KR20090087124A - Ceramic for decorative part, decorative part for watch, decorative part for portable device, and portable device - Google Patents

Abstract

Disclosed is a ceramic for decorative parts, which has a composition containing a main component composed of titanium nitride represented by TiNx (0.8 <= x <= 0.96) and a sub-component composed of nickel, while further containing a first additional component composed of at least one substance selected from the group consisting of vanadium nitride, niobium nitride, tantalum nitride, molybdenum carbide, niobium carbide, tungsten carbide and tantalum carbide, and a second additional component composed of titanium oxide. ® KIPO & WIPO 2009

Description

Ceramic for decorative parts, decorative parts for watches, decorative parts for mobile devices and mobile devices {CERAMIC FOR DECORATIVE PART, DECORATIVE PART FOR WATCH, DECORATIVE PART FOR PORTABLE DEVICE, AND PORTABLE DEVICE}

The present invention is decorative ceramics for decorative parts, decorative parts for clocks, decorative parts for mobile devices, decorative parts for building materials, ceramics for decorative parts used for religious crafts, decorative parts for living parts, decorative parts for clocks, decoration for mobile devices It relates to parts and portable devices. Here, the decorative part for watches means, for example, a case for a watch, a part used for a band node, and the like to produce a beautiful color tone. In addition, decorative parts for mobile devices are mobile communication devices and terminals (such as mobile phones, PHS, and broadcast receivers) or mobile information devices and terminals (cameras, portable AV devices, calculators, portable computers, PDAs, electronic dictionaries, etc.). It refers to operation buttons, such as a number key of a portable device and various input keys, a case, a frame-shaped part which fixes a display, etc.

Background Art [0002] Conventionally, metal materials in which gold, alloys, or various metals are plated have been used for gold-colored decorative parts and decorative parts for jewelry because of color tone and corrosion resistance.

However, all of the gold, its alloys, or the plated metal materials have a problem that the surface is scratched or deformed by contact with a hard material because the hardness is low.

Recently, to solve this problem, various ceramics for decorative parts have been proposed.

For example, Patent Literature 1 and Patent Literature 2 disclose ceramics for decorative parts in which a golden hue is maintained by a hard phase mainly composed of TiN _Z (0.6 ≦ _Z ≦ 0.93). As the value of Z is smaller than the value of the stoichiometric composition, it changes from golden color to light golden color. In addition, the addition of golden-colored TiO, ZrN, HfN, VN, NbN, TaN, CrN, Cr ₂ N, TaC, and NbC is said to facilitate color tone control from pale golden to deep golden.

In addition, Patent Document 3 discloses 45 to 75% by mass of titanium nitride as a hard phase, 7.5 to 25% by mass of titanium carbide, and 1 to 10% by mass of chromium as the total amount of carbide as the binding phase, and molybdenum as the total amount of carbide. The brightness index (L *) is 65-69 in the display in the CIE1976L * a * b * color space obtained from a colorimeter, while containing 0.1-5 mass% and 5-20 mass% of nickel in the whole quantity in conversion. In addition, the ceramic for decorative parts which made chromaticness index (a *, b *) 4-9, 5-16 are disclosed, respectively.

Patent Document 1: Japanese Patent Publication No. 4-47020

Patent Document 2: Japanese Patent Application Laid-Open No. 4-47021

Patent Document 3: Japanese Unexamined Patent Publication No. 2003-13154

Patent Literature 1 and Patent Literature 2 show that the addition of TiO, ZrN, HfN, VN, NbN, TaN, CrN, Cr ₂ N, TaC, and NbC enables color tone control from pale golden to deep golden. It is. However, more glossy and beautifully colored ceramics are desired.

In patent document 3, since it is comprised by the sintered compact itself, the film is not peeled off and although it is equipped with the outstanding corrosion resistance, it is the color tone which has silver and purple to pink together, and was not a golden hue.

The ceramic for decorative component of the present invention is composed of titanium nitride having a composition formula of TiN _x (0.8 ≦ _x ≦ 0.96) as a main component, nickel as a minor component, and vanadium nitride, niobium nitride, tantalum nitride, molybdenum carbide, niobium carbide, and carbide. It is characterized by having the decorative surface containing the 1st addition component which consists of at least 1 sort (s) chosen from tungsten and tantalum carbide, and the 2nd addition component which consists of titanium oxide.

Further, the decorative part for watches and the decorative part for portable devices of the present invention are each made of the ceramic for the decorative part.

The portable device of the present invention also includes a decorative component for the mobile device.

(Effects of the Invention)

According to the ceramic for decorative component of this invention, since the reflectance of the light in a decorative surface is high, glossiness increases. As a result, the consumer can obtain a sense of quality and aesthetic satisfaction.

In addition, according to the decorative part for watches and decorative parts for portable devices of the present invention, since the mental comfort through the sense of luxury or aesthetic satisfaction can be obtained, it can be preferably used for watches and portable devices requiring a function and visual aesthetics. .

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining an example of the watch case which is the clock decorative part of this invention, (a) is a perspective view which looked at the watch case from the surface side, (b) is a back side of the watch case of (a) It is a perspective view seen from the side.

It is a perspective view which shows another example of the watch case which is a decorative component for watch of this invention.

It is a schematic diagram which shows an example of the watch band which is a decorative component for watch of this invention.

4 is a perspective view showing an example of a mobile telephone using the ornament for portable devices of the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, the best form (henceforth this embodiment) for implementing this invention is demonstrated.

The ceramic for decorative parts of the present embodiment is at least one selected from titanium nitride as a main component, nickel as a minor component, and vanadium nitride, niobium nitride, tantalum nitride, molybdenum carbide, niobium carbide, tungsten carbide, and tantalum carbide. It is a sintered compact which has a decorative surface containing the 1st addition component which consists of and the 2nd addition component which consists of titanium oxide.

Here, a main component means the component which occupies 50 mass% or more among the components which comprise the ceramic for decorative components, and a subcomponent means a component of less than 50 mass%. However, in this embodiment, the mass ratio of the subcomponent and 1st addition component may be the same.

This is because titanium nitride, which is a main component, has good golden color as an ornament and high mechanical properties such as strength and hardness. Moreover, in order to have this golden color, it is preferable to contain 70 mass% or more of titanium nitride.

Nickel, which is a minor component, acts as a binder for binding each crystal of titanium nitride and the additive component, which is the main component, and mainly forms a grain boundary phase.

At least one selected from the first additive component vanadium nitride, niobium nitride, tantalum nitride, molybdenum carbide, niobium carbide, tungsten carbide and tantalum carbide all act as a color tone adjusting agent, and vanadium nitride, niobium nitride and tantalum nitride are titanium nitride Niobium, tungsten carbide and tantalum carbide are molten in nickel and are dissolved in nickel.

