JPH1135733A - Recycling of disk-like information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a colorant component to be recovered without fail from the substrate of a disk-like information recording medium comprising the substrate and a colorant layer, a reflective film, and a protective film laminated thereon by separating the substrate from the reflective film and bringing the substrate into contact with a soln. capable of dissolving the colorant layer. SOLUTION: The substrate is separated from the reflective film pref. by the exposure to ultrasonic waves in a medium. The colorant layer is removed e.g. by dipping in a solvent capable of dissolving the colorant or by spraying the solvent. The solvent used here is pref. the one which does not affect a polycarbonate constituting the substrate, examples being alcoholic solvents, 1,2-ethylenediol, glycerol, Cellosolve solvents, and hydroxyketone solvents. Thus, the resin of the substrate is made reusable as a clear resin. In recovering the colorant, it is pref. separated from impurities by filtration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recycling a disc-shaped information recording medium on which a substrate, a dye layer, a reflective film, and a protective layer are laminated.

[0002]

2. Description of the Related Art Disc-shaped information recording media such as optical discs are widely used for recording music, images, information and the like because of their high density recording capability. Above all, compact discs (CDs) and optical discs belonging to the family are currently used in large quantities. Against this background, recycling of optical disks such as compact disks has begun to be considered in consideration of the recent problem of dust. The optical disk that currently accounts for most of the market is C
It is read-only like D. For example, as shown in FIG. 8, a CD has a laminated structure of a polycarbonate substrate L3, an aluminum reflective film L2, and a protective layer L1.

[0003] In the method of recycling a disk proposed so far, there is a method in which a disk is directly crushed and molded. In this case, the components of the protective layer and the reflective film are also mixed into the molded product. Therefore, only the reflection film cannot be collected, and the molded product is not transparent, and the pulverized product can be used only for limited applications. Alternatively,
The disk is immersed in an acid or alkali solution to dissolve the aluminum reflective film and separate the protective film and the substrate, thereby regenerating the substrate resin. In this method, the recycled substrate is transparent and can be reused for a relatively wide range of uses, but it is difficult to recover the reflective film.

[0004] By the way, not only read-only but also recordable optical disks are on the market. There are several types of recordable ones, but the one related to the present invention includes a substrate L7, a dye layer L6, a reflective film L5, and a protective layer L4 as shown in FIG. It is an optical disk, and this type usually corresponds to writing only once. Such a type is called a CD-R (write-once compact disc). For example, in a CD-R, a polycarbonate substrate, an organic dye such as a cyanine dye and an additive such as a quencher, a gold reflective film, and an ultraviolet curable resin such as an acrylic resin are used. FIG.
As shown in FIG. 0, there is a DVD-R (write-once high-density recording disk: digital video disk) in which two pieces of this type are bonded together with an adhesive or the like. That is, the protective layers L11 and L11 are adhered by the adhesive layer B, and the dye layer L9 and the gold reflective film L are provided on each substrate L8.
10 and a protective layer L11 are sequentially laminated. Since expensive dyes are used in these types of discs in addition to the substrate, recovery of the dye components is also desired.

[0005]

In the recycling method proposed so far, for example, in which the reflective film and the substrate resin are recovered by buffing, the dye component is polished by the buff together with the reflective film and the dye is regenerated. Was difficult.
SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide a method of recycling a disc-shaped information recording medium capable of reliably recovering a dye component from a substrate of the disc-shaped information recording medium.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to separate a reflective film from a substrate of a disc-shaped information recording medium having a substrate, a dye layer, a reflective film, and a protective layer laminated thereon. This is achieved by a method for recycling a disc-shaped information recording medium, which comprises contacting a solution that dissolves a dye layer to recover a dye component from a substrate. In the present invention, the substrate and the reflective film of the disc-shaped information recording medium on which the substrate, the dye layer, the reflective film, and the protective layer are laminated are separated, and then a solution for dissolving the dye layer is brought into contact with the substrate. Thereby, the dye component is recovered from the substrate. Therefore, it is possible to reliably collect only the dye component from the substrate without performing a mechanical process such as buffing.

