JPH0473225B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a disc-shaped information recording carrier used in optical recording or reproducing systems and a method for manufacturing the same.

Conventional configuration and its problems In the optical recording and reproducing system, the optical recording layer of a rotationally driven disc-shaped information recording carrier (hereinafter referred to as a disk) is irradiated with a laser beam corresponding to an information signal. A method that records and reproduces information by providing optical shading or unevenness on the optical recording layer. It is capable of recording minute signals of several micrometers, and in principle allows for high-density recording on the order of the wavelength of light. It is. In addition, since the pickup of the laser beam and the disk do not come into contact with each other during recording and playback, there is no wear and tear, and multi-functions such as still images and high-speed search can be obtained.
It is also being put into practical use for commercial use.

Currently, as an example of forming light guide grooves on the surface of a resin base material, a method as shown in FIGS. 1 to 4 is used. In FIG. 1, minute irregularities are formed on the surface of a resin base material 1 in a certain range of the innermost and outermost peripheries using something such as a nylon scrubber 2 (hereinafter referred to as surface roughening). After that, dirt is removed by ultrasonic cleaning with a solvent and spinner cleaning with pure water, and the process moves on to the replication process in which the light guide grooves are transferred. At this time, since the photocurable resin 3 is used as the groove transfer resin, a solvent binder 4 is applied in advance with a spinner as shown in FIG. 2 in order to increase the adhesive strength between the resin base material 1 and the photocurable resin 3. do.

FIG. 3 shows the replication process, in which a photocurable resin 3 is applied to a metal stamper 5 that serves as a matrix for transferring the light guide groove, and then a resin base material 1 coated with a binder 4 is applied. They are stacked as shown in the figure, and the optical axis forming resin 3 is cured by irradiating ultraviolet light B while applying pressure A to the pressure plates 6a and 6b. Thereafter, as shown in FIG.
and the photocurable resin 3 are simultaneously peeled off to transfer the grooves. The surface roughening 2 and the application of the binder 4 in these steps increase the degree of bonding between the resin base material 1 and the photocurable resin 3, and are very effective when using the photocurable resin 3 and a metal stamper 5 with strong adhesive properties. It has the following. However, if these steps are included, the number of man-hours will inevitably increase, which is rather not desirable for mass production. Furthermore, the surface roughening process also generates dirt, and even though a cleaning process is included, there is a possibility that it may cause image dropouts when the disc is made into a finished disc.

OBJECTS OF THE INVENTION The present invention provides an information recording carrier that eliminates the above-mentioned drawbacks, has good dropout quality, and reduces the number of man-hours, and a method for manufacturing the same.

Composition of the Invention The present invention generates a uniform, minute unevenness forming area on the outer surface of a resin base material by using a chemical,
This strengthens the adhesion between the resin base material and the additional layer for groove transfer, making it possible to perform the conventional surface roughening, cleaning, and binder application all at once.
By doing this, the drop-up quality is improved because a step that causes dirt is eliminated, and at the same time, a significant reduction in the number of man-hours can be expected, so that a cheaper information recording carrier can be manufactured.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 5 shows a resin base material 1 made of acrylic resin immersed in a container 8 filled with toluene 7. When the immersion time increases to a certain extent, minute unevenness formation areas begin to occur on the surface of the resin base material 1.
Finally, a deteriorated layer 9 is completed in which a uniform unevenness region is formed on the entire outer surface. According to experiments, when the immersion time is about 96 hours or more, a uniform deteriorated layer 9 is formed, and the size of the micro-asperity forming area is smaller than about 1 μm.

If replication is performed using the resin base material 1 with such an altered layer 9, adhesive strength comparable to or higher than that of conventional surface roughening and binder coating can be obtained. The additional layer 3 can be easily separated from the metal stamper 5.

In addition, since the micro-asperity forming region comes into contact with the additional layer 3 made of a photocurable resin, if the photo-curing resin has an equivalent refractive index to the resin base material, it will penetrate into the micro-asperity forming region and form an apparent irregularity. The area is the same as if it had disappeared, and optically it does not affect the focus and path of the laser beam.

In the example of the present invention, since the method involves immersing the resin base material 1 in toluene, the altered layers 9 are generated on both sides of the resin base material 1. Therefore, the deteriorated layer 9 remains on the surface of the resin base opposite to the surface on which the grooves are transferred, but this can be avoided especially if the information recording carrier is structured as shown in FIG. No problem. In FIG. 6, an additional layer 3 made of a photocurable resin having optical guide grooves transferred thereto is provided on a resin base material 1 having a deteriorated layer 9, and an optical recording film 10 is deposited on the surface of the additional layer 3. A protective plate 11 made of an acrylic resin similar to the resin base material 1 is bonded to the entire surface of the disk substrate having such a structure using a photocurable adhesive 12. Furthermore, the outer surface of this disk is covered with a hard coat layer 13 made of a photocurable resin having a refractive index equivalent to that of the resin base material 1, and the altered layer 9 remaining on the outer surface of the disk also has an optical effect. will not be given.

Furthermore, according to this dipping method, even if there is dirt on the surface of the resin base material, it can be cleaned at the same time, making it possible to complete the steps of surface roughening, cleaning, and binder application all at once using chemical treatment. It is.

