Ink composition for shielding ultraviolet rays, and method for producing substrate having embossed surface using same

Abstract

The present invention addresses the problem of providing: an ultraviolet light-blocking ink composition for inkjet printing, which is capable of forming a printed layer that blocks ultraviolet light moderately; and a method for manufacturing a substrate having a desired embossed surface using the ink composition. As a solution, provided is an ink composition for blocking ultraviolet light for inkjet printing, which is characterized by containing 55.0 mass% or more of a photopolymerizable monomer, 3.0 mass% or more but less than 15.0 mass% of an ultraviolet light absorber, and 10.0 mass% or more but less than 30.0 mass% of a non-polymerizable material, the content ratio of the polyfunctional monomer in the photopolymerizable monomer is 50.0 mass% or more with respect to the photopolymerizable monomer.

Description

Technical Field

[0001] The present invention relates to an ink composition for forming a printed layer that shields ultraviolet rays (ultraviolet shielding ink composition), and a method for producing a substrate having an embossed surface using the composition. Background Art

[0002] There are known embossing methods for applying a concave-convex pattern to the surface of an article. For example, a method in which a UV curable resin composition applied to the surface of the object is irradiated with ultraviolet light via a transparent tape printed with UV blocking ink, so that only a portion of the UV curable resin composition is cured, thereby processing into an embossed shape (Patent Document 1); a method in which an ink mixed with a UV absorber is printed on a photocurable resin coating applied on a substrate, and the printed portion is concave by light irradiation, thereby processing into an embossed shape (Patent Document 2); a method in which a UV absorber is present on the pattern portion of the surface of the object, and a UV curable unsaturated polyester resin film is further applied, and then a portion of the resin film is cured by irradiation with ultraviolet light to process into a concave-convex shape (Patent Documents 3 and 4); a method in which a pattern surface printed with an ink containing a UV absorber is covered with a UV photosensitive curable resin film, and then the resin film is cured by irradiating with ultraviolet light, and a concave portion that matches the printed pattern is formed to process into an embossed shape (Patent Document 5), etc.

[0003] Furthermore, in recent years, digital embossing methods using inkjet printing technology have also been proposed. According to digital embossing, various embossed shapes can be produced simply and at low cost. For example, the desired shape can be read by a scanner and reproduced by inkjet printing, so that a variety of processed products can be produced in small batches.

[0004] As digital embossing processing methods, for example, the following methods have been proposed: a method in which droplets (3) composed of an acrylate compound are sprayed on a liquid layer (2) formed on the surface of a processing object (1) according to a digital template, and the surface of the processing object (1) is further shaped by UV curing the liquid layer (2) and the droplets (3) (Patent Document 6); a method in which a photopolymerizable resin film A is formed by coating the surface of an object, a liquid B containing a photo-crosslinkable monomer or oligomer is coated on a part of the surface of the resin film A, the resin film A and the liquid B are polymerized, and a part of the polymer of the liquid B and the cured product of the resin film A are removed mechanically to obtain a cured product of the resin film A having a three-dimensional structure (Patent Documents 7, 8); etc.

[0005] There is also known a method of protecting an image from light degradation by inkjet printing a protective liquid for protecting the image containing an ultraviolet absorber and a resin having film-forming ability on the image (Patent Document 9).

[0006] Patent Literature Patent Document 1: Japanese Patent Application Laid-Open No. 53-51253 Patent Document 2: Japanese Patent Application Laid-Open No. 48-4602 Patent Document 3: Japanese Patent Application Laid-Open No. 48-64163 Patent Document 4: Japanese Patent Application Laid-Open No. 50-3139 Patent Document 5: Japanese Patent Application Laid-Open No. 48-22143 Patent Document 6: European Patent No. 3109056 Patent Document 7: International Publication No. 2020 / 039361 Patent Document 8: International Publication No. 2018 / 069874 Patent Document 9: Japanese Patent Application Publication No. 2000-225695 Summary of the invention As described above, although there are proposed digital embossing methods including a step of mechanically removing a portion of the photocured resin layer (see Patent Documents 7 and 8), it is difficult to obtain the desired embossing shape by these methods. That is, the ink composition used for printing by shielding ultraviolet rays has the following problems: 1) the ultraviolet rays cannot be sufficiently shielded, resulting in the complete photocuring of the base layer composed of the photopolymerizable resin, and the base layer cannot be removed; 2) the ultraviolet rays are excessively shielded, resulting in the base layer composed of the photopolymerizable resin that should be photocured not being sufficiently cured and remaining in a liquid state, resulting in excessive removal of the base layer; 3) the ink composition does not have printing suitability for inkjet printing, so it is difficult to perform inkjet printing appropriately.

[0007] Therefore, the first object of the present invention is to provide an ultraviolet light-shielding ink composition that can be inkjet printed and can form a printed layer that can appropriately shield ultraviolet light. Furthermore, the object of the present invention is to provide a method for producing a substrate having a desired embossed surface using the ultraviolet light-shielding ink composition.

[0008] That is, the present invention relates to the ultraviolet light-shielding ink composition described below.

[0009] [1] An ultraviolet light-shielding ink composition for inkjet printing, characterized in that: The ink composition contains 55.0% by mass or more of a photopolymerizable monomer, 3.0% by mass or more and less than 15.0% by mass of an ultraviolet absorber, and 10.0% by mass or more and less than 30.0% by mass of a non-polymerizable material, The content ratio of the polyfunctional monomer in the photopolymerizable monomer is 50.0 mass % or more relative to the photopolymerizable monomer.

[0010] [2] The ultraviolet light-shielding ink composition according to [1] above, wherein the non-polymerizable material contains a non-polymerizable high molecular compound and a non-polymerizable low molecular compound.

[0011] [3] The ultraviolet light-shielding ink composition according to [1] or [2], which is used for inkjet printing on an uncured coating film containing a photopolymerizable compound.

[0012] [4] The ultraviolet light-shielding ink composition according to [3] above, wherein the coating film contains a photopolymerization initiator.

[0013] Furthermore, the present invention relates to a method for producing a substrate having an embossed surface as shown below.

[0014] [5] A method for producing a substrate having an embossed surface, characterized by comprising the following steps: A step A of inkjet printing the ultraviolet light-shielding ink composition described in [1] onto an uncured coating film containing a photopolymerizable compound applied on a substrate; Step B of irradiating the coating film printed with the ultraviolet light-shielding ink composition with ultraviolet rays; A step C of removing the coating film in the area printed with the ultraviolet light shielding ink composition.

[0015] [6] The manufacturing method according to [5] above, characterized in that the thickness of the coating film is 30 μm or more.

[0016] [7] The manufacturing method according to the above [5] or [6] is characterized in that the step C is a mechanical removal step.

[0017] The UV light-shielding ink composition of the present invention can be printed on a base layer (also called a coating film) composed of a photopolymerizable resin by inkjet printing; when ultraviolet rays are irradiated from the printed layer, the printed layer itself will polymerize and solidify, and at the same time, the printed layer can appropriately block the ultraviolet rays irradiated to the base layer, so that the base layer will not be completely cured, but will be cured in a semi-cured state (that is, it will not be completely photocured, but can be photocured to a degree that can be cured). On the other hand, since the base layer in the area not printed with the UV light-shielding ink composition will be completely photocured by irradiation with ultraviolet rays, a part of the base layer can be mechanically removed according to the difference in hardness of the base layer solidified material. As a result, it is easy to form a concave-convex pattern, so that the desired embossing process can be performed on the object. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a flow chart showing the manufacture of a substrate having an embossed surface.

[0019] Figure 2 This is a diagram (photograph) showing the obtained embossed shape. Figure 2 1 is an example of drawing the alphabetic character "S"; 2 is an example of drawing "A"; 3 is an example of drawing "K"; and 4 is an example of drawing "A".

[0020] Explanation of symbols 1-substrate; 2-1-coating film; 2-2-fully cured product of the coating film; 2-3-semi-cured product of the coating film; 3-1-ultraviolet shading ink composition; 3-2-cured product of the ultraviolet shading ink composition; 4-exposure machine; 5-brush; 6-arbitrary coating layer. DETAILED DESCRIPTION

[0021] [1. Ink composition for ultraviolet light shielding] The ultraviolet light-shielding ink composition of the present invention contains 1) a photopolymerizable monomer, 2) an ultraviolet absorber, and 3) a non-polymerizable material, and may further contain 4) other components.

[0022] The ultraviolet light-shielding ink composition of the present invention can be cured by polymerizing the photopolymerizable monomer by irradiating ultraviolet light after printing by the inkjet method, but the degree of curing is such that it can be removed mechanically. In addition, since the ultraviolet light-shielding ink composition of the present invention contains an ultraviolet absorber, it is possible to avoid excessive ultraviolet light irradiation to the base layer (bottom layer) in the printed layer area formed with the ultraviolet light-shielding ink composition. As a result, even if the bottom layer is composed of a photocurable resin, it will not be completely cured, and can be made into a semi-cured state to the extent that it can be removed mechanically.

[0023] [1-1. Photopolymerizable monomer] The photopolymerizable monomer contained in the UV light-shielding ink composition is preferably a monomer having photo-radical polymerizability or a monomer having photo-cationic polymerizability; more preferably, a monomer having photo-radical polymerizability. The UV light-shielding ink composition contains at least a multifunctional photopolymerizable monomer, and may also contain a combination of a multifunctional photopolymerizable monomer and a monofunctional photopolymerizable monomer.

[0024] [1-1-1. Polyfunctional photopolymerizable monomer (polyfunctional monomer)] The so-called multifunctional photopolymerizable monomer is a compound having two or more ethylenically unsaturated bonds. Examples of the multifunctional photopolymerizable monomer include the following multifunctional (meth)acrylate compounds or vinyl ether group-containing (meth)acrylate compounds.

[0025] The polyfunctional (meth)acrylate compound may be bifunctional or trifunctional or more. Examples of bifunctional (meth)acrylate compounds include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, butanediol di(meth)acrylate, pentanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, hydroxypivaloyl hydroxypivalate di(meth)acrylate, hydroxy Pivaloyl hydroxypivalate dicaprolactone di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,2-hexanediol di(meth)acrylate, 1,5-hexanediol di(meth)acrylate, 2,5-hexanediol di(meth)acrylate, 1,7-heptanediol di(meth)acrylate, 1,8-octanediol di(meth)acrylate, 1,2-octanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,2-decanediol di(meth)acrylate 、1,12-dodecanediol di(meth)acrylate, 1,2-dodecanediol di(meth)acrylate, 1,14-tetradecanediol di(meth)acrylate, 1,2-tetradecanediol di(meth)acrylate, 1,16-hexadecanediol di(meth)acrylate, 1,2-hexadecanediol di(meth)acrylate, 2-methyl-2,4-pentanediol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 2-methyl-2-propyl-1,3-propanediol di(meth)acrylate, 2,4-di Methyl-2,4-pentanediol di(meth)acrylate, 2,2-diethyl-1,3-propanediol di(meth)acrylate, 2,2,4-trimethyl-1,3-pentanediol di(meth)acrylate, dimethylol octane di(meth)acrylate, 2-ethyl-1,3-hexanediol di(meth)acrylate, 2,5-dimethyl-2,5-hexanediol di(meth)acrylate, 2-methyl-1,8-octanediol di(meth)acrylate, 2-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, 2,4-diethyl-1,5-Pentanediol di(meth)acrylate, tricyclodecane dimethylol di(meth)acrylate, tricyclodecane dimethylol dicaprolactone di(meth)acrylate, cyclohexanedimethanol di(meth)acrylate, dicyclopentyl di(meth)acrylate, bisphenol A tetraethylene oxide adduct di(meth)acrylate, bisphenol F tetraethylene oxide adduct di(meth)acrylate, bisphenol S tetraethylene oxide adduct di(meth)acrylate, hydrogenated bisphenol A tetraethylene oxide Adduct di(meth)acrylate, hydrogenated bisphenol F tetraethylene oxide adduct di(meth)acrylate, hydrogenated bisphenol A di(meth)acrylate, hydrogenated bisphenol F di(meth)acrylate, bisphenol A tetraethylene oxide adduct dicaprolactone di(meth)acrylate, bisphenol F tetraethylene oxide adduct dicaprolactone di(meth)acrylate, etc., di(meth)acrylates of polyols such as glycerol, pentaerythritol, diglycerol, ditrimethylolpropane and dipentaerythritol, etc.,

[0026] Examples of trifunctional (meth)acrylate compounds include glycerol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane tricaprolactone tri(meth)acrylate, trimethylolethane tri(meth)acrylate, trimethylolhexane tri(meth)acrylate, trimethyloloctane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and the like; and 3EO (ethylene oxide)-modified products, 6EO-modified products, and 9EO-modified products thereof (3EO-modified trimethylolpropane tri(meth)acrylate, 3EO-modified trimethylolethane tri(meth)acrylate, 3EO-modified trimethylolhexane tri(meth)acrylate, and the like).

[0027] Examples of tetrafunctional or higher-functional (meth)acrylate compounds include trimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol tetracaprolactone tetra(meth)acrylate, diglycerol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, ditrimethylolpropane tetracaprolactone tetra(meth)acrylate, ditrimethylolethane tetra(meth)acrylate, ditrimethylolbutane tetra(meth)acrylate, ditrimethylolhexane tetra(meth)acrylate, ditrimethyloloctane tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol hexa(meth)acrylate, tripentaerythritol hepta(meth)acrylate, tripentaerythritol octa(meth)acrylate, tripentaerythritol polyoxyalkylene hepta(meth)acrylate, and the like.

[0028] Examples of the (meth)acrylate compounds containing a vinyl ether group include: 2-vinyloxyethyl (meth)acrylate, 3-vinyloxypropyl (meth)acrylate, 1-methyl-2-vinyloxyethyl (meth)acrylate, 2-vinyloxypropyl (meth)acrylate, 4-vinyloxybutyl (meth)acrylate, 1-methyl-3-vinyloxypropyl (meth)acrylate, 1-vinyloxymethylpropyl (meth)acrylate, 2-methyl-3-vinyloxypropyl (meth)acrylate, 3-methyl-3-vinyloxypropyl (meth)acrylate, 1,1-dimethyl-2-vinyloxyethyl (meth)acrylate, 3-vinyloxybutyl (meth)acrylate, 1-methyl-2-vinyloxypropyl (meth)acrylate, 2-vinyloxybutyl (meth)acrylate, 4-vinyloxycyclohexyl (meth)acrylate, 5-vinyloxypentyl (meth)acrylate, 6-vinyloxyhexyl (meth)acrylate, and 1,1-dimethyl-2-vinyloxyethyl (meth)acrylate. 4-vinyloxymethylcyclohexylmethyl (meth)acrylate, 3-vinyloxymethylcyclohexylmethyl (meth)acrylate, 2-vinyloxymethylcyclohexylmethyl (meth)acrylate, p-vinyloxymethylphenylmethyl (meth)acrylate, m-vinyloxymethylphenylmethyl (meth)acrylate, o-vinyloxymethylphenylmethyl (meth)acrylate, 2-(vinyloxyisopropoxy)ethyl (meth)acrylate, 2-(vinyloxyethoxy)propyl (meth)acrylate, 2-(vinyloxyethoxy)isopropyl (meth)acrylate, 2-(vinyloxyisopropoxy)propyl (meth)acrylate, 2-(vinyloxyisopropoxy)isopropyl (meth)acrylate, 2-(vinyloxyethoxyethoxy)ethyl (meth)acrylate, 2-(vinyloxyethoxyisopropoxy)ethyl (meth)acrylate, 2-(vinyloxyisopropoxyethoxy)ethyl (meth)acrylate, 2-(vinyloxyisopropoxy)ethyl (meth)acrylate, 2-(vinyloxyisopropoxyisopropoxy)ethyl (meth)acrylate, and the like.

[0029] The polyfunctional photopolymerizable monomer contained in the UV light-shielding ink composition is preferably a monomer whose odor is suppressed. This is because the UV light-shielding ink composition becomes a semi-cured state by light irradiation and does not completely cure. Preferred examples of the polyfunctional photopolymerizable monomer include 1,6-hexanediol diacrylate (2-functional), neopentyl glycol PO-modified diacrylate (2-functional), ethylene oxide-modified trimethylolpropane triacrylate (3-functional), and the like.

