JP5213346B2 - Ink set for inkjet recording and inkjet recording method - Google Patents

Description

  The present invention relates to an ink set for ink jet recording and an ink jet recording method, and more particularly to an ink set for ink jet recording and a recording method suitable for forming high-quality images 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 inkjet methods, the piezo inkjet method that ejects ink using deformation of piezoelectric elements and the thermal inkjet method that ejects ink droplets using the boiling phenomenon of ink due to thermal energy are high resolution and high-speed printability. It has the characteristic that it is excellent in.
Currently, high speed, high image quality, and fixability to recording media are important issues when ink is ejected onto non-water-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, lines are formed on the recording medium, and images are formed. In particular, the above non-absorbing recording medium is used. When recording, if it takes time to dry the droplets after droplet ejection or penetrate the recording medium, the image tends to bleed, and mixing between adjacent colored droplets on the recording medium Has occurred in practical use, such as preventing the formation of sharp images. When mixing between droplets, adjacent droplets that have been struck are united to cause movement of the droplets, so that they deviate from the landing position, and when drawing thin lines, the line width is uneven. When a colored surface is drawn, color unevenness or the like occurs (hereinafter referred to as “droplet interference”). Further, 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 fixed. 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 high-definition drawing properties, there is a method 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 coloring material is applied. A method (for example, see Patent Document 2) and the like are 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 degree and then UV-irradiation is further performed to perform main curing (see, for example, Patent Document 3).
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 4 and 5) that improves the problem of color ink visibility, bleeding, and differences in images between various recording media. In addition, a technique has been proposed in which a substantially transparent actinic ray curable ink is applied by an inkjet head in place of the radiation curable white ink (see, for example, Patent Documents 6, 7, and 8).

Japanese Unexamined Patent Publication No. 63-60783 JP-A-8-174997 JP 2004-42548 A JP 2003-145745 A JP 2004-42525 A JP 2005-96254 A JP 2006-137185 A JP 2006-137183 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, even the methods described in Patent Documents 6, 7 and 8 still have problems such as non-uniform line width and color unevenness due to mixing between droplets.
When the cationic polymerization ink set described in Patent Document 6 is used, the polymerization reaction proceeds even when a small amount of acid is generated. Therefore, in the ultraviolet curable ink jet printer, the leakage of the ultraviolet light source installed in the printer There is a problem in that ejection failure occurs due to polymerization of ink attached to the nozzle surface by light.
On the other hand, when the radical polymerization type ink set described in Patent Document 6 is used, when an image is formed on a thin recording medium or a flexible recording medium, it is caused by volume shrinkage when the polymerization ink is cured. Occurrence of curling of printed matter sometimes became a problem.
Further, the same applies to the case of using the radiation curable liquid layer or ink set described in Patent Documents 7 and 8, and curling of the printed matter occurred.

  The present invention has been made in view of the above, and an object of the present invention is to provide an ink set for ink jet recording and an ink jet recording method in which curling of printed matter is reduced, and discharge stability and fixing property to a recording medium are excellent. And

The above-described problems of the present invention have been solved by means described in <1> and <6> below. It describes below with <2>-<5> and <7> which are preferable embodiments.
<1> At least a radically polymerizable compound, a radical polymerization initiator, and a coloring liquid containing a colorant; and at least a cationically polymerizable compound and an undercoat liquid containing a cationic polymerization initiator, An ink set for inkjet recording,
<2> The ink set for inkjet recording according to <1>, wherein the cationically polymerizable compound is at least one oxetane ring-containing compound and at least one oxirane ring-containing compound,
<3> The inkjet recording ink according to <1> or <2>, wherein the radical polymerizable compound is at least one selected from the group consisting of a monofunctional (meth) acrylate and a bifunctional (meth) acrylate. set,
<4> The ink set for inkjet recording according to any one of <1> to <3>, wherein the undercoat liquid contains a surfactant.
<5> The inkjet recording ink according to any one of <1> to <4>, wherein γA> γB is satisfied, where γA is a surface tension of the colored liquid and γB is a surface tension of the undercoat liquid. set,
<6> In the ink jet recording method using the ink set for ink jet recording according to any one of the above items <1> to <5>, a step of applying an undercoat liquid onto a recording medium; An inkjet recording method comprising: a step of curing; a step of forming an image by discharging a colored liquid onto the semi-cured undercoat liquid; and a step of completely curing the undercoat liquid and the colored liquid;
<7> In the step of semi-curing the undercoat liquid and / or the step of completely curing the undercoat liquid and the colored liquid, the region for semi-curing the undercoat liquid and / or the undercoat liquid and the colored liquid The inkjet recording method according to the above <6>, wherein the humidity is controlled in a completely cured region.

  According to the present invention, it is possible to provide an ink set for ink jet recording and an ink jet recording method, in which curling of printed matter is reduced, and discharge stability and fixing property to a recording medium are excellent.

Hereinafter, the present invention will be described in detail.
(1) Ink set for ink jet recording The ink set for ink jet recording of the present invention includes a coloring liquid containing at least a radical polymerizable compound, a radical polymerization initiator, and a colorant, at least a cationic polymerizable compound, and cationic polymerization. And an undercoat liquid containing an initiator.
By using this ink set for ink jet recording, ink bleeding is effectively suppressed regardless of which non-absorbable recording medium is used, and line width non-uniformity or color unevenness caused by droplet ejection interference, etc. Can be suppressed, curling of the printed matter can be reduced, and an ink set for ink jet recording excellent in ejection stability can be provided.
In the present invention, the colored liquid and the undercoat liquid are also collectively referred to as “liquid composition”.
The main requirements constituting the ink set for inkjet recording of the present invention will be described in detail below.

(Coloring liquid)
Among the liquid compositions constituting the ink set for inkjet recording of the present invention, the colored liquid is a colored liquid containing at least a radical polymerizable compound, a radical polymerization initiator, and a colorant.
By making the polymerizable compound contained in the color liquid into a radical polymerizable compound, it prevents discharge failure caused by polymerization of ink attached to the nozzle surface due to leakage light from an ultraviolet light source installed in the printer. Is possible. As a result, image quality defects such as streaks due to non-ejection can be prevented even in continuous printing for a long time exceeding 5 hours.

From the viewpoint of image fixability, the radical polymerizable compound is preferably added in an amount of 40% by weight or more and 98% by weight or less, and 50% by weight or more and 95% by weight based on the total weight of the colored liquid. % Or less is more preferable, and 60% by weight or more and 90% by weight or less is particularly preferable. It is preferable for the amount of radically polymerizable compound added to be in the above range since the curability is excellent and the viscosity is appropriate.
The concentration of the radical polymerization initiator added is preferably 0.1% by weight or more and 20.0% by weight or less, and preferably 0.5% by weight or more and 18.0% by weight or less based on the total weight of the colored liquid. More preferably, it is 1.0 wt% or more and 15.0 wt% or less. It is preferable for the amount of radical polymerization initiator added to be in the above-mentioned range since it is excellent in curability and is appropriate from the viewpoint of reducing surface stickiness.
The colorant is added in an amount of 50% by weight or less, more preferably 1% by weight or more and 30% by weight or less, and more preferably 2% by weight or more and 20% by weight or more based on the total weight of the color liquid. It is particularly preferable that the amount is not more than% by weight. It is preferable that the addition amount of the colorant be within the above range since good image density and storage stability can be obtained.
The concentration of the sensitizing dye contained in the coloring liquid is preferably 0.1 to 15.0% by weight, and preferably 0.5 to 10.0% by weight with respect to the total weight of the coloring liquid. Is more preferable, and it is further more preferable that it is 1.0 to 8.0 weight%. It is preferable for the amount added to be in the above range since good curability inside the film can be obtained.

