JP2024088105A - Inks, laminates including multi-layer films, and packaging materials - Google Patents

Abstract

[Problem] The object of the present invention is to provide a multilayer film having excellent film-forming properties even when the biomass ratio is increased using a plant-derived resin, a laminate having excellent adhesion between the printed layer, and a packaging material comprising these multilayer films or laminates. [Solution] The present invention provides a laminate comprising at least a first base material layer and a printed layer, characterized in that (1) the first base material layer has a surface layer (A), an intermediate layer (B), and a sealing layer (C), the surface layer (A) contains a propylene-based resin, the intermediate layer (B) contains biomass polyethylene, and the sealing layer (C) is a multilayer film containing a propylene-ethylene copolymer, and (2) the printed layer is a layer formed by printing with a liquid printing ink, and a packaging material comprising said laminate. [Selected Figures] None

Description

The present invention relates to a laminate in which at least a first base layer and a printed layer are laminated. It also relates to a packaging product, such as a packaging material, that includes the laminate.

In recent years, the demand for biomass raw materials has been growing worldwide due to calls for the creation of a recycling-based society (sustainability) that should develop sustainably while taking into consideration the global environment, ecosystems, socio-economy, etc. In particular, major domestic distributors and food manufacturers are actively promoting environmentally-friendly packaging in response to COP21 and as an effort toward the goal of "ensuring sustainable production and consumption patterns," one of the Sustainable Development Goals (SDGs). Traditional efforts in environmentally-friendly packaging have promoted the "3Rs" (reduction, reuse, and recycling), but in recent years, from the perspective of conserving petroleum resources, there has been an increase in the use of resins made primarily from plant-derived ingredients (hereinafter referred to as "plant-derived resins" or "biomass resins") instead of resins made primarily from petroleum-derived ingredients.

Biomass is a reusable organic resource derived from plants and living organisms, excluding fossil resources. Biomass resin made from plant-derived raw materials is produced by plants using atmospheric carbon dioxide and water as raw materials through a photosynthetic reaction, and even if such resin is incinerated and carbon dioxide is generated, the balance of carbon dioxide in the atmosphere is plus or minus zero, which is the so-called "carbon neutral" concept. Based on this concept, active consideration is being given in various fields to using resins made from plant-derived biomass raw materials, which are carbon neutral, in various materials instead of resins derived from fossil resources.

Biodegradable resins derived from plants, such as polylactic acid (PLA), are representative of biomass resins, but these resins have had problems in terms of cost and processability when it comes to general-purpose use. On the other hand, there is growing global demand for plant-derived polyethylene, a renewable resource derived from sugar cane, as a general-purpose resin, and as production volume increases, it has become more cost-effective and general-purpose. In terms of packaging that reduces the environmental impact, such general-purpose plant-derived resins are often used for sanitary and food packaging containers, miscellaneous goods, and plastic bags, but more recently they are being used more widely in food packaging films.

As a resin film using a plant-derived resin, for example, a multilayer film that contains a propylene-based resin as the main component and a plant-derived resin in some layers has been disclosed (Patent Document 1). However, in the laminate in which the first base layer and the print layer are laminated, each layer is mainly formed from a petroleum-derived material, so the biomass content of the laminate is low, and improvement has been required.

Furthermore, although plant-derived biomass resins are highly environmentally friendly, they often exhibit different properties from petroleum-derived resins, and there are cases where they simply cannot be substituted. For example, when a film is produced by replacing petroleum-derived resins with plant-derived resins, various physical properties of the film, such as impact resistance, rigidity, film-forming properties, glossiness, and haze, may be impaired. In particular, increasing the proportion of plant-derived resin has a large effect on the physical properties of the film. Therefore, in a laminate in which a first base material layer and a printing layer are laminated, it is necessary to increase the biomass content of the entire laminate while maintaining the functionality of the laminate.

In particular, when printing with surface printing inks that print designs only on the outside of packaging materials, strong adhesion between the ink and the substrate is required. The use of plant-derived raw materials in inks is becoming more common as an environmentally friendly approach, and studies are underway to improve the adhesion of ink while using plant-derived raw materials. It is expected that a film with good adhesion to ink will promote efforts to use plant-derived raw materials in inks or to increase the amount of plant-derived raw materials used in inks.

JP 2021-175607 A

The object of the present invention is to provide a multilayer film that has excellent film-forming properties even when the biomass content is increased by using a plant-derived resin, a laminate that has excellent adhesion between the printed layer, and a packaging material made of this multilayer film or laminate.

In an embodiment of the present invention,
A laminate in which at least a first base material layer and a printing layer are laminated,
(1) The first base layer is
The coating composition has a surface layer (A), an intermediate layer (B), and a sealing layer (C),
The surface layer (A) contains a propylene-based resin,
The intermediate layer (B) contains biomass polyethylene,
The sealing layer (C) is a multilayer film containing a propylene-ethylene copolymer,
(2) There is provided a laminate, wherein the printed layer is a layer formed by printing with a liquid printing ink.

In another aspect of the present invention, the laminate is provided in which the printed layer is a layer formed by printing with a liquid printing ink containing a plant-derived raw material. The laminate is also provided in which the printed layer is on the surface layer (A) side of the first base layer.

In another aspect of the present invention, a packaging material comprising the laminate is provided. The packaging material is preferably a packaging material for food.

The laminate of the present invention uses a multilayer film containing biomass resin, which can contribute to reducing the environmental impact. In addition, since the printed layer and the base layer of the multilayer film have good adhesion, it is possible to provide a laminate with excellent appearance and a packaging material including the laminate.

(Definition of words)
In the present invention, "biomass" refers to "renewable organic resources derived from plants or living organisms, excluding fossil resources." Furthermore, biomass resin refers to resin derived from plants.
In the present invention, the term "plant-derived" means that plants or the like are used as raw materials, and the term "petroleum-derived" means that fossil fuels such as petroleum are used as raw materials.
In the present invention, the term "liquid printing ink" refers to a liquid ink applied to a printing method using a printing plate, such as gravure printing ink or flexographic printing ink, and is preferably gravure printing ink or flexographic printing ink. The liquid printing ink of the present invention does not contain an active energy curable component, i.e., it is an active energy ray non-reactive liquid printing ink.
In the present invention, all "ink" refers to "printing ink." All "parts" refer to "parts by mass."

<Biomass ratio>
In the present invention, the "biomass ratio" refers to the ratio of plant-derived components contained in a product to the total amount of the product.
<Laminate>
The laminate of the present invention is a laminate including at least a multilayer film as a first base layer and a printed layer, and (1) the first base layer is
The coating composition has a surface layer (A), an intermediate layer (B), and a sealing layer (C),
The surface layer (A) contains a propylene-based resin,
The intermediate layer (B) contains biomass polyethylene,
The sealing layer (C) is a multilayer film containing a propylene-ethylene copolymer,
(2) The printed layer is a layer formed by printing with liquid printing ink.

More specifically, the laminate of the present invention has the following structure:
(1) Multilayer film/printed layer (2) Multilayer film/printed layer/overcoat layer, but not limited thereto.
The laminate of the present invention may further include one or more other layers, such as, but not limited to, a substrate layer, an adhesive layer, a barrier layer, a second printed layer, and the like.
The substrate layer may be a sealant film, an unstretched film, a stretched film, a metal-vapor-deposited unstretched film, a metal-vapor-deposited stretched film, or a transparent vapor-deposited film. When there are a plurality of substrate layers, the substrate layers may have the same composition or different compositions. In addition, there may be a plurality of adhesive layers, and the adhesive layers may have the same composition or different compositions.

In the present invention, the biomass degree of the laminate is preferably 2% or more, more preferably 3% to 60%, and even more preferably 5% to 60%. If the biomass degree is within the above range, the amount of petroleum-derived plastics used can be reduced, and the environmental burden can be reduced.

The thickness of the laminate of the present invention is preferably 10 μm or more and 500 μm or less, more preferably 20 μm or more and 300 μm or less, and even more preferably 25 μm or more and 200 μm or less.

The laminate of the present invention may include, in addition to the first base layer and the printed layer, other layers such as an overcoat layer, a barrier layer, an adhesive layer, other base layers, a second printed layer, and a third printed layer. When the laminate has two or more other layers, they may have the same composition or different compositions.
Each layer constituting the laminate will now be described.

<First Base Layer>
The first base layer of the present invention is a multilayer film having a surface layer (A), an intermediate layer (B), and a seal layer (C).

(Surface layer (A) of multilayer film)
The surface layer (A) in the multilayer film which is the first base layer of the present invention contains a propylene-based resin. The surface layer (A) is a layer onto which a liquid printing ink is printed, and has excellent adhesion to the ink and excellent design properties.

As the propylene-based resin, for example, a propylene homopolymer, a propylene-α-olefin random copolymer, a propylene-α-olefin block copolymer, etc. can be used.
Among these, propylene homopolymers can be preferably used in applications requiring transparency, since high rigidity can be easily obtained.

When the multilayer film of the present invention is a transparent film, the resin constituting the surface layer (A) in the multilayer film preferably contains 80% by mass or more of the above-mentioned propylene homopolymer, more preferably 90% by mass or more, and it is also preferable that the resin is substantially composed of only propylene homopolymer.

The propylene homopolymer used in the present invention preferably has an MFR (temperature 230° C., load 2.16 kg) of 0.5 g/10 min to 30 g/10 min. From the viewpoint of reducing the shrinkage of the film during bag making and improving the film formability, the MFR is preferably 4 g/10 min to 20 g/10 min, and more preferably 5 g/10 min to 15 g/10 min.
The propylene homopolymer preferably has a melting point of 120 to 172° C., and more preferably 125 to 170° C. If the MFR and melting point are within these ranges, the shrinkage of the film during bag making can be reduced, and the film formability of the film can be improved.

