METHOD FOR SEPARATING AND RECOVERING LAYERED FILM

Abstract

A method for separating and recovering a layered film laminated and adhered with an adhesive, the method including a step 1 of immersing the layered film in a morpholine solution having a morpholine concentration of 50% by mass or more while stirring the layered film with heating at 20° C. to 90° C. or ultrasonically vibrating the layered film and a step 2 of recovering separated single-layered films that constitute the respective layers of the layered film. The adhesive is preferably a reactive adhesive containing a polyisocyanate composition and a polyol composition.

Claims

1. A method for separating and recovering a layered film laminated and adhered with an adhesive, the method comprising: a step 1 of immersing the layered film in a morpholine solution haying a morpholine concentration of 50% by mass or more while stirring the layered film with heating at 20° C. to 90° C. or ultrasonically vibrating the layered film, and a step 2 of recovering separated single-layered films that constitute the respective layers of the layered film.

2. The method for separating and recovering a layered film according to claim 1, wherein the adhesive is a reactive adhesive containing a polyisocyanate composition and a polyol composition.

3. The method for separating and recovering a layered film according to claim 1, wherein the layered film has a printing ink layer.

Description

EXAMPLES

[0066] Hereinafter, the contents and effect of the present invention will be described in more detail using examples. In addition, films, printing inks, reactive adhesives, and organic solvents that were used as raw materials in each of the examples and comparative examples will be described below.

(Films Used for Layered Films)

[0067] OPP: Biaxially stretched polypropylene film 20 um [0068] PET: Polyethylene terephthalate film 12 um [0069] OPA: Polyamide (nylon) film 15 um [0070] CPP: Non-stretched polypropylene film 35 urn [0071] LLDPE: Non-stretched linear low-density polyethylene film 60 um [0072] VMCPP: Aluminum-deposited non-stretched polypropylene film 25 um [0073] AL: Aluminum foil 9 um

(Printing Ink)

Solvent-Type Back Printing Gravure Ink

[0074] Ink1: FINART R507 primary color indigo/R794S white manufactured by DIC Graphics Corporation

Solvent-Type Front Printing Gravure Ink

[0075] Ink2: GROSSA R507 primary color indigo/R794S white manufactured by DIC Graphics Corporation

Aqueous Back Printing Flexographic Ink

[0076] Ink3: MAKING ROSS R507 primary color indigo/R793 white manufactured by DIC Graphics Corporation

(Reactive Adhesives)

Solvent-Type Adhesives

[0077] Ad1: DICDRY LX-401A/SP-60 manufactured by DIC Graphics Corporation [0078] Ad2: DICDRY LX-500/KW-75 manufactured by DIC Graphics Corporation

Solvent-Free Adhesive

[0079] Ad3: DICDRY 2K-SF-400A/HA-400B manufactured by DIC Graphics Corporation

(Unreactive Aqueous Adhesive)

Aqueous Emulsion Adhesive

[0080] Ad4: Eportal CF701 manufactured by BASF

(Morpholine Solutions)

[0081] Morpholine “M solution”: (manufactured by Kanto Kagaku, Reagent first grade) [0082] Aqueous solution of sodium hydroxide “SH solution”: A 5% by mass aqueous solution was adjusted by dissolving sodium hydroxide (reagent first grade) manufactured by Wako Pure Chemical Industries, Ltd. in ion-exchanged water.

(Method for Producing Layered Films)

[0083] Layered films were produced by performing printing on target films by a printing method and then laminating the target films together by a laminating method. The layer constitutions of the films, the reactive adhesives, and the types of the printing inks were determined according to the combinations in Table 1.

Printing Method

[0084] Each of the gravure inks and the flexographic ink, which were the printing inks, was spread on a film “Film1” using a proofer.

<Laminating Method>

[0085] A reactive adhesive “Ad” was applied with a laminator to the surface of the film “Film1” on which the printing ink had been spread or the surface opposite to the printing ink-spread surface such that the amount of a coating film reached 3 g/m.sup.2 in terms of the solid content, and the film “Film 1” was laminated with a film “Film2”. An aging reaction was caused in the laminated layered film at 40° C. for 72 hours. In the case of a three-laver constitution, the steps were repeated to obtain layered films “LAM1” to “LAM6”. The blending rates of the reactive adhesives “Ad” used were as described below. [0086] Ad1: DICDRY LX4G1A/SP-60=1/1 [0087] Ad2: DICDRY LX-500/KW75=10/1 [0088] Ad3: DICDRY 2K-SF-400A/HA-400B=100/50 [0089] Ad4: Eportal CF701=100

