JP2003192017A - Composite film for aseptic packaging - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite film suitable or aseptic filling packaging of an automatic bag-making system which is sterilized with a hydrogen peroxide aqueous solution. <P>SOLUTION: The composite film for hydrogen-peroxide aseptic packaging comprises a laminated film in which a heat-fusion layer is provided on the inside of a stretch base-material film layer. A protective film comprising a layer of bridged ethylene polymeric resin film is superposed on the outside of the stretch base-material film layer. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a composite film suitable for automatic aseptic continuous aseptic filling packaging for foods, pharmaceuticals and the like.

[0002]

2. Description of the Related Art In order to prevent the contents filled in a plastic sealed bag from being altered and deteriorated during storage, or to extend the storage period, the contents are sterilized and sterilized with microorganisms to be filled.

As a method of sterilizing the filled contents,
The retort sterilization method in which the contents are once sealed and filled in a plastic film under a high temperature and pressure of about 120 ° C for a relatively long time, and the boiling sterilization method in which the contents are heated and sterilized in hot water at 100 ° C or less A hot pack method of pre-heating and filling the bag with the contents that are still heated and sterilizing and sterilizing the microorganisms attached to the film by the heat.
There is a sterilization method in which the contents are heat-treated at a high temperature for a short time and the sterilized contents are separately filled into a sterilized film.

As the latter method of separately sterilizing the contents and the microorganisms of the film and filling them, the contents are sterilized indirectly by continuously passing the contents through a tube, a plate or a scraping type sterilizer. Generally, a method of sterilizing by heating at a high temperature for a short time, and a method of sterilizing by heating by blowing heated steam directly on the contents are common.

As a sterilizing method of the film, the film is irradiated with ionizing radiation such as ultraviolet rays, γ rays or electron beams to perform non-heat sterilization in batch type or continuous type, and the film is continuously fed in a sterile chamber. However, there is a method of chemically sterilizing microorganisms such as a method of immersing in a high-concentration heated hydrogen peroxide aqueous solution, a method of spraying an aqueous hydrogen peroxide solution, or a method of immersing in a peracetic acid or hypochlorous acid aqueous solution.

The method of filling the aseptic film with the sterilized contents under the aseptic atmosphere packaging machine is called commercial aseptic packaging, which is free from food poisoning bacteria and pathogenic bacteria and decomposes and decomposes under normal temperature distribution. It means that there are no microorganisms that cause economic loss, and milk, fruit juice drinks, wine, yogurt, etc. filled in paper carton containers and bottles have been put to practical use.

On the other hand, although the microbial level does not reach the level of commercial sterilization, a package that is sterilized to extend the storage period by refrigerating in a refrigerator or the like is called sterilized packaging, which is called boil sterilization. This is hot pack sterilization packaging.

[0008] In recent years, consumers have come to recognize the importance of sterilized packaging as the pursuit of genuine taste for foods, the demand for safety, individual consumption of foods, simplification, etc. are increasing. That is, in commercial aseptic packaging, since the contents are sterilized at high temperature in a short time, compared to the conventional sterilization by the retort method, there is less change in taste due to alteration of the contents, the original taste of food is maintained, and As a result, the safety is assured against accidents such as food poisoning due to spoilage bacteria caused by alteration of the contents because of the aseptic sterility.

Of these, an aqueous solution typified by hydrogen peroxide has a strong sterilizing power and is highly reliable, and therefore has a track record of sterilizing packaging materials for commercial aseptic packaging.

As a film for packaging liquid contents, a composite film in which a heat-fusible film is laminated on a polyamide base film is generally used to prevent bag breakage. When used as a film for aseptic filling according to the above, not only is hydrogen peroxide incorporated into a polyamide-based film, it is difficult to remove it to a high level by drying, and not only hydrogen peroxide may remain. However, the polyamide film itself may be deteriorated by the oxidizing action of hydrogen peroxide. Therefore, in order to protect the polyamide-based film from hydrogen peroxide, another protective film is laminated on the outer layer of the polyamide-based film.

