JP4101465B2 - Medical containers that can be autoclaved and store chemicals - Google Patents

Description

【００２３】
【表２】

【００２４】
【表３】

【００２５】
（１）耐熱性の評価
実施例１から５および比較例１から７の医療用容器１について、滅菌後の容器の外観、変形等を目視にて確認した。また、内外層の融解ピーク温度をセイコーインスツルメンツ株式会社製ＤＳＣ６２００にて測定した。耐熱性の評価結果を表４に示した。
【００２６】
（２）成形性の評価
実施例１から５および比較例１から７の積層体２について、インフレーション成形における成形パラメーターとして樹脂温度（℃）、樹脂圧力（ｋｇｆ／ｃｍ^２）を測定した。成形性の評価結果を表４に示した。
【００２７】
（３）柔軟性の評価
実施例１から５および比較例１から７の医療用容器１について、容器から１０ｍｍ幅の短冊状試験片を作製し、（株）東洋精機製作所製ストログラフＥ−Ｌを使用して、試験速度５０ｍｍ／ｍｉｎ、試験温度２３±１℃における５％割線弾性率（MＰa）を測定した。柔軟性の評価結果を表５に示した。
【００２８】
（４）透明性の評価
実施例１から５および比較例１から７の医療用容器１について、容器から試験片を作製し、ＪＩＳＫ７１０５に準じて、（株）東洋精機製作所製直読ヘイズメーターを使用してヘイズ（％）を測定した。透明性の評価結果を表５に示した。
【００２９】
（５）耐屈曲疲労性の評価
実施例１から５および比較例１から７の医療用容器１について、容器から２０×１２０ｍｍの短冊状試験片を作製し、（株）東洋精機製作所製ＭＩＴ耐揉疲労試験機により、５０００回の屈曲疲労試験を行い、試験終了後の試験片から、さらにＪＩＳ２号試験片を作製し、（株）東洋精機製作所製ストログラフＥ−Ｌを使用して、試験速度２００ｍｍ／ｍｉｎ、試験温度２３±１℃における破断強度（MＰa）を測定した。これとは別に屈曲疲労試験前の破断強度（MＰa）を測定し、屈曲疲労試験の前後における物性値の比較から屈曲疲労度（％）を算出した。なお、屈曲疲労度は下記の式により算出した。耐屈曲疲労性の評価結果を表５に示した。
屈曲疲労度（％）＝（疲労前の物性値−疲労後の物性値）／疲労前の物性値
【００３０】
（６）耐低温衝撃性の評価
実施例１から５および比較例１から７の医療用容器１について、容器のシール部分より、３号試験片を作製し、ＪＩＳＫ７１６０に準じて、ハンマー４Ｊ、試験温度４±１℃におけるテンサイル衝撃強度を測定した。
同様に、実施例１から５および比較例１から７の医療用容器１について、２±１℃に保存し、１．５ｍの高さから最高で１０回落下させ、容器が破損した回数を測定した。耐低温衝撃性の評価結果を表６に示した。
【００３１】
（７）シール性評価
実施例１から５および比較例１から７の医療用容器１について、容器のシール部分より、１０ｍｍ幅の短冊状試験片を作製し、（株）東洋精機製作所製ストログラフＥ−Ｌを使用して、試験速度２００ｍｍ／ｍｉｎ、試験温度２３±１℃におけるシール強度（Ｎ／１０ｍｍ）を測定した。シール性の評価結果を表６に示した。
【００３２】
【表４】

