JP6841363B2 - Active energy ray-curable lithographic printing ink and printed matter - Google Patents

Description

The present invention relates to an active energy ray-curable lithographic printing ink that can be cured by irradiation with active energy rays such as ultraviolet rays and electron beams. In particular, the present invention relates to a lithographic printing ink using a resin obtained by copolymerizing an ethylenically unsaturated monomer having two or more unsaturated double bonds.

The lithographic printing ink is an ink having a relatively high viscosity of 5 to 100 Pa · s. In the lithographic printing machine mechanism, ink is supplied from the ink fountain of the printing machine to the image area of the plate surface via multiple rollers, and in lithographic printing using dampening water, dampening water is supplied to the non-image area. In lithographic printing without dampening water, the non-image area is made of a silicon layer, which repels the ink and forms an image on the paper.

In particular, in lithographic printing using dampening water, the emulsification balance between the ink and the dampening water is important, and the ink is also required to have emulsification resistance and high-speed printing suitability. If the amount of emulsification of the ink is too high, the ink will easily adhere to the non-image areas and stains will occur, and if the amount of emulsification is small, dampening water will be discharged to the ink surface during printing with a small number of patterns. Ink transfer and ink emulsification on paper deteriorate, making stable printing difficult.

Further, in recent years, there has been an increasing demand for labor saving, labor saving, automation, and speeding up at the time of printing, and in particular, the printing speed is getting faster and faster. There is a demand for printing inks that can stably obtain high-quality printed matter for a long time without trouble under various printing conditions, and ink makers have made various improvements.

The active energy ray-curable ink contains an unsaturated compound having active energy ray curability such as an acrylic ester compound as a constituent component, and is instantly cured by irradiation with active energy rays, and three-dimensional cross-linking of the unsaturated compound. To form a tough film. Since it cures instantly, post-processing can be performed immediately after printing, so active energy ray curing is used in packaging package printing and foam printing in the commercial field, where a strong film is required to improve productivity and protect the design. Mold ink is preferably used.

Generally, an active energy ray-curable lithographic offset printing ink is composed of a binder resin, an active energy ray-curable compound such as an acrylic ester compound, a pigment, a radical polymerization initiator, and various additives.

As the active energy ray-curable binder resin, unsaturated polyester resin, polyester acrylate resin, epoxy acrylate resin, urethane acrylate resin and the like have been studied. For example, Patent Document 1 discloses a resin obtained by modifying a saturated polyester with an isocyanate group-containing urethane acrylate. Patent Document 2 and Patent Document 3 disclose an acrylic resin containing styrenes as a copolymerization component. However, since these resins have a highly linear structure, it is difficult to obtain sufficient ink viscoelasticity, and they tend to impair printability such as emulsification suitability, misting property, and stain resistance.

Japanese Unexamined Patent Publication No. 2001-348516 Japanese Unexamined Patent Publication No. 2009-263622 Japanese Unexamined Patent Publication No. 2011-26522

An object of the present invention is to provide an active energy ray-curable lithographic offset printing ink having excellent emulsification suitability and a printed matter thereof.

An active energy ray-curable flat plate having excellent printability by containing a resin obtained by copolymerizing an ethylenically unsaturated monomer having two or more unsaturated double bonds and an ethylenically unsaturated monomer. They have found that an offset printing ink can be obtained, and have completed the present invention.

That is, the present invention contains 0.5 to 15 % by weight of the ethylenically unsaturated monomer (a1) having two or more unsaturated double bonds (except when the number is four or more ), and the like. It is characterized by containing a resin (A) obtained by copolymerizing an ethylenically unsaturated monomer containing 85 to 99.5% by weight of an ethylenically unsaturated monomer and an active energy ray-curable compound (B). a radiation-curable lithographic printing ink,
The other ethylenically unsaturated monomer contains an ethylenically unsaturated monomer (a2) having an aromatic ring.
The weight average absolute molecular weight of the resin (A) is 10,000 to 4,000,000.
The present invention relates to an active energy ray-curable lithographic printing ink in which the ratio of the weight average absolute molecular weight to the weight average relative molecular weight is 2 to 20.

The present invention also relates to the active energy ray-curable lithographic printing ink further containing a pigment (C).

The present invention also relates to the active energy ray-curable lithographic printing ink further containing a photopolymerization initiator (D).

The present invention also relates to a printed matter obtained by printing the active energy ray-curable lithographic printing ink on a substrate and curing the printed matter by the active energy ray.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an active energy ray-curable lithographic offset printing ink having excellent emulsification suitability and also having excellent dispersibility and fluidity, and a printed matter.