Titanium oxide, which is the second additive component, is mixed with the raw material powder during the mixing and grinding, and most of it is oxidized during firing of carbon, which acts to increase the chromaticity index (a *), and is discharged as a gas. In addition, the remainder acts as a titanium oxide of the composition formula TiO _{2 -y} (0 <y <2) having a black color with a part of the oxygen deficient, and controlling the chromaticness index (a *). The carbon is a component constituting a binder such as paraffin wax, and part of the carbon is bonded to oxygen constituting titanium oxide.

Here, the value of y of the composition formula TiO _{2 -y} (0 <y <2) can be obtained from the intensity ratio of titanium (Ti) and oxygen (O) by, for example, fluorescence X-ray analysis.

In addition, the arithmetic mean height Ra of the decorative surface at least is 0.03 micrometer or less. And the brightness index (L *) in CIE1976L * a * b * color space of the said decorative surface is 72 or more and 84 or less, and chromaticness index (a *, b *) is 3 or more, 9 or less, 27 or more, respectively. It becomes 36 or less.

As a result, luxury, aesthetic satisfaction, and mental comfort are provided to the consumer who demands decorative values, and also a beautiful golden color tone. The arithmetic mean height Ra of the decorative surface affects the reflectance of the light. By setting the arithmetic mean height Ra to 0.03 µm or less, the reflectance of light is increased, so that the value of the brightness index L * can be increased.

Since the above-mentioned wavelength of light is a collection of visible light having 380 to 780 nm, the arithmetic mean height Ra is 0.03 µm or less, which causes visible light to be spectroscopy, and reduces the reflection of light in the wavelength region of 450 to 500 nm showing blue color. It acts so that the reflection of the light of the wavelength range 570-590 nm which shows yellow may increase. That is, beautiful golden color can be exhibited by making arithmetic mean height Ra into 0.03 micrometer or less.

In particular, it is preferable that the reflectance of the decorative surface with respect to the light of wavelength range 570-700 nm is 50% or more.

Here, the arithmetic mean height Ra is translated into JIS B 0601-2001 (this standard is ISO 4287, Geometrical Product Specifications (GPS) -Surface texture: Profile method-Terms, definitions and surface texture parameters It is good to measure in accordance with the Japanese Industrial Standards which were created without changing the technical content and the form of a standard table. When measuring length and cut-off value are 5 mm and 0.8 mm, respectively, and it is measured using a stylus type surface roughness meter, the tip of a stylus tip is attached to the decorative surface of the ceramic for disk-shaped decorative component of diameter 10-20 mm, for example. What is necessary is just to make contact with the needle of a radius of 2 micrometers, and the scanning speed of a needle may be 0.5 mm / sec. Arithmetic mean height Ra is the average value of five arithmetic mean heights Ra obtained by this measurement.

In addition, the composition constituting the ceramic for the decorative component is as described above, and the brightness index L * in the CIE1976L * a * b * color space of the decorative surface is set to 72 or more and 84 or less by the manufacturing method described below. The chromaticity index (a *, b *) is set to 3 or more and 9 or less and 27 or more and 36 or less, respectively. As a result, the tones produce a superior synergy, resulting in a sense of luxury and aesthetic satisfaction, and as a result, the consumer can gain mental comfort through vision.

Here, the brightness index L * is an index indicating the contrast of the color tone. If the value of the brightness index L * is large, the color tone is bright, and if the value of the brightness index L * is small, the color tone is dark. The value of the brightness index L * was made 72 or more and 84 or less because it is the brightness which is suitable for a golden hue in this range. In particular, it is preferable that the value of the brightness index L * is 72 or more and 79 or less.

The chromaticity index (a *) is an index indicating the degree of red to green color of the hue. If the value of the chromaticity index (a *) is large in the positive direction, the hue becomes red. If the absolute value is small, the hue is It becomes a dull hue lacking vividness. On the other hand, when the value of the chromaticness index a * is large in the negative direction, the color tone becomes green. The reason why the chromaticity index (a *) is set to 3 or more and 9 or less is that redness can be suppressed without deteriorating the vividness of the color tone within this range.

The chromaticity index (b *) is an index indicating the degree of hue from yellow to blue. If the value of the chromaticity index (b *) is large in the plus direction, the hue becomes yellow, and if the absolute value is small, the hue is It becomes a dull hue lacking vividness. On the other hand, when the value of the chromaticness index b * is large in the negative direction, the color tone becomes blue. The value of the chromaticness index (b *) was made into 27 or more and 36 or less because it is possible to produce golden color in this range, without losing the vividness of a hue.

Here, the decorative surface in the ceramic for decorative components of this embodiment refers to the surface where the decorative value of a decorative component is calculated | required, and does not refer to all surfaces. For example, when using the ceramic for decorative parts of this embodiment for a watch case, the outer surface of this watch case is a decoration surface because it is an object of appreciation and decorative value is calculated | required.

The value of the brightness index (L *) and chromaticity index (a *, b *) in the CIE1976L * a * b * color space of such a decorative surface was JIS Z 8722-2000 (this standard was Based on the published ISO / DIS 7724 Paints and varnishes-Part1: Principles, Part2: Color measurement, the corresponding parts of the Japanese Industrial Standards are written without changing the technical contents, but are not specified in the corresponding international standards. [6. 4 and 6. 3.2b)] are added as Japanese Industrial Standards. For example, using a spectrophotometer (KONICA MINOLTA HOLDINGS CORPORATION CM-3700d, etc.), the light source was measured using the CIE standard light source D65, the viewing angle was set at 10 °, and the measurement range was set at 5 mm x 7 mm, respectively. can do.

The color tone of the ceramic for decorative parts of the present embodiment is affected by the value of the atomic number x of the composition formula TiN _x . As the number of atoms x decreases, the color tone changes from golden color to light golden color. As the number of atoms x becomes larger, the color tone becomes dull dark golden color. From this viewpoint, the value of the atomic number x of the composition formula TiN _x is preferably 0.8 or more and 0.96 or less.

Since titanium nitride can be replaced with or react with oxygen and carbon contained in a degreasing or sintering atmosphere to become titanium oxynitride (TiCNO), the value of atomic number x can be determined using an oxygen / nitrogen analyzer and a carbon analyzer. . Specifically, after measuring the ratio of oxygen, nitrogen, and carbon to 100% by mass of titanium nitride by these analyzers, the value obtained by subtracting the sum of the proportions of these elements from 100% by mass of titanium nitride was 47.9 atomic masses of titanium. By dividing, the number-of-moles of titanium in composition formula TiN _x are calculated | required. In addition, the number-of-moles of nitrogen in composition formula TiNx are _{calculated | required} by dividing the ratio of nitrogen by the atomic weight of nitrogen. The value of nitrogen ratio when the number-of-moles of titanium calculated | required is converted into 1 is the value of atomic number x calculated | required.

