JPS63204529A - Information recording medium and its production - Google Patents

Abstract

PURPOSE:To permit satisfactory joining by providing joints between substrates and spacers on both sides of spacers and welding annular projections of diameters different from each other to the substrates. CONSTITUTION:The disk substrate 51 is installed on a receiving jig 58, on which the inner spacer 53 and outer spacer 55 are placed. An ultrasonic welding horn 57 is then lowered to melt the annular projections 54b, 56b which are provided on the inside and outside spacers on the side in contact with the substrates, by which the ultrasonic welding is executed. The upper disk substrate is then put on the lower substrate with the spacer formed with the welded part of the inner spacer and the welded part of the outer spacer on the lower side. These substrates are subjected to the ultrasonic welding operation. Two sheets of the substrates 51a, 51b of the resultant information recording medium are welded and joined to each other with the respective recording layers 52a, 52b positioned on the inside. The good durability to the exfoliation of the substrates and the spacers by a change in environmental conditions, etc., is thereby obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to an information recording medium and a method for manufacturing the same. Furthermore, the present invention relates to an improvement in a method for manufacturing an information recording medium having an air sandwich structure.

[Technical background of the invention] In recent years, information recording media that use high energy density beams such as laser beams have been developed and put into practical use. This information recording medium is called an optical disc, and includes video discs, audio discs, and even human discs! 1
1 - Used as image files and disk memory for large-capacity computers.

The basic structure of an optical disk is a disk-shaped transparent plate made of plastic, glass, etc., and a recording layer provided thereon. The surface of the substrate on which the recording layer is provided is coated with an overcoat made of a polymeric material, from the viewpoint of improving the flatness of the substrate, improving the adhesive strength with the recording layer, and improving the sensitivity of the optical disc. Layers or intermediate layers may be provided.

Various types of disks are known, and in recent years, air sandwich structures in which the substrate is joined with the recording layer on the inside through inner and outer spacers have become common. .

Conventionally, a set 1' of optical discs with an air sandwich structure
′, the inner spacer and the outer spacer are attached to the disk substrate using an adhesive, especially an ultraviolet ray-curable adhesive, /′
It was common to do this by However, when joining each member using adhesive, it takes several seconds to several minutes to apply the adhesive and assimilate the adhesive per disk, and the productivity is poor. As a means to solve this problem, we used a spacer with protrusions on both sides to create a super
A joining method has been considered in which the protrusions are melted using the f-wave fusion method and fused to the J4 plate (for example,
JP-A-61-80535). However, when the protrusions of the spacer are melted, the protrusions on the far side from one side of the disk substrate are difficult to melt, resulting in a problem of insufficient bonding strength between the protrusions on the far side and the substrate.

In order to solve the problem described in 1-1,
As shown in FIG. 1, Japanese Patent No. 535 discloses a technique in which an ultrasonic vibrating horn is applied from a sea lion to sufficiently melt the protrusions at the same time and bond them to the substrate. That is, the Mif wave fusion splicer 10 emits super?
The °f waves are passed through a converter 17 to an ultrasonic welding horn 15.
16 for fusion bonding. When performing the fusing operation, first the substrate 11 on which the recording layer 12 is to be attached is placed on the ultrasonic fusing horn 16 on the side, and then the inner spacer 1 having protrusions on both sides of the substrate is placed on the substrate 11.
3 and an outer spacer 14 are placed and then another substrate 19 is placed on top. Then, the - side ultrasonic welding horn 15 is placed on top of it, and M? ′! F-waves are sent to the spacer to effect fusion. However, M & wave fusing machines with this type of structure are not common, and must be specially manufactured.Technically, it is necessary to match the vibration phase of ultra-Z'' waves and accurately adjust the balance of vibration intensity. However, there was a problem in that the configuration was complicated.

Also, in JP-A No. 61-80535, the spacer and the lower substrate are first joined by melting the protrusions provided on the spacer, and then the − side substrate is bonded by melting the remaining protrusions of the spacer. 114+ to join! It has also been proposed to divide it into

In this case, the protrusions provided on both sides of the spacer are in symmetrical positions, and even if you wave kiir' from one side, the protrusions on the other side will also melt slightly, so first Jl (When joining the board, the protrusion of the spacer provided on the side not to be joined to the board is accommodated by the relief groove of the projection or the support provided on the side that is not joined to the board, and the protrusion on the side to be joined to the board is However, providing relief grooves for the protrusions in the holder not only complicates the structure of the ultrasonic welding machine, but also makes it difficult to manufacture the culm. It's complicated and not practical.

