JP2012201526A - Crystallized glass article and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crystallized glass article having excellent thermal durability and mechanical strength, showing a high-grade appearance, and capable of giving an excellent designing property, and to provide a method for manufacturing the article.SOLUTION: The crystallized glass article is produced by accumulating crystalline glass small bodies, and melting and integrating the accumulated material by heat treatment to crystallize. The crystallized glass article contains LiO-AlO-SiO-based crystals by 20 to 70 mass% and RO-AlO-SiO-based crystals (where R represents Mg, Ca, Sr or Ba) or R'O-AlO-SiO-based crystals (where R' represents Na or K) by 1 to 75 mass%.

Description

  INDUSTRIAL APPLICABILITY The present invention can be used for a glass top plate for a cooker used for a gas stove or the like, a decoration material such as a top plate of a kitchen facility, or a heating appliance component, and can be provided with an excellent design. The present invention relates to a crystallized glass article and a manufacturing method thereof.

  In recent years, as a crystallized glass article used as a decorative material such as a glass top plate for a cooking stove, a top plate of a kitchen facility, or a heating appliance component, it has thermal durability, chemical durability, mechanical A material that is excellent in properties such as strength and has a new appearance different from natural stones, ceramics, and tiles is being pursued. Crystallized glass articles having various appearances have been developed and proposed in accordance with such demands for diversifying design properties.

  For example, in Patent Document 1, an inorganic pigment is attached to the surface of a glass body where crystals are precipitated while being softened and deformed when heat-treated at a temperature higher than the softening point, and the crystals are fused and integrated by heat treatment. In addition, a crystallized glass article is disclosed in which a colored layer appears at the interface of each glass body. Further, Patent Document 2 discloses that glass bodies of different colors of the same material are scattered on the surface of a sheet glass on which crystals precipitate while softening and deforming when heat-treated at a temperature higher than the softening point, and fused and integrated after the heat treatment. A patterned crystallized glass is disclosed. Further, Patent Document 3 discloses a decorative low expansion crystallized glass plate in which a decorative coating made of borosilicate glass frit containing an inorganic pigment is formed on the surface of black low expansion crystallized glass.

JP-A-1-157432 Japanese Patent Laid-Open No. 2-92840 Japanese Patent Laid-Open No. 9-183631

Since the crystallized glass article disclosed in Patent Document 1 and the patterned crystallized glass disclosed in Patent Document 2 have a large linear thermal expansion coefficient of 60 × 10 ⁻⁷ / K or more, Durability is insufficient, and when used for high-temperature applications such as a glass top plate for a cooker, there is a risk of damage.

  The decorative low-expansion crystallized glass plate described in Patent Document 3 has no problem with thermal durability, but is likely to cause a problem of peeling of the decorative coating. Moreover, since the reflectance of the glass surface is low, for example, as a decorative material, the brightness is poor and the design is poor.

  Therefore, the present invention provides a crystallized glass article that is excellent in thermal durability and mechanical strength, has a high-grade appearance, and can impart excellent design properties, and a method for producing the same. Objective.

The present invention is a crystallized glass article obtained by accumulating crystalline glass bodies, fused and integrated by heat treatment, and crystallizing Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystals from 20 to 70. RO-Al ₂ O ₃ —SiO ₂ based crystal (R = Mg, Ca, Sr, Ba) or R ′ ₂ O—Al ₂ O ₃ —SiO ₂ based crystal (R ′ = Na, The present invention relates to a crystallized glass article comprising 1 to 75% by mass of K).

  In order to integrate the crystalline glass bodies and fuse and integrate and crystallize them by heat treatment, it is necessary to reduce the amount of precipitated crystals in order to ensure softening fluidity on the surface of the crystalline glass bodies. However, when the amount of precipitated crystals is reduced, the linear thermal expansion coefficient increases and the thermal durability tends to decrease.

The crystallized glass article of the present invention is obtained by subjecting Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystal to 20 to 70 mass% and RO—Al ₂ O ₃ —SiO ₂ based crystal (R = Mg) by crystallization treatment. , Ca, Sr, Ba) or R ′ ₂ O—Al ₂ O ₃ —SiO ₂ -based crystal (R ′ = Na, K), 1 to 75% by mass, and a specific amount of two or more types of crystals are precipitated. Therefore, it has low expansion, excellent thermal durability, and excellent mechanical strength. In addition, since these crystals are precipitated from the inside of the crystalline glass body, they are superior in softening fluidity on the glass body surface compared to the case where crystals are deposited from the glass surface, and there are pores at each glass body interface. It becomes difficult to remain. As a result, the crystallized glass article of the present invention has excellent surface smoothness and moderate surface gloss. Therefore, it is suitable as a glass top plate for a cooker used for a gas stove or the like, a decorative material such as a top plate of a kitchen facility, or a heater component (for example, a top plate or wall material of a heater). Further, since the crystallized glass article of the present invention is formed by fusing and integrating the crystalline glass bodies with each other, as described later, a colored layer is provided at the interface of each glass body, By coloring the body itself, it is possible to obtain a crystallized glass article having various appearances and excellent design properties.

