Sealing method

Abstract

To provide a sealing method for a sealing tape which improves work efficiency in the case of delivery.SOLUTION: Provided is a sealing method for sealing mating surfaces of outer flaps at both right and left sides of a packing box using a sealing tape. In the sealing method, the sealing tape includes a surface substrate, a dummy adhesive layer, an intermediate substrate and an adhesive agent layer in this order. The dummy adhesive layer and the intermediate substrate are disposed adjacently, and the sealing tape includes a label part that can be peeled from the intermediate substrate.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a sealing method. [Background technology]

[0002] When a package is delivered to a destination by a courier or the like, a delivery slip label with the address and product information printed on it is affixed to a cardboard box or the like. After the delivery destination affixes a seal of receipt, the delivery company peels off a part of the affixed delivery slip as a receipt and takes it home. For example, a half-cut line is made in the surface base material of the delivery slip label, so that the surface base material can be separated into multiple pieces and peeled off, and one piece of the surface base material separated by the half-cut line is used as the delivery slip, while the other piece of the surface base material is peeled off as the receipt.

[0003] In this way, a pseudo-adhesive layer has been used in a delivery slip label so that receipts and the like can be peeled off. For example, Patent Document 1 discloses a pseudo-adhesive label in which a slip substrate, a pseudo-adhesive layer, an intermediate substrate, an adhesive layer, and a release sheet are laminated in this order so that the pseudo-adhesive layer and the intermediate substrate have pseudo-adhesion. This pseudo-adhesive label is used by peeling off the release sheet and attaching it to an object to be attached by the adhesive layer, and in the label attached to the object to be attached, the slip substrate and the pseudo-adhesive layer can be easily peeled off by hand from the intermediate substrate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Utility Model Registration No. 3178208 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, the opening of a packaging box such as a cardboard box used for home delivery is usually sealed with sealing tape. In this case, the delivery slip label is attached separately from the sealing tape. This causes a problem in that the number of work steps required before delivery is large.

[0006] In addition, after the delivery slip label is peeled off, a part of the delivery slip label still remains on the packaging box. The pseudo-adhesive layer, intermediate substrate, and adhesive layer, which are the constituent materials of the delivery slip label, often cannot be recycled as is when collecting cardboard resources, and it is necessary to separate the delivery slip label from the cardboard. This makes it time-consuming to dispose of the packaging box as resource waste, and reduces the efficiency of recycling work for recycling companies.

[0007] Therefore, one object of the present invention is to provide a sealing method with a sealing tape that improves the efficiency of work during delivery. Another object of the present invention is to provide a sealing method with a sealing tape that can eliminate the need to peel off a separate delivery slip when considering the recycling of packaging boxes. [Means for solving the problem]

[0008] The present invention provides the following:

[0009] (1) A sealing tape having a surface substrate, a pseudo-adhesive layer, an intermediate substrate, and an adhesive layer in this order, the pseudo-adhesive layer and the intermediate substrate being disposed adjacent to each other, and having a label portion that can be peeled off from the intermediate substrate, A sealing method for sealing opposing openings of a packaging box when a pair of outer flaps of the packaging box are closed, along the length of the packaging box.

[0010] (2) The sealing method described in (1), wherein the adhesive constituting the adhesive layer is a remoistenable adhesive containing at least one selected from the group consisting of polyvinyl alcohol-based adhesives, polyvinyl acetate-based adhesives, starch-based adhesives, and cellulose-based adhesives.

[0011] (3) The sealing method according to (1) or (2), wherein the surface substrate is a paper substrate.

[0012] (4) The sealing method described in (3), wherein the paper base material is thermal paper.

[0013] (5) The sealing method according to any one of (1) to (4), wherein the intermediate substrate is a paper substrate.

[0014] (6) A sealing method according to any one of (1) to (5), wherein the label portion is a delivery slip label.

[0015] (7) The sealing method according to any one of (1) to (6), further comprising recording information on a surface substrate of the label portion and using a sealing tape having an adhesive layer to which water has been applied.

[0016] (8) The sealing method according to any one of (1) to (7), wherein the pseudo-adhesive layer is peelable from the intermediate substrate.

[0017] (9) A sealing tape having a surface substrate, a pseudo-adhesive layer, an intermediate substrate and an adhesive layer in this order, the pseudo-adhesive layer and the intermediate substrate being arranged adjacent to each other, and having a label portion that can be peeled off from the intermediate substrate.

[0018] (10) A sealing tape as described in (9), in which the adhesive constituting the adhesive layer is a remoistenable adhesive containing at least one selected from the group consisting of polyvinyl alcohol-based adhesives, polyvinyl acetate-based adhesives, starch-based adhesives and cellulose-based adhesives.

[0019] (11) A method for producing a sealing tape according to (9) or (10), comprising a recording step of recording information on the surface substrate of the label portion, and a water application step of applying water to the adhesive layer. Effect of the Invention

[0020] According to the present invention, it is possible to improve the efficiency of work when delivering packaging boxes. Also, when considering recycling of packaging boxes, the time and effort of peeling off the delivery slip can be saved. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is an explanatory diagram showing a sealing method of a sealing tape according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view of one embodiment of a closure tape. [Diagram 3] FIG. 3 is a cross-sectional view of another embodiment of the sealing tape. [Figure 4] FIG. 4 is a diagram for explaining an example of a method for opening a sealed packaging box. [Diagram 5] FIG. 5 is a diagram showing an example of a roll of sealing tape. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the attached drawings. In the description of the drawings, the same elements are given the same reference numerals, and duplicated explanations will be omitted. In addition, the dimensional ratios of the drawings are exaggerated for the convenience of explanation, and may differ from the actual ratios.

[0023] FIG. 1 is an explanatory diagram showing a sealing method of a sealing tape according to one embodiment of the present invention.

[0024] In FIG. 1, the packaging box 10 is, for example, a cardboard. The packaging box 10 has a pair of opposing length sides 11 and a pair of opposing width sides 12. The packaging box 10 also has a pair of inner flaps (top plate flaps) (not shown) extending from each width side 12, and the inner flaps are folded inward. The packaging box 10 also has a pair of outer flaps (top plate flaps) 13 extending from each length side 11. Note that in FIG. 1, only the outer flap (top plate flap) 13 on the top side is shown, but the packaging box 10 has a pair of outer flaps (bottom plate flaps) and a pair of inner flaps (bottom plate flaps) on the bottom side (not shown). After packaging the contents, the packaging box 10 is closed at the openings (also called seams) 14 of the outer flaps 13. The bottom plate side has the inner flap folded inward like the top plate side, and the seam of the outer flap is sealed with, for example, packing tape. The sealing tape 20 having the label portion 30 is attached to the packaging box from the top of one width surface 12 along the longitudinal direction of the opening 14 to the top of the other width surface 12 so as to seal the entire opening 14 of the outer flap of the packaging box 10. The label portion 30 is, for example, a delivery slip label, and in one embodiment has a receipt. In another embodiment, the delivery slip label has a delivery slip and a receipt. Since the sealing tape 20 is integrated with the label portion 30, it is not necessary to attach a separate label with delivery information such as a delivery slip label, and the efficiency of the delivery work can be improved. In addition, since the sealing tape 20 is integrated with the label portion 30, it is not necessary to manufacture the sealing tape and the delivery slip label separately, which leads to resource reduction. Furthermore, since packaging and slip attachment can be performed simultaneously, it leads to reduction in delivery errors.

[0025] In addition, even if the label 30 or a part of the label 30 is peeled off and the delivery slip, the pseudo adhesive layer outside the label, the intermediate substrate under the label, and the adhesive layer remain on the packaging box, when the user peels the sealing tape off the packaging box to remove the contents, all of these will be peeled off from the packaging box. This saves the user the trouble of peeling off the label separately for sorting at the time of recycling.

[0026] Furthermore, according to the sealing method of this embodiment, the sealing function of the sealing tape is maintained even after the label portion 30 is peeled off, making it possible to prevent unintentional opening.

