JP2010167592A - Inkjet recording apparatus and recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To impart image strength without image destruction when fixing, and further to effectively prevent fixing unevenness caused by cockling from occurring. <P>SOLUTION: An inkjet recording apparatus 10 includes a process liquid applying part 14 for applying process liquid onto a recoding medium 24, an image drawing part 16 for forming an image on the recording medium 24 by striking droplets of ink on the recording medium 24 on which the process liquid have applied, and after-processing parts 18, 20 for carrying out dry processing of the image formed on the recording medium 24 and fixation processing by a heating and pressing member 88 while holding and rotationally conveying the recording medium 24 on a rotating conveyance bodies 76, 84 in such a manner that the recording medium 24 is warped with the recorded face on the convex side, wherein the rotating conveyance bodies 76, 84 has a surface temperature of not lower than 50°C and a curvature of 0.002 to 0.0033 (1/mm). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus and a recording method, and more particularly to a direct drawing type ink jet recording apparatus and a recording method for forming an image by directly applying water-based ink to a recording medium.

  Inkjet recording apparatuses are widely used as office printers for business use as well as home printers for personal use because the apparatus configuration is simple and image recording with good image quality is possible. Particularly in office printers for business use, there is a further demand for faster processing.

  On the other hand, there is a demand for an image forming method that satisfies image strength. A fixing step is effective for imparting strength to an image. However, since fixing time is limited at high speed, it is a problem to perform fixing that satisfies the image strength in the limited range.

  Conventionally, a fixing method using a heating and pressing unit is generally used, but is strongly influenced by a dry state. In particular, under high-speed conveyance, insufficient drying causes image destruction (offset) at the time of fixing, and overcoming it becomes a major issue. In addition, if the image is fixed in an insufficiently dried state, the image strength itself after fixing also decreases.

  In Patent Documents 1 and 2, the back surface of the recording medium can be heated even during conveyance by forming the heating fixing means in a curved shape and changing the conveyance direction of the recording medium against the rigidity of the recording medium. A technique for fixing in close contact with a high temperature guide member is disclosed.

  Japanese Patent Application Laid-Open No. H10-228561 discloses a technique for preventing the offset at the time of fixing by providing a preliminary heating unit before the heating and pressing unit to sufficiently perform preliminary heating.

Patent Document 4 discloses a technique for fixing within 5 minutes after printing with at least 50% of the ink solvent remaining.
Japanese Patent Laid-Open No. 5-155007 JP-A-5-104800 JP 2001-162783 A JP 2003-48366 A

  However, when the technique disclosed in Patent Document 1 or Patent Document 2 is applied to a direct drawing type ink jet recording apparatus that forms an image by directly applying water-based ink to a recording medium, adhesion to paper is Although it can be imparted, there is a problem that the surface is not heated and the abrasion resistance is insufficient.

  Further, in the technique disclosed in Patent Document 3, paper cockling progresses due to the permeation of the ink solvent, and is conveyed to the fixing unit in a state where irregularities are formed. A portion where the pressure member does not contact is generated, and fixing unevenness is likely to occur.

  Further, in the technique disclosed in Patent Document 4, an image is transferred to a fixing member, and the image is easily destroyed.

  The present invention has been made in view of such circumstances, and can provide image strength without causing image destruction during fixing, and can effectively prevent occurrence of uneven fixing due to cockling. An object is to provide a recording apparatus and a recording method.

  In order to achieve the above object, an ink jet recording apparatus according to the present invention (the invention described in claim 1) includes a processing liquid applying unit that applies a processing liquid containing a component that agglomerates a coloring material in ink to a recording medium. And by applying the ink to the recording medium to which the treatment liquid has been applied, an image forming unit for forming an image on the recording medium, and a recording surface of the recording medium to be a convex side A rotating conveyance body that holds the recording medium in a curved state, and drying and heating the image formed on the recording medium while rotating and conveying the recording medium held on the rotation conveyance body A post-processing unit that performs a fixing process with a pressure member, the surface temperature of the rotary transport body is 50 ° C. or higher, and the curvature of the rotary transport body is 0.002 (1 / mm) or higher. 0033 (1 / mm) or less I am characterized in.

  According to the present invention, a recording medium in which the ink solvent is unevenly distributed on the surface of the image by the aggregation reaction of the treatment liquid and the ink is recorded on the rotary carrier having the predetermined curvature and the surface heated to the predetermined temperature. Holding in a curved state so that the surface is convex, and carrying out the drying process and the fixing process while rotating and transporting the recording medium by the rotation of the rotating transport body, the image strength is prevented while preventing image destruction. Further, fixing unevenness due to cockling can be prevented.

  The drying process and the fixing process may be performed by the same rotary transport body or may be performed by different rotary transport bodies.

  According to a second aspect of the present invention, in the ink jet recording apparatus according to the first aspect, the post-processing section includes a drying section and a fixing section, and the recording section of the recording medium is a convex side in the drying section. A first rotary transport body that holds the recording medium in a curved state, and is formed on the recording medium while rotating and transporting the recording medium held by the first rotary transport body. The fixing unit has a second rotating conveyance body that holds the recording medium in a curved state so that the recording surface of the recording medium is convex. A processing unit for fixing the image formed on the recording medium by a heating and pressing member while rotating and conveying the recording medium held by the second rotating and conveying member; 2 has a surface temperature of 50 ° C. or higher, One, the curvature of the rotary conveying member is equal to or is 0.002 (1 / mm) more than 0.0033 (1 / mm) or less.

  According to the second aspect of the present invention, since the first rotary transport body that performs the drying process and the second rotary transport body that performs the fixing process are separated from each other, the curvature and surface of each transport body The temperature can be optimized according to each process, and fixing unevenness due to cockling can be more effectively prevented.

  According to a third aspect of the present invention, in the ink jet recording apparatus according to the first or second aspect, the surface hardness of the heating and pressing member is 71 ° or less.

  According to the invention described in claim 3, by making the surface hardness of the heating and pressing member 71 ° or less and softening, it is possible to expect a follow-up effect on the unevenness of the recording medium caused by cockling, and fixing unevenness Can be prevented more effectively.

  According to a fourth aspect of the present invention, in the ink jet recording apparatus according to any one of the first to third aspects, the fixing process is such that the high boiling point organic solvent remains in the image by 4% or more of the ink droplet ejection amount. It is characterized by heating and pressurizing in the state of being.

  According to the invention described in claim 4, when the moisture in the image is volatilized and the high-boiling organic solvent is concentrated in the image in an appropriate amount (4% or more of the ink ejection amount), the image is not destroyed. While having a certain degree of strength, the surface of the heating and pressing member is easily deformed during fixing. Furthermore, when the image contains a binder component, the image can be traced to the surface of the heat and pressure member in the same way as when the image is heated in advance, and uneven fixing can be prevented more effectively. Can do.

  According to a fifth aspect of the present invention, in the ink jet recording apparatus according to any one of the first to fourth aspects, the drying process is performed after the image is formed on the recording medium by the image forming unit. The drying process is performed within seconds.

  According to the fifth aspect of the present invention, since the ink solvent (moisture) can be volatilized by permeating into the recording medium by drying (within 3 seconds) immediately after drawing, the recording medium can be volatilized. It is easy to prevent cockling, and uneven fixing can be prevented more effectively.

  In order to achieve the above object, the ink jet recording method according to the present invention (the invention according to claim 6) is a processing liquid for applying a processing liquid containing a component for aggregating the coloring material in the ink to a recording medium. An application step, an image forming step of forming an image on the recording medium by ejecting the ink onto the recording medium to which the treatment liquid has been applied, and a recording surface of the recording medium being a convex side. The recording medium is held on a rotating conveyance body in a curved state, and the image formed on the recording medium is dried and heated while the recording medium held on the rotating conveyance body is rotated and conveyed. A post-processing step of performing a fixing process using a pressure member, the surface temperature of the rotary transport body is 50 ° C. or higher, and the curvature of the rotary transport body is 0.002 (1 / mm) or higher. 0033 (1 / mm) or less And characterized in that.

  According to the present invention, a recording medium in which the ink solvent is unevenly distributed on the surface of the image by the aggregation reaction of the treatment liquid and the ink is recorded on the rotary carrier having the predetermined curvature and the surface heated to the predetermined temperature. Holding in a curved state so that the surface is convex, and carrying out the drying process and the fixing process while rotating and transporting the recording medium by the rotation of the rotating transport body, the image strength is prevented while preventing image destruction. Further, fixing unevenness due to cockling can be prevented.

  According to a seventh aspect of the present invention, in the ink jet recording method according to the sixth aspect, the post-processing step includes a drying step and a fixing step, wherein the recording surface of the recording medium is a convex side. The recording medium is formed on the recording medium while the recording medium is held on the first rotary transport body in a curved state and the recording medium held on the first rotary transport body is rotated and transported. An image drying process, wherein the fixing process holds the recording medium on a second rotating conveyance body in a curved state so that a recording surface of the recording medium is convex. The first and second rotations are processing steps for fixing the image formed on the recording medium by a heating and pressing member while rotating and transporting the recording medium held by the second rotational conveyance body. The carrier has a surface temperature of 50 ° C or higher. And, wherein the curvature of said rotating carrier is 0.002 (1 / mm) more than 0.0033 (1 / mm) or less.

  According to the seventh aspect of the present invention, since the first rotary transport body that performs the drying process and the second rotary transport body that performs the fixing process are separated from each other, the curvature and surface of each transport body The temperature can be optimized according to each process, and fixing unevenness due to cockling can be more effectively prevented.

  According to the present invention, a recording medium in which the ink solvent is unevenly distributed on the surface of the image by the aggregation reaction of the treatment liquid and the ink is recorded on the rotary carrier having the predetermined curvature and the surface heated to the predetermined temperature. Holding in a curved state so that the surface is convex, and carrying out the drying process and the fixing process while rotating and transporting the recording medium by the rotation of the rotating transport body, the image strength is prevented while preventing image destruction. Further, fixing unevenness due to cockling can be prevented.

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

  First, the ink and the treatment liquid used in the present invention will be described, and then the ink jet recording apparatus and the recording method according to the present invention will be described.

[Water-based ink]
Hereinafter, the ink (water-based ink) used in the present invention will be described in detail.

  The aqueous ink in the present invention comprises a resin dispersant (A), a pigment (B) dispersed by the resin dispersant (A), self-dispersing polymer fine particles (C), and an aqueous liquid medium (D). It is configured as a dedicated ink containing at least

(Resin dispersant (A))
The resin dispersant (A) is used as a dispersant for the pigment (B) in the aqueous liquid medium (D), and any resin that can disperse the pigment B may be used. The structure of the agent (A) preferably has a hydrophobic structural unit (a) and a hydrophilic structural unit (b). If necessary, the resin dispersant (A) can include a structural unit (c) different from the hydrophobic structural unit (a) and the hydrophilic structural unit (b).

  The composition of the hydrophilic structural unit (b) and the hydrophobic structural unit (a) depends on the degree of hydrophilicity and hydrophobicity of each, but the hydrophobic structural unit (a) is the entire resin dispersant (A). It is preferable to contain more than 80 mass% with respect to the mass of, and 85 mass% or more is more preferable. That is, the hydrophilic structural unit (b) needs to be 15% by mass or less, and when the hydrophilic structural unit (b) is more than 15% by mass, the aqueous liquid medium alone does not contribute to the dispersion of the pigment. The component dissolved in (D) increases, which deteriorates various properties such as the dispersibility of the pigment (B), and causes the discharge properties of the inkjet recording ink to deteriorate.

<Ratio of pigment (B) to resin dispersant (A)>
The weight ratio of the pigment (B) and the resin dispersant (A) is preferably 100: 25 to 100: 140, and more preferably 100: 25 to 100: 50. When the resin dispersant is 100: 25 or more, the dispersion stability and the abrasion resistance tend to be improved. When the resin dispersant is 100: 140 or less, the dispersion stability tends to be improved.

<Pigment (B)>
In the present invention, the pigment (B) is a colored substance (inorganic) which is almost insoluble in water and organic solvents, as described on page 518 of the Chemical Dictionary 3rd edition published on April 1, 1994 (edited by Michinori Oki et al.). In the present invention, organic pigments and inorganic pigments can be used.

  In the present invention, the “pigment (B) dispersed by the resin dispersant (A)” means a pigment dispersed and held by the resin dispersant (A), and the resin dispersed in the aqueous liquid medium (D). The pigment is preferably used as a pigment dispersed and held using the agent (A). The aqueous liquid medium (D) may or may not contain a dispersant.

  In the present invention, the pigment (B) dispersed by the resin dispersant (A) is not particularly limited as long as it is a pigment dispersed and held by the resin dispersant (A). From the viewpoint of ejection stability, a microencapsulated pigment produced by a phase inversion method is more preferable.

