JP7035423B2 - Laminates for packaging liquid contents, packaging materials for liquid contents, packaging for liquid contents - Google Patents

Description

In the present invention, the elution organic substance originally contained in the packaging material and the odorous component generated from the packaging material during the sterilization / sterilization process are transferred to the liquid content in the packaging material and transformed into the content. A laminated body for packaging liquid contents, which has excellent odor resistance and taste changeability, and a packaging material for liquid contents and a liquid content, which are produced by using the laminated body. Regarding the packaging.

As a packaging material, a packaging material containing an odor adsorbent that adsorbs an odor has been proposed (Patent Document 1). In such a packaging material, an odor adsorbent such as synthetic zeolite or activated carbon is kneaded into the resin material.
However, such a packaging material has a problem that it adsorbs not only odor but also moisture in the atmosphere and desorbs the odor once adsorbed, so that a sufficient odor adsorption effect can be obtained. Not.
A packaging material containing an odor adsorbent obtained by supporting a chemical adsorbent on an inorganic porous body is also known (Patent Document 2), but the main adsorbed object adsorbs an odor component having a specific functional group. However, in the situation where the resin material is not selected, the amount of organic substances having no functional group cannot be suppressed, and the odorous component cannot be sufficiently adsorbed.

Japanese Patent No. 2538487 Japanese Unexamined Patent Publication No. 2014-233408

The present invention solves the above-mentioned problems, is excellent in manufacturing suitability, and sterilizes and sterilizes elution organic substances originally contained in the packaging material by UV irradiation, hot pack, boil, γ-ray irradiation, EB irradiation, etc. During the treatment, it exerts a high adsorption effect on the odor generated by the decomposition of the resin constituting the package and deodorizes it.
Moreover, since it is possible to efficiently adsorb the odor without desorbing the odor once adsorbed, the odor adsorbing ability does not decrease, a high adsorption effect is exhibited for a long period of time, and resistance to liquid contents is exhibited. Laminates for packaging liquid contents with excellent odor changeability, film-forming property, seal strength, piercing strength, and pinhole resistance, and packaging materials and liquids for liquid contents produced using the laminates. The purpose is to provide a package for contents.

As a result of various studies, the present inventors have obtained the results of various studies.
A laminate for packaging liquid contents having a base material layer and a sealant layer, wherein the sealant layer is a laminate having an odor adsorbent layer containing a specific low-eluting polyethylene and a specific odor adsorbent, and the same. It has been found that a packaging material for liquid contents produced by using a laminate, and further, a packaging material for liquid contents produced by using the packaging material for liquid contents achieves the above-mentioned object.

The present invention is characterized by the following points.
1. 1. A laminate for packaging liquid contents, which has a base material layer and a sealant layer.
The sealant layer has at least an odor adsorption layer and has.
The sealant layer is formed of a resin composition containing low-eluting polyethylene.
The odor adsorbing layer is formed of a resin composition containing a low-eluting polyethylene and an odor adsorbent.
The concentration of the elution TOC contained in the film made of the low-eluting polyethylene is 1.5 ppm or more and 250 ppm or less.
The odor adsorbent is an inorganic porous body carrying a chemical adsorbent.
Laminate for packaging liquid contents.
2. 2. The laminate for packaging liquid contents according to 1 above, wherein the density of the low-eluting polyethylene is 0.90 g / cm ³ or more and 0.94 g / cm ³ or less.
3. 3. The laminate for packaging liquid contents according to 1 or 2 above, wherein the low-eluting polyethylene is LLDPE.
4. The laminate for liquid content packaging according to any one of 1 to 3 above, wherein the low-eluting polyethylene is one or more selected from the group of C4-LLDPE, C6-LLDPE, and C8-LLDPE. body.
5. The number of pinholes generated after 5000 times of gelboflex at 23 ° C. in a 50 μm thick film made of the low-elution polyethylene simple substance is 0, or 1 or more, and 160 or less. A laminate for packaging liquid contents, which is described in any of the above.
6. The odor adsorbent is melt-kneaded in advance with the thermoplastic resin at a mass ratio of 0.5 / 99.5 to 40/60 of the odor adsorbent / thermoplastic resin. The laminate for packaging liquid contents according to any one.
7. The laminate for packaging liquid contents according to 6 above, wherein the melt flow rate of the thermoplastic resin is 0.2 to 10.0 g / 10 minutes.
8. The laminate for packaging liquid contents according to any one of 1 to 7 above, wherein the content of the odor adsorbent is 0.3% by mass or more and 15% by mass or less in the total sealant film.
9. The laminate for packaging liquid contents according to any one of 1 to 8 above, wherein the sealant film has a non-odor adsorbing layer on the front surface and / or the back surface of the odor adsorbing layer.
10. The above-mentioned 1 to 9 above, wherein the chemisorbent has a functional group having reactivity with one or more selected from the group of aldehydes, ketones, and carboxylic acids. Laminate for packaging liquid contents.
11. The laminate for packaging liquid contents according to any one of 1 to 10 above, wherein the chemical adsorbent has an amino group.
12. A packaging material for liquid contents, which is produced by using the laminate for packaging liquid contents according to any one of 1 to 11 above.
13. A package for liquid contents formed from the packaging material for liquid contents according to 12 above.

Since the sealant layer of the laminate for packaging the liquid contents of the present invention has an odor adsorbing layer having a specific constitution and contains a specific low-eluting polyethylene, the packaging material is originally contained. Eluent organic substances and odors are reduced, and odors generated by decomposition of the resin constituting the laminate during sterilization and sterilization of UV irradiation, γ-ray irradiation, EB irradiation, hot packs, boil, etc. for a long period of time It has the effect of efficiently adsorbing.
Due to these effects, when a package for liquid contents is produced using the packaging material for liquid contents of the present invention, the amount of organic substances eluted in the filled liquid contents is reduced and the odor is changed. It can be suppressed.
Therefore, the packaging material for liquid contents of the present invention is suitable as a packaging material for liquid foods, pharmaceuticals, and medical products to be sterilized and sterilized.

