JP2017013485A - Low adsorptivity co-extrusion multilayer sealant film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealant film having sufficient seal strength, having excellent film formation stability and working suitability and further having excellent low adsorptivity.SOLUTION: Provided is a low adsorptivity co-extruded multilayer sealant film 14 comprising the five layers of: an external layer 1; the first polyethylene layer 2; the second polyethylene layer 3; the first low adsorptivity resin layer 4; and the second low adsorptivity resin layer 5 in this order. The external layer 1 and the first polyethylene layer 2 are made of linear low-density polyethylene or high pressure method low density polyethylene, the second polyethylene layer 3 is made of linear low-density polyethylene, the first low adsorptivity resin layer 4 includes a cyclic olefin copolymer and high pressure method low density polyethylene, and the second low adsorptivity resin layer 5 is made of a resin composition including a cyclic olefin polymer, linear low-density polyethylene and high pressure method low density polyethylene.SELECTED DRAWING: Figure 1

Description

The present invention relates to a low adsorptive sealant film in which the amount of adsorption of aromatic components and the like in the contents is reduced, a packaging material using the same, and a packaging container and a packaging bag comprising the same.
More specifically, since the amount of organic compounds adsorbed in the content is reduced, the sealant film is excellent in maintaining the quality of the content and excellent in heat sealability and film forming stability, and packaging using the same. The present invention relates to a material, and a packaging container and a packaging bag made of the material.

In packaging bags for foods, pharmaceuticals, chemical products, etc., the phenomenon in which organic compounds such as aromatic components and medicinal components in the contents are adsorbed or sorbed on the sealant film that is the innermost layer of the packaging container or packaging bag Has become a problem.
On the other hand, in anticipation of the amount adsorbed or sorbed on the sealant film, measures are taken to contain an excessive amount of aroma components and medicinal components in the contents. However, when these components are expensive, an excessive amount is not preferable because it increases the cost.
In addition, for example, in the packaging of luxury goods, the fragrance component is adsorbed or sorbed on the sealant film, so that the fragrance at the time of filling cannot be maintained until the product reaches the consumer or until the expiration date. There is.

  Furthermore, the sealant film used for packaging foods and beverages has strength, sterilization resistance and heat resistance for protecting the contents from distribution, storage or sterilization treatment, transparency for confirming the contents, Various functions such as heat sealability for sealing the container are required, and for satisfying these requirements, for example, an unstretched polyolefin-based resin film is used. This sealant film is as described above. In addition, it is known that organic compound components in the contents are easily adsorbed or sorbed.

In order to solve these problems, sealant films made of a polyester resin, amorphous polyethylene terephthalate (PET), polyacrylonitrile resin, or the like have been proposed (Patent Documents 1 and 2).
However, since the polyester-based resin has poor heat-sealing properties and is likely to cause a sealing failure at the time of bag making, a packaging bag having a sealant layer made of such a resin has drawbacks such as leakage of contents.
In addition, amorphous PET cannot obtain a sufficient sealing strength and cannot be used for packaging heavy objects. On the other hand, the polyacrylonitrile resin is expensive and it is difficult to obtain materials, and further, it is difficult to form a film for forming a film.

JP-A-5-162737 JP-A-8-143453

  The present invention solves the above-mentioned problems, has sufficient sealing strength, is excellent in film forming stability and processability, and maintains various functions required for conventional sealant films. It is an object of the present invention to provide a sealant film that hardly adsorbs an organic compound, that is, excellent in low adsorptivity, a packaging material using the same, and a packaging container and a packaging bag comprising the same.

  As a result of various studies, the inventor has found that the outer layer, the first polyethylene layer, the second polyethylene layer, the first low-adsorption resin layer, and the second low-adsorption resin layer in contact with the contents are five layers. In this order, the outer layer and the first polyethylene layer are each composed of linear low density polyethylene (LLDPE) or high pressure method low density polyethylene (LDPE). The second polyethylene layer is a layer made of LLDPE, and the first low-adsorption resin layer comprises 80 to 97% by mass of cyclic olefin copolymer (COC) and 3 to 20% by mass of LDPE. The second low-adsorption resin layer is a resin composition containing 15 to 65 mass% COC, 30 to 80 mass% LLDPE, and 3 to 10 mass% LDPE. The low-adsorbing coextruded multilayer sealant, wherein the COC is a copolymer obtained by copolymerizing 55 to 85% by mass of norbornene monomer and 15 to 45% by mass of α-olefin. It has been found that a film, a packaging material using the film, and a packaging container and a packaging bag comprising the film achieve the above-described object.

