JPH05162268A - Laminated metallized plastic film - Google Patents

Abstract

PURPOSE:To enhance gas barrier properties and to automate filling packing, in a composite film composed of three layers laminated by a co-extrusion method, by forming three layers by compounding a linear low density ethylenic polymer and a high density ethylenic polymer with a crystalline propylene polymer. CONSTITUTION:A composite film is obtained by laminating three layers (A), (B), (C) by a co-extrusion method. In this case, the (A) layer is formed by compounding 1-30 pts.wt. of linear low density ethylenic polymer specified in density and 1-30 pts.wt. of a high density ethylenic polymer specified in density with 100 pts.wt. of a crystalline propylene polymer. The (B) layer is a crystalline propylene polymer and formed from a composition specified in stereoregularity. The (C) layer is formed by compounding 1-15 pts.wt. of an ethylene/butene copolymer specified in the concn. of butene and 1-20 pts.wt. of linear low density ethylenic polymer specified in density with 100 pts.wt. of a crystalline propylene copolymer specified in its crystal m.p.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a composite film obtained by a three-layer coextrusion method, and more particularly to a laminated metal vapor-deposited plastic film.

[0002]

2. Description of the Related Art A polypropylene-based non-stretched metal-deposited film has been applied to a biaxially-stretched polypropylene film or polyester film mainly for snack confectionery packaging by taking advantage of its characteristics of surface gloss and low temperature heat sealing suitability. Widely used as a laminated film for food packaging.

However, in the single-layer unstretched vapor-deposited film, the portion heat-sealed by the bag-making process is whitened and a crack phenomenon occurs in the vapor-deposited film due to recrystallization of the vapor-deposited surface, resulting in a decrease in adhesive strength of the vapor-deposited film. There is a problem that the gas barrier property is lowered. To improve this, the present researchers
As proposed in No. 13, a method of making a difference in melting point between the resin film on the vapor-deposited surface and the resin film used on the heat-sealed surface is used. The reduction in barrier properties is improved.

[0004] Recent vapor-deposited films require wider width and longer winding to improve profitability and production efficiency, and the film used for vapor deposition has improved blocking resistance and rigidity capable of withstanding long winding. Is needed. Furthermore, in the process of making a laminated film in a bag, due to the change in the packaging form due to the sharpness of the folding angle in the high-speed bag making process and the small bag making process, the equipment stress on the packaging material becomes stronger, and the stress becomes higher. Fine cracks occur in the vapor-deposited film, and the problem of reduced gas barrier properties is highlighted, and conventional single-layer vapor-deposited propylene film and laminated metal vapor-deposited film proposed by the present inventors cannot improve these. There are problems such as.

Further, the bag-making speed of the automatic filling and packaging machine can be increased, and the heat-sealing strength can be maintained (hot tack) which can withstand the load of the inner package immediately after the heat-sealing and the adhesion in a short heat-sealing time. The demand for the development of a metal-deposited film that is capable of high pressure) has become stronger, the gas barrier property does not deteriorate due to the increase in mechanical stress, and the development of a film that has a low temperature heat seal property and hot tack property that enables high-speed bag making is urgent. The current situation is that it will be lost.

[0006]

DISCLOSURE OF THE INVENTION The object of the present invention consists of a specific composition (A) in order to solve the above problems.
Improving the vapor deposition strength of the layer and using a layer of a highly crystalline propylene polymer having a stereoregularity (P) of 0.970 or more for the core layer (B) at a ratio of 20% or more with respect to the total thickness. By doing so, it is possible to provide a coextrusion laminated metal vapor-deposited plastic film having excellent dimensional stability that can accommodate long winding and gas barrier properties after bag making, and it is possible to provide a propylene copolymer having a low crystalline melting point. A co-extruded laminated metal that can be used for high-speed filling and packaging by having an (C) layer formed by mixing an ethylene-butene copolymer, a linear low-density ethylene polymer, and a specific calcium-sodium-alumino-silicate The purpose is to provide a vapor-deposited plastic film.

