JPH0525415A - Ink for ink-jet recording and recording method using the same - Google Patents

Abstract

PURPOSE:To record a high-density, gradient, full-color image or character on a recording medium. CONSTITUTION:The objective ink comprises a medium comprising water or a water-soluble organic solvent and microcapsules dispersed therein. The contents of the microcapsules consist of a recording composition comprising an organic colorant dissolved or dispersed in water, a water-soluble organic solvent, or a heat-fusible substance. The recording method using this ink comprises jetting the ink onto a recording medium and then pressing the recording medium with or without heating, thereby to break the microcapsules to record an image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording ink composed of microcapsules containing a colored dye and a recording method therefor. In particular, the present invention relates to an inkjet recording ink having a high density of images and characters recorded on a recording medium and excellent in gradation of a full-color image, and a recording method thereof.

[0002]

2. Description of the Related Art The ink jet recording system is one in which minute droplets of ink in which a colored dye is dissolved are ejected by various operating principles and adhered to a recording medium such as paper to record an image, a character or the like. However, there are features such as high speed, low noise, easy multicolorization, great flexibility in recording patterns, and no need for development and fixing. Various figures and color images including Kanji As a recording device such as the above, it is rapidly spreading for various uses. But,
The full-color image formed by the multicolor ink jet recording system is still insufficient in gradation when compared with the multicolor printing by the photoengraving system or the sublimation type thermal transfer system.

This is because in the ink jet recording system, there is a limit to the apparatus even if the dot density is increased, and it is 300 to 40.
This is because 0 dpi is common. For this reason, various proposals have been made from the recording medium side for the purpose of providing high resolution, high chromaticity, and high gradation.

For example, JP-A-55-5830 discloses an ink jet recording paper having an ink-absorptive coating layer on the surface of a support, and JP-A-55-51583 discloses a pigment as a pigment in a coating layer. Example using colloidal silica powder, JP-A-55
No. 11829 shows an example of a coated paper using a two-layer structure having different ink absorption rates, and in JP-A No. 57-107878, a coating layer containing synthetic silica and colloidal silica is provided on the surface of a support. Examples, JP-A-57-107879 and U
In SP 4,440,827, two or more coating layers containing synthetic silica and colloidal silica are provided on the surface of a support. In JP-A-58-65692, no-size base paper is coated with a pigment and an aqueous polymer. An example of a coated paper obtained by coating a dispersion, agglomeration, and a dry treatment with a water-soluble adhesive, and JP-A-58-72495 discloses a silica pigment having an average particle diameter of 0.05 μm or less and a water-soluble adhesive. Examples of coated paper coated with a polymer binder, JP-A-58-110287 and USP 4,46
In No. 0,637, one or more coating layers were provided on the surface of the support, and one peak of the pore distribution curve of the uppermost layer was 0.2.
.mu.m to 10 .mu.m, and the peak of the pore distribution curve of all the ink receiving layers is at least 0.2 .mu.
Two examples having a size of 05 μm or less are disclosed.

With respect to these reference recording media, efforts have been made to obtain high image quality by controlling the dot diameter, chromaticity, ink absorbability, etc. by devising the material surface for coating. With regard to gradation, there is a large factor derived from the printing density of the recording apparatus, and satisfactory gradation has not yet been obtained.

[0006]

SUMMARY OF THE INVENTION As described above, the conventional ink-jet recording ink and its recording method are intended to solve the characteristics of print density and gradation which have room for improvement.

[0007]

DISCLOSURE OF THE INVENTION As a result of intensive studies, the present inventors provide an ink for ink jet recording excellent in print density and gradation and a recording method therefor.

That is, the ink jet recording ink provided by the present invention is an ink jet recording ink containing microcapsules in a medium composed of water or a water-soluble organic solvent, and the inclusion of the microcapsules is
It comprises a recording composition in which a colored dye is dissolved or dispersed in water, a water-soluble organic solvent, or a heat-fusible substance.

In the ink jet recording method provided by the present invention, the inclusion of microcapsules is a recording composition in which a colored dye is dissolved or dispersed in water or a water-soluble organic solvent or a heat-fusible substance. In addition, after ink jet recording on a recording medium using an ink jet recording ink containing the microcapsule in a medium composed of water or a water-soluble organic solvent, pressure treatment is applied to destroy the microcapsule. In addition, heat treatment is performed.

