JPH06200200A - Ink composition for ink jet recording - Google Patents

Abstract

PURPOSE:To provide an ink jet composition giving high quality images free from the cissing and flow of the ink composition on good mold-releasable transfer media having low surface tensions irrespective of the patterns of the images. CONSTITUTION:In the ink composition containing at least water, a coloring agent, a thermoplastic resin, a saccharide and a surfactant and used for transfer type ink jet recording methods, the surfactant contains at least a surfactant having fluorine atoms in the molecule and a surfactant not containing a fluorine atom.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer type ink jet printer for obtaining an ink image on a recording medium by forming ink images on the transfer medium by ejecting ink droplets from the recording head. It relates to an ink composition.

2. Description of the Related Art As a conventional ink for ink jet recording of a type in which a recording image is written by ejecting ink droplets onto a recording medium, an example of the composition of an aqueous recording ink containing water, a coloring material and a water-soluble resin. Are disclosed in JP-A-2-276874, JP-A-2-255875, and the like, which aim to improve ejection stability from nozzles, fixability on a recording medium, and storage stability of ink. I am trying.
Also, Japanese Patent Publication No. 62-1426 and Japanese Patent Laid-Open No. 4-1846.
Japanese Patent Laid-Open No. 2 (1993) describes an ink composition example composed of water, a pigment and a water-insoluble synthetic resin emulsion for the purpose of fixing the ink image on a recording medium, preventing ink bleeding, and flow. Further, as examples of inks for transfer type printers, JP-A-62-92849 and US Pat.
Japanese Patent No. 38156 describes an ink composition example comprising water, a dye and a polyhydric alcohol. In the conventional example of this transfer type recording method, ink droplets are once ejected onto a transfer medium,
Here, most of the water in the ink droplets is evaporated and the concentrated ink is transferred onto a recording medium such as paper, and high print quality can be obtained without being affected by the difference in the recording medium. In addition, it made it possible to improve the dryness of the ink image.

However, the ink composition used in the conventional transfer type printer or the ink composition for ink jet recording of the type in which the recording image is written by directly ejecting the ink onto the conventional recording medium is transferred. When used in a type inkjet printer, there were the following problems. That is, when ink droplets are ejected onto a transfer medium having a good releasability to form an ink image, it is impossible to form a high-quality image free from ink repelling and flow regardless of the printing pattern. As the surface material of the transfer medium, in order to transfer the ink image formed on the transfer medium onto the recording medium so that no transfer residue occurs, a material having a good releasability of the ink image and a small surface energy is used. ing. For this reason, the ink mainly composed of water was repelled, and it was not possible to maintain and fix the shape and position of the ink image initially formed on the transfer medium. Especially in the case of a solid pattern in which the amount of ink per unit area is large, the fluidity of the ink is not lost because the drying speed is slow,
Repelling and flow easily occur. The present invention solves this problem, and an object thereof is to repel ink droplets on a transfer medium having a good releasability and form a high-quality image without flow or the like regardless of the printing pattern, which is recorded. It is an object of the present invention to provide a new ink composition for inkjet recording, which can obtain a high-quality image on a recording medium by transferring it onto the medium.

The ink composition for ink jet recording of the present invention is a transfer type ink jet recording ink composition containing at least water, a coloring material, a thermoplastic resin, a saccharide, and a surfactant. It is characterized in that the surfactant comprises at least a surfactant having fluorine in the molecule and a surfactant having no fluorine in the molecule.

In the ink composition for ink jet recording of the present invention, since the surfactant contained in the ink comprises at least a surfactant having fluorine in the molecule and a surfactant having no fluorine in the molecule, Since the appropriate wettability of the ink on the transfer medium due to the surface tension is obtained, it is possible to form a high-quality ink image on the transfer medium that does not repel or flow regardless of the printing pattern.

