JP6989052B2 - Separation and recovery method of laminated film and laminated film - Google Patents

Description

The present invention relates to a method for recycling a resin film having a printed layer.

Conventionally, due to the mandatory recycling of plastic containers and packaging, the collection, separation and reuse of plastic waste including those for food packaging have been carried out.
There are various types of plastic waste, such as those made of synthetic resins such as polyethylene, polypropylene, polystyrene (Styrofoam), polyethylene terephthalate, and polyvinyl chloride, and metal foils such as these synthetic resin films and aluminum foils are laminated. , A lot of laminated films with the display of the product name etc. and decorativeness with printing ink are also included, and these are in a mixed state at the time of collecting dust.

As a laminated film, a laminated film in which a plurality of layers of films made of different types of thermoplastic resins are laminated using a plurality of extruders is known, and a device for separating the laminated film into a single-layer film of each layer has also been developed (a device for separating the laminated film into a single-layer film of each layer). For example, see Patent Document 1).
On the other hand, a laminated film having a printing layer, for example, a laminated film in which a film made of a plurality of thermoplastic resins is laminated, or a film surface made of one type of resin is provided with a printing layer, and the printed layer is exposed (front printing). After providing a printing layer on a film, a laminated film in which a film made of a plurality of thermoplastic resins is laminated, or a film made of one type of resin, another film is laminated and laminated via an adhesive layer. That is, when a laminated film in which a printing layer is provided between a plurality of films (back printing) is mixed as dust, recycling is not easy. If the film printed with these printing inks is directly advanced to the recycling process, the pigment component, which is a colorant, is not decomposed even with the high heat applied in the recycling process, and the entire recycled resin is colored in a grass color in which various colors are mixed. It will significantly reduce the commercial value of the product.
Further, the adhesive used for the laminated film having a backprint printing layer is often a thermosetting type reactive adhesive, that is, the adhesive layer forms a strong crosslinked layer, and is therefore disclosed in Patent Document 1. It cannot be easily separated by a separation device such as the one described above.
As described above, the film printed and laminated with different materials cannot be used as a recycled product even if it is collected as waste plastic, and is incinerated as fuel in most cases.

In order to solve the above-mentioned problems, studies are underway to remove the printing ink or separate and collect the laminated film and proceed to the recycling process. Patent Documents 2 to 4 are known as a device for inserting a release layer for separation and recovery into a base material and a printing layer, and Patent Documents 5 to 9 are known as a device for inserting a release component into an ink or an adhesive. There is.
However, in these studies, a highly oxidized resin such as fumaric acid and phthalic acid is used as the peeling layer, and an alkaline solution is used as the peeling solvent, and it is necessary to wash away the neutralizing step and the alkaline component before the recycling step. .. In addition, handling of alkaline solutions and waste liquid treatment are costly and impractical.

Japanese Patent Application Laid-Open No. 2002-96327 Japanese Unexamined Patent Publication No. 2000-313085 Japanese Unexamined Patent Publication No. 2001-131484 Japanese Unexamined Patent Publication No. 2017-114930 Japanese Unexamined Patent Publication No. 2000-313833 Japanese Unexamined Patent Publication No. 11-209677 Japanese Unexamined Patent Publication No. 2001-031899 Japanese Unexamined Patent Publication No. 2000-086951 Japanese Patent Application Laid-Open No. 2002-32024

An object to be solved by the present invention is to provide a laminated film and a method for separating and recovering a laminated film that can be separated and removed only with water in a method of treating composite waste and separating and recovering each component.

The present inventors have solved the above-mentioned problems by providing a resin layer containing polyvinyl alcohol (hereinafter sometimes referred to as PVA) as an ink desorption layer between the resin film and the printing layer.

In the case of a laminated film having a front print layer, the PVA of the release layer swells in water and loses adhesion to the resin film and is detached from the resin film. After that, PVA is completely dissolved in water, so that the ink film is suspended in the water. On the other hand, in the case of a laminated film having a backprint printing layer, PVA quickly swells in water and peels off, PVA completely dissolves after a certain period of time, and the ink + adhesive layer floats in the peeling liquid in a film state. It will be in the state of being. In the present invention, the above-mentioned problems are solved by recovering the separated film.

