KR20180118042A - Heat-shrinkable laminate film and bag - Google Patents

Abstract

The present invention provides a heat-shrinkable laminate film having slipperiness and transparency, which are difficult to be compatible with each other, and a pocket made thereof. The heat-shrinkable laminate film has an outer surface layer (A) on at least one of the outermost surface. The outer surface layer (A) has an average particle diameter of 1.2 to 10.0 times with respect to the thickness of the outer surface layer (A).

Description

Heat-shrinkable laminated film and bag (HEAT-SHRINKABLE LAMINATE FILM AND BAG)

The present invention relates to a laminated film in which a plurality of layers are laminated, and relates to a heat-shrinkable film which is shrunk by heating. More particularly, the present invention relates to a heat- A heat-shrinkable laminated film having excellent slidability and transparency capable of efficient packaging treatment, and a bag using the same.

Generally, heat-shrinkable laminated films are used for packaging of foods, medical devices, machine parts, and the like. The heat-shrinkable laminated film is given a function according to its use depending on each layer having various properties.

When the heat-shrinkable film is used for packaging, barrier properties, transparency, and heat sealability are important in addition to heat shrinkability.

In addition, many of such heat-shrinkable films require a film secondary processing step such as a bagging operation. The properties required here are ease of feeding the film raw material, difficulty in attaching the film to the heat seal bar, and ease of slippage between film and equipment. In addition, in the bag that has been evacuated, it is required to facilitate the taking-out of the pockets of stacked layers, that is, the ease of slippage between films and films. Such characteristics are collectively referred to as handling properties.

As described in Patent Documents 1 and 2, as a method of imparting the above-described handling property to a heat-shrinkable film, it is general to attach (powder) the starch powder to the surface thereof.

However, since the starch powder is white, transparency and gloss of the film are impaired. The starch powder adhering to the surface is not suitable for packaging machine parts and the like where transparency is strongly required because the transparency is not improved unless it is removed by water or the like.

Powdered powder tends to fall off from the film, and is scattered to the periphery when the bag is used during film production and secondary processing, so that contamination of the surrounding environment or inhalation into humans is a concern. In addition, when the heat seal film is discharged into the bag, starch powder is deposited on the seal bar to deteriorate heat conduction and cause a seal failure.

Patent Document 3 discloses a heat-shrinkable film which is excellent in slipperiness, transparency, and the like, which is not a heat-shrinkable film but contains spherical silica, which is the smaller one of the average particle diameter of 0.5 占 퐉 or more, Tearable laminated film is disclosed.

In this document, when particles remarkably larger than the thickness of the outer layer are used, it is preferable that the upper limit of the average particle size of the particles be 2 times or less the thickness of the outer layer or 4 μm or less .

As described above, a heat-shrinkable film having both handleability such as slipperiness, transparency and gloss was not obtained.

Japanese Patent Publication No. 4848020 Japanese Laid-Open Patent Publication No. 2016-147373 Japanese Patent Publication No. 5061522

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a heat-shrinkable laminated film having slipperiness and transparency, both of which are difficult to be compatible with each other, and a pocket made of the laminated film.

As a result of intensive studies to solve the above problems, the inventors of the present invention have found that by containing large particles in the outer surface layer (A), a heat-shrinkable film having high slidability (handling property) I found out.

Generally, it is known to form irregularities on the surface in order to improve slipperiness. However, when large particles such as those giving unevenness to the outer surface layer of the film are contained, transparency and gloss are impaired, Causing problems such as low heat sealability and contamination. Therefore, the incorporation of large particles in the outer surface layer has not been attained in an article in which at least the appearance (transparency, glossiness) is emphasized and the particles are expected to fall off as viewed from the handling method.

However, when heat-shrinking the heat-shrinkable laminated film, the present inventors have found that when the thickness of each layer constituting the film is increased accompanied by the presence of particles in the outer surface layer, the film is deposited on the outer surface layer, It is required that transparency and gloss of the film after heat shrinkage is lowered or that the heat shrinkable laminated film does not fall off from the outer surface layer even when large particles are contained in the outer surface layer, It is also found that the risk of falling off of the particles is increased and that the scene requiring slippery after heat shrinkage actually used is found before the heat shrinking process such as a umbrella process. On the basis of such knowledge, if the outer surface layer (A) contains particles having a specific average particle diameter, slip property is imparted to the film before heat shrinkage, transparency and gloss are lowered after thermal shrinkage, A heat-shrinkable laminated film which does not contain the heat-shrinkable laminated film. The present invention has been completed based on this finding.

