Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/16—Layered products comprising a layer of synthetic resin specially treated, e.g. irradiated
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
  • B32B7/02—Physical, chemical or physicochemical properties
  • B32B7/022—Mechanical properties
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D65/00—Wrappers or flexible covers; Packaging materials of special type or form
  • B65D65/38—Packaging materials of special type or form
  • B65D65/40—Applications of laminates for particular packaging purposes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F20/00—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride, ester, amide, imide or nitrile thereof
  • C08F20/02—Monocarboxylic acids having less than ten carbon atoms, Derivatives thereof
  • C08F20/10—Esters
  • C08F20/26—Esters containing oxygen in addition to the carboxy oxygen
  • C08F20/28—Esters containing oxygen in addition to the carboxy oxygen containing no aromatic rings in the alcohol moiety
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D4/00—Coating compositions, e.g. paints, varnishes or lacquers, based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond ; Coating compositions, based on monomers of macromolecular compounds of groups C09D183/00 - C09D183/16

Definitions

• Embodiments of the present invention relate to a laminate and a method for manufacturing the laminate.
• active energy ray curing technology has expanded in the printing industry.
• active energy ray curing technology it is possible to shorten process time by instant drying, reduce the environmental impact by not containing volatile components (Non-VOC), and improve work safety, and it is also possible to achieve strong coating film properties through crosslinking reactions.
• active energy ray curing technology has traditionally been focused on commercial printed matter based on paper substrates, such as flyers and posters.
• printing technology including printing machines and printing inks
• the use of active energy ray curing technology in a variety of fields has been considered in recent years.
• the above curing technology is also used in the field of printed matter (laminates) that use various film substrates, and the use of the above laminates as packaging materials for packaged products, such as packaging for food, cosmetics, and toys, is expanding.
• Packaging materials are made up of a laminate consisting of multiple film substrates bonded together with an adhesive, and are broadly divided into reverse-printed and front-printed configurations.
• the mainstream configuration was one in which the printed image was visible through the film substrate, i.e., the reverse-printed configuration.
• a layer of ink or varnish is the outermost surface (top layer), i.e., the front-printed configuration.
• an overcoat varnish is applied to the surface of the ink coating to form a varnish layer (overcoat layer) in order to protect the ink coating.
• a varnish layer overcoat layer
• active energy ray-curable varnishes which have strong coating properties, are being considered.
• a laminate having a layer composed of a heat-sealable material such as a heat seal layer is used.
• a laminate having a heat seal layer is used as a packaging material with the above-mentioned surface printing configuration, high heat of generally 150 to 180°C, and around 250°C depending on the application, is applied from above the ink or varnish coating film that forms the outermost layer during the heat sealing process. Therefore, the ink or varnish coating film that forms the outermost layer is required to have a higher level of heat resistance than is required for normal use.
• Patent Document 1 discloses a photopolymerizable resin composition for forming a printing layer in a packaging material, which contains a hydrogen abstraction type photopolymerization initiator having a molecular weight of 220 or more and a melting point of 60°C or more, and a radical polymerizable compound.
• a hydrogen abstraction type photopolymerization initiator having a molecular weight of 220 or more and a melting point of 60°C or more
• a radical polymerizable compound As seen in Patent Document 1, ultraviolet (UV) curable compositions are the mainstream of active energy ray curable inks or varnishes used in packaging materials.
• ultraviolet (UV) curable compositions contain a certain amount or more of photopolymerization initiator, which becomes an inert component and is likely to reduce the strength and heat resistance of the cured coating film.
• EB curable compositions which do not require photopolymerization initiators, cause less thermal damage to the substrate, and can be cured with high-energy electron beams, are attracting attention, particularly from the perspective of improving heat resistance and odor compared to ultraviolet (UV) curable compositions.
• the varnish layer of the laminate is required to not only be resistant to the applied heat (heat resistance of the varnish layer itself), but also to suppress the effects of stress caused by heating. Specifically, the varnish layer is required to resist stress caused by deformation or shrinkage of the heat seal layer due to heating, and stress caused by shrinkage of the base material due to heating, and to suppress deformation of the heat seal layer and base material. Therefore, it is necessary to optimize the varnish layer of the laminate in terms of both hardness and brittleness.
• the varnish layer is required to have gloss, slip properties to withstand impacts and friction during transportation, adhesion, etc. Furthermore, solvent resistance is required to withstand alcohol disinfection as a recent measure against infectious diseases.
• the present invention provides a laminate having excellent heat resistance, gloss, slip properties, solvent resistance, and low odor, and a method for producing the same.
• the embodiments of the present invention include the following.
• the present invention is not limited to the following embodiments and includes various embodiments.
• One embodiment of the present invention is a laminate having a substrate and a varnish layer provided on one side of the substrate,
• the varnish layer is a layer made of a cured product of an electron beam curable composition containing a (meth)acrylate compound, the (meth)acrylate compound includes a compound having two or more (meth)acryloyl groups in the molecule, and the content of the compound having two or more (meth)acryloyl groups in the molecule is 80 mass% or more based on the total mass of the electron beam curable composition,
• the electron beam curable composition is substantially free of a photopolymerization initiator,
• the varnish layer relates to a laminate having a hardness of 100 to 180 MPa as measured by the nanoindentation method and a recovery rate of 77 to 100% as measured by the nanoindentation method.
• One embodiment of the present invention relates to a packaging material formed using the laminate of the above embodiment.
• One embodiment of the present invention is a method for producing the laminate of the above embodiment, Applying an electron beam curable composition to one surface of a substrate to form a coating film; and irradiating the coating film with an electron beam to cure the coating film, thereby forming a varnish layer made of a cured product of the electron beam curable composition.
• the electron beam irradiation conditions are an acceleration voltage of 50 to 200 kV and an exposure dose of 15 to 200 kGy.
• the present invention provides a laminate that is excellent in heat resistance, gloss, slip properties, solvent resistance, and low odor, and a method for producing the laminate.
• One embodiment of the present invention relates to a laminate having a substrate and a varnish layer formed on one surface of the substrate.
• the varnish layer is made of a cured product of an electron beam curable composition containing a (meth)acrylate compound, and is characterized in that the hardness measured by the nanoindentation method is 100 to 180 MPa and the recovery rate measured by the nanoindentation method is 77 to 100%.
• the electron beam curable composition contains a compound having two or more (meth)acryloyl groups in the molecule as the (meth)acrylate compound, and the content of the compound having two or more (meth)acryloyl groups is 80 mass% or more based on the total mass of the electron beam curable composition.
• the electron beam curable composition does not substantially contain a photopolymerization initiator and is curable by irradiation with an electron beam.
• the laminate of this embodiment may have other layers in addition to the substrate and the varnish layer formed on one side of the substrate and composed of a cured product of the electron beam curable composition.
• the varnish layer preferably constitutes the outermost layer of the laminate. Since the varnish layer of the laminate of this embodiment is composed of a cured product of the electron beam curable composition, excellent coating properties can be easily obtained. Therefore, the laminate of this embodiment can be used in a variety of applications, and is particularly preferably used as a packaging material.
