JP3081082B2 - Optical information medium and surface printing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information medium capable of printing on a surface opposite to a surface on which reproduction light is incident using printing ink, and a method of printing on the surface.

[0002]

2. Description of the Related Art At present, an optical information medium (hereinafter, referred to as a "CD") having the name of a compact disk is widely used in the fields of audio and information processing. This CD
Is provided with a reflective layer by depositing gold or aluminum on a substrate made of a donut-shaped disc such as polycarbonate,
Further, the structure is covered with a protective layer such as an ultraviolet curable resin. The data is recorded by forming uneven pits according to a spiral arrangement on the surface of the substrate, and the pits are formed in advance according to a mold such as a stamper when forming the substrate. In addition, the reflection layer is provided thereon. Therefore, when this CD is manufactured, data is already recorded on it, and it is used as a read-only optical information medium.

[0003] In this CD, an index display indicating the content recorded on the CD and various designs are printed on the surface of the protective layer with ultraviolet curable ink or oil-based ink.
These printings are usually performed by printing means such as screen printing, tampo printing or offset printing, which is performed by transferring a plate. These printing means are printing means suitable for so-called high-volume printing, in which a large number of the same patterns are printed at the same time.

[0004] On the other hand, as symbolized by the so-called karaoke boom, self-performance by amateurs has increased, and as the base has expanded, the activity of amateur players to make a relatively small number of self-made CDs has also become active. These self-made CDs
Are created, for example, for promotion, for audition, for testing, or for self-publishing. In particular, a write-once optical information medium such as a so-called CD-WO, which can be recorded once using a laser and the recorded content can be reproduced by a CD player, has been developed. It can be easily made. In the field of computers, so-called C
With the widespread use of D-ROMs and the spread of so-called write-once optical information media, users have come to use CD-WO to create their own CD-ROMs.

[0005]

The protective layer of an optical information medium such as a self-made CD made in this manner has nothing written or has a common character or pattern with ultraviolet curable ink or oil-based ink. It is only printed, and before or after recording personal information on the optical information medium, the index of the recorded content and, if necessary, other designs are displayed on the surface of the protective layer or the printed surface of the label. Need arises.

However, the above-mentioned printing means prints in a manufacturing process after providing a protective layer, and since both the surface of the protective layer and the printed surface are hydrophobic, after printing personal information, Excessive equipment is required to print on the surface of the protective layer, and it is difficult to freely print any information personally. Therefore, generally, a method of writing on the surface of the protective layer using an oil-based felt pen or the like, or a method of attaching a label or the like to perform display is used. However, since it is necessary to write by hand one by one, it is troublesome, and the drawn pattern and the drawing quality vary. Was. In particular, when a label is attached, there is a problem that the display surface rises by the thickness of the label, causing eccentricity and surface blurring of the optical information medium at the time of reproduction or additional recording.

The present invention has been made in view of such conventional problems, and firstly provides an optical information medium capable of easily and satisfactorily forming certain characters and patterns on the surface of a protective layer of the optical information medium. The purpose is to: Secondly, it is an object of the present invention to provide a printing method for an optical information medium capable of printing a fixed number of characters and designs easily and with a substantially constant quality on the surface of the optical information medium for a relatively small number of optical information media. I do.

[0008]

That is, in order to achieve the first object, the means employed in the present invention is formed on a plate-shaped translucent substrate by directly or through another layer. An optical information medium having a protective layer made of a cured resin and capable of reproducing and / or recording information optically readable by a laser beam, wherein an ultraviolet ray is applied to the rear surface of the light-transmitting substrate on the side where the reproduction light is incident. Protective layer made of curable resin
Is formed on the protective layer, a hydrophilic resin film capable of fixing an aqueous printing ink on the surface thereof has a layer boundary with the protective layer.
This hydrophilic tree is formed in an integrated binding state.
The surface of the oil film is characterized by being a fine rough surface . Further, the present invention is characterized in that the aqueous ink is fixed on the surface of the hydrophilic resin film of the optical information medium, and display is performed.

A preferred embodiment of the optical information medium is as follows. The protective layer of the CD is made of an ultraviolet curable resin. In order to enhance the binding between the protective layer and the hydrophilic resin film, the ultraviolet curable resin forming the protective layer is
Hydroxyl group, carboxyl group,
It is preferable to contain an acryl group, an amino group or a vinyl acetate group, or to contain a chlorine group in the main chain or side chain of the crosslinked product.

