JP2006318570A - Manufacturing method of optical information recording medium, and optical information recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress occurrence of errors by limiting charging of a substrate to a minimum during edge cleaning. <P>SOLUTION: The manufacturing method of an optical information medium includes: a substrate forming step; a recording layer forming step; an edge cleaning step; a reflection film forming step; and a bonding step. Before the edge cleaning step is started, and when cleaning liquids 42 are discharged from discharge nozzles 38 and 40, destaticizing blow 46 (ionized air) is applied via a destaticizing blow device 44 to an area including the discharge nozzles 38 and 40 and a substrate 10, the maximum charging voltage of the substrate 10 is set equal to or less than 7kV in the edge cleaning step. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an optical information recording medium and an optical information recording medium, in which an information recording layer is formed on a substrate, and information can be recorded and / or reproduced by irradiation with laser light.

  In general, as an optical information recording medium (optical disc) capable of recording information only once by a laser beam, there are a write-once type CD (so-called CD-R), a DVD-R, etc., and a conventional CD (compact disc). Compared to production, it has the advantage that a small amount of CD can be supplied to the market quickly and at a reasonable price, and the demand is increasing with the recent spread of personal computers and the like.

  A typical structure of a CD-R type optical information recording medium is a recording layer made of an organic dye on a transparent disk-shaped substrate having a thickness of about 1.2 mm, a light reflecting layer made of a metal such as gold, and a resin. These protective layers are laminated in this order (see, for example, JP-A-6-150371).

  Also, the DVD-R type optical information recording medium has a structure in which two disc-shaped substrates (thickness of about 0.6 mm) are bonded with each information recording surface facing inward, and the amount of recorded information It has the feature that there are many.

  Information writing (recording) on these optical information recording media is performed by irradiating laser light, and the irradiated portion of the dye recording layer absorbs the light to locally increase the temperature, A chemical change (eg, pit generation) occurs and information is recorded by changing its optical properties.

  On the other hand, reading (reproduction) of information is usually performed by irradiating a laser beam having the same wavelength as that of the recording laser beam, and a portion where the optical characteristics of the dye recording layer are changed (recording portion by generating pits). Information is reproduced by detecting a difference in reflectance from a non-changed part (unrecorded part).

  Conventionally, in order to prevent dust and dust from adhering to the optical information recording medium due to static electricity generated in the manufacturing process of the optical information recording medium, an antistatic agent or static elimination is performed.

  For example, in Patent Document 1, in an optical disc having a recording layer on one side of a resin transparent substrate and a hard coat layer on the other side, the hard coat layer is made of a cured film of an actinic ray curable resin, and An example in which an organic compound layer made of a film containing an organic antistatic agent is provided between a resin transparent substrate and a hard coat layer has been proposed. In this case, it can be formed by a spin coating method excellent in mass productivity, and exhibits an effect of preventing dust adsorption on the surface under both high humidity conditions and low humidity conditions. It is possible to provide an optical disc having a hard coat layer that retains optical uniformity and further sufficient scratch resistance.

  In Patent Document 2, an ultraviolet curable resin that is shaken off when the optical disk substrate is rotated in a state where an ultraviolet curable resin for forming a protective film is supplied to the surface of the optical disk substrate is collected by a resin tray, and a resin paint tray is obtained. An example has been proposed in which the ultraviolet curable resin recovered in (2) is reused after being filtered by a second filter. In particular, an example is disclosed in which the protective film formed of an ultraviolet curable resin is a protective film formed on a recording film or a reflective film, or a charging protective film formed on a laser light irradiation surface of an optical disk substrate. .

  Also, in Patent Document 3, conventionally, a static eliminator is installed on the spindle so that the static electricity charged when the optical disk is accumulated on the spindle can be removed, and the optical disk accumulated on the spindle is set to 5000V. Examples have been proposed in which static elimination is possible to the following.

  Further, conventionally, there has been proposed a technique for preventing the peeling of the information recording layer by improving the adhesion between the outer peripheral portion and the inner peripheral portion of the information recording layer or the like in the optical information recording medium.

  For example, in Patent Document 4, a recording layer and a reflective layer are provided in this order, and both the recording layer and the outer end of the reflective layer are retracted inward to form an exposed surface on the outer end surface, or recording is performed. A substrate and a reflective layer are provided in this order, and both the recording layer and the outer end portion of the reflective layer are retracted inward to form one substrate having an exposed surface on the outer end surface and the same shape as the one substrate. Are bonded together with the adhesive layer in contact with the reflective layer surface and the exposed surface so that the recording layer side is on the inner side, respectively, so that the outer edge of the two substrates is high. It is disclosed that by realizing the adhesiveness, an optical information recording medium having a more simplified structure that does not peel off and is provided with good storage stability can be provided.

  In Patent Document 5, a disk-shaped substrate having a hole in the center, a disk-shaped substrate deformed so as to increase the surface area of the outer peripheral side end on the surface on which the recording layer is formed, and a recording layer and Two disc-shaped recording plates are prepared, in which the reflective layer is formed in this order, and the outer peripheral side end of the reflective layer is retracted inward. A sandwich-type optical information recording medium that is arranged as described above and bonded together by an adhesive layer is disclosed.

  In Patent Document 6, two disc-shaped substrates having a hole in the center in which a recording layer, a reflective layer, and a protective layer are provided in this order, or a recording layer, a reflective layer, and a protective layer are arranged in this order. A sandwich-type light in which a disc-shaped substrate having a hole in the center provided and a disc-shaped protective plate having the same shape as the substrate are bonded together via an adhesive layer so that the recording layer side is inside. In an information recording medium, it is disclosed that both the recording layer and the outer end of the reflective layer are retracted inward to expose the surface of the outer end of the substrate, and a protective layer is bonded to the exposed surface. .

  In Patent Document 7, when the dye recording layer 204 at the peripheral edge 206 of the substrate 202 is removed by jetting the solvent 620 while rotating the substrate 202, the solvent 620 is removed from the inside of the substrate 202 from above. An example in which the dye recording layer 204 at the peripheral edge 206 of the substrate 202 is removed by spraying toward the peripheral edge 206 is disclosed. In this case, in the edge cleaning step of removing the dye recording layer at the peripheral edge of the substrate by spraying the liquid, the splash of the removed dye recording layer is prevented from adhering to the light reflecting layer, the back surface of the substrate, etc. The yield of the optical information recording medium can be improved.

