JP2005350576A - Liquid composition, ink jet recording method, ink set for ink jet recording, recording unit, ink cartridge, ink jet recording apparatus and ink jet ink - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid composition which can give good printing quality images and can further achieve the elongation of an ink jet recording head life, in an ink jet recording method for adhering the liquid composition to a colored ink to form records on a medium to be recorded. <P>SOLUTION: This liquid composition for ink jet recording, which is used together with a colored ink and is brought into contact with the colored ink to react, is characterized by comprising (a) a polyvalent metal salt, (b) at least one compound selected from ≥4C reducing sugars, and (c) a liquid medium. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid composition, inkjet ink, inkjet recording ink set, inkjet recording method, recording unit, ink cartridge, and inkjet recording apparatus. Specifically, a liquid composition, ink jet ink, and ink jet recording ink that have good print quality, reduce color bleeding that occurs in the formation of a color image, and can extend the life of an ink jet recording head using thermal energy. The present invention relates to a set, an ink jet recording method using any of these, a recording unit, an ink cartridge, and an ink jet recording apparatus.

  The ink jet recording method is easy for downsizing the apparatus, low running cost, colorization, and the like, and is advantageous for forming a color image. However, there are some problems in the demand for higher image quality. For example, when two different types of ink are applied to a recording medium adjacent to each other, the inks mix with each other at the boundary portion, and a phenomenon (bleeding) in which the quality of the color image is deteriorated (bleeding) occurs. There is. Since the color mixture (bleed) at the boundary between the black ink and the color ink has a great influence on the degradation of the image quality, various solutions have been developed.

  For example, as described in Patent Documents 1 to 3, a first liquid containing a precipitating agent and a second liquid containing a coloring material (coloring material) that can generate a precipitate with the precipitating agent are used in combination. Thus, a technique for controlling color bleed is disclosed. A polyvalent metal salt is disclosed as the precipitant, and a dye having at least one carboxyl group is disclosed as a colorant that can be precipitated by the polyvalent metal salt. Further, the first liquid may contain a colorant, and in this case, the first liquid can also be used as ink.

JP-A-5-202328 US Pat. No. 5,198,023 JP-A-6-106841

  However, according to the study by the present inventors, when a solution containing a polyvalent metal salt as described in Patent Document 1 is repeatedly discharged by a bubble jet (registered trademark) system in order to prevent the above-described bleeding. It was discovered that kogation derived from this polyvalent metal salt may be formed on the heater in contact with the solution containing the polyvalent metal salt. As a result, there are cases in which the amount of droplets to be ejected and the velocity of the ejected droplets are reduced compared to the initial stage, which affects the image quality. Furthermore, it has also been discovered that there may be a problem that the heater is disconnected and the discharge of the polyvalent metal salt solution is disabled. This is because when an ink or a liquid composition containing a polyvalent metal salt is overheated by a heater, anion ions constituting the polyvalent metal salt are volatilized or broken. This is considered to be because the cation ion (polyvalent metal ion) concentration near the heater increases and the alkalinity becomes strong, so that the outermost surface protective film made of a metal such as tantalum and / or a metal oxide is dissolved. .

  Therefore, the present inventors have conducted extensive studies on a liquid composition or ink that has an effect of preventing bleeding and suppresses disconnection and burning of the heater and can extend the life of the head, resulting in the present invention. .

  Accordingly, an object of the present invention is to provide an image of good print quality in an ink jet recording method in which a liquid composition and a colored ink are adhered to perform recording on a recording medium, and further to extend the life of the ink jet recording head. It is providing the liquid composition which can achieve this.

  Another object of the present invention is to provide an ink set capable of providing an image with good print quality and achieving a long life of the ink jet recording head in an ink jet ink set having black ink and color ink. There is.

  Furthermore, another object of the present invention is to provide an ink set for ink jet recording, an ink jet recording method, a recording unit and an ink cartridge, and an ink jet recording apparatus which can provide an image with good print quality and further achieve a long life of the ink jet recording head. Is to provide.

  The above object is achieved by the present invention described below.

  That is, the liquid composition according to the present invention is a liquid composition for ink jet recording that is used together with a colored ink and reacts when contacted with the colored ink, and includes (a) a polyvalent metal salt and (b) a carbon number. It contains a substance selected from four or more reducing sugars and (c) a liquid medium.

The inkjet recording method according to the present invention includes:
(I) A step of applying energy to the liquid composition and discharging the liquid composition toward a recording medium to apply the liquid composition onto the recording medium;
(Ii) A coloring ink containing a coloring material and a liquid medium and reacting with the liquid composition by contact with the liquid composition is applied with energy and discharged toward the recording medium, and the colored ink is covered. And applying the steps (i) and (ii) so as to form a contact state between the liquid composition and the colored ink on the recording medium. It is a feature.

  The ink set for ink jet recording according to the present invention includes (1) the liquid composition, (2) a coloring material and a liquid medium, and reacts with the liquid composition by contact with the liquid composition. It is characterized by being combined with a colored ink.

  A recording unit according to the present invention includes a liquid composition container that contains the liquid composition, and an ink container that contains a colored ink that reacts with the liquid composition upon contact with the liquid composition. And an ink jet recording head for applying energy to the liquid composition and the colored ink to discharge the liquid composition and the colored ink, respectively.

  The ink cartridge according to the present invention includes a liquid composition container that contains the liquid composition, a coloring material, and a liquid medium, and reacts with the liquid composition by contact with the liquid composition. And an ink containing portion containing colored ink.

  An ink jet recording apparatus according to the present invention includes a liquid composition container that contains a liquid composition, and a colored ink container that contains a colored ink that reacts with the liquid composition upon contact with the liquid composition. And an ink jet recording apparatus for applying energy to the liquid composition and the colored ink to discharge the liquid composition and the colored ink, respectively. It is characterized by being a liquid composition.

  An ink set for inkjet recording according to the present invention includes (1) a color ink containing a color material, a liquid medium, a polyvalent metal salt, and a substance selected from reducing sugars having 4 or more carbon atoms, and (2) A black ink containing a color material and a liquid medium and reacting with the color ink by contact with the color ink is combined.

  In the ink jet recording method according to the present invention, (i) energy for causing ink to be ejected is applied to the black ink included in the ink set, and the black ink is ejected toward the recording medium to be applied onto the recording medium. And (ii) applying energy to the color ink included in the ink set to eject the ink, ejecting the color ink toward the recording medium, and applying the energy onto the recording medium. And the steps (i) and (ii) are performed such that a contact state between the black ink and the color ink is formed on the recording medium.

  The recording unit according to the present invention is configured to discharge energy by applying energy to an ink storage unit that stores each of the inks constituting the ink set and ink supplied from the ink storage unit. And an ink jet recording head.

  The ink cartridge according to the present invention includes an ink storage portion that stores each of the inks constituting the ink set.

  An ink jet recording apparatus according to the present invention includes an ink containing portion containing an ink set composed of at least a black ink and a color ink, and applying ink to the ink supplied from the ink containing portion by applying energy. In the ink jet recording apparatus in which the ink jet recording head for discharging each is mounted, the ink set is the ink set.

  The inkjet ink according to the present invention includes (a) a polyvalent metal salt, (b) a substance selected from reducing sugars having 4 or more carbon atoms, (c) a liquid medium, and (d) a coloring material. It is characterized by this.

  According to the present invention, there is provided a liquid composition, ink jet ink, which has water resistance, good print quality, can form an image with reduced color bleeding in the formation of a color image, and can achieve a long life of the ink jet recording head. Ink, ink set for ink jet recording, ink jet recording method, recording unit, ink cartridge, and ink jet recording apparatus can be provided.

  Hereinafter, the present invention will be described in more detail with reference to preferred embodiments.

[Embodiment 1]
As a specific embodiment of the present invention, a liquid composition for ink jet recording that reacts when contacted with a colored ink, and comprises (a) a polyvalent metal salt and (b) a reducing sugar having 4 or more carbon atoms. A liquid composition comprising a selected substance and (c) a liquid medium is used, and the liquid composition is brought into contact with a colored ink used for normal recording on the recording medium. As described above, recording is performed by applying a liquid composition and a colored ink onto a recording medium.

  Hereinafter, the first embodiment will be described. The liquid composition used above is preferably one that does not affect the color tone of the colored ink in the recorded image.

  First, the polyvalent metal salt (a) constituting the liquid composition used in the above embodiment will be described. Examples of the polyvalent metal salts include inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid, organic acids such as acetic acid and hydroxycarboxylic acid, and magnesium salts, calcium salts, barium salts, iron (II) such as polyol phosphate esters. ) Salt, copper (II) salt, zinc salt and aluminum salt. Among them, preferred are magnesium nitrate and calcium salts, magnesium sulfate and calcium salts, magnesium chloride and calcium salts, magnesium acetate and calcium salts, magnesium hydroxycarboxylate and calcium, which are highly soluble in a liquid medium. Salts, and magnesium and calcium salts of polyol phosphates.

  Specific examples of the hydroxycarboxylic acid include lactic acid, aldanic acids (polyoxydicarboxylic acids) such as malic acid, citric acid and tartaric acid, and aldonic acids such as gluconic acid. Is not to be done. Among these hydroxycarboxylic acids, it is preferable to use a polyvalent metal salt of aldonic acid that is excellent in solubility and safety.

  Hereinafter, the polyvalent metal salt of aldonic acid will be described in detail.

  Aldonic acid is a polyoxycarboxylic acid corresponding to a carboxylic acid group obtained by oxidizing an aldehyde group of aldose, and is represented by the following general formula. Since aldonic acid binds to polyvalent metal ions such as magnesium and calcium to form a soluble polyvalent metal salt, it can be suitably used as a constituent material of the liquid composition of the present invention.

  As described above, since aldonic acid has an asymmetric carbon atom, there are many optical isomers. Aldonic acids having 5 or more carbon atoms (n = 3 or more in the above general formula) are rarely present alone in an aqueous solution. Usually, a part of aldonic acid is a γ- or δ-position hydroxyl group. A lactone is formed in between, becoming γ-aldonolactone and δ-aldonolactone, respectively, and is said to exist as an equilibrium mixture of aldonic acid, γ-aldonolactone and δ-aldonolactone. Also, aldonic acids having 4 carbon atoms (n = 2 in the above general formula) are rarely present alone in an aqueous solution, and usually a part of aldonic acid forms a lactone with a hydroxyl group at the γ-position. Each of them becomes γ-aldonolactone and is said to exist as an equilibrium mixture of two of aldonic acid and γ-aldonolactone.

  Aldonic acids are classified by the number of carbon atoms, those having 4 carbon atoms (n = 2 in the above general formula) are tetronic acids; those having 5 carbon atoms (n = 3 in the above general formulas) are pentonic acids; Those (n = 4 in the above general formula) are collectively referred to as hexonic acid. Specific examples of aldonic acid include, for example, glycolic acid having 2 carbon atoms (n = 0 in the above general formula) (also known as hydroxyacetic acid); glyceric acid having 3 carbon atoms (n = 1 in the above general formula); carbon Erythronic acid and threonic acid having a number of 4 (n = 2 in the above general formula); Ribbon acid, alabonic acid, xylonic acid and lyxonic acid having 5 carbons (n = 3 in the above general formula); 6 carbons ( N = 4) gluconic acid, aronic acid, altronic acid, mannonic acid, gulonic acid, idonic acid, galactonic acid and taronic acid in the above general formula; glucoheptonic acid having 7 carbon atoms (n = 5 in the above general formula), etc. In some cases, D-form, L-form and DL-form each exist.

  Among aldonic acids suitable as a constituent material of the liquid composition according to the present invention, particularly preferred gluconic acid (n = 4 in the above general formula) will be described.

  Gluconic acid is widely used as a food additive and is safe for the human body. Gluconic acid is rarely present alone in an aqueous solution, and usually a part of gluconic acid forms a lactone with a hydroxyl group at the γ-position or δ-position, respectively, and γ-gluconolactone or δ -Gluconolactone is said to exist as a three-way equilibrium mixture of gluconic acid, γ-gluconolactone and δ-gluconolactone. There are D-form, L-form and DL-form of gluconic acid, and any of them may be used, but generally D-gluconic acid in D-form can be easily obtained. In addition, as optical isomers of gluconic acid, there are, for example, alloic acid, altronic acid, mannonic acid, gulonic acid, idonic acid, galactonic acid, and taronic acid, etc. You may do it.

  Examples of the polyvalent metal salt of gluconic acid include magnesium gluconate, calcium gluconate, barium gluconate, iron (II) gluconate and copper (II) gluconate. In the present invention, gluconic acid is used. It is particularly preferable to use magnesium or calcium gluconate. These compounds can be used alone or in combination of two or more.

  Next, the polyvalent metal salt of polyol phosphate is described.

