JP2008105375A - Ink-jet recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink-jet recording method that suppresses ink bleeding with respect to various unabsorbent media to be recorded, achieves high image uniformity, and also suppresses line-width unevenness or color unevenness while achieving excellent image fixing properties. <P>SOLUTION: The ink-jet recording method uses: a coloring liquid composition containing at least a coloring agent, a polymerizable compound and a photopolymerization initiator; and an undercoating liquid composition containing at least a radical polymerizable compound and a hotopolymerization initiator, and the coloring liquid composition contains two different photopolymerization initiators having different spectral absorption spectrums. The method includes: a step of imparting the undercoating liquid composition onto a medium to be recorded; a step of imparting the coloring-liquid composition onto the medium to be recorded; a first exposure step of semi-curing the coloring liquid composition and/or the undercoating liquid composition; and a second exposure step of completely curing the coloring-liquid composition and/or the undercoating-liquid composition. The spectral energy distribution of a first exposure light source is different from that of a second exposure light source. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an inkjet recording method, and more particularly, to an inkjet recording method suitable for forming a high-quality image at high speed.

  An ink jet system that ejects ink in droplets from an ink ejection port is used in many printers because it is small and inexpensive, and can form an image without contact with a recording medium. Among these ink jet methods, the piezo ink jet method that ejects ink using deformation of piezoelectric elements and the thermal ink jet method that ejects ink droplets by utilizing the boiling phenomenon of ink due to thermal energy achieve high resolution and high printability. It has the feature of being excellent.

  Currently, high speed, high image quality, and fixability to recording media are important issues when ink is ejected onto non-absorbing recording media such as plain paper or plastic by inkjet printers. ing.

Ink jet recording is a method in which ink droplets are ejected according to image data, and lines are formed on the recording medium or images are formed on the recording medium. When recording, if it takes time to dry the droplets after droplet ejection or penetrate into the recording medium, the image tends to bleed, and mixing between adjacent ink droplets on the recording medium This causes a problem in practical use such as the formation of sharp images and hinders the formation of sharp images. When mixing between droplets, the adjacent droplets that have been ejected coalesce and movement of the droplets occurs. Uniformity occurs, and color unevenness occurs when a colored surface is drawn (hereinafter referred to as droplet ejection interference). In addition, since the degree of non-uniform line width and color unevenness on the colored surface varies depending on the ink absorbability and wettability of the surface of the recording medium, various recording media can be used even if the ink used and its discharge conditions are constant. There was also a problem that the images were different.
In addition to the above problems, an image recorded on a non-absorbable recording medium is also problematic in terms of image fixability, such as being easily peeled off and inferior to scratching.

Various techniques have been proposed so far to solve the above problems.
For example, in order to give a high-definition drawing property, there is one that uses a reactive two-component ink and causes both to react on the recording medium. For example, a liquid having a basic polymer is attached. Then, after applying a method of recording an ink containing an anionic dye (see, for example, Patent Document 1) or a liquid composition containing a cationic substance, an ink containing an anionic compound and a colorant is applied. A method (for example, refer to Patent Document 2) is disclosed.
In addition, UV curable ink is applied as the ink, and UV curable color ink dots ejected onto the recording medium are irradiated with ultraviolet rays in accordance with their respective ejection timings to increase the viscosity and adjacent dots do not mix with each other. There has been proposed an ink jet recording method in which pre-curing is carried out to a certain extent, followed by further UV-irradiation to perform main curing (see, for example, Patent Document 5).
In addition, a radiation-curable white ink is uniformly applied as an undercoat layer on a transparent or translucent non-absorbable recording medium, solidified or thickened by irradiation, and then a radiation-curable color ink set is used. There has been proposed a technique (for example, see Patent Documents 3 and 4) that improves the problem of color ink visibility, bleeding, and the difference in image between various recording media. In addition, a technique for applying a substantially transparent actinic ray curable ink by an inkjet head instead of the radiation curable white ink has been proposed (for example, see Patent Document 6).

Japanese Unexamined Patent Publication No. 63-60783 JP-A-8-174997 JP 2003-145745 A JP 2004-42525 A JP 2004-42548 A JP 2005-96254 A

  However, the method described in Patent Document 2 can avoid the problem of droplet ejection interference and bleeding on a specific substrate, but is insufficient from the viewpoint of image fixability. On the other hand, in the method described in Patent Document 5, bleeding is suppressed and image fixability is improved. However, there remains a problem that images are different between various recording media. Insufficient line width and color unevenness due to mixing are insufficient. In addition, the methods described in Patent Documents 3 and 4 are insufficient for eliminating non-uniform line width and color unevenness caused by mixing between droplets. Furthermore, the method described in Patent Document 6 still has problems such as non-uniform line width and color unevenness due to mixing between droplets.

  The present invention has been made in view of the above problems, and even when various non-absorbable recording media are used, ink bleeding is effectively suppressed, and image uniformity between various recording media is achieved. An object of the present invention is to provide an ink jet recording method that is high, can suppress the occurrence of non-uniform line width and color unevenness due to droplet ejection interference, and is excellent in fixability of an image to a recording medium.

The above problem has been solved by the following means <1>. It is shown below with <2>-<10> which are preferable embodiments.
<1> Using a colored liquid composition containing at least a colorant, a polymerizable compound and a photopolymerization initiator, and an undercoat liquid composition containing at least a radical polymerizable compound and a photopolymerization initiator, (1) The colored liquid composition contains at least two kinds of photopolymerization initiators having different spectral absorption spectra. (2) The recording method includes applying the undercoat liquid composition onto a recording medium; and the colored liquid composition. A step of applying an object onto a recording medium, a first exposure step of semi-curing the colored liquid composition and / or the undercoat liquid composition, and the colored liquid composition and the undercoat liquid composition completely. And (3) the spectral energy distribution of the first exposure light source is different from the spectral energy distribution of the second exposure light source. The ink jet recording method,
<2> The inkjet recording method according to <1>, wherein the step of applying the undercoat liquid composition onto the recording medium is performed prior to the step of applying the colored liquid composition onto the recording medium.
<3> The intensity of light at a wavelength of 255 nm of the first exposure light source is 1 mW / cm ² or less, and the intensity of light at a wavelength of 255 nm of the second exposure light source is 10 mW / cm ² or more. <1> or the inkjet recording method according to <2>,
<4> The intensity of light at a wavelength of 365 nm of the first exposure light source is 10 mW / cm ² or more, and the intensity of light at a wavelength of 365 nm of the second exposure light source is 10 mW / cm ² or more <1> to <3> The inkjet recording method according to any one of
<5> The inkjet recording method according to any one of <1> to <4>, wherein the first exposure light source is an LED light source,
<6> The inkjet recording method according to any one of <1> to <5>, wherein the second exposure light source is a metal halide lamp or a mercury lamp.
<7> The colored liquid composition contains a photopolymerization initiator A and a photopolymerization initiator B, and when the photopolymerization initiator A is dissolved in an acetonitrile solution at a concentration of 0.1% by weight, When the absorbance of the solution at a wavelength of 365 nm (optical path length: 1 cm) is 0.2 or less and the photopolymerization initiator B is dissolved in an acetonitrile solution at a concentration of 0.1% by weight, The inkjet recording method according to any one of <1> to <6>, wherein the absorbance (optical path length: 1 cm) with respect to a wavelength of 365 nm is 0.3 or more,
<8> When at least one of the photopolymerization initiators contained in the colored liquid composition is dissolved in an acetonitrile solution at a concentration of 0.1% by weight, the absorbance (optical path length) of the solution with respect to a wavelength of 255 nm 1 cm) is 0.3 or more, <1> to <7> The inkjet recording method according to any one of the above,
<9> The inkjet recording method according to any one of <1> to <8>, wherein the polymerizable compound is a radical polymerizable compound;
<10> The inkjet recording method according to any one of <1> to <9>, wherein the colored liquid composition has a surface tension larger than that of the undercoat liquid composition.

  According to the present invention, even when various non-absorbable recording media are used, ink bleeding is effectively suppressed, image uniformity between various recording media is high, and due to mixing between droplets. It is possible to provide an ink jet recording method that can suppress the occurrence of non-uniform line width, color unevenness, and the like, and has excellent fixability of an image to a recording medium.

  The inkjet recording method of the present invention comprises at least a colored liquid composition containing a colorant, a polymerizable compound and a photopolymerization initiator (hereinafter also referred to as “colored liquid” in the present invention), at least a radical polymerizable compound, and An undercoat liquid composition containing a photopolymerization initiator (hereinafter also referred to as “undercoat liquid” in the present invention), and (1) the colored liquid composition contains at least photopolymerization initiators having different spectral absorption spectra. (2) The recording method includes the step of applying the undercoat liquid composition onto a recording medium, the step of applying the colored liquid composition onto a recording medium, and the colored liquid composition. And / or less the first exposure step of semi-curing the undercoat liquid composition and the second exposure step of completely curing the colored liquid composition and the undercoat liquid composition. Also it includes, and wherein (3) the spectral energy distribution of the first exposure light source and the spectral energy distribution of the second exposure light source are different.

From the viewpoint of enhancing the color reproducibility of the image, the undercoat liquid composition is preferably a transparent liquid composition that does not substantially contain a colorant, or a white liquid composition that contains a white pigment. A transparent liquid composition is preferred.
The “substantially free of colorant” excludes the use of a trace amount of blue pigment for correcting the yellowing of the recording medium and the inclusion of a trace amount of colorant that is invisible. is not. The allowable amount is preferably 1% by weight or less, particularly preferably not contained, based on the total weight of the undercoat liquid composition.
Moreover, the white pigment which can be preferably used is described in the item of (colorant).
Hereinafter, the present invention will be described in detail.

(Colored liquid composition and undercoat liquid composition)
The colored liquid composition and the undercoat liquid composition that can be used in the present invention are liquid compositions that can be cured by irradiation with radiation.
The term “radiation” as used in the present invention is not particularly limited as long as it is an actinic radiation that can impart energy capable of generating an initiation species in the ink composition by irradiation, and is broadly α-ray, γ-ray, X-ray. , Ultraviolet rays (UV), visible rays, electron beams, and the like. Among them, ultraviolet rays and electron beams are preferable from the viewpoint of curing sensitivity and device availability, and ultraviolet rays are particularly preferable. Therefore, the colored liquid composition and the undercoat liquid composition in the present invention are preferably a colored liquid composition and an undercoat liquid composition that can be cured by irradiating ultraviolet rays as radiation.

<Polymerizable compound>
The colored liquid composition and the undercoat liquid composition that can be used in the present invention contain at least a polymerizable compound.
The polymerizable compound that can be used in the present invention is preferably an addition polymerizable compound, and more preferably a radical polymerizable compound. In addition, as the polymerizable compound that can be used in the present invention, plural kinds of polymerizable compounds may be used, and it is also preferable to use a radical polymerizable compound and a cationic polymerizable compound in combination.

  As the radical polymerizable compound, at least an acrylate compound is preferably used, and a cyclic acrylate compound is more preferably used. Examples of the cyclic group possessed by the cyclic acrylate compound include an aliphatic ring group, a heterocyclic group and an aromatic ring group, preferably an aliphatic ring group. Among aliphatic ring groups, a condensed ring in which two or more rings are condensed. More preferably, it is a polycyclic group.

In the present invention, the polymerizable compound contained in the colored liquid composition and the undercoat liquid composition may be a known polymerization reactive material such as a radical polymerization reactive material, a cationic polymerization reactive material, or a dimerization reactive material, or a crosslinking property. Material can be applied.
Examples of the polymerizable compound that can be used in the present invention include an addition polymerizable compound having at least one ethylenically unsaturated double bond, an epoxy compound, an oxetane compound, an oxirane compound, and a high compound having a maleimide group in the side chain. Molecular compounds, cinnamyl groups having unsaturated double bonds capable of photodimerization adjacent to aromatic nuclei, and polymer compounds having side chains of cinnamylidene groups, chalcone groups, etc., among which at least one ethylenic group Addition polymerizable compounds such as an addition polymerizable compound having a saturated double bond, an epoxy compound, an oxetane compound and an oxirane compound can be preferably used.

The addition polymerizable compound having at least one ethylenically unsaturated double bond is preferably selected from compounds (monofunctional or polyfunctional compounds) having at least one terminal ethylenically unsaturated bond, more preferably two or more. Is.
Specifically, it can be appropriately selected from those widely known in the industrial field according to the present invention, for example, monomers, prepolymers, that is, dimers, trimers and oligomers, or mixtures thereof, and those Those having a chemical form such as a copolymer of
Specifically, the polymerizable compound preferably has a polymerizable group such as an acryloyl group, a methacryloyl group, an allyl group, a vinyl group, or an internal double bond group (such as maleic acid) in the molecule. A compound having an acryloyl group or a methacryloyl group is preferred in that it can cause a curing reaction.

  Examples of the polyfunctional compound include a vinyl group-containing aromatic compound, an (meth) acrylate that is an ester of a divalent or higher alcohol and (meth) acrylic acid, an amide of a divalent or higher amine and (meth) acrylic acid. It can be obtained by combining (meth) acrylamide, polyester (meth) acrylate obtained by introducing (meth) acrylic acid into polycaprolactone, ester obtained by combining polybasic acid and dihydric alcohol, or coupling of alkylene oxide and polyhydric alcohol. Polyether (meth) acrylate in which (meth) acrylic acid is introduced into ether, (meth) acrylic acid is introduced into epoxy resin, or epoxy (meth) obtained by reacting a bivalent or higher alcohol with an epoxy-containing monomer Acrylate, urethane acrylate with urethane bond, amino resin Relate, acrylic resin acrylate, alkyd resin acrylate, spirane resin acrylate, silicone resin acrylate, reaction product of unsaturated polyester and photopolymerizable monomer, reaction product of waxes and polymerizable monomer, and the like. .

Among them, (meth) acrylate, polyester (meth) acrylate, polyether (meth) acrylate, epoxy acrylate, urethane acrylate, acrylic resin acrylate, silicone resin acrylate, reaction product of unsaturated polyester and the photopolymerizable monomer are preferable. Acrylate, polyester acrylate, polyether acrylate, epoxy acrylate, and urethane acrylate are particularly preferable.
In addition, in this specification, (meth) acrylic acid shows that it can take both acrylic acid and methacrylic acid.

  Specific examples of the polyfunctional compound include divinylbenzene, 1,3-butanediol diacrylate, 1,6-hexanediol diacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, dipentaerythritol hexaacrylate, 1, 6-acryloylaminohexane, hydroxypivalate ester neopentyl glycol diacrylate, polyester acrylate having a (meth) acryloyl group at the molecular chain end of a polyester having a molecular weight of 500 to 30,000 comprising a dibasic acid and a dihydric alcohol, polyethylene Contains glycol diacrylate, epoxy acrylate having a bisphenol (A or S, F) skeleton and a molecular weight of 450 to 30,000, and a skeleton of phenol novolac resin. Epoxy acrylates having a molecular weight 600～30,000, the reaction product of a polyvalent isocyanate and a hydroxyl group (meth) acrylate monomer having a molecular weight 350～30,000, and urethane modified products having urethane bonds and the like in the molecule.

  Examples of monofunctional compounds include (meth) acrylate, styrene, acrylamide, vinyl group-containing monomers (vinyl esters, vinyl ethers, N-vinylamide, etc.), (meth) acrylic acid, and the like. , Acrylamide, vinyl esters and vinyl ethers are preferable, and (meth) acrylate and acrylamide are particularly preferable.

  Specific examples of the monofunctional compound include hydroxyethyl acrylate, glycidyl acrylate, tetrahydrofurfuryl acrylate, dicyclopentenyl acrylate, 2-acryloyloxyethyl phosphate, allyl acrylate, N, N-dimethylaminoethyl acrylate, N, N- Dimethylacrylamide, N, N-diethylaminopropylacrylamide, N-butoxymethylacrylamide, acryloylmorpholine, 2-hydroxyethyl vinyl ether, N-vinylformamide, N-vinylacetamide, 2-cyclohexylcarbamoyloxyethyl acrylate, polybutyl acrylate moiety on ester An acrylate having a polydimethylsiloxane moiety in an ester

  The polymerizable compound may be unsubstituted or may have a substituent, and examples of the substituent that can be introduced include a halogen atom, a hydroxyl group, an amide group, and a carboxyl group.

