JP6988193B2 - Paper carton and its manufacturing method - Google Patents

Description

The present invention relates to a top-open type paper carton suitable for accommodating foods such as confectionery, cosmetics, pharmaceuticals, various small miscellaneous goods, and the like, and a method for producing the same.

After opening the top-open type paper carton, the contents can be visually recognized without changing the orientation of the surface of the carton, and the contents can be taken out and opened relatively easily. It is used as a packaging container for foods such as foods, cosmetics, pharmaceuticals, and various small miscellaneous goods.

As a typical form of a top-open type paper carton, for example, as described in Patent Document 1, the knob portion (opening tab) of the front panel is pulled up to widen the top panel to open the contents. Can be taken out. Such a paper carton is assembled after the blank is sacked between the back surface of the front panel and the front surface of the front inner panel (glue margin panel).

On the other hand, as the packaging container, metallic glossy paper may be used from the viewpoint of producing a sense of quality and luxury. The metallic glossy paper is one in which a metal layer is formed on a paper base material by a metal foil, for example, a metal vapor deposition layer as described in Patent Document 2.
Even a top-open type paper carton may be made of such metallic glossy paper from the viewpoint of decorativeness that gives a luxurious impression or a luxurious impression to the product of the contents.

Japanese Unexamined Patent Publication No. 9-193926 Japanese Unexamined Patent Publication No. 2006-27244

The metal layer on the surface of the metallic glossy paper as described above is inferior in adhesiveness to the printing layer using general ink with the adhesive used for producing a normal paper carton.
For this reason, when assembling a blank for a top-open type paper carton, a strong adhesive that does not peel off on the surface of the metal layer is used to attach the sack between the back surface of the front panel and the metal layer on the front surface of the glue margin panel. There is a need.
However, when a strong adhesive is used, the back surface of the opening tab of the front panel also adheres firmly to the metal layer on the surface of the glue margin panel, and the opening tab cannot be easily pulled up at the time of opening, making it difficult to open and surrounding. The paper may be torn or rolled up and peeled off.

To this end, as described in Patent Document 1, it is conceivable to apply an adhesive except for the opening tab portion. However, in mass production of paper cartons, it is difficult to control the coating position of the adhesive, which leads to a decrease in manufacturing efficiency and a decrease in yield of the paper carton.

Therefore, there is a need for a means capable of mass-producing top-open type paper cartons using metallic glossy paper with high productivity.

The present invention has been made to solve the above technical problems, and is a top-open type paper carton having a decorative property due to metallic luster, easy to open, and excellent in productivity, and a method for manufacturing the same. The purpose is to provide.

The present invention improves productivity by adjusting the adhesiveness of the surface of a glue margin panel to be attached to the back surface of a front panel having an opening tab in a top-open type paper carton having a metal layer on the surface. It is based on the finding that it can be improved and that the paper carton can be easily opened.

That is, the present invention provides the following [1] to [6].
[1] A paper carton having a metal layer on at least a part of the front surface, wherein the front panel, the top panel, the rear panel, the bottom panel, and the adhesive margin panel are continuously provided, and the paper carton is connected to the back surface of the front panel. The surface of the glue margin panel is bonded via an adhesive layer, the front panel has an opening tab at a part of its front end, and two breaks extending from the opening tab toward the top panel. It is a top-open type paper carton having an opening area that is cut open by a line, and at least the glue margin panel has a layer structure in which a metal layer and a printing layer are laminated in order from the bottom on a paper substrate, and the glue margin panel has a layer structure. It has a first region whose outermost surface is a printing layer and a second region whose outermost surface is a metal layer, and the first region includes a portion facing the back surface of an opening tab of a front panel, and the adhesive. The layer is formed in contact with at least a part of the first region and at least a part of the second region on the surface of the glue margin panel, and in the glue margin panel, the paper base material and the metal layer of the glue margin panel are formed. Adhesive strength S1, adhesive strength S2 between the metal layer and the printing layer, adhesive strength S3 between the printing layer and the adhesive layer, adhesive strength S4 between the adhesive layer and the front panel, and adhesion between the metal layer and the adhesive layer. A paper carton characterized in that the adhesive force S3 between the printing layer and the adhesive layer is the weakest among the adhesive forces of the force S5.
[2] The paper carton according to the above [1], wherein the metal layer is a metal vapor deposition film.
[3] The paper carton according to the above [1] or [2], wherein the surface of the print layer contains a cured product of an ultraviolet curable resin.
[4] The glue margin panel has a second region, a first region, and a second region in a direction orthogonal to the direction in which the front panel, top panel, rear panel, bottom panel, and glue margin panel are continuously provided. The paper carton according to any one of [1] to [3] above, wherein the adhesive layer is formed so as to be continuously connected to each other and continuously in contact with the three regions.
[5] In any one of the above [1] to [4], the surface of the second region has a grooving portion in which a plurality of grooves are formed in a portion in contact with the adhesive layer. The paper carton described.

