Packaging films, packaging materials, packaging bags, and packaging bodies

Abstract

To provide a film for a packaging material which can impart excellent slipperiness to oil-in-water dispersion type contents by heating treatment.SOLUTION: A film for a packaging material includes a first resin layer including a polyolefin resin and a filler, wherein a projection is formed by a filler on the surface of the first resin layer, and a fall angle of water of a normal temperature in an oil film of the first resin layer which is measured by the following measurement method is 20° or less. (Measurement method) a) A packaging bag formed so that the first resin layer is arranged therein is prepared using a packaging material including a base material and a film for a packaging material provided on the base material. b) A package including a packaging bag and oil-in-water dispersion type contents sealed into the packaging bag is prepared. c) The package is subjected to retort treatment and boiling treatment. d) A fall angle of water of a normal temperature in an oil film formed on the surface of the first resin layer is measured by a contact angle meter under conditions of a liquid amount of 20 μL and speed of 90° / min.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a film for packaging materials, packaging materials, packaging bags, and packaging bodies. [Background technology]

[0002] Packaging containing oil-in-water dispersed contents such as curry is well known. With such packaging, problems have been pointed out, such as waste resulting from not being able to use all of the contents when opening the packaging and discharging the contents, contamination due to the contents sticking to the packaging, and the time and effort required for discharging the contents.

[0003] Therefore, packaging is required to allow the contents to slide out easily when opened, that is, to provide the contents with excellent sliding properties.

[0004] For example, Patent Document 1 proposes a packaging body using a packaging sheet that contains polyolefin particles with an average particle size D50 of 10 to 50 μm and a melting point of 100 to 180°C, and has a heat-seal layer with a surface roughness Ra of 1.00 to 7.00 μm, thereby making it less likely for the contents to adhere to the surface and allowing for easy discharge from the packaging body. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] International Publication No. 2018 / 003978 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, the packaging described in Patent Document 1 above had the following problems. In other words, the packaging described in Patent Document 1 above had room for improvement in terms of ease of discharging the contents upon opening, i.e., the ease with which the contents slide out.

[0007] The present invention has been made in view of the above circumstances, and aims to provide a packaging film that can impart excellent sliding properties to oil-in-water dispersed contents by heat treatment, a packaging material equipped therewith, a packaging bag, and a packaging body. In the present invention, oil-in-water dispersed contents refer to contents that contain water and lipids, with the water content being greater than the lipid content. "Lipids" is a concept that includes oils that are liquid at 20°C (room temperature) and fats that are solid at 20°C. Hereinafter, the oil contained in the oil-in-water dispersed contents and the fats that become liquid by the heat treatment applied to the packaging film according to the present invention will be collectively referred to as "oil content". [Means for solving the problem]

[0008] One aspect of the present invention, which solves the above problems, is a packaging film comprising a first resin layer containing a polyolefin resin and a filler, wherein a protrusion is formed on the surface of the first resin layer by the filler, and the angle at which water at room temperature falls into the oil film on the surface of the first resin layer, as measured by the following measurement method, is 20° or less. (Measurement method) a) Prepare a packaging bag using a packaging material comprising a base material and a packaging film provided on the base material, such that the first resin layer is positioned on the inside. b) Prepare a package comprising a packaging bag and an oil-in-water dispersion type of contents sealed inside the packaging bag. c) The packaged items are subjected to retort processing and boiling processing. d) The angle at which water at room temperature falls onto the oil film formed on the surface of the first resin layer is measured using a contact angle meter under the conditions of a liquid volume of 20 μL and a velocity of 90° / min.

[0009] According to this packaging film, the polyolefin resin in the first resin layer can absorb oil and swell under the temperature conditions of retort or boiling treatment. Therefore, when the packaging film is used as packaging material for a package containing an oil-in-water dispersion type contents, and the oil-in-water dispersion type contents are subjected to heat treatment such as retort or boiling treatment while in contact with the surface of the first resin layer of the packaging film, a portion of the oil in the contents is absorbed into the first resin layer. At this time, the angle at which room temperature water falls onto the oil film on the surface of the first resin layer, as measured by the predetermined measurement method, is 20° or less. This means that the surface of the first resin layer on the contents side has appropriate irregularities due to the filler, and the oil contained in the contents is absorbed into the first resin layer, improving the lipophilicity of the first resin layer. The presence of an oil film on the surface of the first resin layer, and the angle at which room-temperature water slides across the oil film being 20° or less, prevents the contents from directly contacting the surface of the first resin layer. Furthermore, the water-repellent oil film acts as an interface, making the contents, whose surface layer is composed of water, more slippery. Therefore, the packaging film of the present invention can be given excellent slipperiness for oil-in-water dispersed contents by heat treatment.

[0010] In the above packaging film, the amount of oil film formed is 0.2 to 1.2 g / 200 cm. 2 It is preferable that the amount of oil film is within the above range, as this makes it easier to maintain good slipperiness to the contents.

[0011] In the above-mentioned packaging film, it is preferable that the filler includes a porous filler. By using a porous filler, an oil film is more easily and stably formed between the surface of the first resin layer and the contents, and it is easier to achieve even better sliding properties for the contents.

[0012] In the above-mentioned packaging film, it is preferable that the first resin layer further contains an elastomer component. This makes it easier to achieve even better sliding properties for the contents.

