JP2021167213A - Standing pouch with plug - Google Patents

Abstract

To provide a standing pouch with a plug that has excellent gas barrier property and reusability.SOLUTION: A standing pouch with a plug, in which a lamination body is laminated at least a barrier film layer, an adhesive layer, and a sealant layer in this order, the barrier film layer is composed of a film having a thickness of 20 to 40 μm made of high-density polyethylene having a density of 0.940 to 0.980 g/cm3 and a barrier layer formed on the film, the sealant layer is made of a 100-150 μm thick film made of linear low-density polyethylene having a density of 0.910 to 0.920 g/cm3, the plug is made of high-density polyethylene having a density of 0.96 g/cm3 or less and a MFR of 5 g/10 min or more.SELECTED DRAWING: None

Description

The present invention relates to a standing pouch with a spout, and more particularly to a standing pouch with a spout that reduces the environmental load in which materials can be easily reused.

There are various types of packaging depending on the nature of the contents to be packaged, the amount of contents, post-treatment to protect the deterioration of the contents, the form of transporting the packaging, the method of opening the packaging, the method of disposal, etc. The materials are used in combination.

For example, standing pouches are widely used because they allow products to stand out on store shelves, are lighter than plastic bottles, and are easy to dispose of. In particular, the pouch with a spout is expanding its use because it can impart recloseability to foods such as jelly drinks, soft drinks, raw soy sauce, and sake, and to package liquid contents such as shampoo and rinse toiletries.

In the standing pouch, in order to make the characters and patterns on the entire surface of the pouch visible without the pouch bending in the middle in a self-supporting state, the laminated body constituting the pouch is required to have rigidity. Further, if the content is a liquid, strength is required so that the bag does not break when dropped. In order to support these functions, a laminate in which a polyester film, a nylon film, a polyolefin film, or the like is combined has been conventionally used.

Further, the material of the spout composed of the spout and the cap is not particularly limited as long as it does not adhere to the pouch, elute into the contents, or adsorb the contents, and various thermoplastic resins have been used.

However, due to the growing awareness of environmental problems in recent years, functions such as resource saving and reuse of various products have been required, and the same function is also required for the laminate used for the packaging.

One method of reusing a laminate in which various materials are composited is a method of re-separating each material, but it is thermally and chemically used to separate a laminate having a predetermined strength as a package. It is necessary to perform various physical and mechanical actions. In addition, in order to separate the separated materials, it is necessary to perform physical action by specific gravity or different spectroscopic methods for each material, but the more we try to improve the accuracy of these separation and separation, the more It was not efficient, such as spending more energy.

Another method is to construct the original laminate with materials of the same type and reuse the laminate as an integral material. In particular, there are various types of thermoplastic resins such as polyolefin-based, polyester-based, and polyamide-based materials. Each can be imparted with various properties depending on the molecular weight, the state such as molecular weight distribution, heat treatment, orientation, stretching, and treatment. In particular, polyolefin-based materials are easy to use because they have a low melting point and therefore have good workability, and because various materials are manufactured from copolymers and the like. Therefore, various methods have been proposed so far.

Patent Document 1 proposes a laminate in which two films called an outer web and an inner web are laminated with a print layer interposed therebetween. Both the outer web and the inner web have a multi-layer structure of high-density polyethylene and low-density polyethylene, but since they are co-extruded films, special equipment is required. The inner web also acts as a sealant layer in the packaging, where ethylene-vinyl acetate (EVA) and ionomers are also recommended. However, these resins are liable to undergo chemical changes such as cross-linking during recycling, and are liable to generate impurities such as gels due to repetition.

Further, the laminate for packaging is often required to have properties such as oxygen barrier property and water vapor barrier property. Patent Document 1 recommends a resin such as EVOH, but in that case, an adhesive resin. Adhesive strength with the upper and lower layers cannot be obtained, and gel or the like is likely to be formed by repeated heat treatment as in EVA or the like, which may hinder reuse.

Patent Document 2 discloses a laminate composed of a uniaxially stretched polyolefin-based resin film and a polyolefin-based heat-sealing layer. The main object of the present invention is a laminated body having an easily tearable property due to a uniaxially stretched film, and as a result, a laminated body made of the same type of resin. However, there is no regulation on the strength of the package, and it is possible to stack films such as biaxially stretched nylon and polyester if necessary, and it is not a product that responds to environmental issues. No. Further, as a processing method for imparting openness to an arbitrary position / direction of a pouch, a method of forming minute scratches on a laminate by laser processing is known, but a polyolefin resin has weak laser absorption, so it is easy. It was difficult to give a good openness.