Further, in the ink-jet recording ink and the recording method thereof of the present invention, the microcapsules each independently contain a colored dye consisting of yellow, magenta, cyan and black.

In the ink jet recording method of the present invention, the recording medium comprises at least one ink receiving layer coated on the surface of a support.

In the present invention, as the ink for ink jet recording, the ink composed of microcapsules containing a colored dye and having an average particle diameter of several microns is used to print using a known recording medium, and then press It is possible to obtain an image with high density and excellent gradation by treating and destroying the microcapsules, or by heat-treating the microcapsules to release the inclusions in the microcapsules onto the recording medium. I found out.

As for the hue of the colored dye encapsulated in the microcapsules, it is possible to obtain a full-color image by using yellow, magenta, cyan, and black as in the conventional case. In order to effectively adsorb the colored dye in the microcapsule or the recording composition in which the colored dye is dissolved or dispersed in the surface layer of the recording medium, the recording medium is more preferable than the recording medium on which the ink receiving layer is not coated. Also, the recording medium having at least one ink receiving layer coated thereon is preferable.

The reason why high density and gradation can be obtained in the present invention will be described in comparison with a conventional ink jet recording system.

In the conventional recording method, for example, when red is produced by yellow and magenta, several tens are recorded on the recording medium.
A yellow ink drop of micron is printed, and a magenta ink drop of several tens of microns is printed on the yellow ink drop, so that a phenomenon occurs in which the absorptivity and the dot diameter of the yellow ink and the magenta ink are different. That is, the magenta ink is deeper and more absorbed than the yellow ink so as to surround the yellow ink on the recording medium.

In comparison with this, with the ink jet recording ink of the present invention, yellow and magenta inks are printed as ink drops of several tens of microns, and the dispersion medium (water or water-soluble) of the microcapsules in each ink is printed. Since the organic solvent) is absorbed and then pressure-treated, the yellow dye and the magenta dye, which are microcapsule inclusions, are first mixed or absorbed into the recording medium while being mixed. The feature is that there is no difference between the colored pigments. Therefore,
In the present invention, the mixed color dye is uniformly absorbed in the vicinity of the surface layer of the recording medium, so that high density and gradation can be obtained.

In the case where the microcapsule inclusions are not released only by the pressure treatment, for example, when the microcapsule inclusions are a composition composed of a colored dye and a heat-fusible substance, the inclusions are treated by heating after the pressure treatment. Is preferably released. A method of simultaneously performing pressure-heat treatment such as passing through a nip between a heating roll and a metal roll, or a method of heating while laminating with a heat laminator after pressurization may be adopted.

The colored pigments used in the present invention include direct dyes, acid dyes, basic dyes, reactive dyes, water-soluble or oil-soluble dyes such as food dyes, and colored pigments composed of finely pulverized organic pigments. Examples include dyes. As illustrated above, conventionally known colored dyes can be used without problems. The water-soluble dye is dissolved in water or a water-soluble organic solvent, and the oil-soluble dye is dissolved or dispersed in the water-soluble organic solvent to be provided as a microcapsule inclusion. or,
The organic pigment may be provided as a microcapsule-encapsulated recording composition in which finely pulverized one is dispersed in water or a water-soluble organic solvent.

In the ink jet recording ink of the present invention, the mixing ratio (% by weight) of the microcapsules dispersed in a medium composed of water or a water-soluble organic solvent is 60% by weight or less based on the total weight of the ink. , Preferably 50% by weight or less. In this case, depending on the viscosity and physical properties of the ink, the mixing ratio may be appropriately changed to a value of about 50 cps or less. Here, if the mixing ratio of the microcapsules exceeds 60% by weight, the nozzle holes of the recording device may be clogged, which is not preferable.

The colored pigment contained in the microcapsules is
The mixing ratio with respect to the total weight of the inclusions may be appropriately changed between water or a water-soluble organic solvent in which this is dissolved or dispersed.
It is 0.5 to 30% by weight, preferably 1 to 15% by weight. Here, if the mixing ratio of the color dye exceeds 30% by weight, it is difficult to dissolve the color dye or the dispersion becomes poor, which is not desirable.

