Active energy ray curable composition, and laminate using the same

Abstract

The object of the present invention is to provide an active energy ray curable composition that can convey a rough (rough) texture when the printed and cured surface is touched, while also having good abrasion resistance and printed appearance. [Solution] The above problem can be solved by an active energy ray curable composition containing a polyfunctional urethane (meth)acrylate (A), a monofunctional ethylenically unsaturated monomer (B), and fine particles (C), wherein the median diameter (D50) of the fine particles (C) is 30 μm or more, and the monofunctional ethylenically unsaturated monomer (B) contains a hydroxyalkyl (meth)acrylate.

Description

Technical Field

[0001] The present invention relates to an active energy ray-curable composition and a laminate using the same.

Background Art

[0002] In recent years, in the field of packages using a substrate, for the purpose of imparting added values such as durability, cosmetic property, and texture to printed matter, after printing color ink on various substrates, research on applying a coating varnish has been actively conducted. For example, in view of the case when a printed package is displayed at a store, there may be a requirement for imparting a texture such as glossiness or matte property (matte finish). In response to such a requirement, for example, Patent Document 1 discloses an active energy ray-curable composition for forming a cured layer excellent in substrate adhesion and matte property (cosmetic property).

[0003] Regarding the added value provided by the coating varnish as described above, research has also been conducted on imparting a touch feeling assuming that a human actually touches it by hand. For example, Patent Document 2 discloses an ultraviolet-curable varnish composition that gives a soft touch feeling.

[0004] Imparting a touch feeling by printing, for example, not only improves the premium feeling of a product but also leads to an improvement in the purchasing desire by transmitting the image of the package contents. Alternatively, it also contributes as a means for reducing plastic that replaces the conventional means for imparting a touch feeling by attaching a film. Considering such merits, it is imagined that the demand for touch feeling varies widely regardless of the exemplified soft feeling. Furthermore, from the viewpoint of imparting a touch feeling, it is not limited to the package field, and it can be expected to be applied to a wide range of fields such as building materials, household appliances, precision instruments, electronic devices, and automotive interiors.

[0005] Regarding packaging, when the contents are rough-surfaced items, or when there is a need to impart a paper-like texture through printing, it is appropriate to impart a rough (gritty) feel, the opposite of a soft feel. However, the coating varnishes described in Patent Documents 1 and 2 have not been able to adequately achieve this rough feel.

[0006] Furthermore, given the potential for friction during transportation and applications involving handling heavy objects, it is preferable that the coating varnish has high abrasion resistance. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Patent No. 6919110 [Patent Document 2] Patent No. 7480924 [Overview of the project] [Problems that the invention aims to solve]

[0008] The present invention aims to provide an active energy ray curable composition that can convey a rough (rough) texture when a person touches the printed and cured surface, while also having good abrasion resistance and printed appearance. [Means for solving the problem]

[0009] As a result of diligent research to solve the above problems, we have found that the above problems can be solved by the embodiments shown below, and have completed the present invention.

[0010] An active energy ray curable composition according to one aspect of this disclosure contains a polyfunctional urethane (meth)acrylate (A), a monofunctional ethylenically unsaturated monomer (B), and fine particles (C), The median diameter (D50) of the aforementioned fine particles (C) is 30 μm or more. The monofunctional ethylenically unsaturated monomer (B) includes a hydroxyalkyl (meth)acrylate.

[0011] An active energy ray curable composition according to one aspect of this disclosure is characterized in that the weight-average molecular weight of the polyfunctional urethane (meth)acrylate (A) is 1000 to 7000.

[0012] An active energy ray curable composition according to one aspect of this disclosure contains no organic solvent or contains 5% by mass or less of the total mass of the composition.

[0013] An active energy ray curable composition according to one aspect of this disclosure contains a photopolymerization initiator.

[0014] An active energy ray curable composition according to one aspect of the present disclosure is characterized in that the polyfunctional urethane (meth)acrylate (A) has constituent units derived from a polyether.

[0015] An active energy ray curable composition according to one aspect of this disclosure has a storage modulus (Er) of 50 MPa or more at 25°C for a cured film cured using active energy rays.

[0016] An active energy ray curable composition according to one aspect of this disclosure has a storage modulus (Er) of 100 MPa or more.

[0017] In one aspect of the present disclosure, the active energy ray curable composition has a median diameter (D50) of the fine particles (C) of 40 to 60 μm.

[0018] A coating composition according to one aspect of this disclosure comprises the active energy ray curable composition.

[0019] A laminate according to one aspect of this disclosure comprises a substrate layer and a coating layer. The coating layer is formed from the coating composition.

[0020] In one aspect of the present disclosure, the coating layer of the laminate is coated by screen printing.

[0021] In one aspect of the present disclosure, the film thickness of the coating layer is thinner than the median diameter (D50) of the fine particles (C).

[0022] In one aspect of the present disclosure, the laminate further has a printing layer between the base material layer and the coating layer.

[0023] A method for manufacturing a laminate according to one aspect of the present disclosure is a method for manufacturing a laminate having a base material layer and a coating layer, The method includes a step of applying the coating composition on the base material by screen printing.

Advantages of the Invention

[0024] According to the present invention, it is possible to provide a radiation curable composition that can convey a rough feeling (a feeling of roughness) when touching a printed and cured printing surface, and has good abrasion resistance and printing appearance.

