JP2009102038A - Paper container - Google Patents

Abstract

[Problem] To provide a paper container having a barrier property excellent in surface glossiness and cosmetics, and excellent in workability during container molding.
A paper made by using a laminated material in which an unstretched polyolefin resin layer 12 is provided on the inner surface side of a paper substrate 11 and a uniaxially stretched polyolefin resin layer 13 having a glossiness of 70% or more is provided on the outer surface side as a body member 2. In the container, further, when one end edge 2a of the body member is overlapped with the other end edge 2b and formed into a cylindrical shape, the side end edge 2a located inside the overlapping portion extends from the paper base material. The extended resin portion 14 is folded back to the uniaxially stretched polyolefin resin surface side, and the folded portion is thermally bonded to the uniaxially stretched polyolefin resin layer surface overlapping the paper base material and unstretched located on the inner surface side of the other side edge It is thermally bonded to the polyolefin resin layer, and one end edge and the other end edge of the body member are enveloped together.
[Selection] Figure 2

Description

  The present invention relates to a paper container for storing a liquid material such as coffee or juice, and more particularly to a paper container capable of storing a liquid material excellent in gloss, cosmetics, and heat sealability for a long period of time.

  Conventionally, paper containers such as bricks, gable tops, and paper cups have been distributed as paper containers for filling liquids such as juice and coffee. In this case, the body portion of the paper container is generally made of a laminated material having a layer structure of a paper base / aluminum foil / polyethylene terephthalate film / polyethylene layer provided with a polyethylene layer / printing layer from the outside. It was. As described above, since the printed layer is provided on the front side of the paper base material, the reproducibility of fine patterns is inferior, the transparency of the polyethylene layer on the surface is not good, and the cosmetic layer is excellent because it is easily damaged. It was hard to say.

  Accordingly, there is a demand for a display effect at a store such as one having excellent reproducibility of the pattern layer or one having a glossy surface to enhance the pattern.

And as a means to enhance the display effect of the container surface, for example, a plastic film back printed on the metallic gloss layer surface of the paper provided with a metallic gloss layer on the outer surface is bonded to form a liner paper, and further heat is applied on the plastic film. A paperboard provided with a seal varnish layer has been proposed (see, for example, Patent Document 1 and Patent Document 2).
Japanese Patent Application Laid-Open No. 11-180430. Japanese Patent Application Laid-Open No. 11-100020.

  A configuration using a polyethylene terephthalate film as the outermost layer has also been proposed.

  However, these methods have complicated working processes, increase the number of heat seal varnish application processes, and maintain adhesive strength when one end is overlapped with the other end. There is a problem that it is necessary to apply.

  The present invention has been made in view of the above-described problems relating to paper containers that contain liquid substances such as juice and coffee for a long period of time, and is excellent in surface glossiness and cosmetics. It is an object to provide a paper container having excellent barrier properties.

  The invention of claim 1 of the present invention is a laminate material in which an unstretched polyolefin resin layer is provided on the inner surface side of a paper substrate, and a uniaxially stretched polyolefin resin layer having a glossiness measured by JIS K7105 of 70% or more is provided on the outer surface side. It is a paper container produced as a trunk member.

  Thus, according to the invention described in claim 1, the laminated material in which the unstretched polyolefin resin layer is provided on the inner surface side of the paper base material and the uniaxially stretched polyolefin resin layer having a glossiness of 70% or more is provided on the outer surface side. Since it is produced as a member, the outer surface of the body member has a high gloss, so that it can be printed and looks beautiful, and a paper container rich in beauty can be obtained.

The invention according to claim 2 is the invention according to claim 1, wherein when the one side end edge of the body member is overlapped with the other side end edge and formed into a cylindrical shape, the body member is positioned inside the overlap portion. The side edge that folds the resin extending portion including at least the unstretched polyolefin resin layer extending from the paper base material to the uniaxially stretched polyolefin resin layer surface side including the paper base material, and the folded portion overlaps the paper base material. It is thermally bonded to the uniaxially stretched polyolefin resin layer surface and thermally bonded to the unstretched polyolefin resin layer located on the inner surface side of the other side edge, so that one end edge and the other end edge of the body member are enveloped together. It is a paper container characterized by being stuck.