[0027] FIG. 2 is a cross-sectional view of one embodiment of the sealing tape. The sealing tape 20 is composed of a surface substrate 21, a pseudo adhesive layer 22, an intermediate substrate 23, and an adhesive layer 24. In this case, the surface substrate, the pseudo adhesive layer, the intermediate substrate, and the adhesive layer are formed with a substantially constant thickness from end to end in the surface direction of the sealing tape. Information such as a delivery destination can be printed on the surface substrate 21. The sealing tape 20 is peelable between the pseudo adhesive layer 22 and the intermediate substrate 23. The sealing tape 20 is provided with a half-cut line 25. The half-cut line 25 is formed by cutting the surface substrate 21 and the pseudo adhesive layer 22 so as not to cut (penetrate) the intermediate substrate 23 from the surface side in the stacking direction. The half-cut line 25 may be formed in a perforated shape or a slit shape. The half-cut line 25 allows the label portion 30 to be separated from the area other than the label portion. The label portion is, for example, a delivery slip. A delivery slip is usually peeled off after being stamped or signed by the recipient, and is taken back by the delivery company and used for sorting slips, etc. Therefore, the present invention also provides a sealing tape including a surface substrate, a pseudo-adhesive layer, an intermediate substrate, and an adhesive layer, and having a label portion formed by a half-cut line cut into the surface substrate and the pseudo-adhesive layer 22 so that the half-cut line does not cut the intermediate substrate 23. That is, another aspect of the present invention is a sealing tape having a surface substrate, a pseudo-adhesive layer, an intermediate substrate, and an adhesive layer in this order, the pseudo-adhesive layer and the intermediate substrate are arranged adjacent to each other, and having a label portion that can be peeled off from the intermediate substrate. Such a sealing tape may be in a wound roll shape. When the sealing tape is in a roll shape, the half-cut lines can be inserted at regular intervals.

[0028] In Fig. 2, there are two half-cut lines, but for example, as in Fig. 3, two or more half-cut lines, for example three, may be inserted (Fig. 3, where Fig. 3(A) is a cross-sectional view and Fig. 3(B) is a top view). In Fig. 3, label part 30 is composed of two areas 31 and 32. Area 31 is, for example, a delivery slip, and area 32 is, for example, a receipt.

[0029] In the case of a packaging box made of a paper material to which a sealing tape is applied, such as a cardboard box, if a resin material remains during recycling, the resin material must be peeled off. For example, when the packaging box is opened with a cutter knife or the like, the sealing tape will remain on the packaging box. In a preferred embodiment of the present invention, the sealing tape can be peeled off between the pseudo-adhesive layer, which is made of a resin material, and the intermediate substrate, so that the pseudo-adhesive layer, which needs to be removed during recycling of cardboard, can be easily removed (see FIG. 4(C) below). In addition, in a preferred embodiment of the sealing tape, in which the intermediate substrate is a paper substrate and the remoistening adhesive contains polyvinyl alcohol, polyvinyl acetate, starch, or cellulose, which is also used in paper processing, it is possible to recycle the packaging box together with the cardboard without removing the intermediate substrate or adhesive layer from the packaging box.

[0030] The sealing tape may have other functional layers disposed on the surface or between the layers, so long as the pseudo-adhesive layer and the intermediate substrate are disposed adjacent to each other.

[0031] Fig. 4 is a (longitudinal) cross-sectional view for explaining an example of a method for opening a sealed packaging box. Sealing tape 20 is attached to outer flap 13 of the packaging box so as to seal opening (seam) 14 (Fig. 4(A)). After completing delivery, the delivery company peels off label 30 and takes it home (Fig. 4(B)).

[0032] The sealed packaging box can be opened by peeling off the entire sealing tape from the packaging box. As a result, even if a part of the label part 30 remains on the packaging box, it is peeled off together with the sealing tape, so there is no need to peel off the label part from the packaging box separately.