The present invention is characterized by the following points.
(1) Low adsorptivity having five layers in this order: outer layer, first polyethylene layer, second polyethylene layer, first low adsorptive resin layer, and second low adsorptive resin layer in contact with the contents A coextruded multilayer sealant film, wherein the outer layer and the first polyethylene layer are each a layer made of LLDPE or LDPE, and the second polyethylene layer is a layer made of LLDPE, and the first low adsorption layer The adhesive resin layer is a layer made of a resin composition containing 80 to 97% by mass of COC and 3 to 20% by mass of LDPE, and the second low adsorptive resin layer is 15 to 65% by mass. COC, a layer comprising a resin composition comprising 30 to 80% by mass LLDPE and 3 to 10% by mass LDPE, wherein the COC is 55 to 85% by mass of norbornene monomer and 15 to 45% by mass. with α-olefin A copolymer obtained by copolymerizing, the low adsorptive coextruded multilayer sealant film.
(2) The total thickness of the first and second low-adsorption resin layers is in the range of 20 to 50% of the total thickness of the low-adsorption coextruded multilayer sealant film, as described in (1) above. Low adsorptive coextrusion multilayer sealant film.
(3) The low adsorptive coextruded multilayer sealant film according to (1) or (2), wherein the total thickness is 20 to 150 μm.
(4) The low adsorptive coextrusion multilayer sealant film according to any one of (1) to (3), wherein the second low adsorptive resin layer contains an antiblocking agent.
(5) The low adsorptive coextrusion multilayer sealant film according to any one of (1) to (4), wherein the COC has a glass transition temperature of 100 ° C. or lower.
(6) A packaging material obtained by laminating a substrate on the outer layer side surface of the low adsorptive coextrusion multilayer sealant film according to any one of (1) to (5).
(7) A liquid paper container obtained by boxing the packaging material according to (6) so that the second low-adsorbent resin layer becomes a contact content layer.
(8) A packaging bag obtained by overlapping the packaging material according to (6) above so that the second low adsorptive resin layer becomes a contact content layer and making a bag.

In general, it is known that a cyclic olefin-based resin such as COC has a high intermolecular force during melt film formation and causes aggregation between polymers. As a result, fish eyes are formed due to the aggregation of the resin throughout the film, and it is difficult to obtain a uniform film surface.
These tendencies become more prominent during film formation by the inflation method, and the COC film obtained by the method generates innumerable fish eyes on the entire surface. Further, the COC film has high rigidity and lacks processability as a film.
However, by blending LDPE with COC, among other polyethylenes, according to the present invention, gelation of COC can be prevented and fish eye formation can be suppressed.

In addition, the five-layer coextrusion sealant film having the layer constitution of the present invention using this blend of COC and LDPE and a blend obtained by further adding LLDPE does not adsorb the components in the contents and is excellent. In addition to exhibiting low adsorptivity, it has excellent heat sealing properties, high sealing strength and low temperature sealing properties.
Furthermore, the sealant film of the present invention can be easily formed, can form a beautiful layer having a uniform thickness and good transparency. In addition, the generation of fish eyes can be suppressed during high-speed film formation by the inflation method.

  In such a sealant film of the present invention, the layer made of the resin composition containing COC and LDPE forms a dense surface structure with a close intermolecular distance based on the high intermolecular force of COC. The second polyethylene layer made of LLDPE exhibits high interlayer adhesion with the layer made of the resin composition and imparts good film forming stability.

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

The above-described present invention will be described in more detail below.
<1> Layer structure of sealant film of the present invention and packaging material using the same FIG. 1 is a schematic cross-sectional view showing the sealant film of the present invention.
FIG. 2 is a schematic cross-sectional view showing an example of the layer structure of a packaging material using the sealant film of the present invention.

As shown in FIG. 1, the sealant film of the present invention comprises an outer layer (1), a first polyethylene layer (2), a second polyethylene layer (3), a first low adsorptive resin layer (4), And it is a coextrusion multilayer sealant film (14) which consists of five layers which provided the 2nd low adsorptivity resin layer (5) which touches the contents in this order.
Here, the outer layer (1) and the first polyethylene layer (2) are layers made of LLDPE or LDPE, and the second polyethylene layer (3) is a layer made of LLDPE, and the first low adsorptive resin. The layer (4) is a layer made of a resin composition in which COC and LDPE are blended, and the second low adsorptive resin layer (5) is a layer made of a resin composition in which COC, LDPE and LLDPE are blended. It is.

