JPH11315233A - Image formation process - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image formation process which is capable of high-speed printing and a gray level expression and can give an image excellent in printing grade, water resistance, blotting at a color boundary, etc. SOLUTION: There is provided the image formation process comprising the step A of adhering a treating fluid for an ink to a recording substrate by a jet printing system and the step B of applying a color recording ink to the recording substrate by an ink jet recording system, wherein step A can be carried out by using at least two treating fluids featured in that the ratio of the absorption coefficient of the supernatant of a mixture of one treating fluid with the ink in a weight ratio of 1:1 to that of the supernatant of a mixture of the other treating fluid with the ink in a weight ratio of 1:1 is 1:1.3 or above.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming method, and more particularly to an ink jet printing method capable of obtaining a high-speed and high-quality image on a printing material (recording medium).

[0002]

2. Description of the Related Art Conventionally, an ink jet printing method has
Low noise, low running cost, easy to downsize equipment,
It is used in printers and copiers because of easy colorization.

However, when an image is obtained on a printing material called a so-called plain paper by these printing apparatuses to which the ink-jet printing method is applied, the water resistance of the image is insufficient, or when a color image is obtained. No high-density image free from feathering and an image free from bleeding between colors could not be achieved at the same time, and a color image with good image fastness and good quality could not be obtained.

[0004] As a method for improving the water resistance of an image, an ink in which a coloring material contained in the ink has water resistance has been put to practical use in recent years. However, its water resistance is not yet sufficient, and since it is an ink that is hardly dissolved in water after drying in principle, nozzle clogging of the print head is likely to occur. There was a disadvantage that it became complicated.

[0005] In addition, a number of techniques for improving the robustness of a print substrate have been disclosed. For example, JP
JP-A-3-24486 discloses a technique in which the dyed product is post-treated to rake and fix the dye in order to enhance the wet fastness of the dyed product.

Japanese Patent Application Laid-Open No. 54-43733 discloses a method of printing using two or more components which, when they come into contact with each other, increase the ability to form a film at normal temperature or when heated, using an inkjet printing method. A printed material is obtained in which a coating film is firmly adhered by contact of each component on a printing material. JP-A-55-150396 also discloses a method of applying a water-resistant material which forms a lake with a dye after inkjet printing of an aqueous dye ink.

Japanese Patent Application Laid-Open No. 58-128862 discloses an ink jet printing method in which an image position to be printed is identified in advance, and printing is performed by superimposing a printing ink and a processing liquid. There are disclosed methods of drawing, overlaying a processing liquid on a previously drawn print ink, overlaying a print ink on a previously drawn processing liquid, and further overlaying a processing liquid. Further, similar printing methods are disclosed in JP-A-63-60783 and JP-A-64-69381. However, these documents do not disclose a head configuration or the like that is unique to an inkjet printing apparatus.

[0008]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and enables high-speed printing and gradation expression on a recording medium, reduces color boundary bleeding, print quality, and water resistance. It is an object of the present invention to provide an image forming method which gives an image excellent in properties and the like.

[0009]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the above problems can be solved by using the following means. That is, the present invention includes a step (A) of applying a treatment liquid of an ink on a recording medium by an ink jet method and a step (B) of recording an ink for recording a color on the recording medium by an ink jet recording method. And the ratio of the absorption coefficient of the supernatant liquid when the treatment liquid and the ink are mixed at a weight ratio of 1: 1 is 1:
An image forming method, wherein the step (A) is performed using at least two or more kinds of processing liquids of 1.3 or more.

It is preferable that the at least two or more processing solutions contain at least one cationic substance at different concentrations. Preferably, the cationic substance is a cationic surfactant. Preferably, the cationic substance is polyallylamine. Preferably, the cationic substance comprises a cationic surfactant and polyallylamine.

In the image forming method, the step (A) is performed prior to the step (B), the step (A) is performed after the step (B), or the step (A) is performed after the step (B) is performed.
And then the step (B) is preferred. It is preferable that the recording of one pixel of the ink for recording the color is performed by a plurality of nozzle rows. It is preferable that the treatment liquid is attached to the recording medium by a plurality of nozzle rows.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The image forming method of the present invention comprises a step (A) of applying a treatment liquid to a recording medium of an ink for recording a color by an ink jet method, and an ink comprising a liquid composition as a coloring material. (B) on a recording medium by an ink jet recording method, and when the treatment liquid and the ink are mixed at a weight ratio of 1: 1, the ratio of the absorption coefficient of the supernatant liquid is 1: 1. Step (A) is performed using at least two or more types of processing liquids that are three or more, that is, at least two types of processing liquids having different cohesive properties on a recording medium and simultaneously imparting water resistance to a coloring material The step (A) is performed using at least one kind of processing liquid.

