JP2003089261A - Ink jet recording method, ink precursor, recording medium and recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording method with advantages such as superb ink discharge performance, sharp image quality and high image shelf stability after printing, a precursor composed of an ink composition and a reaction liquid, used in the recording method, a recording medium printed by the recording method and a recording device used in the recording method. SOLUTION: In the ink jet recording method of a radiation-curing and reaction type, by which an ink image is formed in a recording medium by means of a recording head with a plurality of nozzles which enable ink droplets to be selectively discharged under control, right before the ink droplets are discharged, at least one reaction liquid containing a photopolymerization initiator is added to the ink composition containing a coloring agent and a photopolymerizable monomer or an oligomer and the discharge of the mixture is carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording method capable of reproducing a high-definition image on any recording medium and having good image storability, and an ink precursor comprising an ink composition used in the recording method and a reaction liquid. The present invention relates to a recording medium printed by the recording method and a recording device used in the recording method.

[0002]

2. Description of the Related Art Conventionally, a water-soluble liquid ink composition has been widely used as an ink composition for ink jet recording.

Further, Japanese Patent Laid-Open No. 56-93776 discloses an ultraviolet curable resin type ink composition having good adhesion to a metal surface, and further, as an ink for ink jet recording which is cured by irradiation with ultraviolet rays, Inks using the epoxy-modified acrylic resin and urethane-modified acrylic resin described in U.S. Pat. No. 4,228,438 as a binder and using a pigment having a particle diameter of 5 .mu.m or less as a coloring component, or JP-A-58-32674. There are inks using a cationically polymerizable epoxy resin as a binder described in JP-A No. 5-186725 and water-soluble or water-insoluble dyes described in JP-A-5-186725 for easy printing on plain paper and recycled paper. What you have done is listed.

On the other hand, as an image forming method on a plastic substrate, as described in JP-A-52-142516, a method using a sublimable dye in an ultraviolet curable resin is known. JP-A-9-183927 describes an ultraviolet-curable resin composition coated by an inkjet recording method. Japanese Unexamined Patent Publication No. 9-165540 discloses a water-based ink containing a pigment and an ultraviolet curable resin that eliminates nozzle clogging.

Further, a hot-melt type ink composition made of a wax or the like which is solid at room temperature is used to liquefy by heating or the like, to be jetted by applying some energy, to be cooled and solidified while adhering to a recording medium and recording. A hot melt type ink jet recording method for forming dots has been proposed.
Since this ink is solid at room temperature, it solidifies immediately after adhesion and does not "bleed", and it has the advantage that various recording media such as Japanese paper, drawing paper, and postcards can be used without pretreatment. U.S. Pat. Nos. 4,391,369 and 4,484,948 describe ink compositions that provide good print quality regardless of paper quality.

When the above-mentioned water-based ink is used for printing, it is difficult to print on a recording medium having no ink absorption, and a large-sized ink drying device is required even when using special paper. Further, due to the problem of bleeding, high-definition printing is difficult and the resolution is limited, so that the application is limited.

The method in which the recording liquid is simply cured with light such as ultraviolet rays has a limited curing rate, and high-definition printing is difficult due to the problem of bleeding, and its resolution is limited, so its application is limited. In addition, the image storability was poor.

Since the ink jet recording method using an organic pigment as a colorant has many advantages over the ink jet recording method using a dye, particularly in terms of weather resistance, OA
Equipment, general household printers, facsimiles, office printers, indoor / outdoor posters, large signboards, cars,
It is expected to be applied to glass, elevators, wall and building decorations, and even printing on cloth.

When an organic pigment is used as a colorant in an ink jet ink composition, it has a drawback that it is easily separated in a liquid. The sedimentation of particles dispersed in the liquid is
As is well known, it changes depending on the particle size of the particles, the viscosity of the dispersion medium and the sedimentation time, and the higher the viscosity of the dispersion medium, the less likely it is to sediment. On the other hand, when printing with an inkjet printer, a lower viscosity of the ink is advantageous for higher speed and higher density and is suitable for high reliability printing, and both have a contradictory relationship.