Next, a second embodiment of the present invention will be described.
FIG. 7 shows a resin base material 1 made of acrylic resin, which is heated A while applying mechanical force from the outside, and toluene B is sprayed thereon. By repeating such an operation several times, minute unevenness formation areas are generated on the surface of the resin base material 1, and the adhesive strength during replication can be increased.

This is to promote the formation of uneven regions using a chemical such as toluene while the resin base material 1 is under stress. There are two types of stress generation methods: mechanical and thermal, and it is possible to generate minute irregularities whether each is performed individually or simultaneously.

In addition, in this example, the altered layer is formed by spraying toluene under stress, but it is also possible to form the altered layer in a short time using cloth or paper impregnated with toluene. A similar effect can be obtained by wiping the surface of the resin base material. At this time,
It is important that solvents such as toluene do not remain leaked onto the resin base material for long periods of time; this removes the heat of vaporization when the solvent evaporates, causing distortion in the resin base material surface layer due to minute stress differences. This is because it uses the ability to cause Therefore, applying stress in advance is to promote this phenomenon.
It plays a role in promoting the formation of an altered layer.
Note that when using a solvent such as xylene, when the resin base material is used in combination with polycarbonate, it is possible to form an altered layer even if no stress is applied in advance.

Here, the method of wiping with a cloth or paper impregnated with toluene or xylene and the method of spraying also have the effect of cleaning the resin base material surface at the same time.
There is no need to wash the resin base material again. In addition, when the same treatment is applied to both sides of the resin base material, the surface that will become the outer surface of the disk after assembly can be optically improved by providing a hard coat layer 13 as in the case of the first embodiment. I can do things without problems. However, the main purpose of forming this altered layer is to increase the adhesive strength between the resin base material 1 and the additional layer 3 made of photocurable resin, and treatment for the opposite side is not necessarily necessary. do not.

In addition, when using the optical recording film in the present invention, the material must be one whose light absorption coefficient or both the light absorption coefficient and the refractive index change upon irradiation with laser light; one example is a low tellurium oxide.
Some have a thin film mainly composed of TeO _x (x≈1.0). These thin films include:
Amorphous thin films such as Ge ₁₅ Te ₈₁ Sb ₂ S ₂ and AS ₂ S ₃ are used. When such an optical recording layer is provided, 2
When bonding two resin substrates together over their entire surfaces, it is necessary to use an adhesive that does not deteriorate the optical recording film; for example, in the case of a photocurable adhesive, a polyvinyl alcohol adhesive is preferable.

Further, in the embodiments of the present invention, even if a simple reflective film is provided in place of the optical recording film, there is no problem with the generation of micro-asperity formation areas.

In addition to acrylic resin (PMMA) and polycarbonate, the resin base materials used in the above embodiments include polystyrene, vinyl chloride, polyester, acetate, etc., and are particularly effective when using materials made of organic polymers.

In addition to toluene and xylene, organic solvents that can be used in this example include methyl ethyl ketone, phenol, carbon tetrachloride, acetone, methyl alcohol, and methyl salicylate. may differ from each other.

Effects of the Invention As described above, according to the present invention, micro-roughness formation regions are generated on the surface of the resin base material in a simple manner, and the adhesive strength between the resin base material and the additional layer forming the groove for light guide is increased. This has a great effect in reducing the number of man-hours significantly and at the same time obtaining an inexpensive information recording carrier with high dropout quality.

[Brief explanation of the drawing]

Figure 1 is a perspective view of an information recording carrier in a conventional example in which surface roughening is applied to a resin base material, Figure 2 is a cross-sectional view of an information recording carrier in a conventional example in which a binder is applied to a resin base material, and Figure 3 is a replication example. 4 is a sectional view of an information recording carrier and a pressure plate in a conventional example showing a method for peeling a replica from a metal stamper; FIG. FIG. 6 is a cross-sectional view of an apparatus showing a method for manufacturing an information recording carrier in one embodiment of the invention, FIG. 7 is a sectional view of the same information recording carrier, and FIG. FIG. DESCRIPTION OF SYMBOLS 1... Resin base material, 3... Additional layer made of photocurable resin, 9... Altered layer, 10... Optical recording film, 11
...Protection plate, 12...Light curing adhesive, 13...
Hard code layer, 7... Toluene, 8... Container.

Claims (1)

[Scope of Claims] 1. A modified layer consisting of minute irregularities is formed on the entire surface of at least one side of a resin base material, and an additional layer having light guiding grooves is provided on this modified layer, and this additional layer An information recording carrier with an optical recording film on it. 2. The information recording carrier according to claim 1, wherein the additional layer uses a photocurable resin having a refractive index equivalent to that of the resin base material. 3. A resin base material is immersed in a solvent such as toluene to form an altered layer consisting of minute irregularities on the surface, and an additional layer with light guide grooves formed on this altered layer,
A method for manufacturing an information recording carrier in which an optical recording film is formed on the additional layer. 4 Spray a solvent such as toluene while applying stress to the resin base material to form a modified layer consisting of minute irregularities, form an additional layer with light guide grooves formed on top of this modified layer, and A method for manufacturing an information recording carrier in which an optical recording film is formed on the carrier.