JP2012148805A - Cover material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cover material capable of exposing a stable liquid draining opening in regard to the cover material required to drain water or hot water when eating.SOLUTION: The cover material includes: a surface layer formed of a paper base material; an intermediate layer formed of a plastic film; a sealant layer having easy peeling performance; and a bonding layer bonding the surface layer and the intermediate layer to each other. The cover material is peeled at an interface between the bonding layer and the intermediate layer so as to be divided into an upper material which is formed of the surface layer and the bonding layer, and a lower material which is formed of the intermediate layer and the sealant layer. The stiffness strength of the upper material is set at 5.0-20.0 N/15 mm, and the stiffness strength of the lower material is set at 0.30-3.0 N/15 mm.

Description

  The present invention relates to a lid member that requires drainage or hot water when eating, such as instant ramen, instant fried noodles, or jelly or toroten, which are prepared by pouring water or hot water.

  Conventionally, instant ramen and instant fried noodles that are poured by pouring water or hot water require drainage when eating, and have a mechanism that peels off a part of the lid to expose the liquid discharge port.

  Usually, the food container 80 to which the lid 1 as shown in FIG. 1 is attached is used as the instant yakisoba food container. The food container 80 is configured by attaching the lid 1 so as to cover the opened upper part of the container body 70 filled with food. The lid member 1 is formed with a half-cut separating line 2, and the removal region of the lid member 1 is peeled and removed along the separating line 2, as shown in FIG. A liquid discharge port 3 communicating with the inside is formed at a predetermined portion.

  In such a food container, a method for peeling a part of the lid to expose the liquid discharge port has been proposed for various improvements in order to perform stable peeling, for example, along the shape of the liquid discharge port A method of partially coating the peeling varnish is known, but the manufacturing problem that it is difficult to register the half-cut applied from the sealant side to form a liquid discharge port has not been solved (Patent Document 1). reference).

  On the other hand, regarding the method of exposing the liquid discharge port using the interface peeling mechanism between the plastic film and the plastic resin, the inside of the half cut for forming the liquid discharge port by peeling the surface material in the width direction of the liquid discharge port Although it has been reported that the part can be separated from the substrate side without being greatly bent, there are actually problems such as the liquid discharge port not being formed due to the drop of the liquid discharge port forming part due to variation in peel strength. It often occurs (see Patent Document 2).

JP2008-290725A Japanese Patent No. 4369713

  The present invention relates to a lid that requires drainage or hot water when eating, such as instant ramen, instant yakisoba, or jelly or toroten, which are poured by pouring water or hot water, and a plastic film and plastic resin A lid member capable of exposing a stable liquid discharge port by using an interfacial peeling mechanism is provided.

The invention according to claim 1 of the present invention includes a surface layer made of a paper base material, an intermediate layer made of a plastic film, and a sealant layer having an easy peel property, and joining the surface layer and the intermediate layer. In a lid member comprising a layer, and a liquid discharge port forming part surrounded by a half cut formed so as to reach from the sealant layer to at least the bonding layer,
Interface peeling between the bonding layer and the intermediate layer,
It is separated into an upper material composed of the surface layer and the bonding layer, and a lower material composed of the intermediate layer and the sealant layer,
The waist strength of the upper material is 5.0 N / 15 mm or more and 20.0 N / 15 mm or less,
The lower material has a waist strength of 0.30 N / 15 mm or more and 3.0 N / 15 mm or less.

  The invention according to claim 2 of the present invention is characterized in that the peel strength between the bonding layer and the intermediate layer is 0.10 N / 15 mm or more and 1.0 N / 15 mm or less. It is.

  The invention according to claim 3 of the present invention is characterized in that the surface on the bonding layer side of the intermediate layer has a wettability of 40 dynes or less in the measuring method of JIS-K6768. It is a lid.

  The invention according to claim 4 of the present invention is the lid according to any one of claims 1 to 3, wherein the joining layer is a polyolefin resin layer formed by a melt extrusion method. It is.

  In the invention according to claim 5 of the present invention, the liquid discharge port is exposed to the lower material after the upper material and the lower material are separated from each other. It is a cover material of description.