[0033] Also, the sealing tape may be left attached to the packaging box, and the opening portion of the outer flap may be opened by cutting the sealing tape along the seam with a cutter knife or the like. In such a case, the sealing tape is attached to the packaging box with the label portion 30 (or a part of the label portion 30) peeled off, and the other area 26 of the sealing tape other than the label portion 30 still remains on the packaging box, which is the adherend (FIG. 4(C)). Even in such a case, since the pseudo-adhesive layer 22 and the intermediate substrate 23 can be peeled off from each other, the pseudo-adhesive layer, which is difficult to recycle, can be easily peeled off from the intermediate substrate. Therefore, the efficiency of the recycling work is improved. By peeling off the other area 26, the intermediate substrate 23 and the adhesive layer 24 remain on the packaging box (FIG. 4(D)). By using a paper substrate for the intermediate substrate 23 and a remoistenable adhesive layer containing at least one selected from the group consisting of polyvinyl alcohol-based adhesives, polyvinyl acetate-based adhesives, starch-based adhesives, and cellulose-based adhesives, these materials are recyclable together with the packaging box (e.g., cardboard), which is made of paper, so that the packaging box can be recycled while still attached thereto, improving recyclability. Specifically, polyvinyl alcohol, starch, cellulose, etc. are water-soluble, so they can be dissolved in water and separated from the paper components during the paper recycling process, allowing the paper to be easily recycled.

[0034] 2 to 4, the label part 30 is formed by cutting the half-cut line 25 into the surface base material 21 and the pseudo-adhesive layer 22, but is not limited to such a form, and for example, the half-cut line may be cut only into the surface base material to form the label part 30. In this case, for example, if the pseudo-adhesive layer is formed so as to be peelable between the surface base material and the pseudo-adhesive layer, the label part is formed above the surface base material, and even after the label part is peeled off, the pseudo-adhesive layer remains on the packaging box.

[0035] As described above, the present invention also includes the following aspects.

[0036] A method for recycling a packaging box that has a surface substrate, a pseudo-adhesive layer, an intermediate substrate, and an adhesive layer in this order, the pseudo-adhesive layer and the intermediate substrate being arranged adjacent to each other, and that is sealed using a sealing tape having a label portion where the pseudo-adhesive layer can be peeled off from the intermediate substrate, the method for recycling a packaging box comprising peeling off the pseudo-adhesive layer of the sealing tape from the intermediate substrate.

[0037] Each component constituting the sealing tape will be described below. In this specification, "X to Y" indicating a range means "X or more and Y or less". Furthermore, unless otherwise specified, operations and measurements of physical properties are performed under the conditions of room temperature (20 to 25°C) and relative humidity 45 to 55% RH. Furthermore, in this specification, "(meth)acrylic acid" refers to "acrylic acid or methacrylic acid". In the following description, the label of the present invention may be simply referred to as "label".

[0038] (Surface base material) The surface substrate is not particularly limited, and may be either a resin substrate or a paper substrate, but is preferably a paper substrate since it can be used for slips, etc. The paper substrate is not particularly limited, and examples thereof include fine paper, art paper, craft paper, glassine paper, rayon paper, coated paper, cast coated paper, impregnated paper, synthetic paper, thermal paper, dust-free paper, and recycled paper. The paper substrate may also be a laminate of two or more layers of these. Among these, the paper substrate is preferably thermal paper, craft paper, fine paper, art paper, coated paper, or cast coated paper, and more preferably thermal paper.

[0039] Various information may be recorded on the surface of the surface substrate (the side facing the pseudo adhesive layer), particularly on the surface of the surface substrate of the label portion. When the surface substrate is thermal paper, it has a thermosensitive coloring layer (not shown) on the surface (the side facing the pseudo adhesive layer). This allows recording on the surface of the thermal paper using a thermal printer or the like. Examples of the thermosensitive coloring layer include those containing a leuco dye and a color developer that reacts with the leuco dye. The thermosensitive coloring layer is suitably formed, for example, by applying a coating liquid containing the above-mentioned leuco dye and color developer, as well as a binder, wax, solvent, etc., to the surface of the paper substrate.

[0040] The surface substrate may have a coating layer for printing on the surface.

[0041] The thickness of the surface substrate is not particularly limited, but is preferably 10 μm to 200 μm, more preferably 20 μm to 150 μm, and even more preferably 30 μm to 100 μm. By setting the thickness to such a range, the handling property during application and after peeling is improved.

[0042] The surface substrate is, for example, a substrate for displaying information about the packaging box. For example, when the packaging box is a delivery item and the label part is used as a delivery slip label, the information about the packaging box includes the sender, the destination, the name or name of the delivery company, the address, the telephone number, the contents of the delivery item, and the like.

[0043] The information may be displayed using, for example, characters, symbols, figures, or any combination thereof, and may also be displayed using two-dimensional codes such as bar codes and QR codes (registered trademark).

