JP2018033569A - Decorative part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decorative part that has a surface being hard to be damaged, and has an appearance being not present before.SOLUTION: A decorative part of the present disclosure contains zirconia as a principal component, and a ratio of the cubic crystal of the zirconia in a first portion of a surface is larger than the ratio of the cubic crystal of the zirconia in a second portion unlike the first portion. Also, the zirconia is contained as the principal component, and the ratio of the cubic crystal of the zirconia in the first portion of the surface is larger than the ratio of the cubic crystal of the zirconia in the second portion unlike the first portion.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to decorative parts.

  Conventionally, decorative parts made of ceramics containing zirconia as a main component (hereinafter also simply referred to as zirconia) have been used in parts that require aesthetics and scratch resistance.

  Mirrored zirconia is often used for decorative parts. For example, zirconia having a matte appearance with fine irregularities is also used, such as the decorative part described in Patent Document 1. .

Japanese Patent Laid-Open No. 08-141918

  In recent years, there has been a demand for decorative parts and the like that are hard to be scratched on the surface and have a (new) appearance different from the conventional ones.

  The present disclosure provides a decorative part that contains zirconia as a main component, and in which the proportion of cubic zirconia in at least a portion of the surface is larger than the proportion of cubic zirconia in the interior.

  Further, the present invention also provides a decorative part that contains zirconia as a main component and has a zirconia cubic crystal ratio in the first part of the surface larger than a zirconia cubic crystal ratio in the second part different from the first part.

  The decorative component of the present disclosure is hard to be scratched on the surface and has an unprecedented appearance.

It is a XRD pattern of the result of having measured the crystal structure about embodiment of a decorative component, (a) has shown the measurement result of the 1st part, (b) has shown the measurement result of the 2nd part. (A) is an electron micrograph image of the 1st part of the surface of the decorative component of this embodiment, (b) is an electron micrograph image of the cross section of the area | region containing a 1st part.

  Hereinafter, embodiments of the decorative component of the present disclosure will be described in detail.

The decorative part of the present disclosure contains zirconia as a main component. The decorative part mainly composed of zirconia is hardly damaged even when used for a long period of time, and the aesthetic appearance is hardly impaired. Zirconia may contain a pigment component for coloring. The material of the decorative part is measured using an X-ray diffractometer (XRD: for example, D8 ADVANCE manufactured by Bruker AX), and is identified using a JCPDS card from the value of 2θ (2θ is a diffraction angle) obtained. That's fine. Note that the decorative surface can be observed with a scanning electron microscope (SEM), and the material constituting the decorative surface can be estimated using an energy dispersive X-ray spectrometer (EDS) attached to the SEM. For example, if zirconium (Zr) and oxygen (O) are detected in the EDS measurement of a plurality of particles observed with an SEM, it can be estimated that the particles are zirconia.

  The decorative parts of the present disclosure include not only accessories and furnishings but also articles such as watches, mobile terminals, door knobs, etc. that are often touched by human hands, fingerprint sensors-unlocking devices, mobile vehicles such as automobiles, etc. It can be used as an article such as a door release button having a high fingerprint chance, or a part requiring a decorative value.

  Hereinafter, embodiments will be described. The decorative part of this embodiment is a decorative part containing zirconia as a main component, and the proportion of cubic crystals of zirconia in at least a part of the surface (hereinafter also referred to as a first part) is the cubic of zirconia in the interior. Greater than percentage.

  The crystal structure of zirconia has a larger volume per unit mass in cubic than in tetragonal. In this first portion, where the proportion of cubic crystals is larger than that of tetragonal crystals, the compressive stress is larger than that of the inside, and the hardness is relatively high.

  The decorative part of the present embodiment has a relatively high hardness in the first part, and the surface is not easily scratched, and since the inside is protected by the first part, a large defect or the like that reaches the inside is difficult to occur. .

