JPH04265542A - Substrate for optical disk - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is directed to the production of 2P (Photo Polymeriz) on an optically transparent glass substrate.
photocurable resin (Pho cation) method.
to Polymer, hereinafter referred to as 2P resin. ) consisting of a guide groove and/or a concavo-convex pattern of a signal bit (hereinafter referred to as
This is called the 2P layer. ), and more specifically, the present invention relates to an optical disc substrate having excellent adhesiveness between a glass substrate and a 2P layer.

0002

[Prior Art] Three types of optical discs are known: read-only type, write-once type, and rewritable type, and read-only type and write-once type optical disks are already used in various fields. . The development of rewritable optical disks is also progressing rapidly, and magneto-optical disks in particular are about to enter the period of full-scale practical use.

[0003] As substrate materials for these optical discs, thermoplastic resins such as polymethyl methacrylate and polycarbonate, thermosetting resins such as epoxy resins, or glass are generally used. In addition, active research is also being conducted on new polyolefin resins that have characteristics such as low birefringence and low water absorption, especially as substrate materials for magneto-optical disks.

Nowadays, when it is necessary to transmit, process, and store a wide variety of enormous amounts of information, the performance required of optical disks as recording media is large capacity, high speed data transfer, and high reliability. The main focus of research is on these points. In order to achieve these advanced performances, the role played by the substrate material is extremely important.
In this sense, great expectations are placed on glass substrates.

For example, increasing capacity can be achieved by increasing the diameter of the substrate, but with polycarbonate substrates, which are currently the most commonly used, when the diameter is about 300 mm, mechanical properties such as surface runout occur when the disk rotates. This results in deterioration, making it difficult to cope with high-speed rotation (3600 rpm or more). In addition, it is difficult to control injection molding conditions,
There are drawbacks such as an increase in birefringence distribution in the circumferential direction. In this respect, glass is a substrate material with the best mechanical properties, and is advantageous for increasing the diameter without birefringence.

[0006] Furthermore, in order to speed up data transfer, research is being conducted to increase the disk rotation speed.
Recently, experiments have been conducted on high-speed recording of 5000 rpm or more. In this respect as well, glass substrates have much better dynamic mechanical properties than other plastic substrates, and glass substrates can be said to be optimal for high rotational speed recording.

Furthermore, glass substrates are excellent in stability under high temperature and high humidity conditions, and are the most reliable substrate material.

[0008] Generally, an uneven pattern such as a guide groove for guiding a laser beam or a preformat signal pit is formed in advance on an optical disk substrate, but in the case of a glass substrate, an uneven pattern is formed using 2P resin. The 2P method is known.

However, even if the 2P resin, which is an organic material, is directly formed on the glass, which is an inorganic material, a large adhesion force cannot be obtained between the two, resulting in the following disadvantages.

[0010] That is, during 2P molding, when the glass substrate is peeled off from the stamper (a molding die created by transferring from the master by electroforming), some or all of the hardened 2P resin remains on the stamper side. Otherwise, floating (an air space formed between the glass substrate and the 2P layer) frequently occurs in a part of the 2P layer formed on the glass substrate. In addition, even if the 2P molding is in good condition, cracks, wrinkles, and flakes will occur over time under high temperature and high humidity conditions.

In order to improve the above-mentioned problems, various studies have been made to improve the adhesive strength between glass and 2P resin. The most widely known method among these studies is to form a coating film of a primer made by diluting various silane coupling agents with an organic solvent on a glass substrate, and the following examples have been reported in the past. has been done.

For example, JP-A-62-139150 discloses that by providing an aminosilane primer layer diluted with toluene between a glass substrate and an epoxy resin layer, the adhesive strength between the two can be increased. Are listed.

In addition, JP-A-59-65953 discloses that a silane coupling agent having an acrylic group or a methacryl group is used, and an aromatic hydrocarbon, ether type, or ketone type with a boiling point of 120 to 200°C is used. , ester type,
It is described that a primer composition diluted with at least one type of polyhydric alcohol ester solvent and further added with an organic acid is effective.

Furthermore, JP-A-1-248335 also describes an example in which a primer composition in which ethene-based unsaturated silane is diluted with methyl alcohol is effective.

