JP2016215619A - Inkjet recording method and inkjet recording apparatus - Google Patents

Abstract

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 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 ink jet head. A reaction liquid adhering step of ejecting the ink composition from the nozzles and attaching the ink composition to the recording medium, and an ink composition adhering step of ejecting an 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. Wherein the reaction liquid contains a (meth) acrylic resin and a polyvalent metal salt as a coagulant that reacts with a component of the ink composition, and the reaction liquid container and the reaction liquid flow path An inkjet recording method, wherein at least a part of the constituent members that come into contact with the reaction liquid is a member containing a fatty acid having 6 or more carbon atoms. [Selection diagram] None

Description

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

  The ink jet recording method is capable of recording high-definition images with a relatively simple device, and has been rapidly developed in various fields. Among them, various studies have been made on ejection stability and the like. For example, Patent Document 1 discloses an inkjet recording reaction that is used together with a colored pigment ink and causes a reaction when contacted with the colored pigment ink, as one of the problems to provide a reaction liquid for inkjet recording capable of continuous ejection. A reaction liquid for ink jet recording, which is a liquid and contains (a) a polyvalent metal salt, (b) maleic acids, and (c) a liquid medium is disclosed.

JP 2009-137056 A

  However, Patent Document 1 does not describe at all that foreign matter is generated due to the interaction between the reaction liquid and the members of the ink jet recording apparatus, which causes discharge failure. The reaction liquid containing the polyvalent metal salt elutes the components contained in the member that contacts the reaction liquid among the members constituting the ink jet recording apparatus. When such components are eluted in the reaction solution, foreign matter is generated, leading 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 above-described problems, and an object of the present invention is to provide a reaction liquid that is excellent in dischargeability and excellent in image quality of a recorded matter to be obtained.

  The present inventors diligently studied to solve the above problems. As a result, the present invention has been completed by finding that the above problem can be solved by an ink jet recording method using a predetermined reaction liquid and a predetermined recording apparatus.

That is, the present invention is as follows.
[1]
The reaction liquid is fed from the reaction liquid container to the nozzle hole of the ink jet head via the reaction liquid flow path connecting the reaction liquid container to the nozzle hole of the ink jet head, and discharged from the nozzle hole. A reaction liquid attaching step for attaching to a recording medium;
An ink composition including a coloring material, ejected from a nozzle hole of an inkjet head, and adhered to a recording medium, and an ink composition attaching step,
The reaction liquid includes a (meth) acrylic resin and a polyvalent metal salt as an aggregating agent that reacts with components of the ink composition,
Of the members constituting the reaction liquid container and the reaction liquid flow path, at least a part of the member that contacts the reaction liquid is a member containing a fatty acid having 6 or more carbon atoms.
Inkjet recording method.
[2]
The inkjet recording method according to item [1], wherein the fatty acid contains a fatty acid having 6 to 25 carbon atoms.
[3]
The inkjet recording method according to [1] or [2] above, 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 (meth) acrylic resin is a pigment dispersant used for dispersing a pigment of an aqueous ink composition.
[5]
The inkjet recording method according to any one of [1] to [4], wherein the content of the (meth) acrylic resin is 0.10 to 20% by mass with respect to the total amount of the reaction solution. .
[6]
The total amount of the (meth) acrylic resin contained in the reaction solution container and the reaction solution present in the reaction solution channel with respect to the total elution amount M (parts by mass) of the fatty acid eluted from the fatty acid-containing member. The inkjet recording method according to [1], wherein the ratio (A / M) of mass A (parts by mass) is 200 or more.
[7]
The inkjet recording method according to any one of [1] to [6], wherein a content of the polyvalent metal salt is 0.10 to 10% by mass with respect to a total amount of the reaction solution.
[8]
An ink jet recording apparatus that performs recording by the ink jet recording method according to any one of [1] to [7].

The block diagram which shows an example of a structure of the recording device which can be used for this embodiment is shown. The perspective view which shows the recording device in this 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. However, the present invention is not limited to this, and the gist thereof is described below. Various modifications are possible without departing from the scope. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, positional relationships such as up, down, left and right are based on the positional relationships 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 acrylic and methacryl corresponding thereto.

