JP5380866B2 - LAMINATE, CLOSED CLOSED CONTAINING THE SAME, AND CLOSED CONTAINER - Google Patents

Description

  The present invention relates to a laminate, a lid for a sealed container using the same, and a sealed container.

Conventionally, in a sealed container that stores food such as yogurt and pudding, a laminated body in which a heat seal layer is laminated using an aluminum foil as a base material is used as a lid. However, in recent years, in order to collect and reuse used packaging materials, development of a lid material that does not use an aluminum foil as a base material has been studied (see Patent Document 1).
For example, Patent Document 1 describes an aluminum-less lid material made of a laminate containing a predetermined amount of a styrene resin and a conjugated diene monomer in a base material layer.
JP 2003-267422 A

However, there is room for improvement in the shape retention of the lid material when forming the lid material from the laminate, the stability of the sealing strength when the lid material is sealed to the container body, the easy peelability, and the like.
In view of the above problems, an object of the present invention is to provide a laminate capable of providing a lid material with improved shape retention and easy peelability, and a lid for a sealed container and a sealed container using the same. To do.

The present inventors have found that the above-described problems can be achieved by adopting the following configuration, and have completed the present invention.
That is, the present invention has a seal layer formed from a resin composition containing a thermoplastic resin, an adhesive layer, and a base material layer, and the seal layer and the base material layer are arranged via the adhesive layer. The base material layer contains an amorphous thermoplastic resin A having a glass transition point of 50 ° C. to 150 ° C., the thickness of the base material layer is 30 μm to 200 μm, and The thickness of the whole laminate is 60 μm to 250 μm, and provides a lid for a sealed container and a sealed container using the laminate.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to improve the shape retention property of a cover material at the time of forming a cover material from a laminated body, and easy peelability.

[Laminate]
The laminate according to the present invention has a base material layer containing a thermoplastic resin, an adhesive layer, and a seal layer, and the base material layer and the seal layer are arranged via the adhesive layer. . The thickness of the laminate is preferably 80 μm to 240 μm, more preferably 100 μm to 230 μm. Each layer will be described in detail below.

<Base material layer>
The base material layer in this invention is a layer located in the side which does not contact | abut the airtight container main body, when a cover material is formed from a laminated body. This base material layer preferably has shape retention in order to make it easier to open and eat and drink.
This base material layer is formed from a resin composition containing a thermoplastic resin, and the thermoplastic resin contains an amorphous thermoplastic resin A having a glass transition point of 50 ° C to 150 ° C. Yes. By including the amorphous thermoplastic resin A having a glass transition point in the above range, it is possible to improve the rigidity of the lid material and develop the shape retention of the lid material. The glass transition point is preferably 60 ° C to 140 ° C, and more preferably 70 ° C to 120 ° C.
The term “amorphous” in the present invention means that no endothermic peak or melting point is observed in the measurement with a differential scanning calorimeter (DSC) of the resin. Moreover, the value measured by the differential scanning calorimeter (DSC) of the resin is used as the “glass transition point” in the present invention.

Examples of the amorphous thermoplastic resin A used for the base material layer include styrene resins and ester resins. These can be used alone or in combination of two or more.
Examples of the styrene resin include polystyrene, rubber-modified polystyrene, and a mixture thereof. Here, the rubber-modified polystyrene is a resin in which soft component particles obtained from a styrene polymer and a rubber-like polymer are dispersed in a styrene polymer forming a matrix, and so-called impact-resistant polystyrene. (High Impact Polystyrene: HIPS).
In rubber-modified polystyrene, styrene is generally used as the styrene monomer constituting the styrene polymer forming the matrix, but alkyl substitution such as o-methyl styrene, m-methyl styrene, p-methyl styrene, etc. Styrenes may be used. As the rubber-like polymer contained in the soft component particles, a butadiene polymer, a styrene-butadiene copolymer, an isoprene polymer, a styrene-isoprene copolymer, or the like can be used. Moreover, a styrene-butadiene copolymer and a butadiene polymer can be used in combination. As the butadiene polymer, either a so-called high cis polybutadiene having a high cis content or a so-called middle cis polybutadiene having a cis content of about 35% can be used.