Further, the present invention is further characterized by an image forming method in which the at least two or more kinds of processing solutions contain at least one kind of cationic substance at different concentrations.
Also, the present invention is characterized in that the cationic substance is a cationic surfactant or polyallylamine, and that the cationic substance is a cationic surfactant and polyallylamine.

Further, when the treatment liquid is applied to the recording medium by an ink jet method, the number of pixels of the treatment liquid is smaller than the number of image pixels recorded by ink for recording a color, and the step (A). Is performed prior to the step (B), the step (A) is performed after the step (B), and the recording of one pixel of the ink for recording the color is performed by a plurality of nozzle rows. It is also characterized in that the treatment liquid is applied to the recording medium by using a plurality of nozzle rows, and that the step (A) is performed after the step (B) is performed, and then the step (B) is performed thereafter. Things.

In the present invention, when the processing liquid and the ink are mixed at a weight ratio of 1: 1, the ratio of the absorption coefficient of the supernatant liquid is 1: 1.
The method of performing the step (A) using at least two or more kinds of processing liquids having a ratio of 1.3 or more, preferably 1: 1.3 to 2.0, specifically includes different treatments depending on image information. A liquid is used. Of course, a treatment liquid having high cohesion is used in a region where high concentration is desirable, and a treatment liquid having low cohesion is used in a region where low concentration is desirable.

The absorption coefficient is determined by treating the processing liquid and the ink in a weight ratio of 1:
After mixing for 1 and standing for a certain period of time, the supernatant was collected,
This is a value obtained by measuring the absorption coefficient at the peak frequency of the ink with a spectrophotometer.

According to the present invention, a recording medium (recording material)
This makes it possible to easily perform upward gradation expression, and at the same time, to further impart water resistance and bleed resistance. The reason is presumed as follows. The image quality is simply improved by using at least two kinds of processing liquids each having an absorption coefficient ratio of the supernatant liquid of 1: 1.3 or more when the processing liquid and the ink are mixed at a weight ratio of 1: 1. In addition, since the permeability differs, it is possible to control the degree of penetration of the color material on the recording medium. In other words, even if the same ink is used, by using different processing liquids, the degree of infiltration of the coloring material on the recording medium is controlled, so that gradation expression can be easily performed. That is, according to the present invention, by using a plurality of processing liquids, high-quality and excellent water resistance can be obtained, and gradation expression can be easily performed.

That is, the present invention imparts water resistance to a recorded image by reacting and aggregating a treatment liquid and an ink on a recording medium, and at the same time, differentiating at least one or more types of recording medium. By using at least two kinds of processing liquids having permeability, it is possible to control the degree of infiltration of the coloring material into the recording medium and express gradation.

Of course, there is no problem in the gradation expression of the recorded image when a general conventionally known gradation expression method is used in combination with the gradation expression method of the present invention. In other words, the gradation expression of the present invention controls the density of an image by varying the degree of infiltration of a coloring material into a recording medium.
As a result, the same expression as expressing gradation by the number of pixels per unit area conventionally used can be obtained. Further, it is obvious that a superior image can be naturally obtained by combining them.

Hereinafter, the present invention will be described in detail based on preferred embodiments. Of course, the present invention is not limited to the following preferred embodiments. In detail, the treatment liquid used in the present invention has a composition containing a cationic substance, a water-soluble organic solvent, water, a pH adjuster, a surfactant (excluding anionic type), a preservative, and the like. .

Specifically, the processing liquid used in the present invention is: 1. Improve the water resistance of a recorded image; 2. Improve the print quality of the recorded image. There is no limitation as long as it has a function of reducing the blur of a different color boundary between different colors of a recorded image.
When the kind of cationic substance is contained in the treatment liquid, the above-mentioned effect can be exerted.

The cationic substance is not particularly limited as long as it has a cationic group in the molecule. For example, cationic surfactants, cationic oligomers and polymers are preferred.

For the cationic surfactants, preferred specific compounds include compounds of salts of primary, secondary and tertiary amines, specifically laurylamine, cocoamine,
Hydrochlorides such as stearylamine and rosinamine; quaternary ammonium type compounds, specifically, cetyltrimethylammonium chloride, lauryltrimethylammonium chloride, lauryltributylammonium chloride, benzyltributylammonium chloride;
Benzalkonium chloride and the like; amphoteric surfactants that show cationicity at a certain pH range, specifically those obtained by adjusting the amphoteric surfactant of amino acid type, betaine type compound and the like to have an isoelectric point or less, but of course It is not limited to these. And among these compounds, the fourth
A quaternary ammonium type compound is preferred.