In the present invention, preferably, the substrate and the reflection film can be reliably separated from each other by irradiating ultrasonic waves in the medium to separate the substrate and the reflection film.

In the present invention, preferably, only the dye component can be recovered from the resin substrate by adding the solution for dissolving the dye layer to separate the dye component and recovering the dye from the resin substrate.

In the present invention, preferably, when the dye is recovered, the dye is filtered to separate the dye and impurities, so that only the pure dye containing no impurities can be recovered.

[0010]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Note that the embodiments described below are preferred specific examples of the present invention,
Although various technically preferable limits are given, the scope of the present invention is not limited to these modes unless otherwise specified in the following description.

First, FIG. 1 shows an example of a recycling apparatus for implementing an embodiment of a method for recycling a disc-shaped information recording medium according to the present invention. An information recording medium (hereinafter, referred to as a disk) 1 to be processed by the recycling apparatus 100 shown in FIG. 1 will be briefly described with reference to FIG. The disc 1 is, for example, a kind of optical disc, CD-R (write-once compact disc).
It is a laminate of a polycarbonate substrate 1d, a dye recording layer 1c, a gold reflection layer 1b as a reflection film, and a UV (ultraviolet curing) resin top coat layer 1a. The polycarbonate substrate 1d is provided with a guide groove 1e.

[0012] The recycling apparatus 100
If the gold reflection layer 1b can be separated from the polycarbonate substrate 1d, not only can the gold reflection layer 1b be reused, but also the polycarbonate substrate 1d and the dye recording layer 1c can be used.
Will be reused. The recycling apparatus 100 shown in FIG.
1, an operating means 60, an ultrasonic oscillator 22 as a vibration generating means, a base 31 and the like.

The mounting plate 85 of the operating means 60 is fixed vertically upright with respect to the base 31. The ultrasonic cleaning tank 21 is preferably set or fixed detachably on the base 31 near the mounting plate 85. This ultrasonic cleaning tank 21 contains water 1 as a medium.
1 is stored in a predetermined amount. An ultrasonic oscillator 22 is arranged on the inner bottom surface of the ultrasonic cleaning tank 21. Operation means 6
0 indicates that one or a plurality of discs 1
1 is a device for disposing the disc 1 out of the water 11 after disposing it in the water 11 in the disc 1 and recovering the gold reflection layer 1b.

An air table cylinder 82 as driving means is incorporated in the mounting plate 85 of the operating means 60. A rising end stopper 84 is fixed to the upper end of the air table cylinder 82, and a falling end stopper 83 is attached to the lower end of the cylinder 82. The cylinder 82 can move the table 81 by air pressure in the Z direction (vertical direction) along the rod 82a.

The moving table 81 has a cleaning jig 91
(Holding body) is attached. This cleaning jig 91
Is for detachably holding one or more disks 1. FIG. 3 shows a part of the cleaning jig 91, and grooves 91h are formed at predetermined intervals L in the middle of the cleaning jig 91 (in FIG. 3, for example, two grooves 9 are formed).
1h). The largest diameter d1 of the cleaning jig 91 is set smaller than the inner diameter of the disc 1, and the cleaning jig 91
Can be inserted. In each groove 91h, a portion forming the center hole of the disk 1 is located. The disk 1 moves a small distance in the Z direction, or the cleaning jig 9
It is also possible to move in one axial direction or to rotate along the rotation direction R.

As the water 11 in FIG. 1, for example, pure water or tap water can be used. FIG. 4 shows the recycling apparatus 1 of FIG.
The control block 00 is simply shown. Control unit 101
Are the start switch 102 and the air table cylinder 8
2. It is connected to the ultrasonic oscillator 22 and the like.

