Barrier laminate, packaging body, and method for producing barrier laminate

Abstract

Provided is a barrier laminate that exhibits high roll-to-roll stability and effectively suppresses deterioration in barrier properties due to stress even when a paper base material having large surface roughness is used.　The barrier laminate comprises the paper base material, a thermoplastic adhesive resin layer, a barrier layer, and a heat seal layer in this order. The surface roughness Ra on the thermoplastic adhesive resin layer side of the paper base material is 2.0 μm or greater, and the thermoplastic adhesive resin layer contains a polyethylene-based resin.

Description

Barrier laminate, packaging, and method for manufacturing a barrier laminate

[0001] The present invention relates to a barrier laminate comprising a paper substrate, a packaging, and a method for manufacturing a barrier laminate.

[0002] From the perspective of reducing environmental impact, there are plans to improve recyclability by switching from conventional packaging materials, which are composed of laminates made of multiple plastic films, to paper-based compositions. Furthermore, since even paper-based compositions need to have gas barrier properties against oxygen and water vapor, barrier laminates using paper substrates are also being considered.

[0003] Patent Document 1 discloses a barrier laminate comprising a paper substrate, an adhesive layer, an inorganic vapor-deposited film, and a heat-seal layer, and optionally comprising an anchor coat layer between the inorganic vapor-deposited film and the heat-seal layer (Patent Document 1).

[0004] International Public Gazette WO2022 / 203056

[0005] Now, in packaging bags made of barrier laminates primarily composed of paper substrates, depending on the packaging form and application, paper substrates with high basis weight and high surface roughness may be used.

[0006] However, in barrier laminates in which a barrier layer is laminated to the surface of a paper substrate via an adhesive layer, if a paper substrate with a large surface roughness is used, the adhesive layer may not be able to adequately conform to the surface of the paper substrate, resulting in a laminate with partial lifting between the paper substrate and the transfer film. Our research has revealed that this can cause the adhesive layer in the barrier laminate to peel off due to stress, reducing the barrier properties of the barrier laminate.

[0007] Furthermore, our research has revealed that when manufacturing barrier laminates using paper substrates with high basis weight and high surface roughness, if an intermediate laminate with a release film laminated on a heat seal layer is transported by roll-to-roll, the laminate is laminated with partial lifting between the paper substrate and the transfer film. This can cause wrinkles to form in the laminate during roll-to-roll transport or when peeling off the release film after roll-to-roll transport, and make it difficult to peel off the release film cleanly. In this specification, the occurrence of wrinkles in such laminates and the peelability of the release film are referred to as RtoR stability (roll-to-roll stability).

[0008] The present invention aims to provide a barrier laminate that effectively suppresses the reduction in barrier properties due to stress, even when using a paper substrate with a large surface roughness, and that has high RtoR stability.

[0009] The inventors of the present invention conducted diligent research to solve the above problems and found that by laminating a barrier layer on the surface of a paper substrate via a thermoplastic adhesive resin layer containing a polyethylene-based resin, the reduction in barrier properties due to stress is effectively suppressed and the RtoR stability is also improved, thus completing the present invention. Specifically, the present invention provides the following.

[0010] (1) A barrier laminate comprising, in this order, a paper substrate, a thermoplastic adhesive resin layer, a barrier layer, and a heat seal layer, wherein the surface roughness Ra of the paper substrate on the thermoplastic adhesive resin layer side is 2.0 μm or more, and the thermoplastic adhesive resin layer contains a polyethylene resin.

[0011] (2) The barrier laminate of (1), wherein the melt flow rate (MFR) of the thermoplastic adhesive resin layer at 190°C and a load of 2.16 kg, as measured according to JIS K7210, is 3 g / 10 min or more and 30 g / 10 min or less.

[0012] (3) The barrier laminate of (1), wherein the polyethylene resin is an acid-modified polyethylene resin.

[0013] (4) The barrier laminate according to (1), wherein the air permeability of the paper base material is 60 sec or less as measured by JIS 8119 (Bekk method).

[0014] (5) The barrier laminate according to (1), wherein the indentation hardness of the thermoplastic adhesive resin layer is 45 MPa or less.

[0015] (6) The barrier laminate according to (1), wherein the complex elastic modulus of the thermoplastic adhesive resin layer is 0.5 GPa or less.

[0016] (7) The barrier laminate according to (1), wherein the basis weight of the paper base material is 120 g / m ２ or more.

[0017] (8) A package in which the contents are packaged using the barrier laminate according to any one of (1) to (7), wherein at least a part of the peripheral edge of the barrier laminate has the heat-sealing layers facing each other and heat-sealed so that the contents are hermetically packaged.

[0018] (9) A package in which the contents are packaged using the barrier laminate according to any one of (1) to (7), wherein a second heat-sealing layer identical to or different from the heat-sealing layer is laminated on the paper base material of the barrier laminate, and at least a part of the peripheral edge of the barrier laminate has the heat-sealing layer and the second heat-sealing layer overlapping and heat-sealed so that the contents are hermetically packaged.

[0019] (10) A method for producing a barrier laminate, comprising a paper base material, a thermoplastic adhesive resin layer, a barrier layer, and a heat-sealing layer in this order, wherein the surface roughness Ra on the surface of the paper base material on the side of the thermoplastic adhesive resin layer is 2.0 μm or more, and the method includes a step of forming the thermoplastic adhesive resin layer by melt-extruding a thermoplastic resin containing a polyethylene-based resin.

[0020] According to the present invention, even when a paper base material having a large surface roughness is used, it is possible to effectively suppress a decrease in barrier properties due to stress and provide a barrier laminate with high RtoR stability.

[0021] This is a laminated structure diagram (cross-sectional view) showing an example of the layer structure of a barrier laminate. This is a laminated structure diagram (cross-sectional view) showing another example of the layer structure of a barrier laminate. This is a laminated structure diagram (cross-sectional view) showing an example of the layer structure of a transfer film. This is a diagram showing one embodiment of a package formed using a barrier laminate. This is a diagram showing one embodiment of a package formed using a barrier laminate. This is a diagram showing one embodiment of a package formed using a barrier laminate. This is a diagram showing one embodiment of a package formed using a barrier laminate. This is a diagram illustrating the deterioration of the barrier properties of a barrier laminate due to stress. This is a diagram illustrating the deterioration of the barrier properties of a barrier laminate due to stress.

[0022] The following describes specific embodiments of the present invention in detail. However, the present invention is not limited to the following embodiments and can be implemented with appropriate modifications within the scope of the object of the present invention. In this specification, the notation "X to Y" (where X and Y are arbitrary numerical values) means "X or greater and Y or less".

[0023] <<One Embodiment of a Barrier Laminate>> In one embodiment, the barrier laminate of the present invention comprises a base material layer such as a paper substrate, a thermoplastic adhesive resin layer, a barrier layer, and a heat seal layer in this order in the thickness direction.

[0024] In this specification, "stacking in this order" means not only that each layer is stacked directly without any intermediaries, but also that each layer is stacked indirectly with respect to other layers.

[0025] Furthermore, the barrier laminate of the present invention is characterized in that a barrier layer is laminated to the surface of a paper substrate via a thermoplastic adhesive resin layer containing a polyethylene-based resin. By using a thermoplastic adhesive resin layer containing a polyethylene-based resin, it is possible to effectively suppress the decrease in barrier properties due to stress, even when using a paper substrate with a large surface roughness, and to obtain a barrier laminate with high RtoR stability.

[0026] Furthermore, in one embodiment, the barrier laminate of the present invention includes a printing layer on the side of the paper substrate layer opposite to the thermoplastic adhesive resin layer. Also, in one embodiment, the barrier laminate of the present invention includes a surface heat seal layer on the side of the paper substrate layer opposite to the thermoplastic adhesive resin layer, or on the side of the printing layer opposite to the substrate layer. Moreover, in one embodiment, the barrier laminate of the present invention may include a protective layer between the barrier layer and the thermoplastic adhesive resin layer. Also, in one embodiment, the barrier laminate of the present invention may further include an anchor coat layer between the barrier layer and the heat seal layer. Here, the barrier layer and the heat seal layer or anchor coat layer (if an anchor coat layer is provided) may be in contact. Note that the barrier laminate of this embodiment may or may not include a release layer between the barrier layer and the heat seal layer.

[0027] Figure 1 is a cross-sectional view of an example of the layer structure of a barrier laminate. The barrier laminate 1 (1A) shown in Figure 1 consists of a printing layer 4, a base material layer (paper base material) 2, a thermoplastic adhesive resin layer 3, a protective layer 14, a barrier layer 13, an anchor coat layer 12, and a heat seal layer 11, all laminated in this order in the thickness direction. Of the layer structure of the barrier laminate 1 (1A) shown in Figure 1, the protective layer 14, barrier layer 13, anchor coat layer 12, and heat seal layer 11 are configured as a transfer layer 10, and are bonded to the base material layer 2 via the thermoplastic adhesive resin layer 3 by a method described later. The transfer film 30 having the transfer layer 10 will be described in detail later.

[0028] In one embodiment, the transfer layer 10 used in the barrier laminate 1 of the present invention does not have a release layer between the heat seal layer 11 and the barrier layer 13, resulting in high adhesion strength between these layers. Therefore, the barrier laminate 1A of one embodiment of the present invention has suppressed delamination during the manufacturing process and during use.

[0029] Here, the release layer is a layer typically provided as the surface layer on the transfer support side of the transfer layer in a conventional transfer film comprising a transfer support and a transfer layer, in order to improve the peelability of the transfer layer from the transfer support. That is, the transfer layer includes a release layer as the surface layer on the transfer support side.

[0030] A release layer is typically a layer containing a release agent. Examples of release agents include waxes such as silicone wax, silicone oil, silicone resins, fluororesins, and phosphate esters. In one embodiment, the release layer contains a resin component. Examples of resin components include polyolefin resins, vinyl resins, styrene resins, (meth)acrylic resins, polyester resins, polyurethane resins, polycarbonate resins, polyamide resins, polyimide resins, and cellulose resins.

[0031] Next, we will describe an example of each layer that makes up the layers of a barrier laminate.

[0032] <Base Layer 2> Base layer 2 uses a paper base material. This paper base material has a basis weight of 150 g / m². ２ The above-mentioned paper substrate has a surface roughness Ra of 2.0 μm or more. Examples of such paper substrates include kraft paper, pure white roll paper, fine paper, medium-quality paper, glassine paper, Kent paper, processed paper, cardboard, and synthetic paper. As the paper substrate, a paper substrate in which a sealing layer or resin layer is formed on one or both sides of the paper material may be used, such as clay-coated paper, lightly coated printing paper, coated printing paper (e.g., coated paper, cast-coated paper, and art paper), resin-coated paper, release paper, and double-sided coated release paper.

[0033] The basis weight of the paper substrate is 120 g / m². ２ Preferably, it is 140 g / m² or more. ２ It is more preferable that the amount be greater than or equal to 160 g / m². ２ It is even more preferable that the above conditions are met. The basis weight of the paper substrate is 600 g / m². ２ Preferably, it is 500 g / m ２ It is more preferable that it be 450 g / m ２It is even more preferable that the base layer 2 is composed of multiple layers. If the base layer 2 is composed of multiple layers, the thickness of the base layer 2 means the total thickness of the multiple layers of base material. The same applies to the basis weight.

[0034] The surface roughness Ra on the thermoplastic adhesive resin layer side of the paper substrate is 2.0 μm or more, preferably 2.3 μm or more, and more preferably 2.5 μm or more. The surface roughness Ra on the thermoplastic adhesive resin layer side of the paper substrate is not particularly limited, but is preferably 50 μm or less, more preferably 30 μm or less, and even more preferably 10 μm or less. Adhesion to the thermoplastic adhesive resin layer can be improved by having a surface roughness Ra of 2.0 μm or more on the thermoplastic adhesive resin layer side of the paper substrate.

[0035] As described later, even when using a paper substrate having a predetermined basis weight and surface roughness Ra, laminating a barrier layer to the surface of the paper substrate via a thermoplastic adhesive resin layer containing polyethylene resin effectively suppresses the reduction in barrier properties due to stress and results in a barrier laminate with high RtoR stability.

