JP2004244044A - Multi-layer pouring member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multi-layer pouring member related to a pouring member integrally mounted on such a container as a pouch and a transfusion bag which can prevent oxygen from transmitting through a wall of the pouring member when it is mounted on the container such as the pouch and the transfusion bag, and in particular, can prevent gas barrier properties from being suddenly decreased when a severe retort sterilization treatment is performed. <P>SOLUTION: The pouring member integrally mounted on the container is a multi-layer pouring member 1 in which an intermediate layer is an oxygen absorbing gas barrier layer. It is preferable that oxygen transmission factor of the gas barrier resin of the oxygen absorbing gas barrier layer is ≤5.5×10<SP>-12</SP>(cc cm)/(cm<SP>2</SP>sec cmHg)(23°C, 0%RH), and the oxygen absorbing gas barrier layer 5 comprises an oxidative polymer and a transition metal catalyst. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a pouring member integrally attached to a container such as a pouch and an infusion bag, and more specifically, to an oxygen-absorbing property and a gas-barrier property of oxygen and the like which are integrally attached to an opening of the container. It relates to an excellent multilayer pouring member.
[0002]
[Prior art]
Conventionally, oxygen permeation through the container wall is zero in metal cans and glass bottles, and only oxygen remaining in the container poses a problem.However, in the case of plastic containers, oxygen permeation through the container wall cannot be ignored. This causes problems in preserving the contents.
[0003]
Therefore, among various plastic containers, in containers such as pouches and infusion bags, a multilayer film having a metal foil such as an aluminum foil, a tin foil, or an iron foil in order to prevent deterioration and flavor reduction due to oxygen passing through the container wall. The use of a multilayer film provided with a resin layer having resistance to gas permeation of oxygen or the like such as polyamide or ethylene-vinyl alcohol copolymer has been performed.
[0004]
Further, as a method for removing oxygen in the container, a layer in which an oxygen permeable resin is mixed with a deoxidizer containing a reducing substance such as iron powder as a main component and a layer having an oxygen gas barrier property are laminated (patented). A packaging film containing an oxygen scavenger comprising a substituted or unsubstituted ethylenically unsaturated hydrocarbon and a transition metal catalyst has been proposed (see Patent Document 2).
[0005]
On the other hand, in order to pour out the contents from containers such as pouches for beverages and bags for infusions, containers in which a pouring member is integrally attached to an opening of the container are widely used.
In these pouring members, a gas barrier layer made of an ethylene-vinyl alcohol copolymer, polyamide or the like is used as an intermediate layer in order to prevent entry of gas such as oxygen from the pouring member and prevent deterioration of contents. Has been proposed (see Patent Document 3). Further, the present applicant has proposed a combination of a multilayer injection member having a gas barrier layer formed thereon and an oxygen absorbing layer as another layer. A possible multi-layer pouring member was also proposed. (See Patent Documents 4 and 5)
[0006]
[Patent Document 1]
Japanese Patent Publication No. 62-1824 [Patent Document 2]
Japanese Patent No. 3183704 [Patent Document 3]
JP-A-11-128317 [Patent Document 4]
JP 2002-21594 A [Patent Document 5]
JP, 2002-255200, A
[Problems to be solved by the invention]
As described above, a container made of a metal foil or a multilayer film using a resin layer having gas permeability resistance such as polyamide or ethylene-vinyl alcohol copolymer has excellent gas barrier properties, and also has a reduction in iron powder and the like. A layer containing an oxygen scavenger containing a reactive substance as a main component and a layer having oxygen gas barrier properties, or a layer comprising a substituted or unsubstituted ethylenically unsaturated hydrocarbon and an oxygen scavenger comprising a transition metal catalyst. The container comprising the multilayer film has excellent oxygen removal in the container.
[0008]
However, in the case where a pouch made of these multilayer films, an opening of a container such as an infusion bag or the like is provided with a discharging member for discharging the contents, oxygen permeation through the wall of the discharging member cannot be ignored. A multi-layer pouring member in which a gas barrier layer made of a resin such as ethylene-vinyl alcohol or polyamide is formed as an intermediate layer of the pouring member has been proposed. When the resin constituting the gas barrier layer is subjected to severe retort sterilization treatment, the gas barrier property is sharply reduced.
