JP2010132788A - Ink composition, method for recording, ink set, ink cartridge, and apparatus for inkjet recording - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink composition rapidly curable by an energy beam irradiation and producing an image excellent in gloss, smoothness and texture. <P>SOLUTION: The ink composition is an energy beam-curable ink composition for inkjet recording and includes a compound represented by formula (1), a dendritic oligomer, and a radical polymerization initiator. In the formula, n is an integer of 6-20, R is acryloyl or 1-3C alkyl. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to an ink composition, a recording method, an ink set, an ink cartridge, and an ink jet recording apparatus.

2. Description of the Related Art Conventionally, various ink compositions that are cured by irradiation with energy rays such as light have been developed. Such an ink composition is required to have a property of being cured quickly by energy ray irradiation and sufficiently cured.

For example, Japanese Patent Application Laid-Open No. 2006-241194 proposes an ink composition containing a radical polymerizable compound and a polymerization initiator. There is a description that the ink composition of the publication has good curability by irradiation with active energy rays.
JP 2006-241194 A

On the other hand, when the present inventor wants to obtain a printing result with an excellent texture using an energy ray curable ink composition, the ink composition only has a capability of being cured quickly and sufficiently by irradiation with energy rays. I learned that this is not enough. As a result of studies, it has been found that one of the conditions for obtaining a high-quality printing result with an energy ray curable ink composition is the smoothness of the surface of the ink composition after being cured.

One of the objects in some aspects of the present invention is to provide an ink composition that can be rapidly cured by irradiation with energy rays and that the formed image is excellent in gloss, smoothness, and texture. is there.

The ink composition according to the present invention includes:
An ink composition for ink jet recording that is cured by energy rays,
A compound represented by the following general formula (1):
A dendritic oligomer;
A radical polymerization initiator;
Containing.

(In the formula, n is an integer of 6 to 20, and R is an acryloyl group or 1 carbon atom.
Represents an alkyl group of ˜3. )
Such an ink composition can be quickly cured by irradiation with energy rays, and the formed image is excellent in gloss, smoothness and texture.

In the ink composition of the present invention,
The radical polymerization initiator may be a benzoyl-diphenyl-phosphine oxide derivative.

In the ink composition of the present invention,
The dendritic oligomer may have a weight average molecular weight of 10,000 to 60,000.

In the ink composition of the present invention,
Furthermore, a coloring material can be contained.

The recording method according to the present invention includes:
A recording method using the ink composition described above,
Preparing a recording medium;
Discharging the ink composition by an ink jet recording apparatus, and attaching the ink composition to the surface on which the image of the recording medium is recorded;
Irradiating the deposited ink composition with energy rays to cure the ink composition;
including.

In the recording method of the present invention,
The recording medium has an image recorded thereon,
In the step of attaching the ink composition, the ink composition may be attached to a surface of the recording medium on which an image is recorded.

In the recording method of the present invention,
The recording medium can be a non-absorbent medium.

The ink set according to the present invention is
The ink composition described above is provided.

The ink cartridge according to the present invention is
The above ink set is provided.

An ink jet recording apparatus according to the present invention includes:
The above-described ink cartridge is provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail.

1. Ink composition The ink composition according to the present invention is an ink composition for ink jet recording that is cured by energy rays, a compound represented by the general formula (1), a dendritic oligomer, a radical polymerization initiator, Containing.

1.1. Compound Represented by General Formula (1) The ink composition of the present embodiment contains a compound represented by the general formula (1).

The compound represented by the general formula (1) is a compound in which at least an acrylic group is bonded to a polyethylene glycol chain. One of the functions of the compound represented by the general formula (1) is a monomer in the ink composition. In the compound represented by the general formula (1), the number of repeating polyethylene glycol units (in the formula, n) is 6 or more and 20 or less. In the formula, R is an acryloyl group or an alkyl group having 1 to 3 carbon atoms. The compound represented by the general formula (1) has such a structure, thereby reducing the contact angle of the ink composition attached to the recording surface and increasing the flatness of the surface of the ink composition. Can do. Thereby, the smoothness of the surface can be enhanced when the ink composition is adhered to a recording medium or the like and cured.

The mechanism by which the above effect can be obtained by containing the compound represented by the general formula (1) in the ink composition is not very clear, but the compound represented by the general formula (1) is contained. By doing so, it is considered that the ink composition droplets have an action of suppressing at least the formation of island-like droplets on the surface of the recording medium.

In the formula, R is an acryloyl group or an alkyl group having 1 to 3 carbon atoms. Within this range, for example, the dispersibility of the compound represented by the general formula (1) in the ink composition and the curing of the ink composition The structure can be appropriately selected in order to control the properties and the affinity of the ink composition to the recording medium.

