JP2003320552A - Mold assembly for molding optical disk - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold assembly for molding an optical disk which prevents the wear of a mold body due to corrosive gas accompanying a molten resin on the occasion of injection molding and has an excellent heat resistance and durability. <P>SOLUTION: The mold assembly has a stationary mold (first mold body) 1 and a movable mold (second mold body) 2 which demarcate a cavity space for molding the optical disk by injection molding and a butting outer peripheral ring 67 on which the movable mold 2 is so fitted as to be slidable in the direction of opening and closing thereof. A coating layer is formed on the outer peripheral surface 46a of the movable mold 2 or the inner peripheral surface 67a of the ring 67. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk molding die for manufacturing an optical disk such as a DVD (digital video disk).

[0002]

2. Description of the Related Art A substrate for an optical disk such as a DVD is generally manufactured by injection molding a resin. An example of a molding die device used for this injection molding is shown in FIG. The molding die apparatus 200 shown in this figure is configured to include a movable die 201 and a fixed die 202 arranged so as to face the movable die 201. The movable die 201 and the fixed die 202 are connected to each other. A space formed by closing the mold is a cavity space C. The surface of the movable die 201 on the side of the cavity space C is a stamper supporting surface 201A for supporting the disk-shaped stamper 203. The surface of the fixed mold 202 on the side of the cavity space C is a contact surface with a molten resin which will be an optical disk, and is a mirror surface 202A. An outer peripheral ring 204 is arranged on the outer periphery of the fixed die 202 having the mirror surface 202A so as to interlock with the movable die 201. The fixed die 202 is fitted to the outer peripheral ring 204, and the inner peripheral surface 204A of the outer peripheral ring and the fixed die 2
The outer peripheral surface 202B of 02 is slidable in the opening / closing direction of the mold. In order to manufacture a substrate for an optical disc such as a DVD, the cavity space C is filled with a molten resin which is a molding material, the movable mold 201 and the fixed mold 202 are cooled, and the molten resin is solidified, and then the fixed mold 202. Also, the movable mold 201 is opened to take out the molded optical disk. Resin is injected into the cavity space C from the sprue 205 formed in the fixed mold 202 at a position corresponding to the center of the cavity space C through a recess (die) 206 formed at the tip of the sprue 205. In addition, the die 206 of the movable die 201
A cut punch 2 that can be moved back and forth at a position opposite to
07 is moved to the fixed mold 201 side to enter into the die 206, thereby forming an opening hole at the center of the optical disk formed in the cavity space C, and at the same time, the resin in the sprue 205 and the cavity space C. It is designed to cut off the resin (optical disk) inside.

[0003]

The mold apparatus 2 having the above structure
In No. 00, the temperature of the resin injected from the sprue 205 is about 350 to 390 ° C., so that a corrosive gas component is often accompanied. Such a corrosive gas component is exhausted at each shot for manufacturing a substrate by an exhaust hole (not shown) provided in the movable mold 201 or the fixed mold 202 so as to communicate with the cavity space C. Has become. Since this sliding surface is a portion for molding the outer peripheral surface of the optical disc substrate, the fixed mold 2 is used for the purpose of preventing the occurrence of burrs on the outer peripheral portion of the optical disc substrate.
02 outer peripheral surface 202B and outer peripheral ring 204 inner peripheral surface 20
It can slide with a high degree of contact with 4B. The molten resin does not flow into this sliding surface, but since the corrosive gas entrained in the molten resin is a gas, it penetrates into the sliding surface after tens of thousands of shots, and It will roughen the surface of the moving surface. The surface roughness and fine scratches on the sliding surface due to the corrosive gas are transferred to the outer peripheral surface of the disk, and there is a problem that the accuracy of the product deteriorates. When tens of thousands of shots are continuously used, a phenomenon in which the angular accuracy of the corner portion of the fixed mold 202 is deteriorated by corrosive gas, so-called die sagging occurs, which causes burr on the outer circumference of the disk. There was also the problem of doing.

The present invention has been made in order to solve the above problems, and produces a high quality optical disk substrate having excellent durability against corrosive gas entrained in molten resin. It is an object of the present invention to provide a mold apparatus for molding an optical disk that can be used.

[0005]

In order to solve the above problems, the present invention is provided with a first mold body and a second mold body that define a cavity space for molding an optical disk by injection molding. A stamper for forming unevenness on one surface of the optical disc is provided on one of the first mold body and the second mold body, and the other resin contact surface of the first mold body or the second mold body is an optical disc. An outer peripheral ring having a mirror surface for smoothing the surface on the opposite side to the outer peripheral surface of the first mold body or the second mold body having this mirror surface slidably fitted in the opening and closing direction of the mold body. An optical disk molding die apparatus comprising: a coating layer on at least one of an inner peripheral surface of the outer peripheral ring and an outer peripheral surface of the first mold body or the second mold body having the mirror surface. Providing a mold device for optical disk molding characterized by being formed To.

In the mold apparatus according to the present invention having the above structure, a coating layer is provided on at least one of the inner peripheral surface of the outer peripheral ring and the outer peripheral surface of the first mold body or the second mold body having a mirror surface. By providing the above, since it is not eroded by the corrosive gas component entrained in the molten resin, the sliding surface between the mold body and the outer peripheral ring is not roughened. Further, since this coating layer is excellent in self-lubricating property and mechanical strength, it is possible to prevent wear due to sliding between the mold body and the outer peripheral ring, and to provide a mold device having a long life.

In the optical disk molding die apparatus of the present invention, a coating layer is formed on both the inner peripheral surface of the outer peripheral ring and the outer peripheral surface of the first mold body or the second mold body having the mirror surface. ,
In addition, the coating layers are made of different materials. By providing a coating layer on the entire sliding surface between the mold and the outer peripheral ring, the corrosion resistance, mechanical strength, and slidability can be further improved. In particular, when the material forming the coating layer on the inner peripheral surface of the outer peripheral ring and the material forming the coating layer on the outer peripheral surface of the mold are made different,
It is preferable because it is possible to prevent the mold body and the outer peripheral ring from sticking to each other without lowering the adhesion on the sliding surface.

Further, in the optical disk molding die device of the present invention, the coating layer is an Al ₂ O ₃ film, a TiN film, a CrN film,
AlN film, Si ₃ N ₄ film, SiC film, TiC film, TiAl
It is characterized by comprising at least one selected from N film, TiCrN film, cBN film, DLC film, and 4 fluororesin-impregnated chromium film. Since all of these coating layers are excellent in corrosion resistance, mechanical strength, wear resistance, hardness, self-lubricating property and slidability, and have high surface smoothness, It is possible to suppress the occurrence of surface roughness and fine scratches on the sliding surface between the outer peripheral ring and the outer peripheral ring, reduce transfer defects of the disk, and further prolong the life of the mold.

In the optical disk molding die device according to the present invention, the film thickness of the coating layer made of any film excluding the tetrafluororesin-impregnated chromium film is 0.2 μm to 5 μm.
The range is preferably However, when using a tetrafluororesin-containing chromium film as the coating layer, the film thickness is 4
The film thickness is preferably in the range of 0 to 80 μm. If the film thickness of the coating layer is less than 0.2 μm, the durability of the film is insufficient because the coating layer is too thin regardless of the material, and wear is likely to occur at the time of releasing the disc, and a corrosive gas is also used. Easier to be eroded by the components. Further, if the film thickness exceeds 5 μm, peeling of the film is likely to occur due to the stress in the film of the coating layer, and the surface condition becomes rough, which is not preferable.
When using the tetrafluororesin-containing chromium film, the thickness of the fluororesin-containing chromium film is 50 to 7 because it is a plated film.
A film thickness in the range of 0 μm is preferable.