[Inkjet recording method]
In the ink jet recording method of the present embodiment, the reaction liquid is fed from the reaction liquid container to the nozzle hole of the ink jet head via the reaction liquid channel connecting the reaction liquid container to the nozzle hole of the ink jet head. And a reaction liquid adhering step that is ejected from the nozzle hole to adhere to the recording medium, and an ink that is ejected from the nozzle hole of the ink jet head by an ink composition containing at least a coloring material to adhere to the recording medium. A composition adhering step, wherein the reaction liquid includes a (meth) acrylic resin and a polyvalent metal salt as an aggregating agent that reacts with components of the ink composition, and the reaction liquid container and the Of the members constituting the reaction liquid flow path, at least a part of the members that are in contact with the reaction liquid is a member containing a fatty acid having 6 or more carbon atoms.

[Reaction solution adhesion process]
In the reaction liquid attaching step, the reaction liquid is fed from the reaction liquid container to the nozzle hole of the ink jet head through the reaction liquid flow path connecting the reaction liquid container to the nozzle hole of the ink jet head, and then from the nozzle hole. It is a step of discharging and adhering to the recording medium.

  FIG. 1 is a block diagram showing an example of the configuration of a recording apparatus that can be used in this 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 an image. The printer 1 corresponds to a “recording apparatus”. 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 includes 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 situation in the printer 1 is monitored by the detector group 110, and the detector group 110 outputs the 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 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 blower, and the like, and dries a composition such as ink attached 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 includes a cavity that discharges the reaction liquid stored in the reaction liquid container or the ink composition stored in the ink container from the nozzle, and a discharge drive that is provided for each of the cavities and applies a driving force to discharge the ink. And a nozzle 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 ejection drive units 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 conversion element such as a piezoelectric element that changes the volume of the cavity by mechanical deformation, or an electrothermal conversion element 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 each color ink. When a plurality of heads are provided, the line heads are arranged by arranging a plurality of heads in the width direction of the recording medium. In this case, the above-mentioned recording width can be increased. When recording is performed using 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 apparatus is a line printer that is a line type recording apparatus, the head includes a line head having a length equal to or longer than the length of the recording medium. The ink composition is ejected from the line head toward the recording medium while the position of the line head and the recording medium is relatively changed in the scanning direction intersecting the width direction. In the line printer, the head is fixed without moving (almost), and recording is performed in one pass (single pass). A line printer is advantageous over a serial printer in that the recording speed is high.

  Here, in the above-mentioned “inkjet head having a nozzle row width longer than the recording width of the recording medium”, the width of the recording medium and the length (width) of the line head are completely the same. However, they 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 (recorded width) of the recording medium on which the ink composition is to be ejected (image should be recorded). There are some cases.

  On the other hand, a serial printer, which is a serial type recording apparatus, performs main scanning (pass) in which the ink composition is ejected while the head moves in the main scanning direction intersecting the sub-scanning direction of the recording medium, and usually two passes. Recording is performed as described above (multipass).

[Reaction liquid container]
“Reaction liquid container” refers to a substance that directly contains a reaction liquid. Examples of the container include, but are not limited to, a reaction liquid cartridge, a pack, a bottle, and a tank. Among these, a pack is more preferable.

  The usage mode of the container is not particularly limited. For example, a container that is separate from the recording apparatus is mounted on the recording apparatus, and the ink composition is supplied from the container to the recording apparatus in the mounted state. Aspect (B) such as an ink tank of a recording apparatus to which a reaction liquid is supplied from a container separate from the recording apparatus and the aspect (A) such as a cartridge, and a container are provided in advance as a part of the recording apparatus And the embodiment (C) described above. 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 connecting portion such as an ink tube.

[Reaction solution flow path]
“Reaction liquid flow path” refers to a flow path for circulating a reaction liquid in an ink jet recording apparatus. Examples of the reaction liquid channel include 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 for circulating the reaction liquid to the nozzle hole in the inkjet head. A road is mentioned.

[C6 or more fatty acids]
Of the members constituting the reaction liquid container and the reaction liquid flow path, at least a part of the members in contact with the reaction liquid is a member containing a fatty acid having 6 or more carbon atoms. Of the members constituting the reaction liquid container and the reaction liquid flow path, at least part of the members that come into contact with the reaction liquid and containing fatty acids having 6 or more carbon atoms are simply referred to as “ Also referred to as “member containing fatty acid”. The member in 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. In addition, the member in contact with the reaction liquid in the reaction liquid channel is not particularly limited, and examples thereof include 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. It is done.

  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, pentadecylic acid, palmitic acid, palmitoleic acid, margaric acid, olein Examples include acid, linoleic acid, linolenic acid, arachidic acid, and stearic acid. Of these, stearic acid is preferred.