The compound represented by the general formula (1) can be obtained by chemical synthesis, but a commercially available product can also be used. As a commercial item of the compound represented by the general formula (1), for example,
Polyethylene glycol # 400 diacrylate (n = 9, R is acryloyl group) marketed by Shin-Nakamura Chemical Co., Ltd. under the trade name “A-400”, trade name “AM-
Methoxypolyethylene glycol # 400 acrylate commercially available as “90G” (
n = 9, R is a methyl group (alkyl group having 1 carbon atom)), and polyethylene glycol # 600 diacrylate (n = 14, R is an acryloyl group) commercially available under the trade name “A-600” Is mentioned.

When n in the compound represented by the general formula (1) is 5 or less, the wettability of the ink composition with respect to the recording medium may be insufficient, and when it is 21 or more, the viscosity of the ink composition increases. In some cases, the ink jet recording apparatus cannot be applied.

The content of the compound represented by the general formula (1) with respect to the total amount of the ink composition of the present embodiment is as follows:
1-30 mass% is preferable, More preferably, it is 5-15 mass%. When the content of the compound represented by the general formula (1) is less than the above range, the wettability of the ink composition with respect to the recording medium may be insufficient. When the content exceeds the above range, the viscosity of the ink composition may be low. In some cases, it becomes high and cannot be applied to the ink jet recording apparatus.

1.2. Dendritic oligomer The ink composition of this embodiment contains a dendritic oligomer.

The dendritic oligomer of this embodiment is obtained by polymerizing a polyfunctional (meth) acrylate compound and a polyvalent mercapto compound by Michael addition (β position with respect to the carbonyl group).

Michael addition of a polyvalent mercapto compound to a polyfunctional (meth) acrylate compound is such that the resulting dendritic oligomer can still undergo radical polymerization based on carbon-carbon double bonds. It is preferable that the carbon-carbon double bonds of the acrylate compound remain in the range of 0.1% to 50% as a whole.

For example, the addition ratio of the mercapto group of the polyvalent mercapto compound to the carbon-carbon double bond of the polyfunctional (meth) acrylate compound is 1/200 to 1/2 in terms of the molar ratio of the group and double bond. 1/100 to 1/3, more preferably 1/50 to 1/5, and even more preferably 1/100 to 1/3.
It is particularly preferable that the ratio is 20 to 1/8.

Moreover, it is preferable that the dendritic oligomer obtained by adding a polyvalent mercapto compound to a polyfunctional (meth) acrylate compound has a sufficient amount of functional groups for radiation polymerization. For this purpose, the molecular weight of the dendritic oligomer is 1 molecular weight per mole of carbon-carbon double bond.
It is preferably in the range of 00 to 100,000. In addition, the preferred weight average molecular weight of the dendritic oligomer of this embodiment is 1000 to 60000, more preferably 1
500 to 60,000, particularly preferably 10,000 to 60,000.

In the dendritic oligomer of this embodiment, the number of acrylate groups is preferably 2 to 20, more preferably 2 to 10, and still more preferably 2 to 6. Preferable specific examples of the polyfunctional (meth) acrylate compound include ethylene glycol di (meth)
Acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, tetramethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ethylene oxide modified trimethylol Provantri (meth) acrylate, propylene oxide modified trimethylolprovantri (meth) acrylate, trimethylolethane tri (meth) acrylate, pentaerythritol di (meth) acrylate,
Pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth)
Acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tripentaerythritol octa (meth) acrylate, tripentaerythritol hepta (meth) acrylate, caprolactone modified pentaerythritol tri (meth) acrylate, caprolactone modified Pentaerythritol tetra (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate, epichlorohydrin-modified hexahydrophthalic acid di (meth) acrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, neopentyl glycol di (meth) Acrylate, ethylene oxide modified neopentyl glycol di (meth) acrylate, pro Renoxide modified neopentyl glycol di (meth) acrylate, caprolactone modified hydroxypivalate ester neopentyl glycol di (meth) acrylate, stearic acid modified pentaerythritol di (meth) acrylate, epichlorohydrin modified phthalic acid di (meth) acrylate, poly ( Ethylene glycol tetramethylene glycol) di (meth) acrylate, poly (propylene glycol tetramethylene glycol) di (meth) acrylate, polyester (meth) acrylate, polyethylene glycol di (meth) acrylate, polyethylene glycol-polypropylene glycol-polyethylene glycol di ( (Meth) acrylate, polypropylene glycol di (meth) acrylate, epichlorohydrin modification Propylene glycol di (meth) acrylate, propylene oxide modified bisphenol A diglycidyl ether di (meth) acrylate, silicone di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, tricyclode Candimethanol di (meth) acrylate, neopentyl glycol modified trimethylolpropane di (meth) acrylate, tripropylene glycol di (meth) acrylate, ethylene oxide modified tripropylene glycol di (meth) acrylate, triglycerol di (meth) acrylate, Dipropylene glycol di (meth) acrylate, epichlorohydrin modified glycerol tri (meth) acrylate, ethylene oxide modified Glycerol tri (meth) acrylate, propylene oxide modified glycerol tri (
(Meth) acrylate, ethylene oxide modified tri (meth) acrylate phosphate, caprolactone modified trimethylolpropane tri (meth) acrylate, HPA modified trimethylolpropane tri (meth) acrylate, ethylene oxide modified trimethylolpropane tri (meth) acrylate, propylene Oxide-modified trimethylolpropane tri (
(Meth) acrylate, trimethylolpropane benzoate (meth) acrylate, tris ((meth) acryloxyethyl) isocyanurate, alkoxy-modified trimethylolpropane tri (meth) acrylate, dipentaerythritol poly (meth) acrylate,
Mention may be made of (meth) acrylic acid esters such as alkyl-modified dipentaerythritol tri (meth) acrylate and ditrimethylolpropane tetra (meth) acrylate. These compounds may be used alone or in combination of two or more.

