JP6669984B2 - Ink jet recording method and ink jet recording apparatus - Google Patents

Description

  The present invention relates to an inkjet recording method and an inkjet recording device.

  The ink jet recording method is capable of recording a high-definition image with a relatively simple device, and is rapidly developing in various fields. Among them, various studies have been made on ejection stability and the like. For example, Patent Literature 1 has an object to provide a reaction liquid for inkjet recording that can be continuously discharged. One of the objects is to provide a reaction liquid for inkjet recording that is used together with a color pigment ink and generates a reaction when contacted with the color pigment ink. A reaction liquid for inkjet recording, which is a liquid and contains (a) a polyvalent metal salt, (b) maleic acid, and (c) a liquid medium is disclosed.

JP 2009-137056 A

  However, Patent Literature 1 does not describe at all that foreign matter is generated due to interaction between a reaction liquid and members of an ink jet recording apparatus, which causes ejection failure. The reaction solution containing the polyvalent metal salt elutes components contained in the members of the inkjet recording apparatus that come into contact with the reaction solution. When such components elute into the reaction solution, foreign substances are generated, which leads to ejection failure. Further, when a monovalent metal salt is used, there is a problem that the image quality of the obtained recorded matter is deteriorated.

  The present invention has been made to solve at least a part of the problems described above, and an object of the present invention is to provide a reaction liquid having excellent ejection properties and excellent image quality of a recorded matter to be obtained.

  The present inventors have conducted intensive studies to solve the above problems. As a result, the inventors have found that an inkjet recording method using a predetermined reaction liquid and a predetermined recording apparatus can solve the above-described problems, and have completed the present invention.

That is, the present invention is as follows.
[1]
A reaction liquid container, an inkjet head, and a reaction liquid flow path, which are performed using an inkjet recording apparatus having:
The reaction liquid is sent from the reaction liquid container to the nozzle hole of the inkjet head through the reaction liquid flow path that connects the reaction liquid container to the nozzle hole of the inkjet head, and is supplied from the nozzle hole. A reaction liquid attaching step of ejecting and attaching to a recording medium,
An ink composition including a coloring material, ejected from a nozzle hole of an inkjet head, and an ink composition adhering step of adhering to a recording medium,
The reaction liquid contains a (meth) acrylic resin and a polyvalent metal salt as an aggregating agent that reacts with components of the ink composition (a colorless colorant that is not a pigment dispersant used for dispersing a pigment in an aqueous ink composition) Or those containing white fine particles),
At least a part of the member that comes into contact with the reaction solution among the members constituting the reaction solution container and the reaction solution channel is a member containing a fatty acid having 6 or more carbon atoms,
The (meth) acrylic resin is the pigment dispersant used for dispersing the pigment in the aqueous ink composition, such as polyacrylic acid, acrylic acid-acrylonitrile copolymer, or acrylic acid-acrylic acid ester copolymer. Copolymer, styrene-acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid-acrylate copolymer, vinylnaphthalene-acrylic acid copolymer, acetic acid vinyl - acrylic acid copolymer, or at least one of these salts seen including,
The content of the (meth) acrylic resin is 10 to 35% by mass based on the total amount of the reaction solution.
Ink jet recording method.
[2]
The inkjet recording method according to [1], wherein the fatty acid includes a fatty acid having 6 to 25 carbon atoms.
[3]
The inkjet recording method according to [1] or [2], wherein the (meth) acrylic resin contains a water-soluble resin.
[4]
The inkjet recording method according to any one of [1] to [3], wherein the reaction liquid contains water.
[5]
The inkjet recording method according to any one of [1] to [4], wherein the content of the (meth) acrylic resin is 10 to 30 % by mass based on the total amount of the reaction solution.
[6]
The inkjet recording method according to [5] , wherein the content of the (meth) acrylic resin is 10 to 20 % by mass based on the total amount of the reaction solution.
[7]
The inkjet recording method according to any one of [1] to [6], wherein the content of the polyvalent metal salt is 0.10 to 10% by mass based on the total amount of the reaction solution.
[ 8 ]
The inkjet recording method according to any one of [1] to [ 7 ], wherein the reaction solution container is a pack or a bottle.
[ 9 ]
The inkjet recording method according to any one of [1] to [ 9 ], wherein the inkjet recording apparatus is an off-carriage type serial printer or a line printer.
[ 10 ]
An inkjet recording apparatus that performs recording by the inkjet recording method according to any one of [1] to [ 9 ].

FIG. 1 is a block diagram illustrating an example of a configuration of a recording apparatus that can be used in the present embodiment. FIG. 2 is a perspective view illustrating a recording apparatus according to the embodiment.