【００３３】
【表５】

【００３４】
【表６】

【００３５】
表４に示された耐熱性の評価結果から、実施例１〜５は良好な耐熱性を有していることは明らかであり、比較例１よりメタロセンポリエチレン（低密度成分（Ａ）と中高密度成分（Ｂ）の重合体組成物）のみまたは比較例２よりチーグラーポリエチレン（成分（Ｃ））単独では耐熱性が不足していることが分かる。また、比較例５と比較例７より外層３または内層４の融点が低い場合、容器の外観に問題が発生することが明らかである。
【００３６】
表４に示された成形性の評価結果においては、比較例１よりメタロセンポリエチレン（低密度成分（Ａ）と中高密度成分（Ｂ）の重合体組成物）のみでは樹脂温度および樹脂圧力の両方が高い数値を示し、成形性が不足していることが分かる。一方、比較例２よりチーグラーポリエチレン単独では良好な成形性を有していることが分かる。実施例１〜５はメタロセンポリエチレンとチーグラーポリエチレンの配合バランスにより、良好な成形性を有していることが明らかである。また、比較例５のように低密度成分（Ａ）と中高密度成分（Ｂ）の重合体組成物の配合バランスに、一方に著しい偏りがある場合は、樹脂圧力が高くなり、成形性が失われることが分かる。
【００３７】
表５に示された柔軟性の評価結果から、実施例１〜５は良好な柔軟性を有していることが明らかである。また、比較例４から、中・高密度成分である（Ｂ）または（Ｃ）の配合量が多いと柔軟性が失われ、さらに、比較例６から、密度の高いメタロセンポリエチレン、チーグラーポリエチレンを使用すると柔軟性が失われることが分かる。
【００３８】
表５に示された透明性の評価結果から、実施例１〜５は良好な透明性を有していることが明らかである。表４の比較例１、５、７から、容器の耐熱性が不足すると表５のように透明性が失われることがわかる。また、比較例２のようにチーグラーポリエチレン単独では、十分な透明性を有していないことが明らかである。さらに、比較例３のように外層３の肉厚が厚い場合（５０％）や比較例４のように中・高密度成分である（Ｂ）または（Ｃ）の配合量が多い場合（４０または５０重量％、両方で９０重量％）、さらに比較例６のように密度の高い（０．９３７ｇ／ｃｍ^３）メタロセンポリエチレン、チーグラーポリエチレンを使用すると透明性が失われることが分かる。
【００３９】
表５に示された耐屈曲疲労性の評価結果から、実施例１〜５は良好な耐屈曲疲労性を有していることが明らかである。また、比較例２のようにチーグラーポリエチレン単独では、十分な耐屈曲疲労性を有していないことがわかる。さらに、比較例３のように外層３の肉厚が厚い場合や比較例１、４のように中・高密度成分である（Ｂ）または（Ｃ）の配合量が多い場合や、比較例６のように密度の高いメタロセンポリエチレン、チーグラーポリエチレンを使用すると耐屈曲疲労性が失われることが分かる。
【００４０】
表６に示された耐低温衝撃性の評価結果から、実施例１〜５は良好な耐低温衝撃性を有していることが明らかである。また、比較例２のようにチーグラーポリエチレン単独では、十分な耐低温衝撃性を有していないことがわかる。比較例３のように外層３の肉厚が厚い場合や比較例１、４のように中・高密度成分である（Ｂ）または（Ｃ）の配合量が多い場合や、比較例６のように密度の高いメタロセンポリエチレン、チーグラーポリエチレンを使用すると耐低温衝撃性が失われることが分かる。
【００４１】
表６に示されたシール強度の評価結果から、実施例１〜５は良好なシール性を有していることが明らかである。また、比較例３のように内層３の肉厚が薄い場合や比較例４のように低密度成分である（Ａ）の配合量が少ない場合、シール性が失われることが分かる。
【００４２】
【発明の作用効果】
以上に述べたように、本発明による医療用容器１は、耐熱性、柔軟性、透明性、耐低温衝撃性、耐屈曲疲労性、ヒートシール性等の物性バランスおよび成形時の加工性に優れ、かつ高圧蒸気滅菌が可能であることから特に薬液を保存する輸液容器として好適に使用できる。
【図面の簡単な説明】
【図１】本発明の医療用容器１である。
【図２】本発明の医療用容器１を構成する積層体２の一部拡大断面図である。
【図３】本発明の医療用容器１を構成する積層耐２の製造方法の一例を示す概略図である。
【符号の説明】
１ 医療用容器
２ 積層体
３ 外層
４ 内層
５、６ ホッパー
７、８ 押出機
９ 多層ダイ
１０ サイジングリング
１１ 安定板
１２ ピンチロール
１３ 引取ロール
１４ 巻取機[0001]
[Industrial application fields]
The present invention relates to a medical container such as a blood bag, an infusion (medical solution) bag, an artificial dialysis bag, etc., and includes heat resistance, flexibility, transparency, low temperature impact resistance, bending fatigue resistance, heat sealability, etc. In particular, the present invention relates to a medical container suitable for an infusion container or the like for storing a drug solution, which is excellent in the balance of physical properties and processability at the time of molding and is capable of high-pressure steam sterilization.
[0002]
[Background Art and Problems to be Solved by the Invention]
Conventionally, medical container materials used in the medical field are required to have various physical properties as well as safety and hygiene. In particular, heat resistance against high-pressure steam sterilization, flexibility to ensure drainage in closed systems for infusion therapy, transparency to confirm the contents, low temperature impact resistance to prevent damage to containers due to drop impact or vibration And the balance of physical properties such as bending fatigue resistance, bag making processing and heat sealability necessary to prevent leakage of liquid contents are required, and soft polyvinyl chloride and polyethylene resin as the main component of medical container materials Polypropylene resin or the like is used.
[0003]
However, soft polyvinyl chloride is excellent in heat resistance, flexibility, transparency, etc., but is inferior in low-temperature impact resistance, and may cause safety problems due to elution of the plasticizer into the chemical solution and residual monomers. And is not preferable as a medical container material. In addition, polypropylene resin has good heat resistance, but it is poor in flexibility, it is difficult to drain in the closed system of infusion therapy, it is inferior in low temperature impact resistance, and the container may be damaged, It is not preferable as a medical container material.
[0004]
Similarly, ethylene-vinyl acetate copolymer has good transparency, flexibility and low-temperature impact resistance, but lacks heat resistance to withstand high-pressure steam sterilization. Has good heat resistance, but lacks transparency, flexibility and low-temperature impact resistance, and is not preferable as a medical container material.
Among such polyethylene resins, linear low density polyethylene or ethylene-α-olefin copolymer (hereinafter abbreviated as Ziegler polyethylene) polymerized by a Ziegler-Natta catalyst, which is said to have a relatively excellent balance of physical properties. In JP-A-3-277366, JP-A-4-150860, JP-A-4-266759, JP-A-6-246886, etc., there are various proposals for improving physical properties, blending, and multilayering of Ziegler polyethylene. However, the physical properties required for medical containers are insufficient at present.
[0005]
