PRINTING METHOD AND PRINTING DEVICE

Abstract

A printing method includes discharging ink to a substrate, heating a non-ink-discharged side of the substrate at T1, and heating an ink-discharged side of the substrate at T2, wherein the ink contains an organic solvent A (boiling point lower than 250 degrees C.), an organic solvent B (boiling point of 250 degrees C.), and a resin, where 0 degrees C. C≤T2−T1≤90 degrees C. is satisfied, the proportion (organic solvent A/ink) is 30 percent by mass or less, the proportion (organic solvent B/ink) is 1 to 3 percent by mass, the proportion (resin/ink) is 5 to 15 percent by mass, the ink has a viscosity of 8.0 to 11.0 mPa-s at 25 degrees C. and 5.5 to 11.0 mPa-s at 36 degrees C., and a 2.5 μL ink droplet discharged to the substrate shrinks to 0.1 μL within 10.0 seconds at 25 degrees C.

Claims

1. A printing method comprising: discharging ink to a substrate; heating a non-ink-discharged side of the substrate at a temperature of T1; and heating an ink-discharged side of the substrate at a temperature of T2, wherein the following relationship (1) is satisfied:
0 degrees C. ≤T2−T1≤90 degrees C.  Relationship (1), wherein the ink comprises: an organic solvent A having a boiling point of lower than 250 degrees C.; an organic solvent B having a boiling point of 250 degrees C. or higher; and a resin, wherein a proportion of the organic solvent A to the ink is 30 percent by mass or less, wherein a proportion of the organic solvent B to the ink is from 1 to 3 percent by mass, wherein a proportion of the resin to the ink is from 5 to 15 percent by mass, wherein the ink has a viscosity of from 8.0 to 11.0 mPa.Math.s at 25 degrees C. and from 5.5 to 11.0 mPa.Math.s at 36 degrees C., wherein a droplet of the ink having a volume of 2.5 μL discharged to the substrate shrinks to 0.1 μL or less in 10.0 seconds or less at 25 degrees C.

2. The printing method according to claim 1, wherein T1 is from 20 to 70 degrees C.

3. The printing method according to claim 1, wherein, in the heating a non-ink-discharged side, the non-ink-discharged side is heated by at least one of a heated wind heater or an infra-red heater.

4. The printing method according to claim 1, wherein the resin contains resin particles comprising at least one type of resin particles having a glass transition temperature of 0 degrees C. or lower.

5. The printing method according to claim 4, wherein the resin particles comprise urethane resin particles.

6. The printing method according to claim 4, wherein a proportion of the resin particles to the resin is from 30 to 70 percent by mass.

7. The printing method according to claim 1, wherein the organic solvent B comprises glycerin.

8. The printing method according to claim 1, wherein the ink further comprises a silicone-based surfactant.

9. The printing method according to claim 8, wherein the silicone-based surfactant comprises polyxyalkylene-modified dimethyl polysiloxane represented by the following Chemical Formula (1), ##STR00003## where m represents 0 or an integer of from 1 to 10, n represent an integer of from 1 to 5, a represents 0 or an integer of from 1 to 20, b represents 0 or an integer of from 1 to 20, R represents an alkyl or alkylene group having 1 to 10 carbon atoms, and R′ represents a hydrogen atom or an alkyl or alkylene group having 1 to 10 carbon atoms.

10. The printing method according to claim 9, wherein the silicone-based surfactant has a Hydrophilic-Lipophilic Balance value of from 8.0 to 11.5 according to Griffin's method.

11. The printing method according to claim 8, wherein a proportion of the silicone-based surfactant to the ink is from 0.5 to 1.5 percent by mass.

12. A printing device comprising: a container containing an ink; a discharging device configured to discharge the ink to a substrate, the discharging device comprising a nozzle having a discharging orifice at a nozzle surface; a first beating device configured to heat a non-ink-discharged side of the substrate at a temperature of T1; and a second beating device configured to heat an ink-discharged side of the substrate at a temperature of T2, wherein the following relationship (1) is satisfied:
0 degrees C. ≤T2−T1≤90 degrees C.  Relationship (1) wherein the ink comprises: an organic solvent A having a boiling point of lower than 250 degrees C.; an organic solvent B having a boiling point of 250 degrees C. or higher; and a resin, wherein a proportion of the organic solvent A to the ink is 30 percent by mass or less, wherein a proportion of the organic solvent B to the ink is from 1 to 3 percent by mass, wherein a proportion of the resin to the ink is from 5 to 15 percent by mass, wherein the ink has a viscosity of from 8.0 to 11.0 mPa.Math.s at 25 degrees C. and from 5.5 to 11.0 mPa.Math.s at 36 degrees C., wherein a droplet of the ink having a volume of 2.5 μL discharged to the substrate shrinks to 0.1 μL or less in 10.0 seconds or less at 25 degrees C.

Description

[0182] The printing device and the printing method of the present disclosure are described with reference to FIGS. 1 to 3.

[0183] FIG. 1 is a schematic diagram illustrating a perspective view of an example of the printing device of the present disclosure. The printing device illustrated in FIG. 1 is of a serial type. FIG. 2 is a diagram illustrating a perspective view of an example of the tank of the printing device of the present disclosure.

[0184] The printing device is an serial image forming apparatus. An image forming apparatus 400 includes a mechanical unit 420 in an exterior 401. Each ink accommodating unit (ink container) 411 of each tank 410 (410k, 410c, 410m, and 410y) for each color of black (K), cyan (C), magenta (M), and yellow (Y) is made of, for example, packaging material such as aluminum laminate film.

[0185] The ink accommodating unit 411 is housed in, for example, a plastic container housing unit 414 and L represents liquid contained in the ink accommodating unit 411. As a result, the tank 410 is used as an ink cartridge of each color.

[0186] A cartridge holder 404 is disposed on the rear side of the opening appearing when a cover 401c is opened. The tank 410 is detachably attached to the cartridge holder 404. In this configuration, each ink discharging outlet 413 of the tank 410 communicates with a discharging head 434 for each color via a supplying tube 436 for each color and the ink can be discharged from the discharging head 434 to a recording medium.

[0187] FIG. 3 is a schematic diagram illustrating the configuration of a printing device 1.

[0188] The printing device 1 is of a serial printer. As illustrated in FIG. 3, the printing device 1 includes an image forming unit 2 for printing images, a heating device 3, a roll medium accommodating unit 4, and a conveyance mechanism 5.

[0189] The roll medium accommodating unit 4 accommodates a roll medium 40 for printing. The roll medium accommodating unit 4 can accommodate the roll medium 40 having a different length along the width direction.

[0190] The roll medium 40 is not particularly limited limited and can be suitably selected to suit to a particular application. Examples include, but are not limited to, non-permeative media such as vinyl chloride (PVC), polyethylene terephthalate (PET) film, permeative media such as cloth and synthetic paper, and wall paper media made of polyester material.

[0191] The conveyance mechanism 5 constitutes a conveyor employing a roll-to-roll method.

[0192] The conveyance mechanism 5 includes a pair of nip rollers 51, a pair of driven rollers 52, and a reeling roller 53 on a conveyance route 54 of the roll medium 40.

[0193] The nip roller 51 is disposed upstream of the image forming unit 2 along a conveyance direction A indicated by an arrow in FIG. 3. The nip rollers 51 convey the roll medium 40 nipped by the rotation in accordance with the drive of motor towards the image forming unit 2.

[0194] The reeling roller 53 rotates in accordance with the drive of a motor M and reels up the roll medium 40 after printing.

[0195] The driven rollers 52 is rotationally driven in accordance with the conveyance of the roll medium 40.

[0196] The conveyance mechanism 5 includes a wheel encoder 55 for detecting the conveyance speed.

[0197] The conveyance mechanism 5 controls the conveyance speed by the motor control based on the speed detected by sampling the target value and the detected pulse from the wheel encoder 55.

[0198] The roll medium 40 accommodated in the roll medium accommodating unit 4 is conveyed to the image forming unit 2 in accordance with the rotation of the nip rollers 51 via the driven rollers 52.

[0199] The image forming unit 2 prints a target image on the roll medium 40 that has reached the image forming unit 2. The reeling roller 53 reels up the roll medium 40 in accordance with the rotation after printing.

[0200] The image forming unit 2 includes a carriage 21.

[0201] The carriage 21 is held slidable by guiding rods (guiding rail) 22.

[0202] The carriage 21 moves on the guiding rods 22 in the main scanning direction perpendicular to the conveyance direction A of the roll medium 40 in accordance with the drive of the motor M. The carriage 21 moves back and forth in the printable region of the image forming unit 2 to the roll medium 40 conveyed by the conveyance mechanism 5 in the main scanning region as the movable region in the main scanning direction.

[0203] The carriage 21 carries a printing head 20 having orifices arranged in lines for discharging droplets. The printing head 20 integrally includes a tank for supplying ink to the printing head 20. The printing head 20 may include a tank separately.

[0204] The printing head 20 serves as a liquid discharging unit and discharges ink droplets of each color of black (K), yellow (Y), magenta (M), and cyan (C) as the printing liquids of process colors. The black (K), yellow (Y), magenta (M), and cyan (C) are inks for image forming.

[0205] The image forming unit 2 includes a platen 23 for supporting the roll medium 40 below the printing head 20 when printing with the printing head 20.

[0206] The image forming unit 2 includes an encoder sheet for detecting the main scanning position of the carriage 21 along the main scanning direction of the carriage 21. The carriage 21 includes an encoder.

[0207] The image forming unit 2 detects the main scanning position of the carriage 21 by reading the encoder sheet by the encoder of the carriage 21.

[0208] The carriage 21 includes a sensor 24 for optically detecting the end of the roll medium 40 in accordance with the movement of the carriage 21. The detection signal by the sensor 24 is used for calculating the position of the end of the roll medium 40 in the main scanning direction and the width of the roll medium 40.

[0209] The heating device 3 includes a pre-heater 30, a platen heater 31 as the first heating device for use in the first heating, a drying heater 32 as the second heating device for use in the second heating, and the heated wind fan 33. Using one or both of the drying heater 32 and the heated wind fan 33 is possible. The pre-heater 30, the platen heater 31, and the drying heater 32 can be an electric heater using ceramic or nichrome wire.

[0210] The pre-heater 30 is disposed upstream of the image forming unit 2 in the conveyance direction A of the roll medium 40. The pre-heater 30 preliminarily heats the roll medium 40 the conveyance mechanism 5 is conveying.

[0211] The pre-heater 31 is disposed in the platen 23. The platen heater 31 heats the roll medium 40 where ink droplets are jetted from the nozzles of the printing head 20.

[0212] The drying heater 32 is disposed downstream of the image forming unit 2 in the conveyance direction A of the roll medium 40. The drying heater 32 keeps heating the roll medium 40 on which the image forming unit 2 has printed an image for accelerating the drying of the ink droplets on the roll medium 40.

[0213] The drying heater 33 is disposed downstream of the drying heater 32 (image forming unit 2) in the conveyance direction A of the roll medium 40. The heated wind fan 33 blows heated wind to the printed surface, ink-discharged surface, of the roll medium 40 where the ink has reached.

[0214] The heated wind fan 33 completely dries the ink on the printed surface of the roll medium 40 while decreasing the moisture in the atmosphere around the printed surface by directly blowing heated wind to the ink.

[0215] Thanks to of the heating device 3, the printing device 1 can print images on an ink-non-permeative medium such as polyvinylchloride film, polyethylene terephthalate (PET) film, and acrylic film as the roll medium 40.

[0216] The printing device 1 moves the carriage 21 back and forth within the width of the roll medium 40 and prints images one way or dual way of the movement of the carriage 21 while discharging ink from the printing head 20. Dual way printing is preferable for efficient printing. The action of discharging ink from the printing head 20 while the carriage 21 moves in the main scanning direction is counted as one scan.

[0217] The configuration of controlling the printing device 1 is described in, for example, Unexamined Japanese Patent Application Publication No. 2017-105193.