Moreover, it is preferable that the ceramic for decorative components of this embodiment contains chromium as a 3rd additive component. This is because chromium combines with oxygen in the air to form a dense oxide film on the decorative surface, thereby improving corrosion resistance and maintaining long-term quality, aesthetic satisfaction and mental comfort.

In particular, the ceramics for decorative parts of the present embodiment include 7% by mass or more and 14.5% by mass or less of nickel as the minor component, vanadium nitride, niobium nitride, tantalum nitride, molybdenum carbide, niobium carbide, tungsten carbide, and carbide as the first additive component. It is more preferable to contain at least 1 type of tantalum in the ratio of 2.5 mass% or more and 10 mass% or less.

Nickel is made 7 mass% or more and 14.5 mass% or less because decorativeness is good and it can fully bond the crystal | crystallization of a subcomponent and the titanium nitride crystal. In particular, when this decorative component ceramic adheres to a body including a watch case, a band node, etc., it is more preferable that they are 7 mass% or more and 9 mass% or less.

The amount of the first additive component of 2.5% by mass or more and 10% by mass or less acts as a color tone adjusting agent for vanadium nitride, niobium nitride, and tantalum nitride among the first additive components, and the nitride is dissolved in titanium nitride so that the chromaticity index ( This is because there is an effect of increasing the value of b *). The value of the chromaticity index (b *) can be set to 30 or more, and the sintering property is also improved.

It is preferable to make vanadium nitride into 2.5 mass% or more and 6 mass% or less in the said nitride. This is because vanadium nitride can be easily dissolved in titanium nitride at this ratio.

Molybdenum carbide, niobium carbide, tungsten carbide, and tantalum carbide also act as color tone adjusters like nitrides, but unlike the above nitrides, they are not dissolved in titanium nitride but are melted in nickel to increase the value of the chromatic index (b *). There is action.

Content of chromium which is a 3rd addition component affects corrosion resistance and a clarity. If the content of chromium is large, the elution of nickel is suppressed, so that the corrosion resistance is improved, but the chromaticness index (a *, b *) indicating the sharpness is lowered. When the content of chromium is small, the corrosion resistance is low, but the chromaticness index (a *, b *) is high. In the ceramic for decorative parts of this embodiment, it is preferable to contain chromium in the ratio of 1.5 mass% or more and 6.5 mass% or less. By setting it as this range, corrosion resistance and clarity can be combined.

Moreover, as for molybdenum carbide, niobium carbide, tungsten carbide, and a tantalum carbide, it is more preferable that the sum total of content is 3 mass% or more and 8 mass% or less.

Since these first additive components act to suppress grain growth, the grain boundaries are increased, and the incident light is strongly affected by the specular reflection caused by the crystals forming the decorative surface and the diffuse reflection by the grain boundaries. The brightness index (L *) and chromaticity index (b *) of are high. In addition, the color tone produces an excellent synergistic effect, thereby increasing the glossiness of the color tone, thereby obtaining more sense of quality and aesthetic satisfaction. As a result, mental comfort is gained through vision.

Here, the reflection generally consists of specular reflection and diffuse reflection, and the specular reflection in the present embodiment is when the light is reflected after entering the decorative surface (microscopic crystal forming the decorative surface) which is mirror surface. It refers to the reflection whose incident angle and reflection angle are the same. In addition, the diffuse reflection refers to the reflection toward the outside after light enters the grain boundary and repeats random reflection.

However, surface roughness can be adjusted by barrel polishing which mentions the crystal | crystallization which forms a decorative surface mentioned later. It is preferable to make surface roughness of the crystal plane measured by atomic force microscope into 1-2 nm by arithmetic mean height Ra. This is because in this range, the reflection on the crystal plane tends to partially change from specular reflection to diffuse reflection, and the chromaticity index b * on the decorative surface can be 32 or more.

As a 1st addition component, it is more preferable to contain at least any 1 type of vanadium nitride, niobium nitride, and tantalum nitride, and at least 1 type of molybdenum carbide, niobium carbide, tungsten carbide, and tantalum carbide. Nitride acts to increase the value of the chromaticity index (b *) by being dissolved in titanium nitride, while carbides are melted inside the nickel to increase the brightness index (L *) and the chromaticity index (b *). can do.

In the ceramic for decorative parts of the present embodiment, nickel is reacted with chromium to generate a nickel chromium compound when the secondary component nickel forms a grain boundary phase in which titanium nitride is bonded in a state of enclosing chromium as the third additive component. This ionization does not flow out, and mechanical properties and corrosion resistance can be improved.

Each content of a main component, a subcomponent, a 1st addition component, and a 3rd addition component can be measured using a fluorescence X-ray analysis (XRF) method. Specifically, mixed powders having different proportions of titanium nitride, nickel, vanadium nitride, and chromium are previously molded by dry pressure molding to obtain a standard sample.

Subsequently, each of these standard samples is irradiated with X-rays to detect the intensity of the metal elements constituting each component from the fluorescent X-rays emitted from the standard samples. From these strengths, the strength ratios of titanium and nickel, the strength ratios of titanium and vanadium, and the strength ratios of titanium and chromium are obtained, respectively. A calibration curve with the horizontal axis as the strength ratio and the vertical axis as the ratio is created by the least square method.

And the ceramic for decorative parts which a main component, a subcomponent, a 1st addition component, and a 3rd addition component which consists of a component similar to the said standard sample is grind | pulverized, and it is set as powder. Then, X-rays are irradiated to the sample molded by the dry pressure molding method to detect the strength of the metal elements constituting each component from the fluorescent X-rays emitted from the sample. The ratio of the strengths of titanium and vanadium and the strength ratios of titanium and chromium are obtained, respectively, and the ratios of the metal elements are obtained by plotting the strength ratios on a calibration curve prepared in advance. Here, about the ratio of titanium and vanadium, it converts into the ratio of titanium nitride and vanadium nitride whose composition formulas are TiN _x and VN, respectively. And content can be calculated | required by considering the ratio which combined titanium nitride, nickel, vanadium nitride, and chromium as 100 mass%, and calculating the ratio of these components.

When the third additive component is any one of niobium nitride, tantalum nitride, molybdenum carbide, niobium carbide, tungsten carbide, and tantalum carbide in addition to vanadium nitride, a standard sample is prepared by appropriate substitution, and a calibration curve is prepared by the method described above. What is necessary is to calculate content of each component by the method.

In addition, since titanium oxide which is a 2nd addition component is trace amount, what is necessary is just to analyze using a transmission electron microscope (TEM).

Here, the state in which nickel as a subcomponent contains chromium as a third additive component means a state in which chromium is surrounded by nickel, which forms a grain boundary without chromium contacting a crystal of titanium nitride. In this state, a scanning electron microscope It can confirm by contrasting the image of the decorative surface obtained with the image of the decorative surface which shows the distribution state of nickel and chromium detected by an energy dispersive (EDS) X-ray microanalyzer.

