WO2020008893A1 - Layered film and lid - Google Patents

Layered film and lid Download PDF

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Publication number
WO2020008893A1
WO2020008893A1 PCT/JP2019/024457 JP2019024457W WO2020008893A1 WO 2020008893 A1 WO2020008893 A1 WO 2020008893A1 JP 2019024457 W JP2019024457 W JP 2019024457W WO 2020008893 A1 WO2020008893 A1 WO 2020008893A1
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WO
WIPO (PCT)
Prior art keywords
resin
ethylene
base layer
laminated film
sec
Prior art date
Application number
PCT/JP2019/024457
Other languages
French (fr)
Japanese (ja)
Inventor
桂輔 浜崎
智久 木田
古根村　陽之介
森谷　貴史
Original Assignee
Dic株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Dic株式会社 filed Critical Dic株式会社
Priority to JP2019554951A priority Critical patent/JP6624358B1/en
Priority to KR1020207035751A priority patent/KR20210027260A/en
Publication of WO2020008893A1 publication Critical patent/WO2020008893A1/en

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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
    • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
    • 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

Definitions

  • the present invention relates to a laminated film having good adhesiveness to an adherend such as a heat seal portion of a packaging container, and capable of realizing easy-openability that can be suitably peeled.
  • Patent Document 1 describes a lid material in which a base film is bonded to a laminated film having a heat seal layer and a surface layer as an easily-openable lid material.
  • This lid material suppresses resin flow in the heat seal layer by using a resin with lower fluidity than the conventional resin for the surface layer laminated on the heat seal layer, and is excellent regardless of the sealing temperature. It is easy to open.
  • the sealing temperature may be increased in order to suppress the occurrence of sealing failure due to biting of the contents, etc.
  • the adhesive strength is also increased, and as a result, the opening strength is increased, and there is a problem that the easy opening property is not exhibited.
  • the problem to be solved by the present invention is to have good adhesion to a smooth surface to be bonded and a surface to be bonded having an uneven shape, to be able to form a good film, and to be easily peelable.
  • An object of the present invention is to provide a laminated film capable of realizing openability.
  • the present inventors have conducted intensive studies to solve such problems, and as a result, in a specific shear rate region, a polyolefin resin having a specific melt viscosity can be used for the base layer of the laminated film to solve the problems. And completed the present invention.
  • the present invention relates to a laminated film having a base layer (A) and a heat seal layer (B), wherein the viscosity of the base layer (A) at a shear rate of 6 [sec ⁇ 1 ] is 1.4 ⁇ 10 3 [
  • the present invention provides a laminated film containing an ethylene resin (a1) having a viscosity of not less than Pa ⁇ s] and not more than 1.0 ⁇ 10 3 [Pa ⁇ s] at a shear rate of 120 [sec ⁇ 1 ].
  • the laminated film of the present invention can be easily opened even if the sealing temperature is increased, in order to suppress the occurrence of sealing failure due to biting of the contents, etc., so that the laminated film is preferably used as a lid material of a packaging container. Can be.
  • the laminated film of the present invention is a laminated film having a base layer (A) and a heat seal layer (B).
  • the base layer (A) contains an ethylene-based resin as a main resin component, and forms the base layer (A).
  • the melt viscosity at 270 ° C. at a shear rate of 6 [sec ⁇ 1 ] of the resin composition is 1.4 ⁇ 10 3 [Pa ⁇ s] or more, and the resin composition at a shear rate of 120 [sec ⁇ 1 ] is used.
  • It is a laminated film having a melt viscosity at 270 ° C. of 1.0 ⁇ 10 3 [Pa ⁇ s] or less.
  • the base layer (A) in the laminated film of the present invention has a melt viscosity at 270 ° C. at a shear rate of 6 [sec ⁇ 1 ] of at least 1.4 ⁇ 10 3 [Pa ⁇ s] and a shear rate of 120 [sec ⁇ ].
  • 1 ) is a layer formed from a resin composition having a melt viscosity at 270 ° C. of 1.0 ⁇ 10 3 [Pa ⁇ s] or less.
  • the viscosity of the resin composition used for the base layer (A) in the low shear rate region (6 [sec ⁇ 1 ]) is set to 1.4 ⁇ 10 3 [Pa ⁇ s] or more, whereby the heat Outflow of the resin at the time of sealing can be suitably suppressed, and suitable adhesiveness and easy opening property can be realized.
  • the viscosity of the resin composition in a high shear rate region (120 [sec ⁇ 1 ]) to 1.0 ⁇ 10 3 [Pa ⁇ s] or less, favorable fluidity can be realized at the time of production, and good. Film formation becomes possible.
  • the melt viscosity at 270 ° C. at a shear rate of 6 [sec ⁇ 1 ] is preferably 1.5 ⁇ 10 3 [Pa ⁇ s] or more, more preferably 1.7 ⁇ 10 3 [Pa ⁇ s] or more. is there.
  • the upper limit of the melt viscosity at 270 ° C. at a shear rate of 6 [sec ⁇ 1 ] is not particularly limited, but is preferably 6.0 ⁇ 10 3 [Pa ⁇ s] or less, more preferably 4.0 ⁇ 10 3 [Pa ⁇ s]. s]. Further, the melt viscosity at 270 ° C.
  • melt viscosity at 270 ° C. at a shear rate of 120 [sec ⁇ 1 ] is not particularly limited, but is preferably 3.0 ⁇ 10 2 [Pa ⁇ s] or more, more preferably 4.0 ⁇ 10 2 [Pa ⁇ s]. s].
  • the base layer (A) contains an ethylene resin as a main resin component.
  • the ethylene resin include polyethylene resins such as linear low density polyethylene (LLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE), and ethylene-vinyl acetate copolymer. , Ethylene-methyl methacrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, etc., among which linear low density polyethylene (LLDPE), low density polyethylene (LDPE), medium Ethylene resins such as high density polyethylene (MDPE) and high density polyethylene (HDPE) are preferred.
  • LLDPE linear low density polyethylene
  • LDPE low density polyethylene
  • MDPE medium density polyethylene
  • HDPE high density polyethylene
  • the resin composition forming the base layer (A) preferably has a melt flow rate (190 ° C., 21.18 N) of 0.10 to 0.80 [g / 10 min], and 0.20 to 0.70. [G / 10 min] is more preferable.
  • the content of the ethylene resin in the resin component contained in the base layer (A) is preferably 80% by mass or more, and more preferably 90% by mass or more. It is also preferable that the resin component contained in the base layer (A) is composed of only an ethylene-based resin. When the content of the ethylene-based resin is in the above range, the easy-opening property can be easily adjusted.
  • the resin other than the ethylene-based resin examples include a polyolefin-based resin other than the above-mentioned ethylene-based resin, and the like.
  • examples thereof include a propylene homopolymer, a propylene-ethylene copolymer, a propylene-butene-1 copolymer, and a propylene-ethylene-
  • propylene-based resins such as butene-1 copolymer and metallocene catalyst-based polypropylene.
  • the content is preferably 20% by mass or less, more preferably 10% by mass or less, of the resin component contained in the base layer (A). If it exceeds this range, the material strength of the base layer (A) decreases, so that the base layer (A) undergoes cohesive failure at the time of opening or the like, and a suitable easy-openability cannot be obtained.
  • additives may be blended in the base layer (A) as long as the effects of the present invention are not impaired.
  • the additive include an antioxidant, a weather stabilizer, an antistatic agent, an antifogging agent, an antiblocking agent, a lubricant, a nucleating agent, and a pigment.
  • the above-mentioned ethylene-based resin can be preferably used.
  • the melt viscosity at 270 ° C. at a shear rate of 6 [sec ⁇ 1 ] is 3.0 ⁇ 10 3 [Pa] [S]
  • an ethylene resin (a1) having a melt viscosity at 270 ° C. at a shear rate of 120 [sec-1] of 1.4 ⁇ 10 3 [Pa ⁇ s] or less is preferably used.
  • the ethylene resin (a1) has a density of 0.940 to 0.970 [g / cm 3 ] and a melt flow rate (190 ° C., 21.18 N) of 0.10 to 0.70 [g / cm 3 ]. 10 min].
  • the melt viscosity of the ethylene-based resin (a1) at 270 ° C. at a shear rate of 6 [sec ⁇ 1 ] is preferably 3.0 ⁇ 10 3 [Pa ⁇ s] or more, and more preferably 3.3 ⁇ 10 3 [Pa ⁇ s]. .S] or more, and more preferably 3.6 ⁇ 10 3 [Pa ⁇ s] or more.
  • the upper limit of the melt viscosity at 270 ° C. at a shear rate of 6 [sec ⁇ 1 ] is not particularly limited, but is preferably 6.0 ⁇ 10 3 [Pa ⁇ s] or less, more preferably 4.0 ⁇ 10 3 [Pa ⁇ s]. s].
  • the melt viscosity at 270 ° C. at a shear rate of 120 [sec ⁇ 1 ] is preferably 1.4 ⁇ 10 3 [Pa ⁇ s] or less, more preferably 1.3 ⁇ 10 3 [Pa ⁇ s] or less. is there.
  • the lower limit of the melt viscosity at 270 ° C. at a shear rate of 120 [sec ⁇ 1 ] is not particularly limited, but is preferably 8.0 ⁇ 10 2 [Pa ⁇ s] or more, more preferably 9.0 ⁇ 10 2 [Pa ⁇ s]. s].
  • the ethylene-based resin (a1) is not particularly limited.
  • polyethylene resins such as linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE)
  • LLDPE linear low-density polyethylene
  • MDPE medium-density polyethylene
  • HDPE high-density polyethylene
  • polyethylene resins such as linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE) are preferred because of their high heat resistance, and high-density polyethylene (HDPE) is preferred. Particularly preferred.
  • the ethylene resin (a1) preferably has a melt flow rate (190 ° C., 21.18 N) of 0.10 to 0.70 [g / 10 min], and more preferably 0.20 to 0.50 [g / 10 min]. Is more preferable. Use of the ethylene resin (a1) having a melt flow rate in the above range facilitates the easy opening property.
  • the content of the ethylene resin (a1) in the base layer (A) is preferably from 20 to 60% by mass, more preferably from 30 to 50% by mass.
  • the content of the ethylene-based resin (a1) is preferably from 20 to 60% by mass, more preferably from 30 to 50% by mass.
  • the density of the ethylene resin (a1) is preferably 0.940 to 0.970 [g / cm 3 ], and more preferably 0.940 to 0.960 [g / cm 3 ].
  • the base layer (A) has a melt viscosity at 270 ° C. at a shear rate of 6 [sec ⁇ 1 ] of 2.3 ⁇ 10 3 [Pa ⁇ s] or more as a resin other than the ethylene resin (a1), and It is also preferable to use an ethylene resin (a2) having a melt viscosity at 270 ° C. at a shear rate of 120 [sec ⁇ 1 ] of 1.2 ⁇ 10 3 [Pa ⁇ s] or less.
  • the ethylene resin (a2) has a density of 0.920 to 0.940 [g / cm 3 ] and a melt flow rate (190 ° C., 21.18 N) of 0.10 to 1.0 [g / cm 3 ]. 10 min].
  • the melt viscosity of the ethylene-based resin (a2) at 270 ° C. at a shear rate of 6 [sec ⁇ 1 ] is preferably 2.3 ⁇ 10 3 [Pa ⁇ s] or more, more preferably 2.4 ⁇ 10 3 [Pa ⁇ s]. Pa ⁇ s] or more.
  • the upper limit of the melt viscosity at 270 ° C. at a shear rate of 6 [sec ⁇ 1 ] is not particularly limited, but is preferably 4.5 ⁇ 10 3 [Pa ⁇ s] or less, more preferably 4.0 ⁇ 10 3 [Pa ⁇ s]. s].
  • the viscosity and the melt flow rate of the resin composition forming the base layer (A) can be within the above ranges, even lower ones can be preferably used, and 8.0 ⁇ 10 2 [Pa ⁇ s] or less. It is also preferable that it is 7.0 ⁇ 10 2 [Pa ⁇ s] or less.
  • the melt viscosity of the base layer (A) can be easily adjusted to the above range.
  • the ethylene resin (a2) is not particularly limited, and examples thereof include polyethylene resins such as linear low density polyethylene (LLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE). Among them, low-density polyethylene (LDPE) is preferable in that the film formability is improved.
  • LLDPE linear low density polyethylene
  • LDPE low density polyethylene
  • MDPE medium density polyethylene
  • HDPE high density polyethylene
  • LDPE low-density polyethylene
  • the ethylene resin (a2) preferably has a melt flow rate (190 ° C., 21.18 N) of 0.10 to 1.0 [g / 10 min], and more preferably 0.20 to 0.70 [g / 10 min]. Is more preferable. Use of the ethylene resin (a2) having a melt flow rate within the above range facilitates easy opening.
  • the content of the ethylene resin (a2) in the base layer (A) is preferably from 20 to 60% by mass, more preferably from 25 to 50% by mass.
  • the content of the ethylene-based resin (a2) is preferably from 20 to 60% by mass, more preferably from 25 to 50% by mass.
  • the density of the ethylene-based resin (a2) is preferably 0.920 to 0.940 [g / cm 3 ], and more preferably 0.920 to 0.930 [g / cm 3 ].
  • the use of the ethylene resin (a2) having a density within the above range is preferable in that easy opening property is exhibited.
  • the base layer (A) has a melt viscosity at 270 ° C. at a shear rate of 120 [sec ⁇ 1 ] of 1.0 ⁇ 10 3 [Pa ⁇ s] as a resin other than the ethylene-based resins (a1) and (a2). ] It is also preferable to use the following ethylene resin (a3) in combination.
  • the ethylene resin (a3) has a density of 0.920 to 0.960 [g / cm 3 ] 3 and a melt flow rate (190 ° C., 21.18 N) of 0.5 to 8.0 [g]. / 10 min].
  • the melt viscosity at 270 ° C. at a shear rate of 120 [sec ⁇ 1 ] is preferably 1.0 ⁇ 10 3 [Pa ⁇ s] or less, more preferably 8.0 ⁇ 10 2 [Pa ⁇ s] or less.
  • a lower one can be preferably used, and it is 6.0 ⁇ 10 2 [Pa ⁇ s] or less. It is also preferable that it is 5.0 ⁇ 10 2 [Pa ⁇ s] or less.
  • the melt viscosity of the base layer (A) can be easily adjusted to the above range.
  • the melt viscosity of the ethylene resin (a3) at 270 ° C. at a shear rate of 6 [sec ⁇ 1 ] is preferably 3.0 ⁇ 10 2 [Pa ⁇ s] or more, more preferably 4.0 ⁇ 10 2 [Pa ⁇ s].
  • the upper limit of the melt viscosity at 270 ° C. at a shear rate of 6 [sec ⁇ 1 ] is not particularly limited, but is preferably 4.0 ⁇ 10 3 [Pa ⁇ s] or less, more preferably 3.0 ⁇ 10 3 [Pa ⁇ s]. s] or less, and more preferably 2.0 ⁇ 10 3 [Pa ⁇ s] or less.
  • the ethylene-based resin (a3) is not particularly limited.
  • polyethylene resins such as linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE); -Vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, etc., among which linear low density polyethylene (LLDPE) is This is preferable in that the film properties are improved.
  • LLDPE linear low-density polyethylene
  • LDPE low-density polyethylene
  • MDPE medium-density polyethylene
  • HDPE high-density polyethylene
  • LLDPE linear low-density polyethylene
  • LDPE low-density polyethylene
  • MDPE medium-density polyethylene
  • HDPE high-density polyethylene
  • the melt flow rate (190 ° C., 21.18 N) of the ethylene-based resin (a3) is preferably 0.5 to 8.0 [g / 10 min], and 1.0 to 8.0 [g / 10 min]. More preferably, it is more preferably 2.0 to 5.0 [g / 10 min]. Use of the ethylene resin (a3) having a melt flow rate in the above range facilitates easy opening.
  • the content of the ethylene resin (a3) in the base layer (A) is preferably from 20 to 40% by mass, more preferably from 25 to 35% by mass.
  • the content of the ethylene-based resin (a3) is preferably from 20 to 40% by mass, more preferably from 25 to 35% by mass.
  • the density of the ethylene-based resin (a3) is preferably 0.920 to 0.960 [g / cm 3 ], more preferably 0.920 to 0.950 [g / cm 3 ].
  • the use of the ethylene resin (a3) having a density within the above range is preferable in that good resin extrudability is easily ensured.
  • Heat seal layer (B) As the heat seal layer (B) used in the present invention, various heat seal layers used for a packaging film can be appropriately used.
  • the form of opening of the easy-opening laminated film of the present invention is also particularly limited, for example, due to delamination between the base layer (A) and the heat seal layer (B), or due to cohesive failure of the heat seal layer (B).
  • the heat-sealing layer (B) be a layer having cohesive failure because it can cope with various container shapes.
  • the heat seal layer (B) used in the present invention preferably uses an olefin-based resin as a main resin component because it is easy to obtain adhesion to the base layer.
  • an olefin resin a propylene resin or an ethylene resin can be preferably used.
  • propylene-based resin examples include propylene homopolymer, propylene-ethylene copolymer, propylene-butene-1 copolymer, propylene-ethylene-butene-1 copolymer, and metallocene catalyst-based polypropylene.
  • ethylene resin examples include polyethylene resins such as linear low density polyethylene (LLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE), and ethylene-vinyl acetate.
  • polymers ethylene-methyl methacrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, etc., among which linear low density polyethylene (LLDPE) and low density polyethylene (LDPE) , Medium density polyethylene (MDPE), high density polyethylene (HDPE) and the like.
  • the propylene-based resin is preferably a propylene-ethylene random copolymer or a propylene-ethylene-butene-1 random copolymer.
  • high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), and the like can be preferably used.
  • polyethylene having a density of 0.950 g / cm 3 or more can be preferably used, and polyethylene having a density of 0.955 g / cm 3 or more can be preferably used.
  • the content of the olefin-based resin in the heat seal layer is excellent in oil resistance, there is no reduction in seal strength due to heat sterilization of oil-containing food packages, and it is difficult to cause bag breakage.
  • the content is preferably 90% by mass or more of the components, more preferably 95% by mass or more.
  • the heat seal layer used in the present invention it is preferable to use a propylene resin and an ethylene resin among the olefin resins. By using these resins in combination, it becomes easy to realize a suitable opening property due to the cohesive failure property of the heat seal layer.
  • the melt flow rate (230 ° C., 21.18 N) is preferably 2 to 15 [g / 10 min], more preferably 4 to 10 [g / 10 min].
  • the content of each is preferably 30 to 70% by mass of the propylene-based resin and 30 to 70% by mass of the ethylene-based resin, 40 to 60% by mass of the propylene-based resin, and 40 to 60% by mass of the ethylene-based resin. Is more preferable.
  • EMMA ethylene-methyl methacrylate copolymer
  • EAA ethylene-ethyl acrylate copolymer
  • EMA ethylene-methyl Acrylate copolymer
  • E-EA-MAH ethylene-ethyl acrylate-maleic anhydride copolymer
  • EAA ethylene-acrylic acid copolymer
  • EEMAA ethylene-methacrylic acid copolymer
  • Ethylene copolymers furthermore, an ionomer of an ethylene-acrylic acid copolymer, an ionomer of an ethylene-methacrylic acid copolymer, or the like can be used.
  • the content is preferably 20% by mass or less of the resin component contained in the heat seal layer, and more preferably 10% by mass or less. More preferred.
  • various additives and the like may be appropriately used in addition to the above resin components.
  • a lubricant for example, a lubricant, an antiblocking agent, an ultraviolet absorber, a light stabilizer, an antistatic agent, an antifogging agent, a coloring agent, and the like can be appropriately used.
  • these additives are preferably used in an amount of 2 parts by mass or less, more preferably about 0.01 to 1 part by mass, based on 100 parts by mass of the resin component used in the heat seal layer.
  • the laminated film of the present invention is a laminated film having the above-mentioned base layer (A) and heat seal layer (B). With this configuration, the heat seal surface at the opening of the packaging container is smooth. Even if it is a container or a projection container provided with projections, suitable sealing properties and easy opening properties can be realized.
  • the base layer (A) may be composed of a single layer or may be composed of two or more layers.
  • the ratio of the base layer (A) to the total thickness is high, in order to facilitate the adjustment of the thickness with the heat seal layer (B) when using the co-extrusion method, two or more layers are required.
  • the configuration is also preferable because it results in a multilayer film having excellent homogeneity.
  • each layer of the base layer (A) may be a layer having the above-mentioned range of the melt viscosity, and the resin composition constituting each layer of the base layer (A) is as follows. Even the same mixture may be a mixture of resins having different MFRs or densities, or a mixture having different mixing ratios.
  • the thickness (total thickness) of the laminated film of the present invention is preferably from 15 to 100 ⁇ m, and more preferably from 30 to 50 ⁇ m, from the viewpoint of weight reduction of packaging materials in recent years and the point of easy opening. More preferably, there is.
  • the thickness of the base layer (A) is preferably 80 to 95% of the total thickness of the film, and more preferably 85 to 90%.
  • the thickness of the heat seal layer (B) is preferably in the range of 5 to 20% of the total thickness of the film, and more preferably in the range of 10 to 15%. Within this range, the heat seal strength is stable, shows a suitable easy-opening property, and the film is hardly torn when opened.
  • the laminated film of the present invention utilizes the easy-opening property due to the cohesive failure of the heat seal layer (B), but disperses the force to the base layer (A) to easily form the base layer (A).
  • the heat seal layer (B) is designed to be breakable, so that even if the heat seal layer (B) is thin, sufficient openability can be exhibited.
  • the method for producing the easily-openable laminated film of the present invention is not particularly limited, and for example, each resin or resin mixture used for each layer is heated and melted by a separate extruder, and a co-extrusion multilayer die method or a feed block method is used. After laminating the heat seal layer (B) / base layer (A) in a molten state by a method such as the above, a co-extrusion method of forming into a film by inflation, T-die chill roll method or the like may be used.
  • the coextrusion method is preferable because the thickness ratio of each layer can be adjusted relatively freely, and a laminated film excellent in hygiene and cost performance can be obtained.
  • T-die chill roll method capable of performing melt extrusion at a relatively high temperature is preferable.
  • a surface treatment on the base layer (A) in order to improve the adhesiveness with a printing ink or an adhesive.
  • a surface treatment include, for example, corona treatment, plasma treatment, chromic acid treatment, flame treatment, hot air treatment, surface oxidation treatment such as ozone / ultraviolet treatment, and surface unevenness treatment such as sandblasting.
  • it is a corona treatment.
  • the laminated film of the present invention is a film in which a laminated substrate is laminated on the base layer (A) of the laminated film.
  • the laminate substrate is not particularly limited, but is generally a stretched substrate film because it can secure strength not to break, ensure heat resistance at the time of heat sealing, and improve the design of printing. Is preferred.
  • As the stretched base film a biaxially stretched polyester film, a biaxially stretched nylon film, a biaxially stretched polypropylene film or the like can be used. However, in terms of breaking strength, transparency, etc., a biaxially stretched polyester film and a biaxially stretched nylon film are used. Is more preferred.
  • the base film may be subjected to an easy tearing treatment or an antistatic treatment as necessary.
  • the method for producing the laminate film of the present invention is not particularly limited, and examples thereof include a method of laminating a laminate substrate on the base layer (A) layer of the laminated film.
  • a method of laminating a laminate substrate on the laminated film of the present invention include a dry lamination method, a heat lamination method, and a multilayer extrusion coating method. Of these, the dry lamination method is more preferable.
  • the adhesive used for laminating the laminated film and the laminate substrate by the dry lamination method include a polyether-polyurethane-based adhesive and a polyester-polyurethane-based adhesive.
  • the laminated film and the laminated film of the present invention can be suitably used as various packaging materials.
  • it can be suitably used for jelly, tofu, and cooked rice containers, and can be particularly preferably used as a lid material for a packaging container having an opening.
  • polypropylene is preferable.
  • polypropylene is preferable.
  • the content of the propylene monomer unit in the polymer is 70 mol% or more, since sufficient sealing strength can be obtained.
  • the heat-sealing surface of the opening of the packaging container preferably contains the polyolefin-based resin in a proportion of 60% by mass or more, more preferably 80% by mass or more.
  • the content of the polyolefin-based resin on the heat sealing surface is in the above range, it is preferable because particularly preferable sealing strength is easily obtained.
  • the resin that may be used in combination with the polyolefin resin on the heat sealing surface is not particularly limited as long as it has good compatibility with the polypropylene resin and does not hinder heat sealing. Examples include polymers and polyethylene resins such as ethylene- ⁇ -olefin copolymers.
  • the laminated film of the present invention realizes suitable sealing properties and easy-opening properties even if the heat sealing surface of the opening of the packaging container is a smooth packaging container or a projection container provided with projections. it can. In particular, even when performing high-temperature sealing at 170 ° C. or higher, it is possible to achieve a sealing property suitable for any container and an excellent easy-opening property.
  • Example 1 High density polyethylene (density 0.940 g / cm 3 ) using a metallocene catalyst for the base layer (A), melt flow rate (hereinafter, MFR) (190 ° C., 21.18 N) 0.4 g / 10 min, 270 ° C.
  • MFR melt flow rate
  • Example 2 A coextruded laminated film was obtained in the same manner as in Example 1, except that a mixture of 50 parts of m-HDPE, 20 parts of LDPE, and 30 parts of m-LLDPE (1) was used as the resin mixture for the base layer (A).
  • Example 3 A coextruded laminated film was obtained in the same manner as in Example 1, except that a mixture of 50 parts of m-HDPE, 40 parts of LDPE, and 10 parts of m-LLDPE (1) was used as the resin mixture for the base layer (A).
  • Example 4 As the resin mixture for the base layer (A), 40 parts of m-HDPE, 30 parts of LDPE, 20 parts of m-LLDPE (1), a linear low-density polyethylene derived from sugarcane (density 0.918 g / cm 3 , MFR (190 ° C. , 21.18N) 2.3g / 10min, 270 °C melt viscosity 6sec -1: 7.3 ⁇ 10 2 Pa ⁇ s, 120sec -1: 6.0 ⁇ 10 2 Pa ⁇ s) ( hereinafter referred to as bio-LLDPE) 10 A coextruded laminated film was obtained in the same manner as in Example 1 except that the mixture of parts was used.
  • Example 5 A co-extruded laminated film was prepared in the same manner as in Example 1 except that a mixture of 40 parts of m-HDPE, 30 parts of LDPE, 10 parts of m-LLDPE (1), and 20 parts of bio-LLDPE was used as a resin mixture for the base layer (A). Obtained.
  • high-density polyethylene (density 0.946 g / cm 3 , melt flow rate (hereinafter, MFR) (190 ° C, 21.18 N) 0.18 g / 10 min, 270 ° C melt viscosity 6 sec) -1 : 5.3 ⁇ 10 3 Pa ⁇ s, 120 sec ⁇ 1 : 1.2 ⁇ 10 3 Pa ⁇ s) (hereinafter referred to as HDPE (2)) and 20 parts of linear low-density polyethylene using a metallocene catalyst ( density 0.920g / cm 3, MFR (190 °C, 21.18N) 0.85g / 10min, 270 °C melt viscosity 6sec -1: 2.5 ⁇ 10 3 Pa ⁇ s, 120sec -1: 9.9 ⁇ 10 2 Pa ⁇ s) (hereinafter m-LLDPE (2) hereinafter) 50 parts of high density polyethylene (density 0.965 g
  • Example 7 Coextrusion was carried out in the same manner as in Example 6 except that a mixture of 20 parts of HDPE (2), 40 parts of m-LLDPE (2) and 40 parts of HDPE (3) was used as the resin mixture for the base layer (A). A laminated film was obtained.
  • Example 1 A coextruded laminated film was obtained in the same manner as in Example 1 except that a mixture of 80 parts of m-HDPE and 20 parts of m-LLDPE (1) of the base layer (A) was used.
  • Example 2 A coextruded laminated film was obtained in the same manner as in Example 1, except that a mixture of 20 parts of m-HDPE, 20 parts of LDPE and 60 parts of m-LLDPE (1) of the base layer (A) was used.
  • Example 3 A coextruded laminated film was obtained in the same manner as in Example 1 except that a mixture of 100 parts of m-LLDPE (1) of the base layer (A) was used.
  • melt viscosity The melt viscosity when the shear rate was changed at 270 ° C. was measured using a capillary rheometer manufactured by Toyo Seiki.
  • L / D ⁇ 50 mm extruder
  • the laminated films of Examples 1 to 5 of the present invention have good film-forming properties and have suitable sealing properties and easy-opening properties even at high sealing temperatures for various containers.
  • good film-forming properties and favorable easy-openability at a high sealing temperature were not obtained.