  Hereinafter, an embodiment of the present invention (hereinafter, referred to as “the present embodiment”) will be described in detail with reference to the drawings as necessary, but the present invention is not limited thereto, and the gist thereof Various modifications are possible without departing from the scope. In the drawings, the same elements will be denoted by the same reference symbols, without redundant description. In addition, the positional relationship such as up, down, left, and right is based on the positional relationship shown in the drawings unless otherwise specified. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios. In the present specification, “(meth) acryl” means both acryl and methacryl corresponding thereto.

[Inkjet recording method]
In the ink jet recording method of the present embodiment, the reaction liquid is sent from the reaction liquid container to the nozzle hole of the ink jet head via a reaction liquid flow path connecting the reaction liquid container to the nozzle hole of the ink jet head. A reaction liquid adhering step of ejecting the ink composition from the nozzle hole to adhere to the recording medium; and an ink ejecting an ink composition containing at least a coloring material from the nozzle hole of the ink jet head to adhere to the recording medium. Wherein the reaction liquid includes a (meth) acrylic resin, and a polyvalent metal salt as a coagulant that reacts with a component of the ink composition. At least a part of the members constituting the reaction liquid flow path that come into contact with the reaction liquid is a member containing a fatty acid having 6 or more carbon atoms.

(Reaction liquid attachment step)
In the reaction liquid attaching step, the reaction liquid is sent from the reaction liquid container to the nozzle hole of the inkjet head via a reaction liquid flow path connecting the reaction liquid container to the nozzle hole of the inkjet head, and This is a step of ejecting and attaching to the recording medium.

  FIG. 1 is a block diagram illustrating an example of a configuration of a recording apparatus that can be used in the present embodiment. A printer driver is installed in the computer 130, and print data corresponding to the image is output to the printer 1 in order to cause the printer 1 to record the image. The printer 1 corresponds to a “recording device”. The printer 1 includes an ink supply unit 10, a transport unit 20, a head unit 30, a drying unit 40, a maintenance unit 50, a detector group 110, a memory 123, an interface 121, and a controller 120. The controller 120 has a CPU 122 and a unit control circuit 124. The printer 1 that has received the print data from the computer 130, which is an external device, controls each unit by the controller 120, controls various recording conditions, and records an image on a recording medium according to the print data. The status inside the printer 1 is monitored by the detector group 110, and the detector group 110 outputs a detection result to the controller 120. The controller 120 controls each unit based on the detection result output from the detector group 110, and stores the print data input via the interface 121 in the memory 123. The memory 123 also stores control information for controlling each unit. The drying unit 40 includes a heater, a blowing unit, and the like, and dries a composition such as ink adhered to a recording medium.

(Inkjet head)
The head unit 30 included in the recording apparatus (printer 1) includes a head (inkjet head) that performs recording by discharging a reaction liquid or an ink composition toward a recording medium. The head is provided with cavities for discharging the reaction liquid contained in the reaction liquid container or the ink composition contained in the ink container from the nozzles, and a discharge drive provided for each of the cavities for applying a driving force for discharging ink to the ink. And a nozzle provided for each cavity, for discharging the ink composition to the outside of the head, and a nozzle forming surface on which the nozzle is formed. A plurality of cavities and a plurality of ejection drivers and nozzles provided for each cavity may be provided in one head independently of each other. The ejection drive unit is formed using an electromechanical transducer such as a piezoelectric element that changes the volume of the cavity by mechanical deformation, or an electrothermal transducer that generates and discharges bubbles in ink by generating heat. be able to. The recording apparatus may be provided with one head or a plurality of heads for one color ink. In the case where a plurality of heads are provided, the line head is arranged by arranging a plurality of heads in the width direction of the recording medium. The recording width may be increased in this case. When recording is performed using the ink compositions of a plurality of colors, the recording apparatus includes a head for each ink. The head can be configured, for example, as shown in FIG. 3 of JP-A-2009-279830.

  When the recording device is a line printer that is a line type recording device, a line head having a length equal to or longer than the width of the recording medium is provided as a head. The ink composition is ejected from the line head toward the recording medium while changing the position of the line head and the recording medium relatively in the scanning direction that intersects the width direction. In a line printer, the head is fixed without moving (almost), and printing is performed in one pass (single pass). The line printer is more advantageous than the serial printer in that the recording speed is faster.

  Here, the above-mentioned “ink jet head having a nozzle array width longer than the recording width of the recording medium” is used when the width of the recording medium and the length (width) of the line head completely match. However, they are not limited to each other, and may be different from each other. In such a case, for example, the length (width) of the line head is a length corresponding to the width (recording width) of the recording medium on which the ink composition is to be ejected (image is to be recorded). There are some cases.

  On the other hand, a serial printer, which is a serial recording apparatus, performs a main scan (pass) in which a head moves in a main scanning direction intersecting a sub-scanning direction of a recording medium and discharges an ink composition. Printing is performed by the above (multi-pass).

(Reaction liquid container)
The “reaction liquid container” refers to one that directly stores a reaction liquid. Examples of the container include, but are not limited to, a reaction solution cartridge, a pack, a bottle, and a tank. Among these, packs are more preferred.

