JPS6037796B2 - Transparent laminated film container and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laminated film container that has excellent dimensional stability, transparency, various gas barrier properties, and interlayer adhesion properties, and a method for producing the same.

Taking advantage of the properties of nylons, which have excellent mechanical strength and gas barrier properties, and the properties of polyolefins, which have excellent moisture resistance and heat-sealing properties, a film made by layering a polyolefin layer and a nylon layer can be used as a transparent laminated film container. It has been known for a long time that polyolefin and nylon have poor mutual adhesion, so when producing a laminated film, it is necessary to use some kind of bonding method that can withstand harsh treatments such as tort sterilization.

The most common method for bonding an olefin resin layer and a nylon layer is the so-called dry lamination method, in which a preformed olefin resin film and a nylon film are bonded using a thermosetting adhesive such as a polyurethane adhesive.
When a laminated film formed by dry lamination is used as a sealed film container for retort sterilization, some problems arise in terms of flavor retention of the food contents. In other words, polyurethane resin is a complex thermosetting resin composition containing uncondensed monomers and relatively low molecular weight binders, and in the packaging described above, the thermosetting adhesive layer is made of high barrier nylon. Because it is always located inside the layer, the aforementioned uncondensed substances and low molecular weight vertical polymers tend to migrate into or interact with the food contents during harsh treatments such as retort sterilization. be.

Further, the above-mentioned thermosetting adhesive is generally provided in a diluted form with an organic solvent such as toluene, ethyl acetate, or methyl ethyl ketone. When laminating nylon and crystalline olefin resin films using such a thermosetting adhesive, a step is taken in which the adhesive is applied to the nylon, the solvent is dried in a hot air oven, and then the adhesive is laminated by pressure bonding.
However, it is difficult to completely remove the organic solvent by oven drying, and this residual organic solvent may migrate into the food contents during retort sterilization treatment and may significantly impair the flavor of the food contents. Due to these reasons, packaging made of a laminated film in which a crystalline olefin resin layer and nylon, etc. are bonded together using a thermosetting adhesive has an excellent preservability, but is not effective in retaining the flavor of the food contents. It was still not completely satisfactory. In order to improve these drawbacks, numerous attempts have been made to directly thermally bond the olefin resin layer and the nylon layer without using a thermosetting adhesive or the like.

These attempts have involved chemically modifying one or both of olefin resins and nylon resins, which do not have mutual thermal adhesive properties, or blending them with ionomers and modified olefin resins, and coextruding both to form laminate molded products. It consists of This method of producing a laminated film by coextrusion has the advantages of easy operation and relatively good laminar twill adhesion between the olefin resin layer and the nylon layer. is still not fully satisfactory in terms of mechanical strength, dimensional stability, transparency, gas barrier properties, etc. In other words, it is known that the various properties mentioned above, such as mechanical strength, dimensional stability, transparency, gas barrier properties, etc., are significantly improved by biaxial molecular orientation of nylon. In the extrusion method, it is extremely difficult to impart bidirectional molecular orientation to the nylon layer, and the resulting film containers are inevitably inferior in these properties.

As a method for producing a laminated film comprising an olefin resin layer and a nylon layer, no method has yet been proposed in which a preformed biaxially stretched nylon film and an olefin resin film are thermally bonded via a thermoplastic resin adhesive. This seems very strange, but the reason for this is thought to be due to the fact that nylon does not exhibit sufficient adhesion to most thermoplastic resin adhesives such as modified olefin resins and ionomers in an unmolten state. The present inventors coextrude a nylon resin and a modified olefin resin, and then apply a special adhesive between the nylon resin layer and the modified olefin resin layer when subjecting this coextruded film to a double stretching operation or a rolling operation. This makes it possible to form excellent interlayer bonding without using layers, and to impart effective in-plane molecular orientation to both resin layers, and this oriented modified olefin resin layer is similar to the crystalline olefin resin of the same type. It has been shown that this laminated film exhibits excellent thermal adhesion to other materials, and that when this laminated film is used in the manufacture of containers, film containers with excellent dimensional stability, transparency, various gas barrier properties, and interlayer adhesion can be obtained. I found it.

According to the present invention, the laminated film material constituting the container has an outer layer made of nylon resin, an inner layer made of crystalline olefin resin, and a carbonyl group content of 1 to 60 melon heq/100 evening weight. The nylon resin layer and the modified olefin resin layer both have in-plane molecular orientation, and the nylon resin layer and the modified olefin resin layer have an in-plane molecular orientation. There is provided a transparent laminated film container characterized in that the resin layer is bonded with a peel strength of 200 mm/1.5 skin or more without using a special adhesive layer.

