JP7259243B2 - Polyethylene-based resin composition for sealant film containing plant-derived polyethylene and sealant film - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resin composition for a sealant film containing plant-derived polyethylene, and a sealant film, laminate, packaging material, and package prepared from the resin composition, and more particularly, excellent blocking resistance and hand-cutting. The present invention relates to a polyethylene-based resin composition for sealant films that exhibits strength, drop impact resistance, and a high degree of biomass, and sealant films, laminates, packaging materials, and packages for packaging materials using the same.

In recent years, in order to reduce the burden on the environment, replacing some of the raw materials of polyethylene resin films such as sealant films from fossil fuel-derived polyethylene with plant-derived polyethylene has been studied (Patent Document 1). Plant-derived polyethylene is expected to have the same chemical structure and physical properties as conventional fossil fuel-derived polyethylene.
However, in practice, a resin film containing plant-derived polyethylene does not exhibit the same properties as a resin film made of only fossil fuel-derived polyethylene.
In particular, resin films containing plant-derived polyethylene have a high blending ratio of plant-derived polyethylene, and as the degree of biomass increases, the blocking resistance, hand-tearability, and drop impact resistance when used as a sealant film decrease. I found out.
Therefore, polyethylene films with a high degree of biomass are unsuitable as sealant films for packaging materials that require blocking resistance, hand tearability, and drop impact resistance, and lack practical utility.

JP 2009-155516 A

The present invention solves the above problems and is a sealant for packaging materials that contains plant-derived polyethylene to reduce the burden on the environment while exhibiting excellent blocking resistance, hand tearability, and drop impact resistance. An object of the present invention is to provide a polyethylene-based resin composition for film, and a sealant film for packaging, a laminate, a packaging material, and a package using the same.

As a result of various studies, the present inventors have found that a specific polyethylene-based resin composition characterized by containing a specific fossil fuel polyethylene-based resin and a plant-derived polyethylene-based resin in a specific ratio achieves the above object. I found out.
The present 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 entire polyethylene-based resin composition is greater than 2 and 5 or less,
C6 linear low-density polyethylene having a density of 0.930 g/cm ³ or more and less than 0.950 g/cm ³ ,
A polyethylene resin composition.
2. The plant-derived polyethylene-based resin is a plant-derived linear low-density polyethylene-based resin and/or a plant-derived low-density polyethylene-based resin,
1. The polyethylene-based resin composition as described in 1 above.
3. The content of the C4 linear low-density polyethylene in the entire polyethylene-based resin composition is greater than 45% by mass and 70% by mass or less,
3. The polyethylene-based 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 entire polyethylene-based resin composition is 1 or more and 7 or less,
4. The polyethylene-based resin composition according to any one of 1 to 3 above.
5. The mass ratio of the linear low-density polyethylene-based resin/the low-density polyethylene-based resin in the entire polyethylene-based resin composition is 2 or more and 5 or less,
5. The polyethylene-based resin composition according to any one of 1 to 4 above.
6. The total content of the C4 linear low-density polyethylene and the C6 linear low-density polyethylene in the entire 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. Characterized by containing 10% by mass or more and 50% by mass or less of plant-derived C4 linear low-density polyethylene in the entire polyethylene-based resin composition,
7. The polyethylene-based resin composition according to any one of 1 to 6 above.
8. The C4 linear low density polyethylene and / or the C6 linear low density polyethylene includes 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 packaging materials, comprising a layer formed using the polyethylene resin composition according to any one of 1 to 8 above, and comprising a single layer or a plurality of layers of two or more layers.
10. A sealant film for a packaging material having a multi-layer structure of two or more layers produced by coextrusion,
The layer formed from the polyethylene-based resin composition according to any one of the above 1 to 8 is included in the total amount of the sealant film in a range of 40% by mass or more and 100% by mass or less, and 1 layer or 2 layers or more. characterized by
Sealant film for packaging materials.
11. A sealant film for packaging materials having a multi-layer structure of 3 or more layers,
Both outermost layers do not contain the plant-derived polyethylene resin,
12. Sealant film for packaging material according to 9 or 10 above. characterized by a biomass degree of 10% or more and 50% or less,
12. The sealant film for packaging materials as described in any one of 9 to 11 above.
13. A laminate for packaging material, comprising a substrate layer and a sealant layer,
The sealant layer is a layer obtained by laminating the polyethylene resin composition according to any one of 1 to 8 above by (co)extrusion coating, or a sealant film according to any one of above 9 to 12 via an adhesive. characterized by comprising layers laminated by pasting together,
Laminates for packaging materials.
14. 14. A packaging material characterized by being produced from the laminate described in 13 above.
15. 15. A package, characterized in that it is produced from the packaging material described in 14 above.

Sealant films, laminates, packaging materials, and packages produced from the polyethylene-based resin composition of the present invention contain plant-derived polyethylene to reduce the burden on the environment, while having excellent anti-blocking properties and hand-cutting properties. , indicates drop impact resistance.
From the viewpoint of carbon neutrality, it is possible to suppress an increase in the amount of CO ₂ in the atmosphere and contribute to the saving of petroleum resources.
Carbon-neutral means that even if plants are burned, the amount of _CO2 emitted during that process is equal to the amount of _CO2 absorbed by the plant during its growth, so it does not affect changes in the amount of _CO2 in the atmosphere. means not Therefore, the more the plant-derived raw material is contained, the more the amount of CO ₂ can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic sectional drawing which shows the example about the layer structure of the sealant film (single layer) for packaging materials of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic sectional drawing which shows the example about the layer structure of the laminated body for packaging materials of this invention. 1 is a front view showing one example of the configuration of a refill pouch formed using the packaging material of the present invention. FIG.

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

<Polyethylene resin composition>
The polyethylene-based resin composition of the present invention is a polyethylene-based resin composition for sealant films of packaging materials, and contains fossil fuel-derived polyethylene and plant-derived polyethylene. The biomass degree of the polyethylene-based resin composition is preferably 10% or more and 50% or less.
Polyethylene is classified into fossil fuel-derived polyethylene-based resins and plant-derived polyethylene-based resins according to the raw materials from which it is derived. )are categorized. Furthermore, linear low density polyethylene includes C4 linear low density polyethylene (C4LLDPE) and C6 linear low density polyethylene (C6LLDPE).
That is, for example, plant-derived polyethylene-based 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, copolymers of ethylene and various unsaturated compounds are also treated as one type of polyethylene.
Furthermore, in the present invention, the term "system resin" is added as a general term for various types of polyethylene, and for example, various types of polyethylene are also collectively referred to as polyethylene-based resins.
In the present invention, the mass ratio of linear low-density polyethylene-based resin/low-density polyethylene-based resin in the entire polyethylene-based resin composition is preferably 1 or more and 7 or less, and is 2 or more and 5 or less. is more preferable.
If the mass ratio is smaller than the above range, the film will stretch when the sealant film is torn, and hand-tearability tends to deteriorate, and the sealing strength tends to decrease, so that the package cannot withstand impacts such as dropping. There is a risk of bag breakage. If it is larger than the above range, the tear strength of the sealant film becomes too high, and it is difficult to cut it by hand, and scissors or the like are likely to be necessary.

Further, the catalyst for polymerization includes single-site catalysts such as metallocene catalysts and multi-site catalysts such as Ziegler-Natta catalysts. In the case of single-site catalysts such as metallocene catalysts, structural uniformity, strength and transparency In the case of a multi-site catalyst such as a Ziegler-Natta catalyst, 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. Additives include various resin additives commonly used to adjust molding processability, productivity, and various physical properties of resin films, such as antiblocking agents, slip agents, antioxidants, pigments, and flow control agents. materials, flame retardants, fillers, UV absorbers, surfactants, and the like.