If you want to make a matte multilayer film, adding a propylene-based block copolymer will give you a matte laminated film with high rigidity, excellent design, and good impact and abrasion resistance.

As the propylene-based block copolymer, a copolymer of propylene and another α-olefin can be used. Examples of α-olefins include ethylene, 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene, among which ethylene is preferred because it has an excellent balance of matte feel, cold resistance, and rigidity.

The melt flow rate (MFR) of the propylene-based block copolymer is preferably 0.5 g/10 min or more, more preferably 1 g/10 min or more, because it is easy to mold and to easily obtain suitable impact resistance and matte feel, and is preferably 20 g/10 min or less, more preferably 10 g/10 min or less.
The melting point of the propylene-based block copolymer is preferably 155° C. or higher and 170° C. or lower, since this facilitates obtaining favorable bag formability.

The content of the propylene-based block copolymer in the surface layer (A) is determined by the balance between the matte finish, melt-cutting strength, and bag-making suitability, but it is preferable for the content to be 70% by mass or more of the resin components used in the surface layer (A). By setting the content within this range, it becomes easier to obtain a uniform matte finish with excellent design. In particular, when improving impact resistance and matte finish, it is preferable to set the content to 80 to 100% by mass.

The propylene-based block copolymer used in the surface layer (A) may be a single copolymer or a plurality of copolymers. When a plurality of propylene-based block copolymers are used, it is preferable that the total content of the propylene-based block copolymers used is within the above range.
Examples of propylene-based block copolymer resins used in the surface layer (A) and having an excellent balance between matte feel, melt-cutting strength, and bag-making suitability include BC8 and BC7 (manufactured by Japan Polypropylene Corporation), E150GK and F704V (manufactured by Prime Polymer Co., Ltd.), PC480A, PC684S, PC380A, and VB370A (manufactured by Sunallomer Co., Ltd.).

In addition, when a resin other than a propylene-based block copolymer is used in the surface layer (A), various polyolefin-based resins used in packaging films can be used, such as propylene homopolymers, propylene-α-olefin random copolymers (propylene-ethylene copolymers, propylene-butene-1 copolymers, propylene-ethylene-butene-1 copolymers, metallocene catalyst-based polypropylenes, etc.), high density polyethylene (HDPE), very low density polyethylene (VLDPE), linear low density polyethylene (LLDPE), low density polyethylene (LDPE), and other polyolefins. Examples of the polymerizable compound that can be used include polyethylene-based resins, ethylene-based copolymers such as ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate (EMA) copolymer, ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH), ethylene-acrylic acid copolymer (EAA), and ethylene-methacrylic acid copolymer (EMAA); and further, ionomers of ethylene-acrylic acid copolymers, ionomers of ethylene-methacrylic acid copolymers, and the like.
Among them, in order to improve the matte feel, it is preferable to use an ethylene-based resin in combination, and it is more preferable to use high-density polyethylene.

The surface layer (A) used in the present invention may contain components other than the above propylene-based resin, as long as the effects of the present invention are not impaired. Examples of such components include ethylene-based resins, polystyrene-based resins, polyurethane-based resins, polyester-based resins, polyamide-based resins, etc. Also, plant-derived ethylene-based resins may be used in combination with petroleum-derived ethylene-based resins.

(Intermediate layer (B) of multilayer film)
The multilayer film used in the present invention contains an intermediate layer (B). The intermediate layer (B) contains biomass polyethylene.

The biomass polyethylene used in the intermediate layer (B) is a polyethylene-based resin produced from plant-derived ethylene using sugarcane, corn, beet, etc. as starting materials. Examples of the biomass polyethylene include linear low density polyethylene (LLDPE), linear medium density polyethylene (LMDPE), linear high density polyethylene (LHDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), etc., which may be used alone or in a mixture of two or more types. Among these, linear low density polyethylene is particularly preferred. The density of the linear low density polyethylene is preferably 0.925 g/cm ³ or less, and more preferably 0.920 g/cm ³ or less. By setting the density of the linear low density polyethylene used within the above range, it becomes easier to have both suitable melt-cutting strength, high impact resistance, and bag-breaking resistance.

The MFR of the biomass polyethylene used in the intermediate layer (B) is preferably 0.1 to 30 g/10 min, and particularly preferably 0.5 to 20 g/10 min. By making it 1 g/10 min or more, it becomes easier to obtain favorable film-forming properties, and by making it 20 g/10 min or less, it becomes easier to obtain favorable moldability.

The biomass polyethylene used in the intermediate layer (B) is different from the petroleum-based manufacturing method in that the raw material is a plant such as sugar cane, and the monomer production is different, but the manufacturing method is otherwise the same. There is no particular limitation on the manufacturing method, and it can be manufactured by a known method. For example, a manufacturing method using a Ziegler-Natta catalyst or a metallocene catalyst can be mentioned.
Specifically, a method of polymerization in which propylene alone or a desired α-olefin such as ethylene is added in a catalyst system using a titanium-containing compound itself or a titanium-containing compound supported on a carrier such as a magnesium compound as a main catalyst and an organoaluminum compound as a cocatalyst can be mentioned. This polymerization may be any process such as a slurry polymerization method, a solution polymerization method, or a gas phase polymerization method.
Also, homogeneous catalysts may be used, and examples of such homogeneous catalysts include catalysts consisting of vanadium compounds and organoaluminum compounds that have been used conventionally, transition metal compounds such as zirconium, titanium, hafnium, etc., having one or two cyclopentadienyl groups, substituted cyclopentadienyl groups, indenyl groups, substituted indenyl groups, etc., as ligands, and metallocene catalysts consisting of transition metal compounds in which the ligands are geometrically controlled and cocatalysts such as aluminoxanes, ionic compounds, etc. The metallocene catalyst may be used in any process, such as homogeneous polymerization in the presence of a solvent, slurry polymerization, gas phase polymerization, etc., using an organoaluminum compound as necessary.

Commercially available examples of such biomass polyethylene include Braskem's SLL118, SLL118/21, SLL218, SLL318, SLH118, SLH218, SLH0820/30AF, SBC818, SPB208, STN7006, and SEB853.

Furthermore, the intermediate layer (B) preferably contains a polyolefin resin.
As the polyolefin resin, various polyolefin resins used in packaging films can be used, for example, propylene homopolymers, propylene-ethylene random copolymers, propylene-ethylene block copolymers, propylene-α-olefin copolymers (propylene-1-butene random copolymers, propylene-1-hexene random copolymers, etc.), propylene-ethylene-1-butene random copolymers, metallocene catalyst-based polypropylene and other propylene-based resins (b1-2), very low density polyethylene (VLDPE), linear low density polyethylene (LLDPE), low density polyethylene (LDP), etc. Examples of the resin that can be used include polyethylene resins such as ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate (EMA) copolymer, ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH), ethylene-acrylic acid copolymer (EAA), and ethylene-methacrylic acid copolymer (EMAA), as well as ionomers of ethylene-acrylic acid copolymers and ionomers of ethylene-methacrylic acid copolymers.

Among the above polyolefin resins, it is preferable to use linear low-density polyethylene for the intermediate layer (B) from the viewpoint of providing suitable impact resistance.
The linear low-density polyethylene preferably has a density of 0.925 g/ ^cm3 or less, and more preferably 0.920 g/ ^cm3 or less. By setting the density of the linear low-density polyethylene used within the above range, it becomes easier to have suitable melt-cutting strength, high impact resistance, and bag-breaking resistance.

The content of the polyolefin resin in the intermediate layer (B) used in the present invention is preferably 80% by mass or more, more preferably 85% by mass or more, and even more preferably 90% by mass or more, in the total amount of the resin constituting the intermediate layer (B). By setting the content within this range, a film having suitable mechanical strength can be easily obtained.
In addition, when the intermediate layer (B) contains a petroleum-derived linear low density polyethylene, the content is preferably 3% by mass or more, more preferably 4% by mass or more, in the resin constituting the intermediate layer (B). When the linear low density polyethylene content is within this range, the impact resistance is good. In addition, when the biomass polyethylene is a linear low density polyethylene, the total content of the petroleum-derived linear low density polyethylene and the biomass linear low density polyethylene is preferably 7% by mass or more, more preferably 10% by mass or more, in the resin constituting the intermediate layer (B).

The intermediate layer (B) used in the present invention may contain a coloring pigment. As the coloring pigment used in the intermediate layer (B), various coloring pigments that can be kneaded with the above-mentioned resins can be appropriately used. If it is desired to make the resulting multilayer film white, a white pigment may be used, and among them, titanium oxide is preferably used because it is low cost, has excellent handling properties, and is easy to impart a suitable degree of whiteness.

When the intermediate layer (B) contains a color pigment, the content of the color pigment in the intermediate layer (B) is preferably 1.2×10 ⁻⁴ to 10×10 ⁻⁴ g/cm ² per unit area of the intermediate layer (B). By setting the content to this range, suitable whiteness can be imparted.

(Sealing layer (C))
The multilayer film used in the present invention further has a seal layer (C). The seal layer (C) is designed so that a sufficient seal strength can be easily obtained when the seal layers (C) of the multilayer film of the present invention are heat sealed to each other or to a container made of other material, and contains a propylene-ethylene copolymer such as a propylene-ethylene random copolymer, since a suitable seal strength can be obtained particularly when the seal layers (C) are heat sealed to each other when the multilayer film is used as a packaging bag. Furthermore, an ethylene-α-olefin copolymer can be used in combination to adjust the seal strength.

The ethylene content in the propylene-ethylene random copolymer is preferably 0.3 to 10% by mass, and more preferably 0.5 to 6% by mass. By setting the ethylene content within this range, it becomes easier to obtain suitable rigidity and blocking resistance, and it becomes easier to realize suitable bag making and packaging suitability. The ethylene content is measured by infrared absorption spectroscopy.

The MFR of the propylene-ethylene random copolymer is preferably 1 to 20 g/10 min, particularly preferably 3 to 7 g/10 min. By making it 1 g/10 min or more, suitable film-forming properties are easily obtained, and by making it 20 g/10 min or less, suitable moldability is easily obtained.
The method for producing the propylene-ethylene random copolymer used in the present invention is not particularly limited, and the copolymer may be produced by a known method, such as a method using a Ziegler-Natta catalyst or a metallocene catalyst.
Specifically, a method of polymerization can be mentioned in which a titanium-containing compound itself or a titanium-containing compound supported on a carrier such as a magnesium compound is used as a main catalyst and an organoaluminum compound is used as a co-catalyst in a catalyst system in which propylene and ethylene are added to perform polymerization. This polymerization may be any process such as a slurry polymerization method, a solution polymerization method, or a gas phase polymerization method.

Homogeneous catalysts may also be used, including homogeneous catalyst systems such as catalysts consisting of vanadium compounds and organoaluminum compounds that have been used in the past, transition metal compounds such as zirconium, titanium, hafnium, etc., having one or two cyclopentadienyl groups, substituted cyclopentadienyl groups, indenyl groups, substituted indenyl groups, etc. as ligands, and metallocene catalysts consisting of transition metal compounds in which the ligands are geometrically controlled and cocatalysts such as aluminoxanes or ionic compounds. The metallocene catalyst may be used in any process, such as homogeneous polymerization in the presence of a solvent, slurry polymerization, or gas phase polymerization, using an organoaluminum compound as necessary.

The sealing layer (C) included in the multilayer film of the present invention may further contain other polyolefin-based resins in addition to the above-mentioned propylene-ethylene random copolymer. Examples of such other polyolefin-based resins include the polyolefin-based resins exemplified for the surface layer (A) and the intermediate layer (B), and among these, high-density polyethylene and propylene-α-olefin copolymers (propylene-1-butene random copolymer, propylene-1-hexene random copolymer, etc.) are preferably used.

In order to adjust the balance of physical properties of the multilayer film used in the present invention, it is also preferable to provide a support layer (D) between the intermediate layer (B) and the sealing layer (C). Resins that can be used in the support layer (D) include the same polyolefin resins exemplified in the intermediate layer (B) described above, and these resins can be used alone or in combination. Among these, propylene resins, linear low density polyethylene (LLDPE), low density polyethylene (LDPE), etc. can be preferably used. It is also preferable to use a plant-derived polyolefin resin in the support layer (D) because it can improve the biomass content of the laminate.

The multilayer film used in the present invention may have one or more other layers in addition to the surface layer (A), intermediate layer (B), seal layer (C), and support layer (D). The other layers may be made of various resin materials used in packaging films, and are preferably provided between the intermediate layer (B) and the seal layer (C).

If necessary, components such as anti-fog agents, antistatic agents, heat stabilizers, nucleating agents, antioxidants, lubricants, anti-blocking agents, release agents, UV absorbers, and colorants can be added to each of the above layers, provided that the purpose of the present invention is not impaired.

(Multilayer film)
The total mass of the polyethylene resin contained in the multilayer film used in the present invention is preferably 4 mass% or more, more preferably 5 mass% or more, based on the mass of the multilayer film. The polyethylene resin includes both petroleum-derived resins and plant-derived resins.
In order to increase the amount of plant-derived components in the multilayer film and thereby increase the biomass content, the total mass of plant-derived polyethylene is preferably 2 mass% or more, and more preferably 3 mass% or more, relative to the mass of the multilayer film.

The total mass of the propylene-based resin contained in the multilayer film used in the present invention is preferably 40% by mass or more, more preferably 45% by mass or more, and even more preferably 48% by mass or more, based on the mass of the multilayer film.

The multilayer film used in the present invention preferably has a total thickness in the range of 20 to 50 μm so that it has sufficient strength as a film even when used alone, and preferably has a thickness of 25 to 40 μm, particularly when used for packaging relatively light contents such as bread.

The thickness of the surface layer (A) of the multilayer film used in the present invention is preferably 10 to 40% of the total thickness. The thickness of the surface layer (A) is preferably 2 to 20 μm, more preferably 4 to 16 μm, because this makes it easier to obtain a suitable design.
The thickness of the intermediate layer (B) is preferably 30 to 90% of the total thickness, and is preferably 6 to 45 μm, more preferably 10 to 30 μm.
Furthermore, it is preferable that the thickness of the seal layer (C) is 10 to 25% of the total thickness. The thickness of the seal layer (C) is preferably 2 to 12.5 μm, and more preferably 3 to 10 μm.
When the support layer (D) is provided, the total thickness of the intermediate layer (B) and the support layer (D) is preferably 6 to 45 μm, and more preferably 30 to 90% of the total thickness.

The rigidity of the multilayer film used in the present invention is preferably 450 MPa or more, more preferably 500 MPa or more, and even more preferably 550 MPa or more, in order to maintain a suitable strength when used as a packaging material.
Furthermore, the impact strength of the multilayer film is preferably 0.15 J (23° C.) or more, and more preferably 0.17 J (23° C.) or more. The impact strength is determined by holding a sample of the multilayer film for 6 hours in a thermostatic chamber conditioned at 23° C., and then measuring the impact strength by a film impact method using a spherical impact head having a diameter of 25.4 mm.

(Method of manufacturing multilayer film)
The method for producing the multilayer film used in the present invention is not particularly limited, but examples thereof include a coextrusion method in which each resin or resin mixture used for the surface layer (A), intermediate layer (B) and seal layer (C) is heated and melted in a separate extruder, and laminated in the molten state in the order of (A)/(B)/(C) by a method such as a coextrusion multilayer die method or a feed block method, or formed into a film by inflation or a T-die chill roll method. When the multilayer film includes a support layer (D), the layers may be laminated in the order of (A)/(B)/(D)/(C). This coextrusion method is preferable because it allows relatively free adjustment of the thickness ratio of each layer, and a coextruded multilayer film with excellent hygienic properties and cost performance can be obtained. Furthermore, when resins with a large difference in melting point are used in combination, the appearance of the film may deteriorate during coextrusion processing. In order to suppress such deterioration, the T-die chill roll method, which allows melt extrusion at a relatively high temperature, is preferable.

The multilayer film used in the present invention is obtained as a substantially unstretched multilayer film by the above manufacturing method, so secondary forming such as deep drawing by vacuum forming is also possible.

Furthermore, in order to improve the adhesion between the surface layer (A) of the multilayer film used in the present invention and the printing ink, it is preferable to subject the surface layer (A) to a surface treatment. When laminating another film to the surface of the seal layer (C), it is preferable to subject the seal layer (C) to a surface treatment in order to improve adhesion to the adhesive. Examples of such surface treatments include surface oxidation treatments such as corona treatment, plasma treatment, chromic acid treatment, flame treatment, hot air treatment, and ozone/ultraviolet light treatment, as well as surface unevenness treatments such as sandblasting, with corona treatment being preferred.

By overlapping the seal layers (C) of the multilayer film used in the present invention and heat sealing them, or overlapping the surface layer (A) and the seal layer (C) and heat sealing them, a packaging bag can be produced in which the seal layer (C) is formed on the inside. For example, two sheets of the multilayer film are cut to the desired size of the packaging bag, overlapped and heat sealed on three sides to form a bag, and then the contents are filled from the one side that is not heat sealed and heat sealed to seal it, so that it can be used as a packaging bag. Furthermore, it is also possible to seal the ends of a roll-shaped film into a cylindrical shape using an automatic packaging machine, and then seal the top and bottom to form a packaging bag. The sealing method is not particularly limited, and may be heat sealing or ultrasonic sealing, but heat sealing is preferred.

The multilayer film used in the present invention can also be laminated with another film to be used as a composite film. The other film may be provided on either the surface layer (A) side or the seal layer (C) side, but it is preferable to provide a sealant film on the seal layer (C) side.

<Printed layer>
The printing layer used in the present invention is a layer on which a desired pattern is formed using liquid printing ink in order to impart cosmetic properties, various information related to the contents, and functionality to the printed material. The printing layer is formed by printing a gravure printing ink or flexographic printing ink (hereinafter referred to as liquid printing ink) containing a binder resin and a colorant.

The printing layer used in the present invention may be a single layer, or may have multiple printing layers. When there are multiple printing layers, the liquid printing ink used for each printing layer may be the same, may have the same composition but with different colorants, or may have different compositions.

(Liquid printing ink)
The liquid printing inks used in the present invention are used as gravure printing inks or flexographic printing inks, and are roughly divided into organic solvent-based liquid printing inks that use organic solvents as the main solvent, and water-based liquid printing inks that use water as the main solvent. Here, the general-purpose organic solvent-based liquid printing inks will be mainly described.

(Organic solvent-based liquid printing ink)
Organic solvent-based liquid printing ink is produced by dispersing a mixture of binder resin, organic solvent medium, dispersant, defoamer, etc., in a disperser to obtain a pigment dispersion. The resulting pigment dispersion is then mixed with a resin and, if necessary, additives such as a leveling agent, and then stirred. The disperser used for production is a bead mill, Eiger mill, sand mill, gamma mill, attritor, etc., which are commonly used in the production of gravure and flexographic printing inks.

