JP4771368B2 - Vehicle parts - Google Patents

Description

  The present invention relates to a vehicle component having a layer of at least a surface layer made of carbon-doped titanium oxide or titanium alloy oxide, and formed by a member doped with the carbon in a Ti-C bond state. Specifically, carbon is doped and formed in a Ti-C bond state, and has excellent durability (high hardness, scratch resistance, abrasion resistance, chemical resistance, heat resistance) and a visible light responsive photocatalyst. The present invention relates to a vehicle component formed by a member having a layer functioning as a motor.

Conventionally, titanium dioxide TiO ₂ (simply referred to as titanium oxide in the present specification and claims) is known as a substance exhibiting a photocatalytic function. As a method of forming a titanium oxide film on titanium metal, since the 1970s, a method of forming a titanium oxide film on titanium metal by anodic oxidation, thermal titanium oxide on a titanium metal plate in an electric furnace supplied with oxygen A method of forming a film, a method of forming a titanium oxide film on titanium metal by heating a titanium plate in a flame of city gas at 1100 to 1400 ° C. are known (see Non-Patent Document 1).

  When producing photocatalyst products that can provide deodorant, antibacterial, anti-fogging and antifouling effects by such photocatalytic function, titanium oxide sol is generally applied to the substrate by spray coating, spin coating, dipping, etc. (For example, refer to Patent Documents 1 to 3). However, since the film formed in this manner is easily peeled off or worn, it has been difficult to use for a long time. In addition, the method of forming a photocatalyst film | membrane by sputtering method is also known (for example, refer patent documents 4-5).

  In addition, in order to make titanium oxide function as a photocatalyst, ultraviolet rays having a wavelength of 400 nm or less are necessary. However, many studies of titanium oxide photocatalysts that function by visible light by doping various elements have been conducted. For example, comparing titanium oxides doped with F, N, C, S, P, Ni, etc., there is a report that nitrogen-doped titanium oxide is superior as a visible light responsive photocatalyst (see Non-Patent Document 2). .

In addition, titanium oxide photocatalysts doped with other elements in this way include titanium compounds in which the oxygen sites of titanium oxide are replaced with atoms such as nitrogen, and atoms such as nitrogen are doped between the lattices of titanium oxide crystals. There has been proposed a photocatalyst comprising a titanium compound or a titanium compound in which atoms such as nitrogen are arranged at grain boundaries of a polycrystalline aggregate of titanium oxide crystals (see, for example, Patent Documents 6 to 9). However, such a photocatalyst is not always satisfactory in terms of durability such as wear resistance. Further, for example, n-TiO ₂ -xCx, which is a chemically modified titanium oxide, is obtained by applying a natural gas combustion flame in which the temperature of the combustion flame is maintained at around 850 ° C. by adjusting the flow rates of natural gas and oxygen to titanium metal. There is a report that this absorbs light of 535 nm or less (see Non-Patent Document 3).

  Furthermore, crystal nuclei prepared by various production methods such as CVD or PVD are put into a sol solution composed of an inorganic metal compound or an organometallic compound, or a sol solution is applied to the crystal nuclei, solidified, and heat-treated. It is known that a highly active photocatalytic function can be obtained by growing a titanium oxide crystal from the crystal nucleus, whereby the crystal shape of the titanium oxide crystal grown from the crystal nucleus forms a columnar crystal (for example, (See Patent Documents 10 to 12). However, in that case, since the columnar crystal is merely grown from the seed crystal placed on the substrate, the formed columnar crystal has insufficient adhesion strength to the substrate, and thus was produced as such. The photocatalyst is not always satisfactory in terms of durability such as wear resistance.

Conventionally, it has been proposed to form a vehicle part such as a part used as an interior of a car or a part used by being mounted outside a car with a photocatalyst (see, for example, Patent Documents 13 to 14). .
JP 09-2441038 A Japanese Patent Application Laid-Open No. 09-262481 Japanese Patent Laid-Open No. 10-053437 JP-A-11-012720 JP 2001-205105 A JP 2001-205103 A (Claims) JP 2001-205094 A (Claims) JP 2002-95976 A (Claims) WO 01/10553 pamphlet (claims) JP 2002-253975 A JP 2002-370027 A JP 2002-370034 A JP 2004-262338 A JP 2001-26216 A A. Fujishima et al., J. Electrochem. Soc. Vol. 122, No. 11, p. 1487-1489, November 1975 R. Asahi et al., SCIENCE Vol. 293, July 13, 2001, p. 269-271 Shahed UM Khan et al., SCIENCE Vol. 297, September 27, 2002, p. 2243-2245

  Here, conventional titanium oxide photocatalysts have problems in durability (high hardness, scratch resistance, abrasion resistance, chemical resistance, heat resistance), both of which are UV responsive and visible light responsive. It became a bottleneck in terms of practical use.

  On the other hand, parts of vehicles such as automobiles, motorcycles, bicycles and the like are difficult to avoid because they travel on various places including bad roads, especially depending on the installation site on the vehicle and the function of the parts themselves. In a severe environment. Accordingly, the photocatalyst used for forming the vehicle component is required to have excellent durability.

  Therefore, the present invention is for a vehicle having a carbon-doped titanium oxide layer that is excellent in durability (high hardness, scratch resistance, abrasion resistance, chemical resistance, heat resistance) as a surface layer and functions as a visible light responsive photocatalyst. The purpose is to provide parts.

  In addition, the present invention can easily adsorb VOC, has a large surface area and is carbon-doped, so has high activity as a photocatalyst and functions as a visible light responsive photocatalyst, and has peeling resistance, abrasion resistance, and chemical resistance. The object is to provide a vehicle component having excellent heat resistance.

As a result of intensive studies to achieve the above-mentioned object, the present inventor heat-treats the surface of a substrate whose surface layer is made of titanium or a titanium alloy at a high temperature using a combustion flame of a gas containing hydrocarbon as a main component. As a result, carbon is doped in a Ti-C bond state, and has excellent durability (high hardness, scratch resistance, abrasion resistance, chemical resistance, heat resistance) and functions as a visible light responsive photocatalyst. It has been found that a member useful for application to a vehicle component having carbon-doped titanium oxide as a surface layer (hereinafter referred to as “multifunctional material”) has been obtained, and the present invention has been completed.

  That is, the vehicle component of the present invention has at least a surface layer made of a carbon-doped titanium oxide layer by heat treatment under predetermined conditions, and the carbon is doped in a Ti-C bond state, and has excellent durability and visible light. It is formed of a multifunctional material that functions as a responsive photocatalyst.

A surface of a substrate made of titanium or a titanium alloy is subjected to heat treatment under specific conditions by directly applying a flame of unsaturated hydrocarbon, particularly acetylene, or the surface of the substrate is unsaturated hydrocarbon under specific conditions; In particular, by performing heat treatment in an acetylene combustion exhaust gas atmosphere, a layer in which fine columns made of titanium oxide or titanium alloy oxide are formed is formed inside the surface layer, and the fine columns are established. A layer is cut in a direction along the surface layer, and at least a part of the substrate is exposed to a layer in which fine columns made of the titanium oxide or titanium alloy oxide are exposed, and oxidized on the thin film. A plurality of continuous narrow protrusions made of titanium or titanium alloy oxide and a member in which fine columns standing on the protrusions are exposed, that is, both of which are at least a part of the surface Having a large number of protrusions made of titanium oxide or titanium alloy oxide, both of which are useful multifunctional materials, and a fine column that is a protrusion made of the titanium oxide or titanium alloy oxide, Since the continuous narrow protrusions are carbon-doped, it has high photocatalytic activity, functions as a visible light responsive photocatalyst, can easily adsorb VOC, has high hardness, peel resistance, wear resistance, The present inventors have found that a multifunctional material excellent in chemical properties and heat resistance can be obtained.

Multifunctional materials This durability (high hardness, scratch resistance, abrasion resistance, chemical resistance, heat resistance) because it functions as an excellent and visible-light-responsive photocatalyst, only be used as a visible-light-responsive photocatalyst In addition, the present invention can also be used significantly for various vehicle parts for which hard chrome plating has been conventionally used. Further, pitting and general corrosion by lowering the potential of the substrate, as well as applications to those for the purpose of prevention of stress corrosion cracking, etc. can be expected.

Multifunctional materials Matako has high photocatalytic activity, and functions as a visible-light-responsive photocatalyst, further VOC also easily adsorb hardness is high, peeling resistance, wear resistance, chemical resistance, excellent heat resistance ing.

Therefore, not only can be reduced in weight by forming a vehicle component multifunctional material of this, it has excellent durability such as the height of the hardness, also excellent effect of the visible light responsive photocatalyst The vehicle component provided with can be provided.

Hereinafter, the best mode for carrying out the present invention will be described.

  The vehicle component of the present embodiment is characterized in that a predetermined multifunctional material is used for at least a part of the members. Therefore, in the following, first, the multifunctional material will be described in detail, and then a vehicle component using the multifunctional material (vehicle component material) will be described.

[About multifunctional materials]
The multifunctional material used in the vehicle parts of the present invention is a heat treatment of at least the surface of a substrate whose surface layer is made of titanium or a titanium alloy at a high temperature using, for example, a combustion flame of a gas mainly composed of hydrocarbons. However, the substrate whose at least surface layer is made of titanium or a titanium alloy is composed of the surface portion forming layer and the core material even if the entire substrate is made of titanium or a titanium alloy. These materials may be different. In addition, regarding the shape of the substrate, the final product shape (flat or three-dimensional) where durability such as high hardness, scratch resistance, abrasion resistance, chemical resistance, and heat resistance is desired, or visible light on the surface It may be a final product shape that is desired to have a responsive photocatalytic function.

If at least the surface layer is made of titanium or a titanium alloy and the surface portion forming layer and the core material are made of different materials, the thickness of the surface portion forming layer is the carbon-doped oxidation formed. It may be the same as the thickness of the titanium layer (that is, the entire surface portion forming layer becomes a carbon-doped titanium oxide layer) or may be thick (that is, a portion of the surface portion forming layer in the thickness direction is carbon-doped oxidized. It becomes a titanium layer and a part remains as it is). The material of the core material is not particularly limited as long as it does not burn, melt or deform during the heat treatment in the manufacturing method of the first invention. For example, iron, iron alloy, non-ferrous alloy, ceramics, other ceramics, high temperature heat resistant glass, etc. can be used as the core material. Examples of the substrate composed of such a thin film-like surface layer and a core material include, for example, those obtained by forming a film made of titanium or a titanium alloy on the surface of the core material by a method such as sputtering, vapor deposition, or thermal spraying. Can do.

  Various known titanium alloys can be used as the titanium alloy, and are not particularly limited. For example, Ti-6Al-4V, Ti-6Al-6V-2Sn, Ti-6Al-2Sn-4Zr-6Mo, Ti-10V-2Fe-3Al, Ti-7Al-4Mo, Ti-5Al-2.5Sn, Ti- 6Al-5Zr-0.5Mo-0.2Si, Ti-5.5Al-3.5Sn-3Zr-0.3Mo-1Nb-0.3Si, Ti-8Al-1Mo-1V, Ti-6Al-2Sn-4Zr- 2Mo, Ti-5Al-2Sn-2Zr-4Mo-4Cr, Ti-11.5Mo-6Zr-4.5Sn, Ti-15V-3Cr-3Al-3Sn, Ti-15Mo-5Zr-3Al, Ti-15Mo-5Zr, Ti-13V-11Cr-3Al or the like can be used.

  In the production of the multifunctional material, it is possible to use a combustion flame of a gas mainly composed of hydrocarbon, particularly acetylene, and it is particularly desirable to use a reducing flame. In the production of a multifunctional material, this hydrocarbon-based gas means a gas containing at least 50% by volume of hydrocarbon, for example, containing at least 50% by volume of acetylene, and appropriately air, hydrogen, oxygen It means the gas which mixed etc. In the production of this multifunctional material, the gas containing hydrocarbon as a main component preferably contains 50% by volume or more of acetylene, and the hydrocarbon is most preferably 100% of acetylene. When unsaturated hydrocarbons, especially acetylene having a triple bond, are used, in the process of combustion, especially in the reducing flame part, the unsaturated bond part decomposes to form an intermediate radical substance. It is considered that carbon doping is likely to occur because of its high activity.

In the production of a multifunctional material, when the surface layer of the substrate to be heat-treated is titanium or a titanium alloy, oxygen that oxidizes the titanium or titanium alloy is necessary, and air or oxygen must be included correspondingly. There is.

In the production of a multifunctional material, the surface of the substrate whose surface layer is made of titanium or a titanium alloy is heat-treated at a high temperature using a combustion flame of a gas mainly composed of hydrocarbons. Even if the combustion flame of a hydrocarbon-based gas is directly applied to the substrate, the surface of such a substrate is heated at a high temperature in a combustion gas atmosphere of a hydrocarbon-based gas. The heat treatment may be performed in a furnace, for example. When heat treatment is performed at a high temperature by directly applying a combustion flame, the above-described fuel gas may be burned in a furnace and the combustion flame may be applied to the surface of the substrate. When heat treatment is performed in a combustion gas atmosphere at a high temperature, the above fuel gas is burned in a furnace and the high-temperature combustion gas atmosphere is used.

  As for the heat treatment, the surface temperature of the substrate becomes 900 to 1500 ° C., preferably 1000 to 1200 ° C., and a carbon-doped titanium oxide layer doped with carbon in a Ti—C bond state is formed as the surface layer of the substrate. It is necessary to heat-treat. In the case of the heat treatment in which the surface temperature of the substrate ends below 900 ° C., the durability of the substrate having the carbon-doped titanium oxide layer obtained is insufficient and the photocatalytic activity under visible light is also insufficient. On the other hand, in the case of heat treatment where the surface temperature of the substrate exceeds 1500 ° C., the ultrathin film peels off from the surface of the substrate during cooling after the heat treatment, and the intended durability (high hardness, scratch resistance, (Abrasion resistance, chemical resistance, heat resistance) effect is not obtained. Moreover, even in the case of the heat treatment in which the surface temperature of the substrate is in the range of 900 to 1500 ° C., if the heat treatment time becomes long, the ultrathin film is peeled off from the surface of the substrate during cooling after the heat treatment, Since the intended durability (high hardness, scratch resistance, abrasion resistance, chemical resistance, heat resistance) cannot be obtained, the surface of the substrate will not peel off when cooled after heat treatment. It needs to be time. That is, the heat treatment time is sufficient to make the surface layer a carbon-doped titanium oxide layer doped with carbon in a Ti-C bond state. It must be a time that does not result in peeling of the thin film. This heat treatment time is correlated with the heating temperature, but is preferably about 400 seconds or less.

In the production of multifunctional materials, carbon dope doped with carbon containing 0.3 to 15 at%, preferably 1 to 10 at% of carbon in a Ti-C bond state by adjusting the heating temperature and heat treatment time. A titanium oxide layer can be obtained relatively easily. When the carbon doping amount is small, the carbon-doped titanium oxide layer is transparent, and as the carbon doping amount increases, the carbon-doped titanium oxide layer becomes translucent and opaque. Therefore, by forming a transparent carbon-doped titanium oxide layer on a transparent plate-shaped core material, it has excellent durability (high hardness, scratch resistance, abrasion resistance, chemical resistance, heat resistance) and visible light response A transparent plate that functions as a mold photocatalyst can be obtained, and durability (high hardness, scratch resistance, abrasion resistance) can be obtained by forming a transparent carbon-doped titanium oxide layer on a plate having a colored pattern on the surface. , A decorative plate that is excellent in chemical resistance and heat resistance) and functions as a visible light responsive photocatalyst. In the case where at least the substrate whose surface layer is made of titanium or a titanium alloy is composed of the surface portion forming layer and the core material, and the thickness of the surface portion forming layer is 500 nm or less, the melting point of the surface portion forming layer When heated to the vicinity, many small island-like undulations floating in the sea are generated on the surface and become translucent.

  In a multifunctional material having a carbon-doped titanium oxide layer doped with carbon in a Ti-C bond state, the thickness of the carbon-doped titanium oxide layer is preferably 10 nm or more, and has high hardness, scratch resistance, In order to achieve wearability, the thickness is more preferably 50 nm or more. When the thickness of the carbon-doped titanium oxide layer is less than 10 nm, the resulting multifunctional material having the carbon-doped titanium oxide layer tends to be insufficient. The upper limit of the thickness of the carbon-doped titanium oxide layer is not particularly limited, although it is necessary to consider the cost and the effect achieved.

