JPS6236756A - Grooved optical disk substrate and its production - Google Patents

Abstract

PURPOSE:To obtain a grooved optical disk substrate which satisfies groove transferability, substrate adhesiveness, stamper release property, thermal and physical characteristics of a film, etc. by providing the 1st layer having high adhesiveness on the substrate and providing the 2nd layer having a good stamper release property on said layer. CONSTITUTION:A layer of an epoxy photopolymer (1st layer) 23 is coated by a spinner on the polymethyl methacrylate (PMMA) substrate 21. A layer of a polyol acrylate photopolymer (2nd layer) 22 is formed on the PMMA substrate by using a 2P (photopolymer) automatic transfer device having a nickel stamper (groove stamper mold). The nickel stamper is superposed on the PMMA substrate having the laminated 2P film and is irradiated with an ultra-high pressure mercury lamp from the substrate 21 side. The substrate 21 is stripped from the stamper and the 2P transferred substrate (grooved optical disk substrate) is obtd. Not only epoxy, polyol acrylate and photopolymerizable siloxane but also many polymers including epoxy acrylate, polyester acrylate and urethane acrylate are used for the photopolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of industrial application] The present invention relates to a grooved original disk substrate using a photopolymer and a method for manufacturing the same.

[Conventional technology]

Write and read information on the original disk! In order to do this accurately and easily, spiral or concentric grooves are formed on the substrate, and the light beam is controlled along these grooves.

Conventionally, as a method for forming the above-mentioned grooves on a substrate, 1
For example, there are injection molding method and 2F (photopolymer) forming method.

The former method is highly important because it is suitable for mass production, but it has the disadvantage that it is not possible to produce 1M substrates using glass or metal, and even when using plastics, the substrate material and molding conditions are limited.

On the other hand, in the latter method, liquid photopolymer is poured between the substrate and the stamper, irradiated with ultraviolet rays, and then the photopolymer is removed. Let it harden and stamper 1fltll! Make a stamper! This is a method of separating #I and producing a groove patching source disk substrate. This method has many advantages such as being adaptable to various substrates.

[Problem that the invention seeks to solve]

However, in the latter method, as shown in FIG. Otoborima Ifa 2 had the drawback of peeling off. On the other hand, if a photopolymer that has good adhesion to the substrate is used, it will be difficult to peel off from the substrate, but the stamper releasability will also be poor, making it impossible to obtain a good transfer substrate.

Therefore, in order to eliminate such defects, a primer layer 13' is applied on the substrate 11 as shown in FIG. A method has been considered in which a photopolymer layer 12Y is formed on top of the photopolymer layer 12Y.However, since the primer layer 3 is generally rubber-like, thermal expansion is large and the single disk substrate is exposed to thermal shock environments. There were drawbacks such as peeling of the photopolymer N112 and generation of cracks when the photopolymer was exposed to Yfl'-.

The present invention has been made in view of the above circumstances.

The purpose is to provide a groove-stitched optical disk substrate that satisfies substrate density and stamper removability at the same time, and also has good groove transferability and recording/reproducing characteristics of 7ft*, and a method for manufacturing the same.

[Means for solving problems]

The uninvented original grooved disk substrate replaces the primer layer that was conventionally coated on the substrate and formed the base layer of the photopolymer, and has excellent i&temporary adhesion properties.11! After conversion, a photopolymer exhibiting excellent thermophysical properties was used to form the first layer, and then a second mY type ff was formed using a photopolymer with good stand-bar releasability. In this case, it is desirable to provide an intermediate layer i' having good affinity for both layers between the first layer and @ 2 /1.

Further, in the manufacturing method of the present invention, after forming a first layer by coating a photopolymer with high layer density on the substrate,
A second layer is formed by laminating 7 Otobolima with good stamper M-type properties on the first layer, and a step of forming a grooved stamper on this second layer is performed, and the process is further performed to make the stamper optically transparent. 7: This is a method of curing both layers by irradiating ultraviolet plum from the e side.

[Effect]

According to the groove splicing source disk substrate and manufacturing method of the present invention, the photopolymer layer substrate has good layer properties and stamper removability, and furthermore, groove transferability, thermophysical properties, etc. are improved.

〔Example〕

Examples are shown below to clarify the effects of 4:@Ming.

