JP6381969B2 - Inkjet printing method - Google Patents

Description

  Ink-jet ink that uses inorganic pigment as a coloring material, and has excellent color development without discoloration or discoloration even when baked, and is difficult to dry when ink is ejected even if it contains a high concentration of pigment. The present invention also relates to an ink jet ink excellent in continuous dischargeability. More particularly, the present invention relates to an ink jet ink suitable for inorganic materials such as glass, ceramics such as ceramics, pots and tiles, and metals.

  Conventionally, when coloring inorganic materials such as ceramics and metals, heat resistance, stability and light resistance have been emphasized, and from these viewpoints, inorganic pigments are mainly used as coloring materials, and a method of fixing by firing is a method. It has been adopted.

  In recent years, due to sophistication of design trends, various researches have been conducted on color variations of inorganic pigments, and inorganic pigments with a good particle size with a wide color gamut have been proposed. Results have not been obtained.

  In addition, in order to use such a coloring material as an ink-jet ink, dispersion is performed until the particle diameter becomes very fine in order to prevent clogging at the nozzle, but the color developability decreases as the particle diameter becomes fine, The ink must contain a pigment at a high concentration, and the stability and drying properties of the ink have been problems.

  As a method for solving the above problems, [Patent Document 1] and [Patent Document 2] propose an ink-jet ink set which is excellent in color expression and does not cause discoloration or decoloring after firing. When the ink set is a high color developer, it is necessary to contain a pigment at a high concentration. However, from the viewpoint of easy drying, nozzle clogging is caused, resulting in poor inkjet discharge stability, affecting productivity. .

[Patent Document 3] proposes an ink jet ink set in which inorganic pigment particle diameters and specific types are combined, but none of them are deeply studied on ink jet ejection stability, and sufficient results are obtained. Not obtained.

  As described above, it is an inkjet ink that uses an inorganic pigment as a coloring material, and is excellent in color developability without being discolored or decolored even when baked, and it dries at the time of ink ejection even if it contains a high concentration of pigment. Ink-jet inks that are difficult and have excellent continuous ejection properties have not yet been established.

JP 2004-263176 A JP 2006-002100 A JP 2008-222962 A

  The object of the present invention is to solve the above-mentioned problems of the prior art, and in particular, it is an ink jet ink that uses an inorganic pigment as a colorant, and has excellent color developability without being discolored or decolored even during firing. An object of the present invention is to provide an ink-jet ink that is difficult to dry during ink ejection even if it contains a pigment at a high concentration and has excellent continuous ejection properties, an ink-jet printing method using the same, and an ink-jet printed matter.

  As a result of diligent efforts to achieve the above object, the present inventor is an ink containing an inorganic pigment, a synthetic resin, and an organic solvent, wherein the organic solvent has a boiling point of 200 ° C. or higher, and the synthetic resin has a molecular weight of 10,000. ˜200,000, and ink jet inks characterized in that the particle size of inorganic pigment is 100 to 400 nm. As a result, the present invention was completed.

That is, the present invention is (1) an ink containing an inorganic pigment, a synthetic resin and an organic solvent, wherein the organic solvent has a boiling point of 200 ° C. or higher, the molecular weight of the synthetic resin is 10,000 to 200,000, Using an inkjet ink having a particle size of 100 to 400 nm,
This is an ink jet printing method in which an image is formed on an inorganic substrate by an ink jet method and then baked.
(2) The ink-jet printing method according to (1), wherein the ink contains an inorganic pigment in a range of 10 to 50% by weight.
(3) The inkjet printing method according to any one of (1) to (2), wherein the inorganic pigment of the ink is a composite oxide inorganic pigment.
(4) The ink-jet printing method according to any one of (1) to (3), wherein the ink contains an organic solvent in a range of 30 to 89% by weight.
(5) The inkjet printing method according to any one of (1) to (4), wherein the organic solvent of the ink is a glycol ether type.
(6) The inkjet printing method according to any one of (1) to (5), wherein a surface tension of the organic solvent of the ink is 20 to 35 mN / m.
(7) The ink-jet printing method according to any one of (1) to (6), wherein the ink contains a synthetic resin in a range of 0.01 to 30% by weight.
(8) The inkjet printing method according to any one of (1) to (7), wherein the synthetic resin of the ink is an acrylic resin.
(9) The inkjet printing method according to any one of (1) to (8), wherein a decomposition residue of the synthetic resin of the ink in a 450 ° C. environment is less than 5% .

