CORE MATERIAL FOR VACUUM INSULATION PANEL INCLUDING POROUS ALUMINOSILICATE, AND VACUUM INSULATION PANEL PROVIDED WITH THE SAME

Abstract

Provided are a core material for a vacuum insulation panel including porous aluminosilicate, and a vacuum insulation panel provided with the same. The core material for the vacuum insulation panel according to the present disclosure has superior long-term durability and improved gas adsorption ability (particularly, superior water absorption ability) while requiring a low raw material cost. The vacuum insulation panel including the core material may exhibit more improved insulation performance by minimizing a reduction in the vacuum degree without an additional getter or absorbent.

Claims

1. A core material for a vacuum insulation panel, comprising porous aluminosilicate having an argon adsorption Brunauer-Emmett-Teller (BET) surface area of 300 m.sup.2/g or more and an external specific surface area (ESA) of 150 m.sup.2/g or more.

2. The core material for the vacuum insulation panel of claim 1, wherein the porous aluminosilicate has a Barrett-Joyner-Halenda (BJH) desorption average pore width of 5 nm to 15 nm.

3. The core material for the vacuum insulation panel of claim 1, wherein the porous aluminosilicate has pores satisfying the following Equation 1:
V.sub.meso/V.sub.micro>3.0   [Equation 1] wherein V.sub.meso represents a Barrett-Joyner-Halenda (BJH) cumulative volume of a mesopore having a pore size of 2 nm to 300 nm, and V.sub.micro represents a volume of a micropore having a pore size of less than 2 nm, as calculated from argon adsorption Brunauer-Emmett-Teller (BET) surface area by the t-plot method.

4. The core material for the vacuum insulation panel of claim 1, wherein the porous aluminosilicate has a water absorption rate of 18% by weight or more, 22% by weight, or more, and 25% by weight or more, when humidified at relative humidity of 80%, 90%, and 95% under an isothermal condition of 25° C., respectively.

5. A vacuum insulation panel, comprising: the core material of claim 1; and an outer shell material sealing and covering the core material.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0056] FIG. 1 is a schematic cross-sectional view of a vacuum insulation panel according to an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0057] Hereinafter, preferred examples are provided for better understanding. However, these examples are for illustrative purposes only, and the invention is not intended to be limited by these examples.

EXAMPLE 1

[0058] 3.02 g of NaOH was introduced into a reactor, and then 5.43 g of triple distilled water was added thereto and mixed well. To this solution, 7.76 g of sodium silicate (˜10.6% Na.sub.2O, ˜26.5% SiO.sub.2) was added and completely dissolved under stirring at 800 rpm at room temperature. To this prepared solution, 3.8 g of metakaolin was added and stirred at 800 rpm at room temperature for 40 minutes to obtain a geopolymer resin having a Na:Al:Si atomic ratio of about 3:1:2.

[0059] The geopolymer resin was heated in an oven under conditions of atmospheric pressure and 70° C. for one day to obtain a geopolymer resin of about pH 14. The heat-treated geopolymer resin was washed by adding a sufficient amount of triple distilled water thereto, and centrifuged at 10,000 rpm for 5 minutes, followed by decantation of a clear supernatant of about pH 14. These washing, centrifugation, and decantation processes were repeated until pH of the supernatant reached about 7.

[0060] The neutralized geopolymer resin was dried in a vacuum oven at 80° C. overnight to obtain a final product of porous aluminosilicate. Physical properties of the final product were measured and are shown in the following Tables 1 and 2.

EXAMPLE 2

[0061] 3.02 g of NaOH was introduced into a reactor, and then 5.43 g of triple distilled water was added thereto and mixed well. To this solution, 7.76 g of sodium silicate (˜10.6% Na.sub.2O, ˜26.5% SiO.sub.2) was added and completely dissolved under stirring at 800 rpm at room temperature. To this prepared solution, 3.8 g of metakaolin was added and stirred at 800 rpm at room temperature for 40 minutes to obtain a geopolymer resin having a Na:Al:Si atomic ratio of about 3:1:2.

