JP6879540B2 - Composite layered structure utilizing the self-assembled layered structure of high temperature oxidized TiO2 - Google Patents

Description

The present invention relates to a composite layered structure having a layered structure _{made of TiO 2} formed on the Ti surface, exhibiting white aesthetics and having improved peel strength.

Dental devices made of resin, ceramics, metal, etc. are often used in dental prostheses for prosthesis of healthy tooth defects due to dental diseases such as dental caries and periodontal disease, and in orthodontics. Naturally, the main purpose of these is to restore or improve oral functions such as occlusion and speech, but in recent years it is also important to improve the user's aesthetic awareness, that is, to improve or restore the "appearance" related to aesthetics. To.

For example, the metal bond porcelain crown is an artificial crown used for the anterior teeth, which are particularly conspicuous. An excellent porcelain material is baked to prosthesis the defective part. The porcelain material is made by baking multiple layers with different transparency and color tone in order to match the color tone with the adjacent healthy teeth. That is, the metal bond porcelain crown is a composite material made of metal in the invisible part and made of ceramic with high aesthetics in the visible part, but peeling of the baking interface can be mentioned as a practical problem. There is also a resin muzzle loader that is coated with a resin, but like the metal bond porcelain crown mentioned above, the low durability of the resin is a problem in addition to the interfacial strength.

Due to the recent trend toward aesthetics, the all-ceramic crown, which is made of ceramics as the abutment tooth, has emerged in the artificial teeth mentioned above in the last few years. Further, the connecting crown (bridge) includes a composite material of a resin and an inorganic material such as a fiber core. Such non-metalization of artificial crowns is due to the development of excellent resins (resin materials) and inorganic-organic hybrid materials, but their mechanical properties and durability are still inferior to those of metals. Even dental devices other than artificial crowns such as crowns and inlays have to take advantage of the mechanical properties of metals, such as denture bases, implants, brackets and orthodontic arch wires, which are superior to other materials such as toughness, elasticity and strength. There are many members that cannot be obtained.
On the other hand, with the growing interest of patients in QOL, there is an increasing demand for not only safety and recovery of defective function but also recovery of appearance, that is, improvement of aesthetics of dental materials, which is comparable to metal. It is desired to introduce a material that has a lack of strength and toughness and that has a metallic color coated with white.

The present inventors have Ti-29Nb-13Ta-4.6Zr (Ti: Nb: Ta: Zr = 53.4: 29: 13: 4.6) and Ti-36Nb, which are β-type Ti alloys for Ti and living organisms. In -2Ta-3Zr-0.3O (Ti: Nb: Ta: Zr: O = 58.7: 36: 2: 3: 0.3) alloy, whitening of the metal surface by a white film formed by high temperature oxidation treatment. Has been successful. The manufacturing method has already been filed (see, for example, Patent Document 1).
These prior arts are mainly techniques for whitening Ti alloys such as Ti-29Nb-13Ta-4.6Zr alloy, and are expected to be used as dental materials. White oxide films such as Ti-29Nb-13Ta-4.6Zr and Ti-36Nb-2Ta-3Zr-0.3O are dense and have high adhesion to the Ti alloy of the substrate, and the adhesion strength is 70 MPa or more.

On the other hand, in so-called pure Ti such as industrial pure Ti, the metal surface is formed with an oxide film composed of _{rutile-type TiO 2 by high-temperature oxidation.} The rutile-type TiO ₂ has a lightness L * calculated by the L * a * b * color system of 70 to 85, which is about the same as or higher than the crown color of Japanese people. _{Rutile-type TiO 2,} which is a high-temperature phase of Ti oxide, has been conventionally used as a white pigment called "titanium white" as a paint or cosmetic ingredient. Moreover, since it has already been used as one of food additives, _{the safety of TiO 2} itself is high. Furthermore, the rutile-type TiO ₂ has the same level of safety as the highly biosafe substrate Ti-29Nb-13Ta-4.6Zr in the cytotoxicity test.

Japanese Unexamined Patent Publication No. 2013-147439

However, TiO ₂ is the most brittle oxide among Ti oxides. For example, even in the film peeling test, _{cohesive fracture occurs easily in the formed TiO 2} film, and the strength of the coating layer is insufficient. The peel strength of the white oxide film of Ti-29Nb-13Ta-4.6Zr and Ti-36Nb-2Ta-3Zr-0.3O is about 70 MPa at maximum. On the other hand, _{the peel strength of the TiO 2 white oxide film is at most about 2 to 3} MPa, which is only 1/10 of the film strength of a standard adhesive of 30 MPa.

_{Therefore, the TiO 2} oxide film formed on the Ti substrate has only low peel strength and cannot be used as it is as a dental material or the like.

An object of the present invention is to provide a composite layered structure having excellent whiteness and high peel strength based on a _{Ti substrate and a TIO 2 film having excellent biosafety.}

The composite layered structure according to the present invention includes a Ti substrate and
A gap other than the backbone of the TiO ₂ between the Ti substrate 2 layer TiO ₂ layer and the second layer of TiO ₂ skeleton and the two-layer TiO ₂ layer connecting the TiO ₂ layer of which is provided on the surface of A laminated body in which _two layers of SiO occupying are laminated, and
including.

According to the composite layered structure according to the present invention, it _{is based on a Ti substrate and a TIO 2} film having excellent biosafety, and has excellent whiteness and high peel strength.