It is a schematic sectional drawing which shows an example about the layer structure of the laminated body for packaging a liquid content of this invention. It is a schematic sectional drawing which shows an example about the layer structure of the laminated body for packaging a liquid content of this invention. It is a schematic sectional drawing which shows an example about the layer structure of the laminated body for packaging a liquid content of this invention. It is a figure which shows the adsorption mechanism of an odor adsorbent with respect to an odor substance.

The laminate for packaging the liquid contents of the present invention and the package for the liquid contents produced by using the laminate will be described in more detail below. The present invention will be described with reference to specific examples, but the present invention is not limited thereto.

<Layer structure of laminate for packaging liquid contents of the present invention>
The laminate for packaging liquid contents of the present invention has a base material layer and a sealant layer.
The sealant layer may be at least a sealant layer for packaging liquid contents having an odor adsorption layer, and may be only a layer that functions as a sealant, or may be a layer composed of only the odor adsorption layer 3. It may include a base material layer and an adhesive layer.
Further, the sealant layer 1 may have a multilayer structure of an odor adsorbing layer 3 and a non-odor adsorbing layer 2 containing no odor adsorbent as shown in FIGS. 1 and 2. In the case of FIG. 2, the seal strength and interlayer adhesion may be formed. The strength can be improved.
Further, as shown in FIG. 3, the odor adsorbing layer 3 may have a multi-layer structure such as 3a or 3b having the same or different types of low-eluting polyethylene as a main component and the same or different contents of odor adsorbents. good.

When a package for liquid contents is produced by a packaging material using the laminate for packaging liquid contents of the present invention, even if the innermost layer in contact with the liquid contents of the package is the odor adsorption layer 3. , The non-odor adsorbing layer 2 may be used. When the non-odor adsorbing layer 2 is the innermost layer, the sealing strength of the package can be improved, and when the odor adsorbing layer 3 is the innermost layer, the interlayer adhesion strength in the package can be improved.

Further, although not shown, the odor adsorbing layer 3 may be composed of three or more layers having the same or different types of the main low-eluting polyethylene and the types and contents of the odor adsorbents.

<Low elution polyethylene>
The sealant layer of the laminate of the present invention contains low-eluting polyethylene having a heat-sealing property and a small amount of organic matter eluted.
By reducing the amount of organic matter eluted, it is possible to reduce the concentration of organic matter eluted in the liquid content packed in the package for liquid content using the laminate of the present invention and suppress the change in odor. can.

Here, the concentration of the organic substance in the liquid content is indicated by the concentration of total organic carbon (TOC) in the present invention.
TOC indicates the concentration of the total amount of organic substances (organic carbon bodies) that can be oxidized in water by the concentration of carbon content, and is used as one of the typical water quality indexes. It is standardized by organic carbon (TOC) automatic measuring instrument) and the like.
The concentration of the elution TOC contained in the film made of the low-elution polyethylene is 1.5 ppm or more and 250 ppm or less.
Here, the reason why the concentration of the elution TOC related to the low-eluting polyethylene as a single raw material is measured not in the state of the raw material pellets or the like but in the filmed state is that the low-eluting polyethylene is used for forming a sealant layer or the like. This is because when the film is formed, various thermal histories and the like may be given to increase the elution amount of TOC.

After filling 1 kg of distilled water as filling water in a pouch packaging bag having a thickness of 15 cm × 44 cm × 50 μm made of low-elution polyethylene in the present invention and eluting, the increased concentration of TOC in the filled water is 0. It is preferably 0.01 ppm or more and 1.5 ppm or less, more preferably 0.02 ppm or more and 1.45 ppm or less, and further preferably 0.025 ppm or more and 1.4 ppm or less.
When the increased concentration of TOC in the filling water is larger than 1.5 ppm, it is difficult to suppress the change in the odor of the filled water, and the cost is high to obtain the one smaller than 0.01 ppm. The effect is limited. From the viewpoint of achieving both cost and performance, the above range is preferable.

Here, the increased concentration of TOC in the filling water when the entire amount of the elution component contained in the pouch bag is eluted in 1000 g of the filling water is calculated as follows.
Pouch bag specific density: S [g / cm ³ ]
Pouch bag size: 15 cm x 44 cm x 50 μm thickness Pouch bag weight: W = 15 x 44 x 50 x 10 ^-4 x 2 x S = 6.6 x S [g]
Concentration of elution TOC contained in pouch bag: C [ppm]
Then
Total weight of elution TOC contained in the pouch bag = C × W [g]
Since this elutes in 1000 g of water,
Increased concentration of TOC in filled water = C × W / 1000 = C × 6.6 × S × 10 ^-3 [ppm]
For example, when the specific gravity of the low-eluting polyethylene film constituting the pouch bag is 0.92 and the concentration of the eluted TOC contained is 1.7 ppm,
Increased concentration of TOC in filled water = 1.7 x 6.6 x 0.92 x 10 ^-3 = 0.01 [ppm]
It is calculated as.

As a specific method for determining the increased concentration of TOC, for example, 1000 g of distilled water at 40 ° C to 80 ° C is filled in the above pouch packaging bag, and the temperature is 25 ° C to 50 ° C for several days to 4 weeks. The TOC concentration of the filled water after storage can be measured with a total organic carbon meter or HS-GC, and the TOC concentration of the distilled water can be subtracted as a blank.

In the present invention, a pouch bag (15 cm × 44 cm) package is prepared using a sealant film, and 1000 g of water (distilled water for high performance liquid chromatography, genuine chemicals) at 65 ° C. is filled to fill the package liquid. After preparing the product and storing it at 35 ° C. for 2 weeks, the increased concentration of TOC is determined by measuring the TOC concentration of the filled water with a TOC-L total organic carbon meter manufactured by Shimadzu Corporation as a standard method.
Then, the elution TOC concentration contained in the sealant film is calculated from the obtained TOC increase concentration of the filled water and the mass part of the filled water and the mass part of the sealant film.

