JPS62291729A - Optical information carrier - Google Patents

Abstract

PURPOSE:To obtain a film substrate which is transferred with the surface shape of a master disk with good accuracy with single constitution by using a resin compsn. to be quickly cured by UV ray curing or to be quickly cured by the combination use of UV ray radiation and heating. CONSTITUTION:The master disk 2 provided with rugged shapes corresponding to videos or sound signals or guide grooves for track servocontrol on one face and a master disk holding base 4 are fastened to each other at the rear surface of the master disk. A spacer 3 having the height adding 10-20% thickness as the amt. of contraction by curing to the thickness of the cured matter of the resin layer curable by UV rays is disposed to form a resin injecting part 1'. The liquid resin is then injected in a prescribed amt. into said part in such a manner that said resin is quickly cured by the UV ray radiation or the combination use of the UV ray radiation and heating to transfer the rugged shapes of the master disk with good accuracy. While UV light is radiated to the resin from a high-pressure mercury lamp 5, the entire part is rotated together with the master disk holding base 4 to maintain the parallelism of the two surfaces and to flatten the surfaces, i.e., to suppress the generation of the ripple-like ruggedness on the surfaces.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention provides a method for forming a film on the surface of a film-forming substrate having an uneven shape on the plate surface.
The present invention relates to an optical information carrier formed with a medium thin film whose optical state changes when irradiated with a laser beam, and particularly to an optical information carrier having a film-forming substrate suitable for obtaining excellent optical properties and mechanical properties.

[Conventional technology]

Conventionally, glass plates, transparent thermoplastic injection molded plates, ultraviolet curing resin plates, and the like have been used as film-forming substrates for organic information medium films depending on the purpose. Among these, glass plates have better heat resistance and moisture resistance than film-forming substrates made of other materials, but on the other hand, they have more than twice the relative strength and are more brittle, which poses problems in handling. Its versatility is limited and its use is limited to business use. In addition, thermoplastic injection molded plates have a small thickness and a large projected area, and the optical characteristics of the plate surface are affected by the flow of the molten resin and the delay in cooling and solidification at various parts of the plate surface. %, there is an increase in the birefringence index and an expansion in its fluctuation range. Furthermore, commonly used acrylic resins have high moisture absorption and moisture permeability, and are prone to deformation during storage and use of finished products and peeling off at the interface with the film formed on the surface, resulting in poor environmental resistance. In addition, due to its structure, the polycarbonate (414Jik) used in compact discs has a photoelastic coefficient that is about 20 times higher than that of acrylic resin, which increases the birefringence of the injection molded plate and the content of the plate surface. This is contributing to the expansion of the range of fluctuations.

A known example of the present invention in which fat is introduced is described in Japanese Patent Application Laid-Open No. 57-15235. The gist of the invention is shown in FIG. 2 as a schematic longitudinal cross-sectional view. In the figure, a master disc 18 having a concave-convex shape corresponding to a predetermined video or audio number or a guide groove for a track servo on one side is fastened to a master disc holding stand 20,
Spacers 19 having a height corresponding to the thickness of the ultraviolet curable resin layer are arranged as shown in the figure, and further spacers 1
A backing base material 17, for example, an acrylic resin plate, is placed on top of the backing base material 17 and the spacer 19.
Inject B ¥116'. Then, the resin 16' is cured by irradiating ultraviolet light from the high-pressure mercury lamp 21. In this way, the ultraviolet curing resin layer 16 is brought into contact with and integrated with the embankment base material 17. The shape on the surface of the master 18 is copied onto one surface, and the second surface is contacted with the backing base material 17 on the opposite surface. The ultraviolet curing resin layer 16, the master 18, and the spacer 19 are separated to obtain a film forming base '&22. Note that the Nikkei publication also describes an example of using a transparent master that allows ultraviolet rays to pass through, but this is also a variation of the above example, and the structure of the film-forming substrate 22, which is a finished product, is the same. In other words, in either method, a well-stretched base material 17 made of a transparent resin plate is used, an ultraviolet curing resin layer 16 is formed on one surface of the base material 17, and the uneven shape provided on the master 18 is transferred to this layer surface. ing.

・In other words, the presence of the dosing base material 17 is essential. This is due to the fact that it is difficult to create a board with a predetermined thickness of +4P using only the ultraviolet curable resin layer, but for this reason, the film forming substrate 22 has a double structure of the ultraviolet curable resin layer 16 and the machined base material 17. making it inevitable.

For this reason, the film-forming substrate has potential causes of deterioration of its optical properties and mechanical properties, thereby impairing economic efficiency.

[Problem that the invention seeks to solve]

The above conventional technology does not take into account the disadvantages of the double structure of the film-forming substrate, and the optical characteristics
There was a problem of obscuring the cause of the decline in iso-decreasing characteristics.

