JPH05305976A - Lid for container - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a lid for a self-closing container with increased safety, in which the lid does not automatically close during hot water supply and the lid is closed with a hand after hot water is supplied. [Structure] A lid comprising a laminated sheet of a base material layer / adhesive layer / metal layer / heat-sealable resin layer, the lid being used for sealing a container, and the lid having the heat-sealable resin layer interposed therebetween. In the lid of a container having a pulling portion at the end for peeling the lid from the container when heat-sealed to the container or the lid of the container in which the peeling direction is printed, the base material layer is fine inside. Formed by a single layer of a stretched resin film having a large number of voids or a layer composed of a laminated sheet containing a stretched resin film having a large number of fine voids inside,
The position formed on the lid portion of the pulling portion or the printed peeling direction is the temperature rising rate 10 of the base material layer of the lid portion.
A lid for a container, which is provided so as to match the direction of a smaller coefficient of thermal expansion when the temperature is raised from 30 ° C. to 80 ° C. over 5 minutes at a rate of 5 ° C./min.

Description

Detailed Description of the Invention

[0001]

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

[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 a lid used for the above-mentioned container, as shown in FIG.
80 μm high-quality paper is used as the base material layer 2, and a molten resin film of low-density polyethylene or ethylene / acrylic acid copolymer is extrusion-coated onto the base material layer 2, and the adhesive layer 3 having a thickness of 15 to 25 μm or urethane-based or polyester-based Liquid adhesive (so-called anchor coat agent) applied wall thickness 1-5μ
m of the 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 (on the aluminum foil layer 4 ( 80 to 135 ° C.) Extrusion laminate or resin dissolved in solvent and applied to a thickness of 2 to 25 μ
The laminated sheet 1 having a four-layer structure having heat-sealing properties, which is composed of the heat-sealing layer 5 of m, was used. However, the lid of such an instant food container is such that when the lid of the container is partially opened and boiling water is poured, the steam of the boiling water heats the woodfree paper of the base material through the aluminum layer inside the lid, and As a result, the woodfree 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, in Japanese Utility Model Laid-Open No. 58-133574, a heat-shrinkable film made of polyethylene or nylon, which has a higher heat shrinkage ratio or a lower heat expansion coefficient than the outer layer of aluminum foil or paper, is disclosed. Disclosed is a lid for an instant food container, which is composed of a composite layer in which inner layers of the above are laminated. 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.
However, if such a lid is slowly poured with hot water or if pouring hot water is interrupted in the middle, the lid will be closed before the hot water has been poured, and the hot water will continue to be hot water. If is poured, the boiling water may bounce over the lid of the container, causing a risk of burns. Further, as shown in Comparative Example 2 described later, after the lid is automatically closed, the lid curls inward and the container cannot be completely closed (see FIG. 7).

As a result of intensive studies conducted by the present inventors in view of the above problems, the steam between the outer layer made of a material having a large coefficient of thermal expansion and the inner layer made of a material having a small coefficient of thermal expansion is steamed. Using a laminated sheet that can be self-closed by curling due to the difference in thermal expansion caused by the temperature, the lid that is heat-sealed to the container is peeled off by pulling on the pulling part. By forming a locking portion at the end of the lid to fold the lid and lock the pulling portion to prevent the lid from closing, the lid of the container will automatically be closed until hot water is not poured. The lid can be held open so that it will not be closed, and the lid of the container will automatically close if the locking part is released after pouring hot water. I got the knowledge that I can
A lid, which is composed of a laminated sheet of a base material layer / adhesive layer / metal layer / heat-sealable resin layer, and is used for sealing a container, and the lid is attached to the container via the heat-sealable resin layer. In a container lid having a pulling part at the end for peeling the lid from the container when heat-sealed, the base material layer is a single layer or the inside of a stretched resin film having a large number of fine voids therein. Is formed of a layer made of a laminated sheet containing a stretched resin film having a large number of fine voids, and the position formed on the lid part of the tension part is at a temperature rising rate of 10 ° C./min of the base material layer of the lid part. 80 ° C for 5 minutes from 30 ° C
A lid of a container is proposed which is provided so as to match the direction in which the coefficient of thermal expansion is large when the temperature is raised to a temperature of ° C (Japanese Patent Application No. 3-88733). The lid of this container is a cup noodle (container content of 1,000 cc) The lid of the container is peeled off from a part of the container, and when pouring into the container, the lid automatically opens within 18 to 130 seconds after pouring. Has the advantage of closing. However, in the above-mentioned container for instant food, the content of the container is 200 cc to 1,500 cc.
And there are many kinds, and the lid closing speed is 5 to 15 according to it.
It turned out that there was a danger that the lid during the hot water supply automatically closed the container, and the hot water during the hot water bounced over the lid and became dangerous.

