JP2002127334A - Easily peelable laminate and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain a necessary adhesion strength under a normal use condition for distribution and storage or the like, and possesses an interface easily peeled when it is opened. SOLUTION: An easily peelable laminate is composed of at least a substrate, an adhesive layer, a polar synthetic resin substrate layer and a low density polyethylene. A nonpolar synthetic resin layer is extruded on a layer of which thickness is 5-15 μm, and a laminating strength between a polar synthetic resin substrate layer and a nonpolar synthetic resin substrate layer is 50-500 g/15 mm width. The substrate is paper. The polar synthetic resin substrate layer is a polyethylene terephthalate resin layer. The nonpolar synthetic resin substrate layer is a polyethylene resin layer. The easily peelable laminate is made by laminating a nonpolar synthetic resin in a thickness of 5-10 μm on one face of a film (a polar synthetic resin substrate layer) at a resin temperature of 240 deg.C-330 deg.C using an extrusion laminating process, and by laminating a substrate on other face of the polar synthetic resin substrate layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminate having a surface exhibiting easy peelability in a laminate and a method for producing the same.

[0002]

2. Description of the Related Art It is important for a laminate mainly for packaging that the bonding strength between layers be as high as possible in order to satisfy the function of the packaging.

[0003]

The peeling due to cohesive failure of materials such as paper and plastic film is common,
The opening (opening portion) due to such cohesive failure significantly impairs the appearance of the opening, and in addition, the information printed there may be unreadable. Thus, there has been a demand for a laminate that is easily peeled without cohesive failure and that can read legible printed information of a peeled portion without being destroyed.
As a structure of a package in a certain kind of product, at the distribution stage, it is a gas barrier package, and at the start of use, while the content is covered, volatile components are radiated from the content to the outside of the system, That is, there is a demand for a packaging bag that can exhibit gas permeability. Products that require packaging that allows gas permeation at the time of use include fragrances, deodorants, insect-control-related development, and hygroscopic agents. An object of the present invention is to provide an easily peelable laminate in which necessary adhesive strength is maintained under normal use conditions such as distribution and storage, and an interface exhibiting easy peelability is provided at the time of opening, and a method for producing the same. It is.

[0004]

According to the present invention, a non-polar synthetic resin layer comprising at least a substrate, an adhesive layer, a polar synthetic resin substrate layer, and low density polyethylene is extruded to a thickness of 5 to 15 μm. And a laminate strength of the polar synthetic resin base material layer and the non-polar synthetic resin layer of 50 to 500 g /
An easily peelable laminate characterized by having a width of 15 mm, wherein the base material is paper, and the polar synthetic resin base material layer is a polyethylene terephthalate resin layer,
The non-polar synthetic resin layer includes a polyethylene resin layer, and a method for producing the non-polar synthetic resin layer includes a non-polar synthetic resin layer on one side of a film that is a polar synthetic resin base layer.
Extrusion lamination at a resin temperature of
It is laminated to a thickness of 10 μm, and a substrate is attached to the other surface of the polar synthetic resin substrate layer.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a laminate used for a printing concealing sheet, various kinds of packaging, etc., wherein an easily peelable interface is formed on the laminate. FIG. 1 is a cross-sectional view showing an embodiment of the easily peelable laminate of the present invention, in which (a) an example in which wet lamination is used for adhesion between an easily peelable laminate and a substrate, and (b) a sandwich lamination method. This is the case when used. FIG. 2 is a cross-sectional view showing a print concealing sheet (Application Example 1) using the easily peelable laminate of the present invention, and shows (a) before peeling and (b) after peeling. FIG. 3 is a cross-sectional view showing another print concealing sheet (application example 2) using the easily peelable laminate of the present invention, and shows (a) before peeling and (b) after peeling. FIG.
1 is a cross-sectional view showing a package (Application Example 3) using the easily peelable laminate of the present invention, and (a) a perspective view of the package,
(B) (c) are both prior separation of X ₁ -X ₁ part a cross-sectional view after peeling and, (d) is Y1, (e) is Y2, (f) is Y
3, (g) is Y4, (h) is Y5, (i) is Y6,
(J) is an enlarged view of each of Y7. FIG. 5 is a cross-sectional view showing another package (Application Example 4) using the easily peelable laminate of the present invention, where (a) is a perspective view of the package, and (b) is a perspective view of the package.
(C) is a cross-sectional view after peeling both prior separation of X ₂ -X ₂ parts, and, (d) is Y8, (e) is Y9, (f) is Y10,
(G) is Y11, (h) is Y12, (i) is Y13,
(J) is an enlarged view of each of Y14. FIG. 6 shows an example in which, in a package using the easily peelable laminate of the present invention, the content is covered with a non-polar synthetic resin layer after peeling and peeled, and (a) before peeling and (b) after peeling. It is sectional drawing which shows the state of. FIG. 7 shows an example of a knob when peeling and exposing the contents in a package using the easily peelable laminate of the present invention, wherein (a) a state before peeling and (b) a state after peeling. FIG.