  The use mode of the container is not particularly limited. For example, a container separate from the recording device is mounted on the recording device, and in the mounted state, the ink composition is supplied from the container to the recording device. An embodiment (A) such as a cartridge, an embodiment (B) such as an ink tank of a recording device to which a reaction liquid is supplied from a container separate from the recording device, and a container are provided in advance as a part of the recording device. Mode (C). In these embodiments, recording can be performed by supplying the ink composition from the attached reaction liquid container to the head of the recording apparatus via a connection portion such as an ink tube.

(Reaction liquid flow path)
The “reaction liquid flow path” refers to a flow path through which a reaction liquid flows in an ink jet recording apparatus. The reaction liquid flow path includes, for example, an ink supply path for supplying the reaction liquid from the reaction liquid container that stores the reaction liquid to the inkjet head, and a flow path for flowing the reaction liquid to the nozzle hole inside the inkjet head. Road.

[Fatty acids with 6 or more carbon atoms]
At least a part of the members constituting the reaction solution container and the reaction solution flow path that are in contact with the reaction solution are members containing a fatty acid having 6 or more carbon atoms. Of the members constituting the reaction solution container and the reaction solution flow path, at least a part of the member that comes into contact with the reaction solution, the member containing a fatty acid having 6 or more carbon atoms is simply referred to as " Also referred to as "member containing fatty acid". The member that comes into contact with the reaction liquid in the reaction liquid container is not particularly limited, and examples thereof include an inner wall material of the pack and a member at the outlet of the reaction liquid of the pack. The member that comes into contact with the reaction liquid in the reaction liquid flow path is not particularly limited, and includes, for example, an inner wall material of an ink tube (ink supply path), an inner wall material of an inkjet head, and an inner wall material of a connection portion thereof. Can be

  The fatty acid having 6 or more carbon atoms is not particularly limited. For example, hexanoic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, pentadecyl acid, palmitic acid, palmitoleic acid, margaric acid, olein Acids, linoleic acid, linolenic acid, arachidic acid, stearic acid. Of these, stearic acid is preferred.

  The fatty acid has 6 or more carbon atoms, more preferably 10 or more carbon atoms, and the upper limit is more preferably 25 or less, and further preferably 20 or less. When the carbon number of the fatty acid is within the above range, it is preferable in that the member is easily available and the durability of the member is excellent.

  The total mass A (parts by mass) of the (meth) acrylic resin contained in the reaction solution container and the reaction solution present in the reaction solution flow path with respect to the total amount of fatty acids eluted from the member containing the fatty acid M (parts by mass) Is preferably at least 0.1, more preferably at least 2.0, further preferably at least 200, even more preferably at least 500, particularly preferably at least 1,000. It is. Although the upper limit is not limited, it is preferably 50,000,000 or less, more preferably 100,000 or less, and further preferably 10,000 or less.

The total eluted amount M is the total amount of fatty acids that can be eluted from the entire member containing fatty acids. The total elution amount M is calculated as follows. First, a member that comes into contact with the reaction liquid from a recording apparatus to be used is prepared as a test piece having a surface area of 120 cm ² for each type of the member. This is adhered inside the glass container. Next, 2% by mass of calcium acetate solids, 20% by mass of propylene glycol, and the remaining amount of water are mixed to prepare a reaction solution of 100% by mass in total, and this is prepared as a test solution. 50 ml of the test solution is placed in a glass container, and the surface of the member is completely immersed in the solution, and the container is covered and sealed. Thereafter, the test liquid is left at 70 ° C. for 6 days. Then, the content of the fatty acid contained in the test liquid taken out of the glass container is measured, and the content of the fatty acid having 6 or more carbon atoms contained in the test liquid is determined. The content (mass g) of the obtained fatty acid is divided by the surface area (120 cm ² ) of the member, and the elution amount B of the fatty acid having 6 or more carbon atoms per 1 cm ² of the surface area of the member containing fatty acid according to the type of the member g / cm ² ).
The content of the fatty acid contained in the test solution was measured by passing 50 ml of the test solution left as described above through a filter for filtration (φ: 10 μm), and having 6 or more carbon atoms remaining on the filter without passing through the filter. Analyze fatty acid content. The content of fatty acids having 6 or more carbon atoms is analyzed by a known analysis method.

Thereafter, the total area S that comes into contact with the reaction solution is calculated for each type of member. From the elution amount B and the total area S, the total elution amount M can be calculated based on the following equation. When two or more members are used, the value is calculated by the following formula. However, when one member contains a fatty acid having 6 or more carbon atoms, it is obvious that B ₂ × S _{2 and} thereafter are 0. .
The total elution volume _{M = B 1 × S 1 +} B 2 × S 2 + B 3 × S 3 ···
1, 2, 3...: Type of member B ₁ : amount of fatty acid eluted from member 1 B (g / cm ² )
S ₁ : total area of the member 1 used in the recording device, which comes into contact with the reaction solution

  In addition, regarding the calculation of the elution amount B, the elution amount B on the surface of each member that contacts the reaction solution is calculated. Specifically, when a pack is used as the reaction solution container, the elution amount B from the inner surface of the film of the pack is calculated. When a tube is used as the reaction solution channel, the elution amount B from the inner surface side of the tube is calculated.