Hereinafter, the present invention will be described in detail.
In addition, in this application, when it is described as "(meth) acryloyl", "(meth) acrylic", "(meth) acrylic acid", "(meth) acrylate", or "(meth) acrylamide", it is particularly described. Unless otherwise noted, "acryloyl and / or methacrylic acid", "acrylic and / or methacrylic acid", "acrylic acid and / or methacrylic acid", "acrylate and / or methacrylate", or "acrylamide and / or methacrylic acid", respectively. It shall be represented.

Each component of the active energy ray-curable lithographic printing ink of the present invention will be described. The active energy ray-curable lithographic printing ink used in the present invention contains a resin (A) and an active energy ray-curable compound (B), and if necessary, a pigment (C) and a photopolymerization initiator (D). Further contained.
The active energy ray-curable flat plate printing ink of the present invention includes color printing inks such as yellow, red, indigo, and black, and transparent overprint varnish (commonly known as OP) that is printed by a printing machine after single-color or multicolor printing. Ink such as varnish) is included.
As an example of the composition of active energy ray-curable lithographic printing ink,
Resin (A) 10-40% by weight
Active energy ray-curable compound (B) 30 to 75% by weight
Pigment (C) 0-40% by weight
Photopolymerization initiator (D) 0 to 15% by weight
Other ingredients 1 to 15% by weight
Etc. are mentioned as preferable compositions.
<Resin (A)>
The resin (A) of the present invention is obtained by copolymerizing an ethylenically unsaturated monomer (a1) having two or more unsaturated double bonds with another ethylenically unsaturated monomer. An acrylic resin obtained by copolymerizing an ethylenically unsaturated monomer having two or more (meth) acryloyl groups with another ethylenically unsaturated monomer is preferable. The blending amount of the ethylenically unsaturated monomer (a1) having two or more unsaturated double bonds is 0.5 to 25% by weight based on 100% by weight of the total of the ethylenically unsaturated monomers, and is preferable. It is 0.5 to 15% by weight, more preferably 1 to 10% by weight. If the blending amount is less than 0.5% by weight, physical properties such as emulsification suitability of the ink deteriorate, which is not preferable. On the other hand, if it is more than 25% by weight, the solubility in the active energy ray-curable compound (B) tends to be inferior, which is not preferable.

The ethylenically unsaturated monomer (a1) having two or more unsaturated double bonds is not particularly limited as long as it can introduce a branched structure (crosslinked structure) into the molecule.

Examples of the bifunctional ethylenically unsaturated monomer include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and 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) ) Alkylene glycol di (meth) acrylates such as acrylates, and alkylene oxide adduct di (meth) acrylates of alkylene glycols,
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 ( Meta) 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-propanedioldi (meth) acrylate, 2,2,4-trimethyl -1,3-Pentanediol di (meth) acrylate, dimethylol octanedi (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, Alkanediol (meth) acrylate such as 5-pentanediol di (meth) acrylate, alkylene oxide adduct di (meth) acrylate of alkanediol,
In addition, hydroxypivalyl hydroxypivalate di (meth) acrylate (commonly known as manda), hydroxypivalyl hydroxypivalate dicaprolactonate di (meth) acrylate, tricyclodecanedimethylol di (meth) acrylate, tricyclodecanedimethylol. 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, water Additive bisphenol A tetraethylene oxide adduct di (meth) acrylate, water-added bisphenol F tetraethylene oxide adduct di (meth) acrylate, water-added bisphenol A di (meth) acrylate, water-added bisphenol F di (meth) acrylate, bisphenol Examples thereof include A tetraethylene oxide adduct dicaprolactonate di (meth) acrylate and bisphenol F tetraethylene oxide adduct dicaprolactonate di (meth) acrylate.

Examples of the trifunctional ethylenically unsaturated monomer include glycerin tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane tricaprolactonate tri (meth) acrylate, and trimethylolethanetri (meth) acrylate. , Trimethylolhexanetri (meth) acrylate, trimethyloloctanetri (meth) acrylate, pentaerythritol tri (meth) acrylate, and alkylene oxide adducts thereof and the like are exemplified.

Examples of the tetrafunctional or higher functional ethylenically unsaturated monomer include pentaerythritol tetra (meth) acrylate, pentaerythritol tetracaprolactonate tetra (meth) acrylate, diglycerin tetra (meth) acrylate, and ditrimethylol propanetetra (meth). Acrylate, Ditrimethylol Propanetetraca Prolactonate Tetra (Meta) Acrylate, Ditrimethylol Etantetra (Meta) Acrylate, Ditrimethylol Butane Tetra (Meta) Acrylate, Ditrimethylol Hexentetra (Meta) Acrylate, Ditrimethylol Octanetetra (Meta) Acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tripentaerythritol hexa (meth) acrylate, tripentaerythritol hepta (meth) acrylate, tripentaerythritol octa (meth) acrylate, tripentaerythritol Examples thereof include polyalkylene oxide hepta (meth) acrylates and alkylene oxide adducts thereof.
Examples of the alkylene oxide adduct include 1 to 10 molar adducts such as ethylene oxide, propylene oxide, butylene oxide, pentylene oxide and hexylene oxide.