As shown in FIGS. 1 (a) and 1 (b), the easily peelable laminate of the present invention comprises a polar synthetic resin base material layer 3 and a non-polar synthetic resin layer. 4 and characterized in that it includes an easily peelable laminate 10 formed from the above. The present inventors have conducted intensive studies on stably providing easy peelability at the interface in the layer structure of the laminate, which is the subject of the present invention, and found that the polar synthetic resin base material layer 3 was extruded on one side by an extrusion method. Adhesive strength of the bonded surface of the polar synthetic resin base material layer 3 and the non-polar synthetic resin layer 4 in a configuration comprising the formed non-polar synthetic resin layer 4 (hereinafter referred to as an easily peelable laminate). In the range of 50 to 500 g / 15 mm width, and a laminate (easily peelable laminate) in which the base layer 2 is bonded to the other surface of the polar synthetic resin base layer 3 of the easily peelable laminate 10. As a result, they have found that the above-mentioned problems can be solved, and have completed the present invention.

In the present invention, the polar synthetic resin substrate layer 3 is a biaxially stretched polyester film, a biaxially stretched polyamide film, a polycarbonate film, a polyacrylonitrile film. Further, as the non-polar synthetic resin layer, various kinds of polyethylene, polypropylene, polymethylpentene and the like are used.

Further, as a method of obtaining an adhesive strength showing easy peelability of the present invention, as a result of various experiments, the resin forming the non-polar synthetic resin layer 4 was extruded on the polar synthetic resin base layer 3. The resin temperature during extrusion is 2
It was found that setting the temperature to 40 to 350 ° C. was effective. When the extrusion temperature is less than 240 ° C., the laminate strength required for distribution and storage cannot be obtained, and when the extrusion temperature is set to a temperature exceeding 350 ° C., the laminate strength increases, The intended effect of easy peelability cannot be expected. For example, when the polar synthetic resin base material layer 2 is formed into a biaxially stretched polyester film, and the nonpolar synthetic resin layer 4 is formed as low-density polyethylene by extrusion coating on the biaxially stretched polyester film to form an easily peelable laminate. The extrusion temperature is 280 to 30
0 ° C. is appropriate.

The thickness of the non-polar synthetic resin layer 4 in the easily peelable laminate 3 of the present invention is 5 to 15 in view of the stability of easy peelability and the ease of opening when used for packaging.
It is preferably in the range of μm.

When the easily peelable laminate 1 of the present invention is used as a packaging material, the package using the same maintains the necessary adhesive strength until it is opened, and the non-polar synthetic resin layer 4 Leaving only (the state of covering the contents), the base material layer 2
(Hereinafter, referred to as semi-opening) in which the resin and the polar synthetic resin base material layer 3 are separated from each other. In this half-opening, the physical properties (gas permeability, moisture-proof property, etc.) of the nonpolar synthetic resin layer 4 affect the contents from the moment of opening. In addition, it is also possible to open the contents, which is a normal opening, to expose the contents.

In the half-opening, a non-seal portion is provided in a part of the package, and as shown in FIG. 6 (a), a force is applied in a direction in which any one side of the non-seal portion NC is pinched and peeled off. Since the non-polar synthetic resin layer 4 is easily broken and the adhesive interface between the polar synthetic resin base material layer 3 and the non-polar synthetic resin layer 4 is peeled off, as shown in FIG. State. In addition, when using the easily peelable laminate 1 of the present invention to open normally, that is, when opening the contents C to be exposed,
As shown in FIG. 7A, a half cut HC having a depth for cutting the nonpolar synthetic resin layer 4 may be provided inside the peripheral seal portion. In this case, when a force is applied in a direction in which the opening knob is pinched and peeled, the nonpolar synthetic resin layer 4 is easily broken, and the polar synthetic resin 3 and the nonpolar synthetic resin layer 4 are easily peeled. However, from the position of the half cut HC,
Since there is no force separating the polar synthetic resin 3 and the non-polar synthetic resin layer 4, the non-polar synthetic resin layer 4 is in a state of being bonded to the polar synthetic resin base material layer 3, and as shown in FIG. As shown in the figure, when the lid 10 is finally peeled off, the contents C are in a normal unsealed state where the contents C are exposed.