The resin forming the hydrophilic resin film includes polyethylene oxide, polyvinyl alcohol, polyvinyl methyl ether, polyvinyl formal, carboxyvinyl polymer, hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, sodium carboxymethylcellulose, polyvinylpyrrolidone,
It is desirable that the film be formed of a resin containing at least one of morpholine.

The surface of the hydrophilic resin film has an average roughness Ra
It is desirable but a rough surface 2.0～0.1Myuemu, Example
Its fine rough surface eg to either formed by dispersing a pigment in the hydrophilic resin film, or after the formation of the hydrophilic resin film,
It can be formed by roughening the surface.
Wear.

Further, in the present invention, in order to achieve the second object, as a method of printing on the surface of the optical information medium, the aqueous ink is ejected toward the surface of the hydrophilic resin film of the optical information medium as described above. Then, an ink is attached to the surface, and the aqueous ink is fixed on the surface, and a surface printing method for an optical information medium is provided. In this case, printing can be performed by an inkjet printer.

[0013]

In the optical information medium according to the present invention, the hydrophilic resin on which the printing ink can be fixed is provided on the back surface side on which the reproduction light is incident.
By forming the film , characters and designs can be arbitrarily drawn by any writing means such as a writing implement using an aqueous ink or a writing implement using an oil-based ink. Of course, it is also possible to use another method such as an ultraviolet curable ink.

An optical information medium having a display in which an aqueous ink is fixed on the surface of the hydrophilic resin film has a flat display surface as compared with a display in which a label or the like is applied to display. In addition, it is possible to prevent the occurrence of eccentricity, surface blur, and the like during reproduction and additional recording. The protective layer of the optical information medium is purple
Made from an external curing resin, a hydrophilic resin film on the protective layer, a layer boundary between the protective layer by <br/> Rukoto provided with binder condition that integral, improved protection of the protective layer . As a result, peeling of the hydrophilic resin film on the surface layer of the optical information medium occurs.
And a highly reliable optical information medium can be obtained. In addition, the provision of the hydrophilic resin film may cause a decrease in weather resistance.
In addition, the optical information medium may be warped even under normal use environment
Without deteriorating the recording / reproducing characteristics of the optical information medium.
No. The hydrophilic resin film is hygroscopic, but especially hydrophilic resin
The film is provided in a bonded state in which a layer boundary with the protective layer is integrated.
Water, the hydrophilic resin film absorbs moisture and absorbs ink.
Even if absorbed, these moistures can cause the protective layer and
Does not penetrate along strata. This allows moisture absorption on the protective layer
Even if a hydrophilic resin film with a property is provided,
Leaking can be reliably prevented.

As the hydrophilic resin film which does not meet such demands and improves the printability such as ink wettability and hydrophilicity, the above-mentioned polyethylene oxide, polyvinyl alcohol, polyvinyl methyl ether, polyvinyl formal, Carboxyvinyl polymer, hydroxyethyl cellulose, hydroxypropyl cellulose,
A film formed of a resin containing at least one of methylcellulose, sodium carboxymethylcellulose, polyvinylpyrrolidone, and morpholine can be given.

Since the surface of the hydrophilic resin film has a fine rough surface, the contact angle of the ink becomes smaller than when the surface is not rough, so that the ink adheres well and the printability is improved. Further, even when the optical information medium is handled by hand, fingerprints and the like do not adhere to the medium, so that the handleability is improved.

According to the surface printing method of the present invention in which the aqueous ink is jetted toward the surface of the hydrophilic resin film to adhere the ink to the surface and fix the aqueous ink on the surface, the protective layer Display can be performed on the surface of the optical information medium without damaging the substrate. In addition, the surface of the optical information medium becomes flat, and it is possible to prevent the occurrence of eccentricity, surface blur, and the like during reproduction and additional recording.

In particular, in a method of printing by ejecting ink by an ink jet printer, for example, characters and patterns to be printed by a personal computer are prepared in advance and can be printed repeatedly, so that there is little variation in print patterns and print quality. Easy to display.

[0019]

Next, embodiments of the present invention will be specifically described with reference to the drawings. FIG. 1 shows the optical information medium as viewed from the back side of the surface on which the reproduction light is incident.
Reference numeral 1 denotes a lower surface side in FIG. As shown in this figure, a hydrophilic resin film 26
Are formed. The hole provided at the center of the optical information medium is a clamp hole 4 for clamping with a clamper of a spindle when the optical information medium is set in a CD player.