  The decorative part of the present embodiment has a second portion different from the first portion on the surface, and the proportion of cubic zirconia in the first portion is larger than the proportion of cubic zirconia in the second portion. . The first portion having a relatively large proportion of cubic crystals has a higher hardness than the second portion. The second part has the same appearance characteristics as a conventional decorative part made of zirconia.

  In the decorative part of the present embodiment, the area ratio of the first part may be larger than that of the second part. In such a case, since the first portion has high hardness and is difficult to be scratched, it is preferable to arrange the first portion in a portion that easily comes into contact with the surface of another member, such as a wristwatch band or a bezel surface.

  In the decorative part of the present disclosure, the arithmetic average roughness (Ra) in the first portion may be larger than the arithmetic average roughness (Ra) in the second portion. In such a case, the first portion having a large arithmetic average roughness (Ra) has a so-called matte appearance with a calm texture. In addition, the second portion having a lower arithmetic average roughness (Ra) than the first portion has a so-called mirror-like appearance with relatively large gloss and glare. The decorative part of the present embodiment has a different appearance from a conventional decorative part by having both a mirror-like appearance and a matte appearance.

  In addition, since the decorative part of this embodiment has a relatively large arithmetic average roughness (Ra) of the first part, when a person touches the decorative surface, sebum adheres to the bottom of the part that becomes the valley of the decorative surface. It is hard to do. For this reason, sebum hardly remains as a continuous linear stain. Furthermore, even if sebum remains at the bottom of the valley portion, the surface properties are such that sebum is difficult to see. Therefore, the first portion of the decorative component of the present embodiment has a decorative surface that not only makes fingerprints difficult to attach, but also makes fingerprints less noticeable. In the decorative part of this embodiment, it is preferable to arrange the first part in a place where a human finger or the like can easily touch.

  In the decorative part of the present embodiment, for example, the arithmetic average roughness (Ra) in the first portion is 0.15 μm or more. When satisfying such a configuration, it is easily visible in a so-called mat shape and has a calm appearance.

  In the decorative part of the present embodiment, the arithmetic average height (Rz) in the first part may be larger than that in the second part. Even in such a case, the first portion has a so-called matte appearance with a calm texture rather than a mirror-like gloss or glare appearance. In addition, the decorative component of the present embodiment is less likely to have fingerprint stains when a person touches the decorative surface even when the arithmetic average height (Rz) is relatively large. In the decorative part of the present embodiment, for example, the arithmetic average height (Rz) in the first portion is 0.7 (μm) or more.

  An embodiment of the tint in the decorative part of the present embodiment will be described. In the first embodiment, the first part and the second part each have a lightness index L * of 10 or less in the CIE 1976 L * a * b * color space, and the first part has a lightness index L * that is less than the L * of the second part. L * is larger. Both the first part and the second part have a small L *, and both have a color generally recognized as black.

  In the first embodiment, the lightness index L * in the CIE 1976 L * a * b * color space is larger in the first part than in the second part. The first portion has a matte tone, but is not simply a matte tone, and has a slightly lighter color than the second portion. In the first embodiment, the chromaticness index b * in the CIE 1976 L * a * b * color space is smaller in the first part than in the second part. The first part has a slightly bluish color than the second part. The first portion is not only less glossy than the second portion, but the color impression also exhibits contrast with the second portion. The decorative component according to the first embodiment can express various designs by such color contrast and has a high degree of freedom in design design.

  Further, in the first embodiment, although it has a black color as a whole, it has a so-called mat-like first portion and a mirror-like second portion on the surface. In the first embodiment, various designs can be expressed by the contrast between the mirror surface portion (second portion) and the matte portion (first portion), and the degree of freedom in design is high. In the first embodiment, since the first part and the second part are both black, the impression when the viewer visually recognizes at a glance is entirely black, but if the predetermined part is observed carefully, characters can be read. It can be set as such a structure.

