JP6893439B2 - Active energy ray-curable offset ink composition and printed matter using it - Google Patents

Description

The present invention is an active energy ray-curable offset ink composition characterized by having excellent curability under active energy ray conditions and maintaining excellent printability and print quality for printing package inks such as paper containers. Regarding. Further, the present invention relates to a printed matter using the composition.

UV-curable offset inks that cure under active energy ray conditions are widely used in the field of package printing for food packaging such as toys and paper containers because of the convenience of instant drying characteristics.

Due to the convenience of instant drying characteristics, the switch from conventional oxidative polymerization type oil-based inks to ultraviolet curable inks is progressing, especially in commercial printing, and there are various points such as handling, printability, and quality of printed matter. Is required to have the same performance as oil-based ink. Above all, it is required to improve the "pot rising property", which is a phenomenon that tends to occur in ultraviolet curable ink, in which the ink flow is stagnant in the ink pot of the printing machine and the ink is not supplied to the pot roll. The potting property is due to the fluidity of the ink, and the UV curable offset ink using the commonly used diallyl phthalate (DAP) resin has stain resistance during printing, density stability, etc. Although it has excellent printability, it tends to be difficult to obtain fluidity.

In addition, DPHA represented by dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate mixture, which are acrylic monomers useful in terms of curability, are widely used, but their viscosity is higher than that of other polyfunctional monomers. Since it is high and the ratio of the resin in the ink composition is reduced, the color pigment used in combination is not sufficiently coated, and it is difficult to obtain fluidity, which is a problem. Patent Document 1 can be mentioned, for example, as a combination of the diallyl phthalate (DAP) resin and DPHA.
Since the fluidity of the ink affects the leveling property of the ink, the glossiness of the printed matter also decreases as the fluidity of the ink decreases.

JP 2016-079211

An object of the present invention is to provide an active energy ray-curable offset ink composition which is excellent in ink fluidity and density stability during printing and can obtain high gloss in the obtained printed matter.

As a result of intensive studies to solve the above problems, the present inventors are characterized by containing specific active energy ray-curable monomer (A), resin (B), and coloring pigment (C). We found that the active energy ray-curable offset ink composition is excellent in ink fluidity and density stability during printing, and the obtained printed matter is an active energy ray-curable offset ink composition that can obtain high gloss. The present invention has been completed.

That is, the present invention is characterized in that the active energy ray-curable monomer (A), the resin (B), and the coloring pigment (C) having an acid value of 1.0 to 10.0 mgKOH / g are essential components. With respect to an active energy ray-curable composition.

Furthermore, the present invention relates to an active energy ray-curable offset ink composition in which the active energy ray-curable monomer (A) is a polyfunctional acrylate (A1).

Further, in the present invention, the polyfunctional acrylate (A1) is a mixture of dipentaerythritol penta (meth) taacrylate and dipentaerythritol hexa (meth) acrylate (DPHA), ditrimethylolpropane tetraacrylate (DTMPTA), and ethylene oxide modification. Concerning an active energy ray-curable offset ink composition that is one or more selected from the group consisting of trimethylolpropane triacrylate (EOTMPTA), propylene oxide-modified trimethylolpropane triacrylate (POTMPTA), and trimethylolpropane triacrylate (TMPTA). ..

Furthermore, the present invention relates to an active energy ray-curable offset ink composition in which the resin (B) is a urethane (meth) acrylate resin (B1) and / or a diallyl phthalate resin (B2).

Further, in the present invention, the urethane (meth) acrylate resin (B1) is an active energy ray-curable offset ink composition using an aromatic polyisocyanate (a) and a hydroxyl group-containing mono (meth) acrylate (b) as essential raw materials. Regarding.

Furthermore, the present invention relates to an active energy ray-curable offset ink composition in which the urethane (meth) acrylate resin (B1) further contains a polyol (c) as an essential raw material.

Furthermore, the present invention relates to an active energy ray-curable offset ink composition in which the urethane (meth) acrylate resin (B1) has a weight average molecular weight in the range of 3,000 to 40,000.

Furthermore, the present invention relates to an active energy ray-curable offset ink composition in which the pigment is carbon black.

The present invention further relates to a printed matter printed by using the active energy ray-curable printing ink composition.

With the active energy ray-curable offset ink composition of the present invention, it is possible to obtain an active energy ray-curable offset ink composition which is excellent in ink fluidity and density stability during printing and can obtain high gloss in the obtained printed matter. Can be done.

An object of the present invention is to use an active energy ray-curable monomer (A), a resin (B), and a coloring pigment (C) having an acid value of 1.0 to 10.0 mgKOH / g as essential components. It produces the effect of the invention.

As the active energy ray-curable monomer (A) used in the present invention, an acid value of 1.0 to 10.0 mgKOH / g is essential. In the present invention, "(meth) acrylic" is a general term for acrylic and methacryl.