According to the present invention, a laminated film made of a nylon resin and a modified olefin resin is further formed by coextruding a nylon resin and a modified olefin resin having a carbonyl group content within the range of 1 to 60 heq/100 polymer. This laminated film is biaxially stretched or rolled to form a laminated film in which both resins have in-plane molecular orientation, and then a crystalline olefin resin layer having the same type of constituent olefin units as the modified olefin resin is formed. , there is provided a method for manufacturing a transparent laminated film container, characterized in that the laminated film is thermally bonded to the modified olefin resin layer side of the laminated film, and the formed laminated film is molded into the shape of a container.

The invention will be explained in detail below. In FIG. 1 showing the cross-sectional structure of the laminated film used in the present invention, this laminated film 1 consists of a nylon resin layer 2 with in-plane molecular orientation, a crystalline olefin resin layer 3, and an intermediate layer of modified olefin resin interposed between the two. It consists of 4 layers.

This modified olefin resin layer 4 also has in-plane molecular orientation similar to the nylon resin layer 2, and the modified olefin resin layer and the nylon resin layer are connected to each other without going through a special adhesive layer.
It is a remarkable feature of the present invention that the crystalline olefin resin layer is thermally bonded to the modified olefin resin layer, and the crystalline olefin resin layer is thermally bonded to the modified olefin resin layer. It is a characteristic. First, when the modified olefin resin layer 4 is interposed alone in a molten state between the biaxially stretched nylon film 2 and the crystalline olefin resin layer 3, as shown in Comparative Example 1 described later, 40 evenings/1. There is only an extremely weak interlayer adhesion of about 5 layers, and 500 layers/
In order to obtain a satisfactory interlayer adhesion strength of 15 degrees or higher, the nylon film 2 must be heated to a temperature of at least 20,000 degrees Celsius or higher.

Such heating causes the nylon film 2 to shrink significantly, and furthermore, the painstakingly imparted molecular orientation is relaxed. On the other hand, when nylon resin and modified olefin resin are simultaneously melted and extruded in parallel positions,
When this coextruded film is subjected to a biaxial stretching operation or a rolling operation, the desired in-plane molecular orientation in terms of dimensional stability, transparency, various gas barrier properties, and mechanical strength is imparted to both resin layers, especially the nylon resin layer. This makes it possible to provide this without substantially reducing the interlayer adhesion between both resin layers.

Generally, when an extruded film is subjected to a biaxial stretching operation, there is a tendency that the adhesion between both resin layers often decreases as effective molecular orientation is imparted to both resin layers. Furthermore, when thermally adhering olefin resins to each other, there is a tendency for thermal adhesion to gradually decrease as molecular orientation is imparted to the olefin resin layer. On the other hand, in the coextruded film of nylon resin/modified olefin resin used in the present invention, it is possible to impart in-plane molecular orientation with almost no loss of adhesive strength between the two resin layers, and moreover, It was completely unexpectedly discovered that the modified olefin resin layer also exhibits excellent thermal adhesion to the crystalline olefin resin layer applied later. Furthermore, in the present invention, the modified olefin resin layer is also given an effective molecular saddle orientation, so the final laminated film container formed has even better transparency, moisture resistance, dimensional stability, etc. It has the added advantage of being Examples of the polyamide constituting the outer layer 2 include various homobolyamides, copolyamides, and blends thereof.

Such polyamides include, for example, the following amide repeating units: -CO-R-NH-
...[1) or -CO-RI-CONH-R2-NH- ...{2} In the formula, each of R, RI and R2 represents a linear alkylene group or a xylyreso group,
Mention may be made of homopolyamides, copolyamides or blends thereof having repeating amide units of .

From the viewpoint of gas barrier properties against oxygen, carbon dioxide, etc., homopolyamides, copolyamides, or these polyamides in which the number of amide groups per 100 carbon atoms is in the range of 3 to 3, particularly 4 to 2, are preferred. It is preferable to use a blend of. Examples of suitable homopolyamides are polycapramide (nylon 6) poly-aminoheptanoic acid (nylon 7) poly-
Aminononanoic acid (nylon 9) polyundecasoamide (
Nylon 11) Polylaurinlactam (Nylon 12) Polyethylenediamineadipamide (Nylon 2,6) Polytetramethyleneadipamide (Nylon 4,6) Polyhexamethyleneadipamide (Nylon 6,6) Polyhexamethylene Cebamide (nylon 6,10) Polyhexamethylene dodecamide (nylon 6,12) Polyoctamethylene adipamide (nylon 8,6) Polydecamethylene adipamide (nylon 10,6) Polydodecamethylene sebaca (Nylon 10,8) Polymethaxylylene adipamide Polymethaxylylene beramid Polymethaxylylene sebamido Polymethaxylylene decanedionamide and the like.

Examples of suitable copolyamides include caprolactam/laurinlactam copolymer, caprolactam/hexamethylene diammonium adipate copolymer, lauryl lactam/hexamethylene diammonium adipate copolymer, hexamethylene diammonium Adibate/hexamethylene diammonium sebacate copolymer, ethylene diammonium adipate/hexamethylene diammonium adipate copolymer, caprolactam/hexamethylene diammonium adipate/hexamethylene diammonium sebacate Copolymer, polymethaxylylene/paraxylylene adipamide copolymer, polymethaxylylene/paraxylylene pimeramide copolymer, polymethaxylylene/paraxylylene veramide copolymer, polymethaxylylene nopara Examples include xylylene sebaamide copolymer, polymethaxylylene/paraxylylene decasodionamide copolymer, and metaxylylene/polyxylylene adipamide/caprolactam copolymer.