When the first additive component is niobium nitride or niobium carbide, it is preferable that nickel is precipitated as a nickel niobium compound, for example, NbNi ₃ , by combining niobium nitride or a portion of niobium carbide decomposed. The precipitation of NbNi ₃ increases the value of the brightness index (L *), and the value of the chromaticity index (a *) decreases, resulting in elegant brightness. Nickel niobium compounds such as NbNi ₃ can be detected by X-ray diffraction.

It is preferable that the open porosity in the decorative surface of the ceramic for decorative parts of this embodiment is 3% or less. Open pores on the decorative surface in particular affect the value of the brightness index (L *). When there are many open pores, the value of the brightness index L * becomes small, and when there are few open pores, the value of the brightness index L * becomes large. By setting the open porosity on the decorative surface to 3% or less, the value of the brightness index (L *) can be set to 75 or more and 79 or less, which becomes a more preferable color tone. Moreover, although it is preferable to make the value of the brightness index L * into 77 or more and 79 or less, in this case, it is preferable to make an open porosity into 2% or less.

Here, the open porosity on the decorative surface is 200 times magnification using a metal microscope, the image of the decorative surface is introduced with a CCD camera, and the image analysis device (LUZEX-FS, etc.) is made. Therefore, what is necessary is just to determine the open porosity in 4.5 * 10 <^-1> mm <^2> by measuring the measurement area of 1 view in an image as 2.25 * 10 <^-2> mm <^2> , and making the number of the field of view 20.

Moreover, the clock decorative component of this embodiment is comprised from the ceramic for decorative components of the said structure, It is characterized by the above-mentioned. Examples are watch cases and watch band segments. 1 shows an example of a watch case which is a decorative part for watches of the present embodiment, (a) is a perspective view seen from the front side of the watch case, and (b) is a perspective view seen from the back side of the watch case. 2 is a perspective view which shows another example of the watch case which is a decorative component for watch of this embodiment. 3 is a schematic diagram which shows an example of the structure of the watch band which is a decorative component for watch of this embodiment. When the same site | part is shown in these figures, the eastern arc was attached | subjected.

The watch case 10A shown in FIG. 1 has a recess 11 for receiving a movement (drive mechanism) (not shown) and a foot for fixing a watch band (not shown) for attaching a watch to the arm. (12), the recessed part (11) consists of a thin bottom part (13) and a thick trunk part (14).

The watch case 10B shown in FIG. 2 includes a hole 15 into which a movement (drive mechanism) (not shown) enters, and a watch band (not shown) for attaching a watch to an arm in the body portion 14. The foot part 12 which fixes) is provided.

The band node constituting the watch band 50 shown in FIG. 3 is arranged so as to sandwich the middle node 20 having the through-hole 21 into which the pin 40 is inserted, and the middle node 20, and the pin ( It consists of an outer section 30 having pin holes 31 to which both ends of 40 are mounted. In addition, the pin 40 is inserted into the through hole 21 of the middle node 20, and both ends of the inserted pin 40 are mounted in the pin hole 31 of the outer node 30, thereby forming the intermediate node 20. ) And the outer node 30 are sequentially connected to the watch band 50.

The band nodes constituting the watch cases 10A and 10B and the watch band 50 can obtain a sense of quality and aesthetic satisfaction as a watch by using the ceramic for decorative parts of the present embodiment, and through the eyes, You can get comfort.

Here, in the ceramic for decorative parts of this embodiment, the Vickers hardness Hv of a decorative surface becomes one of the factors which influence long-term reliability, and it is preferable that Vickers hardness Hv is 8 kPa or more. By setting the Vickers hardness (Hv) in this range, the decorative surface becomes less likely to be scratched, so that the decorative surface is not easily scratched even when contacted with a material having a high hardness such as dust made of glass or metal. Vickers hardness (Hv) of the decorative surface is JIS R 1610-2003 (this standard is ISO 14705: 2000, Fine Ceramics (advanced ceramics, advanced technical ceramics)-Test method for hardness of monolithic ceramics, published as the first edition in 2000) It is measured according to the Japanese Industrial Standards, which is produced by translating at room temperature and changing the technical content.

The fracture toughness affects the wear resistance of the decorative surface, and the higher the value, the better. The ceramics for decorative components of the present embodiment are preferably 4 MPa · m ^1/2 or more. This fracture toughness is measured based on the indenter indentation method (IF method) prescribed | regulated to JISR1607-1995.

When the ceramic for decorative parts is attached to and used on the body, it is preferable to be light, so that the apparent density of the ceramic for decorative parts of the present embodiment is preferably 6 g / cm 3 or less (excluding 0). This apparent density is measured based on JISR 1634-1998.

When the ceramic for decorative parts is an intermediate node 20 which is part of a watch band node, the tensile load is frequently applied to the intermediate node 20, so the tensile strength of the decorative component ceramic of the present embodiment is 196 N (Newton) or more. It is preferable. This tensile strength is obtained by inserting a super-economic pin (not shown) longer than the length of the through-hole 21 into the through-holes 21a and 21b of the intermediate section 20, and pulling the pin in the direction of detaching the pin. What is necessary is just to read the intensity | strength when the intermediate node 20 is destroyed with a load cell.

In addition, when the ceramic for decorative parts is a watch case or a watch band node, considering the influence on a movement (drive mechanism) (not shown), a ferromagnetic metal having a mass magnetization of 162 G · cm 3 / g or more, for example, For example, it is preferable that the ratio of cobalt (Co) is 0.1 mass% or less with respect to 100 mass% of ceramics for decorative components. The proportion of such ferromagnetic metals can be measured by ICP (Inductivity Coupled Plasma) emission spectrometry.

Next, the manufacturing method of the ceramic for decorative components of this embodiment is demonstrated.

In order to obtain the ceramic for a decorative component of the present embodiment, first, at least one of titanium nitride as a main component, nickel as a subcomponent, vanadium nitride as a first additive component, niobium nitride, and tantalum nitride as a first additive component and a second additive component Each powder of titanium oxide to be weighed and weighed in a predetermined amount is used as a raw material for the combination. More specifically, at least one of titanium nitride powder having an average particle diameter of 10 to 30 µm, nickel powder having an average particle diameter of 10 to 20 µm, and vanadium nitride, niobium nitride, and tantalum nitride having an average particle diameter of 2 to 10 µm A powder was prepared and weighed so that the titanium nitride powder was 70.5-90.0 mass%, the nickel powder was 7-14.5 mass%, the nitride powder was 2.5-10 mass%, and the titanium oxide powder was 0.5-5.0 mass%. May be pulverized and mixed.

In particular, when corrosion resistance is required, 67.5 to 84 mass% of titanium nitride powder, 10.0 to 13.0 mass% of nickel powder, 4.0 to 8.0 mass% of powder of nitride, 0.5 to 5.0 mass% of titanium oxide powder, What is necessary is just to weigh and grind | mix and mix so that the powder of chromium may be 1.5-6.5 mass%.