[0218] Substrate

[0219] The substrate mentioned above is not particularly limited and can be suitably selected to suit to a particular application. It includes paper substrate such as plain paler, glossy paper, and special paper, cloth for apparel such as T-shirt, and fabric.

[0220] The printing method of the present disclosure maintains a high level of coloring even for permeative substrates and provides excellent discharging stability, drying property, and abrasion resistance.

[0221] The cloth and fabric include knitted work, woven fabric, non-woven fabric, cloth and fabric made of fiber.

[0222] Specific examples of the material for use in the cloth and fabric include, but are not limited to, cellulose fiber derived from pulp, cotton, and hemp, synthetic fiber made from polyamide resin, polyacrylic resin, vinylon resin, vinylidene resin, polyvinyl alcohol, polyvinyl chloride, polyester resin, benzoate resin, polyclar, and phenol resin, natural fiber such as silk and wool, recycled fiber such as rayon fiber, cupra fiber, and lyocell fiber, semi-synthetic fiber such as acetate fiber, triacetate fiber, and promix fiber, metal fiber, glass fiber, and inorganic fiber such as rock fiber. These fibers can be used alone or in combination.

[0223] The cloth or fabric substrate can be obtained from fiber mixture of the cellulose fiber or natural fiber and the synthetic fiber mentioned above.

[0224] The permeation of the substrate mentioned above is defined by the volume change of ink discharged onto the substrate. The time taken for a droplet of ink having a volume of 2.5 μl discharged onto a permeative substrate to shrink to 0.1 μl or less is 10.0 seconds or less at 25 degrees C.

[0225] The contact angle meter for use in the evaluation of the permeation of a substrate is not particularly limited and can be suitably selected to suit to a particular application. One example is Dmo-5-1, manufactured by Kyowa Interface Science Co., LTD. For measurements, 2.5 μl of ink is extruded from a syringe equipped with a syringe needle. The ink extruded is discharged to a substrate and the volume change is measured by sessile drop method. Using a Teflon.sup.trademark syringe needle is preferable to enhance the reproducibility of measuring.

[0226] The volume of ink after the ink is placed on a substrate is calculated according to the following relationship.

[00001]$V\left(t\right)=\left(\frac{\pi {R_v\left(t\right)}^3\tan \left(\frac{{\theta }_D\left(t\right)}{2}\right)\left(3+\left({\tan \left(\frac{{\theta }_D\left(t\right)}{2}\right)}^2\right)\right)}{6}\right)$

[0227] In the relationship, V(t) represents the volume in μl of ink on a substrate at a certain time, R.sub.v(t) represents the radius in mm of the ink droplet on the substrate at the certain time, and θ.sub.D(t) represents the contact angle in radian of the ink droplet on the substrate at the certain time. Rv(t) and θ.sub.D(t) are evaluated by using a contact angle meter. In the present disclosure, θ.sub.D(t) is obtained by θ/2 method.

[0228] Having generally described preferred embodiments of this disclosure, further understanding can be obtained by reference to certain specific examples which are provided herein for the purpose of illustration only and are not intended to be limiting. In the descriptions in the following examples, the numbers represent weight ratios in parts, unless otherwise specified.

EXAMPLES

[0229] Next, embodiments of the present disclosure are described in detail with reference to Examples and Comparative Examples but are not limited thereto. In Examples, parts means parts by mass and percent means percent by mass excluding those in the evaluation criteria.

Preparation Example of Black Pigment Dispersion

[0230] A total of 11.2 g of styrene, 2.8 g of acrylic acid, 12 g of lauryl methacrylate, 4 g of polyethylene glycol methacrylate, 4 g of styrene macromer, and 0.4 g of mercapto ethanol were mixed in a flask followed by heating to 65 degrees C.

[0231] Next, a liquid mixture of 100.8 g of styrene, 25.2 g of acrylic acid, 108 g of lauryl methacrylate, 36 g of polyethylene glycol methacrylate, 60 g of hydroxyethyl methacrylate, 36 g of styrene macromer, 3.6 g of mercapto ethanol, 2.4 g of azobismethyl valeronitrile, and 18 g of methylethyl ketone was added dropwise to the flask in two and a half hours. Subsequently, a liquid mixture of 0.8 g of azobismethyl valeronitrile and 18 g of methyl ethyl ketone was added dropwise to the flask in half an hour.

[0232] After one-hour aging at 65 degrees C., 0.8 g of azobismethyl valeronitrile was added followed by aging for another hour to allow reaction. After the reaction was complete, 364 g of methylethyl ketone was added to the flask to obtain 800 g of a polymer solution A having a concentration of the solid portion of 50 percent.

[0233] Next, 28 g of the polymer solution A, 42 g of carbon black (Black Pearls 1000, manufactured by Cabot Corporation), 13.6 g of 1 mol/L potassium hydroxide solution, 20 g of methylethyl ketone, and 13.6 g of water were sufficiently stirred followed by mixing and kneading with a roll mill to obtain a paste.

[0234] The obtained paste was placed in 200 g of pure water followed by sufficient stirring.

[0235] Methylethyl ketone was removed with an evaporator followed by pressure-filtering with a polyvinylidene fluoride membrane filter having an average pore diameter of 5 μm. The moisture of the filtrate was adjusted to obtain a black pigment dispersion of styrene-acrylic-based resin-coated black pigment having a concentration of solid portion of 20 percent.

Manufacturing Example of Cyan Pigment Dispersion

[0236] A cyan pigment dispersion having a concentration of solid portion of 20 percent was obtained in the same manner as in the preparation of black pigment dispersion except that Pigment Blue 15:4 (SMART Cyan 3154BA, manufactured by Sensient Technologies Corporation) was used instead of carbon black.

[0237] Manufacturing Example of Magenta Pigment Dispersion A magenta pigment dispersion having a concentration of solid portion of 20 percent was obtained in the same manner as in the preparation of black pigment dispersion except that Pigment Red 122, manufactured by Sun Chemical Corporation, was used instead of carbon black.

Preparation Example of Yellow Pigment Dispersion

[0238] A yellow pigment dispersion having a concentration of solid portion of 20 percent was obtained in the same manner as in the preparation of black pigment dispersion except that Pigment Yellow 74 (SMART Yellow 3074BA, manufactured by Sensient Technologies Corporation) was used instead of carbon black.

Synthesis Example 1 of Polyester-based Urethane Resin Emulsion

[0239] A total of 124.4 g of polyester polyol (POLYLITE.sup.registered OD-X-2251, average molecular weight of 2,000, manufactured by DIC Corporation), 9.7 g of 2,2-dimethylol propionic acid, 29.8 g of isophorone diisocyanate, and 77.1 g of methyl ethyl ketone as an organic solvent were allowed to react in a nitrogen-substituted container equipped with a thermometer, a nitrogen gas-introducing tube, and a stirrer, using 0.06 g of dibutyltin dilaurate (DMTDL) as a catalyst. Four hours later, 30.7 g of methylethyl ketone was supplied as a diluting agent to continue the reaction. When the average molecular weight of the reaction product reached the range of from 20,000 to 60,000, 1.4 g of methanol was charged in the container to complete the reaction, so that an organic solvent solution of urethane resin was obtained. A total of 13.4 g of potassium hydroxide aqueous solution at 48 percent by mass was added to the organic solvent solution of urethane resin to neutralize the carboxyl group contained in the urethane resin. Thereafter, 715.3 g of water was added followed by sufficient stirring and aging and solvent removal, thereby obtaining a polyester-based urethane resin emulsion 1 having a solid portion of 30 percent by mass. The glass transition temperature of the polyester-based urethane resin emulsion 1 was measured, which was 74 degrees C. The volume average particle diameter was 69 nm.

Synthesis Example 2 of Polyester-based Urethane Resin Emulsion

[0240] A total of 100 g of methylethyl ketone, 345 g of polyesterpolyol (1) (which was obtained from iPA/AA=6/4 in molar ratio and EG/NPG=119 in molar ratio, where iPA=isophthalic acid, AA=adipic acid, EG=ethylene glycol, and NPG=neopentyl glycol, number average molecular weight of 2(XX), number of average functional groups=2), and 9.92 g of 2,2-dimethylol propionic acid (DMPA) were placed in a 2L reaction container equipped with a stirrer, a thermometer, a nitrogen sealing tube as a nitrogen introducing tube, and a condenser followed by uniform mixing at 60 degrees C.

[0241] Thereafter, 45.1 g oftriethylene glycol diisocyanate (TE GDl) and 0.08 g ofdioctyltin dilaurate (DOTDL) were loaded therein to allow reaction at 72 degrees C. for three hours to obtain a polyurethane solution. To this polyurethane solution, there were added 80 g of isophtharic acid (IPA), 220 g of methylethyl ketone (MEK), 3.74 g of triethanolamine (TEA), and 596 g of water for phase transfer. Subsequently, MEK and IPA were removed by a rotary evaporator to obtain polyester-based urethane resin emulsion 2. After the thus-obtained aqueous emulsion was cooled down to room temperature, deionized water and aqueous solution of sodium hydroxide were added to adjust the solution such that the solid portion thereof was 30 percent by mass and the pH was 8. The glass transition temperature of the polyester-based urethane resin emulsion 2 was measured, which was −5 degrees C. The volume average particle diameter was 88 nm.

Synthesis Example 1 of Polyether-based Urethane Resin Emulsion

[0242] A total of 100.2 g of polyether polyol (PT MG1000, average molecular weight of 1,000, manufactured by Mitsubishi Chemical Corporation), 15.7 g of 2,2-dimethylol propionic acid, 48.0 g of isophorone diisocyanate, and 77.1 g of methyl ethyl ketone as an organic solvent were allowed to react in a nitrogen-substituted container equipped with a thermometer, a nitrogen gas-introducing tube, and a stirrer, using 0.06 g of dibutyltin dilaurate (DMTDL) as a catalyst. Four hours later, 30.7 g of methyl ethyl ketone was supplied as a diluting agent to continue the reaction. When the average molecular weight of the reaction product reached the range of from 20.000 to 60,00), 1.4 g of methanol was charged in the container to complete the reaction, so that an organic solvent solution of urethane resin was obtained. A total of 13.4 g of potassium hydroxide aqueous solution at 48 percent by mass was added to the organic solvent solution of urethane resin to neutralize the carboxyl group in the urethane resin. Thereafter, 715.3 g of water was added followed by sufficient stirring and aging and solvent removal, thereby obtaining a polyether-based urethane resin emulsion having a solid portion of 30 percent by mass. The glass transition temperature of the polyether-based urethane resin emulsion was measured, which was 43 degrees C. The volume average particle diameter was 121 nm.

Synthesis Example 1 of Polycarbonate-based Urethane Resin Emulsion

[0243] A total of 1,500 g of polycarbonate diol (reaction product having a number average molecular weight (Mn) of 1,200 of 1,6-hexane diol and dimethyl carbonate), 220 g of 2,2-dimethylol propionic acid (DMPA), and 1,347 g of N-methyl pyrrolidone (NMP) were charged in a reaction container equipped with a stirrer, a reflux cooling tube, and a thermometer in a nitrogen atmosphere followed by heating to 60 degrees C. to dissolve DMPA. Thereafter, 1,223 g (5.5 mol) of isophorone diisocyanate and 2.6 g of dibutyl tin dilaurylate as a catalyst were added thereto and the resulting substance was heated to 90 degrees C. to complete urethanation reaction in five hours. An isocyanate-terminated urethane prepolymer was obtained as a result. This reaction mixture was cooled down to 80 degrees C. and 149 g of triethyl amine was admixed therewith. A total of 4,340 g of the resulting mixture was extracted and loaded in a liquid mixture of 5.400 g of water and 15 g of triethyl amine during vigorous stirring. Thereafter, 1,500 g of ice and 626 g of 35 percent aqueous solution of 2-methyl-1,5-pentane diamine were added to allow chain elongation reaction followed by distillation away of the solvent to adjust the solid portion concentration to 30 percent by mass, so that polycarbonate urethane resin emulsion 1 was obtained. The glass transition temperature of the polycarbonate-based urethane resin emulsion 1 was measured, which was 83 degrees C. The volume average particle diameter was 71 nm.

