JP2015199967A - Ink set for inkjet recording, recording device and recorded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink set for inkjet recording capable of forming images having good whiteness, concealment property and scratch resistance to media to be recorded by an inkjet method.SOLUTION: The ink set for inkjet recording contains a first resin particle, a first ink substantially not containing a coloring material and a second ink containing titanium oxide particles, having the content of the first resin particle of less than 6 mass% and discharged with the first ink at substantially same time.

Description

  The present invention relates to an ink set for inkjet recording, a recording apparatus, and a recorded matter.

  In recent years, it has been studied to form a white layer by forming an image on a recording medium other than white (including a light-transmitting recording medium) using a white ink (for example, Patent Document 1). Moreover, it is called label printing and printing is actively performed on containers and packaging of various products. Label printing is often applied to a light-transmitting film, and in such a case, a white ink layer is often formed in advance on the printed surface as a base layer. By forming the underlayer, the shielding property on the back side of the film is increased, and the quality of the image formed on the underlayer can be improved.

  Recently, it has become possible to form an image as described above by an inkjet method. The inkjet method is expected because it can be configured on a small scale as compared with the conventional printing method, and it is not necessary to prepare a plate, so that it is particularly efficient when performing a large number of types and a small amount of printing. . When recording information on containers and packaging of various products, it is common to form a base layer also in the ink jet method, and white inks for forming this are being studied.

JP 2011-020362 A

  When recording information on a light-transmitting medium, the background layer formed using the white ink is required to have at least background shielding, good whiteness, and scratch resistance. As a method for satisfying such properties in the underlayer, for example, more white ink is adhered to the medium, pigment optimization in the white ink, and fixing resin optimization are conceivable.

  Usually, the shielding property and whiteness of the underlayer can be improved by adding more white pigment to the underlayer, and the scratch resistance of the underlayer contains more fixing resin in the underlayer. You can improve it. These can be adjusted to some extent by the amount of white ink used (duty). However, it is more preferable that the white ink itself contains a larger amount of white pigment or fixing resin due to demands for recording speed and the like. It is considered desirable.

  However, if a large amount of white pigment is added to the white ink, precipitation of the white pigment tends to occur, and if a large amount of fixing resin is added to the white ink, the viscosity increases and the white pigment is added. Solidified (sometimes called hard cake). When this occurs, the storage stability of the white ink is lowered, and when the white ink is ejected by ink jetting, there is a possibility of causing problems such as clogging. For this reason, a white ink that is unlikely to cause such a problem is required, but it is difficult to sufficiently satisfy the above-described performance only by changing the composition of the white ink.

The present invention has been made in view of the above-mentioned problems, and one of the objects according to some embodiments thereof is to provide good whiteness, concealment and scratch resistance to a recording medium by an ink jet method. Another object of the present invention is to provide an ink set for ink jet recording and a recording apparatus capable of forming an image having the same, and a recorded matter recorded using the ink set. Another object of some embodiments of the present invention is to provide an ink set for ink jet recording having good storage stability.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

  [Application Example 1] One aspect of the ink set for ink jet recording according to the present invention includes a first ink containing first resin particles and substantially not containing a coloring material, and titanium oxide particles. And a second ink ejected at substantially the same time as the first ink, the content of the resin particles being less than 6% by mass.

  According to the ink set for inkjet recording of this application example, it is possible to form an image having good whiteness, concealment and scratch resistance. That is, the titanium oxide particles blended in the second ink can impart good whiteness and hiding properties to the image, and the first resin particles can impart good scratch resistance to the image. In addition, the ink set for ink jet recording of this application example, in the second ink containing titanium oxide particles, since the blending amount of the first resin particles is small, the titanium oxide particles and the first resin particles are difficult to solidify and stored. Good stability.

  In the present specification, the phrase “the ink does not substantially contain a specific component” refers to a case where an amount that sufficiently exhibits the significance of containing the specific component is not intentionally included. The content of the specific component is less than 0.05% by mass, more preferably less than 0.01% by mass, more preferably less than 0.005% by mass, and most preferably less than 0.001% by mass. Say.

  Moreover, what is described as “resin particles” in the present specification refers to a general term for various resins such as first resin particles and second resin particles.

  Application Example 2 In Application Example 1, the second ink may not substantially contain the first resin particles.

  In the ink set for inkjet recording of this application example, since the first resin particles are not substantially blended in the second ink containing the titanium oxide particles, the titanium oxide particles are hardly solidified in the second ink. The storage stability of the ink set for inkjet recording is particularly good.

  Application Example 3 In Application Example 1 or Application Example 2, the second ink may contain second resin particles different from the first resin particles.

  According to the ink set for inkjet recording of this application example, the titanium oxide particles blended in the second ink can impart good whiteness and concealment to the image, and the first resin particles and the second resin particles Thus, good scratch resistance can be imparted to the image.

  Application Example 4 In any one of Application Examples 1 to 3, the first ink may contain 3% by mass or more and 5% by mass or less of the first resin particles.

  In the ink set for inkjet recording of this application example, since the first resin particles are blended in the first ink that does not substantially contain the color material, the blending of the resin particles in the second ink can be reduced or eliminated. As a result, the storage stability of the second ink becomes better and the viscosity of the first ink is not greatly increased, so that the ejection stability of the first ink can be improved.

  Application Example 5 In any one of Application Examples 1 to 4, the material of the first resin particles may be an acrylic polymer.

  The ink set for inkjet recording of this application example can form an image having better whiteness, concealment and scratch resistance.

  Application Example 6 In any one of Application Examples 1 to 5, the average particle diameter of the first resin particles may be 40 nm or more and 140 nm or less.

  The ink set for inkjet recording of this application example can form an image having better whiteness, concealment and scratch resistance.

  [Application Example 7] In any one of Application Examples 1 to 6, the image forming apparatus may further include a third ink that contains third resin particles different from the first resin particles and substantially does not contain a coloring material. Good.

  According to the ink set for ink jet recording of this application example, white images having different hues in an image formed with the first ink and the second ink and an image formed with the third ink and the second ink are obtained. Can be formed.

  Application Example 8 One aspect of a recording apparatus according to the present invention includes the ink set for ink jet recording described in any one of Application Examples 1 to 7, and is placed at a predetermined position on a recording medium by an ink jet method. An image is formed.