An object of the present invention is to provide an optical information carrier whose film-forming substrate is made of a single material. Resin m1y that hardens by irradiation or a combination of ultraviolet irradiation and heating
This can be achieved by using materials and creating a film-forming substrate by casting.

That is, in the present invention, the above-mentioned H1 resin and synthetic material are injected onto the surface of a master disc having irregularities of a predetermined shape, and the resin composition is cured by ultraviolet irradiation to transfer the irregular shape on the master disc. Alternatively, the resin composition is semi-cured by ultraviolet irradiation, the uneven shape on the master is transferred, and the semi-cured resin is further cured by heating to form a cured resin plate, which is used as a film forming substrate. It is something.

Here, as the resin composition material, the main component is an epoxy acrylate obtained by adding acrylic acid to bisphenol type epoxy mJ1vI or oil bleaching type epoxy 7JS, and contains an ultraviolet I box curing agent. , Must @VC
Depending on the situation, heat curing agents using peroxides, reactive diluents, crosslinking oligomers, other additives/JO agents, such as heat curing accelerators, 7 series surfactants, JJL combination inhibitors, thermoplastics The product is a resin composition, or a bisphenol type or alicyclic epoxy resin containing a curing agent, such as an onium salt, which generates cations upon irradiation with ultraviolet rays.

Depending on the requirements, compositions containing additives such as acid anhydrides such as hexahytomifthalic anhydride, tertiary amines, higher enteric fatty acids or their metal salts, and antifoaming agents are used.

[Effect]

In the present invention, a resin composition that is rapidly cured by ultraviolet curing or by a combination of ultraviolet irradiation and heating is used. A bottom film substrate can be obtained by accurately transferring the surface shape of a master having a predetermined uneven shape.

〔Example〕

First, the main points when carrying out the present invention will be explained, and then examples showing specific conditions will be described. The structure of the jig will be explained with reference to the schematic longitudinal cross-sectional view of FIG. A master disc 2, which has an uneven shape corresponding to a video or audio signal or a track servo guide groove on one side, and a master disc holding stand 4 are fastened together on the back side of the master disc, and an ultraviolet 1#4
Thickness of cured resin layer: α1mm Tg Ishi 15771
A spacer 5 having a height of 10% to 20% of the thickness is set to a predetermined value in Fll as shown in the figure.
The resin injection part 1' is formed by arranging the resin injection part 1'. Next, the injection S is made of the resin composition described above, is rapidly cured by ultraviolet irradiation or a combination of ultraviolet irradiation and heating, and is made to have a viscosity of 50 to 50 to accurately form the uneven shape of the master (for transfer purposes).
Inject the specified amount of liquid resin at 0 voise. Then, while irradiating ultraviolet spring light from the high-pressure mercury lamp 5, the entire master holding table 4 is rotated within a range of 50 to 500 times per minute, depending on the diameter ζ thickness of the cured resin plate, and the resin injection part 1'' The resin layer poured on each part has a uniform cylindrical shape, maintains parallelism on both sides, and also flattens the surface, that is, suppresses the occurrence of ripple-like unevenness on the surface.

In order to maintain uniformity in the height of the resin layer and to prevent the occurrence of ripple-like irregularities on the surface, as shown in Figure 5, one side of the quartz glass plate surface is coated with transparent silicone rubber with a thickness of 0.3 mm to 2 mm.
It is also possible to provide an upper restraining plate 6 having a rubber layer coated and cured.

Next, the power consumption per unit light emission length is 601g.
Ultraviolet spring light from a high-pressure mercury lamp of 20 to 6 cm
The resin in the resin injection part 1' is irradiated for 0 seconds to sufficiently harden the resin, and then the cured resin 1 is separated from the master 2 and used as a film-forming substrate or cured by ultraviolet irradiation. If curing does not proceed sufficiently after stopping inside the resin, heat for 30 minutes to 2 hours at a temperature within the range of 10°C to 120°C to fully cure the resin and obtain a cured resin plate. It can be used as a film formation substrate.

The hardened W fat material 1 obtained as described above has a depth Q of 08 mm, a width of 0.8 μm, and a length of 3 μm provided on the surface of the master 20.
It accurately captures the pit row. In addition, the surface hardness of the cured product is equivalent to 5H pencil lead, the total ft, the linear transmittance is 91 to 92 inches, and the refractive index is t495 to t50.
1. The birefringence index is 6 to 8 inches, and the variation range of the birefringence index at each part within the 20 cm diameter plate is within 2%.

Examples showing specific conditions will be described below.

Example 1: In this example, the casting jig shown in Figure i@1 was used.