[0007]

The present invention provides a composite film in which layers (A) and (C) are laminated on both sides of a layer (B) by a three-layer coextrusion method, and the layer (A) is crystalline. 1 to 30 parts by weight of linear low-density ethylene polymer having a density of 0.930 g / cm ³ or less and a density of 0.950 g per 100 parts by weight of a water-soluble propylene polymer.
The layer (B), which is composed of a composition containing 1 to 10 parts by weight of a high-density ethylene polymer having a density of 1 / cm ³ or more, is a crystalline propylene polymer and has a stereoregularity (P) of 0.970. The layer (C) composed of the above composition has a crystal melting point (T
m) 140 ° C or less, 100 parts by weight of crystalline propylene-based copolymer, 1 to 15 parts by weight of ethylene-butene copolymer having a butene concentration of 10 to 40 mol% and linear low density of 0.930 or less. The layer is composed of a composition containing 1 to 20 parts by weight of an ethylene polymer.

In the coextrusion laminated metal vapor-deposited plastic film of the present invention, the surface layer is a layer of a plastic resin having an excellent metal vapor deposition strength, and the sealant layer is a layer made of a specific composition and having an excellent hot tack property and capable of high-speed filling. Is a coextrusion laminated film having The crystalline propylene-based polymer in the present invention means, for example, a propylene homopolymer, propylene and other α in the presence of a Ziegler-Natta type catalyst.
A block copolymer with an olefin (ethylene, butene, 4-methylpentene, octene, etc.), an unsaturated carboxylic acid or its derivative (acrylic acid, maleic anhydride, etc.), or a mixture thereof.

Here, the stereoregularity (P) of the propylene-based polymer indicates the isotactic pendat fraction of the boiling n-heptane-insoluble matter of the crystalline propylene-based polymer (A. Zambel et al., Macromolecules, 6, 925 (1973)). That is, it is the isotactic fraction in pendad units in the crystalline propylene polymer molecular chain measured using ¹³ C-NMR (nuclear magnetic resonance spectroscopy).

The stereoregularity (P) of the crystalline propylene polymer used for the core layer of the layer (B) is 0.970 or more,
A highly crystalline propylene polymer having a boiling n-heptane insoluble content of 95% or more is particularly desirable, and when the stereoregularity (P) is lower than 0.970, the film of the core portion of the long winding may block or the biaxial The gas barrier of the bag produced in the step of forming a laminated film with a stretched polypropylene film or a polyester film or the vertical pillow type automatic filling and packaging step is significantly reduced, which is not preferable. A similar problem occurs when the insoluble content of boiling n-heptane is lower than 95%.

Further, the thickness of the layer (B) is preferably 20% or more of the total thickness of the laminated film. 20%
When it becomes lower, as in the case where the stereoregularity (P) is lower than 0.970, wrinkles are generated in the core of the long winding film, and even if a product is made with a winding length of about 8,000 to 12,000 m, The variation in gas barrier property before and after the bag making process after lamination is large, and the gas barrier property of the vapor deposition film is substantially reduced.

The melt flow rate (MFR) of the crystalline propylene polymer used in the present invention (JIS K 7210-19
Test condition 14 (measured at 230 ° C., 2.16 kgf) based on 76) is not particularly limited as long as a laminated film having a uniform thickness can be exhibited by the T-die chill roll method of the coextrusion laminating method, but preferably 1 to It is in the range of 30 g / 10 min, particularly preferably in the range of 3 to 20 g / 10 min.

The laminated metal vapor-deposited plastic film of the present invention is a film in which (A) / (B) / (C) are laminated in this order, and a metal is vapor-deposited on the surface of the (A) layer. ) The layer comprises 1 to 30 parts by weight of a linear low-density ethylene polymer having a density of 0.930 g / cm ³ or less and 100 to 100 parts by weight of a crystalline propylene polymer, and a high-density ethylene system having a density of 0.950 g / cm ³ or more. The layer is composed of a composition containing 1 to 10 parts by weight of the polymer, but when a linear low density ethylene polymer having a density of more than 0.930 g / cm ³ is used, the effect of improving the vapor deposition strength is In the case of bag-making products, the gas barrier property is lowered due to the stress of the packaging machine, which is not preferable. When 1 to 30 parts by weight of a linear low-density ethylene polymer having a density of 0.930 g / cm ³ or less is blended, the vapor deposition strength itself is improved, but the gas barrier property of the bag-making product is deteriorated due to the decrease in rigidity. , Density 0.950g / cm ³
By blending 1 to 10 parts by weight of the above high density ethylene polymer, a vapor deposition film having a good gas barrier property after bag making can be obtained. A high-density ethylene-based polymer with a density of less than 0.950 g / cm ³ has no effect of preventing the gas barrier property of the bag-making product from decreasing, and a high-density ethylene-based polymer with a density of 0.950 g / cm ³ or more is used. It is not preferable to add more than parts by weight because a metal-deposited film showing a beautiful luster cannot be obtained.