  According to the recording apparatus of this application example, it is possible to form an image having good whiteness, concealment, and scratch resistance. That is, the titanium oxide particles blended in the second ink can impart good whiteness and hiding properties to the image, and at least the first resin particles can impart good scratch resistance to the image. .

  Application Example 9 One aspect of the recording apparatus according to the present invention includes the ink set for ink jet recording according to any one of Application Examples 1 to 7, and includes the first ink and the second ink. A first recording mode in which ink is ejected at substantially the same time and adhered to a predetermined position on the recording medium, and the first ink and the second ink are not ejected at substantially the same time, and are predetermined on the recording medium. A second recording mode to be attached to the position.

  Since the recording apparatus of this application example has the first recording mode and the second recording mode, these modes can be used properly according to the recording medium and the concealment degree of the image. As a result, according to the recording apparatus of this application example, it is possible to balance the time required for image formation and the reduction of the usage amounts of the first ink and the second ink. Therefore, according to the recording apparatus of this application example, for example, a white underlayer can be formed more efficiently.

Application Example 10 One aspect of the recording apparatus according to the invention includes the ink set for ink jet recording according to Application Example 7, and the first ink and the second ink are ejected at substantially the same time to be covered. A first recording mode for adhering to a predetermined position on the recording medium, and a second recording mode for adhering the first ink and the second ink to a predetermined position on the recording medium without ejecting at substantially the same time And a third recording mode in which the second ink and the third ink are ejected at substantially the same time and adhered to a predetermined position on the recording medium.

  Since the recording apparatus of this application example has the first recording mode, the second recording mode, and the third recording mode, these modes can be used properly according to the hue of the image to be formed.

  [Application Example 11] The recording apparatus according to Application Example 9 or Application Example 10, including a determination unit that determines light transmittance of the recording medium, and based on a determination result of the determination unit, at least the mode One kind may be selected and recorded.

  According to the recording apparatus of this application example, the mode can be selected by the determination unit according to the required whiteness, hue, and concealment. Therefore, according to the recording apparatus of this application example, for example, the underlayer can be formed more efficiently.

  Application Example 12 One aspect of the recorded matter according to the present invention is recorded by the recording apparatus described in any one of Application Examples 8 to 11.

  The recorded matter according to this application example has an image having good whiteness, concealment and scratch resistance.

The graph which plotted L * value with respect to duty about the image which concerns on an experiment example. The graph which plotted the concealment degree with respect to duty about the image which concerns on an experiment example.

  Several embodiments of the present invention will be described below. The embodiments described below illustrate examples of the present invention. The present invention is not limited to the following embodiments at all, and includes various modifications that are carried out within the scope not changing the gist of the present invention. Note that not all of the configurations described in the following embodiments are indispensable constituent requirements of the present invention.

1. Ink set for ink jet recording The ink set for ink jet recording according to the present embodiment includes a first ink and a second ink. The ink set for ink jet recording according to this embodiment is used in a recording method for forming an image at a predetermined position on a recording medium by an ink jet method.

1.1. First ink The first ink contains first resin particles. And the 1st ink does not contain a coloring material substantially. Therefore, in the ink set of this embodiment, the first ink has the same properties as a so-called resin ink. Note that “the ink does not substantially contain a coloring material” refers to a case where an amount that sufficiently exhibits the significance of containing the coloring material is not intentionally included. For example, the content of the coloring material in the ink is 0. It is less than 05% by mass, more preferably less than 0.01% by mass, more preferably less than 0.005% by mass, and most preferably less than 0.001% by mass. Moreover, what is described as “resin particles” in the present specification refers to a general term for various resins such as first resin particles and second resin particles.

The material of the first resin particles contained in the first ink is not limited as long as it has the effect of fixing the titanium oxide particles contained in the second ink on the recording medium. For example, a styrene / acrylic acid copolymer , Vinyl chloride polymers, urethane polymers, acrylic acid polymers, and particles of these copolymers. Among these, as the material of the first resin particles, an acrylic resin is preferable in that the degree of concealment and whiteness of the formed image can be further increased, and a styrene / acrylic acid copolymer and acrylic acid are preferable. More preferred are polymers and copolymers thereof.

  When the material of the first resin particles is the material exemplified above, the degree of polymerization of the polymer is not particularly limited, and it may be an oligomer or a polymer of these polymers. Therefore, the weight average molecular weight Mw of the polymer constituting the first resin particles is, for example, 100 or more and 100,000 or less, and preferably 100 or more and 10,000 or less from the viewpoint of dispersibility of the first resin particles.

  The first resin particles are dispersed and contained in the first ink. The first resin particles may be dispersed in the first ink in a state where a part of the particles (for example, near the surface) is dissolved in the liquid contained in the first ink and the inside of the particles is not dissolved. . The first resin particles may be an emulsion or a suspension dispersed in the first ink with a surfactant or the like.

  Since the first resin particles have a dispersed structure in the first ink, the average particle diameter in the dispersed state can be defined. Here, in the present specification, the average particle diameter refers to a volume-based average particle diameter. The volume-based average particle diameter can be obtained, for example, by measuring the dispersed first resin particles using a laser diffraction particle size distribution measuring apparatus based on the dynamic light scattering method.

  When the first resin particles are used in a fine particle state, the average particle diameter is 5 nm or more from the viewpoint of ensuring the storage stability, ejection stability, L * value when used in combination with the second ink, and concealment degree. The range of 400 nm or less is preferable, more preferably 20 nm to 200 nm, more preferably 30 nm to 150 nm, particularly preferably 40 nm to 140 nm, still more preferably 80 nm to 140 nm, and most preferably 100 nm to 140 nm. is there.

  The content of the first resin particles contained in the first ink is arbitrary as long as the first ink can be ejected by the ink jet method. For example, the content is 1% by mass or more and 10% by mass or less with respect to the total amount of the first ink. It can be. In addition, the content of the first resin particles contained in the first ink is preferably 2% by mass or more and 7% by mass or less from the viewpoint that the viscosity of the first ink is easily in a range suitable for the inkjet method. Preferably they are 3 mass% or more and 5 mass% or less. When the content of the first resin particles is within this range, the image formed on the recording medium by the recording method of the present embodiment can be solidified and fixed.

