JP2001009997A - Packaging film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a packaging film imparting excellent packaging appearance, enhanced in productivity in a packaging process and having high sealing capacity. SOLUTION: In a packaging film having a multilayered structure wherein at least a surface substrate layer, an intermediate layer and a sealant layer are laminated in this order, the intermediate layer and the sealant layer comprise a resin compsn. of an ethylene/α-olefin copolymer produced by using a metallocene catalyst in a specific range and having a specific melt flow rate and specific density and high-pressure-processed low density polyethylene.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packaging film, and more particularly, to a multilayer packaging film in which a surface base material layer, an intermediate layer and a sealant layer are laminated in this order. In particular, it relates to a liquid-filling packaging film.

[0002]

2. Description of the Related Art JP-A-8-225690 discloses that
(A) a density (d) of 0.880 to 0.935 g / cc;
(B) Melt flow rate (MFR) is 1.0 to 50 g.
/ 10 minutes, (C) The integrated amount (EF40) at an elution temperature of 40 ° C. or less calculated from the temperature rise elution fractionation result satisfies the expression (1). In (EF40) ≦ −104.74 + 0.09
4 × ln (MFR) + 97.6 / (d) (1) 60-90% by weight of ethylene / α-olefin copolymer characterized by the above (A), (B) and (C) and obtained by high pressure radical polymerization An extrusion laminating material comprising 10 to 40% by weight of polyethylene having a density of 0.910 to 0.935 g / cc and a melt flow rate of 1.0 to 20 g / 10 minutes is disclosed.

[0003] Japanese Patent Application Laid-Open No. 9-150490 discloses a multilayer sealant film comprising a base material layer and a seal layer laminated on at least one surface thereof, wherein the base material layer has a density of 0.900-0. The sealing layer has a melting point in the range of 97 to 115 ° C. and a weight average molecular weight / number average molecular weight value of 1.5 to 3; At a crystal melting temperature measured using a differential scanning calorimeter, a linear low melting point having a single crystal melting peak and a temperature range from the start of melting of all the crystals of the film to the end of the melting within 20 ° C. A multilayer sealant film is disclosed, which is made of a high density polyethylene resin and has a thickness of a sealing layer of 30% or more of the thickness of the entire film.

Japanese Patent Application Laid-Open No. 9-169087 discloses a 100% by weight linear low-density ethylene-α-olefin copolymer produced using a Ziegler catalyst or a Phillips catalyst, and a single-site catalyst. An ethylene-based resin composition comprising 30 to 70 parts by weight of an ethylene-α-olefin copolymer produced by the above method and 50 to 100 parts by weight of a high-pressure low-density polyethylene is mixed with a polyamide resin, a polyester resin, a polyvinylidene chloride resin, A laminated film is disclosed which is extrusion-coated on a single-layer or multilayer substrate film of at least one selected from the group consisting of vinyl alcohol copolymer resin and aluminum.

JP-A-10-80986 discloses a laminate comprising at least a first layer I serving as a base material and a second layer serving as a sealant layer, wherein the second layer satisfies specific requirements. Homopolymers or ethylene / α-olefin copolymers are disclosed.

Japanese Patent Application Laid-Open No. 10-86300 discloses a seal layer made of linear low-density polyethylene having a density of 0.860 to 0.925 g / cm 3 and a weight average molecular weight / number average molecular weight of 1 to 3, 0.900 to 0.935 g /
cm3, a base layer made of linear low-density polyethylene, a laminate layer made of linear low-density polyethylene having a density of 0.915 to 0.950 g / cm3, and a biaxially stretched plastic film layer. A characteristic linear low-density polyethylene-based composite film is disclosed.

[0007] JP-A-10-237234 discloses that
(A) a packaging film having a basic structure of a laminate comprising a base material layer / (B) intermediate layer / (C) inner layer, wherein (B) the intermediate layer is
It comprises a composition comprising 50 to 95% by weight of a linear low-density polyethylene and 5 to 50% by weight of a copolymer of a cyclic olefin and an α-olefin, wherein the inner layer (C) has a density of 0.935 g / cm 3 or less. A packaging film comprising a layer of a chain low-density polyethylene.

