Active energy ray-curable screen printing ink, printed article, and method for producing a molded printed article

Abstract

To provide: an active energy ray-curable screen printing ink which has good adhesion relative to a plastic substrate, has excellent chemical resistance, post-processability and flexibility of a cured coating film, and whose ratio having biomass-derived ingredient in the ink is 10 mass% or more; and a printing body.SOLUTION: An active energy ray-curable screen printing ink contains a coloring agent, a binder resin containing a botanical ingredient modified acrylate, and a biomass resin particle. The botanical ingredient modified acrylate contains rosin-modified polyester acrylate and / or a vegetable oil modified polyepoxy-acylate.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an active energy ray-curable screen printing ink and a printed article using the same. In particular, it relates to an active energy ray-curable screen printing ink having good adhesion to a plastic substrate, excellent chemical resistance, post-processing properties, flexibility of a cured coating film, and having a ratio of biomass-derived components in the ink of 10% by mass or more, and a printed article using the same.

Background Art

[0002] Conventionally, active energy ray-curable screen printing inks can be cured by irradiating active energy rays such as ultraviolet rays, visible light rays, and electron beams for a very short time, have high productivity, and can obtain high coating film resistance, so they are widely used in fields where durability is required.

[0003] When the printing target substrate of this active energy ray-curable screen printing ink is a plastic substrate, there are problems such as poor adhesion can be obtained for plastics such as olefin-based substrates with low polarity such as polyethylene and polypropylene, and polyethylene substrates, and there are required physical properties such as chemical resistance, flexibility, and post-processing suitability as coating film properties, and various studies have been conducted.

[0004] On the other hand, in recent years, as an effort to reduce the environmental load, due to the newly established biomass mark system by the Japan Organic Resources Association, it is required to replace the raw materials contained in the ink with biomass-derived raw materials and increase the ratio thereof. However, in active energy ray-curable inks, there has been a problem that when the ratio of biomass-derived raw materials is increased, various physical properties such as sufficient adhesion to the substrate and coating film resistance cannot be obtained.

[0005] For example, Patent Document 1 discloses an active energy ray-curable resin composition containing 5 to 95% by weight of rosin epoxy acrylate, 5 to 95% by weight of a polyurethane resin having a carbon-carbon unsaturated bond group and a number average molecular weight of 1,000 to 50,000, and 0 to 70% by weight of a reactive diluent. However, although using rosin epoxy acrylate increases the biomass ratio, the adhesion to the plastic substrate was not sufficient. Furthermore, since both rosin epoxy acrylate and the polyurethane resin are monofunctional, there were problems with the coating film resistance.

[0006] Also, for example, Patent Document 2 discloses an active energy ray-curable resin composition containing a monofunctional polyether-based polymerizable oligomer. However, by using a monofunctional oligomer having a flexible polyether structure, the adhesion to the polyethylene terephthalate substrate is improved, but there are problems with the adhesion to the polystyrene substrate. In addition, since biomass-derived raw materials are not used, it can be said that environmental compatibility is not sufficient.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0008] The present invention provides an active energy ray-curable screen printing ink and a printed article that have good adhesion to a plastic substrate, are excellent in chemical resistance, post-processing properties, and flexibility of the cured coating film, and have a ratio of biomass-derived components in the ink of 10% by mass or more.

Means for Solving the Problems

[0009] As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by the active energy ray-curable screen printing ink and printed matter shown below, and have completed the present invention.

[0010] That is, the present invention relates to an active energy ray-curable screen printing ink containing a colorant, a binder resin containing a plant component-modified acrylate, and resin particles.

[0011] The present invention also relates to the above active energy ray-curable screen printing ink, wherein the plant component-modified acrylate contains rosin-modified polyester acrylate and / or vegetable oil-modified polyepoxy acrylate.

[0012] The present invention also relates to the above active energy ray-curable screen printing ink, wherein the content of the plant component-modified acrylate is 5 to 30% by mass based on the total mass of the active energy ray-curable screen printing ink.

[0013] The present invention also relates to the above active energy ray-curable screen printing ink, wherein the binder resin further contains urethane acrylate.

[0014] The present invention also relates to the above active energy ray-curable screen printing ink, wherein the glass transition temperature of the cured product of urethane acrylate alone is -50 to 50°C.

[0015] The present invention also relates to the above active energy ray-curable screen printing ink, wherein the resin particles are biomass resin particles.

[0016] The present invention also relates to the above active energy ray-curable screen printing ink, which further contains 0.1 to 5% by mass of an antifoaming agent that is a non-silicone-based compound in the total amount of the ink.

[0017] The present invention also relates to a printed matter having a cured printing layer made of the above active energy ray-curable screen printing ink on a substrate.

[0018] The present invention also relates to the printed matter described above, wherein the base material is a molded plastic.

[0019] The present invention also relates to a method for manufacturing a molded printed matter, which includes a step of printing the above active energy ray curable screen printing ink on a molded plastic.

Effects of the Invention

[0020] According to the present invention, it has become possible to provide an active energy ray curable screen printing ink and a printed matter that have good adhesion to a plastic substrate, are excellent in chemical resistance, post-processing properties, and flexibility of a cured coating film, and have a ratio of biomass-derived components in the ink of 10% by mass or more.

Modes for Carrying Out the Invention

[0021] Hereinafter, the constituent elements of the present invention will be described in detail. However, the following description is a part of the embodiments of the present invention and is not limited thereto. Further, unless otherwise specified, "part" represents "part by mass" and "%" represents "% by mass".

