KR20090120922A - Panel with formaldehyde adsorption, water adsorption and desorption functions and preparation thereof - Google Patents

Abstract

PURPOSE: A hydrothermal synthesis panel and a manufacturing method thereof are provided to remove humidity and absorb formaldehyde. CONSTITUTION: A hydrothermal synthesis panel comprises calcium hydroxide, white cement, quartz and porosity raw material. A raw material mixture is made from the calcium hydroxide, the white cement and the quartz at 0.5~1.1 ratio. A porosity raw material is made from diatomite, bentonite and zeolite. The porosity raw material is mixed into the raw material mixture of 10~30 weight%.

Description

Panel for building hydrothermal composite interiors that can formaldehyde adsorption and moisture absorption and moisture absorption and its manufacturing method {Panel with formaldehyde adsorption, water adsorption and desorption functions and preparation

The present invention relates to an inorganic panel suitable for use as a building interior material, in particular a multifunctional inorganic panel having a humidity control function and the adsorption and decomposition function of volatile organic compounds, and a method of manufacturing the same.

Most modern people spend more than 80 ~ 90% of their time indoors, and the importance of indoor environment (volatile organic compounds (T-VOC) and indoor temperature and humidity) is increasing. Particularly in the case of organic interior materials, the fire fragility and the generation of volatile organic compounds may be more severe and may have a harmful effect on the human body.

Accordingly, an object of the present invention is to provide a multifunctional inorganic panel having a humidity control function and a adsorption and decomposition function of a volatile organic compound.

According to the present invention for solving the above problems is a hydrothermal composite building interior panel capable of adsorption of moisture and moisture absorption, characterized in that the hydrothermal synthesis of the raw material mixture containing slaked lime, white cement and silica and porous raw materials do.

The panel of the present invention has a very useful effect of providing a comfortable living environment when used as a building interior material to formaldehyde adsorption and moisture absorption and moisture absorption.

Raw materials used for manufacturing the functional panel of the present invention are hydrated lime, white cement, silica, and the like, and the chemical analysis of these raw materials is shown in Table 1. As shown in Table 1, the slaked lime [Ca (OH) ₂ ] has a main component of CaO of 69.50% and a loss on ignition (LOI) of 26.90%. LOI originates from H ₂ O in calcium hydroxide because Ca (OH) ₂ decomposes into CaO and H ₂ O at about 400-500 ° C. The silica is 93.80% SiO ₂ and 3.08% Al ₂ O ₃ . The white cement has a CaO content of 68.42%, a SiO ₂ content of 22.80%, and an Al ₂ O ₃ content of 6.16%.

In the functional panel of the present invention, diatomaceous earth, bentonite, zeolite and the like are used as porous raw materials. Diatomaceous earth was obtained from the 4th diatomaceous earth and the diatomaceous earth from China, bentonite from Hwasun and Pohang areas, and zeolite from Gyeongju and Pohang areas. The results are shown in Table 2. The content of SiO ₂ , the main component of diatomaceous earth, was 66.60 ~ 91.15%, and the ignition loss was widely distributed (0.22 ~ 9.53%). The SiO ₂ content of bentonite was 75.0% (H) and 60.6% (P), and the Al ₂ O ₃ content was 14.8% (H) and 16.3% (P).

Raw material Chemical Composition (Unit: wt%) SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ CaO K ₂ O Na ₂ O LOI Slaked lime 2.12 0.77 0.34 69.50 0.11 0.21 26.90 burr 93.80 3.08 1.33 0.06 0.76 0.08 - Back cement 22.80 6.16 0.26 68.42 0.21 - 0.10