High-speed printing is possible with hot-melt type inks using wax, but not only the printed dots become thick and the image quality deteriorates, but also the abrasion resistance of the image is extremely low and the reliability after printing is high. Was hard to get.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet recording method excellent in ink ejection property, image quality and image storability after printing, an ink composition used in the recording method and a reaction liquid. To provide a precursor, a recording medium printed by the recording method, and a recording device used for the recording method.

[0012]

The above object of the present invention can be achieved by the following means.

1. In a radiation curing reaction type inkjet recording method in which an ink image is formed on a recording medium by a recording head having a plurality of nozzles capable of selectively controlling ink droplet ejection, a coloring agent and a photopolymerizable monomer or oligomer are contained immediately before ejection. An ink jet recording method, comprising: mixing at least one reaction liquid containing a photopolymerization initiator with the ink composition, and then discharging the mixture.

2. In a radiation curing reaction type inkjet recording method of forming an ink image on a recording medium by a recording head having a plurality of nozzles capable of selectively controlling ejection of ink droplets, an ink containing a colorant and a photopolymerization initiator immediately before ejection. An inkjet recording method, which comprises mixing at least one reaction liquid containing a photopolymerizable monomer or oligomer with the composition and then discharging the mixture.

3. 3. The inkjet recording method as described in 1 or 2 above, wherein the colorant is a pigment.

4. 1 to 3 above, wherein the photopolymerizable monomer or oligomer is monofunctional or bifunctional.
5. The inkjet recording method according to any one of 1.

5. The curing reaction is carried out by UV irradiation, and the UV irradiation amount is 100 to 10,000 mJ / cm ^2.
5. The inkjet recording method described in any one of 1 to 4 above.

6. 6. The ink jet recording method according to any one of 1 to 5 above, wherein the ink composition and at least one reaction liquid are heated and mixed immediately before ejection and then ejected.

7. The ink jet recording method as described in 6 above, which comprises heating to 7.40 to 100.degree.

8. The viscosity of the ink prepared by mixing the ink composition and the reaction liquid is 60 to 10,000 m at 25 ° C.
Pa · s and 0.1 to 25 mPa · at 40 to 100 ° C
and an ink precursor comprising an ink composition and a reaction liquid.

9. A recording medium printed by the inkjet recording method according to any one of 1 to 7 above.

10. 10. The recording medium as described in 9 above, wherein the recording medium is non-ink absorbing.

11. A recording apparatus used in the inkjet recording method described in any one of 1 to 7 above.

The present invention will be described in detail below. As a result of earnest research, the present inventor has conducted a radiation curing reaction type inkjet recording method in which an ink image is formed on a recording medium by a recording head having a plurality of nozzles capable of selectively controlling ink droplet ejection. After mixing at least one reaction liquid containing a photopolymerization initiator with an ink composition containing a colorant and a photopolymerizable monomer or oligomer, or (2) containing a colorant and a photopolymerization initiator By mixing at least one reaction liquid containing a photopolymerizable monomer or oligomer with an ink composition and then ejecting the mixture, an ink jet recording method excellent in ink ejection property, image quality, and image storability after printing is obtained. It was found that it can be obtained.

In order to further bring out the effect of the present invention, the colorant is a pigment, the photopolymerizable monomer or oligomer is monofunctional or bifunctional, and the curing reaction is carried out by ultraviolet irradiation. UV irradiation dose is 100 ~
It is preferably 10,000 mJ / cm ^{2, and} it is preferable that the ink composition and at least one reaction liquid are heated immediately before ejection, preferably heated to 40 to 100 ° C. and mixed, and then ejected. The viscosity of the ink composition and the reaction liquid after mixing is 60 to 10,000 mPa · s at 25 ° C., 4
It is preferably 0.1 to 20 mPa · s at 0 to 100 ° C., and the recording medium is non-ink absorptive.