The flaw forming means 600 shown in FIG. 5 preferably forms a flaw on the gold reflection layer 1b or the UV resin top coat layer 1a of the disk 1, or at least on the UV resin top coat layer 1a. I do. This flaw forming means 60
Reference numeral 0 denotes an apparatus for scratching the gold reflection layer 1b and the UV resin top coat 1a of the disk 1 before the recycling processing by the recycling apparatus 100 in FIG.

In the operation example of the embodiment shown in FIG. 1, a used disk, a disk in which a defect has occurred in the manufacturing process, or an unused disk is mounted on the cleaning jig 91 as it is. Gold reflective layer 1b of disk 1
And the UV resin top coat layer 1a is peeled and collected. However, the scratch forming means 600 of FIG. 5 actively scratches the disk 1 of such a kind in advance with respect to the gold reflection layer 1b and the UV resin top coat layer 1a as shown in the pattern of FIG. By doing so, it is intended to increase the collection efficiency of the gold reflective layer and the like by the recycling device 100 as shown in FIG.

The flaw forming means 600 includes a positioning portion 5
8, setting plate 56, support plate 57, two linear guides 53,
53 and a mold 51. The mold 51 is fixed to the lower ends of the linear shafts 52, 52 of the linear guides 53, 53. Moreover, the center of the mold 51 is
Is fixed to the rod 55a. The disc 1 is positioned such that the gold reflective layer 1b and the UV resin top coat layer 1a on the label side face the mold 51.

A protrusion 59 for forming a groove is provided on the lower surface of the mold 51.
Are formed. The shape of the protrusion 59 can form a flaw 1f on the label surface side of the disk 1 shown in FIG. 6, for example.

When the cylinder 55 of the flaw forming means 600 shown in FIG. 5 is operated, the mold 51 is moved along the linear guides 53,53.
Descends in the direction of arrow Z1 to preferably dispose the gold reflective layer 1b and the UV resin top coat layer 1 on the label side of the disc 1.
With respect to a, a flaw can be formed in a pattern as shown in FIG. As described above, the protrusion 59 (blade portion) of the mold 51 forms a flaw on the gold reflection layer 1b and the UV resin top coat layer 1a in advance, and the recycling apparatus 10 of FIG.
The separation and recovery of the gold reflection layer 1b and the like by 0 can be performed in a shorter time.

In the embodiment of the present invention, the disk is left as it is, or after the reflective layer is scratched or crushed using the scratch forming means 600 as shown in FIG. 5, ultrasonic waves are irradiated in water. The frequency of the ultrasonic wave generated by the ultrasonic oscillator 22 of FIG. 1 used at this time is not particularly limited in intensity, and can be oscillated by a normal ultrasonic vibrator.
It may be about 8 KHz. Lower frequencies are expected to be more efficient, but require more expensive equipment. When the energy density generated by the ultrasonic vibration is 0.5 W / cm ² or more, efficient separation can be performed. It is also possible to process one disk or a plurality of disks simultaneously. It is possible to circulate the water of the medium during and after the ultrasonic treatment, regardless of the treatment.By circulating, it is possible to promote peeling and to prevent the peeled reflective film etc. from re-adhering to the substrate. it can.

Before irradiating the ultrasonic waves,
Scratching the protective film side of the disk accelerates the peeling of the reflective film 1b, which is very effective. There is no particular limitation on the method of making the scratch, and a heating wire, a laser beam, or the like can be used in addition to the blade (projection 59). There is no particular limitation on the method of scratching, such as the depth, arrangement and number, but the most preferable depth is the depth reaching the dye layer from the protective film side. Water, which is a medium for irradiating ultrasonic waves, does not need to be particularly high-purity, and an additive can be added as needed. For example, by adding a surfactant,
It is effective for promoting peeling, draining water after treatment, preventing re-adhesion of the reflective film, and the like. Further, the temperature of water at the time of ultrasonic irradiation is not particularly limited, and a sufficient effect can be obtained at room temperature. By the above ultrasonic treatment, the optical disk is separated into a substrate, a reflective film and a protective layer.