In the dendritic oligomer of this embodiment, examples of the polyvalent mercapto compound include 1,2-dimercaptoethane, 1,3-dimercaptopropane, 1,4-dimercaptobutane, bisdimercaptoethanethiol (HS—CH _{2). CH 2 -S-CH 2 CH 2} -SH), trimethylolpropane tri (mercaptoacetate), trimethylolpropane tri (mercaptopropionate), pentaerythritol tetra (mercaptoacetate), pentaerythritol tri (mercaptoacetate), pentaerythritol Examples include erythritol tetra (mercaptopropionate), dipentaerythritol hexa (mercaptoacetate), dipentaerythritol hexa (mercaptopropionate), and the like.

In the present embodiment, when synthesizing the dendritic oligomer, a polymerization inhibitor can be added as necessary. As the polymerization inhibitor, hydroquinone compounds and phenol compounds generally used for preventing polymerization of (meth) acrylate compounds can also be used in the present invention. Specific examples thereof include, but are not limited to, hydroquinone, methoxyhydroquinone, caterol, p-tert-butylcatechol, cresol, dibutylhydroxytoluene, 2,4,6-tri-tert-butylphenol (BHT) and the like. .

Completion of the synthesis of the dendritic oligomer used in the present embodiment can be confirmed by liquid chromatography, gel filtration chromatography, or other general analytical instruments.

In the dendritic oligomer used in the present embodiment, the Michael addition reaction of the polyvalent mercapto compound to the (meth) acrylate group of the polyfunctional (meth) acrylate compound is performed using the polyfunctional (meth) acrylate compound (monomer) and the polyvalent oligomer. It can be carried out by mixing a mercapto compound and adding a basic catalyst at room temperature to 100 ° C. The reaction time is usually about 30 minutes to about 6 hours.

More specific examples of the dendritic oligomer used in the ink composition of the present embodiment include a dendritic oligomer available from Osaka Organic Chemical Industry Co., Ltd. under the trade name “STAR501”.

By including the dendritic oligomer used in the present embodiment in the ink composition, the detailed mechanism of having excellent image sharpness, color developability, and bleeding suppression effect in the printing result is not clear. However, in general, the reaction using thiol and acrylate is considered to be one of the factors that cause excellent performance to be cured with low energy and less susceptible to oxygen inhibition in radical polymerization.

The amount of the dendritic oligomer contained in the ink composition according to this embodiment is not particularly limited, but is preferably 1% by mass to 50% by mass, and more preferably 5% with respect to the ink composition.
% By mass to 30% by mass. If the content of the dendritic polymer is smaller than this range, image sharpness and color developability may not be obtained in the printing result of the ink composition.
On the other hand, if the dendritic oligomer content is larger than this range, the viscosity of the ink composition may be remarkably increased, which may cause problems in the ink jet recording method.

1.3. Radical polymerization initiator The ink composition of the present embodiment contains a radical polymerization initiator. The radical polymerization initiator can generate an active species in radical polymerization by receiving energy rays. Thereby, the radical polymerization initiator can have a function as a polymerization initiator of a functional group having radical polymerizability of the compound represented by the general formula (1) and the dendritic oligomer.

As the radical polymerization initiator that generates radicals by energy rays, those known to those skilled in the art can be used without limitation, and specifically, for example, Bruce M. et al. By Monroe et al., C
chemical Review, 93, 435 (1993), R.C. S. Davidso
n, Journal of Photochemistry and biology
A: Chemistry, 73.81 (1993); P. Faussier “P
photoinitiated Polymerization-Theory and
Applications ": Rapra Review vol. 9, Report,
Rapra Technology (1998); Tsunooka et al
. , Prog. Polym. Sci. , 21, 1 (1996). Further, F.I. D. Saeva, Topics in Current Chemistr
y, 156, 59 (1990), G.M. G. Maslak, Topics in Curr
ent Chemistry, 168, 1 (1993), H.C. B. Shuster et
al, JACS, 112, 6329 (1990), I.I. D. F. Eaton et a
l, JACS, 102, 3298 (1980) and the like, a group of compounds that undergo oxidative or reductive bond cleavage through interaction with the electronically excited state of a sensitizing dye is also known.

Preferred radical polymerization initiators include (a) aromatic ketones, (b) aromatic onium salt compounds, (c) organic peroxides, (d) hexaarylbiimidazole compounds, (e) ketoxime ester compounds, f) a borate compound, (g) an azinium compound, (h) a metallocene compound, (i) an active ester compound, (j) a compound having a carbon halogen bond,
k) Acylphosphine oxide compounds and the like.

