JP6514836B2 - Active energy ray curable printing ink composition and printing method using the same - Google Patents

Description

  The present invention relates to an active energy ray-curable printing ink composition, a printed matter using the same, and a printing method.

  The outer surface of a metal can such as a beverage can or a food can is provided with a display or decoration of contents. As one of methods for performing such display and decoration, a method is known in which a printing layer and an overcoat layer are formed on a metal plate by an offset method and then molding is performed. Cans produced by such a method are referred to as DR cans and two-piece cans.

  As an ink composition suitable for such a use, an active energy ray curable metal printing ink composition as disclosed in, for example, Patent Documents 1 and 2 is known. The active energy ray curable metal printing ink composition has a faster curing speed of the printing layer than the thermosetting metal printing ink composition, and is excellent in productivity.

Patent document 1: JP-A-2001-002969 Japanese Patent Application Publication No. 2003-012974

  On the other hand, the active energy ray-curable metal printing ink composition is inferior to the thermosetting metal printing ink composition in the processability after printing. As an example, in the process of producing a beverage can, food can, etc., a heat treatment process such as retort treatment for sterilization and long-term storage is involved, but when printing is performed using an active energy ray-curable metal printing ink composition In some cases, micro-cracks may occur in the printed layer or overcoat layer on the outer surface of the can after molding or retort treatment to reduce the gloss or cause whitening.

  The present invention has been made to solve at least a part of such problems, and is excellent in processability after printing, and capable of suppressing the occurrence of microcracks and whitening after molding and retort treatment. An object of the present invention is to provide an energy ray-curable printing ink composition. Another object of the present invention is to provide a printing method for obtaining a printed matter which is excellent in processability and in which occurrence of microcracks and whitening hardly occurs after retort treatment, and a printed matter obtained by the printing method.

  The present invention comprises a pigment, a resin, an active energy ray curable monomer, an acid catalyst, and a photopolymerization initiator, and the acid catalyst comprises alkyl aryl sulfonic acid, alkyl aryl sulfonic acid salt, alkyl phosphoric acid The present invention relates to an active energy ray-curable printing ink composition comprising at least one selected from the group consisting of

  The present invention also provides a process of forming a printing layer using the above-mentioned active energy ray-curable printing ink composition, and an overcoat varnish composition comprising a polyester resin and an amino resin on the printing layer. And (e) forming a coat layer.

The present invention also relates to a printed material produced by the above printing method.
The present invention also relates to a printed matter comprising a printing layer formed using the above-mentioned active energy ray-curable printing ink composition on a substrate.

  The active energy ray-curable printing ink composition of the present invention is excellent in processability after printing, and can suppress the occurrence of microcracks and whitening after molding and retort treatment. Further, according to the printing method of the present invention, it is possible to provide a printed material which is excellent in processability and in which the occurrence of whitening is suppressed. According to the printed matter of the present invention, since the processability is excellent and the whitening is suppressed, the productivity can be improved.

<Active energy ray-curable printing ink composition>
The active energy ray-curable printing ink composition of the present invention comprises a pigment, a resin, an active energy ray-curable monomer, an acid catalyst, and a photopolymerization initiator. You may add a photosensitizer and other adjuvants as needed.

  As the pigment, optional inorganic and organic pigments can be used as needed, and there is no particular limitation. Examples of yellow pigments of process color include disazo, condensation azo, etc., magenta pigments include azo lake, quinacridone, diketopyrrolopyrrole, etc., cyan pigments include phthalocyanine, etc., and black pigments such as carbon black. The addition amount may be in the range of 5% by mass to 60% by mass in the active energy ray-curable printing ink composition.

  As the resin, any resin used for active energy ray-curable printing ink composition can be used, and rosin modified phenolic resin, rosin modified alkyd resin, rosin ester resin, fatty acid modified alkyd resin, silicon modified alkyd resin, oil free ester Resin, urethane modified ester resin, epoxy resin, epoxy ester resin, ketone resin, acrylic resin, diallyl phthalate resin, rosin modified maleic resin, epoxy acrylate resin, urethane acrylate resin, polyester acrylate resin, alkyd acrylate resin and the like can be exemplified. These resins can be used alone or in combination.

