JPH068191B2 - Crystallized glass material having black spot pattern and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a crystallized glass material used as a building material, a wall material or the like, and a method for producing the same.

(Prior Art) Conventionally, as a preferable method for producing a crystallized glass material, Japanese Patent Laid-Open No.
As disclosed in JP-A-48-78217, glass powder particles having a specific composition are accumulated in a refractory mold, and each mold is heated to a temperature higher than the glass softening point to soften the glass powder particles and melt them. There is a method of depositing and crystallizing (hereinafter referred to as an integration method).

According to this method, a glass powder for forming a matrix is added with a glass powder for forming a pattern containing an appropriate coloring component, and the powder is accumulated and heat-treated to have an arbitrary color pattern. There is an advantage that a crystallized glass material can be easily obtained.

(Problems to be Solved by the Invention) However, according to the integration method, during heat treatment, the glass powder particles soften and fuse almost at the same time, so that the air present between the powder particles is trapped in the softening fusion object. And remain as bubbles. The smaller the particles of the powder and granule, the larger the amount of the generated air bubbles, and the larger the air bubbles that do not aggregate with each other.

The bubbles and pores in the softened and fused body expand during the heat treatment, which causes blisters and cracks in the crystallized glass material. In addition, since crystallized glass materials are often used as plate materials by smoothing the surface, if glass cells have many air bubbles or pores, the surface after polishing will be dented due to air bubbles or pores. Are exposed, resulting in product defects. Further, the bubbles and pores cannot bear the stress acting on the member, which causes a decrease in strength.

Also, when forming a speckled pattern using colored glass powder particles, it is difficult to form colored spots clearly in the matrix, and when the particle size of the colored glass becomes smaller, the stability of the color deteriorates and the desired color tone is obtained. It is difficult to form a spot pattern. Especially in the case of a black spot pattern, these tendencies are remarkable.

In addition, since the accumulation method softens and crystallizes the aggregate of the glass powder particles, it is necessary to prevent the aggregate from deforming due to the softening of the aggregate during the heat treatment. I have to serve. That is, from the accumulation of the glass powder particles to the completion of the heat treatment, it must be handled in units of molding dies, the handling is complicated, and the productivity is poor. In addition, a large number of expensive heat-resistant molding dies must be prepared, which increases equipment costs.

The present invention has been made in view of the above problems, and a crystallized glass material and a molding die having a black spot pattern which can easily attach a clear black spot pattern and can suppress inclusion of bubbles as much as possible. It is an object of the present invention to provide a method for manufacturing the same glass material that does not require handling for each glass.

(Means for Solving Problems) The crystallized glass material of the present invention made in order to achieve the above-mentioned object is a glass powder having a low softening point and a glass powder having a high softening point, which are softening fusion of the glass powder having a low softening point. later fused integrally, a crystallized glass material obtained by crystallization, wherein the softening point glass powder is a main component by _{weight%, SiO 2: 65~80%,} CaO: 5~10% Na 2 O + K 2 O : 10 to 20%, MgO: 2 to 8%, and the high softening point glass powder is mainly composed of weight% SiO ₂ : 65 to 80%, Al ₂ O ₃ : 25% or less Na ₂ O + K ₂ O: Fe ₃ O ₄ with a grain size of 20 μm or more in the crystallized glass material
It is a constitution of the invention that the powder is dispersed and embedded in a state of being fused with the low softening point glass powder.

Further, as a preferable production method, the main component is by _{weight%, SiO 2: 65~80%,} CaO: 5~10% Na 2 O + K 2 O: 10~20%, MgO: Low is 2% to 8% softening point and the glass powder, SiO main component _{weight% 2: 65~80%, Al 2} O 3: 25% or less Na ₂ O + K ₂ O: glass powder high softening point is 5-15%, the particle size Fe ₃ O over 20 μm
_The mixed powder consisting of ₄ powders is pressure-molded at a temperature not lower than the softening point of the low softening point glass powder and not higher than the crystallization start temperature of the low softening point glass powder to obtain a high softening point glass powder and Fe ₃ O ₄
A glass powder molded body is obtained by softening, adhering or fusing a low softening point glass powder around the powder, and the molded body is a crystallization start temperature of the low softening point glass powder or higher and a high softening point fusible glass powder. The present invention is configured to crystallize by heating to a temperature below the softening point.

