JP2014156039A - Lid material and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lid material having excellent sealability, capable of obtaining a sufficient adhesion preventive effect even with a content having excessive milk fats or oils, and a manufacturing method thereof.SOLUTION: A lid material includes a substrate layer 1, a hot-melt layer 2 and an adhesion prevention seal layer 3 sequentially laminated. The adhesion prevention seal layer includes a modified polyolefin resin 5 with polytetrafluoroethylene particles 4 of a particle size 1.0 μm or smaller dispersed therein. Unevenness is formed from a surface of the adhesion prevention seal layer. A difference of elevation of the unevenness is 5-100 μm.

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, 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 There is a cover material in which hydrophobic oxide fine particles having an average diameter of 3 to 100 nm are adhered, and the hydrophobic oxide fine particles form a porous layer having a three-dimensional network structure (Patent Document 1).

  The lid material uses hydrophobic oxide fine particles in order to develop hydrophobicity, but a sufficient adhesion preventing effect was not obtained with respect to 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.

  In the invention according to claim 1 of the present invention, a base material layer, a hot melt layer, and an anti-adhesion seal layer are sequentially laminated, and the anti-adhesion seal layer comprises polytetrafluoroethylene particles having a particle diameter of 1.0 μm or less. A lid material comprising a modified modified polyolefin-based resin dispersed, provided with irregularities from the surface of the adhesion-preventing seal layer, and having a height difference of 5 μm or more and 100 μm or less.

  The invention according to claim 2 of the present invention is the method for producing a lid material according to claim 1, wherein polytetrafluoroethylene particles are dispersed in an aqueous dispersion of a modified polyolefin resin on the surface of the hot melt layer. Immediately after applying and drying the applied coating liquid, pressing with a plate having a plate depth of 5 μm or more and 100 μm or less to provide the adhesion preventing seal layer having irregularities on the surface is provided. Is the method.

  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 polytetrafluoroethylene particles 4 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. The height difference of the irregularities is desirably 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, and on the surface of the hot melt layer 2, an aqueous dispersion of modified polyolefin and polytetrafluoroethylene particles By applying a coating solution in which 4 is mixed and dispersed, drying, and pressing from the adhesion preventing surface, the adhesion preventing seal layer 3 with irregularities can be provided.

  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 hot melt layer 2 is provided by applying a molten hot melt, and a coating solution in which polytetrafluoroethylene particles 4 are mixed and dispersed in an aqueous dispersion of modified polyolefin on the surface of the hot melt layer 2. Is applied, dried, and pressed from the adhesion preventing surface, whereby the adhesion preventing seal layer 3 having irregularities can be provided.

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 polytetrafluoroethylene particles 4 used for the adhesion preventing seal layer 3 may be those commercially available as a dry powder. The particle diameter of the polytetrafluoroethylene particles 4 is preferably a particle diameter at an integrated value of 50% in the particle size distribution determined by a laser diffraction / scattering method, and a particle diameter of 1.0 μm or less can be preferably used. Incidentally, dry powder of polytetrafluoroethylene particles having a particle diameter of less than 0.1 μm is difficult to obtain and difficult to use in this application.

  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 a barrier layer on the surface of the printing layer of the base material layer 1 provided with the printing layer. 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 polyolefin used for the polyolefin layer 10, polyethylene resin, such as polyethylene and its copolymer, polypropylene, etc. 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: 25 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.

  In the coating solution for the anti-adhesion seal layer 3, polytetrafluoroethylene particles 4 (particle diameter: 0.3 μm) are mixed with water-dispersed modified polyolefin resin so that the solid content weight is the same weight ratio. It was.

  Thereby, the adhesion preventing seal layer 3 in which the polytetrafluoroethylene 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 is provided with a plate having a concave and convex grid shape 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>
Implementation was carried out except that polytetrafluoroethylene particles 4 (particle size: 0.3 μm) were used in the coating solution for the adhesion prevention seal layer 3 instead of silica particles (particle size: 40 nm) whose surface was trimethylsilylated. In the same manner as in Example 1, a cover material of Comparative Example 1 was prepared.

<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 ... Polytetrafluoroethylene particle 5 ... Modified polyolefin resin 6 ... -Print layer 7 ... Barrier layer 8 ... Adhesive layer 9 ... Adhesive layer 10 ... Polyolefin layer

Claims (2)

  A base material layer, a hot melt layer, and an adhesion preventing seal layer are sequentially laminated, and the adhesion preventing seal layer is made of a modified polyolefin resin in which polytetrafluoroethylene particles having a particle diameter of 1.0 μm or less are dispersed, A lid material, wherein irregularities are provided from the surface of the adhesion preventing seal layer, and the height difference of the irregularities is 5 μm or more and 100 μm or less.   It is a manufacturing method of the lid | cover material of Claim 1, Comprising: Immediately after apply | coating and drying the coating liquid which disperse | distributed the polytetrafluoroethylene particle | grains to the water dispersion of the modified polyolefin resin on the surface of the said hot-melt layer A method for producing a lid material, comprising pressing the plate with a plate having a plate depth of 5 μm or more and 100 μm or less, and providing the adhesion preventing seal layer having irregularities on the surface.

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