JP2021054431A - Storage container and storage container group - Google Patents

Abstract

To provide a storage container and a storage container group that suppress blocking.SOLUTION: A storage container 11 is taken out from a storage container group obtained by hot press molding of a plurality of sheet-shaped members including a base material layer 15 composed of paper material and a polybutylene terephthalate (PBT) resin layer 16 stacked above the base material layer 15 in an overlapped state. The storage container 11 includes the base material layer 15 composed of the paper material and the polybutylene terephthalate (PBT) resin layer 16 stacked above the base material layer 15. A basis weight of the base material layer 15 is between 20 g/m2 and 100 g/m2, a thickness of the PBT resin layer 16 is between 5 μm and 30 μm, and a crystallinity index of the PBT resin layer 16 is 9.0% or higher. Therefore, an event of occurring blocking on whole circumference in a circumferential direction between the stacked storage containers can be prevented, so it becomes easy to take out and use at the time of use.SELECTED DRAWING: Figure 2

Description

The present invention relates to a storage container group in which a storage container and a plurality of storage containers are laminated, and more particularly to a storage container made of a sheet-like member and a storage container group in which a plurality of storage containers are laminated.

Conventionally, a container made of a sheet-like member in which a PBT resin film is laminated on paper, having a bottom portion and a peripheral wall portion and having an open upper surface, is widely used, for example, for storing food. Some such storage containers have an open top, a bottom, and a peripheral wall that rises from the periphery of the bottom and is formed in a fold shape. For example, food such as side dishes is divided into small pieces in a lunch box. It is used for storage and other purposes.

Further, in order to improve manufacturing efficiency, for example, as in Patent Document 1, a technique is known in which a plurality of storage containers are integrally formed by hot press molding in a state where a plurality of sheet-shaped objects to be molded are stacked. ing. A plurality of storage containers (storage container group) manufactured by such an integrated forming technique are stored in a plastic molded container and supplied to the market.

Then, at the time of use, the user takes out the required number from the storage container group stored in the plastic molded container and uses it.

Japanese Unexamined Patent Publication No. 2000-93296

FIG. 5 is a schematic view showing blocking of a conventional storage container group. However, with reference to the figure, conventionally, it has been known that a phenomenon in which adjacent upper and lower storage containers are attracted to each other (hereinafter referred to as “blocking”) occurs when forming a storage container group. As shown in the figure, a blocking generating portion 150 is generated between the first storage container 111 and the second storage container 112 adjacent thereto, and the first storage container 111 and the second storage container are generated. There was a case where 112 and 112 were stuck. Further, when this blocking occurs, the user may not be able to take out the storage container smoothly, or at the time of taking out, a part of one of the upper and lower storage containers may be peeled off and remain in the other storage container. It was.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a storage container and a storage container group in which blocking is suppressed.

Inventor's diligent research has found that the occurrence of blocking correlates with the crystallinity of the PBT resin.

Therefore, in order to achieve the above object, the invention according to claim 1 is a storage container taken out from a storage container group obtained by hot press molding in a state where a plurality of sheet-shaped members are stacked. The storage container is composed of a base material layer made of a paper material and a polybutylene terephthalate (PBT) resin layer laminated on at least one of the base material layers, and the basis weight of the base material layer is 20 g / m ² to. It is 100 g / m ² , the thickness of the PBT resin layer is 5 μm to 30 μm, and the crystallinity of the PBT resin layer is 9.0% or more.

With this configuration, it is possible to prevent an event in which blocking occurs over the entire circumference in the circumferential direction between the stacked storage containers.

The invention according to claim 2 has a crystallinity of 11.5% or more in the PBT resin layer in the configuration of the invention according to claim 1.

With such a configuration, it is also possible to prevent blocking from occurring in a range of less than 1/4 in the circumferential direction between the stacked storage containers.

The invention according to claim 3 is the ratio of the basis weight of the base material layer to the thickness of the PBT resin layer (basis weight g / m ² ÷ PBT resin of the base material layer) in the constitution of the invention according to claim 1 or 2. The value of the layer thickness μm) is 0.67 to 20.