  Thus, according to the second aspect of the present invention, when one side end edge of the body member is overlapped with the other side end edge and formed into a cylindrical shape, the side end located inside the overlapping portion. The rim is folded back from the paper base to a resin extending portion including at least an unstretched polyolefin resin layer toward the uniaxially stretched polyolefin resin layer side including the paper base, and the folded portion overlaps the paper base. It is thermally bonded to the resin layer surface and thermally bonded to the unstretched polyolefin resin layer located on the inner surface side of the other side edge, and the one end edge and the other end edge of the body member are enveloped together. Therefore, in the overlapped portion, one side edge and the other side edge are bonded to the same unstretched polyolefin resin layer, enabling easy thermal bonding and strong thermal adhesion. Will have

  Furthermore, as a paper end face protection means, a skive hemming means for scraping the end face of the paper is not used, so there is no risk of paper dust being generated, and the paper end face is covered with a polyolefin resin film. It is possible to make a paper container that can be stored for a long period of time without permeating from the end face of the paper.

  A third aspect of the present invention is the paper container according to the first or second aspect, wherein the polyolefin resin located on the inner surface side and the outer surface side is a polyethylene resin.

  Thus, according to the third aspect of the invention, since the polyolefin resin located on the inner surface side and the outer surface side is both a polyethylene resin, the one side edge and the other side edge are easily heated. Bonding is possible, and the thermal adhesive force becomes strong.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein a barrier layer is provided between the paper substrate and the unstretched polyolefin resin layer. It is a paper container.

  Thus, according to the invention described in claim 4, since the barrier layer is provided between the paper substrate and the unstretched polyolefin resin layer, the molded paper container is a paper container having excellent barrier properties. be able to.

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein a metallic luster imparting layer is provided between the paper substrate and the uniaxially stretched polyolefin resin layer. It is a paper container.

  Thus, according to the invention described in claim 5, since a metallic luster imparting layer, more specifically, an aluminum foil or an aluminum vapor deposition film is provided between the paper substrate and the uniaxially stretched polyolefin resin layer, The molded paper container has a metallic luster and is a beautiful paper container. The invention of claim 6 is the paper container according to any one of claims 1 to 5, wherein the paper container is a paper cup.

Thus, in the paper container of the present invention, the outermost layer is provided with a thermoplastic uniaxially stretched polyolefin resin layer having a glossiness of 70% or more, and the uniaxially stretched polyolefin resin layer is provided with a printing layer on the side in contact with the paper layer. Since it is configured, it is possible to form a printed layer having high gloss and excellent color image reproducibility.
In addition, in the overlapped portion where one side edge and the other side edge are overlapped, it becomes thermal bonding between the same unstretched polyolefin resin layers, so that thermal bonding can be easily and firmly performed. Therefore, it is not necessary to use an adhesion assistant as when a polyethylene terephthalate film is used.

The present invention will be described in detail below based on one embodiment.
The paper container (1) of the present invention has, for example, an unstretched polyolefin resin layer (12) on the inner surface side of the paper base (11) and a uniaxially stretched polyolefin resin layer (12) on the outer surface side, as shown in FIGS. 13) is produced using a laminated material (10) provided with a body member, and when one side edge of the body member (2) is overlapped with the other side edge and formed into a cylindrical shape. The side edge (2a) located inside the overlapping portion (3) is formed by the unstretched polyolefin resin layer (12) and the uniaxially stretched polyolefin resin layer (13) extending from the paper substrate (11). The resin extending portion (14) is folded back so that the uniaxially stretched polyolefin resin layer surfaces (13) overlap each other, and the folded portion is an unstretched polyolefin resin layer ( 12) Envelope pasted by heat fusion And those are.

  The unstretched polyolefin resin layer (12) provided on the inner surface side of the paper substrate is a layer that becomes the innermost layer of the paper container, and a generally used low density polyethylene resin can be preferably used.