First, the base material layer in the easily peelable laminate of the present invention is preferably a material having the strength and dimensional stability necessary for a base material in laminating and having printability. Specific materials forming the material include paper, synthetic paper, polypropylene, polyester, polyamide, polycarbonate, and the like, and a single paper, film, or a combination of two or more of these materials. It may be paper or a composite film. In the case of a composite film, in addition to the above-described materials, aluminum, iron, copper, tin, a metal film such as tin, a barrier-coated film such as polyvinylidene chloride or aluminum, aluminum oxide, silica, etc. A vapor-deposited film may be used.

[0013] The easily peelable laminate of the present invention can be obtained by laminating the above easily peelable laminate and a substrate, and the laminate of the easily peelable laminate and the substrate layer functions as a package. The method is not limited as long as the method has a strength that does not impair the quality and does not affect the quality of the contents. For example, when the base material layer is paper, the easily peelable laminate is formed, and the other surface of the non-polar synthetic resin layer-laminated polar synthetic resin base material layer is subjected to a surface treatment such as a corona discharge treatment. A so-called wet lamination may be used in which an acrylic resin-based adhesive or the like is applied to the treated surface, and the paper as the base material layer is attached and dried in a drying hood. Alternatively, the base material layer and the easily peelable laminate may be laminated by a sandwich lamination method by extruding a polyethylene adhesive resin or the like using an extrusion laminating machine.

The easily peelable laminate of the present invention uses an opaque material such as paper as its base material layer, and has a non-polar synthetic resin layer on the printing surface of the paper on which information to be hidden (hidden printing 1) is printed. Can be made into a print concealing sheet by heat sealing. Information to be hidden on the laminate surface of the base layer of the easily peelable laminate (hidden printing 2)
In addition, a sheet having a structure in which the hidden print appears on both of the peeled surfaces when the hidden print 1 is peeled off by heat sealing the printed paper.

The easily peelable laminate of the present invention can be used as a packaging material for a pouch, a lid of a blister pack, or the like. In a state in which a thin film of polyethylene, for example, is left, it is possible to perform opening (hereinafter, referred to as semi-opening) in which only the base material layer is peeled and separated instead of completely opening. If the base material layer is a layer having a barrier property, the package will be a package having high gas permeability by the half opening.
The semi-opening function that allows gas permeation from the moment of opening can be used for packaging desiccants, desiccants, oxygen absorbers, fragrances, and the like.

[0016]

EXAMPLES The easily peelable laminate of the present invention will be described in more detail with reference to examples. [Embodiment 1] As shown in FIG.
The printing layer 5 is provided on 400 g / m2 of paper, and the upper sheet 2
As 1, the easily peelable laminate of the present invention is used. The configuration of the easily peelable laminate is as follows: 400 g / cm 2 of paper as a base material, and a biaxially stretched polyester film 1 as a polar synthetic resin base material layer 3.
2 μm (E5100 manufactured by Toyobo Co., Ltd.), and the non-polar synthetic resin layer 4 was 10 μm low-density polyethylene (MIIP manufactured by Mitsui Chemicals, Inc.). The non-polar synthetic resin layer was formed by extrusion lamination at a resin temperature of 290 ° C. on a polar synthetic resin base layer. The printed surface of the lower sheet and the non-polar synthetic resin layer surface of the upper sheet are superimposed on each other, and by heating under pressure, the printed surface of the lower sheet and the low-density polyethylene surface of the upper sheet are heat-sealed,
Printing concealment sheet 1 was obtained. Since the print concealing sheet 1 is in a state where the print layer 5 is sandwiched by the paper layer 22 and the easily peelable laminate including the paper layer, the print concealment sheet 1 cannot be visually recognized from the outside. When the non-seal portion provided at the end of the printing concealing sheet 1 was pinched and peeled, the peeling surface 9 was easily peeled off, and the printing layer 5 was formed of a non-polar synthetic resin layer as shown in FIG. 4 was clearly visible in a state covered with the low-density polyethylene.

