JPH11131002A - Aqueous ink composition for inkjet recording and recording method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-based ink composition for inkjet recording which has excellent long-term storage stability and high reliability. SOLUTION: In an aqueous ink composition for ink jet recording containing a colorant dispersible or soluble in water, at least one or more wetting agents, a surfactant and an antiseptic / fungicide, an isothiazoline compound and pyridine are used as an antiseptic / fungicide. System compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-based ink composition for ink-jet recording, and more particularly, to a printing stability which is excellent in storage stability (antiseptic and fungicidal effects), excellent in water fastness, light fastness and color tone, and further excellent in ejection stability. And a water-based ink composition which is also excellent.

[0002]

2. Description of the Related Art In recent years, ink jet printers have been rapidly spread due to advantages such as low noise and low running cost. In ink-jet recording, in order to perform good print recording over a long period of time, the properties required for the ink (aqueous ink composition) used are excellent in long-term storage stability and ejection stability, The resulting image is a clear image without bleeding, and has excellent water resistance, light resistance, etc., that is, excellent storage stability. However, in order to satisfy the above requirements, many proposals have been made on inks used for ink jet recording, but an ink satisfying all the above requirements has not yet been obtained. In particular, preventing nozzle clogging is an important issue,
The possible causes include thickening of the ink due to evaporation of water at the nozzle tip, or precipitation of dyes, formation of insoluble inorganic salts, or formation of insoluble solids due to the invention of microorganisms such as molds and spoilage fungi.

[0003] The thickening of ink and the precipitation of dye due to evaporation of water can be solved by using a wetting agent having low viscosity and high solubility for dye. Several proposals have been made, but they are not satisfactory at present. For example, according to JP-A-55-16037, 2,4,6-hexahydro-1,3,5
JISZ 291 describes that the presence of -trihydroxyethyl-S-triazine has a fungicidal effect.
According to the mold resistance test method 1, the effect is not yet sufficient. According to Japanese Patent Application Laid-Open No. HEI 6-234943, it is effective to include 1,2-benzisothiazolin-3-one in an ink, but the effect may be sufficient depending on the formulation of the ink. Absent. Further, according to Japanese Patent Application Laid-Open No. 1-213376, it is possible to provide an ink in which a basic substance is contained in the ink and the pH of the ink is increased so that bacteria and the like are hardly propagated without adding a bactericide. However, such ink has a problem in safety when a user uses a printer.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an aqueous ink composition, particularly an aqueous ink composition for ink-jet recording, which has solved all of the above-mentioned conventional disadvantages. More specifically, it is an object of the present invention to provide an aqueous ink composition having excellent long-term storage stability and high reliability, and a recording method using the same.

[0005]

According to the present invention, firstly, there is provided a water-based ink for ink-jet recording comprising a colorant which is dispersed or dissolved in water, at least one or more wetting agents, a surfactant and a preservative and fungicide. A water-based ink composition for ink-jet recording, characterized in that the ink composition contains an isothiazoline-based compound and a pyridine-based compound simultaneously as a preservative and fungicide.

Secondly, there is provided an aqueous ink composition for ink-jet recording, characterized in that the aqueous ink composition for ink-jet recording described in the first aspect contains at least an anionic surfactant as a surfactant. You.

Third, in the aqueous ink composition for ink jet recording described in the second aspect, the anionic surfactant is a polyoxyethylene alkyl ether acetate represented by the following general formula (I) or the following general formula: A water-based ink composition for inkjet recording characterized by being a dialkyl sulfosuccinate represented by (II).

Embedded image RO (CH ₂ CH ₂ O) CH ₂ COOM (I)

Embedded image (R: a straight or branched alkyl group having 13 to 14 carbon atoms, R ': a straight or branched alkyl group having 5 to 7 carbon atoms, n: an integer of 3 to 12, M: alkali metal, quaternary Ammonium, quaternary phosphonium or alkanolamine)

Fourthly, in the aqueous ink composition for ink jet recording described in the third aspect, the counter ion M of the carboxylic acid group or sulfonic acid group of the anionic surfactant is sodium, lithium and / or the following general formula: There is provided an aqueous ink composition for inkjet recording, which is a quaternary ammonium, quaternary phosphonium, or alkanolamine ion represented by (III).