The colored liquid may be a liquid at room temperature, but from the viewpoint of ink jetting suitability, 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, 25 ° C. The viscosity at is 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. of the colored liquid is preferably 18 mN / m or more and 40 mN / m or less, more preferably 20 mN / m or more and 35 mN / m or less, and more preferably 22 mN / m or more and 32 mN / m from the viewpoint of ink jetting appropriateness. 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. Measurement was carried out at a rotation speed of 10 rpm using the first rotor. However, for those having a viscosity higher than 60 mPa · s, the measurement was performed by changing the number of revolutions to 5 rpm, 2.5 rpm, 1 rpm, 0.5 rpm, or the like as necessary.
Here, the surface tension is 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.). It is a measured value.

(Undercoat liquid)
Among the liquid compositions constituting the ink set for inkjet recording of the present invention, the undercoat liquid contains at least a cationic polymerizable compound and a cationic polymerization initiator.
By making the polymerizable compound contained in the undercoat liquid into a cationic polymerizable compound, volume shrinkage during curing of the polymerization ink that occurs when an image is formed on a thin recording medium or a flexible recording medium It is possible to prevent the curling of the printed matter due to.

From the viewpoint of image fixability, the cationic polymerizable compound is preferably added in an amount of 40 wt.% Or more and 98 wt.% Or less, and 50 wt.% Or more and 95 wt. % Or less is more preferable, and 60% by weight or more and 90% by weight or less is particularly preferable. It is preferable for the addition amount of the cationic polymerizable compound to be in the above range since the curability is excellent and the viscosity is appropriate.
The addition concentration of the cationic polymerization initiator is preferably 0.1% by weight or more and 20.0% by weight or less, and preferably 0.5% by weight or more and 18.0% by weight or less with respect to the total weight of the undercoat liquid. More preferably, it is 1.0 wt% or more and 15.0 wt% or less. It is preferable that the addition amount of the photopolymerization initiator is within the above range because it is excellent in curability and is appropriate from the viewpoint of reducing surface stickiness.
The addition concentration of the sensitizing dye contained in the undercoat liquid is preferably 0.1 to 15.0% by weight, more preferably 0.5 to 10.0 based on the total weight of the undercoat liquid. % By weight, more preferably 1.0 to 8.0% by weight. It is preferable for the amount added to be in the above range since good curability inside the film can be obtained.

From the viewpoint of uniformly coating the recording medium, the viscosity of the undercoat liquid at 25 ° C. is preferably 1,000 mPa · s or less, or the viscosity at 60 ° C. is 300 mPa · s or less, and the viscosity at 25 ° C. is 600 mPa · s. The viscosity at s or less or 60 ° C. is more preferably 200 mPa · s or less, and the viscosity at 25 ° C. is particularly preferably 400 mPa · s or less or the viscosity at 60 ° C. is 150 mPa · s or less.
Similarly, from the viewpoint of uniformly coating the recording medium, the surface tension of the undercoat liquid at 25 ° C. is preferably 16 mN / m or more and 38 mN / m or less, more preferably 18 mN / m or more and 33 mN / m or less, and 20 mN / m. More preferably, it is 30 mN / m or less.
Further, from the viewpoint of enhancing the color reproducibility of the image, the undercoat liquid preferably contains substantially no colorant or preferably contains a white pigment. The “substantially free of colorant” does not exclude the use of a trace amount of blue pigment for correcting the yellowing of the recording medium or the inclusion of a trace amount that is not visible. Absent. The allowable amount is preferably 1% by weight or less, particularly preferably not contained, based on the total weight of the undercoat liquid. Moreover, the white pigment which can be preferably used is described in the item of (colorant).

  Hereinafter, various components used in the coloring liquid and the undercoat liquid will be described.

<Polymerizable compound and polymerization initiator>
The polymerizable compound (radical polymerizable compound and cationic polymerizable compound) and the polymerization initiator (radical polymerization initiator and cationic polymerization initiator) in the present invention will be described in detail.

-Radically polymerizable compounds-
The radical polymerizable compound in the present invention is not particularly limited as long as it is a compound that causes radical polymerization reaction by some energy application and cures, and can be used regardless of the type of monomer, oligomer, or polymer. Various known radically polymerizable monomers known as photoradical polymerizable monomers that cause a polymerization reaction with an initiation species generated from a radical polymerization initiator described later can be used. Moreover, the radically polymerizable compound may be a monofunctional compound or a polyfunctional compound.

  Examples of the radical polymerizable compound include (meth) acrylates, (meth) acrylamides, aromatic vinyls and the like. In the present specification, when referring to both or one of “acrylate” and “methacrylate”, when referring to both “(meth) acrylate” and “acryl” and / or “methacryl”, “(meth) acryl” And may be described respectively.

  The radical polymerizable compound in the present invention is preferably (meth) acrylates from the viewpoint of curability and viscosity. In particular, it is more preferable that it is at least one selected from monofunctional (meth) acrylate and bifunctional (meth) acrylate from the viewpoint of viscosity.

Hereinafter, the radically polymerizable compound applicable to the present invention will be described in detail.
Examples of the (meth) acrylate used in the present invention include the following.
As monofunctional (meth) acrylate, hexyl group (meth) acrylate, 2-ethylhexyl (meth) acrylate, tert-octyl (meth) acrylate, isoamyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, Stearyl (meth) acrylate, isostearyl (meth) acrylate, cyclohexyl (meth) acrylate, 4-n-butylcyclohexyl (meth) acrylate, bornyl (meth) acrylate, isobornyl (meth) acrylate, benzyl (meth) acrylate, 2- Ethihexyl diglycol (meth) acrylate, butoxyethyl (meth) acrylate, 2-chloroethyl (meth) acrylate, 4-bromobutyl (meth) acrylate, cyanoethyl (meth) ) Acrylate, benzyl (meth) acrylate, butoxymethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, alkoxymethyl (meth) acrylate, alkoxyethyl (meth) acrylate, 2- (2-methoxyethoxy) ethyl (meth) Acrylate, 2- (2-butoxyethoxy) ethyl (meth) acrylate, 2,2,2-tetrafluoroethyl (meth) acrylate, 1H, 1H, 2H, 2H-perfluorodecyl (meth) acrylate, 4-butylphenyl (Meth) acrylate, phenyl (meth) acrylate, 2,4,5-tetramethylphenyl (meth) acrylate, 4-chlorophenyl (meth) acrylate, phenoxymethyl (meth) acrylate, phenoxyethyl (meth) acrylate , Glycidyl (meth) acrylate, glycidyloxybutyl (meth) acrylate, glycidyloxyethyl (meth) acrylate, glycidyloxypropyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, hydroxyalkyl (meth) acrylate, 2 -Hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate,