[0022] In the following description, "(meth)acryl" represents "acryl and / or methacryl", and "(meth)acrylate" represents "methacrylate and / or acrylate". "(meth)acryloyl" represents "methacryloyl and / or acryloyl". In the following description, a polymerizable oligomer refers to a compound having a polymerizable group and a molecular weight of 1,000 or more, and a polymerizable monomer refers to a compound having a polymerizable group and a molecular weight of less than 1,000. The polymerizable group refers to an acrylate group, a methacrylate group, or other polymerizable unsaturated double bond groups.

[0023] [Active Energy Ray Curable Screen Printing Ink] The active energy ray curable screen printing ink of the present invention is characterized by containing a colorant, a binder resin containing a plant component-modified acrylate, and resin particles. By including a plant component-modified acrylate in the binder resin, the pigment dispersibility, coating film flexibility, and biomass content are improved. By including resin particles, the printability and coating film flexibility are improved. Preferably, by including biomass resin particles, the biomass content is improved.

[0024] Hereinafter, components and the like that are included in or can be included in the active energy ray-curable screen printing ink of the present embodiment (hereinafter, may also be simply referred to as "screen ink" or "ink") will be described.

[0025] [Colorant] The active energy ray-curable screen printing ink of the present invention contains a colorant. As the colorant, at least one of a pigment and a dye can be used. From the viewpoint of light resistance, a pigment is preferable. There is no particular limitation on the pigment that can be used in the present invention, and known pigments can be used. Either inorganic pigments or organic pigments can be used as the pigment.

[0026] Examples of the inorganic pigments include carbon blacks such as furnace black, lamp black, acetylene black, and channel black, iron oxide, titanium oxide, and the like.

[0027] Examples of the above-mentioned organic pigments include soluble azo pigments such as β-naphthol-based, β-oxynaphthoic acid-based, β-oxynaphthoic acid anilide-based, acetoacetic acid anilide-based, and pyrazolone-based pigments; insoluble azo pigments such as β-naphthol-based, β-oxynaphthoic acid anilide-based, acetoacetic acid anilide-based monoazo, acetoacetic acid anilide-based disazo, and pyrazolone-based pigments; phthalocyanine-based pigments such as copper phthalocyanine blue, halogenated (e.g., chlorinated or brominated) copper phthalocyanine blue, sulfonated copper phthalocyanine blue, and metal-free phthalocyanine; polycyclic and heterocyclic pigments such as quinacridone-based, dioxazine-based, threne-based (such as pyranthrone, anthraanthrone, indanthrone, anthrapyrimidine, flavanthrone, thioindigo-based, anthraquinone-based, perinone-based, perylene-based, etc.), isoindolinone-based, metal complex-based, quinophthalone-based, diketopyrrolopyrrole-based pigments, etc.

[0028] More specifically, as shown in the C.I. Color Index, examples of black pigments include C.I. Pigment Black 1, 6, 7, 9, 10, 11, 28, 26, 31, etc.

[0029] Examples of white pigments include C.I. Pigment White 5, 6, 7, 12, 28, etc.

[0030] Examples of yellow pigments include C.I. Pigment Yellow 1, 2, 3, 12, 13, 14, 16, 17, 18, 24, 73, 74, 75, 83, 93, 95, 97, 98, 100, 108, 109, 110, 114, 120, 128, 129, 138, 139, 174, 150, 151, 154, 155, 167, 180, 185, 213, etc.

[0031] Examples of blue or cyan pigments include C.I. Pigment Blue 1, 2, 14, 15, 15:1, 15:2, 15:3, 15:4, 60, 62, etc.

[0032] Examples of red or pink pigments include C.I.Pigment RED 1, 3, 5, 19, 21, 22, 31, 38, 42, 43, 48:1, 48:2, 48:3, 48:4, 48:5, 49:1, 50, 52, 53:1, 57:1, 57:2, 58:4, 63:1, 81, 81:1, 81:2, 81:3, 81:4, 83, 90, 104, 108, 112, 114, 122, 144, 146, 148, 149, 150, 166, 168, 169, 170, 172, 173, 176, 177, 178, 184, 185, 187, 193, 202, 209, 214, 242, 254, 255, 264, 266, 269, C.I.Pigment Violet 19, etc.

[0033] Examples of green pigments include C.I.Pigment Green 1, 2, 3, 4, 7, 8, 10, 15, 17, 26, 36, 45, 50, etc.

[0034] Examples of purple pigments include C.I.Pigment Violet 1, 2, 3, 4, 5:1, 12, 13, 15, 16, 17, 19, 23, 25, 29, 31, 32, 36, 37, 39, 42, etc. Examples of orange pigments include C.I.Pigment Orange 13, 16, 20, 34, 36, 38, 39, 43, 51, 61, 63, 64, 74, etc.

[0035] In the present invention, the above pigments may be used alone or in combination of two or more.

[0036] In the present invention, the above pigments can be used in any content as long as the target density can be reproduced on the printing surface, and it is preferably 1 to 40% by mass, more preferably 5 to 30% by mass based on the total mass of the ink.

[0037] [Binder resin] In the present invention, the binder resin refers to a resin that can function as a binder in screen printing ink and includes plant component-modified acrylates. Many plant component-modified acrylates are binder resins corresponding to polymerizable oligomers.

[0038] [Plant component-modified acrylate] As the plant component-modified acrylate contained in the active energy ray-curable screen printing ink in the present invention, those having a (meth) acrylate group and modified with a plant component can be used without limitation. The plant component-modified acrylate can improve pigment dispersibility and coating film flexibility, and further increase the biomass content. Preferred examples of the plant component-modified acrylate include rosin-modified polyester acrylate and / or vegetable oil-modified polyepoxy acrylate, and vegetable oil-modified urethane acrylate.