Synthesis Example 2 of Polycarbonate-based Urethane Resin Emulsion

[0244] A total of 1,500 g of polycarbonate diol (reaction product having a number average molecular weight (Mn) of 1,200 from 1,6-hexane diol and dimethyl carbonate), 220 g of 2,2-dimethylol propionic acid (DMPA), and 1,347 g ofN-methyl pyrrolidone (NMP) were charged in a reaction container equipped with a stirrer, a reflux cooling tube, and a thermometer in a nitrogen atmosphere followed by heating to 60 degrees C. to dissolve DMPA. Thereafter, 1,445 g (5.5 mol) of 4,4′-dicyclohexyl methane diisocyanate and 2.6 g of dibutyl tin dilaurylate (catalyst) were added thereto followed by heating to 90 degrees C. to complete urethanification reaction in five hours. An isocyanate-terminated urethane prepolymer was obtained as a result. This reaction mixture was cooled down to 80 degrees C. and 149 g of triethyl amine was admixed therewith. Thereafter, 4,340 g of the resulting mixture was extracted and charged in a liquid mixture of 5,400 g of water and 15 g of triethyl amine under vigorous stirring. Thereafter, 1,500 g of ice and 626 g of 35 percent aqueous solution of 2-methyl-1,5-pentane diamine were added to allow chain elongation reaction followed by distillation away of the solvent to adjust the solid portion concentration to 30 percent by mass, so that polycarbonate urethane resin emulsion 2 was obtained. The glass transition temperature of the polycarbonate-based urethane resin emulsion 2 was measured, which was 55 degrees C. The volume average particle diameter was 55 nm.

Synthesis Example 1 of Acrylic Resin Emulsion

[0245] A total of 900 g of deionized water and 1 g of sodium lauryl sulfate were charged in a reaction container equipped with a stirrer, a reflux condenser, a dripping device, and a thermometer and heated to 70 degrees C. while replacing nitrogen during stirring. While keeping the temperature inside at 70 degrees C., 4 g of potassium persulfate as polymerization initiator was added and dissolved in the container. An emulsified material preliminarily prepared by adding 365 g of styrene, 545 g of butyl acrylate, and 10 g of methacrylic acid to 450 g of deionized water, 3 g of sodium lauryl sulfate, and 20 g of acrylamide while being stirred was continuously added dropwise to the reaction solution in four hours. After the addition, the resulting solution was aged for three hours. After the thus-obtained aqueous emulsion was cooled down to room temperature, deionized water and sodium hydroxide aqueous solution were added to adjust pH to 9 to obtain an acrylic resin emulsion 1 having a concentration of solid content of 30 percent by mass. The glass transition temperature of the acrylic resin emulsion 1 was measured, which was 86 degrees C. The volume average particle diameter was 158 nm.

Synthesis Example 2 of Acrylic Resin Emulsion

[0246] A total of 900 g of deionized water and 1 g of sodium lauryl sulfate were charged in a reaction container equipped with a stirrer, a reflux condenser, a dripping device, and a thermometer and heated to 70 degrees C. while replacing nitrogen during stirring.

[0247] While keeping the temperature inside at 70 degrees C., 4 g of potassium persulfate as polymerization initiator was added and dissolved in the container. An emulsified material preliminarily prepared by adding 568 g of acrylic acid-2-ethylhexyl and 447 g of methyl methacrylate to 450 g of deionized water and 3 g of sodium lauryl sulfate while being stirred was continuously added dropwise to the reaction solution in four hours. After the addition, the resulting solution was aged for three hours. After the thus-obtained aqueous emulsion was cooled down to room temperature, deionized water and sodium hydroxide aqueous solution were added to adjust pH to 8 to obtain an acrylic resin emulsion 2 having a concentration of solid content of 30 percent by mass. The glass transition temperature of the acrylic resin emulsion 2 was measured, which was −21 degrees C. The volume average particle diameter was 152 nm.

[0248] Measuring of Glass Transition Temperature

[0249] The glass transition temperature of resin particles was measurable by DSC SYSTEM Q-2000 (manufactured by TA INSTRUMENTS. JAPAN). Specifically, a liquid dispersion of resin particle was heated and dried in an oven at 70 degrees C. for 12 hours or more and 5 g of the obtained solid content thereof was loaded in an aluminum sample container, which was placed in the measuring instrument. The glass transition temperature was measured in a nitrogen atmosphere under the following processes (1) to (4). Based on the DSC curve at the second temperature rising (process (4)), the glass transition temperature was obtained by the midpoint method. The measuring results are shown in Table 1 and Table, 2. The values of the glass transition temperature shown in Tables 1 and 2 are represented in percent.

[0250] (1) The liquid dispersion was cooled down to −70 degrees C. which was maintained five minutes

[0251] (2) The liquid dispersion was then heated to 120 degrees C. at a temperature rising rate of 10 degrees C. per minute

[0252] (3) The liquid dispersion was cooled down to −70 degrees C., which was maintained five minutes

[0253] (4) The liquid dispersion was then heated to 120 degrees C. at a temperature rising rate of 10 degrees C. per minute

[0254] Measuring Volume Average Particle Diameter

[0255] A measuring sample was diluted with pure water to a resin particle concentration of 0.01 percent by mass. The volume average particle diameter of the diluted sample was measured by using a Microtrac UPA-150, manufactured by NIKKISO CO., LTD.

[0256] Preparation Example of ink A

[0257] Deionized water was added as a balance to the following formulation so as to make the total 100 parts. The resulting substance was mixed and stirred followed by filtering with a filter having an average pore diameter of 5 μm (Minisart.sup.registered manufactured by Sartorius Stedim Biotech GmbH) to obtain ink A.

TABLE-US-00001 Ink Formulation Black pigment dispersion mentioned above: 20 parts Polyester-based urethane resin 1 having a volume average 4 parts particle diameter of 69 nm: Polycarbonate-based urethane resin emulsion 3, 5 parts TAKELAC.sup.trademark W6110, having a volume average particle diameter of 41 nm: SAG503A, silicone surfactant having an HLB value of 11, 1 part manufactured by Nissin Chemical co., ltd.: 1,3-propane diol, manufactured by DuPont de Nemours, Inc.: 3 parts 3-methyl-1,3-butane diol under the product name of isoprene 25 parts glyol, manufactured by KURARAY CO., LTD.: Glycerin, manufactured by Sakamoto Yakuhin Kogyo Co., 2 parts Ltd.: PROXEL LV, preservatives and fungicides, manufactured 0.1 parts by AVECIA GROUP:
Deionized water: balance to make the total 100 parts

[0258] Preparation Examples of Ink B to Ink P

[0259] Inks B to P were prepared in the same manner as in Preparation Example of ink A except that the ink formulation was changed to those shown in Tables 1 and 2. The contents of the resin in Tables 1 and 2 are represented in solid mass.

[0260] The details of each component in Tables 1 to 2 are as follows.

1,2-ppropanediol under the product name of propylene glycol, manufactured by ADEKA CORPORATION
1,4-butanediol, manufactured by Tokyo Chemical Industry Co. Ltd.
2,3-butanediol, manufactured by Tokyo Chemical Industry Co. Ltd.
1,5-pentanediol, manufactured by Tokyo Chemical Industry Co. Ltd.
3-methoxy-3-methyl-1-butanol, SOLFIT, manufactured by KURARAY CO., LTD.
Triethylene glycol monobutyl ether, manufactured by Tokyo Chemical Industry Co. Ltd.
SA G002, silicone-based surfactant having an HLB value of 12, manufactured by Nissin Chemical co., ltd.
SA G005, silicone-based surfactant having an HLB value of 7, manufactured by Nissin Chemical co., ltd.
TEGO Twin 4000, silicone-based surfactant, manufactured by Evonic
FS-300, fluorochemical surfactant, manufactured by E.I. du Pont de Nemours and Company
Cyan pigment dispersion
Magenta pigment dispersion
Yellow pigment dispersion
Polyester-based urethane resin 2
Polyether-based urethane resin
Polycarbonate-based urethane resin 1
Polycarbonate-based urethane resin 2
Acrylic resin emulsion 1
Acrylic resin emulsion 2

[0261] Measuring of Ink Viscosity

[0262] The viscosity of ink was measured by a viscometer RE80L, manufactured by TOKI SANGYO CO., LTD., under the following conditions. The measuring results of the viscosity of each ink were shown in Tables 1 and 2.

[0263] Measuring Conditions

Cone rotor: Standard cone rotor (0° 34′ x R24)
Amount of liquid sample: 1.2 mL
Rate of rotation: 50 rpm
Measuring time: 3 minutes
Temperature: 25 and 36 degrees C.

Example 1

[0264] Printed matter was obtained by printing on Light Fabric, polyester woven fabric, with the ink A in the ink tank carried inside Ri100, manufactured by Ricoh Co., Ltd. The printing condition was printing 100 percent gradation color beta image on a T-shirt as a substrate in “Fast mode” while heating at 55.0 degrees C. using a silicon bar heater (First Heating). Thereafter, the ink-discharged surface of the T-shirt was heated at 100.0 degrees C. for 3 minutes using a heated wind heating unit (Second Heating).

[0265] Examples 2 to 13 and Comparative Examples 1 to 6

[0266] Printing was performed in the same manner as in Example 1 except that the ink A was changed to the ink B to ink 1 as shown in Table 3 to 5.

[0267] Method of Measuring Time Taken for Ink on Substrate to Shrink to 0.1 μl

[0268] The time taken for ink on a substrate to shrink to 0.1 μl was measured for the combinations of the inks of Examples 1 to 13 and Comparative Examples 1 to 6 with the substrate. The results are shown in Tables 1 and 2.

[0269] Measuring Conditions

Device for evaluation: Dmo-5-1, manufactured by Kyowa Interface Science Co., LTD.
Measuring method: Sessile drop method
Syringe needle; Teflon.sup.trademark needle, inner diameter of 0.37 μm
Temperature: 25 degrees C.
Measuring interval: 0.1 sec.
Volume of ink droplet: 2.5 μl
Method of analyzing contact angle: θ/2 method
Substrate: Light Fabric, manufactured by Hewlett-Packard Company

[0270] Bluring, drying, and discharging stability are evaluated in Examples 1 to 13 and Comparative Examples 1 to 6. The results are shown in Tables 3 to 5.

[0271] Blurring

[0272] In Examples 1 to 13 and Comparative Examples 1 to 6, ink in which the black pigment dispersion was replaced with the cyan pigment dispersion, ink in which the cyan pigment dispersion was replaced with the magenta pigment dispersion, ink in which the magenta pigment dispersion was replaced with the yellow pigment dispersion, and ink in which the yellow pigment dispersion was replaced with the black pigment dispersion were prepared. The inks A to P and inks in which the pigment dispersions were replaced were printed. The color boundary of the obtained images was visually checked and evaluated. Grade B or above is usable for practical purpose.

[0273] Evaluation Criteria

A: Blurring at color boundary was not present at all
B: Slight blurring was present at one to five sites
C: Slight blurring was present at six to ten sites
D: Significant blurring was present, which degrades the image quality

[0274] Drying Property

[0275] Using the inkjet printer mentioned above, a solid image of an amount of attached of 1.5 g/m.sup.2 was printed. After printing, the printed matter was placed in a drier at 100 degrees C. and taken out therefrom changing the drying time. The solid portion was touched to check whether transfer occurred. The drying property was evaluated by the time taken for the solid image to dry until no transfer occurred according to the following evaluation criteria. Grade C or above is usable for practical purpose.

[0276] Evaluation Criteria

A: No transfer occurred in a drying time of less than 15 seconds
B: No transfer occurred in a drying time of from 15 to less than 30 seconds
C: No transfer occurred in a drying time of from 30 to less than 45 seconds
D: Transfer still occurred after drying for 45 second or more

[0277] Discharging Stability

[0278] A 15 cm×20 cm solid image was printed on a substrate followed by printing a chart for determining nozzle omission and counting the number of nozzle omissions. The discharging stability was evaluated based on the ratio of the number of nozzle omissions to the entire number of nozzles according to the following evaluation criteria. Grade B or above is usable for practical purpose.

[0279] Evaluation Criteria

A: 5 percent or less
B: 5 to less than 10percent
C: 10 to less than 15 percent
D: 15 percent or greater

TABLE-US-00002 TABLE 1 Composition of Ink ink set A B C D E F G H Black pigment 20 20 dispersion Cyan pigment 20 20 dispersion Magenta 20 20 pigment dispersion Yellow 20 20 pigment dispersion Polyester-based 4.0 4.0 urethane resin 1, Tg of 74 degrees C Polyester-based 6.0 5.0 5.0 urethane resin 2, Tg of −5 degrees C Polyether-based 6.0 3.0 8.0 urethane resin, Tg of 43 degrees C Polycarbonate- 6.0 5.0 based urethane resin 1, Tg of 83 degrees C Polycarbonate- 5.0 based urethane resin 2, Tg of 55 degrees C Polycarbonate- 5.0 4.0 4.0 7.0 3.0 based urethane resin 3, W6110, Tg of −20 degrees C Acrylic resin 1, Tg of 86 degrees C Acrylic resin 2, Tg of −21 degrees C Fluorochemical 1.6 surfactant, FS- 300 Silicone-based 0.8 surfactant, Twin 4000 Silicone-based 1.0 1.0 0.4 0.4 surfactant, SA G503 A Silicone-based 1.0 surfactant, SA G002 Silicone-based 1.2 surfactant, SA G005 1,2-propanediol, 8 3 boiling point of 187 degrees C 1,3- 3 3 propanediol, boiling point of 213 degrees C 1,4-butanediol, 10 5 boiling point of 230 degrees C 2,3-butanediol, 6 10 8 10 15 20 10 boiling point of 177 degrees C 1,5-pentanediol, 10 5 8 13 boiling point of 242 degrees C 3-methyl-1,3- 25 10 5 butanediol, boiling point of 205 degrees C 3-methoxy-3- 10 10 10 5 methyl-1-butanol, boiling point of 175 degrees C Glycerin, 2 2 2 1.2 2 2 2 boiliag point of 290 degrees C Triethylene 1 glycol monobutyl ether, boiling point of 278 degrees C PROXEL LV, 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 manufactured by AVECIA GROUP Highly pure Balance Balance Balance Balance Balance Balance Balance Balance water Total amount 100 100 100 100 100 100 100 100 Permeability to 2.7 2.4 2.7 1.6 2.4 1 2.6 7.2 substrate (seconds) Viscosity at 25 10 11 10 9.4 10 9.8 10 11 degrees C (mPa .Math. s) Viscosity at 36 7.4 8.1 8.3 8 8.7 7 7.3 8.6 degrees C (mPa .Math. s)

TABLE-US-00003 TABLE 2 Composition of Ink ink set I J K L M N O P Black pigment 20 20 20 dispersion Cyan pigment 20 dispersion Magenta 20 20 pigment dispersion Yellow 20 20 pigment dispersion Polyester- 2.0 2.0 8.0 4.0 based urethane resin 1, Tg of 74 degrees C Polyester-based 7.0 8.0 urethane resin 2, Tg of −5 degrees C Polyether-based 6.0 10.0 urethane resin, Tg of 43 degrees C Polycarbonate- 4.0 based urethane resin 1, Tg of 83 degrees C Polycarbonate- 4.0 based urethane resin 2, Tg of 55 degrees C Polycarbonate- 6.0 5.0 based urethane resin 3, W6110, Tg of −20 degrees C Acrylic resin 1. 6.0 2.5 Tg of 86 degrees C Acrylic resin 2. 6.0 6.0 Tg of −21 degrees C Fluorochemical 1.0 surfactant, FS- 300 Silicone-based 1.0 surfactant, Twin 4000 Silicone-based 1.0 1.0 surfactant SA G503A Silicone-based 1.6 0.8 surfactant, SA G002 Silicone-based 0.8 0.8 surfactant, SA G005 1,2-propanediol, 10 10 10 boiling point of 187 degrees C 1,3-propanediol, 10 5 10 10 10 3 boiling point of 213 degrees C 1,4-butanediol, 10 10 boiling point of 230 degrees C 2,3-butanediol, 10 10 8 boiling point of 177 degrees C 1,5-pentanediol, 3 boiling point of 242 degrees C 3-methyl- 8 20 10 21 butanediol, boiling point of 205 degrees C 3-methoxy- 8 3 5 3 3-methyl- 1-butanol, boiling point of 175 degrees C Glycerin, 2 2 2 3.5 1 2 boiling point of 290 degrees C Triethylene 1.5 1.5 glycol monobutyl ether, boding point of 278 degrees C PROXEL LV, 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 manufactured by AVECIA GROUP Highly pure Balance Balance Balance Balance Balance Balance Balance Balance water Total amount 100 101 100 100 100 100 100 100 Permeability to 1.2 1.8 2.4 0.6 1.9 1.6 0.9 22 substrate (seconds) Viscosity at 25 9.5 10 11 5.5 11 10 9.5 8.5 degrees C (mPa .Math. s) Viscosity at 36 7.1 8.3 8.4 3.7 9.1 8.5 6.7 5.5 degrees C (mPa .Math. s)

TABLE-US-00004 TABLE 3 Example 1 Example 2 Example 3 Ink A Ink B Ink C Heating temperature T1 degrees C. 55.0 55.0 40.0 in first heating Heating temperature T2 degrees C. 100.0 90.0 85.0 in second heating T2 − T1 degrees C. 45.0 35.0 45.0 Evaluation Blurring A A B result Drying A B € property Discharging A A A stability Example 4 Example 5 Example 6 Ink D Ink E Ink E Heating temperature T1 degrees C. 35.0 55.0 40.0 in first heating Heating temperature T2 degrees C. 110.0 85.0 90.0 in second heating T2 − T1 degrees C. 75.0 30.0 50.0 Evaluation Blurring B A B result Drying A B C property Discharging A B A stability

