JPH10235320A - Reuse of treatment solution used in coating film peeling treatment by immersion and stirring of coating film waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To repeatedly reuse an alkali aq. soln. used in coating film peeling treatment due to the immersion and stirring of waste of a coating film such as a magnetic film or a photosensitive film. SOLUTION: An aftertreatment soln. left after the coating film peeling treatment by an alkali aq. soln. being an initial treatment soln. is brought into contact with a corresponding amt. of active carbon to adsorb the solute such as the binder or gelatin dissolved in the aftertreatment soln. by active carbon to remove the same, and the filtrate restored in the effect of a chemical agent is used as the treatment soln. of the next peeling operation. In the same way, the treatment soln. for peeling treatment is repeated reused by the contact operation with active carbon.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of immersing and agitating a coating film from the waste of a coating film obtained by applying a coating film to a base film made of a resin such as polyethylene terephthalate such as a magnetic film or a photosensitive film. More particularly, the present invention relates to a method for performing a stripping treatment, and more particularly, to a reuse of a treatment liquid used for the stripping treatment.

[0002]

2. Description of the Related Art Magnetic film waste (used magnetic cards and punching and cutting wastes (hereinafter referred to as magnetic cards) of the card films generated during the manufacturing process thereof), used magnetic films of floppy disks and manufacturing processes thereof. In the following, there will be simply generated cutting waste and cutting waste of the film (hereinafter referred to as FD magnetic film), and waste video tape and recording tape and the cutting waste of the film generated during the manufacturing process (hereinafter referred to as magnetic tape). A magnetic film formed of a magnetic iron powder and a binder as an adhesive is peeled off from a magnetic film, and a base film made of a resin such as polyethylene terephthalate (hereinafter, referred to as a magnetic film).
The method of collecting the base film) is a method in which a magnetic film and an appropriate processing solution are put in an appropriate container and are appropriately stirred at an appropriate temperature (hereinafter, a magnetic film and an after-mentioned method). A film in which a coating is applied to a base film such as a photosensitive film is referred to as a coating film, and a process of removing the coating by stirring while dipping the coating film in a processing solution is performed by dipping and stirring. (Coating film peeling treatment, immersion / stirring peeling treatment, coating film peeling treatment, peeling treatment or simply treatment), but a basic aqueous solution, particularly an alkaline aqueous solution containing caustic soda, is effective as the treatment liquid used here.

According to the technique of the present inventor, a magnetic film is immersed in an aqueous solution containing 1.5% by weight of sodium hydroxide and 0.2% by weight of sodium carbonate in an appropriate container, and these are appropriately immersed. When heated and stirred appropriately, the magnetic coating on the surface of the magnetic film peels off from the base film as thin film or powdery pieces (hereinafter referred to as thin magnetic film powder or floating precipitate). Floating or settling occurs in the processing solution. The base film can be reused as a resin if washed after being recovered from the processing solution.

However, there is still a problem in the practical use of the above-described magnetic film reproduction processing technology, and one of the problems is that a processing solution after peeling (hereinafter referred to as a post-processing solution) cannot be reused. It was a problem. That is, in the coating film peeling treatment by immersion and stirring, the binder of the magnetic coating film is initially dissolved to a considerable extent in an alkaline aqueous solution used as a treatment liquid (hereinafter, the alkaline aqueous solution before being used for the peeling treatment is referred to as a virgin liquid). However, if the liquid after treatment containing this binder is used for the next magnetic film peeling treatment even if the thin magnetic film powder that floats or precipitates in the liquid is filtered, the first virgin liquid will be used. The peeling efficiency was remarkably reduced as compared with the conventional treatment, and it was practically difficult to use the post-treatment liquid for the next treatment. For this reason, the post-treatment liquid is actually a waste liquid every time the treatment is performed.

[0005] For example, when an appropriate experimental container according to the technique of the present inventor is used, when the object to be peeled is 666 g of a cut piece of a magnetic card (hereinafter, a coated film to be peeled is referred to as a processed material. Is a condition in which the magnetic coating film and the printing ink layer are completely peeled off from the base film of the processed material under the conditions of appropriate heating and appropriate stirring (hereinafter, this is referred to as proper peeling or proper processing). In
4 liters of the virgin solution depending on the chemical composition and concentration is required, and the time required for proper treatment under the above conditions is 45 minutes (hereinafter, the time required for proper peeling under the proper and appropriate conditions using the virgin solution) Is referred to as a standard treatment time). When 616 g of the same treated material is treated again under the same conditions as in the first treatment by using 3.7 l of the liquid after the treatment in the first treatment, the proper peeling in the second treatment is required. Two hours and fifteen minutes were required. Next, an attempt was made to use the liquid after the second processing again (using the virgin liquid three times). However, most of the processed materials did not undergo peeling even after 3 hours, and in practice, it was difficult to properly peel off. Met.

