JP2018100115A - Deep drawing molded packaging body for food packaging - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-layered film for food packaging which, as a lid body of deep drawing molded package, can suppress curling on the flange part after heat sealed with the bottom material.SOLUTION: A deep drawing molded packaging body is prepared by combining: a lid material made from a first multi-layered film; and a bottom material which has a flange part capable of being heat sealed with a recess part that is made from a second multi-layered film and for containing the objects to be packed and the lid material. The first multi-layered film, while having an oxygen permeability of 150 ml/m/d/MPa or less, includes in order a first outermost layer containing non-stretched polypropylene resin layers, a first middle layer containing biaxial orientation polyester-based resin layers and a barrier film, and a first sealant layer containing non-stretched olefin-based resin layers. The average thickness of the first outermost layer is 5-35 μm and the average thickness of the first sealant layer is 10-40 μm. The second multi-layered film includes in order a second outermost layer containing non-stretched polyester-based resin layers, a second barrier layer and a second sealant layer.SELECTED DRAWING: None

Description

  The present invention relates to a deep-drawn molded package for food packaging used for packaging foods such as sliced ham and bacon.

  For the packaging of processed meat products such as ham, sausage, bacon, grilled pork and chicken, deep-drawn packaging with a heat-sealed lid and bottom is widely used. In deep-drawn packaging, the bottom material generally requires thermoforming, so an unstretched multilayer film produced by coextrusion is used. In addition, since the lid material generally requires printing processing, and it is necessary to set a printing layer between layers, a multilayer film in which each film is laminated is used. If the bottom material is not used for boiling, polyethylene terephthalate (PET), which is relatively rigid, is generally used for the outermost layer. On the other hand, since the lid material needs to balance heat shrinkage in order to suppress the curling after heat-sealing with the bottom material that has been heat-molded and the bottom material that has been thermoformed, the outermost layer is biaxially oriented polypropylene (OPP) A multilayer film having an OPP / PET / LLDPE structure in which a sealant layer is formed of linear low density polyethylene (LLDPE) has been widely used. However, even OPP / PET / LLDPE has a large curl to the LLDPE side (bottom material side), and troubles may occur due to catching on the conveyor line, printing, labels, and the like, which may reduce productivity. In particular, in recent years, packaging forms that contain thin contents such as sliced ham and bacon have been increasingly commercialized as continuous packs in which a plurality of packs are connected by a label. Troubles due to the lack of each pack are increasing, and the demand for curl suppression is further increasing.

  Regarding a lid for deep-drawn packaging, Japanese Patent Application Laid-Open No. 2002-205769 (Patent Document 1) discloses an outer surface layer having excellent dimensional stability and gas barrier properties as a blister package for housing slice ham and slice bacon. The lid material formed of a laminate composed of an excellent intermediate layer and an easily peelable inner surface layer and the container material on which the content container is formed are hermetically sealed so as to be peelable at the peripheral heat-bonding portion. A blister pack is disclosed. As the intermediate layer of the lid member, ethylene-vinyl alcohol copolymer (EVOH), VMPET, and vinylidene chloride coated cellophane (KM) are described. Specific lid materials include PET / printing / dry lamination (DL) / ethylene vinyl acetate copolymer (EVA) / EVOH / EVA (coextruded film), vinylidene chloride coated biaxially oriented polypropylene (KOP) / Printing / DL / PET / EVA, CPP / DL / VMPET / Printing / LLDPE, Biaxially oriented polypropylene (OPP) / DL / VMPET / Printing / EVA, CPP / DL / KM / Printing / EVA, OPP / DL / KM / Printing / EVA is described. In addition, as a specific container material, a coextruded film made of unstretched nylon (CNy) / EVOH / ethylene-vinyl acetate copolymer (EVA) is generally used. Furthermore, a film in which unstretched polypropylene or amorphous polyester is laminated is also described.

  In JP 2005-289403 A (Patent Document 2), in deep-drawn packaging, at least the bottom material is laminated in the order of PP / EVOH / Ny / seal layer or PP / Ny / EVOH / seal layer in a thickness of 50 to A 300 μm film is used, and at least PP / [[biaxially stretched 6Ny / MXDNy / 6Ny] // sealing layer or PP // [biaxially stretched 6Ny / EVOH / 6Ny] // sealing layer is laminated on the lid. Furthermore, the shrinkage ratio in hot water of 95 ° C. × 5 minutes of [biaxial stretching 6Ny / MXDNy / 6Ny] or [biaxial stretching 6Ny / EVOH / 6Ny] is 1 to 3%. A deep drawn package characterized by being packaged using a certain film is disclosed. In Comparative Example 2 of this document, a lid formed of PP // [transparent vapor-deposited PET] // LLDPE, and a bottom formed of PP / AD (adhesive resin) / EVOH / Ny / AD / LLDPE However, curls in which the average value of curls at the four corners of the flange portion exceeds 10 mm are generated.

  However, even the packaging bodies of Patent Documents 1 and 2 cannot suppress curling after heat sealing, and cannot improve productivity in continuous pack products such as sliced ham and bacon.

JP 2002-205769 A (Claim 1, paragraphs [0002] [0018] [0019] [0020]) JP-A-2005-289403 (Claim 1, Example)

  Accordingly, an object of the present invention is to provide a deep-drawn package for food packaging that can suppress the occurrence of curling in the flange portion even after heat sealing.

  Still another object of the present invention is to provide a deep-drawn package for food packaging that has excellent oxygen barrier properties, is transparent, can confirm contents, and has excellent printability.

As a result of intensive studies to achieve the above-mentioned problems, the present inventors have found that a first outermost layer including an unstretched polypropylene resin layer and having an average thickness of 5 to 35 μm, a biaxially stretched polyester resin layer, and a barrier film Including an unstretched olefin-based resin layer and a first sealant layer having an average thickness of 10 to 40 μm in this order, and having an oxygen permeability of 150 ml / m ² · d · MPa or less. A second multilayer including a lid formed of the first multilayer film, a second outermost layer including an unstretched polyester resin layer, a second barrier layer, and a second sealant layer in this order. It was found that curling in the flange portion can be suppressed even after heat sealing by combining with a bottom material formed of a film, and the present invention has been completed.

That is, the deep-drawn molded package of the present invention includes a lid formed with a first multilayer film, a recess formed with a second multilayer film, and a lid for accommodating an article to be packaged, and the lid and heat. A deep-drawn package including a bottom member having a sealable flange portion, wherein the first multilayer film has an oxygen permeability of 150 ml / m ² · d · MPa or less and unstretched polypropylene A first outermost layer including a resin-based resin layer, a first intermediate layer including a biaxially stretched polyester-based resin layer and a barrier film (gas barrier film), and a first sealant layer including an unstretched olefin-based resin layer In this order, the average thickness of the first outermost layer is 5 to 35 μm, the average thickness of the first sealant layer is 10 to 40 μm, and the second multilayer film is an unstretched polyester Tree A second outermost layer comprising a layer, the second barrier layer (gas barrier layer), and a second sealant layer in this order. The barrier film included in the first intermediate layer may be an inorganic barrier film. The heat bonding temperature of the unstretched polypropylene resin layer contained in the first outermost layer may be 135 ° C. or higher. The unstretched olefin resin layer contained in the first sealant layer may contain linear low density polyethylene. The deep-drawn molded package of the present invention may further include a second intermediate layer including a polyamide-based resin layer between the second outermost layer and the second sealant layer. The average thickness of the first intermediate layer is about 7 to 25 μm. The ratio of the average depth of the recess to the average diameter of the recess is about average diameter / average depth = 5/1 to 50/1. The deep-drawn molded package of the present invention may be a deep-drawn molded package for accommodating thin-walled foods such as sliced ham and bacon.

In the present invention, a first outermost layer including an unstretched polypropylene resin layer and having an average thickness of 5 to 35 μm, a first intermediate layer including a biaxially stretched polyester resin layer and a barrier film, and an unstretched olefin system A lid material including a resin layer, a first sealant layer having an average thickness of 10 to 40 μm in this order, and formed of a first multilayer film having an oxygen permeability of 150 ml / m ² · d · MPa or less; Since the second outermost layer including the stretched polyester-based resin layer, the second barrier layer, and the bottom material formed of the second multilayer film including the second sealant layer in this order are combined, Even after heat sealing, the occurrence of curling in the flange portion can be suppressed. Therefore, the productivity of thin-packed food products such as sliced ham and bacon can be improved. Furthermore, it has excellent oxygen barrier properties, is transparent and can confirm contents, and has excellent printability.