The resin composition for forming the second low adsorptive resin layer (5) may contain a small amount of an antiblocking agent, for example, less than 5% by mass, in order to improve the slippage of the film surface and improve the processability. .
Arbitrary base materials, such as a base material layer (10) and / or a barrier layer (12), are provided on the outer layer (1) side surface of the sealant film (14) of the present invention via an adhesive layer (11, 13). By laminating, the packaging material of the present invention is obtained. The lamination means may be any method such as sandwich lamination or dry lamination.
Hereinafter, the resin names used in the present invention are those commonly used in the industry. In the present invention, the density conforms to JIS K7112.

<2> Sealant film In the five-layer coextrusion multilayer sealant film of the present invention, the total thickness and the thickness of each layer are as follows:
Although it can be set as appropriate according to the application of the packaging material to be applied, in order to obtain the sealing strength necessary for box making or bag making, and from the viewpoint of stable film formation, low adsorptivity, and product cost, The total thickness is 20 to 150 μm, more preferably 30 to 60 μm. If it is thicker than this, the rigidity of the sealant film becomes high and molding failure occurs, and if it is thinner than this, sufficient adhesive strength cannot be obtained, and sealing performance is reduced. Can be damaged.

The total thickness of the first and second low-adsorbent resin layers is 20 to 50% of the total thickness of the sealant film, and more preferably 30 to 40%. When the total of the low adsorptive resin layers is thinner than 20% of the total thickness, it is difficult to obtain sufficient low adsorptivity. Conversely, if it is thicker than 50%, the low adsorptivity increases, but there is a possibility that the flexibility of the film and the laminate strength with the substrate or the like cannot be ensured.
The first low adsorptive resin layer is preferably 3 to 7 μm, for example. Moreover, it is preferable that a 2nd low adsorptivity resin layer is at least 5 micrometers or more, for example, 5-15 micrometers.
A second low-adsorption resin layer containing LLDPE in addition to COC and LDPE is located in the innermost layer, and adjacent to this, the first low-adsorption resin layer containing COC at a high concentration has a thin layer thickness. The sealant film of the present invention can have excellent low adsorptivity, flexibility, film forming stability, and heat sealability.

(I) Outer layer In the sealant film of the present invention, the outer layer is a layer that is located on the surface of the sealant film and forms a bonding surface with the substrate.
As the resin constituting the outer layer, LLDPE or LDPE is used. Thereby, when bonding with a base material by sandwich lamination etc., high interlayer adhesive strength is obtained. Here, the toughness of the film can be increased by using LLDPE.
On the other hand, by using LDPE, the film-forming property can be improved, and when applied to the sealant of a paper container, the gap generated in the step can be filled to improve the sealing performance of the container. If necessary, conventional additives such as antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, flame retardants, and colorants may be added.
The thickness of the outer layer is preferably 5 to 20 μm, and if it is too thin, sufficient interlayer adhesion strength with the substrate cannot be ensured.

Hereinafter, in the present invention, LLDPE is a linear polyethylene having a density of 0.900 to 0.940 g / cm ³ , and uses a single site catalyst such as a metallocene catalyst or a multisite catalyst such as a Ziegler-Natta catalyst. And a copolymer obtained by copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms at low temperature and low pressure.
Specific examples of the α-olefin having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-nonene and 1-decene. , 1-dodecene and the like. Examples of the copolymerization method include ethylene and α-olefin polymerization methods such as a low pressure method, a slurry method, a solution method, and a gas phase method.

The LLDPE of the present invention has 3 to 25 short chain branches per 1000 carbon atoms as short chain branches, but is not distinguished from LDPE in that it does not have long chain branches exceeding about 20 carbon atoms.
Usually, in LLDPE, the structural unit derived from ethylene is about 99.9 to 90 mol%, and the structural unit derived from α-olefin is about 0.1 to 10 mol%.
Suitable LLDPE for use in the present invention includes “Ultzex ^(R) ” manufactured by Prime Polymer Co., Ltd.
On the other hand, LDPE is an ethylene homopolymer produced by a high pressure method and having a density of 0.910 or more and less than 0.930. Suitable LDPE for use in the present invention, polyethylene, Ltd. in Japan "Novatec ^(R)", and the like.