Examples of the (meth) acrylic monomer include unsaturated carboxylic acids such as acrylic acid and methacrylic acid or esters thereof, such as alkyl-, cycloalkyl-, alkyl halides, alkoxyalkyl-, hydroxyalkyl-, and aminoalkyl-. Allyl-, glycidyl-, benzyl-, phenoxy- (meth) acrylate, alkylene glycol, mono or di (meth) acrylate of polyoxyalkylene glycol, trimethylpropantri (meth) acrylate, pentaerythritol tetra (meth) acrylate, etc. Allyl compounds such as (meth) acrylamide or derivatives thereof, such as mono- or di-substituted (meth) acrylamides with alkyl or hydroxyalkyl groups, diacetone (meth) acrylamides, N, N'-alkylenebis (meth) acrylamides, etc. For example, allyl alcohol, allyl isocyanate, diallyl phthalate, triallyl isocyanurate and the like can be mentioned.

Other examples of the (meth) acrylic monomer include polyethylene glycol (n is 3 or more and about 14 or less) having an ethylene glycol unit in the molecule, di (meth) acrylate, and phenol EO modified (n is 3 or more). (Approximately 14 or less) (meth) acrylate, 2-hydroxyethyl (meth) acrylate having a hydroxyl group in the molecule, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, pentaerythritol tetra (meth) Examples thereof include acrylate and monohydroxyethyl phthalate (meth) acrylate.

These (meth) acrylic monomers may be used alone or in combination of two or more.

Particularly suitable (meth) acrylic monomers for the composition include, for example, methyl, ethyl, propyl, butyl, amyl, 2-ethylhexyl, isooctyl, nonyl, dodecyl, hexadecyl, octadecyl, cyclohexyl, benzyl, methoxyethyl, butoxyethyl, (Meta) acrylates having substituents such as phenoxyethyl, nonylphenoxyethyl, glycidyl, dimethylaminoethyl, diethylaminoethyl, isobornyl, dicyclopentanyl, dicyclopentenyl, dicyclopentenyloxyethyl, ω-carboxy-polycaprolactone Monofunctional monomers such as monoacrylate, monohydroxyethyl phthalate acrylate, 2-hydroxy-3-phenoxypropyl acrylate, vinylpyrrolidone, acryloylmorpholin, N-vinylformamide, etc.
1,3-butylene glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,8-octanediol, Di (meth) acrylates such as 1,9-nonanediol, tricyclodecanedimethanol, ethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, and tris (2-hydroxyethyl) isocyanurate. Di (meth) acrylate, di (meth) acrylate of diol obtained by adding 4 mol or more of ethylene oxide or propylene oxide to 1 mol of di (meth) acrylate, 2- (2-vinyloxyethoxy) ethyl (meth) acrylate, and opentyl glycol. , Di (meth) acrylate of diol obtained by adding 2 mol of ethylene oxide or propylene oxide to 1 mol of bisphenol A, and triol obtained by adding 3 mol or more of ethylene oxide or propylene oxide to 1 mol of trimethylolpropane. Di or tri (meth) acrylate, di (meth) acrylate of diol obtained by adding 4 mol or more of ethylene oxide or propylene oxide to 1 mol of bisphenol A, trimethylpropantri (meth) acrylate, pentaerythritol tri (meth). Examples thereof include polyfunctional monomers such as acrylate, poly (meth) acrylate of dipentaerythritol, ethylene oxide-modified phosphoric acid (meth) acrylate, and ethylene oxide-modified alkyl phosphate (meth) acrylate. These can be used in combination of two or more types.
Further, as the active energy ray-curable monomer (A), a polyfunctional acrylate (A1) is more preferable.

The polyfunctional acrylate (A1), which is the active energy ray-curable monomer (A) used in the present invention, requires an acid value in the range of 1.0 to 10.0 mgKOH / g and is excellent in curability. Erislitol penta (meth) acrylate and dipentaerythritol hexa (meth) acrylate mixture (DPHA), ditrimethylolpropane tetraacrylate (DTMPTA), ethylene oxide-modified trimethylolpropane triacrylate (EOTMPTA), propylene oxide-modified trimethylolpropane triacrylate (DPHA) POTMPTA) and trimethylolpropane triacrylate (TMPTA) are more preferred. These may be used alone or in combination of two or more. Of these, a mixture of dipentaerythritol hexa (meth) acrylate and dipentaerythritol penta (meth) acrylate (DPHA) is most preferable.
The acid value is preferably 1.0 to 10.0 mgKOH / g, more preferably 1.0 to 5.0 mgKOH / g, and even more preferably 1.0 to 2.0 mgKOH / g.

Regarding the dipentaerythritol penta (meth) acrylate which is the pentafunctional polymerizable acrylate monomer and the dipentaerythritol hexa (meth) acrylate which is the hexafunctional polymerizable acrylate monomer, the amount used is 10% by mass or more based on the total amount of the ink. Is preferable. Normally, dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate are manufactured and sold as a single substance or a mixture, and the product names are "DPHA (manufactured by Sartmer)", "Aronix M-400 (manufactured by Toagosei)" and " Aronix M-402 (manufactured by Toagosei Co., Ltd.) "Aronix M-403 (manufactured by Toagosei Co., Ltd.)" "Aronix M-404 (manufactured by Toagosei Co., Ltd.)" "Aronix M-405 (manufactured by Toagosei Co., Ltd.)" "Aronix M -406 (manufactured by Toagosei Co., Ltd.) "" LUMICURE DPA-600T (manufactured by Zhangjiagang Toa Oil Aisei Chemical Co., Ltd.) "" Kayarad DPHA (manufactured by Nippon Kayaku Co., Ltd.) "" SR399 (manufactured by Sartmer) "" MIRAMER M600 (MIWON) Any of them can be preferably used as long as they are within the scope of the present invention.