Next, in the optical disk molding die apparatus according to the present invention, the back side of the stamper is evacuated to the first mold body or the second mold body having the stamper supporting surface for supporting the stamper. It is preferable that a vacuum chuck mechanism for fixing the stamper is provided. By providing such a vacuum chuck mechanism, the stamper can be more stably held on the stamper supporting surface, and the gas component entrained with the resin as the molding material and the resin powder obtained by solidifying the gas component to some extent Since it can be discharged to the outside, the maintenance cycle can be extended. Therefore, the operating time of the device can be lengthened and the production efficiency can be improved.

Next, in the optical disk molding die apparatus according to the present invention, the mold body having the stamper supporting surface may be formed with a claw portion for fixing the inner end portion of the stamper. it can. By fixing the inner end of the stamper with such a claw portion, the stamper can be more stably fixed, and burrs can be suppressed from occurring at the boundary between the inner end of the stamper and the mold body that holds the stamper. It is possible to manufacture a high quality optical disc.
Further, by fixing with the claw portion, it is possible to prevent the stamper from rising during molding. That is, it is possible to prevent strong contact between the stamper and the stamper supporting surface by filling the resin with the stamper in a floating state. This action also makes it possible to manufacture an optical disc with high smoothness, extend the life of the stamper, and thus extend the life of the mold apparatus.

Next, in the optical disk molding die apparatus according to the present invention, a taper surface is formed on the surfaces of the first mold body and the second mold body which are opposed to each other and which is fitted in a taper when the mold is closed. And a guide pin provided on one of the first mold body and the second mold body and a guide pin of the other mold body, and the guide pin is provided on the mold body. And a guide member having a guide pin receiver slidably fitted in the opening / closing direction.

At the time of molding an optical disk, a pair of mold bodies are closed, and a product cavity formed between these mold bodies is filled with a molding material. After the molding material filled in the product cavity, that is, the optical disk is solidified, both molds are opened and the molded optical disk is taken out. In a state where the two mold bodies are closed, the two molding bodies are centered by the tapered surfaces of the positioning members fixed to the molding bodies being fitted to each other. On the other hand, when the two mold bodies are open, the positioning members of the two mold bodies are separated from each other, but the guide pins and the guide pin receiver into which the guide pins are slidably fitted in the opening and closing directions of the two mold bodies are used to The body is aligned. With such a configuration, since both mold bodies are surely aligned with each other and the resin is filled and molded, the pressure from the resin acting on the stamper can be made uniform,
In combination with the action of the coating layer, it is possible to further extend the life of the mold device.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an optical disk molding method of the present invention and an optical disk molding die apparatus used in this method will be described below with reference to the drawings. First, the structure of a mold device for molding an optical disk will be described. Reference numeral 1 is a fixed die as a first die body, 2 is a movable die as a second die body, and these fixed die 1 and movable die 2 are the die opening / closing directions (shown by AB in FIG. 1) in FIGS. Direction) to open and close each other to form product cavities (cavity spaces) 3 for forming an optical disk when the mold is closed. In addition, in FIGS. 1, 2 and 4, the fixed mold 1 and the movable mold 2 are shown in the vertical direction in the drawing (shown as AB in FIG.
However, normally, the molding is performed in a state in which the fixed mold 1 and the movable mold 2 are horizontally arranged (that is, the mold is opened and closed in the horizontal direction). However, it is also possible to perform the molding in a state where they are lined up and down as shown.

The fixed mold 1 comprises a fixed mold plate 6 and a fixed mounting plate 7 fixed to the surface of the fixed mold plate 6 opposite to the movable mold 2. The fixed side mounting plate 7 is attached to a fixed side platen of an injection molding machine (not shown). 7a shown in FIG.
Is a through hole formed in the fixed side mounting plate 7 for passing a bolt for mounting on the fixed side platen. A sprue bush 8 to which the nozzle of the injection molding machine is connected is fixed by a bolt 9 to the central portion of the fixed-side mounting plate 7. The sprue bush 8 has a sprue 10 which is a material passage inside, but the fixed side mounting plate 7 and the fixed side mold plate 6 are penetrated, and the tip thereof is to the movable mold 2 side of the fixed side mold plate 6. It is protruding. Further, on the surface of the sprue bush 8 opposite to the movable die 2,
An annular locate ring 11 is arranged and a bolt 12
Is fixed to the sprue bush 8.

The fixed-side mold plate 6 is fixed to the fixed-side mounting plate 7 with bolts 16 and has a substantially disk-shaped cavity block 17 as a cavity forming member, and the fixed-side mounting plate 7 is fixed with bolts 18. And a substantially annular fixed side positioning ring 19 as a positioning member. The fixed-side positioning ring 19 includes the step portion 20 and the cavity block 1 formed on the peripheral portion of the surface of the fixed-side mounting plate 7 on the movable die 2 side.
7 is fitted on the outer peripheral side and is aligned with the cavity block 17 at the stage of mold production. And
The fixed side positioning ring 19 has a tapered surface 21 on the inner peripheral surface of the movable mold 2 side portion, the diameter of which increases toward the movable mold 2 side. The angle of the tapered surface 21 with respect to the mold opening / closing direction is about 5 to 30 °.

Further, as shown in FIG. 3, columnar guide pins 22 are fixed to the two corners of the fixed side mounting plate 7 which are located substantially on a diagonal line. As shown in FIG. 2, the guide pin 22 has a flange portion 23 formed on one end side thereof abutted against the fixed side mounting plate 7, and one end side of the flange portion 23 is formed on the fixed side mounting plate 7. Is fitted in the hole 24 and is fixed by the auxiliary member 25 provided on the other surface side of the fixed side mounting plate 7 and the bolt 26 penetrating the auxiliary member 25 and screwed to the end surface of the guide pin 22. ing. And
The guide pin 22 projects toward the movable mold 2 side with the mold opening / closing direction as the axial direction. Further, a flange-shaped stopper 27 is fixed to the tip end surface of the guide pin 22.

Further, a step portion 31 is formed on the outer peripheral portion of the cavity block 17 shown in FIG. 1 on the movable die 2 side, and an annular adjuster ring 32 is fitted in the step portion 31. It is fixed by bolts 33. On the other hand, an inner peripheral stamper retainer 35 as a substantially cylindrical tubular member is fitted and fixed in the through hole 34 as a hole formed in the central portion of the cavity block 17. As shown in FIG. 4, a stamper 36 for forming irregularities on the optical disk is detachably attached to the cavity block 17, and an inner peripheral stamper retainer 35 covers the inner peripheral portion of the stamper 36. It is designed to be fixed. That is, as shown in FIG. 4, a claw portion 37 for pressing the floating of the inner peripheral portion of the stamper 36 is formed on the outer peripheral end of the side surface of the movable die 2 of the inner peripheral stamper retainer 35. The outer circumference of the stamper is fixed by air vacuum. Further, the sprue bush 8 is fitted in a cylindrical inner peripheral stamper retainer 35. A recess 38 communicating with the sprue 10 is formed on the tip surface of the sprue bush 8 on the movable die 2 side. The stamper 36 is made of a metal plate such as Ni. In the case of a DVD stamper, the stamper 36 has an arc shape formed along the disc circumferential direction such as a groove portion and a land portion that define the information recording area of the DVD. The mold for forming the convex portions and the circular arc-shaped groove formed between these convex portions is provided on one surface. In the case of a CD stamper, it has a mold for forming pits for recording information along the disc circumferential direction.

In the mold apparatus of the present embodiment, the provision of the claw portion 37 enables the stamper 36 to be more reliably prevented from floating from the stamper supporting surface 17a and fixed. As a result, it is possible to prevent the stamper 36 from floating from the stamper support surface 17a during molding, and prevent damage to the stamper 36 and the stamper support surface 17a. That is, when the resin is filled while the stamper 36 is floating from the stamper supporting surface 17a, the stamper 36 is pressed by the pressure of the resin filled at a high pressure.
Although these members may be worn by being pressed by a and contacting each other at that time, such contact can be prevented if the stamper 36 is fixed on the stamper supporting surface 17a.

