WO2023127562A1 - 高透光性アルミナ焼結体となる歯科用アルミナ仮焼体 - Google Patents

高透光性アルミナ焼結体となる歯科用アルミナ仮焼体 Download PDF

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Publication number
WO2023127562A1
WO2023127562A1 PCT/JP2022/046491 JP2022046491W WO2023127562A1 WO 2023127562 A1 WO2023127562 A1 WO 2023127562A1 JP 2022046491 W JP2022046491 W JP 2022046491W WO 2023127562 A1 WO2023127562 A1 WO 2023127562A1
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Prior art keywords
alumina
dental
sintered body
calcined body
sintering aid
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PCT/JP2022/046491
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English (en)
French (fr)
Japanese (ja)
Inventor
貴理博 中野
紘之 坂本
信介 樫木
新一郎 加藤
博重 石野
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Kuraray Noritake Dental Inc
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Kuraray Noritake Dental Inc
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Priority to US18/724,606 priority Critical patent/US20250064565A1/en
Priority to KR1020247020759A priority patent/KR20240113801A/ko
Priority to JP2023570867A priority patent/JPWO2023127562A1/ja
Publication of WO2023127562A1 publication Critical patent/WO2023127562A1/ja
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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K6/00—Preparations for dentistry
    • A61K6/15—Compositions characterised by their physical properties
    • A61K6/17—Particle size
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K6/00—Preparations for dentistry
    • A61K6/80—Preparations for artificial teeth, for filling teeth or for capping teeth
    • A61K6/802—Preparations for artificial teeth, for filling teeth or for capping teeth comprising ceramics
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
    • A61C13/00—Dental prostheses; Making same
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
    • A61C13/00—Dental prostheses; Making same
    • A61C13/0003—Making bridge-work, inlays, implants or the like
    • A61C13/0022—Blanks or green, unfinished dental restoration parts
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
    • A61C13/00—Dental prostheses; Making same
    • A61C13/08—Artificial teeth; Making same
    • A61C13/083—Porcelain or ceramic teeth
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
    • A61C5/00—Filling or capping teeth
    • A61C5/70—Tooth crowns; Making thereof
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K6/00—Preparations for dentistry
    • A61K6/60—Preparations for dentistry comprising organic or organo-metallic additives
    • A61K6/65—Dyes
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K6/00—Preparations for dentistry
    • A61K6/70—Preparations for dentistry comprising inorganic additives
    • A61K6/78—Pigments
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K6/00—Preparations for dentistry
    • A61K6/80—Preparations for artificial teeth, for filling teeth or for capping teeth
    • A61K6/802—Preparations for artificial teeth, for filling teeth or for capping teeth comprising ceramics
    • A61K6/804—Preparations for artificial teeth, for filling teeth or for capping teeth comprising ceramics comprising manganese oxide
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K6/00—Preparations for dentistry
    • A61K6/80—Preparations for artificial teeth, for filling teeth or for capping teeth
    • A61K6/802—Preparations for artificial teeth, for filling teeth or for capping teeth comprising ceramics
    • A61K6/818—Preparations for artificial teeth, for filling teeth or for capping teeth comprising ceramics comprising zirconium oxide
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K6/00—Preparations for dentistry
    • A61K6/80—Preparations for artificial teeth, for filling teeth or for capping teeth
    • A61K6/84—Preparations for artificial teeth, for filling teeth or for capping teeth comprising metals or alloys
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
    • C04B35/10—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on aluminium oxide
    • C04B35/111—Fine ceramics
    • C04B35/117—Composites
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61C—DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE
    • A61C2201/00—Material properties
    • A61C2201/002—Material properties using colour effect, e.g. for identification purposes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B11/00—Apparatus or processes for treating or working the shaped or preshaped articles
    • B28B11/24—Apparatus or processes for treating or working the shaped or preshaped articles for curing, setting or hardening
    • B28B11/243—Setting, e.g. drying, dehydrating or firing ceramic articles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B3/00—Producing shaped articles from the material by using presses; Presses specially adapted therefor
    • B28B3/02—Producing shaped articles from the material by using presses; Presses specially adapted therefor wherein a ram exerts pressure on the material in a moulding space; Ram heads of special form
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
    • C04B2235/96—Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance

Definitions

  • the present invention relates to a calcined body that has aluminum oxide (alumina) as a main component and becomes a highly transparent sintered body after firing, a highly aesthetic sintered body, and a method for producing the same.
  • aluminum oxide alumina
  • sintered bodies of metal oxides have become popular as dental materials.
  • a sintered body whose color tone and translucency are adjusted is used according to the appearance of healthy teeth remaining around the treatment site of the patient.
  • the incisal edge is more transparent, and the cervical area is adjusted to have a darker color.
  • Metal oxides used in dental materials include glass, zirconia, aluminum oxide and the like (for example, Patent Documents 1 and 2). Glass has high transparency but low tensile strength, and zirconia has high strength but lacks transparency. Aluminum oxide can be made into a high-strength and highly transparent material by using special firing equipment such as HIP (Hot Isostatic Pressing) or hydrogen firing. was disadvantageous.
  • HIP Hot Isostatic Pressing
  • Patent Literature 1 discloses a zirconia sintered body with different shades of color, and describes a zirconia sintered body in which the tendency of increase and decrease of L*a*b* values does not change in the direction of shade.
  • the zirconia sintered body in Patent Document 1 is excellent in terms of color tone, the zirconia material has a low linear light transmittance, so there is room for improvement in the transparency of the incision. It is difficult to say that the use of zirconia alone does not completely have the aesthetic properties suitable for dental use, because the appearance is more similar to that of natural teeth.
  • Patent Document 2 describes an alumina sintered body that is said to have aesthetic properties suitable for dental applications. *Values not disclosed.
  • the median diameter D50 of the alumina powder used is as large as 0.45 ⁇ m at minimum, a high linear light transmittance has not been obtained.
  • a sintering aid is added to the alumina powder and fired under atmospheric pressure, there is a problem that the translucency decreases due to yellowing. It cannot be said that it has the aesthetics suitable for the application.
  • the calcined body that becomes an alumina sintered body with high linear light transmittance and suppressed yellowness. Therefore, the calcined body that can be a high-aesthetic sintered body suitable for dental applications, particularly the tip portion (incisal edge) of a tooth, has not been sufficiently studied.
  • An object of the present invention is to provide an alumina calcined body that becomes an alumina sintered body that is suitable for uses and has high aesthetics.
  • the present inventors have made intensive studies to solve the above problems, and found that an alumina calcined body containing an average primary particle size of 30 to 300 nm, a sintering aid of 10 to 5000 ppm, and a blue colorant found that after sintering under atmospheric pressure, it has excellent translucency and linear light transmittance, so it has high aesthetics. reached.
  • the present invention includes the following inventions.
  • [1] Contains alumina particles with an average primary particle size of 30 to 300 nm, a sintering aid, and a blue colorant, A dental alumina calcined body, wherein the content of the sintering aid is 10 to 5000 ppm.
  • [2] The dental alumina calcined body according to [1], wherein the blue colorant contains a cobalt component.
  • the dental alumina calcined body according to [2], wherein the cobalt component content is 60 ppm or less.
  • [4] The dental alumina calcined body according to [2] or [3], wherein the cobalt component is derived from a salt and/or a complex.
  • Alumina calcined body for [8] The dental alumina calcined body according to any one of [1] to [7], wherein the alumina particles contain ⁇ -alumina with a purity of 99.5% or more.
  • a method for producing a dental alumina calcined body comprising: including a step of uniformly fixing the blue colorant to the alumina particles;
  • the dental alumina calcined body contains alumina particles having an average primary particle size of 30 to 300 nm, a sintering aid, and a blue colorant,
  • the dental alumina according to [11], wherein the step of uniformly fixing the blue colorant to alumina particles includes a step of dispersing ⁇ -alumina particles in a dispersion medium in which the blue colorant is dissolved.
  • a method for producing a calcined body [13] The method for producing a dental alumina calcined body according to [11] or [12], which includes the step of firing at 600° C. or higher and 1200° C. or lower under atmospheric pressure. [14] has an average crystal grain size of 0.3 to 8.0 ⁇ m and contains a sintering aid and a blue colorant; A dental alumina sintered body, wherein the content of the sintering aid is 10 to 5000 ppm. [15] The dental alumina sintered body according to [14], wherein the blue colorant contains a cobalt component. [16] The dental alumina sintered body according to [15], wherein the cobalt component content is 60 ppm or less.
  • the sintered body has high translucency and high linear light transmittance even when sintered under atmospheric pressure. It is possible to provide a dental alumina calcined body that becomes an alumina sintered body that is suitable for use and has high aesthetics. Moreover, according to the present invention, it is possible to provide a dental alumina calcined body that becomes an alumina sintered body having high esthetics particularly suitable for the appearance of the incisal edges of incisors or canines.