  As described above, the ink-jet ink according to the present invention is excellent in color developability, can be expressed in a wide color gamut without being discolored or decolored, and can be colored without selecting a substrate. . Furthermore, since high quality peculiar to inkjet such as density and image quality can be sufficiently expressed, inkjet prints using inorganic pigments corresponding to the recent improvement in design ability can be provided.

Hereinafter, the present invention will be described in more detail.
The coloring material used in the present invention is an inorganic pigment, and specifically comprises a metal, a metal oxide, or a metal salt. Although these are stable to heat and light, they have a property of poor color expression due to their structure and are easily decomposed by oxidation / reduction.

  Therefore, although the color gamut is generally narrowed in the inkjet printing of inorganic pigments, the present invention selects a specific organic solvent or synthetic resin even if the pigment is contained at a high concentration in order to improve color development. By adjusting the physical properties, it is possible to prevent ink drying at the nozzles and to provide an ink-jet ink excellent in continuous discharge property, and to realize a wide color gamut.

The solvent used in the present invention is assumed to be an organic solvent. In the case of an organic solvent, the selection range of the boiling point is wide and the solubility of the synthetic resin is high. Therefore, the viscosity can be easily adjusted as compared with water. If the solvent is water, a high concentration pigment ink cannot be prepared. Furthermore, ejection failure is likely to occur due to drying of the head.
In the present invention, the boiling point of the organic solvent is 200 ° C. or higher. When the boiling point is 200 ° C. or higher, drying around the nozzle can be suppressed, and stable discharge is excellent. The organic solvent is more preferably contained in the range of 30 to 89% by weight with respect to the ink. If it is less than 30% by weight, sufficient drying property cannot be obtained, and nozzle clogging may occur. On the other hand, if the amount is more than 89% by weight, the pigment cannot be contained in the ink at a high concentration and the color developability may be deteriorated.

Further, the surface tension of the organic solvent is preferably 20 to 35 mN / m from the viewpoint of stable ejection with the head. If it is lower than 20 mN / m, there is a problem that the ink tends to overflow from the surface of the recording head and the continuous ejection property is poor. If it is higher than 35 mN / m, it is difficult for the ink to penetrate into the base material, and a large amount of ink cannot be imparted, resulting in poor color developability and poor appearance after firing. In addition, the surface tension described in the text is a value measured at an ink temperature of 25 to 30 ° C. by a well-helmy method.

As the organic solvent of the present invention, the 4th class 3rd petroleums, the 4th class 4th petroleums and the like in consideration of the environment are preferable, and glycol ethers are more preferable because they are chemically stable. Examples of glycol ethers include triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, diethylene glycol dibutyl ether, diethylene glycol butyl methyl ether, triethylene glycol butyl methyl ether, tripropylene glycol dimethyl ether, and ethylene glycol monophenyl ether. Tetraethylene glycol dimethyl ether and polyethylene glycol dimethyl ether having a boiling point of 250 ° C. or higher are particularly preferable. If necessary, it is possible to add aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, fatty acid esters, and the like.

Furthermore, in the present invention, the particle diameter Di (50) in a state dispersed in the ink is set to 100 to 400 nm. If it is said range, drying with a nozzle can be prevented more and stable discharge becomes possible. The particle diameter Di (50) is a diameter in which the larger side and the smaller side of the pigment particle diameter in the ink are equivalent, and a dynamic light scattering method is an example of the measuring method. As the dynamic light scattering method, for example, measurement can be performed with a Zetasizer Nano series manufactured by Malvern Instruments Limited. If the particle size Di (50) is less than 100 nm, the color developability may be extremely lowered. Further, if the particle size Di (50) exceeds 400 nm, the ink is likely to be dried, and nozzle clogging may occur easily. Moreover, the glossiness of the surface may be impaired after firing.