Next, specific monomer units of cationic oligomers and polymers include vinylamine, allylamine, vinylpyridine, vinylimidazole, N, N-dimethylaminoacrylamide, ethyleneimine, 2-oxazoline and the like. However, of course, it is not limited to these.

In addition to the above-mentioned homopolymer of a cationic monomer unit, a copolymer with a non-ionic monomer unit, a non-ionic oligomer, or a partially polymerized polymer may be used. It is possible. Among these compounds, oligomers and polymers containing allylamine as a unit are particularly preferable.

Furthermore, when a low molecular weight cationic surfactant is used in combination with polyallylamine, the bleeding of a different color boundary can be reduced at the time of color recording. .

The content of these cationic substances is in the range of 0.1 to 20% by weight, preferably 0.1 to 15% by weight in the processing solution.

The water-soluble organic solvent contained in the treatment liquid includes polyhydric alcohols such as glycerin, monohydric alcohols such as isopropanol, amides such as N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, and antone. Ketones; ethers such as tetrahydrofuran and dioxane; polyalkylene glycols such as polyethylene glycol; alkylene glycols such as ethylene glycol and propylene glycol; lower alkyl ethers of polyhydric alcohols such as triethylene glycol and monomethyl ether; Is mentioned. The content of these water-soluble organic solvents is in the range of 5 to 60% by weight, preferably 5 to 50% by weight in the treatment liquid.

As the water contained in the treatment liquid, ion-exchanged water is used. The content of these waters is 20 to
It is used in an amount of 80% by weight, preferably 40 to 80% by weight.

Next, the ink used in the present invention will be described. In the present invention, a water-soluble dye can be used as the coloring material of the color recording ink. A water-soluble dye having an anionic group as a solubilizing group is used.

The ink used in the present invention contains water, a water-soluble organic solvent, and other components such as a viscosity adjuster, a pH adjuster, a fungicide, a neutral or anionic interface, in addition to the water-soluble dye. Activators, antioxidants and the like are included as needed.

In the present invention, the colors of the inks for recording colors are black, cyan, magenta, and yellow, and examples of the coloring material include an anionic water-soluble dye.

The water-soluble dye having an anionic group used in the present invention includes a color index (COLOUH).
R INDEX), water-soluble acid dyes described in
There is no particular limitation as long as it is a direct dye or a reactive dye. Also,
There is no particular limitation on dyes not described in the color index as long as they have an anionic group, for example, a sulfone group. These dyes are used in the ink in the range of 1 to 10% by weight, preferably 1 to 5% by weight.

Specific dyes include C.I. I. Direct yellow 8, 11, 12, 27,
28, 33, 39, 44, 50, 58, 85, 86, 8
7, 88, 98, 100, 110 C.I. I. Direct Red 2, 4, 9, 11, 20,
23, 24, 31, 39, 46, 62, 75, 79, 8
0, 83, 89, 95, 197, 201, 218, 22
0, 224, 225, 226, 227, 228, 230 C.I. I. Direct Blue 1, 15, 22, 25, 4
1, 76, 77, 80, 86, 90, 98, 106, 1
08, 120, 158, 163, 168, 199, 22
6

C. I. Acid Yellow 1, 3, 7,
11, 17, 23, 25, 29, 36, 38, 40, 4
2, 44, 76, 98, 99 C.I. I. Acid Red 6, 8, 9, 13, 14, 1
8, 26, 27, 32, 35, 42, 51, 52, 8
0, 83, 87, 89, 92, 94, 106, 114,
115, 133, 134, 145, 158, 198, 2
49, 265, 289 C.I. I. Acid Blue 1, 7, 9, 15, 22, 2
3, 25, 29, 40, 43, 59, 62, 74, 7
8, 80, 90, 100, 102, 104, 117, 1
27, 138, 158, 161

C. I. Direct black 17, 1
9, 22, 31, 32, 51, 62, 71, 74, 11
2, 113, 154, 168 C.I. I. Acid Black 2, 48, 51, 52, 1
10, 115, 156 C.I. I. Reactive Black 1, 8, 12, 13 C.I. I. Food Black 1, 2 and the like. Of course, it is not limited more.

In addition to the above, as a coloring material of an ink for recording a color used in the present invention: Dyes having a carboxyl group as a solubilizing group This includes dyes that show solubility dependence on pH. 2. Oil-soluble dye Pigments and the like can also be used.

