Dropping container

Abstract

The present invention provides a dropping container in which interlayer delamination can be suppressed. More specifically, the present invention relates to a dropping container 10 comprising an accommodating part 11 for accommodating a solution to be dropped and an orifice part 12 protruding from the accommodating part 11. The accommodating part 11 and the orifice part 12 are formed from a multilayer structure 20 having an interface 23 between the layers of an inner layer 21 containing a cyclic olefin resin on the side where the contents are accommodated and an outer layer 22 containing a polyethylene resin located farther outward than the inner layer 21. The polyethylene resin contained in the outer layer 22 is low-density polyethylene (LDPE) with a weight-average molecular weight (Mw) of less than 90,000.

Description

Dropping container

[0001] The present invention relates to a drip container.

[0002] Conventionally, various resin containers have been widely used as drip containers for containing eye drops, such as eye drop containers. For example, Patent Document 1 describes a drip container having a container portion for containing eye drops, the container portion being made of a multi-layered resin layer.

[0003] Japanese Patent Application Publication No. 2024-40201

[0004] Depending on the environmental temperature and the time that has passed during storage or transportation of the dropping container, delamination may occur in the resin layers of the multi-layer structure, resulting in defects such as abnormal appearance and contamination with foreign matter.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a dripping container that can suppress interlayer delamination.

[0006] To solve the above problems, the present invention has the following configurations. [1] A dropping container having a storage section for storing a medicinal solution to be dropped and a mouth section protruding from the storage section, wherein the storage section and the mouth section have a multilayer structure having an interface between an inner layer containing a cyclic olefin resin on the side where the contents are stored and an outer layer containing a polyethylene resin outside the inner layer, the polyethylene resin contained in the outer layer being low-density polyethylene (LDPE) having a weight-average molecular weight (Mw) of less than 90,000. [2] In [1], the interface between the inner layer and the outer layer is exposed at an end of the mouth section. [3] In [1] or [2], the dropping container further has a nozzle section for dropping the medicinal solution stored in the storage section. [4] In [3], the nozzle section is attached as a separate member from the mouth section. [5] In any one of [1] to [4], the medicinal solution is selected from eye drops, nasal drops, ear drops, control solution, and calibration solution.

[0007] According to the present invention, delamination can be suppressed in a drip container having a multi-layer structure.

[0008] 1 is a cross-sectional view illustrating a multi-layer structure of a dripping container;

[0009] The present invention will be described below based on preferred embodiments. Fig. 1 is an external view showing an example of a dripping container. Fig. 2 is a cross-sectional view illustrating the multi-layer structure of the dripping container.

[0010] As shown in FIG. 1 , a dripping container 10 of this embodiment has a container 11 for containing a chemical solution to be dripped, and a mouth 12 protruding from the container 11 .

[0011] As shown in Figure 2, the storage section 11 and the opening section 12 have a multilayer structure 20 having an interface 23 between an inner layer 21 containing a cyclic olefin resin on the side where the contents are stored and an outer layer 22 containing a polyethylene resin outside the inner layer 21.

[0012] Furthermore, the polyethylene resin contained in the outer layer 22 is a low-density polyethylene (LDPE) having a weight-average molecular weight (Mw) of less than 90,000. When the outer layer 22 contains a low-density polyethylene (LDPE) having a weight-average molecular weight (Mw) of less than 90,000, delamination at the interface 23 between the inner layer 21 and the outer layer 22 of the multilayer structure 20 can be suppressed.

[0013] The resin component constituting the outer layer 22 is preferably only low-density polyethylene (LDPE) having a weight-average molecular weight (Mw) of less than 90,000, but other resin components may also be blended within a range that does not impair the effects of the present invention. The proportion of low-density polyethylene (LDPE) having a weight-average molecular weight (Mw) of less than 90,000 in the outer layer 22 is, for example, preferably 80 to 100 wt %, and more preferably 90 to 100 wt %, based on the total weight of the outer layer 22.

[0014] Examples of other resins that can be blended into the outer layer 22 include polyolefin resins such as polyethylene resins and thermoplastic elastomers such as styrene-based elastomers. The outer layer 22 may be a layer containing a polyethylene-based resin and a cyclic olefin-based resin, or may be a polyethylene-based resin layer that does not contain a cyclic olefin-based resin.

