JP7381187B2 - Active energy ray-curable ink and method for producing printed matter - Google Patents

Description

The present invention relates to an active energy ray-curable ink that can be used for producing various printed materials.

Active energy ray-curable inks have superior curability and drying properties compared to other inks, and are therefore used for printing on various recording media such as plastic films.
As the active energy ray-curable ink, ink compositions containing a colorant, a radical polymerization initiator with a specific structure, and a radically polymerizable compound such as tetrahydrofurfuryl acrylate are known (for example, Patent Document 1) reference.).
However, because there are concerns about the effects of tetrahydrofurfuryl acrylate on the human body, such as irritation to the skin, the industry tends to avoid using inks containing tetrahydrofurfuryl acrylate.
On the other hand, inks that do not contain tetrahydrofurfuryl acrylate may cause a decrease in adhesion performance to plastic substrates.
Therefore, the industry is seeking the development of active energy ray-curable inks that do not contain the aforementioned tetrahydrofurfuryl (meth)acrylate or have a reduced content, and that have excellent adhesion performance to plastic substrates. The reality is that although it is sought after, it has not yet been found.

Japanese Patent Application Publication No. 2012-201815

The problem to be solved by the present invention is that even if it does not contain tetrahydrofurfuryl (meth)acrylate or the like, or its content is small, the adhesion performance to various base materials including plastic base materials can be improved. An object of the present invention is to provide an excellent active energy ray curable ink.

（一般式（１）中のＲ^１、Ｒ^２及びＲ^３はそれぞれ独立して水素原子またはアルキル基を表し、Ｘ^１は単結合またはアルキレン基を表す。） The present inventor solved the above problem with an active energy ray-curable ink characterized by containing a polymerizable compound (A) containing a compound (a) represented by the following general formula (1).

(R ¹ , R ² and R ³ in general formula (1) each independently represent a hydrogen atom or an alkyl group, and X ¹ represents a single bond or an alkylene group.)

Since the active energy ray-curable ink of the present invention has excellent adhesion performance to tetrahydrofurfuryl (meth)acrylate, it does not contain, for example, a process for producing printed matter using an inkjet recording device or the like, or its content is Even if the amount is small, it can be suitably used in situations such as plastic substrates.

The active energy ray-curable ink of the present invention is characterized by containing a polymerizable compound (A) containing a compound (a) represented by the following general formula (1).

(R ¹ , R ² and R ³ in general formula (1) each independently represent a hydrogen atom or an alkyl group, and X ¹ represents a single bond or an alkylene group.)

Examples of the alkyl group include a methyl group and an ethyl group. Further, specific examples of the X ¹ include a methylene group and an ethylene group.
As the compound (a) represented by the above general formula (1), it is preferable to use a compound in which R ¹ , R ² , and R ³ in the above general formula (1) are hydrogen atoms, since it has good adhesion to the plastic substrate. This is preferable in terms of its effectiveness.
Specifically, it is preferable to use cyclic trimethylolpropane formal acrylate as the compound (a) represented by the general formula (1).

The compound (a) is preferably contained in a range of 5% by mass to 40% by mass, and preferably contained in a range of 8% by mass to 30% by mass, based on the entire polymerizable compound (A). This is preferable for obtaining an active energy ray-curable ink that has excellent adhesion to various substrates including plastic substrates.

By using a compound containing the compound (a) as the polymerizable compound (A), the compound (c) having the structure represented by the chemical formula (2) can be included in the polymerizable compound (A). Even if the content ratio of the compound (c) to the entire polymerizable compound (A) is preferably 0% by mass to 0.2% by mass, various base materials including plastic base materials It is possible to obtain an active energy ray-curable ink with excellent adhesion to.

Examples of the compound (c) having the structure represented by the chemical formula (2) include tetrahydrofurfuryl (meth)acrylate and tetrahydrofurfuryl alcohol, and the content thereof is based on the entire polymerizable compound (A). 0% to 0.2% by weight, preferably 0% to 0.1% by weight, more preferably 0% to 0.05% by weight, particularly preferably 0% by weight. preferable.