  Examples of polyol phosphate esters include polyol, monosaccharide, oligosaccharide and polysaccharide phosphate esters. Specifically, for example, glycerophosphate, glucose-1-phosphate, glucose-6-phosphate, mannose-6-phosphate, galactose-6-phosphate, fructose-6-phosphate, glucose-1,6 -Diphosphoric acid, fructose-1,6-diphosphoric acid, ascorbic acid phosphoric acid, sucrose phosphoric acid, sorbitol phosphoric acid, phosphorylated polyglycerin, phosphorylated polyethylene glycol, etc. are mentioned.

  Among these, glycerophosphoric acid particularly preferable in the present embodiment will be described.

  In glycerophosphoric acid, there are isomers of α-glycerophosphoric acid and β-glycerophosphoric acid. In the present invention, either isomer may be used or a mixture of isomers may be used. Examples of these polyvalent metal salts of glycerophosphate include magnesium glycerophosphate, calcium glycerophosphate, barium glycerophosphate, iron (II) glycerophosphate and copper (II) glycerophosphate, and in particular, magnesium glycerophosphate and It is preferred to use calcium glycerophosphate.

  In the liquid composition according to the present invention, the total content of the compound selected from at least one of the polyvalent metal salts as described above is to improve the bleed reduction effect and the durability of the head. Is preferably 0.005 to 20% by mass with respect to the total amount of the liquid composition, and more preferably 0.05 to 12% by mass with respect to the total amount of the liquid composition.

  Next, the substance selected from (b) reducing sugars having 4 or more carbon atoms constituting the liquid composition according to the present invention will be described.

  Examples of reducing sugars having 4 or more carbon atoms include D-glucose, D-mannose, D-galactose, D-fructose, D-arabinose, D-ribose, D-xylose, and D-erythrose.

  The total content of the substance selected from the reducing sugars having 4 or more carbon atoms in the liquid composition is based on the total amount of the liquid composition in order to achieve a better kogation reduction effect and a longer head life. It is preferable to make it contain in 0.005-20 mass%, and also 0.05-12 mass% with respect to the liquid composition whole quantity.

  The ink jet recording method used in the present embodiment is an ink jet recording method in which energy for ejecting ink is applied and ink is ejected to record an image on a recording medium, and has the above-described configuration. Recording is performed by using a liquid composition and a colored ink as described below in combination, and applying these to a recording medium. Below, the coloring material used for colored ink is demonstrated.

  Next, the coloring ink used with the above-described liquid composition in the above-described embodiment will be described.

  The colored ink contains at least a coloring material and a liquid medium, but the ink is a polyvalent metal salt in the liquid composition when brought into contact with the specific liquid composition described above. It reacts with the valent metal ions to cause aggregation or precipitation of the coloring material in the colored ink, or to increase the viscosity of the colored ink. Pigments and dyes can be used as coloring materials in the colored ink. As the pigment, any pigment such as an inorganic pigment or an organic pigment can be used, and specific examples include the following.

  Carbon black, C.I. I. Pigment Yellow 1, 2, 3, 12, 13, 14, 16, 17, 73, 74, 75, 83, 93, 95, 97, 98, 114, 128, 129, 151, 154 and 195, C.I. I. Pigment Red 5, 7, 12, 48 (Ca), 48 (Mn), 57 (Ca), 57: 1, 57 (Sr), 112, 122, 123, 168, 184 and 202, C.I. I. Pigment Blue 1, 2, 3, 15: 3, 15:34, 16, 22 and 60, C.I. I. Wat blue 4 and 6 etc. are mentioned.

  When the pigments listed above are used as the color material, it is preferable to use a dispersant in order to stably disperse the pigment in the colored ink. Examples of the dispersant include a polymer dispersant and a surfactant-based dispersant. Specific examples of the polymer dispersant include, for example, polyacrylate, styrene-acrylic acid copolymer salt, styrene-methacrylic acid copolymer salt, styrene-acrylic acid-acrylic acid ester copolymer salt, styrene- Maleic acid copolymer salt, acrylic acid ester-maleic acid copolymer salt, styrene-methacrylsulfonic acid copolymer salt, vinylnaphthalene-maleic acid copolymer salt, β-naphthalenesulfonic acid formalin condensate salt, polyvinylpyrrolidone , Polyethylene glycol and polyvinyl alcohol.

  Among these, it is particularly preferable to use those having a weight average molecular weight of 1,000 to 30,000 and an acid value of 100 to 430. Examples of the surfactant dispersant include lauryl benzene sulfonate, lauryl sulfonate, lauryl benzene carboxylate, lauryl naphthalene sulfonate, aliphatic amine salt, and polyethylene oxide condensate. These dispersants are preferably used in an amount of pigment weight: dispersant weight = 10: 5 to 10: 0.5.

  Self-dispersion that enables self-dispersion by introducing a water-soluble group on the surface of carbon black as described in JP-A-5-186704 and JP-A-8-3498 as a coloring material for colored ink Dispersed carbon black can also be used as a coloring material. When self-dispersing carbon black as described above is used as the color material, it is not always necessary to use the dispersant as described above. Does not require the use of a dispersant.

  When the above-described pigment ink comes into contact with the liquid composition according to the present embodiment described above, the pigment in the pigment ink is caused by salting out action of polyvalent metal ions in the liquid composition. Aggregates and precipitates quickly, and the fixing of the color material in the pigment ink to the recording medium is accelerated. As a result, it is considered that bleeding is less likely to occur even when two or more different colors of ink are applied adjacently. In the present embodiment, an ink jet recording liquid composition that reacts when it comes into contact with the colored ink is used. The “reaction” between the colored ink and the liquid composition is a pigment based on the above-described action. The destabilization of the dispersed state is also included in the “reaction”.

  In the case where a dye is used for the color material constituting the colored ink used in the present embodiment, a water-soluble dye is preferably used. For example, dyes such as direct dyes, acid dyes, basic dyes, and disperse dyes can be used. As a preferable color ink containing a dye, the contact with the liquid composition according to the present embodiment having the above-described configuration causes precipitation of the dye due to a salting-out effect or water damage caused by a reaction between a polyvalent metal ion and the dye. Those in which the fixing of the dye in the colored ink to the recording medium proceeds at a high speed by the formation of a soluble or water-insoluble salt or compound or the combination of these actions are preferably used. As a dye that can be used for such a colored ink, when it comes into contact with the liquid composition according to the present embodiment, it reacts with the polyvalent metal salt in the liquid composition to form an insoluble salt or compound. Therefore, it is preferable to use a dye having at least one carboxyl group in the molecule. Specifically, although it is preferable to use the dye which has a structure as listed in the following exemplary compounds 1-30, this invention is not limited to these. Moreover, M in the exemplary compounds 1 to 5 is any one of alkali metal, ammonium, and organic ammonium.

本実施の形態で使用する着色インクに含有させる色材としては、これらの染料や、或は前記した顔料を１種類で用いても良く、２種以上を組合わせて用いても良い。又、これらの染料及び顔料の濃度は、通常、インク全量に対して０．１〜２０質量％の範囲から適宜に選択される。

As the coloring material to be contained in the colored ink used in the present embodiment, these dyes or the above-mentioned pigments may be used alone or in combination of two or more. Further, the concentrations of these dyes and pigments are usually appropriately selected from the range of 0.1 to 20% by mass with respect to the total amount of ink.

  Next, the liquid medium used in the liquid composition according to the present embodiment and the color ink used in combination will be described.

  As the liquid medium, it is preferable to use water and a water-soluble organic solvent in combination. In this case, it is desirable to use deionized water instead of general water containing various ions. The water content is preferably in the range of 35 to 96% by mass with respect to the total amount of ink.

  The water-soluble organic solvent adjusts the viscosity of the ink to an appropriate viscosity that is preferable for use and delays the drying speed of the ink, or increases the solubility of the coloring material and prevents clogging of the nozzles of the recording head, etc. Used for various purposes. Specific examples of the aqueous organic solvent include carbon such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol and n-pentanol. Alkyl alcohols of 1 to 5; amides such as dimethylformamide and dimethylacetamide; ketones or ketoalcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; diethylene glycol, triethylene glycol, tetraethylene glycol, Oxyethylene or oxypropylene copolymers such as dipropylene glycol, tripropylene glycol, polyethylene glycol and polypropylene glycol Alkylene glycols wherein the alkylene group contains 2 to 6 carbon atoms, such as ethylene glycol, propylene glycol, trimethylene glycol, triethylene glycol and 1,2,6-hexanetriol; glycerin; trimethylolethane and trimethylolpropane; Lower alkyl ethers such as ethylene glycol monomethyl (or ethyl) ether, diethylene glycol monomethyl (or ethyl) ether and triethylene glycol monomethyl (or ethyl) ether; triethylene glycol dimethyl (or ethyl) ether and tetraethylene glycol dimethyl (or ethyl) ) Lower dialkyl ethers of polyhydric alcohols such as ethers; monoethanolamine, diethanolamine and triethanolamine Kanoruamin like; sulfolane, N- methyl-2-pyrrolidone, 2-pyrrolidone and 1,3-dimethyl-2-imidazolidinone. The above water-soluble organic solvents may be used alone or as a mixture.

  Further, in order to stabilize the solubility of the dye in the ink and the dispersibility of the pigment by keeping the pH value of the colored ink constant, a pH adjusting agent may be contained in the colored ink. Specific examples of the pH adjuster include hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide and ammonium hydroxide, sulfates such as lithium sulfate, sodium sulfate, potassium sulfate and ammonium sulfate, and carbonates. Lithium, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, ammonium carbonate, ammonium carbonate, and other carbonates, lithium phosphate, monosodium phosphate, disodium phosphate, trisodium phosphate, monopotassium phosphate , Phosphates such as dipotassium phosphate, tripotassium phosphate, monoammonium phosphate, diammonium phosphate, triammonium phosphate, acetates such as lithium acetate, sodium acetate, potassium acetate and ammonium acetate, hydrochlorides, etc. Is mentioned.

  These pH adjusting agents may be added to the liquid composition described above. These may be used alone in the liquid composition and the colored ink, but more preferably, two or more kinds of pH adjusters are selected and used in combination. In particular, in order to keep the pH stable, increase the dissolution stability of the water-soluble dye contained in the colored ink, and prevent problems such as nozzle clogging, these pH adjusters are preferably used. 0.1-10 mass%, More preferably, it adds in the range of 1-8 mass%.

  Furthermore, in the liquid composition according to the present embodiment and in the colored ink used in combination therewith, in addition to the above components, various conventionally known general additives such as a viscosity modifier, Nozzle drying inhibitors such as fungicides, preservatives, antioxidants, antifoaming agents and urea can be used in combination as appropriate.

  Moreover, the suitable range of the physical properties of the liquid composition according to the present embodiment and the color ink to be used in combination is preferably a pH value around 25 ° C., preferably 3 to 12, more preferably 4 to 10, and the surface tension is Preferably it is 10-60 mN / m (dyn / cm), More preferably, it is 15-50 mN / m (dyn / cm), A viscosity becomes like this. Preferably it is 1-30 cps, More preferably, it is the range of 1-10 cps.

  In the ink jet recording method according to the present embodiment, a liquid composition having the configuration as described above and a colored ink are used in combination, and both are brought into contact with each other and reacted to be applied to a recording medium for recording. It is characterized by performing. The recording medium used at this time is not particularly limited. However, the ink jet recording method according to the present embodiment has a remarkable bleed reduction effect when an image is formed on so-called plain paper such as copy paper and bond paper, which has been used conventionally. These are preferably used.

  The ink jet recording method according to the present embodiment can be any system as long as it is a system that ejects ink by applying energy necessary for ejection to the ink and records an image on a recording medium. There may be, and it is not specifically limited. However, in particular, when an ink jet recording method that uses thermal energy for ink ejection is used, when an image is formed using the recording method according to the present embodiment, the so-called “burning” is effectively generated. An excellent effect that it can be suppressed is obtained. As an ink jet recording method using thermal energy, for example, a so-called on-demand bubble jet method in which droplets are ejected using bubbles generated by thermal energy can be cited.

  In the ink jet recording method according to the present embodiment, the liquid composition having the configuration as described above and the colored ink are used in combination, and these are applied and recorded so as to contact and react on the recording medium. In the order in which the liquid composition and the colored ink are applied onto the recording medium when forming an image, the liquid composition is first and the colored ink is first. Either is fine. That is, in the present embodiment, regardless of the order or method of application, the liquid composition and the colored ink are applied to the recording medium so that a contact state between the liquid composition and the colored ink is formed. Good character quality, fixability, water resistance and bleeding suppression effect of the formed image are achieved. This is because, when the liquid composition and the colored ink come into contact with each other on the recording medium, the polyvalent metal ions resulting from the polyvalent metal salt constituting the liquid composition, and the pigment and dye in the ink are mixed. This is thought to be due to aggregation, precipitation, or thickening of the colored ink.