Embedded image (X: nitrogen or phosphorus, R _{1 to} R ₄ : alkyl group having 1 to ₄ carbon atoms, hydroxyalkyl group, halogenated alkyl group, hydrogen)

Fifth, in the aqueous ink composition for ink jet recording described in the first aspect, the colorant is a compound represented by the following general formula (IV) and / or the following general formula (V)
Wherein the aqueous ink composition for inkjet recording is provided.

Embedded image

Embedded image (A, B: alkyl group, alkoxy group, halogen D: alkanolamino group, hydroxyl group M ': alkali metal, quaternary ammonium, quaternary phosphonium or alkanolamine m: an integer of 0 to 3)

Sixth, the aqueous ink composition for ink jet recording according to the first aspect, wherein the colorant is a compound represented by the following general formula (VI): Is provided.

Embedded image M ': alkali metal, quaternary ammonium, quaternary phosphonium or alkanolamine)

Seventh, in the aqueous ink composition for ink jet recording described in the first aspect, the colorant is a compound represented by the following general formula (VII) and / or a compound represented by the following general formula (VII):
There is provided an aqueous ink composition for inkjet recording, which is a compound represented by the formula (I).

Embedded image

Embedded image (I, j: integer and i + j = 3, l: integer of 0 to 2, E: H, COOM M ′: alkali metal, quaternary ammonium, quaternary phosphonium or alkanolamine)

Eighth, in the aqueous ink composition for ink jet recording described in the first aspect, the colorant is a compound represented by the following formula (IX) and / or a compound represented by the following formula (X):
Wherein the aqueous ink composition for inkjet recording is provided.

Embedded image

Embedded image (L: 0 to 2 integer, E: H, COOM, G : H, NH 2, J: H, OH, R: H, CH 2 COOM, M ': alkali metal, quaternary ammonium, quaternary Phosphonium or alkanolamine)

Ninth, the aqueous ink composition for ink-jet recording according to any one of the first to eighth aspects, wherein the pH of the aqueous ink composition is 9 or more and 1 or less. An ink composition is provided.

Tenth, the aqueous ink composition for ink-jet recording described in any one of the first to ninth above is made to fly into fine droplets by thermal energy or mechanical energy, and the droplets are scattered with a Steckigt size of 3 seconds. A recording method characterized in that an image is formed by attaching the recording medium to the recording material described above.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to an ink containing a colorant which is dispersed or dissolved in water, at least one or more wetting agents, a surfactant and an antiseptic and fungicide. It has been found that by simultaneously containing a compound and a pyridine-based compound, a water-based ink composition having excellent long-term storage stability (preservative and antifungal effects) and being reliable can be obtained.

The effect of the isothiazoline compound and the effect of the pyridine compound are different from each other. Therefore, by simultaneously containing both, it is possible to obtain a higher antiseptic and fungicidal effect. Isothiazoline preservatives penetrate into the cells, react with thiol-containing enzymes,
While it has the effect of causing respiratory metabolism inhibition, pyridine-based preservatives disperse Mg ions and Ca
It has the effect of forming chelates with ions and causing obstacles to substance permeation. A preferable mixing ratio of both is 1:10 to 1
0: 1, more preferably 1: 3 to 3: 1.
Range. The combined amount of both is preferably 0.01 to 1.0% by weight, more preferably 0.1 to 0.5% by weight, based on the total weight of the ink. These preservatives and fungicides have no effect if the amount added is less than 0.01% by weight, and if 1.0% by weight is obtained, a coagulation component may be formed between the antiseptic and the dye-wetting agent, or the water evaporation of the ink may occur. , And may cause clogging.
Table 1 shows specific compounds used in the present invention, but the present invention is not limited thereto.