That is, the present invention provides a laminated film in which a resin layer containing polyvinyl alcohol is provided between a resin film and a printing layer printed with printing ink.

The present invention also provides a method for separating and recovering a laminated film, which comprises a step 1 of immersing the laminated film in water at 20 to 50 ° C. and a step 2 of recovering the single-layer film of each separated layer.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to obtain a laminated film and a method for separating and recovering a laminated film that can be separated and removed only with water.

(Laminated film)
The laminated film of the present invention is a laminated film characterized in that a resin layer containing polyvinyl alcohol is provided between a resin film and a printing layer printed with a printing ink.
In the present invention, the (resin) film refers to a film obtained by molding a polymer component such as a synthetic resin (plastic) into a thin film, and the laminated film includes at least one layer of the film and is laminated with another thin film. Refers to the thing. The structure of the laminated film will be described later, but for example, a laminated film in which two plastic films are laminated with an adhesive, a laminated film in which one plastic film and one metal foil are laminated with an adhesive, and one plastic film. Examples thereof include a laminated film in which one piece of paper is laminated with an adhesive.

(Resin film)
In the present invention, the resin film is not particularly limited, and a thermoplastic resin film commercially available and used for food packaging and daily necessities can be used. For example, polyolefin films such as low density polyethylene, high density polyethylene, linear low density polyethylene, OPP (biaxially stretched polypropylene), CPP (non-stretched polypropylene); polyester films such as polyethylene terephthalate (PET) and polybutylene terephthalate. Polyamide-based film such as nylon 6, nylon 6,6, metaxylene adipamide (N-MXD6); biodegradable film such as polylactic acid; polyacrylonitrile-based film; poly (meth) acrylic-based film; polystyrene-based film Polycarbonate-based film; Ethylene-vinyl acetate copolymer saponified (EVOH) -based film; Polyvinyl alcohol-based film; Polyvinylidene chloride, ionomer resin, EAA resin, EMAA resin, EMA resin, EMMA resin, biodegradable resin film, etc. However, it is not limited to this. Generic names include CPP (unstretched polypropylene) film, VMCPP (aluminum vapor-deposited unstretched polypropylene film), LLDPE (linear low-density polyethylene), LDPE (low-density polyethylene), HDPE (high-density polyethylene), VMLDPE (aluminum-deposited). Non-low density polyethylene film) film, film containing these pigments and the like can be mentioned.
The surface of the film may be subjected to various surface treatments such as flame treatment, corona discharge treatment, or chemical treatment such as a primer.

(Printing ink, printing layer)
In the present invention, the print layer printed with the printing ink may be known without particular limitation. For example, a printing layer printed with a flat plate offset printing ink using a plate, a gravure printing ink, a flexographic printing ink, an inkjet printing ink not using a plate, and the like can be mentioned. Gravure printing inks and flexographic printing inks are the most common printing inks for food packaging films that can be plastic waste such as those for food packaging. Here, this general composition will be described as an example by taking a gravure printing ink and a flexographic printing ink as an example.

Printing inks such as gravure printing inks and flexographic printing inks include binder resins, colorants, solvents such as organic solvents and aqueous solvents, and additives.
The binder resin includes cell roll resin such as vitrified cotton, urethane resin, polyamide resin, vinyl chloride / vinyl acetate copolymer, rosin resin and its modified products, ketone resin, cellulose resin, polyester resin, and (meth) acrylic. Examples thereof include resins, and these can be used in combination as appropriate. Of these, cellulosic resins such as vitrified cotton, urethane resins, polyamide resins, vinyl chloride / vinyl acetate copolymers and the like are often used in appropriate combinations.

