JPS6287435A - Crystallized glass articles like naturally occurring rock - Google Patents

Abstract

PURPOSE:A specifically composed glass containing SiO2, Al2O3, CaO, ZnO, B2O3, K2O, Na2O and TiO2 is allowed to crystallize out and grow by heat treatment to produce crystallized glass articles similar to naturally occurring rocks which are suitable for building construction and ornamental purposes. CONSTITUTION:A glass which is composed of 32.0-42.0wt% of SiO2, 21.5-30.5wt% of Al2O3, 23.0-32.5wt% of CaO, 5.0-10.5wt% of ZnO, 0-4.5wt% of B2O3, 0-1.5wt% of K2O, 0-3.5wt% of Na2O and 0-6.0wt% of TiO2 and totalling over 95% is heat-treated to effect the crystallization out and crystal growth. Thus, crystallized glass articles which have beautiful appearance like naturally occurring needle anorthite and branched gehlenite are obtained.

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 interior and exterior walls of buildings, or for decoration of interiors and the like.

[Conventional technology]

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. To give a specific example, Tokuko Sho 47-2
JP-A No. 56-10474 of books containing β-wollastonite as the main crystal, such as JP-B No. 276, JP-B No. 51-23966, and JP-B No. 39884-Sho 53.
Publication No. 7, JP-A-59-92942, JP-A-60
-Forsterite-based and forsterite-gahnite-based crystallized glasses, as typified by Publication No. 27622, etc.
F.
Crystallized glass containing a large amount of 205, and also
-14839 Publication, Special Publication No. 53-41693,
Japanese Patent Publication No. 57-20254 and the like 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. It is common to precipitate and grow crystals to ultimately obtain crystallized glass articles, and these crystallized glass articles can be used in a given physical manner for use as architectural and decorative materials.・In addition to having chemical properties, it is also considered to have a beautiful appearance similar to natural stone.

[Problem that the invention seeks to solve]

By the way, as a result of various research and development conducted by the present inventor regarding the production of crystallized glass articles exhibiting the appearance of natural stone as described above, it was found that natural stone derived from a crystal different from the crystals such as β-wollastonite mentioned above. It has become clear that a new crystallized glass article having a similar appearance can be obtained.

The provision of such novel crystallized glass articles expands the selection of articles of this type for a variety of applications, particularly the selection of distinctive decorative appearances such articles exhibit, as well as the variety of articles. This is preferable in that it expands the range of physical properties that can be selected.

[Purpose of the invention]

The present invention provides a crystallized glass article having novel anorthite and gehlenite crystals, which has sufficient physical properties to be used as, for example, architectural and decorative materials, and also exhibits a beautiful natural stone-like appearance. The purpose is to

[Means for solving problems]

Therefore, the characteristics of the crystallized glass article according to the present invention, which has been made to achieve the above object, are crystallized glass articles in which crystals are precipitated and grown by heat treatment, and the glass composition before crystal precipitation is 5SO232, O ~ 42.0%,
At20321.5-30.5%.

Ca023. O~32.5%, ZnO5.0~10.
5% *B20SO~4.5%, K2O0~1.5
%, Na2O0~3.5%, Tie20~6
．． 0%, and the total amount of each of these components is 9% of the total.
5% or more, and the crystallized glass article finally obtained by heat treatment has acicular anodes that are precipitated crystals.
rhinoceros) (CaO・At20.-28102) and dendritic oy-tz night (2C&0・A/!, 20.・81
0□) grow in an orderly manner from the surface toward the inside, and when these crystals are mixed with the glass matrix phase, it exhibits a beautiful natural stone-like appearance.

In the crystallized glass article according to the present invention, the glass composition before crystal precipitation consists of three basic components: SiO□lAZ
The ratio of 205 r CaO is specified to remain within the composition range in which anorthite is the primary crystal, and the reason for this is that the thermal expansion coefficient of anorthite crystals is approximately 45 to
It exhibits low expansion at 107°C, and the coefficient of thermal expansion of Dalenite that can be expected to precipitate at this time is about 80~
The thermal expansion coefficient of the main crystal of the lath article (for example, β-wollastonite is about 95-100X10/℃, dioside is about 75-85
To X10-.

forsterite approx. 95X10/℃, nepheline approx. 100-130X10/℃, ocher night approx. 1
00~105X10/℃, Garnite approx. 80~84
This is because it was thought that a crystallized glass article having sufficient physical properties to be used as an architectural and decorative material could be obtained because it is equivalent to or even smaller than the average temperature (x10-'/°C).

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 S io2 is less than 32.0%, vitrification becomes difficult and the structural skeleton of the glass becomes weak, making it impossible to obtain desired physical property values. Moreover, if it is 42.01 or more, the crystal precipitation/growth rate becomes slow, making it difficult to precipitate sufficient crystals. At20. 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, the crystallized glass article obtained by heat treatment tends to have fine racks. Also 30.
If it is 5- or more, 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 32.51, the crystallized glass article obtained by heat treatment becomes fine and tends to have racks and pores. ZnO is an essential component as a crystal precipitation/growth promoter, and if it is less than S or OS, the crystal precipitation/growth rate will be slow and it will be difficult to precipitate sufficient crystals, but if it is more than 10.5%, crystals will Because the precipitation and growth rate is too fast, devitrification tends to occur during melting and molding.

