JP2003002729A - Inorganic building material and production method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the cost of the raw material for reducing the cost of inorganic building materials, particularly, to reduce the cost of a silica material, and to effectively recycle the scrap wood of alkali-free glass, particularly, glass for a liquid crystal display panel. SOLUTION: The inorganic building materials contain alkali-free glass containing, by mass, <=5% alkali metal oxide, >=50% SiO2 , 5 to 30% Al2 O3 , 0 to 20% B2 O3 and 5 to 40% alkaline-earth metal oxide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inorganic building material using non-alkali glass and a method for manufacturing the same, and more particularly to an inorganic building material mainly using non-alkali glass waste and a method for manufacturing the same.

[0002]

2. Description of the Related Art As an inorganic building material, in addition to ash brick, concrete pile, precast panel, lightweight cellular concrete panel (ALC panel), fiber reinforced cement board represented by calcium silicate board (JIS A543).
0), ceramic siding (JIS A5422), wood cement board (JIS A5417), and the like.

Cement and lime are the main raw materials for the above-mentioned inorganic building materials, to which an appropriate amount of siliceous material is added. As the siliceous material, fine grain silica sand, fly ash, diatomaceous earth or crushed slag, etc. are used. In addition to these materials, it is common to mix a fibrous material as a lightweight aggregate or boards for compensating the defects of brittle materials.

These raw materials are mixed with an appropriate amount of water to form a slurry, which is then cast into a mold, a papermaking method, an extrusion method,
It is molded by a molding method such as a pressing method and then cured at 100 to 200 ° C. by an autoclave. By this autoclave curing, various calcium silicate hydrates such as tobermorite are produced. In order to reduce the cost of these inorganic building materials that are autoclave curing products, inexpensive raw materials have been required. In particular, cost reduction of siliceous materials has been an important issue.

On the other hand, non-alkali glass substrates are widely used as glass substrates for liquid crystal display panels. Although edge loss, defective products, and the like occur in the glass substrate production process, techniques for returning these to the kiln as glass raw materials are being established.

However, the drain out loss discharged from the melting kiln (the loss caused by discarding the glass contaminated by the erosion of the furnace material) is returned to the kiln as a glass raw material because it contains impurities in the furnace material. I can't
It had to be disposed of as industrial waste.

Also, defective products are generated in the production process of liquid crystal display panel manufacturers. Since these are provided with a color filter and an ITO film, it was difficult to return them to a kiln as glass raw materials and regenerate them as glass.

Up to now, regarding the use of waste glass materials,
For example, Japanese Patent Application Laid-Open No. 11-199294 discloses a method of mixing a waste glass material into a special concrete composition as an aggregate to prepare a road paving material or other civil engineering material, and Japanese Patent Application Laid-Open No. 2000-144743 discloses A lightweight soil cement in which a cement-based solidifying agent is added to a mixed soil of a crushed glassy foam and soil, which is obtained by adding a foaming material to a waste glass material and heat-treating it, is disclosed. Further, as a method for discarding a liquid crystal display panel, Japanese Patent Laid-Open No. 2000-8
4531 discloses that a waste liquid crystal panel is crushed by a uniaxial shearing crusher and then put into a non-ferrous smelting furnace at about 1200 ° C. to be used for iron removal processing. However, few have been put to practical use, and further applications for recycling have been desired.

In recent years, the increase of industrial waste is a social problem, and the governmental trend is that activities such as the Container and Packaging Recycling Law and the Home Appliance Recycling Law are becoming active. Therefore, reducing or recycling the above-mentioned industrial wastes is an essential issue due to the demands of the times.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems. In other words, the former issue is to reduce the cost of raw materials for cost reduction of inorganic building materials, especially the cost of siliceous materials, and effectively recycle waste materials of alkali-free glass, especially glass for liquid crystal display panels. The purpose is to do.

[0011]

According to the present invention, an alkali metal oxide is 5 mass% or less, SiO ₂ is 50 mass% or more, and A
Provided is an inorganic building material characterized by containing an alkali-free glass containing 5 to 30% by mass of l ₂ O ₃ , 0 to 20% by mass of B ₂ O ₃ , and 5 to 40% by mass of an alkaline earth metal oxide. To do. The present invention also provides an inorganic building material, characterized in that the total amount of the alkali-free glass and cement is 50% by mass or more, the admixture is 0 to 40% by mass, and the reinforcing fiber is 2% by mass or more.

