JP2019038149A - Ink jet recording method and ink jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording method capable of suppressing the precipitation of silver atoms. An ink jet recording method using an ink jet recording apparatus comprising a water-based ink and a member made of at least one material selected from the group consisting of silicon and a silicon compound while being in contact with the water-based ink, The water-based ink contains silver particles, a compound represented by the general formula (1), a compound having a structure represented by the general formula (2), a compound represented by the general formula (3), and the general formula (4). And at least one compound selected from the group consisting of compounds represented by formula (1): [Selection figure] None

Description

  The present invention relates to an ink jet recording method and an ink jet recording apparatus.

  Ink containing metal particles has been used to form electrical circuits by utilizing the characteristics of the metal particles used, but in recent years it has been used for applications that express metallic feelings such as Christmas cards. It has become to. In order to record a metallic image, a water-based ink containing silver particles and sodium thiocyanate has been proposed (see Patent Document 1). Further, an aqueous ink containing silver particles and ammonium citrate has been proposed (see Patent Document 2). Furthermore, an aqueous ink containing silver particles and sodium carboxymethylcellulose has been proposed (see Patent Document 3).

JP 2013-177529 A JP 2004-256757 A International Publication No. 2003/038002

  A member (silicon member) composed of at least one material selected from the group consisting of silicon and a silicon compound, such as an ink flow path forming member of a recording head, with the aqueous ink described in Patent Documents 1 to 3 The present invention was studied by applying to an inkjet recording apparatus provided. As a result, it was found that silver atoms (Ag) were deposited around the silicon member.

  Accordingly, an object of the present invention is to provide a water-based ink and an ink-jet recording method capable of suppressing the precipitation of silver atoms when using an ink-jet recording apparatus that is in contact with the water-based ink and includes a silicon member. Another object of the present invention is to provide an ink jet recording apparatus used in the ink jet recording method.

  The above object is achieved by the present invention described below. That is, the ink jet recording method of the present invention is an ink jet using an ink jet recording apparatus comprising a water-based ink and a member made of at least one material selected from the group consisting of silicon and a silicon compound while being in contact with the water-based ink. In the recording method, the water-based ink is represented by silver particles, a compound represented by the following general formula (1), a compound having a structure represented by the following general formula (2), and the following general formula (3). And an at least one compound selected from the group consisting of compounds represented by the following general formula (4).

(In the general formula (1), R ₁₁ and R ₁₂ are each independently an alkyl group, a hydroxyalkyl group, or a hydroxy group, except when R ₁₁ and R ₁₂ are both hydroxy groups. .)

(In General Formula (2), R ₂₁ , R ₂₂ , R ₂₃ , and R ₂₄ are each independently a hydrogen atom, an alkyl group, a hydroxyalkyl group, a carboxyalkyl group, or a sulfonic acid group. The compound having the structure represented by 2) is a monosaccharide or a compound having 2 or more sugars, and in the case of a compound having 2 or more sugars, the 1st carbon and the 2nd, 3rd or 4th carbon Is a compound in which a monosaccharide and a monosaccharide are linked by a single bond.

(In General Formula (3), M is a hydrogen atom, an alkali metal, ammonium, or organic ammonium. R ₃₁ and R ₃₂ are each independently a hydrogen atom, an alkyl group, a hydroxyalkyl group, or a carboxyalkyl. Group.)

(In General Formula (4), A is a nitrogen atom or a phosphorus atom. R ₄₁ , R ₄₂ , R ₄₃ , and R ₄₄ are each independently an alkyl group, a hydroxyalkyl group, or a carboxyalkyl group. is there.)

  The present invention is also an ink jet recording apparatus comprising: a water-based ink; and a member that is in contact with the water-based ink and includes at least one material selected from the group consisting of silicon and a silicon compound. Are represented by silver particles, a compound represented by the general formula (1), a compound having a structure represented by the general formula (2), a compound represented by the general formula (3), and the general formula (4). The present invention relates to an ink jet recording apparatus comprising at least one compound selected from the group consisting of:

  ADVANTAGE OF THE INVENTION According to this invention, when using an inkjet recording device provided with the member comprised with at least 1 sort (s) of material selected from the group which consists of silicon and a silicon compound while contacting aqueous ink, silver atom precipitation can be suppressed. An ink jet recording method can be provided. Moreover, according to this invention, the inkjet recording device used for the said inkjet recording method can be provided.

2A and 2B are schematic views illustrating an example of an ink jet recording apparatus used in the ink jet recording method of the present invention, in which FIG. 1A is a perspective view of a main part of the ink jet recording apparatus, and FIG. FIG. 3 is a schematic diagram showing a part of the recording head in a broken state.

  Hereinafter, embodiments of the present invention will be described in detail. In the present invention, the water-based ink is hereinafter sometimes referred to as “ink”. A member made of at least one material selected from the group consisting of silicon and silicon compounds may be referred to as a “silicon member”. Various physical property values are values at a temperature of 25 ° C. unless otherwise specified. References to “(meth) acrylic acid” and “(meth) acrylate” represent “acrylic acid, methacrylic acid” and “acrylate, methacrylate”, respectively.

  As a result of the study by the present inventors, when using an ink jet recording apparatus comprising a member made of at least one material selected from the group consisting of silicon and a silicon compound while being in contact with an aqueous ink, silver atoms are deposited. It turns out that it cannot be suppressed. In particular, it has been found that when water-based ink contacts a silicon member for a long period of time or in a high temperature environment, silver atoms (Ag) are deposited around the silicon member. The inventors presume the reason as follows.

In the ink, the silver particles tend to become silver oxide due to their surface bonding with oxygen in the ink. Therefore, the silver particles in the ink exist in a state of silver atoms (Ag) and silver oxide (Ag ₂ O). In the ink, as shown by the following formulas (5) and (6), some of the silver atoms (Ag) and silver oxide (Ag ₂ O) are ionized, and the silver atoms (Ag) and oxidation that are not ionized There is an equilibrium between silver (Ag ₂ O) and silver ions (Ag ⁺ ) generated by ionization.