The master disc 2 used here has bit rows arranged on its surface, and in order to facilitate mold release from the 01 hardened resin W1, the master disc 2 was manufactured using the patent application 1986-IL40 proposed by the inventors of the present invention.
The method described in the specification of 24-ff, that is, the master disk is exposed to high frequency excitation with nitrogen gas, ammonia gas containing nitrogen, or a gas mixed with helium and hydrogen, so-called 7 Ohming gas, etc. 2 A nitride layer is provided on the surface to increase hardness and improve mold release from cured resin material 1, thereby suppressing deformation of cured resin material 1 that would occur due to application of IIJM force during mold release. . Then, the surface of the master disc 20 is brought into contact with the master disc holder 4 and the two are fastened together, and a spacer with a height of aMli is placed so that the thickness of the cured resin is 12 mm in the configuration shown in Figure @1. Then, a resin injection part 1' is formed, and a tumor is injected into the injection part. The resin to be injected has a viscosity of 50 to 5
It is a solution resin composition adjusted to 00 poise, here 200 poise, and its composition is made by adding and reacting 1 equivalent of acrylic acid to 1 equivalent of epoxy group of 470 bisphenol A type epoxy. 60 parts by weight of epoxy acrylate, 10 parts by weight of 1,6 hexanediyl diacrylate, 10 parts by weight of trimethylolpropane triacrylate, 20 M parts of phenoxy ether acrylate, 1-2-a phenyl phenyl ketone 2'jjL Dobe, benzyl dimethyl ketal 1M Seibu, 1,1-bis(t-butyl peroxy)
It consists of 11 parts of s, s, 5 trimethylcycloa hexane, etc.
O-ITorrtlC is stirred in a vacuum tank to remove gases such as night air and moisture dissolved in the resin composition liquid, and then injected into the resin injection part 1'. Then, the output 2K which is provided at a position 10C1rL away from the resin layer surface #
Ultraviolet light is irradiated from a high pressure mercury lamp 5 of 7 (801 F'/cm 2 ) and held for 30 seconds to harden the resin. The hardness of the thus obtained quadruple cured product in terms of pencil lead is F to H.
Furthermore, the monomer residual rate is 5 to 7%, and is still in a semi-cured state without being fully cured, but the master 2 and spacer 5
The deformation that occurs in the semi-cured resin plate is slight under the load caused by the separation. The thus obtained semi-cured gR resin plate was subsequently heated at a temperature of 95 to 105°C for 60 minutes,
It is sufficiently hardened to 2H to 3H when the lead core change ay>h height.

The concave and convex shape transfer of the thus obtained cured resin material 1 to the master disk 2 was good, and the original transmittance was 90 to 91%.
, the refractive index is t501, the birefringence is about 13 degrees, and the diameter is 2.
The range of variation in each part of the 0 ctn board was 2 degrees at most, and the difference in reflection between the concave and flat parts of the board was 13 degrees.

Example 2: A cured resin product 1 was obtained by changing the ultraviolet irradiation time to 60 seconds in Example 1 and keeping all other conditions the same.

The hardened dark fat proboscis 1 thus obtained had a pencil lead equivalent hardness of 3H, and the uneven shape copied from the master disc 2 was good.

Moreover, the parallelism and straightness of the front and back surfaces of the cured resin material 1 were slight. Furthermore, the optical properties were comparable to those of Example 1.

〔Effect of the invention〕

According to the present invention, in the optical information carrier, the birefringence is small and the birefringent heavy hIl is present at each location within the plate surface.
lW's small size! 14! The substrate can be easily obtained with a simple structure made of a single material using a cured resin, and the time required to separate this film-formed substrate from the mold is short, less than 1 minute, making it economical. Excellent.

[Brief explanation of the drawing]

FIG. 1 is a schematic M cross-sectional view showing the back-cropping situation and product situation of the film-forming substrate of the optical information carrier according to the present invention, and FIG. FIG. 3 is a schematic vertical cross-sectional view showing a first example of gradual deformation. Explanation of symbols 1...Resin cured product 1'...Resin injection part 2.
...IJK board S...Spacer 4...Master disk holding stand 5...Island pressure mercury lamp 6...
・Top restraint plate closed 1 figure, 2 figures, penalty 5 figures

Claims (1)

[Claims] 1. A resin composition that is cured by ultraviolet irradiation or a combination of ultraviolet irradiation and heating is injected onto the master surface having irregularities of a predetermined shape, and the resin composition is cured by ultraviolet irradiation. , a resin cured product obtained by transferring the uneven shape on the master disk, or semi-curing the resin composition by irradiating with ultraviolet rays, transferring the uneven shape on the master disk, and then curing the semi-cured resin by heating. An optical information carrier characterized in that it has a structure in which a plate is formed, and a medium thin film whose optical state changes by laser beam irradiation is formed on the uneven transfer surface using the plate as a film-forming substrate. 2. In the optical information carrier according to claim 1, the cured resin plate has a thickness of 0.1 mm to 0.15 mm.
An optical information carrier comprising a single cured resin of an acrylate composition or an epoxy composition in the range of mm.