By the way, although the dye recording layer 1c is adhered on the substrate 1d, the resin of the substrate 1d can be used as a recycled material by a process such as crushing.
However, if the dye component remains, the regenerated resin is colored and its use is limited. Therefore, as a method of removing the dye recording layer 1c from the substrate 1d, a method of immersing in a solvent for dissolving the dye or spraying the solvent may be considered. The solvent used at this time is not particularly specified, but a solvent which does not affect the polycarbonate of the substrate and dissolves the dye component is preferable. For example, alcohol solvents such as ethanol, methanol, isopropyl alcohol and n-butanol, 1,2-ethylenediol, glycerin and the like, and further cellosolve solvents such as methyl cellosolve and ethyl cellosolve, 2-hydroxy-2-methyl-3-
Hydroxy ketone solvents such as butanone, 4-hydroxy-2-butanone, and diacetone alcohol can be used. As a result, the dye recording layer 1c is dissolved and the substrate 1
The resin of d can be reused as a transparent resin. At this time, if a general-purpose solvent such as acetone or toluene is used,
The solvent is absorbed by the polycarbonate substrate, making it difficult to regenerate the resin of the substrate 1d. Further, the solvent can be used by mixing, if at least the solvent is contained,
For example, the object of the present invention can be achieved by appropriately mixing ethanol and water.

After the treatment as described above, the extracted dye component is separated from other components by a method such as filtration, and further purified into a reusable dye component by a physicochemical method. The purification method at this time is not particularly limited, but for example, a purification method such as liquid chromatography, recrystallization, or an adsorption method can be used. At this time, the pigment used is easily decomposed, so that it is desirable to treat it in a cool and dark place.

Next, a recycling method by the recycling apparatus 100 shown in FIG. 1 will be described with reference to FIGS. With the moving table 81 raised, one or a plurality of disks 1 are set by the operator or automatically in each groove 91h of the cleaning jig 91 as shown in FIG. In this state, the diameter direction of each disk 1 is substantially oriented in the Z direction (vertical direction), and is positioned at a predetermined interval L. Also, the width B of the groove 91h
Is set to be larger than the thickness of the disk 1. Therefore, in this state, the disk 1 can be rotated and moved along the rotation direction R by the cleaning jig 91.
The disc 1 can also be moved up and down in the direction, and the disc 1 can also move slightly in the axial direction.

Next, the moving table 81 is lowered by the cylinder 82. In the state of being lowered, each disk 1
It will be completely immersed in water 11. When the operator presses the start switch 102 in FIG. 4, the control unit 101 starts the ultrasonic oscillator 22. This ultrasonic oscillator 22 has, for example, 26
By oscillating at a frequency of KHz at an output of 600 W for about 10 seconds, the UV resin top coat layer 1a and the gold reflection layer 1b of the disc 1 shown in FIG.
From the polycarbonate substrate 1d.

The mechanism of this peeling (cleaning) is generally assumed to be performed by two actions. One is
Cavitation caused by vibration, and the other is physical and chemical reaction promoting action. In the embodiment of the present invention, since water is used as a medium,
It seems that the chemical reaction promoting effect is small.

In general, when an ultrasonic wave is vertically incident on a rigid body or the like, a wave that does not travel is generated because the incident wave and the reflected wave overlap. This is called a standing wave. Due to the effect of the standing wave, peeling (cleaning) unevenness occurs. In order to prevent this, unevenness is prevented by vertically moving or rotating the disk 1 as an object in the water 11 as a medium during cleaning.

In the case of the embodiment of the present invention, in particular, by using the axial cleaning jig 91 having a gap in the hole diameter of the center hole of the disk 1, the flow generated by the vibration of the water 11 as the medium is The rotation of the disk 1 prevents uneven peeling. The ultrasonic oscillator 22 is stopped, and the moving table 81 is raised. Moving table 81
The disc 1 is removed by the cleaning jig 91 with the height raised. Gold reflective layer 1b and UV resin top coat layer 1
The disk 1 after peeling a is composed of the dye recording layer 1c and the polycarbonate substrate 1d as shown in FIG. The water 11 after peeling contains the UV resin top coat layer 1
a, The gold reflection layer 1b floats or precipitates.

