Title of Invention: Method for manufacturing package, film for packaging material, laminated film and packaging material comprising the same
Technical field
[0001]
The present disclosure relates to a method for manufacturing a package, a film for packaging material, and a laminated film and packaging material having the same.
Background technology
[0002]
Conventionally, packaging materials have been developed for many products such as food, beverages, pharmaceuticals, and chemicals according to their contents. In particular, as packaging materials for contents such as liquids, semi-solids or gels, plastic materials are used which are excellent in water resistance, oil resistance, gas barrier properties, lightness, flexibility, design and the like.
[0003]
For the purpose of providing higher functionality as packaging materials for contents such as liquids, semi-solids, or gel substances, packaging materials having the following configurations, for example, have been proposed.
・Plastic laminate in which multiple types of plastic substrates are laminated
・Composite laminate of paper, metal foil, inorganic material, etc. and plastic substrate
・Composites in which a plastic substrate is treated with a functional composition
[0004]
As one of the above-mentioned high functions, for example, a function that suppresses the adhesion of contents to the inner surface of the packaging material, that is, the function of suppressing the remaining contents is required. More specifically, lid materials for containers such as yogurt, jelly, and syrup; packaging materials for retort food such as porridge, soup, curry, and pasta sauce; and liquid, semi-solid, and gel substances such as chemicals and pharmaceuticals. Such film materials for storage containers are required to have excellent liquid repellency on the inner surface of which the contents are less likely to adhere and easily slide off. This prevents the content from adhering to the inner surface, resulting in waste due to the inability to use up all the content, the occurrence of stains due to the adherence of the content, and the time and effort required to discharge the content. It's for.
[0005]
In response to these demands, Patent Document 1, for example, discloses a packaging container for storing cooked foods, which has an inner surface made of resin and on which an oil film made of a highly viscous oily liquid that satisfies predetermined conditions is formed. Proposed. Further, Patent Document 2 discloses a heat seal layer containing polyolefin particles having an average particle size D50 of 10 to 50 μm and a melting point of 100 to 180° C., and having a surface roughness Ra of 1.00 to 7.00 μm. A packaging sheet is proposed.
prior art documents
patent literature
[0006]
Patent Document 1: JP 2019-18878 A
Patent Document 2: International Publication No. 2018/003978
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0007]
By the way, a package that contains curry, pasta sauce, etc. with a packaging material is subjected to retort treatment at a temperature of, for example, about 120°C. In the invention described in Patent Document 1, it is assumed that an oil film is formed by spraying a high-viscosity oily liquid (see paragraph [0032] of Patent Document 1). This oil film has insufficient durability against heat treatment such as retort treatment. In addition, it is necessary to select the type of high-viscosity oily liquid to be used according to the contents, and it is considered necessary to prepare different formulations. On the other hand, the packaging sheet described in Patent Literature 2 is insufficient in slipping properties of oil-in-water dispersion type contents (for example, curry). This is presumed to be due to the relatively rough surface of the heat seal layer (surface roughness Ra: 1.00 to 7.00 μm).
[0008]
The present disclosure provides a method for manufacturing a package that is excellent in sliding down of oil-in-water dispersion type contents. The present disclosure also provides films for packaging materials and laminated films and packaging materials comprising the same. In the present disclosure, the oil-in-water dispersion type content means a content containing water and lipid, and the content of water is higher than the content of lipid. "Fat" is a concept that includes oil that is liquid at 20°C (normal temperature) and fat that is solid at 20°C. Hereinafter, the oil contained in the oil-in-water dispersion type content and the fat that becomes liquid by the heat treatment applied to the package according to the present disclosure are collectively referred to as “oil” or “oil”. called.
Means to solve problems
[0009]
One aspect of the present disclosure provides a method of manufacturing a package. This manufacturing method includes the following steps.
(A) A packaging material comprising an innermost layer containing a resin composition containing a polypropylene resin and a filler dispersed in the resin composition, wherein the ratio Y between the thickness X μm of the innermost layer and the average particle diameter Y μm of the filler is Y μm. A step of preparing a packaging material where /X is 0.02 to 3.5
(B) A step of producing a package having the above-mentioned packaging material and an oil-in-water dispersion type content housed in a sealed state by the above-mentioned packaging material.
(C) a step of heat-treating the package to allow the innermost layer to absorb the oil contained in the contents;
[0010]
When the ratio Y/X of the thickness X μm of the innermost layer and the average particle diameter Y μm of the filler is 0.02 to 3.5, the innermost surface of the packaging material has moderate unevenness (for example, arithmetic mean roughness Sa: 0.3 μm or more and less than 1.0 μm). In step (C), the innermost layer absorbs oil, or absorbs oil and swells to increase the lipophilicity of the innermost surface, and between the innermost surface and the contents, an oil film derived from the contents is formed. easier to form. Due to the synergistic effect of the unevenness of the innermost surface and the improvement of lipophilicity due to oil absorption, the oil film is stably formed between the innermost surface and the contents (see FIG. 2(b)). By interposing an oil film between the innermost surface and the contents, direct contact of the contents with the innermost surface is suppressed, and excellent slipping property of the contents including water is obtained. In other words, the oil film derived from the oil-in-water dispersion type content contributes to the development of excellent slideability. A polypropylene resin usually contains a crystalline part and an amorphous part, and the amorphous part has higher oil absorption than the crystalline part. In addition, polypropylene resin has heat-sealing properties. The innermost layer comprising polypropylene resin may serve as a sealant film.
[0011]
One aspect of the present disclosure provides a packaging film. This packaging film has a first resin layer containing a resin composition containing a polypropylene resin and a filler dispersed in the resin composition, and the average thickness of the first resin layer is X μm and the filler is The ratio Y/X of the particle diameter Y μm is 0.02 to 3.5. This packaging film is suitably applied to the method for manufacturing the package. Polypropylene resin has heat-sealing properties. A packaging film comprising a first resin layer containing a polypropylene resin may be used as a sealant film.
[0012]
The arithmetic mean roughness Sa of the first surface of the first resin layer (the innermost surface of the packaging material film) is, for example, 0.3 μm or more from the viewpoint of stable oil film formation and excellent slipping property of the contents. less than 0.0 μm. From a similar point of view, the first surface of the first resin layer (the innermost surface of the packaging material film) has a protruding peak volume Vmp of, for example, 0.08 to 0.3 μm 3 /μm 2 .
[0013]
The packaging material film may have a single layer structure consisting of only the first resin layer, or may have a multilayer structure including the first resin layer and the second resin layer. The second resin layer is provided, for example, on the second surface (surface opposite to the first surface) of the first resin layer.
[0014]
The first resin layer may further contain at least one additive selected from the group consisting of the following resin materials (i) to (vii) from the viewpoint of exhibiting even more excellent slipping properties. The amorphous part (rubber component) contained in these resin materials has the property of absorbing oil, and promotes the formation of a stable and uniform oil film in the step (C) and thereafter, thereby allowing the contents to slide down. It is possible to further improve the property.
(i) Block copolymer of polypropylene and polyethylene
(ii) a block copolymer of polyethylene and ethylene-butylene
(iii) a block copolymer of polyethylene and ethylene-octene
(iv) Ethylene-based elastomer
(v) propylene elastomer
(vi) butene elastomer
(vii) Reactor TPO
[0015]
From the viewpoint of compatibility with the polypropylene resin contained in the first resin layer, the first resin layer preferably contains at least (v) a propylene-based elastomer among the above additives. At least one of the softening point and the melting point of the additive is preferably 130° C. or lower from the viewpoint of exhibiting even more excellent slipping properties after the heat treatment. The softening point of the additive may be a value measured using a thermomechanical analyzer (TMA), or may be a manufacturer's catalog value. The melting point of the additive may be a value measured using a differential scanning calorimeter (DSC), or may be a manufacturer's catalog value.
[0016]
The present disclosure provides a laminated film comprising the film for packaging material and a packaging material made of this laminated film. A laminated film according to the present disclosure includes a substrate and the packaging film provided on the substrate, and the first resin layer is disposed on at least one outermost surface. The packaging material according to the present disclosure is suitably used for a package that contains an oil-in-water dispersion type content in a sealed state and that is subjected to heat treatment.
Effect of the invention
[0017]
According to the present disclosure, there is provided a method for manufacturing an oil-in-water dispersion type package that is excellent in sliding down properties. Further, according to the present disclosure, a film for packaging material and a laminated film and packaging material comprising the same are provided.
Brief description of the drawing
[0018]
1] Fig. 1 is a cross-sectional view schematically showing an embodiment of a packaging material according to the present disclosure. [Fig.
2] Figs. 2(a) to 2(c) are schematic diagrams for explaining the mechanism by which the first resin layer develops sliding property for the contents of the oil-in-water dispersion type. [Fig.
3] FIG. 3 is a schematic diagram showing Wenzel's model. [FIG.
4] Fig. 4 is a cross-sectional view schematically showing another embodiment of the packaging material according to the present disclosure. [Fig.
5] Figs. 5(a) to 5(e) are schematic diagrams for explaining a method for evaluating slipping property of the inner surface of a packaging material. [Fig.
MODE FOR CARRYING OUT THE INVENTION
[0019]
Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant explanations are omitted. Also, the dimensional ratios in the drawings are not limited to the illustrated ratios.
[0020]