The function required of the protective film is as follows.
First, it is chemically stable against hydrogen peroxide and is difficult to adsorb hydrogen peroxide. Especially when the operation of the filling and packaging machine is temporarily stopped due to some trouble or rest,
The film will stay in the hydrogen peroxide solution heated to a temperature of about 50-60 ° C for a long time, and if the film deteriorates with hydrogen peroxide and becomes weak in that case, it will be overheated for a long time when restarted. The film in the portion immersed in the hydrogen aqueous solution may be cut.

In the continuous bag-making type aseptic filling machine, the filling machine chamber is kept in a sterile atmosphere by keeping the internal pressure slightly positive, so that when the film is cut, the seal at the film chamber outlet collapses and the outside air becomes aseptic chamber. It will flow into the interior and destroy the sterile atmosphere. In that case, it takes several hours to sterilize the inside of the chamber again, which significantly affects productivity.

The second required function is excellent filling machine suitability. That is, in a bag-making type aseptic filling machine, it is necessary to dry the film in the filling machine chamber in order to sufficiently remove the hydrogen peroxide solution adhering to the film immersed in the hydrogen peroxide solution. Since the drying is performed immediately before the former for folding the film into a tubular shape, the sailor is heated and a warm film is introduced.

The outermost protective film is formed into a tubular shape while changing its direction by directly contacting the former and rubbing strongly at the edge of the sailor. At this time, if the sliding friction resistance between the edge of the former and the film is large, Since a strong tensile tension is applied to the film, the film is cut, meandered, or the bag pitch is shortened, so that stable filling cannot be performed.

The temperature of the sailor gradually rises due to the heat carried in by the film as the operation continues, and at a certain temperature, it becomes a constant temperature in which heating and heat dissipation are well balanced, but in this state where the film and the former are heated, the film It is necessary that the friction resistance be small, that is, the hot slip property be good.

The protective film made of a crosslinked ethylene-based polymer resin film used in the present invention is not likely to be softened even when a temperature is applied because the polymer molecules are crosslinked, or the sailor in a heated state. Sliding property with does not deteriorate.

The third required function is to prevent pinholes from being generated in the distribution process of the finished filling bag. The filling bag is subject to impacts, rubbing against the corrugated cardboard, bending of the film, and the like during the distribution process, and pinholes are easily generated. However, it is necessary to prevent this, that is, to have excellent pinhole resistance. In particular, when the outermost protective film rubs directly against the corrugated cardboard and is bent, the largest bending stress is applied, which strongly affects the pinhole resistance. This pinhole resistance is likely to be a problem particularly when the bag has a large capacity, the fluidity of the contents is high, or the temperature is low.

As a method for improving the pinhole resistance, for example, Japanese Patent Publication No. 6-55469 discloses a composite film made of polyethylene having a slip coefficient as an outer layer and having a specific friction coefficient and a thickness. 27654
No. 5 discloses a composite film in which a non-stretched polyethylene layer or a non-stretched polypropylene layer is laminated as an outer layer, and JP-A-8-323937 proposes a composite film in which a polyolefin-based film protective layer is laminated as an outer layer. However, when these composite films are soaked in a heated aqueous hydrogen peroxide solution for a long time, they are likely to be chemically deteriorated, and when the operation is restarted, the slipperiness of the film in the dipping part of the film deteriorates and the film is wound on a feed roll. It may be attached or cut by the former part, and there is a problem as a composite film in which the film is sterilized with an aqueous hydrogen peroxide solution.

Further, in JP-A-6-155682 and JP-A-6-155683, there is disclosed a polyethylene-based crosslinked stretched film having a degree of crosslinking reduced in the thickness direction of the film as an outer layer in order to improve resistance to pinholes. Although it is proposed to stack, there is no suggestion of suitability for the hydrogen peroxide aqueous solution according to the present invention, and conventional bag-making type continuous sterilization having pinhole resistance, hydrogen peroxide resistance, and mechanical suitability at the same time. There was no proposal as a composite film for filling and packaging.

