JPS62176843A - Polyolefin laminated film and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a dispenser (cutting tool) that has 9-hand tearability (hereinafter referred to as hand-tearability), impact resistance, moisture resistance, and is processed into an adhesive tape. The present invention relates to a laminated film that has excellent tearability with a cutting blade (hereinafter referred to as dispenser cuttability) and a method for producing the film.

[Conventional technology]

Conventionally, adhesive tapes have been made using polyolefin films such as polypropylene (hereinafter abbreviated as PP) as a material (for example, Japanese Utility Model Publication No. 16053/1983).

A laminated film of a biaxially stretched film and a uniaxially stretched film in the width direction (for example, Utility Model Publication No. 50-41271)
An example of improving the cutability by hand by using a polypropylene film (Japanese Patent Application Laid-open No. 74774/1982) and an example of improving the cutability by using a film containing 25 to 35 wt% petroleum resin to polypropylene (for example, Japanese Patent Application Laid-Open No. 74774/1983) (Japanese Unexamined Patent Publication No. 57-96858), etc., using a polypropylene copolymer having a low intrinsic viscosity.

Furthermore, bags made of polyolefin such as PP are flexible and have excellent tensile strength.

Although it is widely used, it is difficult to open with one hand and does not have sufficient moisture resistance in the food packaging field. Therefore, as a means of improving unsealability, a method of coating with the above-mentioned excellent vinylidene chloride resin has been used.

[Problem that the invention seeks to solve]

All of the conventional means for improving hand-tearability are accompanied by a decrease in impact strength, so they have the disadvantage that they cannot be used particularly for packaging tapes or easily breakable gas-filled packaging for food packaging.

Also, Publication No. 50-16053, and Publication No. 50-16053,
In the case of JP-A No. 0-41271, the hand-cutting property is improved, but the film tends to stretch in the longitudinal direction, and the dispenser-cutting property is not sufficient.
In the case of Publication No. 74, the dispenser cuttability was not sufficient and the directionality when cutting nine hands was not linear and random, which was also a drawback.

Furthermore, the vinylidene chloride coating method as a means for improving moisture resistance also has the drawbacks of poor durability and productivity, and easy yellowing.

The present invention solves the above problems, provides good manual tearability, and
I impact resistant, moisture resistant and dispenser. The object of the present invention is to provide a laminated film that has cuttability and can be cut beautifully in straight lines, and a method for manufacturing the film.

[Failure to solve the problem]

The present invention mainly consists of 10 to 3 Qwt% of petroleum resin and 70 to 90wt% of polyolefin, and the polyolefin has an ethylene component and a propylene component of 0.5 to 50 w, respectively, based on the sum of the weight of the petroleum resin and the weight of the polyolefin.
3% and 20 to 89.5w 3%, and a layer (B) uniaxially stretched in the transverse direction consisting of a composition mainly composed of
wt%) is the proportion of the propylene component in layer (A) (w
t%) Yoshi is also more than 5 wt%.

And the birefringence of the 9 layers (A) and the layer (B) is Δn
A polyester in which Ao(ΔnB/ΔnA) is 2 to 65.

It is characterized by a laminated film.

First, the 9th layer (A) will be explained.

Petroleum resin refers to a polymer obtained by catalytic polymerization of 7-mer obtained by thermal decomposition of petroleum, or a hydrogenated product of this polymer, and generally includes terpene, [L< is cyclopentadiene, styrene] , methylstyrene, vinyltoluene, indene, methylindene, butadiene, imprene.

The monopolymer composed of monomers such as piperylene and bentylene may be a homopolymer or a mixture of one type of these monomers, or a copolymer of several types of these monomers.

Polyolefin is a polymer whose main components are ethylene and propylene, and may also contain other components such as butene, pentene, hexene, and 4-methylpentene.

Ethylene component means ethylene mono≦H2−CH,)−
Specifically, it is composed of polyethylene and/or a copolymer with other monomers (ethylene-
Examples include propylene copolymers, ethylene-butene copolymers, random copolymers, block copolymers, etc.).

The propylene component is composed of propylene monomers H3 + CH-CH2+, and specifically includes polypropylene and/or copolymers with other monomers (ethylene-propylene copolymer, butene-propylene copolymer). Random with polymers, etc.

block copolymers, etc.).

The polypropylene referred to herein may be any known polypropylene, but preferably has an isotactic O index (hereinafter abbreviated as II) of 90% or more, more preferably 95% or more.

In addition, the melt flow index at 230°C (hereinafter M
(abbreviated as I) is preferably in the range of 1 to 20 g/10 minutes. .

Polyethylene may be low density, high density, linear low density polyethylene, etc.

High-density polyethylene with a density of 0.930 or more (preferably 0.940 or more) or linear low-density polyethylene is particularly preferred. Further, by using polyethylene having an MI of 1 or more, a semi-glossy matte film can be obtained.

Also, as a copolymer containing an ethylene component or a propylene component here.

(-CI, -CM, +nn≦2 ethylene component, that is, a random ethylene component (hereinafter abbreviated as ethylene component I), preferably an ethylene-propylene random copolymer (hereinafter abbreviated as E P RC) or.

), preferably an ethylene-propylene block copolymer.

EPRC ＼Chile y component is preferably 05 to 7 wt%,
More preferably, it is 1 to 5 wt%, and the MI at 230°C is preferably 1 to 20. More preferably, the number is in the range of 4 to 20. The ethylene component of EPBC is preferably 7
~50wt%, more preferably 15-40wt%, 2
ut of 30°0 is preferably 1-20. More preferably, the number is in the range of 4 to 20.

Note that other polymers may be mixed as long as the characteristics of the present invention are not impaired. Of course, known additives such as heat stabilizers, antioxidants, crystal nucleating agents, slipping agents, antistatic agents, antiblocking agents, viscosity modifiers, light stabilizers, etc. may be added.

Wt of ethylene component and propylene component in layer (A) below
% is e(A)! ==#Represents the content of ethylene component and propylene component with respect to the sum of the weight of 9 petroleum resin and the weight of polyolefin in the Fengm layer.

Next, 1-layer CB) will be explained.

What is the petroleum resin and polyolefin in layer CB)?

It is the same as layer (A), and it is preferable that #the polyolefin is mainly composed of propylene component.

In addition to the petroleum resin and propylene component, the layer (B) may contain other components (9), such as other α-olefins other than the propylene component, within a range that does not impair the characteristics of the present invention.

Known additives shown in layer (A) may be added.

As α-olefins other than propylene components.

Ethylene is particularly preferred, and its content is not particularly limited, but is preferably 20 wt% or less based on the total weight of the nine-layer (B) polymer.

Further, it is preferable that 9 petroleum resin is added to the first layer (B) since the cut portion will not whiten.

The laminated film of the present invention has 9 hand tearability and i'I impact resistance.

Moisture-proof and dispenser 〇 Good cutability.
Moreover, when cut by hand, the cut surface is straight.

In order to obtain such properties, the biaxially oriented layer (A) in the laminated film contains 10 to 30 wt% (preferably 12 to 25 wt%) of 9 petroleum resin and 70 to 90 wt% of polyolefin.
wt% (preferably 75 to [313wt, %)], and the polyolefin has an ethylene component and a propylene component of 0.5 to 50 wt% (preferably 5 to 50 wt%, respectively) based on the sum of the weight of the petroleum resin and the weight of the polyolefin. 48w
t%) and 20-89.5 w 5% (preferably 4
0 to 83 wt%).

The transversely-axially stretched layer (B) is 9 petroleum resin O ~ 20w
t% (preferably 1-1 f1wt4, more preferably 2-5 wt%) and polyolefin 80-100w
t%, and the polyolefin has a propylene component of 9% relative to the sum of the weight of the petroleum resin and the weight of the polyolefin.
Preferably 80-100 wt,%, more preferably 90
-99wt%, more preferably 95-98wt%, and the proportion (wt%) of the propylene component in layer (B) is the same as that of the propylene component in layer (A). 5 wt% than the ratio (wt%)
More than this is necessary.

In addition, the ethylene component of the 9th layer (A) is Q, 5wt% or more 5w
If it is less than t%, the ethylene component → is 0.5wt% or more5
It is particularly good that the ethylene component is less than 4 wt%, preferably 1 to 3 wt%, and the ethylene component is in the range of 0 to 4.5 wt%, preferably 0 to 4 wt%.

If the ethylene component of layer 9 (A) is 5 to 50 wt%, the ethylene component I is 0 to 5 wt%, preferably 0 to 3 wt%.
1%, ethylene component ■ is 0 to 50 wt%, preferably 5
-45wt%, more preferably 10-40wt%.

If the petroleum resin in layer (A) is less than 13 wt%, the laminated film will have poor dispenser cuttability and moisture resistance.

-! The petroleum resin in the 9th layer (A) exceeds 30 wt%. If the ethylene content of the layer (A) exceeds 50 wt.s, the moisture proofing properties will be decreased, and if it is less than 0.5 wt%, the impact resistance will decrease.

In addition, the amount of petroleum resin added in the 9th layer (B) is 20w
If it exceeds t%, even if one layer (B) is a transversely stretched layer, the linearity in the cutting direction when cutting with one hand will deteriorate. Furthermore, the proportion (wt%) of the propylene component in the 9th layer (B)
Ratio (wt%) of the propylene component in the layer (A)
) must be at least 5 wt%.9 When the birefringence of the layers (A), I and (B) of the laminated film of the present invention are respectively expressed as ΔnAlΔnn, 2≦ΔnB/ΔnA≦
It is necessary to satisfy the relationship 35. In order to obtain even better hand cutability and dispenser cuttability, it is preferable that 2.2≦ΔnB/Δ, ≦12.

Note that birefringence refers to the transverse refractive index 'TD of each layer of the film.
and the longitudinal refractive index nMnO difference nTゎ-"MD.

Although the thickness ratio of each constituent layer of the laminated film of the present invention is not particularly limited, the thickness ratio of one layer (A) to the entire film is preferably 95 to 50%, more preferably 80 to 60%.
It is. Also, the total thickness of the film is not particularly limited, but
The range is 10 to 150 μm, preferably 15 to 100 μm, and more preferably 20 to 60 μm.

Next, a single laminate film and a method for manufacturing the laminate film will be described.

PP, EPRC, EPBC, polyethylene, petroleum resin, etc. are mixed so that the ethylene component is 0.5 to 5 wt%, the propylene component is 895, and the propylene component is 895 and 5 to 20%, and melted at a resin temperature in the range of 180 to 260°C. - After mixing, the mixture is discharged from a slit-shaped nozzle and cast onto a cooling drum with a surface temperature of 40 to 110°C to cool and solidify.

The above cast film i is extruded through a slit-shaped die at a temperature range of 100 to 150, 0 to 20 wt.

Subsequently, the laminated film is fed into a tenter-type stretching device and stretched 8 to 12 times in the transverse direction. The stretching temperature in the transverse direction at this time was 145 to 165°C. Preferably 150-163°C
, and preferably 155 to 163° C. is the best condition for obtaining the laminated film of the present invention.

If the transverse stretching temperature is lower than 145°C, the film will break frequently and stable stretching cannot be performed. This is particularly noticeable when the thickness of layer (B) exceeds 50% of the total thickness.

When the thickness of the zero layer (A) exceeds 95%, the film tends to break frequently.

After stretching in the transverse direction, the stretched film may be heat-treated at 150 to 162° C. for 3 to 10 seconds while relaxing 0 to 10% in the width direction, if necessary.

A laminated film of the present invention is obtained.

The number of layers (A) in the laminated film of the present invention is preferably less than 4 in the longitudinal direction, and the number of layers (B) is preferably 9 in the width.

In addition, in the laminated film of the present invention, a polyolefin layer (
C), in particular, the polypropylene layer is laminated by coextrusion with the 9 layers (A), and then the film is formed by the above method, so that the laminated film has a layer configuration f: (C) / (A) / (B), or By setting (C) / (A) / (C) / (B), the stretching roll during film formation.

The adhesion of the T/R type stretching device to the clips is greatly improved. The thickness of the biaxially stretched layer (C) is 9. In order not to impair the effect of the present invention, when laminating on one side of the 9 layer (A), the thickness of a single layer is In the case of lamination, it is preferable that the sum of the thicknesses of the layers on both sides be 25% or less of the total thickness.

Furthermore, the film of the present invention is subjected to corona discharge treatment or plasma treatment in air, carbon dioxide gas, nitrogen gas, argon gas, etc. alone or in a mixed gas such as air, carbon dioxide, nitrogen gas, argon gas, etc. to reduce the surface tension to 35.
The surface adhesion may be improved by increasing d7na/as or higher, or conversely, only one side may be coated with a release agent.

Furthermore, polyethylene having a melt index of less than ft1 may be used as the polyethylene added to the first layer (A) and (B), or a polymer poorly compatible with polypropylene may be added within a range that does not impair the characteristics of the present invention.

Or calcium carbonate in layer (A) or layer (B),
A so-called mending tape in which drawing properties are imparted to the film by adding talc, dolomite, zeolite, kaolin, etc. or by embossing the surface of one layer (A) or layer (B). It may also be a semi-gloss film.

Alternatively, instead of directly adding the above-mentioned additives to the 9 layers (A) and (B), the above-mentioned additives are added to the polyolefin layer within a range that does not impair the characteristics of the present invention.

By laminating the laminated film of the present invention, drawing properties may be imparted or a semi-gloss film may be obtained.

In the case of processing the laminated film of the present invention into an adhesive tape, the film of the present invention is laminated with an adhesive layer having pressure-sensitive adhesive properties at room temperature, for example, an adhesive layer such as polyacrylic acid ester. Of course, lamination methods include solution or emulsion coating methods, and solvent-free extrusion coating methods.

There is no particular limitation, and of course, a release agent may be applied to the surface opposite to the surface to which the adhesive is applied in advance or after the adhesive is applied. The coating thickness is not particularly limited, but is usually 1.
It is set to 0 to 60μ.

When applying the adhesive to the entire film, an anchor coat layer or a modified polyolefin layer may be interposed between the adhesive layer and the film. The application methods are reverse roll method and gravure roll method.

Any method such as a kiss roll method, a doctor knife method, a curtain coater method, a fountain coater method, etc. can be used.

When making a packaging bag using the laminated film of the present invention, a heat-sealing layer (D) is provided on at least one surface of the film of the present invention.

The polymer forming the heat-sealing layer (I) is preferably a thermoplastic resin with a lower melting point than that of layer (A) and layer (B), such as ethylene-propylene random copolymer, ethylene-butene random copolymer, etc. Combined.

Propylene-butene copolymer, polyethylene, etc. are used. The thickness of the heat seal layer (D) may be any thickness, but is preferably 1 to 20 μm.

Layer CD) 't: The method of providing is a method of co-extrusion with layer (A) or layer (B), extrusion lamination alone, or a laminated polyolefin film or layer (D) with heat seal layer (D). ) may be laminated together.

The film of the invention is heat sealed with layer (D);
It can be processed into bags with three-sided seals, four-sided seals, central seals, pleated shapes, envelope shapes, etc.

A notch may be provided in the heat-sealed portion of the bag to further improve the ease of opening.

[Measurement method O evaluation method]

Note that the terminology used in the present invention and the evaluation method of characteristics will be explained.

(1) Isotactic Index: The percentage of the weight of the residue after extraction with boiling n-hebutane for 12 hours relative to the weight before extraction.

(2) Melt index Measured according to ASTM D 1238-57.

(3) Polymer density In a density gradient tube consisting of a water-alcohol mixed system.

Values measured at 25°C are expressed in units of I>Dg/cm.

(4) Longitudinal refractive index nMD and lateral refractive index of birefringent film”
The difference n from TD, rD-nMD, and the refractive index in the longitudinal and lateral directions of each layer of the laminated film were measured by the following methods.

Double beam transmission interference microscope (Carl Z%iss
(manufactured by Jen-na) was used. The film is immersed in an inert liquid having a refractive index nI different from that of the layer to be measured, and the difference in refractive index between the two is determined by the maximum movement of the interference stripe between 0.2 and 0.8 wavelengths. shall be given.

The value of nt was measured using an Atsube refractometer corrected for the sodium D line. The measurement films used were films cut into thin pieces of about 2 to 6 μm in the same direction as the measurement direction.

The film was placed in this liquid so that only one of the double beams passed through it, and its axis was placed against the stationary interference strip and perpendicular to the optical axis of the microscope.

Interference fringes were measured on this film using polarized light in the same direction as the measurement direction. The movement of the interference fringes is related to the refractive index and the thickness of the sample by the following equation.

d / D = (n n L ) t / λ where,
d is the distance between adjacent stripes n is the refractive index of the film in the measurement direction t is the optical path length at the point where d was measured (i.e. the thickness of the sample) λ is the wavelength of the light used for measurement For each interference fringe movement d, a set of shear and t values is obtained. Measurements were carried out in two types of liquids with different nl, and n was determined from two sets of n and t values.

(5) Hand-cutting property: Cut the sample at point 5- by twisting it with your fingers, and read the stress at that time. There is a sufficient correlation between this stress and the hand tearability, and the hand tearability is shown in Table 1.

Table 1 (6) Quantitative infrared absorption spectra of ethylene and propylene components, using (inner temperature) 8403 cm due to propylene and 731 cm-' due to ethylene.

It was determined by the standard curve method based on the absorbance of 720cI11.

The absorption of 720cIII is due to the ethylene component ■.
The absorption of 7310 is due to both ethylene components I and II. In addition, if the infrared absorption spectrum measured with 160-Q is used to quantify the total ethylene component, the influence of crystallinity will be eliminated and 720. , -' absorption is eliminated, which is preferable because measurement accuracy is improved.

(7) Haze Measured based on JIS-K 6714 method.

(8) Impact resistance 4 Charpy impact strength was measured as a characteristic value representing impact resistance.

Nyalpy impact strength is a value determined by a Charp7 impact tester, where the energy E (kg - cII +) required to cut the test piece is calculated by dividing the sample width (-)
It is shown as the value divided by.

The calculation method for E is based on the following formula.

E = WR (cos β - cos α) W is the hammer it (kg), R is the distance from the central axis of rotation of the 1 mm to the center of gravity (cm), α is the lifting angle of /1 mm, β is the specimen cutting This is the swing angle of the following No. 1 marker.

(9) Fix one end of the dispenser cuttable tape to a commercially available tape dispenser (Meki Kokuyo T-MI2) so that it is perpendicular to the static toothed metal fittings, and the other end is oriented toward the tape at an angle of 45″ from vertically downward. This is the stress (kg) at the time of cutting when pulled.

〔Example〕 The following is a description based on all nine embodiments of the present invention.

Example 1 pP (MI 8g 710 min at 230°C, II=97
%) and alicyclic petroleum resin (“Esco-
rez 5320″, manufactured by Esso Chemical) 25wt and polyethylene (melt O index at 190°C =
8゜density -0,945) 20wt, % mixed resin was extruded at a resin temperature of 250℃ using the T-die method, and then heated to 50℃.
Cool and solidify on a chilled cast drum kept at a constant temperature. The cast film was introduced into a hot air oven heated to 145°C and stretched 5.0 times in the longitudinal direction.

The resulting resin was extrusion laminated to obtain a two-layer laminated film.

The laminated film was placed in a tenter dy maintained at 158°C.
The surface was treated to achieve ne/aa.

The total thickness of the thus obtained laminated film was 35 μm, one layer (A) was 23 μm, and one layer (B) was 10 μm.

Table 2 shows the film properties.

One side of the film was coated with a dimethyl silicone mold release agent of 1 to 0.
The adhesive tape was coated to a thickness of 1 μm and dried, and then the adhesive tape was coated on the reverse side with polyacrylic acid ester as the main component. The properties of the resulting adhesive tape are shown in Table 2.

In addition, EPR with an ethylene content of 4 wt% is added to the laminated film.
An unstretched film (thickness: 15 cm) made of C was laminated on one side, this layer was folded in half along the stretching direction of the laminated film bag, and rolled at 130°C in three directions to form a 10 cm x 10 e+n bag. made.

At this time, 5gTh of calcium chloride was sealed inside the bag, and 40
'a. The sample was left in an atmosphere of 90% RH for 4 days, and the water vapor transmission rate was calculated from the weight change.

The characteristics of the bag are shown in Table 2. From the same table, the adhesive tape using the bond layer film of the present invention has IT4 impact resistance.

Dispenser cutting performance 1 Excellent manual cutting ability and
° It can be seen that the cutting direction is straight and the cut shape is beautiful.

Furthermore, the bag using the laminated film of the present invention has excellent moisture resistance, and when opened by tearing with one hand, it can be easily cut, and the tear direction is linear, indicating that the bag has excellent impact resistance.

Example 2 A laminated film was obtained in the same manner as in Example 1 except that the lateral stretching temperature was changed to 149°C. Adhesive tapes and bags were then made and evaluated in the same manner as in Example 1.9 Although the hand tearability and unsealability were slightly lower, they were excellent in dispenser cuttability, moisture resistance, and 1irl impact resistance.

Example 3 In Example 1, the raw material for layer (A) was an ethylene component of 6 wt.
% EpRc (MI 10g 710 min at 230°C) 6
Layer wt%, petroleum resin and pp each 2Qw as in Example 1
The process was carried out in the same manner except that t% was used.

Adhesive tapes and bags were made using this laminated film in the same manner as in Example 1, and although the one-handed tearability was slightly lower, they were excellent with no practical problems.

Example 4 In Example 1, the raw material for layer (A) had an ethylene content of 28w.
t% of E'P B C70wt% (MI of 250'O
9g/10min), EPRC with 4 wt% ethylene content
(MI 8g/10min at 230°C) 10wt and the same petroleum resin jz as in Example 1 was used at 20wt%, but otherwise it was carried out in exactly the same manner. Using this laminated film, adhesive tapes and bags were made in the same manner as in Example 1, and both were excellent.

Example 5 15 each of petroleum resin and polyethylene similar to Example 1
wt,%, 20wt%, pp (MI30g/230℃
10 minutes, ll97%) t-gin 5wt%, ethylene component 4
wt% EPRC (MI 30g71 at 230°0
The same procedure as in Example 1 was carried out except that a mixture of 30 wt.

Dispenser cutability, unsealability, and moisture resistance were good, but impact resistance was slightly deteriorated. However, there were no practical problems.

Comparative Example 1 When the same procedure was used as in Example 1 except that the Yokonobu oki temperature was changed to 140°C, the dispenser cutability,
The moisture resistance and impact resistance were good, but the one-handed tearability was poor.

Also, during film formation, film breakage occurred frequently.

Comparative Example 2 In Example 2, the mixing ratio of raw materials for layer 1 (A) was 20 wt% petroleum resin, 60 wt% polyethylene, P P 20
When the test was carried out in the same manner except for wt%, the one-hand cuttability was good, but the dispenser cuttability, moisture resistance, and impact resistance were poor.

Comparative Example 3 Same as Example 1, 3 wt% polyethylene, petroleum resin Sw
Unfortunately, EPR RC with 4 wt% ethylene content (230℃
layer (Ml 506/10 min) 92 wt% mixture (
When the same procedure as in Example 1 was carried out except for using the raw material of A), 9 had good hand cuttability and dispenser cuttability, but poor impact resistance and moisture resistance.

Comparative Example 4 20 wt% petroleum resin and pp (230 wt%) similar to Example 1
℃ MI 20g710min, ll97) 80wt,
% mixture was used as the raw material for layer (A), and the other conditions were exactly the same as in Example 1. 1. Hand cutability, dispenser cuttability, and moisture resistance were good, but impact resistance was poor. this.

Comparative Examples 5 to 6 The same procedure as Example ÷ was made (Comparative Example 6) except for the changes. From Table 2, it was found that in both Comparative Examples 5 and 6, the cut surface was not linear when cut by hand. I understand.

Comparative Example 7 (A) I (B) Both layers contained petroleum resin similar to that used in Example 2, and polyethylene at 1 petroleum resin 15 wt%.
.

When the same procedure as in Example No. was carried out except that polyethylene was added at a proportion of 15 wt%, the single-handed cutting property and the straightness of the cross section when cutting by hand were poor.

Comparative Example 8 In Example 1, the transverse stretching temperature was 168°C, and layer (A) I (B
) was carried out in exactly the same manner except that the thickness of the film was 32μ and 1μ, but the film broke frequently and a laminated film could not be obtained.

〔Effect of the invention〕

(1) The polypropylene laminated film of the present invention.

Biaxially stretched polyolefin containing a specific proportion of petroleum resin, ethylene and propylene components.

Furthermore, by specifying the amounts of propylene components in both layers, a film with excellent hand tearability, LTI impact resistance, and moisture resistance can be obtained, and when used as an adhesive tape, the following effects can be obtained.

(a) Dispenser cutability and hand cutability.

It has excellent impact resistance and can be easily cut.

(b) The cutting direction is straight and beautiful when torn by hand.

Furthermore, when the heat seal layer is used as a packaging bag, the following effects can be obtained.

(b) It is easy to open by hand and the opening opening is straight so that the contents do not spill out.

(b) Excellent moisture resistance, extending shelf life.

(c) Excellent impact resistance and difficult to tear.

(2) Furthermore, an excellent method for producing a laminated film as described above could be provided.

Claims (2)

[Claims] (1) Petroleum resin 10-30wt% and polyolefin 70
The polyolefin is composed of a composition in which the ethylene component and the propylene component are 0.5 to 50 wt% and 20 to 89.5 wt%, respectively, based on the sum of the weight of the petroleum resin and the weight of the polyolefin. It has an axially stretched layer (A) and a laterally uniaxially stretched layer (B) made of a composition mainly consisting of 0 to 20 wt% of petroleum resin and 80 to 100 wt% of polyolefin, and
The ratio (wt%) of the propylene component in layer (B) is 5 wt% or more than the ratio (wt%) of the propylene component in layer (A), and the birefringence of layer (A) and layer (B) is The layer (B
) and the birefringence ratio (Δn_B/Δn_A) of layer (A) is 2
A polyolefin laminate film having a molecular weight of ~35. (2) Petroleum resin 10-30wt% and polyolefin 70
The polyolefin is composed of a composition in which the ethylene component and the propylene component are 0.5 to 50 wt% and 20 to 89.5 wt%, respectively, based on the sum of the weight of the petroleum resin and the weight of the polyolefin. The stretched sheet is stretched 4 to 8 times in the longitudinal direction at 100 to 150°C to form a uniaxially stretched film, and the film is coated with 0 to 2 petroleum resin.
0 wt% and 80 to 100 wt% of polyolefin are laminated, and the laminate is heated to 14% by weight.
A method for producing a laminated film comprising stretching 8 to 12 times in the transverse direction at 5 to 165°C.