  The carbon-doped titanium oxide layer of the multifunctional material is a titanium compound Ti formed by doping chemically modified titanium oxide as described in Non-Patent Document 3 or various atoms or anions X conventionally proposed. Unlike titanium oxide containing —O—X, it contains a relatively large amount of carbon, and doped carbon is contained in a Ti—C bond state. As a result, it is considered that mechanical strength such as scratch resistance and abrasion resistance is improved, and the Vickers hardness is remarkably increased. Moreover, heat resistance is also improved.

The carbon-doped titanium oxide layer of the multifunctional material has a Vickers hardness of 300 or more, preferably 500 or more, more preferably 700 or more, and most preferably 1000 or more. A Vickers hardness of 1000 or more is harder than that of hard chrome plating. Thus, multifunctional materials of this can be significantly utilized for any of various conventional hard chromium plating has been utilized.

  The carbon-doped titanium oxide layer, which is a multifunctional material, responds not only to ultraviolet rays but also to visible light having a wavelength of 400 nm or more, and functions effectively as a photocatalyst. Therefore, the first multifunctional material can be used as a visible light responsive photocatalyst and exhibits a photocatalytic function not only outdoors but also indoors. Further, the carbon-doped titanium oxide layer of the multifunctional material exhibits super hydrophilicity with a contact angle of 3 ° or less.

  Furthermore, the carbon-doped titanium oxide layer of the multifunctional material is excellent in chemical resistance, and after being immersed in an aqueous solution of 1M sulfuric acid and 1M sodium hydroxide for one week, the film hardness, abrasion resistance and photocurrent density are adjusted. When measured and compared with the measured value before treatment, no significant change was observed. Incidentally, with respect to commercially available titanium oxide films, generally, the binder dissolves in acid or alkali depending on the kind thereof, so that the film peels off, and there is almost no acid resistance and alkali resistance.

Further, the other multifunctional material used for the vehicle parts of the present invention is such that at least the surface of the substrate whose surface layer is made of titanium or a titanium alloy is heat-treated with a combustion flame of, for example, an unsaturated hydrocarbon, particularly acetylene, A layer with fine columns made of titanium oxide or titanium alloy oxide is formed inside the surface layer, and then, for example, a thermal stress, a shear stress, or a tensile force is applied to form a layer with the fine columns formed. Cut in a direction along the surface layer to expose a layer in which fine columns made of titanium oxide or titanium alloy oxide are forested on at least a part of the substrate, usually on the majority of the substrate. And a member in which a large number of continuous narrow protrusions made of titanium oxide or titanium alloy oxide on a thin film and a fine column standing on the protrusions are exposed. .

The substrate whose at least surface layer is made of titanium or a titanium alloy may be composed entirely of titanium or a titanium alloy, or a surface portion forming layer made of titanium or a titanium alloy and a core material made of other materials. It may be comprised. Further, the shape of the substrate may be any final product shape (flat plate shape or three-dimensional shape) where photocatalytic activity and / or super hydrophilicity is desired.

In the case where at least the substrate whose surface layer is made of titanium or a titanium alloy is composed of a surface portion forming layer made of titanium or a titanium alloy and a core material made of another material, the thickness (amount) of the surface portion forming layer ) Even if the thickness is comparable to the amount of layers in which fine columns made of titanium oxide or titanium alloy oxide are formed (that is, the entire surface layer forming layer is made of titanium oxide or titanium alloy oxide). The fine pillars become forested layers) and may be thicker (that is, the fine pillars in which part of the surface portion forming layer in the thickness direction is made of titanium oxide or titanium alloy oxide are forested. Layer, and the rest remains unchanged). The material of the core material is not particularly limited as long as it does not burn, melt or deform during the heat treatment in the production of the multifunctional material. For example, iron, iron alloy, non-ferrous alloy, glass, ceramics, and other ceramics can be used as the core material. As the substrate composed of such a thin film surface layer and a core material, the same ones as described above can be used. The thickness of this surface layer is preferably 0.5 μm or more, more preferably 4 μm or more.

As a titanium alloy, well-known various titanium alloys can be used, and there is no particular limitation, and those similar to the above are used.

In the production of a multifunctional material, for example, it is desirable to use a combustion flame of a gas mainly composed of unsaturated hydrocarbons, particularly acetylene, and particularly to use a reducing flame. Gas in the manufacture of the multifunctional material of this is containing at least 50 volume% of an unsaturated hydrocarbon, e.g., acetylene contains at least 50 volume%, suitably air, hydrogen, it is preferred to use a mixed gas of oxygen, etc. . In the production of the second multifunctional material, the fuel component is most preferably 100% acetylene. When unsaturated hydrocarbons, especially acetylene having a triple bond, are used, in the process of combustion, especially in the reducing flame part, the unsaturated bond part decomposes to form an intermediate radical substance. Has a strong activity, and carbon doping is likely to occur, and doped carbon is contained in a Ti-C bond state. Thus, when carbon dope arises in a micro pillar, the hardness of a micro pillar will become high, As a result, mechanical strength, such as hardness of a multifunctional material and abrasion resistance, will improve, and heat resistance will also improve.

In the production of the multifunctional material, the surface layer is heated by directly applying a combustion flame to the surface of the substrate made of titanium or a titanium alloy, or the surface of the substrate is heated in a combustion exhaust gas atmosphere. This heat treatment can be carried out, for example, with a gas burner or in a furnace. When the combustion flame is directly applied and heat treatment is performed at a high temperature, the combustion flame may be applied to the surface of the substrate by a gas burner. When heat treatment is performed in a combustion exhaust gas atmosphere at a high temperature, the above fuel gas may be burned in a furnace and an atmosphere containing the high-temperature combustion exhaust gas may be used.

For the heat treatment, at least the surface layer is made of titanium or a titanium alloy, a layer in which fine columns made of titanium oxide or a titanium alloy oxide are formed is formed inside the surface layer, and then, for example, thermal stress, shear stress, By applying a tensile force, the layer in which the fine columns are erected is cut in a direction along the surface layer, and at least a part of the titanium oxide or titanium alloy oxide is erected in at least a part of the substrate. A member in which a layer is exposed, and a member in which a large number of continuous narrow protrusions made of titanium oxide or titanium alloy oxide on a thin film and fine columns standing on the protrusions are exposed Therefore, it is necessary to adjust the heating temperature and the heat treatment time. This heat treatment is preferably performed at a temperature of 600 ° C. or higher.

By performing the heat treatment under such conditions, the height of the layer in which the fine pillars stand is about 1 to 20 μm, and the thickness of the thin film thereon is about 0.1 to 10 μm. Intermediates having an average thickness of about 0.2 to 3 μm are formed. Thereafter, for example, by applying a thermal stress, a shear stress, or a tensile force to cut the layer in which the fine pillars are erected in a direction along the surface layer, at least a part of the titanium oxide or the substrate is formed on the substrate. A member in which a layer with fine columns made of titanium alloy oxide is exposed (that is, all or most of the thin film existing on the layer with fine columns on the substrate is peeled off) However, a part of the thin film existing on the layer where the fine pillars are erected may remain without being peeled) and a large number of continuous narrow widths made of titanium oxide or titanium alloy oxide on the thin film A protrusion and a member in which a fine pillar standing on the protrusion is exposed are obtained.

  In the case of cutting a layer in which fine columns are erected by applying thermal stress in a direction along the surface layer, for example, either the surface or the back surface of the substrate is cooled or heated to heat the surface of the substrate. A temperature difference is provided between the back surface and the back surface. As this cooling method, for example, either the surface or the back surface of the hot intermediate is brought into contact with a cooling object, such as a stainless steel block, or cold air (room temperature air) is applied to either the surface or the back surface of the hot intermediate. Spray. Even if the hot intermediate is allowed to cool, thermal stress is generated, but the degree is low.

  When shearing stress is applied and the layer in which the fine pillars are erected is cut in a direction along the surface layer, for example, a relatively reverse force is applied to the front and back surfaces of the intermediate by frictional force. In addition, when a layer in which fine columns are erected is cut in a direction along the surface layer by applying a tensile force, for example, the surface and the back surface of the above intermediate body are removed from those surfaces using a vacuum suction disk or the like. Pull in the opposite direction in the vertical direction. When using only a member in which a layer in which fine columns made of titanium oxide or titanium alloy oxide are forested is exposed on at least a part of the substrate, oxidation is performed on the intermediate thin film. A portion corresponding to a member in which a large number of continuous narrow protrusions made of titanium or a titanium alloy oxide and fine columns standing on the protrusions are exposed can be removed by polishing, sputtering, or the like.