  The resin used in the active energy ray-curable printing ink composition of the present invention is preferably a rosin ester resin, more preferably a hydrogenated rosin ester resin (hereinafter also referred to as a hydrogenated rosin ester resin), and hydrogenated It is more preferable to use the rosin ester resin and the urethane acrylate resin in combination. It may further contain other resins. Hydrogenation can improve the storage stability of the ink. Furthermore, by using the hydrogenated rosin ester resin and the urethane acrylate resin in combination, appropriate flexibility can be imparted to the printing layer formed using the active energy ray-curable printing ink composition of the present invention. , Processability is improved.

  The urethane acrylate resin is a resin obtained by modifying the terminal of a urethane resin obtained by condensation of an isocyanate group-containing monomer and a hydroxyl group-containing monomer with an acryl group or a methacryl group. As a urethane acrylate resin used for the active energy ray hardening-type printing ink composition of this invention, the bifunctional urethane acrylate resin which modified both ends with the acryl group or the methacryl group is especially preferable. Thereby, it can be set as the active energy ray hardening-type printing ink composition excellent in the balance of processability and curability.

  The addition amount of the resin is arbitrary, and 5% by mass or more of the total amount of the active energy ray curable printing ink composition according to the concentration of the pigment contained in the active energy ray curable printing ink composition and the viscosity of the ink composition. It adjusts in 80 mass% or less.

Furthermore, when using hydrogenated rosin ester resin and urethane acrylate resin together as resin, the usage-amount of hydrogenated rosin ester may be 8 mass% or more and 30 mass% or less of the active energy ray-curable printing ink composition. preferable. The amount of the urethane acrylate resin used is preferably 10% by mass or more and 30% by mass or less of the active energy ray-curable printing ink composition.
In this way, it is possible to obtain an appropriate film hardness that can withstand elongation processing by press processing or the like while preventing damage or the like during processing or the like.

  The active energy ray curable monomer used in the active energy ray curable printing ink composition of the present invention may be used alone or in combination of a plurality of monomers which are cured by irradiation of active energy rays such as ultraviolet rays and electron beams, There is no limit. Phenol acrylate and its ethylene or propylene oxide modified product, nonyl phenol acrylate and its ethylene or propylene oxide modified product, bisphenol F diacrylate and its ethylene or propylene oxide modified product, bisphenol A diacrylate and its ethylene or propylene oxide modified product, ethylene glycol Diacrylate, butylene glycol diacrylate, propylene glycol diacrylate, pentanediol diacrylate, hexanediol diacrylate, neopentyl glycol diacrylate, heptanediol diacrylate, octanediol diacrylate, nonanediol diacrylate, decanediol diacrylate, butyl Ethyl propane diol diac Rate, pentaerythritol triacrylate and its ethylene or propylene oxide modified product, trimethylolpropane triacrylate and its ethylene or propylene oxide modified product, pentaerythritol tetraacrylate and its ethylene or propylene oxide modified product, dipentaerythritol penta and hexa Acrylate and its ethylene or propylene oxide modified product, ditrimethylolpropane tetraacrylate and its ethylene or propylene oxide modified product, aliphatic modified acrylate and its ethylene or propylene oxide modified product, etc. can be exemplified. The active energy ray curable monomer may be added in the range of 5% by mass to 50% by mass with respect to the total amount of the active energy ray curable printing ink composition.

  Among them, the active energy ray curable monomer used in the active energy ray curable printing ink composition of the present invention preferably contains a (meth) acrylate having a cyclic structure, and contains a monofunctional (meth) acrylate. More preferable. The cyclic structure may be monocyclic or polycyclic, and may be aromatic or alicyclic. It may be a heterocycle.

  In particular, by using a hydrogenated rosin ester resin and a urethane acrylate resin in combination as a resin, and using a monofunctional (meth) acrylate having a cyclic structure as an active energy ray curable monomer, the printing layer may be damaged during processing, etc. The occurrence of micro cracks during molding can be suppressed, and the balance between curability and processability can be made suitable for metal printing.