Specific examples of the low-eluting polyethylene include low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), linear (linear) low-density polyethylene (LLDPE), and ethylene-vinyl acetate. Low elution of polymers, ethylene-ethyl acrylate copolymers, ethylene-acrylic acid copolymers, ethylene-methacrylic acid copolymers, ethylene-methylmethacrylic acid copolymers, ethylene-propylene copolymers, etc. Things and mixtures of their resins include, but are not limited to these resins.
In order to reduce the amount of organic matter eluted from the low-eluting polyethylene film, the following methods can be mentioned, but the method is not limited thereto.

When producing polyethylene, it is effective to reduce the residual amount of unreacted raw materials, the amount of low molecular weight products and by-products, and to remove the polymerization catalyst. Specifically, it improves the purity of raw materials, precisely controls conditions such as reaction temperature and pressure, and removes unreacted raw materials, low molecular weight products, by-products, and polymerization catalysts by distillation and washing. Examples thereof include a method of preventing oxidation due to contact with oxygen in the air at a high temperature.
When pelletizing the produced polyethylene, there is a method of limiting the use of lubricants, antioxidants, and other additives that are likely to increase the elution amount of organic substances.

When forming polyethylene into a film, there is a method of limiting the use of lubricants, antioxidants, solvents, and other additives that are likely to increase the amount of organic matter elution to prevent oxidation due to high temperatures. Can be mentioned.

Since the sealant film of the laminate of the present invention has heat-sealing properties and contains low-eluting polyethylene, the packaging material containing the laminate has excellent heat-sealing properties and the amount of organic substances eluted is high. It is possible to reduce the increase in the TOC concentration of the liquid content in the package.
Further, polyethylene is suitable in that it is resistant to sterilization and sterilization treatments such as UV and has a property of being hard to be decomposed.
Among these low-eluting polyethylenes, LLDPE is preferable as the type, and further, LLDPE having side chains of C4, C6, and C8 tends to reduce the elution amount of organic substances, and therefore C4-LLDPE. , C6-LLDPE, C8-LLDPE and the like are more preferable.

Here, C4, C6, and C8 are partially copolymerized with LLDPE, indicating that the monomer having the number of carbon atoms described is present in the side chain. For example, C4 represents butene-1, C6 represents hexene-1, or 4-methylpentene-1, and C8 represents the side chain of the structure of octene-1.
Alternatively, low-eluting polyethylene having a density of 0.90 g / cm ³ or more and 0.94 g / cm ³ or less is preferable, and low-eluting polyethylene having a density of 0.905 g / cm ³ or more and 0.933 g / cm ³ or less is preferable. More preferred. Low-eluting polyethylene with a density in this range tends to reduce the amount of organic matter eluted.
Further, the low-eluting polyethylene can also contain a small amount of additives such as an antioxidant and an anti-blocking agent.
Furthermore, it is preferable that the low-eluting polyethylene in the present invention is excellent in pinhole resistance due to bending when it is formed into a film by itself.

Fatigue fracture may progress and pinholes may occur in the packaging due to local repeated bending due to vibration during the packaging process or transportation. Therefore, packaging materials for foods and medical supplies are particularly resistant to pinholes. is important.
The pinhole resistance of the low-eluting polyethylene in the present invention is, for example, that the number of pinholes generated in a 50 μm-thick film made of a low-eluting polyethylene alone after 5000 gelboflexes at 23 ° C. is 0. Alternatively, the number is preferably 1 or more and 160 or less.
When the number of pinholes generated in the film of the sealant layer is within the above range, a packaging material that can withstand practical use can be produced in the case of applications requiring pinhole resistance.

<Odor adsorption layer>
The odor adsorbing layer in the present invention is formed from the resin composition containing the above-mentioned low-eluting polyethylene and an odor adsorbent.
Furthermore, general-purpose polyethylene, polypropylene, methylpentene polymer, acid-modified polyolefin-based resin, and a mixture of these thermoplastic resins may be contained within a range that does not impair the low elution property and heat-sealing property of the sealant film. It is possible, but not limited to these resins.

[Odor adsorbent]
In the present invention, the odor adsorbent is an inorganic porous body on which a chemical adsorbent is carried, and is used to sterilize and sterilize elution organic substances, UV irradiation, γ-ray irradiation, EB irradiation, hot packs, boil and the like. It has a function of adsorbing odorous substances generated from the package during processing.
As a supporting method, a known or conventional supporting method can be applied. For example, the inorganic porous body may be impregnated with a solution containing a chemical adsorbent described below and dried to support the inorganic porous material. can.
In the present invention, by containing the odor adsorbent in which the chemical adsorbent is carried on the inorganic porous body in the odor adsorbent layer, the adsorbing ability per unit mass of the chemical adsorbent can be significantly enhanced, and the adsorbing ability per unit mass of the chemical adsorbent can be significantly enhanced. The content of the chemical adsorbent and the odor adsorbent can be reduced. In addition, physical adsorption characteristics for the pores of the inorganic porous body can be expected.
As a result, high sealing strength can be obtained, and the excellent heat-sealing property and film-forming property required for the sealant layer can be maintained.

If the content of the odor adsorbent is 0.1% by mass or more in the entire sealant layer, a sufficient adsorption effect can be exhibited, but in order to obtain a good adsorption effect as a package. , 0.3% by mass or more, and more preferably 0.5% by mass or more.
On the other hand, in order to obtain good film-forming property at the time of producing the laminate and to achieve good heat-sealing property, the content of the odor adsorbent should be 15% by mass or less in the entire sealant layer. It is preferable, and it is more preferable that it is 10% by mass or less.

The odor adsorbent may have any outer shape such as a spherical shape, a rod shape, or an elliptical shape, and may have any shape such as a powder shape, a lump shape, or a granular shape. From the viewpoint of uniform dispersion in a thermoplastic resin, kneading characteristics, and the like, powdery form is preferable.
The odor adsorbent can be appropriately selected from any average particle size depending on the intended use, but in the present invention, an odor adsorbent having an average particle size of 0.01 μm to 10 μm is particularly preferable, and 0.1 μm to 8 μm. Those having a diameter of 1 μm to 7 μm are more preferable. Here, the average particle size is a value measured by a dynamic light scattering method.