[0039] [Rosin-modified polyester acrylate] In the rosin-modified polyester acrylate, the proportion of the structural unit derived from rosin (hereinafter also referred to as "rosin content") in the total mass of the rosin-modified polyester acrylate is preferably 40 to 80% by mass, and more preferably 40 to 60% by mass from the viewpoint of chemical resistance. The weight average molecular weight of the rosin-modified polyester acrylate is preferably 1,000 to 10,000, and more preferably 1,000 to 8,000. Further, the rosin-modified polyester acrylate preferably has 2 to 6 (meth) acryloyl groups, and more preferably 3 to 6 (meth) acryloyl groups.

[0040] The rosin-modified polyester acrylate can be obtained, for example, by subjecting a conjugated rosin acid and an ethylenically unsaturated double bond-containing compound having a carboxy group to a Diels-Alder addition reaction, and further subjecting the carboxy group of the reaction compound and the hydroxyl group of a polyol to an esterification reaction, and reacting the resulting rosin-modified polyester compound with a (meth)acrylate compound having a hydroxyl group, but is not limited thereto. Examples of the rosin-modified polyester acrylate include the "ETERCURE" series manufactured by Changxing Materials Industry Co., Ltd. and the "EBECRYL" series manufactured by Daicel Allnex Co., Ltd.

[0041] [Vegetable oil-modified polyepoxy acrylate] As the vegetable oil-modified polyepoxy acrylate, known compounds such as those obtained by adding (meth)acrylic acid to the epoxy group of an epoxidized vegetable oil obtained by epoxidizing the double bond of an unsaturated vegetable oil with peracetic acid or perbenzoic acid can be used. Preferred vegetable oils to be modified include soybean oil, rapeseed oil, sunflower oil, corn oil, etc. The vegetable oil-modified polyepoxy acrylate preferably has a content of a vegetable oil-derived structure of 40 to 80% by mass, more preferably 60 to 80% by mass. Further, the weight average molecular weight of the vegetable oil-modified polyepoxy acrylate is preferably 1,000 to 10,000, more preferably 1,000 to 8,000. Also, the vegetable oil-modified polyepoxy acrylate preferably has 2 to 5 (meth)acryloyl groups, and more preferably 2 to 4 (meth)acryloyl groups from the viewpoint of coating film flexibility. Examples of the vegetable oil-modified polyepoxy acrylate include the "PHOTOMER" series manufactured by IGM Resins and the "EBECRYL" series manufactured by Daicel Allnex.

[0042] [Urethane acrylate] In the screen ink of the present invention, the binder resin preferably further contains urethane acrylate. Note that many urethane acrylates correspond to polymerizable oligomers. Urethane acrylate has a (meth) acrylate group, and for example, it is obtained by reacting diisocyanate with (meth) acrylates having a hydroxyl group, or an isocyanate group-containing urethane prepolymer obtained by reacting a polyol and a polyisocyanate under conditions of an excess of isocyanate groups is reacted with (meth) acrylates having a hydroxyl group. Or it can also be obtained by reacting a hydroxyl group-containing urethane prepolymer obtained by reacting a polyol and a polyisocyanate under conditions of an excess of hydroxyl groups with (meth) acrylates having an isocyanate group. Note that urethane acrylate using a compound obtained by modifying a plant component such as a vegetable oil-modified diol as a raw material is treated as "plant component-modified acrylate". The weight average molecular weight of the urethane acrylate is preferably 1,000 to 50,000, and more preferably 1,000 to 30,000. Further, the urethane acrylate preferably has 2 to 5 (meth) acryloyl groups, and more preferably 2 to 4. Also, the glass transition temperature of the cured product of the urethane acrylate alone is preferably -50 to 50 ° C, and more preferably -40 to 40 ° C from the viewpoint of coating film performance with a balanced flexibility and chemical resistance. The method for measuring the glass transition temperature will be described later. Examples of the above urethane acrylate include the "Mitsubishi Chemical" series manufactured by Mitsubishi Chemical Corporation and the "AER RESIN" series manufactured by Negami Kogyo Co., Ltd.

[0043] In the present invention, the content of the above urethane acrylate is preferably 1 to 50% by mass, more preferably 10 to 30% by mass, based on the total mass of the screen ink.

[0044] Note that the mass ratio of the above plant component-modified acrylate to the above urethane acrylate is preferably 10:90 to 80:20, and still more preferably 30:70 to 80:20. Further, it is preferable that the total of the plant component-modified acrylate and the urethane acrylate is contained in an amount of 20 to 80% by mass, and still more preferably 20 to 60% by mass, based on the total mass of the screen ink.

[0045] [Resin particles] The resin particles used in the screen ink of the present invention exhibit effects on the coating film performance such as surface protection of the ink layer and chemical resistance, and there is no limitation as long as they are particles (which may be fine particles) made of resin. The resin particles are preferably biomass resin particles, and for example, preferably contain a compound of a natural product-based (including plant-based) system. Preferred examples of the structure of the biomass resin particles include resin particles containing polyhydroxyalkanoic acid (PHA) such as starch, cellulose, polylactic acid (PLA), polyglycolic acid (PGA), and polyhydroxybutyric acid (PHB). More preferably, they are resin particles containing polyhydroxyalkanoic acid (PHA). Further, biomass resin particles having a biomass degree exceeding 0% (preferably 10% or more, or 20% or more) and less than 100% using the above natural product-based (including plant-based) compound as a raw material can also be preferably used. The average particle diameter of the biomass resin particles is preferably 1 to 20 μm, still more preferably 1 to 15 μm, and even more preferably 2 to 12 μm. The average particle diameter refers to the measured value of D50 in the laser diffraction / scattering method. From the viewpoint of coating film performance, the melting point temperature is preferably 100°C or higher and 250°C or lower, or 120°C or higher and 220°C or lower. Examples of such resin particles include the "ARBOCEL" series manufactured by RETTENMAIER.

