JPS6227360A - Low-water absorption inorganic porous bead - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to low water absorption inorganic porous beads that are used as a heat insulating material used in construction materials and other various fields, or as a material for underwater floats. It is.

[Prior art]

BACKGROUND OF THE INVENTION Conventionally, many insulation materials used as building materials and other various fields are made from glass foam particles. For example, glass foam particles are used as a nonflammable inorganic heat insulating material by mixing them in concrete, or they are used as a material for building insulation materials or liquefied gas tank insulation materials as a burl charge. The main raw material of such foamed glass particles is glass powder, and generally inexpensive soda glass powder, especially soda glass powder made by effectively utilizing waste glass, is mainly used.

However, the soda glass foam particles mentioned above have a water absorption rate of 15
It has extremely high water absorption properties of ~20%. Therefore, mixing soda glass foam particles in concrete and using it as a building material has the disadvantage that the soda glass foam particles already contain and absorb a large amount of water when mixed with fresh concrete. Therefore, it is not preferable for application to building materials, etc. Further, when the above-mentioned foamed soda glass particles are used as a heat insulating material by burr charging, the thermal conductivity increases due to water absorption, and the function as a heat insulating material decreases. On the other hand, when the above-mentioned foamed soda glass granules are used as a material for insulation material for liquefied gas tanks, the water absorbed by the foamed soda glass granules is cooled by the low temperature of the liquefied gas, resulting in freezing and destruction of the foamed granules. This will lead to a situation like this. As mentioned above, foamed beads made only of soda glass have high water absorption and are not suitable for insulation materials, etc., so conventionally, the following method was used to absorb water into foamed glass beads made from soda glass powder. It is made to suppress sexuality.

(1) A method for producing foamed glass granules, in which hard glass is coated and foamed during granulation. Since the foamed glass beads produced by this method have a low coefficient of thermal expansion, cracks due to temperature changes during foaming are less likely to occur, and the water absorption rate decreases.

(2) A method for producing foamed glass granules in which glass (low softening point and low melting point) is coated and foamed during granulation. The glass foam particles produced by this method form a pure glass layer and are less prone to cracking, so glass crystallization is less likely to occur.

However, in both of the above conventional examples, the glass powder coated to suppress the water absorption rate during granulation to a low level during foaming! f:l+ may be separated or may peel off during drying, which is a pre-foaming step. Furthermore, it may be necessary to change the foaming conditions for soda glass alone, but in such cases, the soda glass foam beads and manufacturing method that have been produced up until now can be used as is. The problem is that it cannot be done. Furthermore, since coating during granulation is based on adhesion of solids to each other, there is also the problem that it takes too much effort to uniformly coat.

[Purpose of the invention]

The present invention has been made in consideration of the above conventional problems, and there is no risk that the coating layer will peel off during foaming or drying, and there will be no problem even if the foaming conditions are changed. The purpose of the present invention is to provide low water absorption inorganic porous beads that not only have low water absorption but also exhibit excellent functions as building materials, insulation materials, etc., and are suitable for mass production.

[Structure of the invention]

The low water absorption inorganic porous beads according to the present invention have water repellency and water resistance so that they enter the inside of the countless pores formed on the outer surface of the highly water absorbent inorganic porous particles at least from the periphery of each opening. It is characterized in that a coating agent is attached, thereby suppressing the water absorption rate to a low level.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

