TWI601673B - Package with pasteboard and production method thereof - Google Patents

Description

Cardboard package and manufacturing method thereof

The present invention relates to a package having a cardboard and a method of manufacturing the same. More specifically, the present invention relates to a package having a cardboard formed using a hot melt adhesive and a method of manufacturing the same.

As a package form, Blister Packaging has been used since. The blister pack is in the form of a package in which a thermoplastic resin sheet is heated to soften it, and a relatively rigid transparent plastic accommodating article is prepared in accordance with the shape of the article, and then the plastic is attached to the printed article name. Or the information on the cardboard. Since it is a transparent package, it has the advantage of visually confirming the contents while packaging the articles. However, Shrink Film Packaging, which is a packaging form that replaces blister packaging, has recently attracted attention from the viewpoint of reduction in the amount of CO ₂ discharged from packaging materials and reduction in waste.

As a manufacturing method of the shrink film package, for example, Patent Document 1 discloses a method of manufacturing a paperboard having a shrink film (a paperboard having a heat shrinkable film) by the following steps: (a) a paperboard supply step, a cardboard One piece is supplied to the conveyor one by one; (b) an adhesive coating step, and the adhesive is applied to the film by the plate roller a surface of the paperboard which is supplied to the conveyor and which is conveyed; and (c) a step of attaching the tubular film, and supplying the heat-shrinkable tubular film to the cardboard coated with the adhesive and adhering to the cardboard on. Further, Patent Document 2 proposes a method of manufacturing a cardboard having a shrink film (a paperboard having a film capable of heat shrinking) which can arbitrarily change the shape of the paperboard.

Patent Document 3 discloses a configuration in which a cardboard having a shrink film which is easy to be positioned and which does not cause wrinkles or corners (edges) after shrinkage is provided to block a portion of the upper end opening portion or the lower end opening portion of the shrink film. The way to set the positioning succeeds. In this document, as a method of fixing a shrink film to a cardboard, a fixing method other than an adhesive, a hot-melt adhesive, a reactive hot-melt adhesive, or an adhesive is mentioned, and it is heat-resistant viewpoint. In other words, "reactive hot melt adhesive" is superior to "hot melt adhesive". Further, the "hot melt adhesive" in the present specification means a non-reactive hot melt adhesive, which is different from the reactive hot melt adhesive.

As an adhesive agent for adhering a shrink film to a paperboard, Patent Document 4 describes an aqueous emulsion type adhesive which is generally used for the production of a paper container and is called a glue, or a heat fusion joint. Ingredients, reactive hot melt adhesives. Further, Patent Document 5 discloses a method of producing a package having a cardboard using a molten reactive hot-melt adhesive.

FIG. 7 is a conceptual diagram showing the subsequent strength with respect to the elapsed time after application of the urethane-based reactive hot-melt adhesive described in Non-Patent Document 1 ( FIG. 3 of the document). The solid line (RHM) in the figure is a urethane-based reactive hot-melt adhesive, and the large-sized dotted line indicates a hot-melt adhesive, and the size is small. Lines indicate reactive adhesives. It is described in the literature that the time until the curing of the reactive hot-melt adhesive is usually within a few seconds to one minute, and it takes 1 day to 3 days to completely cure by moisture. Further, in this document, it is described that a reactive hot-melt adhesive is cured by moisture in the air and has a three-dimensional network structure like a reactive adhesive, and therefore has the advantages of a hot melt adhesive and a reactive adhesive. The advantages.

As in Citation 3, the use of reactive hot melt adhesives excellent in heat resistance, such as reactive hot melt adhesives, has been actively promoted. To date, reactive hot melt adhesives have been actively used. Various studies have been conducted.

Further, although it differs from the technique relating to a package having a cardboard, Patent Document 6 discloses a technique relating to a heat-insulating container for foods, and discloses a foaming hot-melt adhesive for use in a rib. Further, Patent Document 7 discloses a foaming hot melt manufacturing apparatus.

[Prior Art Literature]

[Patent Literature]

[Patent Document 1]: Japanese Patent Laid-Open No. Hei 8-244832

[Patent Document 2]: Japanese Patent Laid-Open No. Hei 11-208715

[Patent Document 3]: Japanese Patent Laid-Open Publication No. 2012-188127

[Patent Document 4]: Japanese Patent Laid-Open Publication No. 2012-166459

[Patent Document 5]: Japanese Patent Laid-Open Publication No. 2012-121590

[Patent Document 6]: Japanese Patent Laid-Open Publication No. 2000-344280

[Patent Document 7]: Japanese Patent Laid-Open No. 09-173917

[Non-patent literature]

[Non-Patent Document 1]: "National Technical Report", Vol. 40, No. 1, February, 1994, page 1

According to the shrink film package, as described above, compared with the blister pack, cost reduction, volume reduction, CO ₂ reduction from the packaging material, and the like can be achieved, and the use thereof has been increasing in recent years. However, in the blister pack, the article is accommodated in the plastic imitation of the shape of the article, and the edge portion of the plastic is bonded to the cardboard by the adhesive, so that the shape of the article at the time of joining does not become a problem, as opposed to Therefore, in the shrink film package, the article and the paperboard are fixed via the adhesive layer and the heat-shrinkable film (heat-shrinkable shrink film), and therefore the shape of the article has a large influence on the bonding. In other words, in the point that the object as the article to be packaged has a large number of objects, the blister package is superior to the shrink film package, and a technique for expanding the object of the applicable article in the shrink film package is required.

The present invention has been made in view of the above circumstances, and an object of the invention is to provide a package having a cardboard and a method for producing the same, which are capable of expanding an object of an article to be packaged in a shrink film package.

As a result of repeated efforts by the inventors of the present invention, it has been found that the subject matter of the present invention can be solved in the following aspects, and the present invention has been completed. That is, the package with paperboard of the present invention comprises paperboard, an article packaged by the heat-shrinkable film, and an adhesive layer which bonds the heat-shrinkable film to the paperboard, and the adhesive layer contains heat of foaming The adhesive layer is provided, and the foamed hot-melt adhesive layer contains bubbles in the hot-melt adhesive which can be reversibly remelted and solidified by heat.

The reactive hot-melt adhesive agent strongly recommended in Citation 3 is excellent in terms of heat resistance. However, immediately after the shrink film is bonded to the paperboard, the cohesive force as the adhesive layer is small, and the cohesive force is accompanied by the progress of the hardening reaction. Slowly grow bigger. For example, in the case of a moisture-curing type reactive hot-melt adhesive, it takes about 1 to 3 days for curing (see Non-Patent Document 1). Therefore, immediately after the bonding, there is a flaw in the attachment position, and in order to prevent the positional shift from occurring before the hardening is completed, it is necessary to stand still in a state where load or friction is avoided.

On the other hand, according to the package with cardboard of the present invention, since the foamed hot-melt adhesive layer is used as the adhesive layer, it is rapidly cured after being attached. Therefore, the hardening time is not required, and since the cohesive force as the adhesive layer from the hardening is sufficiently large, no special treatment is required. Further, according to the package with cardboard of the present invention, since the foamed hot-melt adhesive layer is used as the adhesive layer, the elasticity of the adhesive layer can be improved and the lift can be improved as compared with the unfoamed adhesive layer. Follow-up of the agent layer and the object to be joined (heat-shrinkable film or paperboard) and articles. Since the adhesive layer is elastic, even if it is a hard adhesive agent excellent in heat resistance, it is possible to improve the elasticity by foaming, and it is difficult to break at a low temperature. Further, by increasing the followability, the contact area with the joined portion can be increased and the adhesion can be improved even when the surface of the article has minute irregularities or curved surfaces, for example. Therefore, it is possible to provide a package with cardboard which can enlarge the object of the article to be packaged.

In a preferred embodiment of the package with paperboard of the present invention, the hot melt adhesive has a melt viscosity of 1,000 mPa in a bubble-free state. Above s, 50,000mPa. s below. Furthermore, the "bubble-free" described here The state is a state in which bubbles or the like which are contained in a very small amount before the foaming treatment is "bubble-free" before the foaming treatment.