The ester resin is produced by polycondensation of a dibasic acid and a polyhydric alcohol. Examples of the dibasic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid, and aliphatic dicarboxylic acids such as adipic acid. Examples of the polyhydric alcohol include diols such as ethylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, pentaethylene glycol, 2,2-dimethyltrimethylene glycol, hexamethylene glycol, and neopentyl glycol. . Said dibasic acid and polyhydric alcohol are used by arbitrary combinations. Specifically, terephthalic acid / ethylene glycol copolymer, terephthalic acid / ethylene glycol / 1,4-cyclohexanedimethanol terpolymer, 2,6-naphthalenedicarboxylic acid / ethylene glycol copolymer, terphthalic acid / Examples include 1,4-butanediol copolymerization.
Among these, it is more preferable to use rubber-modified polystyrene and terephthalic acid / ethylene glycol / 1,4-cyclohexanedimethanol terpolymer from the viewpoints of extrusion processability and shape retention of the lid. From the viewpoint of recyclability, when the closed container body is formed of an amorphous thermoplastic resin, it is more preferable to use the same resin as the amorphous thermoplastic resin as the amorphous thermoplastic resin A. For example, when rubber-modified polystyrene of a styrene resin is used for the sealed container body, it is more preferable to use rubber-modified polystyrene as the amorphous thermoplastic resin A.

In addition to the amorphous thermoplastic resin A, the resin composition for forming the base material layer includes other thermoplastics such as a polyamide resin, a polyester resin, a polycarbonate resin, a polyolefin resin, an ionomer resin, and a biodegradable resin. It may contain a resin.
Here, examples of the polyamide-based resin include 6 nylon, 66 nylon, 6-66 nylon, polymetaxylylene adipamide, polymetaxylylene pimeramide, polymetaxylylene azelamide, polyparaxylylene azelamide, polyparaxylyl. Lenddecanamide, metaxylylene / paraxylylene adipamide copolymer, metaxylylene / paraxylylene pimeramide copolymer, metaxylylene / paraxylylene azelamide copolymer, metaxylylene / paraxylylene sepacamide copolymer , Etc. Examples of the polyester resin include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene terephthalate / isophthalate copolymer, and the like.
Examples of the polyolefin resin include polyethylene resins such as very low density polyethylene (VLDPE), linear low density polyethylene (LLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE). It is done. Also, ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate copolymer (EMA), ethylene-acrylic Acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-glycidyl methacrylate copolymer (E-GMA), ethylene-vinyl acetate-glycidyl methacrylate copolymer (E-VA-GMA), Ethylene-maleic anhydride copolymer (E-MAH), ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH), propylene homopolymer, copolymer of propylene and other α-olefins Polyolefin resins such as ethylene and norbornenes and tetracyclodone Cyclic olefins such as random copolymers with cyclic olefins such as cenes and derivatives thereof, cyclic olefin ring-opening copolymers, hydrogenated cyclic olefin ring-opening copolymers, and graft-modified products of these copolymers Resin is also mentioned as said polyolefin resin.
Examples of the ionomer resin include a metal neutralized product of an ethylene-acrylic acid copolymer and a metal neutralized product of an ethylene-methacrylic acid copolymer. Examples of the biodegradable resin include polylactic acid (“LACEA” manufactured by Mitsui Chemicals), cellulose acetate, (“Cell Green PCA” manufactured by Daicel Chemical), and modified starch (“Corn Pol” manufactured by Cornstarch Japan).

  The content of the amorphous thermoplastic resin A in the resin composition forming the base material layer is preferably 40% by mass to 100% by mass, more preferably 50% by mass to 100% by mass, More preferably, it is 55 mass%-100 mass%.

  The resin composition may contain additives such as a lubricant, an antistatic agent, an antioxidant, a heat stabilizer, an ultraviolet absorber, an antibacterial agent, and an antifogging agent.

  The thickness of the base material layer with respect to the laminate is preferably 30 μm to 200 μm, more preferably 40 μm to 180 μm, and still more preferably 50 μm to 160 μm. By making the thickness of the base material layer within the above range, it is possible to impart shape retention to the lid material.

