JP2019147381A - Sealant film, and package material and package bag using the same - Google Patents

Abstract

To provide a sealant film exhibiting high laminate strength with a substrate layer, excellent in slipperiness, exhibiting high biomass degree as a whole film and low in load to environment.SOLUTION: There is provided a sealant film consisting of a layer 1 used by laminating on a substrate layer, consisting of one or more petroleum-derived polyethylene resin and one or more layer 2 consisting of a plant-derived polyethylene resin, in which an outermost surface layer forming a substrate layer laminate consists of the layer 1 consisting of the petroleum-derived polyethylene resin, the petroleum-derived polyethylene resin has area percentage of a low molecular weight area with molecular weight of 1000 or less in a molecular weight distribution figure by a gel permeation chromatography method of 0.5 area% based on all peak areas and biomass degree of whole film of 45 to 80%.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sealant film comprising a plant-derived polyethylene-based resin, and a packaging material and a packaging bag using the same, and more specifically, while exhibiting a high degree of biomass, it exhibits a high laminate strength with an adjacent layer, Moreover, the present invention relates to a sealant film excellent in slipperiness, and a packaging material and a packaging bag using the same.

  In recent years, in order to reduce the burden on the environment, a part of the raw material of the resin film can be replaced with a resin mainly composed of plant-derived components (hereinafter referred to as “plant-derived resin”) from a resin derived from petroleum. It has been studied (Patent Document 1). The plant-derived resin is expected to have the same physical properties as the conventional petroleum-derived resin without any change in chemical structure.

  However, in reality, a resin film containing a plant-derived resin, for example, a sealant film containing a plant-derived polyethylene resin, exhibits different properties from a sealant film made only of petroleum-derived polyethylene resin.

  For example, in a sealant film comprising a petroleum-derived polyethylene resin, when a part of the raw polyethylene resin is changed to a plant-derived polyethylene resin, the base material is laminated thereon as the blending ratio increases. It was found that the laminate strength with the layer was lowered and delamination was likely to occur.

Therefore, it has been difficult to achieve both a high laminate strength with the base material layer and a high degree of biomass.
In contrast to this problem, the presence of a bleed-out inhibitor in the sealant film was able to increase the laminate strength with the base material layer, but on the other hand, there was a problem that the slipperiness was lowered.

  And, since the slipperiness of the sealant film is lowered, a so-called blocking phenomenon occurs in which the films adhere to each other in the film forming process, the slit process, the bag making process, the content filling process, etc. When stored for a long period of time or in a high temperature state, the developability of the film is deteriorated at the time of use, and bag-making workability, filling workability and the like are remarkably lowered.

JP 2009-155516 A

  The present invention solves the above-mentioned problems, shows a high laminate strength with the base material layer, is excellent in slipperiness, and exhibits a high degree of biomass of at least 45% as a whole film, thereby reducing the burden on the environment. It is an object of the present invention to provide a sealed sealant film, and a packaging material and a packaging bag using the same.

As a result of various studies, the present inventor has found that the decrease in laminate strength that occurs as the blending ratio of plant-derived polyethylene resin increases, the low molecular weight compounds in the plant-derived polyethylene resin, such as monomers and oligomers, on the film surface It was found that this was caused by bleed out (precipitation). Furthermore, in the sealant film containing the plant-derived polyethylene resin, the base material layer lamination surface is covered with a layer made of a petroleum-derived polyethylene resin containing almost no low molecular weight component, thereby reducing the slipperiness. It has been found that bleeding out of the low molecular weight compound in the plant-derived resin to the substrate layer lamination surface can be prevented, and the laminate strength with the substrate layer can be increased.

The present invention is characterized by the following points.
1. A sealant film used by being laminated on a base material layer, comprising a layer made of one or more petroleum-derived polyethylene resins and a layer made of one or more plant-derived polyethylene resins. The outermost layer forming the base material layer laminated surface is a layer made of petroleum-derived polyethylene resin, and the petroleum-derived polyethylene resin is a molecular weight distribution diagram obtained by the gel permeation chromatography (GPC) method. , The area ratio of the low molecular weight region having a molecular weight of 1,000 or less is 0.5 area% with respect to the total peak area.
The above-mentioned sealant film, wherein the degree of biomass of the entire sealant film is 45 to 80%.
2. A two-layer laminated film comprising a layer made of a petroleum-derived polyethylene resin of 2.1 layers and a layer made of a single plant-derived polyethylene resin. The sealant film described in 1.
3. A three-layer laminated film comprising a layer composed of two layers of a petroleum-derived polyethylene-based resin and a layer composed of one layer of a plant-derived polyethylene-based resin, the outermost layer forming the base material layer laminated surface, and The outermost layer forming the heat seal surface on the opposite side is a layer made of a petroleum-derived polyethylene resin, and the intermediate layer therebetween is a layer made of a plant-derived polyethylene resin. The sealant film described in 1.
4). A base material layer and the above-mentioned 1. ~ 3. And a layer made of the sealant film according to any one of the above.
5. 4. above. A packaging bag using the packaging material described in 1.
6). 4. A refilling standing pouch, characterized in that 5. Packaging bag as described in.