[0036] In this specification, the terms "polyethylene-based resin," etc., are used to include not only "polyethylene resin" but also copolymers that contain, for example, 50% or more (preferably 70% or more, more preferably 80% or more) polyethylene main chains, and in which a portion of the main chains is replaced by other main chains different from polyethylene. The same applies to resins other than "polyethylene-based resins" as described later.

[0037] The thickness of the paper substrate is not particularly limited as long as the basis weight and surface roughness Ra are within a predetermined range, and is more preferably 10 μm to 1500 μm, more preferably 30 μm to 500 μm, and even more preferably 100 μm to 400 μm.

[0038] The air permeability (smoothness) of the paper substrate is not particularly limited as long as the basis weight and surface roughness Ra are within a predetermined range, but is preferably 60 sec or less, more preferably 50 sec or less, and even more preferably 40 sec or less, as measured by JIS 8119 (Bekka method).

[0039] The paper substrate may contain additives. Examples of additives include sizing agents, lubricants, antioxidants, UV absorbers, light stabilizers, antistatic agents, fluorescent whitening agents, fluorescent decolorizing agents, fillers, reinforcing agents, pigments, and dyes. Additives can be added in any amount as needed, as long as they do not adversely affect other properties.

[0040] The surface of the base layer 2 on the thermoplastic adhesive resin layer 3 side may be pre-treated with physical surface treatments such as corona discharge treatment, ozone treatment, plasma treatment, glow discharge treatment, and sandblasting, as well as chemical surface treatments such as oxidation treatment using chemicals.

[0041] Generally, since the surface of paper is porous and uneven, it is sometimes preferable to form a sealing layer of 20 μm or more on the surface of the paper when directly forming a barrier layer by depositing inorganic material onto the paper. However, in the present invention, since barrier paper can be manufactured by the transfer method described later, it is not necessary to directly form a barrier layer (inorganic vapor-deposited layer) on the paper. Therefore, it is not necessary to form such a thick sealing coat layer on the surface of the paper.

[0042] Furthermore, when forming a barrier layer (inorganic vapor deposition layer) by placing paper material in a vapor deposition apparatus and depositing inorganic material under reduced pressure, paper dust generated from the paper material can hinder the reduction of pressure inside the vapor deposition apparatus to a suitable atmospheric pressure for vapor deposition. In such cases, it is difficult to form a stable barrier layer (inorganic vapor deposition layer), which can easily result in insufficient adhesion between the formed barrier layer (inorganic vapor deposition layer) and the paper material, leading to unstable gas barrier properties. However, in this embodiment, since barrier paper can be manufactured by the transfer method described later, it is not necessary to place the paper material in the vapor deposition apparatus and directly form a barrier layer (inorganic vapor deposition layer) on the paper material. Therefore, the above-mentioned problems can be avoided.

[0043] Thus, in this embodiment, a paper substrate can be made of paper material and not impregnated with resin components, clay material, etc. Furthermore, in this embodiment, it is preferable that the paper substrate is made of paper material and does not have a sealing layer, a resin layer, or a clay coat layer, and that a thermoplastic adhesive resin layer is formed directly on the substrate layer (paper substrate).

[0044] The base material layer 2, such as a paper base material, may consist of a single layer, or it may consist of two or more layers made of the same or different base materials. The base materials may be laminated together by any lamination means, such as through conventionally known adhesive layers or thermoplastic adhesive resin layers.

[0045] With such thickness and / or basis weight, for example, appropriate strength and rigidity can be imparted to the barrier laminate 1. If the thickness and / or basis weight is above the lower limit, for example, curling and warping can be suppressed during the manufacturing of the barrier laminate 1. If the thickness and / or basis weight is below the upper limit, the strength and rigidity will be within an appropriate range, and a decrease in work efficiency can be suppressed.

[0046] <Printed layer 4> In one embodiment of the present invention, the barrier laminate 1 may have a printed layer 4 provided on the surface of the substrate layer 2, such as a paper substrate, that is opposite to the thermoplastic adhesive resin layer 3.

[0047] The printing layer 4 includes, for example, an image. Examples of images include letters, figures, symbols, pictures, patterns, and combinations thereof. The printing layer 4 is provided, for example, for indicating the contents of the packaging material, indicating the expiration date, indicating the manufacturer and seller, for decoration, and for adding an aesthetic appeal.

[0048] In one embodiment, the printed layer 4 is formed using a printing layer composition such as a thermoplastic resin composition, a thermosetting resin composition, and an active energy ray curable resin composition, each containing a colorant. Specifically, the printed layer 4 contains a thermoplastic resin, a cured product of a thermosetting resin, or a cured product of an active energy ray curable resin, and a colorant.

[0049] The thermoplastic resin composition contains a thermoplastic resin and a colorant. Examples of thermoplastic resins include polyolefin resins, vinyl resins, styrene resins, (meth)acrylic resins, polyester resins, polyurethane resins, polycarbonate resins, polyamide resins, polyimide resins, cellulose resins, petroleum resins, and fluororesins.

[0050] In this specification, the term (meth)acrylic resin is used to encompass both acrylic resins and methacrylic resins. The same applies to the term (meth)acrylate compound.

[0051] Thermoplastic resin compositions may contain additives. Examples of additives include lubricants, antioxidants, UV absorbers, light stabilizers, antistatic agents, fluorescent whitening agents, fluorescent decolorizing agents, fillers, reinforcing agents, pigments and dyes, dispersants, dispersing aids, and surfactants.

[0052] A thermosetting resin composition is a composition that contains a thermosetting resin, a colorant, and optionally a curing agent, and hardens upon heating. In one embodiment, the thermosetting resin composition is a so-called thermosetting ink.

[0053] Examples of thermosetting resins include phenolic resins, melamine resins, urea resins, epoxy resins, unsaturated polyesters, thermosetting polyurethanes, silicone resins, and (meth)acrylic thermosetting resins. Examples of curing agents include epoxy curing agents and isocyanate curing agents.

[0054] The thermosetting resin composition may contain the same additives as those contained in the thermoplastic resin composition described above.

[0055] The active energy ray curable resin composition is a composition that contains a compound having an active energy ray curable functional group (hereinafter also referred to as "active energy ray curable compound") and a colorant, and is cured by irradiation with active energy rays. In one embodiment, the active energy ray curable resin composition is a so-called ultraviolet curable ink, and preferably a (meth)acrylic ultraviolet curable ink.

[0056] Examples of colorants include pigments and dyes. Specific examples of pigments include titanium dioxide, zinc oxide, carbon black, iron oxide, iron yellow, ultramarine, metallic pigments, pearl pigments, and fluorescent pigments. The printed layer 4 may also be a high-luminosity layer having a high metallic luster.

[0057] Compositions for printing layers (thermoplastic resin compositions, thermosetting resin compositions, active energy ray curable resin compositions) may contain organic solvents and / or water from the viewpoint of improving coatability and other properties. Examples of organic solvents include hydrocarbon solvents such as toluene and xylene; ketone solvents such as acetone and methyl ethyl ketone; ester solvents such as ethyl acetate, cellosolve acetate and butyl cellosolve acetate; and alcohol solvents such as propanol.

[0058] For example, the printing layer composition may be applied to a substrate layer 2 such as a paper substrate and dried, and then, in the case of a thermosetting resin composition, it may be heated to the temperature required for curing, or in the case of an active energy ray curable resin composition, it may be irradiated with active energy rays to form the printing layer 4. If the printing layer composition does not contain organic solvents and / or water, drying is not necessary.

[0059] Methods for forming the printed layer 4 include, for example, letterpress printing, flexographic printing, gravure printing, offset printing, screen printing, inkjet printing, and thermal transfer printing. The printed layer may be applied to the entire surface of the substrate or to only a part of it.

[0060] In one embodiment, the printed layer 4 contains a sublimation dye. The printed layer 4 in this embodiment can be formed, for example, by sublimation transfer printing using a thermal transfer sheet.

[0061] The thickness of the printed layer 4 is preferably 0.01 μm or more and 30 μm or less, more preferably 0.01 μm or more and 10 μm or less, and even more preferably 0.01 μm or more and 5 μm or less.

[0062] <Thermoplastic Adhesive Resin Layer 3> The barrier laminate 1 of the present invention is characterized by having a thermoplastic adhesive resin layer 3 between the base layer 2 and the barrier layer 13. In the transfer method described later, the thermoplastic adhesive resin layer 3 is a layer for bonding a transfer object, such as a base layer 2 having a paper base, with a transfer film 30 (transfer layer 10, described later) having a support base 20, a heat seal layer 11, and a barrier layer 13.

[0063] In conventional barrier laminates using paper substrates, it was common practice to laminate the barrier layer to the surface of the paper substrate via an adhesive layer. However, when using paper substrates with high basis weight and high surface roughness, the adhesive layer could not adequately conform to the surface of the paper substrate, resulting in lamination with partial lifting between the paper substrate and the transfer film. Our research has revealed that this can cause the adhesive layer in the barrier laminate to peel off due to stress, reducing the barrier properties of the barrier laminate.

[0064] Furthermore, our research has revealed that when manufacturing barrier laminates using a paper substrate with a high basis weight and high surface roughness, if an intermediate laminate in which a release film (support substrate) is laminated to a heat seal layer is transported by roll-to-roll, wrinkles may occur in the laminate (intermediate laminate, barrier laminate) or the release film may not peel off cleanly during roll-to-roll transport or when peeling off the release film after roll-to-roll transport.

[0065] The adhesive layer formed using conventionally known adhesives is a one- or two-component curing adhesive. As such, the formed adhesive layer forms a polymer network structure, resulting in strong chemical bonds and limited freedom of movement between the paper substrate and the lower film (barrier layer). Therefore, as shown in Figure 6A, when stress is applied to the barrier laminate, the neutral plane between the upper film (paper substrate) and the lower film exists in the adhesive layer, while tensile stress is generated on the upper film (paper substrate) side of the adhesive layer, and compressive stress is generated on the lower film side of the adhesive layer.

[0066] Furthermore, when a paper substrate with a high basis weight and rough surface is used as the top film, the high strength and rigidity of the paper substrate means that when stress is applied to the barrier laminate, the tensile and compressive stresses on each surface of the adhesive (adhesive layer) increase, causing the adhesive layer in the barrier laminate to peel off.

[0067] In contrast, the barrier laminate of the present invention is characterized in that the barrier layer is laminated via a thermoplastic adhesive resin layer containing polyethylene resin instead of such an adhesive layer. Polyethylene resin has higher flexibility compared to adhesive layers that form a polymer network structure. Therefore, by laminating the barrier layer to the surface of the paper substrate via a thermoplastic adhesive resin layer containing polyethylene resin, a degree of freedom is created in the movement between the upper film (paper substrate) and the lower film (barrier layer). As shown in Figure 6B, when stress is applied to the barrier laminate, neutral surfaces exist on both the upper film (paper substrate) and the lower film. Tensile stress is generated on the surface of the upper film, and compressive stress is generated on the back surface (adhesive side) of the upper film, so the stress can be offset to some extent on both the front and back surfaces of the upper film. Also, tensile stress is generated on the surface (adhesive side) of the lower film, and compressive stress is generated on the back surface (opposite side of the adhesive), so the stress can also be offset to some extent on both the front and back surfaces of the lower film. Therefore, even if a paper substrate with a high basis weight and high surface roughness is used as the upper film, the compressive and tensile stresses on the upper and lower film surfaces of the adhesive (thermoplastic adhesive resin layer) are less likely to increase. Furthermore, since the thermoplastic adhesive resin layer is more flexible than the adhesive layer, the delamination of the barrier laminate by the thermoplastic adhesive resin layer can be effectively suppressed. In addition, even when the intermediate laminate before the release film (support substrate) is peeled off is transported by roll-to-roll, the peelability of the release film in the intermediate laminate after transport is reduced, and wrinkles in the barrier laminate when the release film is peeled off can be effectively suppressed.

[0068] Furthermore, a thermoplastic adhesive resin layer may be provided between the paper substrate and the barrier layer, and other layers such as a protective layer may also be provided, but it is preferable not to provide an adhesive layer.

