JPH02231139A - Composite film - Google Patents

Abstract

PURPOSE:To improve resistance to steam sterilization of a polyethylene film and to prevent it from interlayer peeling by coating both faces of a polyethylene film each with a flexible polyvinyl chloride layer contg. no plasticizer. CONSTITUTION:A composite film is a five layered structure consisting of the first flexible polyvinyl chloride layer contg. no plasticizer 1, an adhesive layer 2, a polyolefin layer 3, an adhesive layer 4 and the second flexible polyvinyl chloride layer contg. no plasticizer 5 laminated in this order. As the polyolefin layer 3, a linear low density polyethylene is especially pref. The first and second flexible polyvinyl chloride layers contg, no plasticizer 1 and 5 contain a polyvinyl chloride resin and an ethylene-carbon monoxide-vinyl acetate copolymer and is formed with a resin compsn. contg. 35-65wt.% ethylene-carbon monoxide- vinyl acetate copolymer. When the content of ethylene-carbon monoxide-vinyl acetate copolymer is less than 35wt.%, flexibility and transparency is poor, and when it is above 65wt.%, stickiness unpreferably occurs at steam sterilization and blocking tends to occur.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a composite film suitably used for medical bags such as infusion bags and blood bags.

(Prior art) Medical bags such as infusion bags have traditionally been made from flexible plastic films, and such plastic medical bags are lighter and less susceptible to breakage than conventional glass containers. It has the advantage of being easy to handle, such as being difficult to use, and it also has the advantage of not requiring a suction hole to maintain the internal pressure of the container at the same level as atmospheric pressure during infusion, allowing for a so-called closed system. Therefore, flexible plastic infusion bags have recently come into widespread use.

By the way, the conditions required for the film used in such medical bags are: - Flexibility; - Heat resistance to withstand steam sterilization; - No elution from the film; - Heat resistance Good secondary processing properties such as seals and high-frequency seals are also mentioned.

Film materials conventionally used for this type of medical bag include polyethylene, polybropylene, crosslinked ethylene-vinyl acetate copolymers, and soft polyvinyl chloride.

(Question B to be solved by the invention) However, when a medical bag is made of polyethylene film, it has poor steam sterilization properties, and when a medical bag is made of polypropylene film, it has poor flexibility, and ethylene vinyl acetate When a bag is made from a copolymer film, it has poor secondary processability, and when a bag is made from a soft polyvinyl chloride film, there are many eluted substances.

Therefore, the present inventors developed a film for medical bags.
By using a composite film made by laminating a soft polyvinyl chloride film and a polyethylene film, it is possible to improve steam sterilization, which is a drawback of polyethylene film, and at the same time, improve the drawback of soft vinyl chloride film, which is that there are many eluates. However, this composite film has the disadvantage that the plasticizer in the soft polyvinyl chloride film bleeds out during steam sterilization, resulting in peeling between the eyebrows.

The present invention has solved the above-mentioned drawbacks, and its purpose is to provide a composite film that can satisfy each of the above-mentioned requirements as a material for medical bags.

(Means for Solving the Problems) The present invention is capable of improving the steam sterilization resistance of a polyethylene film and preventing delamination by coating both sides of the polyethylene film with a plasticizer-free soft polyvinyl chloride layer. The present invention was completed based on this knowledge.

That is, the composite film of the present invention includes a first plasticizer-free soft polyvinyl chloride layer, an adhesive layer, a polyolefin layer, an adhesive layer, and a second plasticizer-free soft polyvinyl chloride layer. A composite film laminated in this order, wherein the first and second plasticizer-free soft polyvinyl chloride layers contain a vinyl chloride resin and an ethylene/carbon monoxide/vinyl acetate copolymer, It is made of a resin composition having an ethylene/carbon monoxide/vinyl acetate copolymer content of 35 to a5ffiffi%, thereby achieving the above object.

As shown in FIG. 1, the composite film of the present invention comprises a first non-plasticized soft polyvinyl chloride layer 1, an adhesive layer 2, a polyolefin WA3, an adhesive layer 4, and a second non-plasticized polyvinyl chloride layer. The flexible polyvinyl chloride layer 5 is laminated in this order to form a five-layer structure.

The polyolefin layer 3 may be formed of linear low density polyethylene (LLDPE), low density polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid, etc. Especially preferred is linear low density polyethylene (LLDPE).

The adhesive layers 2 and 4 can be formed of one type selected from the following adhesives, or a mixture of two or more types.

■Vinyl acetate/ethylene copolymer (vinyl acetate content 3
5~Jll) Contribution %, melt flow rate (MFR, A
STM D 1238) 1 dg/min or higher).