The total mass A is the total mass of the (meth) acrylic resin contained in the reaction solution contained in the reaction solution container and the reaction solution flow path. The total mass A can be calculated as follows. First, the maximum amount Y (g) of the reaction liquid filled in the reaction liquid container and the reaction liquid flow path of the recording apparatus to be used is calculated. Next, the content C (wt%) of the (meth) acrylic resin in the reaction solution to be used is calculated. Thereafter, the total mass A can be calculated from the following equation.
Total mass A = Y × C × 0.01

(Reaction liquid)
The reaction liquid contains a (meth) acrylic resin and a polyvalent metal salt as an aggregating agent for aggregating the components of the ink composition.

((Meth) acrylic resin)
The (meth) acrylic resin is not particularly limited, and examples thereof include a polymer or copolymer containing (meth) acrylic acid or (meth) acrylic acid ester as a constituent unit. Among them, a polymer or a copolymer containing (meth) acrylic acid as a constitutional unit is preferable. More specifically, although not particularly limited, for example, polyacrylic acid, acrylic acid-acrylonitrile copolymer, acrylic acid-acrylic ester copolymer, styrene-acrylic acid copolymer, styrene-α-methylstyrene -Acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymer, vinylnaphthalene-acrylic acid copolymer, vinyl acetate-acrylic acid copolymer, and salts thereof. As the form of the copolymer, any form of a random copolymer, a block copolymer, an alternating copolymer, and a graft copolymer can be used.

  Examples of the salt of the (meth) acrylic resin include (meth) acrylic resin, ammonia, ethylamine, diethylamine, triethylamine, propylamine, isopropylamine, dipropylamine, butylamine, isobutylamine, diethanolamine, triethanolamine, triethanolamine. Salts with basic compounds such as iso-propanolamine, aminomethylpropanol, morpholine and the like can be mentioned. The addition amount of these basic compounds is not particularly limited, but is preferably equal to or more than the neutralization equivalent of the resin dispersant.

  The content of the structural unit composed of (meth) acrylic acid or (meth) acrylic acid ester is preferably from 40% by mass to 100% by mass, more preferably 50% by mass, based on the total amount of the (meth) acrylic resin. It is at least 100% by mass, more preferably at least 70% by mass and at most 100% by mass, particularly preferably at least 90% by mass and at most 100% by mass. When the content is within the above range, the image quality tends to be further excellent, and the ejection property and the like tend to be further excellent.

Among these, a water-soluble resin (solution type) is preferable in terms of dischargeability and the like. By using such a (meth) acrylic resin, the dischargeability tends to be further improved. Here, the “water-soluble resin” refers to a solution in which, when a 5% by mass aqueous solution is used, at 25 ° C., the aqueous solution does not look turbid or insoluble matter does not appear.
Other than the above-mentioned water-soluble resin, a resin dispersion such as an emulsion type may be used.

  Further, the (meth) acrylic resin is preferably a pigment dispersant used for dispersing the pigment of the aqueous ink composition. The pigment dispersant used for dispersing the pigment in the water-based ink composition is not particularly limited. For example, polyacrylic acid, acrylic acid-acrylonitrile copolymer, acrylic acid-acrylic ester copolymer, styrene-acrylic Acid copolymer, styrene-α-methylstyrene-acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid-acrylate copolymer, vinylnaphthalene-acrylic acid copolymer, vinyl acetate-acrylic acid copolymer Examples thereof include polymers and the like and salts thereof.

  The content of the (meth) acrylic resin is preferably 0.05 to 35% by mass relative to the total amount of the reaction solution, and the upper limit is preferably 30% by mass or less, more preferably 20% by mass or less. Yes, more preferably 10% by mass or less, and the lower limit is preferably 0.10% by mass or more.

(Polyvalent metal salt)
The polyvalent metal salt functions as an aggregating agent for aggregating the components of the ink composition. Such a polyvalent metal salt is not particularly limited, but for example, a polyvalent metal salt of an inorganic acid or a polyvalent metal salt of an organic acid is preferable. Such polyvalent metal salts are not particularly limited, but include, for example, alkaline earth metals of Group 2 of the periodic table (eg, magnesium and calcium) and transition metals of Group 3 of the periodic table (eg, lanthanum). And salts of earth metals belonging to Group 13 of the periodic table (for example, aluminum) and lanthanides (for example, neodymium). As the salts of these polyvalent metals, carboxylate (formic acid, acetic acid, benzoate and the like), sulfate, nitrate, chloride and thiocyanate are preferable. Among them, preferred are calcium salts or magnesium salts of carboxylic acids (such as formic acid, acetic acid, and benzoate), calcium salts or magnesium salts of sulfuric acid, calcium salts or magnesium salts of nitric acid, calcium chloride, magnesium chloride, and thiocyanic acid. Calcium salts or magnesium salts are mentioned. The polyvalent metal and the salt constituting the polyvalent metal salt may be any combination or a hydrate. The polyvalent metal salts may be used alone or in combination of two or more.