Embodiments for Carrying Out the Invention

[0025] Embodiments of the present invention will be described in detail below. However, the description of the constituent elements described below is an example (representative example) of an embodiment of the present invention, and the present invention is not limited to these contents unless it exceeds the gist thereof.

[0026] The radiation curable composition of the present invention is a radiation curable composition containing a polyfunctional urethane (meth) acrylate (A), a monofunctional ethylenically unsaturated monomer (B), fine particles (C), and optionally a photoinitiator, wherein the median diameter (D50) of the particle size distribution of the fine particles (C) measured based on JIS Z 8825 is 30 μm or more. When the median diameter of the fine particles (C) is 30 μm or more, a structure in which a part of the particles protrudes from the printing surface is formed, and a comfortable rough feeling is conveyed to the fingertips of a human. Furthermore, the reduced specific surface area of ​​the particles suppresses solidification during varnish mixing, enabling high-concentration particle filling and improving the rough texture.

[0027] In the following explanation, (meth)acrylic and (meth)acrylate refer to methacrylic and / or acrylic, and methacrylate and / or acrylate, respectively. Similarly, (meth)acryloyl refers to methacryloyl and / or acryloyl. Furthermore, the term "active energy ray curable composition" may sometimes be simply referred to as "composition," which is synonymous.

[0028] <Polyfunctional urethane (meth)acrylate (A)> The weight-average molecular weight of the polyfunctional urethane (meth)acrylate (A) used in the present invention is preferably 1000 to 7000, more preferably 1500 to 5000, even more preferably 1500 to 3500, and still more preferably 2000 to 3000. Being within this range appropriately maintains the viscosity of the composition, improving its coating suitability, and tends to result in a more uniform coating layer formed from the active energy ray curable resin composition. Furthermore, the increased storage modulus (Er) of the coating layer suppresses the movement of fine particles (C) contained in the coating layer, which tends to improve abrasion resistance and efficiently conveys a rough feel to the fingertips. In addition, maintaining an appropriate viscosity of the composition provides a uniform printed appearance. Furthermore, being polyfunctional tends to result in good abrasion resistance and blocking resistance. The number of functional groups is preferably 2 to 4, more preferably 2 to 3, and still more preferably 2. Here, the number of functional groups refers to the number of polymerizable (meth)acrylate groups and other unsaturated double bond groups.

[0029] The content of polyfunctional urethane (meth)acrylate (A) is preferably 10% to 80% and more preferably 20% to 60% of the total mass of the active energy ray curable composition.

[0030] The glass transition temperature (Tg) of the polyfunctional urethane (meth)acrylate (A) is preferably 0 to 50°C, more preferably 5 to 40°C, even more preferably 10 to 35°C, and still more preferably 15 to 30°C. Being within this range increases the storage modulus (Er) of the coating layer, suppresses the migration of fine particles (C) contained in the coating layer, tends to improve abrasion resistance, and also tends to efficiently transmit a rough feel to the fingertips.

[0031] The polyfunctional urethane (meth)acrylate (A) is preferably of the following nature, for example, one obtained by reacting an isocyanate group-containing urethane prepolymer, which is obtained by reacting a polyol and a polyisocyanate under conditions of excess isocyanate groups, with a (meth)acrylate having hydroxyl groups, or one obtained by reacting a polyisocyanate with a (meth)acrylate having hydroxyl groups. Alternatively, it can also be obtained by reacting a hydroxyl group-containing urethane prepolymer, which is obtained by reacting a polyol and a polyisocyanate under conditions of excess hydroxyl groups, with (meth)acrylates having isocyanate groups.

[0032] <Polyol> The polyols used may be any known polyols, and suitable examples include polyether polyols, polyester polyols, polyolefin polyols (polybutadiene polyols, polyisoprene polyols), polycarbonate polyols, polysiloxane polyols, and (meth)acrylic polyols, which may have an aliphatic or alicyclic structure. Among these, polyether polyols are preferred. When a polyether polyol is used, the polyfunctional urethane (meth)acrylate (A) has structural units derived from polyether. The polyether polyol is preferably, for example, polytetramethylene glycol, polyethylene glycol, polypropylene glycol, polytrimethylene glycol, or copolymers thereof. When the polyfunctional urethane (meth)acrylate (A) has structural units derived from polyether, the dispersibility of fine particles (C) is improved, preventing solidification of the composition, and the dispersibility of fine particles (C) tends to improve the printed appearance.

[0033] <Polyisocyanate> The above polyisocyanates can be any known type, including aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates. Examples of aromatic diisocyanates include 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate (4,4'-MDI), 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl isocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, m-tetramethylxylylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, and 2,6-diisocyanate-benzyl chloride. Examples of aliphatic diisocyanates include butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropyl diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate. Examples of alicyclic diisocyanates include cyclohexane-1,4-diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, dimeryl diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis(isocyanate-methyl)cyclohexane, methylcyclohexane diisocyanate, norbornane diisocyanate, and dimer isocyanates obtained by converting the carboxyl group of a dimer acid to an isocyanate group. These may form trimers and take on structures such as biuret, allophanate, or nurate. These polyisocyanates can be used individually or in combination of two or more. Particularly preferred from the viewpoint of suppressing thickening and appropriately maintaining the hardness of the coating layer formed from the active energy ray curable resin composition are tolylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, hexamethylene diisocyanate, and isocyanurate derivatives of hexamethylene diisocyanate.

