KR20230125173A - Laminate and its manufacturing method, spout-attached pouch and its manufacturing method, packaging material, packaging bag and packaging body - Google Patents

Abstract

상기 식 (A) 중, ΔL^* 는, 히트 시일 조건에서 가열 및 가압하기 전과 후의 명도의 차를 나타내고, Δa^* 및 Δb^* 는, 양방에서, 히트 시일 조건에서 가열 및 가압하기 전과 후의 색상 및 채도의 차를 나타낸다.A laminate 300 comprising a substrate film 10, an adhesive layer 30, and a sealant film 20 in this order, and having a printing surface 52 of an electrostatic ink composition bonded to the adhesive layer 30. ), the adhesive layer 30 is composed of at least one of an adhesive composition containing a polyol, a polyisocyanate and an epoxy compound and a cured product thereof, and sealant film 20 on the printing surface 52 is sealed under a predetermined heat sealing condition. A layered product 300 having a color difference (ΔE) determined by the following formula (A) before and after heating and pressurization in , is less than 3.0.

In the above formula (A), ΔL ^* represents the difference in lightness before and after heating and pressurization under heat-seal conditions, and Δa ^* and Δb ^* are both the hue and chroma before and after heating and pressurization under heat-seal conditions. represents the difference between

Description

Laminate and its manufacturing method, spout-attached pouch and its manufacturing method, packaging material, packaging bag and packaging body

The present disclosure relates to a laminate and a method for manufacturing the same, a pouch with a spout and a method for manufacturing the same, a packaging material, a packaging bag, and a packaging body.

BACKGROUND OF THE INVENTION [0002] A packaging bag is known which seals and preserves to-be-packaged objects such as beverages and foodstuffs. As a packaging bag, a package using a thin film or sheet is used. Various types of information such as product, brand, and manufacturer are printed on such a packaging bag. As a means of such printing, a digital printer using an electrostatic ink composition is known.

For example, in Patent Document 1, a primer resin is applied to a first flexible substrate such as a PET film to obtain a coated surface, and a digital printer (manufactured by HP, Indigo20000 digital printer for labels and packages) is used to obtain a coated surface. It is proposed to perform electrostatic printing and to apply a crosslinking composition. In this way, after performing a predetermined process, a technique for obtaining a packaging material by laminating a first flexible substrate coated with a predetermined component and a second flexible substrate has been proposed.

Further, a pouch with a spout is known as a packaging container for sealing and preserving to-be-packaged objects such as beverages and fluid foodstuffs. The spout in a pouch with a spout is attached to the pouch body by thermal welding with the sealant layer of the pouch body. In Patent Document 2, in order to realize good thermal welding between the spout in a pouch with a spout and the sealant layer of the pouch body, a spout composed of a resin integrally molded body containing an olefin resin and an ethylene-vinyl alcohol copolymer, respectively And, it is proposed to use a sealant layer composed of an olefinic resin film.

Japanese Unexamined Patent Publication No. 2018-530478 International Publication No. 2018/062126

Since digital printing using an electrostatic ink composition can be used in small lots, laminates subjected to digital printing are used for various packaging materials. However, it has been found that when a packaging bag or the like is produced using a laminate having a printing surface of an electrostatic ink composition by a digital printer, discoloration may occur depending on heat seal conditions.

Then, this indication provides the laminated body which can fully suppress generation|occurrence|production of discoloration which arises at the time of heat sealing, while having a printing surface by a digital printer, in one side surface. In addition, a packaging bag and a packaging body having a printed surface by a digital printer and sufficiently suppressed discoloration are provided.

Further, in a pouch with a spout as shown in Patent Document 2, it is required to weld the spout and the sealant layer of the pouch body while pressing under high temperature conditions to sufficiently strengthen the adhesion between the spout and the sealant layer. Here, since digital printing using an electrostatic ink composition can be used in small lots, laminates subjected to digital printing are used for various packaging materials. However, since an electrostatic ink layer composed of an electrostatic ink composition does not have sufficient heat resistance, when digital printing is performed on the pouch body of a pouch with a spout, the welded portion between the spout and the pouch body may change color.

Then, in one aspect, the present disclosure provides a laminate excellent in heat resistance while having an electrostatic ink layer composed of an electrostatic ink composition. In addition, a pouch with a spout that has an electrostatic ink layer composed of an electrostatic ink composition and can sufficiently suppress discoloration of a welded portion with the spout, a manufacturing method thereof, and a package are provided. In addition, a packaging material preferably used as a pouch main body of a pouch with a spout is provided.

Further, since digital printing using an electrostatic ink composition can be performed in small lots, digitally printed laminates are used as materials for various packaging bags. However, the electrostatic ink layer formed by the digital printer may not have sufficient adhesive strength with the primer layer or the adhesive layer, so that peeling may occur between the electrostatic ink layer and the primer layer or the adhesive layer when an external force is applied. there is. For example, when tearing open the package, if peeling occurs between the electrostatic ink layer and the primer layer or the adhesive layer, the external force when tearing the packaging bag cannot be sufficiently used to tear the base film, so that it cannot be torn cleanly. There are cases where there is no

Therefore, the present disclosure, in one aspect, has a printed surface printed by a digital printer, but at the time of unsealing or tearing, the interface between the electrostatic ink layer and the primer layer and the interface between the electrostatic ink layer and the adhesive layer A packaging bag in which peeling is suppressed.

A laminate according to one aspect of the present disclosure includes a base film, an adhesive layer, and a sealant film in this order, and has a printing surface of an electrostatic ink composition adhered to the adhesive layer, wherein the adhesive layer comprises: Heating and pressurizing the sealant film on the printing surface, which is composed of an adhesive composition containing a polyol, a polyisocyanate, and an epoxy compound, and at least one of a cured product thereof, under heat sealing conditions at a temperature of 220° C., a pressure of 0.2 MPa, and a time of 1.5 seconds. The color difference (ΔE) calculated by the following formula (A) before and after is less than 3.0.

In the above formula (A), ΔL ^* represents the difference in lightness before and after heating and pressurization under heat-seal conditions, and Δa ^* and Δb ^* are both the hue and chroma before and after heating and pressurization under heat-seal conditions. represents the difference between

Electrostatic ink compositions produced by digital printers tend to have poor heat resistance and strength compared to other inks. For this reason, discoloration occurs when the sealant film of the laminate having the printing surface of the electrostatic ink composition is heated and pressed under heat sealing conditions. In the laminate, the adhesive layer adhering to the printed surface of the electrostatic ink composition is composed of an adhesive composition containing a polyol, a polyisocyanate, and an epoxy compound. This adhesive composition is considered to have an action of coagulating the electrostatic ink composition to improve the strength of the electrostatic ink composition and an action of improving the adhesive strength between layers. For this reason, it is possible to suppress generation of gaps in the vicinity of the printing surface or breakage of the electrostatic ink composition when heating and pressurizing under heat-sealing conditions. Therefore, discoloration of the seal portion accompanying generation of gaps and fractures is suppressed, and discoloration of digital printing can be sufficiently suppressed.

It is preferable that the number of discoloration points having a size of 20 μm or more generated on the printed surface by heating and pressing under the heat sealing condition is 10 or less per 1 mm 2 . Thereby, discoloration of the sealing portion is suppressed, and discoloration due to heat sealing can be sufficiently suppressed.

A laminate according to one aspect of the present disclosure includes a base film, an adhesive layer, and a sealant film in this order, and has a printing surface of an electrostatic ink composition adhered to the adhesive layer, wherein the adhesive layer comprises: When the sealant film on the printed surface, which is composed of an adhesive composition containing a polyol, a polyisocyanate, and an epoxy compound and at least one of a cured product thereof, is heated and pressurized under heat sealing conditions at a temperature of 220° C., a pressure of 0.2 MPa, and a time of 1.5 seconds. The number of discoloration points having a size of 20 μm or more generated is 10 or less per 1 mm 2 .

The printed surface of an electrostatic ink composition by a digital printer tends to have poor heat resistance and strength compared to other inks. For this reason, when the laminated body provided with the sealant film is heated and pressurized under heat sealing conditions, the seal portion is discolored. In the laminate, the adhesive layer adhering to the printed surface of the electrostatic ink composition is composed of an adhesive composition containing a polyol, a polyisocyanate, and an epoxy compound. This adhesive layer is considered to have an action of coagulating the electrostatic ink composition to improve the strength of the electrostatic ink composition. For this reason, when heat sealing is performed, it is possible to suppress generation of gaps in the vicinity of the printing surface or breakage of the electrostatic ink composition. And the number of discoloration points which generate|occur|produce when the said laminated body is heat-sealed is sufficiently reduced. Therefore, discoloration of the seal part can be sufficiently suppressed.

The polyol may include an aliphatic polyester polyol, and the epoxy compound may include one having epoxy groups at both ends. Such an adhesive layer has high adhesive strength especially under a high-temperature environment. Therefore, it is possible to sufficiently suppress generation of gaps in the vicinity of the printing surface or breakage of the electrostatic ink composition during heat sealing. For this reason, discoloration of digital printing accompanying heat sealing can be further suppressed.

The said epoxy compound may contain the bifunctional alicyclic epoxy compound. By being bifunctional, such an epoxy compound increases the cross-linking points with the electrostatic ink composition and adheres firmly to the printed surface. Moreover, by being alicyclic, reaction with polyisocyanate can be suppressed by steric hindrance. For this reason, it hardens stably and can make the adhesiveness of the interface of a printing surface and an adhesive layer sufficiently excellent.

The polyisocyanate may also contain a xylylene diisocyanate derivative. Such polyisocyanates and polyols have excellent reactivity. Thereby, the curability of the adhesive composition is improved, and discoloration of digital printing due to heat sealing can be further suppressed.

In the packaging bag according to one aspect of the present disclosure, sealant films in any of the above-described laminates are heat-sealed to each other to be configured. The packaging bag includes, for example, a pair of laminates, an accommodating portion for accommodating a packing material between the pair of laminates, and a sealing portion configured by heat-sealing each sealant film of the pair of laminates. It is provided, and a pair of laminated bodies may also contain any of the above-mentioned laminated bodies. Since such a packaging bag is equipped with the above laminate, discoloration in the seal portion formed by heat sealing can be sufficiently suppressed. Thereby, the color difference between the non-sealed portion and the sealed portion is reduced, and a clean appearance can be sufficiently maintained.

A package body according to one aspect of the present disclosure includes a packaging bag and a packaging material packaged in the packaging bag. Since this package body is equipped with the said packaging bag, discoloration in the heat-sealed seal part can fully be suppressed. Thereby, the color difference in a non-sealing part and a sealing part is reduced, and the clean external appearance of a laminated body can fully be maintained.

A method for manufacturing a laminate according to one aspect of the present disclosure includes a step of printing an electrostatic ink composition on one side of a base film to obtain a printed surface, a base material including the printed surface and a sealant film, and a polyol, polyisocyanate and The step of obtaining a laminate by adhering using an adhesive composition containing an epoxy compound, before and after heating and pressing the sealant film on the printed surface under heat sealing conditions at a temperature of 220 ° C., a pressure of 0.2 MPa, and a time of 1.5 seconds, as follows, The color difference (ΔE) calculated by formula (A) is less than 3.0 on the basis of before heat sealing.

In the above formula (A), ΔL ^* represents the difference in lightness before and after heating and pressurization under heat-seal conditions, and Δa ^* and Δb ^* are both the hue and chroma before and after heating and pressurization under heat-seal conditions. represents the difference between

The printed surface of an electrostatic ink composition by a digital printer tends to have poor heat resistance and strength compared to other inks. For this reason, discoloration occurs when the sealant film of the laminate having the printing surface of the electrostatic ink composition is heated and pressed under heat sealing conditions. In the laminate, the adhesive composition used for bonding the printed surface of the electrostatic ink composition includes a polyol, a polyisocyanate, and an epoxy compound. This adhesive composition is considered to have an action of coagulating the electrostatic ink composition to improve the strength of the electrostatic ink composition and an action of improving the adhesive strength between layers. For this reason, it is possible to suppress generation of gaps in the vicinity of the printing surface or breakage of the electrostatic ink composition when heating and pressurizing under heat-sealing conditions. Therefore, discoloration of the seal portion accompanying generation of gaps and fractures is suppressed, and discoloration of digital printing can be sufficiently suppressed.

A method for manufacturing a laminate according to one aspect of the present disclosure includes a step of printing an electrostatic ink composition on one side of a base film to obtain a printed surface, a base material including the printed surface and a sealant film, and a polyol, polyisocyanate and 20 generated when the sealant film on the printed surface is heated and pressurized under heat sealing conditions at a temperature of 220 ° C., a pressure of 0.2 MPa, and a time of 1.5 seconds in a step of obtaining a laminate by bonding using an adhesive composition containing an epoxy compound. The number of discoloration points having a size of ㎛ or more is 10 or less per 1 mm 2 .

The printed surface of an electrostatic ink composition by a digital printer tends to have poor heat resistance and strength compared to other inks. For this reason, when the laminated body provided with the sealant film is heated and pressed under heat-sealing conditions, the color is discolored. In the laminate, the adhesive composition used for adhering the printed surface of the electrostatic ink composition includes a polyol, a polyisocyanate, and an epoxy compound. It is thought that this adhesive layer has an action of coagulating the electrostatic ink composition to improve the strength of the electrostatic ink composition and an action of improving the adhesive strength between layers. For this reason, it is possible to suppress generation of gaps in the vicinity of the printing surface or breakage of the electrostatic ink composition when heating and pressurizing under heat-sealing conditions. And the number of discoloration points which generate|occur|produce when the said laminated body is heat-sealed is sufficiently reduced. Therefore, discoloration of the seal part can be sufficiently suppressed.

A laminate according to one aspect of the present disclosure includes a base film, an adhesive layer, and a sealant layer bonded to a spout in this order, and includes an electrostatic ink layer adhered to the adhesive layer for a pouch with a spout. As a laminate of, the adhesive layer is composed of at least one of an adhesive composition containing a polyol, a polyisocyanate, and an epoxy compound, and a cured product thereof.

Electrostatic ink compositions used in digital printing tend to have poor heat resistance compared to other inks. For this reason, when a pouch with a spout is manufactured using a laminate having an electrostatic ink layer composed of an electrostatic ink composition, when the spout and the pouch body are welded, the electrostatic ink layer flows and discoloration occurs at the welded portion. do. On the other hand, in the laminate of the present disclosure, the adhesive layer adhering to the electrostatic ink layer is composed of at least one of an adhesive composition containing a polyol, a polyisocyanate, and an epoxy compound and a cured product thereof. Such an adhesive layer is considered to have an action of sufficiently coagulating the electrostatic ink composition constituting the electrostatic ink layer and an action of improving the adhesive strength. It is considered that such an action occurs when the epoxy compound permeates the electrostatic ink layer from the adhesive layer and crosslinks the epoxy compound and the electrostatic ink composition. Accordingly, the laminate has excellent heat resistance while having an electrostatic ink layer composed of an electrostatic ink composition. Even if such a laminate is used as a laminate (laminated film) for a pouch with a spout to which a spout is welded, discoloration in the welded portion can be sufficiently suppressed.

The laminate may have a primer layer between the base film and the electrostatic ink layer. In this way, the adhesion of the electrostatic ink layer can be further improved.

The polyol in the adhesive layer may include an aliphatic polyester polyol, and the epoxy compound may include one having epoxy groups at both ends. Such an adhesive layer has high adhesive strength even in a high-temperature environment. Therefore, when the spout is welded, it is possible to sufficiently suppress generation of a gap at the interface between the electrostatic ink layer and the adhesive layer or flow of the electrostatic ink layer. For this reason, discoloration accompanying welding can be further suppressed.

The epoxy compound in the adhesive layer may contain a bifunctional alicyclic epoxy compound. By being bifunctional, such an epoxy compound can increase the crosslinking point with the electrostatic ink composition constituting the electrostatic ink layer, thereby further strengthening the adhesion between the adhesive layer and the electrostatic ink layer. Moreover, by being alicyclic, reaction with polyisocyanate can be suppressed by steric hindrance. For this reason, stable curing is realized, and the adhesiveness of the interface between the electrostatic ink layer and the adhesive layer can be sufficiently excellent.

The polyisocyanate may also contain a xylylene diisocyanate derivative. Such polyisocyanates and polyols have excellent reactivity. As a result, the curability of the adhesive layer is improved, and discoloration of the pouch with a spout can be further suppressed.

In the packaging material for a pouch with a spout according to one aspect of the present disclosure, a sealant layer formed by heat-sealing sealant layers in any of the laminates described above and the sealant layers face each other so that the spout is welded. It is provided with a non-see part. In the packaging material for a pouch with a spout, for example, at least one laminate, a seal portion formed by heat sealing the sealant layers in the at least one laminate, and the sealant layers face each other, A non-sealing portion to which the spout is welded is provided, and at least one laminate may include any of the above-described laminates.

Such a packaging material includes a sealing portion formed by heat sealing the sealant films in any of the laminates described above, and a non-sealing portion to which the spout is welded. Since the above-mentioned laminated body is excellent in heat resistance, while suppressing discoloration in a sealing part, generation|occurrence|production of discoloration in the non-sealing part to which a spout is welded can also be suppressed. Therefore, it can be suitably used as a packaging material for a pouch with a spout.

A pouch with a spout according to one aspect of the present disclosure includes: a pouch body having a sealing portion formed by heat sealing sealant layers in any of the above-described laminates and a housing portion for accommodating a packing material; and A spout welded to the sealant layer of the laminate in the above is provided. For example, as a pouch with a spout having a pouch main body and a spout, the pouch main body includes at least one laminate, and a sealing portion in which sealant layers in the at least one laminate are bonded together. , It has an accommodating part for accommodating the packing material, the spout is welded to the sealant layer of the laminated body in the pouch main body, and at least one laminated body may contain any of the above-mentioned laminated bodies.