Next, the photopolymerizable monomer, oligomer and photopolymerization initiator used in the present invention will be described in detail.

[Photopolymerizable Monomer, Oligomer, Photopolymerization Initiator] As the photopolymerizable monomer and oligomer, there are a radical polymerizable monomer, an oligomer, and a cationic polymerizable monomer, an oligomer. The amount of addition is preferably 30 to 97% by mass, and more preferably 50 to 95% by mass in the liquid after mixing with the ink composition and the reaction liquid. Further, the addition amount of the photopolymerization initiator is the liquid after mixing the ink composition and the reaction liquid,
1 to 10 mass% is preferable, and 1 to 5 mass% is more preferable.

(Radical polymerizable monomer, oligomer,
The photopolymerization initiator) radical-polymerizable monomer or oligomer is a compound having a radical-polymerizable ethylenically unsaturated bond, and is a monomer or oligomer having at least one radical-polymerizable ethylenically unsaturated bond in the molecule. . For example, JP-A-7-159983, JP-B-7-31399, JP-A-8-224982 and JP-A-8-24998.
No. 863 and No. 9-134011 are photocurable materials using the photopolymerizable composition. Only one type of radically polymerizable monomer or oligomer may be used,
In addition, two or more kinds may be used in combination at an arbitrary ratio in order to improve target characteristics.

Examples of the radically polymerizable compound having an ethylenically unsaturated bond include acrylic acid, methacrylic acid,
Unsaturated carboxylic acids such as itaconic acid, crotonic acid, isocrotonic acid, maleic acid and their salts, esters, urethanes, amides and anhydrides, acrylonitrile, styrene
Further, radical polymerizable compounds such as various unsaturated polyesters, unsaturated polyethers, unsaturated polyamides and unsaturated urethanes can be mentioned. Specifically, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, butoxyethyl acrylate, carbitol acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, benzyl acrylate, bis (4-acryloxypolyethoxyphenyl) propane,
Neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, pentaerythritol triacrylate. , Pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, oligoester acrylate, acrylic acid derivatives such as N-methylol acrylamide, diacetone acrylamide, epoxy acrylate, methyl methacrylate, n- Butylme Acrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, allyl methacrylate, glycidyl methacrylate, benzyl methacrylate, dimethylaminomethyl methacrylate, 1,
6-hexanediol dimethacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, trimethylolethane trimethacrylate, trimethylolpropane trimethacrylate, 2,2-bis (4-methacryloxy) Methacryl derivatives such as polyethoxyphenyl) propane, other, allyl glycidyl ether, diallyl phthalate, derivatives of allyl compounds such as triallyl trimellitate, more specifically, Shinzo Yamashita, "Crosslinking agent handbook", (1981 Taiseisha); Kiyomi Kato, "UV / EB curing handbook (raw materials)" (1985, Kobunshi Kogyokai); Radtech Research Group, "UV / EB" Application of technology and the market ", 79
Page, (1989, CMC); Eiichiro Takiyama,
Commercially available products described in "Polyester Resin Handbook" (1988, Nikkan Kogyo Shimbun) and the like, or radically polymerizable or crosslinkable monomers and oligomers known in the art can be used.

In the present invention, the radically polymerizable monomer or oligomer preferably has one monofunctional or two bifunctional radically polymerizable ethylenic unsaturated bond. If it is trifunctional or higher, the stability of the ink composition or the reaction liquid cannot be obtained, and it becomes unstable especially when heated.

