Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C35/00—Heating, cooling or curing, e.g. crosslinking or vulcanising; Apparatus therefor
  • B29C35/02—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould
  • B29C35/08—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould by wave energy or particle radiation
  • B29C35/0805—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould by wave energy or particle radiation using electromagnetic radiation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C51/00—Shaping by thermoforming, i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor
  • B29C51/14—Shaping by thermoforming, i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor using multilayered preforms or sheets
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C55/00—Shaping by stretching, e.g. drawing through a die; Apparatus therefor
  • B29C55/02—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets
  • B29C55/10—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial
  • B29C55/12—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial biaxial
  • B29C55/14—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial biaxial successively
  • B29C55/143—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial biaxial successively firstly parallel to the direction of feed and then transversely thereto
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/28—Layered products comprising a layer of synthetic resin comprising synthetic resins not wholly covered by any one of the sub-groups B32B27/30 - B32B27/42
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
  • B32B27/304—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising vinyl halide (co)polymers, e.g. PVC, PVDC, PVF, PVDF
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
  • B32B27/306—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising vinyl acetate or vinyl alcohol (co)polymers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
  • B32B7/04—Interconnection of layers
  • B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D1/00—Rigid or semi-rigid containers having bodies formed in one piece, e.g. by casting metallic material, by moulding plastics, by blowing vitreous material, by throwing ceramic material, by moulding pulped fibrous material or by deep-drawing operations performed on sheet material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D1/00—Rigid or semi-rigid containers having bodies formed in one piece, e.g. by casting metallic material, by moulding plastics, by blowing vitreous material, by throwing ceramic material, by moulding pulped fibrous material or by deep-drawing operations performed on sheet material
  • B65D1/22—Boxes or like containers with side walls of substantial depth for enclosing contents
  • B65D1/26—Thin-walled containers, e.g. formed by deep-drawing operations
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D65/00—Wrappers or flexible covers; Packaging materials of special type or form
  • B65D65/38—Packaging materials of special type or form
  • B65D65/40—Applications of laminates for particular packaging purposes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C35/00—Heating, cooling or curing, e.g. crosslinking or vulcanising; Apparatus therefor
  • B29C35/02—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould
  • B29C35/08—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould by wave energy or particle radiation
  • B29C35/0805—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould by wave energy or particle radiation using electromagnetic radiation
  • B29C2035/0838—Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mould by wave energy or particle radiation using electromagnetic radiation using laser
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C55/00—Shaping by stretching, e.g. drawing through a die; Apparatus therefor
  • B29C55/005—Shaping by stretching, e.g. drawing through a die; Apparatus therefor characterised by the choice of materials
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C55/00—Shaping by stretching, e.g. drawing through a die; Apparatus therefor
  • B29C55/28—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of blown tubular films, e.g. by inflation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2023/00—Use of polyalkenes or derivatives thereof as moulding material
  • B29K2023/04—Polymers of ethylene
  • B29K2023/06—PE, i.e. polyethylene
  • B29K2023/0608—PE, i.e. polyethylene characterised by its density
  • B29K2023/0616—VLDPE, i.e. very low density polyethylene
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2023/00—Use of polyalkenes or derivatives thereof as moulding material
  • B29K2023/04—Polymers of ethylene
  • B29K2023/08—Copolymers of ethylene
  • B29K2023/083—EVA, i.e. ethylene vinyl acetate copolymer
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2027/00—Use of polyvinylhalogenides or derivatives thereof as moulding material
  • B29K2027/08—PVDC, i.e. polyvinylidene chloride
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
  • B29K2995/0037—Other properties
  • B29K2995/005—Oriented
  • B29K2995/0053—Oriented bi-axially
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
  • B29K2995/0037—Other properties
  • B29K2995/0065—Permeability to gases
  • B29K2995/0067—Permeability to gases non-permeable
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2031/00—Other particular articles
  • B29L2031/712—Containers; Packaging elements or accessories, Packages
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2250/00—Layers arrangement
  • B32B2250/04—4 layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/30—Properties of the layers or laminate having particular thermal properties
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
  • B32B2307/514—Oriented
  • B32B2307/518—Oriented bi-axially
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/72—Density
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/724—Permeability to gases, adsorption
  • B32B2307/7242—Non-permeable
  • B32B2307/7244—Oxygen barrier
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/732—Dimensional properties
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/738—Thermoformability
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/748—Releasability
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2309/00—Parameters for the laminating or treatment process; Apparatus details
  • B32B2309/08—Dimensions, e.g. volume
  • B32B2309/10—Dimensions, e.g. volume linear, e.g. length, distance, width
  • B32B2309/105—Thickness
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2435/00—Closures, end caps, stoppers
  • B32B2435/02—Closures, end caps, stoppers for containers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2439/00—Containers; Receptacles
  • B32B2439/70—Food packaging
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B37/00—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding
  • B32B37/12—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by using adhesives

Definitions

• the present invention relates to a deep drawing multilayer film useful as a deep drawing lid, bottom material, and the like, and a method for producing the same.
