JP2001335724A - Ink for ink jet recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an ink for ink jet recording, excellent in continuous ejection characteristics without causing the clogging at the nozzle in an ink jet recording system and improved in various performances insufficient in the prior art. SOLUTION: The ink for ink jet recording is a water-base ink comprising mainly a dye or pigment, a wetting agent and water, and it contains a 2- methacryloyloxyethyl phosphorylcholine monomer and/or polymer.

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 system which does not cause clogging of nozzles in an ink-jet system, has excellent continuous ejection characteristics, and further improves various performances which were insufficient with the prior art. Regarding ink.

[0002]

2. Description of the Related Art Conventionally, aqueous inks for ink-jet recording include various pigments or dyes as coloring components, and water-soluble organic solvents such as polyhydric alcohols and glycol ethers which have a role of increasing the wettability of the ink. Various kinds of aqueous inks for inkjet recording are described in literature, patent publications, etc., in which cations, anions, nonionic surfactants, other amino acids, water-soluble resins and the like for adjusting the surface tension of the ink are appropriately blended. It has been sold and used in reality.

[0003]

However, these water-based inks for ink-jet recording have performance problems such as clogging of nozzles, limitation of continuous ejection performance, and poor long-term stability of the ink. Are often unsatisfactory. An object of the present invention is to provide an ink jet recording ink which does not cause clogging of nozzles in an ink jet system, has excellent continuous jet characteristics, and further improves various performances which were insufficient with the conventional technology. It is in.

[0004]

SUMMARY OF THE INVENTION The present invention relates to an aqueous ink jet recording ink comprising a dye or pigment, a wetting agent and water as main components, wherein 2-methacryloyloxyethyl having the following structural formula is used as an additive. Phosphorylcholine

Embedded image By containing the monomer and / or polymer of the above, the clogging of the nozzle in the ink jet system does not occur, the continuous jetting characteristics are excellent, and various performances which were insufficient with the conventional technology are further improved. I have found that I can get it. At this time, the addition amount of the monomer and / or polymer of 2-methacryloyloxyethyl phosphorylcholine to the aqueous ink for inkjet recording is 0.1 to 1
0% by weight is good.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The monomer and / or polymer of 2-methacryloyloxyethyl phosphorylcholine used in the ink jet recording ink of the present invention is a conventionally known chemical substance and has a very hydrophilic property. It is strong and has sufficient water retention, and it has been confirmed that when added to an aqueous solution, it significantly lowers the surface tension of the aqueous solution. To date, it has been used in cosmetics, various medical materials, contact lenses, etc. I have. This 2-methacryloyloxyethyl phosphorylcholine is a zwitterionic compound having an anionic group and a cationic group in the molecule as is clear from the structural formula. Therefore, it is considered that the above-mentioned properties having extremely strong hydrophilicity, sufficient water retention, and remarkably lowering the surface tension of the aqueous solution are obtained by being an amphoteric ion compound.

[0006] The present invention provides the disadvantageous performance of conventional ink compositions by adding a monomer and / or polymer of 2-methacryloyloxyethyl phosphorylcholine to a conventionally known aqueous ink for ink jet recording. It has been found that problems such as clogging of nozzles, short continuous ejection time, and solidification of ink during long-term storage can be solved because 2-metachrome having sufficient water retention as described above. By adding the monomer and / or polymer of yloxyethyl phosphorylcholine to the ink composition, the drying property of the ink is significantly reduced, whereby the ink hardly hardens,
Furthermore, the ink composition itself becomes very hydrophilic,
As a result, the surface of the nozzle head is made hydrophilic, so that clogging of the ink at the nozzles can be prevented, and the continuous ejection time can be extended due to a synergistic effect thereof.

The amount of the monomer and / or the polymer of 2-methacryloyloxyethyl phosphorylcholine in the ink jet recording ink of the present invention is 0.1 to 10% by weight.
When the amount is less than 0.1% by weight, the above-described effects are reduced. When the amount is more than 10% by weight, the viscosity of the ink increases,
This becomes an obstacle when ejecting ink, and also increases the cost.