FIG. 1 is a cross-sectional view schematically showing one embodiment of the packaging material according to this embodiment. A packaging material 10 shown in FIG. 1 includes a first resin layer 1 containing polypropylene resin as a base material, a second resin layer 2 , an adhesive layer 3 and a substrate 5 . The first resin layer 1 is arranged on the outermost surface of the packaging material 10, and when a package (for example, a retort pouch) is produced using the packaging material 10, the surface F1 of the first resin layer 1 (first surface) is the innermost surface of the package. In this embodiment, the first resin layer 1 and the second resin layer 2 constitute a packaging film. The second resin layer 2 is provided on the surface F2 (second surface) opposite to the surface F1 of the first resin layer 1 .
[0021]
The packaging material 10 is used to contain the contents of the oil-in-water dispersion type. The lipid content of the oil-in-water dispersion type content is, for example, 0.1% by mass or more and less than 50% by mass, and may be 0.5 to 40% by mass or 1 to 20% by mass. The oil-in-water dispersion type content in the present embodiment includes a composition having a water content higher than the oil content (water-rich) and oil dispersed therein. Specific examples of oil-in-water dispersion type include curry, hayashi, pasta sauce (eg, meat sauce), and pet food. The content of lipids contained in curry is, for example, about 0.2 to 15% by mass, and the amount of water contained in curry is, for example, about 70 to 90% by mass.
[0022]
The mechanism by which the first resin layer 1 develops the ability to slide down the contents of the oil-in-water dispersion type will be described with reference to FIGS. 2(a) to 2(c). As shown in FIG. 2(a), the surface F1 of the first resin layer 1 has unevenness caused by the filler 1b. Moreover, the polypropylene resin, which is the main component of the first resin layer 1, has the property of absorbing oil and swelling under the temperature conditions of retort treatment and boiling treatment. For this reason, when the content C of the oil-in-water dispersion type is subjected to heat treatment while being in contact with the surface F1 of the first resin layer 1, as schematically indicated by an arrow in FIG. A part of the oil content C 2 O contained in the substance C is absorbed by the first resin layer 1 . This makes the surface The lipophilicity of F1 is improved. An oil film F 2 O is stably formed between the surface F1 and the content C due to the synergistic effect of the unevenness of the surface F1 and the improvement in lipophilicity due to oil absorption. The presence of the oil film FO between the surface F1 and the content C suppresses the direct contact of the content C with the surface F1 and makes the content C slippery with the oil film FO as an interface. . Therefore, as shown in FIG. 2(c), the content C slides down from the surface F1 simply by tilting the surface F1.
[0023]
FIG. 3 is a cross-sectional view showing Wenzel's model applied when the roughness of the surface F1 is relatively small. In this model, the oil droplet D 0 dropped onto the surface F1 enters the recesses of the surface F1, and the entire surface F1 is wet. According to the studies of the present inventors, the mechanism by which the oil film F 2 O is likely to be formed on the surface F1 can be explained by Wenzel's model. On the other hand, when the roughness of the surface F1 is relatively large, the height of the unevenness is likely to be higher than the height of the oil film. According to the studies of the present inventors, if the surface roughness of the surface F1 is too large, the contents are likely to be caught on the irregularities, which hinders the contents from sliding down (see Comparative Examples 2 and 3).
[0024]
The first resin layer 1, the second resin layer 2, the base material 5, and the adhesive layer 3 that constitute the packaging material 10 will be described below.
(First resin layer)
The first resin layer 1 is subjected to heat treatment (for example, retort treatment and boiling treatment) while being in contact with the oil-in-water dispersion type content, so that the oil-in-water dispersion type content slides down. layer. The first resin layer 1 contains a resin composition 1a containing polypropylene resin and fillers 1b dispersed in the resin composition 1a. The content of the polypropylene resin in the resin composition 1a is, for example, 75% by mass or more, and may be 80% by mass or more, or 90% by mass or more. The resin composition 1a may consist essentially of a polypropylene resin.
[0025]
Examples of polypropylene resins include homopolypropylene, block polypropylene, random polypropylene and modified polypropylene. The block polypropylene here is different from (C1) a block copolymer of polypropylene and polyethylene (compatibilizer) described later, and generally EPR (rubber component) and polyethylene are dispersed in the homopolypropylene at the polymerization stage. It has a structure that When block polypropylene and random polypropylene are used in combination as polypropylene resin, the mass ratio of block polypropylene and random polypropylene (block polypropylene/random polypropylene) is preferably 20/80 to 80/20, preferably 40/60. ~60/40 is more preferred.
[0026]
Modified polypropylene is obtained by graft-modifying polypropylene with, for example, an unsaturated carboxylic acid derivative component derived from an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, an unsaturated carboxylic acid ester, or the like. Modified polypropylene such as hydroxyl-modified polypropylene and acrylic-modified polypropylene can also be used as the polypropylene resin. Examples of the α-olefin component used to obtain the propylene-based copolymer include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 4-methyl-1-pentene, and the like. can.
[0027]
The first resin layer 1 preferably further contains at least one additive selected from the group consisting of the following resin materials (i) to (vii) from the viewpoint of exhibiting even more excellent slipping properties. Reactor TPO (thermoplastic polyester) is a kind of olefinic thermoplastic elastomer (TPO). It is composed of a rubber component.
(i) Block copolymer of polypropylene and polyethylene
(ii) a block copolymer of polyethylene and ethylene-butylene
(iii) a block copolymer of polyethylene and ethylene-octene
(iv) Ethylene-based elastomer
(v) propylene elastomer
(vi) butene elastomer
(vii) Reactor TPO
[0028]
The amount of the resin components (i) to (vii) added (the total amount when adding a plurality of resin components) is, for example, 30 parts by mass or less, preferably 1 to 100 parts by mass with respect to 100 parts by mass of the polypropylene resin. It is 25 parts by mass, more preferably 2 to 20 parts by mass, and still more preferably 3 to 15 parts by mass. The amorphous portion (rubber component) contained in the resin components (i) to (vii) has the property of absorbing oil. Therefore, these resin components promote the formation of a stable and uniform oil film F 2 O (see FIG. 2(b)), thereby further improving the slideability of the contents C.
[0029]
From the viewpoint of compatibility with the polypropylene resin contained in the first resin layer 1, the first resin layer 1 contains at least (v) propylene among the resin components (additives) of (i) to (vii). It preferably contains a system elastomer. At least one of the softening point and the melting point of the resin component is preferably 130° C. or lower, more preferably 120° C. or lower, from the viewpoint of exhibiting even more excellent slipping properties after heat treatment.
[0030]
Examples of the filler 1b include organic fillers such as olefin fillers and acrylic fillers, inorganic fillers such as silica fillers, and porous fillers. Examples of olefin fillers include Miperon (registered trademark) series manufactured by Mitsui Chemicals, Inc. and CS series manufactured by Sumitomo Chemical Co., Ltd. Examples of acrylic fillers include MX series manufactured by Soken Chemical Co., Ltd. Examples of silica fillers include the Smooth Master series manufactured by Dainichiseika Kogyo Co., Ltd., the Silophobic series manufactured by Fuji Silysia Chemical Co., Ltd., and the Admafine SO series manufactured by Admatechs.
[0031]
The average particle size (Yμm) of the filler 1b can be obtained as follows.

