JP6485993B2 - Lid and its manufacturing method - Google Patents

Description

  The present invention relates to a lid material and a manufacturing method thereof. In particular, lids for packaging foods, beverages, pharmaceuticals, cosmetics, chemicals, etc. More specifically, lids for containers such as yogurt, jelly, pudding, syrup, retort foods such as porridge and soup, and chemicals The present invention relates to a lid used for a storage container for liquids such as goods and pharmaceuticals, semi-solids, and gel substances, and a method for producing the same.

  Ordinary lids are difficult to remove due to adhesion of the contents, and often cause waste or dirt of the contents. In addition, when a fluorine material or silicone is used, although it has water repellency and adhesion prevention effects, it has poor heat sealing properties and is difficult to use as a lid material.

  In order to solve these problems, a layered product having a base material layer and a thermal adhesive layer, the thermal adhesive layer being laminated as the outermost layer on one side, and primary particles on the outermost side not adjacent to the other layer Hydrophobic oxide fine particles having an average diameter of 3 to 100 nm are attached, and the hydrophobic oxide fine particles form a porous layer having a three-dimensional network structure. There is a lid material made of hydrophobic silica or the like (Patent Document 1).

  In order to develop hydrophobicity, the lid material has hydrophobic oxide fine particles attached to the outermost surface, and uses hydrophobic silica having a trimethylsilyl group on the surface of the hydrophobic oxide fine particles. However, in the above-described lid material, there is a possibility that the hydrophobic oxide fine particles may impair the sealing property, and a sufficient adhesion preventing effect cannot be obtained for the contents containing a large amount of milk fat and oil.

  Known documents are shown below.

Japanese Patent No. 4348401

  The present invention has been made in view of the above-described circumstances, and provides a lid material that has a good sealing property and that can provide a sufficient anti-adhesion effect even for contents containing a large amount of milk fat and oil. . Another object is to provide a manufacturing method thereof.

The invention according to claim 1 of the present invention is a lid for a container for storing yogurt having a milk fat content of 2.0% to 4.0%, comprising a base material layer, an ethylene vinyl acetate copolymer hot melt Layer, an anti-adhesion seal layer are sequentially laminated, and the anti-adhesion seal layer is made of a water-dispersed modified polyolefin resin in which hydrophobic silica particles surface-treated with a perfluoroalkylsilane coupling agent are dispersed,
The particle size of the hydrophobic silica particles is 1.0 μm or less in terms of the particle size at an integrated value of 50% in the particle size distribution determined by the laser diffraction / scattering method,
Unevenness is provided from the surface of the adhesion preventing seal layer, and the height difference of the unevenness is 5 μm or more and 100 μm or less,
Has good anti-adhesive properties for yogurt with a milk fat content of 4.0% and
It is a lid material characterized by having good sealing properties .

  The invention according to claim 2 of the present invention is the method for producing a lid according to claim 1, wherein a surface of the hot melt layer is coated with an aqueous dispersion of a modified polyolefin resin with a fluorine-based silane coupling agent. Immediately after applying and drying the coating liquid in which the surface-treated hydrophobic silica particles are dispersed, the plate is pressed with a plate having a plate depth of 5 μm or more and 100 μm or less, and the anti-adhesion seal layer having irregularities on the surface is provided. It is the manufacturing method of the lid | cover material characterized by providing.

  The lid material of the present invention has a good sealing property and has a sufficient adhesion preventing effect even for contents containing a large amount of milk fat and oil. In addition, according to the method for producing a lid material of the present invention, the above-mentioned lid material having a good sealing property and having a sufficient anti-adhesion effect even for contents containing a large amount of milk fat or oil is obtained. It is done.

It is explanatory drawing which showed typically the layer structure of an example of the cover material of this invention in the cross section. It is explanatory drawing which showed typically the layer structure of the other example of the cover material of this invention in the cross section.

  Hereinafter, modes for carrying out the present invention will be described.

FIG. 1 is an explanatory diagram schematically showing a cross-sectional view of an example of the layer structure of the lid member of the present invention.
A lid 100 according to an example of the present invention includes a base material layer 1, a hot melt layer 2, and an adhesion preventing seal layer 3 from the outer layer side. The adhesion preventing seal layer 3 is made of a modified polyolefin resin 5 in which hydrophobic silica particles 4 surface-treated with a fluorine-based silane coupling agent are dispersed.