[0044] (pseudo adhesive layer) The pseudo-adhesive layer preferably contains a thermoplastic resin, and is preferably formed substantially only from a thermoplastic resin. The pseudo-adhesive layer being substantially composed of a thermoplastic resin means that 80% by mass or more (up to 100% by mass) of the total mass of the pseudo-adhesive layer is composed of a thermoplastic resin. The pseudo-adhesive layer preferably contains 85% by mass or more of a thermoplastic resin, more preferably 90% by mass or more, and even more preferably 95% by mass or more of the thermoplastic resin, based on the total mass of the pseudo-adhesive layer.

[0045] Examples of the thermoplastic resin contained in the pseudo-adhesive layer include ethylene-acrylic copolymer resin, styrene resin, acrylic resin, polyester resin, vinyl acetate resin, polyurethane resin, acrylic acid ester copolymer resin, polyethylene, ethylene-vinyl acetate copolymer resin, polyolefin resin such as polypropylene, styrene-butadiene copolymer resin, natural rubber resin, and vinylidene chloride resin. The pseudo-adhesive layer may contain one type of thermoplastic resin or two or more types.

[0046] The pseudo-adhesive layer preferably contains a polyolefin resin. The polyolefin resin is a polymer having at least a structural unit derived from an olefin monomer. The olefin monomer is preferably an olefin having 2 to 8 carbon atoms. Examples of the olefin having 2 to 8 carbon atoms include ethylene, propylene, butylene, isobutylene, and 1-hexene. In one aspect of this embodiment, the olefin monomer is more preferably at least one monomer selected from the group consisting of ethylene, propylene, and butylene, which are olefins having 2 to 4 carbon atoms, and more preferably at least one monomer selected from the group consisting of ethylene and propylene, which are olefins having 2 to 3 carbon atoms. The polyolefin resin may be a polymer using one type of olefin monomer alone, or may be a copolymer using two or more types of olefin monomers in combination.

[0047] Examples of polyolefin resins include polyethylene resins, polypropylene resins (PP), polybutene resins (PB), ethylene-propylene copolymers, olefin elastomers (TPO), the polar group-containing polyolefin resins described below, and olefin terpolymers such as ethylene-propylene-(5-ethylidene-2-norbornene).

[0048] The pseudo-adhesive layer may contain an additive. Examples of additives include antioxidants, lubricants, ultraviolet absorbers, colorants, and antiblocking agents. When the pseudo-adhesive layer contains an additive, the additive may be one type or two or more types. When the pseudo-adhesive layer contains an additive, the content of the additive is preferably 0.0001 parts by mass or more and 20 parts by mass or less, more preferably 0.0005 parts by mass or more and 15 parts by mass or less, and even more preferably 0.001 parts by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the thermoplastic resin.

[0049] The thickness of the pseudo-adhesive layer is not particularly limited, but is, for example, from 1 μm to 50 μm, from 5 μm to 40 μm, from 10 μm to 40 μm, or from 10 μm to 30 μm.

[0050] The pseudo-adhesive layer is peelable between the surface substrate or the intermediate substrate, and preferably, the pseudo-adhesive layer is peelable from the intermediate substrate and is pseudo-adhered to the intermediate substrate. The pseudo-adhesive strength of the pseudo-adhesive layer to the intermediate substrate is preferably 150 mN / 50 mm or more and 2000 mN / 50 mm or less, more preferably 200 mN / 50 mm or more and 1000 mN / 50 mm or less, and even more preferably 250 mN / 50 mm or more and 600 mN / 50 mm or less. When the pseudo-adhesive strength of the pseudo-adhesive layer is equal to or more than the lower limit, peeling at the pseudo-adhesive interface between the pseudo-adhesive layer and the intermediate substrate, and the label can be prevented from floating. When the pseudo-adhesive strength of the pseudo-adhesive layer is equal to or less than the upper limit, the label can be easily peeled from the intermediate substrate. The pseudo-adhesive strength can be measured by the method described below.