(1) A filler is dispersed in a dispersion medium. The dispersion medium is, for example, water or an organic solvent, and an appropriate one is selected according to the type of filler.
(2) Using a laser diffraction particle size distribution analyzer (product name: MT3300EXII, manufactured by Microtrack Bell), the average particle size of the filler is calculated by a laser diffraction/scattering method.

If the laser diffraction particle size distribution measurement is not suitable or difficult, the average particle size of the filler may be determined using an optical microscope such as a scanning electron microscope (SEM) or a laser microscope. For any given particle within the field of view of the microscope, the length of the longest diameter and the shortest diameter of the particle is measured, and the sum divided by 2 is taken as the particle diameter. Particle diameters are measured and calculated for a plurality of particles, and the average thereof is regarded as the average particle diameter. The number of the arbitrary particles is preferably 10 or more.
[0032]
The average particle size (Y μm) of the filler 1b is, for example, 1 to 100 μm, preferably 2 to 80 μm, more preferably 3 to 50 μm, still more preferably 5 to 30 μm. When the average particle size of the filler 1b is within the above range, the surface F1 of the first resin layer 1 can be provided with appropriate unevenness. The content of the filler 1b in the first resin layer 1 is, for example, 0.5 to 10 parts by mass, preferably 1 to 8 parts by mass, and more preferably 2 to 8 parts by mass with respect to 100 parts by mass of the polypropylene resin. part by mass. When the content of the filler 1b is within the above range, the surface F1 of the first resin layer 1 can be provided with appropriate unevenness.
[0033]
The thickness (X μm) of the first resin layer 1 is a value obtained as follows.
(1) First, a structure is prepared by fixing the packaging material 10 with an embedding resin (acrylic resin).
(2) A sample for cross-sectional observation is cut out from the structure using a microtome.
(3) The cross section of the cut sample for cross section observation is observed with a microscope (product name: VHX-1000, manufactured by Keyence Corporation).
(4) Measure the thickness at three locations where the filler 1b does not exist along the thickness direction of the first resin layer 1, and calculate the average value of the thicknesses at these three locations as the thickness of the first resin layer 1. (X μm).
[0034]
The thickness (X μm) of the first resin layer 1 is, for example, 2 to 100 μm, preferably 4 to 70 μm, more preferably 6 to 50 μm, still more preferably 8 to 30 μm. When the thickness of the first resin layer 1 is within the above range, both the slideability of the contents and the heat sealability can be achieved at a high level. The first resin layer 1 contains a heat-sealable polypropylene resin and can also serve as a sealant film. The heat-sealability is, for example, a property that enables heat-sealing under the conditions of 100 to 200° C., 0.1 to 0.3 MPa, and 1 to 3 seconds.
[0035]
The ratio Y/X between the thickness X μm of the first resin layer 1 and the average particle diameter Y μm of the filler 1b is 0.02 to 3.5. When the ratio Y/X is within the above range, when the first resin layer 1 is deposited, moderate unevenness is formed on the surface F1. When the ratio Y/X is less than 0.02, unevenness on the surface F1 is not sufficiently formed, resulting in insufficient expression of slipping properties. On the other hand, if the ratio Y/X exceeds 3.5, excessive unevenness is formed on the surface F1, and this unevenness may hinder the sliding down of the contents. The ratio Y/X is preferably 0.05 or more, more preferably 0.1 or more, and still more preferably 0.3 or more. The ratio Y/X is preferably 3.0 or less, more preferably 2.5 or less, still more preferably 1.8 or less, and may be 1.5 or less or 1.2 or less.
[0036]
The arithmetic mean roughness Sa of the surface F1 of the first resin layer 1 is preferably 0.3 μm or more and less than 1.0 μm, more preferably 0.4 μm or more and less than 1.0 μm, from the viewpoint of exhibiting excellent sliding properties. and more preferably 0.5 μm or more and 0.98 μm or less. The arithmetic mean roughness Sa of the surface F1 can be adjusted by, for example, the blending amount and average particle size of the filler 1b, and the film forming conditions (thickness, temperature, etc.) of the first resin layer 1. The value of "arithmetic mean roughness Sa" used herein means a value measured under the following conditions using a laser microscope (trade name "OLS-4000", manufactured by Olympus Corporation).
・Magnification of the objective lens: 50 times
・Cutoff: None
[0037]
The protruding peak volume Vmp of the surface F1 of the first resin layer 1 is preferably 0.08 to 0.3 μm 3 /μm 2 , more preferably 0.08 to 0, from the viewpoint of exhibiting excellent sliding properties. 0.25 μm 3 /μm 2 , more preferably 0.1 to 0.2 μm 3 /μm 2 . The protruding peak volume Vmp of the surface F1 can be adjusted by, for example, the blending amount and average particle size of the filler 1b and the film forming conditions (thickness, temperature, etc.) of the first resin layer 1 . The value of "protruding peak volume Vmp" used herein means a value measured under the following conditions using a laser microscope (trade name "OLS-4000", manufactured by Olympus Corporation).
