JPH10162438A - Optical recording medium and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form certain characters and patterns with sharp colors by forming a protective layer or a print accepting layer containing hydrophilic and water- insoluble particles and by controlling the Mohs' hardness, surface arithmetic average roughness and chromaticity of the surface to each specified range. SOLUTION: The optical recording medium consists of a transparent substrate and at least a light-absorbing layer, a light-reflecting layer and a protective layer and/or a print-accepting layer successively formed on the substrate. The protective layer or print accepting layer has such properties that (a) the layer contains particles which are hydrophilic and water-insoluble and have <=3 Mohs' hardness, (b) the arithmetic average roughness Ra of the layer is 0.3 to 2.0μm, and (c) the chromaticity of the surface in the Lab space is +5 to -5 for the b value. As for the material to form the light-absorbing layer, preferably an org. dye is used. For example, cyanine dyes, squarylium dyes, chloconium dyes, etc., are used. As for the light-reflecting layer, metals such as silver, platinum and aluminum are preferably used from the viewpoint of surface whiteness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording medium having good surface printability, high whiteness on the printed surface, and excellent color clarity.

[0002]

2. Description of the Related Art Optical recording media, commonly known as optical discs, have a larger recording capacity than conventional recording media and can be accessed randomly, so they are read-only media such as audio software, computer software, game software, and electronic publications. Widely used as. In recent years, write-once recordable optical disks having an organic recording layer or an inorganic recording layer based on various recording principles have been developed, and some of them have been put to practical use. One of them is a recordable compact disc (C
D-WO), which allows additional recording, and exhibits the same reflectance as a read-only compact disc, so that it can be reproduced by a read-only compact disc player or drive after recording.

[0003] Recently, this recordable compact disc has been widely distributed to individual users, and has been used for making self-made CDs by amateur musicians and making self-made CD-ROMs by computer users. It is used to record personal information in many other uses. When possessing, managing, or distributing an optical recording medium on which personal information is recorded, it is necessary to display an index of the recorded content and other designs on the surface of the disc. However, the protective layer, which is the outermost layer of recordable compact discs that have already been put into practical use and marketed, has nothing written, or common characters or patterns are printed with UV-curable ink or oil-based ink However, neither the surface of the protective layer nor the printed surface is suitable for displaying ink or the like on the surface, and the user must use a simple device such as an inkjet printer to print the index or the like later. It is difficult to print arbitrary information freely personally.

For this reason, a method of writing on the surface of the protective layer using an oil-based felt pen or the like is generally employed. But,
In this case, writing must be performed by hand one by one, which is troublesome, and there is a problem in that the drawn pattern and the drawing quality vary, and the appearance of the optical recording medium is spoiled. In addition, a method of attaching a label or the like has been proposed.However, the display surface rises by the thickness of the label, and it is easy to cause scratches or surface blurring of the optical recording medium during reproduction or additional recording. However, there is a problem that the disk is easily peeled off together with the label and the disk itself is easily damaged.

As a technique for solving the above-mentioned problems, a method of providing a printing layer made of a hydrophilic resin on the surface (Japanese Patent Laid-Open No. 6-60 / 1994).
No. 432), a method for improving the ink fixability by incorporating an organic or inorganic filler into the surface protective layer (Japanese Patent Laid-Open No.
-169700). On the other hand, in general, as the light reflecting layer, gold is used as a material having high reflectance with respect to laser light to be used for matching with a specific organic dye used for the light absorbing layer. According to the above method, although the fixing property of the ink is improved, the surface of the print receiving layer becomes gold, so that another problem arises in that the printed pattern, particularly the yellow portion, cannot be clearly seen.

In addition, in the method of containing an organic or inorganic filler, not only the color of the light reflecting layer but also the color of the filler makes the print unclear. As a method of improving the color of the printing surface, a method of providing a white pigment layer such as titanium white between the protective layer and the print receiving layer can be considered, but even if the white pigment layer is provided, the problem of color caused by the filler is The problem could not be solved, and the pigment layer was hard, so that the recording layer might be damaged when writing on the surface with a writing tool having a hard pen tip.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems and to provide an optical recording medium capable of easily and clearly forming certain characters and patterns on the surface of a protective layer or a printed layer. It is the purpose.