Under such circumstances, linear low density polyethylene or ethylene-α-olefin copolymer (hereinafter abbreviated as metallocene polyethylene) polymerized using a metallocene catalyst was used to cope with the above problems. Medical containers have been considered. For example, various proposals for metallocene polyethylene have been made in JP-A-9-99035 and JP-A-11-152378. Metallocene polyethylene is said to exhibit superior physical properties than Ziegler polyethylene because of its homogeneous composition distribution, but in reality it has few high-density components and is inferior in heat resistance. When using a metallocene polyethylene of high density to high density alone, flexibility and bending fatigue resistance are insufficient, and there is a possibility of problems such as heat generation and high temperature molding in the workability during molding. It is not preferable.
[0006]
Therefore, the object of the present invention is excellent in the balance of physical properties such as heat resistance, flexibility, transparency, low temperature impact resistance, bending fatigue resistance, heat sealability, and workability at the time of molding, and is capable of high-pressure steam sterilization. In particular, the present invention relates to a medical container suitable for an infusion container or the like for storing a chemical solution, and as a result of intensive studies from the above viewpoint, the present inventors have reached the following invention.
[0007]
[Means for Solving the Problems]
[1] The present invention provides a medical container in which a container body is constituted by a laminate (2) comprising an inner layer (3) and an outer layer (4).
The outer layer (3) of the laminate (2) is formed from a linear low density polyethylene or ethylene-α-olefin copolymer polymerized using a metallocene catalyst having a density of 0.920 to 0.930 g / cm ^3. And
The linear low density polyethylene polymerized using the metallocene catalyst of the outer layer (3) or the ethylene-α-olefin copolymer has a melting peak temperature of 115 ° C. or higher as measured by a differential scanning calorimeter and an MFR of 1 to 10 g. / 10 minutes,
The inner layer (4) of the laminate (2) is
(A) a linear low density polyethylene or ethylene-α-olefin copolymer polymerized using a metallocene catalyst having a density of less than 0.890-0.920 g / cm ³ and (B) a density of 0.920-0. Polymerized with linear low density polyethylene or ethylene-α-olefin copolymer polymerized using a 930 g / cm ³ metallocene catalyst and (C) a Ziegler-Natta catalyst with a density of 0.910 to 0.930 g / cm ³ Formed from a polymer composition comprising a linear low density polyethylene or an ethylene-α-olefin copolymer,
The blending ratio of the components (A), (B) and (C) of the polymer composition constituting the inner layer (4) is (A) 40 to 75% by weight, (B) 5 to 30% by weight, (C) 10 to 40% by weight,
And the melting peak temperature by the differential scanning calorimeter of the polymer composition consisting of the components (A), (B) and (C) is 110 ° C. or higher, and the MFR is 1 to 10 g / 10 min.
The ratio of the thickness of the inner layer (4) to 65% to 85% of the total thickness of the laminate (2) is 100%,
The laminate (2) after high-pressure steam sterilization under conditions of a temperature of 110 ° C., a gauge pressure of 1.5 kgf / cm ² and a time of 30 minutes has the following characteristics (a) to (d):
(A) 5% secant elastic modulus is 200 MPa or less, (b) Haze is 15% or less, (c) Physical properties after performing bending fatigue operation 5000 times at room temperature by MIT fatigue resistance tester The rate of decrease with respect to physical properties is 10% or less, (d) Tensile impact strength of the seal portion is 500 kJ / m ² or more,
A medical container capable of high-pressure steam sterilization and storing a chemical solution is provided.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is an example of a medical container 1 of the present invention, and FIG. 2 is a partially enlarged cross-sectional view of a laminate 2 constituting the medical container 1. The medical container 1 is formed by welding a peripheral portion or a part of the peripheral portion of the laminate 2 composed of the outer layer 3 and the inner layer 4.
[0009]
Linear low density polyethylene (hereinafter abbreviated as metallocene polyethylene) polymerized using the metallocene catalyst used in the components (A) and (B) of the polymer composition constituting the outer layer 3 and the inner layer 4, It is a linear low density polyethylene produced using a metallocene catalyst also called kaminsky-sinn catalyst (single site catalyst), and the metallocene catalyst used is a transition metal compound mainly composed of transition metals such as Zr, Hf, Ti, etc. And an ionic compound that reacts with an organometallic compound or a transition metal compound to form a stable anion.
Examples of the α-olefin in the ethylene-α-olefin copolymer include butene-1, pentene-1, hexene-1, octene-1, decene-1, 4-methylpentene-1. These α-olefins may be used singly or in combination of two or more. Metallocene polyethylene has a narrow molecular weight distribution, rich randomness, and a homogeneous structure compared to normal Ziegler polyethylene, so the crystal size is uniform, transparency, flexibility, low temperature impact resistance, bending fatigue resistance, Excellent balance of physical properties such as heat sealability.
