Dental ceramic staining solution

Abstract

The present invention provides a dental ceramic coloring solution that imparts a desired color tone to dental ceramic and that can improve the strength of the dental ceramic. The present invention pertains to a coloring solution that contains a coloring component, a solvent, and a Zr component, and that is for coloring dental ceramic.

Description

[Technical Field]

[0001] The present invention relates to a coloring solution for dental ceramics. More specifically, it relates to a coloring solution for dental ceramics that is suitably used in the fabrication of dental prostheses such as inlays, onlays, veneers, crowns, bridges, abutment teeth, dental posts, dentures, denture bases, and implant components (fixtures and abutments) that are machined using a dental CAD / CAM system. [Background technology]

[0002] Traditionally, metals have been commonly used in dental products (for example, dental prostheses such as typical crowns, tooth crowns, and bridges, as well as orthodontic products and dental implants). However, metals have the disadvantage of being distinctly different in color from natural teeth and lacking aesthetic appeal, and they can also cause allergies due to metal leaching. Therefore, to solve the problems associated with the use of metals, ceramic materials such as aluminum oxide (alumina) or zirconium oxide (zirconia) have been used in dental products as alternative materials to metals. Zirconia, in particular, is in high demand because of its superior strength and relatively good aesthetics, especially in recent years when its price has decreased.

[0003] In recent years, CAD / CAM systems have become widespread, which use computers to design the final shape of dental prostheses or large implant prostheses, and then mill them using milling equipment. Ceramics are commonly used as the mill blank material for these CAD / CAM systems, due to the emphasis on aesthetics. Recently, ceramics that reproduce natural tooth color by arranging different shades vertically in the thickness direction are becoming increasingly popular. However, for shades that are difficult to reproduce, high aesthetic requirements have traditionally been met by coating the surface of the ceramic, which has been processed into the shape of the dental prosthesis, with dental porcelain to achieve color.

[0004] However, the technique of coating and coloring teeth with dental porcelain requires specialized knowledge and exceptional skill. Specifically, coloring with dental porcelain requires the precise reproduction of the shape and structure of natural teeth through the layering of dental porcelain, as well as the development of a highly aesthetic color, thus demanding a high level of expertise.

[0005] Therefore, as a method for coloring dental prostheses, in order to avoid the problems that arise from the use of dental porcelain, a technique is commonly used that applies a dental ceramic coloring solution to dental ceramics to achieve higher aesthetics, instead of coloring dental porcelain, which requires a high level of skill.

[0006] In particular, with the increasing demand for ceramic materials and the rising aesthetic demands of individuals, the frequency of use of dental ceramic coloring solutions is expected to increase.

[0007] On the other hand, even zirconia, which is known for its superior strength among ceramics, does not match the strength of conventionally used metals. In particular, zirconia containing stabilizers to improve translucency tends to decrease in strength as the amount of stabilizer increases, so there is a need to improve the strength of zirconia.

[0008] As a means of improving the strength of zirconia, for example, Patent Document 1 discloses one or more colorants containing a rare earth element metal or ion present in the solution in an amount of at least about 0.05 mol / L (solvent) and a transition metal or ion present in the solution in an amount of about 0.00001 to about 0.05 mol / L (solvent). However, for example, when coloring zirconia using a colorant containing erbium, the erbium also functions as a stabilizer for zirconia, leading to a decrease in physical properties such as strength. Depending on the type of metal ion, there are problems that can cause a decrease in the physical properties of zirconia. Furthermore, it has not been possible to improve the strength of zirconia sintered bodies using coloring solutions. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Special Publication No. 2010-534245 [Overview of the project] [Problems that the invention aims to solve]

[0010] The present invention aims to provide a dental ceramic coloring solution that can impart a desired color to dental ceramics while also improving the strength of dental ceramics. [Means for solving the problem]

[0011] The inventors of this invention conducted extensive research to solve the above problems and found that a dental ceramic coloring solution containing a Zr component in addition to a coloring component could solve the above problems. Further investigation led to the completion of the present invention.

[0012] In other words, the present invention encompasses the following inventions. [1] A coloring solution for coloring dental ceramics, comprising a coloring component, a solvent, and a Zr component. [2] The colored solution according to [1], wherein the coloring component is an ion or a complex. [3] The coloring solution according to [1] or [2], wherein the coloring component comprises at least one component selected from the group consisting of Al, K, Cr, Fe, Na, V, Y, Gd, La, Yb, Tm, Ni, Mn, Co, Nd, Pr, Cu, Tb, and Er components. [4] The colored solution according to any one of [1] to [3], wherein the Zr component is an ion or a complex. [5] The colored solution according to any one of [1] to [4], wherein the Zr component comprises at least one selected from the group consisting of zirconium chloride hydrate, zirconium acetate, zirconium oxide hydrate, and zirconium nitrate hydrate. [6] The colored solution according to any one of [1] to [5], wherein the content of the Zr component is 0.0650 to 0.900 mol / L as Zr ions. [7] The colored solution according to any one of [1] to [6], wherein the solvent comprises water and / or an organic solvent. [8] The solubility parameter of the organic solvent is 17.7 (MPa) 1 / 2 The above is the colored solution described in [7]. [9] The colored solution according to [7] or [8], wherein the organic solvent comprises at least one selected from the group consisting of alcohols, glycols, triols, and ketones.

[10] The coloring solution according to any one of [1] to [9], wherein the coloring component further contains component V.

[11] The coloring solution according to any one of [1] to

[10] , wherein the coloring component further contains a Ni component.

[12] The coloring solution according to any one of [1] to

[11] , wherein the coloring component further contains an Al component.

[13] The coloring solution according to any one of [1] to

[12] , further comprising the coloring component Co component.

[14] The coloring solution according to any one of [1] to

[13] , wherein the coloring component further contains an Er component.

[15] The coloring solution according to any one of [1] to

[14] , further comprising the coloring component.

[16] The coloring solution according to any one of [1] to

[15] , wherein the coloring component further contains a Mn component.

[17] The coloring solution according to any one of [1] to

[16] , wherein the dental ceramic contains zirconia as the main component.

[18] Dental ceramics having a coloring component and a Zr component supported on the surface.

[19] The dental ceramic according to

[18] , wherein the coloring component is an ion or a complex.

[20] The dental ceramic according to

[18] or

[19] , wherein the coloring component comprises at least one component selected from the group consisting of Al, K, Cr, Fe, Na, V, Y, Gd, La, Yb, Tm, Ni, Mn, Co, Nd, Pr, Cu, Tb, and Er components.

[21] The dental ceramic according to any one of

[18] to

[20] , wherein the Zr component is an ion or a complex. [Effects of the Invention]

[0013] The dental ceramic coloring solution of the present invention can impart a desired color to dental ceramics while also improving their strength. Furthermore, in dental ceramics that typically contain zirconia as the main component and yttria as a stabilizer, the transparency changes depending on the mixing ratio. Generally, transparency decreases as the proportion of zirconia increases and the proportion of yttria decreases. Therefore, it is expected that transparency will decrease when a coloring component containing zirconium is applied to dental zirconia. However, the coloring solution of the present invention can improve the strength of dental ceramics while suppressing changes in transparency. [Modes for carrying out the invention]

[0014] The present invention relates to a coloring solution for coloring dental ceramics, comprising a coloring component, a solvent, and a Zr component.

[0015] <Coloring ingredients> First, the coloring components contained in the coloring solution of the present invention will be described.