• the laminate has a heat-sealable structure.
• the laminate may further have a layer (heat-seal layer) made of a heat-sealable material in addition to the substrate and varnish layer.
• the laminate may have a substrate made of a heat-sealable material (called a heat-sealable substrate) and a varnish layer.
• the laminate preferably has a substrate, a varnish layer formed on one surface of the substrate and made of a cured product of an electron beam curable composition, and a heat seal layer provided on the other surface of the substrate (the surface opposite to the surface on which the varnish layer is formed). That is, the laminate preferably has a heat seal layer, a substrate, and a varnish layer in this order.
• heat sealing processing in the packaging field is performed by folding a packaging material (laminate) into a bag shape or by placing the laminate on the top of a container as a lid material and then heating only the end of the laminate (heat seal processing part).
• the end of the outermost layer of the laminate can also be composed of a heat seal layer or a heat sealable substrate.
• a varnish layer can be formed on the heat sealable substrate in an area excluding the end of the substrate, or a heat seal layer can be formed on the substrate and a varnish layer can be formed on the substrate in an area excluding the end of the heat seal layer.
• the part where there is no varnish layer i.e., the end of the heat sealable substrate or the end of the heat seal layer
• a bag-shaped packaging material can be produced by folding the laminate so that the varnish layer is on the inside and performing heat sealing processing on the end of the laminate.
• the laminate may further have a printed layer between the substrate and the varnish layer.
• the printed layer refers to a pattern such as letters and pictures formed using various inks. The configuration of the laminate will be described in more detail below.
• the substrate is not particularly limited and may be a known one.
• the substrate may be made of plastic, metal, paper, or a combination of two or more of these materials, and is preferably in the form of a film or sheet.
• film substrate is preferred.
• film substrate made of plastic includes polyolefin substrate such as polyethylene and polypropylene, polyester substrate such as polyethylene terephthalate and polylactic acid, polycarbonate substrate, polystyrene-based substrate such as polystyrene, AS resin, ABS resin, nylon substrate, polyamide substrate, polyvinyl chloride substrate, polyvinylidene chloride substrate, and cellophane substrate.
• polyolefin substrate such as polyethylene and polypropylene
• polyester substrate such as polyethylene terephthalate and polylactic acid
• polycarbonate substrate polystyrene-based substrate such as polystyrene, AS resin, ABS resin, nylon substrate, polyamide substrate, polyvinyl chloride substrate, polyvinylidene chloride substrate, and cellophane substrate.
• paper substrate made of paper metal substrate made of metal foil such as aluminum, or film substrate made of composite material thereof.
• polyolefin-based film substrate is preferred from the viewpoint of recyclability.
• a vapor-deposited film substrate in which an inorganic compound such as silica, alumina, aluminum, etc. is vapor-deposited onto a film substrate. Furthermore, the vapor-deposited surface may be coated with polyvinyl alcohol or the like.
• the substrate is preferably subjected to an easy-adhesion treatment on the surface to be printed (the surface in contact with the printing layer). Specific examples of the easy-adhesion treatment include corona discharge treatment, ultraviolet/ozone treatment, plasma treatment, oxygen plasma treatment, primer treatment, etc.
• the thickness of the substrate may be preferably 3 to 50 ⁇ m, more preferably 8 to 40 ⁇ m, and even more preferably 10 to 30 ⁇ m.
• a paper substrate may be used as the substrate.
• the paper substrate may be ordinary paper or cardboard, and the thickness is not particularly specified.
• the thickness of the paper substrate may be, for example, 0.2 mm to 1.0 mm and 20 to 150 g/ m2 , and the printed surface may be easily adhesively treated.
• the paper substrate may be vapor-deposited with a metal such as aluminum for the purpose of imparting design.
• the paper substrate may be surface-coated with acrylic resin, urethane resin, polyester resin, polyolefin resin, and other resins, and may further be surface-treated, such as corona treatment.
• specific examples of surface-treated paper substrates include coated paper and art paper.
• a heat-sealable substrate when a heat-sealable laminate is to be formed, can be used as the substrate.
• the heat-sealable substrate include substrates formed using a sealant resin described below. More specifically, substrates include film substrates such as non-oriented polypropylene (CPP) and heat-sealable OPP (also called HSOPP) having a melting point of 100 to 300°C.
• CPP non-oriented polypropylene
• HSOPP heat-sealable OPP
• the thickness of the substrate is preferably adjusted in consideration of the resistance and hardness according to the application. Although not particularly limited, the thickness of the substrate is preferably 3 to 50 ⁇ m, more preferably 8 to 40 ⁇ m, and further preferably 10 to 30 ⁇ m.
• the substrate when a laminate is constructed that further includes a heat seal layer in addition to the substrate and varnish layer, can be preferably a film substrate of at least one plastic selected from the group consisting of polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), and nylon (Ny).
• the polyethylene (PE) may be either low density polyethylene (LLDPE) or high density polyethylene (HDPE), with LLDPE being more preferred.
• the polypropylene (PP) may be either non-oriented polypropylene (CPP) or biaxially oriented polypropylene (OPP).
• One of the above film substrates may be used alone, or two or more may be used in combination.
• a substrate in which a vapor deposition film of a metal or an inorganic compound other than a metal is provided on the above-mentioned film substrate may be used.
• a substrate provided with a vapor deposition film (VM) of a metal such as aluminum can be preferably used from the viewpoint of easily obtaining excellent barrier properties in packaging materials.
• a specific example is a non-oriented polypropylene film (VMCPP) provided with a VM such as aluminum, and among them, VMCPP using aluminum can be preferably used.
• the substrate may be at least one film substrate selected from the group consisting of LLDPE, Ny, CPP, OPP, and VMCPP.
• the varnish layer is composed of a cured product of an electron beam curable composition containing a (meth)acrylate compound, and is a layer obtained by irradiating a coating of the electron beam curable composition with an electron beam to cure the coating.
• (meth)acrylate compound means a compound having a (meth)acryloyl group in the molecule.
• (meth)acrylate means acrylate and/or methacrylate (methacrylate).
• (meth)acryloyl means acryloyl and/or methacryloyl (methacryloyl).
• the electron beam curable composition constituting the varnish layer is not particularly limited as long as the cured coating film satisfies the requirements of the desired hardness and recovery rate of the coating film.
• the electron beam curable composition described below can be preferably used.
• the content of the (meth)acrylate compound in the electron beam curable composition is preferably 80 to 99 mass%, more preferably 85 to 98 mass%, and particularly preferably 90 to 97 mass%, based on the total mass of the composition.
• the varnish layer in the laminate of this embodiment has a hardness of 100 to 180 MPa as measured by the nanoindentation method.
• the hardness of the varnish layer may be preferably 120 to 170, more preferably 130 to 150.
• the hardness as measured by the nanoindentation method is the indentation hardness value measured using a micro-area mechanical property evaluation device (nanoindenter), and in this specification is the value measured using a Hysitron TI Premier (manufactured by Bruker).
