CN1104393C - Fibre-containing aerogel composite material - Google Patents

Abstract

The present invention relates to a composite material containing 5-97% (volume) airgel particles, at least one binder and at least one fibrous material, wherein the particle size of the airgel particles is ≥ 0.5 mm, and its preparation method and its application.

Description

Fiber-containing airgel composite material, its production method and application, and the obtained molded body

The present invention relates to a kind of composite material, contains 5-97% (volume) airgel particle, at least one binding agent and at least one kind of fibrous material, wherein the particle diameter of airgel particle ≥ 0.5mm, the present invention also relates to Its preparation method and application.

Aerogels, especially those with a porosity of more than 60% and a density of less than 0.4 g/ ^cm3 , have particularly low thermal conductivity due to their very low density, high porosity and small pore size, and thus can be used as Thermal insulation material as described in EP-A-0 171722.

High porosity can also lead to reduced mechanical stability, not only for the gel dried into an aerogel, but also for the dried aerogel itself.

Aerogels in the general sense, ie "gels with air as dispersant", are obtained by drying suitable gels. In this sense, the concept of "aerogel" includes narrowly defined aerogels, xerogels and cryogels. Wherein when the gel liquid is substantially removed at a temperature above the critical temperature and from a pressure above the critical pressure, the dried gel is called an aerogel in the narrow sense. In contrast, if the gelling liquid is removed under subcritical conditions, such as in the formation of a liquid-vapor-interface phase, the gel formed is called a xerogel. The concept of airgel used in this application refers to aerogel in a broad sense, that is, "a gel using air as a dispersant".

The forming process of airgel ends at the sol-gel transition. Once the solid gel structure is formed, its shape can only be changed by comminuting, eg grinding. The material is brittle under other forms of stress.

For many applications, it is necessary to use aerogels with specific object shapes. The shaped bodies can in principle already be produced during the gel preparation. However, a diffusion-determined solvent exchange (for aerogels: see for example US-A-4610963 and EP-A0396076, for airgel composites: see for example WO93/06044) and likewise a diffusion-determined Drying leads to an uneconomical extension of the production cycle. It is therefore expedient to carry out a shaping step after the airgel has been produced, ie after drying, but essentially no application-related changes to the internal structure of the airgel take place.

For many applications, insulating materials are required to have good insulation against airborne sound in addition to good thermal insulation properties. In general, porous materials with macroscopic (>0.1 μ) porosity have good sound insulation properties because the speed wave of sound is damped by the friction between air and pore walls. Therefore, monolithic materials without macroscopic porosity have only extremely low sound insulation properties. If a material is only microscopically porous, such as monolithic airgel, air cannot flow through the pores, but instead the sound waves are transmitted to the material structure, which transmits the sound waves further without strong attenuation.

DE-A 3346180 describes bending-resistant panels based on extrusions of silicic acid aerogels obtained by flame pyrolysis combined with long inorganic fiber reinforcements. The silicic acid airgel obtained by flame pyrolysis is not the airgel in the above meaning, because it is not obtained by gel drying, and thus has a completely different microporous structure. It is mechanically stable so that it can be squeezed without destroying the microstructure, but its thermal conductivity is higher than that of typical aerogels in the above sense. The surface of these extrusions is so easily damaged that it must be hardened with an adhesive or protected by a film coating.

EP-A-0340707 discloses an insulating material with a density of 0.1-0.4 g/cm ³ consisting of at least 50% (by volume) of silica-aerogel-particles with a diameter of 0.5-5 mm, by means of at least one organic and/or inorganic binders. If the airgel particles are only bonded to the contact surfaces by means of an adhesive, the resulting insulating material is not particularly stable mechanically, since the part of the airgel particles covered by the adhesive will rupture under mechanical stress, The particles no longer adhere to it, and cracks appear in the insulation. Therefore, as far as possible all wedges between the airgel particles should be filled with binder. When the binder content is very low, the resulting material, while more stable than pure aerogels, is prone to cracking when all the particles are not sufficiently enclosed by the binder. Although favorable for reducing the thermal conductivity at high airgel volume fractions, only a small volume of the wedge remains for the binder, which leads to mechanical stability especially when using porous binders with very low thermal conductivity such as foams very bad. Filling all wedges with binder also drastically reduces the acoustic properties of the material due to reduced macro porosity (between particles).

