JPH0516283A - Container lid - Google Patents

Abstract

(57) [Summary] [Purpose] Even if the hot water is slowly poured into the container or the pouring of hot water is interrupted, the lid of the container will not be closed automatically until the hot water has not been poured. Keep the lid open to prevent the risk of burns due to boiling water spilling out of the container. [Structure] A laminated sheet in which a material having a large coefficient of thermal expansion is used as an outer layer and a material having a small coefficient of thermal expansion is used as an inner layer, and a heat-sealing resin layer is provided on the side in contact with the container
A lid used for sealing a container, and a direction in which the pulling portion for peeling the lid heat-sealed to the container via the heat-sealable resin layer from the container is started. In the lid provided at the end of the pulling portion, an easily peelable adhesive layer to which release paper is attached is provided on the surface side of the pulling portion, or in the direction in which the lid separated from the pulling portion is peeled off. A lid for a container for ready-to-eat cooked foods, which is provided with an easily peelable adhesive layer having a release paper attached to an end thereof.

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 of the container 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 by 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 foods, a polystyrene paper, a high-impact polystyrene sheet, or a laminated sheet of nylon and polyethylene, which have good heat retaining properties, is usually cup-assisted by vacuum molding or pressure-assisting. A molded product, a foam polystyrene cup obtained by in-mold bead foam molding, a container obtained by injection molding polypropylene, and the like are used. Further, as the lid used for the above-mentioned container, as shown in FIG. 8, the thickness having the printing 7 on the surface is 70 to 8
An adhesive layer 3 having a thickness of 15 to 25 μm or a urethane-based or polyester-based adhesive layer 3 obtained by extrusion-coating a 0 μm high-quality paper as a substrate layer 2 with a molten resin film of low-density polyethylene or ethylene / acrylic acid copolymer Liquid adhesive (so-called anchor coat agent) applied wall thickness 1-5μ
m adhesive layer 3, an aluminum foil layer 4 obtained by laminating an aluminum foil having a thickness of 6 to 15 μm, and a low melting point of low density polyethylene or ethylene / vinyl acetate copolymer (80 ~ 135 ° C) Extrusion laminate or resin dissolved in solvent to apply thickness of 2 to 25 μm
The laminated sheet 6 having the four-layer structure and having the heat-sealing property was used. But,
The lid of such an instant food container is such that when the lid of the container is partially opened and hot water is poured, the steam of the hot water heats the high-quality paper of the base material through the aluminum layer inside the lid, and the moisture in the high-quality paper. As a result, the high-quality paper contracts, the lid curls upward and warps back (see FIG. 6). 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

On the other hand, Japanese Utility Model Laid-Open No. 58-133574 discloses a lid for an instant food container which is composed of a composite layer in which a film having a higher heat shrinkage ratio or a film having a lower heat expansion coefficient is laminated on the inner layer. It is disclosed. According to the description in the publication, the lid of the container for instant food can be automatically closed by pouring hot water, for example, by heat shrinkage.

[0005]

However, in such a lid, if the boiling water is poured too slowly or the pouring of the boiling water is interrupted, the lid will be closed before the boiling water is completely poured, If hot water is poured further without noticing this, the hot water may fall outside the container and cause a risk of burns.

[0006]

[Means for Solving the Problems]

[Summary of the Invention] As a result of intensive studies conducted by the present inventors in view of the above-mentioned problems, the inventors have found that an outer layer made of a material having a large coefficient of thermal expansion and an inner layer made of a material having a small coefficient of thermal expansion are provided. A laminated sheet that can be self-closed by curling due to a difference in thermal expansion caused by the temperature of steam is used as a lid material, and a lid heat-sealed to the container is peeled off from the container. Form an easily peelable adhesive layer with a release paper attached on the surface of the pulling part, or
An easily peelable adhesive layer in which a release paper is attached to the end of the lid farthest from the pulling portion in the direction in which the lid is peeled off when the pulling portion is opened to open the lid. By forming the lid, the lid is bent so that the lid of the container is not closed automatically until pouring of the hot water is completed, and the lid is bent to form the lid. A part of the easily peelable adhesive layer is adhered to an end portion on the opposite side of the lid, the lid is left open, and after the pouring of hot water, the adhesive part is peeled off, The present invention has been completed based on the knowledge that the container can be automatically closed. That is, the lid of the container for instant cooked food of the present invention is formed by laminating a material having a large coefficient of thermal expansion as an outer layer and a material having a small coefficient of thermal expansion as an inner layer, and forming a heat-sealable resin layer on the side in contact with the container. A lid for use in sealing a container, comprising a laminated sheet provided with, and a pulling part for peeling the lid heat-sealed to the container via the heat-sealable resin layer from the container. In the lid provided at the end in the direction to start the peeling,
An easily peelable adhesive layer having release paper adhered to the surface side of the pulling portion is provided, or an easily peelable adhesive having release paper attached to the end of the lid in the direction of peeling. It is characterized in that an agent layer is provided.