JP-A-6-318341 JP-A-8-7347 JP 2002-279702 A Japanese Patent Laid-Open No. 10-134419 Japanese Patent Laid-Open No. 10-134420 Japanese Patent Laid-Open No. 10-106038 JP 2000-331387 A

  By the way, the conventional concept of static elimination is that in Patent Documents 1 and 2, an antistatic film is formed as a protective film on the optical information recording medium itself, and in Patent Document 3, an optical information recording medium in the manufacturing process or a completed process is completed. When the optical information recording medium is stocked by the spindle, the spindle is neutralized. In other words, the conventional static elimination is a technology mainly intended to prevent static electricity from being generated when a large number of optical information recording media are stocked.

  Therefore, in Patent Documents 1 and 2, for example, dust or dust may adhere to the optical information recording medium due to generation of static electricity during the manufacturing process until the antistatic film is formed. The same applies to Patent Document 3, and static electricity is generated when processing is actually performed on the substrate of the optical information recording medium, and there is a possibility that dust, dust, or the like may adhere to the optical information recording medium.

  In particular, the edge cleaning process as shown in Patent Documents 4 to 7 has a problem that it is easily affected by static electricity generated on the substrate of the optical information recording medium.

  That is, in the edge cleaning, a portion to be cleaned can be sufficiently washed off, but a part of the cleaning liquid splashes on the recording layer and remains as a defect, resulting in an unfavorable situation in which an error occurs. There's a problem. This is because the cleaning liquid is splashed off due to the substrate being charged. If the charge on the substrate is small, the sprayed cleaning liquid adheres to the edge and is not splashed off. However, if the charge on the substrate is large, it is splashed and scattered around without getting wet.

  Charging of the substrate during edge cleaning is due to the charge that the substrate itself has, due to the charge that the cleaning liquid has, due to the charge that the spindle table on which the substrate is installed, or during edge cleaning. Some are caused by the rotation of the substrate. Among these, the charge generated by the rotation of the substrate during edge cleaning has the greatest influence.

  The present invention has been made in consideration of such problems, and can produce an optical information recording medium that can minimize the charging of the substrate during edge cleaning and suppress the occurrence of errors. It is an object to provide a method and an optical information recording medium.

  An optical information recording medium manufacturing method according to the present invention is an optical information recording medium manufacturing method in which an information recording layer is formed on a substrate, and information can be recorded and / or reproduced by laser light irradiation. A first step of forming an information recording layer; and a second step of removing at least a portion corresponding to the outermost periphery of the information recording layer formed on the substrate. Further, it is characterized in that static elimination is performed.

  Thereby, the charging to the substrate in the second step can be minimized, and the occurrence of errors can be suppressed.

  And in the said manufacturing method, it is preferable that the maximum charged voltage in the said 2nd step is 7 kV or less.

  Further, the second step may remove the portion of the information recording layer by applying a liquid ejected from a nozzle to at least a portion corresponding to the outermost periphery. In this case, since static elimination is performed in the second step, scattering of the cleaning liquid sprayed from the nozzles to the information recording layer can be suppressed, and the occurrence of errors can be suppressed.

  And when the direction along the central axis of the substrate is defined as a vertical direction, it is preferable that an angle formed by the vertical direction of the nozzle is 10 to 45 °.

  Moreover, in this invention, when ejecting a liquid from the said nozzle, you may make it apply static elimination blow.

  Next, an optical information recording medium according to the present invention is manufactured by the above-described method for manufacturing an optical information recording medium according to the present invention. As a result, since the charging of the substrate during edge cleaning is minimized, the occurrence of errors can be suppressed.

  As described above, according to the method for manufacturing an optical information recording medium and the optical information recording medium according to the present invention, it is possible to minimize the charging of the substrate during edge cleaning, and to suppress the occurrence of errors. be able to.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an optical information recording medium manufacturing method and an optical information recording medium according to the present invention applied to, for example, a DVD-R and a CD-R using a dye recording layer will be described below with reference to FIGS. explain.

  First, the manufacturing method according to the first embodiment is a manufacturing method applied to a DVD-R using a dye-type information recording layer, and as shown in FIG. It has a forming step S2, an edge cleaning step S3, a reflective film forming step S4, and an adhesion step S5.

  The substrate production step S1 is a step of producing a substrate by, for example, an injection molding machine, a compression molding machine or an injection compression molding machine, and a resin material such as polycarbonate is injection molded, compression molded or injection compression molded, and is shown in FIG. As shown in the drawing, the substrate 10 on which the concave and convex portions (pregroove 12) representing information such as tracking grooves or address signals is formed on one main surface is manufactured.

  Examples of the material of the substrate 10 include acrylic resins such as polycarbonate and polymetal methacrylate, vinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymers, epoxy resins, amorphous polyolefins, and polyesters. You may use them together. Among the above materials, polycarbonate is preferable from the viewpoint of moisture resistance, dimensional stability, price, and the like.

  The groove depth D of the pregroove 12 is preferably in the range of 0.01 to 0.3 μm, and the half width is preferably in the range of 0.2 to 0.9 μm. In particular, in the case of corresponding to a blue-violet laser, the pregroove 12 preferably has the following range.

  That is, the upper limit of the track pitch of the pregroove 12 is preferably 500 nm or less, more preferably 420 nm or less, still more preferably 370 nm or less, and particularly preferably 330 nm or less. Further, the lower limit is preferably 50 nm or more, more preferably 100 nm or more, further preferably 200 nm or more, and particularly preferably 260 nm or more.

  The upper limit of the width (half width) of the pregroove 12 is preferably 250 nm or less, more preferably 200 nm or less, further preferably 170 nm or less, and particularly preferably 150 nm or less. Further, the lower limit is preferably 23 nm or more, more preferably 50 nm or more, further preferably 80 nm or more, and particularly preferably 100 nm or more.

