JP3052398B2 - Medical bag - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical bag for filling blood, chemicals, etc., having excellent hygiene, flexibility, transparency and heat resistance. More specifically, the present invention relates to a medical bag made of a sheet composed of three or more layers or four or more layers, each layer being composed of a polyethylene resin or a composition thereof, which is hygienic, flexible, and transparent. Another object of the present invention is to provide a medical bag that is filled with blood, a drug solution, and the like having excellent heat resistance.

[0002]

2. Description of the Related Art At present, a hard container made of glass, polyethylene, polypropylene or the like and a soft bag made of polyvinyl chloride containing a plasticizer are known as medical containers. However, in the former method, air must be introduced using a ventilation needle or an infusion set having a ventilation hole when the content liquid is dropped. In addition, contamination of the content liquid occurs. on the other hand,
The latter does not require the introduction of air, and has safety such as the bag itself being squeezed by the atmospheric pressure when the content liquid is dripped, and has convenient transportation. However, there are problems such as the toxicity of the plasticizer and residual monomers contained in polyvinyl chloride.

On the other hand, a medical bag using a polymer such as an ethylene-vinyl acetate copolymer or an elastomer for an intermediate layer has been proposed in view of flexibility, transparency, hygiene, and the like (Japanese Patent Application Laid-Open No. Sho-59-28139). No. 58-165866), however, these polymers used for the intermediate layer have poor heat resistance, so that there is a problem that a medical bag with poor appearance such as a wrinkled state of the bag during sterilization is obtained. From these, some of the present inventor, the results of various searches for medical bags to be filled with hygiene, flexibility, transparency, blood with excellent heat resistance, etc. It has been found that a medical bag made of a sheet whose layer is composed of a polyethylene resin satisfies the above-mentioned characteristics and has been proposed previously (Japanese Patent Application Laid-Open No. 62-44).
No. 256, No. 62-64363).

[0004]

SUMMARY OF THE INVENTION The above-mentioned JP-A-62-44
In the invention described in Japanese Patent No. 256, the outer and inner surface layers are made of a low-density polyethylene resin produced using a radical catalyst (the intermediate layer is a linear low-density polyethylene resin). For this purpose, if the contents of the medical bag are treated with, for example, high-pressure steam at 120 ° C. for the purpose of sterilizing the contents, the heat resistance is not always satisfactory because the outer surface layer is composed of a low-density polyethylene resin. Was. For example, if the high-pressure steam is treated for 20 minutes, the sealing strength of the bag is not sufficient, and the drop strength is not satisfactory. Moreover, it is not sufficient in terms of flexibility and transparency, and there is some deformation.

Further, in the invention described in Japanese Patent Application Laid-Open No. 62-64363, all the layers are made of linear polyethylene resin. The linear polyethylene resin is manufactured using a so-called Ziegler catalyst. Therefore, there is a concern that trace amounts of titanium and aluminum present in the linear polyethylene resin constituting the inner surface layer may exude into the contents (medical solution, blood, etc.) filled in the medical bag in some cases. In addition, there is a problem that fine particles increase due to calcium stearate added for neutralizing halogen atoms (generally, chlorine atoms) constituting the catalyst system. Therefore, a step of removing the catalyst system is necessary to almost completely remove the catalyst system remaining in the linear polyethylene resin, and even if the catalyst system is removed, a satisfactory effect is exhibited. Difficult to do.

In order to solve these problems, some of the present inventors have proposed in Japanese Patent Application No. 2-149488 a method capable of withstanding high-pressure steam sterilization at 120 ° C. by improving the composition of the inner and outer layers. I came. By this method, a medical bag that can sufficiently withstand high-pressure steam sterilization at 120 ° C. for 20 minutes was obtained. However, it has been found that there is a problem in the stability of film formation, that is, the uniformity of quality in the cooling stage of the molten bubble when the composition is continuously operated for a long time commercially with this composition formula. That is, by using 50% or more of the linear polyethylene resin for the outer surface layer, the melt elasticity of the molten film is reduced, the crystallization speed is increased, and uniform cooling becomes difficult, and the elasticity after crystallization is large. Stable molding became difficult because the properties affected the molten film.

[0007] From the above, the present invention is a further high temperature 12
Even if sterilized by high-pressure steam at 1 ° C. for 20 minutes, there is almost no deformation, little decrease in seal strength and drop strength, and flexibility and transparency are maintained. It is another object of the present invention to provide a medical bag capable of performing stable molding.

