JP3491428B2 - Inkjet recording liquid and method for producing the same - Google Patents

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 liquid having excellent water resistance and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, as an ink jet recording liquid, a water-soluble dye such as an acid dye, a direct dye or a basic dye dissolved in a glycol solvent and water is often used (for example, JP-A-53). -61412, JP-A-54-8
9811, JP-A-55-65269). As the water-soluble dye, those having high solubility in water are generally used in order to obtain stability of the recording liquid. Therefore, the ink jet recorded matter generally has poor water resistance, and there is a problem that spillage of water easily causes bleeding of the dye in the recorded portion.

In order to improve such poor water resistance,
Attempts have been made to change the structure of the dye and to prepare a recording liquid having strong basicity (Japanese Patent Laid-Open No. 56-57862). Further, it is also attempted to improve the water resistance by making good use of the reaction between the recording paper and the recording liquid (Japanese Patent Laid-Open No. 50900/50).
4, JP-A-57-36692, JP-A-59-2069
6, JP-A-59-146889). Although these methods have remarkable effects on specific recording papers, they lack versatility in that they are restricted by recording papers, and when a non-specific recording paper is used, a water-soluble dye is used. In many cases, the recording liquid used cannot obtain sufficient water resistance of the recorded matter.

Recording liquids having good water resistance include those in which an oil-soluble dye is dispersed or dissolved in a high boiling point solvent and those in which an oil-soluble dye is dissolved in a volatile solvent. There is a problem of the emission of sewage, which is not environmentally preferable.
Further, there is a problem that solvent recovery or the like is required when a large amount of recording is performed or depending on the installation location of the device. Therefore,
In order to improve the water resistance of a recorded matter, a recording liquid in which a pigment is dispersed in an aqueous medium has been developed. In a recording liquid for inkjet, the diameter of the nozzle is becoming smaller as a printer is required to have a higher resolution, and the particle diameter of the colorant is also becoming smaller accordingly. However, miniaturization enables transparency and sharpness comparable to dyes in image formation on transparent substrates such as overhead projectors, but on recording paper, dyes dye recording paper fibers to obtain clear images. On the other hand, when a pigment-dispersed recording liquid is used, the pigment falls between the fibers and the color of the underlying recording paper cannot be concealed, resulting in a problem of impaired clarity. . This problem has become remarkable with the miniaturization of pigments. Although the improvement of sharpness can be improved by increasing the amount of the aqueous resin as a binder, its amount is limited because it causes a remarkable increase in viscosity and adversely affects the ejection stability.

[0005]

SUMMARY OF THE INVENTION The present invention relates to an ink jet recording liquid which solves the above-mentioned problems of the conventional methods and can obtain a clear and clear image quality.

[Means for Solving the Problems]

The present invention comprises an aqueous pigment dispersion in which an organic pigment is dispersed in the presence of an emulsion of rosin in an aqueous liquid, and an emulsion of rosin, which is a recording liquid for ink jet recording. Regarding

Further, the present invention relates to the above recording liquid for ink jet, wherein the emulsion of rosin has a particle size of 10 nm to 1 μm. Further, the present invention is characterized in that the organic pigment is one kind selected from the group consisting of quinacridone type, phthalocyanine type, azo type, isoindolinone type, dianthraquinonyl red type, slene type and perylene type. The present invention relates to the inkjet recording liquid.

Further, in the present invention, the dispersed particle diameter of the pigment is 0.0
The recording liquid for ink jet is characterized by having a thickness of 2 to 0.2 μm. Further, the present invention relates to the ink jet recording liquid, which contains an organic pigment in a solid content of 0.1 to 10% by weight. Furthermore, the present invention has a viscosity of 0.
The recording liquid for inkjet is characterized by having a viscosity of 8 to 15 mPa · s (25 ° C.).

Further, in the present invention, an organic pigment is dispersed in the presence of a rosin emulsion to prepare a concentrated aqueous pigment dispersion, which is diluted by adding water and an additive and having a pore diameter of 1 μm.
The present invention relates to a method for producing an inkjet recording liquid, which comprises filtering with a filter of m or less.