Since the post-treatment liquid is reduced in the process of removing the thin magnetic film powder with a filter, it is practical to add a virgin solution to the treatment liquid to prepare the next treatment liquid. It cannot be denied that the peeling efficiency is greatly reduced as compared with the treatment using a liquid. For example, in an experiment in which the first processing was the same as the above, the second processing (processing object was 666)
In g), it was examined how much virgin liquid needs to be added to the liquid after the initial processing in order to obtain a proper peeling state in the standard processing time of 45 minutes.
0% addition (1.6 liters of virgin solution to 1.6 liters of solution after treatment)
1 addition) was required. After the processing of the second peeling treatment, the liquid was added by 80% (3.2 l added to the same 0.8 l) and the third peeling treatment was performed, but the unpeeled film still remains in the standard processing time. In the end, it was determined that it would be more practical to replace all of the treatment liquid.

The fact that the processing solution cannot be reused, that is, the use of a virgin solution for each process, means that the chemical cost increases each time the process is performed, and in practice, the post-process solution is neutralized each time. It is necessary to remove the dissolved binder with a coagulant or perform a process of activated sludge treatment, and the cost of equipment and chemicals required for these processes increases, which is considered to be a major obstacle to full-scale practical use. Had been.

[0008] Photosensitive film waste (waste X-ray film, photographic film, photographic / projection film, photographic paper, and cutting waste generated during the production process, etc.
In the immersion / stirring treatment for recovering the silver powder and the base film from the photosensitive film (hereinafter simply referred to as a photosensitive film), almost the same problems as those of the magnetic film described above remain. In other words, the photosensitive film is a base film coated with gelatin mixed with silver bromide (silver bromide is changed to blackened silver after development and fixing). An undercoat layer made of a resin different from that of the base film is provided between the layers. When the photosensitive film is subjected to coating film peeling treatment, if the container to be used is appropriate only for collecting the silver powder, if the container to be used is appropriate, the objective can be achieved simply by immersing the photosensitive film in warm water and stirring appropriately. In order to separate and collect an appropriate base film together with silver by peeling off the coating layer, treatment with a basic aqueous solution, particularly an alkaline aqueous solution containing caustic soda, is effective as in the case of the above-mentioned magnetic film.

For example, when an appropriate container for experiment according to the technique of the present inventor is used, the used X-ray film 6 which has been cut is used.
When peeling off the coating film including the undercoat layer from 66 g,
If 4 l of an aqueous solution containing 0.5% by weight of sodium hydroxide is used as a treatment liquid and the mixture is appropriately stirred while being appropriately heated, a properly peeled base film can be obtained in a standard treatment time of 20 minutes.

After processing, the blackened silver in the solution precipitates and can be easily recovered. The resin of the undercoat layer also separates and precipitates as a thin film piece, and thus can be removed by filtration with a filter cloth or the like (hereinafter, the peeled silver powder and the undercoat layer resin are also referred to as silver powder or floating precipitates).
However, even if the contaminants are collected and removed in this way, the post-treatment liquid containing the remaining dissolved gelatin cannot be actually used because the peeling efficiency is greatly reduced in the next treatment. In fact, the liquid had to be a virgin liquid. That is, even in the treatment of photosensitive film waste, the cost of chemicals increases, though not as much as that of magnetic film waste, and after a large amount of treated liquid is neutralized and activated sludge treatment is performed. Costly treatment of draining was needed.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-mentioned problems of magnetic film waste treatment and photosensitive film waste treatment. Alkaline aqueous solution used as a treatment solution for immersion and stirring peeling of coated films including films and photosensitive films. In the process of peeling, binder dissolves in magnetic films and gelatin dissolves in photosensitive films. After the treatment of the same aqueous solution, the liquid is not used as waste liquid.
It is an object of the present invention to provide a method for allowing the treatment liquid to be used as a treatment liquid for the next stripping treatment and for repeatedly reusing the original treatment liquid in the same manner.

[0012]

Means for Solving the Problems To achieve the above object, the method of the present invention is used as a treatment liquid in immersion and agitation peeling of coating film waste including a magnetic film and a photosensitive film. After the stripping treatment with the aqueous alkali solution, the remaining solution after the treatment is brought into contact with a considerable amount of activated carbon to adsorb the binder or gelatin (hereinafter also referred to as a solute) dissolved in the solution after the treatment to the activated carbon. By removing the liquid from the liquid and restoring the efficacy of the drug in the liquid, the liquid can be used for the next stripping treatment, and thereafter, the original processing liquid is repeatedly reused by the same method. Things.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The inventor has found through trial and error that a liquid after processing a magnetic film or a photosensitive film, which has been a waste liquid, has been reproduced and reused by a contact operation with activated carbon. In the first place, in the case of paint film waste, most of the technical information that is important for waste recycling treatment, such as the thickness of the paint film, the composition of the paint film material, the mixing ratio with magnetic iron powder and silver powder, and the method of coating. It is not disclosed, and therefore, it is unknown from the concentration of the solute in the aqueous alkali solution, and it is difficult to measure the solute concentration itself before and after activated carbon adsorption. Experiments needed to be stacked.