[0008]

According to the present invention, there is provided an optical recording medium comprising a transparent substrate, on which at least a light absorbing layer, a light reflecting layer, a protective layer and / or a print receiving layer are sequentially laminated. The receiving layer comprises: a) particles that are hydrophilic and water-insoluble and have a Mohs hardness of 3 or less; b) have an arithmetic mean roughness Ra of the surface of 0.3 to 2.0 μm; c. ) When the chromaticity of the surface is in the Lab space, the b value is from +5 to-
5. An optical recording medium and a method for manufacturing the same.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The optical recording medium of the present invention will be described below in detail. As the transparent substrate used in the present invention,
Any material may be used as long as it is transparent to light used for writing and reading information, and examples thereof include plastic such as polycarbonate, polymethyl methacrylate, and amorphous polyolefin, and glass, but are not limited thereto. A spiral guide groove or a tracking guide having another shape may be provided on the surface of such a transparent substrate.

As a material for forming the light absorbing layer, an organic dye is preferably used. For example, cyanine dyes,
Squarylium dye, croconium dye, azurenium dye, triarylamine dye, anthraquinone dye, metal-containing azo dye, dithiol metal complex salt dye, indoaniline metal complex dye, phthalocyanine dye, naphthalocyanine dye, intermolecular A type charge transfer dye or the like is preferably used. These dyes may be used alone or as a mixture, and if necessary, a deterioration inhibitor,
You may use it in the form which added the binder etc. As a method for forming the light absorbing layer containing such an organic dye, a method in which an organic dye or the like is dissolved in an organic solvent and spin-coated on the transparent substrate is preferably used, but a sublimation method such as a phthalocyanine dye is preferably used. For a dye having the following formula, a vapor deposition method can also be used.

As the light absorbing layer, a phase change type using an inorganic thin film such as a chalcogenide alloy thin film such as GeSbTe or TeSe, and a magneto-optical recording using a rare earth-transition metal alloy thin film such as TbFeCo or the like. A type or the like can also be used. The thickness of the light absorbing layer is usually 10
It is preferable that the thickness be about 5 nm to 5 μm, preferably about 70 nm to 3 μm.

The light reflecting layer is formed of a material having a high reflectance with respect to a laser beam to be used, and is preferably made of a metal such as silver, platinum or aluminum or an alloy thereof from the viewpoint of surface whiteness. . The use of silver, platinum, or aluminum is preferable because the whiteness of the surface of the print receiving layer is increased, and the printed characters and pictures are clearly seen. further,
Silver or silver-based alloys are most preferred in terms of high reflectivity, weather resistance and cost. Examples of the silver alloy include an alloy containing 10% or less of copper, gold, and a platinum group metal in silver. The light reflection layer is formed by a sputtering method, a vacuum evaporation method, or the like, and is preferably formed as a thin film having a thickness of 50 to 150 nm.

A dielectric layer or an organic polymer layer may be provided between the substrate, the light absorbing layer and the light reflecting layer, if necessary. The protective layer is usually provided by applying a cross-linking reaction after applying a monomer and a polymer of an organic compound which can be polymerized into a polymer. The material is preferably an ultraviolet curable resin, but is not necessarily limited thereto, and may be crosslinked by heat, moisture in the air, or other factors. If necessary, additives such as a deterioration inhibitor, a diluent, and a plasticizer may be contained. The material of the protective layer is not limited to an organic compound, and a known means such as a sputtering method or a vapor deposition method other than coating can be applied as a forming means. Such a protective layer may be composed of a plurality of layers made of different materials.
Further, the protective layer may also serve as a print receiving layer as described later.

The print-receiving layer or the protective layer serving also as the print-receiving layer (hereinafter referred to as the print-receiving layer together) is a hydrophilic and water-insoluble particle having a Mohs hardness of 3 or less. contains. The print receiving layer containing such hydrophilic particles is particularly effective for improving the fixability of the aqueous ink. That is, the drying of the aqueous ink is accelerated, and the water resistance of the printed ink is improved. This is because the water contained in the aqueous ink is absorbed by the hydrophilic particles.

In the present invention, hydrophilicity is a property capable of absorbing moisture, and is not restricted by functional groups on the particle surface. Further, in order to suppress bleeding of the ink and to make the medium water-resistant, the particles need to be water-insoluble. Specifically, it is preferable that the weight loss when extracted with water at normal temperature for 10 minutes is 5% by weight or less.