[0069] Furthermore, the polyethylene resin is not particularly limited as long as it contains a predetermined amount or more of polyethylene main chain. For example, resins such as low-density polyethylene, ionomers, ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-methyl acrylate copolymer (EMA), ethylene-ethyl acrylate copolymer (EEA), and ethylene-methyl methacrylate copolymer (EMMA) can be used. Among these, ethylene-methyl methacrylate copolymer (EMMA) is preferred from the viewpoint of adhesion. By including such an acid-modified polyethylene resin, it becomes possible to more effectively cancel out stress between the surface on the lower film side of the adhesive layer and the other side.

[0070] The melt flow rate (MFR) of the thermoplastic adhesive resin layer at 190°C and a load of 2.16 kg, as measured according to JIS K7210, is preferably 3 g / 10 min or more and 30 g / 10 min or less, more preferably 5 g / 10 min or more and 25 g / 10 min or less, and even more preferably 7 g / 10 min or more and 20 g / 10 min or less. The melt flow rate (MFR) of the thermoplastic adhesive resin layer at 190°C and a load of 2.16 kg, as measured according to JIS K7210, is preferably 3 g / 10 min or more, more preferably 5 g / 10 min or more, and even more preferably 7 g / 10 min or more. The melt flow rate (MFR) of the thermoplastic adhesive resin layer at 190°C and a load of 2.16 kg, as measured according to JIS K7210, is preferably 30 g / 10 min or less, more preferably 25 g / 10 min or less, and even more preferably 20 g / 10 min or less.

[0071] The indentation hardness of the thermoplastic adhesive resin layer is preferably 45 MPa or less, preferably 40 MPa or less, and preferably 36 MPa or less. By keeping the indentation hardness of the thermoplastic adhesive resin layer within this range, the thermoplastic adhesive resin layer does not become too hard, and the reduction in the barrier properties of the barrier laminate due to stress can be suppressed.

[0072] Further, the complex elastic modulus of the thermoplastic adhesive resin layer is preferably 0.5 GPa or less, more preferably 0.3 GPa or less, and still more preferably 0.25 GPa or less. By the complex elastic modulus of the thermoplastic adhesive resin layer satisfying this range, the resistance to elastic deformation can be reduced, and it is possible to suppress the reduction of the barrier property of the barrier laminate due to stress.

[0073] The indentation hardness of the thermoplastic adhesive resin layer is calculated by the following formula (1). Further, the complex elastic modulus of the thermoplastic adhesive resin layer is calculated by the following formula (2). Indentation hardness = Pmax / A... (1)

[0074]

[0075] Here, Pmax: maximum load (unit: μN) A: contact projection area at maximum depth (unit: μm ２ ) S: contact rigidity.

[0076] The indentation hardness and complex elastic modulus of the thermoplastic adhesive resin layer are measured by the nanoindentation method from the cross-section of the thermoplastic adhesive resin layer of the barrier laminate. This method is a method capable of measuring the complex elastic modulus and indentation hardness of the thermoplastic adhesive resin layer without peeling the barrier laminate to expose the thermoplastic adhesive resin layer. The above cross-section is obtained by cutting in the thickness direction perpendicular to the main surface of the barrier laminate. The cross-section preparation was carried out by preparing a block in which the barrier laminate was embedded with an embedding resin and cutting the block at room temperature (23 ° C) using a commercially available rotary microtome. The finishing was carried out with a diamond knife.

[0077] The indentation hardness and composite modulus of the cross-section of a thermoplastic adhesive resin layer are measured using the nanoindentation method. First, an indenter is placed on the cross-section of the thermoplastic adhesive resin layer and pressed down to a load of 10 μN from the cross-section over 10 seconds, and held in that position for 5 seconds. The indenter is pressed into the area near the center in the thickness direction of the thermoplastic adhesive resin layer, where the cross-section is exposed. Then, the load is removed over 10 seconds. This yields the maximum load Pmax, the contact projected area A at the maximum depth, and the load-displacement curve. Unless otherwise specified, the measurements are performed in an environment of 50% relative humidity and 23°C. Measurements are performed at five or more locations on the same cross-section, and the indentation hardness and composite modulus are recorded as the arithmetic mean of the five values ​​measured with good reproducibility. Further detailed measurement conditions are described in the examples.

[0078] The composite modulus and indentation hardness of the thermoplastic adhesive layer can be adjusted, for example, by the composition of the thermoplastic adhesive layer or the drying temperature during the formation of the thermoplastic adhesive layer.

[0079] In one embodiment, the thermoplastic adhesive resin layer 3 may be a layer in contact with the barrier layer 13 or a protective layer 14 provided on the side of the barrier layer 13 opposite to the heat seal layer 11. In this embodiment, the thermoplastic adhesive resin layer 3 protects the barrier layer 13. For example, when a bending load is applied to the barrier laminate 1, the thermoplastic adhesive resin layer 3 suppresses the occurrence of cracks in the barrier layer 13, and even if minute cracks begin to appear in the barrier layer 13 after the bending load, it suppresses a decrease in gas barrier properties.

[0080] The thickness of the thermoplastic adhesive resin layer 3 is not particularly limited, but is preferably 0.5 μm to 100 μm, more preferably 3 μm to 70 μm. Even more preferably, it is 5 μm to 50 μm, and even more preferably, 5 μm to 30 μm. Having the thickness of the thermoplastic adhesive resin layer 3 within this range improves the adhesion between the paper substrate and the barrier layer.

[0081] The thermoplastic adhesive resin layer 3 can be formed using a conventionally known polyethylene-based resin. For example, a resin containing a polyethylene-based resin can be formed by an extrusion lamination method. The extrusion lamination method is a lamination method in which molten resin adheres to a substrate layer like an adhesive and is laminated.

[0082] Known manufacturing methods such as melt extrusion can be employed. Melt extrusion methods include the T-die method, which extrudes from a T-type die to form a sheet, and the inflation method, which uses a ring-shaped circular die to extrude and simultaneously blow air to form a tubular film. However, the T-die method is preferred because it offers high accuracy in sheet thickness. Alternatively, an anchor coat layer may be formed first on the layer on which the thermoplastic adhesive resin layer 3 is formed, before the thermoplastic adhesive resin layer 3 is formed. In addition, instead of the anchor coat layer, ozone treatment or corona treatment may be applied to the layer on which the thermoplastic adhesive resin layer 3 is formed (for example, the surface of the protective layer or the surface of the paper substrate).

[0083] <Heat seal layer 11> In one embodiment, the barrier laminate 1 (1A) of the present invention includes a heat seal layer 11. The heat seal layer 11 functions as a heat sealable sealant layer when the barrier laminate 1 is used as a packaging material, for example. The heat seal layer 11 also functions as a release layer from the support substrate 20 that constitutes the transfer film 30 described later when the barrier laminate 1 such as barrier paper is manufactured by the transfer method described later.

[0084] The heat seal layer 11 is a layer having heat sealability, specifically a layer that can be bonded to an object by heating and pressing, or a layer that can be bonded by fusing heat seal layers together by heating and pressing. It should be noted that there is no prejudice to using the transfer film 30 of the present invention for applications that do not require heat sealing.

[0085] Heat sealing layers at 120°C for 0.1 seconds, 1 kgf / cm². ２ The sealing strength at this pressure is preferably 1.8 N / 15 mm width or more, and more preferably 2.0 N / 15 mm width or more. Furthermore, the heat sealing strength between the heat sealing layers is 120°C × 0.1 seconds, 1 kgf / cm². ２The upper limit of the seal strength at the given pressure is not particularly limited, but it is preferably 20 N / 15 mm width or less.

[0086] In one embodiment, the heat seal layer 11 is formed by applying a heat seal coating liquid to the barrier layer or heat seal layer, and then drying the heat seal coating liquid. Examples of heat seal coating liquids include aqueous heat seal coating liquids containing water. It is preferable that the aqueous heat seal coating liquid is applied to the barrier layer or heat seal layer in a state where a heat-sealable resin or the like is dispersed in water (dispersion, suspension, or emulsion).

[0087] The resin component of the coating liquid for the heat seal layer can be, for example, a thermoplastic resin. Examples of thermoplastic resins include olefin resins and (meth)acrylic resins. Among these, (meth)acrylic resins are preferred. By including a (meth)acrylic resin, blocking of the resulting heat seal layer can be effectively suppressed.

[0088] As the olefin resin, polyethylene resins are preferred, such as high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene and ultra-low-density polyethylene, ethylene-vinyl acetate copolymer resin, ethylene (meth)acrylic copolymer resin, ethylene-vinyl chloride copolymer resin, ethylene-vinyl acetate-vinyl chloride copolymer resin, and ethylene-vinyl acetate-acrylic copolymer resin. From the viewpoint of reducing environmental impact, biomass-derived polyethylene and / or recycled polyethylene may be used. The ethylene-vinyl acetate copolymer resin may contain other polymerization components such as acrylic acid esters or acrylic acid.

[0089] As the acrylic resin, for example, one obtained by addition polymerization of one or more acrylic monomers selected from acrylic acid, methacrylic acid, acrylic acid esters, and methacrylic acid esters can be used. The acrylic monomer may be a comonomer having functional groups such as hydroxyl groups, epoxy groups, and amino groups in its molecular structure. The acrylic resin may also be an ionomer.

[0090] Furthermore, as will be described later, when manufactured by a transfer method, it is preferable to form the heat seal layer using a heat seal layer coating solution containing a thermoplastic ionomer. Ionomers are a general term for synthetic resins in which polymers are aggregated using the cohesive force of metal ions.

[0091] Examples of the above-mentioned metal ions include alkali metal ions and alkaline earth metal ions, specifically sodium, potassium, calcium, magnesium, and zinc.

[0092] A heat-seal layer is typically an unstretched layer. For example, a heat-seal layer can be formed by applying and drying a coating agent containing a thermoplastic resin onto a support substrate, or by melt-extruding a resin composition containing an olefin polymer onto a support substrate.

[0093] Examples of solvents for the heat seal layer coating liquid include water; alcohol solvents such as methanol, ethanol, 2-propanol, and 1-butanol; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; glycol solvents such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether acetate, and propylene glycol monomethyl ether acetate; ester solvents such as methyl acetate, ethyl acetate, and butyl acetate; hydrocarbon solvents such as n-hexane, cyclohexane, benzene, toluene, and xylene; halogenated hydrocarbon solvents such as methylene chloride and chloroform; ether solvents such as dioxolane and tetrahydrofuran; nitrogen-containing solvents such as acetonitrile and N,N-dimethylformamide; and sulfur-containing solvents such as dimethyl sulfoxide.

[0094] For the preparation of the coating solution for the heat seal layer, it is preferable to use an ionomer emulsion, more preferable to use a self-emulsifying emulsion, and even more preferable to use a self-emulsifying emulsion of a metal salt of an ethylene-(meth)acrylic acid copolymer.

[0095] It is preferable to use an aqueous ionomer emulsion as the emulsion described above. Such emulsions allow for relatively low control of the coating amount and, since there are no VOE emissions, it is possible to obtain packaging materials with a low environmental impact.

[0096] The thickness of the heat seal layer is not particularly limited, but is preferably 1 μm to 15 μm, more preferably 2 μm to 10 μm, and even more preferably 3 μm to 5 μm. The thickness of the heat seal layer may be appropriately changed depending on the strength of the heat seal layer, the processability of the transfer film, and the mass of the contents filled into the packaging material manufactured using the barrier laminate. The heat seal layer may be composed of multiple heat seal layers.

[0097] <Anchor Coat Layer 12> In one embodiment, the barrier laminate 1 (1A) of the present invention may further include an anchor coat layer 12 between the heat seal layer 11 and the barrier layer 13. By providing the anchor coat layer 12, the adhesion between the heat seal layer 11 and the barrier layer 13 can be improved, and the occurrence of delamination between these layers can be suppressed. The anchor coat layer 12 is in contact with the barrier layer 13 on one side and in contact with the heat seal layer 11 on the other side.

[0098] In one embodiment, the anchor coat layer 12 contains a resin component. Examples of the resin component include thermoplastic resins such as polyolefin resins (e.g., polyethylene resins and polypropylene resins), vinyl resins, styrene resins, (meth)acrylic resins, polyester resins, polyurethane resins, and polyamide resins; and cured products of thermosetting resins such as phenolic resins, melamine resins, epoxy resins, alkyd resins, thermosetting (meth)acrylic resins, unsaturated polyester resins, and thermosetting polyurethane resins. When using a thermosetting resin, it is preferable to use a curing agent such as an amine compound, a phenolic compound, an isocyanate compound, and a carboxylic acid compound in combination.