  The upper limit of the groove depth D of the pregroove 12 is preferably 150 nm or less, more preferably 100 nm or less, still more preferably 70 nm or less, and particularly preferably 50 nm or less. Further, the lower limit is preferably 5 nm or more, more preferably 10 nm or more, further preferably 20 nm or more, and particularly preferably 28 nm or more.

  The upper limit of the angle of the pregroove 12 is preferably 80 ° or less, more preferably 70 ° or less, further preferably 60 ° or less, and particularly preferably 50 ° or less. Further, the lower limit value is preferably 20 ° or more, more preferably 30 ° or more, and further preferably 40 ° or more.

  Each of the upper limit value and the lower limit value related to the pregroove 12 described above can be arbitrarily combined.

  The values of these pregrooves 12 can be measured with an AFM (atomic force microscope). The angle of the pregroove 12 refers to the surface of the substrate 10 before the groove is formed, where the groove depth of the pregroove 12 is D, and an inclined portion having a depth of D / 10 from the surface. This is an angle formed by a straight line connecting the deepest portion of the groove 12 to the inclined portion having a height of D / 10 and one surface of the substrate 10 (for example, the bottom surface of the pregroove 12).

  In order to produce the substrate 10 having such groove-shaped pregrooves 12, it is necessary that the stamper used at the time of injection molding is formed by high-precision mastering. For this mastering, it is preferable to use a DUV (wavelength of 330 nm or less, deep ultraviolet) laser or cutting by EB (electron beam).

  An undercoat layer is preferably formed on the surface of the substrate 10 on the side on which the information recording layer is formed for the purpose of improving the flatness, improving the adhesive force, and preventing the information recording layer from being deteriorated.

  Examples of the material for the undercoat layer include polymethyl methacrylate, acrylic acid / methacrylic acid copolymer, styrene / maleic anhydride copolymer, polyvinyl alcohol, N-methylol acrylamide, styrene / vinyl toluene copolymer, chlorosulfone. Polymer materials such as chlorinated polyethylene, nitrocellulose, polyvinyl chloride, chlorinated polyolefin, polyester, polyimide, vinyl acetate-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, polyethylene, polypropylene, polycarbonate; silane coupling agents And the like.

  The undercoat layer is formed by preparing a solution by dissolving or dispersing the above materials in an appropriate solvent, and then applying this solution to the surface of the substrate by a coating method such as spin coating, dip coating, or extrusion coating. be able to. The thickness of the undercoat layer is in the range of 0.005 to 20 μm, and preferably in the range of 0.01 to 10 μm.

  Next, the recording layer forming step S3 is a step of forming the information recording layer 14 on one main surface of the substrate 10 as shown in FIG. The information recording layer 14 formed in this step is a concept including a layer in which information that can be read by a laser beam is recorded or a layer in which such information can be recorded, and more specifically, The concept includes a pit, a dye recording layer, a phase change recording layer, and the like. Note that the pit is a recess formed in the substrate and does not actually constitute a layer, but in this specification, the information recording layer 14 also includes a pit. That is, in the case of the ROM configuration, the area where the pits are located in the substrate 10 is the information recording layer 14.

  The information recording layer 14 in the manufacturing method according to the first embodiment is preferably a dye-type information recording layer 14 capable of recording information only once with a laser beam. The dye-type information recording layer 14 preferably contains a dye having absorption in the recording wavelength region. Examples of the dye include cyanine dyes, oxonol dyes, metal complex dyes, azo dyes, and phthalocyanine dyes, and oxonol dyes and phthalocyanine dyes are particularly preferable.

  JP-A-4-74690, JP-A-8-127174, 11-53758, 11-334204, 11-334205, 11-334206, 11-334207 The dyes described in JP-A No. 2000-43423, JP-A No. 2000-108513, JP-A No. 2000-158818, and the like are also preferably used.

  The information recording layer 14 is prepared by dissolving a dye in a suitable solvent together with a binder or the like to prepare a dye solution, and then coating the dye solution on one main surface of the substrate 10 to form a coating film. It is formed by drying. In that case, it is preferable that the temperature of the surface which apply | coats a pigment | dye solution is the range of 10-40 degreeC. More preferably, the upper limit is 35 ° C. or lower, further preferably 30 ° C. or lower, and particularly preferably 27 ° C. or lower. Moreover, as a lower limit, it is 15 degreeC or more, It is more preferable that it is 20 degreeC or more, It is especially preferable that it is 23 degreeC. Thus, when the to-be-coated surface temperature of the board | substrate 10 exists in the above-mentioned range, generation | occurrence | production of a coating nonuniformity and a coating failure can be prevented, and the thickness of a coating film can be made uniform. In addition, said upper limit value and lower limit value can be combined arbitrarily, respectively.

  Here, the information recording layer 14 may be a single layer or a multilayer. In the case of a multilayer structure, the information recording layer 14 is formed by performing the coating process a plurality of times.

  The concentration of the dye in the dye solution is in the range of 0.01 to 15% by weight, preferably in the range of 0.1 to 10% by weight, more preferably in the range of 0.5 to 5% by weight, most preferably 0. .5-3 weight range.

  Examples of solvents for the dye solution include esters such as butyl acetate, ethyl lactate, and cellosolve acetate; ketones such as methyl ethyl ketone, cyclohexanone, and methyl isobutyl ketone; chlorinated hydrocarbons such as dichloromethane, 1,2-dichloroethane, and chloroform; and dimethylformamide Amides; Hydrocarbons such as cyclohexane; Ethers such as tetrahydrofuran, ethyl ether, dioxane; Alcohols such as ethanol, n-propanol, isopropanol, n-butanol diacetone alcohol; 2,2,3,3-tetrafluoro-propanol, etc. Fluorinated solvents; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether; .

  The above solvents can be used alone or in combination of two or more in consideration of the solubility of the dye used. In the dye solution, various additives such as an antioxidant, a UV absorber, a plasticizer, and a lubricant may be added according to the purpose.

  Examples of the coating method include a spray method, a spin coating method, a dip method, a roll coating method, a blade coating method, a doctor roll method, and a screen printing method.

  At the time of application, the temperature of the dye solution is preferably in the range of 23 to 50 ° C, more preferably in the range of 24 to 40 ° C.

  The thickness of the information recording layer 14 formed in this way is preferably 300 nm or less, more preferably 250 nm or less, and more preferably 200 nm or less on the groove 12a (projection on the substrate 10). Is more preferable, and 180 nm or less is particularly preferable. The lower limit is preferably 30 nm or more, more preferably 50 nm or more, further preferably 70 nm or more, and particularly preferably 90 nm or more.

  In addition, the thickness of the information recording layer 14 is preferably 400 nm or less, more preferably 300 nm or less, and further preferably 250 nm or less on the land 12b (a concave portion in the substrate 10). The lower limit is preferably 70 nm or more, more preferably 90 nm or more, and further preferably 110 nm or more.

  Furthermore, the lower limit of the ratio of the thickness of the information recording layer 14 on the groove 12a to the thickness of the information recording layer 14 on the land 12b is preferably 0.4 or more, and more preferably 0.5 or more. More preferably, it is more preferably 0.6 or more, and particularly preferably 0.7 or more. The upper limit value is preferably less than 1, more preferably 0.9 or less, further preferably 0.85 or less, and particularly preferably 0.8 or less.

  When the dye solution contains a binder, examples of the binder include natural organic polymer materials such as gelatin, cellulose derivatives, dextran, rosin, and rubber; hydrocarbon resins such as polyethylene, polypropylene, polystyrene, and polyisobutylene. , Polyvinyl chloride, polyvinylidene chloride, vinyl resins such as polyvinyl chloride / polyvinyl acetate copolymer, acrylic resins such as polymethyl acrylate and polymethyl methacrylate, polyvinyl alcohol, chlorinated polyethylene, epoxy resin, butyral And synthetic organic polymers such as resins, rubber derivatives, and initial condensates of thermosetting resins such as phenol / formaldehyde resins.

  When a binder is used in combination as the material of the information recording layer 14, the amount of the binder used is in the range of 0.01 times to 50 times (mass ratio) with respect to the dye, preferably 0.1 times. The amount is in the range of 5 to 5 times (mass ratio).

  Further, the information recording layer 14 can contain various anti-fading agents in order to improve the light resistance of the information recording layer 14. As the anti-fading agent, a singlet oxygen quencher is generally used. As the singlet oxygen quencher, those described in publications such as known patent specifications can be used.

  Specific examples thereof include JP-A Nos. 58-175893, 59-81194, 60-18387, 60-19586, 60-19587, and 60-35054. 60-36190, 60-36191, 60-44554, 60-44555, 60-44389, 60-44390, 60-54892, JP-A-60-47069, JP-A-63-209995, JP-A-4-25492, JP-B-1-38680, and JP-A-6-26028, German Patent 350399, and Examples include those described in Journal of Chemical Society of Japan, October 1992, page 1141.

  The amount of the anti-fading agent such as a singlet oxygen quencher used is in the range of 0.1 to 50% by weight, preferably in the range of 0.5 to 45% by weight, more preferably 3 with respect to the amount of the pigment. It is in the range of -40% by weight, particularly preferably in the range of 5-25% by weight.

  In the above-described example, the solvent coating method in the case where the information recording layer 14 is a dye-type information recording layer has been described. However, the information recording layer 14 is formed by a deposition method such as vapor deposition, sputtering, or CVD according to the physical properties of the recording material. Can also be formed.

  For example, when a phase change metal compound is used as the recording material, it is preferable to form the information recording layer using such a film forming method. Here, any of SbTe, AgSbTe, InAgSbTe, or the like may be used as the phase change metal compound.

  In this embodiment, a spin coater 20 as shown in FIG. 4 is used for applying the dye solution. That is, the substrate 10 put into the spin coater 20 is coated with a dye solution on one main surface thereof, rotated at high speed to make the thickness of the dye solution uniform, and then subjected to a drying process. The As a result, the information recording layer 14 is formed on one main surface of the substrate 10 as shown in FIG.

  As shown in FIG. 4, the substrate 10 put into the spin coater 20 is mounted on the rotary table 22 and held horizontally by a fixture (not shown). Next, a predetermined amount of the dye solution supplied from the pressurizing tank 24 is adjusted by the discharge adjusting valve 26, and is dropped through the discharge nozzle 28 to the inner peripheral side on the substrate 10.

  As described above, the discharge nozzle 28 has a front end surface of the discharge nozzle 28 and an outer side or an inner side within a range of 1 mm or more from the front end surface, or both of the wall surfaces are made of a fluorine compound. In addition, it is difficult to cause deposition of pigments and deposits due to drying, so that a coating film can be formed smoothly without any obstacles such as coating film defects.

  The rotary table 22 can be rotated at high speed by a drive motor 30. The dye solution dropped on the substrate 10 is cast on the surface of the substrate 10 in the outer peripheral direction by the rotation of the turntable 22 and reaches the outer peripheral edge of the substrate 10 while forming a coating film.

  Next, the edge cleaning step S3 is a step of cleaning the outer peripheral edge and the inner peripheral edge (edge portion) of the substrate 10 on which the information recording layer 14 is formed. For example, an edge cleaner 32 shown in FIG. 5 is used. .

  This edge cleaner 32 holds a substrate 10 and rotates it, a drive motor 36 that rotates the rotary table 34 in one direction, and a discharge nozzle 38 for outer periphery (for discharging cleaning liquid (solvent)). Nozzle) and a discharge nozzle 40 for the inner periphery.

  The discharge nozzles 38 and 40 are maintained at angles θ1 and θ2 of about 45 ° with respect to the vertical direction n when the direction along the central axis m of the substrate 10 is defined as a vertical direction (indicated by a dashed line n). ing. A filtration filter (not shown) is attached in the middle of the cleaning liquid piping.

  When the discharge nozzles 38 and 40 come to a predetermined discharge position, as shown in FIGS. 6A and 6B, the cleaning liquid 42 is discharged from the discharge nozzles 38 and 40. In this case, as shown in FIG. 6A. In addition, the cleaning liquid 42 is discharged from the discharge nozzle 38 for the outer periphery toward the outer peripheral edge portion 10 a of the substrate 10 from above in the substrate 10. Further, as shown in FIG. 6B, the cleaning liquid 42 is discharged from the inner peripheral discharge nozzle 40 toward the inner peripheral edge portion 10b of the substrate 10 from the upper side of the substrate 10, and by the discharge of these cleaning liquids 42, As shown in FIG. 7, the information recording layer 14 (shown by a broken line) in the outer peripheral edge portion 10a and the inner peripheral edge portion 10b of the substrate 10 is removed.

  In the first embodiment, before entering the edge cleaning step S3 and when discharging the cleaning liquid 42 from the discharge nozzles 38 and 40, as shown in FIG. Ionized air) is applied to a region including the discharge nozzles 38 and 40 and the substrate 10 so that the maximum voltage of the substrate 10 in this edge cleaning is 7 kV or less. Of course, you may make it abbreviate | omit the static elimination blow process before entering into edge cleaning process S3.

  Thereby, the charging to the substrate 10 in the edge cleaning step S3 can be minimized. In this case, splash of the cleaning liquid 42 discharged from the discharge nozzles 38 and 40 to the information recording layer 14 can be suppressed, and the occurrence of errors can be suppressed.

  Here, preferable conditions in the edge cleaning step S3 will be described. First, as described above, the charged voltage of the substrate 10 is 7 kV or less, preferably 4 kV or less, more preferably 3 kV or less, still more preferably 2 kV or less, and particularly preferably 1 kV or less.

  The cleaning liquid 42 may be anything as long as the information recording layer 14 is not dissolved and the substrate 10 is not dissolved, but diacetone alcohol, dibutyl ether, and 2,2,3,3-tetrafluoro-1-propanol are preferable, and among them, diacetone alcohol is preferable. Most preferred.

  The cleaning start timing is preferably 1 second or more and 4 hours or less after the information recording layer 14 is formed, and more preferably 5 seconds or more and 2 hours or less. When the cleaning start timing is late, the cleaning performance is deteriorated. Conversely, when the cleaning is started earlier, the shape of the edge portion (the outer peripheral edge portion and the inner peripheral edge portion of the information recording layer 14 after the cleaning) is deteriorated.

  The discharge nozzle 38 for the outer periphery has an angle θ1 formed between the axis of the discharge nozzle 38 and the vertical direction n when the direction in which the tip (discharge port) of the discharge nozzle 38 faces the outermost periphery of the substrate 10 is a positive angle. It is installed so as to be ˜60 °, preferably 10˜45 °. The inner circumferential discharge nozzle 40 has an angle θ2 between 0 to 60 ° between the axis of the discharge nozzle 40 and the vertical direction n when the direction in which the tip of the discharge nozzle 40 faces the center of the substrate 10 is a positive angle. Preferably, it is installed so that it may become 10-45 degrees. The distance between the discharge ports of the discharge nozzles 38 and 40 and the substrate 10 is 0.3 to 5 mm, preferably 0.5 to 3 mm, and more preferably 0.7 to 2 mm. If the angles θ1 and θ2 formed by the axes of the discharge nozzles 38 and 40 and the vertical direction n are set to negative angles or the positive angles are set too large, the shape of the edge portion is disturbed.

  The number of the outer peripheral discharge nozzles 38 and the inner peripheral discharge nozzles 40 is preferably one or more and four or less, more preferably one or two, respectively. If there are too many discharge nozzles, the amount of the cleaning liquid 42 increases, which is disadvantageous in terms of cost. In addition, an unstable flow may occur at the start of discharge, and this may be splashed and scattered on the information recording layer 14 to cause a surface defect or error. The probability of occurrence of defects and errors increases.

The discharge pressure of the cleaning liquid 42, 0.3 kg / cm ² or more, preferably 3 kg / cm ^2. More preferably, it is 0.5 kg / cm ² or more and 2 kg / cm ² , and 0.7 kg / cm ² or more and 1.7 kg / cm ² is most preferable. If the pressure is too high, not only a large amount of the cleaning liquid 42 is used, but also splashing occurs, and the probability of occurrence of surface defects and errors increases. On the other hand, if it is too low, the shape of the edge portion is disturbed.

  The diameter of the discharge nozzles 38 and 40 is preferably 0.1 to 0.8 mm, more preferably 0.2 to 0.6 mm. If the diameter is too large, a turbulent flow is generated in the flow of the cleaning liquid 42, and the shape of the edge portion is disturbed. On the other hand, if it is too small, the amount of the cleaning liquid 42 is insufficient and sufficient cleaning cannot be performed.

When the diameters of the discharge nozzles 38 and 40 are narrow, it is preferable to increase the discharge pressure. In this case, the product of the diameter and the pressure (mm · kg / cm ² ) is preferably 0.2 to 2.4, more preferably 0.3 to 1, and most preferably 0.4 to 0.6.

  The discharge time of the cleaning liquid 42 is preferably 0.1 to 1 second. More preferably, it is 0.2 to 0.8 seconds, and most preferably 0.3 to 0.6 seconds. If the time is too long, not only a large amount of the cleaning liquid 42 is used, but also the probability of occurrence of surface defects and errors due to the disorder of the shape of the edge portion and the scattering of the splashes increases. On the other hand, if the time is too short, sufficient cleaning cannot be performed.

  The rotation speed of the substrate 10 at the start of discharging the cleaning liquid 42 is preferably 1000 rpm to 10,000 rpm. More preferably, it is 2000-8000 rpm, Most preferably, it is 3000-6000 rpm. If the rotational speed is too slow, the shape of the edge portion is disturbed. On the other hand, if the speed is too fast, the probability of occurrence of surface defects and errors due to splashing of the droplets increases.