Next, the subcomponents contained together with the four main components will be explained. B2O5 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. K2O is an effective component that has the effect of improving formability and slowing down the rate of crystal precipitation and growth, and it is preferable to finely control the rate of crystal precipitation and growth by adding a small amount. When the temperature increases, it becomes difficult to precipitate sufficient crystals. Na2O
is an effective component for lowering the melting temperature, lowering the viscosity, and improving the moldability, but if it exceeds 3.5%, fine cracks and racks are likely to occur in the crystallized glass article obtained by heat treatment. 6. TIO is an effective ingredient for suppressing devitrification, but when its content is high, it exhibits an unfavorable grayish color tone.6. It is desirable to keep it below Os.

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, with the remainder being impurities and appropriate fining agents commonly used in the production of glass articles. 1. Common glass compositions such as colorants can be added as needed.

For example, L1200 to 1.5% is an effective component for lowering the melting temperature and viscosity, and Ba00 to 5% is a divalent oxide similar to CaO. O%, Mg00~3.
0%, and Pb00~5.0%, tAl2O3+
Known fining agents such as 5b2o31Ce O2 θ~1.
O%, known colorants Coo, CuO, NiO, F
Adding an effective amount of e2O, etc., does not cause any inconvenience.

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 and melting the resulting glass, using a roll-out method or a press method.

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.
Raise the temperature at a rate of 50 to 300 r/h and heat to 1000 to 12
Heat treatment is carried out by holding at 00° C. for 3 to 6 hours to cause acicular anorthite and dendritic gehlenite to precipitate and grow from the surface of the crystalline glass molded article.

The crystallized glass article according to the present invention can be easily produced by the above-described simple one-step heat treatment after molding, or by a method in which cracks are created at least on the surface or the vicinity of the crystallized glass article before heat treatment, and then heat treatment is performed. so-called cracking method)
, crystalline glass in crystalline glass melt, crystallized glass,
Alternatively, it is also possible to apply a method in which small pieces of amorphous glass are dispersed and then heat-treated (so-called dispersion method), and each manufacturing method can have its own characteristics.

The decorative, natural stone-like aesthetic appearance exhibited by the crystallized glass article of the present invention can be obtained by heat-treating glass that is melted and shaped using raw materials within the above-mentioned predetermined composition range.

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 the 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 nitrate2. titanium oxide,
Lithium carbonate, barium carbonate, magnesium hydroxide, red lead, arsenite, antimony oxide.

After preparing patches satisfying the compositions of A1 to A13 in Table 1 using cerium oxide as a raw material, each patch was placed in a platinum crucible and melted in an electric furnace at a temperature of 1450° C. for 6 hours.

The obtained molten glass was poured into a metal mold, and
Form into a plate shape of approximately 300 x 15 cm, and transfer the glass plate onto a fireproof plate whose top surface has been coated with mold release agent powder, or into a fireproof mold whose inner surface has been coated with mold release agent powder. , 200℃Aour to a temperature of 1050℃ in a heat treatment furnace
Heat treatment was carried out by increasing the temperature at a rate of 1,050°C and holding it for 4 hours and 30 minutes. When the temperature reaches approximately 950°C, needle-like and dendrite crystals begin to precipitate and grow from the surface of the sheet glass toward the inside, and as the heat treatment continues, coarse needle-like and dendrite crystals aggregate. We were able to obtain a crystallized glass plate that is a solid body. When the surface of the 1 ft. obtained crystallized glass plate was polished, a beautiful natural stone-like appearance was obtained. As a result of X-ray diffraction measurement and observation using a microscope, it was found that the needle-like crystals were anorthite, the dendrites were gehlenite, and almost no other crystals were observed.

The results of physical property measurements show that all crystallized glass plates obtained from compositions 41 to 413 in Table 1 have thermal expansion coefficients of 55 to 55.
65X10/'C, bending strength 500 to 600 ν/ly
n'' range, and had sufficient physical properties for practical use as architectural and decorative materials.
Thermal expansion coefficient of natural marble ioo ~ 200 x 10-'
This is clear when compared with the physical property values of /l and bending strength of 100 to 250 pieces.

〔Effect of the invention〕

The crystallized glass article obtained by the present invention exhibits an excellent natural stone-like aesthetic appearance as a novel product having unprecedented CaO-AZ20 s -8I O2-based anorthite crystals and dalenite crystals, and also has excellent physical properties. It exhibits excellent properties that can be put to practical use as a building material or decorative material, and its usefulness is great.

Claims (1)

[Claims] A crystallized glass article in which crystals are precipitated and grown by heat treatment, the glass composition before crystal precipitation being SiO by weight ratio.
_2 32.0-42.0%, Al_2O_3 21.
5-30.5%, CaO 23.0-32.5%, Zn
O 5.0-10.5%, B_2O_3 0-4.5%
, K_2O 0-1.5%, Na_2O 0-3.5%
, TiO_2 0 to 6.0%, the total amount of each of these components is 95% or more of the whole, and a natural stone-like crystallized glass article characterized by having anorthite and gehlenite crystals.