[0006]

SUMMARY OF THE INVENTION According to the present invention, the lid does not close on the container while hot water is supplied to the container, and the lid is lightly closed with hands after the hot water is supplied. It is intended to provide a container lid that automatically closes.

[0007]

The present invention is a lid which is composed of a laminated sheet of a base material layer / adhesive layer / metal layer / heat-sealable resin layer and is used for sealing a container, and the lid is A lid of a container provided with a pulling part at an end portion for peeling the lid from the container when heat-sealed to the container via the heat-sealable resin layer or a lid of the container in which the peeling direction is printed. In the above, the base material layer is formed of a single layer of a stretched resin film having a large number of fine voids inside or a layer formed of a laminated sheet containing a stretched resin film having a large number of fine voids inside, and a lid of the pulling portion. The position where the substrate is formed or the printed peeling direction is 30 at a temperature rising rate of the base material layer of the lid portion of 10 ° C./min for 5 minutes.
The present invention provides a lid for a container, which is provided so as to match the direction in which the coefficient of thermal expansion is small when the temperature is raised from a temperature of 80 ° C to a temperature of 80 ° C.

[0008]

[Function] After the hot water is supplied into the container, the lid of the container tries to close due to the bimetal effect, but the thermal expansion of the base material in the direction in which the coefficient of thermal expansion is large overcomes the thermal expansion in the direction in which it is small, and the lid is automatically closed. Is prevented. After hot water is supplied, gently put your hand on the lid and close it so that it touches the edge of the container, or if you touch the edge of the container and release your hand, the distance between the steam and the lid will decrease, The amount of heat effectively acts on the lid, and the lid can close the container in about 1 to 5 seconds.

[Detailed Description of the Invention] [I] Container Lid (1) Structure As shown in FIG. 1, the container lid 1 of the present invention basically has the following base material layer 2 / adhesive layer. 3 / Metal layer 4 / Heat-sealing resin layer 5 is included in the laminated sheet 6.

(A) Substrate Layer As the substrate layer 2 used in the lid 1 of the container of the present invention, as shown in FIG. 1, a thermoplastic resin film 2a containing an inorganic fine powder 7 is formed from the melting point of the resin. The stretched resin film 2a having a large number of fine voids 8 inside obtained by stretching at a low temperature is a stretched resin film 2a alone or a laminated film 2 in which the stretched resin film 2a and other resin films 2b and 2c are laminated. As such a base material layer 2, specifically, a biaxially stretched resin microporous film 2a containing 5 to 30% by weight of an inorganic fine powder 7, a biaxially stretched resin film as a core layer, and one side or both sides thereof Inorganic fine powder 7 to 8-6
Uniaxially stretched resin microporous film 2b, 2 containing 5% by weight
c (Japanese Patent Publication No. 46-40794, Japanese Patent Publication No. 63-1183)
Stretched resin film 2 having a laminated structure
(See FIG. 1). Of course, a resin film containing no inorganic fine powder 7 may be laminated as long as the self-closing property of the lid 1 of the container of the present invention 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 has a thickness of 0.
It is possible to form a resin film layer that does not substantially contain the inorganic fine powder 7 of 2 to 8 μm (0 to 3% by weight).

The base material layer is made of a uniaxially stretched resin film containing an inorganic fine powder containing a uniaxially stretched resin film, and has a large number of fine voids inside. Laminate comprising a core layer composed of a film and a laminate comprising a thermoplastic resin film back surface layer having voids having a void ratio lower than the surface void ratio even if there is no minute void inside the film It may be the body. Furthermore, the base material layer has a large number of fine voids inside the film made of a stretched thermoplastic resin film containing 8 to 65% by weight of inorganic fine powder (excluding scale-like inorganic fine powder), and is printed on the surface. 5 to 70% by weight of the surface layer 2'b that has been subjected to
It may be composed of a laminate containing at least two layers of a back surface layer made of the contained thermoplastic resin film. (See FIG. 9) The surface layer 2′b is a thermoplastic resin containing 8 to 65% by weight, preferably 20 to 55% by weight, of inorganic fine powder (excluding scale-like inorganic fine powder) 7 for printing. It is formed of a stretched film of resin. When the content of the inorganic fine powder is 8% by weight or less, improvement in printability cannot be expected, fine voids 8 are less likely to occur inside the film, and not only the effect of reducing the weight of the base material layer 2 is absent but also the number of voids 8 is small. After the lid receives the heat of steam and returns to the one before being peeled off by the bimetal effect, the lid 1 further curls inward, and a gap 10 is formed between the lid 1 and the container 9 as shown in FIG. Will end up. Further, if the inorganic fine powder 7 exceeds 65% by weight, it is impossible to fill the inside of the thermoplastic resin film with this kind of powder. Since the inorganic fine powder (excluding scaly inorganic fine powder such as talc and mica) 7 used here has a spherical particle size or a rough surface, it is a thermoplastic resin containing the inorganic fine powder 7. When the resin film is stretched at a temperature lower than the melting point of the film, a large number of fine voids 8 are formed inside the film with the inorganic fine powder as a core. The porosity of the surface layer 2'b (defined later) is generally 4
˜55%, preferably 8-45%. The back surface layer 2'c is formed of a thermoplastic resin film containing 5 to 70% by weight, preferably 15 to 65% by weight of scale-like inorganic fine powder. The larger the content of the scale-like inorganic fine powder, the higher the flexural modulus of the base material layer 2 and the thinner the base material layer 2.