  Examples of monofunctional (meth) acrylates having such a cyclic structure include isobornyl (meth) acrylate, neopentyl glycol acrylic acid benzoate, phenol ethoxy acrylate, nonyl phenol ethoxy acrylate, acryloyl morpholine, 4-t-butyl cyclohexyl acrylate Etc. Among them, neopentyl glycol acrylic acid benzoate, phenol ethoxy acrylate and nonyl phenol ethoxy acrylate are preferably used.

  The monofunctional (meth) acrylate having such a cyclic structure is preferably used in a range of 3% by mass to 50% by mass with respect to the total amount of the active energy ray-curable printing ink composition, and 5% by mass It is more preferable to use in the range of 30 mass% or less.

  The active energy ray-curable printing ink composition of the present invention contains at least one selected from the group consisting of alkyl aryl sulfonic acid, alkyl aryl sulfonate and alkyl phosphoric acid as an acid catalyst. It is more preferable to include at least one of an alkylaryl sulfonic acid or an alkylaryl sulfonate because whitening can be suppressed more effectively. As an alkyl group with which an acid catalyst is equipped, a C1-C18 linear alkyl group is mentioned. Examples of the aryl group include benzene and naphthalene.

  Examples of such alkyl aryl sulfonic acid include dodecyl benzene sulfonic acid, butyl naphthalene sulfonic acid, dinonyl naphthalene sulfonic acid, p-toluene sulfonic acid and xylene sulfonic acid. Examples of the alkyl aryl sulfonate include salts of the alkyl aryl sulfonic acid as described above with sodium, potassium, zinc, ammonia, triethanolamine and the like, and salts with sodium, zinc, ammonia are preferably used. Among these, it is particularly preferable to use at least one selected from sodium salt, zinc salt, ammonium salt, xylene sulfonic acid and paratoluene sulfonic acid of dodecylbenzenesulfonic acid.

  The content of the acid catalyst is preferably 0.1% by mass or more and 2.0% by mass or less, and more preferably 0.15% by mass or more and 1.5% by mass, based on the total amount of the active energy ray-curable printing ink composition. The content is more preferably 0.2% by mass or more and 1.0% by mass or less. By adding 0.1% by mass or more of the acid catalyst to the active energy ray-curable printing ink composition, it is possible to effectively suppress the whitening of the printed matter after the retort treatment. Although the effect of suppressing the whitening of the printed matter and the curability of the ink coating film improve as the addition amount of the acid catalyst increases, the increase in the addition amount makes the ink difficult to transfer during printing, so the whitening suppression effect It is preferable to set it as 2.0 mass% or less in consideration of the balance with and printability.

  When the active energy ray-curable printing ink composition of the present invention is cured using ultraviolet light, it is necessary to add a photopolymerization initiator and a photosensitizer. As the photopolymerization initiator, any substance capable of generating a radical by ultraviolet light may be used alone or in combination and there may be no particular limitation. Benzoin ether, benzyl ketal, acetophenone derivative, acyl phosphine oxide, α-dicarbonyl, aromatic ketone, thioxanthone, 4,4 dimethylamino benzophenone, 4,4 diethylamino benzophenone, α-acyloxime ester, Irgacure 907 (Ciba Geigy And Irgacure 369 (manufactured by Ciba Geigy). The addition amount of the photopolymerization initiator may be added in the range of 0.1% by mass to 20% by mass in the active energy ray-curable printing ink composition.

  The photosensitizer used in the active energy ray-curable printing ink composition of the present invention is not particularly limited, as it can be used alone or in combination of two or more arbitrary substances which reduce oxygen damage at the time of ultraviolet curing. (Mono, di, tri) ethanolamine, (mono, di) methyl (mono, di) ethanolamine, (mono, di, tri) propanolamine, (mono, di) methyl amino benzaldehyde, (mono, di) methyl amino Benzoic acid, butyl (mono, di) methylaminobenzoate, ethyl (mono, di) methylaminobenzoate, ethyl (mono, di) methylaminobenzoate, butyl (mono, di) methylaminobenzoate, (mono, Examples may include: di) isoamyl methylaminobenzoate; dimethylaminoethyl benzoate; butoxyethyl (mono, di) methylaminobenzoate; and ethylhexyl (mono, di) methylaminobenzoate. The photosensitizer used for the active energy ray curable printing ink composition of this invention can be used individually or in mixture of multiple. The addition amount of the photosensitizer may be added in the range of 1% by mass to 10% by mass in the active energy ray-curable printing ink composition.