[0013] Another aspect of the present invention is a packaging material including a base material and a film for packaging provided on the base material, wherein the film for packaging is composed of the film for packaging described above, and the surface of the first resin layer of the film for packaging on the side opposite to the base material is exposed.

[0014] This packaging material includes the above-mentioned film for packaging. By heat-treating the film for packaging in a state where an oil-in-water dispersion type content is brought into contact with the exposed surface on the side opposite to the base material, excellent slipperiness can be imparted to the oil-in-water dispersion type content. Further, since this packaging material further includes a base material, the film for packaging is reinforced by the base material.

[0015] Yet another aspect of the present invention is a packaging bag for containing an oil-in-water dispersion type content, which is formed using the above-mentioned packaging material and in which the first resin layer is disposed on the inner side.

[0016] According to this packaging bag, the film for packaging contained in the packaging material can impart excellent slipperiness to the oil-in-water dispersion type content that comes into contact with the first resin layer by heat treatment. Therefore, after an oil-in-water dispersion type content is sealed in the packaging bag to obtain a package and the package is subjected to a heat treatment such as a retort treatment or a boiling treatment, when the oil-in-water dispersion type content is discharged from the package after the package is opened, the oil-in-water dispersion type content can be easily made to slide. For this reason, the amount of residual liquid of the oil-in-water dispersion type content can be reduced, waste of the content can be prevented, soiling due to adhesion of the content can be prevented, and the discharge operation of the content can be efficiently performed.

[0017] Still another aspect of the present invention is a package including the above-mentioned packaging bag and an oil-in-water dispersion type content sealed in the packaging bag.

[0018] With this packaging, the packaging film contained in the packaging material can be given excellent sliding properties to the oil-in-water dispersion contents that come into contact with the first resin layer through heat treatment. Therefore, when the packaging is subjected to heat treatment such as retort treatment or boiling treatment, the oil-in-water dispersion contents can be easily slid out of the packaging when it is discharged after opening the packaging. As a result, the amount of residual liquid of the oil-in-water dispersion contents can be reduced, waste of contents can be prevented, contamination due to contents adhering can be prevented, and the contents can be discharged efficiently. [Effects of the Invention]

[0019] According to the present invention, a packaging film that can be imparted with excellent slipperiness to oil-in-water dispersions by heat treatment, a packaging material, a packaging bag, and a packaging body equipped therewith are provided. [Brief explanation of the drawing]

[0020] [Figure 1] Figure 1 is a schematic cross-sectional view showing one embodiment of the packaging material according to the present invention. [Figure 2] Figures 2(a) to 2(c) are a series of schematic diagrams illustrating the mechanism by which the packaging material according to the present invention can impart excellent sliding properties to oil-in-water dispersed contents. [Figure 3] Figure 3 is a cross-sectional view showing one embodiment of the packaging according to the present invention. [Figure 4] Figures 4(a) to 4(e) are a series of schematic diagrams illustrating a method for evaluating the slipperiness of contents in packaging materials. [Modes for carrying out the invention]

[0021] Embodiments of the present invention will be described in detail below with reference to the drawings. In the drawings, identical or equivalent components are denoted by the same reference numeral, and redundant descriptions are omitted. Furthermore, the dimensional ratios in the drawings are not limited to those shown.

[0022] <Packaging material> First, an embodiment of the packaging material of the present invention will be described with reference to Figures 1 and 2. Figure 1 is a schematic cross-sectional view showing an embodiment of the packaging material according to the present invention, and Figures 2(a) to 2(c) are a series of schematic diagrams illustrating the mechanism by which the packaging material according to the present invention can provide excellent sliding properties for oil-in-water dispersed contents.

[0023] The packaging material 100 shown in Figure 1 is used to form a packaging bag for containing oil-in-water dispersion contents. Oil-in-water dispersion contents are contents that contain water and oil, with the water content being greater than the oil content. The amount of oil contained in the oil-in-water dispersion contents 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. Specific examples of oil-in-water dispersion contents include curry, Hayashi sauce, pasta sauce (e.g., meat sauce), and pet food. The amount of oil 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.

[0024] The packaging material 100 comprises a base material 10, a packaging material film 20 provided on the base material 10, and an adhesive layer 30 that adheres the base material 10 and the packaging material film 20 together.

[0025] The packaging film 20 comprises a first resin layer 21 and a second resin layer 22, both containing polyolefin resin and filler. In the packaging film 20, the first resin layer 21 is positioned on the side opposite to the base material 10, while the second resin layer 22 is positioned on the side facing the base material 10. That is, the surface S of the first resin layer 21 opposite to the base material 10 is exposed. This surface S of the first resin layer 21 becomes the inner surface of the packaging bag when the packaging material 100 is used to form a packaging bag (for example, a retort pouch).

[0026] The first resin layer 21 contains a resin composition 21a comprising a polyolefin resin and a filler 21b dispersed in the resin composition 21a. A protrusion is formed on the surface S of the first resin layer by the filler 21b.

[0027] According to the above packaging material 100, the polyolefin resin contained in the first resin layer 21 of the packaging film 20 can absorb oil and swell under the temperature conditions of retort or boiling treatment. For this reason, if the packaging material 100 is used in a package containing an oil-in-water dispersion type contents C, and the oil-in-water dispersion type contents C is in contact with the surface S of the first resin layer 21 of the packaging film 20 (see Figure 2(a)), and heat treatment such as retort or boiling is performed in this state, the oil C contained in the contents C will swell. O A portion of it is absorbed into the first resin layer 21 (see Figure 2(b)).

