JP2016020075A - Laminate material, and container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive container with great clarity of information written thereon.SOLUTION: A container comprises a laminate material comprising an olefinic film, a print layer, a gas barrier film, and a substrate layer, which are laminated in this order.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a laminated material and a container.

  In recent years, in order to cope with the cost reduction by raising the consumption tax to 8%, supermarkets and convenience stores are urgently required to reduce the amount of side dishes and bento boxes that are generated due to expiration of consumption. Therefore, in order to make it possible to reduce the amount of waste by extending the expiration date, a one-way plastic container for sugar beet and lunch box with gas barrier properties is required. As an example of use, a one-way plastic container having a gas barrier property is sealed with a top seal with a gas barrier property, and gas (nitrogen gas, oxygen gas, carbon dioxide gas, or a mixed gas of any two or more) is substituted. There is a way. FIG. 1 shows a cross-sectional view of a one-way plastic container when a top seal is applied with a lid having a gas barrier property. Thereby, it becomes possible to maintain the freshness of the food which is easy to corrode and to extend the expiration date.

  Patent Document 1 is known as a one-way plastic container having gas barrier properties. (Patent Document 1)

  As represented by Patent Document 1, it has been a common social wisdom that a one-way plastic container having a gas barrier property is expensive only by itself, and design properties such as printing are not necessary.

  In the future, in order to popularize one-way plastic containers having gas barrier properties as containers for prepared foods and lunch boxes, it is essential to have a good design such as clean printing in order to emphasize the contents and the high-quality appearance.

  Patent Document 2 shows an example of a gas barrier multilayer film (for example, a film having low permeability to oxygen gas, water vapor gas, carbon dioxide gas). As the gas barrier multilayer film, a coextruded multilayer film having a gas barrier resin layer is used. This is because the extrusion method called co-extrusion is a production method in which the gas barrier resin layer, which is expensive, can be made thin, and has an advantage that it can be produced at low cost. In general, a coextruded multilayer film having a gas barrier resin layer is known to have a three-kind five-layer structure sandwiched with an olefin resin layer in order to protect the barrier layer. What laminated | stacked it on the base material sheet | seat is an example of the barriering laminated material shown in FIG.

  As shown in FIG. 3, in the barrier laminate, the food is placed on the surface on the innermost layer side (the side opposite to the base sheet: the uppermost layer side). Therefore, the innermost layer is usually composed of an olefin resin layer 11 such as polyethylene or polypropylene. A gas barrier layer 13 is laminated on the lower side (base material side) of the olefin resin layer (innermost layer) 11 via an adhesive layer 12. On the lower side (base material side) of the gas barrier layer 13, an olefin resin layer 15 is laminated via an adhesive layer 14. Further, when printing is necessary, the printing layer 16 is laminated on the lower side (base material side) of the olefin-based resin layer 15. A substrate 6 that is the outermost layer (lowermost layer) is laminated on the lower side of the printing layer 16 via an adhesive layer 17.

  When printing is necessary to impart design properties, the barrier laminate material shown in FIG. 3 cannot be printed on the intermediate layer. In addition, since the sanitary printing process is not performed on the innermost layer side on which the food is placed, there is only a method of printing on the base material side.

JP 2004-115116 A JP2001-158067

  When a tray (container) composed of the laminate shown in FIG. 3 is viewed from above, the printed layer 16 is below the plurality of layers, and each resin layer reflects light with a different refractive index. Therefore, it has been found that there is a difficulty in the clarity of the print information of the print layer. That is, it was considered that if the resolution of the information drawn on the inner surface of the container is low and the resolution is higher, the product appealing power by the information will increase.

  Therefore, the problem to be solved by the present invention is to provide a laminate and a container that have high clarity of written information and are inexpensive.

The present invention
It comprises an olefin-based layer, a printed layer, a gas barrier layer, and a substrate layer, and the olefin-based layer, the printed layer, the gas barrier layer, and the substrate layer are sequentially laminated. Proposed laminate material.