Special Table 2018-511504 Japanese Patent No. 5197952

An object to be solved by the present invention is to provide a standing pouch with a spout, which has excellent gas barrier properties and reusability.

In order to solve the above problems, the invention according to claim 1 of the present invention is a pouch of a standing pouch composed of two side wall laminates and one folded bottom laminate, and whose peripheral edges are sealed. A standing pouch with a spout having a spout and a cap on the upper side of the main body, wherein the side wall laminate and the bottom laminate are at least a barrier film layer, an adhesive layer, and a sealant layer. The barrier film layer is composed of a film having a thickness of 20 to 40 μm made of high-density polyethylene having a density of 0.940 to 0.980 g / cm ^{3 and a barrier layer formed on the film.} becomes, the sealant layer is made of a film having a thickness of 100~150μm consisting linear low density polyethylene having a density of 0.910~0.920g / cm ^3, the spout is, density 0.96 g / cm ³ or less , A standing pouch with a spout, which is made of high-density polyethylene having an MFR of 5 g / 10 min or more.

By providing a polyolefin-based laminate having a gas barrier property, it is possible to provide a standing pouch with a spout having excellent recyclability. Further, by adding a spout, the contents can be easily taken out.

Hereinafter, embodiments of the present invention will be described in detail.

The barrier film layer according to the present invention is a laminate of a film made of high-density polyethylene and a barrier layer.

As the high-density polyethylene, those having various densities and MFRs can be used, but those having a density of 0.940 to 0.980 g / cm ³ are preferable. If the density is ^{less than 0.940 g / cm 3} , the rigidity of the film is insufficient, and if the density is ^{larger than 0.980 g / cm 3} , the transparency is insufficient. Further, the transparency may be adjusted by adding a nucleating agent or the like to the high-density polyethylene. Further, the mechanical strength of the high-density polyethylene film may be adjusted by stretching treatment or heat treatment, and the adhesiveness of the surface may be adjusted by surface treatment such as corona treatment.

As the barrier layer used for the barrier film layer, a coating material obtained by adding an inorganic filler to polyvinyl alcohol (PVA), EVOH, or the like can be used. When these materials are used, they can be used as a coating layer having a thickness of about several μm.

More preferably, a vapor-deposited layer made of a metal oxide is used as the barrier layer. As the metal oxide, silicon oxide, aluminum oxide, tin oxide, magnesium oxide, or a mixture thereof can be used, but silicon oxide and aluminum oxide are preferable. A vacuum vapor deposition method, a sputtering method, an ion plating method, or a plasma vapor phase deposition method can be used to form the vapor deposition layer.

If the thickness of the vapor-deposited layer is too thin, it is difficult to form the vapor-deposited layer as a uniform continuous film, and sufficient gas barrier properties cannot be obtained. When the thickness is large, the flexibility is low, cracks are likely to occur due to bending and tension, and the gas barrier property is also lowered. The thickness of the thin-film deposition layer is preferably in the range of 5 nm to 500 nm.

Further, a gas barrier film layer can be provided on the barrier layer made of the metal oxide. The gas barrier film layer imparts higher barrier properties by protecting the barrier layer made of the metal oxide from mechanical deterioration, and provides a water-soluble polymer and one or more kinds of metal alkoxides or hydrolysis thereof. It can be composed of a material containing the product. The gas barrier film layer can be obtained by applying and drying an aqueous solution containing a water-soluble polymer and one or more kinds of metal alkoxides or hydrolysis products thereof, or a coating agent containing a water / alcohol mixed solution as a main component. can.

As the water-soluble polymer, for example, polyvinyl alcohol (PVA), polyvinylpyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, sodium alginate, or a mixture thereof can be used. In particular, when PVA is used, a gas barrier film layer having the most excellent gas barrier property can be formed.

The PVA is obtained by saponifying polyvinyl acetate, and varies from partially saponified PVA in which acetyl groups remain at several tens of percent to complete PVA in which only a few percent of acetyl groups remain. Can be used. The molecular weight of PVA is not limited, and for example, one having a degree of polymerization in the range of 300 to several thousand can be used.