  The invention according to claim 6 of the present invention is the lid according to any one of claims 1 to 5, wherein an aluminum layer is laminated between the intermediate layer and the sealant layer. .

  According to the first aspect of the present invention, the surface layer / intermediate layer / sealant layer is a laminated lid member, and the surface layer and the intermediate layer are joined by the joining layer. A liquid discharge port forming portion surrounded by a half cut is formed in advance, and the interface layer is peeled off between the bonding layer and the intermediate layer, whereby the upper material composed of the surface layer and the bonding layer, and the lower layer composed of the intermediate layer and the sealant layer. It separates into the material, the liquid discharge port forming part follows the upper material, and the liquid discharge port is exposed to the lower material. At this time, when the waist strength of the upper material is 5.0 N / 15 mm to 20.0 N / 15 mm and the waist strength of the lower material is 0.30 N / 15 mm to 3.0 N / 15 mm, The peeling angle R of the upper material is increased, and the liquid discharge port forming portion surrounded by the half cut can easily follow the upper material. As a result, it is possible to prevent the liquid discharge port forming part from dropping off at the time of peeling, and a stable peeling and liquid discharge port can be obtained.

  The waist strength is one characteristic value that represents the same characteristics as the rigidity and elasticity of a simple substance such as paper, film, or metal foil, or a composite laminate thereof. Waist strength is a loop stiffness measurement. The measurement method is to make a loop with a strip-shaped sample with a width of 15 mm and a length of 12 cm, crush the loop at a crushing distance of 20 mm and a compression speed of 3.5 mm / second, measure the repulsive force of the loop, and measure the loop stiffness. And An example of the measuring device is a loop stiffness tester {manufactured by Toyo Seiki Seisakusho Co., Ltd.}.

  According to claim 2 of the present invention, the peel strength between the bonding layer and the intermediate layer is 0.10 N / 15 mm or more and 1.0 N / 15 mm or less. It is preferably 0.15 N / 15 mm or more and 0.5 N / 15 mm or less. If it is 0.10 N / 15 mm or more and 1.0 N / 15 mm or less, most users can easily peel and remove the upper material of the removal region portion to expose the liquid discharge port. When the peel strength is less than 0.10 N / 15 mm, when the upper material of the removal region portion is peeled off, a part of the liquid discharge port forming portion may not follow the upper material and the liquid discharge port may not be formed. If the peel strength is 1.0 N / 15 mm or more, the strength is strong, and variation may occur during peeling, and the liquid discharge port may not be formed stably.

  The peel strength was measured according to JIS-Z1707 using a tensile / compression tester Tensilon RTF-1250 {manufactured by A & D Co., Ltd.}.

  According to claim 3 of the present invention, the wettability of the surface of the intermediate layer on the bonding layer side is 40 dynes or less in the measuring method of JIS-K6768. Preferably 20 dynes to 40 dynes or less. When the wettability is less than 20 dynes, the bonding between the bonding layer and the intermediate layer becomes too weak, and when the upper material of the removal region is peeled off, a part of the liquid discharge port forming portion does not follow the upper material and the liquid discharge There may be no exit. On the other hand, if it is 40 dynes or more, the peel strength becomes 1.0 N / 15 mm or more, and stable peeling cannot be performed at the time of peeling, and variation may occur and the liquid discharge port may not be formed stably.

  According to claim 4 of the present invention, the bonding layer is a polyolefin resin layer formed by a melt extrusion method. Extrusion film formation is performed by an extrusion method using a polyethylene resin. That is, it is used as a bonding layer for laminating a surface layer made of a paper substrate and an intermediate layer of a plastic film. If the wettability of the surface of the intermediate layer on the bonding layer side is 20 dynes or more and 40 dynes or less, the laminate strength between the bonding layer and the intermediate layer is moderately moderated, and strong bonding is suppressed. As a result, when the bonding layer and the intermediate layer are peeled, the peel strength can be kept low. Therefore, the amount of force required to peel off the upper material of the removal region is reduced. Therefore, the user can easily peel and remove the upper material of the removal region portion to obtain the liquid discharge port.

