WO2008044333A1

WO2008044333A1 - Production method of diamond particles having colored cut faces, and production method of diamond particles having pattern-drawn cut faces

Info

Publication number: WO2008044333A1
Application number: PCT/JP2007/001085
Authority: WO
Inventors: Shohei Taniguchi; Yukinori Saito
Original assignee: Tokyo Metropolitan Industrial Technology Research Institute; University Of Yamanashi
Priority date: 2006-10-05
Filing date: 2007-10-04
Publication date: 2008-04-17
Also published as: JP2008094634A; JP5177472B2

Abstract

A production method of diamond particles having colored cut faces, and a production method of diamond particles having pattern-drawn cut faces. The first invention is characterized by irradiating the cut face to be colored of a diamond particle with high energy ions by an ion accelerator within a temperature range of room temperature to 200°C, under a vacuum atmosphere of 10-3 to 10-4 Pa, at an acceleration energy of 1 to 5 MeV, and with an ion irradiation amount of 1x1012 to 1x1015 ions/cm2. The second invention is characterized by covering a cut face with a mask drilled with a hole worked into a character or mark shape or a mask by photoresist, and then irradiating with high energy ions similarly in the first invention.

Description

Specification

Method for producing diamond particles colored on the cut surface, and method for producing diamond particles having a pattern drawn on the cut surface

Technical field

TECHNICAL FIELD [0001] The present invention relates to a method for producing diamond particles having a cut surface and a method for producing diamond particles having a pattern drawn on a cut surface. More specifically, high-energy ions are implanted into the cut surface of the diamond particles to produce diamond particles with colored cut surfaces, and patterns such as letters or marks are drawn on the diamond particle cut surface. The present invention relates to a method for producing diamond particles.

Background art

[0002] Diamond particles are transparent, colorless, and large in value. However, most diamond particles have low transparency, and small ones are selected for industrial use. Therefore, a method of coloring diamond particles with low transparency and low commercial value for jewelry has been proposed and put into practical use. Conventionally, diamond particles can be colored by (1) high-pressure and high-temperature treatment (HPHT) method, (2) electron beam irradiation method, (3) neutron irradiation method,

(4) Radium treatment method, (5) Low energy ion implantation method, etc. are known. The above (1) HPHT method is a method that requires high-temperature heating to several thousand degrees and pressure of several hundred kilobars, and further requires a long time of several tens of hours (Patent Document 1 to Patent Document) 2) In these proposed methods, the entire diamond particle surface is colored, so it is not possible to color-color on only some of the cut surfaces or draw patterns on only some of the cut surfaces.

[0003] In the electron beam irradiation method (2) above, an electron beam of several MeV is irradiated on the cut surface of the diamond particle, and then annealed at a temperature of about 100 ° C for several hours to several tens of hours. This is a ringing method (see Patent Documents 3 to 7). According to these proposed methods, the secondary X generated when the diamond particle cut surface is irradiated with an electron beam. It is necessary to shield the line, and the facility becomes large. Also, the electron beam of several MeV has high penetrating power and easily generates scattered radiation. Therefore, it is difficult to shield the scattered radiation even if a mask is applied to the child cut surface of the diamond grain. It is difficult to draw patterns such as letters or marks.

[0004] The neutron irradiation method of (3) above includes a method of irradiating a child cut surface of a diamond grain with a nuclear reactor or the like (see Patent Document 8), and then several hundreds. A method of heat treatment with C (see Patent Document 9 and Patent Document 10) has been proposed. These proposed methods require a large-scale facility such as a nuclear reactor and may activate impurities in the diamond particles, resulting in a risk of residual radioactivity when using jewelry. Since neutrons with high energy have high penetrating power, even if a mask is applied to the cut surface of diamond particles, the mask cannot prevent neutron transmission. It is impossible to draw characters or marks on the surface.

[0005] The radium treatment method of (4) above is a method of irradiating the diamond particle cut surface with a strand emitted from radium. The treatment proposed by Wi II iam Crooks in 1904 Is the law. In this method, in order to put the diamond particles in the radium salt, radioactive material that is the daughter nuclide of the radium adheres to the cut surface of the diamond particles. In addition, since it is not a beam-like string irradiation, it is difficult to draw a pattern such as a letter or mark on only a part of the diamond particle cut surface.