Here, the inorganic pigment of the present invention is preferably contained in an amount of 10 to 50% by weight based on the ink. If the amount is less than 10% by weight, the color developability is poor, and it is necessary to increase the amount of ink applied to increase the density. However, the ink may overflow depending on the ink receiving ability of the inorganic substrate. If it exceeds 50% by weight, it is difficult to stably maintain the ink itself.

  The pigment in the present invention is preferably a complex oxide inorganic pigment from the viewpoint that decoloration and discoloration hardly occur during firing.

The yellow component of the composite oxide inorganic pigment in the present invention is preferably an antimony pigment or a zircon pigment. An antimony pigment is a pigment that can express a bright yellow color and is less likely to be discolored or decolored by firing. Specific examples include lead antimony yellow, antimony titanium chrome yellow, antimony titanium yellow, and antimony titanium nickel yellow. Zircon pigments are pigments that are less susceptible to discoloration and decoloration even under higher temperature conditions, although their color developability is slightly lower than antimony pigments. Specific examples include zircon praseodymium yellow.

  The red component of the composite oxide inorganic pigment in the present invention is preferably a tin-chromium pigment. A tin-chromium pigment is a pigment that can express a bright red color and is less likely to be discolored or decolored by firing. In addition, there is an advantage that it has a color similar to that of gold purple but is relatively inexpensive. Specifically, chromium tin malon and the like can be mentioned.

  The blue component of the composite oxide inorganic pigment in the present invention is preferably a cobalt pigment. The cobalt pigment is a pigment that can express vivid blue and hardly undergoes discoloration or decoloration upon firing. Specific examples include bitumen, cobalt blue, and cobalt aluminum blue.

  The black component of the composite oxide inorganic pigment in the present invention is preferably an iron pigment. The iron-based pigment is a pigment that can express a vivid black color and hardly undergoes discoloration or decoloration by firing. Specific examples include iron oxide, manganese ferrite black, and cobalt ferrite black. Among these, cobalt ferrite black has a high blackness and is more preferable.

  The synthetic resin used in the ink of the present invention has a molecular weight of 10,000 to 200,000. Although the viscosity can be adjusted to be suitable for the recording head by using a synthetic resin, if the molecular weight exceeds 200,000, there is a possibility that the head cannot be stably ejected. If the molecular weight is less than 10,000, the effect of adjusting the viscosity is small, and it is necessary to add a large amount of synthetic resin to the ink, which may increase the cost.

The synthetic resin is preferably contained in an amount of 0.01 to 30% by weight with respect to the ink. If it is less than 0.01% by weight, the effect of adjusting the viscosity is small, and if it is more than 30% by weight, there is a problem that a recording head discharge failure occurs or ash content tends to remain after firing.
The required performance of the synthetic resin is desirably soluble in organic solvents, and it is desirable that the ash content after firing is difficult to remain. Specifically, acrylic resins, urethane resins, polyester resins, vinyl acetate resins, etc. An acrylic resin is desirable in view of cost.
The viscosity of the inorganic pigment ink of the present invention is preferably 10 to 30 CPS at 30 ° C. from the viewpoint of continuous ejection stability.

The synthetic resin used in the ink of the present invention preferably has a decomposition residue of less than 5% in a 450 ° C. environment. If it is 5% or more, ash tends to remain after firing, which may affect the design.

  Examples of the inorganic base material used in the present invention include, but are not particularly limited to, inorganic materials such as glass, ceramics such as ceramics, pots and tiles, and metals.

The inkjet printing method of the present invention is achieved by performing ink-jet printing on an inorganic substrate using the ink of the ink set of the present invention and then firing.
As an inkjet recording method, a charge modulation method, a micro dot method, a charge ejection control method, a continuous method such as an ink mist method, a stem method, a pulse jet method, a bubble jet (registered trademark) method, an electrostatic suction method, etc. Any of the demand methods can be adopted. Further, it is possible to adopt either a line type in which the recording head is fixed and ejected onto the recording medium, or a serial type in which the recording head is moved relative to the recording medium.