  A preferred example of the pigment (B) contained in the present invention is a microencapsulated pigment. The microencapsulated pigment is a pigment in which the pigment is coated with the resin dispersant (A).

  The resin of the microencapsulated pigment needs to use the resin dispersant (A), and is a polymer having self-dispersibility or solubility in water and an anionic group (acidic). It is preferable to use the compound for a resin other than the resin dispersant (A).

<Pigment B>
Examples of pigments that can be used in the present invention include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 14C, 16, 17, 24, 34, 35, 37, 42, 53, 55, 65, 73, 74, 75, 81, 83, 93, 95, 97, 98, 100, 101, 104, 108, 109, 110, 114, 117, 120, 128, 129, 138, 150, 151, 153, 154, 155, 180 etc. are mentioned.

  Examples of magenta ink pigments include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 48 (Ca), 48 (Mn), 48: 2, 48: 3, 48: 4, 49, 49: 1, 50, 51, 52, 52: 2, 53: 1, 53, 55, 57 (Ca), 57: 1, 60, 60: 1, 63: 1, 63: 2, 64, 64: 1, 81, 83, 87, 88, 89, 90, 101 (Bengara) ), 104, 105, 106, 108 (cadmium red), 112, 114, 122 (quinacridone magenta), 123, 146, 149, 163, 166, 168, 170, 172, 177, 178, 179, 184, 185, 190, 193, 202, 209, 2 9 and the like, in particular, C. I. Pigment Red 122 is preferable.

  Further, as pigments for cyan ink, C.I. I. Pigment blue 1, 2, 3, 15, 15: 1, 15: 2, 15: 3, 15: 4, 16, 17: 1, 22, 25, 56, 60, C.I. I. Bat blue 4, 60, 63 and the like. I. Pigment Blue 15: 3 is preferable.

  Examples of other color ink pigments include C.I. I. Pigment orange 5, 13, 16, 17, 36, 43, 51, C.I. I. Pigment green 1, 4, 7, 8, 10, 17, 18, 36, C.I. I. Pigment violet 1 (rhodamine lake), 3, 5: 1, 16, 19 (quinacridone red), 23, 38, and the like. In addition, processed pigments such as graft carbon whose surface is treated with a resin or the like can also be used.

  An example of the black type is carbon black. Specific examples of such carbon black include No. 1 manufactured by Mitsubishi Chemical. 2300, no. 900, MCF88, No. 33, no. 40, no. 45, no. 52, MA7, MA8, MA100, No2200B, etc. are Raven 5750, Raven 5250, Raven 5000, Raven 3500, Raven 1255, Raven 700, etc., manufactured by Columbia, Regal 400R, Regal 330R, Regal 800R, Mal 80 , Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300, Monarch 1400, etc. are Color Black FW1, Color Black FW2, Color Black FW2V, Color Black FW18C, Decksa, etc. lack S150, Color Black S160, Color Black S170, Printex 35, Printex U, Printex V, Printex 140U, Special Black 6, Special Black 5, Special Black4A, Special Black4 and the like.

  The above pigments may be used alone or in combination of a plurality selected from the above-mentioned groups or between the groups.

  The content of the pigment (B) in the aqueous ink in the present invention is preferably 1 to 10% by mass, more preferably 2 to 8% by mass, and 2 to 6% by mass from the viewpoint of dispersion stability and concentration of the aqueous ink. % Is particularly preferred.

<Self-dispersing polymer particles>
The water-based ink used in the present invention contains at least one kind of self-dispersing polymer fine particles. The self-dispersing polymer fine particles in the present invention are water-insoluble which can be dispersed in an aqueous medium by a functional group (particularly an acidic group or a salt thereof) of the pr resin itself in the absence of other surfactant. It refers to fine particles of a water-insoluble polymer which is a polymer and does not contain a free emulsifier.

  Here, the dispersed state refers to both an emulsified state (emulsion) in which a water-insoluble polymer is dispersed in an aqueous medium and a dispersed state (suspension) in which a water-insoluble polymer is dispersed in an aqueous medium in a solid state. It includes the state of.

  The water-insoluble polymer in the present invention is a water-insoluble polymer that can be in a dispersed state in which the water-insoluble polymer is dispersed in a solid state from the viewpoint of ink aggregation rate and ink fixability when contained in a water-soluble ink. preferable.

  The dispersion state of the self-dispersing polymer fine particles in the present invention refers to a solution in which 30 g of a water-insoluble polymer is dissolved in 70 g of an organic solvent (for example, methyl ethyl ketone), and a neutralizing agent capable of neutralizing 100% of the salt-forming group of the water-insoluble polymer. After mixing and stirring (apparatus: stirring apparatus with stirring blade, rotation speed 200 rpm, 30 minutes, 25 ° C.) (sodium hydroxide if the salt-forming group is anionic, acetic acid if cationic) and 200 g of water The state in which even after removing the organic solvent from the mixed solution, it can be visually confirmed that the dispersed state exists stably at 25 ° C. for at least one week.

  The water-insoluble polymer means a resin having a dissolution amount of 10 g or less when the resin is dried at 105 ° C. for 2 hours and then dissolved in 100 g of water at 25 ° C., and the dissolution amount is preferable. Is 5 g or less, more preferably 1 g or less. The dissolution amount is the dissolution amount when neutralized with sodium hydroxide or acetic acid according to the kind of the salt-forming group of the water-insoluble polymer.

  The aqueous medium is configured to contain water, and may contain a hydrophilic organic solvent as necessary. In the present invention, it is preferably composed of water and 0.2% by mass or less of a hydrophilic organic solvent with respect to water, and more preferably composed of water.

  The main chain skeleton of the water-insoluble polymer is not particularly limited. For example, a vinyl polymer or a condensation polymer (epoxy resin, polyester, polyurethane, polyamide, cellulose, polyether, polyurea, polyimide, polycarbonate, etc.) is used. it can. Of these, vinyl polymers are particularly preferred.

  Preferable examples of the vinyl polymer and the monomer constituting the vinyl polymer include those described in JP-A Nos. 2001-181549 and 2002-88294. In addition, radical transfer of vinyl monomers using dissociable groups (or substituents that can be induced to dissociable groups), polymerization initiators, and iniferters, or dissociable groups on either initiators or terminators A vinyl polymer in which a dissociable group is introduced at the end of a polymer chain by ionic polymerization using a compound having (or a substituent that can be derived from a dissociable group) can also be used.

  Moreover, as a suitable example of the monomer which comprises a condensation type polymer and a condensation type polymer, what is described in Unexamined-Japanese-Patent No. 2001-247787 can be mentioned.

  The self-dispersing polymer fine particles in the present invention preferably contain a water-insoluble polymer containing a hydrophilic constituent unit and a constituent unit derived from an aromatic group-containing monomer from the viewpoint of self-dispersibility.

  The hydrophilic structural unit is not particularly limited as long as it is derived from a hydrophilic group-containing monomer, and even if it is derived from one kind of hydrophilic group-containing monomer, it contains two or more hydrophilic groups. It may be derived from a monomer. The hydrophilic group is not particularly limited, and may be a dissociable group or a nonionic hydrophilic group.

  In the present invention, the hydrophilic group is preferably a dissociable group and more preferably an anionic dissociable group from the viewpoint of promoting self-dispersion and the stability of the formed emulsified or dispersed state. Examples of the dissociable group include a carboxyl group, a phosphoric acid group, and a sulfonic acid group. Among them, a carboxyl group is preferable from the viewpoint of fixability when an ink composition is configured.

  The hydrophilic group-containing monomer in the present invention is preferably a dissociable group-containing monomer from the viewpoints of self-dispersibility and aggregation, and is a dissociable group-containing monomer having a dissociable group and an ethylenically unsaturated bond. It is preferable.

  Examples of the dissociable group-containing monomer include an unsaturated carboxylic acid monomer, an unsaturated sulfonic acid monomer, and an unsaturated phosphoric acid monomer.

  Specific examples of the unsaturated carboxylic acid monomer include acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid, and 2-methacryloyloxymethyl succinic acid. Specific examples of the unsaturated sulfonic acid monomer include styrene sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, 3-sulfopropyl (meth) acrylate, and bis- (3-sulfopropyl) -itaconate. It is done. Specific examples of unsaturated phosphoric acid monomers include vinylphosphonic acid, vinyl phosphate, bis (methacryloxyethyl) phosphate, diphenyl-2-acryloyloxyethyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate, dibutyl-2- Examples include acryloyloxyethyl phosphate.

  Among the dissociable group-containing monomers, unsaturated carboxylic acid monomers are preferable and acrylic acid and methacrylic acid are more preferable from the viewpoints of dispersion stability and ejection stability.

  The self-dispersing polymer fine particle in the present invention is a first polymer having a carboxyl group and an acid value (mgKOH / g) of 25 to 100 from the viewpoints of self-dispersibility and agglomeration speed when contacting with the reaction solution. It is preferable to contain. Furthermore, the acid value is more preferably from 25 to 80, and particularly preferably from 30 to 65, from the viewpoints of self-dispersibility and the aggregation rate when contacting with the reaction solution. When the acid value is 25 or more, the stability of self-dispersibility is improved. Moreover, cohesiveness improves because an acid value is 100 or less.

  The aromatic group-containing monomer is not particularly limited as long as it is a compound containing an aromatic group and a polymerizable group. The aromatic group may be a group derived from an aromatic hydrocarbon or a group derived from an aromatic heterocycle. In the present invention, an aromatic group derived from an aromatic hydrocarbon is preferable from the viewpoint of particle shape stability in an aqueous medium.

  The polymerizable group may be a condensation polymerizable polymerizable group or an addition polymerizable polymerizable group. In the present invention, from the viewpoint of particle shape stability in an aqueous medium, an addition polymerizable group is preferable, and a group containing an ethylenically unsaturated bond is more preferable.

  The aromatic group-containing monomer in the present invention is preferably a monomer having an aromatic group derived from an aromatic hydrocarbon and an ethylenically unsaturated bond, and more preferably an aromatic group-containing (meth) acrylate monomer. preferable. In the present invention, the aromatic group-containing monomers may be used singly or in combination of two or more.

  Examples of the aromatic group-containing monomer include phenoxyethyl (meth) acrylate, benzyl (meth) acrylate, phenyl (meth) acrylate, and a styrene monomer. Among them, from the viewpoint of the balance between the hydrophilicity and hydrophobicity of the polymer chain and the ink fixing property, it is preferably at least one selected from phenoxyethyl (meth) acrylate, benzyl (meth) acrylate, and phenyl (meth) acrylate. More preferred is phenoxyethyl (meth) acrylate, and particularly preferred is phenoxyethyl acrylate.

  “(Meth) acrylate” means acrylate or methacrylate.

  The self-dispersing polymer fine particles in the present invention include a structural unit derived from an aromatic group-containing (meth) acrylate monomer, and the content is preferably 10% by mass to 95% by mass. When the content of the aromatic group-containing (meth) acrylate monomer is 10% by mass to 95% by mass, the stability of the self-emulsification or dispersion state can be improved, and further the increase in ink viscosity can be suppressed.

  In the present invention, from the viewpoints of stability in a self-dispersing state, stabilization of particle shape in an aqueous medium due to hydrophobic interaction between aromatic rings, and reduction in the amount of water-soluble components due to appropriate hydrophobicization of particles. More preferably, the content is from mass% to 90 mass%, more preferably from 15 mass% to 80 mass%, and particularly preferably from 25 mass% to 70 mass%.

  The self-dispersing polymer fine particles in the present invention can be composed of, for example, a structural unit composed of an aromatic group-containing monomer and a structural unit composed of a dissociable group-containing monomer. Can further be included.

  The monomer that forms the other structural unit is not particularly limited as long as it is a monomer copolymerizable with the aromatic group-containing monomer and the dissociable group-containing monomer. Among these, an alkyl group-containing monomer is preferable from the viewpoint of flexibility of the polymer skeleton and ease of control of the glass transition temperature (Tg).

  Examples of the alkyl group-containing monomer include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, alkyl (meth) acrylates such as t-butyl (meth) acrylate, hexyl (meth) acrylate, ethylhexyl (meth) acrylate; hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) Ethylenically unsaturated monomers having a hydroxyl group such as acrylate, 4-hydroxybutyl (meth) acrylate, hydroxypentyl (meth) acrylate, hydroxyhexyl (meth) acrylate; Dialkylaminoalkyl (meth) acrylates such as ru (meth) acrylate; N-hydroxyalkyl (meth) such as N-hydroxymethyl (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, N-hydroxybutyl (meth) acrylamide Acrylamide; N-methoxymethyl (meth) acrylamide, N-ethoxymethyl (meth) acrylamide, N- (n-, iso) butoxymethyl (meth) acrylamide, N-methoxyethyl (meth) acrylamide, N-ethoxyethyl (meta And (meth) acrylamides such as N-alkoxyalkyl (meth) acrylamides such as acrylamide and N- (n-, iso) butoxyethyl (meth) acrylamide.