FIG. 5 is a schematic cross-sectional view schematically showing a cross-sectional structure of the composite layered structure according to the first embodiment. It is a graph which shows the relationship between the film thickness of the laminated body which constitutes a composite layered structure, and the lightness L *. It is a bar graph which shows the L * value, a * value, b * value in the L * a * b * color system of the pie skin-like structure of a TiO _{2 film and the composite layered structure which concerns on Example 1. FIG.} The spectral reflectance of each wavelength of the composite layered structure according to Example 1, the composite layered structure in which Au colloid is contained _{in the SiO 2 layer in Example 2, and the pie-skin structure of the TiO 2 film are determined.} It is a graph which shows. It is a bar graph which shows the peeling strength of the _{composite layered structure and the pie skin-like structure of a TIO 2} film which concerns on Example 1. FIG. It is the schematic which shows the peeling state of the surface after the peeling test in the composite layered structure which concerns on Example 1. FIG. (A) is an SEM image showing a cross-sectional structure of the composite layered structure according to Example 1, and (b) is an SEM-EDS image showing a portion containing Ti in the same portion as (a) in white. Yes, (c) is an SEM-EDS image showing a portion containing Si in the same portion as in (a) in white. It is a figure which shows the O 1s spectrum by XPS about the dry silica gel body obtained in the manufacturing process of the TiO ₂ single-phase material, the composite layer structure of Example 1, and the composite layer structure, and the sample after the heat treatment of the silica gel body. .. It is an X-ray diffraction pattern of _two layers of TiO. It is an X-ray diffraction pattern of the silica gel dried body by low temperature drying. It is an X-ray diffraction pattern of the composite layered structure which concerns on Example 1 after heating at a high temperature. It is the schematic cross-sectional view which shows typically the cross-sectional structure of the pie-skin-like structure of _{a TIO 2} film formed on a Ti substrate. 6 is an SEM image showing a cross-sectional structure of a pie crust-like structure of _{a TIO 2} film formed on a Ti substrate. 11 is an SEM image showing connecting holes (vias) between void layers of the pie-skin-like structure of the TiO _{2 film of FIG. 11.} It is a graph which shows the relationship between the holding time at the time of high temperature oxidation of a Ti substrate, and the film thickness of a pie crust-like structure of a _{TIO 2 film.} It is a bar graph which shows the L * value, a * value, and b * value in the L * a * b * color system of _{the front surface and the back surface when the pie skin-like structure of the TIO 2} film is formed on the front and back surfaces of the Ti substrate. .. It is a schematic diagram which shows the peeling state of the surface after the peeling test about the pie skin-like structure of _{the TIO 2} film formed on the Ti substrate. It is a photograph which shows the surface of the high temperature oxide film which has the pie skin-like structure of _{the TIO 2} film formed on the Ti substrate in the high temperature oxidation process in the middle of Example 3. FIG. 6 is a photograph showing the surface of an Au-containing composite layered structure in which the oxide film of FIG. 16 is impregnated with an aqueous solution of chloroauric acid 10 times and then vacuum impregnated _{to composite a SiO 2 gel. The surface of the high-temperature oxide film having the pie-skin-like structure of the TiO 2} film of FIG. 16 is impregnated with an aqueous solution of chloroauric acid once or 10 times (n = 10), and then vacuum impregnated to perform SiO ₂ It is a graph which shows the spectrophotometric result about the surface of the Au-containing composite layered structure in which a gel is composited. It is a graph which shows the Au 4f spectrum by XPS about the outermost surface of the Au-added TiO ₂ / SiO _{2 composite layered structure (n = 10).} It is a graph which shows the Au 4f spectrum by XPS about the coating surface which removed the surface layer by polishing about the Au-added TiO ₂ / SiO _{2 composite layered structure (n = 10).} It is a photograph of the surface of the composite layered structure containing Ag according to Example 4. It is a graph which shows the Ag 3d spectrum by XPS of the surface of _{the TiO 2} / SiO ₂ composite layer structure containing Ag when the Ag concentration is 0.04 mol%. It is a graph which shows the Ag 3d spectrum by XPS of the surface of _{the TiO 2} / SiO ₂ composite layered structure containing Ag when the Ag concentration is 0.4 mol%. It is a photograph which shows the state of the surface of the agar medium when the sample is a titanium plate (CP Ti). It is a photograph which shows the state of the surface of the agar medium when the sample is the TiO ₂ / SiO _{2 composite layered structure of Example 1.} It is a photograph which shows the state of the surface of the agar medium when the sample is the Ag-containing TiO ₂ / SiO _{2 composite layer structure of Example 4.}

(Progress leading to the invention)
_{A rutile-structured TiO 2} film is formed on the Ti substrate by anodizing. This dio ₂ coating is known to have a column structure with nanoporous, and due to _{the high biosafety and photocatalytic function of the TiO 2} phase, research on the use of photocatalysts and research aimed at application to medical materials have been reported. Has been done. Originally, TiO ₂ is used as a white pigment under the name of "titanium white", is also a component of cosmetics, and is a safe material for the human body, which is also designated as a food additive. In addition, it has high visible light reflection characteristics and ultraviolet wavelength absorption, and the rutile structure has excellent properties such as exhibiting a photocatalytic function as well as the anatase structure.

The present inventor has conducted research to impart white aesthetics to a metal by adhering a Ti oxide to the surface of a Ti substrate. Specifically, when the Ti substrate is heat-treated at a temperature of about 850 ° C. or higher in the presence of oxygen, rutile-type TiO ₂ grows on the surface in the same manner as anodization. In the previous studies, by thickening the high-temperature oxide film on the Ti substrate to a thickness of several tens of μm, as shown in FIG. 10, two TiO layers and a void layer at _{intervals of 2 to 3 μm were laminated by self-assembly.} It has been found to form a pie crust-like structure. Since this TiO ₂ oxide film exhibits a brightness (white) close to the crown color of Japanese maxillary central incisors, we are trying to use it for the surface coating layer of Ti dental materials.

However, as shown in FIG. 10, this TiO ₂ film forms a pie crust-like structure 7 _{consisting of TiO 2 layers 2 and void layers 3 at intervals of 0.5 to 3 μm by self-assembly.} TiO ₂ is the most brittle oxide among Ti oxides. Further, since the pie crust-like structure 7 has the void layer 3, cohesive fracture in the film easily occurs even in the film peeling test, and the strength of the coating layer is insufficient. The peel strength of this TiO _{2 white oxide film is about 2 to 3} MPa, which is only 1/10 of the film strength of a standard adhesive (about 20 to 30 MPa). In this case, the peeling occurs mainly in the fragile void layer 3 in the pie crust-like structure 7. Therefore, _{the peeling of the TiO 2} oxide film mainly occurs in the void layer 3, and the conventional technique _{has a problem that the TiO 2} white oxide film is easily peeled off and the peeling strength is remarkably poor.

The present inventor has attempted to hybridize (composite) _{SiO 2 in} the void layer of the pie crust-like structure of the _{TiO 2} film by the sol-gel method under vacuum. By hybridization, silica sol enters the void layer of the pie crust-like structure of the _{TiO 2 membrane.} Then, it was dried and made into silica gel, and heated at a high temperature to crystallize. As a result, a new finding has been obtained that the peeling strength of the entire pie-skin-like structure of _{the TiO 2 film is remarkably improved, and the white oxide film made of the TiO 2- SiO 2} composite layered structure is less likely to be peeled from the Ti substrate. Furthermore, it has been found that when the void layer is filled with _{SiO 2 , the brightness (whiteness) of the TiO 2} film is maintained or slightly increased.
The above has led to the present invention.

The composite layered structure according to the first aspect includes a Ti substrate and
A gap other than the backbone of the TiO ₂ between the Ti substrate 2 layer TiO ₂ layer and the second layer of TiO ₂ skeleton and the two-layer TiO ₂ layer connecting the TiO ₂ layer of which is provided on the surface of A laminated body in which _two layers of SiO occupying are laminated, and
including.

According to the above configuration, it _{is based on a Ti substrate and a TIO 2} film having excellent biosafety, and has excellent whiteness and high peel strength.

In the composite layered structure according to the second aspect, in the first aspect, _{the thickness of the dio 2} layer of the laminated body may be in the range of 0.5 μm to 5 μm.

In the composite layered structure according to the third aspect, in the first or second aspect, _{the thickness of the SiO 2} layer of the laminated body may be in the range of 0.2 μm to 5 μm.

The composite layered structures according to the fourth aspect, in the third one of embodiments from the first, the laminate, the two-layer TiO ₂ layer and said TiO ₂ skeleton and the SiO ₂ layer is It may be laminated over a plurality of sets.

In any of the first to fourth aspects of the composite layered structure according to the fifth aspect, the thickness of the laminated body may be 10 μm or more.

In any of the first to fifth aspects of the composite layered structure according to the sixth aspect, the lightness L * value in the L * a * b * color system may be 70 or more.

In the composite layered structure according to the seventh aspect, in any one of the first to sixth aspects, the SiO ₂ layer of the laminated body may contain Au colloid or Ag ions.