The particles must have a Mohs hardness of 3 or less. If the Mohs hardness exceeds 3, when writing on the surface, the writing pressure may affect the reflective layer and the recording layer, which may cause an error during recording and reproduction. Since the particles having a Mohs hardness of 3 or less have a moderate softness, the print receiving layer containing the particles absorbs the impact due to the pen pressure,
Has little effect on the lower layer.

Examples of the particles having the above-mentioned properties include protein, lignin, and cellulose particles. These components need not be isolated, and specifically, lignin-cellulose particles obtained by crushing bark, protein particles obtained by crushing animal leather, cellulose particles obtained by crushing cotton yarn And protein particles obtained by pulverizing silk thread.

Of these particles, those other than white are:
It is necessary to adjust the chromaticity of the surface of the optical recording medium by adding a complementary color pigment. Particularly preferred as such particles are particles obtained by pulverizing a silk thread into fine particles. Especially when the silk is 98% or more, the specific gravity is 1.3 to 1.
4, those having a bulk specific gravity of 0.2 to 0.4 are preferable.

When the fine powder of silk thread is used, not only the fixing property of the ink is improved but also the effect of increasing the whiteness of the surface, that is, the effect of making the a value and b value of the Lab color space close to 0 is simultaneously achieved. it can. Further, in order to improve the adhesion of the ink and to prevent the recording layer from being affected by printing, it is preferable that the particles have a particle size of 100 μm or less and have a uniform particle size. More preferably, the average particle size is 30μ.
m or less.

The particle size can be measured visually with an optical microscope. Further, as a simple method, the particle size can be uniformed by using a sieve having an appropriate size, or by filtering the filter with an appropriate size into a slurry. Further, the particles preferably comprise 10 to 70% by weight of the print receiving layer. If it is 10% or less, the effect of containing the silk protein particles cannot be obtained, and if it is 70% or more, the resin cannot fully hold the particles, and the particles will fall off. Most preferred is in the range of 25-55% by weight.

The print receiving layer has an arithmetic average particle size R on the surface.
a is 0.3 to 2.0 μm. Since a surface having a relatively large surface roughness has a larger surface area than a smooth surface having a very small surface roughness, printing is easier on a surface having good printability. Conversely, if the roughness is too large, the area of contact with the ink will be small, resulting in blurring. Therefore, the surface roughness is 0.3 to 2.0 μm.

Further, the chromaticity of the surface of the print receiving layer is La.
The b value is -5 to +5 in the b space. In this case, when the display is performed by a conventional method, the desired color effect is exhibited without being impaired. In the Lab color space, the b value represents the intensity of yellow (+) to blue (-). Especially the b value is -5 to +
If the value is out of the range, the ground color on the surface of the protective layer becomes too strong for these specific colors, and the original color effect cannot be obtained when performing multicolor printing.

As described above, when the reflective layer is made of a material having no specific color tone, for example, a metal or an alloy containing 50% or more of silver is more effective. In addition, it is preferable that the protective layer be opaque to light because it is less likely to be affected by the color tone of the lower layer such as the reflective layer. When particles are contained in the print receiving layer, light becomes difficult to transmit due to the difference in the refractive index between the resin and the particles, and light is irregularly reflected due to the roughened surface, thereby increasing opacity. preferable.

Further, in order to cancel the color tone of the reflective layer, a coloring substance such as a dye or an ion may be added to give a complementary color. The formation of the print receiving layer may be performed by applying an ultraviolet curable resin containing the above-described particles and then curing the resin, or by dissolving the resin and the particles in a solvent and drying after applying the resin. Various additives may be added to the print receiving layer according to the purpose. For example, a photopolymerization initiator, a surfactant, an ultraviolet absorber, a wetting agent, an antifoaming agent, a surface tension modifier, and the like may be included.