[Detailed Description of the Invention] [I] Lid of Container (1) Structure The lid 1 of the container of the present invention is, as shown in FIG. 1, for example, an outer layer basically made of a material having a large coefficient of thermal expansion. 2 / adhesive layer 3
An easily peelable adhesive composed of a laminated sheet 6 composed of respective constituent layers of an inner layer 4 having a small coefficient of thermal expansion / a heat-sealable resin layer 5 and a release paper 2d attached to a part of the outer layer 2. The layer 2e is formed. Specifically, the expanded stretched film 2 / adhesive layer 3 having fine voids inside
/ Aluminum foil 4 / Heat-sealing resin layer 5 laminated sheet (Japanese Patent Application Nos. 3-88733 and 3-90793,
No. 3-90779 and No. 3-92439), laminate 2 / adhesive layer 3 of pulp paper and resin film
/ Aluminum foil 4 / Laminate sheet of heat sealable resin layer 5 (see Japanese Utility Model Publication No. 58-133574), non-oriented polypropylene film 2 / adhesive layer 3 / pulp paper / heat sealable resin layer 5 laminate sheet, etc. is there. Among these, a lid made of a laminated sheet 6 of a base material layer 2, an adhesive layer 3, a metal layer 4 and a heat-sealable resin layer 5 described below is preferable.

(A) Base Material Layer <Structure of Base Material Layer> As the base material layer 2 used in the lid 1 of the container, as shown in FIG. 1, a thermoplastic resin film 2a containing inorganic fine powder 8a is used. A stretched resin film 2a having a large number of fine voids 8 inside obtained by stretching at a temperature lower than the melting point of the resin, or a laminated film 2 in which the stretched resin film 2a and other resin films 2b and 2c are laminated. Is. Such a base material layer 2 specifically includes a biaxially stretched resin microporous film 2a containing an inorganic fine powder 8a, the biaxially stretched resin film as a core layer, and the inorganic fine powder 8a on one side or both sides thereof. Uniaxially stretched resin microporous film 2b, 2c (Japanese Patent Publication No. 46-4
No. 0794, Japanese Examined Patent Publication No. 63-1183), a stretched resin film 2 having a multilayer structure (see FIG. 1) can be mentioned. Of course, a resin film containing no inorganic fine powder 8a may be laminated as long as the self-closing property of the lid 1 of the container is not impaired. For example, in order to impart high gloss to the print, the surface side of the base material layer 2 to be printed does not contain substantially the inorganic fine powder 8a having a thickness of 0.2 to 8 μm (0 to 0). 3 wt%) resin film layer can be formed. An end portion 1a of the lid 1 farthest from the pulling portion 11 in the surface side of the pulling portion 11 of the lid 1 of the base material layer or in a direction α in which the lid is peeled off.
In addition, an easily peelable adhesive layer 2e having a release paper 2d adhered on the top thereof is formed.

<Material for Substrate Layer> Inorganic Fine Powder As the above inorganic fine powder, calcined clay, calcium carbonate, diatomaceous earth, titanium oxide, permculite, talc and the like can be mentioned. The particle size of the inorganic fine powder is generally 0.03 to 15 μm, preferably 0.1 to 5 μm. Thermoplastic resin Examples of the thermoplastic resin include polypropylene, polyethylene, ethylene / propylene copolymer, ethylene / buden-1 copolymer, ethylene / 4-methylpentene-1 copolymer, and propylene / ethylene / buden-1 copolymer. Polymer,
Examples thereof include polystyrene, polyethylene terephthalate, nylon-6, nylon-6,6, nylon-6,10 and nylon-6,12. Easily peelable adhesive As the easily peelable adhesive , a commonly used easily peelable adhesive can be used. Such an easily peelable adhesive generally has an adhesive strength of ²⁰ to 200 g / 15 cm ² , preferably 50 to 150 g / 15 cm ² . Specifically, an acrylic resin adhesive containing a lubricant,
A rubber adhesive or the like can be used. Release Material As the release material, a commonly used release paper can be used. Specific examples include silicone resin coated paper, polypropylene film, and synthetic paper.

<Production of Substrate Layer> The thermoplastic resin film containing the inorganic fine powder is stretched at a temperature lower than the melting point of the resin. At this time, the stretching ratio is 1.3 to 15 times, preferably 3.5 to 12 times in one direction or two directions. The number of stretching axes is uniaxial or biaxial. The specific manufacturing is
First, the resin for forming the core layer 2a is melt-kneaded, extruded into a sheet shape and cooled, and then reheated to utilize 1.3 to 15 times in the longitudinal direction by utilizing the peripheral speed difference of the roll, preferably 3.5 to It is stretched 7 times to obtain a longitudinally stretched film. Then, the resin for the front surface layer and the resin for the back surface layer are melt-kneaded using separate extruders,
Each of them is extruded into a sheet shape, laminated on the front and back surfaces of the longitudinally stretched film as a front surface layer 2b and a back surface layer 2c, respectively, and these are laminated in a transverse direction with a tenter at 1.3 to 15
The base material layer 2 is manufactured by stretching it twice, preferably 4 to 12 times.

<Physical Properties of Substrate Layer> In the lid of the porosity (void) container, the stretched resin film used for the substrate layer 2 has a large number of fine voids (porosity) 8 centered on the inorganic fine powder 8a. is doing. Such a stretched resin film has a porosity calculated by the following formula of 4 to 60%, preferably 8:
Have ~ 50%. Porosity = [(ρ ₀ −ρ) / ρ ₀ ] × 100 ρ ₀ : Density of film before stretching ρ: Density of film after stretching

Thermal expansion coefficient In order for the lid to have self-closing property, when an aluminum foil having a small thermal expansion coefficient is used for the inner layer 4, the thermal expansion coefficient (L _e ) of the base material layer is
The size of is important. The thermal expansion coefficient of such a base material layer is a thermomechanical analyzer “TM-700” manufactured by Vacuum Riko Co., Ltd.
Using 0 "(trade name), a test piece having a width of 5 mm and a length of 25 mm was fixed to a chuck, the span distance (L ₀ ) was 15 mm, and the load was 1 g.
The temperature was raised from 30 ° C. to 80 ° C. over 5 minutes at a speed of 5 minutes, and the span length (L) of the test piece at the temperature of 80 ° C. was measured. TMA method) is shown. Thermal expansion coefficient = [(L−L ₀ ) / L ₀ ] × 100 The value of this thermal expansion coefficient is 0.40 to 1.0%, preferably 0.55 to 0.85%. The value of this coefficient of thermal expansion is 1.
When it exceeds 0%, as shown in FIG. 7, the self-closing speed of the lid after pouring hot water into the container is too fast, and the contents have been steamed (before the cup noodles are ready to eat). In this case, the pulling part of the lid, which is closed too much, is excessively caught inside, and a gap 10 is formed between the container 9 and the lid 1. Further, when the value of the coefficient of thermal expansion is less than 0.40%, the time required for self-closing is too late (takes 90 seconds to 3 minutes), which causes irritation to the eater. The value of the coefficient of thermal expansion of the base material layer determined by the TMA method is a value obtained by subtracting the coefficient of thermal contraction of the stretched resin film from the coefficient of thermal expansion of the material resin of the stretched resin film.
The coefficient of thermal expansion of the base material layer is affected by the material of the resin film, the layer structure, the heat history received during film formation, the orientation, and the like. Therefore, depending on the material of the resin, the desired physical properties can be obtained by blending the inorganic fine powder with the resin, adjusting the draw ratio, drawing temperature, cooling roll pressure, temperature, and the like.
The thickness of the base material layer is also related.

Tensile Elastic Modulus The tensile elastic modulus (JIS-K7113) of the base material layer in the direction in which the tensile portion of the base material layer is provided is 10,000 to 45.0.
00 kg / cm ² , preferably 15,000 to 30,0
It is 00 kg / cm ² . Since the orientation of the base layer is exerted on the film by stretching, the elastic modulus shows a value higher than that of the unstretched resin film. Therefore, the thickness of the base material layer can be reduced.

[0014] the thickness of the substrate layer 2 used in the lid 1 of the container wall thickness invention generally 15～180Myuemu, preferably 40 to 100 [mu] m.

(B) Adhesive Layer As the adhesive layer 3 laminated on the lid 1 of the container for laminating the outer layer 2 having a large coefficient of thermal expansion and the inner layer 4 having a small coefficient of thermal expansion, which will be described later, such as an aluminum foil. , Urethane 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 Mention may be made of hot melt adhesives such as polymers.
When a coating type adhesive is used, it is generally 1 to 2
It is used in an amount of 0 g / m ² , preferably 2-6 g / m ² . In the case of a hot melt adhesive, it is melt extrusion laminated and used in a thickness of 8 to 30 μm. Such an adhesive layer is generally used in a thickness of 1 to 30 μm, preferably 2 to 15 μm.

(C) Metal Layer As the metal layer 4 used in the lid of the container, a metal foil such as an aluminum foil or an iron foil having a wall thickness of usually 3 to 25 μm can be mentioned. In particular, it is preferable to use an aluminum foil having a thickness of 6 to 15 μm from the viewpoint of handling and economical reasons. Further, from the economical aspect, the metal foil is usually used with a thickness smaller than that of the base material layer 2.

(D) Heat-sealable resin layer As the heat-sealable resin layer 5 used for heat-sealing the container 9 and the lid 1, a heat-sealable resin having a melting point lower than that of the resin constituting the base material layer 2 is used. Resin is used. Specific examples of such heat-sealable resin include low-density polyethylene, linear low-density polyethylene, and ethylene / vinyl acetate copolymer (preferably having a vinyl acetate content of 12% by weight.
The following ethylene / vinyl acetate copolymer) and ethylene / acrylic acid copolymer (preferably having an ethylene content of 65 to 9)
4% 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 / Examples thereof include a propylene copolymer, an ethylene / propylene / butene-1 copolymer, and a vinyl chloride / vinyl acetate copolymer. The heat-sealable resin layer 5 may be extrusion-laminated on a metal sheet such as an aluminum foil, or the resin may be dissolved in a solvent, coated on the aluminum foil using a coater, dried, and heat-sealed. The resin layer 5 may be provided. The heat-sealable resin layer 5 has a wall thickness of 2 to 50 μm, preferably 3 to 40 μm. The heat-sealing of the container and the lid using such a heat-sealable resin can prolong the shelf life of the food in the container. The heat-sealable resin may be extrusion-laminated on a metal sheet such as an aluminum foil, or the resin may be dissolved in a solvent, coated on the aluminum foil using a coater, and dried to obtain a heat-sealable resin. Layers may be provided.

(2) Pulling part (a) Forming position 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, but its forming position is important. Pulling part 11 of the lid 1
Is in the direction opposite to the peeling-off direction α of the lid 1, so that the self-closing property of the lid 1 is promoted, so that it is matched with the direction β in which the coefficient of thermal expansion of the base material layer 2 is large. It is desirable to provide it. If the pulling portion 11 of the lid 1 is provided so as to match the direction γ in which the value of the coefficient of thermal expansion is small, the self-closing property is deteriorated.

(B) Easily peelable adhesive layer What is particularly important in the present invention is as shown in FIG.
On the surface side of the pulling portion 11 of the lid 1, an easily peelable adhesive layer 2e having a release paper 2d adhered on the top is formed, or as shown in FIG. The direction in which the lid 1 is peeled off when the lid 1 is opened by picking
An easily peelable adhesive layer 2e having a release paper 2d attached to the end 1a of the lid farthest from the pulling portion 11
Are formed. The easily peelable adhesive layer 2e formed on the lid exhibits self-closing property because the lid 1 of the container of the present invention is composed of the laminated sheet 6, and when hot water is poured into the container 9. The lid is formed so that the heat automatically closes. However, if the hot water is slowly supplied into the container 1 or the pouring of the hot water is interrupted midway, the lid 1 of the container will be automatically closed before the pouring of the hot water is completed. Therefore, in order not to automatically close the lid 1 of the container until the boiling water is completely poured in this way, the lid 1 is bent so that the lid 1 is held in the open state. The portion of the easily peelable adhesive layer 2e formed on the lid 1 is adhered to the end portion 1a on the opposite side of the lid 1, and the lid 1 cannot be automatically closed while pouring hot water into the container 1. As described above, the lid 1 is left open. Specifically, as shown in FIG.
In the case where the easily peelable adhesive layer 2e having the release paper 2d adhered on the upper surface thereof is formed on the surface side of the pulling portion 11, the pulling portion 11 is pinched as shown in FIG. , The end 1a of the lid that is farthest from the pulling portion 11 in the direction α of peeling off the lid. Further, as shown in FIG. 4, the pulling portion 11 in the direction α in which the lid is peeled off.
When an easily peelable adhesive layer 2e having a release paper 2d adhered to the upper portion is formed on the end 1a of the lid farthest away from the cover, as shown in FIG. The release paper 2d attached to the upper portion of the agent layer 2e is peeled off to expose the easily peelable adhesive layer 2e, and the pulling portion 11 is picked on the easily peelable adhesive layer 2e to cover the lid 1. Bend and bond.
However, the lid 1 can automatically close the container 9 if the bonded portion is peeled off after pouring hot water.
Such an easily peelable adhesive layer 2e is generally 0.5 to 4c.
It is applied in an area of m ² , preferably 1-2 cm ² . Further, the release paper 2d formed on the easily peelable adhesive layer 2e is adhered in substantially the same area.

(3) Thickness The thickness of the lid 1 made of the laminated sheet 6 is generally 40 to 2
00 μm, economically 60 to 150 μm.

[II] Manufacture of container with lid (1) Heat sealing Basically, base material layer 2 / adhesive layer 3 / metal layer 4 / heat sealability, which becomes the lid 1 of the container of the present invention formed as described above. A laminated sheet 6 composed of the resin layer 5 is provided inside the dried noodles 12 and the ingredients 13
It is placed on a container 9 in which is placed and heat-sealed at a temperature of usually 100 to 160 ° C., preferably 120 to 140 ° C. for 0.1 to 3 seconds. (2) Formation of pulling part The container 9 heat-sealed to the laminated sheet 6 is a separate container 9
A substantially circular shape (for example, a diameter of 150m
The lid 1 having a protruding portion 11 (pulling portion) of about 10 mm with respect to m is trimmed. (3) Shrink wrap Next, the sealed container thus obtained is shrink-wrapped to form a product.

[III] Hot water supply When the lid 1 is opened halfway, the lid is bent and the easily peelable adhesive layer of the tension portion is adhered to the end portion on the opposite side of the lid. Keep it open and supply hot water,
If the adhesion of the lid is peeled off after the hot water is supplied, it is heated by the steam that has been supplied, and the thermal expansion of the base material layer 2 outweighs the thermal expansion of the metal layer 4 of the material forming the lid 1, and the bimetal effect automatically The lid 1 returns to the original position (see FIG. 2) and the container 9 can be sealed.

[0023]

Example 1 Production of base material layer (1) 81% by weight of polypropylene having a melt index (MI) of 0.8 (melting point of about 164-167 ° C.), 3% by weight of high-density polyethylene and an average particle size of 1. The composition (A) mixed with 16% by weight of 5 μm of calcium carbonate was treated at 270 ° C.
After kneading with the extruder set to, the sheet was extruded and cooled by a cooling device to obtain an unstretched sheet. Then, this sheet was heated again to a temperature of 150 ° C. and then stretched 5 times in the machine direction. (2) Polypropylene with MI of 0.4 (melting point about 164-1)
(67 ° C.) 54% by weight and 46% by weight of calcium carbonate having an average particle size of 1.5 μm were mixed and kneaded in another extruder, and then extruded into a sheet from a die. Was laminated on both sides of the 5-fold stretched film of (1) 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 again heated to about 175 ° C.
7. Heat up to the temperature of 7. and use a tenter to move laterally 7.
Stretched 5 times, annealed at 165 ° C,
Cooled to a temperature of 60 ° C, slit the ears, and have a three-layer structure (uniaxial stretching / biaxial stretching / uniaxial stretching), thickness 80 μm
A base material layer (B / A / B = 20 μm / 40 μm / 20 μm) was obtained. The void ratio of each layer is (B / A / B =
It was 4.6% / 13.9% / 4.6%).

Manufacture of Lid The surface of the above-mentioned base material layer is printed, and further, an anchor coating agent of urethane prepolymer is applied to the back surface side so as to be 3 g / m ^2, and an aluminum foil having a thickness of 6 μm is applied to this. Was laminated. On the aluminum foil side of this laminate, an ethylene / vinyl acetate copolymer (vinyl acetate content: 5.4% by weight) was extruded at 200 ° C. and laminated (thickness: 22%).
μm) and then cooled. This is the sheet feeding direction (M
Trimming was performed so that a tensile portion was formed in the D direction, and a substantially circular lid was obtained (diameter 150 mm, tensile portion 1).
0 mm). Formation of an easily peelable adhesive layer Peeling strength 123 g / 15 m on the surface side of the tensile portion of the lid.
A m-width acrylic resin adhesive containing a lubricant was applied at a coating amount of 4 g / m ² (15 mm width) to form an easily peelable adhesive layer. Then, a release paper was stuck on it. 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, the pulling part of the lid of the expanded polystyrene container is pulled with a finger to open 2/3 of the lid, and the release paper on the surface side of the pulling part of the lid is peeled off. Then, the easily peelable adhesive layer underneath was exposed, and this easily peelable adhesive layer was adhered to the end portion in the direction of peeling off the lid, which was separated from the pulling portion of the lid. Then, after pouring 600 cc of boiling water (temperature of about 91 ° C.) into the container from this opening for 5 seconds, the easily peelable adhesive layer of the pulling part of the lid is peeled off to remove the self-closing property (hot water supply) of the lid. After that, the time until the lid was closed) was measured. The results obtained are shown in Table 1.

Example 2 Production of base material layer (1) 81% by weight of polypropylene having a melt index (MI) of 0.8% by weight was mixed with 3% by weight of high density polyethylene and 16% by weight of calcium carbonate having an average particle size of 1.5 μm. The composition (A) was kneaded with an extruder set at 270 ° C., then 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) Composition (B) in which 54% by weight of polypropylene having an MI of 0.4 and 46% by weight of calcium carbonate having an average particle size of 1.5 μm are mixed, and 81% by weight of polypropylene having an MI of 4.0 is high density. Polyethylene 3% by weight and average particle size 1.5
The composition (C) mixed with 16% by weight of calcium carbonate (μm) is melt-kneaded by another extruder, and then melt-extruded into a sheet form from a die, which is stretched 5 times as long as (1). By laminating on both sides of the film, a laminated film having a three-layer structure was obtained. 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 165 ° 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 wall thickness of 80 μm (B / A / C = 16 μm).
A base material layer of / 48 μm / 16 μm) was obtained. The void ratio of each layer is (B / A / C = 30% / 29.7% / 3.
It was 0%). The printing surface was applied to the surface of layer B.

Formation of easily peelable adhesive layer An acrylic resin adhesive having a peel strength of 123 g / 15 mm width is 4 g / m on the surface of the end of the lid farthest in the direction of peeling the lid by the pulling portion. A coating amount of ² (15 mm width) was applied to form an easily peelable adhesive layer. Then, a release paper was stuck on it. 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 leaving for one day, the pulling portion of the lid of the expanded polystyrene container is pulled with a finger to open 2/3 of the lid, and then the pulling portion of the lid in the direction to be peeled off Peel off the release paper on the surface of the end of the separated lid, expose the easily peelable adhesive layer underneath, and bend the lid pulling part to the easily peelable adhesive layer to bond it. It was Then, after pouring 600 cc of boiling water (temperature of about 91 ° C.) from this opening into the container for 5 seconds, the easily peelable adhesive layer of the pulling part of the lid is peeled off to measure the self-closing property of the lid. did. The results obtained are shown in Table 1.

[0029]

[Table 1]

[0030]

The lid of the container of the present invention as described above can be left open so that the lid cannot be closed while pouring hot water into the container. Even if the hot water is slowly supplied to the inside or pouring of hot water is interrupted, the lid of the container will not be automatically closed before the hot water has been poured. Therefore, it is possible to prevent the risk of hot water spilling outside the container due to the automatic closing of the lid and causing burns or the like.

[Brief description of drawings]

FIG. 1 is an enlarged partial sectional view of a container lid of the present invention.

FIG. 2 is a perspective view of the lid and the container of the present invention in which an easily peelable adhesive is applied to the surface side of the pulling portion of the lid, and release paper is formed on the adhesive.

FIG. 3 is a schematic view of the container of FIG. 2 with the lid opened, the release paper on the surface side of the pulling portion is peeled off to expose the easily peelable adhesive layer, and the lid is peeled away from the pulling portion farthest away. FIG. 3 is a perspective view of the lid of the container and the container of the present invention when pouring hot water in a state of being adhered to the end portion of the lid.

FIG. 4 is a view showing the lid of the container of the present invention in which an easily peelable adhesive is applied to the end of the lid farthest from the pulling portion in the direction in which the lid is peeled off, and release paper is formed thereon. It is a perspective view.

5] The lid of the container of FIG. 4 is opened, and the release paper attached to the end of the lid farthest from the pulling part in the direction of peeling the lid is peeled off to expose the easily peelable adhesive layer. FIG. 3 is a perspective view of the lid and the container of the present invention when pouring hot water in a state where the pulling portion of the lid opened to this is bent and adhered.

FIG. 6 is a perspective view of a conventional lid and container in a state where hot water is poured into the container and the container is further opened.

FIG. 7 is a perspective view of the improper lid and the container in a state in which hot water is poured into the container and is closed too much to be curved inward.

FIG. 8 is an enlarged cross-sectional view of a conventional lid.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Container lid 2 Base material layer 2a Biaxially stretched resin microporous film 2b, 2c Uniaxially stretched resin microporous film 2d Release paper 2e Easy peelable adhesive layer 3 Adhesive layer 4 Metal layer 5 Heat sealable resin layer 6 Laminated sheet 7 Printing 8 Void 8a Inorganic Fine Powder 9 Container 10 Gap 11 Tension Part 12 Dry Noodle 13 Tool α Peeling Direction β Direction with High Thermal Expansion Coefficient γ Direction with Small Thermal Expansion Coefficient δ Direction with Pulling Section

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Funato 23, Towada, Kamisu-cho, Kashima-gun, Ibaraki Prefecture, Okaka Synthetic Paper Co., Ltd. Kashima Plant (72) Inventor Takashi Miyaji, Kashima-gun, Kashima-gun, Ibaraki Prefecture 23, Towada, Oji Oka Synthetic Paper Co., Ltd., Kashima Plant (72) Inventor, Yukio Kohama 826, Hagien, Fukuda, Chigasaki City, Kanagawa Tokai Metal Co., Ltd. Wan, 826 Hagiden, Fukuda, Chigasaki, Kanagawa Prefecture, Tokai Metals Co., Ltd., Chigasaki Plant (72) Inventor, Toshiaki Watanabe, 826, Hagien, Chigasaki, Kanagawa Prefecture, Kaigasaki, Tokai Metal Co., Ltd. (72) Inventor Chiaki Kanai 826 Fukuda, Hagien, Chigasaki-shi, Kanagawa Tokai Metal Co., Ltd. Chigasaki factory

Claims (1)

Claims: 1. A material having a large coefficient of thermal expansion is used as an outer layer and a material having a small coefficient of thermal expansion is used as an inner layer, and a heat-sealing resin layer is provided on the side in contact with the container. A lid formed of a laminated sheet, which is used for sealing a container, and which has a pulling portion for peeling the lid heat-sealed to the container via the heat-sealable resin layer from the container. In the lid provided at the end in the direction to start peeling,
An easily peelable adhesive layer having release paper adhered to the surface side of the pulling portion is provided, or an easily peelable adhesive having release paper attached to the end of the lid in the direction of peeling. A lid for a container provided with an agent layer.