Manufacturing method of the eighth composite layered structure according to the aspect, by heating at a temperature above 800 ° C. The Ti substrate in an oxidizing atmosphere, on the Ti substrate, the TiO ₂ layer of 2-layer the second layer TiO a thermal oxidation treatment step and the gap layer other than the backbone of the TiO ₂ between the TiO ₂ backbone wherein 2-layer TiO ₂ layer to form a stacked pie skin-like structure that connects the _two layers,
The Si-containing alkoxide of the silica precursor is hydrolyzed and polycondensed by the vacuum-impregnated sol-gel method, and the obtained silica sol is impregnated into the void layer of the pie crust-like structure, and at least a part of the silica sol. Vacuum impregnation process and
A drying step of drying the silica gel and
A heating step of heating the silica gel at a temperature equal to or higher than the crystallization temperature to crystallize the silica gel.
including.

_{According to the above configuration, the void layer of the pie crust-like structure of the TiO 2} film is vacuum-impregnated with silica sol by the vacuum-impregnated sol-gel method, dried to silica gel, and heated to crystallize silica gel. As a result, the _{SiO 2} layer can be formed and reinforced in the void layer of the pie crust-like structure of the _{TiO 2} film, and a film having a peel strength four times or more that of the _{TiO 2 single-phase material can be obtained.} it can.

The method for producing a composite layered structure according to a ninth aspect is, in the eighth aspect, gold impregnation in which the pie crust structure is vacuum impregnated with an Au colloidal solution or a gold chloride aqueous solution before the vacuum impregnation step. The process may be included.

In the method for producing a composite layered structure according to a tenth aspect, silver nitrate may be added to the silica precursor in the vacuum impregnation step in the eighth or ninth aspect.

Hereinafter, the composite layered structure and the method for manufacturing the composite layered structure according to the embodiment will be described with reference to the accompanying drawings. In the drawings, substantially the same members are designated by the same reference numerals.

(Embodiment 1)
<Composite layered structure>
FIG. 1 is a schematic cross-sectional view schematically showing a cross-sectional structure of the composite layered structure according to the first embodiment. The composite layered structure 10 includes a Ti substrate 1, _{a skeleton 6 of the TiO 2 that connects the two layers of TIM 2} layer 2 provided on the surface of the Ti substrate 1, and two layers of thio ₂ layer 2, and two layers of thio. Includes a laminate 8 in which a _{SiO 2} layer 4 occupying a gap other than the skeleton 6 of the TiO _{2 between the two layers 2 is laminated.} In the composite layered structure 10, SiO the space layers 3 between which Ti substrate 1 on the high temperature oxidation reaction formed two layers TiO ₂ layer of the TiO ₂ film pie skin-like structure 7 2 shown in FIG. 10 _{It is characterized in that the two} layers 4 are filled and reinforced. In this laminated body 8, _{unlike a superlattice structure in which TiO 2} layers and SiO ₂ layers are simply alternately laminated, the SiO ₂ layer 4 exists together with the skeleton 6 of _{TiO 2.} Further, in the laminated body 8, the two layers of the TiO ₂ layer 2 and the skeleton 6 of the _{TiO 2 and the SiO 2} layer 4 may be laminated in a plurality of sets. _{In this case, a plurality of SiO 2} layers are connected to each other in a direction perpendicular to the layer of the laminated body 8. As a result, in the laminated body 8 of the composite layered structure 10, the peel strength is four times or more, preferably 10 times or more, as compared with the pie-skin-like structure 7 of _{the original TiO 2 film, as shown in Example 1 described later.} It has been greatly improved by more than double. Further, the hardness of the laminated body 8 of the composite layered structure 10 is also improved.
The SiO ₂ layer is not limited to the case where it is crystallized, and may include a non-crystal (amorphous) portion.

FIG. 2 is a graph showing the relationship between the film thickness of the laminated body 8 constituting the composite layered structure 10 and the brightness L *.
As shown in FIG. 2, it can be seen that the thickness of the laminated body 8 is about 10 μm or more and the brightness L * is 70 or more. The brightness L * shows about 80 until the thickness of the laminated body 8 reaches 100 μm. Since the brightness L * is 70 or more, the metallic color of the substrate can be coated and the surface color can be changed from gray to white.

The components constituting the composite layered structure 10 will be described below.

<Ti board>
The Ti substrate 1 may be a Ti substrate having a purity of 98% or more. Further, it may be made of pure industrial Ti. For example, it may be Commercially Pure (CP) Ti Grade 2. A Ti substrate made of any of JIS standard (JIS H4650) 1 type, 2 types, 3 types, and 4 types of pure Ti may be used.

<Tio ₂ layer>
The TiO ₂ layer 2 is formed on the surface of the Ti substrate 1 by heating the Ti substrate 1 at a temperature of 800 ° C. or higher in an oxidizing atmosphere. Industrially, it is preferable to heat in the temperature range of 800 ° C. to 1200 ° C. The heating time may be, for example, 10 minutes or more. In consideration of efficiency and the like, it is industrially preferable to heat in a time range of 24 hours or less. That is, the TiO ₂ layer 2 constitutes the pie-skin-like structure 7 of the _{TiO 2} film formed on the Ti substrate 1 by the above-mentioned high-temperature oxidation treatment (FIG. 10). _{The TIO 2} coating self-assembled on the Ti substrate by heat treatment _{can control the thickness of the TIO 2} layer and the thickness of the void layer depending on the heat treatment conditions. The thickness of the TiO ₂ layer 2 is preferably in the range of 0.1 μm to 5 μm, more preferably in the range of 0.5 μm to 5 μm. _{The TiO 2} layer having a thickness of less than 0.1 μm is difficult to be laminated in multiple layers, and sufficient whiteness cannot be obtained. On the other hand, when the thickness of one layer exceeds 5 μm and the thickness is increased, the number of connecting holes (vias) in the _{TiO 2 layer connecting the upper and lower void layers that serve as the entry path of the sol decreases due to the increase in crystal grains. Therefore, the filling of SiO 2 in} the void layer by the vacuum impregnated sol-gel method becomes insufficient, sufficient strength cannot be obtained by hybridization, and the peel strength decreases.
Further, in _{the pie-skin-like structure 7 of the TiO 2} film, as shown in FIG. 10, the TiO ₂ layer 2 is separated by the void layer 3. On the other hand, in the composite layered structure 10, as shown in FIG. 1, the TiO ₂ layer 2 is separated from each other via the _{SiO 2 layer 4.} Each TiO ₂ layer 2 is connected by a skeleton 6 of _{TiO 2.}

<SiO ₂ layer>
The SiO _{2 layer 4 is formed by silica gel (SiO 2} gel) of a Si-containing organic compound filled in the void layer 3 of the pie crust-like structure 7 of _{the TIO 2} film formed on the Ti substrate 1 by a vacuum impregnation method. It is then formed by crystallization. The SiO ₂ layer 4 is not limited to the crystallized one, and may include a non-crystal (amorphous) portion. _{The thickness of the two} layers of SiO is determined by the spacing between the void layers. As described above, the gap spacing can be controlled by the heat treatment conditions at the time of forming the _{TiO 2 film.} The thickness of the SiO ₂ layer 4 may be in the range of 0.2 μm to 5 μm. If _{the thickness of the SiO 2} layer is too thin, the _{reinforcing effect due to the hybridization (composite) of the SiO 2} layer cannot be obtained, and if it is too thick, the strength of the _{TiO 2 self-assembled monolayer itself which is the skeleton of the composite layered structure itself.} Decreases. Further, each SiO ₂ layer 4 is connected by a via (connecting hole) 5.

<About additives>
The color tone of the oxide film is determined by the color of the oxide itself and the thickness of the film. The TiO ₂ oxide film has a high lightness L * and a slight yellowish color + b * as described later. Therefore, the lightness (L *) and the yellowness (+ b *) can be increased by thickening the coating film. On the other hand, the oxide color itself has almost no redness (+ a *), and the redness cannot be controlled by thickening. In order to get closer to the crown color, it is necessary to make the color of the coating reddish by some method. For example, as shown in Example 2 described later, in the TiO ₂ / SiO ₂ composite layered structure, the addition of a dye such as a metal complex to the _{SiO 2} layer gives a reddish tint that was not possible with the _{TiO 2 single phase.} be able to. By increasing the variety of color tones, it is possible to meet the demand for high aesthetics as a dental material. Furthermore, it can be expected to add value by improving functionality, such as preventing caries by adding fluorine ions to the _{SiO 2 layer and imparting antibacterial properties by adding silver ions.}

<Manufacturing method of composite layered structure>
A method for manufacturing the composite layered structure according to the first embodiment will be described.
(1) First, a Ti substrate is prepared. Specifically, for example, an industrial Ti substrate is prepared. The surface may be polished to make the surface texture uniform. Further, after ultrasonic cleaning or the like, the test piece may be dried to eliminate contamination on the surface of the test piece.
(2) Next, the Ti substrate is heated at a temperature of 800 ° C. or higher in an oxidizing atmosphere. Industrially, the temperature range of 800 ° C. to 1200 ° C. is preferable. Further, the heating time may be, for example, 10 minutes or more. In consideration of efficiency and the like, it is industrially preferable to heat in a time range of 24 hours or less. The oxidizing atmosphere may be an oxygen-containing atmosphere, for example, the atmosphere. Further, specifically, for example, a heat treatment furnace may be used to heat and hold the Ti substrate in the atmosphere and then cool the furnace. This enables forming a pie-skin-like structure of the TiO ₂ film and the TiO ₂ layer and the gap layer is stacked on Ti substrate.
(3) Next, the silica precursor itself or the silica sol obtained by hydrolysis and polycondensation from the silica precursor by the vacuum impregnation sol-gel method is vacuum impregnated in the void layer in the pie crust-like structure _{of the TiO 2 film.} In the vacuum impregnated sol-gel method, for example, the absolute pressure may be 200 hPa or less. For example, TEOS may be used as the silica precursor and HCl may be used as the acid catalyst. In addition, polycondensation may further proceed during vacuum impregnation, and a part of the silica sol may be changed to silica gel. Alternatively, the entire silica gel may be converted to silica gel.
(4) After that, a drying step may be performed if necessary. For example, the silica gel obtained by vacuum-impregnating the void layer by low-temperature drying at 40 ° C. to 100 ° C. can be used as silica gel. The above temperature range is an example, and drying may be performed at a lower temperature. Moreover, the dry atmosphere may be a vacuum atmosphere. Even when the change from silica gel to silica gel is completed at the time of the vacuum impregnation, the silica gel can be dried by the drying step. By this drying step, for example, solvents, by-products and the like can be removed.
(5) Next, if necessary, the heating step may be performed at a temperature equal to or higher than the crystallization temperature (573 ° C.) of _{silicon dioxide (SiO 2).} Silica gel can be crystallized by this heating.
Of the above steps, the (4) drying step and / or (5) heating step is not an essential step and may be performed arbitrarily.
The process described above, Ti and the substrate 1, TiO between on the formed the TiO ₂ layer 2 as a skeleton 6 of TiO ₂ that connects the TiO ₂ layer 2 of upper and lower layers upper and lower layers TiO ₂ layer 2 to the It is possible to obtain a composite layered structure 10 including a laminated body 8 in which a _{SiO 2} layer 4 occupying a gap other than the skeleton of _{2 is laminated.}

(Tio ₂ membrane pie crust structure)
FIG. 10 is a schematic cross-sectional view schematically showing a cross-sectional structure of a pie-skin-like structure 7 of _{a TIO 2} film formed on a Ti substrate 1. FIG. 11 is an SEM image showing the cross-sectional structure of the pie-skin-like structure 7 of _{the TIO 2} film formed on the Ti substrate 1. FIG. 12 is an SEM image showing connecting holes (vias) between the void layers of the pie crust-like structure 7 of _{the TiO 2 film of FIG.} FIG. 13 is a graph showing the relationship between the retention time of the Ti substrate during high-temperature oxidation and the film thickness of the pie-skin-like structure of the _{TIO 2 film.}
By thickening the high-temperature oxide film on the Ti substrate 1 to a thickness of several tens of μm, a pie crust-like structure 7 is formed _{by the TIO 2 layer 2 and the void layer 3 at intervals of 0.5 to 3 μm by self-organization.} Further, the TiO ₂ oxide film exhibits luminosity (white) near the crown color. The pie-skin-like structure 7 of the _{TiO 2 film is formed by laminating the TiO 2} layer 2 and the void layer 3 between the upper and lower two TiO _{2 layers.} Further, TiO ₂ layers of upper and lower layers are connected with TiO ₂ skeletal 6. Further, as shown in FIG. 12, the TiO ₂ layer 2 is composed of crystals having a diameter of several μm, and each TiO ₂ layer 2 is connected to the void layers 3 above and below the dio 2 layer 2 with a diameter of about several hundred nm. There are many holes (vias) 5. That is, each void layer 3 is connected by a via 5. In the schematic cross-sectional view of FIG. 10, the TiO ₂ layer 2 is shown as having substantially the same thickness in the direction perpendicular to the surface. On the other hand, as shown in FIG. 11, since the oxidation reaction actually proceeds from the surface of the Ti substrate 1 toward the inside, the TiO _{2 layer 2 on the surface side is relatively thick, and the TiO 2} layer in the deep part close to the Ti substrate is used. 2 becomes relatively thin. Further, as shown in FIG. 13, the film thickness of the pie crust-like structure of the _{TiO 2} film becomes thicker as the holding time during high-temperature oxidation becomes longer. The rate of increase in film thickness gradually slows down, but it can be seen that the thickness reaches 200 μm in about 180 minutes.

FIG. 14 shows the L * value, a * value, and b * value in the L * a * b * color system of _{the front surface and the back surface when the pie-skin-like structure of the TIO 2} film is formed on the front and back surfaces of the Ti substrate. It is a bar graph which shows.
As shown in FIG. 14, _{the pie-skin-like structure of the TiO 2} film on the front and back surfaces has a high lightness L * value of around 80. On the other hand, since the a * value indicating red-green is almost zero and the b * value indicating blue-yellow is around 8, it looks slightly yellowish white to the naked eye.