  The molecular weight range of the water-insoluble polymer constituting the self-dispersing polymer fine particles in the present invention is preferably 3000 to 200,000, more preferably 5000 to 150,000, and more preferably 10,000 to 100,000 in terms of weight average molecular weight. More preferably it is. By setting the weight average molecular weight to 3000 or more, the amount of water-soluble components can be effectively suppressed. Moreover, self-dispersion stability can be improved by making a weight average molecular weight into 200,000 or less. The weight average molecular weight can be measured by gel permeation chromatography (GPC).

  From the viewpoint of controlling the hydrophilicity / hydrophobicity of the polymer, the water-insoluble polymer constituting the self-dispersing polymer fine particles in the present invention comprises an aromatic group-containing (meth) acrylate monomer as a copolymerization ratio of 15 to 90% by mass, a carboxyl group-containing monomer, And an alkyl group-containing monomer, preferably having an acid value of 25 to 100 and a weight average molecular weight of 3000 to 200,000, and an aromatic group-containing (meth) acrylate monomer as a copolymerization ratio of 15 to 80 mass. %, A carboxyl group-containing monomer, and an alkyl group-containing monomer, an acid value of 25 to 95, and a weight average molecular weight of 5000 to 150,000 are more preferable.

Specific examples of the water-insoluble polymer constituting the self-dispersing polymer fine particles are listed below as exemplary compounds B-01 to B-19, but the present invention is not limited thereto. In addition, the parenthesis represents the mass ratio of the copolymerization component.
B-01: Phenoxyethyl acrylate / methyl methacrylate / acrylic acid copolymer (50/45/5)
B-02: Phenoxyethyl acrylate / benzyl methacrylate / isobutyl methacrylate / methacrylic acid copolymer (30/35/29/6)
B-03: Phenoxyethyl methacrylate / isobutyl methacrylate / methacrylic acid copolymer (50/44/6)
B-04: Phenoxyethyl acrylate / methyl methacrylate / ethyl acrylate / acrylic acid copolymer (30/55/10/5)
B-05: benzyl methacrylate / isobutyl methacrylate / methacrylic acid copolymer (35/59/6)
B-06: Styrene / phenoxyethyl acrylate / methyl methacrylate / acrylic acid copolymer (10/50/35/5)
B-07: benzyl acrylate / methyl methacrylate / acrylic acid copolymer (55/40/5)
B-08: Phenoxyethyl methacrylate / benzyl acrylate / methacrylic acid copolymer (45/47/8)
B-09: Styrene / phenoxyethyl acrylate / butyl methacrylate / acrylic acid copolymer (5/48/40/7)
B-10: benzyl methacrylate / isobutyl methacrylate / cyclohexyl methacrylate / methacrylic acid copolymer (35/30/30/5)
B-11: Phenoxyethyl acrylate / methyl methacrylate / butyl acrylate / methacrylic acid copolymer (12/50/30/8)
B-12: benzyl acrylate / isobutyl methacrylate / acrylic acid copolymer (93/2/5)
B-13: Styrene / phenoxyethyl methacrylate / butyl acrylate / acrylic acid copolymer (50/5/20/25)
B-14: Styrene / butyl acrylate / acrylic acid copolymer (62/35/3)
B-15: Methyl methacrylate / phenoxyethyl acrylate / acrylic acid copolymer (45/51/4)
B-16: Methyl methacrylate / phenoxyethyl acrylate / acrylic acid copolymer (45/49/6)
B-17: Methyl methacrylate / phenoxyethyl acrylate / acrylic acid copolymer (45/48/7)
B-18: Methyl methacrylate / phenoxyethyl acrylate / acrylic acid copolymer (45/47/8)
B-19: Methyl methacrylate / phenoxyethyl acrylate / acrylic acid copolymer (45/45/10)
The average particle size of the self-dispersing polymer fine particles in the present invention is preferably in the range of 10 to 400 nm, more preferably 10 to 200 nm, and further preferably 10 to 100 nm. Manufacturability is improved when the average particle diameter is 10 nm or more. Moreover, storage stability improves by setting it as an average particle diameter of 400 nm or less.

  Further, the particle size distribution of the self-dispersing polymer fine particles is not particularly limited, and may be either a wide particle size distribution or a monodispersed particle size distribution. Further, two or more kinds of water-insoluble particles may be mixed and used.

  The average particle size and particle size distribution of the self-dispersing polymer fine particles can be measured using, for example, a light scattering method.

  The self-dispersing polymer fine particles of the present invention can be suitably contained in, for example, an aqueous ink composition, and can be used alone or in combination of two or more.

<Aqueous liquid medium (D)>
In the inkjet recording water-based ink, the aqueous liquid medium (D) represents a mixture of water and a water-soluble organic solvent. Water-soluble organic solvents (hereinafter also referred to as “water-soluble organic solvents”) are used for the purpose of drying inhibitors, wetting agents or penetration enhancers.

  An anti-drying agent is used for the purpose of preventing clogging due to drying of the ink-jet ink at the ink ejection port of the nozzle, and a water-soluble organic solvent having a vapor pressure lower than that of water is preferable as the anti-drying agent or wetting agent. . In addition, a water-soluble organic solvent is suitably used as a penetration accelerator for the purpose of allowing ink jet ink to penetrate better into a recording medium (such as paper).

  Examples of water-soluble organic solvents include glycerin, 1,2,6-hexanetriol, trimethylolpropane, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, dipropylene glycol, 2-butene -1,4-diol, 2-ethyl-1,3-hexanediol, 2-methyl-2,4-pentanediol, 1,2-octanediol, 1,2-hexanediol, 1,2-pentanediol, Alkanediols (polyhydric alcohols) such as 4-methyl-1,2-pentanediol; vulcose, mannose, fructose, ribose, xylose, arabinose, galactose, aldonic acid, glucitol, (sorbitol), maltose, cello Sugars such as aose, lactose, sucrose, trehalose, maltotriose; sugar alcohols; pearronic acids; so-called solid wetting agents such as ureas; alkyl alcohols having 1 to 4 carbon atoms such as ethanol, methanol, butanol, propanol, isopropanol Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, ethylene glycol mono-iso-propyl ether, Diethylene glycol mono-iso-propyl ether, ethylene glycol mono-n-butyl Ether, ethylene glycol mono-t-butyl ether, diethylene glycol mono-t-butyl ether, 1-methyl-1-methoxybutanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-t-butyl ether, propylene glycol mono-n -Glycol ethers such as propyl ether, propylene glycol mono-iso-propyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-iso-propyl ether 2-pyrrolidone, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, phor Examples thereof include muamide, acetamide, dimethyl sulfoxide, sorbite, sorbitan, acetin, diacetin, triacetin, sulfolane and the like, and one or more of these can be used.

  For the purpose of drying inhibitors and wetting agents, polyhydric alcohols are useful. For example, glycerin, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,3-butanediol. 2,3-butanediol, 1,4-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol, tetraethylene glycol, 1,6-hexanediol, 2-methyl-2, Examples include 4-pentanediol, polyethylene glycol, 1,2,4-butanetriol, 1,2,6-hexanetriol, and the like. These may be used individually by 1 type and may use 2 or more types together.

  For the purpose of the penetrant, a polyol compound is preferable. Examples of the aliphatic diol include 2-ethyl-2-methyl-1,3-propanediol, 3,3-dimethyl-1,2-butanediol, 2, 2-diethyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2,4-dimethyl-2,4-pentanediol, 2,5-dimethyl-2,5-hexane Examples include diol, 5-hexene-1,2-diol, and 2-ethyl-1,3-hexanediol. Among these, preferred examples include 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol.

  A water-soluble organic solvent may be used independently or may be used in mixture of 2 or more types. The content of the water-soluble organic solvent is 1 to 60% by mass, preferably 5 to 40% by mass in the ink.

  The amount of water added is not particularly limited in the ink, but is preferably 10% by mass to 99% by mass, and more preferably 30% by mass to 80% by mass. More preferably, it is 50 mass% or more and 70 mass% or less.

  The aqueous liquid medium (D) in the present invention is preferably 60% by mass or more and 95% by mass or less, more preferably 70% by mass or more and 95% by mass or less from the viewpoints of dispersion stability and ejection stability in the ink.

<Surfactant>
It is preferable to add a surfactant (hereinafter also referred to as a surface tension adjusting agent) to the water-based ink in the invention. Examples of the surfactant include nonionic, cationic, anionic and betaine surfactants. The addition amount of the surface tension adjusting agent is preferably an amount for adjusting the surface tension of the water-based ink in the present invention to 20 to 60 mN / m, more preferably 20 to 45 mN / m, in order to eject ink droplets well by inkjet. More preferably, the amount can be adjusted to 25 to 40 mN / m.

  As the surfactant, a compound having a structure having both a hydrophilic part and a hydrophobic part in the molecule can be used effectively. Anionic surfactant, cationic surfactant, amphoteric surfactant, nonionic surfactant Any of the surfactants can be used. Furthermore, the above-mentioned polymer substance (polymer dispersing agent) can also be used as a surfactant.

  Specific examples of the anionic surfactant include, for example, sodium dodecylbenzenesulfonate, sodium lauryl sulfate, sodium alkyldiphenyl ether disulfonate, sodium alkylnaphthalenesulfonate, sodium dialkylsulfosuccinate, sodium stearate, potassium oleate, Sodium dioctylsulfosuccinate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl phenyl ether sulfate, sodium dialkylsulfosuccinate, sodium stearate, sodium oleate, t-octylphenoxy Examples include sodium ethoxypolyethoxyethyl sulfate, and one or more of these are selected. Rukoto can.

  Specific examples of the nonionic surfactant include, for example, polyoxyethylene lauryl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene oleyl phenyl ether, polyoxyethylene nonyl phenyl ether, oxyethylene / oxypropylene block copolymer, t- Examples include octylphenoxyethyl polyethoxyethanol, nonylphenoxyethyl polyethoxyethanol, and the like, and one or more of these can be selected.

  Examples of the cationic surfactant include tetraalkylammonium salts, alkylamine salts, benzalkonium salts, alkylpyridium salts, imidazolium salts, and the like. Specific examples thereof include dihydroxyethyl stearylamine and 2-heptadecenyl. -Hydroxyethyl imidazoline, lauryl dimethyl benzyl ammonium chloride, cetyl pyridinium chloride, stearamide methyl pyridium chloride and the like.

  The amount of the surfactant added to the inkjet recording water-based ink in the present invention is not particularly limited, but is preferably 1% by mass or more, more preferably 1 to 10% by mass, and still more preferably 1%. ˜3 mass%.

<Other ingredients>
The water-based ink used in the present invention may contain other additives. Other additives include, for example, ultraviolet absorbers, anti-fading agents, anti-mold agents, pH adjusters, rust inhibitors, antioxidants, emulsion stabilizers, preservatives, antifoaming agents, viscosity modifiers, and dispersion stabilizers. Known additives such as agents and chelating agents are included.

  Examples of the UV absorber include benzophenone UV absorbers, benzotriazole UV absorbers, salicylate UV absorbers, cyanoacrylate UV absorbers, nickel complex salt UV absorbers, and the like.

  As the antifading agent, various organic and metal complex antifading agents can be used. Organic anti-fading agents include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, heterocycles, etc. Complex, zinc complex and the like.

  Antifungal agents include sodium dehydroacetate, sodium benzoate, sodium pyridinethione-1-oxide, p-hydroxybenzoic acid ethyl ester, 1,2-benzisothiazolin-3-one, sodium sorbate, sodium pentachlorophenol, etc. Can be mentioned. These are preferably used in the ink in an amount of 0.02 to 1.00% by mass.

  The pH adjuster is not particularly limited as long as it can adjust the pH to a desired value without adversely affecting the recording ink to be prepared, and can be appropriately selected according to the purpose. Amines (eg, diethanolamine, triethanolamine, 2-amino-2-ethyl-1,3-propanediol), alkali metal hydroxides (eg, lithium hydroxide, sodium hydroxide, potassium hydroxide), ammonium Examples thereof include hydroxides (for example, ammonium hydroxide and quaternary ammonium hydroxides), phosphonium hydroxides, alkali metal carbonates, and the like.

  Examples of the rust inhibitor include acidic sulfite, sodium thiosulfate, ammonium thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite.

  Examples of the antioxidant include phenol antioxidants (including hindered phenol antioxidants), amine antioxidants, sulfur antioxidants, phosphorus antioxidants, and the like.

  Examples of the chelating agent include sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, sodium uramil diacetate and the like.

[Treatment solution]
Next, the treatment liquid (aqueous treatment liquid) used in the present invention will be described.

