JP2010209199A - Photocurable ink composition, inkjet recording method, recorded matter, ink set, ink cartridge and recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photocurable ink composition which gives images excellent in rubbing resistance and a photocurable ink composition which gives images having particularly excellent curability and excellent rubbing resistance as well. <P>SOLUTION: The photocurable ink composition includes at least polymerizable compounds and a photopolymerization initiator and at least one of the polymerizable compounds is a propylene oxide-modified monomer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to an ink composition that is cured by light such as ultraviolet rays, and particularly relates to a photocurable ink composition that has excellent curability and gives an image having excellent abrasion resistance. The present invention also relates to an ink jet recording method using the photocurable ink composition and a recorded matter thereof. The present invention further relates to an ink set, an ink cartridge, and a recording apparatus provided with the photocurable ink composition.

The ink jet recording method is a printing method in which printing is performed by causing a droplet of an ink composition to fly and adhere to a recording medium such as paper. This ink jet recording method is characterized in that a high-resolution and high-quality image can be printed at high speed. The ink composition used in the ink jet recording method generally contains an aqueous solvent as a main component and contains a coloring component and a wetting agent such as glycerin for the purpose of preventing clogging.
On the other hand, papers, fabrics, or metals, plastics, or the like that do not penetrate water-based ink compositions, such as phenol, melamine, vinyl chloride, acrylic, polycarbonate, P
When printing on a recording medium such as a plate or film manufactured from a resin such as ET, PP, or PE, the ink composition is required to contain a component that allows the coloring material to be stably fixed to the recording medium. .

In response to such a requirement, a photocurable inkjet ink containing a coloring material, a photocuring agent, a polymerization initiator and the like has been disclosed (for example, see Patent Documents 1 to 3).
However, the above-described conventional photocurable ink-jet ink has room for improvement in image properties such as ink curability and abrasion resistance.

JP 2003-342499 A JP 2005-68255 A JP 2006-241218 A

An object of the present invention is to provide a photocurable ink composition that gives an image excellent in abrasion resistance,
In particular, an object of the present invention is to provide a photocurable ink composition that has an excellent curability and gives an image excellent in abrasion resistance.
Another object of the present invention is to provide an ink jet recording method using the photocurable ink composition, a recorded material, an ink set, an ink cartridge, and a recording apparatus.

The present invention is as follows.
(1) A photocurable ink composition comprising at least a polymerizable compound and a photopolymerization initiator, wherein at least one of the polymerizable compounds is a propylene oxide-modified monomer. .
(2) The photocurable ink composition as described in (1) above, wherein the propylene oxide chain contained in the propylene oxide-modified monomer has a chain length of 2 to 7.
(3) The photocurable ink composition as described in (1) or (2) above, further comprising a dendritic polymer as the polymerizable compound.
(4) The photocurable ink composition as described in any one of (1) to (3) above, further comprising allyl glycol as the polymerizable compound.
(5) The photocurable ink composition as described in any one of (1) to (4) above, further containing a coloring material.
(6) An inkjet recording method comprising forming an image using the photocurable ink composition according to any one of (1) to (5) above.
(7) A recorded matter in which an image is formed on a recording medium by the ink jet recording method described in (6) above.
(8) An ink set comprising a plurality of photocurable ink compositions, wherein the above (1) to (1)
An ink set comprising at least the photocurable ink composition according to any one of (5).
(9) An ink cartridge comprising the ink set according to (8).
(10) A recording apparatus comprising the ink cartridge according to (9).

The photocurable ink composition of the present invention has excellent curability and can form an image excellent in abrasion resistance. Further, by using a propylene oxide-modified monomer and allyl glycol in combination as a polymerizable compound contained in the photocurable ink composition, a thin film having excellent abrasion resistance can be formed.

Hereinafter, the photocurable ink composition of the present invention will be described in detail.
The photocurable ink composition of the present invention is a photocurable ink composition containing at least a polymerizable compound and a photopolymerization initiator, wherein at least one of the polymerizable compounds is a propylene oxide-modified monomer. To do.

The propylene oxide-modified monomer used in the present invention is not particularly limited as long as it is a compound having a polymerizable group and a propylene oxide-modified group. Examples of the polymerizable group include a (meth) acryloyl group, an allyl group, and a vinyl group.
In general, it is known that a polymerizable compound that is cured by a radical polymerization reaction by irradiation with an actinic ray such as ultraviolet rays tends to cause curing shrinkage or the like at the time of curing, and thus tends to have poor abrasion resistance. On the other hand, the photocurable ink composition of the present invention can form an ink film having excellent abrasion resistance on a recording medium by containing a propylene oxide-modified monomer as a polymerizable compound.

In the present invention, the number of propylene oxide chains in the propylene oxide-modified monomer is preferably 2 to 7 and preferably 2 to 4 from the viewpoint of achieving both the curability of the ink composition and the abrasion resistance of the cured image. It is more preferable. If the number of propylene oxide chains is too large, the rub resistance is improved, but the curability of the ink composition is lowered. Also, the viscosity of the ink composition increases,
There is a concern that the discharge stability becomes unstable. On the other hand, if the amount is too small, the curability of the ink composition is good, but it is difficult to obtain a desired effect in abrasion resistance.

From the viewpoint of achieving both the curability of the ink composition and the abrasion resistance of the cured image, the propylene oxide-modified monomer in the present invention is dipropylene glycol diacrylate (D
PGDA), tripropylene glycol diacrylate (TPGDA), and polypropylene glycol diacrylate (PPGDA) having 2 to 4 propylene oxide chains are preferred.

The content of the propylene oxide-modified monomer in the photocurable ink composition of the present invention is preferably 10 to 80% by mass, and more preferably 20 to 70% by mass.

Furthermore, the photocurable ink composition of the present invention preferably contains a dendritic polymer as the polymerizable compound. Dendritic polymers can be broadly classified into six structures as shown below ("dendritic macromolecules-a world of high functionality with multi-branched structures") supervised by Keigo Aoi / Masaaki Enomoto, NT Corporation・ See S).
I Dendrimer
II Linear dendritic polymer
III Dendrigraft polymer
IV Hyperbranched polymer
V star hyperbranched polymer
VI Hyper Graft Polymer

Among these, I to III have a degree of branching (DB) of 1 and have a defect-free structure, whereas IV to VI have a random branch structure that may contain defects. is doing. In particular, dendrimers can be arranged with high density and concentration of reactive functional groups on the outermost surface compared to generally used linear polymers. Expectation is high. In addition, even if the hyperbranched polymer, dendrigraft polymer or hypergraft polymer is not as large as the dendrimer, it is possible to introduce many reactive functional groups on the outermost surface, and it is excellent in curability.

Unlike conventional linear polymers and branched polymers, these dendritic polymers repeat highly branched structures in three dimensions and are highly branched. Therefore, it is possible to keep the viscosity low compared to a linear polymer having the same molecular weight.

In the method of synthesizing the dendrimer used in the present invention, Div is synthesized from the center to the outside.
Examples thereof include a rgent method and a convergent method performed from the outside toward the center.

The dendrimer, hyperbranched polymer, dendrigraft polymer and hypergraft polymer used in the present invention are preferably solid at room temperature and have a number average molecular weight in the range of 1,000 to 100,000, particularly in the range of 2000 to 50,000. Are preferably used. When it is not solid at room temperature, the maintainability of the formed image is deteriorated. In addition, when the molecular weight is lower than the above range, the fixed image becomes fragile, and when the molecular weight is higher than the above range, the viscosity of the ink becomes too high even if the addition amount is lowered, in terms of flight characteristics. It is no longer practical.

The dendrimers, hyperbranched polymers, dendrigraft polymers and hypergraft polymers used in the present invention are dendrimers, hyperbranched polymers, dendrigraft polymers and hypergraft polymers having a radically polymerizable functional group on the outermost surface. Preferably there is. By adopting a structure capable of radical polymerization on the outermost surface, the polymerization reaction proceeds rapidly.

Examples of polymers having a dendrimer structure include amidoamine dendrimers (US Pat. Nos. 4,507,466, 4,558,120, 4,568,737, 4).
, 587,329, 4,631,337, 4,694,064), phenyl ether dendrimers (US Pat. No. 5,041,516, Journal)
of American Chemistry 112 (1990, 7638-764)
7))). As for the amidoamine type dendrimer, a dendrimer having a terminal amino group and a carboxylic acid methyl ester group is available from Aldrich as "Starbur.
It is commercially available as “stTM (PAMAM)”. In addition, the terminal amino group of the amidoamine-based dendrimer can be reacted with various acrylic acid derivatives and methacrylic acid derivatives to synthesize amidoamine-based dendrimers having corresponding terminals, and then used.

