JP6349656B2 - Method for manufacturing an insulating container - Google Patents

Description

The present invention relates to a method of manufacturing a heat-insulating container for imparting heat insulating property by foaming a foaming resin layer included in the wall of the container.

  As a heat-insulating container, a heat-insulating container including a foamed resin layer obtained by adding a thermally foamable organic foaming agent to a polyolefin resin is known (see, for example, Patent Document 1).

JP 2001-278363 A

  In the heat insulating container described in Patent Document 1, since the foamed resin layer is directly laminated on the base material mainly made of paper, it is difficult to fix to the base material mainly made of paper due to the property of the foamed resin layer. There is a risk. Further, this heat insulating container is not suitable for food because the foamed resin layer contains an organic foaming agent.

Accordingly, an object of the present invention the fixing of the paper mainly the substrate and the foamed resin layer is to provide a method for manufacturing a heat-insulating container which is suitable for good food.

Hereinafter, a method for manufacturing the heat-insulating container of the present invention. In order to facilitate understanding of the present invention, reference numerals in the accompanying drawings are appended in parentheses, but the present invention is not limited to the illustrated embodiment.

In the production method of the present invention, a base material (11) mainly composed of paper, an adhesive resin layer (12), and a foamed resin layer (13) kneaded with sodium hydrogen carbonate are laminated in order, and A step of forming a laminated material (20) provided with a barrier coat layer between a base material and the adhesive resin layer (FIGS. 3A and 3B) and the laminated material contain contents. So that the walls (2, 3) partitioning the interior and the exterior of the substrate, and the base material, the adhesive resin layer, and the foamed resin layer are sequentially arranged from the exterior side toward the interior side A step of forming the laminated material into a predetermined container shape (FIG. 3C) and a step of applying heat to the laminated material formed into the container shape to foam the foamable resin layer (FIG. 3E). And a water-soluble ethylene-vinyl alcohol as a constituent material of the barrier coat layer. Lumpur copolymer resin is selected, and is intended to form the barrier coating layer by coating the ethylene-vinyl alcohol copolymer resin on the surface of the substrate.

According to this manufacturing method, since the foamed resin layer is foamed after the laminated material is molded into a predetermined container shape, compared with the case where the foamed resin layer is foamed, the container shape is molded. It becomes easy. That is, the same method as the manufacturing method of the container without the foamed resin layer can be used. Moreover, according to the manufactured heat insulating container, since the adhesive resin layer is interposed between the foamed resin layer and the base material, the foamable resin layer and the base material can be used regardless of the properties of the foamable resin layer. Adhered securely. Thereby, the fixability of the base material mainly made of paper and the foamed resin layer is improved. Further, since the foamable resin layer is formed by kneading sodium hydrogen carbonate, the foaming agent is uniformly distributed in the resin as compared with the case where sodium hydrogen carbonate as a foaming agent is added to the resin. Thereby, since a foamed resin layer foams uniformly, the stable heat insulation effect can be acquired. Furthermore, since the foamed resin layer is located on the inner side with respect to the base material, there is no possibility that the surface of the base material will be rough even if the foamed resin layer is foamed. Therefore, it is not necessary to provide a layer that smooths the container surface in order to improve the printing state of the container surface, so that the manufacturing man-hours and use compared to the case where the foamed resin layer is located on the outer side with respect to the base material Material can be reduced. Moreover, since sodium hydrogen carbonate is used as a foaming agent contained in the foamed resin layer, the heat-insulating container can be used without problems for food, and the foaming resin layer has a relatively low foaming temperature, so that the foamed resin layer is foamed. The amount of heat required can be reduced. Moreover, not only the heat insulation is obtained when the foamed resin layer is foamed, but the foamed foamed resin layer can also be expected to have a function as a permeation suppression layer that suppresses permeation of water vapor. The barrier coat layer can suppress transfer fragrance from the substrate side to the contents.

  As described above, according to the heat insulating container of the present invention, since the adhesive resin layer is interposed between the foamed resin layer and the base material, the fixing property between the base material mainly made of paper and the foamed resin layer is improved. improves. Moreover, since the foamed resin layer is located on the inner side with respect to the base material, there is no possibility that the surface of the base material is rough even if the foamed resin layer is foamed. Therefore, it is not necessary to provide a layer for smoothing the surface of the container in order to improve the printed state of the container surface, so that the number of manufacturing steps and materials used can be reduced. Further, according to the manufacturing method of the present invention, the foamed resin layer is foamed after the laminated material is molded into a predetermined container shape. Therefore, the container shape is compared with the case where the foamed resin layer is molded into the container shape after foaming. It becomes easy to form.