  Examples of the cationic polymerizable compound used in the present invention include JP-A-6-9714, JP-A-2001-31892, 2001-40068, 2001-55507, and 2001-310938. , Epoxy compounds, vinyl ether compounds, oxetane compounds and the like described in each publication such as JP 2001-310937 A and 2001-220526 Gazette.

  Examples of the epoxy compound that can be used in the present invention include aromatic epoxides and alicyclic epoxides.

  Examples of monofunctional epoxy compounds that can be used in the present invention include, for example, phenyl glycidyl ether, p-tert-butylphenyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, allyl glycidyl ether, 1,2-butylene oxide, 1,3-butadiene monooxide, 1,2-epoxydodecane, epichlorohydrin, 1,2-epoxydecane, styrene oxide, cyclohexene oxide, 3-methacryloyloxymethylcyclohexene oxide, 3-acryloyloxymethylcyclohexene oxide, 3 -Vinylcyclohexene oxide etc. are mentioned.

Examples of polyfunctional epoxy compounds that can be used in the present invention include, for example, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, brominated bisphenol A diglycidyl ether, and brominated bisphenol F. Diglycidyl ether, brominated bisphenol S diglycidyl ether, epoxy novolac resin, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether, 3,4-epoxycyclohexylmethyl-3 ′ , 4′-epoxycyclohexanecarboxylate, bis (3,4-epoxycyclohexylmethyl) adipate, vinylcyclohexene oxide, 4-vinyl epoxy Rhohexane, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 3,4-epoxy-6-methylcyclohexyl-3 ′, 4′-epoxy-6′-methylcyclohexanecarboxylate, methylenebis (3,4 -Epoxycyclohexane), dicyclopentadiene diepoxide, di (3,4-epoxycyclohexylmethyl) ether of ethylene glycol, ethylene bis (3,4-epoxycyclohexanecarboxylate), dioctyl epoxyhexahydrophthalate, epoxyhexahydrophthal Di-2-ethylhexyl acid, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether , Polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ethers, 1,13-tetradecadiene dioxide, limonene dioxide, 1,2: 7,8-diepoxyoctane, 1,2: 5,6-diepoxy And cyclooctane.
Among these epoxy compounds, aromatic epoxides and alicyclic epoxides are preferable from the viewpoint of excellent curing speed, and alicyclic epoxides are particularly preferable.

  Examples of monofunctional vinyl ethers that can be used in the present invention include, for example, methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, n-butyl vinyl ether, t-butyl vinyl ether, 2-ethylhexyl vinyl ether, n-nonyl vinyl ether, lauryl vinyl ether, cyclohexyl. Vinyl ether, cyclohexyl methyl vinyl ether, 4-methylcyclohexyl methyl vinyl ether, benzyl vinyl ether, dicyclopentenyl vinyl ether, 2-dicyclopentenoxyethyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, butoxyethyl vinyl ether, methoxyethoxyethyl vinyl ether, ethoxyethoxy Ethyl vinyl ether, methoxypoly Tylene glycol vinyl ether, tetrahydrofurfuryl vinyl ether, 2-hydroxyethyl vinyl ether, 2-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 4-hydroxymethylcyclohexyl methyl vinyl ether, diethylene glycol monovinyl ether, polyethylene glycol vinyl ether, chloroethyl vinyl ether, chlorobutyl vinyl ether Chloroethoxyethyl vinyl ether, phenylethyl vinyl ether, phenoxypolyethylene glycol vinyl ether, and the like.

Examples of the polyfunctional vinyl ether that can be used in the present invention include, for example, ethylene glycol divinyl ether, diethylene glycol divinyl ether, polyethylene glycol divinyl ether, propylene glycol divinyl ether, butylene glycol divinyl ether, hexanediol divinyl ether, and bisphenol A. Divinyl ethers such as alkylene oxide divinyl ether and bisphenol F alkylene oxide divinyl ether; trimethylol ethane trivinyl ether, trimethylol propane trivinyl ether, ditrimethylol propane tetravinyl ether, glycerin trivinyl ether, pentaerythritol tetravinyl ether, dipentaerythritol pentavinyl ether , Dipentaerythritol hexavinyl ether, ethylene oxide-added trimethylolpropane trivinyl ether, propylene oxide-added trimethylolpropane trivinyl ether, ethylene oxide-added ditrimethylolpropane tetravinyl ether, propylene oxide-added ditrimethylolpropane tetravinyl ether, ethylene oxide-added pentaerythritol tetravinyl ether And polyfunctional vinyl ethers such as vinyl ether, propylene oxide-added pentaerythritol tetravinyl ether, ethylene oxide-added dipentaerythritol hexavinyl ether, and propylene oxide-added dipentaerythritol hexavinyl ether.
As the vinyl ether compound, a di- or trivinyl ether compound is preferable from the viewpoints of curability, adhesion to a recording medium material, surface hardness, and the like, and a divinyl ether compound is particularly preferable.

The oxetane compound that can be used in the present invention refers to a compound having an oxetane ring, and is a known oxetane as described in JP-A Nos. 2001-220526, 2001-310937, and 2003-341217. A compound can be arbitrarily selected and used.
The compound having an oxetane ring that can be used in the colored liquid composition and the undercoat liquid composition in the present invention is preferably a compound having 1 to 4 oxetane rings in the structure. By using such a compound, it becomes easy to maintain the viscosity of the colored liquid composition and the undercoat liquid composition in a good handling range, and it is possible to obtain high adhesion to the recording medium. it can.

  Examples of monofunctional oxetanes that can be used in the present invention include, for example, 3-ethyl-3-hydroxymethyloxetane, 3- (meth) allyloxymethyl-3-ethyloxetane, (3-ethyl-3-oxetanylmethoxy) ) Methylbenzene, 4-fluoro- [1- (3-ethyl-3-oxetanylmethoxy) methyl] benzene, 4-methoxy- [1- (3-ethyl-3-oxetanylmethoxy) methyl] benzene, [1- ( 3-ethyl-3-oxetanylmethoxy) ethyl] phenyl ether, isobutoxymethyl (3-ethyl-3-oxetanylmethyl) ether, isobornyloxyethyl (3-ethyl-3-oxetanylmethyl) ether, isobornyl (3- Ethyl-3-oxetanylmethyl) ether, 2-ethylhexyl (3 Ethyl-3-oxetanylmethyl) ether, ethyldiethylene glycol (3-ethyl-3-oxetanylmethyl) ether, dicyclopentadiene (3-ethyl-3-oxetanylmethyl) ether, dicyclopentenyloxyethyl (3-ethyl-3- Oxetanylmethyl) ether, dicyclopentenyl (3-ethyl-3-oxetanylmethyl) ether, tetrahydrofurfuryl (3-ethyl-3-oxetanylmethyl) ether, tetrabromophenyl (3-ethyl-3-oxetanylmethyl) ether, 2-tetrabromophenoxyethyl (3-ethyl-3-oxetanylmethyl) ether, tribromophenyl (3-ethyl-3-oxetanylmethyl) ether, 2-tribromophenoxyethyl (3-ethyl-3-oxyl) Tanylmethyl) ether, 2-hydroxyethyl (3-ethyl-3-oxetanylmethyl) ether, 2-hydroxypropyl (3-ethyl-3-oxetanylmethyl) ether, butoxyethyl (3-ethyl-3-oxetanylmethyl) ether, Examples include pentachlorophenyl (3-ethyl-3-oxetanylmethyl) ether, pentabromophenyl (3-ethyl-3-oxetanylmethyl) ether, bornyl (3-ethyl-3-oxetanylmethyl) ether, and the like.

  Examples of polyfunctional oxetanes that can be used in the present invention include, for example, 3,7-bis (3-oxetanyl) -5-oxa-nonane, 3,3 ′-(1,3- (2-methylenyl) pro Pandiylbis (oxymethylene)) bis- (3-ethyloxetane), 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, 1,2-bis [(3-ethyl-3-oxetanyl) Methoxy) methyl] ethane, 1,3-bis [(3-ethyl-3-oxetanylmethoxy) methyl] propane, ethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, dicyclopentenyl bis (3-ethyl- 3-oxetanylmethyl) ether, triethyleneglycol bis (3-ethyl-3-oxetanylmethyl) ether, tetraethylene Glycol bis (3-ethyl-3-oxetanylmethyl) ether, tricyclodecanediyldimethylene (3-ethyl-3-oxetanylmethyl) ether, trimethylolpropane tris (3-ethyl-3-oxetanylmethyl) ether, 1, 4-bis (3-ethyl-3-oxetanylmethoxy) butane, 1,6-bis (3-ethyl-3-oxetanylmethoxy) hexane, pentaerythritol tris (3-ethyl-3-oxetanylmethyl) ether, pentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether, polyethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol hexakis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol Rupentakis (3-ethyl-3-oxetanylmethyl) ether, dipentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether, caprolactone-modified dipentaerythritol hexakis (3-ethyl-3-oxetanylmethyl) ether, caprolactone-modified Dipentaerythritol pentakis (3-ethyl-3-oxetanylmethyl) ether, ditrimethylolpropane tetrakis (3-ethyl-3-oxetanylmethyl) ether, ethylene oxide (EO) modified bisphenol A bis (3-ethyl-3-oxetanyl) Methyl) ether, propylene oxide (PO) modified bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, EO modified hydrogenated bisphenol A bis (3-ethyl-3- Polyfunctional oxetanes such as oxetanylmethyl) ether, PO-modified hydrogenated bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, and EO-modified bisphenol F (3-ethyl-3-oxetanylmethyl) ether.

The compound having such an oxetane ring is described in detail in the above-mentioned JP-A No. 2003-341217, paragraph numbers [0021] to [0084], and the compounds described therein can be suitably used in the present invention. .
In the present invention, when an oxetane compound is used, it is preferable to use at least one compound selected from an epoxy compound and a vinyl ether compound in combination.
A polymeric compound may be used individually by 1 type, and may be used in combination of 2 or more type. However, since fixing takes time when water or an aqueous solvent is contained, the polymerizable compound is preferably water-insoluble.

  The content of the polymerizable compound in the colored liquid composition is preferably 20 to 95 parts by weight, more preferably 25 to 90 parts by weight, and more preferably 50 to 85 parts by weight with respect to the total amount of the colored liquid composition. More preferably, it is a part. It is preferable for it to be within the above numerical value range since it is excellent in curability and has an appropriate viscosity.

  The content of the polymerizable compound in the undercoat liquid composition is preferably 0.5 to 95 parts by weight, more preferably 2 to 90 parts by weight, with respect to the total amount of the undercoat liquid composition. More preferably, it is 90 parts by weight. It is preferable for it to be within the above numerical value range since it is excellent in curability and has an appropriate viscosity.

<Photopolymerization initiator>
In the present invention, the colored liquid composition and the undercoat liquid composition each contain a photopolymerization initiator. The photopolymerization initiator contains a photopolymerization initiator for radical polymerization or cationic polymerization.
The photopolymerization initiator in the present invention is a compound that undergoes chemical action to generate a chemical change and generates at least one of radicals, acids, and bases. Among them, polymerization is initiated by a simple means of exposure. From the viewpoint that it can be produced, the photo radical generator or the photo acid generator is preferred.

  Specific photopolymerization initiators known to those skilled in the art can be used without limitation, and specifically, for example, Bruce M. et al. Monroe et al., Chemical Review, 93, 435 (1993). R. S. By Davidson, Journal of Photochemistry and biologic A: Chemistry, 73.81 (1993). J. P. Faussier “Photoinitiated Polymerization—Theory and Applications”: Rapra Review vol. 9, Report, Rapra Technology (1998). M. Tsunooka et al. , Prog. Polym. Sci. , 21, 1 (1996). Many are described. In addition, a large number of chemical amplification type photoresists and compounds used for photocationic polymerization are described in (Organic Electronics Materials Study Group, “Organic Materials for Imaging”, Bunshin Publishing (1993), pages 187 to 192). ing. Further, F.I. D. Saeva, Topics in Current Chemistry, 156, 59 (1990). G. G. Maslak, Topics in Current Chemistry, 168, 1 (1993). H., et al. B. Shuster et al, JACS, 112, 6329 (1990). , I. D. F. Eaton et al, JACS, 102, 3298 (1980). A group of compounds that undergo oxidative or reductive bond cleavage through interaction with the electronically excited state of the sensitizer as described in the above.

  Preferred photopolymerization initiators include (a) aromatic ketones, (b) aromatic onium salt compounds, (c) organic peroxides, (d) hexaarylbiimidazole compounds, (e) ketoxime ester compounds, f) borate compounds, (g) azinium compounds, (h) metallocene compounds, (i) active ester compounds, (j) compounds having a carbon halogen bond, and the like.

  (A) As a preferable example of aromatic ketones, “RADIATION CURING IN POLYMER SCIENCE AND TECHNOLOGY” P. FOUASSIER J.M. F. Examples include compounds having a benzophenone skeleton or a thioxanthone skeleton described in RABEK (1993), p77-117. More preferable examples of (a) aromatic ketones include α-thiobenzophenone compounds described in JP-B-47-6416, benzoin ether compounds described in JP-B-47-3981, and JP-B-47-22326. Α-substituted benzoin compounds, benzoin derivatives described in JP-B-47-23664, aroylphosphonic acid esters described in JP-A-57-30704, dialkoxybenzophenones described in JP-B-60-26483, Benzoin ethers described in JP-A-60-26403, JP-A-62-81345, JP-B-1-34242, US Pat. No. 4,318,791, and α-aminobenzophenones described in European Patent 0284561A1, P-di (dimethyla) described in JP-A-2-211452 Nobenzoyl) benzene, thio-substituted aromatic ketone described in JP-A-61-194062, acylphosphine sulfide described in JP-B-2-9597, acylphosphine described in JP-B-2-9596, JP-B-63- Examples thereof include thioxanthones described in Japanese Patent No. 61950, and coumarins described in Japanese Patent Publication No. 59-42864.

  (B) Aromatic onium salts include Group V, VI and VII elements of the Periodic Table, specifically N, P, As, Sb, Bi, O, S, Se, Te, or I fragrances Group onium salts are included. For example, iodonium salts described in European Patent No. 104143, US Pat. No. 4,837,124, Japanese Patent Laid-Open No. 2-150848, Japanese Patent Laid-Open No. 2-96514, European Patent Nos. 370693, 233567, and 297443 are disclosed. , 294442, 279210, and 422570, U.S. Pat. Nos. 3,902,144, 4,933,377, 4,760013, 4,734,344, and 2,833,827, sulfonium salts and diazonium salts (Such as benzenediazonium which may have a substituent), diazonium salt resins (formaldehyde resin of diazodiphenylamine, etc.), N-alkoxypyridinium salts, etc. (for example, US Pat. No. 4,743,528, JP 63-138345 JP-A-63-142345, JP-A-63-142346, and JP-B-46-42363, specifically 1-methoxy-4-phenylpyridinium tetrafluoroborate, etc. And compounds described in JP-B Nos. 52-147277, 52-14278, and 52-14279 are preferably used. Generates radicals and acids as active species.

  (C) “Organic peroxide” includes almost all organic compounds having one or more oxygen-oxygen bonds in the molecule. Examples thereof include 3,3 ′, 4,4′-tetra ( t-butylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (t-amylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (t-hexylperoxycarbonyl) benzophenone 3,3 ′, 4,4′-tetra (t-octylperoxycarbonyl) benzophenone, 3,3 ′, 4,4′-tetra (cumylperoxycarbonyl) benzophenone, 3,3 ′, 4,4 ′ Peroxide esters such as tetra (p-isopropylcumylperoxycarbonyl) benzophenone and di-t-butyldiperoxyisophthalate are preferred.

  (D) Examples of hexaarylbiimidazoles include lophine dimers described in JP-B Nos. 45-37377 and 44-86516, such as 2,2′-bis (o-chlorophenyl) -4,4 ′, 5. , 5′-tetraphenylbiimidazole, 2,2′-bis (o-bromophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o, p-dichlorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole, 2,2'-bis (o-chlorophenyl) -4,4', 5,5'-tetra (m-methoxyphenyl) biimidazole, 2, 2′-bis (o, o′-dichlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-nitrophenyl) -4,4 ′, 5,5 ′ -Tet Phenylbiimidazole, 2,2′-bis (o-methylphenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (o-trifluorophenyl) -4,4 ′ , 5,5′-tetraphenylbiimidazole and the like.

