JP2001115068A - Recording liquid set and method for forming image using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording liquid set capable of obtaining excellent print quality and having suitability for high speed printing and provide a method for forming images by using the same. SOLUTION: This recording liquid set consists of a liquid composition containing water or water and a water soluble organic solvent and an ink containing at least water, a colorant and a water soluble organic solvent having a solubility parameter which is 4 or more than 4 to less than 15 lower than that of the water soluble organic solvent in the aforesaid liquid composition or that of water when containing no water soluble organic compound. This method for forming images uses the aforesaid recording liquid set and comprises a process for adhering the liquid composition in the aforesaid recording liquid set on the recording medium and a process for recording the ink in the aforesaid recording liquid set on the recording medium by ejecting from an orifice depending on the recording signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a novel recording liquid set comprising a liquid composition and ink, and an image forming method using the same.

[0002]

2. Description of the Related Art Liquid or molten solid ink is discharged from nozzles, slits, porous films, etc.
A so-called inkjet printer that records on a cloth, a film, or the like has various advantages such as small size, low cost, and quietness. In particular, it can print three or four colors at a time and can easily print a full color. Widespread.

[0003] However, an ink containing a liquid as a main component, on a recording medium such as plain paper, has reduced resolution / edge sharpness and deteriorated print quality. To improve printing quality,
In general, low-permeability ink is used to suppress bleeding on paper, but the drying time of the ink is extremely slow, and high-speed printing suitability is not exhibited. There is also a method of improving the print quality by separating the functions and jetting a liquid separately. For example, JP-A-8-201
No. 61 and JP-A-9-234943 describe methods for improving the print quality by jetting a liquid for aggregating the ink colorant before or after ink printing, but these methods also improve the print quality. Although very effective, it does not show suitability for high-speed printing because of prolonged drying time.

On the other hand, in order to shorten the drying time, ink having high permeability is generally used. For example, JP-A-5-1253
No. 09 discloses a method for lowering the ink surface tension. Further, Japanese Patent Application Laid-Open No. Hei 5-19491 discloses a method of adding alcohol to ink.
Japanese Patent Application Laid-Open No. 6-256696 discloses a method of adding a surfactant to ink. These methods are effective for improving the permeability and shortening the drying time,
The printing quality is not satisfactory. As described above, the balance between the short drying time having high-speed printing suitability and the high printing quality comparable to that of a laser printer has not yet reached a satisfactory level.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and achieve the following objects. That is, the present invention provides a recording liquid capable of clearly reproducing an image on plain paper, obtaining excellent printing quality, having high-speed printing suitability, and realizing a reduced drying time on plain paper. It is an object to provide a set and an image forming method using the same.

[0006]

Means for Solving the Problems As a result of intensive studies, the present inventors first applied a liquid composition on plain paper, and set the solubility parameter of a water-soluble organic solvent in the liquid composition or the liquid composition. When no water-soluble organic solvent is contained therein, the solubility parameter of water in the liquid composition, an ink containing a water-soluble organic solvent having a solubility parameter lower by a specific value, immediately after the application of the liquid composition It has been found that by printing, both excellent printing quality and short drying time can be achieved, and the present invention has been completed.

The means for solving the above-mentioned problems are as follows. That is, <1> a liquid composition containing or containing water and a water-soluble organic solvent, and at least water, a colorant, and a solubility parameter or water solubility of a water-soluble organic solvent in the liquid composition. An ink containing a water-soluble organic solvent having a solubility parameter of 4 or more and less than 15 than the solubility parameter of water in the liquid composition when no organic solvent is contained. is there. <2> An image forming method using the recording liquid set according to <1>, wherein the step (A) of attaching a liquid composition in the recording liquid set onto a recording medium, and an ink in the recording liquid set (B) discharging the ink from an orifice in accordance with a print signal to perform printing on a print medium.

[0008] Further, means for solving the above problems include:
The following embodiments are preferred. <3> The conductivity of the liquid composition is 1 × 10 ^{−6 to} 0.
The recording liquid set according to <1>, wherein the recording liquid set is 05 S / m. <4> The solubility parameter of the water-soluble organic solvent in the liquid composition is 14 or more and 23.5 or less, and the solubility parameter of the water-soluble organic solvent in the ink is 9 or more and 12 or less. A recording liquid set according to 1> or <3>. <5> The viscosity of the liquid composition is 1 to 8 mPa · s,
The surface tension is 40 to 75 mN / m, the viscosity of the ink is 1 to 8 mPa · s, and the surface tension is 20 to 45.
The recording liquid set according to any one of <1>, <3>, and <4>, wherein the recording liquid set is mN / m. <6> The water-soluble organic solvent in the liquid composition is at least one selected from the group consisting of glycerin, ethylene glycol, thiodiethanol, and diethylene glycol, and the water-soluble organic solvent in the ink is
<1> or <3, which is at least one selected from the group consisting of diethylene glycol monobutyl ether, polyethylene glycol, and polypropylene glycol
> To <5>. <7> The ink is yellow, magenta, cyan,
<1> and <3>, which are at least one selected from the group consisting of black, red, blue, and green inks.
A recording liquid set according to any one of <1> to <6>. <8> The ratio of the application amount of the liquid composition to the application amount of the ink (liquid composition: ink) is 0.1: 1 to 1:
2. The image forming method according to <2>, wherein <9> The step of attaching the liquid composition to the recording medium in the step (A) and the step of ejecting the ink to the recording medium in the step (B) by the inkjet recording method.
2> or <8>.

The print quality is degraded when the penetration in the horizontal direction of the paper is increased, and is improved when the penetration is decreased. Also, the drying time on the paper is not the time for the liquid to actually dry but the effect of the time for the liquid to permeate the paper. Therefore, in order to shorten the drying time, it is necessary to increase the permeability. In order to balance these contradictory functions, from the viewpoint of print quality, it is necessary to suppress the permeability in the horizontal direction on the paper,
From the viewpoint of the drying time, it is necessary to increase the permeability in the vertical direction of the paper. The conventional liquid composition precipitates / aggregates the colorant, so that the vertical penetration cannot be increased. According to the present invention, the horizontal direction and the vertical direction of the paper can be controlled, and both high printing quality and short drying time can be achieved.

