JPS6238309B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a crystallized glass molded product and a method for manufacturing the same. BACKGROUND ART A crystallized glass molded product in which fine crystals are formed inside the glass molded product is useful as a molded product with a beautiful appearance that can be compared with natural marble, granite, etc. due to the incident and reflection effects of light rays. The important issues in manufacturing crystallized glass molded products are the composition of the raw materials that can produce crystals with the desired appearance, the appropriate viscosity of the melt to enable molding, and the crystallization heat treatment for crystal formation. temperature control. Currently, there are two methods for manufacturing crystallized glass molded products: a melting method and a sintering method. In the sintering method, glass powder with a composition capable of forming a specified crystal is heated at an intermediate temperature range higher than the softening point and lower than the melting point, and the glass powder is unified by sintering in a fused form. This is a method of obtaining a product by performing a crystallization heat treatment in which crystals are precipitated inside the molded product by operating at a temperature and time of This method is completed by performing crystallization heat treatment by molding and then reheating. Melting methods can be further divided into processing and molding methods and casting methods. Processing and molding methods are suitable for continuous mass production of products, and include roll processing, such as sheet glass, and stamping, such as containers.
By manufacturing crystallized glass molded products using this processing and molding method, it is possible to expect quality stability and economical effects due to mass production. However, it would be extremely desirable if it were possible under the above-mentioned normal manufacturing conditions for plate glass. However, in order to produce a crystallized glass molded product using a normal plate glass production method, there are essential conditions regarding viscosity and temperature. For example, as a standard condition, the raw material mixture is melted (1300 to 1500℃), and after leaving the furnace, the flow rate is 10 ^1.5 to ^{10 2.0 poise} (1200℃ to 1300℃), and then gradually continuous at the feeder position ^. viscosity decreases,
The viscosity-temperature conditions are such that it is 10 ³ to 10 ⁵ poise (950°C to 1200°C) at the start of molding by the molding machine, and 10 ⁷ poise (around 750°C) at the end of molding, and the time is dependent on the product. Although it varies depending on the quantity and size, it takes about 25 to 50 minutes from the time it is taken out of the oven to the end of molding. Next, it is charged into a lehr, but the temperature and time of the lehr can be varied slightly, and the upper limit temperature is the viscosity that does not cause deformation of the molded product, that is, the softening temperature (700℃ to 800℃), and it is kept constant. It is possible to control the temperature, maintain the temperature for a certain period of time, etc. The essential difference between crystallized glass molded products and ordinary glass molded products is that the former undergoes crystallization treatment under strictly controlled conditions of temperature and time. In addition, when the melt is slowly cooled at a constant temperature at which crystals begin to precipitate, the viscosity increases rapidly (over 10 ⁷ poise) and becomes semi-solid. When applied to a product, the composition must be such that this phenomenon does not occur by the end of the molding process. Therefore, it is necessary to obtain a molded product by matching the temperature conditions for normal glass manufacturing methods with the temperature conditions that prevent crystals from precipitating due to supercooling. Therefore, the crystallization treatment of the molded product is performed by reheating. I have no choice but to. In this case, the common operation of the conventional method is the primary crystallization heat treatment step, which can be called the crystal nucleation step or ultrafine crystal precipitation step, in which the molded product is heated from a low temperature and carried out at a constant temperature. The production is carried out by adding a second crystallization heat treatment step, which can be called a crystal growth step, which is further heated and carried out at a constant temperature. In the crystallization heat treatment process, if the temperature conditions of the first crystallization heat treatment and the second crystallization heat treatment are performed at a temperature higher than the softening temperature at which the molded product deforms, or if they require a long time, , a special heating furnace process must be added to the post-molding process of the normal glass manufacturing method. The types of crystals produced in crystallized glass molded products using conventional processing and molding methods are β-wollastonite and β-wollastonite.
- spodiumen, β-eucryptite, etc. However, the problem with this conventional method is that, as mentioned above, a crystallization heat treatment step by reheating after molding is essential. This addition process varies slightly depending on the type of crystal, but approximately 700
Increase the temperature from above ℃ while controlling the temperature to a final temperature of 1000℃.