  The aqueous treatment liquid in the present invention contains at least one fixing agent for fixing components in the aqueous ink. The fixing agent in the present invention can fix (aggregate) water-based ink by contacting with water-based ink on paper. For example, by applying an aqueous treatment liquid, when the aqueous ink is deposited and contacted in the state where the fixing agent is present on the paper, the components in the aqueous ink can be aggregated and immobilized on the paper. it can.

  Since it is desirable that the water-based ink can be fixed (aggregated), it is preferable that the material be easily dissolved in the water-based ink when coming into contact with the water-based ink. In this respect, the highly water-soluble polyvalent metal salt is more An acidic substance having a high water solubility is more preferable. Further, from the viewpoint of fixing the entire ink by reacting with the aqueous ink, an acidic substance having a valence of 2 or more is particularly preferable. Moreover, a cationic compound can also be used as a fixing agent.

  Here, the aggregation reaction of the water-based ink can be achieved by reducing the dispersion stability of particles dispersed in the water-based ink (colorant (for example, pigment), resin particles, etc.) and increasing the viscosity of the entire ink. it can. For example, by reducing the surface charge of particles such as pigments and resin particles in inks that are stabilized by weakly acidic functional groups such as carboxyl groups by reacting with acidic substances with lower pKa, the dispersion stability is lowered. can do. Therefore, the acidic substance as the fixing agent contained in the aqueous treatment liquid preferably has a low pKa, a high solubility, and a valence of 2 or more, and a functional group that stabilizes the dispersion of particles in the ink. More preferably, it is a divalent or trivalent acidic substance having a high buffering capacity in a pH range lower than the pKa (for example, carboxyl group).

  Specific examples include phosphoric acid, oxalic acid, malonic acid, succinic acid, citric acid, and phthalic acid. In addition, other acidic substances having pKa and solubility similar to these can be used.

  Among these acidic substances, citric acid is preferably used in a system that has a high water retention ability and tends to increase the physical strength of the aggregated ink, and requires more mechanical properties. On the other hand, malonic acid is preferably used when the water retention is low and it is desired to speed up drying of the treatment liquid.

  As described above, the fixing agent can be appropriately selected and used depending on a secondary factor different from the fixing ability of the water-based ink.

  Examples of the polyvalent metal salt include alkaline earth metals belonging to Group 2 of the periodic table (eg, magnesium, calcium), transition metals belonging to Group 3 of the periodic table (eg, lanthanum), and Group 13 of the periodic table. Mention may be made of salts of cations (for example, aluminum) and lanthanides (for example, neodymium). As these metal salts, carboxylate (formic acid, acetic acid, benzoate, etc.), nitrate, chloride, and thiocyanate are suitable. Among them, preferred are calcium salts or magnesium salts of carboxylic acids (formic acid, acetic acid, benzoates, etc.), calcium salts or magnesium salts of nitric acid, calcium chloride, magnesium chloride, and calcium salts or magnesium salts of thiocyanic acid.

  Preferred examples of the cationic compound include cationic surfactants. As the cationic surfactant, for example, a primary, secondary, or tertiary amine salt type compound is preferable. Examples of the amine salt type compounds include compounds such as hydrochloride or acetate (for example, laurylamine, cocoamine, stearylamine, rosinamine), quaternary ammonium salt type compounds (for example, lauryltrimethylammonium chloride, cetyltrimethyl). Ammonium chloride, lauryldimethylbenzylammonium chloride, benzyltributylammonium chloride, benzalkonium chloride, etc.), pyridinium salt type compounds (eg, cetylpyridinium chloride, cetylpyridinium bromide, etc.), imidazoline type cationic compounds (eg, 2-heptadecenyl- Hydroxyethyl imidazoline), ethylene oxide adducts of higher alkylamines (eg dihydroxyethyl stearylamine) It can gel. In addition to these, amphoteric surfactants that exhibit a cationic property in a desired pH range can also be used, such as amino acid type amphoteric surfactants, R-NH-CH2CH2-COOH type compounds, and carboxylate type amphoteric interfaces. Activating agents (for example, stearyl dimethyl betaine, lauryl dihydroxyethyl betaine, etc.), amphoteric surfactants such as sulfate ester type, sulfonic acid type, or phosphate ester type, and the like can be mentioned.

  The said fixing agent can be used individually by 1 type or in mixture of 2 or more types.

  The content of the fixing agent for fixing the water-based ink in the aqueous treatment liquid is preferably 1 to 40% by mass, more preferably 5 to 30% by mass, and still more preferably 10 to 25% by mass. is there.

(Other ingredients)
The aqueous treatment liquid in the present invention can generally contain a water-soluble organic solvent in addition to the fixing agent, and can be constituted by using various other additives. The details of the water-soluble organic solvent and other various additives are the same as those in the aqueous ink described later.

  For applying the aqueous treatment liquid onto the paper, a known liquid application method can be used without particular limitation, and any method such as spray application, application using an application roller, application by an inkjet method, immersion, etc. can be selected. .

  Specifically, for example, a size press method represented by a horizontal size press method, a roll coater method, a calendar size press method, etc .; a size press method represented by an air knife coater method, etc .; Knife coater method; transfer roll coater method such as gate roll coater method, direct roll coater method, reverse roll coater method, roll coater method represented by squeeze roll coater method; bill blade coater method, short duel coater method; Blade coater method typified by stream coater method, etc .; Bar coater method typified by rod bar coater method, etc .; Bar coater method typified by rod bar coater method, etc .; Cast coater method; Gravure coater method; Coater method; die coater method; brush coater method; and the like transfer method.

  Moreover, the method of apply | coating by controlling a coating amount by using the coating device provided with the liquid quantity limiting member like the coating device of Unexamined-Japanese-Patent No. 10-230201 may be used.

  The region to which the aqueous treatment liquid is applied may be the entire surface application to the entire recording medium or the partial application to be partially applied to the region where ink jet recording is performed in the subsequent image recording process. In the present invention, the application amount of the aqueous treatment liquid is uniformly adjusted, and fine lines and fine image portions are recorded uniformly, and recorded by application using an application roller or the like from the viewpoint of suppressing density unevenness such as image unevenness. It is preferable to apply the entire surface to the entire medium.

The amount of fixing agent applied is not particularly limited as long as it is an amount sufficient to stabilize the water-based ink, and is preferably 0.25 g / m ² or more, in that the water-based ink is easily fixed by aggregation. More preferably, it is 0.30 g / m ² or more and less than 2.0 g / m ² , and further preferably 0.40 g / m ² or more and less than 1.0 g / m ² .

  For example, a method using an anilox roller is preferably used as a method for applying the fixing agent in a controlled amount within the above range. An anilox roller is a roller with a ceramic-sprayed roller surface processed with a laser to give it a pyramid shape, a diagonal line, a turtle shell shape, or the like. The aqueous treatment liquid enters the dent portion formed on the roller surface, is transferred when it comes into contact with the paper surface, and is applied in a coating amount controlled by the dent of the anilox roller.

  The surface tension (25 ° C.) of the aqueous treatment liquid is preferably 20 mN / m or more and 60 mN / m or less. More preferably, it is 25 mN / m or less and 50 mN / m or less, More preferably, it is 25 mN / m or more and 45 mN / m or less.

The surface tension is measured using an automatic surface tensiometer CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.) and a water-based ink at 25 ° C.

Further, the viscosity of the aqueous treatment liquid at 25 ° C. is 1.2 mPa · s or more and 15.0 mPa · s or less from the viewpoint of stably applying in the range of 0.5 to 3.5 ml / m ^2. It is preferably 2 mPa · s or more and 12 mPa · s or less, and more preferably 2 mPa · s or more and 8 mPa · s or less. In particular, when the aqueous treatment liquid is applied on paper, the viscosity (25 ° C.) is preferably 2 to 8 mPa · s, and more preferably 2 to 6 mPa · s.

The viscosity is measured using a VISCOMETER TV-22 (manufactured by TOKI SANGYO CO. LTD) under the condition of a water-based ink at 25 ° C.

[Overall configuration of inkjet recording apparatus]
Next, the overall configuration of the ink jet recording apparatus to which the present invention is applied will be described.

  FIG. 1 is a configuration diagram showing the overall configuration of the ink jet recording apparatus according to the present embodiment. An inkjet recording apparatus 10 shown in the figure is a two-liquid aggregation type recording apparatus that forms an image on the recording surface of a recording medium 24 using ink (aqueous ink) and a processing liquid (aggregation processing liquid). The paper unit 12 includes a processing liquid application unit 14, a drawing unit 16, a drying unit 18, a fixing unit 20, and a discharge unit 22. A recording medium 24, which is a sheet, is laminated on the paper supply unit 12, and this recording medium 24 is sent from the paper supply unit 12 to the treatment liquid application unit 14, and the processing liquid application unit 14 processes the recording surface. After the liquid is applied, color ink is applied to the recording surface by the drawing unit 16. The recording medium 24 to which ink has been applied is transported by the discharge unit 22 after the image is fastened by the fixing unit 20.

  In addition, the inkjet recording apparatus 10 includes intermediate conveyance units 26, 28, and 30 between the respective units, and the recording medium 24 is transferred by the intermediate conveyance units 26, 28, and 30. That is, a first intermediate transport unit 26 is provided between the processing liquid application unit 14 and the drawing unit 16, and the recording medium from the processing liquid application unit 14 to the drawing unit 16 by the first intermediate transport unit 26. 24 delivery is performed. Similarly, a second intermediate transport unit 28 is provided between the drawing unit 16 and the drying unit 18. The recording medium 24 is transferred from the drawing unit 16 to the drying unit 18 by the second intermediate transport unit 28. Is done. Further, a third intermediate transport unit 30 is provided between the drying unit 18 and the fixing unit 20, and the third intermediate transport unit 30 transfers the recording medium 24 from the drying unit 18 to the fixing unit 20. Done.

  Hereinafter, each part of the inkjet recording apparatus 10 (the paper feeding unit 12, the processing liquid application unit 14, the drawing unit 16, the drying unit 18, the fixing unit 20, the discharge unit 22, the first to third intermediate conveyance units 26, 28, and 30). ) Will be described.

(Paper Feeder)
The paper feed unit 12 is a mechanism that supplies the recording medium 24 to the treatment liquid application unit 14. The paper feed unit 12 is provided with a paper feed tray 50, and the recording medium 24 is fed from the paper feed tray 50 to the processing liquid application unit 14 one by one.

(Processing liquid application part)
The processing liquid application unit 14 is a mechanism that applies the processing liquid to the recording surface of the recording medium 24. The treatment liquid contains a color material aggregating agent that agglomerates the color material (pigment) in the ink applied by the drawing unit 16, and the ink comes into contact with the color material, the solvent, and the ink by contacting the treatment liquid with the ink. Separation is promoted.

  As shown in FIG. 1, the treatment liquid application unit 14 includes a paper feed drum 52, a treatment liquid drum 54, and a treatment liquid application device 56. The paper feed drum 52 is disposed between the paper feed tray 50 of the paper feed unit 12 and the processing liquid drum 54, and the rotation of the paper feed drum 52 is controlled by a motor driver 176 (see FIG. 4) described later. The recording medium 24 fed from the paper feed unit 12 is received by the paper feed drum 52 and transferred to the processing liquid drum 54. In addition, instead of the paper feed cylinder 52, an intermediate conveyance unit described later may be provided.

  The treatment liquid drum 54 is a drum that holds and rotates and conveys the recording medium 24, and its rotation is driven and controlled by a motor driver 176 (see FIG. 4) described later. Further, the processing liquid drum 54 is provided with a claw-shaped holding means on its outer peripheral surface, and the leading end of the recording medium 24 can be held by this holding means. The recording medium 24 is rotated and conveyed by rotating the treatment liquid drum 54 with the tip held by the holding means. At that time, the recording medium 24 is conveyed with its recording surface facing outward. The processing liquid drum 54 may be provided with a suction hole on the outer peripheral surface thereof and connected to a suction unit that performs suction from the suction hole. As a result, the recording medium 24 can be held in close contact with the peripheral surface of the treatment liquid drum 54.

  A processing liquid coating device 56 is provided outside the processing liquid drum 54 so as to face the peripheral surface thereof. The processing liquid coating device 56 is a device that applies the processing liquid to the recording surface of the recording medium 24. The processing liquid container in which the processing liquid to be applied is stored and the processing liquid in the processing liquid container are partially immersed. And an anix roller and a rubber roller that is pressed against the recording medium 24 on the processing liquid drum 54 and transfers the measured processing liquid to the recording medium 24. According to the processing liquid application device 56, the processing liquid can be applied to the recording medium 24 while being measured. The film thickness of the treatment liquid is desirably sufficiently smaller than the droplet diameter of ink ejected from the inkjet heads 72M, 72K, 72C, 72Y of the drawing unit 16. For example, when the ink droplet ejection amount is 2 pl, the average droplet diameter is 15.6 μm. At this time, when the film thickness of the processing liquid is large, the ink dots float in the processing liquid without contacting the surface of the recording medium 24. Therefore, in order to obtain a landing dot diameter of 30 μm or more when the ink droplet ejection amount is 2 pl, it is desirable that the film thickness of the treatment liquid is 3 μm or less.