Ink-jet water-based inks are usually alkaline and have a certain amount of hydroxide ions (OH ⁻ ). When a silicon member is used as a member in contact with the aqueous ink, silicon on the surface of the member in contact with the aqueous ink is combined with hydroxide ions (OH ⁻ ) present in the ink, and then —Si—Si— Easy to become OH. Furthermore, expression hydroxide ions ionized from silver oxide _(Ag 2 O) in (6) (OH ^-) or hydroxide ions are present in the ink (OH ^-), the silicon hydroxide ion Pulled by (OH ⁻ ), the bond between silicon and silicon is weakened. Therefore, as shown by the following formula (7), silicon reacts with hydroxide ions (OH ⁻ ) to become silicic acid (Si (OH) ₄ ) and is eluted in the ink. In particular, when the ink comes into contact with the silicon member for a long time, the elution of silicon into the ink is promoted. In addition, since the reaction between silicon and hydroxide ions is promoted in a high temperature environment, the dissolution of silicon into the ink is promoted more than in an environment at a temperature of 25 ° C. With the elution of silicon, a large number of electrons (e ⁻ ) are generated around the silicon member. When there are many electrons, the equilibrium of formula (5) is biased to the left, and silver ions (Ag ⁺ ) existing at a certain ratio in the ink become silver atoms (Ag), so silver atoms are likely to precipitate in the ink. . Although the deposited silver atoms are initially small, the precipitated silver atoms merge to form a large precipitate. Furthermore, silver particles contained in the ink also tend to become larger precipitates by fusing with the precipitated silver atoms. Such a large precipitate clogs the discharge port, making it difficult for ink to be discharged, and ink discharge stability cannot be obtained.

Note that when the ink is acidic to neutral, hydroxide ions (OH ⁻ ) are likely to be generated due to the equilibrium of the formula (6) being biased to the right. Thereby, silicon is easily eluted into the ink, and a large number of electrons (e ⁻ ) are generated around the silicon member as the silicon is eluted. When there are a lot of electrons, the equilibrium of formula (5) tends to be biased to the left, so that silver atoms (Ag) are deposited around the silicon member.

  Therefore, the present inventors examined the composition of the ink for suppressing the precipitation of silver atoms. As a result, it has been found that precipitation of silver atoms can be suppressed by further adding a compound to the ink containing silver particles. The compound includes a compound represented by the general formula (1), a compound having a structure represented by the general formula (2), a compound represented by the general formula (3), and a compound represented by the general formula (4). At least one compound selected from the group consisting of The present inventors presume the reason as follows.

  (Compound represented by the general formula (1))

(In the general formula (1), R ₁₁ and R ₁₂ are each independently an alkyl group, a hydroxyalkyl group, or a hydroxy group, except when R ₁₁ and R ₁₂ are both hydroxy groups. .)

Since the compound represented by the general formula (1) has a sulfonyl group (—S (═O) ₂ ), a hydroxy group (..., Bonded to an oxygen atom of the sulfonyl group and silicon on the surface of the silicon member. The hydrogen atom of Si-Si-OH) is easy to hydrogen bond. As a result, the compound represented by the general formula (1) adheres to the surface of the silicon member in contact with the water-based ink, so that hydroxide ions (OH ⁻ ) present in the ink are deposited on the surface of the silicon member. It is difficult to approach and the reaction of formula (7) does not occur easily. Thereby, the elution of silicon into the ink and the generation of electrons are suppressed, so that the equilibrium of formula (5) is not easily biased to the left, and the precipitation of silver atoms (Ag) is suppressed.

In addition, since the sulfur atom (S) of the sulfonyl group (—S (═O) ₂ ) of the compound represented by the general formula (1) is an electron donor, the silver atom (Ag) in the silver particle and Easy to couple via electron pairs. Therefore, when the compound approaches the silver particle, the sulfur atom (S) in the compound and the silver atom (Ag) in the silver particle are bonded to cover the silver particle with the compound. This makes it difficult for water molecules to approach the silver particles, so that the equilibrium of equation (6) is less likely to be biased to the right, and hydroxide ions (OH ⁻ ) are less likely to occur. For this reason, the reaction of the formula (7) hardly occurs. Thereby, the elution of silicon into the ink and the generation of electrons are suppressed, so that the equilibrium of formula (5) is not easily biased to the left, and the precipitation of silver atoms (Ag) is suppressed.

  Furthermore, since silver particles are covered with a compound, the silver particles are less likely to fuse with the precipitated silver atoms, and the precipitates are less likely to become larger. For this reason, precipitation of silver atoms can be suppressed by incorporating the compound represented by the general formula (1) into the ink.

  (Compound having a structure represented by the general formula (2))

(In General Formula (2), R ₂₁ , R ₂₂ , R ₂₃ , and R ₂₄ are each independently a hydrogen atom, an alkyl group, a hydroxyalkyl group, a carboxyalkyl group, or a sulfonic acid group. The compound having the structure represented by 2) is a monosaccharide or a compound having 2 or more sugars, and in the case of a compound having 2 or more sugars, the 1st carbon and the 2nd, 3rd or 4th carbon Is a compound in which a monosaccharide and a monosaccharide are linked by a single bond.

Since the compound having the structure represented by the general formula (2) has a hydroxy group, the hydroxy group of the compound and the hydroxy group (...- Si-Si-OH) bonded to silicon on the surface of the silicon member. And dehydration condensation. As a result, the compound having the structure represented by the general formula (2) adheres to the surface of the silicon member in contact with the water-based ink, so that hydroxide ions (OH ⁻ ) present in the ink are It is difficult to approach the surface, and the reaction of formula (7) does not occur easily. Thereby, the elution of silicon into the ink and the generation of electrons are suppressed, so that the equilibrium of formula (5) is not easily biased to the left, and the precipitation of silver atoms (Ag) is suppressed.

  (Compound represented by the general formula (3))

(In General Formula (3), M is a hydrogen atom, an alkali metal, ammonium, or organic ammonium. R ₃₁ and R ₃₂ are each independently a hydrogen atom, an alkyl group, a hydroxyalkyl group, or a carboxyalkyl. Group.)

Since the compound represented by the general formula (3) has a hydroxy group, it is between the hydroxy group of the compound and the hydroxy group (...- Si-Si-OH) bonded to silicon on the surface of the silicon member. Dehydrate and condense. As a result, the compound represented by the general formula (3) adheres to the surface of the silicon member in contact with the water-based ink, so that hydroxide ions (OH ⁻ ) existing in the ink approach the surface of the silicon member. It is difficult and reaction of Formula (7) does not occur easily. Thereby, the elution of silicon into the ink and the generation of electrons are suppressed, so that the equilibrium of formula (5) is not easily biased to the left, and the precipitation of silver atoms (Ag) is suppressed.

  (Compound represented by the general formula (4))

(In General Formula (4), A is a nitrogen atom or a phosphorus atom. R ₄₁ , R ₄₂ , R ₄₃ , and R ₄₄ are each independently an alkyl group, a hydroxyalkyl group, or a carboxyalkyl group. is there.)

Since the compound represented by the general formula (4) has a positive charge, it is attracted to an oxygen atom of a hydroxy group (...- Si-Si-OH) bonded to silicon on the surface of the silicon member, and hydrogen Instead of atoms, cations are bonded to oxygen atoms. As a result, the compound represented by the general formula (4) adheres to the surface of the silicon member in contact with the water-based ink, so that hydroxide ions (OH ⁻ ) present in the ink are deposited on the surface of the silicon member. It is difficult to approach and the reaction of formula (7) does not occur easily. Thereby, the elution of silicon into the ink and the generation of electrons are suppressed, so that the equilibrium of formula (5) is not easily biased to the left, and the precipitation of silver atoms (Ag) is suppressed.

  The ink jet recording method of the present invention uses an ink jet recording apparatus provided with a member made of at least one material selected from the group consisting of silicon and silicon compounds while being in contact with an aqueous ink. Examples of the member made of at least one material selected from the group consisting of silicon and a silicon compound in contact with the aqueous ink include an ink flow path forming member of a recording head. Hereinafter, the case where the ink flow path forming member of the recording head is a member made of at least one material selected from the group consisting of silicon and silicon compounds will be described as an example.

  1A and 1B are diagrams schematically showing an example of an ink jet recording apparatus used in the ink jet recording method of the present invention. FIG. 1A is a perspective view of a main part of the ink jet recording apparatus, and FIG. 1B is a perspective view of a recording head. It is. The ink jet recording apparatus is provided with a conveying means (not shown) for conveying the recording medium 32 and a carriage shaft 34. A recording head 36 can be mounted on the carriage shaft 34. The recording head 36 has a configuration in which a recording element substrate 38 and an ink storage unit 40 are integrated. While the recording head 36 is conveyed along the carriage shaft 34 in the main scanning direction, ink (not shown) is ejected from the recording head 36 toward the recording medium 32. Then, the recording medium 32 is conveyed in the sub-scanning direction by a conveying unit (not shown), whereby an image is recorded on the recording medium 32.

  FIG. 2 is a schematic diagram showing a part of the recording head broken away. On the upper surface of the silicon substrate 101, an electrothermal conversion element 102 and a drive circuit (not shown) are arranged. As a material for the silicon substrate, silicon, silicon compounds (silicon oxide, silicon nitride, silicon carbide, etc.), and the like can be used. In the silicon substrate 101, a discharge port 103 is opened at a position corresponding to the electrothermal conversion element 102, and the discharge port 103 communicates with the ink supply port 104. In the ink flow path including the ink supply port 104 and the ejection port 103, at least one material selected from the group consisting of silicon and silicon compounds is used.

  The inkjet recording method of the present invention is a method of recording an image on a recording medium by discharging from an inkjet recording head. Examples of the ejection method include a method of imparting mechanical energy to the ink and a method of imparting thermal energy to the ink. In the present invention, it is particularly preferable to employ a method in which thermal energy is applied to the ink and the ink is ejected. Other than using the ink of the present invention, the steps of the ink jet recording method may be known.

<Ink>
The ink is composed of silver particles, a compound represented by the general formula (1), a compound having a structure represented by the general formula (2), a compound represented by the general formula (3), and the general formula (4). Containing at least one compound selected from the group consisting of the compounds represented.

(Silver particles)
Silver particles are composed of silver atoms. The silver particles may contain other metal atoms, oxygen atoms, sulfur atoms, carbon atoms and the like in addition to silver atoms, but the ratio (%) of silver atoms in the silver particles is 50. It is preferably 0% by mass or more.

  As a method for producing silver particles, for example, a method of pulverizing a lump of silver with a pulverizer such as a ball mill or a jet mill (a pulverization method), a method of reducing silver ions or a silver complex with a reducing agent to agglomerate (a reduction method) Etc. In the present invention, the silver particles are preferably produced by a reduction method from the viewpoint of easy control of the particle size of the silver particles and the dispersion stability of the silver particles.