As the polymerizable compound (A), in addition to the compound (a), if necessary, a compound containing a compound (b) having a polymerizable unsaturated double bond other than the compound (a) is used. It is preferable.
It is preferable to use a compound (b) having 1 to 6 polymerizable unsaturated double bonds, and it is preferable to use a compound having 1 to 3 polymerizable unsaturated double bonds in order to improve flexibility and the plastic group. This is more preferable in order to obtain an ink that has even better adhesion to materials.
It is preferable to use the compound (b) in an amount of 80% to 95% by mass based on the entire polymerizable compound (A) in terms of flexibility and adhesion to the plastic substrate etc. Preferable for obtaining excellent ink.

As the compound (b), for example, a compound having a heterocyclic structure such as tetrahydrofurfuryl (meth)acrylate can be used, but a compound having a heterocyclic structure other than the chemical formula (2) (b- 1), a compound (b-2) having an aliphatic cyclic structure, etc. are preferably used.
As the compound (b-1), for example, caprolactone-modified tetrahydrofurfuryl acrylate, acryloylmorpholine, N-vinyl-2-caprolactam, N-vinylpyrrolidone, N-acryloyloxyethylhexahydrophthalimide, etc. can be used. Among these, N-vinyl-2-caprolactam is preferably used as the compound (b-1) because it has active energy ray curability and excellent adhesion to various substrates including plastic substrates. Preferable for obtaining ink.

In order to further improve the long-term storage stability of the ink of the present invention, the compound (b-1) may be present in an amount of 1% by mass to 15% by mass based on the total amount of the polymerizable compound (A). It is preferable to use it, and it is more preferable to use it in a range of 5% by mass to 15% by mass in order to obtain an ink having excellent adhesion to various substrates including plastic substrates.

Further, the compound (b-2) can be used for producing printed matter having a level of chemical resistance that does not cause peeling of the coating even when it comes into contact with chemicals such as alcohol, and Used in combination with the above compound (a), the above compound (b-1), etc. to obtain an active energy ray-curable ink with even better adhesion to various base materials including plastic base materials. It is preferable.
Examples of the compound (b-2) include tricyclodecanedimethanol di(meth)acrylate, adamantyl(meth)acrylate, cyclohexanedimethanol mono(meth)acrylate, cyclohexanedimethanol di(meth)acrylate, trimethylcyclohexyl(meth)acrylate, ) acrylate, isobornyl (meth)acrylate, t-butylcyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, and dicyclopentenyloxyethyl (meth)acrylate, among which isobornyl (meth)acrylate can be used. ) It is more preferable to use acrylate in order to obtain an ink that can be used to produce printed matter having the printed coating film with excellent chemical resistance.
The compound (b-2) is preferably used in a range of 5% by mass to 24% by mass, and preferably in a range of 5% by mass to 20% by mass, based on the entire polymerizable compound (A). , is more preferable in order to obtain an ink that can be used for producing printed matter having a printed coating film with better chemical resistance.

The active energy ray-curable ink of the present invention may contain a photopolymerization initiator in addition to the polymerizable compound (A).
Examples of the photopolymerization initiator include benzoin isobutyl ether, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, benzyl, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 6-trimethylbenzoyldiphenylphosphine oxide, 2- Benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, 1-hydroxycyclohexylphenyl Ketones, benzoin ethyl ether, benzyl dimethyl ketal, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one and 2 -Methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, benzophenone, 4-phenylbenzophenone, isophthalphenone, 4-benzoyl-4'-methyl-diphenyl sulfide, etc. can be used. .
Among the above-mentioned photopolymerization initiators, it is preferable to use an acylphosphine oxide photopolymerization initiator.
In addition, when a UV-LED light source is used as the active energy ray light source, the photopolymerization initiator is 2-benzyl-2-dimethylamino-1 corresponding to the wavelength of light emitted from the UV-LED light source. -(4-morpholinophenyl)-butan-1-one, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-(4-morpholinophenyl)-butan-1-one) , bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, etc. are preferably used. .

Further, the photopolymerization initiator is preferably used in combination with a sensitizer. Examples of the sensitizer include trimethylamine, methyldimethanolamine, triethanolamine, p-diethylaminoacetophenone, ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, N,N-dimethylbenzylamine, and , 4'-bis(diethylamino)benzophenone, etc., which have no reactivity with the polymerizable compound (A) can be used.