[Embodiment 2] As shown in FIG. 3 (a), both the upper sheet and the lower sheet use the easily peelable laminate having the same structure according to the present invention. As the layer, 400 g / m2 of paper was used, and a printing layer 5 was provided on one side of each base layer. As an easily peelable laminate, 2
A linear low-density polyethylene (Ultzex 15100C manufactured by Mitsui Chemicals, Inc.) was formed into an 8 μm thick extrusion film at a resin temperature of 300 ° C. on one side of an axially stretched polyester film 12 μm. The polyester surface opposite to the surface on which the non-polar synthetic resin layer 4 of the easily peelable laminate 10 is laminated is subjected to corona treatment, and an adhesive containing an acrylic resin as a main laminate component is applied to the corona treated surface to form a base layer. , And dried in a drying hood to obtain an easily peelable laminate. After the non-polar synthetic resin layer surfaces 4 of the obtained easily peelable laminate 20 were polymerized with the surfaces 4 facing each other, this was heated under pressure (heat sealing) to obtain a print concealing sheet 2. When the obtained non-seal portion provided at the end of the print concealing sheet 2 was pinched and peeled, the peeled surface 9 was easily peeled off, and the printed layer was peeled off as shown in FIG. The print provided on the hitting surface was clearly visible

Example 3 Printing was performed on a table of 400 g / m 2 of paper, and a 9 μm aluminum foil was wet-laminated to form a base layer. Separately, a low-density polyethylene was extruded on one side of a biaxially oriented polyester film 16 μm by extrusion.
A film was formed to a thickness of 2 μm to obtain an easily peelable laminate. The resin temperature during the extrusion was 290 ° C. After corona-treating the other surface of the easily peelable laminate, an isocyanate-based anchor coat agent is applied to the corona-treated surface, and ethylene methacrylic resin (EMAA, N1109C manufactured by DuPont-Mitsui Polychemicals Co., Ltd.) is bonded to the adhesive resin. And extruded to a thickness of 15 μm and sandwich-laminated to obtain an easily peelable laminate. Using the obtained easily peelable laminate as a material, a pouch as shown in FIGS. 4 (a) and 4 (b) is made, and a fragrance sheet (jelly-like) is sealed and sealed as the content C. A package 1 was obtained. After storing the obtained package 1 in a constant-temperature oven (25 ° C.) for one month, one side was peeled off, and the easily peelable laminate was placed in a semi-open state with a thin film of low-density polyethylene covered with a thin film, and it took 1 minute. Later, the fragrance of the fragrance was felt, and thereafter the fragrance was continued.

Example 4 A 350 μm polypropylene sheet and a 40 μm medium-density polyethylene film were dry-laminated as a tray material of a blister, and a rectangular recess (40 mm × 80 mm, depth 1) was formed by vacuum molding.
5 mm). The lid was used as the easily peelable laminate of the present invention, and its structure was printed on the silica-deposited surface of a 15 μm silica-deposited biaxially stretched polyamide film as a substrate layer. The easily peelable laminate was formed by forming a low-density polyethylene film on one side of a biaxially stretched polyester film 12 μm to a thickness of 15 μm by extrusion. The resin temperature during the extrusion was 300 ° C. Next, the printed surface of the base layer and the polyester resin surface of the easily peelable laminate were dry-laminated and used for a lid. 70 g of a desiccant was stored in the recess of the tray, and FIG.
As shown in (a) and FIG. 5 (b), the flange was heat-sealed and sealed with the lid to obtain a package 2.
When the obtained package 2 was peeled off from a predetermined knob portion, as shown in FIG. 5 (c), it could be very easily peeled off from the adhesive interface between the biaxially stretched polyester film 3 and the low-density polyethylene layer 4. As a result, only the low-density polyethylene layer 4 having a thickness of 15 μm of the lid was left in a semi-open state where it remained on the tray side. When five of the half-opened packages were left in the dressing cabinet for four months (March to September), the moisture absorption of the desiccant was about 500 g in total for all five packages.

