JP2021161182A - Ink composition and method of forming decorative body - Google Patents

Abstract

To provide an active energy ray-curable ink composition capable of suppressing bleeding out of an ultraviolet absorber or a radical scavenger and imparting excellent long-term weather resistance to a decorative body.SOLUTION: An active energy ray-curable ink composition contains (A) a polymerizable compound, (B) a photopolymerization initiator, (C) an ultraviolet absorber and/or (D) a radical scavenger. The polymerizable compound (A) contains a monofunctional polymerizable compound and a polyfunctional polymerizable compound. The monofunctional polymerizable compound includes at least one monofunctional polymerizable compound (a) selected from the group consisting of a monofunctional polymerizable compound (a-1) having a specific molecular weight and melting point, a monofunctional polymerizable compound (a-2) having a specific molecular weight, melting point and viscosity, and a monofunctional polymerizable compound (a-3) being other than the (a-1) and (a-2) and having an amide group and a cyclic structure.SELECTED DRAWING: None

Description

The present invention relates to an active energy ray-curable ink composition and a method for forming a decorative body using the ink composition, and in particular, suppresses bleed-out of an ultraviolet absorber or a radical scavenger, and is excellent in the decorative body. It relates to an active energy ray-curable ink composition capable of imparting long-term weather resistance.

In recent years, printed matter having various designs has become widespread due to improvements in printing technology such as inkjet printers. In particular, photocurable inks that are cured by active energy rays or the like provide images that dry quickly and have less bleeding when decorating non-absorbent or non-absorbent media that do not easily absorb ink such as plastics and vinyl chloride sheets. Since it can be used, the range of usage is expanding. However, when these printed matter is installed outdoors, there is a problem that the ink decorative portion is liable to be deteriorated by light, the printed matter is discolored, and the appearance is deteriorated with time.

Japanese Patent Application Laid-Open No. 2011-47152 (Patent Document 1) reduces the weather resistance of building boards patterned with yellow pigment, magenta pigment, and cyan pigment by making the color difference before and after discoloration and fading substantially the same. Describes inventions that make it difficult to understand. This is an effective method when an inorganic pigment having excellent weather resistance is used, but the effect is insufficient in terms of a vivid and easily fading design such as an organic pigment or a dye.

Japanese Unexamined Patent Publication No. 2012-214603 (Patent Document 2) describes an invention relating to an active energy ray-curable inkjet ink composition having excellent weather resistance using a pigment ink containing a light stabilizer. The coexistence of pigments has a problem of limiting the effect of the light stabilizer.

Japanese Unexamined Patent Publication No. 2019-30998 (Patent Document 3) describes the invention of a decorative sheet containing an ultraviolet absorber and a light stabilizer in a top coat layer covering a decorative portion. The decorative sheet described in Patent Document 3 is manufactured by dry laminating, extrusion laminating, or the like. In this way, there is a method of protecting the decorative part by a method such as laminating, but it is necessary to separately protect the decorative layer with a laminating machine or the like, and a transparent laminating material is provided with an ultraviolet absorber and light stabilization. In order to dissolve and process the agent and to exhibit the effect of maintaining the weather resistance, the material selectivity is large and there is a difficult problem.

In response to these problems, Japanese Patent Application Laid-Open No. 2019-81867 (Patent Document 4) proposes to improve the weather resistance by separately preparing a clear ink, but the improvement in the weather resistance of the clear ink is improved. There was room. As a method for improving weather resistance, for example, as described in Japanese Patent No. 6094771 (Patent Document 5) and Japanese Patent Application Laid-Open No. 2011-148918 (Patent Document 6), an ultraviolet absorber and a radical scavenger are blended. The method is known. However, since these tend to bleed from the printed film over time, the sustainability of the effects of the ultraviolet absorber and the radical scavenger has become an issue. In Patent Document 6, the selection of the ultraviolet absorber and the adjustment of the molecular weight of the radical scavenger are made. Is trying to solve this problem.

Japanese Unexamined Patent Publication No. 2011-47152 Japanese Unexamined Patent Publication No. 2012-214603 JP-A-2019-30998 JP-A-2019-81867 Japanese Patent No. 6094771 Japanese Unexamined Patent Publication No. 2011-148918

Therefore, an object of the present invention is an active energy ray capable of solving the above-mentioned problems of the prior art, suppressing bleed-out of an ultraviolet absorber or a radical scavenger, and imparting excellent long-term weather resistance to a decorative body. The purpose is to provide a curable ink composition. Another object of the present invention is to provide a method for forming a decorative body using such an ink composition.

As a result of diligent studies to achieve the above object, the present inventor has added an active energy ray-curable ink composition containing an ultraviolet absorber and a radical scavenger with a molecular weight of 250 g / mol or less and a melting point of 25 ° C. or more. The monofunctional polymerizable compound (a-1), which has a molecular weight of 250 g / mol or less, a melting point of less than 25 ° C., and a viscosity at 25 ° C. of 20 mPa · s or more (a-2). ), Or a monofunctional polymerizable compound other than these monofunctional polymerizable compounds (a-1) and (a-2), which has a cyclic structure with an amide group (a-3). It has been found that when used together with a functionally polymerizable compound, bleed-out of an ultraviolet absorber and a radical scavenger can be suppressed and a surface protective layer having excellent long-term weather resistance can be formed, and the present invention has been completed.

In order to prevent bleeding out of UV absorbers and radical scavengers, a method is known in which the polymers constituting the film are crosslinked to form a dense film, but in this case, cracks due to internal stress occur over time. May occur. On the other hand, when a monofunctional polymerizable compound having a molecular weight and a melting point within the specified ranges is used, the occurrence of cracks can be suppressed. It is considered that this is because the cohesive force of the monofunctional polymerizable compound forms a pseudo-dense film, and the bleed-out of the ultraviolet absorber and the radical scavenger can be prevented without cross-linking.

That is, the ink composition of the present invention is an active energy ray-curable type containing (A) a polymerizable compound, (B) a photopolymerization initiator, (C) an ultraviolet absorber and / or (D) a radical trapping agent. In the ink composition, the polymerizable compound (A) contains a monofunctional polymerizable compound and a polyfunctional polymerizable compound, and the monofunctional polymerizable compound has a molecular weight of 250 g / mol or less and a melting point of 25 ° C. The monofunctional polymerizable compound (a-1) described above, the monofunctional polymerizable compound (a-1) having a molecular weight of 250 g / mol or less, a melting point of less than 25 ° C., and a viscosity at 25 ° C. of 20 mPa · s or more. 2), and a monofunctional polymerizable compound other than the monofunctional polymerizable compound (a-1) and the monofunctional polymerizable compound (a-2), which has an amide group and a cyclic structure. It is characterized by containing at least one monofunctional polymerizable compound (a) selected from the group consisting of (a-3).

In a preferred example of the ink composition of the present invention, the content of the monofunctional polymerizable compound (a) in the ink composition is 1% by mass or more and 25% by mass or less.

In another preferred example of the ink composition of the present invention, the amount of the monofunctional polymerizable compound in the ink composition is in the range of 70 to 90% by mass.

In another preferred example of the ink composition of the present invention, the polyfunctional polymerizable compound contains a polyfunctional polymerizable oligomer, and the amount of the polyfunctional polymerizable oligomer in the ink composition is within the range of 30% by mass or less. Is.

In another preferred example of the ink composition of the present invention, the ink composition contains 70 to 90% by mass of a monofunctional polymerizable compound and 3 to 20% by mass of a polyfunctional polymerizable oligomer.

In another preferred example of the ink composition of the present invention, the value B of the ultraviolet absorber (C) obtained by the following formula (1) is 100 or more.
Molecular weight of UV absorber (g / mol) / | SP value of UV absorber-Average SP value of polymerizable compound | = B ... Formula (1)

In another preferred example of the ink composition of the present invention, the (C) UV absorber contains at least two UV absorbers.

In another preferred example of the ink composition of the present invention, the photopolymerization initiator (B) comprises an acylphosphine oxide-based initiator.

In another preferred example of the ink composition of the present invention, the ink composition contains (D) a radical scavenger in the range of 0.5 to 5% by mass.