[Issue 11 [1] Unpublished) Jl aims to provide an information recording medium in which a plate and an inner and outer spacer are well bonded, and a method for manufacturing the same.
1 target.

[Summary of the Invention] The present invention provides two disc-shaped substrates each having a recording layer on at least one of the substrates, which are joined together via a ring-shaped inner spacer and a ring-shaped outer spacer so that the recording layer is on the inside. This is an information recording medium with an air sandwich structure, in which the substrate and the spacer are bonded to each other by fusing ring-shaped protrusions with different diameters to the substrate, which are provided on both sides of each spacer. It consists of a characteristic information recording medium.

Further, in the information recording medium of the air sandwich structure of the present invention, a ring-shaped inner spacer and a ring-shaped outer spacer each provided with ring-shaped projections having different diameters on both sides are brought into contact with the surface of one substrate. A step of ultrasonically welding the protrusions of the spacers and the substrate by a 1" wave, and bringing the other one of the substrates into contact with the unfused 11 protrusions of each spacer, and ultrasonically welding the protrusions of each spacer and the substrate. It can be manufactured by a manufacturing method characterized by including a step of causing.

Detailed description of c-release I11 C-release II will be explained in detail with reference to the attached drawings.

Typical types of spacers used in manufacturing the information recording medium of the present invention are shown in FIGS. 2, 3, and 4.

FIG. 2 shows a cross-sectional view of the inner spacer 20. On both sides of the inner spacer 20, a ring-shaped projection 21a and a ring-shaped projection 21b each having a triangular cross section are provided with different diameters. On the inner and outer circumferential sides of the ring-shaped protrusion 21a and the ring-shaped protrusion 21b, resin inflow portions 22 are provided which are lower than the nof plate contact surface 23, which is the surface of the spacer. The molten resin is allowed to flow in using the fusion method.

FIG. 3 shows a cross-sectional view of the outer spacer 30. A protrusion 31a having a triangular cross section and a ring-shaped protrusion 31b having different diameters are provided on both sides of the outer spacer 30. At the inner and outer bases of the ring-shaped projections 31a and 31b, resin inflow portions 32 are provided that are lower than the substrate contact surface 33, which is the surface of the spacer, and have an angle of more than 1°? The resin melted by the wave melting 11 method is made to flow in.

FIG. 4 is a partially cutaway perspective view of the spacer.

On both sides of the spacer 40, a ring-shaped projection 41a and a ring-shaped projection 41b each having a triangular cross-sectional shape are provided with different diameters. The inner and outer bases of the link-shaped projection 41a and the ring-shaped projection 41b are provided with spacer surfaces J, 11. A resin inflow section 42 is provided which is lower than the temporary contact surface 43, and is designed to allow resin melted by ultrasonic fusion to flow therein. Also, spacer 4
In order to prevent gas flow between the inner circumferential surface and the outer circumferential portion of the air sand structure, the grooves 44 This groove can also be replaced with a through hole.

Next, FIG. 5 and FIG. 6 show step 1 of manufacturing the information recording medium of the present invention.

In FIG. 5, the receiver first places the disk substrate 51 on the jig 58.
(if there is a recording layer 52, it should be facing toward), and the inner spacer 53 and the outer spacer 55 are placed thereon. Next, the ultrasonic welding horn 57 is lowered to melt the ring-shaped protrusion 54b and the link-shaped protrusion 56b provided on the inner and outer spacers on the side that contacts the 1L plate. ° Carry out wave fusion. In this device, the tip of the ultra-t' wave welding horn 57 is configured so as not to come into contact with the ring-shaped protrusion 54a and the ring-shaped protrusion 56a on the 1- side of the inner and outer spacers.

By the operation shown in FIG.
1- of the lower substrate with a spacer on which the disk J and I- plate (if there is a recording layer 52, place it 1-)
(toward the side) and perform an ultrasonic welding operation similar to that shown in FIG. Note that the ultra-fr wave welding horn 61 used at this time is different from the one shown in FIG. 5, and is configured to cover the ring-shaped protrusions 54a and 56a on the upper sides of the inner and outer spacers. Then, the unmelted ring-shaped protrusions 54a and 56a are melted, and the ultrasonic welding between the inner and outer spacers and the substrate is completed.

