JPH027246A - Production of optical disk - Google Patents

Abstract

PURPOSE:To improve the adhesive strength between a transparent resin substrate and thin dielectric film and to prevent the exfoliation of the thin dielectric film consisting of a nitride, oxide, etc., by subjecting the transparent resin substrate to a silane coupling agent treatment, then forming the thin dielectric film thereon. CONSTITUTION:A soln. prepd. by adding water to a methanol soln. of N-(2- aminoethyl)-3-aminopropyl trimethoxysilane is coated on the grooved surface of the transparent resin substrate 1 consisting of a polycarbonate resin by the spin coating method and is heat-treated. A thin silicon nitride film (i.e., thin dielectric film) 3 is thereafter formed by sputtering thereon. The surface of the transparent resin substrate is then coated with the silicon compd. having the network molecular structure in which silicon and oxygen are bonded. The adhesive strength between the transparent resin substrate and the thin dielectric film is improved in this way.

Description

[Detailed Description of the Invention] [Industrial Use ￥f] The present invention relates to a method for manufacturing optical discs used under the names of compact discs, video discs, recordable discs, rewritable discs, etc. This invention relates to improving the adhesion between a protective dielectric thin film and a transparent resin substrate.

[Conventional Technique 1] Taking magneto-optical disks as an example of optical disks,
A magneto-optical disk is an information recording medium that records and reproduces information using the magneto-optical properties of a magnetic material.It has a structure in which a thin film of magnetic material such as an amorphous alloy is formed on a transparent resin substrate. In order to enhance the optical effect, the first
For example, the magneto-optical disk 1 shown in the figure has a transparent resin substrate 2, a transparent dielectric thin film 3, a magnetic thin film 4, and a transparent dielectric thin WA5. , and a protective resin layer 6 are formed in this order. Conventionally, in manufacturing this type of magneto-optical disk, the dielectric thin film 3 in contact with the transparent resin substrate 2 was directly formed by sputtering or the like on the surface of the transparent resin substrate 2 as formed without any treatment.

[Problems to be Solved by the Invention] However, the transparent resin substrate 2 is made of an organic polymer such as polycarbonate, and the dielectric thin film 3 formed thereon is made of inorganic ceramics such as silicon nitride or yttrium oxide. The adhesion between the resin substrate 2 and the dielectric thin film 3 was weak, and peeling was likely to occur.

The present invention has been made in order to eliminate the above-mentioned conventional drawbacks, and is a method for manufacturing an optical disk that can obtain an optical disk that has strong adhesion between a transparent IA resin substrate and a dielectric thin film, and does not cause peeling between the two. The purpose is to provide

[Means for Solving the Problems] The method of the present invention for solving the above problems is to form mV of a silicon compound by applying and reacting a silane coupling agent on a transparent resin substrate, and to apply the dielectric Fill on the mV of a silicon compound.
It forms the

Note that the silane coupling agent means an organosilicon compound having two or more types of functional groups, and is represented by the following general formula.

In addition, R is an alkyl group, and X is various organic functional groups.

[Function] When a silane coupling agent is applied to a transparent resin substrate made of an organic polymer, the surface of the transparent resin substrate is covered with a silicon compound having a network molecular structure in which silicon and oxygen are bonded, as will be described later. This silicon compound having a network molecular structure has extremely good adhesion to nitrides and oxides formed thereon.

The reaction in which the silicon compound having the above-mentioned network molecular structure is produced will be described. The surface of a transparent resin substrate usually contains a small amount of water, just as many solid objects in a normal environment contain water. Therefore, a transparent resin substrate has a hydroxyl group (-0H) on its surface, and if the transparent resin substrate is made of, for example, polycarbonate resin or polymethyl methacrylate resin, it usually has a hydroxyl group (-0H) on its surface. Although it is only a small part,
Carboxyl groups (-COoll) produced by decomposition are actually present.

On the other hand, when water is added to the tM-structured silane coupling agent shown in (1) above, a silane coupling agent having a structure having a hydroxyl group (-01-1) as shown below is produced by hydrolysis.

Therefore, when the above-mentioned silane/sampling agent is applied to the surface of a transparent resin substrate having hydroxyl groups or carboxyl groups, the hydroxyl groups of the silane/sampling agent react with the hydroxyl or carboxyl groups of the transparent resin substrate, resulting in dehydration condensation. Further, dehydration condensation occurs between the silane coupling agents, and a silicon compound having a network structure in which silicon and oxygen are bonded as shown in FIG. 2 is produced.

This silicon arsenic material having a network molecular structure covers the surface of the transparent resin substrate and improves its adhesion to the dielectric thin film.

[Example] The present invention will be explained in detail below.

1st Example Group iF of transparent resin substrate made of polycarbonate resin
, N-(2-aminoethyl)-3-aminopropyl)
・Rime 1 hexysilane 10-1% methanol 17
A mixture of water in a molar amount 6 to 15 times the molar amount of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane was added to Solution I by a spin cord method, and 80%
Heat treatment was performed for 5 to 30 minutes at a temperature of 100°C to 100°C. A silicon nitride thin film (ie, dielectric thin film) was formed thereon by sputtering.

The above-mentioned spin cord method is a method in which a coating liquid is dripped onto the inner periphery of a rotating substrate, and centrifugal force spreads the coating liquid toward the outer periphery of the substrate to coat the entire substrate.