As the resin (B) used in the present invention, various binder resins can be used. The binder resin refers to all resins having appropriate pigment affinity and dispersibility and having the rheological properties required for printing inks and the like. For example, examples of the non-reactive resin include diallyl phthalate resin and diallyl iso. Phthalate resin, epoxy resin, polyurethane resin, polyester resin, petroleum resin, rosin ester resin, poly (meth) acrylic acid ester, cellulose derivative, vinyl chloride-vinyl acetate copolymer, polyamide resin, polyvinyl acetal resin, butadiene-acrylic nitrile A copolymer or the like can be mentioned, or an epoxy acrylate compound, a urethane (meth) acrylate compound, a polyester (meth) acrylate compound or the like having at least one polymerizable group in the resin molecule can also be used. These binder resin compounds may be used alone or in combination of any one or more. Of these, urethane (meth) acrylate resin (B1) and / or diallyl phthalate resin (B2) are more preferable.

The urethane (meth) acrylate resin (B1) that can be used in the active energy ray-curable offset ink composition of the present invention contains an aromatic polyisocyanate (a) and a hydroxyl group-containing mono (meth) acrylate (b) as essential raw materials. It is desirable that the composition is an active energy ray-curable offset ink composition.
Among them, the ratio of the latter hydroxyl group (b') to the isocyanate group (a') of the former aromatic polyisocyanate (a) [(b') / (a')] is 0.99 to 0.40. The one reacted with is more preferable.

Further, as the urethane (meth) acrylate resin (B1) used in the present invention, the urethane (meth) having a high functional group concentration obtained by further reacting the obtained reaction product with the polyol (c) is then used. It is more preferable that it is an acrylate resin.

Examples of the aromatic polyisocyanate (a) include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, diphenylmethane-4,4-diisocyanate, and 1,5-naphthalene. Examples thereof include diisocyanate compounds such as diisocyanate; polyfunctional polyisocyanate compounds containing components having three or more isocyanate groups per molecule, such as polymethylene polyphenyl polyisocyanate and adducts of these isocyanate compounds and polyfunctional alcohols. .. These polyfunctional aromatic isocyanates may be used alone or in combination of two or more.

Among these, a polyfunctional polyisocyanate compound containing a component having three or more isocyanate groups per molecule (a component having three or more functionalities) is particularly preferable because a more excellent UV curable ink can be designed. Is preferably contained in a proportion of 30% by mass or more of trifunctional or higher functional components. Examples of the aromatic polyisocyanate containing such trifunctional or higher functional components include polymethylene polyphenyl polyisocyanate, and polymethylene polyphenyl polyisocyanate having a viscosity of 100 to 700 mPa · s is more preferable. Here, the viscosity is a value measured with an E-type viscometer (25 ° C.).

Examples of the hydroxyl group-containing mono (meth) acrylate (b) to be reacted with the aromatic polyisocyanate (a) include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl acrylate, and hydroxyethyl vinyl ether. Hydroxyl-containing (meth) acrylate; Examples thereof include an ethylene oxide adduct of the hydroxyl group-containing (meth) acrylate, a propylene oxide adduct of the hydroxyl group-containing (meth) acrylate, a tetramethylene glycol adduct, and a lactone adduct. These hydroxyl group-containing mono (meth) acrylates (b) may be used alone or in combination of two or more. Among these, hydroxyethyl acrylate and hydroxypropyl acrylate are particularly preferable.

As a method for reacting the aromatic polyisocyanate (a) with the hydroxyl group-containing mono (meth) acrylate (b), an aromatic polyisocyanate (a) and, if necessary, a known and commonly used urethanization catalyst are added. Examples thereof include a method of heating to 20 to 120 ° C. and continuously or intermittently adding a predetermined amount of the hydroxyl group-containing mono (meth) acrylate (b) to the reaction system for reaction.

Next, the reaction product thus obtained is further reacted with the polyol (c) to obtain a urethane (meth) acrylate resin (B1) having a higher functional group concentration. Here, the polyol (c) preferably has an aliphatic polyhydric alcohol having a molecular weight in the range of 90 to 400 from the viewpoint of curability and printability. That is, when the molecular weight is less than 90, the effect of improving the appropriate offset printing suitability is reduced, while when the molecular weight is more than 400, the finally obtained urethane (meth) acrylate resin (B1) is obtained. The functional group concentration of the resin becomes low, and the curability tends to decrease.

From this point of view, specifically, bifunctional polyols such as neopentyl glycol, 1,3-butanediol, 1,4-butanediol and tripropylene glycol; and trifunctional polyols such as glycerin and trimethylolpropane. Tetrafunctional polyols such as pentaerythritol and ditrimethylolpropane; Hexfunctional polyols such as dipentaerythritol; and ethylene oxide adducts of the trifunctional polyols (addition of 1 to 4 moles per molecule on average), said trifunctional A propylene oxide adduct of a type polyol (addition of 1 to 4 mol on average per molecule), a 1,3-butanediol adduct of the trifunctional polyol (addition of 1 to 2 mol on average per molecule), the tetrafunctional polyol. Examples of the ethylene oxide adduct (addition of 1 to 3 mol per molecule on average), the ethylene oxide adduct of the hexafunctional polyol (addition of 1 to 3 mol per molecule on average), and the like. These polyols (c) may be used alone or in combination of two or more. Among these, urethane (meth) acrylate resin (B1) having an appropriate branched structure can be obtained, and trifunctional polyols such as glycerin and trimethylolpropane, neo, can exhibit excellent offset printability and curability. Pentyl glycol, 1,6-hexanediol, and tripropylene glycol are preferable, and trifunctional polyols such as glycerin and trimethylolpropane are particularly preferable because they are excellent in printability.

