Resin film, laminate and bag

Abstract

To provide a resin film, a laminate, and a bag that reduce environmental loads, have sealability and deposition property, and have an excellent tearing property.SOLUTION: Provided is a resin film at least including a first layer, a second layer, and a third layer. The first layer and the second layer are laminated on top of each other directly or with a thermoplastic resin layer interposed therebetween. The third layer is laminated on the second layer directly or with a thermoplastic resin layer interposed therebetween. The first layer constitutes an innermost layer of the resin film. The resin film contains polypropylene and polyethylene. A resin composition constituting the first layer contains polypropylene as a main component. A resin composition constituting the second layer contains polypropylene as a main component and biomass polyethylene. A resin composition constituting the third layer contains polypropylene as a main component. The resin film has a thickness of more than or equal to 15 μm and less than or equal to 250 μm. The resin film has a biomass degree more than or equal to 5%.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a resin film, a laminate, and a bag. [Background technology]

[0002] Films made of polypropylene have moderate flexibility and are excellent in transparency, oil resistance, moisture resistance, chemical resistance, etc., and are inexpensive, and therefore are used for various packaging bags, etc. Furthermore, polypropylene films have sealing properties and are used as sealant films for packaging bags, etc. For example, Patent Document 1 proposes a multilayer film including a polypropylene resin layer and discloses that this multilayer film is used as a sealant film.

[0003] However, although polypropylene film has better heat resistance than polyethylene film, it has the drawback of being inferior to polyethylene film in terms of tearability, which means that when polypropylene film is used for packaging bags, it is difficult to tear and open the packaging bag.

[0004] In recent years, there has been a global demand for a reduction in carbon dioxide emissions in order to curb global warming. As with energy, there is a desire to move away from fossil fuels in the materials field, and the use of biomass has been attracting attention. Biomass is an organic compound formed by photosynthesis from carbon dioxide and water, and by utilizing it, it can be converted back into carbon dioxide and water, making it a so-called carbon-neutral renewable energy source. Recently, the practical application of biomass plastics made from biomass has progressed rapidly, and attempts are being made to produce various resins from biomass raw materials.

[0005] Regarding polypropylene, biomass polypropylene made from biomass has also been put on the market. However, biomass polypropylene is currently much more expensive than fossil fuel polypropylene, making it significantly less practical. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-335108 Summary of the Invention [Problem to be solved by the invention]

[0007] The present inventors have considered reducing the amount of fossil fuel-derived polypropylene used and the environmental impact by replacing a portion of the fossil fuel-derived polypropylene with relatively inexpensive biomass polyethylene. However, resin films containing polypropylene as a primary component have encountered new problems: increased polyethylene content reduces sealing properties and film-forming properties. After extensive research, the present inventors have discovered that these problems can be solved by providing a resin film with a multilayer structure and adjusting the polyethylene content of each layer. Furthermore, they have discovered that such multilayer-structured resin films have unexpectedly improved tear resistance.

[0008] The present invention has been made in light of the above findings, and its object is to provide a resin film, a laminate, and a bag that have a reduced environmental impact, as well as sealing properties and film-forming properties, and are particularly excellent in tearability. [Means for solving the problem]

[0009] The present invention provides a resin film comprising at least a first layer, a second layer, and a third layer, wherein the first layer and the second layer are laminated together directly or via a thermoplastic resin layer, and the third layer is laminated together with the second layer directly or via a thermoplastic resin layer, the first layer constituting the innermost layer of the resin film, the resin film containing polypropylene and polyethylene, the resin composition constituting the first layer containing polypropylene as a main component, and the polyethylene content of the first layer being 20% ​​by mass or less, the resin composition constituting the second layer containing polypropylene as a main component and biomass polyethylene, the polypropylene of the second layer being a propylene-ethylene random copolymer, and the polyethylene content of the second layer being 5% by mass or more and 35% by mass or less, the resin composition constituting the third layer containing polypropylene as a main component, and the polyethylene content of the third layer being 35% by mass or less, the thickness of the resin film being 15 μm or more and 250 μm or less, and the biomass degree of the resin film being 5% or more.

[0010] In the resin film according to the present invention, the layer constituting the outermost layer of the resin film may have a biomass content of 30% or less.

[0011] In the resin film according to the present invention, the polypropylene content may be 66% by mass or more.

[0012] In the resin film according to the present invention, the breaking elongation in one direction and in another direction perpendicular to the one direction may each be 500% or more.

[0013] The present invention is a laminate comprising at least one biaxially oriented plastic film and a resin film according to the present invention.

[0014] The present invention is a bag comprising a laminate according to the present invention. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a resin film, a laminate, and a bag that have a reduced environmental impact, as well as excellent sealing and film-forming properties, and in particular excellent tearability. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a cross-sectional view showing an example of the resin film of the present invention. [Figure 2] FIG. 2 is a cross-sectional view showing another example of the resin film of the present invention. [Figure 3] FIG. 3 is a cross-sectional view showing another example of the resin film of the present invention. [Figure 4] FIG. 4 is a cross-sectional view showing another example of the resin film of the present invention. [Figure 5] FIG. 5 is a cross-sectional view showing another example of the resin film of the present invention. [Figure 6] FIG. 6 is a cross-sectional view showing another example of the resin film of the present invention. [Figure 7] FIG. 7 is a cross-sectional view showing an example of the laminate of the present invention. [Figure 8] FIG. 8 is a cross-sectional view showing another example of the laminate of the present invention. [Figure 9] FIG. 9 is a cross-sectional view showing another example of the laminate of the present invention. [Figure 10] FIG. 10 is a cross-sectional view showing another example of the laminate of the present invention. [Figure 11] FIG. 11 is a cross-sectional view showing another example of the laminate of the present invention. [Figure 12] FIG. 12 is a front view of the bag of the present invention. [Figure 13] FIG. 13 is a diagram showing the cutting out of test pieces for measuring the seal strength and low-temperature sealability of the bag of the present invention. [Figure 14] FIG. 14 is a diagram showing how the seal strength and low-temperature sealability are measured using test pieces. DETAILED DESCRIPTION OF THE INVENTION

[0017] An embodiment of the present invention will be described with reference to Figures 1 to 14. In the drawings accompanying this specification, the scale and aspect ratios have been appropriately changed and exaggerated from those of the actual objects for the sake of ease of illustration and understanding.

[0018] Furthermore, terms used in this specification that specify shapes, geometric conditions, and their degrees, such as "parallel," "orthogonal," and "identical," as well as values ​​of lengths and angles, are not to be construed as being bound by strict meanings, but rather as including a range within which similar functions can be expected.

[0019] Resin film The resin film of the present invention comprises two layers, a first layer and a second layer, which are laminated directly or via a thermoplastic resin layer, with the first layer constituting the innermost layer of the resin film. This allows the resin film to have sealability. In the resin film of the present invention, the innermost layer is the layer located on the side of the contents to be contained when the resin film is used in a bag. The second layer may also constitute the outermost layer of the resin film. In the resin film of the present invention, the outermost layer is the layer located opposite the innermost layer. The resin film of the present invention further includes a third layer, which may be laminated to the second layer directly or via a thermoplastic resin layer. This can prevent curling of the resin film. The third layer may also constitute the outermost layer of the resin film. An example of the layer structure of the resin film of the present invention will be described below with reference to FIGS.

[0020] Fig. 1 is a cross-sectional view showing an example of a resin film 10 of the present invention. The resin film 10 includes a first layer 11 and a second layer 12. The first layer 11 constitutes the innermost layer of the resin film 10. The second layer 12 constitutes the outermost layer of the resin film 10. The first layer 11 and the second layer 12 are directly laminated together.

[0021] 2 is a cross-sectional view showing another example of the resin film 10 of the present invention. The resin film 10 is provided with a first layer 11, a first thermoplastic resin layer 13, and a second layer 12, in that order. The first layer 11 constitutes the innermost layer of the resin film 10. The second layer 12 constitutes the outermost layer of the resin film 10. The first layer 11 and the second layer 12 are laminated with the first thermoplastic resin layer 13 interposed therebetween.

[0022] 3 is a cross-sectional view showing another example of the resin film 10 of the present invention. The resin film 10 is provided with a first layer 11, a second layer 12, and a third layer 14, in that order. The first layer 11 constitutes the innermost layer of the resin film 10. The third layer 14 constitutes the outermost layer of the resin film 10. The first layer 11 and the second layer 12 are directly laminated together. The second layer 12 and the third layer 14 are directly laminated together.

[0023] 4 is a cross-sectional view showing another example of the resin film 10 of the present invention. The resin film 10 is provided with a first layer 11, a second layer 12, a first thermoplastic resin layer 13, and a third layer 14, in that order. The first layer 11 constitutes the innermost layer of the resin film 10. The third layer 14 constitutes the outermost layer of the resin film 10. The first layer 11 and the second layer 12 are laminated directly together. The second layer 12 and the third layer 14 are laminated together with the first thermoplastic resin layer 13 interposed therebetween.

[0024] Fig. 5 is a cross-sectional view showing another example of the resin film 10 of the present invention. The resin film 10 comprises, in order, a first layer 11, a first thermoplastic resin layer 13, a second layer 12, and a third layer 14. The first layer 11 constitutes the innermost layer of the resin film 10. The third layer 14 constitutes the outermost layer of the resin film 10. The first layer 11 and the second layer 12 are laminated with the first thermoplastic resin layer 13 interposed therebetween. The second layer 12 and the third layer 14 are directly laminated.

[0025] 6 is a cross-sectional view showing another example of the resin film 10 of the present invention. The resin film 10 is provided with a first layer 11, a first thermoplastic resin layer 13, a second layer 12, a second thermoplastic resin layer 15, and a third layer 14, in that order. The first layer 11 constitutes the innermost layer of the resin film 10. The third layer 14 constitutes the outermost layer of the resin film 10. The first layer 11 and the second layer 12 are laminated with the first thermoplastic resin layer 13 interposed therebetween. The second layer 12 and the third layer 14 are laminated with the second thermoplastic resin layer 15 interposed therebetween.

[0026] It is also possible to appropriately combine a plurality of layer structures of the resin film 10 shown in the above-mentioned FIGS.

[0027] The resin film of the present invention contains polypropylene, such as a propylene-ethylene block copolymer, a propylene-ethylene random copolymer, a homopolypropylene, and a mixture of two or more of these.

[0028] Here, "propylene-ethylene block copolymer" refers to a material having the structural formula shown in formula (I) below: In formula (I), m1, m2, and m3 each represent an integer of 1 or greater.

[0029] [ka]

[0030] Furthermore, "propylene-ethylene random copolymer" refers to a material having the structural formula shown in formula (II) below: In formula (II), m and n represent integers of 1 or greater.

