Laminate and laminate manufacturing method

Abstract

To provide a laminate having barrier property while being mono-material, a package and a laminate manufacturing method.SOLUTION: There is provided a laminate in which a base material layer and a barrier coat layer are laminated, in which the base material layer contains a polyolefin resin as a formation material. It is preferable for the laminate that a base material layer, a printing layer, an anchor coat layer and a barrier coat layer be laminated in this order. A method for manufacturing a laminate in which a base material layer, a printing layer and a barrier coat layer are laminated includes the steps of: using the base material layer containing a polyolefin resin as a formation material, and forming a printing layer on the base material layer using printing means; and printing a barrier coat agent on the printing layer by the printing means, and forming a barrier coat layer, and continuously performs the steps of forming the printing layer and forming the barrier coat layer by the printing means.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a laminate and a method for producing the laminate. [Background technology]

[0002] Stand-up pouches are widely used as refill packaging for shampoo, conditioner, etc. In general, standing pouches have a bottom film disposed between a pair of body films. The bottom film and body film are made of laminated films having a base layer and a sealant layer.

[0003] Patent Documents 1 and 2 describe laminate films that have been conventionally used for packaging, in which a polyolefin resin such as low-density polyethylene, linear low-density polyethylene, ethylene-vinyl acetate copolymer, or polypropylene is laminated as a sealant layer on a base film such as biaxially oriented polypropylene, biaxially oriented polyamide, or biaxially oriented polyester. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-265020 A [Patent Document 2] JP 2013-39932 A Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, there has been a problem with the recovery of plastic containers and packaging after use, in that packaging that contains two or more types of resin is difficult to recycle as plastic containers and packaging. To facilitate recycling, mono-material containers and packaging that use a single resin have been proposed. As a single resin, polyethylene resin is inexpensive and easy to process, but it has problems with poor barrier properties and being easily permeated by low molecular weight components such as fragrances. Here, "barrier properties" refers to the ability to block gases, moisture, gases, odors, light, etc.

[0006] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a laminate that is a monomaterial and has barrier properties, and a method for producing the laminate. [Means for solving the problem]

[0007] That is, the present invention employs the following configuration. [1] A laminate comprising at least a substrate layer, a printing layer, and a barrier coat layer, the substrate layer being made of a polyolefin resin. [2] The laminate according to [1], further comprising an anchor coat layer. [3] The laminate according to [2], in which a substrate layer, a printing layer, an anchor coat layer, and a barrier coat layer are laminated in this order. [4] The laminate according to [2], further comprising a solid print layer. [5] The laminate according to [4], in which a base layer, a printing layer, an anchor coat layer, a barrier coat layer, and a solid printing layer are laminated in this order. [6] The laminate according to [1], wherein the barrier coat layer is pattern-printed. [7] The laminate according to [1] or [2], further comprising a sealant layer. [8] A method for manufacturing a laminate in which a base layer, a printed layer, and a barrier coat layer are stacked, the base layer being made of a polyolefin resin, the method comprising the steps of forming a printed layer on the base layer using a printing means, and printing a barrier coating agent on the printed layer using the printing means to form a barrier coat layer, the step of forming the printed layer and the step of forming the barrier coat layer being carried out continuously by the printing means. [9] The method for producing a laminate described in [8] further includes a step of printing an anchor coating agent on the printing layer by a printing means to form an anchor coat layer between the step of forming the printing layer and the step of forming the barrier coat layer, in which the step of forming the printing layer, the step of forming the anchor coat layer, and the step of forming the barrier coat layer are carried out continuously by the printing means.