[0028] At this time, the oil film F on the surface S of the first resin layer 21 is measured by the measurement method described later. O The angle at which room temperature water falls is 20° or less. This means that the surface of the first resin layer 21 on the side with contents C has appropriate irregularities due to the filler 21b, and the oil C contained in contents C O However, this means that it is absorbed by the first resin layer 21, improving the lipophilicity of the first resin layer 21.

[0029] By appropriately adjusting the degree of formation of protrusions by the filler 21b on the surface S of the first resin layer 21, an oil film F is formed between the surface S of the first resin layer 21 and the contents C. O This makes it easier for a stable layer to form. Then, an oil film F is formed between the surface S of the first resin layer 21 and the contents C. O The presence of this allows the water's falling angle to be set within a desired range, preventing the contents C from directly contacting the surface S of the first resin layer 21, and also preventing the water-repellent oil film F from forming. O With this as the interface, the contents C, whose surface layer is composed of water, become slippery.

[0030] Therefore, as shown in Figure 2(c), the oil-in-water dispersed contents C form an oil film F simply by tilting the surface S of the packaging material 100. O The surface becomes slippery. Therefore, the packaging material 100 can be given excellent slipperiness for the oil-in-water dispersed contents C by heat treatment.

[0031] Furthermore, since polyolefin resin has heat-sealing properties, the first resin layer 21 can also function as a sealant film. Therefore, when forming a package, the packaging material 100 can be easily formed by heat-sealing the first resin layers 21 together with the first resin layers 21 facing inward.

[0032] The first resin layer 21, the second resin layer 22, the base material 10, and the adhesive layer 30 that constitute the packaging material 100 will be described below.

[0033] (First resin layer) The first resin layer 21 is a layer that provides excellent sliding properties to the oil-in-water dispersed contents C by being subjected to heat treatment (e.g., retort treatment and boiling treatment) while in contact with the contents C.

[0034] The polyolefin resin content in the resin composition 21a is usually 75% by mass or more, but may be 80% by mass or more, or 90% by mass or more. The resin composition 21a may consist substantially of polyolefin resin.

[0035] Examples of polyolefin resins include polypropylene resin, polyethylene resin, and polybutylene resin. Among these, polypropylene resin is preferred due to its excellent heat resistance. Examples of polyethylene resins include low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, and ethylene-α-olefin copolymers. Examples of polypropylene resins include homopolypropylene, block polypropylene, random polypropylene, propylene-α-olefin copolymer, and modified polypropylene. When block polypropylene and random polypropylene are used in combination as the polypropylene resin, the mass ratio of block polypropylene to random polypropylene (block polypropylene / random polypropylene) is preferably 20 / 80 to 80 / 20, and more preferably 40 / 60 to 60 / 40. Examples of random polypropylene include Prime PolyPro F744NP and F-300SP manufactured by Prime Polymer Co., Ltd. Examples of block polypropylene include Novatec BC3HF and BC5FA manufactured by Nippon Polypropylene Co., Ltd. In addition to the above, the polyolefin resin may also be a cyclic polyolefin such as polynorbornene. Furthermore, from the viewpoint of sealing properties and strength properties (tensile strength, impact strength, etc.), linear polyolefins are preferred as the polyolefin resin, and the linear polyolefin may be linear or branched.

[0036] Examples of α-olefin components in ethylene-α-olefin copolymers and propylene-α-olefin copolymers include ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, and 4-methyl-1-pentene. The copolymer may be a random copolymer or a block copolymer.

[0037] Modified polypropylene can be obtained by graft-modifying polypropylene with unsaturated carboxylic acid derivative components, such as unsaturated carboxylic acids, acid anhydrides of unsaturated carboxylic acids, and esters of unsaturated carboxylic acids. Alternatively, modified polypropylenes such as hydroxyl-modified polypropylene and acrylic-modified polypropylene can be used as the polypropylene resin. Examples of α-olefin components used to obtain propylene copolymers include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, and 4-methyl-1-pentene.

[0038] Examples of the filler 21b include organic fillers such as olefin fillers and acrylic fillers, inorganic fillers such as silica fillers, and porous fillers. Examples of the olefin filler include the Miporon (registered trademark) series manufactured by Mitsui Chemicals, Inc. and the CS series manufactured by Sumitomo Chemical Co., Ltd. Examples of the acrylic filler include the MX series manufactured by Soken Chemical & Engineering Co., Ltd. and the Uni Powder NMB series manufactured by ENEOS Liquid Crystal Co., Ltd. Examples of the silica filler include the Smooth Master series manufactured by Dainichi Seika Kogyo Co., Ltd., the Cylohbic series manufactured by Fuji Silysia Chemical Ltd., the Admafine SO series manufactured by Admatechs Co., Ltd., the Silica TMS series manufactured by Teika Co., Ltd., and the Sunsfair series manufactured by AGC SI Tech Co., Ltd. Examples of the porous filler made of an organic substance include the Tech Polymer MBP series and the Tech Polymer ACP series manufactured by Sekisui Chemical Co., Ltd. Examples of the porous filler made of an inorganic substance include the Cylohbic series manufactured by Fuji Silysia Chemical Ltd. and the Sunsfair series manufactured by AGC SI Tech Co., Ltd. The filler may be used alone or in combination of two or more types having different compositions, particle sizes, etc.

[0039] When the porous filler is contained in the first resin layer 21 at an appropriate content rate, this porous filler can adsorb the oil component C O and promotes the absorption of the oil component C contained in the oil-in-water dispersion type content C into the first resin layer 21. In this case, due to the synergistic effect between the unevenness of the surface S of the first resin layer 21 and the improvement of lipophilicity by oil absorption, an oil film F O is more easily and stably formed between the surface S of the first resin layer 21 and the content C. Therefore, it is easier to exhibit more excellent slipperiness with respect to the content C. O

[0040] Porous fillers can be said to include a main body. The main body included in the porous filler may be inorganic or organic. Examples of organic materials include polyolefin resins and acrylic resins. Examples of acrylic resins include cross-linked poly(meth)acrylic acid esters such as cross-linked polymethyl methacrylate. These can be used individually or in combination of two or more. Examples of inorganic materials include mineral fillers such as silica, talc, ceramics, glass beads, and calcium carbonate, as well as carbon black, glass fibers, ceramic fibers, and carbon fibers. These can also be used individually or in combination of two or more.

[0041] The porous filler may further include a covering portion that covers at least a part of the main body. The covering portion may be made of a hydrophilic material or a hydrophobic material, but it is preferable that it be made of a hydrophobic material. Here, a hydrophobic material refers to a material with a DBA (di-n-butylamine) value of 200 mEq / kg or less, and the DBA value refers to the amount of DBA adsorbed on the surface of the main body. The DBA value corresponds to the amount of DBA adsorbed on the hydroxyl groups on the surface of the main body, and a smaller DBA value means that there are fewer hydroxyl groups (higher hydrophobicity).

[0042] A porous filler, composed of a main body and a coating, can be obtained, for example, by chemically reacting the main body with a hydrophobic material raw material, that is, by hydrophobicating the main body. Examples of hydrophobic material raw materials include organosilicon compounds. Among these, organosilicon compounds are preferred as the hydrophobic material raw material.

[0043] The average particle size of filler 21b is determined by the following method, depending on the type of filler. (Calculation method using laser diffraction particle size distribution measurement) (1) Disperse the filler 21b in a dispersion medium. The dispersion medium is, for example, water or an organic solvent, and an appropriate one is selected depending on the type of filler. (2) Using a laser diffraction particle size distribution analyzer (product name: "MT3300EX II", manufactured by Microtrac-Bel), the average particle size of filler 21b is calculated by laser diffraction and scattering. (Calculation method using microscopic observation) If the above-described laser diffraction particle size distribution measurement is unsuitable or difficult, the average particle size of filler 21b may be determined using an optical microscope such as a scanning electron microscope (SEM) or laser microscope. For any particle observed within the field of view under a microscope, the longest and shortest diameters of the particle are measured, and the sum of these lengths divided by two is defined as the particle diameter. The particle diameters of multiple particles are measured and calculated, and the average value is considered the average particle diameter. Preferably, the number of arbitrary particles is 10 or more.

[0044] The average particle size of the filler 21b is preferably 3 μm or larger. In this case, an appropriate amount of filler 21b can be added to create an appropriate surface texture, thereby efficiently improving the sliding properties of the contents C while reducing the impact on the physical properties of the packaging film 20, such as a decrease in seal strength.

[0045] The average particle size of filler 21b is more preferably 5 μm or larger, and particularly preferably 7 μm or larger.

[0046] The average particle size of the filler 21b is preferably 30 μm or less. In this case, compared to the case where the average particle size of the filler 21b exceeds 30 μm, an oil film F is formed on the surface of the first resin layer 21. O This makes it easier to form the film, and the packaging film 20 can provide better slip resistance to the oil-in-water dispersed contents C enclosed in the package.

[0047] The average particle size of filler 21b is more preferably 20 μm or less, and even more preferably 15 μm or less.

[0048] The content of filler 21b in the first resin layer 21 is preferably 0.5 to 30% by mass. In this case, compared to when the content of filler 21b falls outside the above range, the packaging film 20 is more likely to impart superior sliding properties to the oil-in-water dispersed contents C enclosed in the packaging. The content of filler 21b in the first resin layer 21 is preferably 1 to 15% by mass, and more preferably 3 to 10% by mass. The content of filler 21b in the first resin layer 21 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, per 100 parts by mass of polyolefin resin. Having the content of filler 21b within the above range allows for appropriate irregularities to be imparted to the surface S of the first resin layer 21.

[0049] The thickness of the first resin layer 21 is the value obtained as follows: (1) First, the packaging film 20 is fixed with embedding resin (acrylic resin) to prepare the structure. (2) A sample for cross-sectional observation is cut from the structure using a microtome. (3) Observe the cross-section of the sample cut out for cross-sectional observation using a microscope (product name: VHX-1000, manufactured by Keyence Corporation). (4) The thickness of the first resin layer 21 is measured at three locations along the thickness direction where filler 21b is not present, and the average of the thicknesses at these three locations is calculated as the thickness of the first resin layer 21.