  Drying is performed after edge cleaning. At this time, it is preferable to rotate the substrate 10 for the purpose of drying (swing-off rotation). The rotation speed of the substrate 10 is preferably 3000 rpm or more and 10,000 rpm or less. More preferably, it is 4000-8000 rpm, Most preferably, it is 5000-7000 rpm. If the rotation speed is too slow, drying will be slow and productivity will be reduced. On the other hand, if the speed is too high, not only the rotation drive unit is damaged (motor, bearing, etc.), but also the sprayed cleaning liquid 42 scatters inside the coating cup (not shown) of the edge cleaning machine 32, thereby causing surface defects. And the probability of occurrence of errors increases.

  The discharge amount of the cleaning liquid 42 is preferably 0.2 cc or more and 3 cc or less. More preferably, it is 0.4 cc or more and 2 cc or less, and most preferably 0.6 cc or more and 1.5 cc or less. If the discharge amount is too small, cleaning is insufficient, and if it is too large, splashing of the droplets occurs, and the probability of occurrence of surface defects and errors increases.

  Next, as shown in FIG. 8, the reflective film forming step S <b> 4 is a step of forming the light reflecting layer 50 on the entire surface excluding the outermost peripheral portion and the innermost peripheral portion in one main surface of the substrate 10. The device is used.

  The light-reflective substance that is the material of the light-reflecting layer 50 is a substance having a high reflectance with respect to laser light. Examples thereof include Mg, Se, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, and Mo. W, Mn, Re, Fe, Co, Ni, Ru, Rh, Pd, Ir, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Si, Ge, Te, Pb, Po, Sn , Bi and other metals and metalloids or stainless steel. These substances may be used alone or in combination of two or more. Or you may use as an alloy.

  Among these, Cr, Ni, Pt, Cu, Ag, Au, Al, and stainless steel are preferable. Particularly preferred is Au, Ag, Al or an alloy thereof, and most preferred is Au, Ag or an alloy thereof.

  Next, in the bonding step S5, as shown in FIG. 9, the dummy substrate 52 is bonded to one main surface of the substrate 10 (the surface on which the information recording layer 14 and the light reflecting layer 50 are formed) via the bonding layer 54. It is a process. Through this process, the optical information recording medium 100 is completed. As a material of the adhesive layer 54, an adhesive 56 or an adhesive 58 can be used. The dummy substrate 52 is made of the same material and the same size as the substrate 10 described above. The pregroove 12 formed on the substrate 10 is not formed on the dummy substrate 52.

  As the adhesive 56 used for bonding the substrate 10 and the dummy substrate 52, for example, a UV curable resin, an EB curable resin, a thermosetting resin, or the like is preferably used, and in particular, a UV curable resin is preferably used. .

  When a UV curable resin is used as the adhesive 56, the UV curable resin may be prepared as it is or by dissolving it in an appropriate solvent such as methyl ethyl ketone or ethyl acetate, and supplied from the dispenser to the substrate surface. In order to prevent warpage of the produced optical information recording medium 100, it is preferable that the UV curable resin as the adhesive 56 has a small curing shrinkage. Examples of such UV curable resins include UV curable resins such as “SD-640” manufactured by Dainippon Ink and Chemicals, Inc.

  For example, a predetermined amount of the adhesive 56 is applied onto the bonding surface of the substrate 10, the dummy substrate 52 is placed thereon, and then the adhesive 56 is uniformly applied between the substrate and the dummy substrate 52 by spin coating. It is preferable to cure after spreading.

  The thickness of the adhesive layer 54 made of the adhesive 56 is preferably in the range of 0.1 to 100 μm, more preferably in the range of 0.5 to 50 μm, and still more preferably in the range of 10 to 30 μm.

  In addition, as the adhesive layer 54 used for bonding the dummy substrate 52, an acrylic, rubber-based, or silicon-based adhesive 58 can be used. From the viewpoint of transparency and durability, an acrylic-based adhesive can be used. An adhesive 58 is preferred. The acrylic pressure-sensitive adhesive 58 is mainly composed of 2-ethylhexyl acrylate, n-butyl acrylate, etc., and has a short chain alkyl acrylate or methacrylate, for example, methyl acrylate, ethyl acrylate, methyl methacrylate, etc. It is preferable to use a copolymer of acrylic acid, methacrylic acid, acrylamide derivative, maleic acid, hydroxylethyl acrylate, glycidyl acrylate, or the like that can be a cross-linking point with a crosslinking agent. The glass transition temperature (Tg) and the crosslinking density can be changed by appropriately adjusting the mixing ratio and type of the main component, the short chain component, and the component for adding a crosslinking point.

  Examples of the crosslinking agent used in combination with the pressure-sensitive adhesive 58 include isocyanate-based crosslinking agents. Examples of the isocyanate-based crosslinking agent include tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, hexamethylene isocyanate, xylylene diisocyanate, naphthylene-1,5-diisocyanate, o-toluidine isocyanate, isophorone diisocyanate, triphenylmethane triisocyanate, and the like. Isocyanates, products of these isocyanates with polyalcohols, and polyisocyanates formed by condensation of isocyanates can be used. Commercially available products of these isocyanates include Coronate L, Coronate HL, Coronate 2030, Coronate 2031, Millionate MR, Millionate HTL manufactured by Nippon Polyurethane; Takenate D-102 and Takenate D-110N manufactured by Takeda Pharmaceutical Co., Ltd. , Takenate D-200, Takenate D-202; Death Module L, Death Module IL, Death Module N, Death Module HL;

  The adhesive 58 may be applied uniformly on the bonding surface of the substrate 10 in a predetermined amount, and after the dummy substrate 52 is placed thereon, may be cured, or in advance on one surface of the dummy substrate 52. A fixed amount may be uniformly applied to form a pressure-sensitive adhesive coating film, and the pressure-sensitive adhesive coating film may be bonded to the bonding surface of the substrate 10 and then cured.

  The thickness of the adhesive layer 54 composed of the pressure-sensitive adhesive 58 is preferably in the range of 0.1 to 100 μm, more preferably in the range of 0.5 to 50 μm, and still more preferably in the range of 10 to 30 μm.

  Next, a manufacturing method according to the second embodiment will be described with reference to FIG.

  The manufacturing method according to the second embodiment is a manufacturing method applied to a CD-R using a dye-type information recording layer, and as shown in FIG. 10, a substrate manufacturing step S11 and a recording layer forming step. S12, edge cleaning step S13, reflective film forming step S14, and protective layer forming step S15.