First, when a liquid composition containing water and a water-soluble organic solvent or containing water is applied, the liquid composition has low permeability and forms a liquid layer on paper. This layer also acts as a highly hydrophilic liquid because of its high solubility parameter. The ink to be subsequently printed is 4 to less than 15 lower than the solubility parameter of the water-soluble organic solvent in the liquid composition or the water solubility parameter in the liquid composition when no water-soluble organic solvent is contained. Since it contains a water-soluble organic solvent having a solubility parameter, it acts as a highly permeable and low hydrophilic (lipophilic) ink.
The ink and the liquid layer having a solubility parameter value difference of 4 or more and less than 15 on the paper cannot be easily diffused due to the hydrophilic / lipophilic relationship, and the liquid layer prevents the ink from penetrating in the horizontal direction of the paper. Suppress. In particular, since the liquid layer exists infinitely in the horizontal direction of the paper, the effect of suppressing permeation in the horizontal direction works very strongly. On the other hand, since only a very thin liquid layer exists in the paper vertical direction, if the highly permeable ink penetrates this liquid layer, the penetration in the vertical direction will be very fast. From the operations described above, it is possible to control the permeability of the ink on the paper separately in the horizontal and vertical directions, and it is possible to achieve both high printing quality and reduced drying time.

In the present invention, the solubility parameter is determined by comparing the solubility parameter of the water-soluble organic solvent or water contained in the liquid composition with the solubility parameter of the water-soluble organic solvent contained in the ink. By comparing the solubility parameter of the entire ink with the solubility parameter of the entire ink, the object of the present invention can be achieved by satisfying the relative relationship as in the present invention.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. [Recording liquid set] The recording liquid set of the present invention comprises a liquid composition and ink.

(Liquid composition)
Containing water and a water-soluble organic solvent, or at least water
Containing, if necessary, other components
Become. The liquid composition contains, as the other component,
Preferably, the ionic substance is not contained.
The absence of quality results in a liquid with low conductivity. Previous
The conductivity of the liquid composition is 1 × 10^-6~ 0.05S / m
Is preferably 1 × 10 ^-6~ 0.03S / m is more preferable
No. The conductivity is 1 × 10^-6If it is less than S / m, it is effective
The upper part is hard to appear, and special ions from the liquid composition
Requires the removal of toxic substances, which is costly.
I will. On the other hand, when the conductivity exceeds 0.05 S / m,
Aggregation and precipitation of the colorant in the ink may occur,
Inhibits penetration and may increase drying time. here
In the ionic substance, for example, anionic surfactant
Surfactant, cationic surfactant, amphoteric surfactant, metal salt
(Especially polyvalent cations and polyvalent metal salts), anionic coloring
Agents, cationic colorants, anionic water-soluble polymers,
And a thion-soluble water-soluble polymer. In particular, Katio
And polyvalent metal salts.

The viscosity of the liquid composition is 1 to 8 at 20 ° C.
mPa · s is preferred, and 1-4 mPa · s is more preferred. If the viscosity is more than 8 mPa · s, the ejection becomes unstable, which is not desirable. On the other hand, if the viscosity is less than 1 mPa · s, overflow of the nozzle may become a problem.

The surface tension of the liquid composition is 20
40 to 75 mN / m at 50 ° C, preferably 50 to 75 mN / m.
m is more preferred. If the surface tension is less than 40 mN / m, the spread of the ink cannot be prevented, and the effect of improving the print quality may be reduced. On the other hand, the surface tension is desirably high, but there is substantially no solvent exceeding 75 mN / m.

-Water-soluble organic solvent- The water-soluble organic solvent contained in the liquid composition is not particularly limited, but has a solubility parameter of 14 to 2 or more.
It is preferably a 3.5 water-soluble organic solvent, more preferably the solubility parameter is 15-23.5.
When the solubility parameter is less than 14, the permeability of the liquid composition becomes high, so that it is impossible to prevent the ink from spreading in the horizontal direction of the paper, and the print quality may be deteriorated. On the other hand, there is substantially no solvent whose solubility parameter exceeds 23.5.

The water-soluble organic solvent used in the present invention has the requirements specified in the present invention, that is, the solubility parameter of the water-soluble organic solvent contained in the ink, the water-soluble organic solvent contained in the liquid composition. Any combination of water-soluble organic solvents can be used as long as it meets the requirement that the solubility parameter is 4 or more and less than 15. Specific examples of the water-soluble organic solvent contained in the liquid composition or the water-soluble organic solvent contained in the ink include, for example, polyhydric alcohols and derivatives thereof such as alkyl ethers. For example, glycerin, polyethylene glycol, polypropylene glycol, diethylene glycol, diethylene glycol monobutyl ether, diethylene glycol phenyl ether, propylene glycol, propylene glycol monomethyl ether, butylene glycol, triethylene glycol, thiodiethanol, hexylene glycol, ethylene glycol, ethylene glycol methyl ether, Examples thereof include diethylene glycol methyl ether, pentanediol, hexanetriol, and trimethylolpropane. These may be used alone or in combination of two or more.

Other water-soluble organic solvents include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol,
Alcohols such as hexyl alcohol and benzyl alcohol, amides such as dimethylformamide and dimethylacetamide, ketones such as acetone and diacetone alcohol, keto alcohols, triethanolamine, diethanolamine, pyrrolidone, N-methyl-2-pyrrolidone, , 3-dimethyl-2-imidazolidinone and other high-boiling nitrogen-containing solvents, dimethylsulfoxide, diethylsulfoxide, sulfolane, thiodiethanol and other sulfur-containing solvents, glucose, maltose, amylose (dextrin), cellulose, alginic acid Sugars such as sodium and derivatives thereof, gum arabic and the like can be used, but are not limited thereto. These water-soluble organic solvents may be used alone or in combination of two or more.

Preferred solubility parameters (14-23.
The water-soluble organic solvent having 5) is preferably at least one selected from the group consisting of glycerin, ethylene glycol, thiodiethanol, and diethylene glycol.

The content of the water-soluble organic solvent contained in the liquid composition is 1 to 50% by weight based on the total weight of the liquid composition.
, And more preferably 3 to 30% by weight. If the content exceeds 50% by weight, clogging or poor jetting may occur due to an increase in viscosity.

The solubility parameter of the water-soluble organic solvent can be determined by a method of calculating from the heat of evaporation, a calculation from the refractive index, a calculation from the Kauributanol value, a calculation from the surface tension, or the like, or from a chemical composition. Any method such as calculation may be used. Solubility parameter (δ) in the present invention
Is the evaporation energy (Δe) of an atom or group of chemical structures.
This is a value calculated by calculating Fedors obtained from i) and the molar volume (Δvi). [Δ = (ΣΔei / ΣΔvi) ^1/2 ]

-Water- Water used for the liquid composition or the ink is preferably ion-exchanged water to prevent impurities from being mixed.
It is preferable to use ultrapure water, distilled water, or ultrafiltration water. Further, the liquid composition does not contain the water-soluble organic solvent and may be composed of only water.

-Other components-The liquid composition contains, as the other components, a colorant,
pH adjusters, hydrotropes, chelating agents, clathrates, oxidants, antioxidants, reducing agents, enzymes, bactericides,
Defoamers, abrasives and other additives can be added. When a coloring agent is contained, it can be used as an ink.

(Ink) The ink contains water, a colorant, and a water-soluble organic solvent, and further contains other components as necessary.

The conductivity of the ink is 0.005 to 0.5.
8 S / m is preferred, and 0.005 to 0.4 S / m is more preferred. When the conductivity is less than 0.005 S / m,
It will remove ionic substances derived from colorants,
In some cases, the optical density is lowered and color reproducibility is lowered. On the other hand, when the conductivity exceeds 0.8 S / m, problems such as nozzle clogging may occur. In the light color ink for photographic image quality, the ink conductivity may be low because the ink is diluted.

The viscosity of the ink is 1 to 8 mP at 20 ° C.
a · s is preferable, and 1 to 4 mPa · s is more preferable.
If the viscosity is more than 8 mPa · s, the ejection becomes unstable, which is not desirable. On the other hand, if the viscosity is less than 1 mPa · s, overflow of the nozzle may become a problem.

The surface tension of the ink at 20 ° C. is preferably 20 to 45 mN / m, more preferably 20 to 40 mN / m. If the surface tension is less than 20 mN / m, the added concentration of the solvent / surfactant or the like becomes high, and the ink jetting characteristics and the storage retention may be reduced. On the other hand, when the surface tension exceeds 45 mN / m, the permeability to paper is reduced, and the effect of shortening the drying time may be reduced.

-Water-soluble organic solvent- The solubility parameter of the water-soluble organic solvent in the liquid composition or, when the ink does not contain a water-soluble organic solvent, the solubility parameter of water in the liquid composition, A water-soluble organic solvent having a solubility parameter of at least 4 and less than 15 (hereinafter, may be referred to as a “specific water-soluble organic solvent”). Here, the liquid composition and the ink may each contain two or more water-soluble organic solvents. In this case, the lowest solubility parameter is compared with each other, and the difference in the solubility parameter is 4%. More than 15
It is sufficient if it is less than.

When the difference between the solubility parameters is less than 4, the effect of improving the printing quality is reduced. On the other hand, when the difference in the solubility parameter is 15 or more, the solubility parameter of the water-soluble organic solvent that can be used in the ink is 8.5 or less because even the water having the highest solubility parameter is about 23.5. However, since it is not dissolved in water and separated, the effect of improving the printing quality and the effect of shortening the drying time are not exhibited. Preferably, in the ink, the solubility parameter of the water-soluble organic solvent in the liquid composition or, when not containing a water-soluble organic solvent, a solubility parameter of 7 to 15 lower than the solubility parameter of water in the liquid composition. Water-soluble organic solvent.

Specific examples of the water-soluble organic solvent contained in the ink include water-soluble organic solvents having a solubility parameter satisfying the requirements defined in the present invention from the above-mentioned water-soluble organic solvents.

The water-soluble organic solvent contained in the ink is preferably a water-soluble organic solvent having a solubility parameter of 9 to 12, and more preferably a solubility parameter of 9 to 11. When the solubility parameter is less than 9, the ink may not be dissolved in water as the main component of the ink and may be separated. On the other hand, if the solubility parameter exceeds 12, the permeability may decrease, and the effect of shortening the drying time may decrease. However, if necessary, a solubility parameter of 9
Less than one water-soluble organic solvent or one having a solubility parameter of more than 12 may be added.

As the water-soluble organic solvent having a preferable solubility parameter (9 to 12), at least one selected from the group consisting of diethylene glycol monobutyl ether, polyethylene glycol and polypropylene glycol is preferable.

The content of the specific water-soluble organic solvent contained in the ink is preferably from 1 to 50% by weight, more preferably from 3 to 30% by weight, based on the total weight of the ink. If the content is less than 1% by weight, a moisturizing effect may not be obtained. On the other hand, if the content exceeds 50% by weight, it may not be possible to jet due to an increase in viscosity. Further, in the ink, a water-soluble organic solvent other than the specific water-soluble organic solvent (that is, less than 4 or less than the solubility parameter of the water-soluble organic solvent contained in the liquid composition, or contained in the liquid composition) Water-soluble organic solvent having a solubility parameter equal to or higher than the solubility parameter of the water-soluble organic solvent to be used), but even in that case, the content of the total water-soluble organic solvent contained in the ink Is preferably in the above range.

-Colorant- The colorant contained in the ink can be selected from water-soluble dyes and pigments. Examples of the water-soluble dye include an acid dye, a direct dye, and a cationic dye. Examples of the acid dye and the direct dye include C.I. I.
Direct Black-2, -4, -9, -11, -1
7, -19, -22, -32, -80, -151, -1
C. 54, -168, -171, -194; I. Direct Blue-1, -2, -6, -8, -22, -34,
-70, -71, -76, -78, -86, -112,
-142, -165, -199, -200, -201,
-202, -203, -207, -218, -236,
-287; I. Direct Red-1, -2,-
4, -8, -9, -11, -13, -15, -20,-
28, -31, -33, -37, -39, -51, -5
9, -62, -63, -73, -75, -80, -8
1, -83, -87, -90, -94, -95, -9
9, -101, -110, -189; I. Direct yellow-1, -2, -4, -8, -11, -12,
-26, -27, -28, -33, -34, -41,-
44, -48, -58, -86, -87, -88, -1
35, -142, -144;

C. I. Food black-1, -2;
I. Acid Black-1, -2, -7, -16, -2
4, -26, -28, -31, -48, -52, -6
3, -107, -112, -118, -119, -12
1, -156, -172, -194, -208;
I. Acid Blue-1, -7, -9, -15, -2
2, -23, -27, -29, -40, -43, -5
5, -59, -62, -78, -80, -81, -8
3, -90, -102, -104, -111, -18
5, -249, -254; I. Acid Red-
1, -4, -8, -13, -14, -15, -18,-
21, -26, -35, -37, -110, -144,
-180, -249, -257; I. Acid Yellow-1, -3, -4, -7, -11, -12, -1
3, -14, -18, -19, -23, -25, -3
4, -38, -41, -42, -44, -53, -5
5, -61, -71, -76, -78, -79, -12
2 and the like.