[0015] The smaller the weight-average molecular weight (Mw) of the polyethylene resin contained in the outer layer 22, the higher the film adhesion strength with the cyclic olefin resin, and the more effectively it can suppress delamination at the interface 23 between the inner layer 21 and the outer layer 22. The weight-average molecular weight (Mw) of the polyethylene resin is preferably less than 90,000. Furthermore, the z-average molecular weight (Mz) of the polyethylene resin is preferably less than 300,000.

[0016] The higher the melting point of the polyethylene resin contained in the outer layer 22, the higher the film adhesion strength with the cyclic olefin resin, and the more effectively it can suppress delamination at the interface 23 between the inner layer 21 and the outer layer 22. The melting point of the polyethylene resin is preferably 109°C or higher. In addition, the melting point of low-density polyethylene (LDPE) having a weight-average molecular weight (Mw) of less than 90,000 is preferably 109°C or higher.

[0017] The thickness of the outer layer 22 is not particularly limited, but is preferably in the range of 150 to 1400 μm, and more preferably in the range of 200 to 1000 μm. The outer layer 22 may further have an outer surface that can come into contact with the outside air as the outermost layer of the multilayer structure 20. In other words, the multilayer structure 20 may have another layer outside the outer layer 22.

[0018] The inner layer 21 contains a cyclic olefin resin as a resin with excellent non-sorption (non-adsorption) and moisture-proof properties. Examples of the cyclic olefin resin include so-called COP (copolymer of cyclic olefins), COC (copolymer of cyclic olefin and acyclic olefin), and cyclic olefin homopolymer.

[0019] The multilayer structure 20 contains a cyclic olefin resin at least in the inner layer 21 of the container 11 or the mouth 12, thereby suppressing sorption and evaporation of the contents such as a medicinal solution, etc. This improves the non-sorption (non-adsorption) and moisture-proof properties of the dripping container 10.

[0020] The resin component constituting the inner layer 21 may be a cyclic olefin resin alone, or a mixture of a cyclic olefin resin with other resins. The inner layer 21 may contain two or more types of cyclic olefin resins. The proportion of the cyclic olefin resin in the inner layer 21 is preferably, for example, 50 to 100% by weight based on the total weight of the inner layer 21. Examples of other resins that can be blended into the inner layer 21 include polyolefin resins such as polyethylene resins and thermoplastic elastomers such as styrene-based elastomers. The inner layer 21 may be a layer containing a cyclic olefin resin and a polyethylene-based resin, or it may be a cyclic olefin-based resin layer that does not contain a polyethylene-based resin.

[0021] The thickness of the inner layer 21 is not particularly limited, but is preferably in the range of 50 to 1000 μm, and more preferably in the range of 100 to 400 μm. The inner layer 21 may further have an inner surface that can come into contact with the drug solution as the innermost layer of the multilayer structure 20. That is, the multilayer structure 20 may have another layer outside the inner layer 21. An example of another layer outside the inner layer 21 is a resin layer containing a polyethylene-based resin.

[0022] The cyclic olefin used as a constituent monomer of the cyclic olefin resin contained in the multilayer structure 20 is an unsaturated hydrocarbon (olefin) having at least one ring structure, such as at least one of vinylcycloalkanes having a cycloalkane of 3 to 20 carbon atoms and derivatives thereof, monocycloalkenes having 3 to 20 carbon atoms and derivatives thereof, and cyclic olefins having a norbornene skeleton (norbornene-based monomers).

[0023] Examples of norbornene-based monomers include bicyclo[2.2.1]-2-heptene (norbornene) and its derivatives. Examples of norbornene derivatives include compounds having a substituent such as an alkyl group, such as alkylnorbornenes, compounds having two or more unsaturated bonds, such as norbornadiene, and compounds having three or more ring structures, two of which constitute a norbornene skeleton.

[0024] Examples of norbornene-based monomers having three or more ring structures include tricyclo[5.2.1.0 ２，６]decene (dihydrodicyclopentadiene), compounds in which one or more molecules of cyclopentadiene are added to norbornene or dihydrodicyclopentadiene by Diels-Alder reaction (e.g., tetracyclododecene, pentacyclopentadecene, hexacycloheptadecene, etc.), hydrogenated products thereof, isomers with different double bond positions, alkyl-substituted products, etc.

[0025] The COP may be a copolymer of two or more cyclic olefins or a hydrogenated product thereof. The COP is preferably an amorphous polymer, and may be a ring-opening polymer of a cyclic olefin obtained by metathesis or the like, or a hydrogenated product thereof.

[0026] The COC may be a copolymer of at least one cyclic olefin and at least one acyclic olefin, or a hydrogenated product thereof. The COC is preferably an amorphous polymer, and may be a copolymer of a cyclic olefin and ethylene, or a hydrogenated product thereof.

[0027] In the COC, examples of the acyclic olefin copolymerized with the cyclic olefin include α-olefins such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, and 1-octene, and alkenes such as 3-decene and 3-dodecene.

[0028] The inner layer 21 and outer layer 22 of the multilayer structure 20 can be integrally formed between the storage portion 11 and the mouth portion 12. The dripping container 10 is open at an end 13 of the mouth portion 12. The storage portion 11 has a storage space 14 for storing the medicinal solution to be dripped. A portion whose shape changes continuously, such as a reduced diameter portion 15, may be provided between the storage portion 11 and the mouth portion 12.

[0029] Examples of molding methods for the drip container 10 include multilayer blow molding, multilayer injection molding, and multilayer inflation molding. More specifically, multilayer blow molding includes direct blow molding and injection blow molding. In blow molding, air is blown into the interior of a parison and pressed against the inner surface of a mold, thereby molding the drip container 10 including the container portion 11 and the mouth portion 12. When excess material from the mouth portion 12 is removed by deburring, the mouth portion 12 opens.

[0030] The inner layer 21 is laminated at least from the inner surface of the storage portion 11 to the inner surface of the mouth portion 12. When the inner layer 21 is laminated from the inner surface of the storage portion 11 to the end portion 13 of the mouth portion 12, the inner layer 21 may be exposed at the end portion 13 of the mouth portion 12, as shown in Fig. 2. The interface 23 between the inner layer 21 and the outer layer 22 may also be exposed at the inner surface of the mouth portion 12, the end portion 13, or the vicinity thereof. If a portion of the inner layer 21 is peeled off from the outer layer 22 at the inner surface of the mouth portion 12, the end portion 13, or the like due to delamination at the interface 23, defects such as abnormal appearance and contamination with foreign matter may occur.

[0031] The storage conditions of the dripping container 10 may include, for example, when the empty container is transported by automobile, train, or ship, where it may be subjected to physical effects such as high temperature and external forces such as vibration. For example, when the temperature reaches a high temperature of about 60°C, there is a possibility that distortion will occur at the interface 23 due to differences in physical properties such as the thermal expansion coefficient between the resin of the inner layer 21 and the resin of the outer layer 22. Furthermore, there is a possibility that the dripping container 10 may come into contact with an adjacent dripping container 10 due to vibration.

[0032] As described above, by laminating the outer layer 22 containing low-density polyethylene (LDPE) having a weight-average molecular weight (Mw) of less than 90,000 onto the inner layer 21 containing a cyclic olefin resin, it is possible to suppress delamination at the interface 23. For example, even if the dripping container 10 is subjected to external influences such as high temperature and vibration, it is possible to prevent abnormal appearance and inclusion of foreign matter.

[0033] The multilayer structure 20 of the dropping container 10 may have one or more layers other than the inner layer 21 and the outer layer 22, such as a reinforcing layer, a gas barrier layer, an ultraviolet absorbing layer, an oxygen absorbing layer, and a printed layer. When molding the multilayer structure 20, it is preferable to adopt a combination of the inner layer 21 and the outer layer 22 that has excellent adhesion to each other. Additives such as ultraviolet absorbers, oxygen absorbers, colorants, and stabilizers can also be added to the resin. The inner layer 21 can also be designed without using additives. Additives may be added to the outer layer 22.

[0034] After molding the container 11 and the mouth 12, which include the inner layer 21 and the outer layer 22, other layers, such as a printed layer, may be added to the outside of the outer layer 22. The thickness of the multilayer structure 20 is preferably in the range of 300 to 2000 μm, for example. Depending on the position in the container 11 or the mouth 12, the multilayer structure 20 may include thicker or thinner portions than those illustrated.

[0035] The mouth portion 12 may further have a nozzle portion 31 for dripping the medicinal liquid contained in the storage portion 11. For example, the dripping container 10 may be configured as a package 30 equipped with the dripping nozzle portion 31, a cap 32, etc., as separate members from the storage portion 11 including the inner layer 21 and the outer layer 22 and the mouth portion 12. The package 30 is a dripping container that can contain the medicinal liquid to be dripped and store it in a sealed state.

