JP4813236B2 - Laminated body - Google Patents

Description

  The present invention relates to a laminate having a resin capable of adjusting the strength of a peeled surface depending on the application.

  As an easy peeling (easy peel) mechanism in a conventional laminate, for example, there is easy peeling between an olefin resin and a cardboard. In such easy peeling using paper, it is not necessary to apply a surface treatment agent (peeling agent) for peeling, but the paper surface is exposed on the peeling surface, so it can be used for safety and hygiene issues. In addition to the limited paper material, there were problems such as paper peeling on the exposed surface.

  As an easy peeling mechanism that does not use paper, there is interfacial peeling between a polyester film (for example, polyethylene terephthalate (PET) film) and an extruded laminated resin. However, conventionally, there is no laminate having an appropriate peel strength at the interface between the polyester film and the extrusion-laminated resin, and when the peel strength at the interface (hereinafter referred to as interface peel strength) is to be adjusted, for example, a patent As disclosed in Document 1, it is necessary to use a surface treating agent. Therefore, conventionally, in the production of a laminate, an easy-peeling region was formed by applying a surface treatment agent to the peeled surface to realize easy peeling.

  However, when a surface treatment agent is used in the production of a laminate, there are problems that the number of production steps increases due to the application of the surface treatment agent, and that adjustment of the interfacial peel strength is difficult. In addition, there is a possibility that the surface treatment agent may be mixed in the inside of the container and the like, so that there is a possibility that it cannot be applied to food or pharmaceutical packaging due to safety and hygiene problems.

From the above, it is desired to realize a laminate that can be produced without using a surface treating agent and can adjust the interfacial peel strength in interfacial peeling of a polyester film.
JP 2004-126546 A

  The present invention has been made in view of the above circumstances, and provides a laminate capable of adjusting the interfacial peel strength according to the application without using a surface treating agent in interfacial peeling of a polyester film. For the purpose.

In order to achieve this object, the laminate of the present invention is a laminate having a surface layer having a base material and an adhesive film, and a polyester film layer, the adhesive film of the surface layer and the polyester film. Between the layers, there is an easily peelable resin layer in which a polyolefin and a cyclic olefin copolymer are mixed, the adhesive film is formed of polyolefin, and the content of the cyclic olefin copolymer mixed in the easily peelable resin layer is 1 to It is 24 weight%, The interface of a polyester-type film layer and an easily peelable resin layer becomes a peeling surface, It is characterized by the above-mentioned.

In the laminate of the present invention , the polyester film layer has a surface wetting tension of 35 dyne / cm to 60 dyne / cm.

In the laminate of the present invention , the polyester film layer is formed of polyethylene terephthalate.

  According to the present invention, in a laminate that realizes interfacial peeling of a polyester film, by having an easy-peeling resin layer made of an easy-peeling resin in which a polyolefin and a cyclic olefin copolymer are mixed, a surface treatment agent is not used. In addition, it is possible to adjust the interfacial peel strength according to the application.

The best mode for carrying out the present invention will be described below in detail with reference to the accompanying drawings.
The basic structure of the laminate of the present invention is shown in FIG. As shown in FIG. 1, the laminate of the present invention has a configuration in which a surface layer 8, an easily peelable resin layer 3, and a polyester film layer 4 are sequentially laminated. A separation surface 5 is formed between the film layer 4 and the separation surface 5 and interfacial separation occurs. In addition, when the laminated body shown in FIG. 1 is used for a packaging material, either the easily peelable resin layer 3 or the polyester film layer 4 may be on the inner layer side.

  FIG. 2 is a side cross-sectional view schematically showing the configuration of a laminate that is an example of the present invention. As shown in FIG. 2, the laminate of this example has a surface layer 8 and a base material layer 9, and has an easily peelable resin layer 3 between the two layers.