  One of the functions of the first resin particles is to fix the titanium oxide particles blended in the second ink to the recording medium when the first ink and the second ink are attached to the recording medium. That is, one of the functions of the first resin particles is to impart fixability to a recording medium to an image formed using the ink set for ink jet recording of the present embodiment. Therefore, the presence of the first ink can reduce the amount of the fixing resin in the second ink, thereby improving the storage stability of the second ink.

The first resin particles blended in the first ink are, for example, a method of polymerizing (that is, emulsion polymerization) by mixing a polymerization catalyst (polymerization initiator) and a dispersant in a monomer constituting a desired resin, A method obtained by dissolving a resin having a hydrophilic part in a water-soluble organic solvent, mixing the solution in water and then distilling off the water-soluble organic solvent, dissolving the resin in a water-insoluble organic solvent and dispersing the solution And a method obtained by mixing in an aqueous solution. These methods can be appropriately selected according to the type and characteristics of the resin used. Further, a dispersant may be used when dispersing the first resin particles. For example, an anionic surfactant (for example, sodium dodecylbenzenesulfonate, sodium lauryl phosphate, polyoxyethylene alkyl ether sulfate ammonium salt) Etc.), nonionic surfactants (for example, polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylphenyl ether, etc.) can be used alone or in combination The above can be mixed and used.

  Moreover, as a 1st resin particle, a commercial item can also be used, for example, micro gel E-1002, micro gel E-5002 (above a brand name, Nippon Paint Co., Ltd. product), Bon coat 4001, Bon coat 5454 (above goods) Name, manufactured by Dainippon Ink & Chemicals, Inc.), Vinibrand 700, Vinibrand 701 (trade name, manufactured by Nissin Chemical Industry Co., Ltd.), Resamine D-1060, Resamine D-4200 (trade name, manufactured by Dainichi Seika Kogyo Co., Ltd.) ), Mobile 742A, Mobile 972 (trade name, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), SAE1014 (trade name, manufactured by Nippon Zeon Co., Ltd.), Cybinol SK-200 (trade name, manufactured by Seiden Chemical Co., Ltd.), Jonkrill 7100 Jonkrill 390, Jonkrill 711, Jonkrill 511, Jonkri 7001, John Crill 632, John Crill 741, John Crill 450, John Crill 840, John Crill 74J, John Crill HRC-1645J, John Crill 734, John Crill 852, John Crill 7600, John Crill 775, John Crill 537J, John Crill 1535, John Crill PDX-7630A, John Crill 352J, John Crill 352D, John Crill PDX-7145, John Crill 538J, John Crill 7640, John Crill 7641, John Crill 631, John Crill 790, John Crill 780, John Crill 7610, Jonkrill 61J (trade name, manufactured by BASF Japan Ltd.) and the like.

  You may mix | blend a penetrating agent, saccharides, a dispersing agent, water, and another additive with the 1st ink.

<Penetration agent>
The penetrant is preferably at least one selected from alkanediols and glycol ethers. Alkanediols and glycol ethers can enhance the wettability of a recording surface such as a recording medium and improve the ink permeability.

  Examples of the alkanediol include 1,2-alkyldiol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol and other terminal diols, 3- Methyl-1,3-butanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,3-propanediol, 2,4-dimethyl-1,5-pentanediol, 3- (2-methoxy A diol having a branched chain structure such as phenoxy) -1-propanediol can be used. In this embodiment, 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-heptanediol, 1,2-octanediol, etc. , 2-alkanediol is preferred. Among these, 1,2-hexanediol, 1,2-heptanediol, and 1,2-octanediol having 6 to 8 carbon atoms are more preferable because of their particularly high permeability to recording media.

As glycol ethers, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, triethylene glycol Mention may be made of lower alkyl ethers of polyhydric alcohols such as monomethyl ether, triethylene glycol monobutyl ether and tripropylene glycol monomethyl ether. Among these, even better recording quality can be obtained by using triethylene glycol monobutyl ether.

  When the first ink contains at least one selected from these alkanediols and glycol ethers, the content is preferably 1% by mass or more and 20% by mass or less with respect to the total mass of the first ink. More preferably, it is 1 mass% or more and 10 mass% or less.

<Sugar>
In the case where a saccharide is added to the first ink, the wettability of the first ink can be increased, the ink can be prevented from drying, and the clogging suppression effect at the recording head of the ink jet printer can be further increased. The sugar may be composed of a monosaccharide and a disaccharide or higher sugar, may be a monosaccharide only, or may be composed of only a disaccharide or higher sugar. The type of sugar is appropriately selected within the range of the desired effect. That is, when it is desired to place an emphasis on the effect of suppressing solidification, it may be composed of only sugars of disaccharides or higher (not containing monosaccharides). Moreover, when it comprises only saccharide | sugar more than a disaccharide, the saccharide | sugar may be only saccharide | sugar more than a disaccharide and a trisaccharide. The first ink may contain a monosaccharide, a disaccharide or higher sugar (oligosaccharide (including trisaccharide and tetrasaccharide) and polysaccharide). Examples of monosaccharide and disaccharide or higher sugars include glucose, ribose, mannitol, mannose, fructose, ribose, xylose, arabinose, galactose, aldonic acid, glucitol, (sorbitol), maltose, cellobiose, lactose, sucrose, trehalose, Such as maltotriose. Here, the polysaccharide means a saccharide in a broad sense, and includes a substance that exists widely in nature, such as alginic acid, α-cyclodextrin, and cellulose. In addition, the derivatives of these sugars are represented by the reducing sugars of the sugars described above (for example, sugar alcohols (general formula HOCH ₂ (CHOH) _n CH ₂ OH (where n represents an integer of 2 to 5)). , Oxidized sugars (eg, aldonic acid, uronic acid, etc.), amino acids, thio sugars, etc. The type of sugar is not particularly limited, but reducing sugars are particularly preferred, and specific examples include glucose, fructose, etc. Can be mentioned.

  In addition, when a monosaccharide and a disaccharide or more sugar are added to the first ink, the ratio of the monosaccharide is 5% by mass or more and 50% by mass or less with respect to the total sugar contained in the ink. Is more preferable, and more preferably 20% by mass or more and 45% by mass or less. As a result, sugar acts as a humectant and can prevent nozzle clogging of the recording head. In addition, it is more preferable that the sugar contains a trisaccharide. When trisaccharide is contained, the content is not particularly limited, but is preferably 3% by mass or more and 90% by mass or less, and more preferably 25% by mass or more and 85% by mass or less. In addition, when adding monosaccharides and disaccharides or more sugars to the ink, monosaccharides and disaccharides or more sugars may be added separately, or mixed sugars containing two (for example, syrup) may be added. Good.

  Examples of commercially available reducing sugar products include “HS-500” (manufactured by Hayashibara Corporation), “HS-300” (manufactured by Hayashibara Corporation), “HS-60” (manufactured by Hayashibara Corporation), “HS”. -30 "(produced by Hayashibara Corporation)," HS-20 "(produced by Hayashibara Corporation), and the like.

  The addition amount in the case of adding saccharides to the first ink is preferably, for example, about 2% by mass to 10% by mass, and more preferably about 5% by mass to 8% by mass with respect to the total amount of the first ink. .

<Dispersant>
As the dispersant that can be blended in the first ink, those that can be used for general pigment inks can be used without particular limitation. Examples of such a dispersant include a cationic dispersant, an anionic dispersant, a nonionic dispersant, a surfactant, and the like. The first ink does not substantially contain a color material. However, according to the dispersant described here, for example, the dispersibility of the first resin particles can be improved.

  Examples of anionic dispersants include polyacrylic acid, polymethacrylic acid, acrylic acid-acrylonitrile copolymer, vinyl acetate-acrylic acid ester copolymer, acrylic acid-acrylic acid alkyl ester copolymer, styrene-acrylic acid. Copolymer, styrene-methacrylic acid copolymer, styrene-acrylic acid-alkyl acrylate copolymer, styrene-methacrylic acid-alkyl acrylate copolymer, styrene-α-methylstyrene-acrylic acid copolymer Styrene-α-methylstyrene-acrylic acid-alkyl acrylate copolymer, styrene-maleic acid copolymer, vinyl naphthalene-maleic acid copolymer, vinyl acetate-ethylene copolymer, vinyl acetate-fatty acid vinyl ethylene Copolymer, vinyl acetate-maleic ester Examples include copolymers, vinyl acetate-crotonic acid copolymers, vinyl acetate-acrylic acid copolymers, and the like. Nonionic dispersants include polyvinyl pyrrolidone, polypropylene glycol, vinyl pyrrolidone-vinyl acetate copolymer, and the like. Surfactants as dispersants include anionic surfactants such as sodium dodecylbenzene sulfonate, sodium lactylate, ammonium salt of polyoxyethylene alkyl ether sulfate, polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, poly Nonionic surfactants such as oxyethylene sorbitan fatty acid ester, polyoxyethylene alkylphenyl ether, polyoxyethylene alkylamine, polyoxyethylene alkylamide, and the like. From the viewpoint of particularly improving the dispersion stability of the first resin particles, it is preferable to use a styrene- (meth) acrylic acid copolymer.

  The first ink may contain an acetylene glycol surfactant or a polysiloxane surfactant. Acetylene glycol surfactants or polysiloxane surfactants can increase the wettability of a recording surface such as a recording medium and improve the ink permeability. The dispersant that can be blended in the first ink is not limited to the above-described surfactant, and other known surfactants such as a fluorine-based surfactant may be used.

Examples of acetylene glycol surfactants include 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, and 3,5. -Dimethyl-1-hexyne-3ol, 2,4-dimethyl-5-hexyn-3-ol and the like. Moreover, a commercial item can also be utilized for acetylene glycol-type surfactant, for example, Olphine E1010, STG, Y (above, Nissin Chemical Co., Ltd. product), Surfynol 104, 82, 465, 485, TG ( Above, Air Products
and Chemicals Inc. Manufactured).

  Moreover, as a polysiloxane type surfactant, a commercial item can be utilized, for example, BYK-347, BYK-348 (above, Big Chemie Japan Co., Ltd. product) etc. are mentioned.

  The blending amount when the dispersant is blended with the first ink is preferably 0.01% by mass or more and 5% by mass or less, and more preferably 0.1% by mass or more with respect to the total mass of the first ink. 0.5% by mass or less.

<Water>
The first ink may be a so-called aqueous ink containing 50% or more of water. It is preferable to use pure water or ultrapure water such as ion exchange water, ultrafiltered water, reverse osmosis water, or distilled water. In particular, water obtained by sterilizing these waters by irradiation with ultraviolet rays or addition of hydrogen peroxide is preferable because generation of mold and bacteria can be suppressed for a long time.

<Other additives>
In addition, the first ink may include a fixing agent such as a water-soluble rosin, an antifungal agent / preservative such as sodium benzoate, an antioxidant / ultraviolet absorber such as an allophanate, a chelating agent, and an oxygen absorber as necessary. Etc. can be contained. These additives can be used alone or in combination of two or more. Furthermore, a pH adjuster, an antiseptic / fungicide, a rust inhibitor, a chelating agent and the like can be contained. When these materials are contained in the first ink, the characteristics may be further improved.

  Examples of the pH adjuster include potassium dihydrogen phosphate, disodium hydrogen phosphate, sodium hydroxide, lithium hydroxide, potassium hydroxide, ammonia, diethanolamine, triethanolamine, triisopropanolamine, potassium carbonate, sodium carbonate, Examples thereof include sodium hydrogen carbonate.

  Examples of antiseptics and fungicides include sodium benzoate, sodium pentachlorophenol, 2-pyridinethiol-1-oxide sodium, sodium sorbate, sodium dehydroacetate, 1,2-dibenzisothiazoline-3-one Etc. Examples of commercially available products include Proxel XL2, Proxel GXL (above trade name, manufactured by Avicia), Denside CSA, NS-500W (above trade name, manufactured by Nagase ChemteX Corporation), and the like.

  Examples of the rust inhibitor include benzotriazole.

  Examples of the chelating agent include ethylenediaminetetraacetic acid and salts thereof (such as ethylenediaminetetraacetic acid dihydrogen disodium salt).

