JPH0744581Y2 - Paper container with vertical sealing tape - Google Patents

Description

[Detailed Description of the Invention] (Industrial field of application) The present invention provides the above-mentioned stacking part for sealing the edge stacking part of the paper container and concealing the end of the paperboard material exposed on the inner surface of the paper container. On the other hand, the present invention relates to a paper container in which a vertical seal tape is attached from the inner surface of the paper container.

(Prior Art) Conventionally, as a structure of a vertical sealing tape, a heat-fusible resin such as polyethylene is used for the outermost layer, but there are various core layers, which are described in Japanese Patent Publication No. 56-14544. Is a core layer of polyamide or aluminum foil, Japanese Utility Model Publication No. 61-16989,
Japanese Utility Model Publication No. 61-7127 proposes a vertical seal tape using a core layer of polyvinylidene chloride-coated polyester.

(Problems to be solved by the invention) The tape proposed above uses a material having a high softening temperature or a material which is difficult to soften in the core layer, so that the tape thermally fuses the edges of the paperboard material. Even if the vertical seal portion is heat-sealed by the heating temperature at that time, it is not deformed or damaged.

However, in the overlapping part of the edges of the paperboard material,
When the vertical sealing tape heated and melted by the heater is pasted from above so as to straddle this stepped portion, it becomes the lower side due to the rigidity of the tape because there is a stepped portion corresponding to the thickness of the paperboard material. There is a drawback in that it is difficult to make surface contact with the edge surface of the paperboard material, which makes it difficult to obtain a uniform sealing surface.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems, and to provide a paper container with a vertical sealing tape, which has good workability and finish, and can achieve perfect sealing.

(Means for Solving the Problems) A paper container with a vertical sealing tape according to the present invention is a paper-based paper container with a heat-bonding synthetic resin as the outermost layer on both the inner and outer surfaces of the paper board material in the width direction. By stacking in a tubular shape and heat-adhering, assuming that it is a paper container molded through a step of forming a vertical seal portion, the core layer has a core layer as a vertical seal tape to be attached to the inside of the vertical seal portion. It is characterized by using a non-crystalline polyethylene terephthalate and a seal tape having a laminated structure of three or more layers in which the outermost layers on both front and back surfaces are formed of a heat-fusible synthetic resin.

Amorphous polyethylene terephthalate that forms the core layer is obtained by substituting a part of polyethylene terephthalate with other components and performing random copolymerization so that the crystallization temperature is infinitely small and the amorphous state is always maintained. Is. As the monomer used for the substitution, 2,6-naphthalenedicarboxylic acid, paraphenylenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid, polyvalent carboxylic acid such as trimellitic acid, ethylene glycol, 1,2-propylene glycol, 1,4-butadiol,
Neopentyl glycol, diethylene glycol, 1,4
Examples thereof include polyhydric alcohols such as cyclohexanedimethanol and trimethylolpropane.
Of these, monomers having a ring structure such as neopentyl glycol, 1,4-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedimethanol are more glass transitions of the copolymer as the amount of such monomer components increases. It is particularly preferable because it has a property of increasing points and is easy to prepare. The glass transition point of the non-crystalline polyethylene terephthalate used in the present invention is preferably 60 ° C. or higher, particularly 75 ° C. or higher in view of the balance between softening during sealing and rigidity at other times.

(Function) Since the core layer of the vertical sealing tape used in the present invention is made of amorphous polyethylene terephthalate, the softening temperature is lower than that of the conventional crystalline polyethylene terephthalate. When this sealing tape is pasted on the overlapping portions of the parts and heat-sealed, when the resin on the front and back surfaces such as polyethylene formed for the purpose of heat-sealing softens, the core layer also softens at the same time. Therefore, even in the overlapping portion where the rigidity is lost and there is a step, the surface can be contacted across both of them. as a result,
The vertical sealing tape can form a uniform adhesive surface on both surfaces of the overlapping portion.

On the other hand, since non-crystalline polyethylene terephthalate has an excellent barrier property against gas permeation and water vapor permeation, it can sufficiently complement the barrier properties of the front and back layers such as polyethylene.

(Example) Hereinafter, the present invention will be described with reference to an example.

First, FIG. 1 is a perspective view showing a vertical seal tape bonding portion with a paper container according to an embodiment of the present invention partially cut away to show an exaggerated thickness. In the figure, the paperboard material 20 is paper
A thermoplastic resin layer 22, 23 typified by polyethylene is laminated on the outermost layers on the front and back sides of 21 as a base, and edges thereof are vertically overlapped to form a seam 24. The vertical seal tape 10 is adhered to the seam 24 from the inner surface side.

A manufacturing example of such a paper container will be described in detail below.

