JP2014040250A - Mouth structure of paper container for liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mouth structure of a paper container for liquid in which, when heat-sealing a tab to the mouth where an end of a paper of the mouth is covered with a thermoplastic resin, a content is not brought into contact with the end of the paper resulting from that the thermoplastic resin covering the end of the paper is softened and broken by a temperature of the heat-seal.SOLUTION: An opening hole part is provided in a base material layer composed of a paper or a laminate containing a paper, an outer layer and an inner layer are laminated on front and rear surfaces of the base material layer and are fusion-bonded at the opening hole part, the mouth smaller than the opening hole part is opened at a portion fusion-bonded with the outer layer and the inner layer, and the tab for covering and sealing the mouth is formed on the outer layer by heat-sealing. When heat-sealing the tab on the outer layer by a sealant resin of each other, the thermoplastic resin fusion-bonding the outer layer and the inner layer is not softened.

Description

  The present invention relates to a drinking mouth structure for a liquid paper container.

  The liquid paper container is widely used for liquid drinks such as fruit juice drinks, juices, teas, coffees, milk drinks, and alcoholic beverages such as sake and shochu. Such a liquid paper container is provided with a drinking mouth opened in a part of the packaging material constituting the liquid paper container, and is sealed by a heat-sealed tab so as to cover the drinking mouth. There is something that peels off and allows you to drink from the mouth.

  The packaging material constituting this liquid paper container is made of paper as a base material and provided with resin layers on the front and back. At the drinking mouth, the cross section of the opened packaging material is exposed and the paper comes into contact with the contents. It is like that. Therefore, when placed for a long period of time, the liquid of the contents permeates into the paper, the physical properties are lowered, and it is not very preferable in terms of hygiene.

  Therefore, in order to prevent the paper from being exposed in the cross section of the packaging material at the drinking mouth, an opening is provided in the base material layer made of paper or a laminate including paper, and the outer layer and the inner layer are laminated on the front and back of the base material layer. The outer layer and the inner layer are fused at the opening portion, a drinking mouth smaller than the opening portion is opened at the portion where the outer layer and the inner layer are fused, and the end surface of the paper is covered with the outer layer and the inner layer. There are liquid paper containers that do not come into contact with objects (for example, Patent Documents 1 and 2).

  In these liquid paper containers, as shown in FIG. 4 (A), the ends of the paper of the base layer 1 are covered with the outer layer and the inner layer thermoplastic resin 10 in the drinking mouth 5. When trying to heat-seal the tab 6 so as to cover the heat-seal resin layer 61 of the tab 6 and the heat-seal resin layer 32 in the peripheral part of the drinking mouth 5, the thermoplastic resin 10 is softened. In addition, the moisture contained in the paper is vaporized and expands, and as shown in FIG. 4B, the thermoplastic resin 10 is stretched and expanded, and as shown in FIG. There was a case. Therefore, although the end of the paper of the base material layer 1 in the drinking mouth 5 has been covered with much effort, the paper may come into contact with the liquid of the contents.

JP-A-5-246432 JP 2005-186981 A

  The present invention has been made in view of the above circumstances, and when heat-sealing a tab to a drinking mouth in which the end of the drinking paper is covered with a thermoplastic resin, depending on the temperature of the heat seal, It is an object of the present invention to provide a liquid paper container mouthpiece structure in which the thermoplastic resin covering the portion is softened and broken and the contents do not come into contact with the edge of the paper.

In the invention according to claim 1 of the present invention, an opening is provided in a base material layer made of paper or a laminate including paper, and an outer layer and an inner layer are laminated on the front and back of the base material layer, The outer layer and the inner layer are fused, a drinking mouth smaller than the opening is opened at a portion where the outer layer and the inner layer are fused, and a tab for covering and sealing the drinking mouth is provided on the outer layer by heat sealing In addition, when the tub is heat-sealed with the sealant resin of the outer layer, the mouthpiece structure of the liquid paper container is characterized in that the thermoplastic resin to which the outer layer and the inner layer are fused is not softened. .

  The invention according to claim 2 of the present invention is characterized in that the melting point of the thermoplastic resin in which the outer layer and the inner layer are fused is higher than the melting point of the sealant resin in which the outer layer and the tab are heat-sealed. The drinking paper structure of the liquid paper container according to claim 1.

  The invention according to claim 3 of the present invention is characterized in that the thermoplastic resin is polybutylene terephthalate, and the sealant resin is a polypropylene-based easy peel resin. The drinking mouth structure.

  The drinking mouth structure of the liquid paper container of the present invention is such that when the tab is heat-sealed to the drinking mouth where the end of the paper is covered with a thermoplastic resin, the thermoplastic covering the end of the paper by the heat seal temperature. The resin does not soften and break, and the contents do not come into contact with the edge of the paper.