That is, the present invention is as follows.

[1] A heat-shrinkable laminated film having an outer surface layer (A) on at least one of its outermost surfaces,

Wherein the outer surface layer (A) contains particles having an average particle diameter of 1.2 to 10.0 times the thickness of the outer surface layer (A).

[2] The heat-shrinkable laminated film according to [1], wherein the outer surface layer (A) has a thickness of 0.1 to 3.0 μm.

[3] The heat-shrinkable laminate according to [1] or [2], wherein the outer surface layer (A) comprises a resin or a resin composition and the particles and the difference in refractive index between the resin or the resin composition and the particle is 0.05 or less. film.

[4] The heat-shrinkable laminated film according to any one of [1] to [3], wherein the heat shrinkage ratio at 75 ° C in the flow direction and the transverse direction is not less than 10% and not more than 65%.

[5] A pressure-sensitive adhesive sheet, which further comprises an adhesive layer (B), a barrier layer (C) and an inner surface layer (D)

The heat-shrinkable laminated film according to any one of [1] to [4], wherein the outer surface layer (A), the adhesive layer (B), the barrier layer (C) and the inner surface layer (D)

[6] The heat-shrinkable laminated film according to any one of [1] to [5], wherein the haze is 20% or less.

[7] The heat-shrinkable laminated film according to any one of [1] to [6], wherein the haze after heat shrinkage is 50% or less.

[8] A bag comprising the heat-shrinkable laminated film according to any one of [1] to [7].

According to the present invention, it is possible to provide a heat-shrinkable laminated film having both slipperiness, transparency, and gloss, both of which have been difficult to be compatible with each other, and which is also excellent in sealing property.

Further, according to the bag using the film of the present invention, it is possible to carry out a reliable packaging operation efficiently. In addition, when the heat shrinkable packaging is carried out, it is less wrinkled, and has excellent gloss and transparency.

1 is a schematic view showing a preferable layer structure of the heat-shrinkable laminated film of the present embodiment.

(Hereinafter referred to as " present embodiment ") will be described concretely, but the present invention is not limited thereto, and various modifications may be made without departing from the gist of the present invention It is possible.

The heat-shrinkable laminated film of the present embodiment has an outer surface layer (A) located on at least one outermost surface and another inner layer. It is particularly preferable that at least four layers of the outer surface layer (A), the adhesive layer (B), the barrier layer (C) and the inner surface layer (D) are laminated in this order.

The heat-shrinkable laminated film of the present embodiment has a characteristic of being shrunk by heat (heat shrinkability), thereby enabling packaging in close contact with the contents.

Although the heat shrinkage ratio is not limited, it is preferable that the heat shrinkage percentage at 75 캜 in both the flow direction and the transverse direction is 10% or more and 50% or less.

Here, the flow direction and the transverse direction of the film refer to the longitudinal direction and the width direction (direction orthogonal to the flow direction) when the laminated film is extrusion-molded.

In the heat-shrinkable laminated film of the present embodiment, the outer surface layer (A) is one of the layers for maintaining the strength of the laminated film, and when the outer surface layer (A) is present only on one of the outermost surfaces, It is preferable to place it on the outside.

In the present embodiment, the outer surface layer (A) contains a resin or a resin composition and particles having an average particle diameter of 1.2 to 10.0 times the thickness of the outer surface layer (A). In this embodiment, by including such relatively large particles in the outer surface layer A, both transparency and gloss (after heat shrinkage), which have been difficult to achieve so far, and slip properties are realized.

The resin used for the outer surface layer (A) is not limited, but a resin having a relatively high melting temperature such as a propylene copolymer, an ester copolymer, and an amide resin can be preferably used.

Specific examples of the ester copolymer include polyethylene terephthalate, polybutylene terephthalate and the like. Specific examples of the amide resin include aliphatic amide resins such as nylon-6 and nylon-12; Aliphatic amide copolymers such as nylon-6,66 and nylon-6,12; Nylon-6,66,12, and other aliphatic ternary copolymers. Of these, nylon-6,66 is preferable in that high heat shrinkability can be obtained.

In the present embodiment, only the above-described number may be used as the constituent material of the outer surface layer (A), or a resin composition obtained by mixing the above-mentioned resin and various additives described below may be used as a constituent material of the outer surface layer .