[0030] [1-1-2. Monofunctional photopolymerizable monomer (monofunctional monomer)] Monofunctional photopolymerizable monomers include, for example, unsaturated carboxylic acid compounds, (meth)acrylate alkyl ester compounds, hydroxyl-containing (meth)acrylate compounds, halogen-containing (meth)acrylate compounds, ether-containing (meth)acrylate compounds, carboxyl-containing (meth)acrylate compounds, other (meth)acrylate compounds, styrene compounds, N-vinyl compounds, acrylate compounds, and other compounds having one ethylenically unsaturated bond.

[0031] Examples of the monofunctional unsaturated carboxylic acid-based compound include unsaturated carboxylic acids such as (meth)acrylic acid, itaconic acid, crotonic acid, isocrotonic acid, fumaric acid, and maleic acid, and salts thereof and anhydrides thereof.

[0032] Examples of monofunctional alkyl (meth)acrylate compounds include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl acrylate, amyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, isooctyl (meth)acrylate, lauryl (meth)acrylate, octadecyl (meth)acrylate, and (meth)acrylate. ) isooctadecyl (meth)acrylate, isodecyl (meth)acrylate, isomyristyl (meth)acrylate, dicyclopentyl (meth)acrylate, tridecyl (meth)acrylate, nonyl (meth)acrylate, hexadecyl (meth)acrylate, myristyl (meth)acrylate, isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, norbornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, 1-adamantyl (meth)acrylate, 3,5,5-trimethylcyclohexyl acrylate, 4-tert-butylcyclohexyl (meth)acrylate, etc.

[0033] Examples of monofunctional hydroxyl-containing (meth)acrylate compounds include: 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, hydroxypentyl (meth)acrylate, 2-hydroxy-3-methoxypropyl (meth)acrylate, 2-hydroxy-3-butoxypropyl (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. (Poly)alkylene glycol-modified (meth)acrylates such as 2-(meth)acrylate, 1,6-hexanediol mono(meth)acrylate, glycerol mono(meth)acrylate, 2-hydroxy-3-chloropropyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-hydroxy-3-allyloxypropyl (meth)acrylate, 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate, 2-ethylhexyl EO-modified (meth)acrylate, o-phenylphenol EO-modified acrylate, p-cumylphenol EO-modified (meth)acrylate, and nonylphenol EO-modified (meth)acrylate.

[0034] Examples of the monofunctional halogen-containing (meth)acrylate compounds include trifluoromethyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, 1H-hexafluoroisopropyl (meth)acrylate, 1H,1H,5H-octafluoropentyl (meth)acrylate, 1H,1H,2H,2H-heptadecafluorodecyl (meth)acrylate, 2,6-dibromo-4-butylphenyl (meth)acrylate, 2,4,6-tribromophenoxyethyl (meth)acrylate, 2,4,6-tribromophenol 3EO (ethylene oxide) addition (meth)acrylate, and the like.

[0035] Examples of monofunctional ether group-containing (meth)acrylate compounds include: 1,3-butylene glycol methyl ether (meth)acrylate, methoxytriethylene glycol (meth)acrylate, methoxydipropylene glycol (meth)acrylate, methoxytripropylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, ethylcarbitol (meth)acrylate, 2-ethylhexylcarbitol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, tolylpolyethylene glycol (meth)acrylate, (meth)acrylate ) 2-(vinyloxyethoxy)ethyl acrylate, phenoxyethyl (meth)acrylate, p-nonylphenoxyethyl (meth)acrylate, p-nonylphenoxypolyethylene glycol (meth)acrylate, glycidyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxy-polyethylene glycol (meth)acrylate, hexaethylene glycol monophenyl ether mono(meth)acrylate, diethylene glycol monobutyl ether acrylate, dipropylene glycol monomethyl ether (meth)acrylate, 3-methoxybutyl (meth)acrylate, methoxydiethylene glycol ( meth)acrylate, methoxypropylene glycol (meth)acrylate, methoxy polyethylene glycol (meth)acrylate (EO repeating unit number 400, 700, etc.), 2-(2-ethoxyethoxy)ethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 3-methoxybutyl acrylate, ethoxyethyl acrylate, ethoxyethoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, alkoxylated 2-phenoxyethyl (meth)acrylate (ethoxy Alkoxy and / or phenoxy (meth)acrylates such as ethoxylated 2-phenoxyethyl (meth)acrylate, propoxylated 2-phenoxyethyl (meth)acrylate, etc.), alkoxylated nonylphenyl (meth)acrylate (ethoxylated (4) nonylphenol acrylate, etc.), 2-phenoxyethyl (meth)acrylate, p-cumylphenoxyglycol (meth)acrylate, methylphenoxyethyl acrylate, ethoxylated succinic acid (meth)acrylate, ethoxylated tribromophenyl acrylate, ethoxylated nonylphenyl (meth)acrylate, etc.

[0036] Examples of the monofunctional carboxyl-containing (meth)acrylate compounds include β-carboxyethyl (meth)acrylate, monoacryloxyethyl succinate, ω-carboxypolycaprolactone mono(meth)acrylate, 2-(meth)acryloxyethyl hydrogen phthalate, 2-(meth)acryloxypropyl hydrogen phthalate, 2-(meth)acryloxypropyl hexahydro hydrogen phthalate, 2-(meth)acryloxypropyl tetrahydro hydrogen phthalate, and the like.

[0037] Examples of other monofunctional (meth)acrylate compounds include benzyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, acryloylmorpholine, morpholinylethyl (meth)acrylate, trimethylsiloxyethyl (meth)acrylate, diphenyl-2-(meth)acryloyloxyethyl phosphate, 2-(meth)acryloyloxyethyl acid phosphate, caprolactone-modified-2-(meth)acryloyloxyethyl acid phosphate, 2-hydroxy-1-(meth)acryloyloxy-3-methacryloyloxypropane, acryloyloxyethyl phthalate, 2-(meth)acryloyloxyethyl-2-hydroxyethyl phthalate, 2-(meth)acryloyloxypropyl phthalate, tricyclodecane monohydroxymethyl (meth)acrylate, (meth)acrylic acid dimer, diethylaminoethyl (meth)acrylate, 2-(meth)acryloyloxyethyl succinate, hexahydro-1-(meth)acryloyloxy-3-methacryloyloxypropane, acryloyloxyethyl phthalate, 2-(meth)acryloyloxyethyl phthalate, 2-(meth)acryloyloxypropyl phthalate, tricyclodecane monohydroxymethyl (meth)acrylate, (meth)acrylic acid dimer, diethylaminoethyl (meth)acrylate, 2-(meth)acryloyloxyethyl succinate, hexahydro-1-(meth)acryloyloxy-3-methacryloyloxypropane 2-(Meth)acryloyloxyethyl phthalate, 2-ethylhexyl-diglycol (meth)acrylate, aminoethyl (meth)acrylate, ethylcarbitol acrylate, ethyl diglycol acrylate, dimethylaminoethyl acrylate benzyl chloride quaternary salt, tribromophenyl (meth)acrylate, 1,4-cyclohexanedimethanol mono(meth)acrylate, cresol (meth)acrylate, trimethylolpropane methylal (meth)acrylate, neopentyl glycol (meth)acrylate benzoic acid Ester, (meth)acrylate (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl ester, 1-(meth)acryloylpiperidin-2-one, 2-(meth)acrylate-1,4-dioxaspiro[4,5]deca-2-ylmethyl ester, N-(meth)acryloyloxyethyl hexahydrophthalimide, γ-butyrolactone (meth)acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, imide acrylate, vinyl (meth)acrylate, maleimide, etc.

[0038] Examples of the monofunctional styrene compounds include styrene, vinyltoluene, p-hydroxystyrene, p-chlorostyrene, p-bromostyrene, p-methylstyrene, p-methoxystyrene, p-tert-butoxystyrene, p-tert-butoxycarbonylstyrene, p-tert-butoxycarbonyloxystyrene, 2,4-diphenyl-4-methyl-1-pentene, and divinylbenzene.

[0039] Examples of the monofunctional N-vinyl compound include N-vinyl pyrrolidone, N-vinyl formamide, N-vinyl acetamide, N-vinyl-2-caprolactam, N-vinyl carbazole, vinyl methyl oxazolidinone, and the like.