EXAMPLES First, examples of the constitution of the ink jet recording ink of the present invention will be described in detail. Conventionally, as a solvent for ink, it has a low viscosity, excellent safety,
Water is mainly used because it is easy to handle, the cost is low, and there is no odor. As the ink material, pure water or ultrapure water that has undergone a purification process such as ion exchange or distillation is desirable. As coloring agents, pigments, water-soluble dyes,
A disperse dye or a water-insoluble dye (when kneaded and added with a thermoplastic resin) is used, which has a good affinity with water as a main solvent, or one which can be uniformly dispersed by using a dispersant or the like in combination. If you can use it. Examples of pigments that can be used in the ink of the present invention include organic pigments and inorganic pigments. For black, carbon blacks such as furnace black, lamp black, acetylene black, and channel black (C.I. Pigment Black 7) or copper, iron (C.I. Pigment Black 1)
1), metals such as titanium oxide, aniline black (C.
I. Pigment Black 1) and other organic pigments. For color, C.I. I. Pigment Yellow 1 (Fast Yellow G), 3, 1
2 (this as yellow AAA), 13, 14, 17, 24, 3
4, 35, 37, 42 (yellow iron oxide), 53, 55, 8
1, 83 (This As Yellow HR), 95, 97, 98, 10
0, 101, 104, 108, 109, 110, 11
7, 120, 138, 153, C.I. I. Pigment Orange 5, 13, 16, 17, 36, 43, 51, C.I.
I. Pigment Red 1, 2, 3, 5, 17, 22 (Brilliant First Scarlet), 23, 31, 38, 48: 2 (Permanentlet 2B (Ba)), 48: 2 (Permanentlet 2B (Ca)), 4
8: 3 (Permanentlet 2B (Sr)), 48: 4 (Permanentlet 2B)
(Mn)), 49: 1, 52: 2, 53: 1, 57: 1 (Brilliant Carmine 6B), 60: 1, 63: 1, 63: 2, 64: 1, 81
(Rotamine 6G rake), 83, 88, 101 (Bengara),
104, 105, 106, 108 (Cadmium Let), 11
2, 114, 122 (quinacridone magenta), 123, 146, 149, 166,
168, 170, 172, 177, 178, 179, 185, 190, 193, 209, 219, CI Pigmen Violet 1 (Rotamine lake), 3, 5: 1, 16, 19 (Quinacridonelet), 23, 38, C. I. Pigment Blue 1, 2, 15 (Phthalocyanine Blue R), 15: 1, 15: 2, 1
5: 3 (phthalocyanine blue G), 15: 4, 15: 6 (phthalocyanine blue E), 16, 17: 127 (dark blue), 28 (covert blue), 29 (marine blue), 56, 60, 63, C.I. I. Pigment Green 1, 4, 7, 8, 10, 17, 18, 3
6, etc., and other processed pigments such as graft carbon whose surface is treated with a resin can be used. The amount added is
0.5 to 30% by weight is preferable, but 1.0 to 1 is more preferable.
2% by weight is more preferred. A pigment having a particle size of 25 μm or less is used, and a pigment having particles of 1 μm or less is more preferably used. In order to uniformly disperse these colorants, the dispersant may be added to the pigment in an amount of 0.5 if necessary.
˜200 wt%, more preferably 1 to 50 wt%, particularly preferably 10 to 30 wt%, and it is desirable to carry out dispersion treatment with a ball mill or the like. Typical examples of the dispersant for dispersing the pigment used in the ink of the present invention include acrylic resins, and specific examples of such acrylic resins include, for example, styrene-acrylic acid copolymer, acrylic acid-acrylic. Acid alkyl ester copolymer, styrene-acrylic acid-acrylic acid alkyl ester copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic acid alkyl ester copolymer, styrene-α-methylstyrene-acrylic acid Examples thereof include copolymers, styrene-α-methylstyrene-acrylic acid-acrylic acid alkyl ester copolymers and salts thereof. When the dispersant is dissolved in water, 2-aminoisobutanol, triethanolamine, morpholine, aqueous ammonia, propylene glycol, isopropanol, etc. may be used as an auxiliary agent. Examples of the water-soluble dye used in the ink of the present invention include direct dyes, acid dyes, basic dyes and food dyes. I. Direct Black 9, 17, 19, 22, 3