  In addition to the above constitution, the active energy ray-curable printing ink composition of the present invention preferably contains one or more organic compounds selected from polyethylene glycol, polypropylene glycol, ethylene propylene glycol copolymer and fatty acid ester.

  The fatty acid ester is an ester compound of polyhydric alcohol and fatty acid. Arbitrary trivalent or higher polyhydric alcohols and fatty acids can be used without limitation, but examples of polyhydric alcohols include glycerin, trimethylol ethane, trimethylol propane, pentaerythritol, dipentaerythritol, etc. Can be used. Further, considering the transferability of the ink, sorbitan obtained by heat-dehydrating sorbitol is preferable as the polyhydric alcohol. As fatty acid, linseed oil fatty acid, tung oil fatty acid, dehydrated castor oil fatty acid, soybean oil fatty acid, safflower oil fatty acid, nuka oil fatty acid, tall oil fatty acid, castor oil fatty acid, palm oil fatty acid, coconut oil fatty acid, pelargonic acid, caprine Examples of acids, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, margaric acid, stearic acid, isostearic acid, oleic acid, linoleic acid, linolenic acid, etc. can be used alone or in combination. The addition amount is preferably in the range of 2% by mass or more and 20% by mass or less in the active energy ray-curable printing ink composition. If it is less than 2% by mass, it is difficult to obtain the improvement of processability, and if it exceeds 20% by mass, the curability by ultraviolet rays tends to be lowered, and the overprinting property tends to be lowered. More preferably, it is 5% by mass and 15% by mass or less, still more preferably 7% by mass or more and 12% by mass or less.

  In the active energy ray-curable printing ink composition of the present invention, in addition to the above-mentioned pigment, resin, photopolymerization initiator, photosensitizer, active energy ray-curable monomer, an auxiliary agent is optionally used in combination You can do it. As the auxiliary agent, a pigment dispersant, a dryer, a filler such as wax or an extender pigment, an auxiliary resin, an auxiliary solvent and the like can be mentioned.

<Overcoat varnish composition>
In the production of DR cans, it is common to apply a top coat using an overcoat varnish composition to protect the surface and improve the appearance of the printed layer. As such an overcoat varnish composition, any water-based, solvent-type, energy ray-curable overcoat varnish composition used in a conventional metal printing coating which is cured by heating or active energy rays can be exemplified.

  Among them, the active energy ray-curable printing ink composition of the present invention is preferably used in combination with a solvent type overcoat varnish composition containing a polyester resin and an amino resin. As a result, the printed matter described later can be processed with excellent whiteness and suppressed whitening.

  The polyester resin used in the overcoat varnish composition is obtained by the polycondensation reaction of a polybasic acid and a polyhydric alcohol, and may be linear or branched, and may be linear or branched. And may be used in combination.

  Examples of dibasic acids that can be used for the synthesis of linear polyester resins include aromatic dibasic acids such as terephthalic acid, isophthalic acid and phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride and 1,4-cyclohexanedicarboxylic acid And aliphatic dibasic acids such as (anhydride) succinic acid, fumaric acid, (anhydride) maleic acid, adipic acid, sebacic acid, azelaic acid, hemic acid and the like.

  As a dihydric alcohol, ethylene glycol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol , 2-methyl-1, 8-octanediol, diethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol, 3-methyl-1,5-pentanediol, xylene glycol, 2-n-butyl-2-ethyl- 1,3-propanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2,2-diethyl-1,3-propanediol, hydrogenated bisphenol A And other aliphatic dihydric alcohols, versatic acid glycidyl ester, Lumpur corresponding compounds.

As a dibasic acid which can be used for the synthesis | combination of branched polyester resin, the thing similar to what is used for the synthesis | combination of linear polyester resin can be used. As other polybasic acids, (anhydride) trimellitic acid, trimesic acid, (anhydride) pyromellitic acid and the like can be mentioned.
As the dihydric alcohol, the same one as used in the synthesis of a linear polyester resin can be used. Other polyhydric alcohols include trimethylol ethane, trimethylol propane, glycerin, pentaerythritol and the like.