The sealant film of the present invention contains a plant-derived resin at a high blending ratio, that is, has a high degree of biomass. Therefore, from the viewpoint of carbon neutral, the increase in the amount of CO _{2 in} the atmosphere is suppressed, and the use of petroleum resources is also saved.

Carbon neutral means that even if a plant is burned, the amount of CO ₂ emitted at that time is equal to the amount of CO ₂ absorbed by the plant during growth, so it affects the increase or decrease in the amount of CO _{2 in} the atmosphere. It means not. Therefore, an increase in the amount of CO ₂ can be suppressed as the amount of plant-derived materials increases.

  In addition, the sealant film of the present invention has little change in various physical properties of the film surface even after the film has been stored for a long period of time, for example, after being exposed to sunlight for a long time, and is high in the base material layer. It exhibits laminate strength and excellent slipperiness, and is less likely to cause deterioration with time, delamination associated therewith, adhesion between films, and the like. That is, it shows excellent weather resistance.

  Furthermore, in the present invention, since the outermost layer forming the base material layer laminated surface is a layer made of petroleum-derived polyethylene resin containing almost no low molecular weight component, the film surface of the low molecular weight compound in the plant-derived polyethylene resin The bleed-out upward can be prevented very effectively.

In particular, in the outermost layer that forms the base material layer laminated surface, the petroleum-derived polyethylene resin constituting this has a peak area ratio occupied by low molecular weight components having a molecular weight of 1000 or less in the molecular weight distribution diagram obtained by GPC. It is 0.5 area% or less with respect to the area. As a result, even if the outermost layer is thin, it effectively blocks the permeation of low molecular weight compounds in the plant-derived polyethylene resin and adsorbs the slip agent added to the sealant film. And does not cause a decrease in slipperiness. Therefore, the sealant film of the present invention can achieve a biomass degree as high as 80%, exhibits a high lamination strength with the base material layer, and exhibits excellent slipperiness.

  Further, the outermost layer forming the base material layer laminated surface is made of a petroleum-derived polyethylene resin, and various physical properties have been developed as the petroleum-derived polyethylene resin. Therefore, the petroleum-derived polyethylene resin that forms the base material layer laminate surface can be appropriately selected from a wide variety of options, and the adjustment of the laminate strength with the base material layer, the lamination conditions, and the like is facilitated.

  In addition, when the outermost layer forming the heat seal surface is a layer made of petroleum-derived polyethylene resin, the petroleum-derived polyethylene suitable for the desired heat seal strength and heat seal conditions is selected from a wide variety of options. The resin can be appropriately selected.

  Furthermore, the packaging material and the packaging bag comprising the sealant film and the base material layer of the present invention can suppress a decrease in interlayer adhesion even after being subjected to the heating / cooling process, and have excellent bag-making workability and the like. In order to show, it is useful as various packaging materials.

It is a schematic sectional drawing which shows the example about the layer structure of the sealant film of this invention. It is a schematic sectional drawing which shows another example about the layer structure of the sealant film of this invention. It is a schematic sectional drawing which shows the example about the layer structure of the packaging material of this invention.

  The above-described present invention will be described in more detail below. Hereinafter, the resin names used in the present invention are those commonly used in the industry. In the present invention, the density is a value measured according to JIS-K7112. MFR is a value measured according to JIS-K7210.

<I> Layer Configuration of Sealant Film of the Present Invention FIG. 1 is a schematic sectional view showing an example of the layer configuration of the sealant film of the present invention. As shown in FIG. 1, the sealant film of the present invention has an arbitrary base material layer laminated on one surface thereof, that is, the base material layer lamination surface [A], and the other surface is a heat seal surface [ B] is overlapped with an arbitrary adherend and heat sealed. In the following specification, the surface of the sealant film that contacts the base material layer is referred to as “base material layer lamination surface”, and the surface of the sealant film that contacts the adherend is referred to as “heat seal surface”.

  Here, the sealant film is a two-layer laminated film comprising a layer [1] composed of one layer of petroleum-derived polyethylene resin and a layer [2] composed of one layer of plant-derived polyethylene resin. The petroleum-derived polyethylene resin constituting the layer [1] forming the base material layer laminated surface is such that, in the molecular weight distribution diagram obtained by the GPC method, the area ratio of the low molecular weight region having a molecular weight of 1000 or less is the total peak area In contrast, 0.5% by area or less is used.

With the above configuration, while exhibiting good laminate strength and excellent slipperiness with the base material layer,
And the sealant film which shows a high degree of biomass can be manufactured simply and at low cost with good productivity.

