JP2019181939A - Laminate, lid material for closed vessel and closed vessel using the same - Google Patents

Abstract

A laminated body capable of providing a lid material having improved shape retention and impact resistance while maintaining seal strength and easy peelability required as a lid material, a lid material for a closed container using the same, and Provide a closed container. A laminate according to the present invention is a laminate in which a seal layer and a base layer are laminated via an adhesive layer, and the base layer has a glass transition point of 50 ° C to 150 ° C. It contains 40 to 95 parts by mass of an amorphous thermoplastic resin (A) and 5 to 60 parts by mass of an aromatic vinyl-conjugated diene block copolymer (B), wherein the amorphous thermoplastic resin (A) ) And the aromatic vinyl-conjugated diene block copolymer (B) are 100 parts by mass, and the aromatic vinyl-conjugated diene block copolymer (B) is a non-hydrogenated block copolymer, And at least one or both of a hydrogenated block copolymer. [Selection diagram] None

Description

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

  2. Description of the Related Art 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.

  For example, Patent Document 1 describes a cover material including a surface layer (base material layer), an intermediate layer, and a seal layer, which are layers made of polystyrene resin.

JP 2006-256256 (published September 28, 2006)

  However, there is room for improvement in the shape retention and impact resistance of the lid when forming the lid from the laminate.

  In view of the above problems, in the present invention, a laminate capable of providing a lid material with improved shape retention and impact resistance while maintaining the sealing strength and easy peelability necessary for the lid material, and the use thereof An object of the present invention is to provide a sealed container lid and a sealed container.

  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 is a laminate in which a seal layer and a base material layer are laminated via an adhesive layer, and the base material layer has an amorphous thermoplasticity with a glass transition point of 50 ° C to 150 ° C. 40 to 95 parts by mass of resin (A) and 5 to 60 parts by mass of aromatic vinyl-conjugated diene block copolymer (B), where amorphous thermoplastic resin (A) and aromatic vinyl -The total with the conjugated diene block copolymer (B) is 100 parts by mass, and the aromatic vinyl-conjugated diene block copolymer (B) is a non-hydrogenated block copolymer and a hydrogenated block Provided are a laminate that is at least one or both of copolymers, and a lid for a sealed container and a sealed container using the same.

  ADVANTAGE OF THE INVENTION According to this invention, the laminated body which can provide the lid | cover material with which shape retention property and impact resistance were improved, hold | maintaining the seal | sticker intensity | strength and easy peelability required as a lid | cover material, and an airtight container using the same A lid and a sealed container can be provided.

It is a figure explaining the test apparatus used in an impact resistance test.

<Laminated body>
The laminate according to the present invention has a base material layer, an adhesive layer, and a seal layer each containing a thermoplastic resin, and the base material layer and the seal layer are disposed via the adhesive layer. Specifically, it is a film-like laminate having flexibility. The thickness of this laminated body is 60 μm to 250 μm, preferably 80 μm to 240 μm, and 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. The base material layer preferably has shape retention from the viewpoint of avoiding bulking during display and imparting design properties.

  The base material layer includes the amorphous resin (A) and the aromatic vinyl-conjugated diene block copolymer (B), so that it has shape retention and impact resistance and is in close contact with the adhesive layer. It has sex. The shape of the laminate formed by the base material layer having shape retentivity is, for example, due to a part of the cover material protruding toward the outer periphery of the opening of the container in a state where the container is sealed. A so-called crown-like bent shape surrounding the periphery of the opening of the side surface of the container can be mentioned.

  The base material layer is formed from a resin composition containing a thermoplastic resin, and the thermoplastic resin has an amorphous thermoplastic resin (A) 40 to 50 ° C. to 150 ° C. 95 parts by mass, an aromatic vinyl-conjugated diene block copolymer and (B) 5 to 60 parts by mass are contained. However, the total of the amorphous thermoplastic resin (A) and the aromatic vinyl-conjugated diene block copolymer (B) is 100 parts by mass.

  The resin composition that forms the base material layer contains the amorphous thermoplastic resin (A) in the above ratio, thereby improving the rigidity of the lid material and expressing the shape retention of the lid material. Is possible.

  Moreover, the resin composition which forms a base material layer contains the said aromatic vinyl-conjugated diene block copolymer (B) in the said ratio, The interlayer adhesive strength of the said adhesive layer adjacent to the said base material layer As a result, the impact resistance can be improved, and when applied to a lid material, opening by delamination between the seal layer and the adhesive layer can be ensured and stable easy peelability can be exhibited.

(Amorphous thermoplastic resin (A))
The content of the amorphous thermoplastic resin (A) in the resin composition forming the base material layer is such that the amorphous thermoplastic resin (A) and the aromatic vinyl-conjugated diene block copolymer (B). When the total is 100 parts by mass, it is 40 parts by mass to 95 parts by mass, preferably 55 parts by mass to 90 parts by mass, more preferably 63 parts by mass to 85 parts by mass, and 68 parts by mass to More preferably, it is 80 parts by mass.

  The content of the aromatic vinyl-conjugated diene block copolymer (B) in the resin composition forming the base material layer is such that the amorphous thermoplastic resin (A) and the aromatic vinyl-conjugated diene block copolymer ( B) When the total of 100 parts by mass is 5 parts by mass to 60 parts by mass, preferably 10 parts by mass to 45 parts by mass, more preferably 15 parts by mass to 37 parts by mass, More preferably, it is 20 mass parts-32 mass parts.

  In the resin composition, if the amount of the aromatic vinyl-conjugated diene block copolymer and / or the hydrogenated product (B) thereof is too large, the shape retention of the lid is impaired, which is not preferable. On the other hand, if the blending amount of the aromatic vinyl-conjugated diene block copolymer (B) is too small, the impact resistance is lowered, and there is a possibility that sufficient strength as a lid material cannot be secured. Further, unintended delamination can occur between adjacent adhesive layers, which is not preferable.

  From the viewpoint of shape retention, the glass transition point of the amorphous thermoplastic resin (A) is 50 ° C to 150 ° C, preferably 60 ° C to 140 ° C, and preferably 70 ° C to 120 ° C. More preferred.

  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, terephthalic 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 viewpoint of extrusion processability and shape retention of the lid. From the viewpoint of recyclability, when the sealed 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).

(Aromatic vinyl-conjugated diene block copolymer (B))
The aromatic vinyl-conjugated diene block copolymer (B) used for the base material layer is a structural unit block [X] derived from aromatic vinyl and a structural unit block [Y] derived from conjugated diene. Is a block copolymer.

  The block structure of the block copolymer is not particularly limited, and [X]-[Y], [X]-[Y]-[X], [Y]-[X]-[Y], [X]- [Y]-[X]-[Y], [Y]-[X]-[Y]-[X], [X]-[Y]-[X]-[Y]-[X], [Y ]-[X]-[Y]-[X]-[Y].

  As aromatic vinyl, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, tert-butylstyrene, divinylbenzene, N, N-dimethyl-p-aminoethylstyrene, 2,4-dimethylstyrene, N, N-diethyl-p-aminoethyl styrene, vinyl naphthalene, vinyl anthracene and the like can be mentioned, and styrene can be preferably used. These aromatic vinyls can be used alone or in combination of two or more.

  Conjugated dienes include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 4,5 -Dimethyl- 1, 3- octadiene, chloroprene, etc. are mentioned, These can be used individually or in combination of 2 or more types.

  Aromatic vinyl-conjugated diene block copolymers can be broadly classified into block copolymers that are not hydrogenated and block copolymers that are hydrogenated. Hereinafter, in the present specification, the non-hydrogenated block copolymer means a non-hydrogenated block copolymer among aromatic vinyl-conjugated diene block copolymers unless otherwise specified. . In the present specification, the hydrogenated block copolymer means a hydrogenated product of an aromatic vinyl-conjugated diene block copolymer unless otherwise specified. In this specification, the aromatic vinyl-conjugated diene block copolymer (B) is both a non-hydrogenated block copolymer and a hydrogenated block copolymer unless otherwise specified. The meaning of

  The aromatic vinyl-conjugated diene block copolymer which is a non-hydrogenated block copolymer includes styrene-butadiene block copolymer (SB), styrene-isoprene block copolymer (SI), and styrene-butadiene-styrene. Examples thereof include a block copolymer (SBS) and a styrene-isoprene-styrene block copolymer (SIS), and more preferably a styrene-butadiene-styrene block copolymer (SBS), a styrene-isoprene-styrene block. A copolymer (SIS) etc. are mentioned.

  Examples of the aromatic vinyl-conjugated diene block copolymer that is a hydrogenated block copolymer include styrene- (ethylene-co-butylene) -styrene block copolymer (SEBS), styrene- (ethylene-co-). Propylene) block copolymer (SEP), styrene- (ethylene-co-propylene) -styrene block copolymer (SEPS), styrene- (ethylene-co-butylene) -styrene block copolymer (SEBS), etc. More preferably, a styrene- (ethylene-co-propylene) -styrene block copolymer (SEPS), a styrene- (ethylene-co-butylene) -styrene block copolymer (SEBS), and the like can be given.

  Aromatic vinyl-conjugated diene block copolymers (B) such as a non-hydrogenated block copolymer and a hydrogenated block copolymer can be used alone or in combination of two or more.

  In one embodiment of the present invention, the aromatic vinyl-conjugated diene block copolymer (B) preferably contains 34% by mass to 70% by mass of a block of a structural unit derived from aromatic vinyl, and 38% by mass to It is more preferable to contain 68% by mass. By including the block of the structural unit derived from the aromatic vinyl within this range, the impact resistance of the base material layer is more reliably improved while maintaining compatibility with the amorphous thermoplastic resin (A). Can do.

  The aromatic vinyl-conjugated diene block copolymer (B) has at least one functional group selected from an acid anhydride group, a carboxyl group, a hydroxyl group, an amino group, an isocyanate group, and an epoxy group. It may be a functional group-modified type aromatic vinyl-conjugated diene block copolymer provided at the terminal or a hydrogenated product thereof. Further, it may be a mixture of a modified copolymer and an unmodified copolymer.

  In a preferred embodiment of the present invention, the substrate layer may be a single layer structure formed from one resin composition, or may be a multilayer structure in which two or more layers having different compositions are laminated.

  For example, when the base material layer has a single layer structure, any one of a non-hydrogenated block copolymer and a hydrogenated block copolymer is used as the aromatic vinyl-conjugated diene block copolymer (B). It is sufficient that it is contained, and it is more preferred that both a non-hydrogenated block copolymer and a hydrogenated block copolymer are contained. For example, since the base material layer contains both a non-hydrogenated block copolymer and a hydrogenated block copolymer, both functions or functions of adhesion to the adhesive layer and impact resistance are achieved. Can be obtained in a well-balanced manner.

  In addition, when a base material layer is a multilayer structure, the total of the amorphous thermoplastic resin (A) contained in each base material layer, and the aromatic vinyl-conjugated diene block copolymer contained in each base material layer The total amount of the amorphous thermoplastic resin (A) contained in each base material layer may be 40 to 95 parts by mass with the total of (B) as 100 parts by mass. Similarly, regarding the content of the aromatic vinyl-conjugated diene block copolymer (B), the total of the amorphous thermoplastic resin (A) contained in the entire base material layer and the aromatic contained in each base material layer 100 parts by mass of the vinyl-conjugated diene block copolymer (B), the total amount of the aromatic vinyl-conjugated diene block copolymer (B) contained in each base material layer contained in each base material layer, What is necessary is just 5-60 mass parts.

  In one embodiment, the base material layer may have a two-layer configuration including a first base material layer located on the adhesive layer side and a second base material layer located on the surface layer side.

  In such a two-layer configuration, the first base material layer located on the adhesive layer side is higher in concentration than the second base material layer located on the surface layer side, and the aromatic vinyl-conjugated diene block copolymer weight It is preferable that a combination (B) is included. In other words, the second base material layer located on the surface layer side preferably contains the aromatic vinyl-conjugated diene block copolymer (B) at a lower concentration than the first base material layer.

  When the first base material layer contains the aromatic vinyl-conjugated diene block copolymer (B) at a higher concentration, the interlayer adhesive strength with the adjacent adhesive layer is increased and the impact resistance is further improved. Can be made. Further, the shape retention can be further improved by including the aromatic vinyl-conjugated diene block copolymer (B) at a lower concentration in the second base material layer.

  The content of the amorphous thermoplastic resin (A) in the resin composition forming the first base material layer is the same as that of the amorphous thermoplastic resin (A) and aromatic vinyl contained in the first base material layer. -The total of the conjugated diene block copolymer (B) is 100 parts by mass, preferably 25 parts by mass to 70 parts by mass, more preferably 30 parts by mass to 67 parts by mass, and 35 parts by mass to 64 parts by mass. More preferably, it is part by mass.

  The content of the aromatic vinyl-conjugated diene block copolymer (B) in the resin composition forming the first base layer is such that the amorphous thermoplastic resin (A) and the aromatic vinyl-conjugated diene block copolymer are The total amount of the polymer (B) is 100 parts by mass, preferably 30 parts by mass to 75 parts by mass, more preferably 33 parts by mass to 70 parts by mass, and 36 parts by mass to 65 parts by mass. Is more preferable.

  The content of the amorphous thermoplastic resin (A) in the resin composition forming the second base material layer is such that the amorphous thermoplastic resin (A) and aromatic vinyl contained in the second base material layer -The total of the conjugated diene block copolymer (B) is 100 parts by mass, preferably 78 parts by mass to 97 parts by mass, more preferably 80% by mass to 95 parts by mass, and 82 parts by mass to 93 parts by mass. More preferably, it is part by mass.

  The content of the aromatic vinyl-conjugated diene block copolymer (B) in the resin composition forming the second base material layer is such that the amorphous thermoplastic resin (A) contained in the second base material layer And the aromatic vinyl-conjugated diene block copolymer (B) as 100 parts by mass, preferably 3 to 22 parts by mass, more preferably 5 to 20 parts by mass, More preferably, it is 18 parts by mass.

  However, the total amount of the amorphous thermoplastic resin (A) contained in the first base material layer and the second base material layer is equal to the amorphous content contained in the first base material layer and the second base material layer. When the total amount of the thermoplastic resin (A) and the aromatic vinyl-conjugated diene block copolymer (B) is 100 parts by mass, it is 40 parts by mass to 95 parts by mass. In addition, the total amount of the aromatic vinyl-conjugated diene block copolymer (B) contained in the first base material layer and the second base material layer is determined based on the amorphous thermoplastic resin ( When the total amount of A) and the aromatic vinyl-conjugated diene block copolymer (B) is 100 parts by mass, it is 5 parts by mass to 60 parts by mass.

  In one embodiment of the present invention, the base material layer has two layers, and the first base material layer adjacent to the adhesive layer has a hydrogenated aromatic vinyl-conjugated diene block copolymer, that is, a hydrogenated block copolymer. It is preferable that the 2nd base material layer which contains a polymer and is located in the surface layer side contains the aromatic vinyl-conjugated diene block copolymer which is not a hydrogenation type, ie, a non-hydrogenation type block copolymer. With this configuration, impact resistance and shape retention can be further enhanced.

  In one embodiment of the present invention, the base material layer has two layers, and the first base material layer adjacent to the adhesive layer is a non-hydrogenated aromatic vinyl-conjugated diene block copolymer, and a hydrogenated product thereof. It is preferable to include both. With this configuration, the impact resistance can be further improved.

  In the aspect in which the first base material layer contains a hydrogenated aromatic vinyl-conjugated diene block copolymer, the aromatic vinyl-conjugated diene block copolymer contained in the resin composition forming the first base material layer is used. The content of the hydrogenated product of the polymer is preferably 25 to 65% by mass, and 30 to 55% by mass with respect to the total amount of the thermoplastic resin contained in the first base material layer. Is more preferable, and it is further more preferable that it is 35 mass%-45 mass%.

  The ratio of the thicknesses of the first and second base material layers is not particularly limited, but the thickness of the first base material layer / the second base material layer is from the viewpoint of balance between the shape retention and the strength of the laminate. The ratio is preferably 0.2 to 0.7.

(Other thermoplastic resins)
In the resin composition for forming the base material layer, the amorphous thermoplastic resin (A) and the aromatic vinyl-conjugated diene block copolymer and / or hydrogenation thereof are within the range not impairing the effects of the invention. In addition to the product (B), other thermoplastic resins such as a polyamide resin, a polyester resin, a polycarbonate resin, a polyolefin resin, an ionomer resin, and a biodegradable resin may be contained. Such other thermoplastic resins are used in an amount of 0 to 100 parts by mass with respect to a total of 100 parts by mass of the amorphous thermoplastic resin (A) and the aromatic vinyl-conjugated diene block copolymer (B). It can mix | blend within the range.

  Here, examples of the polyamide-based resin include 6 nylon, 66 nylon, 6-66 nylon, polymetaxylylene adipamide, polymetaxylylene pimeramide, polymetaxylylene azelamide, polyparaxylylene azelamide, polyparaxylylene. Lendecanamide, 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-VAGMA), ethylene- Maleic anhydride copolymer (E-MAH), ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH), propylene homopolymer, copolymers of propylene and other α-olefins, etc. Polyolefin resin, ethylene and norbornenes and tetracyclodode Cyclic olefins such as random copolymers with cyclic olefins, 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 resin composition forming the base layer is at least one additive selected from additives such as a lubricant, an antistatic agent, an antioxidant, a heat stabilizer, an ultraviolet absorber, an antibacterial agent, and an antifogging agent. May be contained. In addition, if it is content in the range which does not impair the effect of this invention, content of the additive contained in the resin composition which forms a base material layer is not limited.

  The thickness of the base material layer is preferably 30 μm to 200 μm, more preferably 40 μm to 180 μm, and further 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.

  In the present specification, the thickness of each layer can be measured by the following method. The thickness of each layer can be measured by cutting the laminate with a sharp razor and observing the obtained cross section with an electron microscope or an optical microscope. The thickness of the entire laminate is obtained by summing the thicknesses of all layers included in the laminate. Further, the thickness of each layer may be measured at a plurality of locations, and may be obtained as an average value of the thicknesses measured at each location.

<Adhesive layer>
The adhesive layer in the present invention is a layer that is located between the base material layer and the sealing layer and adheres them. 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, examples of the styrene elastomer include the above-mentioned aromatic vinyl-conjugated diene block copolymer, and styrene-butadiene-styrene block copolymer, styrene- (ethylene-co-propylene) -styrene block copolymer. Examples thereof include a polymer and a styrene- (ethylene-co-butadiene) -styrene copolymer. 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. It is preferable that content of the structural unit derived from ethylene in the ethylene-unsaturated carboxylic acid ester copolymer is 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 forming the adhesive layer contains at least one additive selected from additives such as a lubricant, an antistatic agent, an antioxidant, a heat stabilizer, an ultraviolet absorber, an antibacterial agent, and an antifogging agent. It may be. In addition, content of the additive contained in the resin composition which forms an contact bonding layer will not be limited if it is content in the range which does not impair the effect of this invention.

  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 seal layer in the present invention refers to a layer that comes into contact with the sealed container body when a lid member is formed from the laminate, and that seals (seals) the opening of the container.

  The seal layer is formed of a resin composition containing a thermoplastic resin, and the thermoplastic resin can be appropriately selected according to the material forming the sealed container body. For example, when the sealed container body is made of an amorphous thermoplastic resin, the seal layer is preferably formed of a resin composition containing a similar amorphous thermoplastic resin.

  In a preferred embodiment of the present invention, the resin composition forming the seal layer preferably contains an amorphous thermoplastic resin (C) having a glass transition point of 50 ° C to 120 ° C.

  Examples of the amorphous thermoplastic resin (C) include styrene resins and ester resins as in the case of the amorphous thermoplastic resin (A) used for the base material layer. These can be used alone or in combination of two or more. From the viewpoint of recyclability, it is preferable to use the same amorphous thermoplastic resin as the amorphous thermoplastic resin (A). 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 styrene resin is used for the sealed container body, it is more preferable to use impact-resistant polystyrene as the amorphous thermoplastic resin (C).

  The resin composition forming the sealing layer is at least one additive selected from 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. An agent may be contained. In addition, content of the additive contained in the resin composition which forms a seal layer will not be limited if it is content in the range which does not impair the effect of this invention.

  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, c / (a + b + c) is preferably 0.5 to 0.92 with respect to the thickness a of the sealing layer, the thickness b of the adhesive layer, and the thickness c of the base material layer. More preferably, it is 0.65-0.91, More preferably, it is 0.78-0.89. By setting the ratio of the thickness a of the sealing layer, the thickness b of the adhesive layer, and the thickness c of the base material layer to such a range, a lid material having more suitable shape retention can be obtained. In addition, when the laminated body is provided with the several base material layer, the thickness of the base material layer c is the sum total of the thickness of each base material layer.

  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. The lid material is obtained by, for example, drawing a laminated body into a circular shape 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. A container lid. 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.

[Calculation method of content of each resin contained in base material layer]
When the base material layer has the first base material layer and the second base material layer, the content of the amorphous thermoplastic resin (A) contained in the base material layer, and non-hydrogenation The content of the type block copolymer (B) and the content of the hydrogenated type block copolymer (B) were calculated by the formulas (1) to (3) as follows.

Y _A : The total Y _A of the contents of the amorphous thermoplastic resin (A) contained in each base material layer was calculated from the following formula (1).
Y _A = (Y _A1 X ₁ + Y _A2 X ₂ ) / (X ₁ + X ₂ )
= (Y _A1 + X′Y _A2 ) / (1 + X ′) (1)
Y _A1 : Content (% by mass) of the amorphous thermoplastic resin (A) in the first base material layer
Y _A2 : content (% by mass) of amorphous thermoplastic resin (A) in the second base material layer
X ₁ : mass per unit area of the first base material layer X ₂ : mass per unit area of the second base material layer X ′: per unit area of the first base material layer and the second base material layer Mass ratio

X ′ was calculated from the following (1 ′).
X ′ = X ₂ / X ₁ = (T ₂ ρ ₂ ) / (T ₁ ρ ₁ ) (1 ′)
T ₁ : thickness of first base material layer T ₂ : thickness of _second base material layer ρ ₁ : density of first base material layer (density of resin composition forming first base material layer)
ρ ₂ : density of the second base material layer (density of the resin composition forming the second base material layer)

ρ ₁ and ρ ₂ were calculated from the following formulas (1 ″) and (1 ′ ″), respectively.
ρ ₁ = Y _A1 ρ _A + Y _B1 ρ _B + Y _B′1 ρ _{B ′} (1 ″)
ρ ₂ = Y _{A 2} ρ _A + Y _{B 2} ρ _B + Y _{B ′ 2} ρ _{B ′} (1 ′ ″)
Y _A1 : Same as formula (1) Y _A2 : Same as formula (1) Y _B1 : Content (% by mass) of non-hydrogenated block copolymer (B) in the first base material layer Y _B′1 : Content (mass%) of hydrogenated block copolymer (B) in the first base material layer Y _B2 : Content of non-hydrogenated block copolymer (B) in the second base material layer ( % By mass) Y _B′2 : content (% by mass) of hydrogenated block copolymer (B) in the second substrate layer ρ _A : density of amorphous thermoplastic resin (A) ρ _B : non Density ρ _{B ′ of} hydrogenated block copolymer (B): Density of hydrogenated block copolymer (B) When the prescriptions of the first base material layer and the second base material layer are close to each other Assuming that ρ ₁ and ρ ₂ are simply equal, the content of each component can be obtained.

Y _B : The total content Y _B of the non-hydrogenated block copolymer (B) in each base material layer was calculated from the following formula (2).
Y _B = (Y _B1 + X′Y _B2 ) / (1 + X ′) (2)
X ′: Same as formula (1 ′) Y _B1 : Same as formula (1 ″) Y _B2 : Same as formula (1 ′ ″)

Y _{B ′} : Total content of hydrogenated block copolymer (B) in each base material layer
Y _{B ′} was calculated from the following equation (3).
_{Y B '= (Y B'1 +} X'Y B'2) / (1 + X') ... (3)
X ′: Same as formula (1 ′) Y _B′1 : Same as formula (1 ″) Y _B′2 : Same as formula (1 ′ ″)

The glass transition point of the amorphous thermoplastic resin was measured under the following conditions using a differential scanning calorimeter DSC250 manufactured by TA Instruments, and the midpoint glass transition temperature was taken as the glass transition point. .
Temperature rise 20-200 ° C. (10 ° C./min) 5 minutes hold cooling 200-0 ° C. (10 ° C./min) 5 minutes hold measurement 0-200 ° C. (10 ° C./min)

[Example 1]
<Sealing layer>
As a resin composition for forming a sealing layer, impact-resistant polystyrene (HIPS, Toyostyrene HI H650, glass transition point = 102.7 ° C., manufactured by Toyo Styrene Co., Ltd.) 20% by mass, polystyrene (GPPS, Toyo Styrene Co., Ltd.) Manufactured Toyo Styrol GP G210C, glass transition point = 100.5 ° C., pellet blend of 80% by mass (thermoplastic resin (C)) was used.

<Adhesive layer>
Ethylene / methyl acrylate copolymer (manufactured by Sumitomo Chemical Co., Ltd., trade name ACRIFT (registered trademark): CG4002, content of 31% by mass of structural unit derived from methyl acrylate, melt flow rate (190 ° C., 2.16 kgf) = 5 g / 10 min) 22.2% by mass, linear low density polyethylene (manufactured by Sumitomo Chemical Co., Ltd., trade name Sumikasen (registered trademark) E: FV202, melt flow rate (190 ° C., 2.16 kgf)) = 1.9 g / 10 minutes) 15.45% by mass, styrene- (ethylene-co-propylene) -styrene block copolymer (Kuraray Co., Ltd. Septon (registered trademark) 2104) 7.3% by mass, high-impact polystyrene (Toyo 54.9% by mass of Toyostyrene HI H650 manufactured by Styrene Co., Ltd. and an antioxidant (Sumitomo Chemical Co., Ltd. ) GP) 0.15 wt%, melt mixed using a biaxial extruder to prepare pellets.

  42% by mass of the pellets obtained above, ethylene / methyl acrylate copolymer (trade name ACRIFT (registered trademark): CG4002 manufactured by Sumitomo Chemical Co., Ltd.) 45% by mass, linear low density polyethylene (Sumitomo Chemical Co., Ltd.) Manufactured by Sumikasen (registered trademark) E: FV401, melt flow rate (190 ° C., 2.16 kgf) = 4 g / 10 min) 11% by mass, and antioxidant master batch (manufactured by Sumitomo Chemical Co., Ltd., CMB-735) What pellet-blended 2 mass% was used as a resin composition which forms an adhesive layer.

<Base material layer>
The base material layer has a two-layer configuration including a first base material layer adjacent to the adhesive layer and a second base material layer located on the surface layer side.

As a resin composition for forming the first base material layer, impact-resistant polystyrene (HIPS, manufactured by PS Japan Co., Ltd., HT478, glass transition point = 103.6 ° C., density 1.04 g / cm ³ (23 ° C.)) 60% by mass, hydrogenated styrene-based thermoplastic elastomer (SEBS, manufactured by Asahi Kasei Co., Ltd. Tuftec (registered trademark) H1043 styrene / butadiene / butylene mass ratio: 67/33, density 0.97 g / cm ³ (23 ° C.)) A pellet blend of 40% by mass was used.

As a resin composition for forming the second substrate layer, 90% by mass of impact-resistant polystyrene (HIPS, HT478 manufactured by PS Japan Co., Ltd.) and styrene / butadiene thermoplastic elastomer (SBS, manufactured by Asahi Kasei Co., Ltd.) (Registered Trademark) 126S Styrene / butadiene / butylene ratio: 40/60, density 0.95 g / cm ³ (23 ° C.) 10% by mass and a pellet blend were used.

  When the total amount of the thermoplastic resin contained in the entire base material layer is 100% by mass, the total amount of HIPS contained in the first and second base material layers is 83.6% by mass, and the total amount of SBS Was 7.8% by mass, and the total amount of SEBS was 8.6% by mass.

  Using the above materials, 5 types 5 layers co-extrusion T die cast processing machine (extruder A: 30 mmΦ, extruder B: 30 mmΦ, extruder C: 40 mmΦ, extruder D: 45 mmΦ, extruder E: 45 mmΦ, layer configuration = Extruder A / Extruder B / Extruder C / Extruder D / Extruder E), Extruder A is a resin composition for a seal layer, Extruder B is a resin composition for an adhesive layer, Extruder C The first base layer resin composition, the extruder D and the extruder E are charged with the second base layer resin composition, the seal layer, the adhesive layer, the first base layer and the first base layer. A laminate in which two base material layers were laminated in this order was manufactured. The processing temperatures at this time are Extruder A: 220 ° C., Extruder B: 180 ° C., Extruder C: 220 ° C., Extruder D: 220 ° C., Extruder E: 220 ° C., and the die temperature is 240 ° C. Met.

  Regarding the thickness of the obtained laminate, the sealing layer was 8 μm, the adhesive layer was 14 μm, the first base material layer was 30 μm, and the second base material layer was 108 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]
<Sealing layer>
As the resin composition for forming the seal layer, impact-resistant polystyrene (HIPS, Toyostyrene HI H650 manufactured by Toyo Styrene Co., Ltd.) was used.

<Adhesive layer>
The resin composition used in Example 1 was used as the resin composition for forming the adhesive layer.

<Base material layer>
The base material layer has a two-layer configuration including a first base material layer adjacent to the adhesive layer and a second base material layer located on the surface layer side.

As a resin composition for forming the first substrate layer, impact-resistant polystyrene (HIPS, HT478 manufactured by PS Japan Co., Ltd.) 50% by mass, hydrogenated styrene thermoplastic elastomer (SEBS, manufactured by Asahi Kasei Co., Ltd. Tuftec ( (Registered trademark) H1043 styrene / butadiene / butylene mass ratio: 67/33) 40% by mass, and styrene / butadiene thermoplastic elastomer (SBS, manufactured by Asahi Kasei Co., Ltd., Tufprene (registered trademark) A styrene / butadiene mass ratio: 40 / 60, density 0.95 g / cm ³ (23 ° C.)) 10% by mass pellet-blended was used.

  As the resin composition for forming the second base material layer, 85% by mass of impact-resistant polystyrene (HIPS, HT478 manufactured by PS Japan Co., Ltd.) and styrene / butadiene-based thermoplastic elastomer (SBS, manufactured by Asahi Kasei Co., Ltd.) (Registered Trademark) A Styrene / butadiene / butylene ratio: 40/60) 15% by mass and a pellet blend were used.

  When the total amount of the thermoplastic resin contained in the entire base material layer is 100% by mass, the total amount of HIPS contained in the first and second base material layers is 71.4% by mass, and the total amount of SBS Was 13.0% by mass, and the total amount of SEBS was 15.6% by mass.

  Using the above materials, a laminate in which a seal layer, an adhesive layer, a first base material layer, and a second base material layer were laminated in this order was produced in the same manner as in Example 1.

  The thickness of the obtained laminate was 7 μm for the sealing layer, 14 μm for the adhesive layer, 55 μm for the first base material layer, and 84 μm for the second base material layer.

  Using the obtained laminate, a lid was produced in the same manner as in Example 1.

[Example 3]
<Sealing layer>
The resin composition used in Example 2 was used as the resin composition for forming the seal layer.

<Adhesive layer>
The resin composition used in Example 1 was used as the resin composition for forming the adhesive layer.

<Base material layer>
The base material layer has a two-layer configuration including a first base material layer adjacent to the adhesive layer and a second base material layer located on the surface layer side.

  As a resin composition for forming the first substrate layer, impact-resistant polystyrene (HIPS, HT478 manufactured by PS Japan Co., Ltd.) 40% by mass, hydrogenated styrene thermoplastic elastomer (SEBS, manufactured by Asahi Kasei Co., Ltd. Tuftec ( (Registered trademark) H1043 Styrene / butadiene / butylene mass ratio: 67/33) 40% by mass, and styrene / butadiene-based thermoplastic elastomer (SBS, manufactured by Asahi Kasei Co., Ltd.) Tufprene (registered trademark) A styrene / butadiene mass ratio: 40 / 60) A pellet blend of 20% by mass was used.

  The resin composition used for the second substrate layer of Example 2 was used as the resin composition for forming the second substrate layer.

  When the total amount of the thermoplastic resin contained in the entire base material layer is 100% by mass, the total amount of HIPS contained in the first and second base material layers is 67.5% by mass, and the total amount of SBS Was 17.0% by mass, and the total amount of SEBS was 15.5% by mass.

  Using the above materials, a laminate in which a seal layer, an adhesive layer, a first base material layer, and a second base material layer were laminated in this order was produced in the same manner as in Example 1. The thickness of each layer of the obtained laminate was the same as in Example 2. Using the obtained laminate, a lid was produced in the same manner as in Example 1.

[Example 4]
<Sealing layer>
The resin composition used in Example 1 was used as the resin composition for forming the seal layer.

<Adhesive layer>
The resin composition used in Example 1 was used as the resin composition for forming the adhesive layer.

<Base material layer>
The base material layer has a two-layer configuration including a first base material layer adjacent to the adhesive layer and a second base material layer located on the surface layer side.

  As the resin composition forming the first base material layer, the resin composition used for the first base material layer of Example 3 was used.

  The resin composition used for the second substrate layer of Example 1 was used as the resin composition for forming the second substrate layer.

  When the total amount of the thermoplastic resin contained in the entire base material layer is 100% by mass, the total amount of HIPS contained in the first and second base material layers is 70.6% by mass, and the total amount of SBS Was 13.9% by mass, and the total amount of SEBS was 15.5% by mass.

  Using the above materials, a laminate in which a seal layer, an adhesive layer, a first base material layer, and a second base material layer were laminated in this order was produced in the same manner as in Example 1. The thickness of each layer of the obtained laminate was the same as in Example 2. Using the obtained laminate, a lid was produced in the same manner as in Example 1.

[Example 5]
<Sealing layer>
The resin composition used in Example 1 was used as the resin composition for forming the seal layer.

<Adhesive layer>
The resin composition used in Example 1 was used as the resin composition for forming the adhesive layer.

<Base material layer>
The base material layer has a two-layer configuration including a first base material layer adjacent to the adhesive layer and a second base material layer located on the surface layer side.

  As the resin composition forming the first base material layer, the resin composition used for the first base material layer of Example 3 was used.

  The resin composition used for the second substrate layer of Example 1 was used as the resin composition for forming the second substrate layer.

  When the total amount of the thermoplastic resin contained in the entire base material layer is 100% by mass, the total amount of HIPS contained in the first and second base material layers is 70.6% by mass, and the total amount of SBS Was 13.9% by mass, and the total amount of SEBS was 15.5% by mass.

  Using the above materials, a laminate in which a seal layer, an adhesive layer, a first base material layer, and a second base material layer were laminated in this order was produced in the same manner as in Example 1. The thickness of the obtained laminate was 5.3 μm for the sealing layer, 10.5 μm for the adhesive layer, 41.2 μm for the first base material layer, and 63 μm for the second base material layer. It was. Using the obtained laminate, a lid was produced in the same manner as in Example 1.

[Example 6]
<Sealing layer>
The resin composition used in Example 2 was used as the resin composition for forming the seal layer.

<Adhesive layer>
The resin composition used in Example 1 was used as the resin composition for forming the adhesive layer.

<Base material layer>
The base material layer has a two-layer configuration including a first base material layer adjacent to the adhesive layer and a second base material layer located on the surface layer side.

  As the resin composition forming the first base material layer, the resin composition used for the first base material layer of Example 3 was used.

  The resin composition used for the second substrate layer of Example 1 was used as the resin composition for forming the second substrate layer.

  When the total amount of the thermoplastic resin contained in the entire base material layer is 100% by mass, the total amount of HIPS contained in the first and second base material layers is 73.7% by mass, and the total amount of SBS Was 13.3% by mass, and the total amount of SEBS was 13.0% by mass.

  Using the above materials, a laminate in which a seal layer, an adhesive layer, a first base material layer, and a second base material layer were laminated in this order was produced in the same manner as in Example 1. The thickness of the obtained laminate was 7 μm for the sealing layer, 14 μm for the adhesive layer, 33 μm for the first base material layer, and 66 μm for the second base material layer. Using the obtained laminate, a lid was produced in the same manner as in Example 1.

[Example 7]
<Sealing layer>
The resin composition used in Example 1 was used as the resin composition for forming the seal layer.

<Adhesive layer>
The resin composition used in Example 1 was used as the resin composition for forming the adhesive layer.

<Base material layer>
The base material layer has a two-layer configuration including a first base material layer adjacent to the adhesive layer and a second base material layer located on the surface layer side.

  As the resin composition forming the first base material layer, the resin composition used for the first base material layer of Example 3 was used.

  The resin composition used for the second substrate layer of Example 1 was used as the resin composition for forming the second substrate layer.

  When the total amount of the thermoplastic resin contained in the entire base material layer is 100% by mass, the total amount of HIPS contained in the first and second base material layers is 70.6% by mass, and the total amount of SBS Was 13.9% by mass, and the total amount of SEBS was 15.5% by mass.

  Using the above materials, a laminate in which a seal layer, an adhesive layer, a first base material layer, and a second base material layer were laminated in this order was produced in the same manner as in Example 1. The thickness of the obtained laminate was 3.5 μm for the sealing layer, 7 μm for the adhesive layer, 27.5 μm for the first base material layer, and 42 μm for the second base material layer. Using the obtained laminate, a lid was produced in the same manner as in Example 1.

[Example 8]
<Sealing layer>
The resin composition used in Example 2 was used as the resin composition for forming the seal layer.

<Adhesive layer>
The resin composition used in Example 1 was used as the resin composition for forming the adhesive layer.

<Base material layer>
The base material layer has a two-layer configuration including a first base material layer adjacent to the adhesive layer and a second base material layer located on the surface layer side.

  As the resin composition forming the first base material layer, the resin composition used for the first base material layer of Example 3 was used.

  The resin composition used for the second substrate layer of Example 1 was used as the resin composition for forming the second substrate layer.

  When the total amount of the thermoplastic resin contained in the entire base material layer is 100% by mass, the total amount of HIPS contained in the first and second base material layers is 73.7% by mass, and the total amount of SBS Was 13.3% by mass, and the total amount of SEBS was 13.0% by mass.

  Using the above materials, a laminate in which a seal layer, an adhesive layer, a first base material layer, and a second base material layer were laminated in this order was produced in the same manner as in Example 1. The thickness of the obtained laminate was 4.7 μm for the seal layer, 9.3 μm for the adhesive layer, 22 μm for the first base material layer, and 44 μm for the second base material layer. Using the obtained laminate, a lid was produced in the same manner as in Example 1.

[Comparative Example 1]
<Sealing layer>
The resin composition used in Example 2 was used as the resin composition for forming the seal layer.

<Adhesive layer>
The resin composition used in Example 1 was used as the resin composition for forming the adhesive layer.

<Base material layer>
As the resin composition for forming the base material layer, impact-resistant polystyrene (HIPS, HT478 manufactured by PS Japan Co., Ltd.) was used.

  In the same manner as in Example 1, using a five-kind five-layer coextrusion T die-casting machine, the extruder A is a resin composition for a seal layer, the extruder B is a resin composition for an adhesive layer, an extruder C, A resin composition for a base material layer was added to D and E to produce a laminate in which a seal layer, an adhesive layer, and a base material layer were laminated in this order. The processing temperatures at this time are Extruder A: 220 ° C., Extruder B: 180 ° C., Extruder C: 220 ° C., Extruder D: 220 ° C., Extruder E: 220 ° C., and the die temperature is 240 ° C. Met. As for the thickness of the obtained laminate, the sealing layer was 3.5 μm, the adhesive layer was 7 μm, and the base material layer was 69.5 μm. Using the obtained laminate, a lid was produced in the same manner as in Example 1.

[Comparative Example 2]
<Sealing layer>
The resin composition used in Example 2 was used as the resin composition for forming the seal layer.

<Adhesive layer>
The resin composition used in Example 1 was used as the resin composition for forming the adhesive layer.

<Base material layer>
The base material layer has a two-layer configuration including a first base material layer adjacent to the adhesive layer and a second base material layer located on the surface layer side.

  As a resin composition for forming the first base material layer, 20% by mass of impact-resistant polystyrene (HIPS, HT478 manufactured by PS Japan Co., Ltd.), hydrogenated styrene thermoplastic elastomer (SEBS, manufactured by Asahi Kasei Co., Ltd. Tuftec ( (Registered trademark) H1043 Styrene / butadiene / butylene mass ratio: 67/33) 40% by mass, and styrene / butadiene-based thermoplastic elastomer (SBS, manufactured by Asahi Kasei Co., Ltd.) Tufprene (registered trademark) A styrene / butadiene mass ratio: 40 / 60) A pellet blend of 40% by mass was used.

  The resin composition used for the second substrate layer of Example 1 was used as the resin composition for forming the second substrate layer.

  When the total amount of the thermoplastic resin contained in the entire base material layer is 100% by mass, the total amount of HIPS contained in the first and second base material layers is 37.8% by mass, and the total amount of SBS Was 32.4% by mass, and the total amount of SEBS was 29.8% by mass.

  In the same manner as in Example 1, using a five-kind five-layer coextrusion T die-casting machine, the extruder A is a resin composition for a seal layer, the extruder B is a resin composition for an adhesive layer, an extruder C, A resin composition for the first substrate layer is introduced into D, and a resin composition for the second substrate layer is introduced into the extruder E, and the seal layer, the adhesive layer, the first substrate layer, and the second substrate are introduced. A laminate in which layers were laminated in this order was manufactured. The processing temperatures at this time are Extruder A: 220 ° C., Extruder B: 180 ° C., Extruder C: 220 ° C., Extruder D: 220 ° C., Extruder E: 220 ° C., and the die temperature is 240 ° C. Met. The thickness of the obtained laminate was 7 μm for the sealing layer, 14 μm for the adhesive layer, 105 μm for the first base material layer, and 34 μm for the second base material layer. Using the obtained laminate, a lid was produced in the same manner as in Example 1.

[Comparative Example 3]
<Sealing layer>
The resin composition used in Example 2 was used as the resin composition for forming the seal layer.

<Adhesive layer>
The resin composition used in Example 1 was used as the resin composition for forming the adhesive layer.

<Base material layer>
As a resin composition for forming the base material layer, 97% by mass of impact-resistant polystyrene (HIPS, HT478 manufactured by PS Japan Co., Ltd.) and hydrogenated styrene-based thermoplastic elastomer (SEBS, manufactured by Asahi Kasei Co., Ltd. Tuftec (registered trademark) ) H1043 Styrene / butadiene / butylene mass ratio: 67/33) What was pellet blended with 3% by mass was used.

  When the total amount of the thermoplastic resin contained in the whole base material layer was 100% by mass, the total amount of HIPS contained in the base material layer was 97% by mass, and the total amount of SEBS was 3% by mass.

  In the same manner as in Example 1, using a five-kind five-layer coextrusion T die-casting machine, the extruder A is a resin composition for a seal layer, the extruder B is a resin composition for an adhesive layer, an extruder C, A resin composition for a base material layer was added to D and E to produce a laminate in which a seal layer, an adhesive layer, and a base material layer were laminated in this order. The processing temperatures at this time are Extruder A: 220 ° C., Extruder B: 180 ° C., Extruder C: 220 ° C., Extruder D: 220 ° C., Extruder E: 220 ° C., and the die temperature is 240 ° C. Met. Regarding the thickness of the obtained laminate, the seal layer was 7 μm, the adhesive layer was 14 μm, and the base material layer was 139 μm. Using the obtained laminate, a lid was produced in the same manner as in Example 1.

[Evaluation]
The laminates obtained in Examples 1 to 8 and Comparative Examples 1 to 3 were evaluated by the following methods. Table 1 shows the configuration of each laminate, and Table 2 shows the evaluation results.

<Easy peelability test>
As an adherend, an HIPS sheet (HT516 manufactured by PS Japan Co., Ltd.) having a thickness of 400 μm cut into 70 mm × 90 mm was used. This adherend and the sealing layers of the laminates obtained in the examples and comparative examples were brought into close contact with each other in a strip shape having a width of 10 mm at a pressure of 0.29 MPa, a time of 2 seconds, and a seal temperature of 180 ° C. Heat sealed (parallel to the 90 mm length direction). A strip test piece of 15 mm × 70 mm was produced by cutting out at 15 mm width intervals so as to include the seal portion perpendicular to the strip-shaped seal portion.

  Using a tensile tester manufactured by Shimadzu Corporation, Autograph AGS-5kNX, the peel strength when peeled 180 ° at a tensile rate of 300 mm / min in an atmosphere of 23 ° C. was measured. For easy peelability, if the peel strength is 5 N / 15 mm to 30 N / 15 mm width, it is judged that the balance between the sealing strength of the container and the lid material peel is excellent, and “◯”, and the outside of the peel strength range is “× "

<Shape retention test>
From the laminates obtained in the examples and comparative examples, square and horizontal 3 cm test pieces having diagonal lines in the machine direction (MD) and the direction perpendicular to the machine direction (TD) were cut. The test piece is bent 180 degrees using a line connecting the center point of one side of the test piece and one side parallel to it as a fold line, and a weight of 2 kg is placed on the bent part and held for 10 seconds. And the return angle 10 seconds after releasing the load was measured. An angle of less than 90 degrees at this time was rated as ◯ for excellent shape retention, and an angle of 90 degrees or more was marked as x.

<Impact resistance test>
The test apparatus shown in FIG. 1 was prepared and an impact resistance test was performed. Specifically, a container 1 made of resin (polystyrene) having an inner volume of 128 mL and having a circular opening with an inner diameter of 62 mm surrounded by a flange portion having a width of 3 mm was prepared. Moreover, the laminated body obtained by the Example and the comparative example was cut | judged to the square of 75 mm x 75 mm, and the test piece 2 was prepared. 80 mL of water is poured into the container 1, the test piece 2 is placed on the circular opening of the container 1, a PET film having a thickness of 12 μm is placed thereon, and heat sealed at a temperature of 180 ° C. and a load of 100 kgf for 1 second. After that, the PET film was peeled off, and the test piece protruding from the flange portion was cut off to prepare a sealed container sample.

  A cylinder 3 having a height of 910 mm, an inner diameter of 75 mm, and a thickness of 7.5 mm is prepared. To reduce air resistance, four spacers 4 having a thickness of 4 mm are provided at the lower end of the cylinder 3 at equal intervals, and the spacers 4 are formed of the cylinder 3 It stuck on the concrete board 5 so that it might become the arrangement | positioning which does not protrude inside. In FIG. 1, only two spacers 4 are shown, and the remaining two spacers are not shown. The above-mentioned cylinder 3 is arranged on the concrete plate 5, and the prepared sealed container sample with water is arranged in the upper opening of the cylinder 3 so that the test piece 2 is on the lower side, and falls on the concrete plate 5. This was repeated up to 5 times to obtain a single drop test. This drop test is carried out 5 times per sample, and the test piece 2 is broken or unsealed from 0 to 1 times, judged to be excellent in impact resistance, set to “◯”, and 2 to 5 times. Things were evaluated as “x”.

  As shown in Table 2, the sealed container using the laminates of Examples 1 to 8 maintained the sealed state without breaking the laminate in any of the five drop tests, and had excellent impact resistance. showed that. Moreover, the laminated body of Examples 1-8 had a small return angle in the shape retention test, and was excellent in shape retention. On the other hand, the sealed container using the laminated body of Comparative Example 1 is 4 times out of 5 drop tests, and the sealed container using the laminated body of Comparative Example 3 is 2 out of 5 drop tests. The laminated body was torn and the water inside leaked. Moreover, the laminated body of the comparative example 2 had a large return angle in the shape retention test, and was inferior in shape retention.

Claims (9)

A laminate in which a seal layer and a base material layer are laminated via an adhesive layer,
The base material layer has an amorphous thermoplastic resin (A) having a glass transition point of 50 ° C to 150 ° C of 40 to 95 parts by mass, and an aromatic vinyl-conjugated diene block copolymer (B) of 5 to 60 parts by mass. Here, the total of the amorphous thermoplastic resin (A) and the aromatic vinyl-conjugated diene block copolymer (B) is 100 parts by mass,
The said aromatic vinyl-conjugated diene block copolymer (B) is a laminated body which is at least one or both of a non-hydrogenation type block copolymer and a hydrogenation type block copolymer.   The thickness of the said base material layer is 30 micrometers-200 micrometers, and the laminated body of Claim 1 whose thickness of the said whole laminated body is 60 micrometers-250 micrometers.   The laminated body according to claim 1 or 2, wherein the amorphous thermoplastic resin (A) is a styrene resin.   The said sealing layer is a laminated body as described in any one of Claims 1-3 containing the amorphous thermoplastic resin (C) whose glass transition point is 50 to 150 degreeC.   The laminate according to claim 4, wherein the amorphous thermoplastic resin (C) is a styrene resin. The thickness of the sealing layer is a, the thickness of the adhesive layer is b, and the thickness of the base material layer is c,
The laminate according to any one of claims 1 to 5, wherein c / (a + b + c) is 0.5 to 0.92.   The laminate according to any one of claims 1 to 6, wherein the aromatic vinyl-conjugated diene block copolymer (B) contains 34 mass% to 70 mass% of a structural unit derived from aromatic vinyl.   The lid | cover material for sealed containers which consists of a laminated body as described in any one of Claims 1-7.   A sealed container comprising the sealed container lid according to claim 8 and a container body.

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