[0009]
Further, the multilayer pouring member in which the gas barrier layer and the oxygen absorbing layer are combined as another layer has a gas barrier property of oxygen or the like and an oxygen absorbing property, but the gas barrier layer and the oxygen absorbing layer are separately provided. Therefore, the number of layers exhibiting oxygen barrier properties increases, the thickness of the wall of the pouring member also increases, and it is difficult to control the thickness of each layer, which is not preferable in terms of production cost and the like.
[0010]
[Means for Solving the Problems]
According to the present invention, there is provided a multi-layer pouring member in which the intermediate layer is an oxygen-absorbing gas barrier layer, which is a pouring member integrally attached to the container.
In the present invention,
1. An oxygen permeability coefficient of the gas barrier resin of the gas barrier layer is 5.5 × 10 ⁻¹² cc · cm / cm ² · sec · cmHg (23 ° C., 0% RH) or less;
2. The oxygen-absorbing gas barrier layer contains an oxidizing polymer and a transition metal catalyst,
3. 3. The oxidizing polymer has an average dispersed particle diameter of 1 μm or less, and an area ratio of dispersed particles in a cross section in the thickness direction of the gas barrier layer is 1% or more. The oxidizable polymer is a polyene-based polymer,
5. The oxidizable polymer is modified with an acid or an acid anhydride,
6. The oxidizing polymer of the oxygen-absorbing barrier layer contains 1 to 20% by weight, and the transition metal catalyst contains 100 ppm to 1000 ppm;
Is preferred.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention is characterized in that the pouring member is integrally attached to the container, and the intermediate layer is an oxygen-absorbing gas barrier layer.
[0012]
[Oxygen absorbing gas barrier layer (intermediate layer)]
1. Gas barrier resin The most preferred gas barrier resin is ethylene-vinyl alcohol having a vinyl alcohol unit content of 40 to 85 mol%, particularly 50 to 80 mol%, and a saponification degree of 96% or more, particularly 99%. And copolymers.
Other gas barrier resins include nylon resins, especially nylon 6, nylon 8, nylon 11, nylon 12, nylon 6,6, nylon 6,10, nylon 10,6, and nylon 6 / 6,6. Examples thereof include aliphatic nylon such as coalesce, partially aromatic nylon such as polymethaxylylene adipamide, and polyglycolic acid resin.
These gas-barrier resins have an oxygen permeability coefficient of 5.5 × 10 ⁻¹² cc · cm / cm ² · sec · cmHg (23 ° C., 0% RH) or less.
The thickness of the gas barrier layer is preferably 5 to 300 μm, particularly preferably 10 to 100 μm.
[0013]
Further, the gas barrier layer in the multi-layer pouring member of the present invention is preferably made of a gas barrier resin containing an oxidizing polymer and a transition metal catalyst in order to obtain a higher content preservation property. In this case, since the gas barrier resin is present as a continuous phase (matrix) and the oxidizing polymer is present as a dispersed phase, the surface area of the oxidizing polymer in the dispersed phase is increased, and oxygen is efficiently absorbed. . At the same time, even when the oxidation of the dispersed phase proceeds, excellent gas barrier properties and mechanical strength are maintained by the gas barrier resin remaining as a continuous phase.
[0014]
2. Oxygen-absorbing composition As the oxygen-absorbing composition, an oxidizing polymer is preferable, among which a polyene-based polymer is preferable, and an oligomer or polymer containing a unit derived from a conjugated diene having 4 to 20 carbon atoms is suitably used. Is done. As these monomers, for example, conjugated dienes such as butadiene and isoprene are suitable.
Specific examples of the polyene-based polymer include, but are not limited to, polybutadiene, polyisoprene, butyl rubber, natural rubber, nitrile-butadiene rubber, styrene-butadiene rubber, chloroprene rubber, ethylene-propylene-rubber, and the like. .
[0015]
In the multilayer pouring member of the present invention, the carbon-carbon double bond of the polyene-based polymer used for the gas barrier layer is not particularly limited, and may be present in the main chain in the form of a vinylene group, or may be vinyl. It may be present on the side chain in the form of a group, and it is essential that it be oxidizable, but a vinyl group is preferred because it has a high oxidation rate.
[0016]
The polyene polymer is preferably modified with a carboxylic acid group, a carboxylic anhydride group or the like, and as a monomer used for introducing these functional groups, ethylene having the above functional group is used. And unsaturated monomers.