[Cumulative 50% particle size of silver particles (D ₅₀ )]
The cumulative 50% particle size of silver particles based on the volume is the particle diameter when 50% is accumulated from the small particle size side based on the total volume of silver particles measured in the particle size integration curve. It is. The volume-based cumulative 50% particle size (nm) of the silver particles is preferably 150 nm or less. Since the width of the curve of the particle size integration curve of silver particles is wide, silver particles having a large particle size are included. _However, if the _{D 50} and 150nm or less, the ratio of the silver particles of larger particle size greater than 200nm is reduced, a large silver particles hardly exist in particle size. When D ₅₀ is at 150nm or less, the particle diameter of the silver particles is smaller, even if more silver deposit ink is prolonged contact to silicon element is less likely to large precipitates. Thereby, the storage stability of the ink is further improved. The volume-based cumulative 50% particle size (nm) of silver particles is more preferably 1 nm or more and 150 nm or less, and further preferably 10 nm or more and 100 nm or less. D ₅₀ is measured by a dynamic light scattering method.

[Method of dispersing silver particles]
Examples of a method for dispersing silver particles include a surfactant dispersion type using a surfactant as a dispersant and a resin dispersion type using a resin as a dispersant. Of course, in the ink, silver particles having different dispersion methods can be used in combination.

  As the surfactant used as a dispersant in the surfactant dispersion type, an anionic surfactant, a nonionic surfactant, a cationic surfactant, an amphoteric surfactant, and the like can be used. Anionic surfactants include fatty acid salts, alkyl sulfate esters, alkyl aryl sulfonates, alkyl diaryl ether disulfonates, dialkyl sulfosuccinates, alkyl phosphates, naphthalene sulfonic acid formalin condensates, polyoxyethylene alkyls. Examples thereof include ether sulfate, polyoxyethylene alkyl phosphate ester salt, glycerol borate fatty acid ester and the like. Nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethyleneoxypropylene block copolymers, sorbitan fatty acid esters, glycerin fatty acid esters, polyoxyethylene fatty acid esters, polyoxyethylene alkylamines, fluorine compounds, silicone compounds, etc. Is mentioned. Examples of the cationic surfactant include alkylamine salts, quaternary ammonium salts, alkylpyridinium salts, alkylimidazolium salts, and the like. Examples of amphoteric surfactants include alkylamine oxide and phosphadylcholine.

The resin used as a dispersant in the resin dispersion type preferably has both a hydrophilic part and a hydrophobic part. As resins, polyvinyl resins, polyester resins, amino resins, acrylic resins, epoxy resins, polyurethane resins, polyether resins, polyamide resins, unsaturated polyester resins, phenol resins, silicone resins And fluorine-based polymer compounds. Thus, by using a surfactant or a resin, silver particles can be stably dispersed and hardly precipitated. Furthermore, the resin is preferably nonionic. When the resin is anionic, it has alkali metal ions such as sodium ions as counter ions. Alkali metal ions pull silicon into the ink by repeatedly bonding to and leaving oxygen atoms of hydroxy groups (...- Si-Si-OH) bonded to silicon on the surface of the silicon member, Promotes elution of silicon into the ink. Along with this, a large number of electrons are also generated, which promotes the precipitation of silver atoms.
The polystyrene-converted weight average molecular weight (Mw) obtained by gel permeation chromatography (GPC) of the resin is preferably 1,000 or more and 100,000 or less, and preferably 3,000 or more and 50,000 or less. Further preferred.

  The ink preferably further contains at least one of a surfactant and a nonionic resin. The content (mass%) of the surfactant and nonionic resin in the ink is a mass ratio (times) to the content (mass%) of the silver particles, and is 0.02 times or more and 3.00 times or less. Preferably there is. The content (mass%) of the surfactant and the nonionic resin in the ink is the sum of the surfactant and the nonionic resin when the ink contains both the surfactant and the nonionic resin. It is the content of. When the ratio is less than 0.02 times, the amount of the dispersant is too small with respect to the silver particles, so that the silver particles are hardly covered with the dispersant. Therefore, the precipitated silver atoms and silver particles are fused, and the precipitate is likely to be large. Accordingly, when the ink contacts the silicon member for a long time, the precipitation of silver atoms may not be sufficiently suppressed. When the ratio exceeds 3.00 times, the amount of the dispersing agent is too much for the silver particles, so that the silver particles are hardly fused. Thereby, the glossiness of the image may not be sufficiently obtained.

  The content (% by mass) of silver particles in the ink is preferably 2.0% by mass or more and 15.0% by mass or less based on the total mass of the ink. When the content is less than 2.0% by mass, there are too few silver particles, so that it is difficult to form a silver film on the recording medium, and the glossiness of the image may not be sufficiently obtained. When the content exceeds 15.0% by mass, there are too many silver particles, so when the recording head has a heat generating part for ejecting ink, the silver particles easily adhere to the heat generating part, and the foaming energy applied to the ink And the ink ejection stability may not be sufficiently obtained. The content (% by mass) of silver particles in the ink is more preferably 2.0% by mass or more and 8.0% by mass or less based on the total mass of the ink.

(Compound)
The ink includes a compound represented by the general formula (1), a compound having a structure represented by the general formula (2), a compound represented by the general formula (3), and a compound represented by the general formula (4). At least one compound selected from the group consisting of: First, groups (alkyl group, hydroxyalkyl group, and carboxyalkyl group) possessed by the compound will be described.

  The alkyl group is preferably a linear or branched alkyl group having 1 to 10 carbon atoms. Specifically, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, sec-butyl group, pentyl group, neopentyl group, hexyl group, isohexyl group, 3-methylpentyl group Etc. The hydroxyalkyl group is a group in which a hydrogen atom of the above-described alkyl group is substituted with a hydroxy group. The carboxyalkyl group is a group in which the hydrogen atom of the above-described alkyl group is substituted with a carboxy group.

  [Compound represented by general formula (1)]

(In the general formula (1), R ₁₁ and R ₁₂ are each independently an alkyl group, a hydroxyalkyl group, or a hydroxy group, except when R ₁₁ and R ₁₂ are both hydroxy groups. .)