The ink containing these coloring materials has a property that, when it comes into contact with the ink containing the water-soluble anionic dye, it does not cause border bleeding due to precipitation at the boundary and incompatibility with each other. It is. In particular, 1. ~ 3. Many color materials have excellent water resistance.

Examples of the dye having a carboxyl group include the following, but of course, the present invention is not limited to dyes having these structures.

[0040]

Embedded image

[0041]

Embedded image

The oil-soluble dye is not particularly limited as long as it is described in the color index (COLOUR INDEX). Also, there is no particular limitation on a novel dye not described in the color index. Specifically, C.I. I. Solvent blue 33, 38, 42, 45,
53, 65, 67, 70, 104, 114, 115, 1
35 C.I. I. Solvent Red 25, 31, 86, 92,
97, 118, 132, 160, 186, 187, 21
9 C. I. Solvent yellow 1,49,62,74,
79, 82, 83, 89, 90, 120, 121, 15
1, 153, 154 and the like.

These dyes are used in the ink in an amount of 1 to 10% by weight, preferably 1 to 5% by weight.

When a pigment is used as a coloring material of the ink used in the present invention, the amount of the pigment is 1 to 20% by weight, preferably 2 to 20% by weight based on the total weight of the ink.
Used in the range of 12% by weight.

The pigment used in the present invention includes:
Specifically, carbon black is used as the black ink. The carbon black is, for example, a carbon black manufactured by a furnace method or a channel method, and has a primary particle diameter of 15 to 40 m.
μ, specific surface area by BET method is 50 to 300 m ² / g,
Those having properties such as a DBP oil absorption of 40 to 150 m1 / 100 g, a volatile content of 0.5 to 10%, and a pH value of 2 to 9 are preferably used. As a commercially available product having such characteristics, for example, 2300, no. 900, MC
F88, No. 33, no. 40, no. 45, no.
52, MA7, MA8, No. 2200B (manufactured by Mitsubishi Kasei), RAVEN 255 (manufactured by Columbia),
REGAL400R, REGAL 330R, REGAL
L660R, MOGUL L (made by Cabot)
Color Black FW1, COLOR Bla
ckFW18, Color Black S170, C
color Black Sl50, Printex 3
5, Printex U (made by Degussa), etc.
Any of them can be preferably used.

Examples of the pigment used in the yellow ink include C.I. I. Pigment Yellow
1, C.I. I. Pigment Yellow 2,
C. I. Pigment Yellow 3, C.I. I.
Pigment Yellow 13, C.I. I. Pigm
ent Yellow 16 and C.I. I. Pigment
Yellow 83 and the like,

Examples of the pigment used in the magenta ink include C.I. I. Pigment Red 5, C.I.
I. Pigment Red 7, C.I. I. Pigme
ntRed 12, C.I. I. Pigment Red
48 (Ca), C.I. I. Pigment Red 48
(Mn), C.I. I. Pigment Red 57 (C
a), C.I. I. Pigment Red 112, C.I.
I. Pigment Red 122 and the like,

As the pigment used for the cyan ink,
For example, C.I. I. Pigment Blue 1, C.I.
I. Pigment Blue 2, C.I. I. Pigm
ent Blue 3, C.I. I. Pigment Bl
ue 15: 3, C.I. I. Plgment Blue
16, C.I. I. Pigment Blue 22, C.I.
I. Vat Blue 4, C.I. I. Vat Blue
6 and the like, but are not limited thereto. In addition to the above, of course, pigments newly produced for the present invention can also be used.

When a pigment is used, any dispersing agent for incorporating the pigment into the ink can be used as long as it is a water-soluble resin. Those having a range of 30,000 are preferred, and those having a range of 3,000 to 15,000 are preferably used. Specific examples of such dispersants include styrene, styrene derivatives, vinyl naphthalene, vinyl naphthalene derivatives, aliphatic alcohol esters of α, β-ethylenically unsaturated carboxylic acids, acrylic acid, acrylic acid derivatives, and maleic acid. , Maleic acid derivatives, itaconic acid, itaconic acid derivatives, fumaric acid, fumaric acid derivatives, vinyl acetate, vinylpyrrolidone, acrylamide, derivatives thereof, and the like (at least one of which is at least one Block copolymers composed of (hydrophilic monomers), random copolymers, graft copolymers, and salts thereof. Alternatively, natural resins such as rosin, shellac and starch can also be preferably used. These resins are soluble in an aqueous solution in which a base is dissolved, and are alkali-soluble resins. The water-soluble resin used as a pigment dispersant is preferably contained in the range of 0.1 to 5% by weight based on the total weight of the ink.

