JP4517053B2 - Synthetic resin cup-shaped container with label and method for bonding label - Google Patents

Description

  The present invention relates to a synthetic resin cup-shaped container with a label and a method for adhering a label to an inner peripheral surface thereof.

For example, in Patent Document 1, in a synthetic resin cup container, injection molding is performed with an in-mold label attached to the cavity surface of an injection mold, and the label is adhered to the outer peripheral surface of the peripheral wall of the cup container (thermal fusion). There is a description of how to do it. In the case of injection molding, an in-mold label can be attached to the outer peripheral surface of the core mold, and the label can be heat-sealed to the inner peripheral surface of the cup container by in-mold.
JP 2002-205318 A

  On the other hand, blow-molded and thermoformed cup-shaped containers are often used for beverages, foods, etc., and the containers are particularly transparent by adhering the label to the inner peripheral surface of the cup-shaped container. In some cases, the decoration shown on the label can be shown through a transparent wall, so that an unprecedented decorative effect can be achieved. Therefore, even on blow molded products or thermoformed products, labels can be applied to the inner peripheral surface. There has been a demand for a technique for bonding.

  However, in the case of blow molded products, thermoformed products, etc., it is possible to adhere the label to the outer peripheral surface of the body portion by in-mold as in the case of injection molding, but since the core mold is not used, in-mold is applied to the inner peripheral surface. It was impossible to glue the label.

  The present invention is to meet the above-mentioned demand, and a cup-shaped container having an unprecedented decorative effect is developed with the object of developing a technique for adhering a label to the inner peripheral surface of a cup-shaped container that has been blow-molded or thermoformed. The purpose is to provide.

Of the present invention for solving the above technical problems, the means of the first invention is a transparent cup-shaped container in which a printed surface side of a label is blow-molded by thermal welding in a synthetic resin cup-shaped container with a label. It adheres to the inner peripheral surface of the main body.

The container having the above-described configuration according to the first invention is obtained by adhering a label to an inner peripheral surface by heat welding, and displays decorations such as characters, designs, and patterns printed on the label through a transparent container wall. It is possible to provide a blow-molded cup-shaped container having unprecedented decorating properties.

  In addition, a transparent adhesive layer for heat welding is used on the printed layer of the label. Both the printed layer and the adhesive layer are located between the label substrate and the wall surface of the container body without any gaps. However, since it does not directly contact the contents, it can be used for food applications.

According to a second aspect of the present invention, in the synthetic resin cup-shaped container with a label, the printed surface side of the label is bonded to the inner peripheral surface of a transparent cup-shaped container main body obtained by thermoforming the synthetic resin sheet. What you did.

The container having the above-described structure according to the second invention is obtained by adhering the label to the inner peripheral surface by heat welding, and displays decorations such as characters, designs, patterns, etc. printed on the label through a transparent container wall. It is possible to provide a thermoformed cup-shaped container having unprecedented decorating properties.

  In addition, a transparent adhesive layer for heat welding is used on the printed layer of the label. Both the printed layer and the adhesive layer are located between the label substrate and the wall surface of the container body without any gaps. However, since it does not directly contact the contents, it can be used for food applications.

According to a third aspect of the present invention , in the first or second aspect of the invention , the container body is made of polyethylene terephthalate resin.

PET resin is excellent in strength, heat resistance, and gas barrier properties by crystallizing orientation while maintaining transparency, as PET bottles are widely used as cup-shaped containers by thermoforming sheet molded products. With the above-described configuration of the third invention , it is possible to provide a blow-molded or thermo-molded cup-shaped container made of PET resin having unprecedented decorating properties.

Of the present invention for solving the above technical problem, the method of the fourth invention is:
Prepare a cup-shaped primary molded product in which the synthetic resin can be heated and shrunk in advance and molded into a large shape that is approximately similar to the final product shape,
Insert a core mold with a label on the outer peripheral surface into the primary molded product,
The primary molded article by heating, in a state sandwiching the label, to contract such that the outer adhesion-like on the surface of the core mold to adhere the label to the inner peripheral surface of the cup-shaped container, in which say.

  A synthetic resin cup-shaped container is formed by an injection molding method, blow molding method, thermoforming method from a sheet, etc., but blow molding and thermoforming are two in a molten state or a softened state (semi-molten state). Since it is the method of shape | molding while extending | stretching to axial shape, when a molded article will be in an orientation state and these molded articles are heated, it will shrink | contract.

The method of the fourth invention utilizes the heat shrinkability of the blow-molded product or thermoformed product, with the core mold having a label attached to the outer peripheral surface inserted into the primary molded product, Since the primary molded product is heat-shrinked by heating and the label is sandwiched, the outer surface of the core mold is pressed in close contact with the surface of the core mold, so even if the wall thickness of the molded product is thin, The adhesive layer can be melted or softened and adhered to the inner peripheral surface of the cup-shaped container.