(fossil fuel-derived polyethylene resin)
In the present invention, the fossil fuel-derived polyethylene resin refers to ethylene and α-olefins (1-butene, 1-hexene, etc.) as a raw material.

(Plant-derived polyethylene resin)
In the present invention, “plant-derived” means containing carbon derived from plant raw materials, which is produced from alcohol obtained from plants.
A plant-derived polyethylene resin having a suitable density and MFR can be selected according to the physical properties of the petroleum-derived polyethylene resin used in combination and the application of the sealant film.
As a method for producing plant-derived polyethylene, according to a conventional method, sugar solution and starch obtained from plants such as sugar cane, corn, and sweet potato are fermented with microorganisms such as yeast to produce bioethanol. Ethylene and α-olefins (1-butene, 1-hexene, etc.) are obtained through intramolecular dehydration reaction and the like. Then, using these as monomers, a plant-derived polyethylene resin can be produced by polymerizing in the presence of a conventional catalyst in the same manner as in the production of petroleum-derived polyethylene. The α-olefin, which is a comonomer species, can optionally be derived from petroleum.
The catalyst and polymerization method for polymerization are the same as those for the fossil fuel-derived polyethylene resin.

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

(linear low-density polyethylene)
Linear low-density polyethylene is polyethylene in which ethylene and 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 minutes or more and 3.0 g/10 minutes or less, more preferably 0.9 g/10 minutes or more and 2.7 g/10 minutes or less.

In the present invention, 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 made 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 consisting of a copolymer.

These linear low-density polyethylenes synthesized using a Ziegler-Natta catalyst are preferable because they are excellent in hand-cutting and tearability when contained in the sealant layer.
The content of C4 linear low-density polyethylene in the entire polyethylene-based 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 will stretch when the sealant film is torn, making it easier to cut by hand, and the sealing strength will tend to be lower, so the package will not withstand impacts such as dropping and will break. There is fear. If it is larger than the above range, the tear strength of the sealant film becomes too high, and it is difficult to cut it by hand, and scissors or the like are likely to be necessary.

Moreover, the content of the plant-derived C4 linear low-density polyethylene is preferably 10% by mass or more and 50% by mass or less in the entire polyethylene-based resin composition.
The density of the C6 linear low-density polyethylene is preferably 0.930 g/cm ³ or more and less than 0.950 g/cm ³ , more preferably 0.935 g/cm ³ or more and less than 0.945 g/cm ³ . 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 MFR are out of the above ranges, the drop impact resistance tends to decrease.

The total content of C4 linear low-density polyethylene and C6 linear low-density polyethylene in the entire polyethylene-based resin composition is preferably 60% by mass or more and 85% by mass or less.
If the content is less than the above range, the film will stretch when the sealant film is torn, making it difficult to cut by hand, and the sealing strength will tend to be low, so that the package will not be able to withstand impacts such as dropping. There is a risk of bag breakage. If it is larger than the above range, the tear strength of the sealant film will be too high, making it difficult to cut by hand and tending to require scissors or the like.

The mass ratio of C4 linear low-density polyethylene/C6 linear low-density polyethylene in the entire polyethylene-based resin composition is more preferably greater than 2 and 5 or less.
If the mass ratio is less than the above range, the tear strength of the sealant film becomes too high, and the film cannot be cut by hand, often requiring scissors or the like. If it is larger than the above range, the film will stretch when the sealant film is torn, making it easier to tear by hand, and the sealing strength will tend to be lower, so the package will break without being able to withstand impacts such as dropping. There is fear.

(high density polyethylene)
High-density polyethylene is polyethylene 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 any particular limitation.
For example, erucic acid amide, stearic acid amide, behenic acid amide, fatty acid amide such as ethylenebisoleic acid amide and ethylenebisstearic acid amide, metal soap, hydrophilic silicone, silicone-grafted acrylic, silicone-grafted epoxy resin, Silicone-grafted polyethers, silicone-grafted polyesters, block-type silicone-acrylic copolymers, polyglycerol-modified silicones, paraffins, and the like. These slip agents may be used singly or in combination of two or more.
Furthermore, in order to increase the dispersibility of the slip agent in the polyethylene resin composition, the slip agent is preliminarily melt-mixed with a thermoplastic resin such as a polyethylene resin at a high concentration and used as a masterbatch. is preferred.
Among the above, it is preferable to use erucamide.