In a preferred embodiment of the package having a cardboard according to the present invention, the foaming heat-fusible adhesive layer has a foaming ratio of 1.1 or more and 10 in accordance with the following formula (1). the following.

<number 1> V ₁ /V ₂ (1)

Wherein V ₁ is the volume of the foamed hot-melt adhesive layer recovered from the package of the above-mentioned cardboard, and V ₂ is the foamed hot-melt adhesive layer recovered from the package of the above-mentioned cardboard. The volume after defoaming by heating and melting.

Further, in a preferred aspect of the package having a cardboard according to the present invention, the film-wrapped article as the article packaged by the heat-shrinkable film is attached by using the foamed hot-melt adhesive layer. Attached to the above-mentioned cardboard to form a package with cardboard.

A method for producing a package having a cardboard according to a first aspect of the present invention includes a paperboard, an article packaged by the heat-shrinkable film, and a foamed hot-melt adhesive layer which bonds the heat-shrinkable film to the paperboard. The method for manufacturing a package having a cardboard, the method for manufacturing the package having the cardboard includes a step of coating the article with a film capable of heat shrinkage, and thermally shrinking the film; and preparing for reversible by heat Repeating the steps of melting and solidifying the hot-melt adhesive, and containing the bubbles in the hot-melt adhesive to form a foaming hot-melt adhesive; a step of forming a foamed hot-melt adhesive layer on at least one of the heat-shrinkable films; and a bonding step of joining the paperboard to the heat-shrinkable film via the foamed heat-fusible adhesive layer.

A method for producing a package having a cardboard according to a second aspect of the present invention includes a paperboard, an article packaged by the heat-shrinkable film, and a foamed hot-melt adhesive layer which bonds the heat-shrinkable film to the paperboard. The method for manufacturing a package having a cardboard, the method for producing the package having the cardboard includes: preparing a hot-melt adhesive which can be reversibly remelted and solidified by heat, and containing the air bubbles in the hot-melt adhesive; a step of forming a foaming hot melt adhesive; a step of forming a foamed hot-melt adhesive layer on at least one of the paperboard and the heat-shrinkable film using the foaming hot melt adhesive; a heat-fusible adhesive layer for bonding the paperboard to the heat-shrinkable film to obtain a bonding step of a paperboard having a heat-shrinkable film; and coating the article with the heat-shrinkable film The above film is subjected to heat shrinkage and formed into the above heat-shrinkable film.

In a preferred aspect of the method for producing a package having a cardboard according to the first aspect or the second aspect of the present invention, the hot-melt adhesive has a melt viscosity of 1,000 in a state of containing no bubbles. mPa. Above s, 50,000mPa. s below.

In a preferred aspect of the method for producing a package having a cardboard according to the first aspect or the second aspect of the present invention, the foamed hot-melt adhesive is obtained from the formula (2). The expansion ratio is 1.1 or more and 10 or less.

<number 2> V ₃ /V ₄ (2)

In the formula, V ₃ is a mass per 100 cc of the above-mentioned hot-melt adhesive before foaming, and V ₄ is a mass per 100 cc of the above-mentioned foamed hot-melt adhesive.

Further, in a preferred aspect of the method for producing a package having a cardboard according to the first aspect or the second aspect of the present invention, the method further comprises: maintaining the molten state of the foaming hot-melt adhesive to continuously perform the formation. a step of foaming the hot melt adhesive layer, and the above bonding step.

According to the present invention, it is possible to obtain an excellent effect of being able to expand a package of a cardboard which is an object of an article to be packaged in a shrink film package, and a method for producing the same.

1‧‧‧Package with cardboard

2‧‧‧Cardboard with heat shrinkable film

10‧‧‧Fixed film

11‧‧‧Heat-shrinkable film

12‧‧‧ cardboard

13‧‧‧ adhesive layer

14‧‧‧ hanging holes

15‧‧‧Perforation

16‧‧‧Opening

20‧‧‧ Items

21‧‧‧film packaging items

Fig. 1A is a schematic explanatory view showing an example of a package body of a cardboard according to the first embodiment.

Fig. 1B is a cross-sectional view of the IB-IB cut portion of Fig. 1A.

Fig. 2A is a schematic explanatory view showing a method of manufacturing a package with a cardboard according to the first embodiment;

Fig. 2B is a schematic explanatory view showing a method of manufacturing a package with a cardboard according to the first embodiment;

Fig. 2C is a schematic explanatory view showing a method of manufacturing a package with a cardboard according to the first embodiment.

Fig. 3 is a flow chart showing a first embodiment or a second embodiment in a method of manufacturing a package having a cardboard.

Fig. 4A is a schematic explanatory view showing an example of a package body of a cardboard according to a second embodiment.

Fig. 4B is a cross-sectional view of the cut portion of IVB-IVB of Fig. 4A.

Fig. 5A is a schematic explanatory view showing a method of manufacturing a package having a cardboard according to a third embodiment;

Fig. 5B is a schematic explanatory view showing a method of manufacturing a package having a cardboard according to a third embodiment;

Fig. 5C is a schematic explanatory view showing a method of manufacturing a package having a cardboard according to a third embodiment;

Fig. 6 is a flow chart showing a third embodiment or a fourth embodiment of the method for producing a package having a cardboard.

FIG. 7 is a conceptual diagram in which the adhesive strength with respect to the elapsed time after application of the reactive hot-melt adhesive described in Non-Patent Document 1 is plotted.

The package with cardboard of the present invention is obtained by joining a heat-shrinkable film obtained by packaging articles and a paperboard through an adhesive layer. The adhesive layer is characterized in that it is a foamed hot-melt adhesive layer containing a hot-melt adhesive which can be reversibly melted and cured by heat and contains bubbles. Hereinafter, specific embodiments of the package with paperboard of the present invention and a method for producing the same will be described. Furthermore, other embodiments are of course included in the scope of the present invention as long as they conform to the gist of the present invention. In addition, Matters other than those specifically mentioned in the present specification required for the implementation of the present invention can be grasped as design matters of those skilled in the art according to the prior art in the field. Further, the following embodiments can be combined with each other as appropriate.

[First Embodiment]

Fig. 1A is a schematic explanatory view showing a package body of a cardboard according to a first embodiment, and Fig. 1B is a cross-sectional view showing a IB-IB cutting portion of Fig. 1A. In the cardboard package 1, the film package article 21 is a packaged article attached to the paperboard 12 via the adhesive layer 13, and is bonded to the paperboard 12 by the heat-shrinkable film 11 via the adhesive layer 13. By. The package 1 having a cardboard may have other members without departing from the gist of the invention. For example, a cushioning material for preventing the impact of the product, a heat insulating member for preventing the heat from being received when the adhesive layer 13 is formed, a heat radiating member, and the like can be exemplified. Further, the adhesive layer 13 is a method in which the heat-shrinkable film 11 and the paperboard 12 are joined, but is not limited to the form in which the heat-shrinkable film 11 and the paperboard 12 are directly joined to the adhesive layer 13, and includes a barrier layer. A member such as another sheet formed of the heat-shrinkable film 11 and/or the cardboard 12 integrally joined to the adhesive layer 13.

The heat-shrinkable film 11 is a film which is responsible for packaging the article 20 by at least a part of the coated article 20, and is a film obtained by thermally shrinking a so-called shrink film. As in the example of FIG. 1A, a configuration may be exemplified in which the entire side surface portion of the article 20 is packaged by the heat-shrinkable film 11, or only the central portion of the article is packaged in a strip shape or the entire article is packaged. In order to confirm the state of the article at the packaging portion, the heat-shrinkable film 11 is preferably colorless or transparent, but may be opaque. In addition, rewritable text information can be printed on the heat-shrinkable film 11, and various types of printing can be printed. image.

The heat-shrinkable film 11 may be any one that heat-shrinks a film having heat shrinkability such as a stretched film, and a film that is generally used can be used without limitation. For example, polystyrene, polyethylene, polypropylene, and polyvinyl chloride can be exemplified. In addition, as a biodegradable film in consideration of the environment, a thermoplastic resin (polyester-based resin or the like) based on polylactic acid is also suitable. Corresponding to the demand, a perforation 15 as shown in FIG. 1A or an opening 16 formed with two or more perforations may be provided on the heat-shrinkable film 11.