・Ratio of load area that separates the core and protruding peaks: 10%
[0038]
(Second resin layer)
The second resin layer 2 is a layer provided between the first resin layer 1 and the substrate 5. By further including the second resin layer 2 in the packaging material 10, the functions of the packaging material 10 (heat sealability, heat resistance, impact resistance, oxygen/water vapor barrier properties, etc.) can be improved. For example, the second resin layer 2 preferably contains a thermoplastic resin from the viewpoint of improving heat sealability. Specific examples of thermoplastic resins include polyolefin resins, ethylene-α,β-unsaturated carboxylic acid copolymers or esterified products or ionic crosslinked products thereof, ethylene-vinyl acetate copolymers or saponified products thereof, polyvinyl acetate or saponified products thereof. compound, polycarbonate resin, thermoplastic polyester resin, ABS resin, polyacetal resin, polyamide resin, polyphenylene oxide resin , polyimide resin, polyurethane resin, polylactic acid resin, furan resin, and silicone resin. These thermoplastic resins can be used singly or in combination of two or more.
[0039]
The thickness of the second resin layer 2 can be appropriately set according to the use of the packaging material 10. The thickness of the second resin layer 2 is, for example, 1 to 300 μm, preferably 2 to 200 μm, more preferably 5 to 150 μm, still more preferably 10 to 100 μm.
[0040]
(Base material)
The base material 5 is not particularly limited as long as it serves as a support and has durability against heat treatment, and examples thereof include resin films and metal foils. Examples of resin films include polyolefins (e.g., polyethylene (PE), polypropylene (PP), etc.), acid-modified polyolefins, polyesters (e.g., polyethylene terephthalate (PET), etc.), polyamides (PA), polyvinyl chloride (PVC), cellulose acetate, A film containing at least one type of cellophane resin is included. This film may be a stretched film or a non-stretched film. Examples of metal foil include aluminum foil and nickel foil. The base material 5 may be a laminate of a plurality of base materials made of different materials, or may include a coat layer or a metal deposition layer.
[0041]
The thickness of the base material 5 can be appropriately set according to the use of the packaging material 10. The thickness of the substrate 5 is, for example, 1-500 μm, and may be 10-100 μm.
[0042]
(adhesive layer)
The adhesive layer 3 adheres the packaging film (the laminate of the first resin layer 1 and the second resin layer 2 ) and the base material 5 . Examples of adhesives include polyurethane resins obtained by reacting a main agent such as polyester polyol, polyether polyol, acrylic polyol, and carbonate polyol with a di- or higher functional isocyanate compound.
[0043]
For the purpose of promoting adhesion, the adhesive layer 3 may contain a carbodiimide compound, an oxazoline compound, an epoxy compound, a phosphorus compound, a silane coupling agent, etc. in the polyurethane resin described above. Depending on the performance required for the adhesive layer 3, the polyurethane resin described above may be blended with various other additives and stabilizers.
[0044]
The thickness of the adhesive layer 3 is, for example, 1 to 10 μm, and may be 3 to 7 μm, from the viewpoint of obtaining desired adhesive strength, followability, workability, and the like. Various polyols may be used singly or in combination of two or more. Examples of methods for bonding the base material 5 and the packaging film include lamination with an adhesive and lamination with heat treatment.
[0045]
(Lamination method with adhesive)
As a lamination method using an adhesive, various known lamination methods such as dry lamination, wet lamination, and non-solvent lamination can be used. Adhesives used in these lamination methods include the following.
[0046]
(Lamination method by heat treatment)
The methods of laminating by heat treatment are roughly classified into the following methods.
(1) A method of extruding and laminating an adhesive resin between a previously formed liquid-repellent film and the substrate 5 .
(2) A method of co-extrusion of the resin layer and the adhesive resin constituting the liquid-repellent film and lamination with the substrate 5 .
(3) A method of bonding the laminated base material obtained by the above method (1) or (2) by further heating and pressurizing with a hot roll.
(4) A method of storing the laminated base material obtained by the above method (1) or (2) in a high-temperature atmosphere, or passing it through a drying/baking furnace in a high-temperature atmosphere.
[0047]
Adhesive resins used in lamination methods using heat treatment include acid-modified polyolefins. In the above method, the substrate 5 and the liquid-repellent film are laminated by extrusion lamination. It is also possible to laminate a liquid-repellent film by heat treatment after coating and forming thereon.
[0048]
It is also possible to provide an adhesive primer (anchor coat) on the substrate 5, and the material thereof includes polyester, polyurethane, polyallylamine, polyethyleneimine, polybutadiene, ethylene-vinyl acetate copolymer, A chlorine-vinyl acetate system or the like can be used. The adhesive primer may optionally contain various curing agents and additives that can be used as adhesives.
[0049]