Thus, the waste material of alkali-free glass, especially alkali-free glass for liquid crystal display panels, can be recycled and used as a raw material for the inorganic building material. In particular, an inorganic building material containing a total amount of alkali-free glass and cement of 50 mass% or more, an admixture of 0 to 40 mass% and a reinforcing fiber of 2 mass% or more is a ceramic siding defined by the Japan Ceramic Exterior Materials Association. As a typical example, an exterior material belonging to fiber-mixed cement / calcium silicate board is widely used.

In the present invention, the inorganic building material is preferably cured by autoclave curing.

Thus, a waste material of alkali-free glass, especially alkali-free glass for liquid crystal display panels, can be recycled and used as a raw material for an inorganic building material which is an autoclave curing product.

In the present invention, non-alkali glass means that the total amount of alkali metal oxides is 5% by mass or less, SiO 2
₂ means glass having a composition of 50% by mass or more. The alkali metal oxide refers to Li ₂ O, Na ₂ O, K ₂ O and the like. Alkaline earth metal oxides are MgO, CaO, S
It is a general term for rO, BaO and the like, and in the present invention, the total amount of one or more of these may be 5 to 40% by mass.

Specific examples of the admixture include calcium carbonate, perlite, mica, wollastonite, magnesium carbonate, vermiculite, shirasu balloon, zeolite, granular organic foam, coloring material, thickener and the like. Specific examples of the reinforcing fiber include organic fibers made of polyethylene, polypropylene, vinylon, acrylic, aramid, cellulose and the like, and inorganic fibers made of glass, rock wool, carbon, steel and the like.

The present invention also provides alkali metal oxides of 5
Mass% or less, SiO ₂ 50 mass% or more, Al ₂ O ₃ 5
30 wt%, the B ₂ O ₃ 0 to 20 wt%, the alkaline earth metal oxides was pulverized alkali-free glass containing 5 to 40 wt% and the siliceous material, other constituting the inorganic building materials thereto There is provided a method for producing an inorganic building material, which comprises adding the above-mentioned component and water, mixing and molding, and then subjecting to autoclave curing. In the above manufacturing method, water may be added to and mixed with the components constituting the inorganic building material to form a slurry, the slurry is dehydrated and molded, and then autoclave-cured.

The other components constituting the inorganic building material differ depending on the type of the inorganic building material, but include, for example, main components such as cement and lime, aggregates and reinforcing fibers added as necessary. Further, the molding method of an inorganic building material refers to a molding method such as a method of casting slurry or raw material powder into a mold, a papermaking method, an extrusion method, a press molding method, or the like.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION In the glass used for the inorganic building material of the present invention, it is essential that the alkali metal oxide content is 5% by mass or less.

When the content of alkali metal oxide is more than 5% by mass, for example, soda lime type glass (containing 10% or more of alkali metal oxide) such as general architectural glass and automobile glass is powdered. As a state, when the inorganic building material manufactured using this as a siliceous raw material is immersed in water,
A large amount of alkali metal oxides is eluted, causing a problem that the drying shrinkage after immersion in water becomes large.

Further, the alkali metal oxide in the inorganic building material reacts with carbon dioxide in the air to cause a white sinter phenomenon on the surface of the inorganic building material to cause stains, or carbonates in the inorganic building material. There is a problem that it is generated and causes contraction. Therefore, the glass composition needs to have an alkali metal oxide content of 5% by mass or less, and the smaller the amount of alkali metal oxide, the better.

On the other hand, in the alkali-free glass used for the inorganic building material of the present invention, it is essential that the content of SiO ₂ is 50% by mass or more. SiO ₂ content is 5
If it is less than 0% by mass, sufficient strength cannot be obtained even if calcium silicate hydrate is produced by autoclave curing.

The alkali-free glass used in the inorganic building material of the present invention is not particularly limited, but use of waste materials discharged from various production processes reduces the cost as well as the industrial waste. preferable. Examples of waste materials of non-alkali glass include drain out loss of a glass melting furnace, edge loss of glass substrate or defective product, defective product of liquid crystal display panel, and the like.