As a photopolymerization initiator for radically polymerizable photomonomers or oligomers, Japanese Patent Publication No. 59-1281,
61-9621, JP-A-60-60104 and the like, triazine derivatives described in JP-A-59-1504, JP-A-59-1504
Organic peroxides described in 1-243807, JP-B-43
-23684, 44-6413, 44-641
3, 47-1604, and U.S. Pat. No. 3,567,4.
Diazonium compounds described in No. 53, US Pat. No. 2,8
No. 48,328, No. 2,852,379, No. 2,
Organic azide compounds described in 940,853, Japanese Examined Patent Publication No. Sho 3
6-22062, 37-13109, 38-1
8015, 45-9610 and the like, ortho-quinone diazides, JP-B-55-39162, JP-A-5-
9-14023, etc. and "Macromolecules (Mac
various types of onium compounds described in Vol.
Azo compounds described in JP-A 9-142205, JP-A 1-5
4440, European Patent No. 109,851, European Patent No. 126,712, etc., "Journal of Imaging Science" (J. Image. Sc.
i. ) ”, Volume 30, p. 174 (1986), metal allene complexes, Japanese Patent Application Nos. 4-56831, 4-8.
(Oxo) sulfonium organoboron complex described in Japanese Patent No. 9535, titanocenes described in JP-A No. 61-151197, “Coordination Chemistry Review”.
Review, "84, 85-277 (1.
1988) and transition metal complexes containing a transition metal such as ruthenium described in JP-A-2-182701, JP-A-3.
No. 2,209,477, 2,4,5-triarylimidazole dimer, carbon tetrabromide and JP-A-59-1073.
The organic halogen compounds described in No. 44 and the like can be mentioned. These polymerization initiators are used in an amount of 0.01 to 1 with respect to 100 parts by mass of a compound having a radically polymerizable ethylenic unsaturated bond.
It is preferably contained in the range of 0 parts by mass.

(Cationically polymerizable monomer, oligomer,
Photopolymerization initiator) As the photopolymerizable monomers and oligomers, cationic polymerizable monomers and oligomers are known, and recently, cationic polymerization type photopolymerizable monomers sensitized in the long wavelength region above visible light. The oligomers are also disclosed in, for example, JP-A-6-43633 and JP-A-8-324137. Examples of the epoxy-type UV-curable prepolymers and monomers that are polymerized by cationic polymerization include prepolymers containing two or more epoxy groups in one molecule. Examples of such prepolymers include alicyclic polyepoxides, polyglycidyl esters of polybasic acids, polyglycidyl ethers of polyhydric alcohols, polyglycidyl ethers of polyoxyalkylene glycols, and polyglycidyl aromatic polyols. Examples thereof include ethers, hydrogenated compounds of polyglycidyl ethers of aromatic polyols, urethane polyepoxy compounds and epoxidized polybutadienes. These prepolymers may be used alone or in a mixture of two or more.

Other examples of cationically polymerizable monomers and oligomers include the following (1) styrene derivatives and (2)
Examples thereof include vinylnaphthalene derivatives, (3) vinyl ethers and (4) N-vinyl compounds.

(1) Styrene derivative For example, styrene, p-methylstyrene, p-methoxystyrene, β-methylstyrene, p-methyl-β-methylstyrene, α-methylstyrene, p-methoxy-β-.
Methylstyrene etc. (2) Vinylnaphthalene derivative, for example, 1-vinylnaphthalene, α-methyl-1-vinylnaphthalene, β-methyl-1-vinylnaphthalene, 4
-Methyl-1-vinylnaphthalene, 4-methoxy-1-
(3) Vinyl ethers such as vinyl naphthalene, for example, isobutyl vinyl ether, ethyl vinyl ether, phenyl vinyl ether, p-methylphenyl vinyl ether, p-methoxyphenyl vinyl ether,
(4) N-vinyl compounds such as α-methylphenyl vinyl ether, β-methyl isobutyl vinyl ether, β-chloroisobutyl vinyl ether, for example, N-vinylcarbazole, N-vinylpyrrolidone, N-vinylindole, N-vinylpyrrole, N-
Vinylphenothiazine, N-vinylacetanilide, N
-Vinylethylacetamide, N-vinylsuccinimide, N-vinylphthalimide, N-vinylcaprolactam, N-vinylimidazole and the like.

