JPH05170268A - Container lid - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] The lid of a half-open container is warmed by the steam supplied to the container and the container is automatically sealed. [Structure] A laminated sheet 6 including a base material layer 2, an adhesive layer 3, a base material layer 4, and a heat-sealable resin layer 5 is heat-sealed to the container via the resin layer 5 so that the lid 1 can be peeled off from the container. To The base material layer 2 forming the lid has a load of 1 g and a temperature rising rate of 10
The coefficient of thermal expansion is 0.4 to 2.0% when the temperature is raised from 30 ° C. to 80 ° C. at 5 ° C./min for 5 minutes, and the tensile elastic modulus is 5,
It is formed of a thermoplastic resin film of 000 to 50,000 kg / cm ² , and the relationship of thermal properties of the base material layers 2 and 3 satisfies the following expression. 0 <{T (A) -S (A)} + {S (B) -T (B)} <2.0 (T (A) is the coefficient of thermal expansion of the base material layer 2 in the peeling direction, S
(A) is the thermal shrinkage of the base material layer 2 in the peeling direction, T (B) is the thermal expansion coefficient of the base material layer 3 in the peeling direction, and S (B) is the heat of the base material layer 3 in the peeling direction. Shrinkage factor)

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a heat-sealing of a container for instant food such as instant cup noodles, cup sushi, cup soup, and cup miso soup, which is eaten after pouring hot water into the container and holding it for a certain period of time. Regarding the lid used.

[0002]

2. Description of the Related Art Conventionally, instant foods represented by instant cup noodles can be eaten simply by pouring hot water into a container and waiting for a few minutes (1 to 5 minutes). It is eaten in large quantities by single people, factory night workers, single employees, students, and others. In order to eat such an instant food, for example, the case of instant cup noodles will be specifically described. First, the transparent shrink packaging film packaged at the time of purchase is removed, and then the container is heat-sealed ( The pulling part of the heat-sealed lid is picked up with fingers and pulled up, and about 1/3 to 1/2 of the lid is peeled off from the container. Then, a bag containing ingredients and soup other than noodles in the container is cut with fingers, placed on the noodles, and boiling water is poured into this. After pouring hot water, the peeled lid portion is overlapped with the flange portion at the upper end of the container to close the lid, and a weight is placed on the lid so that the lid does not roll up and open, or The heat in the container is prevented from escaping by using tape or the like to improve the heat efficiency, and the contents are steamed. And
After a lapse of a predetermined time (1 to 5 minutes), the weight on the lid is removed, the rolled-up lid is pulled, the lid is completely peeled off from the container, and the contents are steamed. Can eat. As a container used for such instant food, polystyrene paper, a high-impact polystyrene sheet, or a laminated sheet of nylon and polyethylene, which has good heat-retaining properties, is usually cup-shaped by plug-assist vacuum forming or pressure forming. In-mold beads, expanded polystyrene cups obtained by foam molding, and containers obtained by injection molding polypropylene are used.

Further, as the lid used for the container,
As shown in FIG. 7, a high-quality paper having a thickness of 70 to 80 μm and having a print 7 on the surface is used as the base material layer 2, and a molten resin film of low density polyethylene or ethylene / acrylic acid copolymer is added to this. Extrusion coating thickness is 15-25μ
m thickness of the adhesive layer 3 of m or a liquid adhesive of urethane type or polyester type (so-called anchor coating agent) 1
.About.5 .mu.m adhesive layer 3, aluminum foil layer 4 having a thickness of 6 to 15 .mu.m laminated thereon, and low density polyethylene or ethylene.
A low melting point (80 to 135 ° C.) resin of vinyl acetate copolymer extruded or laminated in a solvent and applied to coat a wall thickness of 2 to 2.
A laminated sheet 6 having a four-layer structure having a heat-sealing property and composed of a heat-sealing layer 5 having a thickness of 5 μm was used.