[0031] [ka]

[0032] Furthermore, "homopolypropylene" refers to a material having the structural formula shown in formula (III) below: In formula (III), m represents an integer of 1 or greater.

[0033] [ka]

[0034] In the resin film of the present invention, the polypropylene content is preferably 66% by mass or more, more preferably 71% by mass or more and 99% by mass or less, and even more preferably 74% by mass or more and 95% by mass or less, which can improve the heat resistance and oil resistance of the resin film.

[0035] In this specification, unless otherwise specified, "propylene" is obtained from raw materials derived from fossil fuels.

[0036] The resin film of the present invention contains polyethylene, which can improve the tearability of the resin film. Examples of polyethylene include high-density polyethylene (HDPE), medium-density polyethylene (MDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and mixtures of two or more of these. From the viewpoint of sealability, the resin film of the present invention preferably contains low-density polyethylene, linear low-density polyethylene, or a mixture thereof, and from the viewpoints of sealability and tearability, it is more preferable that the resin film contain low-density polyethylene.

[0037] Here, high density polyethylene has a strength of 942 kg / m 3 Medium density polyethylene refers to polyethylene with a density exceeding 925 kg / m 3 Super 942kg / m 3 Polyethylene having the following density: Low-density polyethylene can also be called high-pressure low-density polyethylene, and is a high-pressure ethylene homopolymer that can be obtained by a conventionally known high-pressure radical polymerization method. 3 It is polyethylene having the following density: Linear low-density polyethylene is a copolymer of ethylene and α-olefins polymerized using a multi-site catalyst such as a Ziegler-Natta catalyst or a single-site catalyst such as a metallocene catalyst, and has a density of 925 kg / m 3 It is polyethylene having the following density:

[0038] In the resin film of the present invention, the polyethylene content is preferably 29% by mass or less, more preferably 1% by mass or more and 28% by mass or less, and even more preferably 5% by mass or more and 26% by mass or less.

[0039] The polyethylene of the resin film may be fossil fuel polyethylene, biomass polyethylene, or a combination thereof. From the viewpoint of reducing the environmental load, the resin film of the present invention preferably contains biomass polyethylene. Biomass polyethylene will be described below.

[0040] <Biomass-derived ethylene> The method for producing biomass-derived ethylene, which is the raw material for biomass polyethylene, is not particularly limited, and it can be obtained by a conventionally known method. An example of a method for producing biomass-derived ethylene will be described below.

[0041] Biomass-derived ethylene can be produced using biomass-derived ethanol as a raw material. In particular, it is preferable to use biomass-derived fermented ethanol obtained from plant raw materials. The plant raw material is not particularly limited, and conventionally known plants can be used. Examples include corn, sugarcane, beet, and manioc.

[0042] Fermented ethanol derived from biomass refers to ethanol produced by contacting a culture solution containing a carbon source obtained from plant raw materials with an ethanol-producing microorganism or a product derived from its disruption, followed by purification. Ethanol can be purified from the culture solution by conventional methods such as distillation, membrane separation, and extraction. Examples of methods include adding benzene, cyclohexane, etc., followed by azeotropy, or removing water by membrane separation.

[0043] In order to obtain the above ethylene, further advanced purification may be carried out at this stage, for example, to reduce the total amount of impurities in the ethanol to 1 ppm or less.

[0044] A catalyst is usually used when obtaining ethylene by the dehydration reaction of ethanol, but the catalyst is not particularly limited and any conventionally known catalyst can be used. From the viewpoint of the process, a fixed-bed flow reaction is advantageous because it allows easy separation of the catalyst and the product, and for example, γ-alumina is preferred.

[0045] Since this dehydration reaction is an endothermic reaction, it is usually carried out under heated conditions. The heating temperature is not limited as long as the reaction proceeds at a commercially useful reaction rate, but is preferably 100°C or higher, more preferably 250°C or higher, and even more preferably 300°C or higher. There is no particular upper limit, but from the viewpoint of energy balance and equipment, it is preferably 500°C or lower, more preferably 400°C or lower.

[0046] In the dehydration reaction of ethanol, the yield of the reaction depends on the amount of water contained in the ethanol supplied as a raw material. Generally, when performing a dehydration reaction, it is preferable to eliminate water in order to improve the efficiency of water removal. However, in the case of ethanol dehydration using a solid catalyst, it has been found that the absence of water tends to increase the amount of other olefins, particularly butene, produced. This is presumably because the presence of a small amount of water is insufficient to suppress ethylene dimerization after dehydration. The allowable lower limit of the water content is 0.1% by mass or more, preferably 0.5% by mass or more. There are no particular limitations on the upper limit, but from the viewpoints of material balance and heat balance, it is preferably 50% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less.

[0047] By carrying out the dehydration reaction of ethanol in this manner, a mixture of ethylene, water, and a small amount of unreacted ethanol is obtained, but since ethylene is in a gaseous state at room temperature and below about 5 MPa, water and ethanol can be removed from this mixture by gas-liquid separation to obtain ethylene. This can be done by a known method.

[0048] The ethylene obtained by the gas-liquid separation is further distilled. The distillation method, operation temperature, residence time, etc. are not particularly limited, except that the operation pressure at this time must be atmospheric pressure or higher.

[0049] When biomass-derived ethanol is used as the raw material, the resulting ethylene contains trace amounts of impurities introduced during the ethanol fermentation process, such as carbonyl compounds (e.g., ketones, aldehydes, and esters) and their decomposition products (e.g., carbon dioxide), as well as nitrogen-containing compounds (e.g., amines and amino acids) and their decomposition products (e.g., ammonia), which are enzymatic decomposition products and contaminants. Depending on the intended use of ethylene, these trace amounts of impurities may be problematic, so they may be removed by purification. The purification method is not particularly limited, and conventionally known methods can be used. An example of a suitable purification procedure is adsorption purification. The adsorbent used is not particularly limited, and conventionally known adsorbents can be used. For example, a material with a high surface area is preferred, and the type of adsorbent is selected depending on the type and amount of impurities in the ethylene obtained by the dehydration reaction of biomass-derived ethanol.

[0050] A caustic water treatment may be used in combination as a method for purifying impurities in ethylene. When caustic water treatment is used, it is preferable to carry out the treatment before adsorption purification. In this case, it is necessary to carry out a water removal treatment after the caustic treatment and before adsorption purification.

[0051] <Biomass polyethylene> Biomass polyethylene is obtained by polymerizing a monomer containing ethylene derived from biomass. It is preferable to use the biomass-derived ethylene obtained by the above-mentioned manufacturing method. Since biomass-derived ethylene is used as the raw material monomer, the polyethylene obtained by polymerization is derived from biomass. As the biomass polyethylene, for example, biomass linear low-density polyethylene (trade name: SLL318, density: 918 kg / m) manufactured by Braskem is available. 3 , MFR: 2.7 g / 10 min, biomass content: 87%), Braskem biomass low-density polyethylene (trade name: SEB853, density: 923 kg / m 3 , MFR: 2.7 g / 10 min, biomass content: 95%), etc. The raw material monomer for polyethylene does not have to contain 100% by mass of biomass-derived ethylene.

[0052] As long as the object of the present invention is not impaired, the monomers that are raw materials for biomass polyethylene may further contain ethylene derived from fossil fuels.

[0053] In the present invention, the "biomass content" is expressed as the weight ratio of biomass-derived components.

[0054] Atmospheric carbon dioxide contains a certain proportion of C14 (105.5 pMC), and it is known that the C14 content in plants that grow by absorbing atmospheric carbon dioxide, such as corn, is also approximately 105.5 pMC. It is also known that fossil fuels contain very little C14. Therefore, the proportion of biomass-derived carbon can be calculated by measuring the proportion of C14 in the total carbon atoms. In the present invention, "biomass ratio" refers to the weight ratio of biomass-derived components. For example, in the case of polyethylene terephthalate, which is a polymer of ethylene glycol containing two carbon atoms and terephthalic acid containing eight carbon atoms in a 1:1 molar ratio, if only biomass-derived ethylene glycol is used, the weight ratio of biomass-derived components in the polyester is 31.25%, resulting in a theoretical biomass ratio of 31.25%. Specifically, the mass of polyethylene terephthalate is 192, of which the mass derived from biomass-derived ethylene glycol is 60, so 60 ÷ 192 × 100 = 31.25. Furthermore, the weight ratio of biomass-derived components in a fossil fuel-derived polyester produced using fossil fuel-derived ethylene glycol and fossil fuel-derived dicarboxylic acid is 0%, and the biomass content of the fossil fuel-derived polyester is 0%. Hereinafter, unless otherwise specified, "biomass content" refers to the weight ratio of biomass-derived components.

[0055] In the present invention, theoretically, if all biomass-derived ethylene is used as a raw material for polyethylene, the concentration of biomass-derived ethylene will be 100%, and the biomass content of biomass polyethylene will be 100%.Furthermore, the concentration of biomass-derived ethylene in fossil fuel polyethylene produced only from fossil fuel-derived raw materials will be 0%, and the biomass content of fossil fuel polyethylene will be 0%.

[0056] In the present invention, the biomass polyethylene or biomass-derived resin layer does not need to have a biomass content of 100%. This is because if even a part of the resin film uses biomass-derived raw materials, it is in line with the purpose of reducing the amount of fossil fuel used compared to conventional methods.

[0057] The present resin film preferably has a biomass ratio of 5% or more, which can further improve the reduction of environmental impact. The biomass ratio of the resin film is more preferably 5% or more and 90% or less, even more preferably 5% or more and 50% or less, and even more preferably 10% or more and 25% or less.

[0058] The thickness of the resin film of the present invention is preferably from 15 μm to 250 μm, more preferably from 20 μm to 200 μm, and even more preferably from 20 μm to 150 μm, which can further improve the sealability of the resin film.

[0059] In the resin film of the present invention, the thickness of the second layer is preferably equal to or greater than the thickness of the first layer. This improves the sealing and tearing properties of the resin film. The thickness ratio of the first layer to the second layer is preferably 1:8 to 1:1, and more preferably 1:5 to 1:1. Furthermore, when the resin film has a third layer, it is preferable that the thickness of the second layer is equal to or greater than the thickness of the third layer. This improves the interlayer lamination strength and tear resistance with the multilayer. The thickness ratio of the second layer to the third layer is preferably 8:1 to 1:1, and more preferably 5:1 to 1:1.