According to the results of these experiments, activated carbon (including plant-based activated carbon, coal-based activated carbon, petroleum-based activated carbon, bone charcoal, or those obtained by molding them) produced as a filter material / adsorbent, Activated carbon, including those obtained by mixing the above, is very useful for regenerating the liquid after treatment.
That is, a coating film obtained by coating a coating film on a base film made of a resin such as polyethylene terephthalate, such as a magnetic film or a photosensitive film, is agitated while being immersed in a processing solution in a container, thereby forming a base. In the coating film peeling treatment to peel the coating film from the film, initially, after collecting the base film after finishing the coating film peeling treatment using an aqueous alkali solution, the post-treatment liquid remaining as a used liquid,
Alternatively, the liquid after removing suspended precipitates from the liquid after the treatment is
If a considerable amount of activated carbon is contacted with a filter passing method or a mixed solid-liquid separation method described below, and the resulting filtrate is used for the coating film peeling treatment, the standard treatment time with the initial virgin solution is used. It is possible to obtain a state of proper peeling of the processed material (hereinafter, when performing a peeling process using a filtrate by an operation of contacting with activated carbon, when a proper process can be obtained in a standard processing time with an initial virgin solution) The filtrate is said to be "sufficiently usable", and the activated carbon used at this time and its amount are said to be "effective."
The effective g weight of activated carbon is referred to as a considerable amount, and if the amount is further reduced under the saturated adsorption state of activated carbon, the filtrate cannot be sufficiently used.

The considerable amount of activated carbon necessary for reusing the post-treatment liquid is as follows: (a) the type of the treated product, especially the thickness of the coating film;
(B) concentration of sodium hydroxide in the virgin solution, (c)
It depends on the time of the peeling treatment, (d) the type of activated carbon used, and (e) the method of contacting with activated carbon. However, among these (b) and (c), in the technique of the present inventor, appropriate values are generally determined as appropriate densities and standard processing times. The amount of activated carbon required to regenerate the liquid is
It is determined depending on the type of the treated material, the type of the activated carbon and the contact method.

Among the magnetic films, the one having a thin coating film and a small amount of a dissolved binder is a solution after processing a magnetic tape for audio. Conversely, the most difficult to reproduce and use is because the amount of binder is large and the printing ink is also dissolved in the processing liquid, and the most difficult to use is the post-magnetic-card processing liquid. The photosensitive film also has a considerably high solute concentration because the gelatin coating is completely dissolved in the liquid after the treatment by heating in the peeling treatment, and the equivalent amount of activated carbon is about twice that of the magnetic tape. The most effective activated carbon in the regeneration of the liquid after the magnetic tape treatment for audio, which requires a small amount of activated carbon, is granulated activated carbon for liquid phase purification based on coconut shell charcoal. When the saturated adsorption was carried out for 1 hour by the separation method, it was effective up to 1 g of the same activated carbon per liter of the liquid after the treatment.

In the same manner, the most commonly used granular coconut shell activated carbon for water purification was examined for its lower limit in its saturated adsorption state, and found to be about 3.4 g per liter of the liquid after magnetic card treatment. , About 1.4 g for FD magnetic films, and about 2.2 g for X-ray films. However, this lower limit is a limit for the contact time with activated carbon of one hour, and in view of the time efficiency of the filtration treatment, a value larger than this actually has to be considerable. In particular, if the contact method is constant-pressure water flow to the activated carbon layer, the equivalent amount of activated carbon needs to be about 1.5 to 2 times the lower limit. In the case of a filter using granular coconut shell activated carbon, the amount to be filled is 4.5 to 6.5 g per liter of the liquid after magnetic card treatment, and the same for FD magnetic film and magnetic tape. It is preferable that the weight is 2.5 to 3.5 g and that of an X-ray film is 3 to 5 g (hereinafter, these are referred to as filtration standard values of granular charcoal). The difference of the preferable equivalent amount depending on the type of the activated carbon is not so large in the activated carbon manufactured as the filtering material and the adsorbing material, and is at most 1% after treatment.
It is in the range of 1 g per liter. However, the required amount of the coconut shell activated carbon and the charcoal for fuel has a difference of about twice.

The amount of activated carbon can be kept low by using a filter medium other than activated carbon such as porous fiber or a filter supplement such as diatomaceous earth or perlite in combination with activated carbon in the contacting operation. Activated carbon alone is sufficient, and considering the post-treatment and cost of the filter media or filter supplement, the use of activated carbon alone seems to be more efficient.

As a method for contacting with activated carbon, a vessel filled with activated carbon is provided in a container and a filtered liquid is passed through the layer after the treatment, or the treated liquid is introduced into a tank or pond (pool). Activated carbon is poured into the stored liquid, mixed by stirring, etc., and then the liquid is filtered with a filter.As a result, there is a mixed solid-liquid separation method in which a filtered liquid with activated carbon is obtained. You may. Further, these two methods may be used in combination.

[0020] The filter, as used in the experiments described below,
A wide-diameter stainless steel pipe is attached with a filter of a mesh that does not allow activated carbon particles to pass through with one port facing down, and the pipe on the filter is filled with activated carbon.
An extremely simple one in which the solution after treatment is poured from the upper port is sufficient. Needless to say, it is desirable to use an industrial filter that can attach and detach a cartridge filled with activated carbon and that can easily adjust the amount of flowing water and the pressure thereof. Further, a filter in which the activated carbon layer is not a fixed bed but a moving bed or a fluidized bed may be used.