DETAILED DESCRIPTION OF THE INVENTION

The pigment used in the present invention is not particularly limited as long as it is not soluble in water. Examples of insoluble dyes include water-insoluble dyes such as disperse dyes and oil-soluble dyes, and insolubilized dyes such as direct dyes, acid dyes, and basic dyes by lake formation. However, dyes that are completely soluble in the synthetic resin used are excluded from the present invention.

Examples of organic pigments include insoluble azo pigments such as toluidine red, toluidine maroon, Hansa yellow, benzidine yellow, and pyrazolone red, resole red, heliobordeaux, pigment scarlet,
Soluble azo pigments such as Permanent Red 2B, phthalocyanines such as phthalocyanine blue and phthalocyanine green, quinacridones such as quinacridone red and quinacridone magenta, perylenes such as perylene red and perylene scarlet, isoindolinone yellow,
Isoindolinone series such as isoindolinone orange,
There are dianthraquinonyl red type and slene type derived from vat dyes. Examples of such a pigment include the following pigments.

It is indicated by a color index (CI) number. CI Pigment Yellow 12, 13, 14, 17, 2
0, 24, 74, 83, 86 93, 109, 110,
117, 125, 137, 138, 147, 148, 1
53, 154, 166, 161, CI Pigment Orange 13, 16, 36, 43, 51, 55, 59, 61,
CI Pigment Red 9, 48, 49, 52, 53, 5
7, 97, 122, 123, 149, 168, 177,
180, 192, 215, 216, 217, 220, 2
23, 224, 226, 227, 228, 238, 24
0, CI pigment violet 19, 23, 29, 3
0, 37, 40, 50, CI Pigment Blue 15, 1
5: 1, 15: 3, 15: 4, 15: 6, 22, 60,
64, CI pigment green 7, 36, CI pigment brown 23, 25, 26, and the like. The content of the pigment is preferably 0.1 to 10% by weight in the recording liquid.

The rosin used in the present invention is gum rosin, polymerized rosin, disproportionated rosin, hydrogenated rosin, maleated rosin, fumarized rosin, wood rosin, tall oil rosin, or esterified products thereof with glycerin or erythritol, Examples thereof include maleated rosin pentaester and maleated rosin glycerin ester. Two or more kinds of rosin may be used together to form an emulsion.

The emulsion of rosin is prepared by using an emulsifying and dispersing device such as Nanomizer or Harmonizer (manufactured by Nanomizer Co., Ltd.), whereby a stable and uniform emulsion can be obtained. The nonvolatile content of the emulsion (solid content of rosin, the balance being water or lower alcohol) can be in the range of 1 to 90% by weight, but 30 to 60% by weight is desirable from the viewpoint of handling and stability. The emulsion of rosin has a particle size of 10 nm to 1 μm, more preferably 20 nm.
˜200 nm is preferable for achieving the stability of the emulsion and the effects peculiar to the present invention. The rosin emulsion is preferably added at the time of dispersion for preparing the aqueous pigment dispersion, and may be added after the aqueous pigment dispersion is prepared. The addition amount is 0.5 to 20% by weight (solid content conversion) in the recording liquid, and preferably 1 to 10% by weight. If this addition amount is too small, the sharpness cannot be obtained. Further, if it is too large, the ejection stability may be impaired.

In the present invention, an aqueous resin may be used in combination in order to further improve the fixing property of the pigment. As the water-based resin, a water-soluble resin that dissolves in water or a water-dispersible resin that is dispersed in water is used alone or as a mixture. As such a water-based resin, acrylic, styrene-acrylic,
There are water-soluble resins such as polyester-based, polyamide-based, and polyurethane-based resins that are soluble in water, and water-dispersible resins.

