TW201627246A - Glass powder, composite powder, and low expansion substrate with decorative layer - Google Patents

Abstract

The present invention addresses the technical problem of devising a glass powder and a composite powder which soften and become fluid at a low temperature, have a low coefficient of thermal expansion, and exhibit high water resistance and acid resistance. This glass powder is characterized by having a glass composition that contains, in terms of mol.%, 48-75% of SiO2, 5-23% of B2O3, 5-25% of Al2O3, 5-30% of Li2O, and 0-25% of ZnO, with the SiO2/B2O3 molar ratio being 3.23 or higher.

Description

Glass powder, composite powder and low expansion substrate with decorative layer

The present invention relates to a glass powder, a composite powder, and a low-expansion substrate with a decorative layer, and more particularly to a glass powder, a composite powder, and a decorative layer suitable for use in a top plate for a cooking appliance or the like including a decorative layer. Low expansion substrate.

Since the low-expansion crystallized glass substrate has high heating durability and thermal shock resistance, it is widely used as a top plate for cooking appliances.

Further, the surface of the top plate for the cooking utensil may be decorated by a decorative layer in order to enhance the aesthetic feeling. The decorative layer is generally a sintered body containing a composite powder of a glass powder and an inorganic pigment powder. For example, Patent Document 1 discloses a lead-free glass powder for forming a decorative layer, which is characterized by containing 55% to 70% of SiO ₂ and 15% to 25% of B ₂ O ₃ and 3 by mass%. % to 10% of Al ₂ O ₃ , 0.1% to 4.9% of BaO, 0.1% to 5% of ZnO, 0% to 3% of CaO, 0% to 3% of MgO, and 0.1% to 5% of Li ₂ O, 0% to 10% of Na ₂ O, 0.3% to 15% of K ₂ O, 0% to 2% of F ₂ , and a softening point of 600 ° C or more and less than 700 ° C.

A method of forming a decorative layer on the surface of a crystallized glass substrate is as follows. First, a glass powder is mixed with an inorganic pigment powder or the like to obtain a composite powder. Next, the obtained composite powder is dispersed in a medium containing an organic binder, a solvent, or the like, and paste-formed. Then, the obtained composite powder paste is transferred onto a crystallized glass substrate by a screen printing method or the like, dried, and then calcined by appropriate calcination conditions. When the composite powder is calcined, the composite powder (glass powder) is softened and then sintered. Thereby, the composite powder is strongly fixed to the crystallized glass substrate to form a decorative layer. [Prior Art Document] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2007-39294

[Problems to be solved by the invention]

However, the glass powder described in Patent Document 1 softens and flows at a low temperature, but has a high coefficient of thermal expansion, so that it is difficult to lower the thermal expansion coefficient of the decorative layer. When the coefficient of thermal expansion of the decorative layer is high, it becomes easy to cause cracks in the crystallized glass substrate with the decorative layer. The lower the thermal expansion coefficient of the crystallized glass substrate, the more easily this tendency becomes apparent. Further, the crack not only deteriorates characteristics such as water resistance and acid resistance, but also causes fouling inside of the crack and impairs the appearance.

Further, when the coefficient of thermal expansion of the decorative layer is high, excessive tensile stress is applied to the decorative layer, and the mechanical strength of the decorative layer is easily deteriorated due to an external force.

Moreover, the top plate for cooking utensils is exposed to hot water, juice, and seasonings during use. Therefore, the decorative layer is required to have high water resistance and acid resistance. Specifically, when the decorative layer is placed on the cooking surface side of the top plate of the cooking utensil, even when the decorative layer is disposed on the opposite side of the cooking surface, in order to perform the drilling process by the gas appliance or the like, it is required. High water resistance and acid resistance. Along with this, high water resistance and acid resistance are required for the glass powder.

The present invention has been made in view of the above-described problems, and a technical object thereof is to invent a glass powder and a composite powder which are softened and flowed at a low temperature and have a low thermal expansion coefficient and high water resistance and acid resistance. [Means for solving the problem]

As a result of various studies, the inventors have found that a predetermined amount of Li ₂ O is introduced into the SiO ₂ -B ₂ O ₃ -Al ₂ O ₃ -based glass powder, and the content of SiO ₂ is increased, and B ₂ O _{3 is also obtained.} The technical content is solved by reducing the content of the present invention, and the present invention has been proposed. That is, the glass powder of the present invention is characterized by containing 48% to 75% of SiO ₂ , 5% to 23% of B ₂ O ₃ , and 5% to 25% of Al ₂ O ₃ , in terms of mol%, 5% to 30% of Li ₂ O and 0% to 25% of ZnO are used as the glass composition, and the molar ratio of SiO ₂ /B ₂ O ₃ is 3.23 or more. Here, "SiO ₂ /B ₂ O ₃ " is a value obtained by dividing the content of SiO ₂ by the content of B ₂ O ₃ .

The glass powder of the present invention contains 48 mol% to 75 mol% of SiO ₂ , 5 mol% to 23 mol% of B ₂ O ₃ , and 5 mol% to 25 mol% of Al ₂ in the glass composition. O ₃ , 5 mol % to 30 mol % of Li ₂ O. Thereby, the low-expansion β-quartz solid solution can be precipitated after the flow is well softened at the time of calcination. As a result, both the softening fluidity and the low expansion coefficient can be considered.