Examples of the polymerization initiator for the cationically polymerizable monomer or oligomer include aromatic onium salts. As the aromatic onium salt, a salt of a Group Va element of the periodic table, for example, a phosphonium salt (eg, triphenylphenacylphosphonium hexafluorophosphate, etc.), VI
Salts of Group a elements, such as sulfonium salts (eg, triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluorophosphate, tris (4-thiomethoxyphenyl) hexafluorophosphate), sulfonium and triphenylsulfonium hexisafluoroantimonate. Etc.) and salts of Group VIIa elements, for example iodonium salts (eg diphenyliodonium chloride etc.). The use of such an aromatic onium salt as a polymerization initiator for an epoxy type cationically polymerizable monomer or oligomer is disclosed in US Pat.
No. 8,401, No. 4,069,055, No. 4,1
01,513 and 4,161,478.

Preferred examples of the cationically polymerizable monomer or oligomer polymerization initiator include sulfonium salts of Group VIa elements. Among them, from the viewpoint of ultraviolet curability and storage stability of the ultraviolet curable composition, triarylsulfonium hexafluoroantimonate is preferable. In addition, Photopolymer Handbook (Photopolymer Conversation Edition, published by Industrial Research Society, 1989), 39-5
The photopolymerization initiator described on page 6, JP-A-64-13142
It is possible to use the compounds described in JP-A-2-4804.

In order to print a high-definition image without bleeding on any recording medium, it is desired that the viscosity of the ink when the ink lands on the recording medium is high. In particular, when the colorant is a pigment, it is desired that the viscosity of the ink is high in order to obtain an ink having good dispersion stability in which the pigment does not easily sediment.

On the other hand, when performing printing with an ink jet printer, a lower viscosity of the ink ejected from the recording head is advantageous for higher speed and higher density, and is suitable for high speed and high definition printing. There is.

In the ink jet recording method of the present invention, it is preferable to heat and mix the ink composition as an ink precursor and at least one reaction liquid immediately before discharging, and then discharging, and heating is more preferably 40 to 100 ° C. . The viscosity of the ink after mixing at least one reaction liquid with the ink composition is 60 to 10,000 mPa · s at 25 ° C.
It is preferable to use an ink composition and a reaction liquid which have a s of 0.1 to 25 mPa · s at 40 to 100 ° C.

If the viscosity is lower than 60 mPa.s at 25.degree. C., bleeding may occur at the time of landing.
When it exceeds 25 mPa · s, stable ejection cannot be performed. When printing on a non-ink absorbing recording medium, the problem of bleeding becomes significant. Viscosity is a rotational viscometer,
For example, it can be measured with an EDL model manufactured by Tokimec.

The non-ink absorptive recording medium is a recording medium having no ink absorptivity, a recording medium having a low ink absorptivity, or a surface layer (printing layer) made of a material having no ink absorptivity or a material having a low ink absorptivity. The material having no ink absorption property, the material having low ink absorption property, or the non-ink absorption material is, for example, various plastics or metals. A normal ink jet recording medium has a swelling type or void type ink absorbing layer as a surface layer, but in the present invention, since the ink is cured immediately after landing, a non-ink absorbing recording medium can be used.

[Coloring Agent] The coloring agent used in the present invention is preferably a pigment having excellent weather resistance, but any known coloring agent such as a water-soluble dye and an oil-soluble dye can be used.

The pigment preferably used in the present invention will be described. In the present invention, the color developability (color density per added concentration) is not always high, and since it is difficult to produce a uniform fine particle dispersion, there is a phenomenon in which the viscosity increases when the concentration is high, and it has been practically used as an inkjet ink. Pigments which have not been used can be used. In the present invention, for example, the following organic or inorganic pigments described in the color index can be used.