(Ii) First polyethylene layer The first polyethylene layer is located between the outer layer and the second polyethylene layer, and adjusts the balance of the thickness and layer ratio of the film while ensuring the interlayer adhesive strength. It is a layer that improves film formation stability. Since the resin constituting the first polyethylene layer and the layer thickness can be adjusted according to the use of the sealant, the sealant film of the present invention has high versatility.
In order to fulfill these functions, LDPE or LLDPE can be suitably used as the resin constituting the first polyethylene layer. Here, the toughness of the film can be increased by using LLDPE.
On the other hand, by using LDPE, the film-forming property can be improved, and when applied to the sealant of a paper container, the gap generated in the step can be filled to improve the sealing performance of the container. If necessary, conventional additives such as antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, flame retardants, and colorants may be added.
The thickness of the first polyethylene layer is preferably 5 to 20 μm. If the first polyethylene layer is too thin or too thick, the film-forming stability deteriorates, which is not preferable.

(Iii) Second polyethylene layer The second polyethylene layer is located between the first polyethylene layer and the first low adsorptive resin layer, and the film thickness is reduced while ensuring the interlayer adhesive strength. While adjusting, it is a layer which improves film forming stability.
In order to perform these functions, the second polyethylene layer consists of LLDPE. If necessary, conventional additives such as antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, flame retardants, and colorants may be added.
The thickness of the second polyethylene layer is preferably 5 to 20 μm, more preferably 7 to 15 μm. If the second polyethylene layer is too thin, the interlayer strength becomes weak, which is not preferable. On the other hand, if it is too thick, the film-forming stability deteriorates, which is not preferable.

(Iv) First low adsorptive resin layer The first low adsorptive resin layer is located between the second polyethylene layer made of LLDPE and the second low adsorptive resin layer serving as the innermost layer, This is the first layer for preventing the penetration, adsorption and sorption of organic compounds in the contents, and consists of a resin composition containing COC and LDPE.
If necessary, conventional additives such as antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, flame retardants, and colorants may be added.
In the present invention, COC is a copolymer obtained by copolymerizing a norbornene monomer and an α-olefin.

The norbornene monomer has a bicyclo [2.2.1] hept-2-ene (norbornene) skeleton, specifically, bicyclo [2.2.1] hept-2-ene and its derivatives, tricyclo [4.3.0.1 ^2.5] -3- decene and derivatives thereof, tricyclo [4.4.0.1 ^2.5] -3- undecene and derivatives thereof, tetracyclo [4.4.0.1 ^2.5 .1 ^7.10] -3-dodecene and derivatives thereof, pentacyclo ^{[6.5.1.1 3.6 .0 2.7 .0 9.13]} -4- pentadecene and its derivatives, pentacyclo [7.4.0.1 ^2.5 .1 ^9.12 .0 ^8.13] -3-pentadecene and its derivatives, pentacyclo ^{[6.5.1.1 3.6 .0 2.7 .0 9.13]} -4,10- penta decadiene and its derivatives, pentacyclo [8.4.0.1 ^2.5 .1 ^9.12 .0 ^8.13] -3-hexadecene and derivatives thereof, and the like, et al. However, it is not limited to these.
These cyclic olefins may have a polar group such as an ester group, a carboxyl group, and a carboxylic anhydride group as a substituent.

As the α-olefin copolymerized with the norbornene monomer, ethylene and an α-olefin having 3 to 20 carbon atoms can be used. Specifically, ethylene, propylene, 1
-Butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene and the like can be mentioned, and ethylene is preferable.

In the present invention, COC is produced by randomly using 15 to 45% by mass of an α-olefin and 55 to 85% by mass of a norbornene monomer using a single site catalyst such as a metallocene catalyst or a multisite catalyst. This is done by polymerizing.
A copolymer copolymerized at this ratio can exhibit the effects of the present invention by forming a film according to the present invention. In addition, it has low water absorption, has a barrier property against water vapor, has low birefringence, and has excellent optical properties, and therefore has excellent transparency. Furthermore, it exhibits good heat resistance and dimensional stability.

Preferably, it is preferable to use COC having a glass transition temperature of 100 ° C. or lower, more preferably 85 ° C. or lower. By forming a film using COC having a low glass transition temperature according to the present invention, generation of wrinkles can be prevented, and film forming stability is improved.
Examples of the COC suitably used in the present invention include “TOPAS ^(R) ” manufactured by Polyplastics Co., Ltd.
By blending LDPE with the above-mentioned COC, it is possible to prevent the generation of fish eyes due to aggregation of COCs during film formation particularly preferably as compared with the case of blending other polyethylene.
As a blend amount of LDPE, it blends in the resin composition which comprises a low adsorptivity resin layer in the ratio of 3-20 mass%, for example in the ratio of 3-10 mass%. If the ratio of LDPE is too large, the low adsorptivity may be impaired. On the other hand, when the ratio of LDPE is too small, the film-forming stability is impaired and fish eyes are likely to be generated.