Examples of the colorant include organic and inorganic pigments and dyes used in general inks, paints, recording agents and the like. Examples of organic pigments include azo-based, phthalocyanine-based, anthraquinone-based, perylene-based, perinone-based, quinacridone-based, thioindigo-based, dioxazine-based, isoindolinone-based, quinophthalone-based, azomethine-azo-based, dictopyrrolopyrrole-based, and isoindoline-based. Pigments are mentioned, and examples of inorganic pigments include carbon black, titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, silica, red iron oxide, aluminum, and mica (mica). Further, a brilliant pigment (Metashine; Nippon Sheet Glass Co., Ltd.) in which glass flakes or lumpy flakes are used as a base material and coated with a metal or a metal oxide can be mentioned.

If the solvent is an organic solvent, for example, an aromatic organic solvent, a ketone solvent such as acetone, methyl ethyl ketone, or methyl isobutyl ketone, an ester solvent such as ethyl acetate, n-propyl acetate, butyl acetate, or propylene glycol monomethyl ether acetate, Examples thereof include alcohol solvents such as n-propanol, inopropanol, n-butanol, and propylene glycol monomethyl ether. Further, as an aqueous solvent, a solvent in which water is a main component and a water-soluble alcohol-based solvent or the like is mixed can be mentioned.

Examples of the additive include extender pigments, pigment dispersants, leveling agents, defoaming agents, waxes, plasticizers, blocking inhibitors, infrared absorbers, ultraviolet absorbers, fragrances, flame retardants and the like.
In addition, there are some that further add a cross-linking agent or a chelating agent to cross-link the printing ink layer itself to increase the hardness.

Further, a printing ink to which a resin having an acidic group or a small molecule compound is added can also be preferably used. The resin or low molecular weight compound having an acidic group can be easily mixed with the binder resin or organic solvent which is the main component of the printing ink, and any resin or low molecular weight compound having an acid value can be used without particular limitation. Can be done.

Examples of the resin having an acidic group include a resin having an acid value such as a rosin-modified maleic acid resin and a rosin-modified fumaric acid resin; Polymerization having an acidic group such as a polymerizable monomer having a carboxyl group such as an acid anhydride, a polymerizable monomer having a sulfonic acid group such as sulfonated styrene, and a polymerizable monomer having a sulfonamide group such as vinylbenzenesulfonamide. Resins that are radical copolymers such as (meth) acrylic resin, styrene- (meth) acrylic resin, styrene- (anhydrous) maleic acid resin, and terpene- (anhydrous) maleic acid resin, which are copolymerized with a sex monomer; Examples thereof include acid-modified polyolefin resin, which can be used alone or in admixture of a plurality.

Examples of the low molecular weight compound having an acidic group include saturated fatty acids, unsaturated fatty acids, hydroxy acids, aromatic carboxylic acids, dicarboxylic acids, tricarboxylic acids, oxocarboxylic acids, carboxylic acid derivatives, acid anhydrides and the like. Can be used alone or in admixture.

Examples of saturated fatty acids include lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, unsaturated fatty acids, oleic acid, linoleic acid, linolenic acid, arachidonic acid, eikosapentaenoic acid, docosahexaenoic acid, sorbic acid and the like. Examples of hydroxy acids include lactic acid, malic acid, citric acid, etc., and aromatic carboxylic acids include benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, gallic acid, melitonic acid, and silica skin. Examples of the dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, maleic acid and the like, and examples of the tricarboxylic acid include aconitic acid and oxocarboxylic acid. Examples thereof include pyruvate and oxaloacetate, examples of the carboxylic acid derivative include amino acids and nitrocarboxylic acids, and examples of acid anhydrides include trimellitic anhydride and pyromellitic anhydride. It can be used alone or in admixture.

The acid value of the compound having an acidic group is not particularly limited, but is preferably 150 mgKOH / g or more.

The resin or small molecule compound having an acidic group preferably has at least one of a glass transition point, a softening point, and a melting point of 100 ° C. or higher.