[0006] As a low energy ion implantation method of the above (5), the method described in Patent Document 11 has been proposed. However, there is a step of performing a heat treatment at 500 ° C or higher after low energy ion implantation. Necessary (see Patent Document 1 2). In this method, since the ion energy is as low as 50 to 1 OO keV, the surface modification is only in a shallow region from the cut surface to the order of several tens of nanometers. Ions are diffusing. Also, the ion implantation amount requires 5 X 10 ^{15 to} 5 X 10 ' ⁸ ion cm ² and a large amount of implantation. In addition, as described in the examples The coloring method describes only one black color, and does not describe coloring with other colors. Furthermore, characters such as letters and marks drawn by heat treatment may diffuse and become blurred.

[0007] As a method of drawing a pattern such as a print or a mark on the cut surface of diamond particles, there is a method of finely processing the diamond surface. For example, the method described in Patent Document 13 is a method of etching with a focused ion beam. Further, the method described in Patent Document 14 is a method of performing plasma etching after masking. In addition, laser processing methods are known, and diamond particle identification, identification, warranty, etc. numbers and symbols are engraved, and each certificate is engraved with the diamond particles. Are used to prove that they are the same, and to prove that they are artificial diamonds. However, these techniques are processing by cutting the diamond surface, so color drawing is impossible.

[0008] Patent Document 1: Japanese Translation of Special Publication 2004-505765

Patent Document 2: Japanese Translation of Special Publication 2003-528023

Patent Document 3: Japanese Patent Application Laid-Open No. 1-131014

Patent Document 4: Japanese Patent Laid-Open No. 1-1381 1 2

Patent Document 5: Japanese Unexamined Patent Publication No. 1-183409

Patent Document 6: JP-A-6-26341-8

Patent Document 7: Japanese Patent Publication No. 5_36399

Patent Document 8: Japanese Patent Publication No.57-401-20

Patent Document 9: Japanese Patent Laid-Open No. 63-1 62600

Patent Document 10: JP-A-6_21 9895

Patent Document 11: JP-A-2005-247686

Patent Document 12: JP-A-2005-247686

Patent Document 13: Japanese Patent Laid-Open No. 6_36594

Patent Document 14: Japanese Patent Application Laid-Open No. 2002_226290

Disclosure of the invention Problems to be solved by the invention

[0009] The object of the present invention is as follows.

1. To provide a method for producing colored diamond particles having high value as jewelry by coloring the cut surface of diamond particles having low commercial value.

2. To provide a method for producing colored diamond particles that can be processed in a short time and does not require heat treatment after irradiation.

3. To provide a method for producing diamond particles, in which patterns such as letters or marks are drawn only on the cut surface of the — part.

Means for solving the problem

[0010] In order to solve the above-mentioned problems, according to the first invention, in the method for producing diamond particles colored on the cut surface, the cut surface of the diamond particles to be colored has a temperature range from room temperature to about 200 ° C. , 1 0 ³ to 1 0- ⁴ vacuum atmosphere of P a, the ion accelerator, range acceleration energy of 1 to 5 m e V, irradiation injection amount of ^{1 X 1 0 12 ~ 1 X} 1 0 15 ions of an ion Provided is a method for producing diamond particles colored on the cut surface, characterized by irradiating high-energy energy ions in the range of / cm ² .

[0011] Further, in the second invention, in the method of manufacturing diamond particles having a pattern drawn on the cut surface, the diamond particle cut surface is processed into a shape such as a character or a mark and a hole or a mask is perforated. after coating Te cowpea a mask, a temperature range of room temperature to about ^{200 ° C, 1 0- 3 ~1} 0 - 4 P vacuum atmosphere under a, from drilling holes, 1 to 5 m e acceleration energy by an ion accelerator A diamond with a pattern drawn on the cut surface, which is characterized by irradiating high-energy ions in the range of V and ion irradiation in the range of 1 X 10 ¹² to 1 X 10 ¹⁵ ions / cm ² A method for producing particles is provided.

