JPH06209981A - Basic member for medical container - Google Patents

Abstract

PURPOSE:To provide a basic member for a medical container which is suitably used for the manufacture of the medical container which possesses the excellent balance between the softness, transparency, and heat resistance, and in particular can suppress the generation of pockmarks on the outer surface even after the application of high pressure steam sterilization. CONSTITUTION:A basic member for a medical container is a laminated body having the first layer made of linear low density polyethylene and the second layer consisting of a polymer composition consisting of high density polyethylene and low density polyethylene, and the second layer forms the outermost layer of the laminated layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bag for storing liquids used in the medical field, such as blood and liquid pharmaceuticals, and a medical container containing a tube for carrying such liquids. The present invention relates to a suitable medical container base material.

[0002]

2. Description of the Related Art Safety, hygiene, etc. are required for a base material constituting a medical container such as a bag used in the medical field such as blood collection, blood transfusion, and liquid transfusion, and flexibility, transparency and high-pressure steam sterilization are required. It is required to have heat resistance to the extent possible.
As a material for such a base material, in addition to soft polyvinyl chloride resin, polyethylene such as low-density polyethylene and ethylene-vinyl acetate copolymer have been mainly used.

However, the soft polyvinyl chloride resin has drawbacks such that it is difficult to elute and dispose of the plasticizer, and the coloring (yellow) easily occurs. Further, polyethylene can change its flexibility, transparency and heat resistance by changing its density, but it is very difficult to balance these three in good condition. Although low-density polyethylene has excellent flexibility and transparency, it has a low melting point and thus has poor heat resistance, and cannot withstand high-pressure steam sterilization (usually performed at 100 to 130 ° C.), and avatars are easily generated on the surface. It has been pointed out that the ethylene-vinyl acetate copolymer is superior in transparency and flexibility to the ordinary low density polyethylene containing no vinyl acetate component, but is also inferior in heat resistance. Further, linear low-density polyethylene has relatively good heat resistance, and has high flexibility and transparency,
Still, it is not sufficient as a constituent material for the above-mentioned bag or the like.

In order to optimize the linear low density polyethylene, for example, Japanese Patent Application Laid-Open No. 61-290954 describes the application of linear low density polyethylene having a specific density and Olsen rigidity. 62-133959 describes the application of a mixture of linear low density polyethylenes of different densities. Further, JP-A-62-44256 describes a medical container in which the inner layer and the outer layer are made of a relatively high density linear low density polyethylene and the intermediate layer is made of a lower density linear low density polyethylene. Japanese Patent Application Laid-Open No. 63-248633 discloses a medical container having a substantially similar three-layer structure. However, even if the density of the base material is limited and the number of layers is increased, the transparency,
At present, it is difficult to satisfy both flexibility and heat resistance.

Polypropylene, which has higher heat resistance than polyethylene, is also widely used in the production of bags and the like, but it has poor flexibility and its use is limited. Polybutene-1 having relatively good flexibility
Has insufficient transparency as a substrate for medical containers.

[0006]

Therefore, the present invention has a good balance of flexibility, transparency and heat resistance.
In particular, it is an object of the present invention to provide a medical container base material suitable for manufacturing a medical container, in which avatars are not generated on the outer surface even when subjected to high-pressure steam sterilization.

[0007]

The above object can be achieved by the present invention described in (1) below.

(1) A laminate having a first layer made of linear low density polyethylene and a second layer made of a polymer composition of high density polyethylene and low density polyethylene, wherein the second layer Is a layer forming the outermost layer of the laminated body.

The present invention will be described in detail below.

The first layer in the present invention is composed of linear low density polyethylene (A). This linear low-density polyethylene (A) is a so-called ethylene-α-olefin copolymer, and is a mixture of ethylene with a small amount of propylene, butene-1, octene-1, decene-1,4-methylpentene-. 1 to 10 mol% of α-olefin, etc.,
More preferably, it is obtained by copolymerizing 2 to 8 mol% by a low pressure method or an intermediate pressure method. Its density, 0.905~0.935g / cm ³ approximately in consideration of the flexibility and transparency, and more preferably about 0.910~0.930g / cm ^3. Also, temperature 190 ℃, load 2.16
Melt flow rate (MFR) at 0 g is 0.1
It is preferably 10, and more preferably 0.5 to 5.0.