Available acrylic acid and methacrylic acid derivatives include methyl, ethyl, n
-Acrylic acid or methacrylic acid alkyl esters such as butyl, t-butyl, cyclohexyl, palmityl, stearyl, etc., acrylic acid or methacrylic acid alkylamides such as acrylic amide, isopropylamide, etc. Absent.

Further, regarding the phenyl ether dendrimer, for example, the above Journal o
f American Chemistry 112 (1990, 7638-7647)
Page) describes various things. For example, 3,5-dihydroxybenzyl alcohol is used and reacted with 3,5-diphenoxybenzyl bromide to synthesize a second generation benzyl alcohol, and its OH group is converted to CBr. After converting to Br using ₄ and triphenylphosphine, similarly react with 3,5-dihydroxybenzyl alcohol to synthesize the next generation benzyl alcohol, and then repeat the above reaction to synthesize the desired dendrimer. Is described. As for the phenyl ether dendrimer, the terminal can be substituted with one having various chemical structures instead of the terminal benzyl ether bond. For example, Jo
When synthesizing the dendrimer described in urnal of American Chemistry Vol. 112, various alkyl halides can be used instead of the benzyl bromide.
A phenyl ether dendrimer having a terminal structure having a corresponding alkyl group is obtained. Other polyamine dendrimers (Macromol. Symp. 77, 21 (19
94)) and derivatives with modified end groups can be used.

As the hyperbranched polymer, for example, hyperbranched polyethylene glycol can be used. A hyperbranched polymer uses a monomer that has two or more kinds of reaction points corresponding to a branched portion and one kind of another reaction point corresponding to a connecting portion in one molecule, and the target polymer in one step. It is obtained by synthesis (Macr
omolecules, 29 (1996), 3831-3838). For example, a 3,5-dihydroxybenzoic acid derivative is an example of a monomer for a hyperbranched polymer. An example of producing a hyperbranched polymer is 1-bromo-8- (t
-Butyldiphenylsiloxy) -3,6-bis ((8 '-(t-butyldiphenylsiloxy)-) obtained from 3,6-dioxaoctane and methyl 3,5-dihydroxybenzoate
3 ', 6'-dioxaoctyl) oxy) 3,5-hydrolyzate of methyl benzoate
Poly (bis (triethylene glycol), a hyperbranched polymer, is obtained by heating methyl bis ((8'-hydroxy-3 ', 6'-dioxaoctyl) oxy) benzoate with dibutyltin diacetate in a nitrogen atmosphere. Benzoate] can be synthesized.

When 3,5-dihydroxybenzoic acid is used, the hyperbranched polymer terminal group becomes a hydroxyl group, and therefore, hyperbranched polymers having various terminal groups are synthesized by using an appropriate alkyl halide for the hydroxyl group. be able to.

The properties of monodisperse polymers or hyperbranched polymers with a dendrimer structure are governed by the chemical structure of the main chain and the chemical structure of the terminal group, but the characteristics are particularly dependent on the difference of the substituents in the terminal group and chemical structure. Are very different. Those having a polymerizable group at the terminal are particularly useful because of their reactivity, the gelation effect after photoreaction is great. A dendrimer having a polymerizable group can be obtained by chemically modifying a compound having a polymerizable group at the end of one having a basic atomic group such as an amino group, a substituted amino group, or a hydroxyl group at the end.

For example, it is synthesized by adding, for example, an isocyanate group-containing vinyl compound to a polyfunctional compound obtained by Michael addition of an active hydrogen-containing (meth) acrylate compound to an amino dendrimer. Moreover, the dendrimer which has a polymerizable group at the terminal is obtained by making (meth) acrylic acid chloride etc. react with an amino dendrimer, for example. Examples of the vinyl compound providing such a polymerizable group include compounds having an ethylenically unsaturated bond capable of radical polymerization. Examples thereof include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, and isocrotonic acid. And compounds having ethylenically unsaturated bonds capable of various radical polymerization described later, such as unsaturated carboxylic acids such as maleic acid and salts thereof.