The invention's effect

[0012] The present invention is described in detail below, and has the following particularly advantageous effects, and its industrial utility value is extremely large.

1. The manufacturing method according to the present invention is performed at a high temperature of several thousand degrees like the conventional HPHT method. Since it can be carried out in the temperature range from room temperature to about 200 ° C without requiring heat or high pressure, it can be applied even after setting diamond particles on a noble metal ring.

2. The conventional electron beam irradiation method needs to shield secondary X-rays generated during electron beam irradiation, which requires a large facility, but according to the manufacturing method according to the present invention, the ion accelerator to be used is Since secondary X-rays are rarely generated, no shielding facilities are required, so the facility does not become large.

3. The conventional electron beam irradiation method requires a heat treatment step for several hours at a temperature of about 100 ° C. after irradiation, but according to the manufacturing method according to the present invention, after ion irradiation to diamond particles, No heat treatment or annealing is required, and colored diamond particles can be produced in a few minutes to an hour, greatly improving productivity.

4. The conventional neutron irradiation treatment method requires a large-scale facility such as a nuclear reactor and a large accelerator, and impurities in the diamond may be activated after irradiation. For example, the amount of ion energy to irradiate is not enough to activate impurities, so there is no risk of diamond particles being activated.

5. The conventional low energy ion implantation method requires a large amount of ion implantation, but according to the manufacturing method of the present invention, the amount of ion irradiation (implantation) can be achieved by the conventional low energy ion implantation method. The amount can be reduced to less than 1 / 100th of the amount.

6. According to the production method of the present invention, it is possible to produce a variety of colored products because the color type and color density can be adjusted by adjusting the type and irradiation time of the ion source.

7. According to the manufacturing method of the present invention, it is possible to draw an arbitrary pattern on the cut surface of diamond particles, and it is possible to manufacture a high-value-added jewelry with an original design that is not present.

8. According to the manufacturing method of the present invention, patterns such as numbers and letters can be easily drawn on the cut surface of diamond particles, so that it is possible to draw an identification number, manufacturer logo, and manufacturer mark on diamond particles. And by these drawing Because it can be easily distinguished from fake brands, customer confidence in diamond particles can be increased.

Brief Description of Drawings

FIG. 1 is a schematic diagram of an ion accelerator.

FIG. 2 is a schematic side view showing an example in which diamond particles are fixed to a fixture and irradiated with ions.

FIG. 3 is a schematic side view showing an example of producing diamond particles having a pattern colored on the cut surface.

FIG. 4 is a schematic side view showing another example when producing diamond particles having a pattern colored on the cut surface.

FIG. 5 is a plan view of an example of diamond particles with a picture drawn on the cut surface.

FIG. 6 is a schematic side view of an example of diamond particles with characters drawn on the cut surface.

FIG. 7 is an enlarged view of characters formed on the girdle part.

Explanation of symbols

1 Ion accelerator

2 Cesium sputter ion source

3 Lead electrode

4 Electromagnet for mass separation

5 Tandem accelerator

6 Electromagnet for energy separation

7 Scan electrode

8 Neutral ■ Ion separation electrode

9 Irradiation room

1 0, 1 1 Diamond particle fixture

1 2, 1 4, 1 7 Diamond particles

1 3, 1 6, 1 9

1 5 Mask 1 8 Photoresist layer

2 0 Heart-shaped pattern

2 1 Number pattern

BEST MODE FOR CARRYING OUT THE INVENTION

[0015] Hereinafter, the present invention will be described in detail.

In the present invention, the diamond particles refer to particles obtained by processing natural diamond ore into particles and cutting out the surfaces of the cut particles. The type of diamond is not particularly limited, and may be any of Ia type, Ib type, IIa type, and IIb type. There are no particular restrictions on the shape of the diamond particle cutlet, and conventionally known cutlet shapes such as Muskie's cut, baguette cut, oval cut, French cut, pair sharp cut, briolette cut Table cut, rose cut, force position force, step cut, brilliant full cut, eight cut, scissor cut, emerald cut, etc. The size of the diamond particles is not particularly limited as long as it can be fixed to the fixing base when irradiating with ions. If diamond particles are small, the drawing pattern should be reduced accordingly.