[6] The method for manufacturing a paper carton according to any one of [1] to [5] above, wherein a straight gluer is used to continuously extend from the first region to the second region on the surface of the glue margin panel. A method for manufacturing a paper carton, in which an adhesive is applied to attach the back surface of the front panel to the front surface of the glue margin panel.

According to the present invention, it is possible to provide a top-open type paper carton having a decorative property due to metallic luster, easy to open, and excellent in productivity.
Further, according to the manufacturing method of the present invention, the top-open type paper carton can be suitably mass-produced.

It is a schematic perspective view which shows an example of the paper carton of this invention, (a) shows the unopened state, (b) shows the opened state. It is a developed view seen from the front surface side of the blank of the paper carton of FIG. It is a front view which showed the glue margin panel part in the blank of FIG. 2 in detail. FIG. 1 is a schematic cross-sectional view showing the state of adhesion between the front panel and the glue margin panel after opening the paper carton of FIG. 1 in a layered configuration, where FIG. 1A shows a state of a first region and FIG. 1B shows a state of a second region. Shows.

Hereinafter, the paper carton of the present invention will be described in detail with reference to the drawings. The notation of the numerical range of "AA to BB" in this specification means "AA or more and BB or less".

FIG. 1 shows an example of the paper carton of the present invention. (A) shows the unopened state of the paper carton 1, and (b) shows the opened state. Further, FIG. 2 shows a developed view of the paper carton 1 as viewed from the surface side of the blank.
The paper carton 1 has a metal layer on at least a part of the surface thereof, and has a decorative property due to metallic luster in an unopened state.

The paper carton 1 is a top-open paper carton formed from a single blank as shown in FIG. The front panel 2, the top panel 3, the rear panel 4, the bottom panel 5, and the glue margin panel 10 are connected in series, and are bent at a fold line formed at the boundary between the panels to form a glue margin with the back surface of the front panel 2. The surface of the panel 10 is adhered to the surface of the panel 10 via an adhesive layer. The front panel 2 has an opening tab 2a at a part of the front end thereof, and has an opening region A cut open by two breaking lines x extending from the opening tab 2a toward the top panel.
In FIG. 2, the colored portion shows a panel on the surface of the paper carton 1 exposed in the unopened state.

In the paper carton 1, one side panel 6 of the two side panels is connected to the bottom panel 5, and the other side panel 7 is connected to the top panel 3. Further, the side glue margin panels 21 and 22 to which the side panel 6 is covered and attached are connected to the front panel 2 and the rear panel 4, respectively. Similarly, the side glue margin panels 23 and 24 to which the side panel 7 is covered and attached are also connected to the front panel 2 and the rear panel 4, respectively.
The side panels 6 and 7 are of the insertion type and have insertion portions 6a and 6b, respectively.

The form of the paper carton of the present invention is not limited to that described in the drawings. For example, the end points of the two breaking lines extending from the opening tab are broken lines at the boundary with the top panel. There may be a case where the opening area is only the front panel, or the end point of the break line reaches the rear panel and the opening area extends from the front panel to the rear panel. Further, depending on the contents of the paper carton, the top panel may be tilted so as to face sideways to be opened.
The shape of the paper carton is not limited to a rectangular parallelepiped, for example, a triangular prism in which the rear panel and the bottom panel are integrated, a polygonal prism having a pentagonal column or more composed of a plurality of top panels, and a front panel. It may be a semi-cylindrical column or a semi-cylindrical shape in which the to the rear panel is integrated into a curved surface.
The side panel and the side glue margin panel are not limited to the arrangement and shape of the blank shown in FIG. 3, and it is sufficient that the side surface can be sealed.