[0004]

However, in such a lid of an instant food container, when the lid of the container is partially opened and boiling water is poured, the steam of the boiling water passes through the aluminum layer on the inside of the lid to form a base material. As a result of heating the high-quality paper and releasing the water content in the high-quality paper, the high-quality paper contracts and the lid curls upward and warps back (see FIG. 5). Therefore, the lid of an instant food container cooked with this kind of boiling water conventionally requires the trouble of pouring boiling water and then closing the lid of the opened lid by weighting the lid. It was

[0005]

[Means for Solving the Problems]

[Summary of the Invention] The inventors of the present invention have conducted intensive studies in view of the above problems, and as a result, satisfy the following formulas in the thermal properties of the base material layer (A) and the base material layer (B): <{T (A) -S (A)} + {S (B) -T (B)} <2.0 (where T (A) is the thermal expansion of the base material layer (A) in the peeling direction. Rate, S (A) is the heat shrinkage rate of the base material layer (A) in the peeling direction,
T (B) is the coefficient of thermal expansion of the base material layer (B) in the peeling direction, S
(B) represents the heat shrinkage rate of the base material layer (B) in the peeling direction. ) Furthermore, the lid of the container obtained by selecting the base material layer (B) as a specific material so as to have a specific rigidity as the lid is a container The present invention has been completed by discovering that the present invention can be closed.

That is, the lid of the container of the present invention comprises a base material layer.
(A) / adhesive layer / base material layer (B) / a heat-sealable resin layer laminated sheet, which is a lid used for sealing the container, and which has the heat-sealable resin layer on the container,
The lid is provided with a pulling portion at the end for peeling the heat-sealed lid from the container, or a lid on the surface of which the direction of peeling from the container is indicated by printing. The base material layer (A) that composes the above has a load of 1 g and a temperature rising rate of 10 ° C./min for 5 minutes from a temperature of 30 ° C. to 80 ° C.
The coefficient of thermal expansion when heated to the temperature of 0.4 to 2.0
%, The tensile modulus is 5,000 to 50,000 kg / c
The base material layer formed of a thermoplastic resin film of m ^2.
It is characterized in that the relation of thermal properties between (A) and the base material layer (B) satisfies the following formula. 0 <{T (A) -S (A)} + {S (B) -T (B)} <2.0 (where T (A) is the heat of the base material layer (A) in the peeling direction) Expansion rate, S (A) is the heat shrinkage rate of the base material layer (A) in the peeling direction,
T (B) is the coefficient of thermal expansion of the base material layer (B) in the peeling direction, S
(B) represents the heat shrinkage rate of the base material layer (B) in the peeling direction. )

[Detailed Description of the Invention] [I] Container Lid (1) Structure The container lid 1 of the present invention is, for example, as shown in FIG. 1, a base basically made of a material having a large coefficient of thermal expansion. The laminated sheet 6 is composed of the material layer (A) 2, the adhesive layer 3, the base material layer (B) 4 having a small coefficient of thermal expansion 4, and the heat-sealable resin layer 5. Specifically, a laminated sheet of resin film 2 having fine voids inside / adhesive layer 3 / pulp paper 4 / heat-sealable resin layer 5, resin film 2 having fine voids inside / adhesive layer 3 / resin Laminated sheet of film 4 / heat-sealable resin layer 5, or non-oriented polypropylene film 2 / adhesive layer 3 / pulp paper 4 / heat-sealable resin layer 5, non-oriented polypropylene film 2 / adhesive layer 3
/ Resin film 4 / heat-sealable resin layer 5 laminated sheet and the like.

(A) Base Material Layer (A) The base material layer (A) 2 used in the lid 1 of the container of the present invention is composed of a thermoplastic resin film having a surface printed as described above. ing. This thermoplastic resin film has a tensile elastic modulus of 5,000 to 50,000 kg.
/ Cm ² , preferably 6,500-46,000 kg /
It shows cm ² . The tensile modulus is 5,000k
If it is less than g / cm ² , the lid tends to warp inward when pouring into the container. This thermoplastic resin film has a coefficient of thermal expansion in the direction in which the lid is peeled off (after setting the load of the film to 1 g, the temperature is raised from 30 ° C to 80 ° C over 5 minutes at a heating rate of 10 ° C / minute). The value of the coefficient of thermal expansion when the temperature is raised to 0.4 to 2.0%, preferably 0.55 to 1.
It must be within the range of 70%. If the coefficient of thermal expansion is less than 0.4%, it will not close or the time required for closing will be too long (90 seconds to 3 minutes) to irritate the eater, and If the content exceeds 2.0%, as shown in FIG. 6, the self-closing speed of the lid after pouring hot water into the container is too slow and the contents are completely steamed (before the cup noodles are ready for eating). If it is closed too much, the pulling part 11 of the lid is excessively caught inside, and a gap 10 is formed between the container 9 and the lid 1.
Is occurring. Furthermore, 8 of this thermoplastic resin film
It is preferable that the heat shrinkage ratio at free standing at 0 ° C. is 0.4% or less. If the heat shrinkage exceeds 0.4%, after pouring hot water, the self-closing lid cannot maintain its shape retention property and the lid is closed before the contents are steamed (before the cup noodles are ready to eat). Curls up (on the side opposite the container). Examples of the thermoplastic resin film used as the material of the base material layer (A) 2 include polypropylene, polycarbonate, polyphenylene ether, ethylene / propylene copolymer, propylene / 4-methylpentene-1 copolymer, propylene / ethylene / Butene-1 copolymer, polystyrene, polyethylene terephthalate, nylon-
6, Nylon-6,6, Nylon-6,10, Nylon-6,12, saponified ethylene-vinyl acetate copolymer and the like can be mentioned.