[0050] The thickness of the first resin layer 21 is, for example, 2 to 100 μm, preferably 4 to 70 μm, more preferably 6 to 50 μm, and even more preferably 8 to 30 μm. By having the thickness of the first resin layer 21 within the above range, both the sliding properties and heat sealability of the contents C can be achieved at a high level. Here, heat sealability refers, for example, to the property that heat sealing is possible under conditions of 100 to 200°C, 0.1 to 0.3 MPa, and 1 to 3 seconds.

[0051] The oil film F on the surface S of the first resin layer 21 is measured by the following measurement method. OThe angle of fall of room temperature water in this case is 20° or less. This means that the surface S on the contents C side of the first resin layer 21 has appropriate irregularities due to the filler 21b, and the oil C contained in the contents C O However, this means that the water is absorbed into the first resin layer 21, improving the lipophilicity of the first resin layer 21. The water fall angle is preferably 15° or less, and more preferably 10° or less. The lower limit of the water fall angle is not particularly limited, but it can preferably be 5°. The water fall angle can be varied by appropriately adjusting the degree of formation of protrusions by the filler 21b on the surface S of the first resin layer 21 from the viewpoint of the amount and particle size of the filler 21b. (Measurement method) a) Prepare a packaging bag using a packaging material comprising a base material and a packaging film provided on the base material, such that the first resin layer is positioned on the inside. b) Prepare a package comprising a packaging bag and an oil-in-water dispersion type of contents sealed inside the packaging bag. c) The packaging is subjected to retort treatment and boiling treatment. Retort treatment refers to heat treatment under the conditions of pressure: 0.2 MPa, temperature: 121°C, and processing time: 30 minutes, while boiling treatment refers to heat treatment under the conditions of pressure: normal pressure, temperature: 100°C, and processing time: 5 minutes. d) The angle at which room-temperature water falls onto the oil film formed on the surface of the first resin layer is measured using a contact angle meter (measuring device: KRUSS DSA25 simple contact angle meter) under the conditions of a liquid volume of 20 μL and a speed of 90° / min. Room temperature here refers to 25°C.

[0052] Oil film F formed on the surface S of the first resin layer 21 O The amount is 0.2-1.2g / 200cm 2 It is preferable that the amount of oil film is within the above range. When the amount of oil film is within the above range, it is easier to maintain good slipperiness to the contents. Oil film F O If the amount exceeds the upper limit, an oil film exceeding the amount necessary to promote slipperiness is formed, resulting in excess oil film remaining inside the packaging bag and a decrease in the amount of contents discharged. Oil film F OIf the amount is below the lower limit, the retention and stabilization effect of the oil film by the protrusions tends to be insufficient, and the sliding properties on the contents C tend to decrease. Oil film F O The amount is more preferably 0.4g / 200cm 2 The above is true, and more preferably 0.6g / 200cm 2 That's all. Oil film F O The amount is more preferably 1.0g / 200cm 2 The following, and more preferably 0.8g / 200cm 2 The following is the oil film F. O The amount is calculated from the weight of the sample before and after wiping off the oil film formed by the above measurement method with isopropyl alcohol (IPA).

[0053] The first resin layer 21 may further contain elastomer components from the viewpoint of exhibiting even better sliding properties. Examples of elastomer components include block copolymers of polypropylene and polyethylene, block copolymers of polyethylene and ethylene-butylene, block copolymers of polyethylene and ethylene-octene, ethylene-based elastomers, propylene-based elastomers, butene-based elastomers, and reactor TPO. Reactor TPO (reactor thermoplactic polyolefin) is a type of olefin-based thermoplastic elastomer (TPO), which is composed of polypropylene as a base resin and rubber components finely dispersed therein by adding a high concentration of rubber components during polymerization, for example. Examples of ethylene-based elastomers and propylene-based elastomers include the Toughmer series manufactured by Mitsui Chemicals, Inc. The elastomer components may be used individually or in combination of two or more types.

[0054] The amount of elastomer component added (total amount if multiple elastomer components are added) is, for example, 30 parts by mass or less, preferably 1 to 25 parts by mass, more preferably 2 to 20 parts by mass, and even more preferably 3 to 15 parts by mass, per 100 parts by mass of polyolefin resin. The amorphous portion (rubber component) contained in the elastomer component has the property of absorbing oil. Therefore, the elastomer component forms a stable and uniform oil film F O This promotes the formation of a certain layer, thereby further improving the sliding properties of the contents C.

[0055] (Second resin layer) The second resin layer 22 is a layer provided between the first resin layer 21 and the base material 10. By further comprising the second resin layer 22 in the packaging material 100, functions corresponding to the functions of the second resin layer 22 (heat sealability, heat resistance and impact resistance, oxygen and water vapor barrier properties, etc.) can be imparted to the packaging material 100. For example, from the viewpoint of improving heat sealability, it is preferable that the second resin layer 22 contains a thermoplastic resin. Specific examples of thermoplastic resins include polyolefin resins, ethylene-α,β unsaturated carboxylic acid copolymers or their esterified or ionically crosslinked products, ethylene-vinyl acetate copolymers or their saponified products, polyvinyl acetate or its saponified products, polycarbonate resins, thermoplastic polyester resins, ABS resins, polyacetal resins, polyamide resins, polyphenylene oxide resins, polyimide resins, polyurethane resins, polylactic acid resins, furan resins, and silicone resins. These thermoplastic resins can be used individually or in combination of two or more.