  In a member in which a layer with fine columns made of titanium oxide or titanium alloy oxide is exposed on at least a part of the substrate obtained as described above, the layer with fine columns is set Although the height of the layer in which the fine column stands is changed depending on the height position of the fine column cut in the direction along the surface layer, the height of the layer in which the fine column stands is generally 1 to The average thickness of the fine columns is about 0.5 to 3 μm. This member is a multifunctional material that can easily adsorb VOC, has a large surface area, has high activity as a photocatalyst, and also has high film hardness, exfoliation resistance, abrasion resistance, chemical resistance, and heat resistance. is there.

On the other hand, on the thin film obtained as described above, a large number of continuous narrow protrusions made of titanium oxide or titanium alloy oxide and members with exposed fine columns standing on the protrusions are small. The height of the protrusion on each small piece is about 2 to 12 μm, and the height of the fine column is the height of the fine column obtained by cutting the layer in which the fine column stands in the direction along the surface layer. Although the height varies depending on the position, the height of the layer in which the fine pillars stand is generally about 1 to 5 μm, and the average thickness of the fine pillars is about 0.2 to 0.5 μm. However, depending on the conditions for cutting the layer in which the fine columns are erected in the direction along the surface layer, there are cases where a large number of continuous narrow protrusions are exposed without the presence of the fine columns. This member can also adsorb VOCs and has a large surface area, so it has high activity as a photocatalyst. Further, this member can be used as it is or after being pulverized, and the pulverized product can easily adsorb VOC and has a large surface area, so it has high activity as a photocatalyst.

In multifunctional material of this, since the minute columns consisting of titanium oxide or a titanium alloy oxide, numerous continuous narrow projections and micro columns protruding have bristled on raised portion is carbon doped, ultraviolet Of course, it also responds to visible light having a wavelength of 400 nm or more, acts particularly effectively as a photocatalyst, can be used as a visible light responsive photocatalyst, and exhibits a photocatalytic function not only outdoors but also indoors.

The shape of each of the minute columns of layers of titanium oxide or fine columns made of titanium alloy oxide is bristled constituting the multifunctional material of this, as judged from photomicrographs of FIGS. 10 and 13, Prismatic, cylindrical, pyramidal, conical, inverted pyramid or inverted conical, etc., extending straight or perpendicular to the surface of the substrate, extending while curving or bending, There are ones that branch out and extend, and those that are complex. Moreover, as the whole shape, it can show by various expressions, such as a frost column shape, a raising carpet shape, a basket shape, a row column shape, and the column shape assembled with blocks. In addition, the thickness and height of the fine columns, the size of the base (bottom surface), and the like vary depending on heating conditions and the like.

  A member in which a large number of continuous narrow protrusions made of titanium oxide or a titanium alloy oxide in a thin film form and fine columns standing on the protrusions are exposed is judged from the micrograph in FIG. In addition, it can be seen that the many continuous narrow protrusions look like the outside of the walnut shell and the appearance of pumice. It can be seen that the pattern is bent. In addition, the shape of the fine column standing on the protrusion is the same as the shape of each fine column in the layer where the fine column on the base is standing, but the junction between the fine column and the thin film Therefore, the density of the fine columns standing on the protrusion is generally smaller than the density of the fine columns in the layer where the fine columns on the base are standing.

  Hereinafter, the present invention will be described in more detail based on examples and comparative examples.

[Examples 1 to 3]
Carbon dope in which carbon is doped in a Ti—C bond state as a surface layer by heat-treating a titanium plate having a thickness of 0.3 mm using an acetylene combustion flame so that its surface temperature is about 1100 ° C. A titanium plate having a titanium oxide layer was formed. By adjusting the heat treatment time at 1100 ° C. to 5 seconds (Example 1), 3 seconds (Example 2), and 1 second (Example 3), respectively, the amount of carbon doping and the thickness of the carbon-doped titanium oxide layer were reduced. Titanium plates with different carbon doped titanium oxide layers were formed.

The carbon content was calculated | required with the fluorescent-X-ray-analysis apparatus about the carbon dope titanium oxide layer with which the carbon formed in this Example 1-3 was doped in the state of Ti-C bond. Assuming a molecular structure of TiO _2-x C x based on the carbon content, carbon content 8at% for Example 1, TiO _{1. 76} C _0.24, carbon content of about 3.3At% for Examples 2, TiO _1.90 C _0.10 and Example 3 had a carbon content of 1.7 at% and TiO _1.95 C _0.05 . In addition, the carbon-doped titanium oxide layer in which the carbon formed in Examples 1 to 3 was doped in a Ti—C bond state was superhydrophilic with a contact angle of about 2 ° with water droplets.

[Comparative Example 1]
A commercially available titanium oxide sol (STS-01 manufactured by Ishihara Sangyo Co., Ltd.) was spin-coated on a titanium plate having a thickness of 0.3 mm, and then a titanium plate having a titanium oxide film whose adhesion was improved by heating was formed.

[Comparative Example 2]
A commercially available product in which titanium oxide was spray-coated on a SUS plate was used as the substrate having the titanium oxide film of Comparative Example 2.

Test Example 1 (Vickers hardness)
The carbon-doped titanium oxide layer doped with the carbon of Example 1 in a Ti—C bond state and the titanium oxide film of Comparative Example 1 were subjected to indenter: Belkovic using a nanohard nesting tester (NHT) (manufactured by CSM Instruments, Switzerland). When the film hardness was measured under the conditions of type, test load: 2 mN, load unloading speed: 4 mN / min, the carbon-doped titanium oxide layer doped with carbon in the state of Ti-C bond in Example 1 had a Vickers hardness. Was a high value of 1340. On the other hand, the Vickers hardness of the titanium oxide film of Comparative Example 1 was 160.

  These results are shown in FIG. For reference, the literature values of Vickers hardness of hard chrome plating layer and nickel plating layer (Tomono, “Practical Plating Manual”, Chapter 6, Ohmsha (1971)) are also shown. It is obvious that the carbon-doped titanium oxide layer in which the carbon of Example 1 is doped in a Ti—C bond state has higher hardness than the nickel plating layer and the hard chromium plating layer.

Test Example 2 (Scratch resistance)
For the carbon-doped titanium oxide layer doped with the carbon of Example 1 in a Ti—C bond state and the titanium oxide film of Comparative Example 1, a microscratch tester (MST) (manufactured by CSM Instruments, Switzerland) was used as an indenter: Rockwell. The scratch resistance test was performed under the conditions of (diamond), tip radius 200 μm, initial load: 0 N, final load: 30 N, load speed: 50 N / min, scratch length: 6 mm, stage speed: 10.5 mm / min. A “peeling start” load at which a small film peels off within the scratch mark and an “overall peel” load at which the film peels across the scratch mark were determined. The results were as shown in Table 1.

  As is apparent from this table, it can be seen that the carbon-doped titanium oxide surface layer of Example A is superior to the titanium oxide film of Comparative Example 1 in scratch resistance.

Test Example 3 (Abrasion resistance)
The carbon-doped titanium oxide layer doped with the carbon of Example 1 in a Ti—C bond state and the titanium oxide film of Comparative Example 1 were tested at a test temperature using a high-temperature tribometer (HT-TRM) (manufactured by CSM Instruments, Switzerland). A wear test was performed under the conditions of: room temperature and 470 ° C., ball: SiC sphere having a diameter of 12.4 mm, load: 1 N, sliding speed: 20 mm / sec, rotation radius: 1 mm, test rotation speed: 1000 rotations.

  As a result, for the titanium oxide film of Comparative Example 1, peeling occurred at both room temperature and 470 ° C., but for the carbon-doped titanium oxide layer in which the carbon of Example 1 was doped in a Ti—C bond state, No significant trace wear was detected under both room temperature and 470 ° C conditions.

Test Example 4 (Chemical resistance)
After immersing the titanium plate having the carbon-doped titanium oxide layer doped with the carbon of Example 1 in a Ti—C bond state in a 1M sulfuric acid aqueous solution and a 1M sodium hydroxide aqueous solution for 1 week at room temperature, When the wear resistance and the photocurrent density described below were measured, no significant difference was observed in the results before and after immersion. That is, it was confirmed that the carbon-doped titanium oxide layer in which the carbon of Example 1 was doped in a Ti—C bond state had high chemical resistance.