(A) As a preferable example of aromatic ketones, “RADIATION CURING”
IN POLYMER SCIENCE AND TECHNOLOGY "J. P. FO
UASSIER J.M. F. Examples include compounds having a benzophenone skeleton or a thioxanthone skeleton described in RABEK (1993), p77-117.

Examples of preferred (a) aromatic ketones include α-thiobenzophenone compounds, benzoin ether compounds, α-substituted benzoin compounds, benzoin derivatives, aroylphosphonic acid esters, dialkoxybenzophenones, benzoin ethers, α-aminobenzophenones. And p-di (dimethylaminobenzoyl) benzene, thio-substituted aromatic ketone, acylphosphine sulfide, acylphosphine, thioxanthones, and coumarins.

(B) As aromatic onium salts, elements of Group V, VI and VII of the Periodic Table, specifically N, P, As, Sb, Bi, O, S, Se, Te, or I Aromatic onium salts are included. For example, sulfonium salts, diazonium salts (such as benzenediazonium which may have a substituent), diazonium salt resins (such as formaldehyde resin of diazodiphenylamine), N-alkoxypyridinium salts, etc., specifically 1-methoxy- A compound such as 4-phenylpyridinium tetrafluoroborate) is preferably used.

(C) “Organic peroxide” includes almost all organic compounds having one or more oxygen-oxygen bonds in the molecule. Examples thereof include 3,3′4,4′-tetra- ( t-butylperoxycarbonyl) benzophenone, 3,3′4,4′-tetra- (t-amylperoxycarbonyl) benzophenone, 3,3′4,4′-tetra- (t-hexylperoxycarbonyl) benzophenone 3,3′4,4′-tetra- (t-octylperoxycarbonyl) benzophenone, 3,3′4,4′-tetra- (cumylperoxycarbonyl) benzophenone, 3,3′4,4′- Peroxide esters such as tetra- (p-isopropylcumylperoxycarbonyl) benzophenone and di-t-butyldiperoxyisophthalate are preferred.

(D) Examples of hexaarylbiimidazole include 2,2′-bis (o-chlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-
Bromophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o, p-dichlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2, 2′-bis (o-chlorophenyl) -4,4 ′, 5,5′-tetra (m-methoxyphenyl) biimidazole, 2,2′-bis (o, o′-dichlorophenyl) -4,4 ′
, 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-nitrophenyl)-
4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-methylphenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis ( o-trifluorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole and the like.

(E) The ketoxime ester is 3-benzoyloxyiminobutan-2-one, 3
-Acetoxyiminobutan-2-one, 3-propionyloxyiminobutan-2-one, 2-acetoxyiminopentan-3-one, 2-acetoxyimino-1-phenylpropan-1-one, 2-benzoyloxyimino -1-phenylpropan-1-one, 3-p
-Toluenesulfonyloxyiminobutan-2-one, 2-ethoxycarbonyloxyimino-1-phenylpropan-1-one and the like can be mentioned.

(F) Examples of borate salts include U.S. Pat. Nos. 3,567,453 and 4,343,891.
And European Patents 109,772 and 109,773. Examples of (g) azinium salt compounds, which are other examples of energy beam polymerization initiators, include JP-A Nos. 63-138345, 63-142345, and 63-1.
Examples include compounds having an N—O bond described in JP-A-42346 and JP-A-63-143537.

Examples of (h) metallocene compounds include JP 59-152396 and JP 61-1.
No. 51197, JP-A-63-41484, JP-A-2-249, JP-A-2-4705, titanocene compounds, JP-A-1-304453, JP-A-1-152109
The iron-arene complex described in No. 1 can be mentioned.

Specific examples of the titanocene compound include di-cyclopentadienyl-Ti-di-chloride, di-cyclopentadienyl-Ti-bis-phenyl, and di-cyclopentadienyl-Ti-bis-2,3. 4,5,6-pentafluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-cyclopentadienyl-Ti- Bis-2,4,6-trifluorophen-1-yl, di-cyclopentadienyl-Ti-2,6-difluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,4 -Difluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophen-1-yl, di-methylcyclopentadienyl-Ti- -2,3,5,6-tetrafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,4-difluorophen-1-yl, bis (cyclopentadienyl) -bis (2,6-difluoro-3- (pyrid-1-yl)
Phenyl) titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3-
(Methylsulfonamido) phenyl] titanium, bis (cyclopentadienyl) bis [2,
6-difluoro-3- (N-butylbialoyl-amino) phenyl] titanium and the like.

(I) Examples of active ester compounds include nitrobenzester compounds and iminosulfonate compounds.