[10] A method for producing a laminate described in [9], further comprising a step of forming a solid printed layer on the barrier coat layer by a printing means, wherein the steps of forming the printed layer, forming the anchor coat layer, forming the barrier coat layer, and forming the solid printed layer are carried out successively by printing means. Effect of the Invention

[0008] According to the present invention, it is possible to provide a laminate which is a mono-material and has barrier properties, and a method for producing the laminate. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a schematic diagram showing an example of a cross section of a laminate according to the present embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing an example of a cross section of a laminate according to the present embodiment. [Diagram 3] FIG. 2 is a schematic diagram showing an example of a cross section of a laminate according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] In the present invention, whether or not the laminate has a barrier property is evaluated by measuring the oxygen transmission rate of the laminate.

[0011] [Method for measuring oxygen permeability] The oxygen permeability is 2 The oxygen permeability measured at a temperature of 40°C and a humidity of 100% is 300cc / m 2 If the resistance is less than 1000m3 / day atm, it is evaluated as having "barrier properties."

[0012] In the present invention, when the adhesion of the sealant layer is evaluated, it is evaluated by the following tensile test.

[0013] [Tensile test] Test specimen: Laminate A with sealant layer. The shape of laminate A is 15 mm in width and 100 mm in length.

[0014] Test conditions: The base layer of the laminate A was fixed, and the sealant layer was peeled off in a 180° direction at a peel rate (5 mm / min) using a tensile tester. The peel strength (N / 15 mm) was measured and used as adhesion. If the adhesion is 2N / 25mm or more (equivalent value based on a test piece width of 25mm), the sealant layer is evaluated as having high adhesion.

[0015] <Laminate> The present invention is a laminate in which a base layer, a print layer, and a barrier coat layer are laminated. The base layer is made of a polyolefin resin. By bonding the laminates of the present invention together, a packaging container can be manufactured. Since the base layer is made of a polyolefin resin, the packaging container manufactured using the laminate of this embodiment is easy to recycle and has barrier properties. The laminate of the present invention will now be described with reference to the drawings.

[0016] 1 shows a schematic cross-sectional view of an example of a laminate 1 of the present embodiment. The laminate 1 includes a base layer 11, a printed layer 12, and a barrier coat layer 13 laminated in this order. With the laminate 1, a packaging container to which a desired design or textual information is imparted by the printed layer 12 can be produced.

[0017] When the laminates 1 are bonded together with the base material layer 11 on the inside, a packaging container can be produced in which the base material layer 11 faces the contents and the barrier coat layer 13 faces the outside. When bonding the laminates 1 together, an adhesive may be used.

[0018] The laminate of the present embodiment preferably includes an anchor coat layer. 2 shows a schematic cross-sectional view of an example of the laminate 2 of the present embodiment. The laminate 2 includes a base layer 11, a printed layer 12, an anchor coat layer 14, and a barrier coat layer 13 laminated in this order. In the laminate 2, the surface 12a of the printed layer 12 (the surface opposite to the surface where the printed layer 12 contacts the base layer 11) is covered with the anchor coat layer 14, thereby eliminating unevenness on the surface 12a of the printed layer 12. Since the surface 12a of the printed layer 12 is a uniform surface without unevenness, the printed layer 12 and the barrier coat layer 13 are easily adhered to each other. As a result, the laminate 2 can exhibit higher barrier properties.

[0019] The laminate of the present embodiment preferably includes a solid print layer. 3 shows a schematic cross-sectional view of an example of the laminate 3 of this embodiment. The laminate 3 includes a base layer 11, a printed layer 12, an anchor coat layer 14, a barrier coat layer 13, and a solid printed layer 15 in this order. The solid print layer 15 may be made of a known ink that is suitable for the printing method.

[0020] In the laminate of the present embodiment, the barrier coat layer is preferably pattern-printed. The pattern of the barrier coat layer may be a stripe shape (vertical, horizontal, or diagonal), a lattice shape, a dot shape, or a shape excluding the outer periphery of the bag product.

[0021] By pattern-printing the barrier coat layer on the shape of the bag product excluding the outer periphery, it is possible to eliminate or reduce the exposure of the barrier coat layer at the end of the bag product. In this case, even if polyvinyl alcohol or the like is used as the material for forming the barrier coat layer, a packaging container with improved water resistance can be manufactured.