The cardboard 12 mainly functions as a base material of the packaged article 20, and as an information providing unit such as an article name or article information. In the cardboard 12, a hanging hole 14 or the like may be provided as a display means of the article 20. The material of the cardboard 12 is not particularly limited as long as it is a material that does not deform when the article 20 is attached. As a suitable example, a polyester film such as a polyester film, a nylon film, a vinylidene chloride, a polyethylene or a polypropylene, or a plastic sheet containing the laminate, or a paper, a metal sheet, or a composite may be exemplified. A composite sheet of material, and a laminate of the same. For example, it may be a laminate of a plastic film and an aluminum foil. The thickness of the cardboard 12, the raw material, and the like may be appropriately selected in accordance with the quality, size, and the like of the article 20. Further, the cardboard 12 may have a curved shape, a curved shape, or the like in addition to the flat plate shape. In addition, it may be an L-shaped or U-shaped cardboard. Further, in order to easily take out the article 20 from the package 1 having the cardboard, a perforation or a slit may be provided in the vicinity of the contact portion of the article 20 on the back side of the cardboard 12 or the vicinity thereof.

The subsequent agent layer 13 is responsible for bonding the heat-shrinkable film 11 to the cardboard 12. The action includes a high-temperature melt-type foamed hot-melt adhesive layer containing a bubble in a hot-melt adhesive which exhibits reversible melting and solidification by heat. The adhesive layer 13 used in the present invention is an adhesive layer which is solid at normal temperature, can be applied to the joined portion after being melted by heating, and is returned to normal temperature after coating. The joined portion is cured to exert an adhesive force with the joined portion. That is, the adhesive used in the adhesive layer 13 of the present invention is an adhesive different from the following adhesive: after the heat-shrinkable film 11 is bonded to the paperboard 12, it is required to be used in the subsequent post-treatment step (using a reactive hot-melt adhesive for aging treatment by ultraviolet or thermal hardening or ultraviolet (UV) curing treatment, or a high-viscosity adhesive called so-called sealant . Further, the adhesive layer 13 may be a pressure-sensitive adhesive layer.

The hot-melt adhesive used in the present invention contains at least a thermoplastic resin and an adhesion-imparting resin. Further, the hot melt adhesive preferably contains a wax. Further, if necessary, a filler, a softener, a plasticizer, a colorant, an anti-caking agent, an antioxidant, an ultraviolet absorber, a decane coupling agent, a thixotropic agent, a foaming agent, etc. may be contained in the hot melt adhesive. . The hot melt adhesive is preferably free of solvent. The material of the hot-melt adhesive is not particularly limited as long as it does not deviate from the gist of the present invention, and the following examples are mentioned as suitable examples.

The thermoplastic resin may, for example, be a hot-melt adhesive such as a styrene polymer, an ethylene vinyl acetate (EVA), an ethylene-unsaturated ester copolymer, a polyamide, a polyester, or a polyolefin. These may also be block copolymers. As the styrene-based polymer, styrene-ethylene can be exemplified. Butene-styrene block polymerization Styrene-Ethylene-Butylene-Styrene (SEBS), styrene-ethylene. Styrene-Ethylene-Propylene-Styrene (SEPS), styrene-isoprene-styrene block polymer (Styrene-Isoprene-Styrene, SIS), styrene-butene. Butadiene-Butylene-Butadiene-Styrene (SBBS) and the like. The thermoplastic resin may be used singly or in combination of two or more.

The melt flow rate (MFR) (JIS K7210 200 ° C / 5 kg) of the thermoplastic resin to be used is preferably 0.01 g to 100 g (including the lower limit value and the upper limit value. The same applies hereinafter). By setting the MFR to 100 g or less, it is easy to obtain a balance between heat resistance and adhesion when a hot-melt adhesive is added by adding another component. On the other hand, by setting the MFR to 0.01 g or more, it is easy to maintain the adhesion in a low temperature environment. In the present invention, the term "MFR" refers to the mass of the thermoplastic resin obtained by using the method specified in JIS K7210 and using (temperature: 200 ° C, load: 5 kg) as a condition. The MFR of the thermoplastic resin is more preferably in the range of 0.1 g to 80 g, and more preferably in the range of 1 g to 70 g.

Examples of the adhesion-imparting resin include a phenol resin, a modified phenol resin, a terpene phenol resin, a xylenol resin, a cyclopentadiene-phenol resin, and a xylene resin. Further, petroleum resins such as aliphatic, alicyclic, and aromatic; petroleum resins such as hydrogenated aliphatic, alicyclic, and aromatic; and phenol-modified petroleum resins are also suitable. Further, a rosin-based resin such as a rosin ester resin or a hydrogenated rosin ester resin is also suitable. Further, a low molecular weight polystyrene resin, a terpene resin, a hydrogenated terpene resin, or the like can also be exemplified. The adhesion-imparting resin may be used singly or in combination of two or more kinds. use.

The softening point of the adhesion-imparting resin to be used is preferably from 80 ° C to 160 ° C. By setting the softening point to 80 ° C or higher, even at a high temperature, it is difficult to break the bubbles in the hot-melt adhesive after foaming, and the adhesion can be improved. On the other hand, by setting the softening point to 160 ° C or lower, the viscosity in a low-temperature environment can be improved, and the adhesion can be favorably maintained. In the present invention, the softening point means a temperature determined by a method defined in JIS K 6863. From the viewpoint of achieving a balance between adhesion, heat resistance and cold resistance, a more preferable range of the softening point of the adhesion-imparting resin is from 90 ° C to 140 ° C, and more preferably in the range of from 100 ° C to 130 ° C.

As the wax, palm wax, Candelilla wax, montan wax, paraffin wax, micro wax, Fischer-Tropsch wax, polyethylene wax, polypropylene wax, and the like are mentioned. Some wax oxides, ethylene-acrylic acid copolymers, ethylene-methacrylic acid copolymers, and the like. The wax may be used singly or in combination of two or more. The melt viscosity of the wax at 150 ° C is preferably 10 mPa. s~2,000mPa. s, more preferably 15mPa. s~1,000mPa. s, and more preferably 15mPa. s~500mPa. s. By using a wax, the viscosity of the hot melt adhesive can be lowered to facilitate coating.

The softening point of the wax used is preferably from 70 ° C to 120 ° C. By the softening point becoming 70 ° C or more, there is no possibility that the wax melts at a high temperature and then the force is lowered. On the other hand, by setting the softening point to 120 ° C or lower, the temperature at which the hot melt adhesive is heated and melted is lowered, so that the coatability of the hot melt adhesive can be ensured. In the present invention, the softening point means a temperature determined by a method defined in JIS K 6863. A more preferable range of the softening point of the wax is from 80 ° C to 140 ° C, and a more preferred range is 90 ° C. ~130 °C.

As a coloring agent, a titanium oxide etc. are mentioned.

Examples of the anti-caking agent include saturated fatty acid guanamine such as anthrone, erucic acid amide or oleic acid amide, saturated fatty acid guanamine such as decyl stearate or decyl phthalate.

Examples of the antioxidant include high molecular weight hindered polyphenols, triazine derivatives, high molecular weight hindered phenols, and dialkyl groups. phenol. Sulfide, 2,2-methylene-bis-(4-methyl-6-tert-butylphenol), 4,4-methylene-bis-(2,6-di-t-butylphenol , 2,6-di-t-butylphenol-p-cresol, 2,5-di-t-butyl hydroquinone, 2,2,4-trimethyl-1,2-di-p-benzene Diphenol, 2,2,4-trimethyl-1,2-dihydrobenzene, dibutyl. Nickel dithiocarbamate, 1-oxy-3-methyl-4-isopropylbenzene, 4,4-butylenebis-(3-methyl-6-tert-butylphenol), 2- Mercaptobenzimidazole and the like.

In the hot-melt adhesive used in the present invention, the thermoplastic resin is preferably in the range of 30 parts by mass to 80 parts by mass in 100 parts by mass of the hot-melt adhesive, from the viewpoint of improving heat resistance. From the viewpoint of the force, it is preferred to contain the adhesion-imparting resin in the range of 40 parts by mass to 80 parts by mass. Further, from the viewpoint of appropriately adjusting the viscosity, it is preferred to use a wax.

The softening point of the hot-melt adhesive used in the present invention may vary depending on the temperature of use, but it is preferably 80 to 160 ° C if it is also considered to be used outdoors. By changing the softening point to 80 ° C or higher, it is easy to obtain a balance between the adhesion force and the cohesive force. On the other hand, by setting the softening point to 160 ° C or lower, it is easy to maintain the viscosity even in a low temperature environment. In the present invention, the softening point means a temperature determined by a method defined in JIS K 6863. Softening point of the hot melt adhesive of the present invention A more preferred range is from 90 ° C to 140 ° C, and a more preferred range is from 100 ° C to 130 ° C.

The foaming ratio determined by the following formula (1) of the adhesive layer 13 is preferably in the range of 1.1 to 10 from the viewpoint of effectively maintaining the adhesion or the followability. By setting it as this range, the adhesiveness and followability at the time of high temperature use can be guided more effectively. More preferably 1.5 to 5, and even more preferably 1.5 to 3.

<Number 3> V ₁ /V ₂ (1)

Wherein V ₁ is the volume of the foamed hot-melt adhesive layer recovered from the package having the cardboard, and V ₂ is the heating and melting of the foamed hot-melt adhesive layer recovered from the package with the cardboard. The volume after soaking.

For example, it can be calculated by collecting the foamed hot-melt adhesive layer per 1 cm ² to obtain a volume, and thereafter, determining the volume of the adhesive after heat-melting to completely defoam the bubbles. Further, the volume of the adhesive after the recovery and the defoaming can be determined by using a measuring instrument such as a pycnometer for measuring the porosity of the powder. That is, any amount of the hot melt adhesive can be detached, and the hot melt adhesive is added to the measuring device of the known container volume, and then the mass is measured, according to the difference in mass after adding water in a void-free manner. The volume of the hot melt adhesive is determined based on the specific gravity of the water.

The article 20 is not particularly limited as long as it is suitable for being packaged by the heat-shrinkable film 11. For example, cosmetics, medicines, foods, batteries, toys, clothes, stationery, groceries, and the like can be exemplified. The number of articles 20 to be packaged may be singular or plural. In addition, the purpose of packaging is first displayed in the form of a product as a product, and can be used for various purposes such as transportation and packaging.

Next, an example of a method of manufacturing a package having a cardboard according to the first embodiment will be described with reference to FIGS. 2A to 2C and FIG. In the method for producing a package having a cardboard according to the first embodiment, a package having a cardboard is produced by coating the article 20 with a film 10 capable of heat shrinkage, and heating the film 10 capable of heat shrinkage. The film package article 21 packaged by the heat shrinkable film 11 is produced, and then the film package article 21 is attached to the cardboard 12 via the adhesive layer 13. The details will be described below.

First, the article 20 is wrapped with the film 10 which is heat-shrinkable, and the film packaged article 21 packaged by the heat-shrinkable film 11 is obtained (step 1). In the example of FIGS. 2A to 2C, the article 20 is inserted into a cylindrical heat-shrinkable film 10 (see FIG. 2A), and then heated by a film capable of heat shrinking. The heat-shrinkable film shrinks, and the heat-shrinkable film 11 is attached (closed) to the article 20 (refer to FIG. 2B). The method of heating the film 10 which can be heat-shrinked to cause heat shrinkage can be arbitrarily applied to a conventionally used method. By these steps, the film packaged article 21 covered by the heat-shrinkable film 11 is obtained. The film 10 which can be heat-shrinked can be cut by using it individually beforehand, or can be cut by the heat-shrinkable film 10 wound up in a roll shape just before heat shrinking.

The heat-shrinkable film 10 is printed as necessary or formed into perforations 15, slits, embossing, opening 16 and the like, and is prepared in a desired size or shape. Further, the film 10 which can be thermally contracted is selected as needed depending on the direction. In addition, the example of FIG. 2A and the like is an example, and various modifications are possible. For example, a sheet-like heat-shrinkable film 10 may be wound around the article 20 and the overlap portion may be used to bond the overlap portion. They are joined to each other. Alternatively, the sheet-like heat-shrinkable film 10 or the strip-shaped heat-shrinkable film 10 may be directly wound around the article 20 without using an adhesive. As a method of directly using the sheet-like heat-shrinkable film 10, for example, a method in which the heat-shrinkable film 10 is wound around the side (body portion) of the article 20 for one or more times and heated rapidly is exemplified. The heat-shrinkable film 10 is heat-shrinked, and the heat-shrinkable film 11 is bonded (closed) to the article 20. In the case of a strip-shaped heat-shrinkable film 10, the same method can also be exemplified.

The film package article 21 can be manufactured by the step of manufacturing the package 1 having a cardboard, or can be packaged at the same time as the finished product in a factory or the like for manufacturing the article 20. When the package is packaged at the same time as the finished product, the article can be properly protected during transportation or storage.

Next, an adhesive layer 13 is formed on the paperboard 12 or/and the heat-shrinkable film 11 (step 2). In the first embodiment, an example in which the adhesive layer 13 is formed on the cardboard 12 will be described. The cardboard 12 is printed, decorated, formed into a hanging hole 14, and the like as needed. On the side of the cardboard 12, a perforation for easily taking out the article 20 or a slit for unsealing or the like may be provided. The cardboard 12 can be cut according to each product in advance, or can be cut before and after the application of the adhesive. Further, the cardboard 12 can be separated at the final stage after the film package article 21 is attached. From the viewpoint of making the manufacturing steps efficient, the following method can be exemplified: the paperboard 12 is first wound into a roll, and is cut in the step of manufacturing the package 1 having the cardboard.

The subsequent layer 13 comprises a foamed hot-melt adhesive layer as described above, the foamed hot-melt adhesive layer being reversibly melted and cured by heat reversibly. Contains bubbles. The timing at which the hot-melt adhesive is foamed is not particularly limited. However, from the viewpoint of improving productivity and managing quality with high precision, it is suitable to apply immediately before the formation of the adhesive layer 13. The hot melt adhesive is foamed at or just after application. Among these, it is more preferable to foam the hot-melt adhesive just before or during coating. The subsequent agent layer 13 can be obtained by applying a molten hot melt adhesive to a prescribed position of the cardboard 12.

The method or apparatus for containing the bubbles in the hot-melt adhesive is not particularly limited, but a method of foaming the hot-melt adhesive by blowing a gas is suitable. Further, the heat-decomposable foaming agent may be added to the hot-melt adhesive first to form fine bubbles when the adhesive layer 13 is formed.

The apparatus which blows a gas into a hot-melt adhesive agent and foams, for example, can be exemplified by the following apparatus, including the heating-stirding container which melt-heats a hot-melt adhesive agent under normal pressure or pressure, and volatil a volatile substance supply device introduced into the heating and agitating vessel, a sensor for monitoring the temperature or viscosity in the agitating vessel, a stirring device disposed in the heating and agitating vessel, and a heat-fusible adhesive The control unit or the like for controlling the stirring condition (rotation speed, etc.) such as the viscosity. The volatile matter is not particularly limited, and an inert gas such as nitrogen or argon may be exemplified, and nitrogen gas may be suitably used.

Further, a gas which can be held inside the adhesive layer by interacting with a component of the adhesive between the molecules can also be used. Although depending on the kind of the adhesive layer, carbon dioxide can be exemplified as such an example. The gas can be introduced under normal pressure, but it is efficient to introduce it under pressure. In addition, supercritical carbon dioxide or the like can also be used.

