JP4190548B2 - Optical disk resin substrate recovery method and apparatus. - Google Patents

Description

  The present invention relates to a method for recovering a resin substrate of an optical disc, which recovers a polycarbonate resin from a work obtained by grinding an optical disc in which a reflection film is adhered between two polycarbonate substrates, such as a digital video disc (DVD), and Relates to the device.

  In recent years, optical discs, such as compact discs (CD) and digital video discs (DVD), in which an aluminum reflective film is formed on a polycarbonate substrate have been used in large quantities. A DVD is configured by forming a reflective film between two polycarbonate substrates. When discarding such an optical disc, a polycarbonate resin (hereinafter sometimes abbreviated as a polycarbonate resin) is recovered as a resource.

  In order to recover the polycarbonate resin from the optical disc, a finely pulverized work (chip) is put into an alkaline aqueous solution, and the reflective film and the protective film are dissolved and peeled off. The alkaline aqueous solution is an aqueous solution such as caustic soda, which is dissolved and peeled while stirring at high temperature. This is described, for example, in Patent Document 1 below.

Japanese Patent No. 2615277

  In the prior art, a reflective film is dissolved and peeled off by a chemical reaction of an alkaline agent on a work obtained by grinding an optical disk. When a reflective film is formed between two polycarbonate substrates as in DVD, the alkaline aqueous solution does not penetrate to the inside between the polycarbonate substrate and the reflective film, so that the reflective film can be sufficiently dissolved and removed. become unable. For this reason, there is a problem that a high-quality polycarbonate resin that can be reused cannot be recovered.

  In order to promote the chemical reaction of the aqueous alkali solution and improve the dissolution and removal rate of the reflective film, it has been proposed to increase the alkali concentration, to treat under high pressure or to inject a surfactant. However, there is a practical disadvantage that the properties of the polycarbonate resin are lowered and become brittle, and the transparency is lost.

  An object of the present invention is to provide a method and an apparatus for recovering a resin substrate of an optical disc that can recover a high-quality polycarbonate resin without deteriorating the properties of the polycarbonate resin.

  A feature of the present invention is that a workpiece in an alkaline aqueous solution is struck by a hammer and a gap is formed between the polycarbonate substrate and the reflective film.

  In the present invention, since an air gap is formed between the polycarbonate substrate and the reflective film, the alkaline aqueous solution quickly permeates between the polycarbonate substrate and the reflective film. Therefore, even if the alkali concentration of the aqueous alkali solution is reduced, almost all of the reflective film can be melted and removed, and high-quality polycarbonate resin can be recovered without deteriorating the properties of the polycarbonate resin.

  The workpiece is prepared by pulverizing an optical disk in which a reflective film is adhered between two polycarbonate substrates. In the cleaning tank, the workpiece is put into the injected alkaline aqueous solution, and the reflective film is dissolved and peeled off. The heating means heats the aqueous alkaline solution injected into the cleaning tank with steam, and the stirring means agitates the aqueous alkaline solution injected into the cleaning tank with air. The hammer has two fixed and movable hammer plates in which a plurality of protrusions are formed on the opposing contact surface, and is disposed in an alkaline aqueous solution. A hammer strikes a workpiece and peels off the end of the polycarbonate substrate and the reflective film by a shearing force to form a gap.

1 and 2 show an embodiment of the present invention. FIG. 1 is a partially sectional view showing the overall structure, and FIG.

  1 and 2, the cleaning tank 1 is a rectangular parallelepiped housing, and a work insertion port 2 is formed in the ceiling plate 1a. The work inlet 2 is sealed with a hatch 3. An aqueous solution supply pipe 5 for supplying an alkaline aqueous solution is provided above the left side plate 1 d of the cleaning tank 1. An alkaline aqueous solution 4 is injected into the cleaning tank 1 from an aqueous solution supply pipe 5. The workpiece 6 is charged into the alkaline aqueous solution 4 from the charging port 2. Only two workpieces 6 are illustrated.

Steam generated in the boiler 7 is guided to the steam supply pipe 8 and supplied to the alkaline aqueous solution 4 in the cleaning tank 1 through the valve 9. The alkaline aqueous solution 4 is heated by the steam generated in the boiler 7. The steam supply pipe 8 is disposed through the ceiling plate 1 a of the cleaning tank 1. The boiler 7, the steam supply pipe 8, and the valve 9 constitute a heating means.