It is preferable that a considerable amount of the activated carbon to be filled in the filter is prepared in consideration of the above-mentioned filtration standard value of the granular coal and the adsorption characteristics of the activated carbon to be used. In the activated carbon filter prepared in this way, the post-treatment liquid remaining after performing the stripping treatment with the virgin liquid is initially taken into account the adsorption speed that differs depending on the type, particle size, particle size uniformity, packing density, and pore distribution of activated carbon. Then, the liquid is passed in a state where the passage speed of the activated carbon layer does not exceed the adsorption speed of the activated carbon layer. In this case, the filtrate coming out of the filter can be sufficiently used as a treatment liquid for the next stripping treatment.

In the immersion / stirring stripping process, usually, after the stripping process is completed, first, the base film is recovered from the processing solution, and the suspended precipitate in the solution is removed with a filter having an appropriate mesh. Although treatment is performed, it is appropriate that filtration of the liquid after treatment with activated carbon is also performed on the liquid after these treatments. If the floating precipitates are not removed, they cause clogging of the activated carbon layer.

Also, due to the above treatments and the like, the treated liquid is reduced by about 7 to 12% as compared with the original treated liquid, and there is a slight loss in the passage through the activated carbon filter. In this case, it is practical to add a virgin solution to the same solution in an amount of about 12 to 20% to obtain a processing solution for the next stripping process. However, it is considered that this method will be used in practical use.

If a sufficient amount of the activated carbon to be filled in the filter is set to be sufficiently large from the beginning, the shortage of the filtrate as the next treatment liquid is supplemented with a virgin liquid so that the next stripping treatment of the same treated material can be properly performed. After the treatment, the liquid after the treatment of removing suspended precipitates was passed through the activated carbon filter used once again to obtain a second filtrate, which was sufficiently used for the next stripping treatment. Can be used. Similarly, if a sufficient amount of activated carbon in the filter is reserved,
Alternatively, if this is renewed, it is possible to filter the solution after treatment using the same activated carbon, and repeat the appropriate peeling treatment many times while supplementing the deficiency of the filtrate with the virgin solution. it can. In this way, by repeatedly using the treatment liquid, there is no need to substantially treat the treated liquid as a waste liquid.

When the liquid after the treatment is regenerated with a filter, the activated carbon used is preferably one that can also regenerate the activated carbon itself. That is, activated carbon fired at a high temperature of 750 to 950 ° C. can recover (regenerate) the adsorptive power by the cultivation reactivation method even if the solute adsorptive power is lost by use, and the treated liquid is This is because, together with the recycling and use, the filter medium for that can be recycled and used, and one closed system can be constructed in the waste treatment.

In the method based on the mixed solid-liquid separation method, for example, in an experiment to be described later, a stainless steel can is used as a mixing tank, and the liquid after removing suspended precipitates from the treated liquid is poured into this can. At the same time, activated carbon is put into a can and stirred and mixed with a stirring rod, and the liquid is filtered with a filter cloth, and the filtrate is used for the next peeling treatment. Needless to say, it is desirable that the mixing tank is one in which the injection of the post-treatment liquid, the charging of the activated carbon, the stirring, and the solid-liquid separation can be performed automatically. In addition, in the mixing tank, the effect may be enhanced by mixing a solute adsorbent other than activated carbon and / or a coagulant or both together with activated carbon.

When the activated carbon is mixed with the treatment liquid in the mixing tank, the required substantial amount depends on the type of the treated material, the type of the activated carbon to be used, and the mixing time. Should be considered as a reference. This is because it is determined that the lower limit of the amount of powdered activated carbon useful in the mixed solid-liquid separation method in saturated adsorption is not less than 0.5 g per liter of the liquid after treatment from the lower limit of the granular carbon. If the mixing time is properly set and the solid-liquid separation is properly performed, the filtrate obtained as described above can be sufficiently used for the next stripping treatment of the same processed material. When the activated carbon filtrate obtained by solid-liquid separation and recovery from the mixing tank is used as a treatment liquid for the next stripping treatment, a virgin solution may be added in the same manner as in the case of using the filter. .

In the magnetic film treatment, after the base film is recovered from the liquid after the treatment, the thin magnetic film powder is not removed and the mixture is directly guided to a mixing tank, the binder is adsorbed by activated carbon, and the liquid is filtered and then separated. On the other hand, it is efficient that the remaining thin magnetic film powder and activated carbon are incinerated after being naturally dried, and the residual ash is washed with water or the like to collect the magnetic iron powder with a magnet. In this case, it is presumed that the cost-effectiveness is improved because cheap powdered activated carbon, which is not suitable for regeneration, can be used.

The same applies to the photosensitive film. The liquid after treatment after collecting the base film is led to a mixing tank containing silver powder and the like, mixed with activated carbon, and filtered with a suitable filter. It is efficient that the solid content containing activated carbon remaining in the filter is dried and incinerated to collect silver powder while being used for the treatment.