[0060] The resin film of the present invention preferably has a breaking elongation of 500% or more in one direction and in the other direction perpendicular to the one direction. The breaking elongation of the resin film of the present invention is measured in accordance with JIS K7127. Using a Tensilon universal material testing machine RTC-1310A (manufactured by A&D Co., Ltd.), the test piece is held for 1 minute in an environment at a temperature of 25°C and a relative humidity of 50%, and then measurement is performed under an environment at a temperature of 25°C and a relative humidity of 50%. Measurements are performed using rectangular test pieces with a side length of 15 mm and a direction perpendicular to the side length of 150 mm, with an initial gripping distance of 100 mm and a tensile speed of 300 mm / min. The length in the direction perpendicular to the side can be adjusted as long as the measurement can be performed with an initial gripping distance of 100 mm.

[0061] The breaking elongation (%) of the resin film in the machine direction (MD) is preferably 500% or more. The breaking elongation of the resin film in the machine direction (MD) is preferably 700% or more, more preferably 800% or more. Furthermore, the breaking elongation of the resin film in the transverse direction (TD) perpendicular to the machine direction is preferably 500% or more. The breaking elongation of the resin film in the transverse direction (TD) is preferably 700% or more, more preferably 800% or less, and even more preferably 900% or more.

[0062] The one direction mentioned above may be a direction different from the machine direction (MD) or the perpendicular direction (TD).

[0063] The first layer, second layer, third layer and thermoplastic resin layer will be described in detail below.

[0064] (1st layer) The first layer is composed of a resin composition containing polypropylene as a main component. This can improve the heat resistance and oil resistance of the resin film. In this specification, "containing polypropylene as a main component" and "being a main component" mean that the content exceeds 50% by mass. Examples of polypropylene include propylene-ethylene block copolymers, propylene-ethylene random copolymers, homopolypropylenes, and mixtures of two or more of these. From the viewpoint of seal strength, the resin composition constituting the first layer preferably contains a propylene-ethylene block copolymer, and from the viewpoint of low-temperature sealability, it preferably contains a propylene-ethylene random copolymer.

[0065] In the resin composition constituting the first layer, the polypropylene content is preferably 51% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more, which can further improve the heat resistance and oil resistance of the resin film.

[0066] The resin composition constituting the first layer may contain polyethylene. This can improve the tearability of the resin film. Examples of polyethylene include high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, and mixtures of two or more of these. From the viewpoint of sealability, the resin composition constituting the first layer preferably contains low-density polyethylene, linear low-density polyethylene, or mixtures of these.

[0067] When a mixture of polypropylene and polyethylene is used as the resin composition constituting the first layer, the resin composition constituting the first layer may have an island-sea structure. Here, the "island-sea structure" refers to a structure in which polyethylene is discontinuously dispersed within a continuous region of polypropylene. The island-sea structure can further improve the tearability of the resin film.

[0068] The resin composition constituting the first layer contains 20% by mass or less of polyethylene. This allows the resin film to have sealability. The polyethylene content in the resin composition constituting the first layer is preferably 15% by mass or less, and more preferably 10% by mass or less.

[0069] The polyethylene of the resin composition constituting the first layer may be fossil fuel polyethylene, biomass polyethylene, or a combination thereof. From the viewpoint of reducing the environmental load, the resin composition constituting the first layer preferably contains biomass polyethylene.

[0070] The resin composition constituting the first layer preferably has a biomass content of 50% or less. Resins obtained from biomass-derived raw materials have a higher proportion of low-molecular-weight components than resins obtained from fossil fuel-derived raw materials, and these low-molecular-weight components may affect the sealing properties of the resin film. Therefore, by setting the biomass content of the resin composition constituting the first layer to 50% or less, the effect on sealing properties can be reduced. From the viewpoints of reducing the environmental impact and sealing properties, the biomass content of the resin composition constituting the first layer is preferably 0.1% to 25% and more preferably 1% to 15%.

[0071] The resin composition constituting the first layer preferably has a melt flow rate (MFR) of 1 g / 10 min to 30 g / 10 min, more preferably 3 g / 10 min to 25 g / 10 min, and even more preferably 5 g / 10 min to 20 g / 10 min. The melt flow rate is a value measured by Method A in accordance with JIS K7210-2014 at a temperature of 190°C and a load of 21.18 N. If the resin composition constituting the first layer has an MFR of 1 g / 10 min or more, the extrusion load during molding can be reduced. Furthermore, if the resin composition constituting the first layer has an MFR of 30 g / 10 min or less, the mechanical strength of the resin film can be increased.

[0072] The thickness of the first layer is preferably 5 μm or more and 100 μm or less, more preferably 5 μm or more and 80 μm or less, and even more preferably 10 μm or more and 50 μm or less. This can further improve the sealing properties of the resin film. The first layer may also be composed of two or more layers.

[0073] The resin composition constituting the first layer may contain one or more additives such as antioxidants, antiblocking agents, lubricants, fillers, plasticizers, antistatic agents, UV absorbers, inorganic particles, organic particles, release agents, and dispersants, as long as the properties of the present invention are not impaired.

[0074] (2nd layer) The second layer is composed of a resin composition containing polypropylene as the main component and biomass polyethylene. The resin composition constituting the second layer contains polypropylene as the main component, thereby improving the heat resistance and oil resistance of the resin film. Furthermore, the resin composition constituting the second layer contains biomass polyethylene, thereby improving the environmental impact reduction and tearability of the resin film.

[0075] The resin composition constituting the second layer may have a sea-island structure, which can further improve the tearability of the resin film.

[0076] In the resin composition constituting the second layer, examples of the polypropylene include a propylene-ethylene block copolymer, a propylene-ethylene random copolymer, a homopolypropylene, and a mixture of two or more of these. From the viewpoint of seal strength, the resin composition constituting the second layer preferably contains a propylene-ethylene block copolymer, and from the viewpoint of low-temperature sealability, it preferably contains a propylene-ethylene random copolymer.

[0077] In the resin composition constituting the second layer, the polypropylene content is preferably 51% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, which can further improve the heat resistance and oil resistance of the resin film.

[0078] In the resin composition constituting the second layer, examples of biomass polyethylene include biomass high-density polyethylene, biomass medium-density polyethylene, biomass low-density polyethylene, biomass linear low-density polyethylene, and mixtures of two or more of these. From the viewpoint of tearability, the resin composition constituting the second layer preferably contains biomass low-density polyethylene.

[0079] The resin composition constituting the second layer preferably has a biomass ratio of 5% or more. This allows the resin film to further reduce its environmental impact. The biomass ratio of the resin composition constituting the second layer is more preferably 5% or more and 95% or less, and even more preferably 10% or more and 50% or less.

[0080] When the second layer constitutes the outermost layer of the resin film, the biomass content of the resin composition constituting the second layer is preferably 30% or less. Resins obtained from biomass-derived raw materials have a higher proportion of low-molecular-weight components than resins obtained from fossil fuel-derived raw materials, and these low-molecular-weight components may affect adhesion to other layers. By setting the biomass content of the resin composition constituting the second layer to 30% or less, it is possible to reduce the effect on adhesion to other layers. From the viewpoints of reducing environmental impact and adhesion, the biomass content of the resin composition constituting the second layer is preferably 1% or more and 27% or less, and more preferably 5% or more and 20% or less.

[0081] The resin composition constituting the second layer may contain fossil fuel polyethylene, such as fossil fuel high-density polyethylene, fossil fuel medium-density polyethylene, fossil fuel low-density polyethylene, fossil fuel linear low-density polyethylene, and mixtures of two or more of these, provided that the properties of the present invention are not impaired.

[0082] The polyethylene content in the resin composition constituting the second layer is 35% by mass or less. This allows for a resin film with film-forming properties. The polyethylene content in the resin composition constituting the second layer is preferably 5% by mass or more and 30% by mass or less, and more preferably 15% by mass or more and 30% by mass or less. This allows for improved tearability of the resin film.

[0083] The resin composition constituting the second layer preferably has a melt flow rate (MFR) of 1 g / 10 min to 30 g / 10 min, more preferably 3 g / 10 min to 25 g / 10 min, and even more preferably 5 g / 10 min to 20 g / 10 min. If the resin composition constituting the second layer has an MFR of 1 g / 10 min or more, the extrusion load during molding can be reduced. Furthermore, if the resin composition constituting the second layer has an MFR of 30 g / 10 min or less, the mechanical strength of the resin film can be increased.

[0084] The thickness of the second layer is preferably 10 μm or more and 150 μm or less, more preferably 15 μm or more and 120 μm or less, and even more preferably 20 μm or more and 100 μm or less. This can further improve the sealing properties of the resin film. The second layer may also be composed of two or more layers.

[0085] The resin composition constituting the second layer may contain one or more additives such as antioxidants, antiblocking agents, lubricants, fillers, plasticizers, antistatic agents, UV absorbers, inorganic particles, organic particles, release agents, and dispersants, as long as the properties of the present invention are not impaired.

[0086] (3rd layer) The third layer is composed of a resin composition containing polypropylene as a main component, thereby improving the heat resistance and oil resistance of the resin film. Examples of polypropylene include propylene-ethylene block copolymers, propylene-ethylene random copolymers, homopolypropylenes, and mixtures of two or more of these. From the viewpoint of seal strength, the resin composition constituting the third layer preferably contains a propylene-ethylene block copolymer, and from the viewpoint of low-temperature sealability, it preferably contains a propylene-ethylene random copolymer.

[0087] In the resin composition constituting the third layer, the polypropylene content is preferably 51% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more, which can further improve the heat resistance and oil resistance of the resin film.

[0088] In the resin film of the present invention, the difference between the polypropylene content in the resin film constituting the third layer and the polypropylene content in the resin film constituting the first layer is preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less, which can further reduce curling of the resin film.

[0089] The resin composition constituting the third layer may contain polyethylene, which can improve the tearability of the resin film. When the resin composition constituting the first layer contains polyethylene, examples of the polyethylene include high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, and mixtures of two or more of these.

[0090] When a mixture of polypropylene and polyethylene is used as the resin composition constituting the third layer, the resin composition constituting the third layer may have an island-sea structure, which can further improve the tearability of the resin film.

[0091] The resin composition constituting the third layer has a polyethylene content of 35% by mass or less. This allows for a resin film with film-forming properties. The polyethylene content in the resin composition constituting the third layer is preferably 1% by mass or more and 30% by mass or less, and more preferably 5% by mass or more and 25% by mass or less. This allows for improved tearability of the resin film.

[0092] The polyethylene of the resin composition constituting the third layer may be fossil fuel polyethylene, biomass polyethylene, or a combination thereof. From the viewpoint of reducing the environmental load, the resin composition constituting the third layer preferably contains biomass polyethylene.