The method of microencapsulation may be a known method, for example, a complex coacervation method, an interfacial polymerization method, or an in-situ method.
u) A polymerization method, an orifice method, a spray drying method and the like can be mentioned.

The microcapsule dispersion as an ink for ink jet recording is appropriately ink jet depending on the combination of the microcapsule inclusions with water or a water-soluble organic solvent which is a dispersion medium for the colored dye, or a heat fusible substance. A recording device can be used.

The water-soluble dyes used in the present invention are exemplified below, but the invention is not limited thereto.

Direct dyes include C.I. I. Direct Black: 2, 4, 9, 1
1, 14, 17, 19, 22, 27, 32, 36, 3
8, 41, 48, 49, 51, 56, 62, 71, 7
4, 75, 77, 78, 80, 105, 106, 10
7, 108, 112, 113, 117, 132, 14
6, 154, 194 C.I. I. Direct Yellow: 1, 2, 4,
8, 11, 12, 24, 26, 27, 28, 33, 3
4, 39, 41, 42, 44, 48, 50, 51, 5
8, 72, 85, 86, 87, 88, 98, 100, 1
10, C.I. I. Direct Orange: 6, 8, 10,
26, 29, 39, 41, 49, 51, 102, C.I. I. Direct Red: 1, 2, 4, 8, 9,
11, 13, 17, 20, 23, 24, 28, 31,
33, 37, 39, 44, 46, 47, 48, 51,
59, 62, 63, 73, 75, 77, 80, 81, 8
3, 84, 85, 90, 94, 99, 101, 10
8, 110, 145, 189, 197, 220, 22
4,225,226,227,230, C.I. I. Direct Violet: 1, 7, 9, 1
2, 35, 48, 51, 90, 94, C.I. I. Direct Blue: 1, 2, 6, 8, 1
5, 22, 25, 34, 69, 70, 71, 72, 7
5, 76, 78, 80, 81, 82, 83, 86, 9
0, 98, 106, 108, 110, 120, 123,
158, 163, 165, 192, 193, 194,
195, 196, 199, 200, 201, 202,
203, 207, 218, 236, 237, 239, 2
46,258,

Acid dyes include C.I. I. Acid Black: 1, 2, 7, 16, 1
7, 24, 26, 28, 31, 41, 48, 52, 5
8, 60, 63, 94, 107, 109, 112, 11
8, 119, 121, 122, 131, 155, 15
6, C.I. I. Acid Yellow: 1, 3, 4, 7, 1
1, 12, 13, 14, 17, 18, 19, 23, 2
5, 29, 34, 36, 38, 40, 41, 42, 4
4, 49, 53, 55, 59, 61, 71, 72, 7
6, 78, 99, 111, 114, 116, 122,
135, 161, 172, C.I. I. Acid Orange: 7, 8, 10, 3
3, 56, 64, C.I. I. Acid Red: 1, 4, 6, 8, 13, 1
4, 15, 18, 19, 21, 26, 27, 30, 3
2, 34, 35, 37, 40, 42, 51, 52, 5
4, 57, 80, 82, 83, 85, 87, 88, 8
9, 92, 94, 97, 106, 108, 110, 11
5,119,129,131,133,134,13
5, 154, 155, 172, 176, 180, 18
4, 186, 187, 249, 254, 256, 31
7, 318, C.I. I. Acid Violet: 7, 11, 15, 3
4, 35, 41, 43, 49, 75, C.I. I. Acid Blue: 1, 7, 9, 22, 2
3, 25, 27, 29, 40, 41, 43, 45, 4
9, 51, 53, 55, 56, 59, 62, 78, 8
0, 81, 83, 90, 92, 93, 102, 104,
111, 113, 117, 120, 124, 126, 1
45, 167, 171, 175, 183, 229, 23
4, 236, C.I. I. Basic Black: 2, 8, C.I. I. Basic Yellow: 1, 2, 11, 1
2, 14, 21, 32, 36, C.I. I. Basic Orange: 2, 15, 21,
22, C.I. I. Basic Red: 1, 2, 9, 12, 1
3, 37, C.I. I. Basic Violet: 1, 3, 7, 1
0, 14, C.I. I. Basic Blue: 1, 3, 5, 7, 9,
24, 25, 26, 28, 29,