  • FIG. 1 is an electron micrograph of a calcined body according to Example 1.
  • the alumina calcined body of the present invention contains alumina particles having an average primary particle diameter of 30 to 300 nm, a sintering aid, and a blue colorant, and the content of the sintering aid is 10 to 5000 ppm.
  • a calcined body of the present invention will be described.
  • a calcined body can be a precursor (intermediate product) of a sintered body.
  • a calcined body is a product in which alumina particles are necked together and solidified in a state in which the alumina particles are not completely sintered.
  • the calcined body may have a predetermined shape (for example, disk shape, rectangular parallelepiped shape, etc.).
  • the calcined body may be, for example, a crown-shaped processed body, and when processed, it is referred to as a "processed body” or a "cut or ground body".
  • the processed body is obtained, for example, by processing an alumina disk, which is a calcined body, into a dental product (for example, a crown-shaped prosthesis) using a CAD/CAM (Computer-Aided Design/Computer-Aided Manufacturing) system.
  • a CAD/CAM Computer-Aided Design/Computer-Aided Manufacturing
  • the calcined body of the present invention includes adherents of particles made of alumina (hereinafter sometimes simply referred to as "alumina particles"). Hardness changes. The smaller the average primary particle size of the alumina particles, the more likely it is to cause sticking (necking) during calcination.
  • the alumina calcined body of the present invention contains a sintering aid (an aid that accelerates and stabilizes sintering of alumina) from the viewpoint of increasing the strength after sintering and particularly from the viewpoint of achieving high aesthetics. .
  • the sintering aid contained in the alumina calcined body of the present invention is at least one selected from the group consisting of Group 2 elements (Be, Mg, Ca, Sr, Ba, Ra), Ce, Zr, and Y. element, more preferably at least one element selected from the group consisting of Mg, Ca, Sr, Ba, Ce, Zr, and Y, consisting of Mg, Ce, Zr, and Y More preferably, it contains at least one element selected from the group.
  • magnesium compounds are most preferable. Magnesium compounds include oxides, nitrates, acetates, hydroxides, chlorides and the like.
  • sintering aids examples include MgCl 2 , Mg(OH) 2 , CeO 2 , ZrO 2 , Y 2 O 3 and the like.
  • the magnesium compound of the sintering aid is not limited to any magnesium compound that becomes an oxide at 1200° C. or less during sintering in the air. Magnesium and magnesium acetate can be mentioned.
  • a sintering aid may be used individually by 1 type, and may use 2 or more types together.
  • the content of the sintering aid in the raw material alumina powder of the present invention is preferably 10 ppm or more and 5000 ppm or less, more preferably 20 ppm or more and 3000 ppm or less, and still more preferably It is 30 ppm or more and 1500 ppm or less.
  • ppm means mass ppm.
  • the content of the sintering aid preferably magnesium compound
  • the color tone of the sintered body tends to be whiter than that of natural teeth, and if it is too high, the yellowish or reddish color may increase.
  • the mechanism by which the sintering aid (e.g., magnesium oxide) increases the sintering density is that it exists as a heterogeneous phase at the grain boundary and suppresses the growth and development of the grain boundary, so pores are incorporated into the grain.
  • the content of the sintering aid in the alumina powder is calculated in terms of the elements constituting the sintering aid (for example, Mg 10 to 100 ppm, or even 20 to 50 ppm in terms of elements).
  • the content of the sintering aid in the alumina calcined body of the present invention and the later-described alumina composition is the same as the content of the sintering aid in the alumina powder.
  • the alumina particles contained in the alumina calcined body of the present invention have an average primary particle size of 30 to 300 nm from the viewpoint of high linear light transmittance and translucency.
  • the average primary particle size is less than 30 nm, the sintered body becomes yellowish, which is not preferable.
  • it exceeds 300 nm the grain size in the sintered body after sintering increases, the average crystal grain size becomes too large, and the esthetics and strength as a dental material are lowered, which is not preferable.
  • the average primary particle size of the alumina particles is preferably 40 to 250 nm, more preferably 60 to 200 nm, even more preferably 80 to 150 nm.
  • the method for measuring the average primary particle size in the calcined body is as described in Examples below.
  • the calcined body of the present invention contains a blue colorant (pigment, composite pigment) (hereinafter referred to as "blue colorant”) that exhibits a blue color after sintering.
  • a blue colorant pigment, composite pigment
  • the pigment for example, at least selected from the group of Ti, V, Cr, Mn, Fe, Co, Ni, Zn, Y, Zr, Sn, Sb, Bi, Ce, Sm, Eu, Gd, and Er One element is mentioned.
  • the b* value increases.
  • a blue colorant having a negative b* value is preferred. It is particularly preferable that the blue colorant contains a cobalt component (hereinafter also referred to as "Co component").
  • Co component a cobalt component
  • the components of the pigment may be used singly or in combination of two or more.
  • a combination of pigments that decrease the b* value without affecting the a* value is preferable for the color development of the pigments.
  • the combination of the pigments for example, since addition of the Co component causes a decrease in the b* value and a decrease in the a* value at the same time, a combination with a pigment that causes an increase in the a* value is more preferable.
  • Cr element in combination as an element capable of suppressing the decrease of the a* value due to Co when the same amount of element as Co is added in terms of mass.
  • the ratio of Co and Cr is preferably 0.8 to 1.25, more preferably 0.9 to 1.1.
  • the method for measuring the a* value is as described in Examples below.
  • the Co component content in the alumina calcined body of the present invention is preferably 60 ppm or less, more preferably 50 ppm or less, and even more preferably 25 ppm or less in terms of cobalt element.
  • it is 60 ppm or less, the bluish color development does not become too strong, the yellowing of the sintered body after sintering can be suppressed, the aesthetic appearance as a cut edge is excellent, and it is integrated with the sintering aid. Since it is superior in translucency and linear light transmittance, it is possible to reproduce a color tone close to that of natural teeth for dental applications.
  • the ratio (mass ratio ), when the sintering aid contains the Mg element, the sintered body can maintain high translucency and linear light transmittance even when sintered under atmospheric pressure together with other components, From the viewpoint of maintaining high strength, Mg:Co 1000:0.05 to 1000:60 is preferable, 1000:0.1 to 1000:55 is more preferable, and 1000:0.5 to 1000 :50 is more preferred, and 1000:1 to 1000:25 is particularly preferred.
  • the chemical existence state of the pigment is not particularly limited as long as it develops color after baking the alumina. It may be a metal salt, an organometallic complex, a metal hydroxide, a metal oxide, or an oligomer or polymer in which these states are combined.
  • the cobalt component is preferably a component derived from a salt and/or a complex from the viewpoint of excellent dispersibility and excellent uniform color development.
  • Specific compounds of the blue colorant include bis(acetylacetonato)diaquacobalt(II), tris(acetylacetonato)cobalt(III), cobalt amide sulfate(II) hydrate, cobalt benzoate ( II), cis-tetraamminedichlorocobalt (III) chloride, pentaamminechlorocobalt (III) chloride, hexaamminecobalt (III) chloride, hexaamminecobalt (III) nitrate, diamminetetranitrocobalt (III) ammonium.
  • (Ni, Co, Fe) (Fe, Cr) 2 O 4 ⁇ ZrSiO 4 , (Co, Zn) Al 2 O 4 and the like can be used as composite pigments of blue colorants.
  • cobalt (II) chloride hydrate, cobalt (II) perchlorate hydrate, cobalt (II) fluoride hydrate, cobalt (II) nitrate hydrate, oxalic acid Cobalt (II) hydrate and cobalt (II) acetate hydrate are preferred, and cobalt (II) chloride hydrate is more preferred.
  • These Co components can be used singly or in combination of two or more.
  • the pigment is uniformly dispersed in the calcined body. If the pigment is non-uniformly present in the calcined body, it is not preferable because the portions that develop color after sintering will be localized, and color unevenness will be visually recognized.
  • the dispersed state of the pigment can be confirmed by composition analysis of the calcined body.
  • a known method can be used as a composition analysis method. For example, scanning or transmission electron microscope (SEM or TEM) and energy dispersive X-ray analysis or wavelength dispersive X-ray analysis (EDX or WDX), or field emission electron beam microanalysis (FE-EPMA), etc. can do.
  • a field emission scanning electron microscope (FE-SEM Reglus 8220, manufactured by Hitachi High-Tech Co., Ltd.) and an energy dispersive X-ray analyzer ( Aztec Energy X-Max50 (manufactured by Oxford Instruments) can be used for measurement under the following conditions.