• the nanoindenter only indents the very surface layer of the laminate, so it is not affected by the substrate and can measure the mechanical properties of only the thin film varnish layer.
• the varnish layer in the laminate of this embodiment has a recovery rate measured by the nanoindentation method of 77 to 100%.
• the recovery rate may be preferably 80 to 100%, and more preferably 85 to 100%.
• the recovery rate by the nanoindentation method is a value that represents the recovery state of the coating film after indentation, measured using a micro-area mechanical property evaluation device (nanoindenter), and the value described in this specification is a value measured using the same device as that used to measure the hardness of the varnish layer in the laminate. The larger the number, the easier it is to absorb the indentation and return to the original coating state, and in this embodiment, it represents the brittleness of the coating film.
• the specific method for measuring the recovery rate of the varnish layer is as described in the examples below.
• a metal plate heated to 150°C or higher is generally pressed from above the laminate to heat-pressure bond the desired portion. Therefore, during heat sealing, the coating film is subjected to pressure (shock) from above in addition to heat.
• the laminate of this embodiment has a recovery rate of the varnish layer within the above range, which tends to facilitate recovery of the coating film from the impact during heat sealing.
• the varnish layer is characterized by having a hardness of 100 to 180 MPa as measured by the nanoindentation method and a recovery rate of 77 to 100% as measured by the nanoindentation method.
• the higher the hardness value the higher the crosslink density, and the greater the tendency for the coating film to have improved resistance.
• the coating film tends to crack more easily.
• the coating film is more likely to crack depending on the recovery rate (brittleness) of the coating film.
• the varnish layer has the above hardness and recovery rate requirements within the above ranges, so that the heat resistance during heat sealing and the resistance of the coating film to impacts during heat sealing are improved, and problems such as cracking or peeling of the coating film can be easily improved.
• the laminate of this embodiment can achieve the high level of heat resistance required during heat sealing, so it goes without saying that sufficient heat resistance can be obtained even in normal usage.
• the heat seal layer is not particularly limited and can be formed using a material capable of being heat sealed.
• a material known in the art as a sealant resin can be used.
• the sealant resin include polyethylene such as low density polyethylene (LDPE), linear low density polyethylene (LLDPE) and high density polyethylene (HDPE), acid-modified polyethylene, polypropylene (PP), acid-modified polypropylene, copolymerized polypropylene, ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid ester copolymer, ethylene-(meth)acrylic acid copolymer, and polyolefin resin such as ionomer.
• polypropylene-based resins are preferred from the viewpoint of recyclability, and unstretched polypropylene (CPP) is particularly preferred from the viewpoint of heat sealability.
• these resins may be used as they are, or a sealant film in which the resin is previously formed into a film shape may be used.
• the thickness of the heat seal layer is not particularly limited. For example, taking into consideration the processability and heat sealability of the laminate, the thickness is preferably in the range of 10 to 60 ⁇ m, more preferably in the range of 15 to 40 ⁇ m.
• the method for forming (laminating) the heat seal layer is not particularly limited. For example, a method of laminating an adhesive layer and a sealant film by heat (thermal lamination, dry lamination) and a method of melting a sealant resin, extruding it onto the adhesive layer, and cooling and solidifying it to laminate (extrusion lamination method) can be mentioned.
• the laminate in this embodiment may further have a printed layer between the substrate and the varnish layer.
• the print layer is obtained by printing an ink to form a coating film, and drying or curing the coating film as necessary.
• the ink any ink known in the art, such as a solvent-based ink, a water-based ink, or an actinic energy ray-curable ink, can be used.
• an actinic energy ray-curable ink is preferred.
• an actinic energy ray-curable ink is more preferred than an electron beam-curable ink, and a solventless electron beam-curable ink is particularly preferred.
• a method for printing ink on a substrate a method for forming a printed layer
• a known printing method such as offset printing, gravure printing, flexographic printing, inkjet printing, etc. can be selected.
• preferred configuration examples of the laminate of this embodiment include substrate (PE)/varnish layer, substrate (CPP)/varnish layer, substrate (PET)/varnish layer, substrate (CPP/PET)/varnish layer, substrate (LLDPE/Ny)/varnish layer, substrate (VMCPP)/varnish layer, and substrate (VMCPP/OPP)/varnish layer.
• laminate of this embodiment examples include substrate (PE)/printed layer/varnish layer, substrate (CPP)/printed layer/varnish layer, substrate (PET)/printed layer/varnish layer, substrate (CPP/PET)/printed layer/varnish layer, substrate (LLDPE/Ny)/printed layer/varnish layer, substrate (VMCPP)/printed layer/varnish layer, and substrate (VMCPP/OPP)/printed layer/varnish layer.
• an example of a laminate having a heat-sealable configuration is a configuration in which a heat-sealable layer is provided on the other side of the substrate of the laminate exemplified above.
• the laminate may have a heat-sealable layer/substrate/varnish layer configuration, and may further have a printed layer between the substrate and the varnish layer.
• Another example is a laminate using a heat-sealable substrate such as HSOPP as the substrate of the laminate exemplified above.
• the laminate may have a heat-sealable substrate/varnish layer configuration, and may further have a printed layer between the substrate and the varnish layer.
• the laminate of this embodiment can be suitably used as a packaging material.
• Various forms of packaging materials can be constructed using the laminate of this embodiment.
• a packaging material can be provided in which the heat-sealable laminate is processed into the shape of a lid for a container, or into a bag-like shape such as a pouch.
• a packaging material can be provided that is processed into a shape such as a clear file.
• a clear file can be produced by folding the laminate and crimping one of the ends following the fold (the part that will become the bottom of the clear file) with ultrasound or the like.
• the laminate can be used in its original shape as a packaging material such as a packaging film.
• Electron beam curable composition One embodiment of the present invention relates to an electron beam curable composition (also referred to as a varnish layer forming composition) that can be suitably used as a material for forming the varnish layer in the laminate of the above embodiment.
• an electron beam curable composition also referred to as a varnish layer forming composition
• the electron beam curable composition of the present embodiment contains a (meth)acrylate compound.
• the (meth)acrylate compound refers to a compound having a (meth)acryloyl group in the molecule.
• the content of the (meth)acrylate compound is preferably 80 mass% or more, and the content of the (meth)acrylate compound is preferably 80 to 99 mass%, more preferably 85 to 98 mass%, and particularly preferably 90 to 97 mass%, of the total amount of the composition.
• the (meth)acrylate compound that can be used to constitute the electron beam curable composition of this embodiment include 1,3-butylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,2-dodecanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyethylene glycol (200) di(meth)acrylate, polyethylene glycol (300) di(meth)acrylate, polyethylene glycol (400) di(meth)acrylate, and polyethylene glycol (600) di(meth)acrylate.