[0056] The thickness of the second resin layer 22 can be appropriately set according to the application of the packaging material 100. For example, the thickness of the second resin layer 22 is 1 to 300 μm, preferably 2 to 200 μm, more preferably 5 to 150 μm, and even more preferably 10 to 100 μm.

[0057] (base material) The base material 10 is not particularly limited as long as it serves as a support and has durability against heat treatment such as retort treatment or boiling treatment. Examples include resin films and metal foils. Examples of resin films include films containing at least one of the following: 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, and cellophane resin. This film may be a stretched film or an unstretched film. Examples of metal foils include aluminum foil and nickel foil. The base material 10 may be a laminate of multiple base materials of different materials, and may include a coating layer or a metal vapor deposition layer.

[0058] The thickness of the base material 10 can be set appropriately depending on the application of the packaging material 100. For example, the thickness of the base material 10 may be 1 to 500 μm, or it may be 10 to 100 μm.

[0059] (adhesive layer) The adhesive layer 30 adheres the packaging film 20 (a laminate of the first resin layer 21 and the second resin layer 22) to the substrate 10. The adhesive constituting the adhesive layer 30 is not particularly limited as long as it can adhere the packaging film 20 to the substrate 10. Examples of such adhesives include polyurethane resins obtained by reacting a bifunctional or more isocyanate compound with a main component such as polyester polyol, polyether polyol, acrylic polyol, or carbonate polyol. Various polyols may be used individually or in combination of two or more.

[0060] The adhesive layer 30 may contain the above-mentioned polyurethane resin, carbodiimide compounds, oxazoline compounds, epoxy compounds, phosphorus compounds, silane coupling agents, etc., for the purpose of promoting adhesion. Depending on the performance required for the adhesive layer 30, other various additives and stabilizers may be added to the above-mentioned polyurethane resin.

[0061] The thickness of the adhesive layer 30 is, for example, 1 to 10 μm, and may also be 3 to 7 μm, from the viewpoint of obtaining the desired adhesive strength, conformability, and processability.

[0062] The substrate 10 may also be provided with an adhesive primer (anchor coat), and suitable materials for this primer include polyester resins, polyurethane resins, polyallylamine resins, polyethyleneimine resins, polybutadiene resins, ethylene-vinyl acetate copolymers, and chlorine-vinyl acetate resins. The adhesive primer may also contain various curing agents and additives that can be used as adhesives, as needed.

[0063] <Manufacturing method for packaging materials> Next, we will explain the manufacturing method of the packaging material described above.

[0064] The packaging material 100 can be obtained by laminating a packaging film 20 and a base material 10. Methods for laminating the base material 10 and the packaging film 20 include, for example, lamination using an adhesive and lamination using heat treatment.

[0065] Various known lamination methods can be used for lamination with adhesives, including dry lamination, wet lamination, and non-solvent lamination.

[0066] Lamination methods using heat treatment can be broadly categorized into the following methods (1) to (4). (1) A method of laminating an adhesive resin between a pre-made packaging film 20 and a base material 10. (2) A method of co-extruding a packaging film 20 and an adhesive resin, and laminating the adhesive resin with the substrate 10 with the substrate 10 facing the substrate 10. (3) A method of bonding the laminate obtained by the method of (1) or (2) above by further heating and applying pressure with a hot roll. (4) A method of further storing the laminate obtained by the method of (1) or (2) above in a high-temperature atmosphere, or passing it through a drying and baking furnace in a high-temperature atmosphere.

[0067] <Package> Next, an embodiment of the packaging of the present invention will be described with reference to Figure 3. Figure 3 is a cross-sectional view showing an embodiment of the packaging of the present invention.

[0068] As shown in Figure 3, the packaging 300 comprises a packaging bag 200 and an oil-in-water dispersion type contents C sealed inside the packaging bag 200. In the packaging 300, the first resin layer 21 of the packaging material film 20 of the packaging bag 200 is positioned on the inside and is in contact with the oil-in-water dispersion type contents C.

[0069] According to the above-described packaging 300, the packaging film 20 contained in the packaging material 100 that forms the packaging bag 200 can be given excellent sliding properties to the oil-in-water dispersed contents C that come into contact with the first resin layer 21 by heat treatment. Therefore, when the packaging 300 is subjected to heat treatment such as retort treatment or boiling treatment, the oil-in-water dispersed contents C can be easily slid off when the packaging 300 is discharged after opening the packaging 300. As a result, the amount of residual liquid of the oil-in-water dispersed contents C can be reduced, waste of contents C can be prevented, contamination due to adhesion of contents C can be prevented, and the discharge of contents C can be performed efficiently.

[0070] The above-mentioned packaging 300 can be obtained by forming a packaging bag 200 using packaging material 100 and sealing an oil-in-water dispersion type contents C inside the packaging bag 200.

[0071] Although embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments. For example, in the above embodiments, the packaging film 20 is composed of a first resin layer 21 and a second resin layer 22, but the packaging film 20 may be composed of only the first resin layer 21.

[0072] Furthermore, although the above-mentioned packaging material 100 includes an adhesive layer 30 for bonding the packaging material film 20 and the base material 10, the adhesive layer 30 can be omitted if the packaging material film 20 and the base material 10 can be directly fused together. [Examples]

[0073] The present invention will be described more specifically below based on examples and comparative examples, but the present invention is not limited to the following examples.