In particular, in the case of an ink containing the above-described pigment, it is preferable that the entire ink is adjusted to be neutral or alkaline. Such a configuration is preferable because the solubility of a water-soluble resin used as a pigment dispersant can be improved, and an ink having more excellent long-term storage properties can be obtained. However, in this case, it may cause corrosion of various members used in the ink jet recording apparatus. Therefore, it is preferable to set the pH range to 7 to 10.

The pH adjusting agent used at this time includes:
Examples thereof include various organic amines such as diethanolamine and triethanolamine, inorganic alkali agents such as hydroxides of alkali metals such as sodium hydroxide, lithium hydroxide and potassium hydroxide, organic acids and mineral acids. The water-soluble resin as a pigment and a dispersant as described above is dispersed or dissolved in an aqueous liquid medium.

The aqueous liquid medium suitable for the pigment-containing ink used in the present invention is a mixed solvent of water and a water-soluble organic solvent. The water is not general water containing various ions, but water. It is preferable to use ion-exchanged water (deionized water).

Examples of the water-soluble organic solvent used by mixing with water include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol and tert-butyl alcohol. Alkyl alcohols having 1 to 4 carbon atoms; amides such as dimethylformamide and dimethylacetamide; ketones or keto alcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; polyalkylenes such as polyethylene glycol and polypropylene glycol Glycols; ethylene glycol, propylene glycol, butylene glycol, triethylene glycol,
1,2,6-hexanetriol, thiodiglycol,
Alkylene glycols having an alkylene group containing 2 to 6 carbon atoms, such as hexylene glycol and diethylene glycol; glycerin; ethylene glycol monomethyl (or ethyl) ether, diethylene glycol methyl (or ethyl) ether, triethylene glycol monomethyl (or ethyl) Lower alkyl ethers of polyhydric alcohols such as ethers; N-methyl-2-pyrrolidone;
2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone and the like. Among these many water-soluble organic solvents, polyhydric alcohols such as diethylene glycol and lower alkyl ethers of polyhydric alcohols such as triethylene glycol monomethyl (or ethyl) ether are preferable.

The content of the water-soluble organic solvent in the ink as described above is generally in the range of 3 to 50% by weight, preferably in the range of 3 to 40% by weight based on the total weight of the ink. The content of water used is in the range of 10 to 90% by weight, preferably 30 to 80% by weight of the total weight of the ink.

The ink containing the pigment used in the present invention may contain, in addition to the above-mentioned components, a surfactant, an antifoaming agent, and the like in order to obtain an ink having desired physical properties as required. Preservatives and the like can be appropriately added. Further, in addition to the above-mentioned pigment, a water-soluble dye as described above or the like can be appropriately added as a coloring material. Similarly to the above, when an ink containing a pigment is used, the surface tension of the ink is preferably larger than the surface tension of the liquid composition according to the present invention. It is preferable to adjust the surface tension of the ink in such a manner.

As a method of preparing an ink containing a pigment as described above, first, a pigment is added to an aqueous medium containing at least water and a water-soluble resin as a dispersant,
After stirring, dispersion is performed using a dispersion means described below, and if necessary, centrifugation is performed to obtain a desired dispersion liquid. Next, a sizing agent and appropriately selected additive components as described above are added to the dispersion, followed by stirring to obtain an ink used in the present invention.

When an alkali-soluble resin as described above is used as a dispersing agent, it is necessary to add a base to dissolve the resin. Organic amines such as ethanolamine, diethanolamine, triethanolamine, amine methylpropanol, and ammonia, and inorganic bases such as potassium hydroxide and sodium hydroxide are preferably used.

In the method of preparing an ink containing a pigment, it is effective to perform premixing for 30 minutes or more before stirring and dispersing the aqueous medium containing the pigment. That is, such a premixing operation is preferable because the wettability of the pigment surface can be improved and the adsorption of the dispersant on the pigment surface can be promoted.

The dispersing machine used in the above-mentioned pigment dispersion treatment may be any commonly used dispersing machine, and examples thereof include a ball mill, a roll mill and a sand mill. Among them, a high-speed type sand mill is preferably used. Examples of such a type include a super mill, a sand grinder, a bead mill,
Agitator mill, Glen mill, Dyno mill, Pearl mill, Kobol mill (all trade names) and the like.

When an ink containing a pigment is used in an ink-jet recording method, a pigment having an optimum particle size distribution is used due to a demand for clogging resistance and the like. As a method of obtaining a pigment,
Decreasing the size of the grinding media of the disperser, increasing the filling rate of the grinding media, increasing the processing time, slowing the discharge speed, classifying with a filter or centrifugal separator after grinding, etc. And other methods.