  The mechanism by which the crystallized glass article of the present invention has an excellent low linear thermal expansion coefficient will be described below.

The Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystal and the RO—Al ₂ O ₃ —SiO ₂ based crystal or the R ′ ₂ O—Al ₂ O ₃ —SiO ₂ based crystal are both anisotropic. It is known to have linear thermal expansion characteristics (that is, the linear thermal expansion coefficient varies depending on the crystal axis). Therefore, in the crystallized glass containing these crystals, shear stress is generated at the interface between the negative expansion axis side of the crystal and the matrix glass having positive expansion in the cooling process of the crystallization process. Along with this, voids are generated in the matrix glass. The voids reduce the contribution of the matrix glass and the positive expansion of the crystal in the crystallized glass, while the contribution of the negative expansion of the crystal is emphasized and a low linear thermal expansion coefficient can be achieved. In general, the linear thermal expansion coefficient of crystallized glass is additively determined by the average linear thermal expansion coefficient and volume fraction of the crystal and matrix glass, respectively. The coefficient of linear thermal expansion is lower than that predicted from the law.

  Moreover, in the crystallized glass article of the present invention, voids present in the matrix glass also contribute to an improvement in specific heat. Therefore, when the crystallized glass article of the present invention is used as, for example, a heater component, a high heat retention effect can be obtained.

  In the present invention, “crystalline glass” refers to glass on which crystals are precipitated by heat treatment.

Secondly, the crystallized glass article of the present invention preferably has a linear thermal expansion coefficient of 30 × 10 ⁻⁷ / K or less at 30 to 380 ° C.

  Here, “linear thermal expansion coefficient at 30 to 380 ° C.” refers to a value measured using a dilatometer.

  Third, the crystallized glass article of the present invention preferably contains a β-spodumene solid solution and a potassium feldspar solid solution.

  Fourth, the crystallized glass article of the present invention preferably has an average crystal grain size of 0.5 μm or more.

Fifth, in the crystallized glass article of the present invention, the crystalline glass body has a glass composition of mass%, SiO ₂ 55 to 72%, Al ₂ O ₃ 14 to 30%, Li ₂ O 1.5. _{~10%, Na 2 O 0~10%} , K 2 O 1~10%, TiO 2 0~3%, ZrO 2 0~3%, 0~10% MgO, CaO 0~10%, SrO 0~10 %, BaO 0 to 10%, ZnO 0 to 5%, B ₂ O ₃ 0 to 3%, P ₂ O ₅ 0 to 1% are preferably contained.

  Sixth, the crystallized glass article of the present invention is a small crystalline glass product obtained by adhering 0.1 to 3 parts by mass of metal oxide powder or inorganic pigment powder to 100 parts by mass of crystalline glass bodies. It is preferable that a colored layer using the body appears.

  According to this configuration, a crystallized glass article is obtained, which is made of a metal oxide powder or an inorganic pigment powder, and has a network pattern with excellent design, at the interface between the crystallized glass bodies fused together. It becomes possible.

  Seventh, in the crystallized glass article of the present invention, it is preferable that at least a part of the crystalline glass body contains 0.1 to 5% by mass of a coloring component in the glass composition.

  According to this configuration, a colored crystallized glass article can be obtained. In particular, by using a mixture of a crystalline glass body containing a coloring component and a crystalline glass containing no coloring component, it is possible to obtain a crystallized glass article having a spotted pattern in which a colored portion and a non-colored portion are mixed. It becomes possible.

  Eighth, the crystallized glass article of the present invention is preferably used for a cooker top plate, a kitchen equipment decoration material, or a heater component.

  Ninth, the present invention is a method for producing any one of the above-mentioned crystallized glass articles, wherein the crystalline glass bodies are accumulated in a refractory mold, and the softening point of the crystalline glass bodies is exceeded. It is related with the manufacturing method characterized by heat-processing at the temperature of this, and carrying out fusion integration and crystallization.

The crystallized glass article of the present invention is a crystallized glass article obtained by accumulating crystalline glass bodies, fused and crystallized by heat treatment, and is based on Li ₂ O—Al ₂ O ₃ —SiO ₂ system. RO-Al ₂ O ₃ —SiO ₂ based crystal (R = Mg, Ca, Sr, Ba) or R ′ ₂ O—Al ₂ O ₃ —SiO ₂ based crystal ( R ′ = Na, K) is contained in an amount of 1 to 75% by mass.

The content of the Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystal is preferably 20 to 70% by mass, particularly preferably 30 to 60% by mass. When the content of _{Li 2 O-Al 2 O 3} -SiO 2 based crystal is too small, the linear thermal expansion coefficient becomes large, tends to be inferior in thermal resistance. On the other hand, if the content of the Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystal is too large, the firing temperature tends to be high, for example, 1300 ° C. or higher, and it is not suitable for a normal firing furnace. Moreover, it becomes difficult to obtain the surface smoothness of the crystallized glass article.