  The alkyl group is preferably a linear or branched alkyl group having 1 to 3 carbon atoms, and more preferably at least one selected from the group consisting of a methyl group and an isopropyl group. The hydroxyalkyl group is preferably a linear hydroxyalkyl group having 1 to 3 carbon atoms. When the compound represented by the general formula (1) having a hydroxyalkyl group is bonded to the silver particles, the silver particles are easily dispersed in the ink because the hydroxyalkyl group is hydrophilic. For this reason, the precipitated silver atoms and silver particles are less likely to fuse, and the precipitate is less likely to become larger. Of these, bis (2-hydroxyalkyl) sulfones having two hydroxyalkyl groups are preferable, and bis (2-hydroxyethyl) sulfone is more preferable.

  However, when the group replacing the hydrogen atom of the alkyl group is not a hydroxy group but a carboxy group, a cyano group, an isocyanate group, an amino group, a thiol group, or a group having a disulfide bond, the precipitation of silver atoms cannot be suppressed. Further, although different from the structure of the compound represented by the general formula (1), a compound containing a cyanate group and a sulfur atom, which are also mentioned in the above functional group, like silver thiocyanate, is similarly silver atom. Cannot be suppressed. The reason is presumed as follows. The silver particles are bonded to the sulfur atom of the compound represented by the general formula (1). If the compound further has a functional group having a high affinity with the above-mentioned silver atom, the silver containing the silver atom also in the functional group. Particles are bound. Thus, when the compound having the above-described functional group is used, the silver particles are bonded at two sites of the sulfur atom and the above-described functional group, so that the aggregation of the silver particles around the silicon member is promoted. Thereby, precipitation of silver atoms cannot be suppressed.

  The content (mass%) of the compound represented by the general formula (1) in the water-based ink is a mass ratio (times) to the silver particle content (mass%), and is 0.3 times or more and 4.5 times or less. It is preferable that If the ratio is less than 0.3 times, the amount of the compound adhering to the silver particles is too small, and it is difficult to suppress the elution of silicon into the ink and the generation of electrons. Therefore, the precipitation of silver atoms may not be sufficiently suppressed. When the ratio exceeds 4.5 times, the amount of the compound is too large with respect to the silver particles, so that the silver particles are covered with the compound and the silver particles are difficult to fuse. Thereby, the glossiness of the image may not be sufficiently obtained.

  The content (% by mass) of the compound represented by the general formula (1) in the ink is preferably 30.0% by mass or less. When the content exceeds 30.0% by mass, the amount of the compound is too large, so that the silver particles are covered with the compound, and the silver particles are hardly fused. Thereby, the glossiness of the image may not be sufficiently obtained. The content is more preferably 1.50% by mass or more.

  [Compound having the structure represented by the general formula (2)]

(In General Formula (2), R ₂₁ , R ₂₂ , R ₂₃ , and R ₂₄ are each independently a hydrogen atom, an alkyl group, a hydroxyalkyl group, a carboxyalkyl group, or a sulfonic acid group. The compound having the structure represented by 2) is a monosaccharide or a compound having 2 or more sugars, and in the case of a compound having 2 or more sugars, the 1st carbon and the 2nd, 3rd or 4th carbon Is a compound in which a monosaccharide and a monosaccharide are linked by a single bond.

The upper and lower positional relationship between OR ₂₁ , OR ₂₂ , OR ₂₃ , CH ₂ OR ₂₄ and a hydrogen atom (not shown) at the counter electrode across the carbon atom to which these groups are bonded is not limited. It may also be an enantiomer. When R ₂₂ or R ₂₄ is a hydrogen atom, a hydroxyalkyl group, or a carboxyalkyl group, both may be dehydrated and condensed in the molecule. Furthermore, the compound having the structure represented by the general formula (2) is a monosaccharide or a compound having two or more sugars. In the case of a compound having two or more sugars, the carbon at the 1-position and the carbon at the 2-, 3-, or 4-position are bonded and polymerized, and the monosaccharide and the monosaccharide are linked by a single bond. Here, the carbon at the 1st position is a carbon bonded to OH in the general formula (2), and the carbon at the 2nd position is a carbon bonded to OR ₂₃ in the general formula (2). That is. Further, the carbon at the 3rd position is the carbon bonded to OR ₂₂ in the general formula (2), and the carbon at the 4th position is the carbon bonded to OR ₂₁ in the general formula (2). That is.

  Especially, it is preferable that the compound which has a structure represented by General formula (2) has a some hydroxy group. When the compound is bonded to the silver particles via the hydroxy group, the compound covers the silver particles, and the silver particles and the precipitated silver particles are hardly fused, so that it is difficult to form a large precipitate. Thereby, precipitation of a silver atom can be suppressed effectively. The compound having the structure represented by the general formula (2) is a linear or branched polymer compound in which the 1st carbon and the 2nd, 3rd, or 4th carbon are bonded and polymerized. Of these, carboxyalkyl celluloses are more preferable. Since the polymer compound is three-dimensionally large, the compound easily covers the silver particles, and it is difficult to form a large precipitate by making it difficult to fuse the silver particles with the precipitated silver particles. Thereby, precipitation of a silver atom can be suppressed effectively. Especially, it is preferable that carboxyalkyl cellulose is carboxymethylcellulose.

The content (mass%) of the compound having the structure represented by the general formula (2) in the water-based ink is a mass ratio (times) to the silver particle content (mass%), and is 0.2 times or less. Preferably there is. The ratio is more preferably 0.05 times or more. The content (% by mass) of the compound having the structure represented by the general formula (2) in the ink is preferably 1.0% by mass or less. When the content exceeds 1.0% by mass, when part or all of R ₂₁ , R ₂₂ , R ₂₃ , and R ₂₄ is a carboxyalkyl group, a carboxy group having a high affinity for silver atoms, The compound and the plurality of silver particles are combined. Thereby, aggregation of silver particles is promoted around the silicon member, and precipitation of silver atoms may not be sufficiently suppressed. The content is more preferably 0.1% by mass or more.