Abstract

A layered film having a base layer (A) and a heat-sealing layer (B), wherein the base layer (A) contains an ethylene resin (a1) in which the viscosity at a shearing speed of 6 (sec-1) is 1.4 × 103 (Pa⋅s) or higher and the viscosity at a shearing speed of 120 (sec-1) is 1.0 × 103 (Pa⋅s) or lower. Using this layered film makes it possible to mold an excellent film having excellent adhesive properties with respect to both a smooth adherend surface and an adherend surface that has recesses or projections, and also makes it possible to realize easy-open properties such that the film is suitably removable.

Description

積層フィルム及び蓋材Laminated film and lid material
　本発明は、包装容器のヒートシール部等の被着体に対して良好な接着性を有し、かつ好適に剥離可能な易開封性を実現できる積層フィルムに関するものである。 (4) The present invention relates to a laminated film having good adhesiveness to an adherend such as a heat seal portion of a packaging container, and capable of realizing easy-openability that can be suitably peeled.
　近年医療用具包装体や食品包装において、ユニバーサルデザイン化傾向の中で、社会的弱者（高齢者、幼児、障害者等）に対しての配慮として、消費者が開封しやすい方式、例えば易開封性が重要視されつつある。その中でも、特に容器等に用いられる易開封性の蓋材が重要視されつつある。 In recent years, in the trend of universal design in medical device packaging and food packaging, in consideration of socially vulnerable people (elderly people, infants, disabled people, etc.), consumers can easily open the package, for example, easily openable Is being emphasized. Among them, particularly, easy-open lid materials used for containers and the like are gaining importance.
　特許文献１には、易開封性の蓋材としてヒートシール層と表面層とを備える積層フィルムに基材フィルムを貼りあわせた蓋材が記載されている。この蓋材は、ヒートシール層の上に積層される表面層を従来の一般的な樹脂より流動性の悪い樹脂を用いることによって、ヒートシール層の樹脂流れを抑制し、シール温度に依らず優れた易開封性を示すものである。しかし、前記特許文献で提供された蓋材を実際に使用する場面において、内容物の咬み込み等でシール不良が発生するのを抑制するために、シール温度を上げることがあるが、シール温度を上げると、接着強度も上がることになり、結果として開封強度が強くなり、易開封性が発現しなくなるという問題があった。 Patent Document 1 describes a lid material in which a base film is bonded to a laminated film having a heat seal layer and a surface layer as an easily-openable lid material. This lid material suppresses resin flow in the heat seal layer by using a resin with lower fluidity than the conventional resin for the surface layer laminated on the heat seal layer, and is excellent regardless of the sealing temperature. It is easy to open. However, in a situation where the lid material provided in the patent document is actually used, the sealing temperature may be increased in order to suppress the occurrence of sealing failure due to biting of the contents, etc. When it is increased, the adhesive strength is also increased, and as a result, the opening strength is increased, and there is a problem that the easy opening property is not exhibited.
特開２０１５－０６３０７２号公報JP-A-2015-063072
　イージーピールフィルムは多様な用途に使用されており、その容器形状や封止形態は様々である。このような各種の用途や封止形態に対して、適切にヒートシール可能とし、かつイージーピール性を確保することが望まれる。しかし、ヒートシール性を高めた場合、突起容器等への適用時に、シール条件によっては、樹脂の流れ出しが生じる場合があり、好適な接着性や易開封性が得られない場合があった。一方、樹脂の流れ出しを抑制しようとするとフィルム成形が困難となり、好適な生産性が実現できない場合があった。 ジ ー Easy peel film is used for various purposes, and its container shape and sealing form are various. For such various uses and sealing forms, it is desired to be able to appropriately perform heat sealing and secure easy peelability. However, when the heat sealing property is enhanced, the resin may flow out depending on the sealing conditions when applied to a projection container or the like, and suitable adhesiveness or easy opening property may not be obtained in some cases. On the other hand, when it is attempted to suppress the resin from flowing out, film forming becomes difficult, and there have been cases where suitable productivity cannot be realized.
　本発明が解決しようとする課題は、平滑な被接着面及び凹凸形状を有する被接着面に対して良好な接着性を有し、良好なフィルム成形が可能で、かつ、好適に剥離可能な易開封性を実現できる積層フィルムを提供することにある。 The problem to be solved by the present invention is to have good adhesion to a smooth surface to be bonded and a surface to be bonded having an uneven shape, to be able to form a good film, and to be easily peelable. An object of the present invention is to provide a laminated film capable of realizing openability.
　本発明者は、かかる課題を解決すべく鋭意研究した結果、特定のせん断速度域で、特定の溶融粘度を有するポリオレフィン系樹脂を、積層フィルムのベース層に使用することで、前記課題を解決できることを見出し、本発明を完成した。 The present inventors have conducted intensive studies to solve such problems, and as a result, in a specific shear rate region, a polyolefin resin having a specific melt viscosity can be used for the base layer of the laminated film to solve the problems. And completed the present invention.
　すなわち本発明は、ベース層（Ａ）及びヒートシール層（Ｂ）を有する積層フィルムであって、ベース層（Ａ）が、せん断速度６［ｓｅｃ－１］における粘度が１．４×１０３［Ｐａ・ｓ］以上、かつ、せん断速度１２０［ｓｅｃ－１］における粘度が１．０×１０３［Ｐａ・ｓ］以下のエチレン系樹脂（ａ１）を含有する積層フィルムを提供するものである。 That is, the present invention relates to a laminated film having a base layer (A) and a heat seal layer (B), wherein the viscosity of the base layer (A) at a shear rate of 6 [sec −1 ] is 1.4 × 10 3 [ The present invention provides a laminated film containing an ethylene resin (a1) having a viscosity of not less than Pa · s] and not more than 1.0 × 10 3 [Pa · s] at a shear rate of 120 [sec −1 ].
　本発明の積層フィルムは、内容物の咬み込み等でシール不良が発生するのを抑制するために、シール温度を上げても、開封が容易であるから、包装容器の蓋材として好適に用いることができる。 The laminated film of the present invention can be easily opened even if the sealing temperature is increased, in order to suppress the occurrence of sealing failure due to biting of the contents, etc., so that the laminated film is preferably used as a lid material of a packaging container. Can be.
　本発明の積層フィルムは、ベース層（Ａ）及びヒートシール層（Ｂ）を有する積層フィルムであり、ベース層（Ａ）がエチレン系樹脂を主たる樹脂成分として含有し、ベース層（Ａ）を形成する樹脂組成物のせん断速度６［ｓｅｃ－１］における２７０℃での溶融粘度が１．４×１０３［Ｐａ・ｓ］以上であり、同樹脂組成物のせん断速度１２０［ｓｅｃ－１］における２７０℃での溶融粘度が１．０×１０３［Ｐａ・ｓ］以下の積層フィルムである。 The laminated film of the present invention is a laminated film having a base layer (A) and a heat seal layer (B). The base layer (A) contains an ethylene-based resin as a main resin component, and forms the base layer (A). The melt viscosity at 270 ° C. at a shear rate of 6 [sec −1 ] of the resin composition is 1.4 × 10 3 [Pa · s] or more, and the resin composition at a shear rate of 120 [sec −1 ] is used. It is a laminated film having a melt viscosity at 270 ° C. of 1.0 × 10 3 [Pa · s] or less.
［ベース層（Ａ）］
　本発明の積層フィルムにおけるベース層（Ａ）は、せん断速度６［ｓｅｃ－１］における２７０℃での溶融粘度が１．４×１０３［Ｐａ・ｓ］以上、かつ、せん断速度１２０［ｓｅｃ－１］における２７０℃での溶融粘度が１．０×１０３［Ｐａ・ｓ］以下の樹脂組成物から形成される層である。本発明においては、ベース層（Ａ）に使用する樹脂組成物の低せん断速度域（６［ｓｅｃ－１］）の粘度を１．４×１０３［Ｐａ・ｓ］以上とすることで、ヒートシール時の樹脂の流れ出しを好適に抑制でき、好適な接着性や易開封性を実現できる。また、当該樹脂組成物の高せん断速度域（１２０［ｓｅｃ－１］）の粘度を１．０×１０３［Ｐａ・ｓ］以下とすることで、製造時には好適な流動性を実現でき、良好なフィルム成形が可能となる。 [Base layer (A)]
The base layer (A) in the laminated film of the present invention has a melt viscosity at 270 ° C. at a shear rate of 6 [sec −1 ] of at least 1.4 × 10 3 [Pa · s] and a shear rate of 120 [sec −]. 1 ) is a layer formed from a resin composition having a melt viscosity at 270 ° C. of 1.0 × 10 3 [Pa · s] or less. In the present invention, the viscosity of the resin composition used for the base layer (A) in the low shear rate region (6 [sec −1 ]) is set to 1.4 × 10 3 [Pa · s] or more, whereby the heat Outflow of the resin at the time of sealing can be suitably suppressed, and suitable adhesiveness and easy opening property can be realized. In addition, by setting the viscosity of the resin composition in a high shear rate region (120 [sec −1 ]) to 1.0 × 10 3 [Pa · s] or less, favorable fluidity can be realized at the time of production, and good. Film formation becomes possible.
　せん断速度６［ｓｅｃ－１］における２７０℃での溶融粘度は、好ましくは、１．５×１０３［Ｐａ・ｓ］以上、より好ましくは、１．７×１０３［Ｐａ・ｓ］以上である。せん断速度６［ｓｅｃ－１］における２７０℃での溶融粘度の上限は特に制限されないが、好ましくは６．０×１０３［Ｐａ・ｓ］以下、より好ましくは４．０×１０３［Ｐａ・ｓ］以下である。また、せん断速度１２０［ｓｅｃ－１］における２７０℃での溶融粘度は、好ましくは８．０×１０２［Ｐａ・ｓ］以下である。せん断速度１２０［ｓｅｃ－１］における２７０℃での溶融粘度の下限は特に制限されないが、好ましくは３．０×１０２［Ｐａ・ｓ］以上、より好ましくは４．０×１０２［Ｐａ・ｓ］以上である。 The melt viscosity at 270 ° C. at a shear rate of 6 [sec −1 ] is preferably 1.5 × 10 3 [Pa · s] or more, more preferably 1.7 × 10 3 [Pa · s] or more. is there. The upper limit of the melt viscosity at 270 ° C. at a shear rate of 6 [sec −1 ] is not particularly limited, but is preferably 6.0 × 10 3 [Pa · s] or less, more preferably 4.0 × 10 3 [Pa · s]. s]. Further, the melt viscosity at 270 ° C. at a shear rate of 120 [sec −1 ] is preferably 8.0 × 10 2 [Pa · s] or less. The lower limit of the melt viscosity at 270 ° C. at a shear rate of 120 [sec −1 ] is not particularly limited, but is preferably 3.0 × 10 2 [Pa · s] or more, more preferably 4.0 × 10 2 [Pa · s]. s].
　ベース層（Ａ）は、エチレン系樹脂を主たる樹脂成分として含有する。エチレン系樹脂としては、例えば、直鎖状低密度ポリエチレン（ＬＬＤＰＥ）、低密度ポリエチレン（ＬＤＰＥ）、中密度ポリエチレン（ＭＤＰＥ）、高密度ポリエチレン（ＨＤＰＥ）等のポリエチレン樹脂、エチレン－酢酸ビニル共重合体、エチレン－メチルメタアクリレート共重合体、エチレン－エチルアクリレート共重合体、エチレン－メタアクリル酸共重合体等が挙げられ、中でも直鎖状低密度ポリエチレン（ＬＬＤＰＥ）、低密度ポリエチレン（ＬＤＰＥ）、中密度ポリエチレン（ＭＤＰＥ）、高密度ポリエチレン（ＨＤＰＥ）等のエチレン樹脂が好ましい。 The base layer (A) contains an ethylene resin as a main resin component. Examples of the ethylene resin include polyethylene resins such as linear low density polyethylene (LLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE), and ethylene-vinyl acetate copolymer. , Ethylene-methyl methacrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, etc., among which linear low density polyethylene (LLDPE), low density polyethylene (LDPE), medium Ethylene resins such as high density polyethylene (MDPE) and high density polyethylene (HDPE) are preferred.
　ベース層（Ａ）を形成する樹脂組成物のメルトフローレート（１９０℃、２１．１８Ｎ）は、０．１０～０．８０［ｇ／１０ｍｉｎ］であることが好ましく、０．２０～０．７０［ｇ／１０ｍｉｎ］がより好ましい。ベース層を形成する樹脂組成物のメルトフローレートを上記範囲とすることで、ヒートシール時の樹脂の流動を好適に抑制でき、開封強度が強くなりすぎることなく好適な開封強度を実現しやすくなる。 The resin composition forming the base layer (A) preferably has a melt flow rate (190 ° C., 21.18 N) of 0.10 to 0.80 [g / 10 min], and 0.20 to 0.70. [G / 10 min] is more preferable. By setting the melt flow rate of the resin composition forming the base layer in the above range, the flow of the resin at the time of heat sealing can be suitably suppressed, and it becomes easy to realize a suitable opening strength without excessively increasing the opening strength. .
　ベース層（Ａ）に含まれる樹脂成分中のエチレン系樹脂の含有量は、８０質量％以上であることが好ましく、９０質量％以上であることがより好ましい。また、ベース層（Ａ）に含まれる樹脂成分がエチレン系樹脂のみからなるものであることも好ましい。エチレン系樹脂の含有量を当該範囲とすることで、易開封性を調整しやすくなる。 (4) The content of the ethylene resin in the resin component contained in the base layer (A) is preferably 80% by mass or more, and more preferably 90% by mass or more. It is also preferable that the resin component contained in the base layer (A) is composed of only an ethylene-based resin. When the content of the ethylene-based resin is in the above range, the easy-opening property can be easily adjusted.
　エチレン系樹脂以外の樹脂としては、例えば、上記エチレン系樹脂以外のポリオレフィン系樹脂等を例示でき、プロピレン単独重合体、プロピレン－エチレン共重合体、プロピレン－ブテン－１共重合体、プロピレン－エチレン－ブテン－１共重合体、メタロセン触媒系ポリプロピレン等のプロピレン系樹脂を例示できる。これら他の樹脂を使用する場合には、ベース層（Ａ）に含まれる樹脂成分中の２０質量％以下とすることが好ましく、１０質量％以下とすることがより好ましい。この範囲を超えると、ベース層（Ａ）の材料強度が低下するため、開封時等にベース層（Ａ）が凝集破壊してしまい、好適な易開封性が得られない。 Examples of the resin other than the ethylene-based resin include a polyolefin-based resin other than the above-mentioned ethylene-based resin, and the like. Examples thereof include a propylene homopolymer, a propylene-ethylene copolymer, a propylene-butene-1 copolymer, and a propylene-ethylene- Examples thereof include propylene-based resins such as butene-1 copolymer and metallocene catalyst-based polypropylene. When these other resins are used, the content is preferably 20% by mass or less, more preferably 10% by mass or less, of the resin component contained in the base layer (A). If it exceeds this range, the material strength of the base layer (A) decreases, so that the base layer (A) undergoes cohesive failure at the time of opening or the like, and a suitable easy-openability cannot be obtained.
　ベース層（Ａ）中には、本発明の効果を損なわない範囲で各種の添加剤を配合してもよい。当該添加剤としては、酸化防止剤、耐候安定剤、帯電防止剤、防曇剤、アンチブロッキング剤、滑剤、核剤、顔料等を例示できる。 Various additives may be blended in the base layer (A) as long as the effects of the present invention are not impaired. Examples of the additive include an antioxidant, a weather stabilizer, an antistatic agent, an antifogging agent, an antiblocking agent, a lubricant, a nucleating agent, and a pigment.
（エチレン系樹脂（ａ１））
　ベース層（Ａ）に使用するエチレン系樹脂としては上記エチレン系樹脂を好ましく使用できるが、なかでも、せん断速度６［ｓｅｃ－１］における２７０℃での溶融粘度が３．０×１０３［Ｐａ・ｓ］以上、かつ、せん断速度１２０［ｓｅｃ－１］における２７０℃での溶融粘度が１．４×１０３［Ｐａ・ｓ］以下のエチレン系樹脂（ａ１）を使用することが好ましい。さらに、当該エチレン系樹脂（ａ１）は、その密度が０．９４０～０．９７０［ｇ／ｃｍ３］、メルトフローレート（１９０℃、２１．１８Ｎ）が０．１０～０．７０［ｇ／１０ｍｉｎ］であることが好ましい。 (Ethylene resin (a1))
As the ethylene-based resin used for the base layer (A), the above-mentioned ethylene-based resin can be preferably used. Among them, the melt viscosity at 270 ° C. at a shear rate of 6 [sec −1 ] is 3.0 × 10 3 [Pa] [S] and an ethylene resin (a1) having a melt viscosity at 270 ° C. at a shear rate of 120 [sec-1] of 1.4 × 10 3 [Pa · s] or less is preferably used. Further, the ethylene resin (a1) has a density of 0.940 to 0.970 [g / cm 3 ] and a melt flow rate (190 ° C., 21.18 N) of 0.10 to 0.70 [g / cm 3 ]. 10 min].
　エチレン系樹脂（ａ１）のせん断速度６［ｓｅｃ－１］における２７０℃での溶融粘度は、好ましくは３．０×１０３［Ｐａ・ｓ］以上、より好ましくは３．３×１０３［Ｐａ・ｓ］以上、さらに好ましくは、３．６×１０３［Ｐａ・ｓ］以上である。せん断速度６［ｓｅｃ－１］における２７０℃での溶融粘度の上限は特に制限されないが、好ましくは６．０×１０３［Ｐａ・ｓ］以下、より好ましくは４．０×１０３［Ｐａ・ｓ］以下である。また、せん断速度１２０［ｓｅｃ－１］における２７０℃での溶融粘度は、好ましくは１．４×１０３［Ｐａ・ｓ］以下、さらに好ましくは１．３×１０３［Ｐａ・ｓ］以下である。せん断速度１２０［ｓｅｃ－１］における２７０℃での溶融粘度の下限は特に制限されないが、好ましくは８．０×１０２［Ｐａ・ｓ］以上、より好ましくは９．０×１０２［Ｐａ・ｓ］以上である。エチレン系樹脂として、当該溶融粘度のエチレン系樹脂（ａ１）を使用することで、ベース層（Ａ）の溶融粘度を上記範囲に調整しやすくなる。 The melt viscosity of the ethylene-based resin (a1) at 270 ° C. at a shear rate of 6 [sec −1 ] is preferably 3.0 × 10 3 [Pa · s] or more, and more preferably 3.3 × 10 3 [Pa · s]. .S] or more, and more preferably 3.6 × 10 3 [Pa · s] or more. The upper limit of the melt viscosity at 270 ° C. at a shear rate of 6 [sec −1 ] is not particularly limited, but is preferably 6.0 × 10 3 [Pa · s] or less, more preferably 4.0 × 10 3 [Pa · s]. s]. The melt viscosity at 270 ° C. at a shear rate of 120 [sec −1 ] is preferably 1.4 × 10 3 [Pa · s] or less, more preferably 1.3 × 10 3 [Pa · s] or less. is there. The lower limit of the melt viscosity at 270 ° C. at a shear rate of 120 [sec −1 ] is not particularly limited, but is preferably 8.0 × 10 2 [Pa · s] or more, more preferably 9.0 × 10 2 [Pa · s]. s]. By using the ethylene resin (a1) having the melt viscosity as the ethylene resin, the melt viscosity of the base layer (A) can be easily adjusted to the above range.
　前記エチレン系樹脂（ａ１）としては、特に限定されないが、例えば直鎖状低密度ポリエチレン（ＬＬＤＰＥ）、低密度ポリエチレン（ＬＤＰＥ）、中密度ポリエチレン（ＭＤＰＥ）、高密度ポリエチレン（ＨＤＰＥ）等のポリエチレン樹脂、が挙げられ、中でも直鎖状低密度ポリエチレン（ＬＬＤＰＥ）、中密度ポリエチレン（ＭＤＰＥ）、高密度ポリエチレン（ＨＤＰＥ）等のポリエチレン樹脂が、耐熱性が高い点で好ましく、高密度ポリエチレン（ＨＤＰＥ）が特に好ましい。 The ethylene-based resin (a1) is not particularly limited. For example, polyethylene resins such as linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE) Among them, polyethylene resins such as linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE) are preferred because of their high heat resistance, and high-density polyethylene (HDPE) is preferred. Particularly preferred.
　エチレン系樹脂（ａ１）のメルトフローレート（１９０℃、２１．１８Ｎ）は０．１０～０．７０［ｇ／１０ｍｉｎ］であることが好ましく、更に０．２０～０．５０［ｇ／１０ｍｉｎ］であることがより好ましい。メルトフローレートが当該範囲のエチレン系樹脂（ａ１）を使用することで、易開封性を発現しやすくなる。 The ethylene resin (a1) preferably has a melt flow rate (190 ° C., 21.18 N) of 0.10 to 0.70 [g / 10 min], and more preferably 0.20 to 0.50 [g / 10 min]. Is more preferable. Use of the ethylene resin (a1) having a melt flow rate in the above range facilitates the easy opening property.
　ベース層（Ａ）におけるエチレン系樹脂（ａ１）の含有量は２０～６０質量％が好ましく、３０～５０質量％がより好ましい。エチレン系樹脂（ａ１）の含有量を２０質量％以上とすることでヒートシール時の樹脂の流動を好適に抑制でき、開封強度が強くなりすぎることなく好適な開封強度を実現しやすくなる。また、含有量を６０質量％以下とすることで、良好な樹脂押出性を確保しやすく、好適な生産性を実現しやすくなる。 は The content of the ethylene resin (a1) in the base layer (A) is preferably from 20 to 60% by mass, more preferably from 30 to 50% by mass. By setting the content of the ethylene-based resin (a1) to 20% by mass or more, the flow of the resin at the time of heat sealing can be suitably suppressed, and a suitable opening strength can be easily realized without excessively increasing the opening strength. When the content is 60% by mass or less, good resin extrudability is easily ensured, and suitable productivity is easily realized.
　エチレン系樹脂（ａ１）の密度は、０．９４０～０．９７０［ｇ／ｃｍ３］であることが好ましく、更に０．９４０～０．９６０［ｇ／ｃｍ３］であることが好ましい。 The density of the ethylene resin (a1) is preferably 0.940 to 0.970 [g / cm 3 ], and more preferably 0.940 to 0.960 [g / cm 3 ].
（エチレン系樹脂（ａ２））
　ベース層（Ａ）には、上記エチレン系樹脂（ａ１）以外の樹脂として、せん断速度６［ｓｅｃ－１］における２７０℃での溶融粘度が２．３×１０３［Ｐａ・ｓ］以上、かつ、せん断速度１２０［ｓｅｃ－１］における２７０℃での溶融粘度が１．２×１０３［Ｐａ・ｓ］以下のエチレン系樹脂（ａ２）を併用することも好ましい。また、当該エチレン系樹脂（ａ２）は、その密度が０．９２０～０．９４０［ｇ／ｃｍ３］、メルトフローレート（１９０℃、２１．１８Ｎ）が０．１０～１．０［ｇ／１０ｍｉｎ］であることが好ましい。 (Ethylene resin (a2))
The base layer (A) has a melt viscosity at 270 ° C. at a shear rate of 6 [sec −1 ] of 2.3 × 10 3 [Pa · s] or more as a resin other than the ethylene resin (a1), and It is also preferable to use an ethylene resin (a2) having a melt viscosity at 270 ° C. at a shear rate of 120 [sec −1 ] of 1.2 × 10 3 [Pa · s] or less. The ethylene resin (a2) has a density of 0.920 to 0.940 [g / cm 3 ] and a melt flow rate (190 ° C., 21.18 N) of 0.10 to 1.0 [g / cm 3 ]. 10 min].
　エチレン系樹脂（ａ２）のせん断速度６［ｓｅｃ－１］における２７０℃での溶融粘度は、好ましくは２．３×１０３［Ｐａ・ｓ］以上、より好ましくは、２．４×１０３［Ｐａ・ｓ］以上である。せん断速度６［ｓｅｃ－１］における２７０℃での溶融粘度の上限は特に制限されないが、好ましくは４．５×１０３［Ｐａ・ｓ］以下、より好ましくは４．０×１０３［Ｐａ・ｓ］以下である。また、せん断速度１２０［ｓｅｃ－１］における２７０℃での溶融粘度は、好ましくは１．２×１０３以下、より好ましくは１．０×１０３以下である。また、ベース層（Ａ）を形成する樹脂組成物の粘度やメルトフローレートを上記範囲とできるものであれば、さらに低いものも好ましく使用でき、８．０×１０２［Ｐａ・ｓ］以下であることも好ましく、７．０×１０２［Ｐａ・ｓ］以下であることも好ましい。せん断速度１２０［ｓｅｃ－１］における２７０℃での溶融粘度の下限は特に制限されないが、好ましくは４．０×１０２［Ｐａ・ｓ］以上、より好ましくは５．０×１０２［Ｐａ・ｓ］以上である。エチレン系樹脂として、当該溶融粘度のエチレン系樹脂（ａ２）をエチレン系樹脂（ａ１）に併用することで、ベース層（Ａ）の溶融粘度を上記範囲に調整しやすくなる。 The melt viscosity of the ethylene-based resin (a2) at 270 ° C. at a shear rate of 6 [sec −1 ] is preferably 2.3 × 10 3 [Pa · s] or more, more preferably 2.4 × 10 3 [Pa · s]. Pa · s] or more. The upper limit of the melt viscosity at 270 ° C. at a shear rate of 6 [sec −1 ] is not particularly limited, but is preferably 4.5 × 10 3 [Pa · s] or less, more preferably 4.0 × 10 3 [Pa · s]. s]. The melt viscosity at 270 ° C. at a shear rate of 120 [sec −1 ] is preferably 1.2 × 10 3 or less, more preferably 1.0 × 10 3 or less. Further, as long as the viscosity and the melt flow rate of the resin composition forming the base layer (A) can be within the above ranges, even lower ones can be preferably used, and 8.0 × 10 2 [Pa · s] or less. It is also preferable that it is 7.0 × 10 2 [Pa · s] or less. The lower limit of the melt viscosity at 270 ° C. at a shear rate of 120 [sec −1 ] is not particularly limited, but is preferably 4.0 × 10 2 [Pa · s] or more, more preferably 5.0 × 10 2 [Pa · s]. s]. By using the ethylene resin (a2) having the melt viscosity in combination with the ethylene resin (a1) as the ethylene resin, the melt viscosity of the base layer (A) can be easily adjusted to the above range.
　このエチレン系樹脂（ａ２）は特に限定されないが、例えば直鎖状低密度ポリエチレン（ＬＬＤＰＥ）、低密度ポリエチレン（ＬＤＰＥ）、中密度ポリエチレン（ＭＤＰＥ）、高密度ポリエチレン（ＨＤＰＥ）等のポリエチレン樹脂等が挙げられ、中でも低密度ポリエチレン（ＬＤＰＥ）が、成膜性が良好となる点で好ましい。 The ethylene resin (a2) is not particularly limited, and examples thereof include polyethylene resins such as linear low density polyethylene (LLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE). Among them, low-density polyethylene (LDPE) is preferable in that the film formability is improved.
　エチレン系樹脂（ａ２）のメルトフローレート（１９０℃、２１．１８Ｎ）は０．１０～１．０［ｇ／１０ｍｉｎ］であることが好ましく、更に０．２０～０．７０［ｇ／１０ｍｉｎ］であることがより好ましい。メルトフローレートが当該範囲のエチレン系樹脂（ａ２）を使用することで、易開封性を発現しやすくなる。 The ethylene resin (a2) preferably has a melt flow rate (190 ° C., 21.18 N) of 0.10 to 1.0 [g / 10 min], and more preferably 0.20 to 0.70 [g / 10 min]. Is more preferable. Use of the ethylene resin (a2) having a melt flow rate within the above range facilitates easy opening.
　ベース層（Ａ）におけるエチレン系樹脂（ａ２）の含有量は２０～６０質量％が好ましく、２５～５０質量％がより好ましい。エチレン系樹脂（ａ２）の含有量を２０質量％以上とすることでヒートシール時の樹脂の流動を好適に抑制でき、開封強度が強くなりすぎることなく好適な開封強度を実現しやすくなる。また、含有量を６０質量％以下とすることで、良好な樹脂押出性を確保しやすく、好適な生産性を実現しやすくなる。 は The content of the ethylene resin (a2) in the base layer (A) is preferably from 20 to 60% by mass, more preferably from 25 to 50% by mass. By setting the content of the ethylene-based resin (a2) to 20% by mass or more, the flow of the resin at the time of heat sealing can be suitably suppressed, and a suitable opening strength can be easily realized without excessively increasing the opening strength. When the content is 60% by mass or less, good resin extrudability is easily ensured, and suitable productivity is easily realized.
　エチレン系樹脂（ａ２）の密度は、０．９２０～０．９４０［ｇ／ｃｍ３］であることが好ましく、更に０．９２０～０．９３０［ｇ／ｃｍ３］であることが好ましい。密度が当該範囲のエチレン系樹脂（ａ２）を使用することで、易開封性を発現させる点で好ましい。 The density of the ethylene-based resin (a2) is preferably 0.920 to 0.940 [g / cm 3 ], and more preferably 0.920 to 0.930 [g / cm 3 ]. The use of the ethylene resin (a2) having a density within the above range is preferable in that easy opening property is exhibited.
（エチレン系樹脂（ａ３））
　ベース層（Ａ）には、上記エチレン系樹脂（ａ１）、（ａ２）以外の樹脂として、せん断速度１２０［ｓｅｃ－１］における２７０℃での溶融粘度が１．０×１０３［Ｐａ・ｓ］以下のエチレン系樹脂（ａ３）を併用することも好ましい。また、当該エチレン系樹脂（ａ３）は、その密度が０．９２０～０．９６０［ｇ／ｃｍ３］３、メルトフローレート（１９０℃、２１．１８Ｎ）が０．５～８．０［ｇ／１０ｍｉｎ］であることが好ましい。 (Ethylene resin (a3))
The base layer (A) has a melt viscosity at 270 ° C. at a shear rate of 120 [sec −1 ] of 1.0 × 10 3 [Pa · s] as a resin other than the ethylene-based resins (a1) and (a2). ] It is also preferable to use the following ethylene resin (a3) in combination. The ethylene resin (a3) has a density of 0.920 to 0.960 [g / cm 3 ] 3 and a melt flow rate (190 ° C., 21.18 N) of 0.5 to 8.0 [g]. / 10 min].