<Adhesive layer>
The adhesive layer in the present invention is a layer that is located between the base material layer and the seal layer and adheres the base material layer and the seal layer. Examples of the adhesive layer include a resin composition containing a styrene-based elastomer and / or an ethylene-unsaturated carboxylic acid ester copolymer. Among these, it is preferable to use an ethylene-unsaturated carboxylic acid ester copolymer.
Here, as the styrene-based elastomer, hydrogenated styrene-butadiene-block copolymer (SEBS), styrene-ethylene-propylene-block copolymer (SEP, SEPS), hydrogenated styrene-butadiene-rubber (HSBR), etc. Is mentioned. The ethylene-unsaturated carboxylic acid ester copolymer includes ethylene / methyl acrylate copolymer, ethylene / methyl methacrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / ethyl methacrylate copolymer. , Ethylene / n-butyl acrylate copolymer, ethylene / n-butyl methacrylate copolymer, and the like. The content of ethylene-derived structural units in the ethylene / unsaturated carboxylic acid ester copolymer is preferably 60% by mass to 80% by mass.

  The resin composition forming the adhesive layer contains a thermoplastic resin such as an ethylene resin, a propylene resin, an ester resin, and a styrene resin in addition to the styrene elastomer and the ethylene-unsaturated carboxylic acid ester copolymer. It may be.

  The contents of the styrene elastomer and the ethylene-unsaturated carboxylic acid ester copolymer in the adhesive layer are each preferably 10% by mass to 100% by mass, and more preferably 30% by mass to 100% by mass. . When the styrene elastomer and the ethylene-unsaturated carboxylic acid ester copolymer are used in combination, the total content is preferably 20% by mass to 100% by mass, and 40% by mass to 100% by mass. % Is more preferable. When the styrene elastomer and the ethylene-unsaturated carboxylic acid ester copolymer are used in combination, the ratio of each content (styrene elastomer: ethylene-unsaturated carboxylic acid ester copolymer) is 1: 9 to It is preferably 9: 1, more preferably 2: 8 to 8: 2, and still more preferably 4: 6 to 6: 4.

  The resin composition may contain additives such as a lubricant, an antistatic agent, an antioxidant, a heat stabilizer, an ultraviolet absorber, an antibacterial agent, and an antifogging agent.

  The thickness of the adhesive layer with respect to the laminate is preferably 5 μm to 100 μm, more preferably 10 μm to 85 μm, and still more preferably 10 μm to 70 μm. By setting the thickness of the adhesive layer in the above range, a laminate having an appropriate interlayer strength can be produced.

<Sealing layer>
The sealing layer in the present invention is a layer that comes into contact with the sealed container body when the lid member is formed from the laminated body, and is a layer that is bonded to the extent that the lid member can be manually opened from the sealed container body. Say. The seal layer is formed of a resin composition containing a thermoplastic resin, and the resin composition preferably contains an amorphous thermoplastic resin B having a glass transition point of 50 ° C to 120 ° C. Is.

  As the amorphous thermoplastic resin B, a styrene resin, an ester resin, etc. are mentioned like the thermoplastic resin A used for a base material layer. These can be used alone or in combination of two or more. Moreover, it is preferable to use the same amorphous thermoplastic resin as the amorphous thermoplastic resin A from the viewpoint of recyclability. Furthermore, when the sealed container body is formed of an amorphous thermoplastic resin, it is preferable to use the same amorphous thermoplastic resin as the amorphous thermoplastic resin and the amorphous thermoplastic resin A. For example, when impact-resistant polystyrene of a styrene resin is used for the closed container body, it is more preferable to use impact-resistant polystyrene as the amorphous thermoplastic resin B.

  The resin composition may contain additives such as a lubricant, an antiblocking agent, an antistatic agent, an antioxidant, a heat stabilizer, an ultraviolet absorber, an antibacterial agent and an antifogging agent.

  The thickness of the sealing layer with respect to the laminate is preferably 1 μm to 15 μm, more preferably 3 μm to 10 μm, and still more preferably 3 μm to 8 μm. By setting the thickness of the seal layer in the above range, the adhesive layer and the seal layer can be delaminated when the lid member is peeled from the sealed container. This delamination enables sealing stability and easy peelability when the lid material is sealed to the container body.

  In the laminate according to the present invention, the ratio (a / c) of the thickness a of the sealing layer to the thickness c of the base material layer is preferably 1/6 to 1/50, more preferably 1/6 to 1/30. By setting the ratio of the thickness a of the sealing layer to the thickness c of the base material layer in such a range, the shape retention can be expressed in the lid.

The laminate according to the present invention is obtained by sequentially laminating a seal layer, an adhesive layer, and a base material layer. When the lid is formed, a surface protective layer obtained by printing on a film made of a thermoplastic resin may be disposed on the base material layer located on the top (outside), The second or third adhesive layer may be provided between the base material layer and the adhesive layer, and between the adhesive layer and the seal layer.
Here, the surface protective layer is preferably made of nylon, polyethylene terephthalate, polypropylene, ethylene-vinyl alcohol copolymer or the like. The second or third adhesive layer is preferably made of the same resin composition as the above-described adhesive layer.

  The thickness of the surface protective layer for the laminate is preferably 5 μm to 50 μm, more preferably 10 μm to 40 μm, and even more preferably 12 μm to 35 μm. The thicknesses of the second adhesive layer and the third adhesive layer are each preferably 5 μm to 100 μm, more preferably 10 μm to 85 μm, and more preferably 10 μm to 70 μm.

<Manufacture of laminates>
The laminate according to the present invention can be produced by a conventionally known processing method such as an inflation method by coextrusion, a T-die method, or a press method. Alternatively, each layer may be separately formed into a film shape, manufactured separately, and then joined by a laminator or the like. The film for each layer of the laminate can be produced by various methods such as an inflation method, a T-die method, and a press method.

[Cover materials and sealed containers]
The lid material according to the present invention can be obtained by molding the laminated body into a predetermined shape. For example, it can be obtained by punching the laminated body into a circle and then drawing it into a shape (for example, a truncated cone shape or a cylindrical shape) that can cover the opening of the sealed container body using a molding machine. At this time, the seal layer is formed so as to be located inside.

In addition, the sealed container according to the present invention is obtained by covering the lid material so that the seal layer side of the lid material is in contact with the opening of the sealed container body, and bonding the seal layer to the sealed container body by a predetermined method. The sealing layer is preferably adhered by heat sealing.
The material of the sealed container main body is not particularly limited as long as it is a container that can be heat-sealed with the seal layer. Specifically, for example, a sheet made of a thermoplastic resin such as a styrene polymer, polyester, polyamide or the like, a sheet having a shape such as a tray, a cup, or a bottle can be used. The hermetic container body may be a single layer or a laminate composed of two or more thermoplastic resins.
Among these, from the viewpoint of recyclability, it is preferable to use a sealed container body containing the same resin as the seal layer, and it is more preferable to use a sealed container body containing a resin common to the seal layer, the adhesive layer, and the base material layer. .

EXAMPLES Hereinafter, although this invention is demonstrated based on an Example, this invention is not limited to these Examples.
[Example 1]
As a resin composition for forming the sealing layer, 20 parts by mass of impact-resistant polystyrene (H550 manufactured by Nippon Polystyrene Co., Ltd.) and 80 parts by mass of polystyrene (G440K manufactured by Nippon Polystyrene Co., Ltd.) are pellet-blended (thermoplastic resin B). ) Was used.
As a resin composition for forming an adhesive layer, ethylene / methyl acrylate copolymer (manufactured by Sumitomo Chemical Co., Ltd., trade name ACRIFT: CG4002, content of 31 mass parts of structural unit derived from methyl acrylate, melt flow rate (190 C, 2.16 kgf) = 5 g / 10 min) 55 parts by mass, linear low density polyethylene (Sumitomo Chemical Co., Ltd., trade name Sumikasen E: FV401, melt flow rate (190 ° C., 2.16 kgf) = 4 g / 10 Min) 17 parts by mass, 3 parts by mass of styrene-isoprene block copolymer Septon 2104 (manufactured by Kuraray Co., Ltd.), 22 parts by mass of impact-resistant polystyrene (manufactured by Nippon Polystyrene Co., Ltd., H550), and cylinder temperature and die temperature of 220 ° C. Pellets melt-mixed using the same direction 45 mm Φ twin screw extruder set in the above.
As the resin composition for forming the base material layer, the impact-resistant polystyrene (H550 manufactured by Nippon Polystyrene Co., Ltd., glass transition point 100 ° C.) used in the adhesive layer was used (thermoplastic resin A).