Among the particles to be contained in the print receiving layer, since silk is preferred as an animal protein, the benzimidazole compound, thiophenate methyl compound, dioxoimidazolidine is added to the protective layer or the print receiving layer. It is preferable to include a fungicide such as a series compound or an isothiazolone series compound. Specifically, as a fungicide, the following general formula [I]

[0026]

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(Wherein, R ¹ represents an optionally substituted C ₁ -C ₄ alkyl group, and R ² represents a C ₁ -C ₄ linear or branched alkyl group.) A benzimidazole compound represented by the following general formula [II]:

[0028]

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(Wherein R ³ and R ⁴ represent a C ₁ -C ₄ linear or branched alkyl group) or a thiophenate compound represented by the following general formula [III
]

[0030]

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(Wherein R ⁵ represents a C ₁ -C ₄ linear or branched alkyl group) or a dioxoimidazolidine compound represented by the following general formula [IV]:

[0032]

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(Where R⁶Is a hydrogen atom, is substituted
Good C₁~ C₁₈An alkyl group of which may be substituted
Alkenyl group, optionally substituted cycloalkyl
Group, an optionally substituted aryl group,
Polycyclic carbocycles, optionally substituted heteroaromatics
Ring, optionally substituted sulfonylaminocarboni
And R represents⁷Is hydrogen, halogen, cyano
Group, linear or branched C ₁~ C_FourRepresents an alkyl group of
Then R⁸Represents a hydrogen atom, a halogen atom,
Good alkylthio group, optionally substituted heterocyclic group
O group, an optionally substituted arylthio group,
An alkylcarbonyl group which may be substituted
A good arylcarbonyl group, an optionally substituted al
Coxycarbonyl group, arylo which may be substituted
Indicates a xycarbonyl group. R⁷, R⁸Is cyclized to 5-7
It may represent a membered carbocycle. n represents an integer of 0 to 2
You. Examples include the isothiazolone compounds represented by)
Can be used alone or in combination.
Can be.

In the benzimidazole compound represented by the above general formula [I], examples of the optionally substituted C ₁ -C ₄ alkyl group represented by R ¹ include methyl, ethyl, propyl, n -Butyl group, which may be substituted with a cyano group, a methylthio group, a methoxy group, a halogen atom, or the like. Among these alkyl groups, an n-butyl group is particularly preferably used. In the general formulas [I], [II] and [III], R ² , R ³ and R ⁴
And R ⁵ are methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl,
sec- butyl group, t-linear or branched alkyl group like C ₁ -C _4, such as a butyl group, especially a methyl group in this is preferably used.

An isothiazolone compound represented by the above general formula [IV]
In the object, R⁶A hydrogen atom; a methyl group, an ethyl
Group, n-propyl group, i-propyl group, n-butyl
Group, sec-butyl group, tert-butyl group, -C_FiveH
₁₁(N), -C₆H₁₃(N), -C₇H_Fifteen(N), -C
₈H₁₇(N), -C_TenH_{twenty one}(N), -C₁₂H_{twenty five}(N),
-C_TwoH_FourOCH_Three, -C_TwoH_FourOC_TwoH_Five, -C_TwoH
_FourCOCH_Three, -CH_TwoCH_TwoCH_TwoCOCH_Three, -C
_TwoH_FourCOC_TwoH_Five, -C_TwoH_FourOCOCH_Three, -C_Two
H_FourOCOC_TwoH_Five, -C_TwoH_FourCOOCH_Three, -C_Two
H_FourCOOC_TwoH _Five,

[0036]

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An optionally substituted C ₁ -C ₁₈ alkyl group;

[0038]

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An optionally substituted alkenyl group such as

[0040]

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An optionally substituted cycloalkyl group such as

[0042]

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An optionally substituted aryl group such as

[0044]

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An optionally substituted polycyclic carbocycle;

[0046]

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A heteroaromatic ring which may be substituted;

[0048]

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Optionally substituted sulfonyluas
An example is a minocarbonyl group. R⁷As a hydrogen source
Child; fluorine atom, chlorine atom, bromine atom, iodine atom
Rogen atom; cyano group; methyl group, ethyl group, n-pro
Pill group, i-propyl group, n-butyl group, sec-butyl
Linear or branched C such as
₁~ C_FourCan be exemplified. R⁸As the water
Elemental atom; fluorine atom, chlorine atom, bromine atom, iodine atom
Halogen atom of methylthio group, ethylthio group, methoxy
Cimethylthio, benzylthio, phenethylthio, etc.
An optionally substituted alkylthio group;

[0050]