  In particular, from the viewpoint of further improving the image density and fixability, for example, it is more preferable to apply the liquid composition after applying the color ink, and then apply the color ink again. Alternatively, the colored ink may be applied on the recording medium after the liquid composition is applied on the recording medium, and the liquid composition may be applied on the recording medium.

  In addition, when the application of the liquid composition is performed prior to the application of the colored ink, the time from the attachment of the liquid composition to the recording medium to the application of the colored ink is not particularly limited. However, in order to make the present invention more effective, for example, within a few seconds, particularly preferably within one second. The same applies to the case where the liquid composition and the colored ink are applied on the recording medium in the reverse order. Furthermore, as another embodiment for applying the liquid composition and the colored ink to the recording medium, the method shown in FIG. 16 can be used. In such a form, the liquid composition 804 and the colored ink 805 are ejected from the respective recording heads 801 and 802 of the ink jet recording apparatus, and both are mixed immediately after ejection, and the mixture 806 is applied onto the recording medium 803. To do.

  According to the inkjet recording method according to the present embodiment, as described above, the liquid composition according to the present embodiment composed of specific constituent components is used regardless of the order and method of applying the liquid composition and the colored ink. By applying on the recording medium so as to form a contact state with the colored ink, it is possible to achieve good character quality of the image formed by the colored ink, to improve the fixability and water resistance, Furthermore, the occurrence of bleeding when a color image is formed is effectively suppressed. This is because the agglomerates are formed by mixing the polyvalent metal ions contained in the liquid composition and the pigment and / or dye in the colored ink on the recording medium. It is considered that an effect can be obtained.

  In the ink jet recording method according to the present embodiment, when recording is performed by applying the liquid composition and the colored ink onto a recording medium by the method described above, the colored ink and the liquid composition in the image forming region are recorded. The ratio of the applied amount per unit area of the recording medium may be 1: 1, but may be colored ink: liquid composition = 10: 1 to 10:10. Here, the adjustment of the ratio of the applied amount of the colored ink and the liquid composition per unit area on the recording medium in the image forming region is specifically, for example, onto the recording medium of the liquid composition and the colored ink. Is applied in an ink jet recording method, the number of pixels of the liquid composition deposited on the recording medium is controlled to be in the range of 10 to 100% of the number of colored ink pixels deposited on the recording medium. And when the liquid composition and the colored ink are applied by the ink jet recording method, the liquid composition discharge amount is controlled to be smaller than the color ink discharge amount, and the liquid composition and the color ink are deposited on the recording medium. It can be carried out by a method of making the range of 10 to 100% of the number of pixels of the colored ink, or a method combining them.

  Hereinafter, the ink jet recording method in the present embodiment and the ink jet recording apparatus to which such a method is applied will be described in more detail.

  In the ink jet recording method according to the present embodiment, as a method of attaching the liquid composition and the colored ink of the present embodiment on the recording medium, energy is applied to the ink, thereby causing the ink to be ejected, An ink jet recording method for forming an image on a recording medium is used. As the recording method, various conventionally known ink jet methods (for example, an ink jet recording method using mechanical energy due to deformation of a piezoelectric element) are used. be able to. However, it is particularly preferable to use an ink jet recording method in which ink is ejected using the action of thermal energy.

  That is, as described above, for the purpose of suppressing mixed color bleeding (bleeding) between different colors and improving the water resistance of the recorded matter, the liquid composition containing the polyvalent metal salt is used in combination with the colored ink, and the liquid composition is discharged. The occurrence of kogation that occurs when an image is formed using an ink jet recording method that utilizes thermal energy, and the deterioration in image quality caused thereby is characterized by using the liquid composition according to the present embodiment described above. It is effectively suppressed by the ink jet recording method. Furthermore, in the conventional method, the solution used with the colored ink for the purpose of suppressing bleeding and improving the water resistance of the recorded matter is repeatedly ejected from the recording head, so that the heater (heat generating element substrate) is applied with heat energy. The outermost surface protective layer made of metal and / or metal oxide, such as tantalum or tantalum oxide, is dissolved, which causes the heater to break and discharge becomes impossible. In addition, there is a kogation on the heater, which affects the quality of the formed image. However, such a problem is effectively prevented.

  In addition, as an ink jet recording apparatus using the liquid composition according to the above-described embodiment, a liquid composition container that contains the liquid composition, and a colored ink that contains a colored ink The container and an ink jet recording head for discharging the liquid composition and the colored ink are mounted. Yet another preferred embodiment is an apparatus for ejecting a liquid composition and colored ink by the action of thermal energy, wherein the liquid composition and the color in the flow path led from the liquid composition container and the colored ink container are colored. An ink jet recording apparatus having an ink jet recording head having a heater for applying thermal energy to the ink and means for applying a pulsed electric signal to the heater in accordance with recording information can be mentioned. Furthermore, the heater is provided with an outermost surface protective layer containing a metal and / or a metal oxide. In particular, the metal and / or metal oxide is an oxide of tantalum and / or tantalum. In the case of the ink jet recording apparatus of the aspect which is a thing, the remarkable effect of this invention is show | played.

  Furthermore, as an embodiment in which the remarkable effects of the present invention are exhibited, there is an apparatus in which the energy applied to the heater is controlled as follows. That is, when the amount of energy input to the heater for discharging the liquid composition from the recording head is Eop, and the minimum amount of energy input for discharging ink from the recording head is Eth, the value of Eop / Eth (= According to the ink jet recording apparatus in which the [gamma] value is controlled to satisfy the following relationship, the remarkable effects of the present invention can be obtained.

1.10 ≦ Eop / Eth ≦ 1.90
Hereinafter, an inkjet recording apparatus to which an inkjet recording method for ejecting ink using thermal energy is applied will be described with reference to the drawings.

  An example of a head configuration which is a main part of an ink jet recording apparatus using thermal energy is shown in FIGS. FIG. 1 is a cross-sectional view of the recording head 13 along the ink flow path, and FIG. 2 is a cross-sectional view taken along line AB in FIG.

  The recording head 13 is obtained by bonding a heating element substrate 15 to glass, ceramic, silicon, polysulfone, a plastic plate or the like having a flow path (nozzle) 14 through which ink passes. The heating element substrate 15 is formed of a protective layer 16-1 formed of silicon oxide, silicon nitride, silicon carbide, or the like, a metal such as platinum, or an oxide of metal such as an oxide of platinum, particularly tantalum or an oxide of tantalum. The outermost surface protective layer 16-2 to be formed, electrodes 17-1 and 17-2 formed of aluminum, gold, aluminum-copper alloy, etc., and formed from a high melting point material such as hafnium boride, tantalum nitride and tantalum aluminum. And a heat storage layer 19 formed of silicon oxide, aluminum oxide or the like, and a substrate 20 formed of a material with good heat dissipation such as silicon, aluminum, or aluminum nitride.

In the ink jet recording apparatus using thermal energy, when a pulsed electric signal is applied to the electrodes 17-1 and 17-2 of the head 13, the region (heater) indicated by n of the heating element substrate 15 rapidly. Heat is generated, bubbles are generated in the ink 21 in contact with the surface, the meniscus 23 protrudes due to the pressure, the ink 21 is ejected through the nozzles 14 of the recording head 13, and becomes ink droplets 24 from the ejection orifices 22. Fly toward the medium 25. FIG. 3 shows an external view of an example of a multi-head in which a large number of heads shown in FIG. 1 are arranged. This multi-head is made by adhering a glass plate 27 having multi-nozzles 26 and a heating head 28 similar to that described in FIG.
(Amount of energy applied to the heater)
Next, the γ value will be described. The γ value is a factor that represents the ratio of the energy that the bubble jet head actually inputs to the critical energy that can eject the last ink or liquid composition. That is, when the pulse width applied to the bubble jet head is P (the total width when a plurality of pulses are divided and applied), the applied voltage is V, and the heater resistance is R, the input energy E is: It is represented by the following formula (A).

E = P × V ² / R (A)
At this time, if the bubble jet head uses Eth as the minimum energy required for the heater that can discharge the ink or liquid composition, and the input energy when actually driving is Eop, the γ value can be expressed by the following equation: It is given by (B).

γ = Eop / Eth (B)
For example, the following two methods (1) and (2) are practically used as a method for obtaining a γ value suitable for discharging a liquid composition from the driving conditions of the bubble jet head.
(1) When the pulse width is fixed First, with the given pulse width, the bubble jet head finds and drives an appropriate voltage for discharging the liquid composition. Next, the voltage is gradually lowered to find a voltage at which the discharge of the liquid composition stops, and the minimum dischargeable voltage immediately before this voltage is set to Vth. If the voltage actually used for driving is Vop, the γ value can be obtained by the following equation (C).

γ = (Vop / Vth) ² (C)
(2) When the voltage is fixed First, with a given voltage, the bubble jet head finds and drives an appropriate pulse width for discharging the liquid composition. Next, the pulse width is gradually shortened to find a pulse width at which the discharge of the liquid composition stops. Let Pth be the minimum pulse width that can be ejected immediately before this pulse width. If the pulse width actually used in driving is Pop, the γ value can be obtained by the following equation (D).

γ = Pop / Pth (D)
In addition, the voltage value here is a voltage actually applied to the heater unit in order to cause the bubble jet heater to generate heat. Since the voltage applied from the outside of the head may drop due to a contact or wiring resistance, it cannot be used for calculating the γ value in a strict sense.

  However, when Vth and Vop are measured from the outside of the head, these voltage fluctuations are included in both values. Therefore, unless the voltage fluctuations are large, these values are used directly to calculate the γ value. Even if it is calculated, there is little error, and therefore the value obtained by this can be used as the γ value for convenience.

  Also, when recording is performed with an actual printer, it is necessary to note that the voltage to one heater may fluctuate due to this influence because a plurality of heaters are driven. Further, from the above formulas (A) and (B), the square of V and P seem to be inversely proportional to the same γ value, but in reality, the electrical pulse waveform is not rectangular. There are problems such as thermal problems such as different heat diffusion around the heater if the pulse waveform is different, bubble jet specific problems such as changing the heat flux from the heater to the ink if the voltage is different, etc. The square of V and P are not simply related. Therefore, the methods described in the above (1) and (2) must be handled independently, and it should be noted that conversion from one value to the other by calculation causes an error. Must. In the present invention, unless otherwise specified, the value obtained by the above method (1) is defined as the γ value.

  For stable ejection of ink or liquid composition, it is common to drive the ink jet recording apparatus under conditions such that the γ value obtained as described above is about 1.12 to 1.96. It is. However, in the present embodiment in which thermal energy is applied to the liquid composition having the above-described configuration and ejected from the recording head, the γ value is in a predetermined range, specifically, the γ value is 1.10. If the ink jet recording apparatus is driven within the range of 1.90, the adhesion of kogation to the heater due to the discharge of the liquid composition having the above configuration is further prevented, and the recording head is further increased in length. It is preferable because the life can be extended.

  When the γ value when the thermal energy is applied to the liquid composition according to the present embodiment and ejected from the recording head is within the above range, the adhesion of kogation to the heater can be particularly effectively prevented. The reason why the life of the recording head is extended is not clear, but the present inventors consider as follows.

  That is, first, when the ink jet recording apparatus is driven so that the γ value falls within the above-described range, the reducing sugar having 4 or more carbon atoms contained in the liquid composition according to the present embodiment is obtained. As a result of protecting the outermost surface protective layer of the heater, it is considered that corrosion of the metal constituting the outermost surface protective layer and / or the oxide of the metal is effectively prevented. Secondly, if the ink jet recording apparatus is driven so that the γ value falls within the above-described range, energy is not excessively supplied to the heater and the surface temperature of the heater does not become excessively high. In addition, the alkalinity becomes stronger due to the polyvalent metal ions derived from the polyvalent metal salt (a) added to the liquid composition for the purpose of improving the water resistance of the obtained recorded matter, and the resulting metal erosion (dissolution). It is thought that this is because it does not occur excessively.

  FIG. 4 shows an example of an ink jet recording apparatus incorporating the recording head described above.

  In FIG. 4, reference numeral 61 denotes a blade as a wiping member, one end of which is held and fixed by a blade holding member, and forms a cantilever. Such a blade 61 is disposed at a position adjacent to a recording area by the recording head 65, and in the illustrated example, is held in a form protruding in the moving path of the recording head 65.

  Reference numeral 62 denotes a cap on the projection port surface of the recording head 65, which is disposed at a home position adjacent to the blade 61, moves in a direction perpendicular to the moving direction of the recording head 65, contacts the ink ejection port surface, and performs capping. The structure to perform is provided. Further, reference numeral 63 denotes an ink absorber provided adjacent to the blade 61 and, like the blade 61, is held in a form protruding in the moving path of the recording head 65. The blade 61, the cap 62, and the ink absorber 63 constitute an ejection recovery unit 64, and the blade 61 and the ink absorber 63 remove moisture, dust, and the like from the ejection port surface.