  FIG. 2 is a schematic cross-sectional view showing an example of the layer structure of the sealant film of the present invention. As shown in FIG. 2, the sealant film of the present invention comprises two layers [1, 3] made of petroleum-derived polyethylene resin and a layer [2] made of plant-derived polyethylene resin sandwiched between them. A three-layer laminated film may be used. And the petroleum origin polyethylene-type resin which comprises layer [1] which forms this base material layer lamination surface consists of a resin composition similar to the sealant film shown by said FIG. On the other hand, the layer [3] forming the heat seal surface may be made of any petroleum-derived polyethylene resin. With this configuration, it is possible to produce a sealant film that exhibits a high degree of biomass while exhibiting good laminate strength with the base material layer, excellent slipperiness, and good heat sealability.

  FIG. 3 is a schematic cross-sectional view showing an example of the layer structure of the packaging material of the present invention. As FIG. 3 shows, the packaging material of this invention laminates | stacks base material layer [4] on the base material layer lamination surface of the sealant film of this invention.

  The sealant film of the present invention may have any thickness depending on its use, desired seal strength, degree of biomass to be achieved, desired weather resistance, etc., but generally about 5 to 200 μm as a sealant film. The thickness is preferably 20 to 150 μm. Moreover, when the use is a packaging bag of a weight bag or a refilling standing pouch, the thickness is preferably 100 to 150 μm.

  And in this sealant film, the ratio of the thickness of each layer is set so that the biomass degree of the whole sealant film is 45 to 80%, more preferably 50 to 80%. The higher the ratio of the thickness of the layer made of plant-derived polyethylene resin, the higher the degree of biomass is achieved. However, when this layer is too thick compared to the layer [1] made of petroleum-derived polyethylene resin forming the base layer laminated surface, and the degree of biomass exceeds 80%, the low molecular weight compound on the film surface Bleed-out cannot be sufficiently prevented, and a desired laminate strength cannot be obtained when the base material layers are laminated.

The layer thickness [1] of the petroleum-derived polyethylene resin forming the base material layer laminated surface is at least 0.1 μm, and preferably 3 μm or more in the case of a weight bag or a packaging bag for a refilling standing pouch. And the thickness of the entire sealant film is 45 to 80%.

<II> Layer Consisting of Plant-Derived Polyethylene Resin In the present invention, “plant-derived” means that carbon derived from a plant raw material produced from an alcohol obtained using a plant as a raw material is included.

  In the present invention, the plant-derived polyethylene resin is a homopolymer of plant-derived ethylene derived from bioethanol obtained from a plant raw material, or a copolymer of the plant-derived ethylene and a small amount of another comonomer. .

Specifically, high density polyethylene (HDPE, density 0.940 g / cm ³ or more) obtained by polymerizing ethylene derived from bioethanol, medium density polyethylene (MDPE, density 0.925 or more and 0.940 g / cm ³ or more). Less than ³ ), high pressure low density polyethylene (LDPE,
Density less than 0.925 g / cm ³ ), linear low density polyethylene (LLDPE, density 0.91)
0 to 0.925 g / cm ³ , a copolymer of ethylene and α-olefin), and mixtures thereof.

  For example, for application to a sealant for a weight bag or a standing pouch, it is particularly preferable to use plant-derived LLDPE because an appropriate waist is obtained for the film and excellent impact resistance is obtained.

  Examples of the α-olefin serving as a comonomer of the LLDPE include α-olefins having 3 to 20 carbon atoms such as propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-nonene and 4-methylpentene. Etc., and mixtures thereof. These α-olefins may be plant-derived α-olefins derived from bioethanol or non-plant-derived, that is, petroleum-derived α-olefins. Since a wide variety of petroleum-derived α-olefins are available, the physical properties and the like of polyethylene resins can be easily adjusted by using these. By using the plant-derived α-olefin, the biomass degree of the final product can be further increased.

  As a method for producing plant-derived ethylene and plant-derived α-olefin, bioethanol is produced by fermenting sugar solution and starch obtained from plants such as sugarcane, corn, and sweet potato with microorganisms such as yeast according to conventional methods. Then, this is heated in the presence of a catalyst, and plant-derived ethylene and plant-derived α-olefin (1-butene, 1-hexene, etc.) can be obtained by intramolecular dehydration reaction or the like. Subsequently, using the obtained plant-derived ethylene and plant-derived α-olefin, a plant-derived polyethylene resin can be produced in the same manner as in the production of a petroleum-derived polyethylene resin.

The method for producing plant-derived ethylene, plant-derived α-olefin and plant-derived polyethylene resin is described in detail in, for example, JP-T-2011-506628.
Examples of the plant-derived polyethylene resin suitably used in the present invention include Green PE manufactured by Braskem SA.

  In the sealant film of the present invention, the “layer comprising a plant-derived polyethylene resin” is a layer obtained by melting the plant-derived polyethylene resin and coextruding it with a multilayer material resin. Here, in the plant-derived polyethylene-based resin, a small amount of, for example, 5% by mass or less of an additive, specifically, a slip agent (lubricant), if necessary, within a range not impairing the effects of the present invention. , Antistatic agent, flame retardant, anti-blocking agent, crystallization accelerator, stabilizer (anti-aging agent, antioxidant, ozone degradation inhibitor, UV absorber, light stabilizer, etc.), tackifier, softener Coloring agents, coupling agents, preservatives, fungicides and the like may be added.