  A deep-drawn package of the present invention includes a lid formed from a first multilayer film, a recess formed from a second multilayer film, and a flange for containing food, and a flange that can be heat-sealed with the lid. It is the package which combined the bottom material which has a part.

[Cover material]
The lid member is formed of a first multilayer film into a film shape. The planar shape of the film can be appropriately selected according to the type of food to be stored, and may be a circular shape, a square shape, or the like. The average thickness of the lid material (first multilayer film) is, for example, about 30 to 100 μm, preferably 40 to 80 μm, and more preferably about 50 to 70 μm (particularly 55 to 65 μm). If the average thickness of the first multilayer film is too thin, there is a risk that the feeling of lowering may be reduced, and if it is too thick, the flexibility may be reduced and the economy may be reduced. The first multilayer film includes a first outermost layer, a first intermediate layer, and a first sealant layer in this order.

(First outermost layer)
The first multilayer film includes a first outermost layer, and the first outermost layer includes an unstretched polypropylene-based resin layer. In the present invention, by arranging a layer containing an unstretched polypropylene resin layer as the first outermost layer, printing (gravure printing or the like) is performed on the back surface of the first intermediate layer viewed from the viewing side (bottom material side). And a clear print image (for example, a multicolor print image) can be formed.

  The polypropylene resin constituting the unstretched polypropylene resin layer may be a propylene homopolymer (propylene homopolymer) or a propylene copolymer (propylene copolymer).

In the copolymer, as a monomer copolymerizable with propylene (copolymerizable monomer), for example, α-olefin (ethylene, 1-butene, 1-pentene, 1-hexene, 2-methyl-1-pentene, 3-methyl) -1-pentene, 4-methyl-1-pentene, 4,4-dimethyl-1-pentene, 3-ethyl-1-pentene, 3-methyl-1-butene, 4-methyl-1-hexene, 4,4 -Dimethyl-1-hexene, 3-ethyl-1-hexene, 4-ethyl-1-hexene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene , 1-octadecene, _{1-alpha-C 2-20} olefins, such as eicosene), alkadiene (1,4-hexadiene, 1,7-octadiene, 4-methyl - , 4-hexadiene, non-conjugated alkadienes such as 5-methyl-1,4-hexadiene, conjugated alkadienes such as butadiene and isoprene), ethylenically unsaturated carboxylic acids and their acid anhydrides [(meth) acrylic acid, maleic acid , Fumaric acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, mesaconic acid, angelic acid, etc.], (meth) acrylic acid esters [(meth) acrylic acid alkyl esters, glycidyl (meth) acrylates, etc.), vinyl carboxylate Examples thereof include esters (saturated carboxylic acid vinyl esters such as vinyl acetate and vinyl propionate). These monomers can be used alone or in combination of two or more. Among these monomers, α-C _2-6 olefins such as ethylene and 1-butene are widely used.

  Examples of the form of the copolymer include block copolymerization, random copolymerization, alternating copolymerization, and graft copolymerization. Of these, usually random copolymerization and alternating copolymerization.

  In the polypropylene resin, the ratio (molar ratio) of propylene (propylene unit) and copolymerizable monomer (copolymerizable monomer unit) is propylene / copolymerizable monomer = 90/10 to 100/0, preferably 95 / It is 5-100 / 0, More preferably, it is about 99 / 1-100 / 0.

  The polypropylene resin may be an atactic polymer, but a structure having stereoregularity such as isotactic or syndiotactic is preferable from the viewpoint of improving heat resistance, and an isotactic polymer is particularly preferable.

  Further, the polypropylene resin may be a polymer using a Ziegler catalyst, but a metallocene resin using a metallocene catalyst from the viewpoint of obtaining a polymer having a low molecular weight tack component and a narrow molecular weight distribution. Is preferred.

  The number average molecular weight of the polypropylene resin is, for example, about 10,000 to 500,000, preferably about 15,000 to 300,000, and more preferably about 20,000 to 100,000. In the present specification and claims, the number-average molecular weight of the polypropylene-based resin is determined by the GPC method using a measurement temperature of 140 ° C., ortho-dichlorobenzene as a solvent, and a column (Shodex GPC AD-806MS). It is a value measured by universal calibration based on polystyrene.

  The melting point (or softening point) of the polypropylene resin is preferably higher than the melting point of the olefin resin contained in the first sealant layer, and can be selected from a range of about 120 to 180 ° C., for example, and can improve transparency. To 130 ° C. or higher (especially 135 ° C. or higher), for example, 130 to 175 ° C. (eg 135 to 170 ° C.), more preferably 150 to 165 ° C. (especially 155 to 160 ° C.). In the present specification and claims, the melting point of the polypropylene resin can be measured based on the melting peak temperature with a differential scanning calorimeter DSC. Moreover, the heat bonding temperature of a polypropylene resin layer can also be selected from the range of melting | fusing point (or softening point) of these polypropylene resins. The heat-bonding temperature of the polypropylene resin layer can be measured as a heat seal temperature that reaches 2N strength by stepping on a heater bar with two 15 mm wide strip-shaped samples sandwiched between cellophanes from the outside.

  In addition to the polypropylene resin, the unstretched polypropylene resin layer is made of other thermoplastic resins (olefin resins such as polyethylene resins, chlorine-containing resins, styrene resins, petroleum resins, etc.) and conventional additives (for example, heat Stabilizers, antioxidants, UV absorbers, preservatives, bactericides, plasticizers, lubricants, colorants, viscosity modifiers, leveling agents, surfactants, antistatic agents, etc.) Also good. The total proportion of the other thermoplastic resins and additives is 50 parts by weight or less, preferably 30 parts by weight or less (for example, 0.01 to 30 parts by weight), more preferably 10 parts by weight with respect to 100 parts by weight of the polypropylene resin. It is about the following (for example, 0.1 to 10 parts by weight).

  The tensile strength of the first unstretched polypropylene-based resin layer is, for example, less than 100 MPa, preferably 10 to 90 MPa, and more preferably 20 to 80 MPa (particularly 30 to 70 MPa) by a method based on JIS K7161.

  The first outermost layer may include other resin layers in addition to the unstretched polypropylene resin layer, but is usually formed of the unstretched polypropylene resin layer alone.

  The average thickness of the first outermost layer is 5 to 35 μm (especially 8 to 35 μm), preferably 10 to 32 μm (for example 12 to 30 μm), more preferably 15 to 25 μm (particularly 18 to 23 μm). If the average thickness of the first outermost layer is too thick, the thermal shrinkage balance is deteriorated, the curl suppressing effect is lowered, and there is a risk of curling to the lid material side (first outermost layer side), and the economy is also high. If it is too thin, there is a risk that the feeling of low back of the film will decrease.

  In the present specification and claims, the average thickness is measured using five dial gauges at any 10 points on the film according to JIS K7130 (1992) A-2 method. It can be calculated by dividing the average value of 5 sheets by 10.

(First intermediate layer)
The first multilayer film further includes a first intermediate layer, and the first intermediate layer includes a biaxially stretched polyester resin layer and a barrier film. In the present invention, since the first intermediate layer includes the biaxially stretched polyester resin layer and the barrier film, curling due to heat treatment can be suppressed, and the first multilayer film can also be provided with a low feeling and gas barrier properties.

