WO2024058167A1 - Packaging material - Google Patents

Packaging material Download PDF

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Publication number
WO2024058167A1
WO2024058167A1 PCT/JP2023/033180 JP2023033180W WO2024058167A1 WO 2024058167 A1 WO2024058167 A1 WO 2024058167A1 JP 2023033180 W JP2023033180 W JP 2023033180W WO 2024058167 A1 WO2024058167 A1 WO 2024058167A1
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WO
WIPO (PCT)
Prior art keywords
film
layer
packaging material
resin
heat
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PCT/JP2023/033180
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French (fr)
Japanese (ja)
Inventor
敦史 山崎
稚登 戸松
充裕 柏
徹 今井
Original Assignee
東洋紡株式会社
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Publication of WO2024058167A1 publication Critical patent/WO2024058167A1/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 packaging material used in the field of packaging foods, pharmaceuticals, industrial products, etc. More specifically, the present invention relates to an environmentally friendly laminated packaging material that has excellent gas barrier properties, straight cutting properties, elasticity, and convenience.
  • packaging materials made of the same recyclable material that is, to make them monomaterials.
  • materials for monomaterialization for example, polyester-based or polyolefin-based materials are being investigated.
  • Patent Document 1 In the design of polyester-based monomaterial packaging materials, a polyester-based sealant with improved low adsorption and heat resistance has been disclosed as an alternative to conventional polyolefin-based sealants (see, for example, Patent Document 1).
  • the sealant of Patent Document 1 satisfies heat sealability and heat resistance by separating a layer having heat sealability and other layers and controlling the raw material compositions of these layers separately.
  • heat sealability there is a problem that the sealing strength is inferior to that of polyolefin sealants, and in terms of heat resistance, it is currently unable to withstand harsh treatments such as boiling and retort processing. Met.
  • a polyolefin heat-sealing resin can be used as a sealant, which has the advantage of ensuring sufficient heat-sealability compared to the above-mentioned polyester sealant.
  • the sealant needs to have a certain degree of thickness in order to exhibit sufficient sealing properties, and occupies a large proportion of the package. This point is also a major reason why polyolefin-based monomaterial packaging material design is being promoted.
  • polyolefin packaging materials have a problem of inferior gas barrier performance compared to conventional packaging having barrier performance.
  • polypropylene film has water vapor barrier properties, it does not have sufficient water vapor barrier properties compared to, for example, transparent inorganic vapor-deposited polyester films, which are generally considered to have excellent water vapor barrier properties, and it also has very poor oxygen barrier properties. there were.
  • a film is used in which a polypropylene film is laminated with a polymer resin composition that is generally said to have relatively high oxygen barrier properties, such as polyvinyl alcohol, ethylene vinyl alcohol copolymer, polyvinylidene chloride resin, and polyacrylonitrile.
  • a polymer resin composition that is generally said to have relatively high oxygen barrier properties, such as polyvinyl alcohol, ethylene vinyl alcohol copolymer, polyvinylidene chloride resin, and polyacrylonitrile.
  • gas barrier coating films made using the above-mentioned polymeric resin compositions of polyvinyl alcohol or ethylene vinyl alcohol copolymers are highly dependent on humidity, so gas barrier properties deteriorate under high humidity conditions, and boiling or retorting It also did not have the heat and humidity resistance to withstand sterilization treatments such as sterilization.
  • polyvinylidene chloride resin and polyacrylonitrile have low humidity dependence, they have problems such as insufficient barrier value as an absolute value and a high risk of generating harmful substances when disposed of or incinerated. there were.
  • the polypropylene film used does not have sufficient heat resistance, and the added heat during coating, printing, laminating, and sterilization processing causes the film to expand and contract, leading to wrinkles in appearance and a decline in performance. .
  • Patent Document 5 With regard to improving the gas barrier properties of polypropylene films, attempts have been made to develop stable gas barrier properties without humidity dependence by laminating inorganic thin films (for example, Patent Document 5). However, there were problems such as the absolute value of gas barrier performance (particularly oxygen barrier property) being inferior to conventional polyester vapor-deposited films, and the film being more susceptible to physical damage than the above-mentioned coat-type barrier film. Barrier materials made by vapor-depositing polyolefin sealants have also been studied (for example, Patent Document 6), but although they exhibit water vapor barrier performance, they have problems such as insufficient oxygen barrier properties.
  • the direction of the molecular orientation axis of the base film can be made the same as the tearing direction of the packaging bag, such a problem will not occur.
  • the direction of the molecular orientation axis at the widthwise central portion of the produced wide stretched film coincides with the running direction of the film, allowing it to be torn parallel to one side of the packaging bag.
  • the direction of the molecular orientation axis is tilted, and the tearing direction of the packaging bag is tilted. It is not realistic to completely avoid procuring a base film that uses the edges of the film in the width direction, and as the production speed and width of the base film increases, the degree of distortion will become even greater than before. It tends to get bigger. In contrast, attempts have been made to solve these problems by devising a polyolefin heat-sealing resin that is laminated with the base film.
  • a film obtained by uniaxially stretching a polyolefin resin sheet containing an ethylene-propylene block copolymer and an ethylene-propylene copolymer at a ratio of 3.0 times or less is known as a heat-sealable resin with improved cuttability.
  • a heat-sealable resin with improved cuttability For example, see Examples 1 and 2 of Patent Document 7.
  • tear strength there was still room for improvement in tear strength, and there was a problem in that tearing was likely to occur.
  • a film made of a different material other than polyolefin was used as the base layer, and aluminum foil was used as the barrier layer, which could not be recycled.
  • JP 2017-165059 Publication Japanese Patent Application Publication No. 2000-52501 Japanese Patent Application Publication No. 4-359033 JP2003-231221A International Publication No. 2017/221781 Patent No. 3318479 Patent No. 5790497
  • the object of the present invention is to create a packaging that can form a laminate structure made of a resin type that has a low environmental impact, and that also has all three performances required of a packaging material: gas barrier properties, cutability, and firmness.
  • the goal is to provide materials.
  • the present inventors have developed a laminated film in which a predetermined gas barrier layer tailored to the required performance is laminated on a base film, thereby greatly improving gas barrier performance, and further controlling the heating elongation rate of the laminated film. It is possible to ensure heat resistance against various processing and sterilization treatments, and finally, by laminating the resin layer with the above-mentioned base film as a heat-sealable resin film that has excellent straight cutability and has a strong feel, it is environmentally friendly and convenient.
  • the present invention was completed by discovering that it is possible to provide a packaging material with high properties.
  • a packaging material comprising at least one base film containing a polyolefin resin as a constituent component and a heat-sealable resin film, At least one of the base films is a laminated base film having a gas barrier layer, At least one of the base films peeled from the packaging material has a heating elongation rate at 130°C measured by a thermomechanical analyzer of 6% or less in both the MD direction and the TD direction, The straight cutting property of the packaging material is 10 mm or less in the MD direction or the TD direction, and the loop stiffness value is 140 mN/25 mm or more, A packaging material characterized by an oxygen permeability of 60 ml/m 2 ⁇ d ⁇ MPa or less under a 23° C.
  • the heat-sealable resin film contains a propylene- ⁇ olefin random copolymer, and further contains at least one component selected from an ethylene-propylene copolymer elastomer, an ethylene-butene copolymer elastomer, and a propylene-butene copolymer elastomer.
  • the gas barrier layer is an inorganic thin film layer formed from a material selected from the group consisting of aluminum, aluminum oxide, silicon oxide, and a composite oxide of silicon oxide and aluminum oxide. Or 2. Packaging materials listed in. 4. 1.
  • the gas barrier layer is a coating layer containing as a constituent component a resin selected from the group consisting of polyvinyl alcohol resin, polyester resin, and polyurethane resin. ⁇ 3. Packaging materials listed in any of the above. 5. 1. An anchor coat layer is laminated between the base film and the gas barrier layer. ⁇ 4. Packaging materials listed in any of the above. 6. 1. A protective layer is laminated on the gas barrier layer. ⁇ 5. Packaging materials listed in any of the above. 7. 1. characterized in that two or more of the base films are used; ⁇ 6. Packaging materials listed in any of the above. 8. 1. The polyolefin resin constituting the base film contains 1% by mass or more and 25% by mass or less of a plant-derived polyethylene resin. ⁇ 7. Packaging materials listed in any of the above. 9.
  • the present inventors have been able to provide a packaging material that has the required performance such as barrier properties, cuttability, and elasticity required for packaging materials, while being environmentally friendly.
  • the packaging material of the present invention is a packaging material having at least one base film containing a polyolefin resin as a constituent component and a heat-sealable resin film, wherein at least one of the base films has a gas barrier layer.
  • at least one of the base films peeled from the packaging material has a heat elongation rate of 6% or less at 130°C in both the MD direction and the TD direction as measured by a thermomechanical analyzer. and the packaging material has straight cutability of 10 mm or less in the MD direction or TD direction, a loop stiffness value of 140 mN/25 mm or more, and an oxygen permeability of 60 ml/m 2 in an environment of 23° C.
  • x 65% RH. ⁇ It is a packaging material characterized by having a pressure of d ⁇ MPa or less.
  • the base film has a polyolefin resin as a main constituent component, and the above-mentioned "main constituent component” refers to containing 50% by mass or more in the constituent components, and preferably The content is 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more.
  • the packaging material of the present invention includes a base film containing a polyolefin resin as a constituent component.
  • the base film is preferably a base film containing a polypropylene resin as a main component (hereinafter referred to as a polypropylene resin film), and more preferably a stretched film.
  • the stretched polypropylene resin film used as the base film in the present invention is preferably a biaxially stretched film.
  • the biaxially oriented polypropylene resin film a known biaxially oriented polypropylene resin film can be used, and the raw materials, mixing ratio, etc. thereof are not particularly limited.
  • polypropylene homopolymers propylene homopolymers
  • known additives such as antioxidants, antistatic agents, plasticizers, etc. may be added, and for example, petroleum resins, terpene resins, etc. may be added.
  • the polypropylene resin constituting the base film is preferably a propylene homopolymer that does not substantially contain comonomers other than propylene. It is preferable that the amount is 0.5 mol% or less in all the constituent monomers.
  • the upper limit of the comonomer amount is more preferably 0.3 mol%, and even more preferably 0.1 mol%. Within the above range, crystallinity is improved, dimensional changes at high temperatures are reduced, and heat resistance is improved. Note that a comonomer may be included in a trace amount within a range that does not significantly reduce crystallinity.
  • the biaxially oriented polypropylene resin film used in the present invention may be a single layer film or a laminated film, for example, a laminated film comprising a base layer and one or more surface layers. It is preferable to use a laminated film (surface layer/base layer/surface layer) having surface layers on both sides of the base layer.
  • a laminated film is preferable, and the type of laminate, number of layers, lamination method, etc. are not particularly limited, and can be arbitrarily selected from known methods.
  • the lamination strength and adhesive strength of coating agents, etc. can be improved. is preferred.
  • melt flow rate is used as a polypropylene resin constituting the surface layer of the base film.
  • a mixture of two or more types of polypropylene resins having different properties may be used.
  • melt flow rate MFR
  • MFR melt flow rate
  • each polypropylene resin a polypropylene homopolymer containing no copolymerization component, and a polypropylene resin copolymerized with ethylene and/or an ⁇ -olefin having 4 or more carbon atoms at 5.0 mol% or less can be used.
  • the copolymerization component of the copolymerized polypropylene resin is preferably 4.0 mol% or less, more preferably 3.5 mol% or less.
  • the copolymerization component of the copolymerized polypropylene resin is preferably 1.0 mol% or more, more preferably 1.5 mol% or more, even more preferably 2.0 mol% or more, and particularly preferably 2.5 mol% or more.
  • Examples of the ⁇ -olefin having 4 or more carbon atoms include 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene. Furthermore, maleic acid or the like having polarity may be used as another copolymerization component.
  • the lower limit of the xylene soluble content of the polypropylene resin constituting the base film is preferably 0.1% by mass.
  • the upper limit of the xylene soluble content is preferably 7% by mass, more preferably 6% by mass, and still more preferably 5% by mass. The above range is preferable because crystallinity improves, dimensional changes during heating become smaller, and heat resistance improves.
  • the lower limit of the melt flow rate (MFR) (230°C, 2.16 kgf) of the polypropylene resin is preferably 0.5 g/10 minutes.
  • the lower limit of MFR is more preferably 1.0 g/10 minutes, still more preferably 2.0 g/10 minutes, particularly preferably 4.0 g/10 minutes, and most preferably 6.0 g/10 minutes. It is. Within the above range, the mechanical load is small and extrusion and stretching become easy.
  • the upper limit of MFR is preferably 20 g/10 minutes.
  • the upper limit of MFR is more preferably 17 g/10 minutes, still more preferably 16 g/10 minutes, particularly preferably 15 g/10 minutes.
  • a range within the above range is preferable because it facilitates stretching, reduces thickness unevenness, makes it easier to raise the stretching temperature and heat setting temperature, reduces dimensional changes during heating, and improves heat resistance.
  • the base film may be a uniaxially stretched film in the longitudinal direction (MD direction) or the transverse direction (TD direction), but is preferably a biaxially stretched film.
  • MD direction longitudinal direction
  • TD direction transverse direction
  • the stretching method include a simultaneous biaxial stretching method and a sequential biaxial stretching method, but the sequential biaxial stretching method is preferred from the viewpoint of improving flatness, dimensional stability, thickness unevenness, and the like.
  • polypropylene resin is heated and melted using a single-screw or twin-screw extruder at a resin temperature of 200°C or higher and 280°C or lower, formed into a sheet using a T-die, and then heated at a temperature of 10°C or higher and 100°C or higher.
  • An unstretched sheet is obtained by extrusion onto a chill roll at a temperature of 0.degree. C. or below.
  • roll stretching is performed in the longitudinal direction (MD direction) at 120° C. or more and 165° C. or less to 3.0 times or more and 8.0 times or less, and then, after preheating with a tenter, it is stretched in the transverse direction (TD direction) at 155° C.
  • MD direction longitudinal direction
  • TD direction transverse direction
  • heat setting treatment can be performed at a temperature of 165° C. or more and 175° C. or less while allowing relaxation of 1% or more and 15% or less.
  • the heating elongation rate of the base film at 130°C measured by a thermomechanical analyzer is 10% or less in both the MD direction and the TD direction. .
  • the heat elongation rate in the MD direction and the TD direction at 130°C is preferably 9.5% or less, more preferably 9.0% or less, even more preferably 8.5% or less, and the lower limit is preferably 0%. .
  • the laminated film may be deformed by the heat during tension loading, resulting in a decrease in gas barrier properties, or the film may undergo dimensional changes, resulting in a decrease in appearance quality.
  • the heating elongation rate is a value measured by a thermomechanical analyzer (TMA) method, and more specifically by the method described in Examples.
  • the upper limit of the stretching temperature in the longitudinal direction (MD) is preferably -7°C, more preferably Tm -10°C, and even more preferably Tm -12°C. If it is within the above range, the heating elongation rate can be easily reduced, and since it is difficult to fuse to the stretching rolls and stretch, the quality is less likely to deteriorate.
  • the stretching in the longitudinal direction may be performed in two or more stages using three or more pairs of stretching rolls. By dividing into multiple stages, distortion during stretching can be reduced, making it easier to reduce the heating elongation rate.
  • the upper limit of the stretching ratio in the width direction (TD) is preferably 15 times, more preferably 12 times, and even more preferably 10 times. If it exceeds the above, the heating elongation rate will be high and it will be easy to break during stretching.
  • the lower limit of the TD stretching temperature is preferably 150°C, more preferably 152°C, still more preferably 154°C, particularly preferably 156°C. When the temperature is 150° C. or higher, the stretching is done in a sufficiently softened state, so it is easy to reduce the heating elongation rate.
  • the upper limit of the TD stretching temperature is preferably 164°C, more preferably 162°C, and still more preferably 160°C. In order to lower the heating elongation rate, higher temperatures are preferred.
  • the lower limit of the heat setting temperature after stretching in the width direction (TD) is preferably 168°C, more preferably 170°C, and still more preferably 173°C.
  • the temperature is 168° C. or higher, the heating elongation rate is difficult to increase, and there is no need to perform a long treatment in order to lower the heating elongation rate.
  • the lower limit of the relaxation rate is preferably 2%, more preferably 3%. If it is less than the above, the heating elongation rate may become high.
  • the film produced in the above process can be wound up into a roll and then annealed off-line.
  • the base film used in the present invention preferably contains particles to form protrusions on the film surface in order to impart handling properties (for example, winding properties after lamination).
  • particles to be included in the film include inorganic particles such as silica, kaolinite, talc, calcium carbonate, zeolite, and alumina, and heat-resistant polymer particles such as acrylic, PMMA, nylon, polystyrene, polyester, and benzoguanamine/formalin condensate. It will be done. From the viewpoint of transparency, the content of particles in the film is preferably small, for example, preferably 1 ppm or more and 1000 ppm or less.
  • the average particle diameter of the particles is preferably 1.0 to 3.0 ⁇ m, more preferably 1.0 to 2.7 ⁇ m.
  • the method for measuring the average particle size is to take a photograph with a scanning electron microscope, measure the Feret diameter in the horizontal direction using an image analyzer, and display the average value. Furthermore, from the viewpoint of transparency, it is preferable to select particles having a refractive index similar to that of the resin used.
  • we also add antioxidants, ultraviolet absorbers, antistatic agents, pigments, lubricants, nucleating agents, adhesives, antifogging agents, flame retardants, and antiblocking agents. , an inorganic or organic filler, etc. may be included.
  • the present invention aims to improve the mechanical properties of the base film, improve the adhesion with the ink layer and adhesive layer laminated on the gas barrier coating layer, reduce environmental burden, etc.
  • Other resins can be used as long as they do not impair the purpose. Examples include polyethylene resins, polypropylene resins different from those mentioned above, random copolymers that are copolymers of propylene and ethylene and/or ⁇ -olefins having 4 or more carbon atoms, and various elastomers.
  • the polyethylene resin that can be used for the base film in the present invention is a resin whose main component is ethylene, such as high-pressure low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, and high-density polyethylene.
  • ethylene such as high-pressure low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, and high-density polyethylene.
  • ⁇ -olefins such as propylene, butene-1, pentene-1, hexene-1, 3-methylbutene-1, 4-methylpentene-1, octene-1, etc.
  • Crystalline or low-crystalline to non-crystalline random or block copolymers with monomers such as vinyl acetate, (meth)acrylic acid, (meth)acrylic esters, or mixtures thereof can be used. .
  • the polyethylene resin is contained in an amount of 1% by mass or more and 25% by mass or less based on the total of 100% of the polypropylene resin and polyethylene resin constituting the base material.
  • the content is 1% by mass or more, heat seal strength, blocking resistance, and antifogging properties are improved. More preferably, it is 5% by mass or more, and still more preferably 8% by mass or more.
  • the content is 20% by mass or less, rigidity can be easily maintained. More preferably it is 18% by mass or less, and still more preferably 15% by mass or less.
  • the melting point of the polyethylene resin is preferably in the range of 100°C or more and 135°C or less, more preferably 105°C or more and 130°C or less, from the viewpoint of heat resistance, transparency, mechanical properties, and film formability. Further, the density is measured according to JIS K7112, and is preferably 0.90 g/cm 3 or more and 0.94 g/cm 3 or less, more preferably 0.91 g/cm 3 or more and 0.94 g/cm 3 or less.
  • the melt flow rate (MFR) (190°C, 2.16 kgf) of the polyethylene resin is preferably 0.5 g/10 minutes or more, more preferably 1 g/10 minutes or more, even more preferably 2 g/10 minutes or more, From the viewpoint of further stabilizing moldability, it is preferably 20 g/10 minutes or less, more preferably 15 g/10 minutes or less, even more preferably 10 g/10 minutes or less.
  • the biobased degree of the polyethylene resin measured in accordance with ISO 16620 is preferably 50% or more and 100% or less, preferably 70% or more and 100% or less, and 80% or more and 100% or less. is even more preferable.
  • the thickness of the base film is arbitrarily set according to each use, but the lower limit is preferably 2 ⁇ m or more, more preferably 3 ⁇ m or more, and still more preferably 4 ⁇ m or more.
  • the upper limit of the thickness is preferably 300 ⁇ m or less, more preferably 250 ⁇ m or less, even more preferably 200 ⁇ m or less, particularly preferably 150 ⁇ m or less.
  • the thickness is thin, handling properties tend to be poor.
  • the thickness is large, not only is there a problem in terms of cost, but also when the film is wound into a roll and stored, poor flatness due to curling tends to occur.
  • the haze of the base film of the present invention is preferably transparent from the viewpoint of visibility of the contents, specifically preferably 6% or less, more preferably 5% or less, and even more preferably 4%. It is as follows. Haze tends to worsen, for example, when the stretching temperature and heat setting temperature are too high, when the cooling roll (CR) temperature is high and the cooling rate of the stretched raw sheet is slow, and when the low molecular weight is too high. It can be controlled within the above range by adjusting .
  • the base film layer in the present invention may be subjected to corona discharge treatment, glow discharge treatment, flame treatment, surface roughening treatment, as long as the object of the present invention is not impaired. It may be treated, printed, decorated, etc. It is generally preferable to use a resin with good adhesion such as polyurethane or polyester for the anchor coat, but the anchor coat layer for improving the barrier in the present invention will be described later.
  • the packaging material of the present invention requires at least one base film having a gas barrier layer, but by bonding two or more base films together, it is expected that the toughness and gas barrier performance of the packaging material will be improved. more preferable.
  • toughness by using two sheets of biaxially stretched polypropylene film, which generally has high puncture strength, for example, two sheets of different materials such as polyester film and polyamide film, which are widely used as packaging materials, can be used. It becomes possible to design a packaging material that is comparable to the configuration used.
  • gas barrier properties by using two base films, the film located in the middle is less susceptible to the effects of the external environment, such as temperature, humidity, and external bending, resulting in more stable gas barrier performance. can demonstrate. In this sense, when two base films are used, it is particularly preferable that the coating layer or inorganic thin film layer having gas barrier performance is laminated on the intermediate film.
  • At least one of the base films needs to be a laminated base film having a gas barrier layer.
  • the gas barrier layer it is preferable to laminate either a coating layer (A) containing an organic substance as a main constituent or an inorganic thin film layer (B) containing an inorganic substance as a main constituent, which will be described later.
  • an anchor coat (C) and a protective layer (D), which will be described later, can also be laminated together.
  • a coating layer (A) can be provided as a gas barrier layer.
  • the provision of the coating layer (A) will increase the cost due to the increase in the number of steps, and that depending on the thickness of the film, there will be a burden on the environment, such as making it difficult to recycle. There is.
  • the coating amount of the coating layer (A) is preferably 0.10 to 0.70 (g/m 2 ).
  • the lower limit of the adhesion amount of the coating layer (A) is preferably 0.15 (g/m 2 ) or more, more preferably 0.20 (g/m 2 ) or more, and even more preferably 0.25 (g/m 2 ) . ) or more, and the upper limit is preferably 0.65 (g/m 2 ) or less, more preferably 0.60 (g/m 2 ) or less, even more preferably 0.55 (g/m 2 ) or less.
  • the gas barrier properties will improve, but the cohesive force inside the coating layer will be insufficient and the uniformity of the coating layer will also decrease. , unevenness (increased haze, whitening) or defects may occur in the coat appearance, and gas barrier properties and adhesion properties may not be sufficiently developed. In addition, in terms of processability, blocking may occur due to the thick film. Furthermore, there is a concern that it will have a negative impact on the recyclability of the film, and the amount of raw materials, solvents, etc. used will increase, increasing the environmental burden. On the other hand, if the amount of the coating layer (A) deposited is less than 0.10 (g/m 2 ), sufficient gas barrier properties and interlayer adhesion may not be obtained.
  • the resin composition used for the coating layer (A) formed on the surface of the laminated film of the present invention preferably contains a resin selected from the group consisting of polyvinyl alcohol resin, polyester resin, and polyurethane resin as a constituent component.
  • a resin selected from the group consisting of polyvinyl alcohol resin, polyester resin, and polyurethane resin as a constituent component.
  • a polyvinyl alcohol polymer (resin) polyvinyl alcohol polymer (resin).
  • Polyvinyl alcohol-based polymers have vinyl alcohol units as their main constituents, and can be expected to significantly improve barrier performance due to high cohesiveness due to hydrogen bond structures.
  • the degree of polymerization and saponification of the polyvinyl alcohol polymer are determined based on the desired gas barrier properties and the viscosity of the aqueous coating solution.
  • the degree of polymerization coating is difficult due to the high viscosity of the aqueous solution and the tendency to gel, so a degree of polymerization of 2,600 or less is preferable from the viewpoint of workability of coating.
  • the degree of saponification if it is less than 90%, sufficient oxygen gas barrier properties under high humidity cannot be obtained, and if it exceeds 99.7%, it is difficult to prepare an aqueous solution and it is easy to gel, making it unsuitable for industrial production. Therefore, the degree of saponification is preferably 90 to 99.7%, more preferably 93 to 99%.
  • various copolymerized or modified polyvinyl alcohol polymers such as polyvinyl alcohol polymers copolymerized with ethylene and polyvinyl alcohol polymers modified with silanol, are also used within the range that does not impair processability or productivity. can.
  • the coating layer (A) of the present invention may contain an inorganic layered compound.
  • the presence of the inorganic layered compound can be expected to have a labyrinth effect against gas, improving gas barrier properties. Furthermore, by adding an inorganic layered compound, the humidity dependence of gas barrier properties can be suppressed.
  • the material include clay minerals (including synthetic products thereof) such as smectite, kaolin, mica, hydrotalcite, and chlorite.
  • scaly silica or the like can be used as an inorganic layered compound. These may be used alone or in combination of two or more.
  • smectite is particularly preferred because it has a high effect of improving water vapor barrier properties.
  • the inorganic layered compound one in which metal ions having redox properties, particularly iron ions, are present is preferable.
  • montmorillonite which is a type of smectite, is preferred from the viewpoint of coating suitability and gas barrier properties.
  • known ones that have been conventionally used in gas barrier agents can be used.
  • the following general formula: (X, Y) 2 ⁇ 3 Z 4 O 10 (OH) 2 ⁇ mH 2 O ⁇ (W ⁇ ) (In the formula, X represents Al, Fe(III), or Cr(III). Y represents Mg, Fe(II), Mn(II), Ni, Zn, or Li. Z represents Si , or Al.
  • W represents K, Na, or Ca. H 2 O represents interlayer water. m and ⁇ represent positive real numbers.) Among these, those in which W in the formula is Na are preferred because they cleave in an aqueous medium.
  • the size and shape of the inorganic layered compound are not particularly limited, but the particle diameter (length) is preferably 5 ⁇ m or less, more preferably 4 ⁇ m or less, and still more preferably 3 ⁇ m or less. If the particle size is larger than 5 ⁇ m, the dispersibility will be poor, and as a result, the coatability and coat appearance of the coating layer (A) may deteriorate. On the other hand, its aspect ratio is 50 to 5,000, more preferably 100 to 4,000, still more preferably 200 to 3,000.
  • the blending ratio of the resin composition and the inorganic layered compound in the coating layer of the present invention is preferably 75/25 to 35/65 (mass%), more preferably 70/30 to 40/60 (mass%), even more preferably 65 /35 to 45/55 (mass%). If the blending ratio of the inorganic layered compound is less than 25%, the barrier performance may be insufficient. On the other hand, if it is more than 65%, there is a risk that the dispersibility will deteriorate, resulting in poor coating properties and poor adhesion.
  • the coating layer (A) of the present invention may contain various crosslinking agents for the purpose of improving the cohesive force and heat-and-moisture adhesive properties of the film, within a range that does not impair gas barrier properties or productivity.
  • the crosslinking agent include silicon-based crosslinking agents, oxazoline compounds, carbodiimide compounds, epoxy compounds, and isocyanate compounds.
  • silicon-based cross-linking agents are particularly preferred from the viewpoint of blending a silicon-based cross-linking agent to cause a cross-linking reaction with a resin composition having a hydroxyl group or an inorganic thin film layer, and improving water-resistant adhesion.
  • Commonly used silicon-based crosslinking agents include metal alkoxides and silane coupling agents.
  • the metal alkoxide is a compound represented by the general formula M(OR) n (M: metal such as Si or Al, R: alkyl group such as CH 3 or C 2 H 5 ).
  • M metal such as Si or Al
  • R alkyl group such as CH 3 or C 2 H 5
  • Specific examples include tetraethoxysilane [Si(OC 2 H 5 ) 4 ], triisopropoxyaluminum [Al[OCH(CH 3 ) 2 ] 3 ], and the like.
  • silane coupling agents include those having an epoxy group such as 3-glycidoxypropyltrimethoxysilane, those having an amino group such as 3-aminopropyltrimethoxysilane, and mercapto groups such as 3-mercaptopropyltrimethoxysilane.
  • Examples include those having an isocyanate group such as 3-isocyanatepropyltriethoxysilane, and tris-(3-trimethoxysilylpropyl)isocyanurate.
  • an oxazoline compound, a carbodiimide compound, an epoxy compound, etc. may be used in combination. However, if recyclability is important, consideration must be given to the amount of crosslinking agent added.
  • the blending amount is preferably 0.05 to 4.00% by mass in the coating layer, more preferably 0.10 to 3.50% by mass, even more preferably 0.15 to 3.00% by mass. Mass%.
  • the film will be cured and the cohesive force will be improved, resulting in a film with excellent water-resistant adhesion. If the blending amount exceeds 4.00% by mass, there is a risk that the amount of uncrosslinked portions will increase, or that curing will progress too much and the film will become hard, resulting in a decrease in adhesion. On the other hand, if the blending amount is less than 0.05% by mass, sufficient cohesive force may not be obtained.
  • the film haze after lamination of the coating layer (A) is preferably 20% or less, more preferably 18% or less, still more preferably 16% or less, from the viewpoint of visibility of the contents. If the haze is greater than 20%, in addition to greatly deteriorating transparency, there is a concern that surface irregularities may be affected, which may lead to poor appearance in subsequent printing steps and the like. Note that the haze can be adjusted by changing the composition ratio, solvent conditions, film thickness, etc. of the coating layer (A). Here, the haze was evaluated in accordance with JIS K7136 using a turbidity meter (manufactured by Nippon Denshoku Kogyo Co., Ltd., NDH2000).
  • the coating method of the resin composition for the coating layer (A) is not particularly limited as long as it is a method of coating the film surface to form a layer.
  • conventional coating methods such as gravure coating, reverse roll coating, wire bar coating, and die coating can be employed.
  • Pre-drying temperature is preferably 80 to 110°C, more preferably 85 to 105°C, still more preferably 90 to 100°C. If the pre-drying temperature is less than 80°C, there is a risk that the coating layer will be insufficiently dried. Furthermore, if the pre-drying temperature is higher than 110° C., drying will proceed before the coating layer is wetted and spread, which may result in poor appearance.
  • the main drying temperature is preferably 110 to 140°C, more preferably 115 to 135°C, and even more preferably 120 to 130°C. If the main drying temperature is less than 110°C, the film formation of the coating layer (A) will not proceed, resulting in a decrease in cohesive force and adhesiveness, and as a result, there is a possibility that the barrier properties will also be adversely affected. If the temperature exceeds 140°C, too much heat is applied to the film, which may cause the film to become brittle or cause wrinkles due to heat shrinkage to increase.
  • the preferred drying time for pre-drying is 3.0 to 10.0 seconds, more preferably 3.5 to 9.5 seconds, even more preferably 4.0 to 9.0 seconds. Further, the preferred drying time for the main drying is 3.0 to 10.0 seconds, more preferably 3.5 to 9.5 seconds, and still more preferably 4.0 to 9.0 seconds.
  • additional heat treatment for 1 to 4 days at as low a temperature as possible, specifically in the temperature range of 40 to 60°C may be helpful in promoting the formation of the coating layer (A). Even more effective.
  • an inorganic thin film layer (B) can be provided on the surface of the base film as a gas barrier layer.
  • the inorganic thin film layer (B) is a thin film made of metal or inorganic oxide.
  • the material forming the inorganic thin film layer is not particularly limited as long as it can be made into a thin film, but it must be a material selected from the group consisting of aluminum, aluminum oxide, silicon oxide, and a composite oxide of silicon oxide and aluminum oxide. is preferred, and from the viewpoint of gas barrier properties, inorganic oxides such as silicon oxide (silica), aluminum oxide (alumina), and composite oxides and mixtures of silicon oxide and aluminum oxide are preferably mentioned.
  • a composite oxide of silicon oxide and aluminum oxide is preferred from the standpoint of achieving both flexibility and denseness of the thin film layer.
  • the mixing ratio of silicon oxide and aluminum oxide is preferably such that Al is in the range of 20 to 70% by mass in terms of metal content. If the Al concentration is less than 20% by mass, the water vapor barrier property may be lowered. On the other hand, if it exceeds 70% by mass, the inorganic thin film layer tends to become hard, and there is a risk that the film will be destroyed during secondary processing such as printing or lamination, resulting in a decrease in gas barrier properties.
  • silicon oxide herein refers to various silicon oxides such as SiO and SiO 2 or mixtures thereof
  • aluminum oxide refers to various aluminum oxides such as AlO and Al 2 O 3 or mixtures thereof.
  • the thickness of the inorganic thin film layer (B) is usually 1 to 100 nm, preferably 5 to 50 nm. If the film thickness of the inorganic thin film layer (B) is less than 1 nm, it may be difficult to obtain satisfactory gas barrier properties.On the other hand, even if it is excessively thick by exceeding 100 nm, the corresponding improvement in gas barrier properties may not be achieved. No effect can be obtained, and it is rather disadvantageous in terms of bending resistance and manufacturing cost.
  • the method for forming the inorganic thin film layer (B) includes physical vapor deposition (PVD) such as vacuum evaporation, sputtering, and ion plating, or chemical vapor deposition (CVD). , any known vapor deposition method may be employed as appropriate.
  • PVD physical vapor deposition
  • CVD chemical vapor deposition
  • any known vapor deposition method may be employed as appropriate.
  • a typical method for forming the inorganic thin film layer (B) will be explained using a silicon oxide/aluminum oxide thin film as an example.
  • a mixture of SiO 2 and Al 2 O 3 or a mixture of SiO 2 and Al is preferably used as the evaporation raw material.
  • Particles are usually used as these vapor deposition raw materials, and in this case, the size of each particle is preferably such that the pressure during vapor deposition does not change, and the preferable particle size is 1 mm to 5 mm.
  • heating methods such as resistance heating, high frequency induction heating, electron beam heating, laser heating, etc. can be adopted. It is also possible to introduce oxygen, nitrogen, hydrogen, argon, carbon dioxide, water vapor, etc. as a reactive gas, or to adopt reactive vapor deposition using means such as ozone addition or ion assist.
  • the film forming conditions can also be changed arbitrarily, such as applying a bias to the object to be deposited (the laminated film to be subjected to vapor deposition), heating or cooling the object to be deposited.
  • the evaporation material, reaction gas, bias of the evaporation target, heating/cooling, etc. can be similarly changed when sputtering or CVD is employed.
  • an anchor coat layer (C) may be provided as an auxiliary layer for developing sufficient gas barrier properties and adhesive properties. Having the anchor coat layer (C) is preferable because it is possible to suppress exposure of oligomers and anti-blocking materials from the polypropylene resin. Furthermore, when laminating other layers on the anchor coat layer (C), it is also possible to increase the adhesion between the layers. In particular, in the formation of the inorganic thin film layer (B), the formation of the inorganic thin film layer (B) is promoted not only by adhesion but also by smoothing the surface, and the effect of improving gas barrier properties can be expected.
  • the anchor coat layer (C) itself, by using a material that has a certain degree of gas barrier property (gas barrier auxiliary property) for the anchor coat layer (C) itself, the gas barrier performance of the film when the aforementioned gas barrier layer is laminated is also greatly improved. This is preferable because it allows Furthermore, the anchor coat layer (C) is preferable because it prevents hot water from entering the base material, and as a result, whitening of the film after boiling or retorting can be reduced.
  • gas barrier auxiliary property gas barrier auxiliary property
  • the amount of the anchor coat layer (C) deposited is preferably 0.10 to 0.50 g/m 2 . This is preferable because the anchor coat layer (C) can be uniformly controlled during coating, resulting in a film with less coating unevenness and defects. Further, the anchor coat layer (C) is preferable because it contributes to suppressing oligomer exposure and stabilizes haze after moist heat.
  • the amount of adhesion of the anchor coat layer (C) is preferably 0.15 g/m 2 or more, more preferably 0.20 g/m 2 or more, even more preferably 0.35 g/m 2 or more, and preferably 0.50 g /m 2 or less, more preferably 0.45 g/m 2 or less, even more preferably 0.40 g/m 2 or less. If the adhesion amount of the anchor coat layer (C) exceeds 0.50 g/ m2 , the gas barrier support will improve, but the cohesive force inside the anchor coat layer will be insufficient and the uniformity of the anchor coat layer will also decrease. , causing unevenness and defects in the coat appearance. In addition, in terms of processability, a thick film may cause blocking or increase manufacturing costs.
  • the thickness of the anchor coat layer (C) is less than 0.10 g/m 2 , sufficient gas barrier support and interlayer adhesion may not be obtained.
  • the resin composition used for the anchor coat layer (C) of the present invention includes urethane-based, polyester-based, acrylic-based, titanium-based, isocyanate-based, imine-based, and polybutadiene-based resins, as well as epoxy-based, isocyanate-based, and melamine-based resins.
  • examples include those to which a hardening agent such as the following is added.
  • crosslinking agents such as silicon-based crosslinking agents, oxazoline compounds, carbodiimide compounds, and epoxy compounds can be included.
  • urethane resin in the anchor coat layer (C), in addition to the barrier performance due to the high cohesiveness of the urethane bonds themselves, the polar groups interact with the inorganic thin film layer (B), and the presence of amorphous parts Since it also has flexibility, damage can be suppressed even when a bending load is applied, which is preferable.
  • Polyester resin is also suitable since it can be expected to have similar effects.
  • it is particularly preferable to contain polyurethane containing polyester and isocyanate as constituent components, and it is more preferable to add a silicon-based crosslinking agent from the viewpoint of improving adhesiveness.
  • the urethane resin used in the anchor coat layer (C) of the present invention it is more preferable to use a urethane resin containing an aromatic or araliphatic diisocyanate component as a main component from the viewpoint of gas barrier assistance.
  • a urethane resin containing an aromatic or araliphatic diisocyanate component it is particularly preferable to contain a metaxylylene diisocyanate component.
  • the proportion of aromatic or araliphatic diisocyanate in the urethane resin used for the anchor coat layer (C) is within the range of 50 mol% or more (50 to 100 mol%) based on 100 mol% of the polyisocyanate component. It is preferable to do so.
  • the proportion of the total amount of aromatic or araliphatic diisocyanate is preferably 60 to 100 mol%, more preferably 70 to 100 mol%, even more preferably 80 to 100 mol%. If the total amount of aromatic or araliphatic diisocyanate is less than 50 mol%, good gas barrier assistance may not be obtained.
  • the urethane resin used in the anchor coat layer (C) of the present invention may contain various crosslinking agents for the purpose of improving the cohesive force and moist heat-resistant adhesiveness of the film.
  • the crosslinking agent include silicon-based crosslinking agents, oxazoline compounds, carbodiimide compounds, and epoxy compounds.
  • a silicon-based cross-linking agent is particularly preferred from the viewpoint that water-resistant adhesion to an inorganic thin film layer can be particularly improved by blending the silicon-based cross-linking agent.
  • an oxazoline compound, a carbodiimide compound, an epoxy compound, etc. may be used in combination.
  • a silane coupling agent is preferable from the viewpoint of crosslinking between an inorganic substance and an organic substance.
  • the silane coupling agent hydrolyzable alkoxysilane compounds such as halogen-containing alkoxysilanes (2-chloroethyltrimethoxysilane, 2-chloroethyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, chloroC2-4 alkyl triC1-4 alkoxysilane such as ethoxysilane), alkoxysilane having an epoxy group [2-glycidyloxyethyltrimethoxysilane, 2-glycidyloxyethyltriethoxysilane, 3-glycidyloxypropyltrimethoxy silane, glycidyloxyC2-4alkyltriC1-4alkoxysilane such as 3-glycidyl
  • alkoxysilanes having a vinyl group (vinyltriC1-4 alkoxysilanes such as vinyltrimethoxysilane and vinyltriethoxysilane), alkoxysilanes having an ethylenically unsaturated bond group [2-(meth)acryloxyethyltri (Meth)acryloxyC2-4alkyltriC1 such as methoxysilane, 2-(meth)acryloxyethyltriethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, etc.
  • vinyltriC1-4 alkoxysilanes such as vinyltrimethoxysilane and vinyltriethoxysilane
  • alkoxysilanes having an ethylenically unsaturated bond group [2-(meth)acryloxyethyltri (Meth)acryloxyC2-4alkyltriC1 such as methoxysilane, 2-(me
  • Examples include (meth)acryloxydiC2-4alkyldiC1-4alkoxysilanes such as -4 alkoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, and 3-(meth)acryloxypropylmethyldiethoxysilane. .
  • These silane coupling agents can be used alone or in combination of two or more. Among these silane coupling agents, silane coupling agents having an amino group are preferred.
  • the silicon-based crosslinking agent is preferably added in an amount of 0.05 to 4.00% by mass, more preferably 0.10 to 3.50% by mass, even more preferably 0.15 to 3% by mass. .00% by mass.
  • Addition of a silicon-based crosslinking agent is preferable because it promotes curing of the film and improves cohesive force, resulting in a film with excellent water-resistant adhesion, and can also be expected to have the effect of preventing the exposure of oligomers. If the amount added exceeds 4.00% by mass, the film will be cured and the cohesive force will be improved, but some unreacted portions may also be produced and the adhesion between the layers may be reduced. On the other hand, if the amount added is less than 0.05% by mass, sufficient cohesive force may not be obtained.
  • the polyester resin used for the anchor coat layer (C) of the present invention is produced by polycondensing a polyhydric carboxylic acid component and a polyhydric alcohol component.
  • the molecular weight of the polyester resin is not particularly limited as long as it can provide sufficient film toughness, coating suitability, and solvent solubility as a coating material, but the number average molecular weight is 1,000 to 50,000, more preferably 1,500 to 30,000. be.
  • an isocyanate curing agent is used in combination, it is necessary to use a polyester polyol mainly containing alcohol terminals.
  • the Tg of the polyester resin used for the anchor coat layer (C) of the present invention is 10° C. or higher. This is because if the temperature is lower than this, the resin becomes sticky after the coating operation and tends to cause blocking, making it difficult to wind up the resin after coating. This is because if the Tg becomes 10° C. or lower, it becomes difficult to prevent blocking even when the pressure near the winding core is high even by adding an anti-blocking material.
  • a more preferable temperature of Tg is 15°C or higher, more preferably 20°C or higher.
  • the polyester resin used in the anchor coat layer (C) of the present invention is used by polycondensing a polyhydric carboxylic acid component and a polyhydric alcohol component.
  • the polyhydric carboxylic acid component of the polyester resin used in the present invention is characterized in that it contains at least one ortho-oriented aromatic dicarboxylic acid or anhydride thereof.
  • the ortho-orientation improves solubility in solvents and enables uniform coating on the substrate.
  • a uniformly coated film reduces variations in barrier performance, which ultimately contributes to suppressing oligo whitening.
  • the ortho-orientation creates a film with excellent flexibility and improves interfacial adhesion, which reduces damage to the base material due to moist heat treatment and leads to suppression of oligomer formation.
  • aromatic polycarboxylic acid or its anhydride in which carboxylic acid is substituted at the ortho position examples include orthophthalic acid or its anhydride, naphthalene 2,3-dicarboxylic acid or its anhydride, and naphthalene 1,2-dicarboxylic acid or its anhydride.
  • aromatic polycarboxylic acid or its anhydride examples include orthophthalic acid or its anhydride, naphthalene 2,3-dicarboxylic acid or its anhydride, and naphthalene 1,2-dicarboxylic acid or its anhydride.
  • Examples include anhydride, anthraquinone 2,3-dicarboxylic acid or its anhydride, and 2,3-anthracenecarboxylic acid or its anhydride. These compounds may have a substituent on any carbon atom of the aromatic ring.
  • Examples of the substituent include a chloro group, a bromo group, a methyl group, an ethyl group, an i-propyl group, a hydroxyl group, a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, a phenylthio group, a cyano group, a nitro group, an amino group, Examples include phthalimide group, carboxyl group, carbamoyl group, N-ethylcarbamoyl group, phenyl group, and naphthyl group.
  • polyester polyols with a content of 70 to 100 mol% based on 100 mol% of the total polycarboxylic acid components not only have a high barrier property improvement effect but also have excellent solvent solubility, which is essential as a coating material. Particularly preferred.
  • aliphatic polycarboxylic acids include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, etc.
  • unsaturated bond-containing polycarboxylic acids include maleic anhydride, maleic acid, Fumaric acid, etc.
  • alicyclic polycarboxylic acids such as 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, etc.
  • aromatic polycarboxylic acids such as terephthalic acid, isophthalic acid, pyro- Mellitic acid, trimellitic acid, 1,4-naphthalene dicarboxylic acid, 2,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, naphthalic acid, biphen
  • succinic acid 1,3-cyclopentanedicarboxylic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,8-naphthalic acid, and diphenic acid are preferred from the viewpoint of organic solvent solubility and gas barrier properties.
  • the polyhydric alcohol component of the polyester used in the anchor coat layer (C) of the present invention is not particularly limited as long as it can synthesize a polyester that exhibits gas barrier compensation performance, but examples include ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, and cyclohexane. It is preferable to contain a polyhydric alcohol component containing at least one selected from the group consisting of dimethanol and 1,3-bishydroxyethylbenzene. Among these, it is most preferable to use ethylene glycol as the main component because it is presumed that the smaller the number of carbon atoms between oxygen atoms, the less the molecular chain becomes excessively flexible and the more difficult oxygen permeation occurs.
  • the polyhydric alcohol component described above it is preferable to use the polyhydric alcohol component described above, but other polyhydric alcohol components may be copolymerized as long as the effects of the present invention are not impaired.
  • the diols include 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol, dimethylbutanediol, butylethylpropanediol, diethylene glycol, and triethylene glycol.
  • Ethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, trihydric or higher alcohols include glycerol, trimethylolpropane, trimethylolethane, tris(2-hydroxyethyl)isocyanurate, 1,2,4- Examples include butanetriol, pentaerythritol, dipentaerythritol, and the like.
  • polyesters containing glycerol and tris(2-hydroxyethyl) isocyanurate have a moderately high crosslinking density due to their branched structure, and have good solubility in organic solvents. It also has an excellent barrier function and is particularly preferably used.
  • Catalysts used in the reaction to obtain the polyester of the present invention include tin-based catalysts such as monobutyl tin oxide and dibutyl tin oxide, titanium-based catalysts such as tetra-isopropyl-titanate and tetra-butyl-titanate, and tetra-butyl-zirconate.
  • tin-based catalysts such as monobutyl tin oxide and dibutyl tin oxide
  • titanium-based catalysts such as tetra-isopropyl-titanate and tetra-butyl-titanate
  • tetra-butyl-zirconate examples include acid catalysts such as zirconia catalysts. It is preferable to use a combination of the titanium-based catalyst, such as tetra-isopropyl-titanate or tetra-butyl-titanate, which has high activity for ester reactions, and the zir
  • the amount of the catalyst used is 1 to 1000 ppm, more preferably 10 to 100 ppm, based on the total mass of the reaction materials used. If it is less than 1 ppm, it is difficult to obtain the effect as a catalyst, and if it exceeds 1000 ppm, there may be a problem of inhibiting the urethanization reaction when using an isocyanate curing agent.