These monomers can be used alone or in combination of two or more. The ethylenically unsaturated monomer (a1) having two or more unsaturated double bonds is preferably hydrophobic, for example, 1,9-nonanediol diacrylate, trimethylolpropane triacrylate, trimethylolpropane. Examples thereof include propanetetraacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate. When it is hydrophobic, it has an excellent tack reducing effect.

The number of unsaturated double bonds of the ethylenically unsaturated monomer (a1) having two or more unsaturated double bonds is preferably 2 to 8, and more preferably 4 to 7 within the above range. It is effective in reducing the tack of ink.

Other ethylenically unsaturated monomers include, for example,
Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2- Alkyl (meth) acrylates such as ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, behenyl acrylate, trimethylcyclohexyl (meth) acrylate, and isobornyl (meth) acrylate;
Aromatic (meth) acrylates such as phenyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, and phenoxydiethylene glycol (meth) acrylate;
Heterocyclic (meth) acrylates such as tetrahydrofurfreel (meth) acrylate and oxetane (meth) acrylate;
Alkoxypolyalkylene glycol (meth) acrylates such as methoxypolypropylene glycol (meth) acrylate and ethoxypolyethylene glycol (meth) acrylate;
N-substituted (meth) acrylamides such as (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, diacetone (meth) acrylamide, and acryloyl morpholine. ) Acrylamides;
Amino group-containing (meth) acrylates such as N, N-dimethylaminoethyl (meth) acrylate and N, N-diethylaminoethyl (meth) acrylate;
Examples thereof include nitriles such as (meta) acrylonitrile.

Further, as a monomer that can be used in combination with the above acrylic monomer,
Styrene and styrenes such as α-methylstyrene;
Vinyl ethers such as ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, and isobutyl vinyl ether;
Examples thereof include vinyl acetate and fatty acid vinyls such as vinyl propionate.

Further, a carboxyl group-containing ethylenically unsaturated monomer can also be used in combination. As the carboxyl group-containing ethylenically unsaturated monomer, one or more can be selected from acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid and the like.
These monomers can be used alone or in combination of two or more.

As the other ethylenically unsaturated monomer, it is preferable to use an ethylenically unsaturated monomer (a2) having an aromatic ring, for example, phenyl (meth) acrylate, benzyl (meth) acrylate, and phenoxyethyl (meth). ) Aromatic (meth) acrylates such as acrylate and phenoxydiethylene glycol (meth) acrylate, and styrenes such as styrene and α-methylstyrene. Aromatic (meth) acrylate is preferable, and benzyl (meth) acrylate is more preferable. The blending amount of the ethylenically unsaturated monomer (a2) having an aromatic ring is 75 to 99.5% by weight, preferably 85 to 99.5% by weight, based on 100% by weight of the total ethylenically unsaturated monomer. %, More preferably 90-99.5% by weight. Within the above range, the dispersion and fluidity of the ink are improved, and a glossy printed coating film can be obtained.

The resin (A) is 0 with respect to a total of 100 parts by weight of the ethylenically unsaturated monomer (a1) having two or more unsaturated double bonds as described above and the other ethylenically unsaturated monomers. It can be synthesized by a method such as bulk polymerization, solution polymerization, emulsion polymerization, or suspension polymerization using a polymerization initiator of .001 to 20 parts by weight, and is preferably a method by solution polymerization.

As the polymerization initiator, an azo compound and an organic peroxide can be used. Examples of azo compounds include 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane1-carbonitrile), and 2 , 2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2'-azobis (2-methylpropionate) , 4,4'-azobis (4-cyanovaleric acid), 2,2'-azobis (2-hydroxymethylpropionitrile), and 2,2'-azobis [2- (2-imidazolin-2-yl) ) Propane] and the like. Examples of organic peroxides are benzoyl peroxide, t-butyl (2-ethylhexanoyl) peroxide, t-butylperbenzoate, cumenehydroperoxide, diisopropylperoxydicarbonate, di-n-propylperoxy. Dicarbonate, di (2-ethoxyethyl) peroxydicarbonate, t-butylperoxyneodecanoate, t-butylperoxyvivarate, (3,5,5-trimethylhexanoyl) peroxide, dipropionyl peroxide , And diacetyl peroxide and the like. These polymerization initiators can be used alone or in combination of two or more.