  The type and amount of polybasic acid and polyhydric alcohol used in the synthesis may be appropriately selected and adjusted in consideration of the degree of branching of the produced resin, the molecular weight, the hardness of the coating when it is formed, the flexibility and the like.

  The number average molecular weight of the linear polyester resin is preferably 1,000 or more and 10,000 or less. The number average molecular weight of the branched ester is preferably 1,000 or more and 3,000 or less. As a result, it is possible to provide the overcoat varnish composition with sufficient coating film performance (hardness, processability, retort resistance) and to suppress the decrease in the compatibility with the amino resin and the increase in the viscosity.

  The amino resin used in the overcoat varnish composition includes urea-formaldehyde-lower alcohol addition condensate, melamine-formaldehyde-lower alcohol addition condensate, benzoguanamine-formaldehyde-lower alcohol addition condensate, alkyl etherified melamine resin, alkyl etherification Benzoguanamine resin, alkyletherified melamine-benzoguanamine co-condensation resin, etc. may be mentioned, and one or more of these may be used in combination.

  Any solvent can be used without limitation as long as it can dilute polyester resin and amino resin. As an example, aromatic hydrocarbons such as toluene, xylene, Solvesso # 100, Solvesso # 150, aliphatic hydrocarbons such as hexane, heptane, octane, decane, methyl acetate, ethyl acetate, isopropyl acetate, butyl acetate, amyl acetate Esters such as ethyl formate and butyl propionate, alcohols such as methanol, ethanol, propanol, butanol, 2-ethylhexanol and ethylene glycol, ketones such as acetone, methyl ethyl ketone and cyclohexanone, dioxane, diethyl ether, tetrahydrofuran and the like Various solvents of cellosolves such as ethers, cellosolve acetate, ethyl cellosolve, butyl cellosolve and the like can be mentioned.

  To the overcoat varnish composition, an epoxy resin or the like may be added for the purpose of improving the adhesion to other resin components, for example, the underlying metal, as long as the compatibility with these components is not impaired. Various additives such as a curing catalyst, a leveling agent, and a lubricant can also be added.

  The overcoat varnish composition can be prepared by stirring and mixing the polyester resin, the amino resin, the solvent and the various additives as described above. The content of the polyester resin in the overcoat varnish composition is preferably 10% by mass to 50% by mass, and more preferably 30% by mass to 50% by mass. The content of the amino resin is preferably 5% by mass to 50% by mass, and more preferably 20% by mass to 40% by mass. Furthermore, it is preferable that the mixing ratio of polyester resin and amino resin is 2: 1 to 1: 1 in solid content ratio. Thereby, the hardness and processability of a coating film can be made into an appropriate range.

<Printing method, printed matter>
The printed matter of the present invention is printed on a substrate using the active energy ray-curable printing ink composition of the present invention and cured to form a printed layer, and then the overcoat varnish composition as described above is obtained. It is obtained by painting and curing.

  As the substrate, a metal material generally used for metal printing can be used without particular limitation. Tin plate, LTS (light coated steel), tin free steel, aluminum plate, etc. can be used. The base material may be coated with a size paint or a white coating paint in consideration of adhesion and processability.

  As a printing method of the active energy ray-curable printing ink composition of the present invention, there is no problem as long as it is a printing method that can obtain printing accuracy with dimensions and registration accuracy similar to those of lithographic offset printing generally used for metal printing. Although there is no particular limitation, resin letterpress offset printing or waterless planographic offset printing is preferable in consideration of the viscosity of the ink. Furthermore, lithographic offset printing using dampening water in combination is optimum. The feeding method of the metal plate that is the substrate is not a pusher method that applies force to one side of the plate and transports it, but a grip-to-grip method that supports and transports both sides of the plate prevents blanketing of the plate and rolling up of the plate In the sense of The ink film thickness is optional, but may be, for example, in the range of 0.3 μm to 6 μm.

  The plate used for printing the active energy ray-curable printing ink composition of the present invention is not particularly limited, but a plate generally called PS plate having both a hydrophilic portion and a lipophilic portion on an aluminum plate is preferable, among them PS plates having resistance to active energy ray-curable printing inks are preferred.

