JP2018135139A - Film for packing material, packing material and package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use a packaging material film and a packaging material film which have good slipperiness and blocking resistance in a processing process and also have good low temperature heat sealability without adding an anti-blocking agent or a lubricant. We provide packaging materials and packaging. A packaging material film 5 has a sealant film 3 (first layer 3) containing a thermoplastic resin as a main resin, and has a first uneven shape 1 formed on the entire surface of the sealant film 3. A second uneven shape 2 formed on the first uneven shape 1 and having an average roughness smaller than that of the first uneven shape 1 is provided, and the surface of the sealant film 3 has an arithmetic average roughness Ra. It is 0.5 μm or more and 2.0 μm or less, and the ten-point average roughness Rz is 4.0 μm or more and 12.0 μm or less. [Selection diagram] Fig. 1

Description

  The present invention relates to a film for packaging material, a packaging material, and a package.

The packaging material is used for, for example, a packaging bag (packaging body) for packaging foodstuffs, medicines, and the like. The contents stored in the packaging bag have various states such as liquid, powder, paste, and solid. Also, for such packaging bags, for example, plastic film packagings using films of polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, polyamide, polyester, etc. are often used. Yes.
Such a packaging bag is required to have characteristics such as filling suitability at the time of filling the contents, absence of damage to the bag when an external force is applied to the packaging material, air tightness, and unsealing property when opening the packaging bag. In order to obtain such a packaging bag, the packaging material has good impact resistance, heat sealability, tearability, rigidity, barrier properties, etc., as well as good slipping, blocking resistance, and winding properties in the processing process. Such characteristics are also required.

For example, by using low-density polyethylene or the like for the film, it can have good impact resistance and low-temperature heat-sealing properties, but there arises a problem that it is poorly slidable in the processing step and easily blocked. When the slipperiness is poor, the generation of wrinkles and the winding property of the film are deteriorated. In the case where blocking is likely to occur, the appearance of blocking traces, film breakage in printing and laminating processes, and yield reduction due to tension fluctuations occur.
In order to solve these problems of slipperiness and blocking property, it is sometimes possible to take measures such as mixing a lubricant or an antiblocking agent with low density polyethylene. For example, in Patent Document 1, this problem is solved by defining two types of lubricants and anti-blocking agents.

Japanese Patent No. 5628132

However, in the method described in Patent Document 1, the management items and costs due to mixing many prescribed additives increase, and the amount of lubricant is large, so that the slipperiness changes with time. There is.
The slipping property changes depending on the type of the thermoplastic resin, the presence / absence / type of adhesive, the temperature condition, and the like, but the lubricant moves to the surface due to a change over time after film formation or after temperature change. That is, the lubricant bleeds out over time. For this reason, the lubricity changes due to storage conditions and product processing conditions. In addition, the lubricant is transferred to the back surface or another film in contact with the bleed-out surface of the lubricant, and the sliding property of the transferred surface is also changed. Therefore, in order to obtain a stable slipperiness, it is desired not to use a lubricant.

  The present invention provides a film for a packaging material, a packaging material, and a packaging body that have good slipperiness, blocking resistance, and low-temperature heat sealability in a processing step without using a lubricant or an antiblocking agent. For the purpose.

In order to solve the problem, a film for packaging material according to one embodiment of the present invention has a sealant film having a thermoplastic resin as a main resin, and has a first uneven shape formed on the entire surface of the sealant film. A second concavo-convex shape formed on the first concavo-convex shape and having an average roughness smaller than that of the first concavo-convex shape, and the surface of the sealant film has an arithmetic operation of the first concavo-convex shape. The average roughness Ra is 0.5 μm or more and 2.0 μm or less, the ten-point average roughness Rz of the first uneven shape is 4.0 μm or more and 12.0 μm or less, and the arithmetic average of the second uneven shape The roughness Ra is 0.15 μm or more and 0.35 μm or less, and the number of convex shapes of the first concavo-convex shape is 100 or more and 400 or less per 1 mm ² .

  According to one embodiment of the present invention, a film for packaging material used for a packaging material and a packaging body has good slipperiness and blocking resistance in a processing step without using a lubricant or an antiblocking agent. A film for packaging material can be provided. As a result, it is possible to provide a packaging material and a packaging body having sufficient sliding properties and low-temperature heat sealing properties.