In the present invention, the aqueous solvent used in addition to water prevents the recording liquid from drying at the nozzle portion and solidifying the recording liquid, and prevents stable ejection of the recording liquid and drying of the nozzle over time. It is a thing. Examples of such an aqueous solvent include ethylene glycol, diethylene glycol, propylene glycol, triethylene glycol, polyethylene glycol, glycerin, tetraethylene glycol, dipropylene glycol, ketone alcohol, diethylene glycol monobutyl ether, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether. 1,2-hexanediol, N-methyl-
2-pyrrolidone, substituted pyrrolidone, 2,4,6-hexanetriol, tetrafurfuryl alcohol, 4-methoxy-4-methylpentanone and the like can be exemplified.

For the purpose of accelerating the drying of the recording liquid on paper, alcohols such as methanol, ethanol and isopropyl alcohol can be used. These aqueous solvents are used alone or as a mixture in the range of 1 to 50% by weight of the recording liquid. As the medium of the recording liquid, deionized water or distilled water from which metal ions have been removed is used.

When the material to be printed with the recording liquid is like paper,
A penetrant can be added in order to accelerate the permeation of the recording liquid into the paper and the apparent dryness. Such penetrants include glycol ethers such as diethylene glycol monobutyl ether described as aqueous solvents, alkylene glycols, alkylene diols, polyethylene glycol monolauryl ether, sodium lauryl sulfate, sodium dodecylbenzene sulfonate, sodium oleate, dioctyl sulfosuccinic acid. Sodium or the like can be used. These have sufficient effects when used in an amount of 5% or less of the recording liquid, and when the amount is larger than this, bleeding of printing and paper drop (print through) occur, which is not preferable.

A fungicide may be added to the recording liquid of the present invention in order to prevent the generation of mold. Specifically, sodium dehydroacetate, sodium benzoate, sodium pyridinethione-1-oxide, zinc pyridinethione-1-oxide, 1,2-benzisothiazoline-3.
An amine salt of 1-one or 1-benzisothiazolin-3-one is used. These are 0.05 to 1.
About 0% by weight is used.

Further, a chelating agent may be added in order to prevent metal deposition at the nozzle portion and insoluble matter deposition in the recording liquid. The chelating agent blocks metal ions in the recording liquid, and specifically, ethylenediaminetetraacetic acid, sodium salt of ethylenediaminetetraacetic acid, diammonium salt of ethylenediaminetetraacetic acid, ethylenediaminetetraacetic acid. An acid tetraammonium salt or the like can be used in an amount of about 0.005 to 0.5% by weight.

Further, in order to adjust the pH of the recording liquid to a desired pH and to stabilize the recording liquid or the stability with the recording liquid pipe in the recording apparatus, an adjusting agent such as amine, inorganic salt, ammonia, phosphoric acid, etc. Buffer solutions such as In addition, an antifoaming agent may be added to prevent the circulation or movement of the recording liquid and the generation of bubbles during the production of the recording liquid. In order to improve the dispersion of the pigment, the following surfactants may be added and used. As such a surfactant, an anionic, nonionic, cationic or amphoteric surfactant can be used.

Examples of the anionic activator include fatty acid salt, alkyl sulfate ester salt, alkyl aryl sulfonate, alkyl naphthalene sulfonate, dialkyl sulfonate, dialkyl sulfosuccinate, alkyl diaryl ether disulfonate and alkyl phosphate. Salt, polyoxyethylene alkyl ether sulfate, polyoxyethylene alkyl aryl ether sulfate, naphthalene sulfonic acid formalin condensate, polyoxyethylene alkyl phosphate ester salt, glycerol borate fatty acid ester, polyoxyethylene glycerol fatty acid ester, etc. It can be illustrated.

As the nonionic activator, polyoxyethylene alkyl ether, polyoxyethylene alkylaryl ether, polyoxyethylene oxypropylene block copolymer, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, Examples thereof include glycerin fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene alkylamine, fluorine-based and silicon-based nonionic activators. Examples of the cationic activator include alkylamine salts, quaternary ammonium salts, alkylpyridinium salts, alkylimidazolium salts and the like. Examples of the zwitterionic activator include alkylbetaine, alkylamine oxide, phosphadylcholine and the like.