The active energy ray-curable ink of the present invention may contain a coloring agent, if necessary, in addition to the polymerizable compound (A) and a photopolymerization initiator.
As the colorant, for example, a pigment or a dye can be used. Examples of the pigments include phthalocyanine pigments used in cyan inks, quinacridone pigments used in magenta inks, azo pigments used in yellow inks, carbon black used in black inks, and white pigments that can be used in white inks. Examples include pigments.

Examples of the phthalocyanine pigment used in the cyan ink include C.I. I. Pigment Blue 1, 2, 3, 15:3, 15:4, 16:6, 16, 17:1, 75, 79, and the like.

Examples of quinacridone pigments used in magenta ink include C.I. I. Pigment Red 122, C. I. Pigment Red 202, C. I. Pigment Red 209, C. I. Examples include Pigment Violet 19.

Examples of azo pigments used in yellow ink include C.I. I. Monoazo and disazo pigments such as Pigment Yellow 120, 151, 154, 175, 180, 181, 1, 65, 73, 74, 116, 12, 13, 17, 81, 83, 150, 155, 214, 128. included.

As the carbon black used for black ink, Mitsubishi Chemical Corporation's No. 2300, No. 900, MCF88, No. 33, No. 40, No. 45, No. 52, MA7, MA8, MA100, No. 2200B etc. are Columbia's Raven5750, 5250, 5000, 3500, 1255, 700 etc. are Cabot's Regal400R, 330R, 660R, Mogul L, 700, Monarch800, 880, Degussa's Color Black FW1, Degussa FW2, Degussa FW2V, Degussa FW18, Degussa FW200, ColorBlack S150, Degussa S160, Degussa S170, Printex 35, Degussa Examples include Special Black U, Special Black V, Special Black 140U, Special Black 6, Special Black 5, Special Black 4A, Special Black 4, etc.

The white pigment that can be used in the white ink is not particularly limited, and any known inorganic white pigment can be used. Examples of the inorganic white pigment include sulfates or carbonates of alkaline earth metals, silicas such as finely divided silicic acid and synthetic silicates, calcium silicate, alumina, alumina hydrate, titanium oxide, zinc oxide, and talc. , clay, etc. As the inorganic white pigment, it is also possible to use the above-mentioned silicas whose surfaces have been surface-treated by various surface treatment methods.

The average particle size of the pigment is preferably in the range of 10 to 300 nm, more preferably 50 to 200 nm.
In order to obtain sufficient image density and light resistance of the printed image, the pigment is preferably contained in a range of 1 to 20% by mass, and preferably in a range of 1 to 10% by mass, based on the total amount of each ink. is more preferred, and most preferably in a range of 1 to 5% by weight. Further, it is preferable that the pigment concentration of magenta ink is higher than that of other color inks. Specifically, the pigment concentration is preferably 1.2 times or more, more preferably 1.2 to 4 times, that of other color inks.

The average particle size of the titanium oxide is preferably 100 to 500 nm, and in order to obtain an ink with even better ejection stability and high color development of printed images, it is preferable to use a particle size of 150 to 400 nm. It is more preferable to use particles having an average particle size of .

The pigment may be used in combination with a pigment dispersant, a pigment derivative (synergist), etc. for the purpose of increasing the dispersion stability with respect to the polymerizable compound (A) and the like.
Examples of the pigment dispersant include Ajisper PB821, PB822, and PB817 manufactured by Ajinomoto Fine Techno, Solsparz 24000GR, 32000, 33000, and 39000 manufactured by Lubrizol, and Disparon DA-703-50 and DA- manufactured by Kusumoto Kasei Co., Ltd. 705, DA-725, etc. can be used.
The amount of the pigment dispersant used is preferably in the range of 10 to 100% by mass based on the pigment, and in order to obtain an ink with even better ejection stability and pigment dispersibility, it is 20 to 60% by mass. It is more preferable to use one within the range of . Examples of the pigment derivatives include sulfonic acid derivatives of pigments.