The perspective view which cut away and showed the heat insulating container which concerns on one form of this invention. The elements on larger scale which expanded and showed the II section of FIG. The figure which showed an example of the manufacturing method. The elements on larger scale of the cross section of the heat insulation container which concern on a 2nd form. The partial expanded view of the cross section of the heat insulation container which concerns on a 3rd form. The partial expanded view of the cross section of the heat insulation container which concerns on a 4th form.

(First form)
As shown in FIG. 1, a paper cup 1 as a heat-insulating container has a cylindrical body portion 2 whose diameter gradually increases toward an opening, and a bottom portion 3 provided at the lower end of the body portion 2. Yes. Each of the trunk | drum 2 and the bottom part 3 has divided the inside for accommodating the contents, and the exterior. Therefore, each of the trunk | drum 2 and the bottom part 3 is equivalent to the wall part of this invention. The body portion 2 is provided with a top curl portion 4 whose upper end is rounded outward.

  As shown in FIG. 2, the laminated material 10 that is a material of the body portion 2 and the bottom portion 3 is configured in a thin plate shape, and is bonded to a base material 11 mainly composed of paper from the outside to the inside. The resin layer 12 and the foamed resin layer 13 are laminated in order. Furthermore, a polyethylene layer 14 as an inner covering layer is laminated on the inner side of the foamed resin layer 13. The polyethylene layer 14 is made of low density polyethylene. The thickness of the polyethylene layer 14 is set to 20 μm, for example. Since the surface of the container is not roughened even if the foamed resin layer 13 is foamed, the printed layer 15 on which predetermined characters and pictures are expressed is provided on the outer side of the base material 11 without interposing a layer that smoothes the surface. be able to.

  Various types of paper can be used as the paper for the base material 11. For example, cup base paper, synthetic paper, clay coated paper, craft paper, or the like can be used as the material of the base material 11. In the illustrated example, the thickness of the base material 11 is set to 280 μm, for example. The adhesive resin layer 12 is made of ethylene vinyl acetate copolymer (EVA), and the thickness thereof is appropriately set.

  The foamed resin layer 13 is composed of a material in which the distribution of the thermal foaming agent is made uniform by kneading sodium bicarbonate, which is a thermal foaming agent, into the polyolefin resin. Examples of the polyolefin resin include low density polyethylene, medium density polyethylene, metallocenecene polyethylene, and polypropylene. The thickness of the foamed resin layer 13 is set to 60 μm, for example. Moreover, as melting | fusing point of resin, it is preferable at 110 to 190 degreeC. If it is lower than 110 ° C., the adhesiveness to the substrate is deteriorated, and if it exceeds 190 ° C., the thermal foaming agent may foam at the time of extrusion. More preferably, 120 degreeC-150 degreeC is preferable. As is well known, sodium bicarbonate has a property of foaming when heated. Therefore, as will be described later, the heat insulation layer is formed by foaming the foamed resin layer 13 by applying heat to the paper cup 1 after molding. Thereby, heat insulation is provided to the paper cup 1.

  Next, a method for manufacturing the paper cup 1 will be described with reference to FIG. First, in the step (a), a base material 11 mainly composed of paper is prepared. Next, in step (b), the constituent materials of the adhesive resin layer 12, the foamed resin layer 13, and the polyethylene layer 14 are extruded and laminated at one time, and the layers 12, 13, and 14 are laminated on the base material 11. Thereby, the laminated material 10 is obtained. Each constituent material of the adhesive resin layer 12, the foamed resin layer 13, and the polyethylene layer 14 has a melting point lower than the foaming start temperature of sodium hydrogen carbonate contained in the foamed resin layer 13. For this reason, extrusion at a temperature lower than the foaming start temperature of sodium hydrogen carbonate is possible. Thereby, foaming of the foamed resin layer 13 is suppressed in the step (b). In addition, the foaming start temperature of the sodium hydrogencarbonate contained in the foamed resin layer 13 is set in a range of 150 ° C. to 200 ° C.