  The present invention proposes a laminated material, wherein the laminated material is characterized in that the olefin-based layer is preferably an unstretched film.

  The present invention proposes a laminated material, wherein the surface of the olefin-based layer on the side facing the printed layer is preferably subjected to a discharge treatment.

  The present invention proposes a laminate material, wherein the laminate material is characterized in that the thickness of the olefin-based layer is preferably 10 to 50 μm.

  The present invention is the laminate, wherein the gas barrier layer is preferably a single layer of a resin selected from the group consisting of a polyvinyl alcohol resin, an ethylene-vinyl alcohol copolymer, a vinylidene chloride resin, and an amide resin. Proposed is a laminated material comprising two or more layers.

  The present invention proposes a laminate material, wherein the laminate material is characterized in that a thickness of the gas barrier layer is preferably 5 to 25 μm.

  The present invention proposes a laminate material which is the laminate material, wherein the gas barrier layer is preferably laminated via an adhesive layer.

  The present invention proposes a container material that is the laminated material.

  The present invention proposes a container characterized in that the laminated material is configured so that the olefin-based film is positioned inside the container.

  Excellent clarity and visibility of printed information on the printed layer. That is, it is possible to obtain a container having excellent design properties while having a gas barrier property.

  Since the number of laminated materials is small, it can be obtained easily and at low cost.

Schematic cross section of the container Schematic sectional view of the laminated material of the present invention Schematic cross section of conventional laminate

Hereinafter, embodiments of the present invention will be described.
The first invention is a laminated material. The laminated material includes an olefin film as an olefin layer, a printed layer, a gas barrier film as a gas barrier layer, and a base material layer. The olefin-based film, the printing layer, the gas barrier film, and the base material layer are sequentially laminated. The printed layer is provided between the olefin-based film constituting the innermost layer and the gas barrier film. The base material layer is provided on the surface of the gas barrier film opposite to the printing layer. Such a laminate is molded into a desired shape to form a container.

  The olefin film as the olefin layer was preferably an unstretched film. Non-stretched film refers to a film that has not been stretched, and stretched here refers to stretching (stretching) a certain direction while heating the synthetic resin film to some extent, and is expected to improve strength. Indicates the processing to be performed. When the laminated material (the olefinic film) is such an unstretched film, the unstretched olefinic film present on the surface (inner surface) was hardly damaged when the laminate was formed into a container such as a tray. The olefin film is not thick. For example, it was 10-50 micrometers. More preferably, it was 15-40 micrometers. More preferably, it was 10-30 micrometers. Even if the thickness of the olefin-based film present on the surface was thin, the surface layer was hardly broken when it was an unstretched film. In particular, when an unstretched film made of polypropylene was used for the surface layer, it had moderate waist, heat sealability, good mechanical properties, and was excellent in moisture resistance and wear resistance (not easily scratched). Therefore, it was particularly preferable. The olefin film is preferably an easy peel film. An easy peel film refers to a film imparted with easy-openability. When an easy-peel film is used, after sealing the gas barrier properties shown in FIG. 1 onto the container, a smooth peeling feeling and a beautiful peeling surface can be obtained when peeling, and a wide range of heat A stable peel strength was obtained at the sealing temperature. Therefore, when a container such as a tray is formed using a laminated material in which the olefin-based film is an easy peel film, the preferred features as described above are exhibited. It is more preferable that the olefin-based film (easy peelable film) is an unstretched film. The surface of the olefin film on the side facing the printing layer is preferably subjected to a discharge treatment (for example, a corona discharge treatment). By the discharge treatment, the adhesive force (integration force) between the olefin-based film and the print layer (print coat layer) was improved.

