JP2000079956A - Lid material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To apply easiness in unsealing at a point where peeling starts and to eliminate a problem such as legginess in the case of an easy-to-unseal mechanism of a cohesive peeling type regarding a lid material having a multi-layered structure mainly comprising thermoplastic resin layers. SOLUTION: In the lid material (b) having a multi-layered structure mainly comprising thermoplastic resin layers, the thermoplastic resin layer forming a sealant layer 1b of the lid material (b) is constituted of a thermoplastic resin whose tensile strength at break according to JIS.K7113 is 5 to 20 MPa. In addition, at least one of the thermoplastic resin layers may be constituted of a thermoplastic resin whose tensile elongation at break according to JIS.K7113 is 600% or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lid material for cups and trays, and more particularly, to a lid material for cups and trays having a multilayer structure mainly composed of a thermoplastic resin layer. The present invention relates to a cover material that can not only be provided but also can solve problems such as stringing that occurs at the time of opening.

[0002]

2. Description of the Related Art In the field of food packaging, packaging forms in which contents such as instant noodles, jellies, and yogurts are filled in cups or trays have been increasing. These cups or trays are generally manufactured by injection molding or vacuum compression molding of thermoplastic resins such as polystyrene, expanded polystyrene, and polypropylene resin. In consideration of volumetric capacity, recyclability, etc., paper cups etc. in which polyolefin resin such as polyethylene resin is laminated on paper have been developed, and the content is not limited to instant noodles,
Drinks and the like are also being filled.

[0003] The required quality of the lid material in these cup containers is that the innermost sealant layer of the lid material and the container such as a cup as an adherent should have strong adhesion in order to protect the contents. On the other hand, at the time of opening, conflicting demands for easy opening are required.

[0004] In order to satisfy such demands, various functions have been imparted to the lid material. One of them is the design of an easy-opening mechanism, examples of which include a delamination mechanism and a cohesion separation mechanism. Of these, the cohesive peeling mechanism is designed by blending an incompatible or partially compatible thermoplastic resin, and the peeling principle is that the cohesive force of the incompatible or partially compatible thermoplastic resin blend layer is small. This is explained by utilizing the cohesive failure of such an incompatible or partially compatible blend layer instead of the interface between the innermost sealant and the adherent at the time of opening.

[0005] One of the problems of the cohesive peeling type easy opening mechanism is stringing at the time of opening. In order to solve this problem, it is necessary to design the structure and morphology such as reducing the thickness of the easy-opening layer (blend layer) or reducing the domain diameter of the matrix-domain structure of the blend layer. The control of the matrix-domain structure causes a problem of the interfacial adhesion between the two. When the interfacial adhesion is increased (when the domain diameter is reduced), stringing does not occur, but the opening strength is increased. When it is made weak (when the domain diameter is made large), the opening strength becomes weak, and it is possible to impart easy-opening properties. However, depending on the blend constitution, stringing may occur. As described above, one method is to reduce the thickness of the easy-opening layer (blend layer). However, if the thickness is reduced, it becomes difficult to control the film thickness, and the workability is reduced.

In designing an easily-openable lid material, it is required to control not only the above-described opening strength and stringing at the time of opening but also the strength immediately after opening (at the time of opening). Trigger). Figure 1
A, -B. FIG. 1A shows the sealant layer 1B.
Is a blend layer, and this sealant layer 1b is cohesively peeled off, FIG. 1B is composed of a sealant layer 1b and an intermediate layer 2b composed of a blend layer, and the cohesive peeling of the intermediate layer or the delamination of the sealant layer 1b and the intermediate layer 2b Is shown. The following is a problem that can be applied to both cohesive peeling and interlayer peeling. However, when the lid is opened, the opening start point c of the container a such as a cup and the sealant layer 1b of the lid b is opened.
It is possible to impart easy-openability immediately after opening by reducing the strength of the sheet as much as possible. In order to control the easy opening property immediately after opening, the design of the tab d is also performed. However, if the function can be given to the sealant layer 1b of the lid material, the tab d design may be included. Since it is possible to provide a better easy-open lid material, it is presently desirable to design such a lid material.

[0007]

SUMMARY OF THE INVENTION The object of the present invention has been made in view of the above-mentioned problems, and in a lid material having a multilayer structure mainly composed of a thermoplastic resin layer, the easy-opening property at the peeling start point has been improved. It is an object of the present invention to provide a lid material that can solve problems such as stringing that occurs at the time of opening, in addition to the case of providing an aggregating and peeling type easy opening mechanism.