As shown in FIGS. 1 to 4, on the outer surface of soda glass foam particles 1 as inorganic porous particles having high water absorption,
(ΩA water-based and water-resistant coating agent 2 is adhered to the entire surface of the foamed soda glass particles 1. This coating agent 2 is applied from at least the periphery of each opening of the innumerable pores 3 formed on the outer surface of the soda glass foam particles 1. In other words, as shown in Fig. 5, in the case of a large hole 3a with a large opening area, the coating agent 2 flows into the inner part of the hole. Although the inner circumferential surface of the hole is coated without any gaps, the inner circumferential surface of the hole is large, so the coating agent 2 is not completely filled inside the hole, and the inner surface of the hole is medium in size. In the case of 3b, the coating agent 2 enters into the hole from the inner periphery of the hole to the vicinity of the entrance, but does not reach the deep inside of the hole. In the case of a small hole 3c with a relatively narrow inner part, the coating tends to be formed in such a manner that the coating agent 2 is completely filled inside the hole, but the state of adhesion of the coating agent 2 is All of these are included in the gist of the present invention. That is, the coating agent 2 does not need to be completely filled inside the hole 3. For example, in the case of the medium hole 3b, the coating agent 2 Agent 2 does not cover the entire inner peripheral surface of the hole, but even with such a structure, water is repelled near the opening by the tΩ aqueous nature of coating agent 2, so water is not absorbed into the hole. In the case of large hole 3a and small hole 3
In case c, since the inner circumferential surface of the hole is covered with the coating agent 2, there is no risk of water absorption. Note that the above hole 3 is the same whether it is a continuous hole or an independent hole.

As the coating agent 2, those having water repellency and water resistance, such as weak cationic/nonionic surfactants, polyethylene, wax polyethylene, paraffin containing zirconium salts, etc., are used.

As the coating agent 2 for coating the foamed soda glass particles 1, which are inorganic porous particles with high water absorption, from the outer surface, it is preferable to use an emulgene. After coating the outer surface of the foamed soda glass beads 1 with such an emulsion coating agent 2, it is dried to remove the solvent component of the emulsion, thereby causing the solid component coating agent 2 to adhere to the surface of the foamed beads 1. This is desirable, and this facilitates mass production. Specific examples of the above-mentioned coating methods include: ■ A method of immersing the foamed glass beads in a liquid of a coating agent; ■ A method of spraying the coating agent onto the outer surface of the foamed glass beads with a sprayer using a sugar-coating machine; ■ There is a method of applying a coating agent while moving the expanded granules using a sugar coating machine, and coating by the fluid movement of the coating agent.In addition, it is also possible to use a pan-type granulator in place of the sugar coating machine described above.

Note that the highly water-absorbing inorganic porous particles referred to in the present invention are not limited to the above-mentioned foamed soda glass particles, but may also be, for example, rocks such as pearlite.

[Experimental Example 1] As inorganic porous particles, the bulk density is approximately 0.22 g/cc
Using a sugar coating machine, a polyethylene emulsion (
100 g of Vermarin PN (manufactured by Sanyo Kasei) was added, and the glass foam particles were transferred for about 5 minutes to perform a coating process. Next, the thus coated expanded beads were dried at a temperature of about 50° C. for a day and night, thereby evaporating and removing the water in the emulsion. The low water absorption inorganic porous beads produced in this manner have a structure in which only the intended coating solid component is attached so as to cover the outer surface of the glass foam particles. Such low water absorption inorganic porous beads were used as a sample, and as a comparative sample, homogeneous expanded beads without coating were produced by the same procedure as above, including the drying process. Table 1 shows the results of measuring the water absorption rates of these non-coated expanded beads as blanks.

Table 1 Note that since the method for measuring water absorption rate is not standardized by JIS, the following method was adopted in this experiment for measurement.

Both samples above are soaked in water for 24 hours. After that,
Each sample was taken out of the water, washed with methyl alcohol (CH30H) to remove only the water adhering to its surface, and then placed in a constant temperature bath at 65°C for 10 minutes to measure its weight. The water absorption rate is the ratio of increased weight to the weight before the water absorption test. This also applies to Experimental Examples 2 to 5 shown below.

[Experimental Example 2] The coating agent used in Experimental Example 1 above (Vermarine P
N), a wax polyethylene emulsion (Vermarine EH-361, manufactured by Sanyo Kasei) was used, and coating and drying were performed in the same manner as in Experimental Example 1.
The results of measuring the water absorption rate are shown in Table 2. still,
The blank was the same as in Experimental Example 1.