When the average particle size is smaller than 0.01 μm, aggregation of the odor adsorbent tends to occur, and the dispersibility of the odor adsorbent in the low-eluting polyethylene tends to decrease.
Further, when the average particle size is larger than 10 μm, the film-forming property of the odor adsorbing layer is inferior, so that it tends to be difficult to contain a large amount of the odor adsorbent, and there is a possibility that a sufficient adsorbing effect cannot be obtained.

Specific examples of commercially available products include NS-241 and NS-231 (amino group-containing compound-supporting inorganic porous material) manufactured by Toa Synthetic Co., Ltd., and Dashlite M (Cinannenzeomic Co., Ltd., amino group-containing compound-supporting inorganic material). A porous body) or the like can be used as a suitable odor adsorbent in the present invention.

[Inorganic porous body]
In the present invention, any inorganic compound having a large number of pores on its surface can be used as the inorganic porous body, and for example, inorganic phosphoric acid such as zeolite, silicon dioxide, silicate, activated carbon, titania, and calcium phosphate. Examples include salts, alumina, aluminum hydroxide, magnesium hydroxide, and mixtures thereof.
In particular, it is preferable to apply aluminum hydroxide, zeolite, or silicate from the viewpoint of having a porous state with a pore size effective for the molecular size and cluster size of the substance to be adsorbed and from the viewpoint of safety.
Further, these may have any external shape such as a spherical shape, a rod shape, an elliptical shape, etc., and may have any shape such as a powder shape, a lump shape, a granular shape, etc. After that, the powdery state is preferable from the viewpoints of film forming property of the odor adsorbing layer, uniform dispersion in the thermoplastic resin, kneading property and the like.

As the inorganic porous body, one having an average particle diameter can be appropriately selected depending on the intended use, but in the present invention, one having an average particle diameter of 0.01 μm to 10 μm is particularly preferable, and 0.1 μm to 8 μm. Those having a diameter of 1 μm to 7 μm are more preferable.
When the average particle size is smaller than 0.01 μm, the odor adsorbent tends to aggregate, the dispersibility of the odor adsorbent in the thermoplastic resin tends to decrease, and the average particle size is larger than 10 μm. If it is large, the film-forming property of the odor adsorbing layer tends to be inferior, so that it tends to be difficult to contain a large amount of the odor adsorbent, and there is a possibility that a sufficient deodorizing effect cannot be obtained.

[Chemisorbent]
In the present invention, the chemical adsorbent has a reactive functional group that chemically reacts with an elution organic substance or an odorous substance generated by decomposition of a resin during sterilization / sterilization treatment, and has the above-mentioned inorganic substance. A compound that can be carried on a porous body.
More specifically, a functional group having reactivity to bind to various aldehydes, ketones, carboxylic acids and the like generated during UV irradiation, γ-ray irradiation, EB irradiation, sterilization / sterilization treatment such as hot pack and boil. It is a compound that has.
Examples of such a compound include a compound containing an amino group, for example, a polyamine such as an alkylamine and a tetramethylenediamine, and a compound having a basic functional group such as ethanolamine, piperidine and a hydroxyl group, for example, sodium hydroxide and hydroxylation. Hydroxides such as potassium, magnesium hydroxide and iron hydroxide, carbonates such as sodium carbonate, sodium hydrogencarbonate and calcium carbonate, hydrogen carbonates and amide group-containing compounds such as 2-acrylamide-2-methylpropanesulfonic acid and the like. Can be mentioned.

In the present invention, examples of the chemical adsorbent exhibiting a particularly excellent adsorption effect include compounds having an amino group such as polyamines such as ethylenediamine, diethylenetriamine, triethylenetriamine, tetraethylenepentamine, piperazine and metaphenylenediamine. However, it is not limited to these.

The adsorption mechanism of the odor adsorbent for the substance to be adsorbed such as the eluted organic substance and the odorous substance will be described in more detail with reference to the specific examples of FIGS. 4A to 4B, but the present invention is not limited thereto.
For example, when the substance to be adsorbed is an acid-based odorous substance, as shown in FIG. 4A, as the odor adsorbent, for example, an odor adsorbent in which a compound having a hydroxyl group is supported on an inorganic porous body is used. Can be used. As a result, the carboxyl group and the hydroxyl group cause a chemical reaction to bond with each other, and the substance to be adsorbed is adsorbed.

When the substance to be adsorbed is an aldehyde, as shown in FIG. 4B, for example, an odor adsorbent in which a compound having an amino group is supported on an inorganic porous body is used as the odor adsorbent. Can be done. As a result, the aldehyde group and the amino group cause a chemical reaction to bond with each other, and the substance to be adsorbed is adsorbed.
At this time, due to the chemical adsorption, the substance to be adsorbed once adsorbed does not desorb, and the odor can be efficiently adsorbed.

Further, unlike the physical adsorbent in which odor and water vapor are adsorbed on the same adsorption site, the chemical adsorbent in the present invention has an odor adsorption ability because the substance to be adsorbed binds to a specific functional group of the chemical adsorbent. It is not easily affected by various substances that reduce the amount of water, such as water vapor.

In one aspect of the present invention, the odor adsorbing layer is a single layer structure formed by using a resin composition obtained by kneading an odor adsorbent and low-eluting polyethylene. Here, the odor adsorbent may be uniformly dispersed in the layer, or may be dispersed with a concentration gradient.
For example, it may be dispersed from the inner surface to the outer surface at the time of forming the package with an increasing concentration gradient, and this configuration improves the heat sealability. On the contrary, the particles may be dispersed from the inner surface to the outer surface at the time of forming the package with a decreasing concentration gradient, and this configuration improves the interlayer adhesion strength.
Further, the odor adsorbing layer may be dispersed from the central portion in the thickness direction toward both surfaces with a decreasing concentration gradient, and this configuration improves the heat sealability and the interlayer adhesion strength.