  2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate , Dimethylaminopropyl (meth) acrylate, diethylaminopropyl (meth) acrylate, trimethoxysilylpropyl (meth) acrylate, trimethylsilylpropyl (meth) acrylate, polyethylene oxide monomethyl ether (meth) acrylate, oligoethylene oxide monomethyl ether (meth) acrylate, Polyethylene oxide (meth) acrylate, oligoethylene oxide (meth) acrylate, oligoethyleneoxy Monoalkyl ether (meth) acrylate, polyethylene oxide monoalkyl ether (meth) acrylate, dipropylene glycol (meth) acrylate, polypropylene oxide monoalkyl ether (meth) acrylate, oligopropylene oxide monoalkyl ether (meth) acrylate, 2-methacrylate Leuoxytyl succinic acid, 2-methacryloyloxyhexahydrophthalic acid, 2-methacryloyloxyethyl-2-hydroxypropyl phthalate, butoxydiethylene glycol (meth) acrylate, trifluoroethyl (meth) acrylate, perfluorooctylethyl ( (Meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, ethylene oxide (EO) modified phenol (meth) ) Acrylate, EO-modified cresol (meth) acrylate, EO-modified nonylphenol (meth) acrylate, propylene oxide (PO) modified nonylphenol (meth) acrylate, EO-modified 2-ethylhexyl (meth) acrylate.

  Specific examples of the bifunctional (meth) acrylate include 1,6-hexanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and 2,4-dimethyl. -1,5-pentanediol di (meth) acrylate, butylethylpropanediol (meth) acrylate, ethoxylated cyclohexanemethanol di (meth) acrylate, polyethylene glycol di (meth) acrylate, oligoethylene glycol di (meth) acrylate, Ethylene glycol di (meth) acrylate, 2-ethyl-2-butyl-butanediol di (meth) acrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, EO-modified bisphenol A di (meth) acrylate Bisphenol F polyethoxydi (meth) acrylate, polypropylene glycol di (meth) acrylate, oligopropylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 2-ethyl-2-butylpropanediol di ( Examples include meth) acrylate, 1,9-nonanedi (meth) acrylate, propoxylated ethoxylated bisphenol A di (meth) acrylate, and tricyclodecane di (meth) acrylate.

Specific examples of trifunctional (meth) acrylates include trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, trimethylolpropane alkylene oxide-modified tri (meth) acrylate, pentaerythritol tri (meth) acrylate , Dipentaerythritol tri (meth) acrylate, trimethylolpropane tri ((meth) acryloyloxypropyl) ether, isocyanuric acid alkylene oxide modified tri (meth) acrylate, propionate dipentaerythritol tri (meth) acrylate, tri ((meta ) Acryloyloxyethyl) isocyanurate, hydroxypivalaldehyde-modified dimethylolpropane tri (meth) acrylate, sorbitol tri (meth) acrylate Rate, propoxylated trimethylolpropane tri (meth) acrylate, and ethoxylated glycerin triacrylate.
Specific examples of tetrafunctional (meth) acrylates include pentaerythritol tetra (meth) acrylate, sorbitol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, propionate dipentaerythritol tetra (meth) acrylate, ethoxylated penta Examples include erythritol tetra (meth) acrylate.
Specific examples of the pentafunctional (meth) acrylate include sorbitol penta (meth) acrylate and dipentaerythritol penta (meth) acrylate.
Specific examples of hexafunctional (meth) acrylate include dipentaerythritol hexa (meth) acrylate, sorbitol hexa (meth) acrylate, phosphazene alkylene oxide modified hexa (meth) acrylate, captolactone modified dipentaerythritol hexa (meth) acrylate Etc.

  Examples of (meth) acrylamides used in the present invention include (meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-propyl (meth) acrylamide, Nn-butyl ( (Meth) acrylamide, Nt-butyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-methylol (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N , N-diethyl (meth) acrylamide, (meth) acryloylmorpholine.

  Specific examples of aromatic vinyls used in the present invention include styrene, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, isopropylstyrene, chloromethylstyrene, methoxystyrene, acetoxystyrene, chlorostyrene, dichlorostyrene, bromo Styrene, vinyl benzoic acid methyl ester, 3-methylstyrene, 4-methylstyrene, 3-ethylstyrene, 4-ethylstyrene, 3-propylstyrene, 4-propylstyrene, 3-butylstyrene, 4-butylstyrene, 3- Hexyl styrene, 4-hexyl styrene, 3-octyl styrene, 4-octyl styrene, 3- (2-ethylhexyl) styrene, 4- (2-ethylhexyl) styrene, allyl styrene, isopropenyl styrene, butenyls Ren, octenyl styrene, 4-t-butoxycarbonyl styrene, 4-methoxystyrene, and a 4-t-butoxystyrene.

  Furthermore, as the radical polymerizable monomer in the present invention, vinyl esters [vinyl acetate, vinyl propionate, vinyl versatate, etc.], allyl esters [eg, allyl acetate], halogen-containing monomers [vinylidene chloride, vinyl chloride, etc.], Vinyl ether [methyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, methoxy vinyl ether, 2-ethylhexyl vinyl ether, methoxyethyl vinyl ether, cyclohexyl vinyl ether, chloroethyl vinyl ether, etc.], vinyl cyanide [(meth) acrylonitrile, etc.], olefins [ethylene, propylene, etc. ] Etc. are mentioned.

  The content of the radical polymerizable compound is preferably 50 to 95% by weight, more preferably 60 to 92% by weight, still more preferably 70%, based on the total solid content of the liquid containing the radical polymerizable compound. It is in the range of ~ 90% by weight.

-Cationically polymerizable compound-
The cationically polymerizable compound in the present invention is not particularly limited as long as it is a compound that generates and cures a cationic polymerization reaction by applying some energy, and can be used regardless of the type of monomer, oligomer, or polymer. Various known cationically polymerizable monomers known as photocationically polymerizable monomers that cause a polymerization reaction by an initiation species generated from a cationic polymerization initiator described later can be used. The cationic polymerizable compound may be a monofunctional compound or a polyfunctional compound.

  As the cationically polymerizable compound in the present invention, an oxetane ring-containing compound and an oxirane ring-containing compound are preferable from the viewpoint of curability and scratch resistance, and an embodiment containing both the oxetane ring-containing compound and the oxirane ring-containing compound is preferable. More preferred.

  Here, in this specification, an oxirane ring-containing compound (hereinafter sometimes referred to as “oxirane compound” as appropriate) is a compound containing at least one oxirane ring (oxiranyl group, epoxy group) in the molecule. Specifically, it can be appropriately selected from those usually used as an epoxy resin, and examples thereof include conventionally known aromatic epoxy resins, alicyclic epoxy resins, and aliphatic epoxy resins. Any of a monomer, an oligomer, and a polymer may be sufficient. An oxetane ring-containing compound (hereinafter sometimes referred to as “oxetane compound” as appropriate) is a compound containing at least one oxetane ring (oxetanyl group) in the molecule.

Hereinafter, the cationically polymerizable compound applicable to the present invention will be described in detail.
Examples of the cationic polymerizable monomer include JP-A-6-9714, JP-A-2001-31892, JP-A-2001-4006, JP-A-2001-55507, JP-A-2001-310938, JP-A-2001-310937, and 2001. Epoxy compounds, vinyl ether compounds, oxetane compounds and the like described in each publication such as No. 220526.