These homopolyamides and copolyamides can also be used in the form of so-called blends, for example blends of polycaprolactam and polyhexamethylene adipamide, blends of polycaprolactam and caprolactam/hexamethylene diammonium adipamide copolymer. , a blend of polymethaxylyreso/paraxylylene adipamide copolymer and polycaprolactam, etc., can all be used for the purpose of the present invention.

The molecular weight of these polyamides can be used without any particular restriction as long as it is within the range that generally allows film forming.
Dissolve 1 gram of polymer in 100 cc of 98% sulfuric acid,
The relative viscosity (rel) when measured at 20qo is 1.
A range of 8 to 8.5 is generally desirable.

Examples of crystalline olefin resins include known olefin resins that can be heat-sealed and suitably withstand sterilization by torturing, such as low-, medium-, or high-density polyethylene, isotactic polypropylene, and polybutene-1,4. Polyolefins such as -methylbentene-1, ethylene-propylene copolymer, or blends thereof are used.

In order to improve the impact resistance and, in some cases, the blocking property of the polyolefin, a small amount, for example 1 to 3% by weight, of an elastomer such as polyisobutylene, butyl rubber, styrene butadiene rubber, ethylene propylene rubber, etc. is blended with the crystalline olefin resin. can do. The crystalline olefin resin may have a molecular weight sufficient to form a film, and generally has a melt index (MI) of 0.
2 to 50 evenings/10 minutes, particularly 2 to 25 evenings/10 minutes, is preferably used.

The modified olefin resin has a carbonyl group content of 1
A modified olefin resin is used which is a 60 to 60 heq/100 heq polymer, particularly a 10 to 30 heq/100 heq polymer, and whose constituent olefin units are substantially the same type as the crystalline olefin resin. Preferably, as the modified olefin resin, a known carbonyl group-containing ethylenically unsaturated monomer is added to the main chain or side of the olefin resin by graft copolymerization, block copolymerization, random copolymerization, or terminal treatment. Among those introduced into the chain, those that satisfy the above conditions are used.

As the carbonyl group-containing ethylenically unsaturated monomer, a carboxylic acid, a carboxylic acid salt, a carboxylic acid anhydride, a carboxylic acid ester, a carboxamide or imide, an aldehyde, a ketone, etc. may be used alone. , or a combination of ethylenic unsaturated monomers having a cyano (one C=N) group: a hydroxy group; an ether group; an oxirane ring, etc. can be used, and the appropriate An example is as follows.

A Ethylenically unsaturated carboxylic acid: acrylic acid, methacrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, citraconic acid, 5-norbornene-2,3-dicarboxylic acid.

B Ethylenically unsaturated hydroruboxic acid anhydride: maleic anhydride, citraconic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, tetrahydrophthalic anhydride.

C Ethylenically unsaturated ester: ethyl acrylate, methyl methacrylate, acrylic acid 2
-Ethylhexyl, mono- or ethyl maleate, pinyl acetate, vinyl propionate, -propyl hydroxymethacrylate, ethyl 8-hydroxyacrylate, glycidyl acrylate, glycidyl methacrylate, 6
-N-ethylaminoethyl acrylate.

D Ethylenically unsaturated amide or imide: - Acrylamide, methacrylamide, maleimide.

E. Ethylenically unsaturated aldehydes or ketones: acrolein, methacrolein, vinyl methyl ketone, vinyl butyl ketone.

In the present invention, among the above-mentioned monomers, ethylenically unsaturated carboxylic acids and ethylenically unsaturated anhydrous carboxylic acids are particularly preferred, and these monomers may be used alone or in combination with other monomers. Used in combination with to modify olefin resins.

These carbonyl group-containing monomers are bonded to the main chain or side chain of the olefin resin so that the concentration of polar groups is within the above-mentioned range, and more preferably, the crystallinity of the modified olefin resin is at least 15%. Ru.

Examples of the olefin include one or a combination of two or more of ethylene, propylene, budene-1, bentene-1, 4-methylbesothene-1, etc., which satisfy the above-mentioned conditions.

In order to modify an olefin resin so as to satisfy the above-mentioned conditions, for example, in the case of graft treatment, an olefin resin with a crystallinity higher than 15% is selected as the raw material olefin resin, and an olefin resin with a crystallinity higher than 15% is selected. It is necessary to carry out the grafting treatment under conditions such that the degree of crystallinity does not fall below 15%.