  Further, glass frit can be added to the inorganic pigment ink for the purpose of providing adhesiveness. The glass frit is mainly composed of silicon dioxide, and is used with an auxiliary agent added depending on the purpose of use. Adjuvants include lithium carbonate, sodium carbonate, potassium carbonate, lead oxide, bismuth oxide, barium carbonate, strontium carbonate, calcium carbonate, magnesium carbonate, zinc oxide, aluminum oxide, aluminum hydroxide, boric acid, zirconium oxide, titanium oxide Furthermore, a mixture of natural products such as feldspar, quartzite, borax, kaolin and the like can also be added. These materials can be used alone or in a mixed form.

  Of course, it is also possible to add glass frit from the stage of inorganic pigment synthesis (hereinafter referred to as “upper”) instead of a mixture of inorganic pigment and glass frit.

  Furthermore, when dispersing an inorganic pigment, or an inorganic pigment and glass frit, or an overpaint into the ink, various surfactants can be optionally used alone or in the form of a mixture.

  Specifically, fatty acid soap, alkyl succinic acid sodium salt, alkylbenzene sulfonic acid sodium salt, alkyl naphthalene sulfonic acid sodium salt, alkyl sulfate sodium salt, polyoxyethylene alkyl ether sodium sulfate salt, dialkyl as anionic surfactant Cationic surfactants such as sulfosuccinate sodium salt, sodium alkyl phosphate, styrene maleic anhydride copolymer, olefin maleic anhydride copolymer, polyacrylamide partial hydrolyzate, acrylamide acrylate copolymer, sodium alginate Alkyltrimethylammonium chloride, alkyldimethylbenzylammonium chloride, etc. as agents, polyoxyethylene alkyl ethers, polyoxins as nonionic surfactants, etc. Polyoxyethylene alkyl allyl ethers, sorbitan fatty acid esters such as alkyl betaine amphoteric surfactant, an amide betaine. As the anionic surfactant, not only a sodium salt but also any metal salt or ammonium salt can be used.

  In addition, additives such as surface tension adjusters, viscosity adjusters, specific resistance adjusters, heat stabilizers, antioxidants, anti-reducing agents, preservatives, pH adjusters, antifoaming agents, wetting agents, etc. Of course, it is also possible to add.

  The inorganic pigment ink can be obtained by mixing the above materials, further dispersing the mixture using a dispersing machine such as a roll mill, a ball mill, a colloid mill, a jet mill, a bead mill, or a sand mill, followed by filtration.

  Furthermore, if necessary, it is possible to suppress bleeding after ink ejection landing by providing a liquid-absorbing material on the substrate as an ink receiving layer.

  Preferably, an ink-receiving layer made of glass frit is provided on the substrate to form an image free from bleeding even after printing and after baking, and further, by using an unfired glass frit as the receiving layer, an inorganic pigment and A glass film having excellent adhesion can be formed by melting and mixing the glass frit in the ink and the glass frit in the receiving layer.

  Accordingly, the glass frit used in the ink receiving layer is preferably the same as the glass frit that can be added to the ink described above, or a glass frit having a similar softening point and expansion coefficient even if different. This is because if the difference is significantly different, adhesion failure or the like occurs.

The drying application amount of the glass frit is preferably 50 to 500 g / m ² . If it is less than 50 g / m ² , ink bleeding cannot be sufficiently suppressed, and if it exceeds 500 g / m ² , the fired glass frit layer becomes too thick, and cracks may occur. is there.

  The glass frit used as the ink receiving layer is desirably a glass frit containing about 2 to 10% of cadmium in its components.

  This is because, by using a cadmium-containing glass frit in the ink receiving layer in the ink of the present invention, the color developability of the inorganic pigment after firing is significantly improved.