With this configuration, the basis weight of the base material layer and the thickness of the PBT resin layer are in an appropriate range.

The invention according to claim 4 is a storage container group obtained by hot-press molding a state in which a plurality of sheet-shaped members are stacked, and each storage container constituting the storage container group is made of a paper material. It is composed of a base material layer and a polybutylene terephthalate (PBT) resin layer laminated on at least one of the base material layers, and the basis weight of the base material layer is 20 g / m ^{2 to} 100 g / m ² , and the PBT resin. The thickness of the layer is 5 μm to 30 μm, and the degree of crystallization of the PBT resin layer is 9.0% or more.

With this configuration, it is possible to prevent an event in which blocking occurs over the entire circumference in the circumferential direction between the stacked storage containers.

The invention according to claim 5 has a crystallinity of 11.5% or more in the PBT resin layer in the constitution of the invention according to claim 4.

With such a configuration, it is also possible to prevent blocking from occurring in a range of less than 1/4 in the circumferential direction between the stacked storage containers.

The invention according to claim 6 has no partial blocking in which blocking occurs in a range of less than 1/4 in the circumferential direction between the stacked storage containers in the configuration of the invention according to claim 5. ..

With such a configuration, it becomes easy to take out the storage container at the time of use.

The invention according to claim 7 is the ratio of the basis weight of the base material layer to the thickness of the PBT resin layer (basis weight g / m ^{2 of the base material layer) in any of the configurations of the inventions according to claims 4 to 6.} The value of ÷ PBT resin layer thickness μm) is 0.67 to 20.

With this configuration, the basis weight of the base material layer and the thickness of the PBT resin layer are in an appropriate range.

As described above, the invention according to claim 1 can prevent an event in which blocking occurs over the entire circumference in the circumferential direction between the stacked storage containers, and thus is easy to take out and use at the time of use.

In addition to the effects of the invention according to claim 1, the invention according to claim 2 can further prevent blocking from occurring in a range of less than 1/4 in the circumferential direction between the stacked storage containers. Therefore, it is easier to take out and use when using.

In the invention according to claim 3, in addition to the effects of the invention according to claim 1 or 2, the basis weight of the base material layer and the thickness of the PBT resin layer are within an appropriate range. More preferable ones are obtained.

The invention according to claim 4 is easy to take out at the time of use and easy to use because it is possible to prevent an event in which blocking occurs over the entire circumference in the circumferential direction between the stacked storage containers.

In addition to the effects of the invention according to claim 4, the invention according to claim 5 can further prevent blocking from occurring in a range of less than 1/4 in the circumferential direction between the stacked storage containers. Therefore, it is easier to take out and use when using it.

The invention according to claim 6 has the effect of the invention according to claim 5, and since it is easy to take out the storage container at the time of use, it is further easy to take out at the time of use and easy to use.

The invention according to claim 7 is manufactured and manufactured because, in addition to the effects of any of the inventions according to claims 4 to 6, the basis weight of the base material layer and the thickness of the PBT resin layer are in an appropriate range. More preferable ones can be obtained in terms of use.

It is a partial end view which shows the storage container group of 1st Embodiment of this invention. It is a figure which shows one storage container included in the storage container group shown in FIG. 1, (a) is a plan view, (b) is a side view, (c) is a sectional view of the P portion in the said (b). Shown. It is a schematic diagram which shows an example of the molding apparatus which manufactures a storage container group. It is a schematic diagram explaining the degree of blocking. It is a schematic diagram which showed the blocking of the conventional storage container group.

FIG. 1 is a partial end view showing a storage container group according to the first embodiment of the present invention, and FIG. 2 is a view showing one storage container included in the storage container group shown in FIG. 1 (a). ) Is a plan view, (b) is a side view, and (c) is a cross-sectional view of the P portion in the (b).

With reference to these figures, the storage container group 10 is configured by stacking a plurality of storage containers 11 having an opening at the upper side.

The storage container 11 has a bottom portion 12 formed in a circular shape in a plan view, and a peripheral wall portion 13 that stands up from the peripheral edge of the bottom portion 12 and has folds formed in the circumferential direction. The storage container 11 is composed of a base material layer 15 made of a paper material and a polybutylene terephthalate (PBT) resin layer 16 laminated on the base material layer 15.