Crystallization heat treatment is performed at a temperature range of ~1200℃. In addition, this temperature range is above the softening deformation temperature of the molded product (800 to 850℃), so in order to prevent deformation, the molded product must be placed on a specific baking table and subjected to crystallization heat treatment. . The casting method, which is another method of the melting method, uses a composition that has a small difference between the melting temperature and the crystal precipitation temperature in the state of crystal formation, and also allows crystal formation to start easily even if the cooling rate is fast. This is a method for manufacturing crystallized glass molded products. An example of this is a method for producing mica glass ceramics that produces crystals of phlogopite or tetrasilicon mica, which are crystals belonging to the fluorine mica family. The composition for producing mica glass ceramics is such that at least phlogopite or tetrasilicon mica crystals are present in the weight of the molded product.
It has a composition that produces 90% or more. Also, phlogopite [KMg ₃ (AlSi ₃ O ₁₀ ) F ₂ , melting point (mp)
1375℃, crystal precipitation temperature ( _{cp) 1375℃] or tetrasilicon mica [KMg 2.5 (} Si ₄ O ₁₀ ) F ₂ m.p1176
℃, c.p1173℃], these melts (1300 to 1450℃) have a rate of 60 to 100℃ per minute.
Crystal precipitation begins even at a cooling rate of 120°C, and at slower cooling rates, crystal formation is significantly promoted and the viscosity rises rapidly, reaching a semi-solid viscosity range between the respective crystal precipitation temperatures and 100°C. (10 ^{7.0 poise} )
Therefore, it is impossible to apply the manufacturing method based on the viscosity-temperature conditions of glass products by ordinary processing methods as the object of the present invention. That is, the viscosity is too high, leading to problems such as fractures and cracks occurring during molding, and insufficient heat resistance of processing equipment. Current mica glass ceramics are made by pouring a molten material into a mold under supercooled conditions to obtain a molded product, followed by crystallization heat treatment by reheating and holding at 750 to 850°C for 1 to 6 hours to generate crystal nucleation. The two-stage operation is an essential process: a crystal growth stage and a crystal growth stage held at 1000 to 1150°C for 1 to 6 hours. The present invention particularly performs conventional β-wollastonite and β-spodiumene-based crystallized glass molded products or mica-glass-ceramics by casting in a high-temperature, high-viscosity state or by crystallization treatment at high temperatures for a long period of time. This makes it possible to perform molding and crystallization within the scope of normal glass product manufacturing processes without causing any problems, and it is also possible to further increase the amount of crystallization or add crystallization as necessary to express the pattern of the molded product. Even when the crystallization treatment is performed by reheating to increase the diameter, it is possible to perform the crystallization treatment at a temperature below which the molded product does not soften or deform. In the present invention, by blending glass or glass components (hereinafter referred to as glass substances) with specific fluorine mica or its derivatives or their raw material components, crystal precipitation is caused by a melting method. This makes it possible to manufacture crystallized glass molded products using the glass product molding method and temperature treatment conditions. Fluorine mica has the chemical formula: X _{0.5 ~ 1.0} Y _{2.0 ~ 3.0}
(Z ₄ O ₁₀ )F ₂ . In this formula, X has a coordination number of 12
Z is a cation with a coordination number of 4, which is usually SiO ₄
It is based on tetrahedral Si, and Y is a cation with a coordination number of 6 and forms an octahedral layer. The crystal structure of fluorine mica is a hexagonal network of SiO ₄ tetrahedra, with two plates on the top and bottom, between which ions with octahedral coordination are bonded, and this structure is called a tablet.
These tablets are stacked on top of each other,
Alkali or alkaline earth metal ions are bound between the tablets and are called interlayer ions. The basic forms in which this fluorine mica crystal is produced are two methods: melting the raw materials according to the crystal composition and precipitating the crystals by treating the melt under certain temperature conditions, and the other method using the mixed raw materials as a powder. When heated in the state of solid particles or in the state of a molded product, reactions such as dehydration and decomposition of adsorbed water occur one after another, and even before the melting temperature is reached, atoms at crystal lattice points on the surface of the particles are There is a solid phase reaction method in which crystals are formed by entering the radius of action of the atoms on the surface of the particle and breaking bonds, and there are crystals that can be formed by this solid phase reaction even if the melting method cannot be applied. Whether or not crystals can be formed using the melting method or the solid phase reaction method is determined by experimenting with various compositions. The fluorine mica crystals produced in the crystallized glass molded product according to the present invention belong to a mechanism in which crystals are produced by a melting method, and contain Taniolite crystals as a main component. _{Taeniolite has the general formula of the fluorine mica :} X
According to the composition of Z and Z, it can be classified as follows. (1) X is a monovalent cation K ⁺ and Z is Si ₄ (tetrasilicon type), typical example: KMg ₂ Li (Si ₄ O ₁₀ ) F ₂ , melting point (mp) 1210
℃, crystal precipitation point (cp) 1185℃] (2) X is a divalent cation Ba ²⁺ , Sr ²⁺ , Pb ²⁺ or Cd ²⁺ and Z is Si, typical example: [Ba _{0.5 Mg2Li} ( _Si4O10 ) _F2 , _m.p1070 ℃, c _.