  Note that an adhesive may be added to the ink receiving layer as necessary. This is because there is an effect of improving workability when applying the ink receiving layer. Specifically, natural polymers such as starch, natural gum, vegetable protein, seaweed, casein, and gelatin, semi-synthetic polymers such as ether type cellulose, ester type cellulose, ether type starch, ester type starch, and processed natural gum , Polyvinyl alcohol, polyethylene glycol, polyvinyl acetate, polyvinyl butyrate resin, polyvinyl acrylate resin, polyvinyl methyl resin, cross-linked polyacrylic acid, polyacrylic acid soda, polyacrylic acid ester, polyacrylamide, sodium methacrylate, polybutadiene, polyurethane , Synthetic polymers such as polyester and polylactic acid.

  Further, it is naturally possible to add additives such as a dispersant, an antioxidant, an anti-reduction agent, and a pH adjuster to the ink receiving layer as necessary.

  In the inkjet printing method according to the present invention, it is preferable that all inorganic pigments are baked at one time. This is because if it is performed a plurality of times, a cost problem is caused and color variation is caused.

  As for the firing temperature, in general, in the case of ceramics, 700 to 850 ° C. for the upper paint method, 1100 to 1300 ° C. for 30 to 60 minutes in the case of glass, 30 to 60 minutes at 500 to 650 ° C. for glass, and In the case of firewood, it is 1 to 2 minutes in a baking furnace preheated to 750 to 850 ° C., but in actuality, considering the deformation of the base material used, the type of furnace, etc., the baking time and baking temperature are Is set.

  The glass frit used in such a case is selected from a material having an appropriate coefficient of thermal expansion and softening point with respect to the substrate. If the coefficient of thermal expansion and the softening point of the base material and the glass frit are significantly different from each other, care must be taken because adhesiveness to the base material is not sufficiently performed and adhesion failure or cracks may be caused.

  For example, in the case where the base material is a glass having a softening point near 600 ° C., the softening point of the glass frit used is selected to be near 600 ° C. or lower than the softening point of the base material, and the softening point is set to around 800 ° C. In the case of tiles and earthenware, the glass frit has a softening point of around 800 ° C. or lower.

  Next, although an Example is given and this invention is demonstrated, this invention is not necessarily limited to this Example.

[Example 1]
Materials for preparing the ink were blended according to the following formulation and dispersed using a bead mill disperser. Thereafter, impurities were removed by filtration to prepare a uniform inorganic pigment ink.

≪Ink prescription≫
Inorganic pigment 30% by weight
Dispersant: Solsperse 33000
(Japan Lubrizol Co., Ltd.) 10% by weight
Organic solvent: Hisolv MTEM
(Toho Chemical Industries Co., Ltd. glycol ether type boiling point 275 ° C. surface tension 31.8 mN / m) 50% by weight
Synthetic resin: BR-105
(Mitsubishi Rayon Co., Ltd. acrylic based molecular weight 50,000 decomposition residue 1%) 10% by weight
100% by weight
The following inorganic pigments were used.
The particle size was measured by using Zeta Sizer Nano S (dynamic light scattering method) manufactured by Malvern Instruments Limited.

≪Inorganic pigment≫
Yellow component: NF-5850 YELLOW Nikken Co., Ltd. (antimony-titanium-nickel composite oxide yellow)
As for the particle diameter after dispersion, Di (50) was 220 nm.
Red component: HS-76 MAROON Nikken Co., Ltd. (tin-chromium complex oxide based marron)
As for the particle diameter after dispersion, Di (50) was 250 nm.
Blue component: NF-2800 BLUE Nikken Co., Ltd. (cobalt-aluminum complex oxide blue)
As for the particle diameter after dispersion, Di (50) was 210 nm.
Black component: NF-650 BLACK Nikken Co., Ltd. (cobalt-ferrite composite oxide black)
As for the particle diameter after dispersion, Di (50) was 200 nm.

The ink receiving layer was formed on the tile (ceramics: glazed) according to the following procedure.
The glass frit was dry dispersed with a ball mill. Next, polyvinyl alcohol and pure water were added, kneaded in a mortar, coated on a tile using a screen, and then dried at 110 ° C. for 10 minutes to form an ink receiving layer on the substrate.

≪Prescription of ink receiving layer≫
Glass frit 32117
(Glass flux with cadmium, made by Izawa Pigments) 65% by weight
Polyvinyl alcohol (adhesive: PVA-110, manufactured by Kuraray Co., Ltd.) 5% by weight
Pure water remaining
Total 100% by weight
The above ink was used for the tile having the ink receiving layer, and recording was performed under the following decoration conditions using an ink jet printer.

≪Inkjet decoration condition≫
・ Nozzle diameter 70μm
・ Voltage 50V
・ Pulse width 15μm
・ Drive frequency 5kHz
・ Head temperature 40 ℃
・ Ink amount 200g / m ²
・ Design After each recording of each single color and each mixed color (secondary color, tertiary color, quaternary color) with a solid pattern, use a ceramic oven for firing and firing under the following conditions to achieve the desired inkjet print I got a thing.

≪Baking conditions≫
Temperature: 1150 ° C
Time: The obtained inkjet print was evaluated by the method of 45 minutes or less. Table 1 shows the results.

≪Evaluation contents≫
Continuous discharge ○ No nozzle clogging in continuous discharge for 30 minutes /
No ink overflow from the head surface
× Nozzle clogged in continuous discharge for 30 minutes /
There is ink overflow from the head surface. Dryability ○ No nozzle clogging when ink is ejected after stopping for 30 minutes
× After stopping for 30 minutes, there is nozzle clogging when ink is ejected.
× Visual appearance is poor and the image is white or ash remains. Appearance after firing ○ Glossiness is obtained by visual judgment
× Glossiness is impaired by visual judgment

[Example 2] An ink-jet printed material was prepared and evaluated in the same manner as in Example 1 except that the organic solvent used was changed to Hisolv BDB.
Organic solvent: Highsolve BDB
(Glycol ether type, boiling point 256 ° C, surface tension 24.9 mN / m, manufactured by Toho Chemical Industry Co., Ltd.)

[Example 3] An ink-jet print was prepared and evaluated in the same manner as in Example 1 except that the organic solvent used was changed to High Solve BDM.
Organic solvent: Hisolv BDM
(Glycol ether type, boiling point 212 ° C, surface tension 24.1 mN / m, manufactured by Toho Chemical Industry Co., Ltd.)

[Example 4] An ink-jet print was prepared and evaluated in the same manner as in Example 1 except that the organic solvent used was changed to Hisolv MPM.
Organic solvent: Hisolv MPM
(Glycol ether type, boiling point 294 ° C, surface tension 33.8 mN / m, manufactured by Toho Chemical Industry Co., Ltd.)

[Example 5] An ink-jet print was prepared and evaluated in the same manner as in Example 1 except that the synthetic resin used was changed to Oricox KC-1100.
Synthetic resin: Oricox KC-1100
(Kyoeisha Chemical Co., Ltd. acrylic based molecular weight 130,000 decomposition residue 1%)

[Example 6] An ink-jet printed material was prepared and evaluated in the same manner as in Example 1 except that the dispersion conditions during ink preparation were changed so that the particle size Di (50) was increased. In addition,
As for the particle size after dispersion of the yellow component, Di (50) was 300 nm.
As for the particle size after dispersion of the red component, Di (50) was 340 nm.
The particle size after dispersion of the blue component was Di (50) of 310 nm.
The particle size after dispersion of the black component was Di (50) of 320 nm.

[Comparative Example 1]
An ink jet print was prepared and evaluated in the same manner as in Example 1 except that the organic solvent used was changed to Hisolv EDE.
Organic solvent: High Solve EDE
(Glycol ether type, boiling point 189 ° C, surface tension 25.0 mN / m, manufactured by Toho Chemical Industry Co., Ltd.)

[Comparative Example 2]
An ink jet print was prepared and evaluated in the same manner as in Example 1 except that the organic solvent used was changed to Hisolv DM.
Organic solvent: Hisolv DM
(Glycol ether type, boiling point 194 ° C, surface tension 34.3 mN / m, manufactured by Toho Chemical Industry Co., Ltd.)

[Comparative Example 3]
An ink-jet print was prepared and evaluated in the same manner as in Example 1 except that the organic solvent used was changed to Hisolv MDM.
Organic solvent: Hisolv MDM
(Glycol ether type, boiling point 162 ° C, surface tension 28.1 mN / m, manufactured by Toho Chemical Industry Co., Ltd.)

[Comparative Example 4]
An ink jet print was prepared and evaluated in the same manner as in Example 1 except that the synthetic resin used was changed to Oricox KC-7000.
Synthetic resin: Oricox KC-7000
(Kyoeisha Chemical Co., Ltd. acrylic based molecular weight 300,000 degradation residue 1%)

[Comparative Example 5]
An ink jet print was prepared and evaluated in the same manner as in Example 1 except that the synthetic resin to be used was changed to Joncryl 678.
Synthetic resin: Joncryl 678
(BASF Co., Ltd. acrylic based molecular weight 80,000 decomposition residue 10%)

[Comparative Example 6]
An ink jet print was prepared and evaluated in the same manner as in Example 1 except that the dispersion conditions during ink preparation were changed so that the particle size Di (50) was increased. In addition,
The particle size after dispersion of the yellow component was Di (50) of 420 nm.
As for the particle size after dispersion of the red component, Di (50) was 460 nm.
The particle diameter after dispersion of the blue component was Di (50) of 410 nm.
The particle size after dispersion of the black component was Di (50) of 420 nm.

[Comparative Example 7]
An ink jet print was prepared and evaluated in the same manner as in Example 1 except that the dispersion conditions during ink preparation were changed so that the particle size Di (50) was reduced. In addition,
The particle diameter after dispersion of the yellow component was Di (50) of 80 nm.
The particle size after dispersion of the red component was Di (50) of 90 nm.
As for the particle size after dispersion of the blue component, Di (50) was 80 nm.
The particle size after dispersion of the black component was Di (50) of 80 nm.

As shown in Table 1, Examples 1 to 6 were excellent in continuous discharge property, drying property, coloring property, and appearance after firing.

In addition, as can be seen from the results of Examples 1 to 4 and Comparative Examples 1 to 3, when the boiling point of the organic solvent contained in the ink is 200 ° C. or more, the ink is difficult to dry around the nozzle and excellent in stable ejection properties. It was.

Claims (9)

An ink containing at least an inorganic pigment, a synthetic resin, and an organic solvent, wherein the boiling point of the organic solvent is 200 ° C. or higher, the molecular weight of the synthetic resin is 10,000 to 200,000, and the particle size of the inorganic pigment is 100 to 400 nm. Using a certain inkjet ink,
An ink jet printing method in which an image is formed on an inorganic substrate by an ink jet method and then fired.   The ink-jet printing method according to claim 1, wherein the ink contains an inorganic pigment in a range of 10 to 50% by weight.   The inkjet printing method according to claim 1, wherein the inorganic pigment of the ink is a complex oxide inorganic pigment.   The inkjet printing method according to any one of claims 1 to 3, wherein the ink contains an organic solvent in an amount of 30 to 89% by weight.   The inkjet printing method according to any one of claims 1 to 4, wherein the organic solvent of the ink is a glycol ether type.   The ink jet printing method according to any one of claims 1 to 5, wherein the organic solvent of the ink has a surface tension of 20 to 35 mN / m.   The inkjet printing method according to any one of claims 1 to 6, wherein the ink contains a synthetic resin in an amount of 0.01 to 30% by weight.   The ink jet printing method according to claim 1, wherein the synthetic resin of the ink is an acrylic resin. The inkjet printing method according to claim 1, wherein a decomposition residue of the synthetic resin of the ink in an environment of 450 ° C. is less than 5% .