JP2002036791A - Engraving needle for seal and method for forming hard coat on engraving needle for seal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To largely reduce friction resistance during engraving, and prevent an engraving needle from being broken during manufacturing of a seal, while drastically enhancing durability of an engraving needle for a seal. SOLUTION: A cutting blade part 13 set at a tip side of a main body part contacts and engraves a seal material. At least a base material 10 of the cutting blade part 13 consists of alloy tool steel or sintered hard alloy. On a surface of the cutting blade 13 a diamond-like carbon coat is formed through an intermediate layer 20 which enhances adhesion with the base material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engraving needle for a seal mounted on an automatic seal engraving machine for engraving a seal material such as ivory, buffalo, boxwood and plastic, and a method for forming a hard coating on the engraving needle for the seal. Things.

[0002]

2. Description of the Related Art Personal seals and company seals are printed on a seal material such as ivory, buffalo, boxwood, plastic, etc. by means of a seal engraving needle made of alloy tool steel or cemented carbide attached to a seal automatic engraving machine. It is made by engraving and marks. The tip of the engraving needle for a seal has a pyramid or cone shape, and the tip diameter or width is about 100 μm, and is very thin and easily broken. In some cases, a hard coating such as titanium carbide (TiC) or titanium nitride (TiN) is applied to the surface of the engraving needle for the purpose of increasing the durability of the engraving needle for seals.

[0003]

However, stamps are required to have high precision in engraving due to the specificity of the purpose of use, and also require elegance of the font. However, conventional engraving needles for seals have poor durability, and when engraving a two-character seal, the sharpness is reduced from about 60 to 80, and replacement of the engraving needle is required. The production efficiency of the seal was poor. If the engraving needle continues to be used in a state where the sharpness has deteriorated, the character of the engraved seal will vary, and it will not be possible to obtain an elegant and clear character seal.

In addition, the load on the engraving needle is increased due to poor sharpness, and the tip of the engraving needle may be broken. For this reason, there is a risk that the broken pieces may fly and cause injury, and that the stamp material being engraved becomes unusable. In addition, an engraving needle for seals whose surface is coated with a hard coating of TiC or TiN cannot provide a sufficient wear resistance effect unless the coating thickness is 5 μm or more, so that the coating is formed to a thickness of 5 μm or more. I'm using
As a result, the width of the engraving was widened, and the character of the engraved seal was thin, which was not satisfactory.

Further, since the hard coating is formed by dry plating, the surface roughness of the hard coating is rough, so that the cutting load is greater when engraving the seal material, and the engraving needle is more heavily applied than the uncoated one. Many of them had broken tips. The present invention has been made to solve such a problem, and significantly improves the durability of the engraving needle for seals and greatly reduces the frictional resistance at the time of engraving, thereby improving the production efficiency of the seals. It is another object of the present invention to improve the font accuracy of a carved seal and to produce an elegant and clear font stamp.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides the following engraving needle for seal stamp and a method for forming a hard coating on the engraving needle for seal stamp. The seal stamp engraving needle according to the present invention is attached to a seal stamp automatic engraving machine,
An engraving needle made of an alloy tool steel or cemented carbide material for engraving a seal material such as buffalo, boxwood, plastic, etc. The diamond-like carbon film is formed via an intermediate layer that enhances adhesion.

The shape of at least the portion of the surface of the engraving needle that comes into contact with the seal material is substantially triangular pyramid or approximately square pyramid.
Further, it is preferable that the tip is a plane having an inclination in a range of 2 ° to 8 ° with respect to the center axis. Alternatively, the shape of at least the portion of the surface of the engraving needle that comes into contact with the seal material may be substantially conical, and a part of the surface in the circumferential direction may be cut off in a plane parallel to the central axis.

The intermediate layer is made of silicon, tungsten,
It may have a one-layer structure formed of any one of titanium carbide, silicon carbide, and chromium carbide. Or,
It is more preferable that the intermediate layer has a two-layer structure including a lower layer mainly composed of chromium or titanium and an upper layer mainly composed of silicon or germanium. Further, the intermediate layer may have a two-layer structure of a lower layer mainly composed of titanium and an upper layer mainly composed of any of tungsten, tungsten carbide, silicon carbide and titanium carbide.

Further, the intermediate layer may have a three-layer structure of a lower layer mainly composed of titanium, an intermediate layer mainly composed of titanium carbide or silicon carbide, and an upper layer mainly composed of carbon. The diamond-like carbon film formed on the surface of the engraving needle at least in contact with the seal material through these intermediate layers has a surface roughness Ra of 0.2 to 0.02 μm. Is desirable.

The method of forming a hard coating on a seal stamp engraving needle according to the present invention is a method for mounting a seal film engraving needle on an automatic seal stamp engraving machine for engraving a seal material such as ivory, buffalo, boxwood, plastic or the like from alloy tool steel or cemented carbide material. A method of forming a hard coating on a seal engraving needle, comprising the following steps.

A step of setting and exhausting the engraving needle for a seal stamp in which the portion to be contacted with the seal stamp material has been formed and washed, and introducing argon into the exhausted vacuum tank to ionize the silicon, silicon, An intermediate layer forming step of forming an intermediate layer on at least a portion of the surface of the engraving needle that is in contact with the seal material by a sputtering process using any one of tungsten, titanium carbide, silicon carbide, and chromium carbide; Discharging argon in the vacuum chamber and introducing a gas containing carbon into the vacuum chamber, generating plasma in the vacuum chamber, and forming a diamond-like carbon film on the surface of the intermediate layer by plasma CVD. Forming,

Instead of the above-mentioned intermediate layer forming step, argon is introduced into the evacuated vacuum chamber to be ionized, and sputtering is performed using chromium or titanium as a target.
A first intermediate layer forming step of forming a lower layer of an intermediate layer mainly composed of chromium or titanium on at least a portion of the surface of the engraving needle which is in contact with the seal material, and subsequent to this step, silicon or germanium is targeted. A second intermediate layer forming step of forming an upper layer of an intermediate layer mainly composed of silicon or germanium on the lower layer by a sputtering process may be performed to form two intermediate layers.

Alternatively, instead of the above-mentioned intermediate layer forming step,
By introducing argon into the evacuated vacuum chamber and ionizing it, sputtering using titanium as a target,
A first intermediate layer forming step of forming a lower layer of an intermediate layer mainly composed of titanium on at least a portion of the surface of the engraving needle that is in contact with the seal material, and, following the step, a sputtering process using tungsten as a target, A second intermediate layer forming step of forming an upper layer of an intermediate layer mainly composed of tungsten on the lower layer may be performed to form two intermediate layers.

In addition, argon is introduced into the evacuated vacuum chamber to ionize it, and a sputtering process using titanium as a target is performed so that at least a portion of the surface of the engraving needle that comes into contact with the seal material forms an intermediate layer mainly composed of titanium. A first intermediate layer forming step of forming a lower layer, and following this step,
A second intermediate layer that forms an upper layer of an intermediate layer mainly composed of tungsten carbide or silicon carbide on the lower layer by a reactive sputtering process in which a gas containing carbon is introduced into the vacuum chamber and a tungsten or silicon target is used. The formation step may be performed to form two intermediate layers.

Alternatively, argon is introduced into the evacuated vacuum chamber to ionize it, and sputtering is performed using titanium as a target. A first intermediate layer forming step of forming a lower layer, and subsequent to this step, a gas containing carbon is introduced into the vacuum chamber, and titanium carbide is formed on the lower layer by a reactive sputtering process targeting titanium or silicon. Or a second intermediate layer forming step of forming an intermediate layer mainly composed of silicon carbide, and subsequently, the sputtering amount of titanium or silicon of the target is gradually reduced, and carbon is mainly deposited on the intermediate layer. And a third intermediate layer forming step of forming an upper layer described above may be performed to form three intermediate layers.

In the method of forming a hard coating on an engraving needle for a seal, after the step of forming the diamond-like carbon coating, the surface of the diamond-like carbon coating formed in the step is finish-polished by polishing and lapping. It is desirable to carry out the step of performing.
The polishing and lapping in the final polishing step may be performed using a diamond paste or an alumina paste in which diamond particles or alumina particles having a particle diameter of 0.1 to 4 μm are scattered.

[0017]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. [Embodiment of Engraving Needle for Seal] FIG. 1 is a view of a first embodiment of the present invention, in which an engraving needle for seal has been set up, (A) is a plan view, and (B) is a front view. FIG.

In the engraving needle 1 for seal, a conical portion 12 is formed on the distal end side of an elongated cylindrical main body portion 11, and a pyramid-shaped cutting blade portion 13 is further formed on the distal end portion. These are made entirely of alloy tool steel (also called high-speed steel) or cemented carbide (also called cemented steel), or the cutting blade 13
Is formed of alloy tool steel or cemented carbide, the main body portion 11 and the conical portion 12 are formed of another metal such as SK steel or stainless steel, and the cutting edge portion 13 is formed of the conical portion 12 May be adhered to the tip end surface by brazing or the like. A flat distal end surface 13a is formed at the distal end of the cutting blade portion 13, the details of which will be described later.

In this example, the total length a of the seal engraving needle 1 is 3
5 mm, the length of the cutting edge 13 is 1.2 mm, the diameter of the main body 11 is about 3.0 mm, and the cone angle α of the conical portion 12 and the cutting edge 13 is 20 °. The cutting blade 13 is formed as shown in FIG. 2 and FIG. 2A is a front view of the cutting blade portion 13 viewed from the long side of the distal end surface 13a, FIG. 2B is a side view of the cutting blade portion 13 viewed from the short side, and FIG. 3 is a circumscribed circle of the distal end surface 13a. It is a top view shown with.

The cutting edge 13 has a front end surface 13a as shown in FIG.
As shown in FIG. 2, the shape is a parallelogram quadrangular pyramid, and as shown in FIG. This angle β is preferably in the range of 2 ° to 8 °,
In this example, the optimum angle is set to 5 °.

The tip surface 13a of the cutting blade 13
Has a diameter φ of a circumscribed circle indicated by a two-dot chain line in FIG.
0.40 mm (preferably 0.34 mm to 0.3 mm
6 mm), a length d of 0.2 mm to 0.5 mm (preferably about 0.3 mm), and a width e of (0.1 mm to 0.3 mm).
mm (preferably about 0.2 mm), and a tilt angle γ with respect to a direction orthogonal to the long side of the short side.
Is 0 ° to 20 ° (preferably about 5 ° to 10 °. The heights of the four corners are all different. In the example shown in FIG. 3, the corner p is the highest and the corner s is Is the lowest, and the corner points q and r have intermediate heights.

However, the above-mentioned numerical values are merely examples, and can be variously changed in accordance with the type of the seal stamp engraving machine to which the seal stamp engraving needle 1 is attached and the material of the seal stamp material. This seal engraving needle 1 is attached to a seal automatic engraving machine, and a seal material such as ivory, buffalo, boxwood, plastic, etc. is engraved to engrave the first and last names. At that time, the cutting blade 13 comes into contact with the seal material. It is the part to carve it.

Therefore, as shown in FIG. 4, an intermediate layer for increasing the adhesion to the surface of the base material 10 made of alloy tool steel or cemented carbide is provided on at least the surface of the cutting blade 13 of the engraving needle 1 for seals. A diamond-like carbon film (hereinafter, abbreviated as “DLC film”) 30 is formed via 20.

The DLC film 30 is also called a diamond-like thin film, a hard carbon film, a hydrogen amorphous carbon film, an i-carbon film, etc., and is an amorphous carbon thin film having a structure and properties very similar to diamond. ,
It has Vickers hardness of 2000 kg / mm2 or more, and has high wear resistance due to high hardness, low friction coefficient, lubricity, and high corrosion resistance.

The intermediate layer 20 is at least one thin film layer provided to enhance the adhesion between the DLC film 30 and at least the surface of the base material 10 of the cutting edge portion 13. (Si), tungsten (W), titanium carbide (TiC), silicon carbide (silicon carbide: S
iC) or chromium carbide (CrC).

As described above, at least the surface of the cutting blade portion 13 of the seal engraving needle 1 is provided with the DLC film 30 through the intermediate layer 20.
Is formed, the DLC film 30 is firmly formed on the surface of the base material 10 of the cutting blade 13 with good adhesion. Therefore, even if polishing or lapping is performed to further smooth the surface of the formed DLC film 30, it does not peel off. Also, even if internal stress or the like due to heat and pressure is generated during use of the seal engraving needle 1, the DLC film 30
Does not peel off.

Accordingly, the seal engraving needle 1 has a significantly improved durability as compared with the conventional one, and is attached to an automatic seal engraving machine to engrave seal materials such as ivory, buffalo, boxwood and plastic. The frictional resistance (load resistance) at the time of producing the seal is greatly reduced, and the cutting blade 13 does not break. Therefore, it is possible to continuously produce an elegant and clear character stamp with high precision without replacing the engraving needle for a long period of time. In addition, in the seal engraving needle 1 of this embodiment, the shape of the cutting blade 13 is substantially quadrangular pyramid, but the shape of the cutting blade may be substantially triangular pyramid.

Next, a second example of the seal engraving needle according to the present invention will be described.
Will be described with reference to FIGS. 5 to 7. FIG. FIG. 5 is a plan view of the seal engraving needle in a horizontal position, FIG. 6 is a front view thereof, and FIG. 7 is a left side view thereof (view from the front end side). The engraving needle 1 ′ for a seal has a cylindrical main body 11 ′ and a cutting blade 15, which forms a part of a cone, integrally formed of a base material of an alloy tool steel or a super steel alloy.

The cutting blade portion 15 of the seal engraving needle 1 '
A plane 1 in which about 2/3 of the circumference of the cone is parallel to the central axis 16
This is the shape cut off at 5a. The amount of the cut is preferably a part in the circumferential direction, preferably 1/2 to 2/3. In the illustrated example, the total length f of the seal engraving needle 1 ′ is 121 mm,
The diameter D 'of the main body 11' is 3.16 mm, and the cutting edge 15
Has a length g of 12 mm and a width h of the tip of the cutting blade 15 of 0.
Although it is 1 mm, these values can of course be variously changed.

In this seal engraving needle 1 'as well, the cutting blade portion 15 is a portion which comes into contact with the seal material and engraves it, and at least the surface of the cutting blade portion 15 enhances the adhesion to the base material. The DLC film is formed via the intermediate layer. Needless to say, a DLC film may be formed on the entire surface of the engraving needle 1 'for seal.

[Structure of Intermediate Layer] Next, various examples of the structure of the intermediate layer 20 will be described with reference to FIGS. These figures show the cutting blade 13 of the above-described seal engraving needle 1 or 1 '.
Or, a large part of the surface near 15 is greatly enlarged to
FIG. 3 is a schematic diagram illustrating a configuration of a C film 30 and an intermediate layer 20.

FIG. 8 shows at least the cutting blade 13 or 15
10 made of alloy tool steel or super-steel alloy constituting
A DLC film 30, which is a hard film, is formed on the surface 10a of FIG.
The intermediate layer is made of silicon (Si), tungsten (W), titanium carbide (TiC), silicon carbide (SiC),
It is formed to have a thickness of about 0.1 μm by using one of chromium carbide (CrC). The DLC film 30 has a thickness of 0.1 μm.
m to about 0.5 μm.

FIG. 9 shows an example in which an intermediate layer having a two-layer structure is formed. An intermediate layer 20 composed of a lower layer 21 and an upper layer 23 is formed on the surface 10a of the base material 10 of the cutting blade portion. A DLC film 30 is formed. The lower layer 21 is chrome
(Cr) or titanium (Ti) is mainly formed to a thickness of about 0.1 μm, and the upper layer 23 is mainly formed of silicon (Si) or germanium (Ge) to a thickness of about 0.1 μm.