[0015]

[Problems to be Solved by the Invention] All of the conventional methods described above are effective to some extent in improving the adhesiveness between the glass substrate and the 2P resin. However, when continuous 2P molding is performed using a 2P resin that has excellent moldability, that is, good flowability (700 cps, 25°C or less) and good releasability from the stamper after curing, floating occurs partially. Peeling test (JIS, K5400,
8.52, Species Standard), defective products with a residual film rate ({total square area - peeling area} ÷ total square area) of 90% or less may be produced. These problems arise from insufficient initial adhesion between the glass substrate and the 2P resin.

Furthermore, due to this weak initial adhesive strength, minute undulations occur in the 2P layer when it is peeled off from the stamper, so that the axial acceleration exceeds the standard (20 m/sec2 or more).
In some cases, defective products may occur.

Furthermore, even if the initial adhesive strength is good, cracks, wrinkles, and flakes may occur over time under high temperature and high humidity conditions (eg, 80° C., 85% RH). As described above, in the conventional method of applying primer treatment on the glass substrate described above, the adhesive strength between the glass substrate and the 2P resin is insufficient, resulting in a high incidence of defective products during continuous molding. There was a problem with it being put away.

The problem to be solved by the present invention is to increase the adhesive strength between the glass substrate and the 2P layer of an optical disc substrate in which a 2P layer made of 2P resin is provided on a glass substrate, and to improve the continuity of the 2P method. The incidence of defective products during molding is low,
It is an object of the present invention to provide a highly reliable substrate for an optical disk in which the adhesive strength between a glass substrate and a 2P layer does not decrease even when kept in high temperature and high humidity for a long time.

[0019]

[Means for Solving the Problems] In order to solve the above problems, the present invention provides guide grooves and/or signal bits made of (1) a primer layer and (2) a photocurable resin composition on a glass substrate. An optical disc substrate having an uneven pattern, wherein the primer layer is a cured layer made of a primer layer constituent material containing an alkoxysilane having a methacrylic group, an acrylic ester, and a photopolymerization initiator. provide.

FIG. 1 is a sectional view of an optical disk substrate according to the present invention. In this figure, 1 is a disk-shaped glass substrate, 2 is a primer layer made of a cured mixture of an alkoxysilane having a methacrylic group, an acrylic acid ester, and a photopolymerization initiator, and 3 is a 2P layer.

As the glass substrate 1, glass such as chemically strengthened soda lime glass or soda aluminosilicate glass is suitable, and one processed into a disk shape is used.

The glass substrate is cleaned immediately before forming the primer layer 2 in order to remove organic matter or dust attached to the surface. Effective cleaning methods include scrub cleaning in pure water and detergent, ultrapure water cleaning, etc. using a 4 to 8 continuous automatic cleaning device. By performing this cleaning, organic substances, dust, etc. on the surface of the glass substrate are removed. This pretreatment allows the primer layer 2 to be uniformly applied onto the glass substrate, and eliminates unevenness in the adhesive force of the 2P layer 3 to the glass.

For the primer layer 2, a primer layer forming material containing an alkoxysilane having a methacrylic group, an acrylic ester, and a photopolymerization initiator is applied, the acrylic ester is cured by irradiation with ultraviolet rays, and then baked. Formed by doing.

Examples of the alkoxysilane having a methacryl group used in the present invention include γ-methacryloxypropyltrimethoxysilane. Examples of acrylic esters used in the present invention include polyester acrylates such as propylene oxide adipate acrylic acid and diethylene glycol trimetate acrylic acid; epoxy acrylates such as bisphenol A epichlorohydrin acrylic acid and phenol novolak epichlorohydrin acrylic acid; ethylene glycol adipic acid; Urethane acrylates such as tolylene diisocyanate 2-hydroxyethyl acrylate, polyethylene glycol tolylene diisocyanate 2-hydroxyethyl acrylate; monofunctional acrylate monomers such as 2-hydroxyethyl acrylate, phenoxyethyl acrylate, nonylphenoxyethyl acrylate; diethylene glycol diacrylate, neo Bifunctional acrylate monomers such as pentyl glycol diacrylate, 3-methylpentanediol diacrylate; trimethylolpropane triacrylate;
Examples thereof include trifunctional or higher functional acrylate monomers such as dipentaerythritol propionate tetraacrylate and dipentaerythritol hexaacrylate.

These acrylic esters can be used alone or in combination of two or more.