In the present invention, the above dendrimer, hyperbranched polymer, dendrigraft polymer and hypergraft polymer may be used alone or in combination with other types of dendrimers and hyperbranched polymers.

In the photocurable ink composition of the present invention, the amount of the dendritic polymer added is preferably 5% by mass or more, more preferably 10 to 30% by mass, and still more preferably 10 to 20% by mass. If it is the said range, the suitability as a photocurable ink can be preferably maintained.
When adding a dendritic polymer, good curability can be ensured by setting the addition amount of the dendritic polymer to 5% by mass or more, and if the addition amount of the dendritic polymer is 30% by mass or less,
Problems such as viscosity, dispersion stability, and storage stability of the ink composition do not occur.

The photocurable ink composition of the present invention preferably contains allyl glycol as the polymerizable compound. It is preferable to contain a propylene oxide modified monomer and allyl glycol as the polymerizable compound. As a result, allyl glycol partially volatilizes during curing, so that a thin film having excellent abrasion resistance can be formed.
In the photocurable ink composition of the present invention, the content of allyl glycol is desirably 20 to 80% by mass, preferably 40 to 80% by mass, more preferably 40 to 75%, based on the total amount of the ink composition. It is contained by mass%, particularly preferably 40 to 65 mass%.
When allyl glycol is added, if the amount of allyl glycol added exceeds 80% by mass, curability as a photocurable ink composition may be insufficient. However, if the addition amount of allyl glycol is 20% by mass or more and 80% by mass or less, good curability can be secured, and problems such as viscosity, dispersion stability, and storage stability of the ink composition do not occur.

In addition, in the photocurable ink composition of the present invention, other polymerizable compounds other than those described above can also be used.
Such a polymerizable compound is not particularly limited, and examples thereof include monomers.
A monomer refers to a molecule that can be a structural unit of the basic structure of a polymer. Moreover, as a monomer used in this invention, there exist a monofunctional monomer, a bifunctional monomer, and a polyfunctional monomer, and all can be used. Any monomer has a PII value (Primary Irr).
(itation Index, primary skin irritation) is preferably 2 or less.

Monofunctional monomers, bifunctional monomers and polyfunctional monomers having a PII value of 2 or less that can be used in the present invention are exemplified in Table 1 below.

  In addition, the viscosity in the said table | surface is a measured value in 25 degreeC.

Moreover, an N-vinyl compound may be included as another monofunctional monomer or polyfunctional monomer. Examples of the N-vinyl compound include N-vinylformamide, N-vinylcarbazole, N-vinylacetamide, N-vinylpyrrolidone, N-vinylcaprolactam, acryloylmorpholine, and derivatives thereof, and have excellent curability. In particular, N-vinylformamide is preferable.
In addition, the photocurable ink composition of the present invention may contain an oligomer as the polymerizable compound in addition to the monomer described above.

Moreover, an initiator is added to the photocurable ink composition of the present invention. As the initiator, a radical photopolymerization initiator is preferable.
The radical photopolymerization initiator is not particularly limited, and examples thereof include benzyl dimethyl ketal, α-hydroxyalkylphenone, α-aminoalkylphenone, acylphosphine oxide, oxime ester, thioxanthone, α-dicarbonyl, anthraquinone and the like. It is done.

Also, Vice 10, 30 (made by Stauffer Chemical), Irg
acure 127, 184, 500, 651, 2959, 907, 369, 379, 7
54, 1700, 1800, 1850, 1870, 819, OXE01, Darocur
1173, TPO, ITX (Ciba Specialty Chemicals), Quanta
cure CTX (manufactured by Aceto Chemical), Kayacure DETX-S
(Nippon Kayaku Co., Ltd.), photopolymerization initiator available under the trade name ESACURE KIP150 (Lamberti) can also be used. In the photocurable ink composition of the present invention, the amount of initiator added is For example, 1 to 20% by mass,
Preferably it is 3-15 mass%.

The photocurable ink composition of the present invention may contain a polymerization accelerator.
Although it does not specifically limit as a polymerization accelerator, Darocur EHA, EDB (Ciba
Specialty Chemicals).
The actinic ray curable ink composition of the present invention preferably contains a thermal radical polymerization inhibitor. Thereby, the storage stability of the ink composition is improved. Examples of the thermal radical polymerization inhibitor include Irgastab UV-10, UV-22 (manufactured by Ciba Specialty Chemicals) and the like.