For this purpose, high-density polyethylene, isotactic polypropylene, or highly crystalline ethylene-propylene copolymers are preferably used as the backbone polymer, and furthermore, the degree of crystallinity is substantially reduced. Under such mild grafting conditions, medium density polyethylene or low density polyethylene with a crystallinity higher than 15% may also be used. The above-mentioned grafting process can be carried out under conditions known per se, except for the above-mentioned limitations.

For example, a modified olefin resin can be easily produced by bringing a backbone polymer consisting of an olefin resin into contact with a carbonyl group-containing ethylenically unsaturated monomer in the presence of a radical initiator or radical initiation means. The backbone polymer and the monomer can be contacted in a homogeneous solution system, a solid-liquid or solid-liquid heterogeneous system, or a molten homogeneous system. Examples of initiators include organic peroxides such as dicumyl peroxide, t-butylhydro/guoxide, dibenzoyl/guoxide, and dilauroyl peroxide, and azonitrile such as azobisisobutyronitrile and azobisisopropionitrile. etc. are used in catalytic amounts known per se. Radical initiation means include ionizing radiation such as x-rays, y-rays, and electron beams; ultraviolet rays or a combination of ultraviolet rays and a sensitizer; mechanical radical initiation means such as mastication and ultrasonic irradiation; etc. is used. For example, in a homogeneous solution reaction, an olefin resin, a polymer, and an initiator are dissolved in an aromatic solvent such as toluene, xylene, or tetralin to perform grafting, and the resulting modified olefin resin is recovered as a precipitate.

In addition, in a heterogeneous reaction, grafting is carried out by bringing the olefin resin powder into contact with the monomer or a diluted solution of the monomer under irradiation with ionizing radiation. Furthermore, in a homogeneous melt system reaction, a blend of an olefin resin, a monomer, or an initiator is melt-kneaded in an extruder or kneader, etc.
Use modified olefin resin. In any of these cases, the resulting modified olefin resin can be subjected to purification treatments such as vertical washing and extraction in order to remove unpolymerized monomers, homopolymers, initiator residues, and the like. Furthermore, the particle size of the produced modified olefin resin can be adjusted by subjecting it to the recrystallization operation in the aromatic solvent described above and changing the crystallization conditions at that time. In this way, the modified olefin resin used in the present invention can be easily obtained.

Another example of the modified olefin resin having the above-mentioned carbonyl group content concentration is polyethylene oxide.

The oxidized polyethylene used in the present invention is a so-called oxidized base polyethylene obtained by oxidizing polyethylene or a copolymer mainly composed of ethylene in a melt or solution state, if desired, that satisfies the above-mentioned requirements. used.

In the present invention, the above-mentioned modified olefin resins can be used alone or in the form of a blend of two or more types. Moreover, this modified olefin resin can also be used in the form of a blend with a crystalline olefin resin.
In any of these cases, the important point is that the final resin composition should have a carbonyl group content and a main composition of olefinic monomers within the range specified in the present invention. The molecular weight range of the modified olefin resin is the same as that of the crystalline olefin resin. Simultaneous melt extrusion of nylon resin and modified olefin resin can be achieved by using an extruder for nylon and an extruder for modified olefin resin, and extruding the molten resin flows from both extruders through a multilayer multi-tar. It can be done easily.

As for the multilayer die, a method of overlapping within the die is preferable from the viewpoint of adhesiveness, but a method of overlapping outside the die may of course be adopted. The conditions for simultaneous melt extrusion of the nylon resin and modified olefin resin are known per se and will not be described in detail here. Biaxial stretching of the extruded film is preferably carried out by simultaneous biaxial stretching, but if desired, biaxial molecular orientation may be imparted by sequential biaxial stretching in the longitudinal and transverse directions, or conversely, sequential biaxial stretching in the transverse and longitudinal directions. You can also do it.

Instead of biaxially stretching the coextruded film, the coextruded film can be subjected to a single-stage or multi-stage rolling operation to impart in-plane molecular orientation. In the present invention, the in-plane orientation coefficient of the nylon-modified olefin resin laminate, that is, the sum of the orientation coefficient x in the machine direction (machine direction) of the film and the orientation coefficient y in the transverse direction is generally 0.68 or more, particularly 0. .70 or more, most preferably 0.70 or more. It is important that the orientation is within the range above the hammer.

In this specification, the orientation coefficient refers to the degree of orientation of a film in a specific direction determined by birefringence measurement; When the orientation coefficient in the thickness direction is expressed as z, it is a value determined to be x10y+z:1.

Details of the method for calculating the orientation coefficient are as follows.