In addition, in the fusion process shown in Fig. 6, the height of the spacer protrusion (dimension A) becomes zero when the ultrasonic fusion is completed, and the volume of the gap 62 in the disk decreases, so there is no gas between the gap 62 and the outside air. If a flow port is not provided, the pressure within the gap 62 will rise, deforming the disk J^ plate, and causing problems in recording ITt raw performance and the like. In order to prevent this, at least one of the inner and outer spacers has a fourth
Preferably, a groove 44 as shown in the figure is provided.

FIG. 7 shows a cross-sectional view of an air sandwich J%IJ information recording medium (optical disc) completed through the steps shown in FIGS. 5 and 6.

That is, the obtained information recording medium has two substrates 51a.
, 51b are fusion-bonded via an inner spacer 53 and an outer spacer 54 with their respective recording layers 52a and 52b facing inside. This fusion bonding between the substrate and the spacer is achieved centering on the portion where the protrusion of each spacer was provided.

Note that the above description describes preferred embodiments and preferred manufacturing methods of the information recording medium of the present invention, and the present invention is not limited to the above-described embodiments and manufacturing methods. For example, the shape of the protrusion need not be square in cross section, and any shape of the protrusion used in the known ultrasonic melting 11 technique may be used. Further, the number of protrusions provided on the spacer surface does not need to be one on each surface. Alternatively, the spacer surface on the side where the protrusion with a larger diameter is provided can be fused first.

As the substrate, recording layer, and spacer constituting the information recording medium of the present invention, any known substrate, recording layer, and spacer can be used except for the parts that are characteristic of the present invention, and these will be briefly described below.

The substrate used in the present invention can be arbitrarily selected from various materials conventionally used as substrates for information recording media. In terms of the optical properties of the substrate, surface properties, processability, handling, stability over time, and manufacturing costs, examples of substrate materials include acrylic resins such as cell cast polymethyl methacrylate and injection molded polymethyl methacrylate: Preferred examples include vinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymers; epoxy resins; and synthetic resins such as polycarbonate.

Among these, polymethyl methacrylate, polymethyl methacrylate,
Polycarbonate and epoxy resin.

The surface of the substrate on which the recording layer is provided is coated with several pieces of F to improve adhesion and prevent deterioration of the recording layer.
A coating layer (and/or intermediate layer) may be provided.

As for the material of the layer (and/or intermediate layer),
For example, organic substances such as polymeric substances such as polymethyl methacrylate, acrylic acid/methacrylic acid copolymers, nitrocellulose, polyethylene, polypropylene, and polycarbonate; and inorganic oxides (Si02, Al120, etc.), Inorganic fluoride (MgF
Examples include inorganic substances such as 2).

Examples of materials used for the recording layer include Te, Zn, I
n, Sn, Zr, Al2, Ti, Cu, Ge, Au,
Examples include metals such as Pt; i-metals such as Bi, As, and Sb; r-conductors such as Si; and combinations of these alloys or stiff materials.

In addition, these metals, ゛h gold metal or semiconductor sulfide,
Compounds such as oxides, borides, silicon compounds, carbides and oxides; and mixtures of these compounds with metals can also be used in the recording layer. Alternatively, combinations of dyes, dyes and polymers, and dyes and the aforementioned metals and metalloids can also be used.

The recording layer may further contain various known metals, such as gold metal or compounds thereof, as recording layer materials.

The recording layer can be formed on the substrate directly or via an undercoat layer using the above-mentioned materials by vapor deposition, sputtering, ion blasting, coating 41, or other methods. The recording layer may be a single layer or a multilayer, but the layer JrJ is generally 100 to 5500 in terms of optical density required for optical information recording.
It is in the range of λ, preferably in the range of 150 to 1000.

Note that the surface of the substrate opposite to the side on which the recording layer is provided is coated with inorganic substances such as silicon dioxide, tin oxide, and magnesium fluoride to improve scratch resistance and moisture resistance.
A thin film made of a polymeric substance such as a thermoplastic resin or a photocurable resin may be provided by a method such as vacuum deposition, sputtering, or coating.