  The number of carbon atoms of the fatty acid is 6 or more, more preferably 10 or more, and the upper limit is more preferably 25 or less, and even more preferably 20 or less. When the number of carbon atoms 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 (mass part) of the (meth) acrylic resin contained in the reaction liquid contained in the reaction liquid container and the reaction liquid flow path with respect to the total elution amount M (mass part) of the fatty acid eluted from the member containing the fatty acid. The ratio (A / M) is preferably 0.1 or more, more preferably 2.0 or more, still more preferably 200 or more, still more preferably 500 or more, and particularly preferably 1000 or more. It is. Although an upper limit is not restrict | limited, Preferably it is 50 million or less, More preferably, it is 100,000 or less, More preferably, it is 10,000 or less.

The total elution 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 solution 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 member. This is affixed inside the glass container. Next, 2% by mass of calcium acetate as a solid content, 20% by mass of propylene glycol, and the remaining amount of water are mixed to prepare a total of 100% by mass of a reaction solution, which is prepared as a test solution. 50 ml of the test solution is put in a glass container, the surface of the member is completely immersed in the solution, and the container is covered and sealed. Thereafter, the test solution is allowed to stand at 70 ° C. for 6 days. Thereafter, the content of fatty acid contained in the test solution taken out from the glass container is measured, and the content of fatty acid having 6 or more carbon atoms contained in the test solution 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 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 member ( g / cm ² ).
The fatty acid content in the test solution is measured by passing 50 ml of the test solution after standing 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 in 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 formula. When two or more types of members are used, the following formula is used. However, when the number of members containing a fatty acid having 6 or more carbon atoms is one, it is not necessary to say that B ₂ × S ₂ or later is 0. .
Total elution amount M = B ₁ × S ₁ + B ₂ × S ₂ + B ₃ × S _3.
1, 2, 3...: Member type B ₁ : fatty acid elution amount B (g / cm ² ) of member 1
S ₁ : Total area of the member 1 used in the recording apparatus that 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 in contact with the reaction solution is calculated. Specifically, when a pack is used as the reaction liquid container, the elution amount B from the inner surface side of the pack film is calculated. Further, when a tube is used as the reaction solution flow path, 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 present in the reaction solution container and the reaction solution channel. 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 ratio 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 formula.
Total mass A = Y × C × 0.01

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

((Meth) acrylic resin)
Although it does not specifically limit as (meth) acrylic-type resin, For example, the polymer or copolymer which contains (meth) acrylic acid or (meth) acrylic acid ester as a structural unit is mentioned. Among these, a polymer or copolymer containing (meth) acrylic acid as a structural unit is preferable. More specifically, although not particularly limited, for example, polyacrylic acid, acrylic acid-acrylonitrile copolymer, acrylic acid-acrylic acid ester copolymer, styrene-acrylic acid copolymer, styrene-α-methylstyrene -Acrylic acid copolymer, styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymer, vinyl naphthalene-acrylic acid copolymer, vinyl acetate-acrylic acid copolymer, and the like, 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.

  (Meth) acrylic resin salts include (meth) acrylic resin, ammonia, ethylamine, diethylamine, triethylamine, propylamine, isopropylamine, dipropylamine, butylamine, isobutylamine, diethanolamine, triethanolamine, tri- Examples thereof include salts with basic compounds such as iso-propanolamine, aminomethylpropanol, and morpholine. The addition amount of these basic compounds is not particularly limited, but is preferably a neutralization equivalent or more of the resin dispersant.

  The content of the structural unit composed of (meth) acrylic acid or (meth) acrylic acid ester is preferably 40% by mass or more and 100% by mass or less, more preferably 50%, based on the total amount of (meth) acrylic resin. It is 70 mass% or more, More preferably, it is 70 mass% or more and 100 mass% or less, Most preferably, it is 90 mass% or more and 100 mass% or less. By being within the above-mentioned range, the image quality tends to be further improved, and the ejection properties and the like tend to be further improved.

Among these, a water-soluble resin (solution type) is preferable in terms of dischargeability. By using such a (meth) acrylic resin, the discharge property tends to be further improved. Here, the “water-soluble resin” means a solution in which, when a 5% by mass aqueous solution is used, the aqueous solution does not appear to be cloudy or insoluble matter can be seen at 25 ° C.
Other than the above water-soluble resins, emulsion-type resin dispersions and the like can be used.