As the red or magenta pigment, Pig
ment Red 3, 5, 19, 22, 31, 38,
43, 48: 1, 48: 2, 48: 3, 48: 4, 4
8: 5, 49: 1, 53: 1, 57: 1, 57: 2, 5
8: 4, 63: 1, 81, 81: 1, 81: 2, 81:
3, 81: 4, 88, 104, 108, 112, 12
2, 123, 144, 146, 149, 166, 16
8, 169, 170, 177, 178, 179, 18
4, 185, 208, 216, 226, 257, Pig
ment Violet 3, 19, 23, 29, 3
0, 37, 50, 88, Pigment Orange
13, 16, 20, 36, as blue or cyan pigments, Pigment Blue 1, 15, 15: 1,
15: 2, 15: 3, 15: 4, 15: 6, 16, 17
-1, 22, 27, 28, 29, 36, 60, and as the green pigment, Pigment Green 7, 26, 3
6, 50, as a yellow pigment, Pigment Yell
ow 1, 3, 12, 13, 14, 17, 34, 35,
37, 55, 74, 81, 83, 93, 94, 95, 9
7, 108, 109, 110, 137, 138, 13
9,153,154,155,157,166,16
7, 168, 180, 185, 193, and as the black pigment, Pigment Black 7, 28, 26 or the like can be used according to the purpose.

The specific product names are, for example, Chromo Fine Yellow 2080, 5900, 5930, A.
F-1300, 2700L, Chromo Fine Orange
3700L, 6730, chromofine scarlet
6750, Chromo Fine Magenta 6880, 688
6, 6891N, 6790, 6887, Chromo Fine Violet RE, Chromo Fine Red 682
0, 6830, Chromo Fine Blue HS-3, 51
87, 5108, 5197, 5085N, SR-502
0, 5026, 5050, 4920, 4927, 493
7, 4824, 4933GN-EP, 4940, 497.
3, 5205, 5208, 5214, 5221, 500
0P, Chromo Fine Green 2GN, 2GO, 2G
-550D, 5310, 5370, 6830, Chromo Fine Black A-1103, Seika Fast Yellow 10GH, A-3, 2035, 2054, 2200,
2270, 2300, 2400 (B), 2500, 26
00, ZAY-260, 2700 (B), 2770, Seika Fast Red 8040, C405 (F), CA.
120, LR-116, 1531B, 8060R, 15
47, ZAW-262, 1537B, GY, 4R-40
16, 3820, 3891, ZA-215, Seika Fast Carmine 6B1476T-7, 1483LT, 3
840, 3870, Seika Fast Bordeaux 10B-
430, Seika Light Rose R40, Seika Light Violet B800, 7805, Seika Fast Maroon 460N, Seika Fast Orange 900, 2
900, Seika Light Blue C718, A612, Cyanine Blue 4933M, 4933GN-EP, 49
40, 4973 (Dainichi Seika Kogyo), KET Yell
ow 401, 402, 403, 404, 405, 40
6, 416, 424, KET Orange 501,
KET Red 301, 302, 303, 304, 3
05, 306, 307, 308, 309, 310, 33
6, 337, 338, 346, KET Blue 10
1, 102, 103, 104, 105, 106, 11
1, 118, 124, KET Green 201 (manufactured by Dainippon Ink and Chemicals), Colortex Yellow
301, 314, 315, 316, P-624, 31
4, U10GN, U3GN, UNNN, UA-414, U
263, Finecol Yellow T-13, T
-05, Pigment Yellow 1705, C
colortex Orange 202, Color
ex Red 101, 103, 115, 116, D3
B, P-625, 102, H-1024, 105C, U
FN, UCN, UBN, U3BN, URN, UGN, U
G276, U456, U457, 105C, USN, C
colortex Maroon 601, Color
ex Brown B610N, Colortex V
iolet600, Pigment Red 122,
Colortex Blue 516, 517, 51
8, 519, A818, P-908, 510, Colo
rtex Green 402, 403, Color
ex Black 702, U905 (made by Sanyo dye),
Lionol Yellow 1405G, Liono
l Blue FG7330, FG7350, FG74
00G, FG7405G, ES, ESP-S (manufactured by Toyo Ink), Toner Magenta E02, Per
manent Rubin F6B, Toner Yel
low HG, Permanent Yellow G
G-02, Hostapeam Blue B2G (manufactured by Hoechst Industry), carbon black # 2600,
# 2400, # 2350, # 2200, # 1000, #
990, # 980, # 970, # 960, # 950, #
850, MCF88, # 750, # 650, MA60
0, MA7, MA8, MA11, MA100, MA10
0R, MA77, # 52, # 50, # 47, # 45, #
45L, # 40, # 33, # 32, # 30, # 25, #
20, # 10, # 5, # 44, CF9 (manufactured by Mitsubishi Chemical) and the like.

It is also possible to use a dispersion liquid in which the pigment is dispersed in water or a solvent at a high concentration in advance. For example, MICRO
PIGMO WMBK-5, WMBE-5, WMRD-
5, WMYW-5, AMBK-2, AMYW-2, AM
BE-4 (manufactured by Orient Chemical Co., Ltd.) and the like can be mentioned.

An appropriate amount of the pigment added is 1 to 20 parts by mass with respect to 100 parts in total of the ink composition and the reaction liquid. If it is less than 1 part by mass, the image quality is deteriorated, and if it is more than 20 parts by mass, the ink viscosity characteristics are adversely affected. Also, 2 for color adjustment, etc.
Coloring agents of more than one kind can be used by appropriately mixing them.

In order to further develop the functionality of the ink composition of the present invention, various sensitizers, light stabilizers, surface treatment agents, surfactants, viscosity reducing agents, antioxidants, antiaging agents, crosslinkers. Accelerators, polymerization inhibitors, plasticizers, preservatives, pH adjusters, defoamers, humectants, dispersants and the like can be mixed.

(Curing) In the present invention, after the image is formed on the recording medium, the image is rapidly cured. Examples of the curing means include an ultraviolet (UV) irradiation lamp, an electron beam, heat and the like. Heat is generated in the UV irradiation lamp,
Since the recording medium may be deformed, it is desirable to provide a cooling mechanism such as a cold mirror, a cold filter, and work cooling. Types of lamps include high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halides, and the like. The ultra-high pressure mercury lamp is a point light source, but the DeepUV type, which has a high light utilization efficiency in combination with an optical system, can irradiate in a short wavelength region. The metal halide has a wide wavelength range and is effective for coloring. Pb,
A halide of a metal such as Sn or Fe is used and can be selected according to the absorption spectrum of the photopolymerization initiator. Any lamp that is effective for curing can be used without particular limitation.

There are many books on ultraviolet curing technology, such as "UV / EV Curing Technology" Comprehensive Technology Center (1982) by Minoru Imoto.

In the ink jet recording method of the present invention, the curing reaction is carried out by irradiation with ultraviolet rays, and the irradiation amount of ultraviolet rays is preferably 100 to 10,000 mJ / cm ² .

The recording apparatus used in the ink jet recording method of the present invention is a conventional ink jet recording apparatus in which the radiation irradiation member such as ultraviolet rays, the ink composition and the reaction liquid are mixed, the temperature is adjusted, and the liquid is supplied to the recording head. Have members.

[0053]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto.

Example 1 [Production of Ink Precursor Set] By a known production method,
The ink precursor set (ink composition, reaction liquid) of the present invention having the composition shown in Tables 2 and 3 using the compound shown in Table 1 1
~ 4 and comparative ink precursor sets AC were made.

[0055]

[Table 1]

[0056]

[Table 2]

[0057]

[Table 3]

[Evaluation] (Viscosity) With respect to the ink precursor sets 1 to 4, the viscosities of the liquids immediately after mixing the respective ink compositions and the reaction liquids at 25 ° C. and 60 ° C. were measured by a rotational viscometer (ED manufactured by Tokimec ED).
L model). The results are shown in Table 2.

(Image formation) A large format ink jet printer "IGUAZU 1044SD" manufactured by Konica Corporation was improved, and a tank for mixing two or more kinds of liquids was provided immediately before a liquid supply line to a recording head. The temperature of the liquid supply line can be adjusted (60 ° C.).

Next, as shown in Tables 4 and 5, an image was formed (text, image pattern with text, solid image) on a recording medium using a liquid in which each ink composition and the reaction liquid were mixed.