[0093] When the third layer constitutes the outermost layer of the resin film, the biomass content of the resin composition constituting the third layer is preferably 30% or less. Resins obtained from biomass-derived raw materials have a higher proportion of low-molecular-weight components than resins obtained from fossil fuel-derived raw materials, and these low-molecular-weight components may affect adhesion with other layers. By setting the biomass content of the resin composition constituting the third layer to 30% or less, it is possible to reduce the effect on adhesion with other layers. From the viewpoints of reducing environmental impact and adhesion, the biomass content of the resin composition constituting the third layer is preferably 1% or more and 25% or less, and more preferably 5% or more and 20% or less.

[0094] The resin composition constituting the third layer preferably has a melt flow rate (MFR) of 1 g / 10 min to 30 g / 10 min, more preferably 3 g / 10 min to 25 g / 10 min, and even more preferably 5 g / 10 min to 20 g / 10 min. If the resin composition constituting the third layer has an MFR of 1 g / 10 min or more, the extrusion load during molding can be reduced. Furthermore, if the resin composition constituting the third layer has an MFR of 30 g / 10 min or less, the mechanical strength of the resin film can be increased.

[0095] The thickness of the third layer is preferably 5 μm or more and 100 μm or less, more preferably 5 μm or more and 80 μm or less, and even more preferably 10 μm or more and 50 μm or less. This allows for improved adhesion to other layers. The third layer may also be composed of two or more layers.

[0096] The resin composition constituting the third layer may contain one or more additives such as antioxidants, antiblocking agents, lubricants, fillers, plasticizers, antistatic agents, UV absorbers, inorganic particles, organic particles, release agents, and dispersants, as long as the properties of the present invention are not impaired.

[0097] (thermoplastic resin layer) The thermoplastic resin layer is a layer formed to bond any two layers together by lamination. The thermoplastic resin layer can be formed by a conventionally known method, for example, a melt extrusion lamination method or a sand lamination method. The thermoplastic resin layer can be made of a polyolefin resin such as a polyethylene resin or a polypropylene resin, a cyclic polyolefin resin, or a copolymer resin, modified resin, or mixture (including alloy) containing these resins as the main component. Examples of polyolefin resins include low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, polypropylene, ethylene-α-olefin copolymers polymerized using a metallocene catalyst, random or block copolymers of ethylene and polypropylene, ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methacrylic acid copolymer (EMAA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-maleic acid copolymer, and ionomer resins. To improve interlayer adhesion, acid-modified polyolefin resins can be used, which are modified with unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, and itaconic acid. Furthermore, resins obtained by graft-polymerizing or copolymerizing unsaturated carboxylic acids, unsaturated carboxylic anhydrides, or ester monomers with polyolefin resins can also be used. These materials can be used alone or in combination. Examples of cyclic polyolefin resins that can be used include cyclic polyolefins such as ethylene-propylene copolymers, polymethylpentene, polybutene, polynorbornene, etc. These resins can be used alone or in combination.

[0098] The thermoplastic resin layer may contain a resin obtained from a raw material derived from biomass, or may contain a resin obtained from a raw material derived from fossil fuel.

[0099] (Method of manufacturing resin film) The method for producing the resin film of the present invention is not particularly limited, and the film can be produced by a conventionally known method. The resin film is preferably produced by co-extrusion molding, and the co-extrusion molding is more preferably carried out by a T-die method or an inflation method. Hereinafter, an example of a method for producing a resin film by the T-die method and the inflation method will be described.

[0100] In the T-die method, the raw materials for the resin composition constituting the first layer and the raw materials for the resin composition constituting the second layer are dried, and then supplied to a melt extruder heated to a temperature above their melting points (Tm) to Tm + 70°C, where they are melted and co-extruded into a sheet from a T-die. The co-extruded sheet is then rapidly cooled and solidified on a rotating cooling drum or the like to form a resin film. As the melt extruder, a single screw extruder, a twin screw extruder, a vent extruder, a tandem extruder, etc. can be used depending on the purpose.

[0101] In the inflation method, the raw materials for the resin composition constituting the first layer and the raw materials for the resin composition constituting the second layer are first dried and then fed into a melt extruder heated to a temperature above their respective melting points (Tm) to Tm + 70°C. The materials are then melted and co-extruded into a cylindrical shape through an annular die. Air is then forced into the cylindrical molten resin from below to expand the cylinder to a predetermined diameter, and cooling air is also forced into the outside of the cylinder from below. This expanded cylindrical body is called a bubble. The bubble is then folded into a film shape using guide plates and pinch rolls and wound up in a winding section. The folded film can be wound up as is, or both ends of the cylinder can be removed using a slitter or the like, separated into two films, and then wound up separately. This process allows the resin film to be formed. As the melt extruder, a single screw extruder, a twin screw extruder, a vent extruder, a tandem extruder, etc. can be used depending on the purpose.

[0102] Laminate Next, the laminate 20 of the present invention will be described. The laminate 20 includes at least one biaxially stretched plastic film and the above-mentioned resin film 10. By including the above-mentioned resin film 10, the laminate can have reduced environmental impact, as well as sealability and excellent tearability.

[0103] Fig. 7 is a cross-sectional view showing an example of a laminate 20 of the present invention. As shown in Fig. 7, the laminate 20 includes, in this order, a first biaxially oriented plastic film 21, a printed layer 22, a first adhesive layer 23, and the resin film 10. The first biaxially oriented plastic film 21 forms an outer surface 20y of the laminate 20, and the resin film 10 forms an inner surface 20x.

[0104] Fig. 8 is a cross-sectional view showing an example of a laminate 20 of the present invention. As shown in Fig. 8, the laminate 20 includes, in this order, a first biaxially oriented plastic film 21, a printed layer 22, a first adhesive layer 23, a second biaxially oriented plastic film 24, a second adhesive layer 25, and the resin film 10. The first biaxially oriented plastic film 21 forms an outer surface 20y of the laminate 20, and the resin film 10 forms an inner surface 20x.

[0105] Fig. 9 is a cross-sectional view showing another example of a laminate 20 of the present invention. As shown in Fig. 9, the laminate 20 includes, in this order, a first biaxially oriented plastic film 21, a printed layer 22, a first adhesive layer 23, a metal foil 26, a second adhesive layer 25, and the resin film 10. The first biaxially oriented plastic film 21 forms an outer surface 20y of the laminate 20, and the resin film 10 forms an inner surface 20x.

[0106] Fig. 10 is a cross-sectional view showing another example of the laminate 20 of the present invention. As shown in Fig. 4, the laminate 20 includes, in this order, a first biaxially oriented plastic film 21, a printed layer 22, a first adhesive layer 23, a vapor-deposited layer 27, a second biaxially oriented plastic film 24, a second adhesive layer 25, and the resin film 10. The first biaxially oriented plastic film 21 forms the outer surface 20y of the laminate 20, and the resin film 10 forms the inner surface 20x.

[0107] Fig. 11 is a cross-sectional view showing another example of the laminate 20 of the present invention. As shown in Fig. 5, the laminate 20 includes, in this order, a first biaxially oriented plastic film 21, a printed layer 22, a first anchor coat layer 28, a first adhesive resin layer 29, a vapor-deposited layer 27, a second biaxially oriented plastic film 24, a second anchor coat layer 30, a second adhesive resin layer 31, and the resin film 10. The first biaxially oriented plastic film 21 forms the outer surface 20y of the laminate 20, and the resin film 10 forms the inner surface 20x.

[0108] Below, the first biaxially oriented plastic film 21, the second biaxially oriented plastic film 24, the printed layer 22, the metal foil 26, the vapor deposition layer 27, the first adhesive layer 23, the second adhesive layer 25, the first anchor coat layer 28, the second anchor coat layer 30, the first adhesive resin layer 29, and the second adhesive resin layer 31 will each be described in detail.

[0109] (First biaxially stretched plastic film and second biaxially stretched plastic film) Examples of resin materials that can be used to form the first biaxially oriented plastic film and the second biaxially oriented plastic film include polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), 1,4-polycyclohexylene dimethylene terephthalate, and terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer; polyamides such as nylon 6 and nylon 6,6; polyolefins such as polyethylene, polypropylene, and polymethylpentene; vinyl resins such as polyvinyl chloride, polyvinyl alcohol (PVA), polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, and polyvinylpyrrolidone (PVP); (meth)acrylic resins such as polyacrylate, polymethacrylate, and polymethyl methacrylate; cellulose resins such as cellophane, cellulose acetate, nitrocellulose, cellulose acetate propionate (CAP), and cellulose acetate butyrate (CAB); styrene resins such as polystyrene (PS), and chlorinated resins thereof. Among these, polyolefin, polyester and polyamide are preferred, and polypropylene, polyethylene terephthalate, nylon 6 and nylon 6,6 are more preferred. In the present invention, "(meth)acrylic" means to include both "acrylic" and "methacrylic", and "(meth)acrylate" means to include both "acrylate" and "methacrylate".

[0110] As long as the properties of the present invention are not impaired, the first biaxially oriented plastic film and the second biaxially oriented plastic film may contain additives such as fillers, plasticizers, antistatic agents, ultraviolet absorbers, inorganic particles, organic particles, release agents, and dispersants.

[0111] (Printing layer) The printing layer is a layer printed on the first biaxially oriented plastic film to display product information and add aesthetic appeal to the bag. The printing layer displays letters, numbers, symbols, figures, pictures, etc. Gravure printing inks and flexographic printing inks can be used as materials for the printing layer.

[0112] The ink that constitutes the printing layer contains a binder and a pigment. The binder, like the first and second adhesive layers, contains, for example, polyurethane. Polyurethane is a cured product produced by reacting a polyol as the base resin with an isocyanate compound as the curing agent. Details of the polyol and isocyanate compound are described in the sections on the first and second adhesive layers.

[0113] The pigment in the printing layer is a colored powder that exists in the binder at a predetermined distribution density. The color of the pigment is not particularly limited, and various pigments such as red, blue, green, white, and black can be used. For example, the average particle size of the pigment may be 0.1 μm or more and 1 μm or less, or 0.5 μm or more and 1 μm or less. Note that white pigments generally have larger dimensions than pigments of other colors. For example, the average particle size of white pigments is 0.5 μm or more and 1 μm or less. The average particle size of the pigment can be measured by dynamic light scattering.

[0114] The printing layer may consist of a single layer or may include multiple layers. For example, the printing layer may include a first layer containing a pigment that exhibits a first color and a second layer containing a pigment that exhibits a second color different from the first color. The thickness of one printing layer is, for example, 0.5 μm or more and 3 μm or less.

[0115] (metal foil) As the metal foil, a conventionally known metal foil can be used. Aluminum foil is preferred from the viewpoints of gas barrier properties that prevent the transmission of oxygen gas, water vapor, etc., and light blocking properties that prevent the transmission of visible light, ultraviolet light, etc. The thickness of the metal foil is, for example, 5 μm or more and 15 μm or less.