TABLE-US-00001 TABLE 1 Configuration of layered Outer surface side ← .fwdarw.inner surface side film Ink Film1 Ink Ad Film2 Ad Film3 LAM1 PET Ink1 Ad1 LLDPE LAM2 PET Ink1 Ad2 VMCPP LAM3 OPA Ink1 Ad3 LLDPE LAM4 Ink2 OPP Ad4 CPP LAM5 OPP Ink3 Ad3 CPP LAM6 PET Ink1 Ad2 AL Ad2 CPP *In the table, “outer surface side” refers to a surface of the layered film opposite to a surface that comes into contact with a content when the layered film is used as a packaging body (a surface that is on the outermost side during the distribution of the product), and “inner surface side” refers to the surface that comes into contact with the content when the layered film is used as the packaging body.

EXAMPLES

(Method for Separating and Recovering Layered Film, Step 1)

[0090] The layered films “LAM1” to “LAM6” were cut into sizes of 10 mm*10 mm to obtain test pieces. A peeling test was performed on these test pieces through Step 1-1 to Step 1-8.

[0091] Step 1-1: A stirring treatment on the M solution at 30° C.

[0092] Step 1-2: A stirring treatment on the M solution at 90° C.

[0093] Step 1-3: A stirring treatment on a solution of the M solution/ion-exchanged water (1/1) at 70° C.

[0094] Step 1-4: A stirring treatment on a solution of the M solution/the SH solution (1/1) at 70° C.

[0095] Step 1-5: A treatment on a solution of the M solution/the SH solution (1/1) with ultrasonic waves at 60° C.

[0096] Step 1-6: The M solution was stirred at 50° C., then, the test piece was removed, and the SH solution was stirred at 50° C.

[0097] Step 1-7: A stirring treatment on the M solution at 50° C. and then a stirring treatment on the ion-exchanged water at 70° C.

[0098] Step 1-8: A stirring treatment on ethyl acetate at 50° C.

(Method for Separating and Recovering Layered Film, Step 2)

[0099] After the step 1, the films were separated from the liquid by a filtration method, removed, washed with water, and then dried at 50° C.

[0100] After that, the peeling states of the films were observed. For the multilayered film including the aluminum-deposited film, the remaining of an aluminum atom in the film was confirmed with fluorescent X-rays on the peeled surface.

[0101] Table 2 and Table 3 show the results after the separation and recovery method. In the examples, the morpholine solution having a morpholine concentration of 50% by mass or more that was used in Step 1-1 to Step 1-7 was capable of peeling ail of the layered films into single-layered films that constituted the respective layers of the layered films. In addition, no ink layer remained on the single-layered films.

[0102] Among Examples 9 to 13 in which the layered film having an aluminum-deposited layer was used. Examples 9 and 13 are examples in which the morpholine solution in Step 1-3 that was a mixed solution of morpholine and ion-exchanged water was used In these examples, it was possible to isolate the single-layered films that constituted the respective layers of the layered films, but the aluminum-deposited layers remained in the films. On the other hand. Examples 10 to 12 are examples of Step 1-4 and Step 1-5 in which a mixed solution of morpholine and sodium hydroxide was used or Step 1-6 in which the stirring treatment was performed with the morpholine solution and then the treatment was performed with the aqueous solution of sodium hydroxide, and, in all of these examples, it was possible to peel off up to the aluminum-deposited layers from the films.

[0103] On the other hand, in Comparative Example 1, it was not possible to peel off the adhesive.

TABLE-US-00002 TABLE 2 Example Example Example Example Example Example Example Example Multilayer 1 2 3 4 5 6 7 8 film LAM1 LAM1 LAM1 LAM2 LAM3 LAM4 LAM5 LAM6 Step 1-1 Peeled Step 1-2 Peeled Peeled Peeled Peeled Peeled Peeled Step 1-3 Peeled Step 1-4 Step 1-5 Step 1-5 Step 1-7 Step 1-8

TABLE-US-00003 TABLE 3 Com- parative Multi- Example Example Example Example Example Exam- layer 9 10 11 12 13 ple 1 film LAM2 LAM2 LAM2 LAM2 LAM2 LAM1 Step 1-1 Step 1-2 Step Peeled*1 1-3 Step Peeled*2 1-4 Step Peeled*2 1-5 Step Peeled*2 1-6 Step Peeled*1 1-7 Step Not 1-8 peeled *1 Aluminum-deposited layer remains *2 No aluminum-deposited layer