  • the coating agent constituting the anchor coat layer (C) when a polyester resin is used as the main ingredient of the coating agent constituting the anchor coat layer (C), it is particularly preferable to use an isocyanate-based curing agent to form a urethane resin.
  • an isocyanate-based curing agent since the coating layer is crosslinked, there is an advantage that heat resistance, abrasion resistance, and rigidity are improved. Therefore, it is easy to use for boiling and retort packaging.
  • the coating solution can be diluted and reused, and there is no need for a curing process (so-called aging process).
  • aging process An example can be given of this point.
  • the terminal end of the polyester used may be a polyol, a polycarboxylic acid, or a mixture of the two without any problem.
  • the resin of the anchor coat layer (C) since the resin of the anchor coat layer (C) is linear, it may not have sufficient heat resistance or abrasion resistance, or it may be difficult to use for boiling or retort packaging.
  • an isocyanate curing system is preferable from the viewpoint of the heat resistance of the film since the coating is on a film, and in this case, the resin component of the coating material needs to be a polyester polyol. be.
  • the resin component of the coating material needs to be a polyester polyol. be.
  • an epoxy compound when used as a curing agent, it needs to be a polyester polycarboxylic acid.
  • the coating layer is crosslinked, which has the advantage of improved heat resistance, abrasion resistance, and rigidity. Therefore, it is easy to use for boiling and retort packaging.
  • the polyester has a hydroxyl group
  • at least a portion of the polyisocyanate compound used in the present invention reacts to form a urethane structure, making it highly polar as a resin component, and further strengthening the gas barrier function by coagulating between polymer chains. can.
  • the resin of the coating material is a linear resin
  • heat resistance and abrasion resistance can be imparted by crosslinking with a trivalent or higher valent polyisocyanate.
  • the polyisocyanate compound used in the present invention may be a diisocyanate, a trivalent or higher polyisocyanate, a low-molecular compound, or a high-molecular compound, but if it contains an aromatic ring or an aliphatic ring in a part of the skeleton, the gas barrier Preferable from the viewpoint of improved functionality.
  • isocyanates with an aromatic ring include toluene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, and naphthalene diisocyanate, and isocyanates with an aliphatic ring include hydrogenated xylylene diisocyanate, hydrogenated toluene diisocyanate, isophorone diisocyanate, and norbornene diisocyanate.
  • trimers of these isocyanate compounds such as ethylene glycol, propylene glycol, trimethylolpropane, glycerin, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine, etc.
  • examples include terminal isocyanate group-containing compounds obtained by reacting with low-molecular active hydrogen compounds or high-molecular active hydrogen compounds such as various polyester polyols, polyether polyols, and polyamides.
  • the method for forming the anchor coat layer (C) is not particularly limited, and for example, a conventionally known method such as a coating method can be employed.
  • a coating method such as a coating method can be employed.
  • preferable methods include an offline coating method and an inline coating method.
  • the drying and heat treatment conditions during coating will depend on the coating thickness and equipment conditions, but immediately after coating, the film is sent to the orthogonal stretching process. It is preferable to dry the film in the preheating zone or stretching zone of the stretching process, and in such a case, the temperature is usually about 50 to 250°C.
  • the coating method of the resin composition for the anchor coat layer (C) is not particularly limited as long as it is a method of coating the film surface to form a layer.
  • conventional coating methods such as gravure coating, reverse roll coating, wire bar coating, and die coating can be employed.
  • the drying temperature at that time is preferably 100 to 145 ° C., more preferably is 110 to 140°C, more preferably 110 to 130°C. If the drying temperature is less than 100°C, the anchor coat layer may be insufficiently dried. On the other hand, if the drying temperature exceeds 145° C., too much heat is applied to the film, which may cause the film to become brittle or shrink, resulting in poor workability. In particular, it is particularly preferable to first volatilize the solvent immediately after coating at a relatively low temperature condition of 80° C. to 110° C., and then dry it at 120° C. or higher, since a uniform film can be obtained. Further, in addition to drying, it is also more effective to perform additional heat treatment in a low temperature range as much as possible in promoting film formation of the anchor coat layer.
  • a protective layer (D) on gas barrier layer In the present invention, a protective layer (D) may be provided on the gas barrier layer.
  • the gas barrier layer is an inorganic thin film layer (B)
  • the inorganic thin film layer (B) made of a metal oxide layer is not a completely dense film, but is dotted with minute defects.
  • the resin for the protective layer (D) is applied to the defective part of the metal oxide layer.
  • the resin in the composition permeates, resulting in the effect that the barrier properties of the gas barrier layer are stabilized.
  • the gas barrier performance of the laminated film is also improved.
  • the amount of the protective layer (D) deposited is preferably 0.10 to 0.40 (g/m 2 ). This is preferable because the protective layer (D) can be uniformly controlled during coating, resulting in a film with less coating unevenness and defects. It is also preferable because the cohesive force of the protective layer (D) itself is improved and the adhesion between the gas barrier layer (especially the inorganic thin film layer (B)) and the protective layer (D) is also strengthened.
  • the amount of adhesion of the protective layer is preferably 0.13 (g/m 2 ) or more, more preferably 0.16 (g/m 2 ) or more, even more preferably 0.19 (g/m 2 ) or more, It is preferably 0.37 (g/m 2 ) or less, more preferably 0.34 (g/m 2 ) or less, even more preferably 0.31 (g/m 2 ) or less. If the amount of the protective layer (D) attached exceeds 0.40 (g/m 2 ), the gas barrier properties will improve, but the cohesive force inside the protective layer will be insufficient and the uniformity of the protective layer will also decrease. , unevenness or defects may occur in the coat appearance, and gas barrier properties and adhesion properties may not be sufficiently developed. On the other hand, if the amount of the protective layer (D) deposited is less than 0.10 (g/m 2 ), sufficient gas barrier properties and interlayer adhesion may not be obtained.
  • the resin composition used for the protective layer (D) formed on the surface of the gas barrier layer (especially the inorganic thin film layer (B)) of the present invention includes polyvinyl alcohol-based, urethane-based, polyester-based, acrylic-based, titanium-based, and isocyanate-based resin compositions. , imine-based, polybutadiene-based resins, etc. may be used, and furthermore, epoxy-based, isocyanate-based, melamine-based, silanol-based, and other curing agents may be added.
  • the coating method of the resin composition for the protective layer (D) is not particularly limited as long as it is a method of coating the film surface to form a layer.
  • conventional coating methods such as gravure coating, reverse roll coating, wire bar coating, and die coating can be employed.
  • the protective layer (D) When forming the protective layer (D), it is preferable to apply the resin composition for the protective layer (D) and then heat dry it, and the drying temperature at that time is preferably 100 to 160°C, more preferably 110°C. ⁇ 150°C, more preferably 120 ⁇ 140°C. If the drying temperature is less than 100°C, the protective layer (D) may be insufficiently dried, or the film formation of the protective layer (D) may not proceed, resulting in a decrease in cohesive force and water-resistant adhesion, resulting in poor barrier properties and poor handling. There is a risk that cutting performance will decrease.
  • drying temperature exceeds 160° C.
  • too much heat is applied to the film, which may cause the film to become brittle, resulting in a decrease in puncture strength, or shrinkage, resulting in poor workability.
  • it is also more effective to perform additional heat treatment at a low temperature as much as possible in order to advance the formation of the protective layer.
  • films In the present invention, other films than the base film containing a polyolefin resin as a constituent may be included within a range that satisfies the below-mentioned monomaterial ratio to the packaging material.
  • Other films used in the present invention are, for example, films made by melt-extruding plastic and stretching, cooling, and heat setting in the longitudinal direction and/or width direction as necessary. Examples of the plastic include nylon 4. 6.
  • polyesters represented by nylon 6, nylon 6/6, and nylon 12 polyesters represented by polyethylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, etc., polyvinyl chloride, polyvinylidene chloride, Examples include polyvinyl alcohol, ethylene vinyl alcohol, wholly aromatic polyamide, polyamideimide, polyimide, polyetherimide, polysulfone, polystyrene, and polylactic acid.
  • films in the present invention can have any thickness depending on desired objectives such as mechanical strength and transparency. Although not particularly limited, it is usually recommended that the thickness be 5 to 250 ⁇ m, and preferably 10 to 60 ⁇ m when used as a packaging material. However, it is necessary to consider the monomaterial ratio of packaging materials, which will be described later.
  • the other film in the present invention may be a laminated film of one or more types of plastic films.
  • the type of laminate, the number of layers, the method of lamination, etc. are not particularly limited, and can be arbitrarily selected from known methods depending on the purpose.
  • the heat-sealable resin film used in the present invention contains a propylene- ⁇ olefin random copolymer as a polyolefin resin composition, and is further made from an ethylene-propylene copolymer elastomer, an ethylene-butene copolymer elastomer, or a propylene-butene copolymer elastomer. Preferably, it contains at least one selected component.
  • the propylene- ⁇ -olefin random copolymer includes a copolymer of propylene and at least one ⁇ -olefin having 2 or 4 to 20 carbon atoms other than propylene.
  • ⁇ -olefin monomers having 2 or 4 to 20 carbon atoms ethylene, 1-butene, 1-pentene, 4-methylpentene-1, hexene-1, octene-1, etc. can be used.
  • ethylene is preferably used from the viewpoint of stretchability and low shrinkage. Further, it is sufficient that at least one kind is used, and two or more kinds can be mixed and used as necessary.
  • Particularly suitable is a propylene-ethylene random copolymer.
  • the lower limit of the melt flow rate (MFR) of the propylene- ⁇ olefin random copolymer is preferably 0.6 g/10 min, more preferably 1.0 g/10 min, and even more preferably 1.2 g/10 min. be.
  • the upper limit of the melt flow rate of the random copolymer is preferably 12.0 g/10 min, more preferably 9.0 g/10 min, and still more preferably 8.0 g/10 min. If the melt flow rate is outside this range, the uniformity of the film thickness may be impaired.
  • copolymers falling within this range include propylene-ethylene random copolymer (manufactured by Sumitomo Chemical Co., Ltd., Sumitomo Noblen WF577PG, MFR 3.2 g/10 min at 230°C, load 2.16 kg, melting point 142°C), propylene-ethylene-butene random copolymer (manufactured by Sumitomo Chemical Co., Ltd., Suminoblen FL8115A, MFR 7.0g/10min at 230°C, load 2.16kg, melting point 148°C), propylene-ethylene-butene random copolymer Copolymers (manufactured by Sumitomo Chemical Co., Ltd., Sumitomo Noblen FL6745A, MFR 6.0 g/10 min at 230° C., load 2.16 kg, melting point 130° C.) can be mentioned.
  • Particularly suitable is a propylene-ethylene random copolymer in which the main monomer is propylene and a certain amount of ethylene is copolymerized.
  • the random copolymers are named and described in descending order of monomer composition ratio.
  • the lower limit of the melting point of the propylene- ⁇ olefin random copolymer is not particularly limited, but is preferably 120°C, more preferably 125°C. If it is less than the above, heat resistance will be impaired and the inner surfaces of the bag may fuse together during moist heat treatment.
  • the upper limit of the melting point of the propylene- ⁇ -olefin random copolymer is not particularly limited, but is preferably 155°C, more preferably 150°C. If the temperature exceeds the above, the temperature required for heat sealing may become high.
  • thermoplastic copolymer elastomer mainly composed of polyolefin
  • the copolymerized elastomer in the present invention is at least an olefinic thermoplastic copolymerized elastomer that exhibits rubber-like elasticity at around room temperature, and an olefinic thermoplastic copolymerized elastomer that exhibits relatively high Shore hardness and good transparency among elastomers. It is preferable to use two or more types of copolymerized elastomers together. By using these in combination, transparency, sealability, and bag breakage resistance can be easily obtained even if tearability, tearability, and bag-making properties are imparted, which is preferable.
  • olefin-based thermoplastic copolymer elastomer that exhibits rubber-like elasticity at around room temperature
  • an ethylene-butene copolymer elastomer which is an amorphous or low-crystalline elastomer obtained by copolymerizing ethylene and butene.
  • a propylene-butene copolymer elastomer which is a crystalline elastomer obtained by copolymerizing ethylene and butene, is an olefin-based thermoplastic copolymer elastomer that exhibits relatively high Shore hardness and good transparency.
  • melt flow rate (MFR) of ethylene-butene copolymer elastomer and ethylene-propylene copolymer elastomer at 230 °C and a load of 2.16 kg is 0.2 to 5.0 g/10 min (or at 190 °C and a load of 2.16 kg).
  • Melt flow rate (MFR) is 0.2 to 5.0 g/10 min)
  • density is 820 to 930 kg/m 3
  • Mw/Mn molecular weight distribution
  • melt flow rate (MFR) at a load of 2.16 kg is less than 0.2 g/10 min, uniform kneading becomes insufficient and fish eyes are likely to occur, and when it exceeds 5.0 g/min, tear-resistant bags Undesirable from a sexual perspective.
  • the intrinsic viscosity [ ⁇ ] of the ethylene-butene copolymer elastomer and propylene-butene copolymer elastomer in the present invention is determined from the viewpoints of heat seal strength retention, impact strength retention, and drop bag strength. It is preferably 1.0 to 5.0, preferably 1.2 to 3.0. When the intrinsic viscosity [ ⁇ ] is less than 1.0, uniform kneading becomes insufficient and fish eyes are likely to occur, and when it exceeds 5.0, it is unfavorable from the viewpoint of bag tear resistance and heat seal strength. .
  • an ethylene-butene copolymer elastomer manufactured by Mitsui Chemicals, Inc., Tafmer A1085S
  • a density of 885 kg/m 3 and an MFR (230° C., 2.16 kg) of 1.4 g/10 min; .16kg) 3.6g/10min ethylene-butene copolymer elastomer manufactured by Mitsui Chemicals, Inc., Tafmer A-4070S
  • density 900kg/m 3 MFR (190°C, 2.16kg) 3g/10min propylene.
  • An example is a butene copolymer elastomer (manufactured by Mitsui Chemicals, Inc., Tafmer XM7070).
  • the polyolefin resin composition of the heat-sealable resin film of the present invention 2 to 9 parts by mass of the ethylene-butene copolymer elastomer and the propylene-butene copolymer elastomer are added to 100 parts by mass of the propylene- ⁇ olefin random copolymer. It is preferable to contain 2 to 9 parts by mass.
  • the polyolefin resin composition 4 to 9 parts by mass of an ethylene-butene copolymer elastomer and 4 to 9 parts by mass of a propylene-butene copolymer elastomer are contained per 100 parts by mass of the propylene- ⁇ olefin random copolymer. It is more preferable. Furthermore, the polyolefin resin composition contains 5 to 9 parts by mass of an ethylene-butene copolymer elastomer and 5 to 9 parts by mass of a propylene-butene copolymer elastomer per 100 parts by mass of the propylene- ⁇ olefin random copolymer. It is more preferable to do so.
  • the polyolefin resin composition contains 6 to 9 parts by mass of an ethylene-butene copolymer elastomer and 6 to 9 parts by mass of a propylene-butene copolymer elastomer per 100 parts by mass of the propylene- ⁇ olefin random copolymer. It is more preferable to do so.
  • the polyolefin resin composition in the heat-sealable resin film of the present invention may contain an anti-blocking agent.
  • an anti-blocking agent may be used, but it is better to combine two or more types of inorganic particles with different particle sizes and shapes to form complex protrusions even on the unevenness of the film surface and obtain a more advanced anti-blocking effect. be able to.
  • the anti-blocking agent to be added is not particularly limited, but includes inorganic particles such as spherical silica, amorphous silica, zeolite, talc, mica, alumina, hydrotalcite, and aluminum borate, polymethyl methacrylate, and ultra-high molecular weight.
  • Organic particles such as polyethylene can be added.
  • the above additives may be added to all layers, and if the surface of the layer on which the biaxially oriented film is laminated has unevenness, Since this may result in poor appearance during lamination, it is preferable to add it only to the layer on the side where the films are heat-sealed.
  • the layer on the side where biaxially oriented films are laminated is called the laminate layer, and its surface is called the laminate surface
  • the layer on the side where one film is heat-sealed is called the heat-seal layer, and its surface is called the heat-seal surface.
  • the amount of the anti-blocking agent added is preferably 3000 ppm or less, more preferably 2500 ppm or less, based on the polyolefin resin composition of the layer to which it is added. By setting the amount to 3000 ppm or less, it is possible to reduce shedding of the anti-blocking agent.
  • An organic lubricant may be added to the polyolefin resin composition in the heat-sealable resin film of the present invention.
  • the lubricity and anti-blocking effect of the laminated film are improved, making the film easier to handle. The reason for this is thought to be that the organic lubricant bleeds out and is present on the film surface, resulting in a lubricant effect and mold release effect.
  • organic lubricant that has a melting point above room temperature.
  • organic lubricants include fatty acid amides and fatty acid esters. Specifically, they include oleic acid amide, erucic acid amide, behenic acid amide, ethylene bis oleic acid amide, hexamethylene bis oleic acid amide, ethylene bis oleic acid amide, and the like. Although these may be used alone, it is preferable to use two or more of them in combination, since the lubricity and anti-blocking effect can be maintained even under harsh environments.
  • the polyolefin resin composition in the heat-sealable resin film of the present invention may contain an appropriate amount of an antioxidant, an antistatic agent, an antifogging agent, and a neutralizing agent in any layer as necessary within a range that does not impair the purpose of the present invention.
  • a nucleating agent, a coloring agent, other additives, an inorganic filler, etc. can be blended.
  • antioxidant phenol type and phosphite type antioxidants may be used in combination, or one having a phenol type and phosphite type skeleton in one molecule may be used alone.
  • neutralizing agents include calcium stearate.
  • the heat-sealable resin film of the present invention may be a single layer film or a multilayer film having two or more layers.
  • the heat-sealable resin film of the present invention may be a single layer film or a multilayer film having two or more layers.
  • a propylene- ⁇ -olefin random copolymer with a low melting point is added only to the sealing layer, while a propylene- ⁇ -olefin random copolymer with a high melting point is mainly used in the intermediate layer and laminate layer.
  • Each layer uses resin with a slightly different composition. By using it, the effect can be further enhanced.
  • an inflation method or a T-die method can be used, but the T-die method is preferable in order to improve transparency and ease of drafting.
  • the inflation method uses air as the cooling medium, whereas the T-die method uses cooling rolls, so it is an advantageous manufacturing method for increasing the cooling rate. By increasing the cooling rate, crystallization of the unstretched sheet can be suppressed, so stretching with rolls is advantageous in the subsequent process. For these reasons, it is preferable to use a sheet with no orientation in the T-die direction.
  • the lower limit of the temperature of the cooling roll when casting the molten raw resin to obtain a non-oriented sheet is preferably 15°C, more preferably 20°C. If it is less than the above, dew condensation may occur on the cooling roll, resulting in insufficient adhesion.
  • the upper limit of the cooling roll is preferably 60°C, more preferably 50°C. If it exceeds the above, transparency may deteriorate.
  • the method for stretching an unoriented sheet is not particularly limited, and for example, an inflation method, a tenter horizontal stretching method, and a roll longitudinal stretching method can be used, but the roll longitudinal stretching method is preferable because of the ease of controlling the orientation.
  • Longitudinal stretching here means the direction in which the film flows from the time of casting the raw resin composition to the step of winding up the stretched film, and the transverse direction means the direction perpendicular to the flow direction.
  • Stretching a non-oriented sheet is preferable because straight cutting properties are achieved. This is because the molecular chain structure is regularly arranged in the stretching direction.
  • the lower limit of the stretching ratio is preferably 3.3 times. If it is smaller than this, the yield strength may decrease, the tear strength may increase, and the straight cutting performance may be poor. More preferably it is 3.5 times, and still more preferably 3.8 times.
  • the upper limit of the stretching ratio is preferably 5.5 times. If it is larger than this, the orientation progresses excessively, the sealing energy decreases, and the bag breakage resistance after dropping may deteriorate. More preferably it is 5.0 times, and still more preferably 4.7 times.
  • the lower limit of the stretching roll temperature is not particularly limited, but is preferably 80°C. If it is lower than this, the stretching stress applied to the film becomes high, which may cause the film to fluctuate in thickness. More preferably it is 90°C.
  • the upper limit of the stretching roll temperature is not particularly limited, but is preferably 140°C. If it exceeds this range, the stretching stress applied to the film becomes low, which not only reduces the tear strength of the film, but also causes the film to fuse to the stretching rolls, making production difficult.
  • the temperature is more preferably 130°C, further preferably 125°C, particularly preferably 115°C.
  • the lower limit of the preheating roll temperature when stretching a non-oriented sheet is not particularly limited, but is preferably 80°C, more preferably 90°C. When it is less than the above, the stretching stress becomes high and thickness fluctuation may occur.
  • the upper limit of the preheat roll temperature is not particularly limited, but is preferably 140°C, more preferably 130°C, and even more preferably 125°C. If it is more than the above, the heat shrinkage rate and retort shrinkage rate may increase. This is because thermal crystallization before stretching can be suppressed and residual stress after stretching can be reduced.
  • the film that has undergone the longitudinal stretching process is preferably subjected to an annealing treatment in order to suppress thermal shrinkage.
  • Annealing methods include a roll heating method, a tenter method, and the like, but the roll heating method is preferable because of the simplicity of the equipment and ease of maintenance.
  • Annealing can reduce the internal stress of the film and thereby suppress the thermal shrinkage of the film, but it may adversely affect properties other than the thermal shrinkage rate.
  • an ethylene-butene copolymer elastomer and a propylene-butene copolymer elastomer in combination this adverse effect can be suppressed.
  • the lower limit of the annealing temperature is not particularly limited, but is preferably 80°C. If it is less than the above, the thermal shrinkage rate may become high, the tear strength may become high, and the finish of the packaging bag after bag making or retorting may deteriorate.
  • the temperature is more preferably 100°C, and particularly preferably 110°C.
  • the upper limit of the annealing temperature is preferably 140°C. The higher the annealing temperature, the more likely the thermal shrinkage rate will decrease, but if the annealing temperature is 140°C or lower, it will be difficult to cause uneven film thickness, and the film will not be fused to the manufacturing equipment, and the transparency, sealability, and tear resistance of the bag will be reduced. Decreased sexiness and difficulty in swallowing.
  • the temperature is more preferably 135°C, particularly preferably 130°C.
  • a relaxation step can be provided by sequentially slowing down the transport speed of the film, such as by decreasing the rotational speed of the roll.
  • the upper limit of the relaxation rate in the relaxation step is preferably 10%, more preferably 8%. If it is 10% or less, the film is less likely to sag during transportation and is less likely to be wrapped around the process, which is preferable.
  • the lower limit of the relaxation rate is preferably 1%, more preferably 3%. When it is 1% or more, the heat shrinkage rate of the heat-sealable resin film is less likely to increase, which is preferable.
  • the lower limit of the thickness of the heat-sealable resin film of the present invention is preferably 20 ⁇ m, more preferably 30 ⁇ m, still more preferably 40 ⁇ m, particularly preferably 50 ⁇ m. If it is 20 ⁇ m or more, it will be thicker relative to the thickness of the base film, so the straight cutability of the laminate will not deteriorate easily, and the film will have a stiff feel and be easier to process, as well as impact resistance. This is preferable because it is easy to obtain bag breakage resistance.
  • the upper limit of the film thickness is preferably 150 ⁇ m, more preferably 100 ⁇ m, and still more preferably 80 ⁇ m. A thickness of 150 ⁇ m or less is preferable because the film does not have too much stiffness and is easy to process, and it is also easy to manufacture a suitable package.
  • the upper limit of the heat shrinkage rate at 120°C in the longitudinal direction and width direction of the heat-sealable resin film used in the present invention is preferably 35%, more preferably 25%. . If it is 35% or less, shrinkage during heat sealing or moist heat treatment of the package will be small, and the appearance of the package will not be easily damaged, which is preferable. More preferably it is 20%, still more preferably 17%.
  • the lower limit of the heat shrinkage rate in the longitudinal direction and width direction of the heat-sealable resin film of the present invention in the direction where the heat shrinkage rate is large is preferably 2%.
  • the upper limit of the heat shrinkage rate in the longitudinal direction and the width direction of the heat-sealable resin film used in the present invention in the direction where the heat shrinkage rate is smaller is preferably 1%. If it exceeds 1%, the tear strength in the direction of high heat shrinkage will increase or the straight cutting performance will be poor. Preferably it is 0.5%.
  • the lower limit of the heat shrinkage rate in the longitudinal direction and width direction of the heat-sealable resin film used in the present invention in the direction where the heat shrinkage rate is smaller is -5%. If it is -5% or more, the film is less likely to stretch during the heat sealing process and the appearance of the package is less likely to deteriorate, which is preferable. More preferably -3%.
  • the longitudinal orientation coefficient ⁇ Nx used in the present invention can be calculated using Equation 1.
  • ⁇ Nx Nx-(Ny+Nz)/2 (Formula 1)
  • Ny refractive index in the direction perpendicular to the longitudinal direction
  • Nz refractive index in the planar direction
  • the lower limit of the orientation coefficient ⁇ Nx in the longitudinal direction of the heat-sealable resin film of the present invention is preferably 0. 010, more preferably 0.015, still more preferably 0.020. If it is 0.010 or more, it is preferable because the package can be easily cut in a straight line.
  • the upper limit of the longitudinal orientation coefficient ⁇ Nx is preferably 0.0270, more preferably 0.026. If it is 0.0270 or less, the seal strength is less likely to decrease, which is preferable.
  • the plane orientation coefficient ⁇ P used in the present invention can be calculated from the refractive index.
  • the orientation coefficient in the plane direction can be calculated using Equation 2.
  • ⁇ P (Nx+Ny)/2-Nz (Formula 2)
  • Ny refractive index in the direction perpendicular to the longitudinal direction
  • Nz refractive index in the planar direction
  • the lower limit of the orientation coefficient ⁇ P in the planar direction of the heat-sealable resin film of the present invention is preferably 0. 0050, more preferably 0.0100. A value of 0.0050 or more is preferable because the puncture strength of the package can be easily obtained.
  • the film is oriented because the rigidity necessary to ensure a firm feel can be obtained. Loop stiffness evaluation as an index of back feeling will be described later.
  • the upper limit of the plane orientation coefficient ⁇ P is preferably 0.0145, more preferably 0.0140, and still more preferably 0.0130. If it is 0.0145 or less, the seal strength is less likely to decrease, which is preferable.
  • the base film and the heat-sealable resin film can be laminated by a dry lamination method using an adhesive.
  • a general-purpose laminating adhesive can be used. For example, poly(ester) urethane type, polyester type, polyamide type, epoxy type, poly(meth)acrylic type, polyethyleneimine type, ethylene-(meth)acrylic acid type, polyvinyl acetate type, (modified) polyolefin type, polybutadiene type.
  • Solvent-based, water-based, or hot-melt type adhesives whose main component is a wax-based adhesive, a wax-based adhesive, a casein-based adhesive, or the like can be used.
  • urethane-based or polyester-based materials are preferred in consideration of heat resistance and flexibility that can follow dimensional changes of each base material.
  • laminating methods for the adhesive layer include direct gravure coating, reverse gravure coating, kiss coating, die coating, roll coating, dip coating, knife coating, spray coating, fontaine coating, and others.
  • the coating amount after drying is preferably 1 to 8 g/m 2 in order to develop sufficient adhesion. More preferably 2 to 7 g/m 2 , still more preferably 3 to 6 g/m 2 .
  • the coating amount is less than 1 g/m 2 , it becomes difficult to bond the entire surface, and the adhesive strength decreases. On the other hand, if it exceeds 8 g/m 2 or more, it takes time for the film to completely cure, unreacted substances tend to remain, and the adhesive strength decreases.
  • At least one printed layer may be laminated between the base film and the heat-sealable resin film or on the outside thereof.
  • aqueous and solvent-based resin-containing printing inks can be preferably used.
  • resins used in the printing ink include acrylic resins, urethane resins, polyester resins, vinyl chloride resins, vinyl acetate copolymer resins, and mixtures thereof.
  • the printing ink contains known antistatic agents, light blocking agents, ultraviolet absorbers, plasticizers, lubricants, fillers, colorants, stabilizers, lubricants, antifoaming agents, crosslinking agents, anti-blocking agents, antioxidants, etc. may also contain additives.
  • the printing method for providing the printed layer is not particularly limited, and known printing methods such as offset printing, gravure printing, and screen printing can be used.
  • known drying methods such as hot air drying, hot roll drying, and infrared drying can be used.
  • the packaging material of the present invention can have any conceivable laminated structure. From the viewpoint of environmental impact, a structure in which one base film having a barrier layer and a heat-sealable resin film are bonded together is preferable because it requires the least number of materials and bonding steps. On the other hand, as mentioned above, from the perspective of improving toughness and gas barrier performance, for example, a film with a laminated gas barrier layer can be replaced with a thermoplastic copolymer film with a base film without a gas barrier layer and a heat-sealable resin layer. A laminate that is laminated in such a way that they are sandwiched together can also be cited as one of the preferred configurations.
  • At least one of the base films peeled from the material has a heat elongation rate of 6% or less in both the MD direction and the TD direction at 130°C as measured by a thermomechanical analyzer. is necessary.
  • the heat resistance required when used as a package can be ensured.
  • the finish is good and the sealing strength is stable, and packaging has a good finish with less dimensional and appearance changes when subjected to harsh moist heat treatment such as retorting. It can be a body.
  • the heat elongation rate in the MD direction and the TD direction at 130°C is preferably 5.5% or less, more preferably 5.0% or less, even more preferably 4.5% or less, and the lower limit is preferably 0%. . If the heating elongation rate at 130° C. is outside the above range, the heat resistance as a package may be reduced, resulting in poor appearance during sealing or moist heat treatment.
  • the heating elongation rate is a value measured by a thermomechanical analyzer (TMA) method, and more specifically by the method described in Examples.
  • TMA thermomechanical analyzer
  • the heat elongation rate at 130°C must be in the MD direction.
  • the heating elongation rate can be reduced by subjecting the base film to post-heat treatment.
  • Heat treatment means include annealing the base film in a drying oven, the above-mentioned gas barrier layer formation process such as the inorganic thin film layer (B), and the anchor coat layer (C)/protective layer (D) coating process.
  • the surface temperature of the film be 65° C. or higher during heating, more preferably 70° C. or higher, and still more preferably 75° C. or higher.
  • the upper limit of heat addition is 90°C.
  • the packaging material of the present invention can exhibit good gas barrier properties when the oxygen permeability under conditions of 23° C. and 65% RH is 60 ml/m 2 ⁇ d ⁇ MPa or less. Furthermore, by providing a barrier layer on each film, it is possible to reduce the pressure to preferably 50 ml/m 2 ⁇ d ⁇ MPa or less, more preferably 40 ml/m 2 ⁇ d ⁇ MPa or less. When the oxygen permeability exceeds 60 ml/m 2 ⁇ d ⁇ MPa, it becomes difficult to support applications requiring high gas barrier properties. On the other hand, a preferable lower limit of the oxygen permeability is 0.5 ml/m 2 ⁇ d ⁇ MPa or more.
  • the barrier performance will be excellent, but it will be difficult for the residual solvent to permeate to the outside of the bag, and the amount transferred to the contents will increase relatively. This is not preferable because there is a risk.
  • the packaging material of the present invention should have an oxygen permeability of 60 ml/m 2 ⁇ d ⁇ MPa or less under 23°C x 65% RH after boiling at 95°C for 30 minutes or retorting at 120°C for 30 minutes. is preferable in that it exhibits good gas barrier properties. Furthermore, by providing a barrier layer on each film, it is possible to reduce the pressure to preferably 50 ml/m 2 ⁇ d ⁇ MPa or less, more preferably 40 ml/m 2 ⁇ d ⁇ MPa or less. When the oxygen permeability exceeds 60 ml/m 2 ⁇ d ⁇ MPa, it becomes difficult to support applications requiring high gas barrier properties.
  • a preferable lower limit of the oxygen permeability is 0.5 ml/m 2 ⁇ d ⁇ MPa or more. If the oxygen permeability is less than 0.5 ml/ m2 ⁇ d ⁇ MPa, the barrier performance will be excellent, but it will be difficult for the residual solvent to permeate to the outside of the bag, and the amount transferred to the contents will increase relatively. This is not preferable because there is a risk.
  • the packaging material of the present invention preferably has a water vapor permeability of 5.0 g/m 2 ⁇ d or less under conditions of 40° C. and 90% RH in order to exhibit good gas barrier properties. Further, by providing a barrier layer on each film, the weight loss can be preferably 4.0 g/m 2 ⁇ d or less, more preferably 3.0 g/m 2 ⁇ d or less. When the water vapor permeability exceeds 5.0 g/m 2 ⁇ d, it becomes difficult to support applications requiring high gas barrier properties. On the other hand, a preferable lower limit of water vapor permeability is 0.1 g/m 2 ⁇ d or more.
  • the barrier performance is excellent, but it becomes difficult for the residual solvent to permeate to the outside of the bag, and the amount transferred to the contents may increase relatively, so it is not preferable. .
  • the packaging material of the present invention has a water vapor permeability of 5.0 g/m 2 d or less under 40°C x 90% RH after boiling at 95°C for 30 minutes or retorting at 120°C for 30 minutes. It is preferable that there be a certain amount in order to exhibit good gas barrier properties. Further, by providing a barrier layer on each film, the weight loss can be preferably 4.0 g/m 2 ⁇ d or less, more preferably 3.0 g/m 2 ⁇ d or less. When the water vapor permeability exceeds 5.0 g/m 2 ⁇ d, it becomes difficult to support applications requiring high gas barrier properties.
  • a preferable lower limit of water vapor permeability is 0.1 g/m 2 ⁇ d or more. If the water vapor permeability is less than 0.1 g/ m2 , the barrier performance is excellent, but it becomes difficult for the residual solvent to permeate to the outside of the bag, and the amount transferred to the contents may increase relatively, so it is not preferable. .
  • the packaging material of the present invention needs to have straight cutability of 10 mm or less. This is preferable because favorable tearability can be ensured when used as a package.
  • the straight cutting property is preferably 9 mm or less, more preferably 8 mm or less, and even more preferably 7 mm or less. If the straight cutting property is greater than 10 mm, problems such as separation may occur. Details of the method for measuring straight cutability are shown in Examples below.
  • the packaging material of the present invention needs to have a loop stiffness value of 140 mN/25 mm or more.
  • Loop stiffness refers to the repulsive force of the loop, which is measured by forming a loop using a film cut into strips of predetermined dimensions and compressing the loop by a predetermined amount in the radial direction, and is an index representing the stiffness of the film. It is.
  • the loop stiffness value is preferably 145 mN/25 mm or more, more preferably 150 mN/25 mm or more, even more preferably 155 mN/25 mm or more.
  • loop stiffness values can be achieved by adjusting the type and thickness of each film used in the laminate structure, but the stiffness of the heat-sealable resin, which accounts for the main thickness ratio to the whole, has a particularly large effect. .
  • the loop stiffness value can be set to a predetermined value by controlling the planar orientation coefficient of the heat-sealable resin.
  • the heat-sealing strength of the heat-sealing layer resin layers of the packaging material of the present invention when heat-sealing each other at a temperature of 160°C or 170°C, a seal bar pressure of 0.2 MPa, and a sealing time of 2 seconds is 15 N/15 mm or more. preferable. If the heat seal strength is less than 15 N/15 mm, the sealed portion will easily peel off, so the bag cannot be used for applications with a large amount of contents, and its use as a packaging bag will be limited.
  • the heat seal strength is preferably 16 N/15 mm or more, more preferably 17 N/15 mm or more.
  • the packaging material of the present invention preferably has an excellent appearance after heat sealing. Specifically, it is preferable that the seal portion not wrinkle or the bag not be distorted. In order to maintain the appearance after sealing, it is possible to set the heat elongation of the base film to the predetermined range described above, and to set the heat shrinkage rate of the heat-sealable resin film to the predetermined range described above.
  • the monomate ratio is 70% or more. It is preferable. More preferably it is 80% or more, still more preferably 90% or more. By setting the monomate ratio within this range, the packaging material can be configured to be easily recycled. If the monomate ratio is less than 70%, recycling may become difficult due to foreign substances derived from different materials.
  • polypropylene resin As described above, it is preferable to use a polypropylene resin as the polyolefin resin constituting the base film, but if a polypropylene resin is also used for the heat-sealable resin layer, it can be more easily recycled. If all the polyolefin materials used are polypropylene resins, the structure can be made even easier to recycle.
  • the total thickness of each film and adhesive is preferably 20 to 140 ⁇ m. More preferably 25 to 135 ⁇ m, still more preferably 30 to 130 ⁇ m.
  • the total thickness of the packaging material is preferably 20 to 140 ⁇ m. More preferably 25 to 135 ⁇ m, still more preferably 30 to 130 ⁇ m.
  • the total thickness is less than 20 ⁇ m, the bag may not have enough elasticity and may not stand on its own. In addition, the bag may not be strong enough and the bag may tear or become punctured.
  • the total thickness exceeds 140 ⁇ m, it becomes too stiff and difficult to handle, and it also increases the cost of the package, which is not economically preferable.
  • the packaging material of the present invention has excellent heat resistance, straight cutability, stiffness, and barrier performance, and is also excellent in visibility, so it can be used as a variety of packaging materials.
  • packaging bodies include boil or retort sterilization applications, frozen food applications, vacuum packaging applications, and microwave heating applications.
  • the form of a package using the packaging material of the present invention is not particularly limited and can take various forms.
  • Examples of packaging formats include three-sided/four-sided pouches, standing pouches, and spout pouches.
  • the contents to be filled into a packaging bag using the packaging material of the present invention are not particularly limited, and the contents may be liquid, powder, or gel. Moreover, it may be food or non-food.
  • Adhesion amount of coating layer (A), anchor coat layer (C), and protective layer (D) on base film In each example and comparative example, a predetermined coating layer (A) and protective layer (A) were deposited on the base film. Each laminated film obtained at the stage of laminating the anchor coat layer (C) and the protective layer (D) was used as a sample, a 100 mm x 100 mm test piece was cut out from this sample, and a coat layer made of either water, ethanol, or acetone was cut out. The adhesion amount was calculated from the change in mass of the film before and after wiping.
  • Heating elongation rate of base film (%) The heating elongation rate was measured for the base film used in each Example and Comparative Example. The heating elongation rate was determined by TMA measurement using a thermomechanical analyzer ("TMA-60" manufactured by Shimadzu Corporation). For the heat elongation rate in the MD direction, strip-shaped samples were prepared using the base films of Examples and Comparative Examples to have a width of 30 mm in the MD direction and a width of 4 mm in the TD direction. The measurement conditions were: the distance between the chucks was 10 mm, the measurement temperature range was from 30° C. to 150° C., the temperature increase rate was 20° C./min, and the tensile load applied to the sample piece was 0.39 N.
  • the heating elongation rate was determined from the distance between the chucks (mm) before the temperature was raised and the distance between the chucks (mm) when the temperature reached 130°C.
  • strip-shaped samples were prepared using the base films of Examples and Comparative Examples to have a width of 30 mm in the TD direction and a width of 4 mm in the MD direction.
  • the measurement conditions were: the distance between the chucks was 10 mm, the measurement temperature range was from 30° C. to 150° C., the temperature increase rate was 20° C./min, and the tensile load applied to the sample piece was 0.39 N.
  • the heating elongation rate was determined from the distance between the chucks (mm) before the temperature was raised and the distance between the chucks (mm) when the temperature reached 130°C.
  • the base films described in Examples and Comparative Examples are coated with urethane two-component curing adhesives ("Takelac (registered trademark) A525S” manufactured by Mitsui Chemicals, Ltd.) and "Takenate (trademark)".
  • A50 (registered trademark) blended at a ratio of 13.5:1 (mass ratio)) was applied so that the thickness after drying at 80°C was 3 ⁇ m, and then another base film was heated to 60°C. It was dry laminated on a metal roll to form a take-up roll.
  • a similar adhesive was applied to this roll so that the thickness after drying at 80°C was 3 ⁇ m, and then a heat-sealable resin film (described later) was dry-laminated on a metal roll heated to 60°C, and the film was dry-laminated at 40°C for 2 hours.
  • a packaging material for evaluation was obtained by aging for 48 hours.
  • the packaging material prepared in (9) above was subjected to a boiling process in which it was held in hot water at 95°C for 30 minutes, or a retort process in which it was held in hot water at 120°C for 30 minutes, and then heated at 40°C for 1 hour.
  • the oxygen permeability (after boiling, after retorting) of the resulting packaging material after moist heat treatment was measured in the same manner as above.
  • Table 7 the oxygen permeability is expressed as "OTR”
  • the oxygen permeability after boiling is expressed as "OTR after boiling”
  • the oxygen permeability after retorting is expressed as "OTR after retorting”.
  • the packaging material prepared in (9) above was subjected to a boiling process in which it was held in hot water at 95°C for 30 minutes, or a retort process in which it was held in hot water at 120°C for 30 minutes, and then heated at 40°C for 1 hour.
  • the oxygen permeability (after boiling, after retorting) of the resulting packaging material after moist heat treatment was measured in the same manner as above.
  • Table 7 the water vapor permeability is expressed as "WVTR"
  • the water vapor permeability after boiling is expressed as "WVTR after boiling”
  • the water vapor permeability after retorting is expressed as "WVTR after retorting”.
  • Heating elongation rate (%) of the base film peeled off from the packaging material The heating elongation rate of the base film peeled from the packaging material prepared in (9) above was measured.
  • the heating elongation rate was determined by TMA measurement using a thermomechanical analyzer ("TMA-60" manufactured by Shimadzu Corporation).
  • the heating elongation rate in the MD direction was determined by cutting out the packaging materials of Examples and Comparative Examples to have a width of 80 mm in the MD direction and 30 mm in the TD direction, and then peeling the base film between the adhesive layers.
  • a sample was prepared by cutting out a strip having a width of 30 mm and a width of 4 mm in the TD direction.
  • the measurement conditions were: the distance between the chucks was 10 mm, the measurement temperature range was from 30° C. to 150° C., the temperature increase rate was 20° C./min, and the tensile load applied to the sample piece was 0.39 N.
  • the heating elongation rate was determined from the distance between the chucks (mm) before the temperature was raised and the distance between the chucks (mm) when the temperature reached 130°C.
  • the heating elongation rate in the TD direction was determined by cutting out the packaging materials of Examples and Comparative Examples to a width of 80 mm in the TD direction and 30 mm in the MD direction, and then peeling the base film between the adhesive layers.
  • a sample was prepared by cutting out a strip having a width of 30 mm and a width of 4 mm in the MD direction.
  • the measurement conditions were: the distance between the chucks was 10 mm, the measurement temperature range was from 30° C. to 150° C., the temperature increase rate was 20° C./min, and the tensile load applied to the sample piece was 0.39 N.
  • the heating elongation rate was determined from the distance between the chucks (mm) before the temperature was raised and the distance between the chucks (mm) when the temperature reached 130°C.
  • evaluation criteria for visibility and microwave suitability are that the packaging is transparent and does not use aluminum foil or aluminum vapor deposition for the barrier layer. I marked it as ⁇ .
  • Straight cutability of packaging material Straight cutability of the packaging material prepared in (9) above was evaluated.
  • Straight cutability refers to the ability to tear straight in parallel to one direction when the laminate is torn.
  • the measurement was performed using the following method. In Examples and Comparative Examples, straight cutting properties in the stretching direction were exhibited, so measurements were performed in the stretching direction.
  • the laminate was cut into strips with a length of 150 mm in the stretching direction and 60 mm in the direction perpendicular to the measurement direction, and a 30 mm incision was made along the measurement direction from the center of the short side.
  • the sample was torn at a test speed of 200 mm/min ⁇ 10% in accordance with JIS K7128-1:1998.
  • loop stiffness of packaging material The loop stiffness of the packaging material produced in (9) above was measured. A strip of film with a width of 25 mm and 110 mm was cut out so that the longitudinal direction of the strip of film coincided with the direction of the measurement target. The cut out strip-shaped film was set in a loop stiffness tester manufactured by Toyo Seiki Seisakusho Co., Ltd., and the repulsive force was measured. The measurement frequency was 50Hz. The value of the repulsive force (mN/25 mm) obtained in the measurement was taken as the value of loop stiffness.
  • PP-5 propylene polymer
  • the base layer (A) was prepared using a 45 mm extruder, the surface layer (B) was prepared using a 25 mm extruder, and the surface layer (C) (same composition as the surface layer (B)) was prepared using a 20 mm extruder, and the raw resins were heated at 250°C. It was melted and coextruded into a sheet form from a T-die, cooled and solidified so that the surface layer (B) was in contact with a cooling roll at 40°C, and then stretched 4.5 times in the machine direction (MD) at 125°C.
  • MD machine direction
  • both ends of the film in the width direction (TD) are held between clips, and after preheating at 174°C, it is stretched to 8.2 times in the width direction (TD) at 158°C, and 6.7% in the width direction (TD). It was heat-set at 175° C. while being relaxed.
  • the film forming conditions at this time were defined as film forming conditions a. In this way, a biaxially oriented polypropylene film having the structure of surface layer (B)/base layer (A)/surface layer (C) was obtained.
  • the base material layer (A) contained 27.0% by mass of polypropylene homopolymer PP-2 shown in Table 1, 70.0% by mass of polypropylene homopolymer PP-3 shown in Table 1, and ethylene homopolymer ( PE-1) (“SLH218” manufactured by Braskem, MFR: 2.3 g/10 min, melting point: 126°C, biobased degree: 84%, density: 0.916 g/cm 3 ) at a ratio of 3% by mass. Except for this, the conditions were the same as OPP1, and a 20 ⁇ m biaxially oriented polypropylene film was obtained. Details of this configuration are shown in Table 4.
  • the conditions were the same as OPP1 except that a mixture of 52.0% by mass of PP-6, 45.0% by mass of PP-6, and 3.0% by mass of masterbatch A shown in Table 2 was used.
  • An axially oriented polypropylene film was obtained. Details of this configuration are shown in Table 4.
  • the surface layer (B) contains 96.4% by mass of PP-6 and 3.6% by mass of masterbatch A, and the surface layer (C) contains 94.0% by mass of PP-6.
  • the surface layer (B)/base layer (A)/ A biaxially oriented polypropylene film having the structure of the surface layer (C) was obtained. Details of this configuration are shown in Table 4.
  • Coating layer (A) Details of the coating liquid for forming the coating layer (A) used in the present examples and comparative examples are described below. In addition, it was used in Example 1 and Comparative Example 6, and is shown in Table 6.
  • Polyvinyl alcohol resin (a) To 90 parts by mass of purified water, 10 parts by mass of fully saponified polyvinyl alcohol resin (manufactured by Nippon Gosei Kagaku Kogyo Co., Ltd., trade name: G Polymer OKS8049Q, (saponification degree of 99.0% or more, average degree of polymerization 450)) was added. The mixture was heated to 80° C. with stirring, and then stirred for about 1 hour. Thereafter, it was cooled to room temperature, thereby obtaining an almost transparent polyvinyl alcohol solution (PVA solution) (a) with a solid content of 10%.
  • PVA solution polyvinyl alcohol solution
  • Inorganic layered compound dispersion (b) 5 parts by mass of montmorillonite (trade name: Kunipia F, manufactured by Kunimine Kogyo Co., Ltd.), which is an inorganic layered compound, was added to 95 parts by mass of purified water with stirring, and sufficiently dispersed using a homogenizer at a setting of 1500 rpm. Thereafter, the mixture was kept at 23° C. for one day to obtain an inorganic layered compound dispersion (b) with a solid content of 5%.
  • montmorillonite trade name: Kunipia F, manufactured by Kunimine Kogyo Co., Ltd.