  The compound having the structure represented by the general formula (2) is preferably not a salt form. When having an alkali metal ion such as sodium ion as a salt, the alkali metal ion binds to or separates from an oxygen atom of a hydroxy group (...- Si-Si-OH) bonded to silicon on the surface of the silicon member. Repeat. This pulls the silicon and promotes the elution of silicon into the ink. Along with this, a large number of electrons are also generated, so that the precipitation of silver atoms is promoted, and the precipitation of silver atoms may not be sufficiently suppressed. Examples of the salt form of the compound having the structure represented by the general formula (2) include sodium carboxymethyl cellulose. The salt form content (% by mass) of the compound having the structure represented by the general formula (2) in the ink is preferably 0.1% by mass or less, and more preferably 0.0% by mass. preferable.

  [Compound represented by formula (3)]

(In General Formula (3), M is a hydrogen atom, an alkali metal, ammonium, or organic ammonium. R ₃₁ and R ₃₂ are each independently a hydrogen atom, an alkyl group, a hydroxyalkyl group, or a carboxyalkyl. Group.)
The carboxyalkyl group is preferably a carboxyalkyl group having 1 to 3 carbon atoms.

  The compound represented by the general formula (3) preferably has a plurality of hydroxy groups. When the compound is bonded to the silver particles via the hydroxy group, the compound covers the silver particles, and the silver particles and the precipitated silver particles are hardly fused, so that it is difficult to form a large precipitate. Thereby, precipitation of a silver atom can be suppressed effectively.

  When the compound represented by the general formula (3) has a plurality of carboxy groups such as citric acid, it forms a complex with silver ions, so that the equilibrium is not easily biased to the left in the formula (5), and silver particles are precipitated. Can be suppressed.

The content (% by mass) of the compound represented by the general formula (3) in the water-based ink is a mass ratio (times) to the content (% by mass) of the silver particles, and is 0.3 to 1.0 times. The following is preferable. The content (% by mass) of the compound represented by the general formula (3) in the ink is preferably 5.0% by mass or less. When the content exceeds 5.0% by mass, when a part or all of R ₃₁ and R ₃₂ is a carboxyalkyl group, a compound and a plurality of silver particles are formed by a carboxy group having a high affinity for silver atoms. And promotes the aggregation of silver particles around the silicon member. Thereby, the precipitation of silver atoms may not be sufficiently suppressed. The content is preferably 0.1% by mass or more.

  In general formula (3), M is preferably a hydrogen atom. When M is an alkali metal, ammonium, or organic ammonium, the compound represented by the general formula (3) is in a salt form. For the same reason as in the case of the salt form of the compound having the structure represented by the general formula (2), precipitation of silver atoms may not be sufficiently suppressed. The salt form content (% by mass) of the compound represented by the general formula (3) in the ink is preferably 0.1% by mass or less, and more preferably 0.0% by mass.

  [Compound represented by the general formula (4)]

(In General Formula (4), A is a nitrogen atom or a phosphorus atom. R ₄₁ , R ₄₂ , R ₄₃ , and R ₄₄ are each independently an alkyl group, a hydroxyalkyl group, or a carboxyalkyl group. is there.)

When A is a nitrogen atom, it is preferable that _R41 , _R42 , _R43 , and _R44 are each independently an alkyl group or a carboxyalkyl group. When A is a phosphorus atom, R ₄₁ , R ₄₂ , R ₄₃ , and R ₄₄ are preferably each independently an alkyl group.

  The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, and the hydroxyalkyl group is preferably a hydroxyalkyl group having 1 to 2 carbon atoms.

  The content (% by mass) of the compound represented by the general formula (4) in the water-based ink is a mass ratio (times) to the content (% by mass) of the silver particles, and is 0.1 to 1.0 times. The following is preferable. The content (% by mass) of the compound represented by the general formula (4) in the ink is preferably 0.2% by mass or more and 2.0% by mass or less.

  In particular, the ink is at least selected from the group consisting of a compound represented by the general formula (1), a compound having a structure represented by the general formula (2), and a compound represented by the general formula (3). It is preferable to contain one compound.

(Aqueous medium)
The ink contains water or an aqueous medium that is a mixed solvent of water and a water-soluble organic solvent. It is preferable to use deionized water (ion exchange water) as water. As the water-soluble organic solvent, a water-soluble organic solvent (other water-soluble organic solvents) other than the compound represented by the general formula (1) can be used in combination. Other water-soluble organic solvents are not particularly limited, and any of those usable for ink-jet inks such as alcohols, glycols, glycol ethers, and nitrogen-containing compounds can be used. One or more of these water-soluble organic solvents can be contained in the ink. The content (% by mass) of water in the ink is preferably 50.0% by mass or more and 95.0% by mass or less based on the total mass of the ink. The content (% by mass) of the water-soluble organic solvent in the ink is preferably 3.0% by mass or more and 50.0% by mass or less based on the total mass of the ink. When the content of the water-soluble organic solvent is less than 3.0% by mass, reliability such as anti-sticking property may not be sufficiently obtained when the ink is used in an ink jet recording apparatus. Further, when the content of the water-soluble organic solvent is more than 50.0% by mass, the viscosity of the ink is increased and ink supply failure may occur.

(Other ingredients)
In addition to the above components, the ink may contain a water-soluble organic compound that is solid at 25 ° C., such as urea and its derivatives, trimethylolpropane, and trimethylolethane. In addition, various additives such as pH adjusters, antifoaming agents, rust preventives, antiseptics, antifungal agents, antioxidants, anti-reducing agents, and chelating agents may be added to the ink of the present invention as necessary. May be included.

