Active energy ray-curable composition and method for producing printed matter using the same

Abstract

To provide an active energy ray curable composition having a biomass account improved by addition of a vegetable oil and sufficient adhesiveness to a printed matter and a printing substrate of a hardened film.SOLUTION: An active energy ray curable composition of the present invention comprises a compound comprising an ethylenically unsaturated bond, a photopolymerization initiator, and a vegetable oil or its fatty acid ester, and further comprising a phosphate (meth) acrylate compound as part of the compound comprising the ethylenic unsaturated bond. The addition of vegetable oil reduces the adhesion of the hardened material to the surface of the printed matter, but this is supplemented by adding a phosphate (meth) acrylate.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an active energy ray-curable composition, a method for producing a printed matter using the same, and a method for improving the adhesion of an active energy ray-curable varnish composition to the surface of a printed matter.

Background Art

[0002] After printing on the surface of various substrates such as film, sheet, and plate, a varnish composition may be applied to the surface of the printed matter for the purpose of protecting the printed surface or obtaining cosmetic effects such as a glossy or matte finish. Such varnish compositions include those of the type supplied to and applied in the ink fountain of an offset printing press (OP varnish) and those of the type applied to a coater such as a flexo coater. Recently, active energy ray-curable varnish compositions have been widely used as such varnishes. Active energy ray-curable varnish compositions are preferable in terms of work efficiency because they instantly dry compared to conventional oil-based OP varnishes, and they do not emit VOCs (volatile organic compounds) into the atmosphere like conventional solvent-based coating agents, so they are also preferable from the perspective of environmental protection. Due to these advantages, there has been a rapid shift from coating processes using conventional varnish compositions to coating processes using active energy ray-curable varnish compositions. Such surface varnish processing is widely applied not only to ordinary printed matters such as magazine covers, posters, calendars, etc., but also to the packaging field such as carton printed matters, and has become familiar in our lives.

[0003] It is known that such active energy ray-curable varnish compositions can impart various functions such as adhesion to a substrate, high gloss, and blocking resistance by combining compounds necessary for curing such as monomers and oligomers having ethylenically unsaturated bonds with various components as needed (see, for example, Patent Documents 1 to 3, etc.).

[0004] By the way, in recent years, environmental load reduction activities have been carried out in various industries and sectors, and the ultimate goal is common in global environmental conservation. Even in the printing ink industry, activities to promote environmental load reduction have been carried out from various viewpoints, and various certification marks are attached to products that conform to the purpose of such activities. Such certification marks include NL regulation mark, Vegetable mark, GP mark, Cleon mark, etc. Among these, recently, the Ink Green Mark (hereinafter referred to as IG Mark) system has been newly established by the Printing Ink Industry Federation. The IG Mark mainly uses the ratio of components derived from biomass among the components constituting printing materials such as ink compositions and varnish compositions as an index, and ranks the environmental response levels of ink compositions and varnish compositions in three stages according to the degree. That is to say, this system can be characterized as promoting the replacement of raw materials derived from fossil resources with raw materials derived from biomass for the purpose of reducing environmental load.

[0005] Even in the above-mentioned active energy ray-curable varnish compositions, products that can be dried by irradiating less ultraviolet rays and energy-saving products that can be dried by the light of light-emitting diodes (LEDs) with low power consumption are on sale, and the movement aiming at reducing environmental load is spreading as in other ink compositions and varnish compositions. However, in active energy-curable ink compositions and varnish compositions, since a large amount of monomers and oligomers must be used as their components, it is considered difficult to use a large amount of components derived from biomass. Therefore, the above-mentioned IG Mark certification criteria do not include the ratio of components derived from biomass, and instead, environmental response characteristics such as recyclability and energy-saving measures are currently used as indicators.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

[0007] Against the background as described above, even in the case of an active energy ray-curable varnish composition, increasing the proportion of biomass-derived components is socially useful and can be said to be extremely significant. As one method for increasing the biomass component ratio (biomass count) in an active energy ray-curable varnish composition, it is conceivable to use vegetable oil as a part of its constituent components. Vegetable oil itself has a biomass count of almost 100%, and the compounds that make it up contain unsaturated bonds in their molecules. Although its radical reactivity is much inferior to that of ordinary monomers, it can still be expected. However, according to the studies of the present inventors, when vegetable oil is applied to an active energy ray-curable varnish composition, it has been found that the adhesion of the cured film formed after curing the composition to the printed matter decreases, which may cause practical problems.