<III> Layer made of petroleum-derived polyethylene resin In the present invention, “petroleum-derived” does not include carbon derived from plant raw materials, and is derived from ethylene obtained by thermally decomposing naphtha obtained from petroleum as usual. The main component is the structure to be The “petroleum-derived polyethylene resin” refers to any polyethylene resin generally used as a sealant film having heat sealability.

More specifically, it is a homopolymer of petroleum-derived ethylene, or a copolymer of petroleum-derived ethylene and a small amount of another comonomer, and includes HDPE (density 0.940 g / cm ³ or more), MDPE (density 0.00). less 925 than 0.940g / cm ^3), LDPE (density less than 0.925g / cm ^3), LLDPE (density 0.910~0.925g / cm ^3, a copolymer of ethylene and α- olefin), and Mention may be made of these mixtures. Examples of the α-olefin serving as a comonomer of the LLDPE include α-olefins having 3 to 20 carbon atoms such as propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-nonene and 4-methylpentene. Etc., and mixtures thereof.

  In the sealant film of the present invention, as the petroleum-derived polyethylene resin constituting the outermost layer that forms the base material layer laminated surface, a petroleum-derived polyethylene resin that contains almost no low molecular weight component is used, in particular, a low molecular weight of 1000 or less. In the molecular weight distribution chart obtained by GPC, the molecular weight component ratio is 0.5 area% or less, more preferably 0.3 area% or less. Here, most of the low molecular weight components having a molecular weight of 1000 or less are melt-decomposed products and unreacted products of petroleum-derived polyethylene resins.

  Such a layer made of petroleum-derived polyethylene resin effectively blocks the permeation of low molecular weight compounds in plant-derived polyethylene resin, even with a thin layer thickness, and has a slip agent added to the sealant film. It does not adsorb and does not cause slippage. Therefore, the sealant film of the present invention can achieve a biomass degree as high as 80%, exhibits a high lamination strength with the base material layer, and exhibits excellent slipperiness.

Here, in the petroleum-derived polyethylene resin constituting the outermost layer forming the base material layer laminated surface, when the proportion of the low molecular weight component having a molecular weight of 1000 or less is more than 0.5 area%, the low in the plant-derived polyethylene resin. The effect of preventing the permeation of molecular compounds is inferior, which is not preferable.

  The ratio (area%) of the low molecular weight component is the ratio of the area occupied by a peak having a molecular weight of 1000 or less to the total peak area in a differential molecular weight distribution diagram composed of a differential molecular weight distribution curve obtained by the GPC method. Here, the horizontal axis of the differential molecular weight distribution chart is the molecular weight (logarithmic value) obtained using polystyrene as a standard substance, and the vertical axis is the value obtained by differentiating the concentration fraction with the logarithmic value of molecular weight. is there.

Specific measurement conditions for the GPC method are as shown in the examples.
Further, the petroleum-derived polyethylene resin forming the base layer laminated surface may be a resin composition comprising any petroleum-derived polyethylene, for example, HDPE, MDPE, LDPE, LLDPE, and a mixture thereof. From the viewpoint of impact and prevention of permeation of low molecular weight compounds in plant-derived polyethylene resins, petroleum-derived LLDPE is 15 to 100% by mass, preferably 50 to 100%, more preferably 60 to 100% by mass, and other petroleum-derived polyethylene. It is a resin composition containing 0 to 85% by weight, preferably 0 to 50% by weight, more preferably 0 to 40% by weight, based on a series resin such as LDPE, MDPE and HDPE.

  Moreover, in the said resin composition, there exists an advantage that it is excellent in hand cutting property by mixing and using petroleum origin LLDPE and petroleum origin LDPE. On the other hand, by using petroleum-derived LLDPE alone, there is an advantage that the impact resistance and the effect of preventing permeation of a low molecular compound in the plant-derived polyethylene resin are further enhanced.

  Further, in the above resin composition, as the petroleum-derived LLDPE, those produced using any of the Ziegler-based catalyst and the metallocene catalyst can be used, but since the production of low molecular weight components is small, the metallocene catalyst is used. The petroleum-derived LLDPE produced in this way is more preferably used.

  In the sealant film of the present invention, the petroleum-derived polyethylene resin constituting the outermost layer that forms the base layer laminated surface, for example, the outermost layer that forms the heat seal surface, can be selected from any polyethylene resin, and those skilled in the art. Can be appropriately selected and used.

  Further, in any layer, the petroleum-derived polyethylene resin may have any property, and depending on the type of the base material layer and the adherend to be laminated in the subsequent step, a desired Those skilled in the art can appropriately determine the seal strength, hot tackiness, heat seal conditions to be selected, and the like.

  For example, it is particularly preferable to use petroleum-derived LLDPE alone or a mixture of petroleum-derived LLDPE and petroleum-derived LDPE in order to apply to a sealant of a weight bag or a standing pouch. Thereby, a moderate waist is obtained for the film, and excellent impact resistance is obtained. Further, as a material resin for a layer made of petroleum-derived polyethylene resin, petroleum-derived LLDPE or a mixture of petroleum-derived LLDPE and petroleum-derived LDPE is used, and further, as a material resin for a layer made of plant-derived polyethylene resin, By using the derived LLDPE, the adhesion between the respective layers of the sealant film is increased, which is more preferable.

  In the sealant film of the present invention, the “layer made of petroleum-derived polyethylene resin” is a layer obtained by melting the above-described petroleum-derived polyethylene resin and coextruding it with the material resin of the other layer. Here, in the petroleum-derived polyethylene-based resin, a small amount of, for example, 5% by mass or less of an additive, specifically, a slip agent (lubricant) is included in the range not impairing the effects of the present invention. , Antistatic agent, flame retardant, anti-blocking agent, crystallization accelerator, stabilizer (anti-aging agent, antioxidant, ozone degradation inhibitor, UV absorber, light stabilizer, etc.), tackifier, softener Coloring agents, coupling agents, preservatives, fungicides and the like may be added.

<IV> Film Formation The sealant film of the present invention can be produced by preparing a resin or a resin composition constituting each layer, co-extrusion using a conventional film forming method after melt kneading.
The resin film is required to have slipperiness to ensure processability. And if necessary, slipperiness imparting agents such as slip agents and antistatic agents are blended in the film to improve the slipperiness. However, the improvement in slipperiness generally results in a decrease in the laminate strength of the film.

  With respect to this problem, the sealant film of the present invention has a layer made of a petroleum-derived polyethylene resin as the outermost layer forming the base material layer lamination surface. Even when the sealant film of the present invention contains a slipping agent such as a slip agent, this layer suppresses bleed-out of the low molecular weight compound contained in the plant-derived polyethylene resin to the base material layer lamination surface. And the effect of a slipperiness | lubricity imparting agent is not inhibited. Therefore, the sealant film of the present invention can exhibit excellent slipperiness while exhibiting high laminate strength.

<V> Base Material Layer The sealant film of the present invention can be used as a laminate in which various base material layers are laminated depending on the application.
The base material laminated on the sealant film of the present invention may be metals, ceramics, woods, papers, etc., but in the field of packaging materials, films and / or papers composed of thermoplastic resins. In many cases.

  The thermoplastic resin constituting the base material includes olefin resins (polyethylene resins, polypropylene resins, etc.), halogen-containing resins (vinyl chloride resins, etc.), vinyl alcohol resins, (meth) acrylic resins, styrene resins. Resins, polyester resins (polyalkylene arylate resins such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, etc.), polyamide resins (polyamide 6, polyamide 66, etc.), polycarbonate resins, polysulfone resins (polyether sulfone, Examples thereof include polysulfone), polyphenylene ether resins, and cellulose esters.

Furthermore, in order to increase the degree of biomass, the substrate film may also be a plant-derived resin film. Such a film can be composed of a polylactic acid resin, a polyester resin, a polyamide resin, or the like. These films may be formed of a single thermoplastic resin, or may be a composite (alloy film) or a laminate composed of two or more thermoplastic resins.

Of these films, a polypropylene resin film, a polyester resin film, a polyamide resin film, a polylactic acid resin film, and the like are often used.
These base films may be unstretched or may be uniaxial or biaxially stretched films.

  These base films may be composite films in which two or more are laminated. Furthermore, an arbitrary barrier film, for example, a material having a property of shielding light such as sunlight or a property of not allowing gas such as water vapor, water, oxygen, etc. to pass through may be used.

  Specifically, for example, a metal foil such as an aluminum foil, a resin film having a deposited film such as aluminum, a silicon oxide having a barrier property, a resin film having a deposited film of an inorganic oxide such as aluminum oxide, water vapor, water, etc. Resin film having barrier properties, polyvinyl alcohol having gas barrier properties, saponified ethylene-vinyl acetate copolymer, resin such as MXD6 nylon, and light-shielding property obtained by kneading the resin with colorants such as pigments. Various colored resin films and the like can be used.

  Furthermore, the laminated surface of these base films may be subjected to surface treatment (for example, corona discharge treatment, anchor coat treatment, primer treatment, etc.) in order to enhance the adhesion with the sealant film of the present invention. The thickness of the base film is not particularly limited, and can be selected from the range of usually about 1 μm to 2 mm, preferably about 5 μm to 1 mm according to the application.

<VI> Lamination Lamination of the base material layer and the sealant film can be bonded by a dry lamination method via an adhesive. Examples of the adhesive to be used include a two-component curable polyurethane adhesive for dry lamination.

  It can also be bonded by an extrusion laminating method (so-called sandwich laminating method) through an adhesive layer. In this case, as the adhesive layer, a polyolefin-based heat-adhesive resin, for example, LDPE, ethylene-methacrylic acid copolymer, ethylene-acrylic acid copolymer, ionomer alone, or hard resin A resin blended with an adhesion improver can be used.

Furthermore, it can also laminate | stack by carrying out extrusion coating of resin which comprises the sealant film of this invention on a base film.
In the further aspect of this invention, you may provide printing layers, such as a character, a figure, a symbol, and a design, on a base film or between a sealant film and a base film.
By using an adhesive or printing ink used above that contains a plant-derived resin, the degree of biomass can be further increased.

<VII> Packaging Material The laminated film having the base material layer and the sealant film of the present invention can be suitably used as a packaging material such as a lid material or a packaging bag. For example, the laminated film is folded in two, or two laminated films are prepared, and the surfaces of the sealant film are overlapped with each other, and the peripheral end portion thereof is, for example, a side seal type, two-side seal Heat seal with heat seal forms such as mold, three-side seal type, four-side seal type, envelope sticker seal type, palm seal sticker type (pillow seal type), pleated seal type, flat bottom seal type, square bottom seal type, gusset type Thus, various types of packaging bags can be obtained.

  In the above, as a heat sealing method, for example, a known method such as a bar seal, a rotary roll seal, a belt seal, an impulse seal, a high frequency seal, and an ultrasonic seal can be used.

  The sealant film of the present invention exhibits a high degree of biomass but also exhibits an adjacent base material layer and a high laminate strength, and also exhibits excellent slipperiness. Therefore, it can be suitably used as a packaging material for various purposes. In particular, the packaging material using the sealant film of the present invention can be suitably used as a weight bag or a refilling standing pouch having a large internal capacity with respect to the area of the film used.

<VIII> Biomass Degree “Biomass Degree” is an index that represents the mixing ratio of petroleum-derived raw materials and plant-derived raw materials (biomass), and is determined by measuring the concentration of radioactive carbon (C ¹⁴ ). Is represented by the following formula.
Biomass degree (%) = C ¹⁴ concentration (pMC) × 0.935
The C ¹⁴ is during a plant-derived raw material include a constant concentration, hardly present in petroleum trapped underground. Therefore, by measuring the C ¹⁴ concentration by accelerator mass spectrometry, it can be used as an index of the content ratio of plant-derived raw materials.

  The sealant film of the present invention has excellent weather resistance and high lamination strength with an adjacent layer, but contains a plant-derived resin at a high blending ratio, and has a high biomass of 45 to 80%, more preferably 50 to 80%. Degree can be shown. If the layer made of plant-derived polyethylene resin is thickened so that the degree of biomass exceeds 80%, bleeding out to the film surface cannot be sufficiently prevented, and a desired laminate strength can be obtained when the base material layer is laminated. I can't.

In the present invention, the C ¹⁴ concentration in the film is measured as follows. That is, the sample to be measured is burned to generate carbon dioxide, and the carbon dioxide purified in the vacuum line is reduced with hydrogen using iron as a catalyst to purify graphite. Then, this graphite is mounted on a C ¹⁴ -AMS dedicated device (manufactured by NEC) based on a tandem accelerator, and C ¹⁴ count, C ¹³ concentration (C ¹³ / C ¹² ), C ¹⁴ concentration ( was measured in the C ¹⁴ / C ^12), calculates the ratio of the C ¹⁴ concentration of the sample carbon to standard modern carbon from the measurement value. As a standard sample, oxalic acid (HOXII) provided by the National Bureau of Standards (NIST) is used.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

[GPC method]
In the present invention, the molecular weight distribution of the petroleum-derived polyethylene resin and the proportion of the low molecular weight component were measured by GPC under the following conditions.
Apparatus: GPC-150 manufactured by Waters
Column: GPC HT-806m x 2 manufactured by Showa Denko KK, HT-803 x 1 eluent: dichlorobenzene (140 ° C)
Flow rate: 1 mL / min Sample concentration: 1 g / L
Injection volume: 5 mL
Detector: Infrared spectrometer Measurement temperature: 0 to 140 ° C
Reference material: Polystyrene

[Example 1]
Petroleum-derived LLDPE (Evolue SP2020, Prime Polymer Co., Ltd., density 0.9)
16 kg / m ³ , MFR = 2.3 g / 10 min) 70% by mass, petroleum-derived LDPE (LDPE-F120N manufactured by Ube Maruzen Polyethylene Co., Ltd., density 0.920 kg / m ³ , MFR = 1.2 g)
/ 10 minutes) 29% by mass and 1% by mass of a slip agent (M-3, manufactured by Nippon Unicar Co., Ltd.) were sufficiently melt-kneaded to prepare a first resin composition. The proportion of low molecular weight components having a molecular weight of 1000 or less in the first resin composition was 0.5 area%.

In addition, plant-derived LLDPE (C4-SLL118 manufactured by Brasschem, density 0.916 kg
/ M ³ , MFR = 1.0 g / 10 min, biomass degree 87%) 99% by mass and slip agent (M-3 manufactured by Nihon Unicar Co., Ltd.) 1% by mass are sufficiently melt-kneaded to obtain a second resin. The composition was adjusted.

  Using the first and second resin compositions, a film was formed by a top-blown air-cooled inflation coextrusion film forming machine, and the first resin composition (base material layer laminated surface, thickness 25 μm) / second resin composition The sealant film of the present invention was produced, consisting of three layers of product (intermediate layer, thickness 70 μm) / first resin composition (heat seal surface, thickness 25 μm). The degree of biomass was 50%.

[Example 2]
In the first resin composition, instead of petroleum-derived LLDPE (Prime Polymer Evolue SP2020), petroleum-derived LLDPE (Prime Polymer Evolue SP1540, density 0.913 kg / m ³ , MFR = 3. The sealant film of the present invention was produced in the same manner as in Example 1 except that 8 g / 10 min) was used. The ratio of low molecular weight components having a molecular weight of 1000 or less in the first resin composition was 0.3 area%. Further, the biomass degree was 50%.

[Example 3]
Petroleum-derived LLDPE (Evolue SP2020, Prime Polymer Co., Ltd., density 0.9)
16 kg / m ³ , MFR = 2.3 g / 10 minutes) 99% by mass and 1% by mass of a slip agent (M-3, manufactured by Nippon Unicar Co., Ltd.) are sufficiently melt-kneaded to prepare a first resin composition. did. The ratio of the low molecular weight component having a molecular weight of 1000 or less in the first resin composition was 0.4 area%.

In addition, plant-derived LLDPE (C4-SLL118 manufactured by Brasschem, density 0.916 kg
/ M ³ , MFR = 1.0 g / 10 min, biomass degree 87%) 99% by mass and slip agent (M-3 manufactured by Nihon Unicar Co., Ltd.) 1% by mass are sufficiently melt-kneaded to obtain a second resin. The composition was adjusted.

  Using the first and second resin compositions, a film is formed by a top-blown air-cooled inflation coextrusion film-forming machine, and the first resin composition (base layer laminated surface, thickness 10 μm) / second resin composition A sealant film of the present invention consisting of two layers of a product (heat seal surface, thickness 120 μm) was produced. The degree of biomass was 80%.

[Comparative Example 1]
In the first resin composition, instead of petroleum-derived LLDPE (Evolue SP2020 manufactured by Prime Polymer Co., Ltd.), petroleum-derived LLDPE (Prime Polymer Ultra-Zex 2022L, density 0.919 kg / m ³ , MFR = 2) A sealant film was produced in the same manner as in Example 1 except that 0.0 g / 10 min) was used. The ratio of low molecular weight components having a molecular weight of 1000 or less in the first resin composition was 0.6 area%. Further, the biomass degree was 50%.

[Comparative Example 2]
In the first resin composition, instead of petroleum-derived LLDPE (Evolue SP2020 manufactured by Prime Polymer Co., Ltd.), petroleum-derived LDPE (Novatec LD manufactured by Nippon Polyethylene Co., Ltd., LC600A density 0.918 kg / m ³ , MFR = 7 A sealant film was produced in the same manner as in Example 3, except that 0.2 g / 10 min) was used. The proportion of low molecular weight components having a molecular weight of 1000 or less in the first resin composition was 3.3 area%. Further, the biomass degree was 80%.

[Comparative Example 3]
Plant-derived LLDPE (C4-SLL118 manufactured by Brasschem, density 0.916 kg / m ³ , MFR = 1.0 g / 10 min, biomass degree 87%) 58% by mass, petroleum-derived LLDPE ((
Evolue SP2020 made by Prime Polymer, density 0.916kg / m ³ , MFR = 2.3g / 10min) 12% by mass, petroleum-derived LDPE (made by Ube Maruzen Polyethylene Co., Ltd.)
E-F120N, density 0.920 kg / m ³ , MFR = 1.2 g / 10 min) 29 mass%, and slip agent (M-3 manufactured by Nihon Unicar Co., Ltd.) 1 mass% were sufficiently melt-kneaded to obtain The obtained resin composition was formed into a film by a top blow air-cooled inflation coextrusion film forming machine to produce a sealant film having a thickness of 120 μm. The degree of biomass was 50%.

[Comparative Example 4]
Petroleum-derived LLDPE (Evolue SP2020, Prime Polymer Co., Ltd., density 0.9)
16 kg / m ³ , MFR = 2.3 g / 10 min) 70% by mass, petroleum-derived LDPE (LDPE-F120N manufactured by Ube Maruzen Polyethylene Co., Ltd., density 0.920 kg / m ³ , MFR = 1.2 g)
/ 10 min) 29% by mass and 1% by mass of a slip agent (M-3, manufactured by Nihon Unicar Co., Ltd.) are sufficiently melt-kneaded, and the resulting resin composition is produced by a top blowing air-cooled inflation coextrusion film forming machine. A sealant film having a thickness of 120 μm was produced. The degree of biomass was 0%.