(Ink physical properties)
The viscosity (mPa · s) at 25 ° C. of the ink is preferably 1 mPa · s to 5 mPa · s, and more preferably 1 mPa · s to 3 mPa · s. The surface tension (mN / m) at 25 ° C. of the ink is preferably 10 mN / m or more and 60 mN / m or less, more preferably 20 mN / m or more and 60 mN / m or less, and more preferably 30 mN / m or more. More preferably, it is 40 mN / m or less.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated further in detail, this invention is not limited at all by the following Example, unless the summary is exceeded. In addition, what is described as “parts” and “%” with respect to the component amounts is based on mass unless otherwise specified.

<Preparation of liquid containing silver particles>
(Liquid containing silver particles 1)
To 500 mL of an aqueous solution containing 0.25 mol / L iron (II) sulfate heptahydrate (manufactured by Wako Pure Chemical Industries) and 0.50 mol / L trisodium citrate dihydrate (manufactured by Wako Pure Chemical Industries) 100 mL of 0.83 mol / L silver nitrate aqueous solution (manufactured by Wako Pure Chemical Industries, Ltd.) was added over 3 seconds. The solution was stirred at 300 rpm for 30 seconds at a temperature of 20 ° C. The obtained solution was centrifuged at 3,000 rpm, and the collected solid content was dispersed in water to obtain a liquid containing silver particles 1 (the content of silver particles 1 was 40.0%). At that time, trisodium citrate dihydrate used as a reducing agent was completely removed. The D _{50 of the} silver particles 1 was measured using a particle size distribution meter (DLS-6500, manufactured by Otsuka Electronics Co., Ltd.) by a dynamic light scattering method. The measurement conditions are Setzero: 30 s, number of measurements: 3, measurement time: 180 seconds, shape: true sphere, and refractive index: 1.59. The D _{50 of the} silver particle 1 was 50 nm.

(Liquid containing silver particles 2)
A liquid containing silver particles 2 (content of silver particles 2 was 40.0%) was obtained in the same manner as the liquid containing silver particles 1 except that the stirring speed was changed. The D _{50 of the} silver particles 2 was 150 nm.

(Liquid containing silver particles 3)
A liquid containing silver particles 2 (content of silver particles 3 was 40.0%) was obtained in the same manner as the liquid containing silver particles 1 except that the stirring speed was changed. The D _{50 of the} silver particles 3 was 200 nm.

<Preparation of silver particle dispersion>
According to the description of the preparation method of Example 2-2 of JP-A-2004-285106, a silver particle dispersion (silver particle content is 40.0%, surfactant content is 4.0%) Got. _{D 50} of the silver particles was 40nm.

<Preparation of liquid containing water-soluble resin>
A styrene-ethyl acrylate-acrylic acid copolymer produced by a conventional method is neutralized with an aqueous potassium hydroxide solution in an equimolar amount with respect to the acid value of the copolymer, and the resin content is 20.0%. A liquid containing a water-soluble resin was prepared. Styrene-ethyl acrylate-acrylic acid copolymer is an anionic resin.

<Preparation of ink>
After mixing each component described in Tables 1 and 2 and stirring sufficiently, pressure filtration was performed with a filter having a pore size of 1.2 μm to obtain an ink. BYK-356, BYK-154, and DISPERBYK-190 are nonionic resins manufactured by Big Chemie.

<Evaluation>
In the present invention, according to the following evaluation criteria, AA, A, or B is an acceptable level, and C is an unacceptable level. The evaluation results are shown in Table 3.

(Suppression of silver atom precipitation)
The ink obtained above was filled in an ink cartridge and set in the recording head shown in FIG. Several hours after setting on the recording head, it was confirmed that the ink flow path formed of the silicon member was filled with ink. The recording head in which the ink flow path was filled with ink was sealed with a sealing material, sealed in a blister pack, and left in a constant temperature bath at a temperature of 60 ° C. for 1 month and 2 months. Then, the blister pack was taken out from the thermostat and returned to room temperature.

The ink flow paths of the recording head left for one month and the recording head left for two months were observed with an optical microscope and an electron microscope to confirm the presence or absence of silver atom precipitates. Evaluation was performed according to the following evaluation criteria.
AA: No precipitate was observed using either an optical microscope or an electron microscope. A: No precipitate was observed using an optical microscope, but nano-sized precipitates were observed using an electron microscope. B: Micron-sized precipitates were observed on a part of the recording element substrate when an optical microscope was used. C: Micron-sized precipitates were observed on the entire recording element substrate when an optical microscope was used.

(Glossiness of the image)
The ink obtained above was filled in the ink flow path of the recording head of the ink jet recording apparatus (PIXUS iP8600, manufactured by Canon). In this embodiment, it is defined that an image recorded under a condition in which 8 droplets of 2.5 pL per droplet are applied to a 1/600 inch × 1/600 inch unit region has a recording duty of 100%. Using the inkjet recording apparatus, the ink shown in Table 3 was applied to glossy paper (Canon Photo Paper / Glossy Pro [Platinum Grade]; manufactured by Canon), and a solid image having a recording duty of 100% was recorded. After the obtained image was naturally dried for 24 hours, the 20-degree specular gloss based on JIS Z 8741 was measured using a gloss meter (VG 7000, manufactured by Nippon Denshoku Industries Co., Ltd.). Evaluation was performed according to the following evaluation criteria. AA: Glossiness was 500 or more A: Glossiness was less than 500

Claims (18)

An ink jet recording method using an ink jet recording apparatus comprising a water-based ink and a member made of at least one material selected from the group consisting of silicon and a silicon compound while being in contact with the water-based ink,
The water-based ink contains silver particles, a compound represented by the following general formula (1), a compound having a structure represented by the following general formula (2), a compound represented by the following general formula (3), and the following An inkjet recording method comprising at least one compound selected from the group consisting of compounds represented by formula (4).