[0008] The present invention has been made in view of the above circumstances, and an object thereof is to provide an active energy ray-curable composition in which the biomass count is improved by adding vegetable oil and which has sufficient adhesion of the cured film to printed matter or a printing substrate. [Means for Solving the Problems]

[0009] As a result of intensive studies to solve the above problems, the present inventors have found that even when vegetable oil is added to an active energy ray-curable varnish composition, by further adding a phosphoric acid (meth) acrylate compound to the composition, the adhesion of the coating made of the cured product to the printed matter is greatly improved, and the present invention has been completed. The effect is sufficient not only in an OP varnish composition in which a relatively thin coating is formed, but also in a coating type varnish composition having a low viscosity and forming a thick coating by a coater. Therefore, the present invention can be similarly applied to a flexographic ink composition having a low viscosity. More specifically, the present invention provides the following.

[0010] The present invention includes a compound having an ethylenically unsaturated bond, a photopolymerization initiator, and a vegetable oil or a fatty acid ester thereof, The content of the compound having the ethylenic unsaturated bond is 50 to 90% by mass based on the whole composition, and further contains 0.5 to 3.0% by mass of a phosphoric acid (meth) acrylate compound as a part of the compound having an ethylenically unsaturated bond with respect to the whole composition, and is an active energy ray-curable composition characterized by being a varnish composition applied to the surface of a printed matter.

[0012] In the above active energy ray-curable composition, it is preferable that the vegetable oil is castor oil.

[0014] The present invention is also a method for manufacturing a printed matter, which comprises printing on a substrate to obtain a printed matter, applying the above active energy ray-curable composition to the surface of the printed matter, and then irradiating the surface of the printed matter with active energy rays to form a cured coating.

Effects of the Invention

[0016] According to the present invention, an active energy ray-curable composition is provided in which the biomass count is improved by adding vegetable oil and the cured coating has sufficient adhesion to the printed matter and the printing substrate.

Modes for Carrying Out the Invention

[0017] Hereinafter, an embodiment of the active energy ray-curable composition of the present invention, an embodiment of the method for manufacturing a printed matter of the present invention, and an embodiment of the method of the present invention for improving the adhesion of a film formed by curing an active energy ray-curable varnish composition to the surface of a printed matter will be described. In the following description, the active energy ray-curable composition of the present invention is appropriately abbreviated as "the composition of the present invention".

[0018] <Active energy ray-curable composition> The active energy ray-curable composition of the present invention has the ability to be cured by irradiation with active energy rays such as ultraviolet rays and electron beams, and can be preferably used as an overprint varnish or coating varnish for the surface of a printed matter after printing, an ink composition for flexographic printing, etc. As will be described later, the composition of the present invention contains a compound (such as a monomer or oligomer) having an ethylenically unsaturated bond, and radicals generated upon irradiation with active energy rays polymerize the compound having an ethylenically unsaturated bond to form a high molecular weight, thereby curing to form a film, that is, a coating film. Therefore, when the varnish composition that is sticky on the surface of the printed matter immediately after coating is irradiated with active energy rays, this varnish composition instantly becomes dry (tack-free). Since the cured film of the composition of the present invention adheres sufficiently to the surface of the printed matter or the printing substrate after printing, a practical cured film can be formed even when forming a thick film that tends to have poor adhesion in conventional products. For this reason, by using the composition of the present invention prepared as a low-viscosity type, a film having a film thickness sufficient to exhibit high gloss can be formed on the surface of the printed matter using a flexo coater, a gravure coater, or the like.

[0019] The objects to which the composition of the present invention is applied are not particularly limited, and examples thereof include printed matter obtained by means such as offset printing and the printed base material itself such as paper. As the printed matter obtained by offset printing, those printed with an oil-based offset printing ink composition or those printed with an active energy ray-curable offset printing ink composition may be used. When the composition of the present invention is used as a varnish composition applied to printed matter, it can protect the printed matter from scratches and impart a cosmetic property with high gloss to the printed matter.