From the viewpoint of efficiently introducing bubbles, the melt viscosity of the hot melt adhesive when blowing a gas is preferably included in 1,000 mPa. s~50,000mPa. In the range below s, more preferably 5,000 mPa. s~20,000mPa. The range of s is particularly good at 5,000mPa. s~15,000mPa. The scope of s. The temperature at which the hot-melt adhesive is foamed is usually from 120 ° C to 180 ° C, preferably from 120 ° C to 150 ° C, depending on the type of hot-melt adhesive to be used. After the foaming hot melt adhesive is formed, it is usually returned to normal temperature. Thereby, the adhesive is cured, and the foamed portion is also fixed.

The appropriate expansion ratio of the hot-melt adhesive can be changed depending on the use or demand, and can be arbitrarily set. From the viewpoint of improving the versatility of the shape of the article, the ratio of the mass when filled in a container of 100 cc in a molten state is preferably in the range of 1.1 to 10 in the following formula (2). . More preferably 1.5 to 5, and particularly preferably 1.5 to 3.

<Number 4> V ₃ /V ₄ (2)

In the formula, V ₃ is a mass of 100 cc of the unfoamed hot-melt adhesive, and V ₄ is a mass of 100 cc of the foamed hot-melt adhesive.

Then, the film packaged article 21 packaged by the heat-shrinkable film 11 and the paperboard 12 are bonded together via an adhesive layer (foamed hot-melt adhesive layer) 13 (step 3, see FIG. 2C). At the time of bonding, the molten adhesive layer 13 is required to be in contact with the joined portion, and thereafter the adhesive layer 13 is cured. Therefore, from the viewpoint of productivity, it is preferable to continuously carry out the step 2 in a state in which the molten state of the adhesive layer 13 is maintained. The step of forming the agent layer 13 and the step of bonding the film package article 21 of the step 3 to the paperboard 12. As a preferable example, for example, a method in which a binder in a molten state is foamed while being applied to a predetermined position of the cardboard 12 to be melted can be exemplified. The adhesive layer 13 in a foamed state is rapidly contacted with the film-packaged article 21 packaged by the heat-shrinkable film while maintaining the state, and then the adhesive layer 13 is cured while being naturally cooled, and the adhesive layer 13 is cured. fit.

The joining method of the film package article 21 and the cardboard 12 is not limited to the above method, and various modifications can be made. For example, it can also be melted. After the hot-melt adhesive in a foamed state is applied to a predetermined position of the cardboard 12, the adhesive layer 13 is temporarily cooled, and when the film-packaged article 21 and the paperboard 12 are attached, it is heated again to maintain the adhesive layer. The degree of foaming of 13 is such that the film package article 21 is attached to the melt. On the adhesive layer 13 in a foamed state. According to this method, the respective manufacturing steps of the cardboard 12 having the adhesive layer 13, the film package article 21, and the package 1 having the cardboard can be carried out at different points in time or places. Heating for melting the adhesive layer 13 for joining the film package article 21 and the paperboard 12 may be performed from the back side or the side surface of the paperboard 12 in addition to the surface of the adhesive layer 13. For example, the film package article 21 and the paperboard 12 can be joined from the back side of the paperboard 12 by the hot air to melt the adhesive layer 13 to a state where the foamed state can be maintained. Further, it is also possible to heat using a lamp or the like. Further, in the case where the cardboard 12 is made of plastic, it may be carried out by using steam.

The adhesive layer 13 in the cardboard package 1 can be visually confirmed to be foamed. However, the expansion ratio is usually smaller than the value of the above formula (2). The reason is: When the film package article 21 covered with the heat-shrinkable film 11 and the paperboard 12 are attached, the air bubbles in the adhesive layer 13 are reduced. In addition, the reason is that the bubbles are joined to each other due to the mass of the article 20 or the like, or the bonding force is increased by the adhesive properties of the adhesive layer 13 itself, so that the bubble may be broken and the apparent expansion ratio may be reduced. . Therefore, in the manufacturing step or the elapsed time, the expansion ratio becomes slightly smaller than the initial stage. From the viewpoint of effectively maintaining the adhesion or the followability, as described above, the expansion ratio of the adhesive layer 13 in the package 1 having a cardboard is preferably such that the value obtained in the above formula (1) is at the above Within the prescribed range.

According to the method of attaching the film 10 which is heat-shrinkable to the paperboard 12, inserting the article, and then heating and converting it into the heat-shrinkable film 11, in particular, an article to be packaged in a poorly balanced shape, an article that is easy to move In the case of a plurality of articles or the like, there is a possibility that the positional deviation of the article 20 is generated. On the other hand, according to the method for manufacturing a package with a cardboard according to the first embodiment, since the film-packed article 21 is formed first and then attached to the cardboard 12, it is possible to prevent the article from being produced with respect to the cardboard 12. Position offset. In particular, it can be suitably applied to the case where the article 20 has a poor balance shape, the case where the article 20 is an article that is easy to move, or the case where a plurality of articles are to be packaged.

However, in order to improve the heat resistance of the adhesive layer, an adhesive which is not easily softened at a high temperature is generally used. However, when an adhesive which is not easily softened at a high temperature is used, the adhesive layer has a drawback that it is hard at a low temperature and is easily broken. Further, when an adhesive which is not easily softened at a high temperature is used, the followability of the adhesive layer to a minute uneven surface is deteriorated, and the surface followability is also deteriorated. In addition, it is active actively in recent years The developed reactive hot-melt adhesive is required to be used for moisture hardening or UV hardening treatment after the film which is heat-shrinkable is bonded to the paperboard via an adhesive. By these hardening treatments, it is conceivable that the hardenability of the adhesive layer is improved and the heat resistance is increased. However, although heat resistance is improved by hardening, correspondingly, the elasticity of the adhesive layer is lowered, and the followability is lowered. The decline in follow-up is especially problematic at low temperatures. Further, as a method of increasing the adhesion force, there is a method of improving the wettability to the heat-shrinkable film or paperboard by making the temperature of the adhesive higher to lower the viscosity. However, if the temperature of the adhesive is simply increased, thermal damage to the article cannot be ignored.

According to the package 1 having a cardboard according to the first embodiment, the adhesive layer 13 is foamed, and the elastic property and the adhesive force are superior to those of the unfoamed adhesive layer. Since the adhesive layer 13 is elastic, even a hard adhesive excellent in heat resistance can be used to improve the elasticity by foaming, and it is difficult to break at a low temperature. Moreover, by the improvement of the elastic property, when the paperboard 12 and the film package article 21 are bonded together, the followability of the adhesive layer 13 is improved, and the adhesive layer 13 follows the cardboard 12 or the heat-shrinkable film 11 well. Or tiny irregularities on the surface of the item. It is considered that the reason why the adhesion force becomes large is that the adhesion area of the adhesive layer 13 and the joined portion is increased.

In the shrink wrap packaging, as described above, it is required to enlarge the object of the packaged article. The article to be packaged has various shapes, and has a shape in which a part of the side surface of the article has a curved shape which is formed by thinning in the middle. Such a curved surface portion is easily floated when the film packaged article 21 is joined to the paperboard 12. According to the package 1 having a cardboard according to the first embodiment, in the case of such an article, By using a resilient adhesive layer, it is also possible to increase the bonding area by pressing the above-mentioned intermediate tapered portion against the cardboard 12, thereby sufficiently improving the adhesion. Therefore, the application target of the article 20 as the packaged object can be expanded.

In addition, by using the foamed adhesive layer 13, heat damage to the article 20 can be reduced as compared with the case of using an unfoamed hot melt adhesive. The reason for this is that the thermal conductivity is lowered by the bubbles existing in the foamed adhesive layer 13, so that the heat transfer to the article 20 can be suppressed, and the bubble is contained in the adhesive layer 13 Moreover, the cooling efficiency after heating and melting can be improved, and the heat load at the time of joining can be reduced. In other words, the wettability of the heat-shrinkable film 11 or the paperboard 12 can be improved by using the adhesive layer 13 having a high temperature and a low viscosity while suppressing thermal damage. Further, by increasing the wettability, the type of the article to be packaged can be expanded.