A dye and a pigment can be used in the aqueous ink jet recording ink of the present invention. As the dye, any dye having good solubility in water is used. Specific examples of the dye include, as a direct dye, CIDirect
Black 2,4,9,11,14,17,19,22,27,32,36,38,41,48,49,5
1,56,62,71,74,75,77,78,80,105,106,107,108,112,113,
117,132,146,154,194, CIDirect Yellow 1,2,4,8,11,
12,24,26,27,28,33,34,39,41,42,44,48,50,51,58,72,8
5,86,87,88,98,100,110, CIDirect Orange 6,8,10,2
6,29,39,41,49,51,102, CIDirect Red 1,2,4,8,9,11,
13,17,20,23,24,28,31,33,37,39,44,46,47,48,51,59,6
2,63,73,75,77,80,81,83,84,85,90,94,99,101,108,110,
145,189,197,220,224,225,226,227,230, CIDirect Vi
olet 1,7,9,12,35,48,51,90,94, CIDirect Blue 1,2,
6,8,15,22,25,34,69,70,71,72,75,76,78,80,81,82,83,8
6,90,98,106,108,110,120,123,158,163,165,192,193,19
4,195,196,199,200,201,202,203,207,218,236,237,239,
246,258, CIDirect Green 1,6,8,28,33,37,63,64, C.
I.Direct Brown 1A, 2,6,25,27,44,58,95,100,101,106,1
12,173,194,195,209,210,211.

[0009] Acid dyes include CIAcid Black 1,2,
7,16,17,24,26,28,31,41,48,52,58,60,63,94,107,109,1
12,118,119,121,122,131,155,156, CIAcid Yellow 1,
3,4,7,11,12,13,14,17,18,19,23,25,29,34,36,38,40,4
1,42,44,49,53,55,59,61,71,72,76,78,99,111,114,116,
122,135,161,172, CIAcid Orange 7,8,10,33,56,64,
CIAcid Red 1,4,6,8,13,14,15,18,19,21,26,27,30,3
2,34,45,37,40,42,51,52,54,57,80,82,83,85,87,88,89,
92,94,97,106,108,110,111,119,129,131,133,134,135,1
54,155,172,176,180,184,186,187,243,249,254,256,26
0,289,317,318, CIAcid Violet 7,11,15,34,35,41,4
3,49,75, CIAcid Blue 1,7,9,22,23,25,27,29,40,41,
43,45,49,51,53,55,56,59,62,78,80,81,83,90,92,93,10
2,104,111,113,117,120,124,126,145,167,171,175,183,
229,234,236, CIAcid Green 3,12,19,27,41,9,16,20,
25, CIAcid Brown 4,14, and the like.

As basic dyes, CIBasic Black 2,
8, CIBasic Yellow 1,2,11,12,14,21,32,36, CIBas
ic Orange 2,15,21,22, CIBasic Red 1,2,9,12,13,3
7, CIBasic Violet 1,3,7,10,14, CIBasic Blue 1,
3,5,7,9,24,25,26,28,29, CIBasic Green 1,4, CIB
asic Brown 1,12, and the like.

As the reactive dye, CIRective Black is used.
1,3,5,6,8,12,14, CIRective Yellow 1,2,3,13,14,1
5,17, CIRective Orange 2,5,7,16,20,24, CIRecti
ve Red 6,7,11,12,15,17,21,23,24,35,36,42,63,66, C.
I.Rective Violet 2,4,5,8,9, CIRective Blue 2,5,
7,12,13,14,15,17,18,19,20,21,25,27,28,37,38,40,41,
71, CIRective Green 5,7, CIRective Brown 1,7,1
6, and the like.

[0012] Food colors include CIFood Black 2, C.I.
I. Food Yellow 3,4,5, CIFood Red 2,3,7,9,14,52,8
7,92,94,102,104,105,106, CIFood Violet 2, CIFo
od Blue 1,2, CIFood Green 2,3, and the like.

On the other hand, CI Pigment Yellow is used as a pigment.
24,101,108,109,110,117,120,123,138,139,153, CIP
igment Orange 2,5,17,24,31,36,38,40,43, CI Pigmen
t Red 1,2,3,4,5,7,9,10,12,14,15,17,18,22,23,31,48,
49,50,53,57,58,60,63,64,81,83,87,112,122,123,144,1
46,149,166,168,170,171,175,176,177,178,179,185,18
7,188,189,190,192,194,208,209,216,243,245, CIPig
ment Violet 1,3,19,23,31,32,33,36,38,43,50, CIPi
gment Blue 1,2,15,16,22,25,63, CIPigmentGreen
8,10,12,47, CI Pigment Brown 1,5,25,26,28, CIPI
gment Black 1,7, and the like.

In the present invention, it is preferable to use a water-soluble organic solvent which is liquid at normal temperature as the wetting agent. Specifically, polyhydric alcohols such as diethylene glycol, glycerin and propylene glycol; alkyl ethers of polyhydric alcohols and acetic acid esters thereof such as ethylene glycol monomethyl ether, diethylene glycol and ethylene glycol monomethyl ether acetate; hydroxyalkyl Formamides; and N
-Vinyl-2-pyrrolidone oligomer is preferably used. These water-soluble organic solvents can be used alone or as a mixture.