On the other hand, when the content of SiO ₂ in the glass composition is lowered and the content of B ₂ O ₃ is increased, the softening fluidity of the glass powder is improved, but the water resistance of the glass matrix after precipitation of the β-quartz solid solution Acid resistance is easily reduced. Therefore, the glass powder of the present invention limits the molar ratio of SiO ₂ /B ₂ O ₃ in the glass composition to 3.23 or more. Thereby, the water resistance and acid resistance of the glass substrate after crystal precipitation can be improved, so that the water resistance and acid resistance of the decorative layer can be surely improved.

Second, the glass powder of the present invention preferably has a B ₂ O ₃ content of 16 mol% or less in the glass composition.

Third, the glass powder of the present invention preferably has a ZnO content of from 0.1 mol% to 7.6 mol% in the glass composition. If so, precipitation of the heterogeneous crystal can be suppressed at the time of calcination, and the precipitation amount of the β-quartz solid solution can be increased. As a result, the calcination temperature dependency of the thermal expansion coefficient can be lowered, and it is easy to prevent the strain stress from remaining locally after the calcination, and locally generate a state in which the thermal expansion coefficient is different. Moreover, it becomes easy to prevent a situation in which the coefficient of thermal expansion of the decorative layer differs between production lots.

Fourth, the glass powder of the present invention preferably further contains TiO ₂ and ZrO ₂ in a total amount of 0.1 mol% to 15 mol% in the glass composition.

Fifth, the glass powder of the present invention preferably contains substantially no PbO and Bi ₂ O ₃ in the glass composition. Here, the term "substantially does not contain ～" is a case where it is allowed to mix the impurity component with an impurity component, and specifically, the content of the component is less than 0.1% by mass.

Sixth, the glass powder of the present invention preferably has a coefficient of thermal expansion of 25 × 10 ^-7 / ° C or less after calcination at 700 ° C for 10 minutes. Here, the "thermal expansion coefficient" is a value measured in a temperature range of 30 ° C to 350 ° C using a thermomechanical analysis (TMA) apparatus. In addition, the measurement sample was densely sintered by calcination of the glass powder at 700 ° C for 10 minutes, and then processed into a predetermined shape.

Seventh, it is preferable that the glass powder of the present invention is calcined at 700 ° C for 10 minutes to precipitate a β-quartz solid solution as a main crystal. Here, "main crystal" means a crystal having the highest peak intensity when measured by an X-ray diffraction method.

Eighth, the glass powder of the present invention preferably has a softening point of from 550 ° C to 700 ° C as measured by a large differential thermal analysis (DTA) apparatus. Here, the softening point measured by the large DTA device means the temperature (Ts) of the fourth bending point shown in Fig. 1. Further, the measurement by the large DTA apparatus was carried out in the air, and the temperature increase rate was set to 10 ° C / min.

Ninth, the composite powder of the present invention is a composite powder containing 55 mass% to 100 mass% of glass powder, 0 mass% to 45 mass% of inorganic pigment powder, and 0 mass% to 40 mass% of refractory filler powder. Preferably, the glass powder is the glass powder.

Tenth, the composite powder of the present invention is preferably such that the inorganic pigment powder is a Cr-Cu composite oxide. Here, the "~ composite oxide" means a composite oxide containing an explicit component as an essential component.

Eleventh, the low-expansion substrate with a decorative layer of the present invention is a low-expansion substrate with a decorative layer containing a decorative layer on the surface of the low-expansion substrate, preferably the decorative layer is a sintered body of a composite powder, and the composite powder is The composite powder. Here, the "low expansion substrate" means a substrate having a thermal expansion coefficient of 35 × 10 ^-7 / ° C or less in a temperature range of 30 ° C to 350 ° C.

Twelfth, the low-expansion substrate with a decorative layer of the present invention is preferably subjected to decorative chromatography of a β-quartz solid solution.

Thirteenth, in the low-expansion substrate with a decorative layer of the present invention, it is preferable that the low-expansion substrate is a transparent crystallized glass substrate, and a β-quartz solid solution is precipitated as a main crystal.

Fourteenth, the low-expansion substrate with a decorative layer of the present invention preferably has a low-expansion substrate which is a quartz substrate.

Fifteenth, the decorative layered low expansion substrate of the present invention is preferably used in a top plate for cooking appliances.

The glass powder of the present invention is characterized by containing 48% to 75% of SiO ₂ , 5% to 23% of B ₂ O ₃ , 5% to 25% of Al ₂ O ₃ , and 5% by mol%. 30% of Li ₂ O and 0% to 25% of ZnO are used as the glass composition, and the molar ratio of SiO ₂ /B ₂ O ₃ is 3.23 or more. The reason for limiting the content range of each component as described above is as follows. In addition, in the description of the content range of each component, % means the mol%.