  Reference numeral 65 denotes a recording head which has discharge energy generating means and performs recording by discharging ink onto a recording medium facing the discharge port surface on which the discharge port is arranged. Reference numeral 66 denotes a movement of the recording head 65 by mounting the recording head 65. It is a carriage for performing. The carriage 66 is slidably engaged with the guide shaft 67, and a part of the carriage 66 is connected to a belt 69 (not shown) driven by a motor 68. As a result, the carriage 66 can move along the guide shaft 67, and the recording area and its adjacent area can be moved by the recording head 65.

  51 is a paper feeding section for inserting a recording medium, and 52 is a paper feed roller driven by a motor (not shown). With these configurations, the recording medium is fed to a position facing the 65 discharge port surface of the recording head, and discharged as a recording progresses as the recording progresses.

  In the above configuration, when the recording head 65 finishes recording and returns to the home position, the cap 62 of the ejection recovery unit 64 is retracted from the moving path of the recording head 65, but the blade 61 protrudes into the moving path. Yes. As a result, the ejection port of the recording head 65 is wiped.

  When the cap 62 is in contact with the ejection surface of the recording head 65 to perform capping, the cap 62 moves so as to protrude into the moving path of the recording head. When the recording head 65 moves from the home position to the recording start position, the cap 62 and the blade 61 are at the same position as that at the time of wiping described above. As a result, the ejection port surface of the recording head 65 is wiped even during this movement. The above-mentioned movement of the recording head to the home position is not only at the end of recording or at the time of ejection recovery, but also to the home position adjacent to the recording area at a predetermined interval while the recording head moves the recording area for recording. Then, the wiping is performed with this movement.

  FIG. 5 is a diagram showing an example of an ink cartridge 45 that contains ink supplied to the recording head via an ink supply member, for example, a tube. Here, reference numeral 40 denotes an ink storage portion, for example, an ink bag, which stores supply ink, and a rubber plug 42 is provided at the tip thereof. By inserting a needle (not shown) into the stopper 42, the ink in the ink bag 40 can be supplied to the head. An ink absorber 44 receives waste ink. The ink container preferably has a liquid contact surface made of polyolefin, particularly polyethylene.

  The ink jet recording apparatus according to the present embodiment is not limited to the recording head and the ink cartridge that are separate from each other as described above, and may be an integrated recording head as shown in FIG. In FIG. 6, reference numeral 70 denotes a recording unit, in which an ink containing portion containing ink, for example, an ink absorber is housed, and a head portion in which the ink in the ink absorber has a plurality of orifices. 71 is ejected as ink droplets. Polyurethane is preferably used as the material for the ink absorber. Alternatively, a structure in which the ink container is an ink bag with a spring or the like inside without using an ink absorber may be used. Reference numeral 72 denotes an atmosphere communication port for communicating the inside of the cartridge with the atmosphere. The recording unit 70 is used in place of the recording head 65 shown in FIG. 4 and is detachable from the carriage 66.

  When a color image is formed by the ink jet recording method according to the present embodiment, for example, a recording apparatus in which five recording heads shown in FIG. FIG. 7 shows an example. Reference numerals 91, 92, 93, and 94 denote recording heads for ejecting yellow, magenta, cyan, and black inks, respectively. Reference numeral 95 denotes a head for discharging the liquid composition. The head is disposed in the above-described recording apparatus and ejects ink of each color according to a recording signal. Further, for example, prior to the discharge of each color ink, the liquid composition is adhered to at least an image forming portion where the ink adheres to the recording medium.

  FIG. 7 shows an example in which five recording heads are used. However, the present invention is not limited to this. As shown in FIG. 8, one recording head uses yellow 101, magenta 102, cyan 103 and black 104, and liquid. A case where the composition 105 is separated from the liquid flow path is also preferable. Of course, the heads may be arranged so that the recording order of each ink and liquid composition is opposite to the above order.

  Specific examples of the arrangement of the ink jet recording head that is preferably used in the present embodiment include three types as shown in FIGS. 9 to 11, reference numerals 111 to 114, 121 to 124, and 131 to 134 denote recordings for ejecting ink of each color of yellow (Y), magenta (M), cyan (C), and black (Bk), respectively. Head. Reference numerals 115, 125, and 135 denote recording heads for discharging the liquid composition (S). The recording heads are arranged on the carriage in the same manner as shown in FIG. 7 (depending on the configuration example). Each recording head is arranged in a recording apparatus as described above, and ejects ink of each color according to a recording signal. The liquid composition is attached to an image region where at least each color ink adheres to the recording medium before or after the liquid composition. Each recording head is moved in the direction of arrow (1) by the carriage, and the recording medium is moved in the direction of arrow (2) by a paper feed roller or the like.

  First, in the first configuration example shown in FIG. 9, recording heads for S (115), Bk (114), C (113), M (112), and Y (111) are arranged in parallel on the carriage. Has been. In the second configuration example shown in FIG. 10, the recording heads for the liquid composition and black ink arranged in parallel, and these recording heads are arranged in parallel, and Y (121) arranged in series with each other. , M (122) and C (123) recording heads. Here, the ejection volume per dot of each recording head is not necessarily the same, and the ejection volume per dot of each recording head so that optimum recording is performed depending on the composition of the liquid composition. (Vd) may be adjusted. Preferably, S, Y, M, and C have the same Vd and Bk is doubled. However, the present invention is not limited to this.

  Furthermore, in the third configuration example shown in FIG. 11, the discharge volumes for Bk (134), S (135), Bk (134), C (133), M (132), and Y (131) having the same discharge volume are used. The recording heads are arranged in parallel on the carriage, and the black ink discharge amount can be double the discharge amount of the other liquid composition and the color ink. In the configuration example shown in FIG. 11, the discharge volumes (Vd) of S, Bk, Y, M, and C are not necessarily the same.

  As described above, in the present embodiment, the ratio of the applied amount per unit area of the recording medium to the liquid composition and the colored ink, particularly the magenta ink in the image forming area is 1: 1. However, it is also possible to use colored ink: liquid composition = 10: 1 to 10:10. The adjustment of the ratio of the applied amount of the liquid composition and the colored ink per unit area on the recording medium in the image forming region is specifically, for example, the number of pixels of the liquid composition attached on the recording medium is Method for controlling the number of pixels of the colored ink adhering to the recording medium to be in the range of 10 to 100%, the amount of liquid composition discharged when applying the liquid composition and the color ink The number of pixels of the liquid composition deposited on the recording medium is 10 to 100% of the number of pixels of the colored ink deposited on the recording medium. The amount of liquid composition may be controlled to be within a range, and the discharge amount of the liquid composition when applying the liquid composition and the color ink onto the recording medium may be made smaller than the discharge amount of the color ink.

[Embodiment 2]
Next, a specific second embodiment of the present invention will be described.

  In the present embodiment, (1) a color ink containing a color material, a liquid medium, a polyvalent metal salt, and a substance selected from reducing sugars having 4 or more carbon atoms, and (2) a color material and a liquid medium. A black ink and a color ink contained in the ink set, wherein the ink set for ink jet recording is combined with a black ink that reacts with the color ink by contact with the color ink. Are applied to form a contact state on the recording medium, and recording is performed.

  The ink set according to the present embodiment having the above-described configuration is intended to prevent bleeding between black ink and color ink, and is particularly effective for preventing bleeding between color inks such as yellow ink, magenta ink, and cyan ink. I have not taken any action. However, if the color ink is processed so as to have quick permeability even to sized plain paper, specifically, an ink design such as adding a surfactant to the color ink is performed. For example, it is effective for preventing bleeding between different color inks.

  First, the color ink constituting the ink set according to the present embodiment will be described.

  The color ink includes a color material, a liquid medium, a polyvalent metal salt, and a substance selected from reducing sugars having 4 or more carbon atoms. The polyvalent metal salt and the reducing sugar having 4 or more carbon atoms are as described in detail in the first embodiment.

  Next, the color material contained in the color ink constituting the ink set according to the present embodiment will be described.

  Examples of the color material include direct dyes, acid dyes, basic dyes, disperse dyes, and pigments, but the color material can maintain solubility without reacting even when formulated with a polyvalent metal salt. preferable. As such a coloring material, those listed below can be used.

  For example, C.I. I. Acid Yellow 23; I. Acid Red 52, 289; I. Acid Blue 9; I. Reactive Red 180; C.I. I. Direct Blue 189, 199; C.I. I. Basic yellow 1, 2, 11, 13, 14, 19, 21, 25, 32, 33, 36, 51; I. C. Basic Orange 2, 15, 21, 22; I. B. Basic Red 1, 2, 9, 12, 13, 37, 38, 39, 92; I. C. basic violet 1, 3, 7, 10, 14; I. Basic blue 1, 3, 5, 7, 9, 19, 24, 25, 26, 28, 29, 45, 54, 65; C.I. I. B. Basic Green 1, 4; I. B. Basic Brown 1, 12; I. Basic black 2, 8, etc. are mentioned, but it is not limited to these. These water-soluble dyes may be used alone or in combination of two or more. The concentration of these water-soluble dyes is preferably in the range of 0.1 to 20% by mass with respect to the total amount of ink.

  In addition to the components described above, the color ink constituting the ink set for inkjet recording according to the present embodiment preferably contains at least one surfactant. By containing the surfactant, it is possible to impart desired permeability and viscosity to the color ink. In other words, as described above, in the present embodiment, no particular measures are taken to prevent bleeding between color inks such as yellow ink, magenta ink, and cyan ink. By adding a surfactant to the ink, it is possible to obtain an ink having fast permeability even for sized plain paper. As a result, it is possible to prevent bleeding between the color inks, and there is no practically large deterioration in print quality.

  As the surfactant, a conventionally known surfactant such as an anionic surfactant, a cationic surfactant, and a nonionic surfactant may be used. Among these, it is preferable to use a nonionic surfactant. The amount of these surfactants to be added in the color ink is not particularly limited, but in order to obtain a desired penetrability and to obtain an appropriate ink viscosity, it is in the range of 0.01 to 10% by mass of the total amount of ink. It is preferable to do. More preferably, it is made into the range of 0.1-10 mass%.

  Next, the black ink constituting the ink set for ink jet recording according to the present embodiment will be described.

  The black ink used in the present embodiment includes a color material and a liquid medium, and reacts with the color ink by contact with the color ink having the above-described configuration. Specifically, it is preferable to use a colorant that reacts with the polyvalent metal ions resulting from the polyvalent metal salt in the color ink. The “reaction” referred to here has the same meaning as in the first embodiment. Examples of the color material used for the black ink include the black color material that can be used for the colored ink of the first embodiment. These color materials may be used alone or in combination of two or more. Moreover, it is preferable that the addition amount of these coloring materials is in the range of 0.1 to 20% by mass with respect to the total amount of ink.

  In the present embodiment, it is more preferable to add a nonionic surfactant to the black ink. That is, in this way, it becomes possible to further suppress bleeding between the black ink and the color ink, and by adding a nonionic surfactant, as described below, the black ink There is also an effect that the decrease in the density of the black ink at the boundary between the color ink and the color ink, that is, the so-called “white haze” can be effectively suppressed.

  As described above, the color ink used in the ink set for ink jet recording according to the present embodiment preferably contains a surfactant for the purpose of improving the characteristics as the ink for ink jet recording. In many cases, the surface tension is high and the surface tension is low. When such a color ink having a low surface tension and a black ink having a high surface tension as used in this embodiment are adjacent to each other, a region with little color material is generated at the adjacent interface of the black ink. A phenomenon called “moy” may occur. Therefore, the above-mentioned “white haze” phenomenon can be suppressed by adding a nonionic surfactant to the black ink and reducing the surface tension.

  In the present embodiment, the content of the nonionic surfactant contained in the black ink is not particularly limited as long as bleeding and white haze can be suppressed, but the improvement of bleeding suppression between the black ink and the color ink is improved. In order to effectively suppress the occurrence of white haze, and to maintain good ink ejection properties and print quality, it is preferable to be in the range of 0.1 to 0.5 mass% of the total amount of ink, Especially preferably, it is set as the range of 0.2-0.4 mass%.

  Nonionic surfactants used at this time include, for example, higher alcohol ethylene oxide adducts, alkylphenol ethylene oxide adducts, aliphatic ethylene oxide adducts, polyhydric alcohol fatty acid ester ethylene oxide adducts, and aliphatic amide ethylenes. Examples thereof include oxide adducts, higher alkylamine ethylene oxide adducts, polypropylene glycol ethylene oxide adducts, fatty acid esters of polyhydric alcohols, and nonionic surfactants of fatty acid amides of alkanolamines. Any of these is preferably used, but more preferably nonions such as ethylene oxide adduct of higher alcohol, ethylene oxide adduct of alkylphenol, ethylene oxide-propylene oxide copolymer, ethylene oxide adduct of acetylene glycol, etc. A surfactant is used. Further, the ethylene oxide adduct having an addition mole number in the range of 4 to 20 is particularly preferable.