[0046] In the present invention, the above resin particles may be used alone or in combination of two or more.

[0047] In the present invention, the content of the resin particles is preferably 1 to 20% by mass, more preferably 1 to 10% by mass, based on the total mass of the ink.

[0048] [Polymerization initiator] The active energy ray-curable ink in the present invention preferably contains a polymerization initiator. As the polymerization initiator, it is preferably a polymerizable initiator for radical polymerization, and more preferably a photoinitiator. The polymerization initiator in the present invention is a compound that undergoes a chemical change through the action of light or interaction with the electronically excited state of a sensitizing dye, for example, generating radicals. Among them, from the viewpoint of being able to initiate polymerization by means of exposure, a photo radical polymerization initiator is preferably used. However, when the active energy ray is an electron beam or the like, a polymerization initiator may not be required.

[0049] In the present invention, the photo radical polymerization initiator is not particularly limited, and known ones can be used. Specific examples include benzophenone-based compounds, dialkoxyacetophenone-based compounds, α-hydroxyalkylphenone-based compounds, α-aminoalkylphenone-based compounds, acylphosphine oxide compounds, thioxanthone compounds, and the like.

[0050] Examples of the benzophenone-based compounds include benzophenone, 4-methylbenzophenone, 4-phenylbenzophenone, 4,4'-bis(diethylamino)benzophenone, 4,4'-bis(dimethylamino)benzophenone, [4-(methylphenylthio)phenyl]-phenylmethanone, and the like.

[0051] Examples of the dialkoxyacetophenone-based compounds include 2,2-dimethoxy-2-phenylacetophenone, dimethoxyacetophenone, diethoxyacetophenone, and the like.

[0052] Examples of the above α-hydroxyalkylphenone compounds include 1-hydroxy-cyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-[4-(2-hydroxy-methoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one, and the like.

[0053] Examples of the above α-aminoalkylphenone compounds include 2-methyl-1-[4-(methoxy-thio)-phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl-1-butanone, and the like.

[0054] Examples of the above acylphosphine oxide compounds include diphenylacylphenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and the like.

[0055] Examples of the above thioxanthone compounds include 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, and the like.

[0056] In the present invention, the above polymerization initiator may be used alone or in combination of two or more.

[0057] In the present invention, the content of the above polymerization initiator is preferably 0.5 to 20% by mass, more preferably 1 to 10% by mass, based on the total mass of the ink.

[0058] [Polymerizable monomer] The screen ink of the present invention preferably contains a polymerizable monomer in addition to the above. In the present invention, the "polymerizable monomer" refers to a polymerizable monomer having a molecular weight of less than 1000 (except for plant component-modified acrylates and urethane acrylates). Hereinafter, it is also simply referred to as "monomer". The monomer is preferably a compound having a polymerizable group selected from (meth)acryloyl group, allyl group, vinyl group, and vinyl ether group in the molecule. Among them, an acrylate monomer which is a compound having a (meth)acryloyl group as the polymerizable group is more preferable. Specific examples of the above monomer include 2-ethylhexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, β-carboxyethyl (meth)acrylate, 4-tert-butylcyclohexanol (meth)acrylate, tetrahydrofurfuryl acrylate, alkoxylated tetrahydrofurfuryl acrylate, caprolactone (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, isoamyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, isodecyl (meth)acrylate, 3,3,5-trimethylcyclohexanol (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, norbornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (oxyethyl)(meth)acrylate, 1,4-cyclohexanedimethanol (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, benzyl (meth)acrylate, EO-modified (2) nonylphenol acrylate, 2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl acrylate, acryloylmorpholine and other monofunctional (meth)acrylate monomers having one (meth)acryloyl group in the molecule, and monofunctional monomers such as N-vinylcarbazole, 1-vinylimidazole, N-vinyl-2-pyrrolidone, N-vinylcaprolactam, N-vinylformamide and other monofunctional vinyl monomers having one vinyl group in the molecule are suitable. 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, polyethylene glycol (600) di(meth)acrylate, neopentyl glycol hydroxypivalate di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, EO-modified (2) 1,6-hexanediol di(meth)acrylate, PO-modified (2) neopentyl glycol di(meth)acrylate, (neopentyl glycol-modified) trimethylolpropane di(meth)acrylate, dimethyloltricyclodecane di(meth)acrylate, EO-modified (4) bisphenol A di(meth)acrylate, PO-modified (4) bisphenol A di(meth)acrylate, cyclohexanedimethanol di(meth)acrylate, dimethylol-tricyclodecane di(meth)acrylate, dicyclopentanyl di(meth)acrylate and other difunctional (meth)acrylate monomers having two (meth)acryloyl groups in the molecule, etc. Difunctional monomers are preferred. Trimethylolpropane tri(meth)acrylate, EO-modified (3) trimethylolpropane tri(meth)acrylate, PO-modified (3) trimethylolpropane tri(meth)acrylate, ε-caprolactone-modified tris-(2-acryloxyethyl) isocyanurate, ethoxylated isocyanuric acid tri(meth)acrylate, tris(2-hydroxyethyl) isocyanurate tri(meth)acrylate, pentaerythritol tri(meth)acrylate and other trifunctional (meth)acrylate monomers having three (meth)acryloyl groups in the molecule Tetrafunctional (meth)acrylate monomers having four acryloyl groups in the molecule, such as pentaerythritol tetra(meth)acrylate and ditrimethylolpropane tetra(meth)acrylate, Pentafunctional (meth)acrylate monomers having five (meth)acryloyl groups in the molecule, such as dipentaerythritol penta(meth)acrylate, Hexafunctional (meth)acrylate monomers having six (meth)acryloyl groups in the molecule, such as dipentaerythritol hexa(meth)acrylate, and the like.