The blending ratio of alkoxysilane in the primer layer forming material is preferably in the range of 1 to 10% by weight, the blending ratio of acrylic ester is preferably in the range of 86 to 98% by weight, and the blending ratio of photopolymerization initiator is preferably in the range of 86 to 98% by weight. The proportion is preferably in the range of 1 to 4% by weight.

[0027] Furthermore, an organic solvent may be added for the purpose of improving the fluidity of the primer constituent material.

The organic solvent that can be added to the material constituting the primer layer is preferably one that forms a uniform solution and improves fluidity when mixed with the above-mentioned acrylic ester, and examples of such organic solvents include, for example. , aromatic hydrocarbons such as toluene, xylene, and benzene; ketones such as acetone and methyl ethyl ketone; esters such as ethyl acetate and n-butyl acetate; alcohols such as ethyl alcohol and isopropyl alcohol.

These organic solvents can be used alone or in combination of two or more.

The primer layer can be formed by a known coating method such as a spin coating method, a dipping method, or a spray method, but the spin coating method is preferred because it is highly mass-producible and can easily form a uniform coating film. Optimal. Furthermore, when forming a coating film by spin coating, the organic solvent in the primer can be dried by keeping the glass substrate rotating.

[0031] After applying the primer constituent material and curing the acrylic ester by irradiating it with ultraviolet rays, baking is performed. Baking is done in air at 100-200℃ for 10-60℃.
It is preferable to do this for about a minute.

The 2P layer 3 made of 2P resin is formed by the 2P method described below.

That is, on a stamper (a molding die made by transferring from a master by electroforming) on which a concavo-convex pattern such as a guide groove for guiding a laser beam and/or a preformat signal pit is formed, A glass substrate 1 is coated with liquid 2P resin, and the glass substrate 1 is placed so that the side on which the primer layer 2 made of a silane coupling agent is formed faces the stamper side, and pressure is applied to spread the uncured 2P resin. After curing the 2P resin by irradiating it with ultraviolet light from the side, it is peeled off from the stamper to form a 2P layer 3 having a desired uneven pattern.

2 used when forming the 2P layer of the present invention
Examples of the P resin include, for example, a photo-radical polymerization composition containing a photo-radical polymerizable prepolymer, a monomer, and a photo-radical polymerization initiator as main components; A photocationic polymerization composition as the main component; a composition that is cured by ultraviolet rays, such as a composition that is a mixture of a photoradical polymerization composition and a photocationic polymerization composition, and has good peelability from a stamper and transferability of uneven patterns after curing. It can be used without particular restrictions as long as it has good heat and humidity resistance.

[0035]

EXAMPLES The present invention will be explained in more detail below with reference to Examples and Comparative Examples.

(Example 1) Outer diameter 130mm, inner diameter 15m
A soda aluminosilicate glass substrate with a size of 1.1 mm and a thickness is subjected to scrub cleaning in pure water and detergent and ultrasonic cleaning in ultrapure water using a 5-pot automatic cleaning device. Organic substances and dust on the surface of the glass substrate were removed.

Within 30 minutes after washing, 3.0% by weight of γ-methacryloxypropyltrimethoxysilane, 30.0% by weight of ethylene glycol adipate tolylene diisocyanate 2-hydroxyethyl acrylate, xylene 6
A primer layer constituent material consisting of a mixture of 6.0% by weight and 1.0% by weight of hydroxycyclohexylphenyl ketone was applied onto a glass substrate by spin coating under the following conditions.

(Spin coating conditions) * Low speed rotation: 60 rpm, 14 seconds (primer application time: 10 seconds) * High speed rotation:
After applying the primer layer constituent material and drying the solvent under the above conditions at 2800 rpm for 30 seconds, UV rays were applied for 30 seconds.
The material constituting the primer layer was cured by irradiation at 0 mW/cm2 for 20 seconds. Next, in a clean oven, 10
Baking treatment was performed at 0°C for 1 hour.

Continuous molding was performed on the primer layer forming surface of the glass substrate on which the primer layer was formed by the above method using a 2P molding machine (manufactured by Dainippon Ink and Chemicals).
A P layer was formed. In this case, "STM-401" (manufactured by Dainippon Ink and Chemicals) was used as the 2P resin forming the 2P layer.

All 50 glass substrates on which the 2P layer was formed were in good molding condition, and during 2P molding, when the glass substrate was peeled off from the stamper, some or all of the hardened 2P layer was on the stamper side. Nothing remains,
In addition, no air bubbles (an air layer formed between the glass substrate and the 2P layer) were generated in a part of the 2P layer formed on the glass substrate.