In addition, a chain transfer agent can also be used in combination. Examples of the chain transfer agent include 1-mercapto-1,1-methanediol, 1-mercapto-1,1-ethanediol, 3-mercapto-1,2-propanediol (thioglycerol), 2-mercapto-1,2. Examples thereof include mercaptans such as −propanediol, lauryl mercaptan, and n-dodecyl mercaptan, α-methylstyrene dimer, and limonene. By using the chain transfer agent in combination, the amount of the residual initiator can be reduced, and the risk of gelation during the preparation of the resin (A) can be reduced.

The amount of the chain transfer agent used is 0.1 with respect to 100 parts by weight of the total of the ethylenically unsaturated monomer (a1) having two or more unsaturated double bonds and the other ethylenically unsaturated monomer. It is preferably ~ 20 parts by weight, more preferably 0.3 to 10 parts by weight, still more preferably 3 to 6 parts by weight. Within the above range, an ink having a well-balanced physical properties such as dispersibility and tack can be obtained. The reaction temperature is 40 to 150 ° C, preferably 50 to 110 ° C.

In the case of solution polymerization, an ethylenically unsaturated monomer (a1) having two or more unsaturated double bonds and an ethylenically unsaturated monomer containing another ethylenically unsaturated monomer are organically prepared. A solution of the resin (A) is produced by copolymerizing in the solvent (F). As the organic solvent (F), ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, xylene, acetone, hexane, methyl ethyl ketone, cyclohexanone, methanol, ethanol, diethylene glycol diethyl ether and the like are used, but are particularly limited thereto. is not it. Two or more of these polymerization solvents may be mixed and used, but a solvent having a low boiling point is preferable because it is removed by replacing with the active energy ray-curable compound (b1) at the time of producing the varnish (G). ..

<Varnish for active energy ray-curable lithographic printing ink (G)>
When producing the ink, it is preferable to use it in the form of a varnish containing the resin (A) and the active energy ray-curable compound (b1). Examples of the active energy ray-curable compound (b1) include the same as those described in the active energy ray-curable compound (B) described later. The active energy ray-curable compound (b1) may be the same as or different from the active energy ray-curable compound (B).

The method for producing the varnish (G) for active energy ray-curable flat plate printing ink is not particularly limited, but as a preferable production method, the ethylenically unsaturated monomer (a1) having two or more unsaturated double bonds is 0. A resin (A) is produced by copolymerizing an ethylenically unsaturated monomer containing 5 to 25% by weight and 75 to 99.5% by weight of other ethylenically unsaturated monomers in an organic solvent (F). A method including a step X of adding the active energy ray-curable compound (b1) to the solution of the resin (A) and then removing the organic solvent (F) can be mentioned.
More specifically, it is a method of adding an active energy ray-curable compound (B) and a banning agent to a solution of the resin (A), mixing them, and then heating to remove the organic solvent (F). The temperature at the time of removal is preferably 50 to 130 ° C, more preferably 70 to 110 ° C. If necessary, the pressure inside the system may be reduced.

<Molecular weight of resin (A)>
By copolymerizing an ethylenically unsaturated monomer (a1) having two or more unsaturated double bonds, an acrylic resin having a branched structure (crosslinked structure) in the molecule is obtained, and this structure emulsifies the ink. It is considered that it contributes to aptitude.

The fact that the resin has a branched structure can also be expressed by the ratio of the weight average absolute molecular weight (LS_Mw) to the weight average relative molecular weight, and the weight average absolute molecular weight (LS_Mw) / weight average relative molecular weight is 2 to 20. It is preferable, and more preferably 2.5 to 16. The weight average absolute molecular weight (LS_Mw) of the resin (A) is preferably 10,000 to 5,000,000, more preferably 30,000 to 4,000,000, and 200,000. It is particularly preferably ~ 4,000,000.
When it is within the above range, it is preferable because it is excellent in emulsification suitability, transferability, curability and the like when it is made into a printing ink.

The weight average absolute molecular weight (LS_Mw) is measured using a multi-angle light scattering detector, and is the general weight average molecular weight (weight average relative molecular weight (RI_Mw)) measured using a differential refractometer detector. Is different. Since the weight average relative molecular weight of the resin having the branched structure is detected to be smaller than the weight average absolute molecular weight of the resin having the branched structure, the value of the weight average absolute molecular weight / weight average relative molecular weight is It is an index showing the branched structure of the molecule.

<Active energy ray-curable compound (B)>
The active energy ray-curable compound (B) in the present invention is not particularly limited as long as it is a compound that is cured by irradiation with active energy rays such as ultraviolet rays and electron beams, and has an unsaturated double bond in the molecule. Examples include compounds having. Specific examples of the active energy ray-curable compound include the following ethylenically unsaturated monomers.