2, 51, 56, 62, 69, 77, 80, 91, 9
4, 97, 108, 112, 113, 114, 117,
118, 121, 122, 125, 132, 146, 1
54, 166, 168, 173, 199, C.I. I. Direct Red 2, 4, 9, 23, 26, 31, 39, 6
2, 63, 72, 75, 76, 79, 80, 81, 8
3, 84, 89, 92, 95, 111, 173, 18
4, 207, 211, 212, 214, 218, 22
1, 223, 224, 225, 226, 227, 23
2, 233, 240, 241, 242, 243, 24
7, C.I. I. Direct Violet 7, 9, 47, 4
8, 51, 66, 90, 93, 94, 95, 98, 10
0, 101, C.I. I. Direct Yellow 8, 9, 1
1, 12, 27, 28, 29, 33, 35, 39, 4
1, 44, 50, 53, 58, 59, 68, 86, 8
7, 93, 95, 96, 98, 100, 106, 10
8, 109, 110, 130, 132, 142, 14
4, 161, 163, C.I. I. Direct Blue 1, 1
0, 15, 22, 25, 55, 67, 68, 71, 7
6, 77, 78, 80, 84, 86, 87, 90, 9
8, 106, 108, 109, 151, 156, 15
8, 159, 160, 168, 189, 192, 19
3, 194, 199, 200, 201, 202, 20
3, 207, 211, 213, 214, 218, 22
5,229,236,237,244,248,24
9, 251, 252, 264, 270, 280, 28
8, 289, 291, C.I. I. Acid black 7,2
4, 29, 48, 52: 1, 172, C.I. I. Acid Red 35, 42, 52, 57, 62, 80, 82, 1
11, 114, 118, 119, 127, 128, 13
1, 143, 151, 154, 158, 249, 25
4, 257, 261, 263, 266, 289, 29
9, 301, 305, 336, 337, 361, 39
6, 397, C.I. I. Acid Violet 5, 34,
43, 47, 48, 90, 103, 126, C.I. I. Acid Yellow 17, 19, 23, 25, 39, 40,
42, 44, 49, 50, 61, 64, 76, 79, 1
10, 127, 135, 143, 151, 159, 16
9, 174, 190, 195, 196, 197, 19
9, 218, 219, 222, 227, C.I. I. Acid Blue 9, 25, 40, 41, 62, 72, 76, 7
8, 80, 82, 92, 106, 112, 113, 12
0, 127: 1, 129, 138, 143, 175, 1
81, 205, 207, 220, 221, 230, 23
2, 247, 258, 260, 264, 271, 27
7, 278, 279, 280, 288, 290, 32
6, C.I. I. Reactive Black 4, 5, 8, 14,
21, 23, 26, 31, 32, 34, C.I. I. Reactive Red 3, 13, 17, 19, 21, 22, 2
3, 24, 29, 35, 37, 40, 41, 43, 4
5, 49, 55, C.I. I. Reactive Violet 1, 3, 4, 5, 6, 7, 8, 9, 16, 17, 22,
23, 24, 26, 27, 33, 34, C.I. I. Reactive Yellow 2, 3, 13, 14, 15, 17, 1
8, 23, 24, 25, 26, 27, 29, 35, 3
7, 41, 42, C.I. I. Reactive blue 2, 3,
5, 8, 10, 13, 14, 15, 17, 18, 19,
21, 25, 26, 27, 28, 29, 38, C.I. I.
Basic Black 8, C.I. I. Basic red 1
2, 13, 14, 15, 18, 22, 23, 24, 2
5, 27, 29, 35, 36, 38, 39, 45, 4
6, C.I. I. Basic Violet 1, 2, 3, 7,
10, 15, 16, 20, 21, 25, 27, 28, 3
5, 37, 39, 40, 48, C.I. I. Basic Yellow 1, 2, 4, 11, 13, 14, 15, 19, 2
1, 23, 24, 25, 28, 29, 32, 36, 3
9, 40, C.I. I. Basic Blue 1, 3, 5, 7,
9, 22, 26, 41, 45, 46, 47, 54, 5
7, 60, 62, 65, 66, 69, 71, C.I. I. Food black and the like are used, but not limited to these. Examples of the disperse dyes and water-insoluble dyes that are used by being dispersed in the ink of the present invention or mixed or dissolved in a resin include C.I. I. Solvent Black 3, 5, 22, C.I. I. Solvent Yellow 19, 44, 98, 104, 105, 1
12, 113, 114 C.I. I. Solvent Red 8, 24, 71, 109, 1
52, 155, 176, 177, 179 C.I. I. Solvent Blue 2, 11, 25, 78, 9
4, 95, C.I. I. Solvent Green 26, C.I. I.
Solvent Orange 5, 40, 45, 72, 63, 6
8, 78 C.I. I. Solvent Violet 13, 31, 32, 3
3, C.I. I. Disperse Yellow 3, 5, 56, 60,
64, 160 C.I. I. Day Super Red 4, 5, 60, 72, 7
3, 91, C.I. I. Desperce Blue 3, 7, 56,