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An optionally substituted arylthio group such as an acetyl group, a propionyl group, a methoxyethylcarbonyl group, a benzylcarbonyl group, a phenethylcarbonyl group, a hydroxyethylcarbonyl group and a cyanoethylcarbonyl group; Carbonyl group;

[0052]

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An optionally substituted arylcarbonyl group such as methoxycarbonyl group, ethoxycarbonyl group, methoxyethoxycarbonyl group, benzyloxycarbonyl group, phenethyloxycarbonyl group, etc .;

[0054]

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And an optionally substituted aryloxycarbonyl group. And R ⁷ and R ⁸ are cyclized,

[0056]

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And a 5- to 7-membered carbon ring such as The amount of the fungicide added to the protective layer or the print receiving layer is usually 0.01 w
t% or more, preferably 0.02 to 0.06 wt%. The minimum inhibitory concentration (MIC) of these compounds against mold is about 5 to 20 ppm, but larger amounts need to be added to the protective layer or print receiving layer.

If the amount is too small, the ability of the mold to inhibit the growth of mycelium is reduced. If the amount is too large, it will not dissolve in the resin forming the protective layer or the print receiving layer, so that the localized fungicide affects various properties of the optical recording medium, and neither is preferable. In addition, when the compound group is added to the surface of the protective layer or the print receiving layer, a smaller amount of the same antifungal effect can be obtained as compared with the case where the compound group is added to the inside of the protective layer or the print receiving layer. Obtainable.

Between the protective layer and the print receiving layer, an intermediate layer such as a second protective layer, an adhesive layer, a dye diffusion preventing layer, and an elastic layer may be provided if necessary. Further, the print receiving layer as in the present invention may be provided on the entire surface or partially. The thickness of the print receiving layer is determined in consideration of printability, function as a protective film, ease of production and cost, and is preferably about 4 to 20 μm, more preferably about 5 to 15 μm.

Hereinafter, an example of forming a print receiving layer using an ultraviolet curable resin will be described. After applying a mixture of the following components, a) a resin oligomer component containing an acrylic acrylate oligomer, b) a resin monomer component, c) particles obtained by pulverizing and pulverizing a silk thread, d) a photopolymerization initiator. Then, a print receiving layer is obtained. At this time, a print receiving layer having various characteristics can be obtained by selecting various resin oligomers and resin monomers.

Depending on the type and amount of the resin oligomer, hardness,
Changes in adhesion, water resistance, moisture resistance, etc. Further, the viscosity, hardness, and the like change depending on the type and amount of the resin monomer.
Various resin oligomers can be used together with the acrylic acrylate.

Examples of the urethane oligomer include a reaction product of a polyurethane composed of hexamethylene diisocyanate and 1,6-hexanediol and 2-hydroxyethyl acrylate, and a polyester diol composed of adipic acid and 1,6-hexanediol and tolylenediene. 2 to diisocyanate oligomer reacted with isocyanate
-Hydroxyethyl acrylate and the like.

Examples of the ester oligomer include an ester of acrylic acid and a polyester diol composed of a ring-opening polymer of phthalic anhydride and propylene oxide, and a polyester diol composed of adipic acid and 1,6-hexanediol and acrylic acid. Examples include esters, esters of acrylic acid and triols formed from a reaction product of trimellitic acid and diethylene glycol, and esters of acrylic acid with a ring-opening polymer of δ-valerolactone. As the ether-based oligomer, an ester of polypropylene glycol and acrylic acid can be used.
As the resin monomer and the photopolymerization initiator, any known ones used for ultraviolet curable resins can be used.

Specifically, as the resin monomer, tetrahydrofurfuryl acrylate (ether monomer), 1,6-hexanediol diacrylate, neopentyl glycol diacrylate (aliphatic chain monomer), tricyclodecane acrylate ( Aliphatic cyclic monomers), hydroxypropyl acrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, and the like. Examples of the photopolymerization initiator include benzoin isopropyl ether, benzophenone, 2-hydroxy-2
-Methylpropiophenone, 1-hydroxycyclohexyl phenyl ketone, 2,4-diethylthioxanthone and the like.