  • Coating liquid 1 used for coating layer 1 (coating 1)
  • a coating liquid (resin composition for coating layer) was prepared by mixing each material in the following blending ratio.
  • Coating liquid 2 used for coating layer 2 (coating 2)
  • a coating liquid (resin composition for coating layer) was prepared by mixing each material in the following blending ratio.
  • the coating solution prepared above was applied onto the corona-treated surface of the base film by a gravure roll coating method, pre-dried at 90°C for 4 seconds, and then main-dried at 120°C for 4 seconds to obtain a coating layer. Ta.
  • the amount of coating layer deposited at this time was 0.30 g/m 2 .
  • post-heat treatment was performed at 40°C for 2 days (48 hours). As described above, a laminated film having either coating layer 1 or 2 was produced.
  • inorganic thin film layer (B) The method for producing the inorganic thin film layer (B) used in each Example and Comparative Example is described below.
  • the samples used in Examples 2 to 11 and Comparative Examples 1 to 3, 5, and 8 are shown in Table 6.
  • (Formation of inorganic thin film layer 1) As inorganic thin film layer 1 (vapor deposition 1), a composite oxide layer of silicon dioxide and aluminum oxide was formed on the base film or anchor coat layer by electron beam evaporation. Particulate SiO 2 (purity 99.9%) and Al 2 O 3 (purity 99.9%) of about 3 mm to 5 mm were used as vapor deposition sources.
  • the film thickness of the inorganic thin film layer (SiO 2 /Al 2 O 3 composite oxide layer) in the film thus obtained (inorganic thin film layer/coating layer-containing film) was 13 nm.
  • inorganic thin film layer 2 As the inorganic thin film layer 2 (vapor deposition 2), silicon oxide was deposited on the base film or the anchor coat layer. After reducing the pressure to 10 -3 Pa or less using a small vacuum evaporation device (manufactured by ULVAC Kiko Co., Ltd., VWR-400/ERH), silicon oxide was added to the evaporation source B-110 manufactured by Nilaco from the bottom of the substrate. The film was set and heated to evaporate to form a 30 nm thick silicon oxide film on the film.
  • a small vacuum evaporation device manufactured by ULVAC Kiko Co., Ltd., VWR-400/ERH
  • inorganic thin film layer 3 (vapor deposition 3), metal aluminum was deposited on the base film or the anchor coat layer. After reducing the pressure to 10 -3 Pa or less using a small vacuum evaporation device (manufactured by ULVAC Kiko Co., Ltd., VWR-400/ERH), a 99.9-purity evaporation source CF-305W manufactured by Nilaco was applied from the bottom of the substrate. % aluminum foil was set, and the metal aluminum was heated and evaporated to form a metal aluminum film with a thickness of 30 nm on the film.
  • Anchor coat layer (C) The method for producing the anchor coat layer (C) used in each Example and Comparative Example is described below.
  • polyester resin (a) polyester resin
  • polyester polyol DF-COAT GEC-004C manufactured by DIC Corporation: solid content 30%
  • Polyisocyanate crosslinking agent (b) As the polyisocyanate component, a trimethylolpropane adduct of metaxylylene diisocyanate ("Takenate D-110N" manufactured by Mitsui Chemicals, Inc.: solid content 75%) was used.
  • Silane coupling agent (c) N-2-(aminoethyl)-3-aminopropyltrimethoxysilane (“KBM-603” manufactured by Shin-Etsu Chemical Co., Ltd.) was used as a silane coupling agent.
  • urethane resin (d) As the urethane resin, a polyester urethane resin dispersion ("Takelac (registered trademark) WPB341" manufactured by Mitsui Chemicals, Inc.; solid content: 30%) was used.
  • Takelac (registered trademark) WPB341 manufactured by Mitsui Chemicals, Inc.; solid content: 30%
  • Coating liquid 1 for anchor coat layer-1 A solution of silane coupling agent (c) dissolved in acetone (15% by mass) and isocyanate (b) were mixed at the following ratio and stirred for 10 minutes using a magnetic stirrer. The obtained liquid mixture was diluted with methyl ethyl ketone and 1-methoxy-2-propanol (hereinafter referred to as PGM), and polyester resin (a) was further added to obtain the desired coating liquid 1. The mixing ratio is shown below. Polyester resin (a) 10.62% by mass Isocyanate (b) 4.07% by mass Silane coupling agent (c) *Acetone diluted solution 1.73% by mass Methyl ethyl ketone 69.55% by mass PGM 14.03% by mass
  • Coating liquid 2 for anchor coat layer-2 Coating liquid 2 was prepared by mixing the following coating agents. Water 46.00% by mass Isopropanol 30.00% by mass Urethane resin (d) 24.00% by mass
  • the coating solution 1 described above was applied onto the inorganic thin film layer (B) of the base film by a gravure roll coating method, and dried in a dry oven at 120° C. for 10 seconds to obtain a protective layer 1.
  • the amount of the protective layer deposited at this time was 0.30 g/m 2 .
  • post-heat treatment was performed at 40°C for 2 days (48 hours). In the manner described above, a laminated film provided with a protective layer was produced.
  • /10min ethylene-butene copolymer elastomer resin (manufactured by Mitsui Chemicals, Inc., TAFMER A-4070S) 8.3 parts by mass, MFR 3.0g/10min at 190°C and 2.16kg propylene-butene copolymer elastomer resin ( 2.8 parts by mass of Tafmer XM-7070S (manufactured by Mitsui Chemicals, Inc.) was prepared. Using 100 parts by mass of the preparation, 320 ppm of erucic acid amide as an organic lubricant and silica with an average particle size of 4 ⁇ m as an inorganic anti-blocking agent were added to the resin composition so that the content thereof was 2400 ppm. These raw materials were mixed uniformly to obtain a mixed raw material for producing a polyolefin resin film. The obtained mixed material was used as a mixed raw material for a laminate layer, an intermediate layer, and a heat seal layer, respectively.
  • melt extrusion A three-stage single-screw extruder with a screw diameter of 90 mm was used for the mixed raw material used for the intermediate layer, and a three-stage single-screw extruder with a diameter of 45 mm and a diameter of 65 mm was used for the mixed raw materials for the laminate layer and the heat seal layer, respectively.
  • the laminate layer/intermediate layer/heat seal layer are introduced in this order, and the preland is made into two stages with a width of 800 mm.
  • the shape of the stepped portion is curved to ensure a uniform flow of the molten resin.
  • the sample was introduced into a T-slot type die designed to have a temperature of 230° C. at the outlet of the die.
  • the thickness ratios of the laminate layer/intermediate layer/heat seal layer were 25%/50%/25%, respectively.
  • the mixed raw materials were similarly introduced into each of the laminate layer, intermediate layer, and heat seal layer.
  • the molten resin sheet coming out of the die was cooled with a cooling roll at 21° C. to obtain an unstretched polyolefin resin film having a thickness of 270 ⁇ m.
  • a cooling roll both ends of the film on the cooling roll are fixed with air nozzles, the entire width of the molten resin sheet is pressed onto the cooling roll with an air knife, and at the same time a vacuum chamber is applied to create a space between the molten resin sheet and the cooling roll. Prevents air from getting into the The air nozzles were installed in series at both ends in the film advancing direction. The area around the dice was surrounded by a sheet to prevent wind from hitting the molten resin sheet.
  • the unstretched sheet was introduced into a group of heated rolls, and the sheet was preheated by bringing the sheet into contact with the rolls.
  • the temperature of the preheating roll was 105°C. Multiple rolls were used and both sides of the film were preheated.
  • the unstretched sheet was introduced into a longitudinal stretching machine, and was stretched 4.5 times by a roll speed difference to a thickness of 60 ⁇ m.
  • the temperature of the stretching rolls was 105°C.
  • annealing treatment Heat treatment was performed at 120° C. using an annealing roll while giving a relaxation rate of 5%. Multiple rolls were used to heat treat both sides of the film.
  • Corona treatment Corona treatment was applied to one side (laminated side) of the film.
  • the film forming speed was 20 m/min.
  • the formed film was trimmed at the edges and wound into a roll.
  • the wetting tension on one side of the film (laminated side) was 42 mN/m.
  • Heat-sealable resin films of CPPs 2 to 6 were similarly produced using the method shown in Table 5.
  • Table 5 Tafmer P0480 manufactured by Mitsui Chemicals Co., Ltd. was used as the propylene ethylene block, and EP3721 manufactured by Sumitomo Chemical Co., Ltd. was used as the ethylene propylene copolymer elastomer.
  • the packaging material is provided with a coating layer (A), an anchor coat layer (C), an inorganic thin film layer (B), or a protective layer (D) on each film, and further has a heat-sealable resin film. was created.
  • Example 9 and Comparative Example 7 use two base films, with the upper row representing the first base film and the lower row representing the second base film.
  • the present invention significantly improves gas barrier performance by forming a laminate film in which a specified gas barrier layer tailored to the required performance is laminated onto a base film, and furthermore, by controlling the thermal elongation rate of the laminate film, heat resistance to various processing and sterilization treatments can be ensured. Finally, by laminating a resin layer with excellent straight-line cutting properties and strong stiffness to the aforementioned base film as a heat-sealable resin film, it is possible to provide a packaging material that is both environmentally friendly and highly convenient. Moreover, since the packaging material of the present invention requires few processing steps and can be easily manufactured, it is excellent in both economy and production stability, and it is possible to provide a gas barrier package with uniform characteristics.

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Abstract

The present invention addresses the problem of providing a packaging material that is a laminate of resins that have a low environmental impact and has the stiffness, cuttability, and gas barrier properties desired of a packaging material. The present invention relates to a packaging material that includes: at least one base material film that includes a polyolefin resin as a constituent component; and a heat-sealable resin film. The packaging material is characterized in that at least one of the base material films is a layered base material film that has a gas barrier layer, the thermal elongation of at least one base material film peeled from the packaging material as measured at 130°C using a thermomechanical analysis device is no more than 6% in both the MD direction and the TD direction, the straight cuttability of the packaging material is no more than 10 mm in the MD direction or the TD direction, the value of the loop stiffness of the packaging material is at least 140 mN/25 mm, and the oxygen transmittance of the packaging material at 23°C and 65% RH is no more than 60 ml/m2∙d∙MPa.

Description

包装材料packaging material
　本発明は、食品、医薬品、工業製品等の包装分野に用いられる積層包装材料に関する。更に詳しくは、ガスバリア性、直進カット性、腰感に優れ、利便性を備えた環境対応型のラミネート積層包装材料に関する。 The present invention relates to a laminated packaging material used in the field of packaging foods, pharmaceuticals, industrial products, etc. More specifically, the present invention relates to an environmentally friendly laminated packaging material that has excellent gas barrier properties, straight cutting properties, elasticity, and convenience.
　近年、欧州はじめ世界各国において、使い捨てプラスチック使用削減に向けた規制が強化されている。その背景には、資源循環への国際的な意識の高まりや新興国におけるごみ問題の深刻化がある。そのため、食品、医薬品等に求められるプラスチック製包装材料についても、３Ｒ（Ｒｅｃｙｃｌｅ，Ｒｅｕｓｅ，Ｒｅｄｕｃｅ）の観点から環境対応型の製品が求められている。 In recent years, regulations aimed at reducing the use of single-use plastics have been strengthened in Europe and other countries around the world. Behind this is the growing international awareness of resource recycling and the worsening waste problem in emerging countries. Therefore, environmentally friendly products are required from the viewpoint of the 3Rs (Recycle, Reuse, Reduce) with respect to plastic packaging materials required for foods, medicines, and the like.
　前述の環境に優しい包装材料とするための可能性の一つとして、包装材料がリサイクル可能な同一素材から成ること、すなわち、モノマテリアル化することが積極的に検討されている。モノマテリアル化のための素材としては、例えば、ポリエステル系又はポリオレフィン系の検討がそれぞれ進められている。 As one of the possibilities for making the above-mentioned environmentally friendly packaging materials, it is actively being considered to make packaging materials made of the same recyclable material, that is, to make them monomaterials. As materials for monomaterialization, for example, polyester-based or polyolefin-based materials are being investigated.
　前述のような低環境負荷の包装材料が求められている一方で、利便性のため包装材料自体に求められる特性はますます多機能化しているのが現状である。特に、アルミ箔を使用せず電子レンジでも使用できるようなボイル・レトルトパウチには、袋のガスバリア性、耐熱性、強靭性（耐破袋性や耐ピンホール性）、高いシール性、直進カット性、袋の自立性（腰感）等が一つの包装袋において同時に求められる。これを達成するためには、それぞれ別々の機能を有する異素材を貼り合わせる必要があり、袋の外側に蒸着ポリエステルフィルム、中間層にポリアミドフィルム、内側（内容物側）にポリオレフィン系ヒートシール性樹脂を、接着剤を介してドライラミネートした少なくとも３層以上の構成が一般的となっている。この構成であれば目的とする性能は達成できる可能性があるが、異素材の貼り合わせであることからリサイクル性に劣り、前述の環境にやさしい包装材料とは言えない問題がある。 While there is a demand for packaging materials with a low environmental impact as mentioned above, the current situation is that the characteristics required of the packaging materials themselves are becoming more and more multifunctional for convenience. In particular, boiled retort pouches that do not use aluminum foil and can be used in microwave ovens have gas barrier properties, heat resistance, toughness (breakage resistance and pinhole resistance), high sealability, and straight cuts. In a single packaging bag, characteristics such as flexibility and bag independence (back feel) are required at the same time. In order to achieve this, it is necessary to bond together different materials, each with a different function: a vapor-deposited polyester film for the outside of the bag, a polyamide film for the middle layer, and a polyolefin heat-sealable resin for the inside (content side). It is common to have a structure of at least three or more layers, which are dry laminated using an adhesive. With this configuration, it is possible that the desired performance can be achieved, but since it is a combination of different materials, recyclability is poor, and there is the problem that it cannot be said to be an environmentally friendly packaging material as mentioned above.
　これらの点を考慮し、モノマテリアル化可能な同一素材でも前述のような袋としての多機能性を有するような理想的な包装材料設計ができないかについて検討が進められている。 Taking these points into consideration, studies are underway to see if it is possible to design an ideal packaging material that has the multifunctionality of a bag as described above, even if it is made from the same material that can be made into a monomaterial.
　ポリエステル系モノマテリアル包材設計においては、従来のポリオレフィン系シーラントの代替として、低吸着性・耐熱性を向上させたポリエステル系シーラントが開示されている（例えば、特許文献１参照）。特許文献１のシーラントは、ヒートシール性を有する層とそれ以外の層を分け、これらの層の原料組成をそれぞれ別々に制御することにより、ヒートシール性と耐熱性を満足させている。ただ、ヒートシール性に関しては、ポリオレフィン系シーラントのシール強度に比べると劣っているという問題があり、また耐熱性の面で、ボイルやレトルト処理のような過酷な処理には耐えられないのが現状であった。 In the design of polyester-based monomaterial packaging materials, a polyester-based sealant with improved low adsorption and heat resistance has been disclosed as an alternative to conventional polyolefin-based sealants (see, for example, Patent Document 1). The sealant of Patent Document 1 satisfies heat sealability and heat resistance by separating a layer having heat sealability and other layers and controlling the raw material compositions of these layers separately. However, in terms of heat sealability, there is a problem that the sealing strength is inferior to that of polyolefin sealants, and in terms of heat resistance, it is currently unable to withstand harsh treatments such as boiling and retort processing. Met.
　一方、ポリオレフィン系モノマテリアル包材設計においては、シーラントとしてポリオレフィン系ヒートシール樹脂を用いることができ、前述のポリエステル系シーラントに比べ十分なヒートシール性を確保できる利点がある。シーラントは十分なシール性を発現する必要性からある程度の厚みを有する必要があり、包装体に占める割合は大きい。その点もポリオレフィン系のモノマテリアル包材設計が推進される大きな理由となっている。一方で、ポリオレフィン系包材は、従来のバリア性能を有する包装に比べガスバリア性能に劣る問題があった。ポリプロピレンフィルムは水蒸気バリア性を有するものの、例えば、一般的に水蒸気バリア性が優れるとされる透明無機蒸着ポリエステルフィルムに比べると十分な値ではなく、また酸素バリア性に関しては非常に悪いという問題点があった。 On the other hand, in designing a polyolefin monomaterial packaging material, a polyolefin heat-sealing resin can be used as a sealant, which has the advantage of ensuring sufficient heat-sealability compared to the above-mentioned polyester sealant. The sealant needs to have a certain degree of thickness in order to exhibit sufficient sealing properties, and occupies a large proportion of the package. This point is also a major reason why polyolefin-based monomaterial packaging material design is being promoted. On the other hand, polyolefin packaging materials have a problem of inferior gas barrier performance compared to conventional packaging having barrier performance. Although polypropylene film has water vapor barrier properties, it does not have sufficient water vapor barrier properties compared to, for example, transparent inorganic vapor-deposited polyester films, which are generally considered to have excellent water vapor barrier properties, and it also has very poor oxygen barrier properties. there were.
　これに対し、ポリプロピレンフィルムに、ポリビニルアルコール、エチレンビニルアルコール共重合体、ポリ塩化ビニリデン樹脂、ポリアクリロニトリル等の一般に酸素バリア性が比較的高いと言われる高分子樹脂組成物を積層させたフィルムが使用されてきた（例えば、特許文献２～４参照）。しかしながら、上記のポリビニルアルコールやエチレンビニルアルコール共重合体の高分子樹脂組成物を用いてなるガスバリア性コートフィルムは湿度依存性が大きいため、高湿下においてガスバリア性の低下が見られ、ボイルやレトルト等の殺菌処理に耐え得る耐湿熱性も有していなかった。またポリ塩化ビニリデン樹脂、ポリアクリロニトリルは、湿度依存性が低いが、絶対値としてのバリア値が不十分であること、廃棄・焼却の際に有害物質が発生する危険性が高いこと等の問題があった。さらに用いられているポリプロピレンフィルムは耐熱性が十分でなく、コート加工、印刷やラミネート加工、殺菌処理の際の付加熱によりフィルムが伸縮することで外観上のシワや性能低下につながる問題があった。 In contrast, a film is used in which a polypropylene film is laminated with a polymer resin composition that is generally said to have relatively high oxygen barrier properties, such as polyvinyl alcohol, ethylene vinyl alcohol copolymer, polyvinylidene chloride resin, and polyacrylonitrile. (For example, see Patent Documents 2 to 4). However, gas barrier coating films made using the above-mentioned polymeric resin compositions of polyvinyl alcohol or ethylene vinyl alcohol copolymers are highly dependent on humidity, so gas barrier properties deteriorate under high humidity conditions, and boiling or retorting It also did not have the heat and humidity resistance to withstand sterilization treatments such as sterilization. Furthermore, although polyvinylidene chloride resin and polyacrylonitrile have low humidity dependence, they have problems such as insufficient barrier value as an absolute value and a high risk of generating harmful substances when disposed of or incinerated. there were. Furthermore, the polypropylene film used does not have sufficient heat resistance, and the added heat during coating, printing, laminating, and sterilization processing causes the film to expand and contract, leading to wrinkles in appearance and a decline in performance. .
　ポリプロピレンフィルムのガスバリア性向上に関し、無機薄膜を積層することで湿度依存性がなく安定したガスバリア性能を発現させる試みも行われている（例えば、特許文献５）。しかし、従来のポリエステル蒸着フィルムに対してガスバリア性能の絶対値（特に酸素バリア性）が劣ることや、前述のコートタイプバリアフィルムに比べて物理的ダメージに弱い等の問題もあった。また、ポリオレフィン系シーラントに蒸着を施したバリア材料も検討されているが（例えば、特許文献６）、水蒸気バリア性能は発現するものの酸素バリア性が十分でないこと等の課題があった。 With regard to improving the gas barrier properties of polypropylene films, attempts have been made to develop stable gas barrier properties without humidity dependence by laminating inorganic thin films (for example, Patent Document 5). However, there were problems such as the absolute value of gas barrier performance (particularly oxygen barrier property) being inferior to conventional polyester vapor-deposited films, and the film being more susceptible to physical damage than the above-mentioned coat-type barrier film. Barrier materials made by vapor-depositing polyolefin sealants have also been studied (for example, Patent Document 6), but although they exhibit water vapor barrier performance, they have problems such as insufficient oxygen barrier properties.
　ポリオレフィン系モノマテリアル包材を近年の社会背景から需要が伸びているボイル・レトルトパウチに展開しようとした場合、前述のバリア性能の課題に加えて、袋のカット性についても考慮する必要がある。一般的に、パウチから食品内容物を取り出す際は、包装袋の周辺のシール部分に入れられた切込み部分、いわゆるノッチ部分から手で包装袋を引裂いてカットすることが多いが、従来の積層体を使用した場合、包装袋の一辺、通常は水平方向に対して平行に引裂くことができず、斜めに開封されてしまったり、包装袋の表面と裏面の積層体で裂けの進行方向が上下逆になる現象、いわゆる泣別れが発生してしまい、食品内容物が取り出しにくくなり、食品内容物で手や服が汚れたり、内容物が加熱されていた場合は火傷等をしたりする恐れがあった。 If polyolefin-based monomaterial packaging materials are to be used in boiled retort pouches, the demand for which has been growing due to recent social circumstances, in addition to the barrier performance issues mentioned above, it is also necessary to consider the cuttability of the bag. Generally, when removing food contents from a pouch, the packaging bag is often cut by hand by tearing it from the so-called notch, which is a notch made in the seal around the packaging bag. When using a packaging bag, it may not be possible to tear it parallel to one side, usually horizontally, and the bag may be opened diagonally, or the direction of tearing may be up or down in the laminate on the front and back sides of the packaging bag. The opposite phenomenon, so-called separation, may occur, making it difficult to remove the food contents, staining your hands and clothes with the food contents, and risking burns if the contents have been heated. there were.
　包装袋を包装袋の一辺に対して平行に引裂くことが困難である理由は、積層体に用いる基材フィルムに歪みがあること、すなわち基材フィルムの分子配向軸方向が包装体の一辺に対して平行でないからである。 The reason why it is difficult to tear a packaging bag parallel to one side of the packaging bag is that the base film used for the laminate is distorted. This is because they are not parallel to each other.
　基材フィルムの分子配向軸方向を包装袋の引裂き方向と同じにすることができればこのような問題は発生しない。製造された広幅の延伸フィルムの幅方向中央部の分子配向軸方向はフィルムの走行方向と一致しており包装袋の一辺に対して平行に引裂くことが可能である。ところが、フィルムの幅方向端部では分子配向軸方向が傾いてしまい、包装袋の引裂き方向は傾いてしまう。フィルムの幅方向端部を使用した基材フィルムを完全に避けて調達することは現実的ではない上に、基材フィルムの生産速度高速化や広幅化に伴い、歪みの程度は従来よりもさらに大きくなる傾向にある。これに対し、基材フィルムと積層されるポリオレフィン系ヒートシール性樹脂の工夫により、こういった問題を解決することが試みられている。 If the direction of the molecular orientation axis of the base film can be made the same as the tearing direction of the packaging bag, such a problem will not occur. The direction of the molecular orientation axis at the widthwise central portion of the produced wide stretched film coincides with the running direction of the film, allowing it to be torn parallel to one side of the packaging bag. However, at the ends of the film in the width direction, the direction of the molecular orientation axis is tilted, and the tearing direction of the packaging bag is tilted. It is not realistic to completely avoid procuring a base film that uses the edges of the film in the width direction, and as the production speed and width of the base film increases, the degree of distortion will become even greater than before. It tends to get bigger. In contrast, attempts have been made to solve these problems by devising a polyolefin heat-sealing resin that is laminated with the base film.
　カット性を改善したヒートシール性樹脂として、エチレン－プロピレンブロック共重合体とエチレン－プロピレン共重合体を含むポリオレフィン系樹脂シートを３．０倍以下で一軸延伸することにより得られたフィルムが知られている（例えば、特許文献７の実施例１、２参照）。しかし、引裂強度に改善の余地があり、また泣別れが発生しやすいという問題点があった。さらに基材層としてはポリオレフィン以外の異素材フィルムが、バリア層としてはアルミ箔が用いられており、リサイクル使用ができないものであった。 A film obtained by uniaxially stretching a polyolefin resin sheet containing an ethylene-propylene block copolymer and an ethylene-propylene copolymer at a ratio of 3.0 times or less is known as a heat-sealable resin with improved cuttability. (For example, see Examples 1 and 2 of Patent Document 7). However, there was still room for improvement in tear strength, and there was a problem in that tearing was likely to occur. Furthermore, a film made of a different material other than polyolefin was used as the base layer, and aluminum foil was used as the barrier layer, which could not be recycled.
　さらに、ポリオレフィン系モノマテリアル包材をボイル・レトルトパウチに展開しようとした場合、前述のバリア性能やカット性の課題に加えて、袋の自立性についても考慮する必要がある。従来の異素材からなるレトルトパウチにおいては、袋に自立性を持たせるために、腰感の強い二軸延伸ポリエステルフィルムや二軸延伸ナイロンフィルムを積層している。これに対して、オレフィン系フィルムは一般に剛性が小さいため袋の自立に必要な腰感を確保できないおそれがあった。 Furthermore, when attempting to develop polyolefin-based monomaterial packaging materials into boiled retort pouches, in addition to the aforementioned barrier performance and cuttability issues, it is also necessary to consider the self-supporting nature of the bag. In conventional retort pouches made of different materials, biaxially oriented polyester films or biaxially oriented nylon films with strong stiffness are laminated to give the bag self-reliance. On the other hand, since olefin films generally have low rigidity, they may not be able to secure the stiffness necessary for the bag to stand on its own.
特開２０１７－１６５０５９号公報JP 2017-165059 Publication 特開２０００－５２５０１号公報Japanese Patent Application Publication No. 2000-52501 特開平４－３５９０３３号公報Japanese Patent Application Publication No. 4-359033 特開２００３－２３１２２１号公報JP2003-231221A 国際公開第２０１７／２２１７８１号International Publication No. 2017/221781 特許第３３１８４７９号公報Patent No. 3318479 特許第５７９０４９７号公報Patent No. 5790497
　上記特許文献では、包装材料をモノマテリアル化することと、包材に求められる各種性能、特にガスバリア性やカット性、腰感との両立が難しく、環境にやさしくかつ利便性も高い包装材料を設計することができていなかった。 In the above patent document, it is difficult to make packaging materials into monomaterials and to achieve various performances required of packaging materials, especially gas barrier properties, cutability, and elasticity, and to design packaging materials that are both environmentally friendly and highly convenient. I wasn't able to do that.
　本発明は、かかる従来技術の問題点を背景になされたものである。すなわち、本発明の課題は、環境負荷が少ない樹脂種から構成されたラミネート構成を形成することができるとともに、包装材料に求められるガスバリア性とカット性、及び腰感の３つの性能を全て備えた包装材料を提供することである。 The present invention was made against the background of the problems of the prior art. In other words, the object of the present invention is to create a packaging that can form a laminate structure made of a resin type that has a low environmental impact, and that also has all three performances required of a packaging material: gas barrier properties, cutability, and firmness. The goal is to provide materials.
　本発明者らは、要求される性能に合わせた所定のガスバリア層を基材フィルム上に積層した積層フィルムとすることでガスバリア性能を大きく向上させ、さらに前記積層フィルムの加熱伸び率を制御することで各種加工や殺菌処理に対する耐熱性を確保でき、最終的にヒートシール性樹脂フィルムとして直進カット性に優れ腰感の強い樹脂層を前述の基材フィルムと貼り合わせることで、環境にやさしくかつ利便性も高い包装材料を提供できることを見出して本発明を完成するに至った。 The present inventors have developed a laminated film in which a predetermined gas barrier layer tailored to the required performance is laminated on a base film, thereby greatly improving gas barrier performance, and further controlling the heating elongation rate of the laminated film. It is possible to ensure heat resistance against various processing and sterilization treatments, and finally, by laminating the resin layer with the above-mentioned base film as a heat-sealable resin film that has excellent straight cutability and has a strong feel, it is environmentally friendly and convenient. The present invention was completed by discovering that it is possible to provide a packaging material with high properties.
　すなわち本発明は、以下の構成からなる。
　１．ポリオレフィン系樹脂を構成成分とする基材フィルムを少なくとも１枚と、ヒートシール性樹脂フィルムとを有する包装材料であって、
　前記基材フィルムのうち少なくとも１枚はガスバリア層を有する積層基材フィルムであって、
　前記包装材料から剥離した基材フィルムの少なくとも１枚が、熱機械分析装置により測定した１３０℃における加熱伸び率がＭＤ方向、ＴＤ方向のいずれも６％以下であり、
　前記包装材料の直進カット性がＭＤ方向又はＴＤ方向において１０ｍｍ以下、かつ、ループスティフネスの値が１４０ｍＮ／２５ｍｍ以上であり、
　２３℃×６５％ＲＨ環境下における酸素透過度が６０ｍｌ／ｍ２・ｄ・ＭＰａ以下であることを特徴とする包装材料。
　２．前記ヒートシール性樹脂フィルムは、プロピレン－αオレフィンランダム共重合体を含み、さらにエチレン－プロピレン共重合エラストマー、エチレン－ブテン共重合エラストマー、プロピレン－ブテン共重合エラストマーから選ばれる少なくとも１つの成分を含むことを特徴とする１．に記載の包装材料。
　３．前記ガスバリア層が、アルミニウム、酸化アルミニウム、酸化ケイ素、及び酸化ケイ素と酸化アルミニウムの複合酸化物からなる群より選択されてなる材料から形成される無機薄膜層であることを特徴とする１．又は２．に記載の包装材料。
　４．前記ガスバリア層が、ポリビニルアルコール樹脂、ポリエステル樹脂、及びポリウレタン樹脂からなる群より選択されてなる樹脂を構成成分として含む被覆層であることを特徴とする１．～３．のいずれかに記載の包装材料。
　５．前記基材フィルムとガスバリア層との間にアンカーコート層が積層されることを特徴とする１．～４．のいずれかに記載の包装材料。
　６．前記ガスバリア層の上に保護層が積層されることを特徴とする１．～５．のいずれかに記載の包装材料。
　７．前記基材フィルムを２枚以上用いることを特徴とする１．～６．のいずれかに記載の包装材料。
　８．前記基材フィルムを構成するポリオレフィン樹脂のうち、植物由来のポリエチレン樹脂を１質量％以上２５質量％以下含むことを特徴とする１．～７．のいずれかに記載の包装材料。
　９．ボイル又はレトルト用に使用されることを特徴とする１．～８．のいずれかに記載の包装材料。
　１０．電子レンジ加熱用に使用されることを特徴とする１．～８．のいずれかに記載の包装材料。
　１１．前記１．～１０．のいずれかに記載の包装材料を用いて構成される包装袋。
　１２．前記１．～１０．のいずれかに記載の包装材料、又は１１．に記載の包装袋を使用して被包装物が包装されてなる包装体。 That is, the present invention consists of the following configuration.
1. A packaging material comprising at least one base film containing a polyolefin resin as a constituent component and a heat-sealable resin film,
At least one of the base films is a laminated base film having a gas barrier layer,
At least one of the base films peeled from the packaging material has a heating elongation rate at 130°C measured by a thermomechanical analyzer of 6% or less in both the MD direction and the TD direction,
The straight cutting property of the packaging material is 10 mm or less in the MD direction or the TD direction, and the loop stiffness value is 140 mN/25 mm or more,
A packaging material characterized by an oxygen permeability of 60 ml/m 2 ·d·MPa or less under a 23° C. x 65% RH environment.
2. The heat-sealable resin film contains a propylene-α olefin random copolymer, and further contains at least one component selected from an ethylene-propylene copolymer elastomer, an ethylene-butene copolymer elastomer, and a propylene-butene copolymer elastomer. 1. Packaging materials listed in.
3. 1. The gas barrier layer is an inorganic thin film layer formed from a material selected from the group consisting of aluminum, aluminum oxide, silicon oxide, and a composite oxide of silicon oxide and aluminum oxide. Or 2. Packaging materials listed in.
4. 1. The gas barrier layer is a coating layer containing as a constituent component a resin selected from the group consisting of polyvinyl alcohol resin, polyester resin, and polyurethane resin. ~3. Packaging materials listed in any of the above.
5. 1. An anchor coat layer is laminated between the base film and the gas barrier layer. ~4. Packaging materials listed in any of the above.
6. 1. A protective layer is laminated on the gas barrier layer. ~5. Packaging materials listed in any of the above.
7. 1. characterized in that two or more of the base films are used; ~6. Packaging materials listed in any of the above.
8. 1. The polyolefin resin constituting the base film contains 1% by mass or more and 25% by mass or less of a plant-derived polyethylene resin. ~7. Packaging materials listed in any of the above.
9. 1. It is characterized by being used for boiling or retorting. ~8. Packaging materials listed in any of the above.
10. 1. It is characterized by being used for heating in a microwave oven. ~8. Packaging materials listed in any of the above.
11. Said 1. ~10. A packaging bag constructed using the packaging material described in any of the above.
12. Said 1. ~10. The packaging material according to any one of 11. or 11. A package in which an item to be packaged is packaged using the packaging bag described in .
　本発明者らは、かかる技術によって、環境に配慮しつつ、包装材料に求められるバリア性とカット性、及び腰感等の必要性能を有する包装材料を提供することが可能となった。 Through this technology, the present inventors have been able to provide a packaging material that has the required performance such as barrier properties, cuttability, and elasticity required for packaging materials, while being environmentally friendly.
　本発明の包装材料は、ポリオレフィン系樹脂を構成成分とする基材フィルムを少なくとも１枚と、ヒートシール性樹脂フィルムとを有する包装材料であって、前記基材フィルムのうち少なくとも１枚はガスバリア層を有する積層基材フィルムであって、前記包装材料から剥離した基材フィルムの少なくとも１枚が、熱機械分析装置により測定した１３０℃における加熱伸び率がＭＤ方向、ＴＤ方向のいずれも６％以下であり、前記包装材料の直進カット性がＭＤ方向又はＴＤ方向において１０ｍｍ以下かつ、ループスティフネスの値が１４０ｍＮ／２５ｍｍ以上であり、２３℃×６５％ＲＨ環境下における酸素透過度が６０ｍｌ／ｍ２・ｄ・ＭＰａ以下であることを特徴とする包装材料である。なお、前記基材フィルムは、ポリオレフィン系樹脂を主たる構成成分とすることが好ましく、前記の「主たる構成成分とする」とは、構成成分中に５０質量％以上含有することをさし、好ましくは７０質量％以上であり、より好ましくは８０質量％以上であり、さらに好ましくは９０質量％以上である。 The packaging material of the present invention is a packaging material having at least one base film containing a polyolefin resin as a constituent component and a heat-sealable resin film, wherein at least one of the base films has a gas barrier layer. , wherein at least one of the base films peeled from the packaging material has a heat elongation rate of 6% or less at 130°C in both the MD direction and the TD direction as measured by a thermomechanical analyzer. and the packaging material has straight cutability of 10 mm or less in the MD direction or TD direction, a loop stiffness value of 140 mN/25 mm or more, and an oxygen permeability of 60 ml/m 2 in an environment of 23° C. x 65% RH.・It is a packaging material characterized by having a pressure of d・MPa or less. In addition, it is preferable that the base film has a polyolefin resin as a main constituent component, and the above-mentioned "main constituent component" refers to containing 50% by mass or more in the constituent components, and preferably The content is 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more.
　以下、本発明について詳細に説明する。 Hereinafter, the present invention will be explained in detail.
［基材フィルム］
　本発明の包装材料は、ポリオレフィン系樹脂を構成成分とする基材フィルムを備えるものである。基材フィルムは、ポリプロピレン系樹脂を主たる構成成分とする基材フィルム（以下、ポリプロピレン系樹脂フィルムと称する）が好ましく、延伸フィルムであることがより好ましい。本発明で基材フィルムとして用いるポリプロピレン系樹脂延伸フィルムは、二軸延伸フィルムであることが好ましい。二軸延伸ポリプロピレン系樹脂フィルムとしては、公知の二軸延伸ポリプロピレン系樹脂フィルムを使用することが可能であり、その原料、混合比率等は特に限定されない。例えば、ポリプロピレンホモポリマー（プロピレン単独重合体）であるほか、プロピレンを主成分として、エチレン、ブテン、ペンテン、ヘキセン等のα－オレフィンから選ばれる１種又は２種以上とのランダム共童合体やブロック共重合体等、あるいはこれらの重合体を２種以上混合した混合体によるものであってもよい。また物性改質を目的として、酸化防止剤、帯電防止剤、可塑剤等、公知の添加剤が添加されていてもよく、例えば、石油樹脂やテルペン樹脂等が添加されていてもよい。 [Base film]
The packaging material of the present invention includes a base film containing a polyolefin resin as a constituent component. The base film is preferably a base film containing a polypropylene resin as a main component (hereinafter referred to as a polypropylene resin film), and more preferably a stretched film. The stretched polypropylene resin film used as the base film in the present invention is preferably a biaxially stretched film. As the biaxially oriented polypropylene resin film, a known biaxially oriented polypropylene resin film can be used, and the raw materials, mixing ratio, etc. thereof are not particularly limited. For example, in addition to polypropylene homopolymers (propylene homopolymers), random copolymerizations and blocks with propylene as the main component and one or more α-olefins such as ethylene, butene, pentene, hexene, etc. It may be a copolymer or a mixture of two or more of these polymers. Further, for the purpose of improving physical properties, known additives such as antioxidants, antistatic agents, plasticizers, etc. may be added, and for example, petroleum resins, terpene resins, etc. may be added.
　本発明において、基材フィルムを構成するポリプロピレン系樹脂としては、実質的にプロピレン以外のコモノマーを含まないプロピレン単独重合体が好ましく、コモノマーを含む場合であっても、コモノマー量は、ポリプロピレン系樹脂を構成する全単量体中０．５モル％以下であることが好ましい。コモノマー量の上限は、より好ましくは０．３モル％であり、さらに好ましくは０．１モル％である。上記範囲であると結晶性が向上し、高温での寸法変化が小さくなり、耐熱性が向上する。なお、結晶性を著しく低下させない範囲内において、微量であればコモノマーが含まれていてもよい。 In the present invention, the polypropylene resin constituting the base film is preferably a propylene homopolymer that does not substantially contain comonomers other than propylene. It is preferable that the amount is 0.5 mol% or less in all the constituent monomers. The upper limit of the comonomer amount is more preferably 0.3 mol%, and even more preferably 0.1 mol%. Within the above range, crystallinity is improved, dimensional changes at high temperatures are reduced, and heat resistance is improved. Note that a comonomer may be included in a trace amount within a range that does not significantly reduce crystallinity.
　また、本発明で用いる二軸延伸ポリプロピレン系樹脂フィルムは、単層フィルムであってもよく、積層型フィルムであってもよく、例えば、基材層と１層以上の表面層を含む積層型フィルムとすることができ、基材層の両面に表面層を有する積層フィルム（表面層／基材層／表面層）とすることが好ましい。ただし、本発明の目的を達成するためには積層型フィルムであることが好ましく、積層体の種類、積層数、積層方法等は特に限定されず、公知の方法から任意に選択することができるが、基材フィルム表面の表面粗さや柔軟性をコントロールすることで（すなわち、表面層／基材層／表面層の積層フィルムとすることで）、ラミネート強度やコート剤等の接着強度を向上させることが好ましい。 Further, the biaxially oriented polypropylene resin film used in the present invention may be a single layer film or a laminated film, for example, a laminated film comprising a base layer and one or more surface layers. It is preferable to use a laminated film (surface layer/base layer/surface layer) having surface layers on both sides of the base layer. However, in order to achieve the purpose of the present invention, a laminated film is preferable, and the type of laminate, number of layers, lamination method, etc. are not particularly limited, and can be arbitrarily selected from known methods. By controlling the surface roughness and flexibility of the base film surface (i.e., by creating a laminated film of surface layer/base layer/surface layer), the lamination strength and adhesive strength of coating agents, etc. can be improved. is preferred.
　本発明では、基材フィルムのラミネート強度や、無機薄膜層、コート剤等との界面接着強度を向上させる手段として、基材フィルムの表面層を構成するポリプロピレン系樹脂として、メルトフローレート（ＭＦＲ）が異なる２種以上のポリプロピレン系樹脂の混合物を使用しても良い。 In the present invention, as a means to improve the lamination strength of the base film and the interfacial adhesive strength with an inorganic thin film layer, a coating agent, etc., melt flow rate (MFR) is used as a polypropylene resin constituting the surface layer of the base film. A mixture of two or more types of polypropylene resins having different properties may be used.
　ポリプロピレン系樹脂の混合物中の２種以上のポリプロピレン系樹脂のメルトフローレート（ＭＦＲ）の差が小さい方が、それぞれのポリプロピレン系樹脂の結晶化速度や結晶化度が大きく異ならず、表面に微少な凹凸が生成しやすいものと推測している。但し、フィルムの製造時に未延伸シートの冷却速度が遅かったりすると、球晶による表面凹凸が大きくなること、縦延伸あるいは横延伸時に延伸温度が高すぎて表面凹凸が大きくなりやすいため、注意が必要である。 The smaller the difference in melt flow rate (MFR) between two or more polypropylene resins in a mixture of polypropylene resins, the less the crystallization rate and degree of crystallinity of each polypropylene resin will differ greatly, and the smaller the It is assumed that unevenness is likely to occur. However, care must be taken because if the cooling rate of the unstretched sheet is slow during film production, surface irregularities due to spherulites will become large, and the stretching temperature during longitudinal or transverse stretching will be too high, which will easily increase surface unevenness. It is.
　それぞれのポリプロピレン系樹脂としては、共重合成分を含まないポリプロピレン単独重合体、及びエチレン及び／又は炭素数４以上のα－オレフィンを５．０モル％以下で共重合したポリプロピレン樹脂を用いることができる。共重合したポリプロピレン樹脂の共重合成分は４．０モル％以下が好ましく、３．５モル％以下がより好ましい。共重合したポリプロピレン樹脂の共重合成分は１．０モル％以上が好ましく、１．５モル％以上がより好ましく、２．０モル％以上がさらに好ましく、２．５モル％以上が特に好ましい。炭素数４以上のα－オレフィンとしては、１－ブテン、１－ヘキセン、４－メチル・１－ペンテン、１－オクテン等が挙げられる。また、その他の共重合成分として極性を有するマレイン酸等を使用しても良い。 As each polypropylene resin, a polypropylene homopolymer containing no copolymerization component, and a polypropylene resin copolymerized with ethylene and/or an α-olefin having 4 or more carbon atoms at 5.0 mol% or less can be used. . The copolymerization component of the copolymerized polypropylene resin is preferably 4.0 mol% or less, more preferably 3.5 mol% or less. The copolymerization component of the copolymerized polypropylene resin is preferably 1.0 mol% or more, more preferably 1.5 mol% or more, even more preferably 2.0 mol% or more, and particularly preferably 2.5 mol% or more. Examples of the α-olefin having 4 or more carbon atoms include 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene. Furthermore, maleic acid or the like having polarity may be used as another copolymerization component.
　基材フィルムを構成するポリプロピレン系樹脂のキシレン可溶分の下限は、現実的な面から、好ましくは０．１質量％である。キシレン可溶分の上限は好ましくは７質量％であり、より好ましくは６質量％であり、さらに好ましくは５質量％である。上記範囲であると結晶性が向上し、加熱時の寸法変化がより小さくなり、耐熱性が向上するため、好ましい。 From a practical standpoint, the lower limit of the xylene soluble content of the polypropylene resin constituting the base film is preferably 0.1% by mass. The upper limit of the xylene soluble content is preferably 7% by mass, more preferably 6% by mass, and still more preferably 5% by mass. The above range is preferable because crystallinity improves, dimensional changes during heating become smaller, and heat resistance improves.
　本発明において、ポリプロピレン系樹脂のメルトフローレート（ＭＦＲ）（２３０℃、２．１６ｋｇｆ）の下限は０．５ｇ／１０分であることが好ましい。ＭＦＲの下限は、より好ましくは１．０ｇ／１０分であり、さらに好ましくは２．０ｇ／１０分であり、特に好ましくは４．０ｇ／１０分であり、最も好ましくは６．０ｇ／１０分である。上記範囲であると機械的負荷が小さく、押出や延伸が容易となる。ＭＦＲの上限は２０ｇ／１０分であることが好ましい。ＭＦＲの上限は、より好ましくは１７ｇ／１０分であり、さらに好ましくは１６ｇ／１０分であり、特に好ましくは１５ｇ／１０分である。上記範囲であると延伸が容易となったり、厚み斑が小さくなったり、延伸温度や熱固定温度が上げられやすく加熱時の寸法変化がより小さくなり、耐熱性が向上するため、好ましい。 In the present invention, the lower limit of the melt flow rate (MFR) (230°C, 2.16 kgf) of the polypropylene resin is preferably 0.5 g/10 minutes. The lower limit of MFR is more preferably 1.0 g/10 minutes, still more preferably 2.0 g/10 minutes, particularly preferably 4.0 g/10 minutes, and most preferably 6.0 g/10 minutes. It is. Within the above range, the mechanical load is small and extrusion and stretching become easy. The upper limit of MFR is preferably 20 g/10 minutes. The upper limit of MFR is more preferably 17 g/10 minutes, still more preferably 16 g/10 minutes, particularly preferably 15 g/10 minutes. A range within the above range is preferable because it facilitates stretching, reduces thickness unevenness, makes it easier to raise the stretching temperature and heat setting temperature, reduces dimensional changes during heating, and improves heat resistance.
　前記基材フィルムは耐熱性の点から、長手方向（ＭＤ方向）もしくは横方向（ＴＤ方向）の一軸延伸フィルムでも良いが、二軸延伸フィルムであることが好ましい。本発明では、前記の好ましい原料を使用して少なくとも一軸に延伸することで、従来のポリプロピレンフィルムでは予想できなかった加熱時の寸法変化がより小さい、高度な耐熱性を具備したフィルムを得ることができる。延伸方法としては、同時二軸延伸法、逐次二軸延伸法等が挙げられるが、平面性、寸法安定性、厚みムラ等を良好とする点から逐次二軸延伸法が好ましい。 From the viewpoint of heat resistance, the base film may be a uniaxially stretched film in the longitudinal direction (MD direction) or the transverse direction (TD direction), but is preferably a biaxially stretched film. In the present invention, by using the above-mentioned preferred raw materials and stretching at least uniaxially, it is possible to obtain a film with a high degree of heat resistance and a smaller dimensional change during heating than could be expected with conventional polypropylene films. can. Examples of the stretching method include a simultaneous biaxial stretching method and a sequential biaxial stretching method, but the sequential biaxial stretching method is preferred from the viewpoint of improving flatness, dimensional stability, thickness unevenness, and the like.
　逐次二軸延伸法としては、ポリプロピレン系樹脂を単軸又は二軸の押出機で樹脂温度が２００℃以上２８０℃以下となるようにして加熱溶融させ、Ｔダイよりシート状にし、１０℃以上１００℃以下の温度のチルロール上に押出して未延伸シートを得る。ついで、長手方向（ＭＤ方向）に１２０℃以上１６５℃以下で、３．０倍以上８．０倍以下にロール延伸し、引き続き、テンターで予熱後、横方向（ＴＤ方向）に１５５℃以上１７５℃以下温度で４．０倍以上２０．０倍以下に延伸することができる。さらに、二軸延伸後に１６５℃以上１７５℃以下の温度で１％以上１５％以下のリラックスを許しながら、熱固定処理を行うことができる。 For the sequential biaxial stretching method, polypropylene resin is heated and melted using a single-screw or twin-screw extruder at a resin temperature of 200°C or higher and 280°C or lower, formed into a sheet using a T-die, and then heated at a temperature of 10°C or higher and 100°C or higher. An unstretched sheet is obtained by extrusion onto a chill roll at a temperature of 0.degree. C. or below. Next, roll stretching is performed in the longitudinal direction (MD direction) at 120° C. or more and 165° C. or less to 3.0 times or more and 8.0 times or less, and then, after preheating with a tenter, it is stretched in the transverse direction (TD direction) at 155° C. or more and 175° C. It can be stretched 4.0 times or more and 20.0 times or less at a temperature of .degree. C. or lower. Further, after biaxial stretching, heat setting treatment can be performed at a temperature of 165° C. or more and 175° C. or less while allowing relaxation of 1% or more and 15% or less.
