JP2024055002A - Liquid container - Google Patents

Abstract

[Problem] The objective is to provide a liquid medicine container, such as an eye drop container, that has squeezability (flexibility) and suppresses evaporation. [Solution] The liquid medicine container is made of a polymer composition containing 72% by weight or more of a cyclic polyolefin having hydrogenated aromatic vinyl polymer block units, which are hydrogenated products of polymer blocks consisting of aromatic vinyl monomer units, and hydrogenated conjugated diene polymer block units, which are hydrogenated products of polymer blocks consisting of conjugated diene monomer units, and is characterized in that the minimum thickness of the container is 0.08 mm or more, and the water vapor permeability after storage for three months at a temperature of 40°C and a relative humidity of 25% does not exceed a loss of 3.0% from the initial content. [Selected Figure] Figure 1

Description

The present invention relates to liquid containers such as eye drop containers.

Conventionally, a drug container for storing an ophthalmic composition such as an eye drop is composed of a plurality of components such as a container body, an inner plug, a nozzle, a cap, etc. As the solvent container, a container made of polyethylene or polypropylene may be used.
The components of this ophthalmic composition include menthol and other components that are easily adsorbed to resins such as polyethylene and polypropylene. Therefore, the ratio of the components in the ophthalmic composition changes during storage, which significantly affects the quality and feel of the composition when used.

In response to this, Patent Document 1 describes a method that uses a container made of polyethylene terephthalate resin or other resin with low adsorption properties.

JP 2020-059704 A

However, the resins used in Patent Document 1 are mostly crystalline resins and have low flexibility, so that it is difficult to say that the squeezability of pushing the ophthalmic composition out of the container when administering the composition to the eye is sufficient.
In response to this, it is conceivable to add a component that imparts flexibility to the crystalline resin to improve the squeezability of the container. The applicant of the present application has investigated this issue, but has found that increasing the amount of the component that imparts flexibility makes it easier for some of the components of the ophthalmic composition to evaporate from the container, which tends to cause changes in the component ratios of the ophthalmic composition.

Therefore, the present invention was made in consideration of such problems, and aims to provide a liquid container, such as an eye dropper, that has squeezability (flexibility) and suppresses evaporation.

As a result of extensive research, the inventors have found that the use of a specific cyclic polyolefin and a container with specific water vapor permeability results in excellent squeezability (flexibility) and inhibition of evaporation, and have arrived at the present invention.
That is, the present invention has the following features.

[1] A liquid container comprising a polymer composition containing 72% by weight or more of a cyclic polyolefin having hydrogenated aromatic vinyl polymer block units, which are hydrogenated products of polymer blocks consisting of aromatic vinyl monomer units, and hydrogenated conjugated diene polymer block units, which are hydrogenated products of polymer blocks consisting of conjugated diene monomer units, the container having a minimum thickness of 0.08 mm or more, and a water vapor permeability after storage for three months at a temperature of 40°C and a relative humidity of 25%, in which the loss in water vapor permeability from the initial content does not exceed 3.0%.

[2] The liquid container according to [1], wherein the polymer composition contains 2% by weight or more and 25% by weight or less of an alicyclic saturated hydrocarbon polymer.
[3] The liquid container according to [1] or [2], wherein the polymer composition contains 2% by weight or more and 25% by weight or less of a styrene-based block copolymer.
[4] The liquid container according to any one of [1] to [3], wherein the hydrogenated aromatic vinyl polymer block unit constituting the cyclic polyolefin is a hydrogenated polystyrene block unit which is a hydrogenated product of a polystyrene block unit composed of a styrene monomer unit, and the hydrogenated conjugated diene polymer block unit constituting the cyclic polyolefin is a hydrogenated butadiene polymer block unit which is a hydrogenated product of a butadiene polymer block composed of a butadiene monomer unit.
[5] The liquid container according to any one of [1] to [4], wherein the horizontal cross-sectional shape is an ellipse or an oval.
[6] The liquid container according to any one of [1] to [5], having a flat surface in the center of the body.

The liquid container of the present invention has excellent squeezability (flexibility) and suppression of evaporation, making it suitable as a container for eye drops, etc.

(a) is a front view showing an example of the shape of the body of a droplet container of the present invention, (b) is a side view of (a), and (c) is a plan view of (a).