• difunctional (meth)acrylate compound examples include hydroxypivalic acid neopentyl glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, EO-modified 1,6-hexanediol di(meth)acrylate, PO-modified neopentyl glycol di(meth)acrylate, (neopentyl glycol-modified) trimethylolpropane di(meth)acrylate, dimethyloltricyclodecane di(meth)acrylate, EO-modified bisphenol A di(meth)acrylate, PO-modified bisphenol A di(meth)acrylate, cyclohexanedimethanol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, and tris(2-hydroxyethyl)isocyanurate di(meth)acrylate.
• trifunctional (meth)acrylate compounds such as trimethylolpropane tri(meth)acrylate, EO-modified trimethylolpropane tri(meth)acrylate, glycerin propoxy triacrylate, PO-modified trimethylolpropane tri(meth)acrylate, ⁇ -caprolactone-modified tris-(2-acryloxyethyl)isocyanurate, ethoxylated isocyanuric acid tri(meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, and pentaerythritol tri(meth)acrylate; tetrafunctional radical (meth)acrylate compounds such as pentaerythritol tetra(meth)acrylate and ditrimethylolpropane tetra(meth)acrylate; pentafunctional (meth)acrylate compounds
• urethane acrylates such as aliphatic urethane acrylates and aromatic urethane acrylates, polyester acrylates, polyether acrylates, epoxy acrylates, etc. can be used.
• the (meth)acrylate compounds may be used alone or in combination of two or more.
• the (meth)acrylate compound preferably contains a polyfunctional acrylate having two or more (meth)acryloyl groups in the molecule.
• the content of the polyfunctional (meth)acrylate having two or more (meth)acryloyl groups in the molecule is preferably 80 mass% or more.
• the content of the (meth)acrylate compound is preferably 80 to 99 mass%, more preferably 85 to 98 mass%, and particularly preferably 90 to 97 mass%.
• the polyfunctional (meth)acrylate is preferably a (meth)acrylate compound having three or more (meth)acryloyl groups in the molecule.
• the content of the (meth)acrylate compound having three or more in the molecule may be 50 mass% or more, more preferably 60 mass% or more, and even more preferably 70 mass% or more.
• the content may be preferably 80 mass% or more, more preferably 85 mass% or more, and even more preferably 90 mass% or more, based on the total mass of the polyfunctional acrylate.
• the (meth)acrylate compound preferably contains alkylene oxide-modified (3 to 9 mol/mol) trimethylolpropane triacrylate.
• alkylene oxide-modified (3 to 9 mol/mol) trimethylolpropane triacrylate By containing alkylene oxide-modified (3 to 9 mol/mol) trimethylolpropane triacrylate, the hardness and recovery rate of the varnish layer become good, and the heat resistance of the laminate becomes good. It is more preferable that the alkylene oxide modification amount of the alkylene oxide-modified trimethylolpropane triacrylate is 3 to 6 mol/mol.
• the alkylene oxide-modified (3 to 9 mol/mol) trimethylolpropane triacrylate is preferably ethylene oxide-modified (3 to 9 mol/mol) trimethylolpropane triacrylate or propylene oxide-modified (3 to 9 mol/mol) trimethylolpropane triacrylate. More preferably, it may be ethylene oxide-modified (3 to 6 mol/mol) trimethylolpropane triacrylate or propylene oxide-modified (3 to 6 mol/mol) trimethylolpropane triacrylate.
• the content of the alkylene oxide-modified (3 to 9 mol/mol) trimethylolpropane triacrylate is preferably 20 to 90 mass% based on the total mass of the electron beam curable composition. In some embodiments, the content may be preferably 50 to 90 mass%, more preferably 60 to 90 mass%, and even more preferably 70 to 85 mass%.
• the (meth)acrylate compound contains dipentaerythritol hexaacrylate.
• dipentaerythritol hexaacrylate By containing dipentaerythritol hexaacrylate, the hardness of the varnish layer is improved, and the heat resistance of the laminate is improved.
• the amount is 5 to 50 mass % based on the total mass of the electron beam curable composition.
• the (meth)acrylate compound contains tripropylene glycol diacrylate.
• the gloss of the laminate becomes good.
• the content is 5 to 50 mass % based on the total mass of the electron beam curable composition, more preferably 5 to 30 mass %, and even more preferably 9 to 20 mass %.
• the electron beam curable composition of this embodiment may further contain an extender pigment, resin particles, and a leveling agent.
• the electron beam curable composition in this embodiment preferably further contains an extender pigment, which enhances the film-forming properties of the coating film and improves the slip properties.
• an extender pigment include silica, barium sulfate, alumina white, calcium carbonate, magnesium carbonate, aluminum silicate, magnesium silicate, silicon dioxide, and aluminum hydroxide. These may be used alone or in combination of two or more. Silica is preferred as the extender pigment.
• the content of the extender pigment is preferably from 0.1 to 10% by mass, and more preferably from 1.0 to 5% by mass, based on the total mass of the electron beam curable composition.
• the electron beam curable composition of the present embodiment preferably further contains fine resin particles, which improves slip properties and heat resistance.
• resin microparticles include urethane resin microparticles, acrylic resin microparticles, acrylic-styrene copolymer resin microparticles, polycarbonate resin microparticles, polyethylene resin microparticles, polystyrene resin microparticles, silicone resin microparticles, melamine resin microparticles, melamine-benzoguanamine resin microparticles, melamine-benzoguanamine-formaldehyde resin (condensate) microparticles, polypropylene resin microparticles, amide resin microparticles, polytetrafluoroethylene resin microparticles, and benzoguanamine resin microparticles. These may be used alone or in combination of two or more types as necessary.
• the content of the resin particles is preferably 0.1 to 5 mass % based on the total mass of the electron beam curable composition, and more preferably 0.25 to 3 mass %.
• the resin microparticles may be commercially available or may be manufactured by known manufacturing methods.
• specific examples of urethane resin microparticles include Art Pearl C-1000 transparent, Art Pearl C-600 transparent, Art Pearl C-400 transparent, Art Pearl C-800, and Art Pearl MM-120T, all manufactured by Negami Chemical Industrial Co., Ltd.
• the urethane resin microparticles may also have a crosslinked structure.
• Specific examples of urethane resin microparticles having a crosslinked structure include crosslinked urethane resin microparticles such as Art Pearl JB-800T, Art Pearl JB-600T, Art Pearl P-800T, and Art Pearl P-400T, all manufactured by Negami Chemical Industrial Co., Ltd.
• Acrylic resin microparticles include Art Pearl J4PY and Art Pearl J5PY manufactured by Negami Chemical Industrial Co., Ltd., and Ganz Pearl GB08S manufactured by Aica Kogyo Co., Ltd.
• Other examples include Eposter MA1002, Eposter MA1004, Eposter MA1006, and Eposter MA1010 manufactured by Nippon Shokubai Co., Ltd., Tuftic FH-S005, Tuftic FH-S008, Tuftic FH-S010, Tuftic FH-S015, and Tuftic FH-S020 manufactured by Toyobo Co., Ltd., and Chemisnow MX-80H3wT, MX-150, MX-180TA, MX-300, MX-500, MX-1000, MX-1500H, MX-2000, and MX-3000 manufactured by Soken Chemical & Engineering Co., Ltd.