[0059] Among these monomers, from the viewpoints of flexibility and adhesion, it is preferably to contain bifunctional monomers and / or monofunctional monomers, and more preferably to contain bifunctional monomers and monofunctional monomers. The form in which the bifunctional monomers and the monofunctional monomers are contained in a mass ratio of 10:90 to 80:20, preferably 10:90 to 70:30 may be sufficient.

[0060] When containing monofunctional monomers, from the viewpoint of chemical resistance, it is preferably 30% by mass or less, and more preferably 20% by mass or less with respect to the total mass of the active energy ray-curable screen printing ink. Further, when containing (meth)acrylate monomers having three or more functional groups, from the viewpoint of flexibility, it is preferably 30% by mass or less, and more preferably 20% by mass or less with respect to the total mass of the active energy ray-curable screen printing ink.

[0061] In addition, in screen ink, in order to improve chemical resistance, flexibility, and adhesion, the mass ratio of the polymerizable oligomer to the polymerizable monomer is preferably 5:95 to 95:5. It is still more preferably 30:70 to 95:5.

[0062] [Polymerizable oligomers other than plant component-modified acrylates and urethane acrylates (other polymerizable oligomers)] The present invention preferably also contains a polymerizable oligomer other than plant component-modified acrylate and urethane acrylate. The polymerizable oligomer may be a compound having a polymerizable group such as an allyl group, a vinyl group, a vinyl ether group, an internal double bond group (such as maleic acid), etc. in the molecule, not only acrylate groups. Examples of other polymerizable oligomers include acrylic acrylate, polyester acrylate, polyepoxy acrylate, etc. derived from petroleum. From the viewpoint of abrasion resistance, polyepoxy acrylate is preferred, and polyepoxy acrylate having a bisphenol A structure is more preferred. Also, the polymerizable oligomer may be used alone or in combination of two or more.

[0063] Other polymerizable oligomers preferably have a (meth)acryloyl group as a polymerizable group in one molecule. In that case, from the viewpoint of flexibility, the number of (meth)acryloyl groups per molecule is preferably 1 to 6, more preferably 2 to 4. The weight average molecular weight of other polymerizable oligomers is preferably 1,000 to 50,000, more preferably 1,000 to 30,000.

[0064] In the present invention, the "weight average molecular weight" can be determined as a styrene-equivalent molecular weight by general gel permeation chromatography (hereinafter, GPC). The measurement method of GPC is as follows. Using HLC-8020 manufactured by Tosoh Corporation, the calibration curve was prepared with a standard polystyrene sample. The eluent was tetrahydrofuran, and three TSKgel SuperHM-M (manufactured by Tosoh Corporation) columns were used. For the measurement, a flow rate of 0.6 ml / min, an injection volume of 10 μl, a column temperature of 40°C, etc. can be adopted.

[0065] [Antifoaming agent] The screen printing ink of the present invention preferably contains an antifoaming agent. The content is preferably 0.1 to 5% by mass in the total mass of the screen ink. As the compound constituting the antifoaming agent, at least one antifoaming agent selected from acrylic resins, vinyl ether resins, butadiene resins, silicone resins, fluorine-based resins, and modified resins thereof is preferably mentioned (however, the above binder resin is not included). The antifoaming agent is preferably a non-silicone resin, and preferably contains at least one resin selected from acrylic resins, vinyl ether resins, and butadiene resins. For example, commercially available such antifoaming agents include BYK series (manufactured by Big Chemie Japan) and Floren series (manufactured by Kyoeisha Chemical Co., Ltd.).

[0066] [Leveling agent] The screen printing ink of the present invention preferably further contains a leveling agent. The content is preferably 0.1 to 1% by mass in the total mass of the screen printing ink. The compound constituting the leveling agent is preferably an acrylic resin and / or a silicone resin (however, the above binder resin is not included). For example, commercially available such leveling agents include Polyflow series (manufactured by Kyoeisha Chemical Co., Ltd.). These may be used alone or in combination of two or more.

[0067] [Other components] The active energy ray-curable screen printing ink of the present invention can contain, as necessary and within a range where the effects of the present invention are not reduced, in addition to the above components, extender pigments, pigment dispersants, other polymerizable compounds, sensitizers, waxes, polymerization inhibitors, surface tension adjusters, antifoaming agents, ultraviolet absorbers, antioxidants, and the like.

[0068] [Pigment dispersant] In the present invention, the ink preferably contains a pigment dispersant in order to improve the pigment dispersibility. There is no particular limitation on the pigment dispersant, and known pigment dispersants can be used. Among them, resin-type pigment dispersants having basic functional groups are preferred, and examples of the basic functional groups include primary, secondary, or tertiary amino groups, and nitrogen-containing heterocycles such as pyridine, pyrimidine, and pyrazine. In addition, as the skeleton constituting the resin-type pigment dispersant, a fatty acid amine skeleton and / or a urethane skeleton are more preferred because good pigment dispersibility can be easily obtained.