  The shape of the primary molded product can be determined by the molding method of this primary molded product and the cup-shaped container that is the final molded product, that is, the core mold, but the uniformity of the thickness distribution of the final product, etc. Basically, it should be similar to the final product. Also, in order to bond the entire surface of the label so that there are no unbonded parts or wrinkles, a large shrinkage force is exerted in the shrinking process of the primary molded product, and the wall of the primary molded product sandwiches the label. It is necessary to press the core mold, and the size is selected together with the molding method of the primary molded product in consideration of the contraction force.

  And, by appropriately selecting the molding method, shape, and size of the primary molded product, a sufficient shrinkage force is exhibited, so that the label is not attached to the inner peripheral surface of the cup-shaped container or has no wrinkles. Can be easily glued. Further, the printed surface and the adhesive surface can be prevented from directly touching the contents, and there is no problem in terms of hygiene even when food is used.

  The label has a structure in which the surface of the substrate is decorated with a printed layer and has an adhesive layer thereon. However, since the printed layer is seen from the outside of the container through the body wall and adhesive layer of the container, The adhesive layer needs to be transparent. In addition, in order to fit the label on the outer peripheral surface of the core mold tightly and without slipping, a suction hole and a suction passage are formed in the core mold as necessary, and the label is vacuum-shaped on the core mold. It is preferable to suck the water.

The method of the fifth invention is that, in the method of the fourth invention , the gap between the core mold and the primary molded product is sucked and exhausted in the heat shrinking step.

By considering the shape of the final molded product by the above method of the fifth invention , the core mold and the primary molding are formed in the process of forming the suction holes and suction passages in the core mold at the necessary locations and heating and shrinking the primary molded product. By sucking and exhausting the gap between the products, the shape of the corner of the container can be sharply formed. Moreover, the adhesiveness to a core metal mold | die can be improved more, and adhesion | attachment of a label can be achieved more reliably.

The method of the sixth invention is that, in the method of the fourth or fifth invention , the primary molded product is a biaxial stretch blow molded product.

  The biaxial stretch blow molding method is a method mainly used for crystalline synthetic resins. For example, a test tubular preform is molded in advance, and the preform is stretched in the longitudinal direction in a softened state (semi-molten state). At the same time, it is a method of blow molding in the lateral direction. This molding method is stretched in a semi-molten state at a relatively low temperature, in a state where fine crystals remain, or while being generated as compared with a normal blow molding method. Contractile force can be obtained.

  In addition, the longitudinal stretch ratio and lateral stretch ratio of the primary molded product can be easily set and adjusted according to the shape of the cup-shaped container that is the final product, and the necessary shrinkage and shrinkage force can be fully exhibited in each part. The label can be securely adhered, and the shape of the cup-shaped container as the final product can be faithfully reproduced as designed, including the thickness uniformity.

According to a seventh aspect of the present invention, in the method of the fourth or fifth aspect , the primary molded article is a molded article obtained by thermoforming a sheet.

The above-mentioned method of the seventh invention is a method in which the sheet is biaxially stretched in a deep-drawn state in a softened state by forming the sheet by thermoforming the sheet, and a label is provided on the inner peripheral surface of the cup-shaped container A sufficient amount of heat shrinkage or heat shrinkage force can be obtained for bonding.

The method of the eighth invention consists in making the primary molded product made of biaxially stretched PET resin in the method of the fourth , fifth , sixth or seventh invention .

  The PET resin is a synthetic resin suitable for biaxial stretching, so that it is widely used as a so-called PET bottle by biaxial stretching blow molding or as a PET film by biaxial stretching. Thus, a sufficient amount of shrinkage and shrinkage force can be exerted in the primary molded product, and a blow-molded or thermoformed cup-shaped container having unprecedented decorating properties can be easily provided.

In the third and eighth inventions , PET is mainly used as the PET-based resin. However, as long as the essence of the PET resin is not impaired, the PET resin is mainly composed of ethylene terephthalate units and other polyester units. Polymerized polyester can be used, and for example, a resin such as nylon resin or polyethylene naphthalate resin can be blended and used in order to improve gas barrier properties and heat resistance. Examples of the component for forming the copolyester include dicarboxylic acid components such as isophthalic acid, naphthalene 2,6 dicarboxylic acid, and adipic acid, propylene glycol, 1,4 butanediol, tetramethylene glycol, neopentyl glycol, cyclohexanedimethanol, Mention may be made of glycol components such as diethylene glycol.

In addition, the container body in the third invention and the primary molded product in the eighth invention may be made of, for example, PET resin / nylon resin / in order to improve heat resistance and gas barrier properties, as long as the essence of the PET resin is not impaired. It may have an intermediate layer such as nylon resin like PET resin.