[0008]

SUMMARY OF THE INVENTION The present invention has been conceived to overcome the above-mentioned problems, and the invention according to claim 1 is directed to a lid material having a multilayer structure mainly composed of a thermoplastic resin layer. JIS. Of a thermoplastic resin layer forming a sealant layer of the lid material. Tensile rupture strength in K7113 is 5
A lid member made of a thermoplastic resin of 20 MPa. The invention according to claim 2 is
2. The lid material according to claim 1, wherein at least one of the thermoplastic resin layers is made of JIS. A lid material characterized by being composed of a thermoplastic resin having a tensile elongation at break of 600% or less in K7113. According to a third aspect of the present invention, in the lid material according to the first or second aspect, at least one of the thermoplastic resin layers having a multilayer structure is formed of a blend layer of two or more thermoplastic resins. Lid material,
It is what it was. The invention according to claim 4 is based on claim 1,
4. The lid material according to 2 or 3, wherein the sealant layer comprises a polyethylene resin, a polypropylene resin, an ethylene-α-olefin copolymer, an acid-modified olefin resin, an ethylene-vinyl acetate copolymer, an ethylene-α, β-unsaturated carboxylic acid. Or its esterified or ionically crosslinked product,
A lid material characterized by being a copolymerized polyester alone or a blend layer containing these as a main component. According to a fifth aspect of the present invention, in the lid material of the first, second, third or fourth aspect, the peel strength between the lid material and a container bonded to the lid material is 1 to 15 N / 15 mm. Cover material. The invention according to claim 6 is the cover according to claim 1, 2, 3, 4, or 5,
The lid member is characterized in that the separation between the lid member and the container is the cohesive separation of the blend layer. According to a seventh aspect of the present invention, in the lid member according to the first, second, third, fourth, or fifth aspect, the lid and the container are separated from each other by delamination of the multilayered thermoplastic resin layer constituting the lid. And a lid material characterized in that: According to an eighth aspect of the present invention, in the lid material according to any one of the first to seventh aspects, the container as an adherend of the lid material is a cup made of polyethylene resin, polypropylene resin, polyethylene terephthalate resin, polystyrene resin, A lid material characterized by being a tray. According to a ninth aspect of the present invention, there is provided the lid material according to any one of the first to seventh aspects, wherein the container to which the lid material is adhered is a paper cup or paper in which a polyethylene resin, a polypropylene resin, and a polyethylene terephthalate resin are laminated. A lid material characterized by being a tray.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The lid material of the present invention has a multilayer structure mainly composed of one or more thermoplastic resin layers, and the innermost sealant layer is made of JIS. Tensile breaking strength of K7113 is 5-2
It is composed of a thermoplastic resin of 0 MPa. More preferably, at least one of the thermoplastic resin layers has a structure composed of a thermoplastic resin having a tensile elongation at break of 600% or less. Examples of the lid material in this case are as follows: Example 1: thermoplastic resin (outermost layer) / thermoplastic resin (intermediate layer) / thermoplastic resin (sealant layer) Example 2: paper / thermoplastic resin / metal foil / Thermoplastic resin / thermoplastic resin layer (sealant layer) Example 3: Various types such as thermoplastic resin (outermost layer) / paper / thermoplastic resin (sealant layer).

In this case, any number of layers may be used, and if necessary, a barrier resin layer, an adhesive resin layer, and the like may be laminated. Further, the material of the paper is not particularly limited. Further, a film in which an inorganic compound is laminated by a method such as vapor deposition to impart a barrier property can also be used.

As the thermoplastic resin layer used as the innermost sealant layer of the cover material, various resins can be used according to the material of the container. Examples include low-density polyethylene resin, medium-density polyethylene resin, high-density polyethylene resin, polypropylene resin, ethylene-propylene copolymer, ethylene-α-olefin copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer. Polymer,
There are various types such as an ethylene-methacrylate copolymer, an ethylene-acrylate copolymer, an ionomer resin, an ethylene-vinyl acetate copolymer, and a copolyester. These resins may be used alone or as a blend as needed. Further, low molecular weight petroleum resins, such as aliphatic petroleum resins, aromatic petroleum resins, copolymer petroleum resins, alicyclic petroleum resin resins, and rosin, polymerized rosin, hydrogenated rosin, rosin glycerin ester, and An appropriate amount may be blended with the above resin as a tackifier using the hydrogenated product or polymer, rosin pentaerythritol and rosins such as the hydrogenated product or polymer.