Examples of the reactive dye include C.I. I. Reactive Black: 1, 3, 5,
6, 8, 12, 14, C.I. I. Reactive Yellow: 1, 2,
3, 13, 14, 15, 17, C.I. I. Reactive Orange: 2, 5,
7, 16, 20, 24, C.I. I. Reactive Red: 6, 7, 11, 1
2, 15, 17, 21, 23, 24, 35, 36, 4
2, 63, 66, C.I. I. Reactive Violet: 2, 4,
5, 8, 9, C.I. I. Reactive Blue: 2, 5, 7, 1
2, 13, 14, 15, 17, 18, 19, 20, 2
1, 25, 27, 28, 37, 38, 40, 41,

Further, as a food colorant, C.I. I. Food Black: 2, C.I. I. Food Yellow: 3, 4, 5, C.I. I. Food Red: 2, 3, 7, 9, 14, 5
2, 87, 92, 94, 102, 104, 105, 10
6, C.I. I. Food Violet: 2, C.I. I. Food Blue: 1, 2, and the like.

The oil-soluble dyes used in the present invention are exemplified below, but the invention is not limited thereto.

Examples of oil-soluble dyes include azo dyes, azo metal complex salt dyes, anthraquinone dyes and phthalocyanine dyes. More specifically, it is as follows. Azo dye: Solvent Yellow 2 (C.I. 11020,
Hereafter, parentheses are C. I. No. ), Solvent Orange 1 (1920), Solvent Red 24 (26
105), Solvent Brown 3 (11360), Azo metal complex salt dye: Solvent Yellow 19 (13900)
A), Solvent Orange 5 (1845A), Solvent Red 8 (12715), Solvent Brown 37,
Solvent Black 123 (12195), Anthraquinone Dye: Solvent Violet 13 (6
0725), Solvent Blue 11 (61525), Solvent Green 3 (61565), Phthalocyanine dye: Solvent Blue 25 (7435)
0),

The organic pigments used in the present invention are exemplified below, but the invention is not limited thereto.

As the organic pigment, azo pigments (monoazo,
Bisazo, condensed azo pigments), dyed lake pigments (acid dye lakes, basic dye lakes, mordant dye lake pigments), nitro pigments, nitroso pigments, phthalocyanine pigments, high-grade pigments (vat dye pigments, metal complex salt pigments, perylene pigments) , Isoindolinone pigments, quinacdrine pigments) and the like. More specifically, it is as follows.

Azo pigment: Hansa Yellow G (1168)
0), Hansa Yellow R (12710), Pyrazolone Red B (21120), Permanent Red R (1208)
5), Rake Red C (15585), Brilliant Carmine 6B (15850), Permanent Carmine FB
(12490) [above monoazo pigment], benzidine yellow G (21090), benzidine yellow GR (2110)
0), Permanent Yellow NCR (20040) [above bisazo pigment], Chromophthal yellow, Chromophtal red [above condensed azo pigment] Dyeing lake pigment: quinoline yellow lake (4700
5), Eosin Lake (45380), Alkaline Blue Lake (42750A, 42770A) [above Acid Dye Lake], Rhodamine Lake B (45170), Methyl Violet Lake (42535), Pictoria Blue Lake (44045), Malachite Green Lake ( Four
2000) [or more basic dye lake], alizarin lake (580000) [or more mordant dye lake pigment] Nitro pigment: Naphthol yellow S (10316), Nitroso pigment: Pigment Green B (10006),
Naphthol Green B (10020) Phthalocyanine Pigment: Metal-Free Phthalocyanine Blue (7
4100), phthalocyanine blue (74160), phthalocyanine green (74260), high-grade pigment: anthrapyrimidine yellow (68420),
Indus Brilliant Orange GK (59305), Induslen Blue RS (69800), Thioindigo Red B (73300) [Vat dyestuff pigments], Nickel Azo Yellow (12775) [Metal Complex Salt Pigment], Perylene Red (71140), Perilence Scared (71
137) [Perylene pigment], isoindolinone yellow [isoindolinone pigment], quinacridone red Y (4
6500), quinacridone magenta (73915), and carbon black (7726) as a black pigment.
There is 5).