Further, according to the package with a cardboard according to the first embodiment, since the foamed hot-melt adhesive layer is used, the specific gravity can be lowered and the amount of the adhesive used can be reduced. As a result, each product can be slightly lighter, and when a large number of products are transported, the total cost including transportation costs can be reduced. Further, according to the package with cardboard of the present invention, since the hot-melt adhesive which can be reversibly melted and solidified by heat is used, there is an advantage that the film which can be heat-shrinked and the paperboard are joined by only the separation. The step of bonding in the molten state is carried out (the post-processing step is not required).

[Second Embodiment]

Next, an example of a method of manufacturing a package having a cardboard different from the above embodiment will be described. The method for producing a package having a cardboard according to the second embodiment is the same as the first embodiment except for the following points. That is, the second In the embodiment, the adhesive layer 13 is formed on the film package article 21, and then attached to the paperboard 12, and the adhesive layer 13 is formed on the paperboard 12, and then bonded to the film packaged article. The manufacturing method of the first embodiment on 21 is different.

According to the method for producing a package having a cardboard according to the second embodiment, after the film-packed article 21 packaged by the heat-shrinkable film 11 as shown in Fig. 2B is obtained, it is melted. The adhesive layer 13 in a foamed state is placed at a predetermined position of the film package article 21, and then joined to the cardboard 12.

According to the method of the second embodiment, the same effects as those of the first embodiment described above can be obtained. Further, since the adhesive layer 13 is formed on the film package article 21, when the film package article 21 and the paperboard 12 are joined, the position of the adhesive layer 13 and the joint position can be more reliably prevented from shifting. If heat is considered for the heat-shrinkable film 11 or article 20, it is preferably melted. The adhesive layer 13 in a foamed state is formed on the cardboard 12 side as shown in Fig. 2C. However, for example, as shown in FIG. 4A to FIG. 4B, the method of the second embodiment is useful when the article is a case where the width of the toothbrush is small or the like, and the joint is likely to be defective due to a slight positional deviation. Further, the method of the second embodiment is also useful when a sheet of cardboard is to be joined to a plurality of film-wrapped articles 21 or when an article having a complicated shape such as a concave portion is to be packaged.

[Third embodiment]

The method for producing a package having a cardboard according to the third embodiment is the same as the first embodiment except for the following points. That is, the manufacturing method of the third embodiment is a method of producing a paper having a film capable of heat shrinkage. The board is then inserted into the film 10 which is heat-shrinkable, and then the heat-shrinkable film 10 is heat-shrinked to manufacture a package having a cardboard. In other words, the third embodiment differs from the first embodiment in that the cardboard 12 is bonded to the heat-shrinkable film 10 before the step of coating the article. The third embodiment will be described with reference to Figs. 5A to 5C and Fig. 6 .

In the third embodiment, first, as shown in FIG. 5A, an adhesive layer 13 is formed on the cardboard 12 (step 1a). As described above, the adhesive layer 13 is a foamed hot-melt adhesive layer in which bubbles are contained in a hot-melt adhesive which can be reversibly melted and cured by heat reversibly. The method of foaming a hot melt adhesive agent is the same as that of the first embodiment.

After that, it is melted through. The adhesive layer 13 in a foamed state contacts the heat-shrinkable film 10 at a predetermined position of the cardboard 12 and then presses it at a predetermined pressure, thereby bonding the heat-shrinkable film 10 to the paperboard 12 to obtain a mold. Heat-shrinkable film paperboard 2 (step 2a, see Figure 5B). For example, the film 10 that can be thermally contracted can be rolled with the paperboard 12 at a desired pressure using two pressing rolls. From the viewpoint of the efficiency of the production step, the steps 1a and 2a preferably provide heat shrinkage immediately after the application of the adhesive layer 13 while maintaining the molten hot-melt adhesive in a molten state. The film 10 is bonded to the cardboard 12. In addition, in FIG. 5A and FIG. 5B, the film 10 which can be heat-shrink|circulated is a cylindrical film, However, as for the case of 1st Embodiment, it can also use the sheet| The film 10 is wound into a cylindrical shape, and the overlapping portions are joined by an adhesive.

It is preferably melted through the membrane. The adhesive layer 13 in a foamed state enables After the heat-shrinkable film 10 is bonded to the cardboard 12, it is cooled by curing the adhesive layer 13. Cooling can be either natural cooling or forced cooling. By this step, the heat-shrinkable film 10 is bonded to the paperboard 12, and a paperboard 2 having a heat-shrinkable film is obtained (see Fig. 5B).

Then, the article 20 as a packaged object is inserted into a cylindrical heat-shrinkable film 10 (refer to FIG. 5C), and then the heat-shrinkable film 10 is heat-shrinked, thereby obtaining, for example, FIG. 1A. A package of cardboard having the article 21 packaged by the heat-shrinkable film 11 is fixed to the cardboard 12 (step 3a). Further, the paperboard 12 coated with the adhesive layer 13 may be prepared in advance, and when the heat-shrinkable film 10 and the paperboard 12 are joined together, the adhesive layer 13 may be heated and melted again to carry out the paperboard 12 and the paperboard 12 The heat shrinkable film 10 is joined.

In the adhesive layer 13 of the paperboard 2 having a heat shrinkable film according to the third embodiment, foaming can be visually confirmed. However, the expansion ratio is usually smaller than the value of the above formula (2). The reason for this is that the film step of thermally shrinking the heat-shrinkable film 10 after the step of attaching the film 10 and the paperboard 12 which can be heat-shrinked or after inserting the article 20 into the heat-shrinkable film 10 The bubbles in the adhesive layer 13 are reduced. Further, the bonding force is increased by the subsequent characteristics of the adhesive layer 13 itself, and therefore the bubble may be broken to cause an apparent expansion ratio to decrease. Further, there is a case where the air bubbles are joined to each other due to the quality of the articles or the like after the article is inserted. Therefore, in the manufacturing step or the elapsed time, the expansion ratio becomes slightly smaller than the initial stage. From the viewpoint of effectively maintaining the adhesion or followability, as described above, the expansion ratio of the adhesive layer in the paperboard of the film which can be heat-shrinked, and the package of the cardboard after the insertion of the article The expansion ratio of the coating layer is preferably such that the value obtained by the above formula (1) is within the above-specified range.

According to the package with a cardboard of the third embodiment and the method for producing the same, since the foamed hot-melt adhesive layer is used, the same effects as those of the first embodiment described above can be obtained.

[Fourth embodiment]

Next, an example of a method of manufacturing a package having a cardboard different from the third embodiment will be described. The method for producing a package having a cardboard according to the fourth embodiment is the same as the third embodiment except for the following points. That is, in the fourth embodiment, when a paperboard having a film capable of heat shrinkage is produced, the adhesive layer 13 is formed on the heat-shrinkable film 10, and then bonded to the paperboard 12, The manufacturing method of the third embodiment in which the adhesive layer 13 is formed on the cardboard 12 and then bonded to the heat-shrinkable film 10 is different.

In the fourth embodiment, first, the adhesive layer 13 is formed on the film 10 which can be thermally contracted (step 1a). Then, it is attached to the cardboard 12, whereby a paperboard having a heat shrinkable film as shown in Fig. 5B is obtained. Thereafter, as shown in FIG. 5C, the article 20 to be packaged can be inserted into the heat-shrinkable film 10 and heat-treated, whereby the heat-shrinkable film 10 is thermally shrunk and adhered to the article. 20, thereby obtaining a package with cardboard as shown in FIG.

According to the method of the fourth embodiment, the same effects as those of the third embodiment described above can be obtained.

"Embodiment"

Hereinafter, the present invention will be described in more detail and by way of examples, but these examples are only one embodiment of the invention, and the invention is not limited by the examples. Further, in the examples, "parts" means "parts by mass", and "%" means "mass%".

[Production Example (Production Example of Foaming Hot Melt Adhesive)]

<Manufacturing Example 1>

480 g of a thermoplastic elastomer (hereinafter, simply referred to as "elastomer") and 8 g of an antioxidant are added to a table kneading machine (PNV-1H manufactured by Izumi Chamber of Commerce) equipped with a heating device, and The mixture was heated and stirred at 120 ° C to 140 ° C for 3 hours. The vacuum pump is used to reduce the pressure during the stirring to prevent thermal deterioration. It was confirmed that there was no dissolution residue of the elastomer, and the hot-melt adhesive of Production Example 1 was obtained.