In addition to the above-mentioned components, the active energy ray-curable ink of the present invention may optionally contain polymerization inhibitors such as hydroquinone, methoquinone, di-t-butylhydroquinone, P-methoxyphenol, butylated hydroxytoluene, and nitrosamine salts. can be used. The polymerization inhibitor can be used in an amount of 0.01% by mass to 2% by mass based on the total amount of the ink of the present invention.

Examples of the active energy ray-curable ink of the present invention include trimethylamine, methyldimethanolamine, triethanolamine, p-diethylaminoacetophenone, ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, N,N- Those containing sensitizers such as dimethylbenzylamine and 4,4'-bis(diethylamino)benzophenone can be used.

The active energy ray-curable ink of the present invention may contain non-reactive resins such as acrylic resins, epoxy resins, terpene phenol resins, and rosin esters in order to further improve the adhesion to substrates such as plastic substrates. You can use the one that contains it.

As the active energy ray-curable ink of the present invention, it is preferable to use one whose viscosity at 25°C is in the range of 3 mPa·sec to 30 mPa·sec, and preferably in the range of 5 mPa·sec to 20 mPa·sec. This is more preferable in terms of achieving the effect of stabilizing inkjet discharge.

The active energy ray-curable ink of the present invention can be prepared by dispersing the pigment in a mixture of the polymerizable compound (A) and optionally a pigment, a pigment dispersant, and a resin using a conventional dispersion machine such as a bead mill. After that, a photopolymerization initiator is added, and if necessary, additives such as a polymerization inhibitor, sensitizer, and surface tension regulator are added, and the mixture is stirred and dissolved.
The active energy ray-curable ink is prepared in advance by producing a high-concentration pigment dispersion (mill base) containing a pigment, a pigment dispersant, a resin, etc. using a normal dispersion machine such as a bead mill, and then adding a photopolymerization initiator. It can also be produced by supplying, stirring, and mixing the polymerizable compound (A), additives, and the like.

As the dispersing machine, in addition to a bead mill, various known and commonly used dispersing machines can be used, such as an ultrasonic homogenizer, a high-pressure homogenizer, a paint shaker, a ball mill, a roll mill, a sand mill, a sand grinder, a Dyno mill, a Dispermat, an SC mill, and a nanomizer. be able to.

The active energy ray-curable ink of the present invention is cured by irradiation with active energy rays, preferably ultraviolet light or the like. Examples of light sources such as ultraviolet rays include those normally used for active energy ray-curable inkjet recording inks, such as metal halide lamps, xenon lamps, carbon arc lamps, chemical lamps, low-pressure mercury lamps, high-pressure mercury lamps, and UV-LED lamps. can be used.

The active energy ray-curable ink of the present invention can be suitably used for printing exclusively by an inkjet recording method using an inkjet recording device.

As the inkjet recording method, any conventionally known method can be used. Examples include a method of ejecting droplets using the vibration of a piezoelectric element (a recording method using an inkjet head that forms ink droplets by mechanical deformation of an electrostrictive element) and a method of using thermal energy.
A printed matter can be produced by ejecting the active energy ray-curable ink onto a base material, which is a recording medium, using an inkjet recording device, and curing the ink by irradiating it with active energy rays. Examples of the printed matter include advertisements, billboards, information boards, and promotional prints.

The active energy ray-curable ink of the present invention has excellent adhesion to various substrates that are recording media, so it can be easily printed on the surface of substrates that have curved surfaces or irregular shapes. I can do it.
As the base material, for example, a plastic base material can be used. Specifically, the plastic base material includes ABS (acrylonitrile butadiene styrene) resin, PVC (polyvinyl chloride)/ABS resin, and PA (polyamide)/ABS resin, which are used as general-purpose injection molding plastics. , PC (polycarbonate)/ABS resin, ABS-based polymer alloys such as PBT (polybutylene terephthalate)/ABS, AAS (acrylonitrile/acrylic rubber/styrene) resin, AS (acrylonitrile/styrene) resin, AES (acrylonitrile/ethylene rubber) Examples include base materials made of styrene) resin, MS ((meth)acrylate styrene) resin, PC (polycarbonate) resin, acrylic resin, methacrylic resin, PP (polypropylene) resin, etc.