As a material for dissolving or dispersing the colored dye used in the present invention, water or a water-soluble organic solvent which is also a medium for dispersing the microcapsules is used in common.
The water-soluble organic solvent will be exemplified below, but the invention is not limited thereto.

As the water-soluble organic solvent, methyl alcohol, ethyl alcohol, n-propyl alcohol, n-
Butyl alcohol, sec-butyl alcohol, ter
C1-C4 alkyl alcohols such as t-butyl alcohol and isopropyl alcohol; amides such as dimethylformamide and dimethylacetamide; acetone,
Ketones or ketone alcohols such as diacetone alcohol; ethers such as tetrahydrofuran and dioxane;
Polyalkylene glycols such as polyethylene glycol and polypropylene glycol; ethylene glycol,
Alkylene glycols having 2 to 6 alkylene groups such as propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol, diethylene glycol; glycerin, ethylene glycol, methyl ether, Examples thereof include lower alkyl ethers of polyhydric alcohols such as diethylene glycol methyl (or ethyl) ether, triethylene glycol and monomethyl ether.

Among many of these water-soluble organic solvents,
Preferred are polyhydric alcohols such as diethylene glycol and lower alkyl ethers of polyhydric alcohols such as triethylene glycol monomethyl ether and triethylene glycol monoethyl ether.

As described above, the dispersion medium composed of the colored pigment and the heat-fusible substance has been described. The heat-fusible substance includes plant waxes such as rice wax, candelilla wax and carnauba wax. , Lanolin, beeswax, animal wax such as Cerax wax,
Mineral wax such as montan wax, paraffin wax, microcrystalline wax, oxide wax,
Synthetic waxes such as chlorinated paraffin wax, ricinoleic acid amide, palmitic acid amide, oleic acid amide, 12-hydroxystearic acid, distearyl ketone, and ethylenebisstearic acid amide, higher alcohols such as palmityl alcohol, stearyl alcohol, and cetyl alcohol. , Low molecular weight polyethylene, low molecular weight polystyrene, polyester resin, polyamide resin, polyacrylic resin, polyvinyl acetate, ethylene-vinyl acetate copolymer, and other synthetic resins.

In the ink jet recording ink of the present invention, a wetting agent such as glycols, glycol ethers, amides and pyrrolidones, a binder, and a surfactant are used in a medium in which microcapsules containing colored dyes are dispersed. ,
Addition of additives such as an oxygen absorber, a physical property modifier, a charge modifier, an antifungal agent and a chelating agent is not limited in any way.

The recording medium of the present invention has at least one ink receiving layer provided on the surface of a support.

As the support, high-quality paper, coated paper, synthetic paper, plastic film or the like can be used as appropriate and is not particularly limited.

The ink receiving layer provided on the surface of the support is made of a generally used material containing a filler, a pigment and an adhesive as main components.

The fillers and pigments that can be used in the present invention include:
For example, light calcium carbonate, heavy calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium oxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminum silicate, diatomaceous earth, calcium silicate,
There are white inorganic pigments such as magnesium silicate, synthetic amorphous silica, aluminum hydroxide, alumina and lithopone, and organic pigments such as styrene plastic pigments, acrylic plastic pigments, microcapsules and urea resin pigments.

Examples of the adhesive used in the present invention include polyvinyl alcohol, oxidized starch, etherified starch, cellulose derivatives such as carboxymethyl cellulose and hydroxyethyl cellulose, casein, gelatin,
Soybean protein, silanol-modified polyvinyl alcohol, maleic anhydride resin, ordinary styrene-butadiene copolymer, conjugated methacrylate copolymer latex such as methylmethacrylate-butadiene copolymer, polymer of acrylic acid ester and methacrylic acid ester Alternatively, acrylic polymer latex such as copolymer, vinyl polymer latex such as ethylene vinyl acetate copolymer, or functional group-modified polymer latex with functional group-containing monomer such as carboxyl group of these various polymers Water-based adhesive such as thermosetting synthetic resin such as melamine resin and urea resin, and synthetic resin adhesive such as polymethylmethacrylate, polyurethane resin, unsaturated polyester resin, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral and alkyd resin Agents used alone or in combination It is.