FIG. 2 schematically shows a cross section of a so-called write-once type optical information medium as an example of the optical information medium. Translucent substrate 2 made of polycarbonate resin or the like
A guide groove 22 for tracking is formed in a spiral shape on 1, and a dye recording layer 23 is coated thereon. A reflective layer 24 made of a metal film such as gold, silver, or aluminum is formed on the dye recording layer 23, and a protective layer 25 is provided thereon. Further, a hydrophilic resin film 26 described later is formed on the protective layer 25. This parent
Rough surface processing and modification as described later on the surface of the aqueous resin film 26
Processing can also be performed.

[0021]

FIG. 4 is a sectional view showing a main structure of such a write-once-type printing apparatus that performs ink jet recording on the hydrophilic resin film 26 of the optical information medium, FIG. 3,
The holder 31 holds the optical information medium 2 when performing ink jet recording by such an apparatus.

The holder 31 is rectangular, and has a circular hole 33 at the center thereof, which is slightly larger than the outer diameter of the optical information medium 2, and a step portion 32 for holding the outer peripheral edge of the optical information medium 2 inside the hole. It is provided over the entire circumference. The depth of the step 3 is slightly smaller than the thickness of the optical information medium 2. For this reason, as shown in FIG. 3 , the optical information medium 2 is fitted into the hole 33 of the holder 31 with the hydrophilic resin film 26 side up, and the outer peripheral portion of the optical information medium 2 on the incident surface side of the reproduction light is moved. When supported by the step portion 32, the optical information medium 2 is held by the holder 31 so that the surface of the hydrophilic resin film 26 is slightly higher than the surface of the holder 31.

The optical information medium 2 held by the holder 31 is extended on a feed table 41 of a printing apparatus shown in FIG. 4 , and the rollers 42 and 43 are sent to a position where the rollers 42 and 43 hit the ends of the holder 31. When a printing signal is input to the printing apparatus from a computer or the like, the holder 3 is driven by driving the rollers 42 and 43.
1 is started. This optical information medium 2 is a table 4
A print head 44 is disposed just above the position where the ink passes over the surface of the optical information medium 2, and the print head 44 ejects particles of the printing ink onto the surface of the hydrophilic resin film 26 of the optical information medium 2.
Print characters and designs on the surface of the.

As described above, the printing apparatus shown in FIG. 4 is an ink jet printer for performing ink jet printing. In this type of printer, a plurality of thin print nozzles are arranged in a print head 44 as is well known. The print nozzle generates a bubble in the ink in the print nozzle by an electrothermal converter operated by an electric signal, for example, and ejects the ink from the nozzle tip. This allows
As described above, ink is attached to a predetermined position on the surface of the hydrophilic resin film 26 of the optical information medium 2 conveyed along the feed table 41.

The plate-shaped translucent substrate 21 used for the optical information medium 2 has a refractive index of 1.4 to laser light.
A resin having a high transparency in the range of 1.6 and having excellent impact resistance is used. Specifically, polycarbonate, polyolefin, acrylic and the like can be exemplified, but not limited to these. The translucent substrate 21 is formed using such a resin material by, for example, an injection molding method. As shown in FIG. 2, a spiral guide groove 22 or a tracking guide unit having another shape may be provided on the surface of such a translucent substrate 21. Such tracking guide means can be usually formed by a known method using a stamper.

This optical information medium has a portion for recording information optically readable by a laser beam or at least one of a recorded portion, for example, irradiating a laser beam. As used herein, it means a layer capable of optically reproducing or recording information, a substrate surface involved in recording or reproduction, or another surface. For example, FIG.
In the case of the above-mentioned write-once type optical information medium shown in FIG. 1, the dye recording layer 23 formed on the translucent substrate 21 and the reflective layer 24 formed thereon enable information recording and reproduction. I do. On the other hand, in a read-only optical information medium such as a CD in which a light reflecting layer and a protective layer are sequentially laminated on a substrate, information is reproduced by a pit row formed on the light transmitting substrate 21 and a reflective layer covering the pit row. I do.

The method of recording and reproduction is optical, and is generally a method using laser light, a magneto-optical recording / reproduction method, or the like. Recording and reproduction of such information are performed from one side of the optical information medium, and specifically, are performed by means such as making laser light incident from the front side of the light transmitting substrate 21. No optical information is recorded or reproduced from the other surface side. When laser light is used as recording light and reproduction light, a wavelength of 770
A wavelength of about 830 nm is generally used, but laser light having a wavelength other than this may be used.