Here, JIS. Test specimens and measurement conditions for tensile strength at break and tensile elongation at break in K7113 are described in JIS. Follow the contents described in K7113.
For example, if the resin to be measured is a low density polyethylene resin, the thickness of the No. 2 test piece is 2.0 ± 0.2 mm, and the test speed is 2
00 mm / min. Tests for each resin are performed.

The sealant layer has a tensile strength at break of 5-2.
It is a thermoplastic resin of 0 MPa. By selecting within this range, stringing can be eliminated if the resin composition is such that stringing is generated by the cohesive peeling type peeling mechanism, and the strength at the time of opening (opening in FIG. 1) The starting point c) can be suppressed. When the pressure is 5 MPa or less,
The trigger strength is too weak, and it may peel off immediately due to impact such as dropping, or peel off with a slight trigger. On the other hand, when the pressure is 20 MPa or more, the strength at the time of opening is increased, and easy opening property cannot be imparted.

The tensile elongation at break of the sealant layer is 600%.
The following is preferred. More than 600% means that at the time of cohesive peeling shown in FIG. 1-A, the matrix resin of the sealant layer in which two or more thermoplastic resins are blended has a large elongation from opening to breaking. This means that stringing occurs.
Also, as shown in FIG.
When the interfacial peeling between the sealant layer 1b and the intermediate layer 2b is adopted, a large tensile elongation at break results in a decrease in easy-openability. A thermoplastic resin having a tensile strength at break or a tensile elongation at break within the above range may be interposed not only in the sealant layer but also in the intermediate layer.

In order to achieve both the function as a sealant layer and the relationship between easy-openability, a method of interposing a blend layer in which two or more kinds of thermoplastic resins are blended is exemplified. In the case of cohesive peeling, a suitable amount of a resin which is completely incompatible with or partially compatible with these resins may be added to a base resin to be a sealant layer or an intermediate layer. Also,
In the case of delamination, a method of blending a resin with one or both of the films so as to control the interfacial adhesive strength with the sealant layer or the intermediate layer may be used. In addition, one or both of the sealant layer and the intermediate layer are made of a graft copolymer such as an acid-modified product, a block copolymer, or a random copolymer to control the delamination strength between the sealant layer and the intermediate layer. It is also possible to impart delamination properties, in which case a component other than the acid component, or a copolymer containing both the acid component and the other component may be used.

When adopting cohesive peeling as an opening mechanism,
As the thermoplastic resin to be blended with the resin layer to be coagulated and peeled, a resin which is completely incompatible with or partially compatible with these resin layers is selected. Depending on the base resin, examples include low-density polyethylene resin, medium-density polyethylene resin, high-density polyethylene resin, ethylene-α-olefin copolymer, polybutene resin, polypropylene resin, ethylene-propylene copolymer, and polyethylene terephthalate. Polyester resin, polyamide resin, acid copolymer such as ethylene-acrylic acid copolymer or ethylene-methacrylic acid copolymer or its esterified product, ethylene-vinyl acetate copolymer or its saponified product, polystyrene resin, polymethyl methacrylate Resins and the like can be used, and in addition to the above-mentioned resins, various resins such as acid-modified products can be used.

When cohesive peeling is employed, stringiness may occur in these blend layers at the time of opening. As described above, in order to eliminate stringing, techniques such as reducing the thickness of the blend layer or reducing the domain of the blend layer are mentioned. By setting the tensile elongation at break to ２０20 MPa and 600% or less, stringing can be eliminated without using these methods.

When delamination is employed, one or both of the above resins may be blended so as to control the interfacial adhesive strength between the sealant layer and the intermediate layer. In addition, using either a graft copolymer such as an acid-modified product, a block copolymer, or a random copolymer for one or both of the sealant layer and the intermediate layer, and controlling the peel strength between the sealant layer and the intermediate layer, delamination In this case, a component other than the acid component, or a copolymer containing both the acid component and the other component may be used.