  The thickness of the adhesion preventing seal layer 3 is desirably 1 μm or more and 10 μm or less, and unevenness is provided from the surface of the adhesion preventing seal layer 3 to the hot melt layer 2. It is desirable that the height difference of the unevenness is 5 μm or more and 100 μm or less.

  The lid material 100 of this example is obtained by melting a hot melt in a base material layer 1 and applying it to provide a hot melt layer 2. Applying a coating liquid in which hydrophobic silica particles 4 surface-treated with an agent are mixed and dispersed, and then drying and pressing from the adhesion preventing surface to provide unevenness and providing an adhesion preventing seal layer 3 I can do it.

  The unevenness on the surface of the anti-adhesion seal layer 3 can be provided by applying a coating liquid and drying it in-line, by pressing and transferring it with a roll engraved with a reverse pattern of unevenness on the surface. Since it can do without increasing, it is preferable. As a pattern, it is preferable that the concave portions on the surface of the adhesion preventing seal layer 3 have a lattice shape or a turtle shell shape.

FIG. 2 is an explanatory view schematically showing in cross section the layer structure of another example of the lid member of the present invention.
In the lid member 200 of this example, a printing layer 6 and a barrier layer 7 are provided between the base material layer 1 and the hot melt layer 2. An adhesive layer 8 is provided between the printing layer 6 and the barrier layer 7, and an adhesive layer 9 and a polyolefin layer 10 are provided between the barrier layer 7 and the hot melt layer 2. An adhesion preventing seal layer 3 is provided on the surface of the polyolefin layer 2. Further, unevenness is provided from the surface of the adhesion preventing seal layer 3 to the hot melt layer 2. The height difference of the irregularities is desirably 5 μm or more and 100 μm or less.

  The lid member 200 of this example is provided with the printing layer 6 on one side of the base material layer 1, applying the adhesive of the adhesive layer 8 on the surface of the printing layer 6, and laminating the barrier layer 7 by dry lamination, An anchor coat agent for the adhesive layer 9 is applied to the surface of the barrier layer 7, and the polyolefin layer 10 is provided by extrusion lamination.

Next, a melted hot melt is applied to provide a hot melt layer 2. Hydrophobic silica particles whose surface is treated with a fluorine-based silane coupling agent on an aqueous dispersion of modified polyolefin on the surface of the hot melt layer 2. After applying the coating liquid in which 4 is mixed and dispersed, it is dried and pressed from the adhesion preventing surface, thereby providing irregularities and providing the adhesion preventing seal layer 3.

  The unevenness on the surface of the anti-adhesion seal layer 3 can be provided by applying a coating liquid and drying it in-line, by pressing and transferring it with a roll engraved with a reverse pattern of unevenness on the surface. Since it can do without increasing, it is preferable. As a pattern, it is preferable that the concave portions on the surface of the adhesion preventing seal layer 3 have a lattice shape or a turtle shell shape.

  The base material layer 1 of the lid member 100 is made of either paper and plastic film or a laminate of paper and plastic film. When paper is provided on the base material layer 1, a print layer can be provided on the outer surface of the paper. The paper to be used can be appropriately selected from fine paper, coated paper, art paper, cast coated paper, imitation paper, craft paper and the like. Moreover, you may use barrier films, such as an inorganic oxide vapor deposition film, as the base material layer 1 of the cover material 100. FIG.

  The base material layer 1 of the lid member 200 is made of a plastic film. As the plastic film used for the base material layer 1 of the lid member 100 or the lid member 200, a stretched or unstretched film such as polyethylene terephthalate, nylon, polypropylene, polyethylene, or a cellophane film can be appropriately selected.

  The hot melt used for the hot melt layer 2 may be polyester or modified polyolefin, but EVA (ethylene vinyl acetate copolymer) is preferably used.

The hydrophobic silica particles 4 used for the adhesion preventing seal layer 3 are hydrophobic silica particles surface-treated with a fluorine-based silane coupling agent. As the fluorine-based silane coupling agent for surface-treating silica particles, a silane coupling agent having a fluoroalkyl group (CF ₃ (CF ₂ ) n—) as a hydrophobic group can be used. For example, trifluoropropyltrialkoxysilane, heptadecafluorodecyltrialkoxysilane, and the like can be used.