[0116] (deposited layer) The vapor-deposited layer is a layer provided to enhance the gas barrier properties of the bag. The vapor-deposited layer comprises a vapor-deposited film of one or more inorganic substances or inorganic oxides, such as silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti), lead (Pb), zirconium (Zr), and yttrium (Y). The vapor-deposited layer may comprise one or more vapor-deposited films.

[0117] The vapor-deposited film can be formed by vapor-depositing the inorganic substance or inorganic oxide on one side of the biaxially stretched plastic film, etc. Examples of methods for forming the vapor-deposited film include known methods such as vacuum vapor deposition, sputtering, and chemical vapor deposition.

[0118] The thickness of the vapor-deposited film of the inorganic substance or inorganic oxide is 100 Å to 2000 Å, preferably 200 Å to 1000 Å.

[0119] In order to enhance the gas barrier property of the vapor-deposited layer, a gas barrier coating film may be provided on the vapor-deposited film of the inorganic substance or inorganic oxide as described above. 1 n M(OR 2 ) m (wherein, R 1 , R 2 represents an organic group having 1 to 8 carbon atoms, M represents a metal atom, n represents an integer of 0 or more, m represents an integer of 1 or more, and n+m represents the valence of M. The transparent gas barrier composition contains at least one alkoxide represented by the formula (I) and the polyvinyl alcohol resin and / or ethylene-vinyl alcohol copolymer as described above, and is further polycondensed by a sol-gel method in the presence of a sol-gel catalyst, an acid, water, and an organic solvent.

[0120] (First adhesive layer and second adhesive layer) The adhesive layers, such as the first adhesive layer and the second adhesive layer, contain an adhesive for bonding a first biaxially oriented plastic film, a second biaxially oriented plastic film, etc. to each other. The adhesive constituting the adhesive layer is produced from an adhesive composition prepared by mixing a first composition containing a base agent and a solvent with a second composition containing a curing agent and a solvent. Specifically, the adhesive contains a cured product produced by reaction of the base agent and the solvent in the adhesive composition.

[0121] Examples of adhesives include ether-based two-component reactive adhesives and ester-based two-component reactive adhesives. An example of an ether-based two-component reactive adhesive is polyether polyurethane. Polyether polyurethane is a cured product produced by reacting a polyether polyol as a base material with an isocyanate compound as a curing agent. Examples of ester-based two-component reactive adhesives include polyester polyurethane and polyester. Polyester polyurethane is a cured product produced by reacting a polyester polyol as a base material with an isocyanate compound as a curing agent.

[0122] Isocyanate compounds that react with polyols such as polyether polyols and polyester polyols to produce cured products include aromatic isocyanate compounds and aliphatic isocyanate compounds. Among these, aromatic isocyanate compounds leach out components that are unsuitable for food applications under high-temperature conditions, such as during heat sterilization (retort processing). As shown in FIGS. 7 to 11, the adhesive layer contacts the resin film 10 that forms the inner surface 20x of the laminate 20. Therefore, if the adhesive layer contains an aromatic isocyanate compound, components leached from the aromatic isocyanate compound may adhere to the contents of the bag 40 formed from the laminate 20.

[0123] In consideration of these issues, the adhesive layer is made of a cured product produced by the reaction of a polyol as the base agent with an aliphatic isocyanate compound as the curing agent. This prevents the adhesive layer from contaminating the contents with ingredients that are unsuitable for food applications. Examples of aliphatic isocyanates include hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI).

[0124] Furthermore, drop impact resistance can be improved by increasing the molar ratio of the isocyanate groups of the aliphatic isocyanate compound to the hydroxy groups of the polyol. For example, the molar ratio of the curing agent (aliphatic isocyanate compound) to the hydroxy groups of the base agent (polyol) has conventionally been about 3. In this embodiment, the molar ratio of the isocyanate groups of the aliphatic isocyanate compound to the hydroxy groups of the polyol is preferably 3.5 or more, more preferably 4 or more, and even more preferably 4.5 or more. More preferably, the molar ratio of the isocyanate groups of the aliphatic isocyanate compound to the hydroxy groups of the polyol is greater than 5.

[0125] On the other hand, aliphatic isocyanate compounds are expensive, and increasing the amount of aliphatic isocyanate compounds is undesirable in terms of production costs. Furthermore, the higher the molar ratio of isocyanate groups in the aliphatic isocyanate compound to hydroxy groups in the polyol, the higher the temperature or the longer the time required to cure the adhesive composition. Taking these points into consideration, the molar ratio of aliphatic isocyanate groups to hydroxy groups is preferably 7 or less, and more preferably 6 or less.

[0126] The adhesive layer is formed by applying an adhesive composition to a first biaxially oriented plastic film, a second biaxially oriented plastic film, a metal foil, or a resin film, and then drying the adhesive composition and curing the adhesive composition through a reaction between the main agent and the solvent in the adhesive composition. In this embodiment, the weight per unit area of ​​the adhesive composition after drying is, for example, 2 g / m 2 More than 5g / m 2 It is preferable that the density is 3 g / m or less. 2 More than 4g / m 2 The thickness of the adhesive layer 60 is preferably 2 μm or more and 5 μm or less, and more preferably 3 μm or more and 4 μm or less.

[0127] (First adhesive resin layer and second adhesive resin layer) The adhesive resin layers, such as the first adhesive resin layer and the second adhesive resin layer, contain a thermoplastic resin for bonding the first biaxially oriented plastic film, the second biaxially oriented plastic film, etc. The adhesive resin layer is formed by a melt extrusion lamination method using a thermoplastic resin. The thermoplastic resin that can be used for the adhesive resin layer can be the same as the material for the thermoplastic resin layer described above.

[0128] (First anchor coat layer and second anchor coat layer) Anchor coat layers, such as the first and second anchor coat layers, are formed to improve the adhesion of the adhesive resin layer. The anchor coat layer can be formed by applying an anchor coat agent to the surface of the layer to be laminated and drying it. Examples of anchor coat agents include anchor coat agents made of any resin with a heat resistance temperature of 135°C or higher, such as vinyl-modified resins, epoxy resins, urethane resins, and polyester resins. In particular, anchor coat agents made of polyacrylic or polymethacrylic resins with two or more hydroxyl groups in their structure and an isocyanate compound as a curing agent are preferred. A silane coupling agent may also be used as an additive, and soluble nitrocellulose may also be used to enhance heat resistance.

[0129] (Specific examples of layer structure of laminate) Specific examples of the laminate 20 shown in Figures 7 to 11 are shown below. Note that " / " represents the boundary between layers. The leftmost layer is the layer that forms the outer surface 20y of the laminate 20, and the rightmost layer is the layer that forms the inner surface 20x of the laminate 20. Furthermore, "biaxially oriented PET film" means biaxially oriented polyethylene terephthalate film, "biaxially oriented PP film" means biaxially oriented polypropylene film, and "AC" means anchor coat layer. (1) Biaxially oriented PET film / printing layer / adhesive layer / resin film (2) Biaxially oriented PET film / printing layer / adhesive layer / biaxially oriented nylon film / adhesive layer / resin film (3) Biaxially oriented PET film / printing layer / adhesive layer / biaxially oriented PET film / adhesive layer / resin film (4) Biaxially oriented PET film / printing layer / adhesive layer / metal foil / adhesive layer / resin film (5) Biaxially oriented PET film / printed layer / adhesive layer / vapor deposition layer / biaxially oriented PET film / adhesive layer / resin film (6) Biaxially oriented polypropylene film / printed layer / AC / adhesive resin layer / vapor deposition layer / biaxially oriented PET film / AC / adhesive resin layer / resin film

[0130] (Method of manufacturing laminate) The method for producing the laminate is not particularly limited, and it can be produced by a conventionally known method such as dry lamination, melt extrusion lamination, or sand lamination.

[0131] bag Next, a bag 40 of the present invention will be described. Figure 12 is a front view showing bag 40 according to this embodiment. Bag 40 has a storage section 40a that stores contents. The configuration of bag 40 will be described below.

[0132] Bag 40 includes an upper portion 41, a lower portion 42, and a side portion 43, and has a generally rectangular outline in a front view. Note that names such as "upper portion," "lower portion," and "side portion," as well as terms such as "above" and "below," merely describe the relative positions and directions of bag 40 and its components. The position, etc., of bag 40 during transportation or use is not limited by the names and terms used in this specification.

[0133] 12, the bag 40 includes a surface film 44 that forms the surface and a back film 45 that forms the back. The surface film 44 and the back film 45 are each made of the laminate 20 described above.

[0134] The terms "surface film" and "back film" mentioned above merely demarcate the respective films according to their positional relationships, and the terms do not limit the method of providing the films when manufacturing bag 40. For example, bag 40 may be manufactured using a single film in which surface film 44 and back film 45 are continuously provided.

[0135] The inner surfaces of the front film 44 and the back film 45 are joined together by a seal portion. In the front view of the bag 40 shown in Figure 12, the seal portion is hatched.

[0136] As shown in Figure 12, the seal portion has an outer edge seal portion that extends along the outer edge of bag 40. The outer edge seal portion includes an upper seal portion 41a that extends along upper portion 41, a lower seal portion 42a that extends to lower portion 42, and a pair of side seal portions 43a that extend along a pair of side portions 43. Before being filled with contents (a state in which no contents are filled), bag 40 has an opening (not shown) formed in upper portion 41 of bag 40. After the contents are placed in bag 40, the inner surfaces of front film 44 and back film 45 are joined at upper portion 41 to form upper seal portion 41a and seal bag 40.

[0137] The upper seal portion 41 a, the lower seal portion 42 a, and the side seal portion 43 a are seal portions formed by joining the inner surface of the front film 44 and the inner surface of the back film 45 together.

[0138] There are no particular limitations on the method for forming the seal portion, as long as it is possible to join opposing films together and seal bag 40. For example, the seal portion may be formed by melting the inner surfaces of the films by heating or the like and welding the inner surfaces together, i.e., by heat sealing.

[0139] (Easy-to-open means) The front film 44 and the back film 45 may be provided with easy-open means 47 for tearing the front film 44 and the back film 45 to open the bag 40. For example, as shown in Fig. 12, the easy-open means 46 may include a notch 47 formed in the side seal portion 43a of the bag 40, which serves as a tearing starting point. Alternatively, the easy-open means 46 may be a half-cut line formed by laser processing, a cutter, or the like, in a portion that serves as a path for tearing the bag 40.

[0140] Furthermore, although not shown, the easy-open means 46 may include a group of cuts or scars formed in the area where the seal portion is formed of the front film 44 and the back film 45. The group of scars may include, for example, a plurality of through holes formed so as to penetrate the front film 44 and / or the back film 45. Alternatively, the group of scars may include a plurality of holes formed on the outer surface of the front film 44 and / or the back film 45 so as not to penetrate the front film 44 and / or the back film 45.