(Operation) The crystallized glass material of the present invention is a low-softening point glass powder and a high-softening point glass powder, which are crystallized by softening and fusing the low-softening point glass powder after fusion-melting and fusion. At the time of softening and fusion of the softening point glass powders, the air existing between the powders is discharged to the outside of the powders along the particle surface of the unsoftened high softening point glass powder or Fe ₃ O ₄ powder. Therefore, it is difficult for bubbles to remain in the fused body of both glass powders and Fe ₃ O ₄ powders, and as a result, bubbles and pores have been eliminated as much as possible in the crystallized glass material of the present invention. Will be things.

The low softening point glass powder used in the present invention is a composition of normal soda lime glass, while the high softening point glass powder is
Since it is in the same range as the low softening point glass powder of SiO ₂ content, the low softening point glass softened and fused even at a temperature not lower than the softening point of the low softening point glass powder and lower than the crystallization start temperature of the powder. Diffusion transfer of network-modifying ions such as Na and K from the powder to the high softening point fusible glass powder in an unsoftened state is likely to occur. As a result, the softening temperature is lowered in the component diffusion region of the high softening point glass powder, and the low softening point glass powder and the high softening point glass powder that have been softened and fused are easily fused and integrated.

The reasons for limiting the main components of the low softening point and high softening point glass powders are shown below. The unit is% by weight.

A. Low softening point glass powder SiO _2: SiO ₂ crystal is less than 65% to 80% 65% hardly precipitated, whereas exceeding the softening point is increased to 80%, requires a high temperature heat in the heat treatment, the production is not preferable.

CaO: 5-10% If it is less than 5%, the softening point becomes high, while if it exceeds 10%, it becomes Si.
O ₂ crystals are less likely to precipitate.

Na ₂ O + K ₂ O: 10-20% If the content is less than 10%, the softening point becomes high, while if it exceeds 20%, Si
O ₂ crystals are less likely to precipitate.

MgO: 2 to 8% If less than 2%, the growth of SiO ₂ crystals will be too fast, and crystallization will start before sufficient densification by softening fusion. On the other hand, if it exceeds 8%, it becomes difficult to deposit SiO ₂ crystals.

B. High softening point glass powder SiO _2: SiO ₂ crystal is less than 65% to 80% 65% hardly precipitated, whereas too high a softening point exceeds 80%, hardly causes the diffusion of the components of the low-softening point glass powder Become.

Al ₂ O ₃ : 25% or less Al ₂ O ₃ acts to raise the glass softening point, but 25%
If it exceeds, it becomes difficult to deposit SiO ₂ crystals.

Na ₂ O + K ₂ O: too high softening point is less than 5-15% 5%, diffusion of components of the low-softening point glass powder is less likely to occur.

On the other hand, if it exceeds 15%, the softening point becomes too low, and the softening temperature may become lower than the crystallization start temperature of the low softening point glass powder.

The main components of the low-softening point and high-softening point glass powders are as described above, but in addition, it is permissible to include a colorant and a component usually added in the glass industry field for adjusting physical properties.

In the present invention, a state in which Fe ₃ O ₄ powder having a particle size of 20 μm or more as a black colorant is fused with the low softening point glass powder in the crystallized glass matrix formed by the low softening point and high softening point glass powders It is distributed and embedded in. Below 20 μm,
During crystallization heat treatment at about 900 ° C, it tends to change from 4Fe ₃ O ₄ (black) + O ₂ → 6Fe ₂ O ₃ (red brown), lacking stability in color tone, and making it difficult to see with the naked eye. This is because the glass material becomes monochromatic.

Since Fe ₃ O ₄ powder deteriorates the luster of the crystallized glass material, the content is limited to 20% by weight or less based on the total amount of the mixed powder consisting of the low softening point, high softening point glass powder and Fe ₃ O ₄ powder. It is good to keep it.