  The substrate manufacturing step S11, the recording layer forming step S12, the edge cleaning step S13, and the reflective film forming step S14 are the substrate manufacturing step S1, the recording layer forming step S2, and the edge cleaning step of the manufacturing method according to the first embodiment described above. Since almost the same steps as S3 and the reflective film forming step S4 are performed, the description thereof is omitted here, and the protective layer forming step S15 will be mainly described.

  In the protective layer forming step S15, as shown in FIG. 11, the UV curable liquid 60 is dropped on a part of one main surface of the substrate 10 (the surface on which the information recording layer 14 and the light reflecting layer 50 are formed). Thereafter, the substrate 202 is rotated at a high speed, so that the coating thickness of the UV curable liquid 60 dropped onto the substrate 10 is made uniform over the entire surface of the substrate 10. In the second embodiment, the time is managed so that the time from the formation of the light reflecting layer 50 to the application of the UV curable liquid 60 is not less than 2 seconds and not more than 5 minutes.

  Thereafter, the UV curable liquid 60 on the substrate 10 is irradiated with ultraviolet rays. As a result, a protective layer 62 made of a UV curable resin is formed so as to cover the information recording layer 14 and the light reflecting layer 50 formed on one main surface of the substrate 10, and the optical information recording medium 102 is configured. .

The protective layer 62 is provided on the light reflecting layer 50 for the purpose of physically and chemically protecting the information recording layer 14 and the like. The protective layer 62 can be provided on the side of the substrate 10 where the information recording layer 14 is not provided for the purpose of improving scratch resistance and moisture resistance. Examples of the material used for the protective layer 62 include inorganic substances such as SiO, SiO ₂ , MgF ₂ , SnO ₂ , and Si ₃ N ₄ , and thermoplastic resins, thermosetting resins, and UV curable resins. Mention may be made of organic substances.

  The protective layer 62 can be formed, for example, by laminating a film obtained by extrusion of plastic on the light reflecting layer 50 and / or the substrate 10 with an adhesive. Or you may provide by methods, such as vacuum evaporation, sputtering, and application | coating. In the case of a thermoplastic resin or a thermosetting resin, it can also be formed by dissolving these in a suitable solvent to prepare a coating solution, and then coating and drying the coating solution.

  In the case of a UV curable resin, as described above, the coating solution is prepared as it is or dissolved in an appropriate solvent, and then the coating solution is applied and then cured by irradiation with UV light. Can do. In these coating liquids, various additives such as an antistatic agent, an antioxidant, and a UV absorber may be added according to the purpose. The layer thickness of the protective layer 62 is generally provided in the range of 0.1 to 100 μm.

  Also in the second embodiment, before entering the edge cleaning step S3 and when the cleaning liquid 42 is discharged from the discharge nozzles 38 and 40, the discharge blow 46 (ionized air) is discharged from the discharge nozzle 38 and the discharge nozzle 38 and 40. 40 and the region including the substrate 10 so that the maximum voltage of the substrate 10 in this edge cleaning is 7 kV or less.

  Thereby, the charging to the substrate 10 in the edge cleaning step S3 can be minimized. In this case, splash of the cleaning liquid 42 discharged from the discharge nozzles 38 and 40 to the information recording layer 14 can be suppressed, and the occurrence of errors can be suppressed. Of course, you may make it abbreviate | omit the static elimination blow before entering into edge cleaning process S3.

  Here, one experimental example is shown. In this experimental example, for Examples 1 to 3 and Comparative Examples 1 and 2, the maximum charged voltage at the time of cleaning, the maximum error at the outer periphery, the maximum error at the outer periphery after 168 hours at a temperature of 60 ° C. and a humidity of 85%, and defects Yield was measured.

  Examples 11 to 1 and Comparative Examples 1 and 2 were all prepared as follows. First, the substrate 10 had a diameter of 120 mm, an inner diameter of 15 mm, a thickness of 0.6 mm, a groove depth of the pregroove 12 of 140 nm, and a groove width of the pregroove 12 of 300 nm.

  1.5 g of oxonol dye represented by the following chemical formula was prepared in 100 cc of tetrafluoropropanol, and the transmission density OD was 0.77 (measured at a wavelength of 570 nm) by spin coating.

  In edge cleaning, as shown in FIG. 5, the discharge nozzles 38 for the outer periphery and the discharge nozzles 40 for the inner periphery are divided into 45 ° angles θ1 and θ2 between the axes of the discharge nozzles 38 and 40 and the vertical direction n. It installed so that it might become. The inner diameter of the discharge ports of the discharge nozzles 38 and 40 is 0.5 mm. As the cleaning liquid 42, diacetone alcohol was used. Then, the rotary table 34 was rotated 4000 rpm, and the cleaning liquid 42 was discharged for 3 seconds to clean the edge portions (the outer peripheral edge portion 10a and the inner peripheral edge portion 10b of the substrate 10).

  The light reflecting layer 50 was formed by sputtering an Ag film having a thickness of 150 nm.

  As the adhesive layer 54, the above-mentioned adhesive “SD-640” manufactured by Dainippon Ink & Chemicals, Inc. was used, and a predetermined amount was applied on the bonding surface of the substrate 10, and the dummy substrate 52 was placed thereon. Thereafter, the adhesive 56 was spread uniformly between the substrate 10 and the dummy substrate 52 by spin coating, and then cured to bond the substrate 10 and the dummy substrate 52 together.

  The dummy substrate 52 is the same as the substrate 10.

  The breakdown of Examples 1 to 3 and Comparative Examples 1 and 2 is that, as shown in FIG. 12, Example 1 does not perform the process of applying the static elimination blow before the edge cleaning, and performs the static elimination from the start to the end of the edge cleaning. Blow processing was performed. In Example 2, the process of applying the static elimination blow before the edge cleaning was performed, and the process of applying the static elimination blow from the start to the end of the edge cleaning was further performed. In Example 3, the process of applying the static elimination blow before the edge cleaning was performed, and further the process of applying the static elimination blow until the cleaning liquid was discharged in the edge cleaning.