(J) Preferred examples of the compound having a carbon halogen bond include Vicure 10,
30 (manufactured by Stauffer Chemical), Irgacure 127, 184
, 500, 651, 2959, 907, 369, 379, 754, 1700, 1800,
1850, 819, OXE01, Darocure 1173, ITX (manufactured by Ciba Specialty Chemicals), Quanture CTX (Aceto Chemical)
al), Kayacure DETX-S (Nippon Kayaku), ESACURE KI
The compound which can be obtained by the brand name of P150 (made by Lamberti) can be mentioned.

(K) Preferred examples of acylphosphine oxide compounds include 2,4,6-
Trimethylbenzoyl-diphenyl-phosphine oxide, Darocu
re A compound available from Ciba Specialty Chemicals under the trade name TPO.

The radical polymerization initiator is preferably contained in the ink composition according to this embodiment in an amount of 1 to 20% by weight, and more preferably 3 to 15% by weight. By setting it as the said range, there exists an effect which hold | maintains sclerosis | hardenability, without reducing the mechanical strength of the composition after hardening.
As the radical polymerization initiator, one having sensitivity to irradiated energy rays can be appropriately selected and used.

1.4. Other components 1.4.1. Radical polymerizable compound The ink composition of the present embodiment can further contain a radical polymerizable compound.
One or a plurality of radically polymerizable compounds can be used for the purpose of adjusting the polymerization reaction rate, ink physical properties, cured film physical properties, and the like. Moreover, the radically polymerizable compound may be a monofunctional compound or a polyfunctional compound.

Examples of the radically polymerizable compound that can be used in the ink composition of the present embodiment include various known radically polymerizable compounds that cause a polymerization reaction with an initiation species generated from a radical initiator. Such radically polymerizable compounds include (meth) acrylates, (meth)
Examples include acrylamides, aromatic vinyls, compounds having an allyl group, and compounds having an N-vinyl group. Further, radically polymerizable compounds include vinyl esters [vinyl acetate, vinyl propionate, vinyl versatate, etc.], allyl esters [allyl acetate, etc.], halogen-containing monomers [vinylidene chloride, vinyl chloride, etc.], vinyl ethers [Methyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, methoxy vinyl ether, 2-ethylhexyl vinyl ether, methoxyethyl vinyl ether, cyclohexyl vinyl ether, chloroethyl vinyl ether, etc.], vinyl cyanide [(meth) acrylonitrile, etc.], olefins [ethylene, propylene, etc.] Etc.

1.4.2. Colorant The ink composition of the present embodiment can contain a colorant. The color material may be either a dye or a pigment. In addition, the ink composition of this embodiment can be used as a clear coat even if it does not contain the color material exemplified here.

Examples of dyes that can be used in the ink composition of the present embodiment include direct dyes, acid dyes, food dyes, basic dyes, reactive dyes, disperse dyes, vat dyes, soluble vat dyes, and reactive disperse dyes. Various dyes used for inkjet recording can be used.

Examples of the pigment that can be used in the ink composition for inkjet recording of the present embodiment include inorganic pigments and organic pigments.

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, C.I. I. Pigment Black 7, No. manufactured by Mitsubishi Chemical Corporation. 2300, no. 900, MCF88, No. 33, no. 40, N
o. 45, no. 52, MA7, MA8, MA100, no. 2200B, etc. are Columbian Raven 5750, 5250, 5000, 3500, 1255, 7
00 etc. are Regal 400R, 330R, 660R, Mogu made by Cabot.
l L, 700, Monarch 800, 880, 900, 1000, 110
0, 1300, 1400, etc. are Degussa Color Black FW1, FW2, FW2V, FW18, FW200, Color Black S150,
S160, S170, Printex 35, U, V, 140U, Speci
al Black 6, 5 and 4A, 4 and the like.

Examples of yellow pigments include C.I. I. Pigment Yellow 1, 2, 3, 12, 13, 14,
16, 17, 73, 74, 75, 83, 93, 95, 97, 98, 109, 110, 11
4, 120, 128, 129, 138, 150, 151, 154, 155, 180, 18
5, 213, and CHROMOPHTAL YELLOW LA2 (manufactured by Ciba Specialty Chemicals).

Examples of magenta pigments 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 Hostaperm
Examples include Pink E02 (manufactured by Clariant Japan Co., Ltd.).

Further, as the cyan pigment, C.I. I. Pigment Blue 1, 2, 3, 15: 3, 15
: 4, 60, 16, 22, and TGR-SD (manufactured by DIC Corporation).

When the pigment is contained in the ink composition for ink jet recording of the present embodiment, the pigment preferably has an average particle diameter in the range of 10 to 200 nm, more preferably 50 to 15.
It is about 0 nm. When the ink composition for inkjet recording of the present embodiment contains a color material, the amount of the color material added is preferably in the range of about 0.1 to 25% by mass, more preferably about 0.5 to 15% by mass. Range.

Further, when pigments are contained in the ink composition for ink jet recording of the present embodiment, these pigments and a dispersant or a surfactant can be contained. As a preferable dispersant, a dispersant conventionally used for preparing a pigment dispersion, for example, a polymer dispersant can be used. Examples of such a dispersant include SOLPERSE manufactured by Lubrizol.
13940 can be exemplified.