  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 include, for example, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, brominated bisphenol A diglycidyl ether, brominated bisphenol F diglycidyl ether, and 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′-epoxycyclohexanecarboxy 2- (3,4-epoxycyclohexyl) -7,8-epoxy-1,3-dioxaspiro [5.5] undecane, bis (3,4-epoxycyclohexyl) Rumethyl) adipate, vinylcyclohexene oxide, 4-vinylepoxycyclohexane, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 3,4-epoxy-6-methylcyclohexyl-3 ′, 4′-epoxy-6 '-Methylcyclohexanecarboxylate, methylenebis (3,4-epoxycyclohexane), dicyclopentadiene diepoxide, ethylene glycol di (3,4-epoxycyclohexylmethyl) ether, ethylenebis (3,4-epoxycyclohexanecarboxylate) , Epoxyhexahydrophthalate dioctyl, epoxyhexahydrophthalate di-2-ethylhexyl, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, Resin 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-diepoxycyclooctane and the like.
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, Cyclohexylmethyl 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, ethoxyethoxyethyl vinyl ether Methoxypolyethylene Coal 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, Examples include chloroethoxyethyl vinyl ether, phenylethyl vinyl ether, phenoxypolyethylene glycol vinyl ether, and the like.

Examples of the polyfunctional vinyl ether 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, bisphenol A alkylene oxide divinyl ether, and bisphenol F. Divinyl ethers such as alkylene oxide divinyl ether; trimethylolethane trivinyl ether, trimethylolpropane trivinyl ether, ditrimethylolpropane 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, propylene oxide addition Examples thereof include polyfunctional vinyl ethers such as 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, surface hardness of the formed image, and the like, and a divinyl ether compound is particularly preferable.

  As the oxetane compound in the present invention, a known oxetane compound as described in JP-A Nos. 2001-220526, 2001-310937, and 2003-341217 can be arbitrarily selected and used.

  The oxetane compound that can be used in the present invention is preferably a compound having 1 to 4 oxetane rings in its structure. By using such a compound, it becomes easy to maintain the viscosity of the liquid for ink-jet recording in a good handling range, and it is possible to obtain high adhesion of the cured ink to the recording medium. it can.

  Examples of monofunctional oxetane compounds 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- Til-3-oxetanylmethyl) ether, ethyl diethylene 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-oxe) Nylmethyl) 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 oxetane compounds include, for example, 3,7-bis (3-oxetanyl) -5-oxa-nonane, 3,3 ′-(1,3- (2-methylenyl) propanediylbis (oxymethylene) ) Bis- (3-ethyloxetane), 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, 1,2-bis [(3-ethyl-3-oxetanylmethoxy) methyl] ethane, 1,3-bis [(3-ethyl-3-oxetanylmethoxy) methyl] propane, ethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, dicyclopentenylbis (3-ethyl-3-oxetanylmethyl) ether , Triethylene glycol 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 pentakis (3- Til-3-oxetanylmethyl) ether, dipentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether, caprolactone-modified dipentaerythritol hexakis (3-ethyl-3-oxetanylmethyl) ether, caprolactone-modified dipentaerythritol pentane Kiss (3-ethyl-3-oxetanylmethyl) ether, ditrimethylolpropane tetrakis (3-ethyl-3-oxetanylmethyl) ether, ethylene oxide (EO) modified bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, Propylene oxide (PO) modified bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, EO modified hydrogenated bisphenol A bis (3-ethyl-3-oxetanylmethyl) Examples thereof include polyfunctional oxetanes such as ether, PO-modified hydrogenated bisphenol A bis (3-ethyl-3-oxetanylmethyl) ether, and EO-modified bisphenol F (3-ethyl-3-oxetanylmethyl) ether.

Such oxetane compounds are described in detail in the above-mentioned JP-A No. 2003-341217, paragraphs [0021] to [0084], and the compounds described herein can be suitably used in the present invention.
Among the oxetane compounds used in the present invention, it is preferable to use a compound having 1 to 2 oxetane rings from the viewpoint of the viscosity and tackiness of the ink jet recording liquid.

In the present invention, these cationically polymerizable compounds may be used alone or in combination of two or more.
The content of the cationic polymerizable compound is preferably 50 to 95% by weight, more preferably 60 to 92% by weight, and still more preferably 70 to 90% by weight, based on the total solid content of the liquid containing the cationic polymerizable compound. Range.

-Radical polymerization initiator, cationic polymerization initiator-
In the ink set of the present invention, a radical polymerization initiator is contained in the liquid containing the radical polymerizable compound, and a cationic polymerizable initiator is contained in the liquid containing the cationic polymerizable compound. The radical polymerization initiator or cationic polymerization initiator in the present invention is particularly preferably a photopolymerization initiator.

  The radical polymerization initiator or cationic polymerization initiator in the present invention is a compound that generates a radical, acid, or base by causing a chemical change through the action of light or interaction with the electronically excited state of a sensitizing dye. Among them, the photo radical generator or the photo acid generator is preferable from the viewpoint that polymerization can be initiated by a simple means of exposure.

  In the present invention, a radical polymerization initiator or a cationic polymerization initiator is appropriately selected from the polymerization initiators described in detail below in consideration of the relationship with the radical polymerization initiator or cationic polymerization initiator used in combination. Can be used.

  As the photopolymerization initiator, actinic rays to be irradiated, for example, 400 to 200 nm ultraviolet rays, far ultraviolet rays, g rays, h rays, i rays, KrF excimer laser rays, ArF excimer laser rays, electron beams, X rays, molecules Those having sensitivity to a line or an ion beam can be appropriately selected and used.

  As the specific photopolymerization initiator, those 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. There are many chemical amplification type photoresists and compounds used for photocationic polymerization described in (Organic Electronics Materials Research Group, “Organic Materials for Imaging”, Bunshin Publishing (1993), pages 187-192). Has been. 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 salts, (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) As aromatic onium salts, elements of Group V, VI and VII 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, 4760013, 4,734,444, and 2,833,827. (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) The 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′-tetra Peroxyesters such as 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 ′ -Tetra Enylbiimidazole, 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 compound which is another example of the photopolymerization initiator in the present invention include U.S. Pat. Nos. 3,567,453 and 4,343,891, European Patents 109,772 and 109,773. The compounds described in No. are listed.
Examples of the photopolymerization initiator (g) azinium compounds include JP-A 63-138345, JP-A 63-142345, JP-A 63-142346, JP-A 63-143537. And compounds having an N—O bond described in JP-B-46-42363.

Examples of (h) metallocene compounds which are other examples of photopolymerization initiators include JP 59-152396, JP 61-151197, JP 63-41484, and JP 2-249. And titanocene compounds described in JP-A-2-4705 and iron-arene complexes described in JP-A-1-304453 and JP-A-1-152109.
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 active ester compounds include European Patent Nos. 0290750, 046083, 156153, 271851 and 0388343, U.S. Pat. Nos. 3,901,710 and 4,181,531, Nitrobenzol ester compounds described in JP-A-60-198538 and JP-A-53-133022, European Patents 0199672, 84515, 199672, 0441115, and 0101122 U.S. Pat. Nos. 4,618,564, 4,371,605 and 4,431,774, JP-A 64-18143, JP-A-2-245756, and JP-A-4-365048, respectively. 62-6223, Shoko 63-14340 And compounds, and the like described in the JP-A-59-174831.