It is sectional drawing which showed an example of embodiment of the film for packaging materials of this invention. It is sectional drawing which showed an example of embodiment of the packaging material of this invention. It is a schematic diagram of the package using the film for packaging material of the present invention. It is sectional drawing of the standing pouch using the film for packaging materials of this invention. It is a schematic diagram which shows the manufacturing process of the standing pouch using the film for packaging materials of this invention.

Embodiments of the present invention will be described below with reference to the drawings.
Each figure is a schematic diagram, and the size, shape, and the like of each part are appropriately exaggerated for easy understanding. For the sake of simplicity, the same reference numerals are given to corresponding parts in the drawings. Furthermore, the embodiment of the present invention exemplifies a configuration for embodying the technical idea of the present invention, and specifies the material, shape, structure, arrangement, dimensions, etc. of each part as follows. Not. The technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the claims.

(overall structure)
Fig.1 (a) is a figure which shows an example of the cross-sectional structure of the film 5 for packaging materials of this embodiment. A film for packaging material 5 shown in FIG. 1 (a) is composed of a sealant film made of a thermoplastic resin. On the surface (one surface) of the film for packaging material 5, the first uneven shape 1 and the first A fine uneven shape 2 (second uneven shape) formed on at least a part of the uneven shape 1 is formed. It is preferable that the material of the thermoplastic resin constituting the sealant film has an appropriate flexibility and a good workability, for example, a processability by an extruder. Examples of the thermoplastic resin material having such performance include low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), and homopolymer, Random copolymer, polypropylene with block copolymer, ethylene vinyl acetate copolymer obtained by copolymerizing the olefin and vinyl acetate, ethylene-methyl acrylate copolymer (EMA) obtained by modifying the side chain of olefin, ethylene-ethyl Examples thereof include an acrylate copolymer (EEA), an ethylene-butyl acrylate copolymer (EBA), and an ethylene-methacrylic acid copolymer (EMAA). These materials may be used alone, or a plurality of these materials may be used in combination.

In consideration of rigidity, impact resistance, heat sealability, and tearability, the thermoplastic resin is preferably mainly composed of polyethylene or a derivative thereof. Furthermore, the film 5 for packaging materials consists of at least 2 layers like FIG. Here, the first layer 3 and the second sealant film constituting the first sealant film are formed in order from the surface of the film 5 for packaging material, with the two layers on the surface side having unevenness in the film 5 for packaging material. This is called the second layer 4 to be configured.
The first layer 3 preferably has an average density of 0.910 g / cm ^{3 to} 0.920 g / cm ³ and a thickness of 5 μm to 30 μm. The second layer 4, an average density of 0.925 g / cm ³ or more 0.940 g / cm ³ or less, it is preferable that the thickness is 30 .mu.m to 100 .mu.m.

Here, “mainly” and “main component” in this specification represent 70% or more by mass ratio of the resin used for the target layer. Moreover, an average density is the value measured by the measuring method based on JISK7112: 1999, or the measuring method comparable with this.
Here, the first layer 3 is used as a seal layer. When the average density of the resin used in the first layer 3 is less than 0.910 g / cm ³ , the rigidity of the packaging material film 5 may be too weak. On the other hand, when the average density is larger than 0.920 g / cm ³ , when heat-sealing as a package, the sealing strength at low temperature may be insufficient.

When the average density of the resin used in the second layer 4 is less than 0.925 g / cm ³ , the rigidity of the packaging material film 5 may be too weak. On the other hand, when the average density is larger than 0.940 g / cm ³ , the impact resistance of the packaging material film 5 may be deteriorated.
The total thickness of the packaging material film 5 is preferably 50 μm or more and 150 μm or less. If it is thinner than 50 μm, the resin used for heat sealing is insufficient, and the heat sealability as a packaging material is low, which may cause problems. On the other hand, if it is thicker than 150 μm, the overall tearability may be too poor and the material cost will be very high.