[0099] As for the resin component, polyester resins are preferred, for example, from the viewpoint of adhesion. Examples of polyester resins include polymers synthesized by polycondensation of acid components such as polycarboxylic acids, their esters and acid anhydrides with polyhydric alcohols, lactone ring-opening polymers, polyhydroxycarboxylic acid polymers, urea-modified polyesters, and urethane-modified polyesters. Urethane-modified polyester is a polyester having urethane bonds.

[0100] The thickness of the anchor coat layer is preferably 0.01 μm to 10 μm, more preferably 0.05 μm to 5 μm, and even more preferably 0.1 μm to 3 μm. If the thickness is above the lower limit, for example, sufficient adhesion strength can be obtained between the heat seal layer and the barrier layer. If the thickness is below the upper limit, for example, the anchor coat layer can be formed well on the heat seal layer.

[0101] <Barrier Layer 13> The barrier laminate 1 (1A) of the present invention comprises a barrier layer 13. Preferably, the barrier layer 13 is a layer directly formed on one side of the heat seal layer 11, or, if an anchor coat layer 12 is provided, on one side of the anchor coat layer 12.

[0102] The barrier layer 13 is a layer that suppresses the permeation of gases such as oxygen gas and water vapor. Therefore, for example, the barrier laminate 1 obtained by transferring the transfer layer 10 from the transfer film 30 (described later) to the object to be transferred has excellent gas barrier properties. If the barrier layer 13 is an opaque layer, the barrier layer 13 may also have light-shielding properties against sunlight and fragrance-retaining properties for the contents.

[0103] The barrier layer 13 may be, for example, a metal vapor-deposited film formed by depositing a metal, or a vapor-deposited film formed by depositing an inorganic compound. In this specification, a layer formed by depositing such an inorganic material is referred to as an inorganic vapor-deposited layer.

[0104] Examples of metals that can constitute the metal vapor deposition layer include aluminum, chromium, tin, nickel, copper, silver, gold, and platinum. Among these, aluminum is preferred. In other words, an aluminum vapor deposition film is preferred.

[0105] Examples of inorganic compounds constituting the above-mentioned deposited film include metal oxides such as aluminum oxide and silicon oxide, metal nitrides and metal carbides, indium tin oxide (ITO), and SiO Ｘ C Ｙ Examples of complex inorganic compounds include those listed above. Among these, metal oxides are preferred.

[0106] Examples of metallic elements that make up inorganic compounds include aluminum (Al), silicon (Si), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti), lead (Pb), zirconium (Zr), yttrium (Y), zinc (Zn), vanadium (V), barium (Ba), and chromium (Cr).

[0107] The average composition of inorganic compounds is, for example, AlO ｘ SiO ｘ SiO ｘ C ｙ For example, MO ｘ or MO ｘ C ｙIt is expressed as follows: In the formula, M represents the metal element mentioned above, and the values ​​of x and y differ in range depending on the metal element.

[0108] Among metal oxides, aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, boron oxide, titanium oxide, zirconium oxide, and barium oxide are preferred, with aluminum oxide and silicon oxide being more preferred.

[0109] The inorganic vapor deposition layer may be formed from one metal or inorganic compound, or from a combination of two or more metals or inorganic compounds. The inorganic vapor deposition layer may consist of a single layer, or it may consist of two or more layers of the same or different compositions. Furthermore, the inorganic vapor deposition layer may be combined with the organic coating layer described later.

[0110] When the inorganic vapor deposition layer is multilayered, each layer can be deposited to have high gas barrier properties, thus achieving even higher gas barrier properties than a single layer. Furthermore, if the composition of each layer is different in a multilayered inorganic vapor deposition layer, the inorganic vapor deposition layer becomes a discontinuous layer, allowing for more efficient suppression of the permeation of oxygen gas and water vapor.

[0111] When an inorganic vapor-deposited layer is laminated as the barrier layer 13, the thickness of the inorganic vapor-deposited layer is preferably 3 nm to 300 nm, more preferably 4 nm to 250 nm, and even more preferably 5 nm to 200 nm. If the thickness is above the lower limit, for example, sufficient oxygen barrier properties and water vapor barrier properties can be obtained. If the thickness is below the upper limit, for example, the occurrence of cracks in the inorganic vapor-deposited layer can be suppressed.

[0112] Furthermore, the barrier layer 13 may be an organic coating layer formed by applying a coating agent containing a water-soluble polymer such as polyvinyl alcohol. The organic coating layer is formed, for example, by applying a coating solution containing a water-soluble polymer and at least one of one of a metal alkoxide and its hydrolysate, or tin chloride, or an aqueous solution or water / alcohol mixed solution. These may be formed on the inorganic vapor-deposited layer described above.

[0113] The organic coating layer preferably contains at least one component selected from the group consisting of hydroxyl group-containing polymer compounds, metal alkoxides, metal alkoxide hydrolysates, and metal alkoxide polymers. Examples of water-soluble polymers used in the organic coating layer include polyvinyl alcohol, polyvinylpyrrolidone, and starch, but the barrier properties of the organic coating layer are best when polyvinyl alcohol is used.

[0114] Examples of metal alkoxides include tetramethoxysilane (Si(OCH) ３ ) ４ ), tetraethoxysilane (Si(OC ２ H ５ ) ４ ), tetrapropoxysilane (Si(OC ３ H ７ ) ４ ) and tetrabutoxysilane (Si(OC ４ H ９ ) ４ ) are some examples.

[0115] It is preferable to use a silane coupling agent together with the above-mentioned metal alkoxide. As the silane coupling agent, known organic reactive group-containing organoalkoxysilanes can be used, and organoalkoxysilanes having an epoxy group are preferred. Examples of organoalkoxysilanes having an epoxy group include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. It is preferable to use the silane coupling agent in an amount of 1 to 20 parts by mass per 100 parts by mass of the metal alkoxide.

[0116] Preferred water-soluble polymers are polyvinyl alcohol and ethylene-vinyl alcohol copolymer. Depending on the desired physical properties such as oxygen barrier properties, water vapor barrier properties, water resistance, and weather resistance, either polyvinyl alcohol or ethylene-vinyl alcohol copolymer may be used, or both may be used in combination. Alternatively, a gas barrier coating film obtained using polyvinyl alcohol and a gas barrier coating film obtained using ethylene-vinyl alcohol copolymer may be laminated.

[0117] When an organic coating layer is laminated as the barrier layer 13, the thickness is preferably 3 nm to 300 nm, more preferably 4 nm to 250 nm, and even more preferably 5 nm to 200 nm. If the thickness is above the lower limit, for example, sufficient oxygen barrier properties and water vapor barrier properties can be obtained. If the thickness is below the upper limit, for example, the occurrence of cracks in the inorganic vapor-deposited layer can be suppressed.

[0118] <Protective layer 14> The barrier laminate 1 (1A) of the present invention may further include a protective layer 14 on the surface of the barrier layer 13 opposite to the surface facing the heat seal layer 11. This can, for example, suppress damage to the barrier layer 13.

[0119] In one embodiment, the protective layer 14 contains a resin component. Examples of resin components include polyethylene resins, polypropylene resins, polystyrene resins, vinyl chloride resins, polyester resins, (meth)acrylic resins, urethane resins, melamine resins, and epoxy resins. For example, urethane resin is preferred as the resin component.

[0120] The thickness of the protective layer 14 is preferably 0.01 μm or more and 5 μm or less, more preferably 0.05 μm or more and 3 μm or less, and even more preferably 0.1 μm or more and 1 μm or less.

[0121] For example, if the barrier layer 13 is an inorganic vapor-deposited layer composed of metal oxides such as aluminum oxide and silicon oxide, the transfer film may include a barrier coat layer as a protective layer 14 on the barrier layer. This can, for example, further improve the gas barrier properties of the barrier laminate.

[0122] In one embodiment, the barrier coating layer contains a gas barrier resin. Examples of gas barrier resins include ethylene-vinyl alcohol copolymer, polyvinyl alcohol, poly(meth)acrylonitrile; polyamides such as nylon 6, nylon 6,6 and polymethaxylylene adipamide (MXD6); polyester; polyurethane; and (meth)acrylic resin.

[0123] In another embodiment, the barrier coat layer is a gas barrier coating film formed by polycondensation treatment of a composition containing a metal alkoxide and a water-soluble polymer using a sol-gel method in the presence of a sol-gel catalyst, water, and an organic solvent. By providing such a barrier coat layer on an inorganic vapor-deposited layer, the gas barrier properties can be improved.

[0124] As the composition for forming such a barrier coating layer, the same type of coating liquid used for forming the organic coating layer described above can be used.

[0125] The thickness of the gas barrier coating film is preferably 0.01 μm to 100 μm, more preferably 0.1 μm to 50 μm. This further improves the gas barrier properties of the barrier laminate. If the thickness is above the lower limit, for example, the gas barrier properties of the barrier laminate can be further improved, and the occurrence of cracks in the inorganic vapor-deposited layer can be suppressed. If the thickness is below the upper limit, for example, a barrier laminate suitable for use in the manufacture of monomaterial packaging containers can be obtained.

[0126] <Applications of Barrier Laminate 1 (1A)> Compared to gas barrier plastic films, the barrier paper (barrier laminate 1) of this embodiment has a paper base material, resulting in a high paper content and a low plastic content. This contributes to reducing plastic waste, facilitates recycling and biodegradation, does not damage incinerators, and reduces incineration residue.

[0127] The oxygen permeability of the barrier laminate 1 such as barrier paper in this embodiment is not particularly limited, but is 10 cc / m². ２ Preferably, the pressure is 24hr / atm or less, and 5cc / m２ More preferably 24hr / atm or less, and 3cc / m ２ A pressure of 24hr / atm or less is more preferable, and 1.5cc / m³ is even more preferable. ２ A value of 24hr / atm or less is particularly preferred. The lower limit of oxygen permeability is, for example, 0.01 cc / m³. ２ Oxygen permeability may be measured at 24hr / atm. Oxygen permeability is measured in accordance with JIS K7126 under conditions of 23°C and 90% RH.

[0128] The water vapor permeability of the barrier laminate 1, such as barrier paper, in this embodiment is not particularly limited, but is 20 g / m². ２ Preferably 24hr or less, and 10 g / m ２ More preferably 24hr or less, and 5g / m ２ A rate of 24hr or less is more preferable, and 1.5 g / m² is even more preferable. ２ A value of 24hr or less is particularly preferred. The lower limit of water vapor transmission is, for example, 0.01 g / m³. ２ / 24hr is also acceptable. Water vapor transmission rate is measured in accordance with JIS K7129 under conditions of 40°C and 90% RH.

[0129] In one embodiment, the barrier laminate 1 of the present invention can be suitably used as a packaging material such as a packaging bag. As described above, the barrier laminate of this embodiment has excellent interlayer adhesion and suppresses delamination, so the packaging material equipped with the barrier laminate has suppressed so-called delamination during use.

[0130] In one embodiment, the packaging material of the present invention comprises the barrier laminate 1 described above. The packaging material of the present invention may further comprise, if necessary, layers having various functions together with the barrier laminate 1.

[0131] For example, a packaging material can be manufactured by folding the barrier laminate 1 in half so that the base material layer 2, such as a paper substrate, is on the outside and the heat-seal layer 11 is on the inside, overlapping the two halves, and then heat-sealing the edges. Alternatively, a packaging material can be manufactured by overlapping multiple barrier laminates 1 so that the heat-seal layers 11 face each other, and then heat-sealing the edges. The entire packaging material may be composed of the barrier laminate 1, or only a portion of the packaging material may be composed of the barrier laminate.

[0132] Examples of heat sealing forms for packaging materials include side seals, two-side seals, three-side seals, four-side seals, envelope seals, gusset seals (pillow seals), pleated seals, flat-bottom seals, square-bottom seals, and gusset seals. Stand-up pouches are also possible. Examples of heat sealing methods include bar seals, rotary roll seals, belt seals, impulse seals, high-frequency seals, and ultrasonic seals.

[0133] Examples of contents to be filled into the packaging material include liquids, powders, and gels, and may be food or non-food items. After filling the packaging material with contents, the opening of the packaging material is heat-sealed to obtain the package.