■Chlorinated polyethylene (chlorine content ffi20~4off
iffi%) ■ Ethylene/carbon monoxide/vinyl acetate copolymer (carbon monoxide content ffi 3-20%, vinyl acetate content flLO - 40ffi 1%) ■ Ethylene/carbon monoxide/ (meth)acrylic acid alkyl ester (monocarbon monoxide) (carbon oxide content: 5 to 30% by weight, (meth)acrylic acid alkyl ester content: ffixo to 40% by weight) the first and second non-plasticized soft polyvinyl chloride layers 1;
5 contains a 1-nyl chloride resin and an ethylene/carbon monoxide/vinyl acetate copolymer;
It is formed from a resin composition containing 35 to 65% by weight of vinyl acetate copolymer.

If the content of the ethylene/carbon monoxide/vinyl acetate copolymer is less than 35% by weight, flexibility and transparency will be poor, which is not preferable. If the content of the ethylene/carbon monoxide/vinyl acetate copolymer exceeds asffiffi%, it is not preferable because it becomes sticky during steam sterilization and tends to cause flocking.

Plasticizer-free soft vinyl chloride resin is generally obtained by melt-mixing vinyl chloride resin and ethylene/carbon monoxide/vinyl acetate copolymer, but those obtained as follows can also be used. Can be done.

■The so-called ethylene/carbon monoxide/vinyl acetate copolymer obtained by radical polymerization of vinyl chloride alone or a monomer that can be copolymerized with vinyl chloride in the presence of an ethylene/carbon monoxide/vinyl acetate copolymer. Polymerized vinyl chloride graft polymer.

This vinyl chloride graft polymer was
It can be produced according to the method described in JP-A No. 876 and JP-A-56-139518.

■Add ethylene/carbon monoxide/vinyl acetate as a plasticizer to the vinyl chloride graft polymer of the ethylene/carbon monoxide/vinyl acetate copolymer.
It may be a mixture of a carbon monoxide/vinyl acetate copolymer, or it may be a mixture of the vinyl chloride graft polymer and the vinyl chloride polymer.

Examples of the vinyl chloride resin include a polymer of polyvinyl chloride alone, or a copolymer of vinyl chloride and one or more of ethylene, propylene, vinyl acetate, (meth)acrylic acid ester, etc. .

The ethylene/carbon monoxide/vinyl acetate copolymer is a copolymer of ethylene, carbon monoxide, and vinyl acetate.

In this ethylene/carbon monoxide/vinyl acetate copolymer,
Ethylene in an amount of 40 to 80% by weight, preferably 60 to 70% by weight, carbon monoxide in an amount of 5 to 30% by weight, preferably 5 to 20% by weight, and vinyl acetate in an amount of 1O to 60fI.
It is desirable that it is contained in an amount of ffi%, preferably 10 to 40% by weight, and it is also possible to further copolymerize other monomers as necessary.

To produce such an ethylene/carbon monoxide/vinyl acetate copolymer, the monomers ethylene, carbon monoxide,
The monomers may be copolymerized by supplying each of the vinyl acetates together with a catalyst at a predetermined ratio into a high-speed stirring reaction vessel, mixing the mixture, and stirring at high speed under high temperature and high pressure.

This ethylene/carbon monoxide/vinyl acetate copolymer has a melt flow rate (MFR, ASTM D1238) of 1 to 500 g/to, preferably 10 to 50 g/1G.
Preferably, it is within minutes.

In addition to the above-mentioned vinyl chloride resin and ethylene/carbon monoxide/vinyl acetate copolymer, the above-mentioned plasticizer-free soft vinyl chloride resin contains conventionally known non-toxic additives used for medical device applications. , for example, calcium stearate, zinc stearate, epoxidized soybean oil, di-n-octyltin compound, tris(nonylphenyl)phosphite, and the like.

This plasticizer-free soft vinyl chloride resin is made by combining the above-mentioned vinyl chloride resin, ethylene/carbon monoxide/vinyl acetate copolymer, and additives such as stabilizers and lubricants as necessary, by rolling or bumper-coating. It is obtained by melt-blending using a batch kneader such as a mixer or a continuous kneader such as a twin-screw extruder.

The above five-layer composite film can be continuously manufactured by extrusion molding or the like, and by making bags from this composite film, medical bags such as infusion bags and blood transfusion bags are manufactured. To make a medical bag, for example,
The plasticizer-free soft polyvinyl chloride layers 1 or 5 are fused together by overlapping a pair of composite films and high-frequency sealing or heat sealing the connected portions.

In the composite film of the present invention, the total thickness of the film is 200 to 500 mm in order to ensure flexibility and transparency.
The thickness of the polyolefin layer 3 is preferably 30 to 80% of the total film, and the thickness of each of the plasticizer-free soft polyvinyl chloride layers 1 and 5 is preferably 10 to 30% of the total film. In addition, the thickness of the adhesive layers 2 and 4 is 5 to 1 mm of the entire film.
0% is preferred. Plasticizer-free soft polyvinyl chloride layers 1 and 5
If the thickness of the film is less than 10% of the entire film, steam sterilization will be reduced, and if it exceeds 30%, it will be uneconomical.

Therefore, by coating both sides of the polyolefin layer 3 with the non-plasticized soft polyvinyl chloride layers 1 and 5, the steam sterilization resistance of the polyolefin layer 3 such as polyethylene can be improved, and the When a soft polyvinyl chloride film is used, the plasticizer in the soft polyvinyl chloride film bleeds out during steam sterilization, making it impossible to integrate it with other materials, such as polyethylene film. However, in the present invention, by selecting an appropriate adhesive layer, it can be composited with a polyolefin film such as polyethylene without any problem. The composite film of the present invention thus obtained can be steam sterilized under these conditions, whereas conventional polyethylene films cannot withstand steam sterilization at 121"C for 20 minutes. It has good flexibility and secondary processability, and also shows good results in the eluate test based on the test method for plastic containers for infusions.

(Example) Hereinafter, the present invention will be explained in detail based on examples.

Sharp JLLL Ethylene content is 4% by weight and average degree of polymerization is 1.300
100 parts by weight of vinyl chloride/ethylene copolymer (measured according to JIS X 6721), ethylene/carbon monoxide/
Vinyl acetate copolymer (carbon monoxide content ffiloff amount%, vinyl acetate content 24% by weight) 1001! quantity,
10 parts by weight of epoxidized soybean oil, lllffi parts of Ca-Zn stabilizer (Mark 37, manufactured by Adeka Argus), and lfljl parts of oxidized polyethylene wax (Hiwax 4202E, manufactured by Mitsui Petrochemicals) were heated at 170°C for 5 minutes using two rolls. The mixture was kneaded for a minute to obtain a plasticizer-free vinyl chloride resin.

After cutting this into square pellets, the first
A second plasticizer-free soft polyvinyl chloride layer is extruded with a gap, and at the same time, a linear low-density polyethylene (Mitsui Petrochemical Co., Ltd., Ultzex 10) is extruded between these two layers.
30L) to extrude the polyolefin layer, and
Between each layer is an ethylene/vinyl acetate copolymer (vinyl acetate content 40% by weight, melt index M+-2.O
dg/min), and then each layer was laminated and integrated to obtain a composite film with a thickness of 300 μm.

In the obtained composite film, the thickness of the first and second plasticizer-free soft polyvinyl chloride layers is 50 μm, the thickness of both adhesive layers is 20 μm, and the thickness of the polyolefin layer is 160 μm.
It was a garden.

The results of the plastic infusion container test of the obtained composite film were good as shown in Table 1.

Furthermore, when an infusion bag with a capacity of 500 ml was produced using this composite film by a high-frequency sealing method, the infusion bag was flexible and had good transparency. next,
Approximately 400 ml of physiological saline was sealed in this infusion bag, and the bag was steam sterilized at 121"C for 20 minutes. As a result, no abnormalities such as fusion, deformation, or delamination of the infusion bag were observed.

An infusion bag is made of a composite film made by laminating Aisango soft polyvinyl chloride film (a film whose main components are 100'!ijl parts of polyvinyl chloride (average degree of crosslinking 1400) and 55 parts by weight of dioctyl phthalate) and polyethylene film. When this infusion bag was produced and steam sterilized in the same manner as in Example 1, the plasticizer bled onto the surface and delamination was observed.

(Effects of the Invention) The structure of the composite film of the present invention is as described above; it is transparent, flexible, can be steam sterilized, has no leachables, and has excellent secondary processability. It can be suitably used as a medical bag such as an infusion bag or a blood transfusion bag.

4. Figure 1 is a sectional view of a composite film according to an embodiment of the present invention.

1... First plasticizer-free soft polyvinyl chloride layer, 2...
- Adhesive layer, 3... Polyolefin layer, 4... Adhesive layer, 5... Second plasticizer-free soft polyvinyl chloride layer.

that's all

Claims (1)

[Claims] 1. The first non-plasticized soft polyvinyl chloride layer, the adhesive layer, the polyolefin layer, the adhesive layer, and the second non-plasticized soft polyvinyl chloride layer in this order. A composite film laminated with polyvinyl chloride, wherein the first and second plasticizer-free soft polyvinyl chloride layers contain a vinyl chloride resin and an ethylene/carbon monoxide/vinyl acetate copolymer; - A composite film formed from a resin composition having a carbon monoxide/vinyl acetate copolymer content of 35 to 65% by weight.