  As shown in FIG. 2, the surface layer 8 has the base material 1 used as an outermost layer, and the adhesive film 2 provided in the single side | surface of the base material 1, and the base material layer 9 is a polyester-type film. It has the layer 4, the intermediate | middle layer 6, and the sealant layer 7 used as an innermost layer. Therefore, as shown in FIG. 2, the laminate of this example has a configuration in which a base material 1, an adhesive film 2, an easily peelable resin layer 3, a polyester film layer 4, an intermediate layer 6, and a sealant layer 7 are sequentially laminated. It has become. Further, in the laminate of this example, the interface between the easily peelable resin layer 3 and the polyester film layer 4 is a peeled surface 5, and easy peeling is realized on the peeled surface 5.

  As the substrate (substrate film) 1, for example, polypropylene resin, polyamide resin, polyester resin, saponified ethylene-vinyl acetate copolymer, polyvinylidene chloride, polycarbonate and other plastic films or sheets, aluminum, iron , Copper, metal foil such as an alloy containing these as a main component or metal plate, cellophane, paper, woven fabric, non-woven fabric, etc. can be used, and these may be laminated as a single layer, or one or more. Good. In consideration of dimensional stability, heat resistance, mechanical strength, printing suitability, etc., it is preferable to use polyethylene terephthalate (PET), biaxially oriented polypropylene (OPP), or nylon (Ny). This base material 1 forms a surface layer 8 together with the adhesive film 2 as shown in FIG. 2 by an adhesion method such as wet lamination, non-solvent lamination, dry lamination, extrusion lamination or the like.

  The adhesive film 2 is made of polyethylene (PE), polypropylene (PP), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), unstretched polypropylene (CPP), EMAA (ethylene-methacrylic acid copolymer resin). This is a film that is made of a polyolefin film such as the above and is formed on one side of the substrate 1 as shown in FIG.

  In this example, the adhesive film 2 was used. However, instead of the adhesive film 2, polypropylene (PP), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), EMAA (ethylene-methacrylic acid) The thermal adhesive layer may be formed of an extruded resin such as a copolymer resin. Further, an anchor coat agent (AC agent) may be further used for the adhesive film 2, or a thermal adhesive layer may be formed only with the AC agent.

  In addition, as a material for the adhesive film 2, the same material as the resin for forming the easily peelable resin layer 3 (hereinafter referred to as an easily peelable resin) is used in order to secure the adhesive strength with the easily peelable resin layer 3. It is good. Specifically, when a cyclic olefin copolymer and a polyethylene resin are mixed as an easily peelable resin, a polyethylene resin is used as an adhesive film. Moreover, when mixing a cyclic olefin copolymer and polypropylene resin as easy-release resin, polypropylene resin is used as an adhesive film. Thus, by using the same resin as the easily peelable resin, the adhesive film 2 and the easily peelable resin layer 3 can be laminated with sufficient adhesive strength.

  Further, as the role of the adhesive film 2, in addition to the role of obtaining sufficient adhesive strength between the adhesive film 2 and the easily peelable resin layer 3 as described above, the longitudinal olefin copolymer mixed in the easily peelable resin has It has a role of preventing vertical tearing when it is peeled off from the base material layer 9 by killing the tearability.

  The easily peelable resin layer 3 is easily formed between the surface layer 8 and the PET film layer 4 when the surface layer 8 composed of the base material 1, the adhesive film 2 and the polyester film layer 4 are extruded and laminated. It is a layer formed by extrusion laminating a release resin. The thickness of the easily peelable resin layer 3 is preferably 10 μm to 40 μm in order to obtain a stable peel property. In this embodiment, the interfacial peel strength can be adjusted by changing the extrusion conditions (thickness, temperature, etc.) of the easily peelable resin.

  This easily peelable resin is a resin in which a cyclic olefin copolymer (COC) is mixed with polyolefin at a predetermined ratio. Arbitrary materials can be used for the polyolefin and the cyclic olefin copolymer (COC) constituting the easily peelable resin. Further, the blending ratio of polyolefin and cyclic olefin copolymer (COC) can be arbitrarily selected and changed.

Examples of the polyolefin constituting the easily peelable resin include polyethylene (PE) resin, polypropylene (PP) resin, etc., but it is preferable to use low density polyethylene (LDPE) in terms of extrusion (neck-in). . The MFR (Melt Flow Rate) of the polyolefin is preferably 1 to 50 [g / min], more preferably 1 to 10 [g / min]. The density of the polyolefin is preferably 0.89 to 0.940 [g / cm ³ ].