Here, the drain out loss of the glass melting furnace means a loss caused by discarding the glass contaminated by the erosion of the furnace material. The edge loss of the glass substrate means, for example, a loss caused by discarding both end portions of the glass ribbon (having a larger plate thickness than other portions of the glass ribbon), which occurs when the glass ribbon is formed by the float method. Defective liquid crystal display panels include such as defective display panels. In addition, scrap materials around the glass substrate are also treated as waste materials.

When non-alkali glass is used as a waste material, the glass plate is roughly crushed into suitable pieces and then crushed by a vertical mill, a centrifugal roller mill, a ball mill, a vibration mill or the like. The average particle diameter (D50) of the alkali-free glass may be adjusted according to the purpose of use and is not particularly limited, but if it is about 1 to 100 μ, the reaction in autoclave curing becomes easy. Are particularly preferred.

The inorganic building material of the present invention contains silica brick.
In addition to concrete piles, precast panels, lightweight cellular concrete panels (ALC panels), fiber reinforced cement boards represented by calcium silicate boards (JIS A5
430), ceramic siding (JIS A542)
2), wood chip cement board (JIS A5417), and other applications to boards, etc.

It is also possible to use the alkali-free glass of the present invention as a simple aggregate in an inorganic building material which is hardened by wet curing or underwater curing under normal pressure.

In the present invention, the alkali-free glass powder functions as a siliceous raw material, and by autoclave curing, mainly tobermorite C ₅ S ₆ H ₅ has a low crystalline C content.
SH, Gyro light C ₂ S ₃ H _2, Affi write C ₃ S ₂
H _3, hydration products, such as fins Blanc phosphoramidite C ₂ SH are obtained. These products are CaO in cement or lime, depending on the size of the SiO ₂ molar ratio of the siliceous raw material.
And coexist or exist independently.

The alkali-free glass is usually contain Al ₂ O _3, in the tobermorite serving as the center of the product, add Al ³⁺ within the structure by substitution reaction between the Si ⁴⁺ and Al ³⁺ be able to. Alkali metal oxides in cement and lime accelerate this substitution reaction, which promotes crystallization of tobermorite. Zonotolite C ₆ S ₆ H is also a typical hydrate obtained by autoclave curing, but since alkali-free glass contains a large amount of Al ³⁺ , it is thought that it promotes tobermorite formation and is not suitable as a raw material for xonotlite. To be

The abbreviation used here is a method generally used in the field of cement industry, and C is Ca.
O represents S ₂ , SiO ₂ represents H, and H represents H ₂ O.

As described above, in an inorganic building material mainly composed of calcium silicate-based hydrates centering on tobermorite, alkali-free glass functions as a general siliceous raw material, and its basic performance as a building material is comparable. Things are obtained.

In the inorganic building material of the present invention, the content of the alkali-free glass varies depending on the type of the inorganic building material, but may be an amount that replaces a part or all of the commonly used siliceous raw materials.

[0033]

EXAMPLES Examples of the present invention and comparative examples will be described below.

[First Example and Comparative Example] A waste material of alkali-free glass discharged from a glass substrate production process for a liquid crystal display panel was crushed by a ball mill to obtain powder having an average particle diameter (D50) of 10 μm. did. 35% by mass of this alkali-free glass powder as a siliceous raw material,
40% by weight of cement, 10% by weight of calcium carbonate,
A mixture containing 9% by mass of pearlite and 6% by mass of pulp was mixed with water to form a slurry, and the slurry was dehydrated and then molded into a plate having a thickness of 12 mm by a pressing method. This plate-shaped body was autoclaved at 160 ° C. for 9 hours, and dried at 105 ° C. so as to be in an absolutely dry state.
As the siliceous raw material used in the first example, alkali-free glass having two compositions shown in Table 1 was used (alkali-free glass 1 and alkali-free glass 2).

As a siliceous raw material used in Comparative Examples,
Glass A containing a large amount of silica sand and alkali metal oxides,
Glass B was crushed to prepare particles having a particle size of 10 to 30 μm. The compositions of these siliceous raw materials are also shown in Table 1. These siliceous raw materials were also formed into a plate-like body by the same composition and method as in the examples.