(In the general formula (1), R ₁₁ and R ₁₂ are each independently an alkyl group, a hydroxyalkyl group, or a hydroxy group, except when R ₁₁ and R ₁₂ are both hydroxy groups. .)

(In General Formula (2), R ₂₁ , R ₂₂ , R ₂₃ , and R ₂₄ are each independently a hydrogen atom, an alkyl group, a hydroxyalkyl group, a carboxyalkyl group, or a sulfonic acid group. The compound having the structure represented by 2) is a monosaccharide or a compound having 2 or more sugars, and in the case of a compound having 2 or more sugars, the 1st carbon and the 2nd, 3rd or 4th carbon Is a compound in which a monosaccharide and a monosaccharide are linked by a single bond.

(In General Formula (3), M is a hydrogen atom, an alkali metal, ammonium, or organic ammonium. R ₃₁ and R ₃₂ are each independently a hydrogen atom, an alkyl group, a hydroxyalkyl group, or a carboxyalkyl. Group.)

(In General Formula (4), A is a nitrogen atom or a phosphorus atom. R ₄₁ , R ₄₂ , R ₄₃ , and R ₄₄ are each independently an alkyl group, a hydroxyalkyl group, or a carboxyalkyl group. is there.)   The inkjet recording method according to claim 1, wherein a volume-based cumulative 50% particle size (nm) of the silver particles is 150 nm or less.   The water-based ink is selected from the group consisting of a compound represented by the general formula (1), a compound having a structure represented by the general formula (2), and a compound represented by the general formula (3). The inkjet recording method according to claim 1, comprising at least one compound.   The inkjet recording method according to claim 1, wherein the water-based ink contains a compound represented by the general formula (1).   The content (mass%) of the compound represented by the general formula (1) in the water-based ink is 0.3 times or more in mass ratio (times) to the content (mass%) of the silver particles. The inkjet recording method according to claim 4, wherein the inkjet recording method is 5 times or less. The inkjet recording method according to claim 1, wherein R ₁₁ and R ₁₂ in the general formula (1) are hydroxyalkyl groups.   The inkjet recording method according to claim 1, wherein the water-based ink contains a compound having a structure represented by the general formula (2).   The content (% by mass) of the compound having the structure represented by the general formula (2) in the water-based ink is 0.2 times the mass ratio (times) to the content (% by mass) of the silver particles. The inkjet recording method according to claim 7, which is as follows. 9. The method according to claim 1, wherein R ₂₁ , R ₂₂ , and R ₂₃ in the general formula (2) are each independently a hydrogen atom or a carboxyalkyl group. The ink jet recording method described in 1.   The inkjet recording method according to claim 1, wherein the water-based ink contains a compound represented by the general formula (3).   The content (mass%) of the compound represented by the general formula (3) in the water-based ink is 0.3 times or more in mass ratio (times) to the content (mass%) of the silver particles. The inkjet recording method according to claim 10, wherein the inkjet recording method is 1.0 times or less. The inkjet recording method according to any one of claims 1 to 3, 10, and 11, wherein R ₃₁ and R ₃₂ in the general formula (3) are each independently a carboxyalkyl group.   The inkjet recording method according to claim 1, wherein the water-based ink contains a compound represented by the general formula (4).   The content (mass%) of the compound represented by the general formula (4) in the water-based ink is 0.1 times or more in mass ratio (times) to the silver particle content (mass%). The inkjet recording method according to claim 13, wherein the inkjet recording method is 1.0 times or less. The R ₄₁ , the R ₄₂ , the R ₄₃ , and the R ₄₄ in the general formula (4) are each independently an alkyl group or a hydroxyalkyl group. The inkjet recording method according to any one of the above.   The inkjet recording method according to claim 1, wherein the water-based ink further contains at least one of a surfactant and a nonionic resin.   2. The content (mass%) of the surfactant and the nonionic resin in the water-based ink is 0.02 times or more in mass ratio (times) to the content (mass%) of the silver particles. The inkjet recording method according to claim 16, wherein the inkjet recording method is 00 times or less. An ink jet recording apparatus comprising: a water-based ink; and a member made of at least one material selected from the group consisting of silicon and a silicon compound while being in contact with the water-based ink,
The water-based ink contains silver particles, a compound represented by the following general formula (1), a compound having a structure represented by the following general formula (2), a compound represented by the following general formula (3), and the following An inkjet recording apparatus comprising at least one compound selected from the group consisting of compounds represented by formula (4).

(In the general formula (1), R ₁₁ and R ₁₂ are each independently an alkyl group, a hydroxyalkyl group, or a hydroxy group, except when R ₁₁ and R ₁₂ are both hydroxy groups. .)

(In General Formula (2), R ₂₁ , R ₂₂ , R ₂₃ , and R ₂₄ are each independently a hydrogen atom, an alkyl group, a hydroxyalkyl group, a carboxyalkyl group, or a sulfonic acid group. The compound having the structure represented by 2) is a monosaccharide or a compound having 2 or more sugars, and in the case of a compound having 2 or more sugars, the 1st carbon and the 2nd, 3rd or 4th carbon Is a compound in which a monosaccharide and a monosaccharide are linked by a single bond.

(In General Formula (3), M is a hydrogen atom, an alkali metal, ammonium, or organic ammonium. R ₃₁ and R ₃₂ are each independently a hydrogen atom, an alkyl group, a hydroxyalkyl group, or a carboxyalkyl. Group.)

(In General Formula (4), A is a nitrogen atom or a phosphorus atom. R ₄₁ , R ₄₂ , R ₄₃ , and R ₄₄ are each independently an alkyl group, a hydroxyalkyl group, or a carboxyalkyl group. is there.)