[0051] Pseudo adhesion measurement method: A test piece with a width of 50 mm was prepared, and the pseudo-adhesive layer was peeled off at the interface between the pseudo-adhesive layer and the intermediate substrate. The laminate consisting of the surface substrate above the pseudo-adhesive layer and the pseudo-adhesive layer was gripped, and the laminate of the intermediate substrate and the adhesive layer was fixed. The gripped and fixed test piece was peeled off at the pseudo-adhesive interface under the following conditions: peel speed: 300 mm / min, peel angle: 180°. The magnitude of the force (peel force) required for this peeling was measured, and the measured peel force was taken as the pseudo-adhesive force. The unit of pseudo-adhesive force is mN / 50 mm.

[0052] The pseudo-adhesive layer is formed, for example, by a sandwich lamination method in which the above-mentioned thermoplastic resin is melted and applied between the surface substrate and the intermediate substrate, and then laminated. Specifically, the thermoplastic resin is melted and applied to the back side of the surface substrate at an initial temperature equal to or higher than its melting point, and immediately after forming the pseudo-adhesive layer, the laminate of the intermediate substrate / adhesive layer is superposed, and cooled and pressed with a cooling roll, thereby forming a laminated structure of the surface substrate / pseudo-adhesive layer / intermediate substrate / adhesive layer.

[0053] (Intermediate substrate) The intermediate substrate is preferably a paper substrate. By using a paper substrate as the intermediate substrate, even if a label remains on a packaging box, for example, a cardboard box, the packaging box can be recycled as it is, improving recyclability.

[0054] The paper substrate is not particularly limited, and examples thereof include kraft paper, fine paper, glassine paper, coated paper, art paper, cast coated paper, etc. The paper substrate may also be a laminate of two or more layers of these. Among these, the paper substrate is preferably kraft paper, glassine paper, or fine paper, and more preferably glassine paper because it is less likely to be cut by half cutting.

[0055] The thickness of the intermediate substrate is not particularly limited, but is preferably 10 μm or more and 200 μm or less, more preferably 20 μm or more and 150 μm or less, and even more preferably 30 μm or more and 100 μm or less.

[0056] (adhesive layer) The adhesive constituting the adhesive layer 24 is not particularly limited, and examples thereof include thermoplastic elastomer adhesives such as styrene-isoprene-styrene block copolymer (SIS); synthetic rubbers such as isoprene rubber, polybutene rubber, butyl rubber, and acrylic rubber, and rubber-based adhesives such as natural rubber; and urethane resin adhesives such as one-component moisture-curing urethane resin adhesives and two-component reactive urethane resin adhesives. The adhesive also includes pressure-sensitive adhesives (adhesives). The pressure-sensitive adhesive is not particularly limited, and examples of the pressure-sensitive adhesive that can be used include acrylic pressure-sensitive adhesives, rubber pressure-sensitive adhesives, silicone pressure-sensitive adhesives, urethane pressure-sensitive adhesives, polyester pressure-sensitive adhesives, vinyl alkyl ether pressure-sensitive adhesives, polyamide pressure-sensitive adhesives, and fluorine pressure-sensitive adhesives.

[0057] The adhesive is preferably a remoisturized adhesive. The remoisturized adhesive exhibits tackiness when water is applied, and does not have tackiness when water is not applied. As a result, an adhesive layer that is constantly tacky requires a release liner before use, but a remoisturized adhesive layer does not require a release liner, which reduces the environmental impact. Therefore, the sealing tape of one embodiment of the present invention does not include a release liner.

[0058] When the packaging box is made of paper, since it can be recycled together with the packaging box, it is preferable that the adhesive be a remoistenable adhesive containing at least one adhesive selected from the group consisting of polyvinyl alcohol-based adhesives, polyvinyl acetate-based adhesives, starch-based adhesives, and cellulose-based adhesives.

[0059] Examples of polyvinyl alcohol used in polyvinyl alcohol-based adhesives include unmodified polyvinyl alcohol and modified polyvinyl alcohol.

[0060] Examples of modified polyvinyl alcohol include α-olefin modified polyvinyl alcohol, cation modified polyvinyl alcohol, anion modified polyvinyl alcohol, silanol modified polyvinyl alcohol, acetoacetyl modified polyvinyl alcohol, and mercapto modified polyvinyl alcohol.

[0061] The adhesive strength of the adhesive layer depends, for example, on the degree of polymerization of the polyvinyl alcohol constituting the adhesive layer, and the degree of polymerization of the polyvinyl alcohol is preferably 300 or more and 5000 or less, more preferably 350 or more and 4900 or less, and even more preferably 400 or more and 4800 or less.

[0062] This makes it possible to make the solubility of polyvinyl alcohol in water more suitable, allowing the adhesive layer to be formed more suitably and making the adhesive strength when water is applied more excellent.

[0063] In this specification, the "degree of polymerization of polyvinyl alcohol" refers to a value measured by a method based on the "average degree of polymerization" described in JIS K 6726:1994.

[0064] Even if the degree of polymerization of polyvinyl alcohol is within the above range, the adhesiveness of the adhesive layer can be adjusted by adjusting the degree of polymerization.

[0065] For example, when the degree of polymerization of polyvinyl alcohol is a value in a relatively low region within the above range, the polyvinyl alcohol becomes easily soluble in water, and the initial adhesive strength of the adhesive layer, in other words, the adhesive strength when the adhesive layer is wet after it is affixed to a packaging box to develop tackiness, can be improved.

[0066] Furthermore, when the degree of polymerization of polyvinyl alcohol is a value in a relatively high region within the above range, the film strength of the adhesive layer after drying, in other words, the film strength when the adhesive layer is made tacky by adding water to it, attached to a packaging box, and then dried to form a film, is high.

[0067] This can result in better final adhesive strength.

[0068] The degree of polymerization of polyvinyl alcohol can be determined according to the adhesive property that is important in the adhesive layer, for example, the initial adhesive strength after application to a packaging box or the adhesive strength after drying.

[0069] Polyvinyl acetate adhesives are made of polymers containing vinyl acetate as a monomer unit, and examples of constituent materials include polyvinyl acetate and ethylene-vinyl acetate copolymers.

[0070] Examples of starches used in starch-based adhesives include corn starch, wheat flour, sweet potato starch, potato starch, tapioca, etc. Starch also includes modified starch.

[0071] Examples of materials constituting the cellulose-based adhesive include methyl cellulose, hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, carboxymethyl cellulose, and biscellulose.

[0072] The thickness of the adhesive layer is not particularly limited, but is preferably from 1 μm to 50 μm, more preferably from 1 μm to 30 μm, and even more preferably from 1 μm to 20 μm.

[0073] When the adhesive used in the adhesive layer of the sealing tape is a remoisturizing adhesive, water is applied to the adhesive layer to make the adhesive layer develop tackiness, and then the sealing tape is attached to the packaging box by the adhesive layer. The water applied to the adhesive layer is not particularly limited, but for example, tap water, ion-exchanged water, etc. can be used, and liquids containing water can also be used.

[0074] The present invention also provides a method for producing a sealing tape having a surface substrate, a pseudo-adhesive layer, an intermediate substrate, and an adhesive layer in this order, the pseudo-adhesive layer and the intermediate substrate being arranged adjacent to each other, and having a label portion that can be peeled off from the intermediate substrate, the method comprising a printing step of printing on the surface substrate of the label portion, and a water application step of applying water to the adhesive layer.

[0075] One embodiment of a method for manufacturing the sealing tape will now be described.

[0076] (1) Manufacturing of a laminate of a surface substrate / pseudo adhesive layer / intermediate substrate / adhesive layer (manufacturing process of the laminate) A thermoplastic resin is melted at an initial temperature equal to or higher than its melting point and applied to the back side of the surface substrate to form a pseudo-adhesive layer. Immediately after this, a laminate of the intermediate substrate / adhesive layer is superimposed and cooled and pressed with a cooling roll to form a laminate structure of the surface substrate / pseudo-adhesive layer / intermediate substrate / adhesive layer. Furthermore, this laminate structure may be wound into a roll.

