JP2002265665A - Method for recovering mold release film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for recovering a mold release film, by which a mold release layer formed on the surface of the mold release film can readily be separated and removed to recover only a clean substrate film. SOLUTION: This method for recovering the mold release film is characterized by immersing a mold release film in which a mold release layer is formed on at least one side of a substrate through an easily dissolvable resin layer, after used, in a solvent capable of dissolving the easily dissolvable resin to dissolve the easily dissolvable resin in the solvent, whereby the mold release layer on the surface of the film is separated and removed to recover only the substrate film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recovering a release film used for various purposes, and more particularly, to a method for manufacturing electronic components such as ceramic capacitors, ceramic substrates, and dry film resists. Alternatively, the present invention relates to a method for collecting a release film used as an adhesive release paper such as a polarizing plate separator and a label release paper.

[0002]

2. Description of the Related Art Conventionally, a release film in which a release layer such as a curable silicone resin film is formed on a surface of a thermoplastic resin film such as a polyester film has been used for electronic devices such as ceramic capacitors, ceramic substrates, and dry film resists. It is used in large quantities as a film for component manufacturing processes or as an adhesive release paper such as a polarizing plate separator and a label release paper.

[0003] For example, with the recent widespread use of mobile communication devices and portable information terminal devices such as mobile phones and portable personal computers, the production of multilayer ceramic substrates and multilayer ceramic capacitors used in these electronic devices has been advanced. In the process, a large amount of a release film for producing a ceramic green sheet is consumed. This release film peels off the green sheet formed on the release film,
At present, after a ceramic laminate is produced by a multilayer lamination method, it is discarded together with the ceramic remaining on the release film.

[0004] On the other hand, in recent years, collection and recycling of PET bottles has become a major issue in the field of the release film as described above, as the collection and recycling of PET bottles is becoming popular from the viewpoint of protecting the earth resources and the global environment. However, when the release film in which the ceramic remains is recovered and used as it is, for example, when the release film after use is re-melted to form a film, the filtration process after melt extrusion is performed. There is a problem that the ceramic remaining in the above causes clogging of the filter, and as a result, normal film formation cannot be performed. Also, even if the remaining ceramic is forcibly removed by mechanical scraping or the like, the release layer such as a curable silicone resin film formed on the surface of the release film is mixed into the molten polymer. , Due to the decrease in polymer melt viscosity, decrease in mechanical properties and film formation stability, occurrence of surface coarse protrusions and coarse defects, coloring, it is difficult to suppress the smell during extrusion, etc.,
It could not be reproduced as a practical film.

In other words, in order to recover only the base film from the used release film, a release layer such as a curable silicone resin film formed on the surface of the release film is required.
It must be completely removed in some way. However, it is difficult to completely remove the release layer by any of the methods considered at present, and since a great deal of labor and cost cannot be avoided, it has not yet been put to practical use. It is a fact.

[0006]

SUMMARY OF THE INVENTION In view of the background of the prior art, an object of the present invention is to easily separate and remove a release layer formed on the surface of a release film and recover only a clean base film. It is intended to provide a method for collecting a release film capable of performing the above-mentioned process.

[0007]

The present invention employs the following means in order to solve the above-mentioned problems. That is, the method for collecting a release film of the present invention is a release film in which a release layer is formed on at least one surface of a base film via a readily soluble resin layer, and the release film after use. By immersing in a solvent in which the easily soluble resin can be dissolved and dissolving the easily soluble resin in the solvent, the release layer on the film surface is separated and removed, and only the base film is collected. It is assumed that.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention has been made to solve the above problem, that is, to easily separate and remove a release layer formed on a release film surface,
As a result of intensive studies on a method of collecting a release film that collects only a clean base film, a release film in which an easily soluble resin layer is interposed between the base film and the release layer is used, for example, in a ceramic green. After being used in a manufacturing process of a sheet or the like, the release film after use is immersed in a solvent in which the easily soluble resin can be dissolved to dissolve the easily soluble resin. It has been found that the mold layer can be easily separated and removed, and such a problem can be solved at once.

[0009] That is, the present invention is to immerse the used release film in water or other appropriate solvent to separate and remove the release layer on the surface of the release film, thereby removing only the clean base film. It has been successfully recovered.

As the base film in the release film of the present invention, polyester films, polyimide films, polypropylene films, polyamide films, polycarbonate films, polyacetate films, polyethylene films, polyphenylene sulfide films, cellophane and the like can be used. Among them, polyester film is preferable in terms of heat resistance and strength,
In particular, polyethylene terephthalate, which can be recovered and recycled,
A polyester film containing polyethylene naphthalate as a main component is preferably used.