[0141] (Bag manufacturing method) First, a surface film 44 and a back film 45 made of the laminate 20 described above are prepared. Next, the inner surfaces of each film are heat-sealed to form seals such as a bottom seal 42a and a side seal 43a. The films joined together by heat sealing are then cut into an appropriate shape to obtain the bag 40 shown in FIG. 12. Next, contents are filled into the bag 40 through an opening (not shown) in the top 41. The contents are, for example, chocolate. The top 41 is then heat-sealed to form the top seal 41a. In this manner, a bag 40 containing and sealed with contents can be obtained.

[0142] Other Aspects Another aspect of the present invention is a resin film having at least two layers, a first layer and a second layer, wherein the first layer and the second layer are laminated directly or via a thermoplastic resin layer, the first layer constitutes the innermost layer of the resin film, the resin film contains polypropylene and polyethylene, the resin composition constituting the first layer contains polypropylene as a main component, the polyethylene content of the first layer is 20% by mass or less, and the resin composition constituting the second layer contains polypropylene as a main component and biomass polyethylene, the polyethylene content of the second layer is 35% by mass or less. In another aspect of the resin film of the present invention, the resin film further comprises a third layer, which is laminated to the second layer directly or via a thermoplastic resin layer, and the resin composition constituting the third layer contains polypropylene as a main component, and the polyethylene content of the third layer may be 35 mass% or less. In the resin film according to another embodiment of the present invention, the biomass content may be 5% or more. In the resin film according to another embodiment of the present invention, the layer constituting the outermost layer of the resin film may have a biomass content of 30% or less. In the resin film according to another embodiment of the present invention, the polypropylene content may be 66% by mass or more. In the resin film according to another embodiment of the present invention, the elongation at break in one direction and in another direction perpendicular to the one direction may each be 500% or more. Another aspect of the present invention is a laminate comprising at least one biaxially oriented plastic film and a resin film according to another aspect of the present invention. Another aspect of the invention is a bag comprising a laminate according to another aspect of the invention. [Example]

[0143] Next, the present invention will be explained in more detail with reference to examples. However, the present invention is not limited to the following examples as long as it does not depart from the gist of the present invention.

[0144] [Example 1-1] The raw material of the resin composition constituting the first layer was a propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 , biomass content: 0%) was melted. Next, as a raw material for the resin composition constituting the second layer, 85 parts by mass of propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3, biomass content: 0%), and 15 parts by mass of biomass linear low-density polyethylene (manufactured by Braskem, product name: SLL-318, MFR: 2.7 g / 10 min, density: 918 kg / m 3 (Biomass content: 87%) was melted separately. These melts were co-extruded through a T-die to produce an unstretched resin film with a layer thickness ratio of 1:4 (first layer:second layer) and a thickness of 50 μm. The polypropylene content in the resin film was 88 mass %, and the biomass content of the resin film was 10%.

[0145] Next, a 12 μm thick biaxially oriented polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., product name: E5100) was prepared as the first biaxially oriented plastic film 21. Subsequently, a printed layer 22 was formed on this first biaxially oriented plastic film 21. The thickness of the printed layer 22 was 1.0 μm. Furthermore, a 12 μm thick biaxially oriented polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., product name: E5100) was prepared as the second biaxially oriented plastic film 24.

[0146] Next, a first biaxially oriented plastic film 21, a printed layer 22, a first adhesive layer 23, a second biaxially oriented plastic film 24, a second adhesive layer 25, and a resin film 10 were laminated in this order by dry lamination to produce a laminate 20 as shown in FIG. 8. A two-component polyurethane adhesive (main agent: RU-40, curing agent: H-4) manufactured by Rock Paint Co., Ltd. was used for the first adhesive layer 23 and the second adhesive layer 25. The main agent, RU-40, is a polyester polyol. The thicknesses of the first adhesive layer 23 and the second adhesive layer 25 were each 3.0 μm. In the laminate 20, the first layer of the resin film 10 constitutes the innermost layer.

[0147] Next, the bag 40 shown in Fig. 12 was produced. Specifically, first, a surface film 44 and a back surface film 45 were produced from the obtained laminate 20. Next, the surface film 44 and the back surface film 45 were overlapped so that the resin film 10 of the surface film 44 and the resin film 10 of the back surface film 45 were in contact with each other.

[0148] Then, an upper sealed portion 41a, a lower sealed portion 42a, and a side sealed portion 43a were formed by heat sealing according to the shape of each bag 40. The heat sealing was carried out under the following conditions. (Heat sealing conditions) Heat sealing device: Heat sealer (Tester Sangyo Co., Ltd., product name: TP-701-A) Heat sealing temperature: 200℃, 190℃, 180℃, 170℃, 160℃, 150℃ Heat sealing pressure: 0.1MPa Heat sealing time: 1 second

[0149] Next, the heat-sealed area was cut to fit the shape of each bag 40, thereby producing the bags 40 shown in Fig. 14. Furthermore, notches 47 were formed in the produced bags 40 as easy-open means 46.

[0150] The produced bag 40 had a height S1 (see FIG. 12) of 140 mm, a width S2 of 120 mm, and widths S3 of upper sealed portion 41a, width S4 of lower sealed portion 42a, and width S5 of side sealed portion 43a of 5.0 mm.

[0151] [Example 1-2] The raw material for the resin composition constituting the second layer was 80 parts by mass of a propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 , biomass content: 0%), and 20 parts by mass of biomass linear low-density polyethylene (manufactured by Braskem, product name: SLL-318, MFR: 2.7 g / 10 min, density: 918 kg / m 3 A resin film was produced in the same manner as in Example 1-1, except that a polypropylene film having a biomass ratio of 87% was used. The layer thickness ratio was 1:4 (first layer:second layer), and the thickness of the resin film was 50 μm. The polypropylene content in the resin film was 84% ​​by mass, and the biomass ratio of the resin film was 14%. Furthermore, using the obtained resin film, a laminate and a bag were produced in the same manner as in Example 1-1.

[0152] [Examples 1-3] The raw material for the resin composition constituting the second layer was 70 parts by mass of a propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 , biomass content: 0%), and 30 parts by mass of biomass linear low-density polyethylene (manufactured by Braskem, product name: SLL-318, MFR: 2.7 g / 10 min, density: 918 kg / m 3 A resin film was produced in the same manner as in Example 1-1, except that a polypropylene film having a biomass ratio of 87% was used. The layer thickness ratio was 1:4 (first layer:second layer), and the thickness of the resin film was 50 μm. The polypropylene content in the resin film was 76% by mass, and the biomass ratio of the resin film was 21%. Furthermore, using the obtained resin film, a laminate and a bag were produced in the same manner as in Example 1-1.

[0153] [Examples 1-4] The raw material of the resin composition constituting the first layer was 90 parts by mass of a propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 , biomass content: 0%), and 10 parts by mass of biomass linear low-density polyethylene (manufactured by Braskem, product name: SLL-318, MFR: 2.7 g / 10 min, density: 918 kg / m 3 The raw material for the resin composition constituting the second layer was 70 parts by mass of a propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 , biomass content: 0%), and 30 parts by mass of biomass linear low-density polyethylene (manufactured by Braskem, product name: SLL-318, MFR: 2.7 g / 10 min, density: 918 kg / m 3A resin film was produced in the same manner as in Example 1-1, except that a polypropylene film having a biomass ratio of 87% was used. The layer thickness ratio was 1:4 (first layer:second layer), and the thickness of the resin film was 50 μm. The polypropylene content in the resin film was 74% by mass, and the biomass ratio of the resin film was 23%. Furthermore, using the obtained resin film, a laminate and a bag were produced in the same manner as in Example 1-1.

[0154] [Examples 1-5] The raw material for the resin composition constituting the second layer was 85 parts by mass of propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 , biomass content: 0%), and 15 parts by mass of biomass low-density polyethylene (manufactured by Braskem, product name: SEB-853, MFR: 2.7 g / 10 min, density: 923 kg / m 3 A resin film was produced in the same manner as in Example 1-1, except that a polypropylene film having a biomass ratio of 95% was used. The layer thickness ratio was 1:4 (first layer:second layer), and the thickness of the resin film was 50 μm. The polypropylene content in the resin film was 88% by mass, and the biomass ratio of the resin film was 11%. Furthermore, using the obtained resin film, a laminate and a bag were produced in the same manner as in Example 1-1.

[0155] [Examples 1-6] The raw material for the resin composition constituting the second layer was 70 parts by mass of a propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 , biomass content: 0%), and 30 parts by mass of biomass low-density polyethylene (manufactured by Braskem, product name: SEB-853, MFR: 2.7 g / 10 min, density: 923 kg / m 3A resin film was produced in the same manner as in Example 1-1, except that a polypropylene film having a biomass ratio of 95% was used. The layer thickness ratio was 1:4 (first layer:second layer), and the thickness of the resin film was 50 μm. The polypropylene content in the resin film was 76% by mass, and the biomass ratio of the resin film was 23%. Furthermore, using the obtained resin film, a laminate and a bag were produced in the same manner as in Example 1-1.

[0156] [Examples 1-7] The raw materials for the resin composition constituting the second layer were 70 parts by mass of a propylene-ethylene block copolymer (manufactured by Prime Polymer Co., Ltd., product name: J715M, MFR: 9.0 g / 10 min, biomass content: 0%) and 30 parts by mass of a biomass linear low-density polyethylene (manufactured by Braskem, product name: SLL-318, MFR: 2.7 g / 10 min, density: 918 kg / m). 3 A resin film was produced in the same manner as in Example 1-1, except that a polypropylene film having a biomass ratio of 87% was used. The layer thickness ratio was 1:4 (first layer:second layer), and the thickness of the resin film was 50 μm. The polypropylene content in the resin film was 76% by mass, and the biomass ratio of the resin film was 21%. The configuration of the resin film of this example is shown in Table 1. Furthermore, using the obtained resin film, a laminate and a bag were produced in the same manner as in Example 1-1.

[0157] [Comparative Example 1-1] Propylene-ethylene random copolymer (Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 Only the resin (biomass content: 0%) was melted, and the melt was extruded through a T-die to produce an unstretched resin film with a thickness of 50 μm. Furthermore, using the obtained resin film, a laminate and a bag were produced in the same manner as in Example 1-1.

[0158] [Comparative Example 1-2] Only the propylene-ethylene block copolymer (manufactured by Prime Polymer Co., Ltd., product name: J715M, MFR: 9.0 g / 10 min, biomass content: 0%) was melted, and the melt was extruded through a T-die to produce an unstretched resin film with a thickness of 50 μm. Furthermore, using the obtained resin film, a laminate and a bag were produced in the same manner as in Example 1-1.

[0159] [Comparative Example 1-3] The raw material for the resin composition constituting the first layer was 70 parts by mass of a propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 , biomass content: 0%), and 30 parts by mass of biomass linear low-density polyethylene (manufactured by Braskem, product name: SLL-318, MFR: 2.7 g / 10 min, density: 918 kg / m 3 The raw material for the resin composition constituting the second layer was 70 parts by mass of a propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 , biomass content: 0%), and 30 parts by mass of biomass linear low-density polyethylene (manufactured by Braskem, product name: SLL-318, MFR: 2.7 g / 10 min, density: 918 kg / m 3 A resin film was produced in the same manner as in Example 1-1, except that a polypropylene film having a biomass ratio of 87% was used. The layer thickness ratio was 1:4 (first layer:second layer), and the thickness of the resin film was 50 μm. The polypropylene content in the resin film was 70 mass %, and the biomass ratio of the resin film was 26%. Furthermore, using the obtained resin film, a laminate and a bag were produced in the same manner as in Example 1-1.

[0160] [Comparative Example 1-4] The raw material of the resin composition constituting the first layer was a propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m3 , biomass content: 0%) was melted. Next, as a raw material for the resin composition constituting the second layer, 60 parts by mass of propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 , biomass content: 0%), and 40 parts by mass of biomass linear low-density polyethylene (manufactured by Braskem, product name: SLL-318, MFR: 2.7 g / 10 min, density: 918 kg / m 3 (Biomass content: 87%) was melted separately. These melts were co-extruded using a T-die, but the resin composition could not be formed into a film.

[0161] Details of each layer and resin film in Examples 1-1 to 1-7 and Comparative Examples 1-1 to 1-4 are shown in Tables 1 and 2. In Table 1, "petroleum-based random PP" means a propylene-ethylene random copolymer, "petroleum-based block PP" means a propylene-ethylene block copolymer, "bio-LLDPE" means a biomass linear low-density polyethylene, and "bio-LDPE" means a biomass low-density polyethylene. All contents in Tables 1 and 2 are based on mass.

[0162] [Table 1]

[0163] [Table 2]

[0164] [Example 2-1] The raw material of the resin composition constituting the first layer was a propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 , biomass content: 0%) was melted. Next, as a raw material for the resin composition constituting the second layer, 80 parts by mass of propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 , biomass content: 0%), and 20 parts by mass of biomass linear low-density polyethylene (manufactured by Braskem, product name: SLL-318, MFR: 2.7 g / 10 min, density: 918 kg / m 3 (Biomass content: 87%) was melted separately. Next, as the raw material of the resin composition constituting the third layer, a propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 (Biomass content: 0%) was melted separately. These melts were co-extruded through a T-die to produce an unstretched resin film with a layer thickness ratio of 1:3:1 (1st layer:2nd layer:3rd layer) and a thickness of 50 μm. The polypropylene content in the resin film was 88 mass %, and the biomass content of the resin film was 10%.

[0165] Next, a 12 μm thick biaxially oriented polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., product name: E5100) was prepared as the first biaxially oriented plastic film 21. Subsequently, a printed layer 22 was formed on this first biaxially oriented plastic film 21. The thickness of the printed layer 22 was 1.0 μm. Furthermore, a 12 μm thick biaxially oriented polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., product name: E5100) was prepared as the second biaxially oriented plastic film 24.

[0166] Next, a first biaxially oriented plastic film 21, a printed layer 22, a first adhesive layer 23, a second biaxially oriented plastic film 24, a second adhesive layer 25, and a resin film 10 were laminated in this order by dry lamination to produce a laminate 20 as shown in FIG. 8. A two-component polyurethane adhesive (main agent: RU-40, curing agent: H-4) manufactured by Rock Paint Co., Ltd. was used for the first adhesive layer 23 and the second adhesive layer 25. The main agent, RU-40, is a polyester polyol. The thicknesses of the first adhesive layer 23 and the second adhesive layer 25 were each 3.0 μm. In the laminate 20, the first layer of the resin film 10 constitutes the innermost layer.

[0167] Next, the bag 40 shown in Fig. 12 was produced. Specifically, first, a surface film 44 and a back surface film 45 were produced from the obtained laminate 20. Next, the surface film 44 and the back surface film 45 were overlapped so that the resin film 10 of the surface film 44 and the resin film 10 of the back surface film 45 were in contact with each other.

[0168] Then, an upper sealed portion 41a, a lower sealed portion 42a, and a side sealed portion 43a were formed by heat sealing according to the shape of each bag 40. The heat sealing was carried out under the following conditions. (Heat sealing conditions) Heat sealing device: Heat sealer (Tester Sangyo Co., Ltd., product name: TP-701-A) Heat sealing temperature: 200℃, 190℃, 180℃, 170℃, 160℃, 150℃ Heat sealing pressure: 0.1MPa Heat sealing time: 1 second

[0169] Next, the heat-sealed area was cut to fit the shape of each bag 40, thereby producing the bags 40 shown in Fig. 14. Furthermore, notches 47 were formed in the produced bags 40 as easy-open means 46.

[0170] The produced bag 40 had a height S1 (see FIG. 12) of 140 mm, a width S2 of 120 mm, and widths S3 of upper sealed portion 41a, width S4 of lower sealed portion 42a, and width S5 of side sealed portion 43a of 5.0 mm.

[0171] [Example 2-2] The raw material for the resin composition constituting the second layer was 70 parts by mass of a propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 , biomass content: 0%), and 30 parts by mass of biomass linear low-density polyethylene (manufactured by Braskem, product name: SLL-318, MFR: 2.7 g / 10 min, density: 918 kg / m 3 A resin film was produced in the same manner as in Example 2-1, except that a polypropylene film having a biomass ratio of 87% was used. The layer thickness ratio was 1:3:1 (first layer:second layer:third layer), and the thickness of the resin film was 50 μm. The polypropylene content in the resin film was 82 mass%, and the biomass ratio of the resin film was 16%. Furthermore, using the obtained resin film, a laminate and a bag were produced in the same manner as in Example 2-1.

[0172] [Example 2-3] The raw material of the resin composition constituting the first layer was 90 parts by mass of a propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 , biomass content: 0%), and 10 parts by mass of biomass linear low-density polyethylene (manufactured by Braskem, product name: SLL-318, MFR: 2.7 g / 10 min, density: 918 kg / m 3 The raw material for the resin composition constituting the second layer was 70 parts by mass of a propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3, biomass content: 0%), and 30 parts by mass of biomass linear low-density polyethylene (manufactured by Braskem, product name: SLL-318, MFR: 2.7 g / 10 min, density: 918 kg / m 3 A resin film was produced in the same manner as in Example 2-1, except that a polypropylene film having a biomass ratio of 87% was used. The layer thickness ratio was 1:3:1 (first layer:second layer:third layer), and the thickness of the resin film was 50 μm. The polypropylene content in the resin film was 80 mass %, and the biomass ratio of the resin film was 17%. Furthermore, using the obtained resin film, a laminate and a bag were produced in the same manner as in Example 2-1.

[0173] [Example 2-4] The raw material of the resin composition constituting the first layer was 90 parts by mass of a propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 , biomass content: 0%), and 10 parts by mass of biomass linear low-density polyethylene (manufactured by Braskem, product name: SLL-318, MFR: 2.7 g / 10 min, density: 918 kg / m 3 The raw material for the resin composition constituting the second layer was 70 parts by mass of a propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 , biomass content: 0%), and 30 parts by mass of biomass linear low-density polyethylene (manufactured by Braskem, product name: SLL-318, MFR: 2.7 g / 10 min, density: 918 kg / m 3 The raw material for the resin composition constituting the third layer was 80 parts by mass of a propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 , biomass content: 0%), and 20 parts by mass of biomass linear low-density polyethylene (manufactured by Braskem, product name: SLL-318, MFR: 2.7 g / 10 min, density: 918 kg / m 3A resin film was produced in the same manner as in Example 2-1, except that a polypropylene film having a biomass ratio of 87% was used. The layer thickness ratio was 1:3:1 (first layer:second layer:third layer), and the thickness of the resin film was 50 μm. The polypropylene content in the resin film was 76% by mass, and the biomass ratio of the resin film was 21%. Furthermore, using the obtained resin film, a laminate and a bag were produced in the same manner as in Example 2-1.

[0174] [Example 2-5] The raw material for the resin composition constituting the second layer was 80 parts by mass of a propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 , biomass content: 0%), and 20 parts by mass of biomass low-density polyethylene (manufactured by Braskem, product name: SEB-853, MFR: 2.7 g / 10 min, density: 923 kg / m 3 A resin film was produced in the same manner as in Example 2-1, except that a polypropylene film having a biomass ratio of 95% was used. The layer thickness ratio was 1:3:1 (first layer:second layer:third layer), and the thickness of the resin film was 50 μm. The polypropylene content in the resin film was 88% by mass, and the biomass ratio of the resin film was 11%. Furthermore, using the obtained resin film, a laminate and a bag were produced in the same manner as in Example 2-1.

[0175] [Example 2-6] The raw material for the resin composition constituting the second layer was 70 parts by mass of a propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 , biomass content: 0%), and 30 parts by mass of biomass low-density polyethylene (manufactured by Braskem, product name: SEB-853, MFR: 2.7 g / 10 min, density: 923 kg / m 3A resin film was produced in the same manner as in Example 2-1, except that a polypropylene film having a biomass ratio of 95% was used. The layer thickness ratio was 1:3:1 (first layer:second layer:third layer), and the thickness of the resin film was 50 μm. The polypropylene content in the resin film was 82% by mass, and the biomass ratio of the resin film was 17%. Furthermore, using the obtained resin film, a laminate and a bag were produced in the same manner as in Example 2-1.

[0176] [Example 2-7] The raw material for the resin composition constituting the first layer was a propylene-ethylene block copolymer (manufactured by Prime Polymer Co., Ltd., product name: J715M, MFR: 9.0 g / 10 min, biomass content: 0%), and the raw material for the resin composition constituting the second layer was a mixture of 70 parts by mass of a propylene-ethylene block copolymer (manufactured by Prime Polymer Co., Ltd., product name: J715M, MFR: 9.0 g / 10 min, biomass content: 0%) and 30 parts by mass of a biomass linear low-density polyethylene (manufactured by Braskem, product name: SLL-318, MFR: 2.7 g / 10 min, density: 918 kg / m). 3 A resin film was produced in the same manner as in Example 2-1, except that a propylene-ethylene block copolymer (manufactured by Prime Polymer Co., Ltd., product name: J715M, MFR: 9.0 g / 10 min, biomass degree: 0%) was used as the raw material for the resin composition constituting the third layer. The layer thickness ratio was 1:3:1 (first layer:second layer:third layer), and the thickness of the resin film was 50 μm. The polypropylene content of the resin film was 82 mass %, and the biomass degree in the resin film was 16%. Furthermore, using the obtained resin film, a laminate and a bag were produced in the same manner as in Example 2-1.