[0017]

[Table 1]

Further, according to the present invention, it has been found that the use of at least one anionic surfactant as the surfactant in the aqueous ink composition enhances the effect. This is presumably because anionic surfactants have a higher antibacterial effect than nonionic surfactants, and therefore have a synergistic effect when used in combination with a fungicide. Examples of the anionic surfactant include those having a carboxylic acid group, those having a sulfonic acid group, those having a sulfate ester group, and those having a phosphate ester group. When the polyoxyethylene alkyl ether acetate and dialkyl sulfosuccinate represented by (II) and (II) are used, it is possible to obtain an aqueous ink composition which is quick-drying, provides high-quality image quality, and has high credibility. is there. In the general formulas (I) and (II), R has 13 carbon atoms.
Are preferred. Further, n is most preferably n = 3. R 'preferably has 5 or 7 carbon atoms.

The above-mentioned polyoxyethylene alkyl ether acetate or dialkyl sulfosuccinate is added to reduce the surface tension of the ink and increase the permeability of the ink to the paper, thereby speeding the drying of the printed image. The addition amount is adjusted so that the surface tension of the ink is usually 50 mN / m or less, preferably 40 mN / m or less, and based on the total amount of the aqueous ink composition.
0.01 to 3.0% by weight is preferred. When the amount of the surfactant is less than 0.01% by weight, the drying property is poor because the dynamic surface tension is high. On the other hand, when the amount is more than 3.0% by weight, precipitation of the surfactant during storage may occur. Occurs. Further, dialkylsulfosuccinate is decomposed when left on the alkali side, and thus is usually used after adjusting the pH.

The above-mentioned polyoxyethylene alkyl ether acetate as an anionic surfactant is, specifically, Nikkor ECT series (Nippon Surfactant Chemical Company)
Available as such. Further, dialkyl sulfosuccinate can be obtained as aerosol OB-70 (Toho Chemical Co., Ltd.), aerosol MA-80, AY-100 (Mitsui Cyanamid Co., Ltd.) and the like.

In some cases, a nonionic surfactant may be used together as long as the effect is not impaired. Specific examples of nonionic surfactants that can be used include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene glycol ester, and acetylene glycol. The BT series (Nikko Chemicals) and the Nonipol series ( Sanyo Kasei Co., Ltd.), Surfynol Series (Air Products), etc.

The counter ion M of the carboxylic acid group of the polyoxyethylene alkyl ether acetate or the sulfonic acid group of the dialkyl sulfosuccinate may be sodium, lithium and / or the quaternary ammonium represented by the above formula (III). When the compound is a quaternary phosphonium or alkanolamine ion, excellent dissolution stability, ejection stability and a good printed image can be obtained.

In the aqueous ink composition of the present invention, the use of the dyes represented by the general formulas (IV) to (X) provides high weather resistance, particularly high water resistance, excellent color tone, and high reliability. An ink having high property can be obtained.

Table 2 shows the surfactants used in the present invention.
Table 3 shows specific examples of the dye, but the present invention is not limited thereto.

[0025]

[Table 2]

[0026]

[Table 3- (1)]

[0027]

[Table 3- (2)]

[0028]

[Table 3- (3)]

[0029]

[Table 3- (4)]

[0030]

[Table 3- (5)]

[0031]

[Table 3- (6)]

In order to make the sulfonate group or carboxylic acid group of the surfactant and the dye used in the present invention into an alkali salt, when dissolving it in water at the time of preparing the ink, an alkali hydroxide containing a desired alkali ion is used. It can be easily done by adding. For example, in the case of a lithium salt, this can be performed by adding lithium hydroxide. For the quaternary ammonium, phosphonium, and alkanolamine cations of the general formula (III), specifically, the hydroxides shown in Table 4 are added. It is done by doing.