In another preferred example of the ink composition of the present invention, the ink composition is a clear ink having a light transmittance of 80% or more in the wavelength range of 380 to 800 nm when a film having a thickness of 30 μm is formed. ..

In another preferred example of the ink composition of the present invention, the ink composition protects the surface of a colored layer formed by at least one of a paint, a printing ink, an inkjet ink, and a powder toner. Clear ink.

Further, the method for forming a decorative body of the present invention is characterized in that inkjet printing is performed on the surface of a colored layer formed on a base material with the ink composition according to any one of claims 1 to 11. ..

According to the ink composition of the present invention, there is provided an active energy ray-curable ink composition capable of suppressing bleed-out of an ultraviolet absorber or a radical scavenger and imparting excellent long-term weather resistance to a decorative body. can do. Further, according to the method for forming a decorative body of the present invention, it is possible to provide a method for forming a decorative body using such an ink composition.

The ink composition of the present invention will be described in detail below. The ink composition of the present invention is an active energy ray-curable ink composition, which comprises (A) a polymerizable compound, (B) a photopolymerization initiator, (C) an ultraviolet absorber and / or (D) a radical. Including with a scavenger.

In the present specification, the active energy ray-curable ink composition means an ink composition that can be cured by irradiation with active energy rays such as ultraviolet rays, visible rays, and electron beams. Further, in the present specification, the ink composition for inkjet means an ink composition for use in printing by an inkjet printer (also referred to as inkjet printing).

In the present specification, printing means applying ink on an object by a printing means, and is not limited to those intended to color the object or draw characters, images, etc., and is not limited to the surface of the object. It is also included that the purpose is to coat the object or to perform a surface treatment on the object.

The polymerizable compound (A) used in the ink composition of the present invention is a carbon-carbon double bond constituting a functional group (for example, an acryloyl group, a methacryloyl group, a vinyl group or an allyl group) that exhibits reactivity when irradiated with active energy rays. It is a compound that causes a polymerization reaction via a polymerizable unsaturated group such as The polymerizable compound may be used alone or in combination of two or more. The amount of the (A) polymerizable compound in the ink composition of the present invention is preferably 70 to 95% by mass.

In the ink composition of the present invention, the polymerizable compound (A) includes a monofunctional polymerizable compound and a polyfunctional polymerizable compound. Here, as the monofunctional polymerizable compound, a monofunctional polymerizable monomer having one functional group exhibiting reactivity when irradiated with active energy rays (for example, a monofunctional polymerizable monomer having one polymerizable unsaturated group) or an activity Examples thereof include a monofunctional polymerizable oligomer having one functional group exhibiting reactivity when irradiated with energy rays (for example, a monofunctional polymerizable oligomer having one polymerizable unsaturated group). Examples of the polyfunctional polymerizable compound include a polyfunctional polymerizable monomer having two or more functional groups exhibiting reactivity when irradiated with active energy rays (for example, a polyfunctional polymerizable monomer having two or more polymerizable unsaturated groups) and an activity. Examples thereof include a polyfunctional polymerizable oligomer having two or more functional groups exhibiting reactivity when irradiated with energy rays (for example, a polyfunctional polymerizable oligomer having two or more polymerizable unsaturated groups).

In the ink composition of the present invention, the amount of the monofunctional polymerizable compound, particularly the monofunctional polymerizable monomer, is preferably 70 to 90% by mass. In the ink composition of the present invention, the amount of the polyfunctional polymerizable monomer is, for example, 30% by mass or less, preferably 20% by mass or less. In the ink composition of the present invention, the amount of the polymerizable oligomer is preferably 3 to 30% by mass from the viewpoint of shrinkage stress and curing rate. Among them, the polyfunctional polymerizable oligomer is preferably contained in an amount of 3 to 20% by mass, particularly 5 to 15% by mass, and from the viewpoint of improving the weather resistance of the coating film, it is more preferable to contain a trifunctional or higher functional polymerizable oligomer. preferable.

Specific examples of the monofunctional polymerizable monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxykipropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6. -Hydroxyhexyl (meth) acrylate, polyoxyethylene mono (meth) acrylate, polyoxypropylene mono (meth) acrylate, polyoxybutylene mono (meth) acrylate, stearyl (meth) acrylate, acryloyl morpholine, tridecyl (meth) acrylate, Lauryl (meth) acrylate, dimethylacrylamide, hydroxyethylacrylamide, diethylacrylamide, isopropylacrylamide, dimethylaminopropylacrylamide, diacetoneacrylamide, Nn-butoxymethylacrylamide, N-isobutoxymethylacrylamide, N-methoxymethylacrylamide, N -Methylol acrylamide, N-vinyl caprolactam, decyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, benzyl (meth) acrylate, isodecyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopenta Nyl (meth) acrylate, dicyclopentenyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, octyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, cyclohexyl (meth) acrylate, t- Butylcyclohexyl (meth) acrylate, isoamyl (meth) acrylate, 2-ethylhexyl-diglycol (meth) acrylate, EO (ethylene oxide) modified 2-ethylhexyl (meth) acrylate, neopentyl glycol (meth) acrylic acid benzoic acid ester, N -Vinyl-2-pyrrolidone, N-vinylimidazole, tetrahydrofurfuryl (meth) acrylate, methoxydipropylene glycol (meth) acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl) methyl ( Examples thereof include meth) acrylate, cyclic trimethylol propaneformal (meth) acrylate, and ethoxy-diethylene glycol (meth) acrylate. In addition, when used in places that are visible to the human eye, such as outdoor advertisements and pradanes, it is preferable to use a monomer that does not leave an odor in the printed matter, such as tridecyl acrylate, ethoxydiethylene glycol acrylate, hydroxyethyl acrylamide, and N-acrylamide. Morphorine, N-methacryloylmorpholine, 1-acrylamidepyrrolidin-2-one, 1-methacryloylpyrrolidin-2-one, 1-acrylamidepiperidin-2-one, 1-methacryloylpiperidin-2-one, 2-hydroxy-3 -Phenoxypropyl (meth) acrylate, cyclic trimethylolpropaneformal (meth) acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl) methyl (meth) acrylate, hydroxyethylacrylamide, hydroxyethylmetha Acrylamide, dimethylaminopropylacrylamide, dimethylaminopropyl metaacrylamide, 4-t-butylcyclohexylacrylate and the like are preferable.

Among the above polyfunctional polymerizable monomers, 1,12-dodecanediol di (1,12-dodecanediol di) is a specific example of the polyfunctional polymerizable monomer (bifunctional polymerizable monomer) having two functional groups that show reactivity when irradiated with active energy rays. Meta) acrylate, 1,10-decanediol di (meth) acrylate, 2-methyl-1,8-octanediol di (meth) acrylate, 2-butyl-2-ethyl-1,3-propanediol di (meth) Acrylate, 1,9-nonandiol di (meth) acrylate, 1,8-octanediol di (meth) acrylate, 1,7-heptanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,4-Butanediol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, 3-methyl-1,5-pentanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate of hydroxypivalate, Tricyclodecanedimethanol diacrylate, cyclohexanedimethanol diacrylate, neopentyl glycol di (meth) acrylate, PO (propylene oxide) modified neopentyl glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, triethylene glycol Examples thereof include di (meth) acrylate, tripropylene glycol di (meth) acrylate, and dipropylene glycol di (meth) acrylate. In addition, when used in places that are visible to the human eye, such as outdoor advertisements and corrugated plastics, it is preferable to use a monomer that does not leave an odor in the printed matter, such as 3-methyl-1,5-pentanediol diacrylate and polyethylene glycol. Di (meth) acrylate, polypropylene glycol di (meth) acrylate and the like are preferable.

Specific examples of the polyfunctional polymerizable monomer having three or more functional groups exhibiting reactivity when irradiated with active energy rays (trifunctional or higher functional polyfunctional polymerizable monomer) include trimethylpropantri (meth) acrylate and ethoxy. Trimethylol propanetri (meth) acrylate, propoxylated trimethylol propanetri (meth) acrylate, glycerin tri (meth) acrylate ethoxylated, pentaerythritol tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate ethoxylated, EO modified Examples thereof include diglycerin tetra (meth) acrylate, ditrimethylolpropantetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and EO-modified dipentaerythritol hexa (meth) acrylate.