[0016] In this invention, the coloring component is used to color a ceramic sintered body when a coloring solution is applied to a calcined or uncalcined ceramic body before sintering. The coloring component is not particularly limited, but examples include ions and complexes, with metal ions being particularly preferred.

[0017] The coloring ions and complexes used in the present invention will be described below. The ions and complexes contain one or more colorable cations. "Colorable" means that they have significant absorption in the visible spectrum (for example, in the wavelength range of 380 to 790 nm) to the human eye. The colorable cations in the present invention develop color after firing. The ions and complexes of the present invention can dissolve the colorable cations, thereby allowing them to be coated onto a calcined or uncalcined ceramic body and color the ceramic sintered body after firing.

[0018] As the cation with coloring property, ions of at least one component selected from the group consisting of Al, K, Cr, Fe, Na, V, Y, Gd, La, Yb, Tm, Ni, Mn, Co, Nd, Pr, Cu, Tb, and Er are preferable, ions of at least one component selected from the group consisting of Al, K, Cr, Fe, Na, V, Ni, Mn, Co, and Er are more preferable, and ions of at least two components selected from the group consisting of Al, K, Cr, Fe, Na, V, Ni, Mn, Co, and Er are even more preferable. The ion solution may contain only one of the cations or may contain a combination of two or more cations.

[0019] The cation with coloring property may be added to the solvent described below as a salt containing the cation and an anion. Examples of the anion include OAc - , NO3 - , NO2 - , CO3 2- , HCO3 - , ONC - , SCN - , SO4 2- , SO3 2- , glutarate, lactate, gluconate, propionate, butyrate, glucuronate, benzoate, phenolate, halogen anions (fluoride, chloride, bromide), acetate, etc. Ac means an acetyl group.

[0020] One preferred embodiment is a coloring solution in which the coloring component contains a nickel (Ni) component. The nickel component can reproduce reddish-brown tones, and by combining it with yellow to suppress brown, a desired dental standard color can be obtained. For example, using a coloring solution containing a nickel component may result in a lower L* value in the (L*, a*, b*) ratio of the L*a*b* color system. Also, using a coloring solution containing a nickel component may result in a higher a* value. Furthermore, using a coloring solution containing a nickel component may result in a lower b* value. Examples of nickel compounds include divalent, trivalent, and tetravalent compounds, with divalent nickel compounds being preferred. Examples of nickel components include nickel(II) hydroxide, nickel(II) chloride hydrate (hexahydrate), nickel(II) nitrate hydrate (hexahydrate), nickel(II) sulfate hydrate (hexahydrate), and nickel(II) acetate hydrate (tetrahydrate). One type of nickel component may be used alone, or two or more types may be used in combination.

[0021] Another preferred embodiment is a coloring solution containing a Cr component. The Cr component can reproduce a grayish-green tone, and by combining it with yellow to suppress the green, a desired dental standard color tone can be obtained. Examples of chromium compounds include trivalent and tetravalent compounds, with trivalent chromium compounds being preferred. For example, using a coloring solution containing a Cr component may result in a lower L* value in the (L*, a*, b*) color system. Also, using a coloring solution containing a Cr component may result in a higher a* value. Furthermore, using a coloring solution containing a Cr component may result in a lower b* value. Examples of chromium (Cr) components include chromium(III) chloride, chromium(III) chloride hydrate (hexahydrate), chromium(III) nitrate hydrate (notahydrate), chromium(III) sulfate hydrate (n-hydrate), and chromium(III) acetate hydrate (monohydrate). Chromium(III) nitrate hydrate (notahydrate), chromium(III) chloride hydrate (hexahydrate), and chromium(III) acetate hydrate (monohydrate) are preferred due to their excellent solubility in water and organic solvents. The Cr component may be used alone or in combination of two or more.

[0022] One preferred embodiment of the present invention is a coloring solution in which the coloring component further contains an Al component. The Al component contains Al ions or complexes and can increase the redness. It may also improve the strength of zirconia. Regarding the improvement in zirconia strength, it is hypothesized that the dispersion of the Al component between zirconia crystals increases the specific surface area of ​​the intercrystalline bonds, improving the intercrystalline bonding force, and the high toughness properties of the Al component manifest in that bonding force.

[0023] Al ions or complexes may be added to the colored solution as salts containing Al cations and anions, or as complexes containing Al and its ligands, for example, OAc - NO3 - NO2 - CO3 2- , HCO3 - ONC - SCN - SO4 2- , SO3 2- Examples include glutarates, lactates, glucons, propionates, butyrates, glucuronates, benzoates, phenolates, halogen anions (fluorides, chlorides, bromides), and acetates.

[0024] Specific examples of compounds containing the Al component include aluminum ethoxide, aluminum butoxide, aluminum propoxide, barium aluminate, magnesium aluminate, lithium aluminate, aluminum benzoate, aluminum chloride hydrate (aluminum chloride hexahydrate), aluminum oleate, aluminum perchlorate hydrate (aluminum perchlorate trihydrate, aluminum perchlorate hexahydrate, etc.), aluminum citrate hydrate (aluminum citrate monohydrate), aluminum gluconate, lithium tetrachloroaluminate, and lithium aluminum tetrachloride. Examples include aluminum oxide, aluminum selenite hydrate, aluminum oxalate hydrate, aluminum tartrate hydrate, aluminum metazirconate, aluminum octanoate hydroxide, aluminum stearate, aluminum titanate, aluminum lactate, aluminum palmitate, lithium tetrahydridoaluminate, lithium aluminum tetrahydrogen, aluminum iodide, aluminum laurate, aluminum butyrate, aluminum nitrate hydrate (aluminum nitrate xahydrate, etc.), aluminum sulfide, and aluminum cesium sulfate hydrate. Of these, aluminum chloride hydrate, aluminum perchlorate hydrate, aluminum oxalate hydrate, and aluminum nitrate hydrate are preferred from the viewpoint of solubility. These Al components can be used individually or in appropriate combinations of two or more.

[0025] Furthermore, the coloring solution of the present invention may contain a vanadium (V) component to color dental ceramics to a yellowish hue. One preferred embodiment of the present invention is a coloring solution in which the coloring component further contains a vanadium (V) component.

[0026] The ion or complex of V may be added to the colored solution as a salt containing the cation and anion of V, or as a complex containing V and a ligand. Examples of such anion or ligand include OAc - NO3 - NO2 - CO3 2- , HCO3 - ONC - SCN - SO42- , SO3 2- Examples include glutarates, lactates, glucons, propionates, butyrates, glucuronates, benzoates, phenolates, halogen anions (fluorides, chlorides, bromides), and acetates.

[0027] As for vanadium compounds, vanadium compounds with a +IV and / or +V valency are preferred from the viewpoint of stability and ease of handling, and oxide vanadium compounds are more preferred.

[0028] Specific examples of compounds of component V include vanadium acetylacetonate, vanadyl acetylacetonate, vanadyl stearate, vanadium naphthenate, vanadium benzoylacetonate, vanadyl oxalate, bis(maltrate)oxovanadium(IV), oxobis(1-phenyl-1,3-butanedione)vanadium, vanadium(V) oxytriisopropoxide, vanadium(V) trichloride oxide, vanadium(IV) dichloride oxide, vanadium(III) chloride hydrate (hexahydrate), vanadium(III) chloride anhydride, vanadium disilicate, divanadium(III) trioxide, divanadium(IV) tetroxide, divanadium(V) pentoxide, tetravanadium diferric oxide, vanadyl(IV) sulfate hydrate, vanadium(III) bromide, and vanadyl oxalate (oxovanadium oxalate). Vanadiyl(IV), vanadyl(IV) acetate (VO[OC(O)CH3]2), vanadyl(V) nitrate (VO(NO3)3), vanadyl glycolate, vanadium hydride, vanadium selenide, vanadium carbide (VC), vanadium nitride (VN), potassium divanadate, potassium vanadate, potassium metavanadate (KVO3)(V), sodium metavanadate (NaVO3)(V), divanadyl Examples include sodium vanadate (Na4V2O7), sodium vanadate (Na3VO4), sodium vanadate hydrate, lithium metavanadate (LiVO3), rubidium divanadate (Rb4V2O7), rubidium metavanadate (RbVO3), rubidium vanadate (Rb3VO4), vanadium diboride, vanadium boride (VB), vanadium(III) sulfide (V2S3), etc. Of these, vanadyl oxalate, vanadyl nitrate, and vanadyl acetate are preferred because the colored solution has excellent stability and ease of handling. The vanadium component may be used alone or in combination of two or more.

[0029] Furthermore, the coloring solution of the present invention may also contain a Co component. One preferred embodiment of the present invention is a coloring solution in which the coloring component further contains a Co component.

[0030] Co ions or complexes may be added to the colored solution as salts containing Co cations and anions, or as complexes containing Co and its ligands. Examples of such anions or ligands include OAc - NO3 - NO2 - CO3 2- , HCO3 - ONC - SCN - SO4 2- , SO3 2- Examples include glutarates, lactates, glucons, propionates, butyrates, glucuronates, benzoates, phenolates, halogen anions (fluorides, chlorides, bromides), and acetates.

[0031] Specific examples of compounds containing the Co component include bis(acetylacetonato)diquacobalt(II), tris(acetylacetonato)cobalt(III), cobalt(II) hydrate, cobalt(II) benzoate, cis-tetraamminedichlorocobalt(III) chloride, pentaamminechlorocobalt(III) chloride, hexaamminecobalt(III) chloride, hexaamminecobalt(III) nitrate, ammonium diamminetetranitrocobalt(III)ate, triamminetrinitrocobalt(III), and tetraamminedinitrocobalt(III). Balt(III) chloride, potassium diamminetetranitrocobalt(III)ate, cobalt(II) chloride hydrate (e.g., cobalt(II) chloride hexahydrate), cobalt(II) chloride, cobalt(III) chloride, cobalt(II) octanoate, cobalt(II) oleate, cobalt(II) perchlorate hydrate (cobalt(II) perchlorate hexahydrate), cobalt(II) fluoride hydrate (cobalt(II) fluoride dihydrate, cobalt(II) fluoride trihydrate, cobalt(II) fluoride tetrahydrate), octacarbonylcobalt (CO2(CO)8), cobalt formate Cobalt(II) hydrate, cobalt(II) citrate hydrate, cobalt disilide, cobalt(II) acetate, cobalt(II) acetate hydrate (cobalt(II) acetate tetrahydrate), cobalt(II) oxide, cobalt(III) oxide, tricobalt tetroxide (Co3(CO)4), potassium hexacyanocobalt(III)ate, cobalt(II) bromide, cobalt(II) bromide hydrate, cobalt(II) oxalate hydrate (e.g., cobalt(II) oxalate dihydrate, cobalt(II) oxalate tetrahydrate, etc.), cobalt resinate, cobalt(II) nitrate hydrate (cobalt(II) nitrate I) Cobalt(II) trihydrate, cobalt(II) nitrate hexahydrate, cobalt(II) metazirconate, cobalt(II) hydroxide, cobalt(III) hydroxide, cobalt(II) stearate, cobalt(II) selenate, cobalt(II) selenate hexahydrate, cobalt(II) tungstate tetrahydrate, cobalt(II) carbonate hydroxide, ammonium tetrakis(thiocyanato)cobalt(II) hydrate, cobalt(II) thiocyanate, cobalt(II) metatitanate, potassium hexanitrocobalt(III), sodium hexanitrocobalt(III),Examples include hexaamminecobalt(III) sulfate, pentacobalt diboride, cobalt(II) molybdate hydrate, cobalt(II) iodide hydrate, cobalt(II) laurate, cobalt(II) sulfide, cobalt(II) sulfate hydrate, cobalt(II) phosphide, and cobalt(II) phosphate hydrate. Of these, cobalt(II) chloride hydrate, cobalt(II) perchlorate hydrate, cobalt(II) fluoride hydrate, cobalt(II) nitrate hydrate, cobalt(II) oxalate hydrate, and cobalt(II) acetate hydrate are preferred from the viewpoint of solubility and color development. The Co component can be used individually or in appropriate combinations of two or more.

[0032] Furthermore, the coloring solution of the present invention may also contain an Er component. One preferred embodiment of the present invention is a coloring solution in which the coloring component further contains an Er component.

[0033] Er ions or complexes may be added to the colored solution as salts containing Er cations and anions, or as complexes containing Er and its ligands. Examples of such anions or ligands include OAc. - NO3 - NO2 - CO3 2- , HCO3 - ONC - SCN - SO4 2- , SO3 2- Examples include glutarates, lactates, glucons, propionates, butyrates, glucuronates, benzoates, phenolates, halogen anions (fluorides, chlorides, bromides), and acetates.

[0034] Specific examples of Er components include trivalent erbium compounds such as tris(acetylacetonate)erbium hydrate, erbium chloride hydrate (erbium chloride hexahydrate), erbium perchlorate hydrate, erbium acetate hydrate (erbium acetate tetrahydrate), erbium oxide, erbium oxalate hydrate, erbium nitrate hydrate, erbium stearate, erbium fluoride, erbium tetraboride, erbium iodide hydrate, erbium sulfide, and erbium sulfate hydrate. Of these, erbium chloride hydrate, erbium perchlorate hydrate, erbium nitrate hydrate, erbium oxalate hydrate, and erbium acetate hydrate are preferred from the viewpoint of solubility and color development. The Er component can be used alone or in appropriate combinations of two or more types.

[0035] Furthermore, the coloring solution of the present invention may also contain a Mn component. One preferred embodiment of the present invention is a coloring solution in which the coloring component further contains a Mn component.

[0036] Mn ions or complexes may be added to the colored solution as a salt containing Mn cations and anions, or as a complex containing Mn and its ligands. Examples of such anions or ligands include OAc - NO3 - NO2 - CO3 2- , HCO3 - ONC - SCN - SO4 2- , SO3 2- Examples include glutarates, lactates, glucons, propionates, butyrates, glucuronates, benzoates, phenolates, halogen anions (fluorides, chlorides, bromides), and acetates.

[0037] Specific compounds of the Mn component include manganese(II) chloride hydrate (tetrahydrate), manganese(II) nitrate hydrate (hexahydrate), manganese(II) acetate hydrate (tetrahydrate), manganese(II) sulfate hydrate (e.g., pentahydrate), etc. The Mn component can be used alone or in appropriate combination of two or more kinds.

[0038] <Zr component> Next, the Zr component contained in the coloring solution of the present invention will be described. The Zr component contains Zr ions or complexes, and when coexisting with the coloring component, the strength of the ceramics is improved.

[0039] The reason why the strength of the ceramics is improved by applying the dental ceramics coloring solution containing the Zr component is not clear, but the present inventors presume as follows. That is, when the dental ceramics coloring solution of the present invention is applied to, for example, a dental zirconia green body, the Zr component penetrated into the green body reacts with the stabilizer of zirconia as tetragonal crystal during subsequent firing and is considered to be related to the improvement of strength by remaining as partially stabilized zirconia in the zirconia sintered body. Furthermore, it is also presumed that the excessive grain growth of crystals by the stabilizer and the transformation into cubic crystal are suppressed by the penetrated Zr component, and a uniform zirconia crystal structure is constructed, which is also a factor for the improvement of strength.

[0040] The Zr ions or complexes may be added to the coloring solution as salts containing Zr cations and anions, or complexes containing Zr and its ligands. Examples of the anion or ligand include, for example, OAc - , NO3 - , NO2 - , CO3 2- , HCO3 - , ONC - , SCN - , SO4 2- , SO3 2- , glutarate, lactate, gluconate, propionate, butyrate, glucuronate, benzoate, phenolate, halogen anions (fluoride, chloride, bromide), acetate, etc.

[0041] Specific examples of compounds added to contain the above ions or complexes in the colored solution of the present invention include: zirconium chloride oxide hydrate (IV), zirconium sulfide (IV), tetrakis(acetylacetonate)zirconium (IV), zirconium chloride (IV), zirconium octanoate (IV), zirconium oleate oxide (IV), dichlorobis(η5-cyclopentadienyl)zirconium (IV), zirconium acetate oxide (IV), zirconium oxide (IV) hydrate, zirconium stearate oxide (IV), zirconium nitrate oxide (IV) hydrate, zirconium (IV) n-butoxide, zirconium hydride (II), zirconium carbide (IV), disizirconium trioxide carbonate hydrate, zirconium nitride, ammonium hexafluorozirconate (IV), zirconium iodide (IV), zirconium laurate oxide (Zr(C) 11 H 23 Examples include COO)2O), zirconium(IV) sulfate hydrate, and zirconium(IV) dihydrogen phosphate. Of these, zirconium(IV) chloride hydrate, zirconium(IV) chloride, zirconium(IV) acetate oxide, zirconium(IV) oxide hydrate, and zirconium(IV) nitrate hydrate are preferred, with zirconium(IV) chloride hydrate being more preferred, as they can further improve the strength of dental ceramics. The Zr component can be used alone or in appropriate combinations of two or more types.

[0042] The Zr content in the coloring solution is preferably 0.0650 to 0.900 mol / L, more preferably 0.0800 to 0.850 mol / L, and even more preferably 0.0900 to 0.800 mol / L, in terms of Zr ions in the entire solution, from the viewpoint of improving the strength of dental ceramics. When the content is 0.0650 mol / L or higher, the effect of improving the strength of dental ceramics can be obtained, and when it is 0.900 mol / L or lower, the strength can be improved without reducing the aesthetics of the dental ceramics. The Zr content can be measured, for example, by inductively coupled plasma (ICP) emission spectroscopy, X-ray fluorescence analysis, etc.

[0043] The coloring solution of the present invention preferably contains water and / or an organic solvent. The water and / or organic solvent dissolve the Zr component and the coloring component, improving the penetration of the coloring solution into dental ceramics. The solvent content in the coloring solution is preferably 45 to 99% by mass, more preferably 60 to 98.5% by mass, and even more preferably 75 to 98% by mass.

[0044] The water used must be substantially free of impurities that adversely affect the effects of the present invention, and purified water, distilled water, ion-exchanged water, and pure water are preferred. The water content in the colored solution is preferably 45 to 99% by mass, more preferably 60 to 98.5% by mass, and even more preferably 75 to 98% by mass.

[0045] The organic solvent has a solubility parameter (SP value) of 17.7 MPa. 1 / 2 The above is preferable, and 18.0 (MPa) 1 / 2 The above is more preferable. The SP value is 17.7 (MPa). 1 / 2 In the above case, the solubility of the coloring component is sufficient, sufficient penetration of the coloring solution into the dental ceramics is obtained, sufficient coloring is achieved, and the strength of the dental ceramics can be further improved.

[0046] The SP value is expressed as the square root of the cohesive energy density (CED), which is the force of attraction between molecules. CED is the amount of energy required to evaporate 1 mL of a substance.

[0047] The aforementioned SP value can be calculated using the following formula (A) by the Fedors method. SP value = (CED value) 1 / 2 =(E / V) 1 / 2 ...Formula (A) In equation (A) above, E is the molecular cohesive energy (J / mol) and V is the molecular volume (cm³). 3 The value is ( / mol). There are various methods for calculating the SP value, but in this invention, we used Fedors' method, which is commonly used.

[0048] For the calculation method, molecular cohesive energy E, and molecular volume V data mentioned above, the methods and data described in "Studies on Solubility Parameters of Additives," by Shinichi Ueda, Tomoo Yamada, and Masami Sugishima, published in October 2010, "Research on Paints," No. 152, can be used.

[0049] The organic solvent is preferably an alcohol, glycol, triol, ketone, or a mixture selected from combinations thereof. Specific examples include methanol, ethanol, 1-propanol, 2-propanol, isopropanol, 1-butanol, 2-butanol, 1-heptanol, 2-heptanol, 3-heptanol, 1-hexanol, 2-hexanol, 3-hexanol, 2-methyl-1-pentanol, 3-methyl-1-pentanol, 4-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 2,2-dimethyl-1-butanol, 2-ethyl-1-butanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobenzyl ether, and propylene glycol. Alcohols such as monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobenzyl ether, propylene glycol monopropyl ether, tripropylene glycol monomethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, benzyl alcohol, 2-(benzyloxy)ethanol, 3-(benzyloxy)-1-propanol, 2-(benzyloxy)-1-butanol, 5-(benzyloxy)-1-pentanol, etc.1,2-Ethanediol, 1,2-Propanediol, 1,3-Propanediol, 1,2-Butanediol, 1,3-Butanediol, 1,4-Butanediol, 2,3-Butanediol, 1,2-Pentanediol, 1,5-Pentanediol, 2,4-Pentanediol, 1,2-Hexanediol, 2,5-Hexanediol, Ethylene glycol, Diethylene glycol, Triethylene glycol, Tetraethylene glycol, Polyethylene glycol (Molecular weight 200-600), Propylene glycol, Dipropylene glycol, Polypropylene glycol, 1- Examples include diols such as methyl-1,3-propanediol, 2-methyl-1,3-propanediol, 2-methyl-1,4-butanediol, 3-methyl-1,3-butanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, and 2-ethyl-1,3-hexanediol; triols such as glycerin, 1,2,4-butanetriol, 1,2,3-butanetriol, and 1,2,6-hexanetriol; and ketones such as acetone, 2-butanone, 2-pentanone, and cyclohexanone. These organic solvents can be used individually or in combination of two or more as appropriate. Furthermore, the viscosity may be adjusted using the organic solvent as a thickening agent, as described later.

[0050] The organic solvent content in the colored solution of the present invention is preferably 45 to 99% by mass, more preferably 60 to 98.5% by mass, and even more preferably 75 to 98% by mass.

[0051] The colored solution of the present invention may contain a complexing agent, to the extent that it does not impair the effects of the present invention. Adding a complexing agent may be beneficial for improving the storage stability of the colored solution, accelerating the dissolution process of salts added to the colored solution, and / or increasing the amount of salt that can dissolve in the colored solution.

[0052] Complexing agents can typically form complexes with metal ions present in colored solutions. The formed complexes must be soluble in the solvent. For example, the complexing agent can be used in at least a stoichiometric ratio with respect to the molar amount of ions contained in the colored solution, and good results can be obtained if the molar ratio of the complexing agent to the cations in the colored solution is about 1, about 2, or about 3 or more.

[0053] Examples of the complexing agent include N,N-di(2-hydroxyethyl)glycine, acetylacetonate, crown ether, cryptand, ethylenediamine triacetate and its salts, ethylenediamine tetraacetate and its salts, nitrilotriacetate and its salts, citric acid and its salts, triethylenetetraamine, porfin, polyacrylate, polyasparagate, acid peptide, phthalocyanine, salicylate, glycinate, lactate, propylenediamine, ascorbate, oxalic acid and its salts, and mixtures thereof. The complexing agent can be used individually or in appropriate combinations of two or more.

[0054] The content of the complexing agent in the colored solution of the present invention is not particularly limited as long as the effects of the present invention are achieved. For example, it is preferable to contain a sufficient amount to dissolve the cations in the solution or to prevent the precipitation of these cations. Specifically, in the colored solution, 0.01% by mass or more is preferred, 0.05% by mass or more is more preferred, and 0.10% by mass or more is even more preferred. Furthermore, there is no specific upper limit to the content, but 50% by mass or less is preferred, 20% by mass or less is more preferred, and 10% by mass or less is even more preferred. If the amount of complexing agent used is too small, it may not dissolve completely, and if the amount of complexing agent used is too large, the excess complexing agent itself may remain undissolved.

[0055] The pH of the colored solution of the present invention is preferably 0 to 9, more preferably 1 to 7, and even more preferably 2 to 6. If the pH is outside the above range, cations may begin to precipitate from the solution. For example, if the colored solution is an aqueous solution, a pH of 0 to 9 is preferred. Also, if the colored solution does not contain a complexing agent, a pH of 0 to 6 is preferred, and if it contains a complexing agent, a pH of 3 to 9 is preferred. The pH can be measured using a commercially available pH meter (for example, the LAQUA twin compact pH meter manufactured by Horiba, Ltd.).

[0056] The coloring solution of the present invention preferably has an appropriate viscosity so that the required amount of solution can not only be applied to the ceramic surface but also move into the pores of the unfired or calcined ceramic body. The appropriate viscosity is preferably, for example, 0.1 to 10,000 mPa at 20°C, more preferably 0.5 to 6,000 mPa, and even more preferably 1 to 3,000 mPa. If the viscosity is too high, it may not be possible to contain it in the pores of the unfired or calcined ceramic body. The method for measuring viscosity is not particularly limited, but it can be measured by a Brookfield viscometer at 25°C.

[0057] The colored solution of the present invention may contain one or more thickening agents, to the extent that they do not impede the effects of the present invention, in order to achieve an appropriate viscosity.

[0058] The viscosity may be adjusted by selecting the thickening agent from the organic solvents mentioned above, or it may be selected from the thickening agents listed below. Examples of thickening agents other than the organic solvents mentioned above include polysaccharide compounds such as methylcellulose, carboxycellulose, hydroxyethylcellulose, xanthan gum, guar gum, carrageenan, tamarind seed gum, and pectin; sugar alcohol compounds such as sorbitol, erythritol, xylitol, and trehalose; synthetic polyol compounds such as diglycerin, triglycerin, polyglycerin, and polyvinyl alcohol; and solid organic compounds such as sodium polyacrylate, ammonium polyacrylate, polyethylene oxide, polyethylene glycol (molecular weight 1000 or more), polyvinylpyrrolidone, calcium stearate, magnesium stearate, zinc stearate, aluminum stearate, polyethylene glycol monostearate, 12-hydroxystearic acid, stearamide, oleamide, and ethylenebisoleamide. These thickening agents can be used individually or in appropriate combinations of two or more.

[0059] The content of the thickener in the colored solution of the present invention is preferably 0.01 to 10% by mass, more preferably 0.1 to 8% by mass, and even more preferably 0.2 to 5% by mass.

[0060] The coloring solution of the present invention may contain other additives, as long as they do not impair the effects of the present invention.

[0061] Examples of such additives include stabilizers (e.g., methoxyphenol, hydroquinone, topanol A (2,4-dimethyl-6-tert-butylphenol (excluding stabilizers capable of suppressing the phase transition of zirconia)), and mixtures thereof), buffers (e.g., acetates, amino buffers, and mixtures thereof), preservatives (e.g., sorbic acid, benzoic acid, and mixtures thereof), and mixtures thereof. Additives may be used individually or in combination of two or more.

[0062] The content of the additive in the coloring solution of the present invention can be, for example, 0.01 to 10% by mass, 0.05 to 5% by mass, or 0.1 to 3% by mass.

[0063] The coloring solution of the present invention may contain a coloring agent that decolorizes after the firing of zirconia. The coloring agent that decolorizes after the firing of zirconia is not limited as long as it is decolorized after the firing of zirconia and can satisfy the color difference before and after firing, and examples include organic dyes.

[0064] The organic dye is not particularly limited as long as it has a chromophore and is soluble in a coloring solution, but aromatic organic dyes, i.e., organic dyes containing one or more aromatic groups that may be substituted, are preferred, and aromatic organic dyes having a co-chromophore in addition to a chromophore are more preferred. The chromophore is not particularly limited as long as it is an atomic group that is bonded to an aromatic ring and causes color development, and examples include nitro groups, azo groups, ketimide groups (>C=N-), carbonyl groups, carbon-carbon double bonds, carbon-carbon triple bonds, carbon-nitrogen multiple bonds, thiocarbonyl groups, nitroso groups, azoxy groups, etc. The organic dye may contain one of these atomic groups alone or two or more in appropriate combinations. The co-chromophore may include a hydroxyl group, amino group, carboxyl group, sulfone group, halogen atom, etc. The organic dye may contain one of these co-chromophore alone or two or more in appropriate combinations.

[0065] Furthermore, since harmful or toxic substances cannot be used as colorants to decolorize zirconia after firing, food colorants are preferred as organic pigments, and food colorants that dissolve in the coloring solution are even more preferred. Examples of such food colorants include organic pigments containing two or more aromatic groups, such as Yellow 4 (tartrazine), Yellow 5 (Sunset Yellow FCF), Red 2 (amaranth), Red 102 (new coccine), Blue 1 (Brilliant Blue FCF), Blue 2 (indigo carmine), Green 3 (fast green FCF), Red 102 (new coccine); Acid Red 289, Bromopyrogallol Red, Rhodamine B, Rhodamine 6G, Rhodamine 6GP, Rhodamine 3GO, Rhodamine 123, Eosin (eosin B, eosin Y), fluorescein, fluorescein isothiocyanate, etc. Examples include organic dyes containing condensed aromatic groups with xanthene as the parent core (xanthene-based dyes); cochineal dye (carminic acid dye); betalain-based dyes such as beet red (main components: isobetanin and betanin), betanin, isobetanin, probetanin, neobetanin, etc., and organic dyes containing two or more aromatic groups such as Yellow 4 (tartrazine), Yellow 5 (Sunset Yellow FCF), Red 2 (amaranth), Red 102 (new coccine), Blue 1 (Brilliant Blue FCF), Green 3 (Fast Green FCF), and isobetanin, and having a ketimide group or azo group as a chromophore. Furthermore, the coloring agent (A) can be changed depending on the content of the stabilizer in the calcined zirconia to which the coloring solution of the present invention is applied. In one preferred embodiment, the coloring solution for zirconia is an organic dye containing two or more aromatic groups, having a ketimide group or an azo group as a chromophore, and a sulfone group as a auxophore. In this specification, "aromatic group" includes aromatic groups whose ring structure consists only of carbon atoms, and heteroaromatic groups whose ring structure includes elements other than carbon (oxygen, nitrogen, etc.). The coloring agent used to decolorize the zirconia after calcination can be used alone or in appropriate combinations of two or more types.Furthermore, the coloring agent used to decolorize zirconia after firing exhibits different color intensity depending on the pH of the coloring solution, and the compound structure may differ depending on the pH. However, as long as the effects of the present invention are achieved, the pH of the coloring solution for zirconia is not particularly limited, and a pH that exhibits an appropriate color intensity can be adopted and used depending on the type of coloring agent used to decolorize zirconia after firing.

[0066] The content of the coloring agent that decolorizes the zirconia after firing is not particularly limited as long as the liquid component develops color, but is preferably 0.009 to 3.0% by mass, more preferably 0.09 to 1.6% by mass, even more preferably 0.2 to 1.4% by mass, and particularly preferably 0.25 to 1.2% by mass, relative to the total mass of the coloring solution.

[0067] One embodiment is a coloring solution in which the coloring component substantially does not contain a coloring agent that decolorizes after the firing of the zirconia. Substantially containing a coloring agent that decolorizes after the firing of the zirconia means that the content of the coloring agent that decolorizes after the firing of the zirconia is preferably less than 0.009% by mass, more preferably less than 0.001% by mass, even more preferably less than 0.0001% by mass, and may even be 0% by mass, based on the total mass of the coloring solution.

[0068] The ceramics colored by the coloring solution of the present invention are not particularly limited as long as they contain ceramics, and examples include those containing zirconia (also called "zirconium oxide" or "ZrO2"), alumina (also called "aluminum oxide" or "Al2O3"), feldspar glass, disilicate glass, porcelain, etc. Dental ceramics preferably contain zirconia and / or alumina, and more preferably contain zirconia as the main component. When dental ceramics contain zirconia as the main component, the zirconia content is more preferably 65% ​​by mass or more, particularly preferably 75% by mass or more, and most preferably 85% by mass or more.

[0069] The dental ceramics to be colored with the coloring solution of the present invention may be unfired or calcined, as long as they are before sintering. However, from the viewpoint of penetration of the coloring solution, if the dental ceramics contain zirconia as the main component, it is preferable that the dental ceramics be calcined zirconia.

[0070] Another embodiment of the present invention is a dental ceramic (calcined or uncalcined colored ceramic) on which a coloring component and a Zr component are supported on its surface. The content of the coloring component and the Zr component is not particularly limited as long as the effects of the present invention are achieved, and can be appropriately adjusted by the amount of coloring solution applied according to the desired intensity of color development after sintering. Furthermore, the support range of the coloring component and the Zr component can be adjusted not only on the outer surface but also inside the surface by utilizing capillary action through the application of the coloring solution of the present invention, etc., and by applying the coloring solution of the present invention, the components can penetrate into spaces communicating with the outside of the calcined or uncalcined ceramic, and the support can be adjusted not only on the outer surface but also inside the surface. Generally, support refers to a state in which the components are attached to a carrier, and in the present invention, it refers to a state in which the components are attached to the ceramic by adsorption or other means.

[0071] The dental ceramics of the present invention can be given the desired color tone required for dental applications after firing, and their strength can be improved.

[0072] As described above, the ceramic calcined body or uncalcined body is more preferably one that contains zirconia as the main component. Zirconia will be described below. In this invention, the calcined body before coloring with the coloring solution is simply referred to as "ceramic calcined body," and the calcined body after coloring is referred to as "colored ceramic calcined body" to distinguish them. The coloring solution of this invention can also be used to color an uncalcined zirconia body, in which case a sintered zirconia body is manufactured without going through calcination. When such a sintered body is assumed, the conditions described below regarding the zirconia calcined body can be applied similarly to a preferred embodiment of the uncalcined zirconia body.

[0073] This invention describes the zirconia calcined body. The zirconia calcined body mainly consists of zirconia (ZrO2: zirconium oxide), is molded according to the intended dental product, and calcined. The zirconia calcined body refers, for example, to a block formed from zirconia particles (powder) that have not been completely sintered. The main component should be 50% by mass or more. The zirconia content in the zirconia calcined body according to the present invention is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more. For example, if used in dental prostheses or dental implant products, the zirconia calcined body can be produced by press-molding zirconia powder using known techniques to obtain a disc or block, and then performing calcination or other treatments. The density of the zirconia calcined body is 2.7 g / cm³. 3 The above is preferable. Furthermore, the density of the zirconia calcined material is 4.0 g / cm³. 3 The following is preferable: 3.8 g / cm³ 3 The following is more preferable: 3.6 g / cm³ 3 The following is even more preferable. This density range facilitates molding. The density of the calcined body can be calculated, for example, as (mass of calcined body) / (volume of calcined body). The three-point bending strength of the zirconia calcined body is preferably 15 to 70 MPa, more preferably 18 to 60 MPa, and even more preferably 20 to 50 MPa. The bending strength can be measured using a test specimen measuring 5 mm × 10 mm × 50 mm, in accordance with ISO 6872:2015 except for the size of the test specimen. The surface and C-face (the surface where the corner of the test specimen is chamfered at a 45° angle) of the test specimen are finished longitudinally with 600-grit sandpaper. The test specimen is positioned so that its widest surface faces the vertical direction (direction of load). In the bending test measurement, the span is 30 mm and the crosshead speed is 0.5 mm / min.

[0074] In calcined zirconia, zirconia powder, and molded articles of zirconia powder, the primary crystal system of zirconia is preferably monoclinic. In the present invention, "the primary crystal system is monoclinic" means the proportion of monoclinic crystals in zirconia calculated by the following formula (1) relative to the total amount of all crystal systems (monoclinic, tetragonal, and cubic) in the zirconia. m This refers to materials in which monoclinic crystals account for 50% or more of the total. In calcined zirconia, zirconia powder, and molded articles of zirconia powder, the proportion of monoclinic crystals in the zirconia calculated by the following formula (1) is f. m The proportion of monoclinic, tetragonal, and cubic crystal systems is preferably 55% or more, more preferably 60% or more, even more preferably 70% or more, even more preferably 75% or more, particularly preferably 80% or more, even more preferably 85% or more, and most preferably 90% or more. m This can be calculated from the following equation (1) based on the peaks of the X-ray diffraction (XRD) pattern by CuKα rays. It should be noted that the aforementioned main crystal system may contribute to the higher shrinkage temperature and shorter firing time during calcination of the zirconia calcined body.

[0075] In the calcined zirconia body of the present invention, tetragonal and cubic crystal peaks do not need to be substantially detected. That is, the proportion of monoclinic crystals f m This can be considered 100%.

[0076]

number

[0077] In equation (1), I m (111) and I m (11-1) shows the peak intensities of the (111) plane and the (11-1) plane of the monoclinic crystal system of zirconia, respectively. t (111) represents the peak intensity of the (111) plane in the tetragonal crystal system of zirconia. c (111) represents the peak intensity of the (111) plane in the cubic crystal system of zirconia.

[0078] In the present invention, the calcined zirconia preferably contains a stabilizer capable of suppressing the phase transition of zirconia. For example, it is preferable to include a stabilizer capable of suppressing the phase transition of zirconia in the zirconia before calcination.

[0079] Examples of stabilizers that can suppress the phase transition of zirconia include yttrium oxide (Y2O3) (hereinafter referred to as "yttria"), calcium oxide (CaO), magnesium oxide (MgO), yttria, cerium oxide (CeO2), scandium oxide (Sc2O3), niobium oxide (Nb2O5), lanthanum oxide (La2O3), erbium oxide (Er2O3), and praseodymium oxide (Pr6O). 11 Examples of oxides include samarium oxide (Sm2O3), europium oxide (Eu2O3), and thulium oxide (Tm2O3), with yttria being preferred. These may be used individually or in combination of two or more. In one preferred embodiment, the coloring solution contains zirconia as the main component of the dental ceramic to be colored, and further contains yttria as a stabilizer, with the stabilizer being substantially yttria alone. In the above preferred embodiment, "substantially yttria alone" means that the content of stabilizers other than yttria is less than 0.1 mol%, preferably 0.05 mol% or less, more preferably 0.01 mol% or less, and even more preferably 0.001 mol% or less, based on a total of 100 mol% of zirconia and stabilizers.

[0080] If a stabilizer is included, the stabilizer content is preferably 0.1 to 18 mol%, more preferably 1 to 15 mol%, and even more preferably 1.5 to 10 mol%, based on a total of 100 mol% of zirconia and stabilizer.

[0081] The calcined zirconia body in the present invention may optionally contain colorants (including pigments, composite pigments, and fluorescent agents), alumina (Al2O3), titanium dioxide (TiO2), silica (SiO2), etc. These components may be used individually or in combination of two or more. Examples of the pigment include oxides of at least one component selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Zn, Y, Zr, Sn, Sb, Bi, Ce, Pr, Sm, Eu, Gd, Tb, and Er. Examples of the composite pigment include (Zr,V)O2, Fe(Fe,Cr)2O4, (Ni,Co,Fe)(Fe,Cr)2O4·ZrSiO4, (Co,Zn)Al2O4, etc. Examples of the fluorescent agents include Y2SiO5:Ce, Y2SiO5:Tb, (Y,Gd,Eu)BO3, Y2O3:Eu, YAG:Ce, ZnGa2O4:Zn, and BaMgAl. 10 O 17 Examples include the EU.

[0082] The general method for manufacturing zirconia calcined bodies according to the present invention is described below. First, granules composed of zirconia raw materials containing a stabilizer (preferably zirconia particles whose main crystal system is monoclinic) are prepared and press-molded into shapes such as blocks or discs. Next, the molded body is subjected to CIP (Cold Isostatic Pressing) treatment as needed. The applied pressure at this time is, for example, 50 to 500 MPa. Then, calcination treatment is performed. Calcination is carried out by gradually raising the temperature from room temperature to 800 to 1200°C and holding it at the above temperature for about 1 to 6 hours to obtain a zirconia calcined body. The obtained zirconia calcined body is machined using conventionally known equipment according to the final dental product. For example, if the dental product is a dental prosthesis, it is machined into a tooth crown shape using CAD / CAM or the like.

[0083] Commercially available zirconia calcined bodies may be used. Examples of commercially available products include "Noritake Katana (registered trademark) Zirconia" (model numbers: Disc UTML, Disc STML, Disc ML, Disc HT, Disc LT) (all manufactured by Kuraray Noritake Dental Co., Ltd.).

[0084] The method for producing a colored zirconia calcined body according to the present invention includes the step of incorporating the zirconia coloring solution into the zirconia calcined body after machining. Methods for incorporating the zirconia coloring solution include, for example, applying it to the zirconia calcined body using a brush, immersing the zirconia calcined body in a container containing the coloring solution, or spraying it onto the zirconia calcined body using a sprayer. Conventionally known instruments and apparatus can be used. In the case of producing a zirconia sintered body directly from an uncalcined body without including a calcination step, the zirconia coloring solution may be incorporated into the uncalcined zirconia body after machining.

[0085] The present invention further includes a zirconia sintered body obtained by sintering the colored zirconia calcined body. The method for manufacturing the zirconia sintered body includes a step of firing the colored zirconia calcined body. The firing temperature (maximum firing temperature) can be appropriately changed depending on the type of zirconia and is not particularly limited as long as the coloring component develops color, but 1350°C or higher is preferred, 1450°C or higher is more preferred, and 1500°C or higher is even more preferred. The upper limit of the firing temperature is not particularly limited, but for example, 1600°C or lower is preferred. The zirconia sintered body includes not only a sintered body obtained by sintering molded zirconia particles under normal pressure or without pressure, but also a sintered body densified by high-temperature and high-pressure treatment such as HIP (Hot Isostatic Pressing).

[0086] The content of the stabilizer in the zirconia sintered body in the present invention can be measured, for example, by inductively coupled plasma (ICP) emission spectroscopy, X-ray fluorescence analysis, or the like.

[0087] A zirconia sintered body preferably has at least one of partially stabilized zirconia and fully stabilized zirconia as a matrix phase. In a zirconia sintered body, the main crystalline phase of zirconia is at least one of tetragonal and cubic crystal systems. A zirconia sintered body may contain both tetragonal and cubic crystal systems. It is preferable that a zirconia sintered body substantially does not contain monoclinic crystal systems. Zirconia that has been partially stabilized by adding a stabilizer is called partially stabilized zirconia (PSZ), and zirconia that has been completely stabilized is called fully stabilized zirconia.

[0088] The present invention encompasses dental products made of the zirconia sintered body. Examples of such dental products include dental prostheses, orthodontic products, or dental implant products. Examples of such dental prostheses include zirconia inlays, onlays, laminate veneers, and crowns.

[0089] In the above embodiment, the type and content of each component can be changed as appropriate, and any component can be added, deleted, or otherwise modified. Furthermore, in the above embodiment, the composition and property values ​​of the coloring solution can be changed and combined as appropriate.

[0090] The present invention includes embodiments that combine the above configurations in various ways, within the technical scope of the present invention, as long as they achieve the effects of the present invention. [Examples]

[0091] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0092] [Examples 1-13 and Comparative Examples 1-3] The colored solutions for each example and comparative example were prepared as follows, and their properties were evaluated. The results are shown in Tables 1 and 2.

[0093] [Preparation of colored solution] A colored solution was prepared by mixing the components listed in Tables 1 and 2 in the quantities indicated in the tables at room temperature. The molar concentration of the Zr component in the colored solution was measured by inductively coupled plasma (ICP) emission spectroscopy (SPS3500: Hitachi High-Tech Science Corporation).

[0094] [Manufacturing of zirconia calcined bodies] Next, a method for manufacturing a calcined zirconia body to which the coloring solution is applied will be described.

[0095] First, a zirconia powder containing a stabilizer was prepared. A mixture was prepared by adding 9.9% by mass (5.5 mol%) of yttria as a stabilizer to 90.1% by mass of monoclinic zirconia powder, which is the main crystalline system. Next, this mixture was added to water to prepare a slurry, which was wet-milled and mixed in a ball mill until the average particle size was 0.13 μm or less. The slurry after milling was dried in a spray dryer, and the resulting powder was calcined at 950°C for 2 hours to prepare a powder (primary powder). The average particle size can be determined by laser diffraction scattering. Specifically, the laser diffraction scattering method can be used, for example, to measure the particle size by volume using a laser diffraction particle size distribution analyzer (SALD-2300: manufactured by Shimadzu Corporation) with a 0.2% aqueous sodium hexametaphosphate solution as the dispersion medium.

