JPH0930821A - Glass foam granule, method for producing the same, lightweight filler and lightweight plastic using the same - Google Patents

Abstract

(57) [PROBLEMS] To provide a glass foam granule having improved strength, a method for producing the same, a lightweight filler using the same, and a lightweight plastic. A glass foam granulated body 1 in which a large number of closed cells 3 are dispersed in foamed granules. Since the partition wall 2 is provided, the strength is improved. For example, a method for producing a glass foam granule in which automobile glass is made into powder particles and a foaming agent made of, for example, dolomite is kneaded, melted, and foamed. This glass foam granule can be used as a lightweight filler, and it is kneaded with resin powder granules,
By molding, a lightweight plastic having a specific gravity of 0.7 to 0.8 can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass foam granule, a method for producing the same, a lightweight filler exclusively utilizing the properties of the glass foam granule, and a lightweight plastic containing the glass foam granule.

[0002]

2. Description of the Related Art Conventionally, hollow foamed granules (baluns) mainly made of glass include silica baluns, silas baluns, and pearlite baluns. The characteristic of silica-based balun is 20μm ~ 1
It has a fine particle size of 30 μm, has high compressive strength, does not react with water or resin, has high chemical stability, has low heat conduction, and has excellent heat insulating properties. Further, the characteristics of the shirasu-based and perlite-based baluns are that they are lighter than the silica-based baluns, that they use natural raw materials, that the water of crystallization in the raw materials is gasified, and foams.

[0003]

However, the prior art has the following problems. 1. The cost of silica-based balun is high (for example, 10
(00 to 1500 yen / kg). 1) The balunization process of silica-based balun is as shown in FIG. 9, and the balunization equipment becomes complicated by the flame method and the cost of balun becomes high. 2) The portion heated at a high temperature of 1,100 ° C. is foamed by staying for a very short time of 0.5 to 10 seconds. Therefore, since the temperature inside the furnace is high, the equipment cost is high and the energy cost is high. 3) Due to the high temperature, it is difficult to control the temperature inside the furnace and the recovery rate is poor.
That is, since the temperature fluctuation range during the flame is large, the degree of foaming is likely to differ for each grain, quality variations occur, and the recovery rate of the required quality balun decreases. Therefore, it becomes expensive. 4) An organic type is used as the foaming agent. Therefore, the foaming agent escapes considerably during the spray-drying granulation, resulting in loss. Further, the gas generation decomposition temperature is about 200 ° C, and the spray drying temperature is 1
The temperature is 80-370 ℃, and the price is high due to the high temperature (800
/ Kg). 2. Since the balun particle size (30 to 120 μm) is fine particles, it easily scatters during the manufacturing process, handling and use. 3. Natural materials are used for shirasu and perlite. Due to the difference in mineral composition depending on the place of origin, it is necessary to investigate and select raw material characteristics by place of origin, resulting in different yields and strengths. In addition, the melting temperature is high and the foaming is performed at 1,000 to 1,200 ° C. An object of the present invention is to produce a foamed granule mainly composed of glass, which can be manufactured at a lower temperature than conventional ones, and thus can be manufactured at low cost, has stable quality, and has improved strength, a method for manufacturing the same, and a foamed granule. An object of the present invention is to provide a lightweight plastic material containing properties and a lightweight plastic containing expanded granules.

[0004]

The present invention to achieve the above object is as follows. (1) A glass expanded granulated product characterized in that a large number of closed cells are dispersed in expanded beads by mixing glass with a foaming agent and foaming the glass as a main material. (2) A glass characterized by mixing crushed glass and at least a foaming agent, adding a solvent to the mixture to granulate it, drying it, and heating the dried granulated body to foam it. Method for producing expanded granules. (3) The method for producing a glass foam granule according to (2), wherein glass that starts softening at about 700 ° C. or less is used as the glass, and dolomite is used as the foaming agent. (4) The heating temperature in the heating and foaming process is 730 ° C to
The method for producing a glass foam granule according to (2), wherein the specific gravity and the strength are set to 900 ° C. and the heating time is adjusted within the range of 10 seconds to 20 minutes. (5) A lightweight filler made of a glass foam granule in which a large number of closed cells are dispersed in foam particles by mixing glass with a foaming agent to foam the glass as a main material. (6) A lightweight filler made of glass foam granules in which a large number of closed cells are dispersed in foam particles by mixing glass with a foaming agent to foam the glass as a main material,
Lightweight plastic made by kneading, heating, and molding with resin powder.