  • Measurement magnification 20,000 times
  • Analysis mode Line analysis Acceleration voltage: 5 kV
  • Working distance 15mm ⁇ 1mm
  • X-ray extraction angle 30 degrees
  • Dead time 7% Measurement time: 100 seconds
  • the physical distance between one maximum value and the minimum value around that maximum value in the waveform of the detected amount of the elements constituting the pigment obtained by line analysis is By calculating the average value between the maximal value and the minimal value that match, it is possible to obtain the physical distance of the density difference of the elements constituting the pigment.
  • the number of fields of view is changed so that 20 or more fields of view are connected, and the distance of line analysis is preferably 50 ⁇ m or more within the connected fields of view. It is preferable to measure 20 or more points for analysis. It is preferable to use the average value of the waveform obtained by line analysis as the physical distance.
  • the physical distance of the concentration difference of the elements that constitute the pigment is preferably within 50 ⁇ m because the difference in concentration of the pigment that develops color after firing can be made invisible to the naked eye.
  • the concentration difference of the elements constituting the pigment is more preferably within 30 ⁇ m, more preferably within 10 ⁇ m.
  • the frequency of the waveform of the detected amount of the elements that make up the pigment obtained by the line analysis in the region where alumina was detected by the line analysis is Fourier. It may be converted and parsed. It is preferable that the period determined from the peak top frequency in the Fourier spectrum is within 50 ⁇ m. If it exceeds 50 ⁇ m, it is not preferable because the possibility of visually confirming the difference in concentration of the pigment that develops color after baking increases.
  • the concentration difference of the elements constituting the pigment is more preferably within 30 ⁇ m, more preferably within 10 ⁇ m.
  • the index can be the physical distance obtained from the line analysis waveform or the period of Fourier analysis.
  • the main component contained in the calcined body of the present invention is alumina, it is preferable because it enhances the aesthetics of the sintered body as a dental material and has excellent chemical stability.
  • the main component is the component with the highest content.
  • the content of the main component may be, for example, 50% by mass or more, 70% by mass or more, 80% by mass or more, or 90% by mass or more.
  • ⁇ -alumina with a purity of 99.5% or more has few impurities, suppresses the formation of a glass phase at the grain boundaries due to impurities, and crystal grains (grains ) can be prevented from becoming coarse, and the aesthetics of the sintered body as a dental material is less likely to deteriorate, which is more preferable.
  • the calcined body can be uniformly controlled, so the light transmittance and linear light transmittance after firing can be improved. can be maintained at a high level, and it is also possible to prevent coarsening of the grain size in the crystal structure in the sintered body, thereby enabling densification. From the above points, it is particularly preferable that the alumina particles contained in the calcined body of the present invention contain ⁇ -alumina with a purity of 99.5% or more.
  • the alumina raw material can be obtained, for example, by the alkoxide method, modified Bayer method, ammonium alum thermal decomposition method, ammonium dawsonite thermal decomposition method, etc., preferably by the alkoxide method.
  • the alkoxide method the purity of the alumina raw material powder can be increased and the particle size distribution can be made uniform.
  • alumina raw material examples include AKP grade ( ⁇ -alumina) manufactured by Sumitomo Chemical Co., Ltd., and NXA grade (“NXA-100”, “NXA-150”, etc.) (both are ultrafine ⁇ -alumina), etc. and ⁇ -alumina with a purity of 99.99% or more.
  • the alumina calcined body of the present invention preferably contains the sintering aid from the viewpoint of increasing the strength after sintering and particularly from the viewpoint of achieving high aesthetics.
  • the content of the sintering aid or pigment in the calcined body of the present invention and its sintered body can be determined, for example, by inductively coupled plasma (ICP) emission spectrometry, fluorescent X-ray analysis (XRF), scanning type Alternatively, it can be measured by a transmission electron microscope (SEM or TEM) and energy dispersive X-ray analysis or wavelength dispersive X-ray analysis (EDX or WDX), or field emission electron beam microanalysis (FE-EPMA). .
  • ICP inductively coupled plasma
  • XRF fluorescent X-ray analysis
  • SEM or TEM transmission electron microscope
  • EDX or WDX wavelength dispersive X-ray analysis
  • FE-EPMA field emission electron beam microanalysis
  • a dental alumina calcined in which a linear light transmittance of a sintered compact with a thickness of 1.0 mm fired under atmospheric pressure is 0.8% or more without using hot isostatic pressing treatment. body.
  • the measuring method and preferred range of the linear light transmittance are the same as those for the linear light transmittance of the alumina sintered body, which will be described later.
  • the linear light transmittance of a sintered body having a thickness of 1.0 mm obtained by firing a calcined dental alumina calcined body under atmospheric pressure without using hot isostatic pressing is preferably 0.8% or more. , more preferably 1% or more, more preferably 1.1% or more.
  • a sintered compact with a thickness of 1.2 mm fired under atmospheric pressure without hot isostatic pressing has a b* value of -8.0 to 14.2.
  • Alumina calcined body for The b* value is preferably -8.0 to 14.2, more preferably -7.0 to 14.0, and even more preferably -6.0 to 13.8.
  • the b* value is preferably 0 to 14.0, more preferably 0.1 to 13.9, even more preferably 0.2 to 13.8.
  • the method for measuring the b* value is the same as that for the b* value of the alumina sintered body, which will be described later.
  • the composition for producing the calcined body of the present invention (hereinafter also referred to as "alumina composition") will be described.
  • the alumina composition contains alumina, a blue colorant and a sintering aid.
  • Alumina, blue colorant and sintering aid are the same as those exemplified for the alumina calcined body.
  • the alumina composition serves as a precursor of the alumina calcined body of the present invention described above. Since the alumina composition and the molded body are those before sintering, it means that the alumina particles are not necked (fixed).
  • the content of alumina, blue colorant, and sintering aid in the alumina composition of the present invention is calculated from the content of a given alumina calcined body, and the content of the alumina composition and the alumina calcined body are the same. is.
  • the form of the alumina composition of the present invention is not limited, and includes powder, a fluid obtained by adding powder to a solvent, and a compact obtained by molding powder into a predetermined shape.
  • the alumina composition of the present invention may be an aggregate of granules. Granules are formed by agglomeration of primary particles.
  • primary particles refer to the smallest unit of bulk.
  • primary particles refer to spherical shapes in an electron microscope (eg, scanning electron microscope).
  • Primary particles include alumina particles.
  • alumina particles and sintering aid particles are included.
  • the particles constituting the granules made of the alumina composition are mainly primary particles.
  • Aggregated primary particles are called secondary particles.
  • the number of primary particles is preferably greater than the number of secondary particles. Since the secondary particles usually have an irregular shape, if there are many secondary particles, the coarseness and density will occur during press molding, which will be described later.
  • the particle size of the primary particles constituting the granules of the alumina composition affects the degree of adhesion during calcination, and affects the hardness of the calcined body. If the average primary particle diameter of the particles is less than 30 nm, the surface area of the primary particles contained in the calcined body is reduced, which increases the adhesion and increases the hardness during machining, which will be described later. On the other hand, if it is larger than 300 nm, particles with a small particle size distribution tend to be sucked in, causing local sticking due to the difference in particle size, which tends to cause coarseness and density, which is not preferable.
  • the average primary particle diameter of the particles is preferably from 30 to 300 nm, more preferably from 40 to 250 nm, even more preferably from 60 to 200 nm.
  • alumina particles having different average primary particle sizes may be mixed and used.
  • NXA a mixture of NXA-100 (ultra-fine ⁇ -alumina, manufactured by Sumitomo Chemical Co., Ltd.) and NXA-150 (ultra-fine ⁇ -alumina, manufactured by Sumitomo Chemical Co., Ltd.) can be used.
  • the BET specific surface area of the particles constituting the granules made of the alumina composition is preferably 5 m 2 /g or more, and 7.5 m 2 /g or more when measured in accordance with JIS Z 8830:2013. is more preferable, and 8 m 2 /g or more is even more preferable.
  • it is 5 m 2 /g or more, the sinterable temperature is easily lowered, sintering is facilitated, or the sintered body obtained after sintering becomes cloudy and the decrease in translucency is easily suppressed. .
  • the BET specific surface area is preferably 25 m 2 /g or less, more preferably 22 m 2 /g or less, and even more preferably 18 m 2 /g or less.
  • the average primary particle size is not too small, it is possible to suppress the occurrence of coarseness and density in the calcined body, and the aesthetic appearance after sintering is excellent.
  • the calcined body does not become too hard, and the amount of tool wear due to wear (hereinafter also referred to as “tool wear amount”) and / or chipping rate can be easily reduced. Otherwise, it is possible to suppress the occurrence of coarseness and fineness without too little sticking, and it is easy to reduce the chipping rate.
  • the "BET specific surface area” is a specific surface area that is measured without distinguishing between primary particles and secondary particles.
  • the numerical difference obtained by subtracting the BET specific surface area of the calcined body from the BET specific surface area of the composition is within 10 m 2 /g. Adhesion to a certain degree is preferable because good machinability and grindability can be maintained.