  The (meth) acrylic resin is preferably a pigment dispersant used for dispersing the pigment of the water-based ink composition. The pigment dispersant used for dispersing the pigment of the water-based ink composition is not particularly limited, and examples thereof include polyacrylic acid, acrylic acid-acrylonitrile copolymer, acrylic acid-acrylic ester copolymer, and 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 Examples thereof include polymers and salts thereof.

  The content of the (meth) acrylic resin is preferably 0.05 to 35% by mass with respect 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 that aggregates the components of the ink composition. Such a polyvalent metal salt is not particularly limited. For example, a polyvalent metal salt of an inorganic acid or a polyvalent metal salt of an organic acid is preferable. Such a polyvalent metal salt is not particularly limited. For example, the alkaline earth metal of Group 2 of the periodic table (for example, magnesium, calcium), the transition metal of Group 3 of the periodic table (for example, lanthanum) And salts of Group 13 earth metals (for example, aluminum) and lanthanides (for example, neodymium) in the periodic table. As these polyvalent metal salts, carboxylate (formic acid, acetic acid, benzoate, etc.), sulfate, nitrate, chloride, and thiocyanate are suitable. Among them, preferably, calcium salt or magnesium salt of carboxylic acid (formic acid, acetic acid, benzoate, etc.), calcium salt or magnesium salt of sulfuric acid, calcium salt or magnesium salt of nitric acid, calcium chloride, magnesium chloride, and thiocyanic acid. A calcium salt or a magnesium salt is mentioned. The polyvalent metal and the salt constituting the polyvalent metal salt may be a combination of them or a hydrate. In addition, a polyvalent metal salt may be used individually by 1 type, and may use 2 or more types together.

  Monovalent metal salts do not easily generate foreign matter, but tend to deteriorate the image quality of the obtained recorded matter.

  The content of the polyvalent metal salt is preferably 0.10 to 35.0% by mass with respect to 100% by mass of the total mass of the reaction solution, and the lower limit is preferably 0.50% by mass or more, and more preferably. 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 still more preferably It is 10.0 mass% or less, Especially preferably, it is 7.5 mass% or less. 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 and the member are in contact with each other, the foreign matter tends not to be generated due to reaction with the eluted fatty acid. It is in.

  The reaction solution may contain other components as necessary. Although it does not specifically limit as another component, For example, an organic solvent etc. are mentioned.

(Humectant)
The humectant is not particularly limited, but for example, 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 Ether solvents such as tetrahydrofuran, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethylene -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 with respect to the total amount of the reaction solution, and the lower limit is preferably 10.0% by mass or more, and more preferably 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.

(Water-soluble organic solvent)
The reaction solution may contain an organic solvent. Examples of the organic solvent include the above-described moisturizing agents and organic solvents used as penetrants. Examples of organic solvents other than the humectant include alkanediol and glycol ether. As the alkanediol, an alkanediol having 3 to 8 carbon atoms is preferable. Further, 1,2-alkanediol is preferable. As the glycol ether, those having 3 to 12 carbon atoms in the molecule are preferable. Further, glycol monoether is preferable. When a reaction liquid contains an organic solvent, it is preferable at the point which is excellent in the discharge stability at the time of discharging a reaction liquid. On the other hand, the fatty acid having 6 or more carbon atoms tends to be easily eluted 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 with respect to the total amount of the reaction solution, and the lower limit is preferably 5.0% by mass or more, and more preferably. It is 15.0 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 process]
In this step, the ink composition containing at least a coloring material is ejected from a nozzle hole of an inkjet head and adhered to the recording medium. In the ink composition attaching step, an ink composition container and an ink supply path having the same configuration as in the reaction liquid attaching step can be used. Further, the ink composition attaching step and the reaction solution attaching step can be performed in any order, and among these, the reaction solution attaching step is preferably performed first.

[Ink composition]
The ink composition used in the present embodiment includes at least a coloring material, and may include a resin, a penetrating solvent, a surfactant, a humectant, and water as necessary. 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 absorptive or non-absorbable recording medium.

  The absorbent recording medium is not particularly limited. For example, plain paper such as electrophotographic paper having high ink permeability, ink jet paper (an ink absorbing layer composed of silica particles or alumina particles, or polyvinyl alcohol ( Art paper, coated paper, etc. used for general offset printing with relatively low ink permeability, such as PVA) and polyvinyl pyrrolidone (PVP). Examples include cast paper.