[0022] In this embodiment, it is preferable to print a pattern in a shape other than the seal portion in accordance with the seal shape, but even if the entire film is printed with a pattern such as stripes, lattices, or dots, the barrier coat layer can be partially removed by overlapping part of the pattern with the seal portion. The barrier coat layer may be matched to the seal shape or to a shape such as stripes, but matching to a shape such as stripes is preferable from the viewpoint of versatility.

[0023] The laminate of the present embodiment may further include a sealant layer. An embodiment in which a sealant layer is provided is as follows. A laminate in which a base layer, a printing layer, a barrier coat layer and a sealant layer are laminated in this order. A laminate in which a base layer, a printing layer, an anchor coat layer, a barrier coat layer and a sealant layer are laminated in this order. A laminate in which a base layer, a printing layer, an anchor coat layer, a barrier coat layer, a solid printing layer and a sealant layer are layered in this order.

[0024] According to the embodiment including the sealant layer, the laminates can be bonded to each other by heat fusing the sealant layers together. Each layer will be described below.

[0025] ≪Base material layer≫ The base layer 11 is made of a polyolefin resin. A specific example of the material forming the base layer 11 is preferably a polyethylene resin, and examples of the material include polyethylene-based resins having relatively high density, such as medium density polyethylene (MDPE) and high density polyethylene (HDPE). The material forming the base layer 11 may be one type of polyethylene-based resin, or a blend of two or more types of polyethylene-based resins. The polyolefin resin forming the base layer 11 is preferably high density polyethylene. The base layer 11 is preferably stretched.

[0026] ≪Printing layer≫ The ink for forming the printed layer 12 may contain a coloring material such as a pigment or a dye, and a binder.

[0027] The binder is not particularly limited, but examples thereof include polyamide, polyurethane, polyester, polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, acrylic polymer, polybutadiene, cyclized rubber, etc. The ink may contain a solvent such as water, an organic solvent, or vegetable oil.

[0028] After printing, the ink can be dried by volatilization of the solvent, hardening of the ink, etc. In order to accelerate the drying of the ink, heating, irradiation with ultraviolet rays, etc. may be performed.

[0029] <Barrier coat layer> The barrier properties of the barrier coat layer 13 include barrier properties against water vapor, barrier properties against oxygen gas, barrier properties against organic compounds, and barrier properties against various other low molecular weight components. The barrier coat layer 13 may have two or more of these barrier properties.

[0030] The thickness of the barrier coat layer 13 is preferably 5 μm or less. Specific examples of the thickness of the barrier coat layer 13 are not particularly limited, but may be about 5 μm, 4 μm, 3 μm, 2 μm, 1 μm, 0.5 μm, 0.2 μm, or 0.1 μm, or an intermediate value between these.

[0031] The barrier coat layer 13 may be formed by depositing a metal such as aluminum, an inorganic compound such as silica or alumina, or diamond-like carbon (DLC) on the outer surface of the inner layer.

[0032] Examples of the barrier coating agent include reactive coating agents that contain a polymeric compound containing a reactive functional group and a crosslinking compound such as a metal compound or polyisocyanate. The reactive coating agent can exhibit barrier properties by crosslinking the polymeric compound by reacting the crosslinking compound with the reactive functional group. Examples of the reactive functional group that can react with the crosslinking compound include a hydroxyl group, a carboxyl group, and an amino group.

[0033] Examples of polymeric compounds that react with the reactive functional group include one or more of polyvinyl alcohol, ethylene-vinyl alcohol copolymer (EVOH), urethane-based polyol compounds, acrylic-based polyol compounds, epoxy-based polyol compounds, polyacrylic acid, acrylic acid-acrylic acid ester copolymers, polysaccharides, and oxazoline group-containing compounds.