[Constituent material (packaging material)]
The paper carton 1 has a decorative property due to metallic luster, and has a metal layer on at least a part of the surface thereof. That is, it is made of a packaging material in which a metal layer is formed on a paper base material. The presence or absence of an intervening layer between the paper base material and the metal layer, and the configuration of the intervening layer are not particularly limited. As the packaging material, for example, a material in which a metal layer is laminated on a paper base material via an adhesive layer or the like is generally used.

(Paper base material)
As the paper base material used in the paper carton 1, paperboard is usually used from the viewpoint of maintaining processability and morphology as a carton. The type of paperboard is not particularly limited, and examples thereof include those usually used as paperboard for paper containers such as white paperboard, yellow paperboard, chip balls, and colored paperboard. Among these, white paperboards such as Manila balls and coated balls are often used.
The thickness of the paper base material is preferably 180 to 660 μm, more preferably 250 to 550 μm or less for the paperboard for paper containers. The basis weight of the paper substrate is preferably 210~550g / m ^2, more preferably from 250~450g / m ^2.

(Metal layer)
The metal layer imparts decorativeness due to metallic luster to the paper carton 1, and can be formed by a metal foil, a metal film, or the like. Examples of the metal species used for the metal layer include aluminum, silver, gold, nickel, copper, chromium, and alloys thereof. Among these, aluminum is preferably used from the viewpoint of workability, cost and the like.
The thickness of the metal layer is appropriately set according to the desired decorativeness within a range that can be processed into the paper carton 1 by cutting or bending the packaging material. Usually, in the case of a metal foil, it is preferably about 5 to 20 μm, and in the case of a metal film, it is preferably about 10 to 200 nm.
The metal layer may be formed on a support of a thermoplastic resin such as polyethylene terephthalate from the viewpoint of preventing breakage during processing and ease of handling of the packaging material constituting the paper carton 1. .. The thickness of the support is preferably about 5 to 20 μm.

The metal film can be formed by a known method, and can be formed as a metal vapor-deposited film on a paper substrate or a support, for example. The method for forming the metal vapor-deposited film may be either a direct method of directly vapor-depositing on a paper substrate or a support, or a transfer method of transferring what is vapor-filmed on a film or the like.

(Adhesive layer)
From the viewpoint of improving the adhesiveness between the paper base material and the metal layer, for example, the paper base material is interposed through an adhesive layer such as a cured product of a polyurethane adhesive containing a polyol and an isocyanate compound as main components. And a metal layer may be attached.
Further, the paper base material and the metal layer may be attached to each other via a thermoplastic resin such as low-density polyethylene by a sandwich laminating method or the like.
The thickness of the adhesive layer may be such that the paper base material and the metal layer or the support have sufficient adhesiveness, and is usually 0.2 to 10.0 μm, preferably 0.5 to 8.0 μm. , More preferably 0.7 to 5.0 μm.

Further, in particular, when the paper base material is a coating layer such as a clay coat layer, it is possible to form an anchor coat layer on the coating layer and form the primer layer on the coating layer. It is effective in improving the adhesiveness between the material and the metal layer. The anchor coat layer can have a known structure, and examples of the constituent material include polyethyleneimine and two-component curable polyurethane.

(Print layer)
The paper carton 1 has a portion other than the metal layer on a part of the surface from the viewpoint of decorativeness, information display of contents, and the like. Further, as will be described later, the outermost surface of the first region 10a of the glue margin panel 10 is at least a printing layer 13 for the purpose of controlling the adhesiveness with the adhesive layer 30. When the print layer is the outermost surface other than the first region 10a, a pattern such as a picture, a character, a figure, a symbol, or a pattern can be expressed by the print layer. The print layer can be formed by, for example, monochromatic or multicolor printing with process colors, or can be formed by spot color printing or the like other than that.
The material of the print layer exposed on the surface of the unopened paper carton 1 and the material of the print layer 13 of the first region 10a of the glue margin panel 10 are different even if they are the same. You may.

The thickness of the print layer is appropriately set according to the desired decorativeness of the paper carton, and is usually 0.2 to 10.0 μm, preferably 0.5 to 8.0 μm, and more preferably 0.7 to 5. It is 0.0 μm.
The formation of the print layer is not particularly limited, and can be performed by applying a known printing method such as flexographic printing, offset printing, inkjet printing, or gravure printing.