<Sealant film>
The sealant film of the present invention is a sealant film for packaging materials produced from the polyethylene resin composition of the present invention. can also be used.
The sealant film of the present invention may have a single layer structure or a multilayer structure of two or more layers, and may include at least one layer formed from the polyethylene resin composition of the present invention. A layer made of any resin may be included, but the total amount of layers formed from the polyethylene-based resin composition of the present invention in the entire sealant film is 40% by mass or more and 100% by mass or less. preferable.
If it is smaller than the above range, the degree of biomass of the sealant film will be low, and the effect of reducing the environmental load will be low.

Moreover, 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 drop impact resistance of the sealant film tend to deteriorate.
The sealant film of the present invention has excellent hand tearability and drop impact resistance while containing a plant-derived polyethylene resin. 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 produced by co-extrusion lamination, or it can be produced by pasting already-produced films together with an adhesive or the like.
In the case of a multilayer structure, the layers other than the layer made of the polyethylene-based resin composition of the present invention preferably contain any thermoplastic resin generally used as a constituent component of a sealant film. Accordingly, for example, resins with excellent low-temperature sealability, resins with excellent content resistance, resins with excellent adhesiveness to the base film, resins that increase the stiffness of the entire film and contribute to thinning of the film, etc. A resin that imparts various functions can be selected.

Moreover, when the sealant film has a multi-layer structure of three or more layers, both outermost layers, which are 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 it does not significantly impair the effects of the present invention. Additives include various resin additives commonly used to adjust molding processability, productivity, and various physical properties of resin films, such as antiblocking agents, slip agents, antioxidants, pigments, and flow control agents. materials, flame retardants, fillers, UV absorbers, surfactants, and the like.
The thickness of the sealant film of the present invention is preferably 80-160 μm, more preferably 100-130 μm.

(Manufacturing method of sealant film)
The method for producing the 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 aspect of the present invention, the single-layered sealant film can be produced by melting the polyethylene resin composition of the present invention and by a melt extrusion molding method such as inflation molding or T-die molding.
In another aspect of the present invention, a multilayered sealant film is obtained by melting the polyethylene resin composition of the present invention and an arbitrary resin composition, respectively, and forming a layer composed of the polyethylene resin composition of the present invention. A film can be formed by co-extrusion molding by a method such as inflation molding or T-die molding so as to have a multilayer structure containing at least one layer.

(Biomass degree)
The degree of biomass is an index representing the mixing ratio of raw materials derived from fossil fuels and raw materials derived from plants (biomass), is determined by measuring the concentration of radioactive carbon ( ¹⁴ C), and is expressed by the following formula. .
Biomass degree (%) = ¹⁴ C concentration (pMC) x 0.935
This ¹⁴ C is contained at a certain concentration in raw materials derived from plants, but is almost absent in fossil fuels trapped in the ground. Therefore, by measuring the concentration of ¹⁴ C by accelerator mass spectrometry, it can be used as an indicator of the content of plant-derived raw materials.

In the present invention, the concentration of ¹⁴ C in the sealant film is measured by burning the sealant film, which is the 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, this graphite is filled in a tandem accelerator-based ¹⁴ C-AMS dedicated device (manufactured by NEC) to count ¹⁴ C, the concentration of ¹³ C ( ¹³ C/ ¹² C), the concentration of ¹⁴ C ( ¹⁴ C/ ¹² C) is measured and from this measurement the ratio of ¹⁴ C concentration of sample carbon to standard modern carbon is calculated. As a standard sample, an oxalic acid standard sample (HOxII) provided by the US National Institute of Standards (NIST) is used.

