JPH0416421B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention relates to a method for manufacturing crystallized glass having a color pattern. <Conventional technology> Conventional crystallized glass is generally manufactured by melting a glass raw material containing a nucleating agent, shaping it by various means, and then subjecting it to crystallization heat treatment to precipitate crystals. It shows. Colored crystallized glass can be produced by adding a coloring agent to the above raw materials. Another method for obtaining crystallized glass is to crush molten glass by water cooling, etc. to form glass bodies, and then accumulate the glass bodies in a mold and heat treat them to fuse and integrate each glass body. The crystallization method (hereinafter referred to as the accumulation method) was developed in ``Japanese Patent Application Laid-Open No. 1973-
78217, and the crystallized glass produced by this method is white with patterns due to non-uniform crystal growth, and colored crystals are produced by using glass containing a colorant in the glass bodies of the raw material. It can be made of glass. <Problems to be solved by the invention> In general, glass is a material that has problems with its strength, and improvements in its strength are always sought after.Also, the diversification of decorative materials, construction materials, etc. has led to the need for uniform coloring even in colored glass. It is expected that a glass with a change in shape, for example a glass with a mottled pattern, will appear.From this perspective, it is possible to melt and shape the glass raw material containing the nucleating agent and the glass coloring agent, and then heat-process it for crystallization. The problem with this method of producing crystallized glass is that it requires uniform coloring and that the nucleating agent may be more expensive than the raw materials. In the case of the following accumulation method, patterns are created by the non-uniform growth of crystals as mentioned above.If the accumulation is carried out by heating the glass bodies, each glass body is heated at the temperature at which the crystals precipitate. It is not suitable unless it has a sufficiently low viscosity that it can fuse and integrate with each other. As such, there are limitations on the raw material glass, and therefore glass bodies containing a nucleating agent or a coloring agent that acts as a nucleating agent, such as FeS+MnS, FeO+Fe ₂ O ₃ , etc., cannot be used. In other words, when the generation and growth of crystal nuclei occurs at relatively low temperatures, many crystals have already grown by the time the glass bodies soften and fuse, which increases their viscosity and prevents them from being integrated. If an attempt is made to further increase the temperature to achieve integration, the crystals will instead break or transform and will not become crystallized glass. In addition, this accumulation method has the problem that the color does not come out clearly even if the raw material uses a coloring agent that does not act as a nucleating agent, and that the product contains relatively large bubbles (about 0.5 mm in diameter). It also has its problems. <Means for solving the problems> The present invention solves the above problems and makes it possible to provide a crystallized glass with a mottled color pattern. _SiO2 : 40 _~ 50%, _Al2O3 : 5~
20%, CaO: 30~40%, colorant: 0.5 _{~ 15} % as essential components, and 10 mesh or less and ₁₀ ~ Powder in which 200mesh particles account for ₂₀ % or more, _SiO2 : 55-75%, _Al2O3 : 15% or less,
CaO: 5-15%, Na ₂ O + K ₂ O: 10-20% as essential components, and SiO ₂ + Al ₂ O ₃ + CaO + Na ₂ A +
A powder made by pulverizing a glassy raw material containing K ₂ O > 90%, in which 90% or more of the particles are 200 mesh or less, is mixed, and the mixed powder is compressed or vibrated to 50% of its true density. After the above-mentioned molded body was formed, it was heat-treated to soften and fuse the particles constituting the molded body to integrate and densify it, while crystallizing it so that mainly wollastonite crystals were precipitated. <Example> In other words, the above-mentioned means heat-treats a mixture of powders of a colored glassy raw material (hereinafter referred to as colored raw material) and a colorless glassy raw material (hereinafter referred to as colorless raw material) to fuse and integrate them. This is a method for crystallization, and has the following three points. The composition of the colored and colorless raw materials should be such that the colored raw materials have a higher softening point than the colorless raw materials (the difference is preferably 400°C or less), and when both raw materials are fused and integrated, the softening point is better than when each raw material is used alone. The composition should be such that it is easy to crystallize. In other words, from the viewpoint of composition, crystallization proceeds after the colored and colorless raw material powders are fused and integrated. By