[0016] When the production method according to the present invention is used, the cut surfaces of the diamond particles are colored and / or patterns such as letters and marks. In the present invention, coloring means coloring the cut surface of the diamond particles, and in the present invention, the pattern is an identification number, manufacturer mark (symbol), manufacturer logo (continuous characters), and other small letters. Means patterns, symbols, etc. The cut surface to be colored or patterned may be any surface such as a table, star facet, bezel facet, upper girdle facet, lower girdle facet, pavilion facet set, girdle. The force surface on which coloring or a pattern is applied may be one surface or a plurality of surfaces including two or more surfaces.

[001 7] In order to color the cut surface of the diamond particles by the manufacturing method according to the first aspect of the present invention, the diamond particles are held by a holder, and the ion accelerator It is installed at a predetermined position in the ion irradiation chamber, and the cut surface is irradiated with ions accelerated by the ion accelerator. The holder is preferably made of a material that does not deform such as softening, melting, and vaporization under the conditions for irradiating ions to the cut surface of the diamond particles and that has a heat resistance of 200 ° C. or higher. Specific examples include stainless steel, platinum, titanium, titanium alloys, magnesium alloys, aluminum, and aluminum alloys. Alternatively, the diamond particles may be set on a noble metal base such as a ring.

[0018] As the ion accelerator used in the present invention, a commercial ion irradiation (implantation) device can be used. Commercial ion accelerators include a cesium sputter ion source and a cockcroft ■ Walton ion accelerator (see Fig. 1 below) using a tandem accelerator tube. These ion accelerators place a powdery raw material on an ion source to generate target ions. Impurity ions derived from impurities contained in the raw materials are controlled by a mass separation electromagnet. The impurity ions are separated by bending and mass. Select the target ion because the lighter than the target ion bends more than 90 degrees and the heavier ion than the target ion turns less than 90 degrees by the magnetic force set in the mass separation electromagnet. Can be separated.

[001 9] The ion acceleration energy when irradiating ions on the force surface of diamond particles penetrates into the inside of a few micrometers from the surface of the cut surface, and the surface into which this ion penetrates is the type of ion. Colored according to ion irradiation energy, ion dose, etc. The acceleration energy for irradiation should be selected in the range of 1 to 5 MeV. If the ion acceleration energy is less than 1 MeV, the ion penetration (arrival) depth from the cut surface is shallow, and the diamond cut surface is insufficiently colored, and if the ion acceleration energy exceeds 5 MeV, irradiation occurs. Occasionally diamond particles may become hot, both of which are undesirable. For example, when the temperature of diamond particles exceeds 500 ° C., there is a great risk that the diamond particle surface will be oxidized by reacting with a small amount of oxygen remaining in the irradiation chamber. If diamond particles are set on a precious metal pedestal, If the temperature of the diamond particles is close to 1 ooo ° c, it will be close to the melting point of the pedestal metal, and the equipment will become large and expensive, which is not preferable.

[0020] The ion irradiation dose is selected in the range of 1 X 10 ¹² to 1 X 10 ¹⁵ ions / cm ² . If the ion irradiation dose is less than 1 X 10 ¹² ions / cm ² , the ion irradiation dose is insufficient, the diamond particle cut surface is insufficiently colored, and the ion irradiation dose is 1 X 1 0 ¹⁵ Exceeding ioncm ² is not preferable because the ratio of the diamond crystal becoming graphite or amorphous increases and becomes black only, making it difficult to color various colors.

[0021] When morphism irradiation in Katsuhito surface of diamond particles was accelerated ions by ion accelerator, the degree of vacuum 1 0 - shall choose ⁴ in the range of P a - ³ ~ 1 0. The degree of vacuum is 1 0 - is less than ³ P a, the force to fly the ions is weak, not only can not accelerate I O emissions is low vacuum, because there is a risk of discharge because a high voltage is loaded It is. In addition, if there is a large amount of residual gas in the ion irradiation chamber, it will enter the cut surface of the diamond particles together with the accelerated target ions, so that it will be colored in the color of the residual gas ions other than the target ions. Coloration degree of vacuum 1 0 - exceeds ⁴ P a, etc. is required baking irradiation chamber (operation for increasing the degree of vacuum by heating), it takes time to sample change is undesirable.

