JP7543750B2 - Plastic films, bags and packaging products - Google Patents

Description

The present invention relates to resin films, bags and packaging products.

In recent years, as calls for the creation of a recycling-oriented society grow, there is a desire to move away from fossil fuels in the materials field, just as in the energy field, and the use of biomass has attracted attention. Biomass is an organic compound produced by photosynthesis from carbon dioxide and water, and by using it, it becomes carbon dioxide and water again, making it a so-called carbon-neutral renewable energy. Recently, the practical application of biomass plastics made from these biomass raw materials has progressed rapidly, and attempts are also being made to produce various resins from biomass raw materials.

For example, Patent Document 1 proposes a sealant film containing polyethylene derived from plants (biomass) and a package using the same, with the aim of reducing the consumption of petroleum resources.

Patent Publication No. 2020-50789

Resin films used in bags, packaging products, and the like are required to have various functions depending on the intended use and environment of use. When using resin films in packaging products such as bags, for example, it is desirable for the resin film to be tear-resistant depending on the weight and shape of the contents.

The present invention has been made in view of the above, and an object of the present invention is to provide a resin film that can reduce carbon dioxide emissions and has excellent tear resistance.
Another object of the present invention is to provide a bag and a packaging container comprising this resin film.

The present invention provides a resin film made of a resin composition,
The resin composition is
One or more copolymers of fossil fuel-derived ethylene and fossil fuel-derived α-olefins having 6 or more carbon atoms;
A copolymer of biomass-derived ethylene and fossil fuel-derived α-olefin;
At least
The content of the copolymer of ethylene and an α-olefin having 6 or more carbon atoms contained in the resin composition is 35% by mass or more based on the entire resin composition,
The content of the copolymer of biomass-derived ethylene and fossil fuel-derived α-olefin contained in the resin composition is 50 mass% or less based on the entire resin composition,
The resin film has a thickness of 20 μm or more and 70 μm or less.

The present invention provides a resin film made of a resin composition,
The resin composition is
One or more copolymers of fossil fuel-derived ethylene and fossil fuel-derived α-olefins having 6 or more carbon atoms;
A copolymer of biomass-derived ethylene and fossil fuel-derived α-olefin;
At least
The tensile strength of the resin film in one direction is 40.0 MPa or more,
The tensile strength in a direction perpendicular to one direction of the resin film is 37.0 MPa or more,
The resin film has a tensile elongation of 600% or more in a direction perpendicular to one direction of the resin film.

The resin film may be a single layer.

The resin film may be a polyethylene resin film.

In the resin film, the resin composition may have a density of 0.925 g/cm ³ or less.

The haze value of the resin film measured in accordance with JIS K 7136:2000 may be 10% or less.

In the resin film, the resin composition contains high-pressure low-density polyethylene,
The content of the high-pressure low-density polyethylene in the resin composition may be 30 mass % or less based on the entire resin composition.

In the resin film, the high-pressure low-density polyethylene may include biomass high-pressure low-density polyethylene.

The present invention is a bag containing the above-mentioned resin film.

The present invention is a packaging product that includes the above-mentioned resin film.

According to the present invention, it is possible to provide a resin film which is capable of reducing carbon dioxide emissions and has excellent tear resistance.
According to the present invention, it is possible to provide a bag and a packaging container that include this resin film.

FIG. 1 is a cross-sectional view showing one embodiment of a resin film. FIG. 2 is a front view of one embodiment of the bag. FIG. 3 is a perspective view of the bag shown in FIG. 2 . FIG. 2 is a front view of one embodiment of the bag. FIG. 5 is a perspective view of the bag shown in FIG. 4 . FIG. 2 is a front view of one embodiment of the bag. FIG. 7 is a perspective view of the bag shown in FIG. 6 . FIG. 2 is a front view of one embodiment of the bag. FIG. 9 is a rear view of the bag shown in FIG. 8 .

One embodiment of the present invention will be described with reference to Figures 1 to 9. Note that in the drawings attached to this specification, the scale and aspect ratios have been appropriately altered and exaggerated from those of the actual product for the convenience of illustration and ease of understanding.

In addition, terms used in this specification that specify shapes, geometric conditions, and their degrees, such as "parallel," "orthogonal," and "same," as well as values of length and angle, are not to be bound by strict meanings, but are to be interpreted to include the range within which similar functions can be expected.

[Resin film]
The resin film of the present invention is composed of a resin composition described below.
In one embodiment, the resin film 10 of the present invention is a resin film having a single layer structure, as shown in FIG.
The resin film of the present invention may be a resin film having a multi-layer structure of two or more layers.

The resin film is preferably a polyethylene-based resin film. The polyethylene-based resin film contains more than 50% by mass of polyethylene as a main component. The content of polyethylene contained in the polyethylene-based resin film is preferably 70% by mass or more, more preferably 90% by mass or more, and even more preferably 99% by mass or more, based on the entire polyethylene-based resin film.
Examples of the polyethylene contained in the polyethylene-based resin film include high-density polyethylene (HDPE), medium-density polyethylene (MDPE), high-pressure low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), etc. The polyethylene-based resin film may contain one or more of these polyethylenes.
Here, high density polyethylene means polyethylene having a density of 0.942 g/cm3 or ^more , medium density polyethylene means polyethylene having a density of 0.930 g/ ^cm3 or more and less than 0.942 g/ ^cm3 , and low density polyethylene means polyethylene having a density less than 0.930 g/ ^cm3 . The density of polyethylene is a value measured according to the method specified in Method A of JIS K7112-1980 after annealing as described in JIS K6760-1995.

Here, linear low density polyethylene (LLDPE) will be described. Linear low density polyethylene refers to a copolymer of ethylene and α-olefin 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 less than 0.930 g/cm ^3. Therefore, it is a high-pressure ethylene homopolymer, and is distinguished from high-pressure low-density polyethylene (LDPE) that can be obtained by a conventionally known high-pressure radical polymerization method. The α-olefin that is the monomer of linear low-density polyethylene has 3 or more carbon atoms, and examples of the α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-nonene, 4-methylpentene, 3,3-dimethylbutene, and mixtures thereof.