Considering the ease of opening these lids, the opening strength of the lid is preferably 1 to 15 N / 15 mm. If the strength is less than 1 N / 15 mm, the adhesive strength is inferior.
When it is N / 15 mm or more, the easy opening property is poor. The opening strength is preferably set to the above range, but in the case where the adherent is mainly composed of paper such as a paper cup, if the opening strength is too strong, the paper may peel off. The setting of the opening strength is preferably about 1 N to 5 N / 15 mm.

The method of producing the lid material of the present invention can employ various methods. Basically, the above-mentioned content is used as a base material with a laminated body previously laminated by a method such as dry lamination or extrusion lamination. A method of extrusion laminating a thermoplastic resin is used. At this time, when the film thickness is reduced by the cohesive peeling type or when the film is delaminated, it can also be obtained by laminating by a co-extrusion technique. There are no restrictions on the manufacturing method for these lids.

In consideration of the workability and thermal stability of the material of the sealant layer, if necessary, an antioxidant, a stabilizer, a lubricant, an antiblocking agent, an antistatic agent, a cloud inhibitor, a tackifier may be used. It is also possible to add additives such as fillers and coloring agents.

The container "a" to be used as the cover material of the lid material of the present invention is made of polyethylene resin, polypropylene resin, polyethylene terephthalate resin (especially crystallized PET: C-PET),
Examples include cups and trays obtained by injection molding or vacuum compression molding made of polystyrene resin or the like. However, the present invention is not limited to these resin types or container types, and can be used for containers made of various resins by selecting a sealant type. Further, the container can be used as a lid material of a container such as a blister pack.

As described above, recently, in addition to the above-described cups and trays, paper cups and paper trays in which polyethylene resin, polypropylene resin, and crystallized polyethylene terephthalate resin are laminated on paper have come to be seen. Was. The lid of the present invention can be used for such a lid. However, in the case of a container mainly made of paper such as a paper cup, there is a possibility that a problem of peeling of the paper at the time of opening may occur.
About 5 N / 15 mm is preferable. In the case of a paper cup, when forming a cup from a blank state (see FIG. 2), the adhesive margin e provided on the side is heat-sealed.
The glue margin e causes the paper cup flange g to form a step h (see FIG. 3), which may reduce the sealing performance. In order to solve this problem, JIS. 190 ° C. according to K7210, 21.1
By making the thermoplastic resin having an MI of 68 to 80 at MI of 20 to 80, the sealant layer is melted at the time of sealing the lid material, and the fluidity thereof is high, so that the step h can be filled and the sealing property is improved. .

[0024]

Embodiments of the present invention will be described below, but the technical scope of the present invention is not limited to these embodiments.

Example 1 A low-density polyethylene having a thickness of 20 μm laminated by extrusion lamination on a biaxially stretched polyethylene terephthalate film (25 μm) was used as an adherend requiring seal strength measurement. As the innermost sealant layer of the cover material, JIS. K7113 has a tensile strength at break of 9 MPa, a tensile elongation at break of 450%, and JIS. 190 ° C, 21.168 N according to K7210
Using a low-density polyethylene resin having an MI of 70,
In order to further provide easy-opening properties, 30
wt% was added. Further, since this sealant layer has high fluidity, it was laminated on the base material of the lid material at an extrusion temperature of 280 ° C. by co-extrusion with a low-density polyethylene resin having an MI of 5 (MI = 5 low-density polyethylene resin layer 30 μm). , Sealant layer 10 μm). Thereafter, the laminate was sealed with the above-described sheet.
130-180
The heat seal strength at ℃ was measured. The sealing pressure at that time is 0.15 MPa, and the sealing time is 1 second. This heat-sealed material was sampled into a strip having a width of 15 mm,
A peel test was performed. Table 1 shows the adhesive strength and the opening mechanism at that time. As a structure of the lid material, a material obtained by laminating aluminum foil on paper (basis weight 80 g / cm 2) was used as the base material. For the composition of the sealant, a lid material was prepared by co-extrusion of an aluminum foil and an adhesive ethylene-acrylic acid copolymer using the above-mentioned blended product. As a container to be adhered, a paper cup made from a raw material obtained by laminating a low-density polyethylene resin on paper was actually used. A cup sealer was used for heat sealing between the container and the lid member. The sealing temperature was 130 ° C., the sealing pressure was 0.15 MPa,
Sealing was performed with a sealing time of 1 second. The layer thickness at this time was the same as in the case described above. In this case, the layer thickness of the ethylene-acrylic acid copolymer was 30 μm. The adhesion at the step was confirmed with a leak chuck liquid. Regarding the seal strength, the above-mentioned adherend requiring the seal strength measurement was prepared, and the adherend was changed. At this time, heat sealing between the adherend and the lid material was performed using a heat sealer, and heat sealing was performed under the same conditions as the above-described cup sealer. The results are summarized in Table 1.