molding a mixture of colored and colorless raw material powders into a dense molded body of fine powder and heat-treating it, it is possible to fuse and integrate the powder particles and make them denser at low temperatures. Conventional stacking methods simply heat the glass bodies of the stack, and do not easily integrate even when the glass bodies reach their softening point. First, the glass corpuscles begin to soften from the sharp corners, and in order for most of the glass corpuscles to soften and to essentially fuse and integrate, the glass corpuscles must be heated to a considerably high temperature above the softening point due to the relationship between the gaps between the corpuscles. It must be heated to . If it is attempted to fuse and integrate the materials at a low temperature slightly above the softening point, it will take a very long time or is difficult to achieve. However, as mentioned above, in a dense compact of fine powder, each powder particle is in close contact over a large area compared to its mass, and each particle that reaches the softening point easily softens, and the fusion and integration also soften. This occurs at a low temperature not much higher than the point, and densification easily progresses. In other words, from the aspect of particles, it is possible to perform integral densification before crystallization. By making the particle size of the colored raw material powder coarser than that of the colorless raw material powder, a mottled pattern appears. If both the colored and colorless raw materials are made into fine powders of 200 mesh or less, the mixture of the two forms a uniform color base, and there is no point in adjusting the colored and colorless raw material powders separately. The reasons for limiting the ingredients will be explained in detail below. First, the main components of colored and colorless raw materials are shown in Table 1 below.

[Table] Among the above compositions, the notable difference except for the colorant is CaO.
and _Na2A + _K2O . In other words, colorless raw material
CaO is increased in the colored raw material instead of Na ₂ A + K ₂ O, and this causes the colored raw material to exhibit a higher softening point than the colorless raw material. In addition, in a mixed molded product of colored and colorless raw material powders, there are not only parts where the two are in contact with each other, but also parts where colored particles are together and colorless particles are together, and the composition thereof is particularly when the two are fused and integrated. In addition to taking into account the physical properties of each part mentioned above, the shape retention of the dense molded product during heat treatment, and the effect on integral densification, etc., the reason for the limitation on colorless raw materials is as follows: ₂ : 55-75% _SiO2 is a component that forms the skeleton of glass,
Since the colorless raw material constitutes the base of the crystallized glass according to the present invention, the lower limit was set at 55%. or
If it exceeds 75%, the viscosity of the glass increases and the fusion and densification of particles becomes slow. Al ₂ O ₃ : 15% or less Al ₂ O ₃ is a component that has the effect of raising the softening point, and in order to suppress the softening point to a lower level than the colored raw material, it needs to be 15% or less. CaO: 5-15% If it is less than 5%, it becomes difficult to precipitate crystals such as wollastonite and anorsite. Moreover, when it is 15% or more, the softening point increases and crystallization of the colorless raw material alone becomes easy. That is, before the colored and colorless raw material powders are densified together, the crystallization of the colorless raw material may increase the viscosity. Na ₂ O + K ₂ O: 10 to 20% 10% is necessary in order to have a softening point lower than that of the colored raw material, and if it exceeds 20%, it becomes difficult to maintain the shape of the molded product during heat treatment. The reason why the total of the above essential components is 90% or more is to maintain the appropriate physical properties of the product. Next, we will discuss limiting the components of colored raw materials. SiO ₂ : 40-50% If it is less than 40%, it is difficult to maintain the shape of the molded product during heat treatment, while if it is more than 50%, the viscosity of the glass increases due to the content of other components and dust, and the particles become fused and densified. Become slow. Al ₂ O ₃ : 5 to 20% At least 5% is necessary to maintain a high softening point, but if it exceeds 20%, the viscosity of the glass increases and the fusion and densification of particles becomes slow. CaO: 30-40% At least 30% is necessary to have a higher softening point than the colorless raw material, but if it exceeds 40%, physical properties such as water resistance and acid resistance will deteriorate. Colorant: 0.5-15% Colorants include CoO, FeS+MnS, FeO+
Fe ₂ O ₃ , Cr ₂ O ₃ , NiO, CuO, MnO ₂ etc.