Examples of the Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystal include β-spodumene solid solution and β-quartz solid solution.

The content of RO—Al ₂ O ₃ —SiO ₂ crystal or R ′ ₂ O—Al ₂ O ₃ —SiO ₂ crystal is 1 to 75 mass%, 5 to 60 mass%, 10 to 50 mass%, especially 20 It is preferable that it is -45 mass%. When _{RO-Al 2} O 3 content of -SiO ₂ based crystal and _{R '2 O-Al 2 O} 3 -SiO 2 based crystal is too small, the desired low coefficient of linear thermal expansion is difficult to obtain. On the other hand, when the content of the RO—Al ₂ O ₃ —SiO ₂ based crystal and the R ′ ₂ O—Al ₂ O ₃ —SiO ₂ based crystal is too large, the mechanical strength tends to decrease. In addition, when it contains 2 or more types of these crystals, it is preferable to satisfy | fill the said range with total amount.

The total amount of Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystal, RO—Al ₂ O ₃ —SiO ₂ based crystal and R ′ ₂ O—Al ₂ O ₃ —SiO ₂ based crystal is 35% by mass or more, In particular, it is preferably 40% by mass or more. If the total amount of these crystals is too small, the coefficient of linear thermal expansion increases, making it difficult to obtain the desired thermal durability. On the other hand, the upper limit is not particularly limited, but in order to sufficiently soften and flow the crystalline glass body surface, it is practically 99% by mass or less, particularly 95% by mass or less.

As specific examples of _{RO-Al 2} O 3 -SiO 2 based crystal are given below. As MgO—Al ₂ O ₃ —SiO ₂ crystal, cordierite, etc .; As CaO—Al ₂ O ₃ —SiO ₂ crystal, pyroxene, etc .; As SrO—Al ₂ O ₃ —SiO ₂ crystal, Slowsonite Etc .; Examples of BaO—Al ₂ O ₃ —SiO ₂ based crystals include heavy feldspar.

Specific examples of the R ′ ₂ O—Al ₂ O ₃ —SiO ₂ based crystal include the following. Examples of Na ₂ O—Al ₂ O ₃ —SiO ₂ -based crystals include feldspar and nepheline; and examples of K ₂ O—Al ₂ O ₃ —SiO ₂ -based crystals include potassium feldspar such as orthofeldspar, sanidine, and plagioclase. It is done.

Each crystal was listed as specific examples of the above _{RO-Al 2} O 3 -SiO 2 based crystal and _{R '2 O-Al 2 O} 3 -SiO 2 system crystal, it may be a solid solution.

The average particle diameters of the Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystal, RO—Al ₂ O ₃ —SiO ₂ based crystal and R ′ ₂ O—Al ₂ O ₃ —SiO ₂ based crystal are each 0.5 μm. In particular, the thickness is particularly preferably 1 μm or more. If the average particle size of these crystals is too small, the stress generated at the interface between the crystals and the matrix glass becomes small, and it becomes difficult to form voids in the matrix glass. As a result, it becomes difficult to obtain a desired low linear thermal expansion coefficient. The upper limit is not particularly limited, but if the average particle size of these crystals is too large, cracks are likely to occur at the interface between the crystal and the matrix glass, and the mechanical strength tends to decrease. It is preferably 200 μm or less, particularly preferably 100 μm or less.

  In addition, the average particle diameter of a crystal | crystallization is calculated based on the reflected electron image obtained from the scanning electron microscope observation of the crystallized glass surface.

Specifically, the average crystal grain size is calculated as follows. First, the reflected electron image is binarized using an image processing system, and the area of each crystal particle is measured. Next, from the area, a diameter (d _ni ) converted into a perfect circle is calculated by an equation of d _ni = √4 / π · A. In addition, A is the area of the crystal grain calculated by image analysis of the reflected electron image. Subsequently, an average particle diameter (d _n ) with respect to n particles is calculated according to an equation of dn = Σd _ni / n.

The linear thermal expansion coefficient of the crystallized glass article is preferably 30 × 10 ⁻⁷ / K or less, particularly preferably 20 × 10 ⁻⁷ / K or less. For example, in the gas range glass top, the temperature of the burner port that is the highest temperature due to the influence of the gas flame is 200 ° C. or higher. At that time, tensile stress is generated on the outer periphery of the low temperature glass top plate away from the burner port. When the linear thermal expansion coefficient of the crystallized glass article is too large, the tensile stress is also increased (for example, about 30 MPa or more), which may lead to breakage. The lower limit is not particularly limited, but if it is too low, the amount of crystal precipitation becomes too large, or the crystal grain size becomes too large, and the softening fluidity on the surface of the crystalline glass body tends to decrease. As a result, the crystalline glass bodies are difficult to fuse and integrate with each other, and the mechanical strength of the crystallized glass article tends to decrease. Therefore, it is preferable that the linear thermal expansion coefficient of the crystallized glass article is 0 × 10 ⁻⁷ / K or more, particularly 3 × 10 ⁻⁷ / K or more.