Example 2 The thermoplastic resin serving as the sealant layer had a tensile strength at break of 9 MPa and a tensile elongation at break of 100.
%, And the same as Example 1 except that MI was set to 50.

Example 3 The thermoplastic resin forming the sealant layer had a tensile strength at break of 10 MPa and a tensile elongation at break of 10 MPa.
Same as Example 1 except that 0% and MI were set to 35.

Example 4 The thermoplastic resin serving as a sealant layer had a tensile strength at break of 9 MPa and a tensile elongation at break of 350.
%, And the same as Example 1 except that MI was set to 20.

Example 5 A thermoplastic resin serving as a sealant layer was prepared to have a tensile strength at break of 18 MPa and a tensile elongation at break of 50.
A polypropylene resin with 0% and MI at 190 ° C. of 30 was used. A polystyrene resin was used for a blend layer (intermediate layer) for imparting easy-opening properties to the sealant layer, and the addition amount was 30 wt%. At this time,
The sealant layer was formed by coextrusion with an extrusion grade PP (MI at 15 at 190 ° C.). This laminate was used as a seal for measuring the seal strength and for the cup. As an adherend, a film obtained by laminating a CPP film on a biaxially stretched polyethylene terephthalate resin by dry lamination for use in measuring the seal strength is used. As an adherend serving as a cover material, polypropylene formed by injection molding is used. A cup was used. Other than that is the same as the first embodiment.

Example 6 A low-density polyethylene resin having a tensile rupture strength of 7 MPa, a tensile rupture elongation of 420% and an MI of 40 was used as a thermoplastic resin to be a sealant layer. In addition, a blend layer in which 30 wt% of a polymethyl methacrylate resin was blended in low density polyethylene having an MI of 5 was provided on the upper layer (an easy-opening intermediate layer and a sealant layer were separate layers). These layers have a sealant layer thickness of 20 μm and an intermediate layer (blend layer) of 20 μm. Other than that is the same as the first embodiment.

Example 7 A low-density polyethylene resin having a tensile rupture strength of 11 MPa, a tensile rupture elongation of 550%, and an MI of 30 was used as a thermoplastic resin to be a sealant layer, and the sealant layer was provided with easy-opening properties. To this end, 30 wt% of a polypropylene resin is added, and an ethylene-α-olefin copolymer having a density of 0.902 g / cm 3 is added as a modifier to the blend resin (low-density polyethylene resin +
10 parts by weight were added to 100 parts by weight of (polypropylene resin). Other than that is the same as the first embodiment.

Example 8 A thermoplastic resin to be a sealant layer has a tensile strength at break of 8 MPa and a tensile elongation at break of 9
Low-density polyethylene resin with 0% and MI of 40 was used.
On top of that, as an intermediate layer, a blend layer was prepared by adding 30 wt% of a polystyrene resin to low density polyethylene having an MI of 5. These two layers were extruded with a low density polyethylene resin having an MI of 5 by three layer coextrusion. At that time, the layer thickness was 20 μm for the sealant layer, 1 for the intermediate layer (blend layer),
Extruded with 0 μm, 30 μm MI = 5 low density polyethylene layer. Other than that is the same as the first embodiment.

[0033]

[Table 1]

The following can be said from these results. JIS of thermoplastic resin to be innermost sealant layer. K711
3, the tensile breaking strength is 5 to 20 MPa, more preferably the tensile breaking elongation is 600% or less, and the easy-opening layer provided on the lid material is made into a blended layer.
It is possible to provide a cohesive peeling type easy-opening mechanism of up to 15 N / 15 mm. These lids can provide easy opening at the initial trigger of opening strength without stringing at the time of opening.