  Further, when extrusion lamination is performed, it is desirable to bond without using an anchor coating agent on the bonding surface of the intermediate layer. When an anchor coating agent is used, the bonding strength is increased and stable interfacial peeling becomes difficult.

  In addition, when corona treatment, ozone treatment, etc. are applied to the paper substrate, the bonding strength between the paper substrate and the bonding layer is improved, the waist strength of the upper material is improved, and the interface peeling between the bonding layer and the intermediate layer is stabilized. be able to.

  According to claim 5 of the present invention, after separating the upper material and the lower material, the liquid discharge port is exposed to the lower material. Since the lid material of the present invention has a liquid discharge port forming portion surrounded by a half cut formed so as to reach from the sealant layer to the bonding layer, the upper material and the lower material are separated into the upper material when separated. The liquid discharge port forming part follows and the liquid discharge port can be exposed to the lower material.

  According to claim 6 of the present invention, an aluminum layer is laminated between the intermediate layer and the sealant layer. By laminating the aluminum layer, the lower strength of the lower material can be improved, and the interface peeling between the bonding layer and the intermediate layer can be stabilized.

  The present invention is an excellent lid material with a stable peeling mechanism in which the liquid discharge port forming portion does not fall off in the mechanism in which the upper material and the lower material of the lid material are peeled at the interface to expose the liquid discharge port to the lower material. .

It is a perspective view which shows an example of the food container with which the cover material was attached. It is a perspective view which shows an example of the state which removed the liquid discharge port formation part of the cover material. It is a top view which shows an example of the cover material of this invention. It is sectional drawing in the BB 'line of FIG. FIG. 5 is a cross-sectional view illustrating an example of a state in which the upper material and the lower material of FIG. It is sectional drawing which shows an example of the structure which laminated | stacked the aluminum layer on the cover material of this invention. FIG. 7 is a cross-sectional view showing an example of a state in which the upper material and the lower material of FIG.

  Hereinafter, embodiments for carrying out the present invention will be described.

  FIG. 1 is a perspective view showing an example of a food container 80 to which the lid 1 is attached. The food container 80 can be used, for example, as a container such as instant fried noodles, which is prepared by pouring hot water. The lid member 1 is formed with a half-cut separating line 2, and the removal region portion A of the lid member 1 is peeled and removed along the separating line 2 to remove the container body as shown in FIG. The liquid discharge port 3 communicating with the inside of the 70 is formed in a predetermined part.

  FIG. 3 is a plan view showing an example of the lid member of the present invention. The lid member 1 is formed in a substantially rectangular shape in plan view. A tongue piece 4 extends from a portion (corner portion) where the liquid discharge port 3 is formed, and is a knob for peeling and removing the removal region portion A of the lid member. A slit 5 extending in the width direction of the tongue piece 4 and penetrating the lid member 1 in the thickness direction is formed near the base of the tongue piece 4. A tongue piece 6 extends at a corner portion opposite to the corner portion where the tongue piece 4 is formed, and the lid material 1 is peeled off from the container body 70 and opened when pouring hot water into the container body. It is a knob. Further, the width direction dimension of the tongue piece 6 is set to be equal to or less than the dimension in the longitudinal direction of the slit 5, and the tongue piece 6 is inserted into the slit 5 by allowing the tongue piece 6 to be inserted into the slit 5. It is made to be able to.

  4 is a cross-sectional view taken along line BB ′ of FIG. The lid 1 includes a surface layer 10 made of a paper base material, a bonding layer 20 made of a polyolefin resin, an intermediate layer 30 made of a plastic film, and a sealant layer 40 having an easy peel property. The liquid discharge port forming portion 9 surrounded by the half cut 8 is formed from a part of the bonding layer 20, the intermediate layer 30, and the sealant layer 40. Further, the half cut 8 does not necessarily reach the surface layer 10 and only needs to penetrate the intermediate layer 30.

