JP2020055636A - Polyethylene-based resin composition for sealant film containing plant-derived polyethylene and sealant film - Google Patents

Abstract

To provide a polyethylene-based resin composition for sealant film for packaging material which exhibits excellent hand-cutting property and drop impact resistance while containing plant-derived polyethylene and reducing a burden on environment, and a sealant film for packaging material, a laminate, a packaging material and a package using the same.SOLUTION: There provided a polyethylene-based resin composition for a sealant film 1 of a packaging material, in which the polyethylene-based resin composition contains fossil fuel-derived polyethylene and a plant-derived polyethylene-based resin, a biomass degree is 10% or more and 50% or less, a mass ratio of C4 linear low-density polyethylene/C6 linear low-density polyethylene in the total polyethylene-based resin composition is more than 2 and 5 or less, and a density of the C6 linear low-density polyethylene is 0.910 g/cmor more and less than 0.930 g/cm.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a resin composition for a sealant film containing a plant-derived polyethylene, and a sealant film, a laminate, a packaging material, and a package produced from the resin composition. TECHNICAL FIELD The present invention relates to a polyethylene resin composition for a sealant film, which exhibits water resistance, drop impact resistance and a high degree of biomass, and a sealant film, a laminate, a packaging material, and a package for a packaging material using the same.

  In recent years, in order to reduce the burden on the environment, it has been studied to replace a part of raw materials of a polyethylene resin film such as a sealant film from fossil fuel-derived polyethylene with plant-derived polyethylene (Patent Document 1). Plant-derived polyethylene is expected to have the same physical properties as conventional fossil fuel-derived polyethylene without change in chemical structure.

However, in practice, a resin film containing a plant-derived polyethylene does not exhibit properties equivalent to those of a resin film composed of only a fossil fuel-derived polyethylene.
In particular, the resin film containing the plant-derived polyethylene has a high blending ratio of the plant-derived polyethylene, and as the biomass degree increases, the blocking resistance, hand-cutting property, and drop impact resistance when used as a sealant film are reduced. I understood.
Therefore, a polyethylene film having a high biomass degree is unsuitable as a sealant film for a packaging material that requires blocking resistance, hand-cutting property, and drop impact resistance, and lacks practicality.

JP 2009-155516 A

  The present invention solves the above-mentioned problems, and exhibits excellent blocking resistance, hand-cutting property, and drop impact resistance while containing a plant-derived polyethylene to reduce the load on the environment, and is a sealant for packaging materials. An object is to provide a polyethylene resin composition for a film, and a sealant film, a laminate, a packaging material, and a package for a packaging material using the same.

The inventor of the present invention has found that, as a result of various studies, a specific resin composition comprising a fossil fuel polyethylene resin and a plant-derived polyethylene resin in a specific ratio, the polyethylene resin composition achieves the above object. I found that.
And this invention is characterized by the following points.
1. A polyethylene resin composition for a sealant film of a packaging material,
The polyethylene-based resin composition contains a fossil fuel-derived polyethylene and a plant-derived polyethylene-based resin, and has a biomass degree of 10% or more and 50% or less,
The mass ratio of C4 linear low-density polyethylene / C6 linear low-density polyethylene in the total polyethylene resin composition is greater than 2 and 5 or less;
A polyethylene-based resin composition, wherein the density of C6 linear low-density polyethylene is 0.910 g / cm ³ or more and less than 0.930 g / cm ³ .
2. The plant-derived polyethylene resin is a plant-derived linear low-density polyethylene resin and / or a plant-derived bottom density polyethylene resin,
2. The polyethylene resin composition according to the above item 1.
3. The content of the C4 linear low-density polyethylene in the total polyethylene resin composition is 45% by mass or more and 70% by mass or less,
3. The polyethylene resin composition according to 1 or 2 above.
4. The mass ratio of the linear low-density polyethylene-based resin / the low-density polyethylene-based resin in the total polyethylene-based resin composition is 1 or more and 7 or less,
4. The polyethylene resin composition according to any one of the above 1 to 3.
5. The mass ratio of the linear low-density polyethylene-based resin / the low-density polyethylene-based resin in the total polyethylene-based resin composition is 2 or more and 5 or less,
5. The polyethylene resin composition according to any one of the above 1 to 4.
6. The total content of the C4 linear low-density polyethylene and the C6 linear low-density polyethylene in the total polyethylene resin composition is 60% by mass or more and 85% by mass or less,
6. The polyethylene resin composition according to any one of 1 to 5 above.
7. In the entire polyethylene resin composition, a plant-derived C4 linear low-density polyethylene is contained in an amount of 10% by mass or more and 60% by mass or less,
7. The polyethylene resin composition according to any one of the above 1 to 6.
8. The C4 linear low-density polyethylene and / or the C6 linear low-density polyethylene include those synthesized using a Ziegler-Natta catalyst.
8. The polyethylene resin composition according to any one of 1 to 7 above.
9. A sealant film for a packaging material, comprising a layer formed using the polyethylene-based resin composition according to any one of the above 1 to 8, and comprising a single layer or a plurality of two or more layers.
10. A sealant film for a packaging material having a multilayer structure of two or more layers produced by co-extrusion,
A layer formed from the polyethylene-based resin composition according to any one of the above 1 to 8, comprising one or two or more layers in a total range of 40% by mass or more and 100% by mass or less in all the sealant films. A sealant film for packaging materials, characterized in that:
11. A sealant film for a packaging material having a multilayer structure of three or more layers,
Both outermost layers are characterized by not containing the plant-based polyethylene resin,
The sealant film for packaging materials according to 9 or 10 above.
12. A biomass degree of 10% or more and 50% or less,
The sealant film for a packaging material according to any one of 9 to 11 above.
13. A laminate for a packaging material having a base material layer and a sealant layer,
The sealant layer may be a layer obtained by laminating the polyethylene resin composition according to any one of the above 1 to 8 by (co) extrusion coating, or the sealant film according to any one of the above 9 to 12 via an adhesive. A layered product for packaging materials, comprising a layer that has been layered by pasting.
14． 14. A packaging material produced from the laminate according to 13 above.
15. A package produced from the packaging material according to the above item 14.