Furthermore, the actinic ray curable ink composition of the present invention can use a surfactant. For example, it is preferable to use a polyester-modified silicone or a polyether-modified silicone as a silicone-based surfactant. It is particularly preferable to use siloxane or polyester-modified polydimethylsiloxane. As a specific example, BY
K-347, BYK-348, BYK-3500, BYK-UV3510, 3530
, 3570 (manufactured by Big Chemie Japan Co., Ltd.).

Moreover, the photocurable ink composition of the present invention may contain a color material.
The coloring material used in this case may be either a dye or a pigment, but the pigment is more advantageous from the viewpoint of the durability of the printed matter.
As dyes used in the present invention, direct dyes, acid dyes, food dyes, basic dyes, reactive dyes, disperse dyes, vat dyes, soluble vat dyes, reactive disperse dyes, etc. are usually used for inkjet recording. Various dyes can be used.

As the pigment used in the present invention, inorganic pigments and organic pigments can be used without any particular limitation.
As the inorganic pigment, in addition to titanium oxide and iron oxide, carbon black produced by a known method such as a contact method, a furnace method, or a thermal method can be used. Organic pigments include azo pigments (including azo lakes _, insoluble azo pigments, condensed azo pigments, chelate azo pigments), polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazines). Pigments, thioindigo pigments, isoindolinone pigments, quinofullerone pigments, etc.), dye chelates (for example, basic dye chelates, acidic dye chelates, etc.), nitro pigments, nitroso pigments, aniline black, and the like.

Specific examples of the pigment include carbon black, No. manufactured by Mitsubishi Chemical Corporation. 2300, N
o. 900, MCF88, No. 33, no. 40, no. 45, no. 52, MA7,
MA8, MA100, no. 2200B, etc., are Raven 5750, 5250, 5000, 3500, 1255, 700, etc. manufactured by Columbia, and Rebot, manufactured by Cabot.
gal400R, 330R, 660R, Mogu L, 700, Monarch
800, 880, 900, 1000, 1100, 1300, 1400, etc.
Color Black FW1, FW2, FW2V, FW18, FW200, ColorBlack S150, S160, S170, Printe made by Degussa
x35, U, V, 140U, Special Black 6, 5, 4A, 4 and the like.

Examples of pigments used in yellow ink include C.I. I. Pigment Yellow 1, 2, 3,
12, 13, 14, 16, 17, 73, 74, 75, 83, 93, 95, 97, 98, 1
09, 110, 114, 120, 128, 129, 138, 150, 151, 154, 1
55, 180, 185, 213 and the like.
Examples of pigments used for magenta ink include C.I. I. Pigment Red 5, 7,
12, 48 (Ca), 48 (Mn), 57 (Ca), 57: 1, 112, 122, 123
168, 184, 202, 209, C.I. I. Pigment violet 19 and the like.

Further, examples of pigments used for cyan ink include C.I. I. Pigment Blue 1, 2,
3, 15: 3, 15: 4, 60, 16, and 22.
According to a preferred embodiment of the present invention, the pigment preferably has an average particle size in the range of 10 to 200 nm, more preferably about 50 to 150 nm.
The addition amount of the color material in the photocurable ink composition is preferably in the range of about 0.1 to 25% by mass, and more preferably in the range of about 0.5 to 15% by mass.

The photocurable ink composition of the present invention can also be applied to clear inks that do not contain a color material.

According to a preferred embodiment of the present invention, these pigments can be made into a photocurable ink composition as a pigment dispersion obtained by dispersing in a medium with a dispersant or a surfactant. As a preferable dispersant, a dispersant conventionally used for preparing a pigment dispersion, for example, a polymer dispersant can be used.

Moreover, when the photocurable ink composition contains a color material, the ink composition containing the color material may have a plurality for each color. For example, in addition to the basic four colors of yellow, magenta, cyan, and black, when adding the same series of dark and light colors for each color, in addition to light magenta, dark red, and cyan, in addition to magenta Light cyan,
In addition to dark blue and black, there are light gray, light black, and dark matte black.