  The uniaxially stretched polyolefin resin layer (13) provided on the outer surface side of the paper substrate is the outermost layer of the paper container, and is a uniaxially stretched high density that has the same transparency and gloss as the polyolefin resin of the innermost layer. A polyethylene resin can be preferably used. The glossiness is measured by HORIBA Gloss Checker IG-330 manufactured by HORIBA, Ltd. (reflection angle 60 °) according to the optical property test method of JIS K7105 plastic.

  The print layer (15) is preferably provided on the side of the uniaxially stretched polyolefin resin layer (13) that contacts the paper substrate. By providing the printing layer (15) on the inner surface side of the uniaxially stretched polyolefin resin layer (13) by, for example, a gravure printing method, the printing layer (15) excellent in cosmetics and friction resistance can be obtained.

FIG. 3 is a cross-sectional explanatory view of another embodiment of the laminated material used in the paper container of the present invention. In FIG. 3, 16 is a barrier layer and 17 is a metallic luster imparting layer.
That is, it can also be set as the structure which provided the barrier layer (16) between the paper base material (11) and the unstretched polyolefin resin layer (12). As the barrier layer (16), for example, [paper substrate side] polyethylene / aluminum foil / polyethylene terephthalate film [innermost layer unstretched polyolefin resin side], [paper substrate side] polyethylene / silicon oxide-deposited polyethylene terephthalate film [outermost layer] Examples of the composite film include inner layer unstretched polyolefin resin side, [paper substrate side] polyethylene / aluminum oxide-deposited polyethylene terephthalate film [innermost layer unstretched polyolefin resin side]. By providing the barrier layer (16), the barrier property of the paper container is further improved.

  Moreover, it can also be set as the structure which provided the metallic luster provision layer (17) between the paper base material (11) and the uniaxially stretched polyolefin resin layer (13). As the metallic luster imparting layer (17), a plastic film provided with a metal vapor-deposited thin film layer such as an aluminum foil or a polyethylene terephthalate film vapor-deposited with an aluminum oxide thin film can be preferably used. By providing the metallic luster imparting layer (17), the cosmetic properties of the paper container are further enhanced. Whether the barrier layer (16) or the metallic luster imparting layer (17) is provided can be determined in consideration of the type of contents to be accommodated, the distribution period, and the like. Naturally, by providing both the barrier layer (16) and the metallic luster imparting layer (17), a paper container having both barrier properties and metallic luster can be produced.

Next, as an example of how to make a body member with a resin extending portion, two methods will be described by taking the case of a cup-shaped container.
First, in the first method, a plurality of fan-shaped body member blanks (2) are arranged and printed on a roll-shaped uniaxially stretched polyolefin film (13) by using a gravure printing method. In addition, the printing layer (15) is provided simultaneously in the required part of the trunk | drum member blank (2).
A roll-shaped paper base material (11) is bonded to the surface of the roll-shaped uniaxially stretched polyolefin film (13) on which the printed layer (15) is applied, and at one edge of the body member blank (2), The outer part including the edge was perforated as a long window (4) to form a composite sheet (see FIGS. 4A and 4B).

  Then, a low-density polyethylene resin to be an unstretched polyolefin resin layer (12) was laminated on the barrier film, which was a separately prepared barrier layer (16), by a melt extrusion method to obtain a composite film. The barrier layer (16) surface of the composite film and the paper base (11) surface of the roll-shaped composite sheet in which the long window (4) is formed are opposed to each other through low-density polyethylene (18). The laminated material (10) for the trunk member was bonded by a sandwich lamination method (see FIGS. 5A and 5B).

  An unnecessary portion (5) of the body member blank (2) on the side where a long window portion including a resin extending portion (14) provided to extend outward is formed from the roll-shaped laminated material (10). ) Are continuously cut (see FIGS. 6A and 6B).

  Finally, a plurality of printed fan-shaped body member blanks are punched out of the laminated material from which the unnecessary portion (5) on one side is cut off, and a resin extending portion (14) is formed on one edge. A blank (2) can be produced. FIG. 7 shows the state of the edge of the body member blank obtained by folding back the extended resin portion produced by this method.