The ink used for the optical recording medium of the present invention may be any ink such as water-based ink, oil-based ink, and ultraviolet-curable ink. Examples of the aqueous ink include an anionic ink, a cationic ink, and a nonionic ink. When characters or the like are printed on the print receiving layer, writing, screen printing, or the like can be used, but printing is particularly preferably performed using an inkjet printer. As is well known, inkjet printers can repeatedly print printed characters and printed patterns created by computers,
It is suitable for printing certain characters and designs on optical recording media. In addition, since there is no need to apply mechanical shock such as impact or heat for fixing the printing ink during printing, the optical recording medium is not damaged. Similarly, the present invention can be applied to a bubble jet method in which ink particles are formed and printed by a bubble jet method in which a nozzle portion is heated with a heater. Also, printing can be performed favorably with a heat-sensitive fusion transfer printer.

[0066]

The present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention. Example 1 As a transparent substrate, a polycarbonate substrate having a diameter of 120 mm and a thickness of 1.2 mm provided with a periodically meandering tracking groove for a recordable compact disc was used. The light-absorbing layer was formed by dissolving a metal-containing azo dye at a concentration of 2.4% by weight in methyl cellosolve, filtering the solution, and then forming a film on the substrate by spin coating. After dye application,
Drying was performed in an oven at 100 ° C. for 20 minutes in order to completely evaporate the solvent in the dye layer.

Next, as a light reflecting layer on the light absorbing layer,
A silver film having an average thickness of 80 nm was formed by DC magnetron sputtering in an argon gun. Further, an ultraviolet curing agent SD-318 (manufactured by Dainippon Ink and Chemicals, Inc.) is applied on the light reflecting layer in a thickness of 5 μm by spin coating, and is cured by irradiating ultraviolet rays with an ultraviolet irradiating device to protect. A layer was formed.

A coating liquid having the composition shown in Example 1 of Table 1 was applied thereon by screen printing, and irradiated with an ultraviolet ray having an intensity of 240 mJ / cm ² by an ultraviolet irradiation apparatus to form a print receiving layer. did. The hydrophilic particles used were obtained by pulverizing and pulverizing silk yarn, and had an average particle size of 5 μm (made by Idemitsu Petrochemical Co., Ltd.). When the particles were extracted with water at normal temperature for 10 minutes, the weight loss was 5% by weight or less. The thickness of the print receiving layer was 10 μm.

The surface roughness (Ra) of the obtained optical recording medium was 1.20 μm, and the optical recording medium was measured using a colorimetric colorimeter ND-1001DP (manufactured by Nippon Denshoku Industries Co., Ltd.). When the chromaticity was measured, the color difference Lab value was found to be L value 7
7.2, a value -5.8, and b value 2.7. Next, when color printing was performed using a valve jet type or piezo type CD-ROM printer, the printability was excellent, such as little color bleeding. Was also excellent.

In the storability test under high humidity (25 ° C., 85% RH), color bleeding was extremely small, and the storability of the color print image of the ink jet system was excellent. on the other hand,
"Per-perfusion" CD-ROM printer
Fact Image CD-R Printer "
As a result of printing a monochrome image (manufactured by Rimage), a sharp image / text print was obtained with very little color fading.

A full-color image was formed on the surface of the obtained optical disk by inkjet recording using the following two types of recording liquids, and the characteristics of the recorded image were evaluated. Inkjet printers are expert jet nematics CDs as bubble jet printers.
-A ROM printer CP-1000 was used, and a CD-ROM printer ORP-C800 manufactured by Orient Sokki Computer was used as a piezo-type printer.

Table 1 shows the evaluation results of the obtained images.
Shown in The evaluation of the characteristics of the recorded image was performed based on the following criteria. 1) Regarding printability, the sharpness (color bleeding) of the obtained images was visually compared and ranked according to the following criteria. ◎: Very clear. ：: Clear. Δ: Almost clear. ×: The image is slightly blurred or repelled, or the image is faint.

2) Regarding the drying property of the ink, the degree of transferability of the ink when a recycled paper was applied to the image 5 minutes after printing was ranked according to the following criteria. A: Almost no stain on the recycled paper is observed. Δ: Stain on recycled paper observed. X: Stain on the recycled paper is severely seen.

3) The color clarity was evaluated by visually comparing the color clarity of the yellow color, which is easily affected by the background, in the color image, and ranked according to the following criteria. ◎: Yellow color part can be very distinguished. ：: Yellow color portion can be identified. Δ: Yellow color portion is difficult to recognize. X: Yellow color part cannot be identified.