In still another embodiment, the odor adsorbing layer may have a multi-layer structure in which two or more layers are laminated, wherein each layer is a type of main low-eluting polyethylene or an odor adsorbent. It may consist of resin compositions having different types and contents.
A film can be formed if the thickness of the entire odor adsorbing layer is 5 μm or more, but it is preferably 10 μm to 200 μm in order to obtain good film forming property, heat sealing property, interlayer adhesion strength and odor adsorbing property.

<Non-odor adsorption layer>
The non-odor adsorbing layer in the present invention comprises a resin composition containing low-eluting polyethylene or low-eluting polyethylene (hereinafter, both are collectively referred to as "resin composition containing low-eluting polyethylene"). Although it is a layer, it is a layer that does not contain an odor adsorbent.
Furthermore, general-purpose polyethylene, polypropylene, methylpentene polymer, acid-modified polyolefin-based resin, and a mixture of these thermoplastic resins may be contained within a range that does not impair the low elution property and heat-sealing property of the sealant layer. It is possible, but not limited to these resins.

<Base layer>
In the present invention, various materials can be applied to the base material layer depending on the type of contents to be packaged, mechanical strength, chemical resistance, solvent resistance, manufacturability and the like required for physical distribution. It is preferable to use a thermoplastic resin.
Examples of the type of resin include polyethylene resin, polypropylene resin, cyclic polyolefin resin, fluororesin, polystyrene resin, acrylonitrile-styrene copolymer (AS resin), and acrylonitrile-butadiene-styrene copolymer (ABS). Resin), polyvinyl chloride resin, ethylene-vinyl alcohol copolymer, fluororesin, poly (meth) acrylic resin, polycarbonate resin, polyethylene terephthalate (PET), polyester resin such as polyethylene naphthalate, various types. Polyamide resin such as nylon, polyimide resin, polyamideimide resin, polyarylphthalate resin, silicone resin, polysulfone resin, polyphenylene sulfide resin, polyether sulfone resin, polyurethane resin, acetal resin, cellulose A film containing various resins such as a based resin can be used.
Among the films containing the above resins, in the present invention, the substrate layer is preferably an unstretched nylon film, a stretched nylon film, a PET film, a linear low-density polyethylene film, or a low-density polyethylene film, and is particularly polyethylene-based. A linear low-density polyethylene film, a low-density polyethylene film, and an unstretched nylon film, which are resin films, are preferable. Further, it is preferable to use a low-eluting polyethylene resin as the polyethylene-based resin film.
The base material layer preferably contains a film using one or more kinds of resins selected from the above, and even if it is composed of one layer, it is composed of two or more layers having the same composition or different compositions. May be.
In the present invention, the substrate layer may be a single layer or a multilayer film formed by a film forming method such as an extrusion method, a cast molding method, a T-die method, a cutting method, or an inflation method. The thickness of the base material layer can be appropriately determined by those skilled in the art depending on the packaging application, but is preferably 6 to 150 μm, more preferably 9 to 130 μm.
Further, the base material layer in the laminate of the present invention has processability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidant properties, slipperiness, releasability, flame retardancy, and resistance of the laminate. Various reforming resins, plastic compounding agents, additives and the like can be added for the purpose of improving and modifying mold properties, electrical properties, strength and the like. In this case, these additives may be arbitrarily contained in the base material layer from a very small amount to several tens of mass% depending on the purpose. In the present invention, general additives include colorants such as lubricants, cross-linking agents, antioxidants, ultraviolet adsorbents, light stabilizers, fillers, antistatic agents, lubricants, antiblocking agents, dyes and pigments. Etc. can be arbitrarily contained.
Furthermore, the base material layer may have a resin layer of various materials in order to impart high elasticity and pinhole resistance. For example, it may have layers of 6 nylon, 66 nylon, 6/66 nylon copolymer, low density polyethylene, ethylene-vinyl alcohol copolymer, etc., and in particular, it may have a layer of 6/66 nylon copolymer. preferable.

<Formation of odor adsorption layer and non-odor adsorption layer>
(Dispersion method of odor adsorbent)
As a method for kneading the odor adsorbent and the low-eluting polyethylene, a known or conventional kneading method can be applied.
The odor adsorbent can be directly mixed with low-eluting polyethylene and kneaded, or the odor adsorbent is mixed with a thermoplastic resin at a high concentration and then melt-kneaded to prepare a masterbatch. It is also possible to use a so-called masterbatch method in which the polyethylene is mixed with low-eluting polyethylene at a ratio according to the target content and melt-kneaded.

The mass ratio of the odor adsorbent / thermoplastic resin in the masterbatch is preferably 0.5 / 99.5 to 40/60, more preferably 1/99 to 30/70.
In the case of the masterbatch method, even a combination of an odor adsorbent in which aggregation is likely to occur and low-eluting polyethylene can be uniformly dispersed.
At this time, the thermoplastic resin in the masterbatch does not have to be the same as the low-eluting polyethylene in the odor adsorption layer, and the same type of low-eluting polyethylene or other thermoplastic resin may be combined according to the purpose. Is possible.

For example, if an odor adsorbent and low-eluting polyethylene are melt-mixed in advance, when they are mixed or melt-kneaded again with low-eluting polyethylene, they are homogeneous and have good film-forming property, heat-sealing property, and interlayer adhesion strength. And it is possible to obtain odor adsorption.
Examples of the thermoplastic resin other than the low-eluting polyethylene in the odor adsorption layer include general-purpose non-low-eluting polyethylene, polypropylene, methylpentene polymer, polyolefin resins such as acid-modified polyolefin resins, and mixtures of these resins. However, the present invention is not limited to these resins.
The thermoplastic resin preferably has a low elution property equivalent to that of the low elution polyethylene in the present invention, but a general-purpose resin is used as long as it does not significantly adversely affect the amount of organic substances eluted from the entire sealant layer. Can be used.

(Film formation / lamination method)
In the present invention, the film forming and laminating methods for each layer of the sealant layer and the base material layer are not particularly limited, and known or conventional film forming methods and laminating methods can be applied.
An odor-adsorbing layer or a non-odor-adsorbing layer may be laminated by extrusion-coating on another layer, optionally via an adhesive layer, or, for example, a plurality of odor-adsorbing layers and non-odor-adsorbing layers may be laminated. It can also be formed by coextrusion by the inflation method or the casting method.