[0041] In order to evaluate the initial adhesive strength between the 2P layer and the glass substrate, a cross-cut peel test (JIS, D-20
2, 8.121 type standard), the remaining film rate was 100% on all 50 glass substrates.

[0042] Also, even after the heat and humidity test at 80°C, 85% RH, for 2000 hours, the results of the cross-cut peeling test were as follows.
The remaining film rate was 100% for all 50 glass substrates.
No cracks, wrinkles, or flakes were observed in the 2P layer.

(Example 2) In Example 1, the primer layer constituent materials were 3.0% by weight of γ-methacryloxypropyltrimethoxysilane, 35.0% by weight of bisphenol A-epichlorohydrin acrylic acid, A primer layer and a 2P layer were formed on the surface of a glass substrate in the same manner as in Example 1, except that a primer layer constituent material consisting of a mixture of 61.0% by weight of xylene and 1.0% by weight of hydroxycyclohexylphenyl ketone was used. Example 1
The same evaluation was conducted.

As a result, the molding condition of all 50 glass substrates was good, and even in the grid peel test, 5
The remaining film rate was 100% for all glass substrates.

[0045] Also, even after the heat and humidity test at 80°C, 85% RH for 2000 hours, the results of the cross-cut peeling test were as follows.
The remaining film rate was 100% for all 50 glass substrates.
No cracks, wrinkles, or flakes were observed in the 2P layer on any of the substrates.

(Example 3) In Example 1, the primer layer constituent materials were 3.0% by weight of γ-methacryloxypropyltrimethoxysilane, 96.0% by weight of neopentyl glycol acrylate, and 1.0% by weight of hydroxycyclohexylphenyl ketone. A primer layer and a 2P layer were formed on the surface of a glass substrate in the same manner as in Example 1, except that a primer layer constituent material consisting of a mixture of % by weight was used, and the same evaluation as in Example 1 was performed.

As a result, the molding condition of all 50 glass substrates was good, and even in the grid peel test, 5
The remaining film rate was 100% for all glass substrates.

[0048] Also, the result of the cross-cut peeling test after the heat and humidity test at 80°C, 85% RH for 2000 hours was 49.
The remaining film rate for two glass substrates is 100%, and one glass substrate has a remaining film rate of 90% or more and less than 100%, and no cracks, wrinkles, or flakes are observed on the 2P layer on all substrates. There wasn't.

(Comparative Example 1) In Example 1, a primer layer constituent material consisting of a mixed solution of 1.0% by weight of γ-methacryloxypropyltrimethoxysilane and 99.0% by weight of toluene was used. ,2
A primer layer and a 2P layer were formed on the surface of the glass substrate in the same manner as in Example 1, except that 0 substrates were used, and the same evaluation as in Example 1 was performed.

As a result, out of 20 glass substrates, 11 were in good molding condition, and 9 glass substrates were in good condition.
When peeling off from the stamper during 2P molding, the hardened 2P
Part of the layer remained on the stamper side.

[0051] In order to evaluate the initial adhesive strength between the 2P layer and the glass substrate, a checkerboard peel test was conducted in the same manner as in Example 1, and the residual film rate was 20% for all 20 glass substrates.
It was below.

(Comparative Example 2) In Example 1, 1.0% of γ-methacryloxypropyltrimethoxysilane and 99.0% of n-butyl acetate were used as primer layer constituent materials.
Using a primer layer constituent material consisting of a mixed solution of 2.
A primer layer and a 2P layer were formed on the surface of the glass substrate in the same manner as in Example 1, except that 0 substrates were used, and the same evaluation as in Example 1 was performed.

As a result, out of 20 glass substrates, 13 were in good molding condition, and 7 glass substrates were in good condition.
When peeling off from the stamper during 2P molding, the hardened 2P
Part of the layer remained on the stamper side.

[0054] In order to evaluate the initial adhesive strength between the 2P layer and the glass substrate, a checkerboard peel test was conducted in the same manner as in Example 1, and the residual film rate was 20% for all 20 glass substrates.
It was below.

(Comparative Example 3) In Example 1, 1.0% by weight of γ-methacryloxypropyltrimethoxysilane and 99% of methyl alcohol were used as primer layer constituent materials.
．． A primer layer and a 2P layer were formed on the glass substrate surface in the same manner as in Example 1, except that a primer layer constituent material consisting of a 0% by weight mixed solution was used, and the same evaluation as in Example 1 was performed. .

