JP7046624B2 - Manufacturing method of easy-to-tear packaging material - Google Patents

Description

The present invention also relates to a method for producing an easily tearable packaging material used for an easily openable packaging bag or the like, specifically, even when a laminated film having a base film having a plurality of fine through holes formed is obtained by laminating. The present invention relates to a method for producing an easily tearable packaging material capable of suppressing the occurrence of blocking.

Conventionally, various measures have been taken to facilitate opening of a packaging bag. As one of them, in a laminated film forming an easily openable packaging bag, it can be easily opened from an arbitrary edge of the sealing portion of the packaging bag by using a base film having a plurality of fine through holes formed therein. Laminated films are known.

For example, Patent Document 1 describes a laminated film having a thermoplastic stretched film layer having a band-shaped scar group, a thermoplastic film layer having fine scars on the entire surface (base film in the present invention), and a heat seal layer. A pillow-shaped easy-to-open packaging bag consisting of is described, consisting of a plurality of rows in which the band-shaped scars are located along the fold line and the notches are arranged so that the length direction crosses the fold line. Therefore, it is described that the stress concentration on the scars when the packaging bag is torn and opened is large and the packaging bag can be easily opened with a weak force of the fingers.

A laminated film having a base film having fine through holes is usually printed on the base film, provided with a print layer, and then formed with fine through holes penetrating the base film and the print layer. Then, it is obtained by laminating a base film and another film such as a barrier film or a sealant film. Laminating processing includes dry laminating in which a base film and another film are laminated via an adhesive, or an anchor coating agent is applied onto the base film to provide an anchor coat layer, and a polyethylene resin is provided on the anchor coat layer. Examples thereof include an extruded laminate in which a thermoplastic resin such as the above is melted and extruded into a film to be laminated.

However, in a laminated film having a base film having a plurality of fine through holes formed like this, since the fine through holes are formed in the base film, an adhesive or an anchor coating agent (hereinafter, collectively adhered). A phenomenon called strike-through may occur in which the agent (referred to as an agent or the like) passes through the fine through holes formed in the film and seeps out to the surface opposite to the adhesive surface (hereinafter referred to as the back surface). This strike-through phenomenon may cause inconveniences such as the exuded adhesive or the like filling the fine through holes to deteriorate the tearability, and the front and back surfaces of the laminated film wound in a roll shape are blocked.

Therefore, in order to prevent this strike-through, Patent Document 2 describes a laminated film in which a base film provided with fine pores to penetrate and an olefin film are bonded using a solvent-free laminated adhesive. In the laminated film, it is described that by using a solvent-free laminated adhesive as an adhesive for bonding the base film and the olefin film, it is possible to prevent the adhesive from seeping out to the back surface during the laminating process. ..

JP 2001-18991 Actual Kaihei 4-79636

By the way, the laminated film obtained by the laminating process usually promotes the curing of an adhesive or the like, and in order to obtain high adhesive strength, a film roll obtained by winding the laminated film into a roll is usually placed in an environment of 35 to 60 ° C. It is stored for about 1 to 4 days and subjected to aging treatment. This is no exception to the laminated film having a base film having fine through holes, and it is necessary to apply an aging treatment to the film roll of the laminated film in order to promote the curing of the adhesive and the like and increase the adhesive strength. .. However, in a film roll of a laminated film having a base film having fine through holes formed, the front and back surfaces of the laminated film (for example, a sealant film adjacent to the base film) adhere to each other after the aging treatment, and blocking occurs. There is a problem that it occurs.

As a countermeasure for this, for example, it is conceivable to rewind the film roll of the laminated film immediately after the laminating process and then perform the aging treatment. However, even if the rewinding is performed, the core portion of the film roll of the laminated film is not covered. The blocking problem could not be resolved.

The present invention has been made in view of such a problem, and when a film roll of a laminated film in which a base film having fine through holes is formed and another film are laminated by dry laminating, extrusion laminating, or the like is aged. It is an object of the present invention to provide a method for producing an easily tearable packaging material capable of suppressing the occurrence of blocking.

First, the present inventors investigated the cause of blocking occurring by subjecting a film roll of a laminated film having a base film having fine through holes formed to an aging treatment, and found that the strike-through of this adhesive or the like was found. It was found that it occurred in the aging process. That is, although there is almost no strike-through of the adhesive or the like at the laminating stage, the film roll of the laminated film is tightened due to thermal shrinkage of the laminated film in an environment of 35 to 60 ° C. in the aging treatment. It was found that the pressure caused the adhesive or the like to pass through the fine through holes and seep out to the back surface.