[0020]

SUMMARY OF THE INVENTION An object of the present invention is to provide a flexible composite film suitable for commercial aseptic packaging using this hydrogen peroxide solution and having excellent pinhole resistance. That is, the present invention, the packaging film in a hydrogen peroxide solution or peracetic acid solution or a mixed solution thereof,
It is an object of the present invention to provide an automatic bag-making type continuous aseptic filling and packaging composite film suitable for sterilizing fungi attached to a film by passing the aqueous solution of sodium hypochlorite or a spray atmosphere of the aqueous solution.

[0021]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventor has reached the composite film for aseptic packaging of the present invention.

That is, the present invention provides (1) a laminated film in which a heat-sealing layer is provided as an inner layer of a stretched base film layer, and an ethylene polymer resin cross-linked to the outer layer of the stretched base film layer. A composite film for hydrogen peroxide sterilization and aseptic packaging, characterized in that a protective film made of a film is laminated, (2) the stretched base film layer is a biaxially stretched polyamide-based film or a biaxially stretched polyester-based film. (1) The composite film for hydrogen peroxide sterilization and aseptic packaging according to (1) above, and (3) the stretched base film layer is a gas-barrier biaxially stretched polyamide-based film. The composite film for hydrogen peroxide sterilization aseptic packaging according to 4), and (4) the gas-barrier biaxially stretched polyamide-based film are added to the biaxially stretched polyamide-based film with vinyl chloride. A film coated with a redene resin, a film obtained by vapor-depositing a thin film of an inorganic oxide or a metal on a biaxially stretched polyamide film, a biaxially stretched coextruded polyamide containing a polyamide resin layer and an ethylene-vinyl alcohol copolymer resin layer. Hydrogen peroxide according to the above (3), wherein the hydrogen peroxide is selected from any of a biaxially stretched coextruded polyamide film including a polyamide film and a polyamide resin layer and a metaxylylene adipamide resin layer. Composite film for sterilization and aseptic packaging, (5) Intermediate film layer laminated between stretched base film layer and cross-linked ethylene polymer resin film or between cross-linked ethylene polymer resin film and heat fusion layer The composite film for hydrogen peroxide sterilization and aseptic packaging according to any one of (1) to (4) above, wherein ) Ethylene polymer resin films crosslinked, density from 0.900 to 0.9
Low 55 g / cm ^3, in the, characterized in that high-density polyethylene or a density 0.900~0.945g / cm ³ of linear low density polyethylene or mixtures thereof, or co-extrusion thereof The composite film for hydrogen peroxide sterilization aseptic packaging according to any one of (1) to (5).

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The composite film for aseptic filling of the present invention will be described with reference to the drawings. 1 and 2 are cross-sectional views of the composite film 1 of the present invention. The composite film 1 of FIG.
Is composed of a cross-linked ethylene-based polymer resin film 2 as the outermost layer, a stretched base film 3, and a heat-sealing layer 4 as the innermost layer.

A biaxially stretched film such as a polyolefin resin, a polyamide resin, or a polyester resin is used for the stretched base film layer 3, but it is flexible from the viewpoint of the biaxially stretched polyethylene terephthalate film and the pinhole resistance. A biaxially stretched polyamide film obtained by biaxially stretching a polyamide-based resin film having properties and toughness is preferable.

Examples of the polyamide resin include nylon 6, nylon 66, nylon 12, a mixture of these resins and an aromatic metaxylylene adipamide, and a coextruded product. The thickness of the film is , 5-40μ
m, preferably 10 to 30 μm.

In the case of contents which particularly require a gas barrier property for storage, a polyamide-based film having a gas barrier property is used as the stretched base film layer 3, or FIG.
The fourth film having the gas barrier property as described above is laminated as the intermediate film layer 5.

In FIG. 2, the intermediate film layer 5 is located between the crosslinked ethylene polymer resin film 2 and the stretched base film layer 3, but the stretched base film layer 3 and the heat-sealing layer 4 are separated from each other. It may be located in between.

The gas-barrier biaxially stretched polyamide film includes a nylon film laminated with a polyvinylidene chloride layer, a gas barrier layer such as a coextruded multilayer nylon film containing an ethylene vinyl alcohol layer, and an aromatic metaxylylene adipamide. A mixed or co-extruded multilayer nylon film or a biaxially stretched polyamide-based film provided with a thin film of a metal or an inorganic oxide is used.