The printing ink preferably contains the resin having an acidic group or a small molecule compound. The amount to be added may be appropriately determined within a range that does not impair the printability of the printing ink, but is preferably in the range of 0.5 to 50% by weight with respect to the solid content of the printing ink, and more preferably 1. It is in the range of 0 to 30% by weight.

In the printing ink, a mixture to which a pigment, an aqueous medium, a dispersant, a defoaming agent and the like are added in advance is dispersed by a disperser to obtain a pigment dispersion. It can be obtained by adding an additive such as the copolymer, an aqueous medium, and if necessary, a leveling agent to the obtained pigment dispersion, and stirring and mixing the mixture.
As the disperser, it is manufactured by using a bead mill, an Eiger mill, a sand mill, a gamma mill, an attritor, etc., which are generally used for manufacturing gravure and flexographic printing inks.

(Resin layer containing polyvinyl alcohol)
In the present invention, the polyvinyl alcohol-containing resin layer provided between the resin film and the printing layer printed with the printing ink is specifically a resin layer containing at least 25% by mass of polyvinyl alcohol. Hereinafter, the resin layer containing polyvinyl alcohol may be referred to as a PVA resin layer.

Polyvinyl alcohol is a colorless powder obtained by saponifying polyvinyl acetate. It is a water-soluble thermoplastic resin that is used as a water-soluble packaging material, adhesive, emulsifier, etc., and is a raw material for synthetic fiber vinylon. Generally, it may be abbreviated as Poval or PVA. Examples of commercially available products include Kuraray's Poval, Elvanol, and Exeval, Mitsubishi Chemical's Gosenol, and Japan Vam & Poval.

The degree of saponification of polyvinyl alcohol is determined by the ratio of the vinyl group of polyvinyl acetate substituted with a hydroxyl group, and the degree of saponification is preferably 90% or more. Examples of polyvinyl alcohol having a saponification degree of 90% or more include, but are not limited to, the following commercially available products.
Kuraray Poval "3-98, 5-98, 28-98, 60-98, 27-96", Kuraray Elvanol "71-30, 90-50, T-25, T-66", Kuraray Excell "AQ-4104, HR-3010, RS-2117, RS-1717", Mitsubishi Chemical Co., Ltd. Gosenol "N-300, NL-05, A-300, AL-06R", Japan Vam & Poval Co., Ltd. "JC-25" , JC-33, JC-40, JF-02, JF-03, JF-04, JF-05, JF-10, JF-17, JF-17L, JF-22, JM-17, JM-17L, JM -23, JM-26, JM-33, JT-05, JT-13Y "etc.

(Structure of laminated film)
Specifically, the configuration of the laminated film of the present invention is
(1) A laminated film (1) having a resin film (A), a PVA resin layer, and a printing layer on which printing ink is printed in this order.
(2) A laminated film (2) having a resin film (A), a PVA resin layer, a printing layer on which printing ink is printed, an adhesive layer, and a resin film (B) in this order.
In any case, the printing layer and the resin film layer can be separated and recovered with water.

(Laminated film (1))
In the laminated film 1, the above-mentioned thermoplastic resin film may be used as the thermoplastic resin film used for the resin film (A), and among them, for example, low density polyethylene, high density polyethylene, linear low density. Polyethylene-based films such as polyethylene, OPP (biaxially stretched polypropylene), CPP (non-stretched polypropylene); polyester-based films such as polyethylene terephthalate (PET) and polybutylene terephthalate; nylon 6, nylon 6,6, methaxylene adipamide Polyamide-based film such as (N-MXD6); Biodegradable film such as polylactic acid; Polyacrylonitrile-based film; Poly (meth) acrylic-based film; Polystyrene-based film; Polycarbonate-based film; Ethylene-vinyl acetate copolymer Kensei (EVOH) -based film; polyvinyl alcohol-based film; K-coat such as polyvinylidene chloride, etc. are often used. A transparent vapor-deposited film in which alumina or silica is vapor-deposited on these films may also be used.
Further, the surface of the film material may be subjected to various surface treatments such as flame treatment, corona discharge treatment, or chemical treatment such as a primer.