  Next, as the liquid medium used for the black ink and the color ink constituting the ink set for ink jet recording according to the present embodiment, the liquid composition used in the first embodiment and the liquid used for the color ink used therewith. Water-soluble organic solvents, additives, addition amounts, physical property values and the like detailed as the medium can be used.

  Next, an ink jet recording method according to the present embodiment and an ink jet recording apparatus according to the present embodiment capable of realizing the same will be described.

  In the inkjet recording method according to the present embodiment, first, (i) energy for causing the ink to be ejected is applied to the black ink included in the ink set according to the present embodiment, and the black ink is directed toward the recording medium. (Ii) applying energy to the color ink included in the ink set according to the present embodiment, and directing the color ink toward the recording medium. And a step of applying the ink onto a recording medium. As an ink jet recording method suitable for this case, there is a method in which thermal energy is applied to the ink and the ink is ejected.

  The recording medium used at this time is not particularly limited. However, in the present invention, in particular, when an image is formed on a so-called plain paper such as copy paper or bond paper that has been conventionally used by using the ink set according to the present embodiment, the bleed reduction effect is achieved. Is preferable because it appears prominently. Of course, the ink set for ink jet recording according to the present embodiment can be suitably used, for example, a coated paper specially prepared for ink jet recording and a transparent film for OHP. Can also be suitably used.

  In the ink jet recording method according to the present embodiment, the steps (i) and (ii) are performed so that a contact state between the black ink and the color ink is formed on the recording medium. Features. As a specific mode of applying the black ink and the color ink onto the recording medium as described above, there is a method of applying the black ink and the color ink so as to contact each other at the boundary.

  As another embodiment, a method of applying the black ink (1) and the color ink (2) so as to overlap each other on the recording medium and applying the color ink to the recording medium prior to the black ink (hereinafter, referred to as a black ink) Called the underlaying method). By performing the underlaying method, the bleed between the black ink and the color ink can be further improved, and the above-described “white haze” can be reduced. In the above underlaying method, the time from the time when the color ink is attached to the recording medium to the time when the black ink is attached is not particularly limited, but the above-described embodiment is more effective. In order to achieve this, it is preferable to set it within several seconds, particularly preferably within one second. In addition, there is a mode in which after the black ink is applied, the color ink is applied (overstrike), or the color ink and the black ink are mixed immediately after ejection as shown in FIG.

  In the underlaying method, the ratio of the applied amount per unit area of the recording medium between the black ink (1) and the color ink (2) in the image forming region may be 1: 1. (1): Color ink (2) = 10: 1 to 10:10 may be used. In this way, white haze in the obtained image is reduced, and uniformity is achieved particularly in a solid image. Incidentally, the adjustment of the ratio of the application amount of black ink and color ink per unit area on the recording medium in the image forming region is specifically, for example, when the application of the black ink and the color ink is performed by an ink jet recording method. In addition, the number of pixels of the color ink deposited on the recording medium is controlled to be in the range of 10 to 100% of the number of pixels of the black ink deposited on the recording medium. Control to reduce the discharge amount of black ink, or a combination of these methods, the number of pixels of color ink to be deposited on the recording medium A method of controlling so that the number of pixels is in a range of 10 to 100% and making the color ink discharge amount smaller than the black ink discharge amount, etc. And the like.

  In this embodiment, an ink jet recording method is used as a method for adhering the black ink and the color ink constituting the ink set for ink jet recording according to this embodiment on a recording medium. Various ink jet methods (for example, an ink jet recording method using mechanical energy generated by deformation of a piezoelectric element) can be used. However, when an ink jet recording method using thermal energy is used, the invention is particularly remarkable. Since an effect is acquired, it is preferable.

  That is, as described above, when a color ink containing a polyvalent metal salt is used for the purpose of improving suppression of mixed color bleeding (bleed) between the black ink and the color ink, thermal energy is used for discharging the color ink. The occurrence of kogation that occurs when an image is formed using an ink jet recording method that uses the ink, and the deterioration of the image quality caused by that occurs between the specific black ink (1) and the color ink (2) according to this embodiment. It is effectively suppressed by an ink jet recording method using an ink set composed of a combination. Furthermore, in the conventional method, when a color ink having a polyvalent metal salt for the purpose of suppressing bleed is repeatedly ejected from the recording head, it is formed on a heater (heating element substrate) that imparts thermal energy. The outermost protective layer made of metal and / or metal oxide, such as tantalum or tantalum oxide, is dissolved, which may cause the heater to be disconnected and make it impossible to discharge, In some cases, sticking occurs and affects the quality of the formed image. However, such a problem is effectively prevented. The ink jet recording apparatus using thermal energy is as described in detail in the description of the first embodiment.

  When forming a color image by the ink jet recording method according to the present embodiment, for example, a recording apparatus in which four recording heads shown in FIG. 3 are arranged on a carriage is used. FIG. 12 shows an example. Reference numerals 141, 142, 143, and 144 denote recording heads for ejecting yellow ink (Y), magenta ink (M), cyan ink (C), and black ink (Bk), respectively. The head is disposed in the recording apparatus described above, and, for example, ejects ink of each color according to a recording signal for ejecting ink of each color while moving the carriage in the direction of the arrow.

  FIG. 12 shows an example in which four recording heads are used. However, the present invention is not limited to this. As shown in FIG. 13, black ink 154, cyan ink 153, and magenta ink are used with one recording head. It is also preferable when the liquid flow paths of 152 and yellow ink 151 are separated. As a specific configuration example of the arrangement of the ink jet recording head preferably used in the present embodiment, there are two types as shown in FIGS. 14 and 15, reference numerals 161 to 164 and 171 to 174 denote recording heads for discharging various inks of yellow, magenta, cyan, and black, respectively. The recording heads are arranged on the carriage in the same manner as shown in FIG. 12 (depending on the configuration example). Each recording head is disposed in the ink jet recording apparatus as described above, and ejects various inks according to a recording signal. Each recording head is moved in the direction of arrow (1) by the carriage, and the recording medium is moved in the direction of arrow (2) by a paper feed roller or the like.

  First, in the configuration example shown in FIG. 14, recording heads for Bk (164), C (163), M (162), and Y (161) are arranged in parallel on the carriage. In the second configuration example shown in FIG. 15, the recording head for black ink (174) and this recording head are arranged in parallel and in series with each other C (173), M (172), Y (171) recording head. In FIG. 14, the present invention may be applied to a so-called line printer in which the carriage is fixed and the recording medium is moved by a paper feed roller or the like in the direction of arrow (2).

EXAMPLES Next, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited by the following Example. In the text, “parts” and “%” are based on mass unless otherwise specified.
[Example and Comparative Example of First Embodiment]
(Examples 1-36 and Comparative Examples 1-12)
The components listed below were used for each liquid composition and colored ink. As a production method, for the liquid composition and the colored ink using a dye as a coloring material, after dissolving the following components, a microfilter (Fuji Photo Film Co., Ltd.) having a pore size of 0.2 μm is further used. Then, pressure filtration was performed to prepare colored inks using the respective liquid compositions and dyes as coloring materials. In the case of a colored ink using a pigment as a color material, first, after preparing a pigment dispersion by each method, the obtained dispersion is mixed with a liquid medium or the like, and then a microfilter having a pore size of 3 μm (Fuji Photo Film). And colored ink using each pigment as a color material.

Liquid compositions 1 to 4 were prepared with the following components. The liquid composition 4 corresponds to a comparative example.
<Liquid composition 1>
・ Diethylene glycol
20 parts acetyleneol EH (manufactured by Kawaken Fine Chemicals) 2 parts magnesium nitrate hexahydrate 2 parts D-glucose
5 parts water
71 parts <Liquid composition 2>
・ 10 parts of triethylene glycol monobutyl ether ・ Glycerin
10 parts Magnesium nitrate hexahydrate 3 parts D-mannose
5 parts water
72 parts <Liquid composition 3>
・ 10 parts of triethylene glycol monobutyl ether ・ Glycerin
10 parts calcium glycerophosphate
1 part D-xylose
5 parts water
74 parts <Liquid composition 4>
・ 10 parts of triethylene glycol monobutyl ether ・ Glycerin
10 parts, magnesium nitrate, hexahydrate, 3 parts, water
77 parts <Black Ink 1>
(Preparation of Pigment Dispersion 1) 300 g of commercially available acidic carbon black “MA77” (pH 3; manufactured by Mitsubishi Chemical Corporation) was mixed well with 1000 ml of water, and then sodium hypochlorite (effective chlorine concentration 12%). 450g was dripped and it stirred at 100-105 degreeC for 10 hours. The obtained slurry was Toyo Filter Paper No. 2 (manufactured by Advantis) and sufficiently washed the pigment particles with water. This pigment wet cake was re-dispersed in 3,000 ml of water, and desalted with a reverse osmosis membrane to an electric conductivity of 0.2 μs. Further, this pigment dispersion (pH = 8 to 10) was concentrated to a pigment concentration of 10% by mass. By the above method, a —COONa group was introduced on the surface of the carbon black to obtain a pigment dispersion 1 having such a self-dispersing carbon black.
(Preparation of ink)
The following components including the pigment dispersion 1 obtained above were mixed, and further filtered under pressure using a microfilter having a pore size of 3 μm (manufactured by Fuji Photo Film Co., Ltd.) to prepare a black ink 1. .
-Pigment dispersion 1
40 parts glycerin
8 parts, trimethylolpropane
5 parts isopropyl alcohol
4 parts, water
43 parts <Black Ink 2>
(Preparation of pigment dispersion 2)
・ Styrene-acrylic acid-butyl acrylate copolymer (acid value 116, average molecular weight 3,700) 5 parts ・ Triethanolamine
0.5 parts diethylene glycol
5 parts water
69.5 parts The above components are mixed and heated to 70 ° C in a water bath to completely dissolve the resin components. To this solution, 15 parts of carbon black “MA-100” (pH 3.5; manufactured by Mitsubishi Chemical Corporation) and 5 parts of 2-propanol were added, premixed for 30 minutes, and then subjected to a dispersion treatment under the following conditions. It was.
・ Disperser: Sand grinder (Igarashi Machine)
・ Crushing media: 1 mm diameter of zirconium beads ・ Filling rate of grinding media: 50% (volume)
-Grinding time: 3 hours Further, a centrifugal treatment (12,000 rpm, 20 minutes) was performed to remove coarse particles to obtain a pigment dispersion 2 containing carbon black.
(Preparation of ink)
The following components including the pigment dispersion 2 obtained above were mixed, and further filtered under pressure using a microfilter having a pore size of 3 μm (manufactured by Fuji Photo Film Co., Ltd.) to prepare black ink 2.
-Pigment dispersion 2
20 parts, trimethylolpropane
5 parts diethylene glycol
10 parts 2-pyrrolidone
5 parts, acetylenol EH (manufactured by Kawaken Fine Chemicals) 0.2 part, water
59.8 parts <Black Ink 3>
The following components containing the exemplified compound 1 as a colorant were mixed, and further filtered under pressure using a microfilter (manufactured by Fuji Photo Film Co., Ltd.) having a pore size of 0.2 μm to prepare a black ink 3.
-Exemplified Compound 1 (wherein M is NH4 +)
2 parts diethylene glycol
10 parts 2-pyrrolidone
5 parts 2-propanol
5 parts sodium hydroxide
0.1 part water
77.9 parts <yellow ink 1>
(Preparation of pigment dispersion 3)
・ Styrene-acrylic acid copolymer (acid value 200,
(Average molecular weight 7,000)
5.5 parts monoethanolamine
1.0 part, ion-exchanged water
67.5 parts diethylene glycol
5.0 parts of the above components were mixed and heated to 70 ° C. in a water bath to completely dissolve the resin component. To this solution, C.I. I. Pigment Yellow
20 parts of 93 and 1.0 part of isopropyl alcohol were added, premixed for 30 minutes, and then subjected to a dispersion treatment under the following conditions.
・ Disperser: Sand grinder ・ Crushing media: Glass beads 1 mm diameter ・ Filling rate of grinding media: 50% (volume)
-Grinding time: 3 hours Further, a centrifugal separation process (12,000 rpm, 20 minutes) was performed to remove coarse particles to obtain a pigment dispersion 3.
(Preparation of ink)
The following components including the pigment dispersion 3 obtained above were mixed, and further filtered under pressure using a microfilter (Fuji Photo Film Co., Ltd.) having a pore size of 3 μm to prepare yellow ink 1.
-Pigment dispersion 3
20 parts glycerin
15 parts diethylene glycol
10 parts Acetylenol EH (manufactured by Kawaken Fine Chemicals) 0.3 parts Water
54.7 parts <Yellow Ink 2>
Using the following components containing the exemplified compound 2 as a coloring material, these were dissolved, and then filtered under pressure using a microfilter (manufactured by Fuji Photo Film Co., Ltd.) having a pore size of 0.2 μm. Prepared.
-Exemplified compound 2 (wherein M is NH4 +)
3 parts glycerin 7 parts diethylene glycol
5 parts urea
5 parts ethanol
2 parts, water
78 parts <Magenta ink 1>
(Preparation of pigment dispersion 4)
・ Styrene-acrylic acid copolymer (acid value 200,
(Average molecular weight 7,000)
5.5 parts ・ 1.0 parts of monoethanolamine ・ Ion-exchanged water
67.5 parts diethylene glycol
5.0 parts The above components were mixed and heated to 70 ° C. in a water bath to completely dissolve the resin component. In this solution, C.I. I. Pigment Red
After adding 20 parts of 122 and 1.0 part of isopropyl alcohol and performing premixing for 30 minutes, dispersion treatment was performed under the following conditions.
・ Disperser: Sand grinder ・ Crushing media: Glass beads 1 mm diameter ・ Filling rate of grinding media: 50% (volume)
-Grinding time: 3 hours Further, a centrifugal treatment (12,000 rpm, 20 minutes) was performed to remove coarse particles to obtain a pigment dispersion 4.
(Preparation of ink)
The following components including the pigment dispersion 4 obtained above were mixed, and further filtered under pressure using a microfilter having a pore size of 3 μm (manufactured by Fuji Photo Film Co., Ltd.) to prepare magenta ink 1.
・ Pigment dispersion 4
20 parts glycerin
15 parts diethylene glycol
10 parts Acetylenol EH (manufactured by Kawaken Fine Chemicals) 0.3 parts Water
54.7 parts <Magenta ink 2>
The following components containing the exemplified compound 3 as a coloring material were used, dissolved, and then filtered under pressure using a microfilter (manufactured by Fuji Photo Film Co., Ltd.) having a pore size of 0.2 μm to obtain magenta ink 2. Prepared.
-Exemplified compound 3 (wherein M is NH4 +)
3 parts glycerin
7 parts diethylene glycol 5 parts urea
5 parts ethanol
2 parts, water
78 parts <Cyan ink 1>
(Preparation of pigment dispersion 5)
・ Styrene-acrylic acid copolymer (acid value 200,
(Average molecular weight 7,000)
5.5 parts monoethanolamine
1.0 part ・ Ion-exchange water 67.5 parts ・ Diethylene glycol
5.0 parts The above components were mixed and heated to 70 ° C. in a water bath to completely dissolve the resin component. Furthermore, C.I. I. Pigment Blue
20 parts of 15: 3 and 1.0 part of isopropyl alcohol were added, premixed for 30 minutes, and then subjected to a dispersion treatment under the following conditions.
・ Disperser: Sand grinder ・ Crushing media: Glass beads 1 mm diameter ・ Filling rate of grinding media: 50% (volume)
-Crushing time: 3 hours Further, a centrifugal treatment (12,000 rpm, 20 minutes) was performed to remove coarse particles, whereby a pigment dispersion 5 was obtained.
(Preparation of ink)
The following components including the pigment dispersion 5 obtained above were mixed, and further filtered under pressure using a microfilter having a pore size of 3 μm (manufactured by Fuji Photo Film Co., Ltd.) to prepare cyan ink 1.
・ Pigment dispersion 5
20 parts glycerin
15 parts diethylene glycol
10 parts Acetylenol EH (manufactured by Kawaken Fine Chemicals) 0.3 parts Water
54.7 parts <Cyan ink 2>
The following components containing the exemplified compound 4 as a coloring material were used, dissolved, and then filtered under pressure using a microfilter (manufactured by Fuji Photo Film Co., Ltd.) having a pore size of 0.2 μm. Prepared.
-Exemplified Compound 4 (wherein M is NH4 +)
3 parts glycerin
7 parts diethylene glycol
5 parts urea
5 parts ethanol
2 parts, water
78 parts (evaluation and evaluation criteria)
<Evaluation Test> The evaluation test is shown below.
[Evaluation 1]
The liquid compositions 1 to 3 having the configuration of the present invention obtained as described above and the liquid composition 4 of the comparative example were applied to the ink by applying thermal energy corresponding to the recording signal to the liquid composition. Using an inkjet recording apparatus having an on-demand type multi-recording head (BC-02 (manufactured by Canon Inc.): the outermost protective layer on the heater is made of tantalum and an oxide of tantalum) The composition was discharged and evaluated. The ejection conditions of the liquid composition of the inkjet recording apparatus are as follows: pulse width 1.1 μs (On) +3.0 μs (Off) +3.2 μs (On), driving frequency 6,250 Hz, Vth (critical voltage for ejection) Was actually measured, and the liquid composition was discharged by applying Vop (driving voltage) corresponding to γ value = 1.6. Then, the ejection durability in the inkjet recording head and the state of occurrence of kogation on the heater when inkjet recording was performed under these conditions were evaluated by the following methods and criteria. The results are shown in Table 1.