  Bearings 11 and 12 are provided on the outer surfaces of the right side plate 1 c and the left side plate 1 d of the cleaning tank 1. The rotary shaft 10 is pivotally supported by bearings 11 and 12 through the side plates 1c and 1d. The pulley 13 is fixed to the left end of the rotating shaft 10 and is connected to the pulley 15 via the belt 14. The pulley 15 is mechanically connected to the motor 16. The rotational force of the motor 16 is transmitted to the rotary shaft 10 via the pulley 15, the belt 14, and the pulley 13.

  Three air nozzles 18 are attached to the floor plate 1 b of the cleaning tank 1. The air nozzle 18 jets the compressed air supplied from the blower 17 and stirs the alkaline aqueous solution 4. Although many air nozzles 18 can be attached not only to the floor plate 1b but also to the side plates 1c and 1d, illustration is omitted. The blower 17 and the air nozzle 18 constitute stirring means. A discharge port 19 is formed in the lower portion of the right measuring plate 1 c of the cleaning tank 1. A discharge pipe 20 is connected to the discharge port 19, and an outlet of the discharge pipe 20 is sealed with a sealing door 21.

  As for the rotating shaft 10, the flange 22 is being fixed to four places in the washing tank 1. FIG. As shown in FIG. 2, two hammer shafts 23a and 23b are planted and fixed to the flange 22 in the vertical direction. Circular hammer plates 24a and 24b are fixed to the tips of the hammer shafts 23a and 23b, respectively. The hammer plates 24a and 24b are fixed hammer plates.

  As shown in FIG. 3, the circular hammer plates 25a and 25b have a through hole 27 in the center. The hammer plates 25a and 25b are loosely attached to the through holes 27 through the hammer shafts 23a and 23b. Stoppers 26a and 26b are provided on the hammer shafts 23a and 23b between the flange 22 and the fixed hammer plates 24a and 24b, respectively.

  The hammer plate 25a moves by its own weight between the fixed hammer plate 24a and the stopper 26a, and the hammer plate 25b moves by its own weight between the fixed hammer plate 24b and the stopper 26b. The hammer plates 25a and 25b are movable hammer plates. The hammer is composed of the hammer shaft 23, the fixed hammer plate 24, the movable hammer plate 25 and the stopper 26.

  The fixed hammer plate 24 and the movable hammer plate 25 are made of stainless steel or the like, and have a diameter of about 120 mm and a weight of about 1.5 kg. A plurality of protrusions 28 are formed on the opposing surfaces (opposing contact surfaces) of the fixed hammer plate 24 and the movable hammer plate 25. The protrusion 28 is formed in a conical shape having a flat tip. The protrusion 28 has a tip flat portion with a diameter of about 10 mm. The fixed hammer plate 24 is provided with a projection 28 as shown in FIG. 4, and the movable hammer plate 25 is provided with a projection 28 as shown in FIG.

  The positional relationship between the protrusions 28 of the fixed hammer plate 24 and the movable hammer plate 25 is as shown in FIG. In FIG. 6, the x mark indicates the protrusion position of the fixed hammer plate 24, and the ◯ mark indicates the position of the protrusion 28 of the movable hammer plate 25. The projection positions of the fixed hammer plate 24 and the movable hammer plate 25 are alternately arranged so that the projections 28 of both the hammer plates 24 and 25 are engaged with each other.

  4 and 5 show an example in which the fixed hammer 24 is provided with seven protrusions 28 and the movable hammer 25 is provided with four protrusions 28, but more protrusions 28 are actually provided.

  In this configuration, in order to melt and peel the reflective film from the workpiece, the alkaline aqueous solution 4 is injected into the cleaning tank 1 from the aqueous solution supply pipe 5. The alkaline aqueous solution 4 is preheated to about 40 ° C. in advance and is injected to the level shown in FIG. After injecting the alkaline aqueous solution 4, the hatch 3 is opened to the dotted line position and the workpiece 6 is introduced into the alkaline aqueous solution 4 from the workpiece inlet 2. About 200 kg of workpiece 6 is input. When the loading of the workpiece 6 is completed, the hatch 3 is closed and the workpiece loading port 2 is sealed.

  In this state, the motor 16 is started. The rotational force of the motor 16 is transmitted to the rotary shaft 10 via the pulley 15, the belt 14, and the pulley 13. The rotating shaft 10 is rotationally driven by a motor 16. The two hammer shafts 23a and 23b rotate as the rotation shaft 10 rotates.

  Further, the valve 9 is opened and the steam generated in the boiler 7 is supplied to the alkaline aqueous solution 4 in the cleaning tank 1. The alkaline aqueous solution 4 is heated to about 85 ° C. to 90 ° C. by steam generated in the boiler 7. At the same time, the blower 17 is activated and compressed air is jetted from the air nozzle 18 to stir the alkaline aqueous solution 4.

  Now, as the rotary shaft 10 rotates, the hammer shafts 23a and 23b also rotate. Due to the rotation of the hammer shafts 23a, 23b, the movable hammer plate 25a moves by its own weight between the fixed hammer plate 24a and the stopper 26a, and the movable hammer plate 25b moves by its own weight between the fixed hammer plate 24b and the stopper 26b. .

  The movable hammer plate 25a falls by its own weight when the fixed hammer plate 24a moves upward, and is locked to the stopper 26a as shown in FIGS. 1 and 2, and falls by its own weight when the fixed hammer plate 24a moves downward. And abuts against the fixed hammer plate 24a.

  Similarly, when the fixed hammer plate 24b moves downward, the movable hammer plate 25b falls by its own weight and comes into contact with the fixed hammer plate 24b as shown in FIGS. 1 and 2, and the fixed hammer plate 24b moves upward. Then, it falls by its own weight and is locked to the stopper 26a.

  The movable hammer plate 25a and the movable hammer plate 25b repeatedly abut against and come into contact with the fixed hammer plate 24a or the fixed hammer plate 24b. When the movable hammer plate 25 and the fixed hammer plate 24 collide, it is assumed that the workpiece 6 exists between the hammer plates 24 and 25 as shown in FIG. When the two hammer plates 24 and 25 collide and come into contact with each other, the workpiece 6 is sandwiched and hit as shown in FIG.

  When the work 6 is struck by both the hammer plates 24 and 25, the end portions of the polycarbonate substrate 29 and the reflection film 30 are peeled off by a shearing force to form a gap 31 as shown in FIGS. 8 (a) and 8 (b). The alkaline aqueous solution 4 enters the gap 31 and quickly penetrates between the polycarbonate substrate 29 and the reflective film 30. Therefore, even if the alkali concentration of the alkaline aqueous solution is reduced, almost all of the reflective film 30 can be melted and removed.

  When the melting removal process of the reflection film 30 is completed in this way, the left side of the cleaning tank 1 is lifted with a cylinder (not shown), the sealing door 21 of the discharge pipe 20 is opened, and the work collection tank (not shown) is opened from the discharge pipe 20. ). The work collection tank is provided with a mesh, and the polycarbonate resin 29 and the alkaline aqueous solution 4 are separated.

  In this way, the reflective film is dissolved and removed. Since an air gap is formed between the polycarbonate substrate of the workpiece and the reflective film, the alkaline aqueous solution quickly permeates between the polycarbonate substrate and the reflective film. Therefore, even if the alkali concentration of the aqueous alkali solution is reduced, almost all of the reflective film can be melted and removed, and high-quality polycarbonate resin can be recovered without deteriorating the properties of the polycarbonate resin.

  FIG. 9 shows another embodiment of the present invention. In the embodiment of FIG. 9, the cleaning tank is formed in a sealed cylindrical shape, and the cleaning tank is rotated so that the workpiece is hit with a hammer.

  In FIG. 9, the cleaning tank 40 is configured in a sealed cylindrical shape with lids on both open ends of the cylinder. The shaft coupling members 43 and 44 are fixed to the both disk surfaces covered with the lid. One ends of the rotating shafts 48 and 49 are connected to shaft connecting members 43 and 44, and the other ends are supported by bearings 11 and 12, respectively. The bearings 11 and 12 are respectively fixed to support members 41 and 42 that support the entire cleaning tank 40.

  The fixed hammer plates 24a and 24b are fixed to the inner surface of the cleaning tank 40 and connected to one end and the other end of one hammer shaft 23, respectively. Further, as shown in FIG. 10, a plurality of stirring plates 45 are provided on the inner surface of the cleaning tank 40 along the circumferential direction. The aqueous solution supply pipe 5 for injecting the alkaline aqueous solution 4 is flexible and is guided into the cleaning tank 40 by a free joint 46, and the steam supply pipe 8 for supplying heated steam is also flexible and is inserted into the cleaning tank 40 by a free joint 47. Guided.