  (E) As ketoxime esters, 3-benzoyloxyiminobutan-2-one, 3-acetoxyiminobutan-2-one, 3-propionyloxyiminobutan-2-one, 2-acetoxyiminopentane-3-one 2-acetoxyimino-1-phenylpropan-1-one, 2-benzoyloxyimino-1-phenylpropan-1-one, 3-p-toluenesulfonyloxyiminobutan-2-one, 2-ethoxycarbonyloxy Examples include imino-1-phenylpropan-1-one.

  Examples of the (f) borate salt which is another example of the photopolymerization initiator in the present invention include US Pat. Nos. 3,567,453, 4,343,891, and European Patent 109,772. And the compounds described in the above-mentioned 109,773.

  Other examples of the photopolymerization initiator (g) Examples of azinium salt compounds include JP-A 63-138345, JP-A 63-142345, JP-A 63-142346, and JP-A 63-142346. Examples include compounds having an N—O bond described in JP-A-63-143537 and JP-B-46-42363.

Examples of (h) metallocene compounds which are other examples of photopolymerization initiators include JP-A 59-152396, JP-A 61-151197, JP-A 63-41484, and JP-A 2 No. -249, JP-A-2-4705, etc. and titanocene compounds described in JP-A-1-304453, JP-A-1-152109, etc. Can do.
Specific examples of the titanocene compound include di-cyclopentadienyl-Ti-di-chloride, di-cyclopentadienyl-Ti-bis-phenyl, and di-cyclopentadienyl-Ti-bis-2,3. 4,5,6-pentafluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-cyclopentadienyl-Ti- Bis-2,4,6-trifluorophen-1-yl, di-cyclopentadienyl-Ti-2,6-difluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,4 -Difluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophen-1-yl, di-methylcyclopentadienyl-Ti- -2,3,5,6-tetrafluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,4-difluorophen-1-yl, bis (cyclopentadienyl) -bis (2,6-difluoro-3- (pyridin-1-yl) phenyl) titanium, bis (cyclopentadienyl) bis [2,6-difluoro-3- (methylsulfonamido) phenyl] titanium, bis (cyclopenta And dienyl) bis [2,6-difluoro-3- (N-butylbialoyl-amino) phenyl] titanium.

  (I) Examples of the active ester compound include EP 0290750, 046083, 156153, 271851, and 0388343, US patents, etc. Nitrobenzyl ester compounds described in each specification such as Japanese Patent No. 3901710, US Pat. No. 4,181,531, and Japanese Patent Application Laid-Open Nos. 60-198538 and 53-133022, European Patents Nos. 0199672, 84515, 199672, 0441115, 0101122, etc., US Pat. Nos. 4,618,564, 4,371,605, and No. 4431774, etc., JP-A 64-18143, JP-A 2-245 No. 56 and JP-A-4-365048, etc., each of the iminosulfonate compounds, JP-B-62-2223, JP-B-63-14340, JP-A-59-174831, etc. Examples include compounds described in the publication.

(J) Preferred examples of the compound having a carbon halogen bond include, for example, Wakabayashi et al., Bull. Chem. Soc. Examples include compounds described in Japan, 42, 2924 (1969), compounds described in British Patent 1388492, compounds described in JP-A-53-133428, compounds described in German Patent 3333724, and the like. .
F.F. C. J. Schaefer et al. Org. Chem. 29, 1527 (1964), compounds described in JP-A-62-258241, compounds described in JP-A-5-281728, and the like. A compound as described in German Patent No. 2641100, a compound described in German Patent No. 3333450, a group of compounds described in German Patent No. 3021590, or a group of compounds described in German Patent No. 3021599, etc. Can be mentioned.

The colored liquid composition contains at least two types of photopolymerization initiators having different spectral absorption spectra, and can be arbitrarily selected from the photopolymerization initiators.
Here, “the spectral absorption spectrum is different” means that the shape of the spectral absorption spectrum of the photopolymerization initiator is different. As a result, the curability of the colored liquid composition varies depending on the wavelength of light to be exposed.

A specific procedure for determining whether or not the absorption spectra are different can be performed as follows. Photopolymerization initiator I and photopolymerization initiator II to be compared with a certain solvent are dissolved at equal concentrations, and the absorbance of the solution is measured with a commercially available spectrophotometer. Absorbances AI (λ1) and AII (λ1) at a certain wavelength λ1 are obtained from the absorption spectra of the respective solutions,
AI (λ1) / AII (λ1)> 1.1, or
AI (λ1) / AII (λ1) <0.9
If so, it can be determined that the absorption spectra are different.
here,
AI (λ1): absorbance at a wavelength λ1 of a solution of photopolymerization initiator I AII (λ1): absorbance at a wavelength λ1 of a solution of photopolymerization initiator II

  Here, the solvent of the solution is preferably acetonitrile. The concentration of the photopolymerization initiator in the solution is preferably 0.001% by weight, 0.01% by weight, 0.1% by weight, or 1% by weight. The optical path length when measuring absorbance is preferably 1 cm or 0.1 cm. The wavelengths λ1 and λ2 are preferably 365 nm and 255 nm. As a commercially available spectrophotometer, for example, a V560 spectrophotometer manufactured by JASCO Corporation can be used.

In the present invention, as a combination of photopolymerization initiators having different absorption spectra, the following photopolymerization initiator A and photopolymerization initiator B are preferable.
Photopolymerization initiator A: The photopolymerization initiator A is dissolved in an acetonitrile solution at a concentration of 0.1% by weight, and the absorbance (optical path length: 1 cm) of the solution with respect to a wavelength of 365 nm is 0.2 or less. Further, the absorbance (optical path length: 1 cm) for a wavelength of 255 nm is preferably 0.3 or more.
Photopolymerization initiator B: The photopolymerization initiator B is dissolved in an acetonitrile solution at a concentration of 0.1% by weight, and the absorbance (optical path length: 1 cm) of the solution with respect to a wavelength of 365 nm is 0.3 or more.

Specifically, a photopolymerization initiator selected from Group A and a photopolymerization initiator selected from Group B are a preferred combination of photopolymerization initiators.
Group A:
Irgacure 184 (Photopolymerization initiator manufactured by Ciba Specialty Chemicals)
Irgacure 651 (Photopolymerization initiator manufactured by Ciba Specialty Chemicals)
Irgacure 127 (photopolymerization initiator manufactured by Ciba Specialty Chemicals)
Darocur 1173 (Ciba Specialty Chemicals photopolymerization initiator)
Irgacure 754 (Ciba Specialty Chemicals photopolymerization initiator)
Group B:
Darocure TPO (Ciba Specialty Chemicals photopolymerization initiator)
Irgacure 819 (Ciba Specialty Chemicals photopolymerization initiator)
Irgacure 907 (Photopolymerization initiator manufactured by Ciba Specialty Chemicals)
Irgacure 369 (Photopolymerization initiator manufactured by Ciba Specialty Chemicals)

  The mixing ratio of the group A photopolymerization initiator and the group B photopolymerization initiator is preferably 10:90 to 90:10, more preferably 20:80 to 80:20, by weight. 30:70 to 70:30 is more preferable.

  The photopolymerization initiator is preferably 0.1 to 15.0% by weight, more preferably 1.0 to 10.0% by weight, and still more preferably, as the addition concentration of the colored liquid composition and the undercoat liquid composition. 2.0 to 8.0% by weight. When it is within the above numerical range, the viscosity after the first exposure is moderate, and the curability during the second exposure is excellent.

<Sensitizer>
To the colored liquid composition and the undercoat liquid composition in the present invention, a sensitizing dye may be added as a sensitizer for the purpose of improving the sensitivity of the photopolymerization initiator, if necessary.
Examples of preferred sensitizing dyes include those belonging to the following compounds and having an absorption wavelength in the 350 nm to 450 nm region.
Specifically, polynuclear aromatics (eg, pyrene, perylene, triphenylene), xanthenes (eg, fluorescein, eosin, erythrosine, rhodamine B, rose bengal), cyanines (eg, thiacarbocyanine, oxacarbocyanine) , Merocyanines (eg, merocyanine, carbomerocyanine), thiazines (eg, thionine, methylene blue, toluidine blue), acridines (eg, acridine orange, chloroflavin, acriflavine), anthraquinones (eg, anthraquinone), squalium (For example, squalium) and coumarins (for example, 7-diethylamino-4-methylcoumarin).

<Co-sensitizer>
Furthermore, in the colored liquid composition and the undercoat liquid composition in the present invention, a known compound having an action such as further improving sensitivity or suppressing polymerization inhibition by oxygen may be added as a co-sensitizer. Like the sensitizing dye, the co-sensitizer is preferably contained in the colored liquid composition and the undercoat liquid composition containing the photopolymerization initiator from the viewpoint of liquid stability.
Examples of such cosensitizers include amines such as M.I. R. Sander et al., “Journal of Polymer Society”, Vol. 10, 3173 (1972), Japanese Patent Publication No. 44-20189, Japanese Patent Publication No. 51-82102, Japanese Patent Publication No. 52-134692, Japanese Patent Publication No. 59-138205. No. 60-84305, JP-A 62-18537, JP-A 64-33104, Research Disclosure 33825, and the like. Specific examples include triethanolamine. P-dimethylaminobenzoic acid ethyl ester, p-formyldimethylaniline, p-methylthiodimethylaniline and the like.

  Other examples include thiols and sulfides, for example, thiol compounds described in JP-A-53-702, JP-B-55-500806, JP-A-5-142772, and JP-A-56-75643. Examples thereof include disulfide compounds, and specific examples include 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, 2-mercapto-4 (3H) -quinazoline, β-mercaptonaphthalene and the like.

  Other examples include amino acid compounds (eg, N-phenylglycine), organometallic compounds described in Japanese Patent Publication No. 48-42965 (eg, tributyltin acetate), and hydrogen described in Japanese Patent Publication No. 55-34414. Donors, sulfur compounds described in JP-A-6-308727 (eg, trithiane), phosphorus compounds described in JP-A-6-250387 (diethylphosphite, etc.), Si-- described in JP-A-8-65779 H, Ge-H compound, etc. are mentioned.

<Colorant>
In the present invention, the colored liquid composition contains at least a colorant. On the other hand, the undercoat liquid composition contains substantially no colorant.
There is no restriction | limiting in particular in the coloring agent which can be used in this invention, According to a use, well-known various pigments and dyes can be selected suitably and can be used. Among them, the colorant contained in the colored liquid composition is preferably a pigment from the viewpoint of excellent light resistance.

The pigment preferably used in the present invention will be described.
The pigment is not particularly limited, and all commercially available organic pigments and inorganic pigments, and those obtained by dyeing resin particles with a dye can be used. Furthermore, commercially available pigment dispersions and surface-treated pigments, for example, pigments dispersed in an insoluble resin or the like as a dispersion medium, or those obtained by grafting a resin on the pigment surface, etc., impair the effects of the present invention. It can be used as long as it is not.
Examples of these pigments include, for example, “Pigment Dictionary” (2000), edited by Seijiro Ito. Herbst, K.M. Hunger “Industrial Organic Pigments”, JP 2002-12607 A, JP 2002-188025 A, JP 2003-26978 A, and JP 2003-342503 A3.

  Specific examples of organic pigments and inorganic pigments that can be used in the present invention include C.I. I. Pigment Yellow 1 (Fast Yellow G etc.), C.I. I. A monoazo pigment such as C.I. Pigment Yellow 74; I. Pigment Yellow 12 (disaji yellow AAA, etc.), C.I. I. Disazo pigments such as C.I. Pigment Yellow 17; I. Non-benzidine type azo pigments such as CI Pigment Yellow 180; I. Azo lake pigments such as C.I. Pigment Yellow 100 (eg Tartrazine Yellow Lake); I. Condensed azo pigments such as CI Pigment Yellow 95 (Condensed Azo Yellow GR, etc.); I. Acidic dye lake pigments such as C.I. Pigment Yellow 115 (such as quinoline yellow lake); I. Basic dye lake pigments such as CI Pigment Yellow 18 (Thioflavin Lake, etc.), anthraquinone pigments such as Flavantron Yellow (Y-24), isoindolinone pigments such as Isoindolinone Yellow 3RLT (Y-110), and quinophthalone yellow Quinophthalone pigments such as (Y-138), isoindoline pigments such as isoindoline yellow (Y-139), C.I. I. Nitroso pigments such as C.I. Pigment Yellow 153 (nickel nitroso yellow, etc.); I. And metal complex salt azomethine pigments such as CI Pigment Yellow 117 (copper azomethine yellow, etc.).

  C. As a thing which exhibits red or magenta color, C.I. I. Monoazo pigments such as CI Pigment Red 3 (Toluidine Red, etc.); I. Disazo pigments such as C.I. Pigment Red 38 (Pyrazolone Red B, etc.); I. Pigment Red 53: 1 (Lake Red C, etc.) and C.I. I. Azo lake pigments such as C.I. Pigment Red 57: 1 (Brilliant Carmine 6B); I. Condensed azo pigments such as C.I. Pigment Red 144 (condensed azo red BR, etc.); I. Acidic dye lake pigments such as C.I. Pigment Red 174 (Phloxine B Lake, etc.); I. Basic dye lake pigments such as C.I. Pigment Red 81 (Rhodamine 6G 'lake, etc.); I. Anthraquinone pigments such as C.I. Pigment Red 177 (eg, dianthraquinonyl red); I. Thioindigo pigments such as C.I. Pigment Red 88 (Thioindigo Bordeaux, etc.); I. Perinone pigments such as C.I. Pigment Red 194 (perinone red, etc.); I. Perylene pigments such as C.I. Pigment Red 149 (perylene scarlet, etc.); I. Pigment violet 19 (unsubstituted quinacridone), C.I. I. Quinacridone pigments such as CI Pigment Red 122 (quinacridone magenta, etc.); I. Isoindolinone pigments such as CI Pigment Red 180 (isoindolinone red 2BLT, etc.); I. And alizarin lake pigments such as CI Pigment Red 83 (Mada Lake, etc.).

  As a pigment exhibiting blue or cyan, C.I. I. Disazo pigments such as C.I. Pigment Blue 25 (Dianisidine Blue, etc.); I. Phthalocyanine pigments such as C.I. Pigment Blue 15 (phthalocyanine blue, etc.); I. Acidic dye lake pigments such as C.I. Pigment Blue 24 (Peacock Blue Lake, etc.); I. Basic dye lake pigments such as C.I. Pigment Blue 1 (Viclotia Pure Blue BO Lake, etc.); I. Anthraquinone pigments such as C.I. Pigment Blue 60 (Indantron Blue, etc.); I. And alkali blue pigments such as CI Pigment Blue 18 (Alkali Blue V-5: 1).

  As a pigment exhibiting green, C.I. I. Pigment green 7 (phthalocyanine green), C.I. I. Phthalocyanine pigments such as C.I. Pigment Green 36 (phthalocyanine green); I. And azo metal complex pigments such as CI Pigment Green 8 (Nitroso Green).

  As a pigment exhibiting an orange color, C.I. I. An isoindoline pigment such as C.I. Pigment Orange 66 (isoindoline orange); I. And anthraquinone pigments such as CI Pigment Orange 51 (dichloropyrantron orange).

  Examples of the black pigment include carbon black, titanium black, and aniline black.

Specific examples of the white pigment include basic lead carbonate (2PbCO ₃ Pb (OH) ₂ , so-called silver white), zinc oxide (ZnO, so-called zinc white), titanium oxide (TiO ₂ , so-called titanium white), Strontium titanate (SrTiO ₃ , so-called titanium strontium white) or the like can be used.
Here, titanium oxide has a smaller specific gravity than other white pigments, a large refractive index, and is chemically and physically stable, and therefore has a high hiding power and coloring power as a pigment. Excellent durability against other environments. Therefore, it is preferable to use titanium oxide as the white pigment. Of course, other white pigments (may be other than the listed white pigments) may be used as necessary.

  For dispersing the colorant, for example, a dispersing device such as a ball mill, a sand mill, an attritor, a roll mill, a jet mill, a homogenizer, a paint shaker, a kneader, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a pearl mill, or a wet jet mill is used. be able to.

When dispersing the colorant, a dispersant such as a surfactant can be added.
Moreover, when adding a coloring agent, it is also possible to use the synergist according to various coloring agents as a dispersing aid as needed. The dispersing aid is preferably added in an amount of 1 to 50 parts by mass with respect to 100 parts by mass of the colorant.

  As a dispersion medium for various components such as a colorant in the colored liquid composition, a solvent may be added, or the polymerizable compound which is a low molecular weight component without a solvent may be used as a dispersion medium. The colored liquid composition is preferably an actinic radiation curable liquid, and is preferably solvent-free in order to cure the colored liquid composition after it is applied to the recording medium. This is because if the solvent remains in the image formed from the cured colored liquid composition, the solvent resistance is deteriorated or a problem of VOC (Volatile Organic Compound) of the remaining solvent occurs. From such a viewpoint, it is preferable to use a polymerizable compound as the dispersion medium, and in particular, to select a polymerizable compound having the lowest viscosity from the viewpoint of improving dispersibility and handling properties of the ink composition.

  The average particle diameter of the colorant used here is preferably from 0.01 to 0.4 μm, more preferably from 0.02 to 0.2 μm, because the finer the particle, the better the color developability. The selection of the colorant, dispersant, and dispersion medium, dispersion conditions, and filtration conditions are set so that the maximum particle size is 3 μm or less, preferably 1 μm or less. By controlling the particle size, clogging of the head nozzle can be suppressed, and the storage stability of the colored liquid composition, the transparency of the colored liquid composition, and the curing sensitivity can be maintained. In the present invention, by using the dispersant having excellent dispersibility and stability, a uniform and stable dispersion can be obtained even when a fine particle colorant is used.

  The particle size of the colorant in the colored liquid composition can be measured by a known measurement method. Specifically, it can be measured by a centrifugal sedimentation light transmission method, an X-ray transmission method, a laser diffraction / scattering method, and a dynamic light scattering method. In the present invention, a value obtained by measurement using a laser diffraction / scattering method is employed.

  The colorant is preferably added in an amount of 50% by weight or less, more preferably 1% by weight or more and 30% by weight or less, and particularly preferably 2% by weight or more and 20% by weight or less. preferable.

<Surfactant>
The surfactant contained in the colored liquid composition and the undercoat liquid composition can be selected from the following. Examples thereof include those described in JP-A Nos. 62-173463 and 62-183457. Specifically, for example, anionic surfactants such as dialkyl sulfosuccinates, alkyl naphthalene sulfonates, fatty acid salts, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols, polyoxyethylene -Nonionic surfactants such as polyoxypropylene block copolymers, and cationic surfactants such as alkylamine salts and quaternary ammonium salts. An organic fluoro compound may be used instead of the known surfactant. The organic fluoro compound is preferably hydrophobic. Examples of the organic fluoro compounds include fluorine surfactants, oily fluorine compounds (eg, fluorine oil) and solid fluorine compound resins (eg, tetrafluoroethylene resin). Nos. (Columns 8 to 17) and JP-A No. 62-135826.

In particular, the surfactant used in the present invention is not limited to the above-described surfactant, and may be any additive capable of efficiently reducing the surface tension with respect to the added concentration.
In the present invention, silicon-based surfactants such as polyether-modified polydimethylsiloxane and polyether-modified hydroxy group-containing polydimethylsiloxane can be used as the surfactant. Specific examples include BYK-306, BYK-307, BYK-308, BYK-310, BYK-330, BYK-333, BYK-341, and BYK-344 (manufactured by BYK-Chemie (BIC Chemie)). .
In the present invention, the content of the surfactant in the liquid composition is appropriately selected depending on the purpose of use. When the undercoat liquid composition is used, the amount of the surfactant added is preferably 0.5 to 1.5% by weight based on the total weight of the undercoat liquid composition. Within the above numerical range, repelling and bleeding can be suppressed even when a non-absorbable recording medium is used.
Moreover, it is preferable that the addition amount of surfactant is 0.0001 to 0.2 weight% with respect to the weight of the whole coloring liquid composition. Within the range of the above numerical values, the colorant can be well dispersed, and interference between droplet ejections does not occur after ejection by the ink jet method.

<Other additives>
In the colored liquid composition and the undercoat liquid composition in the present invention, various additives can be used in combination according to the purpose in addition to the polymerizable compound and the photopolymerization initiator. For example, an ultraviolet absorbent can be used from the viewpoint of improving the weather resistance of the obtained image. In addition, an antioxidant can be added to improve the stability of the colored liquid composition and the undercoat liquid composition.

  Furthermore, various organic and metal complex anti-fading agents, conductive salts such as potassium thiocyanate, lithium nitrate, ammonium thiocyanate, dimethylamine hydrochloride for the purpose of controlling injection properties, fine pattern moldings and groups In order to improve the adhesion to the material, a trace amount of organic solvent can be added.

  Moreover, various polymer compounds can be added to adjust film physical properties. High molecular compounds include acrylic polymers, polyvinyl butyral resins, polyurethane resins, polyamide resins, polyester resins, epoxy resins, phenol resins, polycarbonate resins, polyvinyl butyral resins, polyvinyl formal resins, shellacs, vinyl resins, acrylic resins. Rubber resins, waxes and other natural resins can be used. Two or more of these may be used in combination.

  In addition to this, if necessary, for example, leveling additives, matting agents, waxes for adjusting film physical properties, tackifiers that do not inhibit polymerization in order to improve adhesion to polyolefins, PET, etc. Can be contained.

<Physical properties of colored liquid composition>
The colored liquid composition may be a liquid at room temperature, but from the viewpoint of appropriate droplet ejection by inkjet, the viscosity at 25 ° C. is preferably 100 mPa · s or less, or the viscosity at 60 ° C. is preferably 30 mPa · s or less. The viscosity at 60 ° C. is more preferably 60 mPa · s or less or the viscosity at 60 ° C. is more preferably 20 mPa · s or less, and the viscosity at 25 ° C. is particularly preferably 40 mPa · s or less or the viscosity at 60 ° C. is 15 mPa · s or less. .

  Similarly, the surface tension at 25 ° C. is preferably 20 mN / m or more and 40 mN / m or less, more preferably 22 mN / m or more and 35 mN / m or less, more preferably 24 mN / m from the viewpoint of appropriate droplet ejection by inkjet. m to 32 mN / m is more preferable.

<Physical properties of undercoat liquid composition>
The undercoat liquid composition may be liquid at room temperature, but from the viewpoint of uniformly coating on the recording medium, the viscosity at 25 ° C. is 1,000 mPa · s or less, or the viscosity at 60 ° C. is 300 mPa · s or less. It is preferable that the viscosity at 25 ° C. is 600 mPa · s or less or more preferable that the viscosity at 60 ° C. is 200 mPa · s or less. The viscosity at 25 ° C. is 400 mPa · s or less or the viscosity at 60 ° C. is 150 mPa · s or less. It is particularly preferred that

  Similarly, from the viewpoint of uniformly coating on the recording medium, the surface tension at 25 ° C. of the undercoat liquid composition is preferably 18 mN / m or more and 38 mN / m or less, more preferably 20 mN / m or more and 33 mN / m or less, and 22 mN. / M or more and 30 mN / m or less is more preferable.

The “viscosity” here is a viscosity determined using a RE80 viscometer manufactured by Toki Sangyo Co., Ltd. The RE80 type viscometer is a conical rotor / plate type viscometer corresponding to the E type. No. 1 rotor, 10r. p. m. The number of rotations was measured. However, for those having a viscosity higher than 60 mPa · s, the rotational speed is 5 r. p. m. 2.5r. p. m. 1r. p. m. 0.5r. p. m. The measurement was performed while changing to
The surface tension is a value measured at a liquid temperature of 25 ° C. by the Wilhelmy method using a commonly used surface tension meter (for example, surface tension meter CBVP-Z manufactured by Kyowa Interface Science Co., Ltd.). .

  From the viewpoint of preventing bleeding of the formed image for a long time until the colored liquid composition applied on the non-recording medium starts to be cured, the surface tension γA of the colored liquid composition and the surface tension of the undercoat liquid composition The relationship with γB preferably satisfies γA> γB, more preferably satisfies γA−γB> 1 (mN / m), and particularly preferably satisfies γA−γB> 2 (mN / m).

(Recording medium)
In the inkjet recording method of the present invention, any of a permeable recording medium, a non-permeable recording medium, and a slowly permeable recording medium can be used as the recording medium. Among these, a non-permeable or slowly permeable recording medium is preferable from the viewpoint of more remarkable effects of the present invention. Here, the permeable recording medium is, for example, a recording medium having a time of 100 ms or less until the total liquid amount permeates when a 10 pL (picoliter) droplet is dropped on the recording medium. Say. Further, the non-permeable recording medium refers to a recording medium in which liquid droplets do not substantially permeate. “Substantially does not penetrate” means, for example, that the penetration rate of a droplet after 1 minute is 5% or less. Further, the slow-penetrating recording medium refers to a recording medium in which when a 10 pL droplet is dropped on the recording medium, the time until the entire liquid amount permeates is 100 ms or more.

Examples of the permeable recording medium include plain paper, porous paper, and other recording media that can absorb liquid.
Examples of the non-permeable or slowly permeable recording medium include art paper, synthetic resin, rubber, resin-coated paper, glass, metal, earthenware, and wood. In the present invention, a recording medium obtained by combining a plurality of these materials can be used for the purpose of adding functions.

  As the synthetic resin, any synthetic resin can be used. For example, polyesters such as polyethylene terephthalate and polybutadiene terephthalate, polyolefins such as polyvinyl chloride, polystyrene, polyethylene, polyurethane, and polypropylene, acrylic resins, polycarbonates, and acrylonitrile-butadiene. -Styrene copolymer etc., Diacetate, Triacetate, Polyimide, Cellophane, Celluloid etc. are mentioned. The thickness and shape of the recording medium when using a synthetic resin are not particularly limited, and may be any of a film shape, a card shape, and a block shape, and may be transparent or opaque. Good.

  The synthetic resin is preferably used in the form of a film used for so-called soft packaging, and various non-absorbable plastics and films thereof can be used. Examples of the plastic film include a PET film, an OPS film, an OPP film, a PNy film, a PVC film, a PE film, a TAC film, and a PP film. Other plastics that can be used include polycarbonate, acrylic resin, ABS, polyacetal, PVA, and rubbers.

  Examples of the resin-coated paper include a transparent polyester film, an opaque polyester film, an opaque polyolefin resin film, and a paper support in which both surfaces of paper are laminated with a polyolefin resin. Particularly preferred is a paper support in which both sides of the paper are laminated with a polyolefin resin.

  There is no restriction | limiting in particular as said metal, For example, aluminum, iron, gold | metal | money, silver, copper, nickel, titanium, chromium, molybdenum, silicon, lead, zinc, stainless steel, etc., and these composite materials are suitable.

  Furthermore, a read-only optical disk such as a CD-ROM or DVD-ROM, a write-once optical disk such as a CD-R or DVD-R, or a rewritable optical disk can be used, and ink jet recording is performed on the label surface side. be able to.

(Recording process)
In the inkjet recording method of the present invention, the recording method includes a step of applying the undercoat liquid composition onto a recording medium, a step of applying the colored liquid composition onto a recording medium, and the colored liquid composition. And / or at least a first exposure step of semi-curing the undercoat liquid composition and a second exposure step of completely curing the colored liquid composition and the undercoat liquid composition.
In the present invention, “on the recording medium” may be an upper part of the recording medium, and does not necessarily need to be in contact with each other, and other composition layers may be interposed between the recording medium. Good.

Here, the colored liquid composition is preferably used for forming an image, and the undercoat liquid composition is preferably used as an undercoat liquid. That is, the step of applying the undercoat liquid composition onto the recording medium is preferably performed prior to the step of applying the colored liquid composition onto the recording medium.
The inkjet recording method of the present invention includes a first exposure step of semi-curing the colored liquid composition and / or the undercoat liquid composition, that is, at least one of the colored liquid composition and the undercoat liquid composition. It is preferable to include a first exposure step of semi-curing, and more preferable to include at least a first exposure step of semi-curing the undercoat liquid composition.
In the above step, first, a step of applying an undercoat liquid composition onto a recording medium is performed, followed by a first exposure step of semi-curing the undercoat liquid composition, the semi-cured undercoat liquid composition It is preferable to carry out the steps in which the colored liquid composition is ejected onto the object to form an image, the second exposure step to completely cure the image, and the order described above.
Moreover, it is preferable that the colored liquid composition in the present invention uses a plurality of colored liquid compositions as a multicolor ink set. When a multicolor ink set is used as described above, it is more preferable to perform the step of semi-curing the colored liquid composition for each color liquid composition after the colored liquid composition is applied onto the recording medium. . This exposure step corresponds to the first exposure step in the sense of semi-curing.

Accordingly, the most preferable steps of the ink jet recording method of the present invention are as follows.
In the first step, the undercoat liquid composition liquid is applied onto the recording medium. Subsequently, in the second step, the undercoat liquid composition liquid is semi-cured. In the third step, the undercoat liquid composition applied on the recording medium is semi-cured (first exposure). In the fourth step, a yellow image is formed with the yellow colored liquid composition on the film of the undercoat liquid composition semi-cured on the recording medium. In the fifth step, the yellow colored liquid composition is semi-cured (first exposure). In the sixth step, a cyan image is formed with the cyan colored liquid composition on the film of the undercoat liquid composition semi-cured on the recording medium and / or the film of the semi-cured yellow liquid composition. In the seventh step, the cyan colored liquid composition is semi-cured (first exposure). In the eighth step, a magenta image is formed with the magenta colored liquid composition on the film of the undercoat liquid composition semi-cured on the recording medium and / or the semi-cured yellow and cyan liquid composition. In the ninth step, the magenta colored liquid composition is semi-cured (first exposure). In the tenth step, a black image is formed with the black colored liquid composition on the film of the undercoat liquid composition semi-cured on the recording medium and / or the semi-cured yellow, cyan and magenta liquid composition. In the eleventh step, the full-color image is completely cured (second exposure).
In addition, after forming an image with a colored liquid, a method known to those skilled in the art may be appropriately performed, such as discharging or applying an undercoat liquid as an overcoat layer.

<The process of providing an undercoat liquid composition on a recording medium>
In the step of applying the undercoat liquid composition on the recording medium, the undercoat liquid composition is applied to the same area as the image formed by ejecting ink droplets on the recording medium or an area wider than the image. It is preferable to do.
Further, the application amount (weight ratio per unit area) of the undercoat liquid composition ranges from 0.05 to 5 when the maximum application amount (per color) of the colored liquid composition per unit area is 1. It is preferable that it is in the range, 0.07 to 4 is more preferable, and 0.1 to 3 is particularly preferable.

In the ink jet recording method of the present invention, a coating device, an ink jet nozzle, or the like can be used as means for applying the undercoat liquid composition on the recording medium.
The coating apparatus is not particularly limited and can be appropriately selected from known coating apparatuses according to the purpose, for example, an air doctor coater, a blade coater, a lot coater, a knife coater, a squeeze coater, and an impregnation coater. , Reverse roll coater, transfer roll coater, gravure coater, kiss roll coater, cast coater, spray coater, curtain coater, and extrusion coater. For details, see Yuji Harasaki's “Coating Engineering”.
Among these, from the viewpoint of apparatus cost, the application of the undercoat liquid composition onto the recording medium is preferably performed by application using a relatively inexpensive bar coater or spin coater, or by the ink jet method.

<First exposure for semi-curing undercoat liquid composition>
In the present invention, “semi-cured” means partially cured (partial cured; partial curing), and is an undercoat liquid composition (hereinafter also simply referred to as “undercoat liquid”) and / or (hereinafter, simply “ Also referred to as “colored liquid”), which is partially cured but not completely cured. When the undercoat liquid applied on the recording medium (base material) or the colored liquid discharged onto the undercoat liquid is semi-cured, the degree of curing may be uneven. For example, the undercoat liquid and / or the ink liquid is preferably cured in the depth direction.

Examples of the method of semi-curing the undercoat liquid and / or the coloring liquid include a method in which active energy rays are given to the undercoat liquid and / or the coloring liquid, that is, a curing reaction is caused by exposure.
The method of giving an active energy ray to cause a semi-curing reaction is a method in which the polymerization reaction of the polymerizable compound on the surface of the undercoat liquid and / or the coloring liquid applied to the recording medium is insufficient.

  When polymerizing a radically polymerizable undercoat liquid or colored liquid in an atmosphere containing a large amount of oxygen such as in the air or in air partially substituted with an inert gas, it is necessary to suppress the radical polymerization of oxygen. There is a tendency that radical polymerization is inhibited on the surface of the undercoat liquid layer or colored liquid droplets (hereinafter also referred to as “colored liquid droplets”) applied on the recording medium. As a result, the semi-curing becomes non-uniform, the curing progresses more inside the undercoat liquid layer or the colored liquid droplets, and the surface curing tends to be delayed. Here, the undercoat liquid layer is a layer of the undercoat liquid applied on the substrate.

  Even when the cationic polymerizable undercoat liquid or colored liquid is polymerized in an atmosphere having moisture, the undercoat liquid layer or colored liquid droplets applied on the recording medium have an effect of inhibiting cationic polymerization of moisture. Curing progresses more inside and tends to delay the curing of the surface.

In the present invention, when the radical photopolymerizable undercoating liquid or coloring liquid is used in the presence of radical polymerization-inhibiting oxygen and partially photocured, the undercoating liquid and / or the coloring liquid is cured more than the outside. More progress inside.
In particular, the surface of the undercoat liquid is more likely to inhibit the polymerization reaction due to the influence of oxygen in the air as compared to the inside. Therefore, the undercoat liquid can be semi-cured by controlling the application conditions of the active energy ray.

The application of active energy rays such as actinic light and heating promotes the generation of active species due to the decomposition of the polymerization initiator, and increases the active species and the temperature rise, thereby increasing the polymerizable or crosslinkable material caused by the active species. Curing reaction by polymerization or crosslinking is accelerated.
Moreover, thickening (viscosity increase) can also be suitably performed by irradiation with actinic light.

  When a colored liquid is ejected onto the semi-cured undercoat liquid, or a different colored liquid (especially a colored liquid having a different hue) is ejected onto the semi-cured colored liquid, it is obtained. Which has a positive technical effect on the quality of the printed material produced. Moreover, the action mechanism can be confirmed by observing the cross section of the printed matter.

A portion (high concentration portion) ejected at a high density when about 12 pL of colored liquid is deposited on a semi-cured undercoat liquid having a thickness of about 5 μm provided on the substrate. This will be described as an example.
FIG. 1 is a schematic cross-sectional view showing one embodiment of a printed matter obtained by depositing a colored liquid onto a semi-cured undercoat liquid layer. During the production of the printed matter of FIG. 1, the undercoat liquid is semi-cured, and the substrate 16 side is more cured than the surface layer. FIG. 1 shows an undercoat layer 14 in which a coloring liquid is applied to a semi-cured undercoat liquid layer.
In this case, the following three features are observed in the cross section of the obtained image 10.
(1) A part of the colored liquid cured product 12 appears on the surface.
(2) A part of the colored liquid cured product 12 is embedded in the undercoat layer 14, and
(3) An undercoat layer 14 exists between the lower side of the colored liquid cured product 12 and the substrate 16.
That is, the printed matter obtained by applying the coloring liquid onto the semi-cured undercoat liquid layer has a cross section as schematically shown in FIG. When the above conditions (1), (2), and (3) are satisfied, it can be said that the colored liquid is applied to the semi-cured undercoat liquid. In this case, the liquid droplets of the colored liquid ejected with high density are connected to each other to form a colored film, which gives a uniform and high color density. The undercoat layer means a layer obtained by curing the undercoat liquid layer.

2 and 3 are schematic cross-sectional views showing one embodiment of a printed matter obtained by depositing a colored liquid on an uncured undercoat liquid layer. 2 and 3 show the undercoat layer 18 in which a colored liquid is applied to the uncured undercoat liquid layer.
When the colored liquid is ejected onto the uncured undercoat liquid layer, all of the colored liquid enters the undercoat liquid layer and / or the undercoat liquid does not exist below the colored liquid. Specifically, in FIG. 2, in the cross section of the image 10 to be obtained, the colored liquid cured product 12 is completely immersed in the undercoat layer 18, and a part of the colored liquid cured product 12 does not appear on the surface. . Further, as shown in FIG. 3, the undercoat layer 18 does not exist below the colored liquid cured product 12 in the cross section of the obtained image 10.
In this case, even if the coloring liquid is applied at a high density, the droplets are independent of each other, which causes a decrease in color density.

FIG. 4 is a schematic cross-sectional view showing one embodiment of a printed matter obtained by depositing a colored liquid onto a completely cured undercoat liquid layer. FIG. 4 shows the undercoat layer 20 in which a colored liquid is applied to the fully cured undercoat liquid layer.
When the colored liquid is ejected onto the completely cured undercoat liquid layer, the colored liquid does not enter the undercoat liquid layer. Specifically, as shown in FIG. 4, the colored liquid cured product 12 does not sink into the undercoat layer 20.
Such a state causes the occurrence of droplet ejection interference, a uniform colored liquid film layer cannot be formed, and the color reproducibility is lowered.

From the viewpoint of forming a uniform colored liquid liquid layer (colored film) and suppressing the occurrence of droplet ejection interference without the liquid droplets becoming independent when the colored liquid droplets are applied at high density, It is preferable that the transfer amount of the undercoat liquid per unit area is sufficiently smaller than the maximum droplet amount of the coloring liquid applied per unit area. That is, if the transfer amount (weight) per unit area of the undercoat liquid layer is M (undercoat liquid) and the maximum weight of the colored liquid applied per unit area is m (colored liquid), M (undercoat liquid), m The (coloring liquid) preferably satisfies the following relationship.
[M (colored liquid) / 30] ≦ [M (undercoat liquid)] ≦ [m (colored liquid)]
It is more preferable that [m (colored liquid) / 20] ≦ [M (undercoat liquid)] ≦ [m (colored liquid) / 3], and [m (colored liquid) / 10] ≦ M (undercoat liquid). ) ≦ [m (colored liquid) / 5]. Here, the maximum weight of the coloring liquid applied per unit area is the maximum weight per color.
It is preferable that [m (colored liquid) / 30] ≦ [M (undercoat liquid)] because the occurrence of droplet ejection interference can be suppressed and the dot size reproducibility is excellent. Further, it is preferable that M (undercoat liquid) ≦ m (colored liquid) because a uniform colored liquid layer can be formed and an image having a high density can be obtained.

Note that the transfer amount of the undercoat liquid layer per unit area was determined by the transfer test described below. After the completion of the semi-curing process (for example, after irradiation of active energy rays) and before droplets of colored liquid are ejected, a penetrating medium such as plain paper is pressed against the semi-cured undercoat liquid layer, It is defined by measuring the amount of the undercoat liquid transferred to the permeation medium.
For example, if the maximum discharge amount of the coloring liquid is 12 × 10 liters per pixel (dot) at a droplet ejection density of 600 × 600 dpi, the maximum weight m (coloring liquid) of the coloring liquid applied per unit area is 0.74 mg / cm ² (here, the density of the colored liquid is assumed to be about 1.1 g / cm ³ ). Therefore, amount of undercoat liquid layer transferred is preferably a unit area is per 0.025 mg / cm ² or more 0.74 mg / cm ² or less, more preferably 0.037 mg / cm ² or more 0.25 mg / cm ² or less More preferably, it is 0.074 mg / cm ² or more and 0.148 mg / cm ² or less.

When forming a secondary color with the coloring liquid A and the coloring liquid B, it is preferable to apply the coloring liquid B on the semi-cured coloring liquid A.
FIG. 5 is a schematic cross-sectional view showing an embodiment of a printed material obtained by ejecting the colored liquid B onto the semi-cured colored liquid A. FIG. FIG. 5 shows a colored liquid A cured product 24 and a colored liquid B cured product 22 obtained by applying the colored liquid B to the semi-cured colored liquid A.
When the colored liquid B is ejected onto the semi-cured colored liquid A, a part of the colored liquid B enters the colored liquid A, and the colored liquid A exists below the colored liquid B. . That is, the printed matter obtained by applying the coloring liquid B onto the semi-cured coloring liquid A has a part of the coloring liquid B cured product 22 on the surface as shown in FIG. Part of the colored liquid B cured product 22 is embedded in the colored liquid A cured product 24. Further, a colored liquid A cured product is present below the colored liquid B cured product 22. Colored liquid A cured film (colored film A, colored liquid A cured product 24 in FIG. 5) and colored liquid B cured film (colored film B, colored liquid B cured product 22 in FIG. 5) are laminated. Good color reproduction is possible.

6 and 7 are schematic cross-sectional views showing one embodiment of a printed matter obtained by ejecting the colored liquid B onto the uncured colored liquid A. FIG. FIG. 6 shows a colored liquid A cured product 26 and a colored liquid B cured product 22 obtained by applying the colored liquid B to the uncured colored liquid A.
When the colored liquid B is ejected onto the uncured colored liquid A, all of the colored liquid B sinks into the colored liquid A and / or the colored liquid A is not present below the colored liquid B. Become. That is, when the cross-sectional view of the obtained image is observed, as shown in FIG. 6, the entire colored liquid B cured product 22 is embedded in the colored liquid A cured product 26 and / or as shown in FIG. The colored liquid A cured product 26 does not exist in the lower layer of the colored liquid B cured product 22. In this case, even if the droplets of the colored liquid B are applied at a high density, the droplets are independent from each other, which causes a decrease in the saturation of the secondary color.

  FIG. 8 is a schematic cross-sectional view showing an embodiment of a printed material obtained by ejecting the colored liquid B onto the fully cured colored liquid A. FIG. FIG. 8 shows a colored liquid A cured product 28 and a colored liquid B cured product 22 obtained by applying the colored liquid B to the fully cured colored liquid A. When the colored liquid B is ejected onto the completely cured colored liquid A, the colored liquid B will not enter the colored liquid A. As shown in FIG. 8, the colored liquid B cured product 22 does not sink into the colored liquid A cured product 28 in the cross-sectional view of the obtained image. Such a state causes the occurrence of droplet ejection interference, a uniform colored liquid film layer cannot be formed, and the color reproducibility is lowered.

From the viewpoint of forming a uniform colored liquid B liquid layer and preventing the occurrence of droplet ejection interference, the unit area is not provided when the colored liquid B liquid droplets are applied at high density. The transfer amount of the colored liquid A per hit is preferably sufficiently smaller than the maximum droplet amount of the colored liquid B applied per unit area. That is, when the transfer amount (weight) per unit area of the colored liquid A layer is M (colored liquid A) and the maximum weight of the colored liquid B discharged per unit area is m (colored liquid B), M (colored) Liquid A) and m (colored liquid B) preferably satisfy the following relationship.
[M (colored liquid B) / 30] ≦ [M (colored liquid A)] ≦ [m (colored liquid B)]
Further, it is more preferable that [m (colored liquid B) / 20] ≦ [M (colored liquid A)] ≦ [m (colored liquid B) / 3], and [m (colored liquid B) / 10] ≦. It is more preferable that [M (colored liquid A)] ≦ [m (colored liquid B) / 5].
It is preferable that [m (colored liquid B) / 30] ≦ [M (colored liquid A)] because the occurrence of droplet ejection interference can be suppressed and the dot size reproducibility is excellent. Further, [M (colored liquid A)] ≦ [m (colored liquid B)] is preferable because a uniform colored liquid layer can be formed and an image having a high density can be obtained.

The transfer amount (weight) of the colored liquid A per unit area is determined by the transfer test described below. After completion of the semi-curing process (for example, after irradiation with active energy rays) and before droplets of the colored liquid B are ejected, a penetrating medium such as plain paper is pressed against the semi-cured colored liquid A layer. The weight of the colored liquid A transferred to the permeation medium is defined by weight measurement.
For example, when the maximum discharge amount of the coloring liquid B is 12 picoliters per pixel at a droplet ejection density of 600 × 600 dpi, the maximum weight m (coloring liquid) of the coloring liquid B discharged per unit area is 0.74 mg / cm ² (here, the density of the colored liquid B is assumed to be about 1.1 g / cm ³ ). Thus, pigmented transfer amount of liquid A layer is preferably a unit area is per 0.025 mg / cm ² or more 0.74 mg / cm ² or less, more preferably 0.037 mg / cm ² or more 0.25 mg / cm ² Or less, more preferably 0.074 mg / cm ² or more and 0.148 mg / cm ² or less.

  In the case of a curing reaction based on an ethylenically unsaturated compound or a cyclic ether, the unpolymerization rate can be quantitatively measured by the reaction rate of an ethylenically unsaturated group or a cyclic ether group (described later).

  In the case where the semi-cured state of the undercoat liquid and / or the colored liquid is realized by a polymerization reaction of a polymerizable compound that starts polymerization by irradiation with active energy rays or heating, from the viewpoint of improving the scratching property of the printed matter, the unpolymerized rate (A (after polymerization) / A (before polymerization)) is preferably 0.2 or more and 0.9 or less, more preferably 0.3 or more and 0.9 or less, and 0.5 or more and 0.0 or less. Particularly preferably, it is 9 or less.

Here, A (after polymerization) is the absorbance of the infrared absorption peak due to the polymerizable group after the polymerization reaction, and A (before polymerization) is the absorbance of the infrared absorption peak due to the polymerizable group before the polymerization reaction. . For example, when the polymerizable compound contained in the undercoat liquid and / or the ink liquid is an acrylate monomer or a methacrylate monomer, an absorption peak based on a polymerizable group (acrylate group, methacrylate group) can be observed in the vicinity of 810 cm ^−1. The unpolymerized rate is preferably defined by the absorbance of the peak. When the polymerizable compound is an oxetane compound, an absorption peak based on a polymerizable group (oxetane ring) can be observed in the vicinity of 986 cm ⁻¹ , and the unpolymerization rate is preferably defined by the absorbance of the peak. When the polymerizable compound is an epoxy compound, an absorption peak based on a polymerizable group (epoxy group) can be observed in the vicinity of 750 cm ⁻¹ , and the unpolymerization rate is preferably defined by the absorbance of the peak.

  As a means for measuring the infrared absorption spectrum, a commercially available infrared spectrophotometer can be used, which may be either a transmission type or a reflection type, and is preferably selected as appropriate in the form of a sample. For example, it can be measured using an infrared spectrophotometer FTS-6000 manufactured by BIO-RAD.

As a method of semi-curing the undercoat liquid composition, a method of causing a curing reaction by applying actinic radiation to the undercoat liquid of the undercoat liquid composition is preferable.
As the actinic radiation, in addition to ultraviolet rays, for example, visible light, α rays, γ rays, X rays, electron rays, and the like can be used. Among these, as the active radiation, ultraviolet rays and visible rays are preferable and ultraviolet rays are particularly preferable from the viewpoint of cost and safety.
The amount of energy required for semi-curing the undercoat liquid and / or the colored liquid varies depending on the composition, particularly the type and content of the photopolymerization initiator, but is preferably about 1 to 500 mJ / cm ² .
Suitable devices for irradiating actinic radiation include metal halide lamps, mercury lamps, LED light sources and the like.

<The process of providing a colored liquid composition on a recording medium>
In the present invention, the semi-cured undercoat liquid composition and / or the colored liquid composition discharged onto the colored liquid composition film has a droplet size of 0.1 pL (picoliter; the same applies hereinafter) to 100 pL ( It is preferable that droplets are ejected (preferably by an inkjet nozzle). More preferably, it is 0.5 pL or more and 50 pL or less. When the droplet size is within the above range, it is effective in that an image with high sharpness can be drawn with a small amount of a colored liquid composition.

After applying the undercoat liquid composition, the droplet ejection interval until the droplet of the colored liquid composition is ejected is preferably in the range of 5 μs or more and 10 seconds or less. The droplet ejection interval of the ink droplets is more preferably 10 μs to 5 seconds, and particularly preferably 20 μs to 5 seconds.
When the droplet ejection interval is within the above range, it is effective in that the effect of the present invention can be remarkably exhibited.

  As a means for applying the colored liquid composition, an ink jet head is preferably used. As an inkjet head, for example, a charge control method that ejects ink using electrostatic attraction, a drop-on-demand method (pressure pulse method) that uses the vibration pressure of a piezo element, and an electrical signal is converted into an acoustic beam into ink A head such as an acoustic ink jet system that irradiates and ejects ink using radiation pressure, or a thermal ink jet (bubble jet (registered trademark)) system that uses ink to form bubbles by heating the ink is suitable. It is.

<Step of curing only half of colored liquid composition (first exposure)>
The “semi-curing” of the colored liquid composition in the present invention is as described above.
As a method of curing only the inside of the colored liquid composition, it is preferable to select and use a method similar to the method of semi-curing the undercoat liquid composition as appropriate.

<Step of completely curing image (second exposure)>
The “fully cured” in the present invention refers to a state in which the inside and the surface of the liquid composition are completely cured. Specifically, after completion of the complete curing process (for example, after irradiation with actinic radiation or after heating), determine whether or not the surface of the undercoat liquid has been transferred to the penetrating medium by pressing the penetrating medium such as plain paper. Can do. That is, the case where no transfer is performed is called a completely cured state.

  As the curing means for curing the image, a light source for irradiating active radiation, a heater such as an electric heater or an oven, and the like can be selected according to the purpose.

As the actinic radiation, in addition to ultraviolet rays, for example, visible light, α rays, γ rays, X rays, electron beams, and the like can be used. Among these, as the active radiation, ultraviolet rays and visible rays are preferable and ultraviolet rays are particularly preferable from the viewpoint of cost and safety.
The amount of energy required for complete curing varies depending on the composition, particularly the type and content of the photopolymerization initiator, but is preferably about 100 to 10,000 mJ / cm ² . Suitable devices for irradiating actinic radiation include metal halide lamps, mercury lamps, LED light sources and the like.

<First exposure and second exposure>
In the ink jet recording method of the present invention, the light intensity spectrum (spectral energy distribution) of the first exposure is different from the light intensity spectrum (spectral energy distribution) of the second exposure. The light intensity spectrum (spectral energy distribution) refers to the wavelength dependence of the intensity of light emitted from a light source.
The light intensity spectrum (spectral energy distribution) is different, for example, when the intensity of light emitted from the exposure light source is plotted on the vertical axis and the wavelength is plotted on the horizontal axis, the first exposure light source and the second It means that the shape of the graph differs depending on the exposure light source. As a result, the curability of the colored liquid composition and the undercoat liquid composition is different between the first exposure process and the second exposure process.
Specific determination as to whether the light intensity spectrum (spectral energy distribution) is different can be made as follows.
Integrated illuminance in UVA (320 to 390 nm) and UVC (250 to 260 nm) of the first exposure light source and the second exposure light source, UVA (I), UVA (II), UVB (I), UVB (II), Measure with an ultraviolet power meter,
UVA (I) / UVA (II) <0.5
Or UVB (I) / UVB (II) <0.5
If so, it can be determined that the light intensity spectra are different.
here,
UVA (I): intensity of light at 320 to 390 nm of the first exposure light source (mW / cm ² )
UVA (II): intensity of light at 320 to 390 nm of the second exposure light source (mW / cm ² )
UVB (I): intensity of light at 250 to 260 nm of the first exposure light source (mW / cm ² )
UVB (II): intensity of light at 250 to 260 nm of the second exposure light source (mW / cm ² )
It is.
In addition, as said ultraviolet power meter, it can measure using UV PowerMAP (EIT company), spectroradiometer URS-40D (made by Ushio Electric), etc.

As a combination of the first exposure and the second exposure, the intensity of light at a wavelength of 255 nm of the first exposure light source is 1 mW / cm ² or less, and at a wavelength of 255 nm of the second exposure light source. The light intensity is preferably 10 mW / cm ² or more.
As a combination of the first exposure and the second exposure, the intensity of light at a wavelength of 255 nm of the first exposure light source is 1 mW / cm ² or less, and the 255 nm of the second exposure light source is 255 nm. The intensity of light at a wavelength is 10 mW / cm ² or more, the intensity of light at a wavelength of 365 nm of the first exposure light source is 10 mW / cm ² or more, and the wavelength of 365 nm of the second exposure light source More preferably, the light intensity at is 10 mW / cm ² or more.

<Image recording principle and recording apparatus>
Next, an example of the principle of the present invention for forming an image on a recording medium while avoiding droplet ejection interference will be described with reference to FIG.
First, as shown in FIG. 9A, the undercoat liquid composition is applied to the recording medium 80, and a liquid film 81 made of the undercoat liquid composition is formed on the surface of the recording medium 80. Such an application mode of the undercoat liquid composition is shown in FIG. 9 as an application mode, but may be any mode such as droplet ejection (also referred to as “ejection”) by an ink jet head or spray application.

  The thickness of the liquid film of the applied undercoat liquid composition is an average thickness obtained by dividing the volume of the applied undercoat liquid composition by the area of the portion to which the undercoat liquid composition has been applied. When the undercoat liquid composition is applied by droplet ejection, it can be determined from the volume of droplet ejection and the area of the portion where the undercoat liquid composition is deposited. The thickness of the liquid film of the undercoat liquid composition is desirably uniform and does not have a local difference in thickness. From this point of view, it is desirable that the physical property of the undercoat liquid composition that easily spreads on the recording medium, that is, the static surface tension is small, within a range where the ink jet head can stably discharge.

  Next, as shown in FIG. 9B, only the inside of the undercoat liquid composition was cured by irradiation with actinic radiation from the light source W (103P) (semi-cured film; 81a, internally cured film; 81b). The colored liquid composition 82a is ejected. By this droplet ejection, as shown in FIG. 9C, the colored liquid composition 82a is landed on the undercoat liquid composition film 81. At this time, since the surface of the undercoat liquid composition is not cured or is in a semi-cured state, it is easily compatible with the colored liquid composition 82a.

  Further, as shown in FIG. 9 (d), the landing position of the first droplet 82a landed first in the region where the liquid film 81 made of the undercoat liquid composition exists on the recording medium 80. The subsequent colored liquid composition 82b is ejected in the vicinity. At this time, since the surface of the undercoat liquid composition is not cured or is in a semi-cured state, it is easily compatible with the colored liquid composition 82b. Although the force which tries to unite with respect to the coloring liquid composition 82a and the coloring liquid composition 82b works, the adhesiveness of the surface of the coloring liquid composition and the undercoat liquid composition is good and the cured state when trying to unite The undercoating liquid composition in the interior becomes a resistance against coalescence between the colored liquid composition droplets, thereby suppressing droplet ejection interference.

  Conventionally, in order to avoid droplet ejection interference, a material that causes a chemical reaction in which the colorant contained in the ink composition agglomerates or insolubilizes has been included in the undercoat liquid composition. Without adding such a substance to the undercoat liquid composition, it is possible to avoid droplet ejection interference.

  Further, as shown in FIG. 9D, while the droplet ejection interference is avoided and the shapes of the colored liquid compositions 82a and 82b are maintained (in the case of the present invention, several hundred milliseconds to 5 seconds), that is, While the dot shape does not collapse, the colored liquid compositions 82a and 82b are cured or semi-cured to such an extent that the shape does not collapse, and the colorant in the colored liquid compositions 82a and 82b is fixed to the recording medium 80. At least the colored liquid composition contains an actinic radiation curable polymerizable compound, and is cured by a so-called polymerization reaction when irradiated with actinic radiation such as ultraviolet rays. The undercoat liquid composition can also contain a polymerizable compound, and since the entire discharged liquid is cured, it is preferable for improving the adhesion.

Next, the overall configuration of an inline label printer, which is an example of an image recording apparatus equipped with an inkjet recording apparatus that can be used in the inject recording method of the present invention, will be described with reference to the drawings.
FIG. 10 is an overall configuration diagram illustrating an example of an inline label printer (image recording apparatus) 100. The image recording apparatus 100 is a buffer unit between the inkjet recording unit 100A of the present invention, a post-processing unit 100B that performs post-processing on the drawn recording medium, and the inkjet recording unit 100A and the post-processing unit 100B. It consists of a buffer 104.

  The ink jet recording apparatus that can be used in the present invention is applied to the ink jet recording unit 100A. The ink jet recording unit 100A includes an undercoat liquid composition film forming unit 100A1 for forming a semi-cured undercoat liquid composition film on a recording medium (label) 80, and four types of colored liquid compositions including a colorant. The drawing unit 100 </ b> A <b> 2 forms a desired image on the recording medium 80 by giving it to a predetermined position of the recording medium 80.

  As the recording medium, there is a recording medium that is not particularly permeable (for example, OPP (Oriented Polypropylene Film), CPP (Casted Polypropylene Film), PE (Polyethylene), PET (Polyethylene terephthalate), PP (Poly), and PP (Poly). A good image can be formed when a low soft packaging material, laminated paper, coated paper, art paper, or the like is used.

In FIG. 10, an ink jet recording unit 100A includes a drawing unit 100A2 that applies an undercoat liquid composition with a roll coater 102P and applies a colored liquid composition to a recording medium 80 by ink jet droplets.
The image recording apparatus 100 also includes a light-shielded liquid storage / loading unit (not shown) that stores the undercoat liquid composition and the colored liquid composition supplied to the undercoat liquid composition film forming unit 100A1 and the drawing unit 100A2. A paper feed unit 101 that supplies the recording medium 80, an image detection unit 104c that reads an image as a result of droplet deposition of the colored liquid composition by the drawing unit 100A2 (the landing state of the colored liquid composition droplets), and a recorded image A take-up unit 109 for taking up the recording medium.

  In FIG. 10, as an example of the paper feeding unit 101, a paper that feeds roll paper (continuous paper) is shown, but a paper that feeds cut paper that has been cut in advance may be used.

  The ink jet recording unit 100A will be further described. The ink jet recording unit 100A includes a droplet ejection head 102Y, 102C, 102M, 102K for the colored liquid composition that ejects the colored liquid composition onto the recording medium 80 in a single pass, and a pinning light source 103Y, 103C, 103M, and final curing. The drawing unit 100A2 includes the light source 103F, and the undercoat liquid composition film forming unit 100A1 includes the roll coater 102P and the semi-curing light source 103P.

More specifically, a so-called full line type head in which a line type head having a length corresponding to the entire recordable width of the recording medium 80 is arranged in a direction orthogonal to the medium conveying direction (indicated by an arrow S in FIG. 10). It is a head.
Also, in the figure, pinning light sources 103Y, 103C, and 103M are disposed downstream of each of 102Y, 102C, and 102M to cure the dots ejected with the respective colored liquid compositions so that at least the dot shape does not collapse. Yes.
The roll coater and each of the droplet ejection heads 102Y, 102C, 102M, and 102K include a coater and a plurality of nozzles (liquid ejection ports) over a length that exceeds at least one side of the maximum size recording medium 80 targeted by the ink jet recording unit 100A. It is arranged.
Further, along the medium transport direction S, from the upstream side (left side in FIG. 10), the yellow colored liquid composition (Y), the cyan colored liquid composition (C), and the magenta colored liquid composition ( M) and the black colored liquid composition (K) are arranged in the order of droplet ejection heads 102Y, 102C, 102M, and 102K corresponding to the liquids, and a color image can be formed on the recording medium 80.

  Specifically, first, the undercoat liquid composition is uniformly applied to the recording medium 80 by the roll coater (102P), and the undercoat liquid composition is internally cured by the internal curing ultraviolet light source 103P. Next, the yellow liquid composition is ejected from the yellow liquid composition droplet ejection head 102Y toward the recording medium 80, and the yellow liquid composition on the recording medium is formed by the pinning light source 103Y disposed downstream of the head 102Y. However, it is internally cured to such an extent that the surface is not cured and at least the shape thereof does not collapse. Subsequently, the same processes as those of the yellow liquid composition are repeated in the heads 102C and 102M, and finally the droplets are ejected by the droplet ejection head 102K for the black liquid composition, and then the undercoat liquid composition and all the colorings are produced. Curing is completed by a final curing light source 103F that has the ability to fully cure the liquid composition. Here, after applying the undercoat liquid composition and the colored liquid composition, only the inside thereof is cured, thereby preventing droplet ejection interference.

  Further, according to the drawing unit 100A2 composed of a full-line type droplet ejection head, the entire surface of the recording medium 80 can be obtained by performing the operation of relatively moving the recording medium 80 and the drawing unit 100A2 in the medium transport direction only once. Can record images. Thereby, high-speed printing is possible and productivity can be improved as compared with a shuttle type head that reciprocates a droplet ejection head in a direction orthogonal to the medium conveyance direction while conveying a recording medium.

  In the present embodiment, the configuration of the standard colors (four colors) of YCMK has been exemplified. However, the number of ink colors and color combinations are not limited to the examples shown in the present embodiment. Ink, dark ink, white or other special color ink, transparent ink, or the like may be added. For example, a configuration in which a droplet ejection head that discharges light-colored ink such as light cyan or light magenta is added, a configuration in which a background is drawn with white ink, or a glossiness adjustment with transparent ink is also possible.

The UV light sources 103P, 103Y, 103C, 103M, and 103F irradiate the recording medium 80 with ultraviolet rays in order to cure the ink composition containing the polymerizable compound.
As the ultraviolet exposure light source, a known light source such as a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, a xenon lamp, a carbon arc lamp, an ultraviolet fluorescent lamp, an ultraviolet LED, and an ultraviolet LD can be used.
In the present invention, the first exposure light source is preferably an LED light source. The second exposure light source is preferably a high-pressure mercury lamp, an ultra-high pressure mercury lamp, or a metal halide lamp from the viewpoint of practicality.
The UV light source preferably has a light intensity peak in the wavelength range of 200 nm to 400 nm, and preferably has a light intensity in the range of 1 to 500 mW / cm ² at the light intensity peak wavelength. The UV light source preferably uses a cold mirror for the reflector and an infrared cut glass for the cover glass to prevent a temperature rise of the recording medium due to heat ray irradiation.
Here, although omitted in FIG. 10, in the ink composition containing the radical polymerizable compound, the inhibition of polymerization by oxygen is suppressed by replacing the curing atmosphere by the final curing light source 103F with an inert gas (such as nitrogen). Better curing and fixing of the ink composition can be performed.

  Although not shown, an electron beam irradiation device may be used as a means for curing the ink composition containing a polymerizable compound.

  In the above, examples of the UV light source and the electron beam irradiation apparatus are exemplified as means for curing the polymerizable compound, but these means are not limited to the examples shown here, and other radiation rays such as α Lines, γ-rays, X-rays, etc. may be used.

  The image detection unit 104c includes an image sensor (line sensor or the like) for imaging the droplet ejection result of the drawing unit 100A2, and functions as a unit that checks nozzle clogging and other ejection abnormalities from an image read by the image sensor. To do.

  There is a buffer 104 as a buffer section between the ink jet recording section 100A and the post-processing section 100B. The recording material on which ink jet recording has been performed passes up and down several times through a buffer 104 composed of several upper rollers 104a and several lower rollers 104b. The buffer 104 is an adjustment unit that absorbs the difference between the speeds of the upstream inkjet recording unit 100A and the downstream post-processing unit 100B (to be described later) (the transport speed of the recording medium 80).

A varnish coater 105 is downstream of the buffer 104. The varnish coater 105 applies a thin varnish to the label surface to improve the scratch resistance of the label surface.
The label cutting unit 106 downstream of the varnish coater 105 includes a marking reader 106a, a die cutter driver 106b, a die cutter 106c equipped with a roll (plate) 106e having a blade, and a counter roller 106d.

  The label cut by the die cutter 106c of the label cutting unit 106 is wound downstream of the branch roller 107 as a product label by the label take-up unit 109, and other debris is peeled off and discarded by the debris removal unit 108. Discard as waste.

<Structure of droplet ejection head>
FIG. 11A shows an example of the basic overall structure of the droplet ejection head 50 with reference numeral 50 assigned to the droplet ejection heads representing the droplet ejection heads 102Y, 102C, 102M, and 102K shown in FIG. FIG.
The droplet ejection head 50 shown as an example in FIG. 11A is a so-called full-line head, and is a direction (in the drawing) orthogonal to the conveyance direction of the recording medium 80 (the sub-scanning direction indicated by the arrow S in the drawing). In a main scanning direction indicated by an arrow M), a number of nozzles 51 (liquid ejection ports) that eject liquid toward the recording medium 80 are two-dimensionally formed over a length corresponding to the width Wm of the recording medium 80. It has an arrayed structure.

  The droplet ejection head 50 includes a nozzle 51, a pressure chamber 52 communicating with the nozzle 51, and a plurality of pressure chamber units 54 including a liquid supply port 53 with respect to the main scanning direction M and the main scanning direction M. They are arranged along two oblique directions forming an acute angle θ (0 degree <θ <90 degrees). In FIG. 11A, only a part of the pressure chamber units 54 is shown for convenience of illustration.

  Specifically, the nozzles 51 are arranged at a constant pitch d in an oblique direction that forms a predetermined acute angle θ with respect to the main scanning direction M, and thus, “on a straight line along the main scanning direction M” d × cos θ ”can be handled equivalently.

FIG. 11B is a cross-sectional view taken along the line bb in FIG. 11A with respect to the pressure chamber unit 54 described above as one ejection element constituting the droplet ejection head 50.
As shown in FIG. 11B, each pressure chamber 52 communicates with a common liquid chamber 55 through a liquid supply port 53. The common liquid chamber 55 communicates with a tank which is a liquid supply source (not shown), and the liquid supplied from the tank is distributed and supplied to each pressure chamber 52 via the common liquid chamber 55.

A piezoelectric body 58a is disposed on the diaphragm 56 constituting the top surface of the pressure chamber 52, and an individual electrode 57 is disposed on the piezoelectric body 58a. The diaphragm 56 is grounded and functions as a common electrode. These diaphragm 56, individual electrode 57 and piezoelectric body 58a constitute a piezoelectric actuator 58 as means for generating a liquid ejection force.
When a predetermined drive voltage is applied to the individual electrode 57 of the piezoelectric actuator 58, the piezoelectric body 58a is deformed to change the volume of the pressure chamber 52, and the pressure in the pressure chamber 52 is changed accordingly. Liquid is discharged. After the liquid is discharged, when the volume of the pressure chamber 52 is restored, a new liquid is supplied from the common liquid chamber 55 through the liquid supply port 53 to the pressure chamber 52.

FIG. 11A shows an example in which a plurality of nozzles 51 are two-dimensionally arranged as a structure capable of forming a high-resolution image on the recording medium 80 at a high speed. The droplet ejection head is not particularly limited to a structure in which a plurality of nozzles 51 are two-dimensionally arranged, and may have a structure in which a plurality of nozzles 51 are one-dimensionally arranged. Further, the pressure chamber unit 54 shown in FIG. 11B as an ejection element constituting the droplet ejection head is an example, and is not particularly limited to such a case. For example, instead of disposing the common liquid chamber 55 below the pressure chamber 52 (that is, the discharge surface 50a side than the pressure chamber 52), the common liquid is disposed above the pressure chamber 52 (that is, opposite to the discharge surface 50a). The chamber 55 may be disposed. Further, for example, instead of using the piezoelectric body 58a, a liquid discharge force may be generated using a heating element.
In the ink jet recording apparatus of the present invention, as means for applying the undercoat liquid onto the recording medium, other means such as ejection of the undercoat liquid from the nozzle may be used in addition to the application.
There is no restriction | limiting in particular as an apparatus used for the said application | coating, A well-known coating apparatus can be suitably selected according to the objective. Examples include air doctor coaters, blade coaters, lot coaters, knife coaters, squeeze coaters, impregnation coaters, reverse roll coaters, transfer roll coaters, gravure coaters, kiss roll coaters, cast coaters, spray coaters, curtain coaters, extrusion coaters, etc. It is done.

<Liquid supply system>
FIG. 12 is a schematic diagram showing the configuration of the liquid supply system in the image recording apparatus 100.
The liquid tank 60 is a base tank for supplying a liquid composition to the droplet ejection head 50. A liquid supply pump 62 that feeds the liquid composition from the liquid tank 60 to the droplet ejection head 50 is provided in the middle of the conduit that connects the liquid tank 60 and the droplet ejection head 50. It is preferable that the temperature of the liquid tank 60 and the droplet ejection head 50 and the pipe connecting the both are adjusted together with the ink inside by the temperature detection means and the heater. The ink temperature at this time is preferably adjusted to 40 ° C to 80 ° C.

  The image recording apparatus 100 also includes a cap 64 as a means for preventing the meniscus from drying out of the nozzle 51 or preventing an increase in viscosity in the vicinity of the meniscus during a long discharge pause period, and a cleaning as a means for cleaning the discharge surface 50a. A blade 66 is provided. The maintenance unit including the cap 64 and the cleaning blade 66 can be moved relative to the droplet ejection head 50 by a moving mechanism (not shown), and if necessary, a maintenance position below the droplet ejection head 50 from a predetermined retraction position. To be moved to.

The cap 64 is moved up and down relatively with respect to the droplet ejection head 50 by a lifting mechanism (not shown). The elevating mechanism raises the cap 64 to a predetermined ascending position and contacts the droplet ejection head 50 to cover at least the nozzle region of the ejection surface 50a with the cap 64.
Preferably, the inside of the cap 64 is divided into a plurality of areas corresponding to the nozzle rows by a partition wall, and each of the partitioned areas can be selectively sucked by a selector or the like.

The cleaning blade 66 is made of an elastic member such as rubber, and can slide on the ejection surface 50a of the droplet ejection head 50 by a cleaning blade moving mechanism (not shown). When droplets or foreign matter adhere to the discharge surface 50a, the discharge surface 50a is wiped by sliding the cleaning blade 66 on the discharge surface 50a, and the discharge surface 50a is cleaned.
The suction pump 67 sucks the liquid from the nozzle 51 of the droplet ejection head 50 in a state where the discharge surface 50 a of the droplet ejection head 50 is covered with the cap 64, and sends the sucked liquid to the recovery tank 68.

Such a suction operation is stopped for a long time in addition to the case where the liquid tank 60 is loaded in the image recording apparatus 100 and liquid is filled from the liquid tank 60 to the droplet ejection head 50 (at the time of initial filling), and the viscosity is increased by stopping for a long time. It is also performed when removing the liquid (when starting to use for a long time).
Here, when the discharge from the nozzle 51 is arranged, firstly, there is normal discharge performed toward the recording medium in order to form an image on the recording medium such as paper, and second, the cap 64. Is purged toward the cap 64 as a liquid receiver (also referred to as idle discharge).

Further, if bubbles are mixed in the nozzle 51 or the pressure chamber 52 of the droplet ejection head 50 or if the viscosity increase in the nozzle 51 exceeds a certain level, the liquid cannot be ejected from the nozzle 51 by the above-described empty ejection. An operation in which the cap 64 is applied to the ejection surface 50a of the droplet ejection head 50 and the liquid in which the bubbles in the pressure chamber 52 of the droplet ejection head 50 are mixed or the thickened liquid is sucked by the suction pump 67 is performed.
Here, the droplet ejection head 50, the liquid tank 60, the liquid supply pump 62, the cap 64, the cleaning blade 66, the suction pump 67, the recovery tank 68, the ink flow path connecting them, and other members and equipment that are directly touched by ink It preferably has dissolution resistance and swelling resistance. Moreover, it is preferable that these members and devices have light shielding properties.

<Control system>
FIG. 13 is a principal block diagram showing the system configuration of the image recording apparatus 100.
In FIG. 13, an image recording apparatus 100 mainly includes a drawing unit 102, an image detection unit 104c, a UV light source 103, a communication interface 110, a system controller 112, a memory 114, an image buffer memory 152, a transport motor 116, and a motor driver 118. , Heater 122, heater driver 124, medium type detection unit 132, ink type detection unit 134, illuminance detection unit 135, environmental temperature detection unit 136, environmental humidity detection unit 137, medium temperature detection unit 138, liquid supply unit 142, liquid supply The driver 144, the print controller 150, the head driver 154, and the light source driver 156 are configured.
The drawing unit 102 represents the droplet ejection heads 102Y, 102C, 102M, and 102K shown in FIG. 10, and the UV light source 103 represents the curing light sources 103P, 103Y, 103C, 103M, and 103F shown in FIG. Since the image detection unit 104c is the same as that described in FIG. 10 and has already been described, description thereof is omitted here.

  The communication interface 110 is an image data input unit that receives image data transmitted from the host computer 300. As the communication interface 110, a wired or wireless interface such as USB (Universal Serial Bus) or IEEE1394 can be applied. The image data input to the image recording apparatus 100 via the communication interface 110 is temporarily stored in the first memory 114 for storing image data.

  The system controller 112 includes a central processing unit (CPU) and its peripheral circuits, and is main control means for controlling the entire image recording apparatus 100 according to a predetermined program stored in the first memory 114 in advance. That is, the system controller 112 controls each unit such as the communication interface 110, the motor driver 118, the heater driver 124, the medium type detection unit 132, the ink type detection unit 134, and the print control unit 150.

  A conveyance motor 116 applies power to a roller, a belt, or the like for conveying a recording medium. By this conveyance motor 116, the droplet ejection head 50 constituting the drawing unit 102 and the recording medium move relatively. The motor driver 118 is a circuit that drives the conveyance motor 116 in accordance with an instruction from the system controller 112.

  The heater 122 is a circuit that drives a heater (or cooling element) 122 (not shown), and maintains the temperature of the recording medium at a constant temperature. The heater driver 124 is a circuit that drives the heater 122 in accordance with an instruction from the system controller 112.

  The medium type detection unit 132 detects the type of the recording medium. There are various detection modes for the type of recording medium. For example, a mode in which a sensor is provided in a sheet feeding unit (not shown), a mode in which the sensor is input by a user operation, a mode in which the sensor is input from the host computer 300, and image data input from the host computer 300 There is a mode in which automatic detection is performed by analyzing (for example, resolution and color) or additional data of the image data.

  The ink type detection unit 134 detects the type of ink. There are various types of ink type detection modes. For example, a mode in which a sensor is provided in a liquid storage / loading unit (not shown), a mode in which input is performed by a user's operation, a mode in which data is input from the host computer 300, and a mode in which input is performed from the host computer 300 There is a mode in which image data (for example, resolution and color) or additional data of the image data is automatically detected by analysis.

The illuminance detection unit 135 detects the illuminance of ultraviolet rays emitted from the UV light source 103. As an illuminance detection mode, for example, an illuminance sensor is provided in the vicinity of the UV light source 103 in FIG. Based on the output of the illuminance sensor, the output of the UV light source is fed back.
The environmental temperature detection unit 136 detects the temperature of the outside air or the image recording apparatus. As an environmental temperature detection mode, for example, there is a mode of detection by providing a temperature sensor outside or inside the device.
The environmental humidity detector 137 detects the outside air or the humidity inside the image recording apparatus. As an environmental humidity detection mode, for example, there is a mode of detection by providing a humidity sensor outside or inside the device.
The medium temperature detection unit 138 detects the temperature at the time of image formation on the recording medium. There are various medium temperature detection modes. For example, there are a mode in which a contact type temperature sensor is provided for detection, and a mode in which a non-contact type temperature sensor is provided above the recording medium 80 for detection, and the temperature of the recording medium is kept constant by the heater 122 described above. .

The liquid supply unit 142 includes a conduit for flowing ink from the liquid tank 60 in FIG. 12 to the drawing unit 102, a liquid supply pump 62, and the like.
The liquid supply driver 144 is a circuit that drives the liquid supply pump 62 and the like constituting the liquid supply unit 142 so that the liquid is supplied to the drawing unit 102.

Based on the image data input to the image recording apparatus 100, the print control unit 150 is data necessary for each droplet ejection head 50 constituting the drawing unit 102 to eject (droplet ejection) toward the recording medium. (Droplet ejection data) is generated. That is, the print control unit 150 functions as an image processing unit that performs image processing such as various types of processing and correction for generating droplet ejection data from image data in the first memory 114 under the control of the system controller 112. The generated droplet ejection data is supplied to the head driver 154.
The print controller 150 is accompanied by a second memory 152, and droplet ejection data and the like are temporarily stored in the second memory 152 during image processing in the print controller 150.

  In FIG. 13, the second memory 152 is shown in a form associated with the print control unit 150, but it can also be used as the first memory 114. Also possible is an aspect in which the print controller 150 and the system controller 112 are integrated and configured with one processor.

  The head driver 154 applies the droplet ejection data provided from the print control unit 150 (actually, the droplet ejection data stored in the second memory 152) to each droplet ejection head 50 constituting the drawing unit 102. To output an ejection drive signal. The ejection drive signal output from the head driver 154 is applied to each droplet ejection head 50 (specifically, the actuator 58 shown in FIG. 11B), so that the droplet ejection head 50 is directed toward the recording medium. Liquid (droplet) is discharged.

  The light source driver 156 detects an instruction from the print control unit 150, the illuminance detected by the illuminance detection unit 135, the environmental temperature detected by the environmental temperature detection unit 136, the environmental humidity detected by the environmental humidity detection unit 137, and the medium temperature detection. This is a circuit that controls the voltage, time, and timing input to the UV light source 103 based on the medium temperature detected by the unit 138 and drives the UV light source 103.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not restrict | limited to these. In the following description, “parts” means “parts by weight” unless otherwise specified.

(Preparation of cyan pigment dispersion)
16 parts of PB15: 3 (IRGALITE BLUE GLO, manufactured by Ciba Specialty Chemicals), 48 parts of 1,6-hexanediol diacrylate (manufactured by Daicel Cytec), and 16 parts of BYK-168 (manufactured by BYK Chemie) Mix and stir for 1 hour. The mixture after stirring was dispersed with an Eiger mill to obtain Pigment Dispersion A. Dispersion conditions were as follows: zirconia beads having a diameter of 0.65 mm were filled at a filling rate of 70%, the peripheral speed was 9 m / s, and the dispersion time was 1 hour. Cyan pigment dispersion A was obtained through the above steps.

(Preparation of magenta pigment dispersion)
The magenta dispersion was prepared by changing the pigment from PB15: 3 (IRGALITE BLUE GLO; manufactured by Ciba Specialty Chemicals) to PV19 (CINQUASIA MAGENTA RT-355D; manufactured by Ciba Specialty Chemicals). This was carried out in the same manner as the preparation of the cyan pigment dispersion except that the dispersant was changed to BYK-168 (manufactured by Big Chemie).

(Preparation of yellow pigment dispersion)
The yellow dispersion was prepared by changing the pigment from PB15: 3 (IRGALITE BLUE GLO; manufactured by Ciba Specialty Chemicals) to PY120 (NOVOPERM YELLOW H2G; manufactured by Clariant). Except for changing to BYK-168 (manufactured by Big Chemie), the same procedure as in the preparation of the cyan pigment dispersion was performed.

(Preparation of black pigment dispersion)
The black dispersion was prepared by changing the pigment from PB15: 3 (IRGALITE BLUE GLO; manufactured by Ciba Specialty Chemicals) to carbon black (SPECIAL BLACK 250; manufactured by Degussa). Was changed to Solsperse 5000 (manufactured by Zeneca Corporation) in the same manner as the preparation of the cyan pigment dispersion.

(Preparation of liquid composition)
The components shown in Table 1 were stirred, mixed and dissolved to obtain a liquid composition. In addition, when the surface tension of these liquid compositions was measured at a liquid temperature of 25 ° C. by the Wilhelmy method using a surface tension meter (manufactured by Kyowa Interface Science Co., Ltd., surface tension meter CBVP-Z, etc.) The surface tension of the colored liquid composition was also in the range of 23 to 25 mN / m. On the other hand, the surface tension of the transparent liquid composition was in the range of 20 to 22 mN / m.

The compositions of the magenta colored liquid compositions M1 to M4 are shown in Table 1-1.
The compositions of the cyan colored liquid compositions C1 to C4 are shown in Table 1-2.
Tables 1-3 show the compositions of the yellow colored liquid compositions Y1 to Y4.
The compositions of the black colored liquid compositions Bk1 to Bk4 are shown in Table 1-4.
The compositions of the transparent colored liquid compositions L1 to L4 are shown in Table 1-5.

The compounds described in Table 1-1 to Table 1-5 are as follows.
Polymerizable compound A: DPGDA (multifunctional monomer manufactured by Daicel-Cytec)
Polymerizable compound B: DPCA60 (Nippon Kayaku Co., Ltd. polyfunctional monomer)
Surfactant A: BYK-307 (Surfactant manufactured by Big Chemie)
Photopolymerization initiator A: Irgacure 184 (photopolymerization initiator manufactured by Ciba Specialty Chemicals)
Photopolymerization initiator B: Darocur 1173 (photopolymerization initiator manufactured by Ciba Specialty Chemicals)
Photopolymerization initiator C: Irgacure 369 (Photopolymerization initiator manufactured by Ciba Specialty Chemicals)
Photopolymerization initiator D: Irgacure 819 (photopolymerization initiator manufactured by Ciba Specialty Chemicals)

  The photopolymerization initiators A to D were dissolved in an acetonitrile solution at a concentration of 0.1% by weight, and the absorbance (optical path length: 1 cm) of the solution with respect to wavelengths of 365 nm and 255 nm was measured with a spectrophotometer (V560 manufactured by JASCO Corporation). Table 2 shows the values measured in (1).

(Image recording device)
The prepared colored liquid compositions for four colors (M1 to M4, C1 to C4, Y1 to Y4, Bk1 to Bk4) are ink jet printers (head mounted by Toshiba Tec Corporation = droplet ejection frequency: 6.2 KHz, number of nozzles: 636, Nozzle density: 300 npi (nozzle / inch, the same applies below), Drop size: 4 sets of headsets with a full line arrangement of two variable heads arranged in 7 stages to 600 npi) Loaded.
The head was fixed to the machine in the order of yellow, cyan, magenta, and black from the upstream side of the recording medium conveyance direction, and an undercoat liquid roll coater and exposure light source 1 were installed upstream of the yellow ink head. Here, as the undercoat liquid, transparent liquid compositions (L1 to L4) were used.
The recording medium is configured to be movable directly under the head, and recording is performed for each of the yellow, cyan, and magenta heads loaded with the colored liquid compositions (M1 to M4, C1 to C4, and Y1 to Y4). An exposure light source 1 is arranged in each of the traveling directions of the medium, and an exposure light source 2 is installed downstream of the black ink head.
The recording medium was transported on a roll, and an image of 600 dpi × 600 dpi was formed on the recording medium. Here, a plastic film (YUPO synthetic paper) was used as a recording medium.

(Exposure light source)
Two types of light sources were used as the exposure light source. One is an LED light source A, and Nichia NCCU033 was used as the LED. This LED outputs ultraviolet light having a wavelength of 365 nm from one chip. When a current of about 500 mA is applied, light of about 100 mW is emitted from the chip. A plurality thereof were aligned in 7mm intervals, exposure intensity at the surface of the recording medium is, 365 nm light is about 300 mW / cm ^2, light 255nm was 0 mW / cm ^2.
The other used a metal halide lamp A. As a metal halide lamp, VZero140 manufactured by Integration Technology was used. This metal halide lamp exposes ultraviolet and visible light with a wavelength of 200 nm to 600 nm. The exposure intensity on the surface of the recording medium is about 600 mW / cm ² for 365 nm light, and the exposure intensity for light of 255 nm. Was about 300 mW / cm ² .
These exposure intensities were measured using a spectroradiometer URS-40D manufactured by USHIO.
Further, when the metal halide lamp A was incorporated into an ink jet printer (conveyance speed 400 mm / s) and the accumulated energy when exposed was measured with a UV measuring device (made by POWER PUCK EIT), the UVA accumulated energy was about 300 mJ / cm ^2. Met.

(Example 1)
First, using the above-described ink jet printer, image A (solid image of 600 × 600 dpi (solid image of cyan, magenta, and yellow)), image B (secondary color of 600 dpi (cyan and magenta, yellow and cyan, yellow) Magenta) line image) and image C (600 × 600 dpi primary color (cyan, magenta, yellow) solid image on a solid black image “Fuji” (Times New Roman, 30 pt)).

The printing procedure is <1> to <10> as follows.
<1> The transparent liquid composition (L1) was uniformly applied to a thickness of 5 μm with a roll coater (application speed: 400 mm / s).
<2> After applying the transparent liquid composition (L1), exposure was performed with the exposure light source 1, and the applied transparent liquid composition (L1) was in a semi-cured state.
<3> A yellow colored liquid composition (Y1) was applied to the recording medium to which the transparent liquid composition was applied by a yellow head to form a yellow image.
<4> Exposure was performed with the exposure light source 1 to make the yellow colored liquid composition semi-cured.
<5> A cyan colored liquid composition (C1) was applied on a recording medium by a cyan head to form a cyan image.
<6> Exposure was performed with the exposure light source 1, and the cyan colored liquid composition was in a semi-cured state.
<7> A magenta colored liquid composition (M1) was applied to the recording medium by a magenta head to form a magenta image.
<8> Exposure was performed with the exposure light source 1 to make the magenta colored liquid composition semi-cured.
<9> A black colored liquid composition (Bk1) was applied to the recording medium with a black head to form a black image.
<10> Exposure was performed with the exposure light source 2 to completely cure the image.

The exposure light source 1 used here is an LED light source A having a bright line at 365 nm. On the other hand, a metal halide lamp A was used as the exposure light source 2.
Here, the conveyance speed of the non-recording medium was 400 mm / s, and the ink liquid amount per dot was about 12 picoliters. When forming an image of a tertiary color (for example, cyan, magenta, and yellow), <8> and <9> were omitted in the above procedure. Further, when forming an image of a secondary color (for example, cyan and magenta), <3>, <4>, <8>, and <9> were omitted in the above procedure. When forming an image of a primary color (for example, yellow), <4> to <9> were omitted in the above procedure.

(Example 2, Comparative Examples 1-6)
As described in Table 3, an image was prepared in the same manner as in Example 1 except that the colored liquid composition and the transparent liquid composition were replaced, and the exposure light source 1 and the exposure light source 2 were replaced.

(Sensory evaluation of images)
Sensory evaluation of images A, B, and C was performed according to the following evaluation criteria. The results are shown in Table 3.
○ There was no droplet ejection interference, the solid image was uniform, and fine lines and characters could be drawn.
× Droplet interference occurred, the solid image became uneven, and the lines and characters were distorted.

(Evaluation of image fixability)
○ The film is completely cured and will not peel off or change in image quality even when rubbed with an eraser or cloth.
X The film was not completely cured, and when it was rubbed with an eraser or cloth, the film was peeled off or the image quality was disturbed.

<Measurement of transfer amount>
In Examples 1 and 2 and Comparative Examples 5 and 6, the maximum application amount of the colored liquid per unit area applied in the steps <3>, <5>, <7>, <9> is the same for each colored liquid. from 0.74 mg / cm ² was in the range of 0.87 mg / cm ^2.
Samples were extracted from the colored liquids in steps <3>, <5>, <7>, and <9> before applying droplets, and the weight of the uncured undercoat liquid was measured by a transfer test. 0.10 mg / cm ² to 0.12 mg / cm ² .
Therefore, the relationship between the weight M (undercoat liquid) per unit area of the uncured portion of the undercoat liquid layer and the maximum weight m (colored liquid) discharged per unit area is m (colored liquid) / 10 <M. (Undercoat liquid) <m (colored liquid) / 5.
Furthermore, the amount of uncured yellow colored liquid after exposure by the exposure light source 1 in step <4>, the amount of uncured cyan colored liquid after exposure by the exposure light source 1 in step <6>, and the exposure in step <8>. The uncured liquid amount of the magenta colored liquid after exposure by the light source 1 was measured by a transfer test after extracting a sample after each step. The amount of uncured liquid for any of the colored liquids was in the range of 0.10 mg / cm ² to 0.12 mg / cm ² .
Therefore, in a combination of colored liquids having different hues, the weight M (colored liquid A) of the colored liquid A uncured portion applied on the recording medium first and the unit area of the colored liquid B applied later. The relationship of the maximum weight m (colored liquid B) per unit was m (colored liquid B) / 10 <M (colored liquid A) <m (colored liquid B) / 5.

In Comparative Examples 1 to 4, the maximum amount of the colored liquid applied per unit area in the steps <3>, <5>, <7>, <9> is 0.74 mg / cm ² to 0 for each colored liquid. Within the range of .87 mg / cm ² .
Samples were extracted from the colored liquids in steps <3>, <5>, <7>, and <9> before applying droplets, and the weight of the uncured undercoat liquid was measured by a transfer test. The transfer of the undercoat liquid could not be confirmed.
Furthermore, the amount of uncured yellow colored liquid after exposure by the exposure light source 1 in step <4>, the amount of uncured cyan colored liquid after exposure by the exposure light source 1 in step <6>, and the exposure in step <8>. The uncured liquid amount of the magenta colored liquid after exposure by the light source 1 was measured by a transfer test after extracting a sample after each step. Transfer of the undercoat liquid could not be confirmed after any step.
The transfer test was conducted using plain paper (Fuji Xerox Co., Ltd., copy paper C2, product code V436) as a non-penetrable medium. The plain paper was pressed with a uniform force (500 to 1,000 mN / cm ² ) against the semi-cured undercoat liquid or semi-cured colored liquid on the recording medium that had been removed, and allowed to stand for about 1 minute. Thereafter, the plain paper was gently peeled off, and the uncured liquid amount was determined by measuring the weight of the plain paper.

<Cross-sectional observation of the obtained image>
The obtained image B and image C were cut with a microtome and observed with an optical microscope (Nikon optical microscope measuring microscope MM-40). A microtome (Leica Microtome RM2255) was used to obtain a section.

  As shown in FIG. 2, the primary color portion of the images obtained in Examples 1 and 2 has a part of the colored liquid cured product 12 appearing on the surface, and a part of it is an undercoat layer. I was diving into 14. In addition, an undercoat layer 14 was observed below the colored liquid cured product 12. Furthermore, it was confirmed that a uniform colored liquid cured layer was formed.

  Of the images obtained in Examples 1 and 2, the portion of the secondary color (when formed with the coloring liquid A and the coloring liquid B) is one portion of the colored liquid B cured product 22 as shown in FIG. Part of the surface appeared on the surface, and a part of the part was embedded in the colored liquid A layer 24. Further, a colored liquid A layer 24 was observed below the colored liquid B cured product 22. Moreover, the undercoat layer 14 was observed under the colored liquid cured product A24. Furthermore, formation of the cured layer 22 of the uniform colored liquid B and the cured layer 24 of the uniform colored liquid A was confirmed.

It is a cross-sectional schematic diagram which shows one embodiment of the printed matter obtained by droplet-dropping a colored liquid on the semi-hardened undercoat liquid layer. It is a cross-sectional schematic diagram which shows one embodiment of the printed matter obtained by droplet-dropping a coloring liquid on the undercoat liquid layer of an unhardened state. It is a cross-sectional schematic diagram which shows another embodiment of the printed matter obtained by depositing a coloring liquid on the uncured undercoat liquid layer. It is a cross-sectional schematic diagram which shows one embodiment of the printed matter obtained by depositing a coloring liquid on the undercoat liquid layer of a completely hardened state. It is a cross-sectional schematic diagram which shows one embodiment of the printed matter obtained by depositing the coloring liquid B on the semi-cured coloring liquid A. It is a cross-sectional schematic diagram which shows one embodiment of the printed matter obtained by ejecting the coloring liquid B on the uncured coloring liquid A. It is a cross-sectional schematic diagram which shows other one Embodiment of the printed matter obtained by droplet-dropping the coloring liquid B on the uncured coloring liquid A. It is a cross-sectional schematic diagram which shows one embodiment of the printed matter obtained by depositing the coloring liquid B on the coloring liquid A in a completely cured state. It is process drawing for demonstrating the image formation principle. 1 is a schematic cross-sectional view illustrating an overall configuration of an image recording apparatus that records an image by an inkjet recording method of the present invention. (A) is a top view which shows the example of the fundamental whole structure of the droplet ejection head of FIG. 10, (b) is the bb sectional view taken on the line of (a). It is the schematic which shows the structural example of the liquid supply system which comprises an image recording device. It is a block diagram which shows the structural example of the control system which comprises an image recording device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image 12 Colored liquid cured | curing material 14 Undercoat layer 16 to which coloring liquid was given to undercoat liquid layer of semi-hardened base material 18 Undercoat layer 20 to which coloring liquid was given to undercoat liquid layer of uncured undercoat Undercoat layer 22 with colored liquid applied to liquid layer Colored liquid B cured product 24 Colored liquid A cured product 26 obtained by applying colored liquid B to semi-cured colored liquid A 26 Uncolored colored liquid A Colored liquid A cured product 28 obtained by applying the colored liquid B Colored liquid A cured product 50 obtained by applying the colored liquid B to the completely cured colored liquid A 50 Droplet ejection head 50a Discharge surface 51 Nozzle 52 Pressure Chamber 53 Liquid supply port 54 Pressure chamber unit 55 Common liquid chamber 56 Vibration plate 57 Individual electrode 58 Piezoelectric actuator 58a Piezoelectric vibration plate 60 Liquid tank 62 Liquid supply pump 64 Cap 66 Cleaning blade 67 Suction Pump 68 Recovery tank 80 Recording medium 81 Undercoat liquid composition 81a Uncured or semi-cured undercoat liquid composition 81b Cured undercoat liquid composition 82a, 82b Colored liquid composition 100 Image recording apparatus 100A Inkjet recording unit 100A1 liquid Film forming unit 100A2 Drawing unit 102P Roll coater 102Y, 102C, 102M, 102K Colored liquid composition droplet ejection head 103P Undercoat liquid composition curing light source 103Y, 103M, 103C Pinning light source 103F Final curing light source 104 Buffer 104a Upper roller 104b Below Roller 104c Image detection unit 100B Post-processing unit 105 Varnish coater 106 Label cutting unit 106a Marking reader 106b Die cutter driver 106c Die cutter 106d Counter roller 106e Plate with blade 10 7 Branching roller 108 Waste removal unit 109 Label winding unit 110 Communication interface 112 System controller 114 Memory 116 Transport motor 118 Motor driver 122 Heater 124 Heater driver 132 Media type detection unit 134 Ink type detection unit 135 Illuminance detection unit 136 Environmental temperature Detection unit 137 Environmental humidity detection unit 138 Medium temperature detection unit 142 Liquid supply unit 144 Liquid supply driver 150 Print control unit 152 Image buffer memory 154 Head driver 156 Light source driver 300 Host computer

Claims (10)

Using a colored liquid composition containing at least a colorant, a polymerizable compound and a photopolymerization initiator, and an undercoat liquid composition containing at least a radical polymerizable compound and a photopolymerization initiator,
(1) The colored liquid composition contains at least two kinds of photopolymerization initiators having different spectral absorption spectra,
(2) The recording method includes applying the undercoat liquid composition onto a recording medium;
Applying the colored liquid composition onto a recording medium;
A first exposure step of semi-curing the colored liquid composition and / or the undercoat liquid composition;
At least a second exposure step of completely curing the colored liquid composition and the undercoat liquid composition,
(3) The inkjet recording method, wherein the spectral energy distribution of the first exposure light source is different from the spectral energy distribution of the second exposure light source.   The inkjet recording method according to claim 1, wherein the step of applying the undercoat liquid composition onto the recording medium is performed prior to the step of applying the colored liquid composition onto the recording medium. 2. The intensity of light at a wavelength of 255 nm of the first exposure light source is 1 mW / cm ² or less, and the intensity of light at a wavelength of 255 nm of the second exposure light source is 10 mW / cm ² or more. Or the inkjet recording method of 2. The intensity of light at a wavelength of 365 nm of the first exposure light source is 10 mW / cm ² or more, and the intensity of light at a wavelength of 365 nm of the second exposure light source is 10 mW / cm ² or more. 3. The ink jet recording method according to any one of 3 above.   The inkjet recording method according to claim 1, wherein the first exposure light source is an LED light source.   The inkjet recording method according to claim 1, wherein the second exposure light source is a metal halide lamp or a mercury lamp.   The colored liquid composition contains a photopolymerization initiator A and a photopolymerization initiator B. When the photopolymerization initiator A is dissolved in an acetonitrile solution at a concentration of 0.1% by weight, 365 nm of the solution. When the photopolymerization initiator B was dissolved in an acetonitrile solution at a concentration of 0.1% by weight with respect to the wavelength of the solution (optical path length: 1 cm) and not more than 0.2, the wavelength of 365 nm of the solution The ink jet recording method according to any one of claims 1 to 6, wherein the absorbance (optical path length: 1 cm) is 0.3 or more.   When at least one of the photopolymerization initiators contained in the colored liquid composition is dissolved in an acetonitrile solution at a concentration of 0.1% by weight, the absorbance of the solution with respect to a wavelength of 255 nm (optical path length: 1 cm) Is an ink jet recording method according to any one of claims 1 to 7.   The inkjet recording method according to claim 1, wherein the polymerizable compound is a radical polymerizable compound.   The inkjet recording method according to claim 1, wherein the colored liquid composition has a surface tension greater than that of the undercoat liquid composition.

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