Further, when it is used for a film for lamination, metal vapor deposition is applied to the surface of the (A) layer, and the (C) layer is used as a sealant layer for bag making. In this case, (A)
In the case of a two-layer laminated film including only the layer and the layer (B), the metal barrier film is whitened and the gas barrier property is deteriorated due to cracks in the temperature range of the heat-sealing capable of bag-making, and the film after the high-speed bag-making process of the present invention is manufactured. It is not preferable because it does not meet the purpose of keeping the bag product made of gas barrier. The crystalline propylene-based polymer used in the (C) layer is a propylene-ethylene copolymer having a crystal melting point (Tm) of 140 ° C. or less, a propylene-ethylene-butene copolymer, and a copolymerization weight of propylene and α-olefin. A combined product is preferable, and a crystalline propylene copolymer having a crystal melting point higher than 140 ° C. is used to obtain a bag-manufactured product in which the gas barrier property is prevented from lowering, as in the case of the two-layer laminated product (A) / (B). It is not preferable because it cannot be generated.

The (C) layer in the present invention has a crystalline melting point (T
m) 140 ° C or less, 100 parts by weight of crystalline propylene-based copolymer, 1 to 15 parts by weight of ethylene-butene copolymer having a butene concentration of 10 to 40 mol% and linear low density of 0.930 or less When the butene concentration is lower than 10 mol%, it is a layer composed of a composition containing 1 to 20 parts by weight of an ethylene-based polymer, and there is no effect of improving low-temperature heat-sealability, butene concentration is higher than 40 mol%. If it is large, it does not show crystallinity, and the heat-sealing layer is blocked from the metal vapor deposition surface in the laminated metal vapor deposition film, resulting in partial peeling of the metal vapor deposition film and not being a metal vapor deposition film exhibiting stable gas barrier properties, which is not preferable. .. Even if the ethylene-butene copolymer is blended in an amount of more than 15 parts by weight, the gas barrier property is deteriorated due to the partial peeling of the metal vapor deposition film. A laminated film using a composition containing 1 to 15 parts by weight of an ethylene-butene copolymer as the sealant layer (C) layer exhibits good low-temperature heat-sealing property, but the content of the content part immediately after heat-sealing is The hot tack, which is the holding power, is inferior, which is not preferable. The sufficient sealant layer for the purpose of the present invention is to secure low-temperature heat-sealing property while retaining hot tack property, and as a result of earnest study, a linear low-density ethylene polymer having a density of 0.930 g / cm ³ or less is further obtained. It was found that the compounding amount of 1 to 20 parts by weight results in a sealant layer having hot tack property. If the density of the linear low-density ethylene polymer is larger than 0.930 g / cm ^3, there is no improvement effect on hot tack, and if the linear low-density ethylene polymer is blended in an amount of more than 20 parts by weight, the sealant layer A peeling phenomenon occurs in the inside, and the heat seal strength decreases, which is not preferable.

It is also possible to prepare a non-stretched plastic film and vapor-deposit metal by using the composition for forming the layer (C) of the present invention, which retains the low temperature heat-sealing property and the hot tack property, alone. Although the film is a good vapor deposition film that retains hot tack properties and also exhibits low temperature heat sealing properties, the gas barrier property after bag forming of the laminated film deteriorates.

The calcium-sodium-alumino-silicate fine powder blended in the composition used for the layer (C) is amorphous by subjecting a natural or synthetic zeolite to an ion-exchange treatment with a divalent metal and then heat treatment. Obtained through qualification. Unlike zeolite, amorphized fine powder is completely amorphous by X-ray diffractometry and does not show a crystalline structure, but the primary particles of the composition maintain a spherical shape from a cube of almost uniform size. The main component is silicon dioxide (SiO ₂ ) and aluminum oxide (Al ₂ O ₃ ), and contains sodium oxide (Na ₂ O) and calcium oxide (CaO).

In the present invention, calcium, sodium,
The alumino-silicate fine powder preferably has a chemical composition within the following composition range. SiO _2: 53 ~ 56 wt% Al ₂ O _3: 25 ~28 wt% CaO: 8 to 11 wt% Na ₂ O: 4 to 8% by weight ignition loss: 4 wt% or less It should be noted that the chemical composition of the present invention Of the analyzes, the loss on ignition (Ig-LOSS), silicon dioxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), and sodium oxide (Na ₂ O) are described in JI.
Measured according to SM 8852. Atomic absorption method was used for CaO.