Table 2 [Experimental Example 3] Coating agent used in Experimental Example 1 above (Vermarine P
N), a polyethylene emulsion (Vermarin FP-528, manufactured by Sanyo Chemical Co., Ltd.) was used, coating and drying was performed in the same manner as in Experimental Example I, and the water absorption rate was measured. The results are shown in Table 3. there were. Note that the blank was the same as in Experimental Example 1.

Table 3 [Experimental Example 4] Coating agent used in Experimental Example 1 above (Vermarine P
N), a zirconium salt-containing paraffin emulsion (Isotol H, manufactured by Sanyo Kasei) was used, and coating and drying were performed in the same manner as in Experimental Example 1.
The results of measuring the water absorption rate are shown in Table 4. still,
The blank was the same as in Experimental Example 1.

Table 4 [Experimental Example 5] Coating agent used in Experimental Example 1 above (Vermarine P
N), a lubricant containing a weak cationic/nonionic surfactant (Sunleaf CL-533, manufactured by Sanyo Chemical Co., Ltd.) was used, and coating and drying were performed in the same manner as in Experimental Example 1, and its water absorption rate was determined. The results of the measurements are shown in Table 5. Note that the blank was the same as in Experimental Example 1.

Table 5 [Effects of the Invention] As described above, the low water absorption inorganic porous beads according to the present invention can penetrate into the pores from at least the periphery of each opening of the numerous pores formed on the outer surface of the highly water absorbent inorganic porous particles. It has a structure in which a water-repellent and water-resistant coating is applied so that it penetrates into the body.

Therefore, the water absorption rate of beads is kept extremely low, and they exhibit excellent effects as materials for building materials, various insulation materials, underwater floats, and the like. Furthermore, since the structure is such that the coating agent is attached to the granules that have been foamed and dried, there is of course no risk of the coating agent peeling off during foaming or drying. Even if foaming is performed by changing the foaming conditions, there will be no problem with the adhesion of the coating agent.

Furthermore, if the structure of the present invention is adopted, the coating agent can be applied uniformly easily and in a short time, and mass production becomes possible.

[Brief explanation of drawings]

Figure 1 shows an example of the present invention, and is an external view of the outer surface of low water absorption inorganic porous beads (coated with Isotol H), magnified with a microscope. An enlarged external view, Fig. 3 is an enlarged microstructure diagram of the cross section of the same low water absorption inorganic porous beads near the surface, Fig. 4 is a replica of Fig. 3, and Fig. 5 is the same bead. FIG. 1 is a soda glass foam particle, 2 is a coating agent, and 3 is a hole. Patent applicant Sekisui Plastics Co., Ltd. Figure 3 Figure 4 Figure 5 u
,,/November 8, 1985 Michibe Uga, Commissioner of the Patent Office, 1985 Patent Application No. 163578 2, Title of Invention: Low Water Absorption Inorganic Porous Beads 3, Relationship with Amendment Case Patent Applicant Address: 25 I-chome, Nankin-Takumachi, Nara City Name (244)
) Sekisui Plastics Co., Ltd. Representative Kawamoto
Mitsugu 4, Agent 8530 Address 2-4-17 Tenjinbashi, Kita-ku, Osaka (Delivery date
(October 29, 1985) 6. Subject of amendment (1) "Brief explanation of drawings" column 7 of the specification, contents of amendment (1) Page 13, line 20 to page 14 of the specification 5
The line ``Figure 1 shows an embodiment of the present invention, . . . an enlarged tissue diagram near the surface'' is corrected as follows. Figure 1 shows an embodiment of the present invention, and is a substitute for a drawing of the particle structure of the outer surface of low water absorption inorganic porous beads (coated with isotol H) enlarged with a microscope. Figure 2 is a photograph showing a part of the bead shown in Figure 1, which is a further enlarged view of the particle structure. Figure 3 is a cross-section of the same bead, showing the structure near the surface of the particle. "Photographs instead of drawings showing the structure"

Claims (1)

[Claims] 1. A low water absorption product characterized by having a coating agent having water repellency and water resistance attached so as to enter from at least the periphery of each opening of the numerous pores formed on the outer surface of the highly water absorbent inorganic porous particles. Inorganic porous beads.