　本発明では、加熱時の寸法変化の指標として、熱機械分析装置により測定した前記基材フィルムの１３０℃での加熱伸び率が、ＭＤ方向、ＴＤ方向のいずれも１０％以下であることが好ましい。これにより、後述するガスバリア層の加工工程やラミネート加工工程、さらにはシール工程において、フィルムに張力がかかった状態での熱負荷による基材変形を低減できる。その結果として、ガスバリア性能や接着性能、さらにはシワタルミ等の外観品位をより向上することができる。１３０℃でのＭＤ方向、及びＴＤ方向の加熱伸び率は、好ましくは９．５％以下、より好ましくは９．０％以下、さらに好ましくは８．５％以下であり、下限は０％が好ましい。１３０℃での加熱伸び率が前記範囲外の場合は、張力負荷時の熱によって積層フィルムが変形してガスバリア性を低下させたり、フィルムの寸法変化がおき外観品位が低下する場合がある。本発明において、加熱伸び率は熱機械分析装置（ＴＭＡ）法で測定される値であり、より詳細には実施例に記載の方法による。 In the present invention, as an index of dimensional change during heating, it is preferable that the heating elongation rate of the base film at 130°C measured by a thermomechanical analyzer is 10% or less in both the MD direction and the TD direction. . This makes it possible to reduce deformation of the base material due to heat load when tension is applied to the film in the gas barrier layer processing step, lamination processing step, and sealing step, which will be described later. As a result, gas barrier performance, adhesive performance, and appearance quality such as wrinkling can be further improved. The heat elongation rate in the MD direction and the TD direction at 130°C is preferably 9.5% or less, more preferably 9.0% or less, even more preferably 8.5% or less, and the lower limit is preferably 0%. . If the heating elongation rate at 130° C. is outside the above range, the laminated film may be deformed by the heat during tension loading, resulting in a decrease in gas barrier properties, or the film may undergo dimensional changes, resulting in a decrease in appearance quality. In the present invention, the heating elongation rate is a value measured by a thermomechanical analyzer (TMA) method, and more specifically by the method described in Examples.
　本発明の基材フィルムにおいて前述の加熱伸び率を前述の範囲とするためには、以下の方法で製膜されることが好ましい。
　まず、長手方向（ＭＤ）の延伸温度の上限は好ましくはフィルム融点（Ｔｍ）－７℃であり、より好ましくはＴｍ－１０℃であり、さらに好ましくはＴｍ－１２℃である。上記範囲であると加熱伸び率を小さくしやすく、また延伸ロールに融着し延伸しにくくなるため、品位が低下することも少ない。
　なお、長手方向の延伸は３対以上の延伸ロールを使用して、２段階以上の多段階に分けて延伸してもよい。多段階に分けることで延伸時の歪みを低減できることから加熱伸び率を小さくしやすい。 In order to make the above-mentioned heating elongation rate in the base film of the present invention within the above-mentioned range, it is preferable to form the film by the following method.
First, the upper limit of the stretching temperature in the longitudinal direction (MD) is preferably -7°C, more preferably Tm -10°C, and even more preferably Tm -12°C. If it is within the above range, the heating elongation rate can be easily reduced, and since it is difficult to fuse to the stretching rolls and stretch, the quality is less likely to deteriorate.
Note that the stretching in the longitudinal direction may be performed in two or more stages using three or more pairs of stretching rolls. By dividing into multiple stages, distortion during stretching can be reduced, making it easier to reduce the heating elongation rate.
　幅方向（ＴＤ）の延伸倍率の上限は好ましくは１５倍であり、より好ましくは１２倍であり、さらに好ましくは１０倍である。上記を超えると加熱伸び率が高くなり、また延伸時に破断しやすくなる。
　また、ＴＤの延伸温度の下限は好ましくは１５０℃であり、より好ましくは１５２℃であり、さらに好ましくは１５４℃、特に好ましくは１５６℃である。１５０℃以上であると充分に軟化した状態で延伸されるため、加熱伸び率を小さくしやすい。ＴＤ延伸温度の上限は好ましくは１６４℃であり、より好ましくは１６２℃であり、さらに好ましくは１６０℃である。加熱伸び率を低くするためには温度は高い方が好ましい。 The upper limit of the stretching ratio in the width direction (TD) is preferably 15 times, more preferably 12 times, and even more preferably 10 times. If it exceeds the above, the heating elongation rate will be high and it will be easy to break during stretching.
Further, the lower limit of the TD stretching temperature is preferably 150°C, more preferably 152°C, still more preferably 154°C, particularly preferably 156°C. When the temperature is 150° C. or higher, the stretching is done in a sufficiently softened state, so it is easy to reduce the heating elongation rate. The upper limit of the TD stretching temperature is preferably 164°C, more preferably 162°C, and still more preferably 160°C. In order to lower the heating elongation rate, higher temperatures are preferred.
　幅方向（ＴＤ）延伸後の熱固定の温度の下限は好ましくは１６８℃であり、より好ましくは１７０℃であり、さらに好ましくは１７３℃である。１６８℃以上であると加熱伸び率が高くなりにくく、加熱伸び率を低くするために長時間の処理を行う必要がない。 The lower limit of the heat setting temperature after stretching in the width direction (TD) is preferably 168°C, more preferably 170°C, and still more preferably 173°C. When the temperature is 168° C. or higher, the heating elongation rate is difficult to increase, and there is no need to perform a long treatment in order to lower the heating elongation rate.
　熱固定時には緩和（リラックス）させることが好ましい。リラックス率の下限は好ましくは２％であり、より好ましくは３％である。上記未満であると加熱伸び率が高くなることがある。 It is preferable to relax during heat fixation. The lower limit of the relaxation rate is preferably 2%, more preferably 3%. If it is less than the above, the heating elongation rate may become high.
　さらに、熱収縮率を低下させるために、上記の工程で製造されたフィルムを一旦ロール状に巻き取った後、オフラインでアニールさせることもできる。 Furthermore, in order to reduce the thermal shrinkage rate, the film produced in the above process can be wound up into a roll and then annealed off-line.
　本発明で用いる基材フィルムは、ハンドリング性（例えば、積層後の巻取り性）を付与するために、フィルムに粒子を含有させてフィルム表面に突起を形成させることが好ましい。フィルムに含有させる粒子としては、シリカ、カオリナイト、タルク、炭酸カルシウム、ゼオライト、アルミナ等の無機粒子、アクリル、ＰＭＭＡ、ナイロン、ポリスチレン、ポリエステル、ベンゾグアナミン・ホルマリン縮合物等の耐熱性高分子粒子が挙げられる。透明性の点から、フィルム中の粒子の含有量は少ないことが好ましく、例えば、１ｐｐｍ以上１０００ｐｐｍ以下であることが好ましい。また、粒子の好ましい平均粒子径は１．０～３．０μｍであり、より好ましくは１．０～２．７μｍである。ここでいう平均粒径の測定法は、走査電子顕微鏡で写真撮影し、イメージアナライザー装置を用いて水平方向のフェレ径を測定し、その平均値で表示したものである。さらに、透明性の点から使用する樹脂と屈折率の近い粒子を選択することが好ましい。また、フィルムには必要に応じて各種機能を付与するために、酸化防止剤、紫外線吸収剤、帯電防止剤、色素、滑剤、造核剤、粘着剤、防曇剤、難燃剤、アンチブロッキング剤、無機又は有機の充填剤等を含有させてもよい。 The base film used in the present invention preferably contains particles to form protrusions on the film surface in order to impart handling properties (for example, winding properties after lamination). Examples of particles to be included in the film include inorganic particles such as silica, kaolinite, talc, calcium carbonate, zeolite, and alumina, and heat-resistant polymer particles such as acrylic, PMMA, nylon, polystyrene, polyester, and benzoguanamine/formalin condensate. It will be done. From the viewpoint of transparency, the content of particles in the film is preferably small, for example, preferably 1 ppm or more and 1000 ppm or less. Further, the average particle diameter of the particles is preferably 1.0 to 3.0 μm, more preferably 1.0 to 2.7 μm. The method for measuring the average particle size here is to take a photograph with a scanning electron microscope, measure the Feret diameter in the horizontal direction using an image analyzer, and display the average value. Furthermore, from the viewpoint of transparency, it is preferable to select particles having a refractive index similar to that of the resin used. In addition, in order to add various functions to the film as needed, we also add antioxidants, ultraviolet absorbers, antistatic agents, pigments, lubricants, nucleating agents, adhesives, antifogging agents, flame retardants, and antiblocking agents. , an inorganic or organic filler, etc. may be included.
　本発明で用いられるポリプロピレン系樹脂以外でも、基材フィルムの機械特性、及び、前記ガスバリア性コート層上に積層されるインキ層や接着層との接着性向上、環境負荷低減等を目的に本発明の目的を損なわない範囲において別の樹脂を使用できる。例えば、ポリエチレン樹脂、前記と異なるポリプロピレン樹脂、プロピレンとエチレン及び／又は炭素数４以上のα－オレフィンとの共重合体であるランダムコポリマーや、各種エラストマー等が挙げられる。 In addition to the polypropylene resin used in the present invention, the present invention aims to improve the mechanical properties of the base film, improve the adhesion with the ink layer and adhesive layer laminated on the gas barrier coating layer, reduce environmental burden, etc. Other resins can be used as long as they do not impair the purpose. Examples include polyethylene resins, polypropylene resins different from those mentioned above, random copolymers that are copolymers of propylene and ethylene and/or α-olefins having 4 or more carbon atoms, and various elastomers.
　本発明において基材フィルムに用いることのできるポリエチレン系樹脂はエチレンを主成分とする樹脂であり、例えば、高圧法低密度ポリエチレン、直鎖状低密度ポリエチレン、中密度ポリエチレン及び高密度ポリエチレン等のいずれのエチレン単独重合体を使用することができる他に、プロピレン、ブテン－１、ペンテン－１、ヘキセン－１、３－メチルブテン－１、４－メチルペンテン－１、オクテン－１等のα－オレフィン、酢酸ビニル、（メタ）アクリル酸、（メタ）アクリル酸エステル等のモノマーとの結晶性、あるいは、低結晶性ないし非結晶性のランダムもしくはブロック共重合体、あるいはこれらの混合物等を用いることができる。
　ポリエチレン系樹脂は基材を構成するポリプロピレン系樹脂及びポリエチレン系樹脂の合計１００に対して、１質量％以上２５質量％以下含まれるのが好ましい。１質量％以上であるとヒートシール強度、耐ブロッキング性や防曇性が向上する。より好ましくは５質量％以上であり、さらに好ましくは８質量％以上である。２０質量％以下あると剛性を維持しやすい。より好ましくは１８質量％以下であり、さらに好ましくは１５質量％以下である。 The polyethylene resin that can be used for the base film in the present invention is a resin whose main component is ethylene, such as high-pressure low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, and high-density polyethylene. In addition to the ethylene homopolymers that can be used, α-olefins such as propylene, butene-1, pentene-1, hexene-1, 3-methylbutene-1, 4-methylpentene-1, octene-1, etc. Crystalline or low-crystalline to non-crystalline random or block copolymers with monomers such as vinyl acetate, (meth)acrylic acid, (meth)acrylic esters, or mixtures thereof can be used. .
It is preferable that the polyethylene resin is contained in an amount of 1% by mass or more and 25% by mass or less based on the total of 100% of the polypropylene resin and polyethylene resin constituting the base material. When the content is 1% by mass or more, heat seal strength, blocking resistance, and antifogging properties are improved. More preferably, it is 5% by mass or more, and still more preferably 8% by mass or more. When the content is 20% by mass or less, rigidity can be easily maintained. More preferably it is 18% by mass or less, and still more preferably 15% by mass or less.
　ポリエチレン系樹脂の融点については、耐熱性、透明性、力学特性、製膜性の観点から、好ましくは、１００℃以上１３５℃以下、より好ましくは、１０５℃以上１３０℃以下での範囲である。また、密度については、ＪＩＳ　Ｋ７１１２に準じて測定し、０．９０ｇ／ｃｍ３以上０．９４ｇ／ｃｍ３以下が好ましく、０．９１ｇ／ｃｍ３以上０．９４ｇ／ｃｍ３以下がより好ましい。
　ポリエチレン系樹脂のメルトフローレート（ＭＦＲ）（１９０℃、２．１６ｋｇｆ）は、好ましくは０．５ｇ／１０分以上、より好ましくは１ｇ／１０分以上、さらに好ましくは２ｇ／１０分以上であり、成形性をより安定化させる観点から、好ましくは２０ｇ／１０分以下、より好ましくは１５ｇ／１０分以下、さらに好ましくは１０ｇ／１０分以下である。 The melting point of the polyethylene resin is preferably in the range of 100°C or more and 135°C or less, more preferably 105°C or more and 130°C or less, from the viewpoint of heat resistance, transparency, mechanical properties, and film formability. Further, the density is measured according to JIS K7112, and is preferably 0.90 g/cm 3 or more and 0.94 g/cm 3 or less, more preferably 0.91 g/cm 3 or more and 0.94 g/cm 3 or less.
The melt flow rate (MFR) (190°C, 2.16 kgf) of the polyethylene resin is preferably 0.5 g/10 minutes or more, more preferably 1 g/10 minutes or more, even more preferably 2 g/10 minutes or more, From the viewpoint of further stabilizing moldability, it is preferably 20 g/10 minutes or less, more preferably 15 g/10 minutes or less, even more preferably 10 g/10 minutes or less.
　低環境負荷の観点から、本発明のポリエチレン系樹脂には、植物由来のポリエチレン系樹脂を使用することが特に好ましい。ＩＳＯ１６６２０に準拠して測定されるポリエチレン系樹脂のバイオベース度は、５０％以上１００％以下であることが好ましく、７０％以上１００％以下であることが好ましく、８０％以上１００％以下であることがさらに好ましい。 From the viewpoint of low environmental impact, it is particularly preferable to use a plant-derived polyethylene resin as the polyethylene resin of the present invention. The biobased degree of the polyethylene resin measured in accordance with ISO 16620 is preferably 50% or more and 100% or less, preferably 70% or more and 100% or less, and 80% or more and 100% or less. is even more preferable.
　本発明において、基材フィルムの厚みは各用途に合わせて任意に設定されるが、下限は２μｍ以上が好ましく、より好ましくは３μｍ以上、さらに好ましくは４μｍ以上である。一方、厚みの上限は３００μｍ以下が好ましく、より好ましくは２５０μｍ以下、さらに好ましくは２００μｍ以下、特に好ましくは１５０μｍ以下である。厚みが薄い場合には、ハンドリング性が不良になりやすい。一方、厚みが厚い場合にはコスト面で問題があるだけでなく、ロール状に巻き取って保存した場合に巻き癖による平面性不良が発生しやすくなる。 In the present invention, the thickness of the base film is arbitrarily set according to each use, but the lower limit is preferably 2 μm or more, more preferably 3 μm or more, and still more preferably 4 μm or more. On the other hand, the upper limit of the thickness is preferably 300 μm or less, more preferably 250 μm or less, even more preferably 200 μm or less, particularly preferably 150 μm or less. When the thickness is thin, handling properties tend to be poor. On the other hand, when the thickness is large, not only is there a problem in terms of cost, but also when the film is wound into a roll and stored, poor flatness due to curling tends to occur.
　本発明の基材フィルムのヘイズは内容物の視認性の観点より、透明性があることが好ましく、具体的には６％以下が好ましく、より好ましくは５％以下であり、さらに好ましくは４％以下である。ヘイズは、例えば、延伸温度、熱固定温度が高すぎる場合、冷却ロール（ＣＲ）温度が高く延伸原反シートの冷却速度が遅い場合、低分子量が多すぎる場合に悪くなる傾向があるので、これらを調節することにより、前記範囲内に制御することができる。 The haze of the base film of the present invention is preferably transparent from the viewpoint of visibility of the contents, specifically preferably 6% or less, more preferably 5% or less, and even more preferably 4%. It is as follows. Haze tends to worsen, for example, when the stretching temperature and heat setting temperature are too high, when the cooling roll (CR) temperature is high and the cooling rate of the stretched raw sheet is slow, and when the low molecular weight is too high. It can be controlled within the above range by adjusting .
　また本発明における基材フィルム層には、本発明の目的を損なわない限りにおいて、コロナ放電処理、グロー放電処理、火炎処理、表面粗面化処理が施されてもよく、また、公知のアンカーコート処理、印刷、装飾等が施されてもよい。アンカーコートには一般にポリウレタンやポリエステル等の接着性良好な樹脂を用いるのが好適であるが、本発明におけるバリア向上のためのアンカーコート層については後述する。 In addition, the base film layer in the present invention may be subjected to corona discharge treatment, glow discharge treatment, flame treatment, surface roughening treatment, as long as the object of the present invention is not impaired. It may be treated, printed, decorated, etc. It is generally preferable to use a resin with good adhesion such as polyurethane or polyester for the anchor coat, but the anchor coat layer for improving the barrier in the present invention will be described later.
　本発明の包装材料は、ガスバリア層を有する基材フィルムを少なくとも１枚は必要であるが、基材フィルムを２枚以上貼り合わせることで、包装材料としての強靭性やガスバリア性能の向上が期待できるためより好ましい。強靭性においては、一般的に突刺し強度が大きい特性を有するポリプロピレン系二軸延伸フィルムを２枚使用することで、例えば、包装材料として広く用いられているポリエステルフィルム及びポリアミドフィルムの異素材２枚使い構成と比較しても遜色のない包材設計が可能となる。また、ガスバリア性においては、２枚の基材フィルムを用いることで、中間に位置するフィルムが外環境の影響、例えば、温湿度や外的屈曲等の影響を受けにくくなり、より安定したガスバリア性能を発揮することができる。その意味で、基材フィルムを２枚用いる場合にはガスバリア性能を有する被覆層や無機薄膜層は、中間フィルムに積層されていることが特に好ましい。 The packaging material of the present invention requires at least one base film having a gas barrier layer, but by bonding two or more base films together, it is expected that the toughness and gas barrier performance of the packaging material will be improved. more preferable. In terms of toughness, by using two sheets of biaxially stretched polypropylene film, which generally has high puncture strength, for example, two sheets of different materials such as polyester film and polyamide film, which are widely used as packaging materials, can be used. It becomes possible to design a packaging material that is comparable to the configuration used. In addition, in terms of gas barrier properties, by using two base films, the film located in the middle is less susceptible to the effects of the external environment, such as temperature, humidity, and external bending, resulting in more stable gas barrier performance. can demonstrate. In this sense, when two base films are used, it is particularly preferable that the coating layer or inorganic thin film layer having gas barrier performance is laminated on the intermediate film.
［ガスバリア層］
　本発明では、前記基材フィルムのうち少なくとも１枚はガスバリア層を有する積層基材フィルムである必要がある。なお、ガスバリア層としては、後述する、有機物を主たる構成成分とする被覆層（Ａ）又は無機物を主たる構成成分とする無機薄膜層（Ｂ）のいずれかを積層することが好ましい。さらに、ガスバリア層のバリア性を補助する目的で、後述のアンカーコート（Ｃ）や保護層（Ｄ）を併用して積層することもできる。 [Gas barrier layer]
In the present invention, at least one of the base films needs to be a laminated base film having a gas barrier layer. As the gas barrier layer, it is preferable to laminate either a coating layer (A) containing an organic substance as a main constituent or an inorganic thin film layer (B) containing an inorganic substance as a main constituent, which will be described later. Furthermore, for the purpose of assisting the barrier properties of the gas barrier layer, an anchor coat (C) and a protective layer (D), which will be described later, can also be laminated together.
［被覆層（Ａ）］
　本発明においては、ガスバリア層として被覆層（Ａ）を有することができる。ただし、本発明では、被覆層（Ａ）を設けることで工程が増えることによるコストアップや、膜厚によってはリサイクルが困難になる等の、環境への負荷が生じることに留意して設計する必要がある。 [Coating layer (A)]
In the present invention, a coating layer (A) can be provided as a gas barrier layer. However, in the present invention, when designing, it is necessary to take into account that the provision of the coating layer (A) will increase the cost due to the increase in the number of steps, and that depending on the thickness of the film, there will be a burden on the environment, such as making it difficult to recycle. There is.
　被覆層（Ａ）の付着量は０．１０～０．７０（ｇ／ｍ２）とすることが好ましい。被覆層（Ａ）の付着量は、下限は好ましくは０．１５（ｇ／ｍ２）以上、より好ましくは０．２０（ｇ／ｍ２）以上、さらに好ましくは０．２５（ｇ／ｍ２）以上であり、上限は好ましくは０．６５（ｇ／ｍ２）以下、より好ましくは０．６０（ｇ／ｍ２）以下、さらに好ましくは０．５５（ｇ／ｍ２）以下である。被覆層（Ａ）の付着量が０．７０（ｇ／ｍ２）を超えると、ガスバリア性は向上するが、被覆層内部の凝集力が不充分となり、また被覆層の均一性も低下するため、コート外観にムラ（ヘイズ上昇、白化）や欠陥が生じたり、ガスバリア性・接着性を充分に発現できない場合がある。また、加工性という点では膜厚が厚いことでブロッキングが発生するおそれもある。さらには、フィルムのリサイクル性に悪影響を及ぼす懸念があることや、原料・溶媒等の使用量も増えるため環境負荷の側面が強くなる。一方、被覆層（Ａ）の付着量が０．１０（ｇ／ｍ２）未満であると、充分なガスバリア性及び層間密着性が得られないおそれがある。 The coating amount of the coating layer (A) is preferably 0.10 to 0.70 (g/m 2 ). The lower limit of the adhesion amount of the coating layer (A) is preferably 0.15 (g/m 2 ) or more, more preferably 0.20 (g/m 2 ) or more, and even more preferably 0.25 (g/m 2 ) . ) or more, and the upper limit is preferably 0.65 (g/m 2 ) or less, more preferably 0.60 (g/m 2 ) or less, even more preferably 0.55 (g/m 2 ) or less. If the amount of the coating layer (A) attached exceeds 0.70 (g/m 2 ), the gas barrier properties will improve, but the cohesive force inside the coating layer will be insufficient and the uniformity of the coating layer will also decrease. , unevenness (increased haze, whitening) or defects may occur in the coat appearance, and gas barrier properties and adhesion properties may not be sufficiently developed. In addition, in terms of processability, blocking may occur due to the thick film. Furthermore, there is a concern that it will have a negative impact on the recyclability of the film, and the amount of raw materials, solvents, etc. used will increase, increasing the environmental burden. On the other hand, if the amount of the coating layer (A) deposited is less than 0.10 (g/m 2 ), sufficient gas barrier properties and interlayer adhesion may not be obtained.
　本発明の積層フィルムの表面に形成する被覆層（Ａ）に用いる樹脂組成物としては、ポリビニルアルコール樹脂、ポリエステル樹脂、及びポリウレタン樹脂からなる群より選択されてなる樹脂を構成成分として含むことが好ましく、ポリビニルアルコール系重合体（樹脂）を含むことが望ましい。ポリビニルアルコール系重合体は、ビニルアルコール単位を主要構成成分とするものであり、水素結合構造による高い凝集性によるバリア性能の大幅な向上が期待できる。ポリビニルアルコール系重合体の重合度、鹸化度は、目的とするガスバリア性及びコーティング水溶液の粘度等から定められる。重合度については、水溶液粘度が高いことやゲル化しやすいことから、コーティングが困難となり、コーティングの作業性から２６００以下が好ましい。鹸化度については、９０％未満では高湿下での十分な酸素ガスバリア性が得られず、９９．７％を超えると水溶液の調整が困難で、ゲル化しやすく、工業生産には向かない。従って、鹸化度は９０～９９．７％が好ましく、さらに好ましくは９３～９９％である。また、本発明では加工性や生産性を損なわない範囲において、エチレンを共重合したポリビニルアルコール系重合体、シラノール変性したポリビニルアルコール系重合体等、各種共重合又は変性したポリビニルアルコール系重合体も使用できる。 The resin composition used for the coating layer (A) formed on the surface of the laminated film of the present invention preferably contains a resin selected from the group consisting of polyvinyl alcohol resin, polyester resin, and polyurethane resin as a constituent component. , a polyvinyl alcohol polymer (resin). Polyvinyl alcohol-based polymers have vinyl alcohol units as their main constituents, and can be expected to significantly improve barrier performance due to high cohesiveness due to hydrogen bond structures. The degree of polymerization and saponification of the polyvinyl alcohol polymer are determined based on the desired gas barrier properties and the viscosity of the aqueous coating solution. Regarding the degree of polymerization, coating is difficult due to the high viscosity of the aqueous solution and the tendency to gel, so a degree of polymerization of 2,600 or less is preferable from the viewpoint of workability of coating. Regarding the degree of saponification, if it is less than 90%, sufficient oxygen gas barrier properties under high humidity cannot be obtained, and if it exceeds 99.7%, it is difficult to prepare an aqueous solution and it is easy to gel, making it unsuitable for industrial production. Therefore, the degree of saponification is preferably 90 to 99.7%, more preferably 93 to 99%. In addition, in the present invention, various copolymerized or modified polyvinyl alcohol polymers, such as polyvinyl alcohol polymers copolymerized with ethylene and polyvinyl alcohol polymers modified with silanol, are also used within the range that does not impair processability or productivity. can.
　本発明の被覆層（Ａ）には無機層状化合物を含有してもよい。無機層状化合物が存在することで、気体に対する迷路効果が期待でき、ガスバリア性が向上する。また、無機層状化合物を添加することでガスバリア性の湿度依存性を抑制することができる。材料としては、スメクタイト、カオリン、雲母、ハイドロタルサイト、クロライト等の粘土鉱物（その合成品を含む）を挙げることができる。具体的には、モンモリロナイト、バイデライト、サポナイト、ヘクトライト、ソーコナイト、スチーブンサイト、カオリナイト、ナクライト、ディッカイト、ハロイサイト、加水ハロイサイト、テトラシリリックマイカ、ナトリウムテニオライト、白雲母、マーガライト、金雲母、タルク、アンチゴライト、クリソタイル、パイロフィライト、バーミキュライト、ザンソフィライト、緑泥石等を挙げることができる。さらに無機層状化合物として鱗片状シリカ等も使用できる。これらは単独で用いてもよく、２種以上を併用してもよい。これらのうちでも、特にスメクタイト（その合成品も含む）が水蒸気バリア性の向上効果が高いことから好ましい。 The coating layer (A) of the present invention may contain an inorganic layered compound. The presence of the inorganic layered compound can be expected to have a labyrinth effect against gas, improving gas barrier properties. Furthermore, by adding an inorganic layered compound, the humidity dependence of gas barrier properties can be suppressed. Examples of the material include clay minerals (including synthetic products thereof) such as smectite, kaolin, mica, hydrotalcite, and chlorite. Specifically, montmorillonite, beidellite, saponite, hectorite, sauconite, stevensite, kaolinite, nacrite, dickite, halloysite, hydrated halloysite, tetrasilylic mica, sodium taeniolite, muscovite, margarite, phlogopite, and talc. , antigorite, chrysotile, pyrophyllite, vermiculite, xanthophyllite, chlorite, and the like. Furthermore, scaly silica or the like can be used as an inorganic layered compound. These may be used alone or in combination of two or more. Among these, smectite (including synthetic products thereof) is particularly preferred because it has a high effect of improving water vapor barrier properties.
　また無機層状化合物としては、その中に酸化還元性を有する金属イオン、特に鉄イオンが存在するものが好ましい。さらに、このようなものの中でも、塗工適性やガスバリア性の点からはスメクタイトの１種であるモンモリロナイトが好ましい。モンモリロナイトとしては、従来からガスバリア剤に使用されている公知のものが使用できる。例えば、下記一般式：
　　（Ｘ，Ｙ）２～３Ｚ４Ｏ１０（ＯＨ）２・ｍＨ２Ｏ・（Ｗω）
（式中、Ｘは、Ａｌ、Ｆｅ（ＩＩＩ）、又はＣｒ（ＩＩＩ）を表す。Ｙは、Ｍｇ、Ｆｅ（ＩＩ）、Ｍｎ（ＩＩ）、Ｎｉ、Ｚｎ、又はＬｉを表す。Ｚは、Ｓｉ、又はＡｌを表す。Ｗは、Ｋ、Ｎａ、又はＣａを表す。Ｈ２Ｏは、層間水を表す。ｍ及びωは、正の実数を表す。）
　これらの中でも、式中のＷがＮａであるものが水性媒体中でへき開する点から好ましい。 Further, as the inorganic layered compound, one in which metal ions having redox properties, particularly iron ions, are present is preferable. Further, among these materials, montmorillonite, which is a type of smectite, is preferred from the viewpoint of coating suitability and gas barrier properties. As the montmorillonite, known ones that have been conventionally used in gas barrier agents can be used. For example, the following general formula:
(X, Y) 2~3 Z 4 O 10 (OH) 2・mH 2 O・(Wω)
(In the formula, X represents Al, Fe(III), or Cr(III). Y represents Mg, Fe(II), Mn(II), Ni, Zn, or Li. Z represents Si , or Al. W represents K, Na, or Ca. H 2 O represents interlayer water. m and ω represent positive real numbers.)
Among these, those in which W in the formula is Na are preferred because they cleave in an aqueous medium.
　無機層状化合物の大きさや形状は、特に制限されないが、粒径（長径）としては５μｍ以下が好ましく、より好ましくは４μｍ以下、さらに好ましくは３μｍ以下である。粒径が５μｍより大きいと、分散性に劣り、結果、被覆層（Ａ）の塗工性やコート外観が悪化する恐れがある。一方、そのアスペクト比としては５０～５０００、より好ましくは１００～４０００、さらに好ましくは２００～３０００である。 The size and shape of the inorganic layered compound are not particularly limited, but the particle diameter (length) is preferably 5 μm or less, more preferably 4 μm or less, and still more preferably 3 μm or less. If the particle size is larger than 5 μm, the dispersibility will be poor, and as a result, the coatability and coat appearance of the coating layer (A) may deteriorate. On the other hand, its aspect ratio is 50 to 5,000, more preferably 100 to 4,000, still more preferably 200 to 3,000.
　本発明の被覆層における樹脂組成物と無機層状化合物の配合比は７５／２５～３５／６５（質量％）が好ましく、より好ましくは７０／３０～４０／６０（質量％）、さらに好ましくは６５／３５～４５／５５（質量％）である。無機層状化合物の配合比が２５％より少ないと、バリア性能が不十分となるおそれがある。一方、６５％より多いと分散性が悪くなり塗工性が悪化することや、接着性が悪化するおそれがある。 The blending ratio of the resin composition and the inorganic layered compound in the coating layer of the present invention is preferably 75/25 to 35/65 (mass%), more preferably 70/30 to 40/60 (mass%), even more preferably 65 /35 to 45/55 (mass%). If the blending ratio of the inorganic layered compound is less than 25%, the barrier performance may be insufficient. On the other hand, if it is more than 65%, there is a risk that the dispersibility will deteriorate, resulting in poor coating properties and poor adhesion.
　本発明の被覆層（Ａ）には、膜の凝集力向上及び耐湿熱接着性を向上させる目的で、ガスバリア性や生産性を損なわない範囲で、各種の架橋剤を配合してもよい。架橋剤としては、例えば、ケイ素系架橋剤、オキサゾリン化合物、カルボジイミド化合物、エポキシ化合物、イソシアネート化合物等が例示できる。その中でも、ケイ素系架橋剤を配合することにより、水酸基を有する樹脂組成物や無機薄膜層と架橋反応させることができ、耐水接着性を向上させる観点から、ケイ素系架橋剤が特に好ましい。一般的に用いられるケイ素系架橋剤として、金属アルコキシドやシランカップリング剤が挙げられる。金属アルコキシドは、一般式、Ｍ（ＯＲ）ｎ（Ｍ：Ｓｉ、Ａｌの金属、Ｒ：ＣＨ３、Ｃ２Ｈ５等のアルキル基）で表せる化合物である。具体的にはテトラエトキシシラン〔Ｓｉ（ＯＣ２Ｈ５）４〕、トリイソプロポキシアルミニウム〔Ａｌ［ＯＣＨ（ＣＨ３）２］３〕等が例示できる。シランカップリング剤としては、３－グリシドキシプロピルトリメトキシシラン等のエポキシ基を有するもの、３－アミノプロピルトリメトキシシラン等のアミノ基を有するもの、３－メルカプトプロピルトリメトキシシラン等のメルカプト基を有するもの、３－イソシアネートプロピルトリエトキシシラン等のイソシアネート基を有するもの、トリス－（３－トリメトキシシリルプロピル）イソシアヌレート等を例示できる。その他に架橋剤として、オキサゾリン化合物、カルボジイミド化合物、エポキシ化合物等を併用してもよい。ただし、リサイクル性を重視する場合には架橋剤の配合量には配慮する必要がある。 The coating layer (A) of the present invention may contain various crosslinking agents for the purpose of improving the cohesive force and heat-and-moisture adhesive properties of the film, within a range that does not impair gas barrier properties or productivity. Examples of the crosslinking agent include silicon-based crosslinking agents, oxazoline compounds, carbodiimide compounds, epoxy compounds, and isocyanate compounds. Among them, silicon-based cross-linking agents are particularly preferred from the viewpoint of blending a silicon-based cross-linking agent to cause a cross-linking reaction with a resin composition having a hydroxyl group or an inorganic thin film layer, and improving water-resistant adhesion. Commonly used silicon-based crosslinking agents include metal alkoxides and silane coupling agents. The metal alkoxide is a compound represented by the general formula M(OR) n (M: metal such as Si or Al, R: alkyl group such as CH 3 or C 2 H 5 ). Specific examples include tetraethoxysilane [Si(OC 2 H 5 ) 4 ], triisopropoxyaluminum [Al[OCH(CH 3 ) 2 ] 3 ], and the like. Examples of silane coupling agents include those having an epoxy group such as 3-glycidoxypropyltrimethoxysilane, those having an amino group such as 3-aminopropyltrimethoxysilane, and mercapto groups such as 3-mercaptopropyltrimethoxysilane. Examples include those having an isocyanate group such as 3-isocyanatepropyltriethoxysilane, and tris-(3-trimethoxysilylpropyl)isocyanurate. In addition, as a crosslinking agent, an oxazoline compound, a carbodiimide compound, an epoxy compound, etc. may be used in combination. However, if recyclability is important, consideration must be given to the amount of crosslinking agent added.
　架橋剤を配合する場合、その配合量は被覆層中に０．０５～４．００質量％が好ましく、より好ましくは０．１０～３．５０質量％、さらに好ましくは０．１５～３．００質量％である。上記範囲とすることで膜の硬化が進み凝集力が向上し、結果として耐水接着性に優れた膜にすることができる。配合量が４．００質量％を超えると未架橋部分の存在量が増えることや、硬化が進みすぎて膜が硬くなることで、逆に接着性が低下するおそれがある。一方、配合量が０．０５質量％未満であると、十分な凝集力が得られないおそれがある。 When blending a crosslinking agent, the blending amount is preferably 0.05 to 4.00% by mass in the coating layer, more preferably 0.10 to 3.50% by mass, even more preferably 0.15 to 3.00% by mass. Mass%. By setting it within the above range, the film will be cured and the cohesive force will be improved, resulting in a film with excellent water-resistant adhesion. If the blending amount exceeds 4.00% by mass, there is a risk that the amount of uncrosslinked portions will increase, or that curing will progress too much and the film will become hard, resulting in a decrease in adhesion. On the other hand, if the blending amount is less than 0.05% by mass, sufficient cohesive force may not be obtained.
　本発明では、被覆層（Ａ）積層後のフィルムヘイズは、内容物の視認性の観点より、２０％以下あることが好ましく、より好ましくは１８％以下、さらに好ましくは１６％以下である。ヘイズが２０％より大きいと、透明性が大きく悪化することに加え、表面の凹凸にも影響を与える懸念があり、後の印刷工程等での外観不良につながるおそれがある。なお、ヘイズは被覆層（Ａ）の組成比や溶媒条件、膜厚等で調整ができる。ここでヘイズの評価はＪＩＳ　Ｋ７１３６に準拠し、濁度計（日本電色工業（株）製、ＮＤＨ２０００）を用いた。 In the present invention, the film haze after lamination of the coating layer (A) is preferably 20% or less, more preferably 18% or less, still more preferably 16% or less, from the viewpoint of visibility of the contents. If the haze is greater than 20%, in addition to greatly deteriorating transparency, there is a concern that surface irregularities may be affected, which may lead to poor appearance in subsequent printing steps and the like. Note that the haze can be adjusted by changing the composition ratio, solvent conditions, film thickness, etc. of the coating layer (A). Here, the haze was evaluated in accordance with JIS K7136 using a turbidity meter (manufactured by Nippon Denshoku Kogyo Co., Ltd., NDH2000).
　被覆層（Ａ）用樹脂組成物の塗工方式は、フィルム表面に塗工して層を形成させる方法であれば特に限定されるものではない。例えば、グラビアコーティング、リバースロールコーティング、ワイヤーバーコーティング、ダイコーティング等の通常のコーティング方法を採用することができる。 The coating method of the resin composition for the coating layer (A) is not particularly limited as long as it is a method of coating the film surface to form a layer. For example, conventional coating methods such as gravure coating, reverse roll coating, wire bar coating, and die coating can be employed.
　被覆層（Ａ）を形成する際には、被覆層（Ａ）用樹脂組成物を塗布した後、比較的低温で予備乾燥して、まず溶媒を揮発させ、その後高温で本乾燥させると、均一な膜が得られるため好ましい。予備乾燥の温度は８０～１１０℃が好ましく、より好ましくは８５～１０５℃、さらに好ましくは９０～１００℃である。予備乾燥温度が８０℃未満であると、被覆層に乾燥不足が生じるおそれがある。また、予備乾燥温度が１１０℃より大きいと、被覆層が濡れ広がる前に乾燥が進行してしまい、外観不良のおそれがある。 When forming the coating layer (A), after applying the resin composition for the coating layer (A), preliminary drying is performed at a relatively low temperature to first volatilize the solvent, and then main drying is performed at a high temperature. This method is preferable because it provides a film with a uniform structure. Pre-drying temperature is preferably 80 to 110°C, more preferably 85 to 105°C, still more preferably 90 to 100°C. If the pre-drying temperature is less than 80°C, there is a risk that the coating layer will be insufficiently dried. Furthermore, if the pre-drying temperature is higher than 110° C., drying will proceed before the coating layer is wetted and spread, which may result in poor appearance.
　一方、本乾燥温度は１１０～１４０℃が好ましく、より好ましくは１１５～１３５℃、さらに好ましくは１２０～１３０℃である。本乾燥温度が１１０℃未満であると、被覆層（Ａ）の造膜が進行せず凝集力及び接着性が低下し、結果としてバリア性にも悪影響を与えるおそれがある。１４０℃を超えると、フィルムに熱がかかりすぎてしまいフィルムが脆くなったり、熱収縮によるシワが大きくなるおそれがある。 On the other hand, the main drying temperature is preferably 110 to 140°C, more preferably 115 to 135°C, and even more preferably 120 to 130°C. If the main drying temperature is less than 110°C, the film formation of the coating layer (A) will not proceed, resulting in a decrease in cohesive force and adhesiveness, and as a result, there is a possibility that the barrier properties will also be adversely affected. If the temperature exceeds 140°C, too much heat is applied to the film, which may cause the film to become brittle or cause wrinkles due to heat shrinkage to increase.
　予備乾燥の好ましい乾燥時間は３．０～１０．０秒、より好ましくは３．５～９．５秒、さらに好ましくは４．０～９．０秒である。また、本乾燥の好ましい乾燥時間は３．０～１０．０秒、より好ましくは３．５～９．５秒、さらに好ましくは４．０～９．０秒である。ただし、乾燥の条件は、熱媒の方式や乾燥炉の吸排気状況によっても変わるため注意が必要である。また、乾燥とは別に、できるだけ低温領域、具体的には４０～６０℃の温度領域で１～４日間の追加の熱処理を加えることも、被覆層（Ａ）の造膜を進行させるうえで、さらに効果的である。 The preferred drying time for pre-drying is 3.0 to 10.0 seconds, more preferably 3.5 to 9.5 seconds, even more preferably 4.0 to 9.0 seconds. Further, the preferred drying time for the main drying is 3.0 to 10.0 seconds, more preferably 3.5 to 9.5 seconds, and still more preferably 4.0 to 9.0 seconds. However, care must be taken as the drying conditions vary depending on the heating medium type and the intake and exhaust conditions of the drying oven. In addition, in addition to drying, additional heat treatment for 1 to 4 days at as low a temperature as possible, specifically in the temperature range of 40 to 60°C, may be helpful in promoting the formation of the coating layer (A). Even more effective.
［無機薄膜層（Ｂ）］
　本発明では、ガスバリア層として前記基材フィルムの表面に無機薄膜層（Ｂ）を有することができる。無機薄膜層（Ｂ）は金属又は無機酸化物からなる薄膜である。無機薄膜層を形成する材料は、薄膜にできるものなら特に制限はないが、アルミニウム、酸化アルミニウム、酸化ケイ素、及び酸化ケイ素と酸化アルミニウムの複合酸化物からなる群より選択されてなる材料であることが好ましく、ガスバリア性の観点から、酸化ケイ素（シリカ）、酸化アルミニウム（アルミナ）、酸化ケイ素と酸化アルミニウムとの複合酸化物や混合物等の無機酸化物が好ましく挙げられる。特に、薄膜層の柔軟性と緻密性を両立できる点からは、酸化ケイ素と酸化アルミニウムとの複合酸化物が好ましい。この複合酸化物において、酸化ケイ素と酸化アルミニウムとの混合比は、金属分の質量比でＡｌが２０～７０質量％の範囲であることが好ましい。Ａｌ濃度が２０質量％未満であると、水蒸気バリア性が低くなる場合がある。一方、７０質量％を超えると、無機薄膜層が硬くなる傾向があり、印刷やラミネートといった二次加工の際に膜が破壊されてガスバリア性が低下する虞がある。なお、ここでいう酸化ケイ素とはＳｉＯやＳｉＯ２等の各種珪素酸化物又はそれらの混合物であり、酸化アルミニウムとは、ＡｌＯやＡｌ２Ｏ３等の各種アルミニウム酸化物又はそれらの混合物である。 [Inorganic thin film layer (B)]
In the present invention, an inorganic thin film layer (B) can be provided on the surface of the base film as a gas barrier layer. The inorganic thin film layer (B) is a thin film made of metal or inorganic oxide. The material forming the inorganic thin film layer is not particularly limited as long as it can be made into a thin film, but it must be a material selected from the group consisting of aluminum, aluminum oxide, silicon oxide, and a composite oxide of silicon oxide and aluminum oxide. is preferred, and from the viewpoint of gas barrier properties, inorganic oxides such as silicon oxide (silica), aluminum oxide (alumina), and composite oxides and mixtures of silicon oxide and aluminum oxide are preferably mentioned. In particular, a composite oxide of silicon oxide and aluminum oxide is preferred from the standpoint of achieving both flexibility and denseness of the thin film layer. In this composite oxide, the mixing ratio of silicon oxide and aluminum oxide is preferably such that Al is in the range of 20 to 70% by mass in terms of metal content. If the Al concentration is less than 20% by mass, the water vapor barrier property may be lowered. On the other hand, if it exceeds 70% by mass, the inorganic thin film layer tends to become hard, and there is a risk that the film will be destroyed during secondary processing such as printing or lamination, resulting in a decrease in gas barrier properties. Note that silicon oxide herein refers to various silicon oxides such as SiO and SiO 2 or mixtures thereof, and aluminum oxide refers to various aluminum oxides such as AlO and Al 2 O 3 or mixtures thereof.
　無機薄膜層（Ｂ）の膜厚は、通常１～１００ｎｍ、好ましくは５～５０ｎｍである。無機薄膜層（Ｂ）の膜厚が１ｎｍ未満であると、満足のいくガスバリア性が得られ難くなる場合があり、一方、１００ｎｍを超えて過度に厚くしても、それに相当するガスバリア性の向上効果は得られず、耐屈曲性や製造コストの点でかえって不利となる。 The thickness of the inorganic thin film layer (B) is usually 1 to 100 nm, preferably 5 to 50 nm. If the film thickness of the inorganic thin film layer (B) is less than 1 nm, it may be difficult to obtain satisfactory gas barrier properties.On the other hand, even if it is excessively thick by exceeding 100 nm, the corresponding improvement in gas barrier properties may not be achieved. No effect can be obtained, and it is rather disadvantageous in terms of bending resistance and manufacturing cost.
　無機薄膜層（Ｂ）を形成する方法としては、特に制限はなく、例えば、真空蒸着法、スパッタリング法、イオンプレーティング法等の物理蒸着法（ＰＶＤ法）、あるいは化学蒸着法（ＣＶＤ法）等、公知の蒸着法を適宜採用すればよい。以下、無機薄膜層（Ｂ）を形成する典型的な方法を、酸化ケイ素・酸化アルミニウム系薄膜を例に説明する。例えば、真空蒸着法を採用する場合は、蒸着原料としてＳｉＯ２とＡｌ２Ｏ３の混合物、あるいはＳｉＯ２とＡｌの混合物等が好ましく用いられる。これら蒸着原料としては通常粒子が用いられるが、その際、各粒子の大きさは蒸着時の圧力が変化しない程度の大きさであることが望ましく、好ましい粒子径は１ｍｍ～５ｍｍである。加熱には、抵抗加熱、高周波誘導加熱、電子ビーム加熱、レーザー加熱等の方式を採用することができる。また、反応ガスとして酸素、窒素、水素、アルゴン、炭酸ガス、水蒸気等を導入したり、オゾン添加、イオンアシスト等の手段を用いた反応性蒸着を採用することも可能である。さらに、被蒸着体（蒸着に供する積層フィルム）にバイアスを印加したり、被蒸着体を加熱もしくは冷却する等、成膜条件も任意に変更することができる。このような蒸着材料、反応ガス、被蒸着体のバイアス、加熱・冷却等は、スパッタリング法やＣＶＤ法を採用する場合にも同様に変更可能である。 There are no particular limitations on the method for forming the inorganic thin film layer (B), and examples include physical vapor deposition (PVD) such as vacuum evaporation, sputtering, and ion plating, or chemical vapor deposition (CVD). , any known vapor deposition method may be employed as appropriate. Hereinafter, a typical method for forming the inorganic thin film layer (B) will be explained using a silicon oxide/aluminum oxide thin film as an example. For example, when employing a vacuum evaporation method, a mixture of SiO 2 and Al 2 O 3 or a mixture of SiO 2 and Al is preferably used as the evaporation raw material. Particles are usually used as these vapor deposition raw materials, and in this case, the size of each particle is preferably such that the pressure during vapor deposition does not change, and the preferable particle size is 1 mm to 5 mm. For heating, methods such as resistance heating, high frequency induction heating, electron beam heating, laser heating, etc. can be adopted. It is also possible to introduce oxygen, nitrogen, hydrogen, argon, carbon dioxide, water vapor, etc. as a reactive gas, or to adopt reactive vapor deposition using means such as ozone addition or ion assist. Furthermore, the film forming conditions can also be changed arbitrarily, such as applying a bias to the object to be deposited (the laminated film to be subjected to vapor deposition), heating or cooling the object to be deposited. The evaporation material, reaction gas, bias of the evaporation target, heating/cooling, etc. can be similarly changed when sputtering or CVD is employed.