Next, the second method will be described.
A plurality of fan-shaped drum member blanks (2) are arranged and printed on a roll-shaped paper base (11), and one outer edge of the drum member blank is extended to include the outer edge. Punched and drilled as window (4).

  A uniaxially stretched polyolefin film (13) provided with a printing layer (15) such as a pattern by a gravure printing method and a roll-shaped paper base material (11) in which the long window (4) is formed. The printed layer (15) was placed inside and bonded together by a sandwich lamination method via a low density polyethylene resin (19) to obtain a second composite sheet.

  Separately, a low-density polyethylene resin layer to be an unstretched polyolefin resin layer (12) is laminated on the barrier film as the barrier layer (16) by a melt extrusion method to produce a second composite film, and the barrier film of the second composite film (16) The surface and the paper substrate (11) surface of the second composite sheet are opposed to each other and bonded together by a sandwich lamination method through a low-density polyethylene resin (20) to obtain a laminated material (10) for a trunk member. . Since the following is the same as the first method, description thereof is omitted. FIG. 8 shows the state of the edge of the body member blank obtained by folding back the resin extension produced by this method.

Next, an example of a method in which the resin extending portion (14) of the body member blank (2) having the resin extending portion (14) formed on one end edge in this way is folded and adhered to the end surface of the paper substrate. This will be described with reference to FIGS.

  On the side to be the outer surface side of the paper base material (11) when the resin extending portion (14) extended by a predetermined width from the paper base material (11) of the trunk member blank (2) is formed into a paper cup. The first member (D1) having a pressing protrusion (D11) formed in a comb shape is moved vertically from the top to the bottom in the vertical direction, and is bent and temporarily folded at an angle of about 90 ° (see FIG. 9 and FIG. 9). (Refer to Drawing 10 (a) and (b)).

  Next, the second member (D2) having the pressing protrusion (D21) formed in the shape of a comb is put on the gap (D12) between the pressing protrusion (D11) and the pressing protrusion (D11) of the first member. Then, it is moved horizontally from the outside direction of the body member blank to the inside direction, the resin extending portion (14) is pushed and bent by approximately 90 °, and temporarily folded so that the vicinity of the tip overlaps the paper substrate outside direction of the body member blank. (See FIG. 9 and FIG. 10 (c)).

  Finally, the third member (D3) having a pressing protrusion (D31) disposed on the lower side of the first member and having a comb-like shape is vertically pressed and pressure-bonded upward, and the resin extended portion is turned back. The vicinity of the tip of (14) is temporarily bonded to the outer surface of the paper base of the body member blank (see FIGS. 9 and 10 (d)). In addition, if the pressing protrusion (D31) of the third member (D3) is heated to an appropriate temperature, the adhesiveness of the resin extending portion is improved, which is more effective.

  An example of a molding method for molding a cup-shaped paper container using the body member blank (2) created by such a method will be described (see FIG. 11).

  The side edge (2a) of the body member blank that has folded the resin extended portion (14) and covered the paper end surface is set to the inner surface side, and is overlapped with the other side edge (2b). 3) is formed to produce a cylindrical body member (2) that tapers downward.

  A substantially circular bottom member (6) with a peripheral edge portion (6a) raised downward is fitted into the lower inner surface of the body member, the inner surface of the peripheral edge portion is joined, and then the peripheral edge portion of the bottom member is covered. The lower edge portion (7) of the base member is bent inward to form a bent portion (7a), and the bent portion is joined to the outer surface of the peripheral portion of the bottom member to form the annular leg portion (8).

  Finally, the upper peripheral edge of the body member is wound outward to form a flange portion (9), thereby obtaining a cup-shaped paper container (1).

  As the shape of the paper container of the present invention, in addition to the paper cup-shaped paper container described above, a rectangular columnar paper container with a gable roof type at the top, a hexahedral paper container with a flat top, or a cylindrical paper container, a rectangular tube Examples thereof include a paper container which is molded by heat sealing, such as a paper container (see FIG. 12).