The present invention will be described in detail below. However, the following description is an example of an embodiment of the present invention, and the present invention is not limited to the contents of the following description as long as it does not exceed the gist of the present invention. The present invention can be modified and implemented as desired without departing from the gist of the present invention.
In the following description, when "~" is used with a numerical value or physical property value enclosed therein, the values before and after the "~" are included.

The present invention relates to a liquid drug container which is made of a specific polymer composition and has a specific thickness and specific water vapor permeability.
The polymer composition is a composition comprising a specific cyclic polyolefin (A) (hereinafter, sometimes referred to as "component (A)"), and may further contain an alicyclic saturated hydrocarbon polymer (B) (hereinafter, sometimes referred to as "component (B)") and a styrene-based block copolymer (C) (hereinafter, sometimes referred to as "component (C)").

<Cyclic Polyolefin (A) (Component (A))>
The cyclic polyolefin (A) (component (A)) of the present invention is a hydrogenated block copolymer having a hydrogenated aromatic vinyl polymer block unit, which is a hydrogenated product of a polymer block consisting of at least one aromatic vinyl monomer unit, and a hydrogenated conjugated diene polymer block unit, which is a hydrogenated product of a polymer block consisting of at least one conjugated diene monomer unit.
The hydrogenated block copolymer has at least two of the hydrogenated aromatic vinyl polymer block units and at least one of the hydrogenated conjugated diene polymer block units.

The term "block" refers to a copolymer polymerization segment that exhibits microphase separation from structurally or compositionally distinct polymerization segments of the copolymer. Thus, for example, "having at least two block units" means that the hydrogenated block copolymer has at least two copolymer polymerization segments that exhibit microphase separation from structurally or compositionally distinct polymerization segments.

The aromatic vinyl monomer that is the raw material for the aromatic vinyl monomer unit is a monomer represented by the following general formula (1):

In general formula (1), R is hydrogen or an alkyl group.
The alkyl group may be a mono- or poly-substituted alkyl group with functional groups such as halo, nitro, amino, hydroxy, cyano, carbonyl, and carboxyl groups, and preferably has 1 to 6 carbon atoms.
Of these, R is preferably hydrogen.

In general formula (1), Ar is a phenyl group, a halophenyl group, an alkylphenyl group, an alkylhalophenyl group, a naphthyl group, a pyridinyl group, or an anthracenyl group.
Of these, Ar is preferably a phenyl group or an alkylphenyl group, more preferably a phenyl group.

Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, vinyltoluene (including all isomers, particularly p-vinyltoluene), ethylstyrene, propylstyrene, butylstyrene, vinylbiphenyl, vinylnaphthalene, vinylanthracene (all isomers), and mixtures thereof, with styrene being preferred.

The conjugated diene monomer serving as a raw material for the conjugated diene monomer unit may be any monomer having two conjugated double bonds.
Conjugated diene monomers include, for example, 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2-methyl-1,3 pentadiene and the like, and mixtures thereof, with butadiene being preferred.

Polybutadiene, a polymer of 1,3-butadiene, can contain either a 1,2 configuration that upon hydrogenation gives the equivalent of a 1-butene repeat unit, or a 1,4 configuration that upon hydrogenation gives the equivalent of an ethylene repeat unit.

A preferred example of the hydrogenated aromatic vinyl polymer block unit is a block unit made of hydrogenated polystyrene, which is a hydrogenated product of a polystyrene block unit made of styrene monomer units. A preferred example of the hydrogenated conjugated diene polymer block unit is a block unit made of hydrogenated polybutadiene, which is a hydrogenated product of a butadiene polymer block made of butadiene monomer units.
A preferred embodiment of the hydrogenated block copolymer is a hydrogenated triblock or pentablock copolymer of styrene and butadiene, which preferably does not contain any other functional groups or structural modifiers.

The content of the hydrogenated aromatic vinyl polymer block unit is 30 to 80 mol %, preferably 40 to 75 mol %, based on the cyclic polyolefin (A).
When the ratio of the hydrogenated aromatic vinyl polymer block unit is equal to or more than the above lower limit, the rigidity does not decrease, and when it is equal to or less than the above upper limit, the toughness is improved and the brittleness does not worsen.