The ink viscosity of the organic solvent-based liquid printing ink during gravure printing should be in the range of 12 to 30 seconds at 25°C using a Zahn Cup #3 manufactured by Rigo Co., Ltd., and is preferably 14 to 20 seconds.

The viscosity of the ink can be adjusted by appropriately selecting the type and amount of raw materials used, binder resin, pigment, organic solvent, etc. The viscosity of the ink can also be adjusted by adjusting the particle size and particle size distribution of the pigment in the ink.

(Creation of printed matter)
The organic solvent-based liquid printing ink has excellent adhesion to various substrates and can be used for printing on paper, synthetic paper, thermoplastic resin films, plastic products, steel plates, etc., and is useful as an ink for gravure printing using a gravure printing plate made by electronic engraving or the like, or for flexographic printing using a flexographic printing plate made by a resin plate or the like.

The film thickness of the liquid printing ink formed by the gravure printing method or the flexographic printing method using the organic solvent-based liquid printing ink is, for example, 5 μm or less, preferably 3 μm or less, and more preferably 1 μm or less.

(Binder Resin (A))
Examples of the binder resin (A) used in the liquid printing ink used in the present invention include cellulose-based resins such as nitrocellulose, cellulose acetate propionate (CAP) and cellulose acetate butyronate (CAB), and other cellulose-based resins, polyamide-based resins, urethane-based resins, acrylic-based resins, vinyl chloride-vinyl acetate copolymer resins, chlorinated polypropylene resins, ethylene-vinyl acetate copolymer resins, vinyl acetate resins, polyvinyl chloride resins, and other vinyl chloride resins, polyester resins, alkyd resins, rosin-based resins, rosin-modified maleic acid resins, ketone resins, cyclized rubbers, chlorinated rubbers, butyral resins, and petroleum resins.

(Cellulosic resin)
Examples of cellulose resins include cellulose acetate propionate, cellulose acetate butyrate and other cellulose ester resins, nitrocellulose (also called soluble cellulose), hydroxyalkyl cellulose, and carboxyalkyl cellulose. The cellulose ester resin preferably has an alkyl group, and examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a pentyl group, and a hexyl group, and the alkyl group may further have a substituent.
Of the above, the cellulose-based resin is preferably cellulose acetate propionate, cellulose acetate butyrate, or nitrocellulose. Nitrocellulose is particularly preferred. The molecular weight is preferably 5,000 to 200,000, more preferably 10,000 to 50,000, in terms of weight average molecular weight. In addition, the glass transition temperature is preferably 120°C to 180°C.
Nitrocellulose (soluble cellulose) is preferably obtained by reacting natural cellulose with nitric acid to replace three hydroxyl groups in the six-membered ring of the anhydrous glucopyranose group in the natural cellulose with nitric acid to produce a nitric acid ester.

The amount of nitrocellulose (soluble nitrocellulose) added is preferably 0.15 to 40% by mass, and more preferably 1.0 to 35% by mass, based on the total amount of liquid printing ink.

(Polyamide resin)
The polyamide resin is, for example, a thermoplastic polyamide soluble in an organic solvent that can be obtained by polycondensation of a polybasic acid and a polyamine. In particular, a polyamide resin containing a reaction product of an acid component containing a polymerized fatty acid and/or a dimer acid with an aliphatic and/or aromatic polyamine is preferable, and further, a polyamide resin containing a portion of primary and secondary monoamines is preferable.
Examples of polybasic acids used as raw materials for the polyamide resin include, but are not limited to, adipic acid, sebacic acid, azelaic acid, phthalic anhydride, isophthalic acid, suberic acid, glutaric acid, fumaric acid, pimelic acid, oxalic acid, malonic acid, succinic acid, maleic acid, terephthalic acid, 1,4-cyclohexyldicarboxylic acid, trimellitic acid, dimer acid, hydrogenated dimer acid, polymerized fatty acid, and the like. Among these, polyamide resins containing a structure derived from dimer acid or polymerized fatty acid as the main component (50% by mass or more in the polyamide resin) are preferred. Here, polymerized fatty acid is obtained by cyclization reaction of unsaturated fatty acid, and includes monobasic fatty acid, dimerized polymerized fatty acid (dimer acid), trimerized polymerized fatty acid, and the like. In addition, fatty acids constituting dimer acid or polymerized fatty acid can be preferably those derived from natural oils such as soybean oil, palm oil, and rice bran oil, and those obtained from oleic acid and linoleic acid are preferred.
The polybasic acid may be used in combination with a monocarboxylic acid, such as acetic acid, propionic acid, lauric acid, palmitic acid, benzoic acid, or cyclohexane carboxylic acid.

Examples of the polyamine include polyamines, primary and secondary monoamines, etc. Examples of the polyamines used in the polyamide resin include aliphatic diamines such as ethylenediamine, propylenediamine, hexamethylenediamine, and methylaminopropylamine, and aliphatic polyamines such as diethylenetriamine and triethylenetetramine, and examples of the alicyclic polyamines include cyclohexylenediamine and isophoronediamine. Examples of the aromatic aliphatic polyamines include xylylenediamine, and examples of the aromatic polyamines include phenylenediamine and diaminodiphenylmethane. Examples of the primary and secondary monoamines include n-butylamine, octylamine, diethylamine, monoethanolamine, monopropanolamine, diethanolamine, and dipropanolamine.
The amount of the polyamide resin added is preferably 0.15 to 40% by mass, and more preferably 1.0 to 35% by mass, based on the total amount of the liquid printing ink.

(urethane resin)
The urethane resin is not particularly limited as long as it is a polyurethane resin obtained by reacting a polyol with a polyisocyanate. As the polyol, for example, various known polyols generally used in the production of polyurethane resins can be used, and one or more kinds may be used in combination. For example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-ethyl-2-butyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1,5 pentanediol, hexanediol, octanediol, 1,4-butynediol, 1,4-butylenediol, diethylene glycol, triethylene glycol, dipropylene glycol, etc. Saturated or unsaturated low molecular weight polyols (1), such as ethylene glycol, glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, 1,2,4-butanetriol, sorbitol, and pentaerythritol; combinations of these low molecular weight polyols (1) with sebacic acid, adipic acid, phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, trimellitic acid, and pimelic acid; polyester polyols (2) obtained by dehydration condensation or polymerization of polyvalent carboxylic acids such as romellitic acid and dimer acid or their anhydrides; polyester polyols (3) obtained by ring-opening polymerization of cyclic ester compounds, such as lactones such as polycaprolactone, polyvalerolactone, and poly(β-methyl-γ-valerolactone); polycarbonate polyols (4) obtained by reacting the low molecular weight polyols (1) or the like with, for example, dimethyl carbonate, diphenyl carbonate, ethylene carbonate, phosgene, or the like; polybutadiene glycols (5); glycols (6) obtained by adding ethylene oxide or propylene oxide to bisphenol A; and acrylic polyols (7) obtained by copolymerizing, in one molecule, one or more hydroxyethyl groups, hydroxypropyl acrylate, hydroxybutyl acrylate, or the like, or the corresponding methacrylic acid derivatives, with, for example, acrylic acid, methacrylic acid, or an ester thereof.

Examples of polyisocyanates include various known aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates that are commonly used in the production of polyurethane resins. For example, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 1-methyl-2,4-phenylene diisocyanate, 1-methyl-2,6-phenylene diisocyanate, 1-methyl-2,5-phenylene diisocyanate, 1-methyl-2,6-phenylene diisocyanate, 1-methyl-3,5-phenylene diisocyanate, 1-ethyl-2,4-phenylene diisocyanate, 1-isopropyl-2,4-phenylene diisocyanate, 1,3-dimethyl-2,4-phenylene diisocyanate, and 1,3-dimethyl-4,6-phenylene diisocyanate. cyanate, 1,4-dimethyl-2,5-phenylene diisocyanate, diethylbenzene diisocyanate, diisopropylbenzene diisocyanate, 1-methyl-3,5-diethylbenzene diisocyanate, 3-methyl-1,5-diethylbenzene-2,4-diisocyanate, 1,3,5-triethylbenzene-2,4-diisocyanate, naphthalene-1,4-diisocyanate, naphthalene-1,5-diisocyanate, 1-methyl-naphthalene-1,5-diisocyanate, naphthalene-2,6-diisocyanate, naphthalene-2,7-diisocyanate, 1 Aromatic polyisocyanates such as 1-dinaphthyl-2,2'-diisocyanate, biphenyl-2,4'-diisocyanate, biphenyl-4,4'-diisocyanate, 3-3'-dimethylbiphenyl-4,4'-diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, and diphenylmethane-2,4-diisocyanate; tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, trimethylhexamethylene diisocyanate, and 1,3-cyclopentylene diisocyanate. Aliphatic or alicyclic polyisocyanates such as 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, 1,3-di(isocyanatemethyl)cyclohexane, 1,4-di(isocyanatemethyl)cyclohexane, lysine diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,4'-dicyclohexylmethane diisocyanate, 2,2'-dicyclohexylmethane diisocyanate, and 3,3'-dimethyl-4,4'-dicyclohexylmethane diisocyanate can be used. These polyisocyanates may be used alone or in combination of two or more. Among these, these diisocyanate compounds can be used alone or in a mixture of two or more.

Chain extenders can also be used. Examples of chain extenders include ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4'-diamine, and the like. In addition, amines having a hydroxyl group in the molecule, such as 2-hydroxyethylethylenediamine, 2-hydroxyethylpropyldiamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine, and di-2-hydroxypropylethylenediamine, can also be used. These chain extenders can be used alone or in combination of two or more.