FIG. 15 is a schematic view showing a peeled state of the surface 12 of the pie-skin-like structure of _{the TiO 2} film formed on the Ti substrate after the peeling test.
As shown in FIG. 15, the surface 12 after the peeling test is white. That is, since the peeling occurs mainly in the void layer 3 of the pie-skin-like structure 7 of the _{TiO 2} film, it can be seen that the white oxide film _{of the TiO 2 layer 2 remains on the peeling surface 12.}

(Vacuum impregnated sol-gel method)
In the vacuum impregnated sol-gel method, in terms of the sol-gel method, for example, a Si-containing alkoxide (silica precursor) such as TEOS (tetraethyl orthosilicate) is used. Further, a hydrolysis / polycondensation reaction is carried out under acidic or basic conditions to desorb alcohol _{to synthesize silica sol (SiO 2} (silica, silicon dioxide)). On the other hand, in terms of vacuum impregnation, the void layer of the pie crust-like structure of the _{TiO 2} film is vacuum impregnated with a Si-containing alkoxide which is a silica precursor or a silica sol after hydrolysis thereof. Vacuum impregnation may be performed by reducing the pressure in the atmosphere. The absolute pressure of the atmosphere may be, for example, 200 hPa or less. Further, a low vacuum atmosphere may be used. In addition, during vacuum impregnation, partial polycondensation may proceed further and a part of the silica sol may be changed to silica gel. Alternatively, the entire silica gel may be converted to silica gel.

(Silica precursor)
_{As the silica precursor for forming the SiO 2} layer (silica) by the sol-gel method, for example, a Si-containing alkoxide such as TEOS can be used. The silica precursor may be any as long as it produces silica by the sol-gel method, and is not limited to the Si-containing alkoxide.

(catalyst)
The catalyst in the sol-gel method may be either an acidic catalyst or a basic catalyst. As the acidic catalyst, for example, hydrochloric acid (HCl), nitric acid, sulfuric acid, acetic acid and the like can be used. As the basic catalyst, for example, ammonia (NH ₃ ), ethylamine, pyridine and the like can be used.
Hydrochloric acid (HCl) is preferable as the catalyst used for vacuum impregnating the void layer having a pie crust-like structure of _two layers of TiO. Since the sol-gel reaction proceeds relatively slowly by using hydrochloric acid as a catalyst, it is considered that the sol-gel reaction _{of SiO 2 can proceed after the void layer is impregnated.}

(Example 1)
(1) First, Commercially Pure Ti and Grade 2 (hereinafter referred to as "CP Ti") were cut to a thickness of 1 mm with a fine cutter. Then, it was polished to # 4000 using emery paper to make the surface texture uniform. In addition, the test piece was ultrasonically cleaned in acetone and dried to eliminate contamination of the test piece surface with deposits. The Ti substrate was prepared by the above.
(2) Next, using a heat treatment furnace, the Ti substrate was held in the air at 1000 ° C. (1273 K) for 30 minutes (1.8 ks) and then cooled in the furnace. Thus, to form a pie-skin-like structure 7 of the TiO ₂ film and the TiO ₂ layer 2 and the gap layer 3 is laminated on the Ti substrate 1 as shown in FIG. 10.
(3) Next, the silica sol obtained by hydrolysis from the silica precursor by the vacuum-impregnated sol-gel method was vacuum-impregnated in the void layer in the pie crust-like structure _{of the TiO 2 film.} In the vacuum impregnated sol-gel method, for example, TEOS was used as the silica precursor and HCl was used as the acid catalyst. Specifically, pure water (10 g), ethanol (10 g), and HCl as an acid catalyst are added to TEOS (42 g), and silica sol is added to the void layer in the pie crust-like structure _{of the TiO 2 film in a vacuum while stirring.} Vacuum impregnated.
(4) Then, low temperature drying was performed at 60 ° C. (333K) for about overnight. As a result, the silica sol vacuum-impregnated in the void layer was made into silica gel.
(5) Next, high-temperature heating was performed at 600 ° C. for 100 minutes (6.0 ks). As a result, residual water and organic substances were removed.
Through the above steps, the composite layered structure of Example 1 was obtained.

(Example 2)
In Example 2, a composite layered structure was obtained in the same manner as in Example 1 except that the silica precursor contained Au colloid in the vacuum impregnated sol-gel method.

(Measurement of oxide film color with a spectrophotometer)
In order to quantitatively evaluate the color tone, the color of the surface oxide film was measured using a spectrophotometer and quantified by the L * a * b * color system. Here, L * corresponds to the lightness, a * corresponds to the hue of red-green, and b * corresponds to the hue of yellow-blue. As the colorimeter, CM-5 manufactured by Konica Minolta was used.

FIG. 3 is a bar graph showing the L * value, a * value, and b * value in the L * a * b * color system of the pie-skin-like structure _{of the TiO 2 film and the composite layered structure according to Example 1.} ..
As shown in FIG. 3, the composite layered structure according to the first embodiment has a high brightness L * value of about 80. On the other hand, since the a * value indicating red-green is almost zero and the b * value indicating blue-yellow is around 8, it looks slightly yellowish white to the naked eye. This shows that it is useful as a surface coating layer for Ti dental materials.
Further, in the composite layered structure according to Example 1, the lightness L *, which indicates whiteness, tends to increase slightly due to hybridization as compared with the pie-skin-like structure _{of the TiO 2 film, but at least has a negative effect.} Does not reach. It can be seen that the a * value and the b * value hardly change, and the reflectance is almost the same at each wavelength. Therefore, it is possible to improve the peel strength of the film without significantly changing the original color tone of the _{TiO 2 film.}

FIG. 4 shows the wavelengths of the composite layered structure according to Example 1, the composite layered structure in which the SiO ₂ layer in Example 2 contains Au colloid, and the pie skin-like structure of the _{TiO 2 film.} It is a graph which shows the spectral reflectance.
As shown in FIG. 4, _{by introducing the SiO 2} layer into the void layer of the pie crust-like structure of the _{TiO 2} film, the reflectance is increased in the near-ultraviolet region, and the reflectance in the visible light region is slightly increased. It increases or is almost the same as in the case of the pie crust-like structure of the _{TiO 2 film.} As shown in Example 2, _{when Au colloid is contained in the SiO 2} layer, the rise of the reflectance from λ = 400 nm starts from the lower wavelength side, and the reflectance increases over all wavelengths. did. That is, in this composite layered structure, it is possible to impart functionality such as coloring by adding a pigment to the silica sol, prevention of dental caries by adding fluorine ions, and imparting antibacterial properties by adding silver ions.

(Measurement of peel strength by adhesion test)
For adhesion measurement, the adhesion tester Quad Group Inc. ROMULUS (trade name) manufactured by the same manufacturer was used. The surface of the oxide film and the stud pin having an upper shape of φ2.7 mm were fixed with an epoxy adhesive (held at 150 ° C. (423K) for 60 minutes (3.6ks)). Then, the test piece was placed on the cylindrical support, and a load (10.5 kgf / s) was applied to the stud pin in the vertical downward direction. Then, the load when the oxide film was peeled off was divided by the adhesive area to calculate the oxide film adhesion strength.

