JP3270037B2 - Collection method for synthetic resin substrates - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved method for recovering a synthetic resin or the like from a product having a recording layer or the like provided on a substrate made of a synthetic resin or the like.

[0002]

2. Description of the Related Art In many fields, materials obtained by laminating layers having various functions on a substrate made of a synthetic resin or a cellulose organic acid ester are used. For example, various recording materials in which a recording layer or the like is laminated on a substrate such as cellulose triacetate, polyethylene terephthalate, and polycarbonate are widely used. These recording materials include a photographic photosensitive material provided with a silver halide photosensitive layer, and a CD-RO provided with a dye recording layer and a reflective layer on a PMMA or polycarbonate substrate.
M, CD-R, DVD, DVD-R and the like.

An example of a method for recovering a polycarbonate resin from an optical disk product is disclosed in JP-A-4-360.
No. 035 (Japanese Patent No. 2615277), and a disk product having an aluminum reflective film is used for 75 to 10 times.
It is known to treat at 0 ° C. in a concentrated alkaline aqueous solution. Further, Japanese Patent Application Laid-Open No. 5-345321 describes a method in which a plastic molded article having a metal vapor-deposited film is heated in hot water at 70 ° C. or higher to peel off the vapor-deposited film.

[0004]

The problem to be solved by the present invention is, first, a substrate made of a synthetic resin or a cellulose organic acid ester (hereinafter also referred to as "synthetic resin or the like"), particularly a polycarbonate-based material. Material and polyester base material with high quality that can be reused for the original purpose, and
An object of the present invention is to provide a collection method capable of stably collecting a large amount at a low collection cost.

[0005]

The above objects of the present invention are as follows.
This was achieved by the following means. According to a first aspect of the present invention,
After removing a foreign layer provided on the substrate from a substrate made of a synthetic resin in an alkaline aqueous solution at 105 ° C. or higher,
Water containing 0.1% to 10% by weight of peroxide
The present invention relates to a method for removing a foreign layer, which is characterized by treating with a solution . As the above synthetic resin, aromatic polycarbonate, aromatic polyester or polypyromellitimide is preferable, bisphenol A polycarbonate,
Polyethylene terephthalate or polyethylene naphthalate is particularly preferred. Cellulose organic acid esters , eg
For example, the present invention can be applied to cellulose acetate, cellulose acetate butyrate, or cellulose acetate propionate.

A second aspect of the present invention, a product having a heterogeneous layer on the polycarbonate substrate, after removing the layer of the heterogeneous in an alkaline aqueous solution above 105 ° C., 0.1 mass
% To 10% by weight of an aqueous solution containing a peroxide . In the present invention, a polycarbonate substrate provided with at least one functional layer selected from the group consisting of a dye-containing layer, a metal reflective layer, a photosensitive layer, a protective layer, an undercoat layer , and an adhesive layer on the polycarbonate substrate A step of substantially removing the functional layer in an alkaline aqueous solution having a pH of 10 to 14 and 105 ° C. to 130 ° C.
It is preferred to include . Furthermore, 0.1 mass% to 20 mass%
Wt% caustic and 0.001 wt% to 10 wt%
A step of removing the functional layer from the polycarbonate substrate while stirring in an aqueous alkaline solution containing not more than 10% by mass of a surfactant, followed by a step of removing the aqueous alkaline solution, the recovery of the above-mentioned polycarbonate substrate The method can be preferably used. In the above-described method for recovering a polycarbonate substrate, the step of removing the functional layer with an aqueous alkali solution may be performed at least two times with a fresh aqueous alkali solution.

[0007] A third aspect of the present invention is a photographic polyester.
The functional layer provided on Rufirumu, 105 ° C. to 150 DEG
The present invention relates to a method for recovering a photographic polyester film , comprising a washing step of removing the polyester film in an aqueous alkali solution at ℃ . Further, in the method for collecting a photographic polyester film , the method further includes a functional layer containing silver or silver halide.
In the step of removing the functional layer from the photographic polyester film in an alkaline aqueous solution, a negative electrode is inserted into the alkaline aqueous solution, and sufficient to reduce silver ions in the alkaline aqueous solution and form silver plating on the negative electrode. A step of removing silver from the alkaline aqueous solution by applying a negative voltage to the negative electrode can be included. Polyester for photo
A step of cutting a product having a functional layer on a film into chips as necessary and removing the product at a temperature of 105 ° C. to 150 ° C. in an alkaline aqueous solution having a concentration of 0.1 to 3% by mass. It is good also as a polyester recovery method.