[0008]

According to the present invention, there is provided a medical bag made from a laminated film, sheet or tube comprising three or more layers.
Low density polyethylene resin inner and outer layers is obtained by density 0.930 g / cm ³ or less radical polymerization method, a density of 0.945 g / cm ³ or more and an Mw / Mn 4.0
A low-density polyethylene resin comprising a composition containing 5 to 40% of the following high-density polyethylene resin, wherein the intermediate layer has a short-chain branch having a density of 0.920 g / cm ³ or less;
The density is 0.945 g / cm ³ or more and Mw / Mn is 4.
The problem can be solved by a medical bag comprising a composition containing at most 15% of 0 or less high density polyethylene resin.

Hereinafter, the present invention will be described specifically. The low-density polyethylene obtained by a radical polymerization method of 0.930 g / cm ³ or less used in the present invention is generally produced by polymerizing ethylene under high pressure (usually 700 to 3000 kg / cm ² ), It is industrially manufactured as a high pressure polyethylene resin. The MFR of the resin is from 0.1 to 10 g / 10 min, preferably from 0.2 to 8.0 g / 10 min, more preferably from 0.1 to 10 g / 10 min.
3 to 5.0 g / 10 min is preferred. The density is 0.91
0 to 0.930 g / cm ³ , 0.915 to 0.9
28 g / cm < ³ > is preferable, especially 0.918-0.
927 g / cm ³ is preferred. The density is 0.910g /
If the size is less than ³ cm ³ , the obtained medical bag is deformed during high-pressure steam sterilization, and undesirably causes wrinkles.

When the density is 0.945 g / cm ³ or more, M
High-density polyethylene having w / Mn of 4.0 or less is a polyethylene resin having a linear structure produced by homopolymerization of ethylene or copolymerization of ethylene and an α-olefin. The resin has a density of 0.945 to 0.970 g
/ Cm ³ and preferably 0.950～0.965G / cm ^3, especially 0.952～0.960G / cm ³
Is preferred. The MFR of the resin is 0.1 to 20 g / 10 min, preferably 0.2 to 10 g / 10 min, and more preferably 0.3 to 5.0 g / 10 min. A major feature of this resin is that it exhibits a molecular weight distribution and Mw / Mn (Mw: GP
The weight average molecular weight determined by C and Mn: the number average molecular weight determined by GPC) must be small, that is, the molecular weight distribution needs to be narrow. When Mw / Mn exceeds 4, the transparency of films, sheets and the like is significantly deteriorated. Mw / Mn is 4.0 to 2.2, preferably 3.8 to 2.2, and more preferably 3.5 to 2.2.

Further, the polyethylene resin having a density of 0.920 g / cm ³ or less used in the present invention has a branch number of 20 to 70 per 1000 carbon atoms in the main chain and a density of 0.890 to 0.990 g / cm ^3. 0.920 g / cm ³ . Further, the MFR is 0.1 to 10 g / 10 minutes. Moreover, the peak of the melting point measured by DSC appears at 110 to 125 ° C. The number of short-chain branches per 1000 carbon atoms in the main chain is 20 to 70, preferably 30 to 70, and more preferably 35 to 70. Main chain carbon number 1
A polyethylene resin having less than 20 branches per 000 is inferior in flexibility when formed into a film or sheet, and is not preferred as the medical bag of the present invention. On the other hand, more than 70 are currently not commercially produced. Also, the density is 0.890 ~ 0.920g
/ Cm ³ , preferably 0.890 to 0.915 g / cm ³ , especially 0.890 to 0.910 g / cm ³
cm ³ is preferred. 0.890 g / cm ³ density
Less than polyethylene resin is not currently commercially produced. On the other hand, if the amount exceeds 0.920 g / cm ³ , the flexibility when formed into a film or a sheet is poor, which is not preferable as the medical bag of the present invention. Further, the MFR is 0.1 to 10 g / 10 min, and 0.2 to 1 g / min.
0 g / 10 min is preferable, and especially 0.3 to 5.0 g / min.
10 minutes is preferred.

[Sheet and Method for Producing the Same] To produce the medical bag of the present invention, first, a film or sheet comprising the above-mentioned layers is produced. This film or sheet may be tubular. In the sheet of the present invention,
The polyethylene resin used to form each layer requires that each layer have the composition described above. The density in these compositions is 0.945 g / cm ³ or more and Mw
The ratio of the high-density polyethylene resin having a / Mn of 4.0 or less is preferably 5 to 40% in the case of the inner and outer layers, and particularly preferably 10 to 37%. In the case of the intermediate layer, the content is desirably at most 15%. In the case of the inner and outer layers, when the proportion of the high-density polyethylene is 5% or less, the heat resistance is insufficient and the appearance after retorting at 121 ° C. for 30 minutes causes difficulty. On the other hand, if it exceeds 40%, the molding stability in long-term continuous production will be poor. In the case of the intermediate layer, if it exceeds 15%, the heat resistance is improved, but the transparency and flexibility are lowered, and the molding stability is also deteriorated.