Examples of the cationic dye include C.I. I. Basic Yellow-1, -11, -1
3, -19, -25, -33, -36; I. Basic Red-1, -2, -9, -12, -13, -3
8, -39, -92; I. Basic Blue-1,
-3, -5, -9, -19, -24, -25, 26, 2
8 and the like. These water-soluble dyes can be used alone, but may be used in combination of two or more kinds, or adjusted to custom colors such as red, blue, and green in addition to the four primary colors of cyan, magenta, yellow, and black.

The pigments include zinc white, titanium white, chromium oxide, iron oxide, alumina white, cadmium yellow,
Inorganic pigments such as zinc sulfide, zinc chromate, yellow lead, barium sulfate, basic lead sulfate, calcium carbonate, lead white, ultramarine, calcium silicate, manganese purple, cobalt purple, navy blue, carbon black, etc., Madalake, cochineal lake, naphthol green B, Naphthol Green Y, Naphthol Yellow S, Permanent Red 4R, Hansa Yellow, Benzidine Yellow, Risor Red, Lake Red C, Lake Red D, Brilliant Carmine 6B, Bordeaux 1
0B, phthalocyanine blue, phthalocyanine green, sky blue, rhodamine lake, methyl violet lake, quinoline yellow lake, peacock blue lake, thioindigo maroon, alizarin lake, quinacridone red, perylene red, aniline black, dioxazine violet, organic fluorescent pigment, Organic pigments such as isoindolinone yellow, cobalt oxide, γ-iron oxide, metallic iron powder, magnetites such as barium ferrite, magnetic substances such as ferrites, superparamagnetic substances, other plastic pigments and metallic luster pigments, etc. Instead, any pigment may be used. In addition to the pigment, one or more known dyes may be mixed and used.

Further, the above-mentioned pigments are trade names and C.I. I. The following is an example of a pigment number. The black pigment is a carbon black pigment such as furnace black, lamp black, acetylene black, channel black and the like, for example, Raven 7000, Raven 575
0, Raven5250, Raven5000 ULT
RAII, Raven3500, Raven2000, R
aven1500, Raven1250, Raven1
200, Raven 1190 ULTRAII, Rave
n1170, Raven 1255, Raven 1080
(Manufactured by Columbia), Regal400R, Reg
al330R, Regal660R, MogulL, B
black Pearls L, Black Pearl
s 1300, Monarch 700, Monarc
h 800, Monarch 880, Monarch
900, Monarch 1000, Monarch
1100, Monarch 1300, Monarc
h 1400 (all manufactured by Cabot Corporation),

Color Black FW1, Col
or Black FW2, Color Black
FW2V, Color Black 18, Color
Black FW200, Color Black
S150, Color Black S160, Col
or Black S170, Printex35, P
printxU, PrintexV, Printex1
40U, Printex140V, Special B
black 6, Special Black 5, Sp
electrical Black 4A, Special BL
ack4 (all manufactured by Degussa), No. 25, no. Three
3, No. 40, no. 47, no. 52, no. 90
0, No. 2300, MCF-88, MA600, MA
7, MA8, and MA100 (all manufactured by Mitsubishi Chemical Corporation), but are not limited thereto.

As the cyan pigment, C.I. I. Pigme
nt Blue-1, C.I. I. Pigment Blu
e-2, C.I. I. Pigmet Blue-3, C.I.
I. Pigment Blue-15: 3, C.I. I. P
pigment Blue-15: 34, C.I. I. Pig
ment Blue-16, C.I. I. Pigment B
lu-22, C.I. I. Pigment Blue-6
0, etc., but not limited thereto.

Examples of the magenta pigment include C.I. I. Pigm
ent Red 5, C.I. I. Pigment Red
7, C.I. I. Pigment Red 12, C.I.
I. Pigment Red 48, C.I. I. Pigm
ent Red 48: 1, C.I. I. Pigment
Red 57, C.I. I. Pigment Red 11
2, C.I. I. Pigment Red 122, C.I.
I. Pigment Red 123, C.I. I. Pig
Ment Red 146, C.I. I. Pigment
Red 168, C.I. I. Pigment Red 1
84, C.I. I. Pigment Red 202, etc., but is not limited thereto.

Examples of the yellow pigment include C.I. I. Pigm
ent Yellow-1, C.I. I. Pigment
Yellow-2, C.I. I. Pigment Yellow
ow-3, C.I. I. Pigment Yellow-1
2, C.I. I. Pigment Yellow-13, C.I.
I. Pigment Yellow-14, C.I. I. P
pigment Yellow-16, C.I. I. Pigm
ent Yellow-17, C.I. I. Pigment
Yellow-73, C.I. I. Pigment Ye
low-74, C.I. I. Pigment Yellow
w-75, C.I. I. Pigment Yellow-8
3, C.I. I. Pigment Yellow-93,
C. I. Pigment Yellow-95, C.I.
I. Pigment Yellow-97, C.I. I. P
pigment yellow-98, C.I. I. Pigm
ent Yellow-114, C.I. I. Pigmen
tYellow-128, C.I. I. Pigment Y
yellow-129, C.I. I. Pigment Yel
low-151, C.I. I. Pigment Yellow
w-154 and the like, but are not limited thereto. Further, a pigment newly synthesized for the present invention may be used. Further, two or more kinds of pigments may be used by mixing, or may be used by mixing with the water-soluble dye described above.

The surface of the pigment may be treated in advance. For example, surface treatment with alcohols such as ethanol and propanol, surfactant treatment, pigment derivative treatment for replacing acidic and basic groups, pigment coating reaction treatment for coating the pigment surface with other substances, condensation reaction and graft reaction Surface chemical reaction treatment for introducing a substituent, coupling reaction treatment for surface treatment with silane coupling agent, titanate coupling agent, zirconate coupling agent, aluminate coupling agent, etc., plasma reaction treatment, CVD treatment Etc. can be performed.