In a preferred embodiment of the present invention, the LDPE has a melt flow rate (MFR) at 190 ° C. of 10 to 80 g / 10 minutes, particularly 15 g / 10 minutes or more, more preferably 20 g / 10 minutes or more, for example 25 to 25 g. The thing of 80 g / 10min can be used especially suitably.
LDPE having an MFR in this range can be blended homogeneously with COC to further improve film formation stability. In the present invention, the melt flow rate is measured according to JIS-K-7210 (190 ° C., load 2.16 kg).

  The thickness of the first low adsorptive resin layer is preferably 3 to 7 μm. If the first low adsorptive resin layer is too thin, the penetration of the organic compound in the contents cannot be sufficiently prevented. On the other hand, if this layer is too thick, the flexibility is impaired and the handleability and processability as a film are poor.

(V) Second low adsorptive resin layer The second low adsorptive resin layer is located on the surface of the sealant film and is the innermost layer that comes into contact with the contents during bag making or box making. This is a second layer for preventing penetration, adsorption and sorption of organic compounds in the object.
The second low adsorptive resin layer is made of a resin composition containing COC, LLDPE, and LDPE. In addition to a small amount of LDPE that prevents fish eyes, blending LLDPE further provides excellent low temperature sealability and desired seal strength. As the COC, LLDPE, and LDPE, the resins listed in the outer layer and the first low-adsorption resin layer can be preferably used.

The ratio of each resin in the resin composition can be appropriately determined by those skilled in the art depending on the desired seal strength and low adsorptivity, but in one embodiment, the COC is 15 to 65% by mass, More preferably, it is 40-50 mass%.
Moreover, LLDPE is 30-80 mass%, More preferably, it is 40-50 mass%. Furthermore, LDPE is 3-10 mass%, More preferably, it is 5-10 mass%.
If the proportion of COC is too large, the film-forming stability is impaired, the heat sealability is impaired, and the desired seal strength and low-temperature sealability may not be obtained. When there is too much LLDPE, low adsorptivity will be impaired, conversely, when too little, heat sealability will be impaired.
Moreover, when there is too much LDPE, low adsorptivity and heat-sealability will be impaired, and conversely, when it is too little, it will become easy to generate fish eyes.

If necessary, conventional additives such as antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, flame retardants, and colorants may be added to the resin composition. In particular, an inorganic filler may be included as an antiblocking agent in order to improve the slipperiness during processing.
Since the second low adsorptive resin layer serving as the innermost layer contains an anti-blocking agent in advance, it can also be suitably applied as a liquid packaging bag in which a lubricant cannot be sprayed later.
The added amount of the inorganic filler is 0.5 to 5% by mass, desirably about 1 to 3% by mass with respect to the second low-adsorbent resin layer. When the added amount of the inorganic filler is smaller than this, the filler is hardly exposed on the surface of the sealant film, and the effect of improving the slip failure is small.
Moreover, since the filler will be saturated in the sealant film surface when it exceeds 5 mass%, even if it adds more filler, the effect corresponding to this cost is not acquired.
Further, the transparency is remarkably lowered and the visibility is deteriorated. The inorganic filler can be homogeneously dispersed in the resin composition by blending as a master batch.
Suitable inorganic fillers which can be _{used, SiO 2, AL 2 O 3} , TiO 2, ZnO, Fe 2 O 3, SnO 2, CeO 2, NiO, PbO, S 2 Cl 2, ZnCl 2, FeCl 2, CaCO ₃ , B ₂ O _{3 and the} like, and a filler having an average particle diameter of 2 to 15 μm can be used. Preferably, a silicon oxide SiO ₂ filler is used.
When the average particle size of the inorganic filler is less than 2 μm, there is no effect in improving the slipperiness, and when the average particle size exceeds 15 μm, the container surface is rubbed by the inorganic filler protruding on the surface of the film forming film. And hurt.
In addition, in this invention, an average particle diameter means the particle size of the particle which exists most by particle size distribution measurement. The particle size distribution can be measured by a Coulter counter method.

  The thickness of the second low adsorptive resin layer is preferably 5 to 15 μm, more preferably 5 to 10 μm. If the second low adsorptive resin layer is too thin, sufficient sealing strength cannot be obtained, and the sealing performance is impaired. On the other hand, if it is too thick, the amount of adsorption of the organic compound in the contents increases and the low adsorptivity is impaired.