<Production Example 2 to Production Example 8>

The hot-melt adhesives of Production Examples 2 to 8 were obtained in the same manner as in Production Example 1 except that the type, the number of parts, and the stirring conditions of the adhesion-imparting resin and the elastomer were changed according to Table 1.

The abbreviations of the adhesion-imparting resin, the elastomer, and the antioxidant described in Table 1 are shown below.

Adhesive imparting resin 1: aromatic partial hydrogenated resin, softening point is 100 ° C

Adhesive imparting resin 2: aromatic hydrogenated resin, softening point is 100 ° C

Adhesive imparting resin 3: partially hydrogenated terpene resin, softening point is 105 ° C

Adhesive imparting resin 4: hydrogenated terpene resin, softening point is 105 ° C

Adhesive imparting resin 5: rosin ester, softening point is 108 ° C

Adhesive imparting resin 6: hydrogenated rosin ester, softening point is 105 ° C

Elastomer 1: Styrene-isoprene-styrene copolymer

MFR is 15g/10min (JISK7210 200°C/10kg)

Elastomer 2: Styrene-ethylene/polyisoprene-styrene copolymer

MFR is 100g/10min (JISK7210 200°C/10kg)

Elastomer 3: styrene-butadiene-styrene copolymer

MFR is 20g/10min (JISK7210 200°C/5kg)

Elastomer 4: Styrene-ethylene/butylene-styrene copolymer

MFR is 8g/10min (JISK7210 200°C/5kg)

Elastomer 5: styrene-isoprene/butadiene-styrene copolymer

MFR is 11g/10min (JISK7210 200°C/5kg)

Elastomer 6: Styrene-hydrogenated poly(isoprene/butadiene)-styrene copolymer

MFR<0.1g/10min (JISK7210 200°C/10kg)

Antioxidant: Phosphorus processing stabilizer + hindered phenolic antioxidant with a density of 1.1g/cm ² (20°C)

<softening point>

The measurement was carried out by a ring and ball method. The sample was filled into a prescribed ring and then kept horizontally in a glycerin bath. A predetermined ball (JIS B 1501) is placed in the center of the sample, and the temperature of the glycerin is raised at a predetermined speed to soften the sample, and the temperature of the ball or the ball is brought into contact with the bottom plate of the ring table by the weight of the ball. Set to softening point (JIS K 6863).

<viscosity>

300 g of a hot-melt adhesive in a state without bubbles was added to a 500 mL-capacity can. After the temperature of the hot melt adhesive is changed to 180 ° C, the rotor M4 is placed in a B-type rotational viscometer (RB80L type viscometer), and immersed in hot melt. In the agent up to the rotor marking. Further, the value at the time of rotation at 12 rpm for 30 seconds was defined as viscosity (JIS K 6862).

<Example 1 to Example 8 (sample preparation 1)>

500 g of the hot-melt adhesives of Production Examples 1 to 8 was placed in a melting tank of a foaming hot melt coating apparatus (CF-03 manufactured by Suntool Co., Ltd.), and heated to 180 °C. Set the hose and nozzle to 180 °C. The expansion ratio was set to 2.5, and about 0.4 g of the adhesive was applied to a paperboard having a width of about 5 mm and a length of about 10 cm. The conversion coating amount was set to 4 g/m.

In addition, an elliptical cylindrical plastic bottle (total mass: 140 g) having a sunscreen gel of 120 mL is prepared as an article, and the article is wrapped with a film which is heat-shrinkable with a perforation, and then hot air is blown by a dryer to obtain A packaged article (an article wrapped by a heat-shrinkable film) obtained by shrinking the heat-shrinkable film described above.

A foamed hot-melt adhesive layer was formed on the paperboard, and the heat-shrinkable film of the packaged article was bonded to the paperboard after an open time of 8 seconds, thereby obtaining the tests of Examples 1 to 8. Sample (package with cardboard).

<Comparative Example 1 to Comparative Example 8 (sample preparation 1)>

The comparison was made in the same manner as in the above-described Examples 1 to 8 except that the hot-melt adhesives of Production Examples 1 to 8 were not subjected to a foaming treatment (also referred to as "foaming magnification 1" for convenience of explanation). Samples of Examples 1 to 8 (packages with cardboard).

The heat-shrinkable film (hereinafter also referred to as "shrink film") of the sample produced by using the hot-melt adhesives of Production Examples 1 to 8 was subjected to a heat damage test and connected. Sexual test. In addition, in order to evaluate the adhesion of the hot-melt adhesive depending on the presence or absence of foaming, the heat-melting adhesives of Production Examples 1 to 8 were used to obtain the adhesion force in the same volume for each of the foamed and unfoamed samples. . The evaluation results are shown in Table 2.

<Thermal damage test for shrink film>

The shrink film of the sample (package of cardboard) obtained in the sample 1 was peeled off from the perforated sample, and the plastic bottle as the article was removed, and the foamed hot-melt adhesive layer (Example) and unfoamed were confirmed. The state of heat shrinkage of the shrink film (heat-shrinkable film) which the hot-melt adhesive layer (comparative example) contacted was evaluated, and the thermal damage to the shrink film was evaluated on the following basis.

○: No wrinkles or shrinkage were observed in the shrink film.

×: wrinkles and shrinkage were observed in the shrink film.

<adhesion test>

The state of the adhesiveness of the adhesive layer in the samples of the respective examples and the comparative examples obtained in the sample preparation 1 was evaluated by visual observation and according to the following criteria.

◎: The shrink film and the paperboard were followed by and excellent in followability to the curved surface.

○: The shrink film and the paperboard are next.

X: The shrink film and the paperboard were subsequently adhered to the defective portion.

<Adhesion force at the same volume>

On a paperboard, 6 mL of a hot-melt adhesive (foamed hot-melt adhesive with a foaming ratio of 2.5, a non-foamed (foaming ratio of 1) hot-melt adhesive) was applied to a width of about 10 mm and a thickness. It was about 5 mm in a bead shape, and after 10 seconds of the open time, a film which can be heat-shrinked was bonded, and a sample was produced. Then, after the hot-melt adhesive was sufficiently cooled, the temperature was adjusted in a constant temperature room at 23 ° C for 10 minutes, and then measured under a 23 ° C environment at a peeling angle of 180 ° and peeled off at a temperature of 300 mm / min. The force of the next. The obtained adhesion was evaluated on the basis of the following criteria.

○: The peel strength was 20 N or more.

×: The peel strength was less than 20N.

<Examples 9 to 14 and Comparative Example 9 (sample preparation 2)>

In the same manner as in Example 1 and Comparative Example 1, except that the hot-melt adhesive of Production Example 4 shown in Table 1 was used, and the expansion ratio was appropriately set to 1 to 10, Examples 9 to 14 were obtained in the same manner as in Example 1 and Comparative Example 1. The sample of Comparative Example 9 (package with cardboard).

The sample prepared using the obtained hot melt adhesive was subjected to 50 ° C Exfoliation test, adhesion test at 23 ° C and 0 ° C. The evaluation results are shown in Table 3.

<Exfoliation in 50 ° C>

The sample obtained in the sample preparation 2 was hung in an oven adjusted to temperature at 50 ° C, and the state of the sample stored at 72 hours was evaluated according to the following criteria.

○: The peeling of the unpackaged article and the positional offset of the unattached position.

△: peeling of the unpackaged article, but an offset of less than 10 mm was observed at the attached position.

×: There is peeling of the packaged article, or/and an offset of 10 mm or more is seen at the attached position.

<24°C adhesion force>

The shrink film of the sample obtained in 2 was peeled off from the sample, and the plastic bottle was removed, and the temperature was adjusted in a constant temperature room at 23 ° C for 10 minutes, and then measured at a peeling angle of 180° and 300 mm/min in an environment of 23° C. The adhesion at the time of peeling was evaluated, and the adhesion force at 23 ° C was evaluated according to the following criteria.

○: The peel strength was 10 N or more.