[0033]

[Table 4]

In the present invention, it is not necessary that all the counter ions of the surfactant or the dye are sodium, lithium and / or the compound of the above formula (III).
It can also be mixed with other alkali ions. Another preferable counter ion is triethanolamine.
The amount of ions of sodium, lithium and / or the compound of the above general formula (III) is added so as to be 30% or more, more preferably 50% or more, based on the number of moles of the surfactant or the dye. Is preferred.

Although the ink composition of the present invention uses water as a liquid medium, the ink composition of the present invention is used to obtain desired physical properties of the ink or to prevent the ink from drying. The following are examples of the wetting agent added for the purpose of improving the dissolution stability of the compound.

Ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, chrycerol, 1,5
-Pentanediol, 1,6-hexanediol, 1,
Polyhydric alcohols such as 2,6-hexanetriol, 1,2,4-butanetriol, 1,2,3-butanetriol, petriol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol Polyhydric alcohol alkyl ethers such as monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether; polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether; Pyrrolidone, N-methyl-2-pyrrolidone, N
-Hydroxyethyl-2-pyrrolidone, 1,3-dimethylimidazolidinone, nitrogen-containing heterocyclic compounds such as ε-caprolactam, formamide, N-methylformamide,
Amides of N, N-dimethylformamides, amines such as monoethanolamine, diethanolamine, triethanolamine, monoethylamine, diethylamine, and triethylamine; sulfur-containing compounds such as dimethyl sulfoxide, sulfolane, and thiodiethanol; propylene carbonate; Ethylene and γ-butyrolactone.

These solvents are used alone or in combination with water. The pH of the ink composition
Is 9 or more, the storage stability of the ink can be further improved, and copy papers and the like used in offices often have a pH of 5 to 6, and these recording papers have an ink of 20 to 60 μm. The discharge weight is 10-1 from the fine discharge port of
A recording method for forming a high-quality, high-resolution, high-resolution image by recording a droplet of 60 ng at a speed of 5 to 20 m / s and recording on a so-called plain paper having a Steckigt sizing degree of 3 seconds or more. Can be. However, when the activator shown in Chemical formula 2 is used, the pH is 11 or more, and the activity is lost due to decomposition of the cabinet agent during storage.
It is desirable to set it to 1 or less.

The penetrant added in addition to the surfactant used in the present invention for the purpose of adjusting the surface tension includes:
Alkyl and aryl ethers of polyhydric alcohols such as diethylene glycol monophenyl ether, ethylene glycol monophenyl ether, ethylene glycol monoallyl ether, diethylene glycol monophenyl ether, and diethylene glycol chlorophenyl ether, fluorine-based surfactants, acetylene-based surfactants, ethanol, Lower alcohols such as 2-propanol are exemplified, and particularly preferred is diethylene glycol monobutyl ether.

In the ink of the present invention, conventionally known additives can be added in addition to the coloring agent, the solvent, the preservative and the fungicide. For example, examples of the rust preventive include acidic sulfite, sodium thiosulfate, ammonium thioglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, dicyclohexylammonium nitrite, and the like. A water-soluble ultraviolet absorber and a water-soluble infrared absorber can be added according to other purposes.

[0040]

The present invention will be more specifically described below with reference to examples and comparative examples.

Examples 1 to 8 and Comparative Examples 1 to 12 Ink compositions formulated with the compositions shown in Tables 5 and 6 were dissolved by stirring at room temperature, and filtered with a 0.22 μm Teflon filter. Then, deaeration was further performed for about 30 minutes to produce an aqueous ink.

[0042]

[Table 5]

[0043]

[Table 6]

Next, the above Examples 1 to 8 and Comparative Examples 1 to 1
2 was evaluated as follows. Table 7 shows the results of the preservative / antifungal test, and Table 8 shows other test results.