Since such a laminate is excellent in heat resistance, the pouch with a spout can sufficiently suppress discoloration of the pouch main body in a welded portion with the spout. A pouch with such a spout can fully demonstrate the performance of high-precision digital printing.

A package according to one aspect of the present disclosure includes a pouch with a spout and a packaged object accommodated in the pouch. Since this package includes the pouch with the above spout, discoloration in the welded portion with the spout can be sufficiently suppressed. Such a package can fully exhibit the performance of high-precision digital printing, and can further enhance the quality as a product.

A method for manufacturing a pouch with a spout according to one aspect of the present disclosure includes a base film, an adhesive composition containing a polyol, a polyisocyanate, and an epoxy compound, and an adhesive layer composed of at least one of a cured product thereof, and a sealant layer. A step of manufacturing at least one laminate comprising an electrostatic ink layer bonded to an adhesive layer, a sealing portion formed by heat sealing the sealant layers of the at least one laminate, and a sealant layer It has the process of forming the non-sealing part facing each other and obtaining a packaging material, and the process of inserting the welding part of a spout into the non-sealing part of the packaging material, and welding the said welding part and the sealant layer in a non-sealing part.

In the laminate used in the above production method, the adhesive layer adhering to the electrostatic ink layer is composed of at least one of an adhesive composition containing a polyol, a polyisocyanate and an epoxy compound and a cured product thereof. Such an adhesive layer is considered to have an action of sufficiently coagulating the electrostatic ink composition constituting the electrostatic ink layer and an action of improving the adhesive strength. It is considered that such an action occurs when the epoxy compound permeates the electrostatic ink layer from the adhesive layer and crosslinks the epoxy compound and the electrostatic ink composition. Accordingly, the laminate has excellent heat resistance while having an electrostatic ink layer composed of an electrostatic ink composition. For this reason, when the spout is welded to the laminate, the flow of the electrostatic ink layer is sufficiently suppressed. Therefore, discoloration in the welded part of the pouch with a spout and the spout can be sufficiently suppressed.

In the above manufacturing method, welding of the sealant layer in the welded portion and the non-sealed portion may be performed by heating at 150°C or higher. Thereby, the sealing property of the welded portion can be sufficiently improved while discoloration of the welded portion is sufficiently suppressed.

A packaging bag according to one aspect of the present disclosure is a packaging bag composed of a laminate having a base film (substrate), a primer layer, an electrostatic ink layer, an adhesive layer, and a sealant layer in this order, wherein the adhesive layer comprises a polyol, An adhesive composition containing polyisocyanate and an epoxy compound and at least one of a cured product thereof, wherein the electrostatic ink layer has an ink coverage of 500% or less and an adhesive strength (laminate strength) of the laminate of 2.0 N/15 mm. More than that.

In the laminate constituting the packaging bag, an adhesive layer is composed of at least one of a specific adhesive composition and a cured product thereof, and the adhesive strength of the laminate is equal to or greater than a predetermined value. Thus, even when the ink coverage of the electrostatic ink layer is relatively large, peeling at the interface between the electrostatic ink layer and the primer layer and between the electrostatic ink layer and the adhesive layer is suppressed when the packaging bag is opened or torn. When the packaging bag is opened or torn, the laminated body in the vicinity of the tear portion maintains the state before tearing, and visibility of information written on the printed portion and the like can be maintained satisfactorily.

A packaging bag according to one aspect of the present disclosure is a packaging bag composed of a laminate having a base film, a primer layer, an electrostatic ink layer, an adhesive layer, and a sealant layer in this order, wherein the adhesive layer comprises polyol, polyisocyanate and An adhesive composition comprising an epoxy compound and at least one of a cured product thereof, wherein the electrostatic ink layer has an ink coverage of 100 to 400%, the adhesive strength of the laminate is X, and the retort is performed at 120°C for 30 minutes. When Y is the adhesive strength of the laminate after heat treatment, the value of 100(Y - X)/X is more than -30%.

In the laminate constituting the package, the adhesive layer is composed of a specific adhesive composition and at least one of a cured product thereof, and the change rate of adhesive strength before and after performing a predetermined retort heat treatment (value of 100 (Y - X) / X ) is a predetermined range. Thus, even when the ink coverage of the electrostatic ink layer is relatively large, peeling at the interface between the electrostatic ink layer and the primer layer and between the electrostatic ink layer and the adhesive layer is suppressed when the packaging bag is opened or torn. The packaging bag can clean the tearing surface at the time of opening or tearing. Since the adhesive strength of the laminate does not significantly decrease even when the packaging bag is subjected to high-temperature hot water treatment at 120 ° C. for 30 minutes, it can be suitably used for packaging bags that are subject to sterilization treatment of packaging materials by retort. .

The polyol may include an aliphatic polyester polyol, and the epoxy compound may include one having epoxy groups at both ends. Such an adhesive layer has high adhesive strength especially under a high-temperature environment.

The said epoxy compound may also contain a bifunctional alicyclic epoxy compound. By being bifunctional, such an epoxy compound increases the cross-linking point with the electrostatic ink composition and adheres more firmly to the printed surface (main surface of the primer layer). Moreover, by being alicyclic, reaction with polyisocyanate can be suppressed by steric hindrance. For this reason, it hardens stably and can make the adhesiveness of the interface of a printing part and an adhesive bond layer sufficiently excellent.

The polyisocyanate may also contain a xylylene diisocyanate derivative. Such polyisocyanates and polyols have excellent reactivity. Thereby, the curability of the adhesive composition is improved, and peeling at the interface between the electrostatic ink layer and the primer layer and the interface between the electrostatic ink layer and the adhesive layer can be further suppressed.

The ink application amount on the main surface of the primer layer on the sealant layer side may be 0.5 g/m 2 or more.

The laminate may further include a barrier layer between the adhesive layer and the sealant layer.

In one aspect, the present disclosure can provide a laminate capable of sufficiently suppressing discoloration occurring during heat sealing while having a printed surface by a digital printer. Moreover, it is possible to provide a packaging bag and a package in which discoloration is sufficiently suppressed while having a printing surface by a digital printer.

In one aspect, the present disclosure can provide a laminate excellent in heat resistance while having an electrostatic ink layer composed of an electrostatic ink composition. In addition, a pouch with a spout capable of sufficiently suppressing discoloration of a welded portion with the spout, a manufacturing method thereof, and a package body can be provided while having an electrostatic ink layer composed of an electrostatic ink composition. Moreover, it is possible to provide a packaging material that is preferably used as a pouch main body of a pouch with a spout.

In one aspect, the present disclosure, while having a printed surface printed by a digital printer, at the time of opening or tearing, at the interface between the electrostatic ink layer and the primer layer, and at the interface between the electrostatic ink layer and the adhesive layer A packaging bag in which peeling is suppressed can be provided.

1 is a cross-sectional view showing an example of a laminate.
2 is a cross-sectional view showing another example of a laminate.
Fig. 3 is an optical microscope photograph showing the surface of the laminate after heating and pressurization in an enlarged manner.
Fig. 4 is a plan view showing an example of a packaging bag and a package body.
Fig. 5 is a perspective view showing another example of a packaging bag.
Fig. 6 is a perspective view showing an example of a pouch with a spout and a package.
Fig. 7 is a plan view showing an example of a packaging material for a pouch with a spout.
8 : is a figure when the spout shown in FIG. 7 is seen from the welding part side.
Fig. 9(A) is an optical microscope photograph showing the surface of the layered product (before heat sealing) used in Example 1-7 in an enlarged manner. (B) is an optical microscope photograph showing the surface of the seal portion after heat sealing of the laminate of Example 1-7 in an enlarged manner.
Fig. 10(A) is an optical microscope photograph showing an enlarged surface of the laminate (before heat sealing) used in Comparative Example 1-7. (B) is an optical microscope photograph showing the surface of the seal portion after heat sealing of the laminate of Comparative Example 1-7 in an enlarged manner.
11(A) is a photograph showing the external appearance of the sample for evaluation after welding in Example 2-1. (B) is a photograph showing the appearance of the sample for evaluation after welding in Example 2-2.
12(A) is a photograph showing the appearance of the sample for evaluation after welding in Comparative Example 2-1. (B) is a photograph showing the external appearance of the sample for evaluation after welding of Comparative Example 2-2.
Fig. 13(A) is a photograph showing the appearance of the sample for evaluation after welding in Comparative Example 2-4. (B) is a photograph showing the external appearance of the sample for evaluation after welding of Comparative Example 2-5.
Fig. 14(A) is a photograph showing the external appearance of the sample for evaluation after welding in Comparative Example 2-6. (B) is a photograph showing the external appearance of the sample for evaluation after welding of Comparative Example 2-7.
Fig. 15 is a view showing a part of the tear surface when the packaging bag according to one embodiment is opened.
Fig. 16 is a view showing a part of the tear surface when a conventional packaging bag is opened.

Embodiments of the present disclosure will be described below with reference to drawings where necessary. However, the following embodiments are examples for explaining the present disclosure, and are not intended to limit the present disclosure to the following contents. In the description, the same reference numerals are used for the same elements or elements having the same functions, and overlapping descriptions are omitted in some cases. In addition, positional relationships such as up, down, left, and right shall be based on the positional relationships shown in the drawings unless otherwise specified. In addition, the dimensional ratios in the drawings are not limited to the ratios shown.

The materials exemplified in the present disclosure can be used singly or in combination of two or more, unless otherwise specified. The content of each component in the composition means the total amount of the plurality of substances present in the composition, unless otherwise specified, when a plurality of substances corresponding to each component in the composition are present.

[First Embodiment]

<An example of the structure of a laminated body>

1 is a cross-sectional view schematically showing an example of a laminate. 1 shows a cross section along the lamination direction (thickness direction) of a laminate. The laminate 300 has a base film 10, a primer layer 40, an adhesive layer 30, and a sealant film 20 (sealant layer 20) in this order. A primer layer 40 is formed on one side of the base film 10 near the sealant film 20 .

The base film 10 and the sealant film 20 may be a flexible base material. The flexible base material may be equipped with one or both of metal foil, such as an aluminum foil, and a film-shaped thermoplastic polymer, for example. As the flexible substrate, biaxially oriented polypropylene (BOPP), polyethylene terephthalate (PET), oriented polyamide (OPA), unstretched polypropylene (CPP), linear low density polyethylene (LLDPE), low density polyethylene (LDPE) of the film can be cited.

The base film 10 may be, for example, a vapor-deposited film (transparent vapor-deposited film) in which aluminum or aluminum oxide or the like is vapor-deposited on a PET film. Examples of the sealant film 20 include a CPP film, an LLDPE film, and an OPP film. The thickness of the base film 10 and the sealant film 20 may be 7 to 150 μm, 15 to 90 μm, or 20 to 80 μm.

The primer layer 40 may contain resin. Examples of the resin include polyvinyl alcohol resins, cellulose resins, polyesters, polyamines, polyethyleneimine resins, polyamide resins, polyurethanes, polyacrylic polymer hydroxyl-containing resins, carboxyl group-containing resins, and amine-based polymers. . By having the primer layer 40, printing of the electrostatic ink composition using a digital printer can be performed smoothly. Moreover, the adhesiveness of the electrostatic ink layer 50 can be improved. The application amount of the resin constituting the primer layer 40 may be, for example, 0.01 to 1.5 g/m 2 or 0.05 to 1.0 g/m 2 .

The layered product 300 has a printing surface 52 on the primer layer 40 . On the printing surface 52, an electrostatic ink layer 50 is formed. The electrostatic ink layer 50 may be composed of halftone dots of an electrostatic ink composition. The electrostatic ink layer 50 is formed by electrostatic printing using a digital printer. In Fig. 1, a plurality of electrostatic ink layers 50 may have the same composition or may have different colors by having mutually different compositions. The electrostatic ink layer 50 may be formed so as to be dotted on the primer layer 40 or may be formed so as to cover the entire one side of the primer layer 40 .

The printing surface 52 having the electrostatic ink layer 50 is covered with an adhesive layer 30 . The adhesive layer 30 may be composed of an adhesive composition, a cured product thereof, or a mixture thereof. The adhesive composition contains a polyol, a polyisocyanate, and an epoxy compound. At least a part of these three components (polyol, polyisocyanate, and epoxy compound) may react with each other and be cured to become a cured product. On the printing surface 52, the adhesive layer 30 containing the above three components and the electrostatic ink layer 50 are in direct contact. When the epoxy compound included in the adhesive layer 30 and the ink composition included in the electrostatic ink layer 50 crosslink each other, the adhesive strength of the adhesive layer 30 and the electrostatic ink layer 50 on the printing surface 52 is high enough.

<Color difference of laminate (ΔE)>

In the laminate 300, the color difference before and after heating and pressurizing the sealant films 20 with each other under heat sealing conditions at a temperature of 220 ° C., a pressure of 0.2 MPa, and a time of 1.5 seconds is less than 3.0 on the basis of before heat sealing. . The "color difference (ΔE)" in the present disclosure is a measured value calculated from the measured values of a spectrophotometer (eg, eXact (device name) manufactured by X-rite). A specific calculation procedure is described below.

A layered product 300 having a printing surface 52 of an electrostatic ink composition is prepared. Using the spectrophotometer described above, lightness (L ^* ), hue and chroma (a ^* , b ^* ) are measured on the surface 300A of the layered product 300.

Then, it heats and pressurizes on the said heat sealing condition from the surface 300A side of the laminated body 300 using the heat sealing apparatus. Before and after heating and pressurization, the lightness (L ^* ), hue and chroma (a ^* , b ^* ) of the surface 300A are measured using the same spectrophotometer. The measurement positions of the surface 300A before and after the heating and pressurization by the heat sealer are made the same. The color difference (ΔE) is calculated from the difference in lightness (ΔL ^* ) before and after heating and pressurization by the heat sealer, and the difference in hue and chroma (Δa ^* , Δb ^* ) by the following formula (A). The color difference calculated in this way is the "color difference (ΔE)" in the present disclosure.

The color difference may be less than 3.0, may be 1.5 or less, or may be 1.3 or less from the viewpoint of sufficiently suppressing discoloration during heat sealing. The lower limit of the color difference may be 0.1 or more, or 0.3 or more, from the viewpoint of ease of manufacture. When the surface 300A is viewed in a plan view, the coverage ratio of the electrostatic ink layer 50 to the entire area (area) to be measured for color difference may be 50 area% or more, 70 area% or more, or 100% by area. It may be area %. The coverage ratio of 100 area% means that the entire area to be measured for "color difference" is covered with the electrostatic ink layer 50 . The coverage ratio of 50 area% means that half of the area to be measured for "color difference" is covered with the electrostatic ink layer 50 . In the laminate 300 of FIG. 1 , the coverage ratio of the electrostatic ink layer 50 to the entire region (area) to be measured for “color difference” is about 55 area%.

As a factor capable of reducing the color difference before and after heat sealing, the component contained in the adhesive layer 30 aggregates the electrostatic ink composition of the electrostatic ink layer 50 to improve the strength of the electrostatic ink layer 50 itself. It is thought to have an action and an action of improving the adhesive strength between the electrostatic ink layer 50 and the layer adjacent thereto. As a result, gaps are generated at the interfaces between the electrostatic ink layer 50, the adhesive layer 30, and the primer layer 40, the electrostatic ink layer 50 is moved and deformed, or the electrostatic ink layer 50 is broken. can suppress it. For this reason, discoloration accompanying the occurrence of gaps, deformation and fracture is suppressed, and it is considered that discoloration of the printing surface 52 can be sufficiently suppressed.

<Another example of the structure of a laminated body>

2 is a cross-sectional view showing another example of a laminate. The laminate 310 of FIG. 2 is different from the laminate 300 of FIG. 1 in that the whole of one side of the primer layer 40 is covered with the electrostatic ink layer 51 . That is, in the laminate 310, the coverage ratio of the electrostatic ink layer 50 to the entire region (area) to be measured for "color difference" is 100 area%. Other configurations of the laminate 310 may be the same as those of the laminate 300 in FIG. 1 . The color difference in the sealed part when the laminate 310 is heat-sealed is also measured in the same manner as in the laminate 300 .

The electrostatic ink layers 50 and 51 on the printing surface 52 of FIGS. 1 and 2 are composed of circular halftone dots of an electrostatic ink composition. By changing the size of halftone dots, the color intensity on the printing surface 52 can be adjusted.

<Discoloration point in laminated body>

3 is an optical microscope photograph showing the heated and pressurized surface in an enlarged manner when the surface of the laminate film side on the sealant film side is heated and pressurized under the above-described heat-sealing conditions. In Fig. 3, discoloration points 55 are generated in halftone dots 53 (electrostatic ink layer) on the heated and pressurized surface of the laminate. This discoloration point 55 indicates that a gap is generated at the interface between the halftone dot 53 and the adhesive layer 30 or that the halftone dot 53 is deformed. The discoloration point 55 may originate from air bubbles in the interface.

In the laminates 300 and 310, since the strength of the electrostatic ink layers 50 and 51 composed of halftone dots is sufficiently high, and the adhesive strength between the electrostatic ink layers 50 and 51 and the adhesive layer 30 is sufficiently high, The discoloration point 55 as shown in FIG. 3 can fully be reduced. As shown in FIG. 3 , in an area of 1 mm 2 (= 1.0 mm × 1.0 mm) selected arbitrarily among observation images obtained by enlarging the surface 300A of the laminate 300 by 100 times using an optical microscope, the above The number of discoloration points having a size of 20 µm or more generated when heated and pressurized under the above heat-sealing conditions is preferably 10 or less, more preferably 6 or less, still more preferably 3 or less. By reducing the discoloration point 55 in this way, color nonuniformity that occurs during heat sealing can be more sufficiently suppressed. The number of discoloration points having a size of 20 μm or more is obtained by drawing a circumscribed circle of the discoloration point 55 as shown in FIG. 3 and counting those having a diameter of 20 μm or more of the circumscribed circle. In the present disclosure, a discoloration point is a comparison between before and after heating and pressurization, and the shape, size, color, etc. of the halftone point can be detected when visually observing an enlarged image of an optical microscope (magnification: 100 times). that is changing to an extent.