It is desirable that the concentration of sodium hydroxide in the virgin solution is low. The higher the concentration of sodium hydroxide, especially in the case of magnetic film processing, the higher the concentration of the dissolved binder, the faster the activated carbon loses its adsorptive power. However, when the concentration of sodium hydroxide is 2
% By weight or less, and if the liquid after the treatment is at the standard treatment time, the liquid can be regenerated with an appropriate amount of activated carbon based on the filtration standard value of the granular carbon, and the filtrate is subjected to the next peeling. Can be used sufficiently for processing. In addition, even if the liquid after treatment is filtered with activated carbon, the pH value of the filtrate is almost the same as the liquid after treatment before filtration in comparison at the same liquid temperature.
Even in the case of an aqueous solution having a low sodium hydroxide concentration, the filtrate is not unusable because it is filtered with activated carbon. For all concentrations in the concentration range of 0.2 to 2% by weight of sodium hydroxide required for the immersion and agitation peeling treatment of the magnetic film and the photosensitive film, the solution after the treatment can be sufficiently used by filtration with activated carbon.

As a treatment solution for the magnetic film, an aqueous solution obtained by adding a little sodium carbonate to sodium hydroxide is useful. However, even if an activated carbon filtrate as a solution after the treatment is used, the stripping effect is hardly changed. That is, activated carbon is considered to be neutral with respect to this sodium carbonate. For all combinations of the concentration range of 0.05 to 0.5% by weight of the same chemical used and the concentration range of 0.2 to 2% by weight of the above sodium hydroxide, the treated liquid was brought into contact with activated carbon in an appropriate considerable amount. If operated, the filtrate is fully usable.

According to the present invention, when the alkali aqueous solution used for the coating film peeling treatment by dipping and stirring is brought into contact with activated carbon in an appropriate amount and the filtrate is used for the next peeling treatment, the initial virgin liquid Although it is a very simple thing that the proper treatment of peeling can be performed almost as it is, it is extremely effective, and the efficiency of the recycling and recovery processing of the waste coating film including the recovery of silver or magnetic iron powder is improved. . However, there are many unclear points, especially if it is clear that the binder or gelatin in which the activated carbon is dissolved is adsorbed, but the liquid after adsorption and removal of these is why the liquid is used initially. The reason that the virgin liquid can be used for the peeling treatment with almost the same effect as the virgin liquid-which is related to the mechanism of peeling off the coating film of the alkaline aqueous solution-is not clear even to the inventor. Hereinafter, various experiments on which the present invention is based will be described as examples.

[0033]

Embodiment 1 Punching frame for magnetic film (FD punching frame) generated in the process of manufacturing a floppy disk
The virgin solution is an aqueous solution containing 1.5% by weight of sodium hydroxide and 0.2% by weight of sodium carbonate, and in the stripping treatment for a standard treatment time of 40 minutes, the liquid after the first treatment is used. An experiment was performed in which the activated carbon was brought into contact with a filter by a filter passing method, and the filtrate was used for the next stripping treatment. Here, as the activated carbon filter, a stainless steel funnel having an upper diameter of 120% was prepared, a filter cloth was laid inside the funnel, and 30 g of granular coconut shell activated carbon was put therein (see Table 1 for the activated carbon used). The table lists the specifications of the activated carbon used in the following experiments.)

[0034]

[Table 1]

The experiment will be described.
g was placed in an appropriate container for experiments, immersed in 4 l of virgin solution, heated appropriately, and stirred appropriately to perform the first peeling treatment of the magnetic coating film. Under these conditions, the processed product is normally properly peeled with a standard processing time of 40 minutes.
In this initial processing, the result of the appropriate processing was obtained.

After recovering the base film from the liquid after the first peeling treatment, the liquid was filtered with a filter cloth to remove floating or precipitated thin magnetic film powder. In the process so far, the liquid has been reduced to 3.62 liters due to adhesion to the container and the filter cloth and adsorption of the removed matter. The liquid after this treatment was gently poured into the activated carbon filter, and the filtrate flowing out was collected.
In addition, the temperature of the solution after the treatment injected into the filter was 45 ° C. Then, 3.60 l of the collected filtrate is used as it is as a treatment liquid for the next stripping treatment, and the treatment liquid is smaller than the first treatment liquid.
The next stripping process was performed with the processed material reduced by the same ratio. This next processing was also completed in 40 minutes, which is the same as the standard processing time with the first virgin liquid, and the peeling state of the base film was inspected. That is, 10% by weight of the test sample was extracted from the treated base film, and each of these sample pieces was checked for any unremoved coating film or whether there was any color spot due to unremoved binder and printing ink. Inspection was made visually. As a result, the treatment using the filtrate obtained by passing through the activated carbon filter as the treatment liquid was in a proper peeling state without any problem.