60, 79, 198 C.I. I. Disperse oranges 13, 30 and the like are used, but not limited to these. The addition amount of these dyes is determined depending on the type of dye, the type of solvent component, the properties required for the ink, etc., but is generally 0.2 to 10% by weight, preferably the total weight of the ink. Is preferably in the range of 0.5 to 5% by weight. As the thermoplastic resin used in the ink of the present invention, those having a heat softening temperature, a heat melting temperature or a film forming temperature of 50 ° C to 150 ° C are used.
Desirably, a temperature of 60 ° C to 100 ° C is used, and one
Alternatively, two or more kinds can be mixed and used. The amount added is such that the ratio of thermoplastic resin: colorant is 1: 0.1.
A range of 0.2: 1 is good. However, as the addition amount is increased, the ink viscosity is also increased. Therefore, it is preferable to suppress the addition amount to about 30% by weight with respect to the entire ink.
Examples of thermoplastic resins include polyacrylic acid, polymethacrylic acid, polyethylacrylic acid, styrene-butadiene copolymer, butadiene copolymer, acrylonitrile-butadiene copolymer, chloroprene copolymer, crosslinked acrylic resin, crosslinked Styrene resin, fluororesin, vinylidene fluoride, benzoguanamine resin, phenol resin, polyolefin resin, cellulose, styrene-acrylic copolymer, styrene-methacrylic copolymer, polystyrene, styrene-acrylamide copolymer, n-isobutyl acrylate, Acrylonitrile, vinyl acetate, acrylamide, silicone resin, polyvinyl acetal,
Polyamide, rosin resin, polyethylene, polycarbonate, vinylidene chloride resin, polyvinyl alcohol,
Cellulosic resins, epoxy resins, vinyl acetate resins, ethylene-vinyl acetate copolymers, vinyl acetate-acrylic copolymers, vinyl chloride resins, polyurethanes, rosin esters, microgels, microemulsions, etc., but are not limited to these. Not something. The following are examples of low molecular weight thermoplastic resins that can be used in the ink of the present invention. For example, polyethylene wax, montan wax, alcohol wax, synthetic oxide wax, α-olefin-maleic anhydride copolymer, animal and vegetable wax such as carnauba wax, lanolin, paraffin wax, microcrystalline wax, etc.,
Any material having excellent fastness when transferred onto a recording medium can be used. The above resins are in the form of colored resin particles integrated with a coloring material dispersed in the ink, in the form of resin alone dispersed in the ink as fine particles, and in the form of emulsion particles stabilized and dispersed in water. Etc. are preferably added. Further, although these resins are dried under a normal temperature environment, it is desirable to form a powder or a brittle solid without forming a film, in order to obtain robustness of the printed matter transferred onto the recording medium, It is desirable to form a strong and water resistant film when heated above the softening temperature, melting temperature or film forming temperature. The saccharide used in the ink of the present invention imparts tackiness of the ink image formed on the transfer medium and improves the transferability to the recording medium, and examples thereof include glucose, diose, maltitol, and triose.
Tetrose, pentose, hexose, heptose,
Octose, nonose, sucrose (sucrose),
