WO2018198968A1 - Glass ceramic composite for chemical strengthening, chemically strengthened glass ceramic composite, and method for producing same - Google Patents

Abstract

Provided are: a glass ceramic composite for chemical strengthening, said glass ceramic composite having exceptional machinability and being capable of imparting high strength; a chemically strengthened glass ceramic composite in which the glass ceramic composite is used; and a method for producing the chemically strengthened glass ceramic composite. A glass ceramic composite for chemical strengthening obtained by dispersing mica powder in a glass matrix, wherein, in the glass ceramic composite for chemical strengthening, the glass that constitutes the glass matrix includes the following, expressed in terms of the molar percentage of oxides: 40 to 65% of SiO2, more than 8.0% to no more than 21.0% of Al2O3, more than 5% to 40% of B2O3, a total of 5 to 23% of one or more species selected from Li2O and Na2O, and 0 to less than 2% of an alkaline earth metal oxide.

Description

Chemically strengthened glass-ceramic composite, chemically strengthened glass-ceramic composite, and manufacturing method thereof

The present invention relates to a chemically strengthened glass ceramic composite, a chemically strengthened glass ceramic composite, and a method for producing the same.

2. Description of the Related Art A glass ceramic substrate made of a sintered body of a composition containing glass powder and ceramic powder is known as a wiring substrate used in electronic equipment. A glass ceramic substrate is used by being mounted on an electronic device as a wiring substrate by forming a conductive pattern on the surface or inside, for example. Alternatively, a glass ceramic substrate may be used as a housing for an electronic device such as a mobile phone without being particularly wired.

In recent years, with the downsizing and higher functionality of electronic devices, glass ceramic substrates are also required to be thinner. Furthermore, since the electrode structure is complicated with the complexity and miniaturization of the circuit board, the stress applied to the glass ceramic substrate is also increased. For this reason, a glass ceramic substrate having higher strength than before has been demanded.

For example, in Patent Document 1, for the purpose of increasing the strength of a glass ceramic substrate, flat alumina particles having an aspect ratio of 3 or more are dispersed in a glass matrix, and the thermal expansion coefficient of the inner layer portion of the glass ceramic substrate is determined as the surface layer. There has been proposed a glass ceramic substrate larger than the portion.

Here, when the glass ceramic substrate is used for a housing for an electronic device or the like, it may be subjected to machining such as providing a hole with a drill. Therefore, a glass ceramic substrate having excellent machinability is demanded.

However, the glass-ceramic substrate is a brittle material for both glass and ceramics, which are the main components, and is inherently vulnerable to impacts and easily cracks. Therefore, conventionally, attempts have been made to improve the machinability of a glass ceramic substrate by mixing mica with glass having a predetermined composition (see, for example, Patent Documents 2 and 3).

International Publication No. 2014/073604 JP 2005-97016 A Special table 2011-525471 gazette

However, a glass ceramic substrate having both high strength characteristics and excellent machinability as required in recent years has not been known.

The present invention has been made in order to solve the above-described problems, and has excellent machinability and can impart high strength, a glass-ceramic composite for chemical strengthening, and chemical strengthening using the same An object of the present invention is to provide a glass ceramic composite and a method for producing the same.

The glass-ceramic composite for chemical strengthening of the present invention is a glass-ceramic composite for chemical strengthening in which mica powder is dispersed in a glass matrix, and the glass constituting the glass matrix is a mol% in terms of oxide. SiO ₂ is 40 to 65%, Al ₂ O ₃ is more than 8.0% and 21.0% or less, B ₂ O ₃ is more than 5% and 40% or less, 1 selected from Li ₂ O and Na ₂ O 5 to 23% in total of seeds or more and 0 to less than 2% of alkaline earth metal oxide.

In the glass-ceramic composite for chemical strengthening of the present invention, Li ₂ O and Na ₂ O in the glass preferably have a Li ₂ O / Na ₂ O ratio of 0.35 to 4.

In the glass-ceramic composite for chemical strengthening of the present invention, it is preferable that B ₂ O ₃ and SiO ₂ in the glass have a SiO ₂ / B ₂ O ₃ ratio of 1 to 13.

The glass-ceramic composite for chemical strengthening of the present invention preferably contains 15 to 50% by volume of mica powder with respect to the total volume of the glass-ceramic composite for chemical strengthening.

In the glass-ceramic composite for chemical strengthening of the present invention, the glass matrix preferably has a crystallinity of 15% or less.

The chemical-strengthening glass ceramic composite of the present invention preferably further contains a colored inorganic pigment.

The glass-ceramic composite for chemical strengthening of the present invention preferably has an infrared transmittance of 0.001% or less at a wavelength of 600 to 1000 nm when the thickness is 1 mm.

The glass-ceramic composite for chemical strengthening of the present invention is plate-like and preferably machined.

The chemically strengthened glass ceramic composite of the present invention is a chemically strengthened glass ceramic composite that has been subjected to a chemical strengthening treatment, wherein mica powder is dispersed in a glass matrix, and the glass constituting the glass matrix is As an average composition of the glass matrix, SiO ₂ is 40 to 65%, Al ₂ O ₃ is more than 8.0% and less than 21.0%, and B ₂ O ₃ is more than 5% in terms of mol% in terms of oxide. % Or less, 5 to 23% in total of at least one selected from Li ₂ O, Na ₂ O and K ₂ O, and 0 to less than 2% of alkaline earth metal oxide.

The chemically tempered glass-ceramic composite of the present invention has at least one selected from Li ₂ O, 0 to 6%, K ₂ O, and Na ₂ O as an average composition from the surface to 30 μm in terms of mol% in terms of oxide. It is preferable to contain 8 to 23% in total.

In the chemically strengthened glass-ceramic composite of the present invention, the three-point bending strength measured by a method in accordance with JIS C2141 is preferably 1.2 or more, with 1 before chemical strengthening.

The method for producing a chemically strengthened glass-ceramic composite according to the present invention includes glass particles and mica powder, and the content of the mica powder is 15 to 50% by volume with respect to the total of the glass particles and the mica powder. The particles are in mol% in terms of oxide, SiO ₂ is 40 to 65%, Al ₂ O ₃ is more than 8.0% and 21.0% or less, B ₂ O ₃ is more than 5% and 40% or less, Li ₂ A step of obtaining a glass-ceramic composite for chemical strengthening by sintering a glass-ceramic composition containing 5 to 23% in total of one or more of O and Na ₂ O and 0 to less than 2% of alkaline earth metal oxide And a step of obtaining a chemically strengthened glass-ceramic composite that has been chemically strengthened by subjecting the glass-ceramic composite for chemical strengthening to chemical strengthening.

In the method for producing a chemically strengthened glass-ceramic composite according to the present invention, it is preferable that the chemically strengthened glass-ceramic composite has a plate shape and includes a step of machining the chemically strengthened glass-ceramic composite.

In the present specification, the sign “˜” represents a range including the numerical value on the left as the lower limit and the numerical value on the right as the upper limit.

According to the glass-ceramic composite for chemical strengthening of the present invention, it has excellent machinability and can impart high strength to the chemically strengthened glass-ceramic composite.
According to the method for producing a chemically strengthened glass ceramic composite of the present invention, it is excellent in machinability and can impart high strength to the chemically strengthened glass ceramic composite.

Hereinafter, embodiments will be described in detail.
<Glass ceramic composite for chemical strengthening>
The glass-ceramic composite for chemical strengthening according to this embodiment is a glass-ceramic composite for chemical strengthening in which mica powder is dispersed in a glass matrix. In the glass-ceramic composite for chemical strengthening of the present embodiment, the glass constituting the glass matrix is SiO _{2 in an amount} of 40 to 65% and Al ₂ O ₃ in excess of 8.0% and 21. 0% or less, B ₂ O ₃ in excess of 5% to 40% or less, one or more selected from Li ₂ O and Na ₂ O in total 5 to 23%, alkaline earth metal oxides 0 to less than 2% Including.

The glass-ceramic composite for chemical strengthening of the present embodiment can be obtained, for example, by firing a glass ceramic composition in which glass powder having the above composition and mica powder are mixed. At this time, the glass particles contained in the glass ceramic composition are melted during firing, and the mica powder is dispersed in the molten glass. Thereby, a glass-ceramic composite for chemical strengthening in which mica powder is dispersed in a glass matrix is obtained.

The glass-ceramic composite for chemical strengthening according to the present embodiment has excellent machinability, in which cracking and chipping (chipping) are hardly caused in machining such as cutting by dispersing mica powder in a glass matrix. Have. In addition, the chemically strengthened glass-ceramic composite of this embodiment can be subjected to a chemical strengthening treatment, whereby a high-strength chemically strengthened glass-ceramic composite can be obtained.

Furthermore, the chemical strengthening glass-ceramic composite or the chemically strengthened glass-ceramic composite of the present embodiment can be adjusted in various properties depending on the composition of the raw glass powder and the ceramic composition. For example, physical properties such as density, bending strength, scratch resistance, impact resistance, fracture toughness, mechanical properties such as Vickers hardness, Young's modulus, color tone, light transmission characteristics, light reflection characteristics, gloss, light resistance, etc. Optical characteristics, dielectric constant, dielectric loss, radio wave transmission, insulation characteristics, electrical characteristics, thermal expansion coefficient, heat resistance, thermal conductivity, and other thermal characteristics, chemical resistance, weather resistance, antifouling, surface Chemical properties such as adsorption and adhesion can be adjusted.

The chemically strengthened glass-ceramic composite or the chemically strengthened glass-ceramic composite of the present embodiment has the above-mentioned preferable characteristics. For example, an electronic portable terminal, a medical device, a watch, a display device, a cosmetic case, an automobile interior part, It can be effectively used as a structural material for various devices such as horticultural materials, dental materials, and glasses (a structural material such as a main component member or a partial component member of the device).
Further, the chemically strengthened glass-ceramic composite or the chemically strengthened glass-ceramic composite of the present embodiment is, for example, lighter and higher in weight than a light metal such as general aluminum or titanium or an alloy thereof or general ceramics. It can have strength, gloss, high machinability and the like.

Hereinafter, each component contained in the glass ceramic composite for chemical strengthening of the present embodiment will be described.

(Mica powder)
The mica powder imparts excellent machinability to the chemically strengthened glass ceramic composite while maintaining the strength of the chemically strengthened glass ceramic composite. The mica powder is obtained by molding synthetic mica or natural mica into a powder form by pulverization or the like.

Mica is a kind of silicate mineral and is also called mica. The chemical composition of mica is represented by IM _2-3 T ₄ O ₁₀ A ₂ . I is K, Na, Ca, Ba, Rb, Cs, NH ₄ or the like, and M is Al, Mg, Fe, Li, Ti, Mn, Cr, Zn, V, or the like. T is Si, Al, Fe (trivalent), Be, B or the like, and A is OH, F, Cl, O, S or the like.

In the chemically strengthened glass-ceramic composite of this embodiment, as mica, fluorine phlogopite (KMg ₃ AlSi ₃ O ₁₀ F ₂ ), potassium tetrasilicon mica (KMg _2.5 Si ₄ O ₁₀ F ₂ ), sodium tetra mica _{(NaMg 2.5 Si 4 O 10 F} 2), sodium hectorite _{(Na 0.33 Mg 2.67 Li 0.33 Si} 4 O 10 F 2) are preferred. Specific gravity (g / mL) is usually about 2.85 for fluorophlogopite and about 2.65 for tetrasilicon mica. Examples of commercially available products of fluorophlogopite include Micromica MK series (manufacturer: Katakura Corp. Agri Co., Ltd.), PDM series (manufacturer: Topy Industries, Ltd.), and the like.

In addition to mica powder, talc and clay-based layered compound particles are also suitable for imparting machinability. However, by using mica powder, the mica The particle size and the like can be kept at an initial state without melting or decomposing the powder into glass. From the viewpoint of keeping the mica powder in the glass-ceramic composite for chemical strengthening in an initial state, it is more preferable that the mica powder does not have crystal water so as not to generate gas during sintering.

¡The smaller the mica powder particle size, the smaller the chipping size during machining. Therefore, the average particle diameter (D50) of the mica powder is preferably 15 μm or less and more preferably 8 μm or less in terms of improving machinability. The D50 of the mica powder is preferably 1 μm or more and more preferably 2 μm or more because it is difficult to impair workability. In addition, D50 shown in this specification is a 50% average particle diameter in terms of volume obtained by a particle diameter measuring apparatus (manufactured by Nikkiso Co., Ltd., trade name: MT3100II) by a laser diffraction / scattering method.

(Glass powder)
Next, each component of the glass powder in the glass ceramic composition used in the present embodiment will be described. In the description of the glass composition, “%” represents an oxide-converted mol% unless otherwise specified.

SiO ₂ serves as a glass network former and is an essential component for increasing chemical durability, particularly acid resistance. If the content of SiO ₂ is 40% or more, sufficient acid resistance is ensured. On the other hand, if the content of SiO ₂ is 65% or less, the softening point (hereinafter referred to as “Ts”) and the glass transition point (hereinafter referred to as “Tg”) of the glass are excessively increased. It is adjusted to an appropriate range. The content of SiO ₂ is preferably 43% or more, more preferably 45% or more, and further preferably 48% or more. Further, the content of SiO ₂ is preferably 63% or less, more preferably 60% or less, and still more preferably 57% or less.

Al ₂ O ₃ is a component blended to increase the stability and chemical durability of the glass. In particular, it is an effective component for improving the strength when chemically strengthened, and is an essential component. Since the content of Al ₂ O ₃ is more than 8%, the strength improvement effect in the chemical strengthening treatment is sufficiently exhibited. On the other hand, since the content of Al ₂ O ₃ is 21% or less, a stable glass is obtained, and the glass is adjusted to an appropriate range without excessively increasing the softening point or glass transition point of the glass. The content of Al ₂ O ₃ is preferably 9% or more. Further, the content of Al ₂ O ₃ is preferably 19% or less, more preferably 17% or less.

B ₂ O ₃ serves as a glass network former, and is an essential component particularly for increasing the sinterability of glass powder. Since the content of B ₂ O ₃ exceeds 5%, Ts is adjusted to an appropriate range without excessively increasing, and the sinterability of the glass powder is sufficiently maintained. On the other hand, since the content of B ₂ O ₃ is 40% or less, a stable glass is obtained and the chemical durability is sufficiently ensured. The content of B ₂ O ₃ is preferably 10% or more, more preferably 15% or more. Further, the content of B ₂ O ₃ is preferably 30% or less, more preferably 25% or less.

Both Li ₂ O and Na ₂ O are components that lower the high temperature viscosity of the glass and are responsible for ion exchange in the chemical strengthening treatment, and are essential components. Since one or more selected from Li ₂ O and Na ₂ O is contained in a total of 5% or more, Ts is adjusted to an appropriate range without excessively increasing, and the sinterability of the glass powder is sufficiently maintained. The strength improvement effect by the chemical strengthening treatment is sufficiently exhibited. On the other hand, containing 23% or less of one or more in total selected from Li 2 _O and Na 2 _O, stable glass is obtained, the chemical durability is sufficiently secured. The total content of one or more selected from Li ₂ O and Na ₂ O in the glass is preferably 7% or more, and more preferably 10% or more. Further, the total content of one or more selected from Li ₂ O and Na ₂ O in the glass is preferably 19% or less, more preferably 17% or less, and even more preferably 15% or less.

In order to obtain a dense sintered body, it is important to suppress crystallization in the process of pulverizing, firing and sintering glass. The amount ratio of Li ₂ O and Na ₂ O is effective for controlling crystallization, and the molar ratio of Li ₂ O / Na ₂ O is preferably 0.35 to 4. When the molar ratio of Li ₂ O / Na ₂ O is an amount that satisfies the above molar ratio, glass stabilization is further promoted, and crystallization is suppressed during firing. The molar ratio of Li ₂ O / Na ₂ O is more preferably 0.5 or more, further preferably 0.8 or more, still more preferably 1 or more, particularly preferably 1.5 or more, and most preferably 2 or more. Further, the molar ratio of Li ₂ O / Na ₂ O is more preferably 3.5 or less, and further preferably 3 or less.

Further, the amount ratio of SiO ₂ and B ₂ O ₃ is also effective for controlling both the improvement of the sinterability and the chemical durability of the glass in the process of forming the glass into a powder and molding it. The molar ratio of SiO ₂ / B ₂ O ₃ is preferably 1-13. When the molar ratio of SiO ₂ / B ₂ O ₃ is an amount that satisfies the above molar ratio, both sinterability and chemical durability can be further achieved. The molar ratio of SiO ₂ / B ₂ O ₃ is more preferably 10 or less, further preferably 8 or less, and particularly preferably 5 or less.

In the present glass composition, alkaline earth metal oxides such as MgO, CaO, SrO and BaO promote crystallization and obtain a dense sintered body in the process of powdering, firing and sintering the glass. Becomes difficult. Further, since the glass is made brittle, chipping during machining such as cutting is promoted and bending strength is also lowered. Furthermore, the ion exchange at the time of chemical strengthening treatment is suppressed, and the strength improvement effect at the time of chemical strengthening is suppressed. For these reasons, the alkaline earth metal oxide is less than 2%. The alkaline earth metal oxide is preferably 1.5% or less, more preferably 1% or less, and further preferably 0.5% or less.

In addition, a glass composition is not necessarily limited to what consists only of the said component, Other components can be contained in the range with which various characteristics, such as Ts and Tg, are satisfy | filled. When other components are contained, the total content is preferably 10% or less. Specific examples of other components include ZrO ₂ . The total content of other components is more preferably 8% or less, further preferably 5% or less, and particularly preferably 3% or less.

The glass particles used in the present invention are prepared by mixing glass raw materials so as to be glass as described above, mixing them, producing glass by a melting method, and grinding the obtained glass by a dry grinding method or a wet grinding method. It is obtained by. In the case of the wet pulverization method, it is preferable to use water or ethyl alcohol as a solvent. The pulverization may be performed using a pulverizer such as a roll mill, a ball mill, or a jet mill.

The average particle diameter (D50) of the glass particles is preferably 0.5 to 2 μm. When the D50 of the glass particles is 0.5 μm or more, the glass particles are difficult to aggregate and are easy to handle, and are easily dispersed uniformly. On the other hand, when the D50 of the glass particles is 2 μm or less, an increase in Ts and occurrence of insufficient sintering can be suppressed. D50 may be classified and adjusted as necessary after grinding, for example.

(Glass ceramic composition)
The glass ceramic composition used for obtaining the glass-ceramic composite for chemical strengthening of the present embodiment contains the above-described mica powder and glass particles. Further, the glass ceramic composition may contain a filler other than mica powder as long as the effects of the present invention are not impaired.

The content of mica powder is preferably 15 to 50% by volume with respect to the total volume of the glass ceramic composition. When the content of the mica powder is 15% by volume or more, good machinability can be imparted to the glass-ceramic composite for chemical strengthening. On the other hand, when the content is 50% by volume or less, the glass ceramic composition is easily sintered, and a dense sintered body can be formed. As will be described later, the content of mica powder in the chemically strengthened glass-ceramic composite can be equated with the content of mica powder in the glass-ceramic composition. The content of mica powder is more preferably 20% by volume or more, and more preferably 45% by volume or less.

The glass ceramic composition used in the present embodiment may contain a filler other than mica powder in accordance with the use of the obtained glass ceramic composite for chemical strengthening within a range not impairing the effects of the present invention. . Examples of the filler include ceramic particles other than mica powder and colored inorganic pigments.

Specific examples of ceramic particles other than mica powder include silica, zirconia, titania, magnesia, mullite, aluminum nitride, regardless of the shape of flat alumina particles, powdered alumina particles, flat shapes, powders (irregular shapes), etc. And ceramic particles composed of silicon nitride, silicon carbide, forsterite, cordierite, and the like. Among these, powdery alumina particles are preferable in that the sinterability can be improved, the surface can be easily damaged, and the bending strength of the glass-ceramic composite can be improved.

The amount of the ceramic particles other than the mica powder in the glass ceramic composition may be an amount that does not impair the effects of the present invention, specifically, an amount of 35% by volume or less with respect to the total amount of the glass ceramic composition. 25 volume% or less is more preferable, 20 volume% or less is more preferable, and 15 volume% or less is particularly preferable.

As the ceramic particles other than the mica powder in the glass ceramic composition, powdery alumina particles are preferable for imparting scratch resistance. Furthermore, in order to give a deep color tone and a highly transparent appearance, ceramic particles having a refractive index close to that of the glass powder in the glass ceramic composition are preferable, and powdered alumina particles are preferable.

When powdered alumina particles are used as ceramic particles other than mica powder, the D50 of the powdered alumina particles is preferably 0.05 to 5 μm. When D50 is 0.05 μm or more, the dispersibility becomes good, so that excellent strength can be imparted to the glass-ceramic composite for chemical strengthening. Further, scratch resistance can be effectively imparted. Moreover, when D50 of a powdery alumina particle is 5 micrometers or less, uniform intensity | strength is obtained as the whole glass ceramic composite for chemical strengthening, and it is excellent in workability. The D50 of the powdered alumina particles is more preferably 0.1 μm or more, and further preferably 0.2 μm or more. Further, D50 is more preferably 3 μm or less, and further preferably 2 μm or less.

Examples of the colored inorganic pigment include metal oxides, particularly transition metal oxides. For example, oxides such as Cr, Mn, Fe, Co, Ni, Cu, Ti, Zr, and Sn, specifically, Cr ₂ Examples thereof include oxides containing O ₃ , Co ₂ O ₃ , NiO, Fe ₂ O _3, MnO, and the like as components.

In the case of Cr ₂ O ₃ , a green color tone is obtained, in the case of Fe ₂ O ₃ , a red to reddish brown color tone is obtained, in the case of Co ₂ O ₃ , a blue color tone is obtained, and in the case of NiO, from gray A brown color is obtained. Various color tones can be obtained by combining these colored inorganic pigments. Further, as the colored inorganic pigment, in addition to the above, for example, a colloidal metal such as Ag or Au may be used.

In particular, as the black pigment, for example, a metal oxide pigment containing at least one metal selected from the group consisting of Cr, Mn, Fe, Co, Ni, Cu, a composite metal oxide pigment of the metal group, TiO _x or Examples thereof include a titanium black pigment represented by TiO _x N _y . Specific examples of composite metal oxide pigments include, for example, Co—Fe—Cr black pigments, Co—Fe—Al black pigments, Cu—Cr—Mn black pigments, Mn—Bi black pigments, Mn -Y-based black pigment, Fe-Cr-based black pigment, Cr-Cu-based pigment, and Mn-Fe-based pigment can be used, and these can be used alone or in combination of two or more.

In addition, by incorporating a colored inorganic pigment having high infrared concealability, the glass-ceramic composite for chemical strengthening can be provided with an infrared concealment function. Examples of the colored inorganic pigment having a high infrared hiding property include spinel crystals that are complex oxides of Cr, Mn, Fe, Co, Ni, and Cu.

The content of the colored inorganic pigment in the glass ceramic composition varies depending on the type of the colored inorganic pigment, but is preferably 1% by volume or more in the glass ceramic composition. By setting the ratio of the colored inorganic pigment to 1% by volume or more, the glass-ceramic composite for chemical strengthening can be effectively colored. The proportion of the colored inorganic pigment is preferably 2% by volume or more, and more preferably 3% by volume or more. Moreover, since there exists a possibility that intensity | strength may fall when the ratio of a coloring inorganic pigment increases too much, 15 volume% or less is preferable, 13 volume% or less is more preferable, and 10 volume% or less is especially preferable. In addition, when using together a plurality of colored inorganic pigments, it is preferable that the total ratio of the colored inorganic pigments falls within the above range.

D50 of the colored inorganic pigment is preferably 0.2 to 20 μm. When D50 is 0.2 μm or more, the dispersibility is good and uniform coloring is obtained. Moreover, when D50 is 20 micrometers or less, local coloring is suppressed and uniform coloring is obtained. D50 is more preferably 0.5 μm or more, and even more preferably 0.8 μm or more. Further, D50 is more preferably 15 μm or less, and further preferably 13 μm or less.

The content of the glass powder in the glass ceramic composition is a value obtained by subtracting from 100 the total amount of mica powder, other ceramic powder and colored inorganic pigment. The glass powder content is preferably 50 to 85% by volume, more preferably 50 to 75% by volume.

The glass-ceramic composite for chemical strengthening is obtained by molding the above glass-ceramic composition into a green sheet and firing it. Moreover, it can also obtain by the method of baking this, after preparing the paste containing the above-mentioned glass ceramic composition.

(Green sheet manufacturing method)
First, a slurry is prepared by adding a binder and, if necessary, a plasticizer, a solvent, a dispersant and the like to the glass ceramic composition. In the slurry, components other than the glass ceramic composition are all components that disappear during firing.

As the binder, for example, heat-burnable resins such as polyvinyl butyral, acrylic-methacrylic resin, cellulose resin, polyvinyl alcohol, epoxy resin, and cellulose resin can be suitably used. As the plasticizer, for example, dibutyl phthalate, di-2-ethylhexyl phthalate, butyl benzyl phthalate and the like can be used. As the solvent, aromatic solvents such as toluene and xylene, glycol ester solvents such as propylene glycol methyl ether acetate, and alcohol solvents such as 2-propanol and 2-butanol can be used. It is preferable to use a mixture of an aromatic solvent or ester solvent and an alcohol solvent. Further, a dispersant can be used in combination.

The amount of each component in the slurry is 5 to 15 parts by weight of binder, 1 to 5 parts by weight of plasticizer, 2 to 6 parts by weight of dispersant, and 50 to 90 parts by weight of solvent with respect to 100 parts by weight of the glass ceramic composition. Part is preferred.

Next, the obtained slurry is coated on a PET film coated with a release agent using, for example, a doctor blade, formed into a sheet, and dried to produce a green sheet (sheet method). The method for forming the green sheet from the slurry may be a roll forming method.

Further, as the green sheet molding method, besides the above-described sheet method, a cast method such as a slip cast method or a gel cast method, an injection molding method, a powder press firing method, or the like can be applied.

In manufacturing the glass-ceramic composite for chemical strengthening, one green sheet may be used as a single layer or a plurality of sheets may be used. When laminating a plurality of green sheets, these can be integrated by thermocompression bonding.

(Paste manufacturing method)
The glass ceramic composition and the resin component (binder) are blended at a predetermined mass ratio, kneaded in a porcelain mortar or the like, and dispersed in a three-roll or the like to produce a paste.

(Baking method)
Then, after degreasing components for decomposing and removing components other than the glass ceramic composition such as the binder in the green sheet or paste obtained above, the glass ceramic composition is fired to sinter the glass for chemical strengthening. A ceramic composite is obtained.

Degreasing is performed, for example, by holding at a temperature of 400 to 600 ° C. for 1 to 10 hours. When the degreasing temperature is in the above range and the degreasing time is 1 hour or longer, the binder and the like can be sufficiently decomposed and removed. If the degreasing temperature is about 500 ° C. and the degreasing time is about 5 hours, the binder and the like can be sufficiently removed. However, if this time is exceeded, the productivity and the like may be lowered.

The firing temperature is adjusted according to the Ts of the glass powder and the crystallization temperature of the glass constituting the glass matrix. Usually, the calcination temperature is set to a temperature not higher than the crystallization temperature of the glass of the glass matrix and 0 to 200 ° C. higher than Ts of the glass powder, preferably Ts + 50 to Ts + 150 ° C.

For example, when the glass composition of the glass powder is used, a temperature of 700 to 900 ° C. can be used as a firing temperature, and a firing temperature of 750 to 850 ° C. is particularly preferable. The firing time can be adjusted to about 20 to 60 minutes. It is easy to obtain a dense sintered body within the range of the firing temperature and firing time. On the other hand, if the firing temperature is too high or the firing time is too long, the denseness of the chemically strengthened glass-ceramic composite may be lowered or the productivity may be lowered due to crystallization or foaming.

During such a firing operation, only glass powder is melted in the green sheet, the melted glass fills the gaps between the mica powders, and the mica powder is dispersed in the glass matrix. Is obtained.

(Crystallinity)
In the chemically strengthened glass-ceramic composite of the present embodiment, the crystallinity of the glass constituting the glass matrix is preferably 15% or less. The crystallinity X (%) of the glass can be calculated from the X-ray diffraction spectrum of the chemically strengthened glass-ceramic composite powder measured by an X-ray diffractometer according to the following formula (1).

X = I (glass) / {I (Al ₂ O ₃ ) + I (glass)} · 100 (1)
In formula (1), I (glass) indicates the maximum intensity of the X-ray diffraction peak of crystallized glass, and I (Al ₂ O ₃ ) indicates the maximum intensity of the X-ray diffraction peak of alumina. Indicates. In measurement, CuKα rays can be used as characteristic X-rays.

If the glass matrix is partially crystallized, cracks may develop from the boundary between the glass and the crystalline phase, which may reduce the strength. In addition, if glass crystals are precipitated during firing, sintering may not proceed and the denseness of the glass-ceramic composite for chemical strengthening may be lowered, and the softening point of the residual glass may be lowered, resulting in a binder component described later. May not be sufficiently decomposed and blackening may occur. In addition, the dispersibility of the mica powder may be deteriorated and the blending amount may be restricted. Furthermore, it is difficult to control the precipitation of crystals, and the strength of the glass-ceramic composite for chemical strengthening may vary due to variations in the precipitation of crystals.

From the viewpoint of preventing such inconveniences, it is preferable that no crystals are generated in the glass matrix formed in the firing process. That is, it is preferable that the crystallized glass peak is not detected in X-ray diffraction and the crystallinity is 0%.

However, when the glass-ceramic composite for chemical strengthening is produced in an environment where the production conditions are sufficiently controlled, the glass matrix may contain a crystal phase up to a certain level. Specifically, as long as the crystallinity of the glass matrix is up to 15%, a crystal phase may be included, and the crystallinity is preferably 10% or less, more preferably 5% or less. As an example of the above production conditions, a glass-ceramic composite for chemical strengthening is produced in a stage where the binder component is sufficiently decomposed in the production process and controlled so that crystal precipitation occurs uniformly. It is.

(3-point bending strength)
The three-point bending strength of the glass-ceramic composite for chemical strengthening is preferably more than 100 MPa. By making the three-point bending strength of the glass-ceramic composite for chemical strengthening greater than 100 MPa, it is possible to improve machinability while imparting sufficient strength to the glass-ceramic composite for chemical strengthen. The strength of the glass-ceramic composite for chemical strengthening is more preferably 120 MPa or more, and particularly preferably 150 MPa or more. The three-point bending strength is more preferably 170 MPa or more, and most preferably 200 MPa or more. In addition, the 3 point | piece bending strength in this specification means the 3 point | piece bending strength obtained by the method based on JISC2141.

The content of each component in the glass-ceramic composite for chemical strengthening of the present embodiment hardly changes from the mixing ratio of each material when the glass-ceramic composite for chemical strengthening is produced by the above-described manufacturing method. Therefore, the mixing ratio of each material can be regarded as the content of each component in the chemically strengthened glass-ceramic composite. For example, the amount of mica powder relative to the glass matrix component in the chemically strengthened glass ceramic composite can be regarded as the content of mica powder in the glass ceramic composition. Further, the content of each component in the glass matrix can be regarded as the content of each component in the glass powder.

(Composition analysis method)
When directly analyzing the composition of the glass-ceramic composite for chemical strengthening, a method of calculating from the exclusive area of each component in an arbitrary cross section of the glass-ceramic composite for chemical strengthening can be used. In the glass-ceramic composite for chemical strengthening of the present embodiment, each raw material component is dispersed almost uniformly in the glass-ceramic composite for chemical strengthening when manufactured by the above-described manufacturing method. Therefore, the composition calculated from the exclusive area of each component in an arbitrary cross section can be regarded as the composition of the glass-ceramic composite for chemical strengthening to be analyzed. In addition, the glass-ceramic composite for chemical strengthening is dissolved using an agent that dissolves only the glass matrix (for example, dilute hydrofluoric acid), the mass of the glass matrix and the mass of mica are measured, and the specific gravity is calculated from the obtained mass. The composition can also be analyzed by a method of calculating the volume ratio using.

(Infrared transmittance)
When the glass-reinforced ceramic composite for chemical strengthening according to the present embodiment includes the above-described infrared shielding colored inorganic pigment as the colored inorganic pigment, the infrared transmittance can be extremely reduced. Such an infrared shielding chemical-strengthening glass-ceramic composite has an infrared transmittance of 0.001% or less at a wavelength of 600 to 1000 nm when the thickness of the chemical-strengthening glass-ceramic composite is 1 mm. preferable. The infrared-shielding glass-ceramic composite for chemical strengthening is suitable for applications such as packages and casings of vital sensing devices that use near-infrared sensors for measuring pulse, hemoglobin concentration in blood, blood oxygen concentration, and the like. The infrared transmittance can be measured using a spectrophotometer. As the spectrophotometer, for example, SolidSpec-3700 manufactured by Shimadzu Corporation or LAMBDA950 or 1050 manufactured by PerkinElmer may be used.

<Chemically tempered glass ceramic composite and its manufacturing method>
The chemically strengthened glass-ceramic composite of the present embodiment is usually formed into the desired shape, for example, a plate shape, and further subjected to desired machining as required, as obtained above. Then, it can obtain by performing a chemical strengthening process.

The plate-shaped glass-ceramic composite for chemical strengthening can be obtained, for example, by the method for producing the green sheet. Examples of the machining include drilling and the like such as making a hole in the chemically strengthened glass ceramic composite.

As a method of chemical strengthening treatment, Na ⁺ of the surface layer of the glass-ceramic composite for chemical strengthening and K ⁺ in the molten salt, or Li ⁺ of the surface layer of the glass-ceramic composite for chemical strengthening, Na ⁺ and K ⁺ in the molten salt are used. There is no particular limitation as long as ion exchange is possible. For example, in the case where ion exchange is performed between Na ^{+ on the} surface layer of the chemically strengthened glass ceramic composite and K ⁺ in the molten salt, a method of immersing the chemically strengthened glass ceramic composite in a heated potassium nitrate (KNO ₃ ) molten salt is given. It is done. When ion exchange is performed on Li ⁺ and Na ^{+ on} the surface layer of the glass-ceramic composite for chemical strengthening and Na ⁺ and K ⁺ in the molten salt, a Na ₂ O molten salt should be used instead of the KNO ₃ molten salt. Can do. It is also possible to use a mixture of NaNO ₃ molten salt KNO ₃ molten salt.

The conditions of the chemical strengthening treatment vary depending on the thickness and size of the glass-ceramic composite for chemical strengthening, but the glass-ceramic composite for chemical strengthening may be immersed in a molten salt at 350 to 550 ° C. for 0.5 to 20 hours. Typical. Further, in order to further improve the strength of the chemically strengthened glass ceramic composite, the chemical strengthening glass ceramic composite is immersed in a molten salt, washed with water, and further immersed in the molten salt to perform a two-step chemical strengthening treatment. Good.

In the thus obtained chemically strengthened glass-ceramic composite, a surface compressive stress layer in which Na ⁺ or K ^+, which is a cation component of the strengthening salt, is concentrated on the surface is obtained by performing the above chemical strengthening treatment. It is formed. The composition of the glass constituting the glass matrix after the chemical strengthening treatment is 40% to 65% of SiO ₂ and 8% of Al ₂ O ₃ as the average composition of the glass matrix in terms of oxides. More than 0% to 21.0% or less, B ₂ O ₃ to more than 5% to 40%, one or more selected from Li ₂ O, Na ₂ O and K ₂ O in total 5 to 23%, alkaline earth It is preferable that the metal oxide contains 0 to less than 2%.

Moreover, the depth of the surface compressive stress layer in which Na ⁺ or K ⁺ is concentrated as described above is, for example, 30 μm or more. In the chemically strengthened glass ceramic composite, the average composition in the surface compressive stress layer, that is, the average composition from the surface to 30 μm is mol% in terms of oxide, 0 to 6% of Li ₂ O, K ₂ O and A composition containing 8 to 23% in total of at least one selected from Na ₂ O is preferable.

The average composition of the glass matrix in the chemically strengthened glass-ceramic composite and the average composition from the surface to 30 μm are mirror-polished on the sample cross section of the chemically strengthened glass-ceramic composite after chemical strengthening, and energy dispersive X-ray spectroscopy (SEM- Quantitative analysis is performed by dividing the area with EDX), and the average composition over the entire surface of the glass matrix and 30 μm from the surface can be calculated using the analysis result.

(3-point bending strength)
The three-point bending strength of the chemically tempered glass ceramic composite of this embodiment can be over 250 MPa. By setting the three-point bending strength of the chemically strengthened glass ceramic composite to more than 250 MPa, the high strength of the chemically strengthened glass ceramic composite can be realized. The three-point bending strength of the chemically strengthened glass ceramic composite is more preferably more than 300 MPa, and more preferably more than 350 MPa.

(Strength ratio)
The glass-ceramic composite for chemical strengthening according to the present embodiment has a three-point bending strength improved by the chemical strengthening treatment because the glass matrix is made of glass having the above-described composition. The ratio of the three-point bending strength before and after chemical strengthening is “three-point bending strength of chemically strengthened glass-ceramic composite (after chemical strengthening) / three-point bending strength of glass-ceramic composite for chemical strengthening (before chemical strengthening)” (below) The ratio represented simply by “after chemical strengthening / before chemical strengthening”) is preferably 1.2 or more, and more preferably 1.5 or more. In this case, it is possible to obtain a chemically strengthened glass-ceramic composite having excellent strength while further improving the machinability before chemical strengthening.

(Composition analysis method, infrared transmittance)
The composition of the chemically strengthened glass-ceramic composite can also be regarded as the blending ratio of each raw material component, like the above-described chemically strengthened glass-ceramic composite. Moreover, you may analyze by the method similar to the said glass ceramic composite for chemical strengthening. Further, since the infrared transmittance hardly changes due to chemical strengthening, the infrared transmittance of the chemically strengthened glass-ceramic composite can be equated with that of the chemically strengthened glass-ceramic composite.

According to the glass-ceramic composite for chemical strengthening of the present embodiment described above, it has excellent machinability and can impart high strength to the chemically strengthened glass-ceramic composite obtained by chemical strengthening. Moreover, according to the manufacturing method of the chemically strengthened glass ceramic composite of this invention, it is excellent in machinability and can give high intensity | strength to a chemically strengthened glass ceramic composite.

Hereinafter, specific description will be given with reference to examples. The present invention is not limited to the following examples.
[Examples: Examples 1 to 12 and Examples 20 to 27, Comparative Examples; Examples 13 to 19]
<Manufacture of glass powder>
Each glass raw material was blended and mixed to obtain a glass having a ratio (mole percentage in terms of oxide) shown in Table 1, and the raw material mixture was put into a platinum crucible and melted at 1500 to 1700 ° C. for 90 minutes. . The melt is passed through a stainless steel water-cooled roll to obtain a flaky glass having a thickness of 0.3 to 1.0 mm. Thereafter, the average particle size (D50) is pulverized to 2 μm by a ball mill to obtain glass powders G1 to G1 of each composition. G12 was obtained.

For the obtained glass powders G1 to G12, Ts and Tg were measured by the following methods. The results are shown in the lower column of Table 1. In addition, the glass powder G12 was a non-melting defect which produced a cloudiness part in a part of obtained glass, and a homogeneous glass was not obtained.

(Tg, Ts)
The first inflection point was measured as Tg [° C.] and the fourth inflection point was Ts [° C.] by DTA (Differential Thermal Analysis, differential thermal analysis).

The following were used as fillers to be mixed with the glass powder.
Mica powder: Fluorophlogopite powder (average particle size (D50): 5 μm)
Alumina powder (A): Aluminum oxide powder (average particle size (D50): 0.5 μm)
Alumina powder (B): Aluminum oxide powder (D50: 1.5 μm)
Alumina powder (C): Aluminum oxide powder (D50: 0.2 μm)
Alumina powder (D): Aluminum oxide powder (D50: 0.1 μm)
Black pigment: complex oxide powder such as Cr, Mn, Fe, Co, Ni, Cu (average particle diameter (D50): 1 μm)

<Manufacture of glass-ceramic substrates for chemical strengthening>
Next, as shown in Tables 2 to 4, glass powder and mica powder, alumina powder, and black pigment as fillers are blended in a predetermined ratio (volume%) and mixed to obtain a glass ceramic composition. Got.

Using the glass ceramic composition obtained above, green sheets were produced as shown below. 50 g of glass ceramic composition, 15 g of organic solvent (mixed with toluene, xylene, 2-propanol, 2-butanol at a mass ratio of 4: 2: 2: 1), plasticizer (di-2-ethylhexyl phthalate) 2 0.5 g, 5 g of an acrylic-methacrylic copolymer resin as a binder, and 0.5 g of a dispersant were mixed and mixed to form a slurry. This slurry was applied onto a PET film by a doctor blade method and dried. The gap of the doctor blade was adjusted so that the sheet had a thickness of 200 μm after firing to produce a green sheet. The obtained green sheet was cut and cut into 50 mm squares (50 mm long and 50 mm wide) to obtain green sheets for evaluation.

Four green sheets thus obtained were superposed and held at 450 ° C. for 2 hours in a continuous firing furnace to decompose and remove components other than the glass ceramic composition such as a binder, and then Tables 2 to 4 were used. The firing temperature was maintained at 45 minutes (0.75 hour) for firing. In this way, a glass ceramic substrate for chemical strengthening (thickness: about 800 μm) of each example was obtained.

<Evaluation>
The following evaluations were performed on each chemically strengthened glass ceramic substrate obtained in each of the above examples.

(3-point bending strength)
The glass ceramic substrate for chemical strengthening obtained in each example was subjected to a three-point bending strength test in accordance with JIS C2141. That is, a load when one side of a glass-ceramic substrate for chemical strengthening is supported at two points and a load is gradually applied to an intermediate position between the two points on the side facing the substrate, and the glass-ceramic substrate for chemical strengthening is destroyed. The three-point bending strength (MPa) was calculated based on this. The bending strength was measured at 30 points to determine an average value (average bending strength). The results are shown in the lower column of Tables 2-4.

(Machinability)
A glass ceramic substrate for chemical strengthening was drilled with a drill, and the degree of chipping was evaluated. The results are shown in the lower columns of Tables 2 to 4. When the chipping was observed with an optical microscope and the maximum chipping length was 0.1 mm or less, it was judged that the machinability was good. In the case of exceeding 1 mm, the machinability was judged to be poor and indicated as x.

(density)
The density of the glass-ceramic substrate for chemical strengthening was measured by the Archimedes method.

(Young's modulus)
The Young's modulus of the glass-ceramic substrate for chemical strengthening was measured by an ultrasonic method (pulse echo overlap method).
(Fracture toughness)
The fracture toughness of the glass-ceramic substrate for chemical strengthening was measured in accordance with IF method (Indentation Fracture Method) of JIS R1607.

<Manufacture of chemically strengthened glass ceramic substrate>
The glass-ceramic substrates for chemical strengthening of the respective examples obtained above were melted in the strengthening salts (KNO ₃ molten salt or NaNO ₃ molten salt) held at the strengthening temperatures shown in Tables 2 to 4, respectively. Chemical strengthening treatment was performed by immersing in the time shown in (1 to 8 hours) to obtain a chemically strengthened glass ceramic substrate. Further, for examples 25 and 27, using a KNO ₃ molten salt and NaNO ₃ molten salt as shown in Table 4 were sequentially subjected to chemical strengthening treatment of two stages.

<Evaluation>
The chemically tempered glass ceramic substrate obtained in each of the above examples was washed with water and then evaluated as follows.

(3-point bending strength)
In the same manner as described above, the three-point bending strength (average bending strength) of the chemically strengthened glass ceramic substrate was measured. The results are shown in the lower column of Tables 2-4.
(Fracture toughness)
In the same manner as described above, the fracture toughness of the chemically strengthened glass ceramic substrate was measured.

As shown in Tables 2 to 4, the glass ceramics for chemical strengthening of Examples 1 to 12 and Examples 20 to 27 (Examples) obtained by sintering a glass ceramic composition containing glass powder having a predetermined composition and mica powder It can be seen that the composite has good machinability, and the chemical strengthening sufficiently improves the strength, and a chemically strengthened glass-ceramic composite with high strength is obtained.

On the other hand, it can be seen that the glass-ceramic composites for chemical strengthening of Examples 13 to 19 (comparative examples) have poor machinability or insufficient strength after chemical strengthening.

Claims (13)

1. A glass-ceramic composite for chemical strengthening in which mica powder is dispersed in a glass matrix,
   The glass constituting the glass matrix is
   In mol% in terms of oxide, SiO ₂ is 40 to 65%, Al ₂ O ₃ is more than 8.0 and 21.0% or less, B ₂ O ₃ is more than 5% and 40% or less, Li ₂ O and Na _A glass-ceramic composite for chemical strengthening comprising 5 to 23% in total of at least one selected from ₂ O and 0 to less than 2% of an alkaline earth metal oxide.
2. The glass-ceramic composite for chemical strengthening according to claim 1, wherein Li ₂ O and Na ₂ O in the glass have a Li ₂ O / Na ₂ O ratio of 0.35 to 4.
3. The glass-ceramic composite for chemical strengthening according to claim 1 or 2, wherein B ₂ O ₃ and SiO ₂ in the glass have a SiO ₂ / B ₂ O ₃ ratio of 1 to 13.
4. The glass ceramic composite for chemical strengthening according to any one of claims 1 to 3, comprising 15 to 50% by volume of mica powder with respect to the total volume of the glass ceramic composite for chemical strengthening.
5. The glass-ceramic composite for chemical strengthening according to any one of claims 1 to 4, wherein the glass matrix has a crystallinity of 15% or less.
6. The glass-ceramic composite for chemical strengthening according to any one of claims 1 to 5, further comprising a colored inorganic pigment.
7. The glass ceramic composite for chemical strengthening according to any one of claims 1 to 6, wherein an infrared transmittance at a wavelength of 600 to 1000 nm is 0.001% or less when the thickness of the glass ceramic composite for chemical strengthening is 1 mm. body.
8. The glass-ceramic composite for chemical strengthening according to any one of claims 1 to 7, wherein the glass-ceramic composite for chemical strengthening has a plate shape and is machined.
9. A chemically strengthened glass ceramic composite that has been subjected to a chemical strengthening treatment,
   Mica powder is dispersed in a glass matrix,
   The glass constituting the glass matrix is, as an average composition of the glass matrix,
   In mol% in terms of oxide, SiO ₂ is 40 to 65%, Al ₂ O ₃ is more than 8.0 and 21.0% or less, B ₂ O ₃ is more than 5% and 40% or less, Li ₂ O, Na _A chemically strengthened glass-ceramic composite containing a total of 5 to 23% of one or more selected from ₂ O and K ₂ O and 0 to less than 2% of an alkaline earth metal oxide.
10. As an average composition from the surface of the chemically strengthened glass ceramic composite to 30 μm,
    The chemically strengthened glass-ceramic composite according to claim 9, comprising 0 to 6% of Li ₂ O and 8 to 23% in total of at least one selected from K ₂ O and Na ₂ O in terms of mol% in terms of oxide. body.
11. The chemically strengthened glass ceramics according to claim 9 or 10, wherein a three-point bending strength of the chemically strengthened glass ceramic composite measured by a method in accordance with JIS C2141 is 1.2 or more, with 1 before chemical strengthening. Complex.
12. Glass particles and mica powder, the content of the mica powder with respect to the total of the glass particles and mica powder is 15 to 50% by volume, the glass particles are mol% in terms of oxide, and SiO ₂ is 40%. ~ 65%, Al ₂ O ₃ more than 8.0 and 21.0% or less, B ₂ O ₃ more than 5% and 40% or less, and one or more of Li ₂ O and Na ₂ O in total 5 ~ Sintering a glass ceramic composition containing 23% alkaline earth metal oxide and less than 0-2% to obtain a glass-ceramic composite for chemical strengthening;
    And a step of obtaining a chemically strengthened glass ceramic composite that has been chemically strengthened by subjecting the glass ceramic composite for chemical strengthening to chemical strengthening.
13. The chemical strengthening glass-ceramic composite is plate-shaped,
    The method for producing a chemically strengthened glass ceramic composite according to claim 12, further comprising a step of machining the chemically strengthened glass ceramic composite.