1.4.3. Other Additives The ink composition of the present embodiment may contain a thermal radical polymerization inhibitor. Thereby, the storage stability of the ink composition can be improved. Examples of the thermal radical polymerization inhibitor include Irgastab UV-10 and UV-22 (manufactured by Ciba Specialty Chemicals).

The ink composition of this embodiment may contain a polymerization accelerator. Although it does not specifically limit as a polymerization accelerator, Darocur EHA, EDB (made by Ciba Specialty Chemicals) etc. are mentioned.

Furthermore, the ink composition of the present embodiment can contain a surfactant. For example, a polyester-modified silicone or a polyether-modified silicone can be used as a silicone-based surfactant. Polyester-modified polydimethylsiloxane can also be used. Specific examples of surfactants include BYK-3.
47, BYK-348, BYK-UV3500, 3510, 3530, 3570 (manufactured by Big Chemie Japan Co., Ltd.).

Furthermore, the ink composition of the present embodiment can contain known and publicly used components that can be used in general inks. Such components include, for example, wetting agents, osmotic solvents, pH
Examples include regulators, preservatives, and fungicides. Furthermore, the ink composition of the present embodiment is
If necessary, a leveling additive, a matting agent, a polyester resin for adjusting film properties, a polyurethane resin, a vinyl resin, an acrylic resin, a rubber resin, and waxes can be contained.

1.5. Physical Properties of Ink Composition Since the ink composition of the present embodiment is used in an ink jet recording method, the viscosity of the ink composition is preferably 20 mPa · s or less at 25 ° C. If within this range,
By the ink jet recording apparatus described below, the ejection stability of the ink composition can be ensured in the step of ejecting the ink composition and depositing the ink composition on the recording medium.
The viscosity of the ink composition of the present embodiment can be adjusted by the blending amount of each component, and can also be adjusted by the molecular weight of the dendritic oligomer.

1.6. Energy rays Examples of energy rays for curing the ink composition of the present embodiment include ultraviolet rays, visible light, far ultraviolet rays, g rays, h rays, i rays, KrF excimer laser light, ArF excimer laser light, and X-rays. And particle beams such as electron beams and α rays.

When ultraviolet rays are used as energy rays, the amount of ultraviolet light applied to the ink composition is 10
mJ / cm ² or more and 20,000 mJ / cm ² or less, and preferably 50 mJ / c.
m ² or more and 15,000 mJ / cm ² or less.

In the case where ultraviolet rays are used as the energy rays, the irradiation with ultraviolet rays includes 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 System's H lamp, D lamp,
A commercially available product such as a V lamp, SubZero 055 manufactured by Integration, or the like can be used. Also, 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.

Irradiation of energy rays may be performed in the apparatus using an ink jet recording apparatus, or after an ink composition is attached to a recording medium by an ink jet recording apparatus that does not include the irradiation apparatus, another irradiation apparatus is used. May be used.

The ink composition according to the present embodiment described above includes a compound represented by the general formula (1),
By containing the dendritic oligomer and the radical polymerization initiator, it can be rapidly cured by irradiation with energy rays. Moreover, the image formed using the ink composition concerning this embodiment by this is excellent in glossiness, smoothness, and a texture.

2. Recording Method The recording method of the present embodiment includes a step of preparing a recording medium, a step of attaching an ink composition to a surface on which an image of the recording medium is recorded, and a step of curing the ink composition.

2.1. Step of Preparing Recording Medium The recording medium prepared in this step is not particularly limited and can be selected according to the use of the recorded matter. However, since the energy rays reach the ink composition more efficiently in the step of curing the ink composition, the recording medium is more preferably a non-ink-absorbing recording medium. As such a recording medium, for example, a plastic film not subjected to surface treatment for ink jet printing (that is, an ink absorbing layer is not formed), a substrate such as paper coated with plastic, Examples include those to which a plastic film is adhered. Examples of the plastic here include polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, and polypropylene.

Here, the ink non-absorbing recording medium refers to a recording medium having a printing surface with an ink absorption amount of 10 mL / m ² or less from the start of contact to 30 msec ^1/2 in the Bristow method. This Bristow method is the most popular method for measuring the amount of liquid absorbed in a short time, and is also adopted by the Japan Paper Pulp Technology Association (JAPAN TAPPI). For details of the test method, refer to Standard No. of “JAPAN TAPPI Paper Pulp Test Method 2000”. 51 "Paper and paperboard-Liquid absorbency test method-Bristow method".

When a recording medium on which an image is not formed is prepared in this step, an image having a good texture can be recorded by using an ink composition containing a coloring material in the subsequent steps.

Further, the recording medium prepared in this step may already have an image formed thereon.
When such a recording medium is prepared, a topcoat of an image can be formed by using an ink composition that does not contain a pigment in the subsequent steps, so that a recorded material with high texture can be obtained. The top coat formed in this case can be colorless or colored and transparent. The colored transparent top coat can be formed by adding a color material having a low background hiding property such as a dye to the ink composition.