[0020] Examples of the active energy ray used for curing the composition of the present invention include an electron beam and ultraviolet rays. Among these, from the viewpoints of the cost of the apparatus and ease of handling, ultraviolet rays are preferably exemplified as the active energy ray. And the wavelength of the ultraviolet rays may be appropriately determined according to the absorption wavelength of the photoinitiator to be used, and examples thereof include 400 nm or less. Examples of the ultraviolet irradiation apparatus for generating such ultraviolet rays include a metal halide lamp, a high-pressure mercury lamp, an excimer lamp filled with a rare gas, and an ultraviolet light-emitting diode (LED).

[0021] The composition of the present invention contains a compound having an ethylenically unsaturated bond, a photoinitiator, and vegetable oil or a fatty acid ester thereof, and further contains a phosphoric acid (meth) acrylate compound as a part of the compound having an ethylenically unsaturated bond. Hereinafter, each component will be described. In the present invention, the description of “(meth) acrylate” means acrylate and / or methacrylate, and the description of “(meth) acrylic acid” means acrylic acid and / or methacrylic acid.

[0022] [Compound having an ethylenically unsaturated bond] A compound having an ethylenically unsaturated bond is a component that polymerizes and increases in molecular weight by radicals generated by a photopolymerization initiator described later, and is a component called a monomer, an oligomer, or the like. Also, various polymers having an ethylenically unsaturated bond and having a higher molecular weight than oligomers are commercially available. Such polymers can also be crosslinked by the above monomers or oligomers, or by the polymers themselves to increase in molecular weight. Therefore, such polymers may be used as compounds having an ethylenically unsaturated bond together with the above monomers and oligomers.

[0023] A monomer has an ethylenically unsaturated bond and is a component that polymerizes and increases in molecular weight as described above. However, in the state before polymerization, it is often a liquid component with a relatively low molecular weight, and is also used as a solvent when dissolving the above polymer to form a varnish, or for the purpose of adjusting the viscosity of the composition. Examples of monomers include monofunctional monomers having one ethylenically unsaturated bond in the molecule, and bifunctional or higher-functional monomers having two or more ethylenically unsaturated bonds in the molecule. Bifunctional or higher-functional monomers can crosslink molecules when the varnish composition cures, and thus contribute to increasing the curing rate or forming a strong film. Monofunctional monomers, on the other hand, do not have the above crosslinking ability, but contribute to reducing the curing shrinkage associated with crosslinking. These monomers can be used in combination of various types as required.

[0024] Examples of monofunctional monomers include alkyl acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, octyl (meth)acrylate, dodecyl (meth)acrylate, (meth)acrylic acid, (meth)acrylate of ethylene oxide adduct, (meth)acrylate of propylene oxide adduct, isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, tricyclodecane monomethylol (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, hydroxypentyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-hydroxy-3-butoxypropyl (meth)acrylate, 2-hydroxy-3-methoxypropyl (meth)acrylate, diethylene glycol mono(meth)acrylate, triethylene glycol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate, dipropylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, glycerin mono(meth)acrylate, acryloyloxyethyl phthalate, 2-(meth)acryloyloxyethyl-2-hydroxyethyl phthalate, 2-(meth)acryloyloxypropyl phthalate, β-carboxyethyl (meth)acrylate, (meth)acrylic acid dimer, ω-carboxypolycaprolactone mono(meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, N-vinylpyrrolidone, N-vinylformamide, (meth)acryloylmorpholine, etc. These monofunctional monomers can be used alone or in combination of two or more.

[0025] Examples of monomers with two or more functional groups 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, butylene glycol di(meth)acrylate, pentyl glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, hydroxypivalyl hydroxypivalate di(meth)acrylate, hydroxypivalyl hydroxypivalate dicaprolactonate 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, 1,2 - decanediol 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 - dimethyl - 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, 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, 1,2-decanediol 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-pentanedi(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 2-methyl-2-propyl-1,3-propanediol di(meth)acrylate, 2,4-dimethyl-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-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 dicaprolactonate 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 dicaprolactonate di(meth)acrylate, bisphenol F tetraethylene oxide adduct dicaprolactonate di(meth)acrylate and other bifunctional monomers; glycerol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane tricaprolactonate tri(meth)acrylate, trimethylolethane tri(meth)acrylate, trimethylolhexane tri(meth)acrylate, trimethyloctane tri(meth)acrylate, pentaerythritol tri(meth)acrylate and other trifunctional monomers; trimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol tetracaprolactonate tetra(meth)acrylate, diglycerol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, ditrimethylolpropane tetracaprolactonate tetra(meth)acrylate, ditrimethylolethane tetra(meth)acrylate, ditrimethylolbutane tetra(meth)acrylate, ditrimethylolhexane tetra(meth)acrylate, ditrimethyloctane tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol hexa(meth)acrylate, tripentaerythritol hepta(meth)acrylate, tripentaerythritol octa(meth)acrylate, tripentaerythritol polyalkylene oxide hepta(meth)acrylate and other monomers with a functionality of 4 or more; etc. These bifunctional or higher-functional monomers can be used alone or in combination of two or more.