[0034] <Hydroxyl group-containing (meth)acrylate> Examples of hydroxyl group-containing (meth)acrylates include trimethylolpropanedi(meth)acrylate, trimethylolethanedi(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, 2-hydroxyethyl (meth)acrylate, 1-hydroxypropyl (meth)acrylate, and 2-hydroxyethyl (meth)acrylate. Examples include hydroxypropyl, 3-hydroxypropyl (meth)acrylate, 1-hydroxybutyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, cyclohexanedimethanol mono(meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, ethyl-α-(hydroxymethyl) (meth)acrylate, monofunctional glycerol (meth)acrylate, or hydroxyl-containing (meth)acrylate esters such as (meth)acrylate esters having a hydroxyl group at the terminal by ring-opening addition of ε-caprolactone lactone to these (meth)acrylates, or alkylene oxide-added (meth)acrylate esters obtained by repeatedly adding alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide to the above hydroxyl-containing (meth)acrylates. Among these, it is preferable to include at least one selected from (meth)acrylate 2-hydroxyethyl, (meth)acrylate 2-hydroxypropyl, and (meth)acrylate 4-hydroxybutyl.

[0035] <Monofunctional ethylenically unsaturated monomer (B)> The inclusion of a monofunctional ethylenically unsaturated monomer (B) improves the dispersibility of fine particles (C), preventing the composition from solidifying and improving the printed appearance. Furthermore, the coating layer formed from the active energy ray curable resin composition does not become too hard, creating a structure in which some of the fine particles (C) protrude from the printed surface, resulting in a rough texture. The monofunctional ethylenically unsaturated monomer (B) used in the present invention includes, for example, alkyl(meth)acrylates with 1 to 18 carbon atoms such as methyl(meth)acrylate, ethyl(meth)acrylate, butyl(meth)acrylate, hexyl(meth)acrylate, octyl(meth)acrylate, dodecyl(meth)acrylate, and stearyl(meth)acrylate. Furthermore, alkylphenols such as benzyl(meth)acrylate, butylphenol, octylphenol, nonylphenol, or dodecylphenol, ethylene oxide adducts (meth)acrylate, isobornyl(meth)acrylate, cyclohexyl(meth)acrylate, tricyclodecane monomethylol(meth)acrylate, 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, 3-hydroxypropyl(meth)acrylate, 2-hydroxybutyl(meth)acrylate, 4-hydroxybutyl(meth)acrylate, and hydroxypentyl(meth)acrylate. Examples include 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-hydroxy-3-butoxypropyl (meth)acrylate, 2-hydroxy-3-methoxypropyl (meth)acrylate, diethylene glycol mono(meth)acrylate, triethylene glycol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate, dipropylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, glycerin mono(meth)acrylate, acrylic acid phthalate, 2-(meth)acryloyloxyethyl-2-hydroxyethyl phthalate, 2-(meth)acryloyloxypropyl phthalate, β-carboxyethyl (meth)acrylate, (meth)acrylate dimer, ω-carboxy-polycaprolactone mono(meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, N-vinylpyrrolidone, N-vinylformamide, (meth)acryloylmorpholine, etc. In particular, the monofunctional ethylenically unsaturated monomer (B) is characterized by containing a hydroxyalkyl (meth)acrylate, from the viewpoint of improving the print appearance by improving the dispersibility of fine particles (C) and improving the roughness by making it easier to create a structure in which some of the fine particles (C) protrude from the print surface. Examples of hydroxyalkyl (meth)acrylates include 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate. The number of carbon atoms in the alkyl group is preferably 2 to 10 or 2 to 6, and more preferably 2 to 4.

[0036] The monofunctional ethylenically unsaturated monomer is preferably present in 5 to 50% by mass, and more preferably 10 to 30% by mass, of the total mass of the active energy ray curable composition, from the viewpoint of lowering the viscosity of the composition, improving the print appearance by improving the dispersibility of fine particles (C), and increasing the storage modulus of the cured film to improve the roughness. Furthermore, the mass ratio of polyfunctional urethane (meth)acrylate (A) to monofunctional ethylenically unsaturated monomer (B) is preferably 50:50 to 90:10. In addition, it is preferable that the total mass of monofunctional ethylenically unsaturated monomer (B) contains 70 to 100% by mass of hydroxyalkyl (meth)acrylate.

[0037] <Difunctional ethylenically unsaturated monomers> The composition of the present invention may contain a difunctional ethylenically unsaturated monomer. Suitable examples of difunctional ethylenically unsaturated monomers include butanediol di(meth)acrylate, hexanediol di(meth)acrylate, octanediol di(meth)acrylate, alkylene glycol di(meth)acrylate, polyethylene glycol 200 di(meth)acrylate (the number represents the molecular weight), polyethylene glycol 300 di(meth)acrylate, polyethylene glycol 400 di(meth)acrylate, polyethylene glycol 600 di(meth)acrylate, polyethylene glycol 1000 di(meth)acrylate, and other polyethylene glycol di(meth)acrylates, as well as tetraethylene glycol di(meth)acrylate and tetramethylene glycol di(meth)acrylate, and those containing a polyether structure are preferred. The amount of bifunctional ethylenically unsaturated monomer is preferably 0.1 to 20% by mass, and more preferably 1 to 10% by mass or less, in the total mass of the composition, from the viewpoint of appropriately maintaining the hardness of the coating layer formed from the active energy ray curable resin composition and providing a moderate rough texture, and from the viewpoint of improving the dispersibility of fine particles (C) and improving the printed appearance. Furthermore, the case where the difunctional ethylenically unsaturated monomer is the polyfunctional urethane (meth)acrylate (A) described above is excluded.