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

(Base material layer)
Any resin film or sheet can be used as the base film depending on the use of the laminate. For example, when applied to refillable pouches for hermetically packaging refillable shampoos, conditioners, foods, etc., it is preferable that the resin be excellent in mechanical strength such as tensile strength, flexural strength, and impact strength, as well as being excellent in printability. A biaxially oriented nylon film, a biaxially oriented polyester film such as a biaxially oriented polyethylene terephthalate film, a biaxially oriented polypropylene film, and the like can be suitably used, and synthetic paper and the like can also be used. These may be used singly or in combination.
The bonding strength between the layers can be increased by previously applying an anchor coating agent to the lamination surface of the base material layer or by performing pretreatment such as corona treatment.

(sealant layer)
The sealant layer of the laminate is the polyethylene resin composition of the invention. Alternatively, it is a layer made of the sealant film of the present invention.
As a method for laminating the sealant layer, an adhesive may be applied onto the substrate layer or the barrier layer, and the sealant film of the present invention may be adhered and laminated. Alternatively, an adhesive layer may be formed on the substrate layer or the barrier layer. The sealant film of the present invention may be adhered and laminated while extrusion coating, or the polyethylene resin composition of the present invention may be subjected to inflation molding or T-die molding simultaneously with other resin compositions as necessary. You may laminate|stack by (co)extrusion molding on a base material layer or a barrier layer by methods, such as.
When used as a sealant for heavy bags for containing heavy items such as refill pouches, a sealant film is formed by a melt extrusion molding method, and the obtained sealant film is dry-laminated on the base material layer or barrier layer. By doing so, it is preferable to increase the strength of the laminate.

(glue)
A dry lamination adhesive or an extrusion adhesive can be used as an adhesive for bonding between layers.
In order to obtain excellent adhesive strength and tearability, it is preferable to use an adhesive for dry lamination. Specific examples of dry lamination adhesives include two-part curable polyurethane-based adhesives.
When productivity is given priority, it is preferable to use an extrusion adhesive. Specific extrusion adhesives include polyolefin thermal adhesive resins, ethylene-methacrylic acid copolymers, ethylene-acrylic acid copolymers, ionomers, etc., or these with improved adhesiveness such as hard resins. A resin composition in which the agent is blended can be used. In addition, the biomass content of the laminate can be further improved by including plant-derived polyethylene in the polyolefin-based thermal adhesive resin or by 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 film with a vapor-deposited film obtained by vapor-depositing a metal such as aluminum or an inorganic oxide such as aluminum oxide or silicon oxide on a resin film such as a biaxially stretched polyethylene terephthalate film, A polyacrylonitrile film, an ethylene-vinyl alcohol copolymer film, and the like can be used.
The bonding strength between the layers can be increased by previously applying an anchor coating agent to the lamination surface of the barrier layer or by performing pretreatment such as corona treatment.

<Packaging material>
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 made using the packaging material of the present invention. For example, the packaging material of the present invention is used and folded in two, or two packaging materials are prepared , the surfaces of the sealant layers are overlapped so that they face each other, and the peripheral edges are subjected to, for example, a side seal type, a two-side seal type, a three-side seal type, a four-side seal type, an envelope-sticking seal type, a palm-sticking seal type (pillow Various forms of packaging bags can be produced by heat sealing in a heat sealing form such as a seal type), a pleated seal type, a flat bottom seal type, a square bottom seal type, and a gusset type.
In the above, the heat sealing can be carried out by known methods such as bar sealing, rotary roll sealing, belt sealing, impulse sealing, high frequency sealing and ultrasonic sealing.