In the present invention, the linear thermal expansion coefficient of the crystallized glass article is greatly influenced by the conditions of the heat treatment step of the crystalline glass body, particularly the cooling rate. By changing the cooling rate, the crystal structure and the amount of voids in the glass matrix can be controlled, and a desired linear thermal expansion coefficient can be obtained. For example, in order to obtain a linear thermal expansion coefficient of 30 × 10 ⁻⁷ / K or less, it is preferable to cool at a rate of 200 ° C./hour or less after reaching the maximum temperature in the heat treatment step.

As the composition of the crystalline glass body, Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystal and RO—Al ₂ O ₃ —SiO ₂ -based crystal or R ′ ₂ O—Al ₂ O ₃ —SiO ₂ The system crystal is not particularly limited as long as the predetermined amount can be precipitated. Specifically, the crystallizable glass corpuscles, as a glass composition, in _{mass%, SiO 2 55~72%, Al} 2 O 3 14~30%, Li 2 O 1.5~10%, Na 2 O _{0~10%, K 2 O 1~10%} , TiO 2 0~3%, ZrO 2 0~3%, 0~10% MgO, CaO 0~10%, SrO 0~10%, BaO 0~10% ZnO 0 to 5%, B ₂ O ₃ 0 to 3%, P ₂ O ₅ 0 to 1% are preferably used.

  The reason for limiting the content of each component in this way will be described below. In the following description regarding the content of each component, “%” means “mass%” unless otherwise specified.

SiO ₂ is a main component of glass and a crystal component. The SiO ₂ content is preferably 55 to 72%, particularly preferably 60 to 70%. When the content of SiO ₂ is too small, crystal precipitation tends to be unstable. On the other hand, if the content of SiO ₂ is too large, the softening point becomes high and the surface fluidity of the crystalline glass body decreases, and the meltability tends to decrease and molding tends to be difficult. Furthermore, the linear thermal expansion coefficient of the matrix glass is lowered, the average linear thermal expansion coefficient difference from the precipitated crystal is reduced, and voids are hardly formed in the matrix glass. As a result, it becomes difficult to obtain a desired low linear thermal expansion coefficient.

Al ₂ O _{3 is} also a crystal constituent. The content of Al ₂ O ₃ is preferably 14 to 30%, particularly preferably 16 to 25%. When the content of Al ₂ O ₃ is less than 14%, the crystal is coarsened, and the surface smoothness and mechanical strength of the crystallized glass article tend to decrease. On the other hand, when the content of Al ₂ O ₃ is too large, with the meltability decreases, devitrification during molding tends to occur in the liquid phase temperature becomes higher.

Li ₂ O is also a crystal constituent. The content of Li ₂ O is preferably 1.5 to 10%, particularly 3 to 7%. When Li 2 _O content is too small, uniform crystals are difficult to obtain. On the other hand, when the content of Li 2 _O is too large, crystallinity becomes strongly reduced surface flow of the crystalline glass masses, the surface smoothness of the crystallized glass article tends to be lowered. Also, heat treatment control for obtaining a desired crystallinity tends to be difficult.

K ₂ O is a component constituting a K ₂ O—Al ₂ O ₃ —SiO ₂ -based crystal. It is also a component for controlling the crystallinity of the Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystal. Furthermore, the softening point is adjusted by adjusting the proportion of the glass phase, which also affects the surface fluidity of the glass body. The content of K ₂ O is preferably 1 to 10%, particularly preferably 3 to 7%. When K ₂ O content is too _{small, K 2 O-Al 2 O} 3 -SiO 2 based crystal is less likely to precipitate. On the other hand, when the content of _{K 2} O is too _large, the less amount of precipitation of _{Li 2 O-Al 2 O 3} -SiO 2 based crystal, the desired linear thermal expansion coefficient is difficult to obtain.

Na ₂ O is a constituent component of the Na ₂ O—Al ₂ O ₃ —SiO ₂ based crystal. It is also a component for controlling the crystallinity of the Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystal. Furthermore, the softening point is adjusted by adjusting the proportion of the glass phase, which also affects the surface fluidity of the glass body. The content of Na ₂ O is preferably 0 to 10%, particularly preferably 0 to 7%. When the content of Na ₂ O is too _large, the less amount of precipitation of _{Li 2 O-Al 2 O 3} -SiO 2 based crystal, the desired linear thermal expansion coefficient is difficult to obtain.

Incidentally, the total amount of _{K 2} O and Na ₂ O, in view of the above effects 1 to 20%, particularly preferably 3-10%.