The metal alkoxide is a compound represented by the general formula M (OR) _n. Here, M represents a metal such as Ti, AL, Zr or Si, and R represents an alkyl group such as _{CH 3} groups and C ₂ H _{5 groups.} n represents the valence of the element M. Examples of the metal alkoxide include tetraethoxysilane [Si (OC ₂ H ₅ ) ₄ ] and triisopropoxyaluminum [AL (O-2'-C ₃ H ₇ ) ₃ ], among which tetraethoxysilane and the like. After hydrolysis, triisopropoxyaluminum can exist relatively stably in a solution containing water.

When an alkoxysilane is used as the metal alkoxide, for example, ^{a compound represented by Si (OR 1} ) ₄ or R ² Si (OR ³ ) ₃ or a mixture thereof can be used as the alkoxysilane. Here, R ¹ and R ³ represent hydrolyzable groups such as _{CH 3} groups, C ₂ H ₅ groups, and C ₂ H ₄ OCH ₃ ^{groups, and R 2} represents an organic functional group.

Further, an adhesion layer containing an anchor coating agent may be provided between the high-density polyethylene film according to the present invention and the barrier layer. The adhesion layer can improve the adhesion between the high-density polyethylene film and the barrier layer made of a metal oxide, improve the smoothness of the film, and reduce defects in the vapor-deposited layer in the subsequent process. Examples of the material of the adhesion layer include polyester-based polyurethane resin and polyether-based polyurethane resin. Of these, polyester-based polyurethane resins are preferable from the viewpoint of heat resistance and interlayer adhesion strength.

The thickness of the adhesion layer is not particularly limited, but is preferably in the range of 0.05 to 2 μm. If the film thickness is too thin, the adhesion cannot be expected to be improved, and if the film thickness is too thick, impurities during reuse of the laminated body increase.

As the sealant layer that can be used in the present invention, ^{linear low-density polyethylene having a density of 0.910 to 0.920 g / cm 3} can be used, and the thickness of the sealant layer is preferably 100 to 150 μm. When the density is ^{smaller than 0.910 g / cm 3} , the film tends to block, and when the density is ^{larger than 0.920 g / cm 3} , the melting point rises and the melting point with the laminated high-density polyethylene approaches. It becomes difficult to make a bag. Further, when the thickness of the sealant becomes thin, the strength of the sealant against the contents such as liquid becomes insufficient, and when the thickness of the sealant becomes thick, it becomes difficult to heat-seal the sealant as a package.

The laminate according to the present invention can be produced by laminating and adhering a barrier film layer and a sealant layer by a laminating method such as a dry laminating method or a non-sol laminating method. The adhesive forming the adhesive layer can be selected according to the bonding method, but a urethane-based adhesive, a polyester-based adhesive, or the like can be used.

The side wall laminate and the bottom laminate of the standing pouch with a spout according to the present invention may have the same configuration or different configurations. It can be adjusted according to the type and weight of the contents.

In addition, character information, patterns, and the like may be printed on the barrier film layer of the laminated body according to the present invention, and gravure printing, flexographic printing, and the like are possible.

High-density polyethylene can be used for the spout and cap according to the present invention. As a result, the reusability of the entire package can be obtained. The high-density polyethylene preferably has a density of 0.96 / cm ³ or less and an MFR of 5 g / 10 min or more. Density heat sealability is lowered to become higher larger when the high-density polyethylene melting point than 0.96 / cm ^3. Further, if the MFR is smaller than 5 g / 10 min, the fluidity at the time of melting the resin is lowered and the productivity is lowered, which is not preferable. Further, the spout can be molded by a known molding method such as injection molding or compression molding.

The following will be described in more detail based on the examples.

The side wall laminate and the bottom laminate of the standing pouch with a spout according to the present invention were prepared as follows.

As the base material of the barrier film layer, ^{a high-density polyethylene film having a density of 0.960 g / cm 3} and a thickness of 30 μm was used.

The adhesion layer of the barrier layer was prepared by the following procedure.
[Coating liquid 1]: Adhesive solution manufactured by Mitsui Chemicals, Inc. (polyester polyurethane resin solution)
Main agent: Takelac A-525 (50% by mass of urethane resin precursor, 50% by mass of ethyl acetate)
Curing agent: Takenate A-52 (including 55% by mass of urethane resin curing agent, 45% by mass of ethyl acetate)
Solvent: Ethyl acetate These were blended at A-525: A-52: ethyl acetate = 9: 1: 165 (solid content concentration 3% by mass).

