024 W / m·K or less; (iv) The composite article has a thermal conductivity of 0.034 W / m K or less at 40°C. Preferably, the thermal conductivity at 40°C is 0.032 W / m K or less, more preferably 0.030 W / m K or less, even more preferably 0.028 W / m K or less, and even more preferably 0.026 W / m K or less. (v) the composite article has a burn-through time of 10 minutes or more, the burn-through resistance being determined by treating the composite article in the form of a 16 cm x 16 cm sheet of 8 mm thickness with a propane gas burner (a flame source as defined in DIN EN ISO 11925-2 "Ignitionability of products subjected to direct impingement of flame - Part 2: Single flame source test") at the center of its first major surface, the burn-through time being the time from the start of the flame treatment until the flame reaches the center of the second major surface. A composite article that satisfies one or more of the following conditions.

[0182] 58. The composite article of item 57, further comprising an inorganic opacifying agent and / or a mineral filler.

[0183] 59. The composite article of item 58, wherein the composite article further comprises a melamine resin.

[0184] 60. The composite article of item 59, wherein at least a portion of the melamine resin is present in the form of a coating.

[0185] 61. The composite article according to any one of items 57 to 60, wherein the composite article comprises less than 15% by weight of organic compounds other than melamine resin and foam materials, preferably less than 10% by weight of organic compounds other than melamine resin and foam materials, more preferably less than 5% by weight of organic compounds other than melamine resin and foam materials, the term organic compounds relating to any compounds containing at least one carbon-hydrogen bond.

[0186] 62. The composite article according to any one of items 57 to 61, wherein the composite article comprises less than 10% by weight of binder, preferably less than 5% by weight of binder, more preferably less than 2% by weight of binder, even more preferably less than 1% by weight of binder, even more preferably less than 0.5% by weight of binder, and most preferably less than 0.1% by weight of binder.

[0187] 63. The composite article according to any one of items 57 to 62, wherein the composite article comprises 50 to 98 wt. %, preferably 60 to 96 wt. %, more preferably 70 to 95 wt. % aerogel, based on the total weight of the composite article.

[0188] 64. The composite article according to any one of items 57 to 63, wherein the composite article has a thickness in the range of 3 mm to 500 mm, preferably in the range of 3 mm to 100 mm, more preferably in the range of 3 mm to 50 mm, and even more preferably in the range of 5 mm to 30 mm.

[0189] 65. If the width of the composite article is W, the length of the composite article is L, and the thickness of the composite article is T, then the following requirements apply:

number

[0190] Example 1 material Aerogel powder (JIOS AeroVa aerogel powder, D20 grade) Melamine open-cell foam (Basotect B, manufactured by BASF), thickness 8mm, 14mm, 25mm, density 9kg / m 3 n-Hexane (technical grade) 2-Propanol (Technical Grade)

[0191] experiment The aerogel was dispersed in 2-propanol or n-hexane using a standard laboratory mixing device, more specifically a propeller mixer (Heidolph RZR2020 overhead stirrer), to a solids concentration of 10-14 wt %.

[0192] Melamine open-cell foam (Basotect B, BASF) with thicknesses of 8, 14, and 25 mm was treated as described above by pouring the aerogel dispersion onto the substrate until saturated, followed by drying to remove the carrier solvent, resulting in aerogel-filled foams with aerogel contents of over 90 wt%:

[0193] [Table 2]

[0194] [Table 3]

[0195] Results and Evaluation The main features of these filled foams were low thermal conductivity and low dust generation. Furthermore, the flexibility of the filled foams was surprisingly high, almost equivalent to that of unfilled foams. The filled foams were also easy to cut and handle, and had a density of approximately 100 kg / m. 3 was very low.

[0196] The foam was self-extinguishing upon direct contact with flame, and exhibited improved fire behavior over the unfilled foam.

[0197] Characterization results and photographs of these prototypes are shown in the included figures as follows: FIG. 1: Thermal conductivity values ​​of Comparative Example 1 and Examples 1 to 3 Figure 2: Photographs of Examples 2, 4 and 5 Figure 3: The filled foam exhibits surprisingly high flexibility (Figure 3b), with little difference from the reference unfilled foam (Figure 3a) (Example 4). No significant dusting was observed when the filled foam samples were bent: Figure 4: Micrographs of Example 2 show the high degree of filling and aerogel aggregation behavior (Figure 4b) relative to the unfilled reference (Figure 4a): Figure 5: Photograph taken after direct flame exposure of Example 2. The filled foam significantly inhibits flame penetration, with no combustion occurring after 10 minutes of direct flame exposure: 5a and 5c: Unfilled foam (Comparative Example 1): Burn-through after direct flame exposure (5a: flame-impacted side, 5c: unexposed side). Figures 5b and 5d: Filled foam (Example 2): No burn-through even after 10 minutes (5b: flame-exposed side, 5d: unexposed side).