• stretch-shrinkable multilayer films have been widely used for food packaging such as raw meat, processed meat products, fish, cheese, and soups.
• a packaging method for these contents a method of filling and packaging the contents in a bag or pouch bag, a method of filling and packaging a film immediately after bag making by a vertical pillow / horizontal pillow packaging machine, and filling and packaging by deep drawing. Methods are generally used.
• the conventional method of filling and packaging by deep drawing uses an unstretched, non-shrinkable multilayer film, especially when filling and packaging unusual contents such as ham, grilled pork and bacon.
• unusual contents such as ham, grilled pork and bacon.
• wrinkles are likely to enter the packaging body due to the lack of fit, and the liquid juice of the contents tends to accumulate due to poor fit with the contents.
• contraction property of a film is scarce, there also existed a fault that the adhesiveness of a film worsened and the preservability of the contents worsened.
• JP 2007-296842 A discloses a vinylidene chloride copolymer as a heat-shrinkable multilayer film for deep drawing having a tight fit with the contents by shrinkage and excellent deep drawing suitability.
• a resin layer made of the first thermoplastic resin is laminated on at least one surface of the intermediate layer made of resin, and further made of a sealant resin having a melting point lower by 5 ° C. than the melting point of the first thermoplastic resin.
• a heat-shrinkable multilayer film for deep drawing having an inner layer and having a predetermined hot water shrinkage ratio is disclosed.
• the multilayer film may not be able to be cut straight from the cut, and can be opened more easily. There has been a need for a possible deep drawing multilayer film.
• the present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide a multilayer film capable of easily opening a package manufactured by deep drawing.
• the inventors of the present invention cut the multilayer film straight from the cut by forming the innermost layer of the multilayer film using an ethylene / vinyl acetate copolymer resin. As a result, it was found that a package manufactured by deep-drawing this multilayer film can be easily opened, and the present invention has been completed.
• the deep drawing multilayer film of the present invention comprises a vinylidene chloride copolymer resin layer as an intermediate layer, a crosslinked olefin resin layer as one surface layer, and an ethylene / vinyl acetate copolymer as the other surface layer.
• At least one of the resin layer and the ethylene / vinyl acetate copolymer resin layer as the other surface layer is further provided with an ethylene / vinyl acetate copolymer resin layer.
• Such a multilayer film for deep drawing comprises a vinylidene chloride copolymer resin layer as an intermediate layer, an olefin resin layer as one surface layer, and an ethylene / vinyl acetate copolymer resin layer as the other surface layer.
• An energy ray from the olefin resin layer side to a multilayer unstretched film further comprising an ethylene / vinyl acetate copolymer resin layer on at least one of the surface layer and the ethylene / vinyl acetate copolymer resin layer.
• the olefin resin is crosslinked by irradiating energy rays from the olefin resin layer side.
• the multilayer biaxially stretched film that has been prepared is obtained by subjecting it to a relaxation treatment of 10 to 40% in the longitudinal and transverse directions, respectively.
• the deep drawing bottom film and the lid film of the present invention are characterized by comprising the deep drawing multilayer film of the present invention.
• the package of the present invention includes the bottom material film of the present invention, the lid material film of the present invention, and the packaged material enclosed by the bottom material film and the lid material film, and the crosslinked olefin-based material.
• the resin layer is an outermost layer, and the ethylene / vinyl acetate copolymer resin layer is an innermost layer.
• the method for producing a deep drawing multilayer film of the present invention comprises a vinylidene chloride copolymer resin layer as an intermediate layer, an olefin resin layer as one surface layer, and an ethylene / vinyl acetate copolymer resin as the other surface layer.
• the multilayer unstretched film further comprising an ethylene / vinyl acetate copolymer resin layer on at least one of the other surface layer and the ethylene / vinyl acetate copolymer resin layer side
• the olefin resin layer side After cross-linking the olefin resin by irradiating with energy rays, biaxial stretching of 2.5 to 4 times in each of the longitudinal direction and the transverse direction is performed to produce a multilayer biaxially stretched film.
• the multilayer unstretched film is biaxially stretched 2.5 to 4 times in the longitudinal and lateral directions, and then irradiated with energy rays from the olefin resin layer side to crosslink the olefin resin.
• the multilayer film for deep drawing of the present invention comprises a vinylidene chloride copolymer resin layer as an intermediate layer, a crosslinked olefin resin layer as one surface layer, and an ethylene / vinyl acetate copolymer resin as the other surface layer.
• PVDC resin Vinylidene chloride copolymer resin
• the vinylidene chloride copolymer resin used in the present invention (hereinafter sometimes referred to as “PVDC resin”) is 60 to 98% by mass of vinylidene chloride and 2 to 40 other monomers copolymerizable with the vinylidene chloride. It is a resin containing a copolymer obtained by copolymerization with mass%. Such an intermediate layer made of PVDC resin functions as a gas barrier layer in the multilayer film of the present invention.