  9 is the same as that of the first embodiment shown in FIG.

  In the second embodiment, when the motor 16 is driven, the cleaning tank 40 rotates. Therefore, the workpiece 6 is struck by being sandwiched between the hammer plates 24 and 25. Therefore, as in the first embodiment, the work 6 has a gap 31 between the polycarbonate substrate 29 and the reflective film 30. The alkaline aqueous solution 4 enters the gap 31 and quickly penetrates between the polycarbonate substrate 29 and the reflective film 30. Therefore, even if the alkali concentration of the alkaline aqueous solution is reduced, almost all of the reflective film 30 can be melted and removed.

  In the second embodiment, when the melting removal process of the reflective film 30 is finished, the hatch 3 is opened with the work insertion port 2 on the lower side and discharged.

  As described above, according to the present invention, since a gap is formed between the polycarbonate substrate and the reflective film, the alkaline aqueous solution quickly permeates between the polycarbonate substrate and the reflective film. Therefore, even if the alkali concentration of the aqueous alkali solution is reduced, almost all of the reflective film can be melted and removed, and high-quality polycarbonate resin can be recovered without deteriorating the properties of the polycarbonate resin.

  In the first and second embodiments, the hammer plate is circular, but it goes without saying that the same effect can be obtained with a square plate or a polygonal plate.

  In addition, it is clear that the hammer can form a gap in the workpiece without providing a protrusion depending on the size of the hammer plate.

It is the side view which carried out the partial cross section which shows one Example of this invention. It is an example block diagram of the hammer of this invention. It is an example block diagram of the hammer of this invention. It is an example block diagram of the fixed hammer board of this invention. It is an example block diagram of the movable hammer board of this invention. It is explanatory drawing of the protrusion position of the hammer board in this invention. It is explanatory drawing of the hammer effect | action in this invention. It is explanatory drawing of the hammer effect in this invention. It is the side view which carried out the partial cross section which shows the other Example of this invention. It is attachment explanatory drawing of the stirring board in the Example of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Cleaning tank, 2 ... Work inlet, 3 ... Hatch, 4 ... Alkaline aqueous solution, 5 ... Aqueous solution supply pipe, 6 ... Work, 7 ... Boiler, 8 ... Steam supply pipe, 9 ... Valve, 10 ... Rotating shaft, 11 , 12 ... bearings, 13, 15 ... pulley, 14 ... belt, 16 ... motor, 17 ... blower, 18 ... air nozzle, 19 ... discharge port, 20 ... discharge pipe, 21 ... sealed door, 22 ... flange, 23 ... hammer Axis, 24 ... fixed hammer plate, 25 ... movable hammer plate, 26 ... stopper, 27 ... through hole, 28 ... projection, 29 ... polycarbonate substrate, 30 ... reflective film, 31 ... gap.

Claims (2)

A work obtained by pulverizing an optical disk having a reflective film adhered between two polycarbonate substrates is placed in an alkaline aqueous solution, and the alkaline aqueous solution is heated and stirred to dissolve and peel the reflective film. A hammer having two fixed and movable hammer plates each having a plurality of protrusions formed on the opposing abutting surface is disposed in the alkaline aqueous solution, and the workpiece is struck by the hammer to strike the polycarbonate substrate and the polycarbonate substrate. A method for recovering a resin substrate of an optical disc, wherein an end portion of a reflective film is peeled to form a gap. A workpiece obtained by pulverizing an optical disk having a reflective film adhered between two polycarbonate substrates, a cleaning tank in which the workpiece is put into an injected alkaline aqueous solution, and the reflective film is dissolved and peeled; A heating means for heating the alkaline aqueous solution injected into the cleaning tank with steam, an agitating means for air-stirring the alkaline aqueous solution injected into the cleaning tank, and the workpiece disposed between the alkaline aqueous solutions. There is provided a fixed hammer having a plurality of protrusions formed on the opposing abutting surface and a hammer having two movable hammer plates, which form an air gap by peeling off the polycarbonate substrate and the end of the reflective film. An optical disk resin substrate collecting apparatus characterized by the above.

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