Further, as shown in FIG. 1, the peripheral edge of the surface of the cavity block 17 on the product cavity 3 side is
A groove is formed in a substantially annular shape, and the exhaust passage 4 is connected to the groove. Although only one exhaust passage 4 is shown in FIG. 1, it is provided at about 8 to 12 places along the groove. The exhaust passage 4 is connected to an exhaust means (not shown), and the stamper 36 is fixed by exhausting the inside of the exhaust passage 4 by the exhaust means. That is, the exhaust passage 4 constitutes a vacuum chuck mechanism for adsorbing and fixing the outer peripheral side of the stamper 36.

The movable die 2 includes a movable side mold plate 41, a movable side receiving plate 42 fixed to a surface of the movable side mold plate 41 opposite to the fixed mold 1, and a fixing on the movable side receiving plate 42. A movable side mounting plate 44 fixed by a bolt 43 is provided on the surface opposite to the mold 1. The movable side attachment plate 44 is attached to the movable side platen of the injection molding machine. The movable side mold plate 41 has a substantially disk-shaped core block 46 as a cavity forming member fixed to the movable side receiving plate 42 with a bolt 45, and a positioning member fixed to the movable side receiving plate 42 with a bolt 47. And a substantially annular movable side positioning ring 48. The movable side positioning ring 48 is fitted to the stepped portion 49 formed on the outer peripheral portion of the surface of the movable side receiving plate 42 facing the fixed die 1 and the outer peripheral side of the core block 46, and the die manufacturing is performed. At this stage, the core block 46 is centered. Further, the movable side positioning ring 48 has a tapered surface 50 to which the tapered surface 21 of the fixed side positioning ring 19 abuts when the mold is closed. Furthermore, this tapered surface 50
On the outer peripheral side of the movable side positioning ring 48, a spacer 51 against which the fixed side positioning ring 19 abuts is fixed by a bolt 52 to the surface of the movable side positioning ring 48 facing the fixed side positioning ring 19. That is, the fixed side positioning ring 19 and the movable side positioning ring 48 are fitted with a spigot.

Further, as shown in FIG. 2, the through holes 24 of the fixed side receiving plate 7 at the two corner portions of the movable side receiving plate 42 and the movable side mounting plate 44 which are located substantially on a diagonal line. A through hole 56 is formed at a position facing each other. Then, in the through holes 56 of the movable side receiving plate 42, guide pin receivers 58 into which the guide pins 22 on the fixed mold 1 side are slidably fitted in the mold opening / closing direction are incorporated.

These guide pin receivers 58 are cylindrical guide bushes 59 fitted and fixed in the through holes 56, and slide ball bearings slidably incorporated on the inner peripheral side of the guide bushes 59. Alternatively, it comprises a retainer 60 made of a slide roller bearing or the like, and the guide pin 22 is always fitted to the inner peripheral side of the retainer 60. In addition, this guide pin 22
The stopper 27 prevents the retainer 60 from coming off. The tip of the guide pin 22 is inserted into the through hole 57 formed in the movable side mounting plate 44.

A step portion 66 is formed on the outer peripheral portion of the core block 46 shown in FIG. 1 on the stationary die 1 side. The step portion 66 is provided with an annular abutment outer ring 67. It is fitted so as to be slidable in the mold opening / closing direction. The butting outer peripheral ring 67 is secured to the movable side receiving plate 42 by bolts 68. A slide bearing 69 is interposed between the abutting outer peripheral ring 67 and the outer peripheral surface of the core block 46. Further, the butting outer peripheral ring 67 is biased toward the fixed mold 1 side by the spring 70. Then, the abutting outer peripheral ring 67
Is the adjuster ring 32 on the fixed mold 1 side when the mold is closed.
The outer peripheral surface of the optical disc. A coating layer 71 is formed on the outer peripheral surface 46 a of the core block 46.
Is formed, and the core block 46 has the coating layer 71.
At, the inner peripheral surface 67a of the abutting outer peripheral ring 67 is slidably fitted.

A substantially annular work outlet 77 is fitted in a recess 76 formed on the surface of the core block 46 on the stationary die 1 side, and is inserted from the rear side of the recess 76. It is fixed by bolts 78. An air passage 79 formed in the core block 46 and the movable-side receiving plate 42 communicates with the gap between the processing blow-out insert 77 and the inner peripheral surface of the recess 76.

Further, a substantially cylindrical projecting sleeve 81 is fitted in the work blow-out insert 77 so as to be slidable within a predetermined range in the mold opening / closing direction. The protruding sleeve 81 penetrates the core block 46 and has one end side located inside the movable side receiving plate 42.
A slide bearing 82 is interposed between the two. Further, the protruding sleeve 81 is provided with a spring 83.
Is urged to the side opposite to the fixed mold 1. Note that 84
Is a regulation plate fixed in the movable side receiving plate 42 for regulating the sliding range of the protruding sleeve 81.

A gate cut sleeve 86, which is a substantially cylindrical gate cut member, is fitted in the protruding sleeve 81 so as to be slidable within a predetermined range in the mold opening / closing direction. The gate cut sleeve 86 penetrates the protruding sleeve 81 and the regulation plate 84,
A slide bearing 87 is interposed between the gate cut sleeve 86 and the protruding sleeve 81. A flange portion 88 formed at one end of the gate cut sleeve 86 is located closer to the movable side attachment plate 44 than the regulation plate 84. Further, the gate cut sleep 86 is biased by the spring 89 toward the side opposite to the fixed mold 1.

Further, the movable side mounting plate 44 has
A protruding plate 91 is supported so as to be slidable in a predetermined range in the mold opening / closing direction. The protruding plate 91 is used for the spring 9
It is urged by 2 to the side opposite to the fixed die 1. And
A protrusion pin 93 fixed to the protrusion plate 91 is slidably fitted in the gate cut sleeve 86. Further, the interlocking pin 94 fixed to the protruding plate 91 penetrates the flange portion 88 of the gate cut sleeve 86 and the regulating plate 84 and abuts against the protruding sleeve 81. Further, a receiving portion 95 provided on the flange portion 88 of the gate cut sleeve 86 is slidably passed through the protruding plate 91.

Then, as shown in FIG.
A gate 96 for connecting the sprue 10 on the fixed die 1 side to the product cavity 3 is formed between the outer peripheral portion of the tip surface of the sprue bush 8 on the side and the outer peripheral portion of the gate surface of the gate cut sleeve 86 on the movable die 2 side. It is like this. In addition, the gate cut sleeve 86 is provided in the recess 3 of the sprue bush 8.
By fitting into the gate 8, the resin as the molding material in the sprue 10 and the resin in the product cavity 3, that is, the optical disk are cut at the gate 96, and an opening hole at the center of the optical disk is formed. There is. Therefore, in the fixed mold 1, in addition to the cavity block 17, a part of the optical disk is formed by the inner peripheral stamper retainer 35 and the outer peripheral portion of the tip end surface of the sprue bush 8. In addition, in the movable die 2, in addition to the core block 46, the work blow-out insert 77 and the protruding sleeve 8 are provided.
1 also forms part of the optical disc.

The sliding surface between the abutting outer peripheral ring 67 and the core block 46 will be described in more detail with reference to FIG. FIG. 5 is a view showing a partial cross-sectional structure of the optical disk molding die apparatus of the present invention shown in FIG. 1, which schematically shows the outer peripheral portion of a product cavity for molding an optical disk. The scale of components is different from the actual scale. As described above, the core block 46 is fitted to the inner peripheral surface 67a of the butting outer peripheral ring 67,
Step portion 66 provided on the outer peripheral surface 46a of the core block 46
Is slidable. A coating layer 71 is formed on the outer peripheral surface 46a of the core block 46, so that the inner peripheral surface 67a of the abutting outer peripheral ring and the outer peripheral surface 46a of the core block 46 slide more smoothly, and at the time of disk molding. Protects the sliding surface from the generated gas components.

In the mold apparatus of this embodiment, the coating layer 7 is formed on the outer peripheral surface 46a of the core block 46 which is one of the sliding surfaces.
By providing No. 1, it is possible to prevent the corrosive gas entrained with the molten resin from coming into contact with the outer peripheral surface 46a, making it possible to prevent surface roughness on the outer peripheral surface 46a from occurring easily, and to provide a mold apparatus with a long life. realizable. Further, since it is possible to prevent deterioration of the angular accuracy of the corner portion 46R of the core block 46 due to corrosion of the gas component, that is, so-called mold sagging, it is possible to improve the durability of the mold device as well. Further, since the coating layer 71 has high hardness and high mechanical strength, it is possible to prevent the outer peripheral surface 46a from being scratched or worn, so that the die device can have a long life.

The constituent material of the coating layer 71 is not particularly limited as long as it has high mechanical strength and corrosion resistance, and examples thereof include metals, ceramics, resins and the like. Further, a composite material such as metal and ceramics, metal and resin, resin and ceramics may be used.
Among them, Al ₂ O ₃ film and Ti are used as materials having high hardness and low friction coefficient and having properties such as lubricity and oxidation resistance.
N film, CrN film, AlN film, Si ₃ N ₄ film, SiC film, T
iC film, TiAlN film, TiCrN film, cBN (cubic boron nitride) film, DLC (Diamond Like Carbon) film,
Chromium film impregnated with tetrafluoride resin (Tef Lock etc.)
Can be illustrated.

The film thickness of the coating layer 71 is not particularly limited and can be appropriately changed depending on the material thereof,
It is preferably in the range of 2 to 5 μm. 0.2 μm
If it is less than 1, the film made of any material is too thin and does not have sufficient wear resistance, and wear easily occurs due to sliding between the abutting outer peripheral ring 67 and the core block 46.
It also lacks corrosion resistance and is susceptible to erosion by corrosive gas components. Further, when the film thickness exceeds 5 μm, the stress in the film becomes strong and peeling easily occurs, and the film surface becomes rough and is transferred to the outer peripheral surface of the disk regardless of the material used. It is not preferable. However, since the chrome film containing tetrafluororesin requires Cr plating on the underlayer, a thickness of 30 μm or more is necessary, and in order to satisfy the required properties in terms of corrosion resistance and wear resistance, it is 40 to 80 μm.
The thickness is preferably μm.

Further, even if the coating layer 71 is a single layer, 2
It may be a laminate of one or more kinds. For example, a TiC film having excellent adhesion to a die material is formed and TiN having high hardness is formed.
It is preferable to use a laminated composite film because it has excellent adhesion and mechanical strength. The film thickness ratio between the TiC film and the TiN film is preferably in the range of 3: 1 to 1: 3. That is, with respect to the total thickness of the coating layer 71, Ti
The C film and the TiN film are preferably at least 1/4 or more. This is the outer peripheral surface 46 a of the core block 46.
The TiC film formed on the substrate is superior to the TiN film in strength and adhesion to the outer peripheral surface 46a, but is inferior to the TiN film in terms of corrosion resistance to gas components, and the TiN film is stronger than the TiC film. Is inferior, but because it has excellent corrosion resistance,
Within the above range, it is possible to realize the coating layer 71 having the advantageous characteristics of each of the TiC film and the TiN film. Further, the film thickness ratio between the TiC film and the TiN film is more preferably in the range of 2: 1 to 1: 2.

Further, when laminating two or more layers, a first coating layer made of a metal compound is first provided, and an Al ₂ O ₃ film having excellent corrosion resistance is formed on the first coating layer. A configuration in which the second coating layer is laminated is suitable. As the metal compound, a material having good adhesion to the metal material forming the mold is preferable, and particularly TiN, TiC, TiAlN,
It is preferably one or more selected from cBN and the like. By interposing these metal compound layers, it is possible to obtain a mold apparatus having further excellent corrosion resistance and abrasion resistance.

At this time, the thickness of the Al ₂ O ₃ film is 0.2 to 4 μm.
It is preferably in the range of m. This is because if the film thickness is less than 0.2 μm, the desired wear resistance and oxidation resistance cannot be obtained because it is too thin, and if it exceeds 4 μm, peeling easily occurs due to the stress in the film. The thickness of the first coating layer is preferably in the range of 0.5 to 5 μm. If the film thickness is less than 0.5 μm, the adhesion strength is not sufficient and it is 5 μm.
This is because when it exceeds m, the surface roughness becomes large.

Further, as represented by a tetrafluororesin-impregnated chromium film (Tef Rock, etc.), it may be a composite film in which a metal film is impregnated with a tetrafluororesin having excellent lubricity. It is preferable to use such a film because it is excellent in self-lubricating property and surface smoothness in addition to corrosion resistance and wear resistance. In particular, the composite plating material in which chrome plating is impregnated with tetrafluoride resin has the characteristics of chrome plating such as high hardness, low friction coefficient and wear resistance, and the characteristics of tetrafluoride resin such as self-lubrication and low friction characteristics. Since it also has non-adhesiveness, it is preferable.

TiA is used as a constituent material of the coating layer 71.
When the 1N film is used, the composition ratio of Ti and Al is Ti _a A
When represented by _lb N (a + b = 1), a is 0.1 or more and 0.1.
It is preferably 9 or less and b is in the range of 0.1 or more and 0.9 or less, more preferably a is 0.2 or more and 0.8 or less, and b is 0.2 or more and 0.8 or less. It is within. If the value of a is too large, sufficient corrosion resistance and oxidation resistance cannot be obtained, and if it is too small, the wear resistance rapidly deteriorates. On the contrary, if the value of b is too large, the wear resistance rapidly deteriorates, and if it is too small, sufficient corrosion resistance and oxidation resistance cannot be obtained. Further TiAl
The composition of the N film may change in the thickness direction within the film, or two or more TiAlN films having different compositions may be laminated.

Such a coating layer 71 is formed by PVD method, CV method.
D method, sputtering method, ion plating method, PVD-
By using a thin film forming method such as an ion plating method, a coating layer having a desired composition and a desired film thickness can be formed.

In the optical disk molding die apparatus of the present invention shown in FIG. 5, the outer peripheral surface 4 of the core block 46 is
Although the coating layer 71 is formed only on 6a, the mold apparatus of the present invention is not limited to this. The coating layer 71 may be formed even on the resin contact surface of the core block 46 on the product cavity 3 side. In addition, the outer peripheral surface 46 of the core block 46
The coating layer 71 may be provided on the inner peripheral surface 67a side of the abutting outer peripheral ring 67 instead of a.

Further, as shown in FIG. 6, coating layers 71a and 71b may be provided on both the outer peripheral surface 46a of the core block 46 and the inner peripheral surface 67a of the abutting outer peripheral ring 67, respectively. In this case, it is preferable that the material forming the coating layer 71a and the material forming the coating layer 71b be different. This is because when the coating layers 71a and 71b are made of the same material, the coating layers stick to each other, and conversely the slidability deteriorates. When the coating layers 71a and 71b are provided on both the core block 46 and the abutting outer peripheral ring 67 in this manner, both the outer peripheral surface 46a and the inner peripheral surface 67a, which are sliding surfaces, are protected by the coating layer. As a result, it is possible to obtain a mold device that is more excellent in corrosion resistance and mechanical strength.