  The cyclic olefin copolymer (COC) constituting the easy-release resin is a so-called Ziegler catalyst or metallocene catalyst in which α-olefin and cyclic olefin are mixed with hydrocarbon solvents such as hexane, heptane, octane, cyclohexane, benzene, toluene, and xylene. It is a copolymer that can be obtained by blending a catalyst such as As an example of such a copolymer, there is a trade name “Apel” manufactured by Mitsui Chemicals. The MFR of the cyclic olefin copolymer (COC) is preferably 1 to 40 [g / min], more preferably 5 to 25 [g / min].

  In the present embodiment, the surface treatment agent is obtained by using the easily peelable resin layer 3 formed by the easily peelable resin in which polyolefin and cyclic olefin copolymer (COC) are mixed at a predetermined ratio for interfacial peeling of the PET film layer 4. The interfacial peel strength can be adjusted without using.

  In the release resin of this example, the content of the cyclic olefin copolymer (COC) is preferably 1 to 24% by weight, and particularly preferably 5 to 20% by weight. This is because when the content is less than 1%, the interfacial peel strength becomes strong, and when it is more than 24%, the peel strength cannot be controlled.

  Moreover, in this example, since the easily peelable resin layer 3 is sand-laminated between the surface layer 8 and the base material layer 9, a laminate can be produced with a small number of steps.

  In this example, the type and blending ratio of the polyolefin and the cyclic olefin copolymer (COC) constituting the easy-release resin are arbitrarily selected and changed, and the extrusion conditions (thickness, temperature, etc.) of the easy-release resin are changed. By arbitrarily selecting and changing, the interfacial peel strength can be adjusted according to the application.

  As the polyester film layer 4, a polyester film can be used. In this embodiment, a polyethylene terephthalate (PET) film is taken as an example. The polyester film layer 4 preferably has a surface wetting tension of 35 dyne / cm to 60 dyne / cm. More preferably, the surface wetting tension is 40 to 50 dyne / cm. The reason is that if it is 35 dyne / cm or less, the adhesive strength is lowered, and if it is 60 dyne / cm or more, the adhesive force is improved, so that it is difficult to adjust the strength of the easily peelable resin. The interfacial peel strength can also be adjusted depending on the degree of surface treatment (for example, corona treatment) of the polyester film layer 4.

  The intermediate layer 6 is a layer formed using polyethylene terephthalate (PET), polyethylene (PE), paper, or the like as a material. However, the material is not limited to these, and the materials mentioned in the description of the substrate 1 may be used. .

  The sealant layer 7 is a layer formed using an appropriate material according to the material and required function of a cup container or the like to which the laminate of this embodiment is applied. Examples of materials include PE and PP, but are not limited thereto, and materials generally used as a sealant may be used.

As described above, the structure shown in FIG. 2 has been described as an example for the laminated body of this example, but other structure examples are shown in the following (1) to (7). In (1) to (7), the left end is the outermost layer, and the layers are sequentially laminated, and the easy release resin layer 3 is described as an easy release resin. In addition, “//” indicates that bonding is performed using an adhesive, and “/” indicates that bonding is performed without using an adhesive.
(1) PET // LDPE / easy release resin / PET / paper / PE / aluminum / sealant (2) PET / AC agent / easy release resin / PET / paper / PE / aluminum / sealant (3) paper // PET / / LDPE / Easily Release Resin / PET // Aluminum / Sealant (4) Paper / PE / Easily Release Resin // PET // Sealant (5) PET // LDPE / Easily Release Resin / PET / Sealant (6) Paper // PET / Easily peelable resin / PE / Aluminum / Sealant (7) PET // ONy (stretched nylon) // PET / Easily peelable resin / PE / sealant

  Next, the interfacial peel strength of the easily peelable resin layer 3 in the laminate of this example will be described below with reference to the experimental results of FIG.