Monosaccharides such as inositol, xylose, maltotriose, galactose, α-cyclodextrin, disaccharides, trisaccharides, tetrasaccharides, polysaccharides and their derivatives, sugar alcohols, reduced derivatives such as deoxy sugars, aldonic acid, uronic acid, etc. Examples include oxidized derivatives, dehydrated derivatives such as glycoethene, and sugars such as amino sugars and thio sugars. Polysaccharides refers to sugars in a broad sense, and includes substances widely existing in nature such as alginic acid, dextrin, and cellulose.
These sugars are preferably used in the ink of the present invention in a content ratio of sugar to thermoplastic resin of from 1: 4 to 4: 1. If the content of sugar is too low, it forms on the transfer medium. The adhesiveness of the formed ink image is small and causes uneven transfer and density unevenness on a recording medium. If the amount is too large, water resistance and scratch resistance of the printed matter decrease. Examples of the surfactant containing fluorine in the molecule used in the ink of the present invention include perfluoroalkyl polyoxyethylene ethanol, fluorinated alkyl ester, perfluoroalkyl alkoxylate, alkyl perfluoroalkyl sulfonic acid ammonium salt, and perfluoro. Alkylsulfonic acid potassium salt, perfluoroalkylcarboxylic acid, perfluoroalkylcarboxylic acid potassium salt, perfluoroalkylcal quaternary ammonium iodide, perfluoroacrylate, disodium N-perfluorooctanesulfonylglutamate, 3- (fluoroalkyl) Oxy) -1-alkyl sulfonate sodium, 3- (ω-
Fluoroalkanoyl-N-ethylamino) -1-propanesulfonic acid sodium salt, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- (2-
Hydroxyethyl) perfluorooctane sulfonamide, perfluoroalkyl-N-ethylsulfonylglycine salt, bis (N-perfluorooctylsulfonyl-N-ethylaminoethyl) phosphate, monoperfluoroalkylethyl phosphate ester, etc. It is not limited to these. As the surfactant containing no fluorine in the molecule used in the ink of the present invention, one or more kinds of anionic, cationic, amphoteric and nonionic surfactants can be added. For example, as the anionic surfactant, higher fatty acid salt, higher alkyl dicarboxylic acid salt, higher alcohol sulfate ester salt, higher alkyl sulfonate, alkyl benzene sulfonate, alkyl naphthalene sulfonate, naphthalene sulfonic acid salt (N
a, K, Li, Ca) formalin polycondensate, condensate of higher fatty acid and amino acid, dialkylsulfosuccinic acid ester salt, alkylsulfosuccinate, naphthenate, etc., alkyl ether carboxylate, acylated peptide, α-
Olefin sulfonate, N-acylmethyl taurine,
Examples thereof include alkyl ether sulfates, secondary higher alcohol ethoxy sulfates, polyoxyethylene alkylphenyl ether sulfates, monoglycerates, alkyl ether phosphate ester salts, and alkyl phosphate ester salts, but are not limited thereto. Cationic surfactants include, but are not limited to, aliphatic amine salts, quaternary ammonium salts, sulfonium salts, phosphonium salts and the like. Amphoteric surfactants include, but are not limited to, carboxybetaine type, aminocarboxylic acid salts, lecithin and the like. Nonionic surfactants include silicone-based, acrylic acid copolymers, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene secondary alcohol ethers, polyoxyethylene sterol ethers, polyoxyethylene lanolin derivatives, alkylphenols. Ethylene oxide derivative of formalin condensate, polyoxyethylene polyoxypropylene block polymer, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene compound fatty acid ester type, polyethylene oxide condensation type polyethylene glycol fatty acid ester, fatty acid monoglyceride, polyglycerin fatty acid