Next, a method of molding an optical disk using the mold apparatus having the above-mentioned structure will be described. Note that FIG. 1, FIG.
4, FIG. 5, and FIG. 6, the fixed mold 1 and the movable mold 2 are drawn side by side in the drawing, but normally, the molding is performed in a state where the fixed mold 1 and the movable mold 2 are horizontally arranged. However, it is also possible to perform the molding in a state where they are lined up and down as shown. Both the guide pins 22 of the fixed die 1 shown in FIGS. 2 and 3 are always fitted to the guide pin receivers 58 of the movable die 2 regardless of whether the fixed die 1 and the movable die 2 are opened or closed. Is. As a result, the fixed die 1 and the movable die 2 are aligned with each other. That is, the central axis of the cavity block 17 of the fixed mold 1 and the central axis of the core block 46 of the movable mold 2 are located on the same straight line.

At the time of molding an optical disk, first, the fixed mold 1 and the movable mold 2 are closed, and the fixed mold 1 and the movable mold 2 are closed.
A product cavity 3 is formed in between. It should be noted that, with the mold closed in this way, the abutment ring 67 of the movable mold 2 abuts on the adjuster ring 32 of the fixed mold 1, and the positioning rings 19, 48 of the fixed mold 1 and the movable mold 2 are fitted to each other by the spigot fitting. And their tapered surfaces 21, 50 taper to each other. Then, a molten thermoplastic resin as a molding material is injected from the nozzle of the injection molding machine into the sprue 10. This resin is sprue 10 to gate 96
To flow into the product cavity 3 through the (filling step).
Initially, the mold clamping force of the fixed mold 1 and the movable mold 2 is relatively weak, and the pressure of the resin filled in the product cavity 3 causes the fixed mold 1 and the movable mold 2 to slightly move, for example, from 0.1 to 1. Opening about 0.3mm, positioning ring 19, 48
The abutting ring 67 slidably supported by the core block 46 of the movable mold 2 is held by the adjuster ring 32 by the biasing force of the spring 70, although the taper surfaces 21 and 50 are slightly separated.

After the product cavity 3 has been filled with the resin in this way, the receiving portion 95 of the gate cut sleeve 86 is pushed toward the fixed mold 1 by a pressing rod (not shown) provided on the injection molding machine side. As a result, the gate cut sleeve 86 moves to the fixed mold 1 side and fits into the recess 38 of the sprue bush 8 of the fixed mold 1. As a result, the sprue 10 and the product cavity 3 are blocked at the gate 96, and an opening hole at the center of the optical disc is formed (gate cutting step). Further, as the die clamping of the fixed die 1 and the movable die 2 is strengthened, almost the entire movable die 2 including the core block 46 moves to the fixed die 1 side. As a result, the resin in the product cavity 3 is compressed (compression step). At the end of this compression step, the tapered surfaces 21, 50 of the positioning rings 19, 48 of the fixed mold 1 and the movable mold 2 are again taper-fitted to each other. This ensures that the stationary die 1 and the movable die 2 are aligned with each other after the end of the compression process.

Further, after the resin in the product cavity 3, that is, the optical disk is cooled and solidified, the fixed mold 1 and the movable mold 2 are opened. With this mold opening, the molded optical disk and the resin solidified in the sprue 10 first separate from the fixed mold 1. Then, the ejecting plate 91 is pushed toward the fixed mold 1 by a pressing rod (not shown) provided on the injection molding machine side, and the ejecting pin 93 moves to the fixed mold 1 side in conjunction with the ejecting plate 91. , The resin solidified in the sprue 10 is ejected and released from the movable mold 2. In addition, the interlocking pin 9 fixed to the protruding plate 91
By being pushed by 4, the ejection sleeve 81 moves to the fixed die 1 side, and the inner peripheral portion of the optical disc is ejected and released from the movable die 2. At the time of this mold release, the air supplied from the air passage 79 is blown out from the gap between the air blowing insert 77 and the core block 46, so that the vacuum break between the optical disk and the movable mold 2 is performed. Then, the released optical disc is taken out by a take-out robot (not shown). At that time, the take-out robot moves the guide pin 2 between the fixed die 1 and the movable die 2.
2 and the corners where the guide pin receivers 58 are not provided come in and go out. It is to be noted that what is molded in this way is not the final product, which is the optical disc, but the substrate thereof, after which a protective layer, recording layer, reflective layer, overcoat layer, etc. are appropriately formed. To be done.

According to the configuration of the present embodiment, the guide pin 22 provided on the fixed die 1 is fitted into the guide pin receiver 58 provided on the movable die 2 so as to be slidable in the die opening / closing direction. Since the movable die 2 and the movable die 2 are aligned with each other, even when the fixed die 1 and the movable die 2 are opened and the tapered surfaces 21 and 50 of the positioning rings 19 and 48 are separated from each other, the movable die and the movable die 2 are movable. Can be aligned with the mold 2. That is, in the filling process, gate cutting process and compression process after the fixed mold 1 and the movable mold 2 are closed once, the fixed mold 1 and the movable mold 2 are slightly opened. It is possible to hold the fixed die 1 and the movable die 2 in a state of being aligned with each other to some degree of accuracy against the gravity applied to the die 2. Therefore, when the gate cut sleeve 86 on the movable die 2 side is fitted into the recess 38 of the fixed die 1 in the gate cutting step,
The gate cut sleeve 86 is securely and accurately fitted in the recess 38. Therefore, the opening hole of the optical disk can be accurately formed at a predetermined position, and the occurrence of defects such as burrs in the opening hole can be prevented.

After the end of the compression process, the fixed mold 1
And the movable mold 2 are finally completely closed to form the product cavity 3
In the final product shape, the tapered surfaces 2 of the positioning rings 19 and 48 of the fixed mold 1 and the movable mold 2 are
The fixed die 1 and the movable die 2 are aligned with each other by taper-fitting the first die 1 and the second die 50. At that time, since the positioning rings 19 and 48 are not movably supported by the fixed mold 1 and the movable mold 2, respectively, but are fixed, centering by the positioning rings 19 and 48 is performed by a guide. Pin 22 and guide pin receiver 58
It is more reliable and accurate than centering by using only. As described above, since the cores can be surely aligned when the molds are closed, the product cavity 3 can be accurately defined, and the pressure of the resin introduced from the sprue 10 is more uniform in the product cavity 3. Can be

Further, in the present embodiment, the guide pin 2
2 and the guide pin receiver 58 are provided only in two sets,
The final centering of the fixed mold 1 and the movable mold 2 is performed by the positioning rings 19 and 48, and the guide pin 22 and the guide pin receiver 58 are auxiliary, so that the fixed mold 1 is fixed.
And it is sufficient to have two corners of the movable mold 2. When the fixed mold 1 and the movable mold 2 are opened to take out the molded optical disk, a take-out robot is operated between the fixed mold 1 and the movable mold 2 via the corners without the guide pins 22 and the guide pin receivers 58. By taking in and out, the guide pin 22 and the guide pin receiver 58 do not interfere with the taking out of the optical disc.

The present invention is not limited to the above embodiment, but various modifications can be made. For example, in the above-described embodiment, the fixed mold 1 is provided with the guide pin 22 so as to project, and the guide pin 22 into which the guide bin 22 is slidably fitted is provided in the movable mold 2. The guide pin may be provided on the fixed type and the guide pin receiver may be provided on the fixed type. Further, in the above-described embodiment, the guide pin 22 and the guide pin receiver 58 are two sets, but one set or three sets.
It may be more than one set.