TABLE-US-00005 TABLE 4 Example 7 Example 8 Example 9 Example 10 Ink G Ink H Ink I Ink J Heating temperature T1 degrees C. 45.0 50.0 65.0 60.0 in first beating Heating temperature T2 degrees C. 110.0 95.0 70.0 100.0 in second heating T2 − T1 degrees C. 65.0 45.0 5.0 40.0 Evaluation Blurring B A A A result Drying property A B C A Discharging B A B B stability Example 11 Example 12 Example 13 Ink K Ink H Ink P Heating temperature T1 degrees C. 28.0 18.0 55.0 in first heating Heating temperature T2 degrees C. 115.0 105.0 100.0 in second heating T2 − T1 degrees C. 87.0 87.0 45.0 Evaluation Blurring B B A result Drying property A C A Discharging B A A stability

TABLE-US-00006 TABLE 5 Comparative Comparative Comparative Example 1 Example 2 Example 3 Ink L Ink M Ink N Healing temperature T1 degrees C. 40.0 55.0 30.0 in first heating Heating temperature T2 degrees C. 85.0 80.0 95.0 in second heating T2 − T1 degrees C. 45.0 25.0 65.0 Blurring C 8 D Evaluation Drying property D B D result Discharging B D B stability Comparative Comparative Comparative Example 4 Example 5 Example 6 Ink O Ink E Ink I Heating temperature T1 degrees C. 45.0 45.0 30.0 in first heating Heating temperature T2 degrees C. 60.0 40.0 125.0 in second heating T2 − T1 degrees C. 15.0 −5.0 95.0 Evaluation Blurring B B D result Drying property D D A Discharging A A C stability

[0280] Aspects of the present disclosure include, but are not limited to the following:

[0281] 1. A printing method includes discharging ink to a substrate, heating an ink-not-discharged side of the substrate at a temperature of T1, and heating an ink-discharged side of the substrate at a temperature of T2, wherein the following relationship (1) is satisfied: 0 degrees C. ≤T2−T1≤90 degrees C. Relationship (1), wherein the ink contains an organic solvent A having a boiling point of lower than 250 degrees C., an organic solvent B having a boiling point of 250 degrees C. or higher, and a resin, wherein the proportion of the organic solvent A to the ink is 30 percent by mass or less, wherein the proportion of the organic solvent B to the ink is from 1 to 3 percent by mass, wherein the proportion of the resin to the ink is from 5 to 15 percent by mass, wherein the ink has a viscosity of from 8.0 to 11.0 mPa-s at 25 degrees C., wherein the ink has a viscosity of from 5.5 to 11.0 mPa.Math.s at 36 degrees C., wherein a droplet of the ink having a volume of 2.5 μL discharged to the substrate shrinks to 0.1 μL or less in 10.0 seconds or less at 25 degrees C.

[0282] 2. The printing method according to 1 mentioned above, wherein T1 is from 20 to 70 degrees C.

[0283] 3. The method according to 1 or 2 mentioned above, wherein, in the heating an ink-not-discharged side, the ink-not-discharged side is heated by at least one of a heated wind heater or an infrared OR) heater.

[0284] 4. The printing method according any one of 1 to 3 mentioned above, wherein the resin contains resin particles containing at least one type of resin having a glass transition temperature of 0 degrees C. or lower.

[0285] 5. The printing method according to any one of 1 to 4 mentioned above, wherein the resin particles contains urethane resin particles.

[0286] 6. The method according to 4 or 5 mentioned above, wherein the proportion of the particles to the resin is from 30 to 70 percent by mass.

[0287] 7. The printing method according to any one of 1 to 6 mentioned above, wherein the organic solvent B comprises glycerin.

[0288] 8. The method according to any one of 1 to 7 mentioned above, wherein the ink further contains a silicone-based surfactant.

[0289] 9. The printing method according to 8 mentioned above, wherein the silicone-based surfactant contains polyxyalkylene-modified dimethyl polysiloxane represented by the following Chemical Formula (1).

##STR00002##

[0290] In Chemical Formula (1), m represents 0 or an integer of from 1 to 10, n represent an integer of from 1 to 5, a represents 0 or an integer of from 1 to 20, b represents 0 or an integer of from 1 to 20, R represents an alkyl or alkylene group having 1 to 10 carbon atoms, and R′ represents a hydrogen atom or an alkyl or alkylene group having 1 to 10 carbon atoms.

[0291] 10. The printing method according to 9 mentioned above, wherein the silicone-based surfactant has a Hydrophilic-Lipophilic Balance (HLB) value of from 8.0 to 11.5 according to Griffin's method.

[0292] 11. The printing method according to any one of 8 to 10 mentioned above, wherein the proportion of the silicone-based surfactant to the ink is from 0.5 to 1.5 percent by mass.

[0293] 12. A printing device includes a container containing an ink, a discharging device for discharging the ink to a substrate, the discharging device including a nozzle having a discharging orifice at a nozzle surface, a first heating device for heating the non-ink-discharged side of the substrate at a temperature of T1, and a second heating device for heating the ink-discharged side of the substrate at a temperature of T2, wherein the following relationship (1) is satisfied:0 degrees C. ≤T2−T1 90 degrees C. Relationship (1), wherein the ink contains an organic solvent A having a boiling point of lower than 250 degrees C., an organic solvent B having a boiling point of 250 degrees C. or higher, and a resin, wherein the proportion of the organic solvent A to the ink is 30 percent by mass or less, wherein the proportion of the organic solvent B to the ink is from 1 to 3 percent by mass, wherein the proportion of the resin to the ink is from 5 to 15 percent by mass, wherein the ink has a viscosity of from 8.0 to 11.0 mPa-s at 25 degrees C. and from 5.5 to 11.0 mPa-s at 36 degrees C., wherein a droplet of the ink having a volume of 2.5 μL discharged to the substrate shrinks to 0.1 μL or less in 10.0 seconds or less at 25 degrees C.

[0294] The above-described embodiments are illustrative and do not limit the present invention. Thus, numerous additional modifications and variations are possible in light of the above teachings. For example, elements and/or features of different illustrative embodiments may be combined with each other and/or substituted for each other within the scope of the present invention.