  (J) Preferred examples of the compound having a carbon halogen bond include those described in 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 compound group described in German Patent No. 3021590, or a compound group described in German Patent No. 3021599, etc. Can be mentioned.

  Preferable specific examples of the compounds represented by the above (a) to (j) include those shown below. In the specific examples below, Ph represents a phenyl group, and Ar represents an arbitrary aryl group.

  As the radical polymerization initiator in the present invention, from the viewpoint of curability, among the above, aromatic ketones are preferable, compounds having a benzophenone skeleton or a thioxanthone skeleton are more preferable, α-aminobenzophenone compounds, and acylphosphine sulfide compounds. Particularly preferred.

As the cationic polymerization initiator in the present invention, from the viewpoint of curability, among the above, aromatic onium salts are preferable, iodonium salts, more preferably a sulfonium salt, PF ₆ salts of iodonium, PF ₆ salts of sulfonium salts are particularly preferable.

  A radical polymerization initiator or a cationic polymerization initiator can be used individually by 1 type or in combination of 2 or more types. Further, as long as the effects of the present invention are not impaired, a known sensitizer can be used in combination for the purpose of improving sensitivity.

The content of the radical polymerization initiator or the cationic polymerization initiator is preferably 0.1 to 20% by weight, more preferably 0.5 to 10% by weight, based on the total solid content of each liquid containing the polymerization initiator. 1 to 7% by weight is more preferable.
In addition, the content ratio (weight ratio) between the radical polymerization initiator or the cationic polymerization initiator and the polymerizable compound used in combination therewith is, respectively, radical polymerization initiator: radical polymerizable compound or cationic polymerization initiator: cation. It is preferable that it is polymeric compound = 0.5: 100-30: 100, It is more preferable that it is 1: 100-15: 100, It is further more preferable that it is 2: 100-10: 100.

(Coloring agent)
In the present invention, the coloring liquid contains at least a coloring agent. On the other hand, the undercoat liquid may contain a colorant, but preferably contains substantially no colorant or contains a white pigment.
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 these, the colorant contained in the coloring liquid 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, “Dictionary of Pigments” edited by Seijiro Ito (2000), W. Herbst, K. Hunger, Industrial Organic Pigments, JP 2002-12607 A, JP 2002-188025 A, Examples thereof include pigments described in JP2003-26978A and JP2003-342503A.

  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. Pigment yellow 180, C.I. I. Non-benzidine type azo pigments such as C.I. Pigment Yellow 200 (Novoperm Yellow 2HG); 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, CINQUASIA Magenta RT-355T; manufactured by Ciba Specialty Chemicals), 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. Pigment blue 15, C.I. I. Phthalocyanine pigments such as CI Pigment Blue 15: 3 (IRGALITE BLE GLO; manufactured by Ciba Specialty Chemicals) (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. Examples of the carbon black include SPECIAL BLACK 250 (manufactured by Degussa).
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. 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.

Dispersing colorants, for example, bead mill, ball mill, sand mill, attritor, roll mill, jet mill, homogenizer, paint shaker, kneader, agitator, Henschel mixer, colloid mill, ultrasonic homogenizer, pearl mill, wet jet mill, etc. Can be used.
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 dispersion aid is preferably added in an amount of 1 to 50 parts by weight with respect to 100 parts by weight of the colorant.

  As a dispersion medium for various components such as a colorant in the coloring liquid, a solvent may be added, or the polymerizable compound which is a low molecular weight component without solvent may be used as the dispersion medium. Is preferably an active energy ray-curable liquid, and is preferably solvent-free in order to cure after applying the coloring liquid onto the recording medium. This is because if the solvent remains in the image formed from the cured coloring liquid, 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 size of the colorant used here is preferably from 0.01 μm to 0.4 μm, and more preferably from 0.02 μm to 0.2 μm, since the finer the particle, the better the color developability. It is preferable to set the colorant, dispersant, dispersion medium, dispersion conditions, and filtration conditions so that the maximum particle diameter 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 coloring liquid, the transparency of the coloring liquid, 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 coloring liquid can be measured by a known measuring 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.

<Relationship between surface tension of coloring liquid and undercoat liquid>
From the viewpoint of preventing bleeding of the formed image for a long time until the coloring liquid applied on the non-recording medium is started, the surface tension of the coloring liquid is γA and the surface tension of the undercoat liquid is γB. The relationship between γA and γB preferably satisfies γA> γB, more preferably satisfies γA−γB ≧ 1, and particularly preferably satisfies γA−γB ≧ 2.
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.). is there.

<Sensitizer>
A sensitizer may be added to the colored liquid and the undercoat liquid in the present invention in order to absorb specific actinic radiation and promote decomposition of the polymerization initiator. The sensitizer absorbs specific actinic radiation and enters an electronically excited state. The sensitizer in an electronically excited state comes into contact with the polymerization initiator, and effects such as electron transfer, energy transfer, and heat generation occur. As a result, the polymerization initiator undergoes a chemical change and decomposes to generate radicals, acids or bases.
As a sensitizer that can be used in the present invention, a sensitizing dye is preferable.
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.
Polynuclear aromatics (eg, pyrene, perylene, triphenylene), xanthenes (eg, fluorescein, eosin, erythrosine, rhodamine B, rose bengal), cyanines (eg, thiacarbocyanine, oxacarbocyanine), merocyanines ( For example, merocyanine, carbomerocyanine), thiazines (for example, thionine, methylene blue, toluidine blue), acridines (for example, acridine orange, chloroflavin, acriflavine), anthraquinones (for example, anthraquinone), squalium (for example, squalium) ), Coumarins (eg 7-diethylamino-4-methylcoumarin).

  More preferable examples of the sensitizing dye include compounds represented by the following formulas (IX) to (XIII).

In the formula (IX), A ¹ represents a sulfur atom or NR ⁵⁰ , R ⁵⁰ represents an alkyl group or an aryl group, and L ² forms a basic nucleus of the dye together with the adjacent A ¹ and the adjacent carbon atom. R ⁵¹ and R ⁵² each independently represent a hydrogen atom or a monovalent nonmetallic atomic group, and R ⁵¹ and R ⁵² may be bonded to each other to form an acidic nucleus of the dye. Good. W represents an oxygen atom or a sulfur atom.

In formula (X), Ar ¹ and Ar ² each independently represent an aryl group and are linked via a bond with —L ³ —. Here, L ³ represents —O— or —S—. W is synonymous with that shown in Formula (IX).

In the formula (XI), A ₂ represents a sulfur atom or NR ⁵⁹ , L ⁴ represents a nonmetallic atomic group that forms a basic nucleus of the dye together with adjacent A ₂ and a carbon atom, R ⁵³ , R ⁵⁴ , R ⁵⁵ , R ⁵⁶ , R ⁵⁷ and R ⁵⁸ each independently represents a monovalent non-metallic atomic group, and R ⁵⁹ represents an alkyl group or an aryl group.

