JPH0535740B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD OF THE INVENTION The present invention relates to an inkjet printing ink. More specifically, the present invention relates to an inkjet printing ink using a specific surfactant as a dispersant. 2. Description of the Related Art Conventionally, a so-called inkjet recording method has been known in which recording is performed by ejecting ink droplets from a minute ejection orifice. In addition, an ink has been proposed for inkjet printing of polyester cloth by dissolving the disperse dye in a solution consisting of an organic solvent, water, and a water-soluble resin that can dissolve the disperse dye, and having a surface tension of 40 dyn/cm or more ( (Japanese Patent Application Laid-Open No. 50-59108). This publication states that the method of dispersing disperse dyes in an aqueous system using a surfactant requires a large amount of surfactant;
It is stated that the surface tension of the ink is about 30 dyn/cm, making it unsuitable as an ink for ink jet printing. The present inventor first developed an inkjet printing ink that can sufficiently inkjet print synthetic fibers, etc., regardless of whether it is aqueous or organic, by using a specific surfactant. filed a patent application for (Patent Application No. 58-241343
issue). However, in the above-mentioned jet printing ink, there are problems such as blurring of the image outline of the obtained printed cloth, clogging of the nozzle, and dry adhesion around the nozzle tip. The present invention is based on the fact that, by using a specific surfactant, it is possible to sufficiently inkjet print synthetic fibers, etc., regardless of whether they are aqueous or organic. Another object of the present invention is to provide an inkjet printing ink that can obtain a printed fabric without blurring in the outline of an image and is further improved in terms of nozzle clogging and dry adhesion to the periphery of the nozzle tip. It is. Means for Solving the Problems That is, the present invention provides 1 to 30% by weight of a water-insoluble or sparingly soluble disperse dye and a general formula [] (In the formula, R ¹ and R ² represent a hydrogen atom or an α-methylbenzyl group, R ³ represents a hydrogen atom or a methyl group, and R ⁴ represents a hydrogen atom, a methyl group, or an α-methylbenzyl group. , R ¹ ,
Either one of R ² and R ⁴ represents an α-methylbenzyl group. And n is an integer from 21 to 150. The gist of the invention is an inkjet printing ink containing 0.2 to 15% by weight of a nonionic surfactant represented by the following. Examples of the water-insoluble or sparingly soluble disperse dyes used in the present invention include anthraquinone-based, azo-based, quinophthalone-based, methine-based, and heterofused ring-based disperse dyes. And, as a yellow dye, pyridone type,
Greenish dyes include pyrazolone, quinophthalone, methine, and azo dyes; magenta dyes include anthraquinone, azo, heteroazo, and methine dyes; and cyan dyes include anthraquinone. Preferably, those having a greenish color such as those based on esters, naphthoquinones, and heteroazos are used. By printing with ink jets of these three primary colors, it is possible to print in four colors, including the black obtained from these three primary colors, so-called full-color natural colors. The amount of disperse dye used in the ink of the present invention can range from 1 to 30% by weight, preferably from 3 to 15% by weight. The nonionic surfactant represented by the above general formula [] can be easily produced, for example, by reacting a mixture of meta- and para-cresol or phenol with styrene, ethylene oxide, etc., by a known method. In addition, the nonionic surfactant represented by the general formula [] can be used alone or as a mixture of two or more, and the amount used in the ink of the present invention is in the range of 0.2 to 15% by weight. can be mentioned. A preferable range is 0.5 to 10% by weight. The ink of the present invention can be prepared by combining the above-mentioned disperse dye and a nonionic surfactant represented by the general formula It can be obtained by dispersing it in a mixed solution or a mixed solution of water and a solvent that is compatible with water among these organic solvents. The ink of the present invention can be obtained by dispersing the above-mentioned disperse dye and the nonionic surfactant represented by the general formula [] in the above-mentioned solvent or solution, and the amount of the above-mentioned solvent used is 30% by weight. that's all,
A preferable range is 50 to 95% by weight. Furthermore, 50% by weight or less of an anti-drying agent, an antifoaming agent, a hydrotrope, an anionic surfactant, etc. may be added to the ink of the present invention. As anti-drying agents, ethylene glycol, propylene glycol, diethylene glycol, glycerin, 1,5-pentanediol, molecular weight
Examples include low molecular weight polyethylene glycol with a molecular weight of about 200 to 400. Examples of antifoaming agents include silicone antifoaming agents such as FS Antiform 544 (manufactured by Dow Corning Co., Ltd., trademark), pluronic antifoaming agents such as Adekanol LG-21 (manufactured by Asahi Denka Kogyo Co., Ltd., trademark), and Surfinol. 104E (manufactured by Nissin Chemical Industry Co., Ltd., trademark)