  In the step (c), the laminated material 10 obtained in the step (b) is formed into a cup shape which is a predetermined container shape by a known method. That is, from the laminated material 10 obtained in the step (b), a fan-shaped body blank 2 ′ serving as a material for the body 2 and a bottom blank 3 ′ serving as a material for the bottom 3 are cut. Next, the body blank 2 'is rolled into a cylindrical shape and both ends are bonded together to form the body pasting part 5 (see also FIG. 1). On the other hand, the bottom blank 3 'is subjected to a molding process in which the outer peripheral edge is bent downward. Next, a molded bottom blank 3 ′ is disposed below the body blank 2 ′ processed into a cylindrical shape. And the lower end part of trunk | drum blank 2 'is bent so that the bending part of bottom blank 3' may be wrapped in the lower end part of trunk | drum blank 2 '. While maintaining this state, the portion where the bent portion of the bottom blank 3 ′ and the lower end of the body blank 2 ′ overlap is heated and integrated with pressure. Thereafter, the top curl portion 4 is formed on the upper end portion of the body portion 2 by a well-known method, whereby a pre-heat treatment cup 1 ′ formed into a cup shape is obtained. Note that a material different from the laminated material 10 may be used as the material of the bottom blank 3 ′.

  In the step (d), a predetermined printing is performed on the pre-heat treatment cup 1 ′ obtained in the step (c) to form the printed layer 15. Next, in step (e), the pre-heat treatment cup 1 ′ is placed in a heating furnace (not shown), and the pre-heat treatment cup 1 ′ is heated by the heater H provided in the heating furnace to foam the foamed resin layer 13. Let Thereby, the paper cup 1 shown in FIG. 1 is obtained. In addition, heating conditions, such as the temperature conditions and heating time in a process (e), are set suitably. Moreover, you may change the heat source in a process (e) suitably.

  According to the manufacturing method shown in FIG. 3, since the foamed resin layer 13 is foamed after the laminated material 10 is molded into a cup shape, the cup is compared with the case where the foamed resin layer 13 is molded into a cup shape after foaming. Molding into a shape becomes easy. That is, the same well-known method as the manufacturing method of the paper cup without the foamed resin layer 13 can be used.

  According to the paper cup 1, since the adhesive resin layer 12 is interposed between the foamed resin layer 13 and the base material 11, the foamable resin layer 13 and the base material 11 can be used regardless of the properties of the foamable resin layer 13. Adhered securely. Thereby, the fixability of the base material 11 mainly composed of paper and the foamed resin layer 13 is improved. In addition, since the foamable resin layer 13 is formed by kneading sodium hydrogen carbonate, the foaming agent is uniformly distributed in the resin as compared with the case where sodium hydrogen carbonate as a foaming agent is added to the resin. Thereby, since the foamed resin layer 13 foams uniformly, the stable heat insulation effect can be acquired. Moreover, since the foamed resin layer 13 is located on the inner side with respect to the base material 11, there is no possibility that the surface of the base material is roughened even if the foamed resin layer 13 is foamed. Therefore, it is not necessary to provide a layer for smoothing the surface of the container in order to improve the printed state of the container surface, so that the number of manufacturing steps and materials used can be reduced. Further, since sodium hydrogen carbonate is used as a foaming agent contained in the foamed resin layer 13, the paper cup 1 can be used without problems for foods and the foaming resin layer 13 is foamed because the foaming start temperature is relatively low. Can reduce the amount of heat required. Furthermore, not only can the heat insulation be obtained when the foamed resin layer 13 is foamed, the foamed foamed resin layer 13 can also be expected to function as a permeation suppression layer that suppresses the permeation of water vapor.

(Second form)
Next, a second embodiment of the present invention will be described with reference to FIG. This embodiment is characterized in that a barrier coat layer is provided on a substrate. Since the other configuration is the same as that of the first embodiment, the same reference numerals are attached to FIG. 4 to omit or simplify the overlapping description. As shown in FIG. 4, the paper cup as the heat-insulating container of the present embodiment uses a laminated material 20 as a material for the body portion 2 and the bottom portion 3 that are wall portions. The base material 11 is provided with a barrier coat layer 11 a on the side where the adhesive resin layer 13 is laminated, in other words, between the base material 11 and the adhesive resin layer 12. As the constituent material of the barrier coat layer 11a, a material having a function of suppressing the transmission of odorous components, for example, a water-soluble ethylene / vinyl alcohol copolymer resin (EVOH) is selected. The barrier coat layer 11a is formed by applying EVOH to the surface of the substrate 11. The step of forming the barrier coat layer 11a can be provided between step (a) and step (b) in FIG. In addition, about the other component of the laminated material 20, it laminates | stacks by the method similar to the manufacturing method demonstrated in the 1st form. The paper cup of this embodiment is manufactured through the steps (c) to (e) of FIG.

  According to the paper cup in which the wall portion is configured by the laminated material 20, in addition to obtaining the same effect as that of the first embodiment, the barrier coat layer 11a provided on the base material 11 allows the content from the base material 11 side to the contents. Can suppress migratory incense.