SiO ₂ is a component that forms a glass skeleton, and is a crystal constituent component of the β-quartz solid solution, and is a component that improves the water resistance and acid resistance of the glass matrix after crystal precipitation. The content of SiO ₂ is 48% to 75%, preferably 50% to 68%, 52% to 66%, 54% to 64%, particularly 56% to 62%. When the content of SiO ₂ is too small, the thermal stability is unreasonably lowered, and it becomes easy to precipitate crystals before the glass powder is sufficiently sintered. Further, it becomes difficult to precipitate a β-quartz solid solution at the time of calcination, and as a result, it is difficult to lower the thermal expansion coefficient of the decorative layer. Further, the water resistance and acid resistance of the glass substrate after crystallization are easily lowered. On the other hand, when the content of SiO ₂ is too large, the softening point is increased, and the softening fluidity of the glass powder is liable to lower.

B ₂ O ₃ is a component that forms a glass skeleton, and is a component that does not increase the coefficient of thermal expansion and lowers the softening point. The content of B ₂ O ₃ is 5% to 23%, preferably 7% to 19%, 9% to 16%, 10% to 14%, particularly 10% to 12%. When the content of B ₂ O ₃ is too small, the thermal stability is unreasonably lowered, and it becomes easy to precipitate crystals before the glass powder is sufficiently sintered. Further, the softening point is increased, and the softening fluidity of the glass powder is liable to lower. On the other hand, when the content of B ₂ O ₃ is too large, the water resistance and acid resistance of the glass substrate after crystal precipitation are likely to be lowered.

The molar ratio of SiO ₂ /B ₂ O ₃ is 3.23 or more, preferably 3.5 or more, 3.9 or more, 4.2 to 10, 4.5 to 8, 4.8 to 7, and particularly 5 to 6. When the molar ratio of SiO ₂ /B ₂ O _{3 is} too small, the water resistance and acid resistance of the glass substrate after crystallization are easily lowered, and the water resistance and acid resistance of the decorative layer are liable to lower. On the other hand, when the molar ratio of SiO ₂ /B ₂ O _{3 is} too large, a heterogeneous crystal such as β-spodumene is precipitated, and the amount of precipitation of the β-quartz solid solution is likely to be lowered.

Al ₂ O ₃ is a crystal constituent component of the β-quartz solid solution and is a component for improving acid resistance. The content of Al ₂ O ₃ is 5% to 25%, preferably 6% to 20%, 7% to 16%, 8% to 13%, particularly 9% to 11%. When the content of Al ₂ O ₃ is too small, it becomes difficult to precipitate a β-quartz solid solution at the time of firing, and as a result, it is difficult to lower the thermal expansion coefficient of the decorative layer. When the content of Al ₂ O ₃ is too large, the softening point increases, and the softening fluidity of the glass powder is liable to lower.

Li ₂ O is a crystal constituent component of the β-quartz solid solution, and is a component which does not increase the coefficient of thermal expansion and lowers the softening point. The content of Li ₂ O is 5% to 30%, preferably 7% to 25%, 10% to 22%, 12% to 20%, 13% to 18%, particularly 14% to 16%. When the content of Li ₂ O is too small, the softening point increases, and the softening fluidity of the glass powder is liable to lower. Further, it becomes difficult to precipitate a β-quartz solid solution at the time of firing, and as a result, it is difficult to lower the thermal expansion coefficient of the decorative layer. On the other hand, when the content of Li ₂ O is too large, the acid resistance is liable to lower.

ZnO is a component that does not cause a high coefficient of thermal expansion to lower the softening point. Moreover, it is a component which promotes crystallization. The content of ZnO is 0% to 25%, preferably 0% to 20%, 0% to 16%, 1% to 14%, 2% to 12%, 3% to 10%, particularly 4% to 7.6%. . Further, when it is desired to suppress the precipitation of the heterogeneous crystal and increase the precipitation amount of the β-quartz solid solution, the content of ZnO is 0.1% to 7.6%, 1% to 5%, particularly 1.5% to 3%. When the content of ZnO is too large, the water resistance and acid resistance of the glass substrate after crystallization are likely to be lowered, and the Li-Si-Zn-based heterogeneous crystal is easily precipitated, and the amount of precipitation of the β-quartz solid solution is easy. reduce.

In addition to the above components, for example, the following components may be introduced.

Na ₂ O and K ₂ O are components which lower the softening point. When the content is too large, it becomes difficult to precipitate a β-quartz solid solution at the time of firing, and as a result, it is difficult to lower the thermal expansion coefficient of the decorative layer. In addition, the acid resistance is easily lowered. Therefore, the total amount of Na ₂ O and K ₂ O is preferably 0% to less than 8%, 0% to 6%, 0% to 4%, 0% to 2%, particularly 0% to less than 1%. The content of Na ₂ O is preferably from 0% to less than 8%, from 0% to 6%, from 0% to 4%, from 0% to 2%, particularly from 0% to less than 1%. The content of K ₂ O is preferably from 0% to less than 8%, from 0% to 6%, from 0% to 4%, from 0% to 2%, particularly from 0% to less than 1%. The molar ratio of Li ₂ O/(Li ₂ O+Na ₂ O+K ₂ O) is preferably 0.5 or more, 0.6 or more, 0.7 or more, 0.8 or more, and particularly preferably 0.9 or more. Furthermore, _{"Li 2 O / (Li 2 O} + Na 2 O + K 2 O) " is divided by the content of Li ₂ O Li ₂ O, Na ₂ O and K ₂ O of the total amount of value.