The second layer in the present invention is composed of a polymer composition (D) with high density polyethylene (B) and low density polyethylene (C).

The high density polyethylene (B) used in the present invention is a polyethylene having a density of 0.940 g / cm ³ or more, and is usually obtained by a low pressure method. The density is 0.942 to 0.960 in consideration of flexibility and transparency.
It is preferably about g / cm ³ . Also, the temperature 19
The melt flow rate (MFR) at 0 ° C. and a load of 2.160 g is 0.1 to 10, and more preferably 0.5 to.
It is preferably 5.0.

The low density polyethylene (C) used in the present invention has a density of less than 0.940 g / cm ³ , so-called low density polyethylene which can be produced by a usual high pressure method, and the above linear low density polyethylene. Similar to (A),
Both the linear low-density polyethylene obtained by copolymerizing the above α-olefin are included, but the density is preferably higher than that of the low-density polyethylene (A). The higher the density, the higher the heat resistance, but on the contrary, the rigidity becomes high and the flexibility decreases, so the density is 0.920 to 0.938 g /
cm ³ is preferable, and 0.925 to 0.
It is preferably 935 g / cm ³ . Also, temperature 1
The melt flow rate (MFR) at 90 ° C. and a load of 2.160 g is 0.1 to 0.1 in consideration of moldability and mechanical properties.
It is preferably 10, and more preferably 0.5 to 5.0.

Polymer composition (D) used in the present invention
Is a polymer composition comprising the high-density polyethylene (B) and the low-density polyethylene (C). The composition ratio depends on the transparency, flexibility and heat resistance required in the application and sterilization conditions, but the weight ratio of the high density polyethylene (B) and the low density polyethylene (C) is 8
0: 20-10: 90, more preferably 70: 30-
It is preferably about 15:85. The higher the proportion of high-density polyethylene (B), the better the heat resistance of the obtained base material and the effective suppression of avatar generation on the container surface during high-pressure steam sterilization, but the flexibility and transparency of the entire container. In consideration of the above, the above ratio is appropriately adjusted in the production process of the polymer composition (D).

The polymer composition (D) is obtained, for example, by mixing the above-mentioned high-density polyethylene (B) and low-density polyethylene (C) in a predetermined ratio in a kneading extruder or static mixing in an arbitrary step before molding. It can be produced by melt blending using a machine.

By comprising such a polymer composition (D), the second layer has good heat resistance. The medical container substrate of the present invention is a laminate having a first layer and a second layer, further characterized in that the second layer forms the outermost layer of the laminate. It is what By using such a laminate, the medical container substrate of the present invention effectively exhibits heat resistance, and is a well-balanced substrate having good flexibility and transparency. That is, when the medical container is produced, the second layer, which is the outermost layer of the base material, can be disposed so as to be the outer surface of the container, so that the flexibility and transparency can be effectively exhibited, and the container It is possible to impart heat resistance to the outer surface and prevent avatars from being generated on the outer surface during high-pressure steam sterilization.

In the present invention, the "outermost layer" is the outermost layer of two or more layers constituting the laminate,
The outer layer refers to a layer that forms an outer surface when the laminated body has a shape such as a container shape or a tube shape having an inner surface and an outer surface.

The thicknesses of the first layer and the second layer are appropriately set in consideration of the transparency, flexibility, heat resistance, strength, gas barrier property and the like required for the use of the base material. You can Generally, the total thickness of the substrate is 50 to 1000 μm.
m, more preferably 80 to 800 μm, and the thickness of the second layer is 5 to 100 μm, more preferably 8 to 80 μm.
It is preferable that The thicker the second layer is, the higher the heat resistance is, which effectively suppresses the generation of surface avatars in high-pressure steam sterilization, but the higher the rigidity, the higher the heat resistance is, the second layer is required. When the transparency and flexibility are important, the first layer may be relatively thick.