[0177] [Comparative Example 2-1] Propylene-ethylene random copolymer (Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3Only the resin (biomass content: 0%) was melted, and the melt was extruded through a T-die to produce an unstretched resin film with a thickness of 50 μm. Furthermore, using the obtained resin film, a laminate and a bag were produced in the same manner as in Example 2-1.

[0178] [Comparative Example 2-2] Only the propylene-ethylene block copolymer (manufactured by Prime Polymer Co., Ltd., product name: J715M, MFR: 9.0 g / 10 min, biomass content: 0%) was melted, and the melt was extruded through a T-die to produce an unstretched resin film with a thickness of 50 μm. Furthermore, using the obtained resin film, a laminate and a bag were produced in the same manner as in Example 2-1.

[0179] [Comparative Example 2-3] The raw material for the resin composition constituting the first layer was 70 parts by mass of a propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 , biomass content: 0%), and 30 parts by mass of biomass linear low-density polyethylene (manufactured by Braskem, product name: SLL-318, MFR: 2.7 g / 10 min, density: 918 kg / m 3 The raw material for the resin composition constituting the second layer was 70 parts by mass of a propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 , biomass content: 0%), and 30 parts by mass of biomass linear low-density polyethylene (manufactured by Braskem, product name: SLL-318, MFR: 2.7 g / 10 min, density: 918 kg / m 3 A resin film was produced in the same manner as in Example 2-1, except that a polypropylene film having a biomass ratio of 87% was used. The layer thickness ratio was 1:3:1 (first layer:second layer:third layer), and the thickness of the resin film was 50 μm. The polypropylene content in the resin film was 76% by mass, and the biomass ratio of the resin film was 21%. Furthermore, using the obtained resin film, a laminate and a bag were produced in the same manner as in Example 2-1.

[0180] [Comparative Example 2-4] The raw material of the resin composition constituting the first layer was a propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 , biomass content: 0%) was melted. Next, as a raw material for the resin composition constituting the second layer, 60 parts by mass of propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 , biomass content: 0%), and 40 parts by mass of biomass linear low-density polyethylene (manufactured by Braskem, product name: SLL-318, MFR: 2.7 g / 10 min, density: 918 kg / m 3 (Biomass content: 87%) was melted separately. Next, as the raw material of the resin composition constituting the third layer, a propylene-ethylene random copolymer (manufactured by Prime Polymer Co., Ltd., product name: F219DA, MFR: 8.0 g / 10 min, density: 910 kg / m 3 (Biomass content: 0%) was melted separately. These melts were co-extruded using a T-die, but the resin composition could not be formed into a film.

[0181] Details of each layer and resin film in Examples 2-1 to 2-7 and Comparative Examples 2-1 to 2-4 are shown in Tables 3 and 4. In Table 3, "petroleum-based random PP" means a propylene-ethylene random copolymer, "petroleum-based block PP" means a propylene-ethylene block copolymer, "bio-LLDPE" means a biomass linear low-density polyethylene, and "bio-LDPE" means a biomass low-density polyethylene. All contents in Tables 3 and 4 are based on mass.

[0182] [Table 3]

[0183] [Table 4]

[0184] <<Seal strength test>> A seal strength test was conducted using bags 40 according to Examples 1-1 to 1-7 and Comparative Examples 1-1 to 1-3, and Examples 2-1 to 2-7 and Comparative Examples 2-1 to 2-3, which had a heat sealing temperature of 200°C. The seal strength was measured in accordance with JIS Z 0238:1998 at a temperature of 25°C and a relative humidity of 50%, using an SA-1150 tensile tester manufactured by Orientec Co., Ltd. Specifically, as shown in FIG. 13, a rectangular test piece 50 was cut out to include side seal portion 43a, with one side S6 measuring 15 mm and the other side S7 extending perpendicular to the first side being 50 mm. Next, as shown in Figure 14, the unsealed portion of the front film 44 and the unsealed portion of the back film 45 of the test piece 50 were arranged so that they faced in opposite directions in a direction perpendicular to the surface direction of the sealed portion, i.e., forming a T-shape. The end of the unsealed portion of the front film 44 and the end of the unsealed portion of the back film 45 were then fixed to grippers 51 and 52, respectively. The chuck distance (S8) was set to 50 mm, and the grippers 51 and 52 were pulled in opposite directions in a direction perpendicular to the surface direction of the sealed portion of the test piece 50 at a speed of 300 mm / min, and the maximum tensile stress was measured. This procedure was performed five times using test pieces 50 cut from different bags 40, and the average of the maximum tensile stress values ​​measured five times was used to determine the seal strength. The evaluation results are shown in Tables 5 and 6. (Evaluation criteria) Good: The seal strength was 40N / 15mm or more. Pass: The seal strength was 20N / 15mm or more but less than 40N / 15mm. · Unacceptable: The seal strength was less than 20N / 15mm.

[0185] <<Low temperature sealability test>> A low-temperature sealability test was conducted using bags 40 according to Examples 1-1 to 1-7 and Comparative Examples 1-1 to 1-3, and Examples 2-1 to 2-7 and Comparative Examples 2-1 to 2-3, each having a heat-sealing temperature of 150°C, 160°C, 170°C, 180°C, and 190°C. In the low-temperature sealability test, similar to the seal strength test, seal strength was measured in an environment of 25°C and 50% relative humidity in accordance with JIS Z 0238:1998, using an SA-1150 tensile tester manufactured by Orientec Co., Ltd. Specifically, as shown in FIG. 13 , a rectangular test piece 50 was cut out, having one side S6 of 15 mm and another side S7 extending perpendicular to the first side of 15 mm, so as to include side seal portion 43a. Next, as shown in Figure 14, the unsealed portion of the front film 44 and the unsealed portion of the back film 45 of the test piece 50 were arranged so that they faced in opposite directions in a direction perpendicular to the surface direction of the sealed portion, i.e., forming a T-shape. The end of the unsealed portion of the front film 44 and the end of the unsealed portion of the back film 45 were then fixed to grippers 51 and 52, respectively. The chuck distance (S8) was set to 50 mm, and the grippers 51 and 52 were pulled in opposite directions in a direction perpendicular to the surface direction of the sealed portion of the test piece 50 at a speed of 300 mm / min, and the maximum tensile stress was measured. This procedure was performed five times using test pieces 50 cut from different bags 40, and the average of the maximum tensile stress values ​​measured five times was used to determine the seal strength. The evaluation results are shown in Tables 5 and 6. (Evaluation criteria) Good: For bags with a heat seal temperature of 150°C or higher, the seal strength was 20N / 15mm or higher. Pass: For bags with a heat seal temperature of 170°C or higher, the seal strength was 20N / 15mm or higher. · Unacceptable: The seal strength was less than 20N / 15mm when the bag was heat sealed at a temperature of 190°C.

[0186] <<Tearability test>> A tear property test was conducted using bags 40 according to Examples 1-1 to 1-7 and Comparative Examples 1-1 to 1-3, as well as Examples 2-1 to 2-7 and Comparative Examples 2-1 to 2-3, all of which had a heat sealing temperature of 200°C. The tear property test was conducted by holding the sample of bag 40 of each Example and Comparative Example in the left hand so that notch 47 was on the left side and facing sideways, and tearing bag 40 by pulling it toward you with the right hand while keeping the left hand stationary. The evaluation results are shown in Tables 5 and 6. (Evaluation criteria) Good: Bag 40 could be torn in a straight line. Acceptable: Although not in a straight line, bag 40 was able to be torn. · Unacceptable: Bag 40 could not be torn.

[0187] <<Film Formability Evaluation>> The film-forming properties were evaluated based on whether or not resin films could be formed in Examples 1-1 to 1-7, Comparative Examples 1-1 to 1-4, Examples 2-1 to 2-7, and Comparative Examples 2-1 to 2-4. The evaluation results are shown in Tables 5 and 6. (Evaluation criteria) Good: The resin composition was formed into a film. · Unacceptable: The resin composition could not be made into a film.

[0188] [Table 5]

[0189] [Table 6]

[0190] As is clear from the above table, the resin film, laminate and bag of the present invention have a reduced environmental impact, as well as excellent sealing and film-forming properties and tearability. [Explanation of symbols]

[0191] 10 Resin film 11 1st layer 12 2nd layer 13 First thermoplastic resin layer 14 3rd layer 15 Second thermoplastic resin layer 20 laminate 20x inner surface 20y external surface 21 First biaxially stretched plastic film 22 Printing layer 23 First adhesive layer 24 Second biaxially stretched plastic film 25 Second adhesive layer 26 Metal foil 27 Deposited layer 28 First anchor coat layer 29 First adhesive resin layer 30 Second anchor coat layer 31 Second adhesive resin layer 40 bags 40a Storage section 41 Upper 41a Upper seal part 42 Lower 42a Lower seal 43 Side 43a Side seal 44 Surface film 45 Back film 46 Easy-to-open means 47 Notch 50 test specimens 51,52 Gripping tool

Claims

1. A resin film comprising at least a first layer, a second layer, and a third layer, the first layer and the second layer are laminated together directly or via a thermoplastic resin layer; the third layer is laminated to the second layer directly or via a thermoplastic resin layer; the first layer constitutes the innermost layer of the resin film, the resin film contains polypropylene and polyethylene, the resin composition constituting the first layer contains polypropylene as a main component, the polyethylene content of the first layer is 20% by mass or less, The resin composition constituting the second layer contains polypropylene as a main component and biomass polyethylene, the polypropylene of the second layer is a propylene-ethylene random copolymer; the polyethylene content of the second layer is 5% by mass or more and 35% by mass or less, the resin composition constituting the third layer contains polypropylene as a main component, the polyethylene content of the third layer is 35% by mass or less, The thickness of the resin film is 15 μm or more and 250 μm or less, A resin film having a biomass content of 5% or more.

2. The resin film according to claim 1, wherein the layer constituting the outermost layer of the resin film has a biomass content of 30% or less.

3. The resin film according to claim 1 or 2, wherein the polypropylene content is 66% by mass or more.

4. The resin film according to claim 1 , wherein the elongation at break in one direction and in another direction perpendicular to the one direction are each 500% or more.

5. A laminate comprising at least one biaxially stretched plastic film and the resin film according to claim 1 .

6. A bag comprising the laminate of claim 5.

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