TiO ₂ and ZrO ₂ are components which improve the crystallinity, and are components which improve the water resistance and acid resistance of the glass matrix after crystallization. However, if the content is too large, the softening point increases, and the softening fluidity of the glass powder becomes easy. reduce. Further, the thermal stability is unreasonably lowered, and it becomes easy to precipitate crystals before the glass powder is sufficiently sintered. The total amount of TiO ₂ and ZrO ₂ is preferably 0% to 15%, 0% to 12%, 0.1% to 10%, 1% to 8%, particularly 2% to 6%. The content of TiO ₂ is preferably 0% to 15%, 0% to 12%, 0.1% to 10%, 1% to 8%, particularly 2% to 6%. The content of ZrO ₂ is preferably 0% to 10%, 0% to 5%, 0% to less than 3%, 0% to 2%, particularly 0% to 1%.

MgO is a component that improves thermal stability. The content of MgO is preferably 0% to 7%, 0% to 5%, 0% to 3%, particularly 0% to 1%. When the content of MgO is too large, the softening point is increased, and the softening fluidity of the glass powder is liable to lower.

BaO is a component that improves thermal stability. The content of BaO is preferably from 0% to 7%, from 0% to 5%, particularly from 0.1% to 3%. When the content of BaO is too large, the coefficient of thermal expansion rises unreasonably, and it becomes difficult to lower the thermal expansion coefficient of the decorative layer.

CuO is a component for coloring glass to black. The content of CuO is preferably 0% to 7%, 0% to 5%, 0% to 3%, particularly 0% to 1%. When the content of CuO is too large, the thermal stability is unreasonably lowered, and it becomes easy to precipitate crystals before the glass powder is sufficiently sintered.

In addition to the ingredients, other ingredients such as 15%, 10%, 5%, and especially 1% may be introduced as needed. Specifically, for example, 15%, 10%, 5%, particularly 1% of CaO, SrO, Cr ₂ O ₃ , MnO, SnO ₂ , CeO ₂ , P ₂ O ₅ , La may be introduced in a metered manner or individually. ₂ O ₃ , Nd ₂ O ₃ , Co ₂ O ₃ , F, Cl, and the like.

Further, from the viewpoint of the environment, it is preferred that substantially no PbO is contained, and it is preferable that substantially no Bi ₂ O ₃ is contained.

The average particle diameter D _{50 of the} glass powder is preferably 15 μm or less, 0.5 μm to 10 μm, and particularly preferably 0.7 μm to 5 μm. If the particle size of the glass powder is too large, the screen printability is liable to lower, and the color tone of the decorative layer tends to be uneven. Here, the "average particle diameter D _{50 "} means a value measured by a laser diffraction device, and is expressed in a cumulative particle size distribution curve based on a volume basis when measured by a laser diffraction method. The amount of particle diameter accumulated from the small particle is 50% (the same applies hereinafter).

The softening point of the glass powder measured by the large DTA apparatus is preferably 550 ° C to 700 ° C, 570 ° C to 695 ° C, 590 ° C to 690 ° C, particularly 620 ° C to 685 ° C. The lower the softening point, the lower the calcination temperature and the higher the color rendering property of the inorganic pigment powder. However, if the softening point is too low, other properties, particularly the water resistance and acid resistance of the glass matrix after crystallization, are changed. It is easy to reduce. On the other hand, if the softening point is too high, the calcination temperature rises unreasonably, and the calcination cost increases rapidly.

The crystallization temperature of the glass powder measured by the large DTA apparatus is preferably 650 ° C to 750 ° C, 660 ° C to 740 ° C, and particularly 670 ° C to 730 ° C. When the crystallization temperature is too low, crystals are precipitated before the glass powder is sufficiently sintered at the time of firing, and the denseness of the decorative layer is liable to lower. On the other hand, when the crystallization temperature is too high, it becomes difficult to crystallize the crystal during the baking, and it becomes difficult to lower the thermal expansion coefficient of the decorative layer. Here, the crystallization temperature measured by the large DTA apparatus means the exothermic peak temperature (Tc) of the crystallization precipitation shown in FIG.

The sintered body after calcining the glass powder at 700 ° C for 10 minutes has a thermal expansion coefficient of preferably 25 × 10 ^-7 / ° C or less, 15 × 10 ^-7 / ° C or less, and 10 × 10 ^-7 / ° C or less. In particular, -10 × 10 ^-7 / ° C ~ 5 × 10 ^-7 / ° C. When the thermal expansion coefficient of the sintered body of the glass powder is too high, it becomes difficult to lower the thermal expansion coefficient of the decorative layer, and it is easy to cause cracks in the low-expansion substrate with the decorative layer. Further, it is also easy to cause peeling of the decorative layer or the like.

When the glass powder is calcined at 700 ° C for 10 minutes, it is preferred to precipitate a β-quartz solid solution as a main crystal. When the above is carried out, the coefficient of thermal expansion of the decorative layer is largely lowered, so that it is possible to reliably prevent the occurrence of cracks in the low-expansion substrate with the decorative layer.

