JP2006007465A - Polyester resin support recovering method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester resin support recovering method for recovering a support, which can be recycled as the raw material of the support of a recording material, from the recording material, wherein a coating film is formed on the support using a natural polymeric binder and a synthetic polymeric binder, with good productivity and profitability. <P>SOLUTION: The sheetlike recording material, wherein at least one coating film is provided on the polyester resin support, is cut to form a chip like recording material and the chip like recording material is treated with an alkaline treatment liquid to separate/remove the coating film from the chip like recording material to recover the polyester resin support. In this polyester resin support recovering method, a recovery apparatus having a cutting part for cutting the sheetlike recording material in a laminated state to obtain the chip like recording material, a treatment part for treating the chip like recording material with the alkaline treatment liquid, a first separation treatment part, a second separation treatment part, a neutralization treatment part and a washing and drying part is used. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for recovering a polyester resin support from a recording material having at least one coating film on the polyester resin support.

  Polyester resins such as polyethylene terephthalate and polyethylene naphthalate are used as a support for recording materials such as silver halide photographic light-sensitive materials, heat-developable photographic light-sensitive materials, ink-jet recording materials, and magnetic recording materials because of their excellent characteristics, and liquid crystal displays. It is also widely used in the information recording industry as an optical film used in various display devices of organic EL displays. The case of a photographic photosensitive material as an example of a recording material using a polyester resin support will be schematically described with reference to the drawings.

  FIG. 5 is a schematic sectional view of a photographic light-sensitive material.

  In the figure, 8 indicates a photographic material. 8a indicates a polyester resin support, and 8b and 8c indicate undercoat layers. 8d represents a photosensitive layer of a coating film formed on the polyester resin support 8a via the undercoat layer 8b, and 8e represents a protective layer of the coating film formed on the photosensitive layer 8d. Reference numeral 8f denotes a coating layer backing layer formed on the polyester resin support 8a via the undercoat layer 8c. The photosensitive layer 8d may be composed of multiple layers as required, or may not be coated with a protective layer. For the photosensitive layer 8d, the protective layer 8e, and the backing layer, a natural polymer binder or a synthetic polymer binder is selected and used depending on the type of photographic photosensitive material produced. In the present invention, in the case of a photographic light-sensitive material, the coating film is a generic name including a photosensitive layer, a protective layer, and a backing layer.

  In recent years, the information recording industry has undergone remarkable development and the number of polyester resin materials used has been rapidly increasing. Along with this, the amount of waste products (for example, production scraps, defective products generated in the product inspection process, etc.) and used products generated in the manufacturing process are increasing.

  In fact, most of these polyester resin wastes are used in landfill or incineration without being effectively used, but in landfill there is no decay, and incineration generates dioxins depending on the incineration conditions. It is also a cause of increasing the global environmental load. Moreover, there is a problem of loss of polyester raw material, which is not preferable from the viewpoint of resource saving.

  In particular, using these polyester-based resin supports, for recording materials using synthetic polymer materials as the binder of the coating film, it cannot be recovered in a state where it can be reused as a polyester-based resin support, Most of the used products and production scraps were not effectively used, and inevitably, incineration treatment was performed at a high temperature in order to suppress the generation of dioxins. For this reason, the incinerator is quickly damaged due to the high-temperature incineration process, which causes a problem of maintenance costs.

  In order to solve these problems, methods for recovering a polyester resin support from a recording material using the polyester resin support have been studied. For example, a printing plate-making film using polyethylene terephthalate (PET) as a support as a polyester resin with a copolymer of vinylidene chloride, itaconic acid, acrylic acid or the like as an undercoat layer is shredded to an appropriate size and alkali metal A method is known in which PET is recovered by heat treatment at 50 to 95 ° C. together with a cationic surfactant in an aqueous salt solution (see, for example, Patent Document 1).

  A polyester resin support having an undercoat layer (hereinafter also referred to simply as a support) and a silver halide photographic light-sensitive material using the support are crushed into chips, and a surfactant (nonionic surfactant, cationic surfactant) And an anionic surfactant) are used together, and a method of recovering the support by heating with stirring at a temperature of 70 to 100 ° C. with an alkaline treatment liquid containing sodium hydroxide or potassium hydroxide is known. (For example, see Patent Document 2).

  However, in the collection methods described in Patent Document 1 and Patent Document 2, when a support is recovered from a recording material on which a synthetic polymer binder is used on a support and a coating film is formed, the peeled coating film and alkaline treatment Sludge generated by the treatment with the liquid cracks generated when cutting the sheet-like recording material into chip-like recording material, mixing into the remaining support without entering the cracks occurs, and the support for the recording material The current situation is that the purity is insufficient for reuse as a raw material and it cannot be used.

  In particular, when reused as a raw material for a support for recording materials, the required items are 1) physical properties (color tone, molecular weight distribution, etc.) are not changed, and 2) adverse effects on performance (for example, photographic sensitivity). In the case of materials, there are no contamination of impurities that give rise to fog, sensitivity abnormalities such as sensitization / desensitization, etc.), and 3) no contamination of foreign matters that adversely affect the image when taken.

From these situations, a support for a recording material (especially for a photographic light sensitive material having a high purity requirement) from a recording material in which a coating film is formed using a natural polymer binder and a synthetic polymer binder for the support. Development of a method for recovering a support in a state where it can be reused as a raw material is desired.
Japanese Patent Laid-Open No. 11-302580 JP-A-8-146560

  The present invention has been made in view of the above situation, and its purpose is to provide a support for a recording material from a recording material in which a coating film is formed using a natural polymer binder and a synthetic polymer binder on the support. An object of the present invention is to provide a method for recovering a support having good productivity and profitability in a state where it can be reused as a raw material.

  The above object of the present invention has been achieved by the following constitution.

(Claim 1)
After cutting the sheet-shaped recording material having at least one coating film on the polyester-based resin support into a chip-shaped recording material, treating with an alkaline processing liquid, and separating and removing the coating film from the chip-shaped recording material In the polyester resin support recovery method of recovering the polyester resin support,
Cutting the sheet-shaped recording material in a laminated state, and a cutting portion for cutting the chip-shaped recording material;
A processing section for processing the chip-shaped recording material with the alkaline processing liquid;
A first separation processing unit;
A second separation processing unit;
A neutralization processing section;
A method for recovering a polyester resin support, comprising using a recovery device having a washing / drying section.

(Claim 2)
The cutting section includes a first cutting device that cuts the laminated sheet-shaped recording material into strip-shaped recording materials, and a second cutting device that cuts the strip-shaped recording material into chip-shaped recording materials. The method for recovering a polyester resin support according to claim 1.

(Claim 3)
The polyester-based resin support recovery method according to claim 1 or 2, wherein the chip-shaped recording material is an indeterminate shape having an outer size of 0.1 to 100 mm.

(Claim 4)
The method for recovering a polyester resin support according to any one of claims 1 to 3, wherein the coating film uses a natural polymer binder or a synthetic polymer binder.

  From a recording material in which a coating film is formed by using a natural polymer binder and a synthetic polymer binder for the support, a support with good productivity and profitability in a state that it can be reused as a support material for recording materials. A recovery method can be provided, and the recovery rate of the support can be greatly improved while it can be reused as a raw material for the support for recording materials.

  Embodiments according to the present invention will be described with reference to FIGS. 1 to 4, but the present invention is not limited thereto.

  FIG. 1 is a schematic view showing an example of a method for recovering a support from a chip-shaped recording material.

  In the figure, 1 indicates a recovery device. The collection apparatus 1 uses the collected sheet-like recording material 9 as a laminated body 9a, cuts the laminated body 9a into a chip-like recording material, a processing unit 3 that performs processing with an alkaline processing liquid, The first separation processing unit 4, the second separation processing unit 5, the neutralization processing unit 6, and the water washing / drying unit 7 are provided.

  The cutting unit 2 uses the collected sheet-like recording material 9 as a laminated body 9a, a first cutting device 201 that cuts the laminated body 9a into strip-like recording materials 9b, and a strip-like recording material 9b as a laminated body 9c. And a second cutting device 202 for cutting the body 9c into the chip-shaped recording material 9d. Reference numeral 202a denotes a container for receiving the chip-shaped recording material 9d cut by the second cutting device 202. The first cutting device 201 and the second cutting device 202 will be described with reference to FIG.

  The chip-shaped recording material 9d is moved to the processing unit 3 in the next process. There is no particular limitation on the moving means. For example, it is possible to receive the conveyor belt and carry it directly to the processing section, and this figure shows a case where the processing section 3 is moved in a container. The moving means can be appropriately selected according to the processing amount. The size of the chip-shaped recording material is preferably an indeterminate shape having an outer size of 0.1 to 100 mm. The external size means a length twice the distance from the center (center of gravity) of the chip recording material to the vertex of the farthest corner. When the outer size is less than 0.1 mm, there is a risk of clogging the liquid feeding pipe depending on the thickness of each liquid feeding pipe of the recovery device shown in FIG. Similarly, when the length exceeds 100 mm, there is a risk of clogging of the liquid feeding pipe depending on the thickness of each liquid feeding pipe of the recovery apparatus shown in FIG. In addition, there is a case where stirring cannot be sufficiently performed in the cleaning process of the next process, or the sludge adhering to the chip and the re-adhered coating film remain due to insufficient cleaning. In addition, the coating film may partially remain without being uniformly stirred in the alkali treatment.

  Reference numeral 3 denotes a processing unit for processing with an alkaline processing liquid. 301, the chip-shaped recording material 9 d having a coating film on the support is heat-treated with stirring with an alkaline processing liquid 303 containing sodium hydroxide or potassium hydroxide to peel the coating film from the support. A processing device is shown. The processing apparatus 301 has a processing tank 301a and a stirring blade 301b. The shredded chip-shaped recording material 9d includes waste objects generated in the manufacturing process (for example, production scraps, defective products generated in the product inspection process, etc.), used products, and products collected from the market. It is done.

  As processing conditions by the processing apparatus 301, the solid content concentration in an alkaline processing liquid is 0.1-30 mass%, the density | concentration of an alkaline processing liquid is 0.01-4 mol / L, temperature is 70-95 degreeC, time. It is preferable to process for 10 to 120 minutes.

  When the solid content concentration in the alkaline processing liquid is less than 0.1% by mass, the energy efficiency of ultrasonic vibration is poor and productivity may be deteriorated. When the solid content concentration exceeds 30% by mass, it is difficult to agitate the chip-shaped recording material, the shearing force due to the collision between the chip-shaped recording materials cannot be applied, and the chip-shaped recording material that remains without peeling off the coating film. May increase.

  When the alkaline concentration of the alkaline processing liquid is less than 0.01 mol / L, it is difficult to peel off the coating film from the chip-shaped recording material, the processing time may be long, and the remaining coating film may increase. . When the alkali concentration exceeds 4 mol / L, hydrolysis of the support proceeds, the physicochemical characteristics of the support change, and it may not be reusable as a raw material for recording materials.

  When the temperature of the alkaline processing liquid is less than 70 ° C., depending on the type of coating film, it may take time to peel off, and it may not be completely peeled off, and may remain as impurities and cannot be reused as a recording material. There is. When the temperature exceeds 95 ° C., the support may be deteriorated and cannot be reused as a raw material as a recording material.

  When the time is less than 10 min, it may remain without being peeled depending on the type of the coating film, and may not be reusable as a raw material as a recording material. If the time exceeds 120 minutes, the support may be deteriorated and may not be reused as a raw material as a recording material.

  This figure shows a case where the alkali treatment of the chip-shaped recording material is performed by stirring with a stirring blade, but the method is not particularly limited, and for example, a method using ultrasonic vibration may be used.

  Reference numeral 4 denotes a first separation processing unit, which includes a hydrocyclone 401, a first collision type centrifugal dehydrator 402, and a draining means 403. There is no limitation in particular as the draining means 403, For example, an air cyclone, a screen conveyor, etc. are mentioned. In this figure, the case where an air cyclone is used is shown.

  Reference numeral 401 a denotes a hopper that receives solids separated from the alkaline processing liquid by the hydrocyclone 401. Commercially available hydrocyclone 401, first collision-type centrifugal dehydrator 402, and air cyclone 403 can all be used, and the size can be appropriately selected from the processing amount.

  The first separation processing unit is a step of separating solids from the alkaline processing liquid of the previous step. It is preferable that the alkaline processing liquid containing the solid matter from the processing unit 1 is introduced from the upper part of the cylindrical portion 401b of the hydrocyclone 401 at a speed of 10 to 2500 m / min in the circumferential tangential direction of the hydrocyclone. If it is less than 10 m / min, the generation of eddy currents in the hydrocyclone body is weakened, and separation may not be possible depending on the state of solids in the alkaline processing liquid sent from the processing unit 3. When it exceeds 2500 m / min, depending on the state of the solid in the alkaline processing liquid sent from the processing unit 3, the solid may clog the orifice 201 c below the hydrocyclone, and separation may not be possible.

  It is preferable to dilute the alkaline processing liquid with water so that the solid content concentration when introduced into the hydrocyclone 401 is 0.1 to 2% by mass. When the amount is less than 0.1% by mass, a large amount of water is used, which may be one of the causes of poor productivity. When the content exceeds 2% by mass, the hydrocyclone may be clogged depending on the size of the chip-shaped recording material.

  The alkaline treatment liquid introduced along the circumferential tangential direction of the hydrocyclone is separated and recovered by the centrifugal force into the hopper 401a from the orifice 401c via the tapered portion 401e of the hydrocyclone 401, and the upper portion is discharged. From the outlet 401d, the peeled coating film and the alkaline treatment liquid including a part of the generated sludge and the like are discharged.

  From these solids, in order to separate and remove the coating film and sludge reattached to the support, the separated coating film, sludge and the like, water is added from the hopper 401a, and the solid content concentration is in the range of 0.1 to 50% by mass. And is introduced from the lower part of the first collision type centrifugal dehydrator 402.

  While the solution introduced into the first collision type centrifugal dehydrator 402 moves to the upper part while colliding with each other, a part of the deposit and the peeled coating film, sludge and the like are discharged from the lower part 402a. From the upper portion 402b, the support (including the support from which the coating film has been peeled off, the support from which a part of the coating film remains, and the support to which the peeled coating film, sludge, and the like are attached) cannot be separated. The peeled coating film and the like remaining on are discharged.

  The support discharged from the upper portion 402b of the first collision type centrifugal dehydrator 402 (the support from which the coating film was peeled off, the support from which a part of the coating film was left, the peeled coating film, sludge, and the like adhered. In addition, the peeled coating film remaining without being separated is introduced into an air cyclone serving as a draining means, and the adhering water is removed.

  The solids collected at this stage were generated by the support from which the coating film was peeled off, the support from which a part of the coating film remained, the support from which the peeled coating film was reattached, and the alkaline processing liquid. Since the support to which sludge and the like are attached, the peeled coating film, and the sludge and the like generated by the alkaline processing liquid are mixed, it is not yet in a state where it can be reused for the support of the recording material.

  Reference numeral 5 denotes a second separation processing unit, which includes a high shear stirring device 501 and a second collision type centrifugal dehydrator 502. Commercially available high shear agitator 501 and second collision type centrifugal dehydrator 502 can both be used, and the size can be appropriately selected according to the processing amount.

  The second separation processing unit 5 is configured to peel the coating film and sludge from the support to which the separated coating film and sludge collected by the first separation processing unit are attached, and the peeled coating film. Is a step of separating the support by making it easy to subdivide and remove.

  The solid matter recovered by the first separation processing unit 4 is adjusted to a solid content concentration of 0.1 to 50% by mass with water and put into the high shear stirring device 501. The mechanism and processing conditions of the high shear stirring device 501 will be described with reference to FIG.

  The solid matter is processed by applying a high shearing force with the high shear stirring device 501, so that the coating film remaining on the support, the coating film, the sludge, and the like adhering to the support are separated and simultaneously subdivided. . Similarly, the peeled coating film, sludge and the like remaining without being separated are subdivided by being treated by applying a high shearing force to form a solution mixed with water.

  In this state, the support is separated from the coating film, sludge, and the like by being introduced into the second collision type centrifugal dehydrator 502 and processed, and the support is recovered. When the support is recovered from the second collision type centrifugal dehydrator 502, it may be recovered via an air cyclone as shown in the first separation processing unit. Since the support recovered at this stage contains a support with a small amount of coating film, sludge, etc., and a subdivided coating film, etc., it is still reused as a recording material support. It is not in a state where it can be done. The mechanism and conditions of the second collision type centrifugal dehydrator 502 will be described with reference to FIG.

  Reference numeral 6 denotes a neutralization processing unit that makes the support recovered from the second separation processing unit 5 reusable as a recording material support. Reference numeral 601 processes the support while stirring the support 602 collected from the second collision type centrifugal dehydrator 502 in the treatment tank 601a with the stirrer 601b with the acidic treatment liquid 603 at a temperature of 1 to 95 ° C. A processing device is shown. By the treatment with the acidic treatment liquid, a slight coating film, sludge, and a fine coating film binder adhering to the support 602 are decomposed, and silver can be separated and removed as silver nitrate. .

  The support recovered at the stage where the treatment with the acidic processing liquid is completed has no adhesion of foreign matter, and is separated from the acidic processing liquid by the same level as the support used in the production of the recording material. It is in a state that can be reused for the support.

  The acidic treatment solution used in the neutralization treatment section is not particularly limited, and examples thereof include nitric acid, hydrohalic acid, sulfuric acid and the like, and nitric acid and hydrohalic acid are particularly preferable. The concentration of the acidic treatment liquid is preferably 0.01 to 10 mol / L. When it is less than 0.01 mol / L, the binder of the coating film may not be decomposed depending on the type of binder, and silver may not be eluted into the solution. If it exceeds 10 mol / L, depending on the material used in the equipment, corrosion may progress and hinder production.

  Reference numeral 7 denotes a washing / drying section. The water washing / drying unit 7 is a step in which the support treated with the acidic processing solution in the neutralization processing unit 6 is separated, washed with water, and dried so that it can be reused as a raw material for the support of the photographic photosensitive material.

  Reference numeral 701 denotes a water washing apparatus, and reference numeral 702 denotes a drying apparatus. The washing device 701 is not particularly limited as long as the recovered support can be washed efficiently. For example, the washing device 701 may be washed with a shower on a mesh belt or may be a washing tank with a stirrer. A mesh drum type container that can be rotated while the washing water is cut off in the shower may be used. This figure has shown the case where flushing water is applied by a shower on a mesh belt.

  The drying device 702 is not particularly limited as long as the drying device 702 can dry efficiently as in the case of the water washing device 701. For example, drying air may be blown on a mesh belt, or a mesh drum that can be rotated while blowing drying air. A type container may be used. This figure shows the case of drying by blowing dry air on a mesh belt. When the drying is completed, the recovery of the support in a state where it can be reused as the raw material for the support of the photographic photosensitive material is completed.

  As shown in FIG. 1, the separation shredding unit, the processing unit using the alkaline processing liquid, the first separation processing unit, the second separation processing unit, the neutralization processing unit, and the water washing / drying unit may be performed in a continuous mode or a batch processing mode. It is possible to select appropriately according to the amount of treatment.

  FIG. 2 is a schematic perspective view of the first cutting device and the second cutting device of the cutting unit shown in FIG. FIG. 2A is a schematic perspective view of the first cutting device. FIG. 2B is a schematic perspective view of the second cutting device.

  The first cutting device 201 includes a mounting table 201c on which the collected sheet-like recording material 9 is mounted, a suction plate 201a (201b) disposed on the mounting table 201c, a pressing plate 201d, a cutting blade 201e, Storage container 201f. The suction plate 201a (201b) can be moved in the direction of the arrow in the drawing in accordance with the width of the sheet-like recording material 9. The suction plate 201a (201b) has a plurality of suction holes on the inside, and has a suction tube 201a1 (201b1) connected to a vacuum pump (not shown) provided in the suction plate 201a (201b). Yes. The push plate 201d can be pushed out via the push shaft 201d1 by an air cylinder, a hydraulic cylinder, a ball screw, or the like in accordance with the width of cutting the laminated body 9a with the cutting blade 201e (in the arrow direction in the figure). Next, a method for cutting the laminate 9a into strips using the first cutting device 201 will be described.

  As a first stage, the sheet-like recording material 9 is stacked and placed between the suction plates 201a (201b) of the placing table.

As the second stage, the suction plate 201a (201b) is moved according to the width of the stacked recording material 9 and then sucked by a vacuum pump (not shown) to be stacked and mounted. The air between the recording materials 9 is removed, and a laminate 9a is completed.
As a third stage, the laminated body 9a is pushed out to the position of the cutting blade 201e in accordance with the width to be cut by the pressing plate 201d.

  As a third stage, the laminated body 9a is cut into strip-shaped recording material 9b by the cutting blade 201e and stored in the storage container 201f. The inner dimension of the storage container 201f is preferably matched to the dimension of the strip-shaped recording material 9b, and the state of the strip-shaped recording material 9b stored in the storage container 201f is a state in which the strip-shaped recording material 9b is stacked. Yes.

  The second cutting device 202 includes a mounting table 202b for stacking and mounting the strip-shaped recording materials 9b, a suction plate 202c (202d) disposed on the mounting table 202b, a pressing plate 202e, a cutting blade 202f, and a storage. And a container 202a. The suction plate 202c (202d) can be moved (in the direction of the arrow in the figure) according to the width of the stacked strip-shaped recording material 9b. This figure shows a case where ten strip-shaped recording materials 9b are stacked side by side. The suction plate 202c (202d) has a plurality of suction holes on the inside, and has a suction tube 202c1 (202d1) connected to a vacuum pump (not shown) provided on the suction plate 202c (202d). Yes. The push plate 202e can be pushed out through the push shaft 202e1 by an air cylinder, a hydraulic cylinder, a ball screw, or the like in accordance with the width of cutting the strip-shaped recording material 9b with the cutting blade 202f (in the direction of the arrow in the figure). It has become. Next, a method of cutting the laminate 9c into chips using the second cutting device 202 will be described.

  As a first step, the strip-shaped recording material 9b cut by the first cutting device 201 and stored in the storage container is stacked and placed between the suction plates 202c (202db) of the mounting table. Assuming that a single strip-shaped recording material 9b is stacked as one block, it is possible to stack a plurality of strip-shaped recording materials 9b into a plurality of blocks.

As the second stage, the suction plate 202c (202d) is moved in accordance with the width of the plurality of blocks of the strip-shaped recording material 9b stacked and placed, and then is stacked and placed by suction with a vacuum pump (not shown). The air between the plurality of blocks of the strip-shaped recording material 9b is removed, and a laminate 9c is completed.
As a third stage, the laminated body 9c is pushed out to the position of the cutting blade 202f in accordance with the width to be cut by the pressing plate 202e.

  As a third stage, the laminated body 9c is cut into the chip-shaped recording material 9d by the cutting blade 202f and stored in the storage container 202a.

  There are no particular limitations on the method for producing the sheet-shaped recording material 9 aggregate 9a and the strip-shaped recording material 9b aggregate 9c. For example, a method of solidifying with liquid nitrogen, liquid oxygen, dry ice, or the like is also possible. Further, there is no particular limitation on the method for cutting the integrated body 9a and the integrated body 9c. For example, an ultrasonic cutter, sand blast, ice blast, or the like can be used.

As shown in the figure, the following effects can be obtained by forming the sheet-shaped recording material into an integrated body and then cutting the chip-shaped recording material.
1) Since the shearing stress at the time of cutting is dispersed, it is possible to produce a chip-shaped recording material that prevents the occurrence of cracks and cracks.
2) Since the occurrence of cracks and cracks in the chip-shaped recording material is prevented, sludge generated by the alkali treatment, the peeled coating film, etc. do not enter the cracks or cracks of the support from which the coating film has been peeled off. The post-treatment process is facilitated, and a highly pure support can be recovered.
3) Since the sizes of the chip-shaped recording materials can be made uniform, the uniform coating film can be peeled off by alkali treatment, the post-treatment process is facilitated, and the support with high purity can be recovered.
4) Since the shearing force of the corner is not applied to the cutting blade, the life of the cutting blade can be extended.

  FIG. 3 is a schematic view of a Henschel mixer, which is a high shear stirring device of the second separation processing unit of FIG. FIG. 3A is a schematic cross-sectional view of a Henschel mixer. FIG. 3B is a schematic perspective view of the lower blade of the Henschel mixer. FIG. 3C is a schematic perspective view of the upper blade of the Henschel mixer.

  In order to recover only the support from the solids recovered by the first separation processing unit, a high shear force is applied to these to apply a coating film remaining on the support, a coating film adhering to the support, and sludge. As a result of the examination, it has become clear that it is most effective to peel off and remove the coating film and the like, and to subdivide and remove the mixed coating film.

  Since the coating film remaining on the support is in a state where the alkaline solution is infiltrated into the undercoat layer when the treatment with the alkaline solution is completed, peeling is easily promoted by applying a high shear force to the coating film. It is in a state. Moreover, peeling is promoted by applying a high shearing force to the coating film, sludge and the like adhering to the support. The peeled coating film, sludge and the like are subdivided by applying a high shearing force, and are easily separated from the support in the next step.

  A Henschel mixer (manufactured by Mitsui Mining Co., Ltd.) can be cited as an optimal apparatus that applies a high shear force evenly. In this figure, a case where a Henschel mixer is used as a high shear stirring device will be described.

  In the figure, 301a represents a bottomed cylindrical body of the Henschel mixer, and 301b represents a lid. 301c shows a rotating shaft, 301d shows the lower blade | wing attached to the rotating shaft 31c, 301e shows the upper blade | wing attached to the rotating shaft 301c. As the rotating shaft rotates (in the direction of the arrow in the figure), the liquid in the body 301a generates a flow in two directions. One is the upward flow from the bottom (in the direction of the arrow in the figure) due to the rotation of the lower blade 301d. The other is a horizontal flow (in the direction of the arrow in the figure) generated by the rotation of the upper blade 301e. When solids are present in the processing liquid, the solids are once subjected to an upward flow, and then are subjected to a downward flow and contact with the upper blade to be subjected to a shearing force. By applying a high shearing force uniformly to each solid matter by processing for a certain period of time with a Henschel mixer that generates such a flow, the coating film remaining on the support, the coating film and sludge that had adhered, When the coating film remaining without being separated is peeled off, it is shredded and subdivided to facilitate separation in the next step.

  The shape of the lower blade and the upper blade is not particularly limited, and can be appropriately selected depending on the type of the object to be stirred and the concentration of the solid material.

  Preferred conditions in the Henschel mixer 301 include the following conditions. The solid content concentration is preferably 1 to 70% by mass. When the amount is less than 1% by mass, the swirl flow in the tank becomes dominant, the axial flow is not generated, and the pulverization by the upper blade may not be possible depending on the kind of the object to be stirred and the kind of the solid substance. If it exceeds 70% by mass, depending on the type of solid matter, bridging is likely to occur and uniform stirring may not be possible.

  The rotation speed of the blade (the peripheral speed at the tip of the blade) is preferably 10 to 70 m / sec. If it is less than 20 m / sec, the shearing force applied to each solid matter becomes small, and depending on the state of the applied coating film and sludge, it may not be peeled off or the peeled coating film may not be fragmented. When it exceeds 70 m / sec, depending on the type of coating film, the temperature of the peeled coating film rises with stirring, and depending on the type of binder used in the coating film, the viscosity increases and softens and peels. The coating film may adhere to the support again, and it may be difficult to peel off the coating film that has been reattached in the subsequent steps.

  The time is preferably 10 to 30 minutes. If it is less than 10 minutes, the peeling may not be completed depending on the type of coating film and the state of adhering foreign matter. If it exceeds 30 minutes, the internal temperature rises and the viscosity increases and softens depending on the type of binder used in the coating, and the peeled coating adheres to the support again. It may be difficult to peel off the attached coating film.

  The temperature is preferably 1 to 40 ° C. When the temperature is lower than 1 ° C., depending on the type of contents, solidification may occur partially and complete flow may not be possible. When it exceeds 40 ° C., depending on the type of coating film, it may start to become viscous and reattach to the support.

  FIG. 4 is a schematic view of the second collision type centrifugal dehydrator shown in FIG. FIG. 4A is a schematic sectional view of the second collision type centrifugal dehydrator shown in FIG. FIG. 4B is a schematic plan view of a collision type centrifugal dehydrator.

  In the figure, 302a indicates a cylindrical outer cylinder of a collision type centrifugal dehydrator, and 302b indicates a rotating rotor disposed inside the outer cylinder 302a. 302c shows a cylindrical separation cylinder. Reference numeral 302d denotes a motor for driving the rotary rotor 302b. Reference numeral 302c1 denotes a hole provided in the cylindrical separation cylinder 302c. Reference numeral 302b1 denotes a stirring blade attached to the surface of the rotating rotor 302b. When the rotary rotor 302b is rotated (in the direction of the arrow in the figure), the stirring blade is fed with the processing liquid processed by the high shear stirring device inserted from the supply port 304 into the gap 303 between the separation cylinder 302c and the outside of the rotary rotor 302b. It is attached at an angle that results in upward flow. Centrifugal force is applied by rotating the rotating rotor 302b, and the coating film, sludge and treatment liquid peeled off from the support are removed from the holes provided in the separation cylinder 302c, and the support is not passed through the remaining upper portion. Is discharged and separated from the outlet 305 of the printer. The coating film and the treatment liquid mixed with the adhering material that have passed through the holes are discharged from the discharge port 306 at the lower part of the outer cylinder 302a. The size of the hole 302c1 is preferably 1/10 to 1/2 of the size of the chopped chip-shaped photographic material. If it is less than 1/10, depending on the size of the peeled coating film and the size of the deposit, it may not be removed without passing through the hole. When the ratio exceeds 1/2, the support may be removed depending on the size of the support. The size of the chopped chip-shaped photographic photosensitive material means an average value obtained by measuring 100 g of the chopped chip-shaped photographic photosensitive material and measuring the maximum length of each chip. The shape of the hole 302c1 is not particularly limited, but a circular shape is preferable from the viewpoints of cleaning the separation cylinder, maintaining strength, and making it easily.

  The aperture ratio of the holes 302c1 provided in the separation cylinder 302c (the total area of the holes / total surface area of the separation cylinder × 100) is preferably 10 to 80%. Furthermore, 30 to 60% is preferable. If it is less than 10%, depending on the concentration of solids in the treatment liquid, it may take time to separate, and work efficiency may deteriorate. If it exceeds 80%, the strength may be insufficient depending on the material of the separation cylinder, and it may take time and cost for maintenance of the separation cylinder, resulting in poor production efficiency.

  The shape of the rotating rotor 302b is not particularly limited as long as it can rotate at high speed, and may be, for example, a cylindrical shape or a polygonal cylindrical shape. This figure shows a cylindrical shape. The first collision type centrifugal dehydrator used in the first separation processing unit has the same structure as the second collision type centrifugal dehydrator shown in the figure.

  The amount of the processing liquid to be put into the collision type centrifugal dehydrator can be appropriately determined depending on the solid content concentration and the size of the collision type centrifugal dehydrator. The rotational speed (circumferential speed) of the rotating rotor is preferably 5 to 40 m / sec. In the case of less than 5 m / sec, the size of the support on which a part of the coating film in the treatment liquid remains, the peeled coating film, sludge generated by the alkaline treatment liquid treatment, and the peeled coating film are attached. Depending on the situation, solids do not roll up in the collision type centrifugal dehydrator, there is no collision between these supports, and sludge generated by the coating film and alkaline treatment liquid treatment may not be separated. If it exceeds 40 m / sec, the support is damaged by the blades of the rotor and miniaturization proceeds, so depending on the size of the hole provided in the separation cylinder, the refined support is removed and the recovery rate is greatly increased. May fall.

  The sheet-like recording material collected and laminated as shown in FIG. 2 is cut into chips, and the support is recovered from the recording material using the recovery device shown in FIGS. The following effects can be obtained.

  1) When a sheet-shaped recording material is cut into a chip-shaped recording material, a chip that does not generate fine cracks, cracks, or in-layer destruction of the support is produced at the peripheral edge, and thus a peeled coating film is generated. As a result, it is possible to prevent the sludge and the like from being mixed, so that the purity of the recovered support becomes high, and the utility value can be improved as a raw material of the recording material.

  2) Since cutting is performed in a laminated state, a large amount of processing is possible, and work efficiency can be improved.

  The support according to the present invention is not particularly limited. The thing of description is mentioned.

  The recording material using the support according to the present invention can be any recording material in which a coating film is formed using a natural polymer binder and a synthetic polymer binder. Examples of the recording material using the natural polymer binder include medical, printing and general silver halide photographic light-sensitive materials.

  Examples of the recording material using the synthetic polymer binder applied to the polyester resin support recovery method of the present invention include a photothermographic material and a radiation image conversion sheet. In particular, JP-A-9-292671, JP-A-9-304870, JP-A-9-304871, JP-A-9-304882, JP-A-10-31282, JP-A-10-62898, JP-A-11-295844, and JP-A-11 The photothermographic material disclosed in Japanese Patent No. -352627 is preferred.

  In the present invention, examples of the transparent or translucent natural polymer and synthetic polymer binder used for the coating film formed on the support include the following. Examples of natural polymer binders include: gelatin, gum arabic, casein, starch and the like. Examples of synthetic polymer binders include: polyvinyl alcohol, hydroxyethyl cellulose, cellulose acetate, cellulose acetate butyrate, polyvinyl pyrrolidone, polyacrylic acid, polymethyl methacrylic acid, polyvinyl chloride, polymethacrylic acid, styrene-maleic anhydride copolymer , Styrene-acrylonitrile copolymers, styrene-butadiene copolymers, polyvinyl acetals (eg, polyvinyl formal and polyvinyl butyral), polyesters, polyurethanes, phenoxy resins, polyvinylidene chloride, polyepoxides, polycarbonates, polyvinyl acetate, Cellulose esters and polyamides are widely used.

  As a binder used for a coating film, any of a hydrophobic resin and a hydrophilic resin may be used, and they are properly used according to their suitability.

  Preferable hydrophobic resins include polyvinyl butyral resin, cellulose acetate resin, cellulose acetate butyrate resin, polyester resin, polycarbonate resin, polyacrylic resin, polyurethane resin, and vinyl chloride resin.

  Hereinafter, although an example is given and the concrete effect of the present invention is shown, the mode of the present invention is not limited to this.

Example 1
<Recovery of support>
Processing was sequentially performed according to the method shown in FIG.

<Preparation of chip-shaped recording material>
Prepare 1000 sheets of sheet-like recording material (SD-P (photothermographic material) manufactured by Konica Minolta MG Co., Ltd.) and use the cutting unit shown in FIG. 1 (first cutting device and second cutting device shown in FIG. 2). It was cut into 10 mm × 10 mm (outer size 14 mm) to produce a chip-shaped recording material, which was designated as 1-1. For comparison, the same sheet-shaped recording material was cut into an outer size of 14 mm by a commercially available crusher to produce a chip-shaped recording material, which was designated as 1-2.

(Setting of processing conditions with alkaline processing liquid)
A cylindrical treatment tank having a diameter of 30 cm and a height of 50 cm was prepared, and a sodium hydroxide solution having a concentration of 1 mol / L was used as the alkaline treatment liquid. Stirring was performed with a stirring blade, the solid concentration of the treatment tank was 10%, the treatment temperature was 90 ° C., and the treatment time was 60 minutes.
(Recovery of support)
After the treatment of the alkaline treatment liquid is completed, the alkaline treatment liquid is separated, and the remaining solids (the support from which the coating film has been peeled off, the support in which the coating film remains partially, and the treatment of the alkaline treatment liquid are used. 1 including the sludge generated, the support on which the peeled coating film and the like are reattached) by the water separation means, the second separation treatment section, the neutralization treatment section, and the water washing / drying section of the first separation treatment section shown in FIG. The support was recovered after treatment, and Samples 101 and 102 were obtained.

(Separation of moisture and other deposits by the first collision type centrifugal dehydrator of the first separation unit)
Water is further added to the solid material separated by the wet specific gravity separator to adjust the solid content concentration to 50% by mass. From the lower part of the first collision type centrifugal dehydrator shown in FIGS. 1 and 4, the flow rate is 5 m / min. The liquid mixture was introduced at a speed to separate a part of the unwanted matter. The first impingement type centrifugal dehydrator used has an outer cylinder diameter of 0.4 m, a height of 1.5 m, and a rotating rotor with a diameter of 0.3 m and a diameter of 1.5 m. ) Was performed at 15 m / sec. The separation cylinder has a circular hole with a diameter of 2 mm (about 1/5 of the size (outside size) of the chip-shaped SD-P) arranged in a plover shape at intervals of 3 mm, and has an opening rate of 40%. It was used.
(Separation of moisture and other deposits by air cyclone)
From the upper part of the first collision type centrifugal dehydrator, the solid matter discharged was separated from the adhering moisture and other adhering matter by an air cyclone.

<Separation of coating film, sludge, etc. from solids by the second separation processing unit>
In order to remove the coating film remaining on the support, the adhering sludge and coating film, the separated coating film remaining without separation, and the like from the solid separated by the first separation processing unit. The process by the 2nd separation process part shown by 1 was performed.

(Mixing with high shear stirrer)
A Henschel mixer (FM20C / L manufactured by Mitsui Mining Co., Ltd., the upper blade is Yi blade, and the lower blade is So blade) was used as the high shear stirring device. In order to process the separated solid matter with the Henschel mixer shown in FIGS. 1 and 6, water was added to adjust the solid content concentration to 50% by mass. The treatment liquid thus prepared was treated with a Henschel mixer at a blade rotation speed (peripheral speed at the tip of the blade) of 40 m / sec and a temperature of 30 ° C. for 10 minutes.

(Separation by the second collision type centrifugal dehydrator)
The mixed liquid mixed by the Henschel mixer was introduced from the lower part of the second collision type centrifugal dehydrator shown in FIG. 1 at a flow rate of 5 m / min to separate the support from the solid. The second collision type centrifugal dehydrator used was the same as the first collision type centrifugal dehydrator shown in FIG. 4 and was processed under the same conditions.

(Treatment by the neutralization section)
In the neutralization tank as shown in FIG. 1, sulfuric acid with a concentration of 0.5 mol / L was used as the treatment liquid, and the solid content concentration was 10%.
(Washing and drying)
As shown in FIG. 1, washing with water was carried out in a belt type, and was performed in a shower at a water amount of 100 L / min and a conveyance speed of 10 m / min. As shown in FIG. 1, the drying was carried out by a belt type conveyance at a temperature of 70 ° C. and a drying air volume of 100 m ³ / min.

(Evaluation)
Table 1 shows the results obtained by performing molecular weight measurement, coloring degree measurement, and foreign matter adhesion observation on each of the obtained samples 101 and 102 and evaluating according to the following evaluation rank. The molecular weight was measured using a viscosity measuring device SS-270LC-1 manufactured by Shibayama Scientific Machinery Co., Ltd. and converted from the obtained viscosity. For the coloring degree measurement, each sample was used, and a 0.5 mm thick plate was prepared using an injection molding machine AU3E manufactured by Nissei Plastic Industry Co., Ltd. Each plate was measured using a spectrophotometer U-3210 manufactured by Hitachi, Ltd.

Evaluation rank of molecular weight ○: Difference from the reference sample is less than 10% Δ: Difference from the reference sample is less than 10 to 30% ×: Difference from the reference sample is 30% or more Note that the reference sample used for the evaluation is immediately after film formation The support was used.

Evaluation rank of coloring degree ○: The difference with respect to the reference sample is less than 3% △: The difference with respect to the reference sample is less than 3-5% ×: The difference with respect to the reference sample is 5% or more Immediately after the support was chopped, a product with a 0.5 mm thick plate was used using an injection molding machine AU3E manufactured by Nissei Plastic Industry Co., Ltd. in the same manner as each sample.

Observation of foreign matter 10 g of each sample 101 and 102 was arbitrarily sampled and visually checked for the presence or absence of foreign matter.

Evaluation rank of foreign matter adhesion ○: No foreign matter adhesion is observed on all the collected supports Δ: One to four foreign matters having a diameter of about 0.1 mm are attached to one of the collected supports × : Five or more foreign matters having a diameter of about 0.1 mm are attached to one of the collected supports.

  From the above results, it was confirmed that a support having the same purity as that of PET before use was recovered, and the effectiveness of the present invention was confirmed.

It is a schematic diagram which shows an example of the collection method of a support body from a chip-form recording material. It is a schematic perspective view of the 1st cutting device and 2nd cutting device of the cutting part shown in FIG. It is the schematic of the Henschel mixer which is a high shear stirring apparatus of the 2nd separation process part of FIG. It is the schematic of the 2nd collision type centrifugal dehydrator shown in FIG. It is a schematic sectional drawing of a photographic photosensitive material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Collecting apparatus 2 Cutting part 201 1st cutting apparatus 201a, 201b, 202c, 202d Suction plate 201c, 202b Placement table 201d, 202e Press plate 201e, 202f Cutting blade 202 2nd cutting apparatus 3 Processing part 301, 601 Processing apparatus 4 1st 1 separation processing unit 401 hydrocyclone 402 first collision type centrifugal dehydrator 5 second separation processing unit 501 high shear stirring device 502 second collision type centrifugal dehydrator 6 neutralization processing unit 7 water washing / drying unit 70 1 water washing device 702 drying Device 8 Photosensitive material 8a Polyester resin support 8b, 8c Undercoat layer 8d Photosensitive layer 8e Protective layer 8f Backing layer 9 Sheet-like recording material 9a, 9c Laminate 9b Strip-like recording material 9d Chip-like recording material

Claims (4)

After cutting the sheet-shaped recording material having at least one coating film on the polyester-based resin support into a chip-shaped recording material, treating with an alkaline processing liquid, and separating and removing the coating film from the chip-shaped recording material In the polyester resin support recovery method of recovering the polyester resin support,
Cutting the sheet-shaped recording material in a laminated state, and a cutting portion for cutting the chip-shaped recording material;
A processing section for processing the chip-shaped recording material with the alkaline processing liquid;
A first separation processing unit;
A second separation processing unit;
A neutralization processing section;
A method for recovering a polyester resin support, comprising using a recovery device having a washing / drying section. The cutting section includes a first cutting device that cuts the laminated sheet-shaped recording material into strip-shaped recording materials, and a second cutting device that cuts the strip-shaped recording material into chip-shaped recording materials. The method for recovering a polyester resin support according to claim 1. The polyester-based resin support recovery method according to claim 1 or 2, wherein the chip-shaped recording material is an indeterminate shape having an outer size of 0.1 to 100 mm. The method for recovering a polyester resin support according to any one of claims 1 to 3, wherein the coating film uses a natural polymer binder or a synthetic polymer binder.

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