At least 0.5% is necessary for coloring effect, but
If it exceeds 15%, it will adversely affect the physical properties of the glass. In addition, the total amount of other essential ingredients excluding the above coloring agent is
The reason why it is limited to 85% or more is because, as mentioned above, if the colorant and non-essential components exceed 15%, physical properties will be adversely affected. Next, the particle size of the raw material powder and dense compaction will be described. Colorless and colored raw materials are obtained by adjusting and melting the raw materials for each of the above-mentioned components so as to have a predetermined composition, and then rapidly cooling and crushing this by a method such as water pulverization to form glass-like particles. Of course, a material having a specific range of component composition and already in the form of glass may be crushed by an appropriate means to form small bodies. The glass bodies thus obtained are further pulverized using, for example, a ball mill, and at this time the colorless raw material is made into fine particles of 200 mesh or less.
However, there is no problem even if it contains less than 10% of 200mesh or more. The colored raw material should be a powder of 10 mesh or less, with 10 to 200 mesh powder accounting for 20% or more. The presence of particles coarser than 10mesh tends to cause air bubbles inside the product, leading to a decrease in strength.
The reason why we always make sure to include particles of 10 to 200 mesh is to create a mottled pattern, as mentioned above.
The reason why the content of the same particles is limited to 20% or more is because if the content is less than 20%, the distribution of the mottled pattern will become too sparse in products made by mixing and sintering colored and colorless raw material powders, and there will be no actual appearance of mottled patterns. . The thus obtained colorless and colored raw material powders are mixed and then placed in a molding frame and molded by pressure or vibration molding. In this case, a dense compact containing a large amount of fine powder of 200 mesh or less will facilitate the fusion and integration of powder particles at low temperatures and densification, but in order to make many mottled patterns appear, ~
It is necessary to increase the number of 200mesh colored raw material particles.
Therefore, it is necessary to balance the particle size, but in the present invention, consideration has been given to the composition of the colored and colorless raw material powders so that crystallization will be easy after they are fused and integrated, so the particle size should be 200 mesh or less. If about 50% of the particles are contained, fusion and integration and densification can be performed at low temperatures, and crystallization can be performed by raising the temperature thereafter. There is also a limitation that the density of the compact is 50% or more of the true density.
This is to ensure the integral densification of particles at low temperatures and to suppress the amount of shrinkage of the compact during sintering. When molding a dense compact with a true density of 50% or more, pressurize the mixed powder by placing it in a compression molding frame. A suitable pressure is 20 kgf/cm ² or more. When using vibration molding, place it in a vibration molding frame for 30~
Dense packing is performed by applying 180Hz vibration. this is
This is because the dense packing effect is small below 30 Hz, and the effect of separating fine and coarse particles appears above 180 Hz. Furthermore, as described below, when a binder is used, there is an effect that water added for kneading is appropriately floated on the molded body at the above-mentioned vibration frequency and separated. Note that vibration molding is an advantageous molding method even when the molding frame becomes large, that is, even when the molded product becomes large, especially in that it is necessary to use a large vibrating device. When mixing glassy raw material powders, it is effective to add a small amount of a binder such as a polyvinyl alcohol (PVA) solution to facilitate molding. Appropriate selection of the binder not only makes molding easier, but also prevents damage to the dense molded body (shiraji) during transportation and gives the shiraji the strength to withstand shrinkage during sintering. can do. For example, montmorillonite binder (mainly composed of montmorillonite, _SiO2 : 60-80%,
Al ₂ O ₃ : 5-20%) and alumina cement binder (Al ₂ O ₃ : 45-80%, CaO: 18-40%,
A good example of this is SiO ₂ (containing 1 to 5%), and the amount added depends on the strength required by Shiraji, that is, the strength it needs to have in order to prevent damage during transportation and withstand shrinkage during sintering. 7Kg which is set as
An appropriate amount is such that a bending strength of f/cm ² or more can be obtained and that does not substantially affect the component system of the glass. Specifically, for both the montmorillonite type and the alumina cement type, it is sufficient to add up to 5% by weight, and for the montmorillonite type, it may be partially replaced with PVA, such as 2% montmorillonite + 3% P.VA or less. Such a binder is added to a mixed powder of glassy raw materials together with an appropriate amount of water, and after being thoroughly kneaded, it is compressed or vibration-molded using a molding frame as described above to reduce the true density to 50% of the true density. The above dense molded body is obtained. As shown in the heat treatment curve of FIG. 1, the heat treatment of the dense compact obtained as described above includes low temperature treatment (first stage treatment section a-a) for integral densification of particles, followed by A high-temperature treatment (second stage treatment section b-b) for crystallization is performed. Figure 2 shows the "crystal growth rate-temperature" curve in heating a dense compact, where SP is the softening point and MP is the melting point. be. In this low-temperature treatment, the unification and densification of particles mainly occur through softening and fusion of the colorless raw material powder, and the processing temperature is low, and in addition, the composition of each individual raw material powder is of a type that suppresses crystallization. Even if a nucleating agent is included in the component, it does not cause the same disadvantages as in the accumulation method, but rather facilitates crystallization in the subsequent heat treatment. After the first-stage low-temperature treatment, the temperature is raised to a temperature range in which the crystal growth rate increases as shown in FIG. 2, and a second-stage high-temperature treatment is performed. At this point, the integral densification of colorless and colored raw material particles and the integral densification of colored raw material particles have already progressed, and crystallization has also taken place, but especially at the fused interface of colorless and colored raw material particles,
As the two are integrated, the composition becomes easy to crystallize, so crystal precipitation and growth are active. Note that if the heat treatment temperature is set too high, it will be difficult to maintain the shape of the molded product, so care must be taken. The colored patterned crystallized glass obtained in the above manner has a distributed colored mottled pattern, and the mottled pattern may be a fine spotted pattern or a blocky mottled pattern depending on the particle size, amount, mixing ratio, etc. of the colored raw material particles. The shape of the pattern, the density of the distribution, the density of the mottled pattern, etc. can be varied in various ways. The base part made of colorless raw materials becomes white due to crystallization during heat treatment, but it can also be made to look like a colored base by adjusting and mixing fine particles of 200 mesh or less of colored raw materials, and further using colored raw material powders of multiple colors. By doing so, it is also possible to give a color change to the mottled pattern. Next, specific examples of the present invention will be shown. The colored and colorless raw materials used in the examples had the compositions shown in Table 2.The raw materials containing each component were melted at 1500°C, and then poured into water to form colored and colorless raw materials, respectively. vitreous bodies were obtained. Colored raw materials are 1500 as mentioned above.
Because it is melted and granulated at ℃, the FeO/Fe ₂ O ₃ ratio is high, and the granulated raw material has a black color. (FeO+
Fe ₂ O ₃ is a coloring agent and also acts as a nucleating agent).

[Table] The glass corpuscles were crushed by a ball mill,
A powder having the following particle size was obtained by sieving. Colored raw material powder: 10 to 200 mesh Colorless raw material powder: 200 mesh or less The above raw material powders were mixed at a ratio of 1:1 to form various dense compacts as shown below. The dimensions of each dense molded body are 100 x 100 x 25 (mm)
It is. A small amount of PVA as a binder in the above raw material powder
After adding the solution and thoroughly kneading, pressure molding was performed at a pressure of 30 Kgf/cm ² . 3% of a montmorillonite binder was added as a binder to the raw material powder, together with 15% of water, and after thorough kneading, pressure molding was performed at a pressure of 30 Kgf/cm ² . The bending strength of Shiraji is 10Kgf/cm ²
It was hot. A 3% alumina cement binder was added as a binder to the raw material powder, together with 15% water, and after thorough kneading, pressure molding was performed at a pressure of 30 Kgf/cm ² . The bending strength of Shiraji is 11Kgf/cm ²
It was hot. 3% of a montmorillonite-based binder was added as a binder to the raw material powder, together with 15% of water, and after thorough kneading, vibration molding was performed by applying vibrations of 60 Hz. The bending strength of the plain ground was 11 kgf/cm ² . The above heat treatment of Shiraji was done at 150℃/h.
When the temperature was raised to 750°C at a heating rate of 200°C, held at the same temperature for 30 minutes, and then held at 900°C for 3 hours, wollastonite crystals were precipitated. The bending strength of each product was 630 Kgf/cm ² . FIG. 3 is a heat treatment curve for the above example. Note that when the holding time at 900°C is prolonged in the above heat treatment, FeO changes to Fe ₂ O ₃ , so the color tone gradually becomes yellowish. FIG. 4 is a diagram showing the pattern state of the colored patterned crystallized glass of the above-mentioned example, and ~
The case was almost the same. <Effects of the Invention> As described above, the method of the present invention not only adjusts the component composition of colored and colorless raw materials, but also refines the glassy raw material and makes it into a dense compact, thereby achieving integral densification of powder particles. Therefore, glass with a wide range of compositions can be easily crystallized without the problem of increased viscosity caused by crystal growth as in the case of the integrated method, and the colored pattern can also be made from colored and colorless glass powder. As mentioned above, it is possible to create extremely varied patterns as described above. In addition, since the powder is molded into a mold, it can be easily formed into a desired shape, and it is also easy to create irregularities on the surface. In addition, by using an appropriate binder, the strength of the base can be increased, handling becomes easier, and economical efficiency can be improved. Furthermore, it is a method that does not contain large air bubbles inside the product, which is a great advantage in terms of strength. The industrial value of the present invention, which has many advantages as described above and can provide colored patterned crystallized glass as an excellent decorative material and building material, is enormous.

[Brief explanation of drawings]

FIG. 1 is a heat treatment curve of a dense compact of glassy raw material powder according to the present invention, FIG. 2 is a crystal growth rate-temperature curve during heating of the dense compact, and FIG. 3 is a heat treatment curve of an example of the present invention. FIG. 4 is a diagram showing the pattern state of the colored patterned crystallized glass according to the embodiment of the present invention.

Claims (1)

[Claims] 1 Weight percentage: SiO ₂ : 40-50%, Al ₂ O ₃ : 5
~20%, CaO: 30-40%, colorant: 0.5-15% as essential components, and SiO ₂ + Al ₂ O ₃ + CaO > 85%
10mesh made by crushing glassy raw material containing
Powder with the following and 10 to 200 mesh particles occupying 20% or more, SiO ₂ : 55 to 75%, Al ₂ O ₃ : 15% or less,
CaO: 5 to 15%, Na ₂ O + K ₂ O: 10 to 20% as essential components, and SiO ₂ + Al ₂ O ₃ + CaO + Na ₂ O +
A powder made by pulverizing a glassy raw material containing K ₂ O > 90%, in which 90% or more of the particles are 200 mesh or less, is mixed, and the mixed powder is compressed or vibrated to 50% of its true density. A color pattern characterized by the above molded body being heat-treated to soften and fuse the particles constituting the molded body to integrate and densify it, while crystallizing it to precipitate mainly wollastonite crystals. A method for producing crystallized glass.