FIG. 5 is a bar graph showing the peel strength of the _{composite layered structure and the pie crust-like structure of the TiO 2 film according to Example 1.} FIG. 6 is a schematic view showing a peeling state of the surface of the composite layered structure according to Example 1 after the peeling test.
As shown in FIG. 5, the peel strength of the composite layered structure according to Example 1 increased to about 15 times that of the pie crust-like structure of the _{TiO 2 film.} Further, as shown in FIG. 6, the peeling surface 11 after the peeling test has a metallic color instead of white. That is, _{it was confirmed that the TiO 2} layer and the SiO ₂ layer were not peeled off in the laminated body but at the interface between the laminated body and the Ti substrate. Furthermore, the hardness of the composite layered structure _{increased from Hv = 604 of the TiO 2} single phase to Hv = 658 by hybridization.

(Cross section observation and element mapping)
FIG. 7A is an SEM image showing a cross-sectional structure of the composite layered structure according to the first embodiment. FIG. 7B is an SEM-EDS image showing in white a portion containing Ti in the same portion as in FIG. 7A. FIG. 7 (c) is an SEM-EDS image showing a portion containing Si in the same portion as in FIG. 7 (a) in white.
In the SEM image of FIG. 7A, the direction perpendicular to the surface of the Ti substrate is tilted by 90 ° and shown horizontally. That is, it shows a state in which the _{TiO 2} layer and the SiO ₂ layer are laminated from the left side to the right side of the paper surface. In FIG. 7A, it can be seen that _{the TiO 2} layer is thick and the SiO _{2 layer is thinly laminated.} In the SEM-EDS image of FIG. 7 (b), the portion containing Ti is shown in white, and it can be seen that it corresponds to FIG. 7 (a). In the SEM-EDS image of FIG. 7 (c), the portion containing Si is shown in white, and it was confirmed from the element mapping _{that the SiO 2} layer was introduced into the void layer between the _{TiO 2 layers.}

(State of dried silica gel)
When the composite layered structure is produced by the vacuum impregnated sol-gel method, the silica gel dried product obtained at the same time has high gel transparency at that time. Further, comparing the optical microscope image of the dried silica gel obtained by the conventional method with the dried silica gel used when producing this composite layered structure, the dried silica gel obtained by the vacuum impregnated sol-gel method is the conventional method. There are fewer voids than the dry silica gel obtained in. Therefore, it is considered that silica gel having few defects such as voids is similarly _{introduced between the TiO 2 layers.} That is, it is considered that the initial defects were few even after the crystallization of the _{SiO 2} layer, and the peel strength of the composite layered structure was improved as compared with the _{TiO 2 single-phase material.}

(Surface analysis by X-ray photoelectron spectroscopy (XPS))
FIG. 8 shows the _{O 1s spectra of the TiO 2} single-phase material, the composite layered structure of Example 1, the dried silica gel body obtained in the process of producing the composite layered structure, and the sample after the heat treatment of the silica gel body by XPS. It is a figure which shows. The double peaks of the TiO ₂ single-phase material are all caused by _{TiO 2.}
As shown in FIG. 8, it can be seen that in the composite layered structure of Example 1, the product obtained by the vacuum impregnated sol-gel method is SiO _2.

(Evaluation of the crystallinity of _{SiO 2} by X-ray diffraction (radioactive source: Cu))
FIG. 9A is an X-ray diffraction pattern of _{two layers of TiO.} FIG. 9B is an X-ray diffraction pattern of the dried silica gel body by low temperature drying. FIG. 9C is an X-ray diffraction pattern of the composite layered structure according to Example 1 after heating at a high temperature.
As shown in FIG. 9A, the TiO ₂ single-phase material has a peak (indicated by “R” and a plane index) of the spectrum showing _{TiO 2 having a rutile structure.} As shown in FIG. 9B, a broad peak indicating low crystallinity was obtained in the dry silica gel body. On the other hand, as shown in FIG. 9C, the composite layered structure according to the first embodiment corresponds to _{the sharp peak of the TiO 2} layer (shown with “R” and the plane index) and the crystal of the _{SiO 2 layer.} Possible peaks (shown with "S" and surface index: (110) S and (01-2) S) appear, respectively, and a partially crystallized SiO ₂ layer is formed by heating at 600 ° C. It was confirmed that it was done.

(Embodiment 2)
The method for producing the composite layered structure according to the second embodiment is compared with the method for producing the composite layered structure according to the first embodiment, and the pie-skin-like structure of the _{TiO 2 film is before the vacuum impregnation step of silica gel.} Is different in that it includes a gold impregnation step of vacuum impregnating an Au colloidal solution or a gold chloride aqueous solution. Since the other steps are substantially the same as those in the first embodiment, the description thereof will be omitted.
The color tone of the TiO ₂ / SiO ₂ composite layered structure is determined by the color of the oxide itself and the thickness of the coating film. In this case, the lightness (L *) and yellowness (+ b *) can be increased by thickening the coating film, but the oxide color itself has almost no redness (+ a *) and cannot be controlled by thickening. .. In order to get closer to the crown color, it was necessary to make the color of the coating reddish by some method. The present inventor added an additive that increases the reflectance on the long wavelength side (λ = 620 nm to 750 nm), which causes red to develop even in the visible light wavelength range, to the _{SiO 2} gel in the process of producing the composite film, thereby causing a reddish component. I thought that it would be possible to add. In addition, by using the same technology, it is possible to have functionality such as sustained release drug and antibacterial property.
In the second embodiment, since the gold impregnation step is included as described above, it is impossible to use _{the TiO 2} / SiO ₂ multilayer structure as a starting material and add a dye such as a metal complex to the _{SiO 2 layer with a single phase of TiO 2.} It is also possible to give it a reddish tint. In addition, by increasing the variation of color tone, it becomes possible to meet the demand for high aesthetics as a dental material. Furthermore, it can be expected to add value by improving functionality, such as preventing caries by adding fluorine ions to the _{SiO 2 layer and imparting antibacterial properties by adding silver ions.}

(Example 3)
Example 3 relates to an Au-containing TiO ₂ / SiO ₂ composite layered structure having a reddish tint and a method for producing the same.