[0134] The contents specifically include coffee beans, tea leaves; cheese, snacks, rice crackers, fresh and semi-fresh confectionery, nuts, vegetables, fruits, fish and meat products, processed fish products, dried fish, smoked foods, preserved foods, raw rice, cooked rice dishes, mochi, baby food, jam, mayonnaise, ketchup, cooking oil, dressings, sauces, spices, dairy products, and pet food; beverages such as beer, wine, fruit juice, green tea, and coffee; pharmaceuticals; cosmetics, shampoo, conditioner, and detergents; and metal and electronic components.

[0135] <<Method for Manufacturing Barrier Laminate 1>> The barrier laminate 1 of the present invention can be obtained, for example, by the transfer method described below. The method for manufacturing the barrier laminate 1 by the above transfer method comprises: a step of preparing a transfer subject such as a paper member having a paper substrate and the transfer film 30 of the present invention (details will be described later) (hereinafter also referred to as the "preparation step"); a step of bonding the transfer subject and the transfer film 30 via a thermoplastic adhesive resin layer 3 such that the support substrate 20 of the transfer film 30 faces outward and the barrier layer 13 faces inward (towards the transfer subject) to obtain an intermediate laminate (hereinafter also referred to as the "bonding step"); and a step of peeling the support substrate 20 from the heat seal layer 11 of the intermediate laminate (hereinafter also referred to as the "peeling step").

[0136] Through the above-described bonding and peeling processes, a transfer layer 10 comprising a barrier layer 13 and a heat seal layer 11 in that order in the thickness direction can be transferred onto a transfer target including a base material layer 2 such as a paper member. The barrier layer 13 transferred onto the base material layer 2 by the transfer method results in less contamination, higher adhesion between the barrier layer 13 and the thermoplastic adhesive resin layer 3, greater homogeneity and stability, and superior gas barrier properties compared to a barrier layer directly formed on the paper substrate.

[0137] The manufacturing method according to this embodiment allows for the provision of a barrier layer 13 on a paper substrate, similar to the case where a resin substrate is used, thereby enabling the production of environmentally friendly barrier paper with excellent gas barrier properties.

[0138] Furthermore, in a method in which a barrier layer is formed on a paper substrate and a heat-seal layer is formed by applying a heat-seal coating liquid to the barrier layer, the gas barrier properties of the barrier layer may decrease due to cracks or thermal damage to the barrier layer caused by tension or drying during the formation of the heat-seal layer. The manufacturing method according to this embodiment can avoid such a decrease. In addition, the heat-seal layer 11 can suppress deterioration of the barrier layer during the application process and during the peeling process when the support substrate is peeled off.

[0139] In the manufacturing method according to this embodiment, the deterioration of the barrier layer can be suppressed, and therefore, for example, when a barrier laminate is used as a packaging material, the degree of deterioration due to bending, folding, and heat seal damage can be reduced.

[0140] It should be noted that a reference barrier paper (hereinafter also referred to as "reference barrier paper") with a different layer structure from the barrier paper according to this embodiment may also be considered, having a layer structure of paper base material / thermoplastic adhesive resin layer / barrier layer / release layer / primer layer / heat seal layer as needed.

[0141] One example of a method for manufacturing the reference barrier paper is to laminate a paper substrate and a transfer film comprising a transfer substrate, a release layer, and a barrier layer via a thermoplastic adhesive resin layer to form a laminate (1) having a layer structure of paper substrate / thermoplastic adhesive resin layer / barrier layer / release layer / transfer substrate; peel off the transfer substrate from the laminate (1) to form a laminate (2) having a layer structure of paper substrate / thermoplastic adhesive resin layer / barrier layer / release layer; and optionally form a primer layer and a heat seal layer on the release layer of the laminate (2) to obtain the reference barrier paper. Hereinafter, this manufacturing method will also be referred to as the "reference transfer method".

[0142] The reference transfer method has several advantages over barrier layers directly formed on paper substrates: the barrier layer transferred by the transfer method is less contaminated, has better adhesion between the barrier layer and the thermoplastic adhesive resin layer, is more homogeneous and stable, and has superior gas barrier properties.

[0143] However, since the reference barrier paper has a release layer between the heat seal layer and the barrier layer, the adhesion strength between these layers may not be sufficient. In addition, in the reference transfer method, after peeling off the transfer substrate, it is necessary to separately form a heat seal layer (heat sealable sealant layer) on the release layer, for example, when manufacturing packaging materials, which increases the number of manufacturing steps.

[0144] In contrast, the barrier paper according to this embodiment does not have a release layer between the heat seal layer 11 and the barrier layer 13, so the adhesion strength between these layers is sufficiently high. Furthermore, in the manufacturing method according to this embodiment, the heat seal layer 11 also serves as a release layer from the support substrate 20, and there is no need to separately form a heat seal layer (heat sealable sealant layer) after peeling off the support substrate 20, thus reducing the number of manufacturing steps.

[0145] Furthermore, in the manufacturing method according to this embodiment, in one embodiment, the heat seal layer 11 and the barrier layer 13 are pre-formed on the thin film support substrate 20. In the manufacturing of the transfer film 30, processing is possible in a wider and longer form than with a paper substrate, thus reducing the cost per unit area of ​​the barrier paper.

[0146] Thus, while both the reference barrier paper and the reference transfer method have excellent advantages, the barrier paper and its manufacturing method according to this embodiment are even superior in the points mentioned above and can be said to produce advantageous effects.

[0147] <Preparation Process> In the preparation process, the object to be transferred, such as a paper material including the base material layer 2, and the transfer film 30 are prepared.

[0148] The paper component comprises a paper base material. The paper component may be a single sheet or a continuous sheet wound into a roll.

[0149] The paper member may consist only of a paper substrate, or it may consist of a paper substrate and a printed layer 4 provided on the paper substrate. Preferably, the printed layer is provided on the side of the paper substrate opposite to the side on which the thermoplastic adhesive resin layer 3 is provided. In the preparation step, the paper member may be manufactured by forming the printed layer 4 on the paper substrate, or a paper member with the printed layer 4 already provided on the substrate layer 2 may be used. The printed layer may be formed between the bonding step and the peeling step, or after the peeling step, but from the viewpoint of suppressing a decrease in gas barrier properties, it is preferable to form the printed layer 4 before the bonding step.

[0150] The paper substrate may consist only of paper material, or it may consist of paper material and a sealing layer or resin layer formed on the paper material.

[0151] Furthermore, in addition to forming the printed layer 4 described above, the paper substrate may be decorated on the side opposite to the side on which the thermoplastic adhesive resin layer 3 is provided, for example, by foil stamping, embossing, and shaping. The paper member obtained in this way may be used. Decoration may be performed between the bonding process and the peeling process, or after the peeling process, but from the viewpoint of suppressing a decrease in gas barrier properties, it is preferable to perform the decoration before the bonding process.

[0152] Details of each element are as described above and will be omitted here. As the transfer target, the resin film described above may be used as the support substrate 20. Other substrates that are difficult to directly vapor-deposit (for example, wood) may also be used. In the preparation step, the transfer film according to this embodiment, which has been manufactured in advance, is prepared.

[0153] <Bonding Process> In the bonding process, a thermoplastic adhesive resin layer is formed by melt-extruding a thermoplastic resin containing polyethylene resin onto a base layer (paper base material) or a transfer film, and an intermediate laminate is obtained by bonding the layers via this thermoplastic adhesive resin layer. By providing a thermoplastic adhesive resin layer 3 between the base layer 2 and the barrier layer 13 (protective layer 14), even when a paper base material with a large surface roughness is used, the decrease in barrier properties due to stress can be effectively suppressed, and a barrier laminate with high RtoR stability can be obtained.

[0154] In the bonding process, the thermoplastic adhesive resin layer 3 may be formed on either the transfer object or the transfer film 30, or on both. In one embodiment, in the bonding process, the thermoplastic adhesive resin layer 3 is formed on the transfer object, and the transfer film is bonded to the thermoplastic adhesive resin layer 3.

[0155] In the bonding process, in one embodiment, a thermoplastic adhesive resin layer 3 is formed on the transfer film, and the transfer object (paper substrate) is bonded to the thermoplastic adhesive resin layer 3. The thermoplastic adhesive resin layer 3 is formed on the surface of the transfer film 30 opposite to the support substrate 20. In one embodiment, it is preferable to form the thermoplastic adhesive resin layer 3 on the barrier layer 13 of the transfer film 30.

[0156] When forming a thermoplastic adhesive resin layer 3 on a base layer (paper base material), it is preferable to form the thermoplastic adhesive resin layer 3 directly on the base layer (paper base material).

[0157] In the bonding process, in one embodiment, a thermoplastic adhesive resin layer 3 may be formed on the transfer object (paper substrate), a thermoplastic adhesive resin layer 3 may be formed on the transfer film 30, and the transfer object and the transfer film 30 may be bonded together so that their respective thermoplastic adhesive resin layers 3 are in contact.

[0158] As for the specific method of forming the thermoplastic adhesive resin layer 3, known manufacturing methods such as melt extrusion methods such as the extrusion lamination method (EC method) and the co-extrusion lamination method can be employed. Melt extrusion methods include the T-die method, in which the material is extruded from a T-type die to form a sheet, and the inflation method, in which a ring-shaped circular die is used to form a tubular film by extruding and simultaneously blowing air. However, the T-die method is preferred because it offers high accuracy in sheet thickness.

[0159] Prior to forming the thermoplastic adhesive resin layer 3, an anchor coat layer may be formed before forming the thermoplastic adhesive resin layer 3 to improve its adhesion. The anchor coat agent is preferably formed by coating and drying. Alternatively, instead of the anchor coat layer, ozone treatment or corona treatment may be applied to the layer on which the thermoplastic adhesive resin layer 3 is formed.

[0160] The bonding process can be carried out using generally known equipment, temperature, and pressure, depending on the type and characteristics of the thermoplastic adhesive resin and the method of forming the thermoplastic adhesive resin layer 3. For example, a thermoplastic resin containing polyethylene resin is put into a melt extruder and extruded under a predetermined pressure to form a sheet.

[0161] <Peeling Process> In the peeling process, the support substrate 20 is peeled from the heat seal layer 11 of the intermediate laminate. For example, after bonding between the object to be transferred and the transfer film by the thermoplastic adhesive resin layer 3, the support substrate 20 is peeled from the intermediate laminate. Peeling can be performed using known equipment and temperatures depending on the type and characteristics of the thermoplastic adhesive resin layer 3.

[0162] In one embodiment, the support substrate 20 of the transfer film 30 may be peeled off while the transfer object and the transfer film 30 are bonded together via the thermoplastic adhesive resin layer 3. In this way, a barrier laminate 1 such as barrier paper according to this embodiment can be obtained.

[0163] For example, if the intermediate laminate is a continuous sheet wound in a roll shape, a release roll may be used to continuously peel the support substrate 20 from the heat seal layer 11 of the intermediate laminate, and the barrier laminate 1 and the support substrate 20 may be wound up separately.

[0164] <<Other Embodiments of the Barrier Laminate>> Figure 2 is a laminate configuration diagram showing another example of the layer configuration of the barrier laminate 1 (1B). In the description of the barrier laminate 1B shown in Figure 2, the same reference numerals are used for components equivalent to those in the barrier laminate 1A shown in Figure 1, and redundant explanations are omitted. The barrier laminate 1B shown in Figure 2 differs from the barrier laminate 1A shown in Figure 1 in that a surface heat seal layer 5 is provided on the printed layer 4 of the barrier laminate 1A shown in Figure 1.

[0165] When the barrier laminate 1B is used as a packaging material, and the heat seal layer 11 is placed on the inside to wrap the object to be packaged, the heat seal layer 11 and the surface heat seal layer 5 can be joined at the edges of the packaging material (see Figure 5B).

[0166] <<Layer Structure of Transfer Film 30>> Figure 3 is a laminated diagram showing an example of the layer structure of the transfer film. The transfer film 30 according to this embodiment comprises a support base material 20, a heat seal layer 11, and a barrier layer 13 in this order in the thickness direction. The transfer film 30 may further include an anchor coat layer 12 between the heat seal layer 11 and the barrier layer 13. The transfer film 30 may also further include a protective layer 14 on the side of the barrier layer 13 opposite to the heat seal layer 11.