Examples include alcohol-based antifoaming agents such as . Hydrotropic agents include urea, dimethylurea, sodium toluenesulfonate, and the like. Examples of the anionic surfactant include lignin sulfonates, phenol, sulfonates of formaldehyde low condensates, and sulfonates of naphthalene/formaldehyde low condensates. Since the ink of the present invention passes through a fine nozzle with a diameter of 10 to 100 μm, even better results can be obtained by performing a filtering step after production to remove coarse particles. For example, the ink of the present invention contains a finely ground water-insoluble or sparingly soluble disperse dye, a nonionic surfactant represented by the general formula Add ionic surfactants, hydrotropes, etc. to water and use a fine grinder such as a sand grinder or paint conditioner to remove the dye from 0.005 to 10μ, preferably
It can be obtained by crushing and dispersing it into particles of 0.005 to 1μ. Effect: Due to the unique structure of the nonionic surfactant represented by the general formula [] of the present invention, the dye can be efficiently atomized with as little amount as possible, resulting in long-term dispersion stability and extremely high dyeability. . Furthermore, a nonionic surfactant represented by the general formula [] is in a solid state at room temperature and has an appropriate melting point (35 to 65
℃), it is thought that bleeding of the printed fabric is improved, and nozzle clogging and dry adhesion around the nozzle tip are also improved. Examples Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to the following Examples. The methods for testing various physical properties of the ink, the dyeing method for inkjet printing, and the methods for measuring the deep color and bleeding properties of printed fabrics in Examples and Comparative Examples are as follows. (1) Ink concentration Dilute 0.5 g of ink with water to make 100 ml of dye aqueous solution, take 1 ml of this dye aqueous solution, and dilute with 80% acetone aqueous solution (0.1% acetic acid) to make 100 ml. The absorbance at the maximum absorption wavelength, λmax, of this solution was measured and the color density was determined by relative comparison. (The comparative example was used as the standard (100).) (2) Viscosity The viscosity of the ink was measured under the following conditions using a BL type viscometer manufactured by Tokyo Keiki Seisaku Co., Ltd. Measurement temperature: 25℃ Rotor used: No. 1 Rotor rotation speed: 60 rpm (3) Particle size After over-treating the ink using viscous paper No. 60 manufactured by Toyo Paper Co., Ltd., using the following equipment , the particle size was measured. Particle size measuring device: Submicron Particle Analyzer N-4 (manufactured by Coulter) Measurement particle size range: 0.003 to 3 μ (4) Dispersion rate Transfer the ink to a 100 ml measuring cylinder, let it stand at room temperature for 7 days, and then add 10 ml from the top of each cylinder. Remove 10ml from the bottom. The absorbance at λmax of the extracted aqueous dye solution is measured according to the method described in (1) above. Then, the dispersion rate was calculated using the following formula. Absorbance of upper dye aqueous solution/absorbance of lower dye aqueous solution x 100 = dispersion rate (%) (5) Safety The following test was conducted using the ink. (a) Heating Stability and Cooling Stability The fluidity and particle stability of the ink were observed after it was kept in a constant temperature bath for 1 hour under the following temperature conditions. Heating temperature: 60°C Cooling temperature: -15°C Evaluation was made as follows. ○ Good △ ← - → × Poor (b) Stability over time The ink was stored at room temperature for 180 days, and the presence or absence of sedimentation of dye particles was observed and evaluated as follows. ○ Good △ ← - → × Poor (6) Inkjet printing method, evaluation method for bleeding of printed fabric, and dark color measurement method (a) Inkjet printing method. Add water to ink to make dye concentration 3% by weight
After printing on polyester taffeta cloth using a commercially available on-demand inkjet printing device, it was dried at 100° C. for 30 seconds. Next, this was treated with a high temperature and normal pressure steam fixation method (175°C x 7 minutes), and then reduction washing was performed to obtain a printed cloth. (b) Method for evaluating bleeding of printed fabric The outline of the image of the printed fabric obtained by method (a) of (6) above was observed under a microscope at 100 magnification, and the degree of bleeding was evaluated as follows. ○ No bleeding △ ←―→× Large bleeding (c) Dark color measurement method The surface reflectance of the printed fabric obtained by method (a) in (6) above was measured using a color difference meter (manufactured by Nippon Denshoku Kogyo Co., Ltd.). The surface reflectance of the dyed fabric obtained in the comparative example was taken as 100 (standard) and a relative value was calculated. (7) Evaluation method for nozzle clogging and dry adhesion around the nozzle tip. The following evaluation was performed using the aqueous dye solution prepared by method (a) of (6) above. (a) Evaluation method for nozzle clogging Inject 3.5 ml of dye aqueous solution into a nozzle with a diameter of 100μ.