[0022] Examples of the types of ions that can be irradiated include ions such as gold (A u), silicon (S i), carbon (C), and boron (B). The concentration of the color imparted to the cut surface of the diamond particles can be easily changed by changing the intensity of the ion acceleration energy, the amount of ion irradiation, and the like. For example, Au ions are light brown to brown to black, Si ions are dark green to light green, C ions are green to light green, and B ions are yellow green to light yellow green (in the examples described later). (See Table 1). According to the manufacturing method of the present invention, only the irradiated cut surface is colored by irradiating the cut surface of the diamond particle with ions, but since the cut diamond particle has a plurality of cut surfaces, it is complicated. Reflected and shining, diamond particles have a commercial value as jewelry. [0023] According to the second aspect of the present invention, after the cut surface of the diamond particle is coated with a mask or a photoresist in which holes are perforated in a shape such as letters or marks (FIG. 3, FIG. As in the first invention described above, the diamond particles are held by the holder and held in the ion irradiation chamber of the ion accelerator, and the ions accelerated by the ion accelerator are extracted from the drilled holes. Irradiate the cut surface. The cut surface is patterned according to the pattern of the hole drilled in the mask or photoresist (see Fig. 5 and Fig. 6 below).

[0024] The material that can be used as a mask is made of a material that does not deform, such as softening, melting, and vaporization, under the conditions when ions are irradiated onto the diamond particle cut surface, and that has a heat resistance of 200 ° C or higher. Is preferred. Specific examples include aluminum, stainless steel, silicon, magnesium, titanium, and platinum. If the mask is too thin, the ion transmission cannot be blocked. Therefore, the mask should be thick enough to block the ion transmission. Although it depends on the material, a thickness of several tens of micrometers or more is preferable.

[0025] Processed into a shape such as letters or marks on the mask, as a method of drilling holes, laser processing method, ion beam processing method, electron beam processing method, cutting processing method, electrolytic processing method, electric discharge processing method, etching Law. The hole drilling method should be selected according to the mask material and the pattern size to be formed. Any photoresist can be used as long as it can withstand the temperature during ion irradiation and can adhere to the diamond particle surface. Photoresist materials having such properties differ depending on the light source used for exposure of the photoresist. When the exposure light source is ultraviolet, an ultraviolet resist containing cyclized rubber and bisazide, an ultraviolet resist containing a diazoquinone compound, and the like can be mentioned. When the exposure light source is an electron beam, an electron beam resist containing polymethyl methacrylate (PMMA), an electron beam resist containing polyhexafluorobutyl methacrylate (FBM), polyhexafluoropropyl methacrylate (FPM) ) And the like. When the exposure light source is X-ray, X-ray resist containing PMMA, X-ray resist containing FBM, etc. . As a method of punching holes by processing the photoresist 卜 into letters or marks, the resist is coated on the diamond particles, holes are drilled through the exposure and development processes, and ions are formed from these holes. Irradiate (inject) and draw the desired pattern on the diamond particle surface.

[0026] The ion generation source (apparatus) that can be used in carrying out the second invention according to the present invention may be the same type as that used in the first invention, and the type of ion, ion irradiation intensity, and ion irradiation The degree of vacuum and the like may also be the same as described in the first invention. Patterns such as letters or marks colored in a desired color on the cut surface can be drawn on the cut surface by means of ions passing through holes formed in the mask or the photoresist.

Next, an outline of a method for producing colored diamond particles by the method according to the present invention will be described. FIG. 1 is a schematic view of an example of an ion accelerator used in the manufacturing method according to the present invention. The ion accelerator 1 includes a cesium sputter ion source 2, an extraction electrode 3, a mass separation electrode 4, a tandem acceleration tube 5, an energy separation electromagnet 6, a scanning electrode 7, a neutral ion separation electrode 8, an irradiation chamber 9 It is composed of diamond particle fixtures 10.