When laminating by extrusion coating, first, the resin composition forming the odor adsorption layer and the resin composition forming the non-odor adsorption layer are heated and melted, and then expanded and expanded in the required width direction with a T-die. The molten resin is allowed to flow down onto the surface to be laminated and sandwiched between a rubber roll and a cooled metal roll to form an odor-adsorbing layer or a non-odor-adsorbing layer and adhere to the surface to be laminated. And laminating at the same time.
The melt flow rate (MFR) of the low-eluting polyethylene contained in the odor-adsorbing layer and the thermoplastic resin contained in the non-odor-adsorbing layer when laminated by the extrusion coating shall be 0.2 to 50 g / 10 minutes. Is preferable, and more preferably 0.5 to 30 g / 10 minutes. In this specification, MFR is a value measured by a method based on JIS K7210.
If the MFR is less than 0.2 g / min or 50 g / min or more, it is difficult to be effective in terms of processing suitability.
When the inflation method is used, the melt flow rate (MFR) of the low-eluting polyethylene contained in the odor adsorption layer and the thermoplastic resin contained in the non-odor adsorption layer is 0.2 to 10.0 g / 10 minutes. It is preferably 0.2 to 9.5 g / 10 minutes.
If the MFR is less than 0.2 g / 10 min or 10.0 g / 10 minutes or more, it tends to be inferior in terms of processing suitability.

Alternatively, the odor-adsorbing layer and the non-odor-adsorbing layer formed in advance may be laminated via the adhesive layer by dry lamination, non-solvent lamination, sand lamination or the like.

<Adhesive layer>
In the present invention, it is also possible to provide an adhesive layer between the sealant layer-base material layer and each layer of the sealant film and laminate them.
The adhesive layer may consist of an adhesive or any anchor coating agent.
The adhesive may be a thermosetting type, an ultraviolet curing type, an electron beam curing type, or the like, and may be in any form such as an aqueous type, a solution type, an emulsion type, a dispersed type, and the properties thereof are film / sheet. It may be in any form such as a form, a powder form, a solid form, and the like, and the bonding mechanism may be any form such as a chemical reaction type, a solvent volatilization type, a thermosetting type, and a thermosetting type.

The adhesive layer may be an EC (extrusion coat) layer, a dry laminating adhesive, a non-solvent laminating adhesive, or the like.
The components forming such an adhesive layer include polyvinyl acetate adhesives such as polyvinyl acetate and vinyl acetate-ethylene copolymers, and copolymers of polyacrylic acid with polystyrene, polyester, polyvinyl acetate and the like. Polyacrylic acid adhesive, cyanoacrylate adhesive, ethylene copolymer adhesive consisting of a copolymer of ethylene and monomers such as vinyl acetate, ethyl acrylate, acrylic acid, and methacrylic acid, cellulose adhesive, Polyurethane adhesive, polyester adhesive, polyamide adhesive, polyimide adhesive, polyolefin adhesive such as LDPE, amino resin adhesive composed of urea resin or melamine resin, phenol resin adhesive, epoxy adhesive Adhesives, reactive (meth) acrylic adhesives, chloroprene rubbers, nitrile rubbers, elastomeric adhesives made of styrene-butadiene rubbers, silicone adhesives, alkali metal silicates, inorganic adhesives made of low melting point glass, etc. And so on.

As the anchor coating agent, for example, an organic titanium-based, isocyanate-based, polyethyleneimine-based, acid-modified polyethylene-based, polybutadiene-based anchor coating agent can be used.
When the adhesive layer is laminated with an extrusion coating, the adhesive can be formed by an extrusion coating on the layer to be adhered, without particular limitation.

In the extrusion coating, first, the adhesive is heated and melted, expanded and stretched in the required width direction with a T-die, extruded into a curtain shape, and the melt is allowed to flow down onto the layer to be bonded to be cooled with a rubber roll. By sandwiching it with the metal roll, the adhesive layer is formed, and the adhesive layer is adhered to and laminated at the same time.

When an adhesive for dry laminating is used as the adhesive layer, an adhesive dispersed or dissolved in a solvent is applied onto one layer, dried, and the other layer to be adhered is laminated and then laminated at 30 to 120 ° C. By aging for several hours to several days, the adhesive is cured and laminated.
When using a non-solvent laminating adhesive, the adhesive itself is applied onto the layer without being dispersed or dissolved in a solvent, dried, and the other layer to be bonded is laminated and then laminated at 30 to 120 ° C. By aging for several hours to several days, the adhesive is cured and laminated.
The adhesive layer is formed by applying the above adhesive with, for example, a roll coat, a gravure roll coat, a kiss coat, or the like, and the coating amount thereof is preferably about 0.1 to 10 g / m ² (dry state). Good adhesiveness can be obtained by setting the coating amount of the adhesive within the above range.
When each layer of the sealant layer is laminated by sand lamination, any resin that can be heated and melted and applied by an extruder can be used as the adhesive layer. Specifically, the thermoplastic resin used for the above-mentioned non-odor adsorbing layer can be preferably used.

<Packaging material>
The packaging material for packaging the liquid contents of the present invention is made from the laminate for packaging the liquid contents of the present invention, and may be composed only of a base material layer and a sealant layer, if necessary. It is also possible to have a functional material layer, an adhesive layer and the like. As the functional layer, the adhesive layer and the like, known ones can be laminated and used by a known method.

<Packaging>
The liquid content packaging of the present invention is, for example, made by making a bag of the packaging material for packaging the liquid content of the present invention, and whether the packaging material is bent so that the surfaces having good heat sealability face each other. Alternatively, two sheets are overlapped, and the peripheral ends thereof are, for example, side seal type, two-way seal type, three-way seal type, four-way seal type, envelope-attached seal type, gassho-attached seal type (pillow-seal type), and fold-attached seal type. , Flat-bottomed seal type, square-bottomed seal type, gusset type, etc. can be manufactured by heat-sealing.
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, or an ultrasonic seal can be applied.