Furthermore, a monovalent active hydrogen compound can be used as a terminal blocking agent for the purpose of stopping the reaction. Examples of such compounds include dialkylamines such as di-n-butylamine, and alcohols such as ethanol and isopropyl alcohol. Furthermore, when it is particularly desired to introduce a carboxyl group into the polyurethane resin, amino acids such as glycine and L-alanine can be used as a reaction stopping agent. These terminal blocking agents can be used alone or in combination of two or more.
The weight average molecular weight of the urethane resin is preferably in the range of 10,000 to 100,000, and more preferably in the range of 15,000 to 80,000.

A particularly preferred example of the urethane resin is urethane resin (A) obtained by reacting a polyester polyol, which is made from a polycarboxylic acid having 7 or more carbon atoms and 2 or more carboxyl groups and a compound having 2 or more hydroxyl groups as reaction raw materials, with a polyisocyanate.

Examples of polycarboxylic acids having 7 or more carbon atoms and 2 or more carboxyl groups include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, and the anhydrides of these acids; aliphatic dicarboxylic acids such as pimelic acid, suberic acid, azelaic acid, sebacic acid, and dimer acid; tricarboxylic acids such as trimellitic acid and its anhydrides; benzenetetracarboxylic acid, benzenepentacarboxylic acid, benzenehexacarboxylic acid, and the anhydrides of these acids. These polybasic acids may be used alone or in combination of two or more. Among them, sebacic acid and dimer acid are preferred because they provide adhesion to a wide variety of film substrates, and these may be used alone or in combination.

The polyester polyol may contain other polyvalent carboxylic acids as required. Any of the various known polyvalent carboxylic acids commonly used in the production of polyester polyols may be used, and one or more of them may be used in combination. Examples include adipic acid, maleic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, and glutaric acid.

In addition, as global awareness of environmental issues has increased in recent years, attention has been focused on raw materials derived from biomass resources such as plants, rather than petroleum-derived raw materials that have an impact on global warming, and it is possible to use these raw materials. Examples of polycarboxylic acids derived from biomass resources include sebacic acid, dimer acid, succinic acid, succinic anhydride, and adipic acid.

Examples of compounds having two or more hydroxyl groups include glycols such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, 1,4-cyclohexanediol, and 1,4-cyclohexanedimethanol; 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,2-butanediol, 1,3-butanediol, 2-butyl-2 -Ethyl-1,3-propanediol, 1,2-propanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 2-isopropyl-1,4-butanediol, 2,4-dimethyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-ethyl-1,6-hexanediol, 3,5-heptanediol, 2-methyl-1,8-octanediol and other branched glycols; glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, sorbitol, and the like can be used. These compounds may be used alone or in combination of two or more.

As with polycarboxylic acids, compounds with two or more hydroxyl groups can also be derived from biomass resources such as plants. Examples of compounds with two or more hydroxyl groups derived from biomass resources include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, diethylene glycol, and glycerin.

The number average molecular weight of the polyester polyol is preferably in the range of 500 to 8,000, more preferably in the range of 800 to 7,000, and even more preferably in the range of 900 to 6,000.

Moreover, it is more preferable that the polyurethane resin (A) contains polyether polyol in an amount of 1 to 40% by mass relative to the polyurethane resin as a constituent component. As the polyether polyol, various known ether polyols that are generally used in the production of polyurethane resins can be used, and one or more types may be used in combination. For example, polyether polyols of polymers or copolymers of ethylene oxide, propylene oxide, tetrahydrofuran, etc. can be mentioned. It is more preferable that the number average molecular weight of the polyether polyol is 100 to 3500.

The polyol, polyisocyanate compound, chain extender, end blocking agent and the like which are used as necessary in the polyurethane resin (A) used in the liquid printing ink composition used in the present invention may be the same as those described above.
The weight average molecular weight of the polyurethane resin (A) is preferably within the range of 10,000 to 100,000, and more preferably within the range of 15,000 to 95,000.

The amount of the urethane resin added is preferably 0.15 to 40% by mass, and more preferably 1.0 to 35% by mass, based on the total amount of the liquid printing ink.

(acrylic resin)
The acrylic resin is not particularly limited as long as it is a copolymer of a polymerizable monomer having a (meth)acrylic acid ester as a main component. Examples of the polymerizable monomer include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, iso-octyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, iso-nonyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, and phenoxyethyl (meth)acrylate. The polymerization method is not particularly limited, and those obtained by known bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization, and the like can be used.
The weight average molecular weight of the acrylic resin is preferably in the range of 5,000 to 200,000, and more preferably in the range of 10,000 to 100,000.
The amount of the acrylic resin added is preferably 0.15 to 40% by mass, and more preferably 1.0 to 35% by mass, based on the total amount of the liquid printing ink.

(Polyester resin)
The polyester resin is not particularly limited as long as it is a polyester resin obtained by reacting an alcohol with a carboxylic acid using a known esterification polymerization reaction.
Examples of the alcohol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-ethyl-2-butyl-1,3propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,2-pentanediol, 3-methyl-1,5-pentanediol, hexanediol, octanediol, 1,4-butynediol, 1,4-butylenediol, diethylene glycol, triethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, 1,2,4-butanetriol, sorbitol, pentaerythritol, 1,4-cyclohexanediol, 1,2-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, spiroglycol, and isosorbide. These may be used alone or in combination of two or more. Among these, polyfunctional alcohols are preferred.
Examples of the carboxylic acid include formic acid, acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, oleic acid, linoleic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, and 1,4-cyclohexanedicarboxylic acid. These may be used alone or in combination of two or more. Among these, polyfunctional carboxylic acids are preferred.
The weight average molecular weight of the polyester resin is preferably 500 to 6000, more preferably 1400 to 5500. The amount of the polyester resin added is preferably 0.15 to 40% by mass, more preferably 1.0 to 35% by mass, based on the total amount of the liquid printing ink.

(Vinyl chloride-vinyl acetate copolymer resin)
As the vinyl chloride resin, vinyl chloride-vinyl acetate copolymer resin is preferred because it is versatile. As the vinyl chloride-vinyl acetate copolymer resin, there is no particular limitation as long as it is a copolymer of vinyl chloride and vinyl acetate. The molecular weight is preferably 5,000 to 100,000 in weight average molecular weight, more preferably 10,000 to 70,000. In 100% by mass of the solid content of the vinyl chloride-vinyl acetate copolymer resin, the structure derived from vinyl acetate monomer is preferably 1 to 30% by mass, and the structure derived from vinyl chloride monomer is preferably 70 to 95% by mass. In this case, the solubility in organic solvents is improved, and further, the adhesion to the substrate, the coating properties, the scratch resistance, etc. are improved.
From the viewpoint of solubility in organic solvents, it is also preferable that the polyvinyl alcohol contains a hydroxyl group derived from a vinyl alcohol structure. The hydroxyl value is preferably 20 to 200 mgKOH/g. The glass transition temperature is preferably 50°C to 90°C.
The amount of vinyl chloride-vinyl acetate copolymer resin added is preferably 0.15 to 40% by mass, and more preferably 1.0 to 35% by mass, based on the total amount of the ink.

(rosin resin)
The rosin resin is not particularly limited as long as it is a resin having a rosin skeleton, but preferred are rosin-modified maleic acid resin, rosin ester, rosin phenol, polymerized rosin, etc. The softening point (by the ring and ball method) is preferably 90 to 200°C.

Among them, the binder resin is preferably a cellulose resin, a polyamide resin, a urethane resin, an acrylic resin, a vinyl chloride resin, or a butyral resin, and it is particularly preferable that the binder resin contains at least two kinds of resins.
Preferably, the combination is selected from the group consisting of urethane resin/vinyl chloride resin, urethane resin/cellulose resin, polyamide resin/cellulose resin, acrylic resin/cellulose resin, and vinyl chloride resin/cellulose resin. The total content of the two resins in 100% by mass of the binder resin (A) is preferably 80 to 100% by mass, and most preferably 90 to 100% by mass.

Furthermore, the mass ratio of urethane resin/vinyl chloride resin, urethane resin/cellulose resin, polyamide resin/cellulose resin, acrylic resin/cellulose resin, and vinyl chloride resin/cellulose resin is preferably 95/5 to 20/80, and more preferably 90/10 to 50/50. This combination provides excellent abrasion resistance, blocking resistance, heat resistance, oil resistance, and other basic properties desired for inks and coatings.

(Hardening agent)
A curing agent may be used in combination with the binder resin (A). As the curing agent, a general-purpose curing agent for organic solvent-based gravure printing inks may be used, but the most commonly used curing agents are isocyanate-based curing agents.
The amount of the isocyanate compound added is preferably in the range of 0.3% by mass to 10.0% by mass, and more preferably 1.0% by mass to 7.0% by mass, based on the solid content of the liquid printing ink, from the viewpoint of curing efficiency.

The binder resin (A) is preferably used in the range of 0.15 to 50% by mass, and most preferably in the range of 1 to 40% by mass, relative to the liquid printing ink.

(Organic solvent)
The organic solvent used in the liquid printing ink used in the present invention is not particularly limited, and examples thereof include aromatic hydrocarbon organic solvents such as toluene, xylene, Solvesso #100, Solvesso #150, etc.; aliphatic hydrocarbon organic solvents such as hexane, methylcyclohexane, heptane, octane, decane, etc.; and various ester-based organic solvents such as methyl acetate, ethyl acetate, isopropyl acetate, normal propyl acetate, butyl acetate, amyl acetate, ethyl formate, butyl propionate, etc. Examples of water-miscible organic solvents include various organic solvents such as alcohols, such as methanol, ethanol, propanol, butanol, and isopropyl alcohol, ketones, such as acetone, methyl ethyl ketone, and cyclohexanone, and glycol ethers, such as ethylene glycol (mono, di) methyl ether, ethylene glycol (mono, di) ethyl ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, monobutyl ether, diethylene glycol (mono, di) methyl ether, diethylene glycol (mono, di) ethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, triethylene glycol (mono, di) methyl ether, propylene glycol (mono, di) methyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, and dipropylene glycol (mono, di) methyl ether. These can be used alone or in combination of two or more.

In addition, from the standpoint of both work hygiene during printing and the harmfulness of packaging materials, it is more preferable to use ethyl acetate, propyl acetate, isopropanol, normal propanol, etc., and not use aromatic solvents such as toluene or ketone-based solvents such as methyl ethyl ketone.

(Coloring Agent)
The liquid printing ink used in the present invention contains a colorant and can be used as a liquid printing ink containing a colorant for design printing or the like for the purpose of imparting cosmetic properties, etc. Examples of the colorant include inorganic pigments, organic pigments and dyes used in general inks, paints, and recording agents, etc., and pigments are preferred. Examples of organic pigments include soluble azo-based, insoluble azo-based, azo-based, phthalocyanine-based, halogenated phthalocyanine-based, anthraquinone-based, anthanthrone-based, dianthraquinonyl-based, anthrapyrimidine-based, perylene-based, perinone-based, quinacridone-based, thioindigo-based, dioxazine-based, isoindolinone-based, quinophthalone-based, azomethine azo-based, flavanthrone-based, diketopyrrolopyrrole-based, isoindoline-based, indanthrone-based, carbon black-based, and other pigments. In addition, examples of the pigments include carmine 6B, lake red C, permanent red 2B, disazo yellow, pyrazolone orange, carmine FB, chromophthalic yellow, chromophthalic red, phthalocyanine blue, phthalocyanine green, dioxazine violet, quinacridone magenta, quinacridone red, indanthrone blue, pyrimidine yellow, thioindigo bordeaux, thioindigo magenta, perylene red, perinone orange, isoindolinone yellow, aniline black, diketopyrrolopyrrole red, and daylight fluorescent pigments. In addition, both non-acid-treated pigments and acid-treated pigments can be used. Specific examples of preferred organic pigments are given below.

Examples of black pigments include C.I. Pigment Black 1, C.I. Pigment Black 6, C.I. Pigment Black 7, C.I. Pigment Black 9, and C.I. Pigment Black 20.

Examples of indigo pigments include C.I. Pigment Blue 15, C.I. Pigment Blue 15:1, C.I. Pigment Blue 15:2, C.I. Pigment Blue 15:3, C.I. Pigment Blue 15:4, C.I. Pigment Blue 15:5, C.I. Pigment Blue 15:6, C.I. Pigment Blue 16, C.I. Pigment Blue 17:1, C.I. Pigment Blue 22, C.I. Pigment Blue 24:1, C.I. Pigment Blue 25, C.I. Pigment Blue 26, C.I. Pigment Blue 60, C.I. Pigment Blue 61, C.I. Pigment Blue 62, C.I. Pigment Blue 63, C.I. Pigment Blue 64, C.I. Pigment Blue 75, C.I. Pigment Blue 79, C.I. Pigment Blue 80, etc.

Examples of green pigments include C.I. Pigment Green 1, C.I. Pigment Green 4, C.I. Pigment Green 7, C.I. Pigment Green 8, C.I. Pigment Green 10, and C.I. Pigment Green 36.

Examples of red pigments include C.I. Pigment Red 1, C.I. Pigment Red 2, C.I. Pigment Red 3, C.I. Pigment Red 4, C.I. Pigment Red 5, C.I. Pigment Red 6, C.I. Pigment Red 7, C.I. Pigment Red 8, C.I. Pigment Red 9, C.I. Pigment Red 10, C.I. Pigment Red 11, C.I. Pigment Red 12, C.I. Pigment Red 15, C.I. Pigment Red 16, C.I. Pigment Red 17, C.I. Pigment Red 18, C.I. Pigment Red 19, C.I. Pigment Red 20, C.I. Pigment Red 21, C.I. Pigment Red 22, C.I. Pigment Red 23, C.I. Pigment Red 31, C.I. Pigment Red 32, C.I. Pigment Red 38, C.I. Pigment Red 41, C.I. Pigment Red 43, C.I. Pigment Red 46, C.I. Pigment Red 48, C.I. Pigment Red 48:1, C.I. Pigment Red 48:2, C.I. Pigment Red 48:3, C.I. Pigment Red 48:4, C.I. Pigment Red 48:5, C.I. Pigment Red 48:6, C.I. Pigment Red 49, C.I. Pigment Red 49:1, C.I. C.I. Pigment Red 49:2, C.I. Pigment Red 49:3, C.I. Pigment Red 52, C.I. Pigment Red 52:1, C.I. Pigment Red 52:2, C.I. Pigment Red 53, C.I. Pigment Red 53:1, C.I. Pigment Red 53:2, C.I. Pigment Red 53:3, C.I. Pigment Red 54, C.I. Pigment Red 57, C.I. Pigment Red 57:1, C.I. Pigment Red 58, C.I. Pigment Red 58:1, C.I. Pigment Red 58:2, C.I. Pigment Red 58:3, C.I. Pigment Red 58:4, C.I. C.I. Pigment Red 60:1, C.I. Pigment Red 63, C.I. Pigment Red 63:1, C.I. Pigment Red 63:2, C.I. Pigment Red 63:3, C.I. Pigment Red 64:1, C.I. Pigment Red 68, C.I. Pigment Red 68, C.I. Pigment Red 81:1, C.I. Pigment Red 83, C.I. Pigment Red 88, C.I. Pigment Red 89, C.I. Pigment Red 95, C.I. Pigment Red 112, C.I. Pigment Red 114, C.I. Pigment Red 119, C.I. Pigment Red 122, C.I. Pigment Red 123, C.I. Pigment Red 136, C.I. Pigment Red 144, C.I. Pigment Red 146, C.I. Pigment Red 147, C.I. Pigment Red 149, C.I. Pigment Red 150, C.I. Pigment Red 164, C.I. Pigment Red 166, C.I. Pigment Red 168, C.I. Pigment Red 169, C.I. Pigment Red 170, C.I. Pigment Red 171, C.I. Pigment Red 172, C.I. Pigment Red 175, C.I. Pigment Red 176, C.I. Pigment Red 177, C.I. Pigment Red 178, C.I. Pigment Red 179, C.I. Pigment Red 180, C.I. Pigment Red 181, C.I. Pigment Red 182, C.I. Pigment Red 183, C.I. Pigment Red 184, C.I. Pigment Red 185, C.I. Pigment Red 187, C.I. Pigment Red 188, C.I. Pigment Red 190, C.I. Pigment Red 192, C.I. Pigment Red 193, C.I. Pigment Red 194, C.I. Pigment Red 200, C.I. Pigment Red 202, C.I. Pigment Red 206, C.I. Pigment Red 207, C.I. Pigment Red 208, C.I. Pigment Red 209, C.I. Pigment Red 210, C.I. Pigment Red 211, C.I. Pigment Red 213, C.I. Pigment Red 214, C.I. Pigment Red 216, C.I. Pigment Red 215, C.I. Pigment Red 216, C.I. Pigment Red 220, C.I. Pigment Red 221, C.I. Pigment Red 223, C.I. Pigment Red 224, C.I. Pigment Red 226, C.I. Pigment Red 237, C.I. Pigment Red 238, C.I. Pigment Red 239, C.I. Pigment Red 240, C.I. Pigment Red 242, C.I. Pigment Red 245, C.I. Pigment Red 247, C.I. Pigment Red 248, C.I. Pigment Red 251, C.I. Pigment Red 253, C.I. Pigment Red 254, C.I. Pigment Red 255, C.I. Pigment Red 256, C.I. Pigment Red 257, C.I. Pigment Red 258, C.I. Pigment Red 260, C.I. Pigment Red 262, C.I. Pigment Red 263, C.I. Pigment Red 264, C.I. Pigment Red 266, C.I. Pigment Red 268, C.I. Pigment Red 269, C.I. Pigment Red 270, C.I. Pigment Red 271, C.I. Pigment Red 272, C.I. Pigment Red 279, etc.

Examples of purple pigments include C.I. Pigment Violet 1, C.I. Pigment Violet 2, C.I. Pigment Violet 3, C.I. Pigment Violet 3:1, C.I. Pigment Violet 3:3, C.I. Pigment Violet 5:1, C.I. Pigment Violet 13, C.I. Pigment Violet 19 (γ type, β type), C.I. Pigment Violet 23, C.I. Pigment Violet 25, C.I. Pigment Violet 27, C.I. Pigment Violet 29, C.I. Pigment Violet 31, C.I. Pigment Violet 32, C.I. Pigment Violet 36, C.I. Pigment Violet 37, C.I. Pigment Violet 38, C.I. Pigment Violet 42, C.I. Pigment Violet 50, etc.

Examples of yellow pigments include C.I. Pigment Yellow 1, C.I. Pigment Yellow 3, C.I. Pigment Yellow 12, C.I. Pigment Yellow 13, C.I. Pigment Yellow 14, Pigment Yellow 17, C.I. Pigment Yellow 24, C.I. Pigment Yellow 42, C.I. Pigment Yellow 55, C.I. Pigment Yellow 62, C.I. Pigment Yellow 65, C.I. Pigment Yellow 74, C.I. Pigment Yellow 83, C.I. Pigment Yellow 86, C.I. Pigment Yellow 93, C.I. Pigment Yellow 94, C.I. Pigment Yellow 95, C.I. Pigment Yellow 109, C.I. Pigment Yellow 110, C.I. Pigment Yellow 117, C.I. Pigment Yellow 120, Pigment Yellow 125, C.I. Pigment Yellow 128, C.I. Pigment Yellow 129, C.I. Pigment Yellow 137, C.I. Pigment, Yellow 138, C.I. Pigment Yellow 139, C.I. Pigment Yellow 147, C.I. Pigment Yellow 148, C.I. Pigment Yellow 150, C.I. Pigment Yellow 151, C.I. Pigment Yellow 153, C.I. Pigment Yellow 154, C.I. Pigment Yellow 155, C.I. Pigment Yellow 166, C.I. Pigment Yellow 168, C.I. Examples of the pigments include C.I. Pigment Yellow 174, C.I. Pigment Yellow 180, C.I. Pigment Yellow 185, and C.I. Pigment Yellow 213.

Examples of orange pigments include C.I. Pigment Orange 5, C.I. Pigment Orange 13, C.I. Pigment Orange 16, C.I. Pigment Orange 34, C.I. Pigment Orange 36, C.I. Pigment Orange 37, C.I. Pigment Orange 38, C.I. Pigment Orange 43, C.I. Pigment Orange 51, C.I. Pigment Range 55, C.I. Pigment Orange 59, C.I. Pigment Orange 61, C.I. Pigment Orange 64, C.I. Pigment Orange 71, and C.I. Pigment Orange 74.

Examples of brown pigments include C.I. Pigment Brown 23, C.I. Pigment Brown 25, and C.I. Pigment Brown 26.

Among them, preferred pigments include C.I. Pigment Black 7 as a black pigment,
Indigo pigments include C.I. Pigment Blue 15, C.I. Pigment Blue 15:1, C.I. Pigment Blue 15:2, C.I. Pigment Blue 15:3, C.I. Pigment Blue 15:4, C.I. Pigment Blue 15:6,
As a green pigment, C.I. Pigment Green 7,
Red pigments include C.I. Pigment Red 57:1, C.I. Pigment Red 48:1, C.I. Pigment Red 48:2, C.I. Pigment Red 48:3, C.I. Pigment Red 146, C.I. Pigment Red 242, C.I. Pigment Red 185, C.I. Pigment Red 122, C.I. Pigment Red 178, C.I. Pigment Red 149, C.I. Pigment Red 144, C.I. Pigment Red 166,
As purple pigments, C.I. Pigment Violet 23, C.I. Pigment Violet 37,
Yellow pigments include C.I. Pigment Yellow 83, C.I. Pigment Yellow 14, C.I. Pigment Yellow 180, C.I. Pigment Yellow 139,
Orange pigments include C.I. Pigment Orange 38, C.I. Pigment Orange 13, C.I. Pigment Orange 34, C.I. Pigment Orange 64,
It is preferable to use at least one or two or more selected from these groups.

Examples of inorganic pigments include white inorganic pigments such as titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, silica, lithopone, antimony white, and gypsum. Among inorganic pigments, the use of titanium oxide is particularly preferred. Titanium oxide exhibits a white color and is preferred in terms of coloring power, hiding power, chemical resistance, and weather resistance, and from the standpoint of printing performance, the titanium oxide is preferably treated with silica and/or alumina.

Examples of inorganic pigments other than white include aluminum particles, mica, bronze powder, chrome vermilion, yellow lead, cadmium yellow, cadmium red, ultramarine, Prussian blue, iron oxide red, yellow iron oxide, iron black, and zircon. Aluminum is in powder or paste form, but it is preferable to use it in paste form from the standpoint of ease of handling and safety, and whether leafing or non-leafing is used is selected appropriately from the standpoint of brightness and concentration.

The above pigments are preferably contained in an amount sufficient to ensure the concentration and coloring power of the liquid printing ink, i.e., 1 to 60% by mass of the total mass of the liquid printing ink, or 10 to 90% by mass in terms of the weight ratio of solids in the liquid printing ink. These pigments can be used alone or in combination of two or more kinds.

Organic solvent-based liquid printing inks may also contain waxes, chelating crosslinking agents, extender pigments, leveling agents, defoamers, plasticizers, infrared absorbers, ultraviolet absorbers, fragrances, flame retardants, etc., as necessary.

(Biomass liquid printing ink)
In the liquid printing ink used in the present invention, in consideration of the establishment of a recycling-based society that should develop in a sustainable manner (sustainability), it is preferable to use a liquid printing ink that uses raw materials derived from plants.
Examples of plant-derived raw materials include cellulose resins such as cellulose acetate propionate resin and nitrocellulose; polyamide resins using dimer acids or polymerized fatty acids derived from natural oils such as soybean oil, palm oil, and rice bran oil; polycarboxylic acids such as succinic acid, succinic anhydride, adipic acid, azelaic acid, sebacic acid, dimer acid, glutaric acid, and malic acid; polyols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, pentylene glycol, 1,10-dodecanediol, dimer diol, and isosorbide; and polyisocyanates such as 1,5-pentamethylene diisocyanate and dimer diisocyanate. Examples of plant-derived raw materials include biomass polyurethanes and rosin resins.

Commercially available products can be used as biomass liquid printing ink. Examples of commercially available products that can be used include the inks listed by the Japan Organics Resources Association.

<Other demographics>
(Overcoat Layer)
The laminate of the present invention may further include an overcoat layer on the printed layer in order to improve gloss, scratch resistance, and heat resistance. The overcoat agent for forming the overcoat layer is not particularly limited, but may be an ink composition having the same composition as the ink composition used in the printed layer and not containing a pigment for coloring (although it may contain an extender pigment), or an active energy ray curable ink. The overcoat agent may also be a resin coating agent such as an acrylic resin, a urethane resin, an acrylic urethane resin, or an epoxy resin.

The above overcoat agents can also be commercially available.

In consideration of sustainability, it is preferable that the overcoat agent also contains plant-derived materials. Such overcoat agents can be commercially available as biomass-certified products. Specifically, varnishes and the like listed by the Japan Organics Resources Association can be used.

(Other Base Layers)
The laminate of the present invention may further include another substrate layer. The other substrate layer is not particularly limited and may be a multilayer film similar to the first substrate layer, a multilayer film different from the first substrate layer, a sealant film, or a paper substrate such as plain paper or coated paper, a plastic film such as an unstretched film or a stretched film, or a nonwoven fabric, but is preferably formed from a thermoplastic resin. Also, it is preferably a sealant film having a heat seal function.

Examples of the plastic film include OPP film, PET film, nylon film (hereinafter, sometimes referred to as Ny film), etc. In addition, the plastic film may be coated with a coating for the purpose of improving gas barrier properties and ink receptivity when a printing layer is provided, which will be described later. Examples of commercially available coated plastic films include K-OPP film and K-PET film.
Examples of the sealant film include a CPP film and an LLDPE film.

The second substrate layer used in the present invention may be formed from a biomass polyolefin. The biomass polyolefin refers to a polyolefin resin that uses a plant-derived olefin as the raw material monomer. The raw material monomer may contain a petroleum-derived monomer, and does not have to contain 100% plant-derived monomer.

As the biomass polyolefin, commercially available products can also be used. Examples of commercially available products include SGM9450F, SLL118, SLL118/21, SLL218, SLL318, SLH118, SLH218, and SLH0820 manufactured by Braskem.

(Barrier Layer)
The laminate of the present invention may further include a barrier layer in order to impart or improve gas barrier properties that prevent the transmission of oxygen gas and water vapor, etc., and light blocking properties that prevent the transmission of visible light, ultraviolet rays, etc. The barrier layer is preferably composed of a metal vapor deposition film or metal foil. The type of vapor deposition layer is not particularly limited as long as it can impart gas barrier properties. Suitable examples include metal vapor deposition and metal oxide vapor deposition, which are currently widely used for packaging. Examples of metal vapor deposition include various metals, but aluminum, which is inexpensive and widely used, is particularly preferred. A transparent vapor deposition film may also be used as the barrier layer.

There are no particular limitations on the deposition method, and examples include vacuum deposition, which is a physical deposition method, sputtering, ion plating, and CVD, which is a chemical deposition method. There are no particular limitations on the thickness of the deposition layer, so long as the deposition layer alone can exhibit a certain level of gas barrier function. The preferred range of thickness varies depending on the type of metal or metal oxide to be deposited, but is preferably 0.05 to 70 nm, more preferably 0.1 to 70 nm, more preferably 3 to 70 nm, and even more preferably 5 to 60 nm.

As the metal vapor deposition film, a VM-CPP film in which a metal such as aluminum is vapor-deposited on a CPP film, or a VM-OPP film in which a metal such as aluminum is vapor-deposited on an OPP film can be used. In addition, as the transparent vapor deposition film, a film in which silica or alumina is vapor-deposited on an OPP film, PET film, nylon film, etc. can be used. For the purpose of protecting the inorganic vapor deposition layer of silica or alumina, a film with a coating applied on the vapor deposition layer can also be used.

The laminate of the present invention may also have two or more barrier layers. When the laminate has two or more barrier layers, each layer may have the same composition or different compositions.

(Adhesive Layer)
The laminate of the present invention may further include an adhesive layer as another layer. The adhesive layer has a function of adhering any two layers constituting the laminate, for example, the first base material layer and the other base material layer. The adhesive layer is preferably, but is not limited to, a cured coating film of a two-component curing adhesive of a polyol composition and a polyisocyanate composition.

<Method of manufacturing laminate>
The method for producing the laminate of the present invention is not particularly limited, and for example, the laminate can be produced by laminating a printed layer on the surface layer (A) side of the multilayer film by a known printing method such as gravure printing using a gravure printing plate by electronic engraving intaglio or the like, or flexographic printing using a flexographic printing plate by a resin plate, etc. The printed layer may be laminated on the entire surface of the surface layer (A) side, or may be laminated only on a part of the surface of the surface layer (A) side.
For lamination of the other layers, the film can be manufactured by laminating an adhesive layer, a second base material layer, and a barrier layer using a known method such as dry lamination, wet lamination, non-solvent lamination, extrusion lamination, etc. In addition, the film can be manufactured by further laminating an overcoat layer by a known printing method. The order of lamination of the other layers and the printing layer is not particularly limited, and for example, the printing layer may be laminated on the multilayer film and then the second base material layer may be laminated by dry lamination, or the second base material layer may be laminated on the multilayer film by dry lamination and then the printing layer may be laminated.

The laminate of the present invention has excellent adhesion between the multilayer film and the ink that is the printing layer. Therefore, the ink is less likely to peel off from the multilayer film, and a good appearance can be obtained.

The laminate of the present invention can be subjected to secondary processing to impart mechanical, chemical, electrical, magnetic, slipping functions for controlling friction/wear/lubrication, optical, thermal, biocompatibility, and other functions. Examples of secondary processing include surface treatments (corona discharge treatment, antistatic treatment, plasma treatment, photochromism treatment, physical vapor deposition, chemical vapor deposition, coating, etc.), embossing, painting, adhesion, printing, metallizing (plating, etc.), and machining. The laminate of the present invention can also be subjected to lamination (dry lamination and extrusion lamination), bag making, and other post-processing to manufacture molded products.

<Packaging materials>
The laminate of the present invention can be used as a packaging material, such as packaging bags, containers, and container lids for foods, medicines, industrial parts, miscellaneous goods, magazines, etc.

The above-mentioned package can be produced by overlapping the seal layers (C) of the multilayer film used in the present invention and heat sealing them, or by overlapping the exposed surface layer (A) without a printed layer and the seal layer (C) and heat sealing them to produce a packaging bag with the seal layer (C) of the multilayer film on the inside. For example, two sheets of the multilayer film can be cut to the desired size of the packaging bag, overlapped and heat sealed on three sides to form a bag, and then filled with contents from the one side that is not heat sealed and heat sealed to seal it. It is also possible to form a packaging bag by sealing the ends of a roll-shaped film into a cylindrical shape using an automatic packaging machine, and then sealing the top and bottom.

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

(Production of multilayer film (1))
The surface layer (A) was made of 100 parts of a propylene-ethylene block copolymer (density: 0.90 g/cm ³ , MFR: 5 g/10 min). The intermediate layer (B) was made of a mixture of 65 parts of a propylene-based block copolymer (density: 0.90 g/cm ³ , MFR: 6 g/10 min), 22 parts of a sugar cane-derived linear low-density polyethylene (Braskem SLH218, density: 0.916 g/cm ³ , MFR: 2.3 g/10 min), and 13 parts of a linear low-density polyethylene (density: 0.905 g/cm ³ , MFR: 3 g/10 min). The sealing layer (C) was made of a mixture of 70 parts of a propylene-ethylene copolymer (density: 0.90 g/cm ^{3 , MFR: 5 g/10 min), 1-butene-propylene copolymer (density: 0.90 g/cm 3} , MFR: 5 g/10 min), and 1-butene-propylene copolymer (density: 0.90 g/cm 3 , MFR: 5 g/10 min). ^A mixture of 30 parts of a 100% polyester resin (100% polyester resin, ...

(Production of multilayer film (2))
The surface layer (A) was made of 100 parts of propylene homocopolymer (density: 0.90 g/cm ³ , MFR: 9 g/10 min). The intermediate layer (B) was made of a mixture of 85 parts of propylene homocopolymer (density: 0.90 g/cm ³ , MFR: 6 g/10 min), 8.5 parts of sugarcane-derived linear low-density polyethylene (Braskem SLH218, density: 0.916 g/cm ³ , MFR: 2.3 g/10 min), 4.5 parts of linear low-density polyethylene (density: 0.905 g/cm ³ , MFR: 3 g/10 min), and 2.0 parts of high-density polyethylene (density: 0.955 g/cm ³ , MFR: 18 g/10 min). The sealing layer (C) was made of a mixture of propylene-ethylene copolymer (density: 0.90 g/cm ³ , MFR: 1.0 g/10 min). A 30 μm-thick three-layer film was produced by coextrusion using 100 parts of a 100% polyester resin (polyethylene glycol terephthalate, MFR: 5 g/10 min) so that the average thickness of the surface layer (A), intermediate layer (B) and seal layer (C) was 3:14:3. The surface layer (A) side of this film was subjected to a corona discharge treatment so that the surface energy was 35 mN/m, thereby producing a multilayer film (2).

(Production of multilayer film (3))
The surface layer (A) was made of 100 parts of propylene homocopolymer (density: 0.90 g/cm ³ , MFR: 7 g/10 min), the intermediate layer (B) was made of a mixture of 50 parts of sugarcane-derived linear low-density polyethylene (Braskem SLH218, density: 0.916 g/cm ³ , MFR: 2.3 g/10 min) and 50 parts of linear low-density polyethylene (density: 0.905 g/cm ³ , MFR: 4 g/10 min), and the sealing layer (C) was made of a mixture of 60 parts of propylene-ethylene copolymer (density: 0.90 g/cm ³ , MFR: 7 g/10 min), 30 parts of propylene-ethylene-butene terpolymer (density: 0.90 g/cm ³ , MFR: 4 g/10 min) and ethylene-butene copolymer (density: 0.90 g/cm ³ , MFR: 4 g/10 min). A mixture of 10 parts of a 100% polyester resin (100% polyester, MFR: 4 g/10 min) was co-extruded so that the average thickness of the surface layer (A), intermediate layer (B) and seal layer (C) was 7:10:3 to obtain a three-layer film having a thickness of 30 μm. The surface layer (A) side of this film was subjected to a corona discharge treatment so that the surface energy was 35 mN/m to produce a multilayer film (3).

Example 1
A printed layer was formed on the surface layer (A) of the multilayer film (1) by printing with a liquid printing ink, Glossa BM Indigo (manufactured by DIC Graphics Corporation), to obtain a laminate of Example 1.

Example 2
A laminate of Example 2 was obtained in the same manner as in Example 1, except that the liquid printing ink was changed to Raijin Aoi (manufactured by DIC Graphics Corporation).

Example 3
A laminate of Example 3 was obtained in the same manner as in Example 1, except that the liquid printing ink was changed to Ultima NT Indigo (manufactured by DIC Graphics Corporation).

Example 4
A laminate of Example 4 was obtained in the same manner as in Example 1, except that the multilayer film (1) was changed to the multilayer film (2).

Example 5
A laminate of Example 5 was obtained in the same manner as in Example 2, except that the multilayer film (1) was changed to the multilayer film (2).

Example 6
A laminate of Example 6 was obtained in the same manner as in Example 3, except that the multilayer film (1) was changed to the multilayer film (2).

Example 7
A laminate of Example 7 was obtained in the same manner as in Example 1, except that the multilayer film (1) was changed to the multilayer film (3).

Example 8
A laminate of Example 8 was obtained in the same manner as in Example 2, except that the multilayer film (1) was changed to the multilayer film (3).

<Example 9>
A laminate of Example 9 was obtained in the same manner as in Example 3, except that the multilayer film (1) was changed to the multilayer film (3).

<Method for evaluating ink adhesion>
Cellophane tape (manufactured by Nichiban Co., Ltd.) was applied to the printed surface of each of the laminates of Examples 1 to 9, and the tape was then quickly peeled off, and the condition of the printed surface was visually evaluated. A rating of 4 or higher is within the practical range.
(Evaluation criteria)
5: The printed film does not peel off at all from the film.
4: Less than 20% of the area of the printed film peeled off from the film.
3: 20% or more and less than 50% of the area of the printed film peels off from the film.
2: 50% or more and less than 80% of the area of the printed film peels off from the film.
1: 80% or more of the area of the printed surface is peeled off from the film.

The laminate structures and ink adhesion evaluation results for Examples 1 to 9 are shown in Table 1.

The structure of the laminates in Examples 7 to 9 and the evaluation results of ink adhesion are shown in Table 2.

The products used in the printing layers described in Tables 1 and 2 are as follows:
Ultima NT507 Primary color blue YDIC Graphics Corporation Raizin 507 Primary color blue DIC Graphics Corporation Glossa 507 Primary color blue S2DIC Graphics Corporation

The laminates of Examples 1 to 9, which are the laminates of the present invention, had excellent ink adhesion. Furthermore, each layer contained a large amount of plant-derived raw materials, and the biomass content of the entire laminate was high.

Claims (5)

A laminate in which at least a first base material layer and a printing layer are laminated,
(1) The first base layer is
The coating composition has a surface layer (A), an intermediate layer (B), and a sealing layer (C),
The surface layer (A) contains a propylene-based resin,
The intermediate layer (B) contains biomass polyethylene,
The sealing layer (C) is a multilayer film containing a propylene-ethylene copolymer,
(2) A laminate, wherein the printed layer is a layer formed by printing with a liquid printing ink.
The laminate according to claim 1 , wherein the printed layer is a layer formed by printing with a liquid printing ink containing a plant-derived raw material.
The laminate according to claim 1, in which the printed layer is on the surface layer (A) side of the first substrate layer. A packaging material using the laminate according to any one of claims 1 to 3. The packaging material according to claim 4, which is a food packaging bag.