In this case, the chromium or titanium in the lower layer 21 of the intermediate layer 20 can be formed with good adhesion to the base material 10 made of the alloy tool steel or the super steel alloy constituting the cutting edge 13 or 15. Further, silicon or germanium of the upper layer 23 is a Group IVb element in the periodic table that is the same as carbon constituting the DLC film 30, and each has a diamond structure. Therefore, the upper layer 23 and the DLC film 30 are covalently bonded to each other with high adhesion. In addition, chromium or titanium of the lower layer 21 and silicon or germanium of the upper layer 23 can be formed into a film with good adhesion.

For this reason, by forming the DLC film 30 on the surface 10a of the base material 10 with the intermediate layer 20 having such a configuration, the DLC film 30 can be formed with a stronger adhesion force, The durability of the part can be dramatically increased.

FIG. 10 shows another example of the intermediate layer having a two-layer structure. In this example, a lower layer 21 mainly composed of titanium (Ti), tungsten (W), tungsten carbide (WC), and silicon carbide (Si) are formed on the surface 10a of the base material 10 of the cutting blade.
An intermediate layer 20 having a two-layer structure with an upper layer 23 mainly composed of any one of C) and titanium carbide (TiC) is formed, and a DLC film 30 is formed on the upper layer 23. The lower layer 21 and the upper layer 23 of the intermediate layer 20 are each formed to a thickness of about 0.1 μm, and the DLC film is formed to a thickness of about 0.1 μm to 0.5 μm. Even in this case, the same adhesion of the DLC film 30 as in the example shown in FIG. 9 can be obtained.

FIG. 11 shows an example in which an intermediate layer having a three-layer structure is formed. In this example, the surface 10a of the base material 10 of the cutting blade portion
First, a lower layer 21 mainly composed of titanium (Ti) is formed as an intermediate layer 20, and titanium carbide (TiC) is formed thereon.
Alternatively, an intermediate layer 22 mainly composed of silicon carbide (SiC) is formed, and an upper layer 23 mainly composed of carbon (C) is further formed thereon. Then, a DLC film 30 is formed on the upper layer 23.

In this case, the lower layer 21, the middle layer 22, and the upper layer 23
Are not clearly different layers, and the concentration of titanium is highest in the portion of the lower layer 21 adjacent to the base material 10, the concentration gradually decreases toward the upper layer 23, and the DLC film 3 of the upper layer 23
In the portion adjacent to zero, the concentration of carbon is highest,
A gradient structure may be used in which the concentration gradually decreases toward. Rather, such an inclined structure can enhance the adhesion of the DLC film 30.

The DLC film 3 formed by each of these examples
In the case of No. 0, the surface is preferably polished and wrapped to have a mirror finish with a surface roughness Ra of about 0.2 to 0.02 μm.

[Evaluation of abrasion resistance by abrasion test] Here, abrasion tests were performed on test pieces having the same film configuration as the mold according to the present invention and the conventional mold, and the results were compared. The abrasion resistance was evaluated. The abrasion tester used here is a wear tester of the brand name NUS-ISO-2 of Suga Test Instruments Co., Ltd.

The method of abrasion test by this abrasion tester is as follows.
This will be described with reference to FIG. As shown in FIG. 12, the test piece 92 on which the film was formed was placed with its film-forming surface side facing down.
The test piece holding plate 93 and the test piece holding screw 95 are used to fix the test piece mounting base 93 to the opening. Furthermore, the wear wheel 9
1. Abrasive paper (not shown) is attached to 1. This wear wheel 91
Then, an upward load such that the abrasive paper is pressed against the test piece 92 by a balance mechanism (not shown) is applied.

Then, the test piece mounting table 93 is reciprocated by a mechanism for converting the rotational movement of the motor (not shown) into a reciprocating movement, and the worn wheel 91 is further moved to the position of the test piece mounting table 93.
Rotate in the direction of the arrow at an angle of 0.9 ° for each reciprocation. As a result, the test piece 92 always comes into contact with a new unworn area of the abrasive paper attached to the wear wheel 91. The number of reciprocations of the test piece mounting table 93 can be automatically set, and the abrasion tester automatically stops at the set number of times.

The test piece 92 used here had a thickness of 1 as an alloy tool steel used for a seal engraving needle as a base material.
mm, and the surface thereof has a surface roughness Ra = 0.
It is polished to a thickness of 05 μm to 0.5 μm. Then, as a test piece corresponding to the seal engraving needle according to the present invention, a lower intermediate layer made of titanium and an upper intermediate layer made of silicon on the surface of the base material, each having a thickness of 0.1.
A test piece 92A having a thickness of 0.5 μm and a DLC film having a thickness of 0.5 μm provided thereon was used. As a comparison with the conventional engraving needle for seals, a DLC film having a thickness of 0.5 μm directly formed on the substrate of the test piece (referred to as a test piece 92B) was used.

Further, as the abrasive paper to be attached to the wear wheel 91, SiC of mesh No. 600 was used, the contact load between the abrasive paper and the test piece 92 was 830 g, and the number of reciprocating movements of the test piece mounting table 93 was 200. As a condition of the number of times, a wear test of the coating of the test piece 92A and the test piece 92B was performed.
As a result of the abrasion test, the test piece 92A having the coating structure according to the present invention hardly peeled off the coating, and the surface state of the DLC film did not change even after the test. On the other hand, in the test piece 92B having the conventional coating structure, the DLC film was peeled off, and the substrate on the surface of the test piece could be visually observed.
It was found that the LC film was peeled off.

The difference between the coating structures of the test pieces 92A and 92B is that the DLC film is formed on the surface of the base material through two intermediate layers or the DLC film is formed directly on the surface of the base material. It is a point. From the results of the wear test, it was found that the provision of the two intermediate layers strengthened the adhesion of the DLC film and significantly improved the wear resistance of the film.

On the surface of the base material, a single intermediate layer made of any one of silicon, tungsten, titanium carbide, silicon carbide, and chromium carbide is formed to a thickness of about 0.1 μm, and a thickness of about 0.1 μm is formed thereon. Test pieces on which a DLC film of about 0.5 μm was formed were prepared, and abrasion tests were performed on the test pieces under the same conditions as above. In each case, as in the case of the test piece 92A, the number of reciprocating motions was 200 times. Then D
The surface state of the LC film hardly changed. Therefore, even with the provision of one intermediate layer, the adhesion of the DLC film is strengthened, and the wear resistance of the coating is significantly improved.
It turned out that there was no problem in practical use.

[Evaluation of Surface Properties by Scratch Test] Next, the mechanical properties of the coating film were obtained by performing a scratch test on various samples corresponding to the seal engraving needle according to the present invention and the conventional seal engraving needle. (Especially abrasion resistance) was evaluated. The measuring instrument used for this scratch test was HEI
It is a surface property measuring device of DON-14 type.

According to the scratch test using this surface property measuring device, the surface properties of the film can be evaluated by measuring the resistance generated at the time of scratching. Therefore, five types of samples (A) to (E) described below were prepared,
The resistance generated at the time of scratching was measured using the surface property measuring device. The base material of each of these samples is an alloy tool steel used for an engraving needle for seals, and its surface is polished.

(A) A DLC film directly formed on the surface of a substrate. (B) A DLC film formed on the surface of a base material via an intermediate layer of titanium carbide (TiC). (C) A structure in which a DLC film is formed on the surface of a base material via an intermediate layer made of silicon carbide (SiC). (D) DLC on the surface of the base material via a lower intermediate layer of titanium (Ti) and an upper intermediate layer of silicon (Si)
What formed the film. (E) DL on the surface of the base material via a lower intermediate layer of titanium (Ti) and an upper intermediate layer of silicon carbide (SiC).
Formed with C film. (F) A structure in which a DLC film is formed on the surface of a base material via a lower intermediate layer of titanium (Ti), an intermediate intermediate layer of silicon carbide (SiC), and an upper intermediate layer mainly composed of carbon.