[0034] Metal compounds used as crosslinkable compounds include one or more of metal alkoxides, metal halides, and metal chelate compounds. Metal elements contained in the metal compounds include silicon, titanium, zirconium, tin, and aluminum. Metal alkoxides include metal methoxides, ethoxides, propoxides, isopropoxides, butoxides, and phenoxides. Metal halides include fluorides, chlorides, bromides, and iodides. Chelate compounds include metal complexes that include hydroxycarboxylic acids such as lactic acid, aminocarboxylic acids, phosphoric acids, and the like as chelating ligands.

[0035] Examples of the polyisocyanate used as the crosslinkable compound include one or more of diisocyanate compounds such as hexamethylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, and isophorone diisocyanate, and polyisocyanate compounds obtained as derivatives of diisocyanate compounds.

[0036] The barrier coating agent may be a coating agent containing a barrier polymer compound. Examples of the barrier polymer compound include polyvinylidene chloride, polyvinyl alcohol, and ethylene-vinyl alcohol copolymer (EVOH). A coating material obtained by dissolving or dispersing the barrier polymer compound in a solvent is applied, and then the solvent is volatilized to form a barrier coating layer.

[0037] The barrier coating agent may contain water or an organic solvent as a solvent. The organic solvent may be one or more selected from alcohol-based solvents such as methanol, ethanol, and 2-propanol; ketone-based solvents such as acetone and methyl ethyl ketone; glycol ether-based solvents such as 2-methoxyethanol and dimethoxyethane; ester-based solvents such as ethyl acetate; and aromatic solvents such as toluene. Ethyl acetate, which has a low evaporation energy, is preferred.

[0038] The barrier coating agent may contain additives such as inorganic compound particles such as silica and alumina, clay minerals, fillers such as fillers, silane coupling agents, antioxidants, UV absorbers, light stabilizers, antistatic agents, colorants, crosslinking agents, crosslinking accelerators, curing agents, etc. The barrier coating layer may contain a resin, or may be a barrier coating layer that does not contain a resin. In order to improve the barrier properties, it is preferable to contain an inorganic filler.

[0039] <Anchor coat layer> Examples of the anchor coating agent for forming the anchor coating layer 14 include imine-based, isocyanate-based, urethane-based, polyether-based, and alkyl titanate (organic titanium compound). The amount of the anchor coating agent applied to form the anchor coating layer 14 is 0.05 g / m 2 More than 2.0g / m 2 The following are preferred: It is preferred that the anchor coating agent has little initial tack.

[0040] <Sealant layer> The sealant layer can be used for bonding the laminate. The sealant layer is preferably formed from a non-oriented polyethylene resin. The thickness of the sealant layer is not particularly limited, but may be, for example, about 60 to 180 μm. The sealant layer may have two or more polyethylene resin layers. The polyethylene resin layer of the sealant layer can be formed from a polyethylene resin film.

[0041] Specific examples of the material forming the sealant layer include polyethylene resins such as linear low density polyethylene (LLDPE), low density polyethylene (LDPE), high density polyethylene (HDPE), etc. The material forming the sealant layer may be one type of polyethylene resin or a blend of two or more types of polyethylene resins.

[0042] In this embodiment, the proportion of the polyethylene resin in the total amount of resins constituting the laminate is preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 98% by mass or more. When the ratio of the polyethylene resin to the total amount of resins constituting the laminate is equal to or greater than the above lower limit, recycling becomes easier. Recycled polyethylene can also be used as the polyethylene resin.

[0043] In this embodiment, the constituent monomer of the polyethylene resin may be a compound derived from a fossil resource such as petroleum, or may be a compound derived from biomass such as a plant.

[0044] <Method of Manufacturing Laminate 1> The laminate 1 can be produced by forming a printed layer 12 on a base layer 11 by printing means, and further applying a barrier coating agent on the printed layer 12 by printing means to form a barrier coat layer 13. The step of forming the printed layer and the step of forming the barrier coat layer are carried out successively by printing means. "Successively by printing means" means, for example, applying ink for forming the printed layer by a gravure method onto the base layer to form the printed layer, and after forming the printed layer, subsequently applying ink for forming the barrier coat layer onto the printed layer to form the printed layer.

[0045] The laminate 2 can be produced by forming a printed layer 12 on a base layer 11 by printing means, further applying an anchor coating agent on the printed layer 12 by printing means to form an anchor coating layer 14, and further applying a barrier coating agent by printing means to form a barrier coating layer 13. The step of forming the printed layer, the step of forming the anchor coating layer, and the step of forming the barrier coating layer are carried out successively by printing means.

[0046] The laminate 3 can be produced by forming a printed layer 12 on a base layer 11 by printing means, further applying an anchor coating agent on the printed layer 12 by printing means to form an anchor coating layer 14, further applying a barrier coating agent by printing means to form a barrier coating layer 13, and further performing solid printing by printing means to form a solid printed layer 15. The step of forming the printed layer, the step of forming the anchor coating layer, the step of forming the barrier coating layer, and the step of forming the solid printed layer are carried out successively by printing means.

[0047] Examples of printing methods that can perform the above-mentioned continuous printing include gravure printing, letterpress printing, offset printing, screen printing, inkjet printing, etc. By using such printing methods, the ink of the material for forming each layer may be printed in a solid or patterned manner.

[0048] When a sealant layer is further formed, the sealant layer may be laminated by a dry lamination method or an extrusion method.

[0049] ≪Packaging body≫ Examples of packaging using the laminate of this embodiment include packaging bags such as pouches and bags, tubes, containers, sleeve packaging, and strip packaging lids. Specific examples of packaging bags include three-sided sealed bags, four-sided sealed bags, pillow bags, gusset bags, and standing pouches. When the laminate is a flexible laminate film, a soft packaging can be formed. The packaging may be formed only from the above-mentioned laminate, or may be combined with accessories such as labels, tags, straws, and outer boxes. From the viewpoint of recycling, it is preferable that the accessories can be separated from the packaging. EXAMPLES

[0050] The present invention will now be described in detail with reference to examples.

[0051] <Example 1> A laminate 1A was produced, which had a base layer 11, a printed layer 12, a barrier coat layer 13 and a sealant layer in this order. High density polyethylene having a thickness of 25 μm was used as the base material layer 11. A pattern or the like was printed on the base material layer 11 using a gravure printing machine to form the printed layer 12.

[0052] Next, a barrier coating agent (PVA-based) was filled into the printer instead of ink, and the barrier coating agent was printed on the entire surface of the printed layer 12 opposite to the surface in contact with the base layer 11, forming a barrier coating layer 13. The coating amount of the barrier coating agent was 0.2 g / m 2 It was decided.

[0053] An adhesive was applied to the surface of the barrier coat layer 13 opposite to the surface in contact with the printed layer 12, and a linear low-density polyethylene film (thickness 120 μm) was laminated by dry lamination to form a sealant layer, thereby obtaining a laminate 1A.

[0054] The laminate 1A has a sealant layer peel strength of 3.2 N / 25 mm and an oxygen permeability of 11.8 cc / m 2 ·day·atm.

[0055] <Example 2> A laminate 2A was produced, which was provided with a base layer 11, a printed layer 12, an anchor coat layer 14, a barrier coat layer 13 and a sealant layer in this order.

[0056] High density polyethylene having a thickness of 25 μm was used as the base material layer 11. A pattern or the like was printed on the base material layer 11 using a gravure printing machine to form the printed layer 12. Next, the printer was filled with an anchor coating agent instead of ink, and the anchor coating agent was printed on the entire surface of the printed layer 12 opposite to the surface in contact with the base layer 11, to form an anchor coating layer 14. The coating amount of the anchor coating agent was 0.5 g / m 2 It was decided.

[0057] Next, a barrier coating agent (PVA-based) was filled into the printer instead of ink, and the barrier coating agent was printed on the entire surface of the anchor coating layer 14 opposite to the surface in contact with the printing layer 12, forming a barrier coating layer 13. The coating amount of the barrier coating agent was 0.2 g / m 2 It was decided.

[0058] An adhesive was applied to the surface of the barrier coat layer 13 opposite to the surface in contact with the anchor coat layer 14, and a linear low-density polyethylene film (thickness 120 μm) was laminated by dry lamination to form a sealant layer, thereby obtaining laminate 2A.

[0059] The film of Laminate 2A broke during the tensile test, and the peel strength of the sealant layer could not be measured. The oxygen permeability of Laminate 2A was 6.5 cc / m 2 ·day·atm.

[0060] <Example 3> A laminate 3A was obtained in the same manner as in Example 1, except that the base material layer 11 was changed from a high density polyethylene having a thickness of 25 μm to a non-oriented high density polyethylene having a thickness of 25 μm.

[0061] The laminate 3A has a sealant layer peel strength of 3N / 25mm and an oxygen permeability of 15cc / m 2 ·day·atm.

[0062] <Example 4> A laminate 4A was obtained in the same manner as in Example 1, except that the barrier coating agent was changed from a PVA-based agent to an epoxy-based agent. The laminate 4A has a sealant layer peel strength of 3.3 N / 25 mm and an oxygen permeability of 65 cc / m 2 ·day·atm.

[0063] <Comparative Example 1> High density polyethylene having a thickness of 25 μm was used as the base material layer 11. A pattern or the like was printed on the base material layer 11 using a gravure printing machine to form the printed layer 12.

[0064] An adhesive was applied to the surface of the printed layer 12 opposite to the surface in contact with the base layer 11, and a linear low-density polyethylene film (thickness: 120 μm) was laminated thereon by dry lamination to form a sealant layer, thereby obtaining a laminate X.

[0065] The film of Laminate X broke during the tensile test, and the peel strength could not be measured. The oxygen permeability of Laminate X was 988cc / m 2 ·day·atm. [Explanation of symbols]

[0066] 1 to 3: laminate, 11: base material layer, 12: printed layer, 13: barrier coat layer, 14: anchor coat layer, 15: solid printed layer

Claims

1. A laminate comprising at least a substrate layer, a printed layer, and a barrier coat layer, the substrate layer being made of a polyolefin resin.

2. The laminate of claim 1 , further comprising an anchor coat layer.

3. The laminate according to claim 2 , wherein a substrate layer, a printing layer, an anchor coat layer and a barrier coat layer are laminated in this order.

4. The laminate of claim 2 , further comprising a solid print layer.

5. The laminate according to claim 4 , comprising a substrate layer, a print layer, an anchor coat layer, a barrier coat layer and a solid print layer laminated in this order.

6. The laminate according to claim 1 , wherein the barrier coat layer is pattern printed.

7. The laminate according to claim 1 or 2, further comprising a sealant layer.

8. A method for producing a laminate having a substrate layer, a printing layer, and a barrier coat layer, comprising the steps of: The base layer is made of a polyolefin resin, forming a printing layer on the base layer using a printing means; and printing a barrier coating agent on the printing layer by a printing means to form a barrier coating layer. A method for producing a laminate, wherein the step of forming the printed layer and the step of forming the barrier coat layer are carried out successively by a printing means.

9. 9. The method for producing a laminate according to claim 8, further comprising a step of printing an anchor coating agent on the printing layer by a printing means to form an anchor coat layer between the step of forming the printing layer and the step of forming the barrier coat layer, wherein the step of forming the printing layer, the step of forming the anchor coat layer, and the step of forming the barrier coat layer are carried out continuously by the printing means.

10. The method for producing a laminate according to claim 9, further comprising a step of forming a solid printing layer on the barrier coat layer by a printing means, wherein the steps of forming the printing layer, forming the anchor coat layer, forming the barrier coat layer, and forming the solid printing layer are carried out successively by the printing means.

Images