The sealant film, the laminate, the packaging material, and the package produced from the polyethylene resin composition of the present invention contain a plant-derived polyethylene and have excellent blocking resistance and hand-cutting property while reducing the load on the environment. Shows drop impact resistance.
And, from the viewpoint of carbon neutrality, the increase in the amount of CO _{2 in} the atmosphere is suppressed, and
It can also contribute to saving petroleum resources.
Note that the carbon neutral, even burning plant, the amount of CO ₂ is discharged to occasion, since equal amount of CO ₂ plants absorbed during growth, it affects the increase or decrease of the amount of CO ₂ in the atmosphere Point out that there is no Therefore, the more the plant-derived raw material is contained, the more the increase in the amount of CO ₂ can be suppressed.

It is a schematic sectional drawing which shows an example about the layer structure of the sealant film (single layer) for packaging materials of this invention. It is a schematic sectional drawing which shows an example about the layer structure of the laminated body for packaging materials of this invention. It is a front view showing an example about the composition of the refill pouch formed using the packaging material of the present invention.

The present invention will be described in more detail below.
As the resin name used in the present invention, those commonly used in the industry are used.
In the present invention, the density is a value measured in accordance with JIS K 6760 (1981) for a sheet having a thickness of 1 mm obtained by press molding at 150 ° C., and the MFR is JIS K 7210 (1995). The test temperature is 190 ° C and the test load is 21.18
It is a value measured in N.

<Polyethylene resin composition>
The polyethylene resin composition of the present invention is a polyethylene resin composition for a sealant film of a packaging material, and contains fossil fuel-derived polyethylene and plant-derived polyethylene. The biomass degree of the polyethylene resin composition is preferably 10% or more and 50% or less.
Polyethylene is classified into fossil fuel-derived polyethylene resin and plant-derived polyethylene resin according to the raw materials from which it is derived, and linear low-density polyethylene (LLDPE) and low-density polyethylene (LDPE) according to its molecular structure, density, and MFR. )are categorized. Further, as the linear low-density polyethylene, there are C4 linear low-density polyethylene (C4LLDPE) and C6 linear low-density polyethylene (C6LLDPE).
That is, for example, plant-derived polyethylene resins include plant-derived C4 linear low-density polyethylene, plant-derived C6 linear low-density polyethylene, and plant-derived low-density polyethylene.
In the present invention, a copolymer of ethylene and various unsaturated compounds is also treated as a kind of polyethylene.

Further, in the present invention, “system resin” is added as a general term for various kinds, and for example, polyethylene resin is also described as a general term for various kinds of polyethylene.
In the present invention, the mass ratio of linear low-density polyethylene-based resin / low-density polyethylene-based resin in the total polyethylene-based resin composition is preferably 1 or more and 7 or less, more preferably 2 or more and 5 or less. Is more preferable.
When the mass ratio is smaller than the above range, the film is stretched when tearing the sealant film, and the hand-cutting property is easily deteriorated, and the sealing strength is easily lowered, so that the package cannot withstand impact such as dropping. There is a risk of breaking the bag. If it is larger than the above range, the tear strength of the sealant film becomes too high, so that the sealant film cannot be cut by hand, and scissors or the like are easily required.

Examples of the catalyst at the time of polymerization include a single-site catalyst such as a metallocene catalyst or a multi-site catalyst such as a Ziegler-Natta catalyst, and in the case of a single-site catalyst such as a metallocene catalyst, structural uniformity, strength, and transparency. In addition, a polyethylene having excellent sealing properties and an excellent balance between physical properties and moldability can be obtained. In the case of a multi-site catalyst such as a Ziegler-Natta catalyst, a polyethylene having excellent mechanical properties can be obtained.