<Ingredients of Electrostatic Ink Composition>

In the laminates 300 and 310, the electrostatic ink composition constituting the electrostatic ink layers 50 and 51 is an ink composition used for liquid electrophotographic printing, that is, electrostatic printing, and is printed on substrates such as paper and plastic. do. The electrostatic ink composition may also contain a coloring agent or pigment, such as a dye, and resin. Moreover, in addition to these, you may contain a carrier fluid or a carrier liquid. In addition, a charge director, a charge adjuvant, a surfactant, a viscosity modifier, an emulsifier and other additives may be included.

As a coloring agent, a cyan pigment, a magenta pigment, a yellow pigment, and a black pigment are mentioned, for example. From the viewpoint of easily performing digital printing, as the resin, a resin having a relatively low melting point (for example, 100°C or less) can be used. Examples of the resin include thermoplastic resins such as ethylene acrylic acid copolymers, propylene acrylic acid copolymers, ethylene methacrylic acid copolymers, propylene methacrylic acid copolymers, and ethylene vinyl acetate copolymers. It is preferable that resin contains at least one of an ethylene acrylic acid copolymer and an ethylene methacrylic acid copolymer.

Examples of the carrier fluid and carrier liquid include hydrocarbons, silicone oil, and vegetable oil. Examples of hydrocarbons include aliphatic hydrocarbons, branched chain aliphatic hydrocarbons, and aromatic hydrocarbons. The electrostatic ink composition may be substantially free of a carrier liquid when printed on a printing substrate, for example, a first substrate. For example, the carrier liquid may be removed by an electrophoretic process or evaporation during printing. In this way, substantially only the solid content is transferred to the printing substrate.

The charge director has a function of maintaining sufficient electrostatic charge in the particles included in the electrostatic ink composition. As the charge director, for example, ionic compounds such as metal salts of fatty acids, metal salts of sulfosuccinates, metal salts of oxyphosphates, metal salts of alkylbenzenesulfonic acids, metal salts of aromatic carboxylic acids or aromatic sulfonic acids, and polyoxyethylenation double counterionic and nonionic compounds such as alkylamines, lecithin, polyvinylpyrrolidone, and organic acid esters of polyhydric alcohols.

The charge adjuvant has an action of increasing or stabilizing the electric charge of the particles included in the electrostatic ink composition. As the charge adjuvant, for example, barium petronate, calcium petronate, naphthenic acid Co salt, naphthenic acid Ca salt, naphthenic acid Cu salt, naphthenic acid Mn salt, naphthenic acid Ni salt, naphthenic acid Zn salt, naphthenic acid Fe salts, stearic acid Ba salt, stearic acid Co salt, stearic acid Pb salt, stearic acid Zn salt, stearic acid Al salt, stearic acid Cu salt, stearic acid Fe salt, and metal carboxylates.

The electrostatic ink composition may contain a crosslinked product crosslinked by a component included in the adhesive layer 30 and/or the primer layer 40. Thereby, the strength of the electrostatic ink layer 50 itself, and the adhesive strength between the printing surface 52 and the electrostatic ink layer 50 and between the electrostatic ink layer 50 and the primer layer 40 can be sufficiently increased. In addition, during heat sealing, it is possible to suppress movement of dots constituting the electrostatic ink layer 50 or occurrence of gaps at the interface between the electrostatic ink layer 50 and the adhesive layer 30. Thereby, discoloration accompanying heat sealing can be sufficiently suppressed.

<Ingredients of Adhesive Composition>

The printing surface 52 of the electrostatic ink composition and the adhesive layer 30 are adhered to each other. That is, the printing surface 52 serves as an adhesive surface with the adhesive layer 30, and the electrostatic ink composition and the adhesive composition are in direct contact. The adhesive composition contains a polyol, a polyisocyanate, and an epoxy compound. These three components are explained below.

A polyol has, for example, a number average molecular weight of 400 or more, and has two or more hydroxyl groups in one molecule. Polyisocyanate has two or more isocyanate groups in one molecule. Polyols and polyisocyanates react as a base material and curing agent, respectively, to produce a polyurethane (polyurethane adhesive). The polyol may have a number average molecular weight of, for example, 10000 or less.

The polyol may contain at least one selected from the group consisting of polyester polyols and polyether polyols. Among these, from the viewpoint of sufficiently increasing the adhesive strength of the adhesive layer 30 in a high-temperature environment, the polyol may contain a polyester polyol or may contain an aliphatic polyester polyol.

As a polyester polyol, it is obtained by the condensation reaction of a polyhydric alcohol, a polybasic acid, its alkyl ester, its acid anhydride, or its acid halide, or transesterification reaction, for example. Examples of the polyhydric alcohol include low molecular weight diols, low molecular weight triols, and low molecular weight polyols having 4 or more hydroxyl groups.

Examples of the low molecular weight diol include ethylene glycol, propylene glycol, trimethylene glycol, 1,4-butylene glycol, 1,3-butylene glycol, 1,2-butylene glycol, and 1,5-pentanediol. , 3-methyl-1,5-pentanediol, 2,2-dimethyl-1,3-propanediol, neopentyl glycol, 1,6-hexanediol, 2,2-diethyl-1,3-propanediol, 3,3-dimethylolheptane, 2-ethyl-2-butyl-1,3-propanediol, etc. are mentioned.

Examples of low molecular weight triols include glycerin, 2-methyl-2-hydroxymethyl-1,3-propanediol, 2,4-dihydroxy-3-hydroxymethylpentane, 1,2,6 -hexanetriol, trimethylolethane, trimethylolpropane, 2-methyl-2-hydroxymethyl-1,3-propanediol, 2,4-dihydroxy-3-(hydroxymethyl)pentane, and 2, 2-bis(hydroxymethyl)-3-butanol etc. are mentioned.

Examples of the low molecular weight polyol having 4 or more hydroxyl groups include tetramethylolmethane, pentaerythritol, dipentaerythritol, D-sorbitol, xylitol, D-mannitol, and D-mannit. .

Examples of the alkyl esters of polybasic acids include methyl esters and ethyl esters of polybasic acids. Acid anhydrides include acid anhydrides derived from polybasic acids. Examples thereof include oxalic anhydride, succinic anhydride, maleic anhydride, phthalic anhydride, 2-alkyl (C 12-18) succinic anhydride, tetrahydrophthalic anhydride, and trimellitic anhydride.

Examples of the acid halide include acid halides derived from the above polybasic acids. For example, oxalic acid dichloride, adipic acid dichloride, sebacic acid dichloride, etc. are mentioned.

Polyether polyol may be polyalkylene oxide. For example, it may be obtained by subjecting an alkylene oxide such as ethylene oxide and/or propylene oxide to an addition reaction using a low molecular weight polyol as an initiator. As a specific example, polyethylene glycol, polypropylene glycol, and polyethylene polypropylene glycol (random or block copolymer) are mentioned. Moreover, polytetramethylene ether glycol etc. obtained, for example by ring-opening polymerization of tetrahydrofuran etc. are mentioned.

As polyisocyanate, a polyisocyanate monomer, a polyisocyanate derivative, and an isocyanate group terminal prepolymer etc. are mentioned, for example. The adhesive composition may contain multiple types of polyisocyanates different from each other. The molar ratio (NCO/OH) of the isocyanate groups contained in the polyisocyanate to the hydroxyl groups of the polyol may be 0.5 to 10. Such an adhesive composition can form a cured product having high adhesive strength and excellent flexibility.

As a polyisocyanate monomer, aliphatic polyisocyanate, aromatic polyisocyanate, aromatic aliphatic polyisocyanate, alicyclic polyisocyanate, etc. are mentioned, for example.

Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, 1,2-propylene diisocyanate, and butylene diisocyanate (tetramethylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1, 3-butylene diisocyanate), 1,5-pentamethylene diisocyanate (PDI), hexamethylene diisocyanate (HDI), 2,4,4-trimethylhexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate , and 2,6-diisocyanate methyl capate.

Examples of aromatic aliphatic polyisocyanates include xylylene diisocyanate derivatives. Examples of the xylylene diisocyanate derivative include xylylene diisocyanate (1,3-xylylene diisocyanate or 1,4-xylylene diisocyanate) (XDI), tetramethylxylylene diisocyanate (1,3 -Tetramethylxylylenediisocyanate, or 1,4-tetramethylxylylenediisocyanate) (TMXDI), ω,ω'-diisocyanate-1,4-diethylbenzene, and mixtures of xylylenediisocyanate and trimethylolpropane The polyol modified body of xylylene diisocyanate obtained by reaction, etc. are mentioned.

The content of the xylylenediisocyanate derivative relative to the total polyisocyanate may be 10% by mass or more, 20% by mass or more, or 30% by mass or more, from the viewpoint of improving reactivity with the main agent (eg, polyol), 40 mass % or more may be sufficient. Reactivity can be made still higher by setting it as 30 mass % or more.

Examples of the alicyclic polyisocyanate include 1,3-cyclopentane diisocyanate, 1,3-cyclopentene diisocyanate, and cyclohexane diisocyanate (1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, isocyanate), 3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate (isophorodiisocyanate) (IPDI), methylcyclohexanediisocyanate (methyl-2,4-cyclohexanediisocyanate, methyl-2 ,6-cyclohexane diisocyanate), norbornane diisocyanate (NBDI), and the like.

As the polyisocyanate derivative, for example, the polymer of the above-described polyisocyanate monomer, a modified allophanate, a modified polyol, a modified polyol produced by a reaction between a monomer and an alcohol, a modified biuret, and a modified urea. , modified oxadiazinetrione, modified carbodiimide, modified uretdione, modified uretonimine, and the like.

The isocyanate group terminal prepolymer is a urethane prepolymer having at least two isocyanate groups at molecular terminals. It can be obtained by subjecting at least one member selected from the group consisting of a polyisocyanate monomer, a polyisocyanate derivative, and an isocyanate group terminal prepolymer to a urethanization reaction with a polyol. At this time, the molar ratio (NCO/OH) of the isocyanate groups contained in the polyisocyanate to the hydroxyl groups of the polyol may be 0.5 or more, 0.6 or more, 0.8 or more, 1 or more, or 1.5 or more. The molar ratio (NCO/OH) may be 10 or less, 5 or less, 4 or less, or 3 or less. Examples of the numerical range of the molar ratio (NCO/OH) include 0.5 to 10, 0.5 to 5, 0.8 to 4, and 0.6 to 3.

The epoxy compound may be a compound having one or two or more epoxy groups in one molecule. From the viewpoint of further increasing the adhesive strength of the adhesive layer 30 in a high-temperature environment, it may have epoxy groups at both ends. Examples of the epoxy compound include glycidyl ether type epoxy compounds, glycidyl amine type epoxy compounds, glycidyl ester type epoxy compounds, and alicyclic epoxy compounds (cyclic aliphatic epoxy compounds).

The molecular weight of the epoxy compound may be 500 or less, 450 or less, or 400 or less. Such an epoxy compound can be sufficiently penetrated into the electrostatic ink composition constituting the electrostatic ink layer. The lower limit of the molecular weight of the epoxy compound may be, for example, 98.

Examples of the alicyclic epoxy compound include epoxycyclohexylmethyl-epoxycyclohexane carboxylate and bis(epoxycyclohexyl) adipate.

Examples of monofunctional alicyclic epoxy compounds having one epoxy group per molecule include 3,4-epoxycyclohexylmethyl methacrylate, 1,2-epoxy-4-vinylcyclohexane, and the like. Examples of the bifunctional epoxy compound having two epoxy groups in one molecule include 3',4'-epoxycyclohexylmethyl-3,4epoxycyclohexanecarboxylate and bis(3,4-epoxycyclohexylmethyl) adipate. , and 4-vinylcyclohexene dioxide, etc. are mentioned. Moreover, 1,2-epoxy-4-(2-oxy of 2,2-bis(hydroxymethyl)-1-butanol represented by the following general formula (I) as an epoxy compound which has one or more epoxy groups in 1 molecule ranyl) cyclohexane adducts.

[Formula 1]

In the said general formula (I), n may be an integer of 1-4.

It is preferable that an epoxy compound contains a bifunctional alicyclic epoxy compound. By being bifunctional, the crosslinking point between the electrostatic ink composition and the primer resin can be increased, thereby accelerating the curing reaction of the adhesive and making it easier to cure. Moreover, by being alicyclic, reaction with polyisocyanate can be suppressed by steric hindrance. For this reason, it hardens stably and can make the adhesiveness of the interface of the printing surface 52 and the adhesive bond layer 30 sufficiently excellent.

In the adhesive composition, the content of the epoxy compound relative to 100 parts by mass of the polyol may be 3 to 25 mass, 6 to 25 mass, or 8 to 20 mass, from the viewpoint of achieving both high adhesive strength and excellent shear suppression. can also be granted When the content of the epoxy compound becomes excessive, there is a tendency for excellent shearing suppression ability to be inhibited. That is, when the adhesive layer 30 is formed, the adhesive surface may shift or the adhesive composition may protrude. If the compounding amount of the epoxy compound is too small, the adhesive strength under high-temperature hydrothermal treatment conditions tends to decrease.

In the adhesive composition, the content of polyisocyanate with respect to 100 parts by mass of polyol may be 10 to 50 parts by mass, or 15 to 35 parts by mass, from the viewpoint of sufficiently increasing the seal strength and the adhesive strength under high-temperature hydrothermal treatment conditions. It may be, and 20 to 30 mass provision may be sufficient.

The molar ratio of the epoxy groups contained in the epoxy compound to the isocyanate groups contained in the polyisocyanate may be 0.5 to 10, 1.5 to 9, or 2.0 to 6.5. As a result, a sufficiently high adhesive strength can be maintained under high-temperature hydrothermal treatment conditions.

The adhesive composition constituting the adhesive layer 30 may contain arbitrary components such as additives in addition to the components described above. Examples of additives include antioxidants, ultraviolet absorbers, light stabilizers, fillers, silane coupling agents, epoxy resins, catalysts, coatability improvers, leveling agents, nucleating agents, lubricants, release agents, antifoaming agents, plasticizers, surfactants, pigments, dyes, organic fine particles, inorganic fine particles, anti-mold agents, flame retardants, and the like. The adhesive composition may contain solvents such as organic solvents.

<Function of adhesive composition>

The adhesive composition adheres the print surface 52 on which the electrostatic ink composition is printed and the sealant film 20. An arbitrary layer may be provided between the sealant film 20 and the adhesive layer 30 . In this case, the adhesive composition adheres the printed surface 52 and an arbitrary layer. The adhesive composition exhibits a function as an adhesive by forming a urethane bond through a reaction between a polyol and a polyisocyanate. Since the formation of the urethane bond proceeds smoothly even in the presence of the epoxy compound, the printing surface 52 and the sealant film 20 or any layer can be bonded with a sufficiently high adhesive strength.

The adhesive composition may have a function of crosslinking the electrostatic ink composition forming the electrostatic ink layers 50 and 51 together with formation of a urethane bond. In this way, the adhesive strength between the printing surface 52 and the sealant film 20 or any layer can be improved. Even if the ink coverage on the printing surface 52 increases, the epoxy compound sufficiently penetrates into the electrostatic ink layer 50 constituted by the electrostatic ink composition by increasing the content of the epoxy compound contained in the adhesive composition accordingly. can make it The permeated epoxy compound has an effect of increasing the strength of the electrostatic ink composition (electrostatic ink layers 50 and 51) by crosslinking the electrostatic ink composition. For this reason, even if the ink coverage in the printing surface 52 becomes high, discoloration accompanying heat sealing can be suppressed. In addition, even when heat treatment such as retort heat treatment is performed, a decrease in adhesive strength can be sufficiently suppressed. The meaning of the ink coverage in the present disclosure will be explained in a second embodiment to be described later.

While the adhesive composition can maintain high adhesive strength even after heat treatment, it is also excellent in pot life. For this reason, workability such as coating and lamination processing at the time of adhering the printed surface and the substrate is also excellent. The adhesive composition may contain a polyol and polyisocyanate that form urethane, and an epoxy compound, and at least a part thereof may be a cured product to form an adhesive layer. This can reduce the number of layers constituting the laminate 300 compared to the case where the adhesive layer containing only polyurethane and the epoxy coating layer are separately formed. For this reason, when manufacturing a laminated body by roll-to-roll, for example, problems, such as meandering of a roll after aging and generation|occurrence|production of wrinkles by blocking, etc., do not arise. Moreover, the aging process after coating can be reduced, and efficiency improvement of manufacture can be aimed at.

In the laminates 300 and 310 in which the electrostatic ink layers 50 and 51 on the printing surface 52 and the adhesive layer 30 are in direct contact, components such as epoxy compounds and/or polyisocyanates contained in the adhesive composition It sufficiently permeates into the electrostatic ink layers 50 and 51. In this way, the electrostatic ink composition constituting the electrostatic ink layers 50 and 51 can be crosslinked to improve the strength of the electrostatic ink composition (electrostatic ink layers 50 and 51). Moreover, the adhesive strength between each layer can be improved. In addition, even when the printing surface 52 includes a plain portion (transparent portion) without the electrostatic ink layer 50 as shown in FIG. 1, since the epoxy compound is contained in the adhesive layer, stickiness can be eliminated. On the other hand, if the epoxy coating layer is formed separately from the adhesive layer 30, when the printing surface 52 includes a plain portion, the epoxy compound becomes excessive in the vicinity of the plain portion, and stickiness tends to occur. In this way, the layered product 300 can remove stickiness while adhering the printing surface 52 including the plain portion where the electrostatic ink layer 50 is not formed with a high adhesive strength.