The manufacturing method of the package according to this embodiment includes the following steps.
(A) Step of preparing packaging material 10
(B) A step of producing a package P having a packaging material 10 and an oil-in-water dispersion type content C housed in a sealed state by the packaging material 10
(C) A step of heat-treating (for example, retorting or boiling) the package P to absorb the oil contained in the contents C into the first resin layer 1.
[0050]
According to the production method of the present embodiment, an oil film F 2 O is formed between the surface F1 and the content C due to the synergistic effect of the unevenness of the surface F1 of the first resin layer 1 and the improvement in lipophilicity due to oil absorption. It is stably formed (see FIG. 2(b)). By interposing an oil film between the surface F1 and the content C, it is possible to suppress the direct contact of the content C with the surface F1, and to obtain an excellent sliding property of the content C containing water ( See FIG. 2(c)).
[0051]
Although the embodiments of the present disclosure have been described in detail above, the present invention is not limited to the above embodiments. For example, in the above embodiment, the packaging film composed of the first and second resin layers 1 and 2 was exemplified, but the packaging film is a single layer composed only of the first resin layer 1. may A packaging material 20 shown in FIG. 4 includes a first resin layer 1 (film for packaging material), an adhesive layer 3 and a substrate 5 .
Example
[0052]
The present disclosure will be described in more detail below based on examples and comparative examples, but the present invention is not limited to the following examples.
[0053]
"I prepared the following materials."