[0017]
As these monomers, it is preferable to use unsaturated carboxylic acids or derivatives thereof.Specifically, acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, etc. unsaturated carboxylic acids such as α, β-unsaturated carboxylic acid, bicyclo [2,2,1] hept-2-ene-5,6-dicarboxylic acid, maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydroanhydride Unsaturated carboxylic acid anhydrides such as α, β unsaturated carboxylic acid anhydrides such as phthalic acid and bicyclo [2,2,1] hept-2-ene-5,6-dicarboxylic acid anhydrides are exemplified.
[0018]
The acid modification of the polyene polymer is produced by graft copolymerizing an unsaturated carboxylic acid or a derivative thereof by a means known per se.
[0019]
Particularly preferred polyene-based polymers preferably contain an unsaturated carboxylic acid or a derivative thereof in an amount such that the acid value becomes 5 mg / g or more.
When the content of the unsaturated carboxylic acid or a derivative thereof is in the above range, the dispersion of the acid-modified polyene-based polymer in the oxygen-barrier thermoplastic resin is improved, and the oxygen is smoothly absorbed. .
[0020]
The polyene-based polymer is preferably a liquid resin in a state of being modified with an acid or an acid anhydride, from the viewpoint of dispersibility in an oxygen-barrier thermoplastic resin.
[0021]
In the present invention, the oxidizing polymer is blended so that the average dispersed particle diameter is 1 μm or less and the area ratio of the dispersed particles in the cross section in the thickness direction of the gas barrier layer is 1% or more. Is preferable in terms of oxygen absorption, moldability, appearance, thickness uniformity and smoothness.
[0022]
[Area dispersion average particle size]
The area method average dispersed particle diameter can be determined by the following method.
The multi-layer injection member was cut into a ring shape, and the cut surface was polished and embedded in an epoxy / amine-based embedding resin for an electron microscope, the embedding resin was cured, and the cross section of the gas barrier layer was oxidized. By using a dye capable of selectively dyeing only the union, an oxidizing polymer (oxygen-absorbing resin) contained as a dispersed phase can be identified.
Scanning electron microscope (SEM) photographs were taken of the cross section of the dyed gas barrier layer, the images of the SEM photographs were captured by a scanner, and the oxidizable polymer and other parts were imaged on a personal computer screen by image processing software. identify and measure the area S and the dispersion particle number n of dispersed particles of the oxidizing polymer present in a given area S _0. This operation is performed for a plurality of visual fields in order to improve the accuracy, ΣS and Σn are calculated from S and n obtained for each of the visual fields, and the area method average dispersed particle diameter d is obtained from the following equation (1).
d = (ΣS / Σn) ^1/2 (1)
Also, the S ₀ and S determined for a plurality of field, obtaining the α area ratio of the dispersed particles by the following equation (2).
α = 100 × ΣS / ΣS ₀ (2)
[0023]
3. Transition metal catalyst As the transition metal catalyst, iron, cobalt, nickel and the like are preferable, but other metal components such as copper, silver, tin, titanium, zirconium, vanadium, chromium and manganese can be mentioned. Among these metal components, the cobalt component is particularly preferable because of its high oxygen absorption rate.
[0024]
Transition metal catalysts are generally used in the form of inorganic or organic acid salts of the transition metals.
Examples of the inorganic acid salts include halides such as chlorides, sulfur oxyacid salts such as sulfates, nitrogen oxyacid salts such as nitrates, phosphorus oxyacid salts such as phosphates, and silicates.
On the other hand, examples of the organic acid salt include carboxylate, sulfonate, phosphonate and the like, and carboxylate is particularly preferable. Specific examples thereof include acetic acid, propionic acid, isopropionic acid, and butane. Acid, isobutanoic acid, pentanoic acid, isopentanoic acid, hexanoic acid, heptanoic acid, isoheptanoic acid, octanoic acid 2-ethylhexanoic acid, nonanoic acid, 3,5,5-trimethylhexanoic acid, decanoic acid, neodecanoic acid, undecanoic acid, Lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, arachidic acid, lindelic acid, tunic acid, petroselinic acid, oleic acid, linoleic acid, linolenic acid, arachidonic acid, formic acid, succinic acid, sulfamic acid, naphthenic acid And the like.
[0025]
The content of the oxidizing polymer to be blended in the gas barrier layer is preferably 1 to 20% by weight, and the content of the transition metal catalyst is 100 to 100% as the transition metal with respect to the gas barrier resin and the oxidizing polymer. 1000 ppm, especially 200 to 500 ppm, is preferred.