Examples 2 to 10 Examples 7 to 9 in Table 1
Example 1 was prepared by using the coating solution for the print receiving layer having the composition shown in
A disk was prepared in the same manner as described above, and a test was performed in the same manner. The results are shown in Table-2. As in Example 1, the color clarity of the ink jet type color prints was excellent, and the image storability at high temperatures was good. Further, a sharp character / image printed matter of a heat-sensitive melting system was obtained.

In Examples 2 to 6 and 10 in Table 1,
A disk was prepared in the same manner as in Example 1 using a coating solution for a print receiving layer containing a fungicide having the composition shown below, and the same test was conducted. The results are shown in Table 2. In the same manner as in Example 1, the color clarity of the ink jet type color print was excellent, and the image storability under high humidity was good. Further, a sharp character / image printed matter of a heat-sensitive melting system was obtained.
On the other hand, when the antifungal test was performed, all the results were + ~
The growth inhibitory effect on the fungal hyphae was confirmed by the addition of a fungicide. Structure of fungicide Example 2 Compound (A)

[0077]

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Example 3 Compound (B)

[0079]

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Example 4 Compound (C)

[0081]

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Example 5 Compound (D)

[0083]

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Example 6 Compound (E)

[0085]

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Example 10 Compound (F)

[0087]

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<Test method for fungicide resistance> First, a plate of potato dextrose agar medium (Nissui) was prepared, and the recordable compact disc prepared above was placed in a size of 20 × 2.
It was cut to 0 mm and placed on the medium. Airborne bacterial species selected from the molds used in the standard fungicide test (Table 3)
) Were inoculated on sheets and medium. Thereafter, the print-receiving layer was cultured at a temperature of 30 ° C. for 10 days, and the fungicide resistance of the print receiving layer was examined. The antifungal property was determined by observing the invasion of the mold from the culture medium into the sheet by a stereoscopic microscope and according to the following evaluation criteria.

The results showed that all of the fungicide additives were at + to-level, and the addition of the fungicide confirmed the growth inhibitory effect on the fungal mycelium. Evaluation criteria +++ Spores are formed on the sheet. ++ Medium hypha growth on sheet. + Poor hyphal growth on sheet. -No hypha growth.

Comparative Example 1 A disk was prepared in the same manner as in Example 1 except that the light reflecting layer was an Au film, and a test was conducted in the same manner. The results are shown in Table 1. Under the influence of the gold color of the Au reflection layer, it was particularly inferior in yellow and color clarity. [Comparative Examples 2 to 4] Discs were prepared in the same manner as in Example 1 by using the coating liquids for the printing receiving layers having the compositions shown in Comparative Examples 2 to 4 in Table 1, and tests were performed in the same manner. The results are shown in Table 1. In Comparative Examples 2 and 3, it was confirmed that the color bleeding property was inferior in the ink jet method and the drying property of the ink was at a slightly slower level. In Comparative Example 4, a result was obtained in which printing could not be performed at all by the inkjet method.

[0091]

[Table 1]

[0092]

[Table 2]

[0093]

[Table 3]

[0094]

[Table 4]

[0095]

According to the present invention, the surface of the optical recording medium is
Arithmetic mean roughness Ra is in the range of 0.3 to 2.0 μm,
Moreover, since the a-value and b-value are in the range of -5 to +5 in the Lab color space, they have excellent surface printability and do not have a specific color tone, so even if various colors are displayed on this surface, Its color effect is not impaired.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI A01N 47/38 A01N 47/38 B

Claims (14)