Even if various recovery methods known in the prior art are used, a high-quality (no foreign substance is recognized and little depolymerization) synthetic resin which can be reused in a short time and at a low processing cost is obtained. Although it was difficult, the recovery method of the present invention was able to recover a high-quality synthetic resin base material that can be reused for the original purpose of use for the first time.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the recovery method of the present invention will be described in detail. ADVANTAGE OF THE INVENTION According to the collection | recovery method of this invention, the foreign layer laminated | stacked on the base material and the attached foreign material can be selectively removed using the hydrophobicity and chemical resistance of the base material which consists of a synthetic resin etc. Since a substrate made of a synthetic resin or the like has an ester bond, a high concentration, for example, a sodium hydroxide solution of 7 to 30% by weight tends to be easily hydrolyzed when heated. The present inventors have found that when the concentration of the sodium hydroxide solution is reduced, the hydrophobicity of the synthetic resin or the like becomes more effective, and hydrolysis and dissolution can be almost completely avoided. In addition, the present inventor has surprisingly found that a heterogeneous layer (the heterogeneous layer may be a single layer or a plurality of layers) provided on a substrate made of a synthetic resin or the like. The rate-limiting step of removal was in the process of swelling of these layers, and it was found that swelling could be accelerated by lowering the alkali concentration. The present inventors further increase the temperature of the aqueous alkali solution to more than 100 ° C., preferably 105 to 150 ° C. (this is synonymous with 105 ° C. or more and 150 ° C. or less in the present invention) in accordance with the promotion of swelling. It has been found that foreign matter on a substrate made of resin or the like can be practically completely dissolved or completely peeled off.

The recovery method of the present invention can be widely applied to recovery of a thermoplastic resin. As the thermoplastic resin, synthetic resins and cellulose organic acid esters are typical, and cellulose organic acid esters represented by cellulose acetate, cellulose butyrate, or a mixed ester thereof; aromatic polyester, aromatic polycarbonate, polyimide And synthetic resins such as polyamides. Hereinafter, the aromatic polyester and the aromatic polycarbonate are simply referred to as polyester and polycarbonate.

The polycarbonate substrate product of the present invention is used for a disk base of a CD-ROM, a CD-R, a DVD, a DVD-R and the like, and has a vapor deposition layer and a coating layer on the surface. For this reason, the washing temperature with an alkaline aqueous solution is raised to about 105 ° C. or higher, and the concentration of caustic alkali is reduced, so that even in a short-time washing treatment, dyes and foreign substances on the substrate surface are almost completely removed, and the inside of the substrate is removed. Can be suppressed. Further, a method of changing the concentration of the caustic alkali in accordance with the progress of the removal of the foreign matter by the aqueous alkali solution, that is, an improvement such as adopting a multi-stage cleaning method using a fresh alkaline aqueous solution is also useful in the present invention. In the multi-step process, the number of steps in the process can be two to four.

[0012] Polycarbonate is a polycarbonate having a carbonate bond in the main chain, and is almost a non-crystalline linear polymer. It is preferable to use an aromatic polycarbonate, and bisphenol A obtained by reacting 2,2'-bis (4-hydroxyphenyl) propane (bisphenol A) with phosgene or diphenyl carbonate.
The use of polycarbonate is particularly preferred. JP-A-7-1
Other aromatic polycarbonate polymers described in US Pat. No. 6,597,78 can also be used in the present invention.

The functional layer provided on the polycarbonate substrate to be recovered is a layer having one or more functions useful as various recording materials, and includes a dye-containing layer, a metal reflective layer, a photosensitive layer, and a protective layer. And an undercoat layer. For the dye-containing layer, a cyanine-based dye or the like is widely used, and for the metal reflective layer, a vapor-deposited layer of gold, silver, or inexpensive aluminum having excellent reflection characteristics is frequently used. As the photosensitive layer, a silver halide emulsion layer or a non-silver salt photosensitive layer such as a photopolymer layer or a photosensitive diazo compound layer is used.