p1050℃] [Sr ₀ . ₅ Mg ₂ Li (Si ₄ O ₁₀ ) F ₂ , m.p1050, c.
p1050] [Pb ₀ . ₅ Mg ₂ Li (Si ₄ O ₁₀ ) F ₂ , m.p1120, c.
p1120] Crystals are produced by other melting methods of these (1) and (2) taeniolites, including the following (3). (3) Y is Mg ₂ Li, X is a divalent cation Ba ²⁺ ,
Derivatives of taeniolite which are Sr ²⁺ , Pb ²⁺ or cd ²⁺ and Z is AlSi ₃ or BSi ₃ , typical examples: [Ba ₀ . ₅ Mg ₂ Li (AlSi ₃ O ₁₀ ) F ₂ , m. p1225℃,
c.p1225℃] [Ba ₀ . ₅ Mg ₂ Li (BSi ₃ O ₁₀ ) F ₂ , m.p968℃, c.
p968℃] In order to precipitate the teniolite crystals and teniolite derivative crystals (hereinafter referred to as the teniolite crystals) described in (1), (2), and (3) above on glass, the teniolite crystals may be used as the raw material. It may also be a raw material composition thereof (hereinafter referred to as a taeniolite composition). The object of the present invention is achieved by a composition that combines the above-described taeniolite composition and a glassy substance. The crystallized glass material used in the present invention may be a raw material batch capable of forming glass, or a frit-like glass obtained by vitrifying this raw material batch in advance and then crushing it. Examples of glass components include:
SiO ₂ ―Al ₂ O ₃ ―B ₂ O ₃ ―CaO―K ₂ O―Na ₂ O or this with P ₂ O ₅ , BaO, MgO, ZnO, PbO, TiO ₂ ,
ZrO ₂ or the like is added as appropriate, and glass materials such as plate glass, bottle glass, pressed glass, lighting glass, sealing glass, crystal glass, etc. can be used in the usual classification of glass products.
When selecting the composition of the glass material, care must be taken not to inhibit the formation of taeniolite crystals, and to maintain viscosity-temperature conditions that allow the forming process to be completed without any problems. That is, the composition formula of taeniolite is X _{0.5 ~ 1.0} Mg ₂ Li
(Si ₄ O ₁₀ ) F ₂ , for example, when the purpose is to produce K-teniolite (KMg ₂ Li(Si ₄ O ₁₀ ) F ₂ crystal, other The ions Ba ²⁺ , Pb ²⁺ , Zn ²⁺ , etc. must be limited to within a certain value, preferably so that the crystal formation rate due to these ions in the entire composition is about 20%, and Ba-theniolite [ _{Ba0.5Mg2Li _ _}
(Si ₄ O ₁₀ )F ₂ ] is also the same as described above. Furthermore, in the case of taeniolite derivatives, it is also necessary to limit Al ³⁺ and B ³⁺ , which can coordinate to the Z position, so that the crystal formation rate due to these ions in the entire composition is within about 20%. . The blending ratio of the teniolite composition and the glassy substance is preferably 30 to 70 parts by weight when the total composition is 100 parts by weight. In the combination of the taeniolite-based composition and the glassy substance according to the present invention, the temperature-viscosity conditions are different from the time when the mixed melt is taken out of the furnace to the time when the molding is completed. ~
The viscosity decreases continuously from 1300℃, viscosity 10 ^{1.5 to 10 2.0 poise} ) until it is loaded into the molding machine using a feeder, and then at the start of molding (950 to 1100℃, 10 ^3.0 to ^{10 5 poise} ). ⁰ poise) to the end of molding (950 to 850°C, 10 ^6.5 to ^{10 7.0} poise), and the phenomenon of viscosity increase due to crystal formation does not occur during this time ^. It is possible to produce molded products without damage. In addition, the crystallization heat treatment process that generates crystals inside the molded product can be achieved by holding it at 700 to 850°C for 40 to 60 minutes after the molding is completed, and can be carried out continuously after the molding is completed within the temperature operating range of the slow cooling process. Therefore, a crystallized glass molded product can be completed within the framework of a substantially normal glass product manufacturing process. Furthermore, among the taeniolite compositions, those in which X is Ba ²⁺ [for example, Ba ₀ . ₅ Mg ₂ Li (Si ₄ O ₁₀ )
F ₂ , BaMg ₂ Li (AlSi ₃ O ₁₀ ) F ₂ , BaMg ₂ Li