Example 1 Polymethyl methacrylate (hereinafter referred to as PMM) with a thickness of 1.2H
As shown in Fig. 1, a layer (first layer) 23 of epoxy thread 7 otopolymer (3101 manufactured by Three Bond) was coated with a spinner to a thickness of 20 μm on a substrate (manufactured by Nitto Plastics Co., Ltd.) 2). On a PMMA substrate, a layer (second layer) 22 of polyol acrylate yarn 7 polymers having a thickness of 60 μm was formed using a nickel stamper (2PC photopolymer automatic transfer device (manufactured by Matsushita Electric) equipped with a grooved stamper mold). A nickel stamper was superimposed on this laminated 2P@tPMMAi[, and the substrate 2) was irradiated for 30 seconds with an ultra-high pressure mercury lamp (manufactured by Oak Manufacturing, 3kW).From the stamper to the substrate 2
) was peeled off to obtain a 2P transfer substrate (groove-joining source disk substrate).

Regarding this 2P transfer substrate, peeling of the 2P film was examined by cellophane tape test, but no peeling was observed.

Further, when the plume expansion rate of the 2P transfer substrate up to 120''C was measured, it was 7.5810-''C1, which was equivalent to that of the PMMA substrate. Furthermore, when the groove transferability was observed using a scanning electron microscope, the shape of the nickel stubber (groove pitch 1.6 μm, groove mo 8 μm, groove depth 700A)
It was rolling with great precision.

As a storage medium, a carbon disulfide plasma polymerized film co-deposited with tellurium was deposited to a thickness of 300 Å on this groove-forming disk substrate.
Wearing. When this original disk medium was rotated at lsoorpm and recorded with a semiconductor laser, the recording was just as good at 5 mw. Furthermore, when the original disc medium on which the data was recorded was played back at 3 mW, no hot water loss occurred in the medium. Also, regarding this original disk medium, the room temperature and 12
A temperature cycle test at 0°C was conducted, but no cracking or peeling of the medium was observed even after 200 cycles.

Comparative Example 1 A cured polyol acrylate photopolymer layer was formed on a PMMA substrate in the same manner as in Example 1 to obtain a 2P transfer substrate. Peeling of 2PPI4 was investigated by cellophane tape test and it was printed in a grid pattern. Comparative Example 2 On a PMMA substrate, lIkm epoxy thread photopolymer was applied in the same manner as in Example 1, and a nickel stamper was applied. The substrate was aligned, pressed using a tambo printing machine (manufactured by Nippon Bunka Seiko), hardened by an external machine, and the stamper was peeled off.
A transfer substrate was obtained. When the transfer substrate was observed under an optical microscope, cohesive failure of the cured EVO 1,000 cyanide polymer was observed and peelability was poor.

Comparative Example 3 A polyester primer (manufactured by Toyobo Co., Ltd., Byron) was applied to a thickness of 20 μm at f2! on a PMMA substrate. Detective, Real IIa
A 2P (polyol acrylate) transfer substrate was obtained in the same manner as in Example 1. The line Im! of this substrate at 120 °C9! The swelling rate was measured at 2×10°C. On this grooved substrate, a carbon disulfide plasma polymerized film co-deposited with tellurium was applied as a recording medium in the same manner as in Example 1. This original disk medium was subjected to a cycle test at room temperature and 120° C0). When the medium was observed after 200 cycles, cracks were observed in a part of the plasma stitch.

Example 2 A layer of epoxy photopolymer (first layer) with a thickness of 20 μm was coated on a glass substrate with a thickness of 1.2 mm using a spinner.Meanwhile, an adhesive dispenser (manufactured by Iwashita Engineering Co., Ltd.) was applied onto a grooved nickel stamper. Apply RFII [second layer] of polyol acrylate photopolymer, align the center with the glass substrate coated with epoxy photopolymer, press the edges with a tanbo printing machine, and expose from the glass substrate side.

hardened. The 2P transfer substrate peeled off from the stamper was examined for peeling IQ at 2pHg by cellophane tape test, but no peeling was observed.

Example 3 Similar to Example 1, a layer of epoxy-based 7 otobolima (@ 1
A photosensitive silicone resin (photoinitiator) made of Suzui acryloxyglobylated polydimethylsiloxane (manufactured by Shin-Etsu Higaku Co., Ltd.) with a thickness of 40 μm was applied to a PMMA substrate coated with 71) using a 2P automatic transfer device.

Benzoin isopropyl ether 3 IN (No. 271
) is formed, irradiated with ultraviolet rays from the substrate side, cured, and removed from the stamper to the substrate? A 2P transfer substrate was obtained by peeling.

No peeling was observed in the Sellotape test.

Furthermore, the groove transferability was also good.