It was fed at a rate of ml/hr and observed from the discharge status from the nozzle tip. After discharging for 1 hour, stop for 1 hour,
Discharge was performed again, and the discharge response time at this time was measured. The ejection stability was examined from the change in the ejection speed during the first hour and the change in the re-ejection speed after stopping for one hour. Nozzle clogging was evaluated from the above-mentioned ejection response time and ejection stability. Discharge stability ○ Good △ ←→× Poor discharge response time ○ 0 seconds △ ←10 seconds→× No discharge (b) Evaluation method for dry adhesion around the nozzle tip Follow method (a) in (7) above After discharging for 1 hour, stopping for 1 hour, and discharging again for 1 hour, the area around the nozzle tip was observed under a microscope with a magnification of 100, and the dry adhesion amount was evaluated as follows. Dry adhesion ○ None △ ← Small amount → × Large amount Examples 1 to 6 and Comparative Examples 1 to 3 A mixture having the following composition was ground in a sand glider at room temperature to prepare an ink. The dyes and nonionic surfactants used are shown in Table 1 below. Composition dye [shown in Table 1]
(Usage amount shown in Table 1) Nonionic surfactant [Showed in Table 1]
(Usage amount shown in Table 1) Anionic activity commentator lignin sulfonate [Reax85A Note 1] 2g Silicone antifoaming agent [Shin-Etsu Silicone KS502 Note 2] 0.05g Ethylene glycol 15g Silicic acid [Aerosil 200 Note 3] 0.1g Water Remaining amount Total 100g Note 1: Manufactured by Westvaco, trademark Note 2: Manufactured by Shin-Etsu Chemical Co., Ltd., trademark Note 3: Manufactured by Nippon Aerosil Co., Ltd., trademark

[Table] Using the ink obtained above, various physical properties of the ink, bleeding and dark color of the printed fabric, nozzle clogging and nozzle tip were evaluated according to the methods (1) to (7) above. As a result of investigating dry adhesion to the surrounding area,
As shown in Table 3, all were good. *Dye A: Quinophthalone disperse dye (powder) shown by the structural formula below. Dye B: Anthraquinone disperse dye (powder) represented by the following structural formula. **Surfactants C to G: Compounds in which styrene/ethylene oxide is added to metacresol shown in Table 2 below.

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Claims (1)

[Claims] 1 1 to 30% by weight of a disperse dye that is insoluble or poorly soluble in water and the general formula [] (In the formula, R ¹ and R ² represent a hydrogen atom or an α-methylbenzyl group, R ³ represents a hydrogen atom or a methyl group, and R ⁴ represents a hydrogen atom, a methyl group, or an α-methylbenzyl group. , R ¹ ,
Either one of R ² and R ⁴ represents an α-methylbenzyl group. And n is an integer from 21 to 150. ) An inkjet printing ink containing 0.2 to 15% by weight of a nonionic surfactant represented by: