JP2015189481A - Package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a package which can promote the color development of meat by a thin film layer which is excellent in food sanitation and has a good easy-opening property and a high air permeability remaining in a bottom material. SOLUTION: A surface resin layer (A), an oxygen barrier resin layer (B), a pinhole-resistant resin layer (C), and a heat seal resin layer (D) are (A) / (B) / (C) / (D) is laminated in the order, and a multilayer film comprising a layer having a peel strength of 0.05 to 5.0 N / 15 mm width between the layer (B) and the layer (C) is used as a lid, and the layer of the multilayer film ( D) is a package in which the bottom material and the lid material are heat-sealed by heat-sealing to the seal part of the object to be sealed, and when the multilayer film is peeled off, the layer (C) and the layer (D) are A package comprising the delamination, the layer (A), the layer (B), and the layer (C) are removed, and the thin film layer of the layer (D) is left exposed on the sealed body. [Selection] Figure 1

Description

  The present invention relates to a package having a multilayer film as a lid, and more particularly to a package having a delamination property and a breathability particularly suitable for packaging raw meat such as beef, chicken and pork. is there.

  In Japan, meat that has been packaged under low oxygen conditions can prevent mold and bacteria, and the meat has a purple color despite its long shelf life. Tend to be disliked. Meat in which the myoglobin in the meat is combined with oxygen and becomes bright red looks fresh and appetizing, so many consumers tend to prefer this red meat.

  Generally, in retail stores such as supermarkets, many products are stretch-wrapped with wrap etc. on trays made of foamed styrene, polyvinyl chloride, polystyrene, polypropylene, etc. that do not have oxygen barrier properties at the backyard on the day before or on the day of sale. doing. However, in this packaging form, since it easily binds to oxygen, the color immediately changes to bright red immediately after packaging. However, since meat tends to rot, the shelf life must be shortened. In addition, the backyard packaging work takes time, and meat that has changed from bright red to black red always has the problem of food loss to be discarded.

On the other hand, in the United States and Europe, methods for maintaining the freshness of fresh meat and coloring technology that have solved the above-mentioned problems have been established, and various packaging bodies having a cover material film in which an impermeable film and a permeable film are laminated. Is used. For example, in Patent Documents 1 and 2, the meat is dismantled at a central processing facility, the packaged product is delivered in a low oxygen environment, the lid is peeled off at a retail store such as a supermarket, and the delaminated breathable film is exposed. Thus, a package is disclosed in which oxygen flows into the headspace of the product. This package is a product in which meat is placed on a tray and filled with inert gas, such as nitrogen or carbon dioxide, and the impervious film (barrier layer) blocks oxygen to prolong the shelf life of the product. it can. When products are displayed at supermarkets and other stores, the impermeable film on the surface is peeled off to expose the permeable film, so that oxygen quickly penetrates into the package and the consumer likes It turns red. The permeable film of this package is preferably provided with very fine holes (for example, less than 250 μm in diameter) in order to promote the color development of meat in a short time, approximately 50,000 cc / (m ⁽² · 24 h · atm) has a high oxygen permeability.

  There are laminating methods such as adhesives, extrusion lamination, and thermal lamination as methods for laminating these impermeable films and permeable films. These methods use heat and pressure, so the holes in the permeable film melt. Therefore, it is recommended that the surface of each film be corona-treated and pressed with a pair of nip rolls.

  Specifically, as an example of Patent Document 2, a biaxially stretched coextruded multilayer film is made to penetrate micropores by electrostatic discharge, and then a coextruded film formed by an inflation method and a silicon oxide layer on one side are formed. The packaging material which laminated | stacked the stretched polyethylene terephthalate which carried out vapor deposition coating is illustrated.

  However, in the packaging body having the above-described structure, a step of applying a corona treatment and a step of pressing with a nip roll occur before lamination, so that dust, dust, etc. floating in the atmosphere adhere to the sticky film surface. However, foreign matter may be mixed in, and special equipment such as corona treatment equipment and crimping equipment is also required, resulting in an increase in manufacturing cost.

Japanese Patent No. 3675833 Japanese Patent No. 4024868

  The present invention has been made in view of the above-mentioned problems, and its solution is excellent in food hygiene, promoting easy color development by good easy-openability and a thin air-permeable thin film layer remaining on the bottom. It is to provide a packaging body that can be used.

  As a result of intensive studies in view of the above problems, the present inventor used an amide resin having a specific resin, an ester resin, a polypropylene resin, and a cyclic polyolefin resin as a main component of the pinhole-resistant fat layer, It has been found that the above problem can be solved by arranging the pinhole resistant resin layer between the oxygen barrier resin layer and the heat seal resin layer, and the present invention has been completed.

  That is, the gist of the present invention is that the surface resin layer (A), the oxygen barrier resin layer (B), the pinhole resistant resin layer (C), and the heat seal resin layer (D) are (A) / (B) / It is laminated in the order of (C) / (D), and consists of a layer having a peel strength of 0.05 to 5.0 N / 15 mm width between the oxygen barrier resin layer (B) and the pinhole resistant resin layer (C). It is a package in which the bottom film and the cover material are heat-sealed by heat-sealing the heat-seal resin layer (D) of the multilayer film to the seal part of the object to be sealed. When peeling, the pinhole resistant resin layer (C) and the heat seal (D) are delaminated, and the surface resin layer (A), the oxygen barrier resin layer (B), and the pinhole resistant resin layer (C) Is removed, and the thin film layer of the heat seal resin layer (D) is exposed on the object to be sealed. It consists in packaging, characterized in that remain.

  According to the present invention, there is provided a package having excellent food hygiene, good easy-openability, and air permeability that allows oxygen to permeate through the thin film layer remaining on the sealed object after opening, and the meat color red in a short time. The industrial value of the present invention is high.

Partial sectional view of the package of the present invention Partial sectional view of the package in a state in which a part of the lid member is peeled off from the bottom material. Hereinafter, the present invention will be described in detail. In the present specification, “configured as a main component” is intended to allow other components to be included within a range that does not impede the action and effect of the resin constituting each layer. Further, this term does not limit the specific content, but it is 70% by mass or more and 100% by mass or less, preferably 85% by mass or more and 100% by mass or less, more preferably 95% by mass, based on the total components of each layer. It means to occupy 100% by mass or less.

  The film used in the present invention has a surface resin layer (A), an oxygen barrier resin layer (B), a pinhole-resistant resin layer (C), and a heat seal resin layer (D), (A) / (B) / It is laminated in the order of (C) / (D), and consists of a layer having a peel strength of 0.05 to 5.0 N / 15 mm width between the oxygen barrier resin layer (B) and the pinhole resistant resin layer (C). It is a multilayer film, and this is used as a lid. By heat-sealing the heat-seal resin layer (D) of the multilayer film to the seal part of the object to be sealed, a package body in which the bottom material and the lid material are heat-sealed is obtained, and the multilayer film is peeled off at the heat-seal part. The pinhole-resistant resin layer (C) and the heat seal (D) are delaminated, and the surface resin layer (A), the oxygen barrier resin layer (B), and the pinhole-resistant resin layer (C ) Is removed, and the thin film layer of the heat seal resin layer (D) remains exposed on the sealed body, and oxygen in the atmosphere enters the package.

  First, the surface resin layer (A) of the film used in the present invention will be described. The surface resin layer (A) is a layer composed mainly of the thermoplastic resin (a), and the delamination strength between the surface resin layer (A) and the oxygen barrier resin layer (B) at the time of peeling is There is no particular limitation as long as the layer structure is greater than the delamination strength between the pinhole-resistant resin layer (C) and the heat seal resin layer (D). There may be.

  The thermoplastic resin (a) used as the main component of the surface resin layer (A) is the main component of the oxygen barrier resin layer (B), the pinhole-resistant resin layer (C), and the heat seal resin layer (D). It is necessary to select appropriately considering the type of resin used. Since the thermoplastic resin (a) has a melt extrusion temperature in a range of approximately 180 ° C. or more and 300 ° C. or less, a thermoplastic resin that can be melt extruded within this range is suitably used. Specific examples of the thermoplastic resin (a) include olefin resins (ethylene resins, propylene resins, cyclic olefin resins, etc.), amide resins, saponified ethylene-vinyl acetate copolymers, ester resins, Examples thereof include styrene resins and carbonate resins. These thermoplastic resins can be used alone or as a mixed resin composition of two or more, and can form a single layer structure or a multilayer structure.

  In the present invention, in view of molding processability, production cost, transparency, etc., the thermoplastic resin (a) includes olefin resin, amide resin, saponified ethylene-vinyl acetate copolymer, ester resin, and styrene. At least one thermoplastic resin selected from the group consisting of a series resin can be suitably used.

  Examples of ethylene resins include ethylene 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); -Vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate copolymer (EMA), ethylene-acrylic acid copolymer Copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-glycidyl methacrylate copolymer (E-GMA), ethylene-vinyl acetate-glycidyl methacrylate copolymer (E-VA-GMA), ethylene-anhydrous Maleic acid copolymer (E-MAH , Ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH), and other ethylene copolymers; further, metal-neutralized ethylene-acrylic acid copolymers, ethylene-methacrylic acid copolymers And the neutralized metal. These may be used alone or in combination of two or more.

  Examples of the propylene-based resin include propylene homopolymers and copolymers of propylene and other α-olefins such as ethylene and butene. As the copolymers, both random copolymers and block copolymers are used. Can be used. The stereoregularity may be any of an isotactic structure, a syndiotactic structure, an atactic structure, a stereo block structure, and the like. These may be used alone or in combination of two or more.

  Examples of the amide resin include, as aliphatic polyamide polymers, ring-opening polymers of cyclic lactams, polycondensates of aminocarboxylic acids, polycondensates of dicarboxylic acids and diamines, and the like. Specifically, a homopolymer of ε-caprolactam referred to as 6 nylon, polyhexamethylene adipamide referred to as 66 nylon, or 6-66 nylon as a copolymer thereof can be used. Moreover, as an aromatic polyamide polymer, a resin or the like containing 70 mol% or more of a polyamide constituent unit composed of xylylenediamine and an α, ω aliphatic dicarboxylic acid having 6 to 12 carbon atoms in the molecular chain. Can be used. Specifically, homopolymers such as polymetaxylylene adipamide, polymetaxylylene pimeramide, polymetaxylylene azeramide, polyparaxylylene azeramide, polyparaxylylene decanamide, metaxylylene / paraxylylene azamide Examples of the copolymer include a amide copolymer, a metaxylylene / paraxylylene pimeramide copolymer, a metaxylylene / paraxylylene azeramide copolymer, and a metaxylylene / paraxylylene sepacamide copolymer. These may be used alone or in combination of two or more.

  The saponified ethylene-vinyl acetate copolymer has an ethylene content of 29% or more, preferably 32% or more, and 47 mol% or less, preferably 44 mol% or less, and a saponification degree of 90% or more. Preferably, 95% or more is suitably used. By selecting a grade in which the ethylene content and the degree of saponification are in the above ranges, the gas barrier properties and mechanical strength of the film can be improved. These may be used alone or in combination of two or more.

  Examples of ester resins include polyethylene terephthalate resin, polypropylene terephthalate resin, polybutylene terephthalate resin, polyethylene isophthalate resin, polyethylene naphthalate resin, polybutylene naphthalate resin, polyethylene terephthalate / isophthalate copolymer resin, 1,4-cyclohexanedi Fatty typified by low crystalline or amorphous polyethylene terephthalate resin, polyethylene / neopentyl terephthalate copolymer resin, polylactic acid-based resin containing 15 to 50 mol% of methanol units in all glycol monomer units Group polyester resins and the like.

  In addition, a thermoplastic polyester elastomer having a high melting point and high crystallinity aromatic polyester as a hard segment and an amorphous polyester or amorphous polyether as a soft segment may be appropriately mixed with the ester resin. These elastomers may be used alone or in a suitable mixture of two or more.

  As the styrene resin, general-purpose polystyrene (GPPS), high impact polystyrene (HIPS), styrene- (meth) acrylic acid ester copolymer, a continuous styrene copolymer composed of a styrene-based monomer and a (meth) acrylic acid ester. Examples thereof include a resin containing 1% by mass or more and 20% by mass or less of a rubber-like elastic body as dispersed particles. These may be used alone or in combination of two or more.

  Other components may be appropriately added to the surface resin layer (A) as long as the gist of the present invention is not impaired. Specific examples include components such as an antifogging agent, an antistatic agent, a heat stabilizer, a nucleating agent, an antioxidant, a lubricant, an antiblocking agent, a release agent, and an ultraviolet absorber. When the surface resin layer (A) has a multilayer structure, it may be added only to a specific layer or may be added to all layers.

Next, the oxygen barrier resin layer (B) of the film used in the present invention will be described. The oxygen barrier resin layer (B) has an ethylene-vinyl acetate having a barrier property of 3 (cc · 20 μm / m ² · 24 hr · atm) or less at least in an environment where the oxygen permeability is 23 ° C. and 50% RH. Examples thereof include saponified copolymer (EVOH) or polymetaxylene adipamide resin (MXDNy).

Here, if the oxygen permeability is 3 (cc · 20 μm / m ² · 24 hr · atm) or less in an environment of 23 ° C. and 50% RH, the head space of the package is replaced with nitrogen or carbon dioxide gas. It is preferable because a low oxygen state (preferably an oxygen concentration of 0.3% or less) can be maintained for a certain period of time until it is displayed at the store.

  The saponified ethylene-vinyl acetate copolymer has an ethylene content of usually 29% or more, preferably 32% or more, and usually 47 mol% or less, preferably 44 mol% or less, and has a saponification degree. 90% or more, preferably 95% or more is suitably used. By selecting a grade in which the ethylene content and the degree of saponification are in the above ranges, the gas barrier properties and mechanical strength of the film can be improved. These may be used alone or in combination of two or more.

  Next, the pinhole resistant resin layer (C) of the film used in the present invention will be described. The pinhole-resistant resin layer (C) is a layer mainly composed of the thermoplastic resin (c), and between the pinhole-resistant resin layer (C) and the heat seal resin layer (D) at the time of delamination. The delamination strength between the surface resin layer (A) and the oxygen barrier resin layer (B) and between the oxygen barrier resin layer (B) and the pinhole resistant resin layer (C) The layer structure is not particularly limited as long as it is smaller than that, and may be a single layer or a multilayer as desired.

  The thermoplastic resin (c) contained as the main component of the pinhole-resistant resin layer (C) has a melt extrusion temperature of about the same as the thermoplastic resin (a) constituting the main component of the surface resin layer (A). A thermoplastic resin that can be melt extruded at 180 ° C. or higher and 300 ° C. or lower is preferably used. Specifically, as the thermoplastic resin (c), even if mechanically perforated from the side of the heat seal layer (D) in order to further improve the air permeability, the hole that is opened is the depth of the oxygen barrier resin (B). There are pinhole resistance and excellent rigidity so as not to reach the limit. In consideration of molding processability and transparency that are industrially stable and available at a relatively low cost, at least one selected from the group consisting of amide resins, ester resins, polypropylene resins, and cyclic polyolefin resins. A thermoplastic resin is mentioned.

  If the hole drilled to the surface resin layer (A) and the oxygen barrier resin layer (B) penetrates, the oxygen barrier property is deteriorated, so the surface resin layer (A) and the oxygen barrier resin layer (B) It is necessary not to penetrate. There are mechanical or electrical approaches such as laser, electrostatic discharge, ultrasonic wave, flame discharge, needle, etc., but the depth of the needle or blade is mechanically adjusted in units of several μm to make it half-cut. When a hole is made, a pinhole-resistant and rigid layer is disposed between the oxygen barrier resin layer (B) and the heat seal resin layer (D), so that the heat seal resin layer (D) side The perforated hole can be prevented from penetrating to the oxygen barrier resin layer (B). Among them, an amide-based resin rich in rigidity and flexibility is preferable because it has a property of deforming following the shape of the needle or blade even when the needle or blade reaches the pinhole-resistant resin layer.

  Examples of the aliphatic polyamide polymer include a ring-opening polymer of cyclic lactam, a polycondensate of aminocarboxylic acid, and a polycondensate of dicarboxylic acid and diamine. Specifically, a homopolymer of ε-caprolactam referred to as 6 nylon, polyhexamethylene adipamide referred to as 66 nylon, or 6-66 nylon as a copolymer thereof can be used. Moreover, as an aromatic polyamide polymer, a resin or the like containing 70 mol% or more of a polyamide constituent unit composed of xylylenediamine and an α, ω aliphatic dicarboxylic acid having 6 to 12 carbon atoms in the molecular chain. Can be used. Specifically, homopolymers such as polymetaxylylene adipamide, polymetaxylylene pimeramide, polymetaxylylene azeramide, polyparaxylylene azeramide, polyparaxylylene decanamide, metaxylylene / paraxylylene azamide Examples of the copolymer include a amide copolymer, a metaxylylene / paraxylylene pimeramide copolymer, a metaxylylene / paraxylylene azeramide copolymer, and a metaxylylene / paraxylylene sepacamide copolymer. These may be used alone or in combination of two or more. Nylon resin (Ny) is preferably used from the viewpoint of rigidity and pinhole resistance. As Ny, for example, 6 nylon, 66 nylon, 69 nylon, 6-66 nylon, 12 nylon, 11 nylon, 610 nylon, Examples thereof include polymers of condensed units such as 612 nylon, 6I-6T nylon, MXD6 nylon and the like, copolymers with two or more of these, and mixtures thereof. Among them, 6 nylon or 6-66 nylon is preferably used in terms of rigidity, flexibility, and tear resistance (preventing film tearing when opened).

  Here, the amide-based resin can be easily obtained from each company, for example, trade names “Novamid 1020A (6 nylon)”, “2030A (6-66 nylon)” manufactured by DSM Engineering Plastics Co., Ltd. or Ube A product name “UBE nylon 1022B (6 nylon)” manufactured by Kosan Co., Ltd. can be exemplified.

  In addition, the pinhole resistant resin layer (C) is likely to bleed on the surface of the pinhole resistant resin layer (C) in order to develop a stable peelability between the oxygen barrier resin layer (B) and the pinhole resistant resin layer (C). It is preferable not to mix additives as much as possible.

Next, the heat seal resin layer (D) of the film of the present invention will be described. The heat seal resin layer (D) has an oxygen permeability of at least 25,000 cc / (m 2 · 24 h · atm) in a 23 ° C./50% RH environment, and is mainly composed of the thermoplastic resin (d). It is a heat sealable resin layer. It is important that the heat seal resin layer (D) has good air permeability, preferably oxygen of 30,000 cc / (m 2 · 24 h · atm) or more, more preferably 50,000 (m ² · 24 h · atm) or more. What has the transmittance | permeability is used suitably.

  Further, when heat sealing is performed at the heat seal portion of the object to be sealed and then the multilayer film is peeled from the heat seal portion, delamination between the pinhole-resistant resin layer (C) and the heat seal resin layer (D) There is no particular limitation as long as the layer structure is such that the strength is lower than the delamination strength between the oxygen barrier resin layer (B) and the pinhole-resistant resin layer (C), and a single layer is desired if desired. It may be a resin layer having a structure or a resin layer having a multilayer structure.

  The thermoplastic resin (d) that constitutes the main component of the heat seal resin layer (D) is used when the film of the present invention is used as a lid for a package, and the sealing surface material and surface resin of the bottom material to be sealed Appropriately select a resin that provides appropriate heat seal strength in consideration of the type of resin used as the main component of the layer (A), the oxygen barrier resin layer (B), and the pinhole resistant resin layer (C) Can be used. Examples of the thermoplastic resin (d) include olefin resins (ethylene resins, propylene resins, etc.), styrene resins, ester resins, styrene thermoplastic elastomers, and the like.

  Among these, in the present invention, the oxygen transmission rate is high, it is inexpensive and excellent in molding processability, etc., and it is resistant to pinholes under the heat seal conditions (temperature: about 120 to 180 ° C.) usually employed in various multilayer films. The delamination strength between the heat-resistant resin layer (C) and the heat seal resin layer (D) may be smaller than the delamination strength between the oxygen barrier resin layer (B) and the pinhole-resistant resin layer (C). Ethylene resins such as very low density polyethylene (VLDPE), linear low density polyethylene (LLDPE), low density polyethylene (LDPE); ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer ( EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate copolymer (EMA), ethylene-acrylic Copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-glycidyl methacrylate copolymer (E-GMA), ethylene-vinyl acetate-glycidyl methacrylate copolymer (E-VA-GMA), ethylene -Ethylene copolymer such as maleic anhydride copolymer (E-MAH) ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH); and metal of ethylene-acrylic acid copolymer Examples include neutralized products, and metal-neutralized products of ethylene-methacrylic acid copolymers. These may be used alone or in combination of two or more.

  Examples of the propylene-based resin include propylene homopolymers and copolymers of propylene and other α-olefins such as ethylene and butene. As the copolymers, both random copolymers and block copolymers are used. Can be used. The stereoregularity may be any of an isotactic structure, a syndiotactic structure, an atactic structure, a stereo block structure, and the like. These may be used alone or in combination of two or more.

  In order to further improve oxygen permeability, it is preferable to open a large number of minute holes. If the pore diameter is usually 0.01 to 1 mm (preferably 0.1 to 0.6 mm), oxygen invades, but dust, insects and the like cannot enter and are hygienic. Moreover, since the holes are scattered on the film surface, the contents are not made difficult to see.

  It is preferable to add a lubricant or an anti-blocking agent to the heat seal resin layer (D) as appropriate from the viewpoints of processing suitability during extrusion film formation and packaging suitability in a filling machine such as a deep drawing packaging machine. Furthermore, other components may be appropriately added within a range not impairing the gist of the present invention. Specific examples include antifogging agents, antistatic agents, heat stabilizers, nucleating agents, antioxidants, mold release agents, and ultraviolet absorbers.