Further, the thermoplastic resin film layer containing the scale-like inorganic fine powder of the back surface layer may or may not be stretched, but if it is stretched, the substrate layer is thinner and has higher strength. It can be 2. The back layer 2'c generally has a porosity of 0 to 12%, which is smaller than that of the front layer 2'b. Since the flaky inorganic fine powder 9 has a flat shape, even if it is blended in a thermoplastic resin and stretched, it is difficult for the fine voids 8 to occur inside the film. Since the back surface layer 2'c containing 9 has a small heat insulating effect, the heat of the steam transmitted to the metal layer 3 is effectively transmitted to the stretched resin film of the surface layer 2'b, so that the surface layer 2'b. The stretched resin film can be efficiently shrunk, and the lid 1 can be quickly returned to the state before being opened. Further, when different inorganic fine powders are blended separately for the front surface layer 2'b and the back surface layer 2'c, the front surface layer 2 '
b, the back surface layer 2'c can be filled in a larger amount as compared with the case where the same type of inorganic fine powder is blended, so that the calories burned in the lid 1 can be reduced, and the burned waste after use can be burned. Can be made easier. Further, the base material layer may be one obtained by adhesively laminating high-quality paper made of printed pulp as a material and art paper on the surface layer of these laminates (printing is not necessary).

Inorganic fine powder The above-mentioned inorganic fine powder generally has a particle size of 0.03 to 1
5 μm, preferably 0.1 to 5 μm, and an aspect ratio of 8 to 35, preferably 10 to 20 talc, scaly inorganic fine powder such as mica, and a particle size of 0.03 to 15
Examples include calcined clay having a size of μm, calcium carbonate, diatomaceous earth, titanium oxide, balm culite and the like.

Thermoplastic Resin As the above-mentioned thermoplastic resin, polypropylene, polyethylene, ethylene / propylene copolymer, ethylene / buden-1 copolymer, ethylene / 4-methylpentene-1 copolymer, propylene / ethylene / buden are used. -1 copolymer,
Examples thereof include polystyrene, polyethylene terephthalate, nylon-6, nylon-6,6, nylon-6,10 and nylon-6,12.

The thermoplastic resin film containing an extended elongation above inorganic fine powder is stretched at a temperature lower than the melting point of the resin. The stretching ratio at this time is 1.3 to 15 times, preferably 3.5 to 10 times in each of the one direction and the two directions. The number of stretching axes is uniaxial or biaxial.

Physical Properties <Void> In the lid of the container of the present invention, the stretched resin film used for the base material layer 2 has a large number of fine voids 8 with an inorganic fine powder as a core. Such a stretched resin film has a porosity of 4 to 60%, preferably 8 to 50% calculated by the following formula. Porosity = [(ρ ₀ −ρ) / ρ ₀ ] × 100 ρ ₀ : Density of film before stretching ρ: Density of film after stretching

<Thermal Expansion Coefficient> In the container lid of the present invention, the thermal expansion coefficient (L _e ) of the thermoplastic resin film 2b of the base material layer.
is important. This coefficient of thermal expansion was measured using a thermomechanical analyzer "TM-7000" (trade name) manufactured by Vacuum Riko Co., Ltd.
After using a test piece having a width of 5 mm and a length of 25 mm, the test piece was fixed to a chuck, the span distance (L ₀ ) was set to 15 mm, and the load was set to 1 g.
The temperature is raised from 80 ℃ to 80 ℃,
The span length (L) of the test piece at the temperature of was measured, and the value (TMA method) obtained by the following equation is shown. Thermal expansion coefficient = [(L−L ₀ ) / L ₀ ] × 100 The value of this thermal expansion coefficient is such that the smaller thermal expansion coefficient is 0.2 to
0.8%, preferably 0.2 to 0.6%, and the larger coefficient of thermal expansion is 0.4 to 1.2%, preferably 0.5 to
1.0%, and the difference between the larger coefficient of thermal expansion and the smaller coefficient of thermal expansion is 0.08 to 0.4%. When the value of the coefficient of thermal expansion of the base material in the direction of peeling the lid is less than 0.2%, the lid does not automatically close the container when the lid is put on after hot water is supplied and then the hand is released. Further, if the content exceeds 0.8%, the lid may automatically close the container during hot water supply. If the difference in coefficient of thermal expansion is less than 0.08%, the lid may automatically close the container after hot water is supplied, and if it exceeds 0.4%, the lid may be touched after hot water is supplied. When the lid is touched and the hand is released, the lid again separates from the edge of the container and warps back, and the lid cannot automatically close the container. T of this base material layer
The value of the coefficient of thermal expansion obtained by the MA method is the amount of minute voids in the base material layer, the draw ratio, the wall thickness, the draw temperature, the material resin,
It depends on the type of inorganic fine powder.

<Tensile Elastic Modulus> The tensile elastic modulus of the base material layer (JI
S-K7113) is 10,000-45,000 kg
/ Cm ² , preferably 15,000-30,000 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.

The thickness of the thick cover substrate layer for use in the container of the present invention generally 15～180Myuemu, preferably 40 to 100 [mu] m. The base material layer is made of a stretched thermoplastic resin film containing 8 to 65% by weight of inorganic fine powder (excluding scale-like inorganic fine powder), and has many fine voids inside, and the surface is printed. Which comprises at least two layers, a front surface layer 2'b and a back surface layer 2'c made of a thermoplastic resin film containing 5 to 70% by weight of scale-like inorganic fine powder (see FIG. 9). ), The thickness of the surface layer 2′b is 2 to 80 μm, preferably 3 to 40 μm
The thickness of the core layer 2'a is 0 to 150 µm, preferably 20 to 100 µm, and the thickness of the back surface layer 2'c is 3
˜80 μm, preferably 10-40 μm.

(B) Adhesive Layer The adhesive layer laminated in the lid of the container of the present invention for laminating the base material layer and a metal layer such as an aluminum foil described later is a urethane prepolymer, a liquid polyester, Isocyanate-based, polyester isocyanate-based, polyether isocyanate-based, polyethyleneimine-based, organic titanate-based anchor coating agents, low-density polyethylene, ethylene / vinyl acetate copolymers, ethylene / acrylic acid copolymers and other hot melt adhesives Can be mentioned. 1-20g / m for coating type adhesive
² , preferably used in an amount of 2-6 g / m ² . Hot melt adhesive is melt extrusion laminated, 8-30μ
Used with a thickness of m. Such an adhesive layer is typically 1
It is used in a thickness of -30 μm, preferably 2-15 μm.

(C) Metal Layer As the metal layer used in the lid of the container of the present invention,
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. Especially the wall thickness is 6 ~ 15μ
It is preferable to use an aluminum foil of m for the reasons of handling and economical reasons. Further, from the economical viewpoint, the metal foil is usually used with a thickness smaller than that of the base material layer.

(D) Heat-sealable resin layer As the heat-sealable resin used for heat-sealing the container and the lid in the present invention, a resin having a melting point lower than that of the resin constituting the base material layer is used. .. Specific examples of such heat-sealable resin include low-density polyethylene,
Linear low density polyethylene, ethylene / vinyl acetate copolymer (preferably ethylene / vinyl acetate copolymer having a vinyl acetate content of 12% by weight or less), ethylene / acrylic acid copolymer (preferably ethylene content of 65 to 94) Wt% 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 Examples thereof include copolymers, ethylene / propylene / butene-1 copolymers, vinyl chloride / vinyl acetate copolymers, and the like. 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. The thickness of the heat-sealable resin layer is 2 to
The thickness is 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 storage period of the food in the container.

(2) Pulling part In the container lid 1 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 in the present invention. Since the pulling portion 11 of the lid 1 coincides with the peeling direction α of the lid 1, in order to prevent the lid from automatically closing during hot water supply in the container, the coefficient of thermal expansion of the base material layer 2 is set. It is desirable to provide it in conformity with the direction β in which the value is small. However, in order to reduce the material loss when trimming the lid 1 from the laminated sheet 6 made of the base material layer 2, as shown in FIG. If the angle is θ, the lid during hot water supply can be prevented from automatically closing, and after the hot water supply is finished, touch the lid lightly with the hand to touch the edge of the container, and then remove the hand from the lid. The self-closing property of the lid 1 can be maintained to such an extent that the self-closing property of is slightly delayed.

(3) Peeling direction display portion In the lid 1 of the container of the present invention, the peeling direction α of the lid 1 is displayed on the surface of the lid by printing as shown in FIG. 8 instead of the pulling portion 11. 11 'may be used. The peeling direction α indicated by the peeling direction display portion 11 ′ of the lid 1 is the same as that of the pulling portion 11.

(4) 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.

(5) Container As a cup container used for instant food, polystyrene paper (PSP), which has a good heat retaining property, is usually used.
High-impact polystyrene (HIPS) sheet, laminated sheet of nylon and polyethylene into a cup shape by plug-assist vacuum forming or pressure forming, expanded polystyrene cup obtained by in-mold bead foam forming,
A cup-shaped container obtained by injection molding a thermoplastic resin such as polypropylene, high-density polyethylene, or polycarbonate is used.

(6) Food to be Stored The instant food cooking container of the present invention can be used for instant cup noodles, cup shiruko, cup soup, cup miso soup, cup miso cook, cup miso soup and the like. Therefore, the food contained in the cup-shaped container is the same as the conventional instant food. For example, for cup noodles, dry noodles such as ramen, udon, soba,
It is an ingredient such as soup, dried vegetables, dried meat, and dried oil. For cup soup, dried soup powder and dried vegetables, mushrooms such as corn, leeks, potatoes,
Shiitake and other ingredients are the miso and dried vegetables in the cup miso soup, and the cooked rice is the dried seafood ingredients in the cup porridge. When simmering in a cup
Mochi, powdered soup, dried vegetables or seafood.

[II] Production of Instant Food Cooking Container (1) Heat Sealing A laminated sheet composed of a base material layer 2 / adhesive layer 3 / metal layer 4 / heat sealable resin layer 5 which forms the lid 1 of the container of the present invention. 6
Is placed on a container 9 containing food such as dried noodles 12 and ingredients 13 therein, and is usually 100 to 160 ° C., preferably 1
A container with a lid is manufactured by heat-sealing at a temperature of 20 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. Further, when the containers 9 heat-sealed to the laminated sheet 6 on which the printed peeling direction display portion 11 'is formed are cut into individual containers 9, the peeling can be performed in the printed peeling direction 11'. A circular shape that is larger than the edge of the container (for example, diameter 150 mm)
The lid 1 of is trimmed. (3) Shrink packaging Next, the sealed container thus obtained is shrink-wrapped to form a product (improved cup noodle).

[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 2 is subjected to the thermal expansion of the metal layer 4 of the material forming the lid 1.
The thermal expansion of the above is superior, and the lid 1 automatically tries to return to the original position automatically due to the bimetal effect, but the thermal expansion coefficient in the direction (MD) in which the base material thermal expansion coefficient is large is small in the middle. (TD) coefficient of thermal expansion is overcome, and as shown in FIG. 10, the approximate center of the container (the edge surface where the container lid is sealed,
The angle between the handle part of the lid and the surface including the center point of the lid is 20 to 90.
The lid does not automatically close the container during hot water supply, and the phenomenon that the hot water rebounds on the lid is not seen.

[IV] When the hot water supply into the container is completed, as shown in FIG. 11, lightly put a hand on the opening side of the lid to close the lid, or close the container with the lid. , Shorten the distance between steam and lid. Then, after closing the lid by hand once, even if the lid rebounds and returns to a slightly bent state when the hand is released from the lid, the lid automatically returns to the state of the container in 1 to 5 seconds by steam. The opening can be closed (closed).

[0031]

【Example】

Example 1 Production of base material layer (1) 81% by weight of polypropylene (melting point about 164-167 ° C.) having a melt flow rate (MFR) of 0.8 g / 10 min
High density polyethylene 3% by weight and average particle size 1.5μ
Composition (A) in which 16% by weight of calcium carbonate
Was kneaded by an extruder set at 270 ° C., extruded into a sheet, 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 MFR of 4g / 10min (melting point approx. 1
(64 to 167 ° 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 form from a die. This 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., about 1
It is heated to a temperature of 75 ° C, stretched 7.5 times in the transverse direction using a tenter, annealed at a temperature of 165 ° C, cooled to a temperature of 60 ° C, and the ears are slit into three pieces. Layer structure (uniaxial stretching / biaxial stretching / uniaxial stretching), wall thickness 8
0 μm (B / A / B = 20 μm / 40 μm / 20 μm)
A base material layer of The void ratio of each layer is (B / A /
B = 4.6% / 13.9% / 4.6%).

Manufacture of lid : Multicolor offset printing was applied to the surface of the base material layer, and an anchor coating agent of urethane prepolymer was applied to the back surface side so as to be 3 g / m ^2, and the thickness was 6 μm.
m aluminum foil was laminated. An ethylene / vinyl acetate copolymer (vinyl acetate content 5.4% by weight) was extrusion laminated (wall thickness: 22 μm) at 200 ° C. on the aluminum foil side of this laminate, and then cooled. This was trimmed so that a tensile portion was formed in a direction perpendicular to the sheet feeding direction (TD direction with a small coefficient of thermal expansion) to obtain a substantially circular lid (diameter 150 mm, tensile portion 10 m).
m).

Heat sealing : 250 g of dried noodles and 25 g of ingredients were placed in a polystyrene foam container having a capacity of 1,000 cc and a diameter of about 150 mm, and the lid was heat-sealed (heat-sealed) by applying pressure at 140 ° C. for 0.5 seconds. ..

Evaluation After standing 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 boiling water (temperature of about 91 ° C.) is opened from this opening. The self-closing property of the lid was measured by pouring 600 cc into the container for 8 seconds. That is, Table 1 shows the opening degree of the lid (angle of δ in FIG. 10) immediately after hot water supply. Next, lightly touch the lid, put the lid on the edge of the container so as to close the open part of the container, and then, after releasing the hand from the lid, open the lid after 2 seconds and 15 seconds. The lid was automatically closed when the opening was 180 degrees, and the container was closed by the lid. When the opening exceeded 180 degrees, the lid curled inward as shown in FIG. Shows what has gone away). The results obtained are shown in Table 1. In addition, in Table 1, the opening degree of the lid when the lid is left as it is for 30 seconds after the hot water supply is also shown for reference.

Example 2 A lid of a container was obtained in the same manner as in Example 1 except that the grip portion for peeling off the lid when trimming was carried out so as to be located at a position 15 degrees away from the TD direction of the base material. Was manufactured and evaluated. The results are shown in Table 1.

Example 3 A lid was produced and evaluated in the same manner as in Example 1 except that the substrate layer was produced as follows. The results obtained are shown in Table 1. Production of base material layer (1) MFR 0.8 g / 10 min polypropylene 81% by weight, high density polyethylene 3% by weight and average particle size 1.5
The composition (A) in which 16% by weight of calcium carbonate (μm) was mixed was kneaded by an extruder set at 270 ° C., extruded into a sheet, and cooled by a cooling device to obtain an unstretched sheet. 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) in which 54% by weight of polypropylene having an MFR of 4.0 g / 10 min and 46% by weight of calcium carbonate having an average particle size of 1.5 μm were mixed and kneaded in another extruder, This was extruded in a sheet form from a die and laminated on both sides of the (1) 5-fold stretched film to obtain a laminated film having a three-layer structure. Then, this laminated film having a three-layer structure
After cooling to 0 ° C, it is heated again to a temperature of about 160 ° C and stretched 7.5 times in the transverse direction using a tenter,
Annealing treatment at a temperature of 5 ° C., cooling to a temperature of 60 ° C., slits in the ears, three-layer structure (uniaxial stretching / biaxial stretching / uniaxial stretching), thickness 60 μm (B / A / B = 1
A substrate layer of 5 μm / 30 μm / 15 μm) was obtained. Also,
The void ratio of each layer is (B / A / B = 30% / 33.7%
/ 30%).

Example 4 A lid for a container was prepared in the same manner as in Example 3, except that the grip portion for peeling the lid when trimming was carried out at a position displaced by 15 degrees from the TD direction of the base material. Was manufactured and evaluated. The results are shown in Table 1.

Example 5 Production of Substrate Layer (1) MFR 0.8 g / 10 min polypropylene (melting point 1
64 ° C.) 85% by weight, 5% by weight of high-density polyethylene and 10% by weight of calcium carbonate having an average particle size of 1.5 μm were mixed and kneaded with an extruder set at 270 ° C. It was extruded into a sheet and cooled by a cooling device to obtain an unstretched sheet. And this sheet 150
After heating again to a temperature of ° C, it was stretched 5 times in the machine direction. (2) Composition (B) prepared by mixing 60% by weight of polypropylene having an MFR of 4.0 g / 10 min with 40% by weight of calcium carbonate having an average particle size of 1.5 μm and polypropylene 60 having an MFR of 4.0 g / 10 min. A mixture (C) of 40% by weight and 40% by weight of talc having an aspect ratio of 12 is kneaded in separate extruders, and then extruded into a sheet form from a die, which is a 5 times stretched film of (1). Was laminated on both surfaces to obtain a laminated film having a three-layer structure (B layer / A layer / C layer). Then, after cooling the laminated film having the three-layer structure to 60 ° C., it is heated again to a temperature of about 161 ° 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 70 μm (B / A / C = 17 μm / 36 μm).
m / 17 μm) was obtained. The void ratio of each layer was (B / A / C = 30% / 25% / 5%).
The printing surface was applied to the surface of layer B.

Manufacture of Lid The surface of the above-mentioned base material layer was printed, and further, an anchor coating agent of urethane prepolymer was applied to the back surface side so as to be 3 g / m ^2, and an aluminum foil having a thickness of 6 μm was 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
D) was trimmed so that the printing in the pulling direction coincided with the direction perpendicular to (TD), and a circular lid was obtained (diameter 15).
0 mm, tensile part 10 mm).

Heat-sealing capacity 1,000 cc, 250 g of dried noodles, 25 g of ingredients in a container made of expanded polystyrene (PSP) having a diameter of about 150 mm.
Then, the lid was heat-sealed by applying pressure at 140 ° C. for 0.5 second.

Evaluation After leaving for one day, the lid is pulled with a finger in the peeling direction printed on the lid of the expanded polystyrene container to open 2/3 of the lid, and boiling water is boiled from this opening. (Temperature about 91
600 ° C.) was poured into the container for 8 seconds, and then evaluated in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 1 A lid was produced and evaluated in the same manner as in Example 1 except that the substrate layer was produced as follows. The results obtained are shown in Table 2. Production of Base Layer A transparent unstretched polypropylene film “Taiko FHK2” (trade name, wall thickness 60 μm) manufactured by Nimura Sansho Co., Ltd. was used. (Void ratio of base material 0%)

Comparative Example 2 The procedure of Example 2 was repeated except that the base material layer was manufactured as follows. The results obtained are shown in Table 2. Production of Base Layer A transparent unstretched polypropylene film “Taiko FHK2” (trade name, wall thickness 60 μm) manufactured by Nimura Sansho Co., Ltd. was used. (Void ratio of base material 0%)

Comparative Example 3 The procedure of Example 2 was repeated, except that the base material layer was manufactured as follows. The results obtained are shown in Table 2. Production of base material layer Paper for base material of commercially available cup ramen lid ("Cormorant" (trade name) of Fuji Kako Co., Ltd. (wall thickness 90 μm,
A basis weight of 82.4 g / m ² )) was used. Reference Example 1 (Example 1 of Japanese Patent Application No. 3-88733) In Example 1, the side of the lid where the tensile portion is provided is provided in the sheet feeding direction (MD direction) of the base layer having a large coefficient of thermal expansion. Other than the above, the lid of the container was manufactured and evaluated in the same manner. The lid of this product closed itself 18 seconds after hot water was supplied. Also, immediately after hot water supply,
Table 2 shows the evaluation results when the lid was touched.

[Table 1] Example 1 2 3 4 5 Physical properties of base material layer (μm) 80 80 60 60 70 Porosity (%) 10.2 10.2 33.0 33.0 21.4 Thermal expansion coefficient MD 0.65 0.65 0.48 0.48 0.55 (%) TD 0.41 0.41 0.28 0.28 0.30 Tensile elastic modulus MD 26,710 26,710 17,100 17,100 19,050 (kg / cm ² ) TD 39,080 39,080 29,800 29,800 35,800 Lid peeling direction TD TD + 15 degrees TD TD + 15 degrees TD Lid rating Opening of lid before hot water supply 40 degrees 50 degrees 30 degrees 30 degrees 45 degrees Openness of lid immediately after hot water supply 50 degrees 50 degrees 50 degrees 55 degrees 60 degrees With or without lid closed No No No No No hands Open the hands, and after 2 seconds, the lid will not warp. Open No Open No Open No Open Open 180 degrees 180 degrees 180 degrees 180 degrees 180 degrees Closed closed Closed closed Closed closed Closed closed Closed hot water After that, the opening of the lid after 30 seconds 55 degrees 50 degrees 95 degrees 90 degrees 70 degrees

[Table 2] Comparative Example Reference Example 1 2 3 1 Physical properties of base material layer Thickness (μm) 60 60 90 80 Porosity (%) 0 0 -10. 2 Thermal expansion coefficient MD 2.33 2.33-0.65 (%) TD 1.69 1.69-0.41 Tensile elasticity Rate MD 8,200 8,200 -26,710 (kg / cm2) TD 8,720 8,720 -39,080 Lid peeling direction TD TD +15 degrees TD MD Lid evaluation Opening of lid before hot water supply 35 degrees 35 degrees 70 degrees 60 degrees Openness of lid immediately after hot water supply 170 degrees 160 degrees 65 degrees 110 degrees Whether or not the lid is closed Yes Yes No Yes Open and after 2 seconds, the lid warps or not Yes Yes Yes No ^{(Inner curl) (Inner curl) (Outer curl)} Lid opening 180 degrees <180 degrees <85 degrees 180 degrees Closed Partial opening Partial opening Opened and closed Closed opening after 30 seconds of hot water supply 180 degrees <180 degrees <70 degrees 180 degrees

[0047]

According to the lid of the instant cooked food container of the present invention, even if a part of the lid is peeled off from the container and hot water is supplied into the container, the lid of the container does not automatically close and block the container. , Hot water does not splash back on the lid while hot water is being supplied, so you will not get burned. In addition, after hot water is supplied, simply cover the opening of the container with your hand lightly touching the lid, and even if you release your hand from the lid, it will be warmed by the steam supplied in the container, and the bimetal effect will work automatically. In addition, since the lid can close the container in a short time, it is not necessary to close the lid and place a weight after refueling unlike the conventional cup noodles.