Raw material SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ CaO K ₂ O Na ₂ O LOI Diatomaceous earth Cheorwon (G) 66.60 15.40 3.64 0.36 2.15 0.78 9.53 Cheorwon (P) 86.70 6.11 2.07 0.09 1.12 0.17 3.17 China (W) 88.01 4.20 1.37 0.23 1.85 1.25 0.22 China (P) 91.15 2.96 1.48 0.25 0.70 0.40 0.24 Bentonite Hwasun (H) 75.00 14.80 1.51 0.03 4.94 0.23 3.14 Pohang (P) 60.60 16.30 5.24 2.62 1.99 1.71 8.00 Zeolite Gyeongju (K) 70.30 13.60 1.29 2.51 3.17 1.93 5.76 Pohang (P) 63.20 15.70 3.72 2.54 2.15 2.18 7.64

In the present invention, the CaO / SiO ₂ ratio was changed to 0.5, 0.7, 0.9, and 1.1 using only silica, slaked lime and white cement primarily, and the mixing ratio of each raw material was designed as shown in Table 3 (ref.) . The blended raw material was mixed with 10% (mixed water / mixed raw material) of mixed water, and then press-molded. Pressurization was performed for 1 minute by the force of 100kgf / ㎠ and demolded by hydrothermal synthesis. Hydrothermal synthesis was maintained at 180 to 7 hours, and then panel characteristics were analyzed.

  C / S ratio Raw material blending ratio (wt%) Slaked lime burr Back cement 0.5 30 55 15 0.7 (Ref.) 30 46 24 0.9 30 40 30 1.1 30 34.5 35.5

    In order to measure and calculate the moisture absorption and moisture absorption of 20 × 20 cm panels manufactured by hydrothermal synthesis, JIS A 1470-2002 (Test of moisture absorption and moisture absorption of moisture-absorbing materials-Part 1 humidity response method-Test method of moisture absorption and moisture absorption by humidity change) is applied. Experiment. All of the manufactured panels were sealed using aluminum tape except for the moisture absorption and desorption test surface, and thoroughly sealed to prevent moisture absorption and desorption outside the test surface. In addition, after the measured value was obtained, it was multiplied by 25 (0.2m × 0.2m × 25 = 1m 2) in order to convert the moisture absorption and moisture absorption into 1 m 2.

Figure 1 shows the moisture absorption and moisture absorption of the panel with the C / S ratio is changed. The moisture absorption amount was about 80 g / m 2, and the moisture absorption amount was about 40 g / m 2. In addition, when the C / S ratio is 0.7, the highest moisture absorption characteristics, but the difference in the amount of moisture absorption is about 10g / ㎡ level, the difference did not occur significantly. In particular, when the C / S ratio was 0.5, the lowest moisture absorption was observed, and at 0.7 or more, almost similar characteristics were expressed. The moisture absorption amount derived from the change in the C / S ratio was similar to that of 80 g / m 2, but the moisture absorption amount was less than the level of 60 g / m 2. In other words, according to the hydrothermal synthesis method (ALC manufacturing method) using only CaO source (calcite) lime, cement and SiO ₂ source silica, it was confirmed that the moisture-proof property is difficult to express only by changing the C / S ratio.

Therefore, a porous raw material that is easy to absorb moisture and moisture is introduced under the conditions of Table 2.

Kinds Diatomite Bentonite Zeolite Mixing ratio (%) Ref. + Each blend material (10%, 20%, 30%)

    The moisture absorption and desorption characteristics of the panel using porous raw materials (diatomaceous earth, bentonite, zeolite, etc.) are shown in FIG. 2. As shown in Figure 2 it can be seen that the moisture absorption and moisture absorption is greatly improved according to the use of the porous raw material, in particular, the moisture absorption and moisture-proof properties such as pohang zeolite and iron source diatomaceous earth. The moisture absorption of the Pohang zeolite 10% panel was about 180g / m 2, and the moisture absorption of the iron source diatomaceous earth (P) 10% panel was about 170g / m 2. In addition, the moisture-proof amount of Pohang zeolite was about 105 g / m 2, far exceeding the target value of 60 g / m 2. In most panels, when 10% of the porous raw material was added, excellent hygroscopic and moisture proof properties were exhibited.