It is well known that polymers generally have different refractive indexes in the direction of the longest axis and the direction of the shortest axis of the molecule. Therefore, when a polymer film or sheet is stretched, the molecular chains are oriented in the direction of stretching, and the curvature is different in the direction of orientation and in the direction perpendicular to it, and the difference in curvature is defined as birefringence, △. has been done. Here, in the orthogonal three-dimensional coordinates x, y, and z, the x direction is the longitudinal direction of the film, the y direction is also the horizontal direction, and the z direction is also the thickness direction, and the refractive index in each direction is nx, ny , nz, the following formula ni=(
n,,-n”)i tenn↓(=x,y,z)
'6) In the formula, n is the refractive index in the direction perpendicular to the axial direction when the sample is completely aligned, and n↓ is the refractive index in the direction perpendicular to the axial direction when the sample is completely aligned. , i (i=X, y, Z) is R-S. STEIN et al.
J. Applied Physics, 37, 3990 (
1966)) are the orientation coefficients in each direction.

holds true.

nl,,n''- has a unique value depending on the thermoplastic resin.

Therefore, birefringence, △x=nz-ny'△y=nz-n
If any two values of x'Δz=nx-ny are measured, R. S. STEIN report (J.Polyme
rSci. , 24, 388 (1957)), the orientation coefficients x, y, z are determined.

It is a fact remarkable to those skilled in the art that in-plane orientation improves the mechanical strength, transparency, dimensional stability, etc. of the film, and the fact that gas barrier properties are improved is that the oxygen concentration of unstretched 6/66 polymerized nylon Gas permeability is 0.8xlo-11
cc/reduction/en/sec/same-day g (37°C, 0%RH), while that of Futamari-stretched 6/66 copolymer nylon is 0.38 x 10-11cc/skin/c cedar/sec・Toga H
g (3700, 0% RH).

Similarly, the in-plane orientation of the modified olefin resin also results in a significant improvement in moisture resistance. The biaxial stretching or rolling conditions of the coextruded film may be such as to obtain the above-mentioned in-plane orientation, and in the case of two-scale stretching, the longitudinal and transverse stretching ratios are 1.5 to 6. The sound, especially 2.0 to 5.
Stretching is performed under conditions that result in an M sound.

The stretching temperature is 40q○ or higher and the melting point of the modified polyolefin (
below), preferably above the glass transition point of nylon (
It is desirable that the temperature of T powder be within the range of 10)°C or below. In the case of rolling, it is 2.0 to 6. It is desirable to use a rolling magnification of
It can be heated to about 0.00. Thermal adhesion of the in-plane oriented laminated film thus formed to the crystalline olefin resin can be performed by a method known per se, such as an extrusion coating method or a sandwich lamination method.

In the extrusion coating method, a crystalline olefin resin of the same kind as the constituent olefin units of the modified olefin resin is directly melt-extruded onto the modified olefin resin layer side of the laminated film to simultaneously perform coating and thermal bonding. In addition, in the sandwich lamination method, the same type of olefin resin is melt-extruded between the modified olefin resin layer side of the laminated film and the pre-formed crystalline olefin resin film, and the laminated body is adhered with a roll or the like. be exposed. The thickness of the nylon layer is 10 to 50 mm in terms of required physical properties, and the thickness of crystalline olefin resin is 20 to 10 mm in terms of heat sealability.
It is desirable that the modified olefin resin layer has a particle diameter of 5 to 30 particles.

The laminated film produced in this way is made by overlapping the two pieces with the crystalline olefin resin layer on the inside as shown in Figure 2, and heat-sealing the three peripheral parts to make it movable. It can be made into a bag-like container.

Heat sealing can be easily performed using a heating bar, heating knife, heating wire, impulse seal, ultrasonic seal, convection heat seal, etc. Furthermore, a rigid or semi-rigid container equipped with a heat-sealing flange can be obtained by drawing or press-molding the thin layer sheet so that the crystalline olefin resin layer is on the inside. These containers are filled with perishable foods, especially liquid and sex foods, and if necessary, gases such as air that are harmful to storage are removed by vacuum degassing, hot filling, steaming degassing, steam degassing, etc. After removing it by means such as a jetting method or a degassing method by deforming the container, the filling port is sealed by the heat sealing method described above. Next, this package was filled into a retort device and heated for 10 minutes.
It can be heat sterilized at a temperature of 0,000 or higher. The film container according to the present invention does not cause any change in the flavor of the contents even during heat sterilization, and maintains excellent dimensional stability, transparency, and mechanical strength. It has the remarkable advantage of not causing delamination even when it is added.

The present invention will be explained below by way of examples.

Example 1 Relative viscosity is 2.5, melting point is 2160, density is 1.14/
A first extruder having a screw with a diameter of 9 mm was used to prepare isotactic polypropylene with an average carbonyl group concentration of 50 heq/100 mm and a melting point of 161 mm. °C,
25% by weight of modified polypropylene with a melt index (MI) of 7.0 m/1 h and a density of 0.90 m/h, a melting point of 15400, an MI of 9.0 m/1 skin, and an ethylene content of 5 A blend of 75% by weight of mol% ethylene-propylene floc copolymer was heated to 23,000 mol % using an extruder with a 65 mm diameter screw.
Co-extrusion was carried out from a T-shaped two-layer double die with a medium diameter of 65 mm to obtain a laminated sheet having a composition of 6 layers of 240 French nylon/6 layers of 80 French modified polypropylene blend.