△: The peel strength was 5 N or more and less than 10 N.

×: The peel strength was less than 5N.

<4°C in the adhesion>

The shrink film of the sample obtained in 2 was peeled off from the sample, and the plastic bottle was removed, and the temperature was adjusted in an environment of 0 ° C for 10 minutes, and then measured at a peeling angle of 180° and 300 mm/min in a 0° C. environment. The adhesion is based on the following criteria.

○: The peel strength was 5 N or more.

△: The peel strength was 1 N or more and less than 5 N.

×: The peel strength was less than 1 N.

It can be seen that Examples 1 to 8 (see Table 2) of a foamed hot-melt adhesive having a foaming ratio of 2.5 and an unexpanded (foaming ratio of 1.0) using the same hot-melt adhesive were thermally welded. In comparison with Comparative Example 1 to Comparative Example 8 of the primer, excellent adhesion was obtained. Further, it is understood that the thermal damage to the shrink film is also small as compared with the unfoamed by foaming the hot melt adhesive.

Further, from the results of Examples 9 to 14 of Table 3, it was found that a more excellent adhesion can be obtained when the expansion ratio is 1.5 to 5. In addition, in the case of producing the package having the cardboard, the package was stored at 23 ° C for 3 months, and then the foamed state of the foamed hot-melt adhesive layer was confirmed, and it was confirmed that it was included in the formula ( 1) The expansion ratio is in the range of 1.1 to 10.

<attachment>

The present specification also discloses the following techniques that are grasped according to the above embodiments. The invention of thought.

(Note 1)

A paperboard having a film capable of heat shrinkage, comprising paperboard; a heat shrinkable film for packaging articles; and an adhesive layer for bonding the heat shrinkable film to the paperboard, and the above adhesive The layer is a foamed hot-melt adhesive layer containing bubbles in a hot-melt adhesive which can be reversibly melted and cured by heat reversibly.

(Note 2)

A method for producing a paperboard having heat-shrinkable film, comprising: a paperboard; a film capable of heat shrinking; and an adhesive layer for bonding the heat-shrinkable film to the paperboard to be heat-shrinkable The method for producing a paperboard of a film, the method for producing a paperboard having a heat shrinkable film, comprising: preparing a hot melt adhesive which can be reversibly remelted and solidified by heat to form a foamed hot melt containing bubbles a step of forming an adhesive layer on at least one of the paperboard and the heat-shrinkable film, and using the foaming hot-melt adhesive; and A bonding step of bonding the paperboard to the heat-shrinkable film described above.

The present application claims priority based on Japanese Patent Application No. 2013-9604, filed on Jan. 22, 2013, the entire disclosure of which is incorporated herein.

[Industrial availability]

The package with paperboard of the present invention is suitable for use in shrink film packaging of various articles such as cosmetics, pharmaceuticals, foods, batteries, toys, clothes, stationery, groceries, and the like.

1‧‧‧Package with cardboard

11‧‧‧Heat-shrinkable film

12‧‧‧ cardboard

14‧‧‧ hanging holes

15‧‧‧Perforation

16‧‧‧Opening

20‧‧‧ Items

21‧‧‧film packaging items

Claims (9)

A cardboard package comprising: paperboard; an article wrapped by a heat shrinkable film; and an adhesive layer bonding the heat shrinkable film to the paperboard, and the adhesive layer is heatable Further, the foamed hot-melt adhesive layer containing bubbles in the hot-melt adhesive which is melted and solidified is reversibly reversibly, and the foaming ratio of the foamed hot-melt adhesive layer obtained by the formula (1) is 1.5 or more and 5 or less, V ₁ / V ₂ ... formula (1) wherein, V ₁ of the foamed hot melt from above with the cardboard package is then recovered volume of the adhesive layer, V ₂ from above for the cardboard package having The recovered foamed hot-melt adhesive layer is heated and melted to reduce the volume after defoaming. The package with cardboard according to claim 1, wherein the hot melt adhesive has a melt viscosity of 1,000 mPa in a bubble-free state. Above s, 50,000mPa. s below. The package having a cardboard according to the first or second aspect of the invention, wherein the foaming hot-melt adhesive layer has a foaming ratio of 1.5 or more and 3 or less, which is obtained by the formula (1). ₁ / V _{2 In the} formula (1), V ₁ is the volume of the foamed hot-melt adhesive layer recovered from the package of the above-mentioned cardboard, and V ₂ is the recovered from the package of the above-mentioned cardboard. The foamed hot-melt adhesive layer is heated and melted to reduce the volume after defoaming. A package having a cardboard according to the first or second aspect of the invention, which is characterized in that, by using the above-mentioned foamed hot-melt adhesive layer, a film-wrapped article as the above-mentioned article packaged by the above-mentioned heat-shrinkable film is attached. It is formed by attaching to the above cardboard. A method for manufacturing a package having a cardboard, comprising: a paperboard; an article packaged by the heat-shrinkable film; and a foamed hot-melt adhesive layer for bonding the heat-shrinkable film to the paperboard In the method for producing a package, the method for producing a package having the paperboard includes a step of coating the article with a film capable of heat shrinkage, and thermally shrinking the heat-shrinkable film; and preparing by heat Reversibly repeating the molten and cured hot-melt adhesive, and containing the bubbles in the hot-melt adhesive, thereby forming a foaming hot-melt adhesive; using the above-mentioned foaming hot-melt adhesive, the paperboard and the above-mentioned a step of forming the foamed hot-melt adhesive layer on at least one of the heat-shrinkable film; and a bonding step of bonding the paperboard to the heat-shrinkable film via the foamed heat-fusible adhesive layer, The foaming ratio of the foaming hot-melt adhesive obtained according to the formula (2) is 1.5 or more and 5 or less, and V ₃ /V _{4 is a} formula of the formula (2), and V ₃ is not the above-mentioned hot-melt adhesive. In the state of containing bubbles A hot-melt agent per mass of 100cc, V ₄ of the foamed hot melt adhesive of the mass per 100cc. A method for manufacturing a package having a cardboard, comprising: a paperboard; an article packaged by the heat-shrinkable film; and a foamed hot-melt adhesive layer for bonding the heat-shrinkable film to the paperboard In the method for producing a package, the method for producing a package having the above-described cardboard comprises: preparing a hot-melt adhesive which can be reversibly remelted and solidified by heat, and containing bubbles in the hot-melt adhesive to form a hair a step of forming a hot-melt adhesive; a step of forming the foamed hot-melt adhesive layer on at least one of the paperboard and the heat-shrinkable film by using the foaming hot-melt adhesive; a heat-fusible adhesive layer for joining the above-mentioned paperboard to the heat-shrinkable film to obtain a bonding step of a paperboard having a heat-shrinkable film; and coating the above-mentioned article with the above-mentioned heat-shrinkable film, and a step of thermally shrinking the heat-shrinkable film to form the heat-shrinkable film, wherein the foaming hot-melt adhesive has a foaming ratio of 1.5 or more according to the formula (2). 5 or less, V ₃ /V _{4 In the} formula (2), V ₃ is the mass per 100 cc of the hot-melt adhesive in the bubble-free state of the above-mentioned hot-melt adhesive, and V ₄ is the above-mentioned foamed heat-sealing The mass per 100 cc of the agent. The method for manufacturing a package having a cardboard according to claim 5, wherein the hot melt adhesive has a melt viscosity of 1,000 mPa in a bubble-free state. Above s, 50,000mPa. s below. The method for producing a package having a cardboard according to the above aspect of the invention, wherein the foaming hot-melt adhesive has a foaming ratio of 1.5 or more and 3 or less obtained according to the formula (2). V ₃ /V _{4 In the} formula (2), V ₃ is the mass per 100 cc of the hot-melt adhesive in the bubble-free state of the above-mentioned hot-melt adhesive, and V ₄ is the above-mentioned foamed hot-melt adhesive. The quality of every 100cc. The method for producing a package having a cardboard according to the fifth or sixth aspect of the invention, wherein the molten state of the foamed hot-melt adhesive is maintained continuously The step of forming a foamed hot-melt adhesive layer; and the bonding step described above.