MgO is a constituent component of the MgO—Al ₂ O ₃ —SiO ₂ based crystal. It is also a component for controlling the crystallinity of the Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystal. Furthermore, the softening point is adjusted by adjusting the proportion of the glass phase, which also affects the surface fluidity of the glass body. The content of MgO is preferably 0 to 10%, 0.1 to 9%, 1 to 8%, particularly 2 to 7%. When the content of MgO is too _large, the less amount of precipitation of _{Li 2 O-Al 2 O 3} -SiO 2 based crystal, the desired linear thermal expansion coefficient is difficult to obtain.

CaO is a constituent component of the CaO—Al ₂ O ₃ —SiO ₂ based crystal. It is also a component for controlling the crystallinity of the Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystal. Furthermore, the softening point is adjusted by adjusting the proportion of the glass phase, which also affects the surface fluidity of the glass body. The CaO content is preferably 0 to 10%, particularly preferably 0 to 7%. When the content of CaO is too _large, the less amount of precipitation of _{Li 2 O-Al 2 O 3} -SiO 2 based crystal, the desired linear thermal expansion coefficient is difficult to obtain.

SrO is a constituent component of the SrO—Al ₂ O ₃ —SiO ₂ based crystal. It is also a component for controlling the crystallinity of the Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystal. Furthermore, the softening point is adjusted by adjusting the proportion of the glass phase, which also affects the surface fluidity of the glass body. The SrO content is preferably 0 to 10%, particularly preferably 0 to 7%. When the content of SrO is too _large, the less amount of precipitation of _{Li 2 O-Al 2 O 3} -SiO 2 based crystal, the desired linear thermal expansion coefficient is difficult to obtain.

BaO is a constituent component of a BaO—Al ₂ O ₃ —SiO ₂ based crystal. It is also a component for controlling the crystallinity of the Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystal. Furthermore, the softening point is adjusted by adjusting the proportion of the glass phase, which also affects the surface fluidity of the glass body. The content of BaO is preferably 0 to 10%, 0.1 to 9%, 1 to 8%, particularly 2 to 7%. When the content of BaO is too _large, the less amount of precipitation of _{Li 2 O-Al 2 O 3} -SiO 2 based crystal, the desired linear thermal expansion coefficient is difficult to obtain.

  The total amount of MgO, CaO, SrO and BaO is preferably 1 to 20%, particularly 3 to 10% in view of the above effects.

TiO ₂ and ZrO ₂ are components that become nuclei during crystal precipitation, and have the effect of suppressing the coarsening of crystals and the effect of stably precipitating crystals. However, when the content is too large, Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystals are preferentially precipitated, and RO—Al ₂ O ₃ —SiO ₂ -based crystals and R ′ ₂ O -Al ₂ O ₃ -SiO ₂ based crystal is not easily precipitated. In addition, the crystallization speed increases and the glass tends to devitrify, and the surface fluidity of the crystalline glass body tends to decrease.

TiO ₂ and ZrO ₂ are also constituents of a rutile crystal (TiO ₂ ), a zirconia crystal (ZrO ₂ ), or a zirconium titanate crystal (ZrTiO ₄ ). Since these crystals have a relatively high refractive index, increasing the content of TiO ₂ and ZrO ₂ makes it easy to obtain a crystallized glass article with high whiteness. Conversely, by reducing the content of TiO ₂ and ZrO ₂ , it becomes difficult for the rutile crystal, the zirconia crystal and the zirconium titanate crystal to precipitate, and a crystallized glass article having excellent transparency can be easily obtained.

In view of the above, the content of TiO ₂ is preferably 0 to 3%, 0 to 2%, particularly preferably 0 to 1.5%. The content of ZrO ₂ is preferably 0 to 3%, 0 to 2%, 0 to 1.4%, particularly preferably 0.1 to 1%. The total amount of TiO ₂ and ZrO ₂ is preferably 0 to 5%, 0 to 3%, 0 to 2%, 0 to 1.4%, particularly preferably 0.1 to 1%.

ZnO is a constituent of garnite crystals. Since garnite crystals have a relatively high refractive index, it is easy to obtain a crystallized glass article with high whiteness by positively adding ZnO. However, if the content of ZnO is too large, the precipitation of garnite crystals increases, and Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystals, RO—Al ₂ O ₃ —SiO ₂ based crystals and R ′ ₂ O precipitation amount -Al ₂ O ₃ -SiO ₂ based crystal tends to decrease. Therefore, the ZnO content is preferably 0 to 5%, particularly preferably 0 to 4%.

B ₂ O ₃ is a component for controlling the crystallinity of the Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystal. Furthermore, the softening point is adjusted by adjusting the proportion of the glass phase, which also affects the surface fluidity of the glass body. The content of B ₂ O ₃ is preferably 0 to 3%, particularly preferably 0 to 2%. If the B ₂ O ₃ content is too _large, the less amount of precipitation of _{Li 2 O-Al 2 O 3} -SiO 2 based crystal, the desired linear thermal expansion coefficient is difficult to obtain.