Test Example 5 (Structure of carbon-doped titanium oxide layer doped with carbon in a Ti-C bond state)
For the carbon-doped titanium oxide layer in which the carbon of Example 1 was doped in a Ti—C bond state, the acceleration voltage was 10 kV, the target was Al, and Ar ion sputtering was performed for 2700 seconds using an X-ray photoelectron spectrometer (XPS). Done and started the analysis. If this sputtering rate is 0.64 Å / s corresponding to the SiO ₂ film, the depth is about 173 nm. The result of the XPS analysis is shown in FIG. The highest peak appears when the binding energy is 284.6 eV. This is judged to be a C—H (C) bond commonly found in Cls analysis. The next highest peak is seen when the binding energy is 281.7 eV. Since the bond energy of the Ti—C bond is 281.6 eV, it is determined that C is doped as a Ti—C bond in the carbon-doped titanium oxide layer of Example 1. As a result of XPS analysis at 11 points at different positions in the depth direction of the carbon-doped titanium oxide layer, similar peaks appeared in the vicinity of 281.6 eV at all points.

  Ti-C bonds were also confirmed at the boundary between the carbon-doped titanium oxide layer and the substrate. Accordingly, the hardness is increased due to the Ti—C bond in the carbon-doped titanium oxide layer, and the film peeling strength is significantly increased due to the Ti—C bond at the boundary between the carbon-doped titanium oxide layer and the substrate. Is expected.

Test Example 6 (wavelength response)
The wavelength responsiveness of the carbon-doped titanium oxide layer in which the carbons of Examples 1 to 3 were doped in a Ti—C bond state and the titanium oxide films of Comparative Examples 1 and 2 were measured using an Oriel monochromator. Specifically, a voltage of 0.3 V was applied to each layer and film between the counter electrode in a 0.05 M aqueous sodium sulfate solution, and the photocurrent density was measured.

  The result is shown in FIG. FIG. 3 shows the obtained photocurrent density jp with respect to the irradiation wavelength. The wavelength absorption edge of the carbon-doped titanium oxide layer in which the carbons of Examples 1 to 3 are doped in a Ti—C bond state extends to 490 nm, and the photocurrent density increases as the carbon doping amount increases. Was recognized. Although not shown here, it has been found that when the carbon doping amount exceeds 10 at%, the current density tends to decrease, and when the carbon doping amount exceeds 15 at%, the tendency becomes remarkable. Therefore, it was recognized that the carbon doping amount has an optimum value of about 1 to 10 at%. On the other hand, in the titanium oxide films of Comparative Examples 1 and 2, it was confirmed that the photocurrent density was extremely small and the wavelength absorption edge was about 410 nm.

Test example 7 (light energy conversion efficiency)
For the carbon-doped titanium oxide layer in which the carbons of Examples 1 to 3 are doped in a Ti—C bond state and the titanium oxide films of Comparative Examples 1 and 2, the formula η = jp (Ews−Eapp) / I
The light energy conversion efficiency η defined by Here, Ews is the theoretical decomposition voltage of water (= 1.23 V), Eapp is the applied voltage (= 0.3 V), and I is the irradiation light intensity. The result is shown in FIG. FIG. 4 shows the light energy conversion efficiency η with respect to the irradiation light wavelength.

  As is clear from FIG. 4, the carbon-doped titanium oxide layer in which the carbons of Examples 1 to 3 are doped in a Ti—C bond state has extremely high light energy conversion efficiency, and the conversion efficiency in the vicinity of a wavelength of 450 nm is a comparative example. It was recognized that the conversion efficiency in the ultraviolet region (200 to 380 nm) of the 1 and 2 titanium oxide films was superior. Further, the water decomposition efficiency of the carbon-doped titanium oxide layer in which the carbon of Example 1 is doped in a Ti—C bond state is about 8% at a wavelength of 370 nm, and an efficiency exceeding 10% can be obtained at 350 nm or less. I understood.

Test Example 8 (Deodorization test)
A deodorizing test was performed on the carbon-doped titanium oxide layer in which the carbons of Examples 1 and 2 were doped in a Ti-C bond state and the titanium oxide film of Comparative Example 1. Specifically, after acetaldehyde generally used in deodorization tests is enclosed in a 1000 ml glass container together with a substrate having a carbon-doped titanium oxide layer, the influence of concentration reduction due to initial adsorption can be ignored. Visible light was irradiated with a fluorescent lamp with a UV cut filter, and the acetaldehyde concentration was measured by gas chromatography at every predetermined irradiation time. The surface area of each film was 8.0 cm ² .

  The result is shown in FIG. FIG. 5 shows the acetaldehyde concentration with respect to the elapsed time after irradiation with visible light. The acetaldehyde decomposition rate of the carbon-doped titanium oxide layers of Examples 1 and 2 is higher than the acetaldehyde decomposition rate of the titanium oxide film of Comparative Example 1, and the carbon doping amount is large. It was found that the carbon-doped titanium oxide layer of Example 1 having a higher energy conversion efficiency has a higher decomposition rate than the carbon-doped titanium oxide layer of Example 2.

Test example 9 (antifouling test)
An antifouling test was carried out on the carbon-doped titanium oxide layer of Example 1 and the titanium oxide film of Comparative Example 1. Each coating was placed in a smoking room in the Central Research Institute of Electric Power Co., Ltd., and surface contamination after 145 days was observed. There is no direct incidence of sunlight in the smoking room.

  A photograph showing the results is shown in FIG. Fat was attached to the surface of the titanium oxide film of Comparative Example 1 and had a pale yellow color, but the surface of the carbon-doped titanium oxide layer of Example 1 was not particularly changed and was kept clean. It was confirmed that the antifouling effect was sufficiently exhibited.

[Examples 4 to 7]
By using an acetylene combustion flame in the same manner as in Examples 1 to 3, a titanium plate having a thickness of 0.3 mm was heated at the surface temperature shown in Table 2 for the time shown in Table 2, thereby forming a surface layer. A titanium plate having a carbon-doped titanium oxide layer was formed.

[Comparative Example 3]
Using a natural gas combustion flame, a 0.3 mm thick titanium plate was heat-treated at the surface temperature shown in Table 2 for the time shown in Table 2.

Test Example 10
The Vickers hardness (HV) of the carbon-doped titanium oxide layers of Examples 4 to 7 and the film of Comparative Example 3 was measured in the same manner as in Test Example 1 above. The results are shown in Table 2. Moreover, the carbon dope titanium oxide layer formed in Examples 4-11 was super hydrophilicity whose contact angle with a water droplet was about 2 degrees.

  As is apparent from the data shown in Table 2, when the heat treatment was performed with the combustion gas of natural gas so that the surface temperature became 850 ° C., only a film having a Vickers hardness of 160 was obtained, but the surface temperature was 1000 ° C. In Examples 4 to 7 where heat treatment was performed using acetylene combustion gas as described above, a carbon-doped titanium oxide layer having a Vickers hardness of 1200 was obtained.

Test Example 11
For the carbon-doped titanium oxide layers of Examples 4 to 7 and the titanium oxide films of Comparative Examples 1 and 3, as in Test Example 6, a voltage of 0.3 V was applied between the counter electrode in a 0.05 M sodium sulfate aqueous solution. The photocurrent density was measured by irradiating with light of 300 nm to 520 nm. The result is shown in FIG. FIG. 7 shows the obtained photocurrent density jp with respect to the potential ECP (V vs. SSE).

  The carbon-doped titanium oxide layers of Examples 4 to 6 obtained by heat treatment using an acetylene combustion gas so that the surface temperature becomes 1000 to 1200 ° C. have relatively high photocurrent density and are excellent. all right. On the other hand, the titanium oxide of Comparative Example 3 obtained by heat treatment so that the surface temperature becomes 850 ° C. and the carbon-doped titanium oxide layer of Example 7 obtained by heat treatment so that the surface temperature becomes 1500 ° C. It was found that the current density was relatively small.

[Example 8]
A titanium alloy whose surface layer contains carbon-doped titanium oxide by heat treatment of a Ti-6Al-4V alloy plate having a thickness of 0.3 mm using an acetylene combustion flame so that its surface temperature is about 1100 ° C. An alloy plate made of The heat treatment time at 1100 ° C. was 60 seconds. The layer containing carbon-doped titanium oxide thus formed is superhydrophilic with a contact angle with water droplets of about 2 °, and has the same photocatalytic activity as that of the carbon-doped titanium oxide layer obtained in Example 4. showed that.