(Film preparation)
(1) First, a TiO ₂ coating having a pie crust-like structure is prepared. In the preparation of this film, the high temperature oxidation process and the vacuum impregnation process are substantially the same as in Example 1. Commercially Pure Titanium, Grade 2 (hereinafter referred to as "CP Ti") was cut to a thickness of 1 mm with a fine cutter. Then, in order to make the surface texture uniform, it was polished to # 4000 using emery paper. In addition, the test piece was ultrasonically cleaned and dried in acetone to eliminate contamination of the test piece surface with deposits. The Ti substrate was prepared by the above.
(2) Next, using a heat treatment furnace, the Ti substrate was held in the air at 1000 ° C. (1273 K) for 30 minutes (1.8 ks), then cooled in the furnace, and surface oxidation treatment was performed. Thus, to form a pie-skin-like structure of the TiO ₂ film and the TiO ₂ layer 2 and the gap layer 3 is laminated on the Ti substrate 1. 16, in the middle of the high-temperature oxidation process of Example 3 is a photograph showing a surface of the high-temperature oxidation film having a pie-skin-like structure of the TiO ₂ film formed on the Ti substrate. Although FIG. 16 is a monochrome photograph, it can be seen that the high temperature oxide film is white.
(3) Subsequently, Au colloid impregnation was performed on the _{TiO 2 coating.} Ahead of the TiO ₂ film 0.0825 wt% of tetrachloroauric (III) acid 4 was immersed in hydrate (HAuCl ₄ · _4H 2 O) in an aqueous solution, the vacuum impregnation once (n = 1) or 10 times After (n = 10), the mixture was dried in a thermostat kept at 30 ° C. for 24 hours. During this process, the coating changed from white to pink.
_{(4) Next, the SiO 2} gel was introduced into the void layer of the dried film by the vacuum impregnated sol-gel method. _{The SiO 2 was} prepared by the vacuum impregnated sol-gel method by hydrolysis using TEOS as the main agent. Specifically, pure water (10 g) and ethanol (10 g) were added to TEOS (42 g), and the sol was immersed in a _{TiO 2 membrane in a vacuum while stirring.}
(5) Then, low temperature drying was performed at 60 ° C. (333K) for about overnight. As a result, the silica sol vacuum-impregnated in the void layer was made into silica gel.
(6) Next, high temperature drying was performed at 600 ° C. for 100 minutes (6.0 ks). As a result, the silica gel in the void layer was crystallized.
Through the above steps, an Au-containing composite layered structure of Example 3 was obtained.
FIG. 17 shows the surface of the Au-containing composite layered structure in which the oxide film of FIG. 16 was impregnated with an aqueous solution of chloroauric acid 10 times (n = 10) and then vacuum impregnated _{to composite a SiO 2 gel.} It is a photograph to show. According to the Au-containing composite layered structure that has been impregnated with an aqueous solution of chloroauric acid 10 times (n = 10), the surface color is pink due to the inclusion of Au colloid that has the effect of increasing the reflectance on the long wavelength side of visible light. Coloring was confirmed.

(Measurement of oxide film color with a spectrophotometer)
In order to quantitatively evaluate the color tone, the color of the surface oxide film was measured using a spectrophotometer and quantified by the L * a * b * color system. Here, L * corresponds to the lightness, a * corresponds to the hue of red-green, and b * corresponds to the hue of yellow-blue. As the colorimeter, CM-5 manufactured by Konica Minolta was used.
FIG. 18 shows _{the surface of a high-temperature oxide film (Oxidation only) having a pie-skin-like structure of the TiO 2} film of FIG. 16 and a gold chloride aqueous solution impregnation treatment once (n = 1) or 10 times (n = 10). It is a graph which shows the spectrophotometric result about the surface of the Au-containing composite layered structure in which the _{SiO 2} gel is composited by performing the vacuum impregnation treatment after that.
The surface of the high-temperature oxide film (Oxidation only) having a pie-skin-like structure of TiO _{2 film was 90.56 for L *, −0.35 for a *, and 10.68 for b *.} The Au-containing composite layered structure (n = 1) subjected to the chloroauric acid aqueous solution impregnation treatment once had an L * of 89.22, a * of 0.44, and b * of 9.16. The Au-containing composite layered structure (n = 10) subjected to the chloroauric acid aqueous solution impregnation treatment 10 times had an L * of 65.58, a * of 6.22, and b * of 2.59.
As shown in FIG. 18, the addition of Au reduced the values of L * indicating whiteness and b * indicating yellowness, and a * was a negative value (green) before compounding, but n = At 1, it increased to a positive value (red), and at n = 10, it increased to about a * = 6, that is, the redness increased. This is believed to tetrachloroauric (III) acid tetrahydrate (HAuCl ₄ · _4H 2 O) is then immersed in TiO ₂ in the coating, changes in the gold colloid was colored red so-called gold red Be done.

(Surface analysis by X-ray photoelectron spectroscopy)
For the Au-added TiO ₂ / SiO ₂ composite layered structural coating (n = 10), the Au 4f spectrum by XPS was measured and state analysis was performed on the outermost surface and the coating surface excluding the surface layer by polishing.
FIG. 19 is a graph showing the Au 4f spectrum of the Au-added TiO ₂ / SiO ₂ composite layered structural coating (n = 10) with respect to the outermost surface by XPS. FIG. 20 is a graph showing the Au 4f spectrum by XPS for the coating surface excluding the surface layer by polishing.
As shown in FIGS. 19 and 20, Au in a metallic state was detected on both the coating surface and the polished surface. Since the spectral intensity of the outermost surface is high, Au is more abundant on the surface than inside the coating film, but it was confirmed that Au is also filled inside the coating film by vacuum impregnation.

(Example 4)
Example 4 relates to an Ag-containing TiO ₂ / SiO ₂ composite layered structure and a method for producing the same.

(Film preparation)
(1) First, a TiO ₂ coating having a pie crust-like structure is prepared. In the preparation of this film, the high temperature oxidation process and the vacuum impregnation process are substantially the same as in Example 1. Commercially Pure Titanium, Grade 2 (hereinafter, "CP Ti") was cut to a thickness of 1 mm with a fine cutter. Then, in order to make the surface texture uniform, it was polished to # 4000 using emery paper. In addition, the test piece was ultrasonically cleaned and dried in acetone to eliminate contamination of the test piece surface with deposits. The Ti substrate was prepared by the above.
(2) Next, using a heat treatment furnace, the Ti substrate was held in the air at 1000 ° C. (1273 K) for 30 minutes (1.8 ks), then cooled in the furnace, and surface oxidation treatment was performed.
(3) Using the obtained TiO _{2 coating, an Ag-containing TiO 2} / SiO ₂ composite layered structure coating was produced by a vacuum impregnated sol-gel method. It was hydrolyzed using TEOS as the main agent. Specifically, pure water (10 g), ethanol (10 g), and silver nitrate (concentration: 0.4 mol%, 0.2 mol%, 0.04 mol%) are added to the main agent TEOS (42 g), and the sol is stirred while stirring. Was immersed in a _{TiO 2 film in vacuum.} The Ag salt may be added to either the main agent TEOS or water.
(5) Then, low temperature drying was performed at 60 ° C. (333K) for about overnight. As a result, the silica sol vacuum-impregnated in the void layer was made into silica gel.
(6) Next, high temperature drying was performed at 600 ° C. for 100 minutes (6.0 ks). As a result, the silica gel in the void layer was crystallized.
Through the above steps, an Ag-containing composite layered structure of Example 4 was obtained.
FIG. 21 is a photograph of the surface of the obtained Ag-containing composite layered structure. As shown in FIG. 21, it was confirmed that the surface was colored with light gray tea, which was considered to be due to the formation of silver oxide.

(Surface analysis by X-ray photoelectron spectroscopy)
The state of the surface of the Ag-containing TiO ₂ / SiO ₂ composite layered structure was analyzed by measuring the Ag 3d spectrum by XPS. FIG. 22 is a graph showing the Ag 3d spectrum by XPS on the surface of _{the Ag-containing TiO 2} / SiO ₂ composite layered structure when the Ag concentration is 0.04 mol%. FIG. 23 is a graph showing the Ag 3d spectrum by XPS on the surface of _{the Ag-containing TiO 2} / SiO ₂ composite layered structure when the Ag concentration is 0.4 mol%.
As shown in FIGS. 22 and 23, it was confirmed that the Ag present in the coating film was present in a metallic state, and the content thereof depended on the amount of Ag added.