EP-A-489319 discloses a foam composite material with low thermal conductivity, which contains 20-80% (volume) of silica-aerogel-particles, 20-80% (volume) of surrounding airgel particles and interconnected Styrene polymer foam material having a density of 0.01-0.15 g/cm ³ and, if necessary, effective amounts of conventional additives. The resulting foam-bonded material, while resistant to compression, is less resistant to bending at high concentrations of airgel particles.

German patent applications DE-A-4430669 and DE-A-4430642 describe fiber-reinforced airgel sheets or mats. Due to the high airgel content, these plates or mats have low thermal conductivity, but require long manufacturing cycles to manufacture due to the aforementioned diffusion issues.

In the as yet unpublished German patent application P4445771.5 a fibrous web-aerogel composite material is known, which has at least one layer of fibrous web and airgel particles, characterized in that the fibrous web contains at least one bicomponent The fiber material is bonded between the fibers and between the fibers and the airgel particles through a shell material with a low melting point. The composite material has low thermal conductivity and high macro-level porosity, resulting in good sound insulation properties, but due to the use of bicomponent fibers, the temperature range and fire rating of the material are limited. In addition, corresponding composite materials, especially complex shaped bodies, cannot be produced easily.

It is therefore the object of the present invention to provide a composite material based on airgel particles which has low thermal conductivity, is mechanically stable and is easy to manufacture.

A further object of the present invention is to provide a composite material based on airgel particles which also has good sound insulation properties.

This task is achieved by a composite material containing 5-97% by volume of airgel particles, at least one binder and at least one fiber material, wherein the particle size of the airgel particles is ≥ 0.5 mm.

The binder either bonds the fibers or aerogels to each other or acts as a matrix material in which the fibers and airgel particles are embedded. The fibers and airgel particles are bonded to one another and optionally embedded in a binder matrix via a binder, resulting in a mechanically stable material with low thermal conductivity.

Compared with materials composed only of airgel particles, bonded by the surface or embedded in the binder matrix, the extremely low volume content of the fiber can greatly improve the mechanical strength under the condition of constant volume content of the binder, because They carry the major part of the load. If a higher volume fraction of fibers and a small amount of binder is used, a porous material can be obtained in which the binder-bonded fibers form a mechanically stable framework into which the airgel particles are embedded. The pores thus formed result in a high porosity and better sound insulation.

The fibers may be natural or synthetic, inorganic or organic, such as cellulose fibers, cotton or flax fibers, glass or mineral fibers, polyester fibers, polyamide fibers, or aramid fibers. These fibers can be new or generated from waste materials such as cullet waste or scrap. Bicomponent fibers can also be used.

The fibers may be smooth or rugose individual filaments, tows, or webs or fabrics. The fibrous web and/or fibrous fabric may be included in the composite material as a unitary piece joined together and/or in a plurality of small pieces.

The fibers may have a circular, trilobal, pentalobal, oktalobal, ribbon, Christmas tree, dumbbell or other star shaped cross-section. Hollow fibers can also be used.

The diameter of the fibers used in the composite is preferably smaller than the average diameter of the airgel particles in order to be able to bind a high content of airgel in the composite. By choosing very fine fibers, the composite can be made to bend easily.

Preference is given to using fibers with a diameter between 1 μ and 1 mm. For a fixed volume content of fibers, the use of smaller diameter fibers generally results in fracture-resistant composites.

The length of the fibers is not limited in any way. However, it is preferably larger than the mean diameter of the airgel particles, that is to say at least 0.5 mm.

Mixtures of the aforementioned types can also be used.

The stability and thermal conductivity of the composites increase with increasing fiber content. According to the specific application, the volume content of fibers is preferably 0.1-40% (volume), particularly preferably 0.1-15% (volume).