For the protective layer, the undercoat layer and the like, a copolymer of thermoplastic acrylic ester, acrylate monomer or methacrylate monomer having excellent optical properties is used. Further, the protective layer, benzophenone emission system as an ultraviolet absorber, benzotriazole-based, salicylic acid-based compounds such as phenyl salicylate is used, also UV curing agent is also used. As the undercoat layer, hardened gelatin, thermosetting resin, or the like can be used.

The polycarbonate substrate is used in the form of a plate or a film. For example, 50 or 2
It is used as a film having a thickness of 00 μm and a disk having a thickness of 0.5 to 2 mm. The diameter is often 12 cm.

Replacement of polyester base material recoverable in the present invention
The example in the table is used for the base film of photographic photosensitive material.
Polyester.Polyester film for photo
Is generally excellent in physical strength, water resistance and heat resistance.
Polyester film because its surface is hydrophobic
The base surface is first provided with a subbing layer, followed by a single layer or multiple layers.
After applying the hydrophilic layer, apply the hydrophilic photosensitive layer
There are many. Undercoat layer consisting of a single layer swells the surface of the substrate
Compound, water-soluble polymer, and polymer latex
Is often applied. Also, an undercoat consisting of multiple layers
The layer is vinylidene chloride, vinyl chloride, etc. as the first layer
And a second layer of gelatin
Hydrophilicity by applying a hydrophilic polymer such as
You. A hydrophilic photosensitive layer is provided on these undercoat layers,
It is firmly joined by a tin hardener. Arca of the present invention
Since aqueous solutions do not contain large amounts of water-soluble organic solvents,
Swells and removes the coated gelatin layer quickly, and is soluble in water after processing
Washing and removal of the liquid is also easy.

The polyester which can be recovered by the recovery method of the present invention has an ester bond, particularly a carboxylic acid ester bond in the main chain, and is almost a non-crystalline linear polymer.
Preferred examples include aromatic polyesters, and specific examples include polyethylene terephthalate, polyethylene naphthalate, and polypropylene terephthalate. Polyesters that can be used as a base material of a silver halide photographic light-sensitive material are described in JP-A-6-175285.

The typical film thickness of a photographic polyester film is 10 μm to 200 μm, and most is 80 μm.
To 180 μm.

Next, a method of recovering a substrate made of a synthetic resin or the like will be described. The recovery method of the present invention essentially requires a washing step of removing a foreign layer provided on a synthetic resin or the like, usually a functional layer having a specific function, in an alkaline aqueous solution. It includes a step of removing the resin from the resin or the like (usually referred to as a “rinsing step” for washing away with water) and a drying step.

(Cleaning treatment) In the preparation of the alkaline aqueous solution,
Caustic may be used, where "caustic" means hydroxides or carbonates of alkali metals, such as lithium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, and the like. Can be In addition to the caustic alkali, a surfactant and a peroxide may be used in combination as needed.

The washing step with an aqueous alkali solution in the present invention preferably uses an alkaline solution having a pH of 10 to 14. To adjust the pH, use a pH meter or p
Instead of the H meter, the adjustment can be made using a conductivity meter. The concentration of sodium hydroxide may be generally 0.1% by weight or more, but is preferably 0.1 to 20% by weight in the washing treatment of the polycarbonate substrate.
0.1 to 10% by weight is more preferred. Also for photos
In the washing treatment of the polyester film , 0.1 to 4% by weight is preferable, and 0.1 to 3% by weight is more preferable. If the pH can be adjusted to the same value, it is preferable to use a caustic having a low ionic strength.

The temperature of the washing step may be higher than about 105 ° C. In the treatment of a polycarbonate substrate,
105-130 ° C is preferred. Also, for photo
105-150 for steal film processing
C. is preferred, and 110 to 140 C. is more preferred.

In the cleaning treatment, substantially removing the functional layer means removing the functional layer from the substrate by 50% by weight or more.