The content of the hydrogenated conjugated diene polymer block unit is from 20 to 70 mol %, preferably from 25 to 60 mol %, based on the cyclic polyolefin (A).
When the ratio of the hydrogenated conjugated diene polymer block units is equal to or more than the above lower limit, the toughness is improved and the brittleness is not deteriorated, whereas when it is equal to or less than the above upper limit, the rigidity is not decreased.

In the present invention, the term "cyclic" in cyclic polyolefin refers to an alicyclic structure that is generated by hydrogenating the aromatic ring of the hydrogenated aromatic vinyl polymer block unit.

Hydrogenated block copolymers are produced by hydrogenation of block copolymers, including triblock, multiblock, tapered block, and star block copolymers such as SBS, SBSBS, SIS, SISIS, and SISBS (where S is polystyrene, B is polybutadiene, and I is polyisoprene).

The hydrogenated block copolymer contains a segment of aromatic vinyl polymer at each end. Therefore, the hydrogenated block copolymer has at least two hydrogenated aromatic vinyl polymer block units. And, between these two hydrogenated aromatic vinyl polymer block units, there is at least one hydrogenated conjugated diene polymer block unit.

The block copolymers that make up the hydrogenated block before hydrogenation may contain additional blocks, which may be attached at any position along the triblock polymer backbone. Thus, linear blocks include, for example, SBS, SBSB, SBSBS, and SBSBSB. The copolymers may be branched, with the polymer chains attached at any position along the backbone of the copolymer.

The lower limit of the weight average molecular weight (Mw) of the hydrogenated block copolymer is preferably 30,000 or more, more preferably 40,000 or more, even more preferably 45,000 or more, and particularly preferably 50,000 or more. The upper limit of Mw is preferably 120,000 or less, more preferably 100,000 or less, even more preferably 95,000 or less, particularly preferably 90,000 or less, most preferably 85,000 or less, and extremely preferably 80,000 or less.
When Mw is equal to or greater than the lower limit, the mechanical strength does not decrease, and when Mw is equal to or less than the upper limit, the moldability does not deteriorate.
Here, the Mw of the cyclic polyolefin (A) is determined by GPC under the same measurement conditions as those for the styrene-based block copolymer (C) described below.

The hydrogenation level of the hydrogenated block copolymer is preferably 90% or more of hydrogenated vinyl aromatic polymer block units and 95% or more of hydrogenated conjugated diene polymer block units; more preferably 95% or more of hydrogenated vinyl aromatic polymer block units and 99% or more of hydrogenated conjugated diene polymer block units; even more preferably 98% or more of hydrogenated vinyl aromatic polymer block units and 99.5% or more of hydrogenated conjugated diene polymer block units; particularly preferably 99.5% or more of hydrogenated vinyl aromatic polymer block units and 99.5% or more of hydrogenated conjugated diene polymer block units.
The hydrogenation level of the hydrogenated aromatic vinyl polymer block unit refers to the proportion of the aromatic vinyl polymer block unit saturated by hydrogenation, and the hydrogenation level of the hydrogenated conjugated diene polymer block unit refers to the proportion of the conjugated diene polymer block unit saturated by hydrogenation. Such a high level of hydrogenation is preferred for heat resistance and transparency.
The hydrogenation level of component (A) is determined using proton NMR.

The MFR of the component (A) of the present invention is preferably 0.1 g/10 min or more, more preferably 0.2 g/10 min or more, from the viewpoint of the molding method and the appearance of the molded product, and is preferably 200 g/10 min or less, more preferably 100 g/10 min or less, and even more preferably 50 g/10 min or less, from the viewpoint of material strength.
The MFR was measured in accordance with ISO R1133 at a measurement temperature of 230° C. and a measurement load of 2.16 kg.

The component (A) of the present invention may use one type alone, or two or more types differing in monomer unit composition, physical properties, etc. may be used in combination.
As the component (A) of the present invention, commercially available products can be used, specifically, ZELAS (registered trademark) manufactured by Mitsubishi Chemical Corporation.