[0010]
Further, the linear low density polyethylene or ethylene-α-olefin copolymer used for the component (C) of the polymer composition constituting the inner layer 4 is polymerized to a Ziegler-Natta catalyst to produce an ethylene-α-olefin copolymer. Examples of the α-olefin in the polymer include butene-1, pentene-1, hexene-1, octene-1, decene-1, 4-methylpentene-1. These α-olefins may be used singly or in combination of two or more. Ziegler polyethylene has a wide molecular weight distribution, moderately contains high-density components and low-density components, good heat resistance, and excellent processability during molding.
[0011]
The ratio of the wall thickness of the inner layer 4 to the wall thickness 100% of the entire laminate 2 is 65% to 85%, more preferably 70 to 80%. If the ratio of the thickness of the inner layer 4 to the thickness of the laminate 2 is less than 65%, the flexibility, transparency, low temperature impact resistance, and bending fatigue resistance cannot be maintained, which is not preferable. Moreover, when the ratio of the thickness of the inner layer 4 to the thickness of the laminate 2 exceeds 85%, heat resistance and heat sealability cannot be maintained, and it is difficult to control the thickness, which is a problem in processing. Is not preferable.
[0012]
Further, the inner layer 4 includes (A) a metallocene polyethylene having a density of 0.890 to 0.920 g / cm ³ and (B) a metallocene polyethylene having a density of 0.920 to 0.930 g / cm ³ and (C) a density of 0.910 to 0.910. It is formed from 0.930 g / cm ³ Ziegler polyethylene, and the more preferable densities of (A), (B) and (C) are (A) 0.905 to 0.915 g / cm ³ and (B) 0. 925 to 0.930 g / cm ³ and (C) 0.915 to 0.925 g / cm ³ . Density metallocene polyethylene (A) heat resistance is insufficient with less than 0.890 g / cm ^3, may affect the insoluble particles of the content liquid contained in the container, a 0.920 g / cm ³ If it exceeds, transparency is insufficient, and further, flexibility, low temperature impact resistance, bending fatigue resistance, and heat sealability are insufficient. If the density of the metallocene polyethylene (B) is less than 0.920 g / cm ³ , the heat resistance is insufficient, and if it exceeds 0.930 g / cm ³ , the transparency is insufficient, and further, flexibility, low temperature impact resistance, This is not preferable because bending fatigue is insufficient. If the density of the Ziegler polyethylene (C) is less than 0.910 g / cm ³ , the heat resistance is insufficient, and if it exceeds 0.930 g / cm ³ , the transparency is insufficient, and further, flexibility, low temperature impact resistance, This is not preferable because bending fatigue is insufficient.
Moreover, the melting peak temperature by the differential scanning calorimeter of the polymer composition which consists of component (A), (B) and (C) used for the inner layer 4, and the metallocene polyethylene used for the outer layer 3 is 110 degreeC or more. More preferably, it is 115 ° C. or higher. If the melting peak temperature is less than 110 ° C., the heat resistance is insufficient, the inner surface may be melted in high-pressure steam sterilization, and insoluble fine particles of the content liquid may increase. Such a trace may occur, which is not preferable. The melting peak temperature of the polymer composition used for the inner layer 4 is preferably 110 ° C. or higher, and the melting peak temperature of the metallocene polyethylene used for the outer layer 3 is preferably 115 ° C. or higher.
[0013]
The blending ratio of the components (A), (B) and (C) contained in the polymer composition of the inner layer 4 is (A) 40 to 75% by weight, (B) 5 to 30% by weight, (C) 10 to 10%. 40% by weight, more preferably (A) 50 to 70% by weight, (B) 10 to 20% by weight, and (C) 15 to 35% by weight. If the blending ratio of (A) is less than 40%, flexibility, transparency, low temperature impact resistance and bending fatigue resistance cannot be maintained, which is not preferable. On the other hand, when the blending ratio exceeds 75% by weight, the heat resistance is insufficient, which is not preferable. Similarly, if the blending ratio of (B) is less than 5%, the heat resistance is insufficient, which is not preferable. On the other hand, when the blending ratio exceeds 30% by weight, the low temperature impact resistance and the bending fatigue resistance are insufficient, which is not preferable. Furthermore, if the blending ratio of (C) is less than 10%, the heat resistance is insufficient, which is not preferable. On the other hand, if the blending ratio exceeds 40% by weight, transparency, low temperature impact resistance and bending fatigue resistance are insufficient, which is not preferable.
[0014]
The density of the metallocene polyethylene used for the outer layer 3 is 0.920 to 0.930 g / cm ³ , more preferably 0.922 to 0.928 g / cm ³ . When the density is less than 0.920 g / cm ³ , the heat resistance is insufficient, which is not preferable. Similarly, if the density exceeds 0.930 g / cm ³ , the transparency is insufficient, and further, the low temperature impact resistance and the bending fatigue resistance are insufficient. Moreover, the melting peak temperature by the differential scanning calorimeter of the metallocene polyethylene used for the outer layer 3 is 115 degreeC or more, More preferably, it is 120 degreeC or more. When the melting peak temperature is lower than 115 ° C., the heat resistance is insufficient, and the container may be melted and deformed in high-pressure steam sterilization and an avatar-like unevenness may occur on the outer surface.
[0015]
The polymer composition comprising the metallocene polyethylene used for the outer layer 3 and the components (A), (B) and (C) of the inner layer 4 was measured under a load of 190 ° C. and 21.18 N according to JISK7210. The MFR is 1 to 10 g / 10 minutes, more preferably 1 to 4 g / 10 minutes. If the MFR is less than 1 g / 10 min, the fluidity of the material is inferior, high-temperature molding is forced, problems in molding such as burning and heat generation occur, and further, melt fracture occurs on the outer surface of the laminate 2. Is not preferable. If the MFR exceeds 10 g / 10 minutes, the melt tension of the material is insufficient, and problems such as difficulty in controlling the thickness of the laminate 2 occur, which is not preferable.
[0016]
The medical container of the present invention has an excellent balance between flexibility and transparency, and (a) 5% secant after high-pressure steam sterilization treatment in consideration of container handling and drainage in a closed system of infusion therapy The elastic modulus is preferably 200 MPa or less. Similarly, since it is necessary to confirm the content liquid stored in the container, it is preferable that the haze according to (b) JISK7105 after high-pressure steam sterilization is 15% or less.
[0017]
In addition, the medical container of the present invention has an excellent balance of physical properties such as low temperature impact resistance and bending fatigue resistance. In order to prevent damage to the container due to drop impact or vibration, (c ) The ratio of physical properties after bending fatigue operation 5000 times at room temperature with an MIT fatigue resistance tester is 10% or less with respect to the physical properties before the operation. (D) Measured according to JISK7160 It is preferable that the tensile impact strength of the seal portion at 4 ° C. is 500 kJ / m ² or more.
[0018]
As a method for producing the medical container 1 of the present invention, extrusion molding and blow molding are suitable. For extrusion molding, inflation molding using a multilayer die, co-extrusion molding such as T-die molding, lamination molding, and the like are possible. Similarly, multilayer extrusion blow molding is also possible. Among the above production methods, the inflation molding method is particularly suitable.
For example, as shown in FIG. 3, the material of each layer (outer layer 3 / inner layer 4) is supplied from hoppers 5 and 6, melted and kneaded by extruders 7 and 8, and formed into a tube by multilayer die 9. Next, it is adjusted to an appropriate size by the sizing ring 10, folded into a sheet shape via the stabilizing plate 11 and the pinch roll 12, passed through the take-up roll 13, and taken up in a roll shape by the winder 14.
[0019]
The polymer composition comprising the metallocene polyethylene used in the outer layer 3 of the present invention and the components (A), (B) and (C) used in the inner layer 4 may include an antioxidant, if necessary. You may add well-known compounding agents, such as a ultraviolet absorber, a nucleating agent, and a lubricant, in the range which does not impair the objective of this invention.
[0020]
【Example】
EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.
[0021]
The composition shown in Table 2 is used in combination with the polymer composition composed of the metallocene polyethylene used in the outer layer 3 and the components (A), (B) and (C) used in the inner layer 4 with the contents shown in Table 1. According to the table, the polymer composition resin composed of the components (A), (B) and (C) used for the inner layer 4 is dry blended, and the wall thickness structure of the outer layer 3 and the inner layer 4 shown in the table Thus, the laminate 2 was produced by inflation molding under the molding process conditions shown in Table 3. Using this laminate 2, the peripheral part is thermally welded at a mold temperature of 120 ° C. and a seal pressure of 0.2 MPa to produce a medical container 1 having a capacity of 1000 ml, and the temperature is 110 ° C. and the gauge pressure is 1.5 kgf / cm. ^2. Retort type high pressure steam sterilization was performed under the condition of 30 minutes. Each characteristic value of the medical container 1 after sterilization and the moldability of the laminate 2 were measured by the following evaluation items.
[0022]
[Table 1]

[0023]
[Table 2]

[0024]
[Table 3]

[0025]
(1) Evaluation of heat resistance About the medical containers 1 of Examples 1 to 5 and Comparative Examples 1 to 7, the appearance and deformation of the containers after sterilization were visually confirmed. Moreover, the melting peak temperature of the inner and outer layers was measured with a DSC6200 manufactured by Seiko Instruments Inc. Table 4 shows the evaluation results of heat resistance.
[0026]
(2) Evaluation of moldability For the laminates 2 of Examples 1 to 5 and Comparative Examples 1 to 7, the resin temperature (° C.) and the resin pressure (kgf / cm ² ) were measured as molding parameters in inflation molding. The evaluation results of formability are shown in Table 4.
[0027]
(3) Flexibility evaluation For the medical containers 1 of Examples 1 to 5 and Comparative Examples 1 to 7, a 10 mm-wide strip-shaped test piece was prepared from the container, and Strograph EL produced by Toyo Seiki Seisakusho Co., Ltd. Was used to measure the 5% secant modulus (MPa) at a test speed of 50 mm / min and a test temperature of 23 ± 1 ° C. The evaluation results of the flexibility are shown in Table 5.
[0028]
(4) Evaluation of transparency For the medical containers 1 of Examples 1 to 5 and Comparative Examples 1 to 7, test specimens were prepared from the containers, and a direct reading haze meter manufactured by Toyo Seiki Seisakusho was used according to JISK7105. Then, haze (%) was measured. The evaluation results of transparency are shown in Table 5.
[0029]
(5) Evaluation of Bending Fatigue Resistance For the medical containers 1 of Examples 1 to 5 and Comparative Examples 1 to 7, 20 × 120 mm strip-shaped test pieces were prepared from the containers, and MIT resistance manufactured by Toyo Seiki Seisakusho Co., Ltd. 5,000 flexural fatigue tests were performed with a heel fatigue tester, and a JIS No. 2 test piece was prepared from the test piece after the test was completed, and the test was performed using a strograph E-L manufactured by Toyo Seiki Seisakusho. The breaking strength (MPa) at a speed of 200 mm / min and a test temperature of 23 ± 1 ° C. was measured. Separately from this, the breaking strength (MPa) before the bending fatigue test was measured, and the bending fatigue degree (%) was calculated from the comparison of the physical property values before and after the bending fatigue test. In addition, the bending fatigue degree was calculated by the following formula. The evaluation results of the bending fatigue resistance are shown in Table 5.
Flexural fatigue (%) = (Physical property value before fatigue−Physical property value after fatigue) / Physical property value before fatigue
(6) Evaluation of low-temperature impact resistance For the medical containers 1 of Examples 1 to 5 and Comparative Examples 1 to 7, a No. 3 test piece was prepared from the sealed portion of the container, and the hammer 4J was tested according to JISK7160. Tensile impact strength at a temperature of 4 ± 1 ° C. was measured.
Similarly, the medical containers 1 of Examples 1 to 5 and Comparative Examples 1 to 7 were stored at 2 ± 1 ° C., dropped from a height of 1.5 m at most 10 times, and the number of times the container was damaged was measured. did. The evaluation results of low temperature impact resistance are shown in Table 6.
[0031]
(7) Sealability Evaluation For the medical containers 1 of Examples 1 to 5 and Comparative Examples 1 to 7, a 10 mm wide strip-shaped test piece was prepared from the sealed portion of the container, and a strograph manufactured by Toyo Seiki Seisakusho Co., Ltd. Using E-L, the seal strength (N / 10 mm) at a test speed of 200 mm / min and a test temperature of 23 ± 1 ° C. was measured. Table 6 shows the evaluation results of the sealing properties.
[0032]
[Table 4]

[0033]
[Table 5]

[0034]
[Table 6]

[0035]
From the heat resistance evaluation results shown in Table 4, it is clear that Examples 1 to 5 have good heat resistance, and compared to Comparative Example 1, metallocene polyethylene (low density component (A) and medium density). It can be seen from Table 2 that only the component (B) polymer composition) or Ziegler polyethylene (component (C)) alone is insufficient in heat resistance. Further, when the melting point of the outer layer 3 or the inner layer 4 is lower than those of the comparative examples 5 and 7, it is apparent that a problem occurs in the appearance of the container.
[0036]
In the evaluation result of the moldability shown in Table 4, both the resin temperature and the resin pressure are higher in the metallocene polyethylene (the polymer composition of the low density component (A) and the medium density component (B)) than in Comparative Example 1. A high numerical value is shown, indicating that the moldability is insufficient. On the other hand, it can be seen from Comparative Example 2 that Ziegler polyethylene alone has good moldability. It is apparent that Examples 1 to 5 have good moldability due to the balance of metallocene polyethylene and Ziegler polyethylene. Further, when the blending balance of the polymer composition of the low density component (A) and the medium density component (B) is significantly biased on one side as in Comparative Example 5, the resin pressure increases and the moldability is lost. I understand that
[0037]
From the evaluation results of flexibility shown in Table 5, it is clear that Examples 1 to 5 have good flexibility. Further, from Comparative Example 4, when the blending amount of (B) or (C), which is a medium / high density component, is large, flexibility is lost. Further, from Comparative Example 6, high-density metallocene polyethylene and Ziegler polyethylene are used. It turns out that flexibility is lost.
[0038]
From the transparency evaluation results shown in Table 5, it is clear that Examples 1 to 5 have good transparency. From Comparative Examples 1, 5, and 7 in Table 4, it can be seen that when the heat resistance of the container is insufficient, the transparency is lost as shown in Table 5. Further, as in Comparative Example 2, it is clear that Ziegler polyethylene alone does not have sufficient transparency. Further, when the outer layer 3 is thick (50%) as in Comparative Example 3 or when the blending amount of (B) or (C) which is a medium / high density component is large as in Comparative Example 4 (40 or It can be seen that transparency is lost when metallocene polyethylene and Ziegler polyethylene having a high density (0.937 g / cm ³ ) as in Comparative Example 6 are used as well as 50 wt% and 90 wt% in both.
[0039]
From the evaluation results of bending fatigue resistance shown in Table 5, it is clear that Examples 1 to 5 have good bending fatigue resistance. Further, it can be seen that Ziegler polyethylene alone as in Comparative Example 2 does not have sufficient bending fatigue resistance. Further, when the outer layer 3 is thick as in Comparative Example 3, or when the blending amount of (B) or (C), which is a medium / high density component, is large as in Comparative Examples 1 and 4, or Comparative Example 6 It can be seen that bending fatigue resistance is lost when metallocene polyethylene and Ziegler polyethylene with high density are used.
[0040]
From the evaluation results of low temperature impact resistance shown in Table 6, it is clear that Examples 1 to 5 have good low temperature impact resistance. Further, it can be seen that Ziegler polyethylene alone as in Comparative Example 2 does not have sufficient low temperature impact resistance. When the outer layer 3 is thick as in Comparative Example 3, or when the blending amount of (B) or (C), which is a medium / high density component, is large as in Comparative Examples 1 and 4, or as in Comparative Example 6 It can be seen that low-temperature impact resistance is lost when high-density metallocene polyethylene and Ziegler polyethylene are used.
[0041]
From the evaluation results of the sealing strength shown in Table 6, it is clear that Examples 1 to 5 have good sealing properties. Moreover, when the thickness of the inner layer 3 is thin like the comparative example 3, or when there are few compounding quantities of (A) which is a low density component like the comparative example 4, it turns out that sealing performance is lost.
[0042]
[Effects of the invention]
As described above, the medical container 1 according to the present invention is excellent in balance of physical properties such as heat resistance, flexibility, transparency, low temperature impact resistance, bending fatigue resistance, heat sealability, and workability at the time of molding. In addition, since high-pressure steam sterilization is possible, it can be suitably used as an infusion container for storing a drug solution.
[Brief description of the drawings]
1 is a medical container 1 of the present invention.
FIG. 2 is a partially enlarged cross-sectional view of a laminate 2 constituting the medical container 1 of the present invention.
FIG. 3 is a schematic view showing an example of a method for producing a laminated resistance 2 constituting the medical container 1 of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Medical container 2 Laminated body 3 Outer layer 4 Inner layer 5, 6 Hopper 7, 8 Extruder 9 Multilayer die 10 Sizing ring 11 Stabilizing plate 12 Pinch roll 13 Take-up roll 14 Winding machine

Claims (1)

In the medical container in which the container body is composed of a laminate (2) composed of an inner layer (3) and an outer layer (4)
The outer layer (3) of the laminate (2) is formed from a linear low density polyethylene or ethylene-α-olefin copolymer polymerized using a metallocene catalyst having a density of 0.920 to 0.930 g / cm ^3. And
The linear low density polyethylene polymerized using the metallocene catalyst of the outer layer (3) or the ethylene-α-olefin copolymer has a melting peak temperature of 115 ° C. or higher as measured by a differential scanning calorimeter and an MFR of 1 to 10 g. / 10 minutes,
The inner layer (4) of the laminate (2) is
(A) a linear low density polyethylene or ethylene-α-olefin copolymer polymerized using a metallocene catalyst having a density of less than 0.890-0.920 g / cm ³ and (B) a density of 0.920-0. Polymerized with linear low density polyethylene or ethylene-α-olefin copolymer polymerized using a 930 g / cm ³ metallocene catalyst and (C) a Ziegler-Natta catalyst with a density of 0.910 to 0.930 g / cm ³ Formed from a polymer composition comprising a linear low density polyethylene or an ethylene-α-olefin copolymer,
The blending ratio of the components (A), (B) and (C) of the polymer composition constituting the inner layer (4) is (A) 40 to 75% by weight, (B) 5 to 30% by weight, (C) 10 to 40% by weight,
And the melting peak temperature by the differential scanning calorimeter of the polymer composition consisting of the components (A), (B) and (C) is 110 ° C. or higher, and the MFR is 1 to 10 g / 10 min.
The ratio of the thickness of the inner layer (4) to 65% to 85% of the total thickness of the laminate (2) is 100%,
The laminate (2) after high-pressure steam sterilization under conditions of a temperature of 110 ° C., a gauge pressure of 1.5 kgf / cm ² and a time of 30 minutes has the following characteristics (a) to (d):
(A) 5% secant elastic modulus is 200 MPa or less, (b) Haze is 15% or less, (c) Physical properties after performing bending fatigue operation 5000 times at room temperature by MIT fatigue resistance tester The rate of decrease with respect to physical properties is 10% or less, (d) Tensile impact strength of the seal portion is 500 kJ / m ² or more,
A medical container that can be sterilized by high-pressure steam and stores chemicals.

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