[0011] The thickness of the substrate film in the present invention is not particularly limited.
~ 200 µm is preferably used.

The release film of the present invention has a readily soluble resin layer interposed between the base film and the release layer. The easily soluble resin is not particularly limited, but is preferably a water-soluble or water-dispersible resin in consideration of the load on the environment at the time of recovery. Among them, a resin composed of at least one of a water-soluble or water-dispersible polyester resin, polyester urethane resin, acrylic resin, ethylene ionomer resin, polyvinyl alcohol resin, and ethylene-vinyl alcohol resin is preferable.

The water-soluble resin according to the present invention has, for example, a polymer dictionary (Maruzen Co., Ltd.) No. 4 in its molecular structure.
Those containing a hydrophilic functional group described on page 88 and FIG. 2 are preferable, and among them, a hydroxyl group, an ether group, an amide group, a carboxyl group, a phosphate group, a sulfonic group, an amino group, an imino group and a carboxylate group are preferred. And more preferably those containing at least one selected from a hydroxyl group, a carboxyl group, a sulfonate group and a carboxylate group.

Specific water-soluble resins include potato starch, potato starch, tapioca starch, wheat starch, cornstarch, konjac, seaweed, agar, sodium alginate, troloioi, tragacanth gum, gum arabic, dextran, glue, gelatin, gelatin, Casein, collagen, viscose, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, carboxymethyl cellulose, soluble starch, carboxymethyl starch, dialdehyde starch, polyvinyl alcohol, sodium polyacrylate, polyethylene oxide, Polyacrylamide, polyacrylic acid,
A water-soluble resin such as poly N-vinyl pidridone is preferably used. These may be used alone,
Two or more kinds may be used in combination. Among them, polyvinyl alcohol and its copolymer are more preferably used in terms of strength, heat resistance, organic solvent resistance and the like. In particular,
"Poval" PVA-102, PVA- manufactured by Kuraray Co., Ltd.
103, PVA-105, PVA-110, PVA-1
17, PVA-117H, PVA-120, PVA-1
24, PVA-CSA, PVA-CST, PVA-H
C, PVA-203, PVA-205, PVA-21
0, PVA-217, PVA-220, PVA-22
4, PVA-217E, PVA-217EE, PVA-
220E, PVA-403, PVA-405, PVA-
420, PVA-420H, L-8, L-9, L-1
0, PVA-505, PVA-617, PVA-61
3, PVA-706 and the like, "Gohsenol" manufactured by Nippon Synthetic Chemical Industry Co., Ltd. NH-26, NH-20, NH-18, N
-300, NM-14, NM-11, NL-05, AH
-26, AH-22, AH-17, A-300, C-5
00, GH-23, GH-20, GH-17, GM-1
4, GM-14L, GL-05, GL-03, KH-2
0, KH-17, KM-11, KL-05, KP-0
8, KP-06 and the like are preferably used.

As the water-soluble resin in the present invention, a polyester resin containing at least one selected from the group consisting of a compound containing a sulfonate group and a compound containing a carboxylate group for facilitating water-solubility can be used. It is preferably used, and more preferably, a polyester resin obtained by copolymerizing at least one selected from a compound containing a sulfonic acid group and a compound containing a carboxylic acid group, preferably from 1 to 50 mol%, is used. Such a polyester resin can be used in a mixture with another water-soluble polymer.

Examples of the compound containing a sulfonate group include sulfoterephthalic acid, 5-sulfoisophthalic acid,
4-sulfoisophthalic acid, 4-sulfonaphthalene-2,
7-dicarboxylic acid, sulfo-p-xylene glycol,
Alkali metal salts such as 2-sulfo-1,4-bis (hydroxyethoxy) benzene, alkaline earth metal salts, ammonium salts, and the like can be used, but are not limited thereto. Examples of the compound containing a carboxylate group include trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, 4-methylcyclohexene-1,2,3-tricarboxylic acid, trimesic acid, 1,2,2 3,4-butanetetracarboxylic acid, 1,
2,3,4-pentanetetracarboxylic acid, 3,3 ′,
4,4'-benzophenonetetracarboxylic acid, 5-
(2,5-dioxotetrahydrofurfuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid, 5
-(2,5-dioxotetrahydrofurfuryl) -3-
Cyclohexene-1,2-dicarboxylic acid, cyclopentanetetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, ethylene glycol bistrimellitate, 2,
Alkali metal salts such as 2 ', 3,3'-diphenyltetracarboxylic acid, thiophene-2,3,4,5-tetracarboxylic acid and ethylenetetracarboxylic acid, alkaline earth metal salts, ammonium salts and the like can be used. Yes, but not limited to this.