In FIG. 1, the ions generated from the cesium sputter ion source 2 are negative ions, and the ion source is a powder of the above-exemplified substance having an average particle size of several tens to several hundreds. A micrometer one is used. In Fig. 1, the arrow indicates the direction of ion transport (travel, transport). Negative ions are introduced to the mass separation electrode 4 by the extraction electrode 3 with an acceleration energy of about 20 keV. Impurity ions contained in the introduced negative ions are separated here, and only the target ions are separated and transferred to the tandem accelerator tube 5. The central part of the tandem accelerator tube 5 is a positive electrode, and the negative ion is accelerated to the central part. The voltage that can be applied at the center is in the range of 100 kV to 1.7 MV. The ions converted into positive ions at the center of the tandem accelerator tube 5 are further accelerated and transferred toward the end of the tandem accelerator tube 5. A positive ion may have multiple ions with different valences. Since the acceleration energy is different, it is separated into single acceleration energy by the energy separating electromagnet 6, scanned to form a uniform beam by the scanning electrode 7, and irradiated to the cutting surface of the diamond particles installed in the irradiation chamber 9. Is done.

FIG. 2 is a schematic side view showing an example of a state in which diamond particles are fixed to a fixture and irradiated with ions based on the first invention. In FIG. 2, the brilliant-cut diamond particle 12 is fixed to the opening of the diamond particle fixture 11 with only the table surface exposed to the ion irradiation port. The high-tech energy ions 13 are irradiated to the table surface from the opening of the diamond particle fixture 11 and only the table surface is colored.

FIG. 3 is a schematic side view showing an example of manufacturing diamond particles having a pattern colored on the cut surface based on the second invention, and FIG. 4 is a cut based on the second invention. FIG. 5 is a schematic side view showing another example of producing diamond particles having a colored pattern on the surface, and FIG. 5 is a plan view of an example of diamond particles with a picture drawn on the cut surface. Fig. 5 is a schematic side view of an example of diamond particles in which characters are drawn on a cut surface.

In FIG. 3, 14 is diamond particles, 15 is a mask for shielding high energy ions, and 16 is high-engineered energy ions. In Fig. 4, 17 is diamond particles, 18 is a photoresist layer that shields high-energy ions, and 19 is high-energy ions. 5 is a heart-shaped pattern formed on the table surface 20. FIG. 6 is a character formed on the girdle part 21. FIG. 7 is an enlarged view of the character part of FIG.

Example

Hereinafter, the present invention will be described in detail based on examples, but the present invention is not limited to the following description examples unless it exceeds the gist. In the example described below, the xy chromaticity of the sample after ion irradiation was measured as follows.

1. X y chromaticity measurement method: Diamond particles, “JIS 7 8 16 (1 9 9 1), regular light source fluorescent lamp D 6 5 _ used for comparison of surface color _ format and performance” A D 65 standard light source and a color luminance meter (Koni force Minolta Co., Ltd., model: CS-220) are prepared, and white light from the standard light source is applied to the colored cut surface of the diamond particles created in the following example. The reflected light was measured with a color luminance meter. The same sample was measured 3 times and the average value was calculated.

[0033] [Example 1]

Brilliant-cut melee diamond particles with a maximum diameter of about 1 mm were fixed to an aluminum fixture with the structure shown in Fig. 2. This was placed in the irradiation chamber 9 of the ion accelerator shown in FIG. Put gold (A u) powder (average particle size: approx. 600 micrometers) into the cesium sputter ion source 2 in Fig. 1 and keep the acceleration energy constant at 3 MeV, and the ion irradiation dose is 1 X 1 0 ¹² and ^{~ 1 X 1 0 15 ions /} cm 2 range, the temperature of the diamond particles 2 00 ° C, irradiated with ions of vacuum degree as 1 0- ⁴ P a, relationship coloration ion irradiation amount I investigated. The results are shown in Table 1. As for the obtained sample, those with a small amount of ion irradiation exhibited a light brown color, and those with a large amount of ion irradiation exhibited a black color.

[0034] [Example 2]

In the example described in Example 1, the sample put in the ion source is changed to a powder of silicon (S i) (average particle size: about 650 micrometers), and the acceleration energy is constant at 3 MeV. the amount of irradiation, and ^{1 X 1 0 13 ~5 X 1} 0 14 ions / cm 2 range, temperature 200 ° C of the diamond particles, the degree of vacuum in the 1 0- ⁴ P a is irradiated with ions, ion irradiation The relationship between quantity and color was investigated. The results are shown in Table 1-1. In the obtained sample, those with a small amount of ion irradiation exhibited a light green color, and those with a large amount of ion irradiation exhibited a dark green color.