The obtained plate-shaped body was cut into a size of 50 × 50 mm to obtain a test body. 70m in this container
It was immersed in 1 l of distilled water and left standing at room temperature for 30 days.
This immersion water is sampled for high-frequency plasma spectroscopic analysis (IC
P) was used to measure the elution concentration of Na ions, and the mass reduction rate after immersion in water was also measured. The results are shown in Table 2.

[0037]

[Table 1]

[0038]

[Table 2]

From the results shown in Table 2, as compared with the case where soda lime glass containing a large amount of alkali metal oxides (Examples 4 and 5) was used as the siliceous raw material, waste materials of alkali-free glass (Examples 1 and 5) were obtained. It was found that the Na ion elution concentration was lower when 2) was used. That is, in the examples of the present invention, the elution amount of Na ions is small and the mass reduction rate is also small. These values are at the same level as when silica sand is used as the siliceous raw material.

[Second Embodiment and Comparative Example] A glass filter waste material with a color filter or an ITO film waste material with an ITO film (not including liquid crystal) discharged from the production process of a liquid crystal display panel is crushed and then ball-milled. Was pulverized to obtain a powder having an average particle diameter (D50) of 10 μ. 35% by mass of the alkali-free glass powder as a siliceous raw material, 40% by mass of cement, 10% by mass of calcium carbonate, 9% by mass of pearlite, and 6% by mass of pulp are added to the composition. A slurry was prepared by mixing with water, and the slurry was dehydrated and then pressed to form a plate-like body having a thickness of 12 mm.

The plate-shaped body was autoclaved at 160 ° C. for 9 hours, and dried at 105 ° C. so that it was in an absolutely dry state.
As a second example, a plate-like body was prepared using two kinds of non-alkali glass waste materials as a siliceous raw material (Examples 6 and 7). However, the detailed composition of these alkali-free glasses is unknown.

With respect to the obtained plate-like body, a bending strength test,
A water absorption dry length change test and a carbonation length change test were performed, and the results shown in Table 3 were obtained. As a comparative example, Table 1
When silica sand, glass A, and glass B having the composition shown in Table 2 are used as siliceous raw materials (these siliceous raw materials are also formed into a plate-like material by the same composition and method as in Examples, and Examples 3 and Example in Table 2 are shown. 4, the same composition as in Example 5) is also shown.

[0043]

[Table 3]

The test methods for the physical properties shown in Table 3 were carried out as follows. Bending test Bending strength was determined by the method shown in JIS A 1408.
The size of the test piece was No. 3 test piece (50 × 40 cm), the crosshead speed was 5 mm / min, and the bending strength was obtained from the load at the time of breaking. The values shown in the table are average values of 40 test bodies.

Water Absorption / Drying Length Change Test The size of the test piece was 150 × 150 mm. A gauge plug was set to 100 mm, and a pair of gauge plugs were attached to the front and back surfaces of the test piece in the orthogonal direction with a water-resistant epoxy resin adhesive.
After the adhesive was sufficiently cured, the test body was immersed in water at 20 ° C. for 8 days, and then the gauge length L ₁ was measured with a contact gauge. Then, the test body was dried at 60 ° C. for 7 days, and the gauge length L ₂ was measured. From this result, the dry shrinkage ratio after water absorption was determined by the following formula. Dry shrinkage ratio (%) = L ₁ −L ₂ The values shown in the table are average values of 20 test pieces.

Carbonation Length Change Test The size of the test body was 150 × 150 mm. A gauge plug was set to 100 mm, and a pair of gauge plugs were attached to the front and back surfaces of the test piece in the orthogonal direction with a water-resistant epoxy resin adhesive.
Moisture content of the test body is 10% after the adhesive is fully cured
Was adjusted in a constant temperature and constant humidity chamber. The gauge length L _C0 at the time when the water content became stable was measured with a contact gauge.
After that, the test body was allowed to stand for 14 days under the conditions of CO ₂ concentration of 10% and humidity of 50 to 60% to measure the gauge length L _C1 . The carbonation shrinkage rate was calculated by the following formula. Carbonation shrinkage (%) = L _C0 −L _C1 The values shown in the table are average values of 20 test specimens.