  FIG. 5 is a cross-sectional view showing an example of a state in which the upper member 50 and the lower member 60 of the lid member 1 are separated from each other to form the liquid discharge port 3. When the upper material 50 of the removal region portion A of the lid member 1 is peeled off, the liquid discharge port forming portion 9 surrounded by the half cut 8 follows the upper material 50 and the liquid discharge port is exposed to the lower material 60. It is formed.

  FIG. 6 is a cross-sectional view showing an example in which an aluminum layer 32 is laminated between the intermediate layer 30 and the sealant layer 40 of the lid material. As for the thickness of an aluminum layer, 7-12 micrometers normally used for the packaging material for foodstuffs is preferable. Further, when pouring hot water is required as in the case of instant noodles, providing the aluminum layer improves the rigidity and waist strength of the lid, making it easier to maintain the opened state. As a result, the workability is improved and the lid can be easily used. Further, by providing the aluminum layer, the lid member can be provided with a light-shielding property, so that there is an advantage that the storage stability of the contents can be improved.

  FIG. 7 is a cross-sectional view showing an example of a state in which the upper material and the lower material of the lid shown in FIG. When the upper material 50 of the removal region portion A of the lid member 1 is peeled off, the liquid discharge port forming portion 9 surrounded by the half cut 8 follows the upper material 50 and the liquid discharge port is exposed to the lower material 60. It is formed. In this case, the liquid discharge port forming portion 9 is formed of a part of the bonding layer 20, the intermediate layer 30, the aluminum layer 32, and the sealant layer 40.

Examples of the paper substrate 11 of the surface layer 10 include art paper, coated paper, high-quality paper, bleached kraft paper, and the like, but are not particularly limited. There are no specific rules regarding the paper basis weight.
The thing of 0-250 g / m < ² > is preferable and 90-150 g / m < ² > is more preferable. Moreover, you may provide the printing which provides a pattern and light-shielding property on the surface and back surface of a paper base material.

  Examples of the plastic film 31 of the intermediate layer 30 include polyester (polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc.), polyamide (nylon-6, nylon-66, etc.), polyvinyl chloride, polyimide, etc. A heat-resistant plastic film such as a copolymer can be used. The thickness is not particularly specified, but is preferably 9 to 100 μm, more preferably 9 to 25 μm. Further, for example, additives such as an antistatic agent, an ultraviolet absorber, a plasticizer, a lubricant, and a colorant can be added, and can be appropriately added as necessary. In addition, what gave the light-shielding property to the surface of the sealant side of these plastic films, or what laminated the film of the light-shielding material may be used, and what has barrier property may be used.

  As the sealant layer 40 having an easy peel property, it is desirable to have an excellent low-temperature seal property, and it is desirable that the seal strength does not change regardless of the change in the seal temperature. The sealant layer 40 is sealed with the container flange portion after filling, but the punching process itself into the lid material may be either during filling or after filling, and is not limited.

  The characteristics of the easy peel are not particularly limited, and any of a cohesive peeling type, an interlayer peeling type, and an interface peeling type may be used.

  The cohesive failure type is a type in which the sealant layer itself cohesively breaks down. Using a resin mixed with a resin such as polypropylene, polyethylene, polystyrene, etc., it is formed into a film and laminated on the intermediate layer 30, or a coating solution of this resin is used. It can be used by coating.

  The delamination type is a method in which a three-layer film is prepared by a coextrusion method and peeled off from the middle. This coextruded film can be laminated on the intermediate layer 30 and used.

  The interfacial peeling type can be used by forming a film using a resin in which the mixing ratio of vinyl acetate of the ethylene-vinyl acetate copolymer resin is increased, and laminating it on the intermediate layer 30.

  About the thickness of the plastic film 31 and the sealant layer 40, since it is a part which becomes a lower material after peeling of the cover material, the waist strength of the laminated part of the plastic film 31 and the sealant layer 40 is 0.30 N / 15 mm or more and 3.0 N / It is necessary to design it to be 15 mm or less.