  In the second embodiment of color, the lightness index L * in the CIE 1976 L * a * b * color space of the first part is 10 or less, and the lightness index L * of the second part is 80 or more. In the second embodiment, the first portion has a color generally recognized as black, and the second portion has a color generally recognized as white. In the second embodiment, which is a combination of a black first portion and a white second portion, the surface has a matte black first portion and a mirror-like white second portion. . In the first embodiment, various designs can be expressed by the extreme contrast between the white portion (second portion) and the black portion (first portion), and the degree of freedom in design design is high. In the second embodiment, the first portion and the second portion having colors that are extremely different visually are provided, and the contrast between the first portion and the second portion can be obtained only by an observer. The design of the formed character etc. can be recognized clearly.

  In either the first embodiment or the second embodiment, for example, the first part or the second part is arranged in a shape corresponding to a character or a symbol, and the other surface part (the first part or the second part) is arranged around the periphery. ), The shape of characters, symbols, etc. can be read by the observer. In addition, the first part and the second part are each formed into a shape pattern having a relatively large area, and the first part and the second part are arranged, for example, next to each other or alternately in a lattice pattern, thereby clearly It is also possible to configure an appearance with high design, in which two different colors are arranged.

  Hereinafter, a method for manufacturing a decorative part according to the present disclosure will be described.

  First, a sintered body made of zirconia is prepared. Next, the surface of the sintered body is ground using a surface grinder. Next, barrel polishing is performed on the ground surface in a processing time of 10 hours to 60 hours. At this time, grinding is performed using a grinding wheel having a count of # 170 to # 400, and then barrel polishing is performed using abrasive grains having a count of # 150 or less as a compound. The barrel-polished surface is mirror-like and is a surface corresponding to the second portion.

  Then, an electron beam is irradiated to the predetermined site | part of the surface of the polished target member. The decorative part of the present disclosure can be obtained by altering the zirconia at a predetermined site by irradiation with the electron beam.

  The surface portion irradiated with the electron beam is a surface corresponding to the first portion. A decorative part in which a first part obtained by electron beam irradiation and a second part made mirror-finished by barrel polishing are arranged on the surface by performing electron beam irradiation partially. Can be obtained. The portion irradiated with the electron beam is a first portion in which the ratio of cubic zirconia to tetragonal zirconia is higher than the ratio of cubic zirconia to tetragonal zirconia inside. This is presumed to be a result of the crystallization being promoted by the increase in temperature of the portion irradiated with the electron beam.

  In the present embodiment, the first portion irradiated with the electron beam has a larger surface roughness (Ra) and surface height (Rz) and higher hardness than the second portion not irradiated with the electron beam.

  And about a 1st embodiment, first, the black zirconia sintered compact containing a pigment is prepared, The electron beam irradiation is partially performed with respect to this black zirconia, and the color of the 1st embodiment is given. A decorative part having the same can be formed.

  For the second embodiment, a white zirconia sintered body that does not contain a pigment is first prepared, and the white zirconia is partially irradiated with an electron beam, so that the color of the second embodiment is obtained. A decorative part having a taste can be formed. That is, the first portion irradiated with the electron beam changes color from white to black by the electron beam irradiation, and the second portion not irradiated with the electron beam remains white.

  Properties such as surface roughness (Ra), surface height (Rz) and color of the first part obtained by electron beam irradiation depend on irradiation energy, irradiation angle / distance, irradiation time, etc. at the time of electron beam irradiation. Change. By adjusting these conditions, for example, the surface roughness (Ra) and the surface height (Rz) of the second part not irradiated with the electron beam are larger than those of the first part irradiated with the electron beam, Hardness can also be increased. The decorative component of the present disclosure can be manufactured in various embodiments by adjusting the conditions of electron beam irradiation, and is not limited to the above embodiment.

[Crystal structure]
FIG. 1 is an XRD pattern as a result of measuring the crystal structure of the manufactured decorative part, where (a) shows the measurement result of the first part and (b) shows the measurement result of the second part. The measurement was performed using X'Pert PRO manufactured by PANalytical under the condition of 2θ = 10 ° to 80 ° with CuKα ray. The X-ray diffraction pattern was analyzed using the analysis software attached to this apparatus, and the crystal structure contained in each part was derived. Although the cubic peak did not appear in FIG. 1B showing the second portion, it was confirmed that the cubic peak appeared in FIG. 1A shown for the first portion. In the first part, cubic crystals are formed by electron beam irradiation, and it can be seen that the first part contains more cubic crystals than the inside and the second part.