(BSi ₃ O ₁₀ )F ₂ ] has the effect of lowering the viscosity of the melt, so it not only prevents the viscosity from changing suddenly from the melt to the end of molding, but also prolongs the time required until the end of molding. effective. In the present invention, the fluorine mica to be mixed with the glassy substance uses a teniolite composition as an essential raw material, but other fluorine mica can be added as necessary. For example, the above-mentioned viscosity reducing effect
By making Ba-teniolite coexist with crystalline fluorine mica such as K-phlogopite and K-tetrasilicon mica, the crystallinity of these fluorine mica at high temperatures can be suppressed, or by combining it with glassy substances. It is possible to suppress an increase in the viscosity of the mixed melt, and to increase the amount of crystals produced in a molded product when subjected to crystallization heat treatment. Furthermore, in the combination of a taeniolite composition and other fluorine mica, in addition to introducing fluorine mica crystals by the above-mentioned melting method, a certain amount of fluorine mica composition produced by a solid phase reaction mechanism is added. It is also possible to co-form crystals and obtain colored crystallized glass molded products. Hereinafter, the crystallized glass molded product of the present invention will be specifically explained with reference to Examples. Example 1 The component composition of the glassy substance is SiO ₂ 72%,
Na ₂ O 13.5%, CaO 12.2%, MgO 1.0%, Al ₂ O ₃₊ ,
The composition of 45 parts by weight of 1.3% Fe ₂ O ₃ and Ba-teniolite [Ba ₀ . ₅ Mg ₂ Li (Si ₄ O ₁₀ ) F ₂ ] is
SiO ₂ 54.5%, BaO 17.4%, Li ₂ O 3.4%, MgO 9.1
A batch of raw materials containing 55 parts by weight of 15.6% MgF ₂ was melted at 1400° C., and a crystallized glass molded product was produced in accordance with the manufacturing process of plate glass. 1350℃ from the furnace, through the feeder, and just before charging into the molding machine
The viscosity of the melt at ^a cooling rate of 35 minutes from to 900°C is 1300°C - ^{10 1.6 poise , 1200°C - 10 2.8 poise, 1100°C - 10 3.5 poise , 1000} °C - 10 ^4.5 The temperature was 900°C - ^{10 5.2} poise. 900℃～800℃
After forming into a plate with a thickness of about 20 mm by roll forming, a milky white crystallized glass molded product was obtained by crystallization treatment at a temperature of 800°C for 50 minutes. The physical properties of this molded product are porosity 0, specific gravity 2.79, hardness (shoer) 85, transverse rupture strength 920 Kg/cm ² , and according to X-ray diffraction, electron micrograph and other measurements,
Mainly Ba ₀ . ₅ Mg ₂ Li (Si ₄ O ₁₀ ) F ₂ crystal (more than 95%)
It was observed that 30 to 40% by weight of mica crystals were formed in the molded product, and the crystal grain size was distributed in the range of 300 to 700 μm. Example 2 In the above molded product formulation, 16.5 parts by weight of 55 parts by weight of Ba-teniolite was added to K-phlogopite [KMg ₃
(AlSi ₃ O ₁₀ )F ₂ ] Composition of SiO ₂ 41.8%, K ₂ O 10.9%,
A plate-like body was produced by replacing the material with one consisting of 11.8% Al ₂ O ₃ , 18.7% MgO, and 16.8% MgF ₂ . The compound was melted at 1450℃ in a melting furnace, and then the molten material discharged from the furnace was
Cool to 1200℃. The viscosity at 1200°C was 10 ^3.8 poise, and the viscosity ^at 1100°C was 10 ^{4.2 poise} . A portion of it was poured onto a heat-resistant stainless steel plate and rapidly cooled to obtain a sample piece. When observing this sample piece, it was found that 10μ
It was observed that a small amount of fine crystals around m were homogeneously distributed. The molten material at about 1100℃ is sent to a feeder, then charged into a roller molding machine through the feeder, and molded into a plate-like material about ^20mm thick at a viscosity of ^106.0 poise at a temperature between 900 and 800℃ without damage. A molded body was obtained. Next, a primary crystallization treatment was carried out by heating at 800°C for about 1 hour, and a secondary crystallization heat treatment was further carried out at 1050°C for about 1 hour to obtain a crystallized glass molded product.