  Examples of the polyolefin-based resin 21 of the bonding layer 20 include polyethylene and polypropylene, but it is more preferable to use low-density polyethylene from the viewpoint of handling. The paper substrate 11 and the plastic film 31 are laminated at the same time as this resin is extruded and formed by a melt extrusion method. The extrusion temperature is suitably 280 ° C. to 340 ° C. If it is lower than 280 ° C., not only the film forming property is inferior, but also the surface oxidation of polyethylene itself is insufficient, and the laminate strength between the paper base 11 and the plastic film 31 Will cause a decline. In addition, since the decomposition of the resin proceeds at a temperature higher than 340 ° C., not only uniform processing cannot be performed, but also the laminate strength is reduced. That is, it causes a decrease in peel strength.

  It is preferable not to apply the anchor coating agent to the surface of the plastic film 31 on the polyolefin resin 21 side. By not applying the anchor coating agent, the peel strength between the plastic film 31 and the polyolefin resin 21 can be set to 0.10 N / 15 mm or more and 1.0 N / 15 mm or less.

  As thickness of polyolefin resin 21, 5-50 micrometers is preferred and 10-30 micrometers is more preferred. At this time, after the interfacial peeling between the upper material and the lower material, the lid material has a waist strength of 5.0 N / 15 mm or more and 20.0 N / 15 mm or less at the laminated portion of the paper base material 11 and the polyolefin resin 21 as the upper material. It is necessary to design to become.

  Examples of the bonding method between the intermediate layer 30 and the sealant layer 40 include a wet lamination method, a dry lamination method, a non-solvent dry lamination method, a hot melt lamination method, an extrusion lamination method, and sandwich lamination using the extrusion lamination method. A known method such as a method can be used.

  As the sealant layer 40, when the adherend of the container is a polyethylene resin (PE), the combination of the base resin / the thermoplastic resin for the blend is a polyethylene resin (PE) / ethylene-methacrylic acid copolymer (EMAA). ), Polyethylene resin (PE) / ethylene-vinyl acetate copolymer (EVA), polyethylene resin (PE) / ethylene-acrylic acid copolymer (EAA), polyethylene resin (PE) / ethylene-ethyl acrylate copolymer A combination of (EEA) is preferred.

  Next, when the adherend of the container is a polystyrene resin (PS), the combination of the base resin / the thermoplastic resin for blending is an ethylene-vinyl acetate copolymer (EVA) / polybutene resin (PB), A combination of polyethylene resin (PE) + elastomer + petroleum resin / polybutene resin (PB) is preferred.

  Next, when the adherend of the container is a polypropylene resin (PP), the combinations of the base resin / the thermoplastic resin for blending are polypropylene resin (PP) / polystyrene resin (PS), polypropylene resin (PP). / Polyethylene resin (PE) combination is preferred.

  Further, the thickness of the sealant layer 40 is preferably in the range of 15 to 100 μm, more preferably in the range of 20 to 70 μm, in consideration of the seal strength and workability.

  In addition, a half cut line is provided in order to form the liquid discharge port forming portion in the lid. Half-cut lines are formed to reach the bonding layer. By reaching the bonding layer, the liquid discharge port can be stably formed.

  Examples of the present invention will be described in detail below, but the present invention is not limited to the examples.

A paper base material (gravure art paper) having a basis weight of 105 g / m ² as the material of the surface layer 10, and a polyester film (PET) having a thickness of 12 μm as the material of the intermediate layer 30 {trade name FE2001: manufactured by Futamura Chemical Co., Ltd.} Prepared. Next, the low-density polyethylene resin (LDPE) used as the joining layer 20 was extruded at 320 degreeC by the extrusion lamination method, and the paper base material and PET film were bonded together. The thickness of LDPE was 20 μm. The surface on the bonding layer side of the PET film was a surface not subjected to corona treatment. Further, a material containing a polystyrene resin on the PET surface was extruded at 280 ° C. by an extrusion laminating method to form a sealant layer 40 having easy peel properties to obtain a laminate. The thickness of the sealant layer 40 was 20 μm. Subsequently, the laminated product was half-cut from the surface layer side to form a separation line 2 and half-cut from the sealant layer side to provide a liquid discharge port forming portion. Finally, the laminated product was punched into outer dimensions to obtain a substantially rectangular lid 1. Thereafter, the sample was sealed in a foamed polystyrene container under the conditions of 135 ° C., 20 N / cm ² and 0.5 seconds to obtain a sample for evaluation.