Tables 5 and 6 show the specific surface area and pore volume of the panel by type and content of porous raw materials. In the Pohang zeolite 10% panel, the specific surface area was 30 m 2 / g, the pore volume was 0.14 cm 3 / g, and the specific surface area and the pore volume decreased with increasing content of the zeolite. The iron source diatomaceous earth (P) had a specific surface area of 29 m 2 / g and a pore volume of 0.11 cm 3 / g at 10% addition, but decreased at 30%. Pohang bentonite was not significantly different depending on the amount of addition, but the specific surface area decreased slightly. In other words, the specific surface area and pore volume were decreased as the amount of porous raw material was increased, and this specific surface area and pore volume was finally determined to lower the moisture absorption and moisture barrier ability.

Classification Cheorwon (P) Diatomite Pohang Bentonite 10% 20% 30% 10% 20% 30% Specific surface area (㎡ / g) 29 29 17 28 28 26 Pore volume. (Cm 3 / g) 0.11 0.12 0.06 0.13 0.12 0.11 20 ~ 100Åculmulative pore vol. (Cm 3 / g) 0.03 0.05 0.01 0.02 0.02 0.02

Pohang Zeolite 10% 20% 30% Specific surface area ㎡ / g) 30 24 24 Pore volume (cm 3 / g) 0.14 0.10 0.09 20 ~ 100Åculmulative pore vol. (Cm 3 / g) 0.03 0.02 0.02

    40 ppm of formaldehyde gas was used to evaluate the formaldehyde adsorption characteristics of the panel. The formaldehyde adsorption characteristics of the panel according to the C / S ratio showed more than 90% of the adsorption performance when the C / S ratio was 0.7. However, the other C / S ratio was below 90%.

    Adsorption capacity of formaldehyde was improved with the use of porous raw materials, and in particular, the rate of formaldehyde adsorption was also increased. In addition, it exhibited excellent adsorption characteristics in Pohang zeolite, iron source diatomaceous earth, and Pohang bentonite. This characteristic is similar to the adsorption characteristic of water, which is assumed to be related to the pore characteristics of the panel. That is, it was determined that the adsorption of formaldehyde increased as the content of nanopores increased.

The microstructure of the panel to which 10% of the porous raw material is added is shown in the photograph of FIG. 5. As shown in FIG. 5, the microstructure of the panel according to the addition of the porous raw material was found to coexist and grow in plate-shaped tobemorite crystals, lath or fiber-shaped crystals, and C-S-H gel. In particular, plate-like crystals and lath (or fiber) crystals were easily observed in iron source diatomaceous earth and Pohang bentonite, and in Chinese diatomaceous earth, plate-shaped tobemorite crystals were mainly observed. Pohang zeolite was observed not only lamellar tobemorite but also lath (or fiber) crystals.

The flexural strength characteristics according to the C / S ratio and the type and content of the porous raw material are shown in FIG. 6. As shown in FIG. 5A, the flexural strength value slightly increased as the C / S ratio was increased, and the porosimeter porosity measurement results for measuring the pore size of the micrometer are shown in FIG. 7. This is because the micropores inside the panel tended to decrease gradually as the C / S ratio increased from 0.5 to 1.1. In other words, as the C / S ratio of the panel increased, it was estimated that the micropores were reduced and thus the strength was increased.

When using a porous raw material (FIG. 5b)), the bending strength of the panel showed the best bending strength characteristics when 20% of the porous raw materials were mostly added regardless of the type of the porous raw material. In particular, Pohang zeolite exhibited an excellent flexural strength of 62 kgf / cm2 under the 10% addition condition with excellent moisture absorption and moisture absorption properties. Also, when the diatomite was added 10% and the bentonite was added 10%, the pore size showed similar tendency, and the flexural strength characteristics (Pohang bentonite 10% -51kgf / ㎠, Cheorwon diatomaceous earth (P) -49kgf / ㎠) It is assumed to be similar. Wasser et al. Reported that the strength of a material is not determined solely by porosity, but that various variables affect the size and shape of the pores, the mineral composition and crystal phase of solids, and structural defects inside. The compressive strength was 120kgf / cm2 at 0.7 C / S ratio and 183kgf / cm2 at 10% Pohang zeolite.