  The polyethylene-based resin composition of the present invention may contain any additive as long as the effects of the present invention are not significantly impaired. Examples of the additives include various resin additives generally used for adjusting molding processability and productivity of resin films and various physical properties, such as anti-blocking agents, slip agents, antioxidants, pigments, and flow control. Materials, flame retardants, fillers, ultraviolet absorbers, surfactants and the like.

(Polyethylene resin derived from fossil fuel)
In the present invention, fossil fuel-derived polyethylene-based resin refers to ethylene obtained by thermally decomposing naphtha obtained from petroleum without using plant-derived raw materials, and α-olefins (1-butene, 1-hexene). Etc.) as a raw material.
As the polymerization method, a high-pressure method is generally used for low-density polyethylene, and a high-pressure method, a slurry method, a solution method, a gas-phase polymerization method and the like are generally used for linear low-density polyethylene.

(Plant-derived polyethylene resin)
In the present invention, the term "plant-derived" means containing carbon derived from plant raw materials, which is produced from alcohol obtained from plants.
As the plant-based polyethylene resin, a resin having an appropriate density and MFR can be selected according to the physical properties of the petroleum-derived polyethylene resin used in combination and the use of the sealant film.
As a method for producing plant-derived polyethylene, according to a conventional method, a sugar solution or starch obtained from a plant such as sugarcane, corn, sweet potato, or the like is fermented by a microorganism such as yeast to produce bioethanol, which is used as a catalyst. Then, ethylene and an α-olefin (1-butene, 1-hexene, etc.) are obtained by an intramolecular dehydration reaction or the like. Then, by using these as monomers and polymerizing in the presence of a conventional catalyst in the same manner as in the production of petroleum-derived polyethylene, a plant-derived polyethylene-based resin can be produced. As the α-olefin which is a comonomer species, a petroleum-derived one may be used in some cases.
The catalyst and the polymerization method at the time of polymerization are the same as those of the polyethylene resin derived from fossil fuel.

(Low density polyethylene)
Low density polyethylene is polyethylene that is radically polymerized under a high pressure of 100 to 400 MPa.
The low-density polyethylene used in the present invention has a density of 0.920 kg / m ³ or more,
Preferably 0.933kg / m ³ or less, 0.920kg / m ³ or more, more preferably 0.925kg / m ³ or less. MFR is 0.5 g / 10 min or more, 3.5 g
/ 10 min or less, more preferably 0.8 g / 10 min or more and 3.0 g / 10 min or less.

(Linear low density polyethylene)
Linear low-density polyethylene is a polyethylene in which ethylene and an α-olefin are polymerized under a low pressure of normal pressure to 1 MPa using a transition metal catalyst such as a Ziegler catalyst or a metallocene catalyst.
The C4 linear low-density polyethylene used in the present invention preferably has a density of 0.910 kg / m ³ or more and 0.930 kg / m ³ or less. The MFR is preferably 0.9 g / 10 min or more and 3.0 g / 10 min or less, more preferably 0.9 g / 10 min or more and 2.7 g / 10 min or less.

In the present invention, the linear low-density polyethylene may include C4 linear low-density polyethylene and / or C6 linear low-density polyethylene.
Here, the C4 linear low-density polyethylene is a linear low-density polyethylene composed of a copolymer of ethylene and 1-butene, and the C6 linear low-density polyethylene is a copolymer of ethylene and 1-hexene. It is a linear low-density polyethylene made of a copolymer.
These linear low-density polyethylenes synthesized using a Ziegler-Natta catalyst are excellent in hand-cutting properties and tearing properties when contained in a sealant layer, and are therefore preferable.

The content of the C4 linear low-density polyethylene in the total polyethylene resin composition is preferably 45% by mass or more and 70% by mass or less.
If it is smaller than the above range, the film is stretched when tearing the sealant film, the hand-cutting property tends to be deteriorated, and the seal strength tends to be low, so that the package breaks without being able to withstand the impact such as dropping. There is a fear. If it is larger than the above range, the tear strength of the sealant film becomes too high, so that the sealant film cannot be cut by hand, and scissors or the like are easily required.
In addition, the content of the plant-derived C4 linear low-density polyethylene is preferably 10% by mass or more and 60% by mass or less in the whole polyethylene resin composition.

The density of the C6 linear low-density polyethylene is preferably 0.910 g / cm ³ or more and less than 0.930 g / cm ³ . The MFR is preferably 0.9 g / 10 min or more and 3.0 g / 10 min or less, more preferably 0.9 g / 10 min or more and 2.7 g / 10 min or less.
If the density and the MFR are outside the above ranges, the drop impact resistance is likely to be reduced.

The total content of C4 linear low-density polyethylene and C6 linear low-density polyethylene in the total polyethylene resin composition is preferably 60% by mass or more and 85% by mass or less.
When the content is smaller than the above range, the film is stretched when tearing the sealant film, and the hand-cutting property is easily deteriorated, and the sealing strength is easily lowered, so that the package cannot withstand impact such as dropping. There is a risk of breaking the bag. If it is larger than the above range, the tear strength of the sealant film becomes too high, it is difficult to cut by hand, and scissors or the like are easily required.

The mass ratio of C4 linear low-density polyethylene / C6 linear low-density polyethylene in the total polyethylene resin composition is more than 2 and more preferably 5 or less.
If the mass ratio is smaller than the above range, the tear strength of the sealant film becomes too high, so that the sealant film cannot be cut by hand and scissors or the like are likely to be required. If it is larger than the above range, the film is stretched when tearing the sealant film, the hand-cutting property is easily deteriorated, and the seal strength is easily lowered, so that the package breaks without being able to withstand the impact such as dropping. There is a fear.

(High density polyethylene)
High-density polyethylene is polyethylene that is polymerized under a low pressure of normal pressure to 1 MPa using a transition metal catalyst such as a Ziegler catalyst or a metallocene catalyst.

[Slip agent]
In the present invention, known slip agents can be used without particular limitation as the slip agent.
For example, erucic acid amide, stearic acid amide, behenic acid amide, fatty acid amides such as ethylene bisoleic acid amide and ethylene bis stearic acid amide, metal soap, hydrophilic silicone, silicone-grafted acrylic, silicone-grafted epoxy resin, Examples include silicone-grafted polyether, silicone-grafted polyester, block-type silicone acrylic copolymer, polyglycerol-modified silicone, and paraffin. One of these slip agents may be used alone, or two or more thereof may be used in combination.
Furthermore, in order to increase the dispersibility of the slip agent in the polyethylene-based resin composition, the slip agent is previously melt-mixed with a thermoplastic resin such as a polyethylene-based resin at a high concentration, and used in a master batch. Is preferred.
Among them, erucamide is preferably used.

<Sealant film>
The sealant film of the present invention is a sealant film for a packaging material produced from the polyethylene resin composition of the present invention, and may be used alone or as a sealant layer of a laminate by bonding to a base material layer or the like. It can also be used.
The sealant film of the present invention may have a single-layer structure or a multi-layer structure of two or more layers, and includes at least one layer formed from the polyethylene-based resin composition of the present invention. Although it may include a layer made of an arbitrary resin, the total of the layers formed from the polyethylene resin composition of the present invention in all the sealant films may be 40% by mass or more and 100% by mass or less. preferable.
If it is smaller than the above range, the biomass degree of the sealant film is low, and the effect of reducing the environmental load is low.

Further, the sealant film of the present invention preferably has a biomass degree of 10% or more and 50% or less.
If it is smaller than the above range, the reduction of the environmental load is small, and if it is larger than the above range, the hand-cutting property and the drop impact resistance of the sealant film tend to be reduced.
The sealant film of the present invention, even though it contains a plant-derived polyethylene resin, has excellent hand-cutting properties and drop impact resistance, and is particularly suitable for refilling shampoos and rinses, refillable pouches for hermetically packaging foods and the like. It can be suitably used as a sealant film.

In the case of a multilayer structure of two or more layers, each layer may have the same composition or different compositions. In the case of a multi-layer structure of two or more layers, for example, it can be manufactured by co-extrusion lamination, or can be manufactured by laminating a manufactured film with an adhesive or the like.
In the case of a multi-layer structure, the layers other than the layer comprising the polyethylene resin composition of the present invention preferably contain any thermoplastic resin generally used as a component of a sealant film. Accordingly, for example, a resin having excellent low-temperature sealing property, a resin having excellent content resistance, a resin having excellent adhesiveness with a base film, a resin which contributes to a reduction in the thickness of the film by increasing the stiffness of the entire film, and the like. Resins that impart various functions can be selected.
When the sealant film has a multilayer structure of three or more layers, both outermost layers on both surfaces of the sealant film preferably do not contain a plant-derived polyethylene resin.

The sealant film of the present invention may contain any additive as long as the effects of the present invention are not significantly impaired. Examples of the additives include various resin additives generally used for adjusting molding processability and productivity of resin films and various physical properties, such as anti-blocking agents, slip agents, antioxidants, pigments, and flow control. Materials, flame retardants, fillers, ultraviolet absorbers, surfactants and the like.
The thickness of the sealant film of the present invention is preferably from 80 to 160 μm, more preferably from 100 to 130 μm.

(Method of manufacturing sealant film)
The method for producing a sealant film of the present invention is not particularly limited, and a conventionally known method for producing a sealant film can be applied.
In one embodiment of the present invention, a single-layered sealant film can be formed by melting the polyethylene resin composition of the present invention and subjecting the same to a melt extrusion molding method such as inflation molding or T-die molding.
In another aspect of the present invention, a sealant film having a multilayer structure is formed by melting the above-described polyethylene-based resin composition of the present invention and an arbitrary resin composition, respectively, and forming a layer comprising the polyethylene-based resin composition of the present invention. Can be formed by co-extrusion molding by a method such as inflation molding or T-die molding so as to form a multilayer structure containing at least one layer.

(Biomass degree)
The biomass degree is an index indicating a mixing ratio between a fossil fuel-derived material and a plant-derived material (biomass), and is determined by measuring the concentration of radioactive carbon ( ¹⁴ C), and is represented by the following equation. .
Biomass degree (%) = ¹⁴ C concentration (pMC) x 0.935
Although ¹⁴ C is contained at a certain concentration in plant-derived raw materials, it is scarcely present in fossil fuel confined in the ground. Therefore, by measuring the concentration of ¹⁴ C by accelerator mass spectrometry, it can be used as an index of the content ratio of the plant-derived raw material.

In the present invention, the concentration of ¹⁴ C in the sealant film is measured by burning the sealant film, which is a sample to be measured, to generate carbon dioxide, collecting and purifying it in a vacuum line, and reducing it with hydrogen using iron as a catalyst. And produce graphite. Then, the graphite and filled in tandem accelerator ¹⁴ C-AMS-only apparatus which is based on (manufactured by NEC Corp.), ¹⁴ C counts, the ¹³ C concentration ⁽¹³ C / ¹² C), the ¹⁴ C concentration ( ¹⁴ C / ¹² C) is measured, and the ratio of the 14 C concentration of the sample carbon to the standard modern carbon is calculated from the measured value. As the standard sample, an oxalic acid standard sample (HOxII) provided by the National Institute of Standards and Technology (NIST) is used.

<Laminate>
The laminate of the present invention has at least a base layer and a layer structure having a sealant layer made of a polyethylene resin composition or a sealant film of the present invention. A barrier layer may be provided between the layers, and the layers may be laminated via an adhesive.

(Base material layer)
Any resin film or sheet can be used for the base layer depending on the use of the laminate. For example, when applied to refill shampoos and rinses, refill pouches for sealing and packaging food, etc., it is excellent in mechanical strength such as tensile strength, flexural strength, impact strength, and preferably excellent in printability, for example, A biaxially stretched polyester film such as a biaxially stretched nylon film or a biaxially stretched polyethylene terephthalate film, a biaxially stretched polypropylene film, or the like can be suitably used, and a synthetic paper can also be used. These may be used alone or in combination of two or more.
The adhesive strength between the layers can be increased by previously applying an anchor coat agent to the lamination surface of the base material layer or by performing a pretreatment such as a corona treatment.

(Sealant layer)
The sealant layer of the laminate is the polyethylene resin composition of the present invention. Alternatively, it is a layer composed of the sealant film of the present invention.
As a method of laminating the sealant layer, an adhesive may be applied on the base material layer or the barrier layer, and the sealant film of the present invention may be adhered and laminated, or the adhesive layer may be formed on the base material layer or the barrier layer. The sealant film of the present invention may be adhered and laminated while being extrusion-coated, or the polyethylene-based resin composition of the present invention may be inflation-molded or T-die-molded simultaneously with another resin composition, if necessary. For example, it may be laminated on the base material layer or the barrier layer by (co) extrusion molding.
When used as a sealant for a heavy bag for storing heavy objects such as refillable pouches, a sealant film is formed by a melt extrusion molding method, and the resulting sealant film is dry-laminated on a base material layer or a barrier layer. By doing so, it is preferable to increase the strength of the laminate.

(adhesive)
As an adhesive for bonding each layer, an adhesive for dry lamination or an extrusion adhesive can be used.
In order to obtain excellent adhesive strength and tearability, it is preferable to use an adhesive for dry lamination. Specific examples of the adhesive for dry lamination include a two-component curing type polyurethane adhesive.

  When priority is given to productivity, it is preferable to use an extrusion adhesive. Specific extrusion adhesives include polyolefin-based heat-adhesive resins, ethylene-methacrylic acid copolymers, ethylene-acrylic acid copolymers, ionomers, and the like, or improved adhesion of hard resins and the like to these. A resin composition blended with an agent can be used. In addition, the biomass degree of the laminate can be further improved by including a plant-derived polyethylene in the polyolefin-based heat-adhesive resin or using the polyethylene-based resin composition of the present invention.

(Barrier layer)
As the barrier layer, in addition to metal foil such as aluminum foil, a metal film such as aluminum and aluminum oxide, a film with a vapor-deposited film obtained by vapor-depositing an inorganic oxide such as silicon oxide on a resin film such as a biaxially stretched polyethylene terephthalate film, A polyacrylonitrile film, an ethylene-vinyl alcohol copolymer film, or the like can be used.
The adhesive strength between the layers can be increased by applying an anchor coat agent on the lamination surface of the barrier layer in advance or performing a pretreatment such as a corona treatment.

<Packaging materials>
The packaging material of the present invention is a packaging material produced using the laminate of the present invention.

<Package>
The package of the present invention is a package manufactured using the packaging material of the present invention. For example, the packaging material of the present invention is used, and the package is folded in two or two packaging materials are prepared. The sealant layers are overlapped with the surfaces thereof facing each other, and the peripheral ends thereof are formed, for example, by a side seal type, a two-side seal type, a three-side seal type, a four-side seal type, an envelope-attached seal type, and a gasket-attached seal type (pillow). Various types of packaging bags can be manufactured by heat sealing using a heat sealing mode such as a sealing type), a pleated sealing type, a flat bottom sealing type, a square bottom sealing type, and a gusset type.
In the above, as a method of heat sealing, for example, a known method such as a bar seal, a rotating roll seal, a belt seal, an impulse seal, a high-frequency seal, and an ultrasonic seal can be used.

FIG. 3 is a front view showing an example of the configuration of a refill pouch, which is one mode of the package.
The refill pouch 100 shown in FIG. 3 is manufactured in a standing pouch format, and the bottom of the pouch is placed between the lower part of the front and rear wall films 11, 11 'made of the packaging material of the present invention. (The material may be the same as or different from the wall film.) A gusset portion 14 is formed by folding inward and inserting the bottom film folding portion 12 to form both sides of the bottom film folded inward. In this case, semicircular bottom film notches 13a and 13b are provided in the vicinity of the lower end, and the gusset portion 14 is heated by a ship bottom-shaped bottom seal portion 15 in which the inner side is concave in a curved line from both sides to the center. The body of the pouch is formed by heat sealing the edges on both sides of the front and rear wall films 11, 11 'with side sealing portions 16a, 16b. At the same time, one of the upper corners (the left corner in the figure) of the pouch 100 has a tapered shape whose outer periphery is heat-sealed with a spout sealing portion 17 and has a narrow width facing obliquely outward and upward. The spout 20 is provided with notches 19a and 19b on both sides thereof, and is provided in a protruding shape.

In addition, a half-cut line 21 and a notch 22 at an upper end thereof are provided as an easy-opening means at an opening position on the tip end side of the spout 20.
A portion of the upper part of the pouch 100 where the spout 20 is not provided is heat-sealed by the upper seal portion 18. However, since this portion is used as a filling port for the contents, it is not filled before the contents are filled. This is an opening of the seal and heat-sealed after filling the contents.
In addition, the half cut line 21 is shown by three parallel half cut lines in the figure, but one or two, and a plurality of half cut lines such as one to three on each side of the center half cut line. An arbitrary shape such as a shape in which the half-cut lines are parallel or converge to the center half-cut line, or a shape in which a plurality of parallel half-cut lines and oblique half-cut lines obliquely intersecting the half-cut lines are combined. It can be provided in a shape.
Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.

The raw materials used in the examples are as follows.
-Fossil fuel-derived z-C4LLDPE: UZ2010L manufactured by Prime Polymer Co., Ltd. C4LLDPE derived from fossil fuel, which is a copolymer of ethylene and 1-butene using a Ziegler-Natta catalyst. Density 0.922 g / cm ³ , MFR 2.2 g / 10 min.
-Plant-derived C4LLDPE: SLL118 manufactured by Braskem SA. Plant-derived C4LLDPE which is a copolymer of ethylene and 1-butene. Density: 0.916 g / cm ³ , MFR: 1.0 g / 10 min, biomass degree: 87%.
M-C6LLDPE derived from fossil fuel: Evolue SP2040 manufactured by Prime Polymer Co., Ltd. C6 LLDPE derived from fossil fuel, which is a copolymer of ethylene and 1-hexene using a metallocene catalyst. Density 0.918 g / cm ³ , MFR 3.8 g / 10 min.
-Fossil fuel-derived z-C6LLDPE: 2607G manufactured by Dow Chemical Japan Co., Ltd. C6 LLDPE derived from fossil fuel, which is a copolymer of ethylene and 1-hexene using a Ziegler-Natta catalyst. Density 0.919 g / cm ³ , MFR 2.3 g / 10 min.
-Fossil fuel-derived LDPE: Sumikasen G201-F manufactured by Sumitomo Chemical Co., Ltd. LDPE derived from fossil fuel using a radical initiator catalyst. Density 0.919 g / cm ³ , MFR 2.0 g / 10
Minutes.
Slip agent: M425 manufactured by Ube Maruzen Polyethylene Co., Ltd. Erucamide / LDPE mass ratio = 2/98.
Nylon film 1: Biaxially stretched nylon film. 25 μm thick.
-Nylon film 2: Biaxially stretched nylon film. 15 μm in thickness.
-Dry laminating adhesive: Two-component curing type polyurethane adhesive.

[Example 1]
The following raw materials were blended and melt-kneaded to obtain a polyethylene resin composition of the present invention. Next, a 130 μm-thick sealant film was formed from the obtained polyethylene-based resin composition using a top-blowing air-cooled inflation co-extrusion film-forming machine, and various evaluations were performed. The results are shown in Table 1.
Fossil fuel-derived z-C4LLDPE 35.8 parts by mass Plant-derived z-C4LLDPE 18.5 parts by mass Fossil fuel-derived m-C6LLDPE 18.7 parts by mass Fossil fuel-derived LDPE 26.0 parts by mass Slip agent 1.0 part by mass

Furthermore, using the sealant film prepared above, the nylon films 1 and 2 as the base material layer, and the dry laminating adhesive, a packaging material serving as a body material and a bottom material having the following layer configuration is prepared, and further used. The pouch shown in FIG. 3 was prepared and various evaluations were performed. The results are shown in Table 1.
Body material: nylon film 1 (25 μm) / printing layer / adhesive layer / sealant film (130 μm)
Bottom material: nylon film 2 (15 μm) / printing layer / adhesive layer / sealant film (150 μm)

[Examples 2 to 8, Comparative Examples 1 and 2]
At each level, the raw materials of the sealant film were changed to the contents shown in Table 1, and the same operation as in Example 1 was carried out to produce a sealant film and a pouch having the thickness shown in Table 1, and similarly, The results were evaluated and the results are shown in Table 1.

[Example 9]
The sealant film is co-extruded with the same film-forming machine so as to have a three-layer structure of z-C4LLDPE (10 μm) / polyethylene-based resin composition (110 μm) / z-C4LLDPE (10 μm) derived from fossil fuel. A sealant film and a pouch were prepared in the same manner as in Example 1 except that the film was formed, and evaluated in the same manner. The results are shown in Table 1.

[Summary of evaluation results]
In all the examples, the sealant film shows excellent breaking strength, yield strength, breaking elongation, tear strength, blocking resistance, the packaging material shows excellent sealing strength and laminating strength, and the pouch has excellent drop impact resistance. It showed hand-cutting properties.
However, in Comparative Example 1 in which the mass ratio C4LLDPE / C6LLDPE was too low, the sealant film showed a result that the tear strength in the TD direction was too strong beyond the measurement limit, and the pouch showed poor hand-cutting properties.
In Comparative Example 2 in which the biomass degree exceeds 50%, the sealant film exhibited inferior blocking resistance, drop impact resistance, and hand-cutting properties.

<Evaluation method>
[Tensile test]
A tensile test was performed on the sealant film in accordance with JIS Z 1702, and M
The breaking strength, yield strength, and breaking elongation in the D direction (flow direction) and the TD direction (width direction) were measured.

[Tear strength]
The tear strength of the sealant film in the MD direction (flow direction) and the TD direction (width direction) was measured according to JIS K 7128-2 (Elmendorf tearing method).

[Slip angle]
Using a measuring device (model number: Friction measuring device AN) manufactured by Toyo Seiki Seisaku-Sho, based on JIS P 8147: 2010 “8 Incline method”, the test piece of the static friction coefficient was measured. The inclination angle of the inclined plate when the sliding distance reached 55 mm was measured. The measurement was performed ten times, and the average value was obtained.
Dimension of lower test piece: width 90 mm x length 200 mm
Dimension of upper specimen: width 60mm x length 100mm
Weight on upper test piece: width 60 mm x length 100 mm
Change rate of inclination angle of inclined plate: 3 ° / sec

[Blocking resistance]
Using the obtained sealant film, a roll was prepared and stored in a constant temperature room at a temperature of 43 ° C. and a relative humidity of 40% for 5 days. The surface condition and the rewinding property were observed thereafter, and evaluated according to the following criteria.
A: There was no blocking between the films at all. B: There was a little blocking between the films, but there was no practical problem.
C: Peeling and rewinding could not be performed due to blocking between films.

[Seal strength]
The packaging material for the body material and the bottom material is cut into 10 cm × 10 cm, folded in half and overlapped, and the area of 1 cm × 10 cm using a heat seal tester (manufactured by Tester Sangyo Co., Ltd .: TP-701-A) is as follows. And the end was not heat-sealed and was not adhered, but a bifurcated sample was prepared.
Heat sealing temperature: 160 ° C
Heat sealing pressure: 1 kgf / cm ²
Heat sealing time: 1 second This sample was cut into a strip having a width of 15 mm, and each end divided into two branches was attached to a tensile tester, and the tensile strength (N / 15 mm) was measured under the following conditions.
Tensile test speed: 300mm / min Tensile load range: 50N

[Laminate strength]
The packaging material for the trunk material was cut into 15 mm × 100 mm, and a sample in which the sealant layer and the base material layer were peeled off at the ends and split into two parts was prepared.
Using a heat seal tester (manufactured by Tester Sangyo Co., Ltd .: TP-701-A), each of the samples was attached to a bifurcated end by a tensile tester, and the tensile strength (N / 15 mm) was obtained under the following conditions. Was measured.
Tensile test speed: 300mm / min Tensile load range: 50N

[Drop impact resistance]
Each of the 10 pouch bags was filled with 360 ml of water, dropped vertically (bottom down) 10 times and horizontally (surface down) 10 times from a height of 1.2 m, and the presence or absence of bag breakage or seal receding was confirmed. . Evaluation was made at normal temperature (25 ° C.) and low temperature (3 ° C.). The meaning of the notation of the result is as follows.
：: No bag breakage or retreat of the seal was observed.
：: Seal receding was observed very rarely.
Δ: Retraction of the seal was observed.
X: The bag was broken.

[Hand-cutting property]
The ten pouch bags were opened along the laser line from the notch portions, and it was confirmed whether the pouch bags were caught at the start of opening and whether the sealant film was stretched. Evaluation was carried out by sharing two by five people.
A: Neither snagging nor elongation of the sealant was observed.
：: There was slight catching or slight growth compared to ◎.
Δ: There was slight catching or slight elongation.
×: Caught or stretched.

REFERENCE SIGNS LIST 1 sealant film 2 layer made of polyethylene resin composition 3 layer made of arbitrary resin composition 11, 11 ′ wall film 12 bottom film folded portions 13 a, 13 b bottom film cutout portion 14 gusset portion 15 bottom seal portions 16 a, 16 b Side seal portion 17 Spout portion seal portion 18 Upper seal portions 19a, 19b Notch portion 20 Spout portion 21 Half cut line 22 Notch 100 Refillable packaging bag (pouch)

Claims (15)

A polyethylene resin composition for a sealant film of a packaging material,
The polyethylene-based resin composition contains a fossil fuel-derived polyethylene and a plant-derived polyethylene-based resin, and has a biomass degree of 10% or more and 50% or less,
The mass ratio of C4 linear low-density polyethylene / C6 linear low-density polyethylene in the total polyethylene resin composition is greater than 2 and 5 or less;
A polyethylene-based resin composition, wherein the density of C6 linear low-density polyethylene is 0.910 g / cm ³ or more and less than 0.930 g / cm ³ . The plant-derived polyethylene resin is a plant-derived linear low-density polyethylene resin and / or a plant-derived bottom density polyethylene resin,
The polyethylene resin composition according to claim 1. The content of the C4 linear low-density polyethylene in the total polyethylene resin composition is 45% by mass or more and 70% by mass or less,
The polyethylene resin composition according to claim 1. The mass ratio of the linear low-density polyethylene-based resin / the low-density polyethylene-based resin in the total polyethylene-based resin composition is 1 or more and 7 or less,
The polyethylene resin composition according to claim 1. The mass ratio of the linear low-density polyethylene-based resin / the low-density polyethylene-based resin in the total polyethylene-based resin composition is 2 or more and 5 or less,
The polyethylene resin composition according to any one of claims 1 to 4. The total content of the C4 linear low-density polyethylene and the C6 linear low-density polyethylene in the total polyethylene resin composition is 60% by mass or more and 85% by mass or less,
The polyethylene resin composition according to any one of claims 1 to 5. In the entire polyethylene resin composition, a plant-derived C4 linear low-density polyethylene is contained in an amount of 10% by mass or more and 60% by mass or less,
The polyethylene resin composition according to any one of claims 1 to 6. The C4 linear low-density polyethylene and / or the C6 linear low-density polyethylene include those synthesized using a Ziegler-Natta catalyst.
The polyethylene resin composition according to any one of claims 1 to 7.   A sealant for packaging materials, comprising a layer formed using the polyethylene resin composition according to any one of claims 1 to 8, comprising a single layer or a plurality of layers. the film. A sealant film for a packaging material having a multilayer structure of two or more layers produced by co-extrusion,
A layer formed from the polyethylene resin composition according to any one of claims 1 to 8, in a total amount of 40% by mass or more and 100% by mass or less in all the sealant films, in one or two layers. A sealant film for a packaging material, comprising: A sealant film for a packaging material having a multilayer structure of three or more layers,
Both outermost layers are characterized by not containing the plant-based polyethylene resin,
The sealant film for packaging materials according to claim 9 or 10. A biomass degree of 10% or more and 50% or less,
The sealant film for packaging materials according to any one of claims 9 to 11. A laminate for a packaging material having a base material layer and a sealant layer,
The sealant layer is a layer obtained by laminating the polyethylene resin composition according to any one of claims 1 to 8 by (co) extrusion coating, or the sealant according to any one of claims 9 to 12. A laminate for packaging materials, comprising a layer in which a film is laminated by pasting through an adhesive.   A packaging material produced from the laminate according to claim 13.   A package made from the packaging material according to claim 14.

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