  Although it does not specifically limit as a non-absorbable recording medium, For example, films and plates of plastics, such as polyvinyl chloride, polyethylene, polypropylene, polyethylene terephthalate (PET), polycarbonate, polystyrene, polyurethane; iron, silver, copper, Metal plates such as aluminum; or metal plates produced by vapor deposition of these various metals, plastic films, stainless steel and brass alloy plates; polyvinyl chloride, polyethylene, polypropylene, polyethylene on paper substrates Examples thereof include a recording medium in which a plastic film such as terephthalate (PET), polycarbonate, polystyrene, or polyurethane is bonded (coated).

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

  FIG. 2 is a perspective view showing the configuration of the recording apparatus (printer 1) in the present embodiment. The printer 1 shown in FIG. 2 is a serial printer. The serial printer refers to a printer in which a head is mounted on a carriage that moves in a predetermined direction, and droplets are ejected onto a recording medium by moving the head as the carriage moves.

  As shown in FIG. 2, the printer 1 includes a carriage 3 on which the head 2 is mounted, a carriage moving mechanism 4 that moves the carriage 3 in the medium width direction of the recording medium P, and a medium that conveys the recording medium P in the medium feeding direction. A feed mechanism 5 is provided. The printer 1 also has a control unit 6 that controls 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 to an ink storage unit 10 that stores recording ink and replacement ink individually via an ink supply tube 20 (ink channel). The recording ink and the replacement ink are configured so that each ink can be supplied to the head 2 by the switching means.

  As the printer 1 according to the present embodiment, a so-called off-carriage type printer in which the ink container 10 is mounted on the casing of the printer 1 and the ink is supplied to the head 2 via the ink supply pipe 20 is exemplified. 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, it may be used for a line head type printer having no carriage.

  In addition, a home position serving as a scanning start point of the head 2 is set outside the area in which the recording medium P is conveyed in the moving range of the head 2. A maintenance unit 7 including a cap member is provided at the home position.

  The maintenance unit 7 is configured to perform a moisturizing operation, a flushing operation, a head cleaning operation, and the like. Specifically, the moisturizing operation is for capping the head 2 with a cap member other than the recording operation to suppress drying of nozzle holes (not shown) of the head 2. The flushing operation is to prevent the nozzle holes from being clogged by preliminarily discharging 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 the recording ink or replacement ink in the ink flow path is mutually replaced. Is.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. The present invention is not limited in any way by the following examples.

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

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

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

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

Then, the total area S which contacts the reaction liquid of the member with which the recording apparatus for a test is provided was calculated for every kind of member. From the elution amount B and the total area S, the total elution amount M was calculated based on the above formula. The test recording apparatus 1 uses one member as a polyethylene film constituting the reaction solution container and the reaction solution flow path among the members in contact with the reaction solution, and the fatty acid having 6 or more carbon atoms. The elution amount B was 0.1 (g / cm ² ), the total area S was 1.0 cm ² , and other than this, no member containing a fatty acid having 6 or more carbon atoms was used.

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 apparatus 1 was calculated. Subsequently, (meth) acrylic-resin content rate C (wt%) in each reaction liquid to be used was calculated, and the total mass A according to each reaction liquid was calculated from the following formula.
Total mass A = Y × C × 0.01

(Test recording device 2)
In the same manner as described above, the total elution amount M of the test recording apparatus 2 was calculated to be 1.0 g. Of the members in contact with the reaction liquid of the test recording apparatus 2, the elution amount B of fatty acid of 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 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 apparatus 2 was calculated. Subsequently, (meth) acrylic-resin content rate C (wt%) in each reaction liquid to be used was calculated, and the total mass A according to each reaction liquid was calculated from the following formula.
Total mass A = Y × C × 0.01

(Test recording device 3)
In the same manner as described above, the total elution amount M of the test recording apparatus 3 was calculated to be 10.0 g. Of the members in contact with the reaction solution of the test recording apparatus 3, the elution amount B of fatty acid of the polyethylene film constituting the reaction solution container and the reaction solution flow path is 1.0 (g / cm ² ), and the total area S was 10 cm ² , and 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 apparatus 3 was calculated. Subsequently, (meth) acrylic-resin content rate C (wt%) in each reaction liquid to be used was calculated, and the total mass A according to each reaction liquid was calculated from the following formula.
Total mass A = Y × C × 0.01

[Durability test]
Two polyethylene films (member 4) having the same configuration as member 1 except that the same polyethylene film (members 1 to 3) as that provided in the test recording apparatus and a fatty acid having 6 or more carbon atoms are not included. It was repeatedly performed to bend and return to flat. The durability of the member (durability of the member in contact with the reaction solution) was evaluated according to the following evaluation criteria.
A: The film was not torn or cut after being bent 5000 times.
X: The film was torn or cut by bending less than 5000 times.