Further, in addition to the dye recording layer 23 and the reflection layer 24 shown in FIG. 2 , another layer may be provided. For example,
In some cases, a layer or the like for improving reliability other than recording information may be provided, such as a layer for improving binding. In FIG. 2, the dye recording layer 23 is directly applied on the light-transmitting substrate 21, but another layer may be provided between them.

The protective layer 25 is a layer for protecting the information recording portion against a physical or mechanical obstacle received from the side opposite to the light transmitting substrate 21, and is provided on the side opposite to the light transmitting substrate 21 side. Such a protective layer 25 is desirably a resin having excellent impact resistance. The thickness of the protective layer 25 is preferably in the range of 5 to 10 microns, and it may be composed of a plurality of layers made of different materials.

In general, the protective layer 25 can be obtained by applying a monomer and oligomer of an organic compound which can be polymerized into a polymer and then subjecting it to a crosslinking reaction. When this is obtained as an organic polymer by a cross-linking reaction, from the viewpoint of workability, a mixture of a monomer and oligomer of an organic heavy compound having one or more reactive acryloyl groups (—CH ＝ CH 2) in the molecule, a reaction initiator, Add a small amount of the reaction catalyst, apply a mixture of these in a liquid state with a solvent such as methyl ethyl ketone or alcohol, and irradiate with ultraviolet light.
To crosslink. Since an adverse effect on the substrate and the information layer when the protective layer 25 is formed can be prevented and the protective layer 25 can be formed in a short time, an ultraviolet curable resin is used .

As such an ultraviolet curable resin, a known ultraviolet curable resin can be used as long as it is used for an optical information medium. Specifically, resins such as N-vinylpyrrolidone, tripropylene glycol diacrylate, trimethylolpropane triacrylate, and hexanediol diacrylate can be exemplified.

The main chain and side chain of the thus obtained crosslinked product may be a saturated or unsaturated linear hydrocarbon, or may contain a cyclic compound such as melamine or bisphenol. Also, a polyether containing one or more ether bonds in the middle or main chain of the crosslinked product,
Other bonds exemplified by polyesters containing ester bonds, polyurethanes containing urethane bonds, ionomers containing ionic bonds, polyamides containing amide bonds, polyimides containing imide bonds, polysulfones containing sulphone bonds, polysulfides containing sulfide bonds, etc. It may be included. A copolymer compound containing two or more of these bonds may be used, or a block polymer may be used.

In order to improve the moisture resistance of these crosslinked products, a fluorocarbon or the like may be contained in the side chain,
An epoxy resin may be included to prevent deterioration due to hydrogen halide. Protective layer 25 and hydrophilic resin film 26
In order to improve the adhesion with, a hydroxyl group, a carboxyl group, an acrylic group, an amino group, a vinyl acetate group or the like may be desirably included in the side chain of the crosslinked product.
The main chain or side chain may contain a chlorine group .

When the protective layer 25 is formed, a solvent and a diluent may be contained in the coating in addition to the resin, its reactant, the reaction initiator and the like in order to improve the coating property. Further, in order to stabilize the coating film, a leveling agent, a plasticizer, an antioxidant, an antistatic agent, and the like may be contained. If necessary, they may be colored with pigments or dyes.

The curing of the resin can be changed depending on the crosslink density of the crosslinked structure or the concentration of reactive acroyl, and also depends on the degree of freedom of molecular rotation of the oligomer itself which can be a main chain. If the shrinkage ratio during curing of the protective layer 25 is reduced, the protective layer 25 is less likely to crack even when a heat cycle test is performed after curing to prevent resin distortion. In consideration of mechanical strength, this shrinkage is preferably 12% or less, and more preferably 10% or less.

Note that an oxidation-resistant layer for preventing the light reflecting layer 24 from being oxidized may be interposed between the light reflecting layer 24 and the protective layer 25.

In the present invention, in such an optical information medium, a hydrophilic resin is formed on the protective layer 25 so that the printing ink can be fixed on the surface opposite to the side where the reading laser beam is incident.
A film 26 is formed, and its surface is used as a hydrophilic surface 27. With this hydrophilic surface 27, an aqueous ink is dropped,
The surface has sufficient hydrophilicity to fix the ink to such an extent that the ink does not bleed even if touched by hand after 30 minutes. That is, it is not a state in which the ink is simply attached by drying the ink, but a film to which the ink can be fixed to such an extent that the ink cannot be easily erased. The ink printed on the hydrophilic surface 27 is fixed to the hydrophilic surface 27 without reducing its adhesion area.