As used herein, the term (meth) acrylate means methacrylate or acrylate. Further, when the (meth) acrylate is prefixed with a plurality of prefixes such as di (meth) acrylate and tri (meth) acrylate, each (meth) acrylate may be the same or different. good.

The polymerizable oligomer is preferably an acrylate oligomer. The number of functional groups of the polymerizable oligomer is preferably 2 to 6, and the molecular weight of the polymerizable oligomer is preferably 2000 to 20000. Here, the molecular weight of the polymerizable oligomer is a polystyrene-equivalent weight average molecular weight.

Specific examples of the acrylate oligomer include urethane acrylate oligomer [acrylate oligomer having a plurality of urethane bonds (-NHCOO-)], amino acrylate oligomer [ _{acrylate oligomer having a plurality of amino groups (-NH 2} )], and epoxy acrylate oligomer [epoxy group]. Acrylate oligomer having a plurality of ester bonds [], silicone acrylate oligomer [acrylate oligomer having a plurality of siloxane bonds (-SiO−)], ester acrylate oligomer [acrylate oligomer having a plurality of ester bonds (-COO−)] and butadiene acrylate oligomer [butadiene unit A plurality of acrylate oligomers] and the like.

The following are known as acrylate oligomers.
Beam set 502H, beam set 505A-6, beam set 550B, beam set 575, beam set AQ-17 (manufactured by Arakawa Chemical Industry Co., Ltd.),
AH-600, UA-306H, UA-306T, UA-306I, UA-510H, UF-8001G (manufactured by Kyoeisha Chemical Co., Ltd.),
CN910, CN959, CN963, CN964, CN965NS, CN966NS, CN969NS, CN980NS, CN981NS, CN982, CN983NS, CN985, CN991NS, CN996NS, CN2920, CN2921, CN9881NS, CN2920, CN2921, CN9881NS, CN8883NS, CN9801NS CN9028, CN9030, CN9178NS, CN9290, CN9893NS, CN929, CN989NS, CN968NS, CN9006NS, CN9010NS, CN9025, CN9026, CN9039, CN9062, CN91110NS, CN9029, CN8885NS, CN9013NS, CN9885NS, CN9013NS, CN97895NS, CN9013NS, CN97895NS, CN9013NS CN971, CN972, CN975NS, CN9165 (manufactured by Sartmer),
U-2PPA, U-6LPA, U-10HA, U-10PA, UA-1100H, U-15HA, UA-53H, UA-33H, U-200PA, UA-200PA, UA-160TM, UA-290TM, UA- 4200, UA-4400, UA-122P (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.),
New Frontier R-1235, R-1220, RST-201, RST-402, R-1301, R-1304, R-1214, R-1302XT, GX-8801A, R-1603, R-1150D (Daiichi Kogyo Seiyaku) Made by the company),
EBECRYL204, EBECRYL205, EBECRYL210, EBECRYL215, EBECRYL220, EBECRYL230, EBECRYL244, EBECRYL245, EBECRYL264, EBECRYL265, EBECRYL270, EBECRYL280 / 15IB, EBECRYL284, EBECRYL285, EBECRYL294 / 25HD, EBECRYL1259, EBECRYL1290, KRM8200, EBECRYL4820, EBECRYL4858, EBECRYL5129, EBECRYL8210, EBECRYL8254, EBECRYL8301R, EBECRYL8307, EBECRYL8402, EBECRYL8405, EBECRYL8411, EBECRYL8465, EBECRYL8800, EBECRYL8804, EBECRYL8807, EBECRYL9260, EBECRYL9270, EBECRYL7735, EBECRYL8296, EBECRYL8452, EBECRYL8904, EBECRYL8311, EBECRYL8701, EBECRYL8667 (manufactured by Daicel-Orunekusu Co., Ltd.),
UV-1700B, UV-6300B, UV-7550B, UV-7600B, UV-7605B, UV-7610B, UV-7630B, UV-7640B, UV-7650B, UV-6630B, UV-7000B, UV-7510B, UV- 7461TE,
UV-2000B, UV-2750B, UV-3000B, UV-3200B, UV-3300B, UV-3310B, UV-3700B, UV6640B (manufactured by Nippon Synthetic Chemistry Co., Ltd.),
Art Resins UN-333, UN-350, UN-1255, UN-2600, UN-2700, UN-5590, UN-6060PTM, UN-6200, UN-6202, UN-6300, UN-6301, UN-7600, UN-7700, UN-9000PEP, UN-9200A, UN-3320HA, UN-3320HC, UN-904, UN-906S (manufactured by Negami Kogyo Co., Ltd.)
Aronix M-6100, M-6250, M-6500, M-7100, M-7300K, M-8030, M-8060, M-8100, M-8530, M-8560, M-9050 (manufactured by Toagosei)

In the ink composition of the present invention, the polymerizable compound (A) is a monofunctional polymerizable compound (a-1) having a molecular weight of 250 g / mol or less and a melting point of 25 ° C. or more, and having a molecular weight of 250 g / mol or less. A monofunctional polymerizable compound (a-2) having a melting point of less than 25 ° C. and a viscosity of 20 mPa · s or more at 25 ° C., and a monofunctional polymerizable compound (a-1) and a monofunctional polymerizable compound ( At least one monofunctional polymerizable compound (a) selected from the group consisting of a monofunctional polymerizable compound (a-3) having an amide group and a cyclic structure, which is a monofunctional polymerizable compound other than a-2). including.

The monofunctional polymerizable compound (a-1) is a highly crystalline polymerizable compound and has a high cohesive force. It is thought that the cohesive force is derived from the intramolecular interaction represented by the van der Waals bond, and when this is mixed with ink and printed, the bond derived from the cohesive force is formed, so that it is pseudo-dense. A film is formed, and bleed-out of an ultraviolet absorber or a radical trapping agent can be prevented without using a large amount of polyfunctional polymerizable monomer / oligomer. Further, since this film forms a high-density film by bonding without shrinkage due to cohesive force, it is possible to suppress the occurrence of cracks due to internal stress over time. This makes it possible to realize long-term weather resistance without causing cracks. Further, by blending the monofunctional polymerizable compound (a-1), the tack (adhesiveness) of the formed film can be reduced.

The molecular weight of the monofunctional polymerizable compound (a-1) is 250 g / mol or less. The lower limit of the molecular weight is not particularly limited, but is, for example, 100 g / mol or more. If the molecular weight is too low, it may give off a strong odor when dissolved in ink. The melting point of the monofunctional polymerizable compound (a-1) is 25 ° C. or higher, preferably 40 ° C. or higher. The upper limit of the melting point is not particularly limited, but is, for example, 250 ° C. or lower. When the monofunctional polymerizable compound (a-1) is a liquid, the viscosity at 25 ° C. is preferably 20 mPa · s or more from the viewpoint of enhancing the cohesive force. The viscosity at 25 ° C. can be measured with a rheometer (for example, Physica MCR301 manufactured by Anton Pearl Co., Ltd.).

The monofunctional polymerizable compound (a-1) preferably has a structure selected from the group consisting of an amide bond and a urethane bond, and particularly preferably has an amide bond. Specific examples of the monofunctional polymerizable compound (a-1) include isopropylacrylamide, ter-butylacrylamide, N-vinylcaprolactam and the like. Further, since high water resistance is required to realize long-term weather resistance, it is preferable to have a hydrophobic functional group, and it is more preferable that it is not easily soluble in water. The monofunctional polymerizable compound (a-1) may be used alone or in combination of two or more.

Further, the present inventor has a viscosity at 25 ° C. of 20 mPa · s or more even if the monofunctional polymerizable compound does not correspond to the monofunctional polymerizable compound (a-1) because the melting point is less than 25 ° C. The monofunctional polymerizable compound [that is, the monofunctional polymerizable compound (a-2)] is a highly crystalline polymerizable compound similar to the monofunctional polymerizable compound (a-1) and aggregates. It has been found that the strength is high and the same effect as that of the monofunctional polymerizable compound (a-1) can be exhibited.