Making vertical sealing tape As a non-crystalline polyethylene terephthalate, Eastman Kodak KODAR PETG6763 (glass transition point 81
° C. Uses 1,4-cyclohexanedimethanol as a copolymer component. ) Was used as a core layer of non-crystalline polyethylene terephthalate, and a heat-bonding layer of polyethylene was laminated on the front and back surfaces of the core layer to form a three-layer structure sheet. Further, from this sheet, a longitudinal sealing tape having a width of 7.5 mm, that is, as shown in FIG.
3 of terephthalate 11 and polyethylene 12 and 13 on the front and back layers
A vertical seal tape having a layer structure was prepared. The vertical sealing tape has a total thickness of 40 μm for the core layer and 30 μm for each of the front and back layers.
It is 100 μm.

Adhesion of Paperboard Material for Paper Container to One Edge Next, based on FIG. 2, the vertical seal tape obtained as described above is applied in the width direction of the belt-shaped paperboard material before forming the paper container. The process of heat bonding to one edge will be described.

The vertical sealing tape 10 is supplied from the winding 15, while the paperboard material 20 is supplied from the winding 15. Hot air generated from the hot air blowing device 23 is applied to the edge of the paperboard material 20 on which the vertical seal tape 10 is attached, and the heated polyethylene in the surface layer is melted. About half of the widthwise direction of the vertical seal tape 10 is superposed on the melted portion, and is nipped and pressed by a pair of pressure rolls 24, resulting in the paperboard material 20 and the vertical seal tape 10.
Both surface polyethylenes are adhered so that they melt each other.

Cylindrical molding As described above, the paperboard material 20 with the vertical sealing tape 10 adhered to one edge is formed into a cylinder by stacking both edges of the paperboard material 20 on each other as shown in the perspective view of FIG. The vertical sealing tape 10 is adhered to the paperboard material 20 at the same time as forming and adhering the overlapping portion. At the time of this adhesion, the polyethylene of the surface layer of the edge portion of the vertical seal tape 10 on the non-adhered side is melted by the hot air blowing device 28, and the melted polyethylene is already melted on the edge portion of the vertical seal tape 10. It is adhered to the outer surface of the vertical seal tape (10) and the unfused portion of the vertical seal tape (10), and is sandwiched and crimped by a pair of crimp rolls (29).

At this time, since the core layer of the vertical sealing tape 10 is softened, the vertical sealing tape 10 can be surface-adhered satisfactorily despite the step difference of the joint due to the thickness of the paperboard material 20.

The vertical seal tape 10 is used by folding the inner edge of the paperboard material 20 from the inner surface to the outer surface so as to cover the end portion of the paperboard material 20 in two folds. It may be used so that the other edge is heat-sealed. Also in this case, since the core layer of the vertical sealing tape 10 is soft,
It can withstand deformation such as folding in half.

Filling of Contents, Horizontal Sealing, and Molding The tubular paperboard material 20 is laterally sealed at the bottom and top at predetermined intervals to form a sealed container. That is, after the bottom portion is laterally sealed, the contents are filled, and after the top portion is laterally sealed to divide each container, it is separated from the band-shaped connection. Subsequently, the product is shaped into a brick and becomes a product, but it is not particularly necessary that the vertical and horizontal relations of the seals in the paper container manufacturing cross-sectional view match the vertical and horizontal relations of the final product.

(Effect of the Invention) In the present invention, since the core layer of the vertical sealing tape is formed of amorphous polyethylene terephthalate, the adhesive surface is made uniform despite the step difference between the overlapping edges of the paperboard material. Can be finished. In addition, since non-crystalline polyethylene terephthalate has an excellent barrier property against gas permeation and water vapor permeation, the paper container using this vertical sealing tape can obtain extremely excellent sealing property.

[Brief description of drawings]

FIG. 1 is a perspective view of a paper container according to the present invention with a part cut away, FIG. 2 is a perspective view showing a step of adhering a vertical sealing tape to one edge of a paperboard material, and FIG. 3 is a tubular shape. It is a perspective view which shows the process of shape | molding. 10 …… Vertical seal tape, 11 …… Core layer, 20 …… Paperboard material.

Claims (2)

[Scope of utility model registration request] 1. A vertical seal portion is formed by stacking heat-adhesive synthetic resin on the front and back sides of a paper base material in the form of strips, and stacking the two edges in the width direction in a tubular shape, followed by heat bonding. A paper container molded through a forming step, wherein the core layer is an amorphous polyethylene terephthalate core from the inner surface side of the vertical seal portion, and the outermost layers on the front and back sides are heat-meltable synthetic resins. A paper container with a vertical seal tape, wherein the seal tape having a laminated structure of three or more layers formed in 1. is laminated. 2. The paper container according to claim 1, wherein the glass transition point of the non-crystalline polyethylene terephthalate is 75 ° C. or higher.