Further, according to the optical disk molding die apparatus of the present invention, the height is 0.04 mm or more (preferably 0.04 mm) higher than the surface of the information recording section on the inner peripheral side of the information recording section.
It is also possible to manufacture an optical disk having a protruding annular convex portion (05 mm or more). An example of an optical disc having such a configuration is shown in FIG. FIG. 7 is a diagram showing a partial cross-sectional structure of the optical disc. Optical disc 1 shown in FIG.
Reference numeral 01 has a disk shape, has an opening 102 in the central portion, and has a portion other than the inner peripheral portion and the outer peripheral portion serving as an information recording portion 103. Also, the optical disc 10
On one surface of the optical disc 101, there is an annular convex portion 104 located on the inner peripheral side of the information recording portion 103 and having a height h of 0.04 mm or more protruding from the surface of the information recording portion 103. It is formed concentrically with the whole. This convex part 1
The height h of 04 is more preferably 0.05 mm or more. In the optical disc 101 having such a configuration, even if the burr 105 is generated on the surface of the optical disc 101 during molding, for example, when the optical disc 101 is mounted on the turntable 106 of the optical disc drive device, the convex portion 104 is not formed on the burr 105. It has a structure to be mounted on the turntable 106. Therefore, the optical disc 101 can be mounted on the turntable 106 without being tilted without being affected by the burr 105, and surface wobbling during rotation of the optical disc can be prevented. Alternatively, the hub can be mounted parallel to the optical disc when the hub is later attached to the optical disc.

Next, the optical disc 101 having the above-mentioned convex portion
The configuration of the mold apparatus for manufacturing the above will be described below with reference to FIG. FIG. 8 is a diagram showing a partial cross-sectional view of an optical disk molding die apparatus according to the present invention, showing a central portion of a product cavity for molding an optical disk. The basic structure of the mold device shown in FIG. 8 is almost the same as that of the mold device shown in FIG. 1, and the same components as those in FIG. 1 are designated by the same reference numerals. The characteristic point of the mold device shown in FIG. 8 is that the depth of 0.04 mm or more (preferably 0.05 mm) is formed on the surface of the air blowing insert 77 on the product cavity 3 side.
The above is the point that the annular recess 99 is engraved. By performing molding using the mold device having such a configuration, as shown in FIG. 7, it is possible to manufacture the optical disc 101 having the convex portion 104 formed by transferring the shape of the concave portion 99.

[0052]

Example 1 A stainless disk (180 mmφ × 20 mm thick) whose surface is mirror-polished so as to form a cavity surface which is a surface facing a stamper is prepared, and the outer circumference of this stainless disk is prepared. DLC (diamond-like carbon) was vapor-deposited on the surface by an arc discharge plasma method while varying the film thickness. In the vacuum container having the DLC ion source, the above-mentioned disk is arranged so as to face the ion source to form a substrate, the pressure is reduced to a vacuum, and then argon gas is introduced.
The pressure was adjusted to 10 ^-5 Torr. After applying a bias voltage of 1000 V to the substrate to clean the surface by sputtering, the filament of the DLC ion source is heated to apply a high frequency to the anode electrode to generate plasma. After that, benzene gas was introduced to decompose in the ion source to generate carbon ions, and DCL was vapor-deposited on the side surface of the disk. At that time, by applying a bias voltage of 50 V to the substrate, an LC film was deposited on the substrate surface at a deposition rate of 0.5 μm / hr.

Example 2 A stainless steel disc (180 mmφ × 20 mm thick) similar to that of Example 1 was prepared, and the thickness of the stainless steel disc was varied by the plasma jet CVD method. A cBN film was deposited. As a substrate by placing the stainless steel disk in the reaction vessel,
A DC plasma torch is installed above it, and after evacuation Ar, N
A mixed gas of ₂ , BF ₃ , and H ₂ was caused to flow from a torch, decomposed in plasma, and vapor-deposited on a substrate. The pressure during film formation was 50 Torr (50 × 133 Pa), and the substrate was water-cooled and maintained at 1000 ° C. Further, the substrate was rotated during the film formation so that the entire surface of the film formation was uniformly coated with the cBN film. As a result of analyzing the formed thin film by X-ray diffraction, it was confirmed to be a cBN film.

(Example 3) A stainless steel disk (180 mmφ x 20 mm thick) similar to that in Example 1 was prepared, and a cBN film was deposited on the outer peripheral surface of this stainless disk by magnetron sputtering. A pedestal for magnetron sputtering is placed in a vacuum container, a target of hexagonal BN is fixed to this pedestal, and the stainless disk is placed on the opposite surface to form a substrate. After depressurizing to vacuum, Ar is introduced. 2 x
As 10 ⁻⁴ Torr (266 × 10 ⁻⁴ Pa), 13.
Sputtering was performed by applying a high frequency of 56 Mz to the target. At that time, a high frequency (bias voltage) was also applied to the substrate side. A film having a thickness of 1 μm was obtained by forming the film for 1 hour. As a result of analyzing the formed thin film by X-ray diffraction, it was an amorphous cBN film.

Example 4 Stainless Steel Same as Example 1
Prepare a circular plate (180 mmφ x 20 mm thickness)
Al on the outer peripheral surface of the disk by magnetron sputtering₂O₃
Films were deposited with varying thicknesses. Specifically, true
In the empty container, the magnet Al sputter base is made of metal Al.
Of the stainless steel circle on the opposite surface by fixing the target
Arrange the plates into a substrate, reduce the pressure to vacuum, and then add Ar and O.₂
Ar partial pressure of the mixed gas of 2.7 × 10 ^-3Torr (35.
9 x 10^-2Pa) and introduce DC, and DC
Voltage is applied to the target to generate plasma and target.
Was sputtered. This Al₂O₃X-ray diffraction of the film
When analyzed, the crystalline form was γAl₂O₃And
It was

(Example 5) Stainless steel similar to Example 1
Prepare a circular plate (180 mmφ x 20 mm thickness)
Al on the outer peripheral surface of the disk by magnetron sputtering₂O₃
The film was evaporated. Specifically, the machine placed in the vacuum container is
Al on the pedestal for the magnetron sputter₂O₃The target of
Fix and place the stainless steel disc on the opposite surface.
After decompressing to a vacuum as a substrate, Ar is introduced and the pressure is
2 x 10^-FourTorr (266 × 10 ^-FourPa)
And apply a high frequency of 13.56 Mz to the target.
Was sputtered. On the substrate by reaction for 3 hours
1 μm Al₂O₃A film was obtained. This Al from X-ray diffraction₂O₃
When the film was analyzed, its crystalline form was amorphous.
Met.

(Embodiment 6) A stainless steel disc (180 mmφ × 20 mm thickness) similar to that of the embodiment 1 is prepared, and T is formed on the outer peripheral surface of the disc by an arc ion plating method.
The iN film was deposited by changing the film thickness variously. A target of titanium metal was fixed in a vacuum container, the above-mentioned stainless steel disc was placed as a substrate, the pressure was reduced to a vacuum, and then nitrogen gas was introduced to adjust the pressure to 10 ^-4 Torr. 10 on board
After applying a bias voltage of 00V to sputter and clean the surface, apply 15V to the target with a voltage of 20V.
The arc discharge of A was generated, and Ti was evaporated from the target surface. At that time, a TiN film was deposited on the surface of the substrate by applying a bias voltage of 50 V to the substrate. A TiN film was obtained at a vapor deposition rate of 1 μm / hr. T by X-ray diffraction
It was confirmed to be iN.