  The first ink may use an organic solvent in addition to water as a solvent. Examples of such an organic solvent include alkyl alcohols having 1 to 4 carbon atoms such as ethanol, methanol, butanol, propanol, isopropanol, 2-pyrrolidone, formamide, acetamide, dimethyl sulfoxide, sorbit, sorbitan, acetin, diacetin, Examples include triacetin, sulfolane, glycerin, ethylene glycol, and propylene glycol. By using such an organic solvent, the permeability to the recording medium can be improved and nozzle clogging can be prevented. These may be used alone or in combination of two or more, and are preferably contained in an amount of about 0.1% by mass or more and 10% by mass or less based on the total mass of the inkjet ink.

  The first ink can be prepared in the same manner as the conventional pigment ink using a conventionally known apparatus such as a ball mill, a sand mill, an attritor, a basket mill, or a roll mill. In the preparation, it is preferable to remove coarse particles using a membrane filter or a mesh filter.

1.2. Second ink The second ink contains titanium oxide particles. The second ink contains substantially no resin particles or contains less than 6% by mass of resin particles (that is, the content of resin particles is less than 6% by mass). When the resin particles are contained, the content of the resin particles (total amount of resin in the ink) is preferably 2% by mass or more and less than 6% by mass from the viewpoint of whiteness, abrasion resistance and the like, and 2% by mass or more. 5 mass% or less is still more preferable, and 2 mass% or more and 4.5 mass% or less are more preferable.

Examples of the titanium oxide particles contained in the second ink include titanium dioxide particles in which titanium dioxide is powdered. The particle size and particle size distribution of the titanium oxide particles are arbitrary as long as the second ink can be ejected by the ink jet method. However, the average particle diameter of the titanium oxide particles is 15 in that the whiteness and hiding property of the formed image can be further increased.
It is preferably 0 nm or more and 500 nm or less, more preferably 250 nm or more and 400 nm or less, and most preferably 285 nm or more and 380 nm or less.

  The content (solid content) of the titanium oxide particles is preferably 1% by mass or more and 20% by mass or less, and more preferably 5% by mass or more and 15% by mass or less with respect to the total mass of the second ink.

  When the second ink contains resin particles, one of the functions of the resin particles is to fix the titanium oxide particles contained in the second ink on the recording medium. Further, when resin particles are contained, an effect of improving the whiteness and concealment degree of an image formed by the ink set for ink jet recording of the present embodiment may be obtained. In addition, an effect of changing the saturation may be obtained.

  The second ink may contain a second resin particle of a different type from the first resin particle described above. The second resin particles are substantially the same as the first resin particles described in the section “1.1. First ink”, but particles of a material different from the material of the first resin particles are selected.

  The first resin particles and the second resin particles may change the saturation of the white ink, and the second ink alone can be obtained by differentiating the types of resin particles of the first ink and the second ink. When recording. There are cases where various chromas can be expressed by using both the first ink and the second ink, and ejecting them at substantially the same time and mixing them on the recording medium.

  Similar to the first ink, the second ink may contain a penetrant, a saccharide, a dispersant, water, and other additives. Since these components are the same as those described in the section “1.1. First ink”, description thereof is omitted.

  In addition, when saccharide | sugar contains in 2nd ink, saccharide | sugar adsorb | sucks to a titanium oxide particle and suppresses aggregation of particle | grains as one of the functions of saccharide | sugar.

1.3. Other Configurations The ink set of the present embodiment may be configured to include other inks. For example, the ink set of the present embodiment may include a third ink that contains third resin particles made of a material different from the first resin particles described above and does not substantially contain a color material. The third ink is substantially the same as the first ink except that it contains third resin particles.

  Depending on the type of polymer selected as the material of the first resin particles and the third resin particles, the first resin particles and the image formed on the recording medium when attached to the recording medium together with the titanium oxide particles. There may be a case where a hue difference can be generated between the third resin particles. Therefore, when the ink set includes the third ink including the third resin particles of a type different from the first resin particles contained in the first ink, the second ink is compared with the first ink on the recording medium. By adjusting the mixing ratio of the third ink and the third ink, the hue of the formed image can be changed.

2. Recording Method and Recording Apparatus A recording method according to the present embodiment is a recording method in which an image is formed at a predetermined position on a recording medium by an inkjet method using the above-described ink set for inkjet recording.

The recording medium is not particularly limited, and examples thereof include a non-ink-absorbing medium or a low-absorbing medium. As a non-ink-absorbing recording medium, for example, plastic film is coated on a substrate such as a plastic film or paper that has not been surface-treated for inkjet printing (that is, an ink-absorbing layer is not formed). Examples thereof include ones to which a plastic film is adhered, glass, metal and the like. Examples of the plastic here include polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, and polypropylene. Examples of the recording medium having low ink absorption include printing paper such as art paper, coated paper, and matte paper. In addition to the above recording medium, non-ink-absorbing or low-absorbing media such as metal and glass may be used.

Here, in this specification, “ink non-absorbing or low-absorbing recording medium” means “the amount of water absorption from the start of contact to 30 msec ^1/2 in the Bristow method is 10 mL / m ² or less. Recording medium ". This Bristow method is the most popular method for measuring the amount of liquid absorbed in a short time, and is adopted by the Japan Paper and Pulp Technology Association (JAPAN TAPPI). For details of the test method, refer to Standard No. of “JAPAN TAPPI Paper Pulp Test Method 2000”. 51 "Paper and paperboard-Liquid absorbency test method-Bristow method". In the present specification, the “ink non-absorbing or low-absorbing recording medium” may be simply referred to as “plastic medium”.

  The ink jet method is a method adopted in a general ink jet printer, and means a method of forming an image by ejecting ink from nozzles and attaching the ink to a recording medium. Specific examples of the inkjet method include conventionally known inkjet methods such as thermal jet inkjet, piezo inkjet, continuous inkjet, roller application, and spray application.

  In the recording method of the present embodiment, at least a first step of attaching the first ink droplet to the predetermined position on the recording medium, and the second ink droplet to the predetermined position on the recording medium. A second step of attaching. In the first step and the second step, after one step is finished, the liquid attached to the predetermined position in the one step has fluidity, and the liquid in the other step is liquidated by the other step. Drops are deposited in place.

  In other words, in the recording method of the present embodiment, the first ink droplet and the second ink droplet are attached at substantially the same time. Therefore, at least a part of the first ink droplet and the second ink droplet are mixed before being completely dried and solidified. The order of the first step and the second step is not limited. However, if the second step is performed before the first step, the titanium oxide particles adhere to the vicinity of the recording medium. It is more preferable in terms of sex.