Here, it is necessary to increase the frequency of contact between the nickel powder and the chromium powder in order to form a grain boundary phase in which titanium nitride is bonded in a state where the nickel is surrounded by chromium, which is the third additive component. In order to raise this frequency, what is necessary is just to lengthen grinding | mixing time and mixing time, for example, what is necessary is just to make grinding time and mixing time into 150 hours or more.

In addition, although nitride was used as an additive component for the said combination raw material, at least any one of molybdenum, niobium, tungsten, and tantalum may be mixed with each powder of titanium nitride and nickel instead of nitride as a raw material of a combination. More specifically, titanium nitride powder having an average particle diameter of 10 to 30 µm, nickel powder having an average particle diameter of 10 to 20 µm, and at least one powder of molybdenum, niobium, tungsten, or tantalum having an average particle diameter of 1 to 50 µm To prepare a powder of titanium nitride of 70.5-90.0% by mass, nickel powder of 7-14.5% by mass, metal powder of 1-10% by mass, and titanium oxide powder of 0.5-5.0% by mass. What is necessary is to grind and mix.

In particular, when corrosion resistance is required, 67.5-84.0 mass% of titanium nitride powder, 10.0-13.0 mass% of nickel powder, 4.0-8.0 mass% of said metal powder, 1.5-6.5 mass% of chromium powder, and oxidation What is necessary is just to measure and grind | pulverize and mix so that the powder of titanium may be 0.5-5.0 mass%.

Here, the titanium oxide used to obtain the ceramic for decorative component of the present embodiment has good rutile type and anatase type crystal structure, but it is preferable to use rutile titanium oxide because it can be produced at a lower cost.

What is necessary is just to make grinding and mixing time into 150 hours or more in order to form the grain boundary phase which combines titanium nitride in the state which nickel contains chromium which is a 3rd addition component.

Although unavoidable impurities in this combination raw material include silicon, phosphorus, sulfur, manganese, iron, and the like. However, these are preferably 1% by mass or less because they may affect the color tone of the decorative surface.

In particular, in order to make the composition formula of titanium nitride constituting the ceramic for decorative parts TiN _x (0.8 ≦ _x ≦ 0.96), the titanium nitride powder may use the composition formula TiN _x (0.7 ≦ _x ≦ 0.9). In addition, from the viewpoint of color resistance with high wear resistance and decorative value, the purity of each powder is preferably 99% or more, and there is no problem even if the titanium nitride powder reacts with some nickel powder to produce a small amount of TiNi.

Subsequently, 2-propanol is added to the raw material as an organic solvent, for example, and mixed and milled using a mill. Then, a predetermined amount of paraffin wax is added as a binder, and a desired molding method, for example, dry press molding method and cold hydrostatic pressure It shape | molds to desired shapes, such as a disk, a flat plate, a torus, etc. by the pressure molding method, the extrusion molding method, etc. Then, if necessary, the molded product obtained in a non-oxidizing atmosphere such as a nitrogen atmosphere or an inert gas atmosphere is degreased, and then fired in at least one gas atmosphere selected from nitrogen and an inert gas or in a vacuum to obtain a sintered compact having a relative density of 95% or more. Get

Here, when at least one of molybdenum, niobium, tungsten and tantalum is used, part of the carbon constituting the paraffin wax reacts with molybdenum, tungsten and tantalum during firing to become molybdenum carbide, tungsten carbide and tantalum carbide, respectively. Is introduced inside.

And after lapping by using a lapping machine to the surface where the decorative value of the obtained sintered compact is requested | required, barrel polishing is performed and the surface of the sintered compact itself becomes a decorative surface which has a golden hue, and is used for the decorative component of this embodiment. A ceramic can be obtained.

Here, the pores appearing on the decorative surface preferably have a maximum diameter of 30 µm or less on the decorative surface, and by using this range, adhesion of various germs, foreign substances, contaminants, etc. into the pores can be reduced.

When the product shape of the ceramic for decorative parts is a complicated shape, it is previously formed into a block shape or a shape close to the product shape by dry pressure molding, cold hydrostatic pressure molding, extrusion molding, injection molding, etc., and then sintered and ground to a product shape. After processing, sequential lapping and barrel polishing may be performed, or it may be made into a product shape by the injection molding method from the beginning, and sequential lapping and barrel polishing may be performed after baking.

Here, in order to make arithmetic mean height Ra into 0.03 micrometer or less, what is necessary is just to supply a diamond paste with a small average particle diameter to a lapping machine made of tin, and to perform lapping, for example, to use a diamond paste with an average particle diameter of 1 micrometer or less. . In barrel polishing, green carborundum (GC) may be introduced into a rotating barrel polishing machine as a medium by using a rotating barrel polishing machine, and may be performed in a wet manner for 24 hours.

Here, heat-sintering the molded body in at least one gas atmosphere selected from nitrogen and an inert gas or in a vacuum means that the titanium nitride is oxidized when heat-sintered in an oxidizing atmosphere, the majority of which becomes titanium oxide represented by the compositional formula TiO ₂ . This is because the color tone of the entire ceramic for decoration parts is blurred by the influence of the white color tone that the titanium oxide is essentially provided.

When the dry pressure molding method is selected as the molding method, the molding pressure is preferably 49 to 196 MPa because the molding pressure affects the open porosity and the Vickers hardness (Hv) on the decorative surface. By forming the molding pressure of 49 MPa to 196 MPa, the life of the mold can be extended, and the open porosity of the decorative surface of the ceramic for decorative parts is 3% or less, and the Vickers hardness (Hv) is 8 kPa or more. You can do

When heat-sintering in vacuum and obtaining a ceramic for decorative components, it is preferable that the vacuum degree is 1.33 Pa or less. When the vacuum degree is set to 1.33 Pa or less, titanium nitride does not oxidize during firing, thereby obtaining a golden decorative component ceramic.

It is preferable to make heat-sintering temperature 1200-1800 degreeC. For this reason, heat sintering becomes enough and the relative density of a sintered compact can be 95% or more. In addition, crystals of the sintered compact do not cause abnormal grain growth, and the mechanical properties are improved, and the firing cost can be reduced. By setting the heating sintering temperature to 1200 to 1800 ° C, the open porosity can be 3% or less, and the firing cost can be lowered.

4 is a perspective view showing an example of a mobile phone using the decorative component for a mobile device of the present embodiment. It is preferable that the decorative component for portable devices of this embodiment consists of the ceramic for decorative components mentioned above, As an example, a mounting cover, an operation key, a decorative block, etc. which are shown in FIG. 4 are mentioned.

The mobile telephone 60 shown in FIG. 4 shows a state in which the second housing 62 is opened, and a display area for displaying various types of information on the surface of the second housing 62 facing the operation portion of the first housing 61. A display unit 72 made of an LCD (Liquid Crystal Display) or an ELD (Electro Luminescence Display) having a 71 and a speaker 73 for a call are provided.