It is explanatory drawing which showed the manufacturing process of the mouth periphery part of an example of the mouth structure of the liquid paper container of this invention in the cross section. (A) It is explanatory drawing of the state which provided the opening part in the base material layer. (B) It is explanatory drawing of the state which provided the outer layer and the inner layer on the front and back of the base material layer. (C) It is explanatory drawing of the state which provided the drinking mouth in the part by which the outer layer and the inner layer were fuse | melted. (D) It is explanatory drawing of the state which sealed the tab so that a drinking mouth might be covered. It is a perspective view of the liquid paper container of the Example of this invention. It is a conceptual diagram explaining manufacture of the liquid paper container of an Example. (A) (B) (C) It is explanatory drawing which showed typically the state which seals a tab at a drinking mouth in an example of the drinking mouth structure of the conventional liquid paper container.

Hereinafter, embodiments for carrying out the present invention will be described.
FIG. 1 is a cross-sectional view illustrating a manufacturing process of a portion around the mouth of an example of the mouth structure of the liquid paper container of the present invention. (A) is explanatory drawing of the state which provided the opening part in the base material layer. (B) is explanatory drawing of the state which provided the outer layer and the inner layer in the front and back of the base material layer. (C) is explanatory drawing of the state which provided the drinking mouth in the part by which the outer layer and the inner layer were fuse | melted. (D) is explanatory drawing of the state which sealed the tab so that a drinking mouth might be covered.

  The drinking mouth structure of the liquid paper container of this example is provided with an opening 2 in a base material layer 1 made of paper or a laminate including paper, as shown in FIG. 1A, as shown in FIG. In addition, the outer layer 3 and the inner layer 4 are laminated on the front and back of the base material layer 1, and the outer layer 3 and the inner layer 4 are fused at the opening 2.

  And the drinking mouth 5 smaller than the opening part 2 is opened in the part by which this outer layer 3 and the inner layer 4 were fuse | melted like FIG.1 (C). As shown in FIG. 1D, the tab 6 is heat-sealed so as to cover the drinking mouth 5 thus provided, and the liquid paper container is sealed.

The base material layer 1 is made of paper or a laminate including paper. Paper used, the size of the liquid packaging cartons, intended use, is appropriately selected depending on the purpose of use, typically, the basis weight of paper 150g / m ² ~300g / m ² is used. As the laminate, a resin layer 11 that can be easily fused to the outer layer 3 and the inner layer 4 may be provided on paper, or a barrier layer may be provided.

The outer layer 3 is provided with a thermoplastic resin layer 31 on the side to be bonded to the base material layer 1. Also,
A heat seal resin layer 32 for heat sealing with the tab 6 is provided on the opposite side. A barrier layer 33 is provided between the thermoplastic resin layer 31 and the heat seal resin layer 32 as necessary.

  The inner layer 4 is provided with a thermoplastic resin layer 41 on the side to be bonded to the base material layer 1. On the opposite side, an inner surface thermoplastic resin layer 42 which is the innermost layer of the container is provided. In addition, a barrier layer 43 is provided between the thermoplastic resin layer 41 and the inner surface thermoplastic resin layer 42 as necessary.

  The tab 6 is provided with a heat seal resin layer 61 for heat sealing with the heat seal resin layer 32 of the outer layer 3. The tab 6 may be provided with a paper layer 62. Further, a barrier layer 63 may be provided between the paper layer 62 and the heat seal resin layer 61 as necessary.

  As barrier layers such as the barrier layer 33, the barrier layer 43, or the barrier layer 63, a laminated body in which a stretched film is laminated on an aluminum foil, an inorganic vapor deposition film, or an inorganic vapor deposition in which an inorganic substance such as alumina or silica is vapor deposited. A film etc. can be used. Further, a barrier resin such as ethylene / vinyl alcohol copolymer or so-called MXD nylon made of metaxylenediamine / adipic acid can be used as the barrier layer.

  The thermoplastic resin layer 31 of the outer layer 3 and the thermoplastic resin layer 41 of the inner layer 4 must be thermoplastic resins that can be thermally fused to each other. Further, the heat seal resin layer 32 of the outer layer 3 and the heat seal resin layer 61 of the tab 6 must be heat sealable with each other. Further, in order to easily open the drinking mouth, it is preferable to use a so-called face-seal type easy peel resin in which the same kind of resin surfaces are opposed to each other and sealed. For example, an easy peel resin made of a mixed resin in which another polyolefin is dispersed in a main polyolefin can be used.

  The heat-sealed thermoplastic resin layer 31 and the thermoplastic resin layer 41 must not be softened when the heat seal resin layer 61 of the tab 6 and the heat seal resin layer 32 of the outer layer 3 are heat sealed.

  Therefore, the melting points of the thermoplastic resins of the thermoplastic resin layer 31 and the thermoplastic resin layer 41 are desirably higher than the melting points of the heat seal resins of the heat seal resin layer 61 and the heat seal resin layer 32.