The present invention is the above-described configuration or method, and has the following effects. In the first invention , a blow-molded cup that can show decorations such as letters, designs, patterns, etc. printed on a label through a transparent container wall and has an unprecedented decoration Can be provided.

In the second invention , a thermoformed cup that can show decorations such as letters, designs, patterns, etc. printed on a label through a transparent container wall and has an unprecedented decoration Can be provided.

In the third invention , in a PET-type resin blow-molded or thermo-molded cup-shaped container having excellent strength, heat resistance, and gas barrier properties, it is printed on a label through a transparent container wall. You can show decorations such as letters, designs, patterns, etc., and you can add decorations like never before.

In the fourth invention , the heat shrinkability of the primary molded product is used, and even if the wall thickness of the molded product is thin, the label is attached to the inner peripheral surface of the cup-shaped container by the shrinkage force during heating. Can be bonded in a non-bonded part or without wrinkles.

In the fifth invention , the shape of the corner of the container can be sharply formed by sucking and exhausting the gap between the core mold and the primary molded product in the process of heating and shrinking the primary molded product. . Moreover, the adhesiveness to a core metal mold | die can be improved more, and adhesion | attachment of a label can be achieved more reliably.

In the sixth invention , since the primary molded product is a biaxial stretch blow-molded product, in a semi-molten state at a relatively low temperature, the crystallites are stretched or left while being generated. A large amount of heat shrinkage and heat yield can be obtained by heating the primary molded product.

  In addition, the longitudinal stretch ratio and lateral stretch ratio of the primary molded product can be easily set and adjusted, the necessary shrinkage amount and shrinkage force can be fully exerted in each part, the label can be securely bonded, and the wall thickness It is possible to faithfully reproduce the shape of the cup-shaped container as the final product, including the uniformity of the product, as designed.

In the seventh invention , the amount of heat shrinkage and heat shrinkage force sufficient to adhere the label to the inner peripheral surface of the cup-shaped container are obtained by making the primary molded product a molded product obtained by thermoforming the sheet. be able to.

In the eighth invention , the PET-based resin is a synthetic resin suitable for biaxial stretching, and exhibits excellent strength, heat resistance and gas barrier properties by biaxial stretching, and is sufficient for primary molded products. Thus, the label can be easily adhered to the inner peripheral surface of the cup-shaped container without any non-adhesive portion or wrinkles.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an example of a synthetic resin cup-shaped container according to the present invention, and is a perspective view partially broken away showing an example of a cup-shaped container. The container main body 1 is made of PET resin, has a transparency, has a bottomed cylindrical shape with a diameter slightly increased upward, and has a flange 3 at the upper end. The label 6 is adhered to the inner peripheral surface over the entire circumference and substantially the entire height.

  The label 6 has a three-layer structure having a printed layer 6b on a substrate 6a and a transparent adhesive layer 6c thereon (see a partially enlarged view in FIG. 1), and is labeled via a transparent body wall 4w. 6 is decorated with characters, designs, patterns, etc. (designed characters “AB” in FIG. 1), so that it has an unprecedented decoration. As the base material 6a, a polypropylene resin film, a PET resin film, a synthetic paper made of a synthetic resin and an inorganic filler can be used, and as the adhesive layer, for example, a low density polyethylene resin, an ethylene-vinyl acetate copolymer, etc. The hot melt type can be used.

  FIG. 2 is one example of the label adhering method of the present invention, and is an explanatory view showing an outline of the method for adhering the label 6 in the labeled cup-shaped container of FIG. FIG. 2A shows a state in which the primary molded product 2 is inverted and installed on the base 13 of the jig 1. In this state, the core mold 12 is erected in an inserted state inside the primary molded product 2. The shape of the core mold 12 determines the shape of the container main body 1 of the cup-shaped container which is the final product. The shape of the core mold 12 is substantially inscribed in the inner surface of the body 4 and the bottom 5 of the container main body 1. It is a cylindrical shape with a slightly reduced diameter.

  A label 6 is externally attached to the side peripheral surface of the core mold 12 in a close-contact manner over the entire circumference and the entire height. In order to improve the adhesion to the label 6, a suction path 14 is formed in the jig 11 as shown by a dotted line in the drawing, a suction hole 14 a is opened on the side peripheral surface, and a core mold 12 is formed by a vacuum pump or the like. And the label 6 are preferably evacuated. Note that the suction path 14 and the suction holes 14a in FIG. 2 (a) are very schematically drawn, and in actuality, a large number of small circular or slit-shaped holes are provided as necessary.

  On the other hand, the primary molded product 2 is a biaxial stretch blow molded product made of PET resin, and is obtained by biaxial stretch blow molding from a small preform at a resin temperature of 80 to 120 ° C. The shape of the primary molded product 2 is a cup shape that is substantially similar to the shape of the container body 1, and is about 1.1 to 1.2 times larger than the container body 1 both vertically and horizontally.