As a result, all 50 glass substrates were found to be in good molding condition. In order to evaluate the initial adhesive strength between the 2P layer and the glass substrate, a checkerboard peel test was conducted in the same manner as in Example 1, and 15 sheets had a residual film rate of 100%, and 28 sheets had a residual film rate of 90%. or more and less than 100%,
Seven sheets had a residual film rate of 80% or more and less than 90%.

[0057] Also, the results of the cross-cut peeling test after the heat and humidity test at 80°C, 85% RH for 2000 hours were 35%.
13 sheets have a residual film rate of 80% or more and less than 90%, and 2 sheets have a residual film rate of 60%.
It was less than 70%. Furthermore, in 28 substrates, the occurrence of floating in the 2P layer was observed.

(Comparative Example 4) In Example 1, 1.0% by weight of γ-methacryloxypropyltrimethoxysilane and 99% of ethyl alcohol were used as primer layer constituent materials.
．． A primer layer and a 2P layer were formed on the glass substrate surface in the same manner as in Example 1, except that a primer layer constituent material consisting of a 0% by weight mixed solution was used, and the same evaluation as in Example 1 was performed. .

As a result, all 50 glass substrates were found to be in good molding condition. In order to evaluate the initial adhesive strength between the 2P layer and the glass substrate, a grid peel test was conducted in the same manner as in Example 1, and 18 sheets had a residual film rate of 100%, and 22 sheets had a residual film rate of 90%. or more and less than 100%,
Ten sheets had a residual film rate of 80% or more and less than 90%.

[0060] In addition, the results of the cross-cut peeling test after the heat and humidity test at 80°C, 85% RH for 2000 hours were 33.
13 sheets have a residual film rate of 80% or more and less than 90%, and 4 sheets have a residual film rate of 60%.
It was less than 70%. Furthermore, in 31 substrates, the occurrence of floating in the 2P layer was observed.

(Comparative Example 5) In Example 1, the materials constituting the primer layer were 1.0% by weight of N-β-(aminoethyl)γ-aminopropyltrimethoxysilane and 99% by weight of water.
．． A primer layer and a 2P layer were formed on the glass substrate surface in the same manner as in Example 1, except that a primer layer constituent material consisting of a 0% by weight mixed solution was used, and the same evaluation as in Example 1 was performed. .

As a result, out of 50 glass substrates, 46 were in good molding condition, and 4 glass substrates were
When peeling off from the stamper during 2P molding, the hardened 2P
Part of the layer remained on the stamper side.

In order to evaluate the initial adhesive strength between the 2P layer and the glass substrate, a grid peel test was conducted in the same manner as in Example 1, and 8 sheets had a residual film rate of 80% or more and less than 90%.
Ten sheets had a residual film rate of 70% or more and less than 80%, and 32 sheets had a residual film rate of less than 70%.

[0064] Also, the results of the cross-cut peeling test after the heat and humidity test at 80°C, 85% RH for 2000 hours were as follows:
The remaining film rate was 50% or less for all the glass substrates. Furthermore, in 28 substrates, the occurrence of floating in the 2P layer was observed.

(Comparative Example 6) In Example 1, a primer layer constituting material consisting of a mixed solution of 1.0% by weight of γ-aminopropyltriethoxysilane and 99.0% by weight of water was used. Other than that, Example 1
In the same manner as above, a primer layer and a second layer are formed on the surface of the glass substrate.
A P layer was formed and the same evaluation as in Example 1 was performed.

Among the 50 glass substrates, 42 were in good molding condition, and 8 glass substrates had a part of the hardened 2P layer on the stamper side when peeled from the stamper during 2P molding. It remained.

[0067] In order to evaluate the initial adhesion between the 2P layer and the glass substrate, a cross-cut Cellotape peeling test was conducted in the same manner as in Example 1, and six pieces had a residual film rate of 80% or more and less than 90%. Thirteen sheets had a residual film rate of 70% or more and less than 80%, and 31 sheets had a residual film rate of less than 70%.

[0068] Furthermore, the results of the cross-cut peeling test after the heat and humidity test at 80°C, 85% RH for 2000 hours were as follows:
The remaining film rate was 50% or less for all the glass substrates. Furthermore, in 36 substrates, the occurrence of floating in the 2P layer was observed.

