JP2838486B2 - Easy open container - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for storing foods having a high moisture content such as tofu and anmitsu in a main body, sealing the foods with a lid, and holding the lid by hand when eating the food. The present invention relates to an easy-open container that can be easily opened by using an easy-open container.

[0002]

2. Description of the Related Art Watery foods such as tough and foodstuffs containing a large amount of water do not leak out when they are stored in a container body and sealed with a lid, for example, at the time of sale or display or transportation. In this manner, the lid is completely sealed to the main body by means such as heat sealing. The heat-sealed lid is pulled away from the main body by hand when eating food or the like. A packaging container capable of performing such operations is called an easy-open container.

[0003] The following points are demanded for such an easy-open container. Of course, the seal between the body and the lid must be perfect. However, the lid must be sealed to the main body with an adhesive force that can be separated by hand. In other words, the adhesive strength between the two must be sufficient at the time of transportation and handling, but for easy opening, it must be of such a size that it can be easily separated by hand. The main body and the lid are provided at a low cost and are formed of a hygienic synthetic resin sheet or the like, but must not be deteriorated during the molding. When molding a synthetic resin sheet or the like, it is generally difficult to make the thickness uniform in all parts, and this and the above must be solved simultaneously.

[0004] Some of the above demands have been solved to some extent in, for example, "thermoforming materials and thermoformed articles" proposed in JP-A-4-293920. That is, in the above-mentioned publication, "a material having an expanded condition width to obtain a transparent thermoformed product as compared with conventionally used polyethylene terephthalate" and a transparent portion of the sealed portion when the end portion of the thermoformed product is heat-sealed. For the purpose of providing a thermoformed product having good properties, `` mainly composed of an ethylene glycol component and a dicarboxylic acid component, the dicarboxylic acid component is based on the total amount of the dicarboxylic acid component, and the terephthalic acid component is 98 to 98%. A thermoforming material comprising a polyester in which 50% by mole and 2 to 50% by mole of an isophthalic acid component have been copolymerized or / and mixed, and a thermoformed product obtained from the material have been proposed.
Although "transparency" is ensured to some extent, the above-mentioned and in particular have not been specifically solved.

Japanese Patent Application Laid-Open No. 5-212840 proposes a "heat-sealable polyester sheet having a two-layer structure of a polyester layer and an amorphous polyester layer". And can be processed into blister packages for various packaging, food trays, and containers by utilizing this feature. " However, the heat-sealable polyester sheet disclosed in Japanese Patent Application Laid-Open No. 5-212840 has not been able to completely solve the problems particularly in an easy-open container.

[0006] Further, Japanese Patent Application Laid-Open No. 4-300924 discloses "a method for bonding a polyethylene terephthalate resin film or sheet firmly with an adhesive," A polyethylene terephthalate resin film or sheet having a layer of a polymerized polyester resin is bonded using an adhesive obtained by dissolving a thickening resin in one or more organic solvents that dissolve or swell the copolymerized polyester resin. "A method of bonding a polyester film or sheet" has been proposed.

However, the method for bonding a polyester film or sheet is described in paragraphs 15 to
As described in No. 17, "polyethylene terephthalate resin (a) and a dicarboxylic acid component comprising 50% of terephthalic acid, a diol component comprising 25 mol% of ethylene glycol and 25 mol% of 1,4-cyclohexanedimethanol. A polymerized polyester resin (b) was prepared, and the resin (a) and the resin (b) were melt-extruded and formed into a three-layer sheet form from a flat die of a three-layer co-extrusion apparatus, and a copolymerized polyester resin was formed on both surfaces. A film of a polyethylene terephthalate resin (a) having a layer (b) was prepared having a thickness of 140 μm.
The thickness of each of (b) was 30 μm. Further, the above-mentioned copolymerized polyester resin (b) was added to tetrahydrofuran (solubility parameter:
9.317) to prepare an adhesive. Using this adhesive, the two films in accordance with JIS grayed Labia print 6854 is strongly adhered, the film was broken without peeling from the film surface. If this is applied to an easy-open container, not only can the lid not be separated from the main body, but if it is forcibly separated, the lid and the main body will break, and eventually the above Cannot be achieved.

The inventor of the present invention has conducted intensive studies on how to simultaneously solve all of the above-mentioned demands in this kind of easy-open container, and as a result, completed the present invention. is there.