  As a material for the intermediate layer, a PET film {trade name E5100: manufactured by Toyobo Co., Ltd.} having a thickness of 12 μm and subjected to corona treatment on one side was used. The surface on the bonding layer side of the PET film was the surface on the side not subjected to corona treatment. Otherwise, an evaluation sample was obtained in the same manner as in Example 1.

  As a material for the intermediate layer, an OPP film {trade name FOR: manufactured by Futamura Chemical Co., Ltd.} having a thickness of 20 μm and subjected to corona treatment on one side was used. The surface on the bonding layer side of the PET film was the surface on the side not subjected to corona treatment. Otherwise, an evaluation sample was obtained in the same manner as in Example 1.

  A sample for evaluation was obtained in the same manner as in Example 1 except that 7 μm of aluminum foil was laminated between the PET film of the intermediate layer and the sealant layer.

  Below, the comparative example of this invention is demonstrated.

<Comparative Example 1>
A 12 μm thick PET film {trade name Emblet (registered trademark) PET: manufactured by Unitika Co., Ltd.} having a corona treatment on one side was used as a material for the intermediate layer. The surface on the bonding layer side of the PET film was the surface on the side not subjected to corona treatment. Otherwise, an evaluation sample was obtained in the same manner as in Example 1.

<Comparative example 2>
A 12 μm thick PET film {trade name Tetron (registered trademark) PC: made by Teijin and manufactured by DuPont Films Co., Ltd.} having a corona treatment on one side was used as an intermediate layer material. The surface on the bonding layer side of the PET film was the surface on the side not subjected to corona treatment. Otherwise, an evaluation sample was obtained in the same manner as in Example 1.

<Comparative Example 3>
An evaluation sample was obtained in the same manner as in Example 1 except that 15 μm of aluminum foil was laminated between the PET film as the intermediate layer and the sealant layer.

<Comparative example 4>
An evaluation sample was obtained in the same manner as in Example 1 except that the paper basis weight was 85 g / m ² .

<Comparative Example 5>
An evaluation sample was obtained in the same manner as in Example 1 except that the paper basis weight was 85 g / m ² and PET was 6 μm {trade name Diafoil PET: manufactured by Mitsubishi Chemical Corporation}.

  The main performance evaluation methods will be described.

  (A) Waist strength: The waist strength of the upper and lower materials of the lid was measured. It was measured with a loop stiffness tester {manufactured by Toyo Seiki Seisakusho Co., Ltd.}. The sample was cut to a width of 15 mm, a loop was made with a strip-shaped sample having a length of 12 cm, the loop was crushed at a crushing distance of 20 mm, and a compression speed of 3.5 mm / sec, and the repulsive force of the loop was measured. The average value of n = 5 is shown.

(B) Peel strength: The peel strength between the bonding layer and the intermediate layer when removing the surface layer in the removal region surrounded by the separation line was measured. The sample was cut to a width of 15 mm, and measured according to JIS-Z1707 using a tensile / compression tester Tensilon RTF-1250 {manufactured by A & D Co., Ltd.} at 300 mm / min. The average value of n = 5 is shown.

  (C) Wettability: The wettability of the surface to be bonded to the bonding layer of the intermediate layer film before manufacturing the lid material was measured. The measurement was performed according to JIS-6768 using a mixed solution for wet tension test {manufactured by Wako Pure Chemical Industries, Ltd.}.

  (D) Dropping presence / absence of liquid discharge port forming portion: Evaluation of whether or not the liquid discharge port forming portion is dropped when the half-cut portion is opened before and after pouring. The evaluation after pouring was confirmed by injecting hot water of about 90 ° C into the container and leaving it for 3 minutes.

  Table 1 shows the evaluation results of Examples and Comparative Examples.