The glass foam granule of the above (1) has a partition wall between the air bubbles in the granule and has a higher strength than a conventional hollow granule. According to the method (2) for producing a glass foam granule, it is possible to manufacture a high strength glass foam granule having partition walls between cells in the granule. In the method of (3) above, glass that starts softening at about 700 ° C. or lower is used as glass (for example, automobile glass), and dolomite (foaming at about 700 ° C. to 750 ° C.) is used as a foaming agent. 7
Glass can be melted and foamed at 30 ° C to 900 ° C, the temperature is lower than in the past, the temperature control in the furnace is stable, the quality is stable, and the recovery efficiency is high. Therefore, the product cost can be reduced. In the above method (4), the heating temperature and the heating time can be adjusted to adjust the specific gravity and strength of the glass foam granule. Above (5)
In, it is possible to provide a lightweight filler using a glass foam granule. In the above (6), a lightweight plastic can be provided by using the lightweight filler.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION First, a method for producing a glass foam granule according to an embodiment of the present invention will be described. The composition in the production of the glass foam granules is as follows. Glass is used as the main raw material with an appropriate amount of additives, and a particle size of 5
A glass foam granule (light weight filler) of 0 to 600 μm is manufactured. The composition is glass as the main raw material, dolomite (MgCO ₃ · CaCO ₃ ) as the foaming agent, and borax (Na ₂ B ₄ ) as the flux.
O ₇ .5H ₂ O) are mixed in the weight ratio shown in Table 1. Dolomite foams at about 700 ° C to 750 ° C.

[0007]

[Table 1]

As the glass, it is possible to use a glass which starts to soften at about 700 ° C. or lower, for example, automobile glass (for example, a glass of a scrap car). Dolomite is a natural product and an inexpensive material. In addition, foaming gas (carbon dioxide gas CO ₂ ) is generated in the temperature range in which the glass softens. Borax is added to adjust and lower the melting point of glass. For example, as shown in FIG. 1, the melting state of automobile glass is a melting start temperature of 550 ° C. to a melting temperature of 700 ° C. When 5% borax is added, the melting state of automobile glass is 530 ° C.
~ The melting temperature is 685 ° C. The foaming state of dolomite due to temperature rise is from a decomposition start temperature of 620 ° C to an end temperature of 730 ° C. However, if borax is added in an amount more than the necessary amount, the viscosity of the molten glass will decrease during heating, and the release agent for preventing fusion will tend to adhere to the balun and the specific gravity may increase.

The steps of crushing, granulating, heating and foaming glass in the production of a glass foam granule will be described with reference to FIG. As shown in Fig. 2, the manufacturing method is pulverization in which each raw material is mixed,
The mixture is granulated, dried to heat and foamed to be granulated. The glass is crushed with a ball mill, and the average particle size is 3 to 10 μm.
After adjusting to m, the blended ingredients are uniformly mixed to form a powdery mixture. Granulation and drying are performed by a tumbling mixer method or a spray dryer spray drying method. In the case of a tumbling mixer, the mixture does not lose its shape when mixed with water to form a granulated product having a water content of 15 to 18% and then dried. In the case of the spray drying method, the mixture is mixed with water as a solvent and used as a slurry having a water content of 32 to 38%. When granulating, a binder agent for binding is generally used, but the glass powder has a cohesive force when moist and does not require the addition of a binder agent. Heating and foaming are performed by a rotary furnace method or a flame method. If there is fusion between the furnace wall and the particles, a release agent is added if necessary. In order to prevent a decrease in specific gravity due to adhesion of balun, it is preferable that the release agent be an inorganic one having a low specific gravity. For example, hydrangea and alumina. The granulated material is heated at a temperature of 730 to 900 ° C. (in the case of scrap car glass, it melts at a relatively low temperature) and a time of several tens of seconds to 20 minutes (longer than conventional ones,
The heating is stable and the quality is stable), the glass is melted and the foaming gas is generated, and the foaming gas is taken into the glass and foam-granulated. In the case of the flame method, in order to prevent cracking due to rapid heating, it is preferable to heat the glass at a temperature at which the glass does not melt before charging the flame, so that the foaming efficiency is good. Thus, a glass foam granule is manufactured.

Next, the glass foam granules and their characteristics will be described.
This will be described with reference to FIGS. 3 and 5 to 7. As shown in FIG. 3 in an enlarged manner, the manufactured glass foam granules 1 are one sphere composed of a collection of minute closed cells 3 separated by several walls 2. The partition walls 2 in this granule are advantageous in terms of compressive fracture strength (increase in strength). Also, even if some bubbles are broken when used as a lightweight filler, other bubbles still remain, which is on the safe side. 50-600μ in outer diameter
m spherical shape can be manufactured. FIG. 4 shows an enlarged view of a conventional balun (hollow granule) 1 '.