(Antibacterial evaluation)
The antibacterial property of the Ag-containing TiO ₂ / SiO ₂ composite layered structure was evaluated. The antibacterial property evaluation was carried out by the shake method in accordance with the method specified by the Antibacterial Product Technology Council. This shake method is effective for materials for which a smooth surface cannot be secured. In the shake method, a sample having a surface area of 32 ± 5 cm ² and 10 ml of a bacterial solution are placed in a sterile cup (flask), cultured with shaking at a temperature of 35 ° C. for 24 ± 1 hours, and then cultured on an agar medium for 40 to 48 hours. Later, the viable cell count is measured.
Three types of samples were used: a titanium plate (CP Ti), a TiO ₂ / SiO ₂ composite layered structure of Example 1, and an Ag-containing TiO ₂ / SiO ₂ composite layered structure of Example 4. There was. The number of test samples was 2 for the titanium plate, 3 for the TiO ₂ / SiO ₂ composite layered structure of Example 1, and 3 for the Ag-containing TiO ₂ / SiO ₂ composite layered structure of Example 4. Using. The test strain was Escherichia coli and the strain was ATCC 25922. The number of disseminated bacteria was 1 × 10 ⁴ CFU · mL ^-1 .

FIG. 24A is a photograph showing the state of the surface of the agar medium when the sample is a titanium plate (CP Ti). FIG. 24B is a photograph showing the state of the surface of the agar medium when the _{sample is the TiO 2} / SiO _{2 composite layered structure of Example 1.} FIG. 24C is a photograph showing the state of the surface of the agar medium when the sample is the Ag-containing TiO ₂ / SiO _{2 composite layered structure of Example 4.}
When the sample was a titanium plate (CP Ti), the viable cell count was 0.9 × 10 ⁴ CFU · mL ^-1 , and the standard deviation was 0.11 CFU · mL ^-1 . When the sample is the TiO ₂ / SiO ₂ composite layered structure of Example 1, the viable cell count is 1.44 × 10 ⁴ CFU · mL ^-1 , and the standard deviation is 0.04 CFU · mL ^-1 . there were. When the sample is the Ag-containing TiO ₂ / SiO ₂ composite layered structure of Example 4, the viable cell count is 0 CFU · mL ^-1 and the standard deviation is 0 CFU · mL ^-1 in each sample. there were.
From the above results, it was possible to confirm the excellent antibacterial properties of _{the Ag-containing TiO 2} / SiO _{2 composite layered structure of Example 4.}

In the field of dentistry, in recent years, the demand for metals and non-metals has been increasing due to the instability of the precious metal market, the increasing demand of patients for more naturalness, and the sophistication of resins and ceramics. However, the above characteristics are still advantageous for metals, and dental professionals have long sought a "white metal" that combines the excellent mechanical properties and dimensional stability of metals with aesthetics. There is. INDUSTRIAL APPLICABILITY According to the present invention, Ti becomes a technology that realizes the "white metal" and provides not only patients but also dentists and dental technicians with higher satisfaction and operability than conventional materials.

In particular, the present invention targets abutment, resin muzzle loader, and abutment tooth opaque of porcelain-baked cast crown. These have been regarded as problems since the exposure of the metal core due to gingival recession due to aging and the appearance of the black margin at the gingival margin are combined, and by suppressing the exposure of the metal surface of these members by this technology, the above-mentioned It is expected that the problem can be reduced or solved, which can reduce the psychological burden on the patient. According to the present invention, it is possible to control the color including redness in the white composite layered structure coating, and it can be expected to be applied to the anterior teeth in which the color difference from the adjacent healthy teeth is conspicuous. It can also be expected to be applied to a Ti denture base that covers the mucous membrane.

In addition, the imparting of antibacterial properties is expected to have an effect of suppressing the formation of a biofilm on the surface, which makes it possible to maintain the stability of the surface of the prosthesis, which in turn brings about an improvement in treatment results. In addition, the improved maintainability reduces the burden on dentists and hygienists.

Furthermore, the production of dental prostheses has shifted from the conventional total manual work by technicians to automation using CAD / CAM and 3D printers in recent years. This technology is relatively simple in the process itself and can be incorporated into those automation processes as a post process. If this happens, it will be possible to provide high value-added prostheses that not only reduce production time and cost, but also have better functions.

It should be noted that the present disclosure includes appropriately combining any of the various embodiments and / or examples described above, and the respective embodiments and / or embodiments. The effects of the examples can be achieved.

According to the composite layered structure according to the present invention, peel strength and hardness are greatly improved compared to the pie skin-like structure of the original TiO ₂ film. Therefore, in the field of dental treatment and orthodontics, it has the potential to be extremely effective not only in terms of functionality such as durability, but also in the field of aesthetics, which has been particularly in high demand in recent years, to realize "healthy teeth that shine white". ing.

1 Ti substrate 2 TiO ₂ layer 3 Void layer 4 SiO ₂ layer 5 Via 6 TiO ₂ Columnar part (skeleton)
7 Pie skin-like structure 8 Laminated body 10 Composite layered structure

Claims (10)

Ti board and
And a gap other than the above TiO ₂ backbone between the Ti substrate 2 layer TiO ₂ layer and the second layer of TiO ₂ skeleton and the two-layer TiO ₂ layer connecting the TiO ₂ layer of which is provided on the surface of a pie skin-like structure but which are laminated, and the laminated body in which a SiO ₂ layer occupying the gap, are stacked,
A composite layered structure containing. _{The composite layered structure according to claim 1, wherein the thickness of the TiO 2} layer of the laminated body is in the range of 0.5 μm to 5 μm. The composite layered structure according to claim 1 or 2, _{wherein the thickness of the SiO 2} layer of the laminated body is in the range of 0.2 μm to 5 μm. The laminate, the two-layer TiO ₂ layer and said TiO ₂ skeleton and the SiO ₂ layer is stacked over a plurality of sets, the composite layered structure according to any one of claims 1 3 .. The composite layered structure according to any one of claims 1 to 4, wherein the thickness of the laminated body is 10 μm or more. The composite layered structure according to any one of claims 1 to 5, wherein the lightness L * value in the L * a * b * color system is 70 or more. The composite layered structure according to any one of claims 1 to 6, wherein the SiO _{2 layer of the laminated body contains Au colloid or Ag ion.} By heating the Ti substrate at a temperature above 800 ° C. in an oxidizing atmosphere, on the Ti substrate, the two layers of TiO ₂ backbone connecting the TiO ₂ layer with TiO ₂ layer of the two layers of the said two layers TiO A heat oxidation treatment step of forming a pie crust-like structure in which a void layer other than the skeleton of the _{TiO 2} between the _{two layers is laminated.}
The Si-containing alkoxide of the silica precursor is hydrolyzed and polycondensed by the vacuum-impregnated sol-gel method, and the obtained silica sol is impregnated into the void layer of the pie crust-like structure, and at least a part of the silica sol. Vacuum impregnation process and
A drying step of drying the silica gel and
A heating step of heating the silica gel at a temperature equal to or higher than the crystallization temperature to crystallize the silica gel.
A method for producing a composite layered structure including. The method for producing a composite layered structure according to claim 8, further comprising a gold impregnation step of vacuum impregnating the pie crust-like structure with an Au colloidal solution or a gold chloride aqueous solution before the vacuum impregnation step. The method for producing a composite layered structure according to claim 8 or 9, wherein silver nitrate is added to the silica precursor in the vacuum impregnation step.

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