In formula (XII), A ³ and A ⁴ each independently represent —S—, —NR ⁶² — or —NR ⁶³ —, wherein R ⁶² and R ⁶³ each independently represent a substituted or unsubstituted alkyl group, substituted or represents an unsubstituted aryl group, L to ^5, L ⁶ are each independently, together with the adjacent a ^3, a ⁴ and adjacent carbon atoms represents a nonmetallic atom group necessary for forming a basic nucleus of a dye, R ⁶⁰ , R ⁶¹ each independently represents a hydrogen atom or a monovalent non-metallic atomic group, or may be bonded to each other to form an aliphatic or aromatic ring.

In the formula (XIII), R ⁶⁶ represents an aromatic ring or a hetero ring which may have a substituent, and A ⁵ represents an oxygen atom, a sulfur atom or ═NR ⁶⁷ . R ⁶⁴ , R ⁶⁵ and R ⁶⁷ each independently represent a hydrogen atom or a monovalent nonmetallic atomic group, and R ⁶⁷ and R ⁶⁴ , and R ⁶⁵ and R ⁶⁷ each represent an aliphatic or aromatic ring. Can be combined to form.

  Preferable specific examples of the compounds represented by formulas (IX) to (XIII) include (E-1) to (E-20) shown below. In the following specific examples, Ph represents a phenyl group, and Me represents a methyl group.

When a sensitizer is used in the color liquid, the concentration of the sensitizer is 0.1 to 15.0% by weight (“0.1% by weight or more and 15.0% by weight) with respect to the total weight of the color liquid. It is preferable that it is 0.5 to 10.0% by weight, more preferably 1.0 to 8.0% by weight. Further preferred. When the addition amount is within the above range, good curability inside the film can be obtained.
When a sensitizer is used in the undercoat liquid, the addition concentration of the sensitizer is preferably 0.1 to 15.0% by weight, more preferably 0.8%, based on the total weight of the undercoat liquid. It is 5 to 10.0% by weight, more preferably 1.0 to 8.0% by weight. When the addition amount is within the above range, good curability inside the film can be obtained.

<Surfactant>
The coloring liquid and the undercoat liquid preferably contain a surfactant, and examples of the surfactant used in the present invention include the following surfactants. 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 as 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). No. (columns 8 to 17) and those described in JP-A Nos. 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.

<Other additives>
In the coloring liquid and undercoat liquid in the present invention, in addition to the polymerizable compound and the polymerization initiator, various additives can be used in combination according to the purpose. For example, an ultraviolet absorber can be used from the viewpoint of improving the weather resistance of the obtained fine pattern molded product. Further, an antioxidant can be added to improve the stability of the coloring liquid and the undercoat liquid.
Further, 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 ejection properties, ink compositions and substrates In order to improve the adhesiveness, an extremely small amount of organic solvent can be added.
Moreover, various polymer compounds can be added to adjust film physical properties. High molecular compounds include acrylic polymer, polyvinyl butyral resin, polyurethane resin, polyamide resin, polyester resin, epoxy resin, phenol resin, polycarbonate resin, polyvinyl butyral resin, polyvinyl formal resin, shellac, vinyl resin, acrylic resin. 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.

(2) Inkjet recording method In the inkjet recording method of the present invention, an ink set for inkjet recording composed of a colored liquid for forming an image and an undercoat liquid used as an undercoat liquid is used.
The recording method includes (i) a step of applying an undercoat liquid onto a recording medium, (ii) a step of semi-curing the undercoat liquid, and (iii) discharging a colored liquid onto the semi-cured undercoat liquid. Image forming, and at least three processes.
Further, from the viewpoint of improving the abrasion resistance and adhesion of the image, it is preferable to include (iv) a step of completely curing the image after the above three steps.
Moreover, it is preferable that the colored liquid in the present invention uses a plurality of colored liquids as a multicolor ink set. Thus, when using a multicolor ink set, it is more preferable that the inkjet recording method of the present invention includes a step of semi-curing the applied color liquid after the color liquid is applied to the recording medium. It is particularly preferable to include a second-half curing step applied to each of the liquids. For example, when forming a secondary color using the coloring liquid A and the coloring liquid B having different hues, a step of semi-curing the coloring liquid A is performed, and then the colored liquid A is semi-cured. A step of discharging the liquid B is preferably performed.

Further, from the viewpoint of controlling the cured state of the image, in the step of semi-curing the undercoat liquid and / or the step of completely curing the image, the humidity of the region where the undercoat liquid is semi-cured and / or the region where the image is completely cured. It is preferable to control this.
From the viewpoint of obtaining a preferable semi-cured state, the preferable humidity in the region where the undercoat liquid is semi-cured is preferably 40% or more and 80% or less, and the relative humidity in the air is 50% or more and 70%. It is more preferable that the relative humidity in air is 55% or more and 65% or less. A preferable semi-cured state will be described later.
From the viewpoint of improving the curability of the image, it is preferable that the relative humidity in the region where the image is completely cured is 50% or less, and the relative humidity in the air is 40% or less. More preferably, the relative humidity in the air is particularly preferably 30% or less.
The means for controlling the humidity is not particularly limited, and a commercially available humidifier or dehumidifier can be used. From the viewpoint of space saving of the apparatus and ease of control, it is preferable to use a commercially available air conditioning unit. Examples of commercially available air conditioning units include the precision air conditioning unit (temperature / humidity control unit) manufactured by Apiste PAU series (PAU-300S-HC, PAU-A920S-HC, PAU-A1400S-HC, PAU-A2600S-HC, PAU-A3500S-HC).

Therefore, the most preferable step of the ink jet recording method of the present invention is as shown in FIG.
FIG. 1 shows a conceptual diagram of an ink jet recording method that can be suitably used in the present invention. This will be described in detail below with reference to FIG.
The recording medium 6 is conveyed by recording medium conveying means 7A and 7B, and is conveyed from left to right in FIG.
The recording medium and the recording medium conveying means are not particularly limited, but in the present embodiment shown in FIG. 1, a plastic film is used as the recording medium, and the film unwinding as the recording medium conveying means. Machine (7A) and film winder (7B) are used.
In the first step, the undercoat liquid is applied onto the recording medium 6 by means 1 for applying the undercoat liquid. Examples of means for applying the undercoat liquid include a roll coater.
Subsequently, in the second step, the undercoat liquid applied on the recording medium 6 is semi-cured by means 2 for semi-curing the undercoat liquid. An example of means for semi-curing the undercoat liquid is an ultraviolet light source. Here, the relative humidity in the air in the semi-cured region is adjusted to 55% or more and 65% or less by the precision air conditioning unit.
In the third step, a colored image is formed by means 3Y for applying a colored liquid onto the film of the undercoat liquid semi-cured on the recording medium 6. In FIG. 1, a yellow coloring liquid is applied to form a yellow image. As the means 3Y for applying the yellow coloring liquid, a yellow ink jet recording head can be exemplified. In the fourth step, the yellow colored liquid is semi-cured by means 4Y for semi-curing the colored liquid applied in the third step. In FIG. 1, an ultraviolet light source is used as a means for semi-curing the colored liquid, and the yellow colored liquid applied on the film of the undercoat liquid is semi-cured.
In the fifth step, the cyan color liquid is applied by means 3C for applying the cyan color liquid onto the undercoat liquid and / or the yellow liquid film semi-cured on the recording medium to form a cyan image. Examples of the means 3C for applying the cyan coloring liquid include a cyan ink jet recording head. In the sixth step, the colored liquid applied in the fifth step is semi-cured. In FIG. 1, an ultraviolet light source is used as means 4C for semi-curing the cyan coloring composition, and the cyan coloring liquid applied on the undercoat liquid and / or the yellow coloring composition film is semi-cured.
Similarly, in the seventh step, after forming a magenta image on any of the undercoat liquid, yellow color liquid, and cyan color liquid by means 3M for applying a magenta color liquid, magenta coloration is performed in the eighth step. The applied magenta coloring liquid is semi-cured by means 4M for semi-curing the liquid.
Further, in the ninth step, a black image is formed by means 3K for applying a black color liquid onto any one of the undercoat liquid, the yellow color liquid, the cyan color liquid, and the magenta color liquid. In the tenth step, the black colored liquid is semi-cured by means 4K for semi-curing the black colored liquid.
Subsequently, in the eleventh step, the formed full-color image is completely cured by means 5 for completely curing the formed full-color image. Here, the relative humidity in the air in the region where the image is completely cured is adjusted to 30% or less by the precision air conditioning unit.
Here, the tenth step can be omitted, and in this case, the recording medium to which the last colored liquid is applied is completely cured without going through a semi-curing step.
Moreover, 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.