[0074] The materials used in each experimental example are as follows: <Polyolefin resin> (A1) Random polypropylene resin (propylene-ethylene random copolymer, trade name "Prime PolyPro F744NP", manufactured by Prime Polymer Co., Ltd.) (A2) Block polypropylene resin (propylene-ethylene block copolymer, trade name "Novatec BC5FA", manufactured by Nippon Polypropylene Co., Ltd.) (A3) Block polypropylene resin (propylene-ethylene block copolymer, trade name "Novatec BC3HF", manufactured by Nippon Polypropylene Co., Ltd.)

[0075] <Filler> (B1) Acrylic filler (average particle size: 3 μm, product name "Unipowder NMB-0320C", manufactured by ENEOS LCD Corporation) (B2) Acrylic filler (average particle size: 5 μm, product name "Unipowder NMB-0520", manufactured by ENEOS LCD Corporation) (B3) Acrylic filler (average particle size: 10 μm, product name "Unipowder NMB-1020", manufactured by ENEOS LCD Corporation) (B4) Polyethylene filler (average particle size: 10 μm, product name "Mipelon PMPC-1010", manufactured by Mitsui Chemicals, Inc.) (B5) Silica filler (average particle size: 10 μm, product name "TMS-10", manufactured by Teika Co., Ltd.) (B6) Silica filler (average particle size: 5 μm, product name "TMS-05DCA", manufactured by Teika Co., Ltd.) (B7) Silica filler (average particle size: 4 μm, product name "Sunsphere NP30", manufactured by AGC SI-TEC Co., Ltd.) (B8) Silica filler (average particle size: 10 μm, product name "Sunsphere NP100", manufactured by AGC SI-TEC Co., Ltd.) (B9) Porous silica filler (average particle size: 7 μm, product name "Sunsphere L-71-N", manufactured by AGC SI-TEC Co., Ltd.) (B10) Porous silica filler (average particle size: 12 μm, product name "Sunsphere H-121-N", manufactured by AGC SI-TEC Co., Ltd.) (B11) Silica filler (average particle size: 2 μm, product name "FMB-1650B", manufactured by Nippon Polypropylene Co., Ltd.)

[0076] <Elastomer component> (C1) Polypropylene-polyethylene block copolymer (C2) Polypropylene elastomer (product name "Toughmer PN3560", manufactured by Mitsui Chemicals, Inc.) (C3) Polyethylene elastomer (product name "Toughmer A4085S", manufactured by Mitsui Chemicals, Inc.)

[0077] <Manufacturing of packaging materials> Using a co-extruder, a two-layer packaging film (sealant film) was prepared, comprising a first resin layer with the composition shown in Tables 1 and 2, and a second resin layer made of block polypropylene resin (A3). In this case, the mixing ratio of random polypropylene resin (A1) and block polypropylene resin (A2) in the first resin layer was set to a mass ratio of 50 / 50. For Experimental Example 29, the surface properties of the first resin layer were adjusted by mirror finishing (smoothing treatment), and for Experimental Example 30, the surface properties of the first resin layer were adjusted by shaping treatment.

[0078] Next, the obtained packaging film and a 38 μm thick PET film (product name "Emblet," manufactured by Unitika Ltd.), which served as the base material, were dry-laminated using a polyurethane adhesive (manufactured by Mitsui Chemicals, Inc.), and then aged at 50°C for 5 days to obtain the packaging material. In each example, the first and second resin layers were formed so that the combined thickness of the first and second resin layers was 60 μm.

[0079] <Evaluation of the slipperiness of the contents> (Evaluation of residual liquid after retort processing) For each example, the slipperiness of the contents after retort processing was evaluated for the packaging material obtained using the methods shown in Figures 4(a) to 4(e).

[0080] First, two pieces of packaging material, each measuring 150 mm in length and 138 mm in width, were prepared. The two pieces of packaging material were then stacked so that the first resin layer of each was facing inward, and three sides were sealed using a heat sealer. In this way, a packaging bag 200 was created, consisting of a pouch with sealed sections 200a on three sides and an open side, as shown in Figure 4(a). 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 sealed section 200a was set to 10 mm.

[0081] Next, as shown in Figure 4(b), 180g of curry (product name "Bon Curry Gold Medium Spicy", fat content 7.0g / 180g, manufactured by Otsuka Foods Co., Ltd.) as contents C was poured through the opening of the packaging bag 200.

[0082] Subsequently, the opening (the remaining side) was sealed using a heat sealer, forming a sealed portion 200b on the remaining side as shown in Figure 4(c). In this way, a package 300 was created with all four sides sealed and the contents C enclosed. At this time, the heat sealing of the opening was carried out under the conditions of 190°C, 0.03 MPa, and 2 seconds, and the width of the sealed portion was 10 mm.