As the ink used for forming the print layer, an ink obtained by appropriately mixing a binder resin with a colorant such as a pigment or a dye, an extender pigment, a solvent, a stabilizer, a plasticizer, a catalyst, a curing agent or the like is used.
The binder resin preferably has good adhesiveness to the surface of the metal layer. For example, acrylic resin, styrene resin, polyester resin, polyurethane resin, chlorinated polyolefin resin, vinyl chloride. -Vinyl acetate copolymer resin, polyvinyl butyral resin, alkyd resin, petroleum resin, ketone resin, epoxy resin, melamine resin, fluororesin, silicone resin, fibrous derivative, rubber resin, etc. can be mentioned. .. These may be used alone or in combination of two or more.
Further, the printed layer may contain other additives such as an antioxidant and an ultraviolet absorber as long as the adhesiveness between the metal layer and the printed layer is not hindered.

(Primer layer)
It is preferable to interpose a primer layer between the metal layer and the printing layer from the viewpoint of improving the adhesiveness between the two. For example, the metal layer and the printing layer may be attached via a primer layer made of a cured product such as a vinyl chloride-vinyl acetate copolymer resin or a polyurethane resin.
The thickness of the primer layer may be as long as the metal layer and the printing layer have sufficient adhesiveness, and is usually 0.2 to 10.0 μm, preferably 0.5 to 8.0 μm, and more preferably 0. It is 0.7 to 5.0 μm.

[Glue allowance panel]
FIG. 3 shows the surface of the glue margin panel 10 in detail. The glue margin panel 10 has a first region 10a and a second region 10b. The first region 10a includes a portion facing the back surface of the opening tab 2a of the front panel 2. The first region 10a has a layer structure in which a metal layer and a printing layer are laminated in order from the bottom on a paper base material, and the outermost surface is a printing layer. The second region 10b has a layer structure in which a metal layer is laminated on a paper base material, and the outermost surface is a metal layer.
As described above, at least the glue margin panel 10 of the paper carton 1 has a layer structure in which a metal layer and a printing layer are laminated in order from the bottom on a paper base material. The primer layer described above may be formed between the metal layer and the printing layer.

On the front surface of the glue margin panel 10, an adhesive layer for adhering the back surface of the front panel 2 and the front surface of the glue margin panel 10 is in contact with at least a part of the first region 10a and at least a part of the second region 10b. It is formed like this.

FIG. 4 shows the state of the front panel 2 and the glue margin panel 10 after opening the paper carton 1. (A) shows the first region 10a, and (b) shows the second region 10b in a cross-sectional view of the layer structure. In FIG. 4, the first region 10a and the second region 10b of the glue margin panel 10 are shown as schematic views in which the description of the layers other than the paper base material 11, the metal layer 12, and the printing layer 13 is omitted.
Adhesive strength S1 between the paper base material 11 and the metal layer 12 of the glue margin panel 10, adhesive strength S2 between the metal layer 12 and the printing layer 13, adhesive strength S3 between the printing layer 13 and the adhesive layer 30, and the adhesive layer 30. Of the adhesive forces S4 between the and the front panel 2 and the adhesive force S5 between the metal layer 12 and the adhesive layer 30, the adhesive force S3 between the printed layer 13 and the adhesive layer 30 is the weakest.

Since the adhesive strength between the layers has such a relationship, when the paper carton 1 is opened from the opening tab 2a, the front panel 2 and the glue margin panel 10 that are adhered via the adhesive layer 30 are separated from each other. In the first region 10a, as shown in FIG. 4A, the front panel 2 and the glue margin panel 10 are not destroyed, and the adhesive layer 30 is printed while being adhered to the front panel 2. The layer 13 and the adhesive layer 30 are peeled off. On the other hand, in the second region 10b, as shown in FIG. 4B, the adhesive layer 30 does not peel off from the front panel 2 or the metal layer 12, and the front panel 2 and the glue margin panel 10 do not separate from each other. Is not destroyed and the adhesive state is maintained.
Therefore, the paper carton 1 can easily open the opening region A smoothly, and in the second region 10b, the front panel 2 and the glue margin panel 10 do not peel off, and the paper base material around the opening tab 2a. It can be opened neatly without destroying such things.