As the spacer, one made of thermo+4 plastic resin is used.

There is no particular limitation on the material as long as it can be well fused to the substrate by the ultrasonic fusion method. For the purposes of the present invention, 7.
It is particularly preferred to use a material similar to the H-plate material.

[Effects of the Invention] The information recording medium of the present invention has t7-
The ring-shaped protrusions are provided with different diameters, and the plates are ultrasonically welded one by one to the spacer, so the ring-shaped protrusions are sufficiently melted to form a good bond between the substrate and the inner and outer spacers. Form a junction.

Therefore, good durability against peeling between the plate and the spacer due to changes in environmental conditions can be obtained.

Furthermore, the method for manufacturing an information recording medium of the present invention can produce an information recording medium with good bonding as described above, compared to conventional methods. “It can be manufactured using f-wave fusion machine and ultrasonic fusion technology.Therefore, there is no need to use complicated ultrasonic fusion machine, and specially fabricated ultrasonic fusion machine. There is no need. Furthermore, the manufacturing process is simplified and the HF productivity is good.

[Brief explanation of the drawing]

Figure 1 shows how the ultrasonic horns are placed facing each other from above and below.
1 is a cross-sectional view showing a known ultrasonic welding method using an Mrf wave welder. FIG. 2 is a cross-sectional view of an inner spacer with a ring-shaped protrusion. FIG. 3 is a cross-sectional view of an outer spacer with a ring-shaped protrusion. FIG. 4 is a partial perspective view of the spacer. 5 and 6 are cross-sectional views showing an example of the manufacturing process of the information recording medium of the present invention. FIG. 7 is a sectional view showing an example of the structure of the information recording medium of the present invention. 10.50.65: M rf wave melt Rat17.59
: Converter 18.60: Ultrasonic oscillator 15.16.57.61: Ultrasonic horn 13,! 4,2
0.3o, 4o spacer 11.51: substrate 12.52: recording layer 21a, 21b, 31a, 31b, 41a. 41b, 54a, 54b, 56a, 56b, link-shaped projections 22.32.42: PA fat inflow section 44: groove section 23.33.43: J, t, plate contact surface 62: gap 63.64: fused section 51a , 5 l b: J, P plates 52a, 52b: Recording layer 53: Inner spacer 54: Outer spacer Patent applicant: Tomito Photo Film Co., Ltd. Representative Yasushi Yanagawa Figure 2 Figure 3 Figure 4 Figure 5 Edge Figure 6 Figure 7

Claims (1)

[Claims] 1. Two disc-shaped substrates each having a recording layer on at least one of the substrates are joined together via a ring-shaped inner spacer and a ring-shaped outer spacer so that the recording layer is on the inside. An information recording medium having an air sandwich structure, characterized in that the substrate and the spacer are bonded to each other by welding ring-shaped protrusions that are provided on both sides of each spacer and have different diameters to the substrate. Information recording medium. 2. A patent characterized in that at least one of the ring-shaped inner spacer and the ring-shaped outer spacer is provided with a groove or a through hole that allows gas to flow between the inner circumferential surface and the outer circumferential surface of the spacer. An information recording medium according to claim 1. 3. Information on an air sandwich structure in which two disc-shaped substrates each having a recording layer on at least one substrate are joined via a ring-shaped inner spacer and a ring-shaped outer spacer so that the recording layer is on the inside. A method for manufacturing a recording medium, the method comprising: contacting a ring-shaped inner spacer and a ring-shaped outer spacer each having ring-shaped projections with different diameters on both sides with the surface of one substrate; the projections of each spacer and the substrate; and a step of bringing the other one of the substrates into contact with the unfused protrusions of each spacer and ultrasonically welding the protrusions of each spacer and the substrate. A method for manufacturing an information recording medium. 4. The method for manufacturing an information recording medium according to claim 3, characterized in that a spacer is used in which the inner and/or outer bases of the protrusions are lower than the surface of the spacer. 5. The method of manufacturing an information recording medium according to claim 3, wherein the protrusion of the spacer has a triangular cross-sectional shape. 6. A patent characterized in that at least one of the ring-shaped inner spacer and the ring-shaped outer spacer is provided with a groove or a through hole that allows gas to flow between the inner circumferential surface and the outer circumferential surface of the spacer. A method for manufacturing an information recording medium according to claim 3.