<Uses and Specific Examples of Laminates>

Since the laminates 300 and 310 can suppress color unevenness in the printed portion, they may be used as packaging materials for foods and sanitary products for which appearance is important. However, the use is not limited to these. For example, since it has excellent adhesive strength and seal strength even after high-temperature hydrothermal treatment and retort heat treatment, it may be used as a retort packaging material, a microwave oven compatible packaging material, a boiling packaging material, and a self-use packaging material. The thickness of the laminates 300 and 310 may be, for example, 15 to 200 μm or 18 to 120 μm.

The laminate according to the modified example does not have to have the primer layer 40, and may have the primer layer 40 on each of the opposite surfaces of the base film 10 and the sealant film 20. In addition, between the base film 10 and the sealant film 20, between the base film 10 and the primer layer 40, from the viewpoint of improving the gas barrier properties and water vapor barrier properties of the laminates 300 and 310, and And/or between the sealant film 20 and the adhesive layer 30, you may have at least one of a metal layer, such as an aluminum foil, and a resin layer, such as a nylon film.

Specific examples of the layer structure of the laminate are illustrated below. In each example, the base film 10 is at the left end and the sealant film 20 is at the right end, and each layer is sequentially laminated from left to right. Moreover, the 1st adhesive bond layer is the adhesive bond layer 30, and the 2nd adhesive bond layer may be a conventional adhesive bond layer.

(1) transparent vapor deposition PET film/primer layer/electrostatic ink layer/first adhesive layer/nylon layer/second adhesive layer/CPP film (unstretched polypropylene film)

(2) PET film/primer layer/electrostatic ink layer/first adhesive layer/aluminum layer/second adhesive layer/CPP film (unstretched polypropylene film)

(3) Nylon layer/primer layer/electrostatic ink layer/first adhesive layer/LLDPE (linear low density polyethylene) film

(4) PET film/primer layer/electrostatic ink layer/first adhesive layer/nylon layer/second adhesive layer/CPP film

(5) PET film/primer layer/electrostatic ink layer/first adhesive layer/PET film

(6) OPP film (biaxially oriented polypropylene film) / primer layer / electrostatic ink layer / first adhesive layer / CPP film

(7) PET film/primer layer/electrostatic ink layer/first adhesive layer/LLDPE film

(8) transparent vapor deposition PET film/primer layer/electrostatic ink layer/first adhesive layer/CPP film

(9) PET film/primer layer/electrostatic ink layer/first adhesive layer/aluminum deposition barrier film/LLDPE film

(10) OPP film/primer layer/electrostatic ink layer/first adhesive layer/aluminum deposition barrier film/second adhesive layer/CPP film

(11) PET film/primer layer/electrostatic ink layer/first adhesive layer/OPP film/second adhesive layer/CPP film

(12) PET film / primer layer / electrostatic ink layer / first adhesive layer / nylon layer / second adhesive layer / LLDPE film

In each of the above specific examples, there may be no primer layer. Moreover, you may form arbitrary layers in arbitrary positions. (1) and (2) are packaging materials for retort, (3) packaging materials for boiling or pizza and pet food, (4) packaging materials for microwave ovens, (5) packaging materials for can labels, (6) ) and (7) are packaging materials for confectionery, noodles and broth, (8) and (12) are packaging materials for crackers and cookies, (9) are packaging materials for supplements, pet snacks, vegetables and coffee, (10) (11) is preferably used as a packaging material for fish feed and coffee, (11) is a packaging material for frozen foods, and (12) is a packaging material with an inlet stopper. However, the uses are not limited to those described above.

<Example of manufacturing method of laminated body>

An example of a method for manufacturing a laminate is described below. In this example, the laminate 300 shown in FIG. 1 is manufactured. First, a step of forming a primer layer 40 on one side of a base film 10, and printing an electrostatic ink composition on the primer layer 40 to form an electrostatic ink layer 50 to form a printed surface 52 and a step of adhering the printed surface 52 and one side of the sealant film 20 together using an adhesive composition.

The primer layer 40 may be formed on one side of the base film 10 by flexographic printing or gravure printing. The primer layer 40 can be formed by crosslinking a resin raw material with a crosslinking agent. Crosslinking may be performed by irradiation with ionizing radiation such as ultraviolet light, heating, or electron beam, and non-ionizing radiation such as microwave radiation. The electrostatic ink composition can be printed by electrostatic printing using a digital printer. As a digital printer, "Indigo20000 digital printer for labels and packages" manufactured by HP, for example, can be used. In this way, the electrostatic ink layer 50 is formed and the printing surface 52 is obtained.

The bonding of the printing surface 52 and one side of the sealant film 20 with the adhesive composition can be performed by lamination. Lamination can be performed using arbitrary equipment. The epoxy compound and/or polyisocyanate included in the adhesive composition permeates the electrostatic ink composition and the primer layer 40 constituting the electrostatic ink layer 50, and crosslinks with components included in the electrostatic ink composition and the primer layer 40. you can react In this way, while the strength of the electrostatic ink layer 50 is improved, a laminate 300 in which the interfaces of the respective layers are sufficiently bonded can be obtained. During lamination, at least a part of the adhesive composition may be cured to become a cured product. In this way, the laminate 300 comprising the base film 10, the primer layer 40, the electrostatic ink layer 50, the adhesive layer 30 and the sealant film 20 in this order can be manufactured. . The laminate 310 and the laminate related to the modification can also be manufactured in the same way as the laminate 300.

The laminates 300 and 310 manufactured in this way have the configuration and properties as described above. The explanation content related to the laminates 300 and 310 and their modified examples is also applied to the example of the manufacturing method described above.

The laminates 300 and 310 are preferably used as packaging materials. A packaging bag can be manufactured using the laminates 300 and 310 as a packaging material.

<Example of structure of packaging bag>

Fig. 4 is a plan view showing an example of a packaging bag formed using the above-described laminate. The packaging bag 100 is configured by bonding sealant films 20 of a pair of laminates 300 (310) together. The packaging bag 100 includes a sealing portion 101 formed by bonding the peripheries of a pair of film-shaped substantially rectangular laminates 300 (310), and a pair of laminates ( 300 (310)) and an accommodating portion 102 formed between them. That is, the side end, lower end, and upper end of the packaging bag 100 are sealed by the seal part 101. The packaging bag 100 has an accommodating portion 102 in which an object to be packaged (e.g., food) is accommodated in an unsealed portion (sheet portion) surrounded by the sealing portion 101. In addition, you may seal the sealing part 101 of a lower end part after filling the housing part 102 with a to-be-packaged object. The sealing part 101 is formed by heat sealing the sealant films 20 with each other.

It is not essential that the pair of packaging materials constituting the packaging bag 100 have the same layer configuration, and for example, the pair of packaging materials may be composed of laminates having mutually different layer configurations.

The packaging bag 100 may be equipped with an opening means 120 for facilitating opening. The opening means is a pair of easy-opening processing parts 124 consisting of a V-shaped notch formed in the seal part 101 at the side end, and a cut between the pair of easy-opening processing parts 124. It has a half-cut line 121 that becomes an orbit. The half cut line 121 can be formed using a laser. The easy-opening processing part 124 is not limited to a V-shaped notch, and may be a U-shaped or I-shaped notch, or may be a group of scars.

<Method of manufacturing packaging bag and packaging body>

Procedures for manufacturing the packaging bag 100 and the packaging body 200 using the laminate 300 will be described below. As a packaging material, a pair of laminated body 300 cut into a predetermined shape is prepared. The sealant films 20 formed on one side of each laminate 300 are opposed to each other, and the sealant films 20 are bonded to each other. Thus, the sealing portion 101 is formed at the upper end and the side end, and the non-sealing portion surrounded by the sealing portion 101 in a C shape is formed. In this way, a packaging bag 110 in which only the upper end (or only the lower end) is not sealed as shown in Fig. 5 is obtained. In some other embodiments of the packaging bag, as shown in Fig. 5, a part of the periphery may not be sealed.

Next, the packing material is filled from the upper end (or lower end) in the unsealed state. After that, the laminates 300 are bonded to each other at the upper end (or lower end) to form the seal part 101 also at the upper end (or lower end). In this way, the package 200 provided with the packaging bag 100 and the packing material accommodated in it can be manufactured.

The packaging bag 100 and the packaging body 200 are manufactured using the laminated body 300. For this reason, the discoloration in the sealing part 101 can fully be suppressed. For this reason, color uniformity at the time of making the sealing part 101 and the non-sealing part in the inner side the same color is fully maintainable, for example. In addition, since the laminate 300 used as a packaging material has excellent heat resistance, it can also be suitably used for foods heated with hot water or a microwave oven. Examples of the package 200 include a retort package heated by boiling or microwave oven. The packaging bag 100 and the package 200 may be replaced with the laminate 300, and may be manufactured using the laminate 310 or a laminate related to these modified examples.

As mentioned above, although several examples were described, this embodiment is not limited to the said example at all. For example, the laminate may be a packaging film adhered to the surface of a PET bottle. Further, the shape of the packaging bag is not limited to a four-way bag, and may be, for example, a two-way bag, a three-way bag, a joint bag, or a standing pouch. Certain elements illustrated in the second and third embodiments can also be applied to the present embodiment.

[Second Embodiment]

Like the laminate of the first embodiment, the laminate of the present embodiment also has a base film, a primer layer, an adhesive layer, and a sealant layer in this order when viewed in a cross section along the thickness direction. As the sealant layer, a conventional sealant film can be used. The structure of the laminate of this embodiment is the same as that of the first embodiment, and examples thereof include the laminate 300 in FIG. 1 and the laminate 310 in FIG. 2 . Therefore, the contents of the descriptions of <an example of a structure of a laminate> and <another example of a structure of a laminate> in the first embodiment are applied to the present embodiment. That is, the laminate of this embodiment may have the same configuration as the laminates 300 and 310 of the first embodiment.

<Ink coverage>

As shown in FIG. 1 , the layered product 300 has a printing surface 52 on the primer layer 40 . On the printing surface 52, an electrostatic ink layer 50 is formed. The electrostatic ink layer 50 is formed between the adhesive layer 30 and the primer layer 40, one side of the electrostatic ink layer 50 is adhered to the adhesive layer 30, and the other side is the primer layer ( 40) is attached.

As shown in FIG. 2 , the laminate 310 has the electrostatic ink layer 51 covering the entirety of one side of the adhesive layer 30 and the entirety of the one side of the primer layer 40. It is different from the laminate 300. Other configurations of the laminate 310 may be the same as those of the laminate 300 in FIG. 1 .

The ink coverage (ink coverage) on the printing surface 52 is not particularly limited, and may be, for example, 10 to 500% or 50 to 500%. The ink coverage (ink coverage) in the present disclosure indicates the ratio of dot area per unit area. For example, the ink coverage when a predetermined area is uniformly printed in a single color is 100%. On the other hand, the ink coverage of the non-printing area becomes 0%. Based on both of these, the ink coverage can be calculated. In the case of printing with inks of a plurality of colors, the ink coverage of each color ink can be calculated, and the sum can be used as the ink coverage of the target electrostatic ink layer. The ink coverage can be set in a digital printer (for example, "Indigo20000 Digital Printer for Labels and Packages" manufactured by HP) and can be adjusted by designating a desired value in the setting of the ink coverage. In addition, the ink coverage on the printed surface 52 can be confirmed by observing the printed surface 52 with an optical microscope.

<Components and Actions of Adhesive Layer>

The printing surface 52 having the electrostatic ink layers 50 and 51 is covered with an adhesive layer 30 . The adhesive layer 30 may be composed of an adhesive composition, a cured product thereof, or a mixture thereof. The adhesive composition contains a polyol, a polyisocyanate, and an epoxy compound. At least a part of these three components (polyol, polyisocyanate, and epoxy compound) may react with each other and be cured to become a cured product. The epoxy compound contained in the adhesive layer 30, and the polyurethane produced|generated by the reaction of a polyol and polyisocyanate may be crosslinked. Thereby, the heat resistance of the adhesive bond layer 30 can be improved.

The adhesive layer 30 containing the above three components and the electrostatic ink layers 50, 51 are adhered to each other. The epoxy compound contained in the adhesive layer 30 permeates the electrostatic ink layers 50 and 51, and the epoxy compound and the electrostatic ink composition may be crosslinked. As a result, the electrostatic ink composition is sufficiently coagulated and the adhesion is improved. Thereby, the heat resistance of the layered product 300 can be improved.

In the laminates 300 and 310, the electrostatic ink composition constituting the electrostatic ink layers 50 and 51 composed of halftone dots sufficiently aggregates and has high adhesive strength. For this reason, the laminates 300 and 310 are excellent in heat resistance. Therefore, the laminates 300 and 310 can be suitably used as a laminate (laminated film) for a pouch with a spout to which the spout is welded.

<Ingredients of Electrostatic Ink Composition and Adhesive Composition>

In the laminates 300 and 310, the electrostatic ink composition constituting the electrostatic ink layers 50 and 51 and the adhesive composition constituting the adhesive layer 30 are the "components of the electrostatic ink composition" of the first embodiment. And it is as having demonstrated in the column of "contained components of adhesive composition". Therefore, these descriptions in the first embodiment are also applied to the present embodiment.

<Function of adhesive composition>

The adhesive composition adheres the print surface 52 on which the electrostatic ink composition is printed and the sealant layer 20. An arbitrary layer may be provided between the sealant layer 20 and the adhesive layer 30 . In this case, the adhesive composition adheres the printed surface 52 and an arbitrary layer. The adhesive composition exhibits a function as an adhesive by forming a urethane bond through a reaction between a polyol and a polyisocyanate. Since the formation of the urethane bond proceeds smoothly even in the presence of the epoxy compound, the print surface 52 and the sealant layer 20 or any layer can be bonded with a sufficiently high adhesive strength.

While the adhesive composition is excellent in adhesive strength at high temperatures, it is also excellent in pot life. For this reason, workability such as coating and lamination processing at the time of adhering the printed surface and the substrate is also excellent. The adhesive composition may contain a polyol that forms urethane, a polyisocyanate, and an epoxy compound, and at least a part thereof may be a cured product to form the adhesive layer 30 . This can reduce the number of layers constituting the laminate 300 compared to the case where the adhesive layer containing only polyurethane and the epoxy coating layer are separately formed. For this reason, when manufacturing a laminated body by roll-to-roll, for example, problems, such as meandering of a roll after aging and generation|occurrence|production of wrinkles by blocking, etc., do not arise. Moreover, the aging process after coating can be reduced, and efficiency improvement of manufacture can be aimed at.

In the laminate 300, 310 in which the electrostatic ink layers 50, 51 and the adhesive layer 30 are in direct contact, components such as an epoxy compound and/or polyisocyanate contained in the adhesive composition are used in the electrostatic ink layers 50, 51. can infiltrate In this way, the electrostatic ink composition constituting the electrostatic ink layers 50 and 51 is crosslinked, and the electrostatic ink composition (the electrostatic ink layers 50 and 51) is aggregated to improve strength at high temperatures. Moreover, the adhesive force with a neighboring layer can be improved. In addition, even when the printing surface 52 includes a plain portion (transparent portion) without the electrostatic ink layer 50 as shown in FIG. 1, since the epoxy compound is included in the adhesive layer 30, stickiness can be eliminated. . On the other hand, if the epoxy coating layer is formed separately from the adhesive layer 30, when the printing surface 52 includes a plain portion, the epoxy compound becomes excessive in the vicinity of the plain portion, and stickiness tends to occur. In this way, the layered product 300 can remove stickiness while adhering the printing surface 52 including the plain portion where the electrostatic ink layer 50 is not formed with a high adhesive strength.

The laminates 300 and 310 have high-temperature strength superior to that of the electrostatic ink layer 50, and also excellent adhesive strength at high temperatures. Therefore, it is possible to sufficiently suppress the flow and movement of the electrostatic ink layer 50 when it is welded to the spout. Thereby, discoloration in the welding part with a spout can fully be suppressed.

<Modified Example of Laminate>

The laminate according to the modified example does not have to have the primer layer 40, and may have the primer layer 40 on each of the opposite surfaces of the base film 10 and the sealant layer 20. In addition, between the base film 10 and the sealant layer 20, between the base film 10 and the primer layer 40, from the viewpoint of improving the gas barrier properties and water vapor barrier properties of the laminates 300 and 310, and And/or between the sealant layer 20 and the adhesive layer 30, you may have at least one of a metal layer, such as an aluminum foil, and a resin layer, such as a nylon film.

<Specific examples of the layer structure of the laminated body>

Specific examples of the layer structure of the laminate are illustrated below. In each example, the base film 10 is at the left end and the sealant layer 20 is at the right end, and each layer is sequentially laminated from left to right. Moreover, the 1st adhesive bond layer is the adhesive bond layer 30. The second adhesive layer and the third adhesive layer may be the same adhesive layer as the adhesive layer 30, or may be a normal adhesive layer different from this.