The surfactant includes a nonionic surfactant, an anionic surfactant and a cationic surfactant. The surfactant used in the present invention includes a nonionic surfactant and an anionic surfactant. Agents are preferred. As the nonionic surfactant, for example, polyethylene glycol ethers, in particular, polyethylene glycol ethers of higher alcohols, polyethylene glycol ethers of alkylphenols and the like are preferably used.
Examples of the anionic surfactant include, for example, sodium alkylbenzenesulfonate, and are preferably used in combination with a nonionic surfactant. The concentration of the surfactant is 0.001 to 10% by weight, preferably 0.01 to 1% by weight. Surfactants are useful for removing dyes and minute foreign substances that have adhered to the product as a recovered raw material or have been removed and re-adhered to the processing solution.

The peroxide used in the present invention includes -O-
An oxide having an O-bond and an oxide of a metal having a multivalent valence are exemplified. Preferred are hydrogen peroxide and its salts, ozone, persulfuric acid and its salts, and the like. The concentration of the peroxide is preferably 0.1 to 10% by mass. The temperature of the aqueous peroxide solution is preferably from 65 to 95 ° C, more preferably from 80 to 90 ° C. Peroxide is useful for complete removal of residual metals and dyes. A 0.1% to 10% by mass solution of hydrogen peroxide has a pH of 2 to 5 (weakly acidic) and can be preferably used as a final washing solution.

In order to remove paints, dyes and the like, organic solvents, for example, poor solvents for the base material such as methanol, ethanol, isopropyl alcohol, glycerin and methyl solosolve can be used in combination.

The heating of the cleaning liquid is usually performed by using steam or hot water of 1 atm or more, a burner or electric heating. It is preferable to use a pressure type cleaning device, and it is preferable to use a high pressure resistant (0.2 to 0.5 MPa = 2 to 5 kgf / cm ² ) cleaning device. Washing time is 5 to 150
Minutes (5 minutes or more and 150 minutes or less), preferably 5 to 100 minutes, more preferably 10 to 60 minutes.

Further, the washing treatment with an aqueous alkali solution at 105 ° C. or higher can be carried out in two or more stages, preferably in two or three stages. An alkali washing step at 100 ° C. or lower may be added. After a short alkali cleaning step, a two-step alkali cleaning step of removing the adhered foreign substances by alkali cleaning is adopted, so that the reusable high quality can be achieved by a relatively short cleaning step. Can be recovered. In the treatment of two or more stages of caustic alkali, it is preferable to carry out the treatment while changing the alkali concentration, temperature or chip density of the aqueous alkali solution in each stage. During multiple alkaline cleaning steps,
If necessary, a draining or washing treatment can be performed.

When a substrate such as a synthetic resin provided with a silver-containing layer is treated with an alkaline aqueous solution, silver is dissolved in the slurry and silver-containing scale is generated on the wall surface of the treatment tank. Conventionally, use of a reducing compound such as a halide or a saccharide has been known to prevent this occurrence.

In the method of the present invention, a negative electrode is provided in the processing solution, and a negative voltage is set to about 1 to 10 volts, preferably 2 to 5 volts, so that silver can be collected and the wall of the processing tank or drainage can be performed. The adhesion of the silver-containing scale to the plate can be prevented.

In the treatment of a base material such as a synthetic resin according to the present invention, the base material to be treated is first selected, and the whole base material made of the synthetic resin or the like is cut into chips of an appropriate size in advance, and then the processing is performed. Preferably, it is applied. In the treatment of the polycarbonate substrate, it is preferable to crush to a size of 1 mm to 10 cm, more preferably to crush to a particle size of 1 mm to 10 mm. In the treatment of the polyester base material, it is preferable to crush to a size of 5 mm to 3 cm. It is preferable to use wet crushing for this crushing. For example, a method described in JP-A-7-286064 can be used.

(Washing treatment) The treatment for removing the aqueous alkali solution from the base material is called washing treatment. Specifically, in order to remove the processing solution or slurry from the chips that have been subjected to the caustic treatment, or to remove foreign substances that have dissolved or pulverized the undercoat layer and the upper layer, a process of washing with water is usually performed. Say. The treatment is preferably carried out using water at 10 to 60 ° C, more preferably 10 to 30 ° C. An acidic substance for alkali neutralization may be added to the washing water. After a caustic treatment or a washing treatment, an organic solvent, for example, alcohols such as ethanol and methanol, ketones such as acetone, and toluene and petroleum ether,
Further, it can be washed and dried with an aqueous solution containing these.