The method for providing the PVA resin layer on the resin film (A) is not particularly limited. For example, a solution containing polyvinyl alcohol is prepared with an appropriate solvent, and the solution is applied to the resin film (A) and dried. There is a way to do it. The coating amount is about 0.1 to 5 um (dry thickness), but if it is less than 0.1, it is difficult to apply it uniformly, and if it exceeds 5 um, it is uneconomical and therefore not practical. For the coating, a usual coating method, for example, gravure, letterpress, flexo, roll coater, reverse coater, spray method and the like is used. The formation of the primer layer and the printing on the primer layer may be continuous (in-line), or the formation of the primer layer and the printing may be performed separately.

When printing is performed immediately after coating the PVA resin layer in-line using a printing machine such as roll-to-roll, so-called blocking occurs in which the printed surface sticks to the back surface of the substrate in some cases. In order to prevent such blocking, transparent particles having a particle size of 0.1 um to 10 um such as silica and titanium oxide are mixed in the PVA solution in an amount of about 0.005 to 5% with respect to the total amount of the PVA solution. Is also good.

As a method of providing the printing layer on the PVA resin layer, a known printing method can be used without particular limitation. For example, a printing layer can be obtained by applying ink to a base material using a gravure method or a flexographic printing method, drying the ink by drying in an oven, and fixing the ink. The drying temperature is usually about 40 to 60 ° C.

(Laminated film (2))
In the laminated film (2), the resin film (A) to be used, the PVA resin layer, and the printing layer on which the printing ink is printed may be provided by using the same resin film (1) as described above. can.

The adhesive layer used in the laminated film (2) is not particularly limited, and a general-purpose one-component adhesive, two-component adhesive or the like can be used. Further, it may be a reactive adhesive or a non-reactive adhesive. The reactive adhesive is not particularly limited and can be separated and recovered if it is a commercially available reactive adhesive. Among them, a so-called two-component type of a polyisocyanate composition and a polyol composition, or a one-component of a polyisocyanate composition. It is particularly effective and preferable for type-reactive adhesives.

The resin film (2) is currently most often used for food packaging and daily necessities. At least two resin film layers are laminated with an adhesive, and a printing layer exists between the laminated layers. .. Further, an adhesive layer made of the reactive adhesive may be laminated between the metal foil or the vapor-deposited film layer.
Specifically, in the laminated film, the resin film layer is expressed as (F), the printed layer is expressed as (P), and the metal foil or the metal foil layer of the vapor-deposited film layer is expressed as (M). When the adhesive layer such as a reactive adhesive is expressed as (AD), the following configuration can be considered as a specific embodiment of the laminated film, but of course, the present invention is not limited to this.

(F) / (P) / (AD) / (F),
(F) / (P) / (AD) / (F) / (AD) / (F),
(F) / (P) / (AD) / (M) / (AD) / (F),
(F) / (P) / (AD) / (M),
(F) / (P) / (AD) / (F) / (AD) / (M) / (AD) / (F),
(F) / (P) / (AD) / (M) / (AD) / (F) / (AD) / (F),
(M) / (P) / (AD) / (M),
(M) / (P) / (AD) / (F) / (AD) / (M),
(AD) / (P) / (F) / (AD) / (M),
(AD) / (P) / (F) / (AD) / (F) / (AD), etc.
The laminated film (2), which is the target of this separation / recovery method, may further have a paper layer, an oxygen absorbing layer, an anchor coat layer, a printing layer, and the like.

When classified according to the required role, the resin film layer (F) functions as a base film layer (F1), a sealant layer (F2) serving as a heat-sealing portion when forming a packaging material, and the like.
The base film layer (F1) corresponds to the resin film (A). As the resin film (A), the same resin film (1) as the resin film (1) can be used as described above.