On the surface of the first housing 61, an operation unit 74 made up of a plurality of operation keys capable of various pressing operations such as a call key, a seed key, and the call microphone 81 are provided. As the operation keys, for example, a ten key 75 for inputting a telephone number or the like, a cursor movement key 76 for moving the cursor with respect to a menu of various functions, and an outgoing key 77 for initiating a call by pressing down at the time of incoming call , The power key / end key 78 which terminates the call by pressing down during a call, the center key 79 arranged at the center of the multi-directional key 76, the function key 80L arranged at the left and right of the center key 79, 80R).

Ten key 75, cursor movement key 76, origination key 77, power / exit key 78, center key described above in view of the many consumers can enjoy luxury, aesthetic satisfaction and mental comfort. It is preferable to form at least any one of operation keys such as the 79 and the function key 80 with the ceramic for a decorative component of the present embodiment.

The ceramic for decorative parts of the present embodiment obtained as described above has a sense of quality and aesthetic satisfaction, and as a result, the consumer can obtain mental comfort through vision. Watch accessories such as watch cases, watch band nodes, as well as decorative parts for jewelry such as brooches, necklaces, earrings, rings, tie pins, tie tags, medals, buttons, or tiles for decorating floors, walls, ceilings, or It can be used suitably as decorative parts for building materials, such as a door handle, and decorative parts for kitchen parts, such as a spoon and a fork.

EXAMPLE

Hereinafter, embodiments of the present invention will be described in detail. The invention is not limited to these examples.

<Example 1>

First, titanium nitride powder (purity 99 mass% or more, average particle diameter 22.3 micrometers), nickel powder (purity 99.5 mass% or more, average particle diameter 12.8 micrometer) whose composition formula is TiN _x (0.7 <= _x <0.9), niobium carbide powder (purity) The ratio of 99.5 mass% or more, average particle diameter of 7 micrometers, chromium powder (purity of 99 mass% or more, average particle diameter of 40 micrometers), and titanium oxide (purity of 99 mass% or more, average particle diameter of 0.6 micrometers) in the sintered compact is shown in the samples in Table 1. No. 2, 3, and 4 were weighed so as to be a ratio, and pulverized and mixed to obtain a combination raw material.

In Comparative Example a TiN or TiN _{0 .52 0 .95} of the titanium nitride powder (average purity of 99 mass% or more and a particle diameter 22.3㎛), nickel powder (purity: 99.5 mass% or more, average particle diameter 12.8㎛) the composition formula as a carbide, niobium The ratio of the powder (purity 99.5 mass% or more, average particle diameter 7 micrometers), chromium powder (purity 99 mass% or more, average particle diameter 40 micrometers), and titanium oxide (purity 99 mass% or more, average particle diameter 0.6 micrometers) in a sintered compact It weighed so that it might become the ratio in sample No. 1 and 5 of 1, and it grind | pulverized and mixed it as a raw material of a combination.

Subsequently, 2-propanol solution was added to each of the obtained raw materials, which was ground and mixed for 72 hours using a vibration mill. Then, 3 mass% of paraffin wax was added to the raw materials of the combination as a binder, and dried by spray drying. did. Each of the powders thus obtained was press-molded at a molding pressure of 98 MPa to produce a molded product, degreased at 600 ° C. in a nitrogen atmosphere, and then maintained at a temperature of 1530 ° C. for 2 hours in a vacuum atmosphere, followed by sintering to form a disk-shaped sintered body of 16 mm in diameter. Got.

The surface of the sintered compact shown in Sample No. 1-5 of Table 1 was lapping-processed for 1 hour using the diamond grindstone particle | grains of 1 micrometer in particle size using the lapping machine made from tin. Then, this sintered compact, water, and green carborundum (GC) were put into the rotating barrel grinder, and barrel polishing was performed for 24 hours, and the decorative surface was formed. Subsequently, the light source was set to CIE standard light source D65, the viewing angle was set to 10 °, and the measurement range was set to 3 × 5 mm using a spectrophotometer (Konica Minolta Holdings Co., Ltd. CM-3700d), JIS Z 8722- Based on 2000, the color tone of the decorative surface was measured.

About the value of atomic number x of composition formula TiN _x , the ratio of oxygen, nitrogen, and carbon with respect to 100 mass% of titanium nitride was measured using the oxygen and nitrogen analyzer and the carbon analyzer. Then, the number of moles of titanium in the composition formula TiN _x was obtained by dividing the value obtained by subtracting the sum of the respective element ratios from 100 mass% of titanium nitride by the atomic weight of titanium of 47.9. In addition, the number-of-moles of nitrogen in composition formula TiN _x were calculated | required by dividing the ratio of nitrogen by the atomic weight 14 of nitrogen. The value of the nitrogen ratio when the number-of-moles of titanium calculated | required was converted into 1 was made into the value of atomic number x.

In addition, the arithmetic mean height Ra of the decorative surface is 5 mm, 0.8 mm, 2 for the measurement length, the cutoff value, the stylus tip radius, and the stylus scanning speed, respectively, using a stylus type surface roughness meter in accordance with JIS B 0601-2001. Five places were measured as micrometer and 0.5 mm / second, and it was set as the average value.

In addition, since each ratio of the main component, the subcomponent, the first additive component, and the third additive component constituting each sample is a small amount of the second additive component by fluorescence X-ray analysis (XRF), the transmission electron microscope (TEM) ) Using

These measurement results and analysis results are shown in Table 1.

In addition, about the color tone, a questionnaire survey was carried out to three monitors of five men and women in each age group in their 20s and 50s with high quality, aesthetic satisfaction and mental comfort. Among the percentages of the monitors that answered “obtained” to these items, high quality, aesthetic satisfaction, and mental comfort are all 90% or higher, and one of the three items is 'good' or 1 item. Even 70% or less were evaluated as "bad". Table 1 shows the ratio of monitors returned.

As can be seen from the results shown in Table 1, the samples No. 2 to 4 of the present invention having an atomic number x of 0.8 or more and 0.96 or less are all evaluated as "excellent", and from samples No. 1 and 5 outside this range. The monitor was highly appreciated for its high quality, aesthetic satisfaction and mental comfort.

<Example 2>

First, titanium nitride powder (purity 99 mass% or more, average particle diameter 22.3 micrometers), nickel powder (purity 99.5 mass% or more, average particle diameter 12.8 micrometers) whose composition formula is TiN _x (0.7 <= _x <0.9), vanadium nitride, and niobium nitride , At least one of tantalum nitride, molybdenum, niobium, tungsten and tantalum powder (purity of 99.5% by mass, average particle size of 7 µm) and titanium oxide (purity of 99% by mass, average particle diameter of 0.6 µm) in the sintered body It weighed so that it might become the ratio shown to Tables 2-4, it grind | pulverized and mixed, and set it as the combination raw material.

Subsequently, 2-propanol solution was added to each of the obtained raw materials, which was ground and mixed for 72 hours using a vibration mill. Then, 3 mass% of paraffin wax was added to the raw materials of the combination as a binder, and dried by spray drying. did. Then, the obtained powder was press-molded at a molding pressure of 98 MPa to produce a molded product, and after degreasing at 600 ° C. in a nitrogen atmosphere, the mixture was kept at a temperature of 1530 ° C. for 2 hours and calcined to obtain a disc-shaped sintered body having a diameter of 16 mm.

It is shown in Sample No. 6-104 of Tables 2-4 (sample No. 16, 17, 28, 29, 40, 41, 54, 55, 68, 69, 82, 83, 96, 97 is excluded). The surface of the paper was sintered for 1 hour using a diamond lapping machine having a particle size of 1 µm using a tin lapping machine. Then, this sintered compact, water, and green carborundum (GC) were put into the rotating barrel grinder, and barrel polishing was performed for 24 hours, and the decorative surface was formed. Subsequently, the light source was set to CIE standard light source D65, the viewing angle was set to 10 °, and the measurement range was set to 3 x 5 mm using a spectrophotometer (Monica Minolta Holdings Co., Ltd. CM-3700d), JIS Z 8722- Based on 2000, the color tone of the decorative surface was measured.

In addition, the arithmetic mean height Ra of the decorative surface is 5 mm, 0.8 mm, and the measured length, cutoff value, stylus tip radius, and stylus scanning speed, respectively, using a stylus type surface roughness meter in accordance with JIS B 0601-2001. 5 places were measured as 2 micrometers and 0.5 mm / second, and it was set as the average value.

Moreover, lapping process is carried out using the lapping machine which consists of tin on the surface of the sintered compact shown by sample No. 16, 17, 28, 29, 40, 41, 54, 55, 68, 69, 82, 83, 96, 97, After the decorative surface was formed, the color tone and the arithmetic mean height Ra were measured by the same measurement method as described above without performing barrel polishing.

In addition, since the ratios of the main component, the subcomponent, and the first additive component constituting each sample separately are small by the fluorescence X-ray analysis (XRF) method, the ratio of the second additive component is very small, using a transmission electron microscope (TEM). Interpreted.

These measurement results and analysis results are shown to Tables 2-4.

In addition, about the color tone, a questionnaire survey was carried out to three monitors of five men and women in each age group in their 20s and 50s with high quality, aesthetic satisfaction and mental comfort. Among the percentages of monitors that answered “obtained” about these items, high quality, aesthetic satisfaction, and mental comfort are all 90% or higher, and even if one of the above items has 75%, it is 'good' and 1 item Even 70% or less were evaluated as "bad". The ratio of the monitor returned is shown in Tables 2-4.

As can be seen from the results shown in Tables 2 to 4, the average value of the arithmetic mean height Ra of the decorative surface is 0.03 µm or less, the value of the brightness index L * is 72 or more and 84 or less, and the chromaticity index Sample No. 6-15, 18-27, 30-39, 42-53, 56-67, 70-81, of the value of (a *, b *) of this invention which are 3 or more and 9 or less and 27 or more and 36 or less, respectively. 84 ~ 95 and 103 were evaluated as 'excellent' or 'good' and were good results to give the monitor a sense of quality, aesthetic satisfaction and mental comfort. Moreover, when comparing sample No. 10 and sample No. 16, or sample No. 11, and sample No. 17 having the same composition and ratio, the sample No. 10 and the sample No. whose average value of the arithmetic mean height Ra was 0.03 µm or less. As for all .11, the chromaticness index (b *) was higher than the sample No. 16 and the sample No. 17, and it was a favorable result.

In particular, Sample No. 9 containing at least one of 7 to 14.5 mass% nickel, vanadium nitride, niobium nitride, tantalum nitride, molybdenum carbide, niobium carbide, tungsten carbide, and tantalum carbide at a ratio of 2.5 to 10 mass%. ~ 12, 21 ~ 24, 33 ~ 36, 43 ~ 46, 48 ~ 51, 57 ~ 60, 62 ~ 65, 71 ~ 74, 76 ~ 79, 85 ~ 88, 90 ~ 93, 98 And more favorable results.

In addition, sample No. 58-60, 72-74, 86-88, and 98 whose addition component is at least 1 sort (s) of niobium carbide, molybdenum carbide, tantalum carbide, and tungsten carbide, and whose content is 3-8 mass% are mentioned above. The percentage of monitors that answered "obtained" about each item was 100%.

In contrast, Sample No. 103 containing aluminum nitride and Sample No. 104 containing silicon as additive components had a value of brightness index (L *) of less than 72 and a value of Chromaticness index (b *) of 28. Since it was less than, evaluation became "bad" and it was not able to fully satisfy a monitor.

In sample No. 99 containing zirconium oxide as a main component, since the value of the chromaticity index (b *) exceeded 36, the evaluation was 'poor', and the monitor could not be sufficiently satisfied.

In addition, since the value of the brightness index (L *) exceeds 84, the sample No. 102 containing cerium oxide as a main component was evaluated as 'poor', and the monitor could not be sufficiently satisfied.

Sample No. 100 and 101 containing 25.5 to 30 mass% of titanium carbide as an additive component had a value of brightness index (L *) of less than 72 and a value of chromaticness index (b *) of less than 28. It became 'bad' and the monitor could not be satisfied enough.

<Example 3>

First, titanium nitride powder (purity 99 mass% or more, average particle diameter 22.3 micrometers), nickel powder (purity 99.5 mass% or more, average particle diameter 12.8 micrometer) whose composition formula is TiN _x (0.7 <= ≤0.9), molybdenum powder (purity 99.5) The ratio of mass% or more, average particle diameter of 7 micrometers, chromium powder (purity of 99 mass% or more, average particle diameter of 40 micrometers), and titanium oxide (purity of 99 mass% or more, average particle diameter of 0.6 micrometer) in the sintered compact is shown in Table 5. It weighed so that it might be pulverized and mixed and it was set as a combination raw material. The grinding | pulverization and mixing time is as showing in Table 5.

Subsequently, 2-propanol solution was added to each of the obtained raw materials, which was ground and mixed for 72 hours using a vibration mill. Then, 3 mass% of paraffin wax was added to the raw materials of the combination as a binder, and dried by spray drying. did. Then, the obtained powder was press-molded at a molding pressure of 98 MPa to prepare a molded product, and then degreased at 600 ° C. in a nitrogen atmosphere.

The surface of the sintered compact shown to sample No. 105-109 of Table 5 was lapping-processed for 1 hour using the diamond grindstone particle of 1 micrometer in particle size using the lapping machine made from tin. Then, this sintered compact, water, and green carborundum (GC) were put into the rotating barrel grinder, and barrel polishing was performed for 24 hours, and the decorative surface was formed. Subsequently, the light source was set to CIE standard light source D65, the viewing angle was set to 10 °, and the measurement range was set to 3 × 5 mm using a spectrophotometer (Konica Minolta Holdings Co., Ltd. CM-3700d), JIS Z 8722- Based on 2000, the color tone of the decorative surface was measured.

The arithmetic mean height Ra of the decorative surface was measured using a stylus type surface roughness meter in accordance with JIS B 0601-2001 to measure the measurement length, cutoff value, stylus tip radius, and stylus scanning speed, respectively, 5 mm, 0.8 mm, 2 μm, It measured 5 places as 0.5 mm / sec, and computed the average value. After the measurement, the artificial sweat half immersion test (23 ± 2 ° C, left for 24 hours) is applied mutatis mutandis to the samples No. 105 to 109 during the corrosion test prescribed in JIS B 7001-1995, and before and after the test using the measuring method of the color tone described above. The hue of the decorative surface of the was measured.

In addition, each ratio of the main component, subcomponent, 1st additive component, and 3rd additive component which comprises each sample separately is measured by the fluorescence X-ray analysis (XRF) method, and since the ratio of the 2nd additive component is trace amount, it is a transmission electron It analyzed using the microscope (TEM).

These measurement results and analysis results are shown in Tables 5 and 6.

As can be seen from the results shown in Tables 5 and 6, the samples No. 106 to 109 containing chromium have a brightness index (L *) and a chromaticity index as compared to the sample No. 105 containing no chromium. Both a * and b *) show little change before and after the test, and have good corrosion resistance and can maintain high quality, aesthetic satisfaction and mental comfort for a long time.

However, as the number of chromium increases, as can be seen from Sample No. 109, since the chromaticness index (a *, b *) which shows good corrosion resistance but vividly falls, 1.5 mass of chromium should be used to combine corrosion resistance and clarity. Samples No. 106 to 108 contained in a proportion of not less than 6.5% by mass are preferred.

<Example 4>

First, titanium nitride powder (purity 99 mass% or more, average particle diameter 22.3 micrometers), nickel powder (purity 99.5 mass% or more, average particle diameter 12.8 micrometers) whose composition formula is TiN _x (0.7 <= _x <0.9), molybdenum powder, tantalum powder (Purity 99.5 mass% or more, average particle diameter 7 µm) and titanium oxide (purity 99 mass% or more, average particle diameter 0.6 µm) were weighed so that the ratio in the sintered compact becomes the ratio shown in Table 7, and pulverized and mixed to produce a combination raw material. did.

Subsequently, 2-propanol solution was added to each of the obtained raw materials, and the mixture was pulverized and mixed for 72 hours using a vibration mill. Then, paraffin wax was added as a binder so as to be 3% by mass with respect to the raw materials of the combination, followed by mixing. Dried to obtain powder. Then, the obtained powder was press-molded at a molding pressure of 98 MPa to produce a molded product, and then degreased at 600 ° C. in a nitrogen atmosphere, then maintained at 1600 ° C. for 2 hours, and fired to obtain a disc-shaped sintered body having a diameter of 16 mm.

And the surface of this sintered compact was lapping using the tin lapping machine. Then, this sintered compact, water, and green carborundum (GC) were put into a rotating barrel polishing machine, and the opening porosity of the decorative surface was adjusted by barrel polishing by adjusting the time to obtain Sample Nos. 110 to 117 shown in Table 7. . The average value of the color tone and arithmetic mean height Ra of the decorative surface is measured in the same manner as in Example 1, and the open porosity of the decorative surface is 200 times magnification using a metal microscope to introduce the image of the decorative surface into the CCD camera. The measurement area of one field of view in an image is 2.25 × 10 ^-2 mm ² , and the number of field of view is set to 20 by the image analysis device (LUZEX-FS, Inc.), and the measurement total area is 4.5 × 10 ^-1 mm 2. The open porosity in was obtained.

In addition, since each ratio of the main component, the subcomponent, the first additive component, and the third additive component constituting each sample is small by the fluorescence X-ray analysis (XRF) method, the ratio of the second additive component is very small. Using TEM).

These measurement results and analysis results are shown in Table 7.

In addition, about color tone, questionnaire survey was carried out to 40 monitors of five men and women for each age group in their 20s to 50s with three items of high quality, aesthetic satisfaction and mental comfort. Table 7 shows the ratios of the monitors that answered "obtained" to these items.

As can be seen from the results shown in Table 7, the sample Nos. 111 to 113 and 115 to 117 having an open porosity of 3% or less have a lightness index (L *) of 75 to 79 and the lightness indexes of samples No. 110 and 114. Since it is higher than (L *), it turns out that a monitor feels a sense of quality more strongly about sample No. 111-113, 115-117 than sample No. 110, 114.

And it turns out that the chromaticness index b * becomes high with the decrease of the average value of arithmetic mean height Ra. Therefore, when the average value of the arithmetic mean height Ra was 0.03 micrometer or less, it was confirmed that it has favorable golden color.

Claims (10)

The composition formula consists of a main component composed of titanium nitride represented by TiN _x (0.8 ≦ _x ≦ 0.96) and a subcomponent composed of nickel; Also having a decorative surface containing vanadium nitride, niobium nitride, tantalum nitride, molybdenum carbide, niobium carbide, tungsten carbide, and a first additive component consisting of one or more selected from titanium carbide, and a second additive component composed of titanium oxide Ceramic for decorative parts, characterized in that. The arithmetic mean height Ra of the decorative surface is at least 0.03 µm, and the brightness index L * in the CIE1976L * a * b * color space of the decorative surface is 72 or more and 84 or less. And ceramics indexes (a *, b *) are 3 or more and 9 or less and 27 or more and 36 or less, respectively. The ceramic for decorative component according to claim 1 or 2, wherein chromium is contained as the third additive component. The method according to any one of claims 1 to 3, wherein 7 parts by mass to 14.5 parts by mass of nickel as the subcomponent, vanadium nitride, niobium nitride, tantalum denitrification, molybdenum carbide, niobium carbide, A ceramic for decorative part, comprising at least 2.5% by mass and at least 10% by mass of at least one selected from tungsten carbide and tantalum carbide. 5. The ceramic for decorative component according to claim 3 or 4, wherein chromium, which is the third additive component, is contained in a proportion of 1.5% by mass or more and 6.5% by mass or less. The said 1st addition component consists of 1 or more types chosen from niobium carbide, molybdenum carbide, tantalum carbide, and tungsten carbide, The content is 3 mass% or more and 8 mass in any one of Claims 1-5. Ceramic for decorative parts, characterized by less than%. The ceramic for decorative parts according to any one of claims 1 to 6, wherein the open porosity of the decorative surface is 3% or less. A decorative component for watches, comprising the ceramic for decorative components according to any one of claims 1 to 7. The decorative component for portable devices which consists of the ceramic for decorative components of any one of Claims 1-7. A mobile device comprising the decorative component for mobile device according to claim 9.

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