For example, as shown in FIG. 2, the surface of the protective layer 25 is coated with a hydrophilic resin, and a thin hydrophilic resin film 26 is formed. The ink for use can be fixed.
Examples of such a hydrophilic resin include, for example, polyethylene oxide (polyethylene oxide).
e), polyvinyl alcohol (polyvinyl a)
lcohol), polyvinyl methyl ether (poly)
vinylmethyl ether, polyvinyl formal, carboxyvinyl polymer (carboxyvinyl po)
lymer), hydroxyethyl cellulose (hydr)
oxyethyl cellulose, hydroxypropyl cellulose (hydroxypropyl c)
cellulase, methylcellulose (methyl)
cellulose), sodium carboxymethylcellulose (sodium carboxymeth)
ylcellulose, polyvinylpyrrolidone, morpholine, and the like. At least one kind of these hydrophilic resins is prepared, and if necessary, other additives are blended for coating.

These resins are mixed in a proper balance in consideration of the reliability and productivity of the optical information medium, such as weather resistance, water resistance, and warpage. 5% by weight of hydrophilic resin
As mentioned above, the solubility limit (for example, about 50% by weight) can be considered, but it is desirable to set the range of 5 to 20% by weight. If the amount is too large, the water resistance becomes poor, and the printing workability tends to deteriorate. If the amount is too small, the wettability of the ink is deteriorated, and fading after printing is liable to occur.

An additive may be separately added to the hydrophilic material. For example, it is also desirable to incorporate a water-absorbing pigment, a wetting agent, a defoaming agent, a surface tension adjusting agent, and the like. Specifically, inorganic pigments such as finely divided silica, fine powders such as carboxymethylcellulose, dextrin, and methylcellulose, polyvinylpyrrolidone and vinyl alcohol acrylate copolymer (Sumikagel SP-) made insoluble in amide acrylates and the like by a special coating. Organic pigments such as 510: manufactured by Sumitomo Chemical Co., Ltd .; known anionic or nonionic wetting agents (Nopco 2272RSN, Nopco Wet 50, Nopco Wet SN20T: all manufactured by San Nopco); Henkel), surface tension regulators (Perenol s43, s5: Henkel), and polyethyleneimine (SP103 Nippon Shokubai Co., Ltd.).

The water-absorbing pigment as an additive plays a role in adjusting the printability of the ink and the workability in forming a hydrophilic film. The wetting agent improves the wettability, adjusts the fluidity, can obtain a low foaming agent, and uses the same equipment as another layer forming step in the manufacturing process of the optical information medium such as screen printing. Can be formed,
Manufacturing efficiency can be improved. An antifoaming agent or a surface tension adjusting agent can form a coating film without unevenness.

By adding a pigment to the hydrophilic resin, the hydrophilic resin film 26 can be made opaque, turbid, or colored. This makes it possible to select an appropriate optical information medium according to the color of the ink and the degree of printing, thereby improving the appearance. In addition, it is also possible to form a relief pattern by forming a so-called nucleated portion by utilizing the color of a layer provided below the protective layer.

It is desirable that the hydrophilic resin film 26 does not contain water, ethyl alcohol, isopropyl alcohol, ethylene glycol, ethyl cellosolve, dimethylformamide and other solvents. The solvent may attack the lower protective layer and the ultraviolet curable resin, and reduce the reliability in some cases. Further, if a solvent is contained, the viscosity or the like when the hydrophilic resin film 26 is formed by means such as screen printing changes, which causes inconvenience in manufacturing.

The thickness of the hydrophilic resin film 26 is desirably in the range of 5 to 30 microns in order to prevent the recording / reproducing characteristics of the optical information medium from being affected. Such a film thickness can be obtained by appropriately blending the above materials and adjusting the viscosity and the like.

The hydrophilic resin film 26 is formed on the protective layer 25 made of an ultraviolet curable resin . In this case, immediately after forming the ultraviolet curable resin film as the protective layer 25, that is, while the activity before the ultraviolet curable resin serving as the base is completely cured is not impaired, the hydrophilic resin film 26 is formed. By forming, the layer boundaries can be integrated to improve the binding property.