[0077] (2) Inserting half-cut wires into the laminate (half-cut process) In this process, the half-cut lines are inserted so as to form the label portion of the sealing tape. The above-mentioned laminated structure is usually long, and when sealing the packaging box, the sealing tape is cut to match the length of the seam of the packaging box. Therefore, taking into consideration the length of the sealing tape used when sealing the packaging box, a plurality of half-cut lines are inserted at regular intervals into the long laminated body. The line 40 in FIG. 5 is a portion to be cut by a tape cutter or the like when sealing the packaging box, taking into consideration the length of the packaging box (i.e., the portion from the end of the rolled sealing tape in FIG. 5 to 40 becomes the sealing tape used to seal the packaging box). Then, taking into consideration the length of the sealing tape when used to seal the packaging box, a plurality of half-cut lines 25 are provided at regular intervals on the rolled sealing tape, and as a result, a plurality of label portions 30 are also provided at regular intervals on the long sealing tape.

[0078] (3) Recording information on the surface substrate of the label (information recording process) Information is recorded, for example, by printing or a thermal printer. Recording on the label portion is performed by recognizing the label portion formed by the half-cut line, and delivery destination information and the like is recorded on each label portion. Therefore, the information recorded on each label portion may be different from one another (the information recorded on each label portion may be variable information).

[0079] (4) Adding water to the adhesive layer (water application process) The method of applying water to the adhesive layer is not particularly limited, and examples thereof include a method using a spray bottle, a brush, a sponge, a sponge roller, etc. A device can be used for applying water in this way. Specifically, a device capable of applying water to the adhesive layer after unwinding a roll-shaped sealing tape can be used, and for example, by placing a brush inside a water tank part in which water is stored, water can be sucked up to the tips of the brush bristles by utilizing capillary action, and the brush with the water attached thereto is brought into contact with the adhesive layer.

[0080] The recording (printing) of information and the application of water to the adhesive layer may be performed in one device or in separate devices. When performed in one device, the device has a recording section that records information on the surface substrate and a water application section that applies water. In the process in which the rolled sealing tape is unwound and transported, the recording section records information, and the water application section sequentially applies water. It is also preferable that the recording (printing) of information and the application of water to the adhesive layer are performed continuously after the rolled sealing tape is unwound.

[0081] Although the sealing method according to the embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the invention. [Explanation of symbols]

[0082] 10 packaging boxes, 11 Length surface, 12 width, 13 Outer flap, 14 Openings (joints), 20 sealing tape, 21 Surface base material, 22 pseudo-adhesive layer, 23 intermediate substrate, 24 Adhesive layer 25 Half cut wire, 30 Label section.

Claims

1. A sealing tape having a surface substrate, a pseudo-adhesive layer, an intermediate substrate, and an adhesive layer in this order, the pseudo-adhesive layer and the intermediate substrate being disposed adjacent to each other, and having a label portion that can be peeled off from the intermediate substrate, A sealing method for sealing opposing openings of a packaging box when a pair of outer flaps of the packaging box are closed, along the length of the packaging box.

2. 2. The sealing method according to claim 1, wherein the adhesive constituting the adhesive layer is a remoistenable adhesive containing at least one selected from the group consisting of polyvinyl alcohol-based adhesives, polyvinyl acetate-based adhesives, starch-based adhesives and cellulose-based adhesives.

3. The sealing method according to claim 1 or 2, wherein the surface substrate is a paper substrate.

4. The sealing method according to claim 3, wherein the paper substrate is a thermal paper.

5. The sealing method according to claim 1 or 2, wherein the intermediate substrate is a paper substrate.

6. The sealing method according to claim 1 or 2, wherein the label portion is a shipping slip label.

7. 3. The sealing method according to claim 1, further comprising the step of recording information on a surface substrate of the label portion and using a sealing tape having an adhesive layer to which water has been applied.

8. The method of claim 1 or 2, wherein the pseudo-adhesive layer is peelable from the intermediate substrate.

9. A sealing tape comprising a surface substrate, a pseudo-adhesive layer, an intermediate substrate and an adhesive layer in this order, the pseudo-adhesive layer and the intermediate substrate being arranged adjacent to each other, and having a label portion that can be peeled off from the intermediate substrate.

10. The sealing tape according to claim 9, wherein the adhesive constituting the adhesive layer is a remoistenable adhesive containing at least one selected from the group consisting of polyvinyl alcohol-based adhesives, polyvinyl acetate-based adhesives, starch-based adhesives and cellulose-based adhesives.

11. 11. The method for producing a sealing tape according to claim 9, further comprising: a recording step of recording information on a surface substrate of the label portion; and a water application step of applying water to the adhesive layer.

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