　せん断速度１２０［ｓｅｃ－１］における２７０℃での溶融粘度は、好ましくは１．０×１０３［Ｐａ・ｓ］以下、より好ましくは８．０×１０２［Ｐａ・ｓ］以下である。また、ベース層（Ａ）を形成する樹脂組成物の粘度やメルトフローレートを上記範囲とできるものであれば、さらに低いものも好ましく使用でき６．０×１０２［Ｐａ・ｓ］以下であることも好ましく、５．０×１０２［Ｐａ・ｓ］以下であることも好ましい。せん断速度１２０［ｓｅｃ－１］における２７０℃での溶融粘度の下限は特に制限されないが、好ましくは２．０×１０２［Ｐａ・ｓ］以上、より好ましくは３．０×１０２［Ｐａ・ｓ］以上である。エチレン系樹脂として、当該溶融粘度のエチレン系樹脂（ａ３）をエチレン系樹脂（ａ１）、（ａ２）と併用することで、ベース層（Ａ）の溶融粘度を上記範囲に調整しやすくなる。また、エチレン系樹脂（ａ３）のせん断速度６［ｓｅｃ－１］における２７０℃での溶融粘度は、好ましくは３．０×１０２［Ｐａ・ｓ］以上、より好ましくは、４．０×１０２［Ｐａ・ｓ］以上である。せん断速度６［ｓｅｃ－１］における２７０℃での溶融粘度の上限は特に制限されないが、好ましくは４．０×１０３［Ｐａ・ｓ］以下、より好ましくは３．０×１０３［Ｐａ・ｓ］以下、さらに好ましくは２．０×１０３［Ｐａ・ｓ］以下である。 The melt viscosity at 270 ° C. at a shear rate of 120 [sec −1 ] is preferably 1.0 × 10 3 [Pa · s] or less, more preferably 8.0 × 10 2 [Pa · s] or less. Further, as long as the viscosity and the melt flow rate of the resin composition forming the base layer (A) can be set within the above ranges, a lower one can be preferably used, and it is 6.0 × 10 2 [Pa · s] or less. It is also preferable that it is 5.0 × 10 2 [Pa · s] or less. The lower limit of the melt viscosity at 270 ° C. at a shear rate of 120 [sec −1 ] is not particularly limited, but is preferably 2.0 × 10 2 [Pa · s] or more, more preferably 3.0 × 10 2 [Pa · s]. s]. By using the ethylene resin (a3) having the melt viscosity in combination with the ethylene resins (a1) and (a2) as the ethylene resin, the melt viscosity of the base layer (A) can be easily adjusted to the above range. The melt viscosity of the ethylene resin (a3) at 270 ° C. at a shear rate of 6 [sec −1 ] is preferably 3.0 × 10 2 [Pa · s] or more, more preferably 4.0 × 10 2 [Pa · s]. 2 [Pa · s] or more. The upper limit of the melt viscosity at 270 ° C. at a shear rate of 6 [sec −1 ] is not particularly limited, but is preferably 4.0 × 10 3 [Pa · s] or less, more preferably 3.0 × 10 3 [Pa · s]. s] or less, and more preferably 2.0 × 10 3 [Pa · s] or less.
　このエチレン系樹脂（ａ３）は特に限定されないが、例えば直鎖状低密度ポリエチレン（ＬＬＤＰＥ）、低密度ポリエチレン（ＬＤＰＥ）、中密度ポリエチレン（ＭＤＰＥ）、高密度ポリエチレン（ＨＤＰＥ）等のポリエチレン樹脂、エチレン－酢酸ビニル共重合体、エチレン－メチルメタアクリレート共重合体、エチレン－エチルアクリレート共重合体、エチレン－メタアクリル酸共重合体等が挙げられ、中でも直鎖状低密度ポリエチレン（ＬＬＤＰＥ）が、成膜性が良好となる点で好ましい。 The ethylene-based resin (a3) is not particularly limited. For example, polyethylene resins such as linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE); -Vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, etc., among which linear low density polyethylene (LLDPE) is This is preferable in that the film properties are improved.
４
　エチレン系樹脂（ａ３）のメルトフローレート（１９０℃、２１．１８Ｎ）が０．５～８．０［ｇ／１０ｍｉｎ］であることが好ましく、１．０～８．０［ｇ／１０ｍｉｎ］であることがより好ましく、２．０～５．０［ｇ／１０ｍｉｎ］であることがさらに好ましい。メルトフローレートが当該範囲のエチレン系樹脂（ａ３）を使用することで、易開封性を発現しやすくなる。 4
The melt flow rate (190 ° C., 21.18 N) of the ethylene-based resin (a3) is preferably 0.5 to 8.0 [g / 10 min], and 1.0 to 8.0 [g / 10 min]. More preferably, it is more preferably 2.0 to 5.0 [g / 10 min]. Use of the ethylene resin (a3) having a melt flow rate in the above range facilitates easy opening.
　ベース層（Ａ）におけるエチレン系樹脂（ａ３）の含有量は２０～４０質量％が好ましく、２５～３５質量％がより好ましい。エチレン系樹脂（ａ３）の含有量を２０％以上とすることで、良好な樹脂押出性を確保しやすく、好適な生産性を実現しやすくなる。また、含有量を４０％以下とすることで、ヒートシール時の樹脂の流動を好適に抑制でき、開封強度が強くなりすぎることなく好適な開封強度を実現しやすくなる。 は The content of the ethylene resin (a3) in the base layer (A) is preferably from 20 to 40% by mass, more preferably from 25 to 35% by mass. By setting the content of the ethylene-based resin (a3) to 20% or more, it is easy to secure good resin extrudability, and it is easy to realize suitable productivity. Further, by controlling the content to 40% or less, the flow of the resin at the time of heat sealing can be suitably suppressed, and it becomes easy to realize a suitable opening strength without excessively increasing the opening strength.
　エチレン系樹脂（ａ３）の密度は、０．９２０～０．９６０［ｇ／ｃｍ３］であることが好ましく、更に０．９２０～０．９５０［ｇ／ｃｍ３］であることが好ましい。密度が当該範囲のエチレン系樹脂（ａ３）を使用することで、良好な樹脂押出性を確保しやすい点で好ましい。 The density of the ethylene-based resin (a3) is preferably 0.920 to 0.960 [g / cm 3 ], more preferably 0.920 to 0.950 [g / cm 3 ]. The use of the ethylene resin (a3) having a density within the above range is preferable in that good resin extrudability is easily ensured.
［ヒートシール層（Ｂ）］
　本発明に使用するヒートシール層（Ｂ）は、包装用フィルムに使用される各種ヒートシール層を適宜使用できる。本発明の易開封性積層フィルムの開封形態も、ベース層（Ａ）とヒートシール層（Ｂ）間の層間剥離によるものや、ヒートシール層（Ｂ）の凝集破壊によるもの等、特に制限されるものではないが、本ヒートシール層（Ｂ）に凝集破壊性を有する層とすることが多様な容器の形状に対応可能なため、好ましい。 [Heat seal layer (B)]
As the heat seal layer (B) used in the present invention, various heat seal layers used for a packaging film can be appropriately used. The form of opening of the easy-opening laminated film of the present invention is also particularly limited, for example, due to delamination between the base layer (A) and the heat seal layer (B), or due to cohesive failure of the heat seal layer (B). However, it is preferable that the heat-sealing layer (B) be a layer having cohesive failure because it can cope with various container shapes.
　本発明に使用するヒートシール層（Ｂ）は、ベース層との密着性を得やすいことから、オレフィン系樹脂を主たる樹脂成分として使用することが好ましい。当該オレフィン系樹脂としては、プロピレン系樹脂や、エチレン系樹脂を好ましく使用できる。 ヒ ー ト The heat seal layer (B) used in the present invention preferably uses an olefin-based resin as a main resin component because it is easy to obtain adhesion to the base layer. As the olefin resin, a propylene resin or an ethylene resin can be preferably used.
　プロピレン系樹脂としては、プロピレン単独重合体、プロピレン－エチレン共重合体、プロピレン－ブテン－１共重合体、プロピレン－エチレン－ブテン－１共重合体、メタロセン触媒系ポリプロピレン等を例示できる。また、エチレン系樹脂としては、例えば、直鎖状低密度ポリエチレン（ＬＬＤＰＥ）、低密度ポリエチレン（ＬＤＰＥ）、中密度ポリエチレン（ＭＤＰＥ）、高密度ポリエチレン（ＨＤＰＥ）等のポリエチレン樹脂、エチレン－酢酸ビニル共重合体、エチレン－メチルメタアクリレート共重合体、エチレン－エチルアクリレート共重合体、エチレン－メタアクリル酸共重合体等が挙げられ、中でも直鎖状低密度ポリエチレン（ＬＬＤＰＥ）、低密度ポリエチレン（ＬＤＰＥ）、中密度ポリエチレン（ＭＤＰＥ）、高密度ポリエチレン（ＨＤＰＥ）等を例示できる。なかでも、プロピレン系樹脂としては、プロピレン－エチレンランダム共重合体、プロピレン－エチレン－ブテン－１ランダム共重合体が好ましい。また、エチレン系樹脂としては、高密度ポリエチレン（ＨＤＰＥ）、直鎖状低密度ポリエチレン（ＬＬＤＰＥ）や低密度ポリエチレン（ＬＤＰＥ）等を好ましく使用できる。 Examples of the propylene-based resin include propylene homopolymer, propylene-ethylene copolymer, propylene-butene-1 copolymer, propylene-ethylene-butene-1 copolymer, and metallocene catalyst-based polypropylene. Examples of the ethylene resin include polyethylene resins such as linear low density polyethylene (LLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE), and ethylene-vinyl acetate. Polymers, ethylene-methyl methacrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, etc., among which linear low density polyethylene (LLDPE) and low density polyethylene (LDPE) , Medium density polyethylene (MDPE), high density polyethylene (HDPE) and the like. Among them, the propylene-based resin is preferably a propylene-ethylene random copolymer or a propylene-ethylene-butene-1 random copolymer. As the ethylene-based resin, high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), and the like can be preferably used.
　エチレン系樹脂のなかでも、密度０．９５０ｇ／ｃｍ３以上のポリエチレンを好ましく使用でき、なかでも密度０．９５５ｇ／ｃｍ３以上のポリエチレンを好ましく使用できる。 Among the ethylene resins, polyethylene having a density of 0.950 g / cm 3 or more can be preferably used, and polyethylene having a density of 0.955 g / cm 3 or more can be preferably used.
　ヒートシール層中のオレフィン系樹脂の含有量は、耐油性が良好で、油を含む食品の包装体の加熱殺菌によるシール強度低下がなく、破袋を引き起こしにくいため、ヒートシール層に含まれる樹脂成分中の９０質量％以上であることが好ましく、９５質量％以上であることがより好ましい。 The content of the olefin-based resin in the heat seal layer is excellent in oil resistance, there is no reduction in seal strength due to heat sterilization of oil-containing food packages, and it is difficult to cause bag breakage. The content is preferably 90% by mass or more of the components, more preferably 95% by mass or more.
　本発明に使用するヒートシール層としては、上記オレフィン系樹脂の中でも、プロピレン系樹脂とエチレン系樹脂とを併用することが好ましい。これら樹脂を併用することで、ヒートシール層の凝集破壊性による好適な開封性を実現しやすくなる。 ヒ ー ト As the heat seal layer used in the present invention, it is preferable to use a propylene resin and an ethylene resin among the olefin resins. By using these resins in combination, it becomes easy to realize a suitable opening property due to the cohesive failure property of the heat seal layer.
　ポリプロピレン系樹脂とエチレン系樹脂とを併用する場合には、メルトフローレート（２３０℃、２１．１８Ｎ）が、好ましくは２～１５［ｇ／１０ｍｉｎ］、より好ましくは４～１０［ｇ／１０ｍｉｎ］のプロピレン系樹脂と、メルトフローレート（１９０℃、２１．１８Ｎ）が、好ましくは２～２５［ｇ／１０ｍｉｎ］、より好ましくは５～２０［ｇ／１０ｍｉｎ］のエチレン系樹脂とを併用することが好ましい。各々の含有量は、プロピレン系樹脂を３０～７０質量％、エチレン系樹脂を３０～７０質量％とすることが好ましく、プロピレン系樹脂を４０～６０質量％、エチレン系樹脂を４０～６０質量％とすることがより好ましい。 When a polypropylene resin and an ethylene resin are used in combination, the melt flow rate (230 ° C., 21.18 N) is preferably 2 to 15 [g / 10 min], more preferably 4 to 10 [g / 10 min]. Of a propylene-based resin and an ethylene-based resin having a melt flow rate (190 ° C., 21.18 N) of preferably 2 to 25 g / 10 min, more preferably 5 to 20 g / 10 min. Is preferred. The content of each is preferably 30 to 70% by mass of the propylene-based resin and 30 to 70% by mass of the ethylene-based resin, 40 to 60% by mass of the propylene-based resin, and 40 to 60% by mass of the ethylene-based resin. Is more preferable.
　ヒートシール層中の樹脂成分として上記オレフィン系樹脂以外の他の樹脂を使用する場合には、エチレン－メチルメタアクリレート共重合体（ＥＭＭＡ）、エチレン－エチルアクリレート共重合体（ＥＥＡ）、エチレン－メチルアクリレート（ＥＭＡ）共重合体、エチレン－エチルアクリレート－無水マレイン酸共重合体（Ｅ－ＥＡ－ＭＡＨ）、エチレン－アクリル酸共重合体（ＥＡＡ）、エチレン－メタクリル酸共重合体（ＥＭＡＡ）等のエチレン系共重合体；更にはエチレン－アクリル酸共重合体のアイオノマー、エチレン－メタクリル酸共重合体のアイオノマー等使用できる等を使用できる。 When a resin other than the olefin resin is used as the resin component in the heat seal layer, ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl Acrylate (EMA) copolymer, ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH), ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), etc. Ethylene copolymers; furthermore, an ionomer of an ethylene-acrylic acid copolymer, an ionomer of an ethylene-methacrylic acid copolymer, or the like can be used.
　上記オレフィン系樹脂以外の他の樹脂を使用する場合には、その含有量がヒートシール層に含まれる樹脂成分中の２０質量％以下で使用することが好ましく、１０質量％以下で使用することがより好ましい。 When using a resin other than the olefin-based resin, the content is preferably 20% by mass or less of the resin component contained in the heat seal layer, and more preferably 10% by mass or less. More preferred.
　ヒートシール層中には、上記樹脂成分以外に各種添加剤等を適宜併用してもよい。添加剤としては、例えば、滑剤、ブロッキング防止剤、紫外線吸収剤、光安定剤、耐電防止剤、防曇剤等、着色剤等を適宜使用できる。これら添加剤を使用する場合には、ヒートシール層に使用する樹脂成分１００質量部に対して、好ましくは２質量部以下、より好ましくは０．０１～１質量部程度で使用する。 各種 In the heat seal layer, various additives and the like may be appropriately used in addition to the above resin components. As the additive, for example, a lubricant, an antiblocking agent, an ultraviolet absorber, a light stabilizer, an antistatic agent, an antifogging agent, a coloring agent, and the like can be appropriately used. When these additives are used, they are preferably used in an amount of 2 parts by mass or less, more preferably about 0.01 to 1 part by mass, based on 100 parts by mass of the resin component used in the heat seal layer.