剥離強度では、実施例１〜４では、０．１０Ｎ／１５ｍｍ以上１．０Ｎ／１５ｍｍ以下の範囲内におさまっており、平均的なユーザーが手で容易に剥離できる強度であった。また各実施例とも、５回の測定において良好に液体排出口が形成され、液体排出口形成部が脱落することは発生しなかった。比較例１、２では、いずれも剥離強度が１．０Ｎ／１５ｍｍを大きく上回り、３．８Ｎ／１５ｍｍおよび４．５Ｎ／１５ｍｍであり、平均的なユーザーが剥離するには、困難な強度であった。

In Examples 1 to 4, the peel strength was within a range of 0.10 N / 15 mm to 1.0 N / 15 mm, and the strength was such that an average user could easily peel off by hand. In each of the examples, the liquid discharge port was satisfactorily formed in five measurements, and the liquid discharge port forming portion did not drop off. In Comparative Examples 1 and 2, the peel strength is much higher than 1.0 N / 15 mm, and is 3.8 N / 15 mm and 4.5 N / 15 mm, which is difficult for an average user to peel. It was.

  Regarding the waist strength, in Examples 1 to 4, the upper material has a waist strength of 5.0 N / 15 mm to 20.0 N / 15 mm and the lower material has a waist strength of 0.30 N / 15 mm to 3.0 N / 15 mm. The peel strength was within the above-mentioned range, and the liquid discharge port was formed well. In Comparative Examples 4 and 5, the waist strength of the upper material was less than 5.0 N / 15 mm, and 4.80 N / 15 mm, and the liquid discharge port forming portion was observed to drop after pouring.

  The wet dyne of PET film was 40 dynes or less in each of Examples 1 to 4, but 42 and 44 dynes in Comparative Examples 1 and 2 and exceeded. The peel strength also showed a strong value as described above, and the liquid discharge port forming part was also dropped after pouring.

  The lid material of the present invention is provided with a numerical range of three characteristics of the waist strength of the upper material and the lower material, the peel strength between the upper material and the lower material, the wettability of the plastic film on the surface to be peeled, It was possible to provide a lid material having an excellent peeling mechanism capable of stably obtaining a liquid discharge port.

  The food container to which the lid of the present invention is attached can be used as a container such as instant fried noodles, for example, pouring hot water and cooking. It can also be used for food containers such as spaghetti, macaroni, dried noodles, and harsame.

DESCRIPTION OF SYMBOLS 1 Cover material 2 Cutting line 3 Liquid discharge port 4 Tongue piece 5 Slit 6 Tongue piece 7 Interface peeling part 8 Half cut 9 Liquid discharge port formation part 10 Surface layer 11 Paper base material 20 Joining layer 21 Polyolefin-type resin 30 Intermediate layer 31 Plastic Film 32 Aluminum layer 40 Sealant layer 50 Upper material 60 Lower material 70 Container body 80 Food container A Removal area

Claims (6)

A surface layer made of a paper base material, an intermediate layer made of a plastic film, a sealant layer having an easy peel property, a bonding layer for bonding the surface layer and the intermediate layer, and at least the bonding layer from the sealant layer In a lid member provided with a liquid discharge port forming part surrounded by a half cut formed so as to reach
Interface peeling between the bonding layer and the intermediate layer,
It is separated into an upper material composed of the surface layer and the bonding layer, and a lower material composed of the intermediate layer and the sealant layer,
The waist strength of the upper material is 5.0 N / 15 mm or more and 20.0 N / 15 mm or less,
The lower member has a waist strength of 0.30 N / 15 mm or more and 3.0 N / 15 mm or less.   The lid material according to claim 1, wherein a peeling strength between the bonding layer and the intermediate layer is 0.10 N / 15 mm or more and 1.0 N / 15 mm or less.   The lid according to claim 1 or 2, wherein the surface of the intermediate layer on the bonding layer side has a wettability of 40 dynes or less in the measuring method of JIS-K6768.   The lid according to any one of claims 1 to 3, wherein the bonding layer is a polyolefin resin layer formed by a melt extrusion method.   The lid material according to any one of claims 1 to 4, wherein a liquid discharge port is exposed to the lower material after separation into the upper material and the lower material.   The lid member according to any one of claims 1 to 5, wherein an aluminum layer is laminated between the intermediate layer and the sealant layer.

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