In the present invention, when an ink containing a pigment is used, in addition to the various components described above, the ink may contain an anionic compound such as an anionic surfactant or an anionic polymer. Is preferably added. In particular, when an anionic compound is not used as a dispersant, it is essential to add such an anionic substance. The addition amount at this time is 0.05 to
10% by weight, preferably 0.2 to 5% by weight.

Further, the amphoteric surfactant is converted to a p
It is also a preferred embodiment to adjust the content to H. Examples of the anionic surfactant used at this time include carboxylate type, sulfate type, sulfonate type, phosphate type and the like, and any commonly used one can be preferably used. . Examples of the anionic polymer include an alkali-soluble resin, specifically, sodium polyacrylate, or a polymer obtained by copolymerizing acrylic acid with a part of the polymer. Of course, it is not limited to these.

Next, the image forming method of the present invention will be described. In the present invention, an ink jet recording method in which a recording signal is applied to the ink of the recording head and droplets are ejected by the generated thermal energy is preferably used.

FIG. 1 is a perspective view showing an ink jet recording apparatus applicable to such an image forming method of the present invention. 1, 2, and 3 show examples of the configuration of a recording head which is a main part of the apparatus.

The head 13 includes a glass, ceramic or plastic plate having a groove 14 through which ink passes, and a heating head 15 having a heating resistor used for thermal recording (the head is shown in the figure, but is not limited to this. Is not obtained). The heating head 15 includes a protective film 16 made of silicon oxide or the like, and the aluminum electrode 1.
7-1 and 17-2, a heating resistor layer 18 made of nichrome or the like, a heat storage layer 19, and a substrate 20 having good heat dissipation such as alumina.

The ink 21 has a discharge orifice (fine hole) 2
The meniscus 23 is formed by a pressure (not shown).

When an electric signal is applied to the electrodes 17-1 and 17-2, the area of the heating head 15 indicated by n rapidly generates heat, and bubbles are generated in the ink 21 in contact with the area.
The meniscus 23 is protruded by the pressure, the ink 21 is ejected, becomes a recording droplet 24 from the orifice 22, and flies toward the recording material 25.

FIG. 3 is an external view of a multi-head in which a number of nozzles shown in FIG. 1 are arranged. The multi-head is manufactured by closely contacting a glass plate 27 having a multi-groove 26 and a heating head 28 similar to that described with reference to FIG. FIG.
FIG. 2 is a cross-sectional view of the head 13 along the ink flow path, and FIG. 2 is a cross-sectional view taken along line AB in FIG.

FIG. 4 is an explanatory view showing a head unit used in the present invention. FIG. 4 shows the structure of the processing solution (S ₁ )
A chip 301, a processing liquid (S ₂ ) chip 302, a black (Bk) ink chip 303, and an integrated yellow (Y), magenta (M), and cyan (C) ink chips 304, 305, and 306 are attached to a frame 300. The configuration is fixed to. The interval between the chips is 1/2 inch, and is fixed at equal intervals in the X direction which is the main operation direction. The number of nozzles for each chip is 160 for 301, 302, and 303, respectively, and 48 for 304, 305, and 306, respectively. 8 between 304 and 305 and between 305 and 306
There is a separation unit for each of the nozzles, and separates the respective inks.

The area where each processing liquid adheres to the recording medium is the same as the corresponding image forming area of each ink, and the printing duty is 100% for both the processing liquid and the ink.

Next, a method of forming an image using each of the yellow (Y), magenta (M), cyan (C), and black (BK) inks and the ink processing liquid using the head unit shown in FIG. Will be described.

Each recording head shown in FIG. 4 ejects ink of each color according to a recording signal. In addition, a processing liquid (a YMC processing liquid, BK for Y, M, and C inks in FIG. 4)
For the ink, the BK processing liquid is attached to an image area where at least the corresponding color ink adheres to the recording medium before or after the corresponding ink. Each recording head is moved by a carriage in the direction of X in the drawing, and the recording material is moved upward by a paper feed roller toward the paper surface.

The image forming method of the present invention can be applied to all devices using printing materials (recording media) such as paper, cloth, leather, nonwoven fabric, OHP paper, and the like. Specific examples of applicable equipment include office equipment such as printers, copiers, and facsimile machines, and industrial production equipment.

[0074]

The present invention will be described in more detail with reference to the following examples.
In the following description, “parts” and “%” mean “weight basis” unless otherwise specified.

First, the ink used in the examples will be described. Of course, the ink suitable for the present invention is not limited to the ink described below.