<Step of applying undercoat liquid on recording medium>
In the step of applying the undercoat liquid on the recording medium, the undercoat liquid is applied to the same area as the image formed by discharging colored liquid droplets on the recording medium or an area wider than the image. Is preferred.
Further, the application amount of the undercoat liquid (weight ratio per unit area) is preferably in the range of 0.05 to 5 when the maximum application amount of the coloring liquid (per color) is 1. The range of 0.07 to 4 is more preferable, and the range of 0.1 to 3 is particularly preferable.

In the inkjet recording method of the present invention, a coating device, an inkjet nozzle, or the like can be used as means for applying the undercoat liquid onto 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, extrusion coater and the like. For details, see Yuji Harasaki's “Coating Engineering”.
Among them, from the viewpoint of apparatus cost, the application of the undercoat liquid onto the recording medium is preferably performed by coating using a relatively inexpensive bar coater or spin coater, or by the ink jet method.

<The process of providing a coloring liquid on a recording medium>
In the present invention, the colored liquid that is discharged onto the semi-cured undercoat liquid and / or colored liquid film on the recording medium 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). When the droplet size is within the above range, it is effective in that an image with high sharpness can be drawn at a high density. More preferably, it is 0.5 pL or more and 50 pL or less.
Further, the maximum amount of the coloring liquid applied on the recording medium can be arbitrarily selected depending on the concentration of the colorant contained in the coloring liquid, but from the viewpoint of color reproducibility, curability, and image surface smoothness. from preferably 0.01 g / cm ² or more 0.200 g / cm ² or less, 0.02 g / cm ² or more 0.150 g / cm ² or less are preferred, 0.03 g / cm ² or more 0.100 g / cm ² or less Is particularly preferred.
Note that “on the recording medium” may be an upper part of the recording medium, and is not necessarily in contact with the recording medium.
After applying the undercoat liquid, the droplet ejection interval until the colored droplets are ejected is preferably within a range of 5 μs or more and 10 seconds or less. It is effective in that the effect of the present invention can be remarkably exhibited when the droplet ejection interval is within the above range. The droplet ejection interval of the colored droplets is more preferably 10 μs to 5 seconds, and particularly preferably 20 μs to 5 seconds.

  As means for applying the coloring liquid, it is preferable to use an ink jet head. 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 vibration pressure of a piezo element, an electric signal is converted into an acoustic beam, and ink is used. A head of an acoustic ink jet method in which ink is ejected by using radiation pressure by irradiating the ink, or a thermal ink jet (bubble jet (registered trademark)) method in which ink is heated to form bubbles and the generated pressure is used is suitable. It is.

<Process for semi-curing undercoat liquid and process for curing colored liquid>
In the present invention, “semi-cured” means partially cured (partially cured) and refers to a state in which the undercoat liquid and / or the colored liquid is partially cured but not completely cured. Say. 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, it is preferable that the undercoat liquid and / or the colored liquid is hardened in the depth direction.

  As a method of semi-curing the undercoat liquid and / or the colored liquid, (1) a basic compound is imparted to the acidic polymer, or an acidic compound or a metal compound is imparted to the basic polymer. A method using an agglomeration phenomenon, (2) an undercoat liquid and / or a colored liquid is prepared in advance to have a high viscosity, and a low boiling point organic solvent is added thereto to reduce the viscosity, and the low boiling point organic solvent is evaporated to obtain the original liquid (3) A method of returning to the original high viscosity by heating and cooling the undercoat liquid and / or coloring liquid prepared to a high viscosity, and (4) an undercoating liquid and / or coloring liquid. Examples include a known thickening method such as a method in which an active energy ray or heat is applied to cause a curing reaction. Among these, (4) a method in which an active energy ray or heat is applied to the undercoat liquid and / or the colored liquid to cause a curing reaction is preferable.

  The method of causing an active energy ray or heat 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 colored liquid applied to the recording medium is insufficiently performed.

  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 proceeds 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 because of the action of inhibiting the 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 active energy ray or heat application conditions.

  Among these, semi-curing by irradiation with active energy rays is preferable. As the active energy ray, α ray, γ ray, electron beam, X ray, ultraviolet ray, visible light, infrared ray or the like can be used. Among these, ultraviolet rays or visible light is preferable, and ultraviolet rays are more preferable. Further, the peak wavelength of the active radiation depends on the absorption characteristics of the sensitizing dye, but is preferably 200 to 600 nm, more preferably 300 to 450 nm, and further preferably 350 to 420 nm, for example. .

The amount of energy required for the semi-curing of the undercoat liquid and / or the coloring liquid varies depending on the type and content of the polymerization initiator, but when energy is applied by active energy rays, it is about 1 to 500 mJ / cm ^2. preferable. In addition, when energy is applied by heating, it is preferable to heat for 0.1 to 1 second under the condition that the surface temperature of the recording medium is in a temperature range of 40 to 80 ° C.

Generation of active species due to decomposition of the polymerization initiator is promoted by application of active energy rays such as actinic light and heating, or heat, and polymerizability or cross-linkability caused by the active species is increased by increasing the active species or increasing the temperature. The curing reaction by polymerization or crosslinking of the material is accelerated.
Moreover, thickening (viscosity increase) can also be suitably performed by irradiation of actinic light or heating.

  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. 2 is a schematic cross-sectional view showing an embodiment of a printed matter obtained by depositing a colored liquid on a semi-cured undercoat liquid layer. At the time of manufacturing the printed matter of FIG. 2, the undercoat liquid is semi-cured, and the curing on the base material 16 side is proceeding more than the surface layer. FIG. 2 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 colored 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 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.

3 and 4 are schematic cross-sectional views showing one embodiment of a printed matter obtained by depositing a colored liquid onto an uncured undercoat liquid layer. 3 and 4 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. 3, in the cross section of the image 10 to be obtained, the colored liquid cured product 12 is completely submerged 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. 4, in the cross section of the obtained image 10, the undercoat layer 18 does not exist below the colored liquid cured product 12.
In this case, even if the coloring liquid is applied at a high density, the droplets are independent from each other, which causes a decrease in color density.