[0026] In addition, as a kind of monomer, there is epoxidized vegetable oil acrylate obtained by acrylate-modifying epoxidized vegetable oil. This is a compound obtained by ring-opening addition polymerization of (meth)acrylic acid to the epoxy group of epoxidized vegetable oil epoxidized with an oxidizing agent such as peracetic acid or perbenzoic acid at the double bond of unsaturated vegetable oil. Unsaturated vegetable oil refers to triglyceride in which at least one fatty acid has at least one carbon-carbon unsaturated bond, and examples thereof include linseed oil, linseed oil, perilla oil, camellia oil, olive oil, cocoa butter, kapok oil, kaya oil, mustard oil, kiri oil, kukui oil, walnut oil, castor oil, sesame oil, safflower oil, radish seed oil, soybean oil, chaulmoogra oil, camellia oil, corn oil, rapeseed oil, neem oil, bran oil, palm oil, castor oil, sunflower oil, grape seed oil, tung oil, pine seed oil, cottonseed oil, coconut oil, peanut oil, dehydrated castor oil, etc. Since this type of monomer is derived from vegetable oil, it helps to increase the amount of biomass component in the varnish composition. Various types of epoxidized vegetable oil acrylate are commercially available, and it may be used.

[0027] Oligomers are components that polymerize as described above to increase their molecular weight. Since they originally have a relatively high molecular weight, they are also used for the purpose of imparting appropriate viscosity and curability to the varnish composition. Examples of oligomers include epoxy-modified (meth)acrylates exemplified by esters of hydroxyl groups generated after ring-opening epoxy groups contained in epoxy compounds such as epoxy resins with acids or bases and (meth)acrylic acid, vegetable oil-modified polyfunctional (meth)acrylates exemplified by esters of hydroxyl groups generated after epoxidizing unsaturated bonds contained in vegetable oils and then ring-opening them with acids or bases and (meth)acrylic acid, rosin-modified epoxy acrylates, polyester-modified (meth)acrylates exemplified by esters of terminal hydroxyl groups of polycondensates of dibasic acids and diols and (meth)acrylic acid, polyether-modified (meth)acrylates exemplified by esters of terminal hydroxyl groups of polyether compounds and (meth)acrylic acid, urethane-modified (meth)acrylates exemplified by esters of terminal hydroxyl groups in condensates of polyisocyanate compounds and polyol compounds and (meth)acrylic acid, and the like. Such oligomers are commercially available and can be obtained, for example, under trade names such as the EBECRYL series manufactured by Daicel Cytec Co., Ltd., the CN and SR series manufactured by Sartomer Co., the ARONIX M-6000 series, 7000 series, 8000 series, ARONIX M-1100, ARONIX M-1200, ARONIX M-1600 manufactured by Toagosei Co., Ltd., and NK Oligo manufactured by Shin-Nakamura Chemical Co., Ltd. These oligomers can be used alone or in combination of two or more kinds.

[0028] Polymers having ethylenically unsaturated bonds are components that increase their molecular weight together with the above-mentioned monomers and oligomers. Since they have a large molecular weight before being irradiated with active energy rays, they are components useful for improving the coating film strength of the varnish composition. Such polymers are used, for example, in a state dissolved or dispersed in a monomer that is a low-viscosity liquid. Examples of polymers having ethylenically unsaturated bonds include polydiallyl phthalate, acrylic resins having unreacted unsaturated groups, acrylic-modified phenol resins, and the like.

[0029] In the composition, the content of the compound having an ethylenically unsaturated bond is preferably 50 to 90% by mass, more preferably 70 to 90% by mass. When the content of the compound having an ethylenically unsaturated bond is within the above range, good curability and a high biomass content can be achieved simultaneously. Further, the content of the polymer having an ethylenically unsaturated bond is preferably 0 to 50% by mass, more preferably 0 to 30% by mass, and even more preferably 0 to 20% by mass.

[0030] The composition of the present invention contains a phosphoric acid (meth) acrylate compound as a part of the compound having an ethylenically unsaturated bond. Next, the phosphoric acid (meth) acrylate compound will be described.

[0031] The phosphoric acid (meth) acrylate compound is a phosphoric acid ester compound having an acryloyl group or a methacryloyl group which is a substituent having an ethylenically unsaturated bond. That is, the phosphoric acid (meth) acrylate compound in the present invention may be any compound that contains an acryloyl group or a methacryloyl group and a phosphoric acid group in which at least one OH group forms an ester. As an example of such a compound, one represented by the following general formula (1) can be mentioned.

[0032]

Chemical formula

[0033] In the above general formula (1), R 1 is a hydrogen atom or a methyl group. R 2 is an alkylene group which may have a branch having 1 to 4 carbon atoms, and this alkylene group may further have a substituent. Examples of such an alkylene group include a methylene group, an ethylene group, a propylene group, an isopropylene group, a butylene group, etc., and among these, an ethylene group is preferably mentioned.

[0034] In the above general formula (1), x is an integer of 1 to 6, and y is 1 or 2. As x, an integer of 1 to 3 is preferably mentioned, and 1 or 2 is more preferably mentioned.

[0035] As the compound represented by the general formula (1) above, those represented by the following chemical formulas can be preferably exemplified.

[0036]

Chemical formula

[0037] (Meth)acrylate phosphate compounds are commercially available in various types, and it is also possible to use such commercially available products. Examples of such commercially available products include Light Ester P-1M and P-2M manufactured by Kyoeisha Chemical Co., Ltd., GENORAD40 manufactured by Rahn AG, SC1400 manufactured by Miramar, KAYAMER PM-2 and PM-21 manufactured by Nippon Kayaku Co., Ltd., and the like.

[0038] The content of the (meth)acrylate phosphate compound in the composition of the present invention is preferably 0.1 to 2% by mass, more preferably 0.5 to 2% by mass, based on the whole composition. When the content of the (meth)acrylate phosphate is 0.1% by mass or more based on the whole composition, the cured film exhibits sufficient adhesion to the surface of the printed matter or the printing substrate, which is preferable. When the content of the (meth)acrylate phosphate is 2% by mass or less based on the whole composition, blocking of the printed matter or the printing substrate having the cured film formed thereon can be suppressed, which is preferable.

[0039] [Photoinitiator] A photoinitiator is a component that generates radicals upon irradiation with ultraviolet rays, and the generated radicals polymerize the compound having the ethylenically unsaturated bond described above to cure the composition. The photoinitiator is not particularly limited as long as it generates radicals when irradiated with active energy rays.

[0040] Examples of the photoinitiator include benzophenone, diethylthiioxanthone, 2-methyl-1-(4-methylthio)phenyl-2-morpholinopropan-1-one, 4-benzoyl-4'-methyldiphenyl sulfide, 1-chloro-4-propoxythioxanthone, isopropylthioxanthone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, bis-2,6-dimethoxybenzoyl-2,4,4-trimethylpentylphosphine oxide, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2,2-dimethyl-2-hydroxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,4,6-trimethylbenzyl-diphenylphosphine oxide, 2-benzyl-2-dimethylamino-1-(morpholinophenyl)butan-1-one, and the like. Such photoinitiators are commercially available and can be obtained, for example, under the trade names Omnirad907, Omnirad369, Omnirad184, Omnirad379, Omnirad819, OmniradTPO, etc. from IGM Resins B.V. and under the trade name DETX, etc. from Lamberti. These photoinitiators can be used alone or in combination of two or more.

[0041] The content of the photoinitiator in the composition is preferably 3 to 30% by mass, more preferably 2 to 15% by mass, and even more preferably 2 to 13% by mass. When the content of the photoinitiator in the composition is within the above range, it is preferable because sufficient curability of the composition, good internal curability, and cost can be balanced.