  Specific examples are described in detail below.

First, a cup base paper having a basis weight of 260 g / m ^{2 as} a paper substrate (11), and a Mitsui Hibron film (glossiness 89%) as a uniaxially stretched high-density polyethylene film having a thickness of 25 μm as a uniaxially stretched polyolefin resin (13). ) (Manufactured by Mitsui Chemicals, Inc.).

  A plurality of fan-shaped body member blanks (2) were arranged and printed on the Mitsui Hybron film (13) by gravure printing. In addition, the printing layer (15), such as a pattern, was simultaneously provided in the required part of the trunk | drum member blank (2).

  A roll base paper (11), which is a roll-shaped paper base material, is bonded to the surface of the roll-shaped Mitsui Hybron film (13) on which the printing layer (15) has been applied, and each body member blank ( 2, 2...), And a composite sheet having an outer portion including the edge as a long window (4) was prepared.

  A composite film was prepared by laminating a low-density polyethylene resin to be an unstretched polyolefin resin layer (12) to a thickness of 60 μm by a melt extrusion method on an aluminum foil having a thickness of 9 μm to be separately prepared as a barrier layer (16). .

  The aluminum foil (16) surface of the composite film and the cup base paper (11) surface of the roll-shaped composite sheet in which the long window (4) is formed are opposed to each other through a low density polyethylene resin (18). The laminated material (10) for trunk | drum members was produced by bonding together by the sandwich lamination method.

  Unnecessary portion (5) of the body member blank (2) on the side where a long window including a resin extending portion (14) provided to extend outward from the finished roll-shaped laminated material (10) is formed (5) ) Were continuously cut off and removed.

  Finally, a plurality of fan-shaped body member blanks having a printed layer (15) are punched out from the laminated material from which unnecessary portions (5) on one side are cut off, and a resin extending portion (14) is formed on one edge. A body member blank (2) of Example 1 was prepared.

First, as in the first method, Mitsui is a uniaxially stretched high-density polyethylene film having a thickness of 20 μm as a uniaxially stretched polyolefin resin (13) using a cup base paper having a basis weight of 260 g / m ^{2 as} a paper substrate (11). Hybron films (glossiness of 89%) (manufactured by Mitsui Chemicals, Inc.) were prepared.

  A plurality of fan-shaped body member blanks (2) are arranged and printed on a roll-shaped cup base paper (11), and one end of the body member blank, including the end edge, is a long window. It was punched and drilled as (4).

  A roll in which a printing layer (15) such as a pattern is provided in a gravure printing method at a necessary position on the back side of the Mitsui Hibron film (13), and the Mitsui Hibron film (13) and a long window (4) are perforated. The cup base paper (11) was bonded by a sandwich lamination method through a low density polyethylene resin with the printed layer (15) on the inside to form a second composite sheet.

  Separately, a low-density polyethylene resin to be an unstretched polyolefin resin layer (12) was laminated on an aluminum foil having a thickness of 9 μm prepared as a barrier layer (16) to a thickness of 60 μm by a melt extrusion method to produce a second composite film. .

  The aluminum foil surface of the second composite film and the cup base paper surface of the second composite sheet are opposed to each other, and the second composite film and the second composite sheet are pasted by a sandwich lamination method through a low density polyethylene resin (20). In addition, a laminated material (10) for the trunk member was obtained. Thereafter, in the same manner as in the first method, the trunk member blank (2) of Example 2 in which the resin extending portion (14) was formed on one end edge from the laminated material (10) for the trunk member was produced. .

According to the above-described method, the cup-shaped paper container (1) was produced from the thus produced body member blanks of Example 1 and Example 2 using a known paper cup molding machine.
The finished paper container was a glossy, beautiful paper container, and had a strong bond at the overlapping portion.