JP-A-10-259279 discloses a polyethylene-based resin composition of a specific ethylene-α-olefin copolymer and high-density polyethylene, and a film thereof.

Japanese Patent Application Laid-Open No. 11-10809 discloses a film having a multilayer structure in which at least a surface base material layer, an intermediate layer and a sealant layer are laminated in this order, wherein the intermediate layer is a linear low-density polyethylene. The mixing ratio [(A) / (B)] of (A) and high-pressure low-density polyethylene (B) is 70/3.
The linear low-density polyethylene (A) is a copolymer of ethylene and an α-olefin having 4 or more carbon atoms, and has a melt flow rate of 0 to 40/60. 1 to 50 g / 10 min and a density of 0.1 g / m.
890-0.930 g / cm 3, Mw / Mn showing the molecular weight distribution is 1.5-4.0, and the high pressure method low density polyethylene (B) has a melt tension of 2 g or more. A packaging film is disclosed.

JP-A-11-123800 discloses that ethylene and an α-olefin mainly composed of 1-butene are copolymerized in the presence of a catalyst having a plurality of polymerization active sites and have a density of 0.910 to 0.930 g / cm
3 is obtained on at least one surface of the layer made of the linear low-density polyethylene (a) by polymerization using a catalyst having a single polymerization active site, and the value of weight average molecular weight / number average molecular weight is 1.5. ~ 3.0 and a density of 0.885
A layer composed of linear low-density polyethylene (b) having a thickness of 0.920 g / cm @ 3 and a layer thickness ratio of linear low-density polyethylene (a) / linear low-density polyethylene (b). A sealant film is disclosed, wherein the layer consisting of b) = 1/1 to 5/1.

[0011]

A film obtained by laminating a polyethylene resin as a sealant layer on a film base such as nylon is used as an automatic packaging material for filling liquid such as soups and sauces.

[0012] In the packaging for automatic filling of these liquids and the like, there is a need for a film having improved packaging quality, improved packaging appearance, improved productivity in the packaging process, and higher performance sealing performance. Had been.

[0013]

The present invention provides a packaging film having a multilayer structure in which at least a surface substrate layer, an intermediate layer and a sealant layer are laminated in this order, wherein the intermediate layer is produced from a metallocene catalyst. Ethylene-α-olefin comprising a resin composition of 50 to 95% by weight of the ethylene-α-olefin copolymer (A) and 50 to 5% by weight of a high-pressure low-density polyethylene (B) prepared from a metallocene catalyst The copolymer (A) has a melt flow rate of 1 g /
10 minutes to 18 g / 10 minutes, and the density is 0.908 g /
Beyond cm ³ was 0.940 g / cm ^3, the high-pressure low-density polyethylene (B) has a melt flow rate of 0.
5 g / 10 min to 15 g / 10 min and a density of 0.91
Was ^{0g / cm 3 ~0.940g / cm 3} , the sealant layer, of ethylene -α- produced from a metallocene catalyst
Ethylene-α- produced from a metallocene catalyst, comprising a resin composition comprising 57 to 92% by weight of an olefin copolymer (A) and 43 to 8% by weight of a high-pressure low-density polyethylene (B).
The olefin copolymer (A) has a melt flow rate of 6
g / 10 minutes to 23 g / 10 minutes, and the density is 0.887.
a ^{g / cm 3 ~0.908g / cm 3} , the high-pressure low-density polyethylene (B) has a melt flow rate of 0.5
g / 10 minutes to 13 g / 10 minutes, and the density is 0.910.
that is g / cm ³ ~0.927g / cm ³ regarding packaging film characterized.

Further, the present invention relates to a packaging film, wherein the packaging film is an automatic packaging film.