The molecular weight of the monofunctional polymerizable compound (a-2) is 250 g / mol or less. The lower limit of the molecular weight is not particularly limited, but is, for example, 100 g / mol or more. If the molecular weight is too low, it may give off a strong odor when dissolved in ink. Further, the monofunctional polymerizable compound (a-2) has a viscosity at 25 ° C. of 20 mPa · s or more, and preferably 50 mPa · s or more. The upper limit of the viscosity is not particularly limited, but is, for example, 10000 mPa · s or less.

The monofunctional polymerizable compound (a-2) preferably has a structure selected from the group consisting of an amide bond and a urethane bond, and particularly preferably has an amide bond. Specific examples of the monofunctional polymerizable compound (a-2) include hydroxyethyl acrylamide and the like. Further, since high water resistance is required to realize long-term weather resistance, it is preferable to have a hydrophobic functional group, and it is more preferable that it is not easily soluble in water. The monofunctional polymerizable compound (a-2) may be used alone or in combination of two or more.

Furthermore, the present inventor has a monofunctional compound having an amide group and a cyclic structure even if it is a monofunctional polymerizable compound that does not correspond to the monofunctional polymerizable compound (a-1) and the monofunctional polymerizable compound (a-2). The polymerizable compound [that is, the monofunctional polymerizable compound (a-3)] is a highly crystalline polymerizable compound similar to the monofunctional polymerizable compound (a-1) and has a cohesive force. It was found that it is high and can exhibit the same effect as the monofunctional polymerizable compound (a-1).

Specific examples of the monofunctional polymerizable compound (a-3) include acryloyl morpholine and the like. Further, since high water resistance is required to realize long-term weather resistance, it is preferable to have a hydrophobic functional group, and it is more preferable that it is not easily soluble in water. The monofunctional polymerizable compound (a-3) may be used alone or in combination of two or more.

The amount of the monofunctional polymerizable compound (a) in the ink composition of the present invention is preferably in the range of 1 to 25% by mass, more preferably 2 to 20% by mass, and further preferably 5 to 15% by mass. .. If the amount of the monofunctional polymerizable compound (a) is too large, the viscosity of the ink tends to be high, which may cause ejection defects during printing, precipitation during ink storage, and the like.

In the ink composition of the present invention, it is preferable to use a polyfunctional polymerizable compound from the viewpoint of improving water resistance. However, if a polyfunctional polymerizable compound is used, it may cause cracks, so it is desirable to use it to the extent that cracks do not occur. Therefore, the polymerizable compound (A) preferably contains a polyfunctional polymerizable oligomer, and more preferably contains a trifunctional or higher functional polymerizable oligomer. By blending a trifunctional or higher functional polymerizable oligomer together with the monofunctional polymerizable compound (a) and containing an appropriate amount, bleed-out of (C) ultraviolet absorber and (D) radical scavenger is suppressed and coated. The weather resistance of the film can be ensured. Further, in the ink composition of the present invention, the amount of the polyfunctional polymerizable oligomer is preferably in the range of 30% by mass or less, more preferably 3 to 20% by mass, and further preferably 5 to 18% by mass.

The (B) photopolymerization initiator used in the ink composition of the present invention has an action of initiating the polymerization of the above-mentioned polymerizable compound by being irradiated with active energy rays. The amount of the photopolymerization initiator (B) is preferably 1 to 25% by mass, more preferably 3 to 20% by mass, and even more preferably 3 to 15% by mass in the ink composition. (B) If the content of the photopolymerization initiator is less than 1% by mass, the printing layer may be poorly cured, and if it exceeds 25% by mass, precipitates are generated at a low temperature and ink ejection becomes unstable. May become. Further, in order to accelerate the initiation reaction of (B) the photopolymerization initiator, it is also possible to use an auxiliary agent such as a photosensitizer in combination.

Examples of the (B) photopolymerization initiator include benzophenone-based compounds, acetophenone-based compounds, thioxanthone-based compounds, and phosphine oxide-based compounds. From the viewpoint of curability, the wavelength of the activated energy ray to be irradiated and the start of photopolymerization. It is preferable that the absorption wavelengths of the agents overlap as much as possible. In particular, the (B) photopolymerization initiator preferably contains an acylphosphine oxide-based initiator from the viewpoint of LED curing and coloring during curing. The photopolymerization initiator (B) may be used alone or in combination of two or more.

(B) As a specific example of the photopolymerization initiator,
2,2-dimethoxy-1,2-diphenylethane-1-one,
1-Hydroxy-cyclohexyl-phenyl-ketone,
2-Hydroxy-2-methyl-1-phenylpropane-1-one,
Benzophenone,
1- [4- (2-Hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1-one,
2-Hydroxy-1- {4- [4- (2-hydroxy-2-methylpropionyl) -benzyl] -phenyl} -2-methyl-propan-1-one,
Phenyl Glyoxylic Acid Methyl Ester,
2-Methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one,
2-Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone,
2-Dimethylamino-2- (4-methyl-benzyl) -1- (4-morpholin-4-yl-phenyl) -butane-1-one,
Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide,
Bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide,
2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide,
1,2-octanedione, 1- [4- (phenylthio) -2- (O-benzoyloxime)],
Etanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl]-, 1- (O-acetyloxime),
2,4-Diethylthioxanthone,
2-Isopropylthioxanthone,
2-Chlorothioxanthone and the like can be mentioned.

Among these, from the viewpoint of ink curability, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone, Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl -Phenylphosphine oxide and 2,4-diethylthioxanthone are preferable, and further, from the viewpoint of LED curing and coloring during curing, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (2,6) -Dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide are preferred, and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide. Is particularly preferable.

The (C) ultraviolet absorber that can be used in the ink composition of the present invention has an effect of absorbing ultraviolet rays and preventing deterioration due to ultraviolet rays. Examples of the ultraviolet absorber (C) include cyanoacrylate-based compounds, benzophenone-based compounds, benzoate-based compounds, benzotriazole-based compounds, hydroxyphenyltriazine-based compounds, benziliden camphor-based compounds, inorganic fine particles, and the like. A hydroxyphenyltriazine-based compound having a shorter wavelength is preferable from the viewpoint of ink curability. Further, among the hydroxyphenyltriazine compounds, solid compounds are particularly preferable, and they tend to have lower fluidity and less bleed-out than liquid compounds. From the viewpoint of curability, it is preferable that the wavelength of the active energy ray to be irradiated and the absorption wavelength of the (C) ultraviolet absorber do not overlap as much as possible.

(C) As a specific example of the ultraviolet absorber,
2,4-Dihydroxybenzophenone,
2-Hydroxy-4-methoxybenzophenone,
2-Hydroxy-4-methoxybenzophenone-5-sulfonic acid,
2-Hydroxy-4-octoxybenzophenone,
2-Hydroxy-4-dodecyloxybenzophenone-2-hydroxy-4-benzyloxybenzophenone,
Bis (5-benzoyl-4-hydroxy-2-methoxyphenyl) methane,
2,2'-Dihydroxy-4-methoxybenzophenone,
2,2'-Dihydroxy-4,4'-dimethoxybenzophenone,
2,2', 4,4'-tetrahydroxybenzophenone,
2-Hydroxy-4-methoxy-2'-carboxybenzophenone,
2- (2'-Hydroxy-5'-methylphenyl) benzotriazole 2- [2'-hydroxy-3', 5'-bis (α, α- (dimethylbenzyl) phenyl] benzotriazole,
2- (2'-Hydroxy-3', 5'-di-t-butylphenyl) benzotriazole,
2- (2'-Hydroxy-3'-t-Butyl-5'-Methylphenyl) -5-chlorobenzotriazole,
2- (2'-Hydroxy-3', 5'-di-t-butylphenyl) -5-chlorobenzotriazole,
2- (2'-Hydroxy-3', 5'-di-t-amylphenyl) benzotriazole,
2- (2'-Hydroxy-5'-t-octylphenyl) benzotriazole,
2,2'-Methylene-bis [4- (1,1,3,3-tetramethylbutyl) -6- (2N-benzotriazole-2-yl) phenol],
Condensation of methyl-3- [3-t-butyl-5- (2H-benzotriazole-2-yl) -4-hydroxyphenyl] propionate and polyethylene glycol,
2- (2-Hydroxyphenyl) benzotriazole,
2- (2'-Hydroxy-5'-methylphenyl) benzotriazole,
2,6-di-t-butylphenyl-3', 5'-di-t-butyl-4'-hydroxybenzoate,
Hexadecyl-3,5-di-t-butyl-4-hydroxybenzoate and the like can be mentioned.

In the ink composition of the present invention, the amount of the (C) ultraviolet absorber is preferably in the range of 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, still more preferably 1 to 5% by mass. It is preferably inside. If the amount of UV absorber is too large, the print layer may not be sufficiently cured. The (C) ultraviolet absorber may be used alone or in combination of two or more, but the (C) ultraviolet absorber preferably contains at least two types of ultraviolet absorbers. By using a plurality of types of ultraviolet absorbers having different structures, the effect of the ultraviolet absorber can be further sustained.

In the ink composition of the present invention, the value B obtained by the following formula (1) is preferably 100 or more, more preferably 120, for the (C) ultraviolet absorber in relation to the (A) polymerizable compound. It is more than that, and more preferably 200 or more. The upper limit of the value B is, for example, 20000 or less.
Molecular weight of UV absorber (g / mol) / | SP value of UV absorber-Average SP value of polymerizable compound | = B ... Formula (1)
The above formula (1) is derived from the compatibility (SP value) between the ultraviolet absorber (UVA) and the printing layer and the molecular weight of UVA. When the above value B is 100 or more, the effect of suppressing UVA bleed-out is high. When the above value B is less than 100, the difference (absolute value) between the SP values of UVA and the polymerizable compound is large and / or the molecular weight of UVA is low, so that the effect of suppressing the bleed-out of the ultraviolet absorber is low. There is.

[Calculation method of SP value]
In the present specification, the SP value of the ultraviolet absorber and the polymerizable compound is the value of the Hansen solubility parameter, and is calculated by using the Y-MB method.

[Calculation method of average SP value]
(A) When the polymerizable compound is composed of n kinds of polymerizable compounds, the SP values of each polymerizable compound are SP ¹ , SP ² , ..., SP ⁿ , respectively, and the mass fraction of each polymerizable compound is W. ¹ , W ² , ..., W ⁿ (W ¹ + W ² + ... + W ⁿ = 1) can be obtained from the following equation.
Average SP value = SP ¹ x W ¹ + SP ² x W ² + ... + SP ⁿ x W ⁿ

The (D) radical scavenger that can be used in the ink composition of the present invention can capture free radicals and the like and improve photostability. Further, a substance having a function of reacting with free radicals and preventing a polymerization reaction from occurring (so-called polymerization inhibitor) is also included in the (D) radical scavenger. Examples of the (D) radical scavenger include hindered amine compounds, hydroquinone compounds, phenol compounds, phenothiazine compounds, nitroso compounds, N-oxyl compounds and the like, and in particular, hindered amine light stabilizers (HALS) are used. preferable.

Specific examples of the (D) radical trapping agent include bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and 1- {2- (3- (3,5-di-t-butyl). -4-Hydroxyphenyl) propionyloxy) ethyl} -2,2,6,6-tetramethylpiperidine, 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro {4.5} Hindered amine compounds such as decane-2,4-dione, phenol, o-, m- or p-cresol, 2-t-butyl-4-methylphenol, 6-t-butyl-2,4 -Dimethylphenol, 2,6-di-t-butyl-4-methylphenol, 2-t-butylphenol, 4-t-butylphenol, 2,4-di-t-butylphenol, 2-methyl-4-t-butylphenol , 4-t-butyl-2,6-dimethylphenol and other phenolic compounds, hydroquinone, hydroquinone monomethyl ether, methylhydroquinone, 2,5-di-t-butylhydroquinone, 2-methyl-p-hydroquinone, 2,3 -Dimethylhydroquinone, trimethylhydroquinone 4-methylbenzcatechin, t-butylhydroquinone, 3-methylbenzcatechin, 2-methyl-p-hydroquinone, 2,3-dimethylhydroquinone, trimethylhydroquinone, t-butylhydroquinone, benzoquinone, t- Hydroquinone compounds such as butyl-p-benzoquinone and 2,5-diphenyl-p-benzoquinone, phenothiazine compounds such as phenothiazine, N-nitroso-N-phenylhydroxylamine ammonium, N-nitroso-N-phenylhydroxylamine aluminum salt Nitroso compounds such as 4-hydroxy-2,2,6,6-tetramethyl-piperidin-N-oxyl, 4-oxo-2,2,6,6-tetramethyl-piperidin-N-oxyl, 4- Examples thereof include N-oxyl compounds such as methoxy-2,2,6,6-tetramethyl-piperidin-N-oxyl.

In the ink composition of the present invention, the amount of the (D) radical scavenger is preferably in the range of 10% by mass or less, more preferably 7% by mass or less, still more preferably 5% by mass or less. Too much radical scavenger can cause poor curing. The lower limit of the content of the radical scavenger (D) is, for example, 0.01% by mass or more, preferably 0.1% by mass or more, and more preferably 0.5% by mass or more. (D) The radical scavenger may be used alone or in combination of two or more.

The ink composition of the present invention may contain a colorant such as a dye or a pigment, but in that case, it is preferable to contain a pigment from the viewpoint of weather resistance. For example, it is also possible to make a metallic ink by using a metal pigment. The content of the colorant is, for example, 0.1 to 15% by mass in the ink composition. Further, the colorant may be used alone or in combination of two or more.

Specific examples of the above colorants include
C. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 9, 10, 12, 13, 14, 15, 16, 17, 24, 32, 34, 35, 36, 37, 41, 42, 43, 49, 53, 55, 60, 61, 62, 63, 65, 73, 74, 75, 77, 81, 83, 87, 93, 94, 95, 97, 98, 99, 100, 101, 104, 105, 106, 108, 109, 110, 111, 113, 114, 116, 117, 119, 120, 123, 124, 126, 127, 128, 129, 130, 133, 138, 139, 150, 151, 152, 153, 154, 155, 165, 167, 168, 169, 170, 172, 173, 174, 175, 176, 179, 180, 181, 182, 183, 184, 185, 191, 193, 194, 199, 205, 206, 209, 212, 213, 214, 215, 219,
C. I. Pigment Orange 1, 2, 3, 4, 5, 13, 15, 16, 17, 19, 20, 21, 24, 31, 34, 36, 38, 40, 43, 46, 48, 49, 51, 60, 61, 62, 64, 65, 66, 67, 68, 69, 71, 72, 73, 74, 81,
C. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 21, 22, 23, 31, 32, 38, 41, 48, 48: 1, 48: 2, 48: 3, 48: 4, 48: 5, 49, 52, 52: 1, 52: 2, 53: 1, 54, 57: 1, 58, 60: 1, 63, 64: 1, 68, 81: 1, 83, 88, 89, 95, 101, 104, 105, 108, 112, 114, 119, 122, 123, 136, 144, 146, 147, 149, 150, 164, 166, 168, 169, 170, 171, 172, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 187, 188, 190, 193, 194, 200, 202, 206, 207, 208, 209, 210, 211, 213, 214, 216, 220, 220, 221, 224, 226, 237, 238, 239, 242, 245, 247, 248, 251, 253, 254, 255, 256, 257, 258, 260, 262, 263, 264, 266, 268, 269, 270, 271, 272, 279,
C. I. Pigment Violet 1, 2, 3, 3: 1, 3: 3, 5: 1, 13, 15, 16, 17, 19, 23, 25, 27, 29, 31, 32, 36, 37, 38, 42, 50,
C. I. Pigment Blue 1, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 5, 15: 6, 16, 17: 1, 24, 24: 1, 25, 26, 27, 28, 29, 36, 56, 60, 61, 62, 63, 75, 79, 80,
C. I. Pigment Green 1, 4, 7, 8, 10, 15, 17, 26, 36, 50,
C. I. Pigment Brown 5, 6, 23, 24, 25, 32, 41, 42,
C. I. Pigment Black 1, 6, 7, 9, 10, 11, 20, 26, 28, 31, 32, 34,
C. I. Pigment White 1, 2, 4, 5, 6, 7, 11, 12, 18, 19, 21, 22, 23, 26, 27, 28,
Examples include aluminum flakes, glass flakes, pearl pigments and hollow particles.

Among these, from the viewpoint of weather resistance and color reproducibility of the print layer,
C. I. Pigment Black 7,
C. I. Pigment Blue 15: 3, C.I. I. Pigment Blue 15: 4, C.I. I. Pigment Blue 28,
C. I. Pigment Red 101, C.I. I. Pigment Red 122, C.I. I. Pigment Red 202, C.I. I. Pigment Red 254, C.I. I. Pigment Red 282,
C. I. Pigment Violet 19,
C. I. Pigment White 6,
C. I. Pigment Yellow 42, C.I. I. Pigment Yellow 120, C.I. I. Pigment Yellow 138, C.I. I. Pigment Yellow 139, C.I. I. Pigment Yellow 150, C.I. I. Pigment Yellow 151, C.I. I. Pigment Yellow 155, C.I. I. Pigment Yellow 213 is preferred.

The ink composition of the present invention may contain various compounds for the purpose of imparting functionality, and may contain, for example, calcium carbonate, barium sulfate, etc. in order to increase the altitude of the obtained ink film. Indium tin composite oxide, antimony tin composite oxide, etc. may be contained in order to impart a heat ray absorbing function to the obtained ink film, and fine particle titanium oxide, fine particle oxidation, etc. may be contained in order to increase the refractive index of the obtained ink film. It may contain zirconium or the like.

From the viewpoint of ejection stability, the pigment particles dispersed in the ink composition preferably have a volume average particle diameter of 0.05 to 0.4 μm and a volume maximum particle diameter of 0.2 to 1 μm. .. If the volume average particle size is larger than 0.4 μm and the volume maximum particle size is larger than 1 μm, it tends to be difficult to stably eject the ink composition. The volume average particle size and the volume maximum particle size can be measured by a measuring device using a dynamic light scattering method.

The ink composition of the present invention may further contain a pigment dispersant, if necessary, in order to disperse the pigment. The content of the pigment dispersant is, for example, 0.1 to 5% by mass in the ink composition. Further, the pigment dispersant may be used alone or in combination of two or more.

Specific examples of the pigment dispersant include
ANTI-TERRA-U, ANTI-TERRA-U100,
ANTI-TERRA-204, ANTI-TERRA-205,
DISPERBYK-101, DISPERBYK-102,
DISPERBYK-103, DISPERBYK-106,
DISPERBYK-108, DISPERBYK-109,
DISPERBYK-110, DISPERBYK-111,
DISPERBYK-112, DISPERBYK-116,
DISPERBYK-130, DISPERBYK-140,
DISPERBYK-142, DISPERBYK-145,
DISPERBYK-161, DISPERBYK-162,
DISPERBYK-163, DISPERBYK-164,
DISPERBYK-166, DISPERBYK-167,
DISPERBYK-168, DISPERBYK-170,
DISPERBYK-171, DISPERBYK-174,
DISPERBYK-180, DISPERBYK-182,
DISPERBYK-183, DISPERBYK-184,
DISPERBYK-185, DISPERBYK-2000,
DISPERBYK-2001, DISPERBYK-2008,
DISPERBYK-2009, DISPERBYK-2020,
DISPERBYK-2025, DISPERBYK-2050,
DISPERBYK-2070, DISPERBYK-2096,
DISPERBYK-2150, DISPERBYK-2155,
DISPERBYK-2163, DISPERBYK-2164,
BYK-P104, BYK-P104S, BYK-P105,
BYK-9076, BYK-9077, BYK-220S, BYKJET-9150, BYKJET-9151 (all manufactured by Big Chemie Japan),
Solspace 3000, Solspace 5000,
Solspace 9000, Solspace 11200,
Solspace13240, Solspace13650,
Solspace13940, Solspace16000,
Solspace 17000, Solspace 18000,
Solspace 20000, Solspace 21000,
Solspace24000SC, Solspace24000GR,
Solspace26000, Solspace27000,
Solspace28000, Solspace32000,
Solspace32500, Solspace32550,
Solspace32600, Solspace33000,
Solspace34750, Solspace35100,
Solspace35200, Solspace36000,
Solspace 36600, Solspace 37500,
Solspace 38500, Solspace 39000,
Solspace 41000, Solspace 54000,
Solspace 55000, Solspace 56000,
Solspace71000, Solspace76500,
Solspace X300 (above, manufactured by Lubrizol),
Disparon DA-7301, Disparon DA-325, Disparon DA-375, Disparon DA-234 (all manufactured by Kusumoto Kasei Co., Ltd.),
Floren AF-1000, Floren DOPA-15B, Floren DOPA-15BHFS, Floren DOPA-17HF, Floren DOPA-22, Floren DOPA-33, Floren G-600, Floren G-700, Floren G-700AMP, Floren G-700DMEA, Floren G-820, Floren G-900, Floren GW-1500, Floren KDG-2400, Floren NC-500, Floren WK-13E, (all manufactured by Kyoeisha Chemical Co., Ltd.),
TEGO Dispers 610, TEGO Dispers 610S,
TEGO Dispers 630, TEGO Dispers 650,
TEGO Dispers 652, TEGO Dispers 655,
TEGO Dispers 662C, TEGO Dispers 670,
TEGO Dispers 685, TEGO Dispers 700,
TEGO Dispers 710, TEGO Dispers 740W,
LIPOTIN A, LIPOTIN BL,
LIPOTIN DB, LIPOTIN SB (all manufactured by Evonik Degusa),
PB821, PB822, PN411, PA111 (all manufactured by Ajinomoto Fine Techno Co., Ltd.),
Texahole 963, Texahole 964, Texahole 987, Texahole P60, Texahole P61, Texahole P63, Texahole 3250, Texahole SF71, Texahole UV20, Texahole UV21 (all manufactured by Cognis),
Examples thereof include BorchiGenSN88 and BorchiGen0451 (all manufactured by Bocious).

The ink composition of the present invention may further contain a surface conditioner from the viewpoint of improving wettability and the like. As used herein, the surface conditioner means a substance that has a hydrophilic part and a hydrophobic part in the molecular structure and can adjust the surface tension of the ink composition by adding it.

Specific examples of the surface conditioner that can be used in the ink composition of the present invention include anionic surface conditioners such as dialkyl sulfosuccinates, alkylnaphthalene sulfonates, and fatty acid salts, polyoxyethylene alkyl ethers, and polyoxyethylene. Nonionic surface conditioners such as alkylallyl ethers, acetylene glycols, polyoxyethylene / polyoxypropylene block copolymers, cationic surface conditioners such as alkylamine salts and quaternary ammonium salts, acrylic surface conditioners, Examples include silicon-based surface conditioners and fluorine-based surface conditioners. In particular, a silicon-based surface conditioner or an acrylic surface conditioner is preferable, and commercially available products such as Big Chemie, Evonik, and Toray Dow Corning can be used. Further, in the case of a silicone-based surface conditioner, it is preferable that the silicone-based surface conditioner is a polyether-modified silicone oil and has an HLB of 7.6 to 12.

The amount of the surface conditioner in the ink composition of the present invention can be appropriately selected depending on the intended use, but is preferably 0.01 to 1% by mass in the ink composition, for example. The surface conditioner may be used alone or in combination of two or more.

As a specific example of the above surface conditioner,
BYK-300, BYK-302, BYK-306, BYK-307, BYK-310, BYK-313, BYK-315N, BYK-320, BYK-322, BYK-323, BYK-325, BYK-326, BYK- 330, BYK-331, BYK-333, BYK-342, BYK-345, BYK-346, BYK-347, BYK-348, BYK-349, BYK-350, BYK-354, BYK-355, BYK-356, BYK-358N, BYK-361N, BYK-370, BYK-375, BYK-377, BYK-378, BYK-381, BYK-392, BYK-394, BYK-399, BYK-3440, BYK-3441, BYK- 3455, BYK-3550, BYK-3560, BYK-3565, BYK-3760, BYK-DYNWET 800N, BYK-SILCLEAN 3700, BYK-SILCLEAN 3701, BYK-SILCLEAN 3720, BYK-UV3500, BYK-UV3500, BYK-UV3500 BYK-UV3530, BYK-UV3535, BYK-UV3570, BYK-UV3575, BYK-UV3576 (all manufactured by Big Chemie Japan),
TEGO Flow 300, TEGO Flow 370, TEGO Flow 425, TEGO Flow ATF 2, TEGO Flow ZFS 460, TEGO Glide 100, TEGO Glide 110, TEGO Glide 110, TEGO Glide 130, TEGO TEGO Glide 432, TEGO Glide 435, TEGO Glide 440, TEGO Glide 450, TEGO Glide 482, TEGO Glide A 115, TEGO Glide B 1484, TEGO Glide B 1484, TEGO Glide ZG 400
501W ADDITIVE, FZ-2104, FZ-2110, FZ-2123, FZ-2164, FZ-2191, FZ-2203, FZ-2215, FZ-2222, FZ-5609, L-7001, L-7002, L-7604 , OFX-0193, OFX-0309 FLUID, OFX-5221 FLUID, SF 8410 FLUID, SH3771, SH 3746 FLUID, SH 8400 FLUID, SH 8700 FLUID, Y-7006 (all manufactured by Toray Dow Corning),
KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF-615A, KF-640, KF-642, KF-643, KF-644, KF-945, KF-6004, KF- Examples thereof include 6011, KF-6012, KF-6015, KF-6017, KF-6020, KF-6204, X-22-2516, and X-22-4515 (all manufactured by Shin-Etsu Chemical Co., Ltd.).

Among these, from the viewpoint of structure and HLB, 501W ADDITIVE, FZ-2104, FZ-2123, FZ-2215, L-7002, OFX-0309 FLUID, OFX-5221 FLUID, SH 8400 FLUID, KF-351A, KF- 353, KF-355A, KF-615A, KF-642, KF-644, KF-6004, KF-6011, KF-6204 are preferable.

The ink composition of the present invention has other components such as an antioxidant, a plasticizer, a rust preventive, a solvent, a non-reactive polymer, a filler, an antifoaming agent, a charge control agent, a stress relaxant, a penetrant, and a derivative. Additives such as a light material, a bright material, a magnetic material, and a phosphor may be used as needed.

The ink composition of the present invention can be obtained by mixing various components appropriately selected as necessary and using a filter having a pore size of about 1/10 or less of the nozzle diameter of the inkjet printhead to be used, if necessary. It can be prepared by filtering the resulting mixture.

The ink composition of the present invention preferably has a viscosity at 40 ° C. of 5 to 25 mPa · s, and more preferably 5 to 20 mPa · s. When the ink viscosity at 40 ° C. is within the above-specified range, good ejection stability can be obtained. The ink viscosity can be measured using a cone plate type viscometer.

The ink composition of the present invention preferably has a surface tension of 20 to 35 mN / m at 25 ° C., and more preferably 23 to 33 mN / m. When the ink surface tension at 25 ° C. is within the above-specified range, good ejection stability can be obtained. The ink surface tension can be measured by the plate method.

The ink composition of the present invention is preferably a clear ink. In the present specification, the clear ink refers to a clear ink having a light transmittance of 80% or more in a wavelength range of 380 to 800 nm when a film having a thickness of 30 μm is formed, and the light transmittance is preferably 90% or more. , More preferably 95% or more, still more preferably 97% or more. In the present specification, the light transmittance is measured according to JIS K7361-1: 1997 "Plastic-Test method for total light transmittance of transparent material-Part 1: Single beam method".

The ink composition of the present invention is preferably used for surface protection. Specifically, the ink composition of the present invention is preferably a clear ink for protecting the surface of a colored layer, particularly a colored layer containing a dye or an organic pigment. The colored layer is, for example, a colored layer formed by at least one of a paint, an ink (for example, a printing ink, an inkjet ink) and a powder toner. By protecting the surface of the colored layer with the ink composition of the present invention, the weather resistance and light resistance of the colored layer are improved, and a vivid appearance can be maintained even when used outdoors.

Next, the method of forming the decorative body of the present invention will be described. The method for forming a decorative body of the present invention is characterized in that printing (preferably inkjet printing) is performed on the surface of a colored layer formed on a base material with the above-mentioned ink composition of the present invention. The method for forming a decorative body of the present invention can provide a decorative body having excellent long-term weather resistance. Further, the decorative body can be easily provided by using the existing printing device without using a large-scale laminating device or the like.

In the method for forming a decorative body of the present invention, the base material is not particularly limited, but a base material used in an industrial line is preferably mentioned. The shape of the base material includes, for example, a film shape, a sheet shape, a plate shape, and the like. Examples of the material of the base material include epoxy resin, ABS resin, polycarbonate, polyvinyl chloride, polystyrene, and acrylic resin, particularly plastics such as polymethylmethacrylate (PMMA), polyethylene terephthalate (PET), and polypropylene (PP). Examples thereof include metals such as iron, stainless steel and aluminum, wood, cement, concrete, plaster, calcium silicate, calcium carbonate and glass. Specific examples of the base material include vinyl chloride sheet, tarpaulin, praddan (plastic cardboard), acrylic board, flexible board, calcium silicate board, gypsum slug bar light board, calcium carbonate board, wood piece cement board, precast concrete board, and lightweight. Examples include foamed concrete (ALC) boards, gypsum boards, tiles, glass boards and the like.

In the method for forming a decorative body of the present invention, the base material may be surface-treated from the viewpoint of improving the adhesiveness and color-developing property of the colored layer. For example, the substrate may have an undercoat layer on its surface.

The colored layer is a colored layer containing a colorant such as a dye or a pigment, and is used for decoration. Further, even if the colored layer is a layer containing a dye or an organic pigment and has a problem in weather resistance or light resistance, the surface of the colored layer is protected by the ink composition of the present invention, so that the weather resistance of the colored layer is protected. , Light resistance can be improved. The colored layer is, for example, a colored layer formed by at least one of a paint, an ink (for example, a printing ink, an inkjet ink) and a powder toner.

In addition to colorants, the colored layer includes resins, ultraviolet absorbers, radical scavengers, antioxidants, plasticizers, rust inhibitors, fillers, charge control agents, light guide materials, bright materials, magnetic materials, phosphors, etc. Wax and the like can be included as needed.

The colored layer is formed on at least a part of a surface such as a base material or an undercoat layer formed on the base material.

Although printing is preferably performed by an inkjet printing method, the printing is not limited to this, and printing may be performed by various printing methods such as a gravure printing method, an offset printing method, a flexographic printing method, a screen printing method, and a coater method. It is possible.

For inkjet printing, it can be used in various inkjet printers. Examples of the inkjet printer include an inkjet printer that ejects an ink composition by a charge control method or a piezo method. Further, a large-sized inkjet printer, specifically, an inkjet printer for printing on an article produced on an industrial line can also be preferably used.

By printing with the ink composition of the present invention, an ink layer, preferably a clear ink layer (also referred to as a clear layer) is formed on the colored layer. Here, when there is a portion of the surface such as the base material or the undercoat layer formed on the base material where the colored layer does not exist, the ink layer is the undercoat layer formed on the base material or the base material. It may be formed on a surface such as.

The ink layer formed by printing using the ink composition of the present invention is cured by irradiation with active energy rays such as ultraviolet rays. As the light source of the active energy ray, a high-pressure mercury lamp, a metal halide lamp, an LED lamp, or the like can be used. Further, the wavelength of the active energy ray irradiated to cure the ink layer preferably overlaps with the absorption wavelength of the photopolymerization initiator, and the main wavelength of the active energy ray is preferably 350 to 400 nm. The integrated light intensity of the active energy rays is preferably in the range of ^{100 to 2000 mJ / cm 2.}

The ink composition of the present invention can be subjected to surface finishing such as gloss-like and matte-like by appropriately selecting the ejection conditions for inkjet printing and the subsequent curing conditions. For example, if the ink composition is spread and then cured after a while, it becomes glossy, and if the ink droplets are cured in a lenticular shape, it becomes matte.

Next, the decorative body of the present invention will be described. The decorative body of the present invention includes a base material, a colored layer formed on the base material, and a clear layer formed on the colored layer, wherein the clear layer has the ink composition of the present invention described above. It is characterized by being formed by an object. The decorative body of the present invention has excellent long-term weather resistance. The decorative body of the present invention can be produced by the method for forming the decorative body of the present invention described above.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

<Ink preparation method>
A mixture containing the components shown in Tables 1 to 5 in an amount (parts by mass) shown in Tables 1 to 5 is stirred and dissolved to make it uniform, and then filtered, and shown in Examples 1 to 40 and Comparative Examples 1 to 6. An active energy ray-curable inkjet ink was prepared.

The details of the components shown in Tables 1 to 5 are shown below.
1) N-vinylcaprolactam, molecular weight 139 g / mol, melting point 37 ° C., SP value 19.9
2) N-isopropylacrylamide, molecular weight 113 g / mol, melting point 62 ° C, SP value 21.5
3) Hydroxyethyl acrylamide, molecular weight 115 g / mol, melting point 22 ° C, viscosity 200 mPa · s at 25 ° C, SP value 29.3
4) Acryloyl morpholine, molecular weight 141 g / mol, melting point -8 ° C, viscosity 10.2 mPa · s at 25 ° C, SP value 22.8
5) 4-tertBucyclohexyl acrylate, viscosity at 25 ° C., 8.3 mPa · s, SP value 16.7
6) Tetrahydrofurfuryl acrylate, viscosity at 25 ° C. 2.7 mPa · s, SP value 19.0
7) Pentaerythritol triacrylate, SP value 20.8
8) Dipentaerythritol hexaacrylate, SP value 18.6
9) Aronix M-6250, polyester (meth) acrylate oligomer, number of functional groups 2, manufactured by Toa Synthetic Co., Ltd. 10) Aronix M-8100, polyester (meth) acrylate oligomer, number of functional groups 3 or more, manufactured by Toa Synthetic Co., Ltd. 11) Aronix M- 7100, polyester (meth) acrylate oligomer, number of functional groups 3 or more, 12) Speedcure TPO, photopolymerization initiator, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, Rambson 13) TINUVIN 405, hydroxy Phenyltriazine-based UV absorber, manufactured by BASF, molecular weight 584, SP value 19.5
14) TINUVIN 900, benzotriazole UV absorber, manufactured by BASF, molecular weight 448, SP value 19.6
15) TINUVIN 400, hydroxyphenyltriazine UV absorber, manufactured by BASF, molecular weight 647, SP value 23.7
16) TINUVIN PS, hydroxyphenylbenzotriazole UV absorber, manufactured by BASF, molecular weight 267, SP value 21.4
17) EVERSORB 90, hindered amine radical scavenger, manufactured by Taiwan Yongguang Chemical Industry Co., Ltd.

<Weather resistance test 1. ΔE>
Accelerated weather resistance (based on JIS K 5600-7-7: 2008)
With a UV inkjet printer C.I. I. A 100% solid image (720x600 dpi) is printed using UV ink containing 3% Pigment Yellow 150, and after curing, the inks shown in Tables 1 to 5 are applied on the printed matter with a bar coater # 10, and then the active energy is activated. Obtain the color difference ΔE between the L * a * b * color measurement value on the cured film that has been sufficiently cured by irradiating with a line (main wavelength 385 nm) and the color measurement value after 1500 hours of the accelerated weather resistance test. Evaluated based on the criteria of. The results are shown in Tables 1-5.
⊚: Color difference ΔE from the color measurement value before the test is less than 3 ○: Color difference ΔE from the color measurement value before the test is 3 or more and less than 5 Δ: Color difference ΔE from the color measurement value before the test is 5 or more and less than 10 × : Color difference ΔE from the color measurement value before the test is 10 or more

<Weather resistance test 2. Crack resistance>
Accelerated weather resistance (based on JIS K 5600-7-7: 2008)
<Weather resistance test 1. A cured film was prepared in the same manner as ΔE>, and an accelerated weather resistance test was carried out.
After the test time was up to 1500 hours, the appearance of the coating film was visually evaluated based on the following criteria.
⊚: There are no cracks even after the test time of 1500 hours.
〇: Cracks occurred during the test time of 1200-1500 hours.
Δ: Cracks occurred after the test time of 1000-1200 hours.
X: A crack occurred 1000 hours before the test time.

<Curable>
After applying the inks shown in Tables 1 to 5 on the acrylic plate with bar coater # 10 ^{, irradiate the acrylic plate with active energy rays (LED385 nm) at 2000 mW / cm 2} and 1000 mJ / cm ² to touch the curing condition of the coating film. And evaluated.
⊚: There is no tack and no fingerprints remain.
〇: There is some tack, but no fingerprints remain.
Δ: There is a tack, and some fingerprints remain when pressed strongly.
X: Curing is insufficient and the printed film has a liquid feeling.

Claims (12)

An active energy ray-curable ink composition containing (A) a polymerizable compound, (B) a photopolymerization initiator, (C) an ultraviolet absorber and / or (D) a radical trapping agent, according to the above (A). ) The polymerizable compound contains a monofunctional polymerizable compound and a polyfunctional polymerizable compound, and the monofunctional polymerizable compound has a molecular weight of 250 g / mol or less and a melting point of 25 ° C. or more (a). -1), the monofunctional polymerizable compound (a-2) having a molecular weight of 250 g / mol or less, a melting point of less than 25 ° C., and a viscosity of 20 mPa · s or more at 25 ° C., and the monofunctional polymerizable compound. Select from the group consisting of monofunctional polymerizable compounds other than (a-1) and the monofunctional polymerizable compound (a-2), which consist of a monofunctional polymerizable compound (a-3) having an amide group and a cyclic structure. An ink composition comprising at least one monofunctional polymerizable compound (a) to be formed. The ink composition according to claim 1, wherein the content of the monofunctional polymerizable compound (a) in the ink composition is 1% by mass or more and 25% by mass or less. The ink composition according to claim 1 or 2, wherein the amount of the monofunctional polymerizable compound in the ink composition is in the range of 70 to 90% by mass. Claims 1 to 3, wherein the polyfunctional polymerizable compound contains a polyfunctional polymerizable oligomer, and the amount of the polyfunctional polymerizable oligomer in the ink composition is within the range of 30% by mass or less. The ink composition according to any one. The invention according to any one of claims 1 to 4, wherein the ink composition contains a monofunctional polymerizable compound in an amount of 70 to 90% by mass and a polyfunctional polymerizable oligomer in the range of 3 to 20% by mass. Ink composition. The ink composition according to any one of claims 1 to 5, wherein the value B of the ultraviolet absorber (C) obtained by the following formula (1) is 100 or more.
Molecular weight of UV absorber (g / mol) / | SP value of UV absorber-Average SP value of polymerizable compound | = B ... Formula (1) The ink composition according to any one of claims 1 to 6, wherein the (C) ultraviolet absorber contains at least two kinds of ultraviolet absorbers. The ink composition according to any one of claims 1 to 7, wherein the photopolymerization initiator (B) contains an acylphosphine oxide-based initiator. The ink composition according to any one of claims 1 to 8, wherein the ink composition contains (D) a radical scavenger in the range of 0.5 to 5% by mass. Any of claims 1 to 6, wherein the ink composition is a clear ink having a light transmittance of 80% or more in a wavelength range of 380 to 800 nm when a film having a thickness of 30 μm is formed. The ink composition according to. 1. The ink composition is a clear ink for protecting the surface of a colored layer formed by at least one of a paint, a printing ink, an inkjet ink, and a powder toner. 10. The ink composition according to any one of 10. A method for forming a decorative body, which comprises performing inkjet printing on the surface of a colored layer formed on a base material with the ink composition according to any one of claims 1 to 11.