1. Discharge durability Continuous discharge was performed under the above-mentioned apparatus and driving conditions, and droplets discharged from the recording head every 1 × 10 ⁶ shots were collected in a container and weighed with an electronic balance. The average discharge droplet amount at 1 × 10 ⁶ shots was calculated from the increase amount of the container. In addition, continuous discharge was performed up to 1 × 10 ⁸ shots and evaluated according to the following criteria.

A: The average discharge droplet amount between 9.9 × 10 ⁷ to 1 × 10 ⁸ shots is 90% or more compared with the average discharge droplet amount after 0 to 1 × 10 ⁶ shots.

B: The average discharge droplet amount between 9.9 × 10 ⁷ to 1 × 10 ⁸ shots is less than 90% to 70% compared to the average discharge droplet amount after 0 to 1 × 10 ⁶ shots.

C: The average discharge droplet amount between 9.9 × 10 ^{7 and} 1 × 10 ⁸ shots is less than 70% compared with the average discharge droplet amount after 0 to 1 × 10 ⁶ shots.

  D: Discharge was impossible on the way.

［評価２］
上記で得られた各着色インクと各液体組成物１〜３とを表２に示した組合わせを用いて記録紙に記録を行った。使用したインクジェット記録装置としては、図４に示したと同様の構成の記録装置を用い、図７に示した５つの記録ヘッドの内の２つの記録ヘッドを用いて画像を形成した。この際、液体組成物を先打ちして先ず記録紙上に付着させ、その後、着色インクを付着させる構成とした。記録紙上への液体組成物を付与する位置が、記録紙上へ着色インクが付与される位置と正確に重なるように調整した。尚、ここで用いた記録ヘッドは、３６０ｄｐｉの記録密度を有し、駆動周波数は５ｋＨｚとした。又、１ドット当たりの吐出体積は着色インクは８０ｐｌ／ｄｏｔ、液体組成物は４０ｐｌ／ｄｏｔのヘッドを使用した。又、記録紙はＰＢ用紙（キヤノン株式会社製：複写機用とインクジェット記録用の共用紙）と、ＸＥＲＯＸ ４０２４紙（ゼロックス株式会社製）を使用した。

[Evaluation 2]
Each colored ink obtained above and each of the liquid compositions 1 to 3 were recorded on a recording paper using the combinations shown in Table 2. As the ink jet recording apparatus used, a recording apparatus having the same configuration as shown in FIG. 4 was used, and an image was formed using two recording heads out of the five recording heads shown in FIG. At this time, the liquid composition was pre-applied and first deposited on the recording paper, and then the colored ink was adhered. The position where the liquid composition was applied onto the recording paper was adjusted so as to be exactly overlapped with the position where the colored ink was applied onto the recording paper. The recording head used here has a recording density of 360 dpi and a driving frequency of 5 kHz. The discharge volume per dot was 80 pl / dot for colored ink and 40 pl / dot for the liquid composition. Further, PB paper (manufactured by Canon Inc .: copier and ink jet recording paper) and XEROX 4024 paper (manufactured by Xerox Co., Ltd.) were used as the recording paper.

2. Water resistance of image Using the combinations shown in Table 2 for each of the colored inks and the liquid composition, printing is performed by the above method. After the print is left for 1 hour, the print density is set to Macbeth RD915 (trade name: Macbeth Measured at a manufacturer. Thereafter, the printed matter was immersed in a container filled with tap water for 3 minutes, and then left standing, dried, and again measured for the print density, and the residual ratio of the printed matter concentration was determined to evaluate the water resistance. It is practically preferable that the residual ratio of the print density is 95% or more. The evaluation results are shown in Table 2.

Residual rate of print density = (print density after immersion in water / print density before immersion in water) × 100
A: The residual ratio of the printed matter density is 95% or more.

  B: Residual rate of printed matter density is 85% or more and less than 95%.

  C: Residual rate of printed matter density is less than 85%.

3. Image print quality (bleed)
Alphanumeric characters (12 points) were printed in the same manner and left for 1 hour, and then visually evaluated based on the sharpness of the characters and the degree of the occurrence of whiskers on the edges of the characters. The evaluation results are shown in Table 2.

  A: The letters are sharp and there is no bearded blur.

  B: Characters are not sharp and blurring occurs slightly.

  C: Characters are not sharp and have a lot of bleeding.

４．ブリード（異色間の混色滲み）
上記の普通紙２紙に、表３に示した組合わせの液体組成物と着色インクのセットとから成る各インクセットを用い、先ず液体組成物でベタ部を印字し、その直後液体組成物のベタ部の範囲上をブラックインクでベタ部を印字し、その直後に、ブラックインクのベタ部と隣接するように液体組成物のベタ部の範囲上をイエロー、又はマゼンタ、又はシアンインクで各色のインクのベタ部を印字した。以上のようにして得られたベタ印字の境界部分を目視にて観察して、各着色インクとの間のブリーディングの評価を行った。評価基準は以下の通りとした。

4). Bleed (mixed color bleeding between different colors)
On each of the two plain papers, each ink set comprising the combination of the liquid composition shown in Table 3 and a set of colored inks was used. First, a solid part was printed with the liquid composition, and immediately thereafter the liquid composition was printed. Immediately after that, the solid portion is printed with black ink on the solid portion range, and immediately after that, each color of each color is printed with yellow, magenta, or cyan ink on the solid portion range of the liquid composition so as to be adjacent to the solid portion of the black ink. The solid part of the ink was printed. The border portion of the solid print obtained as described above was visually observed to evaluate bleeding with each colored ink. The evaluation criteria were as follows.

  A: Bleeding is not recognized at all boundaries.

  B: Slight bleeding is observed, but not so much.

  C: Bleeding is severe at almost all boundaries.

  The evaluation results are shown in Table 3.

［第２の実施形態の実施例及び比較例］
（実施例３７〜３９及び比較例１３）
ブラックインク及びイエロー、マゼンタ、シアンのカラーインクを組み合わせて実施例３７〜３９及び比較例１３のインクセットを作製した。各々のインクは、下記に挙げる成分を用いて以下の方法で作製した。各インクセットを構成するブラックインクについては、前記した実施の形態１の際に説明したと同様の顔料分散液１及び２を用い、下記に挙げた各成分と混合した後、ポアサイズが３μｍのミクロフィルター（富士写真フィルム（株）製）を用いて加圧濾過して作製した。

[Example and Comparative Example of Second Embodiment]
(Examples 37 to 39 and Comparative Example 13)
Ink sets of Examples 37 to 39 and Comparative Example 13 were prepared by combining black ink and yellow, magenta, and cyan color inks. Each ink was prepared by the following method using the components listed below. For the black ink constituting each ink set, the same pigment dispersions 1 and 2 as described in the first embodiment were used, and after mixing with each of the components listed below, the micro ink having a pore size of 3 μm was used. It was prepared by pressure filtration using a filter (Fuji Photo Film Co., Ltd.).