(B) Adhesive Layer Urethane is used as the adhesive layer 3 laminated to bond the base material layer (A) 2 and the base material layer (B) 4 described later in the lid 1 of the container of the present invention. Prepolymer, liquid polyester, isocyanate type, polyester isocyanate type, polyether isocyanate type, polyethyleneimine type, organic titanate type anchor coating agent, low density polyethylene, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer Hot melt adhesives such as Such an adhesive layer 3 is generally 1
It is used in a thickness of -30 μm, preferably 2-15 μm. Specific adhesive coating type in manner is from 1 to 20 g / m ^2, and preferably applied in an amount of 2 to 6 g / m ^2. Hot melt type adhesive is melt extrusion laminated, 8 ~ 30μ
m, preferably 10 to 25 μm in thickness.

(C) Base material layer (B) The base material layer (B) 4 constituting the lid 1 of the container of the present invention includes:
In the thermal properties with the above-mentioned base material layer (A) 2, the following formula is satisfied, and 0 <{T (A) -S (A)} + {S (B) -T (B)} <2.0 (Where T (A) is the coefficient of thermal expansion of the base material layer (A) in the peeling direction, S (A) is the coefficient of thermal contraction of the base material layer (A) in the peeling direction,
T (B) is the coefficient of thermal expansion of the base material layer (B) in the peeling direction, S
(B) represents the heat shrinkage rate of the base material layer (B) in the peeling direction. ) Further, the base material layer (B) 4 has a Taber stiffness value (JIS-
It was measured by P8125. ) Is 0.06 to 75 g / c
m ² , preferably 0.06 to 65 g / cm ² of paper-like substance, or Taber stiffness value (measured by JIS-P8125) of 0.1 to 75.0 g / cm ² , preferably 0.4 to It is desirable to show 65 g / cm ² of plastic. Specific examples of the paper-like substance include thin paper, glassine paper, high-quality paper, coated paper, pulp paper such as drawing paper. Specific examples of the above plastics include polypropylene, high-density polyethylene, linear polyethylene, polycarbonate, polyphenylene ether, ethylene / propylene copolymer, propylene / 4-methylpentene-1 copolymer, propylene / ethylene / butene- 1 copolymer, polystyrene, polyethylene terephthalate, nylon-6, nylon-
Stretched or non-stretched film or sheet of thermoplastic resin such as 6,6, nylon-6,10, nylon-6,12, saponified ethylene / vinyl acetate copolymer, vinyl chloride, and the above thermoplastic resin. Examples thereof include stretched or non-stretched plastic film / sheet containing inorganic fine powder.

(D) Heat-sealable resin layer The heat-sealable resin layer 5 used for heat-sealing the container and the lid in the present invention has a melting point lower than that of the resin of the base material layer (A) 2. A heat sealable resin is used.
Specific examples of such heat-sealable resin include low density polyethylene, linear low density polyethylene, ethylene
Vinyl acetate copolymer (preferably having a vinyl acetate content of 12
Up to wt% ethylene / vinyl acetate copolymer), ethylene / acrylic acid copolymer (preferably having an ethylene content of 6)
5 to 94% by weight of ethylene / acrylic acid copolymer), ethylene / methacrylic acid alkyl ester copolymer, ionomer (metal salt of ethylene / acrylic acid copolymer, metal salt of ethylene / methacrylic acid copolymer), ethylene·
Propylene copolymer, ethylene-propylene-butene-
1 copolymer, vinyl chloride / vinyl acetate copolymer and the like. The thickness of the heat-sealable resin layer 5 is generally 2 to 50 μm, preferably 3 to 40 μm. The heat-sealing of the container 9 and the lid 1 using such a heat-sealable resin can prolong the storage period of the food in the container 9.

(E) Lid As shown in FIG. 1, the lid 1 of the container of the present invention is basically a base material layer (A) 2 / adhesive layer 3 / base material layer (B) 4 / heat sealable resin. The laminated sheet 6 is composed of the constituent layers of the layer 5, and the thickness thereof is generally 40 to 450 μm, preferably 60 to 380 μm. The thickness of this lid 1 is 40 μm
If it is less than the above, not only the rigidity of the lid 1 cannot be maintained, but also when the container 1 is filled with molten metal and closed by itself, the rigidity is too small and the lid 1 warps inward. On the other hand, if it exceeds 450 μm, the rigidity is too high and the lid does not automatically close when the molten metal is poured into the container 9. The thickness of the base material layer (A) 2 used in the structure of the lid 1 is generally 15 to 180 μm,
The thickness of the base material layer (B) 4 is preferably 20 to 100 μm,
Generally 15 to 400 μm, preferably 20 to 350 μm
And the thickness ratio of the base material layer (A) 2 and the base material layer (B) 4 is 0.03 <the thickness of the base material layer (A) / the thickness of the base material layer (B) Often used in the thickness <12 range.

<Coefficient of Thermal Expansion> In the lid 1 of the container of the present invention, the coefficient of thermal expansion (T (A)) of the thermoplastic resin film of the base material layer (A) 2 is important. The coefficient of thermal expansion was measured by using a thermomechanical analyzer "TM-7000" (trade name) manufactured by Vacuum Riko Co., Ltd., using a test piece with a width of 5 mm and a length of 25 mm, which was fixed to a chuck and spanned. Set the distance (L ₀ ) to 1
After setting the load to 5 mm and the load to 1 g, the temperature was raised from 30 ° C. to 80 ° C. over 5 minutes at a heating rate of 10 ° C./min, and the span length of the test piece at the temperature of 80 ° C. ( L)
Is measured and the value (TMA method) obtained by the following equation is shown. Thermal expansion coefficient (%) = [(L−L ₀ ) / L ₀ ] × 100

<Heat Shrinkage> Yama set at 80 ° C.
Using To Fine Oven (trade name), the heat shrinkage was measured after leaving it at 80 ° C. for 30 minutes under free heat shrinkage (%) = {(S0 −S) / S0} × 100 [S0 in the formula is free The measured value before standing and S represents the measured value after standing for free. ]

(2) Tear-off direction of lid In the lid 1 of the container of the present invention, as shown in FIG.
A pulling portion 11 for peeling off the lid 1 is provided, or a display 8 for instructing the peeling direction α is printed 7 on the lid as shown in FIG. The position where the pulling portion 11 is formed or the printed direction of the display 8 that indicates the peeling direction α is important in the present invention. Peeling direction α indicated by the pulling portion 11 of the lid 1 or the display 8
Since it coincides with the peeling direction α of the lid 1, it promotes the self-closing property of the lid 1. Therefore, the base layer (A) 2 and the base layer
(B) It is desirable that the thermal properties of 4 should be set so that they satisfy the following formula. 0 <{T (A) -S (A)} + {S (B) -T (B)} <2.0 (where T (A) is the thermal expansion of the base material layer (A) in the peeling direction) Rate, S (A) is the heat shrinkage rate of the base material layer (A) in the peeling direction,
T (B) is the coefficient of thermal expansion of the base material layer (B) in the peeling direction, S
(B) represents the heat shrinkage rate of the base material layer (B) in the peeling direction. )

[II] Production of Container with Lid (1) Heat Seal Basically, the base material layer (A) 2 / adhesive layer 3 / base material layer (which becomes the lid 1 of the container of the present invention formed as described above, B) A laminated sheet 6 composed of 4 / heat-sealable resin layer 5 is placed inside the dried noodles 1
2, put on the container 9 containing the ingredient 13, usually 100-1
0.1 to 60 ° C., preferably 120 to 140 ° C.
Heat sealed in 3 seconds. (2) Printing On the surface of the base material layer (A) 2 of the laminated sheet 6, the content marking, manufacturer, manufacturing date, etc. are offset-printed or gravure-printed. When the pulling portion 11 is not formed, the printing 7 that indicates the peeling direction α of the lid 1 is performed as shown in FIG. (3) Forming a tensile portion The container 9 heat-sealed to the laminated sheet 6 is a separate container 9
A substantially circular shape (for example, a diameter of 150 mm) in which a protruding portion 11 is formed in part in order to form a tensile portion 11 by separating each piece.
On the other hand, the lid 1 having the protruding portion 11 (tensile portion) of about 10 mm) is trimmed. (4) Shrink packaging Next, the sealed container 9 thus obtained is shrink-wrapped to form a product.

[III] Hot Water Supply The lid 1 that has been half-opened is heated by the steam that has been supplied, and the base material layer (B) 4 constituting the lid 1 is expanded by heat to the base material layer (A).
The thermal expansion of the thermoplastic resin film 2 is better, and the bimetal effect allows the lid 1 to automatically return to the original position (see FIG. 2) to seal the container 9.

[0018]

【Example】

Example 1 Production of base material layer (A) Non-stretched polypropylene film "Pyrene film" manufactured by Toyobo Co., Ltd. (trade name; wall thickness 40 μm, tensile elastic modulus (MD direction) 8,100 kg / m ² , (TD direction) ) 7,
800 kg / m ² , thermal expansion coefficient (MD direction) 1.25
%, (TD direction) 1.63%, the heat shrinkage ratio after free standing at 80 ° C. for 30 minutes (MD direction) 0.04%, (TD direction) 0.14% were used as the base material layer (A). .. Manufacture of base material layer (B) Using the drawing paper “Fuji” (trade name, basis weight 186.7 g, Taber rigidity value 34.0 g / cm) manufactured by Daishowa Paper Manufacturing Co., Ltd. as base material layer (B) did.

Manufacture of Lid The surface of the above-mentioned base material layer is printed, and further, 3 g of a urethane prepolymer anchor coating agent is applied to the back surface side of this base material layer.
It was applied so as to be m ^2, and the base material layer (B) was laminated thereon. Ethylene / vinyl acetate copolymer (vinyl acetate content 5.4% by weight) on the base material layer (B) side of this laminate
Was subjected to extrusion lamination (wall thickness: 22 μm) at 200 ° C. and then cooled. This was trimmed so that a tensile portion was formed in the sheet feeding direction (MD direction) to obtain a substantially circular lid (diameter 150 mm, tensile portion 10 mm). 250 g of dried noodles and 25 g of ingredients were put in a container made of expanded polystyrene having a heat seal content of 1,000 cc and a diameter of about 150 mm, and the lid was heat-sealed by applying pressure at 140 ° C. for 0.5 seconds. Evaluation After standing for one day, pull the pulling part of the lid of the expanded polystyrene container with a finger to open 2/3 of the lid, and boil 600 cc of hot water (temperature of about 91 ° C) from this opening. It was poured into the container for 5 seconds to measure the self-closing property of the lid (time after hot water is supplied before closing the lid) and the shape retention property (presence or absence of curl after self-closing). The results obtained are shown in Table 1.

Example 2 Instead of the drawing paper “Fuji” manufactured by Daishowa Paper Co., Ltd. as the base material layer (B) in Example 1, a high-quality paper “Kinmari” manufactured by Hokuetsu Paper Co., Ltd. (trade name, 90 g of basis weight, Taber rigidity value of 7.5 g / cm) and high-quality paper "Kinmari" (trade name, 135 g of basis weight, Taber rigidity value of 15.0 g / cm) were pasted together using a polyether isocyanate adhesive. The same procedure as in Example 1 was performed except that a laminating paper (Taber rigidity value 62.5 g / cm) was used. The results obtained are shown in Table 1.

Example 3 In Example 1, as the base material layer (B), Daishowa Paper Manufacturing Co., Ltd.
Thin paper manufactured by Sanko Paper Co., Ltd. instead of the drawing paper "Fuji" manufactured by Sanko Paper Co., Ltd. (grammage 14g, Taber rigidity 0.06g / cm)
Was carried out in the same manner as in Example 1 except that The results obtained are shown in Table 1.

Example 4 In Example 1, a heat-treated product (80 ° C., 1 hour) of a stretched polypropylene film “Pyrene film” (trade name) manufactured by Toyobo Co., Ltd. (80 ° C., 1 hour) (wall thickness 40 μm, tensile modulus (MD)
Direction) 21,100 kg / cm ² , (TD direction) 45,
500 kg / cm ² , coefficient of thermal expansion (MD direction) 0.73
%, (TD direction) 0.12%, the heat shrinkage ratio after free standing at 80 ° C. for 30 minutes (MD direction) 0.00%, (TD direction) 0.00% was used as the base material layer (A). , Hokuetsu Paper Co., Ltd. high-quality paper "Kinmari" (brand name, basis weight 135g) as the base material layer
The same procedure as in Example 1 was carried out except that it was used as (B).

Example 5 Production of base material layer (A) (1) 81% by weight of polypropylene having a melt index (MI) of 0.8% by weight, 3% by weight of high-density polyethylene and 16% by weight of calcium carbonate having an average particle size of 1.5 μm % Of the composition (A) was kneaded by an extruder set at 270 ° C., extruded into a sheet, and cooled by a cooling device.
An unstretched sheet was obtained. Then, this sheet was heated again to a temperature of 140 ° C. and then stretched 5 times in the machine direction.
(2) A composition (B) prepared by mixing 54% by weight of polypropylene having MI of 4.0 and 46% by weight of calcium carbonate having an average particle size of 1.5 μm was kneaded in another extruder, and then this was die-cast. It was extruded into a sheet and laminated on one side of the (1) 5-fold stretched film to obtain a laminated film having a three-layer structure.
Then, after cooling the laminated film having the three-layer structure to 60 ° C., it is heated again to a temperature of about 160 ° C., stretched 7.5 times in the transverse direction using a tenter, and annealed at a temperature of 170 ° C. Then, it is cooled to a temperature of 60 ° C. and the ears are slit to form a three-layer structure (uniaxially stretched / biaxially stretched / uniaxially stretched) having a thickness of 60 μm (B / A / B = 16 μm / 48).
A substrate layer (A) having a thickness of μm / 16 μm) was obtained. Example 4 was carried out in the same manner as in Example 4 except that the three-layer laminated film produced by the above production method was used as the base material layer (A). The results obtained are shown in Table 1.

Example 6 An unstretched polypropylene film "Pyrene film" (trade name) manufactured by Toyobo Co., Ltd. was used as the base material layer (A), and Oji Petrochemical Synthetic Paper (trade name) was used as the base material layer (B). Incorporated inorganic filler-containing polypropylene laminated stretch film "YUPO FPG-60"
The same procedure as in Example 1 was carried out except that (trade name) was used and the trimming direction of the lid was changed from the MD direction to the TD direction.
The results obtained are shown in Table 1.

Example 7 As the base material layer (A), an unstretched polypropylene film "Pyrene film" (trade name) manufactured by Toyobo Co., Ltd. was used, and as the base material layer (B), the base material of Example 5 was used. The procedure of Example 1 was repeated except that the layer (A) was used. The results obtained are shown in Table 2.

Example 8 In Example 7, except that an inorganic filler-containing polypropylene laminated stretched film "YUPO FPG-300" (trade name) manufactured by Oji Yuka Synthetic Paper Co., Ltd. was used as the base material layer (B). The same procedure as in Example 7 was performed. The results obtained are shown in Table 2.

Comparative Example 1 As the base material layer (A), a laminated stretched film produced at 165 ° C. instead of 170 ° C. in the production of the base material layer (A) of Example 5 was used. The layer (B) was prepared in the same manner as in Example 1 except that an aluminum foil (wall thickness: 6 μm) manufactured by Toyo Aluminum Foil Co., Ltd. was used. The results obtained are shown in Table 2.

Comparative Example 2 The base material layer (A) was an unstretched polypropylene film “Taiko FHK2” (trade name; wall thickness 60 μm, manufactured by Nimura Sansho Co., Ltd.).
m, tensile elastic modulus (MD direction) 8,200 kg / cm ² ,
(TD direction) 8,720 kg / cm ² , thermal expansion coefficient (M
D direction) 2.33%, (TD direction) 1.69%, 80 ° C
After 30 minutes of free standing, the heat shrinkage is (MD direction) 0.0
Comparative Example 1 except that 4% and (TD direction) 0.14% were used
It carried out similarly to. The results obtained are shown in Table 2.

Comparative Example 3 As the base material layer (A), an unstretched polypropylene film “Pyrene film” (trade name) manufactured by Toyobo Co., Ltd. was used, and as the base material layer (B), manufactured by Hokuetsu Paper Mills Co., Ltd. Quality paper "Kinmari"
(Product name, basis weight 135g, Taber rigidity value 15.0g /
cm), and a laminated paper (Taber rigidity value 79.7) that is obtained by sticking together two sheets using a polyether isocyanate-based adhesive.
The same procedure as in Example 1 was carried out except that (g / cm) was used. The results obtained are shown in Table 2.

Comparative Example 4 The base material layer (A) was coated paper “Cormorant” manufactured by Fuji Kako Co., Ltd. (trade name, basis weight 74 g, Taber rigidity value 1.6).
g / cm), the base material layer (B) has a polyethylene shrink film (thickness 15 μm, tensile elastic modulus (MD direction) 11,
850 kg / cm ² , (TD direction) 6,400 kg / c
m ² , thermal expansion coefficient (MD direction) -1.87%, (TD direction) 0.00%, thermal shrinkage ratio (MD direction) 3.51% when left free at 80 ° C. for 30 minutes, ( TD direction) 0.61
The same procedure as in Example 1 was carried out except that% was used. The results obtained are shown in Table 2.

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

EFFECTS OF THE INVENTION The lid of the container of the present invention as described above is heated by the steam supplied to the container, whereby the bimetal effect works and the container can be automatically sealed. There is no need to close the lid after the hot water is supplied and put a weight on it.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a lid of a container according to the present invention.

FIG. 2 is a perspective view of the lid and the container of the present invention in a state where hot water is poured into the container and the lid is automatically closed.

FIG. 3 is a perspective view of the lid and the container of the present invention in a state in which the lid is opened, tools are put in the container, and hot water is not poured.

FIG. 4 is a perspective view of the container lid and the container of the present invention in which boiling water is poured into the container and a display for instructing a peeling direction is printed on the container lid in a state where the lid is automatically closed. is there.

FIG. 5 is a perspective view of a conventional lid and container in a state where hot water is poured into the container and is further opened.

FIG. 6 is a perspective view of an improper lid and container in a state in which hot water is poured into the container and is closed too much and curved inward.

FIG. 7 is an enlarged cross-sectional view of a conventional lid.

[Explanation of symbols]

 1 Lid of container 2 Base material layer (A) 3 Adhesive layer 4 Base material layer (B) 5 Heat-sealable resin layer 6 Laminated sheet 7 Printing 8 Indication indicating peeling direction 9 Container 10 Gap 11 Tension part 12 Dry noodle 13 Tool α Peeling direction

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Miyaji 23, Towada, Kamisu-cho, Kashima-gun, Ibaraki Prefecture Okaka Synthetic Paper Co., Ltd. Kashima Plant

Claims (3)

[Claims] 1. A lid which is composed of a laminated sheet of a base material layer (A) / adhesive layer / base material layer (B) / heat-sealable resin layer and is used for sealing a container, and which has the heat-sealability. By printing the direction of peeling from the container on the lid or the surface of the lid which has a pulling part at the end for peeling the heat-sealed lid from the container through the resin layer With the indicated lid, the base material layer (A) constituting the lid was heated with a load of 1 g from a temperature of 30 ° C. to a temperature of 80 ° C. over 5 minutes at a heating rate of 10 ° C./min. Coefficient of thermal expansion is 0.4 to 2.0%, and tensile elastic modulus is 5,000 to 50,
It is formed of a thermoplastic resin film of 000 kg / cm ² , and the relationship of thermal properties between the base material layer (A) and the base material layer (B) satisfies the following formula: The lid of the container to be used. 0 <{T (A) -S (A)} + {S (B) -T (B)} <2.0 (where T (A) is the heat of the base material layer (A) in the peeling direction) Expansion coefficient, S (A) is the thermal contraction rate of the base material layer (A) in the peeling direction, T (B) is the thermal expansion coefficient of the base material layer (B) in the peeling direction, and S (B) is the peeling rate. Represents the heat shrinkage of the base material layer (B) in the direction.) 2. A Taber rigidity value in the peeling direction (measured by JIS-P8125) of the base material layer (B) of 0.06 to 7
The lid of the container according to claim 1, wherein a paper-like material of 5.0 g / cm ² is used. 3. The base layer (B) has a Taber stiffness value in the peeling direction (measured by JIS-P8125) of 0.1 to 75.
The container lid according to claim 1, wherein 0 g / cm ² of plastic is used.