[0038] <Fine particles (C)> The median diameter (D50) of the fine particles (C) used in this invention is 30 μm or larger. Having a median diameter of 30 μm or larger allows a structure to be formed where some of the particles protrude from the coating layer formed from the active energy ray curable resin composition, providing a pleasant rough texture to the human fingertip. Furthermore, the reduced specific surface area of ​​the particles suppresses solidification during varnish formulation, enabling high-concentration particle filling and improving the rough texture. From the viewpoint of improving the printed appearance by increasing the transfer rate of fine particles (C) during printing, and improving the rough texture, the median diameter is preferably 35 to 70 μm, and more preferably 40 to 60 μm. The median diameter is determined from the particle size distribution measured according to JIS Z 8825, for example, from the volume-average particle diameter obtained by laser diffraction. Specifically, it can be determined using, for example, the Microtrac-Bell MT3300EXII. The composition of the fine particles (C) is not particularly limited, but examples include urethane resin fine particles, silicone resin fine particles, melamine resin fine particles, melamine-benzoguanamine resin fine particles, acrylic resin fine particles (e.g., polymethyl methacrylate resin fine particles), acrylic-styrene copolymer resin fine particles, polycarbonate resin fine particles, polyethylene resin fine particles, polystyrene resin fine particles, benzoguanamine resin fine particles, cellulose fine particles, silica fine particles, and metal fine particles. These may be used individually or in combination of two or more types. Among these, urethane resin fine particles and cellulose fine particles are preferred from the viewpoint of producing a moderate rough texture and improving abrasion resistance. Furthermore, two or more types may be used in combination as needed.

[0039] The fine particles (C) are preferably present in an amount of 10 to 70% by mass, more preferably 20 to 60% by mass, and even more preferably 30 to 50% by mass, in the total mass of the composition. When the amount is 10% by mass or more, it is easier to create a structure in which some of the fine particles (C) protrude from the printed surface, which tends to improve roughness. In addition, this structure reduces the contact area and lowers the coefficient of friction, which tends to improve abrasion resistance. When the amount is 60% by mass or less, the viscosity of the composition is reduced, which tends to improve the printed appearance.

[0040] <Photopolymerization initiator> The active energy ray curable composition of the present invention may contain a photopolymerization initiator. The photopolymerization initiator generates radicals upon irradiation with active energy rays such as light, initiating the crosslinking and polymerization reactions of the acrylate groups of the polyfunctional urethane (meth)acrylate and monofunctional ethylenically unsaturated monomer. Suitable photopolymerization initiators include acetophenone-based photopolymerization initiators, alkylphenone-based photopolymerization initiators, benzoin-based photopolymerization initiators, benzophenone-based photopolymerization initiators, and acylphosphine oxide-based photopolymerization initiators, among which acetophenone-based photopolymerization initiators and acylphosphine oxide-based photopolymerization initiators are preferred. From the viewpoint of appropriately maintaining the hardness of the coating layer formed from the active energy ray curable resin composition, the photopolymerization initiator is preferably contained in an amount of 1 to 10% by mass, more preferably 2 to 7% by mass, and even more preferably 3 to 5% by mass in the total mass of the composition.

[0041] Examples of the acetophenone-based photopolymerization initiators include 4-phenoxydichloroacetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, 4-(2-hydroxyethoxy)-phenyl(2-hydroxy-2-propyl)ketone, 2-methyl-[4-(methylthio)phenyl]-2-morpholino-1-propanone, and 2,2-dimethoxy-2-phenylacetophenone.

[0042] Examples of alkylphenone-based photopolymerization initiators include 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)-benzyl]phenyl}-2-methylpropane-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropane-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, and 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone.

[0043] Examples of benzoin-based photopolymerization initiators include benzoin, benzoin methyl ether, benzoin isoethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether.

[0044] Examples of benzophenone-based photopolymerization initiators include benzophenone, 4-methylbenzophenone, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, methyl-o-benzoylbenzoate, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, and 3,3-dimethyl-4-methoxybenzophenone. Among these, 4-methylbenzophenone is preferred.

[0045] Examples of thioxanthone-based photopolymerization initiators include thioxanthone, 2-chlorothioxanthone, 2,4-dichlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, and 2,4-diisopropylthioxanthone.

[0046] Examples of anthraquinone-based photopolymerization initiators include α-acyloxime esters, benzyl methylbenzoyl formate, and 2-ethyl anthraquinone.

[0047] Examples of acylphosphine oxide-based photopolymerization initiators include 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide.

[0048] The aforementioned photopolymerization initiator may be used as one or a combination of two or more.