Example 7 A stainless steel disc (180 mmφ × 20 mm thick) similar to that of Example 1 was prepared, and a TiN film was vapor-deposited on the outer peripheral surface of the disc by plasma CVD. The stainless steel disk is placed in a reaction vessel heated to 500 ° C. to make a substrate, which is then evacuated to a vacuum, and then argon gas is set to 10 ⁻² Torr.
A high frequency of 45 MHz was added for cleaning. Then, a mixed gas of hydrogen and argon was added to adjust the pressure to 1 Torr. Adding TiCl ₄ and a mixed gas of hydrogen and nitrogen (volume ratio 1: 50: 5) to 1 Torr while adjusting the substrate to 300
A high frequency of W was applied to generate plasma to deposit TiN. Vapor deposition rate is 0.5μ / hr and 1μm after vapor deposition for 2 hours.
No TiN film was obtained. It was confirmed to be TiN by X-ray diffraction.

(Embodiment 8) A stainless steel disc (180 mmφ × 20 mm thick) similar to that of the first embodiment is prepared, and the outer peripheral surface of this disc is subjected to Ti by an arc ion plating method.
The C film was deposited by changing the film thickness variously. A Ti target was fixed in a vacuum container, and the stainless disk was placed on the opposite surface to form a substrate. Then, after reducing the pressure to vacuum, acetylene gas was introduced to adjust the pressure to 10 ⁻⁵ Torr.
It was adjusted to (133 × 10 ⁻⁵ Pa). And 1 on the board
After applying a bias voltage of 000V to sputter and clean the surface, apply 1V to the target with a voltage of 20V.
A 5A arc discharge is generated, and Ti is emitted from the target surface.
Was evaporated. At that time, a TiC film was deposited on the surface of the substrate by applying a bias voltage of 50 V to the substrate. The vapor deposition rate of this TiC film was 1 μm / hr.

(Embodiment 9) A stainless steel disc (180 mmφ × 20 mm thickness) similar to that of the embodiment 1 is prepared, and a tetrafluoride resin-impregnated chromium film is formed on the outer peripheral surface of the disc in various thicknesses. Formed. Chromium film impregnated with tetrafluoride resin
After plating the surface of the material with chrome plating with a film thickness of 50 to 70 μm, perform a porous treatment of chrome plating.
It can be obtained by heating to 0 ° C. to expand the cracks of porous chrome, impregnating with a tetrafluororesin, cooling to −70 ° C., and sealing the porous chrome.

(Embodiment 10) A stainless steel disc (180 mmφ × 20 mm thickness) similar to that of the embodiment 1 is prepared, and the outer peripheral surface of the disc is changed to various thicknesses by the arc ion plating method and the TiAlN is changed. The film was evaporated. Specifically, a Ti / Al alloy (Ti50%.
Al 50%:% is% by mass, the same shall apply hereinafter) is fixed, and the stainless disk is placed on the opposite surface to form a substrate. After depressurizing to a vacuum, nitrogen gas is introduced to
The pressure was adjusted to × 10 ^-4 Torr (13.3 × 10 ^-3 Pa). After applying a bias voltage of 1000V to the substrate to sputter and clean the surface, apply 20V to the target.
Arc discharge of 15 A was generated at a voltage of 1 to evaporate TiAl from the target surface. At that time, by applying a bias voltage of 50 V to the substrate, the deposition rate is 1 μm / h.
A TiAlN film was deposited on the substrate surface by r. From the lattice constant by X-ray diffraction, the composition of TiAlN was a composition of Ti _0.5 Al _0.5 N, which was close to the composition of the target.

(Embodiment 11) The composition of the target is (Ti
70% Al30%)
Then, the TiAlN film is vapor-deposited by changing the film thickness variously.
It was The composition of the film is Ti_{0. 7}Al_0.3It was N.

Example 12 Two targets (Ti5)
0% Al 50% and Ti 70% Al 30%) In a vacuum container placed 90 degrees apart, a stainless steel disc similar to that in Example 10 was placed, and TiAl was placed in the same manner as in Example 10.
An N film was deposited. At that time, first, Ti 70%, Al 30%
Place the substrate in the direction of the target for 1 hour and Ti70
% ・ Al30% target is arc-discharged, then the direction of the substrate is changed and placed in the direction of Ti50% ・ Al50% target for 1 hour, Ti50% ・ Al50%
The target was arc-discharged. The obtained film is Ti
_0.7 Al _0.3 N 1 μm, Ti _0.5 Al _0.5 N 1 μm 2
It became a layer coating film. Further, a two-layer coating film was formed on the outer peripheral surface of the stainless steel disc in the same manner except that the film thickness was variously changed.

Example 13 Two targets (Ti5)
0% .Al50% and Ti70% .Al30%) A stainless steel disk similar to that used in Example 10 was placed in a vacuum container placed 90 degrees apart, and a TiAlN film was deposited in the same manner as in Example 10. At that time, the two targets were simultaneously arc-discharged, and the substrate was initially arranged in the direction of the targets of Ti 70% and Al 30%, and then, with the passage of time, Ti
The substrate was gradually rotated in the direction of the target of 50% / Al50% so that the direction of the target of Ti50% / Al50% was finally obtained. After vapor deposition for 2 hours, the composition on the substrate side is Ti _0.7 Al _0.3 N and the composition on the surface side is Ti
It was possible to obtain a TiAlN film having a thickness of 2 μm in which the ratio of Ti and Al was continuously changed in the thickness direction with _0.5 Al _0.5 N. Further, a TiAlN film in which the ratio of Ti and Al was continuously changed in the thickness direction was formed on the mold resin contact surface in the same manner except that the film thickness was variously changed.

Example 14 A stainless steel disc (180 mmφ × 20 mm thick) similar to that in Example 1 was prepared, and a TiC film was vapor-deposited to 1 μm on the outer peripheral surface of this disc under the same conditions as in Example 8. Thereafter, a TiN film having a thickness of 2 μm was vapor-deposited on the TiC film under the same conditions as in Example 6. Microscopic observation of the cross section of the deposited film thus obtained confirmed that a coating film composed of a laminated film of a TiC film / TiN film was obtained on the substrate.

(Example 15) The coating order was changed under exactly the same conditions as in Example 14, and a 2 µm TiC film was laminated on a 1 µm TiN film on the outer peripheral surface of a stainless steel disk.

Example 16 A stainless steel disc (180 mmφ × 20 mm thick) similar to that of Example 1 was prepared, and a TiN film was vapor-deposited on the outer peripheral surface of this disc under the same conditions as in Example 6. The Al ₂ O ₃ film was deposited under the same conditions as in Example 4. From the micrograph of the cross section of the film formed on the side surface of the stainless steel disk, the TiN film is 2 μm on the outer surface of the disk.
Al ₂ O ₃ formed on the TiN film and made of γAl ₂ O _3.
It was confirmed that the O ₃ film was laminated in a thickness of 1 μm.

Example 17 A stainless steel disc (180 mmφ × 20 mm thick) similar to that of Example 1 was prepared, and TiA was formed on the outer peripheral surface of this disc under the same conditions as in Example 10.
After depositing the 1N film, Al under the same conditions as in Example 4.
_{A 2} O ₃ film was deposited. Analysis of the deposited film thus obtained revealed that a Ti _0.5 Al _0.5 N film of 2 μm was formed.
It was confirmed that an Al ₂ O ₃ film made of γAl ₂ O ₃ was laminated on this TiAlN film by 1 μm.

Example 18 A stainless steel disc (180 mmφ × 20 mm thick) similar to that of Example 1 was prepared, and a cBN film was vapor-deposited on the outer peripheral surface of this disc under the same conditions as in Example 2. The Al ₂ O ₃ film was deposited under the same conditions as in Example 4. Analysis of the obtained vapor deposition film revealed that cBN
A film is formed with a thickness of 1 μm, and γAl is formed on this cBN film.
The Al ₂ O ₃ film consisting ₂ O ₃ was confirmed to have been 1μm stacked.