  Here, “substantially the same time” means that the ink droplets of one ink and the other ink are ejected at a timing at which they can be mixed with each other. In addition, the case where one ink is ejected while the other ink is flowing on the recording medium is included. Furthermore, for example, when using a general inkjet printer of a type that ejects ink by scanning nozzles with respect to a recording medium, it is within one scan (hereinafter also referred to as “one pass”). The case where one specific image is formed by both the second ink and the first ink. Accordingly, in addition to the case where both inks are ejected at exactly the same time, the case where one ink is ejected in one pass and the other ink is ejected is also included in “substantially the same time”.

Also, the two types of ink droplets ejected during one scan are brought into contact with each other on the recording medium. Note that the liquid droplets may be contacted with the liquid droplets that have previously adhered to the recording medium and exist on the recording medium. Of the liquid droplets may simultaneously adhere to and contact the recording medium. Further, the recording on one recording medium may be completed by performing scanning a plurality of times, or the recording on one recording medium can be performed by scanning the recording medium only once at a high speed. It may be completed. As an example of the latter case, a so-called line printer using a head having a length corresponding to the width of the recording medium can be used. The first ink droplet and the second ink can also be used by such a printer. The liquid droplets can be attached at substantially the same time and at least partially in contact with the recording medium.

  The recording apparatus used in the recording method used in the present embodiment includes a first recording mode in which the first ink and the second ink are ejected at substantially the same time to adhere to the recording medium, and the second ink is the first ink. It is preferable to have a second recording mode in which the ink is deposited at a predetermined position on the recording medium without being ejected at substantially the same time as the ink. When the first recording mode is used, a white image having an L * value higher than that of the second recording mode, a concealment degree, and a saturation different from that of the second recording mode is obtained. The second recording mode is preferable to the first recording mode in that the consumption of the first ink can be suppressed. Such first recording mode and second recording mode may be configured to be selected based on an input image, a user instruction, and the like.

  In the recording method according to the present embodiment, the first ink droplet weight is preferably 20% or more and 50% or less with respect to the second ink droplet weight. Thereby, the drying property of the image formed on the plastic medium can be improved.

  In the present specification, the “white ink” is an ink (ink) capable of recording a color called “white” for the sake of social wisdom, and includes ink that is slightly colored. Moreover, the ink (ink) containing the pigment includes an ink (ink) which is named and sold under a name such as “white ink (ink), white ink (ink)”. Further, for example, when ink (ink) is recorded on Epson genuine photographic paper <Glossy> (manufactured by Seiko Epson Corporation) with an amount of 100% duty or more or an amount sufficient to cover the surface of the photographic paper, the brightness of the ink (L *) and chromaticity (a *, b *) are measured using a spectrophotometer Spectrolino (trade name, manufactured by GretagMacbeth), measurement conditions are D50 light source, observation field is 2 °, density is DIN NB, white When the measurement was performed with the reference set to Abs, the filter set to No, and the measurement mode set to Reflectance, 70 ≦ L * ≦ 100, −4.5 ≦ a * ≦ 2, −6 ≦ b * ≦ 2.5 Ink is included to indicate the range.

  Further, the selection of the above-described mode in such a recording apparatus may be performed, for example, according to the light transmittance of the recording medium. Specifically, it is only necessary that the recording apparatus has a determination unit that determines the light transmission degree of the recording medium. As an example of the determination means, there is a mode in which the user inputs the “model number, property (light transmission)”, etc. of the recording medium from the host device, and receives and determines it. As another mode, a check box for determining that the recording medium is light-transmitting is displayed on the screen of the host device, and when the check box is checked, it is received and determined. good. Further, a mode in which a sensor that directly detects the light transmission degree is provided in the recording apparatus and data of the detection result is received and determined may be used. Examples of the determination unit are not particularly limited, and examples thereof include a CPU and an ASIC. In this way, it is possible to select a mode according to the required degree of concealment, for example, to form a white underlayer more efficiently.

  In addition, the recording method of the present embodiment may be configured to include an ink set including the first ink, the second ink, and the third ink described above. The recording apparatus used in this case has a first recording mode in which the first ink and the second ink are ejected at substantially the same time to adhere to the recording medium, and the second ink is substantially the same as the first ink. And the second recording mode in which the second ink and the third ink are ejected at substantially the same time and discharged to a predetermined position on the recording medium. It is preferable to have a third recording mode to be adhered. These three modes may be selected according to the light transmittance of the recording medium as described above.

  In such a recording method, these modes can be properly used according to a desired hue of an image to be formed. Therefore, according to the recording apparatus of the present embodiment, for example, the color tone of the white underlayer can be easily changed.

  Further, the mode selection in such a recording apparatus may be performed according to the color tone of the recording medium, for example. In this way, the mode can be selected according to the required color tone, and for example, the color tone of the white underlayer can be easily changed. The mode may be selected by the user, or the mode may be automatically selected by providing the recording apparatus with a mechanism for measuring the color tone of the recording medium.

3. Experimental Examples Hereinafter, the present invention will be described in more detail with reference to experimental examples, but these do not limit the scope of the present invention.

3.1. Preparation of ink White ink A1 to A10 (corresponding to the fourth ink in the above embodiment), white ink B (corresponding to the second ink in the above embodiment that does not substantially contain resin particles). ) And resin inks C1 to C10 (corresponding to the first ink in the above embodiment) were prepared with the formulations shown in Table 1.

In Table 1, as resin particles, Joncrill 61J (manufactured by BASF Japan Ltd .: styrene / acrylic copolymer system), Vinyl Blanc 700 (manufactured by Nissin Chemical Industry Co., Ltd .: polyvinyl chloride), Resamine D-1060 (large) Nissei Kagaku Kogyo Co., Ltd .: urethane resin type), Movinyl 742A (acrylic resin type), and Movinyl 972 (styrene / acrylic resin type) (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) were purchased and used. In Table 1, the titanium dioxide particles are “NanoTek (R) Slurry” (manufactured by CI Kasei Co., Ltd.): NanoTek (R) Slurry is a slurry containing titanium dioxide particles having an average particle diameter of 300 nm at a solid content concentration of 15%. Were blended. In Table 1, the concentration of the titanium dioxide particles and the resin particles is shown in mass% as the solid content concentration. In Table 1, HS-500 is a sugar manufactured by Hayashibara Corporation. In the table, BYK-348 is a polysiloxane surfactant manufactured by Big Chemie Japan Co., Ltd. Water used was ion exchange water.