  In the present embodiment, the configuration in which the application method using the roller is applied as the method for applying the treatment liquid to the recording surface of the recording medium 24 is exemplified. However, the present invention is not limited to this. For example, a spray method, an ink jet method, etc. Various methods can also be applied.

(Drawing part)
The drawing unit 16 is a mechanism for drawing an image corresponding to an input image by ejecting ink using an ink jet method, and includes a drawing drum 70, a paper holding roller 74, and ink jet heads 72M, 72K, 72C, and 72Y. Yes. The inkjet heads 72M, 72K, 72C, and 72Y correspond to inks of four colors, magenta (M), black (K), cyan (C), and yellow (Y), and are upstream in the rotation direction of the drawing drum 70. Arranged in order from the side.

  The drawing drum 70 is a drum that holds the recording medium 24 on its outer peripheral surface and rotates and conveys the drum. The rotation of the drawing drum 70 is controlled by a motor driver 176 (see FIG. 4) described later. Further, the drawing drum 70 is provided with a claw-shaped holding means on its outer peripheral surface, and the leading end of the recording medium 24 can be held by this holding means. The recording medium 24 is rotated and conveyed by rotating the drawing drum 70 with the tip held by the holding means. At that time, the recording medium 24 is conveyed so that the recording surface faces outward, and ink is applied to the recording surface from the ink jet heads 72M, 72C, 72Y, 72K.

  The sheet pressing roller 74 is a guide member for bringing the recording medium 24 into close contact with the outer peripheral surface of the drawing drum 70, and is disposed at a position facing the outer peripheral surface of the drawing drum 70. Specifically, it is on the downstream side in the conveyance direction of the recording medium 24 (the rotation direction of the drawing drum 70) from the delivery position of the recording medium 24 from the intermediate conveyance unit 26, and from the inkjet heads 72M, 72K, 72C, 72Y. Is also arranged upstream of the recording medium 24 in the transport direction.

  When the recording medium 24 delivered from the intermediate conveyance unit 26 to the drawing drum 70 is rotated and conveyed in a state where the leading end is held by the holding means described above, the recording medium 24 is pressed by the sheet pressing roller 74 and the outer peripheral surface of the drawing drum 70. It is closely attached to. After the recording medium 24 is brought into close contact with the outer peripheral surface of the drawing drum 70 in this way, the recording medium 24 is sent to the print area immediately below the ink jet heads 72M, 72K, 72C, 72Y without being lifted from the outer peripheral surface of the drawing drum 70. It is done.

  The inkjet heads 72M, 72K, 72C, and 72Y are full-line inkjet recording heads (inkjet heads) each having a length corresponding to the maximum width of the image forming area in the recording medium 24. Is formed with a nozzle row in which a plurality of nozzles for ink ejection are arranged over the entire width of the image forming area. Each inkjet head 72M, 72K, 72C, 72Y is fixedly installed so as to extend in a direction orthogonal to the conveyance direction of the recording medium 24 (the rotation direction of the drawing drum 70).

  Corresponding color ink droplets are ejected from the inkjet heads 72M, 72K, 72C, 72Y configured as described above toward the recording surface of the recording medium 24 held on the outer peripheral surface of the drawing drum 70. As a result, the ink comes into contact with the treatment liquid applied to the recording surface in advance by the treatment liquid application unit 14, and the color material (pigment) dispersed in the ink is aggregated to form a color material aggregate. Thereby, the color material flow on the recording medium 24 is prevented, and an image is formed on the recording surface of the recording medium 24. At that time, since the drawing drum 70 of the drawing unit 16 is structurally separated from the processing liquid drum 54 of the processing liquid applying unit 14, the processing liquid may adhere to the ink jet heads 72M, 72K, 72C, 72Y. In addition, the cause of ink ejection failure can be reduced.

  In this example, the configuration of CMYK standard colors (four colors) is illustrated, but the combination of ink colors and the number of colors is not limited to this embodiment, and light ink, dark ink, and special colors are used as necessary. Ink may be added. For example, it is possible to add an inkjet head that discharges light-colored ink such as light cyan and light magenta, and the arrangement order of the color heads is not particularly limited.

(Drying part)
The drying unit 18 is a mechanism for drying moisture contained in the solvent separated by the color material aggregating action, and includes a drying drum 76 and a solvent drying device 78 as shown in FIG.

  The drying drum 76 is a drum that holds the recording medium 24 on the outer peripheral surface thereof and rotates and conveys the rotation. The rotation of the drying drum 76 is controlled by a motor driver 176 (see FIG. 4) described later. Further, the drying drum 76 is provided with a claw-shaped holding means on its outer peripheral surface, and the leading end of the recording medium 24 can be held by this holding means. The recording medium 24 is rotated and conveyed by rotating the drying drum 76 with the tip held by the holding means. At that time, the recording medium 24 is conveyed so that the recording surface faces outward, and the recording surface is dried by the solvent drying device 78. The drying drum 76 may be provided with suction holes on the outer peripheral surface thereof, and may be connected to suction means for performing suction from the suction holes. As a result, the recording medium 24 can be held in close contact with the peripheral surface of the drying drum 76.

  The solvent drying device 78 is disposed at a position facing the outer peripheral surface of the drying drum 76, and the first to fourth halogen heaters 80A to 80D and the first to first halogen heaters 80A to 80D are disposed respectively. 3 hot air ejection nozzles 82A to 82C. That is, at the position facing the outer peripheral surface of the drying drum 76, the first halogen heater 80 </ b> A and the first hot air blowout are sequentially performed from the upstream side in the rotation direction of the drying drum 76 (counterclockwise direction in FIG. 1). A nozzle 82A, a second halogen heater 80B, a second hot air jet nozzle 82B, a third halogen heater 80C, a third hot air jet nozzle 82C, and a fourth halogen heater 80D are provided.

Each of the hot air ejection nozzles 82A to 82C is configured to blow warm air controlled at a predetermined temperature (for example, 50 ° C. to 70 ° C.) toward the recording medium 24 at a constant air volume (12 m ³ / min). Each of the halogen heaters 80A to 80D is controlled to a predetermined temperature (for example, 180 ° C.).

  By the solvent drying device 78 configured in this manner, moisture contained in the ink solvent on the recording surface of the recording medium 24 held on the drying drum 76 is evaporated, and a drying process is performed. At that time, since the drying drum 76 of the drying unit 18 is structurally separated from the drawing drum 70 of the drawing unit 16, in the inkjet heads 72M, 72K, 72C, and 72Y, the head meniscus portion is dried by thermal drying. Ink ejection failure can be reduced. Further, there is a degree of freedom in setting the temperature of the drying unit 18, and an optimal drying temperature can be set.

  In particular, the drying drum 76 used in the present embodiment is configured as a rotary transport body having a predetermined curvature and a surface temperature set to a predetermined temperature, and corresponds to the “first rotary transport body” in the present invention. It is.

  As will be apparent from an evaluation experiment described later, the curvature of the drying drum 76 is preferably in the range of 0.002 (1 / mm) to 0.0033 (1 / mm). If the curvature of the drying drum 76 is less than 0.002 (1 / mm), the correction effect of the cockling is insufficient even if the recording medium 24 is curved, whereas if it exceeds 0.0033 (1 / mm), This is because the recording medium 24 bends more than necessary and does not return to its original state, and is output in a curved state at the time of stacking.

  The surface temperature of the drying drum 76 is set to 50 ° C. or higher. Drying is accelerated by heating from the back surface of the recording medium 24, and image destruction during fixing can be prevented. At this time, it is more effective to provide means for bringing the recording medium 24 into close contact with the outer peripheral surface of the drying drum 76. As means for bringing the recording medium 24 into close contact, various methods such as vacuum adsorption and electrostatic adsorption can be applied.

  The upper limit of the surface temperature of the drying drum 76 is not particularly limited, but from the viewpoint of safety of maintenance work such as cleaning ink adhering to the surface of the drying drum 76 (preventing burns due to high temperature). It is preferably set to 75 degrees or less (more preferably 60 degrees C or less).

  The recording surface of the recording medium 24 faces the outside on the outer peripheral surface of the drying drum (first rotary transport body) 76 configured as described above (that is, the recording surface of the recording medium 24 is convex). Holding in a curved state) and drying while rotating and transporting can prevent the recording medium 24 from wrinkling and floating, and can reliably prevent uneven drying.

(Fixing part)
The fixing unit 20 includes a fixing drum 84, a halogen heater 86, a fixing roller 88, and an inline sensor 90. The halogen heater 86, the fixing roller 88, and the in-line sensor 90 are disposed at positions facing the outer peripheral surface of the fixing drum 84, and are sequentially disposed from the upstream side in the rotation direction of the fixing drum 84 (counterclockwise direction in FIG. 1). The

  The fixing drum 84 is a drum that holds the recording medium 24 on the outer peripheral surface thereof and rotates and conveys the rotation. The rotation of the fixing drum 84 is controlled by a motor driver 176 (see FIG. 4) described later. Further, the fixing drum 84 is provided with a claw-shaped holding unit on the outer peripheral surface thereof, and the leading end of the recording medium 24 can be held by the holding unit. The recording medium 24 is rotated and conveyed by rotating the fixing drum 84 with the tip held by the holding means. At that time, the recording surface of the recording medium 24 is conveyed so that the recording surface faces outward, and the recording surface is subjected to preliminary heating by the halogen heater 86, fixing processing by the fixing roller 88, and inspection by the inline sensor 90. . The fixing drum 84 may be provided with a suction hole on the outer peripheral surface thereof and connected to a suction unit that performs suction from the suction hole. As a result, the recording medium 24 can be held in close contact with the peripheral surface of the fixing drum 84.

  The halogen heater 86 is controlled to a predetermined temperature (for example, 180 ° C.). As a result, the recording medium 24 is preheated.

  The fixing roller 88 is a roller member for heating and pressurizing the dried ink to weld the self-dispersing polymer fine particles in the ink to form a film of the ink, and is configured to heat and press the recording medium 24. The Specifically, the fixing roller 88 is disposed so as to be in pressure contact with the fixing drum 84, and constitutes a nip roller with the fixing drum 84. As a result, the recording medium 24 is sandwiched between the fixing roller 88 and the fixing drum 84 and nipped at a predetermined nip pressure (for example, 0.15 MPa), and a fixing process is performed.

  The fixing roller 88 is configured by a heating roller in which a halogen lamp is incorporated in a metal pipe such as aluminum having good thermal conductivity, and is controlled to a predetermined temperature (for example, 60 to 80 ° C.). By heating the recording medium 24 with this heating roller, thermal energy equal to or higher than the Tg temperature (glass transition temperature) of the latex contained in the ink is applied, and the latex particles are melted. As a result, pressing and fixing are performed on the unevenness of the recording medium 24, and the unevenness of the image surface is leveled to obtain glossiness.

  In the above-described embodiment, only one fixing roller 88 is provided. However, a configuration in which a plurality of fixing rollers 88 are provided in accordance with the image layer thickness and the Tg characteristics of latex particles may be used. Further, the surface of the fixing drum 84 may be controlled to a predetermined temperature (for example, 60 ° C.).

  On the other hand, the in-line sensor 90 is a measuring means for measuring a check pattern, a moisture content, a surface temperature, a glossiness, and the like for an image fixed on the recording medium 24, and a CCD line sensor or the like is applied.

  According to the fixing unit 20 configured as described above, the latex particles in the thin image layer formed by the drying unit 18 are heated and pressurized by the fixing roller 88 and melted, and thus fixed to the recording medium 24. Can be made. Further, according to the fixing unit 20, since the fixing drum 84 is structurally separated from other drums, the temperature setting of the fixing unit 20 is freely set separately from the drawing unit 16 and the drying unit 18. be able to.

  In particular, the fixing drum 84 used in the present embodiment is configured as a rotary conveyance body having a predetermined curvature and a surface temperature set to a predetermined temperature, similar to the drying drum 76 described above. Corresponds to a “rotary transfer body”.

  As will be apparent from an evaluation experiment described later, the curvature of the fixing drum 84 is preferably in the range of 0.002 (1 / mm) to 0.0033 (1 / mm). If the curvature of the fixing drum 84 is less than 0.002 (1 / mm), the correction effect of the cockling is insufficient even if the recording medium 24 is curved, whereas if it exceeds 0.0033 (1 / mm), This is because the recording medium 24 bends more than necessary and does not return to its original state, and is output in a curved state at the time of stacking.