Further, as the plastic base material, it is also possible to use, for example, a thermoplastic resin film used for packaging materials.
Examples of the thermoplastic resin film include those generally used for food packaging, such as polyethylene terephthalate (PET) film, polystyrene film, polyamide film, polyacrylonitrile film, and polyethylene film. Polyolefin films such as (LLDPE: low density polyethylene film, HDPE: high density polyethylene film) and polypropylene film (CPP: unoriented polypropylene film, OPP: biaxially oriented polypropylene film), polyvinyl alcohol film, ethylene-vinyl alcohol copolymer Examples include films. As the thermoplastic resin film, one that has been subjected to stretching treatment such as uniaxial stretching or biaxial stretching, or one that has been subjected to flame treatment, corona discharge treatment, etc. on the surface can also be used.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

[Example 1]
[Example of preparation of cyan pigment dispersion]
Preparation example of cyan pigment dispersion (1) Fastgen Blue TGR-G (manufactured by DIC Corporation, phthalocyanine pigment C.I. Pigment Blue 15:4) 10 parts by mass, Solsparz 32000 (manufactured by Lubrizol Corporation, polymeric pigment dispersant) 4.5 parts by mass and 85.5 parts by mass of light acrylate POA (phenoxyethyl acrylate manufactured by Kyoeisha Chemical Co., Ltd.) were mixed, stirred for 1 hour with a stirrer, and then treated with a bead mill for 2 hours to obtain a cyan pigment dispersion ( 1) was obtained.

[Ink preparation example]
According to the blending ratio shown in Table 1, MIRAMER M3130 (ethylene oxide (EO) modified trimethylolpropane triacrylate manufactured by MIWON), MIRAMER M240 (ethylene oxide (EO) modified bisphenol A diacrylate manufactured by MIWON), and Viscoat were added to the container. #200 (cyclic trimethylolpropane formal acrylate manufactured by Osaka Organic Chemical Industry Co., Ltd.), IBXA (isobornyl acrylate manufactured by Osaka Organic Chemical Industry Co., Ltd.), V-CAP (N-vinyl-2-caprolactam manufactured by ISP), Light acrylate POA (phenoxyethyl acrylate manufactured by Kyoeisha Chemical Co., Ltd.) and KF-54 (polysiloxane manufactured by Shin-Etsu Chemical Co., Ltd.) were added and mixed, followed by Irgacure 819 (bis (2,4,6-trimethylbenzoyl manufactured by BASF)). -phenylphosphine oxide), Irgacure. TPO (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide manufactured by BASF) and Kayacure DETX-S (diethylthioxanthone manufactured by Nippon Kayaku Co., Ltd.) were added and dissolved by mixing at a temperature of 60° C. for 30 minutes.
Next, the cyan pigment dispersion (1) was added and stirred and mixed for 10 minutes to obtain cyan ink (C1).

[Example 2]
The amount of Viscoat #200 (manufactured by Osaka Organic Chemical Industry Co., Ltd., cyclic trimethylolpropane formal acrylate) was changed from 20 parts by mass to 27 parts by mass, and the amount of POA (phenoxyethyl acrylate, manufactured by Kyoeisha Chemical Co., Ltd.) was changed from 20 parts by mass to 27 parts by mass. Cyan ink (C2) was obtained in the same manner as in Example 1, except that the amount was changed from 16.3 parts by mass to 9.3 parts by mass.

[Example 3]
The amount of Viscoat #200 (manufactured by Osaka Organic Chemical Industry Co., Ltd., cyclic trimethylolpropane formal acrylate) was changed from 20 parts by mass to 34 parts by mass, and the amount of POA (phenoxyethyl acrylate, manufactured by Kyoeisha Chemical Co., Ltd.) was changed from 20 parts by mass to 34 parts by mass. Cyan ink (C3) was obtained in the same manner as in Example 1, except that the amount was changed from 16.3 parts by mass to 2.3 parts by mass.

[Example 4]
The amount of Viscoat #200 (manufactured by Osaka Organic Chemical Industry Co., Ltd., cyclic trimethylolpropane formal acrylate) was changed from 20 parts by mass to 27 parts by mass, and V-CAP (N-vinyl-2-caprolactam, manufactured by ISP) was added. Cyan ink (C4) was obtained in the same manner as in Example 1, except that the amount used was changed from 12 parts by mass to 5 parts by mass.

[Example 5]
The amount of Viscoat #200 (manufactured by Osaka Organic Chemical Industry Co., Ltd., cyclic trimethylolpropane formal acrylate) was changed from 20 parts by mass to 27 parts by mass, and the amount of POA (phenoxyethyl acrylate, manufactured by Kyoeisha Chemical Co., Ltd.) was changed from 20 parts by mass to 27 parts by mass. Example 1 except that 16.3 parts by mass was changed to 19.3 parts by mass, and the amount of IBXA (isobornyl acrylate manufactured by Osaka Organic Chemical Industry Co., Ltd.) was changed from 15 parts by mass to 5 parts by mass. Cyan ink (C5) was obtained in the same manner as above.

[Example 6]
The amount of Viscoat #200 (manufactured by Osaka Organic Chemical Industry Co., Ltd., cyclic trimethylolpropane formal acrylate) was changed from 20 parts by mass to 27 parts by mass, and the amount of POA (phenoxyethyl acrylate, manufactured by Kyoeisha Chemical Co., Ltd.) was changed from 20 parts by mass to 27 parts by mass. Example 1 except that 16.3 parts by mass was changed to 3.3 parts by mass, and the amount of IBXA (isobornyl acrylate manufactured by Osaka Organic Chemical Industry Co., Ltd.) was changed from 15 parts by mass to 21 parts by mass. Cyan ink (C6) was obtained in the same manner as above.

[Comparative example 1]
The amount of Viscoat #200 (manufactured by Osaka Organic Chemical Industry Co., Ltd., cyclic trimethylolpropane formal acrylate) was changed from 20 parts by mass to 0 parts by mass, and the amount of POA (phenoxyethyl acrylate, manufactured by Kyoeisha Chemical Co., Ltd.) was changed. Cyan ink (C' 1) was obtained.

[Comparative example 2]
The amount of POA (phenoxyethyl acrylate manufactured by Kyoeisha Chemical Co., Ltd.) was changed from 9.3 parts by mass to 36.1 parts by mass, and the amount of tetrahydrofurfuryl acrylate was changed from 27 parts by mass to 0.2 parts by mass. Cyan ink (C'2) was obtained in the same manner as in Comparative Example 1 except for the above.

[Comparative example 3]
Other than changing the amount of POA (phenoxyethyl acrylate manufactured by Kyoeisha Chemical Co., Ltd.) from 9.3 parts by mass to 36.3 parts by mass, and changing the amount of tetrahydrofurfuryl acrylate from 27 parts by mass to 0 parts by mass. A cyan ink (C'3) was obtained in the same manner as in Comparative Example 1.
[Comparative example 4]
The amount of POA (phenoxyethyl acrylate manufactured by Kyoeisha Chemical Co., Ltd.) was changed from 9.3 parts by mass to 30.3 parts by mass, the amount of tetrahydrofurfuryl acrylate was changed from 27 parts by mass to 0 parts by mass, and IBXA Cyan ink (C'4) was obtained in the same manner as in Comparative Example 1, except that the amount of isobornyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.) was changed from 15 parts by mass to 21 parts by mass.

[Substrate adhesion]
The active energy ray-curable inkjet recording ink was applied to a polycarbonate plate (manufactured by Asahi Glass Co., Ltd., Lexan, thickness 1 mm, PC) and a vinyl chloride sheet (vinyl chloride sheet, PVC, manufactured by DIC Corporation) using a spin coater. The film was coated to a thickness of 10 μm using an LED irradiation device (emission wavelength: 385 nm, peak intensity: 500 mW/cm ² ) manufactured by Hamamatsu Photonics Co., Ltd., equipped with a stage moving device, until the tack on the surface of the film disappeared. Irradiated (until it became tack-free).
After making incisions in the obtained cured coating film in the form of 25 squares of 5×5 at 2 mm intervals with a utility knife, cellophane tape manufactured by Nichiban Co., Ltd. was applied and rubbed with a nail about 10 times. The tape was vigorously peeled off at a peeling speed of approximately 1 cm/sec, and the number of squares remaining in the coating film was confirmed.