1) Antiseptic and mold tests 10% of each test cell suspension * and mixed spore suspension ** were inoculated to each 10 ml of ink every predetermined day, and placed in a thermostat adjusted to 28 ± 2 ° C. After 2 days, the presence or absence of bacterial growth is examined by the pour culture method. This cycle was repeated 10 times, and the antiseptic and antifungal effects were determined.な し indicates no growth of the bacterium and X indicates presence of the bacterium. * Test cell suspension: The following strains were suspended in a broth culture solution. Bacillis subtilis E
scherichiacoli Proteus vu
lgaris Pseudomonas aerugi
nosa Staphylococcus aureu
s ** Mixed spore suspension: Make a 0.005% aqueous solution of dioctyl sodium sulfosuccinate in an Erlenmeyer flask and sterilize with an autoclave. Next, spores of the following test bacteria are taken one platinum loop at a time, and in addition, the spores are sufficiently dispersed. The contents are filtered through dry heat sterilized filter paper and placed in another flask. *** Gravy broth: 3 g meat extract, 10 g peptone,
5 g of sodium chloride dissolved in 100 ml of distilled water, and then sterilized in an autoclave at 121 ° C. for 15 minutes. 2) Clarity of Image Printing is performed by an ink jet printer having a 300 dpi nozzle of a thermal ink jet system and an ink jet printer having a nozzle of 300 dpi using a laminated PZT for heating a liquid chamber flow path.
The concentration was visually judged comprehensively. The printing paper was printed on three types of commercially available recycled paper, woodfree paper, and bond paper. 3) Image Water Resistance The printed image sample was immersed in water at 30 ° C. for 1 minute, the change in image density before and after immersion was measured with a Macbeth densitometer, and the water fading rate was determined by the following equation.

[0046]

## EQU1 ## Water fading resistance (%) = [1- (image density before processing /
(Image density after processing)] × 100

Regarding any of the papers, ○ indicates less than 20%, Δ indicates less than 30%, and X indicates 30% or more. 4) Drying of Image The filter paper was pressed against the image after printing under certain conditions, and the time until the ink was not transferred to the filter paper was measured. If any of the papers dried within 10 seconds, it was judged as "good". 5) Storage stability Put each ink in a polyethylene container,
It was stored at 20 ° C. and 70 ° C. for 3 months under the respective conditions, and the surface tension, viscosity, and the presence or absence of precipitate deposition after storage were examined.
A sample that did not change in physical properties and the like even when stored under any conditions was marked as “○”. 6) Reliability at the time of printing pause In the printer used in the test 2), it is examined how much time (seconds) can be restored even if printing is paused without capping or cleaning during operation. The reliability was evaluated based on whether the ejection direction was shifted or the weight of the ejected droplet changed. A sample having an ejection reliability of 500 seconds or more was rated as ○, 200 seconds or more and less than 500 seconds as Δ, and less than 200 seconds as ×.

[0048]

[Table 7]

[0049]

[Table 8]

[0050]

As described above, according to the present invention, an isothiazoline-based compound and a pyridine-based compound are simultaneously contained as a preservative and fungicide to thereby provide a long-term storage stability and a highly reliable aqueous solution for inkjet recording. An ink composition can be obtained. Further, effects obtained from the configurations described in the second to tenth aspects will be described below in order. That is, according to the configuration described in the second aspect, by adding an anionic surfactant, it is possible to obtain a water-based ink for inkjet recording which shows higher storage stability and is excellent in reliability. According to the configuration described in the third aspect, by using the above-described specific anionic surfactant, the permeability to paper is increased, the drying speed of the recorded image is high, and an image with little bleeding is obtained. The resulting aqueous ink composition can be obtained. According to the configuration described in the fourth aspect, by selecting the counter ion of the anionic surfactant, the solubility stability in water can be improved, and the aqueous ink having excellent storage stability and jetting stability can be obtained. A composition is obtained. According to the constitutions described in the fifth to ninth aspects, by using the specific dye, an ink having high weather resistance, particularly high water resistance, excellent color tone, and high reliability can be obtained. According to the configuration described in the tenth aspect, an image having high weather resistance, particularly high water resistance, excellent color tone, and high reliability can be formed.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Masato Igarashi 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Hirotaka Mochizuki 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Inside Ricoh Company (72) Inventor Masayuki Kotani 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh Company (72) Inventor Takanori Tsukiki 1-3-6 Nakamagome, Ota-ku, Tokyo Stock Company Ricoh Company (72) Inventor Ikuko Yamada 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd.