[0198] 2. Conducting analyses and tests 2.1 Microscopic Imaging The specimens were observed for surface morphology using an Olympus SZX7 stereomicroscope equipped with an Olympus DF Plapo 1x-4 objective.

[0199] 2.2 Fire resistance test To test the fire resistance, specimens were exposed to a direct flame: they were cut to a size of 16 x 16 cm and exposed to a burner in a Euro Class E fire test (DIN EN ISO 11925-2) using commercially available propane gas with a purity of at least 95% and a gas pressure between 10 kPa and 50 kPa.

[0200] 2.3 Thermal conductivity The thermal conductivity was measured by the heat flow meter method using a LaserComp Fox 200 in accordance with standard DIN EN 12667. Test specimens were cut to a size of 20 x 20 cm, and the thermal conductivity results were recorded at 0°C, 10°C, 20°C, and 40°C.

Claims

1. 1. A method for preparing a composite article comprising aerogel particles and a foam, comprising: providing a foam-containing article comprising a foam; providing an aerogel composition comprising an aerogel powder and an organic solvent (A); mixing the foam-containing article with the aerogel composition; partially or completely removing said organic solvent (A) to obtain said composite article; The method comprising:

2. The foam-containing article has a viscosity of 2 to 300 kg / m ３ , preferably 5 to 200 kg / m ３ , more preferably 6 to 150 kg / m ３ 10. The method for preparing the composite article of claim 1, wherein the composite article has a density of

3. 3. A method for preparing a composite article according to claim 1 or 2, wherein the open cell fraction of the foam is 50% or more, preferably 60-99%, in particular 85-95% or 90-99%.

4. 4. The method for preparing a composite article according to any one of claims 1 to 3, wherein the foam comprises one or more selected from polyurethane foam, polyisocyanurate foam, melamine foam, phenolic foam, chemically crosslinked polyolefin foam, polypropylene foam, and mixtures thereof.

5. The method for preparing a composite article according to any one of claims 1 to 4, wherein the foam comprises melamine foam.

6. 6. The method for preparing a composite article according to any one of claims 1 to 5, wherein the aerogel composition comprises 2 to 20 wt. % aerogel, preferably 4 to 18 wt. % aerogel, more preferably 6 to 18 wt. % aerogel, even more preferably 10 to 18 wt. % aerogel, based on the total weight of the aerogel composition, the remainder being preferably the organic solvent (A).

7. The method for preparing a composite article according to any one of claims 1 to 6, wherein the aerogel composition comprises aerogel powder, a melamine-formaldehyde resin, and an organic solvent.

8. 8. The method for preparing a composite article according to any one of claims 1 to 7, wherein the foam-containing article and the aerogel composition are combined by impregnating the foam-containing article with the aerogel composition.

9. The method for preparing a composite article according to any one of claims 1 to 8, wherein partially or completely removing the organic solvent (A) and drying to obtain the composite article comprises drying at 50 to 150°C for 1 to 48 hours, preferably drying at 100 to 120°C for 1 to 48 hours.

10. A method for preparing a composite article according to any one of claims 1 to 9, further comprising the step of coating the composite article with a coating composition comprising a melamine-formaldehyde resin.

11. A composite article obtainable by the method according to any one of claims 1 to 10.

12. One or more of the following requirements (i) to (v): (i) the weight ratio of said one or more aerogels to said one or more foams (aerogel / foam) in said composite article is 1:8 or higher; (ii) the composite article has a thermal conductivity at 0°C of 0.030 W / m K or less. Preferably, the thermal conductivity at 0°C is 0.028 W / m K or less, more preferably 0.026 W / m K or less, even more preferably 0.024 W / m K or less, and even more preferably 0.022 W / m K or less; (iii) the composite article has a thermal conductivity at 20°C of 0.032 W / m K or less. Preferably, the thermal conductivity at 20°C is 0.030 W / m K or less, more preferably 0.028 W / m K or less, even more preferably 0.026 W / m K or less, and even more preferably 0.024 W / m K or less; (iv) the composite article has a thermal conductivity at 40°C that is 0.034 W / m K or less. Preferably, the thermal conductivity at 40°C is 0.032 W / m K or less, more preferably 0.030 W / m K or less, even more preferably 0.028 W / m K or less, and even more preferably 0.026 W / m K or less; (v) the composite article has a burn-through time of 10 minutes or more, the burn-through resistance being determined by using the composite article in the form of a 16 cm x 16 cm sheet of 8 mm thickness and treating the composite article at the center of its first major surface with a propane gas burner (flame source as defined in DIN EN ISO 11925-2 "Ignition properties of products subjected to direct impingement of flame - Part 2: Single flame source test"), the burn-through time being the time from the start of the flame treatment until the flame reaches the center of the second major surface. A composite article comprising aerogel particles and a foam, wherein the aerogel particles and the foam are filled with a

13. 13. The composite article of claim 11 or 12, comprising 0.1 to 20 wt. % melamine resin, based on the total weight of the composite article.

Images