3.2. Evaluation of clogging and solidification Evaluation of clogging was performed as follows. Each of the above inks was filled in an ink chamber of a dedicated cartridge of an ink jet printer (trade name “PX-G930” manufactured by Seiko Epson Corporation). Then, the ink cartridge was mounted on the printer, left in an environment of room temperature of 25 ° C. and humidity of 50% RH for half a year, and the number of clogged nozzles was counted each time a cleaning operation was performed.

  The results obtained were evaluated using the following criteria and are listed in Table 2.

○: No clogged nozzles disappeared within 5 cleaning cycles △: No clogged nozzles disappeared within 10 cleaning cycles ×: No clogged nozzles disappeared after 11 cleaning cycles Solidification was evaluated as follows. It was. 100 ml of each of the above inks is placed in a 100 ml screw tube bottle (AS ONE), left in an environment of room temperature 25 ° C. and humidity 50% RH for six months, shaken up and down 10 times in a width of 30 cm, and then screw tube 3 mL of the ink supernatant in the bottle was collected.

  Distilled water was added to 1 g of the collected supernatant and diluted 1000 times. Subsequently, using a spectrophotometer (product name “Spectrophotometer U-3300”, manufactured by Hitachi, Ltd.), the absorbance (Abs value) at a wavelength of 500 nm of the diluted white ink composition was measured for each number of stirring. The absorbance of each sample thus obtained was compared with the absorbance of the white ink composition immediately after the adjustment, and the absorbance recovery rate was determined using the following formula (1).

Absorbance recovery rate (%) = 100 × absorbance of sample / absorbance immediately after adjustment (1)
The results obtained were evaluated using the following criteria and are listed in Table 2.

○: Recovery rate is 90% or more △: Recovery rate is 70% or more and less than 90% ×: Recovery rate is less than 70%

3.3. Evaluation of whiteness, hiding degree and scratch resistance Tables 3 and 4 show evaluation results of whiteness, hiding degree and scratch resistance.

  Samples for evaluating whiteness, hiding, and scratch resistance were prepared as follows.

  White inks and resin inks of the types shown in Table 3 and Table 4 were filled in the ink chambers of dedicated cartridges of an inkjet printer (trade name “PX-G930” manufactured by Seiko Epson Corporation). Then, a solid pattern image was recorded on a recording medium (CPF (manufactured by Seiko Epson Corporation, clear proof film WXCPFT27R)). The recording was performed with the resolution shown in Tables 3 and 4 at a resolution of 1440 × 1440 dpi.

  Here, “duty” is a value calculated by the following equation.

duty (%) = number of actual printing dots / (vertical resolution × horizontal resolution) × 100
(Where “number of actual print dots” is the number of actual print dots per unit area, and “vertical resolution” and “horizontal resolution” are resolutions per unit length. (This means the maximum ink mass of a single color.)
The recording was performed by setting the droplets of the white ink on the recording medium and then setting the droplets of the resin ink to adhere to the position of the white ink on the recording medium. Then, the resin ink droplets were allowed to adhere while the white ink droplets had fluidity. That is, the setting was made such that the resin ink is ejected after ejecting the white ink in one scanning of the head of the ink jet printer. The time from when the white ink adhered to the recording medium to when the resin ink reaches the white ink was about 0.1 ms. It was confirmed by a separate experiment that each white ink did not dry within 1.5 ms after adhering to the recording medium and had fluidity.

  The whiteness was evaluated by measuring each sample with a colorimeter: Gretag Macbeth Sptroscan and Spectrolino (manufactured by X-Rite) to obtain an L * value, a * value, and b * value. This was done as an index of whiteness. The measured L * value, a * value, and b * value are shown in Tables 3 and 4.

  The degree of concealment is shown in Tables 3 and 4 as the degree of concealment by measuring the transmittance of each sample in the visible light region. The degree of concealment was obtained as follows. For each sample, a spectrophotometer (V550 UV / VIS) manufactured by JASCO Corporation was used as a measurement program, and Spectra Manager for windows 95 / NT (ver. 1.53.01) manufactured by JASCO Corporation. , Measurement mode: transmission mode (% T), polarization data: N polarization, number of repetitions: 1, response: Fast, bandwidth: 10.0 nm, scanning speed: 2000 nm / min, data acquisition interval: 1.0 nm The transmittance in the visible light region was measured.

  And the integral value of the transmittance | permeability was calculated | required by integrating the transmittance | permeability in each wavelength of 1 nm space | interval of 380 nm-700 nm. The integral value is a numerical value between 0 and 32000, 0 for complete shielding (hiding) and 32000 for complete transmission.

  For scratch resistance, after each sample was dried at 60 ° C. and humidity 20% RH for 2 hours, it was used for a JIS dye fastness test using a Gakushin type dyeing friction fastness tester (manufactured by Yasuda Seiki Seisakusho). The printed area of the sample was evaluated by rubbing 100 times with a white cloth (manufactured by Japanese Standards Association).

  The following criteria were used for evaluation, and the evaluation results are shown in Tables 3 and 4.

○: No peeling △: Less than 10% of the printed area was peeled ×: More than 10% of the printed area was peeled

3.4. Results of Experimental Example Table 2 shows that the white inks A1 to A10 were inferior to the white ink B in terms of clogging and solidification. This is presumably because the titanium oxide particles and the resin particles are mixed in the white ink, resulting in aggregation of titanium oxide particles and solidification (formation of a hard cake). Further, the white inks A1 to A5 had better clogging and solidification performance than the white inks A6 to A10. This indicates that aggregation and solidification of the titanium oxide particles are suppressed when the concentration of the first resin particles in the white ink is about 3%. On the other hand, as a result of the absence of resin particles, the white ink B was not clogged or solidified even after storage for half a year, and the storage stability was very good. Therefore, a smaller amount (less than 3% by mass) of resin particles is added to the white ink than when the resin particles are added to the white ink, or the resin particles are not added to the white ink. It has been found that the storage stability of an ink set containing white ink can be improved by adding resin particles to the resin ink.