(Vi) Manufacturing method of sealant film In this invention, a sealant film is formed into a film by the co-extrusion method using resin and resin composition which comprise each layer. By forming a film by the coextrusion method, high interlayer adhesion and film forming stability can be obtained, low adsorptivity can be improved, and a beautiful film can be obtained. In particular, the generation of fish eyes can be suppressed.
In particular, the sealant film can also be formed by a coextrusion inflation method. By forming a film by the coextrusion inflation method, film formation can be performed at a low temperature, and troubles caused by resin odor due to heating are reduced.

<3> Packaging material A low adsorptive packaging material is obtained by laminating the sealant film of the present invention so that the inner layer is the innermost layer with the surface on the outer layer side facing an arbitrary substrate.
As a base material used here, arbitrary films, such as paper, a base film, or the barrier film which provided the gas barrier layer on the base film, can be used.
As the paper, any paper having various formability, bending resistance, rigidity, waist, strength and the like can be used depending on the application of the paper container to be applied. For example, it is a main strength material, and various types of paper such as strong sized bleached or unbleached paper, or pure white roll paper, kraft paper, paperboard, processed paper, and milk base paper can be used.
As a base film, a biaxially stretched film of polyester such as PET and polyethylene naphthalate, a biaxially stretched film of polyamide such as nylon 6, nylon 66, MXD6 (polymetaxylylene adipamide), a biaxially stretched polypropylene film, etc. The plastic film can be suitably used.
These may be used singly or may be used by combining a plurality.

  The gas barrier layer may be a vapor deposition layer of an inorganic oxide such as silica, alumina, zinc oxide, magnesium oxide, indium tin oxide, or a metal such as aluminum. Or ethylene / vinyl acetate copolymer saponified product (EVOH), polyvinylidene chloride (PVDC), nylon MXD6, etc., metal film such as aluminum foil, or PVDC, polyvinyl alcohol (PVA), polyacrylic acid A gas barrier film such as a biaxially stretched nylon film (ON film), a biaxially stretched PET film, or a biaxially stretched polypropylene film (OPP film) provided with a coating layer such as (PAA) is formed on a substrate via an adhesive layer. It may be laminated on a film.

As a method for laminating the gas barrier layer, when the gas barrier layer is a vapor deposition layer, the gas barrier layer is laminated on the base film by an arbitrary vapor deposition method such as a chemical vapor deposition method and a physical vapor deposition method. When a gas barrier layer is a gas barrier film, it laminates | stacks on a base film through an adhesive bond layer.
Lamination of the sealant film of the present invention and the substrate can be performed by a conventional means such as a dry laminating method or a sandwich laminating method via an arbitrary adhesive or adhesive resin. As needed, you may perform various surface pretreatments, such as providing an anchor-coat agent layer in the bonding surface of a base material, before laminating | stacking.
In a particularly preferred embodiment of the present invention, by laminating a sealant film and a substrate by sandwich lamination using molten polyethylene or ethylene / methacrylic acid copolymer as an adhesive layer, high interlayer adhesive strength can be obtained and delamination can be prevented. it can.

<4> Packaging Container The packaging material of the present invention can be suitably used as a packaging bag or packaging container, particularly for forming a packaging bag or packaging container that requires the quality retention of the contents.
Moreover, since the sealant film of the present invention exhibits a low sealing property and a high sealing strength, it can also be used as a paper container, particularly a liquid paper container.
The production of the packaging bag from the packaging material of the present invention can be made by folding the packaging material described above in two or by preparing two packaging materials, with the surfaces of the sealant films facing each other, and further surrounding the peripheral edge portion. For example, side seal type, two-side seal type, three-side seal type, four-side seal type, envelope-attached seal type, joint-attached seal type (pillow seal type), pleated seal type, flat bottom seal type, square bottom seal type, gusset It can be manufactured as a packaging bag of various forms by heat-sealing with a heat-sealing form such as a mold.
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.

Or manufacture of the paper container from the packaging material of this invention is normally performed as follows. That is, after printing as necessary on the surface of the packaging material of the present invention, it is punched out, and the end face is skived and hemmed so that the contents do not come into contact with the end face. Heat seal by heating, flame heating, etc. to make a paper container.
The shape of the paper container may be determined as appropriate according to the use and purpose, and examples thereof include a gable top type, a brick type, a flat type, and a cylindrical paper such as a rectangular container or a round shape. A can etc. are mentioned. For example, a polyethylene cap, a pull tab-type opening mechanism, and the like may be appropriately provided at the spout of the paper container.