Other additives include pigment dispersants, thickeners, fluidity improvers, defoamers, foam suppressors, mold release agents, foaming agents, penetrants, colored dyes, colored pigments, fluorescent whitening agents. An agent, an ultraviolet absorber, an antioxidant, an antiseptic agent, an antifungal agent, a water resistance agent, a wet paper strength enhancer, a dry paper strength enhancer and the like can be appropriately added.

In the present invention, an ink receiving layer is provided on the surface of a support, and a sheet obtained by coating the surface of the support with an ink receiving layer can be used as it is as a recording medium of the present invention. It is also possible to impart surface smoothness through a roll nip under heating and / or pressure with a gloss calendar or the like. In this case, excessive processing by the super calender lowers the ink absorbability due to the voids between the particles formed at the corners, so that the processing degree may be limited.

[0045]

EXAMPLES The present invention will be specifically described below with reference to examples.

Example 1 1. Production of Microcapsules Polyurea wall material microcapsules containing a colored pigment were produced as follows. To 90 parts of ion-exchanged water, C.I. I. Basic Black-2
Was dissolved in 10 parts, and hexamethylenediamine 1.
Five parts were dissolved to prepare a microcapsule inclusion (core substance). On the other hand, as a hydrophobic substance that emulsifies the core substance,
Dissolve 7.5 parts of polyisocyanate, which is an addition product of trimethylolpropane and tolylene diisocyanate, in 300 parts of butyl acetate, and further add 1 part of sorbitan tristearate as an emulsifier and stir until uniform. I was there. A prepared core substance was gradually added to the prepared hydrophobic substance with stirring to emulsify it. When the average particle size of the emulsified particles reached 10 μm, the system temperature was gradually raised to 35 ° C. and the reaction was carried out for 3 hours. After the reaction, it was confirmed by an optical microscope that microcapsules having a polyurea wall film having an average particle diameter of 10 μm, which was almost the same as emulsified particles, were formed. Then, the microcapsules dispersed in butyl acetate are added to a mixed solution of 320 parts of water and 80 parts of ethylene glycol, and butyl acetate is removed under reduced pressure to obtain about 25% microcapsule aqueous dispersion. Obtained. The microcapsule water-soluble dispersion itself can be used as the inkjet recording ink of the present invention.

2. Production of recording medium for ink jet recording Neutral paper having a basis weight of 70 g / m 2 was used as a base paper, and 80 parts of synthetic amorphous silica (Fineseal X-37B, manufactured by Tokuyama Soda Co., Ltd.) and light calcium carbonate (Callite) were used on one side. KT, manufactured by Shiraishi Calcium Co., Ltd., 20 parts, polyvinyl alcohol (PVA117, manufactured by Kuraray Co., Ltd.), 40 parts, cationic resin (SUMIREZ RESIN 1001, manufactured by Sumitomo Chemical Co., Ltd.), 30 parts by weight, was applied with an air knife coater. Coating was performed so that the solid content was 8 g / m @ 2, and the surface was supercalendered to obtain a recording medium.

3. Printing test The ink for inkjet recording obtained in the above 1 was used to print on the recording medium of the above 2 and evaluated. As the printing device, an inkjet printer manufactured by Sharp Corporation (IO-720) was used, and the recording medium of the printed image recorded by the printing device was passed through a super calender to destroy the microcapsules in the image area to complete the printing. The print image obtained here had a perfect print dot diameter and a high print density.

Example 2 1. Production of microcapsules C.I. I. Instead of the acidic dye of Basic Black-2, yellow, magenta, and cyan dyes can be used as C.I. I. Basic Yellow-2, C.I. I. Basic Red-9, C.I. I. Bas
ic Blue-25 was used to obtain a microcapsule aqueous dispersion for each hue, that is, an ink jet recording ink of the present invention.

2. Printing test Using the recording medium and the printing device used in Example 1, a full-color image input by a scanner was printed on the recording medium in the order of yellow, magenta, and cyan ink, and this was passed through a super calendar, and the micro-image of the image part was printed. Printing was completed by destroying the capsule. With respect to the printed image, it was possible to obtain an image having high printing density, color and gradation by uniformly mixing the respective inks.