[0167] Of the layers of the transfer film 30, the layers excluding the support substrate 20, namely the heat seal layer 11, anchor coat layer 12, barrier layer 13, and protective layer 14, constitute the transfer layer 10. That is, the transfer film 30 of this embodiment comprises a support substrate 20 and a transfer layer 10 provided on the support substrate 20, and the transfer layer 10 comprises the heat seal layer 11 and the barrier layer 13 in this order in the thickness direction. In one embodiment, the transfer layer 10 may further include an anchor coat layer 12 between the heat seal layer 11 and the barrier layer 13. The transfer layer 10 may also further include a protective layer 14 on the side of the barrier layer 13 opposite to the heat seal layer 11. The heat seal layer 11 is in contact with the support substrate 20 and is provided so as to be peelable from the support substrate 20.

[0168] In this case, in the transfer layer 10, the barrier layer 13 and the heat seal layer 11 (or the anchor coat layer 12 if an anchor coat layer 12 is provided) are in contact, or the transfer layer 10 does not have a release layer between the barrier layer 13 and the heat seal layer 11.

[0169] In one embodiment, the transfer film 30 includes a protective layer 14 on the barrier layer 13. In one embodiment, if the barrier layer 13 is an inorganic vapor-deposited layer composed of metal oxides such as aluminum oxide and silicon oxide, the transfer film 30 may include an organic coating layer formed by applying a coating agent containing a water-soluble polymer such as polyvinyl alcohol on the barrier layer 13. The support substrate 20 as the transfer substrate, and therefore the transfer film 30, may be a single-sheet film or a continuous film wound in a roll.

[0170] <Support Substrate 20> The transfer film 30 according to this embodiment includes a support substrate 20 as a transfer substrate. The support substrate 20 is preferably a film made of resin (hereinafter also referred to as "resin film"). Examples of the resin include polyester resins such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT); polyamide resins such as various nylons, especially aromatic polyamides such as nylon MXD6; vinyl resins such as ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer and polyvinyl alcohol; polyolefin resins such as polyethylene resin, polypropylene resin, polybutene resin and cyclic polyolefin; styrene resins such as styrene homopolymer, acrylonitrile-styrene copolymer (AS resin), and acrylonitrile-butadiene-styrene copolymer (ABS resin); (meth)acrylic resin, polycarbonate, polyimide resin, diarylphthalate resin, silicone resin, polysulfone resin, polyphenylene sulfide resin, polyethersulfone resin, polyurethane resin, cellulose resin, and fluorine resin.

[0171] The resin film may consist of a single layer, or it may consist of two or more layers of the same or different compositions. The resin film may be an unstretched film, or a stretched film such as a uniaxially oriented film or a biaxially oriented film.

[0172] The thickness of the support substrate 20 is preferably 5 μm to 200 μm, more preferably 8 μm to 100 μm, and even more preferably 10 μm to 80 μm.

[0173] The support substrate 20 preferably has the property of being able to form a heat seal layer 11 on the substrate and being able to be easily peeled off the substrate from the heat seal layer 11 in the peeling process. From this viewpoint, among resin films, films containing polyester resins and films containing polyamide resins are preferred, films containing polyester resins are more preferred, and films containing polyethylene terephthalate are even more preferred.

[0174] The support substrate 20 has excellent mechanical, physical, and chemical properties that can withstand the barrier layer formation process 13, and it is particularly preferable that it has strength and heat resistance. Polyethylene terephthalate film is also preferable from this viewpoint.

[0175] Preferably, the resin film does not have a known easy-adhesion treatment applied to the surface in contact with the heat-seal layer 11, and it is also preferable that the surface in contact with the heat-seal layer 11 does not have a known easy-adhesion layer. With such a configuration, for example, the peelability between the support substrate 20 and the heat-seal layer 11 in the peeling process can be improved.

[0176] Furthermore, the surface of the support substrate 20 that contacts the heat seal layer 11 may be provided with a fine uneven surface to achieve a predetermined surface roughness (for example, Ra of 0.5 μm or more and 10 μm or less). This allows the fine uneven surface corresponding to the fine uneven surface of the support substrate 20 to be transferred and formed on the exposed surface of the heat seal layer 11 on the sealing side, making it possible to achieve a desired surface roughness on the exposed surface of the heat seal layer 11 on the sealing side.

[0177] <Heat seal layer 11> The transfer film 30 according to this embodiment includes a heat seal layer 11 as a surface layer on one side. In one embodiment, the heat seal layer 11 functions as a heat seal layer. For example, when the barrier laminate 1 is used as a packaging material, the heat seal layer 11 functions as a heat sealable sealant layer. The heat seal layer also functions as a release layer from the support substrate 20 when the barrier laminate is manufactured by the transfer method described above. Details of the heat seal layer 11 are as described above and will not be explained further in this section.

[0178] <Anchor Coat Layer 12> The transfer film 30 according to this embodiment may further include an anchor coat layer 12 between the heat seal layer 11 and the barrier layer 13. By providing the anchor coat layer 12, the adhesion between the heat seal layer 11 and the barrier layer 13 can be improved, and the occurrence of delamination between these layers can be suppressed. The anchor coat layer 12 is, for example, in contact with the barrier layer 13 on one side and in contact with the heat seal layer 11 on the other side. Details of the anchor coat layer 12 are as described above and will not be explained further in this section.

[0179] <Barrier Layer 13> The transfer film 30 according to this embodiment includes a barrier layer 13. Preferably, the barrier layer 13 is a layer directly formed on one side of the heat seal layer 11, or on one side of the anchor coat layer 12 if an anchor coat layer 12 is provided. Details of the barrier layer 13 are as described above and will not be explained further in this section.

[0180] <Protective Layer 14> The transfer film 30 of the present invention may be provided with a protective layer 14 on the surface of the barrier layer 13 opposite to the surface facing the heat seal layer 11. This can, for example, suppress damage to the barrier layer 13. Details of the protective layer 14 are as described above and will not be explained further in this section.

[0181] [Method for manufacturing the transfer film 30] The method for manufacturing the transfer film 30 of the present invention may include the steps of forming a heat seal layer 11 on a support substrate 20 (hereinafter also referred to as the "heat seal layer formation step"), forming an anchor coat layer 12 on the heat seal layer 11 as needed (hereinafter also referred to as the "anchor coat layer formation step"), and forming a barrier layer 13 on the heat seal layer 11 or the anchor coat layer 12 (hereinafter also referred to as the "barrier layer formation step"). The above manufacturing method may also include the step of forming a protective layer 14 on the barrier layer 13 (hereinafter also referred to as the "protective layer formation step").

[0182] <Heat seal layer formation process> The heat seal layer 11 can be formed, for example, by applying a heat seal layer coating liquid to one surface of the support substrate 20 and drying it. It is preferable to provide the heat seal layer 11 on a surface of the support substrate 20 that has not been treated for easy adhesion, or on a surface where an easy adhesion layer has not been formed.

[0183] As the coating liquid for the heat seal layer, it is preferable to have a coating liquid that can form a coating film on the support substrate 20 and that can form a coating film that has excellent peelability from the support substrate 20 as well as heat sealability. Details of the coating liquid for the heat seal layer are as described above.

[0184] In one embodiment, a coating liquid for the heat seal layer is applied to the support substrate 20 and dried. Examples of known coating methods for the heat seal layer coating liquid include gravure coating, reverse coating, air knife coating, comma coating, die coating, blade coating, roll coating, bar coating, curtain coating, spray coating, lip coating, and dipping.

[0185] Methods for drying the applied heat-seal coating liquid include, for example, hot air drying, hot roll drying, and methods involving the application of heat such as infrared irradiation. The drying temperature is preferably 50°C to 150°C.

[0186] Furthermore, if the heat seal layer 11 has a two-layer structure, the first heat seal layer coating liquid is applied to the support substrate 20 and dried to form the first heat seal layer, and then the second heat seal layer coating liquid is applied to the first heat seal layer and dried to form the second heat seal layer. The same applies even if the heat seal layer 11 has a three-layer or more structure.

[0187] <Anchor Coat Layer Formation Process> The anchor coat layer 12 can be formed, for example, by applying an anchor coat coating liquid to the surface of the heat seal layer 11 and drying it. By providing the anchor coat layer 12 on the heat seal layer 11, the adhesion of the barrier layer 13 can be improved and the surface of the barrier layer can be smoothed. Depending on the required degree of gas barrier properties and the required interlayer strength, the anchor coat layer 12 may not be provided.

[0188] An anchor coating agent for forming an anchor coating layer can be prepared, for example, by mixing the above-mentioned resin component or its precursor resin (e.g., thermosetting resin), a curing agent as needed, an additive as needed, and a solvent. Details of these components are as described above, and the solvent can be the same as the solvent used for the coating liquid for the heat seal layer.

[0189] The anchor coat layer 12 can be formed, for example, by applying an anchor coat coating liquid onto the heat seal layer 11 and drying it. The known application methods described above are examples of how to apply the anchor coat coating liquid. Methods for drying the applied anchor coat coating liquid include, for example, applying heat such as hot air drying, hot roll drying, and infrared irradiation. The drying temperature is preferably 50°C to 150°C.

[0190] <Barrier Layer Formation Process> The barrier layer 13 can be formed, for example, by depositing an inorganic substance onto the surface of the anchor coat layer 12, or by applying a coating agent and drying it. Preferably, the barrier layer 13 is a layer formed directly on one side of the heat seal layer 11 or the anchor coat layer 12. Details of the barrier layer 13 are as described above and will not be explained further in this section.

[0191] When stacking inorganic vapor-deposited layers formed by depositing inorganic materials as a barrier layer, examples of methods for forming the inorganic vapor-deposited layers include physical vapor deposition (PVD) methods such as vacuum deposition, sputtering, ion plating, and cluster ion beam deposition, as well as chemical vapor deposition (CVD) methods such as plasma chemical vapor deposition, thermochemical vapor deposition, and photochemical vapor deposition. The inorganic vapor-deposited film may also be a composite film comprising two or more different layers formed by using both physical vapor deposition and chemical vapor deposition methods in combination. Examples of heating means include resistance heating, induction heating, and electron beam heating.

[0192] The gas pressure in the deposition chamber is 10 －８ mbar or higher 10 －２ A pressure of 10 mbar or less is preferred. When forming a barrier layer 13 composed of an inorganic compound, for example, oxygen gas, nitrogen gas, or carbon dioxide gas is introduced as the reaction gas. When forming a barrier layer 13 composed of a metal oxide, the gas pressure after the introduction of oxygen gas is 10 mbar or less. －６ mbar or higher 10 －１ A value of mbar or less is preferable.

[0193] The amount of reaction gas introduced varies depending on the size of the deposition machine, etc. Inert gases such as argon, helium, and nitrogen may be used as carrier gases for the reaction gases, such as oxygen, to the extent that it does not cause problems.

[0194] When a roll-shaped transfer substrate is used and an inorganic vapor deposition layer is formed continuously, the transport speed of the transfer substrate on which the heat seal layer 11 and, if necessary, the anchor coat layer 12 are formed is, for example, 10 m / min or more and 800 m / min or less.

[0195] During the formation of the inorganic vapor deposition layer, Ar gas and O ２ or N ２By pretreatment using such methods, the surface of the layer on which the inorganic vapor deposition layer is formed can be cleaned, and polar groups or free radicals can be generated on the surface of the layer, thereby increasing the adhesion between the inorganic vapor deposition layer and the layer.

[0196] In one embodiment, the PVD method uses, for example, a winding type deposition machine, where a substrate unwound from an unwinding roll is placed in a deposition chamber, where a deposition source heated in a crucible is evaporated, and an inorganic deposition layer is formed on the substrate on a cooled coating drum while oxygen gas or the like is blown out from an oxygen gas outlet as needed, and then the substrate is wound onto a winding roll.

[0197] In one embodiment, the PE-CVD method involves, for example, introducing a mixed gas containing, for instance, an organosilicon compound as a monomer gas, oxygen gas, and an inert gas into a deposition chamber, and generating a plasma to form an inorganic deposition layer composed of silicon oxide or the like on a substrate.