The dye may be used in such a form that there is no problem in water resistance and light resistance for the purpose of adjusting the hue of the pigment and imparting the concentration. Depending on the use of the dye, the dispersion stability of the pigment may be impaired.
Hereafter, it is necessary to limit the use to 25% by weight or less. As the dye, disperse dyes, water-insoluble dyes such as oil-soluble dyes, direct dyes, acid dyes, basic dyes and the like insolubilized by lake formation, reactive dyes, metal-containing dyes and the like are used. These dyes are preferably purified dyes from which inorganic salts have been removed.

Specifically, C.I. I. Direct Black 17, 19, 32, 51, 71, 108, 146, 15
4, 166, C.I. I. Add Black 2, 7, 24, 2
6, 31, 52, 63, 112, 118, C.I. I. Basic Black 2, C.I. I. Direct Blue 6, 2
2, 25, 71, 90, 106, C.I. I. Acid Blue 9, 22, 40, 59, 93, 102, 104, 11
3, 117, 120, 167, 229, 234, C.I.
I. Basic Blue 1, 3, 5, 7, 9, 24, 2
5, 26, 28, 29, C.I. I. Direct Red 1,
4, 17, 28, 83, C.I. I. Acid Red 1,
6, 32, 37, 51, 52, 80, 85, 87, 9
2, 94, 115, 180, 256, 315, 317.
C. I. Basic Red 1, 2, 9, 12, 13, 1
4, 37, C.I. I. Direct Yellow 12, 24, 2
6, 98, C.I. I. Acid Yellow 11, 17, 23,
25, 29, 42, 61, 71, C.I. I. Basic Yellow 11, 28. C. I. Direct Orange 34, 3
9, 44, 46, 60, C.I. I. Direct violet 47, 48, C.I. I. Direct Brown 109,
C. I. Direct Green 59, C.I. I. Acid Orange 7, 19, C.I. I. Acid Violet 49,
C. I. Basic violet 7, 14, 27, etc. can be illustrated. Other additives such as urea and dimethylurea may be added.

The ink jet recording liquid of the present invention is prepared by mixing an emulsion of pigment and rosin with water, and if necessary, an aqueous resin, an aqueous solvent and the like, and then using a sand mill, a homogenizer, a ball mill, a paint shaker, an ultrasonic disperser or the like. The dispersion treatment of the concentrated dispersion of is performed. Alternatively, after thoroughly kneading in a two-roll mill, further dispersed by a disperser such as a sand mill, and diluted appropriately with water,
Other additives can be mixed to produce a concentrate.
The mixing and stirring can be performed by a high-speed dispersing machine, an emulsifying machine or the like, in addition to the stirring with a usual stirrer using blades.

The concentrated liquid of the mixed recording liquid is sufficiently filtered with a filter having a pore size of 3 μm or less before or after dilution. Preferably, with a filter of 1.0 μm or less,
More preferably, it is filtered with a filter of 0.45 μm or less. Prior to the filtration of the filter, it is also possible to remove those with a large particle size by centrifugation, which reduces clogging in the filtration by the filter and prolongs the service life of the filter.

The recording liquid is preferably prepared as a liquid having a viscosity of 0.8 to 15 mPa · s (25 ° C.), though it depends on the type of recording device. Surface tension is 25-60 dyn /
cm is preferable, and the pH is not particularly limited, but is 4 to 12
And a weak alkalinity of 7 to 9 is preferable.

The recording liquid produced by the present invention is suitable for use as an inkjet recording liquid because it is water-based and has extremely good water resistance, and is suitable for use in the production of documents in offices, symbols, cardboard marking, numbering, and bar printing. It can be used in the field of recorded materials such as codes.