  The surface temperature of the fixing drum 84 is set to 50 ° C. or higher. By heating the recording medium 24 held on the outer peripheral surface of the fixing drum 84 from the back surface, drying is promoted, image destruction at the time of fixing can be prevented, and the image strength is increased by the effect of increasing the image temperature. Can do.

  The upper limit of the surface temperature of the fixing drum 84 is not particularly limited, but is preferably set to 75 degrees or less (more preferably 60 degrees C or less) from the viewpoint of maintainability.

  Further, the fixing roller 88 used in the present embodiment corresponds to a “heating and pressing member” in the present invention, and as can be seen from an evaluation experiment described later, the surface hardness is preferably 71 ° or less. . By making the surface of the fixing roller 88, which is a heating and pressing member, softer, a tracking effect can be expected with respect to the unevenness of the recording medium 24 caused by cockling, and uneven fixing can be more effectively prevented.

  In addition, the moisture in the image is volatilized and the high boiling point organic solvent is concentrated in the image in an appropriate amount (specifically, the high boiling point organic solvent remains in the image at 4% or more of the ink droplet amount). ) Is preferable because the surface of the fixing roller (heating and pressing member) 88 is easily deformed at the time of fixing while having a strength that does not cause image destruction. Further, in the case where the image contains a binder component, the followability of the image can be expected on the surface of the fixing roller 88 as in the case where the image is heated in advance, and fixing unevenness can be prevented more effectively.

  Here, “the state where the high-boiling organic solvent remains in the image at 4% or more of the ink droplet ejection amount” means that the image present on the surface of the recording medium with respect to the ink droplet ejection amount at the timing of the fixing process. The state where the ratio of the residual amount of the high boiling point organic solvent is 4% or more.

  The recording surface of the recording medium 24 faces the outside on the outer peripheral surface of the fixing drum (second rotary conveyance body) 84 configured as described above (that is, the recording surface of the recording medium 24 is convex). By holding it in a curved state and fixing it by heating and pressurizing it while rotating and transporting it, it is possible to correct cockling even when moisture cannot be completely dried and some cockling can occur. It becomes.

  In addition, the surface of the recording medium 24 is stretched against the force for generating irregularities on the surface (recording surface) of the recording medium 24 due to swelling of the pulp fibers, and the irregularities generated by cockling are relaxed and smoothed. Thus, fixing can be performed by the fixing roller (heating and pressing member) 88, so that occurrence of uneven fixing due to cockling can be prevented.

(Discharge part)
As shown in FIG. 1, a discharge unit 22 is provided following the fixing unit 20. The discharge unit 22 includes a discharge tray 92, and a transfer drum 94, a conveyance belt 96, and a tension roller 98 are provided between the discharge tray 92 and the fixing drum 84 of the fixing unit 20 so as to be in contact therewith. It has been. The recording medium 24 is sent to the conveying belt 96 by the transfer drum 94 and discharged to the discharge tray 92.

(Intermediate transport section)
Next, the structure of the first intermediate transport unit 26 will be described. Note that the second intermediate conveyance unit 28 and the third intermediate conveyance unit 30 have the same configuration as the first intermediate conveyance unit 26, and a description thereof will be omitted.

  The first intermediate transport unit 26 mainly includes an intermediate transport body 32 and a transport guide 34. The conveyance guide 34 is a guide member that guides the non-recording surface of the recording medium 24, has an arcuate guide surface having the same curvature as the outer circumferential surface of the intermediate conveyance body 32, and faces the outer circumferential surface of the intermediate conveyance body 32. They are arranged at predetermined intervals at positions.

  The intermediate transport body 32 is a drum for receiving the recording medium 24 from the preceding drum, rotating and transporting the recording medium 24 to the subsequent drum, and is rotatably mounted. The intermediate conveyance body 32 is rotated by a motor (not shown), and the rotation of the intermediate conveyance body 32 is controlled by a motor driver 176 (see FIG. 4) described later. The intermediate transport body 32 includes a claw-shaped holding unit on the outer peripheral surface thereof, and the leading end of the recording medium 24 can be held by the holding unit. The recording medium 24 is rotated and conveyed by rotating the intermediate conveyance body 32 in a state where the tip is held by the holding means. At this time, the recording medium 24 is rotated and conveyed so that the recording surface faces inward and the non-recording surface faces outward.

  In addition, a large number of air outlets are formed on the outer peripheral surface of the intermediate transport body 32 according to a predetermined arrangement pattern, and a drying unit 38 including a halogen heater and a hot air jet nozzle is provided therein. Yes. As a result, warm air is blown out from the air blowing port on the surface of the intermediate conveyance body 32, the recording medium 24 is supported in a floating manner, and the recording surface is dried. Therefore, it is possible to prevent the recording surface of the recording medium 24 from coming into contact with the intermediate conveyance body 32 and to prevent the processing liquid from adhering to the intermediate conveyance body 32. At that time, the recording medium 24 that is levitated and supported by the intermediate conveyance body 32 is conveyed while the non-recording surface is guided by the guide surface.

  According to the first intermediate transport unit 26 configured in this manner, when the recording medium 24 is transported by the intermediate transport body 32, the recording surface can be transported in a non-contact manner, so that the recording surface comes into contact. Therefore, it is possible to avoid image failures that occur. Further, since the warm air is blown out from the intermediate conveyance body 32, the recording surface can be dried while the recording medium 24 is conveyed.

  The recording medium 24 transported by the first intermediate transport unit 26 is transferred to the subsequent drum (that is, the drawing drum 70). At this time, the recording medium 24 is delivered by synchronizing the holding means of the intermediate transport unit 26 and the holding means of the drawing unit 16. The delivered recording medium 24 is held by the drawing drum 70 and rotated and conveyed.

(Inkjet head structure)
Next, the structure of each inkjet head will be described. Since the structures of the inkjet heads 72M, 72K, 72C, 72Y corresponding to the respective colors are common, the inkjet head (hereinafter also simply referred to as “head”) is denoted by reference numeral 150 in the following. And

  2A is a plan perspective view showing a structural example of the head 150, FIG. 2B is an enlarged view of a part thereof, and FIG. 2C is a plan view showing another structural example of the head 150. FIG. FIG. FIG. 3 is a cross-sectional view (a cross-sectional view taken along line 3-3 in FIGS. 2A and 2B) showing a three-dimensional configuration of the ink chamber unit.

  In order to increase the dot pitch formed on the recording medium 24, it is necessary to increase the nozzle pitch in the head 150. As shown in FIGS. 2A and 2B, the head 150 of this example includes a plurality of ink chamber units (recording elements) including nozzles 151 serving as ink discharge ports, pressure chambers 152 corresponding to the nozzles 151, and the like. It has a structure in which droplet discharge elements 153 as units are arranged in a zigzag matrix (two-dimensionally), whereby the head longitudinal direction (direction perpendicular to the conveyance direction of the recording medium 24; main scanning direction) ) To achieve a high density of substantial nozzle intervals (projection nozzle pitch) projected so as to line up along the line.

  The configuration in which one or more nozzle rows are formed in a direction corresponding to the entire width of the recording medium 24 in a direction (main scanning direction) substantially orthogonal to the conveyance direction (sub-scanning direction) of the recording medium 24 is not limited to this example. For example, instead of the configuration of FIG. 2A, as shown in FIG. 2C, short head blocks 150 ′ in which a plurality of nozzles 151 are two-dimensionally arranged are arranged in a staggered manner and connected. The line head having a nozzle row having a length corresponding to the entire width of the recording medium 24 as a whole may be configured by increasing the length of the head. Although not shown, a line head may be configured by arranging short heads in a line.

  The pressure chamber 152 provided corresponding to each nozzle 151 has a substantially square planar shape, the nozzle 151 is provided at one of the diagonal corners, and the supply port 154 is provided at the other. ing. The shape of the pressure chamber 152 is not limited to this example, and the planar shape may have various forms such as a quadrangle (rhombus, rectangle, etc.), a pentagon, a hexagon, other polygons, a circle, and an ellipse.

  Each pressure chamber 152 communicates with a common flow path 155 through a supply port 154. The common flow path 155 communicates with an ink tank (not shown) as an ink supply source, and ink supplied from the ink tank is supplied to each pressure chamber 152 via the common flow path 155.

  A piezoelectric element 158 having an individual electrode 157 is joined to a diaphragm 156 that constitutes a part of the pressure chamber 152 (the top surface in FIG. 3) and also serves as a common electrode. By applying a driving voltage to the individual electrode 157, the piezoelectric element 158 is deformed to change the volume of the pressure chamber 152, and ink is ejected from the nozzle 151 due to the pressure change accompanying this. When the piezoelectric element 158 returns to its original state after ink ejection, new ink is refilled into the pressure chamber 152 from the common flow path 155 through the supply port 154.

  In this example, the piezoelectric element 158 is applied as a means for generating ink ejection force to be ejected from the nozzles 151 provided in the head 150. However, a heater is provided in the pressure chamber 152 and the pressure of film boiling caused by heating of the heater is used. It is also possible to apply a thermal method that ejects ink.

  As shown in FIG. 2B, the ink chamber units 153 having such a structure are arranged in a fixed manner along a row direction along the main scanning direction and an oblique column direction having a constant angle θ that is not orthogonal to the main scanning direction. By arranging a large number of patterns in a lattice pattern, the high-density nozzle head of this example is realized.

  That is, with a structure in which a plurality of ink chamber units 153 are arranged at a constant pitch d along the direction of an angle θ with respect to the main scanning direction, the pitch P of the nozzles projected in the main scanning direction is d × cos θ. Thus, in the main scanning direction, each nozzle 151 can be handled equivalently as a linear arrangement with a constant pitch P. With such a configuration, it is possible to realize a high-density nozzle configuration in which 2400 nozzle rows are projected per inch (2400 nozzles / inch) so as to be aligned in the main scanning direction.

  In the implementation of the present invention, the nozzle arrangement structure is not limited to the illustrated example, and various nozzle arrangement structures such as an arrangement structure having one nozzle row in the sub-scanning direction can be applied.

  Further, the application range of the present invention is not limited to the printing method using a line type head, and a short head that is less than the length in the width direction (main scanning direction) of the recording medium 24 is scanned in the width direction of the recording medium 24. Printing in the width direction is performed, and when printing in one width direction is completed, the recording medium 24 is moved by a predetermined amount in a direction perpendicular to the width direction of the recording medium 24 (sub-scanning direction). A serial method in which printing is performed in the width direction and printing is performed over the entire printing area of the recording medium 24 by repeating this operation may be applied.

(Description of control system)
FIG. 4 is a principal block diagram showing the system configuration of the inkjet recording apparatus 10. The inkjet recording apparatus 10 includes a communication interface 170, a system controller 172, a memory 174, a motor driver 176, a heater driver 178, a print control unit 180, an image buffer memory 182, a head driver 184, and the like.

  The communication interface 170 is an interface unit that receives image data sent from the host computer 186. As the communication interface 170, a serial interface such as USB (Universal Serial Bus), IEEE 1394, Ethernet (registered trademark), a wireless network, or a parallel interface such as Centronics can be applied. In this part, a buffer memory (not shown) for speeding up communication may be mounted. Image data sent from the host computer 186 is taken into the inkjet recording apparatus 10 via the communication interface 170 and temporarily stored in the memory 174.

  The memory 174 is a storage unit that temporarily stores an image input via the communication interface 170, and data is read and written through the system controller 172. The memory 174 is not limited to a memory made of a semiconductor element, and a magnetic medium such as a hard disk may be used.

  The system controller 172 includes a central processing unit (CPU) and its peripheral circuits, and functions as a control device that controls the entire inkjet recording apparatus 10 according to a predetermined program, and also functions as an arithmetic device that performs various calculations. . That is, the system controller 172 controls each part such as the communication interface 170, the memory 174, the motor driver 176, the heater driver 178, the treatment liquid application control unit 196, the drying control unit 197, the fixing control unit 198, etc. In addition to performing communication control between them, read / write control of the memory 174, etc., control signals for controlling the above-described units are generated.

  The memory 174 stores programs executed by the CPU of the system controller 172 and various data necessary for control. Note that the memory 174 may be a non-rewritable storage means, or may be a rewritable storage means such as an EEPROM. The memory 174 is used as a temporary storage area for image data, and is also used as a program development area and a calculation work area for the CPU.

  Various control programs are stored in the program storage unit 190, and the control programs are read and executed in accordance with instructions from the system controller 172. The program storage unit 190 may use a semiconductor memory such as a ROM or an EEPROM, or may use a magnetic disk or the like. An external interface may be provided and a memory card or PC card may be used. Of course, you may provide several recording media among these recording media. The program storage unit 190 may also be used as a recording unit (not shown) for operating parameters.