[0009]

SUMMARY OF THE INVENTION The present invention has been made on the basis of the above circumstances, and the problem to be solved is to provide an easy-open container of this kind in which all of the above-mentioned problems have been solved. It is.

That is, the object of the present invention is to
An object of the present invention is to provide an easy-open container that does not become clouded (crystallized) during molding and heat sealing, and that can maintain the adhesive strength between a main body and a lid within an appropriate range.

[0011]

In order to solve the above problems, the means adopted by the present invention will be described with reference to the reference numerals used in the embodiment shown in the drawings.
A portion of a main body 11 molded as a first sealing surface 13 ring-shaped having a concave-convex, first in order to integrate the main body 11 1
A lid 14 formed as having an annular second sealing surface 16 facing the sealing surface 13, and a lid 14 formed on the first or second sealing surfaces 13, 16 for the main body 11.
An easy-open container 10 having an adhesive layer 18 for heat-sealing, wherein the main body 11 is made of (a) isophthalic acid as a dicarboxylic acid component or 1,4-cyclohexanedimethanol as (b) a diol component. Or 10 to 40 mol% of neopentyl glycol
Molded from an amorphous copolyester containing
The were thus molded into polyester Le, and the adhesive layer 18
With a polyester-based adhesive for gravure printing of 1 μm to 6 μm.
An easy-open container 10 "characterized by being formed by gravure printing with a thickness of μm.

That is, in the easy-open container 10 of the present invention, the main body 11 is connected to at least the first sealing surface 1.
3, (a) isophthalic acid in the dicarboxylic acid component or, (ii) a diol component of 1,4 - needs to be shaped by cyclohexanedimethanol or neopentyl Nchirugu recall 10 to 40 mole% containing amorphous copolyester . The reason for this is that the easy-open container 10 is heated not only at the time of molding the main body 11 but also at the time of performing heat sealing to the main body 11 with the adhesive layer 18 described later. In addition, it is necessary to prevent the material of the main body 11 from crystallizing and becoming cloudy.

Further, the main body 11 has a flange 12 on the upper outer periphery thereof, and it is necessary that the annular first sealing surface 13 is positively formed on the flange 12. The reason for this is that when positioning the lid 14 described later on the main body 11, it is necessary to facilitate the operation mechanically.
This is because it is necessary to ensure that the heat sealing with the adhesive layer 18 described later can be performed with a small area by forming the.

As the dicarboxylic acid component, for example, 2,6
-Naphthalenedicarboxylic acid, 2,7 -naphthalenedicarboxylic acid, phthalic acid, diphenyldicarboxylic acid, diphenyletherdicarboxylic acid, diphenoxyethanedicarboxylic acid, diphenylmethanedicarboxylic acid, diphenylketonedicarboxylic acid, diphenylsulfidedicarboxylic acid, diphenylsulfonedicarboxylic acid, aliphatic Dicarboxylic acids (eg, succinic acid, adibic acid, sebacic acid, etc.) and alicyclic dicarboxylic acids (eg, cyclohexanedicarboxylic acid,
Tetralin dicarboxylic acid, decalin dicarboxylic acid, etc.).

Further, as the lid 14, it is necessary is obtained by <br/> Thus formed polyester Le, because,
In the body 11 formed by the above material, because those having a concave convex first sealing surface 13 is formed on the flange 12 is not become a uniform thickness, the lid on the irregularities 14 This is for completely aligning the second sealing surface 16 on the side during heat sealing.

In particular, the lid 14 also has a flange 15 on the periphery thereof, and the flange 15 has an annular second surface facing the first sealing surface 13 having the above-mentioned irregularities on the main body 11 side . It is necessary to form the sealing surface 16 positively. The reason is that this second sealing surface 16
The adhesive layer 18 described later is formed by gravure printing. The range and position of the adhesive layer 18 are clarified to facilitate heat sealing by a machine ,
This is because it is necessary to absorb as much as possible the irregularities of the first seal surface 13. In addition, the second sealing surface 1
6 is heated together with the first sealing surface 13 on the main body 11 side at the time of heat sealing, but is intended to improve workability by limiting a portion to which heat is applied by the second sealing surface 16. is there.