  Although the printing layer is on the lower side (base material side) than the olefin film (surface layer), it is on the upper side of the gas barrier film. It is the olefin-based film that is on the printed layer (side closer to the eyes). The olefin film is thin. The transparency of the olefin film is good. Therefore, the degree to which the clarity and visibility of the printed layer is disturbed is very small. For example, compared with the case where the composite layer (refer FIG. 3) called the olefin resin layer 11-adhesive layer 12-gas barrier layer 13-adhesive layer 14-olefin resin layer 15 exists on the printing layer 16. The visibility of the printing layer (printing) was remarkably good. In addition, since the layer structure is simple, the cost of the laminated material is low. The present invention is greatly characterized in that the printing layer is provided on the upper side (surface side: the side opposite to the substrate) than the gas barrier film. The printing layer is mainly composed of one or more ink vehicles. If necessary, one or more of plasticizers, stabilizers, antioxidants, light stabilizers, UV absorbers, curing agents, crosslinking agents, lubricants, antistatic agents, fillers, and other additives. Are optionally added. Further, a colorant such as a dye / pigment is added to prepare an ink composition that is sufficiently kneaded in a solvent, a diluent or the like. This ink composition is used, for example, gravure printing, offset printing, letterpress printing, screen printing, transfer printing, flexographic printing, and other printing methods are used. On the corona discharge treatment surface of the olefin film, characters, graphics , Symbols, patterns, and other appropriate printed patterns are printed to form a printed layer. Here, depending on the amount of patterns, character information, and the like, there is a portion where the printed layer is not formed on the laminated material. That is, in the laminated material of the present invention, it is sufficient that a printed layer is formed on at least a part of the laminated material. For example, the printed layer may be formed on 5% or more of the entire surface area. The print layer may be formed on 20% or more, 50% or more, 70% or more, 80% or more, 90% or more, or 100% (entire layer of the entire laminate) of the total surface area of the laminate.

The gas barrier film as the gas barrier layer is not particularly limited as long as the gas permeability such as oxygen gas, water vapor gas, carbon dioxide gas is low, and specifically, the oxygen permeability of the oxygen barrier film material. Is less than 1000 ml / m ² · 24 hr · MPa (75% RH at 20 ° C.) (preferably less than 100 ml / m ² · 24 hr · MPa (75% RH at 20 ° C.) at 25 μm thickness). It was. For example, any resin of polyvinyl alcohol resin (PVOH), ethylene-vinyl alcohol copolymer (EVOH), vinylidene chloride resin (PVDC), amide resin (for example, nylon etc.) is mentioned. These layers made of resin are composed of one layer or two or more layers. The gas barrier film had a thickness of preferably 5 to 25 μm. More preferably, it was 7-23 micrometers. More preferably, it was 10-20 micrometers or more. If the container has a gas barrier property, it is difficult for oxygen to enter the container after heat-sealing the cover material having the gas barrier property, the oxidation of the food placed in the container is slowed, and the deterioration of the food is reduced. It was late.

  The base material layer is made of an appropriate resin material. For example, it is made of a foamed resin material (for example, a polypropylene foam material, a polystyrene foam material, a foamed material of a polymer mixed resin of polypropylene and polystyrene). Alternatively, it is composed of an unfoamed resin material (for example, an unfoamed polypropylene material, an unfoamed polystyrene material, etc.). Preferably, it is a foam material from a lightweight viewpoint. Although there will be no restriction | limiting in particular if the thickness of a base material layer is equipped with the intensity | strength when it is set as a container, and the heat insulation expected, It should just be 100-5000 micrometers.

  An adhesive layer may be formed between the base material layer and the gas barrier layer. That is, the gas barrier layer may be laminated on the base material layer via the adhesive layer. Here, the type, material, and thickness of the adhesive layer are not particularly limited as long as the adhesive strength between the gas barrier layer and the base material layer is expected.