ester , Sorbitan fatty acid ester, propylene glycol fatty acid ester, sucrose fatty acid ester Fatty acid alkanolamides, polyoxyethylene fatty acid amides, polyoxyethylene alkyl amines alkylamine oxides but are not limited thereto. The addition ratio of the above-mentioned fluorine-containing surfactant and non-fluorine-containing surfactant is preferably in the range of 0.1: 10 to 2: 1 in order to obtain appropriate wettability to the transfer medium, and further 0.1 : 1 to 1: 1 is desirable. Further, the total amount of the surfactant containing both is required to be 0.1 to 10 wt%, preferably 0.5 to 8 wt%. In addition, if necessary, pH adjusting agents such as potassium dihydrogen phosphate and disodium hydrogen phosphate, benzoic acid, dichlorophen, hexachlorophene, sorbic acid, p-hydroxybenzoic acid for the purpose of antifungal, antiseptic and rust prevention. Acid ester, ethylenediaminetetraacetic acid (EDTA), sodium dehydroacetate, 1,
2-bezothiazolin-3-one, 3,4-isothiazolin-3-one and the like can be included. Further, urea, thiourea, ethylene urea and the like can be added for the purpose of preventing nozzle drying. Further, a hydrophilic high-boiling point low-volatile solvent is added to the ink of the present invention in order to impart the effects of nozzle clogging resistance, moisture retention and dispersion stability. The hydrophilic high boiling point low volatility solvent used in the present invention includes glycerin, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, hexylene glycol, polyethylene glycol, polypropylene glycol, etc. Polyhydric alcohols are used, or their monoethers, diethers, and esters, such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether. Butyl ether etc. are used,
Others N-methyl-2-pyrrolidone, 1.3-dimethylimidazolidinone, monoethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, diethanolamine, N-n-butyldiethanolamine, triisopropanolamine, triethanol A water-soluble organic solvent such as a nitrogen-containing organic solvent such as an amine can be added within a range in which the flow of printing does not cause bleeding.
Further, with respect to water which is the main solvent, highly volatile monohydric alcohols such as ethanol, propanol, isopropanol, butanol, etc. as well as hexanol, heptanol, octanol, etc. are comparatively used for the purpose of improving drying properties and fixing properties. Low volatility alcohols can also be added in small amounts. The ink was manufactured by the following procedure, but the invention is not limited to this. Disperse an aqueous dispersion consisting of a colorant and a dispersant in a ball mill, and confirm by microscopic observation that the pigment particles are in a monodispersed state.Then, thermoplastic resin, saccharides, further surfactants, hydrophilic high A solvent with a low boiling point and low volatility are added, and the mixture is further stirred for 30 minutes and completely mixed. After adding additives such as preservatives and confirming complete dissolution, the dispersion was filtered through a membrane filter having a pore size of 10 μm to remove dust and coarse particles to obtain a recording ink. Finally, another filtration operation is effective in preventing the inclusion of impurities. Table 1 shows the composition of the ink composition of the present invention made of the above materials prepared by the above-described manufacturing method.