The ink jet recording ink of the present invention comprises:
For example, 0.1 to 15% by weight of a pigment or a dye, 1 to 40% by weight of a wetting agent (water-soluble organic solvent), and a monomer and / or weight of 2-methacryloyloxyethyl phosphorylcholine.
1-10% by weight, remaining water is blended. In addition,
The aqueous inkjet recording ink has a viscosity of 1.2 to 30 from a practical viewpoint used in the inkjet method.
It is preferably in the range of mPa · s and the non-volatile content is in the range of about 50% by weight or less. Further, although the pH of the ink and the like can be varied widely, precipitation may occur depending on the type and pH of the anti-fading agent.

The monomer and / or polymer of 2-methacryloyloxyethyl phosphorylcholine used in the present invention has the performance as an amphoteric surfactant itself, but if necessary, may further contain a cationic surfactant. Using anionic surfactants such as alkylpyridinium salts; anionic surfactants such as sodium alkyl sulfate; nonionic surfactants such as polyoxyethylene alkyl ether; or using amphoteric surfactants Is also good. If necessary, a viscosity modifier such as hydroxypropylcellulose, hydroxyethylcellulose, or polyvinyl alcohol, sodium dehydroacetate, 6
-A small amount of a fungicide such as acetoxy-2,4-dimethyl-m-dioxane or a preservative may be added.
Further, an oxygen absorbent such as sodium sulfite and sodium hydrogen sulfite can be used in combination. In addition, when a component such as an acetylene glycol ethylene oxide (EO) adduct that reduces the surface tension of the ink and reduces the contact angle of the ink with the paper is added, the ink adhering to the paper is instantaneously removed from the paper. Has the effect of penetrating and drying.

The ink-jet recording ink of the present invention comprises:
The above components are mixed and dispersed for adjustment. In particular, in the preparation of a pigment type ink, it is preferable to prepare the ink by the following procedure, for example. As a first-stage mixed dispersion, a concentrated dispersion is prepared using a ball mill, a bead mill, an ultrasonic disperser, or the like, and the concentrated dispersion is diluted into an ink formulation, and a high-speed stirrer, a homogenizer, or the like is used as a second stage. After preparing the mixture, the ink was subjected to a filtration treatment using a 0.5 μm filter with a pressure filter to obtain a 0.5 μm
m or more particles are removed to obtain an inkjet recording ink.

[0018]

EXAMPLES Examples of the present invention will be described below, but the present invention is of course not limited to these.

[Example 1] (Pigment concentrated dispersion composition) CI Pigment Black 7: 25.0 wt% Sodium deoxycholate: 8.5 wt% Acetylene glycol EO adduct (EO: 10 mol): 3.6 wt% (River “Acetinol EH” manufactured by Ken Fine Chemical Co., Ltd.) Diethanolamine: 0.6 wt% 2-methacryloyloxyethyl phosphorylcholine monomer: 5.0 wt% Ion exchange water: 57.3 wt% Pigment (CIPigment Black 7) in the above composition Water 55w
After addition of t%, diethanolamine was added while stirring with a mixer, and the pH was adjusted to 8.6.
After addition of t%, 2-methacryloyloxyethylphosphorylcholine and acetylinol EH, the mixture was mixed, and after the viscosity was reduced due to wetness and defoaming of the pigment surface, sodium deoxycholate was added and dispersed by a bead mill. The obtained dispersion was subjected to 6000 to 12000 r.p. p. m. The coarse particles were removed by centrifugation to prepare a concentrated pigment dispersion. (Ink composition) Above pigment dispersion: 20.0 wt% Polyethylene glycol # 200: 8.0 wt% Diethylene glycol monoethyl ether: 2.0 wt% 1,2-Benzisothiazolin-3-one: 0.1 wt% Polyoxy Ethylene alkyl ether phosphate (HLB: 6.5) (“DDP-2” manufactured by Nikko Chemical Co., Ltd.): 2.4 wt% ion-exchanged water: 67.5 wt% Pigment concentrated dispersion in the above composition, DDP- 2. Add water,
After mixing and dispersing with a high-speed stirrer, a homogenizer and the like, adding other organic solvents and organic compounds, and mixing,
The resulting mixture was filtered through a filter of m to prepare an ink composition.

Example 2 (Ink Composition) CIBasic Red 1: 4.0 wt% Glycerin: 4.0 wt% Polyoxyethylene alkyl ether phosphate (HLB: 6.5) (“DDP” manufactured by Nikko Chemical Co., Ltd.) -2 "): 2.0 wt% 2-methacryloyloxyethyl phosphorylcholine polymer (degree of polymerization n = 20): 0.1 wt% Styrene-maleic acid copolymer (MW 18000): 2.9 wt% ions Exchanger: 87.0 wt% The mixture having the above composition was mixed, stirred at a high speed with a disper to form a uniform solution, and then filtered using a 0.5 μm filter to prepare an ink composition.