[0062] The geopolymer resin was heated in an oven under conditions of atmospheric pressure and 70° C. for one day to obtain a geopolymer resin of about pH 14. The heat-treated geopolymer resin was washed by adding a sufficient amount of a 7% nitric acid aqueous solution thereto, and centrifuged at 10,000 rpm for 5 minutes, followed by decantation of a clear supernatant of about pH 14. These washing, centrifugation, and decantation processes were repeated until pH of the supernatant reached about 7.

[0063] The neutralized geopolymer resin was dried in a vacuum oven at 80° C. overnight to obtain a final product of porous aluminosilicate.

COMPARATIVE EXAMPLE 1

[0064] Porous aluminosilicate was obtained in the same manner as in Example 1, except that 4.88 g of triple distilled water was further added (that is, a total of 10.31 g of triple distilled water was added) in the process of obtaining the geopolymer resin.

COMPARATIVE EXAMPLE 2

[0065] Zeolite 13X, which is a product of Sigma-Aldrich, was obtained.

TABLE-US-00001 TABLE 1 Comparative Comparative Example 1 Example 2 Example 1 Example 2 BET (m.sup.2/g) 519 371 558 787 ESA (m.sup.2/g) 210 206 117 12 A.sub.micro (m.sup.2/g) 309 165 441 775 Pore width (nm) 8.18 9.29 4.28 2.89 V.sub.total (cm.sup.3/g) 0.72 0.61 0.32 0.30 V.sub.meso (cm.sup.3/g) 0.59 0.50 0.16 0.02 V.sub.micro (cm.sup.3/g) 0.13 0.11 0.16 0.28 V.sub.meso/micro 4.54 4.55 1.00 0.71 BET (m.sup.2/g): Brunauer-Emmett-Teller (BET) surface area ESA (m.sup.2/g): External specific surface area A.sub.micro (m.sup.2/g): Surface area of a micropore having a pore size of less than 2 nm Pore width (nm): Barrett-Joyner-Halenda (BJH) desorption average pore width V.sub.total (cm.sup.3/g): Total pore volume V.sub.meso (cm.sup.3/g): Barrett-Joyner-Halenda (BJH) cumulative volume of a mesopore having a pore size of 2 nm to 300 nm V.sub.micro (cm.sup.3/g): Volume of a micropore having a pore size of less than 2 nm, as calculated from argon adsorption Brunauer-Emmett-Teller (BET) surface area by the t-plot method.

TABLE-US-00002 TABLE 2 Water absorption Example Example Comparative Comparative rate (wt %) 1 2 Example 1 Example 2 @ 25° C., 70% RH 17.42 14.67 12.19 19.43 @ 25° C., 80% RH 21.07 18.80 13.65 19.76 @ 25° C., 90% RH 25.59 24.56 14.94 20.13 @ 25° C., 95% RH 30.41 30.69 16.39 20.54

[0066] Referring to Tables 1 and 2, the porous aluminosilicates according to Examples 1 and 2 had a large external specific surface area (ESA) and a BJH desorption average pore width, while the mesopore volume was about 4.5 times greater than the micropore volume. Therefore, it was confirmed that the porous aluminosilicates according to Examples 1 and 2 exhibited a high water absorption rate of up to 30% by weight under relative humidity of 80% or higher, thereby being suitably used as a core material for a vacuum insulation panel.

[0067] In contrast, the porous aluminosilicates according to Comparative Examples 1 and 2 had a relatively small external specific surface area, BJH desorption average pore width, mesopore volume, etc., and therefore they had a remarkably low water absorption rate.

REFERENCE NUMERALS

[0068] 100: Vacuum insulation panel

[0069] 110: Outer shell material

[0070] 120: Core material