On the other hand, for example, when the adhesive layer 30 has high adhesiveness to the printing layer 13 and the adhesive force S3 is not the weakest of the adhesive forces S1 to S5, the paper carton 1 is unopened. In the state, the back surface of the front panel 2 and the first region 10a of the glue margin panel 10 are firmly adhered to each other, making it difficult to open the package. Further, when the cohesive force of the paper base material of the front panel 2 is lower than the cohesive force of the adhesive layer 30, the back surface of the front panel 2 breaks the base material at the time of opening and can be peeled off cleanly. In addition, the portion of the front panel 2 other than the opening region A, which is adhered to the second region 10b of the glue margin panel 10, may also be peeled off due to the end portion near the opening tab 2a being rolled up.

From the viewpoint that when the paper carton 1 is opened from the opening tab 2a, the adhesive layer 30 causes cohesive failure, and peeling marks of the adhesive layer 30, so-called adhesive residue, do not occur on the surface of the printing layer 13. It is preferable that the cohesive force of the adhesive layer 30 is stronger than the adhesive forces S3 and S4. Further, it is more preferable that the cohesive force of the adhesive layer 30 is stronger than the adhesive forces S1, S2 and S5.

The surface of the outermost printed layer 13 of the first region 10a preferably contains a cured product of an ultraviolet curable resin from the viewpoint of controlling the adhesiveness with the adhesive layer 30.
By forming the outermost surface of the first region 10a as a printed matter containing a cured product of an ultraviolet curable resin, the functional groups existing on the surface of the printed matter are reduced, and the surface of the printed matter becomes hard, so that the printed matter is adhered. The adhesive force with the agent layer 30 can be reduced. Therefore, when the paper carton 1 is opened from the opening tab 2a, it is possible to prevent the adhesive residue from being generated on the surface of the first region 10a.

The print layer containing a cured product of such an ultraviolet curable resin may be formed by using an ink containing an ultraviolet curable resin in advance as an ink for decorative purposes. That is, the surface of the print layer constituting the appearance of the paper carton 1 and the outermost print layer 13 of the first region 10a of the glue margin panel 10 is a print layer printed with the same ink containing an ultraviolet curable resin. You may.
As the ultraviolet curable resin, one to which a wax component is added is preferably used from the viewpoint of imparting appropriate peelability to the adhesive layer 30 when the paper carton 1 is opened from the opening tab 2a.

Alternatively, it may be formed as a printing layer whose surface is processed with a coating agent or the like using an ultraviolet curable resin after printing with an ink for decorative purposes. In the surface treatment with such a coating agent, a coating agent containing an ultraviolet curable resin as a main agent and a mold release component as an auxiliary agent is preferable. Examples of the release component include polyethylene wax and reactive silicone. Such a coating agent has a function of repelling the overcoated coating agent and enabling a fine uneven surface treatment when another coating agent is applied onto the coating layer formed by the coating agent. Have. Examples of the coating agent containing such a release component include "US peeling OP varnish" (manufactured by DIC Graphics Co., Ltd.).
Some inks and coating agents containing an ultraviolet curable resin are amine-based, but since these easily corrode the metal layer, non-amine-based inks such as tertiary amines that do not contain amines are used. It is preferable to use it. Examples of the ultraviolet curable resin containing a wax component and not containing a tertiary amine include "Dicure Clear 1225DP2" (manufactured by DIC Graphics Co., Ltd.).

Further, as shown in FIG. 3, the first region 10a and the second region 10b have a front panel 2, a top panel 3, a rear panel 4, and a bottom panel 5 from the viewpoint of ease of opening the opening region A. It is preferable that the second region 10b, the first region 10a, and the second region 10b are connected in this order in a direction orthogonal to the direction in which the glue margin panels 10 are continuously provided.
Further, in the unopened paper carton 1, in order to prevent an excessive gap from being generated between the back surface of the front panel 2 and the glue margin panel 10 and the opening tab 2a from being unintentionally rolled up. It is preferable that the adhesive layer 30 is continuously formed in the second region 10b, the first region 10a, and the second region 10b, which are continuously formed.

Further, the surface of the second region 10b is an adhesive layer from the viewpoint of making it more difficult for the adhesive layer 30 to be peeled off so that the adhesive state with the front panel 2 is maintained even when the paper carton 1 is opened. As shown in FIG. 3, it is preferable to have a grooving portion 10c in which a plurality of grooves are formed in a portion in contact with 30.
By forming the grooving portion 10c, the adhesive to be applied permeates into the groove, and the adhesive force S5 between the metal layer 12 and the adhesive layer 30 can be strengthened, and relatively, relatively The adhesive force S3 between the printed layer 13 and the adhesive layer 30 in the first region 10a can be weakened.