Comparative Example 1 Using the ink jet recording ink prepared in Example 2, printing was performed on a recording medium in the same manner as in Example 2. Here, without applying pressure treatment by the super calendar of Example 2,
I left it as it was. As a result, the print density was low, and the chromaticity and gradation were poor as compared with Example 2.

Example 3 1. Production of Microcapsules Melamine-formaldehyde wall material microcapsules containing a colored pigment were produced as follows. While melting 90 parts of paraffin wax having a melting point of 70 ° C., 1 part of Solvent Black-123 was added as an azo metal complex salt dye.
0 part was added and dispersed until uniform, to prepare a microcapsule inclusion (core substance). This was added to 120 parts of a 5% aqueous solution having a pH of 4.0 in which a styrene-maleic anhydride copolymer was dissolved together with a small amount of sodium hydroxide.
It was dispersed and emulsified at a temperature of 0 ° C. Here, the emulsified particles had an average particle diameter of 12 μm. Separately, a melamine-formaldehyde initial shrinkage product is prepared as a film material. The initial melamine-formaldehyde shrinkage product is melamine 10 parts, 37
% Aqueous formaldehyde solution (25 parts) and water (65 parts) were adjusted to pH 9 with sodium hydroxide and heated to 60 ° C. to dissolve the solution to a transparent state. Melamine-formaldehyde initial shrinkage was added to the previously emulsified emulsion, and the liquid temperature was maintained at 60 ° C. with stirring to perform microencapsulation. The average particle size of the microcapsules was 12 μm, which was almost the same as the average particle size of the emulsified particles. The solid content concentration of the manufactured microcapsule dispersion was about 40%. 2. Preparation of Inkjet Recording Ink To 320 parts of the microcapsule dispersion obtained in 1 above, 80 parts of diethylene glycol was added to prepare an inkjet recording ink. 3. Printing Evaluation The recording medium and the printing device used in Example 1 printed a monochrome image input by a scanner on the recording medium, and passed this through a super calendar to destroy the microcapsules in the image area, and subsequently to 80 ° C. Printing was completed by passing through the set heat roll. As for the printed image, it was possible to obtain an image with high printing density and gradation by permeation of the microcapsule inclusions into the ink receiving layer.

Comparative Example 2 The ink for ink jet recording prepared in Example 3 was used to print on a recording medium in the same manner as in Example 3. Here, the pressure treatment by the super calendar of Example 3 and the heat treatment by the hot roll were not performed, and they were left as they were. As a result, the print density was lower than that in Example 3 and the gradation was poor.

[0054]

The present invention relates to an ink jet recording ink containing microcapsules in a medium composed of water or a water-soluble organic solvent, and a recording method therefor. In recording using the ink, high printing density and It is possible to obtain a printed image with excellent gradation of a full-color image.

Claims (5)

[Claims] 1. An ink jet recording ink containing microcapsules in a medium composed of water or a water-soluble organic solvent, wherein the inclusions of the microcapsules are water or a water-soluble organic solvent or a heat-fusible substance. An ink for inkjet recording, comprising a recording composition in which a colored dye is dissolved or dispersed. 2. The ink for ink jet recording according to claim 1, wherein the microcapsule is a microcapsule that individually contains colored dyes of yellow, magenta, cyan, and black. 3. A medium comprising microcapsules containing water or a water-soluble organic solvent, or a recording composition in which a colored dye is dissolved or dispersed in a heat-fusible substance, and comprising water or a water-soluble organic solvent. An inkjet characterized by performing inkjet recording on a recording medium using an inkjet recording ink containing the microcapsule therein, and then subjecting the microcapsule to a pressure treatment to destroy the microcapsule or heat treatment in addition to this. Recording method. 4. The ink jet recording method according to claim 3, wherein the microcapsule is a microcapsule that individually contains colored dyes of yellow, magenta, cyan, and black. 5. A recording medium having at least one surface on a support surface.
The ink jet recording method according to claim 3 or 4, wherein at least two ink receiving layers are provided by coating.