[0037]

EXAMPLE 2 AND COMPARATIVE EXAMPLE Next, the used magnetic card was cut into half, and the processed material was cut into 666 g. The chemical composition and concentration of the virgin liquid and the initial amount of the liquid were the same as in Example 1. However, following the stripping treatment in which the standard treatment time was 45 minutes, the following two experiments were performed to confirm the difference between the stripping treatments of the activated carbon filtrate and the non-filtrate. That is, one does not filter the solution after the treatment with activated carbon, and removes the thin magnetic film powder from the solution after the treatment by 10%.
3.2 l of the liquid removed by the 0 mesh filter
, 0.8 l of virgin solution was added to make the next processing solution,
In the experiment (comparative example) in which the peeling treatment is performed, the treated liquid is passed through the same funnel-type activated carbon filter as in Example 1, and 0.2 l of virgin liquid is added to 3.2 l of the filtrate. This is an experiment (Example 2) in which the next peeling process is performed. In addition, the activated carbon put into the funnel-type filter in Example 2 was a raw coconut shell activated carbon 3 ground to 3 to 15 mesh.
0 g was used.

The results of Comparative Example and Example 2 are as shown in Table 2.
In Example 2 using the activated carbon filtrate, the standard treatment time was 4 hours.
Although the result of proper peeling without any problem was obtained in 5 minutes, in the case of using the post-treatment liquid without the activated carbon filtration of the comparative example, 6% of the processed material was obtained in 45 minutes despite the addition of 20% virgin solution.
6% was in an improper peeling state in which the magnetic coating film had not yet peeled off, or the binder and the printing ink had still remained thinly. By the way, the film sample of the inspection was returned to the container of the peeling process, and the peeling process was continued while repeating the inspection until the proper peeling state was reached. It took just 2 hours to reach the proper peeling state with this processing solution. there were.

[0039]

Example 3 An experiment on a liquid after treatment of a photosensitive film waste was carried out in substantially the same manner as in Example 1. First, the processed material is 666 g of used X-ray film (X-ray FLM) cut into a rectangle of about 20 m / m × 30 m / m, and the virgin liquid as the first processing liquid contains 0.5% by weight of sodium hydroxide. 4.0 liters of aqueous solution, the standard processing time of which is 2
Inspection of the peeling state for 0 minute is performed by extracting 5% by weight of the washed base film after the treatment, and inspecting the non-transparency of the base film by the unstripped silver-containing gelatin coating film or the undercoat layer using a loupe. is there.

The filter was the same as in Examples 1 and 2, and the activated carbon used was 30 g of coal-based granular activated carbon. After treatment,
A solution obtained by filtering the exfoliated silver powder and thin film pieces of the undercoat layer resin with a filter cloth and gently pouring the solution into a funnel-type filter to obtain a filtrate as it is as the next treatment solution (virgin solution) Is the same as in Example 1 in that the number of processing objects is reduced instead of not adding). In the next treatment use of the filtrate, the result of proper peeling without any problem was obtained in the standard treatment time with the first virgin solution.

[0041]

[Table 2]

[0042]

Examples 4 to 7 In various coating film waste treatments, various experiments were conducted to determine the lower limit of the amount of activated carbon in the liquid after the treatment, and important results were extracted from these experiments. This will be described below.

In the experiment, a magnetic card (specifications were the same as in Example 2), a magnetic film for FD (same as in Example 1), a magnetic tape (used audio tape of 50 m) were used.
/ M) and an X-ray film (the specifications are the same as in Example 3). Concentration (in the range of 0.2 to 2.0% by weight of sodium hydroxide and 0.05 to 0.5% by weight of sodium carbonate for both the magnetic film and the photosensitive film).
The standard processing time is 45 minutes for magnetic card, 40 minutes for FD magnetic film, 35 minutes for magnetic tape, and 2 minutes for X-ray film.
0 minutes.

The activated carbon used is of two types, granular coconut shell activated carbon and wood-based powdered activated carbon (hereinafter abbreviated as granular charcoal and powdered charcoal). Was added and mixed, and then the mixed liquid was subjected to solid-liquid separation. This is because, in this experiment, it is necessary to see the lower limit of the amount of activated carbon in the saturated adsorption state, and it is necessary to make the activated carbon come into contact with the liquid after treatment for a relatively long time of about 1 hour to reach the state of adsorption equilibrium. is there.
A 12-liter stainless steel can was used as a mixing tank, and mixing and stirring with activated carbon was performed with a stirring rod. The activated carbon was charged, and the mixed solution after one hour had passed was filtered through a filter cloth to obtain a filtrate. For the next use of the filtrate, the virgin solution was not added for the purpose of checking the limit of its effectiveness.
5 l was used for the next processing. In addition,
The peeling treatment was performed by reducing the weight of the treated material.

The search experiment for the lower limit of the equivalent amount of activated carbon based on the above specifications is a simple one in which the first and next peeling treatments are repeated while reducing the amount of each activated carbon per 1 liter of the treated liquid. As for the granular charcoal of the liquid after the magnetic card treatment, when the amount was reduced by 1 g from 6 g per liter of the liquid, the processed material was improperly peeled by 5% at 3 g per liter of the liquid. However, at 3.5 g, proper peeling was obtained. That is, it is considered that the lower limit of the amount of the granular coal in the liquid after the magnetic card processing is slightly less than 3.5 g per liter of the liquid. Table 3 summarizes the results of a magnetic card as Example 4 (hereinafter, the weight of activated carbon per liter of the treated liquid is also expressed as g / l). It is appropriate to consider that both the granular coal and the powdered coal are about 3.4 g / l.