[0020]

The easily peelable laminate of the present invention has an appropriate peel strength as a printing concealing sheet and print information appearing on the peeled surface can be clearly recognized. Further, for packaging applications, since the thin film layer of the nonpolar synthetic resin layer is peeled off while being covered, it can be developed as a packaging container for an aromatic material, a desiccant, a moisture absorbent, an oxygen scavenger and the like. Also, in the case of packaging use, as in the case of the printing concealing sheet, the present invention has an effect that printed information after peeling remains in a clear state.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of an easily peelable laminate of the present invention, in which (a) an example in which wet lamination is used for adhesion between an easily peelable laminate and a substrate, and (b) a sandwich lamination method. This is the case when used.

FIG. 2 is a cross-sectional view showing a printing concealing sheet (Application Example 1) using the easily peelable laminate of the present invention, wherein (a) before peeling,
(B) Shows after peeling.

FIG. 3 is a cross-sectional view showing another print concealing sheet (Application Example 2) using the easily peelable laminate of the present invention, in which (a) before peeling and (b) after peeling.

FIG. 4 is a cross-sectional view showing a package (Application Example 3) using the easily peelable laminate of the present invention, and (a) a perspective view of the package;
(B) (c) are both prior separation of X ₁ -X ₁ part a cross-sectional view after peeling and, (d) is Y1, (e) is Y2, (f) is Y
3, (g) is Y4, (h) is Y5, (i) is Y6,
(J) is an enlarged view of each of Y7.

FIG. 5 is a cross-sectional view showing another package (Application Example 4) using the easily peelable laminate of the present invention, wherein (a) is a perspective view of the package, and (b) and (c) are X _2. before separation of -X ₂ parts, and a cross-sectional view after peeling, (d) is Y8, (e) is Y9, (f)
Is an enlarged view of Y10, (g) is an enlarged view of Y11, (h) is an enlarged view of Y12, (i) is an enlarged view of Y13, and (j) is an enlarged view of Y14.

FIG. 6 shows an example in which, in a package using the easily peelable laminate of the present invention, the content is covered with a non-polar synthetic resin layer after peeling and peeled, and (a) before peeling and (b) after peeling. It is sectional drawing which shows the state of.

FIG. 7 shows an example of a knob when peeling and exposing the contents in a package using the easily peelable laminate of the present invention, wherein (a) a state before peeling and (b) a state after peeling. FIG.

[Explanation of symbols]

 C Contents HS Heat sealing part NS Non-sealing part T Opening knob H Release sheet HC Half cut 1 Easy release laminate 2 Base layer 3 Polar synthetic resin base layer 4 Nonpolar synthetic resin layer 5 Print layer 6 Surface treatment 7ac Anchor coat layer 7 Adhesive layer 8 Adhesive resin layer 9 Release surface 10 Easy release laminate 20 Printing concealment sheet 21 Upper sheet 22 Lower sheet 30 Packaging (pouch) 31 Upper film 32 Lower film 40 Packaging ( Blister) 41 Lid 42 Tray 43 Molded base sheet

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 4F100 AK01B AK04C AK06C AK42B AT00A BA03 BA07 BA10A BA10C CB00 DG10A EC182 EH171 GB15 HB31 JD02 JK06 JL14 YY00 YY00B YY00C 4F207 AA04 AD05 AD06 AR06 KB13 KA03

Claims (5)

[Claims] 1. A layer comprising at least a base material, an adhesive layer, a polar synthetic resin base material layer, and a low-density polyethylene, wherein a non-polar synthetic resin layer is formed by extrusion to a thickness of 5 to 15 μm,
An easily peelable laminate, wherein the laminate strength of the polar synthetic resin base layer and the non-polar synthetic resin layer is 50 to 500 g / 15 mm width. 2. The easily peelable laminate according to claim 1, wherein said base material is paper. 3. The polar synthetic resin base material layer is a polyethylene terephthalate resin layer.
Or the laminate according to claim 2. 4. The laminate according to claim 1, wherein said non-polar synthetic resin layer is a polyethylene resin layer. 5. A non-polar synthetic resin is laminated on one side of a film which is a polar synthetic resin base material layer to a thickness of 5 to 10 μm by extrusion lamination at a resin temperature of 240 ° C. to 330 ° C.
A method for producing an easily peelable laminate, wherein a substrate is attached to another surface of the polar synthetic resin substrate layer.