  Next, the manufacturing method of a laminated body is demonstrated. In order to obtain a laminated material according to the present invention, first, a step of preparing an olefin film as an olefin layer, a step of forming a printing layer on one side of the olefin film, and an olefin on which the printing layer is formed It is only necessary to provide a method for producing a multilayer laminate film comprising a step of laminating a gas barrier film on an adhesive film via an adhesive to obtain a multilayer laminate film. The method for producing a multilayer laminate film may further include a step of performing a discharge treatment in advance on a printing surface on which a printed layer of the olefin film is formed. According to such a process, the adhesive force between the olefin-based film and the printed layer is improved. The step of laminating a gas barrier film through an adhesive to obtain a multilayer laminate film may be a dry laminating method using a solvent-based adhesive or a reactive adhesive as an adhesive. What is necessary is just to provide the manufacturing method of a laminated material provided with the process of laminating | stacking the multilayer laminated film obtained by the said method, and a base material layer, and obtaining a laminated material. In the method for producing a laminated material, the multilayer laminated film and the base material layer may be laminated via an adhesive layer.

  The thickness of the multilayer laminate film is not particularly limited as long as it has a low gas permeability such as oxygen gas, water vapor gas, and carbon dioxide gas, and has a printing layer. For example, the thickness may be 10 to 60 μm. What is necessary is just 15-55 micrometers, and what is necessary is just 20-50 micrometers. If the multilayer laminate film exceeds 60 μm, there is a concern that when the multilayer laminate film is laminated on the base material layer as described above, there may be a problem that the multilayer laminate film cannot be pasted due to lack of heat. There is a concern that the sexuality cannot be obtained.

  The second invention is a container material. The container material is the laminated material. Such a laminate is molded into a desired shape to obtain a container.

  The third invention is a container. The said container is the said laminated material, and is comprised so that the said olefin-type film may be located inside a container. Such a container may be used as a container for containing food or foodstuffs. That is, the container of the present invention may be a food container. The thickness of the container is not particularly limited as long as it has strength and expected heat insulation properties, but may be 100 to 5000 μm.

As shown in FIG. 1, the container of the present invention may be used by attaching a lid material to a flange formed in the container. Such a lid member is preferably provided with a gas barrier layer imparting gas barrier properties. Here, the gas barrier layer is not particularly limited as long as the gas permeability of, for example, oxygen gas, water vapor gas, carbon dioxide gas is low. Specifically, the oxygen permeability of the oxygen barrier film material is 1000 ml with a thickness of 25 μm. / M ² · 24 hr · MPa (75% RH at 20 ° C.) or less, preferably 100 μl / m ² · 24 hr · MPa (75% RH at 20 ° C.) at 25 μm thickness. Further, the container may be sealed with nitrogen gas, carbon dioxide gas, oxygen gas or a mixed gas containing two or more of them and then sealed (top-sealed) with a lid material. According to such a method of use, it is expected to maintain the freshness of foods that are easily corroded and extend the expiration date.

  Hereinafter, more specific embodiments will be mentioned. However, the present invention is not limited to the following examples. Various modifications and application examples are also included in the present invention as long as the features of the present invention are not greatly impaired.

[Example 1]
A laminate A shown in FIG. 2 (cross-sectional view) was produced.

  Reference numeral 1 denotes an unstretched polypropylene film constituting the laminated material A. When the laminated material A is formed into a container (for example, a tray), the film 1 constitutes the innermost layer (the uppermost layer: the food material is placed on the surface of this layer) of the container (for example, the tray). The thickness of the film 1 is 20 μm. The lower surface of the film 1 (the surface facing the surface in contact with the food material) was subjected to a print fixing property improving process such as a corona discharge process.

  Reference numeral 2 denotes a printing layer. The printing layer 2 is mainly composed of an ink vehicle. One or more of plasticizers, stabilizers, antioxidants, light stabilizers, ultraviolet absorbers, curing agents, crosslinking agents, lubricants, antistatic agents, fillers, and other additives, Added. In addition, a colorant was added. The solvent was added and kneaded thoroughly. Thereby, an ink composition was prepared. Using this ink composition, printing (coating) was performed on the corona discharge treated surface of the resin layer 1. Thereby, the printing layer 2 was provided on the lower surface (discharge treatment surface) of the film 1.

  3 is an adhesive layer.

  4 is an EVOH (gas barrier resin) film. The thickness of the resin layer 4 was 15 μm.

  Reference numeral 5 denotes an adhesive layer.

  6 is a base material (polystyrene foam).