In addition to this, surfactants, leveling additives, matting agents, polyester resins, polyurethane resins, vinyl resins, acrylic resins, rubber resins, and waxes are added to adjust film properties as necessary. I can do it.

  Further, the photocurable ink composition of the present invention may be a one-component type or a two-component type.

The photocurable ink composition of the present invention undergoes a curing reaction by light irradiation.
The irradiation light source is not particularly limited as long as it is an actinic ray, but the irradiation light source is 350 nm or more, 450
Light having a wavelength of nm or less is preferable, and ultraviolet light is preferable.
The dose of ultraviolet rays, 10 mJ / cm ² or more and 10,000 / cm ² or less, and preferably 50 mJ / cm ² or more, conducted at 6,000 mJ / cm ² or less. If it is the amount of ultraviolet irradiation within such a range, a sufficient curing reaction can be performed.

Examples of the ultraviolet irradiation include lamps such as metal halide lamps, xenon lamps, carbon arc lamps, chemical lamps, low pressure mercury lamps, and high pressure mercury lamps. For example, Fusion
A commercially available product such as an H lamp, D lamp, or V lamp manufactured by System can be used.
Further, ultraviolet irradiation can be performed by an ultraviolet light emitting semiconductor element such as an ultraviolet light emitting diode (ultraviolet LED) or an ultraviolet light emitting semiconductor laser.

The present invention can also provide an ink jet recording method in which an image is formed on a recording medium using the above-described photocurable ink composition.
As the ink jet recording method, any of the conventionally known methods can be used, and in particular, a method of ejecting droplets using vibration of a piezoelectric element (using an ink jet head that forms ink droplets by mechanical deformation of an electrostrictive element). Recording method) and a method using thermal energy, it is possible to perform excellent image recording. According to the ink jet recording method of the present invention, it is possible to form a recorded matter having excellent abrasion resistance.

The present invention also provides an ink set comprising a plurality of photocurable ink compositions, comprising at least one photocurable ink composition of the present invention described above. Can do. According to the ink set of the present invention, an image excellent in abrasion resistance can be formed.

The present invention can also provide an ink cartridge comprising the above-described photocurable ink composition of the present invention. According to the ink cartridge of the present invention, an image excellent in abrasion resistance can be formed.

The present invention can also provide a recording apparatus comprising the above-described ink cartridge of the present invention. According to the recording apparatus of the present invention, an image having excellent abrasion resistance can be formed.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.

[Examples 1 to 9, Comparative Examples 1 to 4]
(Preparation of pigment dispersion)
In Examples and Comparative Examples, pigment dispersions were prepared by the method shown below.
As a coloring material, C.I. I. Pigment Black 7 (carbon black) 15% by mass, Discol N-509 (manufactured by Dainichi Seika Kogyo Co., Ltd.) 3.5% by mass as dispersant, allyl glycol (manufactured by Nippon Emulsifier Co., Ltd.) or dipropylene glycol Diacrylate (
Example 1 only) was added to make the whole 100% by mass, and the mixture was stirred to obtain a mixture. This mixture was subjected to a dispersion treatment for 6 hours together with zirconia beads (diameter 1.5 mm) using a sand mill (manufactured by Yaskawa Seisakusho).
Thereafter, zirconia beads were separated by a separator to obtain a black pigment dispersion.

In the same manner, a pigment dispersion corresponding to each color, that is, a cyan pigment dispersion (C.I.
Pigment Blue 15: 3), magenta pigment dispersion (CI Pigment Violet)
-19), a yellow pigment dispersion (CI Pigment Yellow 213) was prepared.

(Preparation of ink composition)
In Examples and Comparative Examples, a polymerizable compound, a photopolymerization initiator, and a dispersant are mixed and completely dissolved to prepare an ink composition, and the pigment dispersion is gradually stirred into the ink solvent of the ink composition while stirring. It was dripped. After completion of the dropping, the mixture was stirred at room temperature for 1 hour to obtain an ink composition. Then, each ink composition was filtered with a 5-micrometer membrane filter, and it was set as the photocurable ink composition (Examples 1-9, Comparative Examples 1-4) shown in Table 2.
In addition, the numerical value in a table | surface shows "mass%."

  The compounds used in Table 2 are as follows.

Dipropylene glycol diacrylate (DPGDA):

Tripropylene glycol diacrylate (TPGDA):

-Polypropylene glycol diacrylate (PPGDA (n = 7)):

Tetraethylene glycol diacrylate (TeEGDA):

V # 1000: Dendritic polymer (hyperbranched polymer), manufactured by Osaka Organic Chemical Industry Co., Ltd. Irgacure 819: Photopolymerization initiator (acylphosphine oxide), Ciba
Irgacure 127 manufactured by Specialty Chemicals Co., Ltd .: Photopolymerization initiator (alkylphenone type), BYK-UV3500 manufactured by Ciba Specialty Chemicals Co., Ltd. Irgastab UV22 manufactured by BYK Japan, Inc. Agent, Ciba Specialty Chemicals Co., Ltd.
Made

(Abrasion resistance test)
Based on the method using the Gakushin type friction fastness tester of the friction resistance item of JIS standard “K 5701”, the Gakushoku type friction fastness tester manufactured by Tester Sangyo Co., Ltd. was used.
Solid printing was performed with “PX-5000” manufactured by Seiko Epson Corporation with each ultraviolet curable ink (media: WH50 (A) (manufactured by Lintec Corporation) film thickness: 10 μm). Next, the solid print was cured with an energy of about 2000 mJ / cm ² with a UV-LED irradiation device in a 400 nm wavelength region to form a cured product.
The obtained cured product was set in a Gakushin type friction fastness tester, and NPI high quality paper was used as a friction paper, and it was reciprocated 100 times with a load of 200 g. The evaluation index after the friction resistance test is shown below.
AA: The cured product is not scratched.
A: The cured product is slightly scratched, but does not adhere to the friction paper.
B: The cured product is scratched and adheres to the friction paper.

(Curability evaluation)
Each ultraviolet curable ink was solid-printed with “PX-5000” manufactured by Seiko Epson Corporation (media: Lumirror S10 (manufactured by Toray Industries, Inc.), film thickness: 10 μm). 40 solid print
Curing was evaluated by curing with a UV-LED irradiation device having an irradiation intensity of 125 mW / cm ^{2 in} the 0 nm wavelength region, and calculating the irradiation energy at that time. The evaluation index for calculating the irradiation energy is shown below.
AA: required irradiation energy 625mJ / cm ² or less A: required irradiation energy 625mJ / cm ² greater, 950 mJ / cm ² or less B: required irradiation energy 950 mJ / cm ² than

From the results of Tables 2 and 3, it can be seen that according to the photocurable ink compositions of the examples, the curability of the ink is excellent and the abrasion resistance of the obtained image is also good.
Comparative Examples 1 to 4 using tetraethylene glycol diacrylate as the polymerizable compound
However, although the acryloyl equivalent (molecular weight / number of acryloyl groups) of tetraethylene glycol diacrylate is substantially the same as that of dipropylene glycol diacrylate,
Compared to Examples 3 to 6 using dipropylene glycol diacrylate, both the curability of the ink and the abrasion resistance of the resulting image were inferior.
Moreover, since the photocurable ink compositions of Examples 2 to 9 contained allyl glycol as the polymerizable compound, the photocurable ink compositions could be made thinner than the ink composition of Example 1.

Claims (10)

A photocurable ink composition comprising at least a polymerizable compound and a photopolymerization initiator, wherein at least one of the polymerizable compounds is a propylene oxide-modified monomer. The chain length of propylene oxide contained in the propylene oxide-modified monomer is 2 to 2
The photocurable ink composition according to claim 1, wherein the photocurable ink composition is 7. The dendritic polymer is further contained as the polymerizable compound.
Or the photocurable ink composition of 2. Furthermore, allyl glycol is contained as said polymeric compound, The photocurable ink composition as described in any one of Claims 1-3 characterized by the above-mentioned. Furthermore, a color material is contained, The photocurable ink composition as described in any one of Claims 1-4 characterized by the above-mentioned. An ink jet recording method comprising forming an image using the photocurable ink composition according to claim 1. A recorded matter in which an image is formed on a recording medium by the ink jet recording method according to claim 6. An ink set comprising a plurality of photocurable ink compositions, comprising at least the photocurable ink composition according to any one of claims 1 to 5.   An ink cartridge comprising the ink set according to claim 8.   A recording apparatus comprising the ink cartridge according to claim 9.