P ₂ O ₅ is a component having an action of suppressing the coarsening of crystals. However, when there is too much the content, there exists a tendency for devitrification to become strong. Therefore, the content of P ₂ O ₅ is preferably 0 to 1%, particularly preferably 0 to 0.8%.

  In addition, it is preferable that the crystallized glass which comprises a crystallized glass article also has the said composition.

  By using a crystalline glass body to which a metal oxide powder or an inorganic pigment powder is adhered, a colored layer made of a metal oxide powder or an inorganic pigment powder is formed at the interface between the glass bodies fused to each other. You can make it appear.

  In this case, the addition amount of the metal oxide powder or the inorganic pigment powder is preferably 3 parts by mass or less, particularly preferably 1 part by mass or less with respect to 100 parts by mass of the crystalline glass body. If the amount of the metal oxide powder or inorganic pigment powder added is too large, the surface fluidity of the crystalline glass bodies will be hindered, and pores will remain at the interface of each glass body, resulting in insufficient fusion. There is a tendency that the mechanical strength of the crystallized glass article is inferior. Moreover, the surface roughness of the crystallized glass article tends to increase. Although it does not specifically limit about a minimum, In order to make a clear colored layer appear, it is preferable that it is 0.1 mass part or more, Especially 0.3 mass part or more.

  Examples of the metal oxide powder include cobalt oxide (blue), nickel oxide (green), iron oxide (brown), and vanadium oxide (yellow brown).

  Examples of inorganic pigment powders include zircon pigments such as Zr-Si-Fe (light reddish brown), Zr-Si-Pr (light yellow), Zr-Si-V (light blue); Zn-Cr-Ni-Al (brown ), Spinel pigments such as Al—Co—Zn (blue) and Fe—Cr—Zn (dark brown); and sphene pigments such as Sn—Si—Ca—Cr—Zn (pink).

  These metal oxide powders and inorganic pigment powders may be used alone or in combination of two or more.

  Moreover, the crystallized glass article by which a colored part is formed can be obtained by containing a coloring component within 5 mass% in at least one part of a crystalline glass body.

  The content of the coloring component is preferably 5% by mass or less, 3% by mass or less, particularly 1% by mass or less in the glass composition of the crystalline glass body. If the content of the coloring component is too large, the content of other components in the crystalline glass body is relatively reduced, and for example, the linear thermal expansion coefficient becomes too high due to a decrease in the amount of precipitated crystals. May have an impact. Although it does not specifically limit about a minimum, In order to acquire sufficient coloring effect, it is 0.01 mass% or more, It is preferable that it is 0.05 mass% or more especially.

  As the coloring component, cobalt oxide, nickel oxide, iron oxide, vanadium oxide, or the like is used. These may be used alone or in combination of two or more.

  In addition, when mixing and using the crystalline glass body containing a coloring component and the crystalline glass body which does not contain a coloring component in a glass composition, the mixing ratio is not specifically limited, The target crystallized glass article What is necessary is just to select suitably according to a pattern. For example, the ratio of (crystalline glass body containing a coloring component in the glass composition) :( crystalline glass body containing no coloring component in the glass composition) is 5:95 to 95: 5 in mass ratio. It is preferable that it is 10: 90-90: 10, especially 30: 70-70: 30.

  Next, the manufacturing method of the crystallized glass article of this invention is demonstrated.

  The crystallized glass article of the present invention is obtained by accumulating crystalline glass bodies in a refractory mold, heat-treating at a temperature equal to or higher than the softening point of the crystalline glass bodies, and fusing and integrating and crystallizing. Can be manufactured. Here, as the crystalline glass body, a glass body on which crystals have already partially precipitated may be used. In addition, as described above, after mixing and adhering the metal oxide powder or inorganic pigment powder to the crystalline glass body, the colored layer is formed at the interface of each glass body by accumulating in the refractory mold. The resulting crystallized glass article can be obtained.

  As a method for producing a crystalline glass body, for example, after melting raw material powder prepared so as to have a desired composition, the molten glass is poured into water and pulverized (thermally granulated) by thermal shock. Can be mentioned. Alternatively, a method in which glass obtained by molding molten glass into a plate shape (for example, a thickness of 5 mm or less) is pulverized by a mill made of alumina or the like and then classified by a sieve as necessary.

  The particle size and shape of the crystalline glass body are not particularly limited, and may be appropriately selected according to the pattern of the target crystallized glass article. However, if the particle size of the crystalline glass body is too large, it becomes difficult for each glass body to be fused and integrated, or pores remain at the interface of each glass body, reducing the mechanical strength of the crystallized glass article. Tend to. Moreover, it becomes difficult to mix uniformly with metal oxide powder or inorganic pigment powder, and it becomes difficult to obtain a desired pattern. On the other hand, when the particle size of the crystalline glass body is too small, handling becomes difficult, and it becomes difficult to obtain a desired pattern (for example, a spotted pattern) when mixed with a metal oxide powder or an inorganic pigment powder. Accordingly, the particle size of the crystalline glass body is preferably 0.1 to 8 mm, 0.2 to 4 mm, and particularly preferably 0.3 to 2 mm.