［アンカーコート層（Ｃ）］
　本発明においては、前述のガスバリア層を積層した際に、充分なガスバリア性や接着性を発現させるための補助層としてアンカーコート層（Ｃ）を有してもよい。アンカーコート層（Ｃ）を有することにより、ポリプロピレン樹脂からのオリゴマーやアンチブロッキング材の表出を抑制することができるため好ましい。さらに、アンカーコート層（Ｃ）の上に他の層を積層する際に、層間の密着力を高めることもできる。特に、無機薄膜層（Ｂ）の形成においては密着力だけでなく、表面を平滑化することで無機薄膜層（Ｂ）の形成が促進され、ガスバリア性が向上する効果も期待できる。加えて、アンカーコート層（Ｃ）そのものにもある一定程度のガスバリア性（ガスバリア補助性とする）を持つ材料を使用することで、前述のガスバリア層を積層した際のフィルムのガスバリア性能も大きく向上させることができるため好ましい。さらに、アンカーコート層（Ｃ）は、基材への熱水の侵入を防ぐため、結果としてボイルやレトルト後のフィルム白化も軽減することができるため好ましい。 [Anchor coat layer (C)]
In the present invention, when the gas barrier layers described above are laminated, an anchor coat layer (C) may be provided as an auxiliary layer for developing sufficient gas barrier properties and adhesive properties. Having the anchor coat layer (C) is preferable because it is possible to suppress exposure of oligomers and anti-blocking materials from the polypropylene resin. Furthermore, when laminating other layers on the anchor coat layer (C), it is also possible to increase the adhesion between the layers. In particular, in the formation of the inorganic thin film layer (B), the formation of the inorganic thin film layer (B) is promoted not only by adhesion but also by smoothing the surface, and the effect of improving gas barrier properties can be expected. In addition, by using a material that has a certain degree of gas barrier property (gas barrier auxiliary property) for the anchor coat layer (C) itself, the gas barrier performance of the film when the aforementioned gas barrier layer is laminated is also greatly improved. This is preferable because it allows Furthermore, the anchor coat layer (C) is preferable because it prevents hot water from entering the base material, and as a result, whitening of the film after boiling or retorting can be reduced.
　本発明においては、アンカーコート層（Ｃ）の付着量を０．１０～０．５０ｇ／ｍ２とすることが好ましい。これにより、塗工においてアンカーコート層（Ｃ）を均一に制御することができるため、結果としてコートムラや欠陥の少ない膜となるため好ましい。さらに、アンカーコート層（Ｃ）がオリゴマー表出抑制に寄与し、湿熱後のヘイズが安定化するため好ましい。アンカーコート層（Ｃ）の付着量は、好ましくは０．１５ｇ／ｍ２以上、より好ましくは０．２０ｇ／ｍ２以上、さらに好ましくは０．３５ｇ／ｍ２以上であり、好ましくは０．５０ｇ／ｍ２以下、より好ましくは０．４５ｇ／ｍ２以下、さらに好ましくは０．４０ｇ／ｍ２以下である。アンカーコート層（Ｃ）の付着量が０．５０ｇ／ｍ２を超えると、ガスバリア補助性は向上するが、アンカーコート層内部の凝集力が不充分となり、アンカーコート層の均一性も低下するため、コート外観にムラや欠陥が生じる。また、加工性という点では膜厚が厚いことでブロッキングが発生したり、製造コストがかかるおそれもある。さらには、フィルムのリサイクル性に悪影響を及ぼす懸念があることや、原料・溶媒等の使用量も増えるため環境負荷の側面が強くなる。一方、アンカーコート層（Ｃ）の膜厚が０．１０ｇ／ｍ２未満であると、充分なガスバリア補助性及び層間密着性が得られないおそれがある。 In the present invention, the amount of the anchor coat layer (C) deposited is preferably 0.10 to 0.50 g/m 2 . This is preferable because the anchor coat layer (C) can be uniformly controlled during coating, resulting in a film with less coating unevenness and defects. Further, the anchor coat layer (C) is preferable because it contributes to suppressing oligomer exposure and stabilizes haze after moist heat. The amount of adhesion of the anchor coat layer (C) is preferably 0.15 g/m 2 or more, more preferably 0.20 g/m 2 or more, even more preferably 0.35 g/m 2 or more, and preferably 0.50 g /m 2 or less, more preferably 0.45 g/m 2 or less, even more preferably 0.40 g/m 2 or less. If the adhesion amount of the anchor coat layer (C) exceeds 0.50 g/ m2 , the gas barrier support will improve, but the cohesive force inside the anchor coat layer will be insufficient and the uniformity of the anchor coat layer will also decrease. , causing unevenness and defects in the coat appearance. In addition, in terms of processability, a thick film may cause blocking or increase manufacturing costs. Furthermore, there are concerns that it will have a negative impact on the recyclability of the film, and the amount of raw materials, solvents, etc. used will increase, increasing the environmental burden. On the other hand, if the thickness of the anchor coat layer (C) is less than 0.10 g/m 2 , sufficient gas barrier support and interlayer adhesion may not be obtained.
　本発明のアンカーコート層（Ｃ）に用いる樹脂組成物としては、ウレタン系、ポリエステル系、アクリル系、チタン系、イソシアネート系、イミン系、ポリブタジエン系等の樹脂に、エポキシ系、イソシアネート系、メラミン系等の硬化剤を添加したものが挙げられる。さらにケイ素系架橋剤、オキサゾリン化合物、カルボジイミド化合物、エポキシ化合物等の架橋剤を含むことができる。 The resin composition used for the anchor coat layer (C) of the present invention includes urethane-based, polyester-based, acrylic-based, titanium-based, isocyanate-based, imine-based, and polybutadiene-based resins, as well as epoxy-based, isocyanate-based, and melamine-based resins. Examples include those to which a hardening agent such as the following is added. Furthermore, crosslinking agents such as silicon-based crosslinking agents, oxazoline compounds, carbodiimide compounds, and epoxy compounds can be included.
　特にウレタン樹脂をアンカーコート層（Ｃ）に含有させることで、ウレタン結合自体の高い凝集性によるバリア性能に加え、極性基が無機薄膜層（Ｂ）と相互作用するとともに、非晶部分の存在により柔軟性をも有するため、屈曲負荷がかかった際にもダメージを抑えることができるため好ましい。また、ポリエステル樹脂も同様の効果が期待できるため、好適である。本発明においては、ポリエステル＋イソシアネートを構成成分としたポリウレタンを含有するのが特に好ましく、さらに、接着性を向上させることができるという観点から、ケイ素系架橋剤を添加するとより好ましい。 In particular, by including urethane resin in the anchor coat layer (C), in addition to the barrier performance due to the high cohesiveness of the urethane bonds themselves, the polar groups interact with the inorganic thin film layer (B), and the presence of amorphous parts Since it also has flexibility, damage can be suppressed even when a bending load is applied, which is preferable. Polyester resin is also suitable since it can be expected to have similar effects. In the present invention, it is particularly preferable to contain polyurethane containing polyester and isocyanate as constituent components, and it is more preferable to add a silicon-based crosslinking agent from the viewpoint of improving adhesiveness.
　本発明のアンカーコート層（Ｃ）に用いるウレタン樹脂は、ガスバリア補助性の面から、芳香族又は芳香脂肪族ジイソシアネート成分を主な構成成分として含有するウレタン樹脂を用いることがより好ましい。その中でも、メタキシリレンジイソシアネート成分を含有することが特に好ましい。上記樹脂を用いることで、芳香環同士のスタッキング効果によりウレタン結合の凝集力を一層高めることができ、結果として良好なガスバリア補助性が得られる。 As the urethane resin used in the anchor coat layer (C) of the present invention, it is more preferable to use a urethane resin containing an aromatic or araliphatic diisocyanate component as a main component from the viewpoint of gas barrier assistance. Among these, it is particularly preferable to contain a metaxylylene diisocyanate component. By using the above resin, the cohesive force of the urethane bonds can be further increased due to the stacking effect of the aromatic rings, and as a result, good gas barrier support properties can be obtained.
　本発明においては、アンカーコート層（Ｃ）に用いるウレタン樹脂中の芳香族又は芳香脂肪族ジイソシアネートの割合を、ポリイソシアネート成分１００モル％中、５０モル％以上（５０～１００モル％）の範囲とすることが好ましい。芳香族又は芳香脂肪族ジイソシアネートの合計量の割合は、６０～１００モル％が好ましく、より好ましくは７０～１００モル％、さらに好ましくは８０～１００モル％である。芳香族又は芳香脂肪族ジイソシアネートの合計量の割合が５０モル％未満であると、良好なガスバリア補助性が得られない可能性がある。 In the present invention, the proportion of aromatic or araliphatic diisocyanate in the urethane resin used for the anchor coat layer (C) is within the range of 50 mol% or more (50 to 100 mol%) based on 100 mol% of the polyisocyanate component. It is preferable to do so. The proportion of the total amount of aromatic or araliphatic diisocyanate is preferably 60 to 100 mol%, more preferably 70 to 100 mol%, even more preferably 80 to 100 mol%. If the total amount of aromatic or araliphatic diisocyanate is less than 50 mol%, good gas barrier assistance may not be obtained.
　本発明のアンカーコート層（Ｃ）で用いるウレタン樹脂には、膜の凝集力向上及び耐湿熱接着性を向上させる目的で、各種の架橋剤を配合してもよい。架橋剤としては、例えば、ケイ素系架橋剤、オキサゾリン化合物、カルボジイミド化合物、エポキシ化合物等が例示できる。その中でも、ケイ素系架橋剤を配合することにより、特に無機薄膜層との耐水接着性を向上させることができるという観点から、ケイ素系架橋剤が特に好ましい。その他に架橋剤として、オキサゾリン化合物、カルボジイミド化合物、エポキシ化合物等を併用してもよい。 The urethane resin used in the anchor coat layer (C) of the present invention may contain various crosslinking agents for the purpose of improving the cohesive force and moist heat-resistant adhesiveness of the film. Examples of the crosslinking agent include silicon-based crosslinking agents, oxazoline compounds, carbodiimide compounds, and epoxy compounds. Among these, a silicon-based cross-linking agent is particularly preferred from the viewpoint that water-resistant adhesion to an inorganic thin film layer can be particularly improved by blending the silicon-based cross-linking agent. In addition, as a crosslinking agent, an oxazoline compound, a carbodiimide compound, an epoxy compound, etc. may be used in combination.
　ケイ素系架橋剤としては、無機物と有機物との架橋という観点から、シランカップリング剤が好ましい。シランカップリング剤としては、加水分解性アルコキシシラン化合物、例えば、ハロゲン含有アルコキシシラン（２－クロロエチルトリメトキシシラン、２－クロロエチルトリエトキシシラン、３－クロロプロピルトリメトキシシラン、３－クロロプロピルトリエトキシシラン等のクロロＣ２－４アルキルトリＣ１－４アルコキシシラン等）、エポキシ基を有するアルコキシシラン［２－グリシジルオキシエチルトリメトキシシラン、２－グリシジルオキシエチルトリエトキシシラン、３－グリシジルオキシプロピルトリメトキシシラン、３－グリシジルオキシプロピルトリエトキシシラン等のグリシジルオキシＣ２－４アルキルトリＣ１－４アルコキシシラン、３－グリシジルオキシプロピルメチルジメトキシシラン、３－グリシジルオキシプロピルメチルジエトキシシラン等のグリシジルオキシジＣ２－４アルキルジＣ１－４アルコキシシラン、２－（３，４－エポキシシクロヘキシル）エチルトリメトキシシラン、２－（３，４－エポキシシクロヘキシル）エチルトリエトキシシラン、３－（３，４－エポキシシクロヘキシル）プロピルトリメトキシシラン等の（エポキシシクロアルキル）Ｃ２－４アルキルトリＣ１－４アルコキシシラン等］、アミノ基を有するアルコキシシラン［２－アミノエチルトリメトキシシラン、３－アミノプロピルトリメトキシシラン、３－アミノプロピルトリエトキシシラン等のアミノＣ２－４アルキルトリＣ１－４アルコキシシラン、３－アミノプロピルメチルジメトキシシラン、３－アミノプロピルメチルジエトキシシラン等のアミノジＣ２－４アルキルジＣ１－４アルコシシラン、２－［Ｎ－（２－アミノエチル）アミノ］エチルトリメトキシシラン、３－［Ｎ－（２－アミノエチル）アミノ］プロピルトリメトキシシラン、３－［Ｎ－（２－アミノエチル）アミノ］プロピルトリエトキシシラン等の（２－アミノＣ２－４アルキル）アミノＣ２－４アルキルトリＣ１－４アルコキシシラン、３－［Ｎ－（２－アミノエチル）アミノ］プロピルメチルジメトキシシラン、３－［Ｎ－（２－アミノエチル）アミノ］プロピルメチルジエトキシシラン等の（アミノＣ２－４アルキル）アミノジＣ２－４アルキルジＣ１－４アルコキシシラン等］、メルカプト基を有するアルコキシシラン（２－メルカプトエチルトリメトキシシラン、３－メルカプトプロピルトリメトキシシラン、３－メルカプトプロピルトリエトキシシラン等のメルカプトＣ２－４アルキルトリＣ１－４アルコキシシラン、３－メルカプトプロピルメチルジメトキシシラン、３－メルカプトプロピルメチルジエトキシシラン等のメルカプトジＣ２－４アルキルジＣ１－４アルコキシシラン等）、ビニル基を有するアルコキシシラン（ビニルトリメトキシシラン、ビニルトリエトキシシラン等のビニルトリＣ１－４アルコキシシラン等）、エチレン性不飽和結合基を有するアルコキシシラン［２－（メタ）アクリロキシエチルトリメトキシシラン、２－（メタ）アクリロキシエチルトリエトキシシラン、３－（メタ）アクリロキシプロピルトリメトキシシラン、３－（メタ）アクリロキシプロピルトリエトキシシラン等の（メタ）アクリロキシＣ２－４アルキルトリＣ１－４アルコキシシラン、３－（メタ）アクリロキシプロピルメチルジメトキシシラン、３－（メタ）アクリロキシプロピルメチルジエトキシシラン等の（メタ）アクリロキシジＣ２－４アルキルジＣ１－４アルコキシシラン等）等が例示できる。これらのシランカップリング剤は、単独で又は二種以上組み合わせて使用できる。これらのシランカップリング剤のうち、アミノ基を有するシランカップリング剤が好ましい。 As the silicon-based crosslinking agent, a silane coupling agent is preferable from the viewpoint of crosslinking between an inorganic substance and an organic substance. As the silane coupling agent, hydrolyzable alkoxysilane compounds such as halogen-containing alkoxysilanes (2-chloroethyltrimethoxysilane, 2-chloroethyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, chloroC2-4 alkyl triC1-4 alkoxysilane such as ethoxysilane), alkoxysilane having an epoxy group [2-glycidyloxyethyltrimethoxysilane, 2-glycidyloxyethyltriethoxysilane, 3-glycidyloxypropyltrimethoxy silane, glycidyloxyC2-4alkyltriC1-4alkoxysilane such as 3-glycidyloxypropyltriethoxysilane, glycidyloxydiC2- such as 3-glycidyloxypropylmethyldimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, etc. 4-alkyl diC1-4 alkoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 3-(3,4-epoxycyclohexyl)propyltri (Epoxycycloalkyl)C2-4alkyltriC1-4alkoxysilane such as methoxysilane], alkoxysilane having an amino group [2-aminoethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, etc.] Amino C2-4 alkyl tri-C1-4 alkoxysilane such as ethoxysilane, amino di-C2-4 alkyl di-C1-4 alkoxysilane such as 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, 2-[N-( (2-aminoethyl)amino]ethyltrimethoxysilane, 3-[N-(2-aminoethyl)amino]propyltrimethoxysilane, 3-[N-(2-aminoethyl)amino]propyltriethoxysilane, etc. 2-AminoC2-4alkyl)aminoC2-4alkyltriC1-4alkoxysilane, 3-[N-(2-aminoethyl)amino]propylmethyldimethoxysilane, 3-[N-(2-aminoethyl)amino ] (amino diC2-4 alkyl diC2-4 alkyl diC1-4 alkoxysilane such as propylmethyldiethoxysilane), alkoxysilane having a mercapto group (2-mercaptoethyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane) , mercapto C2-4 alkyltriC1-4 alkoxysilane such as 3-mercaptopropyltriethoxysilane, mercapto diC2-4 alkyldiC1-4 alkoxysilane such as 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropylmethyldiethoxysilane, etc. etc.), alkoxysilanes having a vinyl group (vinyltriC1-4 alkoxysilanes such as vinyltrimethoxysilane and vinyltriethoxysilane), alkoxysilanes having an ethylenically unsaturated bond group [2-(meth)acryloxyethyltri (Meth)acryloxyC2-4alkyltriC1 such as methoxysilane, 2-(meth)acryloxyethyltriethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, etc. Examples include (meth)acryloxydiC2-4alkyldiC1-4alkoxysilanes such as -4 alkoxysilane, 3-(meth)acryloxypropylmethyldimethoxysilane, and 3-(meth)acryloxypropylmethyldiethoxysilane. . These silane coupling agents can be used alone or in combination of two or more. Among these silane coupling agents, silane coupling agents having an amino group are preferred.
　ケイ素系架橋剤はアンカーコート層（Ｃ）中に、０．０５～４．００質量％添加することが好ましく、より好ましくは０．１０～３．５０質量％、さらに好ましくは０．１５～３．００質量％である。ケイ素系架橋剤の添加により、膜の硬化が進み凝集力が向上、結果として耐水接着性に優れた膜になり、さらにオリゴマーの表出を防ぐ効果も期待できるため好ましい。添加量が４．００質量％を超えると、膜の硬化が進み凝集力が向上するが、一部未反応部分も生じ、層間の接着性は低下するおそれがある。一方、添加量が０．０５質量％未満であると、十分な凝集力が得られないおそれがある。 The silicon-based crosslinking agent is preferably added in an amount of 0.05 to 4.00% by mass, more preferably 0.10 to 3.50% by mass, even more preferably 0.15 to 3% by mass. .00% by mass. Addition of a silicon-based crosslinking agent is preferable because it promotes curing of the film and improves cohesive force, resulting in a film with excellent water-resistant adhesion, and can also be expected to have the effect of preventing the exposure of oligomers. If the amount added exceeds 4.00% by mass, the film will be cured and the cohesive force will be improved, but some unreacted portions may also be produced and the adhesion between the layers may be reduced. On the other hand, if the amount added is less than 0.05% by mass, sufficient cohesive force may not be obtained.
　本発明のアンカーコート層（Ｃ）に用いるポリエステル樹脂は、多価カルボン酸成分と、多価アルコール成分を重縮合することにより製造される。ポリエステル樹脂の分子量としては、コーティング材として十分な膜の靭性や塗工適性、溶媒溶解性が付与できるのであれば特に制限はないが数平均分子量で１０００～５００００、さらに好ましくは、１５００～３００００である。ポリエステル末端の官能基としても特に制限はなく、アルコール末端でも、カルボン酸末端でも、これらの両方を持っていても良い。但し、イソシアネート系硬化剤を併用する場合には、アルコール末端が主体であるポリエステルポリオールとする必要がある。 The polyester resin used for the anchor coat layer (C) of the present invention is produced by polycondensing a polyhydric carboxylic acid component and a polyhydric alcohol component. The molecular weight of the polyester resin is not particularly limited as long as it can provide sufficient film toughness, coating suitability, and solvent solubility as a coating material, but the number average molecular weight is 1,000 to 50,000, more preferably 1,500 to 30,000. be. There is no particular restriction on the functional group at the polyester end, and it may have an alcohol end, a carboxylic acid end, or both. However, when an isocyanate curing agent is used in combination, it is necessary to use a polyester polyol mainly containing alcohol terminals.
　本発明のアンカーコート層（Ｃ）に用いるポリエステル樹脂のＴｇは１０℃以上であることが好ましい。これ以上温度が低いと、樹脂がコーティング操作後に粘着性を持ち、ブロッキングを生じやすくなり、コーティング後の巻き取り操作がしにくくなるためである。Ｔｇが１０℃以下になるとブロッキング防止材の添加によっても巻き芯付近の圧力が高い状況下でもブロッキング防止対応が困難になるためである。Ｔｇのより好ましい温度は１５℃以上、さらに好ましくは２０℃以上である。 It is preferable that the Tg of the polyester resin used for the anchor coat layer (C) of the present invention is 10° C. or higher. This is because if the temperature is lower than this, the resin becomes sticky after the coating operation and tends to cause blocking, making it difficult to wind up the resin after coating. This is because if the Tg becomes 10° C. or lower, it becomes difficult to prevent blocking even when the pressure near the winding core is high even by adding an anti-blocking material. A more preferable temperature of Tg is 15°C or higher, more preferably 20°C or higher.
　本発明のアンカーコート層（Ｃ）に用いるポリエステル樹脂は、多価カルボン酸成分と、多価アルコール成分とを重縮合して用いる。本発明で用いるポリエステル樹脂の多価カルボン酸成分は、オルト配向芳香族ジカルボン酸又はその無水物の少なくとも１種を含むことに特徴を有する。オルト配向にすることで溶剤への溶解性が向上し、基材に対して均一にコーティングをすることが可能となる。均一にコートされた膜はバリア性能のばらつきが小さくなり、結果的にオリゴ白化抑制に寄与する。また、オルト配向にすることで柔軟性に優れた膜となり界面接着力が向上するため、湿熱処理による基材へのダメージを軽減でき、オリゴマーの抑制につながる。 The polyester resin used in the anchor coat layer (C) of the present invention is used by polycondensing a polyhydric carboxylic acid component and a polyhydric alcohol component. The polyhydric carboxylic acid component of the polyester resin used in the present invention is characterized in that it contains at least one ortho-oriented aromatic dicarboxylic acid or anhydride thereof. The ortho-orientation improves solubility in solvents and enables uniform coating on the substrate. A uniformly coated film reduces variations in barrier performance, which ultimately contributes to suppressing oligo whitening. In addition, the ortho-orientation creates a film with excellent flexibility and improves interfacial adhesion, which reduces damage to the base material due to moist heat treatment and leads to suppression of oligomer formation.
　カルボン酸がオルト位に置換された芳香族多価カルボン酸又はその無水物としては、オルトフタル酸又はその無水物、ナフタレン２，３－ジカルボン酸又はその無水物、ナフタレン１，２－ジカルボン酸又はその無水物、アントラキノン２，３－ジカルボン酸又はその無水物、及び２，３－アントラセンカルボン酸又はその無水物等が挙げられる。これらの化合物は、芳香環の任意の炭素原子に置換基を有していてもよい。該置換基としては、クロロ基、ブロモ基、メチル基、エチル基、ｉ－プロピル基、ヒドロキシル基、メトキシ基、エトキシ基、フェノキシ基、メチルチオ基、フェニルチオ基、シアノ基、ニトロ基、アミノ基、フタルイミド基、カルボキシル基、カルバモイル基、Ｎ－エチルカルバモイル基、フェニル基又はナフチル基等が挙げられる。また、これらのポリカルボン酸全成分１００モル％に対する含有率が７０～１００モル％であるポリエステルポリオールであると、バリア性の向上効果が高い上に、コーティング材として必須の溶媒溶解性に優れることから特に好ましい。 Examples of the aromatic polycarboxylic acid or its anhydride in which carboxylic acid is substituted at the ortho position include orthophthalic acid or its anhydride, naphthalene 2,3-dicarboxylic acid or its anhydride, and naphthalene 1,2-dicarboxylic acid or its anhydride. Examples include anhydride, anthraquinone 2,3-dicarboxylic acid or its anhydride, and 2,3-anthracenecarboxylic acid or its anhydride. These compounds may have a substituent on any carbon atom of the aromatic ring. Examples of the substituent include a chloro group, a bromo group, a methyl group, an ethyl group, an i-propyl group, a hydroxyl group, a methoxy group, an ethoxy group, a phenoxy group, a methylthio group, a phenylthio group, a cyano group, a nitro group, an amino group, Examples include phthalimide group, carboxyl group, carbamoyl group, N-ethylcarbamoyl group, phenyl group, and naphthyl group. In addition, polyester polyols with a content of 70 to 100 mol% based on 100 mol% of the total polycarboxylic acid components not only have a high barrier property improvement effect but also have excellent solvent solubility, which is essential as a coating material. Particularly preferred.
　本発明では発明の効果を損なわない範囲において、他の多価カルボン酸成分を共重合させてもよい。具体的には、脂肪族多価カルボン酸としては、コハク酸、アジピン酸、アゼライン酸、セバシン酸、ドデカンジカルボン酸等を、不飽和結合含有多価カルボン酸としては、無水マレイン酸、マレイン酸、フマル酸等を、脂環族多価カルボン酸としては、１，３－シクロペンタンジカルボン酸、１，４－シクロヘキサンジカルボン酸等を、芳香族多価カルボン酸としては、テレフタル酸、イソフタル酸、ピロメリット酸、トリメリット酸、１，４－ナフタレンジカルボン酸、２，５－ナフタレンジカルボン酸、２，６－ナフタレンジカルボン酸、ナフタル酸、ビフェニルジカルボン酸、ジフェン酸及びその無水物、１，２－ビス（フェノキシ）エタン－ｐ，ｐ’－ジカルボン酸及びこれらジカルボン酸の無水物或いはエステル形成性誘導体；ｐ－ヒドロキシ安息香酸、ｐ－（２－ヒドロキシエトキシ）安息香酸及びこれらのジヒドロキシカルボン酸のエステル形成性誘導体等の多塩基酸を単独で或いは二種以上の混合物で使用することができる。中でも、有機溶剤溶解性とガスバリア性の観点から、コハク酸、１，３－シクロペンタンジカルボン酸、イソフタル酸、２，６－ナフタレンジカルボン酸、１，８－ナフタル酸、ジフェン酸が好ましい。 In the present invention, other polyhydric carboxylic acid components may be copolymerized within a range that does not impair the effects of the invention. Specifically, aliphatic polycarboxylic acids include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, etc., and unsaturated bond-containing polycarboxylic acids include maleic anhydride, maleic acid, Fumaric acid, etc., alicyclic polycarboxylic acids such as 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, etc., aromatic polycarboxylic acids such as terephthalic acid, isophthalic acid, pyro- Mellitic acid, trimellitic acid, 1,4-naphthalene dicarboxylic acid, 2,5-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, diphenic acid and its anhydride, 1,2-bis (Phenoxy)ethane-p,p'-dicarboxylic acid and anhydride or ester-forming derivatives of these dicarboxylic acids; p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid and ester formation of these dihydroxycarboxylic acids Polybasic acids such as polybasic derivatives can be used alone or in a mixture of two or more. Among these, succinic acid, 1,3-cyclopentanedicarboxylic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,8-naphthalic acid, and diphenic acid are preferred from the viewpoint of organic solvent solubility and gas barrier properties.
　本発明のアンカーコート層（Ｃ）に用いるポリエステルの多価アルコール成分はガスバリア補填の性能を示すポリエステルを合成することができれば特に限定されないが、エチレングリコール、プロピレングリコール、ブチレングリコール、ネオペンチルグリコール、シクロヘキサンジメタノール、及び１，３－ビスヒドロキシエチルベンゼンからなる群から選ばれる少なくとも１種を含む多価アルコール成分を含有することが好ましい。中でも、酸素原子間の炭素原子数が少ないほど、分子鎖が過剰に柔軟にならずに、酸素透過しにくいと推定されることから、エチレングリコールを主成分として使用することが最も好ましい。 The polyhydric alcohol component of the polyester used in the anchor coat layer (C) of the present invention is not particularly limited as long as it can synthesize a polyester that exhibits gas barrier compensation performance, but examples include ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, and cyclohexane. It is preferable to contain a polyhydric alcohol component containing at least one selected from the group consisting of dimethanol and 1,3-bishydroxyethylbenzene. Among these, it is most preferable to use ethylene glycol as the main component because it is presumed that the smaller the number of carbon atoms between oxygen atoms, the less the molecular chain becomes excessively flexible and the more difficult oxygen permeation occurs.
　本発明では前述の多価アルコール成分を用いることが好ましいが、このほか、本発明の効果を損なわない範囲において、他の多価アルコール成分を共重合させてもよい。具体的には、ジオールとしては、１，５－ペンタンジオール、３－メチル－１，５－ペンタンジオール、１，６－ヘキサンジオール、メチルペンタンジオール、ジメチルブタンジオール、ブチルエチルプロパンジオール、ジエチレングリコール、トリエチレングリコール、テトラエチレングリコール、ジプロピレングリコール、トリプロピレングリコールが、三価以上のアルコールとしては、グリセロール、トリメチロールプロパン、トリメチロールエタン、トリス（２－ヒドロキシエチル）イソシアヌレート、１，２，４－ブタントリオール、ペンタエリスリトール、ジペンタエリスルトール等が挙げられる。特に、三価のアルコールの内、グリセロール、及びトリス（２－ヒドロキシエチル）イソシアヌレートを併用したポリエステルは、分岐構造に由来して架橋密度も適度に高いことにより有機溶媒溶解性が良好な上、バリア機能も優れており、特に好ましく用いられる。 In the present invention, it is preferable to use the polyhydric alcohol component described above, but other polyhydric alcohol components may be copolymerized as long as the effects of the present invention are not impaired. Specifically, the diols include 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol, dimethylbutanediol, butylethylpropanediol, diethylene glycol, and triethylene glycol. Ethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, trihydric or higher alcohols include glycerol, trimethylolpropane, trimethylolethane, tris(2-hydroxyethyl)isocyanurate, 1,2,4- Examples include butanetriol, pentaerythritol, dipentaerythritol, and the like. In particular, among trihydric alcohols, polyesters containing glycerol and tris(2-hydroxyethyl) isocyanurate have a moderately high crosslinking density due to their branched structure, and have good solubility in organic solvents. It also has an excellent barrier function and is particularly preferably used.
　本発明のポリエステルを得る反応に用いられる触媒としては、モノブチル酸化錫、ジブチル酸化錫等錫系触媒、テトラ－イソプロピル－チタネート、テトラ－ブチル－チタネート等のチタン系触媒、テトラ－ブチル－ジルコネート等のジルコニア系触媒等の酸触媒が挙げられる。エステル反応に対する活性が高い、テトラ－イソプロピル－チタネート、テトラ－ブチル－チタネート等の上記チタン系触媒と上記ジルコニア触媒を組み合わせて用いることが好ましい。前記触媒量は、使用する反応原料全質量に対して１～１０００ｐｐｍ用いられ、より好ましくは１０～１００ｐｐｍである。１ｐｐｍを下回ると触媒としての効果が得られにくく、１０００ｐｐｍを上回るとイソシアネート硬化剤を用いる場合にウレタン化反応を阻害する問題が生じる場合がある。 Catalysts used in the reaction to obtain the polyester of the present invention include tin-based catalysts such as monobutyl tin oxide and dibutyl tin oxide, titanium-based catalysts such as tetra-isopropyl-titanate and tetra-butyl-titanate, and tetra-butyl-zirconate. Examples include acid catalysts such as zirconia catalysts. It is preferable to use a combination of the titanium-based catalyst, such as tetra-isopropyl-titanate or tetra-butyl-titanate, which has high activity for ester reactions, and the zirconia catalyst. The amount of the catalyst used is 1 to 1000 ppm, more preferably 10 to 100 ppm, based on the total mass of the reaction materials used. If it is less than 1 ppm, it is difficult to obtain the effect as a catalyst, and if it exceeds 1000 ppm, there may be a problem of inhibiting the urethanization reaction when using an isocyanate curing agent.
　本発明では、アンカーコート層（Ｃ）を構成するコーティング剤の主剤としてポリエステル樹脂を用いる場合、硬化剤としてはイソシアネート系のものを用いて、ウレタン樹脂とすることが特に好ましい。この場合、コーティング層が架橋系になるため耐熱性や、耐摩耗性、剛性が向上する利点がある。従って、ボイルやレトルト包装にも使用しやすい。その一方で硬化剤を混合した後では液を再利用できない、塗工後に硬化（エージング）工程が必須になる問題点もある。利点として単純なオーバーコートワニスとして、例えば、塗工液の増粘の恐れがなく塗工製造の管理が容易、コーティング液を希釈再利用可能であり、加えて硬化工程（いわゆるエージング工程）が不要である点が例示できる。このとき、使用するポリエステルの末端は、ポリオールでもポリカルボン酸でも、この両者の混合物であっても問題なく用いることができる。その一方で、アンカーコート層（Ｃ）の樹脂が直鎖であるため耐熱性や、耐摩耗性が十分ではない場合や、ボイルやレトルト包装に使用しにくい問題が生じる場合がある。 In the present invention, when a polyester resin is used as the main ingredient of the coating agent constituting the anchor coat layer (C), it is particularly preferable to use an isocyanate-based curing agent to form a urethane resin. In this case, since the coating layer is crosslinked, there is an advantage that heat resistance, abrasion resistance, and rigidity are improved. Therefore, it is easy to use for boiling and retort packaging. On the other hand, there are also problems in that the liquid cannot be reused after the curing agent is mixed, and that a curing (aging) step is required after coating. As a simple overcoat varnish, its advantages include, for example, there is no risk of thickening of the coating solution, making it easy to manage coating production, the coating solution can be diluted and reused, and there is no need for a curing process (so-called aging process). An example can be given of this point. At this time, the terminal end of the polyester used may be a polyol, a polycarboxylic acid, or a mixture of the two without any problem. On the other hand, since the resin of the anchor coat layer (C) is linear, it may not have sufficient heat resistance or abrasion resistance, or it may be difficult to use for boiling or retort packaging.
　アンカーコート層（Ｃ）に硬化剤を用いる場合にはフィルムへのコーティングであるためフィルムの耐熱性の観点からイソシアネート硬化系が好ましく、この場合にはコーティング材の樹脂成分がポリエステルポリオールである必要がある。一方、エポキシ系化合物を硬化剤として用いる場合にはポリエステルポリカルボン酸である必要がある。これらの場合ではコーティング層が架橋系になるため耐熱性や、耐摩耗性、剛性が向上する利点がある。従って、ボイルやレトルト包装にも使用しやすい。その一方で硬化剤を混合した後では液を再利用できない、塗工後に硬化（エージング）工程が必須になる問題点もある。 When using a curing agent in the anchor coat layer (C), an isocyanate curing system is preferable from the viewpoint of the heat resistance of the film since the coating is on a film, and in this case, the resin component of the coating material needs to be a polyester polyol. be. On the other hand, when an epoxy compound is used as a curing agent, it needs to be a polyester polycarboxylic acid. In these cases, the coating layer is crosslinked, which has the advantage of improved heat resistance, abrasion resistance, and rigidity. Therefore, it is easy to use for boiling and retort packaging. On the other hand, there are also problems in that the liquid cannot be reused after the curing agent is mixed, and that a curing (aging) step is required after coating.
　本発明で用いられるポリイソシアネート化合物は、ポリエステルが水酸基を有する場合、少なくとも一部が反応し、ウレタン構造を作ることで樹脂成分として高極性化し、ポリマー鎖間を凝集させることでガスバリア機能を更に強化できる。また、コーティング材の樹脂が直鎖型の樹脂である場合に、３価以上のポリイソシアネートで架橋することで、耐熱性や、耐摩耗性を付与することができる。本発明で用いられるポリイソシアネート化合物としては、ジイソシアネート、３価以上のポリイソシアネート、低分子化合物、高分子化合物のいずれでもよいが、骨格の一部に芳香族環、又は脂肪族環を含有するとガスバリア向上機能の観点から好ましい。例えば、芳香族環を持つイソシアネートとしては、トルエンジイソシアネート、ジフェニルメタンジイソシアネート、キシリレンジイソシアネート、ナフタレンジイソシアネート、脂肪族環を持つイソシアネートとしては、水素化キシリレンジイソシアネート、水素化トルエンジイソシアネート、イソホロンジイソシアネート、ノルボルンジイソシアネート、あるいはこれらのイソシアネート化合物の３量体、及びこれらのイソシアネート化合物の過剰量と、例えば、エチレングリコール、プロピレングリコール、トリメチロールプロパン、グリセリン、ソルビトール、エチレンジアミン、モノエタノールアミン、ジエタノールアミン、トリエタノールアミン等の低分子活性水素化合物又は各種ポリエステルポリオール類、ポリエーテルポリオール類、ポリアミド類の高分子活性水素化合物等と反応させて得られる末端イソシアネート基含有化合物が挙げられる。 When the polyester has a hydroxyl group, at least a portion of the polyisocyanate compound used in the present invention reacts to form a urethane structure, making it highly polar as a resin component, and further strengthening the gas barrier function by coagulating between polymer chains. can. Moreover, when the resin of the coating material is a linear resin, heat resistance and abrasion resistance can be imparted by crosslinking with a trivalent or higher valent polyisocyanate. The polyisocyanate compound used in the present invention may be a diisocyanate, a trivalent or higher polyisocyanate, a low-molecular compound, or a high-molecular compound, but if it contains an aromatic ring or an aliphatic ring in a part of the skeleton, the gas barrier Preferable from the viewpoint of improved functionality. For example, isocyanates with an aromatic ring include toluene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, and naphthalene diisocyanate, and isocyanates with an aliphatic ring include hydrogenated xylylene diisocyanate, hydrogenated toluene diisocyanate, isophorone diisocyanate, and norbornene diisocyanate. , or trimers of these isocyanate compounds, and excess amounts of these isocyanate compounds, such as ethylene glycol, propylene glycol, trimethylolpropane, glycerin, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine, etc. Examples include terminal isocyanate group-containing compounds obtained by reacting with low-molecular active hydrogen compounds or high-molecular active hydrogen compounds such as various polyester polyols, polyether polyols, and polyamides.
　前記アンカーコート層（Ｃ）を形成するための方法としては、特に限定されるものではなく、例えば、コート法等の従来公知の方法を採用することができる。コート法の中でも好適な方法としては、オフラインコート法、インラインコート法を挙げることができる。例えば、基材フィルム層を製造する工程で行うインラインコート法の場合、コート時の乾燥や熱処理の条件は、コート厚みや装置の条件にもよるが、コート後直ちに直角方向の延伸工程に送入し延伸工程の予熱ゾーンあるいは延伸ゾーンで乾燥させることが好ましく、そのような場合には通常５０～２５０℃程度の温度とすることが好ましい。 The method for forming the anchor coat layer (C) is not particularly limited, and for example, a conventionally known method such as a coating method can be employed. Among the coating methods, preferable methods include an offline coating method and an inline coating method. For example, in the case of the inline coating method performed in the process of manufacturing the base film layer, the drying and heat treatment conditions during coating will depend on the coating thickness and equipment conditions, but immediately after coating, the film is sent to the orthogonal stretching process. It is preferable to dry the film in the preheating zone or stretching zone of the stretching process, and in such a case, the temperature is usually about 50 to 250°C.
　アンカーコート層（Ｃ）用の樹脂組成物の塗工方式は、フィルム表面に塗工して層を形成させる方法であれば特に限定されるものではない。例えば、グラビアコーティング、リバースロールコーティング、ワイヤーバーコーティング、ダイコーティング等の通常のコーティング方法を採用することができる。 The coating method of the resin composition for the anchor coat layer (C) is not particularly limited as long as it is a method of coating the film surface to form a layer. For example, conventional coating methods such as gravure coating, reverse roll coating, wire bar coating, and die coating can be employed.
　アンカーコート層（Ｃ）を形成する際には、アンカーコート層（Ｃ）用樹脂組成物を塗布した後、加熱乾燥することが好ましく、その際の乾燥温度は１００～１４５℃が好ましく、より好ましくは１１０～１４０℃、さらに好ましくは１１０～１３０℃である。乾燥温度が１００℃未満であると、アンカーコート層に乾燥不足が生じるおそれがある。一方、乾燥温度が１４５℃を超えると、フィルムに熱がかかりすぎてしまいフィルムが脆くなったり、収縮して加工性が悪くなったりする虞がある。特に、塗布直後に８０℃～１１０℃の比較的低温条件でまず溶媒を揮発させ、その後１２０℃以上で乾燥させると、均一な膜が得られるため、特に好ましい。また、乾燥とは別に、できるだけ低温領域で追加の熱処理を加えることも、アンカーコート層の造膜を進行させるうえで、さらに効果的である。 When forming the anchor coat layer (C), it is preferable to heat dry after applying the resin composition for the anchor coat layer (C), and the drying temperature at that time is preferably 100 to 145 ° C., more preferably is 110 to 140°C, more preferably 110 to 130°C. If the drying temperature is less than 100°C, the anchor coat layer may be insufficiently dried. On the other hand, if the drying temperature exceeds 145° C., too much heat is applied to the film, which may cause the film to become brittle or shrink, resulting in poor workability. In particular, it is particularly preferable to first volatilize the solvent immediately after coating at a relatively low temperature condition of 80° C. to 110° C., and then dry it at 120° C. or higher, since a uniform film can be obtained. Further, in addition to drying, it is also more effective to perform additional heat treatment in a low temperature range as much as possible in promoting film formation of the anchor coat layer.
［ガスバリア層上の保護層（Ｄ）］
　本発明においては、ガスバリア層の上に保護層（Ｄ）を有してもよい。特にガスバリア層が無機薄膜層（Ｂ）である場合、金属酸化物層からなる無機薄膜層（Ｂ）は完全に密な膜ではなく、微小な欠損部分が点在している。金属酸化物層上に後述する特定の保護層（Ｄ）用樹脂組成物を塗工して保護層（Ｄ）を形成することにより、金属酸化物層の欠損部分に保護層（Ｄ）用樹脂組成物中の樹脂が浸透し、結果としてガスバリア層のバリア性が安定するという効果が得られる。加えて、保護層（Ｄ）そのものにもガスバリア性を持つ材料を使用することで、積層フィルムのガスバリア性能も向上することになる。 [Protective layer (D) on gas barrier layer]
In the present invention, a protective layer (D) may be provided on the gas barrier layer. In particular, when the gas barrier layer is an inorganic thin film layer (B), the inorganic thin film layer (B) made of a metal oxide layer is not a completely dense film, but is dotted with minute defects. By coating a specific resin composition for a protective layer (D) described later on the metal oxide layer to form a protective layer (D), the resin for the protective layer (D) is applied to the defective part of the metal oxide layer. The resin in the composition permeates, resulting in the effect that the barrier properties of the gas barrier layer are stabilized. In addition, by using a material with gas barrier properties for the protective layer (D) itself, the gas barrier performance of the laminated film is also improved.
　本発明においては、保護層（Ｄ）の付着量を０．１０～０．４０（ｇ／ｍ２）とすることが好ましい。これにより、塗工において保護層（Ｄ）を均一に制御することができるため、結果としてコートムラや欠陥の少ない膜となるため好ましい。また保護層（Ｄ）自体の凝集力が向上し、ガスバリア層（特に無機薄膜層（Ｂ））－保護層（Ｄ）間の密着性も強固になるため好ましい。保護層の付着量は、好ましくは０．１３（ｇ／ｍ２）以上、より好ましくは０．１６（ｇ／ｍ２）以上、さらに好ましくは０．１９（ｇ／ｍ２）以上であり、好ましくは０．３７（ｇ／ｍ２）以下、より好ましくは０．３４（ｇ／ｍ２）以下、さらに好ましくは０．３１（ｇ／ｍ２）以下である。保護層（Ｄ）の付着量が０．４０（ｇ／ｍ２）を超えると、ガスバリア性は向上するが、保護層内部の凝集力が不充分となり、また保護層の均一性も低下するため、コート外観にムラや欠陥が生じたり、ガスバリア性・接着性を充分に発現できない場合がある。一方、保護層（Ｄ）の付着量が０．１０（ｇ／ｍ２）未満であると、充分なガスバリア性及び層間密着性が得られないおそれがある。 In the present invention, the amount of the protective layer (D) deposited is preferably 0.10 to 0.40 (g/m 2 ). This is preferable because the protective layer (D) can be uniformly controlled during coating, resulting in a film with less coating unevenness and defects. It is also preferable because the cohesive force of the protective layer (D) itself is improved and the adhesion between the gas barrier layer (especially the inorganic thin film layer (B)) and the protective layer (D) is also strengthened. The amount of adhesion of the protective layer is preferably 0.13 (g/m 2 ) or more, more preferably 0.16 (g/m 2 ) or more, even more preferably 0.19 (g/m 2 ) or more, It is preferably 0.37 (g/m 2 ) or less, more preferably 0.34 (g/m 2 ) or less, even more preferably 0.31 (g/m 2 ) or less. If the amount of the protective layer (D) attached exceeds 0.40 (g/m 2 ), the gas barrier properties will improve, but the cohesive force inside the protective layer will be insufficient and the uniformity of the protective layer will also decrease. , unevenness or defects may occur in the coat appearance, and gas barrier properties and adhesion properties may not be sufficiently developed. On the other hand, if the amount of the protective layer (D) deposited is less than 0.10 (g/m 2 ), sufficient gas barrier properties and interlayer adhesion may not be obtained.
　本発明のガスバリア層（特に無機薄膜層（Ｂ））の表面に形成する保護層（Ｄ）に用いる樹脂組成物としては、ポリビニルアルコール系、ウレタン系、ポリエステル系、アクリル系、チタン系、イソシアネート系、イミン系、ポリブタジエン系等の樹脂を用いることができ、さらにエポキシ系、イソシアネート系、メラミン系、シラノール系等の硬化剤を添加してもよい。 The resin composition used for the protective layer (D) formed on the surface of the gas barrier layer (especially the inorganic thin film layer (B)) of the present invention includes polyvinyl alcohol-based, urethane-based, polyester-based, acrylic-based, titanium-based, and isocyanate-based resin compositions. , imine-based, polybutadiene-based resins, etc. may be used, and furthermore, epoxy-based, isocyanate-based, melamine-based, silanol-based, and other curing agents may be added.
　保護層（Ｄ）用樹脂組成物の塗工方式は、フィルム表面に塗工して層を形成させる方法であれば特に限定されるものではない。例えば、グラビアコーティング、リバースロールコーティング、ワイヤーバーコーティング、ダイコーティング等の通常のコーティング方法を採用することができる。 The coating method of the resin composition for the protective layer (D) is not particularly limited as long as it is a method of coating the film surface to form a layer. For example, conventional coating methods such as gravure coating, reverse roll coating, wire bar coating, and die coating can be employed.
　保護層（Ｄ）を形成する際には、保護層（Ｄ）用樹脂組成物を塗布した後、加熱乾燥することが好ましく、その際の乾燥温度は１００～１６０℃が好ましく、より好ましくは１１０～１５０℃、さらに好ましくは１２０～１４０℃である。乾燥温度が１００℃未満であると、保護層（Ｄ）に乾燥不足が生じたり、保護層（Ｄ）の造膜が進行せず凝集力及び耐水接着性が低下し、結果としてバリア性や手切れ性が低下するおそれがある。一方、乾燥温度が１６０℃を超えると、フィルムに熱がかかりすぎてしまいフィルムが脆くなり突刺し強度が低下したり、収縮して加工性が悪くなったりする虞がある。また、乾燥とは別に、できるだけ低温領域で追加の熱処理を加えることも、保護層の造膜を進行させるうえで、さらに効果的である。 When forming the protective layer (D), it is preferable to apply the resin composition for the protective layer (D) and then heat dry it, and the drying temperature at that time is preferably 100 to 160°C, more preferably 110°C. ~150°C, more preferably 120~140°C. If the drying temperature is less than 100°C, the protective layer (D) may be insufficiently dried, or the film formation of the protective layer (D) may not proceed, resulting in a decrease in cohesive force and water-resistant adhesion, resulting in poor barrier properties and poor handling. There is a risk that cutting performance will decrease. On the other hand, if the drying temperature exceeds 160° C., too much heat is applied to the film, which may cause the film to become brittle, resulting in a decrease in puncture strength, or shrinkage, resulting in poor workability. Furthermore, in addition to drying, it is also more effective to perform additional heat treatment at a low temperature as much as possible in order to advance the formation of the protective layer.