<Liquid contents>
In the present invention, the liquid content refers to all seasoning liquids such as drinking water, juices, infusions for drip, soy sauce, sauces, and liquids such as soups, honeys, sauces, and dressings.

The details of the raw materials used in the examples are as follows.
[Base layer film]
Base material layer film A: Multitron (manufactured by Tamapoli Co., Ltd., a three-layer film consisting of a PE layer of 25 μm / a non-stretched nylon layer of 20 μm / a PE layer of 25 μm)
[Low-eluting polyethylene and high-eluting polyethylene]

[Odor adsorbent]
-Kesmon NS-241: An amino group-containing compound-supporting inorganic porous body manufactured by Toagosei Co., Ltd. Average particle size 3.5 μm.
-Dashlite M: An amino group-containing compound-supported inorganic porous body manufactured by Sinanenzeomic Co., Ltd. Average particle size 6-7 μm.
KD-311: An inorganic porous body having an amino group manufactured by Rasa Industries, Ltd. Particle size 10 μm
Less than.
The masterbatch was prepared by adjusting as follows.
[Adjustment of masterbatch 1]
Ultozex 1520L, which is a low-eluting polyethylene LLDPE, and Kesmon NS-241, which is an odor adsorbent, were melt-blended at the following ratios to obtain Masterbatch 1 (MB1).
Ultozex 1520L 90 parts by mass Kessmon NS-241 10 parts by mass [Adjustment of master batch 2-5]
According to the formulation shown in Table 2, the same as Masterbatch 1 was melt-blended to obtain Masterbatch 2-5 (MB2-5).

<Example 1>
The masterbatch 1 obtained above and Ultozex 1520L were dry-blended at the following ratios to obtain a mixture for an odor adsorption layer.
Master batch 1 16.7 parts by mass Ultozex 1520L 83.3 parts by mass Then, the mixture obtained above and Ultozex 1520L for a non-odorous adsorption layer are laminated at 160 ° C. by inflation membrane formation to adsorb non-odorous substances. A three-layered sealant film having a layer of 10 μm, an odor adsorption layer of 30 μm, and a non-odor adsorption layer of 10 μm was obtained.

Next, the sealant film obtained above and the base material layer film A were laminated under the following conditions by EC (extraction coating) of the adhesive layer material to obtain a film-like laminate, and the obtained laminate was obtained. Was used as a packaging material, and the film-forming property, puncture strength, pinhole resistance, TOC elution concentration (adsorption effect), and odor change were evaluated. Table 3 shows the detailed configuration and evaluation results of the laminated body.

(Approximate layer structure of the laminated body)
Base material layer Film A (70 μm) / EC layer (15 μm) / Sealant layer (50 μm) (total thickness 135 μm)
(Laminating condition)
Extrusion temperature: 330 ° C
Adhesive layer material: LDPE (Novatec LC520)
Adhesive layer thickness: 15 μm

<Examples 2 to 13, Comparative Examples 2 and 3>
According to the configuration of Table 3, a sealant film was obtained in the same manner as in Example 1, and a laminate was prepared and evaluated. Tables 3 and 4 show the detailed configuration and evaluation results of the laminated body.

<Example 14>
The masterbatch 2 obtained above and Ultozex 1520L for the non-odor adsorbing layer were dry-blended at the following ratios to obtain a mixture for the odor adsorbing layer.
Masterbatch 2 16.7 parts by mass Ultozex 1520L 83.3 parts by mass The above mixture, Ultozex 1520L, Ultozex 2021L, and unstretched nylon (UBE 5033B, polyamide 6/66 copolymer weight, manufactured by Ube Industries, Ltd.) Using a modified polyolefin (Admar NF557, manufactured by Mitsui Chemicals, Inc.) for the adhesive layer between the unstretched nylon layer and the unstretched nylon layer, a laminate having the following layer structure was obtained by an inflation method, and the obtained laminate was used as a packaging material. It was used to evaluate piercing strength, pinhole resistance, TOC elution concentration, and odor change. The evaluation results are shown in Table 4.

(Laminate layer structure)
Ultozex 2021L (10μm) / Ultozex 1520L (30μm) / Adhesive layer 10μm / Unstretched nylon layer (20μm) / Adhesive layer 10μm / Odor adsorption layer (30μm) / Ultozex 2021L (10μm) (total thickness 120μm)

<Comparative Example 1>
An inflation film was formed at 160 ° C. using LLDPE Evolu SP2020 with high-eluting polyethylene to obtain a sealant film (50 μm).

Then, it was laminated with the base film A in the same manner as in Example 1 to obtain a laminated body, and evaluated in the same manner as in Example 1. Table 4 shows the detailed layer structure and evaluation results of the laminated body.

<Evaluation>
[Film formation]
The appearance of the sealant and the laminate was observed and sensually evaluated. The evaluation criteria are as follows.
◯: Film formation is possible without wrinkles or bumps on the sealant and laminate.
×: Many wrinkles and bumps occur on the sealant and the laminate, making film formation difficult.

[Heat sealability]
The laminates produced in Examples and Comparative Examples are cut into 10 cm × 10 cm pieces, folded in half so that the sides of the odor adsorption layers face each other (arbitrarily for Comparative Examples 1 and 2), and overlapped with each other, and heat-sealed tester (tester industry). A sample in which a region of 1 cm × 10 cm was heat-sealed was prepared using TP-701-A) (the end portion was not heat-sealed and was not adhered and was bifurcated). This sample was cut into strips with a width of 15 mm, and each bifurcated end was attached to a tensile tester to measure the tensile strength (N / 15 mm).
Heat seal condition Temperature: 160 ℃
Pressure: 1kgf / cm ²
Time: 1 second Tensile strength test conditions Test speed: 300 mm / min Load range: 50 N
Pass / Fail Judgment ○: 30N / 15mm or more, pass.
×: Less than 30N / 15mm and failed.