[Evaluation]
(Lamination strength)
Corona treatment was applied to the base material layer laminated surface of the sealant films of Examples 1 to 3 and one surface of the sealant films of Comparative Examples 1 to 2, and the treated surface was biaxially oriented nylon via an adhesive layer. The film (thickness 15 μm) was dry laminated to produce a laminated film. This laminated film was aged at 40 ° C. for 3 days, and the laminate strength after 2 weeks at 23 ° C. was measured as T-type peeling per 15 mm width, tensile speed 50 mm / min. Measured with

(Slippery)
Prepare two sheets of each of the sealant films of Examples 1 to 3 and Comparative Examples 1 and 2, and JIS K7125: 1999 (Friction Coefficient Test Method) for slipperiness of film (heat seal surface) vs. film (heat seal surface). The coefficient of friction was measured in conformity.
The results are shown in Table 1 below.

Although the sealant films of Examples 1 to 3 have a biomass degree as high as 50 to 80%, they have excellent laminate strength and slippage equivalent to the sealant film of Comparative Example 4 (biomass degree 0%). Showed sex.
On the other hand, the sealant films of Comparative Examples 1 and 2 were slightly inferior in laminate strength. Moreover, the sealant film of Comparative Example 3 was further inferior in laminate strength.

(Appearance of pouch)
About the sealant film of Examples 1-3 and Comparative Examples 1-4, it carried out similarly to said laminate strength measurement, produced the laminated | multilayer film, and obtained the packaging material for the trunk material of a pouch.

  Separately from this, the first resin composition of Example 3 was used to form a single-layer sealant film (thickness 130 μm) by using a top-blown air-cooled inflation coextrusion film-forming machine. About the obtained sealant film, it carried out similarly to said lamination strength measurement, produced the laminated | multilayer film, and obtained the packaging material for the bottom material of a pouch.

  Standing pouches having outer dimensions: height 230 mm × width 130 mm, bottom folding portion height 40 mm, and seal width 5 mm were manufactured using the obtained packaging materials for the trunk and the bottom. The bottom was heat-sealed with a boat-bottom seal pattern.

Ten pouches prepared as described above were prepared for each example / comparative example, and each pouch was filled with 380 cc of water, heat sealed and sealed. These pouches are then stored at 3 ° C. for 3 days, after a height of 1.2 m, level with the floor (so that the torso hits the floor).
And was dropped 5 times perpendicularly to the floor (so that the bottom hits the floor), and the change in the appearance of the pouch was visually observed.
The results are shown in Table 2 below.

  The pouches using the sealant films of Examples 1 to 3 and Comparative Example 4 maintained a beautiful appearance even after the test. On the other hand, the pouch using the sealant film of Comparative Examples 1 and 2 was subjected to the impact of dropping, and delamination was observed in a part of the film, and the appearance was inferior. Moreover, the pouch using the sealant film of Comparative Example 3 had a larger area than Comparative Examples 1 and 2, showed delamination of the film, and was inferior in appearance.

A. Base material layer lamination surface B. Heat sealing surface 1, 3. 1. Layer composed of petroleum-derived polyethylene resin 3. Layer made of plant-derived polyethylene resin Base material layer

Claims (6)

A sealant film used by being laminated on a base material layer,
A multilayer laminated film comprising one or more layers made of petroleum-derived polyethylene resin and one or more layers made of plant-derived polyethylene resin;
The outermost layer forming the laminated surface with the base material layer is a layer made of petroleum-derived polyethylene resin, and the petroleum-derived polyethylene resin has a molecular weight of 1000 in the molecular weight distribution diagram obtained by the gel permeation chromatography method. The area ratio of the following low molecular weight regions is 0.5 area% or less with respect to the total peak area,
The petroleum-derived polyethylene resin is a resin composed of petroleum-derived LLDPE or petroleum-derived LDPE,
The said sealant film characterized by the biomass degree of the whole sealant film being 45-80%.   2. The sealant film according to claim 1, wherein the sealant film is a two-layer laminated film composed of one layer composed of a petroleum-derived polyethylene resin and one layer composed of a plant-derived polyethylene resin. It is a three-layer laminated film comprising a layer composed of two layers of petroleum-derived polyethylene resin and a layer composed of one layer of plant-derived polyethylene resin,
In addition to the outermost layer that forms the base material layer laminate surface, the outermost layer that forms the heat seal surface on the opposite side is also a layer made of petroleum-derived polyethylene resin,
The sealant film according to claim 1, wherein the intermediate layer between them is a layer made of a plant-derived polyethylene resin.   A packaging material comprising a base material layer and a layer made of the sealant film according to claim 1.   A packaging bag using the packaging material according to claim 4.   The packaging bag according to claim 5, wherein the packaging bag is a refillable standing pouch.

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