  The monovalent metal salt hardly generates foreign matter, but tends to degrade the image quality of the recorded matter obtained.

  The content of the polyvalent metal salt is preferably 0.10 to 35.0% by mass relative to the total mass of the reaction solution of 100% by mass, and the lower limit is preferably 0.50% by mass or more, and more preferably. Is 1.0% by mass or more, and the upper limit is preferably 30.0% by mass or less, more preferably 25.0% by mass or less, still more preferably 20.0% by mass or less, and further preferably It is at most 10.0% by mass, particularly preferably at most 7.5% by mass. When the content of the polyvalent metal salt is within the above range, the image quality of the obtained recorded matter is improved, and when the reaction solution comes into contact with the member, foreign substances due to the reaction with the eluted fatty acid are less likely to be generated. It is in.

  The reaction solution can contain other components as needed. The other components are not particularly limited, but include, for example, organic solvents.

(Moisturizer)
Examples of the humectant include, but are not particularly limited to, hydrocarbon solvents such as toluene, hexane, cyclohexane, benzene, octane, and isooctane; ester solvents such as ethyl acetate, butyl acetate, and γ-butyrolactone; acetone, methyl ethyl ketone, and methyl isobutyl. Ketone solvents such as ketone and cyclohexanone; alcohol solvents such as methanol, ethanol, propanol, isopropanol, butanol, glycerin, propylene glycol, triethylene glycol and triethylene glycol monobutyl ether; halogen solvents such as dichloroethane and chloroform; diethyl ether , An ether solvent such as tetrahydrofuran; N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-E -2-pyrrolidone, 2-pyrrolidone, N- methyl -ε- caprolactam, amides hexamethylphosphoramide solvents; Other water soluble organic solvents.

  The total content of the humectant is preferably 5.0 to 35.0% by mass, and the lower limit is preferably 10.0% by mass or more, more preferably 15.0% by mass, based on the total amount of the reaction solution. % Or more. The upper limit is preferably 30.0% by mass or less, more preferably 25.0% by mass or less.

(Water-soluble organic solvent)
The reaction solution may contain an organic solvent. Examples of the organic solvent include the above-mentioned humectants and organic solvents used as penetrants. Alkanediol, glycol ether and the like can be mentioned as organic solvents other than the humectant. The alkanediol is preferably an alkanediol having 3 to 8 carbon atoms. Further, 1,2-alkanediol is preferred. As the glycol ether, those having 3 to 12 carbon atoms in the molecule are preferable. Also, glycol monoether is preferred. The case where the reaction liquid contains an organic solvent is preferable in that the discharge stability when discharging the reaction liquid is excellent. On the other hand, fatty acids having 6 or more carbon atoms tend to elute from the member, and this embodiment is particularly useful.

  The total content of the organic solvent including the humectant is preferably 1.0 to 40% by mass, and the lower limit is preferably 5.0% by mass or more, and more preferably the total amount of the reaction solution. 15.0% by mass or more. The upper limit is preferably 30.0% by mass or less, more preferably 25.0% by mass or less.

(Ink composition adhesion step)
A step of discharging the ink composition containing at least a coloring material from a nozzle hole of an inkjet head and attaching the ink composition to the recording medium. In the ink composition adhering step, an ink composition container and an ink supply path having the same configuration as in the reaction liquid adhering step can be used. Further, the ink composition adhering step and the reaction liquid adhering step can be performed in any order, and among them, it is preferable to perform the reaction liquid adhering step first.

(Ink composition)
The ink composition used in the present embodiment contains at least a coloring material, and may contain a resin, a penetrating solvent, a surfactant, a humectant, and water as needed. As the resin, resin fine particles are preferable.

(Recording medium)
Examples of the recording medium that can be used in the present embodiment include an absorbing or non-absorbing recording medium.

  The absorbent recording medium is not particularly limited. For example, plain paper such as electrophotographic paper having high ink permeability, inkjet paper (an ink absorbing layer composed of silica particles or alumina particles, or polyvinyl alcohol ( PVA) and inkjet paper having an ink absorbing layer composed of a hydrophilic polymer such as polyvinylpyrrolidone (PVP)), art paper, coated paper used for general offset printing having relatively low ink permeability, Cast paper and the like.