[Claims] 1. An optical recording medium comprising a transparent substrate on which at least a light absorbing layer, a light reflecting layer, a protective layer and / or a print receiving layer are successively laminated, wherein the protective layer or the print receiving layer is a) hydrophilic. And water-insoluble particles having a Moh's hardness of 3 or less, b) the arithmetic mean roughness Ra of the surface is 0.3 to 2.0 μm, and c) the chromaticity of the surface in Lab space: b value is +5-
5. An optical recording medium according to item 5, wherein 2. The hydrophilic and water-insoluble particles as described above, wherein the maximum particle size is 100 μm or less, and the content of the particles is 10 to 70% by weight of the protective layer or the print receiving layer. Item 2. The optical recording medium according to Item 1. 3. The optical recording medium according to claim 1, wherein the hydrophilic and water-insoluble particles are obtained by pulverizing a silk thread into fine particles. 4. The optical recording medium according to claim 1, wherein the light reflection layer is made of silver or an alloy mainly containing silver. 5. The optical recording medium according to claim 1, wherein the protective layer or the print receiving layer containing the hydrophilic and water-insoluble particles contains a fungicide. 6. The optical recording medium according to claim 5, wherein the fungicide is a benzimidazole compound represented by the following general formula [I]. Embedded image (Wherein, R ¹ has 1 to 4 carbon atoms which may have a substituent.
Alkyl group, R ² represents a linear or branched alkyl group having 1 to 4 carbon atoms. ) 7. The optical recording medium according to claim 5, wherein the fungicide is a thiophenate compound represented by the following general formula [II]. Embedded image (In the formula, R ³ and R ⁴ each independently represent a linear or branched alkyl group having 1 to 4 carbon atoms.) 8. The optical recording medium according to claim 5, wherein the fungicide is a dioxoimidazolidine compound represented by the following general formula [III]. Embedded image (In the formula, R ⁵ represents a linear or branched alkyl group having 1 to 4 carbon atoms.) 9. A fungicide represented by the following general formula [IV]:
The optical recording according to claim 5, which is an isothiazolone-based compound.
Medium. Embedded image(Where R⁶Is a hydrogen atom, optionally substituted C₁~
C₁₈Alkyl group, alkenyl which may be substituted
Group, an optionally substituted cycloalkyl group, substituted
Optionally substituted aryl group, optionally substituted polycyclic carbon
Prime ring, optionally substituted heteroaromatic ring, substituted
An optional sulfonylaminocarbonyl group;
⁷Is a hydrogen atom, halogen atom, cyano group,
Divergent C ₁~ C_FourRepresents an alkyl group represented by⁸Is hydrogen
Atom, halogen atom, optionally substituted alkylthio
O group, an optionally substituted heterocyclic thio group,
An optionally substituted arylthio group, an optionally substituted
Alkylcarbonyl group, aryl group which may be substituted
Rubonyl group, optionally substituted alkoxycarbonyl
Group, aryloxycarbonyl which may be substituted
Represents a group. R⁷, R⁸Is cyclized to form a 5- to 7-membered carbocyclic ring
May be shown. n shows the integer of 0-2. )
Optical recording medium containing an isothiazolone compound
Recording medium. 10. The optical recording medium according to claim 5, wherein the fungicide is contained in the protective layer or the print receiving layer in an amount of 0.01% by weight or more. 11. At least a light absorbing layer on a transparent substrate,
In the method for manufacturing an optical recording medium in which a light reflecting layer, a protective layer and / or a print receiving layer are sequentially formed, the protective layer or the print receiving layer is formed by the following components: i) a resin oligomer component containing an acrylic acrylate oligomer; B) a resin monomer component; c) particles obtained by pulverizing and crushing silk yarn. D) a method for producing an optical recording medium, which is formed by applying a mixture of a photopolymerization initiator and then performing photopolymerization. 12. At least a light absorbing layer on a transparent substrate,
In the method for manufacturing an optical recording medium in which a light reflecting layer, a protective layer and / or a print receiving layer are sequentially formed, the protective layer or the print receiving layer is formed by the following components: i) a resin oligomer component containing an acrylic acrylate oligomer; B) a resin monomer component, c) fine particles obtained by pulverizing silk yarn, d) a photopolymerization initiator, e) a mixture of a fungicide, and then photopolymerization to form an optical recording medium. Production method. 13. The method for producing an optical recording medium according to claim 11, wherein the resin oligomer contains at least one oligomer selected from the group consisting of urethane oligomers, ester oligomers, and ether oligomers. . 14. At least a light absorbing layer on a transparent substrate,
In the method for producing an optical recording medium, in which a light reflecting layer, a protective layer and / or a print receiving layer are sequentially formed, the protective layer or the print receiving layer is obtained by dissolving a resin in a solvent and pulverizing fine particles by pulverizing silk thread. A method for producing an optical recording medium, comprising forming a suspension by applying a suspended resin solution, followed by drying.