[Example 3] (Pigment concentrated dispersion composition) CI Pigment Yellow 24: 33.0 wt% Potassium dehydrocholate: 16.0 wt% Acetylene glycol EO adduct (EO: 3.5 mol): 0.8 wt% (“Acetinol EL” manufactured by Kawaken Fine Chemical Co., Ltd.) 2-Methacryloyloxyethyl phosphorylcholine polymer (degree of polymerization n = 20): 10.0 wt% ion-exchanged water: 40.2 wt% Each component having the above composition is mixed and stirred. After that, the mixture was dispersed by a bead mill. The obtained dispersion was subjected to 6000 to 12000
r. p. m. The coarse particles were removed by centrifugation to prepare a concentrated pigment dispersion. (Ink composition) Above pigment dispersion: 10.0 wt% Triethylene glycol: 11.5 wt% Dipropylene glycol monoethyl ether: 2.4 wt% Styrene-maleic acid copolymer (MW 18000): 3 0.5 wt% (“SN Dispersant 5027” manufactured by San Nopco Co., Ltd.) 2-Pyridinethiol-1-oxide sodium: 0.1 wt% ion-exchanged water: 72.5 wt% After mixing in the same manner as in (Ink Composition), the mixture was filtered using a 0.5 μm filter to prepare an ink composition.

Example 4 Imidazole sulfate: 12% by weight CIDirect Black 154: 3% by weight Diethylene glycol: 9% by weight Urea: 2% by weight 2-methacryloyloxyethyl phosphorylcholine monomer: 10% by weight Ion-exchanged water: 64% by weight The formulation was made into a homogeneous solution in the same procedure as in Example 2, and then filtered using a 0.5 μm filter to prepare an ink composition.

Comparative Examples 1 to 4 Comparative Examples 1 to 4 were prepared by removing the monomer or polymer of 2-methacryloyloxyethylphosphorylcholine in Examples 1 to 4 (the amount of ion-exchanged water was reduced accordingly). The ink composition was prepared in exactly the same manner as described above, except that the composition was added to 100 wt%.

[Various Performance Tests] Physical Property Change Test The ink compositions of Examples 1 to 4 and Comparative Examples 1 to 4
It was left in a 0 ° C. constant temperature bath for 6 months, the viscosity was measured before and after that, and the change was observed.な い: no change in viscosity was observed, を: increase in viscosity was within 10% of the initial value, 、: increase in viscosity was 10 to 50% of the initial value, △: gel or hard precipitate was formed. Those were judged as ×, and the results are shown in Table 1.

Printer Printing Test The ink compositions of Examples 1 to 4 and Comparative Examples 1 to 4 were used in a piezo-type ink jet printer, and the following examination was conducted.

2-1) Continuous printing (ink ejection stability) test Continuous printing was performed on 100 sheets by a piezo-type inkjet printer, and the printability was visually observed. Good printability with no bleeding ◎, Slight bleeding and printing disorder ○, Character bleeding but character recognition possible △, Character bleeding and continuous printing impossible Was determined as x, and the results are shown in Table 1.

2-2) Restart (ink clogging) test After printing with a piezo-type inkjet printer,
The printing was performed again by leaving the ink cap open at 40 ° C. for 2 hours, and clogging and the like were confirmed by comparing the printed matter. No clogging and good printability ◎, slight omission due to clogging observed ○, clogged but printable by simple recovery operation △, printing impossible Some were evaluated as x, and are shown in Table 1.

[Test results]

[Table 1]

[0029]

As described above, the ink jet recording ink of the present invention can be applied to both the pigment type and the dye type, has high storage stability, does not cause aggregation, deterioration, etc. of the ink. Since the surface of the nozzle surface is treated with the ink with high hydrophilicity, the ink jet printer has high ejection stability and can realize robust printing without causing clogging of the ink ejection nozzle.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tadao Nakaya 2-35-16 Hongo, Bungo-ku, Tokyo No. 402, Kotas Yummachi 402 (72) Inventor Koji Shigemura 5-7-1 Shiba, Minato-ku, Tokyo NEC F term within the company (reference) 2C056 FA04 FC02 2H086 BA52 BA53 BA55 BA59 BA62 4J039 AD10 AD21 AD23 BC07 BC09 BC11 BC13 BC14 BC20 BC36 BE01 BE02 BE22 CA03 CA06 EA41 EA44 GA24

Claims (2)

[Claims] An aqueous ink jet recording ink comprising a dye or pigment, a wetting agent and water as main components, and having the following structural formula: 2-methacryloyloxyethyl phosphorylcholine An ink for inkjet recording comprising a monomer and / or a polymer of the formula: 2. An ink jet recording ink comprising a monomer and / or polymer of 2-methacryloyloxyethyl phosphorylcholine in an amount of 0.1 to 10% by weight in the ink jet recording ink.