The thickness of the resin used in the first layer 3 is preferably 5 μm or more and 30 μm or less. When the thickness is less than 5 μm, the heat seal strength may be insufficient, and when the thickness is greater than 30 μm, the rigidity tends to be insufficient. The thickness of the resin used in the second layer 4 is preferably 30 μm or more and 100 μm or less. When the thickness is less than 30 μm, the package may have insufficient rigidity, and when the thickness is more than 100 μm, the package tends to have insufficient tearability.
Moreover, it is good to mix the linear low density polyethylene (LLDPE) and the low density polyethylene (LDPE) in resin which comprises the 1st layer 3 and the 2nd layer 4 together. By mixing LDPE with LLDPE, the above-mentioned various physical properties and workability such as neck-in and fish eye can be made compatible. More preferably, the mass ratio of LLDPE: LDPE is mixed at a ratio of 99: 1 to 70:30.

  In general, impact resistance and heat sealability can be improved by using a low-density resin for the thermoplastic resin. End up. However, the packaging material film 5 has a two-layer structure as shown in FIG. 1A, the first layer 3 is a low density resin, the second layer 4 is a medium to high density resin, and the density and thickness described above. By setting it as the range, it is possible to improve the bending rigidity and the tearing property while improving the impact resistance and the heat sealability. Furthermore, by having the 1st uneven | corrugated shape 1 and the fine uneven | corrugated shape 2 on the surface, slipperiness and blocking resistance can also be made favorable.

  Furthermore, the packaging material film 5 may have a multilayer structure in which desired physical properties are complemented by laminating three or more sealant films as shown in FIG. 1B, for example. As an example of a multilayer structure, in order to further increase the rigidity of the packaging material film 5, a resin layer having a higher density than the resin used for the first layer 3 and the second layer 4 is provided, and a third layer is provided below the second layer 4. In order to suppress curling due to heat shrinkage of the film for packaging material, a resin layer having the same density as that of the first layer 3 may be used as a third layer under the second layer 4. good.

  As for the 1st uneven | corrugated shape 1 formed in the film 5 for packaging materials of this embodiment, arithmetic mean roughness Ra is 0.5 micrometer or more and 2.0 micrometers or less, and 10-point average roughness Rz is 4.0 micrometers or more and 12. It is good that it is 0 μm or less. The first concavo-convex shape 1 mainly has a role of improving blocking resistance. If the roughness is smaller than the above, the blocking resistance may be insufficient. Especially, in the film at the core part at the time of winding the film, the pressure is increased due to the load due to gravity compared to the outside of the winding. Such a tendency tends to occur. Moreover, when larger than the said roughness, it will become easy to bite air when heat-sealing with a film piled up, and as a result, low-temperature heat-sealing property will fall. Furthermore, when the roughness is too large, the thickness of the concave portion is locally thinned, resulting in a problem that impact resistance and rigidity are deteriorated.

Furthermore, the number of convex shapes of the first uneven shape 1 is preferably 100 or more and 400 or less per 1 mm ² . When the number of convex shapes is less than 100, the blocking resistance is reduced, and blocking tends to occur locally. When the number of convex shapes is more than 400, it becomes easy to bite air at the time of heat sealing, resulting in a decrease in low-temperature heat sealing performance.
The fine concavo-convex shape 2 constituting the second concavo-convex shape mainly has a role of improving slipperiness. The fine uneven shape 2 preferably has an arithmetic average roughness Ra of 0.15 μm or more and 0.35 μm or less. If Ra is smaller than 0.15 μm, processing itself becomes difficult, the friction coefficient becomes large, and the slipperiness becomes insufficient. If Ra is larger than 0.35 μm, the friction coefficient becomes too small and the slipperiness becomes too good.

  By having both the 1st uneven | corrugated shape 1 and the fine uneven | corrugated shape 2 which are appropriate like this embodiment, slipperiness, blocking resistance, and low-temperature heat-sealing property become favorable. If either of them is insufficient, for example, when the film is transported or when the films are overlapped, the film is wrinkled or the film is stretched due to an increase in take-up tension. Further, the films after winding are in close contact with each other, and problems such as uneven appearance, tension fluctuation, and film breakage occur.

(Opposite side)
In the packaging material film 5, it is not necessary to form the uneven shape as described above on the surface (back surface side) opposite to the surface where the uneven shape is formed, and the roughness of the opposite surface is limited. It is not a thing. This is because the blocking resistance and slipping property of the packaging material film 5 can be ensured by the uneven shape.