  When printing using a PS plate that uses dampening water in combination, a dampening water device is used in combination. As the dampening fluid device, either a continuous water absorption type or an indirect water absorption type can be used. Although isopropyl alcohol and / or its substitute can be added to the dampening water in any proportion, it is preferable to add in the range of 1% by mass to 20% by mass. Also, printing aids such as solution H can be added.

  The roller used for printing the active energy ray-curable printing ink composition of the present invention may be any of metal, resin, and rubber-based rollers, but a roller having resistance to active energy ray-curable printing ink Use is desirable.

  The blanket used for printing of the active energy ray hardening-type printing ink composition of this invention can use the blanket normally used for printing. It is desirable to use a blanket that is resistant to actinic radiation curable printing inks.

The means for curing the active energy ray-curable printing ink composition of the present invention can be achieved by heating, but it is preferable in terms of workability to carry out by active energy ray irradiation. Active energy rays include ultraviolet rays, electron beams, X-rays, ionizing radiation such as alpha rays, beta rays, and gamma rays, microwaves, high frequencies, etc., but any energy can be generated as long as radical active species can be generated. It may be visible light, infrared light, or laser light. In the present invention, for the sake of simplicity, it is preferable to cure by ultraviolet irradiation.
As an ultraviolet lamp for ultraviolet irradiation, any ultraviolet lamp usually used in metal printing can be used. Examples thereof include an electrodeed and / or electrodeless high pressure mercury lamp, a metal halide lamp, an ozoneless high pressure mercury lamp, an ozoneless metal halide lamp, a gallium lamp, a light emitting diode and the like. The conditions under which the ultraviolet light is irradiated are also usually metal printing and the conditions under which the active energy ray-curable printing ink composition is cured, and are not particularly specified. One to ten ultraviolet lamps capable of obtaining an ultraviolet intensity of 60 W / cm to 500 W / cm, a distance of 5 to 30 cm to the printing surface may be performed at a printing speed of 10 to 300 sheets / minute.

  In addition to overprinting the active energy ray curable printing ink composition of the present invention a plurality of times, a conventional active energy ray curable ink, oxidation polymerization type on the active energy ray curable printing ink composition of the present invention It is also possible to print at least one of the ink and the heat curable ink. Alternatively, it is possible to overprint the active energy ray curable printing ink composition of the present invention after printing at least one of a conventional active energy ray curable ink, an oxidative polymerization ink, and a heat curable ink. Even in the printing method of the above, whitening after retort processing can be suppressed. Coating after printing can also be performed as before, and there is no limitation.

  The overcoat varnish composition to be coated is a normal printed directly on the active energy ray-curable printing ink composition layer of the present invention, or overprinted on the active energy ray-curable printing ink composition layer of the present invention. After being coated through a printing layer of at least one of an active energy ray curable ink, an oxidative polymerization type ink, and a heat curable ink, heat drying or active energy ray irradiation is performed at 150 to 250 ° C. for 5 seconds to 15 minutes. Thereby, the coating film which is excellent in appearance, hardness, processability, and retort resistance can be formed.

The coating method of the overcoat varnish composition can be carried out by a usual coater method such as a roll type such as an alonix roll and a biaxial roll, a chamber type, a gravure type and a flexo type. Although the film thickness of the coating film of overcoat varnish composition is arbitrary, what is necessary is just to carry out, for example in 3-10 micrometers.
The printed matter obtained in this manner is excellent in processability such as molding, and can be considered to be microcracks and to suppress whitening after retort treatment.

  EXAMPLES Hereinafter, the present invention will be specifically described by way of examples in order to facilitate understanding of the present invention, but the present invention is not limited to the examples. In the examples, parts and% are based on mass unless otherwise specified.

1. Preparation of active energy ray-curable printing ink composition 1.1. Resin (hydrogenated rosin ester)
The esterification reaction and hydrogenation reaction were carried out with 85 parts of purified polymer rosin obtained by purifying and polymerizing gum rosin, 10 parts of pentaerythritol and 5 parts of glycerin in a conventional manner to obtain a hydrogenated rosin ester resin having an acid value of 15 and resin color 5 .
To 80 parts of the same resin, 20 parts of ALONIX M-220 (tripropylene glycol diacrylate manufactured by Toagosei Co., Ltd.) was added to make a liquid resin (prepared as a hydrogenated rosin ester solution) and used for preparation of the ink composition. .