The contents filled in the packaging bag or packaging container are not particularly limited, and even if it is solid or gelled, it can be a liquid, for example, various drinks such as liquor, juice such as fruit juice, mineral water, Liquid seasonings such as soy sauce, sauces and soups, or various liquid foods and drinks such as curry, stew and soup, edible oils, machine oils, adhesives, adhesives, and other chemicals, cosmetics, pharmaceuticals and other general goods In addition, chemical products such as shampoos, rinses and detergents may be used.
The packaging bag or packaging container made of the packaging material of the present invention can maintain the quality and flavor of the contents over a long period of time, and exhibits high sealing performance, so it is particularly suitable for use as a packaging container for alcoholic beverages. Can do.
Next, the present invention will be specifically described with reference to examples.

[Example 1]
(1) As a resin composition constituting the first low adsorptive resin layer, COC (TOPAS ^(R) 8007F-600 manufactured by Polyplastics Co., Ltd., content of norbornene-derived repeating unit 65% by mass, glass transition temperature 78 ° C.) 95% by mass and LDPE (Asahi Kasei Chemicals Corporation Suntec M6545, MFR 45.0 g / 10 min, density 0.915 g / cm ³ ) 5% by mass are sufficiently kneaded to prepare a resin composition. did.
(2) As a resin composition constituting the second low adsorptive resin layer, COC (TOPAS ^(R) 8007F-600) 40% by mass, LLDPE (Ube Maruzen Polyethylene Co., Ltd. Umerit ^(R) 0520F, MFR 2 g / 10 minutes, density 0.904 g / cm ³ ) 45% by mass, LDPE (Suntech M6525) 5% by mass, and anti-blocking agent master batch (manufactured by Sumitomo Chemical Co., Ltd., EMB-21, MFR 4 g / 10 min, synthetic zeolite) Contained) 10% by mass was sufficiently kneaded to prepare a resin composition.
(3) as the outer layer and the first resin constituting the polyethylene layer was prepared LDPE (Nippon Polyethylene Co., Ltd. NOVATEC ^(R) LC522, ^MFR4.0g / 10 min, density 0.923 g / cm ^3). Further, as a resin constituting the second polyethylene layer, LLDPE (Ultimex ^(R) 1520L, Prime Polymer Co., Ltd., MFR 2.3 g / 10 min, density 0.914 g / cm ³ ) was prepared.
(4) Using the resin and resin composition prepared in the above (1) to (3), the outer layer 10 μm / the first polyethylene layer 7.5 μm / the first by the five-layer coextrusion film forming method using the inflation method. A low-adsorbent sealant film (thickness 40 μm) of the present invention having a layer configuration of two polyethylene layers 10 μm / first low-adsorption resin layer 5 μm / second low-adsorption resin layer 7.5 μm was produced. In the description of the laminate in the present specification, “/” indicates that the left and right layers are laminated and integrated.
The obtained low adsorptive sealant film had a beautiful film surface without fish eyes.

[Example 2]
A low adsorptive sealant film was produced in the same manner as in Example 1 except that the COC of the second low adsorptive resin layer was 15% by mass, LLDPE was 50% by mass, and the antiblocking agent master batch was 30% by mass.

[Example 3]
A paperboard having a basis weight of 365 g / m ² is prepared as a base material, an anchor coating agent is applied to one surface thereof, and a transparent vapor-deposited film (by a sandwich lamination method through an ethylene / methacrylic acid copolymer (EMAA, thickness 25 μm)) ( A vapor-deposited surface of VMPET, a transparent vapor-deposited film in which aluminum oxide was vapor-deposited on one side of a biaxially stretched PET film having a thickness of 12 μm, was bonded.
The surface on the outer layer side of the low adsorptive sealant film produced in Example 1 is bonded to the VMPET side surface of the obtained laminated film by a sandwich lamination method using an ethylene / methacrylic acid copolymer (EMAA, thickness 30 μm). It was.
On the other hand, an anchor coating agent is applied to the other side of the paperboard, a polyethylene resin (thickness: 25 μm) is laminated as a surface protective layer by an extrusion coating method, the surface is corona-treated, and a printing layer is provided. The inventive packaging material was produced.
The layer structure of the obtained packaging material was printing layer / polyethylene resin layer 25 μm / paper substrate layer / EMAA layer 25 μm / VMPET 12 μm / EMAA layer 30 μm / low adsorptive sealant film 40 μm.

[Example 4]
A packaging material was produced in the same manner as in Example 3 except that the low-adsorption sealant film produced in Example 2 was used.
Using the packaging material produced above, it was boxed so that the sealant film was inside, and a paper container having a capacity of 200 mL was prepared. This was filled with 200 mL of water at 85 to 90 ° C. while hot, allowed to cool to room temperature, and left for 3 days. The paper container showed sufficient sealability and no leakage of contents occurred.