[0046]

[Table 3]

The results of the magnetic film for FD obtained by conducting the experiment in the same manner as the magnetic card are as shown in Example 5 of Table 4. The lower limit of the equivalent amount of the magnetic film for FD can be determined to be about 1.5 g / l for granular charcoal and to cut it slightly with powdered charcoal.

[0048]

[Table 4]

As shown in Example 6 in Table 5, the liquid after treatment of the magnetic tape has the lowest lower limit in the amount of the treated material. Powdered charcoal was 3% improper peeling at 1g / l,
Only a few improper release films were seen with the granular coal. The lower limit for both coals is from 1.2 g / l to 1.
It seems to be around 4 g / l. In addition, when granulated activated carbon for liquid phase purification based on coconut shell charcoal was saturated and adsorbed under the same conditions, the liquid after the magnetic tape treatment was effective up to 1 g / l.

[0050]

[Table 5]

The experimental results of the X-ray film are shown in Table 6 in Example 7.
From this result, it is determined that the lower limit of the amount of activated carbon in the liquid after the treatment of the X-ray film is about 2.2 g / l.

[0052]

[Table 6]

[0053]

Example 8 When a considerable amount of activated carbon was taken sufficiently,
The number of times the virgin solution used for the first time can be reused using the same activated carbon was tested in the magnetic card peeling treatment and the contact operation was conducted by a filter passing method. Table 7 shows the specifications of the experiment. That is, first, the inner diameter 57m /
A stainless steel filter of 30 mesh was attached to the bottom of a stainless steel pipe having a length of m, and an activated carbon filter was prepared in which 190 g of granular coconut shell activated carbon for water purification was filled in the pipe. The packing density of activated carbon in the filter is 0.44 g / cm.
It was ³ . The processed material was 1 / of the same magnetic card as in Example 2.
Two cut pieces, 666 g, the initial virgin solution was 4 l of an aqueous solution containing 1.5% by weight of sodium hydroxide and 0.2% by weight of sodium carbonate, and the standard processing time was 45 minutes. The liquid after the treatment was passed through the above-mentioned filter, and all the liquid after the treatment was poured into the upper portion of the pipe, and the liquid was allowed to pass naturally by the liquid pressure. The liquid was passed through the liquid after removing the thin magnetic film powder. Also,
The liquid temperature of the liquid after the treatment was 35 ° C., and the liquid was passed. Since it takes time to collect the whole amount of the filtrate, the filtrate to be used next time is 3.2.
1 and 0.8 l of virgin liquid was added each time the peeling treatment was performed.

[0054]

[Table 7]

Based on the above experimental specifications, only the first stripping treatment was performed with a virgin solution, and the subsequent treatment was performed with a treatment solution obtained by adding a 20% virgin solution to an 80% activated carbon filtrate, and 190 g of the same activated carbon was used. The stripping process and the inspection were repeated using the filter repeatedly. The results of this experiment are as shown in Example 8 of Table 8. In the re-use experiment of this treatment solution, it was possible to sufficiently use the filtrate which was passed 10 times with a filter filled with 190 g of granular coconut shell activated carbon (this was due to the cumulative amount of the injected liquid or the amount of the recovered liquid). The activated carbon is at a stage of 5.1 to 5.3 g / l). That is, 12
In the fourth stripping process (using the filtrate after 11 passages)
% Improper peeling appeared. When the experiment was further continued, the clogged state of the filter became remarkable when the filter was used 14 times (the time required for the filtration became extremely long). In the 16th filtration, the filter was used at the beginning of the filtration. The liquid was almost completely clogged, where the dripping state of the liquid continued for a long time. This granular activated carbon is considered to have reached a state close to almost saturated adsorption on the 16th passage, but the cumulative injection volume up to this point is about 56 l, and the activated carbon is 3.4 per 1 l of the same liquid.
g, about 52
1, 3.7 g.

In this experiment, the filtration was performed by natural hydraulic pressure, but the recovery time of the liquid from the 9th passage was rapidly increased. Actually, a constant-pressure flow is employed, so even if the ninth and tenth filtrates may not be sufficiently used under a constant pressure, they can be repeatedly used up to eight times. Can be determined.

[0057]

[Table 8]

[0058]

According to the present invention, since the method is as described above, the following effects can be obtained.

Conventionally, after the waste liquid is neutralized, the solute in the liquid is removed by administering a polymer coagulant or activated sludge treatment, and depending on the case, both treatments have to be taken. The post-treatment liquid of the alkaline aqueous solution used in the immersion and agitation peeling treatment of the coating film waste such as the magnetic film waste and the photosensitive film waste can be sufficiently used for the next peeling treatment. . In addition, this reused processing solution can be reused in the next stripping process.