(Production method)
The method for producing the packaging material film 5 of the present embodiment is not particularly limited, and a known method can be used. For example, there are methods such as coextrusion using a feed block, dry lamination, extrusion lamination, and the like. From the viewpoint of production efficiency, it is preferable to produce by a coextrusion method using a feed block. When the reverse shape of the uneven shape is prepared on the cooling roll and the molten resin is cooled and solidified, the uneven shape can be imparted (transferred) to the resin film surface by pressing with a nip roll.
In order to obtain the packaging material 9 and the packaging body 30 of this embodiment, it is necessary to form the base material 7 and the functional layer 8 which are mentioned later on the surface opposite to an uneven | corrugated shape (refer FIG. 2). In order to improve the adhesion between the packaging material film 5 and the base material 7 or the functional layer 8, it is desirable that the unevenness on the opposite surface (back surface side) of the packaging material film 5 is not so large.

(Packaging material)
As shown in FIG. 2, the packaging material 9 has a substrate 7 on the surface opposite to the surface on which the concavo-convex shape is formed with respect to the packaging material film 5, and further, a printed layer, a barrier layer, and the like. By forming the functional layer 8, a packaging material 9 having the effects of the present invention can be obtained. In FIG. 2A, a configuration example in which the base material 7 is laminated via the adhesive layer 6, and in FIG. 2B, the base material 7 and the functional layer 8 are laminated via the adhesive layer 6. Although the example of a structure is shown, it is not restricted to this, It is good also as a multilayer structure of four or more layers by further laminating | stacking the functional layer 8. FIG.

(Base material)
The base material 7 is a layer that functions as a support for the packaging material 9, a film mainly made of plastic is used, and is appropriately selected depending on use conditions such as the type of contents and the presence or absence of heat treatment after filling. Examples of the material for the base material 7 include polyethylene, polypropylene, polyethylene terephthalate, and nylon (registered trademark), but are not particularly limited. Furthermore, it may be a single layer made of one of the materials, or may be a layer in which a plurality of materials are combined by stacking such single layers.

(Functional layer)
Examples of the functional layer 8 include a printing layer and a barrier layer. The barrier layer is a layer having a function of improving the barrier property for protecting the packaging material from a gas such as oxygen contained in the air, water vapor, enclosed contents, and the like. As a material, for example, EVOH (ethylene- Vinyl alcohol copolymer) and metals such as aluminum, and the like can be used as appropriate.

(Additive)
The film 5 for packaging material and the base material 7 can be appropriately added with materials generally used for films in order to improve the suitability for film and sheet forming and the suitability for using films and sheets. It is. For example, an antioxidant for imparting processing stability can be appropriately added.

(Packaging body)
The example of the manufacturing method of the package 30 which made the film 5 for packaging materials of this embodiment is demonstrated with reference to FIG. As shown in FIG. 3, first, two packaging bodies 30 are removed from the packaging material 9 by applying a shape with a mold or the like. Then, the front and back are bent so that the first layers 1 arranged in the outermost layer face each other. Finally, the periphery 30 is heat-sealed to make a bag, thereby obtaining the package 30 having the above-described effects of the present invention.
Examples of the package 30 using the packaging material 9 of the present embodiment include a standing pouch, a packaging bag, a pouch with a cap, a lami tube, a back-in box, and the like, but can be used for various other purposes.

(Standing pouch)
As an example of the package 30, a structure and a manufacturing method when the packaging material 9 of the present invention is employed in a standing pouch will be described with reference to FIGS. 4 and 5. A standing pouch is a kind of container for storing liquid, powder, solid, such as toiletries such as liquid detergents, softeners, shampoos and rinses, and foods such as edible oil and instant coffee. In addition to the bag making method similar to that of the package 30 described above, the packaging material 9 is used as a bottom tape, and is inserted between the front surface of the main body and the back surface of the main body to seal the periphery. 4 is a cross-sectional view of the standing pouch 10, and FIG. 5 is a schematic view showing a state during web conveyance before the standing pouch 10 is formed.

Hereinafter, the standing pouch 10 obtained in the present embodiment will be described in detail.
As shown in FIG. 5, the standing pouch 10 has a pouch surface 12 and a pouch back surface 13 by bending the packaging material film 5 of the present embodiment with the packaging material film 5 inside. At that time, the left and right side seal portions 22 and the peripheral seal portion formed by the bottom seal portion 23 indicated by hatching in FIG. 5 are heat sealed to form a package.
Furthermore, the bottom tape 20 with the packaging material film 5 outside is formed separately, and the bottom tape 20 is inserted between the pouch surface 12 and the pouch back surface 13 to seal the periphery, thereby providing self-supporting properties. Can do.

In addition, a pouring nozzle 16 for pouring out the contents is formed on the upper portion of the standing pouch 10 by the pouch surface 12, the pouch back surface 13, and the pouring nozzle seal portion 24. The extraction nozzle seal portion 24 is a seal portion that is provided continuously to the side seal portion 22, and is provided below the extraction nozzle 16.
The dispensing nozzle 16 is formed with a dispensing nozzle tip seal portion 25 whose tip is heat-sealed, and functions as an opening knob 18 separated and formed by an opening cut line 17 provided on the dispensing nozzle seal portion 24. To do. That is, the user can form the spout (not shown) by holding the opening knob 18 and cutting along the previously formed half-cut line 19. Note that the present invention is not limited to this method, and a cap cap made of resin or the like may be provided separately, and the function of the extraction port may be provided by opening and closing the lid.

The half-cut line 19 is provided on each of the pouch surface 12 and the pouch back surface 13. As a method for forming a half-cut line, a method of forming with a blade or a method of forming by laser processing is generally used, but the method by laser processing is preferable because a uniform and stable cut can be formed. As the type of laser, a carbon dioxide laser is more preferable.
As an example of the manufacturing method of the standing pouch 10, as shown in FIG. 5, a film for packaging material having a width slightly more than twice the height when the standing pouch 10 is self-supported is drawn out into a web shape. A cut line 19 is formed. Thereafter, the laminated body is bent at the bent portion ridge line 21 to form the pouch surface 12 and the pouch back surface 13, and the bottom tape 20 is inserted to perform heat sealing of the peripheral portion, and punching into a predetermined shape. Can be configured.

In addition, other features such as forming a continuous embossed portion 26 from the pouch surface 12 to the pouch back surface 13 via the bent portion ridge line 21 may be provided in the dispensing nozzle 16. . That is, by using the packaging material film 5 of the present invention, the standing pouch 10 having the above-described effects can be obtained.
As mentioned above, although embodiment of this invention was illustrated, this invention is not limited to the said embodiment, Unless it deviates from the technical idea of this embodiment, it considers the use as a packaging material, and is requested | required. Needless to say, other layers and structures can be arbitrarily formed for the purpose of improving other physical properties such as rigidity, strength, impact property and the like.

Examples of the present invention will be described in detail below, but the present invention is not limited to the following examples.
Example 1
The film 5 for packaging material is a two-layer laminated film as shown in FIG. 1A, and a linear low density polyethylene resin (density 0.913 g / cm ³ , MFR ( Melt Flow Rate (melt flow rate) 3.8) and low density polyethylene resin (density 0.924 g / cm ³ , MFR 1.0) were blended at a ratio of 80:20. Further, as the thermoplastic resin of the second layer 4, a linear low density polyethylene resin (density 0.931 g / cm ³ , MFR 3.2) and a low density polyethylene resin (density 0.924 g / cm ³ , MFR 1.0). Were blended at a ratio of 80:20. In addition, neither lubricant nor antiblocking agent is added in the two layers. The first layer 3 and the second layer 4 were heated and melted at a discharge temperature of 260 ° C. and extruded by coextrusion.

On the surface of the cooling roll, the first uneven shape 1 has an arithmetic average roughness Ra = 0.50 μm, a ten-point average roughness Rz = 4.4 μm, a number of convex portions of 400 / mm ² , and a fine uneven shape. 2 having a shape having an arithmetic average roughness Ra = 0.25 μm is prepared, arranged so that a cooling roll having a surface shape is in contact with the surface of the first layer 3, and the molten resin is sandwiched between the nip roll and the cooling roll. Thus, a film 5 for packaging material having a thickness of the first layer 3 of 15 μm, a thickness of the second layer 4 of 85 μm, and a total thickness of 100 μm was obtained.

(Example 2)
The roughness of the surface of the cooling roll is as follows: the first uneven shape 1 has an arithmetic average roughness Ra = 1.1 μm, a ten-point average roughness Rz = 6.7 μm, and the number of protrusions is 200 / mm ² , Prepare shape 2 with a shape having arithmetic average roughness Ra = 0.25 μm, and place it so that the cooling roll with surface shape is in contact with the surface of first layer 3, and put the molten resin on the nip roll and cooling roll A film was formed by sandwiching. Other parts were the same as in Example 1, and a film for packaging material 5 was obtained.

(Example 3)
The roughness of the surface of the cooling roll is large and the first irregular shape 1 is fine with arithmetic average roughness Ra = 2.0 μm, ten-point average roughness Rz = 11.0 μm, several hundred protrusions / mm ^2. An uneven shape 2 having a shape with an arithmetic average roughness Ra = 0.25 μm is prepared, arranged so that a cooling roll having a surface shape is in contact with the surface of the first layer 3, and the molten resin is a nip roll and a cooling roll. The film was formed by being sandwiched between the two. Other parts were the same as in Example 1, and a film for packaging material 5 was obtained.

Example 4
The roughness of the surface of the cooling roll is as follows: the first uneven shape 1 has an arithmetic average roughness Ra = 1.1 μm, a ten-point average roughness Rz = 6.7 μm, and the number of protrusions is 200 / mm ² , Prepare shape 2 with a shape having arithmetic average roughness Ra = 0.15 μm, and place the cooling roll with the surface shape in contact with the surface of the first layer 3, and place the molten resin on the nip roll and cooling roll. A film was formed by sandwiching. Other parts were the same as in Example 1, and a film for packaging material 5 was obtained.

(Example 5)
The roughness of the surface of the cooling roll is as follows: the first uneven shape 1 has an arithmetic average roughness Ra = 1.1 μm, a ten-point average roughness Rz = 6.7 μm, and the number of protrusions is 200 / mm ² , Prepare shape 2 with a shape having arithmetic average roughness Ra = 0.35 μm, and place it so that the cooling roll with the surface shape is in contact with the surface of the first layer 3, and put the molten resin on the nip roll and the cooling roll. A film was formed by sandwiching. Other parts were the same as in Example 1, and a film for packaging material 5 was obtained.

(Comparative Example 1)
The roughness of the surface of the cooling roll is as follows: the first uneven shape 1 has an arithmetic average roughness Ra = 2.5 μm, a ten-point average roughness Rz = 13.7 μm, and the number of protrusions is 75 pieces / mm ^2. Prepare shape 2 with a shape having arithmetic average roughness Ra = 0.25 μm, and place it so that the cooling roll with surface shape is in contact with the surface of first layer 3, and put the molten resin on the nip roll and cooling roll A film was formed by sandwiching. Other parts were the same as in Example 1, and a film for packaging material 5 was obtained.

(Comparative Example 2)
The roughness of the surface of the cooling roll is as follows: the first uneven shape 1 has an arithmetic average roughness Ra = 1.1 μm, a ten-point average roughness Rz = 6.7 μm, and the number of protrusions is 200 / mm ² , Prepare shape 2 with an arithmetic average roughness Ra = 0.10 μm and place it so that the cooling roll with the surface shape is in contact with the surface of the first layer 3, and put the molten resin on the nip roll and cooling roll A film was formed by sandwiching. Other parts were the same as in Example 1, and a film for packaging material 5 was obtained.

(Comparative Example 3)
The roughness of the surface of the cooling roll is as follows: the first uneven shape 1 has an arithmetic average roughness Ra = 1.1 μm, a ten-point average roughness Rz = 6.7 μm, and the number of protrusions is 200 / mm ² , Prepare shape 2 with an arithmetic average roughness Ra = 0.50 μm and place it so that the cooling roll with the surface shape is in contact with the surface of the first layer 3, and put the molten resin on the nip roll and cooling roll A film was formed by sandwiching. Other parts were the same as in Example 1, and a film for packaging material 5 was obtained.

(Comparative Example 4)
The roughness of the surface of the cooling roll is the same size as the first uneven shape 1 and the fine uneven shape 2, the arithmetic average roughness Ra = 0.25 μm, the ten-point average roughness Rz = 3.3 μm, the convex portion number 675 / mm ² in the shape prepared those imparted, imparting the cooling roll surface shape in the first layer 3 side is placed in contact, a film by sandwiching the molten resin to nip the cooling roll did. Other parts were the same as in Example 1, and a film for packaging material 5 was obtained.

(Comparative Example 5)
As another comparative example, a chill roll surface with no roughness was prepared, and a thermoplastic resin formulated with a lubricant and an antiblocking agent was prepared. The first layer 3 was prepared by adding 20000 ppm of inorganic particles (zeolite) having an average particle size of 5 μm to a thermoplastic resin and 100 ppm of erucic acid amide as an organic lubricant. The second layer 4 is formed by forming a film as a prescription in which 3000 ppm of inorganic particles (zeolite) having an average particle size of 5 μm and 100 ppm of erucamide as an organic lubricant are added to a thermoplastic resin. 5 was obtained.

<Evaluation>
The film 5 for packaging materials obtained in Examples 1 to 5 and Comparative Examples 1 to 5 was obtained by laminating a 12 μm thick biaxially stretched nylon film and a 15 μm thick biaxially stretched polyethylene terephthalate film by dry lamination. The packaging material 9 was obtained by laminating the material 7 and dry lamination. A polyester type was used as the adhesive, and after dry lamination, it was stored at 50 ° C. for 2 days.
In order to evaluate the performance of the packaging material film 5 and the packaging material 9 obtained in each of the examples and the comparative examples, the packaging material film 5 is evaluated for heat sealability, slipperiness evaluation, blocking resistance evaluation, and further packaging. With respect to the material 9, slip evaluation and blocking resistance evaluation were performed.

(Heat sealability evaluation)
The heat sealability was evaluated by using a heat sealer (TP-701-B) manufactured by Tester Sangyo Co., Ltd. with a seal pressure of 0.2 MPa, a seal time of 1 second, a seal width of 10 mm, a seal temperature of 130 ° C., and a packaging material. The uneven surfaces of the film 5 were stacked and sealed. The sealed film was cut into 15 mm width × 100 mm, the T-peel strength was measured using a tensile tester (AGS-500NX) manufactured by Shimadzu Corporation with a distance between chucks of 50 mm and a tensile speed of 300 mm / min. Strength. The seal strength of 10 [N / 15 mm] or higher was evaluated as “◯”, and the seal strength lower than 10 [N / 15 mm] was determined as “X”.

(Slip evaluation)
Slip evaluation is performed for packaging materials by the slope method that calculates the coefficient of static friction from the angle at which the weight starts to slip when the slope angle is gradually increased, using a sliding slope angle measuring device manufactured by Toyo Seiki Co., Ltd. The static friction coefficient between the uneven surfaces of the film 5 was evaluated. The weight used was a metal block of 30 mm width × 40 mm length × 30 mm height and a mass of 197 g.
The slipperiness evaluation regarding the film 5 for packaging materials was measured immediately after film formation and after 7 days, and the influence of change with time was confirmed. Moreover, the slipperiness evaluation regarding the packaging material 9 implemented the measurement immediately after aging after dry lamination, and after 7 days. As the evaluation results, “◯” indicates that the static friction coefficient is within the range of 0.20 to 0.90, and “x” indicates other cases.

(Evaluation of blocking resistance)
The blocking resistance evaluation for the packaging material film 5 was conducted after 10 sheets of packaging material film 5 were stacked and held for 2 days under a load of 0.3 MPa using a compression tester manufactured by Tester Sangyo Co., Ltd. The strength was measured. The blocking strength was measured by cutting the blocked film into a 30 mm width × 100 mm length so that only the range of 30 mm × 30 mm was blocked, making the distance between chucks 50 mm, and the pulling speed 300 mm / min, manufactured by Shimadzu Corporation Using a tensile tester (AGS-500NX), the shear peel strength was measured and taken as the blocking strength. Those having a blocking strength of 10 [N / 30 mm] or less were evaluated as “◯”, and those having a blocking strength of 10 [N / 15 mm] or more were evaluated as “X”. In addition, in the case where no blocking was observed, the shear peel strength was described as 0 in Table 1, and the determination was “◯”.

  The blocking resistance evaluation for the packaging material 9 was made by stacking 10 packaging materials 9 and holding the tester industry compression test device under a load of 0.3 MPa for 2 days in a 50 ° C. environment and then blocking strength. Was measured. The method for measuring the blocking strength is the same as the blocking resistance evaluation for the packaging material film 5. Although blocking was observed, those having a blocking strength of 20 [N / 15 mm] or less were rated as “◯”, and those exceeding 20 [N / 15 mm] as “X”. For those in which no blocking was observed, in Table 1, the measured value was described as “0”, and “◯” was determined.

(Comprehensive evaluation)
As a comprehensive judgment, the heat sealability evaluation, the slipperiness evaluation, the blocking resistance evaluation, and the slipperiness evaluation and the blocking resistance evaluation regarding the packaging material 9 are all evaluated as “◯”. A “◯” evaluation was given, and an evaluation of “×” was made even if there was at least one “×” determination.
(Evaluation results)
Table 1 shows the evaluation results of the packaging material film 5 and the packaging material 9 of each example and each comparative example.

In Examples 1-5, it became "(circle)" determination by all the items, and the packaging material 9 with favorable slipperiness, blocking resistance, and low-temperature heat-sealing property was able to be obtained.
On the other hand, in Comparative Example 1, the arithmetic average roughness Ra and the ten-point average roughness Rz of the first concavo-convex shape 1 are too large, and the number of convex shapes is 100 pieces / mm ² or less. Air was caught and the low-temperature heat seal strength was significantly reduced. Moreover, in the comparative example 2, the fine uneven | corrugated shape 2 became too small, and resulted in a slip property worsening. In the comparative example 3, the fine uneven | corrugated shape 2 became large too much, and it resulted in the slip property becoming too good. In Comparative Example 4, the first uneven shape 1 was made the same size as the fine uneven shape 2, resulting in insufficient blocking resistance. Furthermore, in Comparative Example 5, a lubricant and an anti-blocking agent were added instead of the uneven shape, but the lubricant gradually bleeds out, so it is unstable over time, and in particular, the slipperiness is insufficient immediately after the packaging material. became. Also, the blocking resistance was insufficient.

  From the above, if the present invention is used, it is possible to provide a film 5 for packaging material that has good slipperiness and blocking resistance in a processing step and has good low-temperature heat sealability without using a lubricant or an antiblocking agent. can do. Moreover, when it uses as the packaging material 9 and the package 30, the package 30 which has favorable slipperiness and blocking resistance can be provided.

1 First uneven shape 2 Fine uneven shape (second uneven shape)
3 First layer 4 Second layer 5 Packaging film 6 Adhesive layer 7 Base material 8 Functional layer 9 Packaging material 10 Standing pouch 12 Pouch surface 13 Pouch back surface 16 Pouring nozzle 17 Uncut line 18 Unsealing knob 19 Half cut Line 20 Bottom tape 21 Folded part ridge line 22 Left and right side seal parts 23 Bottom seal part 24 Outlet nozzle seal part 25 Outlet nozzle tip seal part 26 Embossed part 30 Packaging

Claims (5)

Having a sealant film with thermoplastic resin as the main resin,
A first concavo-convex shape formed on the entire surface of the sealant film, and a second concavo-convex shape formed on the first concavo-convex shape and having an average roughness smaller than that of the first concavo-convex shape, Prepared,
The surface of the sealant film has an arithmetic average roughness Ra of the first uneven shape of 0.5 μm to 2.0 μm, and a ten-point average roughness Rz of the first uneven shape of 4.0 μm to 12. 0 μm or less, the arithmetic mean roughness Ra of the second uneven shape is 0.15 μm or more and 0.35 μm or less,
The film for packaging materials, wherein the number of convex shapes of the first concavo-convex shape is 100 or more and 400 or less per 1 mm ² .   The film for packaging material according to claim 1, wherein the sealant film does not contain an antiblocking agent and a lubricant. A first sealant film comprising the sealant film according to claim 1 or 2,
A second sealant film laminated on the back surface of the first sealant film and having a thermoplastic resin as a main resin,
The thermoplastic resin constituting each of the sealant films is composed mainly of at least one of polyethylene or a derivative thereof,
The first sealant film has an average density of 0.910 g / cm ^{3 to} 0.920 g / cm ³ and a thickness of 5 μm to 30 μm.
The second sealant film, packaging film, wherein the average density of 0.925 g / cm ³ or more 0.940 g / cm ³ or less, and is 30μm or more 100μm or less thickness.   A packaging material comprising the packaging material film according to claim 3, wherein a base material layer is provided on a back surface side of the second sealant film.   A package using the packaging material according to claim 4.

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