  The particle diameter of the hydrophobic silica particles surface-treated with the fluorine-based silane coupling agent is preferably 1.0 μm or less in terms of the particle diameter at an integrated value of 50% in the particle size distribution obtained by the laser diffraction / scattering method. it can.

  The modified polyolefin resin 5 is desirably a polyolefin in which the modification of the modified polyolefin is acid modification and is modified with an unsaturated carboxylic acid or an anhydride thereof. Further, as the olefin of polyolefin, ethylene, propylene, 1-butene, 1-pentene, 1-hexene and the like are desirable.

  The print layer 6 provided on the lid member 200 is provided by printing on the back surface of the base material layer 1. As a method of providing the printing layer 6, it can be provided by a known printing method such as gravure printing or flexographic printing with an ink corresponding to the material of the base material layer 1.

  For the barrier layer 7, a metal foil such as an aluminum foil, or a deposited film obtained by depositing a metal such as aluminum or tin, or a metal oxide such as silica or alumina on a base film is used. When a transparent metal oxide vapor deposition film is used as the barrier layer 7, it may also serve as the base material layer 1. In this case, the barrier layer 7, the print layer 6, the adhesive layer 9, the polyolefin layer 10, the hot melt layer 2, and the adhesion preventing seal layer 3 are laminated in this order.

The adhesive layer 8 is used for laminating the barrier layer 7 on the surface of the printing layer 6 of the base material layer 1 provided with the printing layer 6. As a lamination method, dry lamination (including non-solvent) is preferable, and as an adhesive to be used, an adhesive for dry lamination and a solventless adhesive are preferably used. The adhesive is selected depending on the material of the base material layer 1, and a urethane-based adhesive can be preferably used.

  The adhesive layer 9 is used when the polyolefin layer 10 is laminated. When the polyolefin layer 10 is provided by extrusion lamination, an anchor coat agent for extrusion lamination is used. Moreover, when providing the polyolefin layer 10 with a film, the adhesive agent similar to the adhesive bond layer 8 is used.

  The polyolefin layer 10 is advantageously provided by extrusion lamination rather than using a film in terms of cost. As the polyolefin used in the polyolefin layer 10, polyethylene resins such as polyethylene and copolymers thereof, polypropylene, and the like can be used. When an EVA hot melt is used for the hot melt layer 2, a polyethylene resin such as polyethylene can be preferably used because of its adhesiveness to the hot melt layer 2.

  Specific examples of the present invention will be described below.

<Example 1>
A printing layer 6 is provided on the corona-treated surface of the biaxially stretched polyethylene terephthalate film 12 μm of the base material layer 1 by gravure printing using urethane-based ink. The aluminum foil of the barrier layer 7 was laminated on the surface of the adhesive layer 8 provided by applying a system adhesive.

A urethane-based anchor coat agent was applied to the aluminum foil surface of the barrier layer 7 with an extrusion laminator to extrude low density polyethylene (density: 0.915 g / cm ³ , MFR: 15), and a polyolefin layer of 15 μm. 10 was prepared to produce a laminate of intermediate products.

An EVA-based hot melt is melted and applied on the surface of the polyolefin layer 10 of this laminate to provide a hot melt layer 2 (coating amount: 30 g / m ² ). Further, an in-line is provided on the surface of the hot melt layer 2. Then, the coating solution for the adhesion preventing seal layer 3 was applied.

  The coating solution for the anti-adhesion seal layer 3 includes water-dispersed modified polyolefin resin and hydrophobic silica particles (particle size: 0.1 μm) surface-treated with a perfluoroalkylsilane coupling agent having the same solid weight. The mixture was mixed at a weight ratio and diluted with isopropyl alcohol.

  Thereby, the adhesion preventing seal layer 3 in which the hydrophobic silica particles 4 were dispersed in the modified polyolefin resin 5 was provided with a thickness of 5 μm. Immediately after coating and drying, the roll surface was provided with a plate having a concavo-convex pattern of a plate depth of 30 μm and pressed from the adhesion preventing seal layer 3 side to transfer the plate irregularities from the surface of the adhesion preventing seal layer 3. The lid material of Example 1 was created as described above.