Using the above materials, 3 types, 3 layers coextrusion T die cast processing machine (Extruder A: 60 mmφ, Extruder B: 60 mmφ, Extruder C: 90 mmφ, Layer structure = Extruder A / Extruder B / Extruder C) The resin composition for the sealing layer (thermoplastic resin B) in the extruder A, the resin composition for the adhesive layer in the extruder B, and the resin composition for the base material layer (thermoplastic resin A in the extruder C) ) To produce a laminate in which a base material layer, an adhesive layer, and a seal layer were sequentially laminated. The processing temperatures at this time were Extruder A: 220 ° C., Extruder B: 190 ° C., Extruder C: 230 ° C., and the die temperature was 250 ° C.
Subsequently, the substrate layer side of the laminate was subjected to corona discharge treatment so that the wetting tension was 45 dyn / cm. The obtained laminate had a seal layer thickness of 5 μm, an adjacent layer thickness of 10 μm, a base material layer thickness of 100 μm, and an overall thickness of 115 μm.

Furthermore, the surface protection layer was provided in the following procedures using the coater by Yasui Seiki Co., Ltd.
First, an aliphatic ester-based coating agent (main agent = Takelac A-515, Mitsui Takeda Chemical Co., Ltd., hardener = Takenate A-50, Takenate A-50, ethyl acetate 10: 1: 15 each. A polyester film (unitika Ltd., trade name “PTMX”, thickness: 12 μm, width: 330 mm) serving as a surface protective layer was applied to a polyester film (mixed in a mass ratio and sufficiently mixed). Next, this was pressure-bonded to the corona-treated surface of the laminate, and then heated in an oven at 40 ° C. for 24 hours to obtain a lid material.

[Example 2]
The resin composition used in Example 1 was used as the resin composition for forming the seal layer.
The resin composition used in Example 1 was used as the resin composition for forming the adhesive layer.
As a resin composition for forming the base material layer, an ethylene / methyl acrylate copolymer (trade name ACRlift: CG4002, manufactured by Sumitomo Chemical Co., Ltd.), 31 mass parts of a structural unit derived from methyl acrylate, melt flow rate ( 190 ° C., 2.16 kgf) = 5 g / 10 min) 5 parts by mass, linear low density polyethylene (manufactured by Sumitomo Chemical Co., Ltd., trade name Sumikasen E: FV202, melt flow rate (190 ° C., 2.16 kgf) = 2 g / 10 minutes) 3 parts by mass, 2 parts by mass of styrene-isoprene block copolymer Septon 2104 (manufactured by Kuraray Co., Ltd.), 90 parts by mass of impact-resistant polystyrene (H550 produced by Nippon Polystyrene Co., Ltd.) Pellets obtained by melt mixing using a screw extruder were used.

Three-type three-layer coextrusion inflation machine (die diameter 150φ, die slip opening 2 mm, extruder A: 50 mmφ, extruder B: 50 mmφ, extruder C: 50 mmφ, layer configuration = extruder A (inflation tube inner layer) / Extruder B / Extruder C (inflation tube outer layer)) Extruder A resin composition for sealing layer, Extruder B resin composition for adhesive layer, Extruder C resin composition for base material layer Was added to produce a laminate in which a base material layer, an adhesive layer, and a seal layer were laminated in this order. The processing temperatures at this time were Extruder A: 200 ° C., Extruder B: 190 ° C., Extruder C: 220 ° C., and the die temperature was 210 ° C.
Subsequently, the substrate layer side of the laminate was subjected to corona discharge treatment so that the wetting tension was 45 dyn / cm. The obtained laminate had a seal layer thickness of 5 μm, an adjacent layer thickness of 28 μm, a base material layer thickness of 37 μm, and an overall thickness of 70 μm. And the lid | cover material was obtained by the procedure similar to Example 1. FIG.

[Comparative Example 1]
As the resin composition for forming the seal layer, the resin composition (C-1) used in Example 1 was used.
The resin composition used in Example 1 was used as the resin composition for forming the adhesive layer.
As a resin composition for forming a base material layer, linear low-density polyethylene (trade name Sumikasen E: FV202 manufactured by Sumitomo Chemical Co., Ltd., melt flow rate (190 ° C., 2.16 kgf) = 2 g / 10 min) 70 parts by mass , 10 parts by mass of styrene-isoprene block copolymer Septon 2104 (manufactured by Kuraray Co., Ltd.) and 20 parts by mass of impact-resistant polystyrene (H550 manufactured by Nippon Polystyrene Co., Ltd.) were used in the same manner as in Example 1 using a twin screw extruder. Pellets obtained by melt mixing were used.