<Alicyclic saturated hydrocarbon polymer (B) (component (B))>
The alicyclic saturated hydrocarbon polymer (B) (component (B)) is a saturated hydrocarbon having a main chain made of hydrocarbon and an alicyclic structure, and specific examples thereof include hydrogenated petroleum resins obtained by hydrogenating aromatic petroleum resins, resins obtained by hydrogenating petroleum resins containing aromatic compounds, and resins obtained by hydrogenating alicyclic hydrocarbon resins having unsaturated bonds. This hydrogenation converts the aromatic rings into alicyclic saturated structures.
This alicyclic saturated hydrocarbon polymer (B) has good compatibility with the above cyclic polyolefin (A), and can suppress evaporation and improve flexibility.

Examples of the component (B) of the present invention include hydrogenated terpene resins (Clearon (registered trademark) P, M, K series manufactured by Yasuhara Chemical Co., Ltd.), hydrogenated rosin and hydrogenated rosin ester resins (Foral (registered trademark) AX, Foral 105 manufactured by Rika Finetech Co., Ltd., Pencel (registered trademark) A manufactured by Arakawa Chemical Industries, Ltd., Ester Gum (registered trademark) H manufactured by Arakawa Chemical Industries, Ltd., Super Ester (registered trademark) A series manufactured by Arakawa Chemical Industries, Ltd.), disproportionated rosin and disproportionated rosin ester resins (Pine Crystal (registered trademark) series manufactured by Arakawa Chemical Industries, Ltd.), and C5-based petroleum resins obtained by copolymerizing C5 fractions such as pentene, isoprene, piperine, and 1,3-pentadiene produced by thermal cracking of petroleum naphtha. Examples of water-added resins include hydrogenated dicyclopentadiene resins (Escoretz (registered trademark) 5300 and 5400 series manufactured by Donex Co., Ltd., Eastotac (registered trademark) H series manufactured by Eastman Chemical Japan Co., Ltd.), partially hydrogenated aromatic modified dicyclopentadiene resins (Escoretz (registered trademark) 5600 series manufactured by Tonex Co., Ltd.), resins obtained by copolymerizing C9 fractions such as indene, vinyl toluene, α- or β-methylstyrene produced by thermal decomposition of petroleum naphtha, and hydrogenated C9 petroleum resins (Arcon (registered trademark) P and M series manufactured by Arakawa Chemical Industries Co., Ltd.), and resins obtained by hydrogenating the copolymerized petroleum resins of the above-mentioned C5 fraction and C9 fraction (Imerve (registered trademark) series manufactured by Idemitsu Kosan Co., Ltd.). These alicyclic saturated hydrocarbon polymers may be used alone or in a mixture of two or more types.

The softening point of component (B) of the present invention, as measured by JIS K6823 (ring and ball method), is preferably 100°C or higher, more preferably 115°C or higher, and particularly preferably 125°C or higher, while it is preferably 180°C or lower, more preferably 175°C or lower, even more preferably 170°C or lower, and particularly preferably 165°C or lower. If the softening point is equal to or higher than the lower limit, there is a tendency for the suppression of transpiration to be further improved. On the other hand, if the softening point is equal to or lower than the upper limit, there is a tendency for moldability to be good.

<Styrene-Based Block Copolymer (C) (Component (C))>
The styrene-based block copolymer (C) (component (C)) of the present invention is a hydrogenated styrene-based copolymer.
The styrene copolymer of the present invention is produced by hydrogenating a styrene copolymer such as polystyrene, a styrene/α-methylstyrene copolymer, a styrene/vinylnaphthalene copolymer, etc. Among these, hydrogenated polystyrene, which is a hydrogenated product of polystyrene, is preferred.

The lower limit of the weight average molecular weight (Mw) of the component (C) of the present invention is preferably 100,000 or more. The upper limit of Mw is preferably 400,000 or less, more preferably 300,000 or less, and even more preferably 200,000 or less.
When Mw is equal to or greater than the lower limit, the mechanical strength does not decrease, and when Mw is equal to or less than the upper limit, the moldability does not deteriorate.