Here, the urethane (meth) acrylate resin (B1) finally obtained by adding the polyol (c) at a ratio of 1 to 15% by mass with respect to the total mass of the components (a) to (c). It is preferable because the concentration of the (meth) acryloyl group in the medium is increased and the curability and printability are dramatically improved.

The urethane (meth) acrylate resin (B1) thus obtained must have a weight average molecular weight (Mw) in the range of 3,000 to 40,000 in terms of fluidity, misting property, and printability. It is preferable because it provides an excellent printing ink.

In the present invention, the weight average molecular weight (Mw) is a value measured by gel permeation chromatography (GPC) under the following conditions.

Measuring device; HLC-8220GPC manufactured by Tosoh Corporation
Column; TSK-GUARDCOLUMN SuperHZ-L manufactured by Tosoh Corporation
+ TSK-GEL SuperHZM-M x 4 manufactured by Tosoh Corporation
Detector; RI (Differential Refractometer)
Data processing; Multi-station GPC-8020modelII manufactured by Tosoh Corporation
Measurement conditions; column temperature 40 ° C
Solvent tetrahydrofuran
Flow velocity 0.35 ml / min Standard; Monodisperse polystyrene sample; 0.2 mass% tetrahydrofuran solution in terms of resin solid content filtered through a microfilter (100 μl)

Examples of the diallyl phthalate resin (B2) used in the active energy ray-curable offset ink composition of the present invention include a polybasic acid such as phthalic anhydride as a main agent, an allyl alcohol as a curing agent, a cross-linking agent and the like. Examples thereof include compositions containing. Examples of the cross-linking agent include styrene and vinyl acetate.
The diallyl phthalate resin (B2) is particularly useful for imparting excellent emulsion resistance and long-run printability.
Specific examples of the diallyl phthalate resin (B2) include Daiso Dup and Daiso Isodap (both manufactured by Daiso Co., Ltd.).
In the active energy ray-curable offset ink composition of the present invention, the content of the diallyl phthalate resin (B2) is preferably 5 to 25% by mass, more preferably 10 to 20% by mass, based on the total amount of the composition. ..
If the content of the diallyl phthalate resin (B2) is less than 5% by mass, sufficient ink viscosity cannot be obtained, and problems such as dot gain and stains may occur in printing. On the other hand, if the content of the diallyl phthalate resin (B2) exceeds 25% by mass, the fluidity of the ink is significantly impaired, and sufficient printability may not be imparted.

As described above, the active energy rays that cure the active energy ray-curable offset ink composition of the present invention include ionized radiation such as ultraviolet rays, electron beams, α rays, β rays, and γ rays. Examples of the energy source or curing device include a sterilizing lamp, an ultraviolet fluorescent lamp, an ultraviolet light emitting diode (UV-LED), a carbon arc, a xenon lamp, a high-pressure mercury lamp for copying, a medium-pressure or high-pressure mercury lamp, an ultra-high-pressure mercury lamp, and no electrode. Examples thereof include a lamp, a metal halide lamp, ultraviolet rays using natural light as a light source, or an electron beam using a scanning type or curtain type electron beam accelerator.

Next, examples of the photopolymerization initiator used when the active energy ray-curable offset ink composition of the present invention is an ultraviolet curable composition include an intramolecular cleavage type photopolymerization initiator and a hydrogen abstraction type photopolymerization initiator. Be done. Examples of the intramolecular cleavage type photopolymerization initiator include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethylketal, 1- (4-isopropylphenyl) -2-hydroxy. -2-Methylpropan-1-one, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl-phenylketone, 2-hydroxy-1-{4- [4 -(2-Hydroxy-2-methyl-propionyl) -benzyl] -phenyl} -2-methyl-propan-1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2,2- Acetphenone compounds such as diethoxy-1,2-diphenylethane-1-one; 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], 1- [9-ethyl-6- (2-) Methylbenzoyl) -9H-carbazole-3-yl]-, 1- (O-acetyloxime) and other oxime compounds, 3,6-bis (2-methyl-2-morpholinopropanol) -9-butylcarbazole Carbazole compounds such as benzoin, benzoin methyl ether, benzoin isopropyl ether and the like; 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butane-1-one, 2- (dimethylamino) ) -2- (4-Methylbenzyl) -1- (4-morpholinophenyl) butane-1-one, 2-methyl-2-morpholino ((4-methylthio) phenyl) propan-1-one, 2-benzyl Aminoalkylphenone compounds such as -2-dimethylamino-1- (4-morpholinophenyl) -butanone; bis (2,4,6-trimethylbenzoyl) -phenylphosphenyl oxide, 2,4,6-trimethylbenzoyldiphenyl Acylphosphine oxide compounds such as phosphine oxide and bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphinoxide; benzyl, methylphenylglioxyester and the like can be mentioned.

