JPH02155718A - Manufacture of oriented laminate film - Google Patents

Abstract

PURPOSE:To enhance such properties as heat resistance, interlayer bonding properties, mechanical strength, transparency, heat sealing properties and the like by laminating an intermediate layer consisting of a given alpha-olefin copolymer on a polyolefin layer, and then orienting the same in one direction and laminating a poly 4 - methyl - 1 - pentane layer on the intermediate layer of said oriented material, and then orienting the same in the direction at least square to said direction. CONSTITUTION:An intermediate layer constituted of an alpha-olefin copolymer of 10-85 mol % of propylene content, 3-60 mol % of 1 - butane content and 10-85 mol % of alpha-olefin content having 5 or more of carbon atoms and also 20% or less crystallization degree by the X-ray diffractometry is laminated on a polyolefin layer. Then, said lamina is oriented in one direction. Then, a poly 4 methyl - 1 - pentane layer is laminated on an intermediate layer of said oriented material, and then thus provided laminate is oriented in the direction at least square to said direction. The amount of 80-20 wt. % of alpha-olefin copolymer and 20-80 wt. % of poly 4 - methyl - 1 - pentane can be applied to the intermediate layer.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a method for producing a stretched laminated film, and more particularly to a method for producing a stretched laminated film having excellent heat resistance, mechanical strength, transparency, and the like.

Technical background of the invention and its problems Poly-4-methyl-1-pentene has excellent transparency, heat resistance,
Due to its chemical resistance properties, it is used as a coating material for chemical experiment equipment such as beakers and graduated cylinders, syringes for syringes, cells for optical measurements, microwave oven trays, and baking carton paper. As described above, poly4-methyl-■-pentene has a high melting point and good heat resistance, but has the problem of poor heat sealability. In order to improve the heat-sealability of such poly-4-methyl-1-pentene, it is necessary to use polyethylene, polypropylene, etc., which have a lower melting point than poly-4-methyl-1-pentene, and which also have poor heat-sealability. The most common method is to bond a high quality resin with poly(4-methyl-1-pentene), but although polyethylene or polypropylene and poly(4-methyl-1-pentene) are the same polyolefin, they have poor adhesion and are simply Simply laminating the two directly is not practical at all. Furthermore, even if a urethane-based adhesive or the like is applied as an anchor coating agent to a poly-4-methyl-1-pentene film and a polyethylene film or the like is laminated, the poly-4-methyl-1-pentene film has poor surface wettability. The interlayer adhesive strength of the laminated film was low, and the heat sealability of this laminated film was not very good.

In order to solve these problems, the present inventor developed a poly4
- To improve the heat sealability of methyl-1-pentene film (as a result of various studies, it was found that when laminating poly4-methyl-1-pentene film and polyethylene film or polypropylene film, specific propylene φα - It was found that the interlayer adhesive strength was further improved by using an olefin random copolymer or a composition consisting of this copolymer and poly4-methyl-1-pentene, but upon further investigation, The present inventors have discovered that if each layer of this laminated film is stretched using a specific method, a stretched laminated film with excellent mechanical strength, heat resistance, transparency, etc. can be obtained, and the present invention has been completed. .

Purpose of the Invention The present invention aims to solve the problems associated with the prior art as described above, and is aimed at solving the problems associated with the prior art as described above. The object of the present invention is to provide a method for producing a stretched laminated film.

Summary of the Invention The first method for producing a stretched laminated film according to the present invention is to provide a polyolefin layer (C) with a propylene content of 10 to 10%.
85 mol% and the 1-butene content is 3 to 60
mol%, the content of α-olefins having 5 or more carbon atoms is 10 to 85 mol%, and the degree of crystallinity as measured by X-ray diffraction is 20% or less. After laminating the layer (B), the resulting laminate is stretched in one direction, and then a poly-4-methyl-1-pentene layer (A) is laminated on the intermediate layer (B) of the resulting stretched product. , the obtained laminate is stretched at least in a direction perpendicular to the above direction.

Further, in the second method for producing a stretched laminated film according to the present invention, a propylene content of 1 is added on the polyolefin layer (C).
0 to 85 mol% and 1-butene content is 3 to 85 mol%
60 mol%, the content of α-olefins having 5 or more carbon atoms is 10 to 85 mol%, and the degree of crystallinity as determined by X-ray diffraction is 20% or less. ) and poly4-methyl-1-pentene (b)
After laminating the intermediate layer (B), the resulting laminate is stretched in one direction, and then a poly-4-methyl-1-pentene layer (A) is placed on the intermediate layer (B) of the stretched product. After lamination, the resulting laminate is stretched at least in a direction perpendicular to the above direction.

Since the method for producing a stretched laminated film according to the present invention has the above-mentioned characteristics, it is possible to produce a stretched laminated film with excellent properties such as heat resistance, interlayer adhesive strength, heat sealability, mechanical strength, and transparency. can be manufactured.

Detailed Description of the Invention The method for producing the first stretched laminated film according to the present invention will be specifically described below.

In the first stretched laminated film produced in the present invention, poly-4-methyl-1-pentene is used as the layer (A), and this poly-4-methyl-1-pentene is
Homopolymers of 4-methyl-1-pentene or 4-methyl-1-pentene and other α-olefins, such as ethylene, propylene, l-butene, l-hexene,
A copolymer with an α-olefin having 2 to 20 carbon atoms such as octene, l-decene, l-tetradecene, and 1-octadecene, and usually contains 4-methyl-1-pentene in an amount of 85 mol% or more. It is a polymer mainly composed of 1-pentene. The melt flow rate of poly-4-methyl-1-pentene (MFR5, load: 5 kg, temperature = 260°C) is
Preferably it is in the range of 0.5 to 200 g/10 minutes. If the melt flow rate is less than 0.5 g/10 minutes, the melt viscosity will be high and the moldability will be poor;
If it exceeds 0 g/10 minutes, the melt maximum viscosity will be low, the moldability will be poor, and the mechanical strength will also tend to be low.

In the first stretched laminated film produced according to the present invention, an α-olefin copolymer is used as the intermediate layer (B). This α-olefin copolymer contains propylene, I-butene and carbon atoms of 5 or more, preferably 6.
-12 α-olefins (hereinafter sometimes simply referred to as α-olefins), and this α-olefin copolymer has a propylene content of 10 to 8
5 mol%, preferably 15 to 70 mol%, more preferably 25 to 55 mol%, and ■-butene 3 to 60 mol%, preferably 5 to 50 mol%, more preferably 1
0 to 40 mol%, and the α-olefin is 10 to 85 mol%.
mol%, preferably 15 to 70 mol%, more preferably 20 to 60 mol%, and the crystallinity measured by X-ray diffraction is 20% or less, preferably 15% or less, and even more preferably 10% or less. This is desirable.

The α-olefins having 5 or more carbon atoms include l-pentene, 3-methyl-■-butene, ■-hexene, 4-
Methyl-■-pentene, 3-methyl-1-pentene, ■
Examples include -heptene, -octene, -decene, and -dodecene.

In such α-olefin copolymers, whether the propylene content is less than 10 mol% or more than 85 mol%, and even if the 1-butene content is less than 3 mol%, it is 60 mol%. Even if the α-olefin content is less than 10 mol% or more than 85 mol%, the α-olefin copolymer intermediate layer (B) and the poly 4-methyl- The adhesive strength with the 1-pentene layer (A) tends to be poor.

In addition, α-
The olefin copolymer intermediate layer (B) tends to have poor adhesion to the poly4-methyl-1-pentene layer (A).

The crystallinity of the α-olefin copolymer used in the present invention was determined by X-ray diffraction when the sample was
After compression molding for 10 minutes under the conditions of d, it was cooled for 5 minutes with a water-cooled press (pressure crab 30 kg/cJ) adjusted to 23 ° C., and a test piece of 2cIIIX4CI11×11■ was molded.
After measuring the X-ray diffraction curve of this test piece at a diffraction angle (2θ) of 5 degrees to 31 degrees using a rotating anticathode X-ray diffraction device (Rll-800, manufactured by Rigaku Denki ■) equipped with a copper target. , a baseline was drawn between diffraction angles (2θ) of 6 degrees and 30 degrees, and the values for the amorphous and crystalline portions were determined based on the crystalline portion as weight percent.

The α-olefin copolymer used in the present invention usually has an intrinsic viscosity [η] (value measured at 135°C in a decalin solvent) of 0.6 to 6 dJ2/g, preferably 0.5 to 5
dN/g, even 1.0 to 4 dll! /g range. When the intrinsic viscosity [η] is less than 0.6 dfl/g or more than 6 dll/g, moldability may be poor.

The α-olefin copolymer used in the present invention preferably has a boiling rhobutane insoluble content of 5.0% by weight or less and an acetone soluble content of 560% by weight or less at 25°C, Further, it is preferable that the content insoluble in boiling n-hebutane is 4.0% by weight or less, and the content soluble in acetone at 25°C is 2.5% by weight or less. g
! pIII If the content insoluble in n-heptane exceeds 5% by weight, the transparency of the α-olefin copolymer may decrease or cause fish eyes when this α-olefin copolymer is formed into a film. There is a possibility. In addition, the acetone soluble content is 5. If the amount of OfI exceeds %, stickiness occurs on the surface of the α-olefin copolymer intermediate layer (B), which is a cause of a decrease in adhesive performance with, for example, the poly-4-methyl-1-bentine layer (A), etc. There is a possibility that this will happen. In addition, the α-
The boiling n-hebutane insoluble content and the acetone soluble content at 25°C of the olefin copolymer were measured by the following methods.

That is, the n-hebutane insoluble portion is approximately 1 fin x 1 dragon x 1 m.
A strip sample of about 1.0 m in size and glass peas were placed in a cylindrical glass filter and extracted for 14 hours using a Soxhlet extractor, and the weight percent of the insoluble matter was determined by weighing the dissolved or insoluble matter.

In addition, the 25°C acetone soluble content was sample 15. was dissolved in 250 ml of n-decane at 130℃, and this was dissolved in 250 ml of n-decane at 130℃.
ml of acetone to precipitate the acetone-insoluble polymer, collect the filtrate by filtration, and then add 300ml of water to the filtrate.
ml, the n-decane layer and the water-acetone layer were separated using a separating funnel, and the n-decane layer was concentrated.

The α-olefin copolymer having the above-mentioned properties used in the present invention is, for example, (a) a highly active solid titanium catalyst component (a) consisting of a magnesium compound, a titanium compound, and an electron donor, and a halogenated hydrocarbon ( Propylene, l-butene and It is obtained by random copolymerization of the α-olefin. Methods for preparing such catalysts are described in Japanese Patent Application Laid-open Nos. 56-811 and 58.
-83006, etc. In addition, the polymerization conditions of the α-olefin copolymer are disclosed in Japanese Patent Application Laid-Open No. 60-16
It is explained in Japanese Patent No. 6310.

In the present invention, a polyolefin is used as the layer (C), and this polyolefin is a polyolefin mainly composed of α-olefin having 2 to 4 carbon atoms, that is, a crystalline polyolefin mainly composed of ethylene, propylene, and 1-butene. It is a polymer of Specifically, these polyolefins include ethylene polymers, propylene polymers, and
-Butene-based polymers may be mentioned. These polyolefins are not limited to homopolymers, but are also α-
As long as the main component is an olefin, copolymers of this α-olefin and other α-olefins having 2 to 20 carbon atoms or vinyl compounds such as vinyl acetate, vinyl chloride, acrylic acid, methacrylic acid, and styrene may also be used. Alternatively, a graft copolymer graft-modified with an unsaturated carboxylic acid such as maleic anhydride, maleic acid, or acrylic acid or a derivative thereof may be used. The polyolefin may also be a mixture of the above-mentioned polyolefins at °C.

Specific examples of the ethylene polymer used as the layer (C) include high-pressure low-density polynyletine (so-called L
DPE), ethylene biopropylene copolymer, ethylene-
1-butene copolymer, ethylene-4-methyl-1-pentene copolymer, ethylene-1-hexene copolymer, high-density polyethylene (so-called HDPE), ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer Examples include polymers. Among these, LDPE, ethylene/α-olefin copolymer, ethylene/vinyl acetate copolymer, etc. are preferable because they have excellent transparency and low-temperature heat sealability. These LDPE, ethylene/α-olefin copolymer, ethylene/vinyl acetate copolymer, etc. have a density of 0.910 to 0.
．． 960g/c+4, and the melting point (Ta:
More preferably, the temperature (ASTM D 841B) is 100 to 135°C. -The melt flow rate of polyethylene (MFR3: ASTM D 1238.E)
Although not particularly limited, it is usually 0.0 from the viewpoint of moldability.
1-30 g/1.0 min, more preferably 0.1
It is desirable to be in the range of ~10 g/10 minutes.

Specific examples of the propylene polymer used as layer (C) include polypropylene (propylene homopolymer), propylene/ethylene random copolymer, propylene/ethylene/1-butene random copolymer, and propylene/i- Propylene random copolymer such as butene random copolymer (propylene content is usually 90 mol 5 or more, preferably 95 mol % or more)
, a propylene/ethylene block copolymer (ethylene content is usually 5 to 30 mol%), and the like.

Among these, homopolymers and random copolymers are preferable because they have excellent transparency, and are especially preferable due to their melting point (T: AS
A random copolymer having a TMD 841g) of 130 to 140°C is preferable because it has excellent heat sealability. Note that the MFR2 of polypropylene is not particularly limited, but from the viewpoint of moldability, it is usually 0.5 to 30 g / 1
0 minutes, more preferably in the range of 0.5 to 10 g/10 minutes.

Further, specific examples of the l-butene polymer used as the layer (C) include l-butene homopolymer, ■-
Examples include butene φ ethylene copolymer, ■-butene φ propylene copolymer, and 1-butene 4-methyl-1-pentene copolymer. The melt flow rate (MPR3: ASTM D1238, E) of this poly-1-butene is not particularly limited, but is usually 0.01 from the viewpoint of moldability.
~100 g/10 min, even 0.03-30
A range of g/10 minutes is preferred.

The stretched laminated film of the present invention comprises the poly-4-methyl-1
- The polyolefin layer (C) is laminated on at least one side of the pentene layer (A) via the α-olefin copolymer intermediate layer (B), and these layers (A), (B) and (C ) is a laminated film formed by stretching.

In this stretched laminated film, the polyolefin layer (C) serves as a heat seal layer.

The first stretched laminated film according to the present invention is manufactured as follows.

That is, after laminating the above-mentioned intermediate layer (B) on the polyolefin layer (C) by a co-pressing method or the like, the obtained laminate is laminated in one direction, preferably in the longitudinal direction (machine direction) by 2 to 1
Stretched 5 times, then poly 4-methyl-
(2) After laminating the pentene layer (A), the stretched laminated film according to the present invention is produced by stretching at least 3 to 15 times in a direction perpendicular to the above direction, preferably in a transverse direction.

In some cases, after laminating a poly4-methyl-1-pentene layer (A) on a stretched product obtained by laminating an intermediate layer (B) on a polyolefin layer (C) and then stretching in one direction, , it is also possible to stretch in two axes, transverse and longitudinal.

In this way, after laminating the intermediate layer (B) on the polyolefin layer (C) in advance, the resulting laminate is stretched in one direction, and then the stretched product is coated with poly4-methyl-1-pentene. If a stretched laminated film is produced by a specific step of laminating the layer (A) and then stretching at least in a direction perpendicular to the above direction, a stretched laminated film with particularly excellent interlayer adhesion and also excellent heat resistance can be obtained. .

As a coextrusion molding method, T-
There is a die method and an inflation method using a circular die. The flat die may be either a single manifold format using a black box or a multi-order manifold format. As for the die used in the inflation method, any known die can be used.

The stretched laminated film according to the present invention obtained in this way has improved mechanical strength, heat resistance, transparency, etc. compared to an unstretched film.

In the first stretched laminated film according to the present invention obtained by stretching in this way, the thickness of each layer is not particularly limited, but the thickness of the poly4-methyl-1-pentene layer (A) is 5.
00 to 1 μm, preferably 50 to 3 μm, and the thickness of the α-olefin copolymer intermediate layer (B) is 300 to 1 μm.
μm1 is preferably 30-2 μm, and the thickness of the polyolefin layer (C) is 800-1 μm1, preferably 50-2 μm.
The thickness is preferably 3 μm.

Next, a method for producing the second stretched laminated film according to the present invention will be explained.

In the stretched laminated film obtained by the second production method according to the present invention, the layer (A) and the layer (C) are the same as the first stretched laminated film according to the present invention, and the intermediate layer (B
) are different. In this second stretched laminated film,
The intermediate layer (B) has a propylene content of 10 to 85 mol%
and the content of 1-butene is 3 to 60 mol%, and the content of α-olefin having 5 or more carbon atoms is 10 to 60%.
It consists of an α-olefin copolymer (a) having a crystallinity of 85 mol % and a crystallinity of 20% or less as measured by X-ray diffraction and poly-4-methyl-1-pentene (b).

The α-olefin copolymer (A) constituting the intermediate layer (B) is the same as that used for constituting the layer (C) in the first stretched laminated film according to the present invention as described above. The same copolymers as α-olefin copolymers are used.

Moreover, the poly-4-methyl-1-pentene (B) constituting the intermediate layer (B) is the same as the poly4-methyl-1-pentene (B) used to constitute the layer (A) in the first stretched laminated film according to the present invention as described above. Something similar to 4-methyl-1-pentene is used.

In the intermediate layer (B) of the second stretched laminated film according to the present invention, the α-olefin copolymer (A) is 80 to 2
Poly4-methyl-1-pentene (b) in an amount of 0% by weight
is preferably used in an amount of 20 to 80% by weight,
More preferably, the α-olefin copolymer (a) is 7
Poly4-methyl-1-pentene (b) is preferably used in an amount of 30 to 60% by weight.

The amount of α-olefin copolymer (a) exceeding 80% by weight based on the total 100% by weight of α-olefin copolymer (a) and poly4-methyl-1-pentene (b) or in an amount less than 20% by weight, the interlayer adhesion of the stretched laminated film tends to decrease, the heat shrinkage rate of the stretched laminated film increases, and the heat resistance tends to decrease.

The composition for forming the intermediate layer can be obtained by blending the above-mentioned α-olefin copolymer (a) and poly4-methyl-1-pentene (b) using a Henschel mixer V-type blender or the like. or by blending using a single screw extruder or a multi-screw extruder.

The second stretched laminated film according to the present invention has an intermediate layer (B)
The first stretched laminate according to the present invention, except that the composition for forming an intermediate layer consisting of the α-olefin copolymer (a) and poly-4-methyl-■-pentene (b) is used as described above. It is manufactured in the same way as film.

In the second stretched laminated film according to the present invention, the thickness of each layer is approximately the same as the thickness of each layer in the first stretched laminated film according to the present invention.

The stretched laminated film according to the present invention obtained as described above is composed of a poly4-methyl-1-pentene layer (A), an intermediate layer (B), and a polyolefin layer (C), If necessary, a polyolefin layer (C) may be laminated on both sides of the poly-4-methyl-1-pentene layer (A) via an intermediate layer (B). For application, polyvinylidene chloride resin, polyvinyl alcohol, saponified ethylene/vinyl acetate copolymer, polyamide, polyester, paper, aluminum foil, etc. may be laminated.

Further, a poly4-methyl-1-bendine layer (A), an intermediate layer (B) as described above, and a polyolefin layer (C) constituting the stretched laminated film obtained by the production method according to the present invention.
Any layer or all layers may contain additives such as weathering stabilizers, heat stabilizers, antistatic agents, antifogging agents, antiblocking agents, slip agents, lubricants, pigments, dyes, droplet agents, nucleating agents, etc. Various compounding agents that are normally added to polyolefins may be added to the extent that they do not impede the purpose of the present invention.

In the stretched laminated film according to the present invention, the polyolefin layer (C) contains a low-crystalline or non-quality ethylene-propylene copolymer, an ethylene- Ethylene Φα-olefin copolymers such as polymers, ethylene/vinyl acetate copolymers, etc. may be added.

The stretched laminated film according to the present invention takes advantage of the above-mentioned properties and is preferably used as a packaging material for various foods such as vegetables, confectionery, meat, bread, marine products, etc., or as a coating material for baking carton paper and the like.

In addition, the stretched laminated film obtained using the method for producing a stretched laminated film according to the present invention has a poly-4-methyl-1-pentene layer (outer layer) with higher heat resistance than a conventional biaxially stretched polypropylene film. Because of the good quality, LDPE was added to this stretched laminated film 1 as shown in FIG.
, EVA1 non-stretched PP or other heat-sealable film 2 is bonded to the composite film 3, which enables heat-sealing using a heat-sealing bar 4 set at a high temperature during bag making.
Bags can be made at high speed.

Effects of the Invention Since the stretched laminated film according to the present invention has the above-described laminated structure, it has excellent heat resistance, interlayer adhesion, chemical resistance,
It has excellent properties such as heat sealability, mechanical strength, and transparency.

Furthermore, since the packaging material according to the present invention is made of the stretched laminated film as described above, it has excellent properties such as heat resistance, interlayer adhesion, chemical resistance, heat sealability, mechanical strength, and transparency. .

[Example] Next, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited to these examples in any way.

Example 1 Polypropylene (melt flow rate: 1,
'zr/10 min (ASTM D 1238:L) Melting point:
161℃ (Product name: Mikata Petrochemical Polypro F301
(hereinafter abbreviated as PP-1)) manufactured by Mikata Petrochemical Industry (■) was used.

In addition, the composition for forming the intermediate layer (B) and L7, 4
-Methyl-1-pentene/l-decene copolymer (density:
0.835r/cn, MFR: 26g110min (hereinafter 4
abbreviated as MP-1)) and propylene, 1-butene, 4-
Methyl-1-pentene copolymer (propylene content = 3
6 mol%, l-butene content: 14 mol%, 4-methylpentene-1 content: 50 mol%, glass transition point (Tg
): 5°C, density (D): 0.860r/cn, MFR:
0.88g/10min, crystallinity by X-ray: 1.2% (
Hereinafter abbreviated as PBM-1)) is 4MP-1/PBM-
1-50 was blended in an amount of 150% by weight.

The above pp-i and the composition for forming an intermediate layer were molded using a coextrusion T-die molding machine to create a sheet with a two-layer structure consisting of layer (C) and layer (B).

The extruder for layer (C) has a diameter of 90 mm, and the resin temperature is 28
The extruder for layer (B) was 65mm diameter, and the resin temperature was 270°C. The thicknesses of layer (C) and layer (B) were 400 μm and 100 μm, respectively.

The sheet with the two-layer structure obtained as described above is then passed through a cast roll and a preheating roll, and between two stretching rolls (set temperature 130°C), the sheet is stretched five times in the longitudinal direction (machine direction). It was stretched. After stretching, 4MP-1, which is the same as that used to form the intermediate layer, is laminated on the surface of layer (B) by melt extrusion using a single-layer T-die to form layer (B).
A poly-4-methyl-1-pentene layer was formed on the surface.

The extruder for layer (A) has a diameter of 65 fins, the resin temperature (melting temperature) is 300°C, and the film thickness of layer (A) is 10°C.
It was 0 μm. Continued layer (C), layer (B), layer (A)
A sheet with a three-layer structure consisting of
℃) and stretched 8 times in the transverse direction.

The stretching rolls in the machine direction and the device for stretching in the lateral direction in the tenter used in the above examples are two types of polypropylene.
The one for producing stretched film was used.

The physical properties of the obtained stretched laminated film were evaluated by the following method.

Tensile strength: i'll according to ASTM D 638
+ Established.

However, if the dumbbell shape is used as a type, The tensile speed was 200 mm/min.

Heat shrinkage rate (%): 1100mm x 100 on the film in advance
After marking the marked line (2) and leaving it in an oven at 120°C to 220°C for 30 minutes, the distance between the marked lines was measured, and the value (before shrinkage - after shrinkage)/before shrinkage was determined as a percentage.

Heat-sealing strength (g/15 nm): The films were stacked and heat-sealed at a temperature of 180°C to 220°C and a pressure of 2 kg/c- for 1 second with a seal bar width of 5 am, and then allowed to cool. From this sample 1
A test piece with a width of 5 mm was cut out, and a single-shaped peel test was conducted at a peel rate of 300 a+m/1n.

Delamination strength (g/15us): Cut a 1511-width test piece and crosshead speed 300III/s
It is shown by the strength when peeled between each resin layer.

8 degrees (%): ASTM D 10031. : Compliant with Tefi-1.

The results are shown in Table 1.

Example 2 The same procedure as in Example 1 was conducted except that the mixing ratio of 4MP-1 and PIIM-1 used in Example 1 was as shown in Table 1.

The results are shown in Table 1.

Comparative Example 1 The intermediate layer PBM-1 used in Example 1 was used alone as an intermediate layer (
The same procedure as in Example 1 was carried out except that B) was used.

The results are shown in Table 1.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a composite film obtained using the method for producing a stretched laminated film according to the present invention, when the composite film is heat-sealed. 1...Stretched laminated film 2...Heat sealable film 3...Composite film 4...Heat seal bar

Claims (1)

[Scope of Claims] 1) On the polyolefin layer (C), the propylene content is 10 to 85 mol% and the 1-butene content is 3.
~60 mol%, and the α-olefin content having 5 or more carbon atoms is 10 to 85 mol%, and the crystallinity as determined by X-ray diffraction is 20% or less. After laminating the intermediate layer (B), the obtained laminate is stretched in one direction, and then a poly-4-methyl-1-pentene layer (A) is formed on the intermediate layer (B) of the stretched product. A method for producing a stretched laminated film, which comprises stretching the obtained laminate at least in a direction perpendicular to the above direction after lamination. 2) On the polyolefin layer (C), the propylene content is 10 to 85 mol% and the 1-butene content is 3
~60 mol%, and the content of α-olefins having 5 or more carbon atoms is 10 to 85 mol%, and the degree of crystallinity as determined by X-ray diffraction is 20% or less ( After laminating the intermediate layer (B) consisting of a) and poly4-methyl-1-pentene (b), the resulting laminate is stretched in one direction, and then the intermediate layer (B) of the resulting stretched product is laminated.
A method for producing a stretched laminated film, which comprises laminating a poly-4-methyl-1-pentene layer (A) thereon, and then stretching the resulting laminate at least in a direction perpendicular to the above direction.