The image on a recording medium on which an image is formed in advance can be formed by a general printing method. Among these printing methods, when the image is formed by the ink jet recording apparatus, the ink jet recording apparatus is used in the following steps, and this can be used in combination. it can.

2.2. Step of depositing ink composition on recording medium This step is performed by an ink jet recording apparatus. And an ink composition is discharged with an inkjet recording device, and an ink composition is made to adhere on a recording medium. The ink jet recording apparatus used in this embodiment is not particularly limited as long as it can record information by discharging droplets of an ink composition and attaching the droplets to a recording medium.

As a recording method of an ink jet recording apparatus, for example, a strong electric field is applied between a nozzle and an acceleration electrode placed in front of the nozzle, and ink is continuously ejected from the nozzle in the form of droplets. A method in which a print information signal is applied to a polarizing electrode for recording while flying or a method in which ink droplets are ejected in response to a print information signal without being deflected (electrostatic suction method). In addition, a system that forcibly ejects ink droplets by mechanically vibrating the nozzle with a crystal resonator, etc., a system that simultaneously applies pressure and printing information signals to ink liquid with piezoelectric elements, and ejects and records ink droplets (Piezo method), a method in which an ink liquid is heated and foamed with a microelectrode according to a print information signal, and an ink droplet is ejected and recorded (thermal jet method).

In addition, what is equipped with the mechanism which can perform an energy ray irradiation in an inkjet recording device can be used more suitably in order to harden the ink composition of this embodiment. As such an apparatus, for example, an energy beam irradiation apparatus mounted on a side surface of a carriage in the ink jet recording apparatus can be applied.

Further, when a recording medium on which an image is formed in advance is prepared in “2.1. Step of Preparing Recording Medium”, this step is applied to the surface on which the image of the recording medium is recorded. Can. In this way, a top coat can be formed on the image, and a recorded material with a high texture can be provided.

2.3. Step of Curing Ink Composition This step is performed by irradiating the ink composition attached on the recording medium in “2.2. Step of attaching the ink composition onto the recording medium” with energy rays. This step can be carried out in any manner as long as it can be irradiated with an energy ray that can activate the radical polymerization initiator. The energy ray can be selected from those already described. In addition, an ink jet recording apparatus provided with a mechanism capable of performing irradiation with energy rays as described above can be suitably applied to this step.

This step can also be performed using an external energy ray source that is separate from the ink jet recording apparatus. Furthermore, this process can also be performed by guiding an energy beam from an external energy beam source to the ink jet recording apparatus using an optical fiber or the like. As an external energy source,
For example, the format SubZero 055 (ultraviolet light) manufactured by Integration may be used.

Since the recording method of the present embodiment is performed using the above-described ink composition, the ink composition can be quickly cured by irradiating energy rays, and is excellent in gloss, smoothness, and texture. The recorded image can be easily recorded.

3. Ink Set As an ink set according to this embodiment, an ink set including at least one kind of the ink composition is exemplified.

An ink set including one or a plurality of the above ink compositions may be used, or an ink set including an ink including one or more other ink compositions may be used. Other ink compositions that can be included in the ink set include cyan, magenta, yellow, light cyan, light magenta, dark yellow, red, green, blue, orange,
Examples thereof include a color ink composition such as violet, a black ink composition, and a light black ink composition.

4). Ink Cartridge and Inkjet Recording Device As an ink cartridge according to the present embodiment, an ink cartridge provided with the above ink set is exemplified. According to this, the ink set provided with said ink composition can be conveyed easily. The ink jet recording apparatus according to this embodiment includes the above-described ink composition, ink set, or ink cartridge, and examples thereof include the ink jet recording apparatus described in the section “2. Recording method”.

5). Examples and Comparative Examples Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Table 1 shows the composition of the ink composition of each example and each comparative example.

5.1. Example Ink Composition Preparation 5.1.1. Example 1
The ink composition of Example 1 was prepared as follows.

First, model number V # obtained from Osaka Organic Chemical Co., Ltd., a radical polymerizable compound.
230 (1,6-hexanediol diacrylate) as a compound represented by the general formula (1) (n = 9, R is an acryloyl group), A-4 manufactured by Shin-Nakamura Chemical Co., Ltd.
10 parts by mass of 00 (polyethylene glycol # 400 diacrylate) as a dendritic oligomer, STAR501 (weight average molecular weight Mw = 2000) manufactured by Osaka Organic Chemical Industry Co., Ltd.
0) as 10 parts by mass, radical polymerization initiator, DAROCURE TPO (2, 4, 6
-Trimethylbenzoyl-diphenyl-phosphine oxide) (obtained from Ciba Specialty Chemicals) and 1 part by weight of IRGASTAB UV-22 obtained from Ciba Specialty Chemicals as a polymerization inhibitor It put into the glass container so that it might become. And it stirred for 30 minutes with the magnetic stirrer, and prepared the ink composition (clear ink) of Example 1. FIG.