The composite powder of the present invention contains at least a glass powder and an inorganic pigment powder, and if necessary, a refractory filler powder or the like. The glass powder is a component for dispersing the inorganic pigment powder and fixing it to the low-expansion substrate. The inorganic pigment powder is a component for coloring black or the like to improve the decorative property. The refractory filler powder is an optional component, a component that increases mechanical strength, and is a component for adjusting the coefficient of thermal expansion. Further, in addition to the above, in order to improve color rendering properties, a metal powder such as Cu powder may be added.

Preferably, the composite powder of the present invention contains 55% by mass to 100% by mass of glass powder, 0% by mass to 45% by mass of inorganic pigment powder, and 0% by mass to 40% by mass of refractory filler powder.

The content of the glass powder is preferably 55% by mass to 100% by mass, 55% by mass to 95% by mass, 55% by mass to 90% by mass, 55% by mass to 85% by mass, 60% by mass to 80% by mass, particularly 65. Mass% to 75% by mass. When the content of the glass powder is too small, the fixing property of the decorative layer and the low-expansion substrate is likely to be lowered. Further, when the content of the glass powder is too large, the relativeness of the inorganic pigment powder is small, and the decorative property of the decorative layer is liable to lower.

The content of the inorganic pigment powder is preferably from 0% by mass to 45% by mass, from 5% by mass to 45% by mass, from 10% by mass to 45% by mass, from 13% by mass to 45% by mass, particularly preferably from 15% by mass to 30% by mass. When the content of the inorganic pigment powder is too small, the decorative property is liable to lower. On the other hand, when the content of the inorganic pigment powder is too large, the relativeness of the glass powder is small, and the fixing property of the decorative layer and the low-expansion substrate is likely to be lowered. Further, when the content of the inorganic pigment powder is too large, the surface smoothness of the decorative layer is lowered, and the water resistance and acid resistance of the decorative layer are liable to lower.

Various inorganic pigment powders may be used, such as NiO (green), MnO ₂ (black), CoO (black), Fe ₂ O ₃ (tea brown), Cr ₂ O ₃ (green), TiO ₂ (white), and the like. Oxide, Cr-Al-based spinel (pink), Sn-Sb-V-based rutile (grey), Ti-Sb-Ni-based rutile (yellow), Zr-V-based oxyzircon (yellow), etc. Oxide, Co-Zn-Al-based spinel (blue), Zn-Fe-Cr-based spinel (brown), Cr-Cu-Mn-based spinel, etc., Ca-Cr-Si Garnet (Victoria Green), Ca-Sn-Si-Cr system vermiculite (pink), Zr-Si-Fe system zircon (orange-red), Co-Zn-Si-based strontium zincite (dark blue), Co-Si is an olivine such as olivine (dark blue) which is mixed in the above manner in such a manner that a desired color can be obtained. Further, in addition to the inorganic pigment powder, for example, an appropriate amount of ZrSiO ₄ or talc may be mixed in order to improve the concealability and abrasion resistance of the decorative layer.

The average particle diameter D _{50 of the} inorganic pigment powder is preferably 9 μm or less, and particularly preferably 0.5 μm to 4 μm. The maximum particle diameter D _{max of the} inorganic pigment powder is preferably 10 μm or less, and particularly preferably 2 μm to 8 μm. When the particle size of the inorganic pigment powder is too large, the screen printing property is liable to lower, and the color rendering property of the decorative layer is liable to lower.

The content of the refractory filler powder is preferably 0% by mass to 40% by mass, 0% by mass to 20% by mass, 0% by mass to 15% by mass, 0% by mass to 10% by mass, 0% by mass to 5% by mass, or less. The mass% to 1% by mass, particularly 0% by mass to less than 0.1% by mass. When the content of the refractory filler powder is too large, the fixing property of the decorative layer and the low-expansion substrate is likely to be lowered.

The refractory filler powder may be used with cordierite, strontium zincite, alumina, zirconium phosphate, zircon, zirconia, tin oxide, mullite, alumina, β-eucryptite, β-spodumene, β- Quartz solid solution, zirconium tungstate phosphate, and the like.

The composite powder of the present invention can be mixed with a vehicle and provided as a composite powder paste to be used. The vehicle mainly contains a solvent and a resin. A solvent can be added for the purpose of dissolving the resin and uniformly dispersing the composite powder. The resin is added for the purpose of adjusting the viscosity of the paste. Further, a surfactant, a tackifier, or the like may be added as needed.

As the resin, acrylate (acrylic resin), ethyl cellulose, polyethylene glycol derivative, nitrocellulose, polymethyl styrene, polyethylene carbonate, methacrylate or the like can be used. In particular, acrylate and ethyl cellulose are preferred because they have good thermal decomposition properties.

For the solvent, pine oil, N, N'-dimethylformamide (DMF), α-terpineol, higher alcohol, γ-butyrolactone (γ-BL), tetrahydrogen can be used. Naphthalene, butyl carbitol acetate, ethyl acetate, isoamyl acetate, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether acetate, benzyl alcohol, toluene, 3-methoxy-3- Methyl butanol, triethylene glycol monomethyl ether, triethylene glycol dimethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monobutyl ether, propylene carbonate, N-methyl-2-pyrrolidone and the like. In particular, α-terpineol is preferred because it has high viscosity and good solubility in resins and the like.

The composite powder paste can be produced, for example, by mixing the composite powder with a vehicle and uniformly kneading it by a three-roll mill.

The composite paste can be applied to a low-expansion substrate using a coater such as a screen printer, and then supplied to a drying step and a calcination step. Thereby, a decorative layer can be formed on the surface of the low expansion substrate. The conditions of the drying step are generally carried out at 70 ° C to 150 ° C for 10 minutes to 60 minutes. The calcination step is a step of decomposing and volatilizing the resin and sintering the composite powder to fix the decorative layer on the surface of the low-expansion substrate. The conditions of the calcination step are generally carried out at 650 ° C to 850 ° C for 5 minutes to 30 minutes. In the calcination step, the lower the calcination temperature, the more the production efficiency is improved, and the color rendering property of the inorganic pigment powder is improved, but on the other hand, the fixing property of the decorative layer and the low-expansion substrate is lowered.

The low-expansion substrate with a decorative layer of the present invention is a low-expansion substrate with a decorative layer containing a decorative layer on the surface of the low-expansion substrate, preferably the decorative layer is a sintered body of a composite powder, and the composite powder is the composite powder. The decorative layer-containing low-expansion substrate of the present invention contains the technical features of the composite powder of the present invention, but the contents thereof have been described, and thus the description thereof will be omitted for convenience.

Preferably, the low-expansion substrate with the decorative layer of the present invention is chromatographed to produce a β-quartz solid solution. When the above is carried out, the thermal expansion coefficient of the decorative layer is largely lowered, so that it is possible to reliably prevent the occurrence of cracks in the low-expansion substrate with the decorative layer.

In the low-expansion substrate with a decorative layer of the present invention, the low-expansion substrate is preferably a crystallized glass substrate (particularly a transparent crystallized glass substrate), and it is also preferred to precipitate a β-quartz solid solution as a main crystal. . When it is carried out as described above, the heating durability and the thermal shock resistance can be improved.

The coefficient of thermal expansion of the crystallized glass substrate is preferably -10 × 10 ^-7 / ° C to 30 × 10 ^-7 / ° C, particularly preferably - 5 × 10 ^-7 / ° C to 10 × 10 ^-7 / ° C. When the thermal expansion coefficient of the crystallized glass substrate is lowered, the heating durability and thermal shock resistance of the crystallized glass substrate are improved. As a result, it is preferable to use a top plate for a cooking appliance which is subjected to rapid thermal shock and rapid cooling during use. Further, the cooking apparatus includes an electromagnetic cooking appliance, an electric cooking appliance, a gas cooking appliance, and the like.

In the low-expansion substrate with a decorative layer of the present invention, the thickness of the decorative layer is preferably from 1 μm to 30 μm, particularly preferably from 2 μm to 10 μm. If the thickness of the decorative layer is too small, the pattern of decoration may become unclear. On the other hand, if the thickness of the decorative layer is too thick, the pattern of the decoration may be cracked. [Example 1]

Hereinafter, the present invention will be described based on examples. Furthermore, the following examples are merely illustrative. The present invention is not limited by the following examples.

Table 1 shows examples (sample No. 1 to sample No. 9) and comparative examples (sample No. 10, sample No. 11) of the present invention.

[Table 1]

First, the raw materials were prepared so as to have the glass composition described in the table, and the glass batch was uniformly mixed to obtain a glass batch, and then the glass batch was placed in a platinum crucible and melted at 1400 ° C for 3 hours. Thereafter, the molten glass is formed into a film shape. Then, the obtained glass film was pulverized by a ball mill, and then subjected to air classification to obtain a glass powder having an average particle diameter D ₅₀ of 2.5 μm.

For each glass powder, the softening point and the crystallization temperature were measured using a large DTA apparatus. Here, the measurement was performed in the air, and the temperature increase rate was set to 10 ° C / min. Further, the softening point means the temperature of the fourth bending point, and the crystallization temperature means the exothermic peak temperature at which crystals are precipitated.

The main crystal is a sample obtained by densely sintering a green compact of a glass powder at a temperature of 700 ° C for 10 minutes, and then processing it into a predetermined shape as a measurement sample, and measuring the peak intensity by an X-ray diffraction method. The largest crystallization.

The coefficient of thermal expansion of the glass powder is a value measured in a temperature range of 30 ° C to 350 ° C using a TMA apparatus. Here, the measurement sample was obtained by compactly sintering the green compact of the glass powder under calcination conditions at 700 ° C for 10 minutes, and then processing into a predetermined shape.

The water resistance of the glass powder was evaluated as follows. In other words, the powder compact of the glass powder is densely sintered at 700 ° C for 10 minutes, and then processed into a predetermined shape as a measurement sample, and immersed in water at 100 ° C (← correction, 90 ° C). When the hour was small, the case where no change in appearance was found was evaluated as "○", and the case where the change in appearance was found was evaluated as "x".

Next, the glass powder and the inorganic pigment powder were mixed at a ratio (total 100%) shown in the table to obtain a composite powder. Here, the inorganic pigment powder used was a Cr-Cu-Mn composite oxide (having an average particle diameter D ₅₀ of 1.5 μm and a maximum particle diameter D _max of 4.0 μm).

Further, the obtained composite powder was mixed with a vehicle, and then uniformly kneaded by a three-roll mill to obtain a composite powder paste. Further, the vehicle is prepared by dissolving ethyl cellulose in α-rosin, and the composite powder/agent is adjusted to 2 to 3 by mass ratio.

Then, the composite powder paste was screen-printed on a single-sided whole of a 10 cm square transparent crystallized glass substrate (N-0, main crystal: β-quartz solid solution manufactured by Nippon Electric Glass Co., Ltd.), and then After drying at 120 ° C for 20 minutes, it was placed in an electric furnace at 700 ° C, calcined for 10 minutes, and naturally cooled to room temperature, thereby obtaining a transparent crystallized glass with a decorative layer having a thickness of 10 μm. Substrate.

The presence or absence of the crack was observed for the transparent crystallized glass substrate with the decorative layer, and the case where no crack was found was evaluated as "○", and the case where the crack was found was evaluated as "x".

The wear resistance was measured by using #1000 sandpaper, and the decorative layer was subjected to 100 round trips at a speed of 1.3 kg and a single pass of 100 mm/sec, and the decorative layer was not peeled off as "○", and the decorative layer was peeled off. The situation is evaluated as "X".

When the water resistance of the decorative layer was immersed in water at 90 ° C for 24 hours, the appearance of the decorative layer was not evaluated as "○", and the change in appearance was slightly evaluated as "△", and the appearance change was clearly observed. The situation is evaluated as "X".

When the acid resistance of the decorative layer was immersed in a 0.1% by mass aqueous solution of HCl at 40 ° C for 1 hour, the appearance of the decorative layer was not evaluated as "○", and the change in appearance was slightly evaluated as "△". The case where the appearance change was clearly found was evaluated as "X".

According to Table 1, it was found that Sample No. 1 to Sample No. 9 had a low coefficient of thermal expansion, and the evaluation of water resistance and acid resistance was good. On the other hand, in sample No. 10, since the molar ratio of SiO ₂ /B ₂ O _{3 was} small, the evaluation of water resistance and acid resistance was poor. Further, Sample No. 11 did not precipitate crystals after calcination, and cracks were formed in the case of producing a transparent crystallized glass substrate with a decorative layer. [Embodiment 2]

Table 2 shows an example (sample No. 12 to sample No. 16) of the present invention.

[Table 2]

First, the raw materials were prepared so as to have the glass composition described in the table, and the glass batch was uniformly mixed to obtain a glass batch, and then the glass batch was placed in a platinum crucible and melted at 1400 ° C for 3 hours. Thereafter, the molten glass is formed into a film shape. Then, the obtained glass film was pulverized by a ball mill, and then subjected to air classification to obtain a glass powder having an average particle diameter D ₅₀ of 2.5 μm.

For each glass powder, the softening point and the crystallization temperature were measured using a large DTA apparatus. Here, the measurement was performed in the air, and the temperature increase rate was set to 10 ° C / min. Further, the softening point means the temperature of the fourth bending point, and the crystallization temperature means the exothermic peak temperature at which crystals are precipitated.

The main crystal is a sample obtained by densely sintering a green compact of a glass powder at a temperature of 700 ° C for 10 minutes, and then processing it into a predetermined shape as a measurement sample, and measuring the peak intensity by an X-ray diffraction method. The largest crystallization. In the sample No. 11 to the sample No. 15, the amount of precipitation of the β-quartz solid solution of the sample No. 15 was the largest, and the amount of precipitation of the heterogeneous crystal (β-spodumene) was the smallest.

The coefficient of thermal expansion of the glass powder is a value measured in a temperature range of 30 ° C to 350 ° C using a TMA apparatus. Here, the measurement sample is densely sintered by using the green compact of the glass powder under the calcination conditions in the table, and then processed into a predetermined shape.

The water resistance of the glass powder was evaluated as follows. In other words, the powder compact of the glass powder is densely sintered at 700 ° C for 10 minutes, and then processed into a predetermined shape as a measurement sample. When immersed in water at 90 ° C for 2 hours, no appearance is observed. The change was evaluated as "○", and the change in appearance was evaluated as "x".

Next, the glass powder and the inorganic pigment powder were mixed at a ratio (total 100%) shown in the table to obtain a composite powder. Here, the inorganic pigment powder used was a Cr-Cu-Mn composite oxide (having an average particle diameter D ₅₀ of 1.5 μm and a maximum particle diameter D _max of 4.0 μm).

Further, the obtained composite powder was mixed with a vehicle, and then uniformly kneaded by a three-roll mill to obtain a composite powder paste. Further, the vehicle is prepared by dissolving ethyl cellulose in α-rosin, and the composite powder/agent is adjusted to 2 to 3 by mass ratio.