Examples of the monofunctional ethylenically unsaturated monomer include alkylphenols (butylphenol, octylphenol, nonylphenol, dodecylphenol, etc.), (meth) acrylates of ethylene oxide adducts, and isobornyl (meth) acrylates, in addition to those exemplified above. , Tricyclodecanemonomethylol (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxy Butyl (meth) acrylate, hydroxypentyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2-hydroxy-3-butoxypropyl (meth) acrylate, 2-hydroxy-3-methoxypropyl (meth) acrylate 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, Acryoloxyethyl phthalate, 2- (meth) acryloyloxyethyl-2-hydroxyethyl phthalate, 2- (meth) acryloyloxypropyl phthalate, β-carboxyethyl (meth) acrylate, (meth) acrylic acid dimer, ω -Carboxy-polycaprolactone mono (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, N-vinylpyrrolidone, N-vinylformamide, (meth) acryloylmorpholine and the like are exemplified.

The bifunctional or higher functional ethylenically unsaturated monomer is not particularly limited, and examples thereof include the same ones exemplified in the monomer (a1).

The active energy ray-curable compound (B) can be appropriately selected according to the required properties of the cured film, and if necessary, an active energy ray-curable oligomer such as polyester acrylate, polyurethane acrylate, or epoxy acrylate. Can also be used together.

<Pigment (C)>
Next, as the pigment (C), an inorganic pigment and an organic pigment can be shown. Inorganic pigments include yellow lead, zinc yellow, navy blue, barium sulfate, cadmium red, titanium oxide, zinc flower, petals, alumina white, calcium carbonate, ultramarine, carbon black, graphite, aluminum powder, etc., and organic pigments include β Soluble azo pigments such as -naphthol type, β-oxynaphthoic acid type, β-oxynaphthoic acid type allylide type, acetoacetate allylide type, pyrazolone type, β-naphthol type, β-oxynaphthoic acid type allylide type, acetoacetate allylide Insoluble azo pigments such as monoazo, acetacetate allylide dysazo, pyrazolone, copper phthalocyanine blue, halogenated (chlorine or brominated) copper phthalocyanine blue, sulfonated copper phthalocyanine blue, metal-free phthalocyanine and other phthalocyanine pigments, quinacridone , Dioxazine-based, Slen-based (Pyrantron, Antanthron, Indantron, Antrapyrimidine, Flavantron, Thioindigo-based, Anthraquinone-based, Perinone-based, Perylene-based, etc.), Isoindrinone-based, Metal complex-based, Kinoftalone-based polycycle Various publicly known and public pigments such as formula pigments and heterocyclic pigments can be used.

<Photopolymerization initiator (D), sensitizer>
When the active energy ray-curable lithographic offset printing ink of the present invention uses ultraviolet rays, it is necessary to add a photopolymerization initiator and a sensitizer. The photopolymerization initiator can be roughly classified into two types: one in which a bond is cleaved in a molecule by light to generate an active species, and the other in which a hydrogen abstraction reaction occurs between molecules to produce an active species.

Examples of the former include, for example, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, diethoxyacetophenone, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2). -Propyl) ketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-hydroxy-2-methyl-1-phenyl-propane-1-one, 1-hydroxy-cyclohexyl-phenyl Ketone, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, benzyl dimethyl ketal, oligo {2-hydroxy-2-methyl-1- [ 4- (1-Methylvinyl) phenyl] propane}, acetophenone such as 4- (2-acryloyl-oxyethoxy) phenyl-2-hydroxy-2-propylketone, benzoin such as benzoin, benzoin isopropyl ether and benzoin isobutyl ether Acryphosphine oxides such as the system, a mixture of 1-hydroxycyclohexyl-phenylketone and benzophenone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide. There are systems, benzyl, methylphenylglioxyester, 3,3', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone and the like.

Examples of the latter include benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4,4'-dichlorobenzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyl-diphenylsulfide, acrylicized benzophenone, 3,3. Benzophenones such as', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, 3,3'-dimethyl-4-methoxybenzophenone, 2-isopropylthioxanthone, 2,4-dimethylthioxanthone, 2,4- Thioxanthone series such as diethylthioxanthone and 2,4-dichlorothioxanthone, Michler ketone, aminobenzophenone series such as 4,4'-bisdiethylaminobenzophenone, 10-butyl-2-chloroacrydone, 2-ethylanthraquinone, 9,10- There are phenanthrene quinone, benzophenone, etc. These photopolymerization initiators may be used alone or in combination of two or more as required.

When the active energy ray-curable lithographic offset printing ink of the present invention is cured by irradiating it with ultraviolet rays, it is cured only by adding a photopolymerization initiator, but in order to further improve the curability, a photosensitizer is used in combination. You can also do it. Examples of such photosensitizers include triethanolamine, methyldiethanolamine, dimethylethanolamine, triisopropanolamine, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, and benzoate. There are amines such as acid (2-dimethylamino) ethyl, 4-dimethylaminobenzoic acid (n-butoxy) ethyl, 4-dimethylaminobenzoate 2-ethylhexyl and the like.