[Image quality evaluation]
An image quality test was conducted using a test recording machine. A platen heater is attached to an inkjet printer PX-G930 (trade name, manufactured by Seiko Epson Corporation, nozzle resolution: 180 dpi, 180 nozzles), and a reaction liquid supply path from a pack (reaction liquid container, capacity 5 L) to one nozzle row The reaction solution was supplied to the inkjet head via Here, it was set as the structure at the time of performing the above-mentioned elution amount test as a member which comprises from a reaction liquid container to a reaction liquid supply path and a nozzle.

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

Then, with the surface temperature of the recording surface of the recording medium (trade name “SY51M”, UPM RAFLATA polypropylene film, A4 size) being heated to 40 ° C., the reaction liquid is applied from the head to the recording medium. Application was performed at 720 × 720 dpi and a reaction solution application amount of 0.5 mg / inch ² . After the reaction solution was applied, the recording medium was reversely fed and then fed again, and an ink composition droplet was adhered 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 dried by heating at 70 ° C. for 5 minutes to prepare a recorded matter. The reaction liquid and the ink composition were recorded in the entire recording area as a recording area except that a 1 cm margin was left 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 △: With bleed ×: With bleed / aggregation unevenness

(Discharge evaluation)
Using the test recording apparatus used in the image quality evaluation, 3000 g of the reaction liquid was discharged from all nozzles of the inkjet head to the ink receiver. After discharge, a discharge inspection was performed to confirm the presence or absence of nozzles that were not discharged or were bent. Ejectability was evaluated according to the following evaluation criteria.
(Evaluation criteria)
○: No nozzles with non-ejection or ejection bending occurred.
Δ: No more than 5 nozzles with non-discharge or discharge bending occurred.
X: Six or more nozzles in which ejection failure or ejection bending occurred were generated.

[Filter flow test]
The reaction solution was passed through a filter (φ10 μm filter, 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)
A: No clogging occurred even when 3000 g or more was passed.
(Triangle | delta): Clogging generate | occur | produced by the liquid passing through 1000g or more and less than 3000g.
X: Clogging occurred when the liquid flow was less than 1000 g.

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

  DESCRIPTION OF SYMBOLS 1 ... Printer, 2 ... Head, 3 ... Carriage, 4 ... Carriage moving mechanism, 5 ... Medium feed mechanism, 6 ... Control part, 7 ... Maintenance unit, 8 ... Ink storage part, 9 ... Ink supply path, P ... Recording medium DESCRIPTION OF SYMBOLS 10 ... Ink supply unit, 20 ... Conveyance 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 (8)

The reaction liquid is fed from the reaction liquid container to the nozzle hole of the ink jet head via the reaction liquid flow path connecting the reaction liquid container to the nozzle hole of the ink jet head, and discharged from the nozzle hole. A reaction liquid attaching step for attaching to a recording medium;
An ink composition including a coloring material, ejected from a nozzle hole of an inkjet head, and adhered to a recording medium, and an ink composition attaching step,
The reaction liquid includes a (meth) acrylic resin and a polyvalent metal salt as an aggregating agent that reacts with components of the ink composition,
Of the members constituting the reaction liquid container and the reaction liquid flow path, at least a part of the member that contacts the reaction liquid is a member containing a fatty acid having 6 or more carbon atoms.
Inkjet 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 contains a water-soluble resin.   The inkjet recording method according to any one of claims 1 to 3, wherein the (meth) acrylic resin is a pigment dispersant used for dispersing a pigment of an aqueous ink composition.   The inkjet recording method according to any one of claims 1 to 4, wherein a content of the (meth) acrylic resin is 0.10 to 20% by mass with respect to a total amount of the reaction solution.   The total amount of the (meth) acrylic resin contained in the reaction solution container and the reaction solution present in the reaction solution channel with respect to the total elution amount M (parts by mass) of the fatty acid eluted from the fatty acid-containing member. The inkjet recording method according to claim 1, wherein a ratio (A / M) of mass A (part by mass) is 200 or more.   The inkjet recording method according to claim 1, wherein a content of the polyvalent metal salt is 0.10 to 10% by mass with respect to a total amount of the reaction solution.   An ink jet recording apparatus that performs recording by the ink jet recording method according to claim 1.