Black ink C.I. I. Food Black 2 4 parts Glycerin 10 parts Thiodiglycol 8 parts Acetylenol EH (manufactured by Kawaken Fine Chemical Co., Ltd.) 0.05 parts Water 77.95 parts After the above components are mixed and sufficiently stirred, the pH is adjusted to about 9 with sodium hydroxide. , A fluoropore filter having a pore size of 0.22 μm (trade name, manufactured by Sumitomo Electric Industries, Ltd.)
, To obtain a black dye ink Bk.

Cyan ink C.I. I. Direct Blue 199 4 parts Glycerin 10 parts Thiodiglycol 8 parts Acetylenol EH (manufactured by Kawaken Fine Chemical Co., Ltd.) 0.1 parts Water 77.9 parts After the above components are mixed and sufficiently stirred, the pH is adjusted to about 9 with sodium hydroxide. , A fluoropore filter having a pore size of 0.22 μm (trade name, manufactured by Sumitomo Electric Industries, Ltd.)
Under pressure to obtain a cyan dye ink C.

Magenta ink C.I. I. Acid Red 289 3 parts Glycerin 10 parts Thiodiglycol 8 parts Acetylenol EH (manufactured by Kawaken Fine Chemical Co., Ltd.) 0.1 parts Water 78.9 parts After the above components are mixed and sufficiently stirred, the pH is adjusted to about 9 with sodium hydroxide. , A fluoropore filter having a pore size of 0.22 μm (trade name, manufactured by Sumitomo Electric Industries, Ltd.)
Under pressure to obtain a magenta dye ink M.

Yellow ink C.I. I. Direct Yellow 142 3 parts Glycerin 10 parts Thiodiglycol 8 parts Acetylenol EH (manufactured by Kawaken Fine Chemical) 0.1 part Water 78.9 parts After mixing the above components, stirring thoroughly, and adjusting the pH to about sodium hydroxide. After adjusting to 9, a fluoropore filter having a pore size of 0.22 μm (trade name, manufactured by Sumitomo Electric Industries, Ltd.)
Under pressure to obtain a yellow dye ink Y.

Treatment liquid S1 Polyallylamine hydrochloride 4 parts Benzalkonium chloride (cation G50, manufactured by Sanyo Chemical Co., Ltd.) 1 part Diethylene glycol 15 parts Water 84 parts After mixing the above components and stirring thoroughly, the pore size is 0.22.
μm Fluoropore Filter (Sumitomo Electric Industries, Ltd .:
The solution was subjected to pressure filtration under the trade name (trade name) to obtain a treatment liquid S1 having a pH of 7.

Incidentally, regarding polyallylamine, the functional material Vol. 5, 29 (1986).

Treatment solution S2 Polyallylamine hydrochloride 3 parts Benzalkonium chloride (Cation G50, manufactured by Sanyo Chemical Co., Ltd.) 1 part Diethylene glycol 15 parts Water 84.5 parts After mixing the above components and stirring thoroughly, the pore size was 0.22.
μm Fluoropore Filter (Sumitomo Electric Industries, Ltd .:
The solution was subjected to pressure filtration under the trade name (trade name) to obtain a treatment liquid S2 having a pH of 7.

Treatment Solution S3 Polyallylamine hydrochloride 2.5 parts Benzalkonium chloride (Cation G50, manufactured by Sanyo Chemical Co., Ltd.) 1 part Diethylene glycol 15 parts Water 84.9 parts After the above components are mixed and sufficiently stirred, the pore size is reduced to 0. .22
μm Fluoropore Filter (Sumitomo Electric Industries, Ltd .:
The solution was subjected to pressure filtration under the trade name (trade name) to obtain a treatment liquid S3 having a pH of 7.

After mixing each of the treatment liquids S1, S2, and S3 with the Bk ink at a ratio of 1: 1, the absorption coefficient of the supernatant was measured. As a result, when S1 was set to 1, S2 and S3 were each 1.
3, 2.0.

Using each ink having the above-mentioned composition, ink-jet recording was carried out according to the combinations and recording methods shown in Table 1 below.

As a recording apparatus, an ink jet recording apparatus in which two ink jet heads (360 dpi) for generating droplets by applying thermal energy to the ink in the recording head and ejecting the ink are arranged in the main scanning direction is used. Recording on PPC paper, bond paper and recycled paper.