The hydrophilic resin film 26 may be provided over the entire surface of the protective layer 25. For example, as shown in FIG. 1, the hydrophilic resin film 26 may be provided except for the inner and outer peripheral edges of the protective layer 25. The surface of the hydrophilic resin film 26 has a fine rough surface. When the printing ink adheres to the surface of the hydrophilic resin film 26 due to the fine surface condition, the printing ink is held and fixed in the fine concave portions, so-called anchoring. An effect is given. Also,
The rough surface increases the surface area of the hydrophilic resin film 26, and can promote ink absorption.

The term "rough surface" as used herein means a surface having a smaller contact angle with the aqueous ink than when the surface is not rough, and preferably has an average roughness (Ra) measured by a stylus type surface roughness measuring instrument.
Is preferably about 2.0 to 0.1 μm. The effect of this surface roughness on water-based inks varies slightly depending on the physical properties of the film.Generally, when the surface roughness is small, fine lines can be drawn with good resolution, but ink is formed solidly. If the surface roughness is too large, both fine lines and solids are likely to bleed. In particular, the average roughness (Ra) is set to 1.0 to 0.5 μm.
By setting it to about m, both fine line printing and solid printing can be printed practically well.

The fine rough surface of the hydrophilic resin film 26 can be formed by gravure coating a hydrophilic resin on the surface of the protective layer 25. For example, a filler is mixed on the surface of the protective layer 25. It can also be formed by coding a hydrophilic resin by screen printing or spin coating. For example, when an organic or inorganic pigment is dispersed as a filler in the hydrophilic resin film 26, a rough surface can be easily formed, and the anchoring effect is large. The particle size of the pigment is 1 to 10
A thickness of about μm is appropriate, and especially when the size is 3 to 5 μm, solid printability is improved. Also, the surface of the hydrophilic resin film
The fine and rough surface is formed on the protective layer 25 by the hydrophilic resin film 26.
After forming the surface, the surface of the hydrophilic resin film 26 is roughened.
Can also be formed.

The surface of the hydrophilic resin film 26 can be modified by plasma treatment to further enhance the hydrophilicity of the hydrophilic surface 27. Specifically, the optical information medium is placed in a dilute inert gas atmosphere in a vacuum state, and plasma is generated in this gas for processing. With such treatment, the surface tension of the ink attached to the treated surface is small, the contact angle of the ink is small, and the so-called ink wettability is improved. It is desirable to print the ink on this surface as soon as possible after the plasma treatment. The ink applicable to the optical information medium of the present invention is preferably an aqueous ink, but may be an oil-based ink or an ultraviolet-curable ink.

As described above, when characters and the like are printed on the hydrophilic surface 27, writing, screen printing, and the like can be used, but printing with an ink jet printer is particularly preferable. As is well known, an ink jet printer is used as a printer of a personal computer or the like, and is capable of repeatedly printing printed characters and printed patterns created by a computer on the hydrophilic surface 27. Therefore, it is suitable for printing certain characters and designs on a relatively small number of optical information media. In addition, since there is no need to apply an impact such as an impact at the time of printing or heat for fixing the printing ink, the optical information medium is not damaged. Similarly, it goes without saying that the present invention can also be applied to a so-called bubble jet method in which ink particles are formed and printed by a bubble jet method in which a nozzle portion is heated by a heater.

Next, specific examples of the present invention will be described.
A guide groove having a width of 0.8 μm, a depth of 0.08 μm, and a track pitch of 1.6 μm has a diameter of 46 to 117 mm in order to spirally guide tracking by a stamper.
120mmφ outer diameter, 15mm inner diameter formed in the range of
Prepare a polycarbonate substrate having a diameter of 1.2 mm and a thickness of 1.2 mm.

0.65 g of 1,1, -dibutyl 3,3,
3,3, tetramethyl 4,5,4,5, -dibenzoindodicarbocyanine perchlorate is dissolved in 10 ml of diacetone alcohol, and the solution is formed on the above substrate to an average film thickness of 130 nm while appropriately changing the rotation speed. The dye recording layer was formed by spin coating and drying. On this, gold was sputtered to form a reflective layer having a thickness of 100 nm.

Next, an ultraviolet curable resin mainly composed of acrylic (SD-17: manufactured by Dainippon Ink) is applied by spin coating, and irradiated with a high-pressure mercury lamp at 230 mj / cm 2 to emit a protective layer having a thickness of 10 μm. Was formed.