Second Example A 10 to 1% ethanol solution of 3-aminopropyltriethoxysilane was added to a group surface of a transparent resin substrate made of polymethyl methacrylate resin in an amount of 6 to 15 times the mole of 3-aminopropyltriethoxysilane. The coating was coated using a spin cord method, and heat treated at 80 to 100°C for 5 to 30 minutes. Second, a thin yttrium oxide pattern (Zunawaji Electron Thin 1 pattern) was formed by sputtering.

Third Example In the first and second examples above, the silane coupling agent was applied onto a transparent resin substrate by a spin cord method in hot air at 80 to 100°C. That is, instead of a separate heat treatment, it was applied in hot air.

Fourth Example In the same manner as in the first and second examples above, the silane coupling agent was sprayed onto the transparent resin substrate and heat treated.

Fifth Example In the first and second examples above, the silane coupling agent was applied onto the transparent resin substrate by spraying in hot air at 80 to 100'C.

Sixth Example In the first and second examples above, the silane coupling agent was applied onto a transparent resin substrate with a brush and heat treated.

Seventh Example In the first and second examples above, the silane coupling agent was applied onto a transparent resin substrate with a brush in hot air at 80 to 100°C.

Eighth Example In Examples 1 to 7 above, the transparent resin substrate was irradiated with ultraviolet rays from a low-pressure mercury lamp for 5 to 30 minutes, and then coated with a silane coupling agent.

Ninth Embodiment In the first to seventh embodiments described above, a silicon nitride thin film or yttrium oxide film was formed on the surface of a transparent resin substrate by applying the silane coupling agent onto a transparent resin substrate using a low-pressure mercury lamp. Regarding thin film 1, silicon nitride thin film or yttrium oxide N JB! was formed directly on a transparent resin substrate according to the conventional method. A beer test (peel test) was conducted for each of these, and both the examples of the present invention and the conventional example were compared. This beer test
In this test, a grid-like scratch is made with a knife in a 10 mm x 10 m r area on the surface of the sample with an interval of 1 min in length and width, Scotch tape is applied to the surface, and then it is peeled off.

” Regarding the results of the two-leg peel test, the dielectric thin film produced by the conventional method was completely peeled off, whereas the dielectric thin film produced by the method of the present invention did not peel off at all in most cases, and only in a few cases. However, peeling of less than a few percent occurred. In this way, results clearly showing that the adhesion was improved were obtained.

It should be noted that each of the embodiments described above can be quickly applied to the production of optical discs such as production of magneto-optical discs (D).

That is, in the case of a CD, a thin aluminum film or the like is formed as a reflective film on the pill and surface of a transparent resin substrate, and a protective layer is formed thereon. It is also conceivable to form a ceramic or dielectric thin film 13 between the aluminum thin film 12 and the aluminum thin film 14.

This is to prevent corrosion of aluminum due to penetration of moisture and oxygen from the outside, since it is normally not possible to completely prevent penetration of moisture and oxygen from the outside into a transparent resin substrate made of an organic polymer over a long period of time. In addition, 11 is an optical disk, 15 is a protective layer, and the dielectric weight J in this case
In order to improve the adhesion between the Bi 13 and the transparent resin substrate 12, it is possible to apply the present invention described above.

[Effects of the Invention] As described above, according to the present invention in which a dielectric thin film of nitride or oxide is formed after a transparent resin substrate is treated with a silane coupling agent, the transparent resin substrate and the dielectric r! JJg! It is possible to obtain an optical disk in which the adhesion with the dielectric thin film is improved and the dielectric thin film does not easily peel off.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional diagram of a general magneto-optical disk, and Figure 2 is an explanation of the structure of a silicon compound with a wire-like structure [2+,
FIG. 3 is a cross-sectional configuration diagram of the optical disc. DESCRIPTION OF SYMBOLS 1... Magneto-optical disk, 2.12... Transparent resin substrate, 3.13... Dielectric weight n, 11... Optical disk.

Claims (1)

[Claims] 1. A method for manufacturing an optical disk having a dielectric thin film on a transparent resin substrate, in which a silane coupling agent is coated on the transparent resin substrate and reacted to form a thin film of a silicon compound; A method of manufacturing an optical disc, comprising forming the dielectric thin film thereon. 2. A polycarbonate resin, a polymethyl methacrylate resin, or a copolymer thereof is used as the transparent resin substrate, an amino-based silane coupling agent is used as the silane coupling agent, and a nitride is used as the material of the dielectric thin film. 2. The method for manufacturing an optical disc according to claim 1, characterized in that an oxide is used. 3. The method for manufacturing an optical disc according to claim 2, wherein the silane coupling agent contains N-(2-aminoethyl)-3-aminopropyltrimethoxysilane. 4. The above silane coupling agent is N-(2-
A molar amount of 6 to 15 times the molar amount of the N-(2-aminoethyl)-3-aminopropyltrimethoxysilane is added to a 10 to 1% by weight ethanol or methanol solution of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane. Claim 3, characterized in that the product is prepared by adding water and stirring.
A method of manufacturing the magneto-optical disk described above. 5. The method for manufacturing an optical disc according to claim 2, wherein the silane coupling agent contains 3-aminopropyltriethoxysilane. 6. The silane coupling agent is prepared by adding water in a molar amount 6 to 15 times the molar amount of the 3-aminopropyltriethoxysilane to a 10 to 1% by weight ethanol or methanol solution of 3-aminopropyltriethoxysilane. 6. The method for manufacturing an optical disc according to claim 5, wherein the optical disc is stirred.