Here, the Mw of the styrene-based block copolymer (C) is a polystyrene-equivalent value measured by gel permeation chromatography (GPC) under the following conditions.
・Equipment: Tosoh Corporation "GPC HLC-832GPC/HT"
Column: Showa Denko K.K. "AD806M/S" x 3 (The columns were calibrated using Tosoh Corporation's monodisperse polystyrene (A500, A2500, F1, F2, F4, F10, F20, F40, F288, each 0.5 mg/mL solution), and the elution volume and the logarithm of the molecular weight were approximated by a cubic equation.)
Detector: MIRAN "1A Infrared Spectrophotometer" (measurement wavelength: 3.42 μm)
Solvent: o-dichlorobenzene Temperature: 135°C
Flow rate: 1.0 mL/min Injection volume: 200 μL
Concentration: 20 mg/10 mL

The hydrogenation level of component (C) of the present invention is preferably 90% or more, more preferably 95% or more, and even more preferably 97% or more.
The hydrogenation level of the hydrogenated aromatic vinyl polymer refers to the proportion of the aromatic vinyl polymer that is saturated by hydrogenation. Such a high level of hydrogenation is preferred for heat resistance and transparency.
The hydrogenation level of the styrenic block copolymer (C) is determined using proton NMR.

The melt flow rate (MFR) of the component (C) of the present invention is preferably 0.1 g/10 min or more, more preferably 0.2 g/10 min or more, from the viewpoint of the molding method and the appearance of the molded product, and is preferably 200 g/10 min or less, more preferably 100 g/10 min or less, and even more preferably 50 g/10 min or less, from the viewpoint of material strength.
The MFR was measured in accordance with ISO R1133 at a measurement temperature of 230° C. and a measurement load of 2.16 kg.

The component (C) of the present invention may be used alone or in combination with two or more types having different monomer unit compositions, physical properties, etc.

<Polymer Composition>
The liquid container of the present invention comprises a polymer composition containing the above-mentioned component (A), and may further contain a component (B) and/or a component (C).
The content of the component (A) is preferably 72 parts by weight or more, more preferably 75 parts by weight or more, based on 100 parts by weight of the polymer composition. If the content is less than 72 parts by weight, there is a risk that the suppression of transpiration will not be sufficient.
The upper limit of the content of the component (A) may be 100 parts by weight, but when other components such as the component (B) and the component (C) are added, the upper limit is preferably 95 parts by weight.

When the (B) component is contained, the content of this (B) component is preferably 2 parts by weight or more, preferably 5 parts by weight or more, and more preferably 7 parts by weight or more, per 100 parts by weight of the polymer composition. Furthermore, when the (B) component is contained, the upper limit of the content of this (B) component is preferably 25 parts by weight or less, preferably 20 parts by weight or less, per 100 parts by weight of the polymer composition. By keeping it within the above range, it is possible to improve the squeezability (flexibility) and the suppression of transpiration. However, if it is outside the above range, there is a risk of reducing the squeezability (flexibility) and the suppression of transpiration.

When the (C) component is contained, the content of the (C) component is preferably 2 parts by weight or more, and preferably 5 parts by weight or more, per 100 parts by weight of the polymer composition. When the (C) component is contained, the upper limit of the content of the (C) component is preferably 25 parts by weight or less, and preferably 20 parts by weight or less, per 100 parts by weight of the polymer composition. By keeping the content within the above range, it is possible to improve the squeezability (flexibility) and the suppression of transpiration. However, if it is outside the above range, there is a risk of reducing the suppression of transpiration.

From the viewpoint of improving squeezability (flexibility) and suppression of transpiration, the polymer composition preferably contains components (A), (B), and (C), and the content ratio (weight ratio) of these components is within the range of component (A)/component (B)/component (C)=72-95/2-25/2-25, preferably 75-85/5-20/5-15.

<Other ingredients>
The polymer composition of the present invention may contain, as other components, compounding agents that are commonly used in resin compositions, within the range that does not impair the effects of the present invention.
Examples of such additives include heat stabilizers, ultraviolet absorbers, light stabilizers, antioxidants, antistatic agents, crystal nucleating agents, rust inhibitors, inorganic fillers, foaming agents, and pigments.
Among these, it is preferable to contain an antioxidant, particularly a phenol-based, sulfur-based or phosphorus-based antioxidant, and the antioxidant is preferably contained in an amount of 0.01 to 2 parts by mass per 100 parts by mass of the polymer composition.

Furthermore, resin components and elastomer components other than the components (A), (B) and (C) may be contained within the scope of the invention without impairing the effects thereof.
Examples of such resin components include polyethylene resins, polypropylene resins, ethylene/α-olefin copolymer resins, propylene/α-olefin copolymer resins, ethylene/vinyl acetate copolymer resins, ethylene/acrylic acid ester copolymer resins, ethylene/(meth)acrylic acid copolymer resins, polystyrene-based resins, polyvinyl chloride-based resins, polyester-based resins, polyamide-based resins, ethylene/vinyl alcohol copolymers, acrylic resins, and petroleum resins.

Examples of elastomer components include olefin-based elastomers, styrene-based elastomers, polyester-based elastomers, urethane-based elastomers, acrylic-based elastomers, and nylon-based elastomers.

The other components may be added to components (A), (B), and (C) using a kneading method commonly used for melt-kneading thermoplastic resins, or may be dissolved in an organic solvent together with component (A) and mixed.

<Method of producing polymer composition>
The polymer composition of the present invention can be produced by kneading the component (A), and, if necessary, the component (B) and the component (C), and the other components described above, in a conventional manner using a conventional extruder, Banbury mixer, roll, Brabender Plastograph, kneader-Brabender, or the like.
Among these production methods, it is preferable to use an extruder, in particular a twin-screw extruder.
When the polymer composition of the present invention is produced by kneading in an extruder or the like, it is melt-kneaded in a heated state usually at 220 to 320°C, preferably 250 to 300°C.

<Droplet container and method of manufacturing same>
The liquid drop container of the present invention can be obtained by molding the polymer composition of the present invention.
Examples of the molding method include various molding methods such as ordinary injection molding, injection blow molding, direct blow molding, etc. Among these, injection blow molding is preferred.

<Droplet container>
The liquid dropper container of the present invention is used as an eye dropper container.
The minimum thickness of the droplet container of the present invention, particularly the body, is preferably 0.08 mm or more, and more preferably 0.1 mm or more. If it is thinner than 0.08 mm, the squeezability (flexibility) is improved, but the suppression of evaporation tends to be insufficient.

An example of the shape of the body of the droplet container is shown in Fig. 1. Fig. 1 (a) shows a front view, (b) shows a side view, and (c) shows a plan view.
The horizontal cross-sectional shape of the body 11 of this droplet container may be an ellipse as shown in FIG. 1(c) or an oval shape (not shown).
In addition, a flat surface portion 12 is provided at one location or two opposing locations in the center of the body 11 of the droplet container. The flat surface portion 12 may be formed in a concave shape in the center of the body 11 of the droplet container as shown in Fig. 1(b), or may be formed along the center of the body 11 of the droplet container, or may be formed in a convex shape in the center of the body 11 of the droplet container, although not shown.
The flat surface portion may be provided on an elliptical oval portion or a straight portion of an elliptical oval portion of the droplet container as shown in Fig. 1, or may be provided on a short circular portion or a curved portion of an elliptical oval portion of the droplet container, although not shown. Among these, in order to enhance squeezability, it is preferable to provide the flat surface portion on an elliptical oval portion or a straight portion of an elliptical oval portion of the droplet container.

<Transpiration (water vapor permeability)>
The transpiration property refers to the property that a part of the components in the sealed droplet container transpire outside the droplet container, and can be judged by the water vapor permeability of the droplet container. Specifically, the droplet container is filled with a predetermined amount of water, the cap is tightened with a certain torque, and the container is stored in a thermostatic chamber at a temperature of 40° C. and a relative humidity of 25% for three months. The amount of water lost before and after storage is taken as the amount of transpiration, and the transpiration property (water vapor permeability) is calculated from the following formula.
Transpiration (%) = transpiration amount / water filling amount x 100
This transpiration (water vapor permeability) must not exceed 3.0% by weight, and is preferably 2.5% by weight or less. If the transpiration does not exceed 3.0% by weight, the transpiration will be the same as or lower than that of conventional droplet containers made of polyethylene, polypropylene, etc., and therefore it is possible to suppress changes in the components of the ophthalmic composition in the droplet container.
On the other hand, if the transpiration rate is 3.0% by weight or more, the volatility of the highly volatile components in the ophthalmic composition in the droplet container will increase, which may cause changes in the component ratio of the ophthalmic composition.

<Squeezability (flexibility)>
Squeezability refers to the property of being able to push out the contents of a bottle, tube, etc. In other words, if a bottle or tube container has flexibility, it becomes possible to push out the contents, and squeezability can be exhibited.
The squeezability (flexibility) was measured by filling the droplet container with the ophthalmic composition, attaching a nozzle to it, pointing the nozzle downward, and applying a force to push two opposing points in the center of the body of the droplet container into the interior of the droplet container, and measuring the force (N) required to drip one drop.
The dropping force is preferably equal to or less than 15 N. If it is greater than 15 N, a large force is required to drop the ophthalmic composition, and the squeezability (flexibility) is not sufficient.
On the other hand, the lower limit of the dropping force is preferably equal to or greater than 2 N. If the dropping force is less than 2 N, problems may occur in that the amount of dropping is unstable, such as the amount of one drop dropping being more than necessary.

The present invention will be described in more detail below using examples, but the present invention is not limited to the following examples as long as it does not exceed the gist of the invention. The values of various production conditions and evaluation results in the following examples are meant as preferred upper or lower limit values in the embodiment of the present invention, and the preferred range may be a range defined by a combination of the above-mentioned upper or lower limit values and the values of the following examples or values of the examples.
In the following description, "parts" refers to "parts by mass".

[Physical Properties]
<Ratio of Polymer Blocks of Cyclic Polyolefin (A)>
[Measurement by Carbon NMR]
Apparatus: Bruker "AVANCE 400 Spectrometer"
Solvent: o-dichlorobenzene- _h4 /p-dichlorobenzene- _d4 mixed solvent Concentration: 0.3 g/2.5 mL
Measurement: ^13C -NMR
Resonance frequency: 400MHz
・Number of times accumulated: 1536
Flip angle: 45 degrees Data acquisition time: 1.5 seconds Pulse repetition time: 15 seconds Measurement temperature: 100°C
・^1H irradiation: Complete decoupling

<Hydrogenation level>
[Measurement by proton NMR]
Apparatus: JASCO Corporation "400YH spectrometer"
Solvent: deuterated chloroform Concentration: 0.045 g/1.0 mL
Measurement: ¹ H-NMR
Resonance frequency: 400MHz
・Number of times: 8
Measurement temperature: 18.5°C
Hydrogenation level of styrene block copolymer (C): integral value reduction rate of 6.8 to 7.5 ppm Hydrogenation level of hydrogenated aromatic vinyl polymer block unit of cyclic polyolefin (A): integral value reduction rate of 6.8 to 7.5 ppm Hydrogenation level of hydrogenated conjugated diene polymer block unit of cyclic polyolefin (A): integral value reduction rate of 5.7 to 6.4 ppm

<Thickness>
The thickness (minimum thickness, maximum thickness) of the resulting droplet container was measured using a magnetic thickness meter manufactured by Olympus Corporation.
Generally, the thickness near the bottom of the long axis end of the droplet container (near the part a surrounded by the dotted line in Figure 1(a)) is the minimum thickness, and the thickness near the center of the flat surface of the body (near the part b surrounded by the dotted line in Figure 1(a)) is the maximum thickness.

<Transpiration (water vapor permeability)>
The transpiration property (water vapor permeability) of the obtained droplet container was measured and calculated by the following method.
First, the empty weight of the droplet container was measured. Then, a specified amount (5 mL) of water was filled into the droplet container. The cap was tightened with a closing torque of 79 N cm. Then, the mass after filling with water was measured and the amount of water filled was calculated.
Next, the droplet containers filled with the water were placed in thermostatic chambers under the specified conditions (temperature 40° C., relative humidity 25%, and temperature 25° C., relative humidity 40%) and stored for three months.
After three months, the droplet container was removed and the mass was measured. The transpiration rate was calculated using the following formula.
Evaporation rate [%] = (mass of droplet container before storage - mass of droplet container after storage) [mg] / amount of water filled [mg] x 100

<Squeezability (flexibility)>
The dropping force of the dropper container was measured by the following method.
First, 5 mL of distilled water was filled into the droplet container and the nozzle was plugged. Next, the mouth of the droplet container was oriented directly downward, and the load required to drip one drop of distilled water was measured using a force gauge under the following measurement conditions. The measurement results are the average value of the dripping force measured by testing 10 specimens.
(Measurement condition)
Measurement equipment: Imada force gauge Measurement environment: 23°C, 50% RH
- Push speed: 0.2 mm/s
・Press position: Center of bottle flat surface ・Number of drops: 10 times

[material]
(Cyclic Polyolefin (A))
Cyclic polyolefin (A-1)...Mitsubishi Chemical Corporation: ZELAS Density (ASTM D792): 0.94 g/cm ³
Melt flow rate (MFR) (230°C, 2.16 kg): 0.5 g/10 min. Hydrogenated aromatic vinyl polymer block unit: hydrogenated polystyrene with a content of 50 mol% and a hydrogenation level of 98.7%. Hydrogenated conjugated diene polymer block unit: hydrogenated polybutadiene with a content of 50 mol% and a hydrogenation level of 99.5% or more. Block structure: pentablock structure, total hydrogenation level: 99.2%.

Cyclic polyolefin (A-2)...Mitsubishi Chemical Corporation: ZELAS Density (ASTM D792): 0.94 g/cm ³
MFR (230°C, 2.16 kg): 1.1 g/10 min. Hydrogenated aromatic vinyl polymer block unit: hydrogenated polystyrene with a content of 50 mol% and a hydrogenation level of 99.9%. Hydrogenated conjugated diene polymer block unit: hydrogenated polybutadiene with a content of 50 mol% and a hydrogenation level of 99.8% or more. Block structure: pentablock structure, total hydrogenation level: 99.8%.

(Alicyclic Saturated Hydrocarbon Polymer (B))
Alicyclic saturated hydrocarbon polymer (B-1)
Density (ASTM D792): 1.00 g/ ^cm3
・C9 hydrogenated petroleum resin ・Softening temperature: 115℃

(Styrene-based block copolymer (C))
Styrene-based block copolymer (C-1)
Hydrogenated styrene-butadiene-styrene block copolymer, aromatic vinyl polymer block unit (polystyrene block unit): 30% by mass, hydrogenation rate of butadiene: 99% or more, Mw: 90,000

Styrene-based block copolymer (C-2)
Hydrogenated styrene-butadiene-styrene block copolymer, aromatic vinyl polymer block unit (polystyrene block unit): 30% by mass, hydrogenation rate of butadiene: 99% or more, Mw: 60,000

[Examples 1 to 10, Comparative Examples 1 to 2]
Components (A), (B) and (C) shown in Table 1 were blended in the amounts shown in Table 1, and melt-kneaded in a twin-screw extruder at an elevated temperature in the range of 220°C to 280°C to obtain pellets of a thermoplastic polymer composition. The obtained pellets were used to produce the body of the droplet container shown in Figure 1 by injection blow molding. The above evaluations were carried out using this. The results are shown in Table 1.

From Table 1, it is clear that each Example had sufficient transpiration property and squeezability.
On the other hand, it was revealed that Comparative Examples 1 and 2 had too high transpiration.

11: Body of the droplet container 12: Flat surface portion a: Near the bottom of the long axis end of the droplet container b: Near the center of the flat surface portion of the body

Claims (6)

The polymer composition comprises 72% by weight or more of a cyclic polyolefin having a hydrogenated aromatic vinyl polymer block unit, which is a hydrogenated product of a polymer block composed of an aromatic vinyl monomer unit, and a hydrogenated conjugated diene polymer block unit, which is a hydrogenated product of a polymer block composed of a conjugated diene monomer unit;
A liquid container characterized in that the container has a minimum thickness of 0.08 mm or more, and that after storage for three months at a temperature of 40°C and a relative humidity of 25%, the water vapor permeability is such that the loss in weight from the initial content does not exceed 3.0%. The liquid container according to claim 1, wherein the polymer composition contains 2% by weight or more and 25% by weight or less of an alicyclic saturated hydrocarbon polymer. The liquid container according to claim 1 or 2, wherein the polymer composition contains 2% by weight or more and 25% by weight or less of a styrene-based block copolymer. the hydrogenated aromatic vinyl polymer block unit constituting the cyclic polyolefin is a hydrogenated polystyrene block unit which is a hydrogenated product of a polystyrene block unit composed of a styrene monomer unit,
3. The liquid container according to claim 1, wherein the hydrogenated conjugated diene polymer block unit constituting the cyclic polyolefin is a hydrogenated butadiene polymer block unit which is a hydrogenated product of a butadiene polymer block composed of butadiene monomer units. The liquid container according to claim 1 or 2, the horizontal cross-sectional shape of which is elliptical or oblong. The liquid container according to claim 1 or 2, which has a flat surface in the center of the body.

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