As the gas barrier intermediate film layer 5, a polyester or polyolefin film laminated with a polyvinylidene chloride layer, a polyester or polyolefin film provided with a thin film of a metal or an inorganic oxide,
Examples thereof include ethylene-vinyl alcohol-based films, polyvinylidene chloride-based films, ethylene-vinyl alcohol, coextrusion films containing a polyvinylidene chloride layer, and metal foils.

A film having these functions, for example, a uniaxially stretched film or the like can be laminated as the intermediate film layer 5 in accordance with a request other than the gas barrier property, for example, a request such as imparting rigidity or linear cutting property. . The thickness of these intermediate film layers 5 is preferably 5 to 40 μm.

The protective film 2 made of a crosslinked ethylene polymer resin film is laminated on the outer surface of the stretched base film layer 3, that is, the outermost layer. The crosslinked ethylene-based polymer resin film 1 is extruded in a molten state from a T-die or an annular die using polyethylene of various densities, and rapidly cooled with a liquid medium such as water to form an unstretched sheet or tube raw fabric. To do.

Next, this unstretched raw material is irradiated with ionizing radiation such as electron rays and γ rays to crosslink the resin, and then the tube is heated by heat transfer with hot air or radiant heating with an infrared heater. It is obtained by biaxially stretching at a temperature not higher than the melting point of the coalescence.

As the ethylene-based polymer resin, a high density resin is used.
Polyethylene, medium density polyethylene, low density polyethylene
Copolymerizable with ethylene, linear low density polyethylene, ethylene
For example, a copolymer with another vinyl compound is used. Echire
The density of the polymer resin is 0.900 to 0.950 g /
cm³Although the ones used are preferably 0.910
0.940 g / cm³Is. Density is 0.900g / c
m³If it is smaller, the hydrogen peroxide resistance of the film deteriorates.
In addition, slipperiness is also reduced. Density 0.950g / cm ³Yo
If it is too large, it becomes difficult to form the film uniformly and stably.

The ethylene polymer resin film may be a single layer film of the above polymers alone or a mixture thereof, or may be a multilayer coextrusion film of the above polymers. The degree of cross-linking of the cross-linked ethylene-based polymer resin film changes depending on the degree of irradiation of ionizing radiation, and is indicated as the gel fraction by the proportion of insoluble matter by boiling para-xylene extraction.The higher the gel fraction, the higher the degree of crosslinking. . The degree of radiation is 20 to 100 kilogray, preferably 40 to 70 kilogray.
It is a kilogray. The degree of crosslinking of the ethylene polymer resin film of the present invention is 25 to 65% in terms of gel fraction, and preferably 30 to 55%.

The stretched base film layer 3 and the protective film 2 made of a cross-linked ethylene polymer resin film are laminated by a polyurethane adhesive, for example, a one-component isocyanate system, a two-component polyester-isocyanate system, 0.5 to 7 g of polyether-isocyanate adhesive
/ M ² Preferably, a dry lamination method in which a coating amount of ^{2 to 5} g / m ² is used for lamination, or an anchor coating agent, for example, a one-component isocyanate system having a coating amount of 0.5 to 1.5 g / m ² , Two-component polyester-isocyanate system,
It is made by a sand lamination method in which a polyolefin-based resin extruded from a T-die is laminated through a polyether-isocyanate-based polyurethane anchor coating agent.

A polyolefin polymer resin is used for the heat-sealing layer 4 laminated on the inner layer of the stretched base film layer 3. Specifically, ethylene-based polymer resin, for example, low-density polyethylene, linear low-density polyethylene, a copolymer with a vinyl compound copolymerizable with the ethylene-based resin, and the like,
A propylene polymer resin is used.

It is important to be careful in selecting the heat-sealing layer used for the aseptic filling film which is sterilized by hydrogen peroxide, in consideration of general required characteristics such as sealing property, heat resistance, rigidity and transparency. It is natural to select it, but in addition to this, consider residual hydrogen peroxide, for example, use a non-porous anti-blocking agent that does not easily adsorb hydrogen peroxide as an additive, or reduce the amount of anti-blocking agent added. It is necessary to separately consider such things as making it happen.