On the other hand, examples of the hydrogen abstraction type photopolymerization initiator include benzophenone, methyl-4-phenylbenzophenone o-benzoylbenzoate, 4,4'-dichlorobenzophenone, and the like.
Hydroxybenzophenone, 4-benzoyl-4'-methyl-diphenylsulfide,
Benzophenone compounds such as acrylicized benzophenone, 3,3', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, 3,3'-dimethyl-4-methoxybenzophenone; 2-isopropylthioxanthone, 2,4- Thioxanthone compounds such as dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone; aminobenzophenone compounds such as 4,4'-bisdimethylaminobenzophenone, 4,4'-bisdiethylaminobenzophenone; and others 10- Examples thereof include butyl-2-chloroacrydone, 2-ethylanthraquinone, 9,10-phenanthrenequinone, and camphorquinone. These photopolymerization initiators can be used alone or in combination of two or more. Among these, an aminoalkylphenone-based compound is particularly preferable from the viewpoint of excellent curability, and particularly when a UV-LED light source that generates ultraviolet rays having an emission peak wavelength in the range of 350 to 420 nm is used as an active energy radiation source. Is preferable in combination with an aminoalkylphenone-based compound, an acylphosphine oxide-based compound, and an aminobenzophenone-based compound from the viewpoint of excellent curability.

The amount of these polymerization initiators used is preferably in the range of 1 to 20% by mass as the total amount used with respect to 100% by mass of the non-volatile component in the active energy ray-curable offset ink composition of the present invention. .. That is, when the total amount of the polymerization initiator used is 1% by mass or more, good curability can be obtained, and when it is 20% by mass or less, the unreacted polymerization initiator remains in the cured product. It is possible to avoid problems such as migration, deterioration of physical properties such as solvent resistance and weather resistance due to the above. From the viewpoint of improving the balance of these performances, in particular, the total amount used is in the range of 3 to 15% by mass with respect to 100% by mass of the non-volatile component in the active energy ray-curable ink composition of the present invention. Is more preferable. However, when an electron beam is used as the active energy ray, the use of these photopolymerization initiators is not essential in principle.

Further, the curability can be further improved by using a photosensitizer in addition to the above-mentioned polymerization initiator. Examples of such a photosensitizer include amine compounds such as aliphatic amines, ureas such as o-tolylthiourea, sulfur compounds such as sodium diethyldithiophosphate and s-benzylisothiuronium-p-toluenesulfonate. Be done. The amount of these photosensitizers used is 1 as the total amount used with respect to 100% by mass of the non-volatile component in the active energy ray-curable ink composition of the present invention from the viewpoint that the effect of improving the curability is good. It is preferably in the range of about 20% by mass.

In the active energy ray-curable offset ink composition of the present invention, wax can be added for the purpose of improving curability. Examples of the wax include paraffin wax, carnauba wax, mitsuro, microcrystallin wax, polyethylene wax, polyethylene oxide wax, polytetrafluoroethylene wax, amido wax and other waxes, and coconut oil fatty acids and soybean oil fatty acids of about C8 to C18. Examples include fatty acids in the range.

The pigment used in the active energy ray-curable offset ink composition of the present invention is not particularly limited, and either an untreated pigment or a treated pigment can be applied.

Specifically, known inorganic pigments and organic pigments can be used. Examples of the inorganic pigment include iron oxide, carbon black produced by a known method such as a contact method, a furnace method, and a thermal method. Examples of organic pigments include azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments, etc.) and polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, and dioxazines. Pigments, thioindigo pigments, isoindolinone pigments, quinofuralon pigments, etc.), dye chelate (for example, basic dye type chelates, acidic dye type chelates, etc.), nitro pigments, nitroso pigments, aniline black and the like can be used.
In particular, in black ink, the polar group of carbon black has a high affinity with a monomer having a high acid value. Therefore, the active energy ray-curable offset ink composition described in the present invention can be used.
It is particularly suitable for black ink whose pigment is carbon black.

Examples of the pigment used in the black ink include carbon black produced by a known method such as a furnace method, a thermal method, and a contact method. For example, Raven 14, Raven 450, Raven 860 Ultra, Raven 1035, etc. Raven 1040, Raven 1060 Ultra, Raven 1080 Ultra, Raven 1180, Raven 1255 (above, Colombian Chemical), Regal 400R, Legal 330R, Regal 660R, Mogle L (above, Cabot), MA7, MA8, MA11 (above) , Mitsubishi Chemical Co., Ltd.), etc., and these may be used alone or in combination of two or more as appropriate.

Specific examples of the pigment used in the yellow ink include C.I. I. Pigment Yellow 1, 2, 12, 13, 14, 16, 17, 73, 74, 75, 83, 93, 95, 97, 98, 109, 110, 114, 120, 128, 129, 138, 150, 151, 154, 155, 174, 180, 185 and the like can be mentioned.

Specific examples of pigments used in magenta ink include C.I. I. Pigment Red 5, 7, 12, 48 (Ca), 48 (Mn), 57 (Ca), 57: 1, 112, 122, 123, 146, 168, 176, 184, 185, 202, 209, 269, etc. C. I. Pigment Violet 19 and the like.