Therefore, as a result of diligent studies based on the consideration that suppressing the winding of the film roll of the laminated film in the aging treatment is effective in suppressing blocking, the present inventors conducted the aging treatment at 15 ° C. By applying in an environment of more than 35 ° C. [preferably in a normal temperature environment (20 to 30 ° C.)], the thermal shrinkage of the laminated film is suppressed, and the adhesive or the like is prevented from seeping out to the back surface through the fine through holes. It has been found that it is possible to suppress the occurrence of blocking in the film roll of the laminated film. Further, as an adhesive used for dry laminating and extrusion laminating, a two-component curable polyurethane adhesive having excellent quick-curing properties, which comprises a main agent containing a polyester polyol as a main component and a curing agent containing an aromatic polyisocyanate as a main component. Alternatively, it has been found that by using an anchor coating agent, practical adhesive strength can be obtained even in a short-term aging treatment in a normal temperature environment.

According to the present invention
(1) An anchor coating agent is applied onto a base film having a plurality of fine through holes to provide an anchor coating layer, and at least one thermoplastic resin layer is extruded onto the anchor coating layer to obtain the thermoplastic resin. If necessary, another layer is laminated on the resin layer by extrusion laminating or dry laminating to form a laminated film, and the laminated film is wound into a roll on a film roll at a temperature of 15 ° C. or higher and lower than 35 ° C. for 12 hours or longer. A method for producing an easily tearable packaging material, which is characterized by being subjected to an aging treatment of the above, is provided.
(2) The anchor coating agent is a two-component curable polyurethane anchor coating agent containing a polyester polyol as a main component and an aromatic polyisocyanate as a main component (1). The method for manufacturing an easily openable packaging material described in the above is provided.
(3) The method for producing an easily tearable packaging material according to (1) or (2), wherein the other layer has a sealant layer made of a thermoplastic resin having a heat-sealing property is provided.
(4) The other layer has a barrier layer and a sealant layer made of a thermoplastic resin having a heat-sealing property, and the barrier layer is arranged on the thermoplastic resin (1). ) Or the method for producing the easily tearable packaging material according to (2).
(5) The thermoplastic resin layer is made of linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, ethylene-α-olefin copolymer, polypropylene, propylene-α-olefin copolymer, or ethylene-vinyl acetate copolymer. The method for producing an easily tearable packaging material according to (1) or (2), which is a sealant layer composed of one or more selected from the above, is provided.
(6) An adhesive is applied on a base film having a plurality of fine through holes to provide an adhesive layer, and another layer is laminated on the adhesive layer to form a laminated film, and the laminated film is rolled. Provided is a method for producing an easily tearable packaging material, which comprises subjecting a film roll wound up to an aging treatment at a temperature of 15 ° C. or higher and lower than 35 ° C. for 12 hours or longer.
(7) Described in (6), the adhesive is a two-component curable polyurethane adhesive containing a polyester polyol as a main component and an aromatic polyisocyanate as a main component. Easy-to-open packaging material manufacturing method is provided,
(8) The method for producing an easily tearable packaging material according to (6) or (7), wherein the other layer has a sealant layer made of a thermoplastic resin having a heat-sealing property.
(9) The other layer has a barrier layer and a sealant layer made of a thermoplastic resin having a heat-sealing property, and the barrier layer is arranged on the adhesive layer (6). Alternatively, the method for producing an easily tearable packaging material according to (7) is provided.

In the method for producing an easily tearable packaging material of the present invention, it is possible to prevent the adhesive or the like from seeping out to the back surface through the fine through holes, so that the exuded adhesive or the like fills the fine through holes and has tearability. It is possible to suppress troubles such as deterioration and blocking of the front and back of the laminated film wound on the roll. Further, by using a two-component curable adhesive or the like having excellent quick-curing properties, practical adhesive strength can be obtained in a relatively short time even in an aging treatment in a normal temperature environment, and the productivity is excellent.

It is an enlarged sectional view of the easily tearable packaging material which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows the manufacturing method of the easily tearable packaging material which concerns on Embodiment 1 of this invention. It is an enlarged sectional view of the easily tearable packaging material which concerns on Embodiment 2 of this invention. It is an enlarged sectional view of the easily tearable packaging material which concerns on Embodiment 3 of this invention. It is a schematic diagram which shows the manufacturing method of the easily tearable packaging material which concerns on Embodiment 3 of this invention. It is an enlarged sectional view of the easily tearable packaging material which concerns on Embodiment 4 of this invention.

Hereinafter, the method for producing the easily tearable packaging material of the present invention will be described with reference to the drawings. The method for producing the easily tearable packaging material of the present invention is not limited to the following embodiments.

[Easy-tearable packaging material (Embodiment 1)]
FIG. 1 is an enlarged cross-sectional view of the easily tearable packaging material according to the first embodiment of the present invention. The easily tearable packaging material of the present invention shown in FIG. 1 has a base film 2 on which a plurality of fine through holes are formed, an anchor coat layer 3, a thermoplastic resin layer 4, and a sealant layer 5 in this order. It is a laminated film 1. In addition, another layer may be provided between each layer as long as the object of this invention can be achieved.