Further, the present invention relates to a packaging film, wherein the packaging film is an automatic packaging film for liquid filling.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The packaging film of the present invention is a packaging film having a multilayer structure in which at least a surface base material layer, an intermediate layer and a sealant layer are laminated in this order, wherein the intermediate layer is a metallocene catalyst. Ethylene-α produced from
-50% by weight as the lower limit of the olefin copolymer (A),
Preferably 55% by weight, more preferably 60% by weight,
Particularly preferably, the upper limit is from 65% by weight to 95% by weight, preferably 90% by weight, more preferably 88% by weight, particularly preferably 85% by weight, and the lower limit of the high pressure method low density polyethylene (B) is 5% by weight, preferably 5% by weight. Is 10% by weight, more preferably 12% by weight, particularly preferably 15% by weight.
From 50% by weight, preferably 45% by weight, more preferably 40% by weight, particularly preferably 3% by weight.
Ethylene-α-olefin copolymer (A) comprising 5% by weight of a resin composition and produced from a metallocene catalyst
Has a melt flow rate of 1 g / 10 minutes as a lower limit,
Preferably 2 g / 10 min, more preferably 3 g / 10 min
Min, particularly preferably from 4 g / 10 min to 18 as the upper limit.
g / 10 min, preferably 16 g / 10 min, more preferably 14 g / 10 min, particularly preferably 12 g / 10 min, and the density exceeds the lower limit of 0.908 g / cm ³ , preferably 0.910 g / Cm ³ , more preferably 0.912 g / cm ³ , particularly preferably 0.915 g
/ Cm ³ 0.940g / cm ³ as the upper limit from, preferably 0.935 g / cm ^3, more preferably 0.93
0 g / cm ³ , particularly preferably 0.925 g / cm ³ , and the high-pressure method low-density polyethylene (B) has a lower limit of the melt flow rate of 0.5 g / 10 min, preferably 1 g / 10 min. It is preferably 1.5 g / 10 min, particularly preferably 2 g / 10 min and 15 g / 1 as the upper limit.
0 min, preferably 13 g / 10 min, more preferably 1 g
The density is 1 g / 10 min, particularly preferably 9 g / 10 min, and the density has a lower limit of 0.910 g / cm ³ , preferably 0.912 g / cm ³ , and more preferably 0.913 g.
/ Cm ³ , particularly preferably from 0.915 g / cm ³ to an upper limit of 0.940 g / cm ³ , preferably 0.935 g / cm ^3.
g / cm ^3, more preferably 0.930 g / cm ^3, particularly preferably 0.925 g / cm ^3, the sealant layer, of ethylene -α- produced from a metallocene catalyst
The lower limit of the olefin copolymer (A) is 57% by weight, preferably 59% by weight, more preferably 61% by weight, particularly preferably 63% by weight to 92% by weight as an upper limit,
Preferably 91% by weight, more preferably 89% by weight,
It is particularly preferably 87% by weight and the lower limit of the high pressure method low density polyethylene (B) is 8% by weight, preferably 9% by weight, more preferably 11% by weight, and particularly preferably 13% by weight.
From the upper limit to 43% by weight, preferably 41% by weight,
More preferably, the ethylene-α-olefin copolymer (A) produced from a metallocene catalyst comprises 39% by weight, particularly preferably 37% by weight of the resin composition, and has a lower limit of 6 g / 10. Min, preferably 6 g / 10 min, more preferably 7 g / 10 min, particularly preferably 8 g / 10 min to 23 g / 10 min as the upper limit.
Min, preferably 21 g / 10 min, more preferably 19
g / 10 minutes, particularly preferably 17 g / 10 minutes, and the density has a lower limit of 0.887 g / cm ³ , preferably 0.889 g / cm ³ , more preferably 0.891 g.
/ Cm ³ , particularly preferably 0.892 g / cm ³ as an upper limit to 0.908 g / cm ³ , preferably 0.906
g / cm ^3, more preferably 0.905 g / cm ^3, particularly preferably 0.904 g / cm ^3, the high-pressure low-density polyethylene (B) is, 0.5 g / 10 melt flow rate as the lower limit value Min, preferably 1 g / 10 min,
More preferably 1.5 g / 10 min, particularly preferably 2 g / 10 min.
g / 10 minutes to 13 g / 10 minutes as an upper limit, preferably 12 g / 10 minutes, more preferably 10 g / 10 minutes,
Particularly preferably, the density is 9 g / 10 min, and the density is 0.910 g / cm ³ as a lower limit, preferably 0.912 g / c.
m ^3, 0.92 and even more preferably 0.913 g / cm ^3, particularly preferably the upper limit of 0.915 g / cm ³
7 g / cm ^3, preferably 0.926 g / cm ^3, more preferably 0.925 g / cm ^3, particularly preferably 0.
A packaging film characterized by having a weight of 923 g / cm ³ .