(1) transparent vapor deposition PET film/primer layer/electrostatic ink layer/first adhesive layer/nylon layer/second adhesive layer/CPP film (unstretched polypropylene film)

(2) PET film/primer layer/electrostatic ink layer/first adhesive layer/aluminum layer/second adhesive layer/CPP film (unstretched polypropylene film)

(3) Nylon layer/primer layer/electrostatic ink layer/first adhesive layer/LLDPE (linear low density polyethylene) film

(4) PET film/primer layer/electrostatic ink layer/first adhesive layer/nylon layer/second adhesive layer/CPP film

(5) PET film/primer layer/electrostatic ink layer/first adhesive layer/LLDPE film

(6) transparent vapor deposition PET film/primer layer/electrostatic ink layer/first adhesive layer/CPP film

(7) PET film/primer layer/electrostatic ink layer/first adhesive layer/aluminum deposition barrier film/LLDPE film

(8) OPP film/primer layer/electrostatic ink layer/first adhesive layer/aluminum deposition barrier film/second adhesive layer/CPP film

(9) PET film/primer layer/electrostatic ink layer/first adhesive layer/nylon layer/second adhesive layer/LLDPE film

(10) transparent vapor deposition PET film / primer layer / electrostatic ink layer / first adhesive layer / nylon layer / second adhesive layer / LLDPE film

(11) transparent vapor deposition PET film / primer layer / electrostatic ink layer / first adhesive layer / nylon layer / second adhesive layer / LDPE film

(12) PET film / primer layer / electrostatic ink layer / first adhesive layer / aluminum layer / second adhesive layer / nylon layer / third adhesive layer / LLDPE film

(13) PET film / primer layer / electrostatic ink layer / first adhesive layer / aluminum layer / second adhesive layer / nylon layer / third adhesive layer / LDPE film

(14) PET film / primer layer / electrostatic ink layer / first adhesive layer / nylon layer / second adhesive layer / aluminum layer / third adhesive layer / LLDPE film

(15) PET film / primer layer / electrostatic ink layer / first adhesive layer / nylon layer / second adhesive layer / aluminum layer / third adhesive layer / LDPE film

In each of the above specific examples, there may be no primer layer. Moreover, you may form arbitrary layers in arbitrary positions. The manufacturing method of the laminated body of this embodiment can be manufactured by carrying out similarly to 1st Embodiment. Therefore, the description of <Example of the manufacturing method of a laminated body> in 1st Embodiment is also applied to this Embodiment.

The laminates 300 and 310 are preferably used as a packaging material for a pouch with a spout (pouch body). The laminates 300 and 310 can be used as a packaging material to produce a spout-attached pouch.

<Structure of pouch with attached spout, packaging material, and packaging body>

Fig. 6 is a perspective view showing an example of a pouch with a spout and a package. The pouch 400 with an attached spout includes a pouch main body 410 having a so-called side gusset type shape and a spout 420 welded to an upper end of the pouch main body 410 . The pouch body portion 410 has a seal portion 401 configured by bonding sealant layers 20 of a plurality of stacked bodies 300 (310) to each other by heat sealing. By the seal part 401, the bag body which can accommodate the to-be-packed object inside is formed.

The pouch 400 with a spout can accommodate the to-be-packaged object 202 (for example, beverage) inside the pouch main body 410 . Thereby, the package 200 in which the to-be-packaged object 202 was accommodated can be obtained. That is, the package 200 includes a pouch 400 with a spout, and a packing material 202 accommodated in an accommodating portion formed by the seal portion 401 of the pouch body portion 410 .

Fig. 7 is a plan view showing a packaging material 440 for a pouch with a spout and a spout 420 welded thereto. On the outer edge of the packaging material 440 serving as the pouch body portion 410, a sealing portion 401 configured by heat-sealing the laminates 300 (310) to each other, and a welded portion 426 of the spout 420 A non-sealing portion 402 to which is welded is formed. In the seal part 401, sealant layers 20 are bonded to each other by heat sealing. On the other hand, in the non-sealing portion 402, the sealant layers 20 are not adhered to each other, and the sealant layers 20 are disposed opposite to each other. That is, the unsealed portion 402 is a through hole that communicates the inside and outside of the pouch body portion 410 .

The spout 420 includes a tube portion 422 constituting a flow path through which the packing material 202 flows, a welded portion 426 formed at the lower end of the tube portion 422, and a cover screwed to the upper end of the tube portion 422. It has a sieve 421. In the welding portion 426, a plurality of welding ribs 426r are formed in a transverse stripe shape in order to strengthen the welding between the welding portion 426 and the packaging material 440. However, it is not limited to having the welding rib 426r, and the welding rib 426r may be absent. A flange 424 and a flange 423 are formed on the outer circumferential surface of the tube portion 422 in this order from the welded portion 426 side so as to extend to the side of the tube portion 422 . The cylinder part 422, the welding part 426, the flange 424, and the flange 423 may be integrally molded products using synthetic resin. Examples of these synthetic resins include high-density polyethylene resin (HDPE), low-density polyethylene resin (LDPE), linear low-density polyethylene resin (L-LDPE), polypropylene resin (PP), polyester-based resin, and vinyl chloride. Resin, ABS resin, etc. are mentioned. The cover body 421 may also be a molded article molded using the synthetic resin described above.

The pouch 400 with a spout shown in FIG. 6 can be manufactured by welding the welded portion 426 of the spout 420 to the unsealed portion 402 of the packaging material 440 shown in FIG. 7 . Welding is performed by heating and pressurizing the welded portion 426 and the sealant layer 20 of the laminate 300 (310) in a superimposed state.

8 : is a figure when the spout 420 is seen from the welding part 426 side. That is, it is a figure when the spout 420 shown in FIG. 7 is seen from the lower side of FIG. 7 toward the upper direction. The welded portion 426 of the spout 420 has a lozenge-shaped planar shape. The welding rib 426r formed in the welding part 426 protrudes outward from parts other than the welding rib 426r. Thereby, welding between the welded portion 426 and the sealant layer 20 in the non-sealed portion 402 is sufficiently reliably performed, and the sealability in the welded portion 450 (FIG. 6) can be improved. At the center of the welded portion 426, a flow path 428 for the packing material is formed. Using this flow path 428, the packing material can be filled in the storage part of the spout-attached pouch, or the packing material can be taken out from the storage part.

When the sealant layer 20 of the laminate 300 (310) is welded to the welded portion 426, the welded portion 426 and the sealant layer 20 come into contact with each other with the welded portion 426 interposed therebetween. The laminate 300 (310) is arranged and pressed using a heated mold or the like so as to follow the surface of the welded portion 426. In this way, the sealant layer 20 is welded to the welding portion 426 to obtain a pouch with a spout. At this time, the portion welded to the welded portion 426 of the laminate 300 (310) is exposed to high temperature while being pressurized. For this reason, when the heat resistance of the electrostatic ink layer included in the laminate is low, the electrostatic ink layer melts and flows and moves from the pressurized portion to the non-pressurized portion. When the electrostatic ink layer melts and moves in this way, discoloration occurs at the welded portion 450 in FIG. 6 .

The electrostatic ink layer 50 (51) in the layered product 300 (310) is sufficiently aggregated and has excellent adhesive strength, so it is also excellent in heat resistance. For this reason, it is possible to suppress melting and flow of the electrostatic ink layer 50 (51) when it is welded to the welding portion 426. For this reason, discoloration in the welded portion 450 can be sufficiently suppressed.

The shape of the spout and the pouch to which the spout is attached is not limited to that shown. For example, the welded part 426 of the spout 420 may have a perfect circular or elliptical planar shape instead of a rhombic planar shape. Further, the packaging material 440 (pouch body portion 410) may have a shape other than the shape of the side gusset type. For example, the shape of a two-way envelope, a three-way envelope, a four-way envelope, or a jointed envelope may be sufficient.

<Method of manufacturing a pouch with a spout, a packaging material, and a packaging body>

A procedure for manufacturing a packaging material using the laminate 300 (310) will be described below. According to the shape of the packaging material (pouch body part) to be manufactured, one or a plurality of laminates 300 (310) cut into a predetermined shape are prepared. The sealant layers 20 formed on one side of the laminate 300 (310) are made to face each other, and the sealant layers 20 are heat-sealed and adhered to each other. A packaging material (pouch body portion 410) having a side gusset type shape as shown in Figs. 6 and 7 may be manufactured. In this way, a packaging material 440 having a seal portion 401 formed by heat sealing on an outer edge portion as shown in FIG. 7 and a non-seal portion 402 in which sealant layers 20 are opposed to each other, form

The welded portion 426 of the spout 420 is inserted into the through hole that communicates the inside and outside of the packaging material 440 formed by the unsealed portion 402, and the welded portion 426 is formed by the pair of laminates 300. It is heated and pressurized in the state of sandwiching, and the welding part 426 and the sealant layer 20 of the laminated body 300 (310) are welded. In this way, the pouch 400 with a spout having the welding part 450 as shown in FIG. 6 can be manufactured. When the lid 421 of the spout 420 of the pouch 400 with a spout is opened, the packing material is filled, and the lid 421 is sealed, the package 200 as shown in FIG. 6 is obtained

The heating temperature at the time of welding the welded portion 426 and the sealant layer 20 may be 150°C or higher, 170°C or higher, or 190°C or higher. Thereby, the welded portion 426 of the spout 420 and the sealant layer 20 can be sufficiently firmly welded, and the sealability of the welded portion 450 can be sufficiently increased. Moreover, even if it performs welding at such a temperature, discoloration in the welding part 450 can fully be suppressed. The upper limit of the heating temperature may be 220°C or less from the viewpoint of the heat resistance of the layered product 300 (310) and the welded portion 426.

The laminate 300 (310) has excellent heat resistance while having the electrostatic ink layer 50 (51), so it can be suitably used for foods heated with hot water. The package 200 may be used as a package for normal beverages or the like, or may be used as a boiling or retort package.

As mentioned above, several examples have been described, but the present embodiment is not limited to the above examples at all. Any element illustrated in the first embodiment and the third embodiment can also be applied to the present embodiment.

[Third Embodiment]

<Example of structure of packaging bag>

The packaging bag of this embodiment is constituted by a laminate having a substrate (base film), a primer layer, an electrostatic ink layer, an adhesive layer, and a sealant layer in this order. As the sealant layer, a conventional sealant film can be used. A package body is provided with a packaging bag and a to-be-packaged object accommodated in this. The structures of the packaging bag and package in this embodiment are the same as those in the first embodiment, and an example thereof is the packaging bag 100 (package 200) in FIG. 4 can be heard Therefore, the descriptions of <Example of Structure of Packaging Bag> and <Method of Manufacturing Packaging Bag and Package> in the first embodiment are also applied to this embodiment.

<Example of the structure of a laminated body>

The laminated body constituting the packaging bag of this embodiment is the same as that of the first embodiment, and examples thereof include the laminated body 300 in FIG. 1 and the laminated body 310 in FIG. 2 . The laminate 300 of FIG. 1 has a base film 10, a primer layer 40, an adhesive layer 30, and a sealant layer 20 in this order. The base film 10, the primer layer 40, the adhesive layer 30, and the sealant layer 20 may each have a film-like shape. An electrostatic ink layer 50 is formed on at least a part of the main surface of the primer layer 40 on the sealant layer 20 side.

The thickness of the layered product 300 may be, for example, 15 to 200 μm or 18 to 120 μm.

The base film 10 and the sealant layer 20 may be a flexible base material. Flexible substrates include, for example, biaxially oriented polypropylene (BOPP), polyethylene terephthalate (PET), oriented polyamide (OPA), unstretched polypropylene (CPP), linear low density polyethylene (LLDPE), and Low density polyethylene (LDPE) etc. are mentioned.

As the base film 10, a composite film bonded together with metal foil on a flexible substrate may be used, or a vapor-deposited film obtained by depositing a metal on a flexible substrate may be used, for example. Further, the metal may be, for example, aluminum or aluminum oxide. For the base film 10, from the viewpoint of improving gas barrier properties, a deposited film (transparent deposited film) in which aluminum or aluminum oxide or the like is deposited on a PET film can be used. The thickness of the base film 10 may be, for example, 7 to 150 μm, 15 to 90 μm, or 20 to 80 μm.

As the sealant layer 20, a CPP film, an LLDPE film, an OPP film, etc. are mentioned, for example. The thickness of the sealant layer 20 may be the same as or different from the thickness of the base film 10, and may be, for example, 7 to 150 μm, 15 to 90 μm, or 20 to 80 μm.

The primer layer 40 may contain resin. Examples of the resin include polyvinyl alcohol resin, cellulose resin, polyester, polyamine, polyethyleneimine resin, polyamide resin, polyurethane, polyacrylic polymer hydroxyl-containing resin, carboxyl group-containing resin, and amine polymer. can be heard By forming the primer layer 40 on the substrate to be printed, the electrostatic ink composition can be smoothly printed using a digital printer. The coating amount of the resin constituting the primer layer 40 may be, for example, 0.01 to 1.5 g/m 2 or 0.05 to 1.0 g/m 2 .

The layered product 300 has a printing surface 52 on the primer layer 40 . On the printing surface 52, an electrostatic ink layer 50 is formed. The electrostatic ink layer 50 is composed of an electrostatic ink composition and is formed by electrostatic printing using a digital printer. In Fig. 1, a plurality of electrostatic ink layers 50 may have the same composition or may have different colors by having mutually different compositions. The electrostatic ink layer 50 may be formed so as to be dotted on the primer layer 40 or may be formed so as to cover the entire one side of the primer layer 40 .

The electrostatic ink layer 50 on the printing surface 52 is composed of circular halftone dots of an electrostatic ink composition. In other words, even if it is uniformly seen as a single color, there is a blank area between halftone dots. The electrostatic ink layer 50 is generally formed by disposing circular halftone dots spaced apart from each other when printing a predetermined area to be printed in a single color. When printing in two or more colors, halftone dots of the electrostatic ink composition of the second and subsequent colors are arranged between the halftone dots printed in the first color or partially overlapping the halftone dots printed in the first color. In this way, the electrostatic ink layer 50 having two or more colors is constituted. By changing the size of halftone dots, the color intensity on the printing surface 52 can be adjusted. In addition, the color tone on the printing surface 52 can be adjusted by arranging halftone dots of different colors.

The ink coverage of the electrostatic ink layer 50 is 500% or less, may be 450% or less, or 400% or less. By setting the ink coverage of the electrostatic ink layer 50 within the above range, the adhesive strength of the laminate is excellent (laminate strength), printing using a plurality of inks is possible, and various printing can be supported. The ink coverage of the electrostatic ink layer 50 is not particularly limited. For example, it may be 20% or more, 50% or more, 80% or more, or 100% or more. The ink coverage of the electrostatic ink layer 50 may be adjusted within the range described above, and may be, for example, 20 to 500%, 50 to 400%, or 100 to 400%. The meaning of the ink coverage in the present disclosure is as described in the second embodiment.

Since the electrostatic ink layer 50 is composed of circular halftone dots of the electrostatic ink composition, even when the ink coverage is 100%, the surface of the electrostatic ink layer 50 on the sealant layer 20 side can be observed with an optical microscope or the like. If so, the main surface of the primer layer 40 can be confirmed. That is, even if the ink coverage is 100%, the primer layer 40 and the adhesive layer 30 can be directly bonded. On the other hand, as the ink coverage becomes a larger value, the presence ratio of the primer layer 40 on the adhesive surface between the printed surface 52 and the adhesive layer 30 tends to decrease. In the case of using a conventional adhesive, when the ink coverage increases, the adhesive force at the interface between the electrostatic ink layer and the primer layer or the interface between the electrostatic ink layer and the adhesive layer decreases, and the adhesive strength as a laminate is not exhibited as expected. there was a case On the other hand, in the laminate according to the present embodiment, sufficient adhesive strength can be exhibited even when the ink coverage is large by using the adhesive composition described later.

The ink application amount on the main surface of the primer layer 40 on the sealant layer 20 side may be, for example, 0.5 g/m 2 or more, 1.0 g/m 2 or more, 2.0 g/m 2 or more, or 3.0 g/m 2 or more. do. When the ink application amount is within the above range, it is possible to obtain a variety of printing expressions composed of a plurality of colors. The ink application amount on the main surface of the primer layer 40 on the side of the sealant layer 20 may be, for example, 8.0 g/m 2 or less or 6.0 g/m 2 or less. When the ink application amount is within the above range, the decrease in adhesive force at the interface between the electrostatic ink layer 50 and the primer layer 40 or the interface between the electrostatic ink layer 50 and the adhesive layer 30 can be more sufficiently suppressed. can The ink application amount in this disclosure means the total amount (solid content) of the ink composition used for printing, and means the total value in the case of multi-color printing.

The laminate 310 of FIG. 2 is different from the laminate 300 of FIG. 1 in that the whole of one side of the primer layer 40 is covered with the electrostatic ink layer 51 . That is, in the laminate 310, the coverage ratio of the main surface of the primer layer 40 by the electrostatic ink layer 50 is 100 area%. By using the adhesive composition described later, even if the primer layer 40 and the adhesive layer 30 have a structure similar to that of the laminate 310 in which direct adhesion is difficult, they have sufficient adhesive strength and delamination in the laminate 310 etc. are suppressed. Other configurations of the laminate 310 may be the same as those of the laminate 300 .

<Adhesive strength of laminate (laminate strength)>

The adhesive strength of the laminates 300 and 310 is 2.0 N/15 mm or more. The adhesive strength is, for example, 2.2 N/15 mm or more, 2.5 N/15 mm or more, 2.7 N/15 mm or more, 2.9 N/15 mm or more, or It can also be 3.0 N/15 mm or more. When the adhesive strength of the laminate is within the above range, it means that the adhesive strength at the interface between the electrostatic ink layer and the primer layer and the interface between the electrostatic ink layer and the adhesive layer is excellent. As a result, the external force applied when tearing the packaging bag composed of the laminate can be sufficiently used for tearing the base film. By such an action, the packaging bag can be opened cleanly.

The adhesive strength in the present disclosure means peel adhesive strength measured based on the description of JIS K 6854-1: 1999, and can be specifically measured by the method described in Examples of the present disclosure.

When the adhesive strength of the laminates 300 and 310 is X, and the adhesive strength of the laminate after retort heat treatment at 120 ° C. for 30 minutes is Y, 100 (Y - X) / X [rate of change in adhesive strength ] is greater than -30%. The change rate of the adhesive strength can be, for example, -25% or more, -20% or more, or -15% or more. If the rate of change in the adhesive strength of the laminates 300 and 310 is within the above range, the adhesive strength of the laminates does not significantly decrease even when a high-temperature hot water treatment such as sterilization treatment is performed on the packing material by retort. This means that the adhesive strength at the interface between the electrostatic ink layer and the primer layer and the interface between the electrostatic ink layer and the adhesive layer is excellent. For this reason, the external force at the time of tearing the packaging bag comprised from the said laminated body can fully be utilized for tearing of a base film. Due to this action, the packaging bag can be opened cleanly even after the high-temperature hot water treatment has been performed.