Further, according to the production method of the present invention, the mixed powder of the high softening point glass powder, the low softening point glass powder and the Fe ₃ O ₄ powder is the softening point of the low softening point glass powder or less and the low softening point glass powder. Since pressure is applied at a temperature equal to or lower than the crystallization start temperature, the low softening point glass powder is adjacent to the high softening point glass powder,
It is softened and fused, and adheres to high softening point glass powder and Fe ₃ O ₄ powder. At this time, the air existing between the powders is transmitted to the surface of the unsoftened high-softening point glass powder and Fe ₃ O ₄ powder and is discharged to the outside. When the heating temperature is relatively high in the above temperature range, component diffusion and migration occur between the softening fusion-bonded portion of the low softening point glass powder and the high softening point glass powder surface to which the portion adheres, causing component diffusion. The region is softened and the high softening point glass powder and the softening fusion-bonded portion of the low softening point glass powder are fused.

In this way, the mixed powder is adhered or fused and integrated to form a dense glass powder compact. This glass powder compact has a sufficient strength required for handling and can be handled alone.

Next, since the glass powder compact is heated to a temperature not lower than the crystallization start temperature of the low softening point glass powder and not higher than the softening point of the high softening point glass powder, the low softening point glass powder and the high softening point are heated in the temperature rising process. The fusion with the glass powder proceeds, and the softened fusion portion expands. Further, the high softening point glass powder and the Fe ₃ O ₄ powder which are not softened in the inside serve as an aggregate, and the softened and fused portions of the low softening point glass powders are held in a state where the shape of the molded body is maintained. Also, crystals precipitate and grow in the softening fusion-bonded portion in the component diffusion region with the high softening point glass powder. Also,
Also on the surface of the Fe ₃ O ₄ powder particles, the components diffuse with the low-softening point glass powder in the softened state, and fusion occurs.

Therefore, it is not necessary to subject the glass powder molded body to the crystallization heat treatment together with the mold required for the pressure molding of the mixed powder, and the glass powder molded body can be handled alone, and the work is easy and the productivity is excellent. Further, it is not necessary to prepare a large number of expensive heat resistant molds.

(Example) Below, the crystallized glass material of this invention is demonstrated with the manufacturing method.

First, the glass powder used in the present invention will be described.

The main components of the low softening point glass powder and the high softening point glass powder are as described above, but it is desirable to adjust the components of the latter so that the glass softening point thereof is about 800 ° C or higher. This is because the low softening point glass powder has a composition of ordinary soda lime glass and has a softening point of 600 to 750 ° C and a crystallization start temperature of about 800 ° C or less.

The glass powder can be obtained by melting glass having the desired composition, water-crushing it, and further crushing it. As the low softening point glass powder raw material, cullet (scrap glass) of soda-lime glass is used. What is necessary is also to use the high softening point glass powder, which is obtained by crushing perlite (pearlite). Perlite contains Al ₂ O ₃ at 10%
It has a softening point of about 900 ° C or higher, is supplied to the market in large quantities as aggregates, etc., is easily available, and is economical.

It should be noted that naturally occurring perlite has a layered structure, and although it has the same components as those of artificially manufactured glass, the properties are slightly different, but in the present invention, such a glass is included. Perlite contains 3-5% of water between layers, but is dehydrated during heat treatment. In addition, the softening point is higher than that of artificial glass of the same component.

Regarding the particle size of the low softening point and high softening point glass powders, the smaller the particle size and the larger the amount thereof, the easier the softening and fusion of the low softening point glass powders, and the easier the fusion with the high softening point glass powders. As a result, densification and crystallization of the glass powder molded body are promoted. Therefore, it is desirable that the particle size of the glass powder occupy 80% or more (preferably 90% or more) of powder having a mesh size of 200 or less.
Since the Fe ₃ O ₄ powder is added in a small amount, particles having an appropriate particle size may be used depending on the spot pattern, but if the particle size becomes large, the quality deteriorates, so 0.4 mm or less should be used. Preference is given to using.