[0042] [Vegetable oil or its fatty acid ester] The composition of the present invention contains vegetable oil or its fatty acid ester. These are renewable materials and contribute to increasing the biomass count in the composition of the present invention. As already described, these materials reduce the adhesion of the printed matter or the substrate surface of the cured film formed from the composition, but in the composition of the present invention, this problem is solved by including the above (meth)acrylate phosphate.

[0043] Examples of the vegetable oil include sesame oil, linseed oil, perilla oil, camellia oil, olive oil, cocoa butter, kapok oil, kaya oil, mustard oil, candlenut oil, kukui oil, walnut oil, castor oil, sesame oil, safflower oil, radish seed oil, soybean oil, chaulmoogra oil, camellia oil, corn oil, rapeseed oil, neem oil, bran oil, palm oil, castor oil, sunflower oil, grape seed oil, tung oil, pine seed oil, cottonseed oil, coconut oil, peanut oil, dehydrated castor oil, etc. Further, these fatty acid esters are compounds obtained by subjecting these vegetable oils to an alcoholysis reaction by allowing alcohol to act on them. Among these vegetable oils or their fatty acid esters, castor oil is preferably mentioned from the viewpoint of compatibility.

[0044] The content of the vegetable oil or its fatty acid ester in the composition of the present invention can be about 3 to 30% by mass, more preferably about 3 to 20% by mass, and even more preferably about 3 to 10% by mass.

[0045] [Other components] In addition to the above components, other components can be added to the composition of the present invention as needed. Examples of such components include polymerization inhibitors, coloring pigments, inert resins, waxes such as polyethylene wax, olefin wax, and Fischer-Tropsch wax, leveling agents, defoaming agents, etc.

[0046] Examples of the polymerization inhibitor include phenolic compounds such as butylhydroxytoluene, tocopherol acetate, nitrosoamine, benzotriazole, and hindered amine. Among them, butylhydroxytoluene can be more preferably exemplified. By adding such a polymerization inhibitor to the composition, it is possible to suppress the progress of the polymerization reaction during storage and the thickening of the varnish composition. The content of the polymerization inhibitor in the composition can be exemplified as about 0.01 to 1% by mass.

[0047] The coloring pigment is added when the composition of the present invention is used as an ink composition. Examples of such coloring pigments include those known in the field of ink compositions without particular limitation.

[0048] The inert resin is a polymer having no ethylenically unsaturated bond and is a component not involved in the formation of a cured film upon irradiation with active energy rays. By adding such an inert resin to the composition of the present invention, the viscoelasticity of the composition can be adjusted, and the effect of improving the adhesion of the cured film due to the reduction of curing shrinkage can be achieved. Examples of the inert resin include various resins that have been conventionally used for this type of composition application, but those having compatibility with the above monomers and oligomers are preferred, and styrene-acrylic resins, acrylic resins, alkyd resins, rosin-modified phenolic resins, rosin-modified alkyd resins, rosin-modified maleic acid resins, rosin-modified petroleum resins, rosin ester resins, petroleum resin-modified phenolic resins, vegetable oil-modified alkyd resins, petroleum resins, etc. can be mentioned.

[0049] When adding an inert resin to the composition of the present invention, its content in the composition is preferably 1 to 30% by mass, more preferably 1 to 20% by mass, and even more preferably 1 to 10% by mass. When the content of the resin component is within the above range, it is possible to impart appropriate viscoelasticity to the ink composition to suppress the occurrence of misting, etc., and to ensure good curability of the ink composition, which is preferable.

[0050] The composition of the present invention may be a varnish composition that does not contain a coloring pigment, or may be an ink composition that contains a coloring pigment.

[0051] When the composition of the present invention is a varnish composition, the varnish composition may be an OP varnish composition applied to an offset printing machine, or may be a coating varnish composition applied to various coaters. When the composition of the present invention is an OP varnish composition, an example of its viscosity is that the value at 25 °C measured by a rotational viscometer is 10 to 70 Pa·s, but it is not particularly limited. When the composition of the present invention is a coating varnish composition, an example of its viscosity is that the flow-down time measured by a Ford cup viscometer No. 4 at 25 °C is about 30 to 80 seconds, but it is not particularly limited.