In order to improve the bonding of the fibers to the matrix, it is generally also possible to coat eg glass fibers with binders or coupling agents.

Aerogels suitable for use in the composites of the invention are aerogels based on metal oxides suitable for the sol-gel industry (see for example CJ Brinker, GWScherer, Sol-Gel-Science [sol-gel science], 1990, Chapters 2 and 3), such as Si or Al compounds, or aerogels based on organics suitable for the sol-gel-industry, such as melamine-formaldehyde condensates (US-A-5086085) or m-phthalamide Phenolic formaldehyde condensates (US-A-4873218). They can also be based on mixtures of the aforementioned materials. Preference is given to using aerogels containing Si compounds, particular preference to using aerogels containing SiO ₂ , in particular optionally organically modified SiO ₂ aerogels.

To reduce the effect of radiation on thermal conductivity, the airgel may contain infrared opacifiers such as carbon black, titanium dioxide, iron oxide, zirconium dioxide or mixtures thereof.

In addition, the thermal conductivity of airgel decreases with increasing porosity and decreasing density until the density is 0.1 g/ ^cm3 . For this reason, aerogels with a porosity greater than 60% and a density of 0.1-0.4 g/ ^cm3 are preferred. The thermal conductivity of the airgel particles is preferably less than 40 mW/mK, particularly preferably less than 25 mW/mK.

In a preferred embodiment, hydrophobic airgel particles are used, which are obtained by introducing hydrophobic surface groups on the microporous surface of the airgel during or after the preparation of the airgel.

The concept "airgel particle" refers in the present invention to a monolithic particle consisting of one piece, or a particle comprising airgel particles having a substantially smaller diameter than the particle diameter, which are bonded and/or Or become larger particles by extrusion.

The particle size is related to the application of the material. In order to achieve high stability, the particles should not be too coarse, the diameter of the particles is preferably less than 1 cm, particularly preferably less than 5 mm.

On the other hand, the diameter of the airgel particles should be greater than 0.5 mm to avoid difficulties encountered in handling low-density very fine powders during fabrication. In addition, liquid binders usually penetrate into the upper layer of the airgel during processing, so that the airgel loses its high insulating properties in this region. Therefore, the ratio of macroscopic particle surface to particle volume should be as small as possible, but this cannot be done if the particles are too small.

In order to achieve low thermal conductivity of the composite material on the one hand and sufficient mechanical stability on the other hand, the volume content of the airgel is preferably 20-97% (volume), particularly preferably 40-95% (volume), wherein the highest The volume content results in lower thermal conductivity and strength. In order to increase the porosity of the entire material, thereby improving the sound absorption performance, the material should also contain pores, for which the volume content of the airgel is preferably lower than 85% (volume).

In order to achieve high airgel volume fractions, preference is given to using particles with an advantageous bimodal particle size distribution. Depending on the application, for example in the field of sound insulation, other distributions may also be used.

The fibers or airgel particles are bonded to each other and to fibers and airgel particles by at least one binder. Binders can be used both for the bonding of fibers and airgel particles themselves and to each other, as well as for matrix materials.

Essentially all known binders are suitable for producing the composite material according to the invention. Inorganic binders, such as water glass binders, or organic binders or mixtures thereof may be used. The binder may also contain other inorganic and/or organic components.

Suitable organic binders are, for example, thermoplastics such as polyolefins or polyolefin waxes, styrene polymers, polyamides, ethylene vinyl acetate copolymers or blends thereof, or thermosetting plastics such as phenolic resins, resorcin Phenolic, urea or melamine resins. Adhesives such as melt adhesives, dispersion adhesives (in aqueous form, e.g. styrene-butadiene and styrene-acrylate copolymers), solvent adhesives or plastisols can also be used; other suitable Also reactive adhesives, e.g. in the form of one-component systems such as heat-curing epoxy resins, formaldehyde condensates, polyimides, polybenzimidazoles, cyanoacrylates, polyvinyl butyral, polyvinyl alcohol , oxygen-free adhesives, polyurethane adhesives and moisture-curing polysiloxanes, or in the form of two-component systems such as methacrylates, cold-curing epoxies, two-component polysiloxanes and cold-curing polyurethanes .

Preference is given to using polyvinyl butyral and/or polyvinyl alcohol.

The binder is preferably selected in such a way that, if it is present in liquid form at a certain stage of processing, it cannot or only insignificantly penetrate into the very loose airgel during this period. In addition to the selection of the binder, the penetration of the binder into the interior of the airgel particles can also be influenced by adjusting the process conditions such as pressure, temperature and mixing time.

If the binder forms an airgel and a fiber-embedded matrix, due to its low thermal conductivity, it is preferred to use a porous material such as a foam with a density of less than 0.75 g/ ^cm3 , preferably a polymeric foam (e.g. polystyrene or polyurethane foam) ).

In order to achieve a good distribution of the binder in the wedge cavity at high airgel contents and to achieve the best possible bond, the particle size of the binder in solid form is preferably smaller than that of the airgel particles. Likewise, it is necessary to operate at high pressure.

If the binder has to be processed at high temperatures, for example in the case of the use of melt or reactive binders such as melamine-formaldehyde resins, the binder must be selected such that its melting temperature does not exceed the melting temperature of the fibres.

The binder is usually used in an amount of 1-50% (volume), preferably 1-30% (volume) of the composite material. The binder is selected according to the mechanical and thermal requirements placed on the composite as well as the requirements regarding fire protection.

The composite material may contain effective amounts of other additives such as dyes, pigments, fillers, flame retardants, synergists for flame retardants, antistatic agents, stabilizers, plasticizers and infrared opacifiers.

In addition, the composite material may contain additives used or formed during preparation, such as lubricants such as zinc stearate during pressing, or reaction products of curing accelerators that are acidic or acid-cleaved when the resin is used.

The fire rating of composite materials is determined by the fire rating of the airgel, fibers and binders and, if necessary, other substances contained therein. In order to achieve the highest possible fire rating of composite materials, it is preferable to use non-combustible fiber types such as glass fibers or mineral fibers, or to use flame-retardant fiber types such as TREVIRA ^CS® or melamine resin fibers, inorganic-based aerogels ( Particular preference is given to binders based on SiO ₂ ) and flame retardants such as inorganic binders or urea resins and melamine formaldehyde resins, polysiloxane resin binders, polyimide and polybenzimidazole resins.

If a planar configuration such as a plate or mat is used, at least one side thereof can be coated with at least one covering layer in order to improve the surface properties, for example to increase robustness, to form a moisture- or dirt-resistant layer. Covering layers can also improve the mechanical stability of composite parts. If overlays are used on both sides, they can be the same or different.

All materials known to the person skilled in the art can be used as cover layer. They may not be porous and thus act as moisture barriers, eg plastic films, preferably metal foils or metallized plastic films reflecting thermal radiation. Porous coverings can also be used, which allow air to enter the material, thereby improving the sound insulation properties, such as porous films, papers, fabrics or fibers.

The cover layer itself can also consist of several layers. The cover layer can be secured with an adhesive, whereby the fibers and airgel particles are bonded to each other, or other adhesives can be used.

The surface of the composite material can also be sealed and cured by infiltrating at least one suitable material into the surface layer. Such materials are, for example, thermoplastic polymers, such as polyethylene and polypropylene, or resins, such as melamine formaldehyde resins.

The thermal conductivity of the composite material according to the invention is preferably 10 to 100 mW/mK, particularly preferably 10-50 mW/mK, especially 15-40 mW/mK.

Another object of the present invention is to provide a process for producing the composite material according to the invention.

If the binder is initially in powder form, which melts when using melt adhesives and reacts when using reactive adhesives at high temperature and possibly high pressure, a composite material can be obtained, for example, by using conventional The mixing device mixes the airgel particles, fibrous material and binder. The mixture is then shaped. Depending on the type of binder, the mixture is heated in the mold, if necessary, by heating under pressure, for example in the case of reactive binders, or by heating above the melting point of the binder in the case of melt binders solidify. A macroscopically porous material can be obtained in particular by processing the fibers, if they are not yet fluffed (for example small clumps of sheared fibers or small fiber webs), into clumps by methods well known to the skilled person. Already in this step it is possible to incorporate airgel particles into the fibers if desired. The fiber mass is then mixed together with binder and, if applicable, airgel particles, for example in a mixer, until the binder and, if applicable, airgel particles are distributed as uniformly as possible in the fibers. Thereafter the mass is placed in a mold and heated, if necessary, under pressure to a temperature above the melting point of the adhesive in the case of melt adhesives and above the temperature required for the reaction in the case of reactive adhesives temperature. After the binder has melted or reacted, the mass is allowed to cool. Preference is given here to using polyvinyl butyral. The density of the composite can be increased by using high pressure.

In a preferred embodiment, the mixture is compressed. Among them, the skilled person can choose a suitable extrusion machine and a suitable extrusion tool according to the application purpose. For pressing, lubricants known to the skilled person, such as zinc stearate in the case of melamine-formaldehyde resins, can be added if necessary. Due to the high air content of the aerogel-containing extrusion mass, it is preferred to use a vacuum extruder. In a preferred embodiment, the airgel-containing pressed mass is extruded into sheets. In order to avoid sticking of the compacted material to the die, it is possible to separate the mixture to be extruded containing the aerogel from the die using a separating aid such as parting paper. The mechanical strength of the aerogel-containing sheet can be improved by laminating a screen, fiber web or paper on its surface. These screens, webs or papers can either be retrofitted onto the aerogel-containing plates, wherein the screens, webs or papers can be impregnated, for example, with a suitable binder or adhesive, and then placed on a bonded to the surface of the board under pressure in a heatable extruder or, in a preferred embodiment, in one processing step by passing through a sieve impregnated, if necessary, previously with a suitable binder or binding agent The mesh, web or paper is placed in a press mold and placed on top of the aerogel-containing extrusion mass to be extruded, followed by pressing under pressure and temperature to form an aerogel-containing composite sheet.

The pressing is related to the binder used, and in any model, the pressing pressure is usually 1-1000 bar and the temperature is 0-300°C.

In the case of the use of phenol, resorcinol, urea and melamine formaldehyde resins, the pressing in any mold is preferably carried out at a pressure of 5-50 bar, particularly preferably 10-20 bar, at a temperature of preferably 100-200 °C, Particular preference is given to 130-190°C, especially 150-175°C.

If the binder is initially in liquid form, composite materials can be obtained, for example, by mixing airgel particles with fiber material using conventional mixing devices. The resulting mixture is then coated with a binder, for example by spraying, placed in a mold, and cured in the mold. Depending on the type of binder, curing of the mixture is accomplished, if necessary under pressure, by heating and/or evaporating the solvent or dispersant used. The airgel particles and fibers are preferably fluidized in a gas stream. Fill the model with the mixture, spraying the binder during filling. A macroscopically porous material can be obtained in particular by processing the fibers into pellets, if they are not yet fluffed (eg pellets of sheared fibers or webs of small pieces), in a manner well known to the person skilled in the art. Already in this step it is possible to incorporate airgel particles into the fibers if desired. Otherwise, the fiber mass is then mixed with binder and, if necessary, airgel particles, for example in a mixer, until the binder and, if applicable, airgel particles are distributed as uniformly as possible in the fibers. In this step or thereafter, the binder is sprayed into the mixture as finely distributed as possible, after which the mass is heated in a mold, if necessary under pressure, to the temperature required for bonding. It is then dried into a composite material using common methods.

If foam is used as a binder, composites can be obtained as follows depending on the type of foam.

If the foam is prepared by expanding expandable particulate bodies such as expandable polystyrene in a former, all components are intimately mixed and then typically heated, preferably by means of hot air or steam. As the particles expand, the pressure in the mold rises, causing the wedges to fill with foam, and the bond of the airgel particles is fixed. After cooling, the composite part is removed from the model and dried if necessary.

If the foam is prepared by extruding or expanding a non-viscous mixture followed by solidification, the fibers can be mixed into the liquid. The airgel particles are mixed with the forming liquid and then foamed.

If the material is to have a cover layer, it can be placed, for example, before or after filling the mold, so that coating and shaping are carried out in one process step, wherein the binder of the composite material is preferably used as the binder for the coating . However, it is also possible to apply the cover layer after the composite has been formed.

The form of the part formed from the composite material of the invention is not subject to any restrictions; the composite material can in particular be produced in the form of a plate.

Due to the high airgel content and low thermal conductivity, the composite material is particularly well suited for thermal insulation.

The composite material can be used, for example, directly in the form of a panel as a sound-absorbing material, or in the form of a resonant absorber for sound insulation. In addition to the damping effect of the airgel material, depending on the porosity of the macropores, an additional damping effect can occur due to the friction of air on the macropores in the composite. Macroscopic porosity can be influenced by varying fiber content and fiber diameter, airgel particle size and content, and binder type. The frequency- and size-dependent sound insulation properties can be varied in a manner known to the skilled person by selection of the covering layer, panel thickness and macroporosity.

Due to their macroscopic porosity and especially the large porosity and specific surface area of aerogels, the composite materials according to the invention are also suitable as adsorption materials for liquids, vapors and gases.

The invention is further illustrated below by means of examples without any limiting effect.

Example 1

Molded bodies made of airgel, polyvinyl butyral and fibers

90% by volume of hydrophobic airgel particles, 8% by volume of polyvinyl butyral powder ^® Mowital (polymer F), and 2% by volume of ^® Trevira Hochfest fibers were intimately mixed.

The average particle size of the hydrophobic airgel particles is 1-2 mm, the density is 120 kg/m ³ , the BET surface is 620 m ² /g, and the thermal conductivity is 11 mW/mK.

The bottom surface area of the pressed model is 30 cm x 30 cm, and is covered with a layer of separator paper. The pressed mass containing airgel is evenly distributed on top and the whole is covered with a layer of separator paper. It was pressed at 220° C. for 30 minutes to a thickness of 18 mm.

The obtained molded body had a density of 269 kg/m ³ and a thermal conductivity of 20 mW/mK.

Example 2

Shaped bodies made of airgel, polyvinyl butyral and recycled fibers

Make 80% (volume) the hydrophobic airgel particle of embodiment 1, 10% (volume) polyvinyl butyral powder ^® Mowital (polymer F) and the polyester fiber of 10% (volume) coarse decomposition as recovery The fibers are intimately mixed.

The bottom surface area of the pressed model is 30 cm x 30 cm, and is covered with a layer of separator paper. The pressed mass containing airgel is evenly distributed on top and the whole is covered with a layer of separator paper. It was pressed at 220° C. for 30 minutes to a thickness of 18 mm.

The obtained compact had a density of 282 kg/m ³ and a thermal conductivity of 25 mW/mK.

Example 3

Shaped bodies made of airgel, polyvinyl butyral and recycled fibers

Make 50% (volume) the hydrophobic airgel particle of embodiment 1, 10% (volume) polyvinyl butyral powder ^® Mowital (polymer F) and the polyester fiber of 40% (volume) coarse decomposition as recovery The fibers are intimately mixed.

The bottom surface area of the pressed model is 30 cm x 30 cm, and is covered with a layer of separator paper. The pressed mass containing airgel is evenly distributed on top and the whole is covered with a layer of separator paper. It was pressed at 220° C. for 30 minutes to a thickness of 18 mm.

The obtained compact had a density of 420 kg/m ³ and a thermal conductivity of 55 mW/mK.

Example 4

Shaped bodies made of airgel, polyethylene wax and fibers

60% by weight of the hydrophobic airgel particles of Example 1, 38% by weight of polyethylene wax powder ^® Ceridust 130 and 2% by volume of ^® Trevira Hochfest fibers were intimately mixed.

The bottom surface area of the pressed model was 12 cm x 12 cm, and was covered with a layer of separator paper. The pressed mass containing the airgel is evenly distributed on top and the whole is covered with a layer of split paper. Press at 170° C. for 30 minutes with a pressure of 70 bar.

The thermal conductivity of the obtained molded body was 25 mW/mK.

Example 5

Shaped bodies made of airgel, polyethylene wax and fibers

50% by weight of the hydrophobic airgel particles of Example 1, 48% by weight of polyethylene wax powder Hoechst-Wachs PE 520 and 2% by volume of ^® Trevira Hochfest fibers were intimately mixed.

The bottom surface area of the pressed model was 12 cm x 12 cm, and was covered with a layer of spacer paper. The pressed mass containing airgel is evenly distributed on top and the whole is covered with a layer of separator paper. Press at 180° C. for 30 minutes with a pressure of 70 bar.

The thermal conductivity of the obtained molded body was 28 mW/mK.

Example 6

Shaped bodies made of airgel, polyvinyl alcohol and fibers

90% by weight of the hydrophobic airgel particles of Example 1, 8% by weight of polyvinyl alcohol solution and 2% by volume of ^® Trevira Hochfest fibers were intimately mixed. The polyvinyl alcohol solution consisted of 10% by weight of ^® Mowiol Typ 40-88, 45% by weight of water and 45% by weight of ethanol.

The bottom surface area of the pressed model was 12 cm x 12 cm, and was covered with a layer of separator paper. The pressed mass containing the airgel was evenly distributed on top and the whole was pressed with a pressure of 70 bar for 2 minutes and then dried.

The thermal conductivity of the obtained molded body was 24 mW/mK.

The thermal conductivity of airgel particles is determined by the filament method (see for example O. Nielsson, G. Rueschenpoehler, J. Gross, J. Fricke, High Temperature-High Pressures, Vol. 21, 274-274 (1989)).

The thermal conductivity of the molded body was determined according to DIN52612.

Claims (18)

1. matrix material contains 20-97% (volume) aerogel particle, at least a binding agent of 1-50% (volume) and at least a filamentary material of 0.1-40% (volume), the wherein particle diameter 〉=0.5mm of aerogel particle.

2. according to the described matrix material of claim 1, it is characterized in that filamentary material contains glass fibre as main ingredient.

3. according to the described matrix material of claim 1, it is characterized in that filamentary material contains organic fibre as main ingredient.

4. according to each described matrix material among the claim 1-3, it is characterized in that the porosity of aerogel particle is greater than 60%, density is lower than 0.4g/cm ³, thermal conductivity is lower than 40mW/mK.

5. according to each described matrix material among the claim 1-4, it is characterized in that aerogel is in case of necessity by the SiO of organism modification ₂-aerogel.

6. according to each described matrix material among the claim 1-5, it is characterized in that at least a portion aerogel particle has hydrophobic surface groups.

7. according to each described matrix material among the claim 1-6, it is characterized in that the density of binding agent is less than 0.75g/cm ³

8. according to each described matrix material among the claim 1-7, it is characterized in that binding agent contains mineral binder bond as main ingredient.

9. according to the described matrix material of claim 8, it is characterized in that mineral binder bond is a water glass.

10. according to each described matrix material among the claim 1-7, it is characterized in that binding agent contains organic binder bond as main ingredient.

11. the matrix material according to described in the claim 10 is characterized in that, organic binder bond is polyvinyl butyral acetal and/or polyvinyl alcohol.

12., it is characterized in that at least a portion aerogel particle and/or binding agent contain infrared light screening agent at least according to each described matrix material among the claim 1-11.

13. according to each described matrix material among the claim 1-12, it is characterized in that it has a kind of plane form, and be coated with one deck tectum at least at least one side.

14. the preparation method of each described matrix material is characterized in that among the claim 1-13, and aerogel particle is mixed with binding agent mutually with filamentary material, makes mixture forming and curing.

15. the application of each described matrix material aspect thermal insulation and/or sound insulation among the claim 1-13.

16. formed body contains each described matrix material among the claim 1-13.

17. formed body is made up of each described matrix material among the claim 1-13 basically.

18., it is characterized in that it has the form of plate according to claim 16 or 17 described formed bodys.