[0069] Examples of the pigment dispersant include those available from Ajinomoto Fine-Techno Co., Ltd.'s Ajisper series (Ajisper PB821, PB822, PB824, etc.), Lubrizol Corporation's Solsperse series (Solsperse 24000, Solsperse 32000, Solsperse 38500, etc.), and BYK Chemie GmbH's Disperbyk series (BYK-162, BYK-168, BYK-183, etc.).

[0070] The content of the pigment dispersant is preferably 0.1 to 10% by mass, more preferably 0.5 to 5% by mass, based on the total mass of the ink.

[0071] [Sensitizer] In the present invention, the ink may also contain a sensitizer in order to improve the curability. There is no particular limitation on the sensitizer, and known sensitizers can be used. Specifically, triethanolamine, methyldiethanolamine, triisopropanolamine, aliphatic amines, ethyl 2-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, dibutylethanolamine, 4,4-bis(dimethylamino)benzophenone, and the like can be mentioned.

[0072] The content of the polymerization initiation auxiliary is preferably 0.1 to 5% by mass, more preferably 0.5 to 3% by mass, based on the total mass of the ink.

[0073] [Wax] In the present invention, the ink preferably contains wax in order to improve abrasion resistance, anti-blocking property, lubricity, and anti-slipping property. There is no particular limitation on the wax, and known waxes can be used. For example, there are natural waxes and synthetic waxes. Examples of natural waxes include carnauba wax, wood rosin, lanolin, montan wax, paraffin wax, microcrystalline wax, and the like. Examples of synthetic waxes include Fischer-Tropsch wax, polyethylene wax, polypropylene wax, polytetrafluoroethylene wax, polyamide wax silicone compounds, and the like.

[0074] The content of the wax is preferably 0.1 to 5% by mass based on the total mass of the ink.

[0075] [Polymerization inhibitor] In the present invention, the ink can use a polymerization inhibitor to enhance storage stability. As the polymerization inhibitor, hindered phenol-based compounds, phenothiazine-based compounds, hindered amine-based compounds, and phosphorus-based compounds are particularly preferably used. Specifically, 4-methoxyphenol, hydroquinone, methylhydroquinone, t-butylhydroquinone, 2,6-di-t-butyl-4-methylphenol, phenothiazine, aluminum salt of N-nitrosophenylhydroxylamine, and the like can be mentioned. Among them, it is preferably included a hindered phenol-based compound and / or a phenothiazine-based compound, and more preferably included 2,6-di-t-butyl-4-methylphenol and phenothiazine.

[0076] The content of the polymerization inhibitor is preferably 0.01 to 2% by mass based on the total mass of the ink from the viewpoint of enhancing storage stability while maintaining curability.

[0077] In the present invention, from the viewpoint of reducing environmental load, it is preferable that the ink substantially does not contain an organic solvent. "Substantially does not contain" means that in the case of a small amount of organic solvent accidentally mixed, it corresponds to "substantially does not contain". When containing a small amount of organic solvent, it is less than 3% by mass, more preferably less than 1% by mass, based on the total mass of the screen ink.

[0078] [Degree of biomass] The degree of biomass can be calculated by the following formula. Degree of biomass (%) = (mass of biomass component of plant component-modified acrylate used + mass of biomass component of biomass resin particles used) × 100 / total mass of active energy ray-curable screen printing ink The degree of biomass is preferably 10% or more. In the present invention, the means for achieving a biomass degree of 10% by mass or more is not particularly limited to the use of the above-mentioned predetermined compound, and methods such as addition of known biomass compounds can be appropriately used.

[0079] [Manufacture of screen printing ink] The screen printing ink of the present invention can be produced by an appropriately known dispersion method. For example, a required amount of a binder resin, pigment, organic solvent, and additive are mixed and well stirred with a stirrer or the like, and then it can be produced by a disperser such as a three-roll mill, a paint shaker, an attritor, or a sand mill. Among them, production by a three-roll mill is preferable.

[0080] [Substrate] The substrate used for forming the printed body in the present invention is not particularly limited, and examples thereof include inorganic substrates such as glass, polyester substrates such as polyethylene terephthalate, polyolefin substrates such as polyethylene, polypropylene, ethylene-vinyl acetate, and others, nylon substrates such as polyamide, acrylic substrates, polyvinyl chloride substrates, polycarbonate substrates, polyurethane substrates, and resin substrates such as epoxy substrates. Further, a vapor-deposited substrate obtained by vapor-depositing an inorganic compound such as silica, alumina, or aluminum on the substrate can also be used, and the vapor-deposited surface may be subjected to a coating treatment with polyvinyl alcohol or the like. Further, corona treatment, frame treatment, or stretching treatment may be performed. Among them, good adhesion can be obtained with respect to the molded plastic.

[0081] [Molded plastic substrate] The molding process for the molded plastic substrate in the present invention is not particularly limited, and known molding processes can be used. Examples include injection molding, direct blow molding, injection blow molding, insert molding, and the like.

[0082] [Printed body] The printed body of the present invention refers to a printed body in which a printing layer is formed on the above-mentioned substrate by a screen printing method using the above-mentioned screen ink and the printing layer is cured by active energy rays. The printing method is a screen printing method, and it is preferable that a cylinder press printing machine or a semi-automatic printing machine is used as the printing machine, and resin materials such as nylon and polyester and resin materials such as stainless steel are used as the printing plate.