  Mixing of the crystalline glass and the metal oxide powder or the inorganic pigment powder can be performed by a known method using a V-type mixer, a concrete mixer or the like. A binder such as polyvinyl alcohol may be added as appropriate.

  The material of the refractory mold is not particularly limited as long as it has heat resistance equal to or higher than the firing temperature, and examples thereof include mullite cordierite, gypsum, SiC, and the like.

  In addition, it is preferable to accumulate the crystalline glass bodies after placing a release material such as a ceramic fiber sheet or an alumina sheet in the fireproof mold.

The firing temperature is preferably a temperature range above the softening point of the crystalline glass body, and in particular, the viscosity is from 10 ^4.5 to 10 ^5.5 poise (10 ^4.5 to 10 ^5.5 dPa · s). . Specifically, although it depends on the glass composition, the firing temperature is preferably 1000 ° C. or higher, particularly preferably 1100 ° C. or higher. If the firing temperature is too low, the surface smoothness of the crystallized glass article is lowered and the functionality and design tend to be inferior. On the other hand, considering the burden on the firing furnace and the fuel cost, the firing temperature is preferably 1200 ° C. or lower.

After maintaining at the firing temperature for a predetermined time, the crystallized glass article is obtained by cooling. Here, the cooling rate is preferably 300 ° C./hour or less, particularly preferably 200 ° C./hour or less. As a result, a predetermined amount of Li ₂ O—Al ₂ O ₃ —SiO ₂ crystal and RO—Al ₂ O ₃ —SiO ₂ crystal or R ′ ₂ O—Al ₂ O ₃ —SiO ₂ crystal were precipitated. Thus, a desired linear thermal expansion coefficient can be easily obtained.

  In addition, a baking furnace is not specifically limited, For example, a roller hearth kiln, a shuttle kiln, etc. are mentioned.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to these Examples.

(Examples 1-3)
(A) Production of crystalline glass article After melting glass raw materials prepared so as to have the respective glass compositions shown in Table 1 for 12 hours at a predetermined temperature, the molten glass was poured into water to obtain crystalline glass bodies. . The linear thermal expansion coefficient and glass transition point of the crystalline glass body were measured with a dilatometer (manufactured by Bruker AXS).

  After pulverizing the crystalline glass body, it was classified with a sieve to obtain a grainy crystalline glass body having a particle size of 0.5 to 2 mm. A predetermined amount of the inorganic pigment shown in Table 1 was added to the crystalline glass body, and a small amount of polyvinyl alcohol was added as a binder and mixed.

  A mullite cordierite formwork having an inner dimension of 600 mm × 800 mm × depth of 20 mm coated with alumina powder was placed on a shelf board made of mullite cordierite laid with alumina sheets. 10 kg of the crystalline glass particles with the inorganic pigment powder adhering to the surface were accumulated in the mold so that the height was uniform, and baked using a roller hearth kiln (gas furnace). As firing conditions, the temperature was raised at 300 ° C./hour, held at 1170 ° C. for 1 hour, cooled to 500 ° C. at 200 ° C./hour, and then cooled to room temperature. Thus, a crystallized glass article having a thickness of about 10 mm was obtained.

  In order to confirm the amount of precipitated crystals in the crystallized glass article, the following measurement was performed. After a part of the crystalline glass body was accumulated in a refractory container, crystallized glass was produced under the same firing conditions as described above. About the obtained crystallized glass, the amount of precipitated crystals was measured by a multiple peak separation method using an X-ray diffractometer manufactured by Rigaku. The results are shown in Table 1.

(B) Measurement of physical properties of crystallized glass article The following physical properties of the crystallized glass article were measured. The results are shown in Table 1.

  The linear thermal expansion coefficient and glass transition temperature were measured using a dilatometer.

  The heat resistance was evaluated as follows. The crystallized glass article processed into a predetermined shape was placed on a gas built-in stove (110-H551 type) manufactured by Herman. When a pan with a diameter of 250 mm is placed on the stove, when the high-calorie burner is heated at full power for 30 minutes, it is “passed” if it was not damaged, and “failed” if it was cracked. It was. Further, the generated stress in the crystallized glass article was obtained by performing a radiant heat transfer analysis by simulation using analysis software (ANSY: structural analysis).

  The bending strength was evaluated by a four-point bending strength according to ASTM C880-78.

Example 4
About the glass raw material prepared so that it might become the glass composition shown in Table 1, the grain-like crystalline glass body was produced by the method similar to Example 1. FIG. In this example, the particle size of the crystalline glass body was adjusted to 0.5 to 4 mm.