Evaluation criteria ○: The number of squares of the coating film remaining on the surface of the polycarbonate board or vinyl chloride sheet is 20 or more △: The number of squares of the coating film remaining on the surface of the polycarbonate board or vinyl chloride sheet is 15 or more and less than 20 ×: Polycarbonate board Or the number of squares of the coating film remaining on the surface of the vinyl chloride sheet is less than 15

[Solvent resistance]
The active energy ray-curable inkjet recording ink was applied to a polycarbonate plate (manufactured by Asahi Glass Co., Ltd., Lexan, thickness 1 mm, PC) to a thickness of 10 μm using a spin coater, and then equipped with a stage moving device. Using an LED irradiation device manufactured by Hamamatsu Photonics Co., Ltd. (emission wavelength: 385 nm, peak intensity: 500 mW/cm ² ), irradiation was performed until the surface of the coating film became tack-free.
A cotton swab soaked in a mixture of ethanol and water (ethanol content: 70% by mass) was placed on the obtained cured coating film and rubbed 10 times from side to side in a width of about 2 cm. Those with no scratch marks on the coating surface were evaluated as "○", and those with scratch marks were evaluated as "x".

[Skin irritation]
Evaluation was made according to the degree of skin irritation caused by tetrahydrofurfuryl acrylate. "×" indicates that the skin irritation caused by tetrahydrofurfuryl acrylate is considered to be high, "△" indicates that the skin irritation is considered to be low, and it is considered that there is no skin irritation caused by tetrahydrofurfuryl acrylate. The item was evaluated as "○".

The abbreviations listed in Tables 1 and 2 refer to the following compounds.
M3130: Ethylene oxide (EO) modified trimethylolpropane triacrylate manufactured by MIWON M240: Ethylene oxide (EO) modified bisphenol A diacrylate V200 manufactured by MIWON: Viscoat #200, cyclic trimethylolpropane formal manufactured by Osaka Organic Chemical Industry Co., Ltd. acrylate)
IBXA: Isobornyl acrylate V-CAP: Manufactured by ISP N-vinyl-2-caprolactam POA: Manufactured by Kyoeisha Chemical Co., Ltd. Phenoxyethyl acrylate THFA: Tetrahydrofurfuryl acrylate KF-54: Manufactured by Shin-Etsu Chemical Co., Ltd. Polysiloxane Irgacure 819: Bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide IrgacureTPO manufactured by BASF: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide/Kayacure DETX-S manufactured by BASF: Diethylthioxanthone [manufactured by Nippon Kayaku Co., Ltd.] Irgacure 819/Irgacure TPO]: Weight ratio of bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide to 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide

Claims (4)

Contains a polymerizable compound (A) containing a compound (a) represented by the following general formula (1) and a compound (b) having a polymerizable unsaturated double bond other than the compound (a),
The compound (b) contains a compound (b-1) having a heterocyclic structure other than the following chemical formula (2) and a compound (b-2) having an aliphatic cyclic structure,
The compound (a) is contained in an amount of 30.2 % by mass to 40% by mass based on the entire polymerizable compound (A),
The compound (b-1) is contained in an amount of 1% to 15% by mass based on the entire polymerizable compound (A),
The compound (b-2) is contained in an amount of 1% to 24% by mass based on the entire polymerizable compound (A) ,
An active energy ray-curable ink characterized by not containing a compound having a structure represented by the following chemical formula (2) .

(R ¹ , R ² and R ³ in general formula (1) each independently represent a hydrogen atom or an alkyl group, and X ¹ represents a single bond or an alkylene group.)

The active energy ray-curable ink according to claim 1, which has a viscosity at 25° C. in the range of 5 to 30 mPa·sec. The active energy ray-curable ink according to claim 1 or 2 , further comprising an acylphosphine oxide photopolymerization initiator. 3. A method for producing printed matter, comprising discharging the active energy ray-curable ink according to claim 2 onto a recording medium using an inkjet recording device, and curing the ink by irradiating the ink with active energy rays.