[0198] When laminating an organic coating layer formed by applying a coating agent containing a water-soluble polymer as a barrier layer, the coating agent (composition) for forming the organic coating layer can be prepared, for example, by mixing a water-soluble polymer with an aqueous solution or water / alcohol mixture containing at least one of one of the following: one or more metal alkoxides and hydrolysates, or tin chloride.

[0199] First, a metal alkoxide, a water-soluble polymer, a sol-gel catalyst, water, an organic solvent, and optionally a silane coupling agent are mixed to prepare a composition. A polycondensation reaction gradually proceeds within this composition.

[0200] Next, the composition is applied to the anchor coat layer 12 using the known application method described above and dried. This drying further promotes the polycondensation reaction between the metal alkoxide and the water-soluble polymer (and the silane coupling agent if the composition contains one), forming a composite polymer layer.

[0201] Next, the composition is heated, preferably at a temperature of 20°C to 250°C, more preferably at 50°C to 220°C, for a period of 1 second to 10 minutes. This allows an organic coating layer to be formed.

[0202] The above-mentioned substrate comprises a transfer substrate, a heat seal layer 11, and optionally an anchor coat layer 12. In this way, a transfer film is obtained having the transfer substrate, the heat seal layer 11, optionally an anchor coat layer 12, and a barrier layer 13 in this order in the thickness direction.

[0203] <Protective Layer Formation Process> The protective layer 14 can be formed, for example, by applying a protective layer coating liquid onto the barrier layer 13 and drying it. The known application method for the protective layer coating liquid is the one described above. The drying method for the applied protective layer coating liquid is, for example, a method of applying heat such as hot air drying, hot roll drying, and infrared irradiation. The drying temperature is preferably 50°C to 150°C.

[0204] The protective layer coating liquid can be prepared, for example, by mixing the resin components described above with a curing agent as needed, an additive as needed, and a solvent. The details of these components are as described above, and the solvent can be the same as the solvent used for the heat seal layer coating liquid.

[0205] The barrier coat layer, which serves as the protective layer 14, can be formed, for example, by dissolving or dispersing a material such as a gas barrier resin in water or a suitable organic solvent, and then applying and drying the resulting coating solution onto the inorganic vapor-deposited layer. The barrier coat layer can also be formed, for example, by applying and drying a commercially available barrier coat agent.

[0206] In one embodiment, the barrier coating layer is the gas barrier coating film described above. The gas barrier coating film can be formed, for example, in the same manner as the organic coating layer described above.

[0207] <<Packaging 100 using barrier laminate 1A>> Next, we will describe packaging 100 in which the contents P are packaged using the barrier laminate 1A (see Figure 1) described above.

[0208] Figures 4A and 4B show one embodiment of a packaging body formed using a barrier laminate. Figure 4A is a perspective view of the packaging body formed using a barrier laminate, and Figure 4B is a cross-section of Figure 4A along the line b-b.

[0209] As shown in Figures 4A and 4B, the packaging body 100 comprises an upper surface 101, a lower surface 102, a right side surface 103, a left side surface 104, a front side surface 105, and a rear side surface 106, and is a rectangular parallelepiped-shaped packaging body in which a rectangular parallelepiped-shaped contents P is packaged by a rectangular barrier laminate 1A.

[0210] The heat-seal layers 11 of the rectangular barrier laminate 1A face each other and are heat-sealed to enclose the side surfaces of the rectangular parallelepiped contents P, thereby forming the top surface 101, bottom surface 102, right side surface 103, and left side surface 104 of the packaging body 100.

[0211] Here, the edges of the barrier laminate 1A that are substantially parallel to the side surface of the contents P are heat-sealed by facing each other with the heat-seal layers 11 of one edge and the other edge, i.e., the inner surfaces of the barrier laminate 1A, as shown in Figure 4B, and a seal portion 110 is formed on the upper surface 101. In addition, the edges of the barrier laminate 1A that are substantially perpendicular to the side surface of the contents P are folded and sealed as appropriate to form the front surface 105 and the rear surface 106. The seal portion 110 may be joined to the upper surface 101 if necessary.

[0212] <<Packaging 200 using barrier laminate 1B>> Next, we will describe packaging 200 in which the contents P are sealed using the barrier laminate 1B (see Figure 2) described above.

[0213] Figures 5A and 5B show one embodiment of a packaging body formed using a barrier laminate. Figure 5A is a perspective view of the packaging body formed using a barrier laminate, and Figure 5B is a cross-section of Figure 5A along the line b-b.

[0214] As shown in Figures 5A and 5B, the packaging body 200 comprises an upper surface 201, a lower surface 202, a right side surface 203, a left side surface 204, a front side surface 205, and a rear side surface 206, and is a rectangular parallelepiped-shaped packaging body in which a rectangular parallelepiped-shaped contents P is sealed and packaged by a rectangular barrier laminate 1C.

[0215] As shown in Figures 5A and 5B, the heat-seal layer 11 of the rectangular barrier laminate 1C becomes the inner surface and the surface heat-seal layer 5 becomes the outer surface, and by enclosing the side circumferential surface of the rectangular parallelepiped contents P, the top surface 101, bottom surface 102, right side surface 103, and left side surface 104 of the packaging body 100 are formed.

[0216] Here, the edges of the barrier laminate 1A that are substantially parallel to the side surface of the contents P are overlapped and heat-sealed, as shown in Figure 5B, so that the heat-seal layer 11 of one edge and the surface heat-seal layer 5 of the other edge face each other, and a seal portion 210 is formed on the upper surface 201. In addition, the edges of the barrier laminate 1A that are substantially perpendicular to the side surface of the contents P are folded and sealed as appropriate to form the front side surface 205 and the rear side surface 206.

[0217] The present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way to these descriptions.

[0218] [Example 1: Preparation of Transfer Film] A heat seal layer coating liquid 1 described below was applied to the non-corona-treated surface of a PET film (manufactured by Toyobo Co., Ltd., 12 μm thick, one-sided corona-treated product, corresponding to the support substrate 20 in Figure 3) by gravure coating and dried to form a heat seal layer with a thickness of 5 μm (corresponding to the heat seal layer 11 in Figure 3).

[0219] Next, a coating liquid for the anchor coat layer was prepared by mixing polyester (manufactured by Toyobo Co., Ltd., trade name: Byron® UR1700) as the main agent, XDI-based isocyanate (manufactured by Mitsui Chemicals, Inc., trade name: Takenate D110N) as the curing agent, and nitrocellulose as an additive, in a ratio of main agent:curing agent:nitrocellulose (solid content mass ratio) of 1:1:1. Then, the coating liquid for the anchor coat layer was applied to the heat seal layer 11 by gravure coating and dried to form an anchor coat layer with a thickness of 700 nm (corresponding to the anchor coat layer 12 in Figure 3).

[0220] Then, a silica vapor-deposited film with a thickness of 45 nm (corresponding to the barrier layer 13 in Figure 3) was formed on the anchor coat layer corresponding to the anchor coat layer 12 in Figure 3 by physical vapor deposition.

[0221] A protective coating solution containing urethane resin and a silane coupling agent was applied to the silica vapor-deposited film corresponding to the barrier layer 13 in Figure 3 by gravure coating and dried to form a protective layer with a thickness of 200 nm (corresponding to the protective layer 14 in Figure 3). In this way, a transfer film having a layer structure of PET film (supporting substrate) / heat seal layer / anchor coat layer / silica vapor-deposited film (barrier layer) / protective layer was obtained.

[0222] [Example 1: Fabrication of a barrier laminate] A polyethylene resin (ethylene-methyl methacrylate copolymer (product name: Nucrel AN4228C, manufactured by Mitsui Dow Polychemicals, MFR: 14 g / 10 min)) was melt-extruded at a temperature of 285°C directly below the T-die using an extruder equipped with a T-die. The original die roll, film formation speed, and nip pressure were adjusted to create a 15 μm thick layer on top of the protective layer of the transfer film. Simultaneously, the thermoplastic adhesive resin layer surface of the transfer film and the paper substrate (manufactured by Smurfit Westrock, Diamond-Top, paper basis weight: 161 g / m²) were combined. ２A rough surface with Ra: 2.8 μm and Beck smoothness (JIS P8119 (ISO5627)): 19.4 seconds) was placed opposite a paper substrate, and the two were bonded together using a roll-to-roll method and pressed to perform sand lamination, thereby forming a thermoplastic adhesive resin layer between the paper substrate and the protective layer. Subsequently, aging was performed at 25°C for 4 hours to obtain the intermediate laminate of Example 1 having a layer structure of paper substrate / thermoplastic adhesive resin layer / protective layer / silica vapor-deposited film (barrier layer) / anchor coat layer / heat seal layer / PET film (support substrate). After that, the PET film (support substrate) in the intermediate laminate was peeled off to obtain the barrier laminate of Example 1.

[0223] [Example 2] The intermediate laminate and barrier laminate of Example 2 were manufactured in the same manner as the barrier laminate of Example 1, except that the thickness of the thermoplastic adhesive resin layer was changed to 5 μm.

[0224] [Example 3] In forming the thermoplastic adhesive resin layer, low-density polyethylene (LDPE (product name: LDPE-955, manufactured by Hanwha Chemical, melting point: 105°C, MFR: 7.7 g / 10 min)) was melt-extruded at 315°C using an extruder equipped with a T-die, and the original die roll, film formation speed, and nip pressure were adjusted to form a thermoplastic adhesive resin layer with a thickness of 5 μm on the protective layer of the transfer film. The intermediate laminate and barrier laminate of Example 3 were manufactured in the same manner as the barrier laminate of Example 1 described above.

[0225] [Example 4] In forming the thermoplastic adhesive resin layer, low-density polyethylene (LDPE (product name: Novatec LC520, manufactured by Nippon Polyethylene Co., Ltd., melting point: 111°C, MFR: 3.6 g / 10 min)) was melt-extruded at 315°C using an extruder equipped with a T-die, and the original die roll, film formation speed, and nip pressure were adjusted to form a thermoplastic adhesive resin layer with a thickness of 15 μm on the protective layer of the transfer film. The intermediate laminate and barrier laminate of Example 4 were manufactured in the same manner as the barrier laminate of Example 1 described above.

[0226] [Comparative Example 1] A barrier laminate of Comparative Example 1 was manufactured in the same manner as the barrier laminate of Example 1, except that an adhesive layer was formed instead of a thermoplastic adhesive resin layer. Specifically, an adhesive (manufactured by Rock Paint Co., Ltd., adhesive for dry lamination, main component RU-004: curing agent H-1 = 15:2 mass ratio) was applied to the protective layer surface of the transfer film and dried to form an adhesive layer with a thickness of 10 μm. The intermediate laminate and barrier laminate of Comparative Example 1 were manufactured in the same manner as the barrier laminate of Example 1, except that an adhesive (manufactured by Rock Paint Co., Ltd., adhesive for dry lamination, main component RU-004: curing agent H-1 = 15:2 mass ratio) was applied and dried to form an adhesive layer with a thickness of 10 μm.

[0227] [Comparative Example 2] The intermediate laminate and barrier laminate of Comparative Example 2 were manufactured in the same manner as the barrier laminate of Comparative Example 1, except that the thickness of the adhesive layer was changed to 5 μm.

[0228] [Comparative Example 3] In the production of the barrier paper of Comparative Example 1, the adhesive used to form the adhesive layer was changed to adhesive PZ-907 (manufactured by Saiden Chemical Co., Ltd., wet lamination adhesive), and an adhesive layer with a thickness of 5 μm was formed. Other than this, the intermediate laminate and barrier laminate of Comparative Example 3 were produced in the same manner as the barrier laminate of Comparative Example 1.

[0229] [Comparative Example 4] A barrier laminate of Comparative Example 4 was manufactured without forming a thermoplastic adhesive resin layer. Specifically, a paper substrate (Smurfit Westrock, Diamond-Top, basis weight: 161 g / m²) was used. ２ A protective layer coating solution containing urethane resin and silane coupling agent was applied to a rough surface with Ra: 2.8 μm and Beck smoothness (JIS P8119 (ISO5627)): 19.4 seconds by gravure coating and dried to form a protective layer with a thickness of 750 nm. A silica vapor-deposited film (barrier layer) with a thickness of 45 nm was formed on the protective layer as an inorganic vapor-deposited film by physical vapor phase growth. An anchor coat layer coating solution was applied to the barrier layer by gravure coating and dried to form an anchor coat layer with a thickness of 700 nm. A heat seal layer coating solution was applied to the heat seal layer by gravure coating and dried to form a heat seal layer with a thickness of 5 μm. A PET film was then bonded to the heat seal layer to produce the intermediate laminate of Comparative Example 4.

[0230] [Comparative Example 5] The intermediate laminate and barrier laminate of Comparative Example 5 were manufactured in the same manner as the barrier laminate of Example 1, except that the clay-coated surface (Ra: 0.3 μm, Beck smoothness (JIS P8119 (ISO 5627)): 76.7 seconds) of the paper substrate of the barrier paper in Example 1 was opposed to the thermoplastic adhesive resin layer surface of the transfer film, and the two were bonded together using a roll-to-roll method and pressed to perform sand lamination.

[0231] [Comparative Example 6] Paper substrate: Daio Paper Corporation, Sarakiryuou 50g / m² ２ The intermediate laminate and barrier laminate of Comparative Example 6 were manufactured in the same manner as the barrier laminate of Example 1, except that the Ra value was changed to 1.3 μm.

[0232] [Comparative Example 7] In the production of the barrier paper of Comparative Example 1, the adhesive used to form the adhesive layer was changed to Chemipearl (registered trademark) S120 (Mitsui Chemicals, Inc., aqueous ionomer emulsion, composition: metal salt of ethylene-methacrylic acid copolymer, self-emulsifying emulsion), and an adhesive layer with a thickness of 15 μm was formed. Except for these differences, the intermediate laminate and barrier laminate of Comparative Example 7 were produced in the same manner as the barrier laminate of Comparative Example 1.

[0233] [measurement]

[0234] (Measurement of composite modulus and indentation hardness of adhesive resin layer) The composite modulus (GPa) and indentation hardness (MPa) of the adhesive resin layer in the barrier laminates of the examples and comparative examples were measured under the following conditions. The results are shown in Table 1. Measuring device: HISITRON TI-950 Triboindenter Measurement location: From the cross-sectional side of the adhesive resin layer Measurement mode: Indentation Indenter: cubecorner indenter, TI-0037 Measurement profile 0→10 sec: 0→10 μN 10→15 sec: 10 μN 15→25 sec: 10→0 μN

[0235] (RtoR Stability) The RtoR stability (roll-to-roll stability) of the barrier laminates of the examples and comparative examples was evaluated. Specifically, in the manufacturing of the intermediate laminates of the examples and comparative examples before peeling of the PET film (support substrate), the occurrence of wrinkles during sand lamination and when peeling of the release film, as well as the peelability of the PET film (support substrate) after sand lamination were evaluated. (Evaluation Criteria) A: The intermediate laminate could be transported without wrinkles or peeling at the paper / adhesive interface. B: Wrinkles occurred in the laminate during sand lamination or when peeling of the PET film (support substrate), or the PET film (support substrate) could not be peeled off cleanly.

[0236] (Adhesion) The adhesion of the barrier laminates of the examples and comparative examples was evaluated. Specifically, the adhesion between the transfer layer and the thermoplastic adhesive resin layer (or adhesive layer) of the barrier laminates of the examples and comparative examples was measured using a Tensilon tensile testing machine (RTC-1310A, manufactured by Orientec Co., Ltd.) at a peeling speed of 300 mm / min. The adhesion was measured immediately after manufacturing and 4 days after the manufacturing of the barrier laminates.

[0237] (Barrier Properties) The barrier properties (oxygen permeability and water vapor permeability) of the barrier laminates of the examples and comparative examples were evaluated. Oxygen permeability was measured using MOCON's OXTRAN, and water vapor permeability was measured using MOCON's PERMATRAN, and evaluated according to the following evaluation criteria. (Evaluation Criteria) ・Oxygen permeability A: 0.5 cc / m ２ Less than 24hr / atm B: 0.5cc / m ２ Water vapor transmission rate A: 0.5 g / m² (24hr / atm or higher) ２ / Less than 24hr B: 0.5g / m ２ / 24 hours or more

[0238] (Barrier properties after creasing) For the barrier laminates of the examples and comparative examples, creasing was performed in a cross shape with a creasing width of 13 mm by punching with a creasing punching machine, and then the barrier properties (oxygen permeability and water vapor permeability) were evaluated according to the following evaluation criteria. (Evaluation criteria) ・Oxygen permeability A: 2 cc / m ２Less than 24hr / atm B: 2cc / m ２ Water vapor transmission rate A: 2 g / m³ (24hr / atm or higher) ２ / Less than 24hr B: 2g / m ２ / 24 hours or more

[0239] (Barrier properties after folding (2 folds)) The barrier properties (oxygen permeability and water vapor permeability) of the barrier laminates of the examples and comparative examples were evaluated after folding (2 folds). Specifically, the barrier laminates of the examples and comparative examples were creased in a cross shape by die-cutting with a creasing and die-cutting machine. Next, the barrier laminate was folded in half along one of the two creasing lines, with the base layer (paper base material) facing outwards, using a roller (diameter: φ95, material: rubber (hardness: 80±5Hs)) to apply a pressure of 2 kg. The folded barrier laminate was then opened and folded in half again along the other creasing line, with the base layer (paper base material) facing outwards, using the same roller to apply a pressure of 2 kg. Then, the folded barrier laminate was opened and the barrier properties (oxygen permeability and water vapor permeability) were measured and evaluated according to the following evaluation criteria. (Evaluation criteria) ・Oxygen permeability A: 5 cc / m ２ Less than 24hr / atm B: 5cc / m ２ Water vapor permeability of 24hr / atm or higher, or when wrinkles occur. A: 5g / m ２ / Less than 24hr B: 5g / m ２ / 24 hours or more, or when wrinkles appear

[0240] (Repulpability) The repulpability of the barrier laminates of the examples and comparative examples was evaluated. Specifically, the barrier laminates of the examples and comparative examples were cut into 25 mm x 25 mm pieces to make test pieces. The weight of the test pieces was measured immediately before the test, and the test pieces were placed in the container of a pulp dissociator (manufactured by Kumagai Riki Kogyo Co., Ltd., conforming to JIS P8220:2012). Then, 2 L of water was added using a graduated cylinder, and the dissociation treatment was performed by stirring at a rotation speed of 3000 rpm for 10 minutes. After that, a sorting treatment was performed using a sorting treatment device (manufactured by Kumagai Riki Kogyo Co., Ltd., No. 2625) with a flat screen (6 cuts, slit width 0.15 mm), by placing the pulp slurry into the liquid input section on the flat screen and sorting treatment was performed in a water flow of 10 L / min. The pulp collected on the sieve and the residue remaining on the screen were collected. The pulp was dewatered by pressing a spatula against it, and then placed together with the residue on aluminum foil that had been weighed beforehand. It was dried in an oven (105°C), and after being partially dried, it was dried at 85°C for two days. After being left at room temperature for one day, the weight was measured, and the percentage of weight before and after the test was determined.

[0241] The main components of the barrier laminates for each example and comparative example, along with their respective evaluation results, are summarized in Table 1 below.

[0242]

[0243] As can be seen from the table above, Examples 1 to 4 all received an "A" rating for RtoR stability (roll-to-roll stability), and furthermore, their barrier properties after creasing and after folding (two folds) also received an "A" rating. From this, it was confirmed that the barrier laminates of Examples 1 to 4, by laminating the barrier layer on the surface of the paper substrate via a thermoplastic adhesive resin layer containing polyethylene resin, can effectively suppress the decrease in barrier properties due to stress, even when using paper substrates with high surface roughness, and also exhibit high RtoR stability. In addition, it was confirmed that in all Examples 1 to 4, the indication hardness of the thermoplastic adhesive resin layer was 45 MPa or less, and the thermoplastic adhesive resin layer did not become too hard, thus suppressing the decrease in barrier properties of the barrier laminate due to stress. Furthermore, it was confirmed that in all Examples 1 to 4, the composite elastic modulus of the thermoplastic adhesive resin layer was 0.5 GPa or less, which reduces the resistance to elastic deformation, thus suppressing the decrease in barrier properties of the barrier laminate due to stress.

[0244] On the other hand, Comparative Examples 1 and 2, in which the adhesive layer was formed using a dry laminating adhesive instead of a thermoplastic adhesive resin layer, received a "B" rating for RtoR stability (roll-to-roll stability), indicating that the objectives of the present invention were not achieved. Furthermore, Comparative Example 2, in which a 5 μm thick adhesive layer was formed using a dry laminating adhesive; Comparative Example 3, in which the adhesive layer was formed using a wet laminating adhesive instead of a thermoplastic adhesive resin layer; Comparative Example 4, in which the barrier layer was directly deposited without laminating a thermoplastic adhesive resin layer; Comparative Example 5, in which the adhesive resin layer was formed on the clay-coated surface of a paper substrate; and Comparative Example 7, in which the adhesive layer was formed using a wet laminating adhesive instead of a thermoplastic adhesive resin layer, all received a "B" rating for barrier properties after stress was applied (folding) (barrier properties after creasing and barrier properties after folding (twice)), indicating that the barrier properties deteriorated under stress, and thus the objectives of the present invention were not achieved. In Comparative Example 6, similar to the above-described examples, the RtoR stability (roll-to-roll stability) was rated "A," and furthermore, the barrier properties before and after creasing and after folding (two folds) were also rated "A." However, because the basis weight of the paper substrate was significantly lower than that of each example, the surface roughness of the paper substrate was also relatively lower, and it did not satisfy the requirement that the surface roughness Ra of the paper substrate be 2 μm or more as defined in the present invention.

[0245] 1: Barrier laminate 2: Substrate layer (paper substrate) 3: Thermoplastic adhesive resin layer 4: Printing layer 5: Surface heat seal layer (second heat seal layer) 10: Transfer layer 11: Heat seal layer 12: Anchor coat layer 13: Barrier layer 14: Protective layer 20: Support substrate 30: Transfer film 100, 200: Packaging 110, 210: Seal portion

Claims

Paper substrate and A thermoplastic adhesive resin layer, Barrier layer, Heat seal layer and They are provided in this order, A barrier laminate wherein the surface roughness Ra on the thermoplastic adhesive resin layer side of the paper substrate is 2.0 μm or more, The thermoplastic adhesive resin layer includes a polyethylene-based resin. Barrier laminate. 　 The barrier laminate according to claim 1, wherein the melt flow rate (MFR) of the thermoplastic adhesive resin layer at 190°C and a load of 2.16 kg, as measured according to JIS K7210, is 3 g / 10 min or more and 30 g / 10 min or less. 　 The barrier laminate according to claim 1, wherein the polyethylene resin is an acid-modified polyethylene resin. 　 The barrier laminate according to claim 1, wherein the air permeability of the paper substrate is 60 sec or less as measured by JIS 8119 (Bekk method). 　 The barrier laminate according to claim 1, wherein the indentation hardness of the thermoplastic adhesive resin layer is 45 MPa or less. 　 The barrier laminate according to claim 1, wherein the composite elastic modulus of the thermoplastic adhesive resin layer is 0.5 GPa or less. 　 The basis weight of the aforementioned paper substrate is 120 g / m². ２ The barrier laminate according to claim 1. 　 A packaging body in which the contents are packaged using a barrier laminate according to any one of claims 1 to 7, A packaging body in which the contents are sealed by heat sealing the heat-seal layers facing each other at least a portion of the peripheral edge of the barrier laminate. 　 A packaging body in which the contents are packaged using a barrier laminate according to any one of claims 1 to 7, A second heat seal layer, identical or different from the heat seal layer, is laminated on the paper substrate of the barrier laminate. A packaging body in which the contents are sealed by overlapping and heat-sealing the heat-seal layer and the second heat-seal layer at least a portion of the peripheral edge of the barrier laminate. 　 Paper substrate and A thermoplastic adhesive resin layer, Barrier layer, Heat seal layer and They are provided in this order, A method for manufacturing a barrier laminate wherein the surface roughness Ra on the thermoplastic adhesive resin layer side of the paper substrate is 2.0 μm or more, The process includes forming the thermoplastic adhesive resin layer by melt-extruding a thermoplastic resin containing a polyethylene resin, A method for manufacturing a barrier laminate.

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