  A crystallized glass article was obtained by the same method as in Example 1 using only the obtained crystalline glass particles without adding metal oxide powder and inorganic pigment powder. In addition, in the grinding | polishing surface of the obtained crystallized glass article, the state which each glass body was mutually fuse | melted at the interface has been confirmed.

  About the obtained crystallized glass article, it carried out similarly to Example 1, and evaluated each physical property. The results are shown in Table 1.

(Comparative Example 1)
After the glass raw material prepared so as to have the glass composition shown in Table 1 was melted at a predetermined temperature for 12 hours, the molten glass was poured into water to obtain a crystalline glass body. The obtained crystalline glass body was classified with a sieve to obtain a grainy crystalline glass body having a particle size of 0.5 to 2.0 mm. Next, a predetermined amount of the inorganic pigment powder shown in Table 1 was added to 100 parts by mass of the crystalline glass body, and further, a small amount of binder was added and mixed well.

  A mullite cordierite formwork having an inner dimension of 450 mm × 650 mm × depth 20 mm coated with alumina powder was placed on a mullite cordierite shelf laid with alumina sheets. 5.6 kg of crystalline glass particles with inorganic pigment powder adhering to the surface were accumulated in a mold so that the height was uniform, and fired using a shuttle kiln. As firing conditions, the temperature was raised at 100 ° C./hour, held at 1100 ° C. for 1 hour, cooled to 500 ° C. at 100 ° C./hour, and then cooled to room temperature. Thus, a crystallized glass article having a thickness of about 10 mm was obtained.

  The physical properties of the obtained crystallized glass article were measured in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 2)
After the glass raw material prepared so as to have the glass composition shown in Table 1 was melted at a predetermined temperature for 12 hours, the molten glass was formed into a plate having a thickness of 5 mm with a roll.

  The obtained crystalline glass plate was placed on a mullite cordierite shelf coated with alumina powder and fired using a roller hearth kiln. As firing conditions, the temperature was raised at 100 ° C./hour, held at 1,070 ° C. for 1 hour, cooled to 500 ° C. at 100 ° C./hour, and then cooled to room temperature.

  The physical properties of the obtained crystallized glass article were measured in the same manner as in Example 1. The results are shown in Table 1.

  As is clear from Table 1, the crystallized glass articles of Examples 1 to 4 had good heat resistance and appropriate strength, and had excellent design properties. On the other hand, it can be seen that the crystallized glass articles of Comparative Examples 1 and 2 are particularly inferior in heat resistance, and are not suitable as members used under high temperature conditions such as a top plate for a cooker.

  The crystallized glass article of the present invention is particularly suitable as a cooking appliance top plate such as a gas stove top plate, a kitchen appliance top plate, a kitchen equipment decoration material such as a table top, a heating appliance component, and other various interior and exterior materials.

Claims (9)

A crystallized glass article obtained by accumulating crystalline glass bodies and fusion-integrated and crystallized by heat treatment, comprising 20 to 70% by mass of Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystal And RO—Al ₂ O ₃ —SiO ₂ based crystal (R = Mg, Ca, Sr, Ba) or R ′ ₂ O—Al ₂ O ₃ —SiO ₂ based crystal (R ′ = Na, K) is 1 A crystallized glass article comprising -75% by mass. The crystallized glass article according to claim 1, wherein a linear thermal expansion coefficient at 30 to 380 ° C. is 30 × 10 ⁻⁷ / K or less.   The crystallized glass article according to claim 1, comprising a β-spodumene solid solution and a potassium feldspar solid solution.   The crystallized glass article according to any one of claims 1 to 3, wherein an average grain size of the crystal is 0.5 µm or more. Crystalline glass masses is, as a glass composition, in _{mass%, SiO 2 55~72%, Al} 2 O 3 14~30%, Li 2 O 1.5~10%, Na 2 O 0~10%, K _{2 O 1~10%, TiO 2 0~3} %, ZrO 2 0~3%, 0~10% MgO, CaO 0~10%, SrO 0~10%, BaO 0~10%, ZnO 0~5% _{, B} 2 _{O 3} 0~3%, the crystallized glass article according to claim 1, characterized in that it contains _P 2 O 5 _0~1%.   6. A crystalline glass body obtained by adhering 0.1 to 3 parts by mass of metal oxide powder or inorganic pigment powder to 100 parts by mass of crystalline glass body is used. The crystallized glass article according to any one of the above.   The crystallized glass article according to any one of claims 1 to 6, wherein at least a part of the crystalline glass body contains 0.1 to 5% by mass of a coloring component in the glass composition.   The crystallized glass article according to any one of claims 1 to 7, wherein the crystallized glass article is used for a cooking appliance top plate, a kitchen equipment decoration material, or a heater component.   It is a method for manufacturing the crystallized glass article according to any one of claims 1 to 8, wherein the crystalline glass bodies are accumulated in a refractory mold, and the crystalline glass body has a softening point or higher. A manufacturing method comprising heat-treating at a temperature to fuse and integrate and crystallize.