(Third form)
Next, a third embodiment of the present invention will be described with reference to FIG. This embodiment is characterized by the configuration of the inner coating layer laminated on the inner side of the foamed resin layer. Since the other configuration is the same as that of the first embodiment, the same reference numerals are assigned to FIG. 5 to omit or simplify the overlapping description. As shown in FIG. 5, the paper cup as the heat-insulating container of this embodiment uses a laminated material 30 as a material for the body 2 and the bottom 3 that are walls. The laminated material 30 has a medium density polyethylene layer 31 as an inner coating layer laminated on the inner side with respect to the foamed resin layer 13. The medium density polyethylene layer 31 is made of medium density polyethylene, and its thickness is set to 40 μm, for example. The medium density polyethylene layer 31 is formed by extruding and laminating together with the adhesive resin layer 12 and the foamed resin layer 13 as in the step (b) of FIG. The paper cup of this embodiment is manufactured through steps (c) to (e) of FIG. 3 using the laminated material 30 as a raw material.

  According to the paper cup in which the wall portion is configured by the laminated material 30, in addition to obtaining the same effect as the first embodiment, the medium density polyethylene layer 31 has an effect of suppressing permeation of water vapor from the inside to the base material 11 side. Can be increased.

(4th form)
Next, a fourth embodiment of the present invention will be described with reference to FIG. This embodiment is characterized by the configuration of the inner coating layer laminated on the inner side of the foamed resin layer. Since the other configuration is the same as that of the second embodiment, the same reference numerals are attached to FIG. 6 to omit or simplify the overlapping description. As shown in FIG. 6, the paper cup as the heat-insulating container of the present embodiment uses a laminated material 40 as a material for the body portion 2 and the bottom portion 3 that are wall portions. In the laminated material 40, a medium density polyethylene layer 41 and a polyethylene layer 42 are sequentially laminated on the foamed resin layer 13 from the outside to the inside. That is, the inner coating layer according to this embodiment has a multilayer structure in which these layers 41 and 42 are laminated. The medium density polyethylene layer 41 is made of medium density polyethylene, and the polyethylene layer 42 is made of low density polyethylene. The thickness of the medium density polyethylene layer 41 is set to 20 μm, for example, and the thickness of the polyethylene terephthalate layer 42 is set to 20 μm, for example. The medium density polyethylene layer 41 and the polyethylene layer 42 are formed by extruding and laminating at once with the adhesive resin layer 12 and the foamed resin layer 13 as in the step (b) of FIG. The paper cup of this embodiment is manufactured through the steps (c) to (e) of FIG.

  According to the paper cup in which the wall portion is configured by the laminated material 40, in addition to obtaining the same effect as the first embodiment, the medium density polyethylene layer 41 has an effect of suppressing the permeation of water vapor from the inside to the base material 11 side. Is improved, and the transfer fragrance from the substrate 11 side to the contents can be suppressed by the barrier coat layer 11 a provided on the substrate 11.

The present invention is not limited to the above embodiments, and may be implemented in various forms . Upper Symbol respective embodiments, the shape of the is a thermally insulating container cup shaped shown is only an example. The present invention can be applied to, for example, a tray-shaped container as long as the container has a wall portion that partitions the inside and the outside.

1 Paper cup (insulating container)
2 trunk (wall)
3 Bottom (wall)
DESCRIPTION OF SYMBOLS 10 Laminated material 11 Base material 11a Barrier coat layer 12 Adhesive resin layer 13 Foamed resin layer 14 Polyethylene layer (inner coating layer)
20 Laminated material 30 Laminated material 31 Medium density polyethylene layer (inner covering layer)
40 Laminate 41 Medium density polyethylene layer 42 Polyethylene layer

Claims (1)

A base material mainly composed of paper, an adhesive resin layer, and a foamed resin layer kneaded with sodium hydrogen carbonate are sequentially laminated, and a barrier coat layer is provided between the base material and the adhesive resin layer. Forming the provided laminated material; and
The laminated material becomes a wall part that separates the inside and the outside for containing contents, and the base material, the adhesive resin layer, and the foamed resin layer are sequentially arranged from the outside side toward the inside side Forming the laminated material into a predetermined container shape,
A step of applying heat to the laminated material formed into the container shape to foam the foamable resin layer,
A water-soluble ethylene / vinyl alcohol copolymer resin is selected as a constituent material of the barrier coat layer, and the barrier coat layer is formed by applying the ethylene / vinyl alcohol copolymer resin to the surface of the substrate. A method for producing a heat-insulating container.

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