As the easily soluble resin of the present invention, a resin mainly composed of polyhydroxycarboxylic acid may be used. As polyhydroxycarboxylic acids, L-lactic acid, D-lactic acid,
Glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 3-hydroxyvaleric acid, 4-hydroxyvaleric acid, 6
Polymers such as -hydroxycaproic acid and copolymers thereof can be used. Among them, lactic acid homopolymer (polylactic acid), a copolymer of lactic acid and another hydroxycarboxylic acid, or a mixture thereof is particularly preferable in terms of easy removal of the curable silicone resin film. preferable.

The easily soluble resin may contain a dicarboxylic acid or glycol as long as the effect of the present invention is not impaired. The mixture of the lactic acid component and other components has a content of the lactic acid component in the easily soluble resin of 50 mo.
It is preferable to use them in various combinations so as to be 1% or more.

The thickness of the easily soluble resin layer of the present invention is as follows:
It is preferably from 0.01 to 10 μm, more preferably from 0.05 to 5 μm, from the viewpoint of easy dissolution in water or other solvents in the recovery step.

The material for forming the release layer in the release film of the present invention is not particularly limited as long as it has a release property, and a material mainly composed of a curable silicone resin or urethane It may be a modified silicone resin or the like by graft polymerization with a resin, an epoxy resin, or the like. Among them, those having a curable silicone resin as a main component are more preferably used in terms of the releasability of the ceramic green sheet.

Examples of the curable silicone resin include any of a solvent addition type, a solvent condensation type, a solvent ultraviolet curing type, a solventless addition type, a solventless condensation type, a solventless ultraviolet curing type, and a solventless electron beam curing type. Reaction types can also be used. Specifically, Toray Dow Corning Silicone's LTC750A, LTC300B, SD7223,
YSR-3022, TPR-670 manufactured by Toshiba Silicone Co., Ltd., such as SD7226, SD7229, SRX-210, etc.
0, TPR-6720, TPR-6721, etc., KS-774, KS-775, KS-77 manufactured by Shin-Etsu Chemical Co., Ltd.
8, KS-779H, KS-856, X-62-242
2, X-62-2461, KNS-305, KNS-3
000, X-62-1256 and the like are preferably used.

The coating amount of the release layer is preferably in the range of 0.01 to 10 g / m ² from the viewpoint of releasability as green sheet, more preferably 0.05-5 g / m ² is there.

The release film of the present invention has an intermediate layer made of a readily soluble resin formed on at least one surface of the base film, and a release layer formed on the intermediate layer. By using a release film with an intermediate layer made of an easily soluble resin, for the first time, by immersing the release film after use in a solvent in which the easily soluble resin can be dissolved,
The easily soluble resin can be dissolved in the solvent, and the release layer on the film surface can be completely separated and removed, so that only the base film can be separated and collected.

In the case where the release layer is directly formed on the surface of the base film without the interposition of the easily soluble resin layer, the release layer cannot be completely separated and removed from the film surface. It is not preferable because only a clean base film cannot be recovered alone.

That is, by using a release film with an easily soluble resin layer interposed therebetween as in the present invention, it is possible to completely separate and remove the base film and the release layer for the first time, and to clean In addition to being able to separate and recover only the base film, the recovered film can be reproduced.

Next, an example of the method for collecting a release film of the present invention will be described by taking a release film of a multilayer ceramic capacitor as an example.

The release film according to the present invention is obtained by interposing a layer composed of the above-mentioned easily soluble resin between the base film and the release layer. Using such a release film, for example, to produce a multilayer ceramic capacitor, first, on the release layer surface of the release film,
The ceramic slurry is applied, and then dried to remove the solvent in the slurry to produce a green sheet.

Next, after printing and drying the internal electrode pattern with the conductive paste on the produced green sheet, the green sheet is peeled off from the release film. The peeled green sheet is cut into a predetermined shape, suctioned by a suction head, and placed on a lower mold of a press machine that performs temporary pressure bonding,
The required number of sheets are thermocompressed.

The thus obtained laminated body is cut into chips in such a manner that the internal electrodes are exposed at the end faces, and this is placed in a firing furnace and fired. The laminated body sintered through the firing process
A conductive paste is applied to the exposed end faces of the internal electrodes to form external electrodes, thereby obtaining a multilayer ceramic capacitor.