The sealant layer (F2) corresponds to the resin film (B). Examples of the flexible polymer film to be the resin film (B) include polyethylene films, polypropylene films, polyolefin films such as ethylene-vinyl acetate copolymers, ionomer resins, EAA resins, EMAA resins, EMA resins, EMMA resins, and raw materials. A film made of a decomposed resin or the like is preferable. Generic names include CPP (unstretched polypropylene) film, VMCPP (aluminum vapor-deposited unstretched polypropylene film), LLDPE (linear low-density polyethylene), LDPE (low-density polyethylene), HDPE (high-density polyethylene), VMLDPE (aluminum-deposited). Non-low density polyethylene film) film, film containing these pigments and the like can be mentioned. The surface of the film may be subjected to various surface treatments such as flame treatment, corona discharge treatment, or chemical treatment such as a primer.

Examples of the metal foil layer (M) include foils of metals having excellent spreadability, such as gold, silver, copper, zinc, iron, lead, tin and alloys thereof, steel, stainless steel, and aluminum.

Examples of the paper layer include natural paper and synthetic paper. The first and second sealant layers may be made of the same material as the above-mentioned sealant layer.

The "other layer" may include known additives and stabilizers such as antistatic agents, non-reactive adhesive layers, easy-adhesive coatings, plasticizers, lubricants, antioxidants and the like.

(Separation and recovery method of laminated film)
The separation and recovery method of the present invention is characterized by having a step 1 of immersing the laminated film in water at 20 to 50 ° C. and a step 2 of recovering the separated film.

(Step 1)
The water used in step 1 is not particularly limited and may be water at 20 to 50 ° C. This may be water obtained by various methods such as city water, reclaimed water, distilled water, and ion-exchanged water.

The time for immersing the laminated film in the water is generally in the range of 1 minute to 3 hours, although it depends on the structure of the laminated film. If the immersion time is less than 1 minute, the adhesive layer may not be completely peeled off from the laminated film and may partially remain.

In the step 1, the number of times of immersion in the water may be once or divided into several times. That is, the step 2 may be performed after the number of dipping times is performed once, and then the separated film is collected, or the step 2 may be performed after the number of dipping times is performed several times. Further, it is preferable to appropriately add a known step such as drying between the steps.

(Step 2)
In the water in the step 1, the separated single-layer film and the residue such as the reactive adhesive, the printing ink, and the metal foil are suspended or dissolved. After removing these from the stripping solution, they are separated and collected.
As an example of a specific method, for example, in levitation sorting, a plastic having a light specific gravity such as polyolefin such as polypropylene or polyethylene (floating material), a condensed synthetic film such as polyester or nylon having a heavier specific density than polyolefin, or a metal Heavy objects such as foils are sorted, heavy objects are removed, and then the plastics recovered in the washing and dehydrating step are washed and dehydrated, and the plastics having different specific densities are separated by centrifugation. For example, it can be divided into a plastic separated product containing a vinyl chloride resin having a specific gravity of 1 or more and polyethylene terephthalate, which is submerged in water, and a plastic separated product containing an olefin resin such as polyethylene or polypropylene, which does not contain the vinyl chloride resin.
Further separation is possible by changing the specific gravity by appropriately changing the mixing ratio of the liquid used for the floating separation, for example, water and the organic solvent.
Each separated product is solidified after drying and reused as a recycled product and as a recycled raw material for recycled plastic.

Hereinafter, the contents and effects of the present invention will be described in more detail with reference to Examples. In addition, the resin film, printing ink, and thermosetting adhesive used as raw materials in each Example and Comparative Example are shown below.

<Resin films 1, 2>
OPP: Biaxially stretched polypropylene film 20um
CPP: Unstretched polypropylene film 35um
<Printing ink>
INK1: DIC Graphics front printing ink Grossa BM709 white INK2: DIC Graphics back printing ink Finalt R794 White S
<Thermosetting adhesive>
AD1: Two-component solvent-free adhesive with NS5000 and HA500B manufactured by DIC India AD2: Two-component solvent-type adhesive with DIC Dick Dry LX-401A and SP-60 manufactured by DIC <resin layer>
Pri1: A stripping layer solution obtained by diluting Marquid # 31 (rosin maleated) manufactured by Arakawa Chemical Industry Co., Ltd. to 20% by mass with ethyl acetate. Peeling layer solution diluted to 10% by mass with water Pri3: Peeling layer solution obtained by diluting Kuraray's Excelval RS4104 (polyvinyl alcohol with a saponification degree of 90% or more) to 10% by mass with water.