Further, a pigment which can be self-dispersed in water can also be used. The self-dispersible pigment may be a pigment obtained by a known method for introducing a hydrophilic functional group on the surface of a pigment or a pigment obtained by a newly invented method. For example, oxidation treatment with an oxidizing agent such as nitric acid, permanganate, dichromate, hypochlorite, ammonium persulfate, hydrogen peroxide, ozone, treatment with a coupling agent, polymer grafting treatment, plasma treatment, etc. It is.
Further, commercially available hydrophilic treated pigments can also be used. Examples of commercially available hydrophilic pigments that can be self-dispersed in water that can be used in the present invention include, for example, MICROJET BLACK
CW-1 manufactured by Orient Chemical Industry Co., Ltd., CAB-O-
JET200 and CAB-O-JET300 manufactured by Cabot Corporation.

The water-solubilizing group contained in the surface-modified pigment may be any of nonionic, cationic and anionic, but is preferably mainly sulfonic acid, carboxylic acid, hydroxyl group or phosphoric acid. In the case of sulfonic acid, carboxylic acid, and phosphoric acid, they can be used as they are in the form of a free acid, but in order to enhance water solubility, it is preferable to use them in the form of a salt with a basic compound. Examples of the compound forming a salt include alkali metals such as sodium, potassium and lithium, aliphatic amines such as monomethylamine, dimethylamine and triethylamine, monomethanolamine, monoethanolamine, diethanolamine, triethanolamine and diisopropanolamine. Alcohol amines, ammonia and the like. Preferably, a basic compound of an alkali metal such as sodium, potassium and lithium is used. This is presumably because the basic compound of the alkali metal is a strong electrolyte and has a large effect of promoting the dissociation of the acidic group. Further, the pigment may be used after being washed and purified as necessary.

The most preferred of these colorants are
From the viewpoints of water resistance, light resistance, and stability, a self-dispersible hydrophilic treatment pigment, for example, MICROJET BLACK
CW-1 (manufactured by Orient Chemical Industry Co., Ltd.), CAB-O
-JET200, CAB-O-JET300 (manufactured by Cabot Corporation) and the like. The content of these colorants is preferably 0.1 to 15% by weight, and
-8% by weight is more preferred. If the content is less than 0.1% by weight, an effective optical density cannot be obtained and the image uniformity may be reduced, while the content is 15% by weight.
If it exceeds, it is difficult to obtain a change in optical density, and clogging tends to occur. The colorant can be contained in the liquid composition to the same extent as described above.

-Other components- The ink contains, as the other components, a dispersant, a surfactant, a pH adjuster, a polymer, a hydrotrope,
Chelating agents, inclusion compounds, oxidizing agents, antioxidants, reducing agents, enzymes, bactericides, defoamers, abrasives, and other additives can be added.

The dispersant is used to disperse the pigment, and is a homopolymer of a hydrophilic monomer component comprising a hydrophobic portion bonded to the surface of the pigment particles and a hydrophilic portion having an SO ₃ H group, or a salt thereof; Hydrophilic treatment by sulfonation of a copolymer of a monomer component and a hydrophilic monomer component having an SO ₃ H group or a salt thereof, a homopolymer of a hydrophobic monomer component, or a copolymer of two or more hydrophobic monomer components. Or a salt thereof, a homopolymer of a hydrophilic monomer component comprising a hydrophilic portion having a hydrophobic portion and an H ₃ PO ₄ group or a salt thereof, having a hydrophobic monomer component and an H ₃ PO ₄ group Copolymer of hydrophilic monomer component or salt thereof, homopolymer of hydrophilic monomer component comprising hydrophobic portion and hydrophilic portion having COOH group or salt thereof, hydrophilic monomer having hydrophobic monomer component and COOH group And a copolymer with a mer component or a salt thereof. Further, other components can be copolymerized as needed. These may be used alone or in combination of two or more. The copolymer may have any structure such as random, graft, block and the like. These salts represent onium compounds such as alkali metals, alcoholamines such as monoethanolamine, diethanolamine, and triethanolamine, ammonium ions, sulfonium ions, oxonium ions, stibonium ions, stannonium, and iodonium. However, the present invention is not limited to this.

The hydrophilic monomer component having an SO ₃ H group includes styrene sulfonic acid, styrene sulfonic acid derivative, benzene sulfonic acid, benzene sulfonic acid derivative, naphthalene sulfonic acid, naphthalene sulfonic acid derivative, toluene sulfonic acid, toluene sulfonic acid. Acid derivatives, vinyl sulfonic acid, vinyl sulfonic acid derivatives and the like. Preferred hydrophilic monomer components include vinyl sulfonic acid, vinyl sulfonic acid derivatives, naphthalene sulfonic acid, naphthalene sulfonic acid derivatives, styrene sulfonic acid, and styrene sulfonic acid derivatives.

Examples of the hydrophilic monomer component having an H ₃ PO ₄ group include a higher alkyl phosphate ester salt and a phosphate ester salt of a higher alcohol ethylene oxide adduct. Further, as the hydrophilic monomer component having a COOH group, α, β-ethylenically unsaturated carboxylic acid and its aliphatic alcohol ester, acrylic acid,
Acrylic acid derivatives, methacrylic acid, methacrylic acid derivatives, maleic acid, maleic acid derivatives, itaconic acid, itaconic acid derivatives, fumaric acid, fumaric acid derivatives and the like. Preferred hydrophilic monomer components include acrylic acid,
Acrylic acid derivatives, methacrylic acid, and methacrylic acid derivatives are exemplified.

Examples of the hydrophobic monomer component include styrene, styrene derivatives, vinyl toluene, vinyl toluene derivatives, vinyl naphthalene, vinyl naphthalene derivatives,
Butadiene, butadiene derivatives, isoprene, isoprene derivatives, ethylene, ethylene derivatives, propylene, propylene derivatives, alkyl esters of acrylic acid, alkyl esters of methacrylic acid, and the like. Preferred hydrophobic monomer components include styrene, styrene derivatives, alkyl acrylates and alkyl methacrylates. The alkyl group has 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms.

The other components include acrylamide, acrylamide derivatives, dimethylaminoethyl methacrylate, ethoxyethyl methacrylate, butoxyethyl methacrylate, ethoxytriethylene methacrylate, vinyl pyrrolidone, vinyl pyridine, alkyl ether, methoxy polyethylene glycol methacrylate, and polyethylene glycol methacrylate. And the like, and a component containing a hydroxyl group such as hydroxymethyl methacrylate, hydroxyethyl methacrylate, and vinyl alcohol.