In particular, in the packaging film of the present invention,
By using the intermediate layer and the sealant layer having the above characteristics, when powders, liquids, gases, and the like are used for automatic filling by an automatic filling device, sealing at the time of roll sealing of the horizontal seal portion can be performed without any problem. In particular, when used for automatic liquid filling, the effect is great.

The intermediate layer and the sealant layer of the packaging film of the present invention have the following advantages: (1) When the intermediate layer and the surface substrate layer are laminated, the adhesion strength between the intermediate layer and the surface substrate layer is reduced. In order to increase the intermediate layer, a resin composition that can be molded at a high temperature is required as the intermediate layer to oxidize the surface of the intermediate layer. (2) A resin composition that can be molded at a low temperature that suppresses oxidation of the surface of the sealant layer in order to improve the sealing properties It is necessary to bond and use the intermediate layer and the sealant layer having the above characteristics.

The packaging film of the present invention is preferably a packaging sealant film.

If the density of the ethylene-α-olefin copolymer (A) produced from the metallocene catalyst in the intermediate layer is larger than the above range, the interlayer adhesion strength with the resin of the sealing layer is reduced, so that the filling bag is broken. Easily, the transparency of the film deteriorates. When the density of the ethylene-α-olefin copolymer (A) produced from the metallocene catalyst in the intermediate layer is smaller than the above range, the low-temperature sealing performance at the time of automatic filling deteriorates. Are likely to remain. These characteristics are particularly susceptible to automatic liquid filling.

When the melt flow rate of the ethylene-α-olefin copolymer (A) produced from the metallocene catalyst in the intermediate layer is larger than the above range, the contents are liable to remain in the horizontal seal portion during automatic filling. In the case where the thickness is small, the load of the extruder at the time of molding processing increases, and molding becomes difficult. These characteristics are particularly susceptible to automatic liquid filling.

When the density of the ethylene-α-olefin copolymer (A) produced from the metallocene catalyst in the sealant layer is larger than the above range, the low-temperature sealing performance at the time of automatic filling is deteriorated. The slipperiness is worsened, the hot tack performance is worsened, and the seal is poor.
These characteristics are particularly susceptible to automatic liquid filling.

When the melt flow rate of the ethylene-α-olefin copolymer (A) produced from the metallocene catalyst in the sealant layer is higher than the above range, the contents remain in the horizontal seal portion during automatic filling, and the meat in the seal portion Thinning occurs, the pressure of the seal roll is lost, resin pools are generated, hot tack performance deteriorates, and sealing failure occurs. On the other hand, if it is small, the load on the extruder during the molding process increases, and molding becomes difficult.
These characteristics are particularly susceptible to automatic liquid filling.

If the density of the high-pressure method low-density polyethylene (B) in the sealant layer is larger than the above range, hot tack performance deteriorates, resulting in poor sealing. If the density is small, heat resistance and slipperiness of the film deteriorate. These characteristics are particularly susceptible to automatic liquid filling.

When the melt flow rate of the high-pressure method low-density polyethylene (B) in the sealant layer is larger than the above range, the contents remain in the horizontal seal portion, the seal portion becomes thin, and the resin loses the pressure of the seal roll and accumulates in the resin. Occurs, and the neck-in in the extrusion lamination molding becomes worse. On the other hand, if it is small, gel is generated on the film, resulting in poor appearance.
These characteristics are particularly susceptible to automatic liquid filling.

When the weight ratio of the ethylene-α-olefin copolymer (A) produced from the metallocene catalyst of the sealant layer to the high-pressure low-density polyethylene (B) is larger than the above range, the hot tack performance deteriorates and the sealing is poor. When the film is small, the heat resistance and the slipperiness of the film are deteriorated, and the neck-in in the extrusion laminating is deteriorated. These characteristics are particularly susceptible to automatic liquid filling.

High pressure method low density polyethylene for intermediate layer (B)
If the density is larger than the above range, the interlayer adhesion strength with the sealing layer resin is reduced, so that the filled bag is easily broken.

High pressure method low density polyethylene for intermediate layer (B)
If the melt flow rate is higher than the above range, the contents will remain in the horizontal seal, the seal will become thin,
The resin in the seal roll loses the pressure of the seal roll, and the neck-in in the extruded laminate molding becomes worse. On the other hand, if it is small, gel is generated on the film, resulting in poor appearance. These characteristics are particularly susceptible to automatic liquid filling.

When the weight ratio between the ethylene-α-olefin copolymer (A) produced from the metallocene catalyst in the intermediate layer and the high-pressure low-density polyethylene (B) is larger than the above range, the film strength decreases and the film breaks. The seal portion is easily broken, the seal portion becomes thin, and the pressure of the seal roll is lost, and a resin pool is generated. On the other hand, if it is small, neck-in in extrusion lamination is worse. These characteristics are particularly susceptible to automatic liquid filling.

The heat resistance of the heat-sealer of the packaging film of the present invention is 200 g / 15 mm or less, and more preferably 180 g / 1.
It is preferably 5 mm or less, particularly preferably 150 g / 15 mm or less.

The hot tack stress at 90 ° C. of the packaging film of the present invention is preferably 1.2 N / inch or more. The hot tack stress at 100 ° C. of the packaging film of the present invention is preferably 1.5 N / inch or more. In particular, the hot tack stress of the packaging film is preferably 1.2 N / inch or more at 90 ° C. and 1.5 N / inch or more at 100 ° C.

The low-temperature sealability of the packaging film of the present invention is less than 160 ° C., more preferably less than 155 ° C., especially 150 ° C.
The following is preferred.

The appearance of the horizontal seal portion of the packaging film of the present invention is higher than 170 ° C., more preferably higher than 175 ° C., and particularly preferably 180 ° C. or higher.

Ethylene-α-olefin copolymer (A)
Is mainly composed of ethylene, propylene and butene
Α-olefins such as linear α-olefins having 2 to 8 carbon atoms such as 1, pentene-1, 4-methylpentene-1, hexene-1, octene-1, and cyclic α-olefins such as cyclopentene and cyclohexene Alternatively, a copolymer produced from a mixture thereof and a metallocene catalyst can be used. Further, ethylene is 50 mol% or more, further 60 mol% or more, particularly 70 mol% or more and having 2 to 2 carbon atoms.
An ethylene-α-olefin copolymer with the olefin of No. 8 can be preferably used. In particular, ethylene and α-
The repeating unit derived from the α-olefin in the copolymer with the olefin is usually in the range of 12 mol% or less, more preferably in the range of 0.1 to 10 mol%, and particularly preferably in the range of 2 to 10 mol%.
The ethylene-α-olefin copolymer contained in the range is preferred.

Ethylene prepared from metallocene catalyst
As the α-olefin copolymer (A), an ethylene-α-olefin copolymer (A) produced by a gas phase polymerization reaction can be used.

As the metallocene catalyst, a known metallocene catalyst can be used. For example, as the metallocene-based catalyst, a combination of a metallocene compound of a transition metal of Group IV or V of the periodic table, an organic aluminum compound and / or an ionic compound can be used.

The transition metals of Group IV or V of the Periodic Table include:
Titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V) and the like are preferable.

Ethylene-α-olefin copolymer (A)
Can be produced from a known gas phase polymerization reaction using a known metallocene catalyst.

The high-pressure low-density polyethylene (B) can be produced by high-pressure radical polymerization.

As the high-pressure low-density polyethylene (B), not only a homopolymer of ethylene but also a copolymer with another monomer such as an ethylene-vinyl acetate copolymer can be used. When an ethylene-vinyl acetate copolymer is used, the amount of the repeating unit derived from vinyl acetate in the copolymer is usually preferably 20% by weight or less.

Each composition used in the intermediate layer and the sealant layer of the present invention is obtained by mixing each component with various kneaders such as a Banbury mixer, a roll mixer, a kneader, a high-speed mixer and an extruder, preferably a single screw or twin screw extruder. Mix using
A kneaded product can be used. Further, pellets mixed by dry blending and kneaded during film forming can be used.

As the surface substrate layer, a biaxially stretched polyamide film (ONY), a biaxially stretched polyester film,
Polyvinylidene chloride coated biaxially oriented polypropylene (K
OP), biaxially oriented polypropylene (OPP), polyvinylidene chloride-coated biaxially oriented nylon (KONY), oriented polyolefin film, paper, metal foil such as aluminum foil, etc. It can also be used as a film / sheet laminated with these substrates. This surface base material layer can be used by laminating a plurality of kinds as long as the hand tearability is not impaired.

The method for laminating the intermediate layer and the sealant layer is preferably extrusion lamination. The method is to apply twice with single lamination, tandem extrusion lamination,
Methods such as sandwich lamination and co-extrusion lamination are possible.

The thickness of the intermediate layer is preferably in the range of 10 μm to 40 μm.

The thickness of the sealant layer is 10 μm to 40 μm
Is preferable.

In the packaging film of the present invention, since the resin used for the intermediate layer and the sealant layer has a small neck-in and a small torque at the time of kneading, the intermediate layer is extruded into a film on one surface of the surface base material layer. Immediately after extrusion of the intermediate layer, the sealant layer can be manufactured by extruding a sealant layer on one surface of the intermediate layer in the form of a film.

The packaging film of the present invention comprises a surface substrate layer,
Intermediate layer, any or all of the sealant layer, if necessary, lubricants, anti-blocking agents, antioxidants, UV absorbers, heat stabilizers, flame retardants, inorganic and organic fillers, antistatic agents, A coloring agent or the like can be added.

[0048]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. The method for measuring the properties of the components constituting each layer, the method for measuring physical properties, and the resin material used in the present invention are as follows.

The properties of the three-layer film formed by laminating the resin constituting the respective layers used in the present invention, the surface base material layer, the intermediate layer and the sealant layer were determined by the following measuring methods. (1) Density: 190 according to JIS K7112
C., the strand obtained at the time of melt flow rate measurement under a load of 2.16 Kg was heat-treated at 100 ° C. for 1 hour,
The sample cooled slowly to room temperature over 1 hour was measured using a density gradient tube. (2) Melt flow rate (MFR): JIS K72
In accordance with No. 10, using a melt indexer, 190
It was determined by measuring the weight of the resin extruded into a strand in 10 minutes under a load of 2.16 kg at 10 ° C.

(3) Neck-in: 65 mmφ extruder, L
/ D = 24, extruder drive motor 30KW, die opening length 450mm, die slip clearance 0.7mmt
Using an extrusion laminator (made by Minamisenju Seisakusho Co., Ltd.)
Film forming speed 100mm, screw rotation speed 75r
pm (discharge rate 55 kg / h), resin temperature of the intermediate layer is 290 ° C., resin temperature of the sealant layer is 270 ° C., and air gap is 120 mm. Was done. From the width of the film extruded onto the PET film, the neck-in was calculated according to the following equation.

(Equation 1)

(4) Torque: (3) The current value (A) applied to the extruder motor at the time of film formation at the neck-in was read.

(5) Gel amount: Uniplus CS30-2
4 type extruder, screen pack (# 60/80/120
/ 120/80/60), die 300mm width, lip CR 0.8mm, temperature setting 200 ° C, mirror surface cooling roll (cooling water temperature 40 ° C setting), take-up speed 8m / min, forming a 50μm thick film Then, gels of 0.1 mm or more were counted by a defect inspection apparatus manufactured by Hutec. ○: When 100 or less exist in 1 m ² . ×: When 100 or more exist in 1 m ² .

(6) Heat Sealer Heat Resistance: Two Fills
Heat sealer
, Seal bar width 25mm, seal pressure 0.65Kg
/ Cm ^Two, Sealing time 1 minute, hot platen temperature 70 ° C
Thermal adhesion (sealing) was performed. Including the sealing part of the adhesive film
The film into a strip with a width of 15 mm perpendicular to the sealing direction
I cut it out. By T peeling of the seal part of the cut film
Was measured at a peeling speed of 300 mm / min.
Was.

(7) Hot tack stress: Using a hot tack tester manufactured by Teller, a metal die as an upper hot plate, a silicon rubber coating die as a lower hot plate, sealing time of 0.2 seconds, sealing pressure of 2 kg / cm ² , peeling Speed 200
0 mm / min, the peeling stress 0.187 seconds after the start of peeling,
Observation was performed at 90 ° C. and 100 ° C. using a 1-inch wide film, and the following judgment was made.・ Hot tack stress of 90 ° C. ○: A stress of 1.2 N / inch or more at 90 ° C. X: When a stress of 1.2 N / inch or less is exhibited at 90 ° C.・ Hot tack stress of 100 ° C. ○: A stress of 1.5 N / inch or more at 100 ° C. ×: When a stress of 1.5 N / inch or less is shown at 100 ° C.

(8) Low-temperature sealability: Low-temperature sealability was measured as an automatic liquid filling performance. evaluated. The low-temperature sealability was measured by using an automatic liquid filling device (Supercomac: Komatsu Ltd.) at a sealing speed of 22 m / min, a vertical seal temperature of 195 ° C., and filling with water (23 ° C.) as a film width of 1 film width.
Water filling amount 12g at 30mm, horizontal seal pitch 80mm
Under the conditions described above, the horizontal sealing temperature was lowered from 170 ° C. in steps of 5 ° C. to prepare bags filled with water at each temperature, and the bags were evaluated. The low-temperature sealability is determined by the high horizontal sealing temperature at which the unsealed portion occurs in the horizontal seal portion of the obtained bag, or by placing the sealed bag of the horizontal seal portion horizontally in the obtained bag and placing it on this bag. A load of 100 kg was applied for 1 minute at 23 ° C. to obtain a high horizontal sealing temperature at which the bag broke or leaked.

(9) External appearance of the horizontal seal portion: The external appearance of the horizontal seal portion was observed as the liquid automatic filling performance. The appearance of the horizontal seal is
Using a liquid automatic filling device (Supercomac: Komatsu Ltd.), sealing speed 22 m / min, vertical sealing temperature 195 ° C., water (23 ° C.) as filling material, film width 13
Under the conditions of 0 mm and a horizontal seal pitch of 80 mm and a water filling amount of 12 g, the horizontal seal temperature was increased from 140 ° C. in increments of 5 ° C. to prepare bags filled with water at each temperature, and the bags were evaluated. The appearance of the horizontal seal portion was a low horizontal seal temperature at which water remained in the horizontal seal portion of the obtained bag and foaming of about 1 mm was observed.

Examples 1-4 and Comparative Examples 1-11 Film Production Method Ethylene-hexene-1 copolymer (SPE) for the intermediate layer and sealant layer shown in Table 1 and high-pressure low-density polyethylene (LDPE) ), 200 ppm of calcium stearate and 500 ppm of Irganox 1076 manufactured by Ciba Specialty Chemicals Co., Ltd. were added, followed by dry blending with a corn blender, followed by FS65 manufactured by Ikegai Iron Works Co., Ltd. Using an extruder, melt-kneading was performed under the conditions of a resin temperature of 190 ° C., a discharge rate of 40 kg / hour, and a screen mesh of 80/100/120/120/80 to obtain a pellet-shaped resin used for the intermediate layer and the sealant layer. . Using a 90 mmφ × 2 tandem extrusion laminator, using ONy (15 μm) as the surface base material layer, applying and drying an isocyanate-based anchor coating agent on one surface of ONy, and applying No. to the ONy side coated with the anchor coating agent. . The extruder was used to extrude and laminate the resin of the intermediate layer at a resin temperature of 290 ° C. while using ozone treatment. 2. Extrude and laminate the resin of the sealant layer with an extruder and turn it on as the surface base material layer.
y, a three-layer film laminated in the order of the intermediate layer and the sealant layer was produced. The thickness of the manufactured three-layer film is
ONy was 15 μm, the intermediate layer was 20 μm, and the sealant layer was 30 μm.

Evaluation of Properties of Resin and Film The properties of the resin used for the intermediate layer and the sealant layer and the properties of the resulting three-layer film were evaluated. The results are shown in Table 2.

[0059]

[Table 1]

[0060]

[Table 2]

[0061]

The packaging film of the present invention can provide a film having excellent film appearance, excellent low-temperature sealability, and excellent seal appearance at high temperatures. When the packaging film of the present invention is used for automatic packaging, it is possible to provide a film which is excellent in low-temperature sealing properties and excellent in appearance of a sealing portion at high temperatures. When the packaging film of the present invention is used for automatic liquid packaging, it is possible to provide a film having an excellent seal appearance at high temperatures. The packaging film of the present invention is excellent in productivity because it uses a resin composition having a small neck-in of the film and excellent film-forming properties.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 3E086 AD01 BA04 BA15 BB51 CA01 4F100 AK01C AK06A AK06B AK41 AK46 AK62A AK62B AK63 AK68 AL05A AL05B BA03 BA05 BA07 BA10B BA10C BA26 BA27 EH232 EJ132 Y15B JA13 J15B

Claims (3)

[Claims] 1. A multilayer packaging film having at least a surface base material layer, an intermediate layer and a sealant layer laminated in this order, wherein the intermediate layer comprises an ethylene-α-olefin produced from a metallocene catalyst. Polymer (A) 50-9
The ethylene-α-olefin copolymer (A) made of a resin composition containing 5% by weight and a high-pressure method low-density polyethylene (B) in an amount of 50 to 5% by weight has a melt flow rate of 1 g / 10. Min to 18 g / 10 min, and the density is 0.940 g exceeding 0.908 g / cm ^3.
/ Cm ³ , and the high-pressure method low-density polyethylene (B)
Has a melt flow rate of 0.5 g / 10 min to 15 g /
10 minutes, and the density is 0.910 g / cm ^{3 to} 0.94
0 g / cm ³ , and the sealant layer is composed of a resin composed of 57 to 92% by weight of an ethylene-α-olefin copolymer (A) produced from a metallocene catalyst and 43 to 8% by weight of a high-pressure low-density polyethylene (B). The ethylene-α-olefin copolymer (A) composed of the composition and produced from the metallocene catalyst has a melt flow rate of 6 g / 10 min to 23.
g / 10 minutes, and the density is 0.887 g / cm ^{3 to} 0.
908 g / cm ³ , and the high pressure method low density polyethylene (B) has a melt flow rate of 0.5 g / 10 min to 1 g / cm ^3.
3 g / 10 min and a density of 0.910 g / cm ³ ~
A packaging film having a weight of 0.927 g / cm ³ . 2. The packaging film according to claim 1, wherein the packaging film is an automatic packaging film. 3. The packaging film according to claim 1, wherein the packaging film is an automatic packaging film for liquid filling.