The form of the groove in the grooving portion 10c is not particularly limited as long as sufficient strength of the glue margin panel 10 for maintaining the shape of the paper carton 1 can be secured. For example, it can be provided by forming a plurality of rows of fine parallel line grooves at a fine pitch by processing a sewing machine blade. In the case of such grooving, the length of one groove is preferably 0.5 to 5 mm, more preferably 1 to 3 mm, from the viewpoint of improving the adhesive force and workability. The distance between the grooves in the length direction is preferably 0.5 to 5 mm, more preferably 1 to 3 mm. The rows of parallel grooves are preferably 2 to 15 rows, more preferably 3 to 10 rows, and the spacing between the rows is preferably 0.2 to 2 mm, more preferably 0. It is 5 to 1.5 mm.
The groove of the grooving portion 10c may or may not penetrate the glue margin panel 10, but the adhesive used for forming the adhesive layer 30 is the back side of the glue margin panel 10, that is, From the viewpoint of preventing penetration into the inside of the paper carton 1, it is preferable that the paper carton 1 is formed so as not to penetrate.

[Adhesive layer]
The adhesive layer 30 does not easily peel off between the surface of the metal layer and the paper base material during the box-making process of the paper carton 1 or the transportation of the paper carton 1 filled with the contents. It is preferably formed of a material that provides adhesive strength.
The adhesive used for forming such an adhesive layer varies depending on the type of paper base material used, the type of the metal layer, and the like, but is, for example, a material that can obtain a sufficient adhesive force with respect to the metal layer. Examples thereof include vinyl acetate-acrylic copolymer resin emulsion-based adhesives.
By using such an adhesive, the adhesive force S3 between the outermost printed layer 13 and the adhesive layer 30 of the first region 10a of the glue margin panel 10 can be weakened.
When a vinyl acetate-acrylic copolymer resin emulsion-based adhesive is used, the cationic emulsion adhesive can have a stronger adhesive force S5 between the metal layer 12 and the adhesive layer 30. However, considering the ease of peeling in the first region 10a, that is, the ease of opening in the opening region A, it is preferable to use an adhesive of a nonionic emulsion. Examples of the vinyl acetate-acrylic copolymer resin emulsion-based adhesive for nonionic emulsions include "AV-550" (manufactured by Niei Kako Co., Ltd.).
The thickness of the adhesive layer 30 varies depending on the type of adhesive and the like, but is preferably 0.2 to 15.0 μm from the viewpoint of ensuring sufficient adhesive strength between the surface of the metal layer and the paper substrate. Is 0.5 to 12.0 μm, more preferably 1.0 to 10.0 μm.

[Production method]
The method for producing the paper carton 1 is not particularly limited, and a known box-making method can be applied.
From the viewpoint of productivity, in the process of attaching the paper carton 1, for example, the punched blanks as shown in FIG. 2 are conveyed one by one, an adhesive is applied to a predetermined position, and the paper carton 1 is folded by a folding line and crimped. It is preferable to carry out a series of steps of so-called sack pasting machine (gluer) continuously and mechanically.

Further, from the viewpoint of improving productivity, in the so-called body pasting process in which the back surface of the front panel 2 and the front surface of the glue margin panel 10 are bonded with a gluer, the surface of the glue margin panel 10 is bonded with a straight gluer. It is preferable to continuously apply the adhesive from the first region 10a to the second region 10b. Specifically, it is preferable to continuously apply the adhesive in the direction along the line g in FIG. 4 so as to cross the second region 10b, the first region 10a, and the second region 10b in order.
According to the paper carton 1 of the present invention, even when it is desired to make a difference in the adhesiveness to the glue margin panel 10 between the opening tab 2a of the front panel 2 and the portion other than the opening area A, control of the adhesive application location, etc. Therefore, the same adhesive can be used for continuous application regardless of the region of the surface of the glue margin panel. Therefore, the efficiency of the sticking process can be improved, and the productivity of the paper carton can be improved.