[0083] In the present invention, the method for curing the screen ink is not particularly limited as long as it is by active energy rays, and known methods can be used. Specifically, it can be cured by irradiating with α-rays, γ-rays, electron beams, X-rays, ultraviolet rays, visible light, infrared light, etc. Among them, ultraviolet rays and electron beams are preferred, and ultraviolet rays are more preferred. The peak wavelength of the ultraviolet rays is preferably 200 to 600 nm, and more preferably 350 to 420 nm.

[0084] The active energy ray source is not particularly limited, and known ones can be used. Specifically, examples include LEDs (light-emitting diodes) such as mercury lamps, xenon lamps, metal halide lamps, ultraviolet light-emitting diodes (UV-LEDs), ultraviolet laser diodes (UV-LDs), and gas and solid lasers.

[0085] [Glass transition temperature] The glass transition temperature (Tg) refers to the value obtained by DSC (differential scanning calorimetry). The measuring instrument used was DSC8231 manufactured by Rigaku Corporation. The measurement temperature range was -70 to 250 °C, the heating rate was 10 °C / min, and the midpoint between the endothermic start temperature and the end temperature based on the glass transition in the DSC curve was taken as the glass transition temperature. The glass transition temperature of the homopolymer of rosin-modified polyester acrylate and / or vegetable oil-modified polyepoxy acrylate, which is a plant component-modified acrylate, is preferably 0 to 100 °C, and still more preferably 0 to 70 °C. The glass transition temperature of the homopolymer of urethane acrylate is preferably -50 °C to 50 °C, and still more preferably -40 °C to 40 °C. Here, the homopolymer means a polymer obtained by homopolymerizing the raw polymerizable oligomer. Within the above range, it is because a coating film performance with a balanced flexibility and chemical resistance can be obtained.

Examples

[0086] Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited in any way by the following examples. In the present invention, unless otherwise specified, "parts" represents "parts by mass" and "%" represents "% by mass". Note that Example 3 is a reference example.

[0087] <Example 1>[Preparation of Active Energy Ray-Curable Screen Printing Ink S1] 15 parts of rosin-modified polyester acrylate (biomass content 30% by mass, "ETERCURE" manufactured by Changxing Materials Industry Co., Ltd., trifunctional with a weight average molecular weight of 2,000 to 3,000), 25 parts of urethane acrylate (Mitsubishi Chemical Corporation's Violet UV-3200B, glass transition temperature of the homopolymer -8°C, bifunctional with a weight average molecular weight of 10,000), 6 parts of biomass resin particles A (natural product-based resin particles containing polyhydroxyalkanoic acid, biomass content ratio 100% by mass, average particle diameter 5 μm, melting point 170°C) as biomass resin particles, 10 parts of N-vinylcaprolactam as a monomer, 10 parts of 1,6-hexanediol diacrylate, 3 parts of 2,4-diethylthioxanthone as a polymerization initiator, 3 parts of ethyl 2-dimethylaminobenzoate as a sensitizer, 2 parts of BYK-057 (butadiene copolymer, manufactured by BYK-Chemie Japan) as a non-silicone defoaming agent, 6 parts of a colorant (C.I. Pigment Blue 15:4), and 20 parts of an extender pigment (barium sulfate) were uniformly mixed using a mixer rotary stirrer and then passed through a three-roll mill twice to prepare screen printing ink (S1).

[0088] <Examples 2 to 17, Comparative Examples 1 to 6>[Preparation of Screen Printing Inks S2 to S17, T1 to T6] Screen printing inks shown in Tables 1 and 2 were prepared in the same manner as in Example 1. The abbreviations in the tables are shown below. Also, the numerical values in the tables represent "parts" unless otherwise specified, and blanks indicate that they were not used. Soybean oil-modified polyepoxy acrylate (manufactured by Daicel Ornex Co., Ltd., number of functional groups 4, weight average molecular weight 1200, glass transition temperature of the homopolymer 13°C, biomass content ratio 64% by mass) Purple Light UV-3000B (manufactured by Mitsubishi Chemical Corporation, bifunctional, urethane acrylate, glass transition temperature of the single cured product -39°C, weight average molecular weight 18,000) Purple Light UV-7000B (manufactured by Mitsubishi Chemical Corporation, bifunctional to trifunctional, urethane acrylate, glass transition temperature of the single cured product 52°C, weight average molecular weight 3,500) ART RESIN UN-6200 (manufactured by Negami Kogyo Co., Ltd., bifunctional, urethane acrylate, glass transition temperature of the single cured product -52°C, weight average molecular weight 6,500) EBECRYL 1830 (manufactured by Daicel Ornex Co., Ltd., hexafunctional, polyester acrylate, glass transition temperature of the single cured product 77°C, weight average molecular weight 1,000) Biomass resin particles B (plant-based, biomass content including polylactic acid 100% by mass, average particle diameter 3μm) Shin-Etsu silicone KF-96-1000CS: silicone-based defoaming agent (manufactured by Shin-Etsu Chemical Co., Ltd.)

[0089] <Printing with screen printing ink S1> Using molded plastic with frame treatment as the substrate, the above active energy ray-curable screen printing ink S1 was screen printed with a pattern using a screen printing plate (manufactured by NBC Mesh Tech Co., Ltd., L-SCREEN, 140-030 / 355PW) on this substrate. Then, the screen printing ink was cured with UV light (light source is a metal halide lamp) so that the conveyor speed was 10 m / min, 120 W / cm, and the irradiation distance was 15 mm, and test samples were created. A screen printed body was produced. In addition, the frame treatment can be performed by a conventionally known method. However, a burner with a flame power of 35 to 40 μA is used, the distance between the tip of the burner and the surface of the molded plastic is set to about 25 to 75 mm, and the surface of the molded plastic is uniformly heat-treated over 0.5 to 2.0 seconds. In addition, the surface of the molded plastic after the frame treatment ensured wettability suitable for printing treatment so that the surface tension was in the range of 40 to 60 mN / m.