[Brief description of drawings]

FIG. 1 is an enlarged 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 a state where hot water is poured into the container, a hand is attached to the lid, the hand is released from the lid, and then the lid is closed by a bimetal effect. Is.

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 plan view of a laminated sheet when trimming the lid of the container of the present invention from the laminated sheet.

FIG. 5 is an enlarged cross-sectional view of a conventional lid.

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 a perspective view of an instant food cooking container showing another embodiment of the present invention.

FIG. 9 is an enlarged cross-sectional view of a lid of a container showing another embodiment of the present invention.

FIG. 10 is a perspective view of a cup noodle container for explaining the openings of the container and the lid.

FIG. 11 is a perspective view of a cup noodle container showing a state in which a hand is put on the lid of the cup noodle container after hot water supply.

[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 3 Adhesive layer 4 Metal layer 5 Heat sealable resin layer 6 Laminated sheet 7 Inorganic fine powder 8 Void 9 Container 10 Gap 11 pulling part 11 'printed pulling direction 12 dry noodles 13 tool 14 printing α peeling direction β direction of low coefficient of thermal expansion γ direction of high value of thermal expansion θ direction β showing low coefficient of thermal shrinkage Angle within 30 degrees δ Opening between lid and container

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasushi Hosono, 23, Towada, Kamisu-cho, Kashima-gun, Kashima-gun, Ibaraki Okaka Synthetic Paper Co., Ltd. Kashima factory (72) Inventor Takashi Funato Kashima-gun, Ibaraki 23, Towada, Kamisu-cho Oji Yuka Synthetic Paper Co., Ltd., Kashima Plant (72) Inventor Yukio Kohama 826, Hagizono, Fukaden, Chigasaki City, Kanagawa Tokai Aluminum Foil Co., Ltd., Chigasaki Plant (72) Inventor Kazunori Yamada 826 Hagiden, Chigasaki, Kanagawa Prefecture, Tokai Aluminum Foil Co., Ltd., Chigasaki Plant (72) Inventor, Toshiaki Watanabe 826, Hagiden, Chigasaki, Kanagawa, Chigasaki Plant, Tokai Aluminum Foil Co., Ltd. 72) Inventor Chiaki Kanai 826 Fukuda, Hagien, Chigasaki, Kanagawa Tokai Aluminum Foil Co., Ltd. Chigasaki Plant

Claims (2)

[Claims] 1. A lid which is composed of a laminated sheet of a base material layer / adhesive layer / metal layer / heat-sealable resin layer and is used for sealing a container, the lid having the heat-sealable resin layer interposed therebetween. In the lid of the container having a pulling part at the end for peeling the lid from the container when it is heat-sealed, or the lid of the container in which the peeling direction is printed, the base material layer is A single layer of a stretched resin film having a large number of fine voids or a layer made of a laminated sheet containing a stretched resin film having a large number of fine voids inside, and the position or printing formed on the lid portion of the tension portion. The peeling direction is such that the thermal expansion coefficient is small when the temperature of the base material layer of the lid is raised from 30 ° C. to 80 ° C. over 5 minutes at a heating rate of 10 ° C./min. Is provided to match The lid of the container, characterized and. 2. The lid of the container according to claim 1, wherein the base material layer has the following properties (1) to (3). (1) The substrate layer is heated at a temperature rising rate of 10 ° C./min for 5 minutes to 30 ° C.
When the temperature is increased from 80 ° C. to 80 ° C., the coefficient of thermal expansion in the direction in which the tensile portion of the base material layer is provided is 0.2.
Within 0.8%. (2) In the coefficient of thermal expansion, the difference between the large value of the coefficient of thermal expansion and the small value of the coefficient of thermal expansion of the base material layer is 0.08 to 0.4%. (3) The fine voids in the stretched resin film of the base material layer have a porosity of 4 to 60% calculated by the following equation. Porosity = [(ρ ₀ −ρ) / ρ ₀ ] × 100 ρ ₀ : Density of film before stretching ρ: Density of film after stretching