Specific examples of pigments used in cyan ink include C.I. I. Pigment Blue 1, 2, 3, 15, 15: 3, 15: 4, 16, 22, 60, 63, 66 and the like.

Further, in the active energy ray-curable offset ink composition of the present invention, inorganic fine particles may be used as the extender pigment. Inorganic fine particles include inorganic coloring pigments such as titanium oxide, graphite, and zinc flower; lime carbonate powder, precipitated calcium carbonate, plaster, ChinaClay, silica powder, diatomaceous earth, talc, kaolin, alumina white, barium sulfate, and stear. Inorganic pigments such as aluminum acid, magnesium carbonate, barite powder, abrasive powder; and other inorganic pigments, silicone, glass beads, and the like can be mentioned. By using these inorganic fine particles in the ink in the range of 0.1 to 20% by mass, it is possible to obtain effects such as adjusting the fluidity of the ink, preventing misting, and preventing penetration into a printing substrate such as paper. is there.

In the active energy ray-curable offset ink composition of the present invention, as other formulations of the above-mentioned components, dyes, organic solvents, antistatic agents, antifoaming agents, viscosity modifiers, light-resistant stabilizers, weather-resistant stabilizers, etc. Additives such as heat-resistant stabilizers, ultraviolet absorbers, antioxidants, leveling agents, and pigment dispersants can be used.

The printing substrate used in the active energy ray-curable offset ink composition of the present invention is not particularly limited, and for example, catalogs, posters, leaflets, CD jackets, direct mails, brochures, cosmetics and beverages, pharmaceuticals, toys, equipment, etc. High-quality paper, coated paper, art paper, imitation paper, thin paper, thick paper, etc., various synthetic papers, polyester resin, acrylic resin, vinyl chloride resin, vinylidene chloride resin, polyvinyl alcohol, polyethylene, etc. Films or sheets of polypropylene, polyacrylonitrile, ethylene vinyl acetate copolymer, ethylene vinyl alcohol copolymer, ethylene methacrylate copolymer, nylon, polylactic acid, polycarbonate, etc., cellophane, aluminum foil, and other conventional printing substrates Various base materials used can be mentioned.

The production of the active energy ray-curable offset ink composition described in the present invention is the same as that of the conventional active energy ray-curable offset ink composition purple, the coloring pigment, the polymerizable acrylate monomer, the binder resin, the photopolymerization initiator, and the like. It is produced by blending a sensitizer, other additives, etc., stirring and mixing with a mixer or the like, and kneading the meat with a disperser such as a three-roll mill or a bead mill.

Hereinafter, the present invention will be specifically described with reference to Examples.
The acid value of the resin is the acid value (mgKOH / g) measured by the following method.

Take 100 ml of a sample in an Erlenmeyer flask (300 ml), add 2-3 drops of a phenolphthalein solution (1 w / v%) prepared by 3 of JIS K 8006 as an indicator, and use a micro burette with an N / 10 alcoholic potassium hydroxide solution. The acid value A is obtained by the following formula, with the end point being when the very faint red of the solution does not disappear for 30 seconds or more after titration.
A = (5.61 × V) / (S × G)
Here, A is the acid value, S is the sample (ml), G is the specific density of the sample at the temperature at the time of measurement, and V is the amount (ml) of the N / 10 alcoholic potassium hydroxide solution used.

Production Example 1 [Synthesis of polyfunctional acrylate (A1) having an acid value of 1.0 to 10.0]
185 g (2.57 mol) of acrylic acid, 3.0 g (0.017 mol) of p-toluenesulfonic acid, 0.03 g (0.00024 mol) of monomethylhydroquinone and toluene per 100 g (0.39 mol) of dipentaerythritol. 240 g was charged into a flask, and the mixture was heated and stirred at 110 ° C. while blowing air, and the generated water was distilled off from the system. After distilling water for about 6 hours, the mixture was cooled to room temperature. The above reaction solution was washed once with water (100 g), 0.03 g of monomethylhydroquinone was added thereto, and toluene was distilled under reduced pressure at 80 ° C. and 10 mmHg to obtain DPHA (acid value 10 mgKOH / g).
By changing the number of washings with water to the following, DPHA having different acid values was prepared.
It was confirmed that the one without washing with water had an acid value of 15 mgKOH / g.

No washing with water: Acid value 15 mg KOH / g
Washing once: Acid value 10 mg KOH / g
Washing twice: Acid value 5 mgKOH / g
Washing 3 times: Acid value 3 mgKOH / g
Washing 4 times: Acid value 1.4 mgKOH / g
Washing 5 times: Acid value 1.2 mgKOH / g
Washing 6 times: Acid value 0.8 mgKOH / g
Washing 7 times: Acid value 0.4 mgKOH / g

Similarly, trimethylolpropane tetraacrylate (DTMPTA), ethylene oxide-modified trimethylolpropane triacrylate (EOTMPTA), propylene oxide-modified trimethylolpropane triacrylate (POTMPTA), and trimethylolpropane triacrylate (TMPTA) are also not washed with water. In addition to acrylates having an acid value of 10.0 mgKOH / g or more, acrylates having an acid value of 0.8 mgKOH / g, 1.2 mgKOH / g, 3.0 mgKOH / g, or 10.0 mgKOH / g can be obtained by changing the number of washings with water. Made.