  When a polyethylene-based easy peel resin is used for the heat seal resin of the heat seal resin layer 61 and the heat seal resin layer 32, the thermoplastic resin of the thermoplastic resin layer 31 and the thermoplastic resin layer 41 has a higher melting point than polyethylene. It is preferable to use polypropylene or the like.

  Further, considering that the liquid paper container is sold at a temperature of 55 to 60 ° C. by a hot bender, a polypropylene easy peel is used for the heat seal resin of the heat seal resin layer 61 and the heat seal resin layer 32. It is preferable to use a resin. In this case, it is preferable to use a thermoplastic resin such as polybutylene terephthalate or polyethylene terephthalate having a melting point higher than that of polypropylene as the thermoplastic resin of the thermoplastic resin layer 31 and the thermoplastic resin layer 41. In addition, polybutylene terephthalate can be preferably used because extrusion lamination is required.

As described above, the thermoplastic resin of the thermoplastic resin layer 31 and the thermoplastic resin layer 41 which are heat-sealed is softened when the heat seal resin layer 61 of the tab 6 and the heat seal resin layer 32 of the outer layer 3 are heat sealed. Since it is not stretched, it will not be ruptured and broken, and the paper will not touch the contents.

  Next, the manufacturing method of the drinking-mouth structure of the liquid paper container of this invention is demonstrated.

  First, the opening 2 is provided in the base material layer 1 by punching. The base material layer 1 may be a single paper, or a barrier layer may be provided on a resin layer that is easily fused or an intermediate layer thereof.

  Next, the outer layer 3 and the inner layer 4 are provided. A film obtained by laminating the heat seal resin layer 32 and the barrier layer 33 of the outer layer 3 is laminated on the base material layer 1 by the sandwich lamination method using the thermoplastic resin layer 31. Further, a film in which the inner surface thermoplastic resin layer 42 and the barrier layer 43 of the inner layer 4 are laminated is laminated on the base material layer 1 by the sandwich lamination method using the thermoplastic resin layer 41. Thereby, in the opening part 2, the thermoplastic resin layer 31 and the thermoplastic resin layer 41 are melt | fused.

  In the part where the outer layer 3 and the inner layer 4 of the hole part 2 are fused, a hole smaller than the hole part 2 is formed by punching to provide a drinking mouth 5. Separately, a tab 6 in which a paper layer 62, a barrier layer 63, and a heat seal resin layer 61 are sequentially laminated is prepared, and the heat seal resin of the tab 6 is provided on the heat seal resin layer 32 surface of the outer layer 3 so as to cover the drinking mouth 5. The layers 61 are opposed to each other and bonded by heat sealing. In this way, the drinking mouth structure of the liquid paper container of the present invention can be manufactured.

Specific examples of the drinking mouth structure of the liquid paper container of the present invention will be described below.
FIG. 2 is a perspective view of the liquid paper container according to the embodiment of the present invention. FIG. 3 is a conceptual diagram illustrating the production of the liquid paper container of the embodiment.

  As shown in FIG. 2, the liquid paper container of the embodiment includes a body member 7, a bottom member 8, a lid member 9, and a tab 6. The body member 7 and the bottom member 8 are made of a laminated film in which polyethylene, paper, polyethylene, silica-deposited polyethylene terephthalate, and polyethylene are laminated in this order from the outer surface side. This laminated film was punched out to produce a trunk member blank 71 and a bottom member blank 81, respectively.

  A lid member 9 provided with a drinking mouth 5 is created. First, the paper of the base material layer 1 was prepared, and the opening 2 was provided by punching. Next, a film in which a polypropylene-based easy peel resin film of the heat seal resin layer 32 was laminated by dry lamination on the alumina-deposited polyethylene terephthalate film of the barrier layer 33 was produced. This film was laminated with the base material layer 1 on the opposite surface of the base material layer 1 by a sandwich lamination method using polybutylene terephthalate of the thermoplastic resin layer 31 to provide an outer layer 3.

  Further, a film was formed by laminating the low-density polyethylene of the inner surface thermoplastic resin layer 42 on the alumina-deposited polyethylene terephthalate film of the barrier layer 43 by extrusion lamination. This film was laminated on the opposite surface of the base material layer 1 by the sandwich lamination method using polybutylene terephthalate of the thermoplastic resin layer 41 to provide the inner layer 4.

As a result, the polybutylene terephthalate of the thermoplastic resin layer 31 of the outer layer 3 and the polybutylene terephthalate of the thermoplastic resin layer 41 of the inner layer 4 are welded at the opening 2. A mouthpiece 5 smaller than the opening 2 is provided by punching at a portion where the outer layer and the inner layer are fused in the opening 2. The laminated film provided with the drinking mouth 5 was punched out to produce a lid member blank 91.