The basis weight of the base layer 15 ^is a ^{20g / m 2 ~100g / m 2} , more ^preferably from ^{20g / m 2 ~80g / m 2} .

The thickness of the PBT resin layer 16 is 5 μm to 30 μm, more preferably 10 μm to 25 μm, and even more preferably 10 μm to 20 μm.

Here, the value of the ratio of the basis weight (g / m ² ) of the base material layer 15 to the thickness (μm) of the PBT resin layer 16 (basis weight g / m ^{2 of the} base material layer ÷ thickness μm of the PBT resin layer) is , 0.67 to 20, but more preferably 1 to 8. With this configuration, the basis weight of the base material layer and the thickness of the PBT resin layer are in an appropriate range, so that more preferable ones can be obtained in terms of production and use.

The above-mentioned storage container group 10 is obtained by hot press molding in a state where a plurality of sheet-shaped members are stacked. An exemplary method for hot press molding is as follows.

FIG. 3 is a schematic view showing an example of a molding apparatus for producing a storage container group.

With reference to the figure, the press molding apparatus 20 for producing the storage container group has a male mold 21, a female mold 23 corresponding to the male mold 21, and a tubular portion 25 connected to the downstream side of the female mold 23. Be prepared. Further, although not particularly shown in the figure, a moving means for bringing the male mold 21 closer to and separated from the female mold 23, a heater for heating each of the female mold 23 and the tubular portion 25, and the operation of this heater. It is provided with a control means for controlling the above.

Using such a press molding apparatus 20, the storage container is manufactured by the following steps. First, the female mold 23 and the tubular portion 25 are heated to an appropriate temperature with a heater. Next, a blank laminate as a plurality of sheet-like members is arranged between the male mold 21 and the female mold 23, and then the male mold 21 is moved in a direction approaching the female mold 23 by a moving means, and the male mold is moved. A blank laminate is sandwiched between the 21 and the female mold 23. Subsequently, with the blank laminate sandwiched between the male mold 21 and the female mold 23, the pressing portion 22 provided on the male mold 21 is moved downward to press the blank laminate toward the tubular portion 25. As a result, an intermediate molded body 40 in which the bottom portion and the peripheral wall portion are formed as a whole of the blank laminated body is obtained, and the intermediate molded body 40 advances into the tubular portion 25.

Subsequently, the male mold 21 was separated from the female mold 23, and the next blank laminate was arranged between the male mold 21 and the female mold 23 in a state where the first intermediate molded body was held in the tubular portion 25. After that, the above-mentioned steps are executed again to form the next intermediate molded body so as to be stacked on the first intermediate molded body.

By repeating the above steps several times, the previous intermediate molded body is pressed by the next intermediate molded body and moves in the tubular portion, and finally, the discharge port of the tubular portion 25. The intermediate molded body is discharged in order from. In the process of moving the tubular portion 25, the intermediate molded body is heated to stabilize its shape. In this way, the storage container group 10 is obtained, and the individual storage containers 11 can be taken out from the storage container group 10.

In the present invention, since the crystallinity of the PBT resin layer constituting the storage container is 9.0% or more, it is possible to prevent an event in which blocking occurs over the entire circumference in the circumferential direction between the stacked storage containers 11. it can. As a result, when the storage container 11 is used, each storage container 11 can be easily taken out from the storage container group 10 and is easy to use. Further, the crystallinity of the PBT resin layer is more preferably 11.5% or more. Partial blocking, in which blocking occurs in a range of less than 1/4 in the circumferential direction between the stacked storage containers, is substantially eliminated. The crystallinity of the PBT resin layer can be obtained by calculating the relative crystallinity by the transmission method using a wide-angle X-ray diffraction measuring device.