The thickness of the film or sheet of the present invention is generally 0.10 mm to 0.80 mm as a whole.
It is preferably from 15 to 0.70 mm, especially from 0.15 to 0.70 mm.
50 mm is preferred. If the thickness of the film or sheet as a whole is less than 0.10 mm, the impact strength is weak, and there is a practical problem. On the other hand, if it exceeds 0.80 mm, the flexibility is remarkably reduced and the practicality as a medical bag is poor.

The ratio of the thickness of each layer of the film sheet is generally 5: 90: 5 to 30:40:30 when comparing the outer surface layer / intermediate layer (including multilayer) / inner surface layer. , 5: 90: 5 to 25:50:25 is preferable, and 5: 90: 5 to 20:60:20 is particularly preferable. When the outer surface layer and the inner surface layer are less than the lower limits, the heat resistance of the obtained medical bag is not good (20 ° C.
If sterilized for a minute, it may be deformed). on the other hand,
If the upper limit is exceeded, the flexibility of the obtained medical bag is inferior and there is a practical problem.

To produce the film or sheet of the present invention, a water-cooled or air-cooled coextrusion inflation method,
A co-extrusion T-die method, a dry lamination method, an extrusion lamination method and the like can be mentioned, but from the viewpoints of economy and hygiene of medical bags, the co-extrusion inflation method and the co-extrusion T-die method are preferred.

[Medical Bag and Production Thereof] The film or sheet obtained as described above or a tube-like material thereof is applied to a general bag by the method carried out for producing a bag. The medical bag of the present invention can be manufactured by making a bag to a size and attaching a pouring inlet (plug).

[0017]

The present invention will be described in more detail with reference to the following examples and comparative examples. In Examples and Comparative Examples,
The density is 23 ° C. ± according to the method D of JIS K7112.
It was measured at a temperature of 0.1 ° C. The flexibility is AS
The Young's modulus was measured according to TMD-882. Transparency was evaluated by a haze measured according to ASTM D-1003 method after filling the contents with a high-pressure steam sterilization treatment at a temperature of 121 ° C. for 30 minutes. Furthermore, the evaluation by appearance was shown by the following three ranks. ：: good. Δ: Wrinkles or shrinkage occurred. X: Shrinkage occurred and the shape was deformed. Next, the moldability was evaluated by water-cooled three-layer, three-layer co-extrusion inflation molding, and indicated by the following three ranks. ：: The bubbles are stable and stable molding is easy. Δ: The bubble is unstable and the shear is likely to enter. ×: Bubbles are very unstable and continuous molding is difficult.

Examples 1 to 6, Comparative Examples 1 to 8 Low density polyethylene (abbreviated as LDPE), high density polyethylene (abbreviated as HDPE) and linear low density polyethylene (abbreviated as L-LDPE) having the densities shown in Table 1. ), Each composition component having a different ratio in each of the two combinations is previously used for 5 minutes using a Henschel mixer, and each obtained mixture is used at a resin temperature of 180 ° C. using a single screw extruder (screw diameter 65 mm). While kneading, a pellet-shaped composition was produced. Next, these compositions are shown in Table 1.
Were formed by a water-cooled three-layer, three-layer coextrusion inflation molding machine so as to form an outer layer, an intermediate layer, and an inner layer at the respective thicknesses shown in Table 1. A medical bag having an inner volume of 500 ml was manufactured from the laminate thus obtained, and the evaluation was performed as described above. Table 2 shows the obtained results.
Shown in

[0019]

[Table 1]

[0020]

[Table 2]

As is clear from these Examples and Comparative Examples, only medical bags manufactured using a laminate composed of a composition in a specific composition range have transparency, flexibility,
The appearance after the retort treatment at 121 ° C. was excellent, and good results were obtained in the continuous moldability.

[0022]

The medical bag of the present invention is excellent not only in transparency and flexibility but also in continuous molding, and can be used at 121 ° C3.
Even a 0 minute retort treatment shows sufficient heat resistance and is useful as a medical bag for high-temperature sterilization.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-44256 (JP, A) JP-A-62-64363 (JP, A) JP-A-58-165866 (JP, A) 40956 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) A61J 1/10 B32B 27/32

Claims (1)

(57) [Claims] 1. A medical bag made from a laminated film, sheet or tube comprising three or more layers,
A low-density polyethylene resin whose inner and outer layers have a density of 0.930 g / cm ³ or less obtained by a radical polymerization method is combined with a high-density polyethylene resin having a density of 0.945 g / cm ³ or more and Mw / Mn of 4.0 or less. made from a composition comprising 40%, the intermediate layer is a density 0.920 g / cm ³ or less linear low density polyethylene copolymer to a density 0.945 g / cm ³ or more and Mw / Mn with a short chain branching A medical bag comprising a composition containing at most 15% of a high-density polyethylene resin of 4.0 or less.