The low softening point glass powder, the high softening point glass powder and Fe ₃ O ₄
The blending ratio of the low softening point glass powder in the mixed powder with the powder is preferably 20 to 90% by weight. 20
If it is less than%, the softening fusion with the high softening point glass powder or the like is insufficient, and the glass powder compact is insufficiently densified. In addition, the amount of crystals is insufficient and the strength is reduced. On the other hand, if it exceeds 90%, the shape retention of the glass powder compact during heat treatment becomes insufficient, and the function of discharging bubbles from the compact is insufficient. By the way, when the high softening point glass powder is used in a weight part and the low softening point glass powder is used in b weight part, the blending ratio of Fe ₃ O ₄ powder in the mixed powder is (b−a / 4) / 3 weight parts or less. It is good to stop. Here, a / 4 is the minimum amount of the low softening point glass powder necessary for fusing the high softening point glass powder a,
(B-a / 4) is a low-softening point glass powder content can be utilized to fuse the Fe ₃ O ₄ powder, (b-a /
According to the experience of the present inventor, the reason for setting 4) / 3 is that glass powder having a low softening point, which is about three times that of Fe ₃ O ₄ powder, is required to fuse the powder. Therefore, the added amount of Fe ₃ O ₄ powder is (b-
If it exceeds a / 4) / 3 parts by weight, insufficient fusion will occur, which may result in a decrease in strength and an increase in water absorption, which is not preferable.

In addition, the colored glass powder of the same component can be used for a part or all of the low-softening point glass powder and / or the high-softening point glass powder except for the inclusion of the colored portion. By using such a low softening point colored glass powder or a high softening point colored glass powder, or by using a combination of plural kinds thereof, various colored crystallized glass materials having a black spot pattern or colored crystals A glass material can be obtained.

In order to manufacture the crystallized glass material of the present invention, a glass powder compact is first molded with the mixed powder described above.

As a molding method of the glass powder molded body, for example, as shown in FIG. 1, after the mixed powder 2 is put into a molding die 1 (mold), an upper die 3 is fitted and pressure molding is carried out at room temperature ( Normal temperature pressure molding method), the mixed powder 2 is heated and pressed at a temperature not lower than the softening point of the low softening point glass powder and lower than the crystallization start temperature of the powder (hereinafter referred to as densification temperature). There is a method (high temperature pressure molding method). After molding the glass powder compact, it is taken out of the mold and placed in a heat treatment furnace.
It is subjected to a heat treatment described later. Although heat treatment can be performed after molding in the molding die, the handling becomes complicated and the molding die must have good heat resistance.

In the case of the cold-pressing method, the powder is usually pressed to such an extent that the powder particles come into contact with each other (relative density is preferably 50% or more),
Further, in order to secure handling strength (bending strength of 10 Kgf / cm ² or more is desirable) and improve moldability, a few percent of a binder is added to the mixed powder and mixed. If you want to get a large molded body,
The addition of a binder is indispensable to secure the strength. An organic binder such as polyvinyl alcohol (PVA) is usually used as the binder.

The glass powder compact molded at normal temperature is subjected to heat treatment as shown by the solid line in FIG. The section a is a drying section for removing water and organic solvent in the binder.
Section b is a binder removal section, and by maintaining the temperature at 300 to 400 ° C., the polymer component of the binder is decomposed, gasified, and discharged outside the molded body. If the binder remains in the molded body, swelling or cracking occurs in the heat treatment section after the molding, or the physical properties of the product are deteriorated. Therefore, the binder needs to be actively removed. The section c is a densification section, and at the densification temperature (usually 600 to 800 ° C.), the low softening point glass powders are softened and fused, and also adhered or fused to the high softening point glass powder and Fe ₃ O ₄ powder. Further, fusion progresses with further temperature increase. In the same figure, c is shown as a continuous temperature rising state, but after being held at a temperature within a densification temperature range and sufficiently softened and fused,
You may move to the next section. Section d is a crystallization section, which is maintained at a temperature not lower than the crystallization start temperature of the low softening point glass powder and not higher than the softening point of the high softening point glass powder (hereinafter referred to as crystallization temperature, usually 800 to 1000 ° C.). To crystallize the softened and fused portion. It should be noted that crystallization may be performed at a temperature equal to or higher than the softening point of the high softening point glass powder, but in this case, it is necessary to heat treat the glass powder molded body together with the molding die in order to prevent deformation of the shape. Section e is a slow cooling section.

According to the high-temperature pressure molding method, the glass powder in the mold is pressed at the densification temperature, so that the low softening point glass powders are softened and fused together and the high softening point glass powder and Fe are used without using any binder. Relative density of 50% or more, bending strength of 10 Kgf / cm that can be handled independently by being attached or fused to ₃ O ₄ powder
^Two or more glass powder compacts can be easily obtained. In this case, rapid heating to the pressure molding temperature may be performed, and molding time may be very short (about several minutes).

After the pressure molding, the glass powder molded body is taken out of the molding die and immediately charged into the heat treatment furnace. However, when the glass powder molded body is once cooled to room temperature, as shown by the broken line in FIG. The subsequent heat treatment can be performed by rapidly heating to the densification temperature, and the heating in the section a to b, which is required in the normal temperature pressure molding method, can be omitted. Since the section a-b usually takes a long time, the high-temperature pressure molding method is extremely excellent in productivity. For example, in order to obtain a plate-shaped crystallized glass material having a size of 700 cm square and a thickness of 20 to 30 mm, section a to b requires 70 to 80 hours, and even if the glass powder compact is dried in advance before heat treatment. , It takes 40 to 50 hours to remove the binder.

In the high-temperature pressure molding method, the mixed powder can be heat-molded by placing the room-temperature mixed powder in a mold at room temperature, heating the mold to the desired temperature, and then applying a pressure of 5 kgf / cm ² or more. A molding method is generally used. In this case, the heating is usually performed by a heater provided in the molding die or by putting the molding die together in a heating furnace. In addition to this, various heat molding methods can be adopted. For example, a method in which a mixed powder heated to a predetermined temperature is put into a molding die at room temperature and pressure-molded. A mixed powder at room temperature is put into a molding die heated to a predetermined temperature, and the mixture is heated and pressed by the heat held by the molding die. Molding method There is a method in which a mixed powder at room temperature is put in a mold at room temperature and only the surface thereof is heated to a predetermined temperature by electrothermal radiation, infrared radiation, or directly heated by a burner, and pressure molding is performed. Further, it is also possible to heat the mixed powder at room temperature to a predetermined temperature with a pair of hot rolls and to perform pressure molding. Here, the normal temperature includes a state of being preheated at a temperature lower than the softening temperature of the low softening point glass powder.

In order to prevent the low softening point glass powder from sticking, it is desirable that the molding die be subjected to a treatment such as a coating agent such as zircon sand or graphite, a ceramic powder, or a ceramic sheet. .

Next, specific examples will be described.

(1) Various glass powders having the compositions and particle sizes shown in Table 1 were prepared. Incidentally, cullet as a low softening point glass powder raw material,
Perlite was used as the raw material for the high softening point glass powder.

(2) Mix glass powder of Table 1 A and B according to the formulation of Table 2 and mold plate glass powder of 1050 x 1050 mm (thickness 20 to 25 mm) under high temperature pressure molding conditions of the table. Manufactured body. In the table, No. 1 is a comparative example and No. 2 is an example. Also, the average particle size of the Fe ₃ O ₄ powder used was 30 to 7
It was 0 μm.

(3) After high-temperature pressure molding, take out the No. 1 and No. 2 glass powder compacts from the molding die, insert them into a heating furnace kept at 600 ° C, and heat them, then at 30 ° C / Hr at 900 ° C. Up to
After being kept for 4 hours to achieve constant crystallization, it was gradually cooled.

(4) When the bending strength of the obtained crystallized glass material was examined, it was 640 kg / cm ^{2 in} Comparative Example and 630 kg / cm ² in Example,
Both had almost the same strength. Also, both
There were no pores or bubbles observed with the naked eye. FIG. 3 is a structural photograph of the crystallized glass material of the example, and a clear black spot pattern was recognized. In addition, the solar interval at the bottom in the same photograph shows 1 cm.

(Effects of the Invention) As described above, the crystallized glass material of the present invention is crystallized by fusion-bonding the low softening point glass powder and the high softening point glass powder after softening and fusion of the low softening point glass powder. Therefore, the air present between the glass powders during softening and fusion of the low softening point glass powders is discharged to the outside along the surface of the unsoftened high softening point glass powder or Fe ₃ O ₄ powder, You want to have almost no pores or bubbles in the tissue.

Further, the low-softening point and high-softening point glass powders having a specific composition used in the present invention are easily available, and it is easy to secure a difference in softening temperature, and they are easily fused to each other, and are excellent in productivity and economical efficiency. Further, since Fe ₃ O ₄ powder having a predetermined particle size is used, it is possible to disperse and embed a clear black spot pattern in the crystallized glass matrix without being discolored by the crystallization heat treatment.

On the other hand, according to the production method of the present invention, it is possible to easily obtain a glass powder compact having a high strength that can be handled alone without using any binder, so that it is necessary to remove the heat treatment for a long time. Binder is not required and productivity is extremely excellent. Moreover, since crystallization of the glass powder compact is performed at a temperature equal to or lower than the softening point of the high softening point glass powder, the inside of the unsoftened high softening point glass powder and Fe ₃ O ₄ powder function as an aggregate, and the high temperature crystal The shape of the molded body is maintained even during the chemical heat treatment, and the shape of the molded body does not collapse. For this reason,
There is no need to heat-treat each mold, improving productivity,
The equipment cost can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a molding die showing a molding procedure of a glass powder compact, FIG. 2 is a heat treatment diagram showing an example of heat treatment of a crystallized glass material of the present invention, and FIG. FIG. 3 is a photograph of the structure of a crystallized glass material with a black speckled pattern of Example.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hiroyuki Kimura 64, Nishimukaishima-cho, Amagasaki City, Hyogo Prefecture Kubota Iron Works Co., Ltd. Amagasaki Plant (72) Kei Shikata, 64, Nishimukaijima-cho, Amagasaki City, Hyogo Prefecture Kubota Iron Works Co., Ltd. Amagasaki Plant (56) References JP-A-63-17238 (JP, A) JP-A-48-78217 (JP, A)

Claims (2)

[Claims] 1. A low softening point glass powder and a high softening point glass powder are fused and integrated after softening and fusion of the low softening point glass powder,
A crystallized glass material obtained by crystallization, wherein the low-softening point glass powder is a main component by _{weight%, SiO 2: 65~80%,} CaO: 5~10% Na 2 O + K 2 O: 10~20% , MgO: 2 to 8%, and the high softening point glass powder is mainly composed of weight% SiO ₂ : 65 to 80%, Al ₂ O ₃ : 25% or less Na ₂ O + K ₂ O: 5 to 15%. Yes, Fe ₃ O ₄ with a grain size of 20 μm or more in the crystallized glass material
A crystallized glass material having a black speckled pattern, characterized in that the powder is dispersed and embedded in a state of being fused with a low softening point glass powder. 2. A main component in _{weight%, SiO 2: 65~80%,} CaO: 5~10% Na 2 O + K 2 O: 10~20%, MgO: low softening point glass powder is 2% to 8% If, SiO main component in _{weight% 2: 65~80%, Al 2} O 3: 25% or less Na ₂ O + K ₂ O: and the high-softening point glass powder is 5-15%, particle size of more than 20 [mu] m Fe ₃ O
_The mixed powder consisting of ₄ powders is pressure-molded at a temperature not lower than the softening point of the low softening point glass powder and not higher than the crystallization start temperature of the low softening point glass powder to obtain a high softening point glass powder and Fe ₃ O ₄
A glass powder molded body is obtained by softening, adhering or fusing a low softening point glass powder around the powder, and the molded body is a crystallization start temperature of the low softening point glass powder or higher and a high softening point fusible glass powder. A method for producing a crystallized glass material having a black speckled pattern, which comprises heating to a temperature equal to or lower than a softening point to crystallize.