[0035] [Example 3]

In the example described in Example 1, the sample placed in the ion source is changed to carbon (C) powder (average particle size: 700 micrometers), the acceleration energy is constant at 3 MeV, and the ion irradiation dose is , 1 X 10 ^{13 to} 5 X 10 ¹⁴ ions / cm ² , ion irradiation with diamond particle temperature of 200 ° C and vacuum of 10- ⁴ Pa, ion irradiation dose The relationship between coloration and color was investigated. The results are shown in Table 1. It was described in 1. In the obtained sample, those with a small amount of ion irradiation exhibited a light green color, and those with a large amount of ion irradiation exhibited a dark green color.

[Example 4]

In the example described in Example 1, the sample put into the ion source was changed to a powder of boron (B) (average particle size: 1650 micrometers), and the acceleration energy was set to be constant 3 MeV. the amount of irradiation was irradiated in the range of ^{1 X 1 0 13 ~5 X 1} 0 14 ions / cm 2, the temperature of the diamond particles 2 0 0 ° C, a vacuum degree of 1 0 - set to ⁴ P a ion irradiation Then, the relationship between the ion irradiation amount and coloring was investigated. The results are shown in Table 1-1. As for the obtained sample, those with a small amount of ion irradiation exhibited a light yellowish green color, and those with a large amount of ion irradiation exhibited a yellowish green color.

[0037] [Table 1]

Table 1

[0038] From Table 1, the following becomes clear. 1. Even if the ion source is the same, the color of the resulting product can be changed by selecting (changing) the ion dose.

2. Even if the ion source is the same, it becomes darker when the ion dose is increased.

Industrial applicability

According to the production method of the present invention, colored diamond particles with low commercial value can be colored to produce colored diamond particles with high commercial value as jewelry, and arbitrary patterns can be drawn on the cut surface of diamond particles. This makes it possible to manufacture jewelry with a high commercial value with an original design. In addition, according to the manufacturing method of the present invention, patterns such as numbers and letters can be easily drawn on the cut surface of the diamond particle, so that the identification number, the manufacturer's logo, and the manufacturer's mark can be drawn on the diamond particle. It is possible and can be easily distinguished from fake brands by these drawings, which can increase customer confidence in diamond particles.

Claims

The scope of the claims

[1] A method for producing a colored diamond particles cut surface, the cut surface of the colored to Utosuru diamond particles, from room temperature to about 2 0 0 ° temperature range of ^{C, 1 0 - 3 ~ 1} 0 - 4 P In the vacuum atmosphere of a, by using an ion accelerator, high energy ions with acceleration energy in the range of "! ~ 5 MeV and ion irradiation in the range of 1 X 10 ¹² ~ 1 X 10 ¹⁵ ions / cm ² Irradiating, a method for producing diamond particles colored on a cut surface.

[2] The cut surface according to claim 1 is colored by changing the type of ion to be irradiated and changing the type of color at the time of coloring and the shade of the color after coloring by changing the ion irradiation amount. A method for producing diamond particles.

[3] In the method of manufacturing diamond particles with a pattern drawn on the cut surface, after the diamond particle cut surface is covered with a mask or photoresist mask that has holes or holes formed into letters or marks, temperature range of room temperature to about 2 0 0 ° C, 1 0 - 3 ~ 1 0 - 4 vacuum atmosphere of P a, the drilling hole, the range of 1 to 5 M e V acceleration energy by ion accelerator, ion irradiation A method for producing diamond particles having a pattern drawn on a cut surface, characterized by irradiating high-energy energy ions in a range of 1 X 10 ¹² to 1 X 10 ¹⁵ ions / cm ² .

[4] By changing the type of ions to be irradiated and changing the amount of ion irradiation, the type of pattern color to be drawn and the density of the pattern after drawing are changed. The pattern is drawn on the cut surface according to claim 3. Process for producing diamond particles.