<Manufacturing method of laminated film>
The laminated film was prepared by printing on the target film by the printing method and then laminating the target film by the laminating method. The layer structure of the film, the reactive adhesive, and the types of printing inks were determined by the combinations shown in Table 1.

<Printing method>
For gravure ink and flexo ink, which are printing inks, a film "resin film 1" in which each ink is previously coated with a primer "Pri1 to 3" using a proofer ^{so as to have a coating amount of 3 g / m 2 solid content.} The color was expanded to.

<Laminating method>
The reactive adhesives "AD1 and 2" were applied to the color-expanded surface of the printing ink of the film "resin film 1" on which the printing ink was spread with a laminator so that the solid content was 3 g / m ² . The primer "Pri1 to 3" was previously applied to the film "resin film 2" so as to have a coating amount of ^{3 g / m 2 solid content.}
The laminated film laminated was subjected to an aging reaction at 40 ° C. for 72 hours to obtain the laminated film "Film 1 to 6" shown in Table 1.

<Separation and recovery method of laminated film>
The laminated film "Film 1-9" was cut into a size of 10 mm × 10 mm to obtain a test piece. These test pieces were subjected to a peeling test in a separation and recovery step.
The separation and recovery step was carried out for 30 minutes with a stirring efficiency of 800 rpm by putting the test piece in tap water adjusted to 50 ° C. It should be noted that if the material is peeled off in 30 minutes of the stirring process, it shows that the performance is considerably high.
After the above step, the film was separated from the liquid by a filtration method, taken out, washed with water, and dried at 50 ° C. Then, the peeling state of the film was observed, and the peeling of the ink layer was visually observed.
Table 1 shows the layer structure and test results.

As a result, in the Films of Examples 1 to 3, since the resin layer 1 was water-soluble Pri2 or Pri3, the ink layer of the laminated film was peeled off.
In the Films of Examples 4 to 5, the ink layer of the laminated film was peeled off because the resin layer 2 was water-soluble Pri2 or Pri3.
In the Films of Comparative Examples 1 to 3, the ink layer of the laminated film was not peeled off because the water-insoluble Pri1 was used for the resin layer 1 or the resin layer 2.
In the film of Comparative Example 4, the ink layer of the laminated film was not peeled off because Pri1 which is the resin layer 1 used was water-insoluble.

Claims (6)

A laminated film in which a resin layer containing polyvinyl alcohol is provided between a resin film and a printing layer printed with printing ink.
The laminated film, a resin layer containing a tree fat film (A) and the polyvinyl alcohol, the printed layer and the heat-curable adhesive layer printing ink resin layer is printed and the resin film and (B) the laminated fill-time with the order
Laminate film is. The laminated film according to claim 1, further comprising a resin layer containing polyvinyl alcohol between the thermosetting adhesive layer and the resin film (B). The laminated film according to claim 1 or 2, wherein the polyvinyl alcohol has a saponification degree of 90% or more. Step 1 of immersing a laminated film in which a resin layer containing polyvinyl alcohol is provided between a resin film and a printing layer printed with printing ink in water at 20 to 50 ° C.
Possess a step 2 for collecting the separated the resin films,
The laminated film includes a resin film (A), a resin layer containing polyvinyl alcohol, a printing layer on which printing ink is printed, a thermosetting adhesive layer, and a resin film (B) in this order. A method for separating and recovering a laminated film, which is characterized by having a laminated film. The method for separating and recovering a laminated film according to claim 4 , wherein the resin film and the residue of the printing ink are suspended or dissolved in the water in the step 1. The method for separating and recovering a laminated film according to claim 4 or 5 , wherein the printing layer is peeled off from the resin film in the step 1.