More, in the container described above, it can be said that the basis weight of the base layer, in that it is set to ^{20g / m 2 ~100g / m 2} , as the paper material is adopted relatively thin .. Therefore, since the rigidity is relatively weak, it can be said that the upper and lower storage containers are easily deformed and come into contact with each other during molding or when the tubular portion for maintaining the shape is heated, and blocking is likely to occur. On the other hand, if the basis weight of the base material layer is increased in order to obtain high rigidity, deformation of each storage container is suppressed, so that blocking may be less likely to occur, but press molding is performed with a plurality of blanks stacked. Becomes difficult.

Therefore, according to the above-mentioned storage container, it can be said that blocking can be efficiently suppressed by various settings such as crystallinity in a situation where the rigidity is relatively weak and blocking is likely to occur.

In FIG. 1, the number of stacked storage containers is specific, but the number of stacked containers is not particularly limited. Further, in the above embodiment, the storage container is formed in a specific shape in a plan view, but the storage container is not limited to this. The storage container may also be formed in an elliptical shape, a quadrangle with rounded corners, or another polygonal shape in a plan view. Furthermore, folds may not be formed on the peripheral wall portion of the storage container, or folds may be formed on a part of the circumferential direction (for example, a corner portion of a polygonal shape).

Further, in the above-described embodiment, the hot press molding method using a molding apparatus having a specific structure has been described, but the present invention is not limited to this. The method of hot press molding is not particularly limited as long as the storage container group is produced. For example, the storage container group can be produced by press molding using a conventionally known device and method.

Further, in the above-described embodiment, it has been described that the base material layer is made of a paper material, but printing ink or wax coating may be applied in addition to the above-described embodiment. That is, the sheet member used for molding the storage container group may have a configuration in which a PBT resin layer, a printing ink layer, a paper sheet layer, and a wax coat layer are laminated in this order. Further, an anchor coat layer may be interposed between the base material layer and the PBT resin layer, or the paper material constituting the base material layer may be subjected to corona treatment.

Further, the PBT resin layer may be laminated not only on one of the base materials but also on the other.

Further, although not particularly described in the above embodiment, as the paper material constituting the base material layer, pure white roll paper, kraft paper, parchment paper, ivory paper, Manila paper, card, etc., depending on the desired application. Paper, cup paper, etc. can be used.

Further, although not particularly described in the above embodiment, the method of laminating the PBT resin on the base material layer (paper material) is not particularly limited, and extrusion lamination, thermal lamination, dry lamination, wet lamination and the like can be exemplified. ..

Hereinafter, the present invention will be specifically described based on Examples. The embodiment of the present invention is not limited to the examples.

(Preparation of Examples)
The storage container group according to the example was prepared as follows.

Twelve blanks cut out from the sheet body were laminated to form a blank laminated body of one unit, which was set in the molding apparatus described in the above embodiment and molded under the following conditions.

Molding speed: 3 seconds / shot (* 1)
Retention amount of intermediate molded body in the cylinder: 6 Molding temperature: 170 degrees (* 2)
(* 1) Shot refers to forming one unit of intermediate laminate from one unit of blank laminate.

The configuration of each storage container constituting the storage container group is as follows, and the PBT resin layer is formed on the inner side (storage surface side) of the storage container, and the PBT resin layer is crystallinized. There were 9 types of degrees in the following range.

Base layer basis weight: 35 g / m ²
Thickness of PBT resin layer: 15 μm
Ratio of the basis weight of the base material layer to the thickness of the PBT resin layer (basis weight g / m ^{2 of the} base material layer ÷ thickness μm of the PBT resin layer): 35 g / m ² ÷ 15 μm = 2.33
Crystallinity: 2.3% to 20.2%
(* 2) Refers to the set temperature of the female mold and cylinder.

(Test of the degree of blocking and the number of occurrences)
Prepare the storage container group as described in the production of the above embodiment, and configure the storage container for the outermost one of the blank laminates of the storage container group discharged from the discharge port of the cylinder portion, which is in contact with the cylinder portion. The crystallinity of the PBT resin layer was evaluated as follows.

FIG. 4 is a schematic diagram illustrating the degree of blocking.

