JP2001354226A - Heat insulation paper-made container and method for manufacturing it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an innovative heat insulation paper-made container that holds noodle in the middle portion of the heat-insulation paper-made container when hot water is poured in the container and, at the same time, prevents the noodle from floating, thus enabling the boodles to be loosened sufficiently. SOLUTION: A container body member 1 is made of a base material in which a thermoplastic resin layer 10 having a high melting point is interposed between two base sheets 11 and 12 and the surface of the base sheets 11 and 12 are respectively laminated with thermoplastic synthetic resin layers 13 and 14 having a low melting point. An upper flange 16 is formed on the upper edge of the opening of the container main body member 1. A bottom is fitted in the body member 1 to be integrated with it, thereby obtaining a container including the thermoplastic synthetic resin layers 13 and 14 having the low melting point arranged respectively on the inner surface and outer surface of the container body member 1. The thermoplastic synthetic resin layers 13 and 14 are heat-foamed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to stacking a low-melting-point thermoplastic synthetic resin layer on a base paper constituting a container body member, and heating and foaming the low-melting-point thermoplastic synthetic resin layer to obtain heat insulation. The present invention relates to a heat insulating paper container and a method for manufacturing the same.

[0002]

2. Description of the Related Art A paper container formed by stacking a low-melting thermoplastic synthetic resin layer foaming by heat treatment on the outer wall surface of the base paper of the body material of the cup-shaped paper container is heated. A foamed heat insulating paper container in which the thermoplastic synthetic resin layer is foamed is known, for example, from JP-A-11-189279. On the other hand, when filling noodles into a container for instant noodles conventionally,
The noodles are floated and filled so that the noodles do not stick to the bottom of the container. This is because when hot water is added, hot water is also put under the noodles, and the noodles are loosened from the top and bottom of the noodles, soups, ingredients, etc. are mixed well, and the noodles are evenly loosened and put in a good condition It is. In addition, soups, ingredients, etc. are placed on the noodles, so that it is clear that the soups, ingredients, etc. are contained when pouring hot water, but the noodles have rattling on the bottom of the container In addition, there is a possibility that soups, ingredients and the like may get under the noodles during transportation, and in order to prevent this, the noodles are filled without being attached to the bottom of the container.

[0003]

As described above, in the case of instant noodles, the noodles are filled while floating in the middle of the container. However, in a known paper container, a thermoplastic synthetic resin layer is formed on the inner surface of the container body member. Are stacked and the surface is smooth, so that when filled with hot water, the noodles may float on the hot water, and there is a problem that the noodles cannot be sufficiently loosened. Therefore, in the present invention, a new heat insulating property that enables the noodles to be sufficiently loosened even if the noodles are held in the middle of the container so that the noodles do not come out even if hot water is put in the container. It is an object to provide a paper container.

In the present invention, the low-melting point thermoplastic synthetic resin layer stacked on the base paper is foamed in order to obtain heat insulation. However, foaming up to the upper flange at the opening edge of the container deteriorates the mouthfeel. A new heat insulating paper container that prevents this problem is also provided. Further, the present invention also provides a novel method for producing a heat-insulating paper container which does not foam up to the upper flange portion of the container opening edge when the container is heated and foamed.

[0005]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a high-melting thermoplastic synthetic resin layer interposed between two base papers, and a low-melting thermoplastic synthetic resin layer on the surface of each base paper. The container body member is composed of the weighed raw materials, has an upper flange portion at an upper edge of an opening of the container body member, incorporates a bottom, and is integrated, and has a low melting point thermoplastic synthetic resin on each of the inner and outer surfaces of the container body member. The container is provided with a layer, and is heated to foam the low-melting-point thermoplastic synthetic resin layer on the inner and outer surfaces. As a result, the inner surface of the container body member was foamed, and the surface was roughened, so that the noodles were held well.