[Table 1] All the physical properties of the above ink examples are adjusted within the following ranges. The ink viscosity is 50 m in order to ensure stable ejection from the head and stable ink supply to the head.
Pa · sec or less is desirable, and more preferably 25 mPa · sec or less. The contact angle between the ink and the transfer medium is preferably 60 degrees or less in order to prevent the ink from repelling and flowing on the transfer medium and to form a high quality ink image. The surface tension of the ink is preferably 45 dyne / cm or less, more preferably 35 dyne / cm or less in order to ensure wettability with the transfer medium. The softening temperature, melting temperature or film forming temperature of the thermoplastic resin contained in the ink is preferably 60 ° C. to 120 ° C. so that the amount of heat at the time of heat fixing to the recording medium does not become excessive. The composition of the ink comparative example composition of the present invention is shown in Table 1. The method for producing each ink comparative example composition is shown below. Ink Comparative Example 1 An ink composition obtained by removing the surfactant from the composition of Example 1 was used.
An ink was prepared in the same manner as in Example 1. Ink Comparative Example 2 An ink composition containing only the fluorine-containing surfactant from the composition of Example 1 was prepared in the same manner as in Example 1 to obtain an ink. Ink Comparative Example 3 An ink composition containing no fluorine-containing surfactant from the composition of Example 1 was prepared in the same manner as in Example 1 to obtain an ink. Next, using each of the above inks, a printing test was conducted in a transfer type inkjet recording device described below. Figure 1
FIG. 1 is a perspective view showing a characteristic configuration of a transfer type inkjet printer of the present invention. FIG. 2 is a sectional view. An inkjet recording head 2, a backup roller 3 that is a transfer unit, and a cleaner 8 that removes deposits on the transfer drum as necessary are sequentially arranged around the transfer drum 1 that is a transfer medium from the upstream side in the rotation direction. There is. Further, inside the transfer drum 1, a heating means 7 is arranged between the recording head 2 and the backup roller 3, and further a second heating means 9 for heating the ink image transferred onto the recording paper 6 which is a recording medium. Are arranged on the moving path of the recording paper 6. The recording head 2 is an inkjet recording head of a type using a piezoelectric element, and has a plurality of nozzles in the axial direction of the transfer drum 1. An ink container 21 is connected to the recording head 2 and ink is supplied as necessary. The transfer drum 1 is formed by laminating an elastic layer 12 made of silicone rubber around a metal tube 11. A rubber material is suitable for the elastic layer 12, and among them, a good release material that easily peels an ink image and a material having a low surface energy are preferable, and silicone rubber, fluororesin, fluorosilicone rubber, or the like, or a modified product thereof. Is preferred. The backup roller 3 is a metal roller made of aluminum, and is configured to be able to press and release the transfer drum 1 by a transfer pressure applying device (not shown). During pressing, the recording paper 6 is rotated in the direction of arrow B in the figure at the same speed as the peripheral speed of the transfer drum 1. The transfer load was about 0.6 kgf / cm. The cleaner 8 is made of felt and is in contact with the transfer drum 1 with a predetermined pressure by an unillustrated contact mechanism. The heating means 7 is composed of a rod-shaped halogen lamp 15 and a reflector 16 having an elliptical surface as an inner surface, and the halogen lamp 15 is arranged at the first focal point of the reflector 16. The second heating means 9 includes a heat roll 4 and a pressure roll 30 that incorporate heating means such as a ceramic heater.
The recording paper 6 is guided by a guide plate (not shown) so as to pass through the nip portion formed by the heat roll 4 and the pressure roll 30. Next, the operation will be described. First, the ink image writing process will be described.
FIG. 3 is a diagram showing how an ink image is written. In the ink image writing process, the backup roller 3
Are controlled to be pressed against the surface of the transfer drum 1. The recording head 2 used in this embodiment is a line-shaped recording head having nozzles over the entire printing area L, and one rotation of the transfer drum 1 writes an ink image for one page. Ink droplets 5 are selectively ejected from the nozzles of the recording head 2 according to a recording signal to form a desired ink image 50.
At this time, since the surfactant contained in the ink provides appropriate wettability of the ink to the transfer drum, it is possible to form a high-quality ink image without repellency or flow.
Next, the ink image 50 (ink droplet 5) formed on the transfer drum 1 by the recording head 2 is heated by the heating means 7. The heating means 7 is controlled by a temperature detector (not shown) so as to be within a predetermined temperature range. The ink image on the transfer drum 1 is heated to increase the solid content concentration and form a sticky film. This is because sugar is contained in the ink composition. Next, the recording paper 6 is passed through the contact portion between the transfer drum 1 and the backup roller 3, and the ink image 50 on the transfer drum 1 is transferred to the recording paper 6 by the applied pressure.
Transfer to. At this time, since the ink image has uniform adhesiveness, it is not necessary to set the transfer pressure in the maximum concentrated state. Therefore, a high-quality image can be obtained on the recording paper 6 with a low pressure. Here, the low pressure means 1 kg weight / cm or less in order to downsize the apparatus, reduce the cost of components such as the transfer drum 1 and the backup roller 3, and further improve the durability of the elastic layer on the surface of the transfer drum. The weight is preferably 0.6 kgf / cm or less. The ink image pressure-transferred onto the recording paper 6 is the second heating means 9
Is heated to the softening temperature or film forming temperature of the thermoplastic resin contained in the ink or higher. In this embodiment, the softening temperature, the melting temperature or the film forming temperature of the thermoplastic resin contained in the ink is 65 to 80 ° C, and the heating temperature of the second heating means 9 is set to 150 ° C. The ink image 50 is
It is heated by the second heating means 9 and fused to the fibers of the recording paper 6, and at the same time, the pressure is applied by the pressure roller 30, so that the ink adheres along the irregularities of the fibers and the robustness is excellent. An ink image can be obtained on the recording paper 6. When the transfer drum 1 finishes transferring the ink image onto the recording paper 6, the transfer drum 1 moves to a portion in contact with the cleaner 8 as it rotates, and the residual ink on the transfer drum 1 is removed. The results of printing tests of the ink composition of the present invention and the ink composition of the comparative example using the above-mentioned transfer type inkjet recording device are shown below. The evaluation conditions are as follows. Printing pattern Solid 1 dot continuous line, transfer drum surface material Silicone resin Fluoro rubber Fluorosilicone resin Nitrile rubber (resin with high surface energy) The evaluation of printing test uses ink images of various printing patterns and various surface materials. Was formed on the transfer medium, and the image quality of the obtained ink image was judged according to the following criteria. Judgment Criteria ○: There is no image deformation such as repellency and flow △: Partial repellency and image deletion occur ×: Repulsion overall, image deletion occurs and characters cannot be read The above evaluation conditions and Ink composition 1 to
Table 2 shows the results of an investigation conducted using a transfer type ink jet recording apparatus by using 3, the ink comparative examples 1 and 2.