  The non-absorbable recording medium is not particularly limited. For example, films and plates of plastics such as polyvinyl chloride, polyethylene, polypropylene, polyethylene terephthalate (PET), polycarbonate, polystyrene, and polyurethane; iron, silver, copper, Plates of metals such as aluminum; or metal plates or plastic films produced by vapor deposition of these metals, plates of alloys such as stainless steel or brass cast; polyvinyl chloride, polyethylene, polypropylene, polyethylene on paper base A recording medium to which a film of a plastic such as terephthalate (PET), polycarbonate, polystyrene, polyurethane or the like is adhered (coated) may be used.

[Inkjet recording device]
The ink jet recording apparatus of the present embodiment includes a reaction liquid container that stores a reaction liquid, and a reaction liquid flow path that connects the reaction liquid container to the nozzle hole of the ink jet head. (Meth) an acrylic resin, and a polyvalent metal salt as an aggregating agent for aggregating the components of the ink composition, among the members constituting the reaction solution container and the reaction solution flow path, of the member that comes into contact with the reaction solution At least a part is a member containing a fatty acid having 6 or more carbon atoms.

  FIG. 2 is a perspective view illustrating a configuration of the recording apparatus (printer 1) according to the present embodiment. The printer 1 shown in FIG. 2 is a serial printer. A serial printer has a head mounted on a carriage that moves in a predetermined direction, and discharges liquid droplets on a recording medium by moving the head in accordance with the movement of the carriage.

  As shown in FIG. 2, the printer 1 includes a carriage 3 on which the head 2 is mounted, a carriage moving mechanism 4 for moving the carriage 3 in the medium width direction of the recording medium P, and a medium for conveying the recording medium P in the medium feeding direction. It has a feed mechanism 5. Further, the printer 1 has a control unit 6 for controlling the operation of the entire printer 1. The medium width direction is the main scanning direction (head scanning direction). The medium feeding direction is a sub-scanning direction (a direction orthogonal to the main scanning direction).

  As shown in FIG. 2, the head 2 is connected via an ink supply pipe 20 (ink flow path) to an ink storage unit 10 that individually stores recording ink and replacement ink. The recording ink and the replacement ink are configured such that each ink can be supplied to the head 2 by the switching unit.

  As the printer 1 according to the present embodiment, a so-called off-carriage type printer in which the ink storage unit 10 is mounted on a casing or the like of the printer 1 and supplies ink to the head 2 via the ink supply pipe 20 is illustrated. However, the present invention is not limited to this. For example, a so-called on-carriage type printer in which an ink cartridge is mounted on a carriage may be used. Further, the present invention may be applied to a line head type printer having no carriage.

  In addition, a home position that is a scanning start point of the head 2 is set outside a region where the recording medium P is conveyed in the moving range of the head 2. At this home position, a maintenance unit 7 including a cap member is provided.

  The maintenance unit 7 is configured to execute a moisturizing operation, a flushing operation, a head cleaning operation, and the like. Specifically, the moisturizing operation is to cap the head 2 with a cap member other than the recording operation to suppress drying of the nozzle holes (not shown) of the head 2. The flushing operation is to prevent the nozzle holes from being clogged by preliminarily discharging the recording ink from the nozzle holes of the head 2 to the cap member. In the head cleaning operation, after capping the head 2 with a cap member, a suction pump (not shown) is driven to discharge ink from each nozzle hole, and replace the recording ink or the replacement ink in the ink flow path with each other. Things.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. The present invention is not limited at all by the following Examples.

[Materials for reaction solution]
[Flocculant: other valent metal salt]
Mg acetate (divalent metal salt)
Na acetate (monovalent metal salt)
[(Meth) acrylic resin]
DISPERBYK-2015 (Big Chemie Japan, solution type)
DISPERBYK-2010 (by Big Chemie Japan, emulsion type)
DISPERBYK-2012 (Big Chemie Japan, solution type)
[Others]
Newcol NT50 (manufactured by Nippon Emulsifier, polyoxyethylene alkyl ether)
(Humectant)
Propylene glycol

[Material of ink composition]
(Pigment)
P. B15: 3
(Penetration solvent)
1,2-hexanediol [surfactant]
BYK348 (silicone-based surfactant, manufactured by BYK Japan KK)
(Humectant)
Propylene glycol

[Preparation of reaction liquid and ink composition]
Each material was mixed with the compositions shown in Tables 1 and 2 below, and thoroughly stirred to obtain each reaction liquid and ink composition. In Tables 1 and 2 below, the unit of the numerical value is% by mass, and the total is 100.0% by mass.

(Dissolution test)
(Test recording device 1)
The test recording apparatus 1 was used as a recording apparatus. The member in contact with the reaction liquid of this recording apparatus was tested by the above-described method, and the elution amount B (g / cm ² ) of fatty acids having 6 or more carbon atoms was determined.