(Base film)
The base film used in the present invention is a thermoplastic resin film in which a plurality of fine through holes are formed for the purpose of easy tearability. Examples of the thermoplastic resin film include a polyamide film, a polyester film, a polypropylene film, and the like, and these may be laminated. Further, the thermoplastic resin film may be a uniaxial or biaxially stretched film. The thickness of the base film may be appropriately designed according to the packaging application, and is not particularly limited, but is, for example, 10 to 100 μm. The thickness of the base film is preferably 10 to 60 μm, more preferably 10 to 40 μm. If the thickness of the base film is thinner than the above range, the mechanical strength is small, and if it is thicker than the above range, the tearability may be deteriorated.

Further, a plurality of fine through holes are formed on the entire surface or a part of the base film. The opening diameter and density of the fine through holes may be appropriately designed depending on the type and thickness of the film, and are not particularly limited. For example, the average opening diameter of each through hole is 0.1 to 100 μm. The average distribution density is 1 × 10 ² to 3 × 10 ⁵ pieces / cm ² . The average opening diameter is preferably 0.5 to 50 μm, more preferably 0.5 to 20 μm. The average distribution density is preferably 5 × 10 ² to 1 × 10 ⁵ pieces / cm ² , and more preferably 1 × 10 ³ to 5 × 10 ⁴ pieces / cm ² . For the average distribution density of fine through holes, the number of fine through holes in five regions of 50 μm × 50 μm at an arbitrary position on the base film was counted using a microscope, and the obtained values were averaged to 1 cm ² . Obtained by converting to the number of pieces per unit. As a method for forming the fine through holes, a conventionally known method can be adopted and is not particularly limited. For example, abrasive grains having an adjusted particle size are fixed on the circumferential surface of the metal roll with a binder. A method of applying the film by pressing it while running between this roll and a metal receiving roll, a method of pressing the film with a roll in which a large number of fine needles are embedded, and a method of pressing a roll having many fine blades formed on the film. The method and the like can be mentioned. When printing is performed on the base film, fine through holes may be formed through the base film and the print layer after the print layer is provided on the base film. The base film allows not only through holes but also fine non-through holes (for example, an average opening diameter of 0.1 to 100 μm) to coexist.

(Anchor coat layer)
The anchor coat layer is a layer that enhances the adhesiveness between the base film and the thermoplastic resin layer extruded onto the anchor coat layer, and the anchor coat layer is provided on the base film. As the anchor coating agent, a conventionally known reaction-curing adhesive can be used, and examples thereof include a solvent-type one-component curing type and two-component curing type anchor coating agent. Among these, the solvent type two-component curing type anchor coating agent is preferable because the reaction mechanism is more stable than that of the one-component curing type. Examples of the type of anchor coating agent include polyurethane-based anchor coating agents, polyethyleneimine-based anchor coating agents, and polybutadiene-based anchor coating agents. The thickness of the anchor coat layer is not particularly limited, but is preferably 0.01 to 3 μm, more preferably 0.05 to 1 μm, for example. If the thickness is thinner than the above range, the adhesive strength is low and the effect may not be exhibited. If the thickness is thicker than the above range, the cost will be increased and the effect of improving the adhesiveness will not be seen only by increasing the thickness.

The anchor coating agent used in the present invention is a two-component curable polyurethane anchor coating agent composed of a polyol component as a main agent and an isocyanate component as a curing agent because it is easy to control the adhesiveness and elastic modulus. Is preferable. Examples of the polyol component include polyurethane polyols, polyester polyols, polycarbonate polyols, polyether polyols, acrylic polyols, polyolefin polyols and the like, and one or a combination of two or more selected from these can be used. .. Examples of the isocyanate component include aliphatic polyisocyanates, aromatic polyisocyanates, aromatic aliphatic polyisocyanates, alicyclic polyisocyanates, and the like, and one selected from these, or a combination of two or more thereof is used. be able to. Among these, it is preferable that the main agent is a two-component curable polyurethane anchor coating agent containing a polyester polyol as a main component and the curing agent containing an aromatic polyisocyanate as a main component. A two-component curable polyurethane anchor coating agent consisting of a main agent containing a polyester polyol as a main component and a curing agent containing an aromatic polyisocyanate as a main component has excellent quick-curing properties and can be used in a short time even in an aging treatment in a normal temperature environment. Since practical adhesive strength can be obtained, strike-through of the anchor coating agent when extruding and laminating a base film having fine through holes and another layer such as a sealant layer is suppressed, and the film roll Blocking can be suppressed.

(Thermoplastic resin layer)
The thermoplastic resin layer is a layer for extruding and laminating a base film and another layer such as a sealant layer, and is formed by extruding onto an anchor coat layer. The thermoplastic resin layer is preferably made of a polyolefin resin because it has excellent suitability for extrusion laminating, and the polyolefin resin includes an ethylene resin such as linear low density polyethylene and low density polyethylene, polypropylene, and propylene-α. Examples thereof include propylene-based resins such as olefin copolymers. The thickness of the thermoplastic resin layer may be appropriately designed according to the intended use and is not particularly limited, but is preferably 5 to 60 μm, more preferably 10 to 40 μm, for example. Further, the thermoplastic resin layer may have a multi-layer structure.