[Table 2] As shown in the table above, when the ink composition of the present invention was used, a high-quality ink image free from repelling and flow was formed on any transfer medium regardless of the print pattern. On the other hand, in the case of using the ink comparative example, the ink was repelled at the solid portion of the transfer medium having a low surface energy, the flow occurred, the image quality was disturbed, and uniform image quality could not be obtained. The above results show that the ink composition of the present invention contains a surfactant containing fluorine in the molecule and a surfactant not containing fluorine in the molecule, and thus has excellent surface releasability and low surface energy. This is obtained by the novel effect that a high quality ink image can be formed on the transfer drum regardless of the print pattern.

As described above, the ink composition for ink-jet recording of the present invention contains, in addition to water, a coloring agent, a thermoplastic resin and a saccharide, a surfactant containing at least fluorine in the molecule and fluorine in the molecule. By containing a surfactant that does not contain, it is possible to form a high-quality ink image that is repelled on a transfer medium with good releasability and does not flow, regardless of the printing pattern, and transfer it to the transfer medium. There is an effect that a high quality ink image can be obtained on the recording medium.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of a transfer type inkjet recording apparatus used for evaluation of an ink composition example of an example of the present invention.

FIG. 2 is a cross-sectional view showing a configuration of a transfer type inkjet recording device used for evaluation of an ink composition example of an example of the present invention.

[Explanation of symbols]

 1: Transfer drum (transfer medium) 2: Recording head 3: Backup roller 5: Ink image 6: Recording paper (recording medium) 7: Heating means 9: Second heating means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Issei Kawabata 138-1, Kokubunji, Kokubunji, Gokokuno-cho, Himeji City, Hyogo Prefecture

Claims (1)

[Claims] 1. At least water, a coloring material, a thermoplastic resin,
A transfer type ink jet recording ink composition containing a saccharide and a surfactant, characterized in that the surfactant comprises at least a surfactant having fluorine in the molecule and a surfactant having no fluorine in the molecule. An ink composition for inkjet recording.