[Example 9]
A titanium thin film having a thickness of about 500 nm was formed on the surface of a stainless steel plate (SUS316) having a thickness of 0.3 mm by sputtering. A stainless steel sheet having a carbon-doped titanium oxide layer as a surface layer was formed by heat treatment using an acetylene combustion flame so that the surface temperature was about 900 ° C. The heat treatment time at 900 ° C. was 15 seconds. The carbon-doped titanium oxide layer thus formed is superhydrophilic with a contact angle with water droplets of about 2 °, and exhibits the same photocatalytic activity as the carbon-doped titanium oxide layer obtained in Example 4. It was.

[Example 10]
A titanium oxide powder having a particle size of 20 μm is supplied into an acetylene combustion flame, and is retained in the combustion flame for a predetermined time, and heat-treated so that the surface temperature is about 1000 ° C. A titanium powder having a layer was formed. The heat treatment time at 1000 ° C. was 4 seconds. The titanium powder having the carbon-doped titanium oxide layer formed as described above showed the same photocatalytic activity as that of the carbon-doped titanium oxide layer obtained in Example 4.

[Examples 11 to 12]
A titanium thin film having a thickness of about 100 nm was formed by sputtering on the surface of a 1 mm thick glass plate (Pyrex (registered trademark)). A glass plate having a carbon-doped titanium oxide layer as a surface layer is obtained by heat treatment using an acetylene combustion flame so that the surface temperature is 1100 ° C. (Example 11) or 1500 ° C. (Example 12). Formed. The heat treatment time at 1100 ° C. or 1500 ° C. was 10 seconds. The carbon-doped titanium oxide layer thus formed was transparent as shown in the photograph in FIG. 8A when the surface temperature was 1100 ° C., but when the surface temperature was 1500 ° C., FIG. As shown in FIG. 8, many small island-like undulations floating in the sea are generated on the surface, and it became translucent as shown in FIG.

[Examples 13 to 16]
The surface of the titanium plate having a thickness of 0.3 mm was subjected to heat treatment with an acetylene combustion flame at the surface layer temperature shown in Table 3 for the time shown in Table 3. After that, when the surface to which the flame is applied is brought into contact with a flat surface of a stainless steel block having a thickness of 30 mm and cooled, a layer in which fine columns made of white titanium oxide stand on the most part of the titanium plate surface is exposed. And a small piece member in which a large number of continuous narrow protrusions made of white titanium oxide on the thin film and fine columns standing on the protrusions are exposed. That is, the layer in which the fine columns made of titanium oxide formed in the surface layer by heat treatment are erected is cut in the direction along the surface layer by the subsequent cooling. In this way, Examples 13 to 16 were obtained.

  FIG. 10 is a photomicrograph of the member obtained in Example 13, in which a layer 2 in which fine columns made of white titanium oxide are forested is exposed on the titanium plate surface 1, and a white color is formed on the thin film. A state is shown in which a small piece member 3 in which a large number of continuous narrow protrusions made of titanium oxide and fine columns standing on the protrusions are exposed remains on a part of the layer 2. In addition, in the manufacturing method of Examples 13-16, although the titanium plate surface 1 is not exposed, the micrograph of FIG. 10 has shown the state which removed a part of layer 2 in which the fine pillar stands. FIG. 11 is a photomicrograph showing the state of the surface on the thin film side of the small piece member 3 in which a large number of continuous narrow protrusions made of white titanium oxide and thin columns standing on the protrusions are exposed on the thin film. FIG. 12 shows a number of continuous narrow widths of small piece members 3 in which a large number of continuous narrow-width projections made of white titanium oxide are exposed on a thin film and fine columns standing on the projections are exposed. FIG. 13 is a photomicrograph showing the state of the protrusion and the surface on the side where the fine pillar standing on the protrusion is exposed, and FIG. 13 is the state of the layer 2 where the fine pillar made of white titanium oxide is standing FIG.

[Example 17]
The surface of a Ti-6Al-4V alloy plate having a thickness of 0.3 mm was heat-treated with an acetylene combustion flame at the surface layer temperature shown in Table 3 for the time shown in Table 3. After that, when the surface to which the flame is applied is brought into contact with a flat surface of a stainless steel block having a thickness of 30 mm and cooled, a layer in which fine columns made of titanium alloy oxide stand on most of the surface of the titanium alloy plate is exposed. And a small piece member in which a number of continuous narrow protrusions made of titanium alloy oxide on the thin film and fine columns standing on the protrusions are exposed.

[Example 18]
A titanium thin film having a thickness of about 3 μm was formed on the surface of a stainless steel plate (SUS316) having a thickness of 0.3 mm by electron beam evaporation. The surface of the thin film was heat-treated with an acetylene combustion flame at the surface layer temperature shown in Table 3 for the time shown in Table 3. After that, when the surface to which the combustion flame is applied is brought into contact with a flat surface of a 30 mm thick stainless steel block and cooled, a layer in which fine columns made of white titanium oxide are forested is exposed on the majority of the surface of the stainless steel plate. And a small piece member in which a large number of continuous narrow protrusions made of white titanium oxide on the thin film and fine columns standing on the protrusions are exposed.

[Comparative Example 4]
A commercially available titanium oxide sol (STS-01 manufactured by Ishihara Sangyo Co., Ltd.) was spin-coated on a titanium plate having a thickness of 0.3 mm, and then a titanium plate having a titanium oxide film whose adhesion was improved by heating was formed.

Test Example 12 (Scratch hardness test: pencil method)
Mitsubishi Pencil Co., Ltd., based on JIS K 5600-5-4 (1999), on the surface of the fine column side of the member in which the layer in which the fine column is grown is exposed on the substrate surface obtained in Examples 13 to 18 A pencil scratch hardness test was carried out using Uni 1H-9H pencils. The results were as shown in Table 3. That is, no damage was observed when a 9H pencil was used for all the test pieces.

Test Example 13 (Chemical resistance test)
The members having exposed layers with fine pillars exposed on the substrate surfaces obtained in Examples 13 to 18 were immersed in 1M sulfuric acid aqueous solution and 1M sodium hydroxide aqueous solution for 1 week at room temperature, washed with water and dried. Then, the above scratch hardness test: the pencil method was carried out. The results were as shown in Table 3. That is, even when a 9H pencil was used for all the test pieces, no damage was observed, and it was confirmed that the test pieces had high chemical resistance.

Test example 14 (heat resistance test)
A member in which a layer in which fine columns are erected is exposed on the surface of the substrate obtained in Examples 13 to 18 is placed in a tubular furnace, and the temperature is raised from room temperature to 500 ° C. in an air atmosphere over 1 hour. After holding at a constant temperature of 500 ° C. for 2 hours and further allowing to cool to room temperature over 1 hour, the above-described scratch hardness test: pencil method was performed. The results were as shown in Table 3. That is, no damage was observed even when a 9H pencil was used for all the test pieces, and it was confirmed that the specimen had high heat resistance.

Test Example 15 (Anti-fouling test)
As a sample, a titanium plate surface area 8 cm ² having a titanium oxide film obtained in member and Comparative Example 4 of surface area 8 cm ² of the layer minute columns the resulting substrate surface in Example 16 is bristled is exposed An antifouling test was conducted using Specifically, each of these samples was immersed in 80 mL of an aqueous methylene blue solution adjusted to a concentration of about 10 μmol / L, and the influence of the decrease in concentration due to initial adsorption became negligible. Matsushita Electric Industrial Co., Ltd. Visible light was irradiated with a fluorescent lamp with a UV cut filter manufactured, and the absorbance of the methylene blue aqueous solution at a wavelength of 660 nm was measured with a water quality inspection apparatus DR / 2400 manufactured by HACH at every predetermined irradiation time. The result was as shown in FIG.

  From FIG. 14, the member in which the layer with the fine pillars exposed on the surface of the substrate obtained in Example 16 is exposed to methylene blue as compared with the titanium plate having the titanium oxide film obtained in Comparative Example 4. It can be seen that the decomposition speed of is high and the antifouling effect is high.

Test Example 16 (Crystal structure and bonding state)
As a result of performing X-ray analysis (XRD) on the sample obtained from the fine column of the member in which the layer with the fine column grown on the substrate surface obtained in Example 15 is exposed, it has a rutile crystal structure. It has been found.