The average particle size was obtained from the cumulative distribution chart by the Coulter method. The average particle size of the calcium, sodium, alumino, silicate fine powder used in the present invention is preferably in the range of 1.0 to 6.0 μ, 1.0
If it is smaller than μ, there is no blocking prevention effect, and tear occurs when the film is rewound in the metal vapor deposition step. When the average particle size is larger than 6.0 μ, blocking does not occur, but when large-sized agglomerates due to the fine powder occur, perforation occurs in the film, which is not preferable.

A composition prepared by adding 0.01 to 1.00 parts by weight of calcium-sodium-alumino-silicate used in the present invention is used on the surface, but when it exceeds 1.00 parts by weight,
In addition to the occurrence of large-scale aggregates due to poor dispersion, the sealant layer surface of the vapor-deposited film wound in a roll and the vapor-deposited surface are rubbed with each other, and the vapor-deposited surface is likely to be scratched. It is not preferable because the barrier property is lowered.

Calcium-sodium-alumino-silicate preferably has a sphericity (Fx) in the range of 0.85 or more. Here, the sphericity (Fx) indicates a coefficient represented by the following formula, and in the case of a sphere, the coefficient Fx is 1.0. (Fx) ² = R ₁ × R ₂ / (R ₁ ) ² (where Fx is a coefficient of sphericity of fine powder, and R ₁ ,
R ₂ shows the circumscribed radius (R ₁ ) and the inscribed radius (R ₂ ) of the grain photograph contour of a single grain by enlarging and photographing the fine powder with an electron microscope. ) A true sphere having a sphericity coefficient Fx of 1.0, for example, a thermosetting true spherical silicone resin, improves the slipperiness of the film and lowers the coefficient of kinetic friction, but has an effect of preventing blocking between films and blocking of a vapor deposited film. However, the formation of wrinkles on the core of the vapor-deposited film cannot be prevented, but the calcium-sodium-alumino-silicate used in the present invention exhibits a good antiblocking effect even when Fx is 1.0. When the coefficient of sphericity Fx is lower than 0.85, there is no blocking effect and it is not preferable.

The coextrusion laminated metal evaporated plastic film of the present invention is laminated in the order of (A) / (B) / (C),
It is a film in which metal is vapor-deposited on the surface of the (A) layer,
In the composition forming the layers (A) and (C), the stereoregularity (P _A ) and (P _C ) of each crystalline propylene-based polymer satisfy the formulas (1) and (2). It is a crystalline propylene-based polymer having stereoregularity, and (P) ≧ (P _A )> (P _C ) (1) b · (P) + a · (P _A ) + c · (P _C )> 0.87 ( 2) Here, a, b, and c are (A) layer, (B) layer,
The thickness ratio of each of the layers (C) to the total thickness of the film is shown (however, a, b, and c are not 0).

When (P _A ) is less than (P _C ), the vapor-deposited surface of the heat-sealed portion is whitened and the gas barrier property is lowered due to the crack phenomenon of the vapor-deposited film, which is not suitable for the purpose of the present invention. Absent. When the sum of the product of the thickness ratio of each layer and the stereoregularity is 0.87 or less, the gas barrier property is lowered in the packaging bag after the automatic filling and packaging, and the object of the present invention cannot be achieved. Further, by using the laminated metal vapor-deposited plastic film of the present invention, after washing the metal vapor-deposited film (in the case of aluminum, washing with an alkaline aqueous solution), the stereoregularity of the film itself is measured to satisfy the formula (2) of the present invention. You can see that it is a film that does.

In the composition used for the coextrusion laminated metal vapor deposition film of the present invention, an antioxidant (phosphorus antioxidant, phenolic antioxidant, etc.) and a neutralizer which are usually added to a propylene polymer. (Zeolite, hydrotalcite, etc.), anti-blocking agent (silica, spherical spherical thermosetting resin, aluminum silicate, etc.) can be used within the range not impairing the object of the present invention.

The coextrusion laminated metal vapor deposition film of the present invention is
(A) / (B) / (C) are laminated in this order, and a metal vapor-deposited plastic film in which metal is vapor-deposited on the surface of the (A) layer,
The composition of each layer, a specific mixture in a predetermined mixing ratio of a normal stirring mixer, for example, Henschel mixer (trade name),
It can be obtained by stirring and mixing with a super mixer or a ribbon blender, and can also be obtained as pellets by melting and kneading the mixture with an ordinary single-screw extruder, twin-screw extruder, roll, etc. to form pellets. it can. Further, calcium, sodium, alumino, and silicate are individually blended in a crystalline propylene-based polymer and pelletized, and the individual pellets of each polymer are mixed with the crystalline propylene-based polymer pellets in a predetermined mixing ratio. It can also be obtained by pellet blending with a blender. (A) of the present invention,
The method for laminating the coextrusion laminated film containing the layers (B) and (C) is melt extrusion using three or more extruders, and a known state such as a coextrusion multilayer die method or a feed block method is used. The T-die / chill-roll method of rapidly cooling to 70 ° C. or lower with a cooling roll after laminating is preferable for producing a long wound film having a uniform thickness.

Metal is vapor-deposited on the (A) layer side of the coextruded laminated film thus obtained, but a surface treatment may be applied to the (A) layer side in order to improve the adhesiveness of the vapor-deposited film. desirable. This surface treatment method is corona, discharge treatment,
Although flame treatment, acid treatment, or the like may be used, corona discharge treatment is most preferable because the laminated film can be continuously treated, can be easily performed before winding at the time of film formation, and the degree of treatment can be arbitrarily adjusted. As for the surface treatment, an effect promoting method such as corona discharge or plasma discharge may be used under heating or in an atmosphere of inert gas.

Next, the method of depositing a metal on the (A) layer surface of this coextruded laminated film is a vacuum vapor deposition method, that is, the atmospheric pressure in the vacuum vapor deposition apparatus is reduced to about 10 ^-3 to 10 ^-6 Torr. Then, the target metal lumps such as aluminum, nickel, gold, and silver are dissolved and evaporated by an induction heating method such as ultrasonic waves,
A method is generally used in which vaporized molecules are continuously vapor-deposited on the surface of a film and wound up, but other known methods such as sputtering vapor deposition and ion plating method are also possible. In addition, as the metal to be deposited, aluminum, gold,
Silver, copper, nickel, chromium, germanium, silica and the like can be mentioned, but aluminum which is intended for food packaging is particularly preferable, and the laminated metal vapor-deposited plastic film of the present invention has a particularly excellent effect on a film obtained by vapor-depositing this aluminum. Exert.

The thickness of metal vapor deposition is preferably about 100 to several hundred angstroms in terms of adhesion, durability and economy. The coextrusion laminated metal vapor deposition film of the present invention thus obtained is a metal vapor deposition film having high vapor deposition strength and excellent gas barrier property by itself, which is a useful invention and, after anchor coating on the vapor deposition surface, It is laminated with various kinds of films such as stretched polypropylene film, polyester (PET), nylon and Eval and used for packaging bags for oily snacks such as potato chips and automatic filling packaging bags. In particular, the laminated metal vapor deposition film of the present invention,
High-speed bag making is possible in the bag making and automatic filling and packaging processes,
Having an excellent hot tack property, oxygen, gas barrier properties such as nitrogen do not change even after becoming a bag-making product, and it is possible to present a packaging bag excellent in long-term storage of packaged food, and the object of the present invention is to Achieved.

The measurement and evaluation of characteristics in the present invention were carried out by the following methods and standards. (1) Melt flow rate (MFR): JIS K 7210-1976
It measured based on the test conditions 14 (230 degreeC-2.16kgf). (Unit: g / 10 min). (2) Sphericity (Fx): (Fx) ² = R ₁ × R ₂ / (R ₁ ) ² scanning type (where Fx is a coefficient of sphericity of fine powder, R ₁ ,
R ₂ is a magnified photograph of the fine powder taken by an electron microscope, and shows the circumscribed radius (R ₁ ) and the inscribed radius (R ₂ ) of the particle photograph contour of a single particle.

(3) Vapor deposition strength of vapor deposition film: The vapor deposition film side of the vapor deposition film and the Surlyn film (ionomer manufactured by Tama Poly Co., Ltd.) are sealed at a temperature of 120 ° C. and a sealing pressure of 2.0 kg / cm.
^2. Sealing was performed with a width of 10 mm × 15 mm under the condition that the sealing time was 1.0 second, and the peeling strength at 90 ° C. was measured by a tensile tester manufactured by Toyo Seiki Co., Ltd. at a tensile speed of 300 m / min. (Unit: g / 15
mm).

(4) Crystal melting point (Tm): A scanning differential calorimeter (abbreviation: DSC) was used to set a 10 mg sample, and the temperature was raised from room temperature at a heating rate of 20 ° C./min to crystallize. The endothermic curve associated with melting is measured, and the peak temperature of the endothermic curve associated with melting is defined as Tm (unit: ° C).

(5) Stereoregularity (P): The boiling n-heptane insoluble matter of the crystalline propylene-based polymer was analyzed 27,000 times by using an FT-NMR (Fourier transform nuclear magnetic resonance spectrometer) at 270 MHz. Through integrated measurement, the signal detection limit was improved to an isotactic pendant fraction of 0.001. The boiling n-heptane insoluble matter of the crystalline propylene-based polymer was 5 g of the crystalline propylene-based polymer in 500 ml.
Was completely dissolved in boiling xylene, and the mixture was poured into 5 liters of methanol for precipitation, and the precipitate was recovered and dried, and the extract residue was subjected to Soxhlet extraction with boiling n-heptane for 6 hours.

(6) Gas barrier property: using an unstretched film obtained by vapor-depositing 300 Å of aluminum,
A urethane adhesive was used for a 25 μm-thick film of biaxially oriented polypropylene, dry lamination was performed, and then drying was performed to form a laminated film. High speed pillow automatic filling machine (FA-350 E: manufactured by Totani Giken Kogyo Co., Ltd.) was used to perform high-speed bag making of 120 bags per minute, and the oxygen permeability of the laminated film before bag making The oxygen permeability after the bag is measured by Toyo Seiki Co., Ltd.
It was measured with "MC3".

The rate of change of oxygen permeability before and after bag making of each laminate film is shown by the following formula, and the smaller the rate of change, the better the gas barrier property. ΔGTR = GTR ₂ / GTR ₁ ΔGTR is the rate of change in oxygen permeability, GTR ₁ is the oxygen permeability before bag making, and GTR ₂ is the oxygen permeability after bag making.

(7) Heat-sealing property: Sealing temperature (° C) at which a sealing strength of 500 g / 15 mm is obtained Sealing conditions: Toyo Seiki's heat-gradient seal temperature measuring device, seal pressure 1 kg / cm ² · G 1 second Tensile test: Specimen width 15 mm, pulling speed 300 m / min.

(8) Hot tack property: Peeling length (mm) at sealing temperatures of 130 ° C and 140 ° C Sealing conditions: Seal bar type seal temperature measuring instrument manufactured by Toyo Seiki, sealing pressure 2 kg / cm ^{2 for} 1 second, 90 g load Measuring method: Set two specimens with the sealant surface of the laminated film of width 30mm and length 1m so that the longitudinal direction of the seal bar of width 10mm and length 300mm and the flow direction of the film are parallel, Immediately after heat-sealing under predetermined heat-sealing conditions, a load of 45 g (total 90 g) is applied to each sample piece in parallel to the longitudinal direction of the seal bar (natural drop). At this time, a baffle whose position is fixed is inserted between the two sample pieces, and the seal portions of the two sample pieces are separated by a load of 45 g immediately after the sealing. This peel length (up to 300
mm) to be used as a measure of hot tackiness. The hot tack property is better as the peeling length is shorter.

[0037]

The laminated metal vapor-deposited plastic film of the present invention has an excellent gas barrier property, and has a stable gas barrier property even after bag-making with a dry laminated film with a stretched polypropylene film or a polyester film. It is possible to prepare a packaging bag that has long-term storage in food packaging.

Furthermore, in filling packaging at high filling speed,
The high-speed bag-making process demanded by the market and automatic filling and packaging without bag breakage or bottom out have been made possible, and the efficiency of filling and packaging has been significantly improved. It can be created and can be applied to a wide range of purposes.

[0039]

EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited thereto. Examples 1 to 16 and Comparative Examples 1 to 16 Compositions having the characteristics of each company shown in Tables 1 to 5 were used, and 3 types 3
Layer co-extruded laminated plastic film is made, then the plastic film is aluminum-deposited under a vacuum of 1 × 10 ^-5 Torr using a roll-up type vacuum deposition device and rolled up. An angstrom single-sided vapor deposition film was obtained. Further, the vapor-deposited surface of the obtained single-sided vapor-deposited film and the corona-treated surface of a 25μ biaxially oriented polypropylene film were dry-laminated with a urethane adhesive, and the resulting laminated film was made into a bag at a bag-making speed of 180 bags / 1 minute. did.

Table 6 shows the characteristic values of the vapor-deposited film and laminate film obtained in each step, and the bag-made product. As is clear from Table 6, Examples 1 to 16 having the constitution of the present invention are excellent in all the characteristics, and particularly the stereoregularity (P) of the crystalline propylene polymer for the (B) layer is 0.920. Compared with the vapor-deposited film of Comparative Example 1 using a polymer, the gas barrier property, which is a change in oxygen permeability before and after bag making, was very small and good, and the vapor-deposited film and the laminated film had low-temperature heat-sealing properties. It can be seen that the film has excellent performance in both hot tack properties. On the other hand, the vapor-deposited films and laminated films of Comparative Examples 1 to 16 shown in Table 7 are inferior in any of the properties as compared with the respective examples of the examples, which is not preferable.

Examples 17 and 18 In Example 11, 100 parts by weight of the composition of layer (C) was used, and the average particle size was 3 with respect to 100 parts by weight of the crystalline propylene homopolymer.
μ and 6 μ of calcium, sodium, alumino, and silicate were mixed in an amount of 2 parts by weight and 10 parts by weight of a pelletized composition was prepared to prepare a laminated plastic film of 3 layers and 3 layers in the same manner as in Example 11. OP after metal deposition
After laminating with a P film, a bag was prepared with a bag making device.

The obtained metal vapor-deposited plastic film was excellent in all the properties aimed at by the present invention, and in particular, there was no blocking of the sealant layer and the metal vapor-deposited surface, and the gas barrier property of the obtained vapor deposition film was further improved.

[0043]

[Table 1]

[0044]

[Table 2]

[0045]

[Table 3]

[0046]

[Table 4]

[0047]

[Table 5]

[0048]

[Table 6]

[0049]

[Table 7]

Claims (5)

[Claims] 1. A composite film in which layers (A) and (C) are laminated on both sides of a layer (B) by a three-layer coextrusion method, wherein the layer (A) comprises 100 parts by weight of a crystalline propylene polymer. ,
Density from 0.930 g / cm ³ or less linear low density ethylene polymer 1-30 parts by weight and density 0.950 g / cm ³ or more high-density ethylene polymer 1-10 parts by weight composition prepared by blending Layer, the layer (B) is a crystalline propylene-based polymer, and the layer is composed of a composition having stereoregularity (P) of 0.970 or more, and the layer (C) has a crystal melting point (Tm) of 140 ° C. or less. With 100 parts by weight of the crystalline propylene copolymer, the butene concentration is 10 to 40
Mol% ethylene-butene copolymer 1 to 15 parts by weight and linear low-density ethylene polymer 1 to a density of 0.930 or less 1 to
A coextrusion laminated metal vapor-deposited plastic film, which is a layer formed of a composition containing 20 parts by weight. 2. A laminate of (A) / (B) / (C), wherein the thickness of the (B) layer is 20% or more of the total thickness of the film, and a metal is vapor-deposited on the (A) layer surface. Item 1. A coextrusion laminated metal vapor-deposited plastic film according to item 1. Wherein stereoregularity of the crystalline propylene polymer used in the (A) layer (P _A) and (C) a crystalline propylene copolymer used in layer polymer stereoregularity (P _C) is (B ) The coextrusion laminated metal vapor-deposited plastic film having the relationship of the following formula with the stereoregularity (P) formula of the propylene polymer used for the layer. (P) ≧ (P _A )> (P _C ) (1) b · (P) + a · (P _A ) + c · (P _C )> 0.87 (2) where a, b, and c are in order ( A) layer, (B) layer,
The thickness ratio of each layer (C) to the total thickness of the film is shown (however, a, b, and c are not 0). 4. The sphericity of 100 parts by weight of the composition of layer (C)
The laminated metal vapor deposition film according to claim 1, wherein 0.01 to 1.00 part by weight of calcium-sodium-alumino-silicate having an average particle size of 1 to 6 µm is 0.85 or more. 5. The coextrusion laminated metal vapor-deposited plastic film according to claim 1, which is produced by a T-die / chill-roll cooling method.