Example 19 A stainless steel disc (180 mmφ × 20 mm thick) similar to that in Example 1 was prepared, and TiC was formed on the outer peripheral surface of this disc under the same conditions as in Example 14.
After depositing a two-layer film of —TiN, an Al ₂ O ₃ film was deposited under the same conditions as in Example 4. When the cross-section of the vapor-deposited film thus obtained was observed in the same manner as above, TiC was 1 μm.
It was confirmed to be a three-layer film of m-TiN 1 μm-γAl ₂ O ₃ 1 μm.

Example 20 A stainless steel annular body having an inner diameter of 120 mm and an outer diameter of 165 mm was prepared. Except that this torus was used as the substrate instead of the stainless disk used as the substrate in Examples 1 to 19 above, the film thickness was varied on the inner peripheral surface of this torus. And the same coating layers as in Examples 1 to 19 were formed.

(Embodiment 21) Each of the stainless steel discs prepared in the above Embodiments 1 to 19 is placed on the surface facing the stamper so that its mirror surface faces the product cavity, and its coating layer is abutted. By fitting it so as to be slidable in the outer peripheral ring, it was mounted on a mold device and injection-molded. Tables 1 and 2 show the results of visual observation of the state of the sliding surface between the stainless steel disc and the torus after 300,000 shots.

(Embodiment 22) Each annular body prepared in Embodiment 20 is used as an abutting outer ring of a core block and mounted on a mold device so that its coating layer slides on the core block and is injected. Molded. Tables 3 and 4 show the results of visual observation of the state of the sliding surface between the core block and the torus after 300,000 shots.

(Example 23) A stainless disk having a coating layer formed thereon in Examples 1 to 19 was prepared.
These were arranged on the surface facing the stamper so that the mirror surface thereof faces the product cavity. In addition, these were fitted to the inner circumference of the annular body on which the coating layer was formed in Example 20, respectively, and mounted on the mold device so that the coating layers could slide with respect to each other, and injection molding was performed. went. Table 5 shows the results of visual observation of the state of the sliding surface between the disc and the torus after 400,000 shots.

[0075]

[Table 1]

[0076]

[Table 2]

[0077]

[Table 3]

[0078]

[Table 4]

[0079]

[Table 5]

As shown in Tables 1 and 2, the mold having the coating layer formed on the outer peripheral surface of the core block or the inner peripheral surface of the outer peripheral ring satisfies the requirements of the present invention. It was confirmed that the sliding surface with the outer peripheral ring had no scratches or discoloration, and that it had extremely good durability. Further, as shown in Tables 3 and 4, a mold satisfying the requirements of the present invention in which a coating layer is formed on both the outer peripheral surface of the core block and the inner peripheral surface of the outer peripheral ring is a core that can be used even after 400,000 shots. It was confirmed that the sliding surface between the block and the outer peripheral ring was not scratched or discolored, and had extremely good durability. Further, as shown in Table 5, when the coating layer on the outer peripheral surface of the core block and the coating layer on the inner peripheral surface of the outer peripheral ring are made of the same material, a slight discoloration is observed on the sliding surface. It was

[0081]

As described above in detail, in the optical disk molding die device of the present invention, since the coating layer is provided on at least one of the outer peripheral surface of the mold body and the inner peripheral surface of the outer peripheral ring, the melting is achieved. Since it is possible to prevent corrosion of the sliding surface between the mold and the outer peripheral ring due to the gas components that are entrained in the resin and introduced into the product cavity, it is possible to reduce mold sagging and minute scratches due to corrosion. Thus, it is possible to provide a mold apparatus capable of manufacturing a high-quality optical disc free from scratches and burrs. Further, since it is possible to prevent the mold surface from being roughened due to corrosion, it is possible to extend the life of the mold device. Further, since the coating layer has high hardness, wear resistance, and self-lubricating property, sliding between the mold body and the outer peripheral surface can be made smoother, and thereby a mold having excellent durability can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional configuration diagram of an optical disk molding die device according to the present invention.

FIG. 2 is a cross-sectional view of a guide pin and a guide pin receiver provided in the optical disk molding die apparatus according to the present invention.

FIG. 3 is a plan view of a fixed mold of the mold device shown in FIG.

FIG. 4 is an enlarged cross-sectional view near the gate of the mold device shown in FIG.

5 is an enlarged cross-sectional view of an outer peripheral portion of a product cavity of the mold device shown in FIG.

6 is an enlarged cross-sectional view showing another embodiment of the outer peripheral portion of the product cavity of the mold apparatus shown in FIG.

FIG. 7 is a partial cross-sectional view showing an example of an optical disc manufactured by the mold device according to the present invention.

8 is a sectional configuration diagram showing a configuration of a mold device for manufacturing the optical disc shown in FIG.

FIG. 9 is a partial cross-sectional view showing an example of an optical disk molding die.

[Explanation of symbols]

1 ... Fixed type (first type body) 2 movable type (second type body) 3 product cavity 17a Stamper support surface 19 Fixed side positioning ring 21 Tapered surface 22 Guide pin (guide member) 36 stamper 38 recess 46 core blocks 46a outer peripheral surface 48 Movable side positioning ring (positioning member) 50 taper surface 58 Guide pin receiver (guide member) 66 steps 67 Abutment outer ring 67a inner peripheral surface 71 coating layer 71a coating layer 71b coating layer 86 Gate cut sleeve (gate cut member)

Claims (8)

[Claims] 1. A first mold body and a second mold body that define a cavity space for molding an optical disk by injection molding are provided, and one of the first mold body and the second mold body is provided. A stamper for forming irregularities is provided on one side surface of the optical disk, and the resin contact surface of the other of the first mold body and the second mold body is a mirror surface that smoothes the opposite surface of the optical disk. An optical disk molding die apparatus comprising an outer peripheral ring in which an outer peripheral surface of the first mold body or the second mold body is slidably fitted in an opening / closing direction of the mold body, A mold device for optical disk molding, wherein a coating layer is formed on at least one of the inner peripheral surface of the outer peripheral ring and the outer peripheral surface of the first mold body or the second mold body having the mirror surface. 2. A coating layer is formed on both the inner peripheral surface of the outer peripheral ring and the outer peripheral surface of the first mold body or the second mold body having the mirror surface, and the coating layers are made of different materials. The mold device for optical disk molding according to claim 1, wherein the mold device comprises: 3. The coating layer is an Al ₂ O ₃ film, a TiN film,
CrN film, AlN film, Si ₃ N ₄ film, SiC film, TiC
Film, TiAlN film, TiCrN film, cBN film, DLC
The mold device for optical disk molding according to claim 1 or 2, comprising at least one selected from a film and a fluorinated resin-impregnated chromium film. 4. The film thickness of the coating layer formed of any film excluding the tetrafluororesin-impregnated chromium film is 0.2 μm to 5 μm.
The mold apparatus for optical disk molding according to claim 3, wherein the range is m. 5. The optical disk molding die apparatus according to claim 3, wherein the coating layer made of the tetrafluororesin-containing chromium film has a thickness in the range of 40 to 80 μm. 6. The first mold body or the second mold body having a stamper supporting surface for supporting the stamper is provided with a vacuum chuck mechanism for exhausting the back side of the stamper to fix the stamper. The mold device for optical disk molding according to any one of claims 1 to 5. 7. A mold body having the stamper supporting surface,
7. The optical disk molding die apparatus according to claim 1, further comprising a claw portion for fixing an inner end portion of the stamper. 8. A positioning member provided on opposing surfaces of the first mold body and the second mold body, and having a tapered surface for taper fitting when the mold is closed, and the first mold body and the first mold body. Two
Guide pin provided on one of the mold bodies and a guide pin on the other mold body, the guide pin being slidably fitted in the opening / closing direction of the mold body. A mold member for optical disk molding according to any one of claims 1 to 7, further comprising: a guide member provided with.