It is sectional explanatory drawing which shows one Example of the laminated material used for the trunk | drum member of the paper container of this invention. The cylinder member produced using the laminated material of FIG. 1 is shape | molded in a cylinder shape, (a) is a cross section which shows one Example of the resin extension part extended from the paper base material of one edge of a cylinder member It is explanatory drawing, (b) is the cross section which shows one Example of the overlapping part of the site | part which turned the resin extension part of (a) outward, overlap | superposed with the other edge, and shape | molded in the cylinder shape It is explanatory drawing. It is sectional explanatory drawing which shows another Example of the laminated material used for the trunk | drum member of the paper container of this invention. An example of the state which provided the long window of the trunk | drum member blank used for manufacture of the cup-shaped paper container which is one Example of this invention is shown, (a) is plane explanatory drawing, (b) is (a). It is AA 'line sectional explanatory drawing. An example of the state which bonded the barrier layer to the trunk | drum member blank used for manufacture of the cup-shaped paper container which is one Example of this invention is shown, (a) is plane explanatory drawing, (b) is (a) It is AA 'line cross-section explanatory drawing of). An example of the state which punches the trunk | drum member blank used for manufacture of the cup-shaped paper container which is one Example of this invention to a defined shape is shown, (a) is plane explanatory drawing, (b) is (a). It is AA 'line sectional explanatory drawing. It is sectional explanatory drawing which shows one Example of the edge of the trunk | drum member blank which turned up the resin extension part used for manufacture of the cup-shaped paper container which is one Example of this invention. It is sectional explanatory drawing which shows another Example of the edge of the trunk | drum member blank which turned up the resin extension part used for manufacture of the cup-shaped paper container which is one Example of this invention. It is explanatory drawing which shows typically one Example of the temporary attachment mechanism which bends and temporarily adheres the resin extension part of the trunk | drum member blank which has a resin extension part to the outer surface side of a paper base material. (A)-(d) is explanatory drawing which shows the process of bending and temporarily adhering the resin extension part to the outer surface side of a paper base material. It is explanatory drawing which shows typically the preparation process of a cup-shaped paper container. It is perspective explanatory drawing which shows the example of a shape of the paper container of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Paper container 2 ... Body member, body member blank 2a ... Side edge located inside 2b ... Side edge located outside 3 ... Overlapping part 4 ... Long window 5 ... Unnecessary part 6 ··· Bottom member 6a · Edge portion 7 ··· Lower end edge portion of body member 7a · Bending portion 8 · · · Ring leg portion 9 · · · Flange portion 10 · · · Laminated material 11 · · · Paper base material 12 · · · Unstretched polyolefin Resin layer 13 ... Uniaxially oriented polyolefin resin layer 14 ... Resin extension 15 ... Print layer 16 ... Barrier layer 17 ... Metal gloss layer 18 ... Low density polyethylene resin 19 ... Low density polyethylene resin 20 ... ...... Low density polyethylene resin

Claims (6)

  A laminate material in which an unstretched polyolefin resin layer is provided on the inner surface side of a paper substrate and a uniaxially stretched polyolefin resin layer having a gloss measured by JIS K7105 on the outer surface side of 70% or more is prepared as a body member. Paper container. When one side edge of the body member is overlapped with the other side edge and formed into a cylindrical shape, the side edge located inside the overlap portion is at least unstretched extending from the paper base material. The resin extending portion including the polyolefin resin layer is folded back to the uniaxially stretched polyolefin resin layer surface side including the paper substrate, and the folded portion is thermally bonded to the uniaxially stretched polyolefin resin layer surface overlapping the paper substrate and the other side. It is thermally bonded to an unstretched polyolefin resin layer located on the inner surface side of the edge,
2. The paper container according to claim 1, wherein one end edge and the other end edge of the body member are envelope-attached to each other.   The paper container according to claim 1 or 2, wherein the polyolefin resin located on the inner surface side and the outer surface side is a polyethylene resin.   The paper container according to any one of claims 1 to 3, wherein a barrier layer is provided between the paper substrate and the unstretched polyolefin resin layer.   The paper container according to any one of claims 1 to 4, wherein a metallic luster imparting layer is provided between the paper base and the uniaxially stretched polyolefin resin layer.   The paper container according to claim 1, wherein the paper container is a paper cup.

Images