• acrylic-styrene copolymer resin microparticles include Eposter MA2003 manufactured by Nippon Shokubai Co., Ltd., and FS-102, FS-201, FS-301, MG-451, and MG-351 manufactured by Nippon Paint Industrial Coatings Co., Ltd.
• polycarbonate resin microparticles include the microparticles described in JP 2014-125495 A, the microparticles obtained by the manufacturing method described in JP 2011-26471 A, and the microparticles obtained by the method described in JP 2001-213970 A.
• silicone resin microparticles include KMP-594, KMP-597, KMP-598, KMP-600, KMP-601, and KMP-602 manufactured by Shin-Etsu Chemical Co., Ltd., Trefil E-506S and EP-9215 manufactured by Dow Corning Toray Co., Ltd., and the Tosulpearl series manufactured by Momentive Corporation.
• polyethylene resin microparticles include Mipelon XM-220 and XM221U manufactured by Mitsui Chemicals, Inc., Flow Beads LE-1080 manufactured by Sumitomo Seika Chemicals Co., Ltd., and Ceraflour 991 manufactured by BYK Japan KK.
• polystyrene-based microparticles include Chemisnow SX-130H, SX-350H, and SX-500H manufactured by Soken Chemical & Chemical Industry Co., Ltd.
• melamine resin microparticles include Eposter SS, Eposter S, Eposter FS, Eposter S6, and Eposter S12 manufactured by Nippon Shokubai Co., Ltd.
• melamine-benzoguanamine resin microparticles A specific example of melamine-benzoguanamine resin microparticles is Eposter M30 manufactured by Nippon Shokubai Co., Ltd.
• benzoguanamine resin microparticles include Eposter MS, Eposter M05, and Eposter L15 manufactured by Nippon Shokubai Co., Ltd.
• polytetrafluoroethylene resin microparticles is SST-3T1-RC from Shamrock Technologies.
• the resin microparticles are preferably one or more types selected from the group consisting of silicone resin microparticles, acrylic resin microparticles, polytetrafluoroethylene resin microparticles, and polyethylene resin microparticles, and more preferably one or more types selected from the group consisting of acrylic resin microparticles and polytetrafluoroethylene microparticles.
• silicone resin particles, acrylic resin particles, or polyethylene resin particles are used, particle size control is easy, sphericity is high, and excellent dispersibility can be easily obtained.
• these resin particles have high transparency and can obtain good slip properties while minimizing the loss of gloss.
• polytetrafluoroethylene resin particles are used, excellent heat resistance and slip properties can be obtained due to chemical stability, high melting point, and low coefficient of friction.
• resin fine particles having an average particle size of 2 to 12 ⁇ m, and more preferably 5 to 10 ⁇ m.
• the resin fine particles may be in the form of particles composed of various resins or particles whose surfaces are coated with various resins.
• the resin fine particles may be used alone or in combination of two or more kinds.
• the electron beam curable composition in this embodiment preferably further contains a leveling agent, which improves slip properties.
• the leveling agent preferably contains a silicone-modified acrylate compound.
• the leveling agent may be used alone or in combination of two or more kinds.
• the content of the leveling agent is preferably from 0.1 to 3 mass %, more preferably from 0.4 to 1.5 mass %, and even more preferably from 0.4 to 1.0 mass %, based on the total mass of the electron beam curable composition.
• additives can be added as necessary within the range that does not reduce the effects of the present invention.
• additives that can be used include antistatic agents, surfactants, defoamers, ultraviolet absorbers, antioxidants, curing agents, plasticizers, wetting agents, adhesion aids, defoamers, antistatic agents, trapping agents, antiblocking agents, and preservatives.
• the electron beam curable composition in this embodiment does not substantially contain a photopolymerization initiator.
• substantially does not contain means that it is not added intentionally and that the content due to unintentional addition is less than 1 mass%. Examples of unintentional addition include cases where a trace amount is contained in each raw material, and contamination during the production process of the composition or the production process of the printed matter.
• the electron beam curable composition of this embodiment does not substantially contain organic solvents.
• organic solvents used as viscosity modifiers in printing inks may contain MOSH/MOAH, which are persistent organic pollutants.
• non-VOC volatile components
• the (meth)acrylate compound (A) contained in the electron beam curable composition may be composed of at least one selected from the group consisting of alkylene oxide modified trimethylolpropane triacrylate (A1) and (meth)acrylate compound (A2) other than the above (A1).
• the above (meth)acrylate compound (A) may be a combination of the above (A1) and the above (A2), and the above (A2) includes at least one selected from the group consisting of dipentaerythritol hexaacrylate, tripropylene glycol diacrylate, and trimethylolpropane triacrylate.
• the above (meth)acrylate compound (A) preferably includes alkylene oxide modified trimethylolpropane triacrylate (A1), and the above (A2) includes dipentaerythritol hexaacrylate and tripropylene glycol diacrylate.
• the (meth)acrylate compound (A) is composed only of the (A2), and the (A2) preferably includes two or more selected from the group consisting of dipentaerythritol hexaacrylate, tripropylene glycol diacrylate, and trimethylolpropane triacrylate.
• the (A2) is preferably a combination of dipentaerythritol hexaacrylate/tripropylene glycol diacrylate, or dipentaerythritol hexaacrylate/tripropylene glycol diacrylate/trimethylolpropane triacrylate.
• the electron beam curable composition of this embodiment may further contain, as necessary, a component that does not affect the curing of the coating film, in addition to the (meth)acrylate compound (A) configured as described above.
• the electron beam curable composition may contain, in addition to the (meth)acrylate compound (A) configured as described above, at least one selected from the group consisting of an extender pigment, resin fine particles, and a leveling agent.
• the electron beam curable composition of this embodiment can be produced by mixing and stirring the (meth)acrylate compound and other components, such as resin fine particles, which are used as required, for about 30 minutes to 3 hours using a mixer, etc.
• the (meth)acrylate compound may be produced by mixing and stirring two or more types of (meth)acrylate compounds in advance, and then adding other components, such as resin fine particles, which are used as required.
• the manufacturing method of this embodiment includes applying an electron beam curable composition to one surface of a substrate to form a coating film; irradiating the coating film with an electron beam to cure the coating film, thereby forming a varnish layer made of a cured product of the electron beam curable composition;
• the electron beam irradiation conditions are characterized in that the acceleration voltage is 50 to 200 kV and the exposure dose is 15 to 200 kGy.
• the method for manufacturing the laminate of this embodiment includes a step for forming at least a varnish layer on the substrate.
• the method for manufacturing the laminate of this embodiment may include other steps in addition to the step of forming the varnish layer, as necessary.
• a step of forming a printing layer may be included, preferably prior to forming the varnish layer on the substrate.
• a step of forming a heat seal layer on the other side of the substrate may be included.