• Examples of monomers (comonomers) copolymerizable with vinylidene chloride as described above include, for example, vinyl chloride; alkyl acrylate esters such as methyl acrylate, ethyl acrylate, butyl acrylate, and lauryl acrylate (alkyl).
• alkyl methacrylate such as methyl methacrylate, butyl methacrylate and lauryl methacrylate (alkyl group having 1 to 18 carbon atoms); vinyl cyanide such as acrylonitrile; aromatic vinyl such as styrene
• a vinyl ester of an aliphatic carboxylic acid having 1 to 18 carbon atoms such as vinyl acetate; an alkyl vinyl ether having 1 to 18 carbon atoms; a vinyl polymerizable unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic acid, fumaric acid; Alkyl of vinyl polymerizable unsaturated carboxylic acid such as acid, fumaric acid, itaconic acid (Including partial esters, having 1 to 18 carbon atoms an alkyl group) ester can be exemplified. These comonomers may be used alone or in combination of two or more.
• the copolymerization ratio of these comonomers is preferably in the range of 3 to 35% by mass, more preferably 3 to 25% by mass, and particularly preferably 4 to 20% by mass.
• the copolymerization ratio of the comonomer is less than the lower limit, internal plasticization tends to be inadequate and melt processability tends to be reduced.
• the upper limit is exceeded, gas barrier property tends to be reduced. .
• the reduced viscosity of the PVDC resin is less than the lower limit, the stretch processability is lowered and the mechanical properties of the biaxially stretched film tend to be lowered.
• the upper limit is exceeded, the melt processability is lowered, and there is a tendency to be colored and the transparency tends to be impaired.
• two or more PVDC resins having different reduced viscosities may be used in combination.
• the PVDC resin used in the present invention can be synthesized by any polymerization method such as a suspension polymerization method, an emulsion polymerization method, or a solution polymerization method.
• a compound is formed as a powder resin, It is preferable to synthesize by a legal method.
• combines by suspension polymerization method, it exists in the tendency which does not require the grinding
• the particle size of such a powder resin made of PVDC resin is preferably in the range of 40 to 600 ⁇ m, and more preferably in the range of 50 to 500 ⁇ m.
• the particle size of the powder resin can be measured, for example, by a dry sieving method using a standard sieve.
• Such PVDC resins include polyethylene wax, oxidized polyethylene wax, polyethylene (low density, high density), ethylene-vinyl acetate copolymer, homopolymer or copolymer of acrylate ester, methacryl as required.
• Other resins such as acid ester homopolymers or copolymers, methyl methacrylate-butadiene-styrene copolymers can be contained.
• acrylic acid esters and methacrylic acid esters are preferably alkyl esters having 1 to 18 carbon atoms in the alkyl group.
• the addition amount is 20 mass parts or less with respect to 100 mass parts of PVDC resin.
• such a PVDC resin can further contain various additives such as a heat stabilizer, a plasticizer, an antioxidant, and a lubricant as required. These various additives may be contained in the monomer composition when the powder resin is produced by the suspension polymerization method.
• the liquid additive is absorbed into the powder resin under the temperature conditions during the production of the powder resin, and the solid addition The agent tends to adhere to the surface of the powder resin.
• heat stabilizer examples include epoxy compounds such as epoxidized vegetable oils, epoxidized animal oils, epoxidized fatty acid esters, and epoxy resin prepolymers; and epoxy group-containing resins. These heat stabilizers may be used alone or in combination of two or more. By adding such a thermal stabilizer to the PVDC resin according to the present invention, the thermal stability of the PVDC resin compound tends to be improved.
• epoxidized vegetable oil and epoxidized animal oil it is possible to use those obtained by epoxidizing natural animal and vegetable oils having unsaturated bonds with hydrogen peroxide, peracetic acid or the like, thereby modifying double bonds to oxirane rings. it can.
• epoxidized vegetable oil epoxidized soybean oil, epoxidized linseed oil and the like are preferable.
• Epoxidized fatty acid esters include epoxidized products of unsaturated fatty acid esters such as epoxidized octyl stearate. Examples of the epoxy resin prepolymer include bisphenol A glycidyl ether.
• the epoxy group-containing resin is not particularly limited as long as it is a resin containing at least one epoxy group.
• a glycidyl group-containing acrylic resin and a glycidyl group-containing methacrylic resin are preferable to use.
• the glycidyl group-containing acrylic resin and / or methacrylic resin is preferably a copolymer containing a glycidyl ester of an unsaturated organic acid capable of vinyl polymerization as a copolymerization component.
• glycidyl group-containing acrylic resin and / or methacrylic resin glycidyl ester of unsaturated organic acid capable of vinyl polymerization, acrylic acid ester and / or methacrylic acid ester not containing glycidyl group, and copolymerization with these monomers Copolymers with other possible ethylenically unsaturated monomers are preferred.