First, referring to (a), between one of the stacked storage containers and the storage container stacked directly above it, blocking does not occur over the entire circumference of the peripheral wall portion (no blocking), and then In (b), the blocking occurrence part 50 was confirmed in the range of less than 1/4 in the circumferential direction of the peripheral wall (blocking less than 1/4), and finally, referring to (c), the peripheral wall. Those in which the blocking generation part 50 was confirmed in the range of 1/4 or more (including the entire circumference) in the circumferential direction of the part (wide area blocking) were counted respectively.

A total of 12 storage containers are included in the 1-unit storage container group obtained from the 1-unit blank laminate, and the outermost 1 unit of the 1-unit storage container group in contact with the cylinder is extracted to evaluate blocking. In the same manner, evaluation for 10 units of the storage container group was performed. That is, out of a total of 12 storage containers included in one unit of storage container group, the outermost one in contact with the cylinder was collected for 10 units of the storage container group, and the total of 10 storage containers were evaluated. ..

However, the sticking phenomenon that occurs when the paper fibers are simply entangled in the blank end face portion between the storage containers is not counted as blocking.

(Test results)
Table 1 below shows nine types of storage containers for each degree of crystallinity and the corresponding test results.

表１を参照して、比較例１及び比較例２では、広域ブロッキングが確認された。実施例１及び実施例２では、１／４未満ブロッキングが発生したものの件数的にはわずかであり、又、広域ブロッキングは発生しなかった。

With reference to Table 1, wide area blocking was confirmed in Comparative Example 1 and Comparative Example 2. In Examples 1 and 2, although less than 1/4 blocking occurred, the number of cases was small, and wide area blocking did not occur.

Therefore, in this example, the effectiveness of blocking inhibition was confirmed at a crystallinity of 9.6% or more. It is considered that a sufficient blocking suppressing effect can be obtained if the crystallinity is at least 10.0% or more.

Further, in Examples 3 to 7, not only wide area blocking but also less than 1/4 blocking did not occur. Therefore, in this example, it is considered that blocking does not basically occur when the crystallinity is 11.7% or more. Preferably, if the crystallinity is 12.0% or more, it is considered that such a further blocking suppressing effect can be obtained.

10 ... Storage container group 11 ... Storage container 12 ... Bottom 13 ... Peripheral wall 15 ... Base material layer 16 ... PBT resin layer The same reference numerals in each figure indicate the same or corresponding parts.

Claims (7)

A storage container taken out from a storage container group obtained by hot-press molding a state in which a plurality of sheet-like members are stacked, and the storage container is a base material layer made of a paper material and the base material. Consists of a polybutylene terephthalate (PBT) resin layer laminated on at least one of the layers.
The basis weight of the base layer ^is a ^{20g / m 2 ~100g / m 2} ,
The thickness of the PBT resin layer is 5 μm to 30 μm.
A storage container in which the crystallinity of the PBT resin layer is 9.0% or more. The storage container according to claim 1, wherein the crystallinity of the PBT resin layer is 11.5% or more. The value of the ratio of the basis weight of the base material layer to the thickness of the PBT resin layer (basis weight g / m ^{2 of the} base material layer ÷ thickness μm of the PBT resin layer) is 0.67 to 20, claim 1. Or the storage container according to claim 2. A storage container group obtained by hot-press molding a state in which a plurality of sheet-like members are stacked, and a base material layer in which each storage container constituting the storage container group is made of a paper material and the base. It is composed of a polybutylene terephthalate (PBT) resin layer laminated on at least one of the material layers.
The basis weight of the base layer ^is a ^{20g / m 2 ~100g / m 2} ,
The thickness of the PBT resin layer is 5 μm to 30 μm.
A group of storage containers in which the crystallinity of the PBT resin layer is 9.0% or more. The storage container group according to claim 4, wherein the crystallinity of the PBT resin layer is 11.5% or more. The storage container group according to claim 5, wherein partial blocking occurs in a range of less than 1/4 in the circumferential direction between the stacked storage containers. The value of the ratio of the basis weight of the base material layer to the thickness of the PBT resin layer (basis weight g / m ^{2 of the} base material layer ÷ thickness μm of the PBT resin layer) is 0.67 to 20, claim 4. The storage container group according to any one of claims 6.

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