• the step of forming the varnish layer can be carried out according to methods known in the art, and may, for example, include forming a coating of the composition on one side of the substrate and then curing the coating.
• Methods for printing or coating the electron beam curable composition include coating using a roll coater, gravure coater, flexo coater, air doctor coater, blade coater, air knife coater, squeeze coater, impregnation coater, transfer roll coater, kiss coater, curtain coater, cast coater, spray coater, die coater, or the like; offset printing (normal lithographic printing using dampening water and waterless lithographic printing not using dampening water), flexo printing, gravure printing, screen printing, or the like.
• inks such as UV curable type, electron beam curable type, heat drying type, evaporation drying type, oxidation polymerization type, penetration drying type, thermal polymerization type, two-component curable type, liquid toner type, and powder toner type inks may be used in combination, as necessary.
• the coating film is cured by irradiating it with electron beams from an electron beam irradiator to form a varnish layer.
• the irradiation conditions of the electron beam for curing the coating film are preferably adjusted in consideration of the balance between damage to the substrate, such as a film substrate, and the curability of the electron beam curable composition.
• the acceleration voltage is preferably 50 to 200 kV, more preferably 80 to 110 kV.
• the exposure dose is preferably 15 to 60 kGy, more preferably 20 to 45 kGy. When the exposure dose is 15 to 60 kGy, sufficient coating strength is obtained, and problems due to damage to the substrate, such as a decrease in substrate strength, odor, and yellowing, can be easily suppressed.
• ink When manufacturing a laminate having a printing layer, ink is applied prior to application of an electron beam curable composition to form a varnish layer.
• inks known in the art such as solvent-based inks, water-based inks, and active energy ray curable inks can be used, and the printing method can be selected according to the type of ink.
• known printing methods such as offset printing, gravure printing, flexographic printing, and inkjet printing can be selected.
• the various inks used in the examples described below can be suitably used.
• an electron beam (EB) curable ink contains a (meth)acrylate compound and a pigment.
• a gravure printing ink contains a binder resin containing a polyurethane resin, a pigment, and a solvent.
• An ultraviolet (UV) curable ink contains a binder resin containing a rosin resin, a (meth)acrylate compound, an initiator, and a pigment.
• Aqueous flexographic printing ink contains a binder resin containing an aqueous polyurethane resin, a solvent containing water and alcohol, and a pigment. The inks may further contain various additives as necessary.
• an electron beam curable ink when used to form a printed layer, the ink is applied to the substrate to form a coating, and then an electron beam curable composition (varnish) is applied (wet-on-wet). Then, electron beams are irradiated to simultaneously cure the ink coating and the varnish coating, forming a printed layer and a varnish layer.
• an electron beam curable composition Varnish
• the ink is applied to the substrate to form a coating, and then the coating is dried or cured to form a printed layer. Then, an electron beam curable composition (varnish) is applied to the printed layer, and then electron beams are irradiated to cure the coating, forming a varnish layer.
• a method of laminating a heat seal layer after preparing a substrate having a varnish layer or a method of forming a varnish layer on a substrate having a heat seal layer may be used.
• the electron beam irradiated when forming the varnish layer may affect the heat seal layer and reduce the heat seal strength depending on the intensity of the electron beam and the type and thickness of the substrate.
• a method of laminating a heat seal layer after preparing a substrate having a varnish layer is applied, a laminate can be manufactured without being affected by the electron beam as described above.
• the varnish layer is a layer obtained by curing an electron beam-curable composition containing a (meth)acrylate compound with an electron beam, the (meth)acrylate compound contains a compound having two or more (meth)acryloyl groups in the molecule in an amount of 80% by mass or more based on the total amount of the electron beam curable composition,
• the electron beam curable composition is substantially free of a photopolymerization initiator,
• the varnish layer has a hardness of 100 to 180 MPa as measured by the nanoindentation method, and a recovery rate of 77 to 100% as measured by the nanoindentation method.
• a packaging material comprising the laminate described in any one of ⁇ 1> to ⁇ 6> above.
• ⁇ 8> A method for producing a laminate described in any one of ⁇ 1> to ⁇ 6> above, wherein the conditions for curing with electron beams are an acceleration voltage of 50 to 200 kV and an exposure dose of 15 to 200 kGy.
• Electron beam curable composition (varnish layer forming composition) ⁇ 1-1> Various Materials Details of the materials used in the Production Examples, Examples, and Comparative Examples described below are as follows.
• ⁇ (Meth)acrylate Compound (A)> Alkylene oxide modified trimethylolpropane triacrylate (A1)) Miramer M3130: manufactured by MIWON Corporation, TMP(EO)3TA (EO (3 mol) modified trimethylolpropane triacrylate) Miramer M3160: manufactured by MIWON Corporation, TMP(EO)6TA (EO (6 mol) modified trimethylolpropane triacrylate) Miramer M3190: MIWON Corporation, TMP(EO)9TA (EO (9 mol) modified trimethylolpropane triacrylate) Miramer M3150: MIWON Corporation, TMP(EO)15TA (EO (15 mol) modified trimethylolpropane triacrylate) Etermer EM2381: Eternal Materials, TMP(PO)3
• Electron beam curable compositions of Production Examples 2 to 25 were obtained in the same manner as in Example 1, except that the materials were used according to the compositions shown in Table 1.
• Ink A (EB curing ink) 23 parts of MOGAL E, 6 parts of EBECRYL 8411, 3 parts of Miramer M122, 10 parts of TPGDA, 46.5 parts of Laromer LR 8863, 5 parts of SR355NS, 6 parts of Solsperse 32000, and 0.5 parts of BYK-1790 were mixed in a compounding ratio and kneaded with a three-roll mill to prepare electron beam curable flexographic ink A.
• EB curing ink 23 parts of MOGAL E, 6 parts of EBECRYL 8411, 3 parts of Miramer M122, 10 parts of TPGDA, 46.5 parts of Laromer LR 8863, 5 parts of SR355NS, 6 parts of Solsperse 32000, and 0.5 parts of BYK-1790 were mixed in a compounding ratio and kneaded with a three-roll mill to prepare electron beam curable flexographic ink A.
• the hardness of the varnish layer by the nanoindentation method is the indentation hardness (H) value measured using a micro-area mechanical property evaluation device (nanoindenter).
• the indentation hardness (H) of the varnish layer was specifically measured as follows.
• a triangular pyramidal Berkovich indenter was used as the indenter of the nanoindenter.
• the Berkovich indenter was pressed into the measurement sample under the indentation conditions described below, and the indentation depth h (nm) was continuously measured against the indentation load F ( ⁇ N) to create a load-displacement curve.
• the maximum indentation load Fmax ( ⁇ N) was calculated from the created load-displacement curve.
• Ac is the contact projected area corrected for the indenter tip curvature using a standard sample of fused quartz by the instrument standard method.
• the indentation conditions were as follows: at room temperature (25° C.), the indenter was first pressed to a depth of 300 nm in 5 seconds (i.e., 60 nm/s), then held at the depth of 300 nm for 2 seconds, and finally unloaded to 0 nm in 5 seconds.