(Comparative Example 7) In Example 1, the primer layer was composed of a mixed solution of 1.0% by weight of N-phenyl-γ-aminopropyltrimethoxysilane and 99.0% by weight of water. A primer layer and a 2P layer were formed on the surface of a glass substrate in the same manner as in Example 1, except that the materials were used, and the same evaluation as in Example 1 was performed.

Among the 50 glass substrates, 31 were in good molding condition, and 19 glass substrates had a part of the hardened 2P layer on the stamper side when peeled from the stamper during 2P molding. It remained.

[0071] In order to evaluate the initial adhesive strength between the 2P layer and the glass substrate, a checkerboard Cellotape peeling test was conducted in the same manner as in Example 1, and 6 pieces had a residual film rate of 70% or more and less than 80%. Ten sheets had a residual film rate of 60% or more and less than 70%, and 34 sheets had a residual film rate of less than 60%.

[0072] Furthermore, the results of the cross-cut peeling test after the heat and humidity test at 80°C, 85% RH for 2000 hours were as follows:
The remaining film rate was 50% or less for all the glass substrates. Furthermore, in 50 substrates, the occurrence of floating in the 2P layer was observed.

(Comparative Example 8) In Example 1, a mixed solution of 1.0% by weight of γ-glycidoxypropyltrimethoxysilane, 99.0% by weight of water, and 0.1% by weight of acetic acid was used as the material constituting the primer layer. A primer layer and a 2P layer were formed on the surface of a glass substrate in the same manner as in Example 1, except that 20 substrates were used, and the same evaluation as in Example 1 was performed. Ta.

Among the 20 glass substrates, 7 were in good molding condition, and 13 glass substrates had a part of the hardened 2P layer on the stamper side when peeled off from the stamper during 2P molding. It remained.

[0075] In order to evaluate the initial adhesion between the 2P layer and the glass substrate, a grid cellophane peeling test was conducted in the same manner as in Example 1, and the residual film rate was 20% for all 20 glass substrates. It was below.

(Comparative Example 9) In Example 1, the primer layer constituent materials were 1.0% by weight of γ-mercaptopropyltrimethoxysilane, 99.0% by weight of water, and 0% of acetic acid.
．． A primer layer and a 2P layer were formed on the surface of a glass substrate in the same manner as in Example 1, except that a primer layer constituent material consisting of a 1% by weight mixed solution was used and 20 substrates were used. The same evaluation was conducted.

Among the 20 glass substrates, 6 were in good molding condition, and 14 glass substrates had a part of the hardened 2P layer on the stamper side when peeled from the stamper during 2P molding. It remained.

In order to evaluate the initial adhesion between the 2P layer and the glass substrate, a grid cellophane peeling test was conducted in the same manner as in Example 1, and the residual film rate was 20% for all 20 glass substrates. It was below.

(Comparative Example 10) A 2P layer was continuously formed on the surfaces of 10 glass substrates in the same manner as in Example 1 except that the primer layer was not formed. In all of the glass substrates, most of the cured 2P layer remained on the stamper side when it was peeled off from the stamper.

[0080]

Effects of the Invention The optical disc substrate of the present invention has a strong adhesive strength between the glass substrate and the 2P resin constituting the 2P layer, so the incidence of defective products during continuous molding using the 2P method is low, and it can withstand high temperatures and high humidity. In particular, since the adhesive strength between the glass substrate and the 2P layer does not decrease, it is possible to provide an optical disc substrate with high long-term reliability.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the basic structure of an optical disc substrate of the present invention.

[Explanation of symbols]

1 Glass substrate 2 Primer layer 3 2P layer

Claims (2)

[Claims] 1. An optical disk substrate having a concavo-convex pattern of guide grooves and/or signal bits made of (1) a primer layer and (2) a photocurable resin composition on a glass substrate, wherein the primer layer is made of a methacrylic base. 1. A substrate for an optical disc, characterized in that the cured layer is made of a primer layer constituent material containing an alkoxysilane having the following properties, an acrylic ester, and a photopolymerization initiator. [Claim 2] The content of alkoxysilane having a methacrylic group in the material constituting the primer layer is 1 to 10% by weight.
The content of acrylic ester is in the range of 86 to 9.
The photopolymerization initiator content is in the range of 8% by weight and 1 to 4% by weight.
2. The optical disc substrate according to claim 1, wherein the content of the optical disc is within a range of % by weight.