[0040] Examples of the monofunctional arylate compound include allyl glycidyl ether, diallyl phthalate, triallyl trimellitate, triaryl isocyanurate, and the like.

[0041] Examples of other monofunctional monomers include vinyl acetate, vinyl chloroacetate, vinyl benzoate, vinyl pivalate, vinyl butyrate, vinyl laurate, divinyl adipate, vinyl crotonate, vinyl 2-ethylhexanoate, three-membered ring compounds (e.g., vinyl cyclopropanes, 1-phenyl-2-vinylcyclopropanes, 2-phenyl-3-vinyl oxiranes, 2,3-divinyl oxiranes, etc.), cyclic ketene acetals (e.g., 2-methylene-1,3-dioxane, polydioxolanes, 2-methylene-4-phenyl-1,3-dioxane, 4,7-dimethyl-2-methylene-1,3-dioxane, 5,6-benzo-2-methylene-1,3-dioxane, etc.), and the like.

[0042] The monofunctional photopolymerizable monomer contained in the ultraviolet light-shielding ink composition is preferably a monomer whose odor is suppressed. This is because the ultraviolet light-shielding ink composition becomes a semi-cured state by light irradiation, but is not completely cured. Preferred examples of monofunctional photopolymerizable monomers include acryloylmorpholine, N-vinylcaprolactam, 4-hydroxybutyl acrylate, and the like.

[0043] [1-1-3. Content and composition of photopolymerizable monomers, etc.] The content of the photopolymerizable monomer in the ultraviolet light-shielding ink composition of the present invention is 55.0% by mass or more, preferably 60.0% by mass or more, more preferably 70.0% by mass or more, and may be 80.0% by mass or more; on the other hand, it is usually 90.0% by mass or less, preferably 85% by mass or less. By setting the content of the photopolymerizable monomer to 55.0% by mass or more, the printed layer of the ultraviolet light-shielding ink composition can be cured by polymerization of the photopolymerizable monomer after ultraviolet irradiation.

[0044] The ink composition for ultraviolet light-shielding of the present invention contains a photopolymerizable monomer, at least a multifunctional monomer, and may also contain a combination of a multifunctional monomer and a monofunctional monomer. More specifically, 50.0% or more of the photopolymerizable monomer is a multifunctional monomer, more preferably 60.0% or more, more preferably 70.0% or more, and particularly preferably 80.0% or more by mass. All photopolymerizable monomers may also be multifunctional monomers. When 50.0% or more of the photopolymerizable monomer is a multifunctional monomer, by irradiating the printed layer of the ink composition for ultraviolet light-shielding with ultraviolet rays, it can be easily polymerized and cured. When the proportion of the multifunctional monomer is too low, sometimes the surface layer of the printed layer is cured, but the inner layer of the printed layer fails to cure and remains in a liquid form.

[0045] [1-2. Ultraviolet absorber] The ultraviolet light-shielding ink composition of the present invention contains an ultraviolet light absorber. The ultraviolet light absorber can prevent 1) the photopolymerizable monomer in the ultraviolet light-shielding ink composition from becoming excessively excited by absorbing ultraviolet light, and can also inhibit 2) a portion of ultraviolet light from reaching the bottom layer in the area where the ultraviolet light-shielding ink composition is printed. Therefore, the printed layer of the ultraviolet light-shielding ink composition is polymerized and cured by ultraviolet light irradiation, and the bottom layer, which is a photocurable resin, can be prevented from being completely cured and is kept in a semi-cured state.

[0046] Ultraviolet light absorbers are generally classified into benzotriazole (BTZ) type ultraviolet light absorbers, hydroxyphenyl triazine (HPT) type ultraviolet light absorbers, salicylic acid type ultraviolet light absorbers, benzophenone type ultraviolet light absorbers, cyanoacrylate type ultraviolet light absorbers, polymer type ultraviolet light absorbers, etc.; the ultraviolet light-shielding ink composition of the present invention may contain any type of ultraviolet light absorber, and may also contain one or more ultraviolet light absorbers.

[0047] Examples of benzotriazole (BTZ) ultraviolet absorbers include: 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2-(2-hydroxy-5-tert-butylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)benzotriazole, 2-(3,5-di-tert-pentyl-2-hydroxyphenyl- 2-benzotriazole, 2-(2-benzotriazole-2-yl)-4-methyl-6-(3,4,5,6-tetrahydrophthalimidomethyl)phenol, 2-(2-hydroxy-4-octyloxyphenyl)-2-benzotriazole and 2-(2-hydroxy-5-tert-octylphenyl)-2-benzotriazole. Benzotriazole (BTZ) type UV absorbers are also available on the market and can be used as Sumisorb 200, Sumisorb 250, Sumisorb 300, Sumisorb 340 and Sumisorb 350 (Sumitomo Chemical Co.), TINUVIN PS, TINUVIN 99-2, TINUVIN 234, TINUVIN 320, TINUVIN 326, TINUVIN 328, TINUVIN 329, TINUVIN 384, TINUVIN 384-2, TINUVIN 571, TINUVIN 900, TINUVIN 928 and TINUVIN 1130 (BASF), ADK STAB LA-32, ADK STAB LA-29, ADK STAB LA-31, ADK STAB LA-31RG, ADK STAB LA-31G, ADK STAB LA-36, ADK STAB LA-36RG (ADEKA) and SEESORB SEESORB 701, SEESORB 703, SEESORB 704, SEESORB 706, SEESORB 707 and SEESORB 709 (Shipro Kasei Co., Ltd.) were obtained.

[0048] Examples of hydroxyphenyltriazine (HPT)-based ultraviolet absorbers include 2,4-diphenyl-6-(2-hydroxy-4-methoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-ethoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-(2-hydroxy-4-propoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-butoxyphenyl)-1,3,5-triazine , 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-hexyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-dodecyloxyphenyl)-1,3,5-triazine and 2,4-diphenyl-6-(2-hydroxy-4-benzyloxyphenyl)-1,3,5-triazine, etc. Hydroxyphenyltriazine (HPT)-based ultraviolet absorbers are also commercially available as TINUVIN 400, TINUVIN 405, TINUVIN 460, TINUVIN 477, TINUVIN 479, TINUVIN 777, and TINUVIN 1577ED (BASF), and ADK STAB LA-F70 (ADEKA).

[0049] Examples of salicylic acid-based ultraviolet absorbers include phenyl salicylate, p-tert-butylphenyl salicylate, 3,5-di-tert-butyl-4-hydroxybenzoic acid-2,4-di-tert-butylphenyl ester, etc. Salicylic acid-based ultraviolet absorbers are also commercially available as Sumisorb 400 (Sumitomo Chemical Co., Ltd.), SEESORB 201, SEESORB 202, SEESORB 712 (ShiproKasei Co., Ltd.), etc.

[0050] Examples of benzophenone-based ultraviolet absorbers include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2-hydroxy-4-octadecyloxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, and 1,4-bis(4-benzoyl-3-hydroxyphenoxy)butane. Benzophenone-type UV absorbers are also available on the market, including Sumisorb 130 (Sumitomo Chemical Co., Ltd.), ADK STAB 1413 (ADEKA Co., Ltd.), and SEESORB 100, SEESORB 101, SEESORB 106, SEESORB 107, SEESORB 101S, SEESORB 102, SEESORB 103, SEESORB 105, SEESORB 151 (Shipro Kasei Co., Ltd.), etc.

[0051] Examples of cyanoacrylate ultraviolet absorbers include ethyl 2-cyano-3,3-diphenylacrylate, 2-ethylhexyl 2-cyano-3,3-diphenylacrylate, etc. Cyanoacrylate ultraviolet absorbers are commercially available, including SEESORB 501, SEESORB 502 (Shipro Kasei Co., Ltd.), Uvinul 3039, Uvinul 3035 (BASF Co., Ltd.), etc.

[0052] The so-called polymer UV absorber can be a copolymer of an acrylic monomer having a skeleton (the aforementioned benzophenone, benzotriazole, triazine, etc.) that functions as a UV absorber in the side chain and other ethylenically unsaturated compounds (acrylic acid, methacrylic acid and their derivatives, styrene, vinyl acetate, etc.). Examples of polymer ultraviolet absorbers include polymer ultraviolet absorbers for coatings ULS-700, ULS-1700, ULS-383MA, ULS-1383MA, ULS-383MG, ULS-385MG, ULS-1383MG, ULS-1385MG, ULS-635MH, ULS-933LP, ULS-935LH, ULS-1935LH, HC-935UE, XL-504, XL-524, XL-547, XL-729, XL-730, etc. (Ipposha Oil & Fats Industry Co., Ltd.) and polymer ultraviolet absorbing resin coatings NCI-905-20EM and NCI-905-20EMA (polymer ultraviolet absorbers formed by copolymers of styrene monomers and benzotriazole monomers) (Nikko Chemical Research Institute Co., Ltd.).

[0053] The content ratio of the ultraviolet light-shielding ink composition of the present invention is 3.0 mass % or more, preferably 4.0 mass % or more; on the other hand, it is less than 15.0 mass %, preferably 12.0 mass % or less. When the content ratio of the ultraviolet light-shielding ink composition is 3.0 mass % or more, the ultraviolet light-shielding ability is sufficient, and the excessive polymerization of the ultraviolet light-shielding ink composition itself or the irradiation of the ultraviolet light to the bottom layer of the printed layer of the ultraviolet light-shielding ink composition can be appropriately suppressed. On the other hand, when the content ratio of the ultraviolet light-shielding ink composition is less than 15.0 mass %, the ultraviolet light can penetrate the printed layer of the ultraviolet light-shielding ink composition and irradiate the bottom layer appropriately, and the bottom layer can be cured in a semi-cured state.

[0054] The ultraviolet light-shielding ink composition of the present invention is distinguished from the light stabilizer. The light stabilizer is an agent that eliminates free radicals generated by ultraviolet irradiation, and is different from a substance that can inhibit the generation of free radicals itself, such as the ultraviolet light-shielding ink composition of the present invention. The ultraviolet light-shielding ink composition of the present invention contains at least an ultraviolet light absorber and may also contain a light stabilizer.

[0055] Examples of light stabilizers include hindered amine compounds (HALS); specifically, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, bis-(2,2,6,6-tetramethyl-4-piperidinyl) malonate, bis-(2,2,6,6-tetramethyl-4-piperidinyl) phthalate, 2,2,6,6-tetramethyl-4-piperidinyl benzoate, 4-amino-2,2,6,6-tetramethylpiperidine, 2,2,6,6-tetramethyl-4-piperidinyl) sebacate, bis-(2,2,6,6-tetramethyl-4-methylpiperidinyl) sebacate, di-(1,2,2,6,6-pentamethyl-4-piperidinyl)-2-n-butyl-2-(3,5-di-tert-butyl-4-hydroxybenzyl) malonate ester, bis-(2,2,6,6-tetramethyl-4-carbonyloxypiperidinyl)-p-dimethylbenzyl ester, 2,2,4,4-tetramethyl-7-oxa-3,20-diaza-21-oxo-bisspiro[5.1.9.19]heneicosane, bis-(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, dimethyl succinate, 2-(4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyl) acetylene alcohol condensate, [(6-(1,1,3,3-tetramethylbutyl)imino)-1,3,5-triazine-2,4-diyl-(4-(2,2,6,6-tetramethylpiperidinyl)imino)-hexamethylene-(4-(2,2,6,6-tetramethylpiperidinyl)imino)].

[0056] [1-3. Non-polymeric materials] The ultraviolet light-shielding ink composition of the present invention contains a non-polymerizable material while containing a photopolymerizable monomer and an ultraviolet absorber. When the ultraviolet light-shielding ink composition contains a non-polymerizable material, the hardness of the ink composition after the photopolymerizable monomer is polymerized and cured can be reduced, and it is preferred to give the cured ink composition "brittleness". As a result, the cured printing layer is easily removed or peeled off from the printed object. The non-polymerizable material preferably contains a non-polymerizable high molecular compound and a non-polymerizable low molecular compound in combination. This is to facilitate the adjustment of the viscosity of the ultraviolet light-shielding ink composition.

[0057] [1-3-1. Polymer compound as non-polymer material] The polymer compound as the non-polymerizable material preferably does not have a crosslinking group, etc., and does not react with other components (especially photopolymerizable monomers) of the ultraviolet light-shielding ink composition to polymerize. The polymer compound as the non-polymerizable material is preferably a thermoplastic resin, and examples thereof include polyacrylic acid, polymethacrylic acid, polymethacrylate, polyethylacrylic acid, styrene-butadiene copolymer, polybutadiene, acrylonitrile-butadiene copolymer, chloroprene copolymer, fluororesin, vinylidene fluoride, polyolefin resin, cellulose, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, polystyrene, styrene-acrylamide copolymer, polyisobutyl acrylate, polyacrylonitrile, polyvinyl acetate, polyvinyl acetal, polyamide, rosin resin, polyethylene, polycarbonate, vinylidene chloride resin, cellulose resin, vinyl acetate resin, ethylene-vinyl acetate copolymer, vinyl acetate-acrylic acid copolymer, vinyl chloride resin, polyurethane, rosin ester, etc. Specific examples of relatively low molecular weight thermoplastic resins include polyethylene wax, montan wax, wax alcohol, synthetic oxidized wax, α-olefin-maleic anhydride copolymer, animal and plant waxes such as carnauba wax, lanolin, paraffin wax, and microcrystalline wax.

[0058] [1-3-2. Low molecular weight compound as non-polymerizable material] The low molecular weight compound as the non-polymerizable material is preferably a low molecular weight compound that does not react with other components of the ultraviolet light-shielding ink composition, and preferred examples thereof include 1) a sublimable substance (sublimable substance) and 2) terpenes.

[0059] Examples of the sublimable substance include alizarin, alloxan, amantadine, (3α,5α)-androst-16-en-3-ol, anthraquinone, caffeine, chloranil, chloroacetamide, p-dichlorobenzene, rhubarb, homoeriodictyol, cubane, cysteamine, fraxin, guanine, hexachloroethane, isatin, luciferin, maleic anhydride, 1,4-naphthoquinone, nimbiol, phenazine, phthalimide, 2,5-diketopiperazine, 1H-purine, purpurin, pyrene, quinalizarin, p-benzoquinone, saccharin, aconitum, succinic anhydride, thebaine, xanthine, and d-camphor.

[0060] Examples of terpenes include monoterpene hydrocarbons such as α-pinene, β-pinene, dipentene, limonene, turpentine, phellandrene, α-terpinene, γ-terpinene, terpinene, myrcene, alloocimene, camphene, bornene, p-menthene-1, p-menthene-2, p-menthene-3, p-menthadiene, p-menthane, 2-carene, 3-carene, and thujne; and α-terpineol, β-terpineol, γ-terpineol, 4-terpineol, p-menthenol, p-menthanol, geraniol, linalool, Monoterpene alcohols such as nerol, citronellol, alloocimenol, myrcenol, carveol, menthol, borneol, isoborneol, phenylethyl alcohol, verbenol; terpene aldehydes such as citral and citronellal; terpene ketones such as isopulegone, carvone, camphor (camphor white oil); terpene diols such as p-menthane diol; terpene ethers such as 1,4-cineole and 1,8-cineole; sesquiterpene hydrocarbons such as longifolene, caryophyllene, juniper terpene, thujopsis, cedrene, caryophyllene, longifole pinene; sesquiterpene alcohols such as elemenol, cadinol, eucalyptol, etc.

[0061] The ultraviolet light shielding ink composition may preferably contain menthol which is a low molecular weight compound as a non-polymerizable material.

[0062] [1-3-3. Content or composition of non-polymerizable materials, etc.] The content of the non-polymerizable material in the ultraviolet light-shielding ink composition is preferably set in a manner that the cured product can be given "brittleness" when the ultraviolet light-shielding ink composition is cured by ultraviolet irradiation. Therefore, the ultraviolet light-shielding ink composition contains more than 10.0% by mass of non-polymerizable material, preferably more than 15.0% by mass, and sometimes more than 20.0% by mass. On the other hand, when the content of the non-polymerizable material is too much, the viscosity of the ultraviolet light-shielding ink composition increases, or a part of the non-polymerizable material cannot be dissolved in the ink composition, and sometimes printing by inkjet becomes unstable (the ejection stability decreases), so the content is set to less than 30.0% by mass.

[0063] Furthermore, since a high molecular weight compound as a non-polymerizable material is particularly likely to increase the viscosity of the ultraviolet light-shielding ink composition, it is preferred to adjust the amount of the high molecular weight compound by combining it with a low molecular weight compound.

[0064] [1-4. Other ingredients] The UV light-shielding ink composition of the present invention may also contain a surface adjuster for adjusting the surface tension. As described later, since the UV light-shielding ink composition sometimes preferably has a higher surface tension, it may contain a surface adjuster for increasing the surface tension. Surface adjusters for increasing the surface tension are, for example, amine compounds, polyether macromonomer-modified polyacrylates (available as BYK3560 (BYK Chemie)), polyether siloxane macromonomer-modified polyacrylates (available as BYK3565 (BYK Chemie)), etc. When the UV light-shielding ink composition contains a surface adjuster, its content is preferably in the range of 0.01 to 1.0% by mass.

[0065] The ultraviolet light-shielding ink composition of the present invention may contain a colorant (preferably a dye). This is to make it easy to find the area printed by the ultraviolet light-shielding ink composition, so as to facilitate the identification of the area to be removed. When the ultraviolet light-shielding ink composition contains a dye, its content is preferably in the range of 0.01 to 2.0 mass %.

[0066] The ultraviolet light-shielding ink composition of the present invention generally does not contain a solvent, but may contain a small amount (eg, 5% by mass or less relative to the ink composition) of an organic solvent when viscosity adjustment is required.

[0067] [1-5. Physical properties of ultraviolet light shielding ink composition] Since the ultraviolet light-shielding ink composition of the present invention is printed by an inkjet method, its viscosity (25° C.) is preferably 10 cps or more, more preferably 12 cps or more, and on the other hand, preferably about 30 cps or less. The viscosity is, for example, a value measured by an E-type viscometer (25° C., rotor speed 10 rpm).

[0068] The ultraviolet light-shielding ink composition of the present invention is sometimes preferably higher in surface tension. The ultraviolet light-shielding ink composition of the present invention is sometimes printed on a liquid film or layer (bottom layer). In this case, since the ultraviolet light-shielding ink composition with high surface tension has low compatibility with the liquid film or layer, it will not be mixed with the liquid film or layer (bottom layer). As a result, the ultraviolet light-shielding ink composition can be selectively printed on a desired area, and ultraviolet light shielding can be selectively performed on the area.

[0069] When the ultraviolet light-shielding ink composition contains a photopolymerizable monomer having a polar group (hydroxyl group, amino group, aromatic group, etc.), the surface tension thereof is generally likely to be increased.

[0070] [1-6. Production of UV-shielding ink composition] The ultraviolet light-shielding ink composition of the present invention can be produced by any method. For example, a non-polymerizable material is added to and mixed with a photopolymerizable monomer, preferably dissolved, and then further mixed with an ultraviolet absorber or other components to obtain an ultraviolet light-shielding ink composition.

[0071] [2. Method for producing a substrate having an embossed surface] The method for manufacturing a substrate with an embossed surface of the present invention comprises the following steps: 1) a coating step of coating a composition containing a photopolymerizable compound on the surface of the substrate to thereby coat a coating film; 2) a printing step of inkjet printing an ultraviolet shading ink composition on the uncured coating film containing the photopolymerizable compound coated on the substrate; 3) an irradiation step of irradiating the coating film printed with the ultraviolet shading ink composition with ultraviolet rays; and 4) a removal step of removing the coating film in the area printed with the ultraviolet shading ink composition; it may further comprise 5) a finishing step of forming other layers on the surface of the embossed structure, etc.

[0072] The following reference Figure 1 , a method for producing a substrate having an embossed surface is described.

[0073] [2-1. Coating process] The coating step is a step of coating the surface of the substrate (1) with a coating film (2-1) (see Figure 1 (a)). The substrate (1) may be any material on which an embossed structure is to be formed. The material may be plastic, metal, wood, paper, cement, plaster, rock, glass, ceramic, etc. There is no particular limitation. In addition, it is sometimes preferred to perform a surface treatment on the substrate surface on which an embossed structure is to be formed to improve wettability. This is to facilitate coating of a coating film on the substrate surface.

[0074] [2-1-1. Photocurable resin composition to be applied] The coating film (2-1) applied on the surface of the substrate (1) is preferably composed of a photocurable resin composition. The photocurable resin composition contains a photopolymerizable compound (preferably a monomer or oligomer having photocurability), more preferably a photopolymerization initiator, and may also contain a filler or a surface conditioning agent.

[0075] The photopolymerizable compound contained in the photocurable resin composition is preferably a photocurable resin, for example, including photocurable diallyl phthalate resin, epoxy resin, unsaturated polyester resin, polyurethane resin, acrylic resin, etc. Among them, as a free radical polymerizable resin, diallyl phthalate resin, vinyl monomer or acrylic resin (acrylate monomer, epoxy acrylate, polyurethane acrylate, polyester acrylate, polyether acrylate, acrylic amino ester, silicone acrylate, polyisoprene acrylate, polybutadiene acrylate) and the like can be listed. The content of the photopolymerizable compound in the photocurable resin composition is 70% by mass or more, preferably 75% by mass or more, and on the other hand, it is 95% by mass or less, more preferably 90% by mass or less, as a reference.

[0076] The photocurable resin composition may contain one or more photopolymerization initiators. Examples of the photopolymerization initiator include benzophenone, diethylthioxanthone, 2-methyl-1-(4-methylthio)phenyl-2-morpholinopropane-1-one, 4-benzoyl-4′-methyldiphenyl sulfide, 1-chloro-4-propoxythioxanthone, isopropylthioxanthone, 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1-hydroxycyclohexylphenyl ketone, bis-2,6-dimethoxybenzoyl-2,4,4-trimethylpentylphosphine oxide, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one, 2,2-dimethyl-2-hydroxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,4,6-trimethylbenzyl-diphenylphosphine oxide, and 2-benzyl-2-dimethylamino-1-(morpholinophenyl)-butane-1-one. Such a photopolymerization initiator is commercially available, for example, under the trade names of Irgacure 907, Irgacure 369, Irgacure 184, Irgacure 379, and Irgacure 819 (all from BASF), and DETX (from Lamberti).

[0077] The content of the photopolymerization initiator in the applied photocurable resin composition can be set according to the desired curing speed of the photocurable resin composition. For reference, it is preferably 1% by mass or more, more preferably 3% by mass or more, and is preferably 10% by mass or less, more preferably 7% by mass or less.

[0078] The photocurable resin composition preferably has a low surface tension, and therefore, may contain a surface adjuster for reducing the surface tension. Such a surface adjuster can improve the leveling and smoothness of the photocurable resin composition. Examples of surface adjusters include: silicone surface adjusters, fluorine surface adjusters, acrylic surface adjusters, acetylene glycol surface adjusters, etc. Specific examples of surface adjusters for reducing surface tension include: BYK series (BYK377, etc.) manufactured by BYK Chemical, TEGO series manufactured by EVONIK, Polyflow series manufactured by Kyoei Chemical Co., Ltd., etc. When the photocurable resin composition contains a surface adjuster, its content is preferably in the range of 0.01 to 1.0% by mass.

[0079] By making the photocurable resin composition contain a filler, the physical properties (hardness, etc.) of the cured product can be adjusted. For example, aluminum oxide, etc., for improving the wear resistance of the cured product, talc for adjusting the deformability (rheology), silica for reducing brittleness, calcium carbonate as an extender, and a colorant for coloring can be formulated. Furthermore, by containing a thixotropic agent, the photocurable resin composition can easily maintain the shape of the coating film in the uncured state, and sometimes it is easier to form an embossed structure of a desired shape.

[0080] The photocurable resin composition may contain a matting agent. The matting agent is an agent used to finely roughen the surface of the cured product (also called matting treatment), and examples thereof include resin beads and inorganic beads such as silica or alumina.

[0081] Furthermore, the photocurable resin composition generally does not contain a solvent (a component removed after curing), but may contain a small amount of a solvent for the purpose of obtaining coating characteristics or the like.

[0082] [2-1-2. Coating film] The thickness of the coating film (2-1) applied on the surface of the substrate (1) can be set according to the shape of the embossed surface to be formed. The thicker the coating film (2-1), the more an embossed surface with a height difference can be formed. The thickness of the coating film (2-1) can be set to 30 μm or more, 100 μm or more, or about 200 μm. The upper limit of the thickness of the coating film (2-1) can be appropriately set according to the purpose of the substrate with an embossed surface to be manufactured.

[0083] The photocurable resin composition constituting the coating film (2-1) is preferably completely photocured to obtain a cured product (2-2) having a pencil hardness of 2H or higher. The specific hardness of the cured product (2-2) can be adjusted according to the application of the substrate having an embossed surface to be manufactured.

[0084] [2-2. Printing process] The printing step is a step of inkjet printing the ultraviolet light shielding ink composition (3-1) on the coating film (2-1) applied on the surface of the substrate (1) (see Figure 1 (b)). The ultraviolet light-shielding ink composition is preferably the one described in [1. Ultraviolet light-shielding ink composition].

[0085] The method used for inkjet printing is not particularly limited. For example, the inkjet printing method can be any one of a multi-path mode (serial head mode) and a single-path mode (line head mode).

[0086] The area printed with the ultraviolet light-shielding ink composition will become the concave part of the formed embossed shape, so it is sufficient to print according to the desired embossed shape. The printing coating amount of the ultraviolet light-shielding ink composition per unit area is set to a coating amount that can completely cover the desired printing area and make the coating film (2-1) in the area printed with the ultraviolet light-shielding ink composition (3-1) reach a semi-cured state. If the printing coating amount per unit area is large, the curing reaction of the coating film (2-1) is difficult to proceed, and if the coating amount is small, the curing reaction is easy to proceed.

[0087] [2-3. Irradiation process] The irradiation step is a step of irradiating the coating film (2-1) printed with the ultraviolet light shielding ink composition (3-1) with ultraviolet rays (see Figure 1 (c)). The exposure machine (4) for irradiating ultraviolet rays is not particularly limited, as long as it can irradiate ultraviolet rays with a specified exposure amount. From the perspective of productivity, it is preferably a device that irradiates a specified ultraviolet light amount in a short time. In the coating film (2-1), the area that is not printed by the ultraviolet light-shielding ink composition (3-1) is fully photocured due to direct irradiation with ultraviolet rays, and becomes a completely cured product (2-2). On the other hand, in the coating film (2-1), the area printed by the ultraviolet light-shielding ink composition (3-1) is irradiated with ultraviolet rays through the printed layer of the ultraviolet light-shielding ink composition (3-1), so photocuring is not completely carried out, and it is cured in the form of a semi-cured product (2-3). In addition, the ultraviolet light-shielding ink composition (3-1) will also become a cured product (3-2) due to ultraviolet irradiation.

[0088] The amount of ultraviolet light exposure to the coating film may be an amount sufficient to make the coating film (2-1) a completely cured product (2-2); if the amount of ultraviolet light exposure is too much, the photocuring of the semi-cured product (2-3) will continue, and there is a risk of it becoming a completely cured product. Therefore, the amount of ultraviolet light exposure is preferably set to a sufficient amount to make the coating film (2-1) in the area without the printed layer of the ultraviolet light-shielding ink composition (3-1) become a completely cured product (2-2). That is, the amount of ultraviolet light exposure should be appropriately set according to the ease of photocuring of the ultraviolet light-shielding ink composition (3-1) and the amount of printing of the ultraviolet light-shielding ink composition (3-1).

[0089] The hardness of the cured product (2-2) of the coating film (2-1) varies depending on the purpose of the embossed material, and is generally preferably 2H or more in pencil hardness. On the other hand, the hardness of the semi-cured product (2-3) of the coating film (2-1) can be lower than the hardness of the cured product (2-2). That is, the hardness of the semi-cured product (2-3) can be less than 2H in pencil hardness, but it can also have a higher hardness depending on the hardness of the cured product (2-2). That is, if a) the hardness of the cured product (2-2) is high, the hardness of the semi-cured product (2-3) can also be improved. In addition, if b) the removal ability (peeling ability) of the removal method in the following removal process is high, the hardness of the semi-cured product (2-3) may also be improved.

[0090] [2-4. Removal process] The removal step is a step of removing the semi-cured product (2-3) and the cured product (3-2) formed in the irradiation step (see Figure 1 (d)). On the other hand, since the hardness of the cured product (2-2) of the coating film (2-1) is relatively high, it cannot be removed by the removal process. These removals are performed mechanically, preferably by wiping the coating film with a brush (5) or a pad. The material of the brush (5) or the pad may be, for example, steel, brass, nylon fiber, polyester fiber, etc., but is not particularly limited. In addition, as another form of removal, the semi-cured product (2-3) and the cured product (3-2) may be removed by high-pressure air jet or high-pressure water jet, etc.; the semi-cured product (2-3) and the cured product (3-2) may also be removed by peeling off the semi-cured product (2-3) and the cured product (3-2) with an adhesive roller or an adhesive tape.

[0091] By removing the semi-cured material (2-3) and the cured material (3-2), the removed portions can be made into recessed portions, thereby forming an embossed structure on the surface of the substrate (1).

[0092] [2-5. Finishing process] In order to impart weather resistance, friction resistance, abrasion resistance, and solvent resistance to the embossed structure formed on the surface of the substrate (1), an arbitrary coating layer (6) may be applied (see Figure 1(e)). In addition, by forming a coating film of varnish, etc., it is possible to adjust the desired appearance (brightness, brightness, chroma, etc.). In addition, any finishing treatment can be performed.

[0093] The article having the embossed shape produced in the above manner can be used as any building material (paving material, wall material, floor material, etc.), skirting board, decorative board of furniture, etc.

[0094] Example The present invention will be described below with reference to Examples, but the present invention is not limited to these Examples. In the description of the Examples, "%" means "mass %", and "part" means "mass part" unless otherwise stated.

[0095] [A. Preparation of UV-shielding ink composition] The materials used for preparing the ultraviolet light shielding ink composition are as follows.

[0096] [A-1. Photopolymerizable monomer] ・1,6-Hexanediol diacrylate ・ Neopentyl glycol PO-modified diacrylate ((PO)NPGDA): Miramer M216 (Toyo Chemical Co., Ltd.) ・Trimethylolpropane EO-modified triacrylate ((EO)TMPTA): Miramer M3130 (Toyo Chemical Co., Ltd.) ・Acryloylmorpholine ・N-vinyl caprolactam ・4-Hydroxybutyl acrylate [A-2. Non-polymeric materials] ・Acrylic polymer: DEGALAN LP 66 / 02N (EVONIK) Glass transition temperature 75°C, molecular weight (DIN standard) 60,000 ・L-Menthol [A-3. Ultraviolet absorber, etc.] ・Hydroxyphenyltriazine (HPT) type UV absorber: TINUVIN400 (BASF) ・Benzotriazole (BZT) type UV absorber: TINUVIN384 (BASF) ・Hindered amine light stabilizer (HALS): TINUVIN123 (BASF) [Chemistry 1]

[0097] [A-4. Preparation process of ultraviolet light shielding ink composition] According to the formulations shown in Tables 2 and 3, the photopolymerizable monomer, the non-polymerizable material, the ultraviolet absorber or the light stabilizer were mixed to obtain the ultraviolet light-shielding ink compositions of Examples 1 to 9 and Comparative Examples 1 to 7. In addition, the acrylic polymer (DEGALAN LP 66 / 02N) as the non-polymerizable material was heated to dissolve the photopolymerizable monomer and then mixed with the other materials.

[0098] [B. Production of substrate having embossed surface] MDF (Medium Density Fiberboard) was prepared as a substrate; a photocurable resin composition having the composition shown in Table 1 was applied to the surface of the substrate using a roller coater to form a coating film (film thickness 50 μm). The prepared UV light-shielding ink composition was inkjet printed on the coating film (in an uncured state). Printing was performed using a UV inkjet ink printing evaluation device (300 dpi, droplet volume (5 pL to 50 pL)) equipped with a Ricoh GEN6 inkjet head, as shown in FIG. Figure 2 As shown, the alphabetic characters are drawn. The ink composition for inkjet printing is printed in a single-path printing, 80-100% solid printing mode so as to completely cover the area to be drawn. After printing, 100 mJ / cm 2 By brushing the cured resin surface with a plastic brush, the resin on the printed part can be peeled off and removed.

[0099] [Table 1]

[0100] [C. Evaluation] [C-1. Viscosity of UV-shielding ink composition] The viscosity (cps) of the ink composition obtained in each example and comparative example was measured using an E-type viscometer (trade name: RE100L type viscometer, manufactured by Toki Sangyo Co., Ltd.) at a temperature of 25° C. and a rotor speed of 10 rpm.

[0101] [C-2. Embossing suitability: peelability] The workability of brushing and the peeling state were evaluated according to the following criteria.

[0102] ◎: Only the printed part can be scraped off easily and cleanly ○: Only the printed part is scraped off cleanly △: Part of the printed part could not be scraped off and there was some residue ×: The printed part is almost impossible to scrape off, or the part above the necessary area is excessively removed [C-3. Embossing suitability: shape] The state after brushing was visually confirmed and evaluated based on the following criteria.

[0103] 0:The text represented by the concave part can be clearly presented as shown in the design drawing ×: The text represented by the concave part is not displayed as designed. The text is flatter or wider than the design. [C-4. Discharge stability] 0: Printing is smooth and stable △: There is a little printing disorder, but the printing is basically stable. ×: Printing is disordered or the jetting is not stable [Table 2]

[0104] [Table 3]

[0105] As shown in Comparative Example 1 of Table 3, the ink composition for UV light shielding containing a total of 35.0% by mass of non-polymerizable materials is not fully compatible and dissolved in the ink composition, so the ink jet ejection is unstable and printing according to the design drawing cannot be performed. Therefore, the embossed shape cannot be produced. On the other hand, as shown in Example 3 of Table 2, it can be seen that the ink composition for UV light shielding containing a total of 25.0% by mass of non-polymerizable materials has stable ink jet ejection and excellent embossing suitability.

[0106] As shown in Comparative Example 2 of Table 3, when an embossed shape is made using an ultraviolet light-shielding ink composition containing a light stabilizer but not containing an ultraviolet light absorber, the coating film is completely cured and cannot be scraped off by brushing, so that an embossed shape cannot be formed. Similarly, as shown in Comparative Example 3 of Table 3, when an embossed shape is made using an ultraviolet light-shielding ink composition containing 2.0% by mass of an ultraviolet light absorber, the coating film is completely cured and cannot be scraped off by brushing, so that an embossed shape cannot be formed. That is, when drawing the letter "A", the coating film is completely cured and cannot be scraped off by brushing. Figure 2 As shown in (4), in Comparative Examples 2 and 3, the coating film of the text portion could not be scraped off, and thus the text was difficult to recognize.

[0107] On the other hand, as shown in Comparative Example 4 of Table 3, when the embossed shape was produced using the ultraviolet light shielding ink composition containing 15.0 mass % of the ultraviolet absorber, the coating film was not sufficiently cured and remained in a liquid state, and the uncured portion of the coating film could not be removed by brushing ( Figure 2 (1)).

[0108] In contrast, as shown in Examples 1-9 of Table 2, when an embossed shape is produced using an ultraviolet light-shielding ink composition containing 3.0 to 12.0 mass % of an ultraviolet absorber, the coating film is cured in a semi-cured state and can be removed by brushing, thereby producing an embossed shape that is similar to the design. Figure 1 Thus, it can be seen that the embossed shape can be produced by using an ultraviolet light-shielding ink composition containing an appropriate amount of ultraviolet absorber. Figure 2 As shown in (2), in Examples 1 to 9, the coating film of the text portion can be selectively scraped off, so that the text can be clearly recognized.

[0109] Furthermore, as shown in Comparative Example 5 of Table 3, when an embossed shape was produced using an ultraviolet light-shielding ink composition containing 10.0% by mass of a multifunctional monomer and 71.5% by mass of a monofunctional monomer as a photopolymerizable monomer, the surface layer of the coating film continued to cure and could not be removed by brushing ( Figure 2 (4)).

[0110] In contrast, as shown in Examples 1 to 9 in Table 2, when an ultraviolet light-shielding ink composition containing at least 51.5% by mass of a multifunctional monomer as a photopolymerizable monomer is used to produce an embossed shape, the coating film is cured in a semi-cured form and can be removed by brushing, thereby producing a design similar to that of the present invention. Figure 1 Thus, it can be seen that the production of embossed shapes can be achieved by using an ultraviolet light-shielding ink composition containing a certain amount or more of a multifunctional monomer.

[0111] As shown in Comparative Examples 6 and 7 in Table 3, the UV light-shielding ink composition containing no non-polymerizable material (Comparative Example 6) or containing 5.0% by mass of non-polymerizable material (Comparative Example 7) has a low viscosity, so the ink jetting is slightly unstable. In addition, the hardness of the cured coating film is higher than the required level due to light irradiation, and some areas of the coating film cannot be scraped off by brushing. That is, from the drawing of the letter "A", the ink jetting is slightly unstable. Figure 2 (2) Drawing the "K" Figure 2 (3) shows that in Comparative Examples 6 and 7, Figure 2 As shown in (3), part of the coating film on the text part cannot be scraped off.

[0112] In contrast, in Examples 1 to 9 of Table 2 containing at least 12.5% ​​by mass of non-polymerizable materials, the UV light-shielding ink composition can be stably printed by inkjet, and the embossing suitability is also well received. This shows that by including a certain amount of non-polymerizable material in the UV light-shielding ink composition, inkjet printing is stable and the cured product of the coating film can be easily removed.

[0113] Comparing Examples 1 and 2 (the content of the ultraviolet absorber is 6.0 mass %) and Examples 4 (the content of the ultraviolet absorber is 4.0 mass %) and 5 (the content of the ultraviolet absorber is 12.0 mass %) in Table 2, it can be found that the results of Examples 1 and 2 are better evaluated in the evaluation of the peelability. It can be seen that by adjusting the content of the ultraviolet absorber, the hardness of the semi-cured product of the coating film can be adjusted, so that the embossed shape can be made easier.

[0114] Industrial Applicability According to the ultraviolet light-shielding ink composition of the present invention, by printing it on any article, the irradiation of the article with ultraviolet rays can be suppressed. The ultraviolet light-shielding ink composition of the present invention is particularly suitable for making an embossed shape on the surface of an article, and the article made into an embossed shape can also be used as any building material (paving material, wall material, floor material, etc.), skirting, furniture, etc. Decorative board.

Claims

1. An ultraviolet shading ink composition, which is an ultraviolet shading ink composition for inkjet printing, characterized in that: The ink composition contains 55.0% by mass or more of a photopolymerizable monomer, 3.0% by mass or more and less than 15.0% by mass of an ultraviolet absorber, and 10.0% by mass or more and less than 30.0% by mass of a non-polymerizable material, The content ratio of the polyfunctional monomer in the photopolymerizable monomer is 50.0 mass % or more relative to the photopolymerizable monomer.

2. The ultraviolet light-shielding ink composition according to claim 1, characterized in that: The non-polymerizable material includes a non-polymerizable high molecular compound and a non-polymerizable low molecular compound.

3. The ultraviolet light-shielding ink composition according to claim 1 or 2, characterized in that: It is used for inkjet printing on an uncured coating film containing a photopolymerizable compound.

4. The ultraviolet light-shielding ink composition according to claim 3, characterized in that: The coating film contains a photopolymerization initiator.

5. A method for producing a substrate having an embossed surface, characterized in that: The following processes are available: Step A of inkjet printing the ultraviolet light-shielding ink composition according to claim 1 on an uncured coating film containing a photopolymerizable compound applied on a substrate; Step B of irradiating the coating film printed with the ultraviolet light-shielding ink composition with ultraviolet rays; A step C of removing the coating film in the area printed with the ultraviolet light shielding ink composition.

6. The manufacturing method according to claim 5, characterized in that: The coating film has a thickness of 30 μm or more.

7. The manufacturing method according to claim 5 or 6, characterized in that: The step C is a mechanical removal step.

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