[Surface condition, roughness, etc.]
FIG. 2A is an electron micrograph image of the first portion of the surface of the decorative part of the present embodiment, and FIG. 2B is an electron micrograph image of a cross section of the region including the first portion. As shown in (b), the surface layer in a state different from the inside where the crystal grains are aggregated is formed in the portion irradiated with the electron beam. And as shown to (a), the surface covered with this surface layer has unevenness partially. This unevenness is presumed to have occurred in the portion irradiated with the electron beam because the volume of the crystal layer increased with the alteration of the crystal layer.

As a result of measuring arithmetic mean roughness (Ra) and arithmetic mean height (Rz) for each of the first part and the second part, the arithmetic mean roughness (Ra) is 0.019 (μm) in the second part. On the other hand, the first portion was as large as 0.192 (μm). Also, the arithmetic average height (Rz) of the second portion was 0.0066 (μm), whereas the first portion was as large as 0.990 (μm). In addition, these Ra and Rz were measured by a method based on JIS standard JIS B 0601: 1982 using SE-30H manufactured by Kosaka Laboratory. It can be seen that the surface roughness (Ra) and the surface height (Rz) are increased by the electron beam irradiation.

[appearance]
A sample obtained by partially irradiating black zirconia with an electron beam and a sample obtained by partially irradiating white zirconia with an electron beam were prepared, and an electron beam irradiated portion (first portion) and an electron beam of each sample were irradiated. The value of the L * a * b * color space was measured for the part that was not (second part). The results are shown in Table 1 below. The measurement was performed using Nippon Denshoku Industries Co., Ltd. spectral color difference meter NF777.

  The black zirconia irradiated with the electron beam has a slight color difference between the first portion irradiated with the electron beam and the second portion not irradiated with the electron beam, but the color visually recognized remains black. Only the first portion irradiated with the electron beam had a matt tone color selectively.

  Further, in the white zirconia irradiated with the electron beam, only the first portion irradiated with the electron beam has the visible color dramatically changed from white to black, and the first portion is a so-called matte color. It had a taste.

[hardness]
A sample in which white zirconia was partially irradiated with an electron beam was prepared, and the hardness and elastic modulus were measured for an electron beam irradiated portion (first portion) and a portion not irradiated with an electron beam (second portion). The measurement was performed using Nano Indenter XP manufactured by MTS. The results are shown in Table 2 below.

  The electron beam irradiated part (first part) was larger in hardness than the second part. It is presumed that the hardness increased as the crystal volume increased (expanded) due to electron beam irradiation.

Claims (6)

  A decorative part containing zirconia as a main component, wherein the proportion of cubic zirconia in at least a part of the surface is larger than the proportion of cubic zirconia in the interior.   A decorative part comprising zirconia as a main component, wherein the proportion of cubic crystals of zirconia in the first portion of the surface is larger than the proportion of cubic crystals of zirconia in a second portion different from the first portion.   The decorative part according to claim 2, wherein the arithmetic average roughness (Ra) in the first portion is larger than the arithmetic average roughness (Ra) in the second portion.   The decorative part according to claim 2 or 3, wherein an arithmetic average height (Rz) in the first portion is larger than an arithmetic average height (Rz) in the second portion.   The first part and the second part both have a lightness index L * in the CIE 1976 L * a * b * color space of 10 or less, and the L * of the first part is less than the L * of the second part. The decorative part according to any one of claims 2 to 4, wherein the decorative part is larger.   5. The lightness index L * in the CIE 1976 L * a * b * color space of the first part is 10 or less, and the lightness index L * of the second part is 80 or more. Decorative parts.