[Puncture strength]
The laminates prepared in Examples and Comparative Examples were cut to prepare strips of 120 mm × 80 mm, which were used as test samples. The puncture strength of each test sample was measured by a tensile compression tester (SA-1150 manufactured by ORIENTEC) by a method according to JIS Z 1707 1997.

[Pinhole resistance]
The resin film or the laminate prepared in Examples and Comparative Examples is cut into A4 size (30 cm × 21 cm), bent with a gelboflex tester (BE-1005 manufactured by Tester Sangyo Co., Ltd.), and then each sample is prepared. The number of pinholes generated in the plane of 30 cm × 21 cm was counted.
Temperature: 23 ° C
Gerbo bending frequency: 5000 times

[Adsorption effect]
(Increased concentration of filled water TOC)
A pouch bag (15 cm × 44 cm) package was prepared using the resin film or the laminate prepared in Examples and Comparative Examples. The inner surface of the pouch bag was previously subjected to UV irradiation sterilization treatment.
Then, the obtained package was filled with 1000 g of water at 65 ° C. (distilled water for high performance liquid chromatography, genuine chemistry) to prepare a packaged liquid filler, and after storage at 35 ° C. for 2 weeks, Co., Ltd. The TOC concentration of the filled water was measured by a TOC-L total organic carbon meter manufactured by Shimadzu Corporation.

Next, the TOC concentration of the water before filling was measured in the same manner.
The TOC increase concentration in each package was calculated from the following formula.
TOC increase concentration = TOC concentration of filled water after storage-TOC concentration of water before filling TOC concentration of water before filling: 0.02 ppm
UV irradiation sterilization treatment conditions UV wavelength: 253.7 nm
Irradiation time: 10 seconds
Temperature: 25 ° C

(Taste change)
A pouch bag (13 cm × 17 cm) was prepared using each of the laminates obtained in Examples and Comparative Examples. The inner surface of the pouch bag was previously subjected to UV irradiation sterilization treatment. The UV irradiation sterilization treatment conditions were the same evaluation conditions as the TOC elution concentration.
The pouch bag obtained here is filled with 100 g of water heated to 65 ° C (manufactured by Suntory Ltd., natural water in Japan) in a hot pack to prepare a package liquid filling, and then at 10 ° C, 1 A sensory evaluation was performed after weekly storage.
The evaluation indicators are as follows. There were 5 participants in the sensory evaluation experiment, and the average value was calculated and used as the evaluation result.
1: Strong odor 2: Slightly reduced odor 3: Significantly reduced odor 4: Equivalent to natural water before filling

<Summary of results>
The packages of all the examples using low-eluting polyethylene showed good film-forming property, seal strength, piercing strength, TOC increase concentration, and odor change.
Further, Examples 1 to 7, 10 to 14 using low-eluting polyethylene having excellent pinhole resistance are superior to Examples 8 and 9 using low-eluting polyethylene having inferior pinhole resistance. It showed pinhole resistance.
In Comparative Example 1 having no odor adsorption layer, the TOC increase concentration was large and the odor change was also bad.
Comparative Example 3 in which the odor adsorbing layer did not contain low-eluting polyethylene showed good film-forming property and sealing strength, but the TOC increase concentration was large.

1. 1. Sealant layer 2. Non-odor adsorption layer 3. Odor adsorption layer 3a. Odor adsorption layer (concentration a)
3b. Odor adsorption layer (concentration b)
4. Base material layer

Claims (11)

A laminate for packaging liquid contents, which has a base material layer and a sealant layer.
The sealant layer has at least an odor adsorption layer and has.
The odor adsorption layer is a layer for adsorbing an odorous substance generated from a resin constituting the packaging material during sterilization / sterilization treatment together with an elution organic substance contained in the packaging material.
The sealant layer contains low-eluting polyethylene and
The density of the low-eluting polyethylene is 0.90 g / cm ³ or more and 0.94 g / cm ³ or less.
The odor adsorbing layer is formed of a resin composition containing a low-eluting polyethylene and an odor adsorbent.
The concentration of the elution TOC contained in the film made of the low-eluting polyethylene is 42 ppm or more and 99 ppm or less.
The sealant layer is one layer composed of only the odor adsorption layer, two layers composed of the odor adsorption layer and the non-odor adsorption layer, or the non-odor adsorption layer, the odor adsorption layer and the non-odor adsorption layer in this order. It is a layer structure of any of the three arranged layers.
The odor adsorbent is an inorganic porous body carrying a chemical adsorbent.
Laminate for packaging liquid contents. The laminate for packaging liquid contents according to claim 1 , wherein the low-eluting polyethylene is LLDPE. The laminate for packaging liquid contents according to claim 1 or 2 , wherein the low-eluting polyethylene is one or more selected from the group of C4-LLDPE, C6-LLDPE, and C8-LLDPE. Claims 1 to 3 in which the number of pinholes generated after 5000 times of gelboflex at 23 ° C. in a 50 μm-thick film made of the low-eluting polyethylene simple substance is 0, or 1 or more and 160 or less. The laminate for packaging liquid contents according to any one of the above items. In the odor adsorbent, the mass ratio of the thermoplastic resin and the odor adsorbent / thermoplastic resin is 0 in advance.
.. The laminate for packaging liquid contents according to any one of claims 1 to 4 , which is melt-kneaded at a ratio of 5 / 99.5 to 40/60. The laminate for packaging liquid contents according to claim 5 , wherein the melt flow rate of the thermoplastic resin is 0.2 to 10.0 g / 10 minutes. The laminate for packaging liquid contents according to any one of claims 1 to 6 , wherein the content of the odor adsorbent is 0.3% by mass or more and 15% by mass or less in the total sealant film. .. Any one of claims 1 to 7 , wherein the chemisorbent has a functional group having reactivity with one or more selected from the group of aldehydes, ketones, and carboxylic acids. The laminate for packaging liquid contents as described in the section. The laminate for packaging liquid contents according to any one of claims 1 to 8 , wherein the chemical adsorbent has an amino group. A packaging material for liquid contents, which is produced by using the laminate for packaging liquid contents according to any one of claims 1 to 9 . A package for liquid contents formed from the packaging material for liquid contents according to claim 10 .

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