It can be seen from Table 3 that the L * value increases as the duty of the resin ink increases. Further, in Table 3, in the images recorded with the white ink B and the resin inks C1 to C4 and the images recorded with the white inks A1 to A5, the duty (resin ink duty is equal) is equal. 42%), the whiteness of the two was comparable, and the former was equal or greater. In particular, the images formed using the resin inks C1, C4, and C5 were superior in whiteness to the images recorded with the white inks A1, A4, and A5. That is, when acrylic resin-based resin particles or styrene / acrylic copolymer-based resin particles are used, resin particles are supplied by the resin ink rather than when resin particles are added to the white-based ink. It turned out that whiteness becomes higher. In addition, the average particle diameter of the resin particles used in the resin inks C1, C4, and C5 is in the range of 40 nm to 140 nm, and it has been found that this contributes to improving the whiteness.

  Moreover, when Table 3 is seen, it turns out that the value of a * and b * changes with the kind of used resin particle. From this, it was found that the hue (color) of the formed white image can be changed depending on the type of resin particles used.

  Further, it can be seen from Tables 3 and 4 that as the duty of the resin ink increases, the degree of concealment decreases and an image with high shielding properties can be obtained. Further, in an image recorded with the white ink B and the resin inks C1 to C4 and an image recorded with the white inks A1 to A5, the solid content amount is equal (duty of the resin ink is 42%). Comparing the degree of concealment between the two, the former had a better degree of concealment. In particular, the image formed using the resin inks C1 and C3 has a significantly improved concealment property than the images recorded with the white inks A1 and A3. That is, when using resin particles of a styrene / acrylic copolymer system or a urethane resin system, the degree of concealment is better when the resin particles are supplied with the resin ink than when the resin particles are added to the white ink. It turned out to be good.

  The mechanism for obtaining the above results is not clear at present, but the presence of titanium oxide particles in the image is more pronounced when white ink and resin ink are used than when only white ink is used. It is thought that this is due to the fact that it occurs more frequently.

  Regarding the scratch resistance, it can be seen that good results can be obtained if any kind of resin particles are present in the image. However, when the resin ink C1 was used, the scratch resistance was slightly inferior when the duty was 30% or less.

  FIG. 1 is a graph in which L * values are plotted with respect to the duty of the resin ink for the samples shown in Table 3. FIG. 2 is a graph plotting the degree of concealment with respect to the duty of the resin ink for the samples in Table 3.

  Also, from Table 4, it can be seen that, as in Table 3, the L * value increases as the duty of the resin ink increases. In particular, images formed using the resin inks C1, C4, and C5 were excellent in whiteness. That is, it has been found that when acrylic resin-based resin particles or styrene / acrylic copolymer resin particles are used, the whiteness increases. In addition, the average particle diameter of the resin particles used in the resin inks C1, C4, and C5 is in the range of 40 nm to 140 nm, and it has been found that this contributes to improving the whiteness.

  Further, it can be seen from Table 4 that as the duty of the resin ink increases, the degree of concealment decreases and an image with high shielding properties can be obtained. In particular, the concealability of the image formed using the resin inks C4 and C5 was greatly improved. That is, it has been found that the concealment degree is good when using acrylic resin-based or styrene / acrylic copolymer resin particles.

  The mechanism for obtaining the above results is not clear at present, but the presence of titanium oxide particles in the image is more pronounced when white ink and resin ink are used than when only white ink is used. It is thought that this is due to the fact that it occurs more frequently.

  Regarding the scratch resistance, it can be seen that good results can be obtained if any kind of resin particles are present in the image. However, when the resin ink C1 was used, the scratch resistance was slightly inferior when the duty was 30% or less.

  The present invention is not limited to the embodiment described above, and various modifications are possible. For example, the present invention includes substantially the same configuration (for example, a configuration having the same function, method, and result, or a configuration having the same purpose and effect) as the configuration described in the embodiment. In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that achieves the same effect as the configuration described in the embodiment or a configuration that can achieve the same object. In addition, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

Claims (12)

A first ink containing first resin particles and substantially free of a coloring material;
A second ink containing titanium oxide particles, wherein the content of the first resin particles is less than 6% by mass, and is ejected at substantially the same time as the first ink;
An ink set for inkjet recording, comprising: In claim 1,
The ink set for inkjet recording, wherein the second ink does not substantially contain the first resin particles. In claim 1 or claim 2,
The ink set for ink-jet recording, wherein the second ink contains second resin particles different from the first resin particles. In any one of Claims 1 thru | or 3,
The ink set for ink jet recording, wherein the first ink contains the first resin particles in an amount of 3% by mass to 5% by mass. In any one of Claims 1 thru | or 4,
The ink set for ink jet recording, wherein the material of the first resin particles is an acrylic polymer. In any one of Claims 1 thru | or 5,
The ink set for inkjet recording, wherein the average particle diameter of the first resin particles is 40 nm or more and 140 nm or less. In any one of Claims 1 thru | or 6,
An ink set for inkjet recording, further comprising a third ink containing third resin particles different from the first resin particles and substantially not containing a coloring material.   A recording apparatus comprising the ink set for ink jet recording according to any one of claims 1 to 7, and forming an image at a predetermined position on a recording medium by an ink jet method. An ink set for ink jet recording according to any one of claims 1 to 7,
A first recording mode in which the first ink and the second ink are ejected at substantially the same time and adhered to a predetermined position on the recording medium;
A second recording mode in which the first ink and the second ink are not ejected at substantially the same time and adhered to a predetermined position on the recording medium;
A recording apparatus. An ink set for ink jet recording according to claim 7,
A first recording mode in which the first ink and the second ink are ejected at substantially the same time and adhered to a predetermined position on the recording medium;
A second recording mode in which the first ink and the second ink are not ejected at substantially the same time and adhered to a predetermined position on the recording medium;
A third recording mode in which the second ink and the third ink are ejected at substantially the same time and adhered to a predetermined position on the recording medium;
A recording apparatus. The recording apparatus according to claim 9 or 10, wherein:
A judging means for judging the light transmittance of the recording medium;
A recording apparatus that performs recording by selecting at least one of the modes based on a determination result of the determination unit.   A recorded matter recorded by the recording apparatus according to any one of claims 8 to 11.

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