  • alumina composition of the present invention 50% or more, preferably 70% or more, more preferably 80% or more, and still more preferably 90% or more of alumina can take the form of granules.
  • the alumina particles constituting the powder should have the above average particle size and BET specific surface area.
  • the average particle size (secondary particle size, hereinafter also referred to as “average particle size”) of the granules in the alumina composition of the present invention is preferably 10 ⁇ m or more, more preferably 12 ⁇ m or more, and 14 ⁇ m or more. is more preferred. If the average granule diameter is less than 10 ⁇ m, air is entrapped when the granules are put into a mold, and degassing becomes insufficient during molding, which may make it impossible to produce a uniform and dense molded product. In addition, there is a possibility that granules may be ejected from gaps during molding, resulting in the production of a molded article that does not meet the predetermined required amount.
  • the average particle size is preferably 200 ⁇ m or less, more preferably 190 ⁇ m or less, even more preferably 180 ⁇ m or less, particularly preferably 150 ⁇ m or less, most preferably 100 ⁇ m or less.
  • the average granule diameter exceeds 200 ⁇ m, cavities are likely to be formed inside the granules. Also, when the granules are put into a mold, gaps are likely to occur. Due to these phenomena, degassing becomes insufficient during molding, and there is a risk that a dense molded body cannot be produced. In addition, shrinkage increases during molding, and there is a risk that a molded article having a desired size cannot be produced.
  • the alumina in the alumina composition constitute granules.
  • the average granule size is preferably measured in such a way that the granules are not broken.
  • the average granule size can be measured, for example, by a dry sieving method or a wet sieving method.
  • the dry sieving method can be measured according to the sieving test method described in JIS Z 8815:1994, manual sieving and mechanical sieving can be used, and mechanical sieving is preferred.
  • a sieve used in the sieving method a sieve described in JIS Z 8801-1:2019 test sieve can be used.
  • a low-tap sieve shaker or a sonic vibration sieving measuring device can be used as a measuring device used for the sieving method.
  • the low-tap sieve shaker include “RPS-105M” manufactured by Seishin Enterprise Co., Ltd., and the like.
  • the sonic vibration sieving instrument include "Robot Shifter RPS-01” and “Robot Shifter RPS-02” manufactured by Seishin Enterprise Co., Ltd.
  • the sphericity of the granules in the alumina composition of the present invention is preferably high.
  • By increasing the sphericity of the granules mixing at the interfaces between the layers can be caused when alumina powders with different compositions are layered.
  • the higher the sphericity the higher the packing density.
  • the strength and translucency of the sintered body can be increased by filling alumina granules into a specific mold (mold, etc.) and increasing the packing density, which is the density of a molded body formed into a specific shape by pressure. In addition, even if the mold has corners, it is possible to improve the filling of the corners with the granules.
  • the sphericity of the granules in the alumina composition of the present invention can be expressed, for example, by light bulk density, heavy bulk density, and the like.
  • the light bulk density of the alumina composition of the present invention is preferably 0.6 g/cm 3 or more from the viewpoint of good flow of granules (ease of clogging) for reducing coarseness and fineness of the resulting compact. It is more preferably 0.7 g/cm 3 or more, still more preferably 0.8 g/cm 3 or more, and particularly preferably 0.9 g/cm 3 or more.
  • the light bulk density can be measured according to JIS R 9301-2-3:1999.
  • the stacked bulk density of the alumina composition of the present invention is preferably 0.8 g/cm 3 or more from the viewpoint of good flow of granules (ease of clogging) for reducing coarseness and fineness of the resulting compact. It is more preferably 0.9 g/cm 3 or more, and even more preferably 1.0 g/cm 3 or more.
  • the bulk density can be measured according to JIS R 9301-2-3:1999.
  • the alumina composition of the present invention preferably contains a binder.
  • binder examples include organic binders.
  • organic binders include commonly used acrylic binders, acrylic acid binders, paraffin binders, fatty acid binders, polyvinyl alcohol binders, and the like. Among these organic binders, those having a carboxyl group in the molecular chain or carboxylic acid derivatives are preferred, acrylic binders are more preferred, and water-soluble polyacrylates are even more preferred.
  • the polyacrylic acid salt may be a copolymer of acrylic acid or methacrylic acid and maleic acid, or may contain sulfonic acid, and cations of the salt include sodium, ammonium, and the like.
  • the distance between primary particles in the alumina composition can be adjusted, the cumulative distribution of pores can be adjusted, and the Vickers hardness or the strength of the calcined body can be increased or decreased. becomes easier.
  • the content of the binder is preferably 1.2 to 2.8% by mass, more preferably 1.5 to 2.5% by mass, and even more preferably 1.8 to 2.2% by mass in the entire alumina composition. .
  • the strength of the calcined body is not too high, and there is no risk of the machined body becoming hard when it is removed. Further, when the content is 2.8% by mass or less, the strength of the calcined body does not decrease excessively, the possibility of the workpiece falling off during cutting can be reduced, and the chipping rate can be easily reduced.
  • the alumina composition of the present invention may optionally contain a colorant other than the blue colorant (including pigments, composite pigments and fluorescent agents), titanium oxide (TiO 2 ), and silica.
  • a colorant other than the blue colorant including pigments, composite pigments and fluorescent agents
  • titanium oxide (TiO 2 ) titanium oxide
  • silica silica
  • Additives (except CeO2 , ZrO2 and Y2O3 ) other than sintering aids such as ( SiO2 ), dispersants, antifoaming agents can be included. These components may be used individually by 1 type, and may be used in mixture of 2 or more types.
  • the pigment may be other than the blue colorant.
  • Examples include Ti, V, Cr, Mn, Fe, Ni, Zn, Y, Zr, Sn, Sb, Bi, Ce, Sm, Eu, Gd, and Er oxides of at least one element selected from the group.
  • Examples of the composite pigment include (Zr, V) O 2 and Fe(Fe, Cr) 2 O 4 .
  • Examples of the fluorescent agent include Y2SiO5 :Ce, Y2SiO5 :Tb, ( Y, Gd ,Eu) BO3 , Y2O3 : Eu, YAG:Ce, ZnGa2O4 : Zn , BaMgAl 10 O 17 :Eu and the like.
  • the additives may be added during mixing or pulverization, or may be added after pulverization.
  • One embodiment includes a dental mill blank containing the alumina calcined body as a part thereof. Since the dental mill blank partially contains the alumina calcined body, the alumina calcined body has high translucency and high linear light transmittance after sintering. The high aesthetics required for the incisal can be achieved without being supplemented with other materials (eg, porcelain). The location in the portion of the dental mill blank is not specified as it can be adjusted during processing.
  • Another embodiment includes a dental mill blank, wherein the portion is the portion with the highest translucency. Since the portion has the highest translucency, processing the portion as an incisal edge of an incisor or a canine can provide particularly high aesthetics. The location in the portion of the dental mill blank is not specified as it can be adjusted during processing.
  • a method for producing a dental alumina calcined body comprising: including a step of uniformly fixing the blue colorant to the alumina particles;
  • the dental alumina calcined body contains alumina particles having an average primary particle size of 30 to 300 nm, a sintering aid, and a blue colorant,
  • the step of uniformly fixing a blue colorant (e.g., cobalt component) to alumina particles includes a step of dispersing ⁇ -alumina particles in a dispersion medium in which the blue colorant is dissolved.
  • a blue colorant e.g., cobalt component
  • the dispersion medium is not particularly limited, and for example, an organic solvent (alcoholic solvent such as methanol, ethanol, etc.) can be used.
  • a dispersion medium may be used individually by 1 type, and may use 2 or more types together.
  • the method for producing a dental alumina calcined body may include a step of press-molding the alumina composition to obtain a molded body.
  • an alumina calcined body for example, a step of producing an alumina composition containing alumina particles, a blue coloring agent, and a sintering aid, and producing the alumina composition (for example, a compact) Firing (calcination) to obtain an alumina calcined body in which the average primary particle diameter of the alumina particles contained in the calcined body is 30 to 300 nm and the content of the sintering aid is 10 to 5000 ppm. and a manufacturing method including steps.
  • the manufacturing process of the alumina composition of the present invention will be described.
  • alumina and a sintering aid are mixed in a predetermined ratio to prepare a mixture (mixing step).
  • the sintering aid is magnesium chloride
  • the mixing ratio of alumina and magnesium chloride can be mixed so as to achieve the above content.
  • Mixing may be dry mixing or wet mixing.
  • the alumina composition can be pulverized (preferably pulverized) to the above average particle size (pulverization step).
  • the mixing process and the crushing process can be performed in the same process.
  • Pulverization can be performed, for example, by using a ball mill, bead mill, etc. after dispersing the composition and binder in a solvent such as water or alcohol (dispersion step), and the average primary particle size of the composition is, for example,
  • the composition is pulverized (preferably pulverized) to a size of 0.05 ⁇ m to 0.3 ⁇ m.
  • the composition may be subjected to other treatments (classification treatment, water treatment) in order to adjust the particle size.
  • the average primary particle size can be measured by a laser diffraction/scattering particle size distribution measurement method. For example, using a laser diffraction/scattering particle size distribution analyzer (trade name "Partica LA-950") manufactured by Horiba, Ltd., a slurry diluted with water is subjected to ultrasonic irradiation for 30 minutes, and then ultrasonic waves are applied. It can be measured by volume while applying.
  • a laser diffraction/scattering particle size distribution analyzer (trade name "Partica LA-950”) manufactured by Horiba, Ltd., a slurry diluted with water is subjected to ultrasonic irradiation for 30 minutes, and then ultrasonic waves are applied. It can be measured by volume while applying.
  • the mixture can be spray-dried with a spray dryer or the like to make the alumina composition into the granule form as described above (drying step).
  • the average particle size of the alumina composition is preferably 0.3 ⁇ m or less, more preferably 0.25 ⁇ m or less, further preferably 0.2 ⁇ m or less, and 0.15 ⁇ m or less. is particularly preferred.
  • the average particle size of the alumina composition is preferably 0.3 ⁇ m or less, more preferably 0.25 ⁇ m or less, further preferably 0.2 ⁇ m or less, and 0.15 ⁇ m or less. is particularly preferred.
  • the average particle size of the alumina composition is preferably 0.3 ⁇ m or less, more preferably 0.25 ⁇ m or less, further preferably 0.2 ⁇ m or less, and 0.15 ⁇ m or less. is particularly preferred.
  • the alumina and sintering aid may be prepared separately.
  • the alumina and the sintering aid are not precipitated at the same time (in the same process), but the alumina preparation process (e.g., manufacturing process) and the sintering aid preparation process (e.g., manufacturing process) are independent of each other. It may also be a separate step.
  • the above-described ⁇ -alumina can be obtained with high purity and a small primary particle size.
  • a sintering aid may be reacted with alumina by heat treatment, and the pulverization and drying steps may be performed using it.
  • Granules or powder can be formed into a compact by applying an external force.
  • the molding method is not limited to a specific method, and a suitable method can be selected according to the purpose.
  • it can be molded by press molding, injection molding, stereolithography, slip casting, gel casting, filter filtration, casting, and the like.
  • you may perform multistep shaping
  • the alumina composition may be press-molded and then CIP-treated, or the press-molding and CIP-molding may be repeated.
  • press molding methods include uniaxial pressing (hereinafter also referred to as “uniaxial pressure pressing”) processing, biaxial pressing processing, CIP (Cold Isostatic Pressing) processing, and the like. These may be performed in combination as appropriate.
  • the molded article of the present invention can have a disk shape, a cuboid shape, or a dental product shape (for example, a crown shape).
  • the pressure molding is a uniaxial press
  • the surface pressure in the uniaxial press is 5 MPa or more.
  • it may be a columnar compact formed by filling a mold with alumina granules and compacting it with a uniaxial press.
  • the higher the contact pressure in press molding the higher the density of the molded product.
  • the surface pressure of press molding is preferably 5 to 600 MPa, more preferably 10 to 400 MPa, even more preferably 15 to 200 MPa.
  • the surface pressure of the press is 5 MPa or more, the shape retention of the molded body is excellent.
  • the molded body of the present invention also includes a molded body densified by high-temperature pressure treatment such as CIP (Cold Isostatic Pressing) treatment.
  • the water pressure is preferably 50 to 1000 MPa, more preferably 100 to 600 MPa, and even more preferably 150 to 300 MPa from the same viewpoint as above.
  • the alumina calcined body according to the present invention is a precursor (intermediate product) of the alumina sintered body according to the present invention, which will be described later.
  • the calcined body also includes a molded body.
  • the alumina calcined body according to the present invention includes, for example, a dental product (for example, a crown-shaped prosthesis) obtained by processing a calcined alumina disc with a CAD/CAM (Computer-Aided Design/Computer-Aided Manufacturing) system. .
  • the contents of alumina and sintering aid in the alumina calcined body of the present invention are the same as the contents in the alumina composition before the alumina calcined body is produced.
  • the stabilizer is preferable because the magnesium compound is uniformly dispersed.
  • the sintering temperature (hereinafter also referred to as “calcining temperature”) in the step of sintering under atmospheric pressure (calcining step) in the method for producing a calcined body affects the Vickers hardness or the strength of the calcined body.
  • the calcination temperature changes the cumulative distribution and hardness of the pores of the calcined body, and changes the tool wear amount and/or the chipping rate.
  • the calcination temperature (maximum calcination temperature) in the method for producing an alumina calcined body of the present invention is preferably 600° C. or more and 1200° C. or less, more preferably 650° C. or more and 1100° C. or less from the above viewpoint. , 700° C. or higher and 1000° C. or lower.
  • the calcining temperature is 600 ° C. or higher
  • a support support or In addition to preventing the workpiece from falling off during cutting or grinding, the Vickers hardness can be adjusted to a desired range to suppress an increase in the chipping rate.
  • the calcining temperature is 1200° C. or less
  • the adhesion does not proceed too much, so that the workpiece does not become too hard, and it does not take time to separate the workpiece from the frame fixing the workpiece, and Also, since wear of the tool does not increase, an increase in the chipping rate can be suppressed, and the workpiece can be easily separated from the support.
  • Holding the calcined body at the maximum calcining temperature for a certain period of time is preferable because the hardness of the calcined body falls within the preferable range and the chipping rate may decrease.
  • the calcining conditions depend on the average primary particle size of the calcined body and the density of the calcined body, but the holding time at the maximum calcining temperature is preferably 30 minutes to 6 hours. Further, the rate of temperature increase to the maximum calcination temperature and the rate of temperature decrease from the maximum calcination temperature are preferably 300° C./min or less.
  • the alumina calcined body of the present invention can be machined to produce a processed body.
  • the processing method is not limited to a specific method, and a suitable method can be appropriately selected depending on the purpose.
  • an alumina disc which is also a calcined body, can be cut or ground into the shape of a dental product (eg, a crown-shaped prosthesis) using a CAD/CAM system to produce a processed body.
  • the processed body may be improved in surface smoothness with a tool such as an abrasive material (for example, Pearl Surface (registered trademark), manufactured by Kuraray Noritake Dental Co., Ltd.).
  • a tool such as an abrasive material (for example, Pearl Surface (registered trademark), manufactured by Kuraray Noritake Dental Co., Ltd.).
  • the relative density of the calcined body of the present invention can be controlled by the manufacturing method described below. If the relative density is less than 43%, it means that the ratio of pores inside the calcined body is high, and the relative density inside the calcined body becomes uneven and the chipping increases. Furthermore, due to this sparseness and density, the shrinkage ratio during sintering becomes uneven, and the sintered body is deformed to some extent, which increases the need for rework. From the aesthetic point of view of the sintered body, if the relative density is sparse, workability such as cutting and grinding may be improved. This means that the distance is long, and since the voids cannot be discharged out of the sintered body during the sintering process, the aesthetic appearance of the sintered body is deteriorated, which is not preferable.
  • the relative density is 43% or more and 63% or less, the overall balance between particles and pores is good, the amount of tool wear and / or chipping rate can be reduced, and the aesthetic appearance of the sintered body can be maintained at a high level.
  • 43% to 63% is preferred, and 50% to 55% is more preferred.
  • the relative density of the calcined body can be calculated from the porosity of the calcined body, and specifically can be measured and calculated using a mercury porosimeter.
  • a mercury porosimeter device a device capable of applying a mercury pressure of 15 to 30,000 psia is preferable, and a device capable of applying a pressure of 0.5 to 60,000 psia is more preferable. From the viewpoint of reducing measurement errors, the pressure resolution is preferably 0.1 psia or more.
  • Mercury porosimeter devices include, for example, AutoPore (registered trademark) IV9500 manufactured by Micromeritics (USA).
  • the density of the calcined body is determined by filling the granules obtained by drying the raw material into a specific mold (mold, etc.), applying pressure to the molded body in a specific shape, and heating it at a temperature at which the binder can be removed to remove the binder. It means the density of a calcined body obtained by heating at a temperature at which yttria is moderately solid-dissolved and necking (adhesion) is formed moderately.
  • the temperature at which the binder is removed is not particularly limited as long as it is a temperature at which the binder can be removed, and may be 150 to 500.degree.
  • the temperature at which necking (sticking) is properly formed is preferably 700 to 1200°C.
  • the BET specific surface area of the calcined body of the present invention varies depending on the average primary particle size, adherence state, and density.
  • the BET specific surface area can be measured according to JIS Z 8830:2013.