Then, the composite powder paste was screen-printed on a single-sided whole of a 10 cm square transparent crystallized glass substrate (N-0, main crystal: β-quartz solid solution manufactured by Nippon Electric Glass Co., Ltd.), and then After drying at 120 ° C for 20 minutes, it was placed in an electric furnace at 700 ° C, calcined for 10 minutes, and naturally cooled to room temperature, thereby obtaining a transparent crystallized glass with a decorative layer having a thickness of 10 μm. Substrate.

The presence or absence of the crack was observed for the transparent crystallized glass substrate with the decorative layer, and the case where no crack was found was evaluated as "○", and the case where the crack was found was evaluated as "x".

The wear resistance was measured by using #1000 sandpaper, and the decorative layer was subjected to 100 round trips at a speed of 1.3 kg and a single pass of 100 mm/sec, and the decorative layer was not peeled off as "○", and the decorative layer was peeled off. The situation is evaluated as "X".

When the water resistance of the decorative layer was immersed in water at 90 ° C for 24 hours, the appearance of the decorative layer was not evaluated as "○", and the change in appearance was slightly evaluated as "△", and the appearance change was clearly observed. The situation is evaluated as "X".

When the acid resistance of the decorative layer was immersed in a 0.1% by mass aqueous solution of HCl at 40 ° C for 1 hour, the appearance of the decorative layer was not evaluated as "○", and the change in appearance was slightly evaluated as "△". The case where the appearance change was clearly found was evaluated as "X".

According to Table 2, the sample No. 11 to sample No. 15 had a low coefficient of thermal expansion, and the evaluation of water resistance and acid resistance was good. In particular, Sample No. 11, Sample No. 13, and Sample No. 15 contained ZnO in a small amount in the glass composition. Therefore, even if the firing temperature fluctuated, the fluctuation range of the thermal expansion coefficient was small. That is, the calcination temperature dependence of the coefficient of thermal expansion is small. [Industrial availability]

The glass powder, the composite powder, and the low-expansion substrate with a decorative layer of the present invention can be suitably used for a top plate for a cooking utensil including a decorative layer, or can be applied to a coating of a low-expansion substrate such as a quartz substrate or a Si ₃ N ₄ substrate. , sealing and other uses. In addition, when the composite powder of the present invention is used in applications such as sealing and coating, the inorganic pigment powder may not be introduced, and instead of increasing the mechanical strength, 0.1% by mass or more of the refractory filler powder may be introduced.

no

Fig. 1 is a graph showing a softening point and a crystallization temperature measured by a large DTA apparatus.

no

Claims (15)

A glass powder characterized by containing 48% to 75% of SiO ₂ , 5% to 23% of B ₂ O ₃ , 5% to 25% of Al ₂ O ₃ , and 5% to 30% by mol% % of Li ₂ O and 0% to 25% of ZnO are used as the glass composition, and the molar ratio of SiO ₂ /B ₂ O ₃ is 3.23 or more. The glass powder according to claim 1, wherein the content of B ₂ O ₃ in the glass composition is 16 mol% or less. The glass powder according to claim 1 or 2, wherein the content of ZnO in the glass composition is from 0.1 mol% to 7.6 mol%. The glass powder according to any one of claims 1 to 3, wherein the glass composition further contains TiO ₂ and ZrO ₂ in a total amount of 0.1 mol% to 15 mol%. The glass powder according to any one of claims 1 to 4, wherein the glass composition substantially does not contain PbO and Bi ₂ O ₃ . The glass powder according to any one of the items 1 to 5, wherein the thermal expansion coefficient after calcination at 700 ° C for 10 minutes is 25 × 10 ^-7 / ° C or less. The glass powder according to any one of the above-mentioned items, wherein the glass powder is subjected to calcination at 700 ° C for 10 minutes to precipitate a β-quartz solid solution as a main crystal. The glass powder according to any one of claims 1 to 7, wherein the softening point measured by a large-scale differential thermal analyzer is 550 ° C to 700 ° C. A composite powder which is a composite powder containing 55% by mass to 100% by mass of glass powder, 0% by mass to 45% by mass of inorganic pigment powder, and 0% by mass to 40% by mass of refractory filler powder, characterized in that: The glass powder is the glass powder according to any one of the items 1 to 8. The composite powder according to claim 9, wherein the inorganic pigment powder is a Cr-Cu composite oxide. A low-expansion substrate with a decorative layer, which is a decorative layer-containing low-expansion substrate comprising a decorative layer on a surface of a low-expansion substrate, characterized in that: the decorative layer is a sintered body of a composite powder, and the composite powder is as claimed in the patent application. The composite powder according to item 9 or item 10. The low-expansion substrate with a decorative layer according to the invention of claim 11, wherein the β-quartz solid solution is chromatographed in the decoration. The low-expansion substrate with a decorative layer according to claim 11 or 12, wherein the low-expansion substrate is a transparent crystallized glass substrate, and a β-quartz solid solution is precipitated as a main crystal. The low-expansion substrate with a decorative layer according to claim 11 or 12, wherein the low-expansion substrate is a quartz substrate. The low-expansion substrate with a decorative layer according to any one of claims 11 to 13, which is used in a top plate for cooking appliances.