The adhesive layer 18 must be formed by gravure printing a polyester adhesive for gravure printing with a thickness of 1 μm to 6 μm. The reason for this is that in the easy-open container 10 in which the main body 11 containing the contents is covered by the lid 14, the adhesive layer 18 integrates the main body 11 with the lid 14 during transportation and handling. It must be complete, and when removing the contents from the body 11, the lid 1
This is because it is necessary to make it easy for humans to separate 4 from each other. In particular, when the lid 14 heat-sealed with respect to the main body 11 is separated by hand, the separation must be sufficiently easily performed by the force of a human hand, and the main body 11 and the lid 14 must not be broken. Therefore, the thickness of the adhesive layer 18 is 1 to 6 μm
It needs to be of a degree.

[0018]

The operation of the easy-open container according to the present invention configured as described above will be described with reference to the easy-open container 10 of the embodiment.
As shown in FIG. 1, a flange 12 is formed on the outer periphery of the upper part, and the flange 12 is molded as having an annular first sealing surface 13. This molding is performed by using the material described above. This is performed using a sheet made of
When the main body 11 is molded, heat is applied to the sheet material by a molding machine.
It is assumed that No. 1 has no clouded portion. Because,
This is because the material of the main body 11 is as described above, and becomes cloudy, that is, does not crystallize due to heat during molding.

The lid 14 having the second sealing surface 16 on the flange 15 is molded from a sheet made of polyester . This molding is carried out by a general means, and is opaque. It does not form a part that has been removed. In the lid 14 of the embodiment described below,
Adhesive for gravure printing is provided at a predetermined position on the material sheet.
And the adhesive layer 18 in advance printed and then, in which the portion of the adhesive layer 18 is shaped such that the second sealing surface 16.

The main body 11 molded as described above is filled with foods and the like, and then the lid 14 is heat-sealed. For this purpose, the main body 11 must be set in a heat-sealing machine. . This set work is performed on the main body 1
1 and lid 14 are flanges 12 and 15, respectively;
Since the first and second seal surfaces 13 and 16 are formed on the flanges 12 and 15, the operation is automatically performed by using these. The adhesive layer 18 formed on the second seal surface 16 of the lid 14 automatically faces the first seal surface 13 on the main body 11 side. The heat sealing with 14 is reliably performed as follows.

That is, since the lid 14 is formed of a thermoplastic resin, the lid 14 is provided with a heater (in the embodiment, FIG. 2).
And the second sealing surface 16 of the cover 14 is softened when heat is applied thereto. Then, the first sealing surface 1 on the main body 11 side
In FIG. 3, the unevenness is present as shown in FIG. 3, but if the softened second sealing surface 16 is pressed toward it, the second sealing surface 16 becomes the first sealing surface 1.
It follows the irregularities on the three sides. This allows
The adhesive layer 18 formed on the first seal surface 13 is completely along the first seal surface 13 on the main body 11 side, and the adhesion is performed by the first seal surface 13 and the second seal surface 1.
6 without any gaps.

At the time of this heat sealing, the main body 11 and the lid 14 are heated by a heater, and the first sealing face 13 and the second sealing face 16 are respectively heated.
Is limited, the heating portion is very limited. Therefore, the amount of heat applied to the main body 11 and the lid 14 during the heat sealing is relatively small, and there is not enough to crystallize the main body 11 and the lid 14 to form a cloudy portion. In particular, the main body 11
Is formed of the above-mentioned material and is hardly crystallized, so that cloudiness does not occur during this heat sealing.

At the time of the heat sealing, the polyester adhesive for gravure printing is solidified by the applied heat, whereby the first sealing surface 13 and the second sealing surface 16 are integrated. ,as a result,
The main body 11 is completely sealed by the lid 14.
The integration by the adhesive layer 18 depends on the degree of force applied during transportation and handling of the easy-open container 10 containing the contents, as shown in the examples described later.
1 does not cause peeling of the cover body 14 facing the cover 1. On the other hand, when the lid 14 is pulled away from the main body 11 by hand using the knob 17 integrally formed with the lid, the polyester-based adhesive forming the adhesive layer 18 is removed from the first sealing surface 13 by a solvent. Also, since it does not swell the second sealing surface 16, the adhesive layer 18 itself is not broken and the main body 11 or the lid 14 is not broken, and the lid 14 of the easy-open container is not damaged.
Is easily detachable.