(A) Biaxially stretched polyester resin layer As the polyester resin constituting the biaxially stretched polyester resin layer, a polyalkylene arylate resin is preferable. The polyalkylene arylate resin has, as a main component, an alkylene arylate unit, for example, at a ratio of 50 mol% or more, preferably 75 to 100 mol%, more preferably 80 to 100 mol% (particularly 90 to 100 mol%). Containing homo or copolyesters are included. The copolymerizable monomer constituting the copolyester includes a dicarboxylic acid component (for example, C _8-20 aromatic dicarboxylic acid such as terephthalic acid, isophthalic acid, 2,7-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid). Acid, adipic acid, azelaic acid, C _4-12 alkane dicarboxylic acid such as sebacic acid, C _4-12 cycloalkane dicarboxylic acid such as 1,4-cyclohexanedicarboxylic acid, etc.), diol component (for example, ethylene glycol, propylene glycol) , butanediol, _{C 2-10} alkanediol such as neopentyl glycol, diethylene glycol, _{C 4-12} cycloalkane diols such as poly _{C 2-4} alkylene glycol, 1,4-cyclohexanedimethanol, such as polyethylene glycol, bisphenol And aromatic diols such as), hydroxycarboxylic acid component (e.g., p- hydroxybenzoic acid, p- hydroxyethoxy benzoic acid) and the like. These copolymerizable monomers can be used alone or in combination of two or more. Examples of the polyalkylene arylate resin include poly _C2-4 alkylene terephthalate resins such as polyethylene terephthalate, polytrimethylene terephthalate, and polybutylene terephthalate, and polyalkylene terephthalate resins such as polyethylene naphthalate, polytrimethylene naphthalate, and polybutylene naphthalate. C _2-4 alkylene naphthalate resin and the like can be mentioned.

  In the present invention, among these polyalkylene arylate resins, polyethylene arylate resins such as polyethylene terephthalate and polyethylene naphthalate, in particular, homopolyesters of ethylene arylate units, or ethylene arylates from the viewpoint of high dimensional stability after stretching. A copolyester having a unit content of 80 mol% or more (particularly 90 mol% or more) may be mentioned. Examples of the copolymerizable monomer constituting the copolyester include the aforementioned dicarboxylic acid component, diol component, and hydroxycarboxylic acid.

  The number average molecular weight of the polyester resin can be selected from a range of about 5000 to 1000000 in terms of polystyrene using GPC (gel permeation chromatography), for example, 10000 to 500000, preferably 12000 to 300000, and more preferably 15000 to 100000. Degree.

  The biaxially stretched polyester resin layer may also contain other thermoplastic resins and polypropylene resins exemplified in the section of the first outermost layer and conventional additives, in addition to the polyester resin. The total ratio of other thermoplastic resins and additives is the same as that of the unstretched polypropylene resin layer in the first outermost layer.

  The tensile strength of the biaxially stretched polyester resin layer is, for example, 100 MPa or more, preferably 100 to 500 MPa, more preferably 150 to 400 MPa (particularly 200 to 300 MPa), according to a method based on JIS K7127.

  In the biaxially stretched polyester resin layer, the draw ratio in the film take-up direction (MD direction) and the width direction (TD direction) may be 1.5 times or more (for example, 1.5 to 10 times), For example, it is 2 to 8 times, preferably 2 to 5 times, more preferably about 3 to 4 times. If the stretch ratio is too large, it may be difficult to produce the stretched film itself, and if it is too small, the film may have a low back feeling.

  The biaxially stretched polyester resin layer (particularly, the surface not in contact with the barrier film) may be subjected to surface treatment (for example, corona discharge treatment, flame treatment, plasma treatment, ozone or ultraviolet irradiation treatment) An adhesive layer may be provided.

(B) Barrier film (gas barrier film)
The barrier film may be an inorganic barrier film or an organic barrier film, and can be appropriately selected depending on the application. For applications that require a balance between curl prevention and oxygen barrier properties, inorganic barrier films may be used, and it is necessary to prevent deterioration of oxygen barrier properties due to cracks in the barrier film due to damage during packaging or transport. In some applications, an organic barrier film may be used. Among these, an inorganic barrier film is preferable from the viewpoint that a high oxygen barrier property can be realized.

(B1) Inorganic barrier film The inorganic barrier film usually contains a metal or a metal compound, and is preferably composed of a metal or a metal compound capable of forming a thin film (in particular, a transparent thin film). Examples of such metals include group 2A elements of the periodic table such as beryllium, magnesium, calcium, strontium, and barium; transition elements such as titanium, zirconium, ruthenium, hafnium, tantalum, and copper; and group 2B elements of the periodic table such as zinc. Examples include periodic table group 3B elements such as aluminum, gallium, indium and thallium; periodic table group 4B elements such as silicon, germanium and tin; and periodic table group 6B elements such as selenium and tellurium. Examples of the metal compound include the metal oxides, nitrides, oxynitrides, halides, and carbides. These metals or metal compounds can be used alone or in combination of two or more.

  Among these metals or metal compounds, since not only gas barrier properties but also transparency can be improved, periodic table 3B elements such as aluminum, periodic table 4B elements such as silicon, metal oxides of transition elements such as titanium, Metal oxynitrides and metal nitrides are preferable, and aluminum oxide [compositional formula AlxOy (x, y> 0)] and silicon oxide are particularly preferable.

  The inorganic barrier film can be formed using a conventional film forming method capable of forming a thin film containing a metal or a metal compound. Examples of the film formation method include physical vapor deposition (PVD) [for example, vacuum deposition, flash deposition, electron beam deposition, ion beam deposition, ion plating (for example, HCD, electron beam RF). Method, arc discharge method, etc.), sputtering method (eg, DC discharge method, radio frequency (RF) discharge method, magnetron method, etc.), molecular beam epitaxy method, laser ablation method, etc.], chemical vapor phase method (CVD) [eg, , Thermal CVD method, plasma CVD method, MOCVD method (metal organic chemical vapor deposition method), photo CVD method, etc.], ion beam mixing method, ion implantation method and the like. Among these film forming methods, a physical vapor phase method such as a vacuum vapor deposition method, an ion plating method, a sputtering method, a chemical vapor phase method and the like are widely used, and the vacuum vapor deposition method is preferable.

  The average thickness of the inorganic barrier film can be appropriately selected according to the film forming method, and may be, for example, about 10 to 300 nm, preferably 15 to 250 nm, more preferably about 20 to 200 nm (particularly 30 to 100 nm). In particular, the average thickness of the inorganic barrier film is about 10 to 100 nm (especially 15 to 80 nm) in the physical vapor phase method from the viewpoint of preventing the occurrence of cracks and the like and maintaining the gas barrier property by forming a uniform film. In the chemical vapor phase method, the thickness of the inorganic barrier film is preferably adjusted to about 50 to 400 nm (particularly 100 to 300 nm). If the thickness of the inorganic barrier film with respect to the biaxially stretched polyester resin layer is too thin, the oxygen barrier property may be lowered, and if it is too thick, the flexibility may be lowered.

(B2) Organic barrier film Examples of the organic barrier resin constituting the organic barrier film include vinylidene chloride resins, vinyl alcohol resins (such as polyvinyl alcohol and ethylene-vinyl alcohol copolymers), Examples thereof include saccharides (water-soluble cellulose derivatives, water-soluble starch, chitosan, etc.). These organic barrier resins can be used alone or in combination of two or more. Of these organic-based barrier resins, vinylidene chloride-based resins are preferred because they can suppress a decrease in oxygen barrier properties due to moisture and moisture.

  The vinylidene chloride-based resin may be a vinylidene chloride homopolymer (vinylidene chloride homopolymer) or a vinylidene chloride copolymer (vinylidene chloride-based copolymer).

  In the copolymer, monomers (copolymerizable monomers) copolymerizable with vinylidene chloride include, for example, chlorine-containing monomers other than vinylidene chloride such as vinyl chloride; vinyl ester monomers such as vinyl acetate and vinyl propionate; butadiene and isoprene Diene monomers such as; (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, mesaconic acid, angelic acid, and other ethylenically unsaturated carboxylic acids; methyl (meth) acrylate (Meth) acrylic acid esters such as (meth) acrylic acid alkyl ester, (meth) acrylic acid alkyl ester, (meth) acrylic acid hydroxyalkyl ester, glycidyl (meth) acrylate, etc .; (meth) acrylonitrile Such as Etc. Ann vinylic monomers. These copolymerizable monomers can be used alone or in combination of two or more. Among the copolymerizable monomers, vinyl chloride, vinyl acetate, (meth) acrylic acid, (meth) acrylic acid alkyl ester, (meth) acrylic acid hydroxyalkyl ester, glycidyl (meth) acrylate, (meth) acrylonitrile, etc. are widely used. Vinyl chloride is preferred.

  Examples of the form of the copolymer include block copolymerization, random copolymerization, alternating copolymerization, and graft copolymerization. Of these, usually random copolymerization and alternating copolymerization.

  In the vinylidene chloride resin, the ratio (molar ratio) between vinylidene chloride (vinylidene chloride unit) and copolymerizable monomer (copolymerizable monomer unit) is vinylidene chloride / copolymerizable monomer (particularly vinyl chloride) = 99 / 1-5 / 95, preferably 97/3 to 10/90, more preferably about 95/5 to 50/50. If the proportion of vinylidene chloride is too small, the handleability (solvent solubility) may be reduced, and if it is too high, the oxygen barrier property may be reduced.

  The number average molecular weight of the vinylidene chloride resin is, for example, 10,000 to 500,000, preferably 20,000 to 250,000, more preferably 25,000 to 100 in terms of polystyrene in gel permeation chromatography (GPC). It may be about 1,000.

  In addition to organic barrier resin (especially vinylidene chloride resin), the organic barrier film includes reactive adhesive components [isocyanate compounds (tolylene diisocyanate, xylylene diisocyanate, tetramethyl xylylene diisocyanate, diphenylmethane-4, Aromatic isocyanates such as 4′-diisocyanate and derivatives thereof, and imino group-containing polymers (polyethyleneimine and the like)].

  The proportion of the reactive adhesive component is 30 parts by weight or less (for example, 0.1 to 30 parts by weight), preferably 0.5 to 20 parts by weight, more preferably 1 to 10 parts by weight with respect to 100 parts by weight of the vinylidene chloride resin. It may be about a part.

  In addition to vinylidene chloride resins and reactive adhesive components, organic barrier films are made of other thermoplastic resins (olefin resins such as polyethylene resins, other chlorine-containing resins, styrene resins, petroleum resins, etc.), unstretched Conventional additives exemplified in the section of the polypropylene resin layer may be included. The total ratio of the other thermoplastic resins and additives is 50 parts by weight or less, preferably 30 parts by weight or less (for example, 0.01 to 30 parts by weight), more preferably 10 parts by weight with respect to 100 parts by weight of the vinylidene chloride resin. Part or less (for example, 0.1 to 10 parts by weight).

  The average thickness of the organic barrier film is, for example, about 3 to 20 μm, preferably 4 to 15 μm, and more preferably about 5 to 10 μm (particularly 6 to 8 μm).

  The average thickness ratio of the biaxially stretched polyester resin layer and the organic barrier film (when each layer is a plurality of layers) is, for example, biaxially stretched polyester resin layer / organic barrier film = 42 / It is 1 to 2/1, preferably 36/1 to 5/1, more preferably about 26/1 to 7/1 (especially 20/1 to 9/1). If the thickness of the organic barrier film with respect to the biaxially stretched polyester resin layer is too thin, the oxygen barrier property may be lowered, and if it is too thick, the economic efficiency is lowered.

(C) Characteristics of the first intermediate layer The first intermediate layer may contain other resin layers in addition to the biaxially stretched polyester resin layer and the barrier film. This is a combination of a resin layer and a barrier film.

  When combining a biaxially stretched polyester resin layer and an organic barrier film, a barrier film may be laminated on both sides of the biaxially stretched polyester resin layer, or a biaxially stretched polyester resin layer is laminated on both sides of the barrier film. However, an organic barrier film is usually laminated on one surface of the biaxially stretched polyester resin layer. When a barrier film is laminated on one surface of the biaxially stretched polyester resin layer, the barrier film may be laminated on the first outermost layer side or may be laminated on the first sealant layer side. When the barrier film is an inorganic barrier film, the barrier film may be laminated on the first outermost layer side from the viewpoint that the deterioration of the barrier film due to the contents can be suppressed depending on the type of package.

  An adhesive layer may be interposed between the biaxially stretched polyester resin layer and the barrier film, but when the inorganic barrier film is formed by a vapor phase method such as vapor deposition, the organic barrier film When a reactive adhesive component is included, an adhesive layer may not be interposed. A laminated film of a biaxially stretched polyester resin layer and a barrier film without interposing an adhesive layer is a laminated film in which an inorganic barrier film is deposited on at least one surface of the biaxially stretched polyester resin layer (an inorganic barrier film is deposited). Or a laminated film in which at least one surface of the biaxially stretched polyester resin layer is coated with an organic barrier film (a laminated film in which the organic barrier film is a coated film). These laminated films are also available as commercial products.

  The average thickness of the first intermediate layer is, for example, about 7 to 25 μm, preferably about 8 to 20 μm, and more preferably about 10 to 18 μm (particularly 11 to 15 μm). If the average thickness of the first intermediate layer is too thick, the flexibility and economy may be reduced, and if it is too thin, the lumbar feeling of the film may be reduced.

  The average thickness of the first intermediate layer may be 0.3 times or more (particularly 0.4 times or more) with respect to the average thickness of the first outermost layer, for example, 0.3 to 1.5 times, Preferably it is 0.35-1 times, More preferably, it is about 0.4-0.8 times (especially 0.5-0.7 times). If the thickness of the first intermediate layer with respect to the first outermost layer is too thin, there is a risk that the waist feeling will be reduced.

(First sealant layer)
The first multilayer film further includes a first sealant layer, and the first sealant layer includes an unstretched olefin resin layer. In the present invention, since the first sealant layer includes the unstretched olefin resin layer, the first sealant layer has heat sealability and can be heat sealed with the bottom material formed of the second multilayer film.

  The olefin resin constituting the unstretched olefin resin layer is preferably an olefin resin having a lower melting point than the polypropylene resin contained in the unstretched polypropylene resin layer, and may be a polypropylene resin. It is preferable to contain a resin.

  The polyethylene resin may be an ethylene homopolymer (ethylene homopolymer) or an ethylene copolymer (ethylene copolymer).

In the copolymer, as a monomer copolymerizable with ethylene (copolymerizable monomer), for example, propylene, an α-olefin exemplified as a copolymerizable monomer of unstretched polypropylene contained in the first outermost layer (excluding ethylene) ), Alkadienes, ethylenically unsaturated carboxylic acids and acid anhydrides thereof, (meth) acrylic acid esters and carboxylic acid vinyl esters. These copolymerizable monomers can be used alone or in combination of two or more. Among these monomers, α-C _3-10 olefins such as 1-butene, 1-hexane, 1-octene and 4-methyl-1-pentene are widely used, and α-C _4-8 olefins such as 1-butene. Is preferred.

  Examples of the form of the copolymer include block copolymerization, random copolymerization, alternating copolymerization, and graft copolymerization. Of these, usually random copolymerization and alternating copolymerization.

  In the polyethylene resin, the ratio (molar ratio) of ethylene (ethylene unit) and copolymerizable monomer (copolymerizable monomer unit) is ethylene / copolymerizable monomer = 50/50 to 100/0, preferably 60 / It is about 40 to 99/1, more preferably about 65/35 to 95/5 (particularly 70/30 to 90/10). If the ratio of ethylene is too small, moldability and the like may be reduced.

  Examples of the polyethylene resin include low density polyethylene (LDPE), medium density polyethylene, high density polyethylene (HDPE), and linear (linear) low density polyethylene (LLDPE). Among these, LLDPE is preferable from the viewpoint of heat sealability and the like, and may be LLDPE alone. From the viewpoint of adjusting the melting point (heat sealability), LLDPE and other polyolefin resins (particularly other polyethylene resins). ).

  When polyolefin resin contains LLDPE, the weight ratio of LLDPE is 50 weight% or more with respect to the whole polyethylene resin, Preferably it is 80 to 100 weight%, More preferably, it is 90 to 100 weight% or more.

  The number average molecular weight of the olefin resin (particularly polyethylene resin) may be, for example, about 10,000 to 300,000, preferably about 15,000 to 200,000, and more preferably about 20,000 to 100,000. . In the present specification and claims, the number average molecular weight of the polyolefin resin is a value measured under the same conditions as the method for measuring the number average molecular weight of the polypropylene resin contained in the outermost layer.

  The melting point (or softening point) of the olefin resin (especially polyethylene resin) is preferably lower than the melting point of the polypropylene resin contained in the first outermost layer, for example, 80 to 150 ° C., preferably 90 to 140 ° C. More preferably, it is about 100-130 degreeC (especially 110-125 degreeC). In the present specification and claims, the melting point of the olefin resin can be measured based on the melting peak temperature with a differential scanning calorimeter DSC.

  The tensile strength of the unstretched olefin resin layer is, for example, less than 100 MPa, preferably 10 to 90 MPa, and more preferably 20 to 80 MPa (particularly 30 to 70 MPa) in accordance with JIS K7161.

  The unstretched olefin resin layer is a term of other thermoplastic resin (chlorine-containing resin, styrene resin, petroleum resin, etc.), unstretched polypropylene resin layer contained in the first outermost layer, in addition to the olefin resin. The exemplified conventional additives may be included. The total proportion of the other thermoplastic resins and additives is 50 parts by weight or less, preferably 30 parts by weight or less (for example, 0.01 to 30 parts by weight), more preferably 10 parts by weight with respect to 100 parts by weight of the olefin resin. It is about the following (for example, 0.1 to 10 parts by weight).

  The first sealant layer may include other resin layers in addition to the unstretched olefin resin layer, but is usually formed of a nonstretched olefin resin layer alone.

  The average thickness of the first sealant layer is 10 to 40 μm (particularly 10 to 35 μm), preferably 13 to 32 μm, more preferably 16 to 30 μm (particularly 18 to 27 μm). If the average thickness of the first sealant layer is too thick, curling may occur on the bottom material side, which may reduce economic efficiency. If it is too thin, physical properties (impact resistance, puncture strength, etc.) and heat sealing There is a risk that the performance will be reduced.

  The average thickness of the first sealant layer may be 3 times or less with respect to the average thickness of the first outermost layer, for example, 0.5 to 2 times, preferably 1 to 1.5 times, more preferably It is about 1.1 to 1.4 times (particularly 1.2 to 1.3 times). If the thickness of the first sealant layer relative to the first outermost layer is too thick, curling may occur on the bottom material side.

(First adhesive layer)
In the first multilayer film, the first adhesive layer (A) is interposed between the first outermost layer and the first intermediate layer, and between the first intermediate layer and the first sealant layer. The first adhesive layer (B) may be interposed.

  As the adhesive component contained in the first adhesive layer, a conventional adhesive or pressure-sensitive adhesive can be used. Examples of adhesives include vinyl adhesives, polyolefin adhesives, polyamide adhesives, polyester adhesives, urethane adhesives (thermoplastic polyurethane adhesives, two-component curable polyurethane resins, etc.), cellulose Examples thereof include a system adhesive and a rubber adhesive. Examples of the pressure-sensitive adhesive include rubber-based pressure-sensitive adhesives, acrylic pressure-sensitive adhesives, and olefin-based pressure-sensitive adhesives (modified olefin-based pressure-sensitive adhesives). Among these adhesive components, urethane adhesives are preferable from the viewpoint of high adhesiveness and flexibility, and two-component curable polyester urethane resins are particularly preferable from the viewpoint of heat resistance.

  The adhesive component contained in the first adhesive layer (A) and the adhesive component contained in the first adhesive layer (B) may be different adhesive components, but are usually the same adhesive component.

  The first adhesive layer may contain, in addition to the adhesive component, conventional additives exemplified in the section of the unstretched polypropylene resin layer contained in the outermost layer. The ratio of the additive is 50 parts by weight or less, preferably 30 parts by weight or less (for example, 0.01 to 30 parts by weight), more preferably 10 parts by weight or less (for example, 0.1 to 10 parts) with respect to 100 parts by weight of the adhesive component. Part by weight).

  The average thickness of the first adhesive layer is about 0.5 to 7 μm, preferably 1 to 5 μm, and more preferably about 1.4 to 4.2 μm. If the average thickness of the first adhesive layer is too thick, the economic efficiency may be reduced, and if it is too thin, the adhesiveness between the layers may be reduced.

(Print layer)
The first multilayer film may form a printing layer between the first outermost layer and the first intermediate layer, and between the first intermediate layer and the first sealant layer, and the printing workability. It is preferable to print a printing layer on the surface of any one of the 1st intermediate | middle layers from the point which can improve (a). The print layer may be printed on the first sealant layer side of the first intermediate layer, but it is preferable to print on the first outermost layer side from the viewpoint of visibility and the like. Moreover, the printing layer may be printed on the surface of the biaxially stretched polyester-type resin layer, and may be printed on the surface of the barrier film. As the printed layer, a conventional ink composition containing a pigment can be used. Examples of the printing method include screen printing, ink jet printing, intaglio printing (eg, gravure printing), offset printing, intaglio offset printing, flexographic printing, and the like. Of these methods, the gravure printing method is preferable. The average thickness of the printing layer is about 0.1 to 3 μm, preferably about 0.3 to 2 μm, and more preferably about 0.5 to 1.5 μm.

(Characteristics and manufacturing method of first multilayer film)
The first multilayer film has an oxygen barrier property, and has an oxygen permeability of 150 ml / m ² · d · MPa or less, preferably 80 ml under measurement conditions of 20 ° C. and 80% RH in accordance with JIS K7126. / ^m 2 · d · MPa or less (e.g. 0.01~80ml ^/ m about 2 · d · MPa), preferably from 20ml ^/ m 2 · d · MPa or less (e.g. 0.1~20ml ^/ m 2 · d · MPa degree), more preferably from 10ml ^/ m 2 · d · MPa or less (e.g., 1 to 10 ml ^/ m of about 2 · d · MPa) or so.

  The first multilayer film can be produced by a conventional method, for example, a coextrusion molding method, a laminating method (a melt extrusion laminating method, a heat laminating method or a solventless laminating method, a dry laminating method, or the like). Among these methods, the dry laminating method and the solventless laminating method are preferable from the viewpoints of high adhesion between layers, particularly excellent heat resistance, and high adhesion between layers even after heat treatment (particularly boil treatment). In the dry laminating method, the outermost layer, the intermediate layer, and the sealant layer can be integrated by interposing a dry laminating adhesive as an adhesive layer. In the solventless laminating method, the outermost layer, the intermediate layer, and the sealant layer can be integrated by interposing a solventless laminating adhesive as the adhesive layer.

[Bottom material]
The bottom material is formed of a second multilayer film, and includes a concave portion for accommodating an object to be packaged, and a flange portion that produces a flat shape from the periphery of the concave portion and can be heat-sealed. Have. The average thickness of the bottom material (second multilayer film) is, for example, about 30 to 200 μm, preferably about 40 to 150 μm, and more preferably about 50 to 100 μm (particularly about 60 to 80 μm). If the average thickness of the second multilayer film is too thin, there is a concern that the feeling of lowering may be reduced, and if it is too thick, flexibility may be reduced and economic efficiency may be reduced.

  The shape of the concave portion can be appropriately selected according to the shape of the article to be packaged, and examples thereof include a columnar shape (particularly a disc shape) and a polygonal columnar shape (particularly a square plate shape). Among these, since the package of the present invention has excellent oxygen barrier properties and anti-curling properties and is suitable for packaging thin foods, a shallow shape (disk shape, square plate shape such as a square shape) is preferable. . The ratio of the average depth of the recess to the average diameter of the recess is: average diameter / average depth = 5/1 to 50/1, preferably 10/1 to 30/1, more preferably 12/1 to 25 /. 1 (especially 15/1 to 20/1).

  The flange portion is integrated with the first sealant layer in the first multilayer film constituting the lid member by heat sealing, and has an action for sealing (especially sealing) the package. The average width of the flange portion is not particularly limited as long as an area capable of firmly heat-sealing with the lid member can be secured, and may be, for example, 5 mm or more, preferably 10 to 100 mm, more preferably 15 to 50 mm (particularly 20 to 20 mm). 40 mm).

  The second multilayer film includes a second outermost layer including an unstretched polyester resin layer, a second intermediate layer, and a second sealant layer in this order.

(Second outermost layer)
The second multilayer film includes a second outermost layer, and the second outermost layer includes an unstretched polyester resin layer. In the present invention, by arranging a layer containing an unstretched polyester resin layer as the second outermost layer, curling in the flange portion of the deep-drawn package can be prevented by combining with the lid material.

  As the polyester resin constituting the non-stretched polyester resin layer, the polyester resin exemplified as the polyester resin constituting the biaxially stretched polyester resin layer in the first intermediate layer can be used. Among the polyester resins, polyethylene arylate resins such as polyethylene terephthalate and polyethylene naphthalate, particularly homopolyesters of ethylene allylate units or copolymers having an ethylene allylate unit content of 80 mol% or more (particularly 90 mol% or more). Polyester is widely used.

  The number average molecular weight of the polyester resin can be selected from a range of about 5000 to 1000000 in terms of polystyrene using GPC (gel permeation chromatography), for example, 10000 to 500000, preferably 12000 to 300000, and more preferably 15000 to 100000. Degree.

  The unstretched polyester resin layer may also contain other thermoplastic resins and polypropylene resins exemplified in the section of the first outermost layer and conventional additives in addition to the polyester resin. The total ratio of other thermoplastic resins and additives is the same as that of the unstretched polypropylene resin layer in the first outermost layer.

  The tensile strength of the unstretched polyester resin layer is, for example, less than 100 MPa, preferably 10 to 90 MPa, and more preferably 30 to 80 MPa (particularly 40 to 70 MPa) by a method based on JIS K7127.

  The second outermost layer may include other resin layers in addition to the unstretched polyester resin layer, but is usually formed of the unstretched polyester resin layer alone.

  The average thickness of the second outermost layer is, for example, about 8 to 50 μm, preferably 10 to 40 μm, and more preferably about 15 to 35 μm (particularly 20 to 30 μm). If the average thickness of the second outermost layer is too thick, the economic efficiency may be reduced, and if it is too thin, the feeling of the back of the film may be reduced.

(Second barrier layer or gas barrier layer)
The second multilayer film further includes a second barrier layer. In this invention, gas barrier property can be provided to a 2nd multilayer film by including a 2nd barrier layer.

  As the second barrier layer, the barrier film exemplified in the section of the first intermediate layer can be used. Among the barrier films, an organic barrier film (in particular, a barrier film made of a vinyl alcohol resin such as an ethylene-vinyl alcohol copolymer) is preferable from the viewpoint of moldability.

  The average thickness of the second barrier layer is the same as that of the barrier film exemplified in the section of the first intermediate layer, and in the case of an organic barrier film, for example, 3 to 20 μm, preferably 4 to 15 μm, and more preferably 5 10 to 10 μm (especially 6 to 8 μm).

(Second sealant layer)
The second multilayer film further includes a second sealant layer, and the second sealant layer may include an unstretched olefin resin layer. In the present invention, when the second sealant layer includes an unstretched olefin resin layer, the heat sealability with the lid formed with the first multilayer film can be improved.

  As the olefin resin constituting the unstretched olefin resin layer, the olefin resin exemplified as the olefin resin in the section of the first sealant layer can be used. The characteristics of the olefin resin are the same as those of the first sealant layer.

  Among the olefin resins, since the transparency is high and the feeling of waist can be improved, it is preferable to include a polyethylene resin (particularly LLDPE), and it may be a polyethylene resin alone, but to improve easy peel properties. In particular, an alloy of a polyethylene resin and a polypropylene resin is particularly preferable. In the unstretched olefin resin layer formed of alloy, the weight ratio of the polyethylene resin and the polypropylene resin is, for example, 90/10 to 10/90, preferably 70/30 to 30/70, and more preferably 60. / 40 to about 40/60.

  The tensile strength of the unstretched olefin-based resin layer is a method based on JIS K7161, for example, less than 100 MPa, preferably 10 to 90 MPa, more preferably 20 to 75 MPa (particularly 25 to 60 MPa).

  The second sealant layer may include other resin layers in addition to the unstretched olefin resin layer, but is usually formed of the unstretched olefin resin layer alone.

  The average thickness of the second sealant layer is, for example, about 1 to 20 μm, preferably 3 to 10 μm, and more preferably about 4 to 8 μm (particularly 5 to 7 μm). If the average thickness of the second sealant layer is too thick, the economic efficiency may be reduced, and if it is too thin, physical properties (impact resistance, puncture strength, etc.) and heat sealability may be reduced.

  The average thickness of the second sealant layer may be 1 time or less with respect to the average thickness of the second outermost layer, for example, 0.05 to 1 time, preferably 0.1 to 0.5 times, Preferably it is about 0.15-0.4 times (especially 0.2-0.3 times). If the thickness of the second sealant layer relative to the second outermost layer is too thick, curling may occur.

(Second intermediate layer)
The second multilayer film further includes a second intermediate layer. In the present invention, pinhole resistance can be imparted to the second multilayer film by including the second intermediate layer. The second intermediate layer only needs to be interposed between the second outermost layer and the second sealant layer, and may be interposed between the second outermost layer and the second barrier layer. It may be interposed between the second sealant layer and the second barrier layer. The second intermediate layer may be interposed both between the second outermost layer and the second barrier layer and between the second sealant layer and the second barrier layer. It intervenes on either side.

  The second intermediate layer usually includes a thermoplastic resin layer formed of a thermoplastic resin. Examples of the thermoplastic resin forming the thermoplastic resin layer include olefin resins, styrene resins, chlorine-containing resins, polyester resins, polyamide resins, and the like. These thermoplastic resins can be used alone or in combination of two or more.

  Examples of the polyamide-based resin include aliphatic polyamides such as polyamide 6, polyamide 11, polyamide 12, polyamide 46, and polyamide 66. These polyamide resins can be used alone or in combination of two or more. Of these polyamide-based resins, polyamide 6, polyamide 66 and the like are widely used.

  The number average molecular weight of the polyamide-based resin may be, for example, 5,000 to 200,000, preferably 8,000 to 150,000, and more preferably about 10,000 to 100,000. The number average molecular weight can be measured by gel permeation chromatography using polystyrene or the like as a standard substance.

  The thermoplastic resin layer (polyamide resin layer) may be an unstretched thermoplastic resin layer or a biaxially stretched thermoplastic resin layer. From the viewpoint of moldability and the like, an unstretched thermoplastic resin layer (particularly an unstretched polyamide resin layer) is preferable.

  The tensile strength of the unstretched thermoplastic resin layer (particularly unstretched polyamide resin layer) is, for example, less than 200 MPa, preferably from 50 to 150 MPa, more preferably from 70 to 130 MPa (particularly from 80 to 110 MPa), according to JIS K7127. Degree.

  The average thickness of the second intermediate layer is, for example, about 3 to 20 μm, preferably 4 to 15 μm, and more preferably about 5 to 10 μm (particularly 6 to 8 μm). The average thickness of the second intermediate layer may be 0.1 times or more with respect to the average thickness of the second outermost layer, for example, 0.1 to 1 time, preferably 0.15 to 0.5 times. More preferably, it is about 0.2 to 0.4 times (particularly 0.25 to 0.35 times). If the thickness of the second intermediate layer with respect to the second outermost layer is too thin, pinhole resistance may be reduced.

(Second adhesive layer)
In the second multilayer film, the second adhesive layer (A) may be interposed between the layers. As the adhesive component contained in the second adhesive layer, the adhesive component exemplified in the section of the first adhesive layer can be used. The adhesive component can be selected according to the production method of the second multilayer film, and may be a hot melt adhesive when produced by a coextrusion molding method. Similarly to the first adhesive layer, the second adhesive layer may contain a conventional additive, and the ratio of the additive is the same.

  The average thickness of the second adhesive layer is 5 to 15 μm, preferably 6 to 10 μm, and more preferably about 7 to 9 μm. If the average thickness of the second adhesive layer is too thick, the economic efficiency may be lowered, and if it is too thin, the adhesion between the layers may be lowered.

(Characteristics and production method of second multilayer film)
In the second multilayer film, the second barrier layer is thinned by being stretched by molding. Therefore, it is necessary to set the oxygen barrier property before molding higher than that of the first multilayer film (the value is small as the transmittance). There is. In accordance with JIS K7126, the second multilayer film before molding has an oxygen permeability of 100 ml / m ² · d · MPa or less, preferably 50 ml / m ² · d · MP, at 20 ° C. and 80% RH. MPa or less (e.g. 0.01~50ml ^/ m about 2 · d · MPa), preferably from 15ml ^/ m 2 · d · MPa or less (e.g. 0.1~15ml ^/ m about 2 · d · MPa), more preferably 7ml ^/ m 2 · d · MPa or less (e.g. 1~7ml ^/ m about 2 · d · MPa) or so. The oxygen permeability of the second multilayer film after molding can be selected from the same range as the oxygen permeability of the first multilayer film.

  The second multilayer film can also be produced by the method exemplified in the section of the first multilayer film, and may be either a coextrusion molding method or a laminating method. A molding method is widely used. In particular, since the bottom material needs to be thermoformed, it is particularly preferable to form the bottom material with an unstretched coextruded multilayer film.

[Deep-drawn packaging]
The deep-drawn molded package of the present invention is a combination (set or kit) of the lid material and the bottom material, and in a state in which the package object is accommodated, each sealant layer is heat-sealed, and the package object (Especially sealed).

  The method for producing the deep-drawn molded package of the present invention can use a conventional method. For example, a second drawing of the second multilayer film can be performed by vacuum forming, pressure forming, press forming or the like using a deep drawing machine. After forming the recess on the sealant layer side, the second sealant layer side of the flange formed on the periphery of the recess and the first sceneant layer side of the first multilayer film are opposed to each other, and heat is applied. Sealing methods can be used. Of these methods, compressed air molding is preferred.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. The characteristics of the multilayer films obtained in Examples and Comparative Examples were evaluated by the following methods.

[Raw material used for the first multilayer film]
(First outermost layer)
Heat-resistant unstretched polypropylene film 20 (heat-resistant CPP20): “FPK” manufactured by Futamura Chemical Co., Ltd., average thickness 20 μm, heat bonding temperature 157 ° C.
Heat-resistant unstretched polypropylene film 30 (heat-resistant CPP30): “FAK30” manufactured by Futamura Chemical Co., Ltd., average thickness 30 μm, thermal bonding temperature: 159 ° C.
Heat-resistant unstretched polypropylene film 40 (heat-resistant CPP40): “FAK30” manufactured by Futamura Chemical Co., Ltd., average thickness 40 μm, thermal bonding temperature: 160 ° C.
Non-heat-resistant unstretched polypropylene film 20 (non-heat-resistant CPP 20): “FHK2” manufactured by Futamura Chemical Co., Ltd., average thickness 20 μm, heat bonding temperature 126 ° C.
Biaxially stretched polypropylene film (OPP20): “Pyrene Film-OT P2161” manufactured by Toyobo Co., Ltd., average thickness 20 μm
Organic barrier coat biaxially oriented polypropylene film 20 (KOP20): “Senesi KOP product number: 1000” manufactured by Daicel Value Coating Co., Ltd., average thickness 20 μm
Homopolypropylene extruded film (PP30): unstretched film obtained by extrusion using propylene homopolymer (DSC melting point 164 ° C.), average thickness 30 μm.

(First intermediate layer)
Transparent vapor-deposited PET film 12a (VMPET12a): “HGMCR” manufactured by Toray Film Processing Co., Ltd., average thickness 12 μm
Transparent vapor-deposited PET film 12b (VMPET12b): “Barrier Rocks 1011RG-CW” manufactured by Toray Film Processing Co., Ltd., average thickness 12 μm
Organic barrier coat biaxially stretched PET film (KET12): “Senesi KET product number: 6000” manufactured by Daicel Value Coating Co., Ltd., average thickness 12 μm
Polyethylene terephthalate film 12 (PET12): “FE2001” manufactured by Futamura Chemical Co., Ltd., average thickness 12 μm.

(First sealant layer)
Linear low-density polyethylene film 25 (LLDPE25): “LL-XMN” manufactured by Futamura Chemical Co., Ltd., average thickness 25 μm
Linear low density polyethylene film 30 (LLDPE30): “LL-XTN” manufactured by Futamura Chemical Co., Ltd., average thickness 30 μm
Linear low-density polyethylene film 40a (LLDPE40a): “LL-XTN” manufactured by Futamura Chemical Co., Ltd., average thickness 40 μm
Linear low-density polyethylene film 40b (LLDPE40b): a film obtained by extrusion molding using linear low-density polyethylene (“moretech 0138N” manufactured by Prime Polymer Co., Ltd.), average thickness 40 μm
Linear low-density polyethylene film 50 (LLDPE50): “LL-XMN” manufactured by Futamura Chemical Co., Ltd., average thickness 50 μm.

(First adhesive layer)
Polyester urethane adhesive (for dry laminating): “TM-570 / CAT-RT37” manufactured by Toyo Morton Co., Ltd., two-component curing type laminating adhesive.

[Second multilayer film]
Film A: “Sumilite CEL-4554K” manufactured by Sumitomo Bakelite Co., Ltd., a second outermost layer formed of PET, a second barrier layer formed of EVOH, and a second intermediate layer formed of polyamide Co-extruded multilayer film for food packaging comprising a second sealant layer formed of an alloy of polyethylene resin and polypropylene resin with easy peel properties, average thickness 70 μm

Film B: Coextruded multilayer film produced by the following method (Production Example of Film B)
As the second outermost layer, propylene / ethylene random copolymer resin (DSC melting point 155 ° C.), and as the second intermediate layer, ethylene-vinyl alcohol copolymer (“Eval E105B” manufactured by Kuraray Co., Ltd.) and polyamide (DSM) “Novamid 1030CA” manufactured by Japan Engineering Plastics Co., Ltd.), linear low-density polyethylene (“moretech 0138N” manufactured by Prime Polymer Co., Ltd.) as the second sealant layer, and adhesive ( The second outermost layer 30 [mu] m / second adhesive layer (A) 10 [mu] m / second barrier layer (ethylene-vinyl alcohol copolymer film) using Mitsui Chemicals Admer NF558) 20 μm / second intermediate layer (polyamide film) 20 μm / second adhesive layer (B) 10 μm / second film To obtain a multilayer film having an average thickness of 130μm having a laminated structure of the plant layer 40 [mu] m.

[Oxygen barrier properties]
For the first multilayer films obtained in the examples and comparative examples, the oxygen permeability was measured under the conditions of 20 ° C. and 80% RH in accordance with JIS K7126, and evaluated according to the following criteria.

○: Less than 50 ml / m ² · d · MPa Δ: 50 ml / m ² · d · MPa or more and less than 150 ml / m ² · d · MPa ×: 150 ml / m ² · d · MPa or more.

[Curl and transparency]
Film cut into a size of 170 × 125 mm using the first multilayer film obtained in Examples and Comparative Examples and the second multilayer film (co-extruded multilayer film for food packaging) for forming the bottom material The samples were overlapped so that the sealant layers were in contact with each other, and pressed under the conditions of 138 ° C., 1 MPa, and 2 seconds. Immediately after pressurization, the sample was placed on a horizontal table, and the height (mm) from the horizontal position at each of the four corners was measured to calculate the average height. Curl properties were evaluated according to the following criteria. In addition, the curl to the bottom material side was +, and the curl to the lid material side was negative. Also, practically, since the actual packaging line flows on the line with the bottom side facing up, the flat weight is due to the film's own weight and the weight of the ham. no problem.

(Curl evaluation criteria)
○: −15 mm or more and less than 0 mm Δ: −25 mm or more and less than −15 mm, or 0 mm or more and less than 5 mm ×: less than −25 mm or 5 mm or more.

  Moreover, the heat seal part was observed visually and the degree of the white turbidity of the film was evaluated according to the following criteria.

(Transparency evaluation criteria)
○: No cloudiness ×: There is cloudiness.

Example 1
Heat-resistant unstretched polypropylene film 20 (heat-resistant CPP20) as the first outermost layer, transparent vapor-deposited PET film 12a (VMPET12a) as the first intermediate layer, and linear low-density polyethylene film 25 (LLDPE25) as the first sealant layer Three films were dried using a dry laminating machine ("2DL-110TAW" manufactured by Okazaki Machine Industry Co., Ltd.), line speed 150 m / min, drying temperature; first zone: 55 ° C, second zone: 75 ° C, Third zone: Dry lamination was performed at 85 ° C. to produce a first multilayer film. The inorganic barrier film of the first intermediate layer and the first sealant layer are opposed to each other, and a polyester urethane adhesive is used as the first adhesive layer (A) and the first adhesive layer (B) between the layers. The agent (for dry lamination) was applied in a coating amount so that the dry thickness was 3.8 μm. After evaluating the oxygen barrier property of the obtained first multilayer film, the curl property and transparency were evaluated using the first multilayer film and the film A as the second multilayer film.

Example 2
A first multilayer film was produced in the same manner as in Example 1 except that an organic barrier coat biaxially stretched PET film (KET12) was used instead of the transparent vapor-deposited PET film 12a (VMPET12a) as the first intermediate layer. The oxygen barrier property, curl property and transparency were evaluated.

Example 3
A first multilayer film is produced in the same manner as in Example 1 except that a heat-resistant unstretched polypropylene film 30 (heat-resistant CPP30) is used instead of the heat-resistant unstretched polypropylene film 20 (heat-resistant CPP20) as the first outermost layer. The oxygen barrier property, curl property and transparency were evaluated.

Example 4
The first multilayer film is formed in the same manner as in Example 1 except that a non-heat-resistant unstretched polypropylene film 20 (non-heat-resistant CPP 20) is used instead of the heat-resistant unstretched polypropylene film 20 (heat-resistant CPP 20) as the first outermost layer. Were manufactured and evaluated for oxygen barrier properties, curling properties and transparency.

Example 5
A first multilayer film was produced in the same manner as in Example 1 except that the inorganic barrier film of the first intermediate layer and the first outermost layer were opposed to each other (the first intermediate layer was inverted), and an oxygen barrier was produced. , Curl and transparency were evaluated.

Example 6
The first multilayer film is the same as in Example 1 except that a linear low density polyethylene film 25 (LLDPE25) is used instead of the linear low density polyethylene film 25 (LLDPE25) as the first sealant layer. Were manufactured and evaluated for oxygen barrier properties, curling properties and transparency.

Example 7
As the first sealant layer, instead of the linear low-density polyethylene film 25 (LLDPE25), a linear multilayer film 40a (LLDPE40a) is used instead of the linear low-density polyethylene film 25 (LLDPE25). Were manufactured and evaluated for oxygen barrier properties, curling properties and transparency.

Comparative Example 1
A first multilayer film is produced in the same manner as in Example 1 except that a heat-resistant unstretched polypropylene film 40 (heat-resistant CPP40) is used instead of the heat-resistant unstretched polypropylene film 20 (heat-resistant CPP20) as the first outermost layer. The oxygen barrier property, curl property and transparency were evaluated.

Comparative Example 2
As the first sealant layer, the first multilayer film is manufactured in the same manner as in Example 1 except that the linear low density polyethylene film 25 (LLDPE25) is used instead of the linear low density polyethylene film 25 (LLDPE25). Were manufactured and evaluated for oxygen barrier properties, curling properties and transparency.

Comparative Example 3
As the first outermost layer, instead of the heat-resistant unstretched polypropylene film 20 (heat-resistant CPP20), a first multilayer film is produced in the same manner as in Example 1 except that a biaxially stretched polypropylene film (OPP20) is used. Oxygen barrier properties, curling properties and transparency were evaluated.

Comparative Example 4
Organic barrier coat biaxially stretched polypropylene film 20 (KOP20) as the first outermost layer, polyethylene terephthalate film 12 (PET12) as the first intermediate layer, and linear low density polyethylene film 25 (LLDPE25) as the first sealant layer Using a dry laminating machine ("2DL-110TAW" manufactured by Okazaki Machine Industry Co., Ltd.), a line speed of 150 m / min, a drying temperature; first zone: 55 ° C, second zone: 75 ° C Third zone: Dry lamination was performed under the condition of 85 ° C. to produce a first multilayer film. The first outermost organic barrier film and the second intermediate layer are opposed to each other, and a polyester urethane adhesive is used as the first adhesive layer (A) and the first adhesive layer (B) between each layer. The agent (for dry lamination) was applied in a coating amount so that the dry thickness was 3.8 μm. After evaluating the oxygen barrier property of the obtained first multilayer film, the curl property and transparency were evaluated using the first multilayer film and the film A as the second multilayer film.

Comparative Example 5
Curl properties and transparency were evaluated in the same manner as in Example 1 except that the film B was used as the second multilayer film.

Comparative Example 6
A homopolypropylene extruded film (PP30) as the first outermost layer, a transparent vapor-deposited PET film 12b (VMPET12b) as the first intermediate layer, and a linear low density polyethylene film 40b (LLDPE40b) as the first sealant layer Using a dry laminating machine (“2DL-110TAW” manufactured by Okazaki Machine Industry Co., Ltd.), the film was dried at a line speed of 150 m / min; first zone: 55 ° C., second zone: 75 ° C., third zone : Dry lamination was performed at 85 ° C. to produce a first multilayer film. The inorganic barrier film of the first intermediate layer and the first sealant layer are opposed to each other, and a polyester urethane adhesive is used as the first adhesive layer (A) and the first adhesive layer (B) between the layers. The agent (for dry lamination) was applied in a coating amount so that the dry thickness was 3.8 μm. After evaluating the oxygen barrier property of the obtained first multilayer film, the curl property and transparency were evaluated using the first multilayer film and the film B as the second multilayer film.

  The evaluation results of Examples and Comparative Examples are shown in Table 1.

  As is clear from the results in Table 1, the deep-drawn molded packages of the examples were curled and excellent in oxygen barrier properties and transparency. In particular, the deep-drawn molded packages of Examples 1 and 5-6 had high oxygen barrier properties and high transparency. On the other hand, in the deep-drawn molded package of Comparative Example, curling occurred, and in the deep-drawn molded package of Comparative Example 4, the oxygen barrier property was not sufficient.

  The deep-drawn molded package of the present invention can be used as a package for heat-sealing and sealing food, and is suitable for deep-drawn molded packages of processed meat products such as ham, sausage, bacon, grilled pork and chicken. It is particularly suitable for a deep-drawn package for sealing thin foods such as sliced ham and bacon.

Claims (8)

A lid member formed of a first multilayer film; and a bottom member formed of a second multilayer film and having a recess for accommodating an article to be packaged and a flange portion capable of heat sealing with the lid member. Deep-drawn packaging,
The first multilayer film has an oxygen permeability of 150 ml / m ² · d · MPa or less, a first outermost layer including an unstretched polypropylene resin layer, a biaxially stretched polyester resin layer, and a barrier film A first intermediate layer including a first sealant layer including an unstretched olefin-based resin layer in this order, wherein the first outermost layer has an average thickness of 5 to 35 μm, and the first sealant The average thickness of the layer is 10 to 40 μm, and the second multilayer film comprises a second outermost layer including an unstretched polyester resin layer, a second barrier layer, and a second sealant layer. Deep-drawn packaging including in order.   The deep-drawn molded package according to claim 1, wherein the barrier film contained in the first intermediate layer is an inorganic barrier film.   The deep-drawn molded package according to claim 1 or 2, wherein the heat-bonding temperature of the unstretched polypropylene resin layer contained in the first outermost layer is 135 ° C or higher.   The deep-drawn molded package according to any one of claims 1 to 3, wherein the unstretched olefin-based resin layer contained in the first sealant layer contains linear low-density polyethylene.   The deep drawing molded package according to any one of claims 1 to 4, wherein the average thickness of the first intermediate layer is 7 to 25 µm.   The deep-drawn molded package according to any one of claims 1 to 5, further comprising a second intermediate layer including a polyamide-based resin layer between the second outermost layer and the second sealant layer.   The ratio of the average depth of a recessed part with respect to the average diameter of a recessed part is average diameter / average depth = 5/1-50/1, The deep drawing molded package in any one of Claims 1-6.   The deep-drawn molded package according to any one of claims 1 to 7, which is a deep-drawn molded package for accommodating thin-walled food.