  Using a three-kind three-layer coextrusion inflation machine similar to Example 2, a laminate in which a base material layer, an adjacent layer, and a seal layer were laminated in order was produced. The obtained laminate had a seal layer thickness of 5 μm, an adjacent layer thickness of 30 μm, a base material layer thickness of 40 μm, and an overall thickness of 75 μm. A lid was obtained in the same manner as in Example 1.

The laminated films obtained in Examples 1 and 2 and Comparative Example 1 were evaluated by the following methods. The results are shown in Table 1.
<Easily peelable>
As the adherend, a 400 μm HIPS sheet (H640: manufactured by Nippon Polystyrene Co., Ltd.) cut into 70 × 90 mm was used. This adherend and the sealing layer of the obtained lid material are brought into intimate contact with each other, a strip of 0 mm in width at a pressure of 3 kg / cm ² , a time of 1 second and a seal temperature of 160 ° C. and 180 ° C. (90 mm length of the adherend) In a direction parallel to the heat). A 15 mm × 70 mm test piece was cut out at a 15 mm width interval so as to include the seal portion perpendicular to the belt-shaped seal portion.
Using a Toyo Seiki Co., Ltd. Autograph AGS500D type tensile tester, the peel strength when peeled 180 ° at a tensile rate of 300 mm / min in an atmosphere at 23 ° C. was measured. The easy peelability was determined to be excellent when the peel strength was 5 N / 15 mm to 30 N / 15 mm width, and it was judged to be excellent in balance between the sealing strength of the container and the lid material peeling, and x outside the peel strength range.

<Shape retention test>
A container made of resin (polystyrene) having a lid material cut into a circle having a diameter of 70 mm and a circular opening having an inner diameter of 62 mm surrounded by a flange portion having a width of 3 mm was prepared. The test piece was heat-sealed on the flange portion of the container at a temperature of 180 ° C. and a load of 100 kgf for 1 second and sealed.
Next, one end of the test piece is pinched while the container is fixed, and the test piece is peeled off from the lower container by pulling it toward the direction of 45 ° with respect to the unpeeled portion of the test piece. The opening ratio of the lower container is 50%. The sealed container was opened until ˜75% was reached. After opening, the bending angle A ′ of the test piece released from the external force was measured. If the bending angle was 45 ° C. or higher, it was judged that the shape-retaining property was excellent, and “good” was marked, and less than 45 ° C. was marked “x”.

Claims (7)

It has a seal layer formed from a resin composition containing a thermoplastic resin, an adhesive layer, and a base material layer, and the seal layer and the base material layer are laminated bodies arranged via the adhesive layer. There,
The base material layer contains an amorphous thermoplastic resin A having a glass transition point of 50 ° C to 150 ° C,
The content of the amorphous thermoplastic resin A in the resin composition forming the base material layer is 40% by mass to 100% by mass,
The thermoplastic resin forming the sealing layer is an amorphous thermoplastic resin B having a glass transition point of 50 ° C to 150 ° C,
The laminate having a thickness of 30 μm to 200 μm, and a thickness of the entire laminate of 60 μm to 250 μm. The laminate according to claim 1, wherein the amorphous thermoplastic resin A and the amorphous thermoplastic resin B are at least one selected from the group consisting of a styrene resin and an ester resin. The laminate according to claim 1 or 2 , wherein a ratio (a / c) of the thickness a of the sealing layer and the thickness c of the base material layer is 1/6 to 1/50. The laminate according to any one of claims 1 to 3, wherein the adhesive layer contains a styrene elastomer and / or an ethylene-unsaturated carboxylic acid ester copolymer. The lid | cover material for airtight containers consisting of the laminated body in any one of Claim 1 to 4 . A sealed container comprising the lid for a sealed container according to claim 5 and a container main body. The sealed container according to claim 6 , wherein the container main body contains the amorphous thermoplastic resin B constituting the seal layer of the lid for the sealed container.