In order to collect the release film used in the above steps, after releasing the green sheet, the release film is wound up once, and the wound up release film is removed from the easily soluble resin. Is achieved by immersing in a solvent capable of dissolving and washing.

That is, the used release film is immersed in a solvent in which the easily soluble resin can be dissolved and washed, so that the easily soluble resin formed between the base film and the release layer is removed. Dissolves in the solvent, whereby the release layer is separated from the substrate film. By taking out the substrate film from which the release layer has been separated out of the solvent solution and drying it, only a clean substrate film can be recovered.

The method of immersing and cleaning the release film is not particularly limited. However, if the release film is wound in a roll, the release film is released from the unwinding device installed at the front of the bath filled with the solvent. The film is unwound and guided into a solvent bath for immersion. Next, the release film is washed in the bathtub while being transported by a transport roll provided in the bathtub,
The film is guided to a tunnel-type oven, dried, and can be continuously collected by winding a clean substrate film by a winding device installed at an outlet of the oven.

In this case, a cleaning effect can be further enhanced by arranging a brush or the like at a position in contact with the transport roll and mechanically rubbing the release layer surface side of the release film. It is also preferable to spray high-pressure water such as a jet stream on the release layer surface of the release film because the cleaning effect can be enhanced. The solvent in the bathtub can be removed by filtering the release layer components and other impurities dissolved in the bathtub by circulating the filtration device.

If the release film has been cut, the release film is put into a washing layer provided with a stirring device, washed with stirring, and then scooped up with a wire mesh of a belt conveyor system. , Lead to the tunnel oven,
By drying, a clean substrate film can be continuously collected.

The solvent used for washing is not particularly limited as long as it can dissolve the easily soluble resin. If the easily soluble resin is a water-soluble resin, water can be used. The load can be reduced. In this case, a surfactant or the like may be added to water in order to improve the wettability with the base film. The water used may be at room temperature, but is preferably used in the state of warm water or hot water at 50 ° C. to 80 ° C. in order to enhance the solubility.

If the easily soluble resin is a resin mainly composed of polyhydroxycarboxylic acid, an organic solvent such as N-methyl-2-pidridone, chloroform, methylene chloride and trichlene can be used. When the polyhydroxycarboxylic acid is polylactic acid, it can be easily dissolved by dipping in an alkaline solution such as an aqueous solution of caustic soda.

[0037]

The embodiments of the present invention will be described below with reference to examples, but the present invention is not limited to these examples.

<Evaluation Method of Effect> (1) Recoverability The prepared release film was immersed in a solvent in which the easily meltable resin was soluble, washed, dried, and the solvent was removed to form a release layer. Polyester adhesive tape on the side (Nitto Denko Corporation)
No. 31B), and the degree of adhesion was determined as follows.

A tape was strongly adhered and hardly peeled, and a tape was weakly adhered. If the tape is weakly adhered, the release layer remains and is not suitable for collection. (2) Reproducibility The recovered base film was formed into chips, and the film was reproduced under a normal film-forming condition using a biaxial stretching film-forming machine.

When the film was formed normally and a transparent film was regenerated, the film was evaluated as ○. When the film was managed, the film was clouded or colored. The film was broken due to bubbles or the like. Those that could not be reproduced were marked as x. Δ and × are not suitable for practical use.

Example 1 (Preparation of release film) A polyethylene terephthalate film (Toray "Lumirror" T60,
(Thickness: 38 μm). One side of the film was coated with a 5% by weight aqueous solution of a polyvinyl alcohol resin (“Gohsenol” GH17, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) using a bar coater so that the thickness after drying was 0.5 μm. Dried at 120 ° C. in oven.

Next, a curable silicone resin (LTC-350B, manufactured by Dow Corning Toray Silicone Co., Ltd., a curing agent SRX-2) was applied on the polyvinyl alcohol resin layer.
The 5% by weight toluene solution of 12) was coated with a bar coater, heated at 100 ° C. in a tunnel oven to form a release film, and wound up. (Preparation of ceramic green sheet) A ceramic slurry having the following composition was uniformly applied on the release layer surface of the release film, and dried at 85 ° C in a tunnel oven to prepare a 20 μm thick ceramic green sheet. And wound it up. << Ceramic slurry composition >> 100 parts of ceramic powder (barium titanate) 10 parts of binder (acrylic polymer) 10 parts of the above composition in toluene / isopropyl alcohol (compounding ratio of 1: 1), and the viscosity of the slurry is 300 to 500 c.
Diluted to ps. (Recovery of release film) While peeling the above-mentioned ceramic green sheet from the release film, winding up only the release film, guiding the rolled-up release film into a water bath at 25 ° C, and transporting the inside of the bathtub. The surface of the release layer was washed by brushing with a roll-shaped brush. The washed film was further guided into a tunnel oven, and dried at 120 ° C., and the substrate film was continuously collected at the outlet of the oven.