Mechanical properties when the glass foam granules of the examples of the present invention were manufactured using automobile glass are shown in FIG.
As shown in FIG. The particle size is manufactured to 300 to 600 μm. As shown in these graphs, by changing the manufacturing conditions such as heating temperature and heating time, it is possible to freely manufacture and select the one having the required compressive fracture strength and specific gravity within the graph range.

Next, a description will be given of a weight-reducing filler material that exclusively utilizes the specific property of the foamed glass granules that is lightweight. Glass foam granules can be used as a lightweight filling material,
Its usage is to add it to a resin and mold it to obtain a filler that can reduce the weight of plastic. The resin may be a waste resin. The lightweight plastic is manufactured by the process shown in FIG. It is advisable to select a glass foam granule having a compressive fracture strength that does not break during the production of a lightweight plastic, and to determine the addition amount so that the required plastic specific gravity can be obtained. The resulting lightweight plastic is
It has high strength and rigidity. For example, as shown in Table 2, polypropylene resin (specific gravity 0.91) has a specific gravity of 0.5
By mixing and molding the glass foam granules of (3) at a weight ratio of 7: 3, a lightweight plastic having a specific gravity of 0.73 is produced.

[0013]

[Table 2]

[0014]

According to the glass foam granules of claim 1,
Since the closed cells are formed by dispersing the closed cells in the foamed particles, it is possible to provide a granulated body having an increased strength due to the partition walls between the cells. According to the method for producing a glass foam granule of claim 2,
Granules containing closed cells can be produced. According to the method for producing a glass foam granule according to claim 3, a glass which starts softening at 700 ° C. or lower (for example, automobile glass).
Since dolomite is used as the foam material, it can be melted and foamed at a lower temperature (about 730 ° C. to 900 ° C.) than conventional ones, and a high-quality and low-cost glass foam granule can be provided. . According to the method for producing a glass foam granule of claim 4, the heating temperature is in the range of 730 to 900 ° C,
By changing the heating time in the range of 20 minutes to 10 seconds,
The breaking strength of the glass foam granules is 20 to 300 kg / cm
^It can be freely changed within the range of ² cm and the specific gravity is 0.3 ~
It can be changed freely within the range of 1.0. According to the lightweight filler made of the glass foam granules according to the fifth aspect, the resin molded product and the like can be lightened by being mixed with resin or the like and molded. According to the lightweight plastic of the sixth aspect, the lightweight plastic having a specific gravity of, for example, 0.7 to 0.8 can be provided by using the lightweight filler.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the heating temperature (melting temperature, melting start temperature) and the amount of borax added in a mixture of automobile glass, dolomite, and borax.

FIG. 2 is a process drawing of a method for manufacturing a glass foam granule according to an example of the present invention.

FIG. 3 is an enlarged cross-sectional view of one grain of a glass foam granule according to an example of the present invention.

FIG. 4 is an enlarged cross-sectional view of one grain of a conventional glass balun (commercially available product).

FIG. 5 is a graph showing the relationship between the compressive fracture strength and the specific gravity of one grain of the glass foam granules of the examples of the present invention.

FIG. 6 is a graph showing the relationship between the specific gravity of one particle of the glass foam granulated material of the example of the present invention and the heating temperature.

FIG. 7 is a graph showing the relationship between the compressive fracture strength and the heating temperature of the glass foam granules of the examples of the present invention.

FIG. 8 is a manufacturing process diagram of a lightweight plastic using a lightweight filler mainly composed of a glass foam granule according to an example of the present invention.

FIG. 9 is a manufacturing process of a conventional silica balun.

[Explanation of symbols]

 1 glass foam granules 2 partition walls 3 bubbles

Claims (6)

[Claims] 1. A glass foam granule characterized in that a large number of closed cells are dispersed in foam particles by using glass as a main material and mixing a foaming agent with the glass to foam the glass. 2. A method in which crushed glass and at least a foaming agent are mixed, a solvent is added to this to granulate, and this is dried, and the dried granulated body is heated to foam. A method for producing a glass foam granule. 3. The method for producing a glass foam granule according to claim 2, wherein the glass used is a glass which starts softening at about 700 ° C. or lower, and dolomite is used as the foaming agent. 4. The heating temperature in the heating and foaming process is 73.
The method for producing a glass foam granule according to claim 2, wherein a desired specific gravity and strength are obtained by adjusting the heating time in the range of 0 ° C to 900 ° C for 10 seconds to 20 minutes. 5. A lightweight filler made of glass foam granules having glass as a main material and a large number of closed cells dispersed in the foam particles by mixing the foaming agent and foaming. 6. A lightweight filler made of a glass foam granule having glass as a main material and a large number of closed cells dispersed in the foam particles by mixing the foaming agent and foaming the mixture. Lightweight plastic made by kneading, heating, and molding with resin powder.