<Experiment>
The easy release resin used in this experiment is a mixture of LDPE “Suntech L1850K” (manufactured by Asahi Kasei Chemicals) as polyolefin and “APL6013T” (manufactured by Mitsui Chemicals) as COC. As for the mixing ratio, “APL6013T” (hereinafter referred to as APL) is blended by 5% with respect to “Suntech L1850K” (hereinafter referred to as L1850K). In this experiment, PET “Toyobo Ester E5100” (manufactured by Toyobo Co., Ltd.) is used as the base material and LDPE “Suzuron S-201” (manufactured by Aicero Chemical Co., Ltd.) is used as the adhesive film 2 in each mixing ratio. Then, the film was peeled from the polyester film layer 4 having a surface wetting tension of 40 dyne / cm or more at the peeling surface 5, and the interfacial peel strength of the easily peelable resin layer 3 (easy to peel off the adhesive film 2) was examined. The interfacial peel strength when L1850K is 100% and APL is 0% is 8.0 N (Newton), which is the reference value.

  As shown in FIG. 3, in the easily peelable resin layer 3, when L1850K is 95% and APL is 5%, the interface peel strength is 2.0N, L1850K is 90% and APL is 10%. The interfacial peel strength when 1.6N, L1850K was 85%, and APL was 15% was 1.3N, and the interfacial peel strength when L1850K was 80% and APL was 20% was 1.0N. Thus, when the ratio of APL (COC) to be mixed was 0% to 20%, the interfacial peel strength was reduced as compared with the reference value.

  On the other hand, as shown in FIG. 3, in the easily peelable resin layer 3, when L1850K is 75% and APL is 25%, the peel strength is 4.0N, L1850K is 70%, and APL is 30%. The peel strength in the case of 4.1N, L1850K of 65%, and APL of 35% was 4.0N. In this way, when the ratio of APL (COC) to be mixed is 25% or more, stringing due to longitudinal tearing of the easily peelable resin occurs and interfacial peeling is not recognized, so that the peel strength increases. When the ratio of (COC) was 25% to 35% by weight, a constant peel strength was obtained.

  In the above experiment, even when EMAA was used instead of COC, a result close to that using COC was obtained.

  As shown by the above experimental results, conventionally, in the interfacial peeling between the polyester film layer located in the intermediate layer of the laminate and the easily peelable resin layer, the interfacial peel strength is adjusted without using a surface treatment agent (control) However, according to the easily peelable resin layer 3 of this example, the surface treatment agent was not used by changing the mixing ratio of the low density polyethylene (LDPE) and the cyclic olefin copolymer (COC). In addition, it is possible to adjust (control) the interfacial peel strength of the polyester film layer according to the application.

  As mentioned above, although the Example of this invention was described, it is not limited to description of the said Example, A various deformation | transformation is possible in the range which does not deviate from the summary.

  The present invention can be applied to lids and easy-open packaging materials such as foods, beverages, seasonings, cosmetics, and pharmaceuticals.

It is a sectional side view which shows typically the basic composition of the laminated body of this invention. It is a sectional side view which shows typically the structure of the laminated body which is an Example of this invention. It is a table | surface which shows the compounding ratio of the easily peelable resin which concerns on the Example of this invention, and interfacial peel strength.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material 2 Adhesive film 3 Easily peelable resin layer 4 Polyester-type film layer 5 Release surface 6 Intermediate layer 7 Sealant layer 8 Surface layer 9 Base material layer

Claims (3)

A surface layer having a substrate and an adhesive film ;
A polyester-based film layer,
Between the adhesive film of the surface layer and the polyester film layer, an easily peelable resin layer in which a polyolefin and a cyclic olefin copolymer are mixed,
The adhesive film is formed of polyolefin;
The content of the cyclic olefin copolymer mixed in the easily peelable resin layer is 1 to 24% by weight,
A laminate comprising an interface between the polyester film layer and the easy-release resin layer as a release surface. Laminate according to claim 1, wherein the surface wetting tension of the polyester film layer is equal to or less than 35 dyne / cm or more ~60dyne / cm. The said polyester-type film layer is formed with a polyethylene terephthalate, The laminated body of any one of Claim 1 or 2 characterized by the above-mentioned.

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