  In this manner, in a state where the primary molded product 2 and the jig 11 are disposed, they are placed in a heating furnace adjusted to a temperature of 160 to 180 ° C. and heated for about 20 to 30 seconds. FIG. 2 (b) shows a state when taken out from the heating furnace, and the primary molded product 2 contracts and is in a close contact state along the core mold 12 with the label 6 interposed therebetween. FIG. 2C shows a state in which the cup-shaped container as the final product is removed from the core mold 12 after cooling, and the label 6 is not wrinkled on the inner peripheral surface of the container body 1 by the adhesive layer 6c. Also, it can be adhered exactly without shifting (see FIG. 1).

  Further, since the primary molded product 2 has a sufficient amount of shrinkage and shrinkage due to heating, for example, the shape of the corner 7 from the body 4 to the bottom 5 of the container body 1 is sharp along the shape of the core mold 12. It can be formed into a shape. If necessary, by forming the suction passage 15 and the suction hole 15a in the jig 1 at the required place as schematically shown by the dotted lines in FIGS. It becomes possible to form the edge of the part 7 etc. sharply.

  The method of the present invention is not limited to the example of the embodiment described above. For example, the shape of the container body 1 can be not only cylindrical but also, for example, a polygonal cylindrical shape, and the label 6 can be partially disposed on the peripheral wall of the trunk 4, not limited to PET resin, polyethylene, Synthetic resins conventionally used for cup-shaped containers, such as polypropylene and polystyrene resins, can be used. The molding method of the primary molded product 2 is not limited to the biaxial stretch blow molding, and a molded product by a thermoforming method, a normal blow molding method, or the like can also be used.

  The label 6 can have various layer configurations depending on the purpose as long as the printed layer 6b can be seen through the container wall. For example, the gas barrier property of the container wall can be improved by laminating a film having a gas barrier property on the substrate 6a or by using an aluminum laminate film.

  Moreover, it can also be set as a layer structure like OPP (base material 6a) / printing layer 6b / silica vapor deposition PET film / PET sealant (6c), for example. In this configuration, a transparent silica-deposited PET film layer having a high gas barrier property is formed on the printed layer 6b, and a transparent PET sealant layer is further formed thereon as the adhesive layer 6c. In addition, OPP points out the oriented film made from a polypropylene resin here.

As described above, the cup-shaped container made of a synthetic resin with a label and the method for adhering the label of the present invention can easily provide a cup-shaped container having a label adhered to the inner peripheral surface, through a transparent container wall. Can display decorations such as letters, designs and patterns printed on labels, and can provide blow-molded or thermoformed cup-shaped containers with unprecedented decoration, food containers, etc. Is expected to be widely applicable and deployable.

It is a perspective view which partially fractures | ruptures and shows one Example of the synthetic resin cup-shaped containers of this invention. It is explanatory drawing which shows the outline | summary about one Example of the label adhesion method of this invention.

DESCRIPTION OF SYMBOLS 1; Container main body 2; Primary molded product 3; Flange 4, 4a; Body part 4w; Body wall 5, 5b; Bottom part 6; Label 6a; Base material 6b; Print layer 6c; 12; Core mold 13; Base part 14; Suction passage 14a; Suction hole 15; Suction passage 15a; Suction hole

Claims (7)

A synthetic resin cup-shaped container with a label, wherein the printed surface side of the label (6) is bonded to the inner peripheral surface of a blown transparent cup-shaped container body (1) by heat welding. Labeled synthetic resin cup-shaped container according to claim 1, wherein the container body (1) and polyethylene terephthalate-based resin. Prepare a cup-shaped primary molded product (2) that can be heat-shrinkable in advance and molded into a large shape that is substantially similar to the final product shape, and inside the primary molded product (2), Insert the core mold (12) with the label (6) attached to the outer peripheral surface, and heat the primary molded product (2) with the label (6) sandwiched between the surface of the core mold (12) A method for adhering a label to a cup-shaped container, wherein the label (6) is adhered to the inner peripheral surface of the cup-shaped container by being contracted so as to be closely attached to the outer surface. The method for adhering a label to a cup-shaped container according to claim 3 , wherein the gap between the core mold (12) and the primary molded product (2) is sucked and exhausted in the heat shrinking step. The method for adhering a label to a cup-shaped container according to claim 3 or 4, wherein the primary molded product (2) is a biaxial stretch blow molded product. The method for adhering a label to a cup-shaped container according to claim 3 or 4, wherein the primary molded product (2) is a molded product obtained by thermoforming a synthetic resin sheet. The method for adhering a label to a cup-shaped container according to claim 3, 4, 5, or 6, wherein the primary molded product (2) is made of a polyethylene terephthalate resin biaxially stretched.

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