That is, the composite film 1 is sterilized by immersing it in a high-concentration aqueous hydrogen peroxide solution or spraying the aqueous hydrogen peroxide solution. Depending on the type and amount of slip agent, anti-blocking agent, etc. added to the fusing layer 4, the contacted hydrogen peroxide is adsorbed by them and the hydrogen peroxide is removed at a safe level even in the drying step. Therefore, it is necessary to consider it separately because there is a possibility that it may be mixed in the filling contents though it cannot be removed. The thickness of the heat-sealing layer 4 varies depending on the type of contents, the filling amount, etc.
Those having a size of about 0 to 100 μm are used.

The stretched base film layer 3 and the heat-sealing layer 4 are laminated in the same manner as the stretched base film layer 3 and the protective film 2 by laminating two films using a polyurethane adhesive. Extrusion of polyolefin resin from lamination method or T-die
In addition to the sand lamination method of laminating a plurality of films, there is an extrusion lamination method of laminating a molten heat-fusible resin layer 4 extruded from a T-die on a stretched base film 2 via an anchor coating agent. Next, the present invention will be described based on examples.

[0040]

BEST MODE FOR CARRYING OUT THE INVENTION The measuring methods in the examples are based on the following methods. "Gel Fraction" Based on ASTM-D2765, the gel fraction was defined as the weight fraction of insoluble matter in boiling paraxylene for 12 hours. "Density" It was measured by ASTM-D1505. "Single unit drop test" The total number of drops until the bag is broken by alternately dropping 5 bags in total in a 10 ° C atmosphere from a height of 120 cm so that the length or width of the bag is downward. Measure up to 100 times.

[Vibration test] Two filling bags are arranged side by side in a cardboard box, and four bags are placed on each of the filling bags, that is, 10 bags in two rows and five stages are packed, and an amplitude is measured by a shaking tester in an atmosphere of 15 ° C. Three
It vibrates horizontally under the conditions of 0 mm and a frequency of 165 times / min.
In the test, the vibration was temporarily stopped every 10 minutes to check if the bag was broken. If there was a broken bag, the bag was removed and the vibration test was continued for up to 60 minutes. . There are two types of vibration, one is when the vibration direction is parallel to the longitudinal direction of the bag, and the other is when the vibration is parallel to the lateral direction of the bag. , Short-side vibration test.

[0042]

EXAMPLES were mixed at a ratio of 8/2 to the low density polyethylene of Example 1 Density 0.925 g / cm ³ of linear low density polyethylene and a density 0.930 g / cm ³ in a weight ratio of melt from the circular die It was extruded and quenched using water as a liquid refrigerant to obtain an unstretched tube. The resulting unstretched tube is irradiated with an electron beam of 50 Kgray accelerated at an accelerating voltage of 500 KV for cross-linking treatment, followed by radiant heating with an infra heater to heat the unstretched tube, and the machine is operated according to the speed ratio between two nip rolls. Stretched in the flow direction of the machine, stretched at right angles to the machine's flow direction by injecting air into the tube, then applied cold air to the maximum diameter part of the bubble formed by the air ring to cool and fix the stretch, then folded. Folds up and has a thickness of 15μ
m, a crosslinked ethylene-based polymer resin film having a gel fraction of 40% was obtained.

The obtained film was slit into a width of 540 mm, and a biaxially stretched nylon 6 film having a thickness of 15 μm and corona-treated on both sides was laminated with a two-component polyester / isocyanate urethane adhesive.

Then, using a similar adhesive, a linear low-density polyethylene film made by Tama Poly Co., Ltd. having a thickness of 70 μm was attached to the other side of the biaxially stretched nylon 6 film, and the total thickness including the adhesive was included. A three-layer laminated composite film having a thickness of 108 μm was obtained.