Next, this laminated sheet was heated 4.0 times in the longitudinal direction at 1000C,
4 horizontally. The film was simultaneously biaxially stretched at 20,000 yen and fixed in length using 20,000 silica sand to obtain a biaxially stretched two-layer film having an in-plane orientation coefficient (x+y) of 085. Between this biaxially stretched two-layer film and a blown film with a thickness of 60 mm made of an ethylene-propylene flock copolymer with an ethylene content of 4 mol %,
A 95% by weight ethylene-propylene block copolymer with a melting point of 154°C, an MI of 20.0 m/1 h, and an ethylene content of 5 mol%, a melting point of 10,900, and a density of 0.
A blend of 5% by weight of low-density polyethylene with an MI of 12.0 min/min was heated to 250° C. using an extruder with a diameter of 65 mm screw.
Extrusion is carried out from a T-die of 65 enemies kept at o,
By pressing a metal roll with a diameter of 40 mm and a silicone roll with a diameter of 20 mm held at a temperature of 100 Qo, and then cooling with a chill roll with a diameter of 30 mm, the configuration is Stretched nylon 6 layers/5
A laminated film consisting of a French biaxially oriented modified polypropylene blend layer/15 polypropylene blend layers/60 methylene-propylene/7 lock copolymer film layers was obtained.

Peeling between the biaxially oriented nylon 6 layers and the biaxially oriented modified polypropylene friend layer of this laminated film is difficult, and the peel strength between the biaxially oriented modified polypropylene blend layer and the polypropylene blend layer is 800. Evening/1
．． 5 It was a fox.

Two rectangular pieces with the size of 13 mosquitoes x 170 skins were cut out from the laminated film thus obtained, and placed facing each other so that the propylene copolymer layer was the inner layer. , 3kg/of, 1. The bag was obtained by thermocompression bonding under sandy conditions. This was filled with 120-year-old hamburger steak, and the filling port was heat sealed under the same conditions as above.
This was subjected to retort sterilization treatment at 135:00 for 10 minutes under a pressure of 2.1 kg/c fin. At this time, there was no damage to the bag due to peeling between layers or peeling of the seal portion. In addition, the sterilized hamburger steaks were delicious, and the flavor of the hamburger steaks in particular was good, almost the same as before sterilization. Separately, a bag filled with 180 cc of distilled water made of the laminated film, and a structure using 70% of the ethylene-propylene flock copolymer film and urethane adhesive were made of 15mm biaxially oriented nylon 6.
A bag filled with 180 cc of distilled water consisting of a laminated film of film layer/70 ribropylene copolymer layer was prepared.

As a control, a glass ampoule sealed with distilled water was prepared and subjected to the same retort treatment as described above together with the two types of bags. When the water inside was taken out and a 7-flavor test was conducted by a panel of 25 people, the results shown in Table 1 were obtained, and the product of the present invention was superior. Table 1 Examples 2 to 4 Laminated films having the configurations shown in Table 2 were obtained in the same manner as in Example 1 using the materials shown in Table 2, respectively.

Peeling between the biaxially oriented nylon layer and the biaxially oriented modified polypropylene layer of these laminated films is difficult, and the peel strength between the biaxially oriented modified polypropylene layer and the polypropylene blend layer is as shown in Table 2. It is. next,
From these laminated films, bags with a size of 13 proboscis x 17 arteries were made using the same machine as in Example 1, and 12
After filling and sealing hamburger steak of 100g.

These were retort sterilized at 135o0 for 10 minutes, but there was no damage to the bag due to peeling between layers or peeling of the seal portion. In addition, the pasteurized hamburger steak was delicious, and the flavor was particularly good. Table 2 Comparative Example 1 In Example 1, instead of the biaxially stretched nylon/modified polyolefin, a biaxially stretched nylon 6 film with a thickness of 20 mm and an in-plane orientation coefficient (x+y) of 0.85 was used as an extruded resin. Isotactic, polypropylene grafted with maleic anhydride, with an average carbonyl group concentration of 50
25% by weight of modified polypropylene with a melting point of 1610C and an MI of 7.0mm/1mm
and density is 0.90 yen/carp, melting point is 154℃, MI is 25
．． 70% by weight of an ethylene-propylene block copolymer with an ethylene content of 5 mol% and a density of 0.919/yen, MI 12.0/IQhin,
A blend of 5% by weight of low-density polyethylene with a melting point of 10,900 is used, and the composition is 6 layers/2 of 20 mm and 2 mm stretched polyethylene.
A laminated film of 5 French-modified polypropylene blend layer/60 ethylene-propylene block copolymer film layer was obtained.

The peel strength between the 2-stretched nylon 6 layers and the modified polypropylene blend layer of this laminated film is 40/1
．． It showed a very low value of 5c and was unsuitable as a packaging material for retorts. Comparative Example 2 In Example 1, when maleic anhydride-modified polypropylene with an average carbonyl group concentration of 0.8 meq/100 weight was used as the modified polypropylene, the nylon layer and the modified polypropylene layer were not separated by retort sterilization treatment. It was unsuitable as a packaging material for retorts.