For the color inks constituting each ink set, the production method is as follows. For the color ink using a liquid composition and a dye as a coloring material, the pore size is 0.2 μm after mixing with each of the components listed below. Each color ink was prepared by pressure filtration using a microfilter (Fuji Photo Film Co., Ltd.). Table 4 shows main compositions of the ink sets of Examples 37 to 39 and Comparative Example 13.
<Ink set of Example 37>
(Black ink composition)
-Pigment dispersion 1
40 parts glycerin
8 parts, trimethylolpropane
5 parts isopropyl alcohol
4 parts, water
43 parts (yellow ink composition)
・ C. I. Acid Yellow 23 2.5 parts glycerin
5 parts diethylene glycol
5 parts, acetylenol EH
(Made by Kawaken Fine Chemicals)
1 part magnesium acetate tetrahydrate 2 parts D-mannose
5 parts water
79.5 parts (magenta ink composition)
・ C. I acid red 289 2 parts glycerin
8 parts diethylene glycol
5 parts, acetylenol EH
(Made by Kawaken Fine Chemicals)
1 part magnesium nitrate hexahydrate 1 part D-glucose
5 parts water
78 parts (cyan ink composition)
・ C. I Acid Blue 9
2 parts glycerin
8 parts diethylene glycol
5 parts, acetylenol EH
(Made by Kawaken Fine Chemicals)
1 part magnesium nitrate hexahydrate 1 part D-mannose
5 parts water
78 parts <Ink set of Example 38>
(Black ink composition)
-Pigment dispersion 1
40 parts glycerin
5 parts diethylene glycol
5 parts 2-pyrrolidone
5 parts, acetylenol EH
(Kawaken Fine Chemical) 0.3 parts water
44.7 parts (yellow ink composition)
・ C. I. Acid Yellow 23 2.5 parts glycerin
5 parts diethylene glycol
5 parts, trimethylolpropane
5 parts, acetylenol EH
(Made by Kawaken Fine Chemicals)
1 part magnesium gluconate
1 part D-Mannose
5 parts water
75.5 parts (magenta ink composition)
・ C. I acid red 289 2 parts glycerin
8 parts diethylene glycol
5 parts thiodiglycol
5 parts, acetylenol EH
(Made by Kawaken Fine Chemicals)
1 part magnesium sulfate heptahydrate 2 parts D-mannose
5 parts water
73 parts (cyan ink composition)
・ C. I Acid Blue 9
2 parts, ethylene glycol
8 parts diethylene glycol
5 parts, trimethylolpropane
5 parts, acetylenol EH
(Made by Kawaken Fine Chemicals)
1 part calcium nitrate tetrahydrate
1 part D-Mannose
5 parts water
73 parts <Ink set of Example 39>
(Black ink composition)
-Pigment dispersion 2
20 parts, trimethylolpropane
5 parts diethylene glycol 10 parts 2-pyrrolidone
5 parts, acetylenol EH
(Manufactured by Kawaken Fine Chemicals) 0.2 parts water
59.8 parts (yellow ink composition)
・ C. I. Acid Yellow 23 2.5 parts glycerin
5 parts diethylene glycol
5 parts trimethylolpropane 5 parts acetylenol EH
(Made by Kawaken Fine Chemicals)
1 part calcium glycerophosphate
1 part D-Mannose
5 parts water
74.5 parts (magenta ink composition)
・ C. I acid red 289 2 parts glycerin
8 parts diethylene glycol
5 parts thiodiglycol
5 parts, acetylenol EH
(Made by Kawaken Fine Chemicals)
1 part magnesium sulfate heptahydrate 1 part D-glucose
5 parts water
73 parts (cyan ink composition)
・ C. I Acid Blue 9
2 parts, ethylene glycol
8 parts diethylene glycol
5 parts, trimethylolpropane
5 parts, acetylenol EH
(Made by Kawaken Fine Chemicals)
1 part magnesium nitrate hexahydrate 1 part D-xylose
5 parts water
73 parts <Ink set of Comparative Example 13>
(Black ink composition)
・ 40 parts of the above pigment dispersion 1 ・ Glycerin
8 parts, trimethylolpropane
5 parts isopropyl alcohol
4 parts, water
43 parts (yellow ink composition)
・ C. I. Acid Yellow 23 2.5 parts glycerin
5 parts diethylene glycol
5 parts, acetylenol EH
(Made by Kawaken Fine Chemicals)
1 part water
86.5 parts (magenta ink composition)
・ C. I acid red 289 2 parts glycerin
8 parts diethylene glycol
5 parts, acetylenol EH
(Made by Kawaken Fine Chemicals)
1 part water
84 parts (cyan ink composition)
・ C. I Acid Blue 9
2 parts glycerin
8 parts diethylene glycol
5 parts, acetylenol EH
(Made by Kawaken Fine Chemicals)
1 part water
84 parts

Ｍｇ＝マグネシウム、Ｃａ＝カルシウム
（評価及び評価基準）
＜評価試験＞評価試験について以下に示す。
［評価１］
上記の実施例３７〜３９及び比較例１３のインクセットのインクと、記録信号に応じた熱エネルギーをインクに付与することによりインクを吐出させるオンデマンド型マルチ記録ヘッド（ＢＣ−０２（キヤノン（株）製）：ヒーター上の最表面保護層はタンタル及びタンタルの酸化物より成る）を有するインクジェット記録装置を用い、下記の条件でインクを吐出させて評価した。上記インクジェット記録装置のインクの吐出条件は、パルス幅１．１μｓ（Ｏｎ）＋３．０μｓ（Ｏｆｆ）＋３．２μｓ（Ｏｎ）、駆動周波数６，２５０Ｈｚで、Ｖth（吐出するぎりぎりの臨界電圧）を実測し、γ値＝１．６に相当するＶop（駆動電圧）を掛けてインクを吐出させた。そして、この条件でインクジェット記録を行った場合のインクジェット記録ヘッドにおける吐出耐久性及びヒータへのコゲ付着量を下記の方法及び基準で評価した。その結果を表５に示した。
（１）吐出耐久性
前記装置と駆動条件で連続吐出を行い、１×１０⁶発おきに記録ヘッドから吐出される液滴を容器に収集して、電子天秤で秤量した。容器の増加量より１×１０⁶発における平均の吐出液滴量を算出した。尚、連続吐出は１×１０⁸発まで行い、下記の基準で評価した。

Mg = magnesium, Ca = calcium (evaluation and evaluation criteria)
<Evaluation Test> The evaluation test is shown below.
[Evaluation 1]
On-demand type multi-recording head (BC-02 (Canon Corporation) that ejects ink by applying the ink of the ink sets of Examples 37 to 39 and Comparative Example 13 and thermal energy corresponding to the recording signal to the ink. )): An ink jet recording apparatus having an outermost protective layer on the heater made of tantalum and an oxide of tantalum) was used for evaluation under the following conditions. The ink ejection conditions of the inkjet recording apparatus were measured as follows: Vth (critical voltage for ejection) at a pulse width of 1.1 μs (On) +3.0 μs (Off) +3.2 μs (On), a driving frequency of 6,250 Hz. Ink was ejected by applying Vop (driving voltage) corresponding to γ value = 1.6. Then, the ejection durability in the ink jet recording head and the amount of kogation on the heater when ink jet recording was performed under these conditions were evaluated by the following methods and standards. The results are shown in Table 5.
(1) Discharge durability Continuous discharge was performed under the above-mentioned apparatus and driving conditions, and droplets discharged from the recording head every 1 × 10 ⁶ shots were collected in a container and weighed with an electronic balance. The average discharge droplet amount at 1 × 10 ⁶ shots was calculated from the increase amount of the container. In addition, continuous discharge was performed up to 1 × 10 ⁸ shots and evaluated according to the following criteria.

A: The average discharge droplet amount between 9.9 × 10 ⁷ to 1 × 10 ⁸ shots is 90% or more compared with the average discharge droplet amount after 0 to 1 × 10 ⁶ shots.

B: The average discharge droplet amount between 9.9 × 10 ⁷ to 1 × 10 ⁸ shots is less than 90% to 70% compared to the average discharge droplet amount after 0 to 1 × 10 ⁶ shots.

C: The average discharge droplet amount between 9.9 × 10 ^{7 and} 1 × 10 ⁸ shots is less than 70% compared with the average discharge droplet amount after 0 to 1 × 10 ⁶ shots.

D: Discharge was impossible on the way.
(2) Amount of kogation The recording head, which has been evaluated for the ejection durability of the head, was disassembled, and the surface of the nozzle heater used for the evaluation of the ejection durability was visually observed with an optical microscope (400 times magnification). The adhesion amount was evaluated according to the following criteria.

  A: Almost no adhesion of kogation is observed.

  B: Slight adhesion of koge is observed.

  C: A lot of kogation is observed.

  D: Very much adhesion of koge is seen.

［評価２］
（実施例３７〜４２、及び比較例１３及び１４）
上記で得られた本発明の実施例３７〜３９、及び比較例１３のインクセットの各インクをそれぞれ搭載した、記録信号に応じた熱エネルギーをインクに付与することによりインクを吐出させるオンデマンド型マルチ記録ヘッドを有するインクジェット記録装置であるカラーインクジェットプリンター（ＢＪＣ−７００Ｊ：キヤノン（株）製）を用いて画像を形成し、以下の（３）及び（４）についての評価を行った。

[Evaluation 2]
(Examples 37 to 42 and Comparative Examples 13 and 14)
An on-demand type in which each of the inks of the ink sets of Examples 37 to 39 of the present invention obtained above and Comparative Example 13 is mounted, and the ink is ejected by applying thermal energy corresponding to the recording signal to the ink. Images were formed using a color inkjet printer (BJC-700J: manufactured by Canon Inc.), which is an inkjet recording apparatus having a multi-recording head, and the following (3) and (4) were evaluated.

Furthermore, using each of the ink sets of Examples 37 to 39 and Comparative Example 13 of the present invention, black ink and color ink were applied to the same position on the recording medium, and color ink was applied to the recording medium. An image was created so that the application could be performed prior to the black ink (underlay). The ink jet recording method based on the undercoating method using the ink set of Examples 37 to 39 is referred to as Examples 40 to 42, and the ink jet recording method based on the undercoating method using the ink set of Comparative Example 13 is referred to as Comparative Example 14. Was evaluated. In the underlaying method, the ratio of the black ink and the color ink applied per unit area of the recording medium is black ink: color ink = 10: 2.5, and the ratio of the applied amount of the color ink is Yellow ink: magenta ink: cyan ink = 1: 1: 1.

As the paper for the evaluation test, Canon copy paper (trade name: PB PAPER) and Xerox copy paper (trade name: 4024 PAPER) were used. The obtained results are shown in Table 6.
(3) Bleeding between black ink and color ink Yellow, magenta, or cyan ink is printed on the above two plain papers with the black ink in each ink set and immediately adjacent to it. To print the solid portion of each color ink. The boundary portion of the obtained solid print was visually observed to evaluate bleeding between the black ink and the color ink. The evaluation criteria were as follows.

  A: Bleeding is not recognized at all boundaries.

  B: Some bleeding is observed.

C: Bleeding is severe at almost all boundaries.
(4) Density of black ink portion at adjacent boundary portion between black ink and color ink (generation of white haze)
The solid part is printed with black ink on each of the above two plain papers with black ink, and immediately after that, the solid part is printed with yellow, magenta, or cyan ink, and the border with black ink. The occurrence of white haze in the part was visually observed and evaluated. The evaluation criteria were as follows.

  A: No decrease in the density of the black ink portion at the boundary portion was observed, and no white haze occurred.

  B: It can be seen that the density of the black ink portion at the boundary portion is reduced and white haze is generated, but there is no practical problem.

  C: The density of the black ink portion at the boundary is greatly reduced, and white haze is significantly generated.

但し、表中のＰＢ紙はキヤノン社製ＰＢ用紙、ＸＸ紙はゼロックス社製ＸＥＲＯＸ４０２４紙を表す。

However, PB paper in the table represents Canon PB paper, and XX paper represents XEROX 4024 paper from Xerox Corporation.

It is a longitudinal cross-sectional view which shows an example of the recording head of the inkjet recording device of this invention. It is a cross-sectional view showing an example of a recording head of the ink jet recording apparatus of the present invention. FIG. 2 is an external perspective view of a head in which the recording head shown in FIG. It is a schematic perspective view which shows an example of the inkjet recording device of this invention. 2 is a perspective view of an internal configuration showing an example of an ink cartridge. FIG. It is a perspective view which shows an example of a recording unit. FIG. 6 is a perspective view illustrating a recording unit in which a plurality of recording heads are arranged. It is a perspective view of another recording head used for the present invention. FIG. 3 is a diagram illustrating a first configuration diagram of a recording head. FIG. 6 is a diagram illustrating a second configuration diagram of the recording head. FIG. 10 is a diagram illustrating a third configuration diagram of the recording head. FIG. 6 is a perspective view illustrating a recording unit in which a plurality of recording heads are arranged. It is a perspective view of another recording head used for the present invention. FIG. 10 is a diagram illustrating a fourth configuration example of a recording head. It is a figure which shows the 5th structural example of a recording head. It is the schematic of the inkjet recording method concerning one Embodiment of this invention.