  • the BET specific surface area is measured using a commercially available product such as a fully automatic specific surface area measuring device (trade name "Macsorb (registered trademark) HM model-1200", BET flow method (single-point method/multi-point method), manufactured by Mountec Co., Ltd.). can be measured
  • the BET specific surface area of the calcined body of the present invention is preferably 5 m 2 /g or more, more preferably 7.5 m 2 /g or more, from the viewpoint of increasing or decreasing the amount of tool wear and chipping rate. More preferably, it is 8 m 2 /g or more.
  • the BET specific surface area is 5 m 2 /g or more, the average primary particle size is not too large, and an increase in the chipping rate can be suppressed, or excessive adhesion does not occur, so an increase in the amount of tool wear can be suppressed.
  • the BET specific surface area is preferably 25 m 2 /g or less, more preferably 22 m 2 /g or less, even more preferably 18 m 2 /g or less.
  • the average primary particle size is not too small, the calcined body does not become too hard, and the tool wear amount and / or chipping rate is easily reduced, or , it is possible to suppress the occurrence of coarseness and fineness without too little sticking, and it is easy to reduce the chipping rate.
  • the workability of the calcined body of the present invention is also affected by the strength of the calcined body.
  • the strength of the calcined body according to the present invention can be evaluated, for example, by measuring the bending strength of the calcined body.
  • the three-point bending strength of the calcined body according to the present invention can be measured according to JIS R 1601:2008.
  • the three-point bending strength of the calcined body is preferably 10 MPa or more, more preferably 18 MPa or more, and further preferably 20 MPa or more, in order to ensure the strength that enables mechanical processing. preferable. If the three-point bending strength of the calcined body is less than 10 MPa, the post (support or sprue) breaks during cutting or grinding, and the processed body falls off from the calcined body before it becomes a cut or ground body. more likely to get lost.
  • the three-point bending strength of the calcined body is preferably 50 MPa or less, more preferably 45 MPa or less, further preferably 40 MPa or less, and 35 MPa. The following are particularly preferred.
  • the Vickers hardness of the calcined body of the present invention is easy from the viewpoint of reducing the amount of tool wear or chipping, and when separating the cut or ground processed body from the fixing frame, suppressing tool wear and short
  • the Vickers hardness is 350 HV 5/30 or less, preferably 300 HV 5/30 or less, more preferably 100 HV 5/30 or less, because it can be separated in time.
  • the Vickers hardness is less than 30 HV 5/30, the chipping occurrence rate increases, and when it exceeds 135 HV 5/30, the amount of tool wear increases.
  • "HV 5/30” means the Vickers hardness when a load (test force) of 5 kgf is held for 30 seconds.
  • the calcined body of the present invention has a Vickers hardness within the above-described predetermined range, it is possible to reduce the probability of chipping.
  • the method for measuring the Vickers hardness in the present invention conforms to JIS Z 2244:2020, and will be described in detail in Examples below.
  • the Vickers hardness of the calcined body of the present invention is easily achieved by the average primary particle size of the particles contained in the calcined body, the relative density of the calcined body, and the strength of the calcined body depending on the state of adhesion of the particles. Also, in order to achieve these factors, the method for producing the calcined body and the composition is important. , the surface pressure during the production of the compact, and the calcination temperature during the production of the calcined body are important. These will be described below.
  • the machine used for machining the calcined body of the present invention is not particularly limited.
  • the cutting or grinding machine may be a desktop machine, a large machining center (general-purpose machine), or the like, depending on the object to be machined.
  • a cutting machine for example, desktop machines "DWX-50”, “DWX-4”, “DWX-4W”, “DWX-52D”, “DWX-52DCi” (manufactured by Roland DG Co., Ltd.) etc.
  • the tools used in the processing machine used for machining the calcined body of the present invention are not particularly limited. Milling burs and grinding burs recommended by the supplier of the processing machine can be suitably used.
  • milling burs used in cutting machines include Katana (registered trademark) drills.
  • the tools used in machining machines have a lifespan that depends on the conditions of use. For example, when cutting or grinding a calcined body, if the drill edge wears (tool wear), the machined surface of the calcined body may crack finely (chipping) or crack greatly, resulting in re-machining. As a result, productivity problems such as time-consuming problems arise. In particular, conventional calcined bodies are prone to chipping.
  • the torque may be detected on the machine side, and a certain torque value may be used as the tool life judgment index (tool replacement judgment index) with a certain torque value as the upper limit of the threshold value. Moreover, it is good also considering processing time as a threshold upper limit.
  • the tool life can be confirmed by measuring the wear width of the cutting edge of a milling bur for a cutting or grinding machine, for example. For example, in the case of a Katana (registered trademark) drill, it can be determined that the wear width of 0.21 mm or more has reached the end of its service life (replacement time).
  • the wear width of the blade is preferably within 0.2 mm. Within 0.15 mm is more preferable, and within 0.1 mm is even more preferable.
  • the alumina sintered body of the present invention can be produced by sintering the alumina calcined body of the present invention and its cut or ground body at a temperature at which the alumina particles are sintered (sintering step).
  • the sinterable temperature (for example, maximum sintering temperature) is preferably 1300° C. or higher, and can be changed according to the average primary particle size.
  • the sinterable temperature e.g., maximum sintering temperature
  • the sinterable temperature is, for example, preferably 1500° C. or lower, more preferably 1450° C. or lower. It is preferable that the rate of temperature increase and the rate of temperature decrease be 300° C./min or less.
  • the holding time at a sinterable temperature is preferably less than 120 minutes, more preferably 90 minutes or less, and further preferably 75 minutes or less. It is preferably 60 minutes or less, particularly preferably 45 minutes or less, and most preferably 30 minutes or less.
  • the holding time is preferably 1 minute or longer, more preferably 3 minutes or longer, and even more preferably 5 minutes or longer.
  • the time of the sintering process for producing the sintered body is shortened without reducing the translucency and strength of the produced alumina sintered body. be able to.
  • the holding time at the maximum sintering temperature for producing the sintered body can be shortened (short-time sintering).
  • the production efficiency can be increased, and when the alumina calcined body of the present invention is applied to a dental product, the dimensions of the dental product to be used for treatment are determined, and after cutting or grinding, the It is possible to shorten the time until treatment with dental products is possible, and to reduce the time burden on the patient. Also, energy costs can be reduced.
  • the holding time at the sinterable temperature (for example, the maximum sintering temperature) can be, for example, 25 minutes or less, 20 minutes or less, or 15 minutes or less.
  • the heating rate can be set so as to reach the maximum sintering temperature in the shortest time according to the performance of the kiln.
  • the heating rate to the maximum sintering temperature is, for example, 10°C/min or more, 50°C/min or more, 100°C/min or more, 120°C/min or more, 150°C/min or more, or 200°C/min or more. can do.
  • the cooling rate from the maximum sintering temperature it is preferable to set the cooling rate from the maximum sintering temperature to such a rate that the sintered body does not deform due to the difference in shrinkage rate and defects such as cracks do not occur.
  • the sintered body can be allowed to cool at room temperature.
  • the alumina sintered body obtained by sintering the alumina calcined body or its processed body of the present invention will be described.
  • the alumina sintered body is, for example, alumina particles (powder) that have reached a sintered state.
  • the relative density of the alumina sintered body is preferably 99.5% or more.
  • the relative density of the sintered body can be calculated as the ratio of the actual density measured by the Archimedes method to the theoretical density.
  • the relative density is the density d1 of a sintered body obtained by filling a specific mold with granules and applying pressure to a specific shape, and sintering the compact at a high temperature. It means the value divided by the density d2.
  • the alumina sintered body of the present invention includes not only a sintered body obtained by sintering molded alumina particles under normal pressure and under no pressure, but also a sintered body densified by high temperature pressure treatment such as HIP treatment. included.
  • the relative density of the alumina sintered body of the present invention the higher the density, the fewer internal voids and the less light scattering. As a result, the alumina sintered body of the present invention has high translucency ( ⁇ L), total light transmittance, and linear light transmittance, and is excellent in aesthetics and also in strength.
  • the relative density of the alumina sintered body is preferably high.
  • the relative density of the alumina sintered body of the present invention is, for example, preferably over 95%, more preferably 98% or more, and even more preferably 99.5% or more.
  • the alumina sintered body of the present invention contains substantially no voids.
  • the average crystal grain size contained in the alumina sintered body of the present invention is preferably small because the smaller the sintered body, the higher the linear light transmittance of the sintered body.
  • the average crystal grain size contained in the alumina sintered body is preferably 0.3 to 8.0 ⁇ m. Further, the average crystal grain size is more preferably 5 ⁇ m or less, still more preferably 3 ⁇ m or less, even more preferably 2 ⁇ m or less, and particularly preferably 1 ⁇ m or less.
  • the average crystal grain size contained in the alumina sintered body of the present invention is 0.3 to 8.0 ⁇ m, the strength, translucency ( ⁇ L), and / or total light transmittance are increased. preferable.
  • the average grain size of the alumina sintered body can be measured by the method described in Examples below.
  • the linear light transmittance at a thickness of 1.0 mm of the alumina sintered body of the present invention is preferably 0.8% or more, more preferably 1% or more, and further preferably 1.1% or more. . If the linear light transmittance at a thickness of 1.0 mm of the alumina sintered body is less than 0.8%, it is possible that the translucency (transparency of linear light) required for the incisal portion of the dental prosthesis cannot be obtained.
  • the method for measuring the linear light transmittance of the alumina sintered body is as described in Examples below.
  • the linear light transmittance at a thickness of 1.0 mm of the alumina sintered body of the present invention is preferably 20% or less, more preferably 18% or less, further preferably 16% or less. % or less is particularly preferred. If the linear light transmittance at a thickness of 1.0 mm of the alumina sintered body exceeds 20%, the translucency of the incisal portion of the dental prosthesis (transparency of linear light) is too high, and the tip portion of the tooth (incisal end) suitable esthetics may not be obtained.
  • alumina, blue colorant, and sintering aid in the alumina sintered body of the present invention are the same as those in the composition and/or the calcined body before producing the sintered body.
  • the translucency ( ⁇ L) of the alumina sintered body of the present invention is preferably 5 or more, more preferably 10 or more, further preferably 15 or more, and particularly preferably 20 or more.
  • the translucency ( ⁇ L) here refers to the L* value of lightness (color space) in the L*a*b* color system (JIS Z 8781-4: 2013) of a sample with a thickness of 1.2 mm.
  • the L* value measured with a white background is the first L* value
  • the L* value measured with the background of the sample black is the second L* value for the same sample for which the first L* value was measured.
  • * value which is the value obtained by subtracting the second L* value from the first L* value.
  • composition granules (composition) were press-molded so that the thickness of the sintered body was 1.2 mm, followed by CIP molding. For example, a disk-shaped compact with a diameter of 19 mm can be produced. Next, the molded body is fired under predetermined firing conditions, and the surface is polished with #2000 to prepare a sintered body having a thickness of 1.2 mm as a sample.
  • a color difference meter for example, CE100, analysis software "Crystal Eye” (manufactured by Olympus Co., Ltd.)
  • nD refractive index
  • 589 nm sodium D line
  • the b* value is preferably -8.0 to 14.2, more preferably -7.0 to 14.0, and even more preferably -6.0 to 13.8.
  • the b* value is preferably 0 to 14.0, more preferably 0.1 to 13.9, even more preferably 0.2 to 13.8.
  • the method for measuring the b* value is as described in Examples below.
  • the alumina sintered body of the present invention may be a molded body having a predetermined shape.
  • the sintered body can have a disk shape, cuboid shape, dental product shape (eg crown shape).
  • the alumina composition, granules, powders, compacts, calcined bodies, cut or ground bodies, and sintered bodies according to the present invention are not limited to the above unless otherwise specified, and are known. Various manufacturing methods are applicable.
  • the present invention includes embodiments in which the above configurations are combined in various ways within the scope of the technical idea of the present invention as long as the effects of the present invention are exhibited.
  • the upper limit and lower limit of the numerical range content of each component, each element (average primary particle size, etc.), each physical property, etc.) can be combined as appropriate.
  • the alumina calcined body of the present invention is suitable for alumina processed products that require high transparency after firing, such as dental materials, optical fiber cable connectors, smartphone housings, semiconductors, jigs for liquid crystal manufacturing, separation membranes, and transparency for high-pressure sodium lamps. It can be suitably used for optical tubes, clock windows, abrasives for magnetic tapes, display materials, battery electrode materials, and the like. Among them, it is suitable for applications that require precise machining at the stage of the calcined body, and is particularly preferable for dental applications because workability, translucency, and strength are required.
  • a degeneracy filter is applied to the region, each region is degenerated to one or more points, and the Voronoi polygons are generated so that these points become the generating points of the Voronoi polygons.
  • FIG. 1 shows an electron micrograph of the calcined body according to Example 1. As shown in FIG.
  • the physical distance between one maximum value and the minimum value around that maximum value in the waveform of the detected amount of the elements constituting the pigment obtained by line analysis is By calculating the average value between the maximum value and the minimum value that match, the physical distance of the concentration difference of the elements constituting the pigment was obtained.
  • the number of fields of view was changed so that a total of 20 fields of view, ie, 10 fields of view ⁇ 2 fields of view, were connected, and the line analysis distance was set to 50 ⁇ m within the connected fields of view. Twenty points were analyzed, and the average value of the obtained waveforms was taken as the physical distance.
  • the dispersibility criterion was "O" when the physical distance was within 50 ⁇ m, and "X" when it exceeded 50 ⁇ m.
  • the crystal grain size obtained with Image-Pro Plus is obtained by measuring the length of the line segment connecting the contour lines passing through the center of gravity determined from the contour line of the crystal grain at 2-degree increments around the center of gravity and averaging them. It is a thing. In the SEM photographic images (three fields of view) of the alumina sintered body, the grain size of all the particles not covering the edge of the image was measured. The average crystal grain size was calculated from the obtained crystal grain size of each grain and the number of crystal grains, and the obtained arithmetic mean diameter was defined as the average crystal grain size in the sintered body.
  • particles that do not overlap the edges of the image means particles excluding particles whose outlines do not fit within the screen of the SEM photograph image (particles whose outlines are interrupted on the upper, lower, left, and right boundaries).
  • the grain size of all particles not overhanging the image edge was selected in Image-Pro Plus with the option to exclude all borderline particles.
  • the white background means the white part of the hiding rate test paper described in JIS K 5600-4-1:1999, Part 4, Section 1, and the black background means the black part of the hiding rate test paper.
  • the translucency ( ⁇ L) of the alumina sintered body is preferably 5 or more, more preferably 10 or more, even more preferably 15 or more, and particularly preferably 20 or more.
  • the obtained compact was heated from room temperature at a rate of 10°C/min and held at 500°C for 2 hours to degrease the organic component. Hold at 700° C. (when producing alumina calcined body) or 1000° C. (when producing zirconia calcined body) for 6 hours, and slowly cool at ⁇ 0.4° C./min to produce alumina calcined body and zirconia calcined body. Obtained.
  • alumina sintered bodies and zirconia calcined bodies were fired at the maximum sintering temperature shown in Table 2 for 2 hours to produce alumina sintered bodies and zirconia sintered bodies.
  • Both sides of the obtained alumina sintered body and zirconia sintered body were mirror-polished to form an alumina sintered body and a zirconia sintered body having a thickness of 1.0 mm, and then a turbidity meter (manufactured by Nippon Denshoku Industries Co., Ltd. , "Haze Meter NDH4000").
  • b * value [Measurement of chromaticity (b * value)]
  • the b * value was measured using a dental colorimetric device (“Crystal Eye CE100-DC/JP”, 7 band LED light source, manufactured by Olympus Corporation) and analysis software “Crystal Eye” (manufactured by Olympus Corporation).
  • * a * b * Colorimetric system JIS Z 8781-4: 2013 colorimetry-Part 4: CIE 1976 L * a * b * color space
  • Measure the chromaticity (color space) and use the b * value (average value of n 3).
  • An alumina sintered body and a zirconia sintered body having a diameter of 14 mm and a thickness of 1.2 mm were used for the measurement.
  • the b* value is preferably -8.0 to 14.2, more preferably -7.0 to 14.0, and even more preferably -6.0 to 13.8.
  • Example 1 ⁇ -alumina raw material NXA-100 (manufactured by Sumitomo Chemical Co., Ltd.) 100 g, magnesium chloride hexahydrate 0.83 g (equivalent to 1000 mass ppm as Mg element), and cobalt chloride hexahydrate 0.4 mg (as Co element) equivalent to 1 ppm by mass) was weighed, put into 0.7 L of ethanol, and ultrasonically dispersed. This and alumina beads were placed in a rotary container, and the alumina raw material containing agglomerated particles was mixed and pulverized by ball mill pulverization until the raw material had a desired average primary particle size.
  • the average primary particle size is measured by using a laser diffraction/scattering particle size distribution measuring device (trade name “Partica LA-950”) manufactured by Horiba, Ltd., and irradiating a slurry diluted with ethanol with ultrasonic waves for 30 minutes, and then , was measured on a volume basis while applying ultrasonic waves. A desired slurry with almost no secondary agglomeration was obtained with a ball milling time of about 1 hour.
  • a laser diffraction/scattering particle size distribution measuring device (trade name “Partica LA-950”) manufactured by Horiba, Ltd.
  • an organic binder was added to this slurry.
  • a water-based acrylic binder was used as the organic binder, and 2% by mass of the organic binder was added to the ⁇ -alumina raw material, and the mixture was stirred with a rotary blade for 24 hours.
  • the slurry after stirring was dried and granulated with a spray dryer to obtain granules.
  • the average particle size of the granules was 40 ⁇ m.
  • the powder composed of the granules was poured into a rectangular parallelepiped mold having a predetermined size and uniaxially pressed at a pressure of 150 MPa to obtain a compact.
  • the molded body is placed in an electric furnace, heated from room temperature at a rate of 10°C/min, and held at 500°C for 2 hours to degrease the organic components. was maintained for 6 hours and slowly cooled at -0.4°C/min to obtain a calcined body.
  • a processed body with a thickness of 1.5 mm is cut out by machining, the temperature is raised from room temperature at a rate of 10 ° C./min, and the maximum sintering temperature is 1400 ° C. under atmospheric pressure.
  • a sintered body was obtained by slowly cooling at ⁇ 0.4° C./min.
  • a calcined body and a sintered body were obtained in the same manner as in Example 1.
  • Example 6 100 g of ⁇ -alumina raw material NXA-100 (manufactured by Sumitomo Chemical Co., Ltd.), 0.83 g of magnesium chloride hexahydrate (equivalent to 1000 mass ppm as Mg element), and 8 mg of cobalt chloride hexahydrate (20 mass as Co element) ppm) was weighed, put into 0.7 L of ethanol, and ultrasonically dispersed.
  • This and alumina beads were placed in a rotating container, and the alumina raw material containing aggregated particles was mixed and pulverized by ball milling until the raw material had a desired average primary particle size.
  • the average primary particle size was measured using a laser diffraction/scattering particle size distribution analyzer (trade name “Partica LA-950”) manufactured by Horiba, Ltd., and the slurry diluted with ethanol was subjected to ultrasonic irradiation for 30 minutes. , was measured on a volume basis while applying ultrasonic waves. A desired slurry with almost no secondary agglomeration was obtained with a ball milling time of about 1 hour.
  • Example 6 The resulting slurry was stirred in a 2 L beaker with a rotor at 200 rpm for 1 hour, then the rotor was immediately stopped and allowed to stand for 15 minutes. It was visually confirmed that white particles had sunk to the bottom of the beaker, and the supernatant was also cloudy.
  • the slurry of Example 6 was obtained by sucking out the upper third of the slurry in the beaker.
  • Table 1 the main raw material of Example 6 is described as "NXA-100 on water", distinguished by the water treatment. The same procedure as in Example 1 was used to obtain a calcined body and a sintered body from this slurry.
  • ⁇ Comparative Example 1> A calcined body and a sintered body were obtained by using yttria-stabilized zirconia instead of NXA-100 as the ⁇ -alumina raw material. Yttria-stabilized zirconia was produced by the following method.
  • a mixture was prepared so that the content of yttria with respect to the total mol of zirconia and yttria was 5.5 mol %. made.
  • this mixture was added to water to prepare a slurry, which was wet pulverized and mixed with a ball mill until the average particle size was 0.13 ⁇ m or less.
  • the slurry after pulverization was dried with a spray dryer, and the obtained powder was fired at 950° C. for 2 hours to prepare a powder (primary powder).
  • the resulting primary powder was added to water to prepare a slurry, which was then wet pulverized and mixed with a ball mill until the average particle size was 0.13 ⁇ m or less. After adding a binder to the slurry after pulverization, it was dried with a spray dryer to produce a powder (secondary powder). The produced secondary powder was used as raw material powder for producing a zirconia calcined body of Comparative Example 1.
  • a method for manufacturing a zirconia calcined body will be described.
  • a mold with internal dimensions of 20 mm ⁇ 25 mm was filled with the raw material powder and uniaxially pressed at a pressure of 150 MPa to prepare a compact.
  • the obtained compact is placed in an electric furnace, heated from room temperature at a rate of 10° C./min, and held at 500° C. for 2 hours to degrease the organic components. C. for 6 hours and slowly cooled at -0.4.degree. C./min to obtain a zirconia calcined body.
  • a processed body with a thickness of 1.5 mm was machined from the calcined body, heated from room temperature at a rate of 10 ° C./min, and held at a maximum sintering temperature of 1550 ° C. for 2 hours. C./min to obtain a sintered body.
  • Example 3 A calcined body and a sintered body were obtained in the same manner as in Example 2 except that AA-03 (manufactured by Sumitomo Chemical Co., Ltd.) was used instead of NXA-100 as the ⁇ -alumina raw material.
  • Example 4 A calcined body and a sintered body were obtained in the same manner as in Example 2, except that magnesium chloride hexahydrate was not added as a sintering aid.
  • Example 5 A calcined body and a sintered body were obtained in the same manner as in Example 2, except that magnesium chloride hexahydrate as a sintering aid was changed to an equivalent of 10000 ppm by mass as Mg element.
  • Tables 1 and 2 show the results of each example and comparative example.
  • the dental alumina calcined body of the present invention By using the dental alumina calcined body of the present invention, it is possible to provide a dental alumina sintered body with high linear light transmittance and suppressed yellowness.
  • the dental alumina calcined body of the present invention is particularly suitable as a dental prosthesis for incisors or canines because it becomes an alumina sintered body with high aesthetics suitable for the appearance of incisions.

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WO2025105493A1 (ja) * 2023-11-16 2025-05-22 クラレノリタケデンタル株式会社 高透明かつ高強度の歯科用アルミナ仮焼体及びその焼結体並びにそれらの製造方法

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62260766A (ja) * 1986-05-08 1987-11-13 東レ株式会社 アルミナ焼結体
JP2000219570A (ja) * 1999-01-29 2000-08-08 Sumitomo Chem Co Ltd 透光性アルミナ焼結体の製造方法およびその用途
JP2002338336A (ja) * 2001-05-16 2002-11-27 Kobe Steel Ltd 摺動部用アルミナセラミックス製品およびその製造方法
JP2015533754A (ja) * 2012-08-20 2015-11-26 セラムテック ゲゼルシャフト ミット ベシュレンクテル ハフツングＣｅｒａｍＴｅｃ ＧｍｂＨ 酸化ジルコニウムベースの複合材
JP2016026986A (ja) * 2014-06-23 2016-02-18 東ソー株式会社 着色透光性ジルコニア焼結体と粉末、及びその用途
CN106619140A (zh) * 2016-11-16 2017-05-10 西安交通大学 一种氧化铝全瓷牙科修复材料及其制备方法
WO2019022194A1 (ja) * 2017-07-28 2019-01-31 住友化学株式会社 組成物、フィルム、積層構造体、発光装置、及びディスプレイ
US20220055948A1 (en) * 2020-08-21 2022-02-24 Ivoclar Vivadent Ag Aluminium Oxide Ceramic Material

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001213664A (ja) 2000-01-28 2001-08-07 Sumitomo Chem Co Ltd アルミナ焼結体とその製造方法およびその用途
US11795110B2 (en) 2017-12-26 2023-10-24 Kuraray Noritake Dental Inc. Zirconia pre-sintered body suitable for dental use
CN112624761B (zh) * 2019-10-08 2024-04-30 东曹株式会社 氧化锆烧结体及其制造方法

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62260766A (ja) * 1986-05-08 1987-11-13 東レ株式会社 アルミナ焼結体
JP2000219570A (ja) * 1999-01-29 2000-08-08 Sumitomo Chem Co Ltd 透光性アルミナ焼結体の製造方法およびその用途
JP2002338336A (ja) * 2001-05-16 2002-11-27 Kobe Steel Ltd 摺動部用アルミナセラミックス製品およびその製造方法
JP2015533754A (ja) * 2012-08-20 2015-11-26 セラムテック ゲゼルシャフト ミット ベシュレンクテル ハフツングＣｅｒａｍＴｅｃ ＧｍｂＨ 酸化ジルコニウムベースの複合材
JP2016026986A (ja) * 2014-06-23 2016-02-18 東ソー株式会社 着色透光性ジルコニア焼結体と粉末、及びその用途
CN106619140A (zh) * 2016-11-16 2017-05-10 西安交通大学 一种氧化铝全瓷牙科修复材料及其制备方法
WO2019022194A1 (ja) * 2017-07-28 2019-01-31 住友化学株式会社 組成物、フィルム、積層構造体、発光装置、及びディスプレイ
US20220055948A1 (en) * 2020-08-21 2022-02-24 Ivoclar Vivadent Ag Aluminium Oxide Ceramic Material

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
ANONYMOUS: "Taimicron", 1 December 2021 (2021-12-01), XP093073824, Retrieved from the Internet <URL:https://www.taimei-chem.co.jp/pdf/PNF_Taimicron.pdf> *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2025105493A1 (ja) * 2023-11-16 2025-05-22 クラレノリタケデンタル株式会社 高透明かつ高強度の歯科用アルミナ仮焼体及びその焼結体並びにそれらの製造方法

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