Comparative Example 3 In Example 1, maleic anhydride-modified polypropylene with a very high degree of modification with an average carbonyl group concentration of 65 heq/100 kg was used as the modified polypropylene blend. Foaming was observed due to resin decomposition.

Furthermore, the flavor of the hamburger steak that was filled into a bag made of the obtained laminated film and then retort sterilized was poorer than that of Example 1. Example 5 The biaxially stretched nylon 6/modified pripropylene two-layer film used in Example 1 was used as the base layer, and the modified pripropylene layer side had a density of 0.
．． 90 pm/earth, melting point 154 qo, MI 12.0 pm/
A blend of ethylene-propylene with an ethylene content of 5 mol%, block copolymer 9 (wt%) and ethylene-propylene copolymer rubber 1 (wt%) with an ethylene content of 60 mol% and an average molecular weight of 10. Using an extruder with a diameter 65 side screw, extrusion was carried out through a medium 650 willow T-die maintained at a temperature of 27,000 °C to a temperature of 40 qo.
A metal roll with a diameter of 40 cm and a diameter of 2
0 enemy mosquito? By pressing with a silicone roll of Obtained.

Peeling between the 6 layers of biaxially oriented nylon and the biaxially oriented modified polypropylene blend layer of this laminated film is difficult, and the peel strength between the biaxially oriented modified bripropylene blend layer and the polypropylene blend layer is 740/1
．． There were five enemies.

Next, a bag measuring 80 m x 12 m was made from this laminated film, and the bag was filled with 70 ml of meat balls and heat-sealed. This was retort sterilized at 135 oo for IQ minutes, but there was no damage to the bag due to peeling between layers or peeling of the seal portion. The pasteurized meatballs were also delicious, with particularly good flavor. Example 6 Maleic anhydride was grafted onto Tanosu's nylon 6 and low density polyethylene with a relative viscosity of 2.5, a melting point of 215o0, and a density of 1.14.The average carbonyl group concentration was 24o0.
q/100 polymer, melting point 116q0, MI 4.0
40% by weight of modified polyethylene of 1 liter of ethylene-methacrylic acid copolymer with carbonyl group concentration of 21 heq/100 qo polymer, melting point of 99 qo, MI of 5.0 qo /1 enemy hjn ionomer
20% by weight, MI 2.0/1 h melting point 116
A biaxially stretched two-layer film with a planar orientation coefficient of 0.83 consisting of a blend of 4% by weight of low-density polyethylene is used as the base material, and a modified polyethylene blend layer side with a density of 0.922% is used as the base material. /lump, melting point 10900, MI 4.
Low-density polyethylene of 0 m/1 h is heated to 310 °C using an extruder with a diameter of 65 mm screw.
The metal was extruded from a willow T-die at 650 °C and had a diameter of 40 °C.

By applying the low-density polyethylene with a silicone roll with a diameter of 20 mm and then extrusion coating the low-density polyethylene under the same conditions using a tandem method, the structure was
A laminated film of 6 layers of axially oriented nylon/10 layers of biaxially oriented modified polyethylene blend/35 layers of low density polyethylene/35 layers of low density polyethylene was obtained. Peeling between the 6 layers of biaxially oriented nylon and the biaxially oriented modified polyethylene blend layer of this laminated film is difficult, and the peel strength between the biaxially oriented modified polyethylene friend layer and the low density polyethylene layer is 62M. /1.5c.

Next, a bag having a size of 80 legs x 18 arteries was prepared from this laminated film, and this bag was filled with 150 pieces of cut mochi and heat-sealed.

This was retort sterilized at 10500 for 20 minutes, but there was no damage to the bag due to peeling between layers or peeling of the seal portion. In addition, the sterilized rice cakes were delicious and had particularly good flavor. Example 7 Density is 0.90 mm/earth, melting point is 157 o0, MI is 12
．． An ethylene-propylene floc copolymer with an ethylene content of 4 mol % was produced at a density of 0.90 m/min using a first extruder for inner and outer layers having a screw with a diameter of 65 mm. Earth, melting point 150o0, MI 12.0
85% by weight of an ethylene-propylene flock copolymer with an ethylene content of 4 mol% and 1% by weight of an ethylene-propylene copolymer rubber with an ethylene content of 60 mol% and an average molecular weight of 100,000. The diameter of the blend is 6
Coextrusion was carried out using a second extruder for the middle layer with a screw in 5 bars through a T-die of 65 pieces in which the temperature was maintained at 250°C, and this ethylene-propylene floc copolymer//ethylene -Propylene floc copolymer blend/ethylene-propylene floc.