Further, as a cover material for a paper cup, J
IS. By setting MI at 20 ° C. and 2160 g load according to K7210 at 20 ° C. to 20 to 80, it is possible to fill a step generated in a margin for heat sealing in a paper cup flange portion, and to produce a lid material having excellent sealing properties. It is possible. Further, as shown in Example 5, this lid material can be used not only for a paper cup but also for a cup molded body (such as injection molding). In the above embodiments, examples of adherends such as polyethylene and polypropylene are mainly shown. However, by changing the type of the sealant layer in various ways, it is possible to develop the cover material such as a paper tray in which polyester is laminated. It is.

[0036]

As described above, the present invention has excellent practical effects as described below. In a lid material such as a cup and a tray having a multilayer structure mainly composed of a thermoplastic resin layer, a lid material capable of not only providing easy-opening properties but also eliminating problems such as stringing that occurs at the time of opening. can do. Further, the opening mechanism can be applied not only to cohesive peeling but also to types such as interlayer peeling.
In the future, many packaging materials such as paper cups and paper trays will tend to appear on the market, and the contents will be filled with everything. In such an era, the lid of the present invention can be said to be a wonderful lid in that it can impart functions such as easy opening while having adhesion.

[Brief description of the drawings]

FIG. 1A is an explanatory view showing a type of opening in which the sealant layer of the present invention cohesively peels off. B is an explanatory diagram showing the opening of the type of the present invention in which the intermediate layer is cohesively peeled or the type in which the sealant layer and the intermediate layer are delaminated.

FIGS. 2A, 2B, 2C, and 2D are explanatory diagrams of processes from paper cup production to sealing of a lid material.

FIG. 3 is a schematic diagram showing a decrease in adhesion between a paper cup and a lid member.

[Explanation of symbols]

 a ‥‥‥ container b ‥‥‥ lid material 1b 材 sealant layer 2b ‥‥‥ intermediate layer c ‥‥ opening start point d ‥‥‥ tab e ‥‥‥ glue margin of paper cup blank f ‥‥‥ bottom lid g {Flange h} Step

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Nobuo Furusawa, Inventor 1-5-1, Taito, Taito-ku, Tokyo Inside Toppan Printing Co., Ltd. (72) Inventor Mamoru Sekiguchi 1-15-1, Taito, Taito-ku, Tokyo Letterpress F-term (reference) in Printing Co., Ltd. BB151 BB152 BB172 BB231 BC032 BG062 CF051 CF062 CL002 FD010 FD030 FD070 FD090 FD100 FD170 FD340 GF00 GG01 GJ02

Claims (9)

[Claims] 1. A cover material having a multilayer structure mainly composed of a thermoplastic resin layer, wherein a thermoplastic resin layer forming a sealant layer of the cover material is formed according to JIS. A lid material comprising a thermoplastic resin having a tensile strength at break of K7113 of 5 to 20 MPa. 2. The lid material according to claim 1, wherein at least one of the thermoplastic resin layers is made of JIS. A lid material comprising a thermoplastic resin having a tensile elongation at break of K7113 of 600% or less. 3. The lid material according to claim 1, wherein at least one of the thermoplastic resin layers having a multilayer structure comprises a blend layer of two or more thermoplastic resins. 4. The lid material according to claim 1, 2 or 3,
The sealant layer is a polyethylene resin, a polypropylene resin, an ethylene-α-olefin copolymer, an acid-modified product of these olefin-based resins, an ethylene-vinyl acetate copolymer,
A lid material characterized in that it is a simple substance of ethylene-α, β-unsaturated carboxylic acid or its esterified product, ionic crosslinked product, copolymerized polyester or a blend layer containing these as a main component. 5. The lid according to claim 1, wherein the lid has a peel strength of 1 between the lid and a container bonded to the lid.
A lid material characterized by being 15 N / 15 mm. 6. The lid according to claim 1, wherein the separation between the lid and the container is a cohesive separation of the blend layer. 7. A lid material according to claim 1, wherein the peeling of the lid material from the container is an interlayer peeling of a multilayered thermoplastic resin layer constituting the lid material. A lid material characterized by the following. 8. The lid material according to claim 1, wherein the container to which the lid material is adhered is a cup or tray made of polyethylene resin, polypropylene resin, polyethylene terephthalate resin, or polystyrene resin. A lid material characterized by that. 9. The lid material according to claim 1, wherein the container to which the lid material is adhered is a paper cup or paper tray on which polyethylene resin, polypropylene resin, or polyethylene terephthalate resin is laminated. A lid material characterized by that.