A carbon disulfide plasma polymerized film coated with tellurium was attached to this grooved substrate. When recording was performed using a semiconductor laser while rotating at 1800 rpm, recording was possible at 4 mw. The reason why the polyol acrylate photopolymer of Example 1 also had high sensitivity is thought to be due to the low surface energy (wettability) of the photopolymer acting on the melting and evaporation of the plasma polymerized film.

Example 4 Similar to the practical example (see Figure 2), 3 temporary PMMA bases 3
1. The jfi CM 1 layer of xy-based photopolymer 33 was strained, and the jfti (middle m) 34 made of borietherene glycol diacrylate was further reduced to 10 μm.
This substrate was coated with a 30μn 1ffj layer of polyol acrylate film (@2Ni332) containing methacrylic heptafluorobutyl monomer Y2Ll in a 2P automatic transfer device, and irradiated with an ultra-high pressure mercury lamp for 40 seconds on a nickel stamper. [Substrate]?: Obtained. When recording was performed on this with the recording film of Gani and colleagues, gcEf was recorded at 4 mW at 5 aoorpm using a semiconductor laser.
i was 0]. In addition, the temperature is 60°C, the humidity is 1190°C,
I wore it under the sun for 20 days, but the media showed no peeling or cracking.

In addition, in the above IM example, when providing the intermediate layer 34, the trap, the first layer, the intermediate layer, and the second layer are laminated in this order, and the standby layer t1 is placed on top of the second layer 34, but the present invention is not limited to this. Instead of 1, for example, stack the first pigeon and intermediate + fi on the i board! :s @2 layers for this? Laminated stand bars may be stacked on top of each other. Alternatively, only the first layer (Y:m) may be formed on the substrate, and the second layer and the intermediate layer may be laminated thereon and then stacked together.

〔Effect of the invention〕

As explained above, the grooved optical disk substrate of the present invention includes a first layer having high adhesion on the substrate, and
Since the 2nd f layer with a good standby mold release property of 4° is provided on this @1 layer, the sensitivity depends on this structure, and it is expected that the sensitivity of the single-source recording medium (especially with holes) will be increased. , high-sensitivity recording and reproducing characteristics?M. Photopolymers that can be used for these are not limited to epoxy, polyol acrylate, photo-monotropic siloxane, and epoxy acrylate.

There are many types such as polyester acrylate and urethane acrylate, and by combining them, a grooved original disk suitable for various substrates and media can be obtained.

f7S: According to the manufacturing method of the present invention, after forming the first layer with a photopolymer having high adhesion to the substrate, a 27th #/z layer is formed on this with a photopolymer having good stamper releasability. process and grooved stand bar tJj on top of this second layer.
We carry out various types of work, and furthermore.

The first layer is irradiated with ultraviolet light from the optically transparent side.

Since the second layer is hardened, it is possible to transfer 1m and adhere to the substrate.

Stamper trend type T! , 14-piece original disk board that simultaneously satisfies Kaede's thermophysical notes, etc.? Obtainable.

[Brief explanation of drawings]

Figure 1 is a schematic cross-sectional view showing the symptoms of this disease, and Figure 2 is another example. Schematic Wr south map shown, Figure 3 and No. 4
The figure is a schematic cross-sectional view of a conventional original disk substrate. 2). 31°...Substrate, 23.33...First layer (photobo+)-rr@), 22t32...Second layer (photopolymer layer, 34...Intermediate layer. 22: Second layer 31 : Base 32: 2nd layer

Claims (3)

[Claims] (1) In an optical disk substrate in which a photopolymer layer is laminated on a substrate and grooves are formed in this photopolymer layer using a grooved stamper mold, the photopolymer layer is laminated directly on the substrate and 1. A grooved optical disk substrate comprising: a first layer having high adhesiveness to the substrate; and a second layer laminated on the first layer and having good stamper releasability. (2) The second layer is laminated on the first layer via an intermediate layer having good affinity for the first layer and the second layer. Grooved optical disk substrate as described in Section 1. (3) In a method for manufacturing an optical disk substrate in which grooves are formed in a photopolymer layer on a substrate, a photopolymer having high adhesion to the substrate is coated on the substrate to form a first layer, and then, a step of laminating a photopolymer with good stamper releasability on the first layer to form a second layer;
A method for producing a grooved optical disk substrate, comprising the steps of stacking a grooved stamper on the layer, and then curing the photopolymer layer by irradiating ultraviolet rays from the optically transparent substrate side.