[Comparative Example 1]
A packaging material was produced in the same manner as in Example 3 except that an LLDPE film (thickness: 40 μm) was used instead of the low adsorptive sealant film of Example 1.

[Evaluation methods and results]
(Sensory test)
A sake paper container was prepared using the packaging materials of Example 3, Example 4 and Comparative Example 1, and the sample was filled with sake using a filling machine to obtain a sample for evaluation.
After storage for 7 days, the container was opened, and a sensory evaluation was conducted by three persons in charge of taste affiliation belonging to the sake maker.
The average value is obtained by unpacking two samples for each packaging material in a five-step evaluation with 0 points when there is no change in the smell of sake before filling and 5 points when the smell of sake changes considerably. It was. The results are shown in Table 1.

The sake stored in the packaging containers of Example 3 and Example 4 almost completely retained the flavor before filling. On the other hand, the sake preserved in the packaging container of Comparative Example 1 lost the flavor component of sake, and the odor before filling changed considerably.

(Gas chromatograph mass spectrometry)
In order to confirm that the flavor change produced in the sensory test was not due to elution of the various components of the packaging material into the contents, gas chromatograph mass spectrometry was performed.
That is, a paper container having a capacity of 200 mL was prepared using the packaging materials of Example 3, Example 4, and Comparative Example 1, and 200 mL of water was hot-filled at 85 to 90 ° C. and allowed to cool to room temperature. The samples were left for a day and used as evaluation samples.
About 200 mL of water recovered from the container, it was concentrated by liquid-liquid extraction using an organic solvent and lyophilization, and the elution amounts of chloroform and methanol from the packaging container were measured with a gas chromatograph mass spectrometer. The elution amount measured in Comparative Example 1 was set to 1, and the elution amounts in Example 3 and Example 4 were relatively evaluated. The results are shown in Table 2.

  In Example 3, Example 4 and Comparative Example 1, no significant difference was observed in the amount of elution. Moreover, from any sample, the elution to each solution extracted with chloroform and methanol from the packaging material was hardly detected.

1. Outer layer 2. First polyethylene layer3. Second polyethylene layer4. 4. First low adsorptive resin layer Second low adsorptive resin layer 10. Base material layer 11. Adhesive layer 12. Barrier layer 13. Adhesive layer 14. Sealant film

Claims (8)

Low adsorbent coextrusion multilayer having 5 layers in this order: outer layer, first polyethylene layer, second polyethylene layer, first low adsorbent resin layer, and second low adsorbent resin layer in contact with the contents A sealant film,
Each of the outer layer and the first polyethylene layer is a layer made of linear low density polyethylene or high pressure method low density polyethylene,
The second polyethylene layer is a layer made of linear low density polyethylene,
The first low adsorptive resin layer is a layer made of a resin composition comprising 80 to 97% by mass of a cyclic olefin copolymer and 3 to 20% by mass of a high pressure method low density polyethylene,
The second low adsorptive resin layer comprises a resin composition comprising 15 to 65% by mass of cyclic olefin copolymer, 30 to 80% by mass of linear low density polyethylene and 3 to 10% by mass of high pressure method low density polyethylene. A layer consisting of
The low adsorptive coextruded multilayer sealant film, wherein the cyclic olefin copolymer is a copolymer obtained by copolymerizing 55 to 85% by mass of a norbornene monomer and 15 to 45% by mass of an α-olefin.   The low adsorptivity according to claim 1, wherein the total thickness of the first and second low adsorptive resin layers is in the range of 20 to 50% of the total thickness of the low adsorptivity coextruded multilayer sealant film. Coextruded multilayer sealant film.   The low adsorptive coextrusion multilayer sealant film according to claim 1 or 2, wherein the total thickness is 20 to 150 µm.   The low adsorption coextrusion multilayer sealant film according to any one of claims 1 to 3, wherein the second low adsorption resin layer contains an antiblocking agent.   The low adsorptive coextrusion multilayer sealant film according to any one of claims 1 to 4, wherein the cyclic olefin copolymer has a glass transition temperature of 100 ° C or lower.   The packaging material formed by laminating | stacking a base material on the surface of the outer layer side of the low adsorptivity coextrusion multilayer sealant film of any one of Claims 1-5.   A liquid paper container obtained by boxing the packaging material according to claim 6 so that the second low-adsorption resin layer becomes a contact content layer.   A packaging bag obtained by overlapping and packaging the packaging material according to claim 6 so that the second low-adsorption resin layer becomes a contact content layer.

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