Further, with respect to the fine column portion of the member in which the layer with the fine columns grown on the surface of the substrate obtained in Example 15 is exposed, an X-ray photoelectron spectrometer (XPS) is used to accelerate voltage: 10 kV, target: Al was used for Ar sputtering for 2700 seconds, and analysis was started. If this sputtering rate is 0.64 Å / s corresponding to the SiO ₂ film, the depth is about 173 nm. The result of the XPS analysis was as shown in FIG. The highest peak appears when the binding energy is 284.6 eV. This is judged to be a C—H (C) bond commonly found in Cls analysis. The next highest peak is seen when the binding energy is 281.6 eV. Since the bond energy of the Ti—C bond is 281.6 eV, it is determined that C is doped as a Ti—C bond in the fine column of Example 15. As a result of XPS analysis at 14 points at different heights of the fine columns, similar peaks appeared in the vicinity of 281.6 eV at all points.

[Example 19]
A disc having a diameter of 32 mm and a thickness of 0.3 mm was used as a test piece, and the surface thereof was heated by an acetylene combustion flame so that the surface temperature was maintained at about 1150 ° C. About the 1st test piece, the heating was stopped at the time of the heating time of 120 seconds, and it stood to cool. About the 2nd test piece, the heating was stopped at the time of 180 second and it stood to cool. The third test piece was heated for 480 seconds, and immediately the surface to which the flame was applied was brought into contact with the flat surface of a 30 mm thick stainless steel block and cooled. By this cooling, a thin film was peeled off from the surface of the titanium plate, and a member in which a layer in which fine columns made of white titanium oxide were erected was exposed. With respect to these three test pieces, a hole of 3 μm × 12 μm and a depth of 10 μm was dug on the surface of the test piece using a FIB-SEM apparatus SMI8400SE manufactured by Seiko Instruments Inc., and the side and bottom surfaces thereof were observed with a SEM apparatus VE7800 manufactured by Keyence Corporation. Went. The SEM photograph of the test piece after 120 seconds is FIG. 16, the SEM photograph of the test piece after 180 seconds is FIG. 17, and the SEM photograph of the test piece after 480 seconds is FIG. In FIG. 17 after 180 seconds, signs of a fine column structure begin to appear in the lower part of the film, and it is considered that by continuing the flame treatment, the fine column is elongated and a fine column structure as intended in the present invention is formed. .

[Concrete example]
Below, the specific example of the components for vehicles formed as invention of this invention is demonstrated.

  The vehicle parts of the present invention include various parts constituting the vehicle, such as driving parts for automobiles, motorcycles, bicycles, bodies, decorations, exteriors, interiors, and the like. In particular, the parts for which the durability (high hardness, scratch resistance, abrasion resistance, chemical resistance, heat resistance) and excellent photocatalytic effect are required depending on the installation site and function are the vehicle parts of the present invention. included.

  Specifically, as vehicle parts of the present invention, for example, exhaust pipe caps, mufflers, wheel caps, optical cylinder heads, connecting rods, engine valves, brake pads, sprockets, various bearings of vehicles such as automobiles, motorcycles and bicycles, Tire housing molding, stabilizer, outrigger, steps provided at the bottom of the door, front grille, wiper metal fittings, roof carrier, roof molding, under molding, cool panel, fish transport van, truck van, van air purifier , Optical oil element unit, optical air intake element, and the like.

  The exhaust pipe cap is a cap used for an exhaust gas outlet portion of the exhaust pipe. Since the exhaust gas outlet portion of the exhaust pipe is easily contaminated by soot, it is necessary to clean it frequently. For this reason, if the exhaust pipe cap is formed of the above-described vehicle component material, an antifouling effect can be obtained, so that a clean state can be maintained without frequent cleaning. It becomes like this. Similarly, by using the above-mentioned member inside the muffler, it is possible to suppress the adhesion of soot to this part, and if this member is used on the outer peripheral surface of the muffler, scratches and dirt on the outer surface of the muffler can be prevented. It can be made difficult to stick.

  The wheel cap is a disk-shaped canopy that is attached to an outer mounting portion of a vehicle wheel. There is a role to protect the tightening bolts, and it also serves as a decoration. Also called a wheel cover. Wheel caps are easily soiled by wear soot from brake pads and brake shoes. For this reason, if the wheel cap is formed of the above-described vehicle component material, an antifouling effect can be obtained, so that a clean state can be maintained and a decorative effect can also be maintained. become.

  The optical cylinder head is a head cover provided on the top of the engine, and since decorativeness is important, antifouling properties are required. If this optical cylinder head is formed of the above-described vehicle component material, an antifouling effect can be obtained, so that a clean state can be maintained and a decorative effect can also be maintained.

  The connecting rod is a power transmission component used inside the engine, and is a connecting rod having a function of connecting the crankshaft and the piston. The engine valve is a valve that opens and closes in order to feed fuel and air into the cylinder and to discharge exhaust gas from the cylinder. The brake pads (including brake shoes) are for converting the rotational motion of the drive wheels into thermal energy by pinching or abutting a friction surface such as a disk connected to the drive wheels. A sprocket is a gear that transmits power using a chain or belt. A bearing is a part used to efficiently rotate a rotating part of a machine, and is incorporated in most machines with a rotational motion. Since these parts slide with other parts at high speed, the durability can be improved by forming them with the above-described members.

  The tire housing molding is an ornament attached around the portion where the tire is attached, and the emphasis is on decoration. If this tire housing molding is formed of the above-described vehicle component material, an antifouling effect can be obtained, so that a clean state can be maintained and a decorative effect can also be maintained. Become.

  The stabilizer is a part that suppresses the tilting of the vehicle body due to centrifugal force when the automobile is curved, and is also referred to as an anti-roll bar or a sway bar. Stabilizers, for example, connect suspension arms provided on the left and right sides of an automobile with U-shaped spring steel, and use the repulsion of the spring steel torsion that occurs when the automobile tilts to control the inclination of the automobile. Suppress. If this stabilizer is formed of the above-described vehicle component material, the stabilizer can be maintained in a clean state, and the above-described durability and excellent photocatalytic effect can be obtained.

  An outrigger means a lateral leg (for example, two or four) that is used by being pulled out from a chassis, for example, and is often mounted on a large vehicle such as a fire truck or a camper. The outrigger is used to prevent the automobile from shaking when the vehicle is stopped. If the outrigger is formed of the above-described vehicle component material, the outrigger can be maintained in a clean state, and the above-described durability and excellent photocatalytic effect can be obtained.

  The step provided at the lower part of the door is used as a scaffold when getting on or off. This step is provided in a car having a relatively high seat such as a wagon car or a truck. The steps provided in the automobile are darkened due to dirt caused by rebound from the road and dirt of exhaust gas, particularly when provided outside the vehicle. If this step is formed of the above-described vehicle component material, the step can be maintained in a clean state, and the above-described durability and excellent photocatalytic effect can be obtained.

  The front grill means an air intake for introducing outside air into the engine room. Due to the nature of taking in air, the front grille is contaminated with dirt from rebounding from the road, dirt from exhaust gas, dirt from dead carcasses stuck on the road. Dirt from sticky insect carcasses becomes difficult to remove when dried. If the front grill is formed of the above-described vehicle component material, the front grill can be maintained in a clean state, and the above-described durability and excellent photocatalytic effect can be obtained.

  The wiper includes a wiper motor, a wiper link, a wiper arm, and a wiper blade. The wiper blade wipes rain and dust on the glass surface by reciprocating rotational movement. As with the front grill, various types of dirt are likely to adhere to the metal fitting that holds the wiper blade in the wiper. If the metal fitting for holding the wiper blade is formed of the above-described vehicle component material, the metal fitting can be maintained in a clean state, and the above-described durability and excellent photocatalytic effect can be obtained.

  The roof carrier is a luggage storage installed on the roof of an automobile. The roof carrier includes a box type and a fence type. If this roof carrier is formed of the above-described vehicle component material, the roof carrier can be maintained in a clean state, and the above-described durability and excellent photocatalytic effect can be obtained.

  The roof molding is a decoration that is attached to the left and right sides of the roof. It is not only used for decoration, but also serves to rectify the flow of rainwater, cover joints, protect hands and fingers, and hold down other parts. Fulfill. The roof molding is important for its decoration, and it is the main point of design. If this roof molding is formed of the above-described vehicle component material, the roof molding can be maintained in a clean state, and the above-described durability and excellent photocatalytic effect can be obtained.

  The under molding is a decorative plate disposed around the lower part of the automobile body such as a door, and has a function of protecting the lower side of the automobile body from a stepping stone from the road. If the under molding is formed of the above-described vehicle component material, the under molding can be maintained in a clean state, and the hardness is increased, so that the protection performance is improved. Furthermore, the durability and the excellent photocatalytic effect described above can be obtained.

  The cool panel is a van truck exterior plate used as a cold car or a freezer car. If this cool panel is formed of the above-mentioned vehicle parts material, a water film is always formed on the cool panel due to its super-hydrophilic performance, so that an antifouling effect is obtained and the surface temperature is reduced due to latent heat of vaporization. Can be encouraged.

  The fish transport van is a rear cargo room equipped with a water tank into which seafood is put together with seawater and fresh water. If the inside of the water tank that constitutes this fish transport van is formed of the above-mentioned parts for vehicles, and the ultraviolet light is irradiated to the inside of the water tank by the ultraviolet irradiation unit installed in the van, the water tank that constitutes the fish transport van Can be kept clean. Therefore, even when the seafood is transported alive, it is possible to prevent the freshness during transport and the transmission of disease. As described above, since the ultraviolet ray is irradiated to the inside of the water tank having the carbon-doped titanium oxide film by the ultraviolet ray irradiation unit installed in the van, the fish transport van can be provided with self-purifying performance. become.

  The truck van is the rear cargo compartment that makes up the truck. If this truck van is formed of the above-described vehicle component material, the van can be maintained in a clean state, and can be used for a long time with excellent corrosion resistance and toughness. Become. The chassis and chassis are generally discarded in 5 to 7 years, but the van can be used repeatedly for a long time, so the cost burden when purchasing a new vehicle is reduced. In addition, since the life of the van is extended, the load on the environment can be greatly reduced. Further, if the truck van is formed of the above-described vehicle component material, a cooling effect and antifouling performance can be imparted.

  The van air purifier is an air purifier installed in a rear cargo room constituting a truck. The purification method may be a filtration method or an electrostatic method. In this example, the entire inner surface of the rear cargo compartment is formed of the above-described vehicle component material, and a filter made of titanium metal having a carbon-doped titanium oxide film is used as a filter for a van air purifier. By irradiating the inside of the rear luggage compartment and the filter of the vane air purifier with the ultraviolet ray irradiation unit installed in the van, the vane air purifier filter is purified by the photocatalytic effect while the vane air purifier filter is purified. The purifier can clean the air in the rear cargo compartment.

  Further, the vehicle component of the present invention may be a light oil element unit or a light air intake element described below.

  The optical oil element unit includes an oil element unit (lubricating oil purifier) incorporating a filter formed of the above-described vehicle component material, and an ultraviolet irradiation unit that irradiates the filter with ultraviolet rays. In the conventional oil element unit, when a filter for filtering dirt of engine oil is dirty, the built-in filter is replaced. For this reason, the environmental problem accompanying disposal of the filter has occurred. On the other hand, in the optical oil element unit of the present example described above, a filter made of metal titanium having a carbon-doped titanium oxide film is used, and the filter is irradiated with ultraviolet rays by the ultraviolet irradiation unit, so that the filter is caused by the photocatalytic effect. It will be purified. Therefore, the replacement life of the filter can be greatly extended, the filter can be used for a long time, and the load on the environment can be greatly reduced. Further, in the above-described optical oil element unit, if the filter life is adjusted to be longer than the life of the automobile (for example, the amount of ultraviolet ray irradiation by the ultraviolet ray irradiation unit is adjusted), there is no need to replace the filter. A “self-contained” oil element unit can be realized.

  The optical air intake element includes an air intake element incorporating a filter formed of the above-described vehicle component material, and an ultraviolet irradiation unit that irradiates the filter with ultraviolet rays. In a conventional air intake element, when a filter for purifying air taken in from the outside for sending the engine to the engine becomes dirty, the built-in filter is replaced. For this reason, the environmental problem accompanying disposal of the filter has occurred. On the other hand, in the optical air intake element of the above-described example, a filter made of titanium metal having a carbon-doped titanium oxide film is used, and the filter is irradiated with ultraviolet rays by an ultraviolet irradiation unit. It will be purified. Therefore, the replacement life of the filter can be greatly extended, the filter can be used for a long time, and the load on the environment can be greatly reduced. Further, in the above optical air intake element, if the filter is adjusted so that the life of the filter is equal to or longer than the life of the automobile (for example, adjusting the amount of ultraviolet irradiation by the ultraviolet irradiation unit), the replacement of the filter is not required at all. A “self-contained” air intake element can be realized.

  In the present invention, at least a part of the vehicle component as described above has a layer made of titanium oxide or titanium alloy oxide in which at least a surface layer is carbon-doped, and the carbon is doped in a Ti-C bond state. Has been.

  Alternatively, in the present invention, at least a part of the vehicle component as described above has a plurality of protrusions made of titanium oxide or titanium alloy oxide on at least a part of the surface, and the protrusions are carbon-doped. Has been.

  By being configured in this way, it is possible to make the vehicle component excellent in durability, and in particular, the vehicle component that has an effect of antifouling and prevents the decorative property from being impaired, and the replacement life. It is possible to provide vehicular parts and the like that are greatly extended.

  The vehicle parts of the present invention are not limited to those described above, and may be other parts such as a retrofouling antifouling plate, a large antifouling wheel cap, and a sanitary return box.

It is a figure which shows the result of the film hardness test of Test Example 1. 10 is a diagram showing the results of XPS analysis in Test Example 5. FIG. It is a figure which shows the wavelength response of the photocurrent density of Test Example 6. It is a figure which shows the test result of the light energy conversion efficiency of Test Example 7. It is a figure which shows the result of the deodorizing test of Test Example 8. 10 is a photograph showing the results of an antifouling test in Test Example 9. It is a figure which shows the result of Test Example 11. It is a photograph which shows the light transmission state of the carbon dope titanium oxide layer obtained in Example 11 and 12. 6 is a photograph showing the surface state of the carbon-doped titanium oxide layer obtained in Example 11. FIG. It is a microscope picture which shows the state of the components for vehicles obtained in Example 13. It is a microscope picture which shows the state of the thin film side surface of the small piece member 3 which has exposed many fine narrow protrusions which consist of white titanium oxide on a thin film, and the fine pillar standing on a protrusion part. A large number of continuous narrow-width projections made of white titanium oxide on the thin film and a large number of continuous narrow-width projections of the small piece member 3 in which fine columns standing on the projection are exposed, and the projections It is the microscope picture which shows the state of the surface of the side where the fine pillar which stands in the side is exposed. It is a microscope picture which shows the state of the layer 2 in which the micro pillar which consists of white titanium oxide stands. It is a graph which shows the result of Test Example 15 (antifouling test). It is a graph which shows the result of Test Example 16 (crystal structure and bonding state). It is a SEM photograph after a heating time of 120 seconds in Example 19. It is a SEM photograph after a heating time of 180 seconds in Example 19. It is a SEM photograph after the heating time of 480 seconds in Example 19.

1 Surface of substrate 2 Fine column 3 Thin film

Claims (4)

A vehicle component that constitutes a part of a vehicle such as an automobile, a motorcycle, or a bicycle,
The surface of the substrate made of titanium or a titanium alloy is heat-treated for a heating time of 400 seconds or less under the condition that the surface temperature of the substrate is 900 to 1500 ° C. using a combustion flame of a gas containing hydrocarbon as a main component, By performing heat treatment for 400 seconds or less under the condition that the surface temperature of the substrate is 900 to 1500 ° C. in a combustion gas atmosphere of a gas containing hydrocarbon as a main component, at least a part of the surface layer is made of carbon. A vehicle component comprising a carbon-doped titanium oxide layer made of titanium oxide or titanium alloy oxide doped in a Ti-C bond state.   The vehicle component according to claim 1, wherein the layer made of carbon-doped titanium oxide or titanium alloy oxide contains 0.3 to 15 at% carbon.   The surface layer of carbon-doped titanium oxide or titanium alloy oxide is bonded to the underlying substrate of titanium or titanium alloy via a Ti-C bond. 2. Vehicle parts according to 2.   Exhaust pipe caps, mufflers, wheel caps, light cylinder heads, connecting rods, engine valves, brake pads, sprockets, various bearings, tire housing moldings, stabilizers, outriggers, steps under the doors of vehicles such as automobiles, motorcycles and bicycles , Front grille, metal parts constituting wiper, roof carrier, roof molding, under molding, cool panel, fish transport van, truck van, van air purifier, optical oil element unit, optical air intake element The vehicle component according to claim 1, 2 or 3.