In addition to the above, a dispersant may be prepared by addition-polymerizing a hydrophilic monomer component using a condensation polymer of an unsaturated carboxylic acid and an alcohol or glycol (polyester condensation polymer) as a hydrophobic component. In addition, carboxylic acid group-modified polyvinyl alcohol, carboxymethyl cellulose, and the like can be used, and the invention is not limited to the above description.

The weight average molecular weight of the dispersant is 3,000
0 to 20,000. The method of measuring the weight average molecular weight includes light scattering, small-angle X-ray scattering, sedimentation equilibrium, diffusion,
A value in terms of polyethylene glycol measured by an ultracentrifugation method or various types of chromatography, for example, a GPC method can be used. The content of the dispersant is 0.002 to 10% by weight based on the total weight of the ink, and preferably 0.1 to 10% by weight.
003 to 8% by weight. The content is 0.002% by weight
Below, there is no dispersion effect. On the other hand, if the content exceeds 10% by weight, the ink cannot be ejected due to an increase in the viscosity of the ink. The dispersant can be contained in the liquid composition to the same extent as described above.

The amount of the monomer component having the COOH group or a salt thereof, the SO ₃ H group or a salt thereof, the H ₃ PO ₄ group or a salt thereof is preferably 0.1 to 100 mol% based on the whole polymer. Is from 30 to 100 mol%. The corresponding acid value is 100 for a polymer having a COOH group or a salt thereof.
８００800, preferably 150-800, SO ₃ H
Group or a salt thereof, H ₃ PO ₄ group, or a polymer having a salt thereof is in the range of 100 to 500. These aqueous polymers may be used alone or in combination of two or more. The preferred ratio of the dispersant to the pigment varies depending on the particle size, specific surface area, surface structure and the like of the pigment, but generally, the pigment: aqueous polymer = 10: 8 to 1 by weight ratio.
The range is 0: 0.5.

The disperser used for dispersion is not particularly limited, and any disperser may be used. For example, colloid mill, flow jet mill, slasher mill, high speed disperser, ball mill, attritor, sand mill, sand grinder, ultra fine mill, Eiger motor mill, dyno mill, pearl mill, agitator mill, kobol mill, three rolls, two rolls There are a roll, an extruder, a kneader, a microfluidizer, a laboratory homogenizer, an ultrasonic homogenizer and the like, and these may be used alone or in combination. Also, to prevent the contamination of inorganic impurities,
It is preferable to use a dispersion method that does not use a dispersion medium, and a microfluidizer or an ultrasonic homogenizer is suitable. In order to enhance the dispersing effect, it is preferable to degas and defoam the aqueous solution used for dispersion.
The pH at the time of dispersion is preferably 9 or less.

Examples of the polymer which may be contained in the ink include acrylic resins, vinyl acetate resins, urethane resins, acryl-styrene resins, butadiene resins, styrene resins, polyester resins, and silicone resins. Resins, fluorine-based resins, acrylic silicone-based resins, and the like, and emulsions thereof.

Various known surfactants can be added to the ink for the purpose of controlling the ejection stability and improving the effect of preventing color mixing. The surfactant may be a nonionic, anionic, cationic or amphoteric surfactant, but when the colorant is an anion, nonionic, anionic and amphoteric surfactants are preferable for preventing colorant precipitation, and especially nonionic. And anionic surfactants are preferred. When the colorant is a cation, nonionic, cationic and amphoteric surfactants are preferred for preventing colorant precipitation, and nonionic and cationic surfactants are particularly preferred. Further, when a dispersant is used, it is necessary to keep the conductivity low to ensure stability, and a nonionic surfactant is particularly preferred.

Examples of the nonionic surfactant include polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, Polyoxyethylene /
Polyoxypropylene block copolymer, polyoxyethylene sorbitan fatty acid ester, fatty acid alkylolamide, acetylene glycol derivative (Sufinol) and the like can be mentioned.

Examples of the anionic surfactant include alkyl benzene sulfonate, alkyl naphthalene sulfonate, formalin condensate of alkyl naphthalene sulfonate, higher fatty acid salt, sulfate salt of higher fatty acid ester, and higher fatty acid ester. Sulfonate,
Higher alcohol ether sulfates and sulfonates, higher alkyl sulfonamides alkylcarboxylates, sulfosuccinates, ester salts thereof, alkyl phosphites, alkyl phosphates, alkyl phosphonates and esters, higher Alcohol phosphate salts and the like.

The cationic surfactant includes, for example, primary, secondary and tertiary amine salts, quaternary ammonium salts and the like. Examples of the amphoteric surfactant include betaine, sulfobetaine, and sulfate betaine. In addition, silicone surfactants such as polysiloxane polyoxyethylene adducts, fluorine surfactants such as perfluoroalkyl carboxylic acid, perfluoroalkyl sulfonic acid, and oxyethylene perfluoroalkyl ether, and natural or biosurfactants lecithin , Spiculisporic acid, rhamnolipid, saponin, cholate and the like.

These surfactants may be used alone or in combination of two or more. The content of these surfactants is 0.001 to the total ink weight.
7% by weight, preferably 0.001 to 5% by weight. If the content is less than 0.001% by weight, the effect of addition cannot be obtained. On the other hand, if the content exceeds 7% by weight, the injection characteristics deteriorate, which is not preferable.

Examples of other additives such as hydrotropes include carboxylate salts such as sodium butyrate and sodium salicylate, aromatic sulfonates such as sodium toluenesulfonate, lower alcohols such as ethyl alcohol, urea, and acetamide. And the like.

As a chelating agent as another additive, for example, ethylenediaminetetraacetic acid (EDT)
A), iminodiacetic acid (IDA), ethylenediamine-di (o-hydroxyphenylacetic acid) (EDDHA) m, nitrilotriacetic acid (NTA) dihydroxyethylglycine (DHEG), trans-1,2-cyclohexanediaminetetraacetic acid (CyDTA) ), Diethylenetriamine-
N, N, N ', N ", N",-pentaacetic acid (DTP
A), glycol ether diamine-N, N, N ',
N'-tetraacetic acid (GEDTA) and the like.

