Dental ceramic coloring solution

Abstract

The present invention provides a dental ceramic coloring solution which is capable of providing a dental ceramic with a desired yellow tinge so that the dental ceramic colored with the coloring solution does not discolor even if baked after building up a ceramic material thereon. The present invention relates to a coloring solution for coloring a dental ceramic, said coloring solution containing a coloring component and a solvent, wherein the coloring component contains a V component.

Description

[Technical Field]

[0001] The present invention relates to a dental ceramic coloring solution, and more particularly to a dental ceramic coloring solution suitable for use in producing dental prostheses such as inlays, onlays, veneers, crowns, bridges, abutments, dental posts, dentures, denture bases, and implant components (fixtures and abutments) machined using a dental CAD / CAM system. [Background technology]

[0002] Traditionally, metals have been commonly used for dental products (e.g., dental prostheses such as typical veneers, dental crowns, crowns, and dental implants, as well as orthodontic products and dental implant products). However, metals have the drawback of being clearly different in color from natural teeth, lacking aesthetic appeal, and can also cause allergies due to metal elution. Therefore, to solve the problems associated with the use of metals, ceramic materials such as aluminum oxide (alumina) and zirconium oxide (zirconia) have been used in dental products as alternatives to metals. Zirconia, in particular, is strong and relatively aesthetically pleasing, and demand for it has been increasing, especially as prices have fallen in recent years.

[0003] In recent years, CAD / CAM systems have become widespread, in which the final shape of a dental prosthesis or a large implant prosthesis is designed by computer and then cut using a milling machine. Zirconia is commonly used as the material for the mill blanks, the cutting material used in CAD / CAM systems, due to the emphasis on aesthetics. In particular, zirconia, which has different colors arranged vertically in the thickness direction to reproduce natural tooth color and meet aesthetic requirements, has recently become popular. For colors that are difficult to reproduce, high aesthetic requirements have been met by further coating and coloring dental porcelain on the ceramic surface machined to the shape of the dental prosthesis.

[0004] However, the technique of coating and coloring dental porcelain requires specialized knowledge and excellent skills. Specifically, coloring with dental porcelain requires the reproduction of the precise shape and structure of natural teeth by building up the dental porcelain, as well as the development of highly aesthetic colors, which requires a high level of skill.

[0005] To avoid the problems caused by the use of dental porcelain, a technique is commonly used in which a coloring solution is applied to dental ceramics to give them a more aesthetic appearance similar to natural teeth, instead of or before the coloring with dental porcelain, which requires skill.

[0006] Natural teeth are usually yellowish or reddish in color. The following techniques have been proposed to color ceramics yellowish.

[0007] For example, Patent Document 1 discloses Pr and Tb components as components that impart a yellowish tint to metal oxide ceramics. However, although it is possible to color zirconia using a coloring solution containing these coloring components, it has been found that when zirconia colored by this method is subsequently layered and fired with porcelain, the yellowish color fades (discoloration) due to the influence of anti-yellowing agents such as antimony compounds or cerium compounds added to the porcelain.

[0008] Furthermore, Patent Document 2 discloses a composite oxide of zirconium and vanadium as a colorant. However, although this composite oxide can be colored when mixed with a powder, it is insoluble in solvents that can be used in coloring solutions, and when used as a coloring component in a coloring solution, it is unable to uniformly color the zirconia, and therefore could not be used in coloring solutions. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-314536 [Patent Document 2] International Publication No. 2016 / 068288 Summary of the Invention [Problem to be solved by the invention]

[0010] As described above, Patent Document 1 does not consider the poor color development that occurs when porcelain is built up, and there is a problem of discoloration of ceramics. Therefore, there is room for improvement when building up porcelain.

[0011] In addition, Patent Document 2 uses color-developing zirconia as a raw material compact to incorporate a colorant containing a composite oxide, thereby achieving color development. Patent Document 2 solves the problem of discoloration, a type of color development defect that occurs when porcelain containing an anti-yellowing agent is built up on a zirconia sintered body, without using a coloring solution by using color-developing zirconia as a raw material compact. Patent Document 2 is concerned with the relationship between the zirconia substrate and the porcelain containing an anti-yellowing agent. Therefore, Patent Document 2 assumes that the zirconia substrate contains a predetermined colorant, and does not suggest coloring with a coloring solution in addition to building up the porcelain. Because the zirconia sintered body itself has the color tone of natural teeth (paragraph 0116 of Patent Document 2), any additional coloring other than the polishing and glossing provided by the porcelain would complicate the manufacturing process, and further coloring is not considered to be necessary in terms of industrial productivity.

[0012] As in Patent Document 2, when the zirconia substrate contains a predetermined colorant, the zirconia sintered body itself has the color tone of natural teeth, and color change is small even when porcelain is baked onto it. Thus, in Patent Document 2, the color of the zirconia substrate is adjusted by the colorant contained in the substrate, and the color of the zirconia sintered body is predetermined. To change the color in response to a patient's request for correction, the zirconia sintered body must be re-manufactured from zirconia powder. Therefore, considering the possibility of easily reproducing the zirconia sintered body when coloring needs to be redone, we investigated a method for easily coloring the zirconia sintered body with a coloring solution when the substrate (e.g., a zirconia calcined body) used in the cutting process of a dental prosthesis contains almost no colorant.

[0013] On the other hand, even when dental ceramics are colored with a coloring solution, the problem of discoloration due to the influence of anti-yellowing agents such as antimony compounds or cerium compounds contained in the porcelain has not been solved.

[0014] Therefore, an object of the present invention is to provide a coloring solution that can impart a desired yellowish hue to dental ceramics without causing discoloration even when dental ceramics colored with the coloring solution are built up and fired with porcelain containing an anti-yellowing agent containing antimony oxide and / or cerium oxide. Another object of the present invention is to provide a coloring solution that is easy to handle and can simply impart a desired yellowish hue to dental ceramics. [Means for solving the problem]

[0015] As a result of extensive research into solving the above problems, the present inventors discovered that a colored solution containing component V can solve the above problems, and after further investigation, they have completed the present invention.

[0016] That is, the present invention includes the following inventions. [1] A coloring component and a solvent are included, A coloring solution for coloring dental ceramics, wherein the coloring component includes component V. [2] The coloring solution according to [1], wherein the component V is an ion or a complex. [3] The coloring solution according to [1] or [2], wherein the V component has a valence of +IV and / or +V. [4] The coloring solution according to any one of [1] to [3], wherein the component V is an oxide vanadium compound. [5] The coloring solution according to any one of [1] to [4], wherein the component V is a component derived from at least one selected from the group consisting of vanadyl oxalate, vanadyl nitrate, and vanadyl acetate. [6] The coloring solution according to any one of [1] to [5], wherein the content of the V component is 0.0100 to 45.0 mmol / L in terms of V ions. [7] Regarding the L*a*b* color system (L*, a*, b*) of dental ceramics after coloring and sintering, a* is between -20 and 20, The coloring solution according to any one of [1] to [6], wherein b* is 5 to 60. [8] The coloring solution according to any one of [1] to [7], wherein L* is 60 to 95 in (L*, a*, b*) according to the L*a*b* color system. [9] The coloring solution according to any one of [1] to [8], wherein the solvent contains water and / or an organic solvent.

[10] The coloring solution according to [9], wherein the organic solvent contains at least one selected from the group consisting of alcohols, glycols, triols, and ketones.

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

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

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

[11] , wherein the coloring component contains a Cr component.

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

[12] , further containing a Zr component.

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

[13] , which does not contain a Pr component or a Tb component.

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

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

[16] Dental ceramics with V component supported on the surface.

[17] The dental ceramics according to

[16] , wherein the V component is an ion or a complex.

[18] The dental ceramic according to

[16] or

[17] , wherein the dental ceramic contains zirconia as a main component. [Effects of the Invention]

[0017] The dental ceramic coloring solution of the present invention can impart a desired yellowish color tone to dental ceramics without fading even when the dental ceramics colored with the coloring solution are fired after being built up with a ceramic material containing an anti-yellowing agent containing antimony oxide and / or cerium oxide. Further, the present invention can provide a coloring solution that is excellent in handleability and can easily impart a desired yellowish color tone to dental ceramics. Furthermore, the dental ceramic coloring solution of the present invention can suppress a decrease in the strength of dental ceramics. In addition, in the present invention, when remanufacturing of a dental prosthesis is required due to a change in color tone, zirconia not containing a predetermined colorant can be easily machined by a CAD / CAM system using data of a dental prosthesis having the same shape as the base material, and can be easily changed to a different color tone.

Embodiments for Carrying Out the Invention

[0018] The present invention is a coloring solution for coloring dental ceramics, which contains a coloring component and a solvent, and the coloring component contains a V component.

[0019] <V component> First, the V (vanadium) component contained in the coloring solution of the present invention will be described. The V component contains ions or complexes of V and is contained for coloring dental ceramics with a yellowish color tone.

[0020] Although the reason why the application of a dental ceramics coloring solution containing component V can impart a desired yellow hue to dental ceramics without discoloration even when dental ceramics colored with the coloring solution are built up and fired with porcelain containing an anti-yellowing agent containing antimony oxide and / or cerium oxide is unclear, the inventors speculate as follows: That is, with general composite oxide pigments, due to their good stability, it is difficult to form a solid solution with dental ceramics, and in some cases color development is insufficient or a stable color tone cannot be obtained, whereas component V of the present invention is ionized or complexed, and therefore, strong and stable color development can be obtained even when added in small amounts, making it less susceptible to the influence of other components and suppressing discoloration.

[0021] The ion or complex of V may be added to the coloring solution as a salt containing the cation and anion of V, or as a complex containing V and a ligand, such as 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.

[0022] As the vanadium compound, from the viewpoint of stability and ease of handling, +IV and / or +V valent vanadium compounds are preferred, and vanadium oxide compounds are more preferred.

[0023] Specific examples of compounds to be added to the coloring solution of the present invention to incorporate the above ions or complexes include trivalent vanadium compounds such as vanadium(III) chloride anhydrous, vanadium(III) chloride hydrate (hexahydrate), divanadium(III) trioxide, and vanadium(III) bromide; vanadium acetylacetonate, vanadyl acetylacetonate, vanadyl stearate, vanadium naphthenate, vanadium benzoylacetonate, vanadyl oxalate, bis(maltolate)oxovanadium(IV), oxobis(1-phenyl-1,3-butanedionate)vanadium, vanadium(V) oxytriisopropoxide, vanadium(V) oxide trichloride, vanadium(IV) oxide dichloride, vanadium disilicide, divanadium(IV) tetroxide, divanadium(V) pentoxide, tetravanadium triiron oxide, vanadyl(IV) sulfate hydrate, oxalic acid, Vanadyl acid (oxovanadium(IV) oxalate), vanadyl(IV) acetate (VO[OC(O)CH3]2), vanadyl(V) nitrate (VO(NO3)3), vanadyl glycolate, vanadium selenide, vanadium carbide (VC), vanadium nitride (VN), potassium divanadate, potassium vanadate, potassium metavanadate (KVO3)(V), sodium metavanadate (NaVO3)(V), sodium divanadate Examples of vanadium compounds include vanadium compounds with a valence of +4 or +5, such as vanadium (Na4V2O7), sodium vanadate (Na3VO4), sodium vanadate hydrate, lithium metavanadate (LiVO3), rubidium divanadate (Rb4V2O7), rubidium metavanadate (RbVO3), rubidium vanadate (Rb3VO4), vanadium diboride, vanadium boride (VB), and vanadium(III) sulfide (V2S3). Among these, vanadyl oxalate, vanadyl nitrate, and vanadyl acetate are preferred because they can suppress discoloration and provide a coloring solution with excellent stability and ease of handling. The vanadium component may be used alone or in combination of two or more.

[0024] The content of the V component in the coloring solution is preferably 0.0100 to 45.0 mmol / L, more preferably 0.0200 to 40.0 mmol / L, in terms of V ions in the entire solution, from the viewpoint of yellow color development. Depending on the type of V component, it is even more preferably 0.0500 to 35.0 mmol / L from the viewpoint of excellent stability of the V component. Furthermore, from the viewpoint of excellent stability of the V component, in a preferred embodiment, the content of the V component in the entire solution may be 0.0100 to 15.0 mmol / L, or even 0.0200 to 10.0 mmol / L. When the V component content is 0.0100 mmol / L or more, the yellow color development is sufficient, satisfying high aesthetic requirements. When the V component content is 45.0 mmol / L or less, the yellow color development is prevented from becoming too strong, allowing natural tooth color to be reproduced. The content of the V component can be measured, for example, by inductively coupled plasma (ICP) emission spectroscopy, fluorescent X-ray analysis, etc. The content of the metal component in this specification can be measured by the above-mentioned methods.

[0025] The coloring solution of the present invention may contain other coloring components, such as metal ion solutions, as long as the effects of the present invention are not impaired.

[0026] The metal ion solution contains a coloring cation. The coloring cation is preferably an ion of at least one element selected from the group consisting of Al, K, Cr, Na, Y, Gd, La, Yb, Tm, Ni, Mn, Co, Nd, Cu, and Er, more preferably an ion of at least one element selected from the group consisting of Al, K, Cr, Na, La, Ni, Mn, Co, and Er, and even more preferably an ion of at least one element selected from the group consisting of Al, K, Cr, Na, Ni, Mn, Co, and Er. The metal ion solution may contain one of the cations alone or a combination of two or more cations.

[0027] The coloring cation may be added to the solvent described below as a salt containing the cation and an anion. - , 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.

[0028] In a preferred embodiment, the coloring component of the coloring solution contains a Ni component. The Ni component can reproduce a reddish-brown color tone, and by suppressing the brown and combining it with yellow, the desired dental standard color tone can be achieved. For example, using a coloring solution containing a Ni component can lower L* in the (L*, a*, b*) L*a*b* color system. Furthermore, using a coloring solution containing a Ni component can increase a*. Furthermore, using a coloring solution containing a Ni component can lower b*. Examples of nickel compounds include divalent, trivalent, and tetravalent nickel compounds, with divalent nickel compounds being preferred. Examples of Ni compounds 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 Ni component may be used alone, or two or more may be used in combination.

[0029] Another preferred embodiment is a coloring solution in which the coloring component contains a Cr component. The Cr component can reproduce a gray-green tone, and by suppressing the green and combining it with yellow, the 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 lower L* in the L*a*b* color system (L*, a*, b*). Furthermore, using a coloring solution containing a Cr component may increase a*. Furthermore, using a coloring solution containing a Cr component may lower b*. Examples of Cr components include chromium(III) chloride, chromium(III) chloride hydrate (hexahydrate), chromium(III) nitrate hydrate (nonehydrate), chromium(III) sulfate hydrate (n-hydrate), and chromium(III) acetate hydrate (monohydrate). Chromium(III) nitrate hydrate (nonehydrate), chromium(III) chloride hydrate (hexahydrate), and chromium(III) acetate hydrate (monohydrate) are preferred because of their excellent solubility in water and organic solvents. One Cr component may be used alone, or two or more Cr components may be used in combination.

[0030] The coloring solution of the present invention may contain other metal components as long as the effects of the present invention are not impaired. For example, if the coloring solution contains a Zr component, the strength of the ceramic to which the coloring solution is applied may be improved. In another embodiment, the coloring solution does not contain a Pr component or a Tb component.

[0031] The Zr component includes Zr ions or complexes. The Zr ions or complexes may be added to the coloring solution as a salt containing Zr cations and anions, or as a complex containing Zr and its ligands. Examples of the anions 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.

[0032] Specific examples of compounds that can be added to the coloring solution of the present invention to incorporate the above ions or complexes include zirconium chloride hydrate (IV), zirconium sulfide (IV), tetrakis(acetylacetonato)zirconium (IV), zirconium chloride (IV), zirconium octanoate (IV), zirconium oxide oleate (IV), dichlorobis(η5-cyclopentadienyl)zirconium (IV), zirconium oxide acetate (IV), zirconium oxide (IV) hydrate, zirconium oxide stearate (IV), zirconium oxide nitrate (IV) hydrate, zirconium (IV) n-butoxide, zirconium hydride (II), zirconium carbide (IV), dizirconium carbonate trioxide hydrate, zirconium nitride, ammonium hexafluorozirconate (IV), zirconium iodide (IV), zirconium oxide laurate (IV) (Zr(C 11 H 23 COO)2O), zirconium(IV) sulfate hydrate, zirconium(IV) dihydrogen phosphate oxide, etc. Among these, zirconium chloride oxide hydrate(IV), zirconium chloride(IV), zirconium acetate oxide(IV), zirconium oxide(IV) hydrate, zirconium nitrate oxide hydrate are preferred, and zirconium chloride oxide hydrate(IV) is more preferred. One Zr component may be used alone, or two or more Zr components may be used in combination.

[0033] The content of Zr 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 more, the effect of improving the strength of dental ceramics is obtained, and when it is 0.900 mol / L or less, the strength can be improved without deteriorating the aesthetics of the dental ceramics.

[0034] The coloring solution of the present invention preferably contains water and / or an organic solvent as a solvent. The water and / or organic solvent dissolves the coloring component and Zr component, improving the permeability of the coloring solution into dental ceramics. The content of the solvent in the coloring solution is preferably 45.0 to 99.9999 mass%, more preferably 60 to 99.9995 mass%, and even more preferably 75 to 99.9990 mass%.

[0035] 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, or pure water is preferred. The water content in the coloring solution is preferably 45.0 to 99.9999% by mass, more preferably 60 to 99.9995% by mass, and even more preferably 75 to 99.9990% by mass.

[0036] The organic solvent may be any solvent capable of dissolving the cation, and is preferably a mixture selected from alcohols, glycols, triols, ketones, and 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 propylene glycol 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, and 5-(benzyloxy)-1-pentanol;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-methyl-1,3-propanediol Examples of suitable organic solvents include diols such as 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, isobutyl ketone, diisobutyl ketone, and cyclohexanone. These organic solvents can be used alone or in combination of two or more. The organic solvent may also be used as a thickener, as described below, to adjust the viscosity.

[0037] The content of the solvent in the coloring solution is preferably 45.0 to 99.9999 mass %, more preferably 60.0 to 99.9995 mass %, and even more preferably 75.0 to 99.9990 mass %.

[0038] The coloring solution may contain a complexing agent to the extent that the effect of the present invention is not impaired. Adding a complexing agent may be beneficial for improving the storage stability of the coloring solution, accelerating the dissolution process of salts added to the coloring solution, and / or increasing the amount of salts that can be dissolved in the coloring solution.

[0039] The complexing agent is generally capable of forming a complex with the metal ions present in the coloring solution. The formed complex 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 the ions contained in the coloring solution, and good results can be obtained if the molar ratio of the complexing agent to the cations in the coloring solution is about 1, or about 2, or about 3 or more.

[0040] Examples of the complexing agent include N,N-di(2-hydroxyethyl)glycine, acetylacetonate, crown ether, cryptand, ethylenediamine triacetate and its salts, ethylenediaminetetraacetate and its salts, nitrilotriacetate and its salts, citric acid and its salts, triethylenetetraamine, porphine, polyacrylate, polyasparagine, acidic peptide, phthalocyanine, salicylate, glycinate, lactate, propylenediamine, ascorbate, oxalic acid and its salts, and mixtures thereof. The complexing agent can be used alone or in appropriate combination of two or more.

[0041] The content of the complexing agent in the coloring solution is not particularly limited as long as the effects of the present invention are achieved. For example, it is preferable to contain an amount sufficient to dissolve the cations in the solution or prevent precipitation of these cations. Specifically, the content in the coloring solution is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.10% by mass or more. There is no specific upper limit to the content, but it is preferably 50% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less. 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, excess complexing agent itself may remain undissolved.

[0042] The pH of the coloring 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, when the coloring solution is an aqueous solution, the pH is preferably 0 to 9. Furthermore, when the coloring solution does not contain a complexing agent, the pH is preferably 0 to 6, and when it contains a complexing agent, the pH is preferably 3 to 9. The pH can be measured using a commercially available pH meter (for example, the compact pH meter LAQUA twin manufactured by Horiba, Ltd.).

[0043] The coloring solution of the present invention preferably has an appropriate viscosity so that the required amount of solution can be applied to the ceramic surface and can also migrate into the pores of an unsintered ceramic body (also referred to herein as a "molded body") or a calcined ceramic body. The appropriate viscosity at 20°C is, for example, preferably 0.1 to 10,000 mPa, more preferably 0.5 to 6,000 mPa, and even more preferably 1 to 3,000 mPa. If the viscosity is too high, the coloring solution may not be able to be absorbed into the pores of the unsintered ceramic body or the calcined ceramic body. The method for measuring viscosity is not particularly limited, but it can be measured at 25°C using a Brookfield viscometer.

[0044] The colored solution of the present invention may contain a thickener to give it an appropriate viscosity, provided that the effect of the present invention is not impaired.

[0045] The thickener may be selected from the organic solvents described above to adjust the viscosity, or may be selected from the thickeners described below. Examples of thickeners other than the organic solvents 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 thickeners can be used alone or in appropriate combinations of two or more.

[0046] The content of the thickener in the colored solution of the present invention is preferably 0.01 to 10% by mass, more preferably 0.02 to 8% by mass, and even more preferably 0.05 to 5% by mass.

[0047] The coloring solution of the present invention may contain other additives as long as they do not impair the effects of the present invention.

[0048] Examples of the additives include stabilizers (e.g., methoxyphenol, hydroquinone, topanol A (2,4-dimethyl-6-tert-butylphenol), and mixtures thereof (excluding stabilizers capable of suppressing the phase transition of zirconia)), buffers (e.g., acetates, amino buffers, and mixtures thereof), preservatives (e.g., sorbic acid, benzoic acid, and mixtures thereof), and mixtures thereof. One type of additive may be used alone, or two or more types may be used in combination.

[0049] The content of the additive in the colored solution of the present invention can be, for example, 0.01 to 10% by mass, or may be 0.05 to 5% by mass, or may be 0.1 to 3% by mass.

[0050] The coloring solution of the present invention may contain, as its coloring component, a colorant that is decolorized after calcination of zirconia. The colorant that is decolorized after calcination of zirconia is not limited as long as it is decolorized after calcination of zirconia and satisfies the color difference before and after calcination, and examples thereof include organic dyes.

[0051] The organic dye is not particularly limited as long as it has a chromophore and is soluble in the coloring solution. However, aromatic organic dyes, i.e., organic dyes containing one or more optionally substituted aromatic groups, are preferred, and aromatic organic dyes having an auxochrome 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 of the chromophore include a nitro group, an azo group, a ketimide group (>C=N-), a carbonyl group, a carbon-carbon double bond, a carbon-carbon triple bond, a carbon-nitrogen multiple bond, a thiocarbonyl group, a nitroso group, and an azoxy group. The organic dye may contain one of these atomic groups alone or in combination with two or more of them. Examples of the auxochrome include a hydroxyl group, an amino group, a carboxyl group, a sulfone group, and a halogen atom. The organic dye may contain one of these auxochromes alone or in combination with two or more of them.

[0052] Furthermore, since colorants that are harmful or toxic to humans cannot be used as colorants to be decolorized after firing of zirconia, food colorants are preferred as the organic colorants, and food colorants that dissolve in the coloring solution are more preferred. Examples of such food colorants include organic colorants containing two or more aromatic groups, such as Yellow No. 4 (tartrazine), Yellow No. 5 (Sunset Yellow FCF), Red No. 2 (amaranth), Red No. 102 (New Coccine), Blue No. 1 (Brilliant Blue FCF), Blue No. 2 (indigo carmine), Green No. 3 (Fast Green FCF), and Red No. 102 (New Coccine); Acid Red 289, Bromopyrogallol Red, Rhodamine B, Rhodamine 6G, Rhodamine 6GP, Rhodamine 3GO, Rhodamine 123, Eosin (Eosin B, Eosin Y), Fluorescein, and Fluorescein Isothiocyanate. Examples of suitable organic dyes include organic dyes containing a condensed aromatic group with a xanthene nucleus (xanthene dyes); cochineal dyes (carminic acid dyes); beet red (main components: isobetanin and betanin), betanin, isobetanin, probetanin, neobetanin, and other betalain dyes. Preferred are organic dyes containing two or more aromatic groups and having a ketimide group or an azo group as a chromophore, such as Yellow No. 4 (tartrazine), Yellow No. 5 (Sunset Yellow FCF), Red No. 2 (Amaranth), Red No. 102 (New Coccine), Blue No. 1 (Brilliant Blue FCF), Green No. 3 (Fast Green FCF), and isobetanin. Furthermore, the colorant (A) can be changed depending on the content of the stabilizer for the zirconia calcined body to which the coloring solution of the present invention is applied. In a preferred embodiment, the colorant (A) is an organic dye containing two or more aromatic groups, a ketimide group or an azo group as a chromophore, and a sulfone group as an auxochrome. In this specification, the term "aromatic group" includes aromatic groups whose ring structure is composed only of carbon atoms and heteroaromatic groups whose ring structure contains an element other than carbon (oxygen, nitrogen, etc.). Colorants that decolorize after firing of zirconia can be used alone or in appropriate combinations of two or more.Furthermore, the coloring intensity of the colorant that is decolorized after calcining zirconia varies 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 shows an appropriate coloring intensity can be adopted and used depending on the type of colorant that is decolorized after calcining zirconia.

[0053] The content of the colorant that is decolorized after firing the zirconia is not particularly limited as long as the liquid components can develop color, but is preferably 0.009 to 3.0 mass% relative to the total mass of the coloring solution, more preferably 0.09 to 1.6 mass%, even more preferably 0.2 to 1.4 mass%, and particularly preferably 0.25 to 1.2 mass%.

[0054] In one embodiment, the coloring solution is one in which the coloring components are substantially free of colorants that decolorize after calcination of zirconia. The term "substantially free of colorants that decolorize after calcination of zirconia" means that the content of colorants that decolorize after calcination of zirconia is preferably less than 0.009% by mass, more preferably less than 0.001% by mass, and even more preferably less than 0.0001% by mass, relative to the total mass of the coloring solution, and may even be 0% by mass.

[0055] The coloring solution of the present invention can impart the yellow hue required for dental applications to dental ceramics. Regarding the chromaticity (L*, a*, b*) of the dental ceramics after coloring and sintering in the L*a*b* color system, a* is preferably -20 to 20, more preferably -18 to 18, and even more preferably -15 to 15. b* is preferably 5 to 60, more preferably 10 to 58, and even more preferably 12 to 55. L* is preferably 60 to 95, more preferably 68 to 92, and even more preferably 65 to 90. The method for measuring the chromaticity (L*, a*, b*) is as described in the Examples.

[0056] The dental ceramics to be colored with the coloring solution of the present invention are not particularly limited as long as they contain ceramics, and examples thereof include those containing zirconia (also called "zirconium oxide" or "ZrO"), alumina (also called "aluminum oxide" or "AlO"), 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.

[0057] The dental ceramics to be colored with the coloring solution of the present invention may be unsintered or calcined, as long as they are not yet sintered. However, from the viewpoint of penetration of the coloring solution, when the dental ceramics contain zirconia as a main component, it is preferable that the dental ceramics be calcined zirconia.

[0058] Another embodiment of the present invention is a dental ceramic (colored ceramic calcined or unsintered body) having a V component supported on its surface. The content of the V component is not particularly limited as long as the effects of the present invention are achieved, and can be appropriately adjusted by, for example, the amount of the coloring solution of the present invention applied, depending on the desired intensity of color development after sintering. Furthermore, the range of component V supported can be adjusted by, for example, applying the coloring solution of the present invention, utilizing capillary action to allow the V component to penetrate into spaces communicating with the outside of the ceramic calcined or unsintered body, thereby appropriately adjusting the support not only on the outermost surface but also inside the surface. Note that "supported" generally refers to a state in which the component is attached to a carrier; in the present invention, it refers to a state in which the component is attached to the ceramic by adsorption or the like.

[0059] The dental ceramics of the present invention can be imparted with a desired yellowish color tone while suppressing discoloration even when a porcelain containing an anti-yellowing agent including antimony oxide and / or cerium oxide is built up and fired.

[0060] As described above, the ceramic calcined body or green body preferably contains zirconia as a main component. Hereinafter, zirconia will be described. In the present invention, the calcined body before being colored with the coloring solution is simply referred to as a "zirconia calcined body," and the calcined body after coloring is simply referred to as a "colored zirconia calcined body." The coloring solution of the present invention can also be used to color a green zirconia body. In this case, a zirconia sintered body is produced without going through the calcination step. When such a sintered body is assumed, the conditions in the following description of the zirconia calcined body can be similarly applied to a preferred embodiment of the green zirconia body.

[0061] The zirconia calcined body of the present invention will now be described. The zirconia calcined body is composed primarily of zirconia (ZrO2: zirconium oxide), and refers to a body that is formed according to the desired dental product and then calcined. The zirconia calcined body refers, for example, to a body in which zirconia particles (powder) are formed into a block in a state where they are not completely sintered. The main component may be 50% by mass or more. The zirconia content in the zirconia calcined body of 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, when used in dental prostheses or dental implant products, the zirconia calcined body can be produced by press-molding zirconia powder using a known technique into a disk or block, which is then subjected to a process such as calcination. The density of the zirconia calcined body is 2.7 g / cm 3 The density of the zirconia calcined body is preferably 4.0 g / cm or more. 3 Less than 3.8 g / cm is preferred 3 Less than 3.6 g / cm is more preferable. 3The following is more preferable. A density within this range facilitates molding. The density of the calcined body can be calculated, for example, by dividing the mass of the calcined body by the volume of the 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 piece measuring 5 mm thick, 10 mm wide, and 50 mm long, in accordance with ISO 6872:2015, except for the size of the test piece. The test piece's face and C-face (the surface where the corners of the test piece are chamfered at a 45° angle) are sanded in the longitudinal direction with 600-grit sandpaper. The test piece is positioned so that the widest surface faces vertically (the load direction). The bending test measurement is performed with a span of 30 mm and a crosshead speed of 0.5 mm / min.

[0062] The predominant crystal system of zirconia in the calcined zirconia, zirconia powder, and zirconia powder compact is preferably monoclinic. In the present invention, the phrase "the predominant crystal system is monoclinic" refers to the ratio f of the monoclinic system in zirconia calculated by the following formula (1) to the total amount of all crystal systems (monoclinic, tetragonal, and cubic systems) in zirconia. m In calcined zirconia, zirconia powder, and zirconia powder compacts, the monoclinic fraction f in zirconia calculated by the following formula (1) is m 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 particularly preferably 85% or more, and most preferably 90% or more, based on the total amount of monoclinic, tetragonal, and cubic crystals. m can be calculated from the following formula (1) based on the peaks in the X-ray diffraction (XRD) pattern using CuKα radiation. The main crystal system may contribute to increasing the shrinkage temperature and shortening the firing time during firing of the zirconia calcined body.

[0063] In the calcined zirconia body, the peaks of the tetragonal and cubic crystals may not be substantially detected. That is, the monoclinic fraction f m can be set to 100%.

[0064]

number

[0065] In equation (1), I m (111) and I m (11-1) indicates the peak intensity of the (111) and (11-1) planes of the monoclinic system of zirconia, respectively. t (111) indicates the peak intensity of the (111) plane of the tetragonal crystal system of zirconia. c (111) indicates the peak intensity of the (111) plane of the cubic crystal system of zirconia.

[0066] The zirconia calcined body in the present invention preferably contains a stabilizer capable of suppressing the phase transition of zirconia. For example, it is preferable that a stabilizer capable of suppressing the phase transition of zirconia is contained in zirconia before calcination.

[0067] Examples of stabilizers capable of suppressing the phase transition of zirconia include oxides such as yttrium oxide (YO) (hereinafter referred to as "yttria"), calcium oxide (CaO), magnesium oxide (MgO), yttria, cerium oxide (CeO), scandium oxide (ScO), niobium oxide (NbO), lanthanum oxide (LaO), erbium oxide (ErO), samarium oxide (SmO), europium oxide (EuO), and thulium oxide (TmO), with yttria being preferred. These may be used alone or in combination. In a preferred embodiment, a coloring solution is provided in which the dental ceramic to be colored contains zirconia as a primary component and further contains yttria as a stabilizer, with the stabilizer being substantially yttria alone. In the preferred embodiment, the stabilizer being 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, relative to 100 mol% of the total of zirconia and stabilizers.

[0068] When the zirconia calcined body contains a stabilizer, the content of the stabilizer is preferably 0.1 to 18 mol%, more preferably 1 to 15 mol%, and even more preferably 1.5 to 10 mol%, based on 100 mol% of the total of zirconia and stabilizer. In a preferred embodiment, the dental ceramics and coloring solution for coloring the dental ceramics contain zirconia as a main component and the content of yttria is 1.5 to 10 mol%, based on the total moles of zirconia and yttria. In the preferred embodiment, the content of yttria is preferably 2.0 to 9.0 mol%, more preferably 2.5 to 8.5 mol%, and even more preferably 2.8 to 8.0 mol%.

[0069] The zirconia calcined body may optionally contain colorants (including pigments, composite pigments, and fluorescent agents), alumina (Al2O3), titanium oxide (TiO2), silica (SiO2), etc. These components may be used alone or in combination of two or more. Examples of the pigment include oxides of at least one element selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Zn, Y, Zr, Sn, Sb, Bi, Ce, Sm, Eu, Gd, and Er. Examples of the composite pigment include (Zr,V)O2, Fe(Fe,Cr)2O4, (Ni,Co,Fe)(Fe,Cr)2O4·ZrSiO4, and (Co,Zn)Al2O4. Examples of the fluorescent agent include Y2SiO5:Ce, Y2SiO5:Tb, (Y, Gd, Eu)BO3, Y2O3:Eu, YAG:Ce, ZnGa2O4:Zn, and BaMgAl 10 O 17 :Eu, etc.

[0070] A typical method for producing a zirconia calcined body is as follows. First, granules composed of a zirconia raw material containing a stabilizer (preferably zirconia particles whose primary crystal system is monoclinic) are prepared and press-molded into a shape such as a block or disk. Next, the molded body is subjected to cold isostatic pressing (CIP) as needed. The pressure during this process is, for example, 50 to 500 MPa. Next, the molded body is subjected to a calcination process. The calcination is performed by gradually increasing the temperature from room temperature to 800 to 1200°C and maintaining the temperature for approximately 1 to 6 hours to obtain a zirconia calcined body. The obtained zirconia calcined body is machined using conventionally known equipment depending on the final dental product. For example, if the dental product is a dental prosthesis, it is machined into a crown shape using CAD / CAM or the like.

[0071] The zirconia calcined body may be a commercially available product, such as "Noritake Katana (registered trademark) Zirconia" (model numbers: Disc UTML, Disc STML, Disc ML, Disc HT, and Disc LT) (all manufactured by Kuraray Noritake Dental Co., Ltd.).

[0072] The method for producing a colored zirconia calcined body according to the present invention includes a step of incorporating the coloring solution into the cut zirconia calcined body. Examples of methods for incorporating the coloring solution include applying the coloring solution to the zirconia calcined body using a brush, immersing the zirconia calcined body in a container containing the coloring solution, or spraying the coloring solution onto the zirconia calcined body using a sprayer. Conventional known tools and devices can be used. When a zirconia sintered body is produced directly from a green body without the calcination step, the coloring solution may be incorporated into the cut zirconia green body.

[0073] The present invention further encompasses a zirconia sintered body made from the colored zirconia calcined body. A method for producing 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. It is not particularly limited as long as the Er and Co components contained in the coloring solution develop color. However, it is preferably 1350°C or higher, more preferably 1450°C or higher, and even more preferably 1500°C or higher. The upper limit of the firing temperature is not particularly limited, but is preferably 1700°C or lower. The zirconia sintered body of the present invention includes not only sintered bodies obtained by sintering molded zirconia particles under normal pressure or without pressure, but also sintered bodies obtained by densifying the sintered body through high-temperature pressure treatment such as HIP (hot isostatic pressing).

[0074] The content of the stabilizer in the zirconia sintered body can be measured by, for example, inductively coupled plasma (ICP) emission spectroscopy, fluorescent X-ray analysis, or the like.

[0075] The zirconia sintered body preferably has at least one of partially stabilized zirconia and fully stabilized zirconia as a matrix phase. In the zirconia sintered body, the main crystalline phase of zirconia is at least one of a tetragonal system and a cubic system. The zirconia sintered body may contain both a tetragonal system and a cubic system. It is preferable that the zirconia sintered body is substantially free of a monoclinic system. Note that zirconia that is partially stabilized by adding a stabilizer is called partially stabilized zirconia (PSZ), and zirconia that is fully stabilized is called fully stabilized zirconia.

[0076] The present invention includes dental products made of the zirconia sintered body. Examples of the dental products include dental prostheses, orthodontic products, and dental implant products. Examples of the dental prostheses that can be used include zirconia inlays, onlays, laminate veneers, and crowns.

[0077] In any of the above embodiments, the type, content, etc. of each component can be changed as appropriate, and any component can be added, deleted, etc. Furthermore, in any of the above embodiments, the composition and property values of the coloring solution can be changed and combined as appropriate.

[0078] The present invention includes embodiments in which the above-described configurations are combined in various ways within the technical scope of the present invention, as long as the effects of the present invention are achieved. [Example]

[0079] 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.

[0080] [Examples 1 to 18 and Comparative Examples 1 to 2] The coloring solutions of the Examples and Comparative Examples were prepared as follows, and their properties were evaluated. The results are shown in Tables 1 and 2.

[0081] [Preparation of coloring solution] A colored solution was prepared by mixing the components shown in Tables 1 and 2 at room temperature in the amounts shown in the tables. The molar concentration of each metal component in the colored solution was measured by inductively coupled plasma (ICP) emission spectroscopy (SPS3500, manufactured by Hitachi High-Tech Science Corporation).

[0082] [Evaluation of handling of component V] When preparing the colored solution, the handleability and stability of component V were evaluated according to the following evaluation criteria. ○: No visible white smoke or discoloration occurs in the air at room temperature, and the product can be handled without any problems. △: White smoke is visible in the air at room temperature, and some care must be taken when handling. ×: White smoke, discoloration, obvious heat generation, etc. are visually observed in air at room temperature, making handling difficult.

[0083] [Production of zirconia calcined body] Next, the preparation of the zirconia calcined body to which the coloring solution is applied will be described.

[0084] First, a zirconia powder containing a stabilizer was prepared. 9.9 mass% (5.5 mol%) of yttria as a stabilizer was added to 90.1 mass% of zirconia powder whose primary crystal system was monoclinic to prepare a mixture. Next, this mixture was added to water to prepare a slurry, which was then wet-pulverized and mixed in a ball mill until the average particle size reached 0.13 μm or less. The pulverized slurry was dried using a spray dryer, and the resulting powder was fired at 950°C for 2 hours to prepare a powder (primary powder). The average particle size can be determined by a laser diffraction scattering method. Specifically, the laser diffraction scattering method can be performed using a laser diffraction particle size distribution analyzer (SALD-2300, manufactured by Shimadzu Corporation) on a volume basis, using a 0.2% aqueous solution of sodium hexametaphosphate as a dispersion medium.

[0085] Water was added to the obtained primary powder to prepare a slurry, which was then wet-pulverized and mixed in a ball mill until the average particle size was 0.13 μm or less. A binder was added to the pulverized slurry, which was then dried in a spray dryer to produce a powder (secondary powder). The produced secondary powder was used as a raw material powder to produce the zirconia calcined body described below.

[0086] Next, a method for producing 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 subjected to primary press molding using a uniaxial press molding machine at a surface pressure of 57.5 kN for 20 seconds. The obtained primary press molded body was fired at 1000°C for 2 hours to produce a zirconia calcined body.

[0087] [Measurement of color after firing] The prepared coloring solution was applied to the produced zirconia calcined body, and then fired under the firing conditions shown in Tables 1 and 2 to obtain a sintered body. The obtained sintered body was polished into a disk with a diameter of 15 mm and a thickness of 1.2 mm, and measured against a white background using a spectrophotometer manufactured by Olympus Corporation (product name "Crystal Eye CE100-DC / JP", light source: 7-band LED light source). * a * b * Color system (JIS Z 8781-4:2013 Color measurement-Part 4: CIE 1976 L * a * b * chromaticity is measured using the L1 color space. * , a1 * , b1 * The average values of the measured values are shown in Tables 1 and 2 (n=3).

[0088] [Measurement of biaxial bending strength after firing] The prepared coloring solution was applied to the produced zirconia calcined body, and then fired under the firing conditions shown in Tables 1 and 2 to obtain a sintered body having a diameter of 15 mm and a thickness of 1.2 mm. The biaxial bending strength of the obtained sintered body was measured (n=5) at a crosshead speed of 0.5 mm / min using a benchtop precision autograph testing machine (product name "AG-I 100kN") manufactured by Shimadzu Corporation in accordance with JIS T 6526:2012. The average values of the measured values are shown in Tables 1 and 2.

[0089] [Measurement of color after porcelain deposition and firing] The prepared coloring solution was applied to the prepared zirconia calcined body and fired under the firing conditions shown in Tables 1 and 2. Then, Cerabian (registered trademark) ZR External Stain E Glaze (manufactured by Kuraray Noritake Dental Co., Ltd.) was built up and fired under the firing conditions shown in Tables 1 and 2 to obtain a sintered body. The obtained sintered body was polished into a disk with a diameter of 15 mm and a thickness of 1.2 mm, and measured against a white background using a spectrophotometer manufactured by Olympus Corporation (product name "Crystal Eye CE100-DC / JP", light source: 7-band LED light source). * a * b * Color system (JIS Z 8781-4:2013 Color measurement-Part 4: CIE 1976 L * a * b * chromaticity in the L2 color space) * , a2 * , b2 * The average values of the measured values are shown in Tables 1 and 2 (n=3).

[0090] [Evaluation of color difference before and after porcelain firing] The L1 obtained by the above measurement * , a1 * , b1 * , L2 * , a2 * , b2 * The values of Δb are substituted into the following equations (2) and (3) to evaluate the fading. * , and ΔE, an index of discoloration * asked for. Δb * =b2 * -b1 * ·····(2) ΔE * ={(L2 * -L1 * ) 2 +(a2 * -a1 * ) 2 +(b2 * -b1 * ) 2} 1 / 2 ···(3)

[0091] As a result, in Comparative Examples 1 and 2 containing the Tb component, Δb * The value of Δb was negative, i.e., -3.0 or less, and the yellowish color faded after firing the porcelain, and discoloration was confirmed. * The absolute value of is less than 3 and close to 0, there is almost no fading, and ΔE * The value was also small, at 3.0 or less, so it was confirmed that there was almost no discoloration.

[0092] [Table 1]

[0093] [Table 2] [Industrial Applicability]

[0094] The coloring solution of the present invention can impart a desired yellowish color to dental ceramics without causing discoloration even when porcelain is built up and fired on dental ceramics colored with the coloring solution.Therefore, as the demand for ceramic crowns for which the dental ceramic coloring solution can be suitably used continues to increase and as individual aesthetic needs become more sophisticated, the frequency of use of dental ceramic coloring solutions is expected to increase, and the dental ceramic coloring solution of the present invention is useful.

Claims

1. A coloring component and a solvent are included, the coloring component includes a V component, A coloring solution for coloring dental ceramics, wherein the V component is an oxide vanadium compound.

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

3. 3. The coloring solution according to claim 1, wherein the V component has a valence of +IV and / or +V.

4. The coloring solution according to any one of claims 1 to 3, wherein the component V is a component derived from at least one selected from the group consisting of vanadyl oxalate, vanadyl nitrate, and vanadyl acetate.

5. 5. The coloring solution according to claim 1, wherein the content of the V component is 0.0100 to 45.0 mmol / L in terms of V ions.

6. Regarding the L*, a*, b* of dental ceramics after coloring and sintering according to the L*a*b* color system, a* is −20 to 20, 6. The coloring solution according to claim 1, wherein b* is from 5 to 60.

7. 7. The coloring solution according to claim 6, wherein L* is 60 to 95 in (L*, a*, b*) according to the L*a*b* color system.

8. The coloring solution according to any one of claims 1 to 7, wherein the solvent comprises water or / and an organic solvent.

9. The coloring solution according to claim 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 claims 1 to 9, wherein the coloring component contains a Ni component.

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

12. The coloring solution according to any one of claims 1 to 11, further comprising a Zr component.

13. The coloring solution according to any one of claims 1 to 12, wherein the coloring solution does not contain a Pr component and a Tb component.

14. The coloring solution according to any one of claims 1 to 13, wherein the dental ceramic contains zirconia as a main component.

15. Dental ceramics colored with the coloring solution described in any one of claims 1 to 14 and having a V component carried on the surface.

16. The dental ceramic according to claim 15, wherein the V component is an ion or a complex.

17. 17. The dental ceramic according to claim 15, wherein the dental ceramic contains zirconia as a main component.

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