<Ingredients of Electrostatic Ink Composition>

In the laminates 300 and 310, the electrostatic ink composition constituting the electrostatic ink layers 50 and 51 is as described in the column of "Components of the electrostatic ink composition" in the first embodiment. Therefore, the description of "components contained in the electrostatic ink composition" of the first embodiment is also applied to the present embodiment.

<Ingredients of Adhesive Composition>

The adhesive composition contains a polyol, a polyisocyanate, and an epoxy compound. At least a part of these three components (polyol, polyisocyanate, and epoxy compound) may react with each other and be cured to become a cured product. That is, the adhesive composition may be composed of at least one of an adhesive composition containing a polyol, a polyisocyanate, and an epoxy compound and a cured product thereof, and the adhesive layer 30 is composed of an adhesive composition, a cured product thereof, or a mixture thereof. it may be Polyols and polyisocyanates react as a base material and curing agent, respectively, to produce a polyurethane (polyurethane adhesive).

About each component of adhesive composition, it is as having demonstrated in the column of "contained component of adhesive composition" of 1st Embodiment. Therefore, the description of the "components contained in the adhesive composition" in the first embodiment is also applied to the present embodiment.

<Function of adhesive layer and adhesive composition>

The adhesive composition adheres the print surface 52 on which the electrostatic ink composition is printed and the sealant layer 20. An arbitrary layer may be provided between the adhesive layer 30 and the sealant layer 20 . The laminates 300 and 310 may further have a barrier layer or the like between the adhesive layer 30 and the sealant layer 20, for example. In this case, the adhesive composition adheres the printed surface 52 and an arbitrary layer (eg, a barrier layer). The adhesive composition exhibits a function as an adhesive by forming a urethane bond through a reaction between a polyol and a polyisocyanate. Since the formation of the urethane bond proceeds smoothly even in the presence of the epoxy compound, the print surface 52 and the sealant layer 20 or any layer can be bonded with a sufficiently high adhesive strength.

The adhesive composition may have a function of crosslinking the electrostatic ink composition forming the electrostatic ink layers 50 and 51 together with formation of a urethane bond. Thereby, the adhesive strength between the printing surface 52 and the sealant layer 20 or any layer can be further improved.

When the coverage ratio of the main surface of the primer layer 40 by the electrostatic ink layer 50 is high, or when the ink coverage ratio in the electrostatic ink layers 50 and 51 is high, generally the electrostatic ink layer 50 The adhesive force between the adhesive layer 30 and the adhesive layer 30 tends to decrease. However, if it is the adhesive composition mentioned above, sufficient adhesive strength can be exhibited. In addition, when the coverage ratio of the electrostatic ink layer 50 to the main surface of the primer layer 40 or the ink coverage ratio in the electrostatic ink layers 50 and 51 increases, the epoxy compound included in the adhesive composition accordingly by increasing the content of As a result, the epoxy compound can be sufficiently penetrated into the electrostatic ink layers 50 and 51 constituted by the electrostatic ink composition, and the decrease in adhesive strength can be further suppressed. The permeated epoxy compound has an effect of increasing the strength of the electrostatic ink composition (electrostatic ink layers 50 and 51) by crosslinking the electrostatic ink composition. For this reason, even when a heat treatment such as retort heat treatment is applied to a laminate having a high ink coverage on the printing surface 52, the decrease in adhesive strength can be sufficiently suppressed.

While the adhesive composition can maintain high adhesive strength even after heat treatment, it is also excellent in pot life. For this reason, it is excellent also in workability|operativity, such as coating and lamination process, at the time of adhering a printing surface and a base film. The adhesive composition may contain a polyol and polyisocyanate that form urethane, and an epoxy compound, and at least a part thereof may be a cured product to form an adhesive layer. This can reduce the number of layers constituting the laminate 300 compared to the case where the adhesive layer containing only polyurethane and the epoxy coating layer are separately formed. For this reason, when manufacturing a laminated body by roll-to-roll, for example, generation|occurrence|production of wrinkles by meandering of the roll after aging, blocking, etc. can be suppressed. Moreover, the aging process after coating can be reduced, and efficiency improvement of manufacture can be aimed at.

In the laminates 300 and 310 in which the electrostatic ink layers 50 and 51 on the printing surface 52 and the adhesive layer 30 are in direct contact, components such as epoxy compounds and/or polyisocyanates contained in the adhesive composition It sufficiently permeates into the electrostatic ink layers 50 and 51. In this way, the electrostatic ink composition constituting the electrostatic ink layers 50 and 51 can be crosslinked to improve the strength of the electrostatic ink composition (electrostatic ink layers 50 and 51). Moreover, the adhesive strength between each layer can be improved. In addition, even when the printing surface 52 includes a plain portion (transparent portion) without the electrostatic ink layer 50 as shown in FIG. 1, since the epoxy compound is contained in the adhesive layer, stickiness can be eliminated. On the other hand, when the epoxy coating layer is formed separately from the adhesive layer 30, when the printing surface 52 includes a plain portion, the epoxy compound becomes excessive in the vicinity of the plain portion, and stickiness tends to occur. In this way, the layered product 300 can remove stickiness while adhering the printed surface 52 including the plain portion on which the electrostatic ink layer 50 is not formed with high adhesive strength.

<Uses and Functions of Laminates>

As described above, the laminates 300 and 310 can sufficiently secure the adhesive strength between the electrostatic ink layers 50 and 51, the base film 10, the primer layer 40, and the adhesive layer 30. can Thereby, peeling between the electrostatic ink layers 50 and 51 in tear surface vicinity, the base film 10, the primer layer 40, and the adhesive layer 30 is suppressed. Therefore, when tearing the laminated bodies 300 and 310, an external force can be sufficiently transmitted to the base film 10 to tear it. In this way, a packaging bag having excellent tear resistance can be configured. When opening such a packaging bag, the packaging bag can be opened along a previously assumed tearing line. Moreover, at the time of opening, scattering of a packing material can be suppressed, and an opening surface can also be made clean. Even after opening, the information written on the printed surface can be read, and it is useful as a packaging bag for food and hygiene products, etc. where appearance is important. However, the use is not limited to these. For example, since it has excellent adhesive strength and seal strength even after high-temperature hydrothermal treatment and retort heat treatment, it may be used as a packaging material for retorts, packaging materials compatible with microwave ovens, and self-use packaging materials.

<Specific examples of the layer structure of the laminated body>

Specific examples of the layer structure of the laminate are illustrated below. In each example, the left end corresponds to the base film 10 and the right end corresponds to the sealant layer 20, and each layer is sequentially laminated from left to right. Moreover, the 1st adhesive bond layer is the adhesive bond layer 30, and the 2nd adhesive bond layer and the 3rd adhesive bond layer may be conventional adhesive layers.

(1) transparent vapor deposition PET film/primer layer/electrostatic ink layer/first adhesive layer/nylon layer/second adhesive layer/CPP film (unstretched polypropylene film)

(2) PET film/primer layer/electrostatic ink layer/first adhesive layer/aluminum layer/second adhesive layer/nylon layer/third adhesive layer/CPP film (unstretched polypropylene film)

(3) PET film/primer layer/electrostatic ink layer/first adhesive layer/nylon layer/second adhesive layer/CPP film (unstretched polypropylene film)

(4) PET film/primer layer/electrostatic ink layer/first adhesive layer/aluminum layer/second adhesive layer/polyethylene film

In each of the above specific examples, an arbitrary layer may be formed at an arbitrary position between the first adhesive layer and the sealant layer 20 . (1) and (2) are preferably used as a laminate for retort, (3) for a microwave oven, and (4) for a packaging bag whose contents are supplements or face masks. However, the uses are not limited to those described above.

<Method for manufacturing laminated body>

The manufacturing method of the laminated body of this embodiment can be manufactured by carrying out similarly to 1st Embodiment. Therefore, the description of <Example of the manufacturing method of a laminated body> in 1st Embodiment is also applied to this Embodiment.

As mentioned above, although some embodiment was described, this indication is not limited to the embodiment mentioned above. Any element illustrated in the first embodiment and the second embodiment can also be applied to the present embodiment.

Example

The contents of the present disclosure will be described in more detail with reference to examples, but the present disclosure is not limited to the following examples.

(Example 1-1)

[Production of Laminate]

As a base film, an alumina vapor deposition PET film (trade name: GLARHF, thickness: 12 µm, manufactured by Topan Printing Co., Ltd.) was prepared. A water-based primer resin (resin containing polyethyleneimine, manufactured by Michelman, trade name: DP050) was applied to the alumina deposition surface to form a primer layer. It applied so that the coating amount of aqueous polyethyleneimine might be 0.10-0.18 g/m<2>.

A predetermined printing was performed on the surface of the primer layer using a digital printer (manufactured by HP, Indigo20000 Digital Printer for Labels and Packages). As the electrostatic ink composition, an electrostatic ink composition (HP Indigo Electro Ink) containing a thermoplastic resin containing a copolymer of ethylene acrylic acid and ethylene methacrylic acid was used. As the color of the electrostatic ink composition, as shown in Table 1, yellow (Y), magenta (M) and cyan (C) were used. A plurality of samples having different colors and ink coverage of the electrostatic ink composition were prepared. The ink coverage of each color and the sum thereof were as shown in Table 1. Each ink coverage was adjusted by setting the digital printer. As shown in Table 1, the total ink coverage was 100 to 160%.

Aliphatic polyester polyol (manufactured by Mitsui Chemicals, Inc., trade name: Takelac A626, hereinafter sometimes referred to as "(A)") as a main agent, polyisocyanate (manufactured by Mitsui Chemicals, Inc., trade name: Takenate A50, hereinafter referred to as "(A)") (B)”), 3',4'-epoxycyclohexylmethyl-3,4epoxycyclohexanecarboxylate as an epoxy compound (hereinafter sometimes referred to as "C"), and Ethyl acetate was blended as a solvent to prepare an adhesive composition having a solid content concentration of 36.5% by mass. The structure of this epoxy compound is as showing to following formula (1). The compounding ratio (mass basis) of each component on a mass basis was (A) : (B) : (C) = 8 : 1 : 0.28.

The adhesive composition prepared as described above was applied to the printed surface on which the electrostatic ink composition was printed using a dry lamination apparatus to form an adhesive layer. The application amount of the adhesive composition was 4.0 g/m 2 .

[Formula 2]

A nylon film and an unstretched polypropylene film were bonded together with a commercially available adhesive to prepare a laminated film. Using the dry lamination apparatus, the nylon film and the adhesive layer were bonded together so that the adhesive layer on the base film and the nylon film of the laminated film faced each other to obtain a laminate. The curing time (aging) was 2 days at 40°C.

[Measurement of heat seal and color difference]

Using a spectrophotometer (manufactured by X-rite, trade name: eXact), lightness (L ^* ), hue and chroma (a ^* , b ^* ) on the surface of the base film (alumina-deposited PET film) of one laminated body ) was measured.

Thereafter, heating and pressurization were performed using a heat sealer under heat seal conditions at a temperature of 220°C, a pressure of 0.2 MPa, and a time of 1.5 seconds. After heating and pressurizing, the lightness (L ^* ), hue and chroma (a ^* , b ^* ) of the surface of the base film of the laminate were measured with a spectrophotometer again using a spectrophotometer. At this time, the above measurement was performed on the same surface and at the same position before and after heating and pressurization. The color difference (ΔE) was calculated from the difference in lightness (ΔL ^* ) before and after heating and pressurization and the difference in hue and chroma (Δa ^* , Δb ^* ) according to the above formula (A). The results were as shown in Table 1.

(Examples 1-2 to 1-6)

A laminate was manufactured in the same manner as in Example 1-1, except that the color and coverage of the electrostatic ink composition to be printed on the surface of the primer layer were changed as shown in Table 1. Then, heating and pressurization by a heat sealer were performed in the same manner as in Example 1-1, and the color difference (ΔE) before and after heating and pressurization was determined. The results were as shown in Table 1.

(Comparative Examples 1-1 to 1-6)

When preparing the adhesive composition, except that the epoxy compound (component (C)) was not blended, a laminate was prepared in the same manner as in Examples 1-1 to 1-6, and heating and pressurization were performed with a heat sealer did Then, the color difference (ΔE) before and after heating and pressurization was determined in the same manner as in Examples 1-1 to 1-6. The results were as shown in Table 2.

As shown in Tables 1 and 2, the color difference (ΔE) of the laminates of Examples 1-1 to 1-6 before and after heating and pressurization was sufficiently smaller than that of Comparative Examples 1-1 to 1-6. Thus, it was confirmed that the laminates of Examples 1-1 to 1-6 can sufficiently suppress discoloration caused by heating and pressurization.

(Example 1-7)

A laminate was manufactured in the same manner as in Example 1-1, except that the ink coverage by the electrostatic ink composition was set to Y: 20%, M: 20%, and C: 20%. Then, heating and pressurization were performed under heat sealing conditions at a temperature of 220°C, a pressure of 0.2 MPa, and a time of 1.5 seconds. The surface before and after heating and pressing was observed under an optical microscope at 100 times magnification. In an area of 1.0 mm × 1.0 mm arbitrarily selected from the observation image, the number of discoloration points (those with a circumscribed circle diameter of 20 μm or more) generated by heating and pressing were counted. The results were as shown in Table 3.

(Example 1-8)

Heating and pressurization were carried out in the same manner as in Examples 1-7, except that the heat seal conditions were set to a temperature of 240 ° C., a pressure of 0.2 MPa, and a time of 1.5 seconds. It counted in the same way as in 1-7. The results were as shown in Table 3.

(Comparative Example 1-7)

A laminate was manufactured in the same manner as in Comparative Example 1-1, except that the ink coverage by the electrostatic ink composition was set to Y: 20%, M: 20%, and C: 20%. Then, heat sealing was performed under the same heat sealing conditions as in Example 1-7, heating and pressurization were performed, and the number of discoloration points generated by heating and pressurization was counted in the same manner as in Example 1-7. The results were as shown in Table 3.

Fig. 9(A) is an optical microscope photograph showing the surface (surface on the alumina-deposited PET film side) of the laminate of Example 1-7 before heating and pressurization at a magnification of 100 times. Fig. 9(B) is an optical microscope photograph showing the surface of the layered product of Example 1-7 after heating and pressurization at a magnification of 100 times. As shown in Table 3 and Fig. 9, in Examples 1-7 and 1-8, discoloration points hardly occurred due to heat sealing.

Fig. 10(A) is an optical microscope photograph showing the surface (surface on the alumina-deposited PET film side) of the laminate of Comparative Example 1-7 before heating and pressing, magnified 100 times. Fig. 10(B) is an optical microscope photograph showing the surface of the layered product of Comparative Example 1-7 after heating and pressurization at a magnification of 100 times. As shown in Table 3 and Fig. 10, in Comparative Example 1-7, many discoloration points occurred due to heat sealing. As a result, it was confirmed that discoloration occurred.

From the results of the examples and comparative examples described above, it was confirmed that discoloration accompanying heat sealing can be suppressed by using an adhesive composition containing a polyol, a polyisocyanate, and an epoxy compound. It is thought that the improvement in the strength of the electrostatic ink composition and the improvement in the adhesive strength between the layers contribute to the factors that suppress discoloration in this way. These improving effects are also shown in Examples 2-4 to 2-20 described later.

(Example 2-1)

[Production of Laminate]

As a base film, a nylon film (manufactured by Unitica Co., Ltd., trade name: Emblem ONM, thickness: 15 µm) was prepared. A water-based primer resin (resin containing polyethyleneimine, manufactured by Michelman, trade name: DP050) was applied to one side of the nylon film to form a primer layer. At this time, the coating was applied so that the coating amount of the aqueous primer resin was 0.10 to 0.18 g/m 2 .

Using a digital printer (manufactured by HP, Indigo20000 Digital Printer for Labels and Packages), printing was performed on the surface of the primer layer to form an electrostatic ink layer. As the electrostatic ink composition, an electrostatic ink composition (HP Indigo Electro Ink) containing a thermoplastic resin containing a copolymer of ethylene acrylic acid and ethylene methacrylic acid was used. As the color of the electrostatic ink composition, black was used. The ink coverage was set to 200% by the setting of the digital printer.

Aliphatic polyester polyol (manufactured by Mitsui Chemicals, Inc., trade name: Takelac A626, hereinafter sometimes referred to as “component (A)”) as a main agent, polyisocyanate (manufactured by Mitsui Chemicals, Inc., trade name: Takenate A50, hereinafter) as a curing agent Sometimes referred to as "component (B)"), 3',4'-epoxycyclohexylmethyl-3,4epoxycyclohexanecarboxylate as an epoxy compound (hereinafter also referred to as "component (C)" ), and ethyl acetate as a solvent to prepare an adhesive composition having a solid content concentration of 36.5% by mass. The structure of this epoxy compound is as showing to following formula (1). The compounding ratio (mass basis) of each component on a mass basis was (A) component: (B) component: (C) component = 8:1:0.28.

The adhesive composition prepared as described above was applied to the printed surface on which the electrostatic ink composition was printed using a dry lamination apparatus to form an adhesive layer. The application amount of the adhesive composition was 4.0 g/m 2 .

[Formula 3]

Using the dry lamination device, the adhesive layer on the base film and the linear low-density polyethylene film (manufactured by Mitsui Chemicals Tocello Co., Ltd., trade name: T.U.X-FCS, thickness: 60 μm) serving as the sealant layer face each other, The adhesive layer and the linear low-density polyethylene film were bonded together. The curing time (aging) was 2 days at 40°C. In this way, a laminate having a laminated structure as shown in Fig. 2 was obtained.

[Preparation of evaluation sample, and evaluation of discoloration and welding state]

A spout made of polyethylene having a shape as shown in Figs. 6 to 8 was prepared. The welded portion of the spout was brought into contact with the sealant layer, and the welded portion was placed between the pair of laminates to obtain a sample for evaluation. Using a thermal inclination tester (manufactured by Toyo Seiki Seisakusho, device name: HG-3), heating and pressurization for 1.0 seconds were performed under the conditions of temperature: 200°C and pressure: 0.3 MPa to weld the welded portion and the sealant layer. Pressurization was performed along the direction in which the welded portion and the sealant layer faced each other. With respect to the set welding area (75 mm 2 ), the area of the discolored portion visually detected by ink bleeding was calculated. The results were as shown in Table 4. Moreover, the welding state of the welded part of a spout and the sealant layer was also evaluated. A case where the welded portion of the spout and the sealant layer were firmly sealed was evaluated as "A", and a case where the sealant was insufficient was evaluated as "B". The results were as shown in Table 4.

(Example 2-2)

A layered product and an evaluation sample were prepared and evaluated in the same manner as in Example 2-1, except that cyan and magenta were overprinted and used as the color of the electrostatic ink composition, and that the ink coverage was 300%. did The results were as shown in Table 4.

(Example 2-3)

A layered product and an evaluation sample were prepared and evaluated in the same manner as in Example 2-1, except that white was used as the color of the electrostatic ink composition and that the ink coverage was 100%. The results were as shown in Table 4.

(Comparative Example 2-1)

A layered product and an evaluation sample were prepared and evaluated in the same manner as in Example 2-1, except that the epoxy compound (component (C)) was not blended when preparing the adhesive composition. The results were as shown in Table 4.

(Comparative Example 2-2)

A layered product and an evaluation sample were prepared and evaluated in the same manner as in Example 2-2, except that the epoxy compound (component (C)) was not blended when preparing the adhesive composition. The results were as shown in Table 4.

(Comparative Example 2-3)

A layered product and an evaluation sample were prepared and evaluated in the same manner as in Example 2-3, except that the epoxy compound (component (C)) was not blended when preparing the adhesive composition. The results were as shown in Table 4.

Fig. 11(A) is a photograph showing the appearance of the sample for evaluation after welding in Example 2-1. 11(B) is a photograph showing the appearance of the sample for evaluation after welding in Example 2-2. As shown in Fig. 11, discoloration did not occur at all in Examples 2-1 and 2-2. Also in Example 2-3, discoloration detectable with the naked eye did not occur at all, as in Examples 2-1 and 2-2. Further, in all of the evaluation samples of Examples 2-1 to 2-3, the welded portion of the spout and the sealant layer were firmly welded.

Fig. 12(A) is a photograph showing the appearance of the sample for evaluation after welding in Comparative Example 2-1. 12(B) is a photograph showing the appearance of the sample for evaluation after welding in Comparative Example 2-2. As shown in Fig. 12, in Comparative Examples 2-1 and 2-2, ink bleeding occurred, and discoloration occurred obviously. Also in Comparative Example 2-3, ink bleeding occurred and discoloration occurred. In addition, in all of the samples for evaluation of Comparative Examples 2-1 to 2-3, the welded portion of the spout and the sealant layer were firmly welded.

(Comparative Examples 2-4 to 2-7)

Except for changing the temperature at the time of welding the welded part of the spout and the sealant layer as shown in Table 5, in the same manner as in Comparative Example 2-1, a laminate and an evaluation sample were prepared and welded evaluation was performed. . The results were as shown in Table 5. In Table 5, the results of Comparative Example 2-1 described above were also shown together.

13(A) is a photograph showing the appearance of the sample for evaluation after welding in Comparative Example 2-4. 13(B) is a photograph showing the appearance of the sample for evaluation after welding in Comparative Example 2-5. 14(A) is a photograph showing the appearance of the sample for evaluation after welding in Comparative Example 2-6. 14(B) is a photograph showing the appearance of the sample for evaluation after welding in Comparative Example 2-7. As shown in Table 5, Fig. 13 and Fig. 14, it was confirmed that the discoloration area can be reduced by lowering the welding temperature, but when the welding temperature is lowered too much, the welding between the welded portion and the sealant layer becomes insufficient.

From the results of the examples and comparative examples described above, it was confirmed that discoloration caused by ink bleeding during welding can be suppressed by using an adhesive composition containing a polyol, a polyisocyanate, and an epoxy compound. As a factor capable of suppressing discoloration in this way, it is considered that heat resistance is improved by aggregation and adhesion of the electrostatic ink composition. In order to verify this, the following experiment was conducted.

(Example 2-4)

[Preparation of Adhesive Composition and Laminate]

As a base film, a polyethylene terephthalate film (PET film, thickness: 12 μm) was prepared. A primer layer was formed by applying the same water-based primer resin as in Example 2-1 to one side of the PET film. The application amount of the water-based primer resin was also the same as in Example 2-1.

Using the digital printer used in Example 2-1, predetermined printing was performed on the surface of the primer layer. As the electrostatic ink composition, an electrostatic ink composition (HP Indigo Electro Ink) containing a thermoplastic resin containing a copolymer of ethylene acrylic acid and ethylene methacrylic acid was used. As the color of the electrostatic ink composition, as shown in Table 6, white (W), yellow (Y), magenta (M), and cyan (C) were used. A plurality of samples having different colors and ink coverage of the electrostatic ink composition were prepared. The ink coverage of each color and the sum thereof were as shown in Table 6. As shown in Table 6, the total ink coverage was 200 to 500%.

The same adhesive composition as in Example 2-1 was prepared, and the adhesive composition was applied to the printed surface in the same procedure as in Example 2-1 to form an adhesive layer. The application amount of the adhesive composition was 4.0 g/m 2 .

A laminated film having an aluminum foil (manufactured by Toyo Aluminum Co., Ltd., thickness: 7 μm), a nylon film and an unstretched polypropylene film in this order was prepared. Using the same dry lamination apparatus as in Example 2-1, the aluminum foil and the adhesive layer were bonded together so that the adhesive layer on the base film and the aluminum foil of the laminated film faced each other to obtain a laminate. The curing time (aging) was 2 days at 40°C.

[Measurement of Adhesion Strength (Room Temperature)]

Based on JIS K 6854-1:1999, the adhesive strength of the manufactured laminate was measured. Specifically, the manufactured laminate was cut to a width of 15 mm to obtain a sample for measurement. After peeling off the interlayer at the end of the sample for measurement, the peel strength between the layers of the laminate was measured using a tensile tester under conditions of an angle: 90°, a tensile speed: 300 mm/min, and room temperature. This peel strength was made into the adhesive strength at normal temperature (20 degreeC). The measurement results were as shown in Table 6.

(Examples 2-5 to 2-9)

Except having changed the formulation of the adhesive composition as shown in Table 6 and Table 7, it carried out similarly to Example 2-4, manufactured the laminated body, and measured the adhesive strength. The measurement results were as shown in Table 6 and Table 7.

(Example 2-10)

A two-component adhesive was prepared in which a first liquid composed of component (A) used in Example 2-1 and a second liquid composed of component (B) and component (C) were separately contained in a container. The 1st liquid and the 2nd liquid were mixed, and the adhesive composition of the formulation shown in Table 7 was prepared. Except having used this adhesive composition, it carried out similarly to Example 2-4, manufactured the laminated body, and measured the adhesive strength. The measurement results were as shown in Table 7.

(Comparative Example 2-8)

When preparing the adhesive composition, except not having mix|blended component (C), it carried out similarly to Example 2-4, manufactured the laminated body, and measured the adhesive strength. The measurement results were as shown in Table 7.

(Comparative Example 2-9)

Example 2, except that the epoxy compound of Formula (1) was applied to the printed surface on which the electrostatic ink composition was printed to form an epoxy coating layer, and the adhesive composition of Comparative Examples 2-8 was applied to this epoxy coating layer. In the same manner as in -4, a laminate was produced and the adhesive strength was measured. The coating amount of the epoxy coating layer was an amount corresponding to 0.53 parts by mass in the formulations shown in Table 7. The measurement results were as shown in Table 7.

In Tables 6 and 7, [(B)/(A)] × 100 column shows the blending amount (parts by mass) of component (B) relative to 100 parts by mass of component (A). In Tables 6 and 7, [(C)/(A)] × 100 column shows the blending amount (parts by mass) of component (C) relative to 100 parts by mass of component (A). In Tables 6 and 7, the column of "epoxy group/isocyanate group" shows the molar ratio of the epoxy group contained in component (C) to the isocyanate group contained in component (B).

As shown in Table 6 and Table 7, the laminates of Examples 2-4 to 2-10 in which the adhesive layer containing an epoxy compound and the printed surface are adhered, the adhesive layer containing no epoxy compound and the printed surface are adhered. It was confirmed that the adhesive strength was higher than that of the laminate of Comparative Example 2-8. Further, in Comparative Example 2-9, although relatively high adhesive strength was obtained, since an epoxy coating layer was formed in addition to the adhesive layer, the number of steps increased. Curing (aging) of the epoxy coating layer took two days, resulting in a decrease in productivity.

In the laminate of Comparative Example 2-8, the electrostatic ink layer and the primer layer were peeled off near the interface. In the laminate of Comparative Example 2-9, the electrostatic ink layer had cohesive failure. On the other hand, in the laminates of Examples 2-4 to 2-10, separation occurred at the interface between the electrostatic ink layer and the adhesive layer, and cohesive failure of the electrostatic ink layer was not observed. This suggests that the cohesive force and adhesive force of the electrostatic ink layer are improved. In Examples 2-4 to 2-10, the molar ratio of the isocyanate groups contained in component (B) to the hydroxyl groups in component (A) was in the range of 0.5 to 10.

Next, the adhesive strength, hot water adhesive strength, and seal strength of the laminates of Example 2-8 and Comparative Example 2-9 were measured. For the measurement, a total of 500% and 200% ink coverage were used. Details of the measurement procedure are as follows.

[Measurement of hot water adhesive strength]

The laminates of Example 2-8 and Comparative Example 2-9 were each cut to a width of 15 mm to obtain measurement samples. After peeling off the interlayer in the end part of the sample for measurement, peeling strength was measured using the tensile tester in the state which was immersed in 90 degreeC hot water. That is, it was set as peeling angle: free, tensile speed: 300 mm/min. Table 8 shows this peel strength as the hot water adhesive strength.

[Measurement of Seal Strength (Before Heat Treatment)]

Using a pair of laminates of Example 2-8, heat sealing was performed so that the unstretched polypropylene films overlapped with each other to form a sealed portion. In this way, the unstretched polypropylene films were welded together to prepare a sample for measurement having a width of 15 mm. Based on JIS K 7127:1999, the seal strength in the seal part of the manufactured measurement sample was measured. The measurement measured the peeling strength between heat seals using a tensile tester under conditions of a peeling angle: 90°, a tensile speed: 300 mm/min, and room temperature (20°C). This peeling strength was taken as the seal strength "before heat treatment". The measurement results were as shown in Table 8. Using the laminate of Comparative Example 2-10, the same sample for measurement was prepared, and the same measurement was performed. The measurement results were as shown in Table 8.

[Measurement of Seal Strength (After Boiling)]

The sample for measurement prepared in the above-mentioned “measurement of seal strength (before heat treatment)” was heated in water at 100° C. for 30 minutes. After that, the seal strength was measured in the same manner as in the above-described “measurement of seal strength (without heat treatment)”. The measurement result was as showing in the column of "after boiling" of Table 8.

[Measurement of seal strength after retort (120 ° C.)]

Retort heat treatment (120°C for 30 minutes) was performed on the sample for measurement prepared in the above-described "Measurement of Seal Strength (Before Heat Treatment)". Peel strength was measured using a tensile tester in the same manner as in "measurement of seal strength (before heat treatment)". The measurement result was as showing in the column of "120 degreeC x 30 minutes" of Table 8.

[Measurement of seal strength after retort (130 ° C.)]

The retort heat treatment (130°C x 30 minutes) of the sample for measurement prepared in the above-described "Measurement of Seal Strength (Before Heat Treatment)" was performed. Peel strength was measured using a tensile tester in the same manner as in "measurement of seal strength (without heat treatment)". The measurement result was as showing in the column of "130 degreeC x 30 minutes" of Table 8.

As shown in Table 8, the hot water adhesive strength of Example 2-8 was significantly higher than that of Comparative Example 2-9. Moreover, it was confirmed that Example 2-8 was superior to Comparative Example 2-9 also in terms of seal strength. In particular, the seal strength of Example 2-8 was sufficiently high even after boiling, whereas the seal strength of Comparative Example 2-9 significantly decreased after boiling. It was confirmed that the adhesive strength and seal strength of the laminate of Comparative Example 2-9 significantly decreased when heated in the presence of moisture.

(Example 2-11)

[Preparation of Adhesive Composition and Laminate]

As a base film, a polyethylene terephthalate film (PET film, thickness: 12 μm) was prepared. A primer layer was formed by applying the same water-based primer resin as in Example 2-1 to one side of the PET film. The application amount of the water-based primer resin was also the same as in Example 2-1.

Using the digital printer used in Example 2-1, predetermined printing was performed on the surface of the primer layer. As the color of the electrostatic ink composition, white (W), yellow (Y), magenta (M), and cyan (C) were used. As the ink coverage, those of W200% and those of C100% + M100% + Y100% + W200% were prepared. In Table 9, the former was set to "ink coverage (1)", and the latter was set to "ink coverage (2)." In this way, two types of samples having different ink coverage of the electrostatic ink composition were prepared.

The same adhesive composition as in Example 2-1 was prepared, and the adhesive composition was applied to the printed surface in the same procedure as in Example 2-1 to form an adhesive layer. The application amount of the adhesive composition was 4.0 g/m 2 .

The laminated film (laminated film obtained by bonding a nylon film and an unstretched polypropylene film together with a commercially available adhesive) used in Example 2-4 was bonded to the adhesive layer of the base film in the same manner as in Example 2-4, and laminated. got a sieve The curing time (aging) was set at 40°C for 2 days.

The seal strength (before heat treatment) and seal strength (after boiling) of the laminate thus obtained were measured. The measurement results were as shown in Table 9. In addition, adhesive strength (before heat treatment) and hot adhesive strength (120°C) were measured in the following procedure.

Using a pair of laminates of Example 2-11, heat sealing was performed so that the unstretched polypropylene films overlapped with each other, to prepare a three-way envelope having a sealed portion. Water was enclosed in this three-way envelope. After that, retort heat treatment (120°C for 30 minutes) was performed using a retort processing device (manufactured by Hisaka Manufacturing Co., Ltd.). After the retort heat treatment, it was cut to a width of 15 mm, a sample of the seal portion was taken, and the interlayer strength of the electrostatic ink layer and the layer in contact with the electrostatic ink layer was measured. The measured peel strength is shown in the column of "Hot Adhesion Strength (120°C)" in Table 9. In addition, in Table 9, the adhesive strength before retort heat treatment was also shown.

(Examples 2-12 to 2-15)

When preparing the adhesive composition, except having changed the compounding quantity of polyisocyanate (B) as shown in Table 9, it carried out similarly to Example 2-11, and manufactured the laminated body. The manufactured laminate was evaluated in the same manner as in Example 2-11. The evaluation results were as shown in Table 9.

(Comparative Example 2-10)

A laminate was manufactured in the same manner as in Comparative Example 2-8, except that the lamination of the printed surface on which the electrostatic ink composition was printed was carried out with a hand laminator without using a dry lamination device. The color and ink coverage of the electrostatic ink composition were as shown in Table 9. The manufactured laminate was evaluated in the same manner as in Example 2-11. The evaluation results were as shown in Table 9.

As shown in Table 9, in each Example, it was confirmed that high adhesive strength and seal strength were obtained even under heating conditions. In addition, it was confirmed that the hot adhesive strength (120 ° C.) and the seal strength (before heat treatment and after boiling) can be sufficiently increased by adjusting the blending ratio of component (B) to component (A). On the other hand, in Comparative Example 2-10 in which the component (C) was not used, it was confirmed that the adhesive strength and seal strength significantly decreased when exposed to high-temperature hot water treatment conditions. In Examples 2-11 to 2-15, the molar ratio of the isocyanate groups contained in component (B) to the hydroxyl groups contained in component (A) was in the range of 0.5 to 10.

(Examples 2-16 to 2-20)

Aliphatic polyester polyol (A1) (Takelac A525, manufactured by Mitsui Chemicals, Inc.), polyisocyanate (B1) (Takenate A52, manufactured by Mitsui Chemicals, Inc.), and 3',4'-epoxycyclohexyl as epoxy compound (C) An adhesive composition was prepared by blending methyl-3,4 epoxycyclohexane carboxylate. The blending ratio was as shown in Table 10. Except having used such an adhesive composition, it carried out similarly to Examples 2-11 - 2-15, and manufactured and evaluated the laminated body. The evaluation results were as shown in Table 10.

(Comparative Example 2-11)

As a polyol, aliphatic polyester polyol (A1) (Mitsui Chemical Co., Ltd. Takelac A525) and polyisocyanate (B1) (Mitsui Chemical Co., Ltd. Takenate A52) were blended to prepare an adhesive composition. The blending ratio was as shown in Table 10. A laminate was produced and evaluated in the same manner as in Comparative Example 2-10 except that such an adhesive composition was used. The evaluation results were as shown in Table 10.

As shown in Table 10, it was confirmed that high adhesive strength and seal strength were obtained in each Example even when the combination of aliphatic polyester polyol and polyisocyanate was changed. Further, it was confirmed that the seal strength (without heat treatment and after boiling) and hot adhesive strength (120°C) can be sufficiently increased by adjusting the blending ratio of polyisocyanate (B1) to aliphatic polyester polyol (A1). On the other hand, in Comparative Example 2-11 in which the epoxy compound (C) was not used, it was confirmed that the adhesive strength and seal strength significantly decreased when exposed to high-temperature hydrothermal treatment conditions. In Examples 2-16 to 2-20, the molar ratio of the isocyanate groups contained in the polyisocyanate (B1) to the hydroxyl groups contained in the aliphatic polyester polyol (A1) was in the range of 0.5 to 10.