In the present invention, the upper flange portion of the upper edge of the opening of the container body member is forcibly machined into a square cross section. As a result, it was possible to obtain a palatable heat-insulating paper container without foaming the upper flange portion of the opening edge of the container body member.

Further, according to the present invention, the inner winding end of the upper flange portion forcibly machined into a square cross section is overlapped with the upper portion of the flange portion to form a double structure at the upper portion of the flange portion. Thereby, the strength of the upper flange portion can be increased, and the strength of the entire container can also be increased.

Further, according to the present invention, since the low-melting point thermoplastic synthetic resin layer is a low-density polyethylene film, it can be easily formed into a container and can be adapted to a food container. Since the high-melting-point thermoplastic synthetic resin layer is a polypropylene resin layer, the lamination with the base paper can be easily extruded without an adhesive.

Since the high-melting point thermoplastic synthetic resin layer has a water vapor permeability of 20 g / m ² · 24 hr or less under the measurement conditions of a temperature of 40 ° C. and a humidity of 90%, a container having excellent water vapor barrier properties can be obtained. Got none. Similarly, the oxygen permeability of the high melting point thermoplastic synthetic resin layer, the temperature 20 ℃,
In 90% humidity measurement conditions, 120cc / m ² · ²
Since it was 4 hours or less, a container having excellent oxygen barrier properties could be obtained.

The total weight of the two base papers is compared with the total weight of the high-melting thermoplastic synthetic resin layer and the inner and lower low-melting thermoplastic synthetic resin layers. Since the weight of the paper is larger than the total weight of the paper, the paper container according to the Recycling Law can be made to be a container excellent in recycling economy.

Further, the method according to the present invention is characterized in that the paper container is heated while being transferred on a traveling belt with its upper flange portion down, and transferred while cooling the upper flange portion. As a result, good foaming of the low melting point thermoplastic synthetic resin layer of the container body member is obtained, foaming of the upper flange portion is prevented, and sealing of the lid material is facilitated without hindering sealing with the lid material. Thus, a heat-insulating paper container suitable for a food container is obtained.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a half sectional front view showing an embodiment of the heat insulating paper container according to the present invention, and FIG. 2 is an enlarged sectional view showing details of an upper flange portion and a subsequent upper portion of the container body member. . The heat-insulating paper container according to the present invention includes a container body member 1 and a bottom plate member 2. First, the container body member 1 will be described. The container body member 1 has a high melting point thermoplastic synthetic resin layer 10 having excellent barrier properties against oxygen and water vapor at the center. The two base papers 11 and 12 are stacked and interposed. In the embodiment shown, the base paper 11 is positioned outside the container and the base paper 12 is positioned inside.
On the surfaces of the base papers 11 and 12, thermoplastic synthetic resin layers 13 and 14 having a low melting point are stacked.
Further, a printing layer 15 is provided on the surface of the thermoplastic synthetic resin layer 13 outside the container body member 1.

[0013] The thermoplastic synthetic resin layer having a high melting point, which is the center, is made of a polypropylene resin having excellent steam barrier properties and a polybutylene terephthalate resin or polyethylene terephthalate resin having excellent oxygen barrier properties, which can be extruded and laminated, and a base paper. It is preferable in that it can be processed without an adhesive, and may be a resin layer of ethylene-vinyl alcohol copolymer, PVC, PVDC, acrylonitrile, polycarbonate, nylon or the like, or a moisture-proof cellophane layer. In the illustrated embodiment, the thickness is between 15 and
A polypropylene resin layer having a thickness of 25 μm and a melting point of 160 to 165 ° C. is used. And this high melting point thermoplastic synthetic resin layer has a water vapor permeability of 40 ° C.
Under measurement conditions of 90% humidity, 0.3 to 20 g / m ²
・ 24 hours. Similarly, this high melting point thermoplastic synthetic resin layer has an oxygen permeability of 20 ° C. and 90% humidity.
In the measurement conditions, 0.3~120cc / m ² · 24
hr.