Production Example 2 [Synthesis of Urethane Acrylate Resin (B1) Using Polyol]
In a four-necked flask equipped with a stirrer, gas introduction tube, condenser, and thermometer, as the first step, polymethylene polyphenyl polyisocyanate (“Millionate MR-400” manufactured by Nippon Polyurethane Industry Co., Ltd., dinuclear component 29) 59.4 parts by mass, 0.1 parts by mass of tertiary butyl hydroxytoluene, 0.02 parts by mass of methoxyhydroquinone, 0.02 parts by mass of zinc octylate were added to 75 parts by mass. The temperature was raised to ° C., and 37.3 parts by mass of 2-hydroxyethyl acrylate was added dropwise with stirring over 1 hour. After the dropping, the reaction is carried out at 75 ° C. for 3 hours, and then 3.3 parts by mass of glycerin is added as a second step, and the reaction is further carried out at 75 ° C., and the infrared absorption spectrum of ^{2250 cm -1 showing an isocyanate group disappears.} The reaction was carried out to obtain a urethane acrylate resin (A1). The obtained urethane acrylate resin (A1) had a weight average molecular weight (Mw) of 5438 and an acryloyl group concentration of 3.22 mmol / g.

[Making urethane acrylate varnish]
The urethane acrylate resin (B1) is sufficiently dissolved in 40% by mass of ethylene oxide (added by 3 mol on average) -modified trimethylolpropane triacrylate (MIRAMER M3130, manufactured by MIWON) so as to have a solid content of 60% by mass at 90 ° C. The mixture was stirred to prepare a urethane acrylate varnish.

[Making DAP varnish]
Diallyl phthalate resin (Daiso Dup A, manufactured by Daiso) Solid content 39% by mass and ethylene oxide (added by 3 mol on average) modified trimethylolpropane triacrylate (MIRAMER M3130, manufactured by MIWON) 61% by mass are sufficiently dissolved at 90 ° C. A DAP varnish was prepared by stirring.

[Manufacturing method of ink composition]
Various active energy ray-curable offset ink compositions were obtained by kneading the inks of Examples 1 to 18 and Comparative Examples 1 to 11 with a three-roll mill according to the compositions of Tables 1 to 4.
The numerical values in Tables 1 to 4 are mass%.

[Example 1]
For Example 1, 59% by mass of DPHA having an acid value of 15 mgKOH / g and 10% by mass of urethane acrylate varnish were added.
For all ink compositions, 20% by mass of Raben 1060 Ultra manufactured by Columbian Chemical Co., Ltd., which is carbon black as a coloring component, 4% by mass of magnesium carbonate TT (manufactured by Naikai Salt Industry Co., Ltd.) as a viscosity and fluidity modifier, and an auxiliary agent. As a polyethylene wax 1% by mass, as a photopolymerization initiator Irgacare907 (α-aminoalkylphenone-based initiator, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, manufactured by BASF Co., Ltd., Number average molecular weight 279.4,) 3% by mass, Tokyo Kasei Co., Ltd. CHAMARK DEABP (diethylaminobenzophenone) 2% by mass, polymerization inhibitor base 1 as a polymerization inhibitor (Wako Pure Chemical Industries, Ltd. Q1301 (N-nitrosophenylhydroxylamine) 1% by mass of (aluminum salt) was commonly added to 1% by mass of a liquid mixture in which 1% by mass of MIWON was dissolved in 95% by mass of MIRAMER M300 (trimethylol propantriacrylate) manufactured by MIWON.

[Examples 2 to 18 and Comparative Examples 1 to 11]
For Examples 2 to 18 and Comparative Examples 1 to 11, black ink was prepared in the same procedure as in Example 1 according to the formulation shown in Tables 1 to 4. In Example 10, 10% by mass of DAP varnish was used in combination.

[Manufacturing method of colored products]
The active energy ray-curable ink composition thus obtained was applied onto a rubber roll and a metal roll of the RI tester using a simple color developer (RI tester, manufactured by Hoei Seiko Co., Ltd.) and 0.10 ml of ink. On the surface of coated cardboard (UF coat manufactured by Oji Materia, 350 g / m ^{2 of} paper density), use a black density of 1.8 (measured with a SpectroEye densitometer manufactured by X-Rite) over an area of 200 cm ^2. The color was spread so that it was applied evenly, and a colored product was prepared. The RI tester is a testing machine that spreads ink on paper or film, and can adjust the amount of ink transfer and printing pressure.

[Curing method using UV lamp light source]
After the ink was applied, the color-developed material was irradiated with ultraviolet rays (UV), which are active energy rays, to cure the ink film. Using a water-cooled metal halide lamp (output 100 W / cm 1 lamp) and a UV irradiation device equipped with a belt conveyor (manufactured by Eye Graphics, cold mirror included), place the colored object on the conveyor and directly under the lamp (irradiation distance 11 cm). Was passed at a speed of 40 meters per minute to cure the ink film.