[0036] The nozzle 31 is not particularly limited, but may be an inner plug or the like that can be attached to the mouth 12. The attachment structure of the cap 32 is also not particularly limited, but threads (not shown) may be provided on the outer surface of the mouth 12 and the inner surface of the cap 32. The threads of the mouth 12 can be molded integrally with the dripping container 10.

[0037] While the present invention has been described above based on preferred embodiments, the present invention is not limited to the above-described embodiments and various modifications are possible without departing from the spirit of the present invention. Modifications include addition, substitution, omission, and other changes to components in each embodiment.

[0038] The medicinal liquids to be stored in the storage section of the drip container having the multilayer structure 20 of this embodiment include liquids such as eye drops, nasal drops, ear drops, control liquids for in vitro diagnostic reagents, calibration liquids, etc., and include pharmaceuticals that are used by dripping from the drip container.

[0039] The present invention will be specifically described below with reference to examples.

[0040] <Molding of Dropping Container> A multilayered dropping container having an interface between an inner layer and an outer layer was molded by blow molding. The resulting dropping container had a structure in which the interface between the inner layer and the outer layer was exposed at the end of the mouth protruding from the container portion.

[0041] The resin used for the inner layer was a cyclic olefin resin (ZEONEX (registered trademark) 5000, manufactured by Zeon Corporation). This cyclic olefin resin was a COP (copolymer of different cyclic olefins).

[0042] The resin used for the outer layer was a polyethylene-based resin shown in Table 1. The physical properties of the resin for the outer layer are shown as melting point, density, number average molecular weight (Mn), weight average molecular weight (Mw), z-average molecular weight (Mz), and melt flow rate (MFR). The abbreviations for the resins in Table 1 represent the following resin grades.

[0043] LDPE-1: Low-density polyethylene (manufactured by Tosoh Corporation, Petrothene (registered trademark) 175K) LDPE-2: Low-density polyethylene (manufactured by Tosoh Corporation, Petrothene (registered trademark) 220K) LDPE-3: Low-density polyethylene (manufactured by Ube Maruzen Polyethylene Co., Ltd., F120N) LDPE-4: Low-density polyethylene (manufactured by Tosoh Corporation, Petrothene (registered trademark) 170K)

[0044] <Measurement of Film Adhesion Strength> A sample for measuring the film adhesion strength between the inner layer and the outer layer was cut out from the prepared dropping container, and the film adhesion strength (N / 15 mm) was measured as an integrated average load for the number of samples N=5.

[0045] <Measurement of the number of curled-up end portions and the distance of curled-up end portions> After storing the dropping containers in an environment of 60°C for 16 days, it was confirmed whether curling-up due to delamination occurred at the edge of the mouth. More specifically, the number of curled-up end portions and the distance of curled-up end portions (µm) were measured for 10 samples.

[0046] <Measurement of Thickness of Multilayer Structure> A sample for measuring the thickness of the multilayer structure was cut out from the center of the dropping container, and the thickness of the outer layer, the thickness of the inner layer, and the total thickness (μm) of the multilayer structure were measured.

[0047] The results are shown in Table 1.

[0048]

[0049] According to the examples, a dropping container was obtained that was free from curling at the end of the mouth and was excellent in productivity and reliability.

[0050] 10...Drip container, 11...Storage section, 12...Mouth section, 13...End of mouth section, 14...Storage space, 15...Narrowed diameter section, 20...Multilayer structure, 21...Inner layer, 22...Outer layer, 23...Interface, 30...Packaging body, 31...Nozzle section, 32...Cap

Claims

A dripping container having a container portion for containing a medicinal liquid to be dripped and a mouth portion protruding from the container portion, the storage section and the mouth section have a multilayer structure having an interface between an inner layer containing a cyclic olefin resin on the side where the contents are stored and an outer layer containing a polyethylene resin on the outer side of the inner layer, A dropping container, wherein the polyethylene resin contained in the outer layer is a low-density polyethylene (LDPE) having a weight-average molecular weight (Mw) of less than 90,000.

2. The dripping container according to claim 1, wherein the interface between the inner layer and the outer layer is exposed at an end of the mouth portion.

3. The dripping container according to claim 1, further comprising a nozzle portion for dripping the chemical solution contained in the container portion.

4. The dripping container according to claim 3, wherein the nozzle portion is attached as a separate member from the mouth portion.

5. The dropping container according to claim 1, wherein the medicinal liquid is any one selected from the group consisting of eye drops, nasal drops, ear drops, control liquid, and calibration liquid.

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