The blending amount of the photopolymerization initiator is 0.01 to 20% by weight, preferably 0.05 to 10% by weight in the printing ink. If it is less than 0.01% by weight, it is difficult to sufficiently carry out the curing reaction, and if it exceeds 20 parts by weight, a thermal polymerization reaction is likely to occur and the stability of the ink is likely to be impaired, which is not preferable.

<Other additive ingredients>
Further, the active energy ray-curable lithographic offset printing ink of the present invention can use other additives as needed. For example, as additives that impart abrasion resistance, blocking prevention, slipperiness, and scratch prevention, natural waxes such as carnauba wax, wood wax, lanolin, montan wax, paraffin wax, and microcrystallin wax, and Fishertropus wax. , Polyethylene wax, Polypropylene wax, Polytetrafluoroethylene wax, Polyamide wax, Synthetic wax such as silicone compound and the like can be exemplified.

For example, as additives that impart storage stability of ink, (alkyl) phenol, hydroquinone, catechol, resorcin, p-methoxyphenol, t-butylcatechol, t-butylhydroquinone, pyrogallol, 1,1-picrylhydra. Zyl, phenothiline, p-benzoquinone, nitrosobenzene, 2,5-di-tert-butyl-p-benzoquinone, dithiobenzoyl disulfide, picric acid, cuperon, aluminum N-nitrosophenylhydroxylamine, tri-p-nitrophenylmethyl, Examples thereof include polymerization inhibitors such as N- (3-oxyanilino-1,3-dimethylbutylidene) aniline oxide, dibutyl cresol, cyclohexanone oxime cresol, guayacol, o-isopropylphenol, butyraldoxime, methyl ethyl ketoxim, and cyclohexanone oxime.

In addition, additives such as an ultraviolet absorber, an infrared absorber, and an antibacterial agent can be added according to the required performance.

<Ink manufacturing method>
The active energy ray-curable lithographic offset printing ink of the present invention can be used for kneading, mixing, and adjusting printing ink components such as kneaders, three rolls, attritors, sand mills, and gate mixers between room temperature and 100 ° C. Manufactured using.

<Printed matter>
The above-mentioned active energy ray-curable lithographic printing ink can be printed on a substrate and cured by the active energy ray to obtain a printed matter.
The active energy ray-curable lithographic printing ink of the present invention is usually applied to lithographic printing using dampening water, but is also suitably used for waterless printing using dampening water. The active energy ray-curable slab printing ink of the present invention includes foam printed matter, various book printed matter, various packaging printed matter such as carton paper, various plastic printed matter, seal / label printed matter, art printed matter, metal printed matter (art printed matter, art printed matter, It is applied to printed matter such as beverage can printed matter and food printed matter such as canned matter). It may also be used as an overcoat varnish.

As the base material, uncoated paper such as high-quality paper, finely coated paper, art paper, coated paper, lightweight coated paper, coated paper such as cast coated paper, white paperboard, boardboard such as ball coat, synthetic paper, etc. Examples include aluminum coated paper and plastic sheets such as polypropylene, polyethylene, polyethylene terephthalate, and polyvinyl chloride.

The atmosphere for irradiating the active energy rays is preferably an atmosphere in which an inert gas such as nitrogen gas is substituted, but there is no problem even if the atmosphere is irradiated in the air as long as there is no problem in curability. Before irradiating the active energy ray, the active energy ray-curable composition layer is heated with an infrared heater or the like, or after the active energy ray is irradiated, the active energy ray-curable slab printing ink curing layer is heated with an infrared heater or the like. This is effective for terminating curing quickly.

The active energy rays of the present invention refer to ionizing radiation such as ultraviolet rays, electron beams, X-rays, α rays, β rays and γ rays, microwaves, high frequencies, etc., if radically active species can be generated. It can be of any energy type, visible light, ultraviolet light, or laser light. Examples of those that generate ultraviolet rays include ultra-high pressure mercury lamps, high pressure mercury lamps, medium pressure mercury lamps, low pressure mercury lamps, metal halide lamps, xenon lamps, carbon arc lamps, helium / cadmium lasers, YAG lasers, excima lasers, and argon lasers. and so on.

Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. In the present invention, "part" represents a part by weight, and "%" represents% by weight.

(Average molecular weight of resin (A))
In the present invention, the weight average relative molecular weight (RI_Mw) is an eluent using HLC-8220GPC (manufactured by Tosoh Corporation) equipped with an RI detector as an apparatus and TSKgel SUPER HZM-N (manufactured by Tosoh Corporation) as a column. It is a polystyrene-equivalent weight average molecular weight (RI_Mw) measured using tetrahydrofuran. For the weight average absolute molecular weight (LS_Mw), Alliance GPC (manufactured by Waters) was used as an apparatus, TSKgel GMH HR-H (manufactured by Tosoh) was used as a column, and mini DAWN TREOS, ViscoSterII, Optilab T-rEX were used as detectors. (All manufactured by Water Technology), and the measurement was carried out using THF as an eluent.

[Example 1]
In a reaction vessel equipped with a gas introduction tube, a thermometer, a condenser, and a stirrer, 97 parts of benzyl methacrylate, 3 parts of tripropylene glycol diacrylate, 25 parts of methyl ethyl ketone, and 1 part of 3-mercapto-1,2-propanediol were charged. Replaced with nitrogen gas. The inside of the reaction vessel is heated to 90 ° C., 0.1 part of 2,2'-azobisisobutyronitrile dissolved in 58 parts of methyl ethyl ketone is added in 13 portions every 30 minutes, and the temperature remains at 90 ° C. The reaction was carried out for 7 hours to obtain a resin (R1) having a weight average relative molecular weight (RI_Mw) of 250,000 and a weight average absolute molecular weight (LS_Mw) of 1.83 million. The resin (A) solution was adjusted so that the solid content was 55% by weight.
Next, 45 parts of the resin (R1) solution, 75 parts of dipentaerythritol hexaacrylate, and 0.1 part of hydroquinone were mixed in the same flask, and the inside of the reaction vessel was heated to 100 ° C. to distill off methyl ethyl ketone to distill off the varnish. Was adjusted with dipentaerythritol hexaacrylate so that the viscosity of the varnish was 270 to 330 Pa · s, and a solvent-free varnish (V1) was obtained.
The viscosity of the varnish was measured using Rheo Stress 6000 manufactured by HAAKE, and the value at 100 sec ^{-1 when the shear rate was changed from 0 to 120 sec -1 at 25 ° C. was measured.}
Furthermore, 20 parts of Lionol Blue FG7330 (indigo pigment manufactured by Toyo Color Co., Ltd.), 60 parts of varnish (V1), 14.9 parts of ditrimethylolpropane tetraacrylate, 2.5 parts of 4,4'-bis (diethylamino) benzophenone, 2.5 parts of Irgacure 907 (manufactured by BASF) and 0.1 part of hydroquinone are kneaded with a three-roll mill at 40 ° C., and adjusted with ditrimethylolpropane tetraacrylate so that the ink tack becomes 9 to 10. , A flat plate printing ink (C1) was obtained.
The ink tack was measured with a digital incometer manufactured by Toyo Seiki Co., Ltd. at a roll temperature of 30 ° C., 400 rpm, and a value after 1 minute.

[Examples 2-36, Comparative Examples A-C]
A resin, a varnish, and a lithographic printing ink were obtained with the compounding compositions shown in Tables 1 and 2 by the same operation as in Example 1.

The lithographic printing inks obtained in Examples and Comparative Examples were evaluated for dispersibility, fluidity, emulsification suitability (printability), and gloss value by the following methods. The evaluation results are shown in Tables 1 and 2.

<Dispersibility evaluation>
Using a grind meter (manufactured by Nippon Cedars Service Co., Ltd.), according to the JIS K5701-1: 2000 kneading degree measurement method, three or more continuous lines of 10 mm or more generated by pulling the scraper are per groove. It was measured as the scale position A when it appeared and the scale position B where 10 or more appeared, and evaluated in the following four stages. The lower the number, the better.
(Evaluation criteria)
⊚: A value = 5.0 μm or less and B value = 5.0 μm or less ◯: A value = 7.5 μm or less and B value = 5.0 μm or less Δ: A value = 7.5 μm or less and B value = 7.5 μm X: A value = greater than 7.5 μm and B value = greater than 5.0 μm

<Liquidity evaluation>
Measured according to the JIS K5701: 2000 fluidity measurement method by the spread meter method, the ink sandwiched between two horizontally placed parallel plates spreads concentrically due to the weight of the load plate (115 grams). Was observed over time, and the spread diameter [mm] of the ink after 60 seconds was evaluated in the following three stages. The higher the value, the better.
(Evaluation criteria)
⊚: 34.0 mm or more ○: 32.0 mm or more Δ: 30.0 mm or more ×: less than 30.0 mm

<Emulsification suitability>
The emulsification suitability was as follows.
Viscoelasticity: The torque required for stirring when 10% water was forcibly emulsified in the ink was measured, and the torque reduction rate before and after emulsification was evaluated in the following three stages. The larger the torque reduction rate, the better the printability because the viscoelasticity can be maintained during emulsification.
(Evaluation criteria)
A: 60% or more B: 50% or more to less than 60% C: less than 50% Fluidity: The fluidity when 10% of water is forcibly emulsified in the ink is measured by the spread meter method, JIS K5701: 2000 flow. The measurement was performed according to the sex measurement method, and the fluidity change width [mm] before and after emulsification was evaluated in the following three stages. The smaller the change in fluidity, the better the printability because the fluidity can be maintained during emulsification.
(Evaluation criteria)
A: Less than 2.0 mm B: 2.0 mm or more and less than 4.0 mm C: 4.0 mm or more As the printability evaluation, the above viscoelasticity and fluidity evaluations were comprehensively judged and evaluated in the following four stages.
(Evaluation criteria)
⊚: A rating (extremely good) for both viscoelasticity and fluidity
◯: B evaluation (good) for either viscoelasticity or fluidity, or both
Δ: Either viscoelasticity or fluidity is evaluated as C (usable)
×: Both viscoelasticity and fluidity are evaluated as C (impossible)

<Gloss value>
A proof bow color spreader was used to spread the color on a pearl coat manufactured by Mitsubishi Paper Mills Limited at the same concentration, and a gloss meter gloss meter model GM-26 (manufactured by Murakami Color Technology Research Institute Co., Ltd.) was used to measure the gloss at 60 °. The higher the value, the better the gloss.
(Evaluation criteria)
⊚: 60 or more ○: 50 or more and less than 60 Δ: 40 or more and less than 50 ×: less than 40

<Tack>
The tack value was measured with an incometer under the conditions of 30 ° C., a rotation speed of 400 rpm, and a measurement time of 1 minute. The lower the value, the better the misting property.
(Evaluation criteria)
⊚: less than 9.0 ○: 9.0 or more and less than 10.0 Δ: 10.0 or more and less than 11.0 ×: 11.0 or more

Details of the compounds listed in Table 2 are shown below.
Trimethylolpropane EO-modified triacrylate; trimethylolpropane ethylene oxide (3 mol) adduct triacrylate diglycerin EO-modified tetraacrylate; diglycerin ethylene oxide (4 mol) adduct tetraacrylate pentaerythritol EO Modified tetraacrylate; tetraacrylate of ethylene oxide (4 mol) adduct of pentaerythritol

From the results of Tables 1 and 2, according to the examples of the present invention, 0.5 to 25% by weight of the ethylenically unsaturated monomer having two or more unsaturated double bonds and ethylenically unsaturated It was found that the active energy ray-curable flat plate printing ink using a resin obtained by copolymerizing 75 to 99.5% by weight of a monomer has relatively good dispersibility, fluidity, and emulsification suitability. It was. Furthermore, from the comparison of Examples 10 to 13 and Examples 14 to 19, when the other ethylenically unsaturated monomer contains an ethylenically unsaturated monomer having an aromatic ring, good dispersibility and fluidity are obtained. , Emulsification suitability, and gloss value were found.

Further, from the comparison of Examples 1 to 8 and 20 to 36, it can be seen that when the amount of the chain transfer agent is large, the tack (misching property) is excellent. From Examples 30 to 36, the number of unsaturated double bonds of the ethylenically unsaturated monomer (a1) is large, and the more hydrophobic (not containing the ethylene oxide structure), the better the balance of tack and all performances. Understand.

The following can be seen in the comparative example.
(I) Table 1 (Comparative Examples A and B)
It can be seen that the emulsification suitability is inferior when the ethylenically unsaturated monomer having two or more unsaturated double bonds is not used.
(II) Table 1 (Comparative Example C)
When the ethylenically unsaturated monomer having two or more unsaturated double bonds and the ethylenically unsaturated monomer having an aromatic ring are not used, the dispersibility, fluidity, emulsification suitability, and gloss value are Both turned out to be inferior.

Claims (4)

0.5 to 15 % by weight of ethylenically unsaturated monomer (a1) having two or more unsaturated double bonds (except when four or more ), and other ethylenically unsaturated single amounts An active energy ray-curable type containing an active energy ray-curable compound (B) and a resin (A) obtained by copolymerizing an ethylenically unsaturated monomer containing 85 to 99.5% by weight of the body. a lithographic printing ink,
The other ethylenically unsaturated monomer contains an ethylenically unsaturated monomer (a2) having an aromatic ring.
The weight average absolute molecular weight of the resin (A) is 10,000 to 4,000,000.
An active energy ray-curable lithographic printing ink in which the ratio of the weight average absolute molecular weight to the weight average relative molecular weight is 2 to 20. The active energy ray-curable lithographic printing ink according to claim 1 , further containing a pigment (C). The active energy ray-curable lithographic printing ink according to claim 1 or 2 , further containing a photopolymerization initiator (D). A printed matter obtained by printing the active energy ray-curable lithographic printing ink according to any one of claims 1 to 3 on a substrate and curing the printed matter with the active energy rays.