[0052] When the composition of the present invention is an ink composition, the ink composition may be an ink composition for offset printing or an ink composition for flexographic printing. When the ink composition is for offset printing, an example of its viscosity is that the value at 25 °C measured by a rotational viscometer is 10 to 70 Pa·s, but it is not particularly limited. When the ink composition is for flexographic printing, an example of its viscosity is that the flow-down time measured by a Ford cup viscometer No. 4 at 25 °C is about 30 to 80 seconds, but it is not particularly limited.

[0053] <Method for manufacturing a printed matter> Next, an embodiment of the method for manufacturing a printed matter of the present invention will be described. The method for manufacturing a printed matter of the present invention is characterized in that a printed matter is obtained by performing printing on a substrate, the active energy ray-curable composition of the present invention is applied to the surface of the printed matter, and then an active energy ray is irradiated onto the surface of the printed matter to form a cured film.

[0054] As described above, the composition of the present invention realizes a high biomass count by containing vegetable oil or its fatty acid ester, while solving the problem of reduced adhesion of the cured film associated with the inclusion of these components by including (meth)acrylate phosphate. Therefore, the printed matter obtained by the method for producing a printed matter of the present invention exhibits high gloss and has a cured film with good adhesion on the surface.

[0055] The substrate on which printing is performed is not particularly limited, and examples thereof without particular limitation include those commonly used in ordinary printing, such as paper, plastic film, synthetic paper, etc. Also, examples of the ink composition used for printing include an oil-based offset printing ink composition and an active energy ray-curable offset ink composition.

[0056] When applying the composition of the present invention to the printed matter after printing, the composition of the present invention may be applied to the surface of the printed matter in a wet-on-wet manner. As means for applying the composition of the present invention, known means can be cited without particular limitation. Examples of such means include a method using a gravure coater and a method using a flexo coater.

[0057] <Method for improving the adhesion of the film formed by curing an active energy ray-curable varnish composition to the surface of a printed matter> Next, an embodiment of a method for improving the adhesion of the film formed by curing the active energy ray-curable varnish composition of the present invention to the surface of a printed matter will be described. The method of the present invention is characterized in that, in a varnish composition that forms a cured film by irradiation with active energy rays after being applied to the surface of a printed matter, a (meth)acrylate phosphate compound is added to the composition.

[0058] As described above, the composition of the present invention that can be used as an active energy ray-curable varnish composition has a reduced adhesion of its cured film to the printed matter surface due to the addition of vegetable oil or its fatty acid ester, but this adhesion is compensated by the addition of (meth)acrylate phosphate. The present invention uses this as a "method for improving the adhesion of the film formed by curing an active energy ray-curable varnish composition to the printed matter surface". Since the details have already been described, the description here is omitted.

Examples

[0059] Hereinafter, the composition of the present invention will be described in more detail by showing examples, but the present invention is not limited to the following examples at all.

[0060] Varnish compositions of Examples 1 to 8, Comparative Examples 1 to 2, and Reference Example 1 were prepared with the formulations described in Tables 1 and 2. The amounts of formulation in Tables 1 and 2 are in parts by mass. When preparing the varnish composition, each material was mixed at the ratios described in Tables 1 and 2 and stirred until uniform. Note that Reference Example 1 does not attempt to increase the biomass count by adding vegetable oil (castor oil), and is a conventional type of varnish composition.

[0061] The explanations of each material described in Tables 1 and 2 are as follows. "TMPTA": Trimethylolpropane triacrylate "3EO-TMPTA": TMPTA having 3 ethylene oxide (EO) units in one molecule "4EO-bisphenol A diacrylate": Bisphenol A diacrylate having 4 EO units in one molecule "Amine-modified acrylate": Manufactured by Sartomer, amine-modified acrylate (trade name: CN371) "Epoxy acrylate oligomer": Manufactured by Sartomer, epoxy acrylate oligomer (trade name CN104) "Acrylic polymer": A copolymer of styrene / dimethylaminoethyl methacrylate (50 / 50), weight average molecular weight 10000 "Methacrylate Phosphate 1": Manufactured by Kyoeisha Chemical Co., Ltd., Methacrylate Phosphate (Trade name: Light Ester P-2M) "Methacrylate Phosphate 2": Manufactured by Rahn AG, Methacrylate Phosphate (Trade name: GENORAD40) "Wax": Manufactured by Sasol, Fischer-Tropsch Wax (Trade name: Zasol Wax Spray30) "Leveling Agent": Manufactured by BYK-Chemie GmbH, BYK-333 "Defoaming Agent": Manufactured by BYK-Chemie GmbH, BYK-066N