  Next, as shown in FIG. 3, the trunk member blank 71 is rolled into a cylindrical shape, and the left and right ends are overlapped and heat-sealed and bonded together to create a cylindrical trunk member 7. At this time, although not shown in the drawing, the end portion on the container inner side (content side) of the bonded portion of the barrel member 7 was protected by applying a protective tape on the front and back of the barrel member 7 so as to cover the end face of the paper.

  The bottom member blank 81 was prepared by raising the outer peripheral edge portion and providing the standing portion 82. Similarly, the lid member blank 91 was also provided with the lid standing portion 92 by raising the outer peripheral edge portion, thereby creating the lid member 9. The blanking of the bottom member blank 81 and the formation of the upright portion 82, and the punching of the lid member blank 91 and the formation of the lid upright portion 92 may be performed by a series of operations on the molding machine.

  The bottom member 8 provided with the standing portion 82 is inserted and joined to the inner surface of one open end of the cylindrical body member 7 so that the standing portion 82 faces outward, and then the standing portion 82 is joined. One open end portion of the body member 7 was bent inward so as to cover, and joined to the upright portion 82 of the bottom member 8, and the joined portion was heat-pressed and fused to form an annular leg portion 83.

  Similarly, the lid member 9 provided with the lid standing portion 92 is inserted and joined to the inner surface of the other open end of the cylindrical body member 7 so that the lid standing portion 92 faces outward, The other open end of the body member 7 is folded inward so as to cover the lid upright portion 92, joined to the lid upright portion 92 of the lid member 9, and the joined portion is heat-pressed and fused to form a lid annular leg. Part 93 was formed. Thereby, the main body of the liquid paper container is manufactured.

  As the tab 6, an alumina-deposited polyethylene terephthalate film was prepared as the barrier layer 63, and a film in which the polypropylene-based easy peel resin film of the heat seal resin layer 61 was laminated by dry lamination was prepared.

  This film was laminated on the paper of the paper layer 62 by the dry lamination method, and further, a polyethylene terephthalate film was laminated on the opposite surface of the paper of the paper layer 62 by the dry lamination method, and this laminated film was punched to produce a tab 6. .

  The aforementioned liquid container body was filled with the contents from the drinking mouth 5, and the tab 6 was heat sealed so as to cover the drinking mouth 5 to produce a filled liquid paper container.

  Thus, the thermoplastic resin of the outer layer 3 of the lid member 9 is formed by using polypropylene-based easy peel resin for the heat seal resin layer 32 of the lid member 9 provided with the drinking mouth 5 and the heat seal resin layer 61 of the tab 6. Since polybutylene terephthalate having a melting point higher than that of polypropylene is used for the layer 31 and the thermoplastic resin layer 41 of the inner layer 4, when the tab 6 is heat sealed to the outer layer 3 so as to cover the drinking mouth 5, the thermoplastic resin layer The polybutylene terephthalate of 31 and the thermoplastic resin layer 41 was not softened by the heat sealing temperature, and it was not torn and the contents were not in contact with the edge of the paper.

DESCRIPTION OF SYMBOLS 1 ... Base material layer 2 ... Opening part 3 ... Outer layer 31 ... Thermoplastic resin layer 32 ... Heat seal resin layer 33 ... Barrier layer 4 ... Inner layer 41 ... Thermoplastic resin layer 42 ... inner layer thermoplastic resin inner layer 43 ... barrier layer 5 ... drinking mouth 6 ... tab 61 ... heat seal resin layer 62 ... paper layer 63 ... barrier layer 7 ... Body member 71 ... Body member blank 8 ... Bottom member 81 ... Bottom member blank 82 ... Standing part 83 ... Annular leg 9 ... Lid member 91 ...・ Land 92 for lid member ... Lid standing portion 93 ... Loop annular leg

Claims (3)

  An opening is provided in a base material layer made of paper or a laminate including paper, and an outer layer and an inner layer are laminated on the front and back of the base material layer, and the outer layer and the inner layer are fused at the opening, and the outer layer And the inner layer is fused to a portion smaller than the opening, and a tab for covering and sealing the mouth is provided by heat sealing the outer layer, and the tab is attached to the outer layer as a sealant. A drinking mouth structure for a liquid paper container, wherein the thermoplastic resin to which the outer layer and the inner layer are fused is not softened when heat sealing with resin.   2. The liquid paper container according to claim 1, wherein a melting point of the thermoplastic resin in which the outer layer and the inner layer are fused is higher than a melting point of a sealant resin in which the outer layer and the tab are heat-sealed. Drinking mouth structure.   The drinking mouth structure for a liquid paper container according to claim 1 or 2, wherein the thermoplastic resin is polybutylene terephthalate, and the sealant resin is a polypropylene-based easy peel resin.

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