If a sufficient amount of activated carbon, which is a decisive factor for regenerating the liquid after treatment, is sufficiently large, filtration of the liquid after treatment is carried out by the same operation as that of activated carbon, and the shortage of the filtrate as a treatment liquid is reduced. The original alkaline aqueous solution can be reused many times repeatedly while supplementing with virgin alkaline aqueous solution. In addition, when the activated carbon is in a state of saturated adsorption, if the activated carbon is renewed, the treated liquid is not substantially treated as a waste liquid.

As described above, since the activated carbon filtrate can be sufficiently used as the next processing liquid, the use of a virgin liquid every time of the stripping treatment becomes unnecessary, and the cost of the alkali chemicals required for the treatment of the coating film waste is reduced. It is greatly reduced.

Since the necessity of a neutralizing agent and a coagulant administration treatment and an activated sludge treatment of the post-treatment liquid, which had to be used as a waste liquid every time of the stripping treatment, is eliminated, the recovery of the base film by the coating film stripping and the magnetic iron The cost of collecting powder or silver powder is greatly reduced.

If the activated carbon that can be reactivated and regenerated is used, not only can the processing solution in the coating film peeling treatment be reused, but also the activated carbon that makes this possible, while compensating for the loss in regeneration, In the sense that it can be reused,
One closed system can be constructed in coating film waste treatment.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI C23F 1/46 B09B 5/00 ZABR

Claims (12)

[Claims] In a coating film peeling treatment for peeling a coating film from a base film by agitating while immersing a waste of the coating film in which a coating film is applied to a base film in a processing solution in a container, As a liquid, after the coating film peeling treatment is completed using an alkaline aqueous solution and the base film is recovered, the post-treatment liquid remaining as a used liquid is contacted with a considerable amount of activated carbon to obtain a filtrate obtained by the operation. A method for reusing a treatment liquid used in a coating film peeling treatment by immersing and stirring coating film waste, which is used as a treatment liquid for a coating film peeling treatment. 2. The coating film peeling treatment according to claim 1, wherein the coating film is one of a magnetic card, a magnetic film for a floppy disk, and a magnetic tape. To reuse the processing solution used in the process. 3. The coating film waste according to claim 1, wherein the coating film is one of an X-ray film, a photographic film, a photographing / projection film, and a photographic paper. A method of reusing the treatment liquid used in the coating film peeling treatment. 4. The coating film according to claim 1, wherein the aqueous alkali solution is an aqueous solution containing 0.2 to 2% by weight of sodium hydroxide and 0.05 to 0.5% by weight of sodium carbonate. A method of reusing a treatment liquid used in a coating film peeling treatment by immersing and stirring waste. 5. The coating film obtained by immersing and agitating a coating film waste according to claim 1, wherein the alkaline aqueous solution is an aqueous solution containing 0.2 to 2% by weight of sodium hydroxide. A method of reusing the processing solution used in the stripping process. 6. The contact operation with the activated carbon may be performed by using a filter filled with activated carbon or a filter filled with a filter material other than activated carbon and / or a filter supplement other than activated carbon. The method for reusing a treatment liquid used in a coating film peeling treatment by immersion and stirring of the coating film waste according to claim 1, wherein the liquid is passed. 7. The contact operation with the activated carbon may be performed by introducing the liquid into a tank mixed with the activated carbon or into a tank mixed with an adsorbent other than the activated carbon and / or a coagulant in addition to the activated carbon. The method for reusing a treatment liquid used in a coating film peeling treatment by immersion and stirring of a coating film waste according to claim 1, wherein after the mixing is performed, the solid and the liquid are separated with a suitable filter. . 8. The immersion of the coated film waste according to claim 1, wherein the operation of contacting the activated carbon is performed by using both the operations described in claim 6 and 7. A method of reusing a treatment liquid used in a coating film peeling treatment by stirring. 9. The activated carbon is any one of plant-based activated carbon including coconut shell charcoal, main fuel for fuel, coal-based activated carbon, petroleum-based activated carbon, bone charcoal, a molded product thereof, and a mixture thereof. Certain claims 1 and 2 or 3 and 4
Or a method of reusing a treatment liquid used in a coating film peeling treatment by immersion and agitation of the coating film waste described in 5 or 6 or 7 or 8. 10. The method according to claim 1, wherein the equivalent amount is 1 g or more of activated carbon per liter of the treated liquid. 1 or 2 or 3 or 4 or 5 and 6 or 7 or 8 or 9. A method of reusing a treatment liquid used in a coating film peeling treatment by dipping and stirring coating film waste. 11. The liquid after treatment is a liquid after removing suspended matters or precipitates such as thin magnetic film powder or silver powder peeled from a coating film, and the liquid after the treatment is two or three, and 4. A method for reusing a treatment liquid used in a coating film peeling treatment by immersion and agitation of a coating film waste described in 4 or 5, and 6 or 7 or 8, 9 and 10. 12. The treatment liquid used in the next and subsequent coating film peeling treatments is a filtrate or a liquid obtained by additionally mixing an alkaline aqueous solution with the filtrate. 5. A method for reusing a treatment liquid used in a coating film peeling treatment by immersion and agitation of coating film waste as described in 5, 6 or 7, or 8, 9 and 10, or 11.