[0062] [Preparation of Evaluation Print] On the evaluation paper (manufactured by Oji Materia Co., Ltd., UF-coated), UV ink (black ink, manufactured by Sakata Inx Corporation, trade name: Dream Cure) was applied at 0.125 cc / 204 cm 2 using a RI color developing machine (manufactured by Meisei Seisakusho Co., Ltd.). Subsequently, one of the active energy ray curable compositions of each example, comparative example, or reference example was applied at 0.35 cc / 204 cm 2 on the above color developed surface using a RI color developing machine. An evaluation print was prepared by passing the above color developed material twice at a speed of 130 m / min and an irradiation intensity of 120 W / cm using a conveyor type ultraviolet irradiation device equipped with a high-pressure mercury lamp.

[0063] [Evaluation of Curability] The presence or absence of scratches when the evaluation print obtained by the above procedure was scratched with a fingernail was visually evaluated. The evaluation criteria were as follows, and the results are shown in the "Curability" columns of Tables 1 and 2. ○: No scratches occurred ×: Scratches occurred

[0064] [Evaluation of Adhesion] For the evaluation print obtained by the above procedure, a peel test using cellophane tape was performed immediately after curing and after leaving it at room temperature for 24 hours after curing, and the state of the coating film was visually observed for evaluation. The evaluation criteria were as follows, and the results are shown in the "Adhesion (immediately)" column or "Adhesion (after 24 hours)" column of Tables 1 and 2, respectively. ○: No peeling between the paper and the varnish layer, or peeling occurs together with the paper △: Slight peeling exists between the paper and the varnish layer ×: Most of the peeling occurs between the paper and the varnish layer

[0065] [Evaluation of abrasion resistance] The state of the coating film was visually observed when the varnish surfaces of the printed matter obtained by the above procedure were rubbed 500 times with a load of 1 kg using a Kagaku-Shinkou type abrasion fastness tester. The evaluation criteria are as follows, and the results are shown in the "Abrasion resistance" columns of Tables 1 and 2. ○: No rubbing ×: Rubbing occurred

[0066] [Evaluation of blocking resistance] The varnish surfaces of the printed matter obtained by the above procedure were made to face each other in a contact state, and after leaving it for 24 hours in an environment of 50 °C and 80% RH with a load of 1 kg applied thereto, the presence or absence of blocking was visually evaluated. The evaluation criteria are as follows, and the results are shown in the "Blocking resistance" columns of Tables 1 and 2. ○: No peeling occurs from either the ink layer or the varnish layer ×: Peeling occurred from the ink layer or the varnish layer

[0067]

Table 1

[0068]

Table 2

[0069] As can be understood from Tables 1 and 2, by adding the (meth)acrylate phosphate compound, even under the condition of adding vegetable oil, the effect of improving the adhesion is obtained, and the problems of the present invention are solved. Although it has nothing to do with the problems of the present invention, focusing on the blocking resistance, since the blocking resistance decreases when the addition amount of the (meth)acrylate phosphate compound exceeds 2% by mass, it can be seen that the addition amount of the (meth)acrylate phosphate compound is preferably 2% by mass or less.

Claims

1. An active energy ray-curable composition comprising a compound having an ethylenically unsaturated bond, a photoinitiator, and a vegetable oil or a fatty acid ester thereof, wherein the content of the compound having an ethylenically unsaturated bond is 50 to 90% by mass based on the whole composition, and further containing 0.5 to 3.0% by mass of a (meth)acrylate phosphate compound as part of the compound having an ethylenically unsaturated bond based on the whole composition, and being a varnish composition applied to the surface of a printed matter.

2. The active energy ray-curable composition according to claim 1, wherein the vegetable oil is castor oil.

3. A method for producing a printed matter, comprising printing on a substrate to obtain a printed matter, applying the active energy ray-curable composition according to claim 1 or 2 to the surface of the printed matter, and then irradiating the surface of the printed matter with active energy rays to form a cured film.

Images