This composite film was slit into a width of 330 mm, and a vertical pillow type aseptic packaging and filling machine ONPACK KAF2000 manufactured by ORIHIRO Co., Ltd. was used to form a folding width of 150 m.
A pillow bag having a size of m × 300 mm in length was filled with 1 kg of water. At this time, the composite film was attached to the composite film by passing it through a 35% concentration aqueous peroxide solution tank heated to 60 ° C. installed in the aseptic chamber of the filling machine for 1 minute and then blowing sterile air. After blowing off the hydrogen peroxide aqueous solution, it was dried with aseptic heated air at 80 ° C., folded in a cylinder with a former and vertically sealed and filled with 1 kg of water, but it could be filled smoothly without any problem.

Separately from this, in order to investigate the resistance to hydrogen peroxide when the film stays in the hydrogen peroxide aqueous solution for a long time, the composite film is stopped for 3 hours and stays in the hydrogen peroxide aqueous solution which remains overheated. After 3 hours, the operation was started again, but there was no trouble in the area where the hydrogen peroxide solution was stagnant, and there was no problem passing through the areas where the film was strongly rubbed, such as the stainless former and the guide plate for spreading the film. The steady filling was resumed.

In the drop test of 5 bags of the filling bag alone, the 5 bags were not broken even if they were dropped 100 times. In the case of vibration in the longitudinal direction of the bag, no bag was broken even after 60 minutes of vibration. If the bag vibrates in the lateral direction, after 30 minutes, 40 minutes,
After 50 minutes, a total of 3 bags were broken, one for each bag.

Comparative Example 1 For comparison, a biaxially stretched ethylene-based polymer film having a thickness of 15 μm and obtained in the same manner as in Example 1 except that the crosslinking treatment with an electron beam was not performed, had the same thickness as in Example 1. 15
A biaxially stretched nylon 6 film having a thickness of 70 μm and a linear polyethylene film having a thickness of 70 μm were attached to each other to obtain a composite film having a total thickness of 108 μm including the adhesive thickness.

This film was passed through a heated hydrogen peroxide aqueous solution tank for 1 minute in the same manner as in Example 1 and filled with 1 kg of water, but the running property of the film in the filling machine could be filled without any problem. , When the operation is restarted after staying in the heated hydrogen peroxide solution for 3 hours to check the resistance to hydrogen peroxide, the film is cut and filled when the film is soaked for 3 hours when the film part passes through the former. The sterile atmosphere in the chamber was broken, and it took 3 hours to sterilize the chamber again.

In the drop test of 5 bags alone, all the bags were broken by dropping within 50 times in total. Also, in the longitudinal vibration of the bag, 2 bags were broken after 10 minutes and 3 bags were broken after 20 minutes, and 3 bags were broken in 10 minutes and 3 bags were broken after 20 minutes.
The test was stopped at 0 minutes.

Example 2 A linear low-density polyethylene having a density of 0.932 g / cm ³ was extruded from a circular die in the same manner as in Example 1 and an electron beam 50 accelerated into an unstretched tube at an acceleration voltage of 500 KV.
After irradiation with kilogray, it was radiantly heated by an infra heater and subjected to inflation stretching to obtain a crosslinked ethylene polymer resin film having a thickness of 20 μm and a gel fraction of 42%.

A 12 μm thick polyethylene terephthalate film was formed on the aluminum vapor-deposited side of a 15 μm-thick biaxially stretched nylon 6 film obtained by vapor-depositing aluminum separately prepared by using a two-component polyester / isocyanate-based polyurethane adhesive. A linear low-density polyethylene film having a thickness of 50 μm was attached to the side opposite to the vapor deposition surface.

Then, a total thickness of 109 μm including the adhesive thickness of a four-layer laminate was obtained by using the same polyurethane adhesive as the above-mentioned crosslinked polyethylene polymer resin film having a thickness of 20 μm on the polyethylene terephthalate film surface of this laminated film. A composite film of

This composite film was slit into a width of 330 mm and filled with 1 kg of water in the same manner as in Example 1, but it could be filled without any particular problem. Also, the operation could be restarted without any problems in the 3 hour stagnation test in the heated hydrogen peroxide solution.

The drop test of 5 bags of the filling bag alone was tested, but the 5 bags did not break even if they were dropped 100 times in total in the vertical and horizontal directions. In the longitudinal vibration test of the bag, no bag was broken after 60 minutes of vibration, and in the lateral vibration test, one bag was broken after 40 minutes and 50 minutes.

Comparative Example 2 For comparison, a three-layer laminated composite film having a total thickness of 86 μm including the same adhesive thickness as in Example 2 except that the outermost cross-linked ethylene polymer film was not used was obtained. In the same manner as in Example 1, this film was retained in the heated hydrogen peroxide aqueous solution tank for 1 minute and filled with 1 kg of water, but it could be filled without any problem. Further, there was no problem in restarting the operation after staying in the heated aqueous hydrogen peroxide solution for 3 hours.

In the drop test of 5 bags each of which is a single filled bag, the bag was broken by dropping within 30 times in total in the vertical and horizontal directions. In the longitudinal vibration test for bags, 2 bags after 10 minutes and 2 bags after 20 minutes
The bag was ruptured one bag after 30 minutes, so the test was stopped in 30 minutes. In the transverse vibration, 4 bags were broken in 10 minutes and 3 bags were broken in 20 minutes, so the test was stopped in 20 minutes.

[0058]

The composite film of the present invention is excellent in chemical stability against hydrogen peroxide, running property of the filling machine and pinhole resistance.

[Brief description of drawings]

FIG. 1 is a schematic enlarged cross-sectional view showing a layer structure of a composite film of the present invention.

FIG. 2 is a schematic enlarged cross-sectional view showing the layer structure of another embodiment of the composite film of the present invention.

[Explanation of symbols]

1 composite film 2 protective film 3 Stretched base film layer 4 Thermal fusion layer 5 Intermediate film layer

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3E086 AB02 AC07 AD01 AD30 BA04                       BA15 BA24 BA33 BA40 BB55                       BB74 BB85 CA01 CA11 CA12                       CA23 DA01                 4F100 AA17D AK01A AK04C AK05C                       AK06C AK16D AK41A AK46A                       AK63C AK68D AL05C AR00B                       BA03 BA10B BA10C EH20C                       EH66D EJ05C EJ37A GB15                       JA13C JC00 JD02A JL12B

Claims (6)

[Claims] 1. A laminated film in which a heat-sealing layer is provided as an inner layer of a stretched base film layer, and a protective film made of a crosslinked ethylene-based polymer resin film is laminated on an outer layer of the stretched base film layer. A composite film for hydrogen peroxide sterilization aseptic packaging, which is characterized in that 2. The composite film for hydrogen peroxide sterilization and aseptic packaging according to claim 1, wherein the stretched base film layer is a biaxially stretched polyamide film or a biaxially stretched polyester film. 3. The composite film for hydrogen peroxide sterilization aseptic packaging according to claim 1, wherein the stretched base film layer is a gas barrier biaxially stretched polyamide film. 4. A gas-barrier biaxially stretched polyamide film is a biaxially stretched polyamide film coated with vinylidene chloride resin, and a biaxially stretched polyamide film is vapor-deposited with an inorganic oxide thin film or a metal thin film. Film, biaxially stretched coextruded polyamide film containing polyamide resin layer and ethylene-vinyl alcohol copolymer resin layer, biaxially stretched coextruded polyamide film containing polyamide resin layer and metaxylylene adipamide resin layer The composite film for hydrogen peroxide sterilization and aseptic packaging according to claim 3, which is selected from any one of the following. 5. An intermediate film layer is laminated between the stretched base film layer and the crosslinked ethylene-based polymer resin film or between the crosslinked ethylene-based polymer resin film and the heat-sealing layer. The composite film for hydrogen peroxide sterilization aseptic packaging according to any one of claims 1 to 4. 6. The crosslinked ethylene polymer resin film has a low density of 0.900 to 0.955 g / cm ³ ,
Medium, high density polyethylene or density 0.900 to 0.94
A hydrogen peroxide sterilized aseptic package according to any one of claims 1 to 5, which comprises 5 g / cm ³ of linear low-density polyethylene, a mixture thereof, or a co-extruded product thereof. Film for film.