From the results shown in Table 3, when soda lime type glass containing a large amount of alkali metal oxide is used as the siliceous raw material (Examples 4 and 5), the bending strength is the same as that of the conventional silica sand as the siliceous raw material. Although it is almost the same as that in the case of the above, it is understood that the drying shrinkage rate and the carbonation shrinkage rate are larger than those when the conventional silica sand is used as the siliceous raw material (Example 3).
Therefore, it is expected that a problem will occur in terms of durability.

On the other hand, in the examples (Examples 6 and 7) of the present invention in which the liquid crystal panel waste material was used as the siliceous raw material,
Bending strength, dry shrinkage and carbonation shrinkage,
When conventional silica sand is used as the siliceous raw material (Example 3)
It turns out that it is almost equivalent to. Therefore, it was found that the alkali-free glass of the liquid crystal panel waste material in the example of the present invention can function as a siliceous raw material, and when used as a building material, the performance comparable to that of the conventional product can be obtained.

[0049]

According to the present invention, even if a non-alkali glass waste material, a color filter or a liquid crystal panel waste material with an ITO film discharged from a glass substrate production process of a liquid crystal panel is used as a siliceous raw material, compared with the case of general silica sand. Inorganic building materials can be obtained that are comparable to each other. Therefore, by using these waste materials, the cost of the conventional siliceous raw material can be significantly reduced. Further, drain out loss, edge loss, defective products, and defective liquid crystal panel waste materials discharged from the alkali-free glass melting kiln, which has been disposed of as industrial waste, can be effectively used as a silica-based raw material for inorganic building materials.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazutaka Otsuka             1-1 Suehiro-cho, Tsurumi-ku, Yokohama-shi, Kanagawa               Asahi Glass Co., Ltd. (72) Inventor Hideki Kushigaya             1-1 Suehiro-cho, Tsurumi-ku, Yokohama-shi, Kanagawa               Asahi Glass Co., Ltd. (72) Inventor Motsuzuki Itsuo             1-1 Suehiro-cho, Tsurumi-ku, Yokohama-shi, Kanagawa               Asahi Glass Co., Ltd. (72) Inventor Yusuke Nagato             1150 Hazawa-machi, Kanagawa-ku, Yokohama-shi, Kanagawa             Asahi Glass Co., Ltd. F-term (reference) 4G012 PA15 PA17 PA22 PA23 PA25                       PE03 PE06

Claims (6)

[Claims] 1. An alkali metal oxide of 5 mass% or less, Si
O ₂ to 50% by mass or more, the Al ₂ O ₃ 5 to 30 wt%, B ₂
0 to 20 mass% of O ₃ and 5 to 5 of alkaline earth metal oxide
An inorganic building material containing 40% by mass of non-alkali glass. 2. An inorganic building material comprising a total amount of the alkali-free glass and cement of 50% by mass or more, an admixture of 0 to 40% by mass, and a reinforcing fiber of 2% by mass or more. 3. An inorganic building material produced by including a siliceous material and cement as a raw material, wherein the siliceous material contains 5% by mass or less of an alkali metal oxide, 50% by mass or more of SiO ₂ and 5% by weight of Al ₂ O ₃ . 30 wt%, B ₂ O ₃ 0-2
An inorganic building material, which is an alkali-free glass containing 0% by mass and 5 to 40% by mass of an alkaline earth metal oxide. 4. The inorganic building material according to claim 1, 2 or 3, which is obtained by curing an inorganic building material raw material by autoclave curing. 5. The alkali-free glass according to claim 1, 2, 3 or 4, which is one of a drain out loss of a glass melting furnace, an edge loss of a glass substrate or a defective product, and a defective liquid crystal display panel. Inorganic building materials. 6. An alkali metal oxide of 5 mass% or less, Si
O ₂ to 50% by mass or more, the Al ₂ O ₃ 5 to 30 wt%, B ₂
0 to 20 mass% of O ₃ and 5 to 5 of alkaline earth metal oxide
A method for producing an inorganic building material characterized by crushing alkali-free glass containing 40% by mass into a siliceous raw material, adding the other components constituting the inorganic building material and water to the mixture, molding the mixture, and then curing it in an autoclave. .