  The heat seal resin layer (D) may contain an adhesive resin in the heat seal resin layer (D) in order to control delamination between the pinhole resistant resin layer (C), or An adhesive resin layer (E) composed mainly of an adhesive resin can be disposed between the pinhole-resistant resin layer (C) and the heat seal resin layer (D).

  Here, as the adhesive resin, linear low density polyethylene (LLDPE), low density polyethylene (LDPE), ethylene-based resins such as ethylene-vinyl acetate copolymer (EVA), propylene homopolymer, and propylene Monopropylene unsaturated fatty acid such as acrylic acid or methacrylic acid, or monobasic such as methyl acrylate, methyl methacrylate, or glycidyl methacrylate Olefinic Adhesive Resin with Chemically Bonded Ester Compounds of Polyunsaturated Fatty Acids or Dibasic Fatty Acid Anhydrides such as Maleic Acid, Fumaric Acid or Itaconic Acid, and Styrene / Ethylene Butylene / Styrene Block Copolymer Combined (SEBS) and styrene / ethylene butylene -Styrenic thermoplastic elastomers containing polar functional groups such as carboxyl groups, acid anhydride groups, epoxy groups, and amino groups in styrene thermoplastic elastomers such as olefin crystal block copolymers (SEBC) An adhesive resin is preferably used. For example, the adhesion between the pinhole-resistant resin layer (C) and the heat seal resin layer (D) can be achieved by blending two or more types of other resins to the adhesive resin layer (E) to reduce the concentration. The opening can be changed by reducing the strength.

  As a specific example of such an adhesive resin, in the former olefin-based adhesive resin, a product name “Admer” manufactured by Mitsui Chemicals, Inc., a product name “Modic” manufactured by Mitsubishi Chemical Corporation, and the like can be exemplified. . Examples of the latter styrene-based thermoplastic elastomer-based adhesive resin include the trade name “Dynalon” manufactured by JSR Corporation and the product name “Tuftec” manufactured by Asahi Kasei Chemicals Corporation.

  The film used in the present invention has a heat-sealing resin layer (D) when the heat-sealing resin layer (D) of the film is heat-sealed at the heat-sealing portion of the object to be sealed, and then the multilayer film is peeled off from the heat-sealing portion. ) Is exposed by delamination of the pinhole-resistant resin layer (C) and the heat-sealable resin layer (D) in the heat-seal portion and the movement of the heat-seal resin layer (D) to the sealed object side. Therefore, as a combination of resins selected for each layer, the delamination strength between the pinhole-resistant resin layer (C) and the heat seal resin layer (D) is different from the surface resin layer (A) and the oxygen barrier. It is preferable to make it the structure which becomes smaller than the delamination strength between the resin layers (B) and between the oxygen barrier resin layer (B) and the pinhole resistant resin layer (C). At the same time, it is also important to ensure the delamination strength to such an extent that the function as a package can be maintained so that the layers are not easily peeled off or opened by a slight impact.

  From these viewpoints, the combination of resins selected for the pinhole-resistant resin layer (C) and the heat-sealable resin layer (D) has an interlayer peel strength (initial peel strength) of 0.05 N / 15 mm width or more and 5 N / It is preferable to select a range of 15 mm or less. Here, if the delamination strength is 0.05 N / 15 mm width or more, problems such as the package being easily opened by a slight impact are unlikely to occur, and if it is 5 N / 15 mm width or less, This is preferable because the easy-opening property, which is a characteristic that allows easy opening of the package by hand, is good.

In the present invention, as a suitable combination of the surface resin layer (A), the oxygen barrier resin layer (B), the pinhole resistant resin layer (C) and the heat seal resin layer (D) satisfying such conditions, As described above, the surface resin layer (A) is at least one selected from the group consisting of olefin resins, amide resins, saponified ethylene-vinyl acetate copolymers, ester resins, styrene resins, and carbonate resins. A layer composed mainly of various thermoplastic resins is arranged, and an oxygen-barrier resin layer (B) is saponified ethylene-vinyl acetate copolymer (EVOH) or polymetaxylene adipamide resin (MXDNy) Selected from the group consisting of a resin whose main component is at least 3 (cc · 20μm / m2 · 24h · atm) at 23 ° C and 50% RH. The pinhole resistant resin layer (C) is mainly composed of one kind of thermoplastic resin selected from the group consisting of amide resins, ester resins, polypropylene resins, and cyclic polyolefin resins. A layer constituted as a component is disposed, and the oxygen permeability of the heat seal resin layer (D) is at least 25,000 cc / (m ² · 24 h · atm) or more in an environment of 23 ° C. and 50% RH. , Propylene resin, ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-metal methacrylate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic At least one thermoplastic selected from the group consisting of acid copolymers, ionomers and 4-methyl-1-pentene. That arranged layers composed of fat as a main component can be mentioned.

  Next, the thickness of each layer described above will be described. The surface resin layer (A) is a resin layer having a single layer or a multilayer structure, and usually has a thickness of 1 μm or more, preferably 10 μm or more, more preferably 20 μm or more, and 1000 μm or less, preferably 600 μm or less, Preferably it is 500 micrometers or less. Here, if the thickness of the surface resin layer (A) is 1 μm or more, it is easy to dispose a layer imparting characteristics such as gas barrier properties and pinhole resistance and an adhesive resin layer, and the thickness thereof. Is preferably 1000 μm or less, because heat can be easily transferred to the heat seal resin layer (D) during heat sealing, and can be easily heat sealed with the sealing portion of the object to be sealed.

The oxygen barrier resin layer (B) is usually a resin layer having a single layer structure, and has a thickness of 3 (cc · 20 μm / m ² · 24 hr · at least in an environment where the oxygen permeability is 23 ° C. and 50% RH. atm) or less, and from the viewpoint of molding processability, production cost, etc., it is usually 2 μm or more, preferably 5 μm or more, more preferably 10 μm or more and 100 μm or less, preferably 70 μm or less, More preferably, 50 μm or less is suitably employed.

  The thickness of the pinhole resistant resin layer (C) is usually 5 μm or more, preferably 10 μm or more, more preferably 15 μm or more, and is usually 100 μm or less, preferably 50 μm or less, more preferably 30 μm or less. In order to further enhance the effect of oxygen permeability, it is preferable to mechanically perforate from the heat seal resin layer (D) side, and if the pinhole resistant resin layer (C) has a thickness of 5 μm or more, the heat seal resin layer (D) From the side, even if a fine hole is made by drilling with a needle or blade, the hole does not reach the oxygen barrier resin layer due to the presence of a highly rigid pinhole-resistant resin layer. It is preferable that the thickness is 100 μm or less. When the pinhole-resistant resin layer (C) and the heat seal resin layer (D) are peeled off, the heat seal resin layer (D) can be easily removed. It is preferable because the film can be exposed.

  The thickness of the heat seal resin layer (D) is not particularly limited, but is usually 5 μm or more, preferably 10 μm or more, more preferably 15 μm or more, and usually 100 μm or less, preferably 50 μm or less, more preferably 30 μm. The following is desirable. Here, if the total thickness is 5 μm or more, it will be deformed by pressurization with a heat seal hot plate at the time of heat sealing, the function of this layer will be reduced, or the seal layer will be broken at the time of delamination, When the surface resin layer (A) / oxygen barrier resin layer (B) / pinhole resistant resin layer (C) is peeled off and a package with a thin film of the heat seal resin layer (D) remaining on the storefront is displayed Furthermore, it is preferable because problems such as tearing of the heat seal resin layer (D) can be prevented, and a thickness of 30 μm or less is preferable because a state of high air permeability can be maintained.

  An adhesive resin layer (E) composed mainly of an olefin-based adhesive resin and / or a styrene-based thermoplastic elastomer is disposed between the pinhole-resistant resin layer (C) and the heat seal resin layer (D). In this case, the thickness is usually 1 μm or more, preferably 3 μm or more, more preferably 5 μm or more, and it is easy to manage the manufacturing process and quality, and a stable peel strength can be obtained. When the thickness is 15 μm or more, the tendency to increase the peel strength is increased. Therefore, the thickness is preferably 30 μm or less, more preferably 25 m or less, and particularly preferably 15 μm or less.

  Next, the manufacturing method of the film used by this invention is demonstrated.

  The production method of the film used in the present invention is not particularly limited, but is excellent in protection, productivity and hygiene of the oxygen barrier resin layer (B) and the pinhole resistant resin layer (C). The co-extrusion method can be preferably used. That is, each of the resin compositions used for the surface resin layer (A), the oxygen barrier resin layer (B), the pinhole resistant resin layer (C), and the heat seal resin layer (D) described above is a separate extruder. And then laminated in the order of (A) / (B) / (C) / (D) in a molten state by a known method such as a multi-manifold method or a feed block method, and then the T die / chill roll method or inflation It can be formed into a multilayer film by a method or the like. Here, in order to improve printing suitability and laminating suitability, surface treatment may be applied to the surface of the outermost layer of the surface resin layer (A) of the obtained multilayer film. Examples of the surface treatment include corona treatment, plasma treatment, chromic acid treatment, flame treatment, surface oxidation treatment such as hot air treatment ozone / ultraviolet treatment, and surface unevenness treatment such as sand blasting. Corona treatment is preferably used from the viewpoint of treatment effect, productivity, and manufacturing cost.

  The film used in the present invention is formed by applying a laminate base material on the surface resin layer (A) via an adhesive resin or an adhesive, if necessary, by a known method such as a dry lamination method or an extrusion lamination method. It can be laminated to form a laminate film or laminate sheet. Here, the laminate substrate is not particularly limited. For example, a biaxially stretched polypropylene film, a biaxially stretched nylon film, a biaxially stretched polyethylene terephthalate film, an unstretched polypropylene sheet, an unstretched polyethylene terephthalate sheet, An aluminum foil, paper, a nonwoven fabric, etc. are mentioned. In the present invention, a dry lamination method is preferably used, and examples of the adhesive used at that time include a polyester-polyurethane adhesive and a polyether-polyurethane adhesive.

  The film itself used in the present invention, or the laminate film or laminate sheet obtained by laminating the film used in the present invention and the laminate base material can be used as a cover material for various packaging bodies. When the film is used as a lid of a package (container), the heat of the lid (heat seal resin layer (D)) and the package (container) (sealed body) filled with contents such as food By overlapping and heat-sealing the sealing resin layer, a package (container) having airtightness, practical delamination strength and air permeability can be obtained. In this package (container), the film of the heat-sealable resin layer (D) is exposed on the bottom material after opening, and oxygen in the atmosphere flows into the package due to high air permeability. It becomes possible to make the meat a red and vivid color that consumers want when displaying at the store.

  Next, delamination and breathability in a deep drawn package using the film of the present invention as a lid will be described. FIG. 1 is a partial cross-sectional view of a deep-drawn package using the film of the present invention as a lid, and FIG. 2 is a diagram of the deep-drawn package shown in FIG. It is a fragmentary sectional view of the package in a state.

  1 and 2, reference numeral 1 is a lid member, reference numeral 2 is a bottom material (sealed body), reference numeral 3 is a surface resin layer of the lid member, reference numeral 4 is an oxygen barrier resin layer of the lid member, and reference numeral 5. Is a pinhole resistant resin layer of the lid material, 6 is a heat seal resin layer of the lid material, 7 is a surface resin layer of the bottom material, 8 is a heat seal resin layer of the bottom material, 9 is a heat seal portion, Reference numeral 10 denotes a tab portion, reference numeral 11 denotes an exposed portion of the pinhole-resistant resin layer 5 at the time of peeling, and reference numeral 12 denotes an exposed portion of the heat seal resin layer 8 at the time of peeling.

  As shown in FIG. 1, the lid member 1 includes a surface resin layer 3, an oxygen barrier resin layer 4, a pinhole resistant resin layer 5, and a heat seal resin layer 6 in this order. The heat seal resin layer 6 of the lid 1 is heat-sealed with the heat seal resin layer 8 of the bottom material 2 that is the object to be sealed. That is, the lid member 1 and the bottom member 2 are bonded by the heat seal portion 9 formed by heat sealing.

  When the tab portion 10 provided on the lid material 1 is picked and pulled, as shown in FIG. 2, in the heat seal portion 9, the heat seal resin layer 6 on the tab portion 10 side is first broken from the lid material 1, Peeling is started between the pinhole-resistant resin layer 5 and the heat seal resin layer 6 in the lid material 1. Even after the peeling between the pinhole-resistant resin layer 5 and the heat seal resin layer 6 reaches the heat seal portion 9 on the side opposite to the tab portion 10 side, the heat seal resin layer of the lid 1 is not broken, and the sheet is covered. The exposed portion 11 of the pinhole-resistant resin layer 5 and the exposed portion 12 of the heat seal resin layer 6 are formed.

  The package constituted by the film of the present invention can be used as a lid for various containers, and its use is particularly related to packaging of fresh raw meat products in general, such as beef, pork, chicken, venison, lamb, etc. When the raw meat is disassembled and packaged and displayed at a retail store such as a supermarket, the oxygen barrier film part of the lid is peeled off to expose the heat seal resin layer and leave the film, so that a single package (with the lid Tray container).

  In particular, after peeling off the oxygen barrier film portion on the surface layer, oxygen in the atmosphere flows into the package, which makes it possible to produce meat that has a bright red color that consumers prefer.

  The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. In addition, various evaluation about the film displayed in this specification was performed as follows.

(1) Peel strength The bottom material of the obtained deep-drawn package and the heat seal part of the lid were cut into strips having a width of 15 mm to form test pieces. When this specimen is pulled at an angle of 180 degrees under the conditions of a temperature of 23 ° C. and a tensile speed of 200 mm / min using a universal testing machine (manufactured by Intesco Corp.), peeling when the bottom material and the lid material are peeled The strength was measured as the initial peel strength (N / 15 mm width).

(2) Oxygen barrier property The raw material of the deep-drawn package was filled with fresh raw beef and stored in a refrigerator at 2 ° C for 21 days. It was evaluated by. (The head space of the package was replaced with nitrogen gas so that the initial oxygen concentration was 0.01% or less.)
○: When purple color is maintained ×: When the color is changed to black-red or when the decay has progressed

(3) Delamination property The state of the heat seal resin layer (D) when the lid material was peeled by hand from the heat seal portion of the obtained deep-drawn package was visually evaluated according to the following criteria.
○: When the heat-seal resin layer is exposed cleanly and a thin film remains on the bottom material ×: When the heat-seal resin layer is not exposed, breaks, or has fluff

(4) Colored state of raw meat The raw material of the deep drawn package was filled with fresh raw beef and peeled by hand from the heat seal part, leaving a thin film of the heat seal resin layer In the state, the coloring state of raw meat when stored in a refrigerator at 2 ° C. for 12 hours was visually evaluated according to the following criteria.
○: When the color changes from purple to vivid red ×: When the color remains purple or decays with black-red

Example 1:
[Cover material]
The surface resin layer (A) has a three-layer structure using the following three types of resins.
A1: 6 nylon resin (DSM Engineering Plastics Co., Ltd., trade name “Novamid 1020A”, hereinafter abbreviated as “6Ny”)
A2: Olefin-based adhesive resin (manufactured by Mitsui Chemicals, trade name “Admer NF587”, hereinafter abbreviated as “AD1”)
A3: 6-66 nylon resin (manufactured by DM Engineering Plastics Co., Ltd., trade name “Novamid 2030A”, hereinafter abbreviated as “6-66Ny”)
The oxygen barrier resin layer (B) is a saponified ethylene-vinyl acetate copolymer (manufactured by Kuraray Co., Ltd., trade name “Eval E105”, ethylene copolymerization ratio: 44 mol, oxygen permeability: 1.5 (cc 20 μm / m 2 · 24 h · atm), hereinafter abbreviated as “EVOH1”)).

  The pinhole-resistant resin layer (C) was formed using a resin of 6 nylon resin (manufactured by DSM Engineering Plastics Co., Ltd., trade name “Novamid 1020A”, hereinafter abbreviated as “6Ny”).

  The heat seal resin layer (D) is composed of ethylene-vinyl acetate copolymer (Japanese polyethylene trade name “Novatech EVA LV430”, hereinafter abbreviated as “EVA”) with 1000 ppm of erucamide as a lubricant and natural silica as an antiblocking agent. Of 2000 ppm was added and mixed.

  (A) Extruder for layer (single screw extruder of 50 mm in diameter for all three layers), (B) Extruder for layer (single screw extruder of 50 mm in diameter), (C) Extruder for layer (caliber) 50 mm single screw extruder) and (D) layer extruder (50 mm bore single screw extruder) Co-extruded under the conditions of a temperature of 190 to 250 ° C. and a T die set temperature of 255 ° C., and the average of each layer in a six-layer configuration of (A1) / (A2) / (A3) / (B) / (C) / (D) A multilayer film (X1) having a thickness of 10 μm / 10 μm / 10 μm / 10 μm / 10 μm / 20 μm and a total thickness of 70 μm was obtained.

[Bottom material]
From the outermost layer side, EVOH1, 6-66Ny, AD1, linear low density polyethylene resin (manufactured by Nippon Polyethylene Co., Ltd., trade name “NOVATEC LL UF240”, hereinafter abbreviated as “LLDPE”) as erucic acid amide as a lubricant Is laminated in the order of a resin composition (heat seal resin layer) in which 1000 ppm of natural silica is added and mixed as an antiblocking agent, and the average thickness of each layer is 10 μm / 20 μm / 10 μm / 30 μm, respectively, and the total thickness is 70 μm. A multilayer film (Y1) was obtained by coextrusion. An unstretched polyethylene terephthalate sheet (Mitsubishi Chemical Co., Ltd., trade name “Novaclear”) having a total thickness of 250 μm is bonded to the outermost layer side (EVOH surface) of this multilayer film (Y1) by a dry lamination method. A laminate sheet (Y1LS) having a thickness of 320 μm was obtained and used as the bottom material of the package.
As an adhesive for dry lamination, a two-component curable adhesive (manufactured by Dainippon Ink Co., Ltd. as a main agent, trade name “Dick Dry LX-75A”, a product of Dainippon Ink Co., Ltd. as a curing agent, trade name “Dick Dry KW-40” was used.

[Deep-drawn packaging]
Using a deep-drawing packaging machine (manufactured by Mulchback, model number: R-530), the bottom material (Y1LS) is deep-drawn so that the non-stretched polyethylene terephthalate sheet layer is an outer layer, and the length is 130 mm. The container is processed into a rectangular container having a width of 170 mm and a flange width of 6 mm. In the heat seal portion, the above-mentioned cover material (X1) is applied to the flange portion provided on the deeply drawn bottom material, and the heat seal temperature: 140 A deep-drawn package was produced by heat sealing under the conditions of ° C., sealing time: 2 seconds, and sealing pressure: 4 kg / cm 2. The head space of the deep drawn package was filled with nitrogen gas and replaced with an oxygen concentration of 0.01% or less.
The results of evaluation using this deep-drawn package are shown in Table 1.

Example 2:
[Cover material]
Resin used for the surface resin layer (A) used in Example 1 is A1: EVOH1, A2: 6-66Ny A3: Olefin-based adhesive resin (trade name “Admer NF587” manufactured by Mitsui Chemicals, Inc.) Except for the change to “AD1”), a six-layer configuration of (A1) / (A2) / (A3) / (B) / (C) / (D) is used in the same manner as in Example 1. A multilayer film (X2) having an average thickness of each layer of 10 μm / 10 μm / 10 μm / 10 μm / 10 μm / 20 μm and a total thickness of 70 μm was obtained.

  Next, on the outermost layer side of the surface resin layer (A) of the obtained multilayer film (X2), a biaxially stretched polyethylene terephthalate film substrate (trade name “Emblet PET”, thickness 16 μm, manufactured by Unitika Ltd.) is placed. By laminating by the dry lamination method, a laminate film (X2LF) having a total thickness of 86 μm was obtained and used as a cover material of the package. In addition, the same adhesive as Y1LS was used as an adhesive for dry lamination.

[Bottom material]
As in Example 1, a laminate sheet (Y1LS) was used as the bottom material of the package.

[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

Example 3:
[Cover material]
The resin used for the oxygen-barrier resin layer (B) used in Example 1 was a polymetaxylene adipamide resin (Mitsubishi Gas Chemical Co., Ltd., trade name “MX Nylon S6007”, hereinafter abbreviated as “MXDNy”). The average thickness of each layer is the same as in Example 1 except that the average thickness of each layer is 6 layers (A1) / (A2) / (A3) / (B) / (C) / (D). A multilayer film (X3) having a thickness of 10 μm / 10 μm / 10 μm / 10 μm / 10 μm / 20 μm and a total thickness of 70 μm was obtained and used as a lid for the package.

[Bottom material]
As in Example 1, a laminate sheet (Y1LS) was used as the bottom material of the package.
[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

Example 4:
[Cover material]
The surface resin layer (A) has a two-layer structure using A1: 6Ny and A2: 6-66Ny, and the resin used for the pinhole-resistant resin layer (C) used in Example 1 is an amorphous polyester resin. (Eastman Chemical Co., Ltd., trade name “EASTARPETPG Copolyester6763”, hereinafter abbreviated as “PETG”), and between oxygen barrier resin layer (B) and pinhole resistant resin layer (C) In the same manner as in Example 1, except that an olefin-based adhesive resin (trade name “Admer SF715”, hereinafter abbreviated as “AD2”) is provided as an adhesive resin layer (E). , (A1) / (A2) / (B) / (E) / (C) / (D), the average thickness of each layer is 10 μm / 10 μm / 10 μm / 10 μm / 10 μm / 20 μm, respectively Layer thickness is 7 Obtain a multilayer film (X4) of [mu] m, it was used in the lid of the package.
[Bottom material]
As in Example 1, a laminate sheet (Y1LS) was used as the bottom material of the package.
[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

Example 5:
[Cover material]
The surface resin layer (A) has a two-layer structure using A1: 6Ny and A2: 6-66Ny, and the resin used for the pinhole-resistant resin layer (C) used in Example 1 is a cycloolefin polymer resin, ( Made by Polyplastics Co., Ltd., trade name “ZEONOR 1020R” (hereinafter abbreviated as “COP”), and between the oxygen barrier resin layer (B) and the pinhole resistant resin layer (C). Example 1 except that the heat-adhesive resin AD1 was changed and the heat seal resin layer (D) was changed to random polypropylene (trade name “Novatech PP EG7FTB”, hereinafter abbreviated as PP1) manufactured by Nippon Polypro Co., Ltd. In the same manner, the average thickness of each layer is 10 μm / 10 μm / 10 μm / 10 μm / 10 μm in a six-layer configuration of (A1) / (A2) / (B) / (E) / (C) / (D). / 0 .mu.m, the thickness of all the layers to obtain a 70μm multi-layer film (X5), was used in the lid of the package. Next, holes having a hole diameter of 0.1 mm and a depth of 30 μm were opened with a mechanical needle at intervals of 10 mm × 10 mm from the innermost layer side of the obtained multilayer film (X5), and used as a lid for the package.

[Bottom material]
Except that the heat seal resin layer used in Example 1 was changed to random polypropylene (trade name “Novatech PP EG7F”, hereinafter abbreviated as PP2 manufactured by Nippon Polypro Co., Ltd.), the same as in Example 1, From the outermost layer side, EVOH1, 6-66Ny, AD1, PP1 were laminated in order of a resin composition (heat seal resin layer) in which 1000 ppm of erucamide was added as a lubricant and 2000 ppm of natural silica was added as an antiblocking agent. A multilayer film (Y2) having an average thickness of 10 μm / 20 μm / 10 μm / 30 μm and a total thickness of 70 μm was obtained by coextrusion. An unstretched polyethylene terephthalate sheet having a total thickness of 250 μm (product name “Novaclear”, manufactured by Mitsubishi Chemical Corporation) is bonded to the outermost layer side (EVOH surface) of the multilayer film (Y2) by a dry lamination method. A laminate sheet (Y2LS) having a thickness of 320 μm was obtained and used as a bottom material of the package.
In addition, the grade similar to the case where a laminate film (Y1LS) is produced was used as an adhesive for dry lamination.

[Deep-drawn packaging]
A deep drawn package was produced in the same manner as in Example 1 except that the heat seal temperature was changed to 180 ° C. The results of evaluation using this deep-drawn package are shown in Table 1.

Example 6:
[Cover material]
(A1) / (A2) / (A3) / (B) / (C) / (D in the same manner as in Example 1 except that the resin used for the heat seal resin layer (D) was changed to LLDPE. ), A multilayer film (X6) having an average thickness of 10 μm / 10 μm / 10 μm / 10 μm / 10 μm / 20 μm and a total thickness of 70 μm was obtained.

  Next, holes having a hole diameter of 0.1 mm and a depth of 30 μm are opened with a mechanical needle at intervals of 10 mm × 10 mm on the innermost layer side of the heat-seal resin layer (D) of the obtained multilayer film (X6). Used for wood.

[Bottom material]
As in Example 1, a laminate sheet (Y1LS) was used as the bottom material of the package.
[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

Example 7:
[Cover material]
Resin composition in which the surface resin layer (A) has a two-layer structure using A1: 6Ny and A2: 6-66Ny, and 10 parts by weight of “AD1” and 90 parts by weight of “LLDPE” are mixed as the adhesive resin layer (E). (A1) / (A2) / (B) / (C) in the same manner as in Example 1 except that the product was disposed between the pinhole-resistant resin layer (C) and the heat seal resin layer (D). / (E) / (D), a multilayer film (X7) having an average thickness of each layer of 10 μm / 10 μm / 10 μm / 10 μm / 5 μm / 20 μm and a total thickness of 65 μm is obtained and packaged. Used as a body lid.
[Bottom material]
As in Example 1, a laminate sheet (Y1LS) was used as the bottom material of the package.
[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

Comparative Example 1:
[Cover material]
In Example 1, the release resin layer (C) was not disposed, and the average thickness of each layer was 10 μm / each with a five-layer configuration of (A1) / (A2) / (A3) / (B) / (D). A multilayer film (X8) having a total thickness of 60 μm was obtained in the same manner as in Example 1 except that the thickness was changed to 10 μm / 10 μm / 10 μm / 20 μm. Next, holes having a hole diameter of 0.1 mm and a depth of 20 μm are opened with a mechanical needle at intervals of 10 mm × 10 mm on the innermost layer side of the heat seal resin layer (D) of the obtained multilayer film (X8). Used for wood.
[Bottom material]
As in Example 1, a laminate sheet (Y1LS) was used as the bottom material of the package.
[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

Comparative Example 2:
[Cover material]
In Example 1, (A1) / (A2) / (A3) / (B) / (C) was performed in the same manner as in Example 1 except that the thickness of the pinhole-resistant resin layer (C) was 3 μm. A multilayer film (X9) having an average thickness of 10 μm / 10 μm / 10 μm / 10 μm / 3 μm / 20 μm and a total layer thickness of 63 μm was obtained.
Next, holes having a diameter of 0.1 mm and a depth of 20 μm are opened with a mechanical needle at intervals of 10 mm × 10 mm on the innermost layer side of the heat seal resin layer (D) of the obtained multilayer film (X9). Used for wood.
[Bottom material]
As in Example 1, a laminate sheet (Y1LS) was used as the bottom material of the package.
[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

Comparative Example 3:
[Cover material]
In Example 7, the adhesive resin layer (E) was changed to a resin composition in which 90 parts by weight of “AD1” and 10 parts by weight of “LLDPE” were mixed, in the same manner as in Example 7 (A1) / (A2) / (B) / (C) / (E) / (D), the average thickness of each layer is 10 μm / 10 μm / 10 μm / 10 μm / 5 μm / 20 μm, the thickness of all layers Of 65 μm was obtained and used as a lid for the package.
[Bottom material]
As in Example 1, a laminate sheet (Y1LS) was used as the bottom material of the package.
[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

Comparative Example 4:
In Example 1, except that the heat-sealable resin layer (D) was changed to high-density polyethylene (manufactured by Nippon Polyethylene Co., Ltd., trade name “NOVATEC HD HF560”, hereinafter abbreviated as “HDPE”). In the same manner as in Example 1, the average thickness of each layer was 10 μm / 10 μm / 10 μm / 10 μm in a 6-layer configuration of (A1) / (A2) / (A3) / (B) / (C) / (D). A multilayer film (X11) having a thickness of / 10 μm / 20 μm and a total layer thickness of 70 μm was obtained and used as a lid for the package.
[Bottom material]
As in Example 1, a laminate sheet (Y1LS) was used as the bottom material of the package.
[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

Comparative Example 5:
In Example 1, (A1) / (A2) / (A3) / (B) / (C) was carried out in the same manner as in Example 1 except that the thickness of the oxygen barrier resin layer (B) was changed to 2 μm. / (D), a multilayer film (X12) having an average thickness of each layer of 10 μm / 2 μm / 10 μm / 10 μm / 10 μm / 20 μm and a total thickness of 62 μm is obtained. Used for.
[Bottom material]
As in Example 1, a laminate sheet (Y1LS) was used as the bottom material of the package.
[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

Comparative Example 6:
In Example 1, (A1) / (A2) / (A3) / (B) / (C) / in the same manner as in Example 1 except that the thickness of the heat seal resin layer (D) was changed to 5 μm. A multilayer film (X13) having an average thickness of each layer of 10 μm / 10 μm / 10 μm / 10 μm / 10 μm / 5 μm and a total layer thickness of 55 μm is obtained with the 6-layer configuration of (D), and is used as a lid for the package used.
[Bottom material]
As in Example 1, a laminate sheet (Y1LS) was used as the bottom material of the package.
[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

(Reference example)
In Example 1, the oxygen barrier resin layer (B) was saponified with an ethylene-vinyl acetate copolymer (manufactured by Kuraray Co., Ltd., trade name “EVAL G156B”, ethylene copolymerization ratio 48 mol, oxygen permeability: 3.2). (A1) / (A2) / (A3) / (B) / (C) In the same manner as in Example 1, except that (cc · 20 μm / m2 · 24h · atm), hereinafter referred to as “EVOH2”) A multilayer film (X15) having an average thickness of each layer of 10 μm / 5 μm / 10 μm / 10 μm / 10 μm / 20 μm and a total layer thickness of 65 μm is obtained. Used for.
[Bottom material]
As in Example 1, a laminate sheet (Y1LS) was used as the bottom material of the package.
[Deep-drawn packaging]
A deep-drawn package was produced in the same manner as in Example 1. The results of evaluation using this deep-drawn package are shown in Table 1.

  From Table 1, the packaging body (deep-drawing packaging body) having a delamination property and a breathability formed by the lid material using the film defined in the present invention has a peel strength, an oxygen barrier property, a delamination property, and a raw meat. It was confirmed that there was no problem in all the characteristics of the color development state and the practicality was excellent (Examples 1 to 7). On the other hand, when the pinhole-resistant resin layer (C) is not provided or the multilayer film with the pinhole-resistant resin layer (C) having a thickness of 3 μm, the hole formed by perforation has an oxygen barrier. As a result, the oxygen barrier property was lowered, the raw meat color gradually changed from purple to black, and the storage period was short (Comparative Example 1 and Comparative Example 2).

  When a resin composition in which 90 parts by mass of adhesive resin and 10 parts by mass of LLDPE are mixed as the adhesive resin layer (E) is disposed between the oxygen barrier resin layer (B) and the pinhole-resistant resin (C). The adhesive strength was too strong at 5.0 N / 15 mm width and was difficult to open (Comparative Example 3).

  When HDPE was disposed on the heat-seal resin layer (D), it took several days to develop the raw meat after delamination (Comparative Example 4).

  When the oxygen barrier resin layer (B) is 2 μm, or when an ethylene-vinyl acetate copolymer saponified product having an ethylene copolymerization ratio of 48 mol is used, raw meat is produced at an earlier stage than the storage period of 21 days. The color changed from purple to black-red (Comparative Example 5, Reference Example).

  When the thickness of the heat seal resin layer (D) was 5 μm, the film of the heat seal resin layer (D) was broken at the frame seal portion on the bottom material side of the object to be sealed after delamination. (Comparative Example 6)

  The packaging material of the present invention can be suitably used for packaging raw edible meat such as beef, chicken and pork.

DESCRIPTION OF SYMBOLS 1 Lid material 2 Bottom material 3 Lid surface resin layer 4 Lid oxygen barrier resin layer 5 Lid pinhole-resistant resin layer 6 Lid heat seal resin layer 7 Lim surface resin layer 8 Bottom material Heat seal resin layer 9 Heat seal part 10 of bottom material Tab part 11 of cover material Exposed part 12 of pinhole-resistant resin layer at the time of peeling Exposed part of heat seal resin layer at the time of peeling

Claims (12)

The surface resin layer (A), oxygen barrier resin layer (B), pinhole resistant resin layer (C), and heat seal resin layer (D) are (A) / (B) / (C) / (D). A multilayer film composed of layers having a peel strength of 0.05 to 5.0 N / 15 mm width laminated in order and having a peel strength of the oxygen barrier resin layer (B) and the pinhole-resistant resin layer (C) is used as a lid. A heat sealed resin layer (D) of the multilayer film is heat-sealed to the sealed portion of the object to be sealed, and the bottom material and the lid material are heat sealed. The resin layer (C) and the heat seal resin layer (D) are delaminated, the surface resin layer (A), the oxygen barrier resin layer (B), and the pinhole-resistant resin layer (C) are removed, and the sealed The thin film layer of the heat seal resin layer (D) is exposed and left on the body. Package. The package according to claim 1, wherein the oxygen permeability of the heat seal layer (D) is 25,000 cc / (m ² · 24 h · atm) or more in an environment of 23 ° C and 50% RH. The surface resin layer (A), the oxygen barrier resin layer (B), and the pinhole resistant resin layer (C) are not perforated, and only the heat seal resin layer (D) is perforated. 2. The package according to 2. The interlayer adhesion strength between the surface resin layer (A) and the oxygen barrier resin layer (B) and the interlayer adhesion strength between the oxygen barrier resin layer (B) and the pinhole resistant resin layer (C) are pinhole resistant resins. The package according to any one of claims 1 to 3, wherein the packaging body is larger than the peel strength between the layer (C) and the heat seal resin layer (D). The surface resin layer (A) is at least one thermoplastic selected from the group consisting of olefin resins, amide resins, saponified ethylene-vinyl acetate copolymers, ester resins, styrene resins, and carbonate resins. The package body in any one of Claims 1-4 which has resin as a main component. The oxygen barrier resin (B) is selected from the group consisting of a saponified ethylene-vinyl acetate copolymer and a polymetaxylene adipamide resin, and its oxygen permeability is 3 (23 ° C., 50% RH environment). The package according to any one of claims 1 to 5, comprising a resin of cc · 20 µm / m ² · 24h · atm) or less as a main component. The pinhole-resistant resin (C) is mainly composed of one type of thermoplastic resin selected from the group consisting of amide resins, ester resins, polypropylene resins, and cyclic polyolefin resins. The package in any one. The heat seal resin layer (D) is an ethylene resin, a propylene resin, an ethylene-vinyl acetate copolymer, an ethylene-methyl acrylate copolymer, an ethylene-ethyl acrylate copolymer, an ethylene-metal methacrylate copolymer, The main component is at least one thermoplastic resin selected from the group consisting of an ethylene-acrylic acid copolymer, an ethylene-methacrylic acid copolymer, an ionomer, and 4-methyl-1-pentene. The package in any one of. An adhesive resin layer (E) is provided between the oxygen barrier resin layer (B) and the pinhole resistant resin layer (C), and the oxygen barrier resin layer (B) and the adhesive resin layer (E) The package according to any one of claims 1 to 8, comprising a layer having a peel strength of 0.05 to 5.0 N / 15 mm. The package according to any one of claims 1 to 9, wherein the oxygen barrier resin layer (B) has a thickness of 3 to 100 µm. The package according to any one of claims 1 to 10, wherein the pinhole-resistant resin layer (C) has a thickness of 5 to 100 µm. The package according to any one of claims 1 to 11, wherein the heat seal resin layer (D) has a thickness of 5 to 100 µm.

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