Further, 10% by weight of polyvinylpyrrolidone and 5% of polyvinylbutyral were prepared using ethanol as a solvent.
After mixing and dissolving sufficiently by mixing, 5% by weight of synthetic amorphous finely divided silica having a particle size of about 4 μm was mixed into the liquid, and these were mixed in a ball mill containing 12 balls of 21 pots. Dispersed over time to prepare a hydrophilic resin solution having a concentration of 40%.

Immediately after forming the protective layer, the protective layer was formed.
The activity of the UV curable resin before it is completely cured
While the state was not changed, the hydrophilic resin solution was applied on the protective layer by screen printing and dried at a temperature of 50 ° C. for 1 hour to form a hydrophilic resin film having a thickness of 10 μm. Thus, an optical information medium having a hydrophilic resin film was obtained. Also, 10% by weight of polyvinyl alcohol and 10% by weight of
% By weight, and after sufficiently dissolving and mixing, an optical information medium having a hydrophilic resin film was obtained in the same manner as described above except that 5% by weight of synthetic amorphous finely divided silica having a particle size of about 4 μm was added to the liquid. Was.

The surface state of the hydrophilic resin film thus formed is a semi-transparent rough surface, and its surface roughness (Ra)
Was measured with a stylus-type surface roughness meter (DEKTAK3030: manufactured by Becoin Instruments Inc.).
0.9 to 0.6 μm. The optical information medium obtained in this manner is irradiated with a semiconductor laser having a wavelength of 780 nm modulated into an EFM signal along a guide groove at a power of 7.8 mW and a linear velocity of 1.4 m / sec. Optical information was recorded.

Thereafter, a temperature of 70 ° C. and a humidity of 0% RH (DR
Y) The accelerated deterioration test was performed, and the ink jet printing performance (IJP performance) before and after the test was examined. In other words, whether an ink-jet printer prints “●” or “■”, prints solid without printing in a mesh pattern, prints kanji with many strokes, and prints without breaking the space between lines. The kanji printability was examined. Table 1 shows the results.

[0059]

[Table 1]

Further, the same optical information medium as in Example 2 was prepared, and after the hydrophilic resin film 26 was formed, a plasma treatment was performed using argon gas in an environment of 0.1 to 1 ton. IJP similar to the above
When the performance was examined, good printing performance was obtained in each case.

Table 2 shows the warp angle of the optical information medium in that case. Table 2 also shows the warp angle after leaving for 98 hours at a standard time of a temperature of 23 ° C. and a humidity of 50% RH. The warp angle was measured in a radial direction at a position having a radius of 55 mm from the center according to the CD standard, and the average value was shown. The comparative example has a protective layer having a thickness of 25 μm and does not have a hydrophilic resin film. In each case, the angle is 0.6 ° or less specified by the CD standard.

[0062]

[Table 2] 角 Warp angle (°) Initial 100 hours later Standard condition (98 hours) ──── ─────────────────────── Example 1 0.05 0.18 0.13 Example 2 0.02 0.17 0.15 Comparative Example 0 .02 0.17 0.15 ───────────────────────────

Further, printing for the IJP test as described above was performed on the surface of the hydrophilic resin film of the optical information medium with an ink jet printer, and the printing was performed at a temperature of 70 ° C. and a humidity of 85% RH and a temperature of 70 ° C. for 8 hours. A 100-hour accelerated deterioration test was performed under the condition of 0% RH (DRY), and blurring or blurring of the print was confirmed. As a result, almost no blurring or blurring was observed. After printing on the surface of the hydrophilic resin film, the printed surface was rubbed by hand three minutes after printing, but no blurring or the like occurred. In order to compare the binding property between the protective layer and the hydrophilic resin film, a peeling test (cross-cut test) was performed. It was 100/100 in the film part.

[0064]

As described above, according to the optical information medium of the present invention, certain characters and patterns are easily and satisfactorily written on the surface of the protective layer of the optical information medium using ordinary aqueous ink or oil-based ink. be able to. In addition, it is possible to provide an optical information medium that has an excellent protection function for the optical information medium and also has excellent weather resistance . Further, according to the method of the present invention, it is possible to provide a method for printing on a surface of an optical information medium that can easily print certain characters and designs with a substantially constant quality on a relatively small number of optical information media. be able to.

[Brief description of the drawings]

FIG. 1 is an external perspective view of an optical information medium.

FIG. 2 is a schematic longitudinal sectional view of a main part of an optical information medium showing an embodiment of the present invention.