The medical container substrate of the present invention has at least a first layer and a second layer, and the second layer may form the outermost layer thereof. In addition to the two-layer structure of the above, a layer of the same linear low-density polyethylene (A) as the first layer and a layer of the same polymer composition (D) as the second layer were alternately arranged. It also includes a laminate having three or more layers, or a configuration having one or more layers made of a material different from the linear low density polyethylene (A) and the polymer composition (D).

The medical container substrate of the present invention is composed of the same polymer composition (D) as the second layer, and is disposed on the opposite side of the first layer from the side on which the second layer is disposed. In the case of a three-layer structure with a third layer, when a medical container is made using this base material, not only the outer surface of the container but also the inner surface is covered with a layer with good heat resistance, so high pressure steam sterilization is performed. Is effective against. The thickness of each layer in such a configuration may be appropriately set as in the case of only two layers, but preferably the thickness of each of the first, second and third layers is 50 to 1000 μm.
About 5 to 100 μm, about 5 to 100 μm, about 80 to 800 μm, about 8 to 80 μm,
It is preferably about 8 to 80 μm.

The medical container substrate of the present invention may be in a non-stretched state or a stretched state, and the surface thereof is roughened so that the produced container does not cause blocking (fusion). It may be subjected to (embossing) treatment, or may contain a slip agent, an antiblocking agent, or the like. Further, other polymers, plasticizers, inorganic fillers, stabilizers and the like may be added to the base material of the present invention to the extent that the transparency, flexibility and heat resistance of the base material are not impaired.

The medical container substrate of the present invention comprises, for example, pellets composed of each of the linear low density polyethylene (A) and the polymer composition (D), at a temperature above the flow starting point temperature, preferably Is 170 to 220 ° C., more preferably 175 to 210 ° C., the polymer composition (D)
T for multi-layer extrusion so that the second layer consisting of is the outermost layer.
A flat sheet, a tubular sheet, a parison or the like can be obtained by extrusion molding through a die or a tubular die for multilayer extrusion. In this case, in order to suppress crystallization of the obtained base material, it is preferable to cool the casting roller or the base material to be extruded with water or the like at the time of extrusion.

In the present invention, the term "medical container" is used in the medical field such as whole blood, plasma preparations, concentrated red blood cell preparations, or other liquids derived from blood or liquid medicines such as physiological saline or infusions. Includes containers for storing liquids as well as tubes for carrying such liquids.

The medical container of the present invention is characterized by comprising the above-mentioned medical container base material of the present invention, and the above-mentioned second layer being disposed on the outer surface thereof. As described above, since the second layer having good heat resistance is arranged at least on the outer surface of the container which easily causes avatars by high-pressure steam sterilization, the medical container of the present invention has a good balance of flexibility, transparency and heat resistance. Therefore, even if high-pressure steam sterilization is performed, avatars do not occur on the outer surface.

The medical container of the present invention has a third layer composed of the same polymer composition (D) as the second layer on the side opposite to the side where the second layer is arranged. When it is composed of a base material with a three-layer structure, the layer with good heat resistance is placed not only on the outer surface of the container but also on the inner surface, so it is more effective in generating avatars by high-pressure steam sterilization. Can be prevented.

In the production of the medical container of the present invention, a flat sheet, a tubular sheet, a parison or the like made of the base material of the present invention is used, and the second layer made of the polymer composition (D) is placed outside. Thus, it can be carried out by appropriately selecting or combining means such as thermoforming, blow molding, cutting, and heat fusion, and processing into a predetermined size and shape. When manufacturing a tube, it is usual to form the substrate into a tube shape by extrusion molding.

During or after the production of the container, for example, the inner surface or the outer surface of the container is subjected to a roughening (embossing) treatment so that the container does not cause blocking (fusion), and a slip agent or blocking is prevented. An agent or the like may be contained, and further, another polymer, a plasticizer, an inorganic filler, a stabilizer or the like may be contained to the extent that the transparency, flexibility and heat resistance of the substrate are not impaired.