The molten three-layer laminate of the carbonaceous copolymer and the double-stretched nylon 6/modified polypropylene two-layer film used in Example 1 were heated to a diameter of 400 mm. A metal roll with a diameter of 20 mm? Composition is 15A2 by crimping with silicone roll.
6 layers of axially oriented nylon / 5 layers of biaxially oriented modified polypropylene blend layer / 10 layers of ethylene-propylene block copolymer layer / 50 layers of ethylene-propylene block copolymer blend layer / 10 layers of ethylene-propylene block A laminated film of copolymer layers was obtained. It is difficult to separate the 6 layers of biaxially oriented nylon from the 6 layers of biaxially oriented nylon and the 2-layer oriented modified polypropylene blend layer. The peel strength between is 730/1
．． It was 5 cm.

Next, a bag with a size of 16 Q x 17 m was produced from this laminated film by heat sealing, and the resulting bag was filled with 150 yen of shumai and heat sealed.

This was retort sterilized at 13500 for 10 minutes, but there was no damage to the bag due to peeling between layers or peeling of the seal portion. In addition, the sterilized shumai was delicious, and the flavor was particularly good. Example 8 A laminated sheet of the same resin composition as used in Example 1 with a thickness of 6 layers of 100 French nylon/50 French modified polypropylene blend layers was prepared at a temperature of 7000°C and with a diameter of 20 mm.
A two-layer rolled film was obtained by rolling 5 times using a pair of rolling rolls with a 0-side roll.

Using this laminated film as a base material, the structure was made in the same manner as in Example 1: 6 layers of 20mm rolled nylon/10mm rolled modified propylene blend layer/20mm pripropylene blend layer/60mm ethylene-propylene block copolymer film. A laminated film of layers was obtained. Peeling between the rolled nylon 6 layer and the rolled modified polypropylene blend layer of this laminated film is difficult, and the peel strength between the rolled polypropylene blend layer and the polypropylene blend layer is 760 mm/1.5 mm. Met.

Next, from this laminated film, 13
Make bags the size of 17 enemies and put 1 in each bag.
After filling and sealing hamburger steak for 20 days. This was retort sterilized at 135 oo for 10 minutes, but there was no damage to the bag due to peeling between layers or peeling of the seal portion. In addition, the pasteurized hamburger steak was delicious, and the flavor was particularly good. Comparative Example 4 The nylon 6 of Example 1 was extruded using a first extruder with a screw 5 mm in diameter, and the modified polypropylene blend of Example 1 was extruded in a second extruder with a screw 5 mm in diameter. Similarly, Example 1 was carried out using an extruder.
The ethylene-propylene floc copolymer used for the blown film was melt-extruded from a three-layer triple circular tie using a third extruder with a screw with a diameter of 65 mm. A laminated film having a structure of 20 nylon 6 layers/10 ethylene modified polypropylene blend layer/70 ethylene ethylene-propylene block copolymer layer was obtained.

When the thus obtained laminated film was compared with the laminated film of Example 1 of the present invention, it was found that the dimensional stability was poor and the printability was insufficient.

Further, the oxygen gas barrier property was also inferior to that of Example 1. Furthermore, when a drop test was conducted on a bag using this laminated film, the bag breakage rate was higher than that of Example 1.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an example of a transparent laminated film according to the present invention, and FIG. 2 is a cross-sectional view of an example of a transparent sealed package of the present invention. 3 is a crystalline olefin resin layer,
4 indicates an in-plane oriented modified olefin resin layer, and 5 indicates a heat-sealed portion. Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1. The laminated film material constituting the container includes an outer layer made of nylon resin, an inner layer made of crystalline olefin resin, and a carbonyl group content of 1 to 600 interposed between both layers.
The nylon resin layer and the modified olefin resin layer both have in-plane molecular orientation, comprising an intermediate layer made of a modified olefin resin having a concentration of meq/100g polymer and whose constituent olefin units are the same type as the crystalline olefin resin. ,
A transparent laminated film container characterized in that both resin layers are bonded with a peel strength of 200 g/1.5 cm or more without using a special adhesive layer. 2. The film container according to claim 1, wherein the nylon resin and modified olefin resin layer have an in-plane orientation coefficient of 0.7 or more as determined by a birefringence method in a laminated state. 3. The film container according to claim 1, wherein the nylon resin layer and the modified olefin resin layer are in-plane oriented by biaxially stretching these coextruded films. 4. The film container according to claim 1, wherein the nylon resin layer and the modified olefin resin layer are in-plane oriented by rolling a coextruded film thereof. 5 Nylon resin and carbonyl group content from 1 to 600
A laminated film consisting of nylon resin and modified olefin resin is formed by coextruding modified olefin resin within the range of meq/100g polymer, and this laminated film is stretched in two axes or rolled so that both resins are flat. A laminated film with inner molecular orientation is formed, and then a crystalline olefin resin layer having the same type of constituent olefin units as the modified olefin resin is thermally bonded to the modified olefin resin layer side of the laminated film, and the resulting laminated film is A method for manufacturing a transparent laminated film container, characterized by forming the container into the shape of the container.