(Sealant layer)
The sealant layer is formed of a thermoplastic resin having a heat-sealing property. Examples of the thermoplastic resin having heat-sealing properties include linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, ethylene-α-olefin copolymer, polypropylene, propylene-α-olefin copolymer, and ethylene-vinyl acetate. Examples thereof include a copolymer and the like, and one kind selected from these, or two or more kinds can be used in combination. The thickness of the sealant film may be appropriately designed according to the packaging application and is not particularly limited, but is preferably, for example, 5 to 200 μm, more preferably 10 to 100 μm, and 10 to 50 μm. It is particularly preferable to have. If the thickness of the sealant film is thinner than the above range, the heat seal strength of the sealant film is insufficient, and if it is thicker than the above range, the tearability may be deteriorated. Further, the sealant layer may have a multi-layer structure.

Although the thermoplastic resin layer has been described as a layer in which a base film and another layer such as a sealant layer are extruded and laminated, the thermoplastic resin layer is formed from a resin having a heat-sealing property, and the thermoplastic resin layer is formed. It may be used as a sealant layer. Examples of the heat-sealing resin include linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, ethylene-α-olefin copolymer, polypropylene, propylene-α-olefin copolymer, and ethylene-vinyl acetate copolymer. Coalescence and the like can be mentioned, and one kind selected from these, or two or more kinds can be used in combination.

[Manufacturing method of easily tearable packaging material (Embodiment 1)]
In the method for producing an easily tearable packaging material according to the first embodiment of the present invention, an anchor coating agent is applied on a base film having a plurality of fine through holes to provide an anchor coat layer, and the anchor coat layer is provided on the anchor coat layer. At least one thermoplastic resin layer is extruded, and if necessary, the other layers are laminated by extrusion laminating or dry laminating to form a laminated film, and the laminated film is wound into a roll on a film roll at 15 ° C. or higher and 35 ° C. It is characterized in that it is subjected to an aging treatment for 12 hours or more at a temperature of less than 12 hours. According to the production method of the present invention, a thermoplastic resin layer is extruded onto an anchor coat layer provided on a base film having a plurality of fine through holes to form a laminated film, and then the temperature is relatively close to room temperature. By applying the aging treatment underneath, it is possible to prevent the film roll from being thermally shrunk and the roll to be wound, and the pressure thereof to prevent the anchor coating agent from seeping out to the back surface through the fine through holes. The extrusion laminating in the present invention means that a thermoplastic resin is melted and extruded into a film to be laminated on a base material, and any method such as single laminating, sandwich laminating, tandem laminating, coextruding laminating and the like is used. Can also be adopted. Further, the dry laminating in the present invention means laminating a base material and another layer via an adhesive layer.

In the aging treatment, it is necessary to accelerate the curing of the anchor coating agent at a temperature at which the base film does not heat shrink, so that the temperature of the aging treatment is 15 ° C. or higher and lower than 35 ° C. The temperature of the aging treatment is preferably 17 ° C. or higher and lower than 32 ° C., and more preferably 20 ° C. or higher and lower than 30 ° C. If the temperature is lower than 15 ° C., the curing promoting effect of the anchor coating agent is not sufficient, and the adhesive strength between the base film and the thermoplastic resin layer may be insufficient. If the temperature is 35 ° C. or higher, the film roll may be wound by heat shrinkage, pass through the fine through holes before the anchor coating agent is cured, and the anchor coating agent may seep out to the back surface and cause blocking. The aging treatment time is 12 hours or more, preferably 18 hours or more, and more preferably 1 day (24 hours) or more. In the aging treatment, if the film roll is exposed to an environment above the upper limit temperature at a time of less than 12 hours, blocking may occur on the film roll, but at a time of less than 12 hours, it is exposed to an environment below the lower limit temperature. If this is the case, there is a risk that the adhesive strength will be insufficient, but there is little risk that blocking will occur on the film roll. Therefore, when the aging treatment is exposed to an environment below the lower limit temperature when the aging treatment is less than 12 hours, the aging treatment at the above temperature may be cumulatively 12 hours or more.

Next, a method for producing the easy-to-open packaging material according to the first embodiment of the present invention will be described with reference to FIG. In FIG. 2, reference numeral MR1 is a roll of raw fabric on which a base film having a plurality of fine through holes is formed, and reference numeral MR2 is a roll of raw fabric on which a sealant film (sealant layer) is wound. Further, the reference numeral SR is a film roll (before aging treatment) in which the manufactured laminated film is wound.

First, the sealant film is unwound from the raw roll MR2 and supplied to the laminating apparatus RP. On the other hand, when the base film on which a plurality of fine through holes are formed is unwound from the raw fabric roll MR1, the surface treatment is performed by the surface treatment device CP as necessary. Examples of this surface treatment include corona discharge treatment and plasma treatment, and appropriate treatment may be performed according to the base film and the anchor coating agent.