[0026]
If the amount of the oxidizing polymer is less than 1% by weight, the oxygen absorbing effect becomes insufficient, and if it exceeds 20% by weight, the mechanical properties of the oxygen absorbing barrier material are deteriorated.
If the amount of the transition metal catalyst is less than 100 ppm, the induction period until the high barrier property is developed is long. Even if the amount exceeds 1000 ppm, there is no particular improvement in the oxygen absorption performance. Is a problem.
[0027]
In the gas barrier layer of the present invention, known fillers, colorants, heat stabilizers, weather stabilizers, antioxidants, antioxidants, light stabilizers, ultraviolet absorbers, antistatic agents, metal soaps, A lubricant such as wax and a resin compounding agent such as a modifying resin or rubber can be contained.
[0028]
4. [Inner and outer layers]
For the inner and outer layers of the multilayer pouring member of the present invention, it is preferable to select an olefin resin, and low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE) ), Polyethylene (PE) such as linear very low density polyethylene (LVLDPE), polypropylene (PP), ethylene-propylene copolymer, polybutene-1, ethylene-butene-1 copolymer, propylene-butene-1 copolymer Examples thereof include a copolymer, an ethylene-propylene-butene-1 copolymer, an ethylene-vinyl acetate copolymer (EVA), an ion-crosslinked olefin copolymer (ionomer), and a blend thereof.
[0029]
5. [Moisture resistant layer composed of cyclic olefin copolymer resin]
In the multilayer pouring member of the present invention, a moisture-resistant layer against water vapor or the like may be provided at least between the oxygen-absorbing gas barrier layer (intermediate layer) and the inner layer, and the cyclic olefin copolymer resin constituting the layer is A non-crystalline or low-crystalline copolymer of an olefin and a cyclic olefin, wherein ethylene is preferred as the olefin, and propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, Α-olefins having 3 to 20 carbon atoms, such as -methyl 1-pentene and 1-decene, are used alone or in combination with ethylene.
As the cyclic olefin, basically, an alicyclic hydrocarbon compound having an ethylenically unsaturated bond and a bicyclo ring, particularly, bicyclo [2.2.1] hept-2-ene, tetracyclo [4,4,0,1 ^{2,5, 1} 7,10] -3-dodecene and the like are preferable, can also be used those described, for example, in JP-a 3-726 and JP-Hei 2-196832 Patent Publication.
Particularly, an ethylene-cyclic olefin copolymer is preferable, but the content of the cyclic olefin in the ethylene-cyclic olefin copolymer is preferably 10 to 50 mol%, particularly preferably 15 to 45 mol%. By providing the layer made of the ethylene-cyclic olefin copolymer, the moisture resistance and the fragrance retention of the contents are remarkably improved.
[0030]
[Multilayer pouring members]
Next, the multilayer pouring member of the present invention will be described with reference to the drawings, but the form is not limited thereto.
The multi-layer pouring member 1 of the present invention shown in FIG. 1 includes a cylindrical pouring portion 2 and a sealing portion 3. The pouring portion 2 is fitted into a through hole of the sealing portion 3, and the pouring portion 2 is connected. The multilayer structure has an inner layer 4, an oxygen-absorbing gas barrier layer 5, and an outer layer 6 made of a heat-sealing resin.
Although not shown, an adhesive layer made of an acid-modified olefin resin or the like may be provided between the inner layer 4 and the oxygen absorbing gas barrier layer 5 and between the oxygen absorbing gas barrier layer 5 and the outer layer 6, respectively.
[0031]
In the multilayer pouring member 1 of the present invention shown in FIG. 2, the cylindrical pouring portion 2 is a multilayer structure of an inner layer 4, an oxygen-absorbing gas barrier layer 5, and an outer layer 6 made of a heat-sealing resin. Also, an oxygen absorbing gas barrier layer 5 is provided.
Although not shown, the multi-layer pouring member 1 of the present invention may have a form in which the oxygen-absorbing gas barrier layer 5 is provided only in the seal portion 3.
By providing the oxygen-absorbing gas barrier layer 5 in the seal portion 3, when the device is mounted on the opening of a container such as a pouch or an infusion bag by heat sealing or the like, oxygen intrusion from the mounting portion is blocked, and the oxygen-absorbing gas is further reduced. Demonstrates barrier properties.