Explanation of symbols

13 Recording head 14 Ink groove (nozzle)
DESCRIPTION OF SYMBOLS 15 Heat generating element board | substrate 16-1 Protective layer 16-2 Outermost surface protective layer 17-1, 17-2 Electrode 18 Heat generating resistor layer 19 Heat storage layer 20 Substrate 21 Ink 22 Discharge orifice 23 Meniscus 24 Ink droplet 25 Recording medium 26 Multi groove (multi nozzle)
27 Glass plate 28 Heat generating head 40 Ink bag 42 Plug 44 Ink absorber 45 Ink cartridge 51 Paper feed unit 52 Paper feed roller 53 Paper discharge roller 61 Blade 62 Cap 63 Ink absorber 64 Discharge recovery unit 65 Recording head 66 Carriage 67 Guide shaft 68 Motor 69 Drive belt 70 Recording unit 71 Head portion 72 Atmospheric communication port 80 Ink flow path 81 Orifice plate 82 Vibration plate 83 Piezoelectric element 84 Substrate 85 Discharge port 91 Yellow ink recording head 92 Magenta ink recording head 93 Cyan ink recording head 94 Black Ink recording head 95 Liquid composition recording head 96 Carriage 101 Yellow ink flow path 102 Magenta ink flow path 103 Cyan ink flow path 104 Black ink flow path 105 Liquid Composition channel 111 Yellow ink recording head 112 Magenta ink recording head 113 Cyan ink recording head 114 Black ink recording head 115 Liquid composition recording head 121 Yellow ink recording head 122 Magenta ink recording head 123 Cyan ink recording head 124 Black ink recording head 125 Liquid composition recording head 131 Yellow ink recording head 132 Magenta ink recording head 133 Cyan ink recording head 134 Black ink recording head 135 Liquid composition recording head 141 Yellow ink recording head 142 Magenta ink recording head 143 Cyan ink recording head 144 Black ink recording Head 145 Carriage 151 Yellow ink channel 152 Magenta ink channel 153 Cyan Ink channel 154 Black ink channel 161 Yellow ink recording head 162 Magenta ink recording head 163 Cyan ink recording head 164 Black ink recording head 171 Yellow ink recording head 172 Magenta ink recording head 173 Cyan ink recording head 174 Black ink recording head 801 Liquid Composition recording head 802 Colored ink recording head 803 Recording medium 804 Liquid composition 805 Colored ink 806 Mixed state of liquid composition and colored ink

Claims (46)

  A liquid composition for ink jet recording which is used together with a colored ink and reacts when contacted with the colored ink, and is at least one selected from (a) a polyvalent metal salt and (b) a reducing sugar having 4 or more carbon atoms. A liquid composition comprising two compounds and (c) a liquid medium.   The total content of the polyvalent metal salt is 0.005 to 20% by mass with respect to the total amount of the liquid composition, and the total content of substances selected from the reducing sugars having 4 or more carbon atoms is the total amount of the liquid composition The liquid composition according to claim 1, wherein the content is 0.005 to 20% by mass relative to the mass.   The liquid composition according to claim 1 or 2, wherein the polyvalent metal salt is at least one selected from a polyvalent metal salt of nitric acid, sulfuric acid, hydrochloric acid, acetic acid, hydroxycarboxylic acid and polyol phosphate.   The polyvalent metal salts of nitric acid, sulfuric acid, hydrochloric acid, acetic acid, hydroxycarboxylic acid and polyol phosphate are magnesium nitrate, calcium nitrate, barium nitrate, iron (II) nitrate, copper (II) nitrate, zinc nitrate, magnesium sulfate , Calcium sulfate, magnesium chloride, calcium chloride, magnesium acetate, calcium acetate, barium acetate, iron (II) acetate, copper acetate (II), zinc acetate, magnesium gluconate, calcium gluconate, barium gluconate, iron gluconate ( The liquid composition according to claim 3, comprising II), copper (II) gluconate, zinc gluconate, magnesium glycerophosphate and calcium glycerophosphate.   The reducing sugar having 4 or more carbon atoms is at least one selected from D-glucose, D-mannose, D-galactose, D-fructose, D-arabinose, D-ribose, D-xylose, and D-erythrose. The liquid composition of any one of Claims 1-4. (I) A step of applying energy to the liquid composition according to any one of claims 1 to 5 and discharging the liquid composition toward a recording medium to apply the liquid composition onto the recording medium;
(Ii) A coloring ink containing a coloring material and a liquid medium and reacting with the liquid composition by contact with the liquid composition is applied with energy and discharged toward the recording medium, and the colored ink is covered. And applying the steps (i) and (ii) so as to form a contact state between the liquid composition and the colored ink on the recording medium. An inkjet recording method.   7. The ink jet recording method according to claim 6, wherein the coloring material of the colored ink is a pigment.   7. The ink jet recording method according to claim 6, wherein the coloring material of the colored ink is a dye having at least one carboxyl group.   The ink jet recording method according to claim 6, wherein the energy is thermal energy.   The ink jet recording method according to any one of claims 6 to 9, wherein the application of the liquid composition onto the recording medium is performed prior to the application of the colored ink onto the recording medium.   10. The ink jet recording method according to claim 6, wherein the liquid composition is applied onto the recording medium after the coloring ink is applied onto the recording medium.   The liquid composition is applied onto the recording medium after the coloring ink is applied onto the recording medium, and then the colored ink is further applied onto the recording medium. The inkjet recording method according to any one of the above.   The colored ink is applied onto the recording medium after the liquid composition is applied onto the recording medium, and then the liquid composition is further applied onto the recording medium. 10. The ink jet recording method according to any one of 9 above.   The liquid composition and the colored ink are mixed immediately after ejection from an ink jet recording apparatus, and then the mixture is applied onto a recording medium. Inkjet recording method.   (1) The liquid composition according to any one of claims 1 to 5, and (2) a coloring material and a liquid medium, and react with the liquid composition by contact with the liquid composition. An ink set for ink-jet recording, comprising a combination of colored inks.   A liquid composition container containing the liquid composition according to any one of claims 1 to 5 and a colored ink that reacts with the liquid composition by contact with the liquid composition. A recording unit comprising: an ink storage unit; and an ink jet recording head for applying energy to the liquid composition and the colored ink to discharge the liquid composition and the colored ink, respectively.   The recording unit according to claim 16, wherein the ink jet recording head includes a heater including an outermost surface protective layer containing a substance selected from a metal and a metal oxide.   18. The recording unit according to claim 17, wherein the outermost protective layer contains tantalum or a tantalum oxide as a material selected from a metal and a metal oxide.   A liquid composition container containing the liquid composition according to any one of claims 1 to 5, a color material and a liquid medium, and the liquid composition by contact with the liquid composition An ink cartridge comprising: an ink containing portion containing a colored ink that reacts with an object. A liquid composition container containing a liquid composition, a colored ink container containing a colored ink that reacts with the liquid composition upon contact with the liquid composition, the liquid composition, and the coloring In an ink jet recording apparatus equipped with an ink jet recording head for applying energy to ink and discharging the liquid composition and the colored ink, respectively,
An ink jet recording apparatus, wherein the liquid composition is the liquid composition according to claim 1.   The ink jet recording head includes a heater having an outermost surface protective layer containing a material selected from a metal and a metal oxide, and the ink jet recording apparatus applies a pulsed electric signal to the heater according to recording information. 21. The ink jet recording apparatus according to claim 20, further comprising means for performing the operation.   22. The ink jet recording apparatus according to claim 21, wherein the substance selected from the metal and the metal oxide includes tantalum or an oxide of tantalum. The energy (Eop) input to discharge the liquid composition has the following relationship:
1.10 ≦ Eop / Eth ≦ 1.90
(Eth is the minimum energy required to eject the liquid composition from the recording head).
The inkjet recording apparatus according to claim 20, wherein:   (1) a color ink including a color material, a liquid medium, a polyvalent metal salt, and at least one compound selected from reducing sugars having 4 or more carbon atoms; and (2) a color material and a liquid medium. An ink set for ink-jet recording comprising a combination of a black ink that reacts with the color ink upon contact with the color ink.   The total content of the polyvalent metal salt contained in the color ink is 0.005 to 20% by mass with respect to the total amount of the color ink, and the total content of substances selected from reducing sugars having 4 or more carbon atoms. 25. The ink set for inkjet recording according to claim 24, wherein the content is 0.005 to 20% by mass with respect to the total amount of the color ink.   The inkjet according to claim 24 or 25, wherein the polyvalent metal salt is at least one selected from a polyvalent metal salt of nitric acid, sulfuric acid, hydrochloric acid, acetic acid, hydroxycarboxylic acid, and polyol phosphate. Ink set for recording.   The polyvalent metal salts of nitric acid, sulfuric acid, hydrochloric acid, acetic acid, hydroxycarboxylic acid and polyol phosphate are magnesium nitrate, calcium nitrate, barium nitrate, iron (II) nitrate, copper (II) nitrate, zinc nitrate, magnesium sulfate , Calcium sulfate, magnesium chloride, calcium chloride, magnesium acetate, calcium acetate, barium acetate, iron (II) acetate, copper acetate (II), zinc acetate, magnesium gluconate, calcium gluconate, barium gluconate, iron gluconate ( 27. The ink set for ink-jet recording according to claim 26, comprising II), copper (II) gluconate, zinc gluconate, magnesium glycerophosphate, and calcium glycerophosphate.   The reducing sugar having 4 or more carbon atoms is at least one selected from D-glucose, D-mannose, D-galactose, D-fructose, D-arabinose, D-ribose, D-xylose and D-erythrose. The ink set for ink-jet recording according to any one of claims 24 to 27, wherein the ink set is for ink-jet recording.   The ink set for ink jet recording according to any one of claims 24 to 28, wherein the color material of the black ink is at least one selected from carbon black and a pigment.   The ink set for inkjet recording according to any one of claims 24 to 28, wherein the color material of the black ink is a dye having at least one carboxyl group.   The ink for ink-jet recording according to any one of claims 24 to 30, wherein the content of water in the black ink and the color ink is 35 to 96 mass% with respect to the total mass of the ink, respectively. set.   32. The ink set for ink jet recording according to claim 24, wherein the color ink is at least one ink selected from the group consisting of yellow ink, magenta ink, and cyan ink.   The ink set includes a heater for applying thermal energy to the ink to discharge the ink from the orifice, and an outermost surface protective layer including a substance selected from a metal and a metal oxide for protecting the heater. The ink set for ink jet recording according to any one of claims 24 to 32, wherein the ink set is an ink set used for an ink jet printer having a recording head.   34. The ink set for inkjet recording according to claim 33, wherein the outermost surface protective layer contains tantalum or a tantalum oxide as a substance selected from a metal and a metal oxide.   (I) Energy for causing ink to be ejected is applied to the black ink included in the ink set according to any one of claims 24 to 34, and the black ink is ejected toward a recording medium to be recorded. A step of applying the ink onto the medium; and (ii) applying energy to the color ink included in the ink set according to any one of claims 24 to 34 to eject the ink, and applying the color ink to the recording medium. And the step (i) and (ii) are performed on the recording medium so that the contact state between the black ink and the color ink is formed. An ink jet recording method characterized by being performed as described above.   36. The inkjet according to claim 35, wherein the black ink and the color ink are applied so as to overlap each other on the recording medium, and the application of the color ink to the recording medium is performed prior to the black ink. Recording method.   37. The ink jet recording method according to claim 35 or 36, wherein the energy is thermal energy.   35. An ink containing portion that contains the ink constituting the ink set according to any one of claims 24 to 34 and energy supplied to the ink supplied from the ink containing portion, respectively. A recording unit comprising an ink jet recording head for discharging.   39. The recording unit according to claim 38, wherein the ink jet recording head includes a heater having an outermost surface protective layer containing a substance selected from a metal and a metal oxide.   40. The recording unit according to claim 39, wherein the substance selected from the metal and the metal oxide includes tantalum or an oxide of tantalum.   35. An ink cartridge comprising an ink storage portion that stores each of the inks constituting the ink set according to any one of claims 24 to 34. An ink containing portion containing an ink set composed of at least a black ink and a color ink, and an ink jet recording head for applying energy to the ink supplied from the ink containing portion and discharging each ink In an inkjet recording apparatus equipped with
35. An ink jet recording apparatus, wherein the ink set is the ink set according to any one of claims 24 to 34.   The ink jet recording head includes a heater having an outermost surface protective layer containing a material selected from a metal and a metal oxide, and the ink jet recording apparatus outputs a pulsed electric signal to the heater according to recording information. 43. The ink jet recording apparatus according to claim 42, further comprising means for applying.   44. The ink jet recording apparatus according to claim 43, wherein the substance selected from the metal and the metal oxide includes tantalum or an oxide of tantalum. The energy (Eop) input to eject the ink has the following relationship:
1.10 ≦ Eop / Eth ≦ 1.90
(Eth is the minimum energy required to eject ink from the recording head).
45. The ink jet recording apparatus according to claim 42, wherein:   An inkjet ink comprising: (a) a polyvalent metal salt; (b) a substance selected from reducing sugars having 4 or more carbon atoms; (c) a liquid medium; and (d) a coloring material.

Images