A plurality of sheets of the pasted blank are usually folded in a plane and transported to the content filling process, and the content is filled from one side surface side, and the side panels 6 and 7 and the side surface are filled. Fold the glue margin panels 21 to 24 and seal them with a hot melt adhesive or the like. By making a box in this way, the paper carton 1 can be finished in the state shown in FIG.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

(Example 1)
First, the packaging material used for producing the paper carton 1 was produced using the commercially available aluminum-deposited paper shown below.
<Aluminum-deposited paper>
On the surface of coated cardboard with a thickness of 380 μm, an adhesive layer with a thickness of 3 μm formed by a polyurethane adhesive and a metal layer having an aluminum vapor film with a thickness of 100 nm formed on a support of a polyethylene terephthalate film with a thickness of 12 μm are formed. They are stacked in order from the bottom.

On the metal layer of the aluminum-deposited paper, a predetermined position of a part of the metal layer surface of the blank front panel 2, top panel 3, rear panel 4, bottom panel 5, and side panels 6 and 7 shown in FIG. In addition, a primer layer having a thickness of 3 μm was laminated using a vinyl chloride-vinyl acetate copolymer resin at a position of the first region 10a (see FIG. 3) of the glue margin panel 10. Then, a printing layer having a thickness of 2 μm was laminated on the primer layer by flexographic printing using an ultraviolet curable acrylic resin ink containing a pigment (“Dicure Clear 1225DP2”, manufactured by DIC Graphics Co., Ltd.). As a result, a paper base material (coated cardboard), an adhesive layer (a cured product of a polyurethane adhesive), a support (polyethylene terephthalate film), a metal layer (aluminum vapor deposition film), and a primer layer (partly; vinyl chloride-acetic acid). A packaging material formed by laminating a cured body of a vinyl copolymer resin) and a printing layer (partly; an ultraviolet curable acrylic resin ink containing a pigment) in order from the bottom was obtained.

A blank was punched out of this packaging material. During the punching process, a fold line between each panel, a break line A, and a groove cutting portion 10c as shown in FIG. 3 were also formed. The length of one groove in the grooving portion 10c was 2 mm, the distance between the grooves in the length direction was 2 mm, the rows of parallel grooves were 8 rows, and the distance between the rows was 0.7 mm.
Adhesive (vinyl acetate-acrylic copolymer resin nonionic emulsion: "AV-550", Niei) on the glue margin panel 10 with a straight gluer from end to end along the line g shown in FIG. (Made by Kako Co., Ltd.) is applied, the front panel 2 and the glue margin panel 10 are crimped, and the fold line between the front panel 2 and the top panel 3 and the fold line between the rear panel 4 and the bottom panel 5 are used. A blank adhered by the adhesive layer 30 having a thickness of 5 μm, which was folded in a flat shape, was obtained.
Then, the side panels 6 and 7 and the side glue margin panels 21 to 24 are folded and sealed with a hot melt adhesive to prepare a paper carton 1 having a length of 5 cm, a width of 15 cm, and a height of 4 cm as shown in FIG. did.

(Example 2)
In Example 1, an ultraviolet curable coating agent (“US peeling OP varnish”, manufactured by DIC Graphics Co., Ltd.) was applied to the surface of the print layer of the first region 10a of the glue margin panel 10 so as to have a thickness of 1 μm. The coating material was applied, irradiated with ultraviolet rays, and the surface of the print layer was processed. Other than that, a packaging material was prepared in the same manner as in Example 1.
Using this packaging material, a paper carton 1 was produced in the same manner as in Example 1.

(Comparative Example 1)
In Example 1, a vinyl acetate-acrylic copolymer resin cationic emulsion (“AV-650Y4L”, manufactured by Niei Kako Co., Ltd.), which is a cationic resin, is used as the adhesive for forming the adhesive layer 30, and other than that. Made a paper carton 1 in the same manner as in Example 1.

[Opening evaluation]
For each paper carton produced in the above Examples and Comparative Examples, the ease of opening when the opening area A of the front panel 2 is opened from the opening tab 2a, and the back surface of the front panel 2 and the front surface of the glue margin panel 10. The appearance was visually observed and evaluated.