・A1: Random PP resin (propylene-ethylene random copolymer, trade name "Prime Polypro F744NP", manufactured by Prime Polymer Co., Ltd.)
・A2: Block PP resin (propylene-ethylene block copolymer, trade name "Prime Polypro BC5FA", manufactured by Prime Polymer Co., Ltd.)
・A3: Block PP resin (propylene-ethylene block copolymer, trade name "Prime Polypro BC3HF", manufactured by Prime Polymer Co., Ltd.)
[0054]

・ B1: Olefin filler (average particle size: 2 μm, trade name “CS18”, manufactured by Sumitomo Chemical Co., Ltd.)
・ B2: Olefin filler (average particle size: 10 μm, trade name “Miperon PM-1010”, b-PP masterbatch, manufactured by Mitsui Chemicals, Inc.)
・ B3: Olefin filler (average particle size: 30 μm, trade name “Mipelon XM-220”, manufactured by Mitsui Chemicals, Inc.)
・ B4: Olefin filler (average particle size: 60 μm, trade name “Mipelon XM-330”, manufactured by Mitsui Chemicals, Inc.)
・B5: Silica filler (average particle size: 2 μm, trade name “Smooth Master S PE2000”, manufactured by Dainichiseika Kogyo Co., Ltd.)
・ B6: Silica filler (average particle size: 8 μm, trade name “Silophobic 4004”, manufactured by Fuji Silysia Chemical Co., Ltd.)
・ B7: Acrylic filler (average particle size: 30 μm, trade name “MX-3000”, manufactured by Soken Chemical Co., Ltd.)
The average particle size of the filler can be obtained by measuring the longitudinal and lateral lengths of any 10 particles and averaging the values ​​obtained by dividing the sum by 2.
[0055]