The water, which is the medium, can be easily separated from the top coat layer 1a and the gold reflection layer 1b by a mesh or the like.
The gold reflection layer 1b is recycled as a valuable material.

In the embodiment of the present invention, the ultrasonic oscillator is operated only when the disk is in the water.
It may be always started. FIG. 7 shows an example of a method for recycling the disc-shaped information recording medium described above. Step S1 : Preferably, at least the protective layer of the disk is scratched. Step S2 : Ultrasonic vibration is applied to the disk in the medium. Step S3 : The gold reflection layer (metal film, metal layer) is peeled from the substrate. Step S4 : A gold reflective layer and a protective layer (protective film) separated from the substrate are obtained. Step S5 : The protective film is removed from the gold reflective layer by heating and burning the film at a temperature near the melting point of the gold reflective layer, for example, about 1200 ° C. This gives only gold. Steps S6, S7, S8 : The dye from the substrate from which the gold reflective layer has been separated is brought into contact with the solvent in step S8 to collect only the resin substrate, for example. Step S9 : The dye obtained in Step S6 is completely separated from impurities and the dye by, for example, filtering with a mechanical filter. Step S10 : The filtered dye is purified in a column to obtain a pure dye in step S11. In this way, only the polycarbonate substrate can be separated in step S7, only pure gold can be obtained in step S5, and pure dye can be obtained in step S11. In this way, the resin substrate to be recycled can be collected and recycled as a substrate material for a disc-shaped information recording medium or the like. This substrate is pelletized to form a polycarbonate resin pellet.

[0033]

EXAMPLE In the following example, a 12 cm CD-
On a polycarbonate substrate for R, a dye (compound 1: benzindoline-based perchlorate dye) and a quencher (compound 2: nitrophenylamine-based quencher) are mixed at a weight ratio of 1: 1 and diacetone alcohol is added. As a solvent, spin coating (about 0.1 micron in thickness), gold is deposited in about 0.1 micron in thickness, then UV-curable resin is spin-coated, then cured by UV irradiation to form a protective film. Mold disks were used. After recording this disc with a CD-R drive manufactured by Sony Corporation, the following processing was performed. An ultrasonic cleaner (26 KHz, 600 W) manufactured by Kaijo Corporation was used as an ultrasonic irradiation device, and tap water was used as a medium. (1) The disk was suspended in the washing layer and sonicated for 10 minutes. Substrate with dye, protective film with metal film,
It was separated into metal powder of the reflection film. (2) A 1 cm lattice-shaped scratch was made on the protective film side of the disk with a razor. Next, ultrasonic waves were applied for 2 minutes in the same manner as in (1).
It was separated into a substrate to which a dye was adhered, a protective film to which a metal film was adhered, and a metal powder of a reflective film. Instead of this razor, the flaw forming means 600 of FIG. 5 may be used. (3) The disk was cut into a size of about 2 cm square with a cutter, and ultrasonic waves were applied for 5 minutes while stirring. It was separated into a substrate resin to which a dye was adhered, a protective film to which a metal film was adhered, and metal powder to a reflective film. (4) The protective film, the reflective film, the dye layer, and a part of the substrate were scraped off from the protective film side of the disk with a razor. When the shaved portion was immersed in ethanol, the pigment component was dissolved. Next, a dye solution was obtained by filtration. (5) Under conditions of (1), solvents other than ethanol were examined. The effect of dye extraction on substrate resin is summarized below. In parentheses are solubility parameters.

[Table 1]

[Table 2]

[Table 3] The solvents shown in Table 1 have the solubility of the dye and do not affect the substrate, but the solvents shown in Table 2 are not preferable because the solvent of the dye has an effect on the substrate. The solvents shown in Table 3 are not suitable for use because they do not dissolve the dye. (6) The solvent was removed from the dye solution extracted by the method of (1) to (5) using an evaporator to obtain a solid. Next, it was separated and purified by silica gel chromatography. At this time, elution of each component was performed by gradually adding ethanol to chloroform, and chloroform: ethanol = 20:
1 → 1: 1), a gradient method in which the polarity of the solvent was changed.