[0030]

【Example】

EXAMPLES The present invention will be described below based on examples. In the examples, "parts" means "parts by weight". [Example 1] The following raw materials were placed in a sand mill and dispersed for 3 hours to prepare a concentrated recording liquid for inkjet. Method for preparing dark color recording liquid Red pigment (Hosta Palm PINK E Hoechst) 15.0 parts Rosin emulsion (Rika Hercules D-101 stevelite ester solid content 50%) 16.0 parts Dimethylaminoethanol 0.1 parts Dispersion Agent (Emulgen 420 manufactured by Kao) 1.0 part Purified water 61.9 parts Glycerin 6.0 parts A dark recording liquid was prepared and then mixed with the following. After mixing
Filtration with a 1 μm membrane filter, followed by 0.4
A recording solution was prepared by filtering with a 5 μm membrane filter. Method for preparing recording liquid Dispersion (concentrated recording liquid) 13.5 parts Rosin emulsion (Rika Hercules D-101 steberite ester solid content 50%) 2.0 parts Dispersant (Emulgen 420 manufactured by Kao) 0.2 parts Ethylene glycol 10.0 parts Sodium omazine (Ohlin) 0.15 parts Ethylenediaminetetraacetic acid sodium salt 0.02 parts Purified water 74.13 parts

The filterability at the time of obtaining the recording liquid was evaluated, the viscosity and the average particle diameter of the obtained recording liquid were evaluated as follows, and the jetting characteristics, the printing state, and the like when the recording liquid was used, The clarity, transparency and water resistance of the recorded matter were evaluated. The results are shown in Table 1.

[Filtration] 1 mm with a diameter of 90 mm within a fixed time
The amount that can be filtered with a μm membrane filter.

[Viscosity] The viscosity was measured at 25 ° C. using a B type viscometer.

[Average Particle Size] The average particle size was measured with a laser diffraction type particle size distribution meter (“SALD-1100” manufactured by Shimadzu Corporation).

[Printing condition] This recording liquid was used as H by Epson Corporation.
It was put in a G5130 cartridge and recorded on plain paper (K, manufactured by Xerox). The printed state of the recorded matter was visually evaluated.

[Ejection characteristics] The ejection state of the nozzle during continuous printing was evaluated by the printed matter. Good: Printing can be performed accurately and continuously at a predetermined position. Defective: Despite continuous printing, a defect occurred in the middle or printing was not performed at a predetermined position.

[Water resistance] When recorded on plain paper (K, manufactured by Xerox Co., Ltd.), water drips on the recording surface, or the printed material is dried and then the ink is not bleeded when immersed in water for 1 minute. The flow of ink was visually evaluated.

[Transparency] The transparency when the ink was spread on the inkjet OHP sheet with an applicator of 1.5 mil was visually evaluated.

Example 2 Instead of PINK E of Example 1, a blue pigment, lionol blue FG-7330.
A concentrated recording liquid was prepared in the same manner as in Example 1 using (β-type copper phthalocyanine type: manufactured by Toyo Ink). Then, an inkjet recording liquid was prepared in the same manner as in Example 1. An inkjet recording liquid having excellent sharpness and transparency was obtained. The evaluation results are shown in Table 1.

[Example 3] Instead of PINK E of Example 1, a yellow pigment, lionol yellow GGTN (azo type: manufactured by Toyo Ink Co., Ltd.) was used to prepare a rosin emulsion D
A concentrated recording liquid was prepared in the same manner as in Example 1 except that -101 to D-188 (solid content of pentaerythritol ester of polymerized rosin) was used. Then, an inkjet recording liquid was prepared in the same manner as in Example 1. The evaluation results are shown in Table 1. [Comparative Example 1] The red, blue, and yellow ink jet recording liquids used in Examples 1, 2, and 3 were dispersed by adding an acrylic resin (John Cryl 62J manufactured by Johnson Polymer) instead of adding a rosin emulsion. I made it.
Visually check the vividness by spreading the color on the recording paper (Kerox X).
Both the Munsell C value was evaluated using a color machine (Σ80 manufactured by Nippon Denshoku). The evaluation results are shown in Table 1. The transparency was evaluated by visually observing the transparency when the ink was spread on the inkjet OHP sheet with a 1.5 mil applicator.