That is, the first sealing surface 13 and the second sealing surface 16 are within a limited range, and
The adhesive layer 18 formed on the sealing surface 16 has a thickness of 1 to 6 μm.
Since the thickness is about m, the destruction of the adhesive layer 18 itself can be easily performed by the force of the detachment of the lid 14 by hand using the knob 17. Therefore, in the easy-open container 10, the easy-open as the name implies. Since the main body 11 and the lid 14 are opaque even after being heated twice, that is, they do not crystallize, the main body 11 and the lid 14 may be broken by a force of a degree that the lid 14 is separated by hand using the knob 17. There is no "fragility".

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to an easy-open container 10 which is an embodiment shown in the drawings. As shown in FIG. And a lid 14 for covering and sealing the opening of the main body 11.

The body 11 includes at least a first sealing surface 13, (a) isophthalic acid in the dicarboxylic acid component, or, (ii) a diol component 1,4 - cyclohexanedimethanol or neopentyl Nchirugu recall 10 to 40 mol %, And has an annular flange 12 integrally formed on the periphery of the upper opening thereof, as shown in FIG. In addition, the first sealing surface 13 which is annular and forms the upper end surface of the main body 11 has a predetermined width (in the embodiment, the width is about 5 mm when the main body 11 is a square having one side of about 125 mm). ).

The lid 14, which has formed by molding a polyester Cie over preparative, as shown in FIGS. 1 and 2, have an annular flange 15 on its periphery, this flange 15 An annular second seal surface 16 facing the first seal surface 13 on the main body 11 side is formed at substantially the center of the main body 11. Of course, since the lid 14 is integrated (heat-sealed) with the main body 11 and then separated by a human hand, in order to facilitate the operation, the flange 15 of the lid 14 is Knob 1 with part protruding
7, Ru der which is formed as shown in FIG.

As shown in FIG. 2 or FIG. 3, an adhesive layer 18 is formed on the inner surface of the second sealing surface 16 (the surface on the side in contact with the main body 11). The adhesive layer 18 is a prepreg formed by gravure printing a polyester-based adhesive for gravure printing on a thermoplastic resin sheet before being molded as the lid 14.
When it is molded as, it is located on the entire inner surface of the second sealing surface 16. This adhesive layer 1
The polyester-based adhesive for No. 8 is, specifically, EP209 (trade name, manufactured by Mitsubishi Yuka Co., Ltd.), and the thickness formed by gravure printing is very thin, about 1 to 6 μm.

The easy-open container 10 as described above
Is, specifically, manufactured by a material as in each of the following examples.
It is as follows.

(Example 1) Material of main body 11; trade name, manufactured by Eastman Chemical Company
PETG6763 ( 1,4 -cyclohexanedimethanol; 31
Mol%) of 0.4m thick
m was prepared, and this sheet was used as a material for thermoforming as the main body 11.

Material of lid 14; polyester adhesive for forming adhesive layer 18 of polyester sheet having a thickness of 0.23 mm; EP209 (trade name, manufactured by Mitsubishi Yuka Co., Ltd.)

As described above, the above polyester-based adhesive is gravure-printed on the material of the lid 14 with a gravure roll having a plate depth of 100 μm, and the material of the lid 14 is covered with a hot plate molding machine capable of stereotactic molding. A body 14 was formed. The main body 11 was also formed by thermoforming the above material.

[0033] (Example 2) the material of the body 11; on the homo-polyester resin sheet is a trade name RE530 manufactured by Toyo Spinning Co., Ltd., Toyo spinning stock
Product Name SI173 is made of company (neopentyl Nchirugu recall;
30 mol%) of a 20 μm thick copolyester resin.
m to form a multilayer sheet having a total thickness of 0.4 mm. Materials for lid 14 and polyester adhesive; same as in Example 1

Is a trade name RE530 manufactured by Toyo Spinning Co., thickness 0.4mm homopolyester resin sheet lid 14 and the polyester adhesive material; [0034] (Comparative Example 1) material of the body 11 in Example 1 the same as

(Comparative Example 2) Material of main body 11; trade name, manufactured by Eastman Chemical Company
9921 ( 1,4 -cyclohexanedimethanol; 3.3 mol%), a 0.4 mm thick copolyester resin sheet lid 14 and a material for a polyester-based adhesive; the same as in Example 1.

In each of the above Examples and Comparative Examples, the main body 11 and the lid 14 were formed from the materials shown above, and this was heat-sealed through the polyester-based adhesive.
Table 1 shows the results of measuring the seal strength. In this case, the sealing conditions and the sealing strength measurement conditions are as follows.