If necessary, the base film surface-treated by the surface treatment device CP is supplied to the anchor coating agent coating device GR, and the solvent-diluted anchor coating agent is applied. The solvent used for diluting the anchor coating agent is not particularly limited, but is not particularly limited, but is limited to esters such as ethyl acetate, butyl acetate and cellosolve acetate, ketones such as acetone, methyl ethyl ketone, isobutyl ketone and cyclohexanone, tetrahydrofuran and dioxane. Ethers such as ethers, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as methylene chloride and ethylene chloride, alcohols such as methanol, ethanol and isopropanol, water and the like, which are selected from these. One type or a combination of two or more types can be used.

The base film coated with the anchor coating agent diluted with the solvent is supplied to the drying device DP. In this drying device DP, the solvent is removed by heating the base film, and an anchor coat layer is formed on the base film. The drying temperature in the drying device DP is adjusted to a temperature at which the base film does not heat shrink and the solvent volatilizes.

The base film that has passed through the drying device DP is supplied to the laminating device RP, and is laminated and adhered to the sealant film. Specifically, in the laminating apparatus RP, a molten resin is extruded into a film from a single-layer or multi-layered T-die between the surface of the base film on which the anchor coat layer is formed and the sealant film, and the resin is extruded. By cooling and solidifying to form a thermoplastic resin layer and laminating, a laminated film in which the base film and the sealant film are adhered by the thermoplastic resin layer is obtained. This laminated film is wound into a roll shape in consideration of handleability and the like, and becomes a film roll SR.

Next, the obtained film roll SR is conveyed to a conventionally known dryer or an aging chamber (not shown) and subjected to an aging treatment under the above-mentioned conditions to obtain a film roll without blocking.

Although the sandwich laminating method has been described here as an example of the method for producing the easily tearable packaging material according to the first embodiment of the present invention, for example, the thermoplastic resin is formed on the surface of the base film on which the anchor coat layer is formed. The molten resin that forms the layer is extruded into a film, and the resin is cooled and solidified to form a thermoplastic resin layer on the anchor coat layer of the base film, and then a sealant layer is formed on the thermoplastic resin layer. A tandem laminate that extrudes a molten resin into a film and cools and solidifies the resin to form a sealant layer on the thermoplastic resin layer. A thermoplastic resin layer is formed on the surface of the base film on which the anchor coat layer is formed. The resin to be used and the resin forming the sealant layer may be supplied to separate extruders and simultaneously extruded onto a film, and a coextrusion laminate may be used in which two types of resin layers are simultaneously laminated on a base film.

Further, the thermoplastic resin layer is formed of a resin having a heat-sealing property, the thermoplastic resin layer is used as a sealant layer, and a base film having a plurality of fine through holes formed therein, an anchor coat layer, and a sealant layer are used. In the case of laminated films (not shown) having in order, a single laminate may be obtained in which a thermoplastic resin having a heat-sealing property is extruded into a film and laminated on the surface of the base film on which the anchor coat layer is formed.

[Easy-tearable packaging material (Embodiment 2)]
FIG. 3 is an enlarged cross-sectional view of the easily tearable packaging material according to the second embodiment of the present invention. The easily tearable packaging material of the present invention shown in FIG. 3 includes a base film 12 on which a plurality of fine through holes are formed, a first anchor coat layer 13A, a thermoplastic resin layer 14, a barrier layer 16, and a first layer. The laminated film 11 has 2 anchor coat layers 13B and a sealant layer 15 in this order.

(Barrier layer)
The barrier layer is a layer that prevents gas permeation such as water vapor and oxygen, and is usually formed so as to be located between the base film and the sealant layer. The barrier layer is not particularly limited, but for example, a metal oxide vapor deposition film in which a metal foil such as an aluminum foil, a metal oxide vapor deposition layer such as silicon oxide or aluminum oxide is provided on a thermoplastic resin film, or aluminum. A metal vapor deposition film in which a metal vapor deposition layer such as is provided on a thermoplastic resin film, a gas barrier film made of a gas barrier resin such as an ethylene-vinyl alcohol copolymer, and a gas barrier film coated with polyvinylidene chloride or the like on a thermoplastic resin film. Etc., and these may be laminated. The thickness of the barrier layer may be appropriately selected depending on the packaging application, and is not particularly limited, but is, for example, 5 to 100 μm. The thickness of the barrier layer is preferably 5 to 60 μm, more preferably 5 to 30 μm.

In the easily tearable packaging material according to the second embodiment of the present invention, for example, an anchor coating agent is applied onto a base film having a plurality of fine through holes to provide a first anchor coat layer, and the base film is provided with a first anchor coat layer. A molten resin is extruded into a film between the first anchor coat layer and the barrier layer to form a thermoplastic resin layer for extrusion laminating, and then an anchor coating agent is applied onto the barrier layer to apply a second anchor. A coat layer is provided, and a thermoplastic resin having a heat seal property is extruded onto the second anchor coat layer of the barrier layer to laminate a sealant layer to form a laminated film, and the laminated film is wound into a roll on a film roll. The aging treatment may be performed at a temperature of ° C. or higher and lower than 35 ° C. for 12 hours or longer. Here, as a method for producing an easily openable packaging material according to the second embodiment of the present invention, a single laminate in which a sealant layer is extruded and laminated is exemplified, but a molten resin is used between the barrier layer and the sealant layer. It may be extruded into a film and sandwich-laminated, or an adhesive may be applied on the barrier layer to provide an adhesive layer, and the adhesive layer and the sealant layer may be dry-laminated.

[Easy-tearable packaging material (Embodiment 3)]
FIG. 4 is an enlarged cross-sectional view of the easily tearable packaging material according to the third embodiment of the present invention. The easily tearable packaging material of the present invention shown in FIG. 4 is a laminated film having a base film 22 on which a plurality of fine through holes are formed, an adhesive layer 23, and a sealant layer 25 in this order. It is also possible to provide another layer between the layers as long as the object of the present invention can be achieved.

(Adhesive layer)
The adhesive layer is a layer for dry laminating a base film and another layer such as a sealant layer, and is provided on the base film. As the adhesive layer, a conventionally known reaction-curable adhesive can be used, and examples thereof include a solvent-type one-component curable adhesive and a two-component curable adhesive. Among these, the solvent type two-component curable adhesive is preferable because the reaction mechanism is more stable than that of the one-component curable type. The types of adhesives include polyurethane adhesives, polyisocyanate adhesives, polyester adhesives, epoxy adhesives, acid-modified polyolefin adhesives, chlorinated polyolefin adhesives, acrylic adhesives, and polybutadiene adhesives. Examples include agents. The thickness of the adhesive layer is not particularly limited, but is preferably 0.01 to 10 μm, more preferably 0.1 to 5 μm, and even more preferably 0.5 to 3 μm, for example. ..

The adhesive used in the present invention is preferably a two-component curable polyurethane adhesive composed of a polyol component as a main agent and an isocyanate component as a curing agent because it is easy to control the adhesiveness and elastic modulus. .. Examples of the polyol component include polyurethane polyols, polyester polyols, polycarbonate polyols, polyether polyols, acrylic polyols, polyolefin polyols and the like, and one or a combination of two or more selected from these can be used. .. Examples of the isocyanate component include aliphatic polyisocyanates, aromatic polyisocyanates, aromatic aliphatic polyisocyanates, alicyclic polyisocyanates, and the like, and one selected from these, or a combination of two or more thereof is used. be able to. Among these, it is preferable that the main agent is a two-component curable polyurethane adhesive containing a polyester polyol as a main component and the curing agent containing an aromatic polyisocyanate as a main component. A two-component curable polyurethane adhesive consisting of a main agent containing a polyester polyol as a main component and a curing agent containing an aromatic polyisocyanate as a main component has excellent quick-curing properties and is practical in a short time even in an aging treatment in a normal temperature environment. Since it is possible to obtain a specific adhesive strength, it is possible to suppress strike-through of the adhesive and suppress blocking of the film roll even when the base film having fine through holes and the sealant film are dry-laminated. ..

[Manufacturing method of easily tearable packaging material (Embodiment 3)]
In the method for producing an easily tearable packaging material according to the third embodiment of the present invention, an adhesive is applied to a base film on which a plurality of fine through holes are formed to provide an adhesive layer, and a sealant layer or the like is provided on the adhesive layer. Another layer is laminated to form a laminated film, and the film roll obtained by winding the laminated film into a roll is subjected to an aging treatment at a temperature of 15 ° C. or higher and lower than 35 ° C. for 12 hours or longer. The preferable conditions such as temperature and time in the aging treatment are as described above.

Next, a method for producing the easily tearable packaging material according to the third embodiment of the present invention will be described with reference to FIG. In FIG. 5, reference numeral MR1 is a roll of raw fabric on which a base film having a plurality of fine through holes is formed, and reference numeral MR2 is a roll of raw fabric on which a sealant film (sealant layer) is wound. Further, the reference numeral SR is a film roll (before aging treatment) in which the manufactured laminated film is wound.

First, the sealant film is unwound from the raw roll MR2 and supplied to the laminating apparatus RP. On the other hand, when the base film on which a plurality of fine through holes are formed is unwound from the raw fabric roll MR1, the surface treatment is performed by the surface treatment device CP as necessary. The details of the surface treatment are as described above.

If necessary, the base film surface-treated by the surface treatment device CP is supplied to the adhesive application device GR, and the adhesive diluted with the solvent is applied. Details of the solvent used to dilute the adhesive are as described above.

The base film coated with the adhesive diluted with the solvent is supplied to the drying device DP. In this drying device DP, the solvent is removed by heating the base film, and an adhesive layer is formed on the base film. The drying temperature in the drying device DP is adjusted to a temperature at which the base film does not shrink and the solvent volatilizes.

The base film that has passed through the drying device DP is supplied to the laminating device RP, and is laminated and adhered to the sealant film. Specifically, in the laminating apparatus RP, the base film and the sealant film were adhered by the adhesive layer by applying pressure while the surface on the base film on which the adhesive layer was formed and the sealant film were combined. A laminated film is formed. This laminated film is wound into a roll shape in consideration of handleability and the like, and becomes a film roll SR.

Next, the film roll SR of the obtained laminated film is conveyed to a conventionally known dryer or an aging chamber (not shown) and subjected to an aging treatment under the above-mentioned conditions to obtain a film roll without blocking. ..

[Easy-tearable packaging material (Embodiment 4)]
FIG. 6 is an enlarged cross-sectional view of the easily tearable packaging material according to the fourth embodiment of the present invention. The easily tearable packaging material of the present invention shown in FIG. 6 includes a base film 32 having a plurality of fine through holes, a first adhesive layer 33A, a barrier layer 36, a second adhesive layer 33B, and a sealant layer. It is a laminated film having 35 in this order.

In the easily tearable packaging material according to the fourth embodiment of the present invention, for example, an adhesive is applied onto a base film having a plurality of fine through holes to provide a first adhesive layer, and the first adhesive layer is provided on the first adhesive layer. The barrier layer is laminated and dry-laminated, then an adhesive is applied to the surface of the barrier layer opposite to the base film side to provide a second adhesive layer, and the sealant layer is laminated on the second adhesive layer to dry. The laminated film may be laminated, and the film roll obtained by winding the laminated film into a roll may be subjected to an aging treatment at a temperature of 15 ° C. or higher and lower than 35 ° C. for 12 hours or longer. Here, as a method for producing an easily openable packaging material according to the fourth embodiment of the present invention, a method of dry laminating a sealant layer is exemplified, but a melted resin is formed into a film between the barrier layer and the sealant layer. It may be extruded into a sandwich laminate, or it may be a single laminate in which a sealant layer is extruded and laminated on a barrier layer.

Hereinafter, the production method of the present invention will be described in more detail with reference to Examples.
The following raw materials were used.
<Base film with multiple fine through holes formed>
-PET film [thickness: 12 μm, product name: E5100 (manufactured by Toyobo), average opening diameter of fine through holes: 13 μm, average distribution density: 13800 pieces / cm ² ]
<Anchor coat layer>
-Anchor coating agent A [Main agent: EL-541 (polyester polyol), curing agent: CAT-70H (aromatic polyisocyanate), manufactured by Toyo Morton Co., Ltd.]
-Anchor coating agent B [Main agent: EL-541 (polyester polyol), curing agent: CAT-RT90 (aliphatic polyisocyanate), manufactured by Toyo Morton Co., Ltd.]
<Thermoplastic resin layer>
-Low density polyethylene A [Density: 920 g / cm ³ , MFR: 7 g / 10 minutes, melting point: 108 ° C]
<Barrier layer>
-Aluminum foil [thickness: 9 μm]
<Sealant layer>
Low-density polyethylene B [Density: 920 g / cm ³ , MFR: 7 g / 10 minutes, melting point: 105 ° C]

[Example 1]
Anchor coating agent A is applied and dried on the surface of the PET film, a first anchor coating layer (thickness: 0.5 μm) is provided on the surface of the PET film, and between the first anchor coating layer of the PET film and the aluminum foil. A molten resin made of low-density polyethylene A extruded from a T-die was extruded into a film to form a thermoplastic resin layer (thickness: 20 μm) and extruded and laminated. Next, the anchor coating agent A is applied and dried on the aluminum foil, a second anchor coating layer (thickness: 0.5 μm) is provided, and a molten resin made of low-density polyethylene B is formed into a film on the second anchor coating layer. The sealant layer (thickness: 25 μm) was laminated to obtain a laminated film. Then, a film roll (length: 1000 m) obtained by winding the obtained laminated film into a roll shape was subjected to an aging treatment in an environment of 25 ° C. for 1 day. Table 1 shows the results of blocking evaluation on the film roll after the aging treatment.

[Comparative Example 1]
Anchor coating agent B is applied and dried on the surface of the PET film, a first anchor coating layer (thickness: 0.5 μm) is provided on the surface of the PET film, and between the first anchor coating layer of the PET film and the aluminum foil. A molten resin made of low-density polyethylene A extruded from a die was extruded into a film to form a thermoplastic resin layer (thickness: 20 μm) and extruded and laminated. Next, the anchor coating agent B is applied and dried on the aluminum foil, a second anchor coating layer (thickness: 0.5 μm) is provided, and a molten resin made of low-density polyethylene B is formed into a film on the second anchor coating layer. The sealant layer (thickness: 25 μm) was laminated to obtain a laminated film. Then, a film roll (length: 1000 m) obtained by winding the obtained laminated film into a roll shape was subjected to an aging treatment in an environment of 35 ° C. for 1 day. Table 1 shows the results of blocking evaluation on the film roll after the aging treatment.