The thickness of the DLC film is 0.5 μm for each sample, and the thickness of each intermediate layer made of titanium carbide, silicon carbide (silicon carbide), titanium, and silicon (silicon) is zero. .1 μm. Measurement of the surface properties of the coating using a surface property measuring instrument was conducted when the tip angle was 9
A diamond indenter having a tip curvature radius of 50 μm at 0 ° was used, the scratching speed was 30 mm / min, and the scratching load was changed every 10 gr from 10 gr to 500 gr.

FIG. 13 is a graph showing the relationship between the scratch load and the scratch resistance as the measurement results. In addition, the diagram of FIG. 13 shows that the scratch load is changed from 10 gr to 10 gr.
The resistance value (gr) due to scratch resistance at that time is measured and plotted, and the average value is graphed by approximating the average value with a straight line. That is, the vertical axis shows the resistance value due to the scratch resistance, and the horizontal axis shows the scratch load. Curves A, B, C, D, E, and F indicate measurement results of the samples (A) to (F), respectively. In addition,
Curves E and F were almost the same.

As is apparent from FIG. 13, when the scratch load exceeds a certain value, the resistance force changes rapidly. The phenomenon that the inflection point occurs in the characteristic curve is that at a critical load below this inflection point, the indenter simply shows frictional flow, and the scratch resistance value increases linearly with the increase in load, It is considered that when the critical load is exceeded, the DLC film formed on the substrate has cracks.
Then, due to the generated crack, the scratch resistance value shows a sharp increase, and the coefficient of friction increases. Thus, FIG.
The adhesion of the coating to the substrate can be evaluated by the value of the critical load, which is the inflection point of the characteristic curve.

As shown in FIG. 13, the critical load in the case of the conventional sample (A) in which the DLC film is formed directly on the substrate is 80 gr. On the other hand, a sample (B) having a film structure having one intermediate layer corresponding to the embodiment of the invention
The critical load in the case of (c) is 180 gr, the critical load in the case of the sample (C) is 220 gr, and the critical load in the case of the sample (D) having a film structure having two intermediate layers is 350 gr, the samples (E) and ( The critical load in case F) is 380 gr. That is, in the engraving needle for seals according to the present invention, the DLC film is formed with twice or more adhesion force than the conventional engraving needle for seals.

[Embodiment of Method for Forming Hard Coating] Next, a method for forming a hard coating on at least the cutting blade portion of the engraving needle for seals according to the present invention will be described with reference to FIGS. In the example described below, the first
A case in which a DLC film is formed on almost the entire surface of the engraving needle 1 for seals of the embodiment with an intermediate layer interposed therebetween will be described.

First, an intermediate layer forming step of forming the above-described intermediate layer 20 on the surface of the base material of the engraving needle for seal 1 will be described with reference to FIG. FIG. 14 is a sectional view of a sputtering apparatus used for forming an intermediate layer. As shown in this figure, a vacuum chamber 5 having a gas introduction port 53 and an exhaust port 54
A target holder 56 is fixed in the vicinity of one wall surface in 1, and a target 55, which is a material of the intermediate layer, is set (arranged) there.

In the vacuum chamber 51, the engraving needle 1 for a seal which is made of a base material of alloy tool steel or cemented carbide, and in which the cutting blade portion 13 has been formed and washed, is placed in the vacuum chamber 51.
5 is set (arranged) so as to face 5. The seal engraving needle 1 is connected to a DC power supply 58, and the target 55 is connected to a target power supply 57. Although not shown, a shutter that can be opened and closed is provided between the target 55 and the seal engraving needle 1 at a position where the target 55 is covered and a position where the target 55 is exposed. The shutter is initially set at a position covering the target 55.

Then, the degree of vacuum in the vacuum chamber 51 is reduced to 4 × 10 ⁻³ Pascal (3 × 10 ⁻⁵ ) by an exhaust means (not shown).
torr) Vacuum exhaust through the exhaust port 54 so as to be as follows. Thereafter, an argon (Ar) gas is introduced as a sputtering gas from the gas inlet 53 to adjust the degree of vacuum in the vacuum chamber 51 to 4 × 10 ⁻¹ Pascal (3 × 10 ⁻³ torr).

Thereafter, a negative DC voltage of −50 V is applied to the seal engraving needle 1 from the DC power supply 58. A DC voltage of −500 V to −600 V is applied to the target 55 from the target power supply 57.
Then, plasma is generated inside the vacuum chamber 51, and the surface of the base material of the engraving needle 1 for seal is ion bombarded with ionized argon to remove an oxide film and the like formed on the surface.

Next, a shutter (not shown) is opened to expose the target 55, and the surface of the target 55 is sputtered by argon ions in the plasma. If the target 55 is silicon, the silicon molecules beaten out from the surface adhere to the surface of the base material of the engraving needle 1 for stamping, thereby forming an intermediate layer made of a silicon film.
This intermediate layer forming step is performed so that the intermediate layer is formed to a predetermined film thickness by the sputtering process.

When the single intermediate layer 20 shown in FIG. 8 is formed, silicon, tungsten, titanium carbide, silicon carbide (silicon carbide),
Then, any one of chromium carbide and chromium carbide is set, and the above-described sputtering treatment is performed. Thereby, the silicon film, the silicon film, and the like on the surface of the substrate including the cutting blade portion 13 of the seal engraving needle 1 are provided.
The intermediate layer 20 is formed of any one of a tungsten film, a titanium carbide film, a silicon carbide (silicon carbide) film, and a chromium carbide film.

When an intermediate layer of a titanium carbide film or a silicon carbide film is formed, the following method can be employed. That is, titanium or silicon (silicon) is set as the target 55, and sputtering by argon ions is performed, and at the same time, methane (CH ₄ ) gas, for example, as a gas containing carbon is introduced from the gas inlet 53 to perform sputtering. By reactive sputtering process with titanium or silicon molecules and carbon in gas,
An intermediate layer 20 of a titanium carbide film or a silicon carbide film is formed on the surface of the substrate of the engraving needle 1 for seal.

In the case of forming the two intermediate layers 20 composed of the lower layer 21 and the upper layer 23 shown in FIG.
1, two target holders 56 and a shutter for each of them are provided.
Set chromium or titanium as the target 55,
Silicon or germanium is set as the target 55 in the other target holder 56.

In the first intermediate layer forming step, first, only the shutter on the side of the target holder 56 on which chromium or titanium is set as the target 55 is opened to perform a sputtering process, and the base material of the engraving needle 1 for seal stamp is formed. Lower layer 21 made of a film mainly composed of chromium or titanium on the surface
Is formed to a thickness of about 0.1 μm. Subsequently, in the second intermediate layer forming step, only the shutter on the side of the target holder 56 on which silicon or germanium is set as the target 55 is opened to perform sputtering processing, and a film mainly composed of silicon or germanium is formed on the lower layer 21. Is formed to a thickness of about 0.1 μm.

Further, the lower layer 21 and the upper layer 2 shown in FIG.
Similarly, when forming two intermediate layers 20 composed of 3
Two target holders 56 and a shutter for each of them are provided in the vacuum chamber 51, titanium is set as the target 55 in one of the target holders 56, and tungsten, tungsten carbide, One of silicon carbide and titanium carbide is set.

First, in the first intermediate layer forming step, only the shutter on the side of the target holder 56 on which titanium is set as the target 55 is opened to perform a sputtering process, so that the surface of the base material of the engraving needle 1 for seal is formed on the surface of the base material. Is formed to a thickness of about 0.1 μm.

Subsequently, in a second intermediate layer forming step,
Only the shutter on the side of the target holder 56 on which any one of tungsten, tungsten carbide, silicon carbide, and titanium carbide is set as the target 55 is opened to perform a sputtering process.
Upper layer 23 made of a film mainly containing any of tungsten carbide, silicon carbide and titanium carbide is formed to a thickness of about 0.1 μm.

