JP6931989B2 - Active energy ray-curable offset ink composition - 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 is excellent in printability, it is difficult to obtain fluidity (for example, Patent Document 1). Further, an ultraviolet curable offset ink using a specific urethane (meth) acrylate resin obtained by further reacting a reaction product of an aromatic polyisocyanate with a hydroxyl group-containing mono (meth) acrylate with a polyfunctional polyol (c). As described above, although the printability is excellent, the fluidity is difficult to obtain (for example, Patent Document 2). Since the fluidity of the ink affects the amount of ink discharged, it also affects the gloss of the printed matter.
Especially for yellow ink, which is difficult to maintain fluidity, it is desired to improve the pot-lifting property more than other colors.

JP 2016-079211 WO2016 / 063625

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

As a result of intensive research to solve the above problems, the present inventors have obtained urethane (meth) acrylate resin (A), diallyl phthalate resin (B), (meth) acrylic monomer (C) and pigments other than the above. The active energy ray-curable offset ink composition characterized by containing the ink has excellent fluidity of the ink, and the obtained printed matter has been found to be a printing ink capable of obtaining high gloss, and the present invention has been completed. rice field.

That is, the present invention is characterized in that the urethane (meth) acrylate resin (A), the diallyl phthalate resin (B), the (meth) acrylic monomer (C) other than the above, and the pigment are essential components. Regarding sex compositions.

Further, in the present invention, the urethane (meth) acrylate resin (A) 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 (A) 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 (A) 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 a yellow pigment.

The present invention further relates to a printed matter obtained by printing 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 in which the fluidity of the ink is excellent and the obtained printed matter has high gloss.

The present invention exhibits the desired effect of the present invention by containing a urethane (meth) acrylate resin (A), a diallyl phthalate resin (B), a (meth) acrylic monomer (C) other than the above, and a pigment. be.

The urethane (meth) acrylate resin (A) used in the present invention is preferably one obtained by reacting a polyfunctional aromatic isocyanate (a) with a hydroxyl group-containing mono (meth) acrylate (b). Among them, the ratio of the latter hydroxyl group (b') to the isocyanate group (a') of the former polyfunctional aromatic isocyanate (a) [(b') / (a')] is 0.99 to 0.40. It is more preferable that the reaction is carried out at a certain ratio.

Further, as the urethane (meth) acrylate resin (A) 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 (A).

Examples of the polyfunctional aromatic isocyanate (a) include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, diphenylmethane-4,4-diisocyanate, and 1,5. -Diisocyanate compounds such as naphthalenediocyanate; 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. Can be mentioned. These polyfunctional aromatic isocyanates may be used alone or in combination of two or more. By having an aromatic structure in the chemical structure of the raw material polyfunctional isocyanate compound, excellent curability can be exhibited when a printing ink using the finally obtained urethane (meth) acrylate resin is produced.

Among these, a polyfunctional polyisocyanate compound containing a component having three or more isocyanate groups per molecule (a trifunctional or higher functional component) is particularly preferable because a UV curable ink having more excellent curability can be designed. Specifically, those containing trifunctional or higher functional components in a proportion of 30% by mass or more are preferable. 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 by an E-type viscometer (25 ° C.).

Examples of the hydroxyl group-containing mono (meth) acrylate (b) to be reacted with the polyfunctional aromatic isocyanate (a) include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl acrylate, and hydroxyethyl. Examples thereof include hydroxyl group-containing (meth) acrylates such as vinyl ether; ethylene oxide adducts of the hydroxyl group-containing (meth) acrylate, propylene oxide adducts of the hydroxyl group-containing (meth) acrylate, tetramethylene glycol adducts, and lactone adducts. 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 because they have excellent curability of the composition.

As a method for reacting the polyfunctional aromatic isocyanate (a) with the hydroxyl group-containing mono (meth) acrylate (b), the polyfunctional aromatic isocyanate (a) and, if necessary, a known and commonly used urethane Examples thereof include a method in which a conversion catalyst is added and heated to 20 to 120 ° C., and a predetermined amount of the hydroxyl group-containing mono (meth) acrylate (b) is continuously or intermittently added 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 (A) having a higher functional group concentration. Here, it is preferable that the polyol (c) is 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 urethane (meth) acrylate resin (A) finally obtained is obtained. The functional group concentration of the is reduced, and the effect of improving the curability is reduced.

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), the trifunctional polyols 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 include 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 (A) 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 misting property and curability.

Here, the urethane (meth) acrylate resin (A) 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.

If the reaction between the aromatic polyisocyanate (a) and the hydroxyl group-containing mono (meth) acrylate (b) is the first step, the reaction product obtained in the first step in the second step may contain the polyol (c). , And the reaction is carried out until the infrared absorption spectrum of ^{2250 cm-1} showing an isocyanate group disappears.