The base paper 11 stacked on the outer surface of the high melting point thermoplastic synthetic resin layer 10 has a basis weight of 160 to 250 g / m ^2.
And having a water content of 7 to 8.5%. Similarly, the base paper 12 stacked on the inside of the high melting point thermoplastic synthetic resin layer 10 has a basis weight of 150 to 200 g / m ² and a water content of 6.5 to 8.5%.

The outer low-melting-point thermoplastic synthetic resin layer may have an MFR (melt flow rate) of 8 to 1
5 g / 10 min, melting point 105-110 ° C, thickness 50-70
A low-density polyethylene film of μm is used, and an MFR (melt flow rate) of 4 to 15 g / 10 minutes and a melting point of 105 to
A low-density polyethylene film having a temperature of 110 ° C. and a thickness of 20 to 40 μm is used. The outer printing layer 15 is coated with a tuning ink which is synchronized with the heating and foaming of the low-melting thermoplastic synthetic resin layer. As the tuning ink, as a resin composition containing an organic or inorganic pigment, a urethane-based resin and a vinyl chloride-vinyl acetate copolymer resin (vinyl acetate resin), a ketone-based, an ethyl acetate-based, an alcohol-based, and a toluene-based resin are used. Using a solvent and a polyethylene wax as an auxiliary, an ink with a small amount of residual solvent, which is appropriately adjusted in viscosity, does not hinder the foaming of the polyethylene film as the thermoplastic synthetic resin film 13 to be foamed, and the thermoplastic resin after foaming. As a result, a smooth printed surface that does not give a feeling of unevenness to the surface of the resin can be obtained.

An upper flange portion 16 is provided at an upper opening edge of the container body member 1, and the upper flange portion 16 is forcibly machined into a rectangular cross section as shown in FIGS. The inner winding end 18 is overlapped on the upper portion of the upper flange portion 16, and the upper portion of the upper flange portion 16 has a double structure. On the other hand, the bottom plate member 2 is formed by stacking a high melting point thermoplastic synthetic resin layer on the inside of a conventionally known base paper, and stacking a low melting point thermoplastic synthetic resin layer on the outer surface,
This low melting point thermoplastic synthetic resin layer may be foamed.

Further, in the heat-insulating paper container of the present invention, the weight of the paper obtained by combining the two base papers 11 and 12 stacked inside and outside the high-melting thermoplastic synthetic resin layer 10 serving as the center, Thermoplastic synthetic resin layer 10 and low melting point thermoplastic synthetic resin layers 13 and 14 stacked on the surface of each of the base papers.
By comparing the weight of the synthetic resin with the weight of the synthetic resin, the weight of the paper is made larger than the weight of the synthetic resin. For example, as described above, the central high melting point thermoplastic synthetic resin layer 10 is a polypropylene resin layer having a thickness of 15 to 25 μm, and the outer base paper 11 has a basis weight of 160 to 250 g / m ² , and the outer The low melting point thermoplastic synthetic resin layer 13 having a thickness of 5
A low-density polyethylene film having a thickness of 0 to 70 μm, an inner base paper 12 having a basis weight of 150 to 200 g / m ^2, and a low-melting thermoplastic synthetic resin layer 14 having a thickness of 20
A low-density polyethylene film having a diameter of 96 mm, a total height of 107 mm, and a body inclination angle of 6 ° 3
When a cup-shaped container is set as 0 ', the total weight of the central polypropylene resin layer and the inner and outer low-density polyethylene films is 2.4 to 4 g, and the total weight of the two base papers is 10.4 to 14 g. 0.6 g. By making the total weight of the base paper larger than the total weight of the synthetic resin as described above, the present invention is applied to a paper container according to the Recycling Law, and the cost of recycling can be made lower than that of the plastic container.

Next, a method for manufacturing the heat insulating paper container of the present invention will be described with reference to FIGS. That is,
Low melting point thermoplastic synthetic resin layer 1 on inner and outer surfaces of container body member 1
This is a method of heating 3 and 14 to foam them. In the present invention, the paper container is conveyed while being placed on the running belt 3 with its upper flange 16 down, and heated using an infrared heater having a wavelength of 0.4 μm to 1 mm. There are three running belts near the entrance, near the middle, and near the exit.
Heat to 0-130 ° C, and transfer time near this entrance,
0.75 to 1.5 minutes. Similarly, near the middle, temperature 1
To 115 ° C., and the transfer time around this middle is
0.75 to 1.5 minutes. In addition, the temperature near the exit is 10
Heat to 5 to 115 ° C. and set the transfer time near the outlet to 0.7
5 to 1.5 minutes.

Further, in the embodiment shown in FIGS. 3 and 4,
Belt guide members 4 and 5 are provided on both sides of the traveling belt 3 in parallel, and one belt guide member 4 is provided with a stepped portion 6. A part of the upper flange 16 of the container is placed on this stepped portion 6, The paper container is transported while rotating the paper container on the traveling belt, with the flange 16 placed on the traveling belt and transported. As a result, the entire container could be heated evenly, and the finish could be further improved. Further, a cooling water passage 7 is provided in the belt guide member 4 to cool the upper flange portion 16 of the container body member 1 through the cooling water, thereby preventing the upper flange portion 16 from being heated and foamed.

[0020]

As described above, in the heat insulating paper container of the present invention,
Since the low melting point thermoplastic synthetic resin layer is also stacked and foamed on the inner surface of the container body member, the surface is rough and the instant noodle to be filled can be reliably held in the middle of the container. Since a high-melting-point thermoplastic synthetic resin layer was interposed between the two base papers, a highly heat-insulating paper container was obtained. In addition, since the upper flange portion was forcibly processed to have a square cross section, it was possible to obtain a heat-insulating paper container having a good mouth feel without foaming the upper flange portion, and to easily seal the lid material.

Further, in the heat-insulating paper container of the present invention, since the inner wrapping end of the upper flange portion is overlapped with the upper portion of the flange portion, the strength of the upper flange portion can be increased, and the strength of the entire container can be improved. Can be enhanced. Further, since the low-melting-point thermoplastic synthetic resin layer is made of a low-density polyethylene film, it is easy to mold the container and can be adapted to a food container. Since the high-melting thermoplastic synthetic resin layer is a polypropylene resin layer, the lamination with the base paper can be easily extruded without an adhesive, and the lamination can be easily performed. is there.

Further, since the high-melting point thermoplastic synthetic resin layer has a water vapor permeability of 20 g / m ² · 24 hr or less under the measurement conditions of a temperature of 40 ° C. and a humidity of 90%, it has an excellent water vapor barrier property. It is a heat insulating paper container. Further, since the oxygen permeability of the high melting point thermoplastic synthetic resin layer is 120 cc / m ² · 24 hr or less under the measurement conditions of a temperature of 20 ° C. and a humidity of 90%, a container having excellent oxygen barrier properties can be obtained. It is a thing.

The total weight of the base paper is compared with the total weight of the high melting point thermoplastic synthetic resin layer and the inner and outer low melting point thermoplastic synthetic resin layers to determine the total weight of the base paper. Since the total weight of the resin layer is larger than that of the resin layer, the container of the present invention can be used as a paper container according to the recycling method, and the burden on recycling can be reduced and the container is excellent in economic efficiency.

Further, in the method of the present invention, since the upper flange portion is transferred while cooling during the heating transfer, good foaming of the low melting point thermoplastic synthetic resin layer of the container body member can be obtained, and foaming of the upper flange portion can be obtained. And a heat-insulating paper container suitable for a food container was obtained.

[Brief description of the drawings]

FIG. 1 is a half sectional front view showing an embodiment of a heat insulating paper container according to the present invention.

FIG. 2 is an enlarged sectional view showing an upper flange portion of the heat-insulating paper container of the present invention and an upper portion of a container body member connected to the upper flange portion.

FIG. 3 is a plan view of a traveling method of the container showing the method of the present invention.

FIG. 4 is a partial cross-sectional view showing the method shown in FIG. 3 from the side.

DESCRIPTION OF SYMBOLS 1 Container body member 2 Bottom plate member 3 Running belt 4 Belt guide member 5 Belt guide member 6 Step 7 Cooling water passage 10 High melting point thermoplastic synthetic resin layer 11 Base paper 12 Base paper 13 Low melting point thermoplastic synthesis Resin layer 14 Low melting point thermoplastic synthetic resin layer 15 Print layer 16 Upper flange part 17 Upper part 18 Inner winding edge

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) // B29K 23:00 B29L 9:00 B29L 9:00 B29C 67/22 (72) Inventor Noboru Sakata Osaka 4-1-1, Nishinakajima, Yodogawa-ku Nissin Foods Co., Ltd. (72) Inventor Hiromi Watanabe 3-4-2, Kunikubo, Fuji-shi, Shizuoka Sanyo Pax Co., Ltd. (72) Inventor Hitoshi Suzuki Shizuoka 3-4-2, Kunikubo, Fuji-shi, Japan Sanyo Pax Co., Ltd. F-term (reference) 4F100 AK01C AK01D AK01E AK06D AK06E AK07C BA05 BA06 BA10D BA10E BA13 DA04 DG10A DG10B DJ01D DJ01E HB31 JA04CJA04 J04E01 JBJ JBJ JL01 JL05 JL11 JL16 YY00C 4F212 AA04 AD05 AD06 AD08 AD20 AG03 AG20 AH55 AH56 UA09 UB01 UB11 UB22 UF05 UG05 UG07 UJ15

Claims (9)

[Claims] 1. A container body made of a raw material in which a high melting point thermoplastic synthetic resin layer is interposed between two base papers and a low melting point thermoplastic synthetic resin layer is stacked on the surface of each base paper. The container body member has an upper flange portion on the upper edge of the opening, the bottom is incorporated and integrated, and a container having a low melting point thermoplastic synthetic resin layer disposed on each of the inner and outer surfaces of the container body member is provided. A heat-insulating paper container characterized by foaming a low-melting-point thermoplastic synthetic resin layer on the inner and outer surfaces by heating. 2. The heat-insulating paper container according to claim 1, wherein an upper flange portion of an upper edge of the opening of the container body member is forcibly processed into a square cross section. 3. The heat insulating property according to claim 2, wherein an inner winding end of the upper flange portion forcibly machined into a square cross section is overlapped with an upper portion of the flange portion to form a double structure at the upper portion of the flange portion. Paper container. 4. The heat insulating paper container according to claim 1, wherein said low melting point thermoplastic synthetic resin layer is a low density polyethylene film. 5. The heat insulating paper container according to claim 1, wherein said high melting point thermoplastic synthetic resin layer is a polypropylene resin layer. 6. The method according to claim 1, wherein the high-melting-point thermoplastic synthetic resin layer has a water vapor permeability of 20 g / m ² · 24 hr or less under a measurement condition of a temperature of 40 ° C. and a humidity of 90%. 4. The heat-insulating paper container according to claim 1. 7. The high-melting thermoplastic synthetic resin layer according to claim 1, wherein the oxygen permeability is 120 cc / m ² · 24 hr or less under a measurement condition of a temperature of 20 ° C. and a humidity of 90%. 4. The heat-insulating paper container according to claim 1. 8. The total weight of the base paper is determined by comparing the total weight of the two base papers with the total weight of the high melting point thermoplastic synthetic resin layer and the inner and outer low melting point thermoplastic synthetic resin layers. The heat-insulating paper container according to any one of claims 1 to 7, wherein the container is made larger than the total weight of the resin layer. 9. A method for producing a heat-insulating paper container according to any one of claims 1 to 8, wherein the paper container is placed on a running belt with its upper flange part down, and heated while being transferred. And transferring while cooling the upper flange portion.