After the image formation, 1,000 mJ / c was obtained by using a metal halide type irradiation lamp having a wavelength of 365 nm.
UV irradiation of m ² was performed.

Characteristic quality, color mixing (bleeding), and image storability were evaluated as follows for the sample irradiated with ultraviolet rays. The results are shown in Tables 4 and 5.

(Character quality) K (black) density 1.83
An 8-point character was printed with, and the shape of the character and the shape of 1 dot for each color were enlarged with a magnifying glass, and evaluated according to the following criteria.

◎ ・ ・ ・ No shading, dot shape is a perfect circle ○ ・ ・ ・ Slight shading is visible, dot shape is a perfect circle △ ・ ・ ・ Rackiness is visible, dot shape is slightly disturbed × ・ ・ ・ Rackiness Outputs an image pattern in which 8-point characters with a K (black) density of 1.83 are arranged on a solid image with a M (magenta) density of 1.53, which looks bad and has a bad dot shape (blurring), and 1 dot for each color. Then, the quality after 10 minutes was enlarged with a magnifying glass and visually evaluated according to the following criteria.

∘: There is no roughness, the dot shape is a perfect circle, ○: A slight roughness is visible, the dot shape is a perfect circle, Δ: The roughness is visible, and the dot shape is slightly disturbed. Appearance and bad dot shape (image storability) K (black) density 1.83, C (cyan) density 1.48, M (magenta) density 1.53, Y
(Yellow) A sample after solid image formation with a density of 1.04 is
The sample was allowed to stand in an environment of 55 ° C. and 48% RH for 3 days, the density of M (magenta) color was measured on behalf of each color, and the change in density was evaluated. The concentration was measured by X-rite 528.

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[Table 4]

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[Table 5]

It can be seen from Tables 4 and 5 that the samples of the present invention have good character quality, color mixing and image storability on various recording media.

[0069]

INDUSTRIAL APPLICABILITY According to the present invention, an ink jet recording method excellent in ink ejection property, image quality and image storability after printing, a precursor composed of an ink composition and a reaction liquid used in the recording method, and a recording method thereof. It is possible to provide a recording medium printed by the method and a recording device used for the recording method.

Claims (11)

[Claims] 1. A radiation curing reaction type ink jet recording method for forming an ink image on a recording medium by a recording head having a plurality of nozzles capable of selectively controlling ejection of ink droplets. An inkjet recording method comprising: mixing an ink composition containing a monomer or an oligomer with at least one reaction liquid containing a photopolymerization initiator, and then discharging the mixture. 2. A radiation curing reaction type ink jet recording method for forming an ink image on a recording medium by a recording head having a plurality of nozzles capable of selectively controlling ejection of ink droplets. An ink jet recording method comprising: mixing an ink composition containing an agent with at least one reaction liquid containing a photopolymerizable monomer or oligomer, and then discharging the mixture. 3. The ink jet recording method according to claim 1, wherein the coloring agent is a pigment. 4. The photopolymerizable monomer or oligomer is monofunctional or bifunctional.
5. The inkjet recording method according to any one of 1. 5. The curing reaction is carried out by UV irradiation,
The inkjet recording method according to any one of claims 1 to 4, wherein the irradiation amount of ultraviolet rays is 100 to 10,000 mJ / cm ² . 6. The inkjet recording method according to claim 1, wherein the ink composition and at least one reaction liquid are heated and mixed immediately before ejection and then ejected. 7. The inkjet recording method according to claim 6, wherein the heating is performed at 40 to 100 ° C. 8. The viscosity of the ink prepared by mixing the ink composition and the reaction liquid is 60 to 10,000 mP at 25 ° C.
a · s and 0.1 to 25 mPa · s at 40 to 100 ° C.
An ink precursor comprising an ink composition and a reaction liquid. 9. A recording medium printed by the inkjet recording method according to claim 1. 10. The recording medium according to claim 9, wherein the recording medium is non-ink absorbing. 11. A recording apparatus used in the ink jet recording method according to claim 1.