Example 4 Instead of PINK E of Example 1, a yellow pigment, Pariotor Yellow D-1819.
Concentration recording was performed in the same manner as in Example 1 except that 20 parts of (isoindolinone type: manufactured by BASF) was used and 20 parts of emulsion D-188 of rosin (solid content of pentaerythritol ester of polymerized rosin 50%) was used. A liquid was prepared. afterwards,
An ink jet recording liquid was prepared in the same manner as in Example 1. The evaluation results are shown in Table 1.

Example 5 In place of PINK E of Example 1, 20 parts of a red pigment, chromophthal red A-2B (diaminodianthranil type: CIBA), was used, and a rosin emulsion D-188 (of a polymerized rosin) was used. A concentrated recording liquid was prepared in the same manner as in Example 1 except that 30 parts of pentaerythritol ester solid content (50%) was used. Then, an inkjet recording liquid was prepared in the same manner as in Example 1. The evaluation results are shown in Table 1.

Example 6 In place of PINK E of Example 1, 15 parts of blue pigment, Rionogen Blue 6505 (Indanthrene type: manufactured by Toyo Ink), was used, and a rosin emulsion D-188 (polymerized rosin) was used. Example 1 except that 35 parts of 50% solids of pentaerythritol ester) are used.
A concentrated recording liquid was prepared in the same manner as in. Then, Example 1
An ink jet recording liquid was prepared in the same manner as in. The evaluation results are shown in Table 1.

Example 7 Eighteen parts of the red pigment, Pariotor Red L3670 (perylene type: CIBA), was used in place of PINK E of Example 1, and an emulsion D-188 of rosin (pentaerythritol of polymerized rosin) was used. A concentrated recording liquid was prepared in the same manner as in Example 1 except that 40 parts of ester solid content 50% was used. Then, an inkjet recording liquid was prepared in the same manner as in Example 1. The evaluation results are shown in Table 1.

[0045]

[Table 1]

[0046]

EFFECTS OF THE INVENTION According to the present invention, it is possible to provide a printed matter which is clearer and more excellent in transparency than the conventional pigment dispersion type and can be satisfactorily fixed without an aqueous resin. Further, according to the present invention, not only on a special recording medium but also on various recording mediums such as plain paper, a recorded matter excellent in sharpness can be obtained by containing an emulsion of rosin while using water as a medium. The recording liquid to be given could be obtained.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuharu Iida 2-3-13 Kyobashi, Chuo-ku, Tokyo Toyo Ink Mfg. Co., Ltd. (56) Reference JP-A-8-34941 (JP, A) JP-A 7-109430 (JP, A) JP-A-7-109431 (JP, A) JP-A-58-122974 (JP, A) JP-A-57-96066 (JP, A) JP-A-6-206912 (JP, A) JP 60-118770 (JP, A) JP 6-322306 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C09D 11 / 00-11 / 20

Claims (7)

(57) [Claims] 1. An emulsion of rosin in an aqueous liquid.
An ink jet recording liquid comprising an aqueous pigment dispersion prepared by dispersing an organic pigment in the presence of the above and an emulsion of rosin. 2. The particle size of the rosin emulsion is 10 n
The recording liquid for ink jet according to claim 1, which has a thickness of m to 1 μm. 3. The organic pigment is one selected from the group consisting of quinacridone type, phthalocyanine type, azo type, isoindolinone type, dianthraquinonyl red type, slene type, and perylene type. The inkjet recording liquid according to claim 1. 4. The dispersed particle size of the pigment is 0.02 to 0.2 μm.
The recording liquid for ink jet according to claim 1, wherein the recording liquid is m. 5. Organic pigment in solid content of 0.1 to 10% by weight
The ink jet recording liquid according to claim 1, comprising: 6. A viscosity of 0.8 to 15 mPa · s (25
C.) The ink jet recording liquid according to claim 1, wherein 7. An organic pigment is dispersed in the presence of an emulsion of rosin to prepare a concentrated aqueous pigment dispersion,
A method for producing an inkjet recording liquid, which comprises adding water and an additive to dilute, and filtering with a filter having a pore size of 1 μm or less.