[0090] <Examples 1 to 17, Comparative Examples 1 to 6>[Printing with Screen Printing Inks S1 to S15, T1 to T6] Printed articles were produced in the same manner as in Example 1, except that the screen printing ink used in Example 1 was changed to the screen printing inks described in Tables 1 and 2.

[0091] <Evaluation of Screen Printing Inks and Printed Articles Thereof> The following evaluations were performed on the screen printing inks and printed articles obtained in the above Examples and Comparative Examples. The evaluation results are shown in Tables 1 and 2.

[0092] [Chemical Resistance] Evaluation was performed using the printed articles obtained in Examples 1 to 17 and Comparative Examples 1 to 6. The printed surface was rubbed 100 times back and forth with a cotton swab containing 99.5% ethanol, and the number of times the substrate was exposed was evaluated. A (excellent): 100 times or more B (good): 50 times or more and less than 100 times C (poor): less than 50 times Note that the industrially applicable levels are A and B.

[0093] [Flexibility] Evaluation was performed using the printed articles obtained in Examples 1 to 17 and Comparative Examples 1 to 6. The printed surface was folded into a 180° mountain fold and visually inspected for the state of cracking of the printed surface when returned to its original state. The criteria for evaluating the results were as follows. A (excellent): less than 10% cracking of the coating film at the folding line, no whitening of the coating film B (good): 10% or more and less than 20% cracking of the coating film at the folding line, slightly whitened coating film C (poor): 20% or more cracking of the coating film at the folding line, pieces falling off Note that the industrially applicable levels are A and B.

[0094] [Adhesion] Evaluations were carried out using the printed bodies obtained in Examples 1 to 17 and Comparative Examples 1 to 6. An adhesive tape with a width of 12 mm (Nichiban cellophane tape) was attached to the printed surface, and the appearance state of the printed surface when this was rapidly peeled off was visually judged. The criteria for the evaluation results were as follows. A (excellent): The peeling of the ink film on the printed surface is less than 5%. B (good): The peeled area of the ink film is 5% or more and less than 20%. C (poor): The peeled area of the ink film is 20% or more. Note that the industrially applicable levels are A and B.

[0095] [Post-processing property] Evaluations were carried out using the printed bodies obtained in Examples 1 to 17 and Comparative Examples 1 to 6. In the following evaluation, the post-processing property refers to the transfer area ratio of the foil transferred per unit area by foil (vapor deposition foil manufactured by Murata Kinpaku Co., Ltd.) transfer. The criteria for the evaluation results were as follows. A (excellent): The transfer rate of the transferred foil is 90% by mass or more. B (good): The transfer rate of the transferred foil is 80% by mass or more and less than 90% by mass. C (poor): The transfer rate of the transferred foil is less than 80% by mass. Note that the industrially applicable levels are A and B.

[0096] According to the present invention, Examples S1 to S17 containing a colorant, a binder resin containing a plant component-modified acrylate, and resin particles are provided as an active energy ray-curable screen printing ink and a printed body excellent in chemical resistance, flexibility, adhesion, and post-processing property, which have been made to solve the above problems. In Comparative Examples T1, T4, and T5 excluding the plant component-modified acrylate, the flexibility and adhesion were poor, and in Comparative Examples T2, T3, and T6 excluding the biomass resin particles, the chemical resistance and adhesion were poor.

[0097]

Table 1

[0098]

Table 2

Claims

1. An active energy ray-curable screen printing ink containing a colorant, a binder resin containing a plant component-modified acrylate, and resin particles, wherein the resin particles include biomass resin particles, the biomass resin particles contain at least one selected from the group consisting of starch, cellulose, polylactic acid, polyglycolic acid, polyhydroxybutyric acid, and polyhydroxyalkanoic acid, and further includes an antifoaming agent which is a non-silicone-based compound. An active energy ray-curable screen printing ink.

2. The active energy ray-curable screen printing ink according to Claim 1, wherein the plant component-modified acrylate includes rosin-modified polyester acrylate and / or vegetable oil-modified polyepoxy acrylate.

3. The active energy ray-curable screen printing ink according to Claim 1 or 2, wherein the content of the plant component-modified acrylate is 5 to 30% by mass based on the total mass of the active energy ray-curable screen printing ink.

4. The active energy ray-curable screen printing ink according to any one of Claims 1 to 3, wherein the binder resin further includes urethane acrylate.

5. The active energy ray-curable screen printing ink according to Claim 4, wherein the glass transition temperature of the cured product of urethane acrylate alone is -50 to 50°C.

6. The active energy ray-curable screen printing ink according to any one of Claims 1 to 5, wherein the antifoaming agent which is a non-silicone-based compound is contained in the total amount of the ink in an amount of 0.1 to 5% by mass.

7. A printed body having a cured printing layer made of the active energy ray-curable screen printing ink according to any one of Claims 1 to 6 on a substrate.

8. The printed body according to Claim 7, wherein the substrate is a molded plastic.

9. A method for manufacturing a molded printed body, including a step of printing the active energy ray-curable screen printing ink according to any one of Claims 1 to 6 on a molded plastic.

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