JPH0449498B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a natural stone-like crystallized glass article suitable for use in architecture such as the interior or exterior walls of buildings, or for decoration of interiors and the like. [Prior Art] The composition systems and compositions of natural stone-like crystallized glass articles that have been proposed so far are quite wide, and the crystals thereof are also various. Specific examples include Special Publication No. 47-2276 and Publication No. 51-23966.
JP-A-56-104747, JP-A-59-92942,
Forsterite-based and forsterite-gahnite-based crystallized glass as typified by JP-A No. 60-27622, and crystallized glass containing a large amount of Fe ₂ O ₃ as typified by JP-B No. 49-36376. , and furthermore, Special Publication No. 14839 of 1983, Publication of Special Publication No. 14839 of 1973-
41693, Japanese Patent Publication No. 57-20254, etc. have been proposed. Although there are some slight differences in the manufacturing methods of the crystallized glass products proposed in these proposals, all of them are made by heat treating crystalline glass within a predetermined composition range. Precipitate crystals
It is common to ultimately obtain crystallized glass articles by growing them, and these crystallized glass articles are grown in a given physical and chemical manner for the purpose of use as architectural and decorative materials. It is considered to have natural stone-like properties and a beautiful appearance similar to natural stone. [Problems to be Solved by the Invention] By the way, the present inventor has repeatedly conducted various research and development on the production of crystallized glass articles exhibiting the appearance of natural stone as described above, and has found that the above-mentioned β-wollastonite etc. It has become clear that it is possible to obtain a new crystallized glass article that has a natural stone-like appearance and is derived from a crystal different from that of the present invention. The provision of such a novel crystallized glass article is
It is preferable in that it expands the range of choices for articles of this type used for various purposes, and in particular, it expands the scope for selecting not only the characteristic decorative appearance of such articles, but also the physical properties of various articles. It is. [Object of the Invention] The present invention provides novel anorthite and gehlenite crystals that have sufficient physical properties to be used, for example, as architectural and decorative materials, and also exhibit a beautiful natural stone-like appearance. The purpose is to provide fused glass products. [Means for Solving the Problems] The crystallized glass article according to the present invention, which was made to achieve the above object, is characterized by being a crystallized glass article in which crystals are precipitated and grown by heat treatment. Therefore, the glass composition before crystal precipitation is
_SiO2 32.0~42.0%, _{Al2O3 21.5} ~30.5%, CaO23.0
~32.5%, ZnO5.0 _~ 10.5%, _B2O30 ~4.5%, _K2
Crystals containing 0 to 1.5% O, 0 to 3.5% _Na2O , and 0 to 6.0% _TiO2 , in which the total amount of each of these components is 95% or more of the total, and which is finally obtained by heat treatment. The precipitated crystals of acicular anorthite (CaO・Al ₂ O ₃・2SiO ₂ ) and dendritic gehlenite (2CaO・Al ₂ O ₃・SiO ₂ ) are arranged in an orderly manner from the surface toward the inside of the ceramic glass article. As these crystals grow and mix with the glass matrix phase, they exhibit a beautiful natural stone-like appearance. In the crystallized glass article according to the present invention, the glass composition before crystal precipitation is its basic three components.
The proportion of SiO ₂・Al ₂ O ₃・CaO has been specified so as to remain within the composition range where anorthite is the primary crystal. The coefficient of thermal expansion of gehlenite, which can be expected to precipitate at this time, is approximately 80 to 85 x 10 ^-7 /°C, which is ^higher than that of the known crystallized glass articles. Thermal expansion coefficient of the main crystal (e.g. β-wollastonite approximately 95-100×
10 ^-7 /℃, deopside about 75 to 85 × 10 ^-7 /℃,
Forsterite approx. 95×10 ^-7 /℃, Nepheline approx.
100～130× ^10-7 /℃, Okermanite approx. 100～
105× ^10-7 /℃, Garnite approx. 80-84× ^10-7 /℃)
This is because it was thought that a crystallized glass article with sufficient physical properties to be used as an architectural and decorative material could be obtained because it is the same or even smaller than the above. Furthermore, the reason why the glass composition forming the crystallized glass article of the present invention was specified as described above is as follows. When SiO ₂ is less than 32.0%, it becomes difficult to vitrify, and at the same time, the structural skeleton of the glass becomes weak, making it impossible to obtain the desired physical properties. Moreover, if it exceeds 42.0%, the rate of crystal precipitation and growth becomes slow, making it difficult to precipitate sufficient crystals. _{Al2O3 is}
If it is less than 21.5%, the crystal precipitation/growth rate becomes slow, making it difficult to precipitate sufficient crystals, and at the same time, microcracks are likely to occur in the crystallized glass article obtained by heat treatment. If it exceeds 30.5%, the viscosity of the glass increases, making it difficult to mold, and at the same time, the rate of crystal precipitation and growth becomes slow, making it difficult to precipitate sufficient crystals. When CaO is in a range other than 23.0 to 32.5%, fine cracks and pores are likely to occur in the crystallized glass article obtained by heat treatment. ZnO is an essential component as a crystal precipitation/growth accelerator, and if it is less than 5.0%, the crystal precipitation/growth rate will be slow, making it difficult to precipitate sufficient crystals, while if it is more than 10.5%, crystal precipitation/growth will occur. The speed is too fast, causing melting and
Devtrification is likely to occur during molding. Next, the subcomponents contained together with the four main components will be explained. B ₂ O ₃ is preferably added as an effective component for lowering the melting temperature and lowering the viscosity, but on the other hand, it is preferably kept at 4.5% or less because it slows down the rate of crystal precipitation and growth. K ₂ O is an effective component that has the effect of improving formability and slowing down the crystal precipitation/growth rate, and it is preferable to finely control the crystal precipitation/growth rate by adding a small amount. % or more, it becomes difficult to precipitate sufficient crystals. _Na2O
is an effective component for lowering the melting temperature, reducing viscosity, and improving formability, but if it exceeds 3.5%, fine cracks are likely to occur in the crystallized glass article obtained by heat treatment. TiO ₂ is an effective component for suppressing devitrification, but if the content is too high, it will exhibit an unfavorable grayish color tone, so it is desirable to keep it at 6.0% or less. The total amount of the above-mentioned main components and subcomponents of the present invention is required to be 95% or more of the total glass composition, and the remainder includes impurities and appropriate fining agents commonly used in the production of glass articles. Common glass compositions such as colorants can be added as necessary. For example, effective components for lowering the melting temperature and viscosity include Li ₂ O 0-1.5%, BaO 0-5.0%, MgO 0-3.0%, and PbO 0-5.0%, which are divalent oxides similar to CaO, or There is no inconvenience in adding 0-1.0% of known clarifiers such as As ₂ O ₃ , Sb ₂ O ₃ , CeO ₂ and effective amounts of known coloring agents such as CoO, CuO, NiO, Fe ₂ O ₃ It does not cause The production of the crystallized glass article according to the present invention generally involves melting the raw materials prepared to have the composition range described above, melting the glass, and then melting the glass using a roll-out method, a press method, or the like.
After molding into a desired shape such as a plate or tile using a conventional molding method such as the pouring method, it is placed in a crystallization furnace and heated at a rate of 150 to 300 °C/h to 1000 °C.
Heat treatment is performed by holding at ~1200℃ for 3 to 6 hours,
This is done by precipitating and growing acicular anorthite and dendritic gehlenite from the surface of the crystalline glass molded product. The crystallized glass article according to the present invention can be easily manufactured by the simple one-step heat treatment after forming as described above, or by cracking at least the surface or the vicinity of the crystallized glass article before heat treatment, and then heat treatment. It is also possible to apply a method in which small pieces of crystalline glass, crystallized glass, or amorphous glass are dispersed in a crystalline glass melt and then heat-treated (so-called dispersion method). It is possible to have characteristics depending on each manufacturing method. The decorative, natural stone-like aesthetic appearance exhibited by the crystallized glass article of the present invention is achieved by melting and forming glass using raw materials within the above-mentioned predetermined composition range.
Obtained by heat treatment. There are two types of crystals that precipitate and grow during heat treatment: acicular anorthite and dendritic gehlenite, and these two types of crystals have different crystal shapes. Due to this growth and the coexistence of these two types of crystal phases with the glass matrix phase, the obtained crystallized glass article exhibits a beautiful appearance similar to natural stone. It goes without saying that by appropriately changing heat treatment conditions such as heat treatment temperature and heat treatment time as necessary, the crystallization rate and appearance can be varied within a certain range. [Embodiments of the Invention] Examples of the present invention will be described below. Silica powder, aluminum hydroxide, calcium carbonate, zinc oxide, calcium borate, potassium carbonate,
Potassium nitrate, sodium carbonate, sodium nitrate, titanium oxide, lithium carbonate, barium carbonate,
No. 1 in Table 1 using magnesium hydroxide, red lead, arsenous acid, antimony oxide, and cerium oxide as raw materials
After preparing batches satisfying the composition of No. 13, each batch was placed in a platinum crucible and melted in an electric furnace at a temperature of 1450°C for 6 hours.

【table】

〔Effect of the invention〕

The crystallized glass article obtained by the present invention exhibits an excellent aesthetic appearance resembling a natural stone as a novel product having unprecedented CaO-Al ₂ O ₃ -SiO ₂ -based anorthite crystals and gehlenite crystals, and also exhibits excellent physical properties. It also shows excellent properties that can be put to practical use as building materials or decorative materials, and its usefulness is great.

Claims (1)

[Claims] 1 A crystallized glass article in which crystals are precipitated and grown by heat treatment, and the glass composition before crystal precipitation is SiO ₂ 32.0 to 42.0% and Al ₂ O ₃ 21.5 to 30.5% by weight.
%, CaO23.0-32.5%, _ZnO5.0-10.5 %, _B2O30
~4.5%, _K2O0 ~1.5%, _Na2O0 ~3.5%, _TiO20
6.0%, the total amount of each of these components is 95% or more of the total, and the natural stone-like crystallized glass article is characterized by having anorthite and gehlenite crystals.