In the urethane (meth) acrylate resin (A) thus obtained, the reaction product of the aromatic polyisocyanate (a) and the hydroxyl group-containing mono (meth) acrylate (b) is present via the polyol (c). It is a urethane (meth) acrylate resin having a knotted structure and a high concentration of (meth) acryloyl groups. Specifically, the urethane (meth) acrylate resin (A) is characterized in that the (meth) acryloyl group concentration is in the range of 1.5 to 4.0 mmol / g. When the (meth) acryloyl group concentration is less than 1.5 mmol / g, excellent curability cannot be obtained. On the other hand, when the (meth) acryloyl group concentration exceeds 4.0 mmol / g, the fluidity of the urethane (meth) acrylate resin (A) becomes too high, the misting performance of the printing ink deteriorates, and the hydroxyl group-containing mono. The risk that the (meth) acrylate (b) remains in the printing ink also increases.

The urethane (meth) acrylate resin (A) thus obtained must have a weight average molecular weight (Mw) in the range of 3,000 to 40,000 for 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 (B) 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 is particularly useful for imparting excellent emulsion resistance and long-run printability.
Specific examples of the diallyl phthalate resin 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 is preferably 5 to 25% by mass, more preferably 10 to 20% by mass.
If the content of the diallyl phthalate resin 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 exceeds 25% by mass, the fluidity of the ink is significantly impaired, and sufficient printability may not be imparted.

In the active energy ray-curable offset ink composition of the present invention, the effect of the present invention can be obtained by using the urethane (meth) acrylate resin (A) and the diallyl phthalate resin (B) in combination. The mass ratio of the urethane (meth) acrylate resin (A): diallyl phthalate resin (B) to be used is in the range of (A): (B) = 5:95 to 95: 5.

Known as the (meth) acrylic monomer (C) other than the urethane (meth) acrylate resin (A) and the diallyl phthalate resin (B) used in the active energy ray-curable offset ink composition of the present invention. It can be arbitrarily selected and used from.
In the present invention, "(meth) acrylic" is a general term for acrylic and methacryl.

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

As another example of the (meth) acrylic monomer, polyethylene glycol having an ethylene glycol unit in the molecule (n is 3 or more and about 14 or less) di (meth) acrylate, trimethylolpropane EO modified (n is 3 or more). (Approximately 14 or less) Tri (meth) acrylate, phenolEO modified (n is 3 or more and 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 trimethyl (meth) acrylate, monohydroxyethyl phthalate (meth) acrylate and the like can be mentioned.

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

In the case of applications in which curing shrinkage is an obstacle, for example, isobornyl (meth) acrylate, norbornyl (meth) acrylate, dicyclopentenoxyethyl (meth) acrylate, dicyclopentenoxypropyl (meth) acrylate, etc. Acrylate or methacrylic acid ester of diethylene glycol dicyclopentenyl monoether, acrylic acid ester or methacrylic acid ester of polyoxyethylene or polypropylene glycol dicyclopentenyl monoether, dicyclopentenyl cinnamate, dicyclopentenoxyethyl cinnamate, etc. , Dicyclopentenoxyethyl monofumalate or difumalate, etc. 3,9-bis (1,1-bismethyl-2-oxyethyl) -spiro [5,5] undecane, 3,9-bis (1,1-bismethyl) -2-oxyethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane, 3,9-bis (2-oxyethyl) -spiro [5,5] undecane, 3,9-bis (2) -Oxyethyl) -2,4,8,10-Tetraoxaspiro [5,5] Monomer such as undecane, diacrylate or mono-, dimethacrylate, or ethylene oxide or propylene oxide addition polymer of these spiroglycols. Mono-, diacrylate, or mono-, dimethacrylate, or methyl ether of the mono (meth) acrylate, 1-azabicyclo [2,2,2] -3-octenyl (meth) acrylate, bicyclo [2,2] 1] -5-Hepten-2,3-dicarboxymonoallyl ester, dicyclopentadienyl (meth) acrylate, dicyclopentadienyloxyethyl (meth) acrylate, dihydrodicyclopentadienyl (meth) acrylate (Meta) acrylic monomers such as, etc. can be used.

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 of a 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, trimethylolpropane tri (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.

The active energy ray-curable offset ink composition of the present invention can be formed into a cured film by irradiating the substrate with active energy rays after printing. Examples of this active energy ray include ionizing radiation such as ultraviolet rays, electron beams, α rays, β rays, and γ rays. Among these, ultraviolet rays (UV) are particularly preferable from the viewpoint of curability and convenience.