When a polyester adhesive tape (Nitto Denko Corporation No. 31B) was adhered to the release layer surface side of the base film, it adhered strongly and was not easily peeled off, and the release layer was separated and removed. Was confirmed. (Re-formation) The collected base film was pulverized into chips and formed into a film by a biaxial stretching film forming machine. As a result, a colorless and transparent polyester film could be regenerated.

Example 2 (Preparation of release film) In Example 1, a water-soluble polyester resin coating liquid obtained by copolymerizing a compound containing a sulfonate group having the following composition was used in place of the polyvinyl alcohol resin. In the same manner as in Example 1, a release film was produced.

<< Water-soluble polyester resin composition >> 30 parts by weight of polyester resin A ・ Acid component 50 mol% of terephthalic acid 25 mol% of sebacic acid 24 mol% 5 mol of 5-sodium sulfoisophthalic acid ・ glycol component 55 mol of ethylene glycol % Neopentyl glycol 45 mol% polyester resin B 70 parts by weight ・ acid component terephthalic acid 87.5 mol% 5-sodium sulfoisophthalic acid 12.5 mol% ・ glycol component ethylene glycol 100 mol% so as to have the above solid content ratio It was mixed and diluted with water to a solid concentration of 5% by weight. (Preparation of Ceramic Green Sheet) In the same manner as in Example 1, a ceramic green sheet was prepared. (Recovery of release film) While releasing the ceramic green sheet from the release film, only the release film is wound up, and the rolled-up release film is guided into a hot water bath at 70 ° C. while being transported in the bathtub. The surface of the release layer was washed by brushing with a roll-shaped brush. The film after washing was further guided to a tunnel oven, and dried at 120 ° C., while continuously collecting the substrate film at the outlet of the oven.

When a polyester pressure-sensitive adhesive tape (Nitto Denko Corporation No. 31B) was attached to the release layer side of the base film, it adhered strongly and did not peel off easily, and the release layer was separated and removed. Was confirmed. (Re-formation) The collected base film was pulverized into chips and formed into a film by a biaxial stretching film forming machine. As a result, a colorless and transparent polyester film could be regenerated.

Example 3 (Preparation of Polylactic Acid Pellets) 100 parts by weight of L-lactic acid polymer synthesized from 80 parts by weight of L-lactic acid and 20 parts by weight of hydroxycarboxylic acid were mixed with 0.1 part of calcium carbonate particles having an average particle size of 1.5 μm. After adding and mixing 5 parts by weight, the mixture was supplied to a twin-screw extruder having a different rotation direction and extruded at 200 ° C. to form a pellet. The obtained pellet was treated at 50 ° C. under reduced pressure for crystallization and drying. (Preparation of coating solution of polylactic acid polymer) The above-mentioned polylactic acid pellets were dissolved by stirring at a temperature of 60 ° C using N-methyl-2-pyrrolidone as a solvent to prepare a coating solution having a concentration of 5% by weight. (Preparation of Release Film) A release film was prepared in the same manner as in Example 1 except that the above-mentioned polylactic acid polymer coating solution was used instead of the polyvinyl alcohol resin. (Preparation of Ceramic Green Sheet) In the same manner as in Example 1, a ceramic green sheet was prepared. (Recovery of release film) While releasing the ceramic green sheet from the release film, only the release film was wound up, and the wound release film was washed with N-methyl-2 at 60 ° C.
-Introduced into the pyrrolidone bath, while being transported in the bathtub, the release layer surface was washed by brushing with a roll-shaped brush. The washed film is further guided to a tunnel oven and
The substrate film was continuously collected at the outlet of the oven while drying at ℃.

When a polyester pressure-sensitive adhesive tape (Nitto Denko Corporation No. 31B) was adhered to the release layer side of the base film, it adhered strongly and did not peel off easily, and the release layer was separated and removed. Was confirmed. (Re-formation) The collected base film was pulverized into chips and formed into a film by a biaxial stretching film forming machine. As a result, a colorless and transparent polyester film could be regenerated.

Comparative Example 1 (Preparation of Release Film) In Example 1, a release film was prepared by coating only a curable silicone resin without coating a polyvinyl alcohol resin. (Preparation of Ceramic Green Sheet) In the same manner as in Example 1, a ceramic green sheet was prepared. (Recovery of release film) While releasing the ceramic green sheet from the release film, only the release film is wound up, and the rolled-up release film is guided into a hot water bath at 70 ° C. while being transported in the bathtub. The surface of the release layer was washed by brushing with a roll-shaped brush. The film after washing was further guided to a tunnel oven, and dried at 120 ° C., while continuously collecting the substrate film at the outlet of the oven.

When a polyester pressure-sensitive adhesive tape (Nitto Denko Corporation No. 31B) was attached to the release layer side of the film, it did not stick at all, and it was confirmed that the release layer was not removed. (Re-formation) When the above-mentioned film was pulverized into chips and formed into a film by a biaxial stretching film-forming machine, bubbles were mixed in the molten polymer and the film was frequently broken in the stretching step. The obtained film was also cloudy, and a normal reproduced film was not obtained.

[0051]

[Table 1]

As shown in Table 1, according to the recovery method of Examples 1, 2, and 3, the release film after the green sheet was peeled off was placed in water, hot water, or an N-methyl-2-pyrrolidone bath. By immersion and washing, the release layer on the release film surface can be easily separated and removed together with the dissolution of the easily soluble resin, so that only a clean substrate film can be easily collected. On the other hand, Comparative Example 1
In the method of recovery, the release layer could not be separated and was not suitable for recovery.

[0053]

According to the present invention, since the release layer formed on the film surface can be easily separated and removed, only the clean substrate film can be collected without discarding the used release film. Can be. In addition, by forming the collected film into chips and re-forming the film, a colorless and transparent biaxially stretched film can be regenerated and reused.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C08L 33:04 C08L 33:04 67:00 67:00 F term (Reference) 4F100 AK01A AK01B AK21B AK25B AK41B AK41J AK42A AK51B AK51J AK52C AK69B AK70B AL01B AR00C BA03 BA07 BA10A BA10C GB41 GB90 JB08B JB09B JB12C JL14C JL16 JM01B 4F301 AA19 AA20 AA25 CA09 CA12

Claims (12)

[Claims] 1. A release film having a release layer formed on at least one side of a base film via a readily soluble resin layer, and the release film after use can be dissolved by the easily soluble resin. A method for recovering a release film, comprising: immersing in a solvent and dissolving the easily soluble resin in the solvent, thereby separating and removing the release layer on the film surface, and recovering only the base film. . 2. The method according to claim 1, wherein the easily soluble resin is a water-soluble or water-dispersible resin. 3. The easily soluble resin is at least one selected from a polyester resin, a polyester urethane resin, an acrylic resin, an ethylene ionomer resin, a polyvinyl alcohol resin and an ethylene-vinyl alcohol resin. The method for collecting a release film according to claim 1 or 2, wherein 4. The method according to claim 3, wherein the polyvinyl alcohol resin is polyvinyl alcohol. 5. The resin according to claim 1, wherein the easily soluble resin comprises at least one selected from a compound containing at least a hydroxyl group, a compound containing a carboxyl group, a compound containing a sulfonate group and a compound containing a carboxylate group. The method for collecting a release film according to any one of claims 1 to 3, wherein: 6. The water-soluble polyester resin, wherein the easily soluble resin is at least one selected from the group consisting of a compound containing at least a sulfonate group and a compound containing a carboxylate group. Claim 1
3. The method for collecting a release film according to any one of items 3 and 5. 7. The method for recovering a release film according to claim 1, wherein said easily soluble resin is a resin mainly composed of polyhydroxycarboxylic acid. 8. The method according to claim 1, wherein the easily soluble resin layer has a thickness of 0.01 to 10 μm.
2. The device according to claim 1, wherein the thickness of the first member is about m.
8. The method for collecting a release film according to any one of items 1 to 7. 9. The method according to claim 1, wherein the base film is a polyester film containing polyethylene terephthalate as a main component. 10. The method according to claim 1, wherein the release layer is a curable silicone resin. 11. The method for recovering a release film according to claim 1, wherein the release film is a film for an electronic component manufacturing process or an adhesive release paper. 12. The film for a process of manufacturing an electronic component according to claim 12,
The method for collecting a release film according to claim 11, which is a release film for a ceramic green sheet.