[0028]

EXAMPLES The present invention will be described in more detail below with reference to examples.

[Examples 1 to 7 and Comparative Example 1] (1) Preparation of sheet and evaluation thereof Polymer used: pellets of the polymer shown in Table 1 below were used. The polymer composition (D) is produced by melting and mixing the high-density polyethylene (B) and the low-density polyethylene (C) at 180 ° C. using a melt type twin-screw extruder,
The obtained strand was water-cooled, cut and dried.
The MFR of each polymer was measured at a temperature of 190 ° C. and a load of 2.1.
It was carried out at 60 kg.

[0030]

[Table 1]

Preparation of Substrate (Sheet): From the polymer pellets obtained in the above, a substrate (sheet) of the present invention was prepared as shown below. The polymer combinations in the respective Examples and Comparative Examples are shown in Table 2 below.

The two types of pellets were melted by using an extruder to obtain a lip length of 400 mm and a lip width of 0.
Supplied to a 2mm / 2 layer T-die of 8mm, 180-190 ℃
After being extruded into a sheet shape with, and cooled with a casting roller kept at 15 ° C., trimming was performed and a sheet having a thickness of 350 μm and a width of 300 mm was wound at a speed of 6 m / min.

Measurement of Physical Properties of Sheets: For the evaluation of transparency of each sheet obtained in the above, the transmittance in water at a wavelength of 450 mm was measured by a double beam type automatic spectrophotometer (UV-300: manufactured by Shimadzu Corporation). ).
Also, each sheet is cut into a dumbbell shape, and JIS K71 is used.
According to No. 13, the tensile modulus was measured to evaluate the flexibility.

Heavy metal and eluate test: According to the Japanese Pharmacopoeia general test method “Plastic container test method for infusion”,
A test was conducted on each sheet obtained in 1.

(2) Preparation of container and its evaluation Preparation of container: 150 mm of each sheet prepared in (1)
It was cut into a size of 250 mm, two layers were superposed so that the layer composed of the polymer composition (D) was on the outside, and heat-sealed to produce the container of the present invention.

800 ml of physiological saline was put into each of these containers, and the container was sealed, put in a retort type high-pressure steam sterilizer, and heat-treated at a temperature of 110 ° C. and a gauge pressure of 1.8 kg / cm ² for 40 minutes. After cooling to room temperature, the presence or absence of avatars generated on the outer surface of the container was observed after 48 hours.

The results are shown in Table 2.

[0038]

[Table 2]

(3) Experimental Results Extrusion molding of the sheet was successful, and no troubles such as the generation of foreign matter or foaming were observed in any composition, and a sheet having high uniformity was obtained.

It was observed that heavy metals and eluates were compatible with the Japanese Pharmacopoeia in any composition.

As shown in Table 2, Comparative Examples 1-2 to 5
The sheets of Nos. 7 to 7 have many avatars on their outer surfaces due to high-pressure steam sterilization, and have poor heat resistance.
It was observed that No. 4 had no avatar, but the transparency was relatively insufficient. On the other hand, in each of Examples 1 to 8, the transparency and flexibility of the linear low-density polyethylene were not impaired, and no avatar on the outer surface was observed. From this, it was found that the base material and container of the present invention had an excellent balance of transparency, flexibility and heat resistance, and were suitable as a base material for medical containers and a medical container.

[0042]

As described above in detail, a laminate having a first layer made of linear low density polyethylene and a second layer made of a polymer composition of high density polyethylene and low density polyethylene is provided. The base material for a medical container of the present invention, wherein the second layer forms the outermost layer of the laminate, has excellent balance of transparency, flexibility and transparency, and is molded. It has good properties, can be suitably used as a material for medical containers such as bags and tubes, and has high productivity, so that it has a high industrial value.

Claims (1)

[Claims] 1. A laminate having a first layer made of linear low-density polyethylene and a second layer made of a polymer composition of high-density polyethylene and low-density polyethylene, wherein the second layer A layer for a medical container, wherein the layer forms the outermost layer of the laminate.