・C1: block copolymer of polypropylene and polyethylene
・C2: block copolymer of polyethylene and ethylene-butylene
・C3: block copolymer of polyethylene and ethylene-octene
・ C4: PE elastomer (trade name “Tafmer A4085S”, manufactured by Mitsui Chemicals, Inc.)
・ C5a: PP elastomer (trade name “Tafmer PN3560”, manufactured by Mitsui Chemicals, Inc.)
・ C5b: PP elastomer (trade name “Tafmer PN2060”, manufactured by Mitsui Chemicals, Inc.)
・ C5c: PP elastomer (trade name “Tafmer PN2070”, manufactured by Mitsui Chemicals, Inc.)
・ C5d: PP elastomer (trade name “Tafmer XM7070”, manufactured by Mitsui Chemicals, Inc.)
・ C6: PB-based elastomer (trade name “Tafmer BL4000”, manufactured by Mitsui Chemicals, Inc.)
・C7: Reactor TPO (trade name “Cataloy C200F”, manufactured by Basell)
[0056]

(Examples 1 to 42 and Comparative Examples 1 to 5)
Using a co-extruder, a two-layer packaging film (sealant film) comprising a first resin layer having the composition shown in Tables 1 to 8 and a second resin layer made of A3 (block PP resin). was made. The obtained film and a PET film having a thickness of 38 μm as a base material (trade name “EMBRET”, manufactured by Unitika Ltd.) were dry-laminated using a polyurethane adhesive (manufactured by Mitsui Chemicals, Inc.). After aging at 50° C. for 5 days, a packaging material was obtained. In the examples and comparative examples except for comparative example 3, the films were formed so that the total thickness of the first resin layer and the second resin layer was 60 μm. In Comparative Example 3, the thickness of the first resin layer was 150 μm, and the thickness of the second resin layer was 50 μm.
[0057]

The arithmetic mean roughness Sa of the first resin layer was measured under the following conditions using a laser microscope (trade name "OLS-4000", manufactured by Olympus Corporation).
・Magnification of the objective lens: 50 times
・Cutoff: None
[0058]

The protruding peak volume Vmp of the first resin layer was measured under the following conditions using a laser microscope (trade name "OLS-4000", manufactured by Olympus Corporation).
・Ratio of load area that separates the core and protruding peaks: 10%
[0059]

(Residual liquid evaluation after retort treatment)
The packaging materials obtained in Examples and Comparative Examples were evaluated for sliding property after retort treatment by the method shown in Figs. 5(a) to 5(e). First, two pieces of packaging material 30 were prepared by cutting the packaging material into a size of 150 mm long and 138 mm wide. The two packaging materials 30 were stacked with the first resin layers on the inside, and three sides were sealed using a heat sealer. As shown in FIG. 5(a), a pouch was produced in which seal portions 30a were formed on three sides and one side was open. The heat sealing of the three sides was performed under the conditions of 190° C., 0.03 MPa, and 2 seconds, and the width of the seal portion 30a was 10 mm. Next, 180 g of curry as content C (trade name “Bon Curry Gold Medium Spicy”, fat content 7.0 g/180 g, manufactured by Otsuka Foods Co., Ltd.) was injected from the opening of the pouch (Fig. 5(b)). reference). The opening (remaining one side) was then sealed using a heat sealer. As shown in FIG. 5(c), a package P in which a sealed portion 30b was formed on the remaining one side, four sides were sealed, and the content C was accommodated was produced. The heat sealing of the opening was performed under the conditions of 190° C., 0.03 MPa, and 2 seconds, and the width of the seal portion 30b was 10 mm.
[0060]
After putting the package P into a high-temperature and high-pressure cooking and sterilization device (manufactured by Hitachi Capital Co., Ltd.), retort processing was performed with high-temperature steam. The retort treatment was performed under the following conditions.
・ Pressure: 0.2 MPa
・Temperature 121℃
・Processing time: 30 minutes
After the retort treatment, the package P was boiled in hot water at 100°C for 5 minutes. After these heat treatments, the top of the package P was cut to form a spout (see FIG. 5(d)). Next, the pouch was turned upside down and held for 10 seconds with the spout tilted at 45° from the horizontal surface, the content C was discharged into the container 50, and the discharged amount was weighed by the scale 60 (Fig. 5 (e) see). From the weighed discharge amount, the residual liquid amount (%) was determined by the following formula.
　Residual liquid amount (%) = {(180-discharge amount)/180} x 100
The measurement was performed 3 times, and the residual liquid was evaluated according to the following evaluation criteria from the average residual liquid amount of the 3 times. Tables 1 to 8 show the residual liquid amount and the residual liquid evaluation results.
A: The average residual liquid amount is less than 6.5%
B: The average residual liquid amount is 6.5% or more and less than 8.0%
C: Average residual liquid amount is 8.0% or more and less than 10.0%
D: Average residual liquid amount is 10.0% or more
[0061]
(Appearance evaluation after retort treatment)
In the evaluation of the remaining liquid, the behavior of the curry discharged from the pouch was visually observed, and the external appearance was evaluated according to the following evaluation criteria. Results are shown in Tables 1-8.
A: It can be seen that it slides down cleanly, and there is almost no adhesion to the film.
B: A state of sliding down is observed, and there is little adhesion to the film.
C: It looks like it is sliding down, but it is attached to the film.
D: I can't see it sliding down.
[0062]
[table 1]