[0096] Water was added to the obtained primary powder to prepare a slurry, which was then wet-milled and mixed in a ball mill until the average particle size was 0.13 μm or less. After grinding, a binder was added to the slurry and dried in a spray dryer to produce a powder (secondary powder). The prepared secondary powder was used as the raw material powder in the production of the zirconia calcined body described later.

[0097] Next, the method for manufacturing a zirconia calcined body will be described. 1.32 g of the raw material powder was filled into a mold with a diameter of 19 mm, and primary press molding was performed using a uniaxial press molding machine at a surface pressure of 57.5 kN for 20 seconds. The resulting primary press-molded body was fired at 1000°C for 2 hours to produce a zirconia calcined body.

[0098] [Measurement of Chromaticity of Sintered Body] After applying the prepared coloring solution to the manufactured zirconia green body with a brush, it was fired under the firing conditions described in Tables 1 and 2 to obtain a zirconia sintered body. The obtained zirconia sintered body was polished into a disc with a diameter of 15 mm and a thickness of 1.2 mm, and using a spectrocolorimeter (trade name "Crystal Eye") manufactured by Olympus Corporation, in measurement mode 7band, with an LED light source and a white background, L * a * b * The chromaticity in the color system (JIS Z 8781-4:2013 Colorimetry - Part 4: CIE 1976 L * a * b * color space) was measured (n = 3). The average values of the measurement results are shown in Tables 1 and 2.

[0099] [Measurement of Transparency of Sintered Body] After applying the prepared coloring solution to the manufactured zirconia green body with a brush, it was fired under the firing conditions described in Tables 1 and 2 to obtain a sintered body. The obtained sintered body was polished into a disc with a diameter of 15 mm and a thickness of 1.2 mm, and using a spectrocolorimeter (trade name "Crystal Eye CE100-DC / JP", light source: 7band LED light source) manufactured by Olympus Corporation, the lightness (Lw * ) when measuring the chromaticity with a white background, and for the same test piece, with the same measuring device, measurement mode, and light source, the lightness (Lb * ) when measuring the chromaticity with a black background were measured, and the difference between the two (ΔL * =(Lw * )-(Lb * )) was defined as the transparency (ΔL * ) (n = 3). The average values of the calculated values are shown in Tables 1 and 2. The transparency is preferably in the range of 3 to 20, more preferably in the range of 5 to 19, and even more preferably in the range of 6 to 18.

[0100] [Measurement of Biaxial Flexural Strength of Sintered Body] The prepared coloring solution was applied to the calcined zirconia body using a brush, and then fired under the firing conditions described in Tables 1 and 2 to obtain a sintered body with a diameter of 15 mm and a thickness of 1.2 mm. The biaxial bending strength of the obtained sintered body was measured in accordance with JIS T 6526:2012 using a Shimadzu Corporation Autograph tabletop universal precision testing machine (product name "AG-I 100kN") at a crosshead speed of 0.5 mm / min (n=5). The average values ​​of the measured values ​​are shown in Tables 1 and 2. Furthermore, using a zirconia sintered body that was not colored with a coloring solution (Comparative Example 1) as a reference, the rate of change in biaxial bending strength was calculated using the following formula. Change in biaxial bending strength (%) = {(Biaxial bending strength of sintered body coated with colored solution and fired - Biaxial bending strength of uncolored zirconia sintered body) / Biaxial bending strength of uncolored zirconia sintered body} × 100

[0101] [Table 1]

[0102] [Table 2]

[0103] As a result, Examples 1 to 13, which were coated with the coloring solution of the present invention, showed improved strength of the zirconia after firing compared to Comparative Example 1, which was not coated with the coloring solution, and Comparative Examples 2 to 3, which were coated with a coloring solution that did not contain Zr. In particular, comparisons between Examples 1 to 3 and Comparative Example 2, and between Examples 5 to 7 and Comparative Example 3, showed that there was almost no difference in color and transparency after firing depending on the presence or content of the Zr component. This confirmed that the coloring solution of the present invention has little effect on the color tone imparted to zirconia, meaning that it can impart the desired color tone while also improving the strength of the zirconia after firing. [Industrial applicability]

[0104] The coloring solution of the present invention can impart a desired color to dental ceramics and improve their strength, making it suitable for use as a coloring solution for dental ceramics. In particular, as the demand for ceramic crowns continues to increase and individual aesthetic requirements are rising, the frequency of use of dental ceramic coloring solutions is expected to increase, making the dental ceramic coloring solution of the present invention particularly useful.

Claims

1. It contains a coloring component, a solvent, and a Zr component. The solvent satisfies any of the following conditions (1) to (3): (1) Contains no organic solvents and only water; (2) Contains no water and only organic solvents; (3) Water and organic solvents; The solubility parameter of the organic solvent in (2) to (3) above is 17.7 (MPa). 1 / 2 That's all. The organic solvent in (2) to (3) above is at least one selected from the group consisting of alcohols, glycols, triols, and ketones. The coloring component contains at least one component selected from the group consisting of Al, K, Cr, Fe, Na, V, Gd, La, Yb, Tm, Ni, Mn, Co, Nd, Pr, Cu, Tb, and Er components, but does not contain component Y, and A coloring solution for coloring dental zirconia calcined bodies that does not contain stabilizers capable of suppressing the phase transition of zirconia.

2. The colored solution according to claim 1, wherein the coloring component is an ion or a complex.

3. The colored solution according to claim 1 or 2, wherein the coloring component comprises at least one component selected from the group consisting of Al, K, Cr, Fe, Na, V, Ni, Mn, Co, Nd, Pr, Cu, Tb, and Er components.

4. The colored solution according to any one of claims 1 to 3, wherein the Zr component is an ion or a complex.

5. The colored solution according to any one of claims 1 to 4, wherein the Zr component comprises at least one selected from the group consisting of zirconium chloride hydrate, zirconium acetate, zirconium oxide hydrate, and zirconium nitrate hydrate.

6. The colored solution according to any one of claims 1 to 5, wherein the content of the Zr component is 0.0650 to 0.900 mol / L as Zr ions.

7. The colored solution according to any one of claims 1 to 6, wherein the solvent content is 45 to 99% by mass.

8. The solubility parameter of the organic solvent in (2) to (3) is 18.0 (MPa) 1 / 2 The colored solution according to claim 7.

9. The colored solution according to claim 7 or 8, wherein the alcohol of the organic solvent is at least one selected from the group consisting of methanol, ethanol, 1-propanol, 2-propanol, isopropanol, 1-butanol, 2-butanol, 1-heptanol, 2-heptanol, 3-heptanol, 2-hexanol, 3-hexanol, 2-methyl-1-pentanol, 3-methyl-1-pentanol, 4-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 2,2-dimethyl-1-butanol, and 2-ethyl-1-butanol.

10. The coloring solution according to any one of claims 1 to 9, wherein the coloring component further contains component V.

11. The coloring solution according to any one of claims 1 to 10, wherein the coloring component further contains a Ni component.

12. The coloring solution according to any one of claims 1 to 11, wherein the coloring component further contains an Al component.

13. The coloring solution according to any one of claims 1 to 12, wherein the coloring component further contains a Co component.

14. The coloring solution according to any one of claims 1 to 13, wherein the coloring component further contains an Er component.

15. The coloring solution according to any one of claims 1 to 14, wherein the coloring component further contains a Cr component.

16. The coloring solution according to any one of claims 1 to 15, wherein the coloring component further contains a Mn component.

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