  A tray was formed using the laminated material. The upper surface of the tray (the surface facing the surface in contact with the food) is an unstretched polypropylene film 1.

[Comparative Example 1]
A laminated material B shown in FIG. 3 (cross-sectional view) was produced.
Laminate B shown in FIG. 3 (11 = 15 μm thick polypropylene resin layer, 12 = adhesive layer, 13 = 5 μm thick EVOH resin layer, 14 = adhesive layer, 15 = 20 μm thick polypropylene resin layer, 16 = A tray was molded using a printed layer, 17 = adhesive layer, 6 = polystyrene foam.

[Characteristic]
Regarding the laminated material constituting the trays of the above examples, the haze value (the smaller the numerical value, the higher the transparency) and the L ^* value (color difference: the smaller the numerical value, the blacker the whiteness, the larger the numerical value) were examined. For measuring the haze value, TC-HIIIDPK manufactured by TOKYO DENSHOKU was used. For measurement of the L * value, MODEL 968 manufactured by X-Rite was used. It means that the smaller the haze value and L ^* value, the higher the clarity / recognition by eyes. The above haze value and L ^* value were investigated for films up to the upper layer of the printing layer. The L ^* value was determined by placing the film on a black sheet. The laminated material of Example 1 had a haze value of 0.5 and an L ^* value of 14.09. In contrast, the laminate of Comparative Example 1 had a haze value of 3.3 and an L ^* value of 21.82. Incidentally, the L ^* value of the black sheet was 10.80. As can be seen from this data, the laminated material according to the present invention can clearly recognize the information of the printed layer, but the laminated material according to Comparative Example 1 is much inferior to the laminated material according to the present invention. I can see that it looks blurred.

  Furthermore, when the laminated material according to the above example was formed into a tray, the surface layer was hardly broken. That is, the yield of good products was high. It was also excellent in heat sealability and mechanical properties (durability) when covered with a cover material having barrier properties. Since the laminated material of the present invention has a small number of laminated layers, it was obtained simply and at a low cost. In the laminated material of the example, when the example and the comparative example are compared, the adhesive layer located on the base material layer is located far from the surface on which the food is placed, and the adhesive layer is far from the surface. Therefore, it is also rich in safety.

A Laminate 1 Unstretched polypropylene film 2 Print layer 3 Adhesive layer 4 EVOH (gas barrier resin) film 5 Adhesive layer 6 Polystyrene foam (base material)
7 Multi-layer laminate film (1-5)
B Laminated material 11 Polypropylene resin layer 12 Adhesive layer 13 Gas barrier resin layer 14 Adhesive layer 15 Polypropylene resin layer 16 Print layer 17 Adhesive layer 21 Cover material having gas barrier properties

Claims (9)

  It comprises an olefin-based layer, a printed layer, a gas barrier layer, and a substrate layer, and the olefin-based layer, the printed layer, the gas barrier layer, and the substrate layer are sequentially laminated. Laminated material.   The laminated material according to claim 1, wherein the olefin-based layer is an unstretched film.   The laminated material according to claim 1 or 2, wherein the surface of the olefin-based layer on the side facing the print layer is subjected to a discharge treatment.   The thickness of the said olefin type layer is 10-50 micrometers, The laminated material in any one of Claims 1-3 characterized by the above-mentioned.   The gas barrier layer is a layer made of any one of a polyvinyl alcohol resin, an ethylene-vinyl alcohol copolymer, a vinylidene chloride resin, and an amide resin, and is composed of one layer or two or more layers. The laminated material in any one of Claims 1-4.   The laminated material according to any one of claims 1 to 5, wherein the gas barrier layer has a thickness of 5 to 25 µm.   The said gas barrier layer is laminated | stacked through an adhesive bond layer, The laminated material in any one of Claims 1-6 characterized by the above-mentioned.   It is a laminated material as a container material, The laminated material in any one of Claims 1-7 characterized by the above-mentioned. The container according to any one of claims 1 to 8, wherein the olefin-based layer is positioned inside the container.

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