[Comparative Example 2]
After obtaining a film roll (length: 1000 m) under the same conditions as in Comparative Example 1, the film roll was rewound and then aged in an environment of 35 ° C. for 1 day. Table 1 shows the results of blocking evaluation on the film roll after the aging treatment.

As shown in Table 1, a two-component curable polyurethane anchor coating agent consisting of a main agent containing a polyester polyol as a main component and a curing agent containing an aromatic polyisocyanate as a main component was used in an environment of 25 ° C. In the easily tearable packaging material of Example 1, which was aged for 24 hours, practical adhesive strength was obtained by curing the anchor coating agent, and the film roll was unwound from the outer part to the core part. The results showed that no blocking occurred.

On the other hand, as shown in Table 1, a two-component curable polyurethane anchor coating agent consisting of a main agent containing a polyester polyol as a main component and a curing agent containing an aliphatic polyisocyanate as a main component was used in an environment of 35 ° C. Although the easily tearable packaging material of Comparative Example 1 which had been aged for 24 hours underneath obtained practical adhesive strength due to the curing of the anchor coating agent, the film roll was unwound from the outer part to the core part. The result that blocking occurs is shown up to. Further, in the easily tearable packaging material of Comparative Example 2 which was rewound immediately after the production of the film roll, no blocking was observed in the outer winding portion when the film roll was unwound, but blocking was observed in the winding core portion. The results that occur are shown.

1, 11, 21, 31: Laminated film 2, 12, 22, 32: Base film 3, 13A, 13B: Anchor coat layer 23, 33A, 33B: Adhesive layer 4, 14: Thermoplastic resin layer 5, 15, 25, 35: Sealant layer 16, 36: Barrier layer

Claims (7)

A two-component curable polyurethane anchor coating agent containing a polyester polyol as a main component and an aromatic polyisocyanate as a main component is applied onto a base film on which a plurality of fine through holes are formed. An anchor coat layer is provided, and at least one thermoplastic resin layer is extruded onto the anchor coat layer to form a laminated film, and the laminated film is wound into a roll on a film roll having a temperature of 15 ° C. or higher. A method for producing an easily tearable packaging material, which comprises subjecting an aging treatment to a temperature of less than ° C. for 12 hours or more. The thermoplastic resin layer is selected from linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, ethylene-α-olefin copolymer, polypropylene, propylene-α-olefin copolymer, and ethylene-vinyl acetate copolymer. The method for producing an easily tearable packaging material according to claim 1, wherein the sealant layer is composed of one or more kinds. A two-component curable polyurethane anchor coating agent containing a polyester polyol as a main component and an aromatic polyisocyanate as a main component is applied onto a base film on which a plurality of fine through holes are formed. An anchor coat layer is provided, at least one thermoplastic resin layer is extruded onto the anchor coat layer, and a sealant layer made of a thermoplastic resin having a heat seal property is laminated on the thermoplastic resin layer by extrusion laminating or dry laminating. A method for producing an easily tearable packaging material, which comprises subjecting a laminated film to a laminated film and subjecting the film roll, which is wound into a roll, to an aging treatment at a temperature of 15 ° C. or higher and lower than 35 ° C. for 12 hours or longer. A two-component curable polyurethane anchor coating agent containing a polyester polyol as a main component and an aromatic polyisocyanate as a main component is applied onto a base film on which a plurality of fine through holes are formed. An anchor coat layer is provided, at least one thermoplastic resin layer is extruded on the anchor coat layer, a barrier layer is laminated on the thermoplastic resin layer by extrusion laminating or dry laminating, and a heat seal is applied on the barrier layer. A sealant layer made of a thermoplastic resin having a property is laminated by extrusion laminating or dry laminating to form a laminated film, and the laminated film is wound into a roll on a film roll at a temperature of 15 ° C. or higher and lower than 35 ° C. for 12 hours or longer. A method for producing an easily tearable packaging material, which comprises subjecting it to an aging treatment. A two-component curable polyurethane adhesive containing polyester polyol as the main component and aromatic polyisocyanate as the main component is applied and adhered to the base film on which a plurality of fine through holes are formed. A layer is provided, and another layer is laminated on the adhesive layer to form a laminated film, and the film roll obtained by winding the laminated film into a roll is subjected to an aging treatment at a temperature of 15 ° C. or higher and lower than 35 ° C. for 12 hours or longer. A method for producing an easily tearable packaging material. The method for producing an easily tearable packaging material according to claim 5 , wherein the other layer has a sealant layer made of a thermoplastic resin having a heat-sealing property. The fifth aspect of the present invention, wherein the other layer has a barrier layer and a sealant layer made of a thermoplastic resin having a heat-sealing property, and the barrier layer is arranged on the adhesive layer. A method for manufacturing an easily tearable packaging material.

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