The gas barrier film layer was prepared by the following procedure.
[Coating liquid 2]:
(A) Solid content hydrolyzed by adding 72.1 g of 0.1N hydrochloric acid to 17.9 g of tetraethoxysilane (Si (OC ₂ H ₅ ) ₄ ; hereinafter abbreviated as TEOS) and 10 g of methanol and stirring for 30 minutes. Hydrolyzed solution of 5% ( _{converted to SiO 2 by weight).}

(B) A 5% (weight ratio) solution of polyvinyl alcohol (PVA), water / methanol = 95/5 (weight ratio).

The (c) 1,3,5-tris (3-trimethoxysilylpropyl) isocyanurate were prepared 5% solids with water / isopropyl alcohol = 1/1 solution (weight ratio ^R 2 Si _{(OH) 3} conversion) Hydrolyzed solution.

The blending ratios of the above solutions (a) to (c) were mixed so that liquid a / liquid b / liquid c = 70/20/10 (solid content weight ratio) to obtain [Coating liquid 2].

Using a gravure coating machine, the coating liquid 1 is coated on the corona-treated surface side of the high-density polyethylene film by a gravure roll coating method at a tension of 70 N / m and a drying temperature of 60 ° C. to obtain a polyurethane resin of 0. It was cured with a coating amount of 1 g / m ^2.

Next, aluminum was evaporated as a vapor deposition layer by an electron beam vacuum deposition method while introducing oxygen to form an AlOx vapor deposition film having a thickness of 10 nm. Next, the coating liquid 2 was sequentially coated under the conditions of a tension of 60 N / m and a drying temperature of 70 ° C.

As a result, a transparent gas barrier laminate composed of an adhesion layer (0.1 g / m ² ) / AlOx layer (10 nm) / gas barrier film layer (0.3 g / m ^{2) was obtained.}

The obtained barrier film had an oxygen permeability of 0.7 cc / m ² · day · MPa and a steam permeability of 4.5 g / m ² · day regardless of the density and thickness of the high-density polyethylene film.

Next, a linear low-density polyethylene film having a density of 0.915 g / cm ³ and a thickness of 130 μm was used as the sealant layer and laminated by a non-sol laminating method. ADN-369AF: ADN-369B = 3: 1 (manufactured by Toyo Morton Co., Ltd.) was used as the adhesive, and the coating amount was 1.8 g / m ² (wet). A laminate was obtained by the above steps.

Next, a spout and a cap made of high-density polyethylene having the density and MFR shown in Table 1 were prepared by injection molding.

The laminate and the spout were heat-sealed at the heat-sealing temperatures shown in Table 1 with a sealing pressure of 0.2 MPa and a sealing time of 0.3 seconds, and the heat-sealing strength was measured. The results are shown in Table 1. The heat seal strength was measured under the condition of 90 ° peeling at a tensile speed of 300 mm / min with the test piece having a width of 15 mm.

In addition, a standing pouch with a spout having a length of 235 mm and a width of 130 mm was produced by using the spout and the laminate. In the pressure resistance test, the prepared standing pouch with a spout was filled with 130 mL of water at room temperature, and a load of 80 kg was applied to hold the pouch for 1 minute, and the number of broken bags was counted.

In addition, after filling 130 mL of water in a standing pouch with a spout of the same size and storing it at 5 ° C for 24 hours, the bottom of the standing pouch with a spout is facing down from a height of 1.2 m against the concrete floor. The drop test was performed by dropping three times, then dropping the standing pouch with a spout face down three times, and counting the number of broken bags.

The pressure resistance test was carried out with 5 bags and the drop test was carried out with 25 bags, and the results are shown in Table 1 as the number of broken bags / the number of bags carried out.

From the results shown in Table 1, in Comparative Example 1, the range in which the heat seal strength is stable is narrow and the bag making suitability is low, whereas in Examples 1 and 2, the heat seal strength is stable and bag making is possible. It can be seen that the aptitude is wide.

Claims (1)

A standing pouch consisting of two side wall laminates and one folded bottom laminate with a sealed peripheral edge, with a spout and cap on the upper side of the pouch body. A standing pouch in which the side wall laminate and the bottom laminate are
At least a barrier film layer, an adhesive layer, and a sealant layer are laminated in this order, and the barrier film layer is a film having a thickness of 20 to 40 μm made of high-density polyethylene ^{having a density of 0.940 to 0.980 g / cm 3.} And the barrier layer formed on the film, and the sealant layer is made of a ^{linear low-density polyethylene having a density of 0.910 to 0.920 g / cm 3} and having a thickness of 100 to 150 μm.
A standing pouch with a spout, wherein the spout is made of high-density polyethylene having a density of 0.96 g / cm ^{3 or less and an MFR of 5 g / 10 min or more.}