Claims (10)

[Claims] 1. A water-based ink composition for ink jet recording comprising a colorant which is dispersed or dissolved in water, at least one or more wetting agents, a surfactant and an antiseptic / fungicide, comprising an isothiazoline compound as an antiseptic / fungicide. A water-based ink composition for ink jet recording, characterized by simultaneously containing a pyridine compound. 2. The aqueous ink composition for ink-jet recording according to claim 1, further comprising at least an anionic surfactant as a surfactant. 3. The aqueous ink composition for ink-jet recording according to claim 2, wherein the anionic surfactant is a polyoxyethylene alkyl ether acetate represented by the following general formula (I) or the following general formula (II): A water-based ink composition for inkjet recording, which is a dialkyl sulfosuccinate represented by the formula: Embedded image RO (CH ₂ CH ₂ O) CH ₂ COOM (I) (R: a straight or branched alkyl group having 13 to 14 carbon atoms, R ': a straight or branched alkyl group having 5 to 7 carbon atoms, n: an integer of 3 to 12, M: alkali metal, quaternary Ammonium, quaternary phosphonium or alkanolamine) 4. The aqueous ink composition for ink-jet recording according to claim 3, wherein the counter ion M of the carboxylic acid group or sulfonic acid group of the anionic surfactant is sodium, lithium and / or the following general formula (III): A quaternary ammonium, quaternary phosphonium or alkanolamine ion represented by the formula: Embedded image (X: nitrogen or phosphorus, R _{1 to} R ₄ : alkyl group having 1 to ₄ carbon atoms, hydroxyalkyl group, halogenated alkyl group, hydrogen) 5. The aqueous ink composition for ink jet recording according to claim 1, wherein the colorant is a compound represented by the following general formula (IV) and / or a compound represented by the following general formula (V). A water-based ink composition for ink-jet recording characterized by the following. Embedded image Embedded image (A, B: alkyl group, alkoxy group, halogen D: alkanolamino group, hydroxyl group M ': alkali metal, quaternary ammonium, quaternary phosphonium or alkanolamine m: an integer of 0 to 3) 6. The aqueous ink composition for ink jet recording according to claim 1, wherein the colorant is a compound represented by the following general formula (VI). Embedded image M ': alkali metal, quaternary ammonium, quaternary phosphonium or alkanolamine) 7. The aqueous ink composition for ink-jet recording according to claim 1, wherein the colorant is a compound represented by the following general formula (VII) and / or a compound represented by the following general formula (VIII). A water-based ink composition for ink-jet recording characterized by the following. Embedded image Embedded image (I, j: integer and i + j = 3, l: integer of 0 to 2, E: H, COOM M ′: alkali metal, quaternary ammonium, quaternary phosphonium or alkanolamine) 8. The aqueous ink composition for inkjet recording according to claim 1, wherein the colorant is a compound represented by the following general formula (IX) and / or a compound represented by the following general formula (X). A water-based ink composition for ink-jet recording characterized by the following. Embedded image Embedded image (L: 0 to 2 integer, E: H, COOM, G : H, NH 2, J: H, OH, R: H, CH 2 COOM, M ': alkali metal, quaternary ammonium, quaternary Phosphonium or alkanolamine) 9. The aqueous ink composition for ink jet recording according to claim 1, wherein the pH of the aqueous ink composition is 9 or more and 1 or less. 10. A recording material having a Steckigt size of 3 seconds or more by flying the aqueous ink composition for ink jet recording according to claim 1 into fine droplets by thermal energy or mechanical energy. A recording method comprising forming an image by adhering to a recording medium.