［その他のフィルム］
　本発明では、包装材料に対する後述のモノマテリアル比率を満たす範囲において、ポリオレフィン系樹脂を構成成分とする基材フィルム以外のその他のフィルムを有してもよい。本発明で用いるその他のフィルムは、例えば、プラスチックを溶融押し出しして、必要に応じ、長手方向及び／又は幅方向に延伸、冷却、熱固定を施したフィルムであり、プラスチックとしては、ナイロン４・６、ナイロン６、ナイロン６・６、ナイロン１２等で代表されるポリアミド、ポリエチレンテレフタレート、ポリブチレンテレフタレート、ポリエチレン－２，６－ナフタレート等で代表されるポリエステルの他、ポリ塩化ビニル、ポリ塩化ビニリデン、ポリビニルアルコール、エチレンビニルアルコール、全芳香族ポリアミド、ポリアミドイミド、ポリイミド、ポリエーテルイミド、ポリスルホン、ポリスチレン、ポリ乳酸等を挙げることができる。 [Other films]
In the present invention, other films than the base film containing a polyolefin resin as a constituent may be included within a range that satisfies the below-mentioned monomaterial ratio to the packaging material. Other films used in the present invention are, for example, films made by melt-extruding plastic and stretching, cooling, and heat setting in the longitudinal direction and/or width direction as necessary. Examples of the plastic include nylon 4. 6. In addition to polyamides represented by nylon 6, nylon 6/6, and nylon 12, polyesters represented by polyethylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, etc., polyvinyl chloride, polyvinylidene chloride, Examples include polyvinyl alcohol, ethylene vinyl alcohol, wholly aromatic polyamide, polyamideimide, polyimide, polyetherimide, polysulfone, polystyrene, and polylactic acid.
　本発明におけるその他のフィルムは、機械強度、透明性等、所望の目的に応じて任意の膜厚のものを使用することができる。特に限定されないが、通常は５～２５０μｍであることが推奨され、包装材料として用いる場合は１０～６０μｍであることが望ましい。ただし、後述する包装材料のモノマテリアル比率に配慮する必要がある。 Other films in the present invention can have any thickness depending on desired objectives such as mechanical strength and transparency. Although not particularly limited, it is usually recommended that the thickness be 5 to 250 μm, and preferably 10 to 60 μm when used as a packaging material. However, it is necessary to consider the monomaterial ratio of packaging materials, which will be described later.
　また本発明におけるその他のフィルムは、１種又は２種以上のプラスチックフィルムの積層型フィルムであってもよい。積層型フィルムとする場合の積層体の種類、積層数、積層方法等は特に限定されず、目的に応じて公知の方法から任意に選択することができる。 Further, the other film in the present invention may be a laminated film of one or more types of plastic films. In the case of forming a laminate film, the type of laminate, the number of layers, the method of lamination, etc. are not particularly limited, and can be arbitrarily selected from known methods depending on the purpose.
［ヒートシール性樹脂フィルム］
　本発明で用いるヒートシール性樹脂フィルムは、ポリオレフィン系樹脂組成物としてプロピレン－αオレフィンランダム共重合体を含み、さらにエチレン－プロピレン共重合エラストマー、エチレン－ブテン共重合エラストマー、プロピレン－ブテン共重合エラストマーから選ばれる少なくとも１つの成分を含むことが好ましい。 [Heat-sealable resin film]
The heat-sealable resin film used in the present invention contains a propylene-α olefin random copolymer as a polyolefin resin composition, and is further made from an ethylene-propylene copolymer elastomer, an ethylene-butene copolymer elastomer, or a propylene-butene copolymer elastomer. Preferably, it contains at least one selected component.
（プロピレン－αオレフィンランダム共重合体）
　本発明において、プロピレン－αオレフィンランダム共重合体は、プロピレンとプロピレン以外の炭素原子数が２又は４～２０のα－オレフィンの少なくとも１種との共重合体を挙げることができる。かかる炭素原子数が２又は４～２０のα－オレフィンモノマーとしては、エチレン、ブテン－１、ペンテン－１、４－メチルペンテン－１、ヘキセン－１、オクテン－１等を用いることができる。特に限定されるものではないが、延伸性、低収縮性の面からエチレンを用いるのが好ましい。また、少なくとも１種類以上であればよく、必要に応じて２種類以上を混合して用いることができる。特に好適であるのはプロピレン－エチレンランダム共重合体である。 (Propylene-α-olefin random copolymer)
In the present invention, the propylene-α-olefin random copolymer includes a copolymer of propylene and at least one α-olefin having 2 or 4 to 20 carbon atoms other than propylene. As such α-olefin monomers having 2 or 4 to 20 carbon atoms, ethylene, 1-butene, 1-pentene, 4-methylpentene-1, hexene-1, octene-1, etc. can be used. Although not particularly limited, ethylene is preferably used from the viewpoint of stretchability and low shrinkage. Further, it is sufficient that at least one kind is used, and two or more kinds can be mixed and used as necessary. Particularly suitable is a propylene-ethylene random copolymer.
　プロピレン－αオレフィンランダム共重合体のメルトフローレート（ＭＦＲ）の下限は、好ましくは０．６ｇ／１０ｍｉｎであり、より好ましくは１．０ｇ／１０分であり、さらに好ましくは１．２ｇ／１０ｍｉｎである。ランダム共重合体のメルトフローレートの上限は好ましくは１２．０ｇ／１０ｍｉｎであり、より好ましくは９．０ｇ／１０ｍｉｎであり、さらに好ましくは８．０ｇ／１０ｍｉｎである。メルトフローレートがこの範囲外であると、フィルム厚みの均一性等が損なわれることがある。本範囲に該当する共重合体として、具体的には例えば、プロピレン－エチレンランダム共重合体（住友化学（株）製、住友ノーブレンＷＦ５７７ＰＧ、２３０℃、荷重２．１６ｋｇにおけるＭＦＲ３．２ｇ／１０ｍｉｎ、融点１４２℃）、プロピレン－エチレン－ブテンランダム共重合体（住友化学（株）製、住ノーブレンＦＬ８１１５Ａ、２３０℃、荷重２．１６ｋｇにおけるＭＦＲ７．０ｇ／１０ｍｉｎ、融点１４８℃）、プロピレン－エチレン－ブテンランダム共重合体（住友化学（株）製、住友ノーブレンＦＬ６７４５Ａ、２３０℃、荷重２．１６ｋｇにおけるＭＦＲ６．０ｇ／１０ｍｉｎ、融点１３０℃）等が挙げられる。特に好適であるのは主とするモノマーがプロピレンであり、一定量のエチレンを共重合させたプロピレン－エチレンランダム共重合体である。本発明ではランダム共重合体を構成するモノマー組成比の多い順に呼称し記載した。 The lower limit of the melt flow rate (MFR) of the propylene-α olefin random copolymer is preferably 0.6 g/10 min, more preferably 1.0 g/10 min, and even more preferably 1.2 g/10 min. be. The upper limit of the melt flow rate of the random copolymer is preferably 12.0 g/10 min, more preferably 9.0 g/10 min, and still more preferably 8.0 g/10 min. If the melt flow rate is outside this range, the uniformity of the film thickness may be impaired. Examples of copolymers falling within this range include propylene-ethylene random copolymer (manufactured by Sumitomo Chemical Co., Ltd., Sumitomo Noblen WF577PG, MFR 3.2 g/10 min at 230°C, load 2.16 kg, melting point 142°C), propylene-ethylene-butene random copolymer (manufactured by Sumitomo Chemical Co., Ltd., Suminoblen FL8115A, MFR 7.0g/10min at 230°C, load 2.16kg, melting point 148°C), propylene-ethylene-butene random copolymer Copolymers (manufactured by Sumitomo Chemical Co., Ltd., Sumitomo Noblen FL6745A, MFR 6.0 g/10 min at 230° C., load 2.16 kg, melting point 130° C.) can be mentioned. Particularly suitable is a propylene-ethylene random copolymer in which the main monomer is propylene and a certain amount of ethylene is copolymerized. In the present invention, the random copolymers are named and described in descending order of monomer composition ratio.
　プロピレン－αオレフィンランダム共重合体の融点の下限は特に限定されないが、好ましくは１２０℃、より好ましくは１２５℃である。上記未満では耐熱性が損なわれ、湿熱処理の際に袋の内面同士が融着を起こすことがある。プロピレン－αオレフィンランダム共重合体の融点の上限は特に限定されないが、好ましくは１５５℃、より好ましくは１５０℃である。上記を超えるとヒートシールに必要な温度が高くなってしまうことがある。 The lower limit of the melting point of the propylene-α olefin random copolymer is not particularly limited, but is preferably 120°C, more preferably 125°C. If it is less than the above, heat resistance will be impaired and the inner surfaces of the bag may fuse together during moist heat treatment. The upper limit of the melting point of the propylene-α-olefin random copolymer is not particularly limited, but is preferably 155°C, more preferably 150°C. If the temperature exceeds the above, the temperature required for heat sealing may become high.
（共重合エラストマー）
　本発明で用いるヒートシール性樹脂フィルムにおけるポリオレフィン系樹脂組成物においては、包装袋の耐落下破袋性を高める目的で、ポリオレフィンを主体とする熱可塑性の共重合エラストマーを添加することができる。本発明における共重合エラストマーは、常温付近でゴム状弾性を示すオレフィン系熱可塑性共重合エラストマー、及びエラストマーの中でも比較的高いショア硬度や良好な透明性を示すオレフィン系熱可塑性の共重合エラストマーの少なくとも２種類以上の共重合エラストマーを併用するのがよい。これらを併用することにより、引裂きやすさと泣別れ、及び製袋性を付与しても、透明性、シール性及び耐破袋性も容易に得られやすいため好ましい。 (Copolymerized elastomer)
In the polyolefin resin composition of the heat-sealable resin film used in the present invention, a thermoplastic copolymer elastomer mainly composed of polyolefin can be added for the purpose of increasing the drop-breakage resistance of the packaging bag. The copolymerized elastomer in the present invention is at least an olefinic thermoplastic copolymerized elastomer that exhibits rubber-like elasticity at around room temperature, and an olefinic thermoplastic copolymerized elastomer that exhibits relatively high Shore hardness and good transparency among elastomers. It is preferable to use two or more types of copolymerized elastomers together. By using these in combination, transparency, sealability, and bag breakage resistance can be easily obtained even if tearability, tearability, and bag-making properties are imparted, which is preferable.
　常温付近でゴム状弾性を示すオレフィン系熱可塑性共重合エラストマーとして、エチレンとブテンを共重合させて得られる非晶性又は低結晶性のエラストマーであるエチレン－ブテン共重合エラストマーがある。エラストマーの中でも比較的高いショア硬度や良好な透明性を示すオレフィン系熱可塑性共重合エラストマーとして、エチレンとブテンを共重合させて得られる結晶性のエラストマーであるプロピレン－ブテン共重合エラストマーがある。 As an olefin-based thermoplastic copolymer elastomer that exhibits rubber-like elasticity at around room temperature, there is an ethylene-butene copolymer elastomer, which is an amorphous or low-crystalline elastomer obtained by copolymerizing ethylene and butene. Among elastomers, a propylene-butene copolymer elastomer, which is a crystalline elastomer obtained by copolymerizing ethylene and butene, is an olefin-based thermoplastic copolymer elastomer that exhibits relatively high Shore hardness and good transparency.
　エチレン－ブテン共重合エラストマー、及びエチレン－プロピレン共重合エラストマーの２３０℃、荷重２．１６ｋｇにおけるメルトフローレート（ＭＦＲ）が０．２～５．０ｇ／１０ｍｉｎ（又は、１９０℃、荷重２．１６ｋｇにおけるメルトフローレート（ＭＦＲ）が０．２～５．０ｇ／１０ｍｉｎ、）、密度が８２０～９３０ｋｇ／ｍ３、ＧＰＣ法により求めた分子量分布（Ｍｗ／Ｍｎ）が１．３～６．０であるものを用いるのが望ましい形態である。荷重２．１６ｋｇにおけるメルトフローレイト（ＭＦＲ）が０．２ｇ／１０ｍｉｎを下回ると、均一な混練が不十分となり、フィッシュアイが発生しやすくなり、また５．０ｇ／ｍｉｎを超えると、耐破袋性の観点から好ましくない。 The melt flow rate (MFR) of ethylene-butene copolymer elastomer and ethylene-propylene copolymer elastomer at 230 °C and a load of 2.16 kg is 0.2 to 5.0 g/10 min (or at 190 °C and a load of 2.16 kg). Melt flow rate (MFR) is 0.2 to 5.0 g/10 min), density is 820 to 930 kg/m 3 , and molecular weight distribution (Mw/Mn) determined by GPC method is 1.3 to 6.0. It is preferable to use something. When the melt flow rate (MFR) at a load of 2.16 kg is less than 0.2 g/10 min, uniform kneading becomes insufficient and fish eyes are likely to occur, and when it exceeds 5.0 g/min, tear-resistant bags Undesirable from a sexual perspective.
　エチレン－ブテン共重合エラストマー、及びプロピレン－ブテン共重合エラストマーの本発明におけるエチレン－ブテン共重合エラストマーの極限粘度［η］は、ヒートシール強度保持とインパクト強度保持、落袋強度の観点からの点で１．０～５．０が好ましく、好適には１．２～３．０である。極限粘度［η］が１．０を下回ると、均一な混練が不十分となり、フィッシュアイが発生しやすくなり、また５．０を超えると耐破袋性及び、ヒートシール強度の観点から好ましくない。 The intrinsic viscosity [η] of the ethylene-butene copolymer elastomer and propylene-butene copolymer elastomer in the present invention is determined from the viewpoints of heat seal strength retention, impact strength retention, and drop bag strength. It is preferably 1.0 to 5.0, preferably 1.2 to 3.0. When the intrinsic viscosity [η] is less than 1.0, uniform kneading becomes insufficient and fish eyes are likely to occur, and when it exceeds 5.0, it is unfavorable from the viewpoint of bag tear resistance and heat seal strength. .
　具体的には、密度８８５ｋｇ／ｍ３、ＭＦＲ（２３０℃、２．１６ｋｇ）１．４ｇ／１０ｍｉｎのエチレン－ブテン共重合エラストマー（三井化学（株）製、タフマーＡ１０８５Ｓ）、ＭＦＲ（１９０℃、２．１６ｋｇ）３．６ｇ／１０ｍｉｎのエチレン－ブテン共重合エラストマー（三井化学（株）製、タフマーＡ－４０７０Ｓ）、密度９００ｋｇ／ｍ３、ＭＦＲ（１９０℃、２．１６ｋｇ）３ｇ／１０ｍｉｎのプロピレン－ブテン共重合エラストマー（三井化学（株）製、タフマーＸＭ７０７０）が例示できる。 Specifically, an ethylene-butene copolymer elastomer (manufactured by Mitsui Chemicals, Inc., Tafmer A1085S) with a density of 885 kg/m 3 and an MFR (230° C., 2.16 kg) of 1.4 g/10 min; .16kg) 3.6g/10min ethylene-butene copolymer elastomer (manufactured by Mitsui Chemicals, Inc., Tafmer A-4070S), density 900kg/m 3 , MFR (190°C, 2.16kg) 3g/10min propylene. An example is a butene copolymer elastomer (manufactured by Mitsui Chemicals, Inc., Tafmer XM7070).
　本発明のヒートシール樹脂フィルムにおけるポリオレフィン系樹脂組成物において、プロピレン－αオレフィンランダム共重合体１００質量部に対して、エチレン－ブテン共重合エラストマーを２～９質量部、プロピレン－ブテン共重合エラストマーを２～９質量部含有することが好ましい。
　プロピレン－αオレフィンランダム共重合体１００質量部に対して、エチレン－ブテン共重合エラストマーを２質量部以上、プロピレン－ブテン共重合エラストマーを２質量部以上含有することにより引裂きやすさを付与した時に、シール性、製袋性、耐破袋性が得られやすく、エチレン－ブテン共重合エラストマーを９質量部以下、プロピレン－ブテン共重合エラストマーを９質量部以下含有することにより、透明性、耐ブロッキング性、耐破袋性が良好となりやすいため好ましい。 In the polyolefin resin composition of the heat-sealable resin film of the present invention, 2 to 9 parts by mass of the ethylene-butene copolymer elastomer and the propylene-butene copolymer elastomer are added to 100 parts by mass of the propylene-α olefin random copolymer. It is preferable to contain 2 to 9 parts by mass.
When imparting tearability by containing 2 parts by mass or more of an ethylene-butene copolymer elastomer and 2 parts by mass or more of a propylene-butene copolymer elastomer to 100 parts by mass of the propylene-α olefin random copolymer, It is easy to obtain sealing properties, bag making properties, and bag tear resistance, and by containing 9 parts by mass or less of ethylene-butene copolymer elastomer and 9 parts by mass or less of propylene-butene copolymer elastomer, transparency and blocking resistance are achieved. is preferable because it tends to have good bag breakage resistance.
　またポリオレフィン系樹脂組成物において、プロピレン－αオレフィンランダム共重合体１００質量部に対して、エチレン－ブテン共重合エラストマーを４～９質量部、プロピレン－ブテン共重合エラストマーを４～９質量部含有することがより好ましい。さらにまたポリオレフィン系樹脂組成物において、プロピレン－αオレフィンランダム共重合体１００質量部に対して、エチレン－ブテン共重合エラストマーを５～９質量部、プロピレン－ブテン共重合エラストマーを５～９質量部含有することがさらに好ましい。さらにまたポリオレフィン系樹脂組成物において、プロピレン－αオレフィンランダム共重合体１００質量部に対して、エチレン－ブテン共重合エラストマーを６～９質量部、プロピレン－ブテン共重合エラストマーを６～９質量部含有することがさらに好ましい。 Further, in the polyolefin resin composition, 4 to 9 parts by mass of an ethylene-butene copolymer elastomer and 4 to 9 parts by mass of a propylene-butene copolymer elastomer are contained per 100 parts by mass of the propylene-α olefin random copolymer. It is more preferable. Furthermore, the polyolefin resin composition contains 5 to 9 parts by mass of an ethylene-butene copolymer elastomer and 5 to 9 parts by mass of a propylene-butene copolymer elastomer per 100 parts by mass of the propylene-α olefin random copolymer. It is more preferable to do so. Furthermore, the polyolefin resin composition contains 6 to 9 parts by mass of an ethylene-butene copolymer elastomer and 6 to 9 parts by mass of a propylene-butene copolymer elastomer per 100 parts by mass of the propylene-α olefin random copolymer. It is more preferable to do so.
（添加剤）
　本発明のヒートシール性樹脂フィルムにおけるポリオレフィン系樹脂組成物は、アンチブロッキング剤を含んでよい。アンチブロッキング剤は１種類でもよいが、２種類以上の粒径や形状が異なる無機粒子を配合した方が、フィルム表面の凹凸においても、複雑な突起が形成され、より高度なブロッキング防止効果を得ることができる。 (Additive)
The polyolefin resin composition in the heat-sealable resin film of the present invention may contain an anti-blocking agent. One type of anti-blocking agent may be used, but it is better to combine two or more types of inorganic particles with different particle sizes and shapes to form complex protrusions even on the unevenness of the film surface and obtain a more advanced anti-blocking effect. be able to.
　添加するアンチブロッキング剤は特に限定されるものではないが、球状シリカ、不定形シリカ、ゼオライト、タルク、マイカ、アルミナ、ハイドロタルサイト、ホウ酸アルミニウム等の無機粒子や、ポリメチルメタクリレート、超高分子量ポリエチレン等の有機粒子を添加することができる。 The anti-blocking agent to be added is not particularly limited, but includes inorganic particles such as spherical silica, amorphous silica, zeolite, talc, mica, alumina, hydrotalcite, and aluminum borate, polymethyl methacrylate, and ultra-high molecular weight. Organic particles such as polyethylene can be added.
　ヒートシール性樹脂フィルムが、２層又は３層以上の多層構成の場合は、全層に上記添加剤を添加してもよく、二軸配向フィルムをラミネートする側の層の表面に凹凸があると、ラミネート加工の外観不良になることがあるので、フィルム同士をヒートシールする側の層のみに添加することが好ましい。 When the heat-sealable resin film has a multilayer structure of two or three layers or more, the above additives may be added to all layers, and if the surface of the layer on which the biaxially oriented film is laminated has unevenness, Since this may result in poor appearance during lamination, it is preferable to add it only to the layer on the side where the films are heat-sealed.
　二軸配向フィルムをラミネートする側の層をラミネート層、その表面をラミネート面と呼び、一方のフィルム同士をヒートシールする側の層をヒートシール層、その表面をヒートシール面と呼ぶ。 The layer on the side where biaxially oriented films are laminated is called the laminate layer, and its surface is called the laminate surface, and the layer on the side where one film is heat-sealed is called the heat-seal layer, and its surface is called the heat-seal surface.
　添加するアンチブロッキング剤は添加する層のポリオレフィン系樹脂組成物に対して、３０００ｐｐｍ以下であることが好ましく、２５００ｐｐｍ以下がより好ましい。３０００ｐｐｍ以下とすることにより、アンチブロッキング剤の脱落を低減することができる。 The amount of the anti-blocking agent added is preferably 3000 ppm or less, more preferably 2500 ppm or less, based on the polyolefin resin composition of the layer to which it is added. By setting the amount to 3000 ppm or less, it is possible to reduce shedding of the anti-blocking agent.
　本発明のヒートシール性樹脂フィルムにおけるポリオレフィン系樹脂組成物は、有機系潤滑剤を添加しても良い。積層フィルムの滑性やブロッキング防止効果が向上し、フィルムの取り扱い性がよくなる。その理由として、有機系潤滑剤がブリードアウトし、フィルム表面に存在することで、滑剤効果や離型効果が発現したものと考える。 An organic lubricant may be added to the polyolefin resin composition in the heat-sealable resin film of the present invention. The lubricity and anti-blocking effect of the laminated film are improved, making the film easier to handle. The reason for this is thought to be that the organic lubricant bleeds out and is present on the film surface, resulting in a lubricant effect and mold release effect.
　有機系潤滑剤は常温以上の融点を持つものを添加することが好ましい。有機系潤滑剤は、脂肪酸アミド、脂肪酸エステルが挙げられる。具体的には、オレイン酸アミド、エルカ酸アミド、ベヘニン酸アミド、エチレンビスオレイン酸アミド、ヘキサメチレンビスオレイン酸アミド、エチレンビスオレイン酸アミド等である。これらは単独で用いても構わないが、２種類以上を併用することで過酷な環境下においても滑性やブロッキング防止効果を維持することができるので好ましい。 It is preferable to add an organic lubricant that has a melting point above room temperature. Examples of organic lubricants include fatty acid amides and fatty acid esters. Specifically, they include oleic acid amide, erucic acid amide, behenic acid amide, ethylene bis oleic acid amide, hexamethylene bis oleic acid amide, ethylene bis oleic acid amide, and the like. Although these may be used alone, it is preferable to use two or more of them in combination, since the lubricity and anti-blocking effect can be maintained even under harsh environments.
　本発明のヒートシール性樹脂フィルムにおけるポリオレフィン系樹脂組成物は、本発明の目的を損なわない範囲で必要に応じて任意の層に適量の酸化防止剤、帯電防止剤、防曇剤、中和剤、造核剤、着色剤、その他の添加剤及び無機質充填剤等を配合することができる。酸化防止剤として、フェノール系やホスファイト系の併用、もしくは一分子中にフェノール系とホスファイト系の骨格を有したものを単独使用が挙げられる。中和剤として、ステアリン酸カルシウム等が挙げられる。 The polyolefin resin composition in the heat-sealable resin film of the present invention may contain an appropriate amount of an antioxidant, an antistatic agent, an antifogging agent, and a neutralizing agent in any layer as necessary within a range that does not impair the purpose of the present invention. , a nucleating agent, a coloring agent, other additives, an inorganic filler, etc. can be blended. As the antioxidant, phenol type and phosphite type antioxidants may be used in combination, or one having a phenol type and phosphite type skeleton in one molecule may be used alone. Examples of neutralizing agents include calcium stearate.
（ヒートシール性樹脂フィルムの製造方法）
　本発明のヒートシール性樹脂フィルムは単層フィルムであっても良く、２層又は３層以上の多層フィルムであっても良い。３層構成の場合は中間層に製造工程ででた半製品や製造後の製品フィルムをリサイクルしたペレットを添加することにより、ヒートシールエネルギーや耐破袋性を損なうことなくコストを下げたり、融点の低いプロピレン－αオレフィンランダム共重合体をシール層のみに添加し、中間層やラミネート層は融点の高いプロピレン－αオレフィンランダム共重合体を主体として使用する等、各層で組成が若干異なる樹脂を使用することよって、よりその効果を高めることができる。 (Method for producing heat-sealable resin film)
The heat-sealable resin film of the present invention may be a single layer film or a multilayer film having two or more layers. In the case of a three-layer structure, by adding pellets recycled from semi-finished products produced during the manufacturing process and product film after manufacturing to the middle layer, it is possible to reduce costs without sacrificing heat-sealing energy or bag breakage resistance, and to increase the melting point. A propylene-α-olefin random copolymer with a low melting point is added only to the sealing layer, while a propylene-α-olefin random copolymer with a high melting point is mainly used in the intermediate layer and laminate layer. Each layer uses resin with a slightly different composition. By using it, the effect can be further enhanced.
　本発明のヒートシール性樹脂フィルムの成形方法は、例えば、インフレーション方式、Ｔダイ方式が使用できるが、透明性を高めるためや、ドラフトのかけ易さからＴダイ方式が好ましい。インフレーション方式は冷却媒体が空気であるのに対し、Ｔダイ方式は冷却ロールを用いるため、冷却速度を高くするには有利な製造方法である。冷却速度を速めることにより、未延伸シートの結晶化を抑制できるため、後工程でロールによる延伸が有利となる。こうした理由からＴダイ方無配向のシートを式が好ましい。 As a method for forming the heat-sealable resin film of the present invention, for example, an inflation method or a T-die method can be used, but the T-die method is preferable in order to improve transparency and ease of drafting. The inflation method uses air as the cooling medium, whereas the T-die method uses cooling rolls, so it is an advantageous manufacturing method for increasing the cooling rate. By increasing the cooling rate, crystallization of the unstretched sheet can be suppressed, so stretching with rolls is advantageous in the subsequent process. For these reasons, it is preferable to use a sheet with no orientation in the T-die direction.
　溶融した原料樹脂をキャスティングし、無配向のシートを得る際の冷却ロールの温度の下限は好ましくは１５℃であり、より好ましくは２０℃である。上記未満であると、冷却ロールに結露が発生し、密着不足となることがある。冷却ロールの上限は好ましくは６０℃でより好ましくは５０℃である。上記を超えると透明性が悪化することがある。 The lower limit of the temperature of the cooling roll when casting the molten raw resin to obtain a non-oriented sheet is preferably 15°C, more preferably 20°C. If it is less than the above, dew condensation may occur on the cooling roll, resulting in insufficient adhesion. The upper limit of the cooling roll is preferably 60°C, more preferably 50°C. If it exceeds the above, transparency may deteriorate.
　無配向のシートを延伸する方式は特に限定するものではなく、例えば、インフレーション方式、テンター横延伸方式、ロール縦延伸方式が使用できるが、配向の制御のし易さからロール縦延伸方式が好ましい。ここでいう縦延伸とは、原料樹脂組成物をキャスティングしてから延伸したフィルムを巻取る工程までのフィルムが流れる方向を意味し、横方向とは流れ方向と直角の方向を意味する。 The method for stretching an unoriented sheet is not particularly limited, and for example, an inflation method, a tenter horizontal stretching method, and a roll longitudinal stretching method can be used, but the roll longitudinal stretching method is preferable because of the ease of controlling the orientation. Longitudinal stretching here means the direction in which the film flows from the time of casting the raw resin composition to the step of winding up the stretched film, and the transverse direction means the direction perpendicular to the flow direction.
　無配向のシートを延伸することにより、直進カット性が発現するため好ましい。これは分子鎖の構造が延伸方向に規則的に配列されるためである。延伸倍率の下限は好ましくは３．３倍である。これより小さいと降伏強度が低下し、引裂強度が大きくなったり、直進カット性が劣ることがある。より好ましくは３．５倍であり、さらに好ましくは３．８倍である。延伸倍率の上限は好ましくは５．５倍である。これより大きいと過剰に配向が進行し、シールエネルギーが低下し、落下後の耐破袋性が悪化することがある。より好ましくは５．０倍であり、さらに好ましくは４．７倍である。 Stretching a non-oriented sheet is preferable because straight cutting properties are achieved. This is because the molecular chain structure is regularly arranged in the stretching direction. The lower limit of the stretching ratio is preferably 3.3 times. If it is smaller than this, the yield strength may decrease, the tear strength may increase, and the straight cutting performance may be poor. More preferably it is 3.5 times, and still more preferably 3.8 times. The upper limit of the stretching ratio is preferably 5.5 times. If it is larger than this, the orientation progresses excessively, the sealing energy decreases, and the bag breakage resistance after dropping may deteriorate. More preferably it is 5.0 times, and still more preferably 4.7 times.
　延伸ロール温度の下限は特に限定されないが、好ましくは８０℃である。これより低いとフィルムにかかる延伸応力が高くなり、フィルムが厚み変動を発生することがある。より好ましくは９０℃である。延伸ロール温度の上限は特に限定されないが好ましくは１４０℃である。これを越えると、フィルムにかかる延伸応力が低くなり、フィルムの引裂強度が低下するばかりか、延伸ロールにフィルムが融着してしまうことがあり、製造が困難になることがある。より好ましくは１３０℃であり、さらに好ましくは１２５℃であり、特に好ましくは１１５℃である。 The lower limit of the stretching roll temperature is not particularly limited, but is preferably 80°C. If it is lower than this, the stretching stress applied to the film becomes high, which may cause the film to fluctuate in thickness. More preferably it is 90°C. The upper limit of the stretching roll temperature is not particularly limited, but is preferably 140°C. If it exceeds this range, the stretching stress applied to the film becomes low, which not only reduces the tear strength of the film, but also causes the film to fuse to the stretching rolls, making production difficult. The temperature is more preferably 130°C, further preferably 125°C, particularly preferably 115°C.
　未延伸シートを延伸工程に導入する前に予熱ロールに接触させ、シート温度を上げておくことが好ましい。無配向のシートを延伸する際の予熱ロール温度の下限は特に限定されないが、好ましくは８０℃であり、より好ましくは９０℃である。上記未満であると延伸応力が高くなり、厚み変動を発生することがある。予熱ロール温度の上限は特に限定されないが、好ましくは１４０℃であり、より好ましくは１３０℃であり、さらに好ましくは１２５℃である。上記以上であると、熱収縮率やレトルト収縮率が増大することがある。これは延伸前の熱結晶化を抑制し延伸後の残留応力を小さくすることができるためである。 It is preferable to bring the unstretched sheet into contact with a preheating roll to raise the sheet temperature before introducing it into the stretching process. The lower limit of the preheating roll temperature when stretching a non-oriented sheet is not particularly limited, but is preferably 80°C, more preferably 90°C. When it is less than the above, the stretching stress becomes high and thickness fluctuation may occur. The upper limit of the preheat roll temperature is not particularly limited, but is preferably 140°C, more preferably 130°C, and even more preferably 125°C. If it is more than the above, the heat shrinkage rate and retort shrinkage rate may increase. This is because thermal crystallization before stretching can be suppressed and residual stress after stretching can be reduced.
　縦延伸工程を経たフィルムには、熱収縮を抑制するためにアニール処理を行うことが好ましい。アニール処理方式には、ロール加熱方式、テンター方式等があるが、設備の簡略さやメンテナンスのし易さからロール加熱方式が好ましい。アニール処理することによって、フィルムの内部応力を低下させることで、フィルムの熱収縮を抑えることができるが、熱収縮率以外の特性に悪影響を与える場合がある。しかし、エチレン－ブテン共重合エラストマー、及びプロピレン－ブテン共重合エラストマーを併用することによりその悪影響を抑えることができる。 The film that has undergone the longitudinal stretching process is preferably subjected to an annealing treatment in order to suppress thermal shrinkage. Annealing methods include a roll heating method, a tenter method, and the like, but the roll heating method is preferable because of the simplicity of the equipment and ease of maintenance. Annealing can reduce the internal stress of the film and thereby suppress the thermal shrinkage of the film, but it may adversely affect properties other than the thermal shrinkage rate. However, by using an ethylene-butene copolymer elastomer and a propylene-butene copolymer elastomer in combination, this adverse effect can be suppressed.
　アニール処理温度の下限は特に限定されないが、好ましくは８０℃である。上記未満であると熱収縮率が高くなったり、引裂強度が大きくなったり、製袋後やレトルト後の包装袋の仕上がりが悪化することがある。より好ましくは１００℃であり、１１０℃が特に好ましい。アニール処理温度の上限は好ましくは１４０℃である。アニール処理温度が高い方が、熱収縮率が低下しやすいが、１４０℃以下であると、フィルム厚みむらが生じにくく、フィルムが製造設備に融着したり、透明性、シール性、耐破袋性が低下すしにくい。より好ましくは１３５℃であり、特に好ましくは１３０℃である。 The lower limit of the annealing temperature is not particularly limited, but is preferably 80°C. If it is less than the above, the thermal shrinkage rate may become high, the tear strength may become high, and the finish of the packaging bag after bag making or retorting may deteriorate. The temperature is more preferably 100°C, and particularly preferably 110°C. The upper limit of the annealing temperature is preferably 140°C. The higher the annealing temperature, the more likely the thermal shrinkage rate will decrease, but if the annealing temperature is 140°C or lower, it will be difficult to cause uneven film thickness, and the film will not be fused to the manufacturing equipment, and the transparency, sealability, and tear resistance of the bag will be reduced. Decreased sexiness and difficulty in swallowing. The temperature is more preferably 135°C, particularly preferably 130°C.
　アニール工程ではロールの回転速度を小さくする等、フィルムの搬送速度を順次遅くする等して、緩和工程を設けることができる。緩和工程を設けることにより、製造されたヒートシール性樹脂フィルムの熱収縮率を小さくすることができる。緩和工程の緩和率の上限は、好ましくは１０％であり、より好ましくは８％である。１０％以下であると搬送中のフィルムがたるみにくく、工程への巻き付きを起こしにくいため好ましい。緩和率の下限は、好ましくは１％であり、より好ましくは３％である。１％以上であると、ヒートシール性樹脂フィルムの熱収縮率が高くなりにくいため好ましい。 In the annealing step, a relaxation step can be provided by sequentially slowing down the transport speed of the film, such as by decreasing the rotational speed of the roll. By providing the relaxation step, the heat shrinkage rate of the manufactured heat-sealable resin film can be reduced. The upper limit of the relaxation rate in the relaxation step is preferably 10%, more preferably 8%. If it is 10% or less, the film is less likely to sag during transportation and is less likely to be wrapped around the process, which is preferable. The lower limit of the relaxation rate is preferably 1%, more preferably 3%. When it is 1% or more, the heat shrinkage rate of the heat-sealable resin film is less likely to increase, which is preferable.
　本発明においては、以上に記述したヒートシール性樹脂フィルムと、他の素材の二軸配向フィルムをラミネートする側の表面をコロナ処理等で表面を活性化させるのが好ましい。該対応により基材フィルムとのラミネート強度が向上する。 In the present invention, it is preferable to activate the surface of the side on which the heat-sealable resin film described above and the biaxially oriented film of another material are laminated by corona treatment or the like. This response improves the lamination strength with the base film.
（フィルム厚み）
　本発明のヒートシール性樹脂フィルムの厚みの下限は、好ましくは２０μｍであり、より好ましくは３０μｍであり、さらに好ましくは４０μｍであり、特に好ましくは５０μｍである。２０μｍ以上であると基材フィルムの厚みに対し相対的に厚くなるため、積層体としての直進カット性が悪化しにくく、またフィルムの腰感が得られ加工しやすい他、耐衝撃性が得られやすく耐破袋性が得られやすいため好ましい。フィルム厚みの上限は、好ましくは１５０μｍであり、より好ましくは１００μｍであり、さらに好ましくは８０μｍである。１５０μｍ以下であるとフィルムの腰感が強すぎず加工しやすくなるあるほか、好適な包装体を製造しやすいため好ましい。 (Film thickness)
The lower limit of the thickness of the heat-sealable resin film of the present invention is preferably 20 μm, more preferably 30 μm, still more preferably 40 μm, particularly preferably 50 μm. If it is 20 μm or more, it will be thicker relative to the thickness of the base film, so the straight cutability of the laminate will not deteriorate easily, and the film will have a stiff feel and be easier to process, as well as impact resistance. This is preferable because it is easy to obtain bag breakage resistance. The upper limit of the film thickness is preferably 150 μm, more preferably 100 μm, and still more preferably 80 μm. A thickness of 150 μm or less is preferable because the film does not have too much stiffness and is easy to process, and it is also easy to manufacture a suitable package.
（熱収縮率）
　本発明で用いるヒートシール性樹脂フィルムの長手方向及び幅方向のうち熱収縮率が大きい方向の１２０℃における熱収縮率の上限は、３５％であることが好ましく、２５％であることがより好ましい。３５％以下であるとヒートシール時や包装体の湿熱処理時の収縮が小さくなり、包装体の外観を損ないにくいため好ましい。より好ましくは２０％であり、さらに好ましくは１７％である。本発明のヒートシール性樹脂フィルムの長手方向及び幅方向のうち熱収縮率が大きい方向の熱収縮率の下限は、２％であることが好ましい。２％以上であれば、アニール温度やアニール時間を著しく大きくする必要がないため、外観が悪化しにくいため好ましい。本発明で用いるヒートシール性樹脂フィルムの長手方向及び幅方向のうち熱収縮率が小さい方向の熱収縮率の上限は、１％であることが好ましい。１％を超えると、熱収縮率が大きい方向の引裂強度が大きくなったり、あるいは直進カット性に劣る。好ましくは０．５％である。本発明で用いるヒートシール性樹脂フィルムの長手方向及び幅方向のうち熱収縮率が小さい方向の熱収縮率の下限は－５％である。－５％以上であると、ヒートシール工程でフィルムに伸びが発生しにくく、包装体の外観が悪化しにくいため好ましい。より好ましくは－３％である。 (Heat shrinkage rate)
The upper limit of the heat shrinkage rate at 120°C in the longitudinal direction and width direction of the heat-sealable resin film used in the present invention is preferably 35%, more preferably 25%. . If it is 35% or less, shrinkage during heat sealing or moist heat treatment of the package will be small, and the appearance of the package will not be easily damaged, which is preferable. More preferably it is 20%, still more preferably 17%. The lower limit of the heat shrinkage rate in the longitudinal direction and width direction of the heat-sealable resin film of the present invention in the direction where the heat shrinkage rate is large is preferably 2%. If it is 2% or more, it is preferable because there is no need to significantly increase the annealing temperature or annealing time, and the appearance is less likely to deteriorate. The upper limit of the heat shrinkage rate in the longitudinal direction and the width direction of the heat-sealable resin film used in the present invention in the direction where the heat shrinkage rate is smaller is preferably 1%. If it exceeds 1%, the tear strength in the direction of high heat shrinkage will increase or the straight cutting performance will be poor. Preferably it is 0.5%. The lower limit of the heat shrinkage rate in the longitudinal direction and width direction of the heat-sealable resin film used in the present invention in the direction where the heat shrinkage rate is smaller is -5%. If it is -5% or more, the film is less likely to stretch during the heat sealing process and the appearance of the package is less likely to deteriorate, which is preferable. More preferably -3%.
（長手方向の配向係数）
　本発明で使用する長手方向の配向係数ΔＮｘは式１により計算することができる。
　ΔＮｘ＝Ｎｘ－（Ｎｙ＋Ｎｚ）／２　（式１）
　Ｎｘ：長手方向の屈折率、Ｎｙ：長手方向に対し垂直方向の屈折率、Ｎｚ：面方向の屈折率
　本発明のヒートシール性樹脂フィルムの長手方向の配向係数ΔＮｘの下限は、好ましくは０．０１０であり、より好ましくは０．０１５であり、更に好ましくは０．０２０である。０．０１０以上であると包装体の直進カット性が得られやすいため好ましい。長手方向の配向係数ΔＮｘの上限は好ましくは０．０２７０であり、より好ましくは０．０２６である。０．０２７０以下であるとシール強度が低下しにくいため好ましい。 (Longitudinal orientation coefficient)
The longitudinal orientation coefficient ΔNx used in the present invention can be calculated using Equation 1.
ΔNx=Nx-(Ny+Nz)/2 (Formula 1)
Nx: refractive index in the longitudinal direction, Ny: refractive index in the direction perpendicular to the longitudinal direction, Nz: refractive index in the planar direction The lower limit of the orientation coefficient ΔNx in the longitudinal direction of the heat-sealable resin film of the present invention is preferably 0. 010, more preferably 0.015, still more preferably 0.020. If it is 0.010 or more, it is preferable because the package can be easily cut in a straight line. The upper limit of the longitudinal orientation coefficient ΔNx is preferably 0.0270, more preferably 0.026. If it is 0.0270 or less, the seal strength is less likely to decrease, which is preferable.
（面配向係数）
　本発明で使用する面配向係数ΔＰは屈折率より計算することができる。面方向への配向係数は式２により計算することができる。
　ΔＰ＝（Ｎｘ＋Ｎｙ）／２－Ｎｚ（式２）
　Ｎｘ：長手方向の屈折率、Ｎｙ：長手方向に対し垂直方向の屈折率、Ｎｚ：面方向の屈折率
　本発明のヒートシール性樹脂フィルムの面方向の配向係数ΔＰの下限は、好ましくは０．００５０であり、より好ましくは０．０１００である。０．００５０以上であると包装体の突刺強度が得られやすいため好ましい。また、フィルムが配向することで腰感の確保に必要な剛性を得ることができるため好ましい。腰感の指標としてのループスティフネス評価については後述する。面配向係数ΔＰの上限は、好ましくは０．０１４５であり、より好ましくは０．０１４０であり、更に好ましくは０．０１３０である。０．０１４５以下であるとシール強度が低下しにくいため好ましい。 (planar orientation coefficient)
The plane orientation coefficient ΔP used in the present invention can be calculated from the refractive index. The orientation coefficient in the plane direction can be calculated using Equation 2.
ΔP=(Nx+Ny)/2-Nz (Formula 2)
Nx: refractive index in the longitudinal direction, Ny: refractive index in the direction perpendicular to the longitudinal direction, Nz: refractive index in the planar direction The lower limit of the orientation coefficient ΔP in the planar direction of the heat-sealable resin film of the present invention is preferably 0. 0050, more preferably 0.0100. A value of 0.0050 or more is preferable because the puncture strength of the package can be easily obtained. Further, it is preferable that the film is oriented because the rigidity necessary to ensure a firm feel can be obtained. Loop stiffness evaluation as an index of back feeling will be described later. The upper limit of the plane orientation coefficient ΔP is preferably 0.0145, more preferably 0.0140, and still more preferably 0.0130. If it is 0.0145 or less, the seal strength is less likely to decrease, which is preferable.
［接着剤層］
　本発明の包装材料では、基材フィルムとヒートシール性樹脂フィルムを貼り合わせる際に接着剤を用いたドライラミネート法によって積層することができる。本発明で用いられる接着剤層は、汎用的なラミネート用接着剤が使用できる。例えば、ポリ（エステル）ウレタン系、ポリエステル系、ポリアミド系、エポキシ系、ポリ（メタ）アクリル系、ポリエチレンイミン系、エチレン－（メタ）アクリル酸系、ポリ酢酸ビニル系、（変性）ポリオレフィン系、ポリブタジェン系、ワックス系、カゼイン系等を主成分とする（無）溶剤型、水性型、熱溶融型の接着剤を使用することができる。この中でも、耐熱性と、各基材の寸法変化に追随できる柔軟性を考慮すると、ウレタン系又はポリエステル系が好ましい。上記接着剤層の積層方法としては、例えば、ダイレクトグラビアコート法、リバースグラビアコート法、キスコート法、ダイコート法、ロールコート法、ディップコート法、ナイフコート法、スプレーコート法、フォンテンコート法、その他の方法で塗布することができ、十分な接着性を発現するため、乾燥後の塗工量は１～８ｇ／ｍ２が好ましい。より好ましくは２～７ｇ／ｍ２、さらに好ましくは３～６ｇ／ｍ２である。塗工量が１ｇ／ｍ２未満であると、全面で貼り合せることが困難になり、接着力が低下する。また、８ｇ／ｍ２以上を超えると、膜の完全な硬化に時間がかかり、未反応物が残りやすく、接着力が低下する。 [Adhesive layer]
In the packaging material of the present invention, the base film and the heat-sealable resin film can be laminated by a dry lamination method using an adhesive. As the adhesive layer used in the present invention, a general-purpose laminating adhesive can be used. For example, poly(ester) urethane type, polyester type, polyamide type, epoxy type, poly(meth)acrylic type, polyethyleneimine type, ethylene-(meth)acrylic acid type, polyvinyl acetate type, (modified) polyolefin type, polybutadiene type. Solvent-based, water-based, or hot-melt type adhesives whose main component is a wax-based adhesive, a wax-based adhesive, a casein-based adhesive, or the like can be used. Among these, urethane-based or polyester-based materials are preferred in consideration of heat resistance and flexibility that can follow dimensional changes of each base material. Examples of laminating methods for the adhesive layer include direct gravure coating, reverse gravure coating, kiss coating, die coating, roll coating, dip coating, knife coating, spray coating, fontaine coating, and others. The coating amount after drying is preferably 1 to 8 g/m 2 in order to develop sufficient adhesion. More preferably 2 to 7 g/m 2 , still more preferably 3 to 6 g/m 2 . If the coating amount is less than 1 g/m 2 , it becomes difficult to bond the entire surface, and the adhesive strength decreases. On the other hand, if it exceeds 8 g/m 2 or more, it takes time for the film to completely cure, unreacted substances tend to remain, and the adhesive strength decreases.
［印刷層］
　さらに、本発明の包装材料には、基材フィルムとヒートシール性樹脂フィルムとの間又はその外側に、印刷層を少なくとも１層以上積層してもよい。 [Printing layer]
Furthermore, in the packaging material of the present invention, at least one printed layer may be laminated between the base film and the heat-sealable resin film or on the outside thereof.
　印刷層を形成する印刷インクとしては、水性及び溶媒系の樹脂含有印刷インクが好ましく使用できる。ここで印刷インクに使用される樹脂としては、アクリル系樹脂、ウレタン系樹脂、ポリエステル系樹脂、塩化ビニル系樹脂、酢酸ビニル共重合樹脂及びこれらの混合物が例示される。印刷インクには、帯電防止剤、光線遮断剤、紫外線吸収剤、可塑剤、滑剤、フィラー、着色剤、安定剤、潤滑剤、消泡剤、架橋剤、耐ブロッキング剤、酸化防止剤等の公知の添加剤を含有させてもよい。印刷層を設けるための印刷方法としては、特に限定されず、オフセット印刷法、グラビア印刷法、スクリーン印刷法等の公知の印刷方法が使用できる。印刷後の溶媒の乾燥には、熱風乾燥、熱ロール乾燥、赤外線乾燥等公知の乾燥方法が使用できる。 As the printing ink for forming the printing layer, aqueous and solvent-based resin-containing printing inks can be preferably used. Examples of resins used in the printing ink include acrylic resins, urethane resins, polyester resins, vinyl chloride resins, vinyl acetate copolymer resins, and mixtures thereof. The printing ink contains known antistatic agents, light blocking agents, ultraviolet absorbers, plasticizers, lubricants, fillers, colorants, stabilizers, lubricants, antifoaming agents, crosslinking agents, anti-blocking agents, antioxidants, etc. may also contain additives. The printing method for providing the printed layer is not particularly limited, and known printing methods such as offset printing, gravure printing, and screen printing can be used. For drying the solvent after printing, known drying methods such as hot air drying, hot roll drying, and infrared drying can be used.