(Example 3-1)

[Production of Laminate]

As a base film, an alumina vapor deposition PET film (trade name: GLARH12, thickness: 12 µm, manufactured by Topan Printing Co., Ltd.) was prepared. A water-based primer resin (resin containing polyethyleneimine, manufactured by Michelman, trade name: DP050) was applied to the alumina deposition surface to form a primer layer. It applied so that the coating amount of aqueous polyethyleneimine might be 0.10-0.18 g/m<2>.

A predetermined printing was performed on the surface of the primer layer using a digital printer (manufactured by HP, Indigo20000 Digital Printer for Labels and Packages). As the electrostatic ink composition, an electrostatic ink composition (HP Indigo Electro Ink) containing a thermoplastic resin containing a copolymer of ethylene acrylic acid and ethylene methacrylic acid was used. As the color of the electrostatic ink composition, as shown in Table 11, yellow (Y), magenta (M) and cyan (C) were used. A plurality of samples having different colors and ink coverage of the electrostatic ink composition were prepared. The ink coverage was as shown in Table 11. Each ink coverage was adjusted by setting the digital printer. As shown in Table 11, the total ink coverage was 200 to 400%.

Aliphatic polyester polyol (manufactured by Mitsui Chemicals, Inc., trade name: Takelac A626, hereinafter sometimes referred to as "(A)") as a main agent, polyisocyanate (manufactured by Mitsui Chemicals, Inc., trade name: Takenate A50, hereinafter referred to as "(A)") (B)”), 3',4'-epoxycyclohexylmethyl-3,4epoxycyclohexanecarboxylate as an epoxy compound (hereinafter sometimes referred to as "C"), and Ethyl acetate was blended as a solvent to prepare an adhesive composition having a solid content concentration of 36.5% by mass. The structure of this epoxy compound is as showing to following formula (1). The compounding ratio (mass basis) of each component on a mass basis was (A) : (B) : (C) = 8 : 1 : 0.28.

The adhesive composition prepared as described above was applied to the printed surface on which the electrostatic ink composition was printed using a dry lamination apparatus to form an adhesive layer. The application amount of the adhesive composition was 4.0 g/m 2 .

[Formula 4]

A nylon film and an unstretched polypropylene film were bonded together with a commercially available adhesive to prepare a laminated film. Using the dry lamination apparatus, the nylon film and the adhesive layer were bonded together so that the adhesive layer on the base film and the nylon film of the laminated film faced each other to obtain a laminate. The curing time (aging) was 2 days at 40°C.

(Example 3-2, 3-3)

A laminate was prepared in the same manner as in Example 3-1, except that the color and ink coverage of the electrostatic ink composition were changed as shown in Table 11.

(Comparative Examples 3-1 to 3-3)

When preparing the adhesive composition, the laminate was prepared in the same manner as in Examples 3-1 to 3-3, except that the epoxy compound (component (C)) was not blended.

<Evaluation of adhesive strength of laminated body>

For each of the laminates prepared in Examples 3-1 to 3-3 and Comparative Examples 3-1 to 3-3, adhesive strength was measured based on the description of JIS K 6854-1:1999. Specifically, the previously prepared layered product was cut to a width of 15 mm to obtain a measurement sample. After peeling off the interlayer at the end of the measurement sample, the peel strength between the layers of the laminate was measured using a tensile tester under conditions of an angle: 90°, a tensile speed: 300 mm/min, and room temperature. This peel strength was taken as the adhesive strength (laminate strength) at normal temperature (20 degreeC). The measurement results were as shown in Table 11.

<Evaluation of tear property of laminated body>

For each of the laminates prepared in Examples 3-1 to 3-3 and Comparative Examples 3-1 to 3-3, the four sides were sealed by heat sealing the sealant layers facing each other (as shown in FIG. 4). packaging bag) was obtained. An I-shaped notch was formed on one sealed side to prepare a sample for evaluation. Tearability was evaluated for each evaluation sample by opening the packaging bag starting from the notch and visually confirming the appearance at that time. Tearability evaluation was performed according to the following evaluation criteria based on the cleanness of the opened cross section.

A: No peeling between the layers of the laminate was observed, and there was little fluctuation of the tear surface.

B: Although peeling between the layers of the laminate was not observed, the tear surface was fluctuating.

C: Peeling between layers of the laminate was observed, and the tear surface was fluctuating.

A result is shown in Table 11. For reference, an example of the evaluation criteria A is shown in Fig. 15 and an example of the evaluation criteria C is shown in Fig. 16 . In Fig. 15, the tear point is denoted by A, the tear end of the laminate on the front side of the pair of laminates is denoted by A1, and the tear end of the laminate on the back side is denoted by A2. As shown in Fig. 15, in the packaging bag of Example 3-1, A1 and A2 were almost identical, and it was confirmed that it could be opened cleanly. In Fig. 16, the tear point is denoted by B, the tear end of the laminate on the front side of the pair of laminates is denoted by B1, and the tear end of the laminate on the back side is denoted by B2. As shown in Fig. 16, in the packaging bag of Comparative Example 3-1, it was confirmed that the positions of B1 and B2 were largely displaced from each other. As shown by C in FIG. 16 , such a misalignment is presumed to be because peeling occurred on the printed surface of the laminate and the like, and the external force of tearing could not be sufficiently used for tearing the base film.

(Examples 3-4 to 3-6)

Except for using a laminated film prepared by bonding an aluminum thin film, a nylon film, and an unstretched polypropylene film together with a commercially available adhesive in this order, instead of a laminated film in which a nylon film and an unstretched polypropylene film are bonded together with a commercially available adhesive, Laminates were prepared in the same manner as in Examples 3-1 to 3-3. Each obtained laminate was evaluated for adhesive strength and tear property in the same manner as in Example 3-1. A result is shown in Table 12.

(Comparative Examples 3-4 to 3-6)

Except for using a laminated film prepared by bonding an aluminum thin film, a nylon film, and an unstretched polypropylene film together with a commercially available adhesive in this order, instead of a laminated film in which a nylon film and an unstretched polypropylene film are bonded together with a commercially available adhesive, Laminates were prepared in the same manner as in Comparative Examples 3-1 to 3-3. Each obtained laminate was evaluated for adhesive strength and tear property in the same manner as in Example 3-1. A result is shown in Table 12.

(Examples 3-7 to 3-9)

In the same manner as in Examples 3-1 to 3-3, laminates were prepared.

(Comparative Examples 3-7 to 3-9)

Laminates were prepared in the same manner as in Comparative Examples 3-1 to 3-3.

<Measurement of rate of change in adhesive strength before and after heat treatment for laminated body>

From the laminates prepared in Examples 3-7 to 3-9 and Comparative Examples 3-7 to 3-9, two measurement samples each cut to a width of 15 mm were prepared. In the same manner as in Example 3-1, the adhesive strength X of one measurement sample was measured. Next, the other measurement sample was subjected to retort heat treatment at 120°C for 30 minutes. Specifically, with respect to each of the laminates prepared in Examples 3-7 to 3-9 and Comparative Examples 3-7 to 3-9, sealant layers were opposed to each other and heat-sealed to obtain a packaging bag sealed on three sides. Next, a four-way seal bag (package) was prepared by putting 100 g of water as a packing material and sealing the remaining side. After heating and sterilizing the obtained package using a retort sterilization tester at a temperature of 120°C and a treatment time of 30 minutes, the package was opened and a measurement sample cut to a width of 15 mm was obtained. In the same manner as in Example 3-1, the adhesive strength Y of the measurement sample after the retort heat treatment described above was measured. From the measurement results, the rate of change in adhesive strength [100(Y - X)/X] was calculated. A result is shown in Table 13.

<Evaluation of tear property of laminated body>

About the laminated bodies prepared in Examples 3-7 to 3-9 and Comparative Examples 3-7 to 3-9, tear properties were evaluated in the same manner as in Example 3-1. A result is shown in Table 13.

(Examples 3-10 to 3-11)

Laminates were prepared in the same manner as in Examples 3-4 to 3-6. In the same manner as in Example 3-7, the adhesive strengths X and Y of each laminate and the rate of change in adhesive strength [100(Y - X)/X] were determined, and the tear property was evaluated. A result is shown in Table 14.

(Comparative Examples 3-10 to 3-11)

In the same manner as in Comparative Examples 3-4 to 3-6, laminates were prepared. In the same manner as in Example 3-7, the adhesive strengths X and Y of each laminate and the rate of change in adhesive strength [100(Y - X)/X] were determined, and the tear property was evaluated. A result is shown in Table 14.

From the results of the examples and comparative examples described above, it was confirmed that the adhesive strength and the tear resistance can be improved by using an adhesive composition containing a polyol, a polyisocyanate, and an epoxy compound. It is considered that the improvement of the strength of the electrostatic ink composition and the improvement of the bonding strength between the layers are contributing to the improvement of the adhesive strength and the tear resistance. Such effects are also shown in the examples described above (for example, Examples 2-8 in Table 8).

ADVANTAGE OF THE INVENTION According to this indication, it is possible to provide a laminate capable of sufficiently suppressing discoloration that occurs during heat sealing, while having a printing surface by a digital printer. Moreover, it is possible to provide a packaging bag and a package in which discoloration is sufficiently suppressed while having a printing surface by a digital printer.

Further, according to the present disclosure, a laminate having an electrostatic ink layer composed of an electrostatic ink composition and having excellent heat resistance is provided. Further, a pouch with a spout capable of sufficiently suppressing discoloration of a welded portion while having an electrostatic ink layer composed of an electrostatic ink composition, a manufacturing method thereof, and a package are provided. In addition, a packaging material preferably used as a pouch main body of a pouch with a spout is provided.

Further, according to the present disclosure, printing is performed by a digital printer, and peeling at the interface between the electrostatic ink layer and the primer layer and at the interface between the electrostatic ink layer and the adhesive layer is suppressed at the time of opening or tearing, while having a printed surface. A packaging bag can be provided.

10: base film
20: sealant film (sealant layer)
30: adhesive layer
40: primer layer
50, 51: electrostatic ink layer
52: printing side
53 : dot
55: discoloration point
100: packaging bag
101, 401: seal part
102: receiving part
110: packaging bag
120: Opening means
121: half cut line
124: processing unit for easy opening
200: package
202: packing material
300, 310: laminate
300A: surface
400: Pouch with spout attached
402: Visi part
410: pouch body part
420: spout
421: cover body
422: Tongbu
423: flange
424: flange
426: welding part
426r: welding rib
428: Euro
440: packaging material
450: welding part

Claims (27)

A laminate comprising a base film, an adhesive layer, and a sealant film in this order, and having a printing surface of an electrostatic ink composition bonded to the adhesive layer,
The adhesive layer is composed of at least one of an adhesive composition containing a polyol, a polyisocyanate and an epoxy compound and a cured product thereof,
A laminate having a color difference (ΔE) of less than 3.0 before and after heating and pressurizing the sealant film on the printing surface under heat-sealing conditions at a temperature of 220° C., a pressure of 0.2 MPa, and a time of 1.5 seconds, as determined by the following formula (A). .

[In the above formula (A), ΔL ^* represents the difference in brightness before and after heating and pressurization under the above heat-sealing conditions, and Δa ^* and Δb ^* are both before and after heating and pressurization under the above heat-sealing conditions. Indicates the difference in color and saturation.] According to claim 1,
The laminate, wherein the number of discoloration points having a size of 20 μm or more generated on the printed surface by heating and pressing under the heat-sealing conditions is 10 or less per 1 mm 2 . A laminate comprising a base film, an adhesive layer, and a sealant film in this order, and having a printing surface of an electrostatic ink composition bonded to the adhesive layer,
The adhesive layer is composed of at least one of an adhesive composition containing a polyol, a polyisocyanate and an epoxy compound and a cured product thereof,
The number of discoloration points having a size of 20 μm or more generated when the sealant film on the printing surface is heated and pressurized under heat sealing conditions at a temperature of 220 ° C., a pressure of 0.2 MPa, and a time of 1.5 seconds is 10 or less per 1 mm. sifter. According to any one of claims 1 to 3,
The polyol includes an aliphatic polyester polyol, and the epoxy compound includes one having epoxy groups at both ends. According to any one of claims 1 to 4,
The laminated body in which the said epoxy compound contains a bifunctional alicyclic epoxy compound. According to any one of claims 1 to 5,
Wherein the polyisocyanate comprises a xylylene diisocyanate derivative. a pair of laminates;
An accommodating portion for accommodating a to-be-packaged object between the pair of laminates;
A seal portion configured by heat sealing each sealant film of the pair of laminates,
The packaging bag in which the said pair of laminated body contains the laminated body in any one of Claims 1-6. A package comprising the packaging bag according to claim 7 and a packing material packaged in the packaging bag. A step of printing an electrostatic ink composition on one side of a base film to obtain a printed surface;
A step of obtaining a laminate by adhering the printed surface and a base material including a sealant film using an adhesive composition containing a polyol, a polyisocyanate, and an epoxy compound;
A laminate having a color difference (ΔE) of less than 3.0 before and after heating and pressurizing the sealant film on the printing surface under heat-sealing conditions at a temperature of 220° C., a pressure of 0.2 MPa, and a time of 1.5 seconds, as determined by the following formula (A). manufacturing method.

[In the above formula (A), ΔL ^* represents the difference in brightness before and after heating and pressurization under the above heat-sealing conditions, and Δa ^* and Δb ^* are both before and after heating and pressurization under the above heat-sealing conditions. Indicates the difference in color and saturation.] A step of printing an electrostatic ink composition on one side of a base film to obtain a printed surface;
A step of obtaining a laminate by adhering the printed surface and a base material including a sealant film using an adhesive composition containing a polyol, a polyisocyanate, and an epoxy compound;
The number of discoloration points having a size of 20 μm or more generated when the sealant film on the printing surface is heated and pressurized under heat sealing conditions at a temperature of 220 ° C., a pressure of 0.2 MPa, and a time of 1.5 seconds is 10 or less per 1 mm. How to make a sieve. A laminate for a pouch with a spout comprising a base film, an adhesive layer, and a sealant layer bonded to a spout in this order, and an electrostatic ink layer bonded to the adhesive layer, comprising:
The adhesive layer is composed of at least one of an adhesive composition containing a polyol, a polyisocyanate, and an epoxy compound, and a cured product thereof. According to claim 11,
A laminate having a primer layer between the base film and the electrostatic ink layer. According to claim 11 or 12,
The polyol includes an aliphatic polyester polyol, and the epoxy compound includes one having epoxy groups at both ends. According to any one of claims 11 to 13,
The laminated body in which the said epoxy compound contains a bifunctional alicyclic epoxy compound. According to any one of claims 11 to 14,
Wherein the polyisocyanate comprises a xylylene diisocyanate derivative. at least one laminate;
A seal portion configured by heat sealing sealant layers in the at least one laminate;
A pouch with a spout, wherein the sealant layers face each other and have an unsealed portion to which the spout is welded, and wherein the at least one laminate includes the laminate according to any one of claims 11 to 15. dragon packaging. A pouch with a spout having a pouch body and a spout,
The pouch body has at least one laminate, a sealing portion in which sealant layers in the at least one laminate are bonded together, and a housing portion for accommodating a packing material;
The spout is welded to the sealant layer of the laminate in the pouch body,
A pouch with a spout, wherein the at least one laminate includes the laminate according to any one of claims 11 to 15. A package comprising the spout-attached pouch according to claim 17 and a packaging material accommodated in the pouch. An adhesive layer composed of a base film, an adhesive composition containing a polyol, polyisocyanate, and an epoxy compound and at least one of a cured product thereof, and a sealant layer in this order, and an electrostatic ink layer adhered to the adhesive layer. A step of manufacturing at least one laminated body;
A step of obtaining a packaging material by forming a sealing portion formed by heat-sealing sealant layers of the at least one laminate and a non-sealing portion in which the sealant layers face each other;
A method for producing a pouch with a spout, comprising a step of inserting a welded portion of a spout into the non-sealed portion of the packaging material and welding the sealant layer between the welded portion and the non-sealed portion. According to claim 19,
A method of manufacturing a pouch with a spout, wherein welding of the sealant layer in the welded portion and the non-sealed portion is performed by heating at 150°C or higher. A packaging bag composed of a laminate having a base film, a primer layer, an electrostatic ink layer, an adhesive layer, and a sealant layer in this order,
The adhesive layer is composed of at least one of an adhesive composition containing a polyol, a polyisocyanate and an epoxy compound and a cured product thereof,
The ink coverage of the electrostatic ink layer is 500% or less,
The packaging bag, wherein the adhesive strength of the laminate is 2.0 N/15 mm or more. A packaging bag composed of a laminate having a base film, a primer layer, an electrostatic ink layer, an adhesive layer, and a sealant layer in this order,
The adhesive layer is composed of at least one of an adhesive composition containing a polyol, a polyisocyanate and an epoxy compound and a cured product thereof,
The ink coverage of the electrostatic ink layer is 100 to 400%,
When the adhesive strength of the laminate is X and the adhesive strength of the laminate after retort heat treatment at 120°C for 30 minutes is Y, the value of 100(Y - X)/X is greater than -30% , packaging bag. According to claim 21 or 22,
The polyol includes an aliphatic polyester polyol, and the epoxy compound includes one having epoxy groups at both ends, the packaging bag. According to any one of claims 21 to 23,
The epoxy compound comprises a bifunctional alicyclic epoxy compound, packaging bag. According to any one of claims 21 to 24,
The polyisocyanate includes a xylylene diisocyanate derivative, the packaging bag. 26. The method of any one of claims 21 to 25,
The packaging bag according to claim 1 , wherein an ink application amount on a main surface of the primer layer on the sealant layer side is 0.5 g/m 2 or more. 27. The method of any one of claims 21 to 26,
The packaging bag according to claim 1 , wherein the laminate further has a barrier layer between the adhesive layer and the sealant layer.

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