[0032]
The multilayer pouring member 10 of the present invention shown in FIG. 3 has a cylindrical pouring portion 2 and a sealing portion 3, and the pouring portion 2 and the sealing portion 3 are integrally formed. As shown in the figure, the injection part 2 has a multilayer structure of an inner layer 4, an oxygen-absorbing gas barrier layer 5, and an outer layer 6 made of a heat-sealable resin, as in the above-described multilayer injection member 1.
On both sides of the seal portion 3, wing pieces 11 whose thickness is increased from the upper end portion to the lower end portion and whose thickness is gradually reduced toward the side end portion are provided symmetrically. The connecting portion between the two has an inner curved surface shape.
By providing the wing pieces 11, when the multilayer pouring member 10 is fixed to the opening of the pouch P by heat sealing or the like, as shown in FIG. It is possible to prevent the occurrence of a slight gap that is likely to occur at the junction of the two.
In addition, as shown in the cross-sectional view of FIG. 5, in this multilayer pouring member 10, the circumferential length of the surface of any part in the height direction AA, BB, and CC of the seal portion 3. Are configured to have substantially the same length. With such a configuration, as shown in FIG. 6, when the plastic film constituting the pouch is fixed to the opening of the pouch by heat sealing or the like, The contact of the multilayer pouring member 10 with the seal portion 3 is smoothed, and wrinkles at the time of fixing are prevented.
[0033]
FIG. 7 is a reference cross-sectional view showing a state where the above-described multilayer pouring members 1 and 10 of the present invention are fixed in the opening of the pouch P by heat sealing.
The multi-layer pouring members 1 and 10 are arranged in the opening at the upper end of the pouch P, and are fixed by heat sealing between the plastic films when forming the heat seal portion H. The seal portion 3 is connected to the upper end of the pouch P It fits in the height direction of the heat seal portion H on the side, and it is possible to prevent oxygen permeation through the multilayer pouring member.
[0034]
The multilayer pouring member of the present invention includes various forms of pouches such as a three-sided seal, a four-sided seal flat pouch, a pillow pouch, a standing pouch, a gusset pouch, a multi-chamber pouch, an infusion solution, and an infusion bag for storing a solution such as a drug solution. Attached to the container.
[0035]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to the multilayer injection | pouring member of this invention, oxygen permeation through the injection | pouring member wall at the time of mounting to containers, such as a pouch and an infusion bag, is prevented, and especially the gas barrier property at the time of performing severe retort sterilization processing is sharp. Significant reduction is prevented.
[Brief description of the drawings]
FIG. 1 is a reference sectional view of a multilayer pouring member of the present invention.
FIG. 2 is a reference sectional view of another multilayer pouring member of the present invention.
FIG. 3 is a reference drawing of another multilayer pouring member of the present invention.
FIG. 4 is a reference sectional view of another multilayer pouring member of the present invention.
FIG. 5 is a cross-sectional view taken along line AA, BB, and CC in FIG. 3; FIG. 6 is a reference view showing a state in which the multilayer pouring member of the present invention is fixed to a pouch P; FIG. Reference cross-sectional view showing the state in which the pouring member is fixed to the pouch P [Description of reference numerals]
1, 10 Multi-layer pouring member 2 Inside pouring section 3 Seal section 4 Inner layer 5 Oxygen absorbing gas barrier layer 6 Outer layer 11 Wing piece

Claims (7)

A multi-layer pouring member, which is a pouring member integrally attached to a container, wherein the intermediate layer is an oxygen-absorbing gas barrier layer. The gas barrier resin of the oxygen-absorbing gas barrier layer has an oxygen permeability coefficient of 5.5 × 10 ⁻¹² cc · cm / cm ² · sec · cmHg (23 ° C., 0% RH) or less. Multi-layer pouring member. The multilayer pouring member according to claim 1 or 2, wherein the oxygen-absorbing gas barrier layer contains an oxidizing polymer and a transition metal catalyst. The multilayer pouring member according to claim 3, wherein the oxidizable polymer has an average dispersed particle diameter of 1 µm or less, and an area ratio of dispersed particles in a cross section in the thickness direction of the gas barrier layer is 1% or more. . The multilayer pouring member according to claim 3 or 4, wherein the oxidizable polymer is a polyene-based polymer. The multilayer pouring member according to any one of claims 3 to 5, wherein the oxidizable polymer is modified with an acid or an acid anhydride. 7. The multilayer pouring member according to claim 3, wherein the oxidizing polymer of the oxygen-absorbing barrier layer contains 1 to 20% by weight, and the transition metal catalyst contains 100 to 1000 ppm.

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