As a result, in Examples 1 and 2, in the unopened state, the back surface of the front panel 2 and the first region 10a of the glue margin panel 10 were adhered to each other, but it was easy to open. At the time of opening, the front panel 2 and the glue margin panel 10 could be peeled off cleanly without being destroyed and without leaving glue residue in the first region 10a of the glue margin panel 10. Further, after opening, it was confirmed that the back surface of the front panel 2 and the second region 10b were not separated from each other, and the adhered state was maintained. As shown in FIG. 4, this is an adhesive force S1 between the paper base material 11 and the metal layer 12 of the glue margin panel 10, an adhesive force S2 between the metal layer 12 and the printing layer 13, and the printing layer 13 and the adhesive layer 30. Of the adhesive strength S3, the adhesive strength S4 between the adhesive layer 30 and the front panel 2, and the adhesive strength S5 between the metal layer 12 and the adhesive layer 30, the printed layer 13 and the adhesive layer 30 It can be said that this is because the adhesive strength S3 of was the weakest.

On the other hand, in Comparative Example 1, in the unopened state, the back surface of the front panel 2 and the first region 10a of the glue margin panel 10 were firmly adhered to each other, and it was difficult to open the package. At the time of opening, the back surface of the front panel 2 was damaged and could not be peeled off cleanly. Further, the portion of the front panel 2 other than the opening region A, which is adhered to the second region 10b of the glue margin panel 10, was also peeled off because the end portion in the vicinity of the opening tab 2a was rolled up. This is because the adhesive used for forming the adhesive layer 30 in Comparative Example 1 has higher adhesiveness to the printing layer 13 than the adhesive used for forming the adhesive layer 30 in Example 1, and the adhesive force S3. However, it cannot be said that it is the weakest of the adhesive forces of S1 to S5, and the cohesive force of the paper substrate of the front panel 2 is lower than the cohesive force of the adhesive layer 30.

1 Paper carton 2 Front panel 2a Opening tab 3 Top panel 4 Rear panel 5 Bottom panel 6, 7 Side panels 6a, 7a Insertion part 10 Glue allowance panel 10a 1st area 10b 2nd area 10c Grooving part 11 Paper base material 12 Metal layer 13 Print layer 21, 22, 23, 24 Side glue margin panel 30 Adhesive layer

Claims (5)

A paper carton with a metal layer on at least part of the surface,
In the paper carton, a front panel, a top panel, a rear panel, a bottom panel, and a glue margin panel are continuously provided, and the back surface of the front panel and the front surface of the glue margin panel are bonded via an adhesive layer to form a front surface. A top open paper carton in which the panel has an opening tab at a portion of its front edge and has an opening area cut open by two breaking lines extending from the opening tab toward the top panel.
At least the glue margin panel has a layer structure in which a metal layer and a printing layer are laminated in order from the bottom on a paper base material.
The glue margin panel has a first region whose outermost surface is a print layer and a second region whose outermost surface is a metal layer, and the first region is a portion facing the back surface of the opening tab of the front panel. Including
The adhesive layer is formed in contact with at least a part of the first region and at least a part of the second region on the surface of the glue margin panel.
The surface of the printing layer contains a cured product of an ultraviolet curable resin, and the surface thereof contains a cured product.
In the glue margin panel, the adhesive strength S1 between the paper base material and the metal layer of the glue margin panel, the adhesive strength S2 between the metal layer and the printing layer, the adhesive strength S3 between the printing layer and the adhesive layer, and the adhesive layer and the front surface. A paper carton characterized in that the adhesive force S3 between the printing layer and the adhesive layer is the weakest among the adhesive forces S4 for the panel and the adhesive force S5 for the metal layer and the adhesive layer. The paper carton according to claim 1, wherein the metal layer is a metal vapor deposition film. In the glue margin panel, the second region, the first region, and the second region are sequentially connected in a direction orthogonal to the direction in which the front panel, the top panel, the rear panel, the bottom panel, and the glue margin panel are connected in order. The paper carton according to claim 1 or 2 , wherein the adhesive layer is formed so as to be in contact with the three regions in succession. The paper carton according to any one of claims 1 to 3 , wherein the surface of the second region has a grooving portion in which a plurality of grooves are formed in a portion in contact with the adhesive layer. The method for manufacturing a paper carton according to any one of claims 1 to 4.
Manufacture of a paper carton in which an adhesive is continuously applied from the first region to the second region of the surface of the glue margin panel with a straight gluer to bond the back surface of the front panel and the front surface of the glue margin panel. Method.

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