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 ultrahigh 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, benzyl dimethyl ketal, and 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-propane-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-) Oxime compounds such as methylbenzoyl) -9H-carbazole-3-yl]-, 1- (O-acetyloxime), 3,6-bis (2-methyl-2-morpholinopropanonyl) -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 Aminoalkylphenones such as -1-one, 2-methyl-2-morpholino ((4-methylthio) phenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone System compounds; bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl -Acylphosphine oxide-based compounds such as pentylphosphine oxide; 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 weight as the total amount used with respect to 100% by weight 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 weight or more, good curability can be obtained, and when it is 20% by weight or less, the unreacted polymerization initiator remains in the cured product. It is possible to avoid problems such as migration, solvent resistance, weather resistance and other deterioration of physical properties 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 weight with respect to 100% by weight 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 weight of the non-volatile component in the active energy ray-curable ink composition of the present invention, because the effect of improving the curability is good. It is preferably in the range of about 20% by weight.

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.

Among them, powder type or particle type polyolefin wax typified by polyethylene wax and oxide polyethylene wax are preferable because good ink fluidity and curability can be obtained, and the melting point of the polyolefin wax is in the range of 90 to 130 ° C. A polyolefin wax having an average particle size D50 in the range of 1 to 10 micrometer is more preferable. When the average particle size D50 is less than 1 micrometer, it is difficult to improve the curability, and when it exceeds 10 micrometers, the ink transfer property on the printing machine is remarkably lowered and the offset printing suitability is impaired, which is not preferable. Further, it is preferable that the total amount of wax used is in the range of 0.1 to 5% by weight with respect to 100% by weight of the non-volatile component in the active energy ray-curable composition of the present invention.

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, quinoflorone 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.

Examples of the pigments by color include carbon black produced by known methods such as a furnace method, a thermal method, and a contact method as pigments used in black ink. For example, Raven 14 and Raven. 450, Raven 860 Ultra, Raven 1035, Raven 1040, Raven 1060 Ultra, Raven 1080 Ultra, Raven 1180, Raven 1255 (above, made by Colombian Chemical), Legal 400R, Legal 330R, Legal 660R, Mogle L (above, manufactured by Cabot) , MA7, MA8, MA11 (all manufactured by Mitsubishi Chemical Corporation) and the like, 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.
In particular, yellow ink, which is difficult to maintain fluidity, tends to have a poor pot-lifting property as compared with other colors, and the active energy ray-curable offset ink composition described in the present invention is particularly suitable for yellow ink.

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.

Specific examples of pigments used in white ink include alkali earth metal sulfates, carbonates, fine powder silicic acid, synthetic silicates, and other silicas, calcium silicate, alumina, and alumina hydrate. Examples include titanium oxide, zinc oxide, talc, and clay. Further, the inorganic white pigment may be surface-treated by various surface treatment methods.

In addition, inorganic fine particles may be used as the extender pigment in the active energy ray-curable offset ink composition of the present invention. Inorganic fine particles include inorganic coloring pigments such as titanium oxide, graphite, and zinc flower; lime carbonate powder, precipitated calcium carbonate, gypsum, ChinaClay, silica powder, diatomaceous earth, talc, kaolin, alumina white, barium sulfate, stearer. 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 weight, 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. be.

In the active energy curable offset ink composition of the present invention, various known and public binder resins can be further used. The binder resin described here refers to all resins having appropriate pigment affinity and dispersibility and having the rheological properties required for printing inks. For example, as the non-reactive resin, an epoxy resin or a polyurethane resin is used. , 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 copolymer, etc. These binder resin compounds may be used alone or in combination of any one or more of them.

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 urethane oligomer (varnish), and the binder resin. , Photopolymerization initiator, sensitizer, other additives, etc. are mixed, stirred and mixed with a mixer or the like, and the meat is kneaded using a disperser such as a three-roll mill or a bead mill.

Hereinafter, the present invention will be specifically described with reference to Examples.

Production Example 1 [Synthesis of urethane acrylate resin (A1) 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.

Production Example 2 [Synthesis of urethane acrylate resin (A2) without 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) 54.6 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 45.4 parts by mass of 2-hydroxyethyl acrylate was added dropwise with stirring over 1 hour. After the dropping, the reaction was carried out at 75 ° C. ^{until the infrared absorption spectrum of 2250 cm -1} showing an isocyanate group disappeared to obtain a urethane acrylate resin (A2). The amount of residual 2-hydroxyethyl acrylate in the urethane acrylate resin (A2) was 5350 ppm. The weight average molecular weight (Mw) was 1504, and the acryloyl group concentration was 3.91 mmol / g.

[Making Urethane Acrylate Varnish I]
The urethane acrylate resin (A1) 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 urethane clear varnish I.

[Preparation of Urethane Acrylate Varnish II]
The urethane acrylate resin (A2) 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 that the solid content is 65% by mass at 90 ° C. The mixture was stirred to prepare urethane clear varnish I.