In the heat-shrinkable laminated film of the present embodiment, it is more preferable that the heat shrinkage rate at 75 캜 in the flow direction and the transverse direction of the film is 15% or more and 50% or less.

By increasing the heat shrinkage ratio, the thickness of the outer surface layer (A) after heat shrinkage is further increased, and the effect of preventing the particles from falling off is further increased.

It is preferable that the heat shrinkage ratio is 20% or more in that the particles are prevented from falling out and the package is packed tightly and beautifully. On the other hand, if the film is excessively thickened by shrinkage, the transparency deteriorates. Therefore, the heat shrinkage ratio is preferably 50% or less.

The heat shrinkage ratio in the flow direction and the transverse direction need not be the same, but if the shrinkage difference along the direction is 20% or less, the pouch trim portion is preferable.

The heat shrinkage rate at 75 캜 in the flow direction and the transverse direction is preferably 25% or more and 45% or less, more preferably 30% or more and 45% or less . For example, when the content is meats, it is preferable because the preservation period can be extended.

The heat shrinkage rate of the film can be easily adjusted by suitably adjusting the stretching temperature and stretching ratio of the film.

In addition, the sum of the heat shrinkage ratios in the flow direction and the transverse direction is preferably 65% or more in that the package is packed tightly and beautifully.

There is no limitation on the thickness of the outer surface layer (A), but from the viewpoint of realizing transparency and high heat shrinkability, it is preferably 0.1 to 3.0 탆, more preferably 0.1 to 2.0 탆, even more preferably 0.1 to 1.0 탆 Do.

In the present embodiment, the outer surface layer (A) contains particles having an average particle diameter of 1.2 to 10.0 times the thickness thereof.

According to the study by the present inventors, the kind of particles is not limited, and it has been confirmed that the same effect can be obtained by using various particles. That is, they may be organic particles, inorganic particles, or organic-inorganic composite particles. In view of the fact that the shape (particle diameter) is hardly changed even in the heat at the time of melt extrusion, inorganic particles are preferable.

Examples of the organic particles include acrylic resin particles such as methyl polymethacrylate and styrene-methyl acrylate copolymer; Styrene resin particles; Polyester particles; Nylon particles; Fluorine resin particles and the like. Examples of the inorganic particles include metal oxide particles such as silica, zeolite, alumina, titanium oxide and zirconium oxide, calcium carbonate particles, barium sulfate particles, silicon particles and the like. However, in view of transparency, .

There is no particular limitation on the shape of the particles, and needle-like particles or flat plate-like particles may be used. In the case of spherical particles, spherical particles are preferred because of their low hooking and handling properties and their low slippage and film slipperiness.

If the average particle size of the particles is 1.2 to 10.0 times the thickness of the outer surface layer (A), irregularities can be obtained on the surface of the film before heat shrinkage, and a film having excellent slidability can be obtained.

Here, the average particle diameter refers to an average particle diameter determined by the Coulter method, and can be measured according to ISO 13319.

If the average particle diameter of the particles exceeds 10.0 times the thickness of the outer surface layer (A), the surface of the film is roughened, the transparency after heat shrinkage is lowered, and the particles fall off even after heat shrinkage.

The average particle diameter of the particles with respect to the thickness of the outer surface layer (A) is preferably 2.0 to 9.0 times, more preferably 3.0 to 7.0 times, from the viewpoints of slipperiness and prevention of particle dropout after heat shrinkage.

When the average particle size of the particles is 1.2 times or less the thickness of the outer surface layer (A), the particles are liable to adhere to the seal bar at the time of removal, and the sealing performance is deteriorated.

The smaller the difference between the refractive indexes of the base material and the contained particles of the outer surface layer (A) is, the better the transparency can be obtained. Therefore, when the resin constituting the outer surface layer (A) (the resin composition comprising the resin and the additive in the case where the outer surface layer (A) contains additives other than the resin and the particles) has a difference in refractive index between the particles and 0.05 And more preferably 0.03 or less.

The refractive index of each component refers to a value measured by Method B (liquid immersion method using a microscope (Baket line method)) in JIS K 7142 "Method of measuring refractive index of plastic".

The content of the particles of the outer surface layer (A) is not limited, but is preferably 0.02 to 1.00 mass%, and more preferably 0.10 to 0.80 mass% from the viewpoint of slipperiness and transparency.

To the outer surface layer (A), a surfactant such as a glycerin fatty acid ester surfactant, if necessary; Antioxidants; An antistatic agent; Various additives known in the fields of heat-shrinkable films such as petroleum resin, mineral oil, and fatty acid amide-based lubricants and bag films can be added to such an extent as not to impair transparency. Among them, when a fatty acid amide is added as a lubricant, stickiness of the film surface is suppressed, and slipperiness of the film is improved.

The heat-shrinkable laminated film of the present embodiment has an outer surface layer A positioned on the outermost surface of one side and another inner layer, and in particular, the outer surface layer A, the adhesive layer B, the barrier layer C, (D) are laminated in this order.

1, the heat-shrinkable laminated film of the present embodiment has the outer surface layer (A) 1, the adhesive layer (B) 2, the barrier layer (C) In addition to the surface layer (D) (5), various layers such as an adhesive layer (E) (4) for bonding the barrier layer (C) and the inner surface layer (D).

Hereinafter, layers other than the outer surface layer (A) will be described.

The inner surface layer D is the innermost layer when processed into a bag and serves as a heat seal layer for sealing the bag. The resin used in this layer is preferably a resin having a melting temperature of 65 to 150 DEG C lower than that of the resin used for the outer surface layer (A) in view of the superposed sealability. For example, polyethylene; Ethylene-α-olefin copolymer, ethylene copolymer such as ethylene-vinyl acetate copolymer, and the like, or a mixture thereof. Of these, an ethylene-? -Olefin copolymer is preferable because it has excellent stretchability and heat sealability.

In addition to the inner surface layer (D), a surfactant such as glycerin fatty acid ester; Antioxidants; An antistatic agent; Lubricants such as petroleum resin, mineral oil and fatty acid amide; Anti-blocking agents such as silicon oxide, calcium carbonate and talc; Various additives such as antimicrobial agents may be added to such an extent as not to impair sealing property and transparency.

The ratio of the thickness of the inner surface layer D to the total thickness (the range of 6 shown in Fig. 1) of the film constituent layers except for the outer surface layer A in the entire film layer (hereinafter, Is preferably 5 to 60%, more preferably 10 to 25% from the viewpoints of heat sealability and high heat shrinkability.

The barrier layer (C) is a layer having gas barrier properties, particularly oxygen barrier properties, and having a function of preventing oxidation deterioration of the contents when formed into a bag. The material of the barrier layer is not particularly limited, but vinylidene chloride copolymer can be preferably used from the viewpoint of oxygen barrier performance. The vinylidene chloride copolymer is a polymer of vinylidene chloride and other monomers. The kind of the other monomer is not particularly limited, but a vinyl chloride monomer or a methyl acrylate monomer is preferable. The content of vinylidene chloride in the vinylidene chloride copolymer is preferably 60 to 95% by weight, and more preferably 70 to 93% by weight.

Examples of the barrier resin other than the vinylidene chloride copolymer include, but are not limited to, vinylidene chloride homopolymers, ethylene-vinyl alcohol copolymers, polyamide resins, polychlorotrifluoroethylene resins, And a ronitryl resin.

These barrier resins may be used alone or in combination of two or more. In order to maintain the quality of the contents, the oxygen permeability of the barrier layer (C) is preferably 400 cc / m 2 · day · MPa (23 ° C. × 65% RH) or less.

In order to facilitate the melt processing and to stably manufacture the barrier layer, a heat stabilizer or a plasticizer may be added to the barrier layer within a range not affecting the effect of the present invention. Further, lubricants such as fatty acid amide-based lubricants and powders such as silicon oxide, calcium carbonate and talc may be added. These additives are preferably added in an amount of 1 to 10% by mass.

The thickness ratio of the barrier layer (C) to the total thickness of the film constituent layers excluding the outer surface layer (A) in the entire film is preferably 5 to 30%, more preferably 6 to 20% in view of good oxygen permeability More preferable.

Next, the adhesive layer (B) is a layer for bonding the outer surface layer (A) and the barrier layer (C), and the adhesion is improved by forming such a layer. As the material of the adhesive layer (B), it is preferable to use a polyolefin resin.

The polyolefin-based resin includes polyethylene; Polyethylene ionomers; Polypropylene; Ethylene-α-olefin copolymers, ethylene-vinyl acetate copolymers, ethylene copolymers such as ethylene-acrylic acid copolymers, ethylene-ethyl acrylate copolymers and ethylene-maleic anhydride copolymers and modified polyolefins.

An adhesive layer (B ') may further be present above and below the adhesive layer (B) for the purpose of adhering the layer.

The ratio of the thickness of the adhesive layer (B) to the total thickness of the film constituent layers except for the outer surface layer (A) in the entire film layer is preferably 10 to 70%, more preferably 25 to 65% More preferable.

The heat-shrinkable laminated film may be irradiated with ionizing radiation before the stretching process. Thus, in particular, the adhesive layer (B) is crosslinked, and the stretchability of the film is imparted. The effect depth of ionizing radiation is usually controlled by the accelerating voltage. The ionizing radiation irradiation path irradiates ionizing radiation such as? Rays,? Rays,? Rays, neutron rays, and electron beams.

The method for producing the heat-shrinkable laminated film of the present embodiment is not limited. For example, a resin composition prepared by previously mixing particles as a constituent material of the outer surface layer (A) is prepared, .

Specifically, the laminated film can be produced by a method such as a single bubble inflation method, a double bubble inflation method, a triple bubble inflation method, or a tenter method.

The double bubble inflation method and the triple bubble inflation method are preferable from the balance of physical properties of the resulting film.

Here, the outline of the double bubble inflation method will be described.

The pellets of the resin (resin composition) constituting each layer are melted at a melting temperature of the resin or higher and the layers are simultaneously extruded using an extruder having a number corresponding to the number of layers. A polymer pipe, and a die, to form a laminated film. This is cooled and solidified by water cooling or the like.

Next, the outer surface layer (A) side is irradiated with ionizing radiation and crosslinked at a desired gel fraction. In terms of irradiation, the accelerating voltage is preferably 150 to 300 kV in terms of stretchability, and the irradiation dose is preferably 20 to 150 kGy.

Next, the film on the tube is led to the stretching process. The stretching magnification of the film is preferably 2.0 to 6.0 times in both the flow direction (MD) and the width direction (TD), preferably 2.5 to 4.0 times in terms of heat shrinkability, good transparency after heat shrinkage and production stability desirable. It is more preferable to preheat and stretch at 60 to 98 占 폚 prior to stretching. As the stretching method, stretching by the bubble inflation method is preferable in terms of transparency.

The stretching temperature of the heat-shrinkable laminated film is preferably 50 to 90 占 폚 in order to obtain dimensional stability after heat treatment, heat shrinkability, and good transparency after shrinkage. And more preferably at 60 to 80 ° C. In the case of the bubble inflation method, the stretching temperature can be measured by measuring the surface of a film called a neck portion at the start of stretching of the inflation bubble with a thermometer.

In the present embodiment, in order to suppress curling of the film which deteriorates operability during slitting and filling of the bag when used in a continuous atmosphere after stretching, a heat treatment called a heat set is performed at a temperature of 40 to 80 캜 For several seconds.

The heat-shrinkable laminated film of the present embodiment may be subjected to surface treatment or printing treatment such as corona treatment or plasma treatment, if necessary.

Although the thickness of the heat-shrinkable laminated film is not limited in the present embodiment, it is preferably 20 to 150 占 퐉, more preferably 25 to 80 占 퐉, from the viewpoints of barrier property, strength of bag and productivity.

When the film is produced by the inflation method as described above, it is possible to adjust the film thickness by adjusting the area elongation magnification in simultaneous biaxial stretching.

The heat-shrinkable laminated film of the present embodiment can be processed into a bag.

For example, it can be used as a two-seam pocket, commonly referred to as a bottom seal bag. Such a bag can be produced mainly by subjecting a film on a tube to sealing and cutting in the width direction. Processing into the bag and packaging may be performed at the same time. For example, usually, a film on a tube is subjected to sealing and cutting in the width direction, the contents are put, and the inlet is sealed.

In addition, it can also be used as a bag commonly called a side seal bag. Such a bag can be produced by subjecting the film to a fusing seal or the like.

With respect to the transparency of the heat-shrinkable laminated film of the present embodiment, the haze (HAZE) (before heat shrinkage) is preferably 20% or less, more preferably 15% or less, % Or less.

Here, the degree of cloudiness can be measured according to ASTM D-1003.

The package that is vacuum-packed with the heat-shrinkable laminated film of the present embodiment is heated at about 70 to 130 ° C (for example, immersed for several seconds in hot water bath at 70 to 100 ° C, The film is left to stand for a second time, or the like), the heat-shrinkable laminated film is heat shrunk and finished in a tight and beautiful package.

For example, in growing packaging, packing tightly and tightly improves the tackiness of the packed meat and increases the value of the product. In addition, the effect of suppressing the juice or blood stain and consequently suppressing the decay of the contents can be obtained.

It is preferable that the film after heat shrinkage exhibits good transparency and color tone in order to finish the packaging smoothly and maintain the visibility of the contents to raise the value of the product. From such a viewpoint, the heat shrinkable laminated film of the present embodiment preferably has a haze after heat shrinkage of 50% or less, more preferably 40% or less, and still more preferably 30% or less. Here, the term "heat shrinkage" refers to after immersing the film in a hot water tank at 75 ° C. for 4 seconds.

It is preferable that the coefficient of static friction between the outer surface layers A is larger than 0.1 and not larger than 1.0 in view of handleability. If the coefficient of static friction is 1.0 or less, the film can be well fed. If the coefficient of static friction is 0.1 or more, the film is too slippery to be wound around rollers in the atmosphere.

Example

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples.

The evaluation methods of various physical properties are as follows. Here, the flow direction (longitudinal direction) of the heat-shrinkable laminated film from the extruder is referred to as MD direction, and the transverse direction (width direction) perpendicular to the MD direction is referred to as TD direction.

"Average particle size"

Measurement apparatus: The average particle diameter was measured using a Coulter Multisizer Particle Measuring Apparatus TA-II manufactured by Nikkaki Co., Ltd.

Measurement method: Measurement was carried out in accordance with ISO13319 " Method of obtaining particle diameter distribution-electric detection method ", and the average particle diameter was calculated according to JIS Z 8819-2.

&Quot; Evaluation of heat shrinkage rate at 75 캜 "

Measurement method: Measurement was performed according to ASTM D-2732. Specifically, measurements were carried out in the following order.

(I) A mark (100 mm) in the flow direction (MD) and the transverse direction (TD) of the measurement specimen (the film of the example) was dipped in a hot water bath at 75 캜 for 4 seconds to free heat shrink.

(Ii) After shrinkage, the interval between marks was measured, and the heat shrinkage rate of the film was determined from the following equation.

Heat shrinkage (%) at 75 캜

= ((100 (mm) - interval after shrinkage (mm)) / 100 (mm)) 100

"Cloudiness before heat shrinkage"

Measurement apparatus: NDH2000 haze meter (HAZE meter, trade name) manufactured by Nippon Seimei Kogyo Co., Ltd. was used.

Measurement method: Measurement was carried out according to ASTM D-1003. Specifically, the measurement specimen (the film of the example) was superimposed on two sheets and the degree of blur (%) was measured. The smaller the value of cloudiness, the higher the transparency.

&Quot; Cloudiness after heat shrinkage "

Measurement apparatus: NDH2000 haze meter (HAZE meter) manufactured by Nippon Seisakusho Co., Ltd. was used.

Measurement method: Measured according to ASTM D-1003. Specifically, the measurement sample (the film of the example) was immersed in a hot water bath at 75 캜 for 4 seconds, free heat shrinked, and the degree of fogging thereof was measured. The smaller the value of cloudiness, the higher the transparency.

&Quot; Evaluation of oxygen barrier property (oxygen permeability) "

Measurement apparatus: An oxygen permeation analyzer (OX-TRAN (registered trademark) 200H) manufactured by MOCON was used.

Measurement method: The values of the oxygen permeability (cc / m 2 dayday ㎫ MPa) after 3 hours were measured with the measurement samples (films of Examples and Comparative Examples) under 65% RH and a temperature of 23 캜. The smaller the oxygen permeability, the greater the oxygen barrier property.

&Quot; Evaluation of slip property (static friction coefficient) "

Measurement apparatus: TR-2 friction measuring machine manufactured by TOYOSHI KOGYO Co., Ltd. was used.

Measurement method: Measurement was conducted in accordance with JIS-K-7125 " Friction Coefficient Test Method ". Specifically, the multilayered films of Examples and Comparative Examples were physically peeled off, and only the outer surface layer (A) was used, and the coefficient of static friction on the outermost surface side of the outer surface layer (A) was measured. The larger the value of the static friction coefficient, the lower the slipperiness.

[Examples 1-3, 8, 9 and 12]

A laminated film of five layers was produced by the double bubble inflation method.

(B) = 35%, the barrier layer (C) = 10%, the adhesive layer (E) = 30%, the inner surface layer (D) = And a resin extrusion amount of 25% was molded by a double bubble inflation method.

Thereafter, biaxial stretching was carried out at the draw ratio shown in Table 1 in the MD and TD directions to obtain a stretched laminated film having the thicknesses of the whole layer and the outer surface layer (A) as shown in Table 1. The stretching magnification in the MD direction was controlled by the speed ratio of the pinch rolls between bubbles, and the stretching magnification in the TD direction was controlled by the volume of air enclosed in the bubbles.

The outer surface layer (A) was prepared by adding a resin composition in which zeolite particles (JC-20 manufactured by Mizusawa Chemical Co., Ltd., refractive index: 1.50, average particle size: 2 m) were added in an amount shown in the table to nylon-6,66 (refractive index: Lt; / RTI >

[Example 4]

A stretched laminated film was obtained in the same manner as in Example 1, except that polymethyl methacrylate particles (Eposta MA1002, manufactured by Nippon Shokubai Co., Ltd., refractive index: 1.51, average particle size: 2 m) was used as particles added to the outer surface layer .

[Examples 5 and 6]

A stretched laminated film was obtained in the same manner as in Example 1, except that zeolite particles (JC-50 manufactured by Mizusawa Chemical Co., Ltd., refractive index: 1.50, average particle size: 5 m) was used as particles added to the outer surface layer (A).

[Example 7]

A stretched laminated film was obtained in the same manner as in Example 1 except that polymethyl methacrylate particles (Eposta MA1010, manufactured by Nippon Shokubai Co., Ltd., refractive index: 1.51, average particle size: 10 mu m) was used as particles added to the outer surface layer (A) .

[Example 10]

A stretched laminated film was obtained in the same manner as in Example 1 except that silica particles (SO-E6 manufactured by Admatech Co., Ltd., refractive index: 1.45, average particle size: 2 m) were used as particles added to the outer surface layer (A).

[Example 11]

A stretched laminated film was obtained in the same manner as in Example 1 except that calcium carbonate particles (Silver-W produced by Shiraishi Kogyo Co., Ltd., refractive index: 1.60, average particle diameter: 1.5 mu m) was used as particles added to the outer surface layer (A).

The results are shown in Table 1 below.

The heat-shrinkable laminated film of the present invention can be used for various applications requiring heat shrinkage.

Particularly, since the heat-shrinkable laminated film of the present invention is excellent in transparency and slipperiness, it can be preferably used as a material for a packaging bag.

1: outer surface layer (A)
2: Adhesive layer (B)
3: barrier layer (C)
4: Adhesive layer (E)
5: inner surface layer (D)
6: the sum of the thicknesses of the film constituting layers excluding the outer surface layer (A) in the entire film layer

Claims (8)

A heat-shrinkable laminated film having an outer surface layer (A) on at least one of its outermost surfaces,
Wherein the outer surface layer (A) contains particles having an average particle diameter of 1.2 to 10.0 times the thickness of the outer surface layer (A). The method according to claim 1,
Wherein the outer surface layer (A) has a thickness of 0.1 to 3.0 占 퐉. 3. The method according to claim 1 or 2,
Wherein the outer surface layer (A) comprises a resin or a resin composition and the particles,
Wherein the difference between the refractive index of the resin or the resin composition and the particle is 0.05 or less. 4. The method according to any one of claims 1 to 3,
Wherein the heat shrinkage ratio at 75 캜 in the flow direction and the transverse direction is not less than 10% and not more than 65%. 5. The method according to any one of claims 1 to 4,
Further comprising an adhesive layer (B), a barrier layer (C) and an inner surface layer (D)
An outer surface layer (A), an adhesive layer (B), a barrier layer (C) and an inner surface layer (D) are laminated in this order. 6. The method according to any one of claims 1 to 5,
A heat shrinkable laminated film having a haze of 20% or less. 7. The method according to any one of claims 1 to 6,
Shrinkage after heat shrinkage is 50% or less. A pouch comprising the heat-shrinkable laminated film according to any one of claims 1 to 7.

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