5.1.2. Example 2
The ink composition of Example 2 was prepared as follows.

In Example 2, instead of “A-400” used in Example 1, AM-90G (methoxypolyethylene glycol # 400 acrylate), which is a compound represented by the general formula (1) (
n = 9, R is a methyl group (alkyl group having 1 carbon atom)) (obtained from Shin-Nakamura Chemical Co., Ltd.), other compositions and preparation conditions are the same, and an ink composition (clear ink) is prepared. did.

5.1.3. Example 3
The ink composition of Example 3 was prepared as follows.

In Example 3, instead of “A-400” used in Example 1, A-600 (polyethylene glycol # 600 acrylate) (n = 14, which is a compound represented by the general formula (1))
R is an acryloyl group (obtained from Shin-Nakamura Chemical Co., Ltd.), and other compositions and preparation conditions were the same to prepare an ink composition (clear ink).

5.1.4. Example 4
The ink composition of Example 4 was prepared as follows.

In the ink composition of Example 1, “DAROCURE T” which is a radical polymerization initiator is used.
Instead of “PO”, the radical polymerization initiator “IRGACURE 184” (1-hydroxy-cyclohexyl-phenyl-ketone) (obtained from Ciba Specialty Chemicals) was used, and the other compositions and preparation conditions were the same. Ink composition of Example 4 (
Clear ink) was prepared.

5.2. Preparation of Comparative Ink Composition 5.2.1. Comparative Example 1
The ink composition of Comparative Example 1 was prepared as follows.

In the ink composition of Example 1, instead of “A-400”, “V # 230” (1,6-hexanediol diacrylate) which is a general radical polymerizable compound (obtained from Osaka Organic Industry Co., Ltd.) The ink composition (clear ink) of Comparative Example 1 was prepared with the same composition and other preparation conditions.

5.2.2. Comparative Example 2
The ink composition of Comparative Example 2 was prepared as follows.

In the ink composition of Example 1, instead of “A-400”, the compound “A-1000” (polyethylene glycol # 1000 diacrylate) in which n is 23 and R is an acryloyl group in the general formula (1) (Osaka) The ink composition (clear ink) of Comparative Example 2 was prepared using the same composition and other preparation conditions.

5.3. Evaluation Method An ink composition was filled in an ink cartridge of an ink jet printer PX-G920 manufactured by Seiko Epson Corporation for each of Examples and Comparative Examples. For each example
A square solid pattern of 10 cm × 10 cm was printed in high-definition mode on OK top coat paper (manufactured by Oji Paper Co., Ltd.). The film thickness of the solid pattern composition was 10 μm. For all the examples, after printing, an ultraviolet irradiator (Subnet manufactured by Integration Co., Ltd.)
The printed part was cured by irradiating with ultraviolet light using Zero 055).

Then, the gloss and smoothness of the cured printed part were visually evaluated. The texture of the printed material was also evaluated by touching the finger. Each evaluation is carried out by 10 persons skilled in the art. Among applicable contractors, 7 or more are judged to be acceptable, 3 to 6 or less are judged to be acceptable, and 8 or more are acceptable. The case where it was judged as impossible was set as x, and the evaluation results are shown in Table 1.

5.4. Evaluation Results As shown in Table 1, the ink compositions of each Example were excellent in curability and excellent in gloss, smoothness, and texture. In contrast, the ink compositions of the comparative examples lacking the compound represented by the general formula (1) were insufficient in gloss, smoothness, and texture.

The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the present invention includes substantially the same configuration (for example, a configuration having the same function, method, and result, or a configuration having the same purpose and effect) as the configuration described in the embodiment. In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that achieves the same effect as the configuration described in the embodiment or a configuration that can achieve the same object. In addition, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

Claims (10)

An ink composition for ink jet recording that is cured by energy rays,
A compound represented by the following general formula (1):
A dendritic oligomer;
A radical polymerization initiator;
An ink composition comprising:

(In the formula, n is an integer of 6 to 20, and R is an acryloyl group or 1 carbon atom.
Represents an alkyl group of ˜3. ) In claim 1,
The ink composition, wherein the radical polymerization initiator is a benzoyl-diphenyl-phosphine oxide derivative. In claim 1 or claim 2,
The ink composition according to claim 1, wherein the dendritic oligomer has a weight average molecular weight of 10,000 to 60,000. In any one of Claims 1 to 3,
Furthermore, an ink composition containing a color material. A recording method using the ink composition according to any one of claims 1 to 4,
Preparing a recording medium;
Discharging the ink composition by an ink jet recording apparatus, and attaching the ink composition to the surface on which the image of the recording medium is recorded;
Irradiating the deposited ink composition with energy rays to cure the ink composition;
Including a recording method. In claim 5,
The recording medium has an image recorded thereon,
The recording method, wherein, in the step of attaching the ink composition, the ink composition is attached to a surface of the recording medium on which an image is recorded. In claim 5 or claim 6,
The recording method, wherein the recording medium is a non-absorbable medium.   An ink set comprising the ink composition according to any one of claims 1 to 4.   An ink cartridge comprising the ink set according to claim 7.   An ink jet recording apparatus comprising the ink cartridge according to claim 8.