Examples of clathrates which are other additives include urea, thiourea, desoxycholic acid, bis- (N, N'-tetramethylenebenzidine), cyclophan, cyclodextrin and the like. And preferably urea and cyclodextrin.

Further, the pH can be adjusted as required. The pH of the ink is preferably 7 to 10. When the pH exceeds 10, there is an adverse effect such as corrosion, dissolution, and peeling of the head material. Examples of adjusting pH include sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium sulfate, acetate, lactate, benzoate, triethanolamine, ammonia, and 2-amino-2-methyl-1-. Alkaline such as propanol (AMP), ammonium phosphate, sodium phosphate, lithium phosphate, acetic acid, hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, propionic acid,
An organic acid or an inorganic acid such as p-toluenesulfonic acid is exemplified. In addition, other general pH buffers and good buffers may be mentioned, but not limited thereto.

[Image Forming Method] The image forming method of the present invention is an image forming method using the recording liquid set of the present invention, wherein the liquid composition in the recording liquid set is adhered to a recording medium ( A) and a step (B) of discharging ink from the orifice in the recording liquid set from an orifice according to a recording signal to perform recording on a recording medium. In particular, in the image forming method of the present invention, it is possible to apply the liquid composition onto a recording medium such as paper, and immediately print the ink on a recording image portion on the recording medium immediately after printing. It is preferable because a high effect can be obtained in shortening.

Examples of the recording medium used in the image forming method of the present invention include, but are not particularly limited to, plain paper, glossy paper, special paper, cloth, film, OHP, and the like. Plain paper such as paper and woodfree paper is particularly preferred. The range in which the liquid composition is applied onto the recording medium is applied to the entire surface of the paper. Apply only to the recorded image area. It is applied to the recording image area and around the recording image area. Apply only around the recorded image area. Although any of the above effects can be obtained, the above and the above are preferable in order to enhance the effect of improving the print quality.

The method of applying the liquid composition may be any method as long as it can be applied to the paper by a roller or a spray. However, from the viewpoints of equipment restrictions, development cost, versatility, etc., a method of spray coating by an ink jet recording method. Is preferred.
The ratio (liquid composition: ink) of the application amount of the liquid composition to the application amount of the ink is preferably 0.1: 1 to 1: 1. If the application amount of the liquid composition exceeds 1: 1 with respect to the ink, the effect of suppressing ink penetration becomes too high, and the drying time may be delayed. On the other hand, the application amount of the liquid composition is 0.1:
If it is less than 1, the effect of preventing bleeding may not be obtained.

With the ink in the recording liquid set of the present invention, good printing quality can be obtained in any system as long as it is a so-called ink jet device. For example, the present invention is suitable for inkjet recording using a thermal inkjet system, a piezo system, ultrasonic waves, an electric field, or the like. Furthermore, it is also possible to use a recording medium and an ink having a function of promoting printing fixation by heating the recording medium and the ink to 50 to 200 ° C. before and after printing, plain paper, glossy paper, special paper, cloth, film, In addition to the method of directly printing on an OHP or the like, printing may be performed on an intermediate drum, an intermediate belt, or the like, an ink image may be prepared on the intermediate drum, and then transferred and recorded on a recording medium such as paper.

[0071]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples. First, the following liquid compositions and inks were prepared, and their electrical conductivity, viscosity, and surface tension were measured. The conductivity is 20
Under an environment of 55 ° C. and 55% RH, a conductivity meter AOL-40 (D
The viscosity was measured at 20 ° C. and 55% R
The surface tension was measured using a Wilhelmy surface tensiometer in an environment of 20 ° C. and 55% RH under an environment of H at a shear rate of 1400 ⁻¹ s.

[Preparation of Liquid Composition] —Liquid 1—Pure water (solubility parameter: 23.5) 100% by weight Liquid 1 has a conductivity of 6 × 10 ⁻⁶ S / M, viscosity is 1.0
mPa · s, and the surface tension was 72.6 mN / m.

-Liquid 2-diethylene glycol (solubility parameter: 15.0) ... 15% by weight pure water ... 85% by weight The above components were sufficiently mixed to obtain a liquid composition. The conductivity of the liquid 2 is 1 × 10 ⁻⁵ S / m, and the viscosity is 1.54 mPa.
-S, surface tension was 55.4 mN / m.

-Liquid 3-Ethylene glycol (solubility parameter: 17.8) 15% by weight pure water 85% by weight The above components were sufficiently mixed to obtain a liquid composition. Liquid 3 has a conductivity of 8 × 10 ⁻⁶ S / m and a viscosity of 1.42 mPa.
-S, surface tension was 53.1 mN / m.

-Liquid 4-triethylene glycol (solubility parameter: 13.6) 15% by weight pure water 85% by weight The above components were sufficiently mixed to obtain a liquid composition. The conductivity of the liquid 4 is 8 × 10 ⁻⁶ S / m, and the viscosity is 1.63 mPa.
-S, surface tension was 49.7 mN / m.

[Preparation of Ink] Ink 1-Cabojet 300 (manufactured by Cabot) was centrifuged (8,000 rpm, 40 minutes) to obtain a pigment dispersion (pigment concentration: 14.4% by weight). . The above pigment dispersion 35 wt% diethylene glycol (solubility parameter: 15.0) 18 wt% urea ... 5% by weight Diethylene glycol monobutyl ether ... 6% by weight (solubility parameter: 10.5) Pure water 36% by weight While thoroughly mixing the above components, the pH of 1 mol / l lithium hydroxide aqueous solution was adjusted It dripped until it became 8.0.
Thereafter, the mixture was filtered under pressure with a 1 μm filter to prepare an ink. The conductivity of the ink 1 is 0.05 S / m, and the viscosity is
3.07 mPa · s and the surface tension was 29.1 mN / m.

-Ink 2-C.I. I. Direct black 168 3% by weight Ethylene glycol (solubility parameter: 17.8) 15% by weight Polyethylene glycol 600 (solubility parameter: 10.6) 5% by weight Surfactant (Pluronic PE64, manufactured by BASF) 0.2% by weight BES (good buffer) 0.5% by weight sodium hydroxide 0.3% by weight Pure water 76% by weight After sufficiently mixing the above components, the mixture was filtered under pressure through a 1 μm filter to prepare an ink. The conductivity of ink 2 is
0.61 S / m, the viscosity was 3.36 mPa · s, and the surface tension was 43.2 mN / m.