Alternatively, after forming the lower layer 21 of an intermediate layer mainly composed of titanium on the surface of the base material of the engraving needle 1 for stamping by the first intermediate layer forming step, in the second intermediate layer forming step, Only the shutter on the side of the target holder 56 on which tungsten or silicon is set as the target 55 is opened, and a gas containing carbon, for example, methane (CH ₄ ) gas is introduced into the vacuum chamber 51 so that the sputtered tungsten or silicon molecules are removed. An upper layer 2 of an intermediate layer mainly composed of tungsten carbide or silicon carbide is formed on the lower layer 21 by reactive sputtering with carbon in the gas.
3 can also be formed.

Further, the lower layer 21 and the middle layer 2 shown in FIG.
In the case where the three intermediate layers 20 composed of the second layer 23 and the upper layer 23 are formed, and when the intermediate layer 22 is formed of a film mainly composed of silicon carbide, two target holders 56 in the vacuum chamber 51 , A titanium is set as a target 55 in one target holder 56, and silicon is set as a target 55 in the other target holder 56.

First, in the first intermediate layer forming step, only the shutter on the side of the target holder on which titanium is set as the target 55 is opened to perform sputtering, and titanium is mainly applied to the surface of the base material of the engraving needle 1 for seal stamp. The lower layer 21 is formed of a film to be formed. Subsequently, in the second intermediate layer forming step, only the shutter on the target holder side in which silicon is set as the target 55 is opened, and a gas containing carbon, for example, methane (CH ₄ ) gas is introduced into the vacuum chamber 51. An intermediate layer 22 of a film mainly composed of silicon carbide is formed on the lower layer 21 by a reactive sputtering process using sputtered silicon molecules and carbon in the gas.

Thereafter, in a third intermediate layer forming step, the shutter (not shown) in the vacuum chamber 51 is gradually closed to reduce the amount of silicon exposed as the target 55, thereby gradually reducing the amount of silicon sputter. An upper layer 23 mainly composed of carbon whose carbon ratio is gradually increased is formed on 22. When the intermediate layer 22 is made of a film mainly composed of titanium carbide, the target holder 56 and the shutter in the vacuum chamber 51 may be a single set. Each step may be performed in the same manner as in the third intermediate layer forming step. However, there is no need to switch the opening and closing of the two shutters between the first intermediate layer forming step and the second intermediate layer forming step.

Next, the engraving needle 1 for a seal stamp having the intermediate layer 20 formed on at least the substantially entire surface of the base material including the cutting edge portion 13 by the various intermediate layer forming steps as described above.
The step of forming the DLC film 30 thereon will be described with reference to FIGS. That is, there are three types of DLC film forming methods as the process of forming the DLC film.

First, a first DLC film forming method will be described with reference to FIG. FIG. 15 is a sectional view of a plasma CVD apparatus used for that purpose. This first DLC film forming method uses a vacuum chamber 61 having a gas inlet 63 and an exhaust port 65 and having an anode 79 and a filament 81 above the inside. Then, the seal engraving needle 1 having the intermediate layer 20 formed on substantially the entire surface of the base material including the cutting blade 13 in the above-described intermediate layer forming step is disposed in the vacuum chamber 61. A member supporting the engraving needle 1 for seal is not shown.

The degree of vacuum in the vacuum chamber 61 is 4 ×
Vacuum is exhausted from the exhaust port 65 by exhaust means (not shown) so that the pressure becomes 10 ⁻³ Pascal (3 × 10 ⁻⁵ torr) or less. After that, benzene (C ₆ H ₆ ) is introduced into the vacuum chamber 61 as a gas containing carbon from the gas inlet 63,
The pressure in the vacuum chamber 61 is set to 6.67 × 10 ^-1 Pascal (5
× 10 ⁻³ torr). Furthermore, a DC voltage is applied to the seal engraving needle 1 from the DC power supply 73, a DC voltage is applied to the anode 79 from the anode power supply 75, and an AC voltage is applied to the filament 81 from the filament power supply 77.

At this time, the DC voltage applied from the DC power supply 73 to the engraving needle 1 for seal is -3 kV, the DC voltage applied from the anode power supply 75 to the anode 79 is +50 V, and the voltage applied from the filament power supply 77 to the filament 81. Is an AC voltage of 10 V so that a current of 30 A flows. As a result, plasma is generated in the area around the engraving needle 1 for seal in the vacuum chamber 61, and the plasma CV is generated.
D process, the intermediate layer 20 on the substrate of the engraving needle 1 for seal
(In the case of a multilayer intermediate layer, the upper layer 23)
A film can be formed. This DLC film has a thickness of 0.
The thickness is formed from 1 μm to 0.5 μm.

For convenience of explanation, the vacuum tank 51 used in the intermediate layer forming step and the vacuum tank 61 used in the DLC film forming step have been described separately, but these steps are performed using the same vacuum tank. It can be performed continuously. In that case, after the intermediate layer forming step is completed, argon in the vacuum chamber is exhausted and a gas containing carbon is introduced.

Next, a second DLC film forming method will be described with reference to FIG. Sixteenth is a sectional view of a plasma CVD apparatus used for that. When the apparatus shown in FIG. 16 is used, the engraving needle 1 for stamping with the intermediate layer 20 is arranged in a vacuum chamber 61 having a gas inlet 63 and an exhaust port 65. The vacuum degree is 4 × 10 ⁻³ Pascal (3 × 10 3
^The air is evacuated from the exhaust port 65 so that the pressure becomes ⁻⁵ torr) or less.

Thereafter, methane gas (CH ₄ ) as a gas containing carbon is introduced into the vacuum chamber 61 from the gas inlet 63 so that the degree of vacuum becomes 13.33 Pascal (0.1 torr). Then, radio frequency power (radio frequency power) is applied to the seal engraving needle 1 from the high frequency power source 69 having an oscillation frequency of 13.56 MHz via the matching circuit 67. As a result, plasma is generated around the seal engraving needle 1, and the intermediate layer 20 (the upper layer 23 in the case of a multilayer intermediate layer) formed on the base material of the seal engraving needle 1 by the plasma CVD process. A DLC film can be formed on the surface.

Next, a third DLC film forming method will be described with reference to FIG. FIG. 17 is a sectional view of a plasma CVD apparatus used for the apparatus. In the case of using the apparatus shown in FIG. 17, the seal engraving needle 1 on which the intermediate layer 20 is formed is arranged in a vacuum chamber 61 having a gas inlet 63 and an exhaust port 65. , Vacuum chamber 6
The degree of vacuum in 1 is 4 × 10 ⁻³ Pascal (3 × 10 ⁻⁵ to
rr) Vacuum exhaust from the exhaust port 65 so as to be below.

Thereafter, methane gas (CH ₄ ) as a gas containing carbon is introduced into the vacuum chamber 61 from the gas inlet 63 so that the degree of vacuum is 13.33 Pascal (0.1 torr). Then, a DC voltage of minus 600 V is applied from the DC power supply 83 to the seal engraving needle 1 to generate plasma around the engraving needle 1, and the intermediate layer formed on the base material of the seal engraving needle 1 by plasma CVD processing. A DLC film can be formed on the surface of the layer 20 (the upper layer 23 in the case of a multilayer intermediate layer).

In the case of these DLC film forming methods, the same vacuum chamber as that for the intermediate layer forming step can be used, and the method can be performed continuously with the intermediate layer forming step. In that case, after the intermediate layer forming step is completed, argon in the vacuum chamber is exhausted and a gas containing carbon is introduced. In the case where the DLC film is formed by the method described with reference to FIGS.
Although an example in which methane gas or benzene gas is used as the gas containing carbon has been described, a gas containing carbon such as ethylene in addition to methane, or a vapor of a liquid containing carbon such as hexane can also be used.

In the above-described intermediate layer forming step and DLC film forming step, for simplicity, only one engraving needle 1 for stamping is set in the vacuum chamber 51 or 61 to form a film. A large number of engraving needles for seals are set on a jig, placed in a vacuum chamber, and the film is formed while rotating the needle.

FIG. 18 shows an example of a jig used for this purpose. The jig 100 includes a disk 101 and a large number of support shafts 103 penetrating the same circumference at equal angular intervals, and a small disk-shaped engraving needle holding plate 102 supported on each of the support shafts 103 in a plurality of stages. And A plurality of columns 108 are fixed on the disk 101, and the insulator 1 is provided at the upper end thereof.
09 supports the metal disk 120.

The lower part of each support shaft 103 is electrically insulated and fixed by insulators 121 and fixed.
The disk 101 is insulated from the disk 101 and is rotatable relative to the disk 101 so as not to move in the axial direction. The upper end of each support shaft 103 is rotatably supported by a metal disk 120 via a bearing 122. i On the upper surface of each engraving needle holding plate 102, a number of engraving needle holding holes are provided at predetermined intervals on the same circumference, and the base end of the engraving needle 1 for seal is fitted into each of the holes. Hold. In the figure, two engraving needles 1 for engraving are held for each engraving needle holding plate 102 for convenience. However, in practice, many engraving needles for engraving are arranged on the same circumference of each engraving needle holding plate 102. 1 can be set up and held.

On the lower side of the disk 101, a large gear 105 fixed to a bottom surface of the vacuum chamber 61 by a plurality of columns 104 is provided.
Are provided concentrically with the disk 101, and a ball bearing 106 is provided between the large gear 105 and the disk 101.
The disk 101 is supported so that it can rotate stably.
Planet gears 107 fixed to the lower ends of the support shafts 103 mesh with the large gears 105.

A motor 110 is provided below the vacuum chamber 61, and a rotating shaft 111 having passed through an internal speed reduction mechanism extends into the vacuum layer 61 through a hermetic bearing 112 provided in the vacuum chamber 61, and a center of the large gear 105 is provided. It penetrates and is fixed to the center of the disk 101. Therefore, when the motor 110 is started, the rotation of the rotating shaft 111 is reduced by the rotation of the disk 101.
Rotates slowly clockwise. Thereby, each support shaft 103 and the engraving needle holding plate 102 also rotate together. Then, since the planetary gear 107 fixed to the lower end of each support shaft 103 is meshed with the fixed large gear 105, each rotates counterclockwise, and rotates the engraving needle holding plate 102 together with the support shaft 103 counterclockwise. To rotate.

For this reason, each engraving needle holding plate 102 is
Revolves counterclockwise while revolving clockwise with 01. A power supply terminal 124 insulated by an insulator 123 is provided on the upper surface of the vacuum chamber 61.
A brush 125 at the tip of 24 is in sliding contact with the upper surface of the metal disk 120. A DC power supply 83 applies a voltage of −600 V between the power supply terminal 124 and the grounded vacuum chamber 61.

The insulators 109, 121, 1 of this jig 100
All parts other than 23 are made of metal.
20, the support shaft 103, and the engraving needle holding plate 102 are made of copper, aluminum, or the like having good conductivity, through which the engraving needles 1 for the seal set on the engraving needle holding plate 102 are energized, and a voltage of −600 V is applied. Is applied.

Therefore, after the inside of the vacuum chamber 61 is evacuated as described with reference to FIG. 17, a gas containing carbon is introduced from the gas inlet 63, and −600 is applied to each of the engraving needles 1 for seal.
By applying a DC voltage of V to generate plasma around the DLC film, a DLC film can be formed on the surface (on which the intermediate layer is formed) of each of the engraving needles 1 for stamping by a plasma CVD process.

At this time, each engraving needle holding plate 102 is
Since it revolves counterclockwise while revolving clockwise together with 1, even if a large number of engraving needles 1 for stamping are set in the vacuum chamber 61 at one time, the DLC film can be formed uniformly and evenly. become. The example in which the jig 100 is installed and used in the vacuum layer shown in FIG. 17 has been described. However, the jig 100 may be used in the same manner when installed in the vacuum layer shown in FIG. 15 or FIG. it can. Further, if the jig 100 is arranged in the vacuum chamber 51 shown in FIG. 14, an intermediate layer can be uniformly formed on a large number of the substrates of the engraving needles 1 for seal at a time.

Next, in order to make the surface of the DLC film 30 formed on the surface of the base material of the engraving needle for seal 1 via the intermediate layer 20 smoother, the surface of the DLC film 30 is subjected to polishing. A step of finish polishing by lapping may be performed so that the surface roughness Ra is 0.2 to 0.02 μm.

In this case, the cloth is polished by applying a diamond paste or an alumina paste, and a disk-shaped plate is wrapped with the diamond paste or the alumina paste. The particle size of diamond or alumina in the diamond paste or alumina paste at that time is about 0.1 μm to 4 μm, and 1 μm for polishing.
As for the above, it is preferable to use one having a thickness of 1 μm or less for lapping. Even if such a polishing process is performed, DLC
Since the film is firmly formed on the surface of the base material of the engraving needle 1 for seal via the intermediate layer, it does not peel off.

As described above, by increasing the smoothness of the surface of the DLC film formed on at least the surface of the cutting blade portion 13 of the engraving needle 1 for seal, the load resistance when engraving the seal material is further reduced, and a Good sharpness can be maintained and a large number of seals can be carved with high precision. In addition, substantially the entire surface of the engraving needle 1 'for stamps or other shapes of the engraving needle for stamps according to the second embodiment of the present invention shown in FIGS. DLC is applied to the surface of the material via an intermediate layer in the same manner as in the above-described steps.
A film can be formed.

[Thickness of Each Coating Formed on Engraving Needle for Seal] Here, various materials concerning the material and thickness of the intermediate layer and the thickness of the DLC film formed on the surface of the engraving needle for seal according to the present invention are described. An example will be described.

(Example 1) Material Film thickness (μm) Substrate of engraving needle: alloy tool steel or cemented carbide Intermediate layer: silicon 0.05 to 0.2 DLC film: DLC 0.4

(Example 2) Material Film thickness (μm) Substrate of engraving needle: alloy tool steel or cemented carbide Intermediate layer: SiC 0.05 to 0.2 DLC film: DLC 0.4

(Example 3) Material Film thickness (μm) Substrate of engraving needle: alloy tool steel or cemented carbide Intermediate layer: Ti / Si 0.05 to 0.2 DLC film: DLC 0.3

(Example 4) Material Film thickness (μm) Base material of engraving needle: Alloy tool steel or cemented carbide Intermediate layer: Ti / SiC / C mainly 0.05-0.2 DLC film: DLC 2

[Test Results of Seal Production] As a test product of the engraving needle for a seal, a superhard HIP-treated product (φ2.0 × 48 mm) manufactured by Mitsubishi Materials was designated as A or B, and the conventional case where it was used as it is as “N” The case according to the present invention in which a Ti film is formed as an intermediate layer, a Ti film is formed as an upper layer, and a Si film is formed as an upper layer, and a DLC film is formed thereon as 0.2 μm and used, is referred to as “DLC”. Table 1 shows the results of attaching each of the engraving needles for seals to an automatic engraving machine "Zengo G" manufactured by Link Co., Ltd., and actually engraving characters on the seal material of buffalo and tussell to produce seals.

[0099]

[Table 1]

According to the results, in the case of the test product A, when the conventional N was used, the seal of the buffalo material was changed to 38.
After engraving the book, it was necessary to replace the needle when 26 carved seals of the material were carved (a total of 64 were carved). When using the DLC according to the present invention, 150 carved seals of the water buffalo material were used. After that, 105 engraved seals made of Tsuge material (total 255 engraved) required replacement of the needle.

Further, in the case of the test product B, when the conventional N was used, after engraving 40 seals made of buffalo material and then engraving 35 seals made of Tsuge material (75 engraved in total). It was necessary to replace the engraving needle, but the DLC
When using, it was necessary to replace the engraving needle when 148 carved seals of buffalo material were carved and then 145 carved seals of Tsuge material (a total of 313 were carved). Therefore,
When using either of test products A and B, the conventional N
It can be seen that the use of the DLC according to the present invention makes it possible to engrave approximately four times the number of seals without replacing the engraving needles as compared with the case of using.

Further, as a test product of an engraving needle for a seal, an ultrafine-grained HIP-treated product (φ2.0, manufactured by Toshiba Tungaloy) was used.
× 48 mm) as C and D, N as the conventional case where it is used as it is, a Ti film as a lower layer and a Si film as an upper layer of 0.1 μm each as an intermediate layer, and a DLC film on top of 0.1 μm.
A case according to the present invention in which a 2 .mu.m film is formed and used is referred to as DLC. Attach the engraving needle for each seal to the automatic engraving machine “Super Horisuke MW-77” manufactured by Nippon Microware Co., Ltd. It is shown in FIG.

[0103]

[Table 2]

According to the result, in the case of the test product C, when the conventional N was used, the seal of the water buffalo material was changed to 78.
When engraving the book, it was necessary to replace the engraving needle. However, when the DLC according to the present invention was used, it was necessary to replace the engraving needle when engraving 360 seals made of buffalo material.

Further, in the case of the test product D, when the conventional N was used, it was necessary to replace the engraving needle when 122 stamps made of the Tsuge material were engraved.
When using, it was necessary to replace the engraving needle when engraving 498 seals made of Tsuge material. Therefore, when using the DLC according to the present invention, no less than four times the number of seals engraved without replacing the engraving needle when using the DLC according to the present invention, regardless of whether the test products C or D are used. It turns out that it is.

[0106]

As described above, according to the present invention, the durability of the engraving needle for a seal is remarkably improved, and the frictional resistance during engraving is greatly reduced. Will not break. Therefore, a seal that is four times or more the size of a conventional seal can be manufactured with a single seal engraving needle, and the engraving accuracy of the engraved seal can be improved, and an elegant and clear character seal can be manufactured.

[Brief description of the drawings]

FIGS. 1A and 1B are a plan view and a front view, respectively, of a first embodiment of the present invention, in which an engraving needle for a seal is seen in an upright state.

2 is an enlarged front view and a side view of a cutting blade portion of the seal engraving needle shown in FIG. 1. FIG.

FIG. 3 is a plan view showing a distal end surface of the cutting blade together with a circumscribed circle.

FIG. 4 is a longitudinal sectional view showing a part of the cutting blade portion further enlarged.

FIG. 5 is a plan view of a second embodiment of the present invention in a state where a seal engraving needle is placed horizontally.

FIG. 6 is a front view of the same.

FIG. 7 is a left side view of the same.

FIG. 8 is a schematic diagram showing a configuration example of a hard coating by greatly enlarging a very small portion near the surface of the cutting blade portion of the seal engraving needle according to the present invention.

FIG. 9 is a schematic diagram showing a configuration example when the number of intermediate layers is two.

FIG. 10 is a schematic diagram showing a configuration example when the intermediate layer is another two layers.

FIG. 11 is a schematic diagram showing a configuration example in the case where there are three intermediate layers.

FIG. 12 is a diagram for explaining a method for testing the wear resistance of a coating film using a wear tester.

FIG. 13 is a diagram showing a relationship between a scratch load and a scratch resistance measured by performing a scratch test on various samples corresponding to a seal stamp engraving needle according to the present invention and a conventional seal stamp engraving needle. .

FIG. 14 is a cross-sectional view of a sputtering apparatus used in an intermediate layer forming step in the method of forming a hard film on a seal for engraving according to the present invention.

FIG. 15 shows a plasma CV used in a DLC film forming step in the method for forming a hard film on a seal engraving needle according to the present invention.
It is sectional drawing which shows an example of D apparatus.

FIG. 16 is a sectional view showing another example of the plasma CVD apparatus.

FIG. 17 is a sectional view showing still another example of the plasma CVD apparatus.

FIG. 18 is a schematic view showing an example of a jig used to form a coating on a large number of engraving needles for seals at once in the plasma CVD apparatus.

[Explanation of symbols]

 1, 1 ': engraving needle for seal 11, 11': body 12: conical portion 13, 15: cutting blade 13a: tip surface 15a: plane parallel to the central axis 10: base material (alloy tool steel or super Hard alloy) 10a: Base surface 20: Intermediate layer 21: Intermediate layer lower layer 22: Intermediate layer intermediate layer 23: Intermediate layer upper layer 30: Diamond-like carbon coating (DLC film) 51, 61: Vacuum layer 55: Target 56: Target holder 69: High frequency power supply 79: Anode 81: Filament 100: Jig 101: Disk 102: Engraving needle holding plate 103: Support shaft 105: Large gear 106: Ball bearing 107: Planetary gear 108: Strut 109: Insulator 110: Motor 111: Rotary shaft of motor 112: Hermetic bearing 120: Metal disk 121: Insulator 122: Ball bearing 12 3: insulator 124: power supply terminal 125: brush

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] May 24, 2001 (2001.5.2)
4)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 13

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0015

[Correction method] Change

[Correction contents]

Alternatively, argon is introduced into the evacuated vacuum chamber and ionized, and a sputtering process using titanium as a target is performed to form at least a portion of the surface of the engraving needle in contact with the seal material to form an intermediate layer mainly composed of titanium. A first intermediate layer forming step of forming a lower layer, and subsequent to this step, a gas containing carbon is introduced into the vacuum chamber, and titanium carbide is formed on the lower layer by a reactive sputtering process targeting titanium or silicon. Or a second intermediate layer forming step of forming an intermediate layer mainly composed of silicon carbide, and subsequently, the sputtering amount of titanium or silicon of the target is gradually reduced, and carbon is mainly formed on the intermediate layer. It was performed and a third intermediate layer forming step of forming an upper layer of the intermediate layer to be, may be formed an intermediate layer of three layers.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0040

[Correction method] Change

[Correction contents]

[Evaluation of Wear Resistance by Wear Test] Here, the engraving needle for a seal according to the present invention and the conventional engraving for a seal are described.
A wear test was performed on a test piece having the same coating configuration as that of the engraved needle, and the results were compared to evaluate wear resistance. The abrasion tester used here is a product name NU of Suga Tester Co., Ltd.
It is a wear tester of S-ISO-2.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0076

[Correction method] Change

[Correction contents]

Next, a second DLC film forming method will be described with reference to FIG. FIG. 16 is a sectional view of a plasma CVD apparatus used for that purpose. When the apparatus shown in FIG. 16 is used, the engraving needle 1 for stamping with the intermediate layer 20 is arranged in a vacuum chamber 61 having a gas inlet 63 and an exhaust port 65. The vacuum degree is 4 × 10 ⁻³ Pascal (3 × 10 3
^The air is evacuated from the exhaust port 65 so that the pressure becomes ⁻⁵ torr) or less.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] Explanation of sign

[Correction method] Change

[Correction contents]

[Description of Signs] 1, 1 ': Engraving needle for seal 11, 11': Main body 12: Conical part 13, 15: Cutting blade part 13a: Tip surface 15a: Plane parallel to central axis 10: Base material ( Alloy tool steel or cemented carbide) 10a: Surface of base material 20: Middle layer 21: Lower layer of middle layer 22: Middle layer of middle layer 23: Upper layer of middle layer 30: Diamond-like carbon coating (DLC film) 51, 61 : Vacuum chamber 55: Target 56: Target holder 69: High frequency power supply 79: Anode 81: Filament 100: Jig 101: Disk 102: Engraving needle holding plate 103: Support shaft 105: Large gear 106: Ball bearing 107: Planetary gear 108 : Support 109: Insulator 110: Motor 111: Motor shaft 112: Hermetic bearing 120: Metal disk 121: Insulator 122: Ball Bearings 123: Insulator 124: power supply terminal 125: Brush

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) C23C 28/00 C23C 28/00 B (72) Inventor Hidefumi Kasai 6-11-12 Honcho, Tanashi-shi, Tokyo Citizen Watch Co., Ltd. Tanashi Factory (72) Inventor Yukio Well 14-29 Doyamacho, Kita-ku, Osaka, Osaka Wako Tsusho Co., Ltd. (72) Hideo Okubo 14-29 Doyamacho, Kita-ku, Osaka, Osaka Company Wako Tsusho F-term (reference) 4K029 AA02 BA02 BA07 BA17 BA34 BA35 BA55 BA56 BA57 BB02 BC02 BD05 CA06 DC03 DC05 GA00 4K030 AA24 BA28 BB12 CA03 CA05 DA01 LA21 4K044 AA02 AB05 AB10 BA02 BA18 BA19 BB03 BB04 CA05 BC06

Claims (15)

[Claims] 1. An ivory, a buffalo horn, and a cutting blade attached to an automatic seal engraving machine and provided at a tip side of a main body.
Box, a seal engraving needle for engraving a seal material such as plastic, wherein at least the base material of the cutting blade portion that contacts and seals the seal material is made of alloy tool steel or cemented carbide,
A stamp-like engraving needle characterized in that a diamond-like carbon coating is formed on the surface of the cutting blade portion via an intermediate layer for increasing the adhesion to the substrate. 2. The shape of the cutting blade portion is substantially triangular pyramid or substantially quadrangular pyramid, and the tip is 2 ° to 8 ° with respect to the center axis.
The engraving needle for a seal according to claim 1, wherein the engraving needle is a flat surface having an inclination in the range of °. 3. The engraving needle for a seal according to claim 1, wherein the cutting blade has a shape in which a part of a cone in a circumferential direction is cut off on a plane parallel to a central axis. 4. The semiconductor device according to claim 1, wherein the intermediate layer has a one-layer structure formed of any one of silicon, tungsten, titanium carbide, silicon carbide, and chromium carbide. An engraving needle for a seal according to any one of the preceding claims. 5. The intermediate layer according to claim 1, wherein the intermediate layer has a two-layer structure including a lower layer mainly composed of chromium or titanium and an upper layer mainly composed of silicon or germanium. An engraving needle for a seal according to any one of the preceding claims. 6. The intermediate layer has a two-layer structure of a lower layer mainly composed of titanium and an upper layer mainly composed of one of tungsten, tungsten carbide, silicon carbide and titanium carbide. The engraving needle for a seal according to any one of claims 1 to 3. 7. The intermediate layer has a three-layer structure of a lower layer mainly composed of titanium, an intermediate layer mainly composed of titanium carbide or silicon carbide, and an upper layer mainly composed of carbon. The engraving needle for a seal according to any one of claims 1 to 3. 8. The diamond-like carbon coating formed on the surface of the cutting blade through the intermediate layer has a surface roughness Ra of 0.2 to 0.02 μm. 8. The engraving needle for a seal according to any one of items 1 to 7. 9. A method for forming a hard coating on an engraving needle for a seal, wherein the base material of the cutting blade for engraving the stamp material at least in contact with the stamp material is the cutting blade. A step of setting the seal engraving needle, which has been formed and washed, in a vacuum chamber and evacuating; introducing argon into the evacuated vacuum chamber to ionize it;
An intermediate layer forming step of forming an intermediate layer on at least the surface of the base material of the cutting blade portion of the engraving needle by a sputtering process targeting any one of silicon, tungsten, titanium carbide, silicon carbide, and chromium carbide. Exhausting argon in the vacuum chamber and introducing a gas containing carbon into the vacuum chamber; generating plasma in the vacuum chamber; and applying diamond-like gas to the surface of the intermediate layer by plasma CVD. A method of forming a hard coating on an engraving needle for a seal having a step of forming a carbon coating. 10. A method for forming a hard coating on an engraving needle for a seal, wherein the base material of the cutting blade for engraving the seal material at least in contact with the seal material is the cutting blade. A step of setting the seal engraving needle, which has been formed and washed, in a vacuum chamber and evacuating; introducing argon into the evacuated vacuum chamber to ionize it;
A first intermediate layer forming step of forming a lower layer of an intermediate layer mainly composed of chromium or titanium on at least the surface of the base material of the cutting blade portion of the engraving needle by a sputtering process using chromium or titanium as a target; Subsequent to the step, a second intermediate layer forming step of forming an upper layer of an intermediate layer mainly composed of silicon or germanium on the lower layer by a sputtering process using silicon or germanium as a target, and argon in the vacuum chamber. Discharging and introducing a gas containing carbon into the vacuum chamber; and generating plasma in the vacuum chamber and forming a diamond-like carbon film on the upper surface of the intermediate layer by plasma CVD. A method for forming a hard coating on an engraving needle for a seal having: 11. A method for forming a hard coating on an engraving needle for a seal, wherein the base material of the cutting blade for engraving at least the seal material in contact with the seal material is the cutting blade. A step of setting the seal engraving needle, which has been formed and washed, in a vacuum chamber and evacuating; introducing argon into the evacuated vacuum chamber to ionize it;
A first intermediate layer forming step of forming a lower layer of an intermediate layer mainly composed of titanium on at least the surface of the base material of the cutting blade portion of the engraving needle by a sputtering process using titanium as a target, A second intermediate layer forming step of forming an upper layer of an intermediate layer mainly composed of tungsten on the lower layer by a sputtering process using tungsten as a target; A step of introducing a gas containing carbon into the vacuum chamber, and a step of generating plasma in the vacuum chamber and forming a diamond-like carbon film on the surface of the upper layer of the intermediate layer by plasma CVD. Method for forming a hard film. 12. A method for forming a hard coating on an engraving needle for a seal, wherein the base material of the cutting blade for engraving the seal material at least in contact with the seal material is the cutting blade. A step of setting the seal engraving needle, which has been formed and washed, in a vacuum chamber and evacuating; introducing argon into the evacuated vacuum chamber to ionize it;
A first intermediate layer forming step of forming a lower layer of an intermediate layer mainly composed of titanium on at least the surface of the base material of the cutting blade portion of the engraving needle by a sputtering process using titanium as a target, A second intermediate step of introducing a gas containing carbon into the vacuum chamber and forming an upper layer of an intermediate layer mainly composed of tungsten carbide or silicon carbide on the lower layer by a reactive sputtering process targeting tungsten or silicon. Forming a layer, discharging argon in the vacuum chamber and introducing a gas containing carbon into the vacuum chamber, generating plasma in the vacuum chamber, and forming an upper layer of the intermediate layer by a plasma CVD process. Forming a diamond-like carbon coating on the surface of the surface. 13. A method for forming a hard coating on an engraving needle for a seal, wherein the base material of the cutting blade for engraving at least the seal material in contact with the seal material is the cutting blade. A step of setting the seal engraving needle, which has been formed and washed, in a vacuum chamber and evacuating; introducing argon into the evacuated vacuum chamber to ionize it;
A first intermediate layer forming step of forming a lower layer of an intermediate layer mainly composed of titanium on at least the surface of the base material of the cutting blade portion of the engraving needle by a sputtering process using titanium as a target, A second intermediate step of introducing a gas containing carbon into the vacuum chamber and forming an intermediate layer of an intermediate layer mainly composed of titanium carbide or silicon carbide on the lower layer by a reactive sputtering process targeting titanium or silicon. A layer forming step; a third intermediate layer forming step of forming a carbon-based upper layer on the intermediate layer by gradually reducing a sputtering amount of titanium or silicon of the target, following the step; Exhaust gas containing argon and carbon in the
A step of introducing a gas containing carbon again into the vacuum chamber; and a step of generating plasma in the vacuum chamber and forming a diamond-like carbon film on the upper surface of the intermediate layer by plasma CVD. A method for forming a hard coating on an engraving needle for a seal. 14. The method for forming a hard coating on a seal for engraving according to claim 9, wherein the diamond-like carbon coating is formed after the step of forming the diamond-like carbon coating. A method for forming a hard coating on a seal engraving needle, comprising a step of finishing and polishing the surface of the like carbon coating by polishing and lapping. 15. The polishing and lapping in the step of finish polishing is performed with a particle diameter of 0.1 to 4 μm.
The method for forming a hard coating on an engraving needle for a seal according to claim 14, wherein the method is performed using a diamond paste or an alumina paste in which diamond particles or alumina particles are dispersed.