• the recovery rate (%) is an index showing the degree of recovery of the coating film (varnish layer) pressed by the horizontal drive of the indenter.
• the measurement of the recovery rate of the varnish layer was carried out as follows.
• a conical indenter with a conical shape is used as the indenter of the nanoindenter.
• the conical indenter is driven horizontally on the measurement sample under the indentation conditions described below, and the indentation depth h (nm) versus the horizontal movement distance ( ⁇ m) is continuously measured to create a horizontal distance-vertical displacement curve.
• the recovery rate (%) is calculated from the created horizontal distance-vertical displacement curve.
• Example 1 The electron beam curable composition 1 (varnish layer forming composition 1) obtained in Production Example 1 was used to print on a substrate by flexographic printing. The printed coating was immediately irradiated with an electron beam to form a cured coating, thereby producing a laminate. More details are as follows.
• the printing machine used was a Flexiproof 100 manufactured by RK PrintCoat Instruments. The printing conditions were a printing speed of 60 m/min, an anilox roll ruling of 300 Lines/inch, and an anilox roll cell capacity of 13.09 cm3 / m2 . The engraving pattern on the anilox roll was hexagonal.
• the printing plate used was an ESXQ manufactured by DuPont, and the area of the printing plate was 106.8 cm2 .
• the amount of the electron beam curable composition applied was 2.5 to 3.5 g/ m2 after curing.
• the electron beam irradiation was carried out using an electron beam irradiator EC250/15/180L manufactured by Iwasaki Electric Co., Ltd. under conditions of an acceleration voltage of 110 kV and an electron beam dose of 30 kGy.
• the substrate used was a laminate substrate S1 (CPP/OPP) of biaxially oriented polypropylene film (OPP) and non-oriented polypropylene film (CPP).
• the laminate substrate S1 was prepared by the method described below.
• the varnish layer forming composition 1 was printed on the biaxially oriented polypropylene film (OPP) side of the laminate substrate S1 to form a varnish layer.
• the hardness and recovery rate of the varnish layer of the laminate (substrate S1 (CPP/OPP)/varnish layer) obtained as described above were measured according to the above-mentioned method. The results are shown in Table 1.
• the adhesive dilution solution was applied to a biaxially oriented polypropylene film (product name: FOR-BT, thickness 20 ⁇ m) manufactured by Futamura Chemical Co., Ltd., to volatilize the solvent.
• the adhesive dilution solution was applied at room temperature using a bar coater, adjusting the solid coating amount after solvent evaporation to 2.0 to 2.5 g/m 2.
• the adhesive coating surface of the film was bonded to a non-oriented polypropylene film (FHK30 ⁇ m manufactured by Futamura Chemical Co., Ltd.).
• the film was left for 24 hours in an environment of 35 ° C. and humidity 60% RT to 80% RT, to obtain a laminated laminated substrate S1.
• Example 2 to 14 The varnish layer-forming composition 1 used in Example 1 was changed as shown in Table 1.
• the laminates (substrate S1 (CPP/OPP)/varnish layer) of Examples 2 to 14 were obtained in the same manner as in Example 1.
• the hardness and recovery rate of the varnish layer of the laminate obtained as described above were measured by the methods described above. The results are shown in Table 1.
• Example 15 The electron beam irradiation conditions (acceleration voltage 110 kV, electron beam dose 30 kGy) used in forming the varnish layer (cured coating film) in Example 1 were changed to 60 kGy. Otherwise, a laminate (substrate S1 (CPP/OPP)/varnish layer) was produced in the same manner as in Example 1. The hardness and recovery rate of the varnish layer of the laminate obtained as described above were measured by the methods described above. The results are shown in Table 1.
• Example 16 The electron beam irradiation conditions (accelerating voltage 110 kV, electron beam dose 30 kGy) used in forming the varnish layer (cured coating film) in Example 1 were changed to an accelerating voltage of 200 kV. Otherwise, a laminate (substrate S1 (CPP/OPP)/varnish layer) was produced in the same manner as in Example 1. The hardness and recovery rate of the varnish layer of the laminate obtained as described above were measured by the methods described above. The results are shown in Table 1.
• Example 17 The varnish layer-forming composition 1 used in Example 1 was changed as shown in Table 1. Otherwise, a laminate (substrate S1 (CPP/OPP)/varnish layer) was produced in the same manner as in Example 1. The hardness and recovery rate of the varnish layer of the laminate obtained as described above were measured by the methods described above. The results are shown in Table 1.
• Example 20 to 25 The substrate S1 used in Example 1 was changed to the substrates S2 to S8 below. Otherwise, the varnish layer-forming composition 1 was printed on the substrate in the same manner as in Example 1. Furthermore, the coating film formed by the printing was cured by irradiating with electron beams under the same conditions as in Example 1 to form a varnish layer, thereby producing a laminate (substrate/varnish layer). The hardness and recovery rate of the varnish layer of the laminate obtained as described above were measured by the methods described above. The results are shown in Table 1.
• Example 20 Substrate S2 (PE) / varnish layer
• Example 21 Substrate S3 (PET) / varnish layer
• Example 22 Substrate S4 (CPP/PET) / varnish layer
• Example 23 Substrate S5 (LLDPE/Ny) / varnish layer
• Example 24 Substrate S6 (CPP) / varnish layer
• Example 25 Substrate S7 (HSOPP) / varnish layer
• Example 26 Substrate S8 (VMCPP/OPP) / varnish layer
• Example 27 In the same manner as in the printing of the varnish layer-forming composition 1 in Example 1, the EB-curable ink A prepared in Production Example A was printed on the substrate S1 by flexographic printing to form an ink coating. Next, the varnish layer-forming composition 1 was printed on the ink coating by flexographic printing in the same manner as in Example 1, and the ink coating and varnish coating were cured simultaneously by irradiating with an electron beam to produce a laminate (substrate S1 (CPP/OPP)/printed layer/varnish layer). The electron beam irradiation conditions were 110 kV and 30 kGy. The hardness and recovery rate of the varnish layer of the laminate obtained as described above were measured by the methods described above. The results are shown in Table 1.
• Example 28 A gravure ink (Rio Alpha R92 ink (manufactured by Toyo Ink Co., Ltd.)) was printed on the substrate S1 using a gravure five-color press (Fuji Machine five-color press) equipped with a gravure plate with a plate depth of 20 ⁇ m to form an ink coating film, and then the ink coating film was dried to produce a substrate having a printed layer.
• the ink was printed at a printing speed of 150 m/min, and the ink coating film was dried at a temperature of 50° C.
• a varnish layer was formed on the printed surface of the substrate having the printed layer obtained as described above using a composition for forming a varnish layer in the same manner as in Example 1, to produce a laminate (substrate S1 (CPP/OPP)/printed layer/varnish layer).
• substrate S1 CPP/OPP
• the hardness and recovery rate of the varnish layer of the laminate obtained as described above were measured using the methods described above. The results are shown in Table 1.
• Example 29 Water-based flexographic ink "HW 688AQ series" (manufactured by Toyo Ink Co., Ltd.) was adjusted with water to a viscosity of 25 seconds using a Zahn cup #4 manufactured by Rigo Co., Ltd. The ink was printed on the substrate S1 by flexographic printing in the same manner as in the printing of the composition for forming a varnish layer in Example 1 to form an ink coating film, and then the ink coating film was dried to produce a substrate having a printed layer. The printing was carried out using a plate with a cell capacity of 4.3 cm3 / m2 (number of lines: 260 lines/cm). The ink coating film was dried at a temperature of 70°C.
• Example 30 Using a simple color developer RI tester, a UV-curable ink (FD Carton X Ink M (manufactured by Toyo Ink Co., Ltd.) was printed on the substrate S1 so that the film thickness was 1.0 ⁇ m to form an ink coating film, and then the ink coating film was irradiated with ultraviolet light to form a cured coating film, thereby producing a substrate having a printed layer.
• the ultraviolet light irradiation was carried out under the conditions of one high-pressure mercury lamp with an accumulated light amount of 100 mJ/ cm2 .
• a varnish layer was formed on the printed surface of the substrate having the printed layer obtained as described above using a varnish layer forming composition in the same manner as in Example 1, thereby producing a laminate (substrate S1 (CPP/OPP)/printed layer/varnish layer).
• the hardness and recovery rate of the varnish layer of the laminate obtained as described above were measured by the methods described above. The results are shown in Table 1.
• Example 31 Using a simple color developer RI tester, EB curable ink (FD EB AD Ink M (manufactured by Toyo Ink Co., Ltd.) was printed so that the film thickness was 1.0 ⁇ m to form an ink coating.
• varnish layer forming composition 1 was printed on top of the ink coating by flexographic printing in the same manner as in Example 1 to form a varnish coating.
• the ink coating and varnish coating were then cured simultaneously by irradiating with an electron beam to produce a laminate (substrate S3 (PET)/printed layer/varnish layer).
• the electron beam irradiation conditions were 110 kV and 30 kGy.
• the hardness and recovery rate of the varnish layer of the laminate obtained as described above were measured by the methods described above. The results are shown in Table 1.
• Example 32 The varnish layer-forming composition 1 used in Example 1 was changed to a varnish layer-forming composition 18 having the composition shown in Table 1.
• a laminate substrate S1 (CPP/OPP)/varnish layer) was obtained in the same manner as in Example 1 except for the above.
• the hardness and recovery rate of the varnish layer of the laminate obtained as described above were measured by the methods described above. The results are shown in Table 1.
• Example 1 The varnish layer-forming composition 1 used in Example 1 was changed to varnish layer-forming compositions 19 to 25 listed in Table 1. All other compositions were printed on the substrate by flexographic printing in the same manner as in Example 1. Furthermore, an electron beam was irradiated under the same conditions as in Example 1 to harden the coating film formed by the above printing to form a varnish layer, thereby producing a laminate (substrate S1/varnish layer). The hardness and recovery rate of the varnish layer of the laminate obtained as described above were measured by the methods described above. The results are shown in Table 1.
• Example 8 The varnish layer-forming composition 1 used in Example 1 was replaced with a commercially available overcoat varnish, which will be described later.
• the above varnishes were printed on the substrate by flexographic printing in the same manner as in Example 1.
• the coating film after printing was immediately dried to form a varnish layer (dried coating film), and a laminate was produced. More details are as follows. Printing was performed using the same equipment and conditions as in Example 1, with the coating amount adjusted to 0.9 to 1.5 g/ m2 after curing. The coating was dried at a temperature of 70°C for a drying time of 3 minutes. Details of the oil-based varnish and water-based varnish used in Comparative Examples 8 and 9 are as follows.
• the dynamic friction coefficient of each laminate was measured and evaluated according to the following criteria. A rating of "2" or higher is practically preferable.
• the dynamic friction coefficient was measured using a friction tester (HM-3 friction tester, manufactured by Toyo Seiki Seisakusho Co., Ltd.) under the conditions of a speed of 100 mm/min, a travel distance of 50 mm, a sled of 63 mm x 63 mm, and 200 g.
• the (meth)acrylate compound contained 80% by mass or more of a compound having two or more (meth)acryloyl groups in the molecule, based on the total mass of the electron beam curable composition (composition for forming the varnish layer), and the varnish layer was made using a composition that contained substantially no photopolymerization initiator, and the hardness of the laminate was 100 to 180 MPa, and the recovery rate was 77 to 100%.
• the heat resistance, slip properties, solvent resistance, and low odor were at practical levels.
• Comparative Example 1 the hardness was less than 100 MPa, and the heat resistance and solvent resistance were insufficient. This is considered to be due to the influence of the low crosslink density.
• Comparative Example 2 a large amount of a compound having one (meth)acryloyl group in the molecule was used in the electron beam curable composition, and as in Comparative Example 1, the hardness was low and the heat resistance and solvent resistance were insufficient.
• Comparative Example 3 the recovery rate of the varnish layer was less than 77%, and the heat resistance was insufficient. This is thought to be because the hardness of the varnish layer was within a suitable range, but the coating film was highly brittle.
• Comparative Example 4 is an electron beam curable composition containing 20% by mass of an inert resin that does not have a (meth)acryloyl group, and the content of compounds having two or more (meth)acryloyl groups in the molecule is less than 80% by mass based on the total mass of the composition, resulting in a hardness of less than 100 MPa and insufficient solvent resistance and slip resistance. This is thought to be because the inert resin that is not incorporated into the crosslinks is also present on the surface of the coating film.
• Comparative Example 5 the hardness of the varnish layer exceeded 180 MPa and the recovery rate of the varnish layer was less than 77%, indicating insufficient heat resistance.
• Comparative Example 6 the recovery rate of the varnish layer was within the range, but the hardness of the varnish layer exceeded 180 MPa, indicating insufficient heat resistance. Comparative Examples 5 and 6 show that the heat resistance requirements during heat sealing cannot be met simply by increasing the hardness of the varnish layer.
• Comparative Example 7 is a system containing a photopolymerization initiator, and the photopolymerization initiator and its decomposition products are inert components, and the heat resistance is inferior to a system that does not substantially contain a photopolymerization initiator.
• the photopolymerization initiator and its decomposition products have a strong odor, and the system is not suitable for practical use.
• Comparative Examples 8 and 9 are laminates using oil-based varnish and water-based varnish as varnish layers, which are not electron beam curing types. Compared to electron beam curing types, the hardness is significantly smaller and the recovery rate cannot be measured. As a result, the heat resistance and solvent resistance are significantly inferior. In addition, the odor that seems to be due to residual agents was strong.
• the laminate of this embodiment has excellent heat resistance, slip resistance, solvent resistance, and low odor because the varnish layer is composed of an electron beam curable composition and the hardness and recovery rate of the varnish layer are within a specific range.

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