The single-site catalyst is a catalyst capable of forming a uniform active species, and is usually prepared by contacting a metallocene transition metal compound or a non-metallocene transition metal compound with an activation cocatalyst. Compared to multi-site catalysts, single-site catalysts have a uniform active site structure, and are therefore preferred because they can polymerize polymers with high molecular weights and highly uniform structures. As a single-site catalyst, it is particularly preferred to use a metallocene catalyst. A metallocene catalyst is a catalyst that contains a transition metal compound of Group IV of the periodic table that contains a ligand having a cyclopentadienyl skeleton, a cocatalyst, and if necessary, an organometallic compound and each of the catalyst components of a carrier.

In the above-mentioned transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton, the cyclopentadienyl skeleton is a cyclopentadienyl group, a substituted cyclopentadienyl group, or the like. The substituted cyclopentadienyl group has at least one substituent selected from a hydrocarbon group having 1 to 30 carbon atoms, a silyl group, a silyl-substituted alkyl group, a silyl-substituted aryl group, a cyano group, a cyanoalkyl group, a cyanoaryl group, a halogen group, a haloalkyl group, a halosilyl group, or the like. The substituted cyclopentadienyl group may have two or more substituents, and the substituents may be bonded to each other to form a ring, such as an indenyl ring, a fluorenyl ring, an azulenyl ring, or a hydrogenated product thereof. The rings formed by bonding the substituents to each other may further have substituents.

In the transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton, the transition metal may be zirconium, titanium, hafnium, etc., with zirconium and hafnium being particularly preferred. The transition metal compound usually has two ligands having a cyclopentadienyl skeleton, and it is preferred that the ligands having the cyclopentadienyl skeleton are bonded to each other via a bridging group. Examples of the bridging group include alkylene groups having 1 to 4 carbon atoms, silylene groups, substituted silylene groups such as dialkylsilylene groups and diarylsilylene groups, and substituted germylene groups such as dialkylgermylene groups and diarylgermylene groups. The substituted silylene group is preferred.

In transition metal compounds of Group IV of the periodic table, representative ligands other than those having a cyclopentadienyl skeleton include hydrogen, hydrocarbon groups having 1 to 20 carbon atoms (alkyl groups, alkenyl groups, aryl groups, alkylaryl groups, aralkyl groups, polyenyl groups, etc.), halogens, metaalkyl groups, metaaryl groups, etc.

The above-mentioned transition metal compounds of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton can be used as a catalyst component, either alone or in a mixture of two or more kinds.

The co-catalyst refers to a catalyst that can effectively use the above-mentioned transition metal compound of Group IV of the periodic table as a polymerization catalyst, or can balance the ionic charge in a catalytically activated state. Examples of the co-catalyst include benzene-soluble aluminoxanes of organoaluminum oxy compounds and benzene-insoluble organoaluminum oxy compounds, ion-exchangeable layered silicates, boron compounds, ionic compounds consisting of cations with or without active hydrogen groups and non-coordinating anions, lanthanoid salts such as lanthanum oxide, tin oxide, and phenoxy compounds containing fluoro groups.

The transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton may be used supported on an inorganic or organic carrier, preferably an inorganic or organic porous oxide, specifically _{montmorillonite or other ion-exchangeable layered silicate, SiO2, Al2O3 , MgO , ZrO2} , _TiO2 , _B2O3 , CaO, ZnO, BaO, _ThO2 , or mixtures thereof.

Furthermore, examples of organometallic compounds that may be used as necessary include organoaluminum compounds, organomagnesium compounds, and organozinc compounds. Of these, organoaluminum compounds are preferably used.

In one embodiment, the resin film of the present invention has a tensile strength in one direction of the resin film of 40.0 MPa or more. The tensile strength is preferably 41.0 MPa or more, more preferably 42.0 MPa or more, and even more preferably 45.0 MPa or more.
The tensile elongation in one direction of the resin film is preferably 200% or more and 700% or less, more preferably 300% or more and 600% or less, and even more preferably 350% or more and 500% or less.
One direction of the resin film may be the machine direction (MD).

In one embodiment, the resin film of the present invention has a tensile strength in a direction perpendicular to one direction of the resin film of 37.0 MPa or more. The tensile strength is preferably 38.0 MPa or more, more preferably 40.0 MPa or more, and even more preferably 42.0 MPa or more.
In one embodiment, the resin film of the present invention has a tensile elongation of 600% or more in a direction perpendicular to one direction of the resin film. The tensile elongation is preferably 650% or more and 1000% or less, more preferably 700% or more and 900% or less, and even more preferably 7% or more and 850% or less.
The direction perpendicular to one direction of the resin film may be a direction perpendicular to the machine direction (MD).

The tensile strength and tensile elongation can be measured in accordance with JIS Z 1702:1994. A constant crosshead speed type tester can be used. A dumbbell-shaped film having a width of 10 mm and a length of 120 mm cut from a resin film can be used as a test piece. The distance between a pair of chucks holding the test piece at the start of measurement is 80 mm, and the tensile speed is 500 mm/min. The length of the test piece can be adjusted as long as the test piece can be held by the pair of chucks. In this application, unless otherwise specified, the temperature during measurement of the tensile strength and tensile elongation is 23°C and the relative humidity is 50%.
As the tensile tester, a force gauge ZTA-500N manufactured by Imada Co., Ltd. can be used.

The haze value of the resin film may be 15% or less. The haze value of the resin film is preferably 10% or less, more preferably 9% or less, and even more preferably 7% or less. The haze value of the resin film can be measured in accordance with JIS K 7136:2000. As a haze value measuring device (haze meter), NDH7000SP manufactured by Nippon Denshoku Industries Co., Ltd. can be used.

In one embodiment, the resin film of the present invention has a thickness of 20 μm or more and 70 μm or less.
By making the thickness of the resin film 20 μm or more, the tear resistance of the resin film can be improved.
By setting the thickness of the resin film to 70 μm or less, the amount of the resin composition used can be reduced, and the amount of carbon dioxide emissions can be reduced, that is, the environmental load can be reduced.
The thickness of the resin film is preferably 20 μm or more and 60 μm or less, and more preferably 25 μm or more and 55 μm or less.

<Resin Composition>
In the resin film of the present invention, the resin composition is
One or more copolymers of fossil fuel-derived ethylene and fossil fuel-derived α-olefins having 6 or more carbon atoms;
A copolymer of biomass-derived ethylene and fossil fuel-derived α-olefin;
It includes at least the following.
This can reduce the environmental load of the resin film and improve its tear resistance.

Fossil fuel-derived ethylene and fossil fuel-derived alpha-olefins are obtained by pyrolysis of naphtha and other petroleum-derived raw materials, without using plant-derived raw materials.

Alpha olefins have three or more carbon atoms, and examples thereof include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-nonene, 4-methylpentene, 3,3-dimethylbutene, and the like, and mixtures thereof.
The α-olefin used as a copolymerizable monomer with biomass-derived ethylene is preferably butene, more preferably 1-butene.
Examples of α-olefins having 6 or more carbon atoms and used as copolymerization monomers with fossil fuel-derived ethylene include 1-hexene, 1-octene, 1-nonene, 4-methylpentene, 3,3-dimethylbutene, and mixtures thereof. The α-olefins having 6 or more carbon atoms are preferably 1-hexene, 1-octene, or mixtures thereof.
The α-olefin preferably has 6 or more and 10 or less carbon atoms, and more preferably has 6 or more and 8 or less carbon atoms.

In the resin composition, the copolymer of fossil fuel-derived ethylene and fossil fuel-derived α-olefin having 6 or more carbon atoms may be a combination of two or more types. The copolymer of fossil fuel-derived ethylene and fossil fuel-derived α-olefin having 6 or more carbon atoms is preferably a combination of a copolymer of fossil fuel-derived ethylene and fossil fuel-derived α-olefin having 6 carbon atoms, and a copolymer of fossil fuel-derived ethylene and fossil fuel-derived α-olefin having 8 carbon atoms, and more preferably a copolymer of fossil fuel-derived ethylene and fossil fuel-derived 1-hexene, and a copolymer of fossil fuel-derived ethylene and fossil fuel-derived 1-octene,

The method for producing biomass-derived ethylene is not particularly limited, and it can be obtained by a conventionally known method. An example of a method for producing biomass-derived ethylene is described below.

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 any conventionally known plant can be used. Examples include corn, sugarcane, beet, and manioc.

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 the crushed microorganism, and then purifying the ethanol. Conventional methods such as distillation, membrane separation, and extraction can be used to purify ethanol from the culture solution. For example, methods include adding benzene, cyclohexane, etc., and performing azeotropic distillation, or removing water by membrane separation, etc.

To obtain the above ethylene, further advanced purification may be carried out at this stage, such as reducing the total amount of impurities in the ethanol to 1 ppm or less.

A catalyst is usually used when obtaining ethylene by the dehydration reaction of ethanol, but there is no particular limitation on the catalyst, and any conventionally known catalyst can be used. From a process standpoint, a fixed-bed flow reaction is advantageous because it is easy to separate the catalyst from the product; for example, gamma-alumina is preferred.

Since this dehydration reaction is an endothermic reaction, it is usually carried out under heating conditions. There are no limitations on the heating temperature as long as the reaction proceeds at a commercially useful reaction rate, but a temperature of 100°C or higher is preferable, more preferably 250°C or higher, and even more preferably 300°C or higher is appropriate. 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.

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. In general, when performing a dehydration reaction, it is preferable to have no water, considering the efficiency of removing water. However, in the case of the dehydration reaction of ethanol using a solid catalyst, it has been found that the amount of other olefins, especially butene, produced tends to increase if water is not present. This is probably because the presence of a small amount of water makes it difficult to suppress ethylene dimerization after dehydration. The lower limit of the allowable water content is 0.1 mass% or more, preferably 0.5 mass% or more. There is no particular limit to the upper limit, but from the viewpoint of material balance and heat balance, it is preferably 50 mass% or less, more preferably 30 mass% or less, and even more preferably 20 mass% or less.

By carrying out the dehydration reaction of ethanol in this way, a mixture of ethylene, water, and a small amount of unreacted ethanol is obtained. However, 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 any known method.

The ethylene obtained by gas-liquid separation is further distilled. There are no particular restrictions on the distillation method, operating temperature, residence time, etc., except that the operating pressure is normal pressure or higher.

When the raw material is biomass-derived ethanol, the ethylene obtained contains trace amounts of carbonyl compounds such as ketones, aldehydes, and esters, which are impurities mixed in during the ethanol fermentation process, as well as carbon dioxide, which is their decomposition product, and nitrogen-containing compounds such as amines and amino acids, which are enzyme decomposition products and impurities, as well as ammonia, which is their decomposition product. Depending on the 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 can be performed by a conventionally known method. An example of a suitable purification operation is an adsorption purification method. The adsorbent used is not particularly limited, and conventionally known adsorbents can be used. For example, a high-area material is preferable, 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.

Caustic water treatment may also be used in combination as a method for purifying impurities in ethylene. If caustic water treatment is used, it is preferable to carry it out before adsorption purification. In that case, it is necessary to carry out a moisture removal treatment after the caustic treatment and before adsorption purification.

The copolymer contained in the resin composition can be obtained by a known polymerization method using biomass-derived ethylene or fossil fuel-derived ethylene and fossil fuel-derived α-olefins with the above-mentioned single-site catalyst, etc.

In one embodiment, the content of the copolymer of biomass-derived ethylene and fossil fuel-derived α-olefin contained in the resin composition is 50 mass% or less with respect to the entire resin composition.
The content of the copolymer of biomass-derived ethylene and fossil fuel-derived α-olefin contained in the resin composition is preferably 1% by mass or more and 50% by mass or less, more preferably 5% by mass or more and 40% by mass or less, and more preferably 10% by mass or more and 30% by mass or more, based on the entire resin composition. This can further improve the environmental load reduction of the resin film.
Furthermore, by making the content of the above copolymer 1 mass % or less, the slipperiness of the resin film can be improved, and when the resin film is used in a packaged product, the opening property of the packaged product can be improved.

The biomass degree of the resin composition may be 50% or less. The biomass degree of the resin composition is preferably 1% or more and 50% or less, more preferably 5% or more and 40% or less, and even more preferably 10% or more and 30% or less. This can further improve the environmental load reduction of the resin film.

Here, the biomass degree will be described.
Carbon dioxide in the atmosphere contains a certain percentage of C14 (105.5 pMC), so it is known that the C14 content in plants that grow by absorbing carbon dioxide from the atmosphere, such as corn, is also about 105.5 pMC. It is also known that fossil fuels contain very little C14. Therefore, by measuring the percentage of C14 in the total carbon atoms, the percentage of carbon derived from biomass can be calculated.
The term "biomass degree" refers to the weight ratio of biomass-derived components. For example, in the case of polyethylene terephthalate, polyethylene terephthalate is a polymer of ethylene glycol containing 2 carbon atoms and terephthalic acid containing 8 carbon atoms in a molar ratio of 1:1. Therefore, when only biomass-derived ethylene glycol is used, the weight ratio of biomass-derived components in the polyester is 31.25%, so the theoretical value of the biomass degree is 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. In addition, the weight ratio of biomass-derived components in the fossil fuel polyester produced using fossil fuel-derived ethylene glycol and fossil fuel-derived dicarboxylic acid is 0%, and the biomass degree of the fossil fuel polyester is 0%. Hereinafter, unless otherwise specified, "biomass degree" refers to the weight ratio of biomass-derived components.

Theoretically, if only biomass-derived raw materials are used as raw materials 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 raw materials derived from fossil fuels is 0%.

In one embodiment, the content of the copolymer of ethylene and an α-olefin having 6 or more carbon atoms contained in the resin composition is 35% by mass or more based on the entire resin composition. This can improve the environmental load reduction and tear resistance of the resin film.
The content of the copolymer of ethylene and an α-olefin having 6 or more carbon atoms contained in the resin composition is preferably 35 mass% or more and 90 mass% or less, and more preferably 45 mass% or more and 80 mass% or less, based on the entire resin composition.

The resin composition preferably contains a copolymer of ethylene and an α-olefin having 8 or more carbon atoms, which can improve the tear resistance of the resin film.
The content of the copolymer of ethylene and an α-olefin having 8 or more carbon atoms contained in the resin composition is preferably 20 mass% or more, more preferably 30 mass% or more, and even more preferably 40 mass% or more, based on the entire resin composition.

The resin composition may contain high-pressure low-density polyethylene, which can reduce the haze value of the resin film and improve the processability of the resin composition.
The content of high-pressure polyethylene in the resin composition is preferably 30% by mass or less, more preferably 1% by mass or more and 30% by mass or less, and even more preferably 10% by mass or more and 25% by mass or less.

It is preferable that the high-pressure low-density polyethylene contains biomass high-pressure low-density polyethylene. This can further improve the environmental load reduction of the resin film and further reduce the haze of the resin film.

The resin composition may include high density polyethylene (HDPE), medium density polyethylene (MDPE), or a mixture thereof.

The resin composition may contain one or more antiblocking agents. Examples of the antiblocking agent include synthetic silica, natural silica, talc, and synthetic zeolite. Synthetic silica and synthetic zeolite refer to those produced by artificial means. Among these, the antiblocking agent is preferably synthetic zeolite.
By including an antiblocking agent in the resin composition, the slipperiness of the resin film can be improved, and when the resin film is used in a packaged product, the opening property of the packaged product can be improved.
The antiblocking agent can be added to the resin composition in the form of a masterbatch containing the antiblocking agent and polyethylene.

The content of the antiblocking agent in the resin composition is preferably 0.01% by mass or more and 1% by mass or less, and more preferably 0.1% by mass or more and 0.5% by mass or less, based on the entire resin composition.
By setting the content of the antiblocking agent to 0.01% by mass or more, the slipperiness of the resin film can be further improved.
By setting the content of the antiblocking agent to 0.5% by mass or less, the tear resistance of the resin film can be further improved.

The resin film of the present invention may contain one or more additives. Examples of additives include plasticizers, UV stabilizers, color inhibitors, matting agents, deodorants, flame retardants, weather resistance agents, antistatic agents, thread friction reducers, slip agents, antioxidants, ion exchange agents, and color pigments.

The density of the resin composition is preferably 0.925 g/cm ³ or less, more preferably 0.900 g/cm ³ or more and 0.925 g/cm ³ or less, and even more preferably 0.910 g/cm ³ or more and 0.925 g/cm ³ or less.

The density of a copolymer of fossil fuel-derived ethylene and a fossil fuel-derived α-olefin having 6 or more carbon atoms is preferably 0.930 g/ ^cm3 or less, more preferably 0.910 g/ ^cm3 or more and 0.930 g/ ^cm3 or less, and even more preferably 0.915 g/ ^cm3 or more and 0.925 g/ ^cm3 or less.

The density of the copolymer of biomass-derived ethylene and fossil fuel-derived α-olefin is preferably 0.925 g/ ^cm3 or less, more preferably 0.900 g/ ^cm3 or more and 0.925 g/ ^cm3 or less, and even more preferably 0.910 g/ ^cm3 or more and 0.920 g/ ^cm3 or less.

The melt flow rate (MFR) of a copolymer of fossil fuel-derived ethylene and fossil fuel-derived α-olefin having 6 or more carbon atoms is preferably 0.1 g/10 min to 10 g/10 min, more preferably 0.2 g/10 min to 5 g/10 min, and even more preferably 0.5 g/10 min to 3 g/10 min. The melt flow rate is a value measured by Method A under the conditions of a temperature of 190° C. and a load of 21.18 N in the method specified in JIS K7210-1995.
By setting the MFR to 0.1 g/10 min or more, the extrusion load during molding can be reduced, whereas by setting the MFR to 10 g/10 min or less, the mechanical strength of the resin film can be increased.

The melt flow rate (MFR) of the copolymer of biomass-derived ethylene and fossil fuel-derived α-olefin is preferably 0.1 g/10 min to 10 g/10 min, more preferably 0.2 g/10 min to 5 g/10 min, and even more preferably 0.5 g/10 min to 3 g/10 min. By setting the MFR to 0.1 g/10 min or more, the extrusion load during molding can be reduced. By setting the MFR to 10 g/10 min or less, the mechanical strength of the resin film can be increased.

The resin film of the present invention may have a printed layer. The printed layer expresses letters, numbers, symbols, figures, pictures, etc.

The resin film of the present invention has excellent tear resistance and is therefore suitable for use in packaging products, particularly bags, etc.

[Method of manufacturing resin film]
The method for producing the resin film of the present invention is not particularly limited, and can be produced by a conventionally known method. The resin film is more preferably produced 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.

In the T-die method, first, the materials constituting the resin composition are dried, and then supplied to a melt extruder heated to a temperature equal to or higher than the melting point (Tm) to a temperature of Tm+100° C. to melt them and extrude them into a sheet from a T-die. The extruded sheet is then quenched 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.

In the inflation method, first, the materials constituting the resin composition are dried, and then fed into a melt extruder heated to a temperature above the melting point (Tm) to Tm+100°C, where they are melted and extruded into a cylindrical shape through a ring die. At this time, air is fed into the cylindrical molten resin from below to expand the diameter of the cylinder to a predetermined size, and cooling air is fed from below to the outside of the cylinder. This expanded cylindrical body is called a bubble. Next, the bubble is folded into a film shape by a guide plate and a pinch roll, and wound up in a winding section. The folded film may be wound up as it is in a cylindrical shape, or both ends of the cylinder may be removed by a slitter or the like, cut into two films, and then each may be wound up. This 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.

When the resin film has a multi-layer structure, it is preferable that the resin film is formed by co-extrusion molding. It is more preferable that the co-extrusion molding is performed by the T-die method or the inflation method.

The melting temperature of the materials constituting the resin composition is preferably 150°C or higher and 190°C or lower, and more preferably 170°C or higher and 175°C or lower.

[Packaged products]
The packaging product of the present invention contains the resin film of the present invention. Examples of the packaging product include bags, laminates, tubes, lids, sheet molded products, label materials, etc. Since the resin film used in the packaging product of the present invention has excellent tear resistance, the packaging product is preferably a bag.

Fig. 2 is a front view showing one embodiment of a bag 20 including the resin film 10 of the present invention. Fig. 3 is a perspective view of the bag 20 shown in Fig. 2. The bag 20 has an upper portion 21, a lower portion 22, and a pair of side portions 23, and has a substantially rectangular shape. In the bag 20, the surface film 24 and the back film 25 are composed of one resin film 10. In the bag 20, the bottom portion 22 is joined by a bottom joining portion 26. The upper portion 21 is provided with an opening 27 for storing or removing the contents. The upper side of the bag 20 is provided with a hole 28 penetrating the surface film 24 and the back film 25. The hole 28 can be used as a handle when carrying the contents.
In the bag 20, the front film 24 and the back film 25 may be formed from two independent resin films 10. In this case, the pair of side portions 23 may be joined by a side joint portion, and the bottom portion 22 may be joined by a bottom joint portion 26 (not shown).
In the bag 20, the pair of side portions 23 may have a folded-back portion that is a valley fold on the inside (not shown).
In addition, the hatched portions in FIG. 2 and FIG. 3 indicate joints.

In one embodiment, the joint can be formed by heat sealing, for example, a known method such as bar sealing, rotary roll sealing, belt sealing, impulse sealing, high frequency sealing, ultrasonic sealing, and melt-cut sealing.
In one embodiment, the joint can be formed by hot melt, for example, a known method using adhesives such as ethylene-vinyl acetate copolymer, polyolefins such as polyethylene and polypropylene, and rubber.

When the bag 20 shown in Figures 2 and 3 is used to transport the contents, a load is applied around the hole 28, which may cause the bag 20 to tear. By including the resin film 10 of the present invention, the bag 20 can have improved tear resistance.

Contents of the bag 20 may include, for example, catalogs, pamphlets, magazines, leaflets, booklets, stickers, and flat resin molded products.

The bag 20 can hold, for example, 10 g to 2.5 kg of contents.

FIG. 4 is a front view showing one embodiment of a bag 30 including the resin film 10 of the present invention. FIG. 5 is a perspective view of the bag 30 shown in FIG. 4. The bag 30 has an upper portion 31, a lower portion 32, and a pair of side portions 33, and has a substantially rectangular shape. In the bag 30, the surface film 34 and the back film 35 are formed from a single resin film 10. In the bag 30, the pair of side portions 33 are joined by side joint portions 36. The upper portion 31 is provided with an opening 37 for storing or removing contents. The upper side of the bag 30 is provided with a hole 38 penetrating the surface film 34 and the back film 35. The hole 38 can be used as a handle when transporting the contents. The bag 30 has a head fold portion 39 in which the surface film 34 and the back film 35 are each folded inward. The bag 30 has a bottom portion 32 having a fold portion 40 in which the bottom portion 32 is folded inward.
4 and 5 indicate joints. The joints can be formed by heat sealing and/or hot melt. Examples of heat sealing and hot melt include those mentioned above.

When the bag 30 shown in Figs. 4 and 5 is used to transport the contents, a load is applied around the hole 38, which may cause the bag 30 to tear. The bag 30 contains the resin film 10 of the present invention, which can improve the tear resistance of the bag. In addition, the bag 30 has a top fold 39, which can further improve the tear resistance of the bag.

The contents of the bag 30 may include, for example, bottles filled with liquids and/or solids, unfilled bottles, can containers filled with liquids and/or solids, unfilled can containers, and refill pouches.

The bag 30 can hold, for example, 0.3 kg to 4.0 kg of contents.

FIG. 6 is a front view showing one embodiment of a bag 50 including the resin film 10 of the present invention. FIG. 7 is a perspective view of the bag 50 shown in FIG. 6. The bag 50 has an upper portion 51, a lower portion 52, and a pair of side portions 53, and has a substantially rectangular shape. In the bag 50, the surface film 54 and the back film 55 are formed from a single resin film 10. In the bag 50, the pair of side portions 53 are joined by side joint portions 56. The upper portion 51 is provided with an opening 57 for storing or removing contents. The bag 50 has a head fold portion 58 in which the surface film 54 and the back film 55 are folded back inward. The head fold portion 58 of the surface film 54 is joined at a head fold joint portion 59, and similarly, the head fold portion 58 of the back film 55 is joined at a head fold joint portion 59. The bag 50 has a folded back portion 60 in which the bottom portion 52 is folded inward in a valley shape. The bag 50 has two handles 61. The handles 61 are joined to the upper part of the front film 54 and the upper part of the back film 55 by handle joining parts 62 .
6 and 7 indicate joints. The joints can be formed by heat sealing and/or hot melt. Examples of heat sealing and hot melt include those mentioned above.

When the bag 50 shown in Figs. 6 and 7 is used to transport the contents, a load is applied around the handle joint 62, which may cause the bag 50 to tear. The bag 50 contains the resin film 10 of the present invention, which can improve the tear resistance of the bag. In addition, the bag 50 has a top fold 58, which can further improve the tear resistance of the bag.

The contents of the bag 50 may include, for example, a bottle filled with liquids and/or solids, an unfilled bottle, a can container filled with liquids and/or solids, an unfilled can container, and a refill pouch.

The bag 50 can hold, for example, 0.3 kg to 4.0 kg of contents.

Fig. 8 is a front view showing one embodiment of a bag 70 including the resin film 10 of the present invention. Fig. 9 is a rear view of the bag 70 shown in Fig. 8. The bag 70 has an upper portion 71, a lower portion 72, and a pair of side portions 73, and has a substantially rectangular shape. In the bag 70, the front surface film 74 and the back surface film 75 are composed of a single resin film 10. In the bag 50, the pair of side portions 53 are each joined by a side joint portion 56. In Fig. 8, the bag 70 has an overlapping portion 77 of the resin film 10. In the bag 50, the overlapping portion 77 is joined by an overlapping portion joint portion 78.
8 and 9 indicate joints. The joints can be formed by heat sealing and/or hot melt. Examples of heat sealing and hot melt include those mentioned above.

Contents of the bag 70 include, for example, catalogs, pamphlets, magazines, leaflets, booklets, stickers, and flat resin molded products.

The bag 70 can hold, for example, 10 g to 2.5 kg of contents.

The packaging product of the present invention may have a printed layer on the front and/or inside of the packaging product. The printed layer expresses letters, numbers, symbols, figures, pictures, etc.

Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the description of the following examples as long as it does not depart from the gist of the present invention.
The materials used in the examples are as follows:
Bio-C4 copolymer: a copolymer of biomass-derived ethylene and fossil fuel-derived α-olefin with 4 carbon atoms (manufactured by Braskem, product name: SLL-118, density: 0.916 g/cm ³ , MFR: 1.0 g/10 min, biomass content: 87%)
Petroleum C6 copolymer: a copolymer of ethylene derived from a fossil fuel and an α-olefin having 6 carbon atoms derived from a fossil fuel (manufactured by The Dow Chemical Company, product name: DOWLEX (registered trademark) 2645, density: 0.918 g/cm ³ , MFR: 0.85 g/10 min, biomass content: 0%)
Petrochemical C8 copolymer: a copolymer of ethylene derived from a fossil fuel and an α-olefin having 8 carbon atoms derived from a fossil fuel (manufactured by The Dow Chemical Company, product name: DOWLEX (registered trademark) 2045, density: 0.922 g/cm ³ , MFR: 1.0 g/10 min, biomass content: 0%)
Petrochemical C4 copolymer: a copolymer of ethylene derived from a fossil fuel and an α-olefin having 4 carbon atoms derived from a fossil fuel (manufactured by PTT Polymer Marketing Company Limited, product name: LL7410D, density: 0.921 g/cm ³ , MFR: 1.0 g/10 min, biomass content: 0%)
Petroleum-based LDPE: fossil fuel high-pressure low-density polyethylene (manufactured by PTT Polymer Marketing Company Limited, product name: LD2426H, density: 0.924 g/cm ³ , MFR: 1.9 g/10 min, biomass content: 0%)
Bio-LDPE: Biomass high-pressure low-density polyethylene (manufactured by Braskem, product name: STN7006, density: 0.924 g/cm ³ , MFR: 0.6 g/10 min, biomass ratio 95%)
Petrochemical MB: Polyethylene master batch (manufactured by Prime Polymer Co., Ltd., product name: EAZ-30, density: 0.62 g/cm ³ , biomass content: 0%, composition containing 30% by mass of synthetic zeolite and 80% by mass of low-density polyethylene)

[Example 1]
30 parts by mass of bio-C4 copolymer, 59 parts by mass of petroleum-based C6 copolymer, 10 parts by mass of petroleum-based LDPE, and 1 part by mass of polyethylene master batch were mixed and melted to obtain a resin composition.

The resulting melt of the resin composition was extruded using a T-die to obtain a resin form with a thickness of 50 μm. The density, biomass ratio, and content of each resin of the resin film of this example are shown in Table 1. In Table 1, all "%"s are based on mass.

The bag shown in Figure 2 was made using the resin film of this example.

[Example 2]
A resin film having a thickness of 50 μm was obtained in the same manner as in Example 1, except that a resin composition was obtained using 5 parts by mass of the bio-C4 copolymer, 84 parts by mass of the petroleum-based C6 copolymer, 10 parts by mass of the petroleum-based LDPE, and 1 part by mass of the petroleum-based MB. The density, biomass ratio, and content of each resin of the resin film of this example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this example.

[Example 3]
A resin film having a thickness of 50 μm was obtained in the same manner as in Example 1, except that a resin composition was obtained using 40 parts by mass of the bio-C4 copolymer, 49 parts by mass of the petroleum-based C6 copolymer, 10 parts by mass of the petroleum-based LDPE, and 1 part by mass of the petroleum-based MB. The density, biomass ratio, and content of each resin of the resin film of this example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this example.

[Example 4]
A resin film having a thickness of 50 μm was obtained in the same manner as in Example 1, except that a resin composition was obtained using 50 parts by mass of the bio-C4 copolymer, 39 parts by mass of the petroleum-based C6 copolymer, 10 parts by mass of the petroleum-based LDPE, and 1 part by mass of the petroleum-based MB. The density, biomass ratio, and content of each resin of the resin film of this example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this example.

[Example 5]
A resin film having a thickness of 50 μm was obtained in the same manner as in Example 1, except that a resin composition was obtained using 30 parts by mass of bio-C4 copolymer, 29 parts by mass of petroleum-based C6 copolymer, 30 parts by mass of petroleum-based C8 copolymer, 10 parts by mass of petroleum-based LDPE, and 1 part by mass of petroleum-based MB. The density, biomass degree, and content of each resin of the resin film of this example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this example.

[Example 6]
A resin film having a thickness of 50 μm was obtained in the same manner as in Example 1, except that a resin composition was obtained using 40 parts by mass of bio-C4 copolymer, 19 parts by mass of petroleum-based C6 copolymer, 30 parts by mass of petroleum-based C8 copolymer, 10 parts by mass of petroleum-based LDPE, and 1 part by mass of petroleum-based MB. The density, biomass degree, and content of each resin of the resin film of this example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this example.

[Example 7]
A resin film having a thickness of 50 μm was obtained in the same manner as in Example 1, except that a resin composition was obtained using 40 parts by mass of the bio-C4 copolymer, 49 parts by mass of the petroleum-based C8 copolymer, 10 parts by mass of the petroleum-based LDPE, and 1 part by mass of the petroleum-based MB. The density, biomass ratio, and content of each resin of the resin film of this example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this example.

[Example 8]
A resin film having a thickness of 50 μm was obtained in the same manner as in Example 1, except that a resin composition was obtained using 20 parts by mass of the bio-C4 copolymer, 69 parts by mass of the petroleum-based C6 copolymer, 10 parts by mass of the bio-LDPE, and 1 part by mass of the petroleum-based MB. The density, biomass ratio, and content of each resin of the resin film of this example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this example.

[Example 9]
A resin film having a thickness of 50 μm was obtained in the same manner as in Example 1, except that a resin composition was obtained using 30 parts by mass of the bio-C4 copolymer, 45 parts by mass of the petroleum-based C6 copolymer, and 25 parts by mass of the petroleum-based LDPE. The density, biomass ratio, and content of each resin of the resin film of this example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this example.

[Comparative Example 1]
A resin film having a thickness of 50 μm was obtained in the same manner as in Example 1, except that a resin composition was obtained using 90 parts by mass of petroleum-based C4 copolymer and 10 parts by mass of petroleum-based LDPE. The density, biomass degree, and content of each resin of the resin film of this comparative example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this comparative example.

[Comparative Example 2]
A resin film having a thickness of 50 μm was obtained in the same manner as in Example 1, except that a resin composition was obtained using 5 parts by mass of the bio-C4 copolymer, 85 parts by mass of the petroleum-based C4 copolymer, and 10 parts by mass of the petroleum-based LDPE. The density, biomass ratio, and content of each resin of the resin film of this comparative example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this comparative example.

[Comparative Example 3]
A resin film having a thickness of 50 μm was obtained in the same manner as in Example 1, except that a resin composition was obtained using 30 parts by mass of the bio-C4 copolymer, 60 parts by mass of the petroleum-based C4 copolymer, and 10 parts by mass of the petroleum-based LDPE. The density, biomass ratio, and content of each resin of the resin film of this comparative example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this comparative example.

[Comparative Example 4]
A resin film having a thickness of 50 μm was obtained in the same manner as in Example 1, except that a resin composition was obtained using 40 parts by mass of the bio-C4 copolymer, 50 parts by mass of the petroleum-based C4 copolymer, and 10 parts by mass of the petroleum-based LDPE. The density, biomass ratio, and content of each resin of the resin film of this comparative example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this comparative example.

[Comparative Example 5]
A resin film having a thickness of 50 μm was obtained in the same manner as in Example 1, except that a resin composition was obtained using 50 parts by mass of the bio-C4 copolymer, 40 parts by mass of the petroleum-based C4 copolymer, and 10 parts by mass of the petroleum-based LDPE. The density, biomass ratio, and content of each resin of the resin film of this comparative example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this comparative example.

[Comparative Example 6]
A resin film having a thickness of 50 μm was obtained in the same manner as in Example 1, except that a resin composition was obtained using 40 parts by mass of petroleum-based C4 copolymer, 49 parts by mass of petroleum-based C6 copolymer, 10 parts by mass of petroleum-based LDPE, and 1 part by mass of petroleum-based MB. The density, biomass degree, and content of each resin of the resin film of this comparative example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this comparative example.

[Comparative Example 7]
A resin film having a thickness of 50 μm was obtained in the same manner as in Example 1, except that a resin composition was obtained using 25 parts by mass of petroleum-based C6 copolymer, 64 parts by mass of bio-based C4 copolymer, 10 parts by mass of petroleum-based LDPE, and 1 part by mass of petroleum-based MB. The density, biomass ratio, and content of each resin of the resin film of this comparative example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this comparative example.

[Example 10]
A resin film having a thickness of 40 μm was obtained using the same resin composition as in Example 1 in the same manner as in Example 1. The density, biomass ratio, and content of each resin of the resin film of this example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this example.

[Example 11]
A resin film having a thickness of 40 μm was obtained using the same resin composition as in Example 4 in the same manner as in Example 10. The density, biomass degree, and content of each resin of the resin film of this example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this example.

[Example 12]
A resin film having a thickness of 40 μm was obtained in the same manner as in Example 10, using the same resin composition as in Example 5. The density, biomass degree, and content of each resin of the resin film of this example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this example.

[Example 13]
A resin film having a thickness of 40 μm was obtained using the same resin composition as in Example 7 in the same manner as in Example 10. The density, biomass degree, and content of each resin of the resin film of this example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this example.

[Example 14]
A resin film having a thickness of 40 μm was obtained using the same resin composition as in Example 8 in the same manner as in Example 10. The density, biomass degree, and content of each resin of the resin film of this example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this example.

[Example 15]
A resin film having a thickness of 30 μm was obtained using the same resin composition as in Example 1 in the same manner as in Example 1. The density, biomass degree, and content of each resin of the resin film of this example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this example.

[Example 16]
A resin film having a thickness of 30 μm was obtained in the same manner as in Example 15, using the same resin composition as in Example 5. The density, biomass degree, and content of each resin of the resin film of this example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this example.

[Example 17]
A resin film having a thickness of 30 μm was obtained using the same resin composition as in Example 8 in the same manner as in Example 15. The density, biomass degree, and content of each resin of the resin film of this example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this example.

[Example 18]
A resin film having a thickness of 27 μm was obtained using the same resin composition as in Example 1 in the same manner as in Example 1. The density, biomass ratio, and content of each resin of the resin film of this example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this example.

[Example 19]
A resin film having a thickness of 27 μm was obtained in the same manner as in Example 18, using the same resin composition as in Example 5. The density, biomass ratio, and content of each resin of the resin film of this example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this example.

[Example 20]
A resin film having a thickness of 27 μm was obtained in the same manner as in Example 18, using the same resin composition as in Example 7. The density, biomass degree, and content of each resin of the resin film of this example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this example.

[Example 21]
A resin film having a thickness of 27 μm was obtained in the same manner as in Example 18, using the same resin composition as in Example 8. The density, biomass ratio, and content of each resin of the resin film of this example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this example.

[Example 22]
A resin film having a thickness of 25 μm was obtained using the same resin composition as in Example 1 in the same manner as in Example 1. The density, biomass ratio, and content of each resin of the resin film of this example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this example.

[Example 23]
A resin film having a thickness of 25 μm was obtained in the same manner as in Example 22, using the same resin composition as in Example 5. The density, biomass degree, and content of each resin of the resin film of this example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this example.

[Example 24]
A resin film having a thickness of 25 μm was obtained in the same manner as in Example 22, using the same resin composition as in Example 7. The density, biomass ratio, and content of each resin of the resin film of this example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this example.

[Example 25]
A resin film having a thickness of 25 μm was obtained in the same manner as in Example 22, except that a resin composition was obtained using 30 parts by mass of the bio-C4 copolymer, 60 parts by mass of the petroleum-based C6 copolymer, and 10 parts by mass of the petroleum-based LDPE. The density, biomass ratio, and content of each resin of the resin film of this example are shown in Table 1.

The bag shown in Figure 2 was made using the resin film of this example.

<Measurement of tensile strength and tensile elongation>
The tensile strength and tensile elongation in the machine direction (MD) and perpendicular direction (TD) of the resin films prepared in the above examples and comparative examples were measured. The tensile strength of the resin film was measured in accordance with JIS Z1702. A force gauge ZT series (constant crosshead speed type) manufactured by Imada Co., Ltd. was used as the tensile tester. A rectangular film cut from the resin film with a width of 10 mm and a length of 120 mm can be used as the test piece. The distance between the pair of chucks holding the test piece at the start of the measurement is 80 mm, and the tensile speed is 500 mm/min. The temperature during the measurement was 23°C, and the relative humidity was 50%. The measurement results are shown in Table 2.

<Evaluation of Haze Value>
The haze values of the resin films produced in Examples 2, 4, 5, and 7 to 9 were measured. The haze values of the resin films were measured in accordance with JIS K 7136:2000. The measuring device (haze meter) used was NDH7000SP manufactured by Nippon Denshoku Industries Co., Ltd. The measurement results are shown in Table 3.

<Evaluation of Slipperiness>
The slipperiness of the surfaces of the resin films produced in Examples 1 and 4 and Comparative Example 6 was measured. In the evaluation of slipperiness, the friction coefficient of the surface of the resin film was measured. Specifically, the static friction coefficient and the dynamic friction coefficient between the surface of the resin film and the surface of the metal plate were measured. The measurement was performed in accordance with JIS K 7125:1999 using an autograph AG-5kNXpusHS manufactured by Shimadzu Corporation. A polished SUS plate (#360) was used as the metal plate. The contact area between the metal plate and the resin film was 40 cm ² (length of one side: 63 mm), and the normal force was 1.96 N.

The specific method of measurement is described below. First, a test specimen with a cut resin film was prepared. The test specimen was then stored for 48 hours or more in an environment with a temperature of 23±2°C and a humidity of 50±5%. The test specimen was then slid on the surface of a metal plate at a speed of 100 mm/min in an environment with a temperature of 23±2°C and a humidity of 50±5%. The static and dynamic friction coefficients of the surface of the test specimen were calculated based on the force applied to the test specimen when the sliding started and the force applied to the test specimen during the movement. This was performed five times, and the average of the five times was calculated. The calculation results of the average are shown in Table 4.

The resin film of the present invention uses a material derived from biomass, and therefore has excellent environmental load reducing properties and can reduce carbon dioxide emissions.
As shown in Table 2, the resin film of the present invention has high tensile strength and tensile elongation, and is therefore excellent in tear resistance.
In addition, as shown in Table 3, it is understood that the haze value is reduced by increasing the content of low-density polyethylene. It is also understood that the haze value is further reduced by using biomass low-density polyethylene.
Furthermore, as shown in Table 4, it can be seen that the greater the content of the bio-C4 copolymer in the resin composition, the more improved the slipperiness of the resin film.

10: Resin film 20: Bag 21: Top 22: Bottom 23: Side 24: Surface film 25: Back film 26: Bottom joint 27: Opening 28: Hole 30: Bag 31: Top 32: Bottom 33: Side 34: Surface film 35: Back film 36: Side joint 37: Opening 38: Hole 39: Folded-back portion 40: Top folded portion 50: Bag 51: Top 52: Bottom 53: Side 54: Surface film 55: Back film 56: Side joint 57: Opening 58: Top folded portion 59: Top folded joint 60: Folded-back portion 61: Handle 62: Handle joint 70: Bag 71: Top 72: Bottom 73: Side 74: Surface film 75: Back film 76: Side joint 77: Overlapped portion 78: Overlapped joint

Claims (9)

A resin film made of a resin composition,
The resin composition comprises
One or more copolymers of fossil fuel-derived ethylene and fossil fuel-derived α-olefins having 6 or more carbon atoms;
A copolymer of biomass-derived ethylene and fossil fuel-derived α-olefin;
High-pressure low-density polyethylene;
At least
The content of the copolymer of ethylene and an α-olefin having 6 or more carbon atoms contained in the resin composition is 35% by mass or more based on the entire resin composition,
The content of the copolymer of biomass-derived ethylene and fossil fuel-derived α-olefin contained in the resin composition is 50 mass% or less with respect to the entire resin composition,
The content of the high-pressure low-density polyethylene contained in the resin composition is 1% by mass or more and 30% by mass or less based on the entire resin composition,
The resin film has a thickness of 20 μm or more and 70 μm or less. A resin film made of a resin composition,
The resin composition comprises
One or more copolymers of fossil fuel-derived ethylene and fossil fuel-derived α-olefins having 6 or more carbon atoms;
A copolymer of biomass-derived ethylene and fossil fuel-derived α-olefin;
High-pressure low-density polyethylene;
At least
The content of the high-pressure low-density polyethylene contained in the resin composition is 1% by mass or more and 30% by mass or less based on the entire resin composition,
The tensile strength in one direction of the resin film is 40.0 MPa or more,
The resin film has a tensile strength of 37.0 MPa or more in a direction perpendicular to the one direction,
A resin film having a tensile elongation of 600% or more in a direction perpendicular to the one direction of the resin film. The resin film according to claim 1 or 2, which has a single layer structure. The resin film according to any one of claims 1 to 3, which is a polyethylene-based resin film. The resin film according to any one of claims 1 to 4, wherein the density of the resin composition is 0.925 g / cm ³ or less. The resin film according to any one of claims 1 to 5, wherein the haze value of the resin film measured in accordance with JIS K 7136:2000 is 10% or less. The resin film according to any one of claims 1 to 6 , wherein the high-pressure low-density polyethylene includes biomass high-pressure low-density polyethylene. A bag comprising the resin film according to any one of claims 1 to 7 . A packaging product comprising the resin film according to any one of claims 1 to 7 .