FIG. 3 is a front view showing an example of the configuration of a refillable pouch, which is one aspect of the package.
The refill pouch 100 shown in FIG. 3 is produced in the form of a standing pouch. The material may be the same as or different from the wall film) is folded inward and formed in a form having a gusset portion 14 formed by inserting it to the bottom film folded portion 12, and both sides of the bottom film folded inward Near the lower end, in this case, semicircular bottom film cutouts 13a and 13b are provided, and the gusset portion 14 is heated by a ship bottom-shaped bottom sealing portion 15 whose inner side is curved linearly concave 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 and 11' with the side seal portions 16a and 16b, and one of the upper portions of the pouch 100 is formed. At the corner portion (left corner portion in the figure), a taper portion 20 with a narrow width facing obliquely outward and upward is formed by heat-sealing the outer circumference with the spout portion seal portion 17, and notches are formed on both sides thereof. It is provided in a protruding shape by providing portions 19a and 19b.
At the unsealing position on the tip side of the spout 20, a half-cut line 21 and a notch 22 are provided at the upper end of the half-cut line 21 as easy-to-open means.

Of the upper portion of the pouch 100, the portion where the spout portion 20 is not provided is heat-sealed with the upper seal portion 18, but since this portion is used as a filling port for the content, it is not filled before the content is filled. It is used as an opening for sealing, and is heat-sealed after filling with contents.
The half-cut lines 21 are shown as three parallel half-cut lines in the figure, but in addition to one or two, there may be more than one such as one to three lines on each side of the central half-cut line. Arbitrary half-cut lines, such as a shape converging to a central half-cut line, or a shape combining a plurality of parallel half-cut lines and diagonal half-cut lines that cross diagonally. shape can be provided.
EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples.

Raw materials used in the examples are as follows.
• Fossil fuel-derived z-C4LLDPE: UZ2010L manufactured by Prime Polymer Co., Ltd. Fossil-derived C4LLDPE, which is a copolymer of ethylene and 1-butene with a Ziegler-Natta catalyst. Density 0.922 g/cm ³ , MFR 2.2 g/10 minutes.
• Plant-derived z-C4LLDPE: SLL118 manufactured by Braskem SA. Plant-derived C4LLDPE, a copolymer of ethylene and 1-butene catalyzed by Ziegler-Natta. Density 0.916 g/cm ³ , MFR 1.0 g/10 minutes, biomass degree 87%.
- Fossil fuel-derived m-C6LLDPE1: Evolue SP4030F manufactured by Prime Polymer Co., Ltd. Fossil fuel-derived C6LLDPE, which is a metallocene-catalyzed copolymer of ethylene and 1-hexene. Density 0.938 g/cm ³ , MFR 3.8 g/10 minutes.
• Fossil fuel-derived m-C6LLDPE2: Evolue SP2040 manufactured by Prime Polymer Co., Ltd. Fossil fuel-derived C6LLDPE, which is a metallocene-catalyzed copolymer of ethylene and 1-hexene. Density 0.918 g/cm ³ , MFR 3.8 g/10 minutes.

• Fossil fuel-derived z-C6LLDPE: 2607G manufactured by Dow Chemical Japan. Fossil fuel derived C6LLDPE which is a copolymer of ethylene and 1-hexene with a Ziegler-Natta catalyst. Density 0.919 g/cm ³ , MFR 2.3 g/10 minutes.
・Fossil fuel-derived LDPE: Sumikasen G201-F manufactured by Sumitomo Chemical Co., Ltd. Fossil-derived LDPE with 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 oriented nylon film. 25 μm thick.
- Nylon film 2: Biaxially oriented nylon film. 15 μm thick.
・Dry laminate adhesive: Two-component curing type polyurethane adhesive.

[Example 1]
The following raw materials were blended and melt-kneaded to obtain the polyethylene resin composition 1 of the present invention. Subsequently, the resulting polyethylene resin composition was used to form a sealant film having a thickness of 130 μm using a top-blown air-cooled inflation co-extrusion film forming machine, and various evaluations were performed.
Fossil fuel-derived z-C4LLDPE 35.8 parts by mass Plant-derived z-C4LLDPE 18.5 parts by mass Fossil fuel-derived m-C6LLDPE1 18.7 parts by mass Fossil fuel-derived LDPE 26.0 parts by mass Slip agent 1.0 parts by mass

Furthermore, using the sealant film prepared above, nylon films 1 and 2 as base layers, and a dry laminate adhesive, a packaging material having the following layer structure and serving as a base material was prepared, and further used. The pouches shown in FIG.
Body material: nylon film 1 (25 μm)/printed layer/adhesive layer/sealant film (120 μm)
Bottom material: Nylon film 2 (15 μm)/printing layer/adhesive layer/sealant film (150 μm)

[Example 2]
The sealant film is co-extruded with the same film forming machine so that it has a three-layer structure of fossil fuel-derived z-C4LLDPE (10 μm) / polyethylene resin composition (110 μm) / fossil fuel-derived z-C4LLDPE (10 μm). A sealant film and a pouch were produced in the same manner as in Example 1 except that they were produced as a film, and evaluated in the same manner.

[Comparative Example 1]
A polyethylene resin composition 2 was obtained by the same operation as in Example 1 except that fossil fuel-derived m-C6LLDPE1 was changed to fossil fuel-derived m-C6LLDPE2, and a sealant film and a pouch were produced and evaluated in the same manner. , the results are shown in Table 1.
However, in Comparative Example 1, the panel material had the following structure.
Body material: nylon film 1 (25 μm)/printed layer/adhesive layer/sealant film (120 μm)

[Summary of evaluation results]
In all of the examples, the sealant films exhibited excellent breaking strength, yield strength, elongation at break, tear strength and blocking resistance; the packaging materials exhibited excellent sealing and lamination strength; the pouches exhibited excellent drop impact resistance and , showed better hand-cutting properties than Comparative Example 1.

<Evaluation method>
[Tensile test]
The sealant film was subjected to a tensile test according to JIS Z 1702 to measure the breaking strength, yield strength, and breaking elongation in the MD direction (machine direction) and TD direction (width direction).
[Tear strength]
The tear strength of the sealant film in the MD direction (machine direction) and TD direction (width direction) was measured according to JIS K 7128-2 (Elmendorf tear method).

[Sliding angle]
For the sealant film, using a measuring instrument manufactured by Toyo Seiki Seisakusho (model number: friction measuring instrument AN), in accordance with JIS P 8147: 2010 "8 Inclination method", when measuring the static friction coefficient of the test piece The inclination angle of the inclined plate was measured when the sliding distance reached 55 mm. Measurement was performed 10 times, and the average value was obtained.
Dimensions of the lower test piece: width 90 mm x length 200 mm
Dimensions of the upper test piece: width 60 mm x length 100 mm
Weight dimensions on the upper test piece: width 60 mm x length 100 mm
Inclined plate tilt angle change speed: 3°/sec

[Blocking resistance]
A roll was produced using the obtained sealant film, stored in a constant temperature room at a temperature of 43° C. and a relative humidity of 40% for 5 days, and then the surface state and rewinding property were observed and evaluated according to the following criteria.
A: There was no blocking between films at all. B: There was some blocking between films, but it does not pose a problem in practice.
C: Peeling and rewinding could not be performed due to blocking between films.

[Seal strength]
Cut the packaging material for the body material and the bottom material into 10 cm × 10 cm pieces, fold them in half and overlap them, and use a heat seal tester (manufactured by Tester Sangyo Co., Ltd.: TP-701-A) to measure a 1 cm × 10 cm area under the following conditions. The sample was heat-sealed with , and the end portion was not heat-sealed and was not adhered, and the sample was divided into two parts.
Heat sealing temperature: 160°C
Heat sealing pressure: 1 kgf/cm ²
Heat sealing time: 1 second This sample was cut into strips with a width of 15 mm, each bifurcated end 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]
A packaging material for the panel was cut into 15 mm x 100 mm pieces, and the sealant layer and the base material layer were peeled off at the ends to prepare samples in a state of being bifurcated.
Using a heat seal tester (manufactured by Tester Sangyo Co., Ltd.: TP-701-A), this sample is attached to a tensile tester at each bifurcated end, and tensile strength (N / 15 mm) under the following conditions. was measured.
Tensile test speed: 300mm/min Tensile load range: 50N

[Drop impact resistance]
Each of 10 pouches was filled with 360ml of water and dropped vertically (bottom down) 10 times and horizontally (surface down) 10 times from a height of 1.2m to check for bag breakage and seal retraction. . Evaluation was performed 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 seal retraction was observed.
◯: Retraction of the seal was observed very rarely.
Δ: Retraction of the seal was observed.
x: Bag breakage was observed.

[Hand cutting]
10 pouches were opened from the notch portion along the laser line, and the presence or absence of catching and elongation of the sealant film at the start of opening was checked. Evaluation was carried out by dividing two by five people.
⊚: Neither sticking nor elongation of the sealant was observed.
◯: Compared to ⊚, there was slight catching or there was slight elongation.
Δ: There was slight catching or there was slight elongation.
x: There was catch or elongation.

1 Sealant film 2 Layer made of polyethylene resin composition 3 Layers 11, 11' made of arbitrary resin composition Wall film 12 Bottom film folded parts 13a, 13b Bottom film notch part 14 Gusset part 15 Bottom seal parts 16a, 16b Side seal portion 17 Spout portion seal portion 18 Top seal portions 19a, 19b Notch portion 20 Spout portion 21 Half-cut line 22 Notch 100 Refill 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 entire polyethylene-based resin composition is greater than 2 and 5 or less,
C6 linear low-density polyethylene having a density of 0.938 g/cm ³ or more and less than 0.950 g/cm ³ ,
A polyethylene resin composition. The plant-derived polyethylene-based resin is a plant-derived linear low-density polyethylene-based resin and/or a plant-derived low-density polyethylene-based resin,
The polyethylene-based resin composition according to claim 1. The content of the C4 linear low-density polyethylene in the entire polyethylene-based resin composition is greater than 45% by mass and 70% by mass or less,
The polyethylene-based resin composition according to claim 1 or 2. The polyethylene-based resin composition contains a low-density polyethylene- based resin ,
The mass ratio of the C4 linear low density polyethylene and C6 linear low density polyethylene /low density polyethylene resin in the entire polyethylene resin composition is 1 or more and 7 or less,
The polyethylene resin composition according to any one of claims 1 to 3. The mass ratio of the C4 linear low density polyethylene and the C6 linear low density polyethylene /the low density polyethylene resin in the entire polyethylene resin composition is 2 or more and 5 or less,
The polyethylene-based resin composition according to claim 4. The total content of the C4 linear low-density polyethylene and the C6 linear low-density polyethylene in the entire 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. Characterized by containing 10% by mass or more and 50% by mass or less of plant-derived C4 linear low-density polyethylene in the entire polyethylene-based resin composition,
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 includes 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, and consisting of a single layer or a plurality of layers of two or more layers. the film. A sealant film for a packaging material having a multi-layer structure of two or more layers produced by coextrusion,
A layer formed from the polyethylene resin composition according to any one of claims 1 to 8, in the total sealant film, in a range of 40% by mass or more and 100% by mass or less, 1 layer or 2 layers characterized by comprising
Sealant film for packaging materials. A sealant film for packaging materials having a multi-layer structure of three or more layers,
Both outermost layers do not contain the plant-derived polyethylene resin,
Sealant film for packaging material according to claim 9 or 10 characterized by a biomass degree of 10% or more and 50% or less,
A sealant film for packaging materials according to any one of claims 9 to 11. A laminate for packaging material, comprising a substrate 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. characterized by comprising a layer in which the film is laminated by pasting via an adhesive,
Laminates for packaging materials. A packaging material, characterized in that it is made from the laminate according to claim 13 . A package, characterized in that it is made from the packaging material according to claim 14.

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