  Below, the comparative example of this invention is demonstrated.

<Comparative Example 1>
Instead of using hydrophobic silica particles (particle diameter: 0.1 μm) surface-treated with a perfluoroalkylsilane coupling agent in the coating solution for the anti-adhesion seal layer 3, silica particles (particle diameter) whose surface is trimethylsilylated : 40 nm) in the same manner as in Example 1, except that
The lid material of Comparative Example 1 was created.

<Comparative example 2>
A cover material of Comparative Example 2 was prepared in the same manner as in Example 1 except that the plate of the roll to be pressed immediately after application of the anti-adhesion seal layer 3 and drying was changed to a plate depth of 4 μm with irregularities in a lattice shape.

<Test method>
The lid materials of the example and the comparative example were tested by the following method and evaluated for comparison.

<Yogurt repellent 1>
Prepare a paper cup with a polyethylene layer on the inner surface, fill it with yogurt (plain, milk fat content 2.0%), seal the lids of the example and the comparative example to the flange part of the paper cup, After turning over, the lid material was peeled and opened, and the yogurt repellency of the lid material was evaluated. The evaluation was ◎ for those that flicked cleanly, ◯ for the lid material that had almost repelled, △ for the lid material that did not repel a little, and × for the lid material that hardly flew, and the results are shown in Table 1. Summarized.

<Yogurt repellent 2>
The yogurt repellency 2 was evaluated in the same manner as the yogurt repellency test 1 except that plain yogurt having a milk fat content of 4.0% was used. The results are summarized in Table 1.

<Sealability>
In the test for water repellency and yogurt repellency, when the cover plate sealed with a hot plate was peeled and opened, its adhesion, peel and open were evaluated. The case where there was no problem in adhesion, peeling, and opening was evaluated as ○, and the case where there was a problem was evaluated as ×. The results are summarized in Table 1.

以下に、実施例と比較例との比較結果について説明する。

Below, the comparison result of an Example and a comparative example is demonstrated.

<Comparison result>
The lid material of Example 1 repels both yogurt with a milk fat content of 2.0% and yogurt with a milk fat content of 4.0%. It was.

  On the other hand, the lid material of the comparative example had no problem with the sealing property, but the lid material of the comparative example 1 is good for yogurt with a milk fat content of 2.0%. For yogurt with a milk fat content of 4.0%, almost no repelling was possible.

  Moreover, although the cover material of the comparative example 2 was almost repelling with respect to the yogurt of milk fat content 2.0%, it was inferior to Example 1 or the comparative example 1. FIG. In addition, yogurt with a milk fat content of 4.0% was hardly repelled and was impossible.

DESCRIPTION OF SYMBOLS 100, 200 ... Cover material 1 ... Base material layer 2 ... Hot melt layer 3 ... Adhesion prevention seal layer 4 ... Hydrophobic silica particle 4
5 ... Modified polyolefin resin 6 ... Print layer 7 ... Barrier layer 8 ... Adhesive layer 9 ... Adhesive layer 10 ... Polyolefin layer

Claims (2)

A lid for containers containing yogurt with a milk fat content of 2.0% or more and 4.0% or less, wherein a base material layer, an ethylene vinyl acetate copolymer hot melt layer, and an anti-adhesion seal layer are sequentially laminated. The adhesion preventing seal layer is made of a water-dispersed modified polyolefin resin in which hydrophobic silica particles surface-treated with a perfluoroalkylsilane coupling agent are dispersed,
The particle size of the hydrophobic silica particles is 1.0 μm or less in terms of the particle size at an integrated value of 50% in the particle size distribution determined by the laser diffraction / scattering method,
Unevenness is provided from the surface of the adhesion preventing seal layer, and the height difference of the unevenness is 5 μm or more and 100 μm or less,
A lid material having a good anti-adhesion property for yogurt having a milk fat content of 4.0% and a good sealing property for a container .   The method for producing a lid according to claim 1, wherein hydrophobic silica particles surface-treated with a fluorine-based silane coupling agent are dispersed in an aqueous dispersion of a modified polyolefin resin on the surface of the hot melt layer. Immediately after the coating liquid is applied and dried, the cover is pressed with a plate having a plate depth of 5 μm or more and 100 μm or less, and the anti-adhesion seal layer having unevenness on the surface is provided. .

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