The above experimental results are summarized as follows.

1) The moisture absorption and desorption characteristics of the panel were about 80 g / m 2, and the amount of moisture was about 40 g / m 2 under the C / S ratio of 0.7. However, the moisture absorption and desorption characteristics of the moisture were greatly improved according to the mixing of the porous raw materials. In the case of the 10% panel of Pohang zeolite, the moisture absorption amount was 180g / m 2 and the moisture absorption amount was 105g / m 2. In addition, the correlation between the specific surface area and pore volume of the panel and the moisture absorption amount was found to be about 0.52, and it was confirmed that there was some correlation between the specific surface area and the pore volume and the moisture absorption amount. In addition, the moisture absorption of the panel was different according to the type of porous raw material (especially Hwasun bentonite and Pohang zeolite), which was assumed to be due to the influence of the porous raw material.

2) Formaldehyde adsorption characteristics of the panel showed similar tendency to the adsorption characteristics of moisture depending on the pore and specific surface area, and in particular, the adsorption rate of formaldehyde was also fast in the case of Pohang zeolite panel.

1 is a graph showing the moisture absorption and moisture absorption characteristics of the panel with the C / S ratio changed,

2 is a graph showing moisture absorption and moisture absorption characteristics of a panel using a porous raw material (a is iron source diatomaceous earth (G), b is iron source diatomaceous earth (P), c is Chinese diatomaceous earth (W), d is Chinese diatomaceous earth (P), e Is Pohang bentonite, f is Hwasun bentonite, g is racing zeolite, f is Pohang zeolite)

3 is a graph showing formaldehyde adsorption characteristics of a panel having a C / S ratio varied;

4 is a graph showing formaldehyde adsorption characteristics of a panel using a porous raw material (a is iron source diatomaceous earth (G), b is iron source diatomaceous earth (P), c is Chinese diatomaceous earth (W), d is Chinese diatomaceous earth (P), e Is Pohang bentonite, f is Hwasun bentonite, g is racing zeolite, f is Pohang zeolite),

Figure 5 is an electron micrograph showing the microstructure of the panel according to the type and content of the porous raw material (a is iron source diatomaceous earth 10%, b is iron source diatomaceous earth 20%, c is Chinese diatomaceous earth 10%, d is Chinese diatomaceous earth 20%, e Is Pohang Bentonite 10%, f is Pohang Bentonite 20%, g is Pohang Zeolite 10%, h is Pohang Zeolite 10%),

6 is a graph showing the thermal conductivity of the panel according to the type and content of the porous raw material and the change in the C / S ratio, a is a graph according to the change in the C / S ratio and b is a graph according to the type and content of the porous raw material,

7 is a graph showing the pore characteristics of the panel according to the type and content of the porous raw material and the change in the C / S ratio, a is a graph according to the change in the C / S ratio and b is a graph according to the type and content of the porous raw material.

Claims (5)

A hydrothermal composite building panel capable of absorbing and absorbing formaldehyde, characterized by hydrothermal synthesis of a raw material mixture containing slaked lime, white cement and silica and a porous raw material. 2. The hydrothermal composite building panel as claimed in claim 1, wherein the raw material mixture contains hydrated lime, white cement and silica in a CaO / SiO ₂ ratio of 0.5 to 1.1. . 2. The hydrothermal composite building panel as claimed in claim 1, wherein the porous raw material is one or two or more mixtures selected from the group consisting of diatomaceous earth, bentonite and zeolite. The hydrothermal composite building interior panel according to claim 1, wherein the porous raw material is contained in an amount of 10 to 30% by weight in the raw material mixture. A method of manufacturing a hydrothermal composite interior panel capable of adsorbing formaldehyde and moisture absorption and moisture absorption according to claim 1.

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