[0049] <Organic solvents> From the viewpoint of improving the printed appearance and protecting the environment, the composition of the present invention preferably contains no organic solvent or contains 5% by mass or less (0-5% by mass) of the total mass of the composition. More preferably, it is 3% by mass or less, and even more preferably 1.5% by mass or less. Examples of organic solvents that can be used include known solvents used in coating varnishes.

[0050] <Additives> The active energy ray curable composition of the present invention may appropriately contain known additives, such as leveling agents, polymerization inhibitors, ultraviolet absorbers, light stabilizers, sensitizers, curing agents, plasticizers, wetting agents, adhesion aids, defoaming agents, antistatic agents, etc., and there are no particular limitations.

[0051] <Storage modulus of cured film> The storage modulus (Er) at 25°C of the cured film obtained by curing the active energy ray-curable composition of the present invention using active energy rays is preferably 50 MPa or more, more preferably 100 MPa or more, even more preferably 200 MPa or more, and even more preferably 300 MPa or more. A storage modulus of 50 MPa or more suppresses the sinking of fine particles (C) into the cured film under load, and tends to improve the roughness. Furthermore, suppressing the sinking of fine particles (C) into the cured film under load reduces the contact area with the fine particles (C), and tends to improve abrasion resistance. In addition, the storage modulus (Er) is preferably 1000 MPa or less, and even more preferably 800 MPa or less. The storage modulus (Er) is measured according to JIS K 7244. Specifically, it can be determined, for example, using a dynamic viscoelasticity measuring device (DVA-200, manufactured by IT Measurement Control Co., Ltd.).

[0052] <Manufacturing of Activated Energy Ray Curable Compositions> The active energy ray curable composition can be produced by stirring a polyfunctional urethane (meth)acrylate (A), a monofunctional ethylenically unsaturated monomer (B), fine particles (C), and, if necessary, a photopolymerization initiator, with a disperser or similar device for approximately 30 minutes to 3 hours. If mixing is difficult and viscosity tends to be uneven, a roller mill, ball mill, pebble mill, attritor, sand mill, etc., may be used.

[0053] If the active energy ray-curable composition of the present invention contains air bubbles or unexpectedly coarse particles, these can degrade the quality of the printed material, so it is preferable to remove them by filtration or other means. Conventional filters can be used.

[0054] <Coating composition> The coating composition of the present invention is a composition for forming a coating layer and has the same constituent elements as the active energy ray curable composition.

[0055] <Manufacturing of laminates> The active energy ray-curable composition of the present invention can be used as a coating composition containing it in the manufacture of laminates. The method of manufacturing the laminate is not particularly limited, but for example, the active energy ray-curable composition can be printed and coated onto a substrate such as paper or film, and then cured to produce a laminate having a substrate layer / coating layer structure. Alternatively, a printed layer made of a printing ink composition may be formed on the substrate, and a coating layer made of the active energy ray-curable composition of the present invention may be laminated on the printed layer to form a laminate having a substrate layer / printed layer / coating layer structure.

[0056] The printing and coating methods for the active energy ray curable composition are not particularly limited and include wet coating methods such as spraying, showering, dipping, flow coating, gravure printing, flexographic printing, roll printing, spinning, dispenser printing, inkjet printing, and screen printing. Screen printing is preferred from the viewpoint of having a high transfer rate and efficiently printing fine particles to impart a rough texture.

[0057] While there are no particular limitations on the screen plates used for screen printing, a wider mesh size is preferable. A wider mesh size in the screen plate tends to allow fine particles (C) to be transferred to the substrate more efficiently, and also makes it easier for the fine particles (C) to be arranged randomly, resulting in a pleasant rough texture.

[0058] Examples of active energy rays include ultraviolet rays such as far ultraviolet, ultraviolet, and near ultraviolet rays. On the other hand, electron beams and proton beams can also be used, and in this case curing can be achieved without the use of a photopolymerization initiator, but curing by ultraviolet irradiation is preferred due to the curing speed, ease of obtaining irradiation equipment, and cost.

[0059] Methods of curing by ultraviolet irradiation include using high-pressure mercury lamps, ultra-high-pressure mercury lamps, carbon arc lamps, metal halide lamps, xenon lamps, chemical lamps, electrodeless discharge lamps, LEDs, etc., that emit light in the 150-450 nm wavelength range, with an integrated light intensity of 30-5000 mJ / cm².2 Preferably 100-1000 mJ / cm² 2 Simply irradiate it. After UV irradiation, heating can be performed as needed to ensure complete curing.

[0060] The thickness of the coating layer is preferably 1 to 100 μm, more preferably 1 to 50 μm, and even more preferably 1 to 30 μm. In particular, when the thickness is thinner than the median diameter (D50) of the particle size distribution of the fine particles (C) measured according to JIS Z 8825, it is preferable because it makes it easier to create a structure in which some of the fine particles are exposed, and the roughness tends to improve.

[0061] <Base material> The substrate used in this invention can be, for example, a paper substrate or a film substrate. For paper substrates, ordinary paper or corrugated cardboard is preferred, and although there are no specific requirements for film thickness, a thickness of 0.2 mm to 1.0 mm is suitably used, and the printed surface may be corona treated. Furthermore, the paper substrate may have its surface vapor-deposited with a metal such as aluminum to enhance its design, and may also be surface coated with acrylic resin, urethane resin, polyester resin, polyolefin resin, or other resins, and may also be further surface treated with corona treatment. For example, coated cardboard and Mariecoat paper are preferred. For film substrates, ordinary PET (polyethylene terephthalate) and PVC (polyvinyl chloride) are suitable, and there are no particular limitations. A film thickness of 0.02 mm to 1.0 mm is preferably used, and the substrate surface may be corona-treated. Furthermore, the film substrate may be surface-coated with acrylic resin, urethane resin, polyester resin, polyolefin resin, or other resins.

[0062] A single cured film can be obtained by coating the composition of the present invention onto a release PET substrate and curing it with active energy rays. The release PET substrate is not particularly limited, and for example, Cosmopeel E7006 manufactured by Toyobo Co., Ltd. is an example. The coating method is also not particularly limited, but it is preferable to produce a film thickness thicker than the median diameter of the fine particles (C) contained in the composition.

[0063] <Printing ink composition> The aforementioned printing ink composition may include, for example, known gravure ink compositions, flexographic ink compositions, UV-curable flexographic ink compositions, offset ink compositions, UV-curable offset ink compositions, and other ink compositions, and any of these printing ink compositions may be used. In particular, when using UV-curable offset ink compositions or UV-curable flexographic ink compositions, if active energy ray-curable compositions are laminated, curing reactions by ultraviolet light or the like occur between the layers, improving adhesion. For this reason, UV-curable offset ink compositions and UV-curable flexographic ink compositions are more preferred as printing ink compositions.

[0064] <Printing with printing ink> Known methods can be used for printing the printing ink composition. Examples include gravure printing, flexographic printing, offset printing, and screen printing. The thickness of the ink layer is preferably 0.1 to 15 μm, and more preferably 0.5 to 12 μm. The printing ink composition may be organic solvent-based, water-based, or an ultraviolet-curable ink composition. Alternatively, the above printing ink compositions may be combined to form the ink layer, which can then be dried or ultraviolet-cured after printing to form the printed layer.

[0065] The thickness of each layer can be measured from the cross-section of the laminate. The method for cutting the cross-section is not particularly limited and can be, for example, a razor, cutter, microtome, or ion milling, and may be performed after cooling with liquid nitrogen or the like. The method for measuring the thickness is not particularly limited and can be, for example, a laser microscope, optical microscope, or electron microscope. [Examples]

[0066] The present invention will be specifically described below with reference to examples and comparative examples. In the examples and comparative examples, "parts" and "%" mean "parts by mass" and "% by mass" respectively, unless otherwise specified.

[0067] [Method for measuring weight-average molecular weight] The weight-average molecular weight was determined by measuring the molecular weight distribution using a GPC (gel permeation chromatography) instrument (HLC-8220, Tosoh Corporation) and calculating the converted molecular weight using polystyrene as the standard substance. The measurement conditions are shown below. Columns: The following columns were used, connected in series. TSKgelSuperAW2500 manufactured by Tosoh Corporation TSKgel SuperAW3000 manufactured by Tosoh Corporation TSKgel SuperAW4000 manufactured by Tosoh Corporation TSKgelguard Column Super AWH manufactured by Tosoh Corporation Detector: RI (Differential Refractometer) Measurement conditions: Column temperature 40°C Eluent: Tetrahydrofuran Flow rate: 1.0mL / min

[0068] [Method for measuring glass transition temperature] The glass transition temperature (Tg) was measured using a DSC (Differential Scanning Calorimetry) system (Rigaku DSC8231). The glass transition temperature was defined as the midpoint between the endothermic onset temperature and the endheating onset temperature based on the glass transition in the DSC curve. The measurement conditions are shown below. Measurement temperature range: -70 to 150°C Heating rate: 10°C / min

[0069] [Method for measuring the storage modulus (Er)] The storage modulus (Er) was measured using a dynamic viscoelasticity measuring device (DVA-200, manufactured by IT Measurement Control Co., Ltd.) in accordance with JIS K 7244. For comparison, the value at a measurement temperature of 25°C was used. The measurement conditions are shown below. Frequency: 10Hz Measurement temperature range: -100 to 300°C Heating rate: 10°C / min

[0070] <Manufacturing of polyfunctional urethane (meth)acrylate (A)> (Synthesis of polyfunctional urethane (meth)acrylate (A-1)) In a 4 L separable four-necked flask equipped with a stirrer, thermometer, and condenser, 262 parts of dicyclohexylmethane 4,4'-diisocyanate, 2000 parts (2 moles) of polytetramethylene ether glycol, 232 parts of 2-hydroxyethyl acrylate, and 1.247 parts of p-methoxyphenol were charged. The mixture was stirred while introducing air, and the reaction was carried out at 80°C for 4 hours. After confirming the disappearance of the peak attributable to the isocyanate group by IR spectroscopy, the reaction was terminated, and the mixture was cooled to 40°C to obtain (A-1) as a pale yellow liquid. The weight-average molecular weight was 2200.

[0071] (Synthesis of polyfunctional urethane (meth)acrylate (A-2 to A-7)) Polyfunctional urethane (meth)acrylates (A-2 to A-7) were obtained in the same manner as in (A-1), except that the raw materials were changed to the formulations (parts by mass) listed in Table 1.

[0072] [Table 1]

[0073] Details of Table 1 are shown below. Dicyclohexylmethane 4,4'-Diisocyanate (Desmodule W, manufactured by Sumika Covestro Urethane Co., Ltd.) Hexamethylene diisocyanate trimer (Sumijule N3390, manufactured by Sumika Covestro Urethane Co., Ltd.) PTMG250: Polytetramethylene ether glycol (PTMG250 manufactured by Mitsubishi Chemical Corporation) PTMG1000: Polytetramethylene ether glycol (PTMG1000 manufactured by Mitsubishi Chemical Corporation) PTMG2000: Polytetramethylene ether glycol (PTMG2000 manufactured by Mitsubishi Chemical Corporation) PTMG3000: Polytetramethylene ether glycol (PTMG3000 manufactured by Mitsubishi Chemical Corporation) PTMG4000: Polytetramethylene ether glycol (PTMG4000 manufactured by Mitsubishi Chemical Corporation) Polybutadiene with hydroxyl groups at both ends (NISSO-PBG-1000, manufactured by Nippon Soda Co., Ltd.) 2-Hydroxyethyl acrylate (Hydroxyethyl acrylate manufactured by Osaka Organic Chemical Industry Co., Ltd.)

[0074] <Manufacturing of Activated Energy Ray Curable Compositions and Coating Layers> (Example 1) A composition curable by active energy rays was obtained by mixing 34 parts of polyfunctional urethane (meth)acrylate (A-1), 10 parts of 4-HBA, 50 parts of ART PEARL C-80T, 4 parts of the photopolymerization initiator Omnirad 1173, and 2 parts of a silicone-based defoamer, and stirring with a bladed stirrer for 90 minutes. Next, using a screen (150 mesh / inch, polyester resin fiber, mesh opening 109 μm, wire diameter 48 μm, emulsion thickness 20 μm, transmission area 75 mm × 50 mm, theoretical coating thickness 30 μm), the active energy ray curable composition was applied onto an easily adhering PET substrate (Cosmoshine A4160, manufactured by Toyobo Co., Ltd.), and cured with a UV lamp to form a coating layer, thereby obtaining a laminate consisting of a substrate and a coating layer. The UV lamp used was a high-pressure mercury lamp, and the UV lamp intensity was set to 80 W / cm (cumulative light intensity 400 mJ / cm). 2 ). Furthermore, the active energy ray-curable composition was coated onto a release PET substrate (Cosmopeel E7006, manufactured by Toyobo Co., Ltd.) using a 4 mil applicator and cured under the same conditions as described above. Subsequently, a cured film was obtained by peeling off only the coating layer from the release PET substrate. This cured film was used to measure the storage modulus (Er) based on the method described above.

[0075] (Examples 2-20, Comparative Examples 1-5) An active energy ray curable composition, a laminate produced using the same, and a cured film were obtained in the same manner as in Example 1, except that the raw materials were changed to the formulation (parts by mass) shown in Table 2. In the case of Comparative Example 1, the evaluation was discontinued because it solidified immediately after mixing.

[0076] [Table 2]

[0077] Details of Table 2 are shown below. 4-HBA: 4-Hydroxybutyl acrylate (4-Hydroxybutyl acrylate manufactured by Osaka Organic Chemical Industry Co., Ltd.) 2-HEA: 2-Hydroxyethyl acrylate (Hydroxyethyl acrylate manufactured by Osaka Organic Chemical Industry Co., Ltd.) LA: Lauryl acrylate (Lauryl acrylate manufactured by Osaka Organic Chemical Industry Co., Ltd.) TEGDA: Tetraethylene glycol diacrylate (Tetraethylene glycol diacrylate manufactured by Osaka Organic Chemical Industry Co., Ltd.) ART PEARL C-80T (Polyurethane beads manufactured by Negami Kogyo Co., Ltd., median diameter 75 μm) ART PEARL SE-050T (Acrylic beads manufactured by Negami Kogyo Co., Ltd., median diameter 46μm) ART PEARL C-200T (Polyurethane beads manufactured by Negami Kogyo Co., Ltd., median diameter 32 μm) Viscopearl D-30 (Rengo cellulose beads, median diameter 40 μm) Excelica SE-40 (Tokuyama silica beads, median diameter 38 μm) ART PEARL MM-120T (Polyurethane beads manufactured by Negami Kogyo Co., Ltd., median diameter 2μm) Omnirad 1173 (2-hydroxy-2-methyl-1-phenylpropan-1-one, manufactured by IGM) Silicone-based defoaming agent (TEGO® Rad2500, manufactured by Evonik) PGM-AC (Propylene glycol monomethyl ether acetate, manufactured by Toyo Petrochemical Co., Ltd.)

[0078] <Rating> The laminates obtained in the examples and comparative examples were evaluated for their printed appearance, tactile feel (roughness), and abrasion resistance as described below. The evaluation results are shown in Table 2.

[0079] [Printed appearance] For the laminates obtained in the examples and comparative examples, the 75 mm x 50 mm area occupied by the coating layer was visually observed and the printed appearance was evaluated. The evaluation was performed according to the following criteria. A: The entire surface is uniform and without any unevenness (very good). B: There is some unevenness in one area (good) C: There are inconsistencies in two places (usable). D: There are three or more areas with unevenness (unusable).

[0080] [Texture (roughness)] A questionnaire survey regarding the roughness of the laminates obtained in the examples and comparative examples was conducted with 20 subjects. Subjects were asked to actually touch the coating layer with their fingers and evaluate it according to the following criteria. After compiling the results, the most frequent response was used as the evaluation result. A: I feel a strong sense of roughness (very good) B: Slightly rough feel (good) C: Not rough enough (usable) D: Does not feel rough (smooth, slimy, etc.) (Not usable)

[0081] [Abrasion resistance] The abrasion resistance of the laminates obtained in the examples and comparative examples was evaluated using an abrasion tester (ZJ-339-GSR, manufactured by Shenzhen Z.Jia Instrument Equipment). Measurements were performed using samples cut from two locations on the same laminate, with the coating layers overlapping surface-to-surface. Under conditions of a load of 1 kg, a speed of 60 reciprocations / min, and a travel distance of 60 mm, the appearance change was evaluated by the presence or absence of white dots and white lines on the surface of the coating layer after 300 reciprocations, indicating particle abrasion. The evaluation was performed according to the following criteria. A: There was no change in appearance before and after the test (very good). B: Some white spots appeared after the test (good). C: Some white spots and lines appeared after testing (usable). D: White spots and lines appeared across the entire surface after testing, or embedded or missing particles were observed (unusable).

[0082] According to the evaluation results, the active energy ray curable composition of the present invention has a good tactile feel (roughness / graininess), as well as excellent abrasion resistance and print appearance. In particular, Examples 2 and 9, in which the median diameter of the fine particles (C) was 40-60 μm, formed a structure in which some of the fine particles (C) protruded from the printed surface more easily than Examples 8 and 10, in which the same value was less than 40 μm, resulting in a superior tactile feel (roughness). Furthermore, Examples 2 and 9 had a higher transfer rate of fine particles (C) than Example 1, in which the same value was greater than 60 μm, resulting in a superior printed appearance. Furthermore, Example 2, in which the concentration of fine particles (C) in the composition was 30-60%, formed a structure in which some of the fine particles (C) protruded from the printed surface more easily than Examples 3, 4, and 5, in which the same value was less than 30%, resulting in a superior tactile feel (roughness). Furthermore, Example 2, in which the storage modulus (Er) of the cured film of the composition was 300-800 MPa at 25°C, suppressed the sinking of fine particles (C) into the cured film under load more effectively than Examples 6, 7, 15, 16, and 18, in which the same value was below 300 MPa, resulting in superior tactile feel (roughness). In addition, the contact area with the fine particles (C) was reduced, resulting in superior abrasion resistance. Furthermore, Example 2, in which the weight-average molecular weight of urethane acrylate (A) was 2000-3000, showed lower composition viscosity and superior print appearance compared to Examples 11, 13, and 14, in which the same value was greater than 3000. Furthermore, Example 2, which contained only a monofunctional ethylenically unsaturated monomer (B) as the ethylenically unsaturated monomer, showed better dispersibility of fine particles (C) and superior print appearance compared to Example 19, which contained a monofunctional ethylenically unsaturated monomer. Furthermore, the same effect as described above can be observed even when the printed layer is located between the substrate layer and the coating layer.

Claims

1. An active energy ray curable composition comprising a polyfunctional urethane (meth)acrylate (A), a monofunctional ethylenically unsaturated monomer (B), and fine particles (C), The median diameter (D50) of the aforementioned fine particles (C) is 30 μm or more. An active energy ray curable composition wherein the monofunctional ethylenically unsaturated monomer (B) contains a hydroxyalkyl (meth)acrylate.

2. The active energy ray curable composition according to claim 1, wherein the weight-average molecular weight of the polyfunctional urethane (meth)acrylate (A) is 1,000 to 7,000.

3. The active energy ray curable composition according to claim 1 or 2, wherein it does not contain an organic solvent, or the content of an organic solvent is 5% by mass or less of the total mass of the active energy ray curable composition.

4. The active energy ray curable composition according to claim 1 or 2, comprising a photopolymerization initiator.

5. The active energy ray curable composition according to claim 1 or 2, wherein the polyfunctional urethane (meth)acrylate (A) has constituent units derived from polyether.

6. The active energy ray curable composition according to claim 1 or 2, wherein the storage modulus (Er) of the cured film, which is cured using active energy rays, at 25°C is 50 MPa or more.

7. The active energy ray curable composition according to claim 6, wherein the storage modulus (Er) is 100 MPa or more.

8. The active energy ray curable composition according to claim 1 or 2, wherein the median diameter (D50) of the fine particles (C) is 40 to 60 μm.

9. A coating composition comprising the active energy ray curable composition according to claim 1 or 2.

10. It has a base layer and a coating layer, A laminate in which the coating layer is formed from the coating composition described in claim 9.

11. The laminate according to claim 10, wherein the thickness of the coating layer is smaller than the median diameter (D50) of the fine particles (C).

12. The laminate according to claim 10, further comprising a printed layer between the substrate layer and the coating layer.

13. A method for manufacturing a laminate having a base layer and a coating layer, A method for manufacturing a laminate, comprising the step of applying the coating composition according to claim 9 onto a substrate by screen printing.

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