Thereafter, the total area S of the members included in the test recording apparatus that comes into contact with the reaction liquid was calculated for each type of member. Based on the elution amount B and the total area S, the total elution amount M was calculated based on the above equation. In addition, the test recording apparatus 1 uses one kind of member as a polyethylene film constituting a reaction solution container and a reaction solution channel among members that come into contact with the reaction solution, and the fatty acid having 6 or more carbon atoms is used as the polyethylene film. The elution amount B was 0.1 (g / cm ² ), the total area S was 1.0 cm ² , and no other members containing fatty acids having 6 or more carbon atoms were used.

In addition, the maximum amount Y (g) of the reaction solution filled in the reaction solution container and the reaction solution channel of the test recording apparatus 1 was calculated. Next, the (meth) acrylic resin content ratio C (wt%) in each reaction solution used was calculated, and the total mass A corresponding to each reaction solution was calculated from the following formula.
Total mass A = Y × C × 0.01

(Test recording device 2)
When the total dissolution amount M of the test recording device 2 was calculated in the same manner as above, it was 1.0 g. In addition, among the members that come into contact with the reaction liquid of the test recording apparatus 2, the amount B of the fatty acid eluted from the polyethylene film constituting the reaction liquid container and the reaction liquid flow path is 1.0 (g / cm ² ), and the total area S was 1.0 cm ² , and the other members had a fatty acid elution amount B of 0.

In addition, the maximum amount Y (g) of the reaction liquid filled in the reaction liquid container and the reaction liquid flow path of the test recording device 2 was calculated. Next, the (meth) acrylic resin content ratio C (wt%) in each reaction solution used was calculated, and the total mass A corresponding to each reaction solution was calculated from the following formula.
Total mass A = Y × C × 0.01

(Test recording device 3)
When the total elution amount M of the test recording device 3 was calculated in the same manner as above, it was 10.0 g. In addition, among the members that come into contact with the reaction liquid of the test recording device 3, the amount B of the fatty acid eluted from the polyethylene film constituting the reaction liquid container and the reaction liquid flow path is 1.0 (g / cm ² ), and the total area is S was 10 cm ² , and the other members had a fatty acid elution amount B of 0.

Further, the maximum amount Y (g) of the reaction liquid filled in the reaction liquid container and the reaction liquid flow path of the test recording device 3 was calculated. Next, the (meth) acrylic resin content ratio C (wt%) in each reaction solution used was calculated, and the total mass A corresponding to each reaction solution was calculated from the following formula.
Total mass A = Y × C × 0.01

(Durability test)
Two polyethylene films (members 1 to 3) identical to those provided in the test recording device and two polyethylene films (member 4) having the same configuration as member 1 except that they do not contain a fatty acid having 6 or more carbon atoms. And then returned flat. The durability of the member (the durability of the member in contact with the reaction solution) was evaluated according to the following evaluation criteria.
：: The film did not break or break after 5000 times of bending.
X: The film was broken or cut by less than 5,000 bendings.

(Image quality evaluation)
An image quality test was performed using a test recording device. Attach a platen heater to the inkjet printer PX-G930 (trade name, manufactured by Seiko Epson Corporation, nozzle resolution: 180 dpi, 180 nozzles), and supply a reaction liquid supply path from a pack (reaction liquid container, 5 L capacity) to one nozzle row. The reaction liquid was supplied to the ink jet head via. Here, the components from the reaction solution container to the reaction solution supply passage and the nozzle were configured as in the above-described elution amount test.

  Further, the ink composition was supplied to the other nozzle rows from the ink pack (ink composition container) to the inkjet head via the ink supply path. In addition, a filter (φ10 μm) for trapping foreign matter was provided at a position connecting the reaction liquid supply path to the inkjet head. The reaction liquid and the ink used in Tables 1 and 2 were used.

Then, while the surface temperature of the recording surface of the recording medium (trade name “SY51M”, a polypropylene film manufactured by UPM RAFLATA, A4 size) is heated to 40 ° C., the reaction liquid is applied from the head to the recording medium by dot resolution. Coating was performed at 720 × 720 dpi with a coating amount of the reaction solution of 0.5 mg / inch ² . After the application of the reaction liquid, the recording medium was fed backward, fed again, and droplets of the ink composition were attached to the same recording area to record an image. The color ink composition was applied under the conditions of an image resolution of 720 × 720 dpi and an application amount of 5 mg / inch ² . Thereafter, the discharged recording medium was heated and dried at 70 ° C. for 5 minutes to prepare a recorded matter. The reaction liquid and the ink composition were recorded in all the recording areas except for leaving a 1 cm margin around the recording medium.