  The motor driver 176 is a driver that drives the motor 188 in accordance with an instruction from the system controller 172. In FIG. 4, the motors arranged in the respective units in the apparatus are represented by reference numeral 188. For example, the motor 188 shown in FIG. 4 includes a motor for driving the rotation of the paper feed drum 52, the treatment liquid drum 54, the drawing drum 70, the drying drum 76, the fixing drum 84, the transfer drum 94, and the like shown in FIG. A motor for driving the rotation of the intermediate conveyance body 32 of the third intermediate conveyance units 26, 28, and 30 is included.

  The heater driver 178 is a driver that drives the heater 189 in accordance with an instruction from the system controller 172. In FIG. 4, the heaters disposed in the respective units in the apparatus are represented by reference numeral 189. For example, the heater 189 shown in FIG. 4 includes the halogen heaters 80A to 80D of the solvent drying device 78 provided in the drying unit 18 shown in FIG. 1, the halogen heater of the drying unit 38 provided inside the intermediate transport body 32, and the like. It is. Further, a heater for heating the surfaces of the drying drum 76 and the fixing drum 84 shown in FIG. 1 is also included.

  Further, the inkjet recording apparatus 10 includes a processing liquid application control unit 196, a drying control unit 197, and a fixing control unit 198, and in accordance with instructions from the system controller 172, the processing liquid coating device 56 and the solvent drying unit, respectively. The operation of each unit of the device 78 and the fixing roller 88 is controlled.

  The print control unit 180 has a signal processing function for performing various processes and corrections for generating a print control signal from the image data in the memory 174 in accordance with the control of the system controller 172. The generated print data This is a control unit that supplies (dot data) to the head driver 184. Necessary signal processing is performed in the print control unit 180, and the ejection droplet amount (droplet ejection amount) and ejection timing of the head 150 are controlled via the head driver 184 based on the image data. Thereby, a desired dot size and dot arrangement are realized.

  The print control unit 180 is provided with an image buffer memory 182, and image data, parameters, and other data are temporarily stored in the image buffer memory 182 when image data is processed in the print control unit 180. Also possible is an aspect in which the print controller 180 and the system controller 172 are integrated and configured with one processor.

  The head driver 184 generates a drive signal to be applied to the piezoelectric element 158 of the head 150 based on the image data given from the print control unit 180, and drives the piezoelectric element 158 by applying the drive signal to the piezoelectric element 158. Including a driving circuit. The head driver 184 shown in FIG. 4 may include a feedback control system for keeping the driving conditions of the head 150 constant.

  The sensor 185 is various sensors provided in each part in the apparatus, and includes a temperature sensor, a position detection sensor, a pressure sensor, and the like in addition to the inline sensor 90 shown in FIG. The output signal of the sensor 185 is sent to the system controller 172, and the system controller 172 sends a control signal to each part of the apparatus based on the output signal, and each part of the apparatus is controlled.

(Evaluation experiment)
Next, the results of an evaluation experiment conducted to confirm the effect of the present invention will be described.

  The ink and treatment liquid used in this evaluation experiment are as follows.

[Preparation of ink]
(Synthesis of resin dispersant P-1)
According to the following scheme, a resin dispersant P-1 (Chemical Formula 1), which is one embodiment of the resin dispersant (A), was synthesized.

  To a 1000 ml three-necked flask equipped with a stirrer and a condenser tube, 88 g of methyl ethyl ketone was added and heated to 72 ° C. under a nitrogen atmosphere. Here, 50 g of methyl ethyl ketone was mixed with 0.85 g of dimethyl 2,2′-azobisisobutyrate and 60 g of benzyl methacrylate. A solution in which 10 g of methacrylic acid and 30 g of methyl methacrylate were dissolved was dropped over 3 hours. After the completion of the dropwise addition, the reaction was further continued for 1 hour, and then a solution obtained by dissolving 0.42 g of dimethyl 2,2'-azobisisobutyrate in 2 g of methyl ethyl ketone was added, heated to 78 ° C. and heated for 4 hours. The obtained reaction solution was reprecipitated twice in a large excess of hexane, and the precipitated resin was dried to obtain 96 g of a resin dispersant P-1.

  The composition of the obtained resin dispersant P-1 was confirmed by H-NMR, and the weight average molecular weight (Mw) determined by GPC was 44600. Furthermore, when the acid value of this polymer was calculated | required by the method of JIS specification (JISK0070: 1992), it was 65.2 mgKOH / g.

(Synthesis of self-dispersing polymer fine particles B-01)
According to the following scheme, self-dispersing polymer fine particles B-01, which is one embodiment of the self-dispersing polymer fine particles (C), were synthesized.

  That is, 360.0 g of methyl ethyl ketone was charged into a reaction vessel formed of a 2 liter three-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas introduction tube, and the temperature was raised to 75 ° C.

  Next, while maintaining the temperature in the reaction vessel at 75 ° C., 180.0 g of phenoxyethyl acrylate, 162.0 g of methyl methacrylate, 18.0 g of acrylic acid, 72 g of methyl ethyl ketone, and “V-601” (Wako Pure Chemical Industries, Ltd.) (Manufactured) A mixed solution consisting of 1.44 g was added dropwise at a constant speed so that the addition was completed in 2 hours.

  After completion of the dropwise addition, a solution consisting of 0.72 g of “V-601” and 36.0 g of methyl ethyl ketone was added, stirred for 2 hours at 75 ° C., and then a solution consisting of 0.72 g of “V-601” and 36.0 g of isopropanol was added. After stirring at 75 ° C. for 2 hours, the temperature was raised to 85 ° C., and stirring was further continued for 2 hours.

  The weight average molecular weight (Mw) of the obtained copolymer was 64000, and the acid value was 38.9 (mgKOH / g). The weight average molecular weight (Mw) was calculated in terms of polystyrene by gel permeation chromatography (GPC). The columns used were TSKgel SuperHZM-H, TSKgel SuperHZ4000, and TSKgel SuperHZ200 (manufactured by Tosoh Corporation).

  Next, 668.3 g of the copolymer solution was weighed, 388.3 g of isopropanol and 145.7 ml of 1 mol / L NaOH aqueous solution were added, and the temperature in the reaction vessel was raised to 80 ° C. Next, 720.1 g of distilled water was added dropwise at a rate of 20 ml / min to disperse in water. Thereafter, the temperature in the reaction vessel was maintained at 80 ° C. for 2 hours, 85 ° C. for 2 hours, and 90 ° C. for 2 hours under atmospheric pressure, and then the pressure in the reaction vessel was reduced to 913. 7 g was distilled off. As a result, an aqueous dispersion (emulsion) of self-dispersing polymer fine particles (B-01) having a solid content concentration of 28.0% was obtained.

  The chemical structural formula of self-dispersing polymer fine particles B-01 is shown below. The number of each structural unit represents a mass ratio.

(Creation of dispersion of cyan pigment-containing resin particles)
CI Pigment Blue 15: 3 (Phthalocyanine-A220 manufactured by Dainichi Seika Co., Ltd.), 5 parts by mass of the resin dispersant (P-1) shown in Table 1, 42 parts by mass of methyl ethyl ketone, and 1 N aqueous NaOH solution 5.8 parts by mass and 86.9 parts by mass of ion-exchanged water were mixed and dispersed with a bead mill using 0.1 mmΦ zirconia beads for 2 to 6 hours.

  Methyl ethyl ketone was removed from the obtained dispersion at 55 ° C. under reduced pressure, and a part of water was further removed to obtain a dispersion of cyan pigment-containing resin particles having a pigment concentration of 10.2% by mass.

(Preparation of cyan ink composition C-1)
Next, using the obtained dispersion of cyan pigment-containing resin particles and an aqueous dispersion (emulsion) of self-dispersing polymer fine particles (B-01), a water-soluble cyan ink composition C-1 having the following composition was prepared. Prepared.

Dispersion of pigment-containing resin particles: 39.2 parts by mass Aqueous dispersion of self-dispersing fine polymer particles (B-01): 28.6 parts by mass Trioxypropylene glyceryl ether: 6.0 parts by mass (Sanniks GP-250 (Sanyo Chemical Industries, Ltd.)
Tripropylene monomethyl ether: 9.0 parts by mass Orphine E1010 (manufactured by Nissin Chemical Industry Co., Ltd.): 1.0 part by mass Ion exchange water: remainder (Preparation of magenta ink composition M-1)
Pigment Blue 15: 3 (Phthalocyanine A220 manufactured by Dainichi Seika Co., Ltd.) used in the preparation of the cyan pigment dispersion was replaced with Cromophtal Jet Magenta DMQ (PR-122) manufactured by Ciba Specialty Chemicals. Prepared a magenta ink composition M-1 in the same manner as the cyan ink composition.

(Preparation of yellow ink composition Y-1)
Cyan ink, except that Pigment Blue 15: 3 (Phthalocyaniburu-A220 manufactured by Dainichi Seika Co., Ltd.) used in the preparation of the cyan pigment dispersion was replaced with Irgalite Yellow GS (PY74) manufactured by Ciba Specialty Chemicals A yellow ink composition Y-1 was prepared in the same manner as the preparation of the composition.

(Preparation of black ink composition Bk-1)
Similar to the preparation of the cyan ink composition, except that Pigment Blue 15: 3 (Phthalocyanine A220 manufactured by Dainichi Seika Co., Ltd.) used in the preparation of the cyan pigment dispersion was replaced with carbon black MA100 manufactured by Mitsubishi Chemical Corporation. Thus, a black ink composition Bk-1 was prepared.

[Preparation of treatment solution]
The processing liquid was prepared by mixing each component so that it might become the following composition.

Malonic acid (manufactured by Wako Pure Chemical Industries, Ltd.): 10.0 parts by mass Trioxypropylene glyceryl ether: 10.0 parts by mass (Sanniks GP-250 (manufactured by Sanyo Chemical Industries))
Zonyl FSN-100 (manufactured by DuPont): 0.002 parts by mass Ion-exchanged water: remainder [Evaluation method]
Using the same apparatus as the ink jet recording apparatus 10 shown in FIG. 1, the image forming conditions such as the surface temperature and curvature of the drying drum and the fixing drum are appropriately changed, and the cyan ink composition C-1 and magenta ink described above are used. An image was formed on a recording medium (Mitsubishi Paper Co., Ltd., special diamond art double-sided N104.7 g / m ² ) using the composition M-1, the yellow ink composition Y-1, and the black ink composition Bk-1. Then, the image obtained in this way was subjected to stage evaluation with respect to each evaluation item of “image destruction”, “image strength”, “fixing unevenness”, and “stackability”.

  The evaluation criteria for each evaluation item are as follows.

(Evaluation of image destruction)
Sensory evaluation was performed on the image destruction state after fixing and the degree of adhesion of the image to the heating and pressing member.

    ◯: Adhesion to the heating and pressing member is not recognized, and image destruction is not caused.

    Δ: Slight adhesion to the heating and pressing member is observed, but image destruction is not confirmed at a visual level and is within an allowable range.

    X: There is adhesion to the heating and pressing member, and image destruction is confirmed at a visual level.

(Measurement and evaluation of image intensity)
◎… When an undrawn recording medium is placed on the drawing part of the sample, and a load of 400 g / cm ² is applied and rubbed back and forth five times (speed: 20 mm / s), the surface of the sample drawing part does not change visually. .

○: When an undrawn recording medium is placed on the drawing part of the sample, a load of 200 g / cm ² is applied and rubbed back and forth five times (speed: 20 mm / s), the surface of the sample drawing part does not change visually .

Δ: When an undrawn recording medium is overlaid on the drawing area of the sample, a load of 200 g / cm ² is applied, and rubbing back and forth 5 times (speed 20 mm / s), a change in gloss of the sample drawing area is visually observed. However, no change in image density is observed.

X: When a non-drawn recording medium is overlaid on the drawing portion of the sample, a load of 200 g / cm ² is applied and rubbed back and forth 5 times (speed 20 mm / s), a change in image density is visually observed.

(Evaluation of uneven fixing)
A test similar to the above was performed at 10 output samples.

◎… Evaluation value of “Image Strength” is 10 or more ○ ○… Evaluation value of “Image Strength” is 8 or more ○ △… Evaluation value of “Image Strength” is 6 or more to 8 locations Less than x ... Evaluation value of "image strength" is less than 6 and less than 6 places (Evaluation of stacking property)
The stackability of the output sample immediately after fixing was evaluated.

    ○… No problem with stacking.

    Δ: The end is slightly curled, but there is no problem with the stackability.

    ×… The curl is large and there is a problem with stackability.

  Note that “there is a problem with stackability” means that when output samples are stacked, the ends are broken or wrinkled.

The ratio α [%] of the residual amount B [g / m ² ] of the high-boiling organic solvent in the image with respect to the ink droplet ejection amount A [g / m ² ] was determined as follows.