(Urethane acrylate resin)
As the urethane acrylate resin, EBECRYL 8411 (manufactured by Daicel Ornex Co., Ltd., weight average molecular weight 12000, bifunctional urethane acrylate, containing 20% by mass of isobornyl acrylate) was used.

1.2. Preparation of Active Energy Ray-Curable Printing Ink Composition (Example 1)
First Gen Blue TGR-L (manufactured by DIC Corporation): 25 parts, Lucillin TPO (photopolymerization initiator manufactured by BASF Corp.): 4 parts, Kayacure EPA (photosensitizer manufactured by Nippon Kayaku): 2 parts, hydroquinone: 0 .5 parts, Nonionic LP-20R (Sorbitan fatty acid ester made by NOF Corporation): 8 parts, NAKURE 5225 (King Industries Co., Ltd. dodecylbenzenesulfonic acid amine salt, active ingredient 25%): 1 part, hydrogenated rosin ester solution: 20 Part B. 18 parts of urethane acrylate resin was added while stirring with a triple roll mill and light acrylate BA-104 (neopentyl glycol acrylic acid benzoate ester manufactured by Kyoeisha Co., Ltd.) was added. It adjusted to become V10 and the ink composition of Example 1 was obtained.

(Example 2-5)
An active energy ray-curable printing ink composition of Examples 2-5 was obtained in the same manner as in Example 1 except that the composition was changed as shown in Table 1.
(Comparative example 1-3)
An active energy ray-curable printing ink composition of Comparative Example 1-3 was obtained in the same manner as in Example 1 except that the composition was changed as shown in Table 1.

In addition, content of the hydrogenated rosin ester in Table 1 remove | eliminates Alonix M-220 from the quantity of the hydrogenated rosin ester solution used.
Similarly, the content of urethane acrylate is the amount of EBECRYL 8411 used minus the isobornyl acrylate (IBOA) contained therein.
NC 4167 in Table 1 is NATURE 4167 (alkyl phosphoric acid manufactured by King Industries, 25% active ingredient).
M-101 is Alonics M-101 (phenol EO modified acrylate manufactured by Toagosei Co., Ltd.).
The contents of M-220 and IBOA include those derived from a hydrogenated rosin ester resin solution, EBECRYL8411.

2. Preparation of overcoat varnish composition Linear polyester solution (number average molecular weight 10000, oxidation 0.5 mg KOH / g, hydroxyl value 18 mg KOH / g, non volatile matter 50%): 30 parts, branched polyester solution (number average molecular weight: 1000) Acid value: 4.6 mg KOH / g, hydroxyl value: 127 mg KOH / g, nonvolatile content: 30 parts, Super Beckcamine L-704-60 (Butyletherified benzoguanamine resin manufactured by DIC Corporation, nonvolatile content: 60%): 16. 7 parts, Super Beckcamine 14-570C (Butyletherified melamine resin manufactured by DIC Corporation, 60% nonvolatile content): 16.7 parts to p-toluenesulfonic acid (25% active ingredient solution in butanol): 0.5 parts After the addition of the solvent (solvonso manufactured by Exxon Mobil Solvesso # 100: butyl cellosolve = The overcoat varnish composition was prepared by diluting with 1: 1) 6.1 parts.

3. Creation of printed matter 3.1. Preparation of base plate Tin-free steel plate (plate thickness 0.18 mm) was coated with 6DF 237-38H white coating (made by DIC Graphics Inc.) at a coating weight of 130 mg / 100 cm ² by a conventional method, and heated at 180 ° C. for 10 minutes It was baked to make a base plate.

3.2. Printing Using an RI tester (manufactured by IHI Machine System Co., Ltd.), printing was performed using the active energy ray-curable printing ink composition adjusted to a film thickness of about 3 μm on the above ground surface. Subsequently to the printing, ultraviolet light was irradiated using an ultraviolet irradiation device CS-40L1 (manufactured by GS Yuasa Co., Ltd.) under the conditions of one metal halide lamp of 120 W / cm, an irradiation distance of 15 cm, and a conveyor speed of 80 m / min.

3.3. After the UV irradiation, the prepared overcoat varnish composition was coated on the entire surface at an application amount of 70 mg / 100 cm ² and baked at 190 ° C. for 5 minutes.
3.4. Processing The obtained printed matter was punched into a cylindrical shape having a diameter of 80 mm and a height of 50 mm by a conventional pressing operation.
The obtained processed product was subjected to high-pressure heat sterilization (retort) at 130 ° C. and 30 ° C.

4. Evaluation The following items were evaluated, and the results are summarized in Table 2.
4.1. Curability 3.2. The surface of the printed material obtained in the above was touched with a finger to determine the degree of moist feeling. Those with a strong feeling of stickiness were evaluated as x, those with moderate を, and those with little ○ were evaluated in three steps.

4.1. Whitening resistance The surface of the top of the processed product after high-pressure heat sterilization was observed to observe the degree of whitening. Evaluations were made in three stages, with x being a large whitening area, × being a moderate one, and ○ being a small one.
4.2. Processability The gloss change on the side of the processed product before and after high-pressure heat sterilization was observed. Evaluations were made in three stages, with a large decrease in gloss being evaluated as x, a moderate reduction as Δ, and a small reduction as ○.

  As apparent from Table 2, the printed matter printed using the active energy ray-curable printing ink composition of the present invention was excellent in processability and curability, and the occurrence of whitening was suppressed.

  The active energy ray-curable printing ink composition of the present invention can be particularly suitably used for the production of a DR can requiring high processability and retort resistance, but is not limited thereto. It is widely applicable to the surface coating application of a molded product.

Claims (11)

With pigments,
With resin,
An active energy ray curable monomer,
An acid catalyst, a including active energy ray-curable printing ink composition,
The resin comprises a hydrogenated rosin ester resin and a urethane acrylate resin,
The active energy ray curable monomer comprises a monofunctional (meth) acrylate having a cyclic structure,
The acid catalyst comprises at least one selected from the group consisting of alkyl aryl sulfonic acid, alkyl aryl sulfonate, and alkyl phosphoric acid,
The addition amount of the acid catalyst in the active energy ray-curable printing ink composition is 0.1% by mass or more and 2.0% by mass or less, and resin letterpress offset printing, waterless planographic offset printing, dampening water is used in combination An active energy ray-curable printing ink composition used for any of lithographic offset printing. The active energy ray-curable printing ink composition according to claim 1 , wherein the acid catalyst comprises at least one of alkyl aryl sulfonic acid or alkyl aryl sulfonate.   The acid catalyst comprises at least one selected from zinc salt of dodecyl benzene sulfonic acid, ammonium salt of dodecyl benzene sulfonic acid, sodium salt of dodecyl benzene sulfonic acid, xylene sulfonic acid, and p-toluene sulfonic acid. 2. Active energy ray-curable printing ink composition as described in any one of 2. The active energy ray-curable printing ink composition according to any one of claims 1 to 3, wherein the acid catalyst comprises dodecylbenzene sulfonate. The content of the monofunctional (meth) acrylate comprising the cyclic structure in the active energy ray-curable printing ink composition, more of claims 1 to 4, characterized in that at most 3 wt% to 50 wt% Active energy ray-curable printing ink composition according to any one of the preceding claims. The content of the hydrogenated rosin ester resin in the active energy ray-curable printing ink composition is 8% by mass to 30% by mass,
The content of the said urethane acrylate resin in the said active energy ray curable printing ink composition is 10 mass% or more and 30 mass% or less, The active energy ray as described in any one of the Claims 1 thru | or 5 characterized by the above-mentioned. Curing type printing ink composition. The active energy ray-curable printing ink composition according to any one of claims 1 to 6, which is for a metal can. A process of forming a printing layer using the active energy ray-curable printing ink composition according to any one of claims 1 to 7 on a substrate,
Forming an overcoat layer on the print layer using an overcoat varnish composition containing a polyester resin and an amino resin.   The printing method according to claim 8, wherein the substrate is a metal.   A printed matter characterized by being printed using the printing method according to claim 8 or 9.   A printed material comprising a printing layer formed using the active energy ray-curable printing ink composition according to any one of claims 1 to 7 on a substrate.