  In Comparative Example 1, the process of applying the static eliminating blow was performed before the edge cleaning, and the process of applying the static eliminating blow was not performed from the start to the end of the edge cleaning. In Comparative Example 2, the process of applying the static elimination blow before the edge cleaning was not performed, and further, the process of applying the static elimination blow from the start to the end of the edge cleaning was not performed.

  The maximum charged voltage as a measurement item was measured using a probe-type charged voltmeter. For the maximum error at the outer periphery and the maximum error at the outer periphery after 168 hours at a temperature of 60 ° C. and a humidity of 85%, the maximum error at a point with a radius of 56 mm was measured. The maximum error was measured as follows. In Examples 1 to 3 and Comparative Examples 1 and 2, using an OMT2000 (Pulstec) evaluation machine, the wavelength of the laser beam is 780 nm (pickup to NA 0.5), the linear velocity is 1.2 m / sec, EFM modulation The signal was recorded with a recording power of 7 mW. Thereafter, a signal was reproduced with a laser output of 0.5 mW using a laser beam having the same wavelength as the recording laser beam, and an error (block error: BLER) was measured. In particular, the maximum error rate of the outer peripheral portion after 168 hours at a temperature of 60 ° C. and a humidity of 85% is useful for confirming storage stability.

  The yield due to defects was NG for defects with a contrast of 100 μm or more.

  The results of the experimental example are shown in FIG. First, with respect to the maximum charged voltage during cleaning, Examples 1 to 3 were 1.2 kV, 0.7 kV, and 0.9 kV, and good results were obtained. In Comparative Examples 1 and 2, the voltage was 8 kV and 12 kV, which was higher than that in Examples 1 to 3.

  The maximum errors in the outer peripheral portion were 120, 80, and 90 in Examples 1 to 3, and good results were obtained. Comparative example 1 and 2 are 150 and 300, and it turns out that there are many errors compared with Examples 1-3.

  The maximum errors in the outer peripheral portion after 168 hours at a temperature of 60 ° C. and a humidity of 85% were 180, 130 and 130 in Examples 1 to 3, and the increase rate of errors was low, and good results were obtained. That is, it can be seen that Examples 1 to 3 have high storage stability. On the other hand, Comparative Examples 1 and 2 are 250 and 600, indicating that the rate of increase in errors is high and that there are many errors as compared with Examples 1 to 3.

  The yields due to defects were 94%, 96%, and 97% in Examples 1 to 3, and good results were obtained. The comparative examples 1 and 2 are 92% and 88%, and it turns out that a yield is a little low compared with Examples 1-3.

  Note that the optical information recording medium manufacturing method and the optical information recording medium according to the present invention are not limited to the above-described embodiments, and various configurations can be adopted without departing from the gist of the present invention. .

It is process drawing which shows the manufacturing method which concerns on 1st Embodiment. It is sectional drawing which abbreviate | omits and shows a board | substrate produced at a board | substrate preparation process. In a recording layer formation process, it is sectional drawing which abbreviate | omits and shows the state which formed the information recording layer in one main surface of a board | substrate. It is a schematic block diagram which shows the spin coater used in a recording layer formation process. It is a schematic block diagram which shows the edge cleaning machine and static elimination blower which are used in an edge cleaning process. FIG. 6A is a cross-sectional view showing a state in which the information recording layer on the outer peripheral edge of the substrate has been cleaned with a discharge nozzle for the outer periphery, and FIG. 6B shows the inner peripheral edge of the substrate with the discharge nozzle for the inner periphery. It is sectional drawing which abbreviate | omits and shows the state which wash | cleaned the information recording layer. It is sectional drawing which abbreviate | omits and shows the state which cleaned the edge part of the information recording layer in the edge cleaning process. It is sectional drawing which abbreviate | omits and shows the state which formed the light reflection film in one main surface of a board | substrate in a reflective film formation process. FIG. 10 is a cross-sectional view showing a partially omitted state in which an optical information recording medium is completed by bonding a dummy substrate to one main surface of a substrate via an adhesive layer in an adhesion step. It is process drawing which shows the manufacturing method which concerns on 2nd Embodiment. FIG. 5 is a cross-sectional view showing a state where a protective layer is formed on one main surface of a substrate to complete an optical information recording medium in a protective layer forming step, with a part omitted. It is a table | surface figure which shows the breakdown of Examples 1-3, the comparative examples 1 and 2, and the result of an experiment example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Board | substrate 12 ... Pre-groove 14 ... Information recording layer 28, 38, 40 ... Discharge nozzle 32 ... Edge washing machine 44 ... Static elimination blow apparatus 46 ... Static elimination blow 50 ... Light reflection layer 52 ... Dummy board 54 ... Adhesive layer 100, 102 ... Optical information recording media

Claims (6)

In an optical information recording medium manufacturing method in which an information recording layer is formed on a substrate and information can be recorded and / or reproduced by irradiation with a laser beam.
A first step of forming an information recording layer on the substrate;
A second step of removing at least a portion corresponding to the outermost periphery of the information recording layer formed on the substrate;
A method for producing an optical information recording medium, wherein neutralization is performed during the second step. In the manufacturing method of the optical information recording medium of Claim 1,
The method of manufacturing an optical information recording medium, wherein the maximum charged voltage in the second step is 7 kV or less. In the manufacturing method of the optical information recording medium of Claim 1 or 2,
In the second step, the portion of the information recording layer corresponding to at least the outermost periphery is applied with a liquid ejected from a nozzle, thereby removing the portion. . In the manufacturing method of the optical information recording medium of Claim 3,
When the direction along the central axis of the substrate is defined as the vertical direction,
The method of manufacturing an optical information recording medium, wherein an angle between the nozzle and the vertical direction is 10 to 45 °. In the manufacturing method of the optical information recording medium of Claim 3 or 4,
A method for producing an optical information recording medium, wherein neutralization blow is applied when a liquid is ejected from the nozzle.   The optical information recording medium manufactured by the manufacturing method of the optical information recording medium of any one of Claims 1-5.

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