The obtained recorded matter was visually observed, and the image quality of the obtained recorded matter was evaluated according to the following evaluation criteria.
(Evaluation criteria)
：: No bleed △: Bleed ×: Bleed / aggregation unevenness

[Ejection evaluation]
Using the test recording apparatus used in the image quality evaluation, 3000 g of the reaction liquid was discharged from all the nozzles of the inkjet head to the ink receiver. After the ejection, an ejection test was performed to confirm the presence or absence of a non-ejection nozzle or a nozzle having an ejection bend. The dischargeability was evaluated according to the following evaluation criteria.
(Evaluation criteria)
：: No nozzle in which ejection failure or ejection bending occurred.
Δ: No more than 5 nozzles with non-ejection or ejection bending occurred.
×: Six or more nozzles with non-ejections or ejection bends occurred.

[Filter passage test]
The reaction solution was passed through a filter (φ10 μm filter, liquid passing area: 1 cm). The amount of liquid passing until the filter was clogged was measured and evaluated according to the following evaluation criteria.
(Evaluation criteria)
：: No clogging occurred even when 3000 g or more of liquid was passed.
C: Clogging occurred when the liquid flow was 1000 g or more and less than 3000 g.
×: clogging occurred when the liquid flow was less than 1000 g.

  In Comparative Example 1 in which the reaction solution 4 containing no (meth) acrylic resin was used, foreign matters were generated, and the results of the filter passage test and the dischargeability evaluation were poor. Comparative Example 2 using the reaction solution 5 containing a monovalent metal salt and Comparative Example 3 using the reaction solution 6 containing a monovalent metal salt without containing a (meth) acrylic resin were aggregated. Since the effect was low, bleeding was observed in the obtained recorded matter. Furthermore, in Comparative Example 4 in which the reaction solution 9 containing a surfactant was used instead of the (meth) acrylic resin, foreign matter was generated, and the results of the filter passage test and the evaluation of dischargeability were poor.

  DESCRIPTION OF SYMBOLS 1 ... Printer, 2 ... Head, 3 ... Carriage, 4 ... Carriage moving mechanism, 5 ... Medium feeding mechanism, 6 ... Control part, 7 ... Maintenance unit, 8 ... Ink storage part, 9 ... Ink supply path, P ... Recording medium Reference numeral 10: ink supply unit, 20: transport unit, 30: head unit, 40: irradiation unit, 50: maintenance unit, 110: detector group, 120: controller, 121: interface, 122: CPU, 123: memory, 124 ... Unit control circuit, 130 ... Computer

Claims (10)

A reaction liquid container, an inkjet head, and a reaction liquid flow path, which are performed using an inkjet recording apparatus having:
The reaction liquid is sent from the reaction liquid container to the nozzle hole of the inkjet head through the reaction liquid flow path that connects the reaction liquid container to the nozzle hole of the inkjet head, and is supplied from the nozzle hole. A reaction liquid attaching step of ejecting and attaching to a recording medium,
An ink composition including a coloring material, ejected from a nozzle hole of an inkjet head, and an ink composition adhering step of adhering to a recording medium,
The reaction liquid contains a (meth) acrylic resin and a polyvalent metal salt as an aggregating agent that reacts with components of the ink composition (a colorless colorant that is not a pigment dispersant used for dispersing a pigment in an aqueous ink composition) Or those containing white fine particles),
At least a part of the member that comes into contact with the reaction solution among the members constituting the reaction solution container and the reaction solution channel is a member containing a fatty acid having 6 or more carbon atoms,
The (meth) acrylic resin is the pigment dispersant used for dispersing the pigment in the aqueous ink composition, such as polyacrylic acid, acrylic acid-acrylonitrile copolymer, or acrylic acid-acrylic acid ester copolymer. Copolymer, styrene-acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid-acrylate copolymer, vinylnaphthalene-acrylic acid copolymer, acetic acid vinyl - acrylic acid copolymer, or at least one of these salts seen including,
The content of the (meth) acrylic resin is 10 to 35% by mass based on the total amount of the reaction solution.
Ink jet recording method.   The inkjet recording method according to claim 1, wherein the fatty acid includes a fatty acid having 6 to 25 carbon atoms.   The inkjet recording method according to claim 1, wherein the (meth) acrylic resin includes a water-soluble resin.   The inkjet recording method according to any one of claims 1 to 3, wherein the reaction liquid contains water. The inkjet recording method according to any one of claims 1 to 4, wherein the content of the (meth) acrylic resin is 10 to 30 % by mass based on the total amount of the reaction solution. The inkjet recording method according to claim 5 , wherein the content of the (meth) acrylic resin is 10 to 20 % by mass based on the total amount of the reaction solution.   The inkjet recording method according to any one of claims 1 to 6, wherein the content of the polyvalent metal salt is 0.10 to 10% by mass based on the total amount of the reaction solution. The reaction liquid container is a pack or a bottle, an ink jet recording method according to any one of claims 1-7. The inkjet recording method according to any one of claims 1 to 8 , wherein the inkjet recording device is an off-carriage type serial printer or a line printer. An ink jet recording apparatus which performs recording by the ink jet recording method according to any one of claims 1-9.