Aluminum composite panel with aerogel and method for its production

Description

[Technical Field]

[0001] The present invention relates to an aluminum composite panel, and particularly, to an aluminum composite panel containing an aerogel, which includes an aerogel composite using a silica aerogel and a thermoplastic resin and thus having an improved adiabatic property, and improved flame retardant properties and moldability, and a method for manufacturing the same.[Background Art]

[0002] An aluminum composite panel is a special panel in a sandwich structure in which a synthetic resin such as a polymer non-toxic polyethylene resin or an inorganic material is applied between two aluminum plates having excellent corrosion resistance. The aluminum composite panel is a new material which is lightweight, thereby avoiding damages to the inside and outside of a wall, is very firm and smooth, and has an excellent design factor as well as excellent functionalities, such as an adiabatic property for protecting a building and a sound insulation property. Accordingly, the aluminum composite panel is widely used for the internal and external finishing, partitions, ceilings or entrances of a building.

[0003] Patent Document 1 of the prior art below describes a representative aluminum composite panel in the conventional art, which is manufactured by mixing and heating flame retardant powder and polyethylene pellets to prepare a mixed paste, and then performing extrusion molding. However, when the aluminum composite panel is manufactured in such a manner, it is difficult, if not impossible, to ensure flowability of the mixed paste during the extrusion molding. Moreover, in the case of fire, a flame retardant synthetic resin filled between aluminum plates flows downward due to heat, and during extrusion using an extruder, to ensure the flowability of the flame retardant synthetic resin, the flame retardant powder may not be mixed at more than maximum 60 to 65 wt%. Consequently, the flame retardant properties of the aluminum composite panel may not be enhanced any further.

[0004] In addition, a method for manufacturing an aluminum composite panel by applying a flame retarding material, for example, magnesium hydroxide, sodium hydroxide or aluminum hydroxide to a base, which is disclosed in Patent Document 2, has been also known. However, this method leads to high equipment and manufacturing costs during the fabrication process. Moreover, when a panel is molded in a curved or circular shape, the panel lacks flexibility thus presents further difficulties during the fabrication process.

[0005] Meanwhile, glass wool or rock wool used as a base in the conventional aluminum composite panel exhibits a decrease in an adiabatic property and an increase in a weight over time due to high hygroscopicity.

[0006] As described above, the conventional aluminum composite panel does not have adequate adiabatic properties, flame retardant properties, and moldability.

[0007] WO 2005 / 047381 A1 discloses a material comprising aerogel particles and a polytetrafluoroethylene (PTFE) binder formed having a thermal conductivity of less than or equal to 25 mW / m K at atmospheric conditions. The material is moldable or formable, having little or no shedding or filler particles, and may be formed into structures such as tapes or composites, for example, by bonding the material between two outer layers. Advantageously, composites may be flexed, stretched, or bent without significant dusting or loss of insulating properties.[Disclosure][Technical Problem]

[0008] The present invention is developed to improve such problems, and is directed to providing an aluminum composite panel containing an aerogel, having improved adiabatic properties and flame retardant properties compared to the conventional aluminum composite panel. In addition, the aluminum panel of the present invention is capable of being molded in various forms using a mold. A method for manufacturing the same is also provided.[Technical Solution]

[0009] The present the present invention provides a method for manufacturing an aluminum composite panel according to claim 1.

[0010] According to the manufacturing method, in step (a), the silica aerogel powder and the thermoplastic resin powder may be mixed at a speed of 10 to 30 rpm using a ribbon mixer.

[0011] According to the manufacturing method, the silica aerogel powder may have a uniform size of 100 µm or less, and also have a density of 0.05 to 0.1 g / cm 3< .

[0012] According to the manufacturing method, the thermoplastic resin powder may have a uniform size of 100 µm or less, and also have a density of 0.1 g / cm 3< or less.

[0013] According to the manufacturing method, in step (b), the aerogel composite is formed by compressing the mixture under a pressure of 1724 to 3448 kPa (250 to 500 psi).

[0014] According to the manufacturing method, in step (b), the aerogel composite is formed by heating the mixture for 2 hours at 120 to 200 °C.

[0015] According to the manufacturing method, in step (c), the adhesive resin may be applied to each of the upper and lower surfaces of the aerogel composite at a thickness of 0.1 mm.[Advantageous Effects]

[0016] An aluminum composite panel containing an aerogel prepared according to the present invention as described above has lower hygroscopicity than the conventional aluminum composite panel due to a silica aerogel, and thus exhibits improved adiabatic properties and improved flame-retardant properties. Also, the aluminum composite panel of the present invention contains a suitable amount of thermoplastic resin, and therefore has excellent moldability, is light, and facilitates construction work.[Description of Drawings]

[0017] FIG. 1 is an exploded perspective view of a structure of an aluminum composite panel containing an aerogel according to the present invention. FIG. 2 is a process flowchart illustrating a method for manufacturing an aluminum composite panel containing an aerogel according to the present invention. FIG. 3 is an image obtained by a hygroscopicity test of the aerogel composite constituting the present invention. FIG. 4 is an image obtained by a fire resistance test of the aerogel composite constituting the present invention. [Explanation of symbols]

[0018] 10: Aerogel composite; 20: Adhesive resin; and 30: Aluminum plate. [Modes of the Invention]

[0019] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the following embodiments are provided so that those of ordinary skill in the art can fully understand the present invention and thus may be modified into various forms, and the scope of the present invention is not limited to the examples that will be described below.

[0020] FIG. 1 is an exploded perspective view of a structure of an aluminum composite panel containing an aerogel according to the present invention.

[0021] As shown in FIG. 1, the aluminum composite panel containing an aerogel according to the present invention is composed of an aerogel composite 10, an adhesive resin 20 applied to each of the upper and lower surfaces of the aerogel composite 10, and aluminum plates 30 attached to the adhesive resin 20 .

[0022] Outside the scope of the invention, the aerogel composite 10 is composed of a mixture of 1 to 90 wt% of a silica aerogel and 10 to 99 wt% of a thermoplastic resin. The silica aerogel is flame retardant and results in an adiabatic effect due to its structure in which nano-scale pores are formed. When the silica aerogel is contained at less than 1 wt%, the adiabatic effect and the flame-retardant properties of the panel may not be expected. In addition, when the silica aerogel is contained at more than 90 wt%, proportionally, a content of the thermoplastic resin is reduced, and thus extrusion moldability is degraded. Therefore, the contents of silica aerogel and the thermoplastic resin are preferably mixed in the above ranges.

[0023] The thermoplastic resin used in the present invention may be any one or a mixture of at least two of ethylene vinyl acetate (EVA), polyethylene (PE), polypropylene (PP), and polyvinyl butyral (PVB). These thermoplastic resins impart extrusion moldability when the aerogel composite 10 is molded in the mixture with the silica aerogel. However, when the content of the thermoplastic resin is less than 10 wt%, the extrusion moldability is insufficient. Moreover, when the content of the thermoplastic resin is more than 99 wt%, due to lack of the silica aerogel, it is difficult to obtain the adiabatic effect and the flame - retardant properties of the panel. Therefore, the thermoplastic resin should be mixed in the range of 10 to 99 wt%.

[0024] In the preparation of the aerogel composite 10, the silica aerogel and the thermoplastic resin are preferably mixed in the form of powder for a uniform mixture. Here, for a uniform mixture, the silica aerogel powder most preferably has a uniform size of 100 µm or less and a density of 0.05 to 0.1 g / cm 3< , and the thermoplastic resin powder also most preferably has a uniform size of 100 µm or less and a density of 0.1 g / cm 3< or less.

[0025] A method for manufacturing an aluminum composite panel containing an aerogel according to the present invention, constituted as described above, comprises the following steps.

[0026] That is, FIG. 2 is a process flowchart illustrating a method for manufacturing an aluminum composite panel containing an aerogel according to the present invention, and the process sequence is as follows.

[0027] In the first step of the present invention, step (a), a silica aerogel and a thermoplastic resin are prepared in the form of powder, and 1 to 90 wt% of the silica aerogel powder and 10 to 99 wt% of the thermoplastic resin powder are mixed to form a mixture (S1). Here, the thermoplastic resin may be any one or a mixture of at least two of ethylene vinyl acetate (EVA), polyethylene (PE), polypropylene (PP) and polyvinyl butyral (PVB). In addition, for a uniform mixture, the silica aerogel powder most preferably has a uniform size of 100 µm or less and a density of 0.05 to 0.1 g / cm 3< , and the thermoplastic resin powder also most preferably has a uniform size of 100 µm or less and a density of 0.1g / cm 3< or less. The silica aerogel powder is preferably mixed with the thermoplastic resin powder at a speed of 10 to 30 rpm using a ribbon mixer. The ribbon mixer, which is also referred to as a screw mixer, may serve to uniformly mix powders with a plurality of ribbon-like (or screw-like) wings. and is decreased in mixing performance at a speed of less than 10 rpm, and causes the silica aerogel to be scattered at a speed of more than 30 rpm, and therefore needs to be operated at a speed in the range of 10 to 30 rpm.

[0028] Subsequently, in the second step, step (b), an aerogel composite is prepared by putting the mixture of the silica aerogel and the thermoplastic resin in a mold (S2-1) for manufacture in a panel form and then heating (S2-3), cooling (S2-4) and demolding (S2-5) the resulting mixture. Particularly, heating is performed for 2 hours at 120 to 200 °C, and due to the heating under the temperature and time conditions, the mixture of the silica aerogel and the thermoplastic resin has flowability in a semi-melted or melted state, and thus is easily molded in a mold. Meanwhile, in the preparation of the aerogel composite, the mixture of the silica aerogel and the thermoplastic resin is compressed under a pressure of 1724 to 3448 kPa (250 to 500 psi) before heating and after being put in the mold (S2-2). During the compression, the mixture of the silica aerogel and the thermoplastic resin is easily molded in the mold. However, under a pressure of less than 1724 kPa or more than 3448 kPa (less than 250 psi or more than 500 psi) molding is disrupted. Therefore the compression is preferably performed under a pressure of 1724 to 3448 kPa (250 to 500 psi).

[0029] Afterward, in the third step, step (c), an adhesive resin is applied to each of the upper and lower surfaces of the aerogel composite prepared in step (b) (S3-1), and then the aluminum plates are attached to the applied adhesive resin (S3-2). Particularly, when the adhesive resin is applied to each of the upper and lower surfaces of the aerogel composite, it is preferably applied at a thickness of 0.1 mm.

[0030] As the aluminum plates are applied to the adhesive resin as described above, a desired aluminum composite panel containing an aerogel of the present invention is completed.

[0031] Meanwhile, FIG. 3 is an image obtained by a hygroscopicity test of the aerogel composite constituting the present invention, and FIG. 4 is an image obtained by a fire resistance test of the aerogel composite constituting the present invention.

[0032] First, as shown in FIG. 3, it can be seen that a contact angle is proportional to an increased content of the silica aerogel from less than 10 wt%, to 10 wt%, to 20 wt%, and to 30 wt%. Therefore, as the aerogel composite of the present invention contains up to 90% of the silica aerogel, it can be seen that it has low hygroscopicity, thereby resulting in improved adiabatic properties.

[0033] Moreover, as shown in FIG. 4, as the content of the silica aerogel is increased from less than 10 wt%, to 10 wt%, to 20 wt%, and to 30 wt%, it can be seen that the original shape is maintained to the greatest extent possible and the sample is not melted due to high temperatures.

[0034] Therefore, the aluminum composite panel containing an aerogel, manufactured according to the present invention, has improved adiabatic properties and flame-retardant properties compared to the conventional aluminum composite panel. Also, since the aluminum composite panel containing an aerogel contains a suitable amount of the thermoplastic resin together with the silica aerogel, it can be molded in various forms using a mold.

Claims

1. A method for manufacturing an aluminum composite panel containing an aerogel, comprising: (a) preparing a mixture consisting of 10 to 90 wt% of silica aerogel powder, and 10 to 90 wt% of thermoplastic resin powder, wherein the silica aerogel powder and thermoplastic resin powder are mixed in the form of a powder (S1); (b) preparing an aerogel composite by putting the uniform mixture prepared in step (a) in a mold (S2-1) for manufacture in a panel form and then heating (S2-3), cooling (S2-4) and demolding (S2-5) the resulting mixture, wherein, in step (b), the aerogel composite is compressed under a pressure of 1724 to 3448 kPa (250 to 500 psi) and heated for 2 hours at 120 to 200 °C; and (c) attaching an aluminum plate in a state in which an adhesive resin has been applied to each of the upper and lower surfaces of the aerogel composite prepared in step (b) so that the aerogel composite consisting 10 to 90 wt % of silica aerogel powder extends from the upper surface of the aerogel composite on which the adhesive resin has been applied to the lower surface of the aerogel composition on which the adhesive resin has been applied.

2. The method of claim 1, wherein, in step (a), the silica aerogel powder and the thermoplastic resin powder are mixed at a speed of 10 to 30 rpm using a ribbon mixer.

3. The method of claim 1, wherein, in step (c), the adhesive resin is applied at a thickness of 0.1 mm to each of the upper and lower surfaces of the aerogel composite.

4. The method of claim 1, wherein the mixture contains up to 30 wt% of silica aerogel.

5. The aluminum composite panel made by the method of any of claims 1-4.