(Drying) The treated chip is heated to a temperature of 50 to 200 ° C., preferably 80 to 120 ° C., to reduce the water content to preferably 2% by mass or less, more preferably 1% by mass.
It refers to the process of drying until the temperature becomes below. In order to re-melt and produce regenerated pellets, it is preferable to dry under vacuum to reduce the water content to 0.2% by weight or less.

[0034]

EXAMPLES Examples will be shown below, but the present invention is not limited to these examples. Examples 1 and 2 show the recovery of polycarbonate, and Examples 11 to 15 show the recovery of polyester. (Example-1) Waste CD- using polycarbonate substrate
The R disk product was cut into a size of about 1 to 5 cm, and a polycarbonate substrate was recovered. The C
The DR disk product is made of a substrate (diameter 12 cm, thickness 1.2
mm), a protective film containing a dye film, a silver reflective film, an ultraviolet absorber and the like was provided. Through the processing of the next step,
After further washing with water and drying, the polycarbonate resin recovered sample N
o. 1 was obtained. (See Table 1 for processing conditions)

(First stage) Removal of adhering foreign matter at the time of cutting Mixing 1% by weight of each of a polyoxyethylene derivative (Emulgen A-500 manufactured by Kao Corporation) and sodium alkyl benzenesulfonate as a surfactant. The product is mixed with the aqueous solution at a solid to liquid ratio of 1: 1 at 90 ° C. for 60 hours.
The mixture was stirred for minutes. (Second Stage) Removal of Dye, Metal Film, and Protective Film (Part 1) A mixed aqueous solution of 1% by weight of nonionic surfactant of polyoxyethylene derivative and 3% by weight of sodium hydroxide (p
H13.5), and the product was treated at 120 ° C. for 30 minutes. (Third Stage) Removal of Dye, Metal Film, and Protective Film (Part 2) Following the second stage treatment, the sodium hydroxide concentration was set to 5% by mass, and the other conditions were exactly the same as the second stage treatment liquid composition and the like. 1
Treated at 20 ° C. for 30 minutes.

(Fourth step) Dissolution and removal of residual metal (silver) and washing A 1% by weight aqueous solution of each of a surfactant, a polyoxyethylene derivative and sodium alkylbenzenesulfonate (same as in the first step) , Hydrogen peroxide and 0.58% by mass of a mixed aqueous solution, and treated at 90 ° C. for 30 minutes. Further, it was washed with water and dried.

Evaluation of the quality (1) Degree of coloring of the chip-shaped collected sample (by visual judgment) 着色 Almost no coloring ○ Somewhat acceptable but below acceptable △ Acceptable × Acceptable, unusable (2) Average molecular weight by viscosity measurement Evaluation The average molecular weight of the virgin polycarbonate resin is 14,
500 ± 500. In this case, the allowable average molecular weight is 14,000 or more. 0.7 g of a sample is placed in dichloromethane 10
It was dissolved in 0 ml and the viscosity was measured at 20 ° C. (3) Visual determination of the presence or absence of foreign matter in a dichloromethane solution. No more than two virgin polycarbonate resins, especially 100 to 250 μm in diameter. Example-1
Collected material No. obtained in 1 was of usable quality. (1) Degree of coloring ◎ (2) Average molecular weight 14500 (3) Presence or absence of foreign matter Virgin resin or less

(Embodiment 2) In the embodiment 1, the second
The processing time of the third step was extended to 60 minutes only, and the processing of the third step was omitted.
o. 2 was obtained. In addition, the second-stage processing was omitted, and only the third-stage processing time was extended to 60 minutes. 3 was obtained. The result of the quality evaluation is sample N
o. 2 and sample no. The following three results were obtained. (1) The degree of coloring is the same as the sample No. As compared with 1, both were slightly inferior in “value ○”. Regarding the evaluations of (2) and (3), the others were sample Nos. It was equivalent to 1. The alkali high temperature treatment of the present invention is better divided into a plurality of stages,
It can be seen that foreign substances such as dyes are easily removed in the same processing time.

