WO2024058167A1 - Matériau d'emballage - Google Patents

Matériau d'emballage 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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Prior art keywords
film
layer
packaging material
resin
heat
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PCT/JP2023/033180
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English (en)
Japanese (ja)
Inventor
敦史 山崎
稚登 戸松
充裕 柏
徹 今井
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東洋紡株式会社
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Publication of WO2024058167A1 publication Critical patent/WO2024058167A1/fr

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    • 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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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Laminated Bodies (AREA)

Abstract

La présente invention vise à proposer un matériau d'emballage qui est un stratifié de résines ayant un faible impact sur l'environnement et qui possède les propriétés de rigidité, de découpage et de perméabilité au gaz souhaitées pour un matériau d'emballage. À cet effet, la présente invention concerne un matériau d'emballage qui comprend : au moins un film de matériau de base qui comprend une résine de polyoléfine en tant qu'élément constitutif ; et un film de résine thermoscellable. Le matériau d'emballage est caractérisé en ce qu'au moins l'un des films de matériau de base est un film de matériau de base stratifié qui a une couche de perméabilité au gaz, l'allongement thermique d'au moins un film de matériau de base décollé du matériau d'emballage tel que mesuré à 130 °C à l'aide d'un dispositif d'analyse thermomécanique ne dépasse pas 6 % à la fois dans le sens MD et dans le sens TD, le découpage droit du matériau d'emballage ne dépasse pas 10 mm dans le sens MD ou le sens TD, la valeur de la rigidité de boucle du matériau d'emballage est d'au moins 140 mN/25 mm, et le coefficient de transmission de l'oxygène du matériau d'emballage à 23 °C et 65 % HR ne dépasse pas 60 ml/m2∙d∙MPa.
PCT/JP2023/033180 2022-09-13 2023-09-12 Matériau d'emballage WO2024058167A1 (fr)

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Publication number Priority date Publication date Assignee Title
JPH01159232A (ja) * 1987-10-05 1989-06-22 Mobil Oil Corp 二軸延伸多層バリヤーフィルムとその製造方法
JPH0655710A (ja) * 1992-08-11 1994-03-01 Toppan Printing Co Ltd 積層包装材料
JPH10329262A (ja) * 1997-04-03 1998-12-15 Toray Ind Inc 透明性に優れたガスバリア性二軸配向ポリプロピレンフィルムと積層フィルムおよびその製造方法
JP2001277408A (ja) * 2000-03-31 2001-10-09 Toppan Printing Co Ltd 腰強度と耐衝撃性に優れた樹脂積層フィルム
JP2003025518A (ja) * 2001-07-17 2003-01-29 Yupo Corp 多層樹脂延伸フィルム
CN104354418A (zh) * 2014-11-24 2015-02-18 天津市天塑特种母料有限公司 一种具有隔氧性改性制剂的bopp复合薄膜
US20180126695A1 (en) * 2015-04-10 2018-05-10 Borealis Ag Monoaxially oriented multilayer cast film
JP2018167487A (ja) * 2017-03-30 2018-11-01 三井化学東セロ株式会社 食品用包装フィルムおよび食品用包装体
WO2021199637A1 (fr) * 2020-03-31 2021-10-07 大日本印刷株式会社 Stratifié, sachet, et matériau de couvercle
JP2021169193A (ja) * 2020-04-17 2021-10-28 東レフィルム加工株式会社 蒸着フィルムおよびそれを用いた積層体
US20220112018A1 (en) * 2019-02-04 2022-04-14 Amcor Flexibles North America, Inc. Directional tear packaging film
WO2022118680A1 (fr) * 2020-12-04 2022-06-09 東洋紡株式会社 Film de résine à base de polypropylène à orientation biaxiale, et emballage mettant en œuvre celui-ci
JP2023013250A (ja) * 2021-07-15 2023-01-26 東洋紡株式会社 無機薄膜層形成用の積層フィルム
WO2023127594A1 (fr) * 2021-12-28 2023-07-06 東洋紡株式会社 Matériau d'emballage

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01159232A (ja) * 1987-10-05 1989-06-22 Mobil Oil Corp 二軸延伸多層バリヤーフィルムとその製造方法
JPH0655710A (ja) * 1992-08-11 1994-03-01 Toppan Printing Co Ltd 積層包装材料
JPH10329262A (ja) * 1997-04-03 1998-12-15 Toray Ind Inc 透明性に優れたガスバリア性二軸配向ポリプロピレンフィルムと積層フィルムおよびその製造方法
JP2001277408A (ja) * 2000-03-31 2001-10-09 Toppan Printing Co Ltd 腰強度と耐衝撃性に優れた樹脂積層フィルム
JP2003025518A (ja) * 2001-07-17 2003-01-29 Yupo Corp 多層樹脂延伸フィルム
CN104354418A (zh) * 2014-11-24 2015-02-18 天津市天塑特种母料有限公司 一种具有隔氧性改性制剂的bopp复合薄膜
US20180126695A1 (en) * 2015-04-10 2018-05-10 Borealis Ag Monoaxially oriented multilayer cast film
JP2018167487A (ja) * 2017-03-30 2018-11-01 三井化学東セロ株式会社 食品用包装フィルムおよび食品用包装体
US20220112018A1 (en) * 2019-02-04 2022-04-14 Amcor Flexibles North America, Inc. Directional tear packaging film
WO2021199637A1 (fr) * 2020-03-31 2021-10-07 大日本印刷株式会社 Stratifié, sachet, et matériau de couvercle
JP2021169193A (ja) * 2020-04-17 2021-10-28 東レフィルム加工株式会社 蒸着フィルムおよびそれを用いた積層体
WO2022118680A1 (fr) * 2020-12-04 2022-06-09 東洋紡株式会社 Film de résine à base de polypropylène à orientation biaxiale, et emballage mettant en œuvre celui-ci
JP2023013250A (ja) * 2021-07-15 2023-01-26 東洋紡株式会社 無機薄膜層形成用の積層フィルム
WO2023127594A1 (fr) * 2021-12-28 2023-07-06 東洋紡株式会社 Matériau d'emballage

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