-Ink 3-A Cabojet 300 (manufactured by Cabot) was centrifuged (8,000 rpm, 40 minutes) to obtain a pigment dispersion (pigment concentration: 14.4% by weight). The above pigment dispersion 35 wt% diethylene glycol (solubility parameter: 15.0) 18 wt% urea ·········· 5% by weight Isopropyl alcohol (solubility parameter: 11.6) ··· 7% by weight pure water ······ ·············· 35% by weight While thoroughly mixing the above components, a 1 mol / l aqueous solution of lithium hydroxide is added dropwise until the pH becomes 8.0. did.
Thereafter, the mixture was filtered under pressure with a 1 μm filter to prepare an ink. The conductivity of the ink 3 is 0.06 S / m, and the viscosity is
2.93 mPa · s and the surface tension was 42.1 mN / m.

-Ink 4-Cabojet 300 (manufactured by Cabot Corporation) was subjected to centrifugal separation (8,000 rpm, 40 minutes) to obtain a pigment dispersion (pigment concentration: 14.4% by weight). The above pigment dispersion 35 wt% diethylene glycol (solubility parameter: 15.0) 13 wt% thiodiethanol (solubility parameter: 15) 2) 5 wt% polyethylene glycol 200 (solubility parameter: 12.8) 5 wt% pure water 42 wt% While thoroughly mixing the above components, a 1 mol / l aqueous solution of lithium hydroxide was added dropwise until the pH reached 8.0.
Thereafter, the mixture was filtered under pressure with a 1 μm filter to prepare an ink. The conductivity of the ink 4 is 0.04 S / m, and the viscosity is
3.29 mPa · s and the surface tension was 47.0 mN / m.

(Examples 1 to 9 and Comparative Examples 1 to 6) By the combinations shown in Table 1 below, recording liquid sets of Examples 1 to 9 and recording liquid sets of Comparative Examples 1 to 6 were obtained. With respect to each of the obtained recording liquid sets, print quality and ink drying time were evaluated as follows. Table 1 shows the evaluation results.

<Evaluation of Print Quality> Ink Jet Printer Jet Wind31 manufactured by Fuji Xerox Co., Ltd.
A prototype head was assembled in 0C, and a print test was performed on FX-L paper (manufactured by Fuji Xerox Co., Ltd.) under an environment of 20 ° C. and 55% RH. This printing test was performed by first applying a liquid composition to the entire surface of the paper at a ratio of 0.25 to the amount of ink per unit area of 0.25, and immediately thereafter printing eight-point characters with ink. The print quality was visually evaluated.・ ・ ・: No bleeding is observed in all of the kanji and hiragana.・ ・ ・: Bleeding is observed in a very small part of kanji and hiragana. Δ: Bleeding is observed in kanji and part of hiragana. ×: Bleeding is observed on the entire surface of kanji and hiragana.

<Drying time of ink on paper> 20 ° C., 55%
In an RH environment, an ink jet printer similar to the one described above was used to print 10-fold on FX-L paper (manufactured by Fuji Xerox Co., Ltd.).
A solid image having an image area ratio of 100% and a size of mm × 50 mm was prepared. At this time, the time required for the ink droplets to be visually invisible from the paper was measured. The method and amount of application of the liquid composition were performed under the same conditions as described above.

[0083]

[Table 1]

From the results in Table 1, it can be seen that the use of the recording liquid sets of the present invention of Examples 1 to 9 comprising the liquid composition and the ink satisfying the requirements specified in the present invention provides excellent print quality and drying of the ink. It is understood that high-speed printing is possible in a short time. On the other hand, when the recording liquid sets of Comparative Examples 1 to 6 each comprising a liquid composition and an ink which do not satisfy the requirements specified in the present invention are used, it is understood that the print quality is inferior.

Example 10 Using the recording liquid set of Example 4 (Liquid 2 and Ink 1), the application ratio of the liquid composition was changed (that is, the liquid composition was applied at an ink amount of 1 per unit area).
The printing quality and the ink drying time on paper were evaluated in the same manner as described above except that the ratio was changed to 0.8. Table 2 shows the results.

Example 11 Using the recording liquid set of Example 4 (Liquid 2 and Ink 1), the application ratio of the liquid composition was changed (that is, the liquid composition was applied at an ink amount of 1 per unit area).
The printing quality and the drying time of the ink on paper were evaluated in the same manner as described above except that the ratio was changed to 1.2. Table 2 shows the results.

(Comparative Example 7) No liquid composition was applied at all,
The "print quality" and the "drying time of the ink on paper" were evaluated in the same manner as described above, except that only the ink 1 was used. Table 2 shows the results.

[0088]

[Table 2]

From the results shown in Table 2, it can be seen that in Example 11, the coating amount of the liquid composition was larger than the coating amount of the ink and the drying time of the ink was slightly longer, but the printing quality was excellent. . On the other hand, in Comparative Example 7, since the liquid composition was not applied at all, the ink drying time was short, but the print quality was poor.

[0090]

According to the present invention, an image can be clearly reproduced on plain paper, excellent print quality can be obtained, high-speed printing suitability is achieved, and drying time is reduced on plain paper. Recording liquid set and an image forming method using the same can be provided.

Continued on the front page F term (reference) 2C056 FC01 2H086 BA02 BA52 BA53 BA55 BA60 4J039 AB01 AB02 BA04 BA13 BA16 BA18 BA22 BA23 BA30 BA31 BA32 BA34 BA35 BA36 BA37 BA38 BC07 BC09 BC12 BC13 BC16 BC31 BC35 BC36 BC37 BC50 BC51 BC54 BC55 BC60 BE01 BE03 BE04 BE05 BE06 BE12 EA10 EA15 EA16 EA17 EA19 EA42 GA24

Claims (2)

[Claims] 1. A liquid composition containing or containing water and a water-soluble organic solvent, and at least water, a colorant, and a solubility parameter or water solubility of a water-soluble organic solvent in the liquid composition. An ink containing a water-soluble organic solvent having a solubility parameter of at least 4 and less than 15 lower than the solubility parameter of water in the liquid composition when no organic solvent is contained. 2. An image forming method using the recording liquid set according to claim 1, wherein the step (A) of applying the liquid composition in the recording liquid set onto a recording medium includes the steps of: A step (B) of discharging ink from an orifice according to a print signal to perform printing on a print medium;
An image forming method comprising: