JP3080822B2 - Multilayer film and container - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer film and a container formed using the same. Specifically, it is used in the medical field, particularly for accommodating a drug solution, blood, or the like.

[0002]

2. Description of the Related Art In the prior art, there has been proposed a multilayer film and a container made of three layers, each of which is made of a sheet composed of a polyethylene resin. Tokuhei 3-3106
In 2), since the inner and outer layers are made of a low-density polyethylene resin, the heat resistance is not sufficient, and when subjected to high-temperature sterilization, the sealing strength and the drop strength of the bag are not sufficient. Similarly, a multilayer film and a container comprising three or four or more layers have been proposed (JP-A-4-40995).
6), the outermost layer was composed of a linear polyethylene resin, and although the heat resistance was improved as compared with the low-density polyethylene resin, it was still insufficient.

On the other hand, to increase the strength, a multilayer container provided with a polyamide resin layer has been proposed (JP-A-59-5959).
181164, JP-A-60-55958, JP-A-2-1
278). However, these are not satisfactory because of poor flexibility, poor production efficiency due to inability to raise the heat sealing temperature, and poor transparency.

Accordingly, an object of the present invention is to provide a multilayer film and container excellent in heat resistance, seal strength, blocking resistance, etc., which can solve the problems in the prior art.

[0005]

According to the present invention, there is provided, in accordance with the present invention, a film having a multilayer structure, comprising an outer layer comprising a heat-resistant polyamide resin layer from the outside, an adhesive resin layer, and a flexible polyolefin resin. The intermediate layer is laminated in the order of the inner layer of the anti-blocking polyolefin resin, and the polyamide resin is nylon 12
And / or nylon 6 and the adhesive resin is unsaturated carb
Acid-modified polyolefin, flexible polyolefin
Linear resin whose density is 0.920 g / cm ³ or less
・ It is an α-olefin copolymer and has a blocking resistance
The polyolefin resin has a density of 0.930 g / cm ³ or more.
Linear ethylene / α-olefin of less than 945 g / cm ³
It is characterized by being a copolymer.

[0006]

Further, in a preferred embodiment of the present invention, the outer layer has a two-layer structure of a nylon 6 layer and a nylon 12 layer, and the linear ethylene / α-olefin copolymer of the inner layer has a density of 0.945 g. / Cm ³ or more and 15% by weight or less of a high-density polyethylene, and an outer layer having a two-layer structure of a polyamide resin layer and a polypropylene layer.

In addition, according to the present invention, there is provided a medical container formed using the above-mentioned film.

[0009]

According to the above-mentioned multilayer film and container, (1) the outer layer needs to be selected from a polyamide resin having heat resistance (particularly, nylon 6 and / or nylon 12).
A ) a low-density (0.920 g / cm ³ or less) linear ethylene / α-olefin copolymer as the polyolefin resin having the flexibility of the intermediate layer;
The density is higher than the intermediate layer of a heat resistant polyolefin resin (0.930 g / cm ³ or more 0.945 g / cm ³
Less) By arranging a linear ethylene / α-olefin copolymer, a product that can withstand high temperatures during high-temperature sterilization was obtained. At the same time, the inner layer can have heat sealability, blocking resistance and chemical resistance.

(2) Since the resin having an adhesive property to the polyamide resin of the outer layer and the polyolefin resin of the intermediate layer is an unsaturated carboxylic acid-modified polyolefin, the bonding property can be improved. (3) By using a polyamide resin having high heat resistance and mechanical strength for the outer layer, heat resistance and mechanical strength can be increased, and the thickness of the entire laminate can be reduced. In addition, by placing a transparent, flexible linear ethylene / α-olefin copolymer in the intermediate layer,
Transparency and flexibility were obtained.

(4) A heat-resistant polyamide resin in the outer layer, a low-density, low-melting linear ethylene / α-olefin copolymer in the intermediate layer, and a density of 0.930 g / cm ³ or more and 0.945 g / cm ^{3 in the} inner layer. By forming a multilayer film having a linear ethylene / α-olefin copolymer of less than ³ cm ³ , it is possible to seal at a temperature higher than the thermal welding start temperature of the inner layer resin at the time of sealing, and the speed of bag making is increased. I got stuck.

(5) Since the layer structure of the film can be co-extruded, the manufacturing cost can be reduced by shortening the steps. Hereinafter, the present invention will be described more specifically. First, FIG. 1 shows a laminated film, in which 10 is an outer layer, 20 is an adhesive resin layer, 30 is a polyolefin resin to be an intermediate layer,
0 indicates an inner layer.

Here, the ethylene / α-olefin copolymer used as the polyolefin resin in the present invention is, for example, ethylene and propylene, 1-butene, 1-
Pentene, 1-hexene, 4-methyl-1-pentene,
3 to 12 carbon atoms such as 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, and 1-dodecene.
Can be exemplified.

Next, these laminated films will be described in more detail. <Outer layer> A polyamide resin is used because mechanical strength, heat resistance, and transparency are required. Examples of the polyamide include nylon 6, nylon 6.6, nylon 12, and nylon 612. Among them, with respect to high-temperature sterilization such as high-pressure steam sterilization or hot water sterilization, it shall be the hard nylon 6 and / or nylon 12 cause deterioration such as hydrolysis (see FIG. 2). In particular, a two-layer structure of nylon 6 and nylon 12 is more preferable. Incidentally, the outer layer may have a two-layer structure of a polyamide resin layer and a polypropylene resin layer,
In that case, the polypropylene layer is made the outermost (see FIG. 3). The thickness is preferably 5 to 40% of the whole. <Adhesive Resin Layer> For good adhesion between the polyamide resin of the outer layer and the flexible polyolefin resin (described later) of the intermediate layer, maleic acid, acrylic acid, itacone It is preferable to use a grafted acid. The thickness of the adhesive resin layer accounts for about 3 to 10% of the entire film. <Intermediate layer> A polyolefin resin having both high flexibility and transparency is provided. The polyolefin has a density of 0.920.
g / cm ³ or less, preferably 0.895 to 0.910
g / cm ³ of a linear ethylene / α-olefin copolymer is used. The thickness is preferably about 40 to 80% of the entire film. <Inner layer> An anti-blocking and heat-resistant polyolefin-based resin is provided to withstand sterilization under high temperature conditions, to prevent blocking, and to easily perform heat welding. Specifically, using the density <br/> 0.930 g / cm ³ or more 0.945 g / cm ³ less than the linear ethylene · alpha-olefin copolymer.

In order to increase the blocking resistance and the heat resistance, a high-density polyethylene having a density of 0.945 g / cm ³ or more can be mixed up to about 15% by weight. The thickness is preferably about 5 to 15% of the whole. <Production method of film> Examples of the production method of the film of the present invention include a water-cooled or air-cooled coextrusion inflation method, a coextrusion T-die method, a dry lamination method, and an extrusion lamination method. Water-cooled coextrusion inflation method and coextrusion T-die method are preferred from the viewpoints of economy, hygiene, and the like. In any of the methods, it is necessary to carry out the process at a temperature at which the resin of each layer is melted. However, if the temperature is too high, a part of the resin is thermally decomposed, and there is a possibility that the performance of the resin is reduced due to decomposition products.

Therefore, the temperature conditions for producing the film of the present invention are usually 150 to 250 ° C., preferably 160 to 24 ° C.
Desirably, it is 0 ° C. Further, the resin constituting each layer preferably has a difference in MFR (melt flow rate) as small as possible in order to maintain transparency. The thickness of the film of the present invention produced as described above is generally 100 to 30.
Although it is 0 μ, it can be increased or decreased as appropriate according to the purpose of use. For example, a thickness of about 100 μ has sufficient strength to be used as a medical container. <Manufacturing method of container> The tubular or sheet-like film obtained above is cut and heat-sealed by an ordinary method, and a mouth member or the like is attached by means such as heat sealing to manufacture a container having a predetermined shape and dimensions. I do.
The conditions for heat sealing the film are as follows:
Up to about 230 ° C., for example, 200 μ
In the case of films having different thicknesses, sealing can be performed in a short time of 0.5 to 3 seconds at a temperature of 200 to 220 ° C.

It is preferable that the mouth member is made of a linear low-density polyethylene, because it is well welded to the inner layer of the film of the present invention.

[0018]

Embodiments of the present invention will be described below.
First, a synthetic resin and a laminated sheet having a layer configuration shown in Table 1 were each formed by water-cooled co-extrusion by an inflation method. Next, a medical container having a content of 500 ml was molded using these. The film was heat-sealed at 210 ° C. for 1 second in forming the container.

Further, various characteristics of the obtained medical container were evaluated by the following methods. That is, the heat resistance is
After filling with the content liquid, high-pressure steam sterilization treatment was performed at 110 ° C. for 40 minutes, and then deformation, bag breakage, and seal leakage were visually observed. In the drop test, the state of bag breakage and seal leakage when the container was dropped from a height of 1.2 m five times in three directions after being refrigerated to about 4 ° C. was visually observed.

The flexibility was determined by visually observing the spontaneous discharge of the content liquid, and measuring the flexibility of the film with a loop stiffness tester (manufactured by Toyo Seiki Seisaku-sho, Ltd.). Here, the hardness in the film extrusion direction is represented by MD, and the flexibility in the radial direction of the film is represented by TD. The transparency was visually observed after filling with distilled water and performing high-pressure steam sterilization.
The light transmittance at 0 nm was measured.

In addition, visual observation of the overall appearance is performed,
The condition of wrinkles, blocking, deformation, and bag breakage was examined. still,
The abbreviations in Table 1 are as follows.・ NY-6 = Nylon 6 (manufactured by Ube Industries) ・ NY-12 = Nylon 12 (manufactured by Ube Industries) ・ AD = graft copolymer of polyethylene and maleic acid (Mitsui Petrochemical; trade name = Admer) ・ PE = Ethylene / 1-butene copolymer [Mitsui Petrochemical; density 0.905 g / cm ³ , MFR 2.86 g / 10 min (190
° C.)] - PE = 1-butene copolymer [made by Mitsui Petrochemical; density ^{0.900g / cm 3, MFR 0.90g /} 10 min (190
° C)]-PE = ethylene / 1-butene copolymer [manufactured by Mitsui Petrochemical; density 0.940 g / cm ³ , MFR 2.10 g / 10 min (190
° C)] · PE = ethylene / 1-butene copolymer [Mitsui Petrochemical; density 0.930 g / cm ³ , MFR 2.10 g / 10 min (190
° C)] and high-density polyethylene (ethylene / 1-butene copolymer) [manufactured by Mitsui Petrochemical; density 0.956 g / cm ³ , MFR
95: 5 mixture with 9.0 g / 10 min (190 ° C.)] PP = Polypropylene homopolymer [manufactured by Mitsui Petrochemical; density 0.910 g / cm ³ , MFR 11.0 g / 10 min (230
° C)], ◎ indicates very good, and ○ indicates good.

[0022]

[Table 1]

[0023]

The multilayer film and the container according to the present invention have the following effects. (1) It has excellent heat resistance and can withstand high-temperature sterilization such as high-pressure steam sterilization and hot water sterilization. (2) The anti-blocking property is improved, and it is easy to handle and durable.

(3) It is excellent in flexibility, and it is easy to maintain the content liquid storage state. (4) The transparency is excellent, and it is easy to determine the transparency of the content liquid. (5) Good overall bondability and excellent seal strength. (6) The speed of film production and bag making can be increased.

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional view of a layer structure of a film of the present invention of Examples Nos. 1 to 4.

FIG. 2 is an enlarged cross-sectional view of the layer structure of the film of the present invention of Examples Nos. 5 to 6.

FIG. 3 is an enlarged sectional view of a layer structure of the film of the present invention of Examples Nos. 7 to 10.

[Explanation of symbols]

 Reference Signs List 10 outer layer 11 outer NY-12 layer 12 outer NY-6 layer 13 outer polypropylene layer 14 outer NY-6 layer 20,21,22 adhesive resin layer 30,31,32 intermediate polyolefin resin 40,41 , 42 Inner layer

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-81168 (JP, A) JP-A-4-59244 (JP, A) JP-A-61-179737 (JP, A) 147660 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 1/00-35/00 B65D 65/00-65/46 A61J 1/10

Claims (6)

(57) [Claims] 1. A film having a multilayer structure, Yes are laminated in this order of the outer layer adhesive resin layer flexible polyolefin resin middle layer blocking resistance polyolefin resin inner layer made of a heat-resistant polyamide resin layer from the outside, a polyamide resin Is nylon 12
And / or nylon 6 and the adhesive resin is unsaturated carb
Acid-modified polyolefin, flexible polyolefin
Linear resin whose density is 0.920 g / cm ³ or less
・ It is an α-olefin copolymer and has a blocking resistance
The polyolefin resin has a density of 0.930 g / cm ³ or more.
Linear ethylene / α-olefin of less than 945 g / cm ³
A multilayer film characterized by being a copolymer . 2. An outer layer made of nylon 6 or nylon 12
The multilayer film according to claim 1, which is a layer of: 3. The multilayer film according to claim 1, wherein the outer layer has a two-layer structure of a nylon 6 layer and a nylon 12 layer. 4. The multilayer film according to claim 1, wherein the outer layer has a two-layer structure of a polyamide resin layer and a polypropylene layer. 5. The multilayer film according to claim 1, wherein a high-density polyethylene having a density of 0.945 g / cm ³ or more and 15% by weight or less are mixed with the linear ethylene / α-olefin copolymer of the inner layer. 6. A container formed by using the film according to claim 1.