  First, A, B, and α have the relationship shown in the following equation (1).

α = (B / A) × 100 (1)
However, the ink droplet ejection amount A is an average droplet ejection weight per 1 m deposited on the medium surface. The residual amount B of the high-boiling organic solvent is the residual amount of the high-boiling organic solvent in the image (aggregated ink) on the medium surface (not included in the medium). This residual amount B of the high-boiling organic solvent is determined as follows.

(i) Measure the total amount X of high boiling point organic solvent applied to the medium
(ii) The surface of the medium is wiped off using a nonwoven fabric impregnated with water, and the amount of high boiling organic solvent Y contained in the remaining medium is measured. Measurement of the amount of high boiling organic solvent remaining in the image. For this, liquid chromatography was used. And the residual amount B of the high boiling point organic solvent can be calculated | required by following Formula (2).

B = XY (2)
In an evaluation experiment corresponding to Table 3 to be described later, a uniform solid image having a droplet ejection amount A = 13.4 [g / m ² ] was obtained with an ink having a prescription containing 15% by mass of a high-boiling organic solvent of the cyan ink composition C-1. The droplets were ejected (X = 13.4 × 0.15 = 2.01 [g / m ² ]), the image on the medium surface was wiped off at the timing of fixing the image, Y was measured, B was determined, and α was calculated. For example, when X = 2.01 and Y = 1.47, B = 0.54 and α = 4 [%].

[Evaluation results]
The evaluation results in this evaluation experiment are shown in Tables 1 to 3.

  According to the evaluation results shown in Table 1, when the treatment liquid was not applied (Comparative Example 1), the evaluation of “fixing unevenness” and “stackability” was inferior. This is because if ink droplet ejection is performed without applying the treatment liquid, the ink solvent (moisture) excessively permeates into the recording medium, and fixing unevenness due to cockling occurs.

  Further, even when the treatment liquid is applied, when the conditions to which the present invention is applied are not satisfied, specifically, when the surface temperature of the drying drum or the fixing drum is less than 50 ° C. (Comparative Examples 2 to 7) However, the evaluation of “image destruction” and “image strength” was inferior due to insufficient drying or insufficient preheating.

  An image strength evaluation of “−” indicates that the image destruction evaluation is “x” and the image strength evaluation is impossible. In addition, when the evaluation of the fixing unevenness is “−”, the evaluation of the image strength is “Δ” or less, and the fixing unevenness cannot be evaluated.

  Further, when the curvature of each drum does not satisfy the range of 0.002 (1 / mm) or more and 0.0033 (1 / mm) or less (Comparative Examples 8 to 10), “fixing unevenness” or “stacking property” Evaluation of was inferior. If the curvature of each drum is less than 0.002 (1 / mm), cockling is likely to occur and uneven fixing occurs. On the other hand, if it exceeds 0.0033 (1 / mm), the recording medium is wound and curled. This is because a problem arises in stackability.

  On the other hand, when the treatment liquid is applied and the conditions to which the present invention is applied are satisfied, specifically, the surface temperature of each drum is 55 ° C. or more, and the curvature of each drum is 0.002. In the case of (1 / mm) or more and 0.0033 (1 / mm) or less (Examples 1 to 10), “image destruction”, “image strength”, “fixing unevenness”, “stackability” Good results were obtained for all evaluation items.

  Further, according to the evaluation results shown in Table 2, when the surface hardness of the fixing roller is 71 ° or less (Examples 14 to 16), the surface hardness exceeds 71 ° (Examples 11 to 13). As a result, the evaluation of “image strength” was good. Furthermore, when the surface hardness of the fixing roller was 64 ° or less (Example 16), the evaluation of “image strength” and “fixing unevenness” was good. By softening the surface of the fixing roller in this manner, there is an effect of following the unevenness of the image caused by aggregation, promoting the formation of a film on the entire image, and improving the “image strength”. Furthermore, it is possible to expect a follow-up effect on unevenness due to macro paper undulation caused by cockling, and "fixing unevenness" can be prevented.

  Further, according to the evaluation results shown in Table 3, when the high boiling point organic solvent remains in the image at 4% or more of the ink droplet amount, the time from drawing to the start of drying is within 3 seconds. In (Examples 17 to 22, 24 to 29), the evaluation of “image strength” and “fixing unevenness” was better than in the case of exceeding 3 seconds (Examples 23 and 30). By performing drying immediately after drawing (ie, within 3 seconds), the ink solvent (moisture) can be volatilized before penetrating into the recording medium, making it easier to prevent cockling and fixing unevenness. It can be prevented more effectively.

  That is, as the “residual amount of the high-boiling solvent” is larger or the “time from drawing to drying start” is shorter, the image becomes softer, and the image surface becomes easier to follow the surface of the fixing roller at the time of fixing. The smaller the “surface hardness”, the easier the roller surface follows the image surface during fixing, the effective contact heating area between the roller and the image increases, the fixing efficiency is improved, and the “image strength” is improved.

  Note that “the time from drawing to the start of drying is within 3 seconds” means that when the time when the leading edge of the recording medium enters the drawing portion (image forming portion) is 0 seconds, the leading edge of the recording medium is in the drying portion. This means that the time interval until entry is within 3 seconds. More specifically, when the ink droplet landing time on the surface of the recording medium is 0 second, the time interval until the ink droplet landing position on the recording medium enters the drying portion is within 3 seconds. That means.

  According to the ink jet recording apparatus 10 of the present embodiment, the ink is thickened by an agglomeration reaction with the treatment liquid, the penetration of the ink solvent into the recording medium 24 is delayed, and cockling that occurs before the drying is performed is effective. Can be prevented. Furthermore, the drying can be performed more effectively by performing the drying in a state where the ink solvent is unevenly distributed and stays on the recording surface of the recording medium 24.

  In particular, in the present embodiment, the recording medium 24 is held on a drying drum 76 having a predetermined curvature and having a surface heated to a predetermined temperature so that the recording surface is curved so that the recording surface is convex. By drying the recording medium 24 while rotating and transporting the recording medium 24 by rotating 76, the recording medium 24 can be prevented from being wrinkled or lifted, and drying unevenness caused by these can be surely prevented. Further, by heating the surface temperature of the drying drum 76 to a predetermined temperature, the recording medium 24 can also be heated from the back surface, and drying can be promoted, and image destruction during fixing can be prevented.

  Further, the recording medium 24 is held on a fixing drum 84 having a predetermined curvature and the surface heated to a predetermined temperature so that the recording surface is curved, and recording is performed by rotation of the fixing drum 84. By heating and pressurizing the medium 24 while rotating and conveying, the ink solvent (moisture) cannot be completely dried, and even in a state where some cockling can occur, cockling can be corrected. In particular, it can be fixed by the fixing roller 88 in a state where the surface of the recording medium 24 is stretched and the unevenness generated by cockling is relaxed and smoothed against the force of generating unevenness on the paper surface due to swelling of the pulp fibers. Therefore, uneven fixing due to cockling can be prevented.

  Further, in the present embodiment, the drying drum (first rotary transport body) 76 where the drying process is performed and the fixing drum (second rotary transport body) 84 where the fixing process is performed are separately configured. The curvature and surface temperature of each of the drums 76 and 84 can be optimized according to each process, and fixing unevenness due to cockling can be more effectively prevented.

  In the present embodiment, as described above, the drying drum 76 that performs the drying process and the fixing drum 84 that performs the fixing process are separated from each other. However, in the present invention, each of the drums 76 and 84 is not necessarily separate. It is not necessary to be configured. For example, in the present embodiment, when the curvature and the surface temperature of the drying drum 76 and the fixing drum 84 are the same, the drying process and the fixing process may be performed by a single rotary conveyance body (common drum). In this case, it is possible to reduce the size and cost of the apparatus.

  Although the ink jet recording apparatus and the recording method of the present invention have been described in detail above, the present invention is not limited to the above examples, and various improvements and modifications can be made without departing from the spirit of the present invention. Of course it is good.

Overall configuration diagram showing outline of inkjet recording apparatus Plane perspective view showing a configuration example of the head Sectional view showing the three-dimensional configuration of the ink chamber unit 1 is a principal block diagram showing the system configuration of the ink jet recording apparatus shown in FIG.

  DESCRIPTION OF SYMBOLS 10 ... Inkjet recording device, 12 ... Paper feed part, 14 ... Processing liquid provision part, 16 ... Drawing part, 18 ... Drying part, 20 ... Fixing part, 22 ... Discharge part, 24 ... Recording medium, 26, 28, 30 ... Intermediate transport unit 54 ... Processing liquid drum 56 ... Processing liquid coating device 70 ... Drawing drum 72M, 72K, 72C, 72Y ... Inkjet head 74 ... Paper suppression roller 76 ... Drying drum 78 ... Solvent drying device 84 ... fixing drum, 88 ... fixing roller, 90 ... inline sensor, 172 ... system controller, 176 ... motor driver, 178 ... heater driver, 180 ... print control unit, 184 ... head driver, 196 ... processing liquid application control unit, 197 ... Drying control unit, 198 ... Fixing control unit

Claims (7)

A treatment liquid application unit that applies a treatment liquid containing a component that aggregates the coloring material in the ink to the recording medium;
An image forming unit that forms an image on the recording medium by ejecting the ink onto the recording medium to which the treatment liquid is applied;
The recording medium has a rotary conveyance body that holds the recording medium in a curved state so that the recording surface is convex, and the recording medium is rotated and conveyed while the recording medium is held on the rotary conveyance body. A post-processing unit that performs a drying process of an image formed on a medium and a fixing process by a heating and pressing member,
Inkjet recording characterized in that the surface temperature of the rotary carrier is 50 ° C. or more and the curvature of the rotary carrier is 0.002 (1 / mm) or more and 0.0033 (1 / mm) or less. apparatus. The inkjet recording apparatus according to claim 1, wherein
The post-processing unit includes a drying unit and a fixing unit,
The drying unit includes a first rotary transport body that holds the recording medium in a curved state so that a recording surface of the recording medium becomes a convex side, and is held by the first rotary transport body. A processing unit that performs a drying process on an image formed on the recording medium while rotating and transporting the recording medium;
The fixing unit includes a second rotary conveyance body that holds the recording medium in a curved state so that a recording surface of the recording medium becomes a convex side, and is held by the second rotary conveyance body A processing unit that performs a fixing process with a heating and pressing member on an image formed on the recording medium while rotating and transporting the recording medium;
The first and second rotary transport bodies have a surface temperature of 50 ° C. or more, and the curvature of the rotary transport body is 0.002 (1 / mm) or more and 0.0033 (1 / mm) or less. An ink jet recording apparatus. The inkjet recording apparatus according to claim 1 or 2,
An ink jet recording apparatus, wherein the heat and pressure member has a surface hardness of 71 ° or less. The inkjet recording apparatus according to any one of claims 1 to 3,
In the inkjet recording apparatus, the fixing process is performed by heating and pressurizing in a state in which a high boiling point organic solvent remains in an image at 4% or more of the ink droplet ejection amount. The inkjet recording apparatus according to any one of claims 1 to 4,
In the ink jet recording apparatus, the drying process is performed within 3 seconds after an image is formed on the recording medium in the image forming unit. A treatment liquid application step of applying to the recording medium a treatment liquid containing a component that agglomerates the colorant in the ink;
An image forming step of forming an image on the recording medium by ejecting the ink onto the recording medium provided with the treatment liquid;
The recording medium is held on a rotary conveyance body in a curved state so that the recording surface of the recording medium is a convex side, and the recording medium held on the rotary conveyance body is rotated and conveyed on the recording medium. And a post-processing step of performing a drying process of the image formed on and a fixing process by a heating and pressing member,
Inkjet recording characterized in that the surface temperature of the rotary carrier is 50 ° C. or more and the curvature of the rotary carrier is 0.002 (1 / mm) or more and 0.0033 (1 / mm) or less. Method. The inkjet recording method according to claim 6, wherein
The post-processing step includes a drying step and a fixing step,
In the drying step, the recording medium is held on the first rotary conveyance body in a state where the recording surface of the recording medium is curved so as to be a convex side, and the recording held on the first rotary conveyance body is performed. It is a processing step of performing a drying process of an image formed on the recording medium while rotating and conveying the medium,
In the fixing step, the recording medium is held on a second rotary conveyance body in a state where the recording surface of the recording medium is curved so as to be a convex side, and the recording held on the second rotary conveyance body It is a processing step of performing a fixing process by a heating and pressing member for an image formed on the recording medium while rotating and conveying the medium,
The first and second rotary transport bodies have a surface temperature of 50 ° C. or more, and the curvature of the rotary transport body is 0.002 (1 / mm) or more and 0.0033 (1 / mm) or less. An ink jet recording method.