[0083] The resulting packaged bodies 300 were then placed in a high-temperature, high-pressure cooking and sterilization device (manufactured by Hitachi Capital Corporation) and subjected to retort processing with high-temperature steam. The retort processing was carried out under the following conditions. • Pressure: 0.2 MPa ·Temperature: 121℃ Processing time: 30 minutes

[0084] After retort processing, the package 300 was subjected to a water bath treatment (boiling treatment) at 100°C for 5 minutes. Then, as shown in Figure 4(d), the top of the package 300 was cut to form a spout. Next, as shown in Figure 4(e), the pouch was turned upside down, and the spout was held at a 45° angle from the horizontal plane for 10 seconds to discharge the contents C into the container 400, and the amount discharged was weighed using a scale 500. The residual liquid percentage (%) was then calculated from the weighed amount using the following formula. Residual liquid rate (%)={(180-discharge amount) / 180}×100 Similar measurements were performed three times, each time using a different package (300 units), and the average of the three residual liquid percentages was calculated as the average residual liquid percentage. Furthermore, the slipperiness of the contents was evaluated based on the average residual liquid percentage according to the following evaluation criteria. The results of the evaluation of the average residual liquid percentage and the slipperiness of the contents are shown in Tables 1 and 2. A: Average residual liquid percentage is less than 6.5% B: Average residual liquid percentage is 6.5% or more and less than 8.0% C: Average residual liquid percentage is 8.0% or more and less than 10.0% D: Average residual liquid percentage is 10.0% or higher

[0085] (Appearance evaluation after retort processing) When measuring the residual liquid percentage as described above, the discharge behavior of the contents (curry) C when it was discharged from the pouch was visually observed, and an appearance evaluation was also performed according to the evaluation criteria below. The results are shown in Tables 1 and 2. A: The contents slide off cleanly, and there is almost no adhesion of the contents to the packaging film. B: The contents appear to slide out, and the amount of contents adhering to the packaging film is small. C: The contents appear to be sliding out, and a large amount of the contents are adhering to the packaging film. D: No signs of the contents falling out were observed.

[0086] <Evaluation of surface properties of the first resin layer> (Measuring the angle of water fall) The pouches used for evaluating the slipperiness of the contents were washed with water and dried. A drop of room-temperature water was placed on the first resin layer (oil film) on the inner surface of the pouch, and the angle at which the water droplet began to move was measured using a fall angle meter. The same measurement was performed three times, changing the packaging 300 each time, and the average value was taken as the fall angle (°). The results are shown in Tables 1 and 2. Measurement device: KRUSS DSA25 simple contact angle meter Volume: 20 μL Speed: 90° / min

[0087] (Oil film amount measurement) The pouch used for evaluating the slipperiness of the contents was washed with water and dried. The two packaging materials constituting the pouch were cut into 10cm x 10cm sections, and the weight of each section with the oil film attached was measured to determine the total weight 'a'. Next, the surface of the first resin layer was wiped with isopropyl alcohol (IPA), and after thorough drying, the weight of each section with the oil film removed was measured to determine the total weight 'b'. The difference between 'a' and 'b' (ab) was then calculated. This process was repeated three times with 300 different packaging units, and the average value was used to determine the amount of oil film (g / 200cm²). 2 The results are shown in Tables 1 and 2.

[0088] [Table 1]

[0089] [Table 2]

[0090] As shown in Tables 1 and 2, the packaging obtained in Experimental Examples 1-28 (Examples) had a low average residual liquid rate, and the contents appeared to slide out. In contrast, the packaging obtained in Experimental Examples 29-31 (Comparative Examples) had a high average residual liquid rate, and the contents did not appear to slide out.

[0091] From the above, it has been confirmed that the packaging film of the present invention can impart excellent slipperiness to oil-in-water dispersed contents through heat treatment. [Explanation of symbols]

[0092] 10...Base material, 20...Film for packaging material, 21...First resin layer, 21a...Resin composition, 21b...Filler, 30...Adhesive layer, 100...Packaging material, 200...Packaging bag, 300...Packaging body, C...Contents, C O ...oil content, S...surface of the first resin layer, F O ...Oil slick.

Claims

1. The first resin layer comprises a polyolefin resin, an inorganic filler, and an elastomer component. The inorganic filler content in the first resin layer is 0.5 to 10% by mass, and the amount of elastomer component added is 1 to 30 parts by mass per 100 parts by mass of the polyolefin resin. A protrusion is formed on the surface of the first resin layer by the inorganic filler. A packaging film in which the angle at which room temperature water falls into the oil film on the surface of the first resin layer, as measured by the following measurement method, is 20° or less. (Measurement method) a) Prepare a packaging bag using a packaging material comprising a base material and the packaging film provided on the base material, such that the first resin layer is positioned on the inside. b) Prepare a package comprising the packaging bag and an oil-in-water dispersion type contents sealed inside the packaging bag. c) The package is subjected to retort processing and boiling processing. d) The angle at which water at room temperature falls onto the oil film formed on the surface of the first resin layer is measured using a contact angle meter under the conditions of a liquid volume of 20 μL and a velocity of 90° / min.

2. The amount of the oil film is 0.2 to 1.2 g / 200 cm ２ The packaging film according to claim 1.

3. The packaging film according to claim 1 or 2, wherein the inorganic filler includes a porous filler.

4. Substrate and A packaging film provided on the substrate, Equipped with, The aforementioned packaging film is made from the packaging film described in any one of claims 1 to 3. A packaging material in which the surface of the first resin layer of the packaging film that is opposite to the substrate is exposed.

5. A packaging bag for containing oil-in-water dispersion contents, A packaging bag formed using the packaging material described in claim 4, wherein the first resin layer is arranged on the inside.

6. The packaging bag according to claim 5, A package comprising an oil-in-water dispersion type contents sealed inside the aforementioned packaging bag.

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