(Seal conditions) Sealing machine: SE Semi-auto type sealing machine manufactured by Universal Corporation ・ Seal pressure: 5 kg / cm ²・ Seal time: 2.0 seconds ・ Heater temperature: 160 to 220 degrees

(Measurement Conditions for Seal Strength) The sealed portion was cut into a width of 15 mm, and this was measured with a tensile tester manufactured by Toyo Seiki Co., Ltd. at a tensile strength of 300 mm / min.

Further, depending on the sheet material in each row, the main body has a plane shape of 125 mm × 125 mm,
Ten pieces each having a depth of 30 mm were formed, and 230 g of water was put therein and heat-sealed with a lid. Then, each was dropped from a height of 1 m under the condition of a room temperature of 5 ° C., and the number of pieces having a broken seal portion was examined.

The above results are shown in Table 1. In particular, the results of the seal strength test are shown as a graph in FIG.

[0041]

[Table 1]

According to this table and the graph of FIG. 4, in the easy-open container 10 according to the present invention, it is ensured that the lid 14 is integrated with the main body 11 at the time of transportation and handling. It can be understood that they can be separated sufficiently by hand.

[0043]

Effect of the Invention] above, as detailed in the present invention, as illustrated in the above embodiment, a part of the "flange 12 was formed as a first sealing surface 13 ring-shaped having an uneven body 11, a lid 14 molded to have an annular second sealing surface 16 facing the first sealing surface 13 so as to be integrated with the main body 11, and a first or second sealing surface 13. An easy-open container 10 having an adhesive layer 18 for heat-sealing the lid 14 with respect to the main body 11, wherein the main body 11 is made of (a) isophthalic acid as a dicarboxylic acid component or (b) a diol component. 10 to 40 mol% of 1,4-cyclohexanedimethanol or neopentyl glycol
Molded from an amorphous copolyester containing
The were thus molded into polyester Le, and the adhesive layer 18
With a polyester-based adhesive for gravure printing of 1 μm to 6 μm.
It was constructed as a gravure-printed one with a thickness of μm ", which has the characteristic feature of the structure. This eliminates turbidity (crystallization) during molding and heat sealing, and the adhesive strength between the main body and the lid. Can be provided in an appropriate range.

[Brief description of the drawings]

FIG. 1 is an easy-open container according to the present invention,
It is a perspective view showing the state where a part of the lid was separated.

FIG. 2 is a partially enlarged cross-sectional view showing a state of the easy-open container at the time of heat sealing and cut along a direction orthogonal to each flange.

FIG. 3 is a partially enlarged cross-sectional view of the easy-open container cut in a direction parallel to each flange.

FIG. 4 is a graph showing the results of a seal strength test of the easy-open container together with those of a comparative example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Easy open container 11 Main body 12 Flange 13 1st sealing surface 14 Lid 15 Flange 16 2nd sealing surface 17 Knob part 18 Adhesive layer

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B65D 1/00-1/48 B65D 35/44-35/54 B65D 39/00-55/16 B65D 65/00-65 / 46 B65D 67/00-79/02 B65D 81/18-81/30 B65D 81/38 B65D 81/32-81/36 B65D 6/00-13/02 B32B 1/00-35/00 C09J 1/00 -1/02 C09J 4/00-5/10 C09J 9/00-201/10 C08G 18/00-18/87 C08G 71/00-71/04 C08K 3/00-13/00 C08L 1/00-101 / 00 C09J 1/00-1/02 C09J 4/00-5/10 C09J 9/00-201/10 C08J 7/04-7/06 B29C 67/00-73/34 B29D 1/00-31/02

Claims (1)

(57) [Claims] The method according to claim 1 Some of the flange, a body molded as a first sealing surface ring-shaped having a concave-convex, the second sealing surface of the annular facing the first sealing surface so as to integrate into the body Yes The first or second cover,
An easy-open container having an adhesive layer formed on a sealing surface for heat-sealing the lid with respect to the main body, wherein the main body comprises : (a) isophthalic acid of a dicarboxylic acid component or (ii) a diol Component 1,4-cyclohexanedimethanol or neopentyl glycol is 10 to 40 mol%
Molded by amorphous copolyesters containing, constituting the lid, and thus molded into a polyester Le, and the adhesive layer, a gravure printing polyester adhesive as those gravure printing to a thickness of 1μm~6μm Easy open container characterized by doing.