• glycidyl group-containing acrylic resin and / or methacrylic resin examples include glycidyl methacrylate-methyl methacrylate-styrene-butyl acrylate copolymer, glycidyl methacrylate-methyl methacrylate copolymer, and glycidyl methacrylate-methacrylic acid.
• Methyl methacrylate-styrene copolymer glycidyl methacrylate-vinyl chloride copolymer, glycidyl methacrylate-ethyl acrylate copolymer, glycidyl methacrylate-butyl acrylate copolymer, glycidyl methacrylate-vinylidene chloride copolymer Can be mentioned.
• epoxidized vegetable oil is preferably used in the field of food packaging materials.
• a heat stabilizer such as epoxidized vegetable oil is used to prepare a powder resin by containing a part of the amount used in the monomer composition in the polymerization process of the PVDC resin, and when the compound is prepared, the remaining amount is powdered. Can be added to the resin. Furthermore, the total amount of heat stabilizer used may be added during polymerization, or may be blended with the powder resin during compound preparation.
• the addition amount is preferably in the range of 0.05 to 6 parts by mass, and in the range of 0.08 to 5 parts by mass with respect to 100 parts by mass of the PVDC resin. More preferably, the range is 0.1 to 4 parts by mass.
• the addition amount of the heat stabilizer is less than the lower limit, the thermal stability of the PVDC resin compound cannot be sufficiently improved, and molding processing becomes difficult and tends to cause blackening.
• the above upper limit is exceeded, the gas barrier property and cold resistance of the biaxially stretched film tend to decrease or cause fish eyes.
• plasticizer examples include dioctyl phthalate, tributyl acetyl citrate, dibutyl sebacate, dioctyl sebacate, acetylated monoglyceride, acetylated diglyceride, acetylated triglyceride, and acetylated glycerides including 2 to 3 thereof.
• polyester plasticizers such as adipic acid and 1,3-butanediol, adipic acid and 1,4-butanediol, and mixtures of two or more thereof. These plasticizers may be used alone or in combination of two or more.
• plasticizers are contained in a PVDC resin powder resin in a PVDC resin polymerization process, blended with a PVDC resin powder resin, or a combination of these in a PVDC resin compound. Can be contained.
• a plasticizer in the powder resin produced in the polymerization step of the PVDC resin, vinylidene chloride and another monomer copolymerizable therewith are copolymerized in the presence of the plasticizer, or After the copolymerization, a plasticizer can be added to produce a PVDC resin powder resin.
• a plasticizer can be included in the powder resin of the PVDC resin in the polymerization step, and an additional plasticizer can be blended as necessary during blending. Further, the entire amount of the plasticizer to be used may be added at the time of polymerization, or may be blended with the powder resin at the time of preparing the compound.
• the addition amount is preferably in the range of 0.05 to 10 parts by mass, and in the range of 0.1 to 5 parts by mass with respect to 100 parts by mass of the PVDC resin. It is more preferable. This is because when the amount of the plasticizer added is less than the lower limit, the plasticizing effect is poor, and melt extrusion tends to be difficult. On the other hand, when the upper limit is exceeded, gas barrier properties tend to deteriorate.
• antioxidants examples include 2,6-di-tert-butyl-4-methyl-phenol (BHT), triethylene glycol-bis [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) Propionate] [for example, “Irganox 245” (registered trademark) manufactured by BASF Corporation], 2,4-dimethyl-6-S-alkylphenol, 2,4-dimethyl-6- (1-methylpentadecyl) phenol, octadecyl-3 Phenolic antioxidants such as — (3,5-di-tert-butyl-4-hydroxyphenyl) propionate [for example, “Irganox 1076” (registered trademark) ”manufactured by BASF; thiodipropionic acid, distearyl thiodipro Thioether antioxidants such as pionate; trisnonylphenyl phosphite, diste Phosphite antioxidants such as Lil penta
• the lubricant examples include waxes such as oxidized polyethylene wax, paraffin wax, polyethylene wax, montanate ester wax, calcium montanate, and fatty acid esters such as glycerin monoester, which are suitable for melt processing of PVDC resin. .
• examples of the lubricant suitable for the melt processing of the PVDC resin and the secondary processing of the film include monoamides or bisamides of fatty acids such as stearamide.
• the addition amount is usually 2 parts by mass or less with respect to 100 parts by mass of the PVDC resin.
• it is desirable that the amount of addition of the lubricant which is poorly compatible with the PVDC resin and easily causes color unevenness or phase separation in the molded product is minimized or not added.
• the PVDC resin used in the present invention can further contain other stabilizers, ultraviolet absorbers, pH adjusters and the like as necessary.
• inorganic bases such as magnesium hydroxide, magnesium oxide, calcium hydroxyphosphate; weak organic acid salts such as citric acid and alkali metal citrate; ethylenediaminetetraacetate, etc. should be used as appropriate. Can do.
• UV absorber examples include 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, and an appropriate amount can be used as necessary.
• Examples of the pH adjuster include sodium pyrophosphate and disodium dihydrogen pyrophosphate.
• the addition amount is preferably 0.5 parts by mass or less with respect to 100 parts by mass of the PVDC resin.
• these pH adjusters are normally used at the time of superposition
• the olefinic resin used in the present invention includes polyethylene (a copolymer of ethylene and a small amount of ⁇ -olefin) polymerized using a single site catalyst or a metallocene catalyst (hereinafter abbreviated as “SSC”).
• SSC metallocene catalyst
• Linear low-density polyethylene SSC-LLDPE
• linear ultra-low-density polyethylene SSC-VLDPE
• polyethylene polymerized using conventional Ziegler catalysts copolymerization of ethylene and a small amount of ⁇ -olefin
• linear low density polyethylene LLDPE
• very low density polyethylene VLDPE or ULDPE
• ethylene / ⁇ -olefin copolymers except those corresponding to the polyethylene
• EVA ethylene / acrylic acid copolymer
• EAA ethylene / acrylic Ester copolymer
• EAA ethylene-methacrylic acid copolymer
• EAA ethylene-methacrylic acid copolymer
• olefin-based resins such as ethylene-methacrylic acid-acrylic acid ester copolymer.
• the ⁇ -olefin used in the polyethylene and the ethylene / ⁇ -olefin copolymer is an ⁇ -olefin having 4 to 18 carbon atoms (eg, 1-butene, 1-pentene, 4-methylpentene, 1-octene). Is mentioned.
• the ethylene / acrylic acid ester copolymer includes ethylene / methyl acrylate copolymer (ethylene / methyl acrylate copolymer (EMA)), ethylene / ethyl acrylate copolymer (EEA), ethylene / acrylic.
• ethylene / methacrylic acid ester copolymer examples include ethylene / methyl methacrylate copolymer (ethylene / methyl methacrylate copolymer (EMMA)) and ethylene / ethyl methacrylate copolymer. And ethylene / butyl methacrylate copolymer.
• EMMA ethylene / methyl methacrylate copolymer
• ethylene / ethyl methacrylate copolymer ethylene / butyl methacrylate copolymer.
• the vinyl acetate content in the ethylene / vinyl acetate copolymer is preferably 5 to 30% by mass
• the acrylic acid ester content of the ethylene / acrylic acid ester copolymer is preferably 5 to 30% by mass.
• the methacrylic acid ester content of the acid ester copolymer is preferably 5 to 30% by mass.
• Such olefin resin may be used alone or in combination of two or more.
• LLDPE, VLDPE or ULDPE, and ethylene / vinyl acetate copolymer are preferable from the viewpoint of stretchability.
• the ethylene / vinyl acetate copolymer resin (EVA resin) used in the present invention forms the other surface layer in the multilayer film of the present invention and functions as a seal layer.
• EVA resin ethylene / vinyl acetate copolymer resin
• the multilayer film of the present invention not only has excellent sealing strength, but also enables deep drawing at a low temperature of 90 ° C. or lower. As a result, in the package manufactured by deep drawing the multilayer film, the multilayer film can be cut straight from the cut, and the package can be easily opened.
• such an EVA resin layer is between the PVDC resin layer as the intermediate layer and the cross-linked olefin resin layer as the one surface layer, and the intermediate layer. You may further provide in at least one (preferably both) between the PVDC resin layer and the EVA resin layer which is said other surface layer.
• the multilayer film of the present invention has excellent film strength such as heat shrinkage rate, puncture strength and tensile strength, and flexibility.
• Adhesive resin examples include an ethylene copolymer or an acid-modified product thereof. More specifically, ethylene / vinyl acetate copolymer (EVA), ethylene / acrylic acid copolymer (EAA), ethylene / methyl acrylate copolymer (ethylene / methyl acrylate copolymer (EMA)), ethylene -Ethylene-based copolymers such as ethyl acrylate copolymer (ethylene-ethyl acrylate copolymer (EEA)), ethylene-methacrylic acid copolymer (EMAA), ethylene-acrylic acid copolymer (EAA), ionomer , And their modified products with unsaturated carboxylic acids or acid anhydrides such as maleic acid, fumaric acid and acrylic acid. By disposing an adhesive layer made of such an adhesive resin between the respective layers, delamination is suppressed.
• EAA ethylene / acrylic acid copolymer
• EMA ethylene / methyl acrylate cop
• adhesive resins may be used alone or in combination of two or more.
• the multilayer film of the present invention comprises a resin layer comprising the PVDC resin as an intermediate layer, a crosslinked resin layer obtained by crosslinking the olefin resin as one surface layer, and a resin comprising EVA resin as the other surface layer. And an intermediate layer between the PVDC resin layer as the intermediate layer and the cross-linked olefin resin layer as the one surface layer, and the PVDC resin layer as the intermediate layer and the EVA resin as the other surface layer.
• An EVA resin layer is further provided on at least one of the layers (preferably both).
• the resin layer made of the EVA resin between the PVDC resin layer and the crosslinked olefin resin layer is crosslinked.
• an adhesive layer made of the adhesive resin may be disposed between these layers in order to improve interlayer adhesion. In this case, the adhesive layer between the PVDC resin layer and the cross-linked olefin resin layer may be cross-linked.
• the thickness of the multilayer film of the present invention is usually 40 ⁇ m or more from the viewpoint of manufacturability. Moreover, as an upper limit of the thickness of the multilayer film of this invention, 150 micrometers or less are preferable. When the thickness of the multilayer film exceeds the upper limit, the internal pressure in inflation stretching at the time of film production tends to be high, and film formation tends to be difficult. Furthermore, when the multilayer film of the present invention is used as a deep drawing bottom material film, the thickness of the multilayer film is preferably 60 to 150 ⁇ m, and when used as a deep drawing molding lid material film, The thickness of the multilayer film is preferably 30 to 90 ⁇ m.
• the thickness of the PVDC resin layer according to the present invention is preferably 1 to 20 ⁇ m, more preferably 2 to 15 ⁇ m, and particularly preferably 3 to 10 ⁇ m.
• the thickness of the PVDC resin layer is less than the lower limit, gas barrier properties tend to be lowered, and control of the layer thickness during extrusion and film formation tends to be difficult.
• the thickness of the PVDC resin layer exceeds the upper limit, the rigidity of the resulting multilayer film tends to increase excessively and tends to be economically disadvantageous, such as an increase in the amount of packaging material discarded.
• the thickness of the PVDC resin layer is preferably 2 to 20 ⁇ m, more preferably 2 to 15 ⁇ m, and particularly preferably 2 to 10 ⁇ m. Further, when the multilayer film of the present invention is used as a deep drawing lid material film, the thickness of the PVDC resin layer is preferably 1 to 10 ⁇ m.
• the thickness of the crosslinked olefin resin layer according to the present invention is preferably 1 to 20 ⁇ m, more preferably 2 to 15 ⁇ m.
• the thickness of the crosslinked olefin-based resin layer is less than the lower limit, the melt hole resistance, heat resistance, and mechanical strength tend to decrease.
• the upper limit is exceeded, the multilayer film becomes too hard and the stretchability decreases. Tend to.
• the thickness of the EVA resin layer (seal layer) as the other surface layer is preferably 1 to 50 ⁇ m, more preferably 5 to 30 ⁇ m.
• the thickness of the sealing layer is less than the lower limit, the sealing strength tends to decrease, and it is difficult to easily open the package.
• the thickness of the seal layer exceeds the upper limit, the strength of the package is insufficient and the transparency of the film tends to be lowered.
• the thickness of the crosslinked EVA resin layer disposed between the PVDC resin layer and the crosslinked olefin resin layer and the EVA resin layer disposed between the PVDC resin layer and the EVA resin layer serving as a seal layer 3 to 100 ⁇ m is preferable, and 5 to 70 ⁇ m is more preferable.
• the thickness of the crosslinked EVA resin layer or the EVA resin layer is less than the lower limit, not only the puncture strength or tensile strength of the multilayer film is lowered, but also the multilayer film is strongly curled inward, which is suitable for a deep drawing packaging machine.
• the upper limit is exceeded, the internal pressure at the time of inflation stretching tends to increase, and the productivity tends to decrease.
• the thickness of the adhesive layer according to the present invention is preferably 1 to 10 ⁇ m, more preferably 1 to 5 ⁇ m.
• the thickness of the adhesive layer is less than the lower limit, interlaminar adhesion tends to decrease.
• the upper limit is exceeded, no further improvement in adhesive strength can be expected, and the amount of packaging materials discarded increases. It tends to be an economic disadvantage.
• the hot water shrinkage in the longitudinal direction and the transverse direction at a temperature of 90 ° C. is preferably 20 to 50%.
• the hot water shrinkage is a value measured by the following method. That is, a film sample marked at a distance of 10 cm in the machine direction (longitudinal direction, MD) of the multilayer film and in the direction perpendicular to the machine direction (lateral direction, TD) is immersed in hot water adjusted to 90 ° C. for 10 seconds.
• the oxygen gas permeability is preferably 100 cm 3 / m 2 ⁇ day ⁇ atm or less, and 80 cm 3 / m 2 ⁇ day ⁇ atm or less under the conditions of a temperature of 23 ° C. and 100% RH. More preferred is 50 cm 3 / m 2 ⁇ day ⁇ atm or less.
• the moisture permeability (WVTR) is preferably 20 g / m 2 ⁇ day or less under conditions of a temperature of 40 ° C. and 90% RH in terms of reduction. If the moisture permeability (WVTR) exceeds the above upper limit, the moisture of the package to be packaged is likely to permeate and evaporate, and the taste amount that is the mass of the package tends not to be maintained.
• the package of the present invention is obtained by packaging an object to be packaged such as raw meat, processed meat products, fish, cheese, fruits, and pizzas using the multilayer film for deep drawing according to the present invention.
• a package includes a lid material film and a bottom material film made of the multilayer film of the present invention, and an object to be packaged contained in the lid material film and the bottom material film, and the present invention is concerned.
• the crosslinked olefin-based resin layer is the outermost layer, and the EVA resin layer that is the seal layer is the innermost layer.
• This package is excellent in the sealing strength of the lid and bottom material and can be easily opened. Furthermore, it is excellent in heat resistance, melt hole resistance and mechanical strength.
• the method of producing the deep drawing multilayer film of the present invention is as follows.
• An EVA resin layer is further provided between the olefin resin layer and at least one (preferably both) of the intermediate layer PVDC resin layer and the other surface layer EVA resin layer.
• the multi-layer unstretched film is irradiated with energy rays from the olefin-based resin layer side to cross-link the olefin-based resin, and then biaxially stretched in the longitudinal and transverse directions to produce a multi-layer biaxially stretched film
• the process of The multilayer unstretched film is biaxially stretched in the machine direction and the transverse direction, and then irradiated with energy rays from the olefin resin layer side to crosslink the olefin resin to produce a multilayer biaxially stretched film.
• a process comprising a step of obtaining a multilayer film for deep drawing according to the present invention by subjecting the multilayer biaxially stretched film to relaxation treatment in the longitudinal direction and the transverse direction.
• the multilayer unstretched film between the PVDC resin layer and the olefin resin layer (one surface layer), and the PVDC resin layer and the EVA resin layer ( Between the PVDC resin layer and the cross-linked olefin resin layer, by using what is further provided with an EVA resin layer in at least one (preferably both) of the other surface layer), And, at least one (preferably both) between the PVDC resin layer and the EVA resin layer (seal layer), the EVA resin layer (between the PVDC resin layer and the crosslinked olefin resin layer) , A cross-linked EVA resin layer) can be obtained.
• the multilayer unstretched film used in the method for producing a multilayer film of the present invention is formed by, for example, forming a molten PVDC resin, an olefin resin, and an EVA resin as an intermediate layer, one surface layer, and the other surface layer, respectively.
• the coextruded product obtained by coextrusion can be prepared, for example, by immersing it in water at a temperature lower than the melting point of all the resins constituting it (preferably 5 to 30 ° C.) and cooling it. it can.
• each resin is coextruded using an annular die so that the layer made of the olefin resin is the outermost layer and the EVA resin layer is the innermost layer.
• the PVDC resin layer as the intermediate layer and the olefin resin layer as the one surface layer and the PVDC resin layer as the intermediate layer and the EVA resin layer as the other surface layer
• the EVA resin layer is disposed at least one (preferably both) between the two.
• the multilayer unstretched film thus produced is irradiated with energy rays from the olefin resin layer side. Moreover, you may implement this energy ray irradiation, after biaxially stretching a multilayer unstretched film.
• the olefin resin is cross-linked, and the EVA resin layer disposed between the PVDC resin layer and the olefin resin layer is cross-linked.
• a multilayer film having excellent properties and mechanical strength can be obtained.
• stretchability is also improved.
• the energy rays known energy rays such as electron rays, ultraviolet rays, ⁇ rays, ⁇ rays, ⁇ rays and X rays can be used. From the viewpoint of the crosslinking effect before and after irradiation, electron rays and ⁇ rays are used. Among these, an electron beam is advantageous in terms of workability in manufacturing a molded product and high production capacity.
• the irradiation conditions of the energy beam may be set as appropriate according to the type of energy beam and the intended use. In the case of an electron beam, the acceleration voltage is in the range of 150 to 500 kilovolts, and the irradiation dose is 10 to 200. A range of kilo gray is preferred.
• the multilayer unstretched film is heated, for example, by passing it through a hot water tank at 70 to 90 ° C., and biaxially stretched in the longitudinal and transverse directions to produce a multilayer biaxially stretched film.
• the multilayer unstretched film is tubular, for example, while drawing air in the tubular multilayer unstretched film while drawing the multilayer unstretched film in the longitudinal direction (flow direction of the tubular film), the longitudinal direction and the transverse direction ( By biaxially stretching in the circumferential direction of the tubular film, a tubular multilayer biaxially stretched film is obtained.
• the stretching ratio is preferably 2.5 to 4 times in the longitudinal direction and the transverse direction. When the draw ratio is less than the lower limit, the fit to a desired package tends to be reduced. On the other hand, when the upper limit is exceeded, the film tends to break during stretching.
• an EVA resin layer is disposed between the PVDC resin layer and the olefin resin layer by irradiating energy rays to the olefin resin.
• the obtained multilayer biaxially stretched film is subjected to heat treatment, and further subjected to relaxation (relaxation) treatment in the machine direction and transverse direction simultaneously with the heat treatment, thereby providing a multilayer film suitable for deep drawing. Is obtained.
• the multilayer biaxially stretched film is tubular
• the multilayer biaxially stretched film bubble is formed while air is introduced into the folded tubular multilayer biaxially stretched film, and the outer surface of the multilayer biaxially stretched film bubble is formed.
• a heat treatment is performed by bringing steam or hot water into contact from the side, and a relaxation (relaxation) treatment is performed in the longitudinal direction and the transverse direction simultaneously with the heat treatment, whereby a multilayer film suitable for deep drawing is obtained as a tubular body.
• this tubular multilayer film is cut in the vertical direction (flow direction of the tubular film) to have a flat shape or the like and used for deep drawing.
• the heat treatment temperature is preferably 60 to 95 ° C.
• the relaxation rate is preferably 10 to 40%.
• the relaxation rate is less than the lower limit, the deep drawing suitability tends to be lowered.
• the relaxation rate exceeds the upper limit, the film after relaxation becomes unstable, and stable production tends to be difficult.
• the lamination mode is the thickness (unit: ⁇ m) shown in the parentheses in order from the outside to the inside, and VLDPE1 (5) / EVA1 (36) / EMA (2.5) / PVDC (8) / EMA (2.5 ) / EVA2 (18) / EVA3 (18), each resin is melt-extruded by a plurality of extruders, and the melted resin is introduced into an annular die, where it is melted to have the above layer structure Joined and co-extruded.
• the molten annular body having a temperature of 180 ° C. flowing out from the die outlet was cooled to 10 ° C. in a water bath to obtain an annular body having a flat width of about 186 mm.
• the obtained flat annular body is irradiated with an electron beam from the outside of the flat annular body in an electron beam irradiation apparatus with an acceleration voltage of 275 KeV to give an irradiation dose of 100 kilo gray, and VLDPE1 of the outermost layer and EVA1 inside thereof Were crosslinked.
• This flat annular body is heated while passing warm water of about 82 ° C., and then is made into a bubble-shaped tubular body by 3.5 times in the longitudinal direction (MD) by the inflation method while cooling using a 10 ° C. air ring.
• MD longitudinal direction
• TD transverse direction
• the film was simultaneously biaxially stretched at a stretch ratio of 3.2 times.
• the obtained biaxially stretched film was introduced into a cylindrical heat treatment tube to form a bubble-shaped film, and relaxed at a temperature of 80 ° C. while relaxing 20% in the machine direction (MD) and 20% in the transverse direction (TD).
• a relaxation heat treatment for 2 seconds was performed to obtain an annular biaxially stretched film having a flat width of about 477 mm. Both ends of the annular biaxially stretched film were cut and a multilayer film for deep drawing having a width of 425 mm was wound up.
• Table 2 shows the thickness of the obtained deep drawing multilayer film.
• Example 2 A biaxially stretched film (a multilayer film for deep drawing) was obtained in the same manner as in Example 1 except that the layer configuration and production conditions of the film were changed to the layer configuration and production conditions shown in Table 2, respectively.
• Table 2 shows the thickness of the obtained deep drawing multilayer film.
• Cuts were made in the ears of the package with scissors, and the ease of opening when the cuts were cut in the direction of the bottom material was determined according to the following criteria. The results are shown in Table 3.
• the deep-drawn multilayer films of the present invention (Examples 1 to 5) in which the innermost layer is an ethylene / vinyl acetate copolymer resin layer have the innermost layer of an ionomer resin layer. It was found that the peel strength between the lid and the bottom material was higher than in the cases (Comparative Examples 1 and 3) and the case of the ethylene / methacrylic acid copolymer resin layer (Comparative Example 4).
• the deep drawing multilayer films (Examples 1 to 5) of the present invention in which the innermost layer is an ethylene / vinyl acetate copolymer resin layer are used when the innermost layer is an ionomer resin layer (Comparative Examples 1 and 3).
• the deep-drawn multilayer films (Examples 1 to 5) of the present invention are the case where the innermost layer is an ionomer resin layer (Comparative Examples 1 and 3), VLDPE (Comparative Example 2), and ethylene / methacrylic acid. This is because deep drawing can be performed at a lower temperature than in the case of the copolymer resin layer (Comparative Example 4).
• the multilayer films for deep drawing according to the present invention (Examples 1 to 5) in which the outermost layer VLDPE is crosslinked are more resistant to melt holes than in the case where the outermost layer VLDPE is not crosslinked (Comparative Example 1). It was excellent.
• the reason why the multilayer film of Comparative Example 2 is superior in melt hole resistance is that the outermost layer was formed using LLDPE having a higher melting point than VLDPE.
• the present invention it is possible to obtain a multilayer film that can be deep-drawn at a low temperature of 90 ° C. or lower, and obtained by deep-drawing using such a multilayer film. It becomes possible to easily open the package.
• the multilayer film for deep drawing according to the present invention is useful as a lid material film, a bottom material film or the like for deep drawing.

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