［積層フィルム］
　本発明の積層フィルムは、上記のベース層（Ａ）とヒートシール層（Ｂ）とを有する積層フィルムであり、当該構成とすることで、包装容器の開口部のヒートシール面が、平滑な包装容器であっても、突起が設けられた突起容器であっても、好適なシール性と易開封性とを実現できる。 [Laminated film]
The laminated film of the present invention is a laminated film having the above-mentioned base layer (A) and heat seal layer (B). With this configuration, the heat seal surface at the opening of the packaging container is smooth. Even if it is a container or a projection container provided with projections, suitable sealing properties and easy opening properties can be realized.
　本発明の積層フィルムにおいてベース層（Ａ）は単一の層からなるものであっても、２層以上の多層構成からなるものであってよい。特に本発明においてはベース層（Ａ）の全厚に占める割合が高いので、共押出法を用いる際のヒートシール層（Ｂ）との厚み調整を容易にするためには、２層以上の多層構成にすることも、均質性に優れる多層フィルムとなることから好ましいものである。ベース層（Ａ）を多層構成とする場合には、ベース層（Ａ）の各層が上記溶融粘度の範囲となる層とすればよく、ベース層（Ａ）の各層を構成する樹脂組成物は、全く同一の混合物であっても、それぞれのＭＦＲや密度が異なる樹脂の混合物、混合比率が異なる混合物等であってもよい。 に お い て In the laminated film of the present invention, the base layer (A) may be composed of a single layer or may be composed of two or more layers. In particular, in the present invention, since the ratio of the base layer (A) to the total thickness is high, in order to facilitate the adjustment of the thickness with the heat seal layer (B) when using the co-extrusion method, two or more layers are required. The configuration is also preferable because it results in a multilayer film having excellent homogeneity. When the base layer (A) has a multilayer structure, each layer of the base layer (A) may be a layer having the above-mentioned range of the melt viscosity, and the resin composition constituting each layer of the base layer (A) is as follows. Even the same mixture may be a mixture of resins having different MFRs or densities, or a mixture having different mixing ratios.
　本発明の積層フィルムの厚さ（全厚）としては、近年の包装材料の軽量化の観点と、易開封性の点より、１５～１００μｍであることが好ましく、なかでも３０～５０μｍの範囲であることがより好ましい。 The thickness (total thickness) of the laminated film of the present invention is preferably from 15 to 100 μm, and more preferably from 30 to 50 μm, from the viewpoint of weight reduction of packaging materials in recent years and the point of easy opening. More preferably, there is.
　各層の厚さは、ベース層（Ａ）の厚さがフィルムの総厚の８０～９５％であることが好ましく、８５～９０％であることがより好ましい。また、ヒートシール層（Ｂ）の厚さはフィルム全厚の５～２０％の範囲であることが好ましく、１０～１５％の範囲であることがより好ましい。この範囲であると、ヒートシール強度が安定して適度な易開封性を示し、開封時のフィルムの裂けが起こりにくい。本発明の積層フィルムは、ヒートシール層（Ｂ）の凝集破壊による易開封性発現を利用するものであるが、ベース層（Ａ）へ力を分散させ、当該ベース層（Ａ）をも容易に破壊できるように設計しており、そのため、ヒートシール層（Ｂ）が薄くても充分な易開封性を発現することができる。 は Regarding the thickness of each layer, the thickness of the base layer (A) is preferably 80 to 95% of the total thickness of the film, and more preferably 85 to 90%. Further, the thickness of the heat seal layer (B) is preferably in the range of 5 to 20% of the total thickness of the film, and more preferably in the range of 10 to 15%. Within this range, the heat seal strength is stable, shows a suitable easy-opening property, and the film is hardly torn when opened. The laminated film of the present invention utilizes the easy-opening property due to the cohesive failure of the heat seal layer (B), but disperses the force to the base layer (A) to easily form the base layer (A). The heat seal layer (B) is designed to be breakable, so that even if the heat seal layer (B) is thin, sufficient openability can be exhibited.
［積層フィルムの製造方法］
　本発明の易開封性積層フィルムの製造方法としては、特に限定されないが、例えば、各層に用いる各樹脂又は樹脂混合物を、それぞれ別々の押出機で加熱溶融させ、共押出多層ダイス法やフィードブロック法等の方法により溶融状態でヒートシール層（Ｂ）／ベース層（Ａ）、を積層した後、インフレーションやＴダイ・チルロール法等によりフィルム状に成形する共押出する方法が挙げられる。共押出法は、各層の厚さの比率を比較的自由に調整することが可能で、衛生性に優れ、コストパフォーマンスにも優れた積層フィルムが得られるので好ましい。融点とＴｇとの差が大きい樹脂を積層するような場合は、共押出加工時にフィルム外観が劣化したり、均一な層構成形成が困難になったりする場合がある。このような劣化を抑制するためには、比較的高温で溶融押出を行うことができるＴダイ・チルロール法が好ましい。 [Production method of laminated film]
The method for producing the easily-openable laminated film of the present invention is not particularly limited, and for example, each resin or resin mixture used for each layer is heated and melted by a separate extruder, and a co-extrusion multilayer die method or a feed block method is used. After laminating the heat seal layer (B) / base layer (A) in a molten state by a method such as the above, a co-extrusion method of forming into a film by inflation, T-die chill roll method or the like may be used. The coextrusion method is preferable because the thickness ratio of each layer can be adjusted relatively freely, and a laminated film excellent in hygiene and cost performance can be obtained. When laminating a resin having a large difference between the melting point and Tg, the appearance of the film may be deteriorated at the time of co-extrusion or it may be difficult to form a uniform layer structure. In order to suppress such deterioration, a T-die chill roll method capable of performing melt extrusion at a relatively high temperature is preferable.
　さらに、ベース層（Ａ）表面に印刷やラミネート等を行なう場合には、印刷インキや接着剤との接着性等を向上させるため、ベース層（Ａ）に表面処理を施すことが好ましい。このような表面処理としては、例えば、コロナ処理、プラズマ処理、クロム酸処理、火炎処理、熱風処理、オゾン・紫外線処理等の表面酸化処理、あるいはサンドブラスト等の表面凹凸処理を挙げることができるが、好ましくはコロナ処理である。 (4) When printing or laminating the surface of the base layer (A), it is preferable to perform a surface treatment on the base layer (A) in order to improve the adhesiveness with a printing ink or an adhesive. Examples of such surface treatment include, for example, corona treatment, plasma treatment, chromic acid treatment, flame treatment, hot air treatment, surface oxidation treatment such as ozone / ultraviolet treatment, and surface unevenness treatment such as sandblasting. Preferably, it is a corona treatment.
［ラミネートフィルム］
　本発明のラミネートフィルムは、前記積層フィルムのベース層（Ａ）上にラミネート基材が積層されたフィルムである。ラミネート基材としては、特に限定されるものではないが、一般に破断しない強度の確保、ヒ－トシール時の耐熱性確保、および印刷の意匠性向上等が図られることから、延伸基材フィルムであることが好ましい。延伸基材フィルムとしては、２軸延伸ポリエステルフィルム、２軸延伸ナイロンフィルム、２軸延伸ポリプロピレンフィルム等を使用できるが、破断強度、透明性等の点で２軸延伸ポリエステルフィルム及び２軸延伸ナイロンフィルムがより好ましい。なお、前記基材フィルムとしては、必要性に応じて、易裂け性処理や帯電防止処理が施されていてもよい。 [Laminate film]
The laminated film of the present invention is a film in which a laminated substrate is laminated on the base layer (A) of the laminated film. The laminate substrate is not particularly limited, but is generally a stretched substrate film because it can secure strength not to break, ensure heat resistance at the time of heat sealing, and improve the design of printing. Is preferred. As the stretched base film, a biaxially stretched polyester film, a biaxially stretched nylon film, a biaxially stretched polypropylene film or the like can be used. However, in terms of breaking strength, transparency, etc., a biaxially stretched polyester film and a biaxially stretched nylon film are used. Is more preferred. The base film may be subjected to an easy tearing treatment or an antistatic treatment as necessary.
　本発明のラミネートフィルムの製造方法としては、特に限定されないが、例えば、前記積層フィルムのベース層（Ａ）層の上にラミネート基材をラミネートする方法が挙げられる。本発明の前記積層フィルムにラミネート基材をラミネートする方法としては、例えば、ドライラミネート法、熱ラミネート法、多層押出コーティング法等が挙げられるが、これらのなかでも、ドライラミネート法がより好ましい。また、ドライラミネート法で、前記積層フィルムとラミネート基材とをラミネートする際に用いる接着剤としては、例えば、ポリエーテル－ポリウレタン系接着剤、ポリエステル－ポリウレタン系接着剤等が挙げられる。また、本発明の共押出積層フィルムと基材とをラミネートする前に、前記表面層の表面にコロナ放電処理を施すと、基材との密着性が向上するため好ましい。 方法 The method for producing the laminate film of the present invention is not particularly limited, and examples thereof include a method of laminating a laminate substrate on the base layer (A) layer of the laminated film. Examples of a method of laminating a laminate substrate on the laminated film of the present invention include a dry lamination method, a heat lamination method, and a multilayer extrusion coating method. Of these, the dry lamination method is more preferable. Examples of the adhesive used for laminating the laminated film and the laminate substrate by the dry lamination method include a polyether-polyurethane-based adhesive and a polyester-polyurethane-based adhesive. In addition, it is preferable to perform a corona discharge treatment on the surface of the surface layer before laminating the co-extruded laminated film of the present invention and the base material, since the adhesion to the base material is improved.
［包装体］
　本発明の積層フィルム及びラミネートフィルムは、各種の包装用材料として好適に用いることができる。特に、ゼリー、豆腐、米飯容器に好適に用いることができ、開口部を有する包装容器の蓋材として特に好適に使用できる。 [Package]
The laminated film and the laminated film of the present invention can be suitably used as various packaging materials. In particular, it can be suitably used for jelly, tofu, and cooked rice containers, and can be particularly preferably used as a lid material for a packaging container having an opening.
　開口部を有する包装容器に使用するポリオレフィン系樹脂としては、ポリプロピレンが好ましく、例えば、ホモポリプロピレン、プロピレン－エチレン共重合体、プロピレン－ブテン－１共重合体、プロピレン－エチレン－ブテン－１共重合体等のプロピレンの単独重合体又はプロピレンとα－オレフィンとの共重合体が挙げられる。これらのポリプロピレン系樹脂のなかでも、重合体中のプロピレン単量体単位の含有量が７０モル％以上のものであれば、十分なシール強度が得られるので好ましい。 As the polyolefin-based resin used for the packaging container having an opening, polypropylene is preferable. For example, homopolypropylene, propylene-ethylene copolymer, propylene-butene-1 copolymer, propylene-ethylene-butene-1 copolymer And a copolymer of propylene and an α-olefin. Among these polypropylene resins, it is preferable that the content of the propylene monomer unit in the polymer is 70 mol% or more, since sufficient sealing strength can be obtained.
　包装容器の開口部のヒートシール面としては、ポリオレフィン系樹脂を６０質量％以上の割合で含有していることが好ましく、８０質量％以上の割合で含有していることがより好ましい。前記ヒートシール面のポリオレフィン系樹脂の含有量が前記範囲であれば、特に好適なシール強度が得られやすいので好ましい。また、前記ヒートシール面で、ポリオレフィン系樹脂と併用しても良い樹脂としては、ポリプロピレン系樹脂と相溶性が良く、ヒートシールを阻害しない樹脂であれば、特に限定はないが、例えば、エチレン単独重合体、エチレン－α－オレフィン共重合体等のポリエチレン系樹脂等が挙げられる。 (4) The heat-sealing surface of the opening of the packaging container preferably contains the polyolefin-based resin in a proportion of 60% by mass or more, more preferably 80% by mass or more. When the content of the polyolefin-based resin on the heat sealing surface is in the above range, it is preferable because particularly preferable sealing strength is easily obtained. The resin that may be used in combination with the polyolefin resin on the heat sealing surface is not particularly limited as long as it has good compatibility with the polypropylene resin and does not hinder heat sealing. Examples include polymers and polyethylene resins such as ethylene-α-olefin copolymers.
　本発明の積層フィルムは、包装容器の開口部のヒートシール面が、平滑な包装容器であっても、突起が設けられた突起容器であっても、好適なシール性と易開封性とを実現できる。特に、１７０℃以上の高温シールを行う際にも、いずれの容器にも好適なシール性と優れた易開封性を実現できる。 The laminated film of the present invention realizes suitable sealing properties and easy-opening properties even if the heat sealing surface of the opening of the packaging container is a smooth packaging container or a projection container provided with projections. it can. In particular, even when performing high-temperature sealing at 170 ° C. or higher, it is possible to achieve a sealing property suitable for any container and an excellent easy-opening property.
　以下に実施例と比較例を挙げて、本発明を具体的に説明するが、本発明はこれらに限定されるものではない。なお、例中の部及び％は全て重量基準である。 本 The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these. All parts and percentages in the examples are on a weight basis.
（実施例１）
　ベース層（Ａ）にメタロセン触媒を用いた高密度ポリエチレン（密度０．９４０ｇ／ｃｍ３、メルトフローレート（以下、ＭＦＲ）（１９０℃、２１．１８Ｎ）０．４ｇ／１０ｍｉｎ、２７０℃溶融粘度６ｓｅｃ－１：３．６×１０３Ｐａ・ｓ，１２０ｓｅｃ－１：１．３×１０３Ｐａ・ｓ）（以下ｍ－ＨＤＰＥという）４０部と、低密度ポリエチレン（密度０．９３０ｇ／ｃｍ３、ＭＦＲ（１９０℃、２１．１８Ｎ）０．５ｇ／１０ｍｉｎ、２７０℃溶融粘度６ｓｅｃ－１：２．５×１０３Ｐａ・ｓ，１２０ｓｅｃ－１：６．２×１０２Ｐａ・ｓ）（以下ＬＤＰＥという）３０部及びメタロセン触媒を用いたポリエチレン（密度０．９４０ｇ／ｃｍ３、ＭＦＲ（１９０℃、２１．１８Ｎ）４．０ｇ／１０ｍｉｎ、２７０℃溶融粘度６ｓｅｃ－１：４．６×１０２Ｐａ・ｓ，１２０ｓｅｃ－１：４．６×１０２Ｐａ・ｓ）（以下ｍ－ＬＬＤＰＥ（１）という）３０部との混合物を用い、ヒートシール層（Ｂ）用の樹脂として、プロピレン－エチレンランダム共重合体（ＭＦＲ（２３０℃、２１．１８Ｎ）７ｇ／１０ｍｉｎ）（以下ＣＯＰＰという）５０部と、高密度ポリエチレン（密度０．９６ｇ／ｃｍ３、ＭＦＲ（１９０℃、２１．１８Ｎ）８ｇ／１０ｍｉｎ）（以下、ＨＤＰＥ（１）という）５０部との混合物を用い、共押出法により押出温度２７０℃でＴダイから（Ａ）／（Ｂ）の各層の厚さが４５μｍ／５μｍになるように押出し、４０℃の水冷金属冷却ロールで冷却し、樹脂層（Ａ）の濡れ張力が３９ｍＮ／ｍとなるようにコロナ放電処理を施した後、ロールに巻き取り、３５℃の熟成室で４８時間熟成させて、全厚が５０μｍの共押出積層フィルムを得た。 (Example 1)
High density polyethylene (density 0.940 g / cm 3 ) using a metallocene catalyst for the base layer (A), melt flow rate (hereinafter, MFR) (190 ° C., 21.18 N) 0.4 g / 10 min, 270 ° C. melt viscosity 6 sec -1 : 3.6 × 10 3 Pa · s, 120 sec −1 : 1.3 × 10 3 Pa · s) (hereinafter referred to as m-HDPE) 40 parts and low density polyethylene (density 0.930 g / cm 3 , MFR (190 ℃, 21.18N) 0.5g / 10min, 270 ℃ melt viscosity 6sec -1: 2.5 × 10 3 Pa · s, 120sec -1: 6.2 × 10 2 Pa · s) ( hereinafter LDPE polyethylene with) 30 parts of a metallocene catalyst that (density 0.940g / cm 3, MFR (190 ℃, 21.18N) 4.0g / 10min, 270 ℃ melt Degrees 6sec -1: 4.6 × 10 2 Pa · s, 120sec -1: 4.6 with a mixture of × 10 2 Pa · s) (hereinafter m-LLDPE (1) hereinafter) 30 parts, the heat seal layer As the resin for (B), 50 parts of a propylene-ethylene random copolymer (MFR (230 ° C., 21.18N) 7 g / 10 min) (hereinafter referred to as COPP) and high-density polyethylene (density 0.96 g / cm 3 , Using a mixture of MFR (190 ° C., 21.18N) 8 g / 10 min) (hereinafter referred to as HDPE (1)) and a co-extrusion method at an extrusion temperature of 270 ° C., a T-die was used to obtain (A) / (B). After extruding each layer so as to have a thickness of 45 μm / 5 μm, cooling with a water-cooled metal cooling roll at 40 ° C., and performing corona discharge treatment so that the wetting tension of the resin layer (A) becomes 39 mN / m. Wound into Lumpur, in ripening chamber 35 ° C. and aged for 48 hours, total thickness was obtained coextruded laminated film of 50 [mu] m.
（実施例２）
　ベース層（Ａ）用の樹脂混合物として、ｍ－ＨＤＰＥ５０部、ＬＤＰＥ２０部、ｍ－ＬＬＤＰＥ（１）３０部の混合物を用いた以外は実施例１と同様にして共押出積層フィルムを得た。 (Example 2)
A coextruded laminated film was obtained in the same manner as in Example 1, except that a mixture of 50 parts of m-HDPE, 20 parts of LDPE, and 30 parts of m-LLDPE (1) was used as the resin mixture for the base layer (A).
（実施例３）
　ベース層（Ａ）用の樹脂混合物として、ｍ－ＨＤＰＥ５０部、ＬＤＰＥ４０部、ｍ－ＬＬＤＰＥ（１）１０部の混合物を用いた以外は実施例１と同様にして共押出積層フィルムを得た。 (Example 3)
A coextruded laminated film was obtained in the same manner as in Example 1, except that a mixture of 50 parts of m-HDPE, 40 parts of LDPE, and 10 parts of m-LLDPE (1) was used as the resin mixture for the base layer (A).
（実施例４）
　ベース層（Ａ）用の樹脂混合物として、ｍ－ＨＤＰＥ４０部、ＬＤＰＥ３０部、ｍ－ＬＬＤＰＥ（１）２０部、サトウキビ由来の直鎖状低密度ポリエチレン（密度０．９１８ｇ／ｃｍ３、ＭＦＲ（１９０℃、２１．１８Ｎ）２．３ｇ／１０ｍｉｎ、２７０℃溶融粘度６ｓｅｃ－１：７．３×１０2Ｐａ・ｓ，１２０ｓｅｃ－１：６．０×１０2Ｐａ・ｓ）（以下バイオＬＬＤＰＥという）１０部の混合物を用いた以外は実施例１と同様にして共押出積層フィルムを得た。 (Example 4)
As the resin mixture for the base layer (A), 40 parts of m-HDPE, 30 parts of LDPE, 20 parts of m-LLDPE (1), a linear low-density polyethylene derived from sugarcane (density 0.918 g / cm 3 , MFR (190 ° C. , 21.18N) 2.3g / 10min, 270 ℃ melt viscosity 6sec -1: 7.3 × 10 2 Pa · s, 120sec -1: 6.0 × 10 2 Pa · s) ( hereinafter referred to as bio-LLDPE) 10 A coextruded laminated film was obtained in the same manner as in Example 1 except that the mixture of parts was used.
（実施例５）
　ベース層（Ａ）用の樹脂混合物として、ｍ－ＨＤＰＥ４０部、ＬＤＰＥ３０部、ｍ－ＬＬＤＰＥ（１）１０部、バイオＬＬＤＰＥ２０部の混合物を用いた以外は実施例１と同様にして共押出積層フィルムを得た。 (Example 5)
A co-extruded laminated film was prepared in the same manner as in Example 1 except that a mixture of 40 parts of m-HDPE, 30 parts of LDPE, 10 parts of m-LLDPE (1), and 20 parts of bio-LLDPE was used as a resin mixture for the base layer (A). Obtained.
（実施例６）
　ベース層（Ａ）用の樹脂混合物として、高密度ポリエチレン（密度０．９４６ｇ／ｃｍ３、メルトフローレート（以下、ＭＦＲ）（１９０℃、２１．１８Ｎ）０．１８ｇ／１０ｍｉｎ、２７０℃溶融粘度６ｓｅｃ－１：５．３×１０３Ｐａ・ｓ，１２０ｓｅｃ－１：１．２×１０３Ｐａ・ｓ）（以下ＨＤＰＥ（２）という）２０部と、メタロセン触媒を用いた直鎖低密度ポリエチレン（密度０．９２０ｇ／ｃｍ３、ＭＦＲ（１９０℃、２１．１８Ｎ）０．８５ｇ／１０ｍｉｎ、２７０℃溶融粘度６ｓｅｃ－１：２．５×１０３Ｐａ・ｓ，１２０ｓｅｃ－１：９．９×１０２Ｐａ・ｓ）（以下ｍ－ＬＬＤＰＥ（２）という）５０部及び高密度ポリエチレン（密度０．９６５ｇ／ｃｍ３、メルトフローレート（１９０℃、２１．１８Ｎ）０．７ｇ／１０ｍｉｎ、２７０℃溶融粘度６ｓｅｃ－１：２．６×１０３Ｐａ・ｓ，１２０ｓｅｃ－１：７．５×１０２Ｐａ・ｓ）（以下ＨＤＰＥ（３）という）３０部の混合物を用いた以外は実施例１と同様にして共押出積層フィルムを得た。 (Example 6)
As a resin mixture for the base layer (A), high-density polyethylene (density 0.946 g / cm 3 , melt flow rate (hereinafter, MFR) (190 ° C, 21.18 N) 0.18 g / 10 min, 270 ° C melt viscosity 6 sec) -1 : 5.3 × 10 3 Pa · s, 120 sec −1 : 1.2 × 10 3 Pa · s) (hereinafter referred to as HDPE (2)) and 20 parts of linear low-density polyethylene using a metallocene catalyst ( density 0.920g / cm 3, MFR (190 ℃, 21.18N) 0.85g / 10min, 270 ℃ melt viscosity 6sec -1: 2.5 × 10 3 Pa · s, 120sec -1: 9.9 × 10 2 Pa · s) (hereinafter m-LLDPE (2) hereinafter) 50 parts of high density polyethylene (density 0.965 g / cm 3, a melt flow rate (190 ° C., 21.18 ) 0.7g / 10min, 270 ℃ melt viscosity 6sec -1: 2.6 × 10 3 Pa · s, 120sec -1: 7.5 × 10 2 Pa · s) ( hereinafter referred to as HDPE (3)) of 30 parts of A coextruded laminated film was obtained in the same manner as in Example 1 except that the mixture was used.
（実施例７）
　ベース層（Ａ）用の樹脂混合物として、ＨＤＰＥ（２）２０部、ｍ－ＬＬＤＰＥ（２）４０部、ＨＤＰＥ（３）４０部、の混合物を用いた以外は実施例６と同様にして共押出積層フィルムを得た。 (Example 7)
Coextrusion was carried out in the same manner as in Example 6 except that a mixture of 20 parts of HDPE (2), 40 parts of m-LLDPE (2) and 40 parts of HDPE (3) was used as the resin mixture for the base layer (A). A laminated film was obtained.
（比較例１）
　ベース層（Ａ）のｍ－ＨＤＰＥ８０部、ｍ－ＬＬＤＰＥ（１）２０部の混合物を用いた以外は実施例１と同様にして共押出積層フィルムを得た。 (Comparative Example 1)
A coextruded laminated film was obtained in the same manner as in Example 1 except that a mixture of 80 parts of m-HDPE and 20 parts of m-LLDPE (1) of the base layer (A) was used.
（比較例２）
　ベース層（Ａ）のｍ－ＨＤＰＥ２０部、ＬＤＰＥ２０部、ｍ－ＬＬＤＰＥ（１）６０部の混合物を用いた以外は実施例１と同様にして共押出積層フィルムを得た。 (Comparative Example 2)
A coextruded laminated film was obtained in the same manner as in Example 1, except that a mixture of 20 parts of m-HDPE, 20 parts of LDPE and 60 parts of m-LLDPE (1) of the base layer (A) was used.
（比較例３）
　ベース層（Ａ）のｍ－ＬＬＤＰＥ（１）１００部の混合物を用いた以外は実施例１と同様にして共押出積層フィルムを得た。 (Comparative Example 3)
A coextruded laminated film was obtained in the same manner as in Example 1 except that a mixture of 100 parts of m-LLDPE (1) of the base layer (A) was used.
　実施例及び比較例にて得られた積層フィルム等につき、以下の評価を行った。得られた結果は下表のとおりである。 積 層 The following evaluations were performed on the laminated films and the like obtained in the examples and comparative examples. The results obtained are shown in the table below.
［溶融粘度の測定］
　東洋精機製キャピラリレオメーターを用いて、２７０℃でせん断速度を変化させたときの溶融粘度を測定した。 [Measurement of melt viscosity]
The melt viscosity when the shear rate was changed at 270 ° C. was measured using a capillary rheometer manufactured by Toyo Seiki.
［容器への開封性評価］
（９５φ突起容器）
　得られたフィルムのベース層（Ａ）側にウレタン系接着剤を使用して膜厚１５μｍの２軸延伸ナイロンフィルムをラミネートして、ラミネートフィルムを作成した。得られたラミネートフィルムを、９５φの突起容器を用いて、包装機でシールを行い、温度１７０、１８０℃、時間１．０秒間、荷重１６０ｋｇの条件でヒートシールサンプルを得た。このサンプルからプッシュプルゲージを用いて開封強度を測定した。合わせて、フィルムの材破の有無を確認し、裂けの発生が無いものを○、裂けが発生したものを×として表中に結果を記載した。
（７１φインジェクション容器）
　得られたフィルムのベース層（Ａ）側にウレタン系接着剤を使用して膜厚１５μｍの２軸延伸ナイロンフィルムをラミネートして、ラミネートフィルムを作成した。得られたラミネートフィルムを、９５φの突起容器を用いて、包装機でシールを行い、温度１７０、１８０℃、時間１．０秒間、荷重６４ｋｇの条件でヒートシールサンプルを得た。このサンプルからプッシュプルゲージを用いて開封強度を測定した。合わせて、フィルムの材破の有無を確認し、裂けの発生が無いものを○、裂けが発生したものを×として表中に結果を記載した。 [Evaluation of container openability]
(95φ projection container)
A 15 μm-thick biaxially stretched nylon film was laminated on the base layer (A) side of the obtained film using a urethane-based adhesive to prepare a laminated film. The obtained laminate film was sealed with a packaging machine using a projection container having a diameter of 95φ, and a heat-sealed sample was obtained under the conditions of a temperature of 170, 180 ° C., a time of 1.0 second, and a load of 160 kg. The opening strength of this sample was measured using a push-pull gauge. At the same time, the presence or absence of material breakage of the film was confirmed, and the result was described in the table as ○ when there was no tear, and × when there was a tear.
(71φ injection container)
A 15 μm-thick biaxially stretched nylon film was laminated on the base layer (A) side of the obtained film using a urethane-based adhesive to prepare a laminated film. The obtained laminated film was sealed with a packaging machine using a 95φ projection container, and a heat-sealed sample was obtained under the conditions of a temperature of 170, 180 ° C., a time of 1.0 second, and a load of 64 kg. The opening strength of this sample was measured using a push-pull gauge. At the same time, the presence or absence of material breakage of the film was confirmed, and the result was described in the table as ○ when there was no tear, and × when there was a tear.
［押出負荷評価］
　押出負荷は、φ５０ｍｍ押出機（Ｌ／Ｄ＝２８）で吐出量１２ｋｇ／ｈ、２７０℃で押出したときの押出機先端部の樹脂圧力で評価した。樹脂圧力が２０ＭＰａ未満で良好に押出可能であったものを◎、２０ＭＰａ以上２２ＭＰａ未満であったものを○、装置の圧力上限である２５ＭＰａに近い２２～２５ＭＰａであったものを×とした。 [Extrusion load evaluation]
The extrusion load was evaluated based on the resin pressure at the tip of the extruder when extruding at a discharge rate of 12 kg / h and 270 ° C. with a φ50 mm extruder (L / D = 28). When the resin pressure was less than 20 MPa and the resin could be extruded well, ◎ was given, when the resin pressure was 20 MPa or more and less than 22 MPa, and x was given when the resin pressure was 22 to 25 MPa, which is close to the upper limit of the pressure of the apparatus of 25 MPa.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　上記表から明らかなとおり、本発明の実施例１～５の積層フィルムは、成膜性が良好で、各種容器に対して高いシール温度でも好適なシール性と易開封性とを有するものであった。一方、比較例１～３のものは、良好な成膜性や高温シール温度下での好適な易開封性が得られないものであった。 As is clear from the above table, the laminated films of Examples 1 to 5 of the present invention have good film-forming properties and have suitable sealing properties and easy-opening properties even at high sealing temperatures for various containers. Was. On the other hand, in Comparative Examples 1 to 3, good film-forming properties and favorable easy-openability at a high sealing temperature were not obtained.

Claims (12)

  1. 　ベース層（Ａ）及びヒートシール層（Ｂ）を有する積層フィルムであって、ベース層（Ａ）がエチレン系樹脂を主たる樹脂成分として含有し、ベース層（Ａ）を形成する樹脂組成物のせん断速度６［ｓｅｃ－１］における２７０℃での溶融粘度が１．４×１０３［Ｐａ・ｓ］以上であり、せん断速度１２０［ｓｅｃ－１］における２７０℃での溶融粘度が１．０×１０３［Ｐａ・ｓ］以下であることを特徴とする積層フィルム。 A laminated film having a base layer (A) and a heat seal layer (B), wherein the base layer (A) contains an ethylene-based resin as a main resin component, and shearing of a resin composition forming the base layer (A) is performed. The melt viscosity at 270 ° C. at a speed of 6 [sec −1 ] is 1.4 × 10 3 [Pa · s] or more, and the melt viscosity at 270 ° C. at a shear rate of 120 [sec −1 ] is 1.0 × A laminated film characterized by being 10 3 [Pa · s] or less.
  2. 　ベース層（Ａ）を形成する樹脂組成物のメルトフローレートが０．１０～０．８０［ｇ／１０ｍｉｎ］である請求項１に記載の積層フィルム。 The laminated film according to claim 1, wherein the resin composition forming the base layer (A) has a melt flow rate of 0.10 to 0.80 [g / 10 min].
  3. 　ベース層（Ａ）がエチレン系樹脂として、せん断速度６［ｓｅｃ－１］における２７０℃での溶融粘度が３．０×１０３［Ｐａ・ｓ］以上、かつ、せん断速度１２０［ｓｅｃ－１］における２７０℃での溶融粘度が１．４×１０３［Ｐａ・ｓ］以下のエチレン系樹脂（ａ１）を含有する請求項１又は２に記載の積層フィルム。 When the base layer (A) is an ethylene resin, the melt viscosity at 270 ° C. at a shear rate of 6 [sec −1 ] is 3.0 × 10 3 [Pa · s] or more, and the shear rate is 120 [sec −1 ]. 3. The laminated film according to claim 1, further comprising an ethylene resin (a1) having a melt viscosity at 270 ° C. of 1.4 × 10 3 [Pa · s] or less.
  4. 　エチレン系樹脂（ａ１）のメルトフローレートが０．１０～０．７０［ｇ／１０ｍｉｎ］であり、
    　ベース層（Ａ）中のエチレン系樹脂（ａ１）の含有量が、ベース層（Ａ）に含まれる樹脂成分中の２０～６０質量％である請求項３に記載の積層フィルム。     The melt flow rate of the ethylene resin (a1) is 0.10 to 0.70 [g / 10 min];
    The laminated film according to claim 3, wherein the content of the ethylene-based resin (a1) in the base layer (A) is 20 to 60% by mass of the resin component contained in the base layer (A).
  5. 　ベース層（Ａ）が前記エチレン系樹脂（ａ１）以外のエチレン系樹脂として、せん断速度６［ｓｅｃ－１］における２７０℃での溶融粘度が２．３×１０３［Ｐａ・ｓ］以上、かつ、せん断速度１２０［ｓｅｃ－１］における２７０℃での溶融粘度が１．２×１０３［Ｐａ・ｓ］以下であるエチレン系樹脂（ａ２）を含有し、
    　ベース層（Ａ）中のエチレン系樹脂（ａ２）の含有量が、ベース層（Ａ）に含まれる樹脂成分中の２０～６０質量％である請求項３又は４に記載の積層フィルム。     When the base layer (A) is an ethylene resin other than the ethylene resin (a1), the melt viscosity at 270 ° C. at a shear rate of 6 [sec −1 ] is 2.3 × 10 3 [Pa · s] or more, and An ethylene resin (a2) having a melt viscosity at 270 ° C. at a shear rate of 120 [sec-1] of 1.2 × 10 3 [Pa · s] or less;
    The laminated film according to claim 3, wherein the content of the ethylene-based resin (a2) in the base layer (A) is 20 to 60% by mass of the resin component contained in the base layer (A).
  6. 　エチレン系樹脂（ａ２）のメルトフローレートが０．１０～１．０［ｇ／１０ｍｉｎ］である請求項５に記載の積層フィルム。 The laminated film according to claim 5, wherein the ethylene resin (a2) has a melt flow rate of 0.10 to 1.0 [g / 10 min].
  7. 　ベース層（Ａ）が前記エチレン系樹脂（ａ１）及び（ａ２）以外のエチレン系樹脂として、せん断速度１２０［ｓｅｃ－１］における２７０℃での溶融粘度が１．０×１０３［Ｐａ・ｓ］以下のエチレン系樹脂（ａ３）を含有し、
    　ベース層（Ａ）中のエチレン系樹脂（ａ３）の含有量が、ベース層（Ａ）に含まれる樹脂成分中の１０～４０質量％である請求項５又は６に記載の積層フィルム。     When the base layer (A) is an ethylene-based resin other than the ethylene-based resins (a1) and (a2), the melt viscosity at 270 ° C. at a shear rate of 120 [sec −1 ] is 1.0 × 10 3 [Pa · s]. ] It contains the following ethylene resin (a3),
    The laminated film according to claim 5, wherein the content of the ethylene-based resin (a3) in the base layer (A) is 10 to 40% by mass of the resin component contained in the base layer (A).
  8. 　エチレン系樹脂（ａ３）のメルトフローレートが０．５～８．０［ｇ／１０ｍｉｎ］である請求項７に記載の積層フィルム。 The laminated film according to claim 7, wherein the ethylene resin (a3) has a melt flow rate of 0.5 to 8.0 [g / 10 min].
  9. 　ヒートシール層（Ｂ）が凝集破壊により易開封性を有する易開封性ヒートシール層である請求項１～８のいずれかに記載の積層フィルム。 The laminated film according to any one of claims 1 to 8, wherein the heat-sealing layer (B) is an easy-opening heat-sealing layer having easy-opening properties due to cohesive failure.
  10. 　ベース層（Ａ）の厚みが総厚みの８０～９５％であり、ヒートシール層（Ｂ）の厚みが総厚みの５～２０％である請求項１～９のいずれかに記載の積層フィルム。 The laminated film according to any one of claims 1 to 9, wherein the thickness of the base layer (A) is 80 to 95% of the total thickness, and the thickness of the heat seal layer (B) is 5 to 20% of the total thickness.
  11. 　厚みが１５～１００μｍである請求項１～１０のいずれかに記載の積層フィルム。 積 層 The laminated film according to any one of claims 1 to 10, having a thickness of 15 to 100 µm.
  12. 　請求項１～１１のいずれか１項記載の共押出多層フィルムのベース層（Ａ）上に基材をラミネートしてなることを特徴とする蓋材。 (12) A lid material comprising a base material laminated on the base layer (A) of the co-extruded multilayer film according to any one of (1) to (11).
PCT/JP2019/024457 2018-07-03 2019-06-20 Layered film and lid WO2020008893A1 (en)

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JP2001310430A (en) * 2000-04-28 2001-11-06 Toray Plastic Films Co Ltd Easily openable composite film and easily openable container made of polyethylene
JP2005153324A (en) * 2003-11-26 2005-06-16 Dainippon Ink & Chem Inc Coextrusion multilayered film and laminated film
JP2005319583A (en) * 2001-09-28 2005-11-17 Showa Denko Plastic Products Co Ltd Laminated film, sealant film and package
JP2008114436A (en) * 2006-11-02 2008-05-22 Dainippon Printing Co Ltd Multilayered laminated film for lid material of packaging container
JP2012245767A (en) * 2011-05-31 2012-12-13 Kuraray Co Ltd Multilayer structure, container using the same, and method for manufacturing the same
JP2019000991A (en) * 2017-06-12 2019-01-10 東レフィルム加工株式会社 Easily opening composite film

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JP6291766B2 (en) 2013-09-25 2018-03-14 Dic株式会社 Easy-open laminated film, easy-open laminated film and lid
JP6993923B2 (en) * 2018-03-29 2022-01-14 ジェイフィルム株式会社 Sealant film and packaging material
JP7204334B2 (en) * 2018-03-30 2023-01-16 三井化学株式会社 Polyolefin composition, laminate and packaging material for electrochemical cells

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JPH10315405A (en) * 1997-05-22 1998-12-02 Sekisui Chem Co Ltd Sealant film
JP2001310430A (en) * 2000-04-28 2001-11-06 Toray Plastic Films Co Ltd Easily openable composite film and easily openable container made of polyethylene
JP2005319583A (en) * 2001-09-28 2005-11-17 Showa Denko Plastic Products Co Ltd Laminated film, sealant film and package
JP2005153324A (en) * 2003-11-26 2005-06-16 Dainippon Ink & Chem Inc Coextrusion multilayered film and laminated film
JP2008114436A (en) * 2006-11-02 2008-05-22 Dainippon Printing Co Ltd Multilayered laminated film for lid material of packaging container
JP2012245767A (en) * 2011-05-31 2012-12-13 Kuraray Co Ltd Multilayer structure, container using the same, and method for manufacturing the same
JP2019000991A (en) * 2017-06-12 2019-01-10 東レフィルム加工株式会社 Easily opening composite film

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