[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 6 and Comparative Examples 1 to 3 with a three-roll mill according to the composition shown in Table 1.
The numerical values in Table 1 are mass%.
In Example 1, 19.9% by mass of urethane acrylate varnish I and 30.7% by mass of DAP varnish were added so that the solid content ratios of each were equal, and further, as the (meth) acrylic monomer (C), 17% by mass of ethylene oxide (added by an average of 3 mol) -modified trimethylolpropane triacrylate (MIRAMER M3130, manufactured by MIWON) was added.
For all ink compositions, SYMULER Fast Yellow 8GF manufactured by DIC Corporation, which is a yellow indigo pigment as a coloring component, 14% by mass of (Polyment No. 17 yellow), 6% by mass of magnesium carbonate as a viscosity and fluidity modifier, 1% by mass of paraffin wax as an auxiliary agent, 6% by mass of Irgacure369 (2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butane-1-one) manufactured by BASF as a photopolymerization initiator, and manufactured by Tokyo Kasei Co., Ltd. CHAMARK DEABP (diethylaminobenzophenone) 4% by mass, polymerization inhibitor base 1 as a polymerization inhibitor (Q1301 (N-nitrosophenyl hydroxylamine aluminum salt) manufactured by Wako Pure Chemical Industries, Ltd.) 5% by mass, MIRAMER M300 (trimethylol propane) manufactured by MIWON Triacrylate) 1% by mass of a liquid mixture dissolved in 95% by mass was commonly added.
Further, 1.31 ml of each of the prepared ink compositions was applied to an incometer manufactured by Toyo Seiki Co., Ltd., and the ink composition was rotated at a roller temperature of 32 ° C. and a rotation speed of 400 rpm. ) The value was read, and it was confirmed that the tack value (TV) value was the standard 10 in all cases.

For Examples 2 and 3, inks were prepared in the same procedure as in Example 1 except that the solid content ratios of the urethane acrylate varnish I and the DAP varnish were changed to the ratios shown in Table 1. For Examples 4 to 6, ink was prepared in the same procedure as in Example 1 except that the solid content ratios of the urethane acrylate varnish II and the DAP varnish were changed to the ratios shown in Table 1. .. For Comparative Examples 1 to 3, inks were prepared by using urethane acrylate varnishes I, II, and DAP varnishes independently.

[Manufacturing method of colored products]
The active energy ray-curable ink composition thus obtained was subjected to a simple color developer (RI tester, manufactured by Hoei Seiko Co., Ltd.) on a rubber roll and a metal roll of the RI tester using 0.10 ml of ink. On the surface of coated cardboard (UF coat manufactured by Oji Materia, 350 g / m ^{2 of} paper density) with a yellow density of 1.4 (measured with a SpectroEye densitometer manufactured by X-Rite) over an area of 200 cm ^2. The color was spread so as to be 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 100 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]). When the composition has a DM of less than 38 mm in this evaluation item, defects in printability such as jar breakage on the printing machine and transfer defects between ink rollers are likely to occur.

[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 three stages. The higher the value, the better the gloss.

〇: Gloss value is 30 or more Δ: Gloss value is 25 or more and less than 30 ×: Gloss value is less than 25

In the active energy ray-curable offset ink composition described in the examples, by using the urethane (meth) acrylate resin (A) and the diallyl phthalate resin (B) in combination, the fluidity of the ink is excellent, and the obtained printed matter is obtained. High gloss is obtained. Further, as shown in Examples 1 to 3, when the (meth) acrylate resin (A) uses the polyol (c) as a raw material, the effect is even better.
In the comparative example in which the urethane acrylate varnishes I, II, and DAP varnish were used alone, both the fluidity of the ink and the gloss of the printed matter were inferior.

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, etc., and books, leaflets, posters, catalogs, cards, directs, etc. It can be widely used for commercial printing such as mails, pamphlets, CD jackets, and sticker labels.

Claims (4)

An active energy ray-curable offset yellow ink composition containing a urethane (meth) acrylate resin (A), a diallyl phthalate resin (B), a (meth) acrylic monomer (C) other than the above, and a yellow pigment.
However, the urethane (meth) acrylate resin (A) has a weight average molecular weight in the range of 3,000 to 40,000, and the content of the diallyl phthalate resin (B) is 5 to 5 of the total amount of the ink composition. It is 25% by mass, and the mass ratio of urethane (meth) acrylate resin (A): diallyl phthalate resin (B) is 1: 3 to 3: 1.
The active energy ray-curable offset yellow ink composition according to claim 1, wherein the urethane (meth) acrylate resin (A) uses an aromatic polyisocyanate (a) and a hydroxyl group-containing mono (meth) acrylate (b) as essential raw materials. thing.
The active energy ray-curable offset yellow ink composition according to claim 2, wherein the urethane (meth) acrylate resin (A) further uses a polyol (c) as an essential raw material.
A printed matter obtained by printing using the active energy ray-curable offset yellow ink composition according to any one of claims 1 to 3.