The recording was performed by the following method. Using the head unit shown in FIG. 4 and the combinations shown in Table 1,
Each processing liquid, Y ink, M ink, C ink, and BK ink were subjected to color inkjet recording on each sheet of a recording medium. The Y, M, and C inks and the processing liquids S1, S
The ejection amount of S2 and S3 is about 40 pl / dot, and the ejection amount of BK ink is about 80 pl / dot. The area where each processing liquid adheres to the recording medium during the image formation is the same as the image formation area of the ink, and the print duties are all 100% duty.

[0088]

[Table 1]

(Note) The extinction coefficient is a value obtained by measuring the absorption coefficient of the supernatant liquid obtained by mixing the treatment liquid at 25 ° C. and the ink at a weight ratio of 1: 1 and standing for 1 minute using a spectrophotometer.

The evaluation items are as follows. (1) Image density ◎: A density difference can be sufficiently visually confirmed for each processing liquid in all papers. ：: In some papers, the concentration difference between the treatment liquids could not be confirmed visually enough. Δ: The density difference can be sufficiently confirmed visually for each processing solution in some papers. ×: The density difference between the treatment liquids cannot be sufficiently confirmed visually for all the papers.

(2) Character Quality Alphanumeric characters were printed, and the print quality after natural drying in a room for 12 hours was evaluated. A: Almost no feathering in all treatment solutions. 〇: Feathering was slightly observed in some processing solutions, but there was no practical problem. Δ: Feathering was conspicuous in some of the processing liquids, and had a practical problem. ×: Feathering is conspicuous and has a practical problem.

(3) Water Resistance A solid image and alphanumeric characters of each color ink were printed, left for 1 hour, and immersed in tap water at a water temperature of 20 ° C. for 10 seconds. Then, it was taken out of the water and air-dried as it was, and the water resistance was visually evaluated.

Evaluation criteria: A: All of the processing liquids did not cause the recording agent to flow into the margins, and almost no background dirt was observed. In addition, almost no bleeding of alphanumeric characters has occurred. ：: Almost no run-off of the recording agent into the margins and background fouling are observed with all the processing liquids. In addition, although some bleeding of alphanumeric characters occurs, this is a level that is not a problem in practical use. D: Almost no run-off of the recording agent into the margin and background contamination were observed. In addition, bleeding of alphanumeric characters occurs, which poses a practical problem.

Table 2 shows the evaluation results.

[0095]

[Table 2]

[0096]

As described above, according to the image forming method of the present invention, high-speed printing and gradation expression can be performed on a recording medium, color bleeding can be reduced, print quality, water resistance, etc. This has the effect of obtaining an excellent image.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a head section of an ink jet recording apparatus.

FIG. 2 is a cross-sectional view of a head section of the inkjet recording apparatus.

FIG. 3 is an external perspective view of a head unit of the inkjet recording apparatus.

FIG. 4 is an explanatory view showing a head unit used in the present invention.

DESCRIPTION OF SYMBOLS 13 Head 14 Ink groove 15, 28 Heating head 16 Protective film 17-1, 17-2 Aluminum electrode 18 Heating resistor layer 19 Heat storage layer 20 Substrate 21 Ink 22 Discharge orifice (micro hole) 23 Meniscus 24 Recording Small droplet 25 Recording material 26 Multi groove 27 Glass plate

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Mikishi Ogasawara 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Eriko Ono 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (72) Inventor Yutaka Kurabayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (10)

[Claims] 1. A method comprising the steps of: (A) applying an ink treatment liquid onto a recording medium by an ink jet method; and (B) recording an ink for recording a color on the recording medium by an ink jet recording method. And the step (A) is performed using at least two kinds of processing liquids in which the ratio of the absorption coefficient of the supernatant liquid when the processing liquid and the ink are mixed at a weight ratio of 1: 1 is 1: 1.3 or more. Performing an image forming method. 2. The image forming method according to claim 1, wherein said at least two or more types of processing solutions contain at least one type of cationic substance at different concentrations. 3. The image forming method according to claim 2, wherein the cationic substance is a cationic surfactant. 4. The image forming method according to claim 2, wherein said cationic substance is polyallylamine. 5. The image forming method according to claim 2, wherein the cationic substance comprises a cationic surfactant and polyallylamine. 6. The image forming method according to claim 1, wherein the step (A) is performed prior to the step (B). 7. The image forming method according to claim 1, wherein the step (A) is performed after the step (B). 8. The image forming method according to claim 1, wherein the step (A) is performed after the step (B) is performed, and then the step (B) is further performed. 9. The image forming method according to claim 1, wherein recording of one pixel of the ink for recording the color is performed by a plurality of nozzle rows. 10. The image forming method according to claim 1, wherein the treatment liquid is attached to a recording medium by a plurality of nozzle rows.