［包装材料の特性］
　本発明の包装材料としては、考え得る任意の積層構成を取ることができる。環境負荷の面からは、バリア層を有する基材フィルム１枚とヒートシール性樹脂フィルムを貼り合わせた構成のものが使用材料・貼合わせ工程の回数が最も少なく好ましい。一方で、前述の通り、強靭性やガスバリア性能の向上の観点からは、例えば、ガスバリア層を積層したフィルムを、ガスバリア層を有さない基材フィルムとヒートシール性樹脂層を有する熱可塑性共重合体で挟みこむ形でラミネートした積層体も好ましい構成の一つとして挙げられる。その際、印刷層を表側の基材フィルム上に積層することで、ガスバリア層を有するフィルム上に印刷する必要がなくなるという利点も上げられる。その他、隠蔽性を高めるために白色の基材フィルムやヒートシール性樹脂フィルムと貼り合わせたり、遮光性のために紫外線カットフィルムと貼り合わせること等も好適な構成の一つとなる。 [Characteristics of packaging material]
The packaging material of the present invention can have any conceivable laminated structure. From the viewpoint of environmental impact, a structure in which one base film having a barrier layer and a heat-sealable resin film are bonded together is preferable because it requires the least number of materials and bonding steps. On the other hand, as mentioned above, from the perspective of improving toughness and gas barrier performance, for example, a film with a laminated gas barrier layer can be replaced with a thermoplastic copolymer film with a base film without a gas barrier layer and a heat-sealable resin layer. A laminate that is laminated in such a way that they are sandwiched together can also be cited as one of the preferred configurations. At this time, by laminating the printing layer on the front base film, there is also the advantage that there is no need to print on the film having the gas barrier layer. Other suitable configurations include laminating with a white base film or a heat-sealable resin film to enhance concealability, and laminating with an ultraviolet cut film for light-shielding properties.
　本発明の包装材料では、前記材料から剥離した基材フィルムの少なくとも１枚が、熱機械分析装置により測定した１３０℃における加熱伸び率がＭＤ方向、ＴＤ方向のいずれも６％以下であることが必要である。これにより、包装体として使用する際に必要な耐熱性を確保することができる。例えば、１３０℃以上の高温でヒートシールする際の仕上がり性が良好となり、シール強度も安定することや、レトルト等の過酷な湿熱処理を行った際の寸法変化や外観変化が少なく仕上がりのよい包装体とすることができる。１３０℃でのＭＤ方向、及びＴＤ方向の加熱伸び率は、好ましくは５．５％以下、より好ましくは５．０％以下、さらに好ましくは４．５％以下であり、下限は０％が好ましい。１３０℃での加熱伸び率が前記範囲外の場合は、包装体としての耐熱性が低下し、結果的にシール時や湿熱処理時の外観不良が生じるおそれがある。本発明において、加熱伸び率は熱機械分析装置（ＴＭＡ）法で測定される値であり、より詳細には実施例に記載の方法による。ＴＭＡ法を用いることにより、ある一定の張力がかかった状態での熱負荷による寸法変化を定量的に判断することができる。また、それぞれの加工時を想定した張力や熱量を任意に設定することもできるため、実際の加工に類似した挙動を確認するための指標となると考えられる。 In the packaging material of the present invention, at least one of the base films peeled from the material has a heat elongation rate of 6% or less in both the MD direction and the TD direction at 130°C as measured by a thermomechanical analyzer. is necessary. Thereby, the heat resistance required when used as a package can be ensured. For example, when heat-sealing at a high temperature of 130°C or higher, the finish is good and the sealing strength is stable, and packaging has a good finish with less dimensional and appearance changes when subjected to harsh moist heat treatment such as retorting. It can be a body. The heat elongation rate in the MD direction and the TD direction at 130°C is preferably 5.5% or less, more preferably 5.0% or less, even more preferably 4.5% or less, and the lower limit is preferably 0%. . If the heating elongation rate at 130° C. is outside the above range, the heat resistance as a package may be reduced, resulting in poor appearance during sealing or moist heat treatment. In the present invention, the heating elongation rate is a value measured by a thermomechanical analyzer (TMA) method, and more specifically by the method described in Examples. By using the TMA method, it is possible to quantitatively determine dimensional changes due to thermal load under a certain tension. In addition, since the tension and heat amount can be set arbitrarily based on the assumption of each processing time, it is considered to be an indicator for confirming behavior similar to actual processing.
　［基材フィルム］の欄で述べた通り、本発明において、包装材料から剥離した基材フィルムの加熱伸び率を前記の範囲内とするためには、１３０℃での加熱伸び率が、ＭＤ方向、ＴＤ方向のいずれも１０％以下である基材フィルムを使用することが好ましい。さらに、基材フィルムに後加熱処理を施すことで加熱伸び率を低下させることができる。加熱処理の手段としては、基材フィルムを乾燥炉でアニール処理することや、前述の無機薄膜層（Ｂ）等のガスバリア層形成工程やアンカーコート層（Ｃ）・保護層（Ｄ）塗工工程における熱付加によっても可能である。この際の熱付加条件として、加熱時にフィルムの表面温度が６５℃以上になることが好ましく、より好ましくは７０℃以上、さらに好ましくは７５℃以上である。ただし、フィルム温度が９０℃以上になると逆に伸縮が大きくなってしまいシワ等の品位低下につながるおそれがあるため、熱付加の上限は９０℃である。 As mentioned in the [Substrate film] section, in the present invention, in order to keep the heat elongation rate of the base film peeled from the packaging material within the above range, the heat elongation rate at 130°C must be in the MD direction. , it is preferable to use a base film having a thickness of 10% or less in both the TD direction. Furthermore, the heating elongation rate can be reduced by subjecting the base film to post-heat treatment. Heat treatment means include annealing the base film in a drying oven, the above-mentioned gas barrier layer formation process such as the inorganic thin film layer (B), and the anchor coat layer (C)/protective layer (D) coating process. It is also possible by adding heat at As for the heat addition conditions at this time, it is preferable that the surface temperature of the film be 65° C. or higher during heating, more preferably 70° C. or higher, and still more preferably 75° C. or higher. However, if the film temperature exceeds 90°C, expansion and contraction will increase, which may lead to deterioration of quality such as wrinkles, so the upper limit of heat addition is 90°C.
　本発明の包装材料は、２３℃×６５％ＲＨ条件下における酸素透過度が６０ｍｌ／ｍ２・ｄ・ＭＰａ以下となることで、良好なガスバリア性を発現することができる。さらに、各フィルム上にバリア層を設けることで、好ましくは５０ｍｌ／ｍ２・ｄ・ＭＰａ以下、より好ましくは４０ｍｌ／ｍ２・ｄ・ＭＰａ以下とすることができる。酸素透過度が６０ｍｌ／ｍ２・ｄ・ＭＰａを超えると、高いガスバリア性が要求される用途に対応することが難しくなる。他方、酸素透過度の好ましい下限は、０．５ｍｌ／ｍ２・ｄ・ＭＰａ以上である。酸素透過度がいずれも０．５ｍｌ／ｍ２・ｄ・ＭＰａ未満であると、バリア性能には優れるが残留溶剤が袋の外側に透過しにくくなり、相対的に内容物への移行量が増えるおそれがあるので好ましくない。 The packaging material of the present invention can exhibit good gas barrier properties when the oxygen permeability under conditions of 23° C. and 65% RH is 60 ml/m 2 ·d·MPa or less. Furthermore, by providing a barrier layer on each film, it is possible to reduce the pressure to preferably 50 ml/m 2 ·d·MPa or less, more preferably 40 ml/m 2 ·d·MPa or less. When the oxygen permeability exceeds 60 ml/m 2 ·d·MPa, it becomes difficult to support applications requiring high gas barrier properties. On the other hand, a preferable lower limit of the oxygen permeability is 0.5 ml/m 2 ·d·MPa or more. If the oxygen permeability is less than 0.5 ml/ m2・d・MPa, the barrier performance will be excellent, but it will be difficult for the residual solvent to permeate to the outside of the bag, and the amount transferred to the contents will increase relatively. This is not preferable because there is a risk.
　本発明の包装材料は、９５℃×３０分ボイル処理後又は１２０℃×３０分レトルト処理後の２３℃×６５％ＲＨ条件下における酸素透過度が６０ｍｌ／ｍ２・ｄ・ＭＰａ以下となることが、良好なガスバリア性を発現する点で好ましい。さらに、各フィルム上にバリア層を設けることで、好ましくは５０ｍｌ／ｍ２・ｄ・ＭＰａ以下、より好ましくは４０ｍｌ／ｍ２・ｄ・ＭＰａ以下とすることができる。酸素透過度が６０ｍｌ／ｍ２・ｄ・ＭＰａを超えると、高いガスバリア性が要求される用途に対応することが難しくなる。他方、酸素透過度の好ましい下限は、０．５ｍｌ／ｍ２・ｄ・ＭＰａ以上である。酸素透過度がいずれも０．５ｍｌ／ｍ２・ｄ・ＭＰａ未満であると、バリア性能には優れるが残留溶剤が袋の外側に透過しにくくなり、相対的に内容物への移行量が増えるおそれがあるので好ましくない。 The packaging material of the present invention should have an oxygen permeability of 60 ml/m 2・d・MPa or less under 23°C x 65% RH after boiling at 95°C for 30 minutes or retorting at 120°C for 30 minutes. is preferable in that it exhibits good gas barrier properties. Furthermore, by providing a barrier layer on each film, it is possible to reduce the pressure to preferably 50 ml/m 2 ·d·MPa or less, more preferably 40 ml/m 2 ·d·MPa or less. When the oxygen permeability exceeds 60 ml/m 2 ·d·MPa, it becomes difficult to support applications requiring high gas barrier properties. On the other hand, a preferable lower limit of the oxygen permeability is 0.5 ml/m 2 ·d·MPa or more. If the oxygen permeability is less than 0.5 ml/ m2・d・MPa, the barrier performance will be excellent, but it will be difficult for the residual solvent to permeate to the outside of the bag, and the amount transferred to the contents will increase relatively. This is not preferable because there is a risk.
　本発明の包装材料は、４０℃×９０％ＲＨ条件下における水蒸気透過度がいずれも５．０ｇ／ｍ２・ｄ以下であることが、良好なガスバリア性を発現する点で好ましい。さらに各フィルム上にバリア層を設けることで、好ましくは４．０ｇ／ｍ２・ｄ以下、より好ましくは３．０ｇ／ｍ２・ｄ以下とすることができる。水蒸気透過度が５．０ｇ／ｍ２・ｄを超えると、高いガスバリア性が要求される用途に対応することが難しくなる。他方、水蒸気透過度の好ましい下限は、０．１ｇ／ｍ２・ｄ以上である。水蒸気透過度が０．１ｇ／ｍ２未満であると、バリア性能には優れるが残留溶剤が袋の外側に透過しにくくなり、相対的に内容物への移行量が増えるおそれがあるので好ましくない。 The packaging material of the present invention preferably has a water vapor permeability of 5.0 g/m 2 ·d or less under conditions of 40° C. and 90% RH in order to exhibit good gas barrier properties. Further, by providing a barrier layer on each film, the weight loss can be preferably 4.0 g/m 2 ·d or less, more preferably 3.0 g/m 2 ·d or less. When the water vapor permeability exceeds 5.0 g/m 2 ·d, it becomes difficult to support applications requiring high gas barrier properties. On the other hand, a preferable lower limit of water vapor permeability is 0.1 g/m 2 ·d or more. If the water vapor permeability is less than 0.1 g/ m2 , the barrier performance is excellent, but it becomes difficult for the residual solvent to permeate to the outside of the bag, and the amount transferred to the contents may increase relatively, so it is not preferable. .
　本発明の包装材料は、９５℃×３０分ボイル処理後又は１２０℃×３０分レトルト処理後の４０℃×９０％ＲＨ条件下における水蒸気透過度がいずれも５．０ｇ／ｍ２・ｄ以下であることが、良好なガスバリア性を発現する点で好ましい。さらに各フィルム上にバリア層を設けることで、好ましくは４．０ｇ／ｍ２・ｄ以下、より好ましくは３．０ｇ／ｍ２・ｄ以下とすることができる。水蒸気透過度が５．０ｇ／ｍ２・ｄを超えると、高いガスバリア性が要求される用途に対応することが難しくなる。他方、水蒸気透過度の好ましい下限は、０．１ｇ／ｍ２・ｄ以上である。水蒸気透過度が０．１ｇ／ｍ２未満であると、バリア性能には優れるが残留溶剤が袋の外側に透過しにくくなり、相対的に内容物への移行量が増えるおそれがあるので好ましくない。 The packaging material of the present invention has a water vapor permeability of 5.0 g/m 2 d or less under 40°C x 90% RH after boiling at 95°C for 30 minutes or retorting at 120°C for 30 minutes. It is preferable that there be a certain amount in order to exhibit good gas barrier properties. Further, by providing a barrier layer on each film, the weight loss can be preferably 4.0 g/m 2 ·d or less, more preferably 3.0 g/m 2 ·d or less. When the water vapor permeability exceeds 5.0 g/m 2 ·d, it becomes difficult to support applications requiring high gas barrier properties. On the other hand, a preferable lower limit of water vapor permeability is 0.1 g/m 2 ·d or more. If the water vapor permeability is less than 0.1 g/ m2 , the barrier performance is excellent, but it becomes difficult for the residual solvent to permeate to the outside of the bag, and the amount transferred to the contents may increase relatively, so it is not preferable. .
　本発明の包装材料は、直進カット性が１０ｍｍ以下である必要があることが好ましい。これにより、包装体として使用する際に好ましい易引き裂き性を確保することができるため好ましい。直進カット性は、好ましくは９ｍｍ以下、より好ましくは８ｍｍ以下、さらに好ましくは７ｍｍ以下である。直進カット性が１０ｍｍより大きい場合は、泣き別れ等の不具合が発生するおそれがある。直進カット性の測定方法の詳細は後述の実施例に示す。 It is preferable that the packaging material of the present invention needs to have straight cutability of 10 mm or less. This is preferable because favorable tearability can be ensured when used as a package. The straight cutting property is preferably 9 mm or less, more preferably 8 mm or less, and even more preferably 7 mm or less. If the straight cutting property is greater than 10 mm, problems such as separation may occur. Details of the method for measuring straight cutability are shown in Examples below.
　本発明の包装材料は、ループスティフネスの値が１４０ｍＮ／２５ｍｍ以上である必要がある。ループスティフネスとは、所定寸法の短冊状にカットしたフィルムを用いてループを形成し、このループを径方向に所定量だけ押しつぶした状態で測定したループの反発力をいい、フィルムの剛性を表す指標である。ループスティフネスの値を上記範囲とすることにより、例えば、自立性を有する包装体として使用する際に好ましい腰感を確保することができる。ループスティフネスの値は、好ましくは１４５ｍＮ／２５ｍｍ以上、より好ましくは１５０ｍＮ／２５ｍｍ以上、さらに好ましくは１５５ｍＮ／２５ｍｍ以上である。ループスティフネスの値が１４０ｍＮ／２５ｍｍより小さい場合は、袋の自立性が不十分となるおそれがある。ループスティフネスの測定方法の詳細は後述の実施例に示す。ループスティフネスの値は、ラミネート構成体に用いる各フィルムの種類や厚みを調整することで達成可能であるが、特に全体に対して主要な厚み比率を占めるヒートシール性樹脂の腰感の影響が大きい。［ヒートシール性樹脂フィルム］の欄で述べた通り、ヒートシール性樹脂の面配向係数をコントロールすることによりループスティフネスの値を所定の値とすることができる。フィルム厚みによっても調整は可能であるが、腰感を得ようとすると厚みを厚くすることになり、減容化の観点では好ましくないことや、コストアップにつながる懸念がある。 The packaging material of the present invention needs to have a loop stiffness value of 140 mN/25 mm or more. Loop stiffness refers to the repulsive force of the loop, which is measured by forming a loop using a film cut into strips of predetermined dimensions and compressing the loop by a predetermined amount in the radial direction, and is an index representing the stiffness of the film. It is. By setting the loop stiffness value within the above range, it is possible to ensure a preferable waist feeling when used as a self-supporting packaging body, for example. The loop stiffness value is preferably 145 mN/25 mm or more, more preferably 150 mN/25 mm or more, even more preferably 155 mN/25 mm or more. If the loop stiffness value is smaller than 140 mN/25 mm, the bag may not have sufficient self-supporting properties. Details of the method for measuring loop stiffness are shown in Examples below. Loop stiffness values can be achieved by adjusting the type and thickness of each film used in the laminate structure, but the stiffness of the heat-sealable resin, which accounts for the main thickness ratio to the whole, has a particularly large effect. . As described in the section of [Heat-sealable resin film], the loop stiffness value can be set to a predetermined value by controlling the planar orientation coefficient of the heat-sealable resin. Although it is possible to adjust the thickness of the film, if you try to obtain a firm feel, you will have to increase the thickness, which is not preferable from the perspective of volume reduction, and there is a concern that it will lead to an increase in cost.
　本発明の包装材料のヒートシール層樹脂層同士を温度１６０℃又は１７０℃で、シールバー圧力０．２ＭＰａ、シール時間２秒でヒートシールした際のヒートシール強度が１５Ｎ／１５ｍｍ以上であることが好ましい。ヒートシール強度が１５Ｎ／１５ｍｍ未満であると、シール部分が剥離しやすくなるため、内容物量が多い用途には使用できない等、包装袋としての用途が限定されてしまう。ヒートシール強度は１６Ｎ／１５ｍｍ以上が好ましく、１７Ｎ／１５ｍｍ以上がより好ましい。 The heat-sealing strength of the heat-sealing layer resin layers of the packaging material of the present invention when heat-sealing each other at a temperature of 160°C or 170°C, a seal bar pressure of 0.2 MPa, and a sealing time of 2 seconds is 15 N/15 mm or more. preferable. If the heat seal strength is less than 15 N/15 mm, the sealed portion will easily peel off, so the bag cannot be used for applications with a large amount of contents, and its use as a packaging bag will be limited. The heat seal strength is preferably 16 N/15 mm or more, more preferably 17 N/15 mm or more.
　本発明の包装材料ではヒートシール後の外観に優れることが好ましい。具体的にはシール部分にしわが寄ったり、袋がゆがんだりしないことが好ましい。シール後の外観を保つためには、前述の基材フィルムの加熱伸びを前述の所定範囲にすること及びヒートシール性樹脂フィルムの熱収縮率を前述の所定範囲にすることが挙げられる。 The packaging material of the present invention preferably has an excellent appearance after heat sealing. Specifically, it is preferable that the seal portion not wrinkle or the bag not be distorted. In order to maintain the appearance after sealing, it is possible to set the heat elongation of the base film to the predetermined range described above, and to set the heat shrinkage rate of the heat-sealable resin film to the predetermined range described above.
　本発明の包装材料におけるモノマテリアル化の評価基準として、各フィルム及び接着剤の総厚みに対するポリオレフィン系素材の厚みの比率をモノマテリアル（モノマテ）比率として算出した際、モノマテ比率は７０％以上であることが好ましい。より好ましくは８０％以上、さらに好ましくは９０％以上である。モノマテ比率をこの範囲とすることにより、リサイクルしやすい包材構成とすることができる。モノマテ比率が７０％未満であると、異素材由来の異物等によりリサイクルが困難になるおそれがある。なお、前述のように基材フィルムを構成するポリオレフィン系樹脂としてポリプロピレン系樹脂を用いることが好ましいが、ヒートシール性樹脂層にもポリプロピレン系樹脂を用いるとよりリサイクルしやすい構成とすることができる。使用するポリオレフィン系素材を全てポリプロピレン系樹脂とすれば、さらにリサイクルしやすい構成とすることができる。 As an evaluation standard for monomaterialization in the packaging material of the present invention, when the ratio of the thickness of the polyolefin material to the total thickness of each film and adhesive is calculated as a monomaterial (monomate) ratio, the monomate ratio is 70% or more. It is preferable. More preferably it is 80% or more, still more preferably 90% or more. By setting the monomate ratio within this range, the packaging material can be configured to be easily recycled. If the monomate ratio is less than 70%, recycling may become difficult due to foreign substances derived from different materials. Note that, as described above, it is preferable to use a polypropylene resin as the polyolefin resin constituting the base film, but if a polypropylene resin is also used for the heat-sealable resin layer, it can be more easily recycled. If all the polyolefin materials used are polypropylene resins, the structure can be made even easier to recycle.
　本発明の包装材料において、各フィルム及び接着剤の総厚みは２０～１４０μｍであることが好ましい。より好ましくは２５～１３５μｍ、さらに好ましくは３０～１３０μｍである。包装材料の総厚みをこの範囲とすることにより、前述の包装材料として必要な腰感、さらには強靭性やバリア性能等の必要な物性を発現できる包装体とすることができるため好ましい。総厚みが２０μｍ未満であると、袋としての腰感が足りず自立しないおそれがある。また、強靭性が足りず、袋が破けたり穴が開いたりするおそれがある。一方、総厚みが１４０μｍを超えると、腰感が強くなり過ぎ、取り扱いがしにくくなる他、包装体としてのコストアップにつながり経済的にも好ましくない。 In the packaging material of the present invention, the total thickness of each film and adhesive is preferably 20 to 140 μm. More preferably 25 to 135 μm, still more preferably 30 to 130 μm. By setting the total thickness of the packaging material within this range, it is possible to obtain a packaging body that can exhibit the necessary physical properties such as the stiffness necessary for the above-mentioned packaging material, as well as toughness and barrier performance, which is preferable. If the total thickness is less than 20 μm, the bag may not have enough elasticity and may not stand on its own. In addition, the bag may not be strong enough and the bag may tear or become punctured. On the other hand, when the total thickness exceeds 140 μm, it becomes too stiff and difficult to handle, and it also increases the cost of the package, which is not economically preferable.
　本発明の包装材料は、前述のように優れた耐熱性や直進カット性、腰感、バリア性能を有し、視認性にも優れることから、各種の包装体として使用できる。包装体の例としては、ボイル又はレトルトの殺菌処理用途、冷凍食品用途、真空包装用途、電子レンジ加熱用途等を例示できる。 As mentioned above, the packaging material of the present invention has excellent heat resistance, straight cutability, stiffness, and barrier performance, and is also excellent in visibility, so it can be used as a variety of packaging materials. Examples of packaging bodies include boil or retort sterilization applications, frozen food applications, vacuum packaging applications, and microwave heating applications.
　本発明の包装材料を用いた包装体の形態は特に限定されるものではなく種々の形態をとることができる。包装形態としては、三方・四方パウチ、スタンディングパウチ、スパウトパウチ等を例示できる。 The form of a package using the packaging material of the present invention is not particularly limited and can take various forms. Examples of packaging formats include three-sided/four-sided pouches, standing pouches, and spout pouches.
　本発明の包装材料を用いた包装袋に充填される内容物は、特に限定されるものではなく、内容物は、液体、粉体及びゲル体であってもよい。また、食品であっても非食品であってもよい。 The contents to be filled into a packaging bag using the packaging material of the present invention are not particularly limited, and the contents may be liquid, powder, or gel. Moreover, it may be food or non-food.
　次に、実施例により本発明をさらに詳細に説明するが、本発明は以下の例に限定されるものではない。なお、各種評価は次の測定法によって行った。 Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to the following examples. In addition, various evaluations were performed using the following measurement methods.
（１）各種フィルムの厚み
　ＪＩＳ　Ｋ７１３０－１９９９　Ａ法に準拠し、ダイアルゲージを用いて測定した。 (1) Thickness of various films Measured using a dial gauge in accordance with JIS K7130-1999 Method A.
（２）基材フィルム上の無機薄膜層（Ｂ）の組成・膜厚
　実施例、比較例で得られた積層フィルム（薄膜積層後）について、蛍光Ｘ線分析装置（（株）リガク製「ｓｕｐｅｒｍｉｎｉ２００」）を用いて、予め作成した検量線により膜厚と組成を測定した。なお、励起Ｘ線管の条件として５０ｋＶ、４．０ｍＡとした。 (2) Composition and film thickness of the inorganic thin film layer (B) on the base film The laminated films obtained in Examples and Comparative Examples (after laminating thin films) were analyzed using a fluorescent X-ray analyzer (Rigaku Co., Ltd. "supermini 200"). ”), the film thickness and composition were measured using a calibration curve prepared in advance. Note that the conditions of the excitation X-ray tube were 50 kV and 4.0 mA.
（３）基材フィルム上の被覆層（Ａ）・アンカーコート層（Ｃ）・保護層（Ｄ）の付着量
　各実施例及び比較例において、基材フィルム上に所定の被覆層（Ａ）・アンカーコート層（Ｃ）・保護層（Ｄ）を積層した段階で得られた各積層フィルムを試料とし、この試料から１００ｍｍ×１００ｍｍの試験片を切り出し、水、エタノール又はアセトンのいずれかによるコート層の拭き取りを行い、拭き取り前後のフィルムの質量変化から付着量を算出した。 (3) Adhesion amount of coating layer (A), anchor coat layer (C), and protective layer (D) on base film In each example and comparative example, a predetermined coating layer (A) and protective layer (A) were deposited on the base film. Each laminated film obtained at the stage of laminating the anchor coat layer (C) and the protective layer (D) was used as a sample, a 100 mm x 100 mm test piece was cut out from this sample, and a coat layer made of either water, ethanol, or acetone was cut out. The adhesion amount was calculated from the change in mass of the film before and after wiping.
（４）基材フィルムの加工後の外観評価方法
　各実施例及び比較例において、被覆層（Ａ）・無機薄膜層（Ｂ）・アンカーコート層（Ｃ）・保護層（Ｄ）を積層した後にフィルム外観を目視で評価した。
　○：欠点の発生がなく良好
　×：シワ、塗工ムラ、ハジキのいずれかの欠点が発生 (4) Appearance evaluation method after processing of base film In each example and comparative example, after laminating the coating layer (A), inorganic thin film layer (B), anchor coat layer (C), and protective layer (D) The appearance of the film was visually evaluated.
○: Good with no defects. ×: Any defects such as wrinkles, uneven coating, or repellency occur.
（５）基材フィルムの加熱伸び率（％）
　各実施例・比較例で使用した基材フィルムについて加熱伸び率を測定した。加熱伸び率は、熱機械分析装置（（株）島津製作所製「ＴＭＡ－６０」）を用いて、ＴＭＡ測定により求めた。
　ＭＤ方向の加熱伸び率は、実施例、比較例の基材フィルムを用いて、ＭＤ方向に幅３０ｍｍ、ＴＤ方向に幅４ｍｍとなるように短冊状サンプルを作製した。測定条件は、チャック間距離を１０ｍｍ、測定温度範囲を３０℃から１５０℃、昇温速度を２０℃／分、サンプル片にかける引張荷重を０．３９Ｎとした。昇温前のチャック間距離（ｍｍ）と１３０℃に到達したときのチャック間距離（ｍｍ）から、加熱伸び率を求めた。
　ＴＤ方向の加熱伸び率は、実施例、比較例の基材フィルムを用いて、ＴＤ方向に幅３０ｍｍ、ＭＤ方向に幅４ｍｍとなるように短冊状サンプルを作製した。測定条件は、チャック間距離を１０ｍｍ、測定温度範囲を３０℃から１５０℃、昇温速度を２０℃／分、サンプル片にかける引張荷重を０．３９Ｎとした。昇温前のチャック間距離（ｍｍ）と１３０℃に到達したときのチャック間距離（ｍｍ）から、加熱伸び率を求めた。
　１３０℃に到達したときの加熱伸び率（Ｓ１３０）（％）は以下の式により求めた。
（Ｓ１３０）＝（１３０℃に加熱した時のチャック間距離－昇温前のチャック間距離）／昇温前のチャック間距離×１００（％） (5) Heating elongation rate of base film (%)
The heating elongation rate was measured for the base film used in each Example and Comparative Example. The heating elongation rate was determined by TMA measurement using a thermomechanical analyzer ("TMA-60" manufactured by Shimadzu Corporation).
For the heat elongation rate in the MD direction, strip-shaped samples were prepared using the base films of Examples and Comparative Examples to have a width of 30 mm in the MD direction and a width of 4 mm in the TD direction. The measurement conditions were: the distance between the chucks was 10 mm, the measurement temperature range was from 30° C. to 150° C., the temperature increase rate was 20° C./min, and the tensile load applied to the sample piece was 0.39 N. The heating elongation rate was determined from the distance between the chucks (mm) before the temperature was raised and the distance between the chucks (mm) when the temperature reached 130°C.
For the heating elongation rate in the TD direction, strip-shaped samples were prepared using the base films of Examples and Comparative Examples to have a width of 30 mm in the TD direction and a width of 4 mm in the MD direction. The measurement conditions were: the distance between the chucks was 10 mm, the measurement temperature range was from 30° C. to 150° C., the temperature increase rate was 20° C./min, and the tensile load applied to the sample piece was 0.39 N. The heating elongation rate was determined from the distance between the chucks (mm) before the temperature was raised and the distance between the chucks (mm) when the temperature reached 130°C.
The heating elongation rate (S130) (%) when the temperature reached 130°C was determined by the following formula.
(S130) = (Distance between chucks when heated to 130°C - Distance between chucks before temperature rise) / Distance between chucks before temperature rise x 100 (%)
（６）基材フィルムの加工後寸法変化率の評価方法
　各実施例及び比較例において、被覆層（Ａ）・無機薄膜層（Ｂ）・アンカーコート層（Ｃ）・保護層（Ｄ）を積層する前のフィルム幅方向の長さＡと積層後（例えば、アンカーコート層、被覆層、無機薄膜層、保護層をすべて積層する場合は保護層積層後）のフィルム幅方向の長さＢを測定し、以下の式から求められる値Ｘを加工後の寸法変化率（％）として評価した。
　加工後の寸法変化率Ｘ＝（Ａ－Ｂ）／Ａ×１００（％） (6) Method for evaluating dimensional change rate of base film after processing In each example and comparative example, coating layer (A), inorganic thin film layer (B), anchor coat layer (C), and protective layer (D) were laminated. Measure the length A in the width direction of the film before lamination and the length B in the width direction of the film after lamination (for example, after lamination of the protective layer in the case of laminating all of the anchor coat layer, covering layer, inorganic thin film layer, and protective layer). The value X obtained from the following formula was evaluated as the dimensional change rate (%) after processing.
Dimensional change rate after processing X = (AB)/A x 100 (%)
（７）ヒートシール性樹脂フィルムの熱収縮率
　各実施例及び比較例において、ヒートシール性樹脂フィルムを１２０ｍｍ四方に切り出した。長手方向、幅方向それぞれに１００ｍｍの間隔となるよう、標線を記入した。１２０℃に保温したオーブン内にサンプルを吊り下げ、３０分間熱処理を行った。標線間の距離を測定し、下記式に従い、熱収縮率を計算した。Ｎ＝３で測定し、平均値を算出した。
　熱収縮率＝（熱処理前の標線長－熱処理後の標線長）／熱処理前の標線長×１００　（％）　 (7) Heat shrinkage rate of heat-sealable resin film In each of the Examples and Comparative Examples, the heat-sealable resin film was cut into 120 mm square pieces. Marked lines were drawn at intervals of 100 mm in each of the longitudinal and width directions. The sample was suspended in an oven kept at 120°C and heat treated for 30 minutes. The distance between the marked lines was measured, and the heat shrinkage rate was calculated according to the following formula. Measurements were made with N=3, and the average value was calculated.
Heat shrinkage rate = (Gauge length before heat treatment - Gauge length after heat treatment) / Gauge length before heat treatment x 100 (%)
（８）ヒートシール性樹脂フィルムの長手方向の配向係数、面配向係数
　各実施例及び比較例において、ＪＩＳ　Ｋ００６２：１９９９年の化学製品の屈折率測定法に準じて密度を評価した。Ｎ＝３で測定し、平均値を算出した。長手方向の配向係数ΔＮｘは式１により、面方向への配向係数ΔＰは式２により計算した。
　ΔＮｘ＝Ｎｘ－（Ｎｙ＋Ｎｚ）／２　　（式１）
　ΔＰ＝（Ｎｘ＋Ｎｙ）／２－Ｎｚ　　（式２） (8) Longitudinal orientation coefficient and planar orientation coefficient of heat-sealable resin film In each of the Examples and Comparative Examples, the density was evaluated according to JIS K0062:1999 refractive index measurement method for chemical products. Measurements were made with N=3, and the average value was calculated. The orientation coefficient ΔNx in the longitudinal direction was calculated using Equation 1, and the orientation coefficient ΔP in the planar direction was calculated using Equation 2.
ΔNx=Nx-(Ny+Nz)/2 (Formula 1)
ΔP=(Nx+Ny)/2-Nz (Formula 2)
［包装材料の作製］
（９）評価用包装材料の作製
　基材フィルムが１枚の場合、実施例、比較例に記載の基材フィルムにウレタン系２液硬化型接着剤（三井化学（株）製「タケラック（登録商標）Ａ５２５Ｓ」と「タケネート（登録商標）Ａ５０」を１３．５：１（質量比）の割合で配合）を８０℃乾燥処理後の厚みが３μｍになるよう塗布した後、後述する各種のヒートシール性樹脂フィルムを６０℃に加熱した金属ロール上でドライラミネートし、４０℃にて２日間（４８時間）エージングを施すことにより、評価用のラミネート積層体を得た。一方、基材フィルムが２枚の場合、実施例、比較例に記載の基材フィルムにウレタン系２液硬化型接着剤（三井化学（株）製「タケラック（登録商標）Ａ５２５Ｓ」と「タケネート（登録商標）Ａ５０」を１３．５：１（質量比）の割合で配合）を８０℃乾燥処理後の厚みが３μｍになるよう塗布した後、もう一枚の基材フィルムを６０℃に加熱した金属ロール上でドライラミネートして巻き取りロールとした。本ロールに同様の接着剤を８０℃乾燥処理後の厚みが３μｍになるよう塗布した後、後述するヒートシール性樹脂フィルムを６０℃に加熱した金属ロール上でドライラミネートし、４０℃にて２日間（４８時間）エージングを施すことにより、評価用の包装材料を得た。 [Preparation of packaging materials]
(9) Preparation of packaging material for evaluation When there is only one base film, the base film described in Examples and Comparative Examples is coated with a urethane-based two-component curing adhesive ("Takelac (registered trademark)" manufactured by Mitsui Chemicals, Inc.). ) A525S" and "Takenate (registered trademark) A50" in a ratio of 13.5:1 (mass ratio)) was applied to a thickness of 3 μm after drying at 80°C, and then various heat seals as described below were applied. A laminate laminate for evaluation was obtained by dry laminating the plastic film on a metal roll heated to 60°C and aging at 40°C for 2 days (48 hours). On the other hand, when there are two base films, the base films described in Examples and Comparative Examples are coated with urethane two-component curing adhesives ("Takelac (registered trademark) A525S" manufactured by Mitsui Chemicals, Ltd.) and "Takenate (trademark)". A50 (registered trademark) blended at a ratio of 13.5:1 (mass ratio)) was applied so that the thickness after drying at 80°C was 3 μm, and then another base film was heated to 60°C. It was dry laminated on a metal roll to form a take-up roll. A similar adhesive was applied to this roll so that the thickness after drying at 80°C was 3 μm, and then a heat-sealable resin film (described later) was dry-laminated on a metal roll heated to 60°C, and the film was dry-laminated at 40°C for 2 hours. A packaging material for evaluation was obtained by aging for 48 hours.
（１０）包装材料の酸素透過度の評価方法
　上記（９）で作製した包装材料について、ＪＩＳ－Ｋ７１２６　Ｂ法に準じて、酸素透過度測定装置（ＭＯＣＯＮ社製「ＯＸ－ＴＲＡＮ（登録商標）２／２２」）を用い、温度２３℃、湿度６５％ＲＨの雰囲気下で、酸素透過度を測定した。なお、酸素透過度の測定は、包装材料の基材フィルム側からヒートシール性樹脂層側に酸素が透過する方向で行った。他方、上記（９）で作製した包装材料に対して、９５℃の熱水中に３０分間保持するボイル処理、又は１２０℃の熱水中に３０分間保持するレトルト処理を行い、４０℃で１日間（２４時間）乾燥し、得られた湿熱処理後の包装材料について上記と同様にして酸素透過度（ボイル後、レトルト後）を測定した。表７中、酸素透過度を「ＯＴＲ」、ボイル後の酸素透過度を「ボイル後ＯＴＲ」、レトルト後の酸素透過度を「レトルト後ＯＴＲ」として表記する。 (10) Method for evaluating oxygen permeability of packaging materials The packaging materials produced in (9) above were tested using an oxygen permeability measuring device (“OX-TRAN (registered trademark) 2” manufactured by MOCON) in accordance with JIS-K7126 B method. /22'') in an atmosphere of a temperature of 23° C. and a humidity of 65% RH. The oxygen permeability was measured in the direction in which oxygen permeated from the base film side of the packaging material to the heat-sealable resin layer side. On the other hand, the packaging material prepared in (9) above was subjected to a boiling process in which it was held in hot water at 95°C for 30 minutes, or a retort process in which it was held in hot water at 120°C for 30 minutes, and then heated at 40°C for 1 hour. After drying for days (24 hours), the oxygen permeability (after boiling, after retorting) of the resulting packaging material after moist heat treatment was measured in the same manner as above. In Table 7, the oxygen permeability is expressed as "OTR", the oxygen permeability after boiling is expressed as "OTR after boiling", and the oxygen permeability after retorting is expressed as "OTR after retorting".
（１１）包装材料の水蒸気透過度の評価方法
　上記（９）で作製した包装材料について、ＪＩＳ－Ｋ７１２９　Ｂ法に準じて、水蒸気透過度測定装置（ＭＯＣＯＮ社製「ＰＥＲＭＡＴＲＡＮ－Ｗ　３／３３ＭＧ」）を用い、温度４０℃、湿度９０％ＲＨの雰囲気下で、水蒸気透過度を測定した。なお、水蒸気透過度の測定は、包装材料の基材フィルム側からヒートシール性樹脂側に向けて水蒸気が透過する方向で行った。他方、上記（９）で作製した包装材料に対して、９５℃の熱水中に３０分間保持するボイル処理、又は１２０℃の熱水中に３０分間保持するレトルト処理を行い、４０℃で１日間（２４時間）乾燥し、得られた湿熱処理後の包装材料について上記と同様にして酸素透過度（ボイル後、レトルト後）を測定した。表７中、水蒸気透過度を「ＷＶＴＲ」、ボイル後の水蒸気透過度を「ボイル後ＷＶＴＲ」、レトルト後の水蒸気透過度を「レトルト後ＷＶＴＲ」として表記する。 (11) Method for evaluating water vapor permeability of packaging materials For the packaging materials produced in (9) above, a water vapor permeability measurement device (“PERMATRAN-W 3/33MG” manufactured by MOCON) was used in accordance with JIS-K7129 B method. The water vapor permeability was measured in an atmosphere with a temperature of 40° C. and a humidity of 90% RH. The water vapor permeability was measured in the direction in which water vapor permeated from the base film side of the packaging material toward the heat-sealable resin side. On the other hand, the packaging material prepared in (9) above was subjected to a boiling process in which it was held in hot water at 95°C for 30 minutes, or a retort process in which it was held in hot water at 120°C for 30 minutes, and then heated at 40°C for 1 hour. After drying for days (24 hours), the oxygen permeability (after boiling, after retorting) of the resulting packaging material after moist heat treatment was measured in the same manner as above. In Table 7, the water vapor permeability is expressed as "WVTR", the water vapor permeability after boiling is expressed as "WVTR after boiling", and the water vapor permeability after retorting is expressed as "WVTR after retorting".
（１２）包装材料のヒートシール強度の評価方法
　上記（９）で作製した包装材料について、ＪＩＳ　Ｚ１７０７に準拠してヒートシール強度測定を行った。具体的な手順を示す。ヒートシーラーにて、サンプルのヒートシール面同士を接着した。ヒートシール条件は、上バー温度１６０℃又は１７０℃、下バー温度３０℃、圧力０．２ＭＰａ、時間２秒とした。接着サンプルは、シール幅が１５ｍｍとなるように切り出した。剥離強度は、万能引張試験機「ＤＳＳ－１００」（（株）島津製作所製）を用いて引張速度２００ｍｍ／分で測定した。剥離強度は、１５ｍｍあたりの強度（Ｎ／１５ｍｍ）で示した。なお、シール外観の評価としては、シワなくシールできたものを〇、一部にシワが生じたものを△、全面にシワが生じたものを×として相対評価した。 (12) Method for evaluating heat seal strength of packaging material The heat seal strength of the packaging material produced in (9) above was measured in accordance with JIS Z1707. Show specific steps. The heat-sealed surfaces of the samples were adhered using a heat sealer. The heat sealing conditions were an upper bar temperature of 160°C or 170°C, a lower bar temperature of 30°C, a pressure of 0.2 MPa, and a time of 2 seconds. The adhesive sample was cut out so that the seal width was 15 mm. The peel strength was measured using a universal tensile tester "DSS-100" (manufactured by Shimadzu Corporation) at a tensile speed of 200 mm/min. The peel strength was expressed as the strength per 15 mm (N/15 mm). As for the evaluation of the appearance of the seal, a relative evaluation was made as ○ if the seal could be sealed without wrinkles, △ if there were wrinkles in some parts, and × if wrinkles were formed on the entire surface.
（１３）包装材料から剥がした基材フィルムの加熱伸び率（％）
　上記（９）で作製した包装材料から剥離した基材フィルムに付いて加熱伸び率を測定した。加熱伸び率は、熱機械分析装置（（株）島津製作所製「ＴＭＡ－６０」）を用いて、ＴＭＡ測定により求めた。
　ＭＤ方向の加熱伸び率は、実施例、比較例の包装材料をＭＤ方向に幅８０ｍｍ、ＴＤ方向に幅３０ｍｍとなるように切り出し、接着剤層間で剥離させた基材フィルムから、さらにＭＤ方向に幅３０ｍｍ、ＴＤ方向に幅４ｍｍとなるように短冊を切り出してサンプルを作製した。測定条件は、チャック間距離を１０ｍｍ、測定温度範囲を３０℃から１５０℃、昇温速度を２０℃／分、サンプル片にかける引張荷重を０．３９Ｎとした。昇温前のチャック間距離（ｍｍ）と１３０℃に到達したときのチャック間距離（ｍｍ）から、加熱伸び率を求めた。
　ＴＤ方向の加熱伸び率は、実施例、比較例の包装材料をＴＤ方向に幅８０ｍｍ、ＭＤ方向に幅３０ｍｍとなるように切り出し、接着剤層間で剥離させた基材フィルムから、さらにＴＤ方向に幅３０ｍｍ、ＭＤ方向に幅４ｍｍとなるように短冊を切り出してサンプルを作製した。測定条件は、チャック間距離を１０ｍｍ、測定温度範囲を３０℃から１５０℃、昇温速度を２０℃／分、サンプル片にかける引張荷重を０．３９Ｎとした。昇温前のチャック間距離（ｍｍ）と１３０℃に到達したときのチャック間距離（ｍｍ）から、加熱伸び率を求めた。
　１３０℃に到達したときの加熱伸び率（Ｓ１３０）（％）は以下の式により求めた。
（Ｓ１３０）＝（１３０℃に加熱した時のチャック間距離－昇温前のチャック間距離）／昇温前のチャック間距離×１００（％） (13) Heating elongation rate (%) of the base film peeled off from the packaging material
The heating elongation rate of the base film peeled from the packaging material prepared in (9) above was measured. The heating elongation rate was determined by TMA measurement using a thermomechanical analyzer ("TMA-60" manufactured by Shimadzu Corporation).
The heating elongation rate in the MD direction was determined by cutting out the packaging materials of Examples and Comparative Examples to have a width of 80 mm in the MD direction and 30 mm in the TD direction, and then peeling the base film between the adhesive layers. A sample was prepared by cutting out a strip having a width of 30 mm and a width of 4 mm in the TD direction. The measurement conditions were: the distance between the chucks was 10 mm, the measurement temperature range was from 30° C. to 150° C., the temperature increase rate was 20° C./min, and the tensile load applied to the sample piece was 0.39 N. The heating elongation rate was determined from the distance between the chucks (mm) before the temperature was raised and the distance between the chucks (mm) when the temperature reached 130°C.
The heating elongation rate in the TD direction was determined by cutting out the packaging materials of Examples and Comparative Examples to a width of 80 mm in the TD direction and 30 mm in the MD direction, and then peeling the base film between the adhesive layers. A sample was prepared by cutting out a strip having a width of 30 mm and a width of 4 mm in the MD direction. The measurement conditions were: the distance between the chucks was 10 mm, the measurement temperature range was from 30° C. to 150° C., the temperature increase rate was 20° C./min, and the tensile load applied to the sample piece was 0.39 N. The heating elongation rate was determined from the distance between the chucks (mm) before the temperature was raised and the distance between the chucks (mm) when the temperature reached 130°C.
The heating elongation rate (S130) (%) when the temperature reached 130°C was determined by the following formula.
(S130) = (Distance between chucks when heated to 130°C - Distance between chucks before temperature rise) / Distance between chucks before temperature rise x 100 (%)
（１４）モノマテリアル化の評価基準：モノマテリアル比率
　上記（９）で作製した包装材料について、モノマテリアル化の評価基準として、各フィルム及び接着剤の総厚みに対するオレフィン系素材の厚みの比率をモノマテリアル（モノマテ）比率として算出した。 (14) Evaluation criteria for monomaterialization: Monomaterial ratio For the packaging materials produced in (9) above, the ratio of the thickness of the olefin material to the total thickness of each film and adhesive is used as the evaluation criterion for monomaterialization. Calculated as a material (monomate) ratio.
（１５）視認・レンジ適性の評価基準
　上記（９）で作製した包装材料について、視認・レンジ適性の評価基準として、包装体が透明かつバリア層にアルミ箔又はアルミ蒸着を使用していないものを〇とした。 (15) Evaluation criteria for visibility and microwave suitability Regarding the packaging materials produced in (9) above, the evaluation criteria for visibility and microwave suitability are that the packaging is transparent and does not use aluminum foil or aluminum vapor deposition for the barrier layer. I marked it as 〇.
（１６）包装材料の直進カット性
　上記（９）で作製した包装材料について、直進カット性を評価した。直進カット性とは積層体を引裂いた際に、一方向に平行して真直ぐに引裂ける性能を示す。測定は以下の方法で行った。実施例、比較例では延伸方向への直進カット性が発現するため、延伸方向への測定を実施した。積層体を延伸方向１５０ｍｍ、測定方向と垂直方向６０ｍｍ、の短冊に切り出し、短辺の中央部から測定方向に沿って３０ｍｍの切り込みを入れた。ＪＩＳ　Ｋ７１２８－１：１９９８に準じて、２００ｍｍ／ｍｉｎ±１０％の試験速度でサンプルを引き裂いた。切込み３０ｍｍを含まず延伸方向に１２０ｍｍ引き裂いた時点で、延伸方向と垂直方向に移動した距離を測定し、その絶対値を記録した。向かって右側の切片を上側のつかみ具に挟む場合、向かって左側の切片を上側のつかみ具に挟む場合の両方を各Ｎ＝３で測定を行い、それぞれの平均値を算出した。右側、左側の測定結果のうち、数値の大きい方を採用した。 (16) Straight cutability of packaging material Straight cutability of the packaging material prepared in (9) above was evaluated. Straight cutability refers to the ability to tear straight in parallel to one direction when the laminate is torn. The measurement was performed using the following method. In Examples and Comparative Examples, straight cutting properties in the stretching direction were exhibited, so measurements were performed in the stretching direction. The laminate was cut into strips with a length of 150 mm in the stretching direction and 60 mm in the direction perpendicular to the measurement direction, and a 30 mm incision was made along the measurement direction from the center of the short side. The sample was torn at a test speed of 200 mm/min±10% in accordance with JIS K7128-1:1998. When the film was torn 120 mm in the stretching direction, not including the 30 mm cut, the distance traveled in the direction perpendicular to the stretching direction was measured, and its absolute value was recorded. Measurements were performed with N=3 for both cases in which the section on the right side was held between the upper grips and when the section on the left side was held between the upper grips, and the respective average values were calculated. Of the measurement results on the right and left sides, the one with the larger value was adopted.
（１７）包装材料のループスティフネス
　上記（９）で作製した包装材料について、ループスティフネスを測定した。幅２５ｍｍ、１１０ｍｍの短冊状フィルムとして切り出し、短冊状フィルムの長手方向が測定対象の方向に一致するようにした。切り出した短冊状フィルムを（株）東洋精機製作所製ループスティフネステスターにセットし反発力を測定した。測定周波数は５０Ｈｚとした。測定で得られた反発力の値（ｍＮ／２５ｍｍ）をループスティフネスの値とした。 (17) Loop stiffness of packaging material The loop stiffness of the packaging material produced in (9) above was measured. A strip of film with a width of 25 mm and 110 mm was cut out so that the longitudinal direction of the strip of film coincided with the direction of the measurement target. The cut out strip-shaped film was set in a loop stiffness tester manufactured by Toyo Seiki Seisakusho Co., Ltd., and the repulsive force was measured. The measurement frequency was 50Hz. The value of the repulsive force (mN/25 mm) obtained in the measurement was taken as the value of loop stiffness.
　以下に本実施例及び比較例で使用する基材フィルムを記す。なお、実施例１～１１、及び比較例１～８で使用し、表６に示した。 The base film used in the present examples and comparative examples is described below. The materials used in Examples 1 to 11 and Comparative Examples 1 to 8 are shown in Table 6.
［基材フィルムの作製］
　ポリオレフィン基材フィルムＯＰＰ－１～５の作製で使用したポリプロピレン系樹脂原料の詳細、フィルム製膜条件、原料配合比率を表１～４に示す。 [Preparation of base film]
Details of the polypropylene resin raw materials used in the production of polyolefin base films OPP-1 to 5, film forming conditions, and raw material blending ratios are shown in Tables 1 to 4.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
（ＯＰＰ－１）
　基材層（Ａ）には、表１に示すＭｎ＝８１，０００、Ｍｗ＝３２０，０００、ＭＦＲ＝２．２ｇ／１０分、メソペンタッド分率［ｍｍｍｍ］＝９９．２％であるプロピレン単独重合体（住友化学（株）製、ＰＰ「ＦＳ２０１２」：共重合モノマー量は０ｍｏｌ％；以下「ＰＰ－２」と略する）を３０質量％、Ｍｎ＝６５，０００、Ｍｗ＝２４０，０００、ＭＦＲ＝７．５ｇ／１０分、メソペンタッド分率［ｍｍｍｍ］＝９８．９％であるプロピレン単独重合体（住友化学（株）製　ＰＰ「ＦＬＸ８０Ｅ４」：共重合モノマー量は０ｍｏｌ％；以下「ＰＰ－３」と略する）を７０質量％の割合で配合したものを使用した。
　また、表面層（Ｂ）には、Ｍｎ＝５５，０００、Ｍｗ＝３００，０００、ＭＦＲ＝５．６ｇ／１０分、であるプロピレン重合体（日本ポリプロ（株）製ノバテック（登録商標）ＰＰ「ＦＬ４」：「ＰＰ－５」と略する）を２４．８質量％、Ｍｎ＝５９，０００、Ｍｗ＝３１０，０００、ＭＦＲ＝３．２ｇ／１０分、であるプロピレン重合体（（株）プライムポリマー製プライムポリプロ「Ｆ―３００ＳＰ」：「ＰＰ－６」と略する）を７２．２質量％、表２に示すマスターバッチＡを３．０質量％の割合で配合したものを使用した。
　基材層（Ａ）は４５ｍｍ押出機、表面層（Ｂ）は２５ｍｍ押出機、表面層（Ｃ）（表面層（Ｂ）と同じ組成）は２０ｍｍ押出機を用いて、それぞれ原料樹脂を２５０℃で溶融し、Ｔダイからシート状に共押し出しし、４０℃の冷却ロールに表面層（Ｂ）が接触するよう冷却固化した後、１２５℃縦方向（ＭＤ）に４．５倍に延伸した。次いでテンター内で、フィルム幅方向（ＴＤ）両端をクリップで挟み、１７４℃で予熱後、１５８℃で幅方向（ＴＤ）に８．２倍に延伸し、幅方向（ＴＤ）に６．７％緩和させながら、１７５℃で熱固定した。このときの製膜条件を製膜条件ａとした。
　こうして、表面層（Ｂ）／基材層（Ａ）／表面層（Ｃ）の構成の二軸配向ポリプロピレンフィルムを得た。
　二軸配向ポリプロピレンフィルムの表面層（Ｂ）の表面を、ソフタル・コロナ・アンド・プラズマＧｍｂＨ社製のコロナ処理機を用いて、印加電流値：０．７５Ａの条件で、コロナ処理を施した後、ワインダーで巻き取った。得られたフィルムの厚みは２０μｍ（表面層（Ｂ）／基材層（Ａ）／表面層（Ｃ）の厚みが１．０μｍ／１８．０μｍ／１．０μｍ）であった。本構成の詳細を表４に示す。 (OPP-1)
The base material layer (A) contains propylene single weight having Mn=81,000, Mw=320,000, MFR=2.2 g/10 min, and mesopentad fraction [mmmm]=99.2% as shown in Table 1. Combined (manufactured by Sumitomo Chemical Co., Ltd., PP "FS2012": copolymerization monomer amount is 0 mol%; hereinafter abbreviated as "PP-2") is 30% by mass, Mn = 65,000, Mw = 240,000, MFR = 7.5 g/10 min, mesopentad fraction [mmmm] = 98.9% propylene homopolymer (PP "FLX80E4" manufactured by Sumitomo Chemical Co., Ltd.: copolymerization monomer amount is 0 mol%; hereinafter "PP-3"'') was used in a proportion of 70% by mass.
In addition, the surface layer (B) is made of propylene polymer (Novatec (registered trademark) PP manufactured by Nippon Polypro Co., Ltd.) with Mn = 55,000, Mw = 300,000, MFR = 5.6 g/10 min. FL4": abbreviated as "PP-5") is 24.8% by mass, Mn = 59,000, Mw = 310,000, MFR = 3.2 g/10 min. Propylene polymer (Prime Co., Ltd.) A mixture of 72.2% by mass of polymer prime polypro "F-300SP" (abbreviated as "PP-6") and 3.0% by mass of masterbatch A shown in Table 2 was used.
The base layer (A) was prepared using a 45 mm extruder, the surface layer (B) was prepared using a 25 mm extruder, and the surface layer (C) (same composition as the surface layer (B)) was prepared using a 20 mm extruder, and the raw resins were heated at 250°C. It was melted and coextruded into a sheet form from a T-die, cooled and solidified so that the surface layer (B) was in contact with a cooling roll at 40°C, and then stretched 4.5 times in the machine direction (MD) at 125°C. Next, in a tenter, both ends of the film in the width direction (TD) are held between clips, and after preheating at 174°C, it is stretched to 8.2 times in the width direction (TD) at 158°C, and 6.7% in the width direction (TD). It was heat-set at 175° C. while being relaxed. The film forming conditions at this time were defined as film forming conditions a.
In this way, a biaxially oriented polypropylene film having the structure of surface layer (B)/base layer (A)/surface layer (C) was obtained.
After corona treatment was applied to the surface of the surface layer (B) of the biaxially oriented polypropylene film using a corona treatment machine manufactured by Softal Corona & Plasma GmbH at an applied current value of 0.75A. , rolled up with a winder. The thickness of the obtained film was 20 μm (thickness of surface layer (B)/base layer (A)/surface layer (C) was 1.0 μm/18.0 μm/1.0 μm). Details of this configuration are shown in Table 4.
（ＯＰＰ－２）
　基材層（Ａ）に、表１に示すＭｎ＝５６，０００、Ｍｗ＝３１０，０００、ＭＦＲ＝２．５ｇ／１０分、メソペンタッド分率［ｍｍｍｍ］＝９４．８％であるプロピレン単独重合体（日本ポリプロ（株）製　ＰＰ「ＦＬ２０３Ｄ」：共重合モノマー量は０ｍｏｌ％；以下「ＰＰ－１」と略する）を１００質量％使用し、表面層（Ｂ）には、ＰＰ－１を９５．２質量％、マスターバッチＢを４．８質量％の割合で配合し、表面層（Ｃ）にはＰＰ－１を９３．６質量％、マスターバッチＢを６．４質量％の割合で配合し、また表３のｂの条件で製膜した以外はＯＰＰ１と同じ条件とし、２０μｍの二軸配向ポリプロピレンフィルムを得た。本構成の詳細を表４に示す。 (OPP-2)
For the base material layer (A), a propylene homopolymer having Mn = 56,000, Mw = 310,000, MFR = 2.5 g/10 min, and mesopentad fraction [mmmm] = 94.8% shown in Table 1 was used. (PP "FL203D" manufactured by Nippon Polypro Co., Ltd.: Copolymerization monomer amount is 0 mol%; hereinafter abbreviated as "PP-1") was used at 100% by mass, and the surface layer (B) contained 95% of PP-1. .2% by mass, masterbatch B is blended at a ratio of 4.8% by mass, and the surface layer (C) is blended with 93.6% by mass of PP-1 and 6.4% by mass of masterbatch B. A 20 μm biaxially oriented polypropylene film was obtained under the same conditions as OPP1 except that the film was formed under the conditions b in Table 3. Details of this configuration are shown in Table 4.
（ＯＰＰ－３）
　基材層（Ａ）には、表１に示すポリプロピレン単独重合体ＰＰ－２を２７．０質量％、表１に示すポリプロピレン単独重合体ＰＰ－３を７０．０質量％、エチレン単独重合体（ＰＥ－１）（Ｂｒａｓｋｅｍ社製「ＳＬＨ２１８」、ＭＦＲ：２．３ｇ／１０分、融点：１２６℃、バイオベース度：８４％、密度：０．９１６ｇ／ｃｍ３）を３質量％の割合で混合した以外はＯＰＰ１と同じ条件とし、２０μｍの二軸配向ポリプロピレンフィルムを得た。本構成の詳細を表４に示す。 (OPP-3)
The base material layer (A) contained 27.0% by mass of polypropylene homopolymer PP-2 shown in Table 1, 70.0% by mass of polypropylene homopolymer PP-3 shown in Table 1, and ethylene homopolymer ( PE-1) (“SLH218” manufactured by Braskem, MFR: 2.3 g/10 min, melting point: 126°C, biobased degree: 84%, density: 0.916 g/cm 3 ) at a ratio of 3% by mass. Except for this, the conditions were the same as OPP1, and a 20 μm biaxially oriented polypropylene film was obtained. Details of this configuration are shown in Table 4.
（ＯＰＰ－４）
　表面層（Ｂ）には、ＰＰ－６を９６．０質量％、マスターバッチＡを４．０質量％の割合で配合し、表面層（Ｃ）には表１に示すＭｎ＝８０，０００、Ｍｗ＝２２０，０００、ＭＦＲ＝７．０ｇ／１０分、であるプロピレン－エチレン共重合体（日本ポリプロ（株）製ウィンテック（登録商標）ＰＰ「ＷＦＸ４Ｍ」：「ＰＰ－４」と略する）を５２．０質量％、ＰＰ－６を４５．０質量％、表２に示すマスターバッチＡを質量３．０％の割合で配合したものを使用した以外はＯＰＰ１と同じ条件とし、２０μｍの二軸配向ポリプロピレンフィルムを得た。本構成の詳細を表４に示す。 (OPP-4)
The surface layer (B) contains 96.0% by mass of PP-6 and 4.0% by mass of masterbatch A, and the surface layer (C) contains Mn=80,000 as shown in Table 1. Propylene-ethylene copolymer with Mw = 220,000 and MFR = 7.0 g/10 min (Wintech (registered trademark) PP "WFX4M" manufactured by Japan Polypropylene Co., Ltd.: abbreviated as "PP-4") The conditions were the same as OPP1 except that a mixture of 52.0% by mass of PP-6, 45.0% by mass of PP-6, and 3.0% by mass of masterbatch A shown in Table 2 was used. An axially oriented polypropylene film was obtained. Details of this configuration are shown in Table 4.
（ＯＰＰ－５）
　表面層（Ｂ）には、ＰＰ－６を９６．４質量％、マスターバッチＡを３．６質量％の割合で配合し、表面層（Ｃ）にはＰＰ－６を９４．０質量％、マスターバッチＡを６．０質量％の割合で配合し、延伸条件を表３記載の条件ｃへ変更した以外はＯＰＰ－１と同様の方法で表面層（Ｂ）／基材層（Ａ）／表面層（Ｃ）の構成の二軸配向ポリプロピレン系フィルムを得た。本構成の詳細を表４に示す。 (OPP-5)
The surface layer (B) contains 96.4% by mass of PP-6 and 3.6% by mass of masterbatch A, and the surface layer (C) contains 94.0% by mass of PP-6. The surface layer (B)/base layer (A)/ A biaxially oriented polypropylene film having the structure of the surface layer (C) was obtained. Details of this configuration are shown in Table 4.
（その他の基材フィルム）
　ＮＹ：二軸延伸ポリアミドフィルム（東洋紡（株）製、Ｎ１１００－１５μｍ）
　蒸着ＰＥＴ：厚さ１２μｍの透明蒸着ポリエステルフィルム（東洋紡（株）製「ＶＥ７０７」） (Other base films)
NY: Biaxially stretched polyamide film (manufactured by Toyobo Co., Ltd., N1100-15 μm)
Vapor-deposited PET: 12 μm thick transparent vapor-deposited polyester film (“VE707” manufactured by Toyobo Co., Ltd.)
（被覆層（Ａ））
　以下に本実施例及び比較例で使用する被覆層（Ａ）形成用の塗工液の詳細を記す。なお、実施例１、及び比較例６で使用し、表６に示した。 (Coating layer (A))
Details of the coating liquid for forming the coating layer (A) used in the present examples and comparative examples are described below. In addition, it was used in Example 1 and Comparative Example 6, and is shown in Table 6.
［ポリビニルアルコール樹脂（ａ）］
　精製水９０質量部に、完全けん化ポリビニルアルコール樹脂（日本合成化学工業（株）製、商品名：ＧポリマーＯＫＳ８０４９Ｑ、（けん化度９９．０％以上、平均重合度４５０））、１０質量部を加え、攪拌しながら８０℃に加温し、その後約１時間攪拌させた。その後、常温になるまで冷却し、これにより固形分１０％のほぼ透明なポリビニルアルコール溶液（ＰＶＡ溶液）（ａ）を得た。 [Polyvinyl alcohol resin (a)]
To 90 parts by mass of purified water, 10 parts by mass of fully saponified polyvinyl alcohol resin (manufactured by Nippon Gosei Kagaku Kogyo Co., Ltd., trade name: G Polymer OKS8049Q, (saponification degree of 99.0% or more, average degree of polymerization 450)) was added. The mixture was heated to 80° C. with stirring, and then stirred for about 1 hour. Thereafter, it was cooled to room temperature, thereby obtaining an almost transparent polyvinyl alcohol solution (PVA solution) (a) with a solid content of 10%.
［無機層状化合物分散液（ｂ）］
　無機層状化合物であるモンモリロナイト（商品名：クニピアＦ、クニミネ工業（株）製）５質量部を精製水９５質量部中に攪拌しながら添加しホモジナイザーにて１５００ｒｐｍの設定にて充分に分散した。その後、２３℃にて１日間保温し固形分５％の無機層状化合物分散液（ｂ）を得た。 [Inorganic layered compound dispersion (b)]
5 parts by mass of montmorillonite (trade name: Kunipia F, manufactured by Kunimine Kogyo Co., Ltd.), which is an inorganic layered compound, was added to 95 parts by mass of purified water with stirring, and sufficiently dispersed using a homogenizer at a setting of 1500 rpm. Thereafter, the mixture was kept at 23° C. for one day to obtain an inorganic layered compound dispersion (b) with a solid content of 5%.
［被覆層１（被覆１）に用いる塗工液１］
　下記の配合比率で各材料を混合し、塗布液（被覆層用樹脂組成物）を作製した。
　　イオン交換水　　　　　　　　　　　　　　　　　１５．００質量％
　　イソプロピルアルコール　　　　　　　　　　　　１５．００質量％
　　ポリビニルアルコール樹脂（ａ）　　　　　　　　３０．００質量％
　　無機層状化合物分散液（ｂ）　　　　　　　　　　４０．００質量％ [Coating liquid 1 used for coating layer 1 (coating 1)]
A coating liquid (resin composition for coating layer) was prepared by mixing each material in the following blending ratio.
Ion exchange water 15.00% by mass
Isopropyl alcohol 15.00% by mass
Polyvinyl alcohol resin (a) 30.00% by mass
Inorganic layered compound dispersion (b) 40.00% by mass
［被覆層２（被覆２）に用いる塗工液２］
　下記の配合比率で各材料を混合し、塗布液（被覆層用樹脂組成物）を作製した。
　　イオン交換水　　　　　　　　　　　　　　　　　１５．００質量％
　　イソプロピルアルコール　　　　　　　　　　　　１５．００質量％
　　ポリビニルアルコール樹脂（ａ）　　　　　　　　７０．００質量％ [Coating liquid 2 used for coating layer 2 (coating 2)]
A coating liquid (resin composition for coating layer) was prepared by mixing each material in the following blending ratio.
Ion exchange water 15.00% by mass
Isopropyl alcohol 15.00% by mass
Polyvinyl alcohol resin (a) 70.00% by mass
（フィルムへの塗工液のコート（被覆層の積層））
　上記調製した塗工液をグラビアロールコート法によって、基材フィルムのコロナ処理面上に塗布し、９０℃×４秒で予備乾燥した後、１２０℃×４秒で本乾燥させ、被覆層を得た。この時の被覆層の付着量は０．３０ｇ／ｍ２であった。その後、４０℃２日間（４８時間）の後加熱処理を施した。以上のようにして、被覆層１又は２のいずれかを備えた積層フィルムを作製した。 (Coating of coating liquid on film (lamination of coating layer))
The coating solution prepared above was applied onto the corona-treated surface of the base film by a gravure roll coating method, pre-dried at 90°C for 4 seconds, and then main-dried at 120°C for 4 seconds to obtain a coating layer. Ta. The amount of coating layer deposited at this time was 0.30 g/m 2 . Thereafter, post-heat treatment was performed at 40°C for 2 days (48 hours). As described above, a laminated film having either coating layer 1 or 2 was produced.
（無機薄膜層（Ｂ））
　以下に各実施例及び比較例で使用する無機薄膜層（Ｂ）の作製方法を記す。なお、実施例２～１１、及び比較例１～３、５、８で使用し、表６に示した。
（無機薄膜層１の形成）
　無機薄膜層１（蒸着１）として、基材フィルム又はアンカーコート層上に、二酸化ケイ素と酸化アルミニウムの複合酸化物層を電子ビーム蒸着法で形成した。蒸着源としては、３ｍｍ～５ｍｍ程度の粒子状ＳｉＯ２（純度９９．９％）とＡｌ２Ｏ３（純度９９．９％）とを用いた。このようにして得られたフィルム（無機薄膜層／被覆層含有フィルム）における無機薄膜層（ＳｉＯ２／Ａｌ２Ｏ３複合酸化物層）の膜厚は１３ｎｍであった。またこの複合酸化物層の組成は、ＳｉＯ２／Ａｌ２Ｏ３（質量比）＝７０／３０であった。 (Inorganic thin film layer (B))
The method for producing the inorganic thin film layer (B) used in each Example and Comparative Example is described below. The samples used in Examples 2 to 11 and Comparative Examples 1 to 3, 5, and 8 are shown in Table 6.
(Formation of inorganic thin film layer 1)
As inorganic thin film layer 1 (vapor deposition 1), a composite oxide layer of silicon dioxide and aluminum oxide was formed on the base film or anchor coat layer by electron beam evaporation. Particulate SiO 2 (purity 99.9%) and Al 2 O 3 (purity 99.9%) of about 3 mm to 5 mm were used as vapor deposition sources. The film thickness of the inorganic thin film layer (SiO 2 /Al 2 O 3 composite oxide layer) in the film thus obtained (inorganic thin film layer/coating layer-containing film) was 13 nm. The composition of this composite oxide layer was SiO 2 /Al 2 O 3 (mass ratio) = 70/30.
（無機薄膜層２の形成）
　無機薄膜層２（蒸着２）として、基材フィルム又はアンカーコート層上に酸化ケイ素の蒸着を行った。小型真空蒸着装置（アルバック機工（株）製、ＶＷＲ－４００／ＥＲＨ）を使用して、１０－３Ｐａ以下に減圧した後、該基板の下部よりニラコ製蒸着源Ｂ－１１０にー酸化ケイ素をセットし加熱蒸発させ、フィルム上に厚さ３０ｎｍの酸化ケイ素膜を形成した。 (Formation of inorganic thin film layer 2)
As the inorganic thin film layer 2 (vapor deposition 2), silicon oxide was deposited on the base film or the anchor coat layer. After reducing the pressure to 10 -3 Pa or less using a small vacuum evaporation device (manufactured by ULVAC Kiko Co., Ltd., VWR-400/ERH), silicon oxide was added to the evaporation source B-110 manufactured by Nilaco from the bottom of the substrate. The film was set and heated to evaporate to form a 30 nm thick silicon oxide film on the film.
（無機薄膜層３の形成）
　無機薄膜層３（蒸着３）として、基材フィルム又はアンカーコート層上に金属アルミニウムの蒸着を行った。小型真空蒸着装置（アルバック機工（株）製、ＶＷＲ－４００／ＥＲＨ）を使用して、１０－３Ｐａ以下に減圧した後、該基板の下部よりニラコ製蒸着源ＣＦ－３０５Ｗに純度９９．９％のアルミホイルをセットし、金属アルミニウムを加熱蒸発させ、フィルム上に厚さ３０ｎｍの金属アルミニウム膜を形成した。 (Formation of inorganic thin film layer 3)
As the inorganic thin film layer 3 (vapor deposition 3), metal aluminum was deposited on the base film or the anchor coat layer. After reducing the pressure to 10 -3 Pa or less using a small vacuum evaporation device (manufactured by ULVAC Kiko Co., Ltd., VWR-400/ERH), a 99.9-purity evaporation source CF-305W manufactured by Nilaco was applied from the bottom of the substrate. % aluminum foil was set, and the metal aluminum was heated and evaporated to form a metal aluminum film with a thickness of 30 nm on the film.
（アンカーコート層（Ｃ））
　以下に各実施例及び比較例で使用したアンカーコート層（Ｃ）の作製方法を記す。
［ポリエステル樹脂（ａ）］
　ポリエステル成分として、ポリエステルポリオール（ＤＩＣ社製「ＤＦ－ＣＯＡＴ　ＧＥＣ－００４Ｃ」：固形分３０％）を用いた。 (Anchor coat layer (C))
The method for producing the anchor coat layer (C) used in each Example and Comparative Example is described below.
[Polyester resin (a)]
As the polyester component, polyester polyol ("DF-COAT GEC-004C" manufactured by DIC Corporation: solid content 30%) was used.
［ポリイソシアネート架橋剤（ｂ）］
　ポリイソシアネート成分として、メタキシリレンジイソシアネートのトリメチロールプロパンアダクト体（三井化学（株）製「タケネートＤ－１１０Ｎ」：固形分７５％）を用いた。 [Polyisocyanate crosslinking agent (b)]
As the polyisocyanate component, a trimethylolpropane adduct of metaxylylene diisocyanate ("Takenate D-110N" manufactured by Mitsui Chemicals, Inc.: solid content 75%) was used.
［シランカップリング剤（ｃ）］
　シランカップリング剤として、Ｎ－２－（アミノエチル）－３－アミノプロピルトリメトキシシラン（信越化学工業（株）製「ＫＢＭ－６０３」）を用いた。 [Silane coupling agent (c)]
N-2-(aminoethyl)-3-aminopropyltrimethoxysilane (“KBM-603” manufactured by Shin-Etsu Chemical Co., Ltd.) was used as a silane coupling agent.
［ウレタン樹脂（ｄ）］
　ウレタン樹脂として、ポリエステルウレタン樹脂のディスパージョン（三井化学（株）製「タケラック（登録商標）ＷＰＢ３４１」；固形分３０％）を用いた。 [Urethane resin (d)]
As the urethane resin, a polyester urethane resin dispersion ("Takelac (registered trademark) WPB341" manufactured by Mitsui Chemicals, Inc.; solid content: 30%) was used.
［アンカーコート層－１用の塗工液１］
　シランカップリング剤（ｃ）をアセトンに溶解した溶液（１５質量％）及びイソシアネート（ｂ）を下記比率で混合させ、１０分間マグネチックスターラーを用いて撹拌した。得られた調合液をメチルエチルケトン及び１－メトキシ－２－プロパノール（以下ＰＧＭ）で希釈し、さらにポリエステル樹脂（ａ）を添加し、目的の塗工液１を得た。混合比を以下に示す。
　　ポリエステル樹脂（ａ）　　　　　　　　　　　　　１０．６２質量％
　　イソシアネート（ｂ）　　　　　　　　　　　　　　　４．０７質量％
　　シランカップリング剤（ｃ）※アセトン希釈液　　　　１．７３質量％
　　メチルエチルケトン　　　　　　　　　　　　　　　６９．５５質量％
　　ＰＧＭ　　　　　　　　　　　　　　　　　　　　　１４．０３質量％ [Coating liquid 1 for anchor coat layer-1]
A solution of silane coupling agent (c) dissolved in acetone (15% by mass) and isocyanate (b) were mixed at the following ratio and stirred for 10 minutes using a magnetic stirrer. The obtained liquid mixture was diluted with methyl ethyl ketone and 1-methoxy-2-propanol (hereinafter referred to as PGM), and polyester resin (a) was further added to obtain the desired coating liquid 1. The mixing ratio is shown below.
Polyester resin (a) 10.62% by mass
Isocyanate (b) 4.07% by mass
Silane coupling agent (c) *Acetone diluted solution 1.73% by mass
Methyl ethyl ketone 69.55% by mass
PGM 14.03% by mass
　［アンカーコート層－２用の塗工液２］
　下記の塗剤を混合し、塗工液２を作製した。
　　水　　　　　　　　　　　　　　　　　　　　　　４６．００質量％
　　イソプロパノール　　　　　　　　　　　　　　　３０．００質量％
　　ウレタン樹脂（ｄ）　　　　　　　　　　　　　　２４．００質量％ [Coating liquid 2 for anchor coat layer-2]
Coating liquid 2 was prepared by mixing the following coating agents.
Water 46.00% by mass
Isopropanol 30.00% by mass
Urethane resin (d) 24.00% by mass
（フィルムへの塗工液のコート（アンカーコート層の積層））
　前記塗工液１又は２を用いて、グラビアロールコート法によって、基材フィルムのコロナ処理面上に塗布し、９５℃×４秒で予備乾燥した後、１１５℃×４秒で本乾燥させ、アンカーコート層を得た。この時のアンカーコート層（ＡＣ－１～３）の付着量は０．４０ｇ／ｍ２であった。その後、４０℃×４日間（９６時間）の後加熱処理を施して、目的の積層フィルムを得た。 (Coating of coating liquid on film (lamination of anchor coat layer))
Using the coating liquid 1 or 2, apply it on the corona-treated surface of the base film by gravure roll coating method, pre-dry at 95 ° C. x 4 seconds, and then main dry at 115 ° C. x 4 seconds, An anchor coat layer was obtained. At this time, the adhesion amount of the anchor coat layers (AC-1 to AC-3) was 0.40 g/m 2 . Thereafter, a post-heat treatment was performed at 40° C. for 4 days (96 hours) to obtain the desired laminated film.
（保護層（Ｄ））
［保護層（Ｄ）に用いる塗工液１］
　テトラエトキシシランを０．０２ｍｏｌ／Ｌの塩酸で加水分解した溶液をけん化度９９％、重合度２４００のポリビニルアルコール樹脂（ＰＶＡ）の５質量％水溶液に、質量比でＳｉＯ２／ＰＶＡ＝６０／４０となる割合で加え、ガスバリア性保護層溶液（塗工液１）とした。 (Protective layer (D))
[Coating liquid 1 used for protective layer (D)]
A solution obtained by hydrolyzing tetraethoxysilane with 0.02 mol/L hydrochloric acid was added to a 5% by mass aqueous solution of polyvinyl alcohol resin (PVA) with a degree of saponification of 99% and a degree of polymerization of 2400, with a mass ratio of SiO 2 /PVA = 60/40. A gas barrier protective layer solution (coating solution 1) was prepared.
（フィルムへの塗工液のコート（保護層の積層））
　前述の塗工液１を用いて、グラビアロールコート法によって、基材フィルムの無機薄膜層（Ｂ）上に塗布し、１２０℃のドライオーブンで１０秒間乾燥させ、保護層１を得た。この時の保護層の付着量は０．３０ｇ／ｍ２であった。その後、４０℃２日間（４８時間）の後加熱処理を施した。以上のようにして、保護層を備えた積層フィルムを作製した。 (Coating of coating liquid on film (lamination of protective layer))
The coating solution 1 described above was applied onto the inorganic thin film layer (B) of the base film by a gravure roll coating method, and dried in a dry oven at 120° C. for 10 seconds to obtain a protective layer 1. The amount of the protective layer deposited at this time was 0.30 g/m 2 . Thereafter, post-heat treatment was performed at 40°C for 2 days (48 hours). In the manner described above, a laminated film provided with a protective layer was produced.
［ヒートシール性樹脂フィルムＣＰＰ１の作製］
　２３０℃、２．１６ｋｇにおけるＭＦＲ３．２ｇ／１０ｍｉｎ、融点１４２℃のプロピレン－エチレンランダム共重合体（住友化学（株）製、ＷＦ５７７ＰＧ）１００質量部に対し、１９０℃、２．１６ｋｇにおけるＭＦＲ３．６ｇ／１０ｍｉｎのエチレン－ブテン共重合エラストマー樹脂（三井化学（株）製、タフマーＡ－４０７０Ｓ）８．３質量部、１９０℃、２．１６ｋｇにおけるＭＦＲ３．０ｇ／１０ｍｉｎのプロピレン－ブテン共重合エラストマー樹脂（三井化学（株）製、タフマーＸＭ－７０７０Ｓ）２．８質量部を調製した。前記調整物を１００質量部として有機系潤滑剤としてエルカ酸アミド３２０ｐｐｍと、無機アンチブロッキング剤として平均粒径４μｍのシリカをその含有量が樹脂組成物中に２４００ｐｐｍとなるように添加した。これらの原料を均一になるように混合し、ポリオレフィン系樹脂フィルムを製造するための混合原料を得た。得られた混合材料を、ラミネート層、中間層、ヒートシール層の混合原料としてそれぞれ使用した。 [Preparation of heat-sealable resin film CPP1]
MFR 3.2 g/10 min at 230° C. and 2.16 kg, MFR 3.6 g at 190° C. and 2.16 kg for 100 parts by mass of propylene-ethylene random copolymer (manufactured by Sumitomo Chemical Co., Ltd., WF577PG) with a melting point of 142° C. /10min ethylene-butene copolymer elastomer resin (manufactured by Mitsui Chemicals, Inc., TAFMER A-4070S) 8.3 parts by mass, MFR 3.0g/10min at 190°C and 2.16kg propylene-butene copolymer elastomer resin ( 2.8 parts by mass of Tafmer XM-7070S (manufactured by Mitsui Chemicals, Inc.) was prepared. Using 100 parts by mass of the preparation, 320 ppm of erucic acid amide as an organic lubricant and silica with an average particle size of 4 μm as an inorganic anti-blocking agent were added to the resin composition so that the content thereof was 2400 ppm. These raw materials were mixed uniformly to obtain a mixed raw material for producing a polyolefin resin film. The obtained mixed material was used as a mixed raw material for a laminate layer, an intermediate layer, and a heat seal layer, respectively.
（溶融押出）
　中間層に用いる混合原料をスクリュー直径９０ｍｍの３ステージ型単軸押出し機で、ラミネート層用及びヒートシール層用の混合原料をそれぞれ直径４５ｍｍ及び直径６５ｍｍの３ステージ型単軸押出し機を使用し、ラミネート層／中間層／ヒートシール層の順になるよう導入し、巾８００ｍｍでプレランドを２段階にし、かつ溶融樹脂の流れが均一になるように段差部分の形状を曲線状としてダイス内の流れが均一になるように設計したＴスロット型ダイに導入し、ダイスの出口温度を２３０℃で押出した。ラミネート層／中間層／ヒートシール層の厚み比率はそれぞれ２５％／５０％／２５％とした。ラミネート層、中間層、ヒートシール層のいずれにも同様に前記混合原料を投入した。 (melt extrusion)
A three-stage single-screw extruder with a screw diameter of 90 mm was used for the mixed raw material used for the intermediate layer, and a three-stage single-screw extruder with a diameter of 45 mm and a diameter of 65 mm was used for the mixed raw materials for the laminate layer and the heat seal layer, respectively. The laminate layer/intermediate layer/heat seal layer are introduced in this order, and the preland is made into two stages with a width of 800 mm.The shape of the stepped portion is curved to ensure a uniform flow of the molten resin. The sample was introduced into a T-slot type die designed to have a temperature of 230° C. at the outlet of the die. The thickness ratios of the laminate layer/intermediate layer/heat seal layer were 25%/50%/25%, respectively. The mixed raw materials were similarly introduced into each of the laminate layer, intermediate layer, and heat seal layer.
（冷却）
　ダイスから出てきた溶融樹脂シートを２１℃の冷却ロールで冷却し、厚みが２７０μｍよりなる未延伸のポリオレフィン系樹脂フィルムを得た。冷却ロールでの冷却に際しては、エアーノズルで冷却ロール上のフィルムの両端を固定し、エアーナイフで溶融樹脂シートの全幅を冷却ロールへ押さえつけ、同時に真空チャンバーを作用させ溶融樹脂シートと冷却ロールの間への空気の巻き込みを防止した。エアーノズルは、両端ともフィルム進行方向に直列に設置した。ダイス周りはシートで囲い、溶融樹脂シートに風が当たらないようした。 (cooling)
The molten resin sheet coming out of the die was cooled with a cooling roll at 21° C. to obtain an unstretched polyolefin resin film having a thickness of 270 μm. When cooling on a cooling roll, both ends of the film on the cooling roll are fixed with air nozzles, the entire width of the molten resin sheet is pressed onto the cooling roll with an air knife, and at the same time a vacuum chamber is applied to create a space between the molten resin sheet and the cooling roll. Prevents air from getting into the The air nozzles were installed in series at both ends in the film advancing direction. The area around the dice was surrounded by a sheet to prevent wind from hitting the molten resin sheet.
（予熱）
　未延伸シートを加温したロール群に導き、シートとロールを接触させることによってシートを予熱した。予熱ロールの温度は１０５℃とした。複数のロールを使用し、フィルムの両面を予熱した。 (preheat)
The unstretched sheet was introduced into a group of heated rolls, and the sheet was preheated by bringing the sheet into contact with the rolls. The temperature of the preheating roll was 105°C. Multiple rolls were used and both sides of the film were preheated.
（縦延伸）
　前記未延伸シートを縦延伸機に導き、ロール速度差により、４．５倍に延伸し、厚みを６０μｍとした。延伸ロールの温度は１０５℃とした。 (longitudinal stretching)
The unstretched sheet was introduced into a longitudinal stretching machine, and was stretched 4.5 times by a roll speed difference to a thickness of 60 μm. The temperature of the stretching rolls was 105°C.
（アニール処理）
　アニーリングロールを使用し５％の緩和率を与えながら１２０℃で熱処理を施した。複数のロールを使用し、フィルムの両面を熱処理した。 (annealing treatment)
Heat treatment was performed at 120° C. using an annealing roll while giving a relaxation rate of 5%. Multiple rolls were used to heat treat both sides of the film.
（コロナ処理）
　フィルムの片面（ラミネート面）にコロナ処理を施した。 (Corona treatment)
Corona treatment was applied to one side (laminated side) of the film.
（巻き取り）
　製膜速度は２０ｍ／分で実施した。製膜したフィルムは耳部分をトリミングし、ロール状態にして巻き取った。フィルムの片面（ラミネート面）の濡れ張力は４２ｍＮ／ｍであった。 (Take-up)
The film forming speed was 20 m/min. The formed film was trimmed at the edges and wound into a roll. The wetting tension on one side of the film (laminated side) was 42 mN/m.
　表５に示す方法で同様にＣＰＰ２～６のヒートシール性樹脂フィルムを作製した。なお、表５中、プロピレンエチレンブロックは、三井化学（株）製のタフマーＰ０４８０を使用し、エチレンプロピレン共重合体エラストマーは、住友化学（株）製のＥＰ３７２１を用いた。 Heat-sealable resin films of CPPs 2 to 6 were similarly produced using the method shown in Table 5. In Table 5, Tafmer P0480 manufactured by Mitsui Chemicals Co., Ltd. was used as the propylene ethylene block, and EP3721 manufactured by Sumitomo Chemical Co., Ltd. was used as the ethylene propylene copolymer elastomer.
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
　以上のようにして、各フィルムの上に被覆層（Ａ）、アンカーコート層（Ｃ）、無機薄膜層（Ｂ）、又は保護層（Ｄ）を備え、さらにヒートシール性樹脂フィルムを有する包装材料を作製した。 As described above, the packaging material is provided with a coating layer (A), an anchor coat layer (C), an inorganic thin film layer (B), or a protective layer (D) on each film, and further has a heat-sealable resin film. was created.
　各実施例、比較例では、各包装体を使用して、前述の接着剤を用いたドライラミネート法にて貼り合わせて表６に記載の構成の包装材料とした。なお、表６中、実施例９、比較例７は、基材フィルムを２枚使用しており、それぞれの上段が１枚目の基材フィルム、下段が２枚目の基材フィルムを示す。 In each Example and Comparative Example, each package was used and bonded together by the dry lamination method using the above-mentioned adhesive to obtain a packaging material having the configuration shown in Table 6. In Table 6, Example 9 and Comparative Example 7 use two base films, with the upper row representing the first base film and the lower row representing the second base film.
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000006
　また、得られた包装体について、各種評価を実施した。結果を表７に示す。なお、表７中、実施例７中の「デラミ」は、デラミネーションを示す。 Furthermore, various evaluations were carried out on the obtained packaging. The results are shown in Table 7. In Table 7, "Delami" in Example 7 indicates delamination.
Figure JPOXMLDOC01-appb-T000007
Figure JPOXMLDOC01-appb-T000007
　本発明により、要求される性能に合わせた所定のガスバリア層を基材フィルム上に積層した積層フィルムとすることでガスバリア性能を大きく向上させ、さらに前記積層フィルムの加熱伸び率を制御することで各種加工や殺菌処理に対する耐熱性を確保でき、最終的にヒートシール性樹脂フィルムとして直進カット性に優れ腰感の強い樹脂層を前述の基材フィルムと貼り合わせることで、環境にやさしくかつ利便性も高い包装材料を提供できる。しかも、本発明の包装材料は加工工程が少なくかつ容易に製造できるので、経済性と生産安定性の両方に優れており、均質な特性のガスバリア性包装体を提供することができる。 The present invention significantly improves gas barrier performance by forming a laminate film in which a specified gas barrier layer tailored to the required performance is laminated onto a base film, and furthermore, by controlling the thermal elongation rate of the laminate film, heat resistance to various processing and sterilization treatments can be ensured. Finally, by laminating a resin layer with excellent straight-line cutting properties and strong stiffness to the aforementioned base film as a heat-sealable resin film, it is possible to provide a packaging material that is both environmentally friendly and highly convenient. Moreover, since the packaging material of the present invention requires few processing steps and can be easily manufactured, it is excellent in both economy and production stability, and it is possible to provide a gas barrier package with uniform characteristics.

Claims (12)

  1. 　ポリオレフィン系樹脂を構成成分とする基材フィルムを少なくとも１枚と、ヒートシール性樹脂フィルムとを有する包装材料であって、
    　前記基材フィルムのうち少なくとも１枚はガスバリア層を有する積層基材フィルムであって、
    　前記包装材料から剥離した基材フィルムの少なくとも１枚が、熱機械分析装置により測定した１３０℃における加熱伸び率が、ＭＤ方向、ＴＤ方向のいずれも６％以下であり、
    　前記包装材料の直進カット性が、ＭＤ方向又はＴＤ方向において１０ｍｍ以下、かつ、ループスティフネスの値が１４０ｍＮ／２５ｍｍ以上であり、
    　２３℃×６５％ＲＨ環境下における酸素透過度が６０ｍｌ／ｍ２・ｄ・ＭＰａ以下であることを特徴とする包装材料。     A packaging material comprising at least one base film containing a polyolefin resin as a constituent component and a heat-sealable resin film,
    At least one of the base films is a laminated base film having a gas barrier layer,
    At least one of the base films peeled from the packaging material has a heating elongation rate at 130°C measured by a thermomechanical analyzer of 6% or less in both the MD direction and the TD direction,
    The straight cutting property of the packaging material is 10 mm or less in the MD direction or the TD direction, and the loop stiffness value is 140 mN/25 mm or more,
    A packaging material characterized by an oxygen permeability of 60 ml/m 2 ·d·MPa or less under a 23° C. x 65% RH environment.
  2. 　前記ヒートシール性樹脂フィルムは、プロピレン－αオレフィンランダム共重合体を含み、さらにエチレン－プロピレン共重合エラストマー、エチレン－ブテン共重合エラストマー、プロピレン－ブテン共重合エラストマーから選ばれる少なくとも１つの成分を含むことを特徴とする請求項１に記載の包装材料。 The heat-sealable resin film contains a propylene-α olefin random copolymer, and further contains at least one component selected from an ethylene-propylene copolymer elastomer, an ethylene-butene copolymer elastomer, and a propylene-butene copolymer elastomer. The packaging material according to claim 1, characterized in that:
  3. 　前記ガスバリア層が、アルミニウム、酸化アルミニウム、酸化ケイ素、及び酸化ケイ素と酸化アルミニウムの複合酸化物からなる群より選択されてなる材料から形成される無機薄膜層であることを特徴とする請求項１に記載の包装材料。 2. The gas barrier layer is an inorganic thin film layer formed from a material selected from the group consisting of aluminum, aluminum oxide, silicon oxide, and a composite oxide of silicon oxide and aluminum oxide. Packaging materials listed.
  4. 　前記ガスバリア層が、ポリビニルアルコール樹脂、ポリエステル樹脂、及びポリウレタン樹脂からなる群より選択されてなる樹脂を構成成分として含む被覆層であることを特徴とする請求項１に記載の包装材料。 The packaging material according to claim 1, wherein the gas barrier layer is a coating layer containing as a constituent component a resin selected from the group consisting of polyvinyl alcohol resin, polyester resin, and polyurethane resin.
  5. 　前記基材フィルムとガスバリア層との間にアンカーコート層が積層されることを特徴とする請求項１に記載の包装材料。 The packaging material according to claim 1, wherein an anchor coat layer is laminated between the base film and the gas barrier layer.
  6. 　前記ガスバリア層の上に保護層が積層されることを特徴とする請求項１に記載の包装材料。 The packaging material according to claim 1, wherein a protective layer is laminated on the gas barrier layer.
  7. 　前記基材フィルムを２枚以上用いることを特徴とする請求項１に記載の包装材料。 The packaging material according to claim 1, characterized in that two or more of the base films are used.
  8. 　前記基材フィルムを構成するポリオレフィン樹脂のうち、植物由来のポリエチレン樹脂を１質量％以上２５質量％以下含むことを特徴とする請求項１に記載の包装材料。 The packaging material according to claim 1, characterized in that the polyolefin resin constituting the base film contains 1% by mass or more and 25% by mass or less of a plant-derived polyethylene resin.
  9. 　ボイル又はレトルト用に使用されることを特徴とする請求項１に記載の包装材料。 The packaging material according to claim 1, which is used for boiling or retorting.
  10. 　電子レンジ加熱用に使用されることを特徴とする請求項１に記載の包装材料。 The packaging material according to claim 1, which is used for heating in a microwave oven.
  11. 　請求項１～１０のいずれかに記載の包装材料を用いて構成される包装袋。 A packaging bag constructed using the packaging material according to any one of claims 1 to 10.
  12. 　請求項１～１０のいずれかに記載の包装材料、又は請求項１１に記載の包装袋を使用して被包装物が包装されてなる包装体。 A package obtained by packaging an object using the packaging material according to any one of claims 1 to 10 or the packaging bag according to claim 11.
PCT/JP2023/033180 2022-09-13 2023-09-12 Packaging material WO2024058167A1 (en)

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JPH0655710A (en) * 1992-08-11 1994-03-01 Toppan Printing Co Ltd Laminated packaging material
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JP2001277408A (en) * 2000-03-31 2001-10-09 Toppan Printing Co Ltd Resin laminated film excellent in stiffness strength and impact resistance
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CN104354418A (en) * 2014-11-24 2015-02-18 天津市天塑特种母料有限公司 BOPP (Biaxially-oriented Polypropylene) composite film with oxygen barrier modified agent
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WO2021199637A1 (en) * 2020-03-31 2021-10-07 大日本印刷株式会社 Laminate, pouch, and lid member
JP2021169193A (en) * 2020-04-17 2021-10-28 東レフィルム加工株式会社 Vapor deposition film and laminate including the same
US20220112018A1 (en) * 2019-02-04 2022-04-14 Amcor Flexibles North America, Inc. Directional tear packaging film
WO2022118680A1 (en) * 2020-12-04 2022-06-09 東洋紡株式会社 Biaxially oriented polypropylene resin film, and packaging using same
JP2023013250A (en) * 2021-07-15 2023-01-26 東洋紡株式会社 Laminated film for inorganic thin film layer formation
WO2023127594A1 (en) * 2021-12-28 2023-07-06 東洋紡株式会社 Packaging material

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01159232A (en) * 1987-10-05 1989-06-22 Mobil Oil Corp Biaxial oriented multilayer barrier film and manufacture thereof
JPH0655710A (en) * 1992-08-11 1994-03-01 Toppan Printing Co Ltd Laminated packaging material
JPH10329262A (en) * 1997-04-03 1998-12-15 Toray Ind Inc Gas barrier biaxially oriented polypropylene film with excellent transparency, laminated film, and its manufacture
JP2001277408A (en) * 2000-03-31 2001-10-09 Toppan Printing Co Ltd Resin laminated film excellent in stiffness strength and impact resistance
JP2003025518A (en) * 2001-07-17 2003-01-29 Yupo Corp Multilayered resin stretched film
CN104354418A (en) * 2014-11-24 2015-02-18 天津市天塑特种母料有限公司 BOPP (Biaxially-oriented Polypropylene) composite film with oxygen barrier modified agent
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JP2021169193A (en) * 2020-04-17 2021-10-28 東レフィルム加工株式会社 Vapor deposition film and laminate including the same
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