[Evaluation method 1: Ink fluidity]
The ink fluidity was measured by the spread meter method (parallel plate viscometer) according to JIS K5101, 5701, and the ink sandwiched between two horizontally placed parallel plates was the weight of the load plate (115). The characteristics of concentric spreading were observed over time, and the spread diameter of the ink after 60 seconds was measured as a viscometer value (DM [mm]). If the composition has a DM of less than 25 mm in this evaluation item, defects in printability such as pot-raising on the printing machine and poor transfer between ink rollers are likely to occur.
If the DM is 35 mm or more, it is considered good.

⊚: 40 mm or more ○: less than 35-40 mm Δ: less than 30-35 mm ×: less than 30 mm

[Evaluation method 2: Gloss of colored objects]
The gloss value of the obtained colored product was measured with a 60 ° gloss meter (manufactured by BYK Gardener GmbH) and evaluated in the following four stages. The higher the value, the better the gloss.
A gloss value of 43 or more is considered to be good.

⊚: Gloss value is 50 or more 〇: Gloss value is 43 or more and less than 50 Δ: Gloss value is 38 or more and less than 43 ×: Gloss value is less than 38

[Evaluation method 3: Printability]
The active energy ray-curable inks of Examples 1 to 18 and Comparative Examples 1 to 11 produced were evaluated for offset printing suitability and printed matter quality. 9000 sheets per hour using a Munroland offset printing machine (Roland R700 printing machine, 40-inch wide machine) equipped with an eye graphics water-cooled metal halide lamp (output 160 W / cm, using 3 lights) as an ultraviolet irradiation device. Offset printing was performed at the printing speed of. OK Top Coat Plus (57.5 kg, A size) manufactured by Oji Paper Co., Ltd. was used as the printing paper. As the dampening water supplied to the plate surface, an aqueous solution obtained by mixing 98% by weight of tap water and 2% by weight of an etchant (FST-700, manufactured by DIC) was used.

As an evaluation method of offset ink printability, first set the water supply dial of the printing machine to 40 (standard water volume), and the printed matter density is standard process ink density 1.8 (measured by X-Rite's SpectroEye densitometer). The ink supply key was operated so that the ink supply key was fixed when the density became stable. After that, under the condition that the ink supply key was fixed, the water supply dial was changed from 40 to 55, and 300 sheets were printed under the condition that the water supply amount was increased, and the ink density of the printed matter after 300 sheets was measured. Even when the amount of water supplied is increased, the smaller the decrease in the density of the printed matter, the better the emulsification suitability and the better the printability. The printability of the active energy ray-curable ink was evaluated according to the following criteria.

⊚: The black density of the printed matter is 1.7 or more, and the offset printing suitability is the best.
◯: The black density of the printed matter is 1.6 or more and less than 1.7, and the offset printing suitability is good.
Δ: The black density of the printed matter is 1.5 or more and less than 1.6, and the offset printing suitability is at a medium usable level.
X: The black density of the printed matter is less than 1.5, and the offset printing suitability is poor.

In the active energy ray-curable offset ink composition described in the examples, the printability judged from the fluidity of the ink, the gloss of the printed matter, and the density stability were all excellent.

The active energy ray offset ink of the present invention and printed matter printed using it are used for paper container packaging applications such as foods, beverages, sanitary products, cosmetics, toys, equipment, pharmaceuticals, and books, leaflets, posters, catalogs, cards, and direct products. It can be widely used for commercial printing such as mails, pamphlets, CD jackets, and seal labels.

Claims (9)

An active energy ray-curable offset characterized by containing an active energy ray-curable monomer (A), a resin (B), and a coloring pigment (C) having an acid value of 1.0 to 3.0 mgKOH / g. Ink composition.
The active energy ray-curable offset ink composition according to claim 1, wherein the active energy ray-curable monomer (A) is a polyfunctional acrylate (A1).
The active energy ray-curable monomer (A) is a mixture of dipentaerythritol penta (meth) acrylate and dipentaerythritol hexa (meth) acrylate (DPHA), ditrimethylolpropane tetraacrylate (DTMPTA), and ethylene oxide-modified trimethylolpropane tri. The active energy ray-curable offset according to claim 1 or 2, which is one or more selected from the group consisting of acrylate (EOTMPTA), propylene oxide-modified trimethylolpropane triacrylate (POTMPTA), and trimethylolpropane triacrylate (TMPTA). Ink composition.
The active energy ray-curable offset ink composition according to any one of claims 1 to 3, wherein the resin (B) is a urethane (meth) acrylate resin (B1) and / or a diallyl phthalate resin (B2).
The active energy ray-curable offset ink composition according to claim 4, wherein the urethane (meth) acrylate resin (B1) contains an aromatic polyisocyanate (a) and a hydroxyl group-containing mono (meth) acrylate (b) as essential raw materials. ..
The active energy ray-curable offset ink composition according to claim 4 or 5, wherein the urethane (meth) acrylate resin (B1) further contains a polyol (c) as an essential raw material. The active energy ray-curable offset ink composition according to any one of claims 4 to 6, wherein the urethane (meth) acrylate resin (B1) has a weight average molecular weight in the range of 3,000 to 40,000. Stuff.
The active energy ray-curable offset ink composition according to any one of claims 1 to 7, wherein the coloring pigment (C) is carbon black.
A printed matter obtained by printing using the active energy ray-curable offset ink composition according to any one of claims 1 to 8.