(Comparative Example 1) Using the same waste CD-R disc product cut as in Example 1, the concentration of sodium hydroxide, surfactant, treatment temperature and time were determined as shown in Table 1. Comparative samples A and B were obtained in the same manner except for setting. Table 1 shows the results of the quality evaluation.

[0040]

[Table 1]

The polycarbonate resin recovered sample no. 1,
Sample Nos. 2 and 3 are particularly good. 1 shows that the processing time can be shortened even with a small amount of the use of an alkaline substance, and that a high-quality recovered sample can be obtained with a reduced processing cost. The recovered sample can be reused together with the virgin resin.

(Embodiment 11) A polyethylene terephthalate film was used as a base film for a photographic light-sensitive material, and an undercoat layer using polyvinylidene chloride was provided thereon. A silver halide emulsion layer and a protective layer were formed on a film base. The semi-finished product (waste product) of the photosensitive material coated with
After being cut into chips corresponding to 5 to 3 cm square, they were used for the recovery treatment.

A pressurized washing apparatus having a cylindrical body with an inner diameter of about 45 cm, a hot water supply port provided with pressure resistance, and set to withstand 0.5 MPa against water vapor was used.

(First cleaning process) About 10 times of the above chip sample
kg into a processing container, 35 l of a hot aqueous solution of caustic soda set to a predetermined concentration (shown in Table 2) and 2.0 g of polyethylene glycol ether of higher alcohol (manufactured by Emulgen 106 Kao Corp.) were added. (Table 2
) For 15 minutes at about 100 rpm. The treatment liquid was discharged, the liquid was sufficiently drained, and a water washing treatment was performed for 5 minutes.

(Second Washing Treatment) To a chip sample subjected to the first caustic treatment, 30 l of a hot aqueous solution of caustic soda set to a predetermined concentration (shown in Table 2) and 10.0 g of polyethylene glycol ether of a higher alcohol were introduced. The mixture was stirred at a predetermined temperature (shown in Table 2) for 40 minutes at a rotation speed of about 200 rpm. Thereafter, the treatment liquid was discharged, and the liquid was sufficiently drained.

(Washing treatment) The mixture was stirred while pouring water, and washed with water for 10 minutes to remove foreign substances that had been removed from the membrane or finely divided.

(Drying treatment) The washed chips, which have been sufficiently drained, are taken out from the discharge port, and are dried at 100 ° C. for 30 to 6
Dried in 0 minutes.

(Preparation of Recycled Pellets or Recycled Films) The dried chips were vacuum-dried, and then heated and melted at 260 ° C. to 280 ° C. to obtain polyester films, which were cut to obtain regenerated pellets. The obtained film was biaxially stretched to obtain a regenerated film sample.

(Evaluation of Quality) (Confirmation of Removal of Undercoat Layer) When vinylidene chloride or the like was used for the dried chips, the presence or absence of organic (C atom) -bonded Cl atoms was examined by surface analysis using ESCA. (Confirmation of removal of undercoat layer) Also, the treated chip and a piece of standard polyethylene terephthalate film were immersed in a 1% sulfuric acid-containing indigo carmine aqueous solution, and the surface of the water was moved up and down to observe the wet state of the water. It was confirmed that the coating layer had been removed. A piece of film flips the water,
Even if one part of water adhered, it did not infiltrate. When a different organic compound such as a styrene-butadiene polymer was used for the undercoat layer of the dried chip, it was examined whether or not there was a different organic substance by surface analysis by ESCA (analysis of C _1S orbital spectrum).

(Confirmation of Foreign Material Removal from Reproduced Film) The presence of foreign materials was visually inspected through a magnifying lens (100 times) for the recycled film and the practical PET standard film, and the number of foreign materials in the reproduced film was compared with the standard film. , As follows: I: Somewhat less (practical) II: Equivalent (practical) III: More (impractical)

(Comparative Example-11) Using the same chip sample as used in Example-11, the first caustic treatment was carried out at a concentration of 4% by mass of caustic soda at a temperature of 85 ° C, and the second caustic treatment was carried out at a temperature of 85 ° C. Concentration 6% by mass, temperature 85 ° C
The other steps were the same as those used in Example 11 to obtain a sample A ′.

(Comparative Example 12: Example of Conventional Method) Using the same chip sample, the first caustic alkali treatment was carried out by stirring at a rotation speed of about 200 rpm for 20 minutes at a concentration of 4% by weight of caustic soda at a temperature of 85 ° C. And a water washing treatment for 50 minutes. Second
The caustic alkali treatment is performed by stirring at a rotation speed of about 200 rpm for 50 minutes at a temperature of 85 ° C. at a concentration of caustic soda of 6% by mass,
The washing process was performed for 50 minutes. Thereafter, the same operation as in Example 11 was performed to obtain a sample B ′. In the cleaning apparatus, a cathode plate made of stainless steel (SUS-304) is provided below the drain plate, and the processing container, particularly the drain plate, is provided with a cathode plate.
Each sample 1 was continuously processed by applying a negative voltage of volt. Adhesion of metallic silver (99% purity) was observed on the negative electrode, and needle-like silver could be collected on a Saran net covering the cathode from below. When the normal processing was continued without performing the silver recovery treatment, the adhesion of the silver-containing scale was observed on the processing container, particularly on the drain plate, particularly on the small holes.

[0053]

[Table 2] Sample No. B ′: Sample No. Nos. 11 to 16 cannot detect the presence of Cl in the noise. Sample No. B '
Found that the surface of polyethylene terephthalate was dissolved.

From the results shown in Table 2, the concentration of caustic soda was reduced to 0.2 to 3% by mass as compared with the conventional method.
It has been found that if the treatment is carried out at a temperature higher than 100 ° C., particularly 105 ° C. or higher, polyvinylidene chloride and the upper layer material on the polyethylene terephthalate substrate can be removed in a relatively short time.

(Example-12) A used X-ray photographic film using polyethylene terephthalate plastic as a base material was cut into chips corresponding to 0.5 to 1.5 cm square according to Example-11. Example-
11 sample no. According to No. 11, each processing was performed to obtain a processed chip (sample No. 17) and a regenerated film. The amount of foreign matter in the regenerated film was slightly lower than that of the standard film, and the quality was reusable. Further, the following recovery treatment was performed to obtain a processed chip and a regenerated film. As a first caustic treatment, a 0.7% by mass aqueous solution of caustic soda was used and treated at 90 ° C. for 10 minutes, followed by drainage. As a second caustic treatment, a 1% by mass aqueous solution of caustic soda was used at 110 ° C. Treated for 25 minutes. A water-washing process was performed for 6 minutes, and after a draining process, a drying process was performed. 18 and a regenerated film were obtained. Reusable quality. Processing sample No. 17, No. In both cases, flip the water on the chip surface. Further, as a result of analyzing the table by ESCA, the amount of the different organic substances was less than that of the practical standard film.

Example 13 A used cinema film manufactured by Fuji Photo Film Co., Ltd. using polyethylene terephthalate as a base material was equivalent to 0.5 to 1.5 cm square according to Example-11. Cut into chips. In the sample No. of Example-12. No. 18 for each processed chip sample No. 19 was obtained. The amount of foreign matter in the regenerated film was similar to that of the standard film, and the quality was sufficiently reusable. A developed cinema film made of polyethylene naphthalate as a base material and made in the same manner as the above-mentioned film using polyethylene terephthalate was treated in the same manner. 20
Got. Chip sample No. 20 repels water on its surface and does not infiltrate. As a result of surface analysis by ESCA,
The abundance of foreign organics was less than that of the standard film. As with the standard film, a sufficiently reusable quality could be obtained.

(Example-14) Fuji Photo Film Co., Ltd. using polyethylene terephthalate as a substrate
The used color print film was cut into chips. In the sample No. of Example-11. 13 was performed, and the processed chip sample no. 21 was obtained. The amount of foreign matter in the regenerated film was also equal to that of the standard film, and the quality was reusable.

Example 15 A pressure-sensitive photosensitive material manufactured by Fuji Photo Film Co., Ltd. using polyethylene terephthalate as a substrate was cut into chips. (Caustic Alkali Treatment) According to Example 11, a 1% by weight caustic soda was treated with a 110 ° C. hot aqueous solution for 40 minutes.
The treatment liquid was discharged, and the liquid was sufficiently drained. (Washing treatment) The chips were stirred while pouring water, and washed with water for 10 minutes. Drained. (Drying treatment) According to Example 11, drying was performed at 110 ° C for 40 minutes. 22 was obtained. Example-1
Create a reproduction film according to 1. Reusable quality was obtained. Similarly, a used heat-sensitive film using polyethylene terephthalate as a substrate was cut into chips. The processing chip sample No. 22 according to the processing chip sample No. 23 was obtained. Processing chip sample No. 22, 23
Both, flipped the water on the surface. Got reusable quality.

[0059]

According to the method for recovering a synthetic resin base material of the present invention, the amount of caustic alkali used can be reduced, the processing time can be further reduced, and foreign substances on the base material can be removed at a lower processing cost. . In addition, good-quality polycarbonate substrates and photographic polyester that can suppress the depolymerization of the substrate and can be reused
Films and the like can be collected relatively inexpensively and easily. Further, according to the method of the present invention, for a cellulose triacetate substrate or a polyester substrate coated with silver or a silver halide salt, a negative electrode is provided in a processing solution using an alkaline aqueous solution to reduce silver sufficiently. By simply applying a voltage (10 volts or less), silver can be recovered without adding a conventionally known different compound, and the generation of silver-containing scale adhering in the processing tank can be suppressed.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Keisuke Shiba 392 Hiromachi, Minamiashigara-shi, Kanagawa Prefecture Inside of PANAK KOGYO CO., LTD. (JP, A) JP-A-9-141657 (JP, A) JP-A-8-164524 (JP, A) JP-A-7-205154 (JP, A) (58) Fields investigated (Int. Cl. ⁷⁾ , DB name) C08J 11/06 B29B 17/02 G11B 7/26

Claims (8)

(57) [Claims] 1. After removing an extraneous layer provided on a substrate made of a synthetic resin in an alkaline aqueous solution at 105 ° C. or higher, 0.1 to 10% by mass of a peroxide
A method for removing a foreign layer, comprising treating with an aqueous solution containing : 2. A layer which is different in an alkaline aqueous solution having a pH of 10 to 14 and a temperature of 105 ° C. to 150 ° C.
After removal of
The removal method according to claim 1, wherein the removal method is further performed. 3. After removing the extraneous layer from a polycarbonate substrate provided with the extraneous layer in an aqueous alkali solution at 105 ° C. or higher , 0.1 to 10% by mass of a peroxide is used.
A method for recovering a polycarbonate substrate, comprising a step of treating with an aqueous solution containing 4. A dye-containing layer, a metal reflective layer, a photosensitive layer, a protective layer, subbing layer, and a polycarbonate substrate a functional layer selected from the group consisting of adhesive layer provided at least one layer,
The functional layer is substantially removed in an aqueous alkaline solution having a pH of 10 to 14 and a temperature of 105 to 130 ° C.
The method for recovering a polycarbonate substrate according to claim 3, comprising a step of removing . 5. The claims carried out by fresh alkaline aqueous solution of at least two steps removing step with an aqueous alkali solution
Item 5. The method for recovering a polycarbonate substrate according to item 3 or 4 . 6. A film having a thickness of 10 μm to 2 provided with a foreign layer.
No polyester film for photographic use of 00μm at 105 ° C
And a step of treating in a 150 ° C. alkaline aqueous solution.
How to collect polyester film for photography
Law. 7. A photographic polyester film having an undercoat layer.
Treated in an alkaline aqueous solution at 105 to 150 ° C.
7. The photographic polyester film according to claim 6, further comprising a step of
How to recover the film . 8. The method of claim 1 , further comprising at least one parent layer on the undercoat layer.
A polyester film for photography with an aqueous layer
The photographic polish according to claim 6 or 7, wherein the photographic polish is processed in an aqueous potassium solution.
Method for collecting ester film.