FIG. 3 is an exploded perspective view of a holder and an optical information medium used when printing on the surface of the optical information medium using an ink jet printer.

FIG. 4 is a schematic sectional view of a main part showing an ink jet printer used in an embodiment of the present invention.

[Explanation of symbols]

2 Optical Information Medium 4 Clamp Hole 21 Translucent Substrate 22 Guide Groove 23 Dye Recording Layer 24 Reflective Layer 25 Protective Layer 26 Hydrophilic Resin Film 27 Hydrophilic Surface

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Toshio Watanabe 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (56) References JP-A-64-43826 (JP, A) JP-A Sho 61-10843 (JP, A) JP-A-61-217280 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 7/24

Claims (10)

(57) [Claims] A protective layer made of a resin is formed on a plate-shaped light-transmitting substrate and adhered directly or via another layer, so that information optically readable by laser light can be reproduced and / or reproduced. Alternatively, in a recordable optical information medium, an ultraviolet-curable resin is provided on the back side of the light-transmitting substrate on the side where the reproduction light is incident.
A protective layer made of a fat is formed, and a hydrophilic resin film capable of fixing an aqueous printing ink on the surface is formed on the protective layer.
It is formed in a bound state where the layer boundary with the protective layer is integrated.
The optical information medium is characterized in that the surface of the hydrophilic resin film is a fine rough surface . 2. A method according to claim 1, further comprising: providing a protective layer made of a resin adhered directly or through another layer on the plate-shaped light-transmitting substrate, and reproducing and / or reproducing information optically readable by a laser beam. Alternatively, in a recordable optical information medium, an ultraviolet-curable resin is provided on the back side of the light-transmitting substrate on the side where the reproduction light is incident.
A protective layer made of a fat is formed, and a hydrophilic resin film capable of fixing an aqueous printing ink on the surface is formed on the protective layer.
It is formed in a bound state where the layer boundary with the protective layer is integrated.
The optical information medium is characterized in that the surface of the hydrophilic resin film is a fine rough surface, and the aqueous ink is fixed on the surface of the hydrophilic resin film to perform display. 3. The optical information medium according to claim 1, wherein the ultraviolet curable resin forming the protective layer comprises a hydroxyl group, a carboxyl group, an acrylic group, an amino group or a vinyl acetate group on a side chain of the crosslinked product. Or a chlorine- containing group in the main chain or side chain of the crosslinked product. 4. The optical information medium according to claim 3, wherein the resin forming the hydrophilic resin film is polyethylene oxide, polyvinyl alcohol, polyvinyl methyl ether, polyvinyl formal, carboxyvinyl polymer, hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose. An optical information medium, which is a resin containing at least one of carboxymethylcellulose sodium salt, polyvinylpyrrolidone and morpholine. 5. The optical information medium according to claim 1, wherein the surface of the hydrophilic resin film has an average roughness Ra of 2.
An optical information medium having a rough surface of 0 to 0.1 μm . 6. The optical information medium according to claim 1, wherein the fine rough surface of the hydrophilic resin film is formed by dispersing an organic or inorganic pigment in the hydrophilic resin film. An optical information medium characterized by being formed. 7. The one of the optical information medium of the claims 1-5, fine roughened surface of the hydrophilic resin film is formed by forming a hydrophilic resin film is subjected to roughening the surface thereof An optical information medium characterized by being formed by the above. 8. The optical information medium according to claim 1, wherein the surface of the hydrophilic resin film is modified to be hydrophilic. 9. A protection layer made of a resin formed on a plate-shaped light-transmitting substrate and adhered directly or via another layer to record and / or record information optically readable by laser light. Alternatively, in a method of printing on the surface of a recordable optical information medium, a protective layer made of an ultraviolet-curable resin is formed on the back side of the light-transmitting substrate on the side where the reproduction light is incident.
A hydrophilic resin film , on the surface of which a water-based printing ink can be fixed , is formed on the protective layer.
The surface of this hydrophilic resin film is
An optical information medium having a fine rough surface is prepared, and the hydrophilic resin is prepared.
A method for printing a surface of an optical information medium, comprising jetting aqueous ink toward the surface of a film, causing the ink to adhere to the surface, and fixing the aqueous ink to the surface. 10. The surface printing method for an optical information medium according to claim 9, wherein the aqueous ink is jetted toward a hydrophilic surface by an ink jet printer.