When observed and measured, K-phlogopite crystals had grown to a size of 500 μm to 2000 μm and were scattered throughout the molded product, and the polished surface had a beautiful marble-like appearance. Example 3 Mixture (1) Suitable for light bulb glass as base material glass
_SiO2 67.4%, _{Ai2O3 1.0} %, _{B2O3 4.5} %, CaO4.6
%, K ₂ O 12.0%, Na ₂ O 2.5%, ZnO 4.0%,
60 by weight raw material batches adjusted to BaO4%
(2) SiO ₂ 43.4%, a compound for the purpose of crystal formation of taeniolite [Ba Mg ₂ Li (AlSi ₃ O ₁₀ ) F ₂ composition];
BaO18.5%, Li ₂ O 3.5%, MgF ₂ 16.6%,
35 parts by weight of a _raw material batch adjusted to MgO 9.6% and B ₂ O ₃ 8.4%, (3) Co _- synthesized fluorine mica [KMg _1.5 Co _1.5
(AlSi ₃ O ₁₀ ) F ₂ composition] SiO ₂ 36%, K ₂ O 9.5%, Co ₂ O ₃ 25%,
5 parts by weight of a raw material batch adjusted to 19.3% MgF ₂ and 10.2% Al ₂ O ₃ were homogeneously mixed with these raw material batches (1), (2), and (3) to prepare a raw material batch. Manufacturing 1 kg of raw material batches are placed in a SiC crucible, melted in a Matsufuru Elema furnace at 1400°C for 30 minutes, taken out of the furnace, and the molten material is heated together with the crucible in the atmosphere from 1400°C to 1100°C.
Allow to cool at a cooling rate of 30-35℃/min, then cool to 1100℃
Adjust the temperature drop by heating the outer periphery of the crucible to 1000℃ for at least 20 minutes with a gas flame, take out the molten material from the crucible, and spread and shape it at 850 to 20℃ using an experimental mini roller made of Stellite heat-resistant steel. A pale blue body measuring 10 cm and approximately 35 cm in length was obtained. When the temperature of the molded body reached 750°C, it was placed in an electric furnace that had been previously maintained at 750°C, held at 750°C to 740°C for 25 minutes, and then cooled in the furnace with the electricity turned off. After the molded body was taken out of the furnace, its upper and lower surfaces were polished to a mirror finish using a conventional polishing method to obtain a crystallized glass molded product. The product had a beautiful pattern of homogeneous clusters of pale blue sesame-like crystals. In addition, the physical properties of the product are a specific gravity of 2.81,
Transverse bending strength 720Kg/cm ² , Shore hardness 92, Shorey impact strength 2.6Kg-m/cm ² , Coefficient of thermal expansion (30-500
℃) 75×10 ^-7 . Example 4 Formulation (1) Glass composition (wt%)

【table】 (2) Fluorine mica composition

【table】 Manufacture of crystallized glass molded products

[Table] Appearance The product that underwent the polishing process became beautiful due to the formation of crystals. Product performance

【table】

Claims (1)

[Scope of Claims] 1. A crystallized glass molded product comprising a molten solidified glass substance and taeniolite crystals. 2. A method for producing a crystallized glass molded product, which comprises mixing a glassy substance and a taeniolite composition, melting it, processing and molding it, and then cooling it.