[0063]
[Table 2]

[0064]
[Table 3]

[0065]
[Table 4]

[0066]
[Table 5]

[0067]
[Table 6]

[0068]
[Table 7]

[0069]
[Table 8]

Industrial applicability
[0070]
According to the present disclosure, there is provided a method for manufacturing an oil-in-water dispersion type package that is excellent in sliding down properties. Further, according to the present disclosure, a film for packaging material and a laminated film and packaging material comprising the same are provided.
Code explanation
[0071]
DESCRIPTION OF SYMBOLS 1... First resin layer (innermost layer), 1a... Resin composition, 1b... Filler, 2... Second resin layer, 3... Adhesive layer, 5... Base material, 10, 20... Packaging material (laminated film ), C... content, CO... oil, F1... surface (first surface, innermost surface), F2... surface (second surface), FO... oil film, P... package
The scope of the claims
[Claim 1]
(A) A packaging material comprising an innermost layer containing a resin composition containing a polypropylene resin and a filler dispersed in the resin composition, wherein the thickness of the innermost layer is X μm and the average particle diameter of the filler is Y μm. A step of preparing a packaging material having a ratio Y/X of 0.02 to 3.5;
(B) a step of producing a package having the packaging material and an oil-in-water dispersion type content housed in a sealed state by the packaging material;
(C) heat-treating the package to allow the innermost layer to absorb the oil contained in the contents;
A method of manufacturing a package containing
[Claim 2]
The method for manufacturing a package according to claim 1, wherein the lipid content of the oil-in-water dispersion type content is 0.1% by mass or more and less than 50% by mass.
[Claim 3]
A first resin layer containing a resin composition containing a polypropylene resin and a filler dispersed in the resin composition,
A packaging film, wherein the ratio Y/X between the thickness X μm of the first resin layer and the average particle diameter Y μm of the filler is 0.02 to 3.5.
[Claim 4]
4. The method according to claim 3, wherein the first surface of the first resin layer and the surface constituting the innermost surface of the packaging film has an arithmetic mean roughness Sa of 0.3 μm or more and less than 1.0 μm. Film for packaging materials.
[Claim 5]
Claim 3, wherein the first surface of the first resin layer and the surface constituting the innermost surface of the film for packaging materials has a protruding peak volume Vmp of 0.08 to 0.3 µm 3 /µm 2 . Or the film for packaging materials according to 4.
[Claim 6]
The packaging film according to any one of claims 3 to 5, further comprising a second resin layer provided on the second surface of the first resin layer.
[Claim 7]
The packaging film according to any one of claims 3 to 6, wherein the first resin layer further contains at least one additive selected from the group consisting of the following resin materials (i) to (vii): .
(i) Block copolymer of polypropylene and polyethylene
(ii) a block copolymer of polyethylene and ethylene-butylene
(iii) a block copolymer of polyethylene and ethylene-octene
(iv) Ethylene-based elastomer
(v) propylene elastomer
(vi) butene elastomer
(vii) Reactor TPO
[Claim 8]
The packaging film according to claim 7, wherein the first resin layer contains the (v) propylene-based elastomer.
[Claim 9]
The packaging film according to claim 7 or 8, wherein at least one of the softening point and melting point of the additive is 130°C or less.
[Claim 10]
base material and
The packaging film according to any one of claims 3 to 9 provided on the base material,
with
A laminated film in which the first resin layer is arranged on at least one outermost surface.
[Claim 11]
A packaging material made of the laminated film according to claim 10.
[Claim 12]
The packaging material according to claim 11, which is used for a package in which an oil-in-water dispersion type content is stored in a sealed state and subjected to heat treatment.
[Claim 13]
The packaging material according to claim 12, wherein the oil-in-water dispersion type content has a lipid content of 0.1% by mass or more and less than 50% by mass.