The compound recovered by the above method is
Separated into three components. Proton NMR of these components
(Nuclear magnetic resonance) and FT-IR (Fourier infrared spectrometer)
And the absorption spectrum was measured with a spectrometer. Next, the separated components were identified by comparing these results with Compounds 1 and 2. The results are shown below. Component 1: Aromatic compound (considered as a decomposition product of the dye) Component 2: Benzindoline perchlorate dye (Compound 1
Component 3: Nitrophenylamine-based compound (quencher of compound 2) Components 2 and 3 are the same as the original composition. It was confirmed that the dye and the quencher could be recovered.
Therefore, they can be used again for manufacturing discs.

The type of disc-shaped information recording medium is a CD.
The present invention is applicable not only to (compact discs) and CD-Rs but also to other types of discs, for example, other types of optical discs such as high density recording discs (DVD) and laser discs (LD) and magneto-optical discs Applicable.

In the embodiments shown in FIGS. 1 and 5, the discs 1 are held substantially parallel to the vertical direction and are held by the cleaning jig. However, the present invention is not limited to this. It may be held so as to be inclined, or other holding forms may be used. In the case where the cleaning jig is held, only one or a plurality of cleaning jigs may be used. Ultrasonic vibration by an ultrasonic oscillator is used to apply vibration to the disk. However, the present invention is not limited to this, and it is of course possible to use another type of vibration oscillator.

[0037]

As described above, according to the present invention,
The dye component can be reliably recovered from the substrate of the disc-shaped information recording medium.

[Brief description of the drawings]

FIG. 1 is a diagram showing a preferred embodiment of a recycling apparatus for carrying out a method for recycling a disc-shaped information recording medium of the present invention.

FIG. 2 is a diagram showing an example of a disk to be recycled.

FIG. 3 is a diagram showing a state in which the cleaning jig in FIG. 1 holds several disks.

FIG. 4 is a diagram showing a control unit block of the recycling apparatus of FIG. 1;

FIG. 5 is a diagram showing an example of a flaw forming means for flawing at least a protective layer of a disk.

FIG. 6 is a diagram showing an example of a flaw formed by the flaw forming means.

FIG. 7 is a flowchart showing an example of a method of recycling a disc-shaped information recording medium according to the present invention.

FIG. 8 is a diagram showing an example of a disc-shaped information recording medium.

FIG. 9 is a diagram showing an example of a disc-shaped information recording medium.

FIG. 10 is a diagram showing an example of a disc-shaped information recording medium.

[Explanation of symbols]

1 ... Disc (disc-shaped information recording medium), 1b
... Gold reflective layer (reflective film), 1c ... Dye recording layer (dye layer), 1d ... Polycarbonate substrate (substrate), 1
1 ... water (medium), 21 ... ultrasonic cleaning tank, 22
..Ultrasonic oscillators (vibration generating means)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FIG11B 7/26 B09B 5/00 ZABQ

Claims (4)

[Claims] 1. A disc-shaped information recording medium having a substrate, a dye layer, a reflective film, and a protective layer laminated thereon is separated from the reflective film, and the substrate is contacted with a solution for dissolving the dye layer. A method for recycling a disc-shaped information recording medium, comprising recovering a dye component from a substrate. 2. The method for recycling a disc-shaped information recording medium according to claim 1, wherein the substrate and the reflection film are separated by irradiating ultrasonic waves in the medium. 3. The method for recycling a disc-shaped information recording medium according to claim 1, wherein a dye component is separated by adding a solution for dissolving the dye layer to recover the dye from the resin substrate. 4. The method for recycling a disc-shaped information recording medium according to claim 3, wherein the dye is filtered to separate the impurity from the impurity when the dye is collected.