FIG. 5 is a schematic cross-sectional view showing one embodiment of a printed matter obtained by depositing a colored liquid on a completely cured undercoat liquid layer. FIG. 5 shows an undercoat layer 20 in which a colored liquid is applied to a 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. 5, 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, assuming that 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)]
Further, it is more preferable that [m (colored liquid) / 10] ≦ [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. 6 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. 6 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. 6) and colored liquid B cured film (colored film B, colored liquid B cured product 22 in FIG. 6) are laminated. Good color reproduction is possible.

7 and 8 are schematic cross-sectional views showing one embodiment of a printed matter obtained by depositing the colored liquid B on the uncured colored liquid A. FIG. FIG. 7 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 is embedded in the colored liquid A and / or the colored liquid A is not present below the colored liquid B. Become. That is, when a cross-sectional view of the obtained image is observed, as shown in FIG. 7, 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. 9 is a schematic cross-sectional view showing an embodiment of a printed matter obtained by ejecting the colored liquid B onto the completely cured colored liquid A. FIG. In FIG. 9, a colored liquid A cured product 28 and a colored liquid B cured product 22 obtained by adding the colored liquid B to the fully cured colored liquid A are shown. 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. 9, in the cross-sectional view of the obtained image, the colored liquid B cured product 22 does not sink into the colored liquid A cured product 28. 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, if 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.

In addition, the transfer amount (weight) of the colored liquid A per unit area is obtained by a 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, if 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 colored 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.

<Step of completely curing the image>
The “complete curing” in the present invention refers to a state in which the inside and the surface of the undercoat liquid and the coloring liquid are completely cured. Specifically, after the completion of the complete curing process (for example, after irradiation with active energy rays or after heating), was the surface of the undercoat liquid or colored liquid transferred to the permeation medium by pressing the permeation medium such as plain paper? Judgment can be made depending on why. That is, the case where no transfer is performed is called a completely cured state.
As a curing means for completely curing the image, a light source for irradiating active energy rays, a heater such as an electric heater or an oven, and the like can be selected according to the purpose.
As the active energy ray, in addition to ultraviolet rays, for example, visible light, α ray, γ ray, X ray, electron beam and the like can be used. Of these, the active energy rays are preferably electron beams, ultraviolet rays and visible rays, and ultraviolet rays are particularly preferred from the viewpoint of cost and safety.
Full amount of energy required for the curing reaction, the composition, in particular depends on the type and content of the polymerization initiator, it is generally preferred is the extent 100 mJ / cm ² or more 10,000 / cm ² or less.
Suitable devices for irradiating active energy rays include metal halide lamps, mercury lamps, LED light sources and the like.

In addition, when energy is applied by the heating, a device that generates heat can be used as the heating means. In this case, it is preferable that the base material to which the undercoat liquid and the coloring liquid are applied is heated for 0.5 seconds to 10 seconds under the condition that the surface temperature of the base material is in a temperature range of 50 ° C. or higher and 100 ° C. or lower. .
In the case of heating, the temperature rise increases the curing reaction by polymerization or crosslinking of the polymerizable compound, and the shape formed by the collision of the droplets becomes stronger. This is preferable because a strong image can be obtained.
Heating can be performed using a non-contact type heating means, and a heating device that passes through a heating furnace such as an oven or a heating device that exposes the entire surface of ultraviolet light, visible light, infrared light, or the like is suitable. It is.
Examples of light sources suitable for exposure as the heating means include metal halide lamps, xenon lamps, tungsten lamps, carbon arc lamps, mercury lamps and the like.

<Means for controlling humidity>
Further, from the viewpoint of controlling the cured state of the image, in the step of semi-curing the undercoat liquid and / or the step of completely curing the image, the humidity of the semi-cured region of the undercoat liquid and / or the region of the region where the image is completely cured. It is preferable to have a means for controlling.
From the viewpoint of obtaining a preferable semi-cured state, the preferable humidity of the semi-cured region of the undercoat liquid is preferably 40% or more and 80% or less, and the relative humidity in the air is 50% or more and 70%. It is more preferable that the relative humidity in air is 55% or more and 65% or less. The preferred semi-cured state is as described above.
From the viewpoint of improving the curability of the image, it is preferable that the relative humidity in the region where the image is completely cured is 50% or less, and the relative humidity in the air is 40% or less. More preferably, the relative humidity in the air is particularly preferably 30% or less.
The means for controlling the humidity is not particularly limited, but a commercially available humidifier or dehumidifier can be used. From the viewpoint of space saving of the apparatus and ease of control, it is preferable to use a commercially available air conditioning unit. Examples of commercially available air conditioning units include the precision air conditioning unit (temperature / humidity control unit) manufactured by Apiste PAU series (PAU-300S-HC, PAU-A920S-HC, PAU-A1400S-HC, PAU-A2600S-HC, PAU-A3500S-HC).

In FIG. 1, four color liquids of yellow, cyan, magenta, and black are used. However, the present invention is not limited to this, and a white color liquid can also be used. The order of the color liquids to be discharged is not particularly limited, but it is preferable to apply the color liquid having a low brightness to the recording medium. When four colors of yellow, cyan, magenta, and black are used, yellow It is preferable to apply on the recording medium in the order of cyan → magenta → black. Further, in the case of using a coloring liquid of five colors obtained by adding white to this, it is preferably applied on the recording medium in the order of white → yellow → cyan → magenta → black.
At least one colorant may be used, but in order to obtain a full color image, four colorants of yellow, cyan, magenta and black or five colorants of yellow, cyan, magenta, black and white are used. It is preferable to do. Furthermore, the present invention is not limited to this, and eight colored liquids of cyan, light cyan, magenta, light magenta, gray, black, white, and yellow can be used.

<Recording medium>
In the present invention, the material used for the recording medium is not particularly limited, and any material may be used. For example, paper, paper laminated with plastic (eg, polyethylene, polypropylene, polystyrene, etc.), metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, cellulose diacetate, cellulose triacetate, cellulose propionate) Cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), and paper or plastic films on which the above-mentioned metals are laminated or deposited. A preferable support includes a polyester film and an aluminum plate.
In the present invention, a non-absorbable recording medium is preferably used as the recording medium. In the ink jet recording method, by applying the coloring liquid after applying the undercoat liquid, high-definition is achieved with respect to various non-absorbent recording media that have so far been difficult to form fine images due to droplet ejection interference. An image can be formed.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not restrict | limited to these.

The materials used in the present invention are as follows.
PB15: 3 (IRGALITE BLUE GLO; Ciba Specialty Chemicals, cyan pigment)
PV19 (CINQUASIA MAGENTA RT-355D; manufactured by Ciba Specialty Chemicals, magenta pigment)
PY120 (NOVOPERM YELLOW H2G; manufactured by Clariant, yellow pigment)
Carbon black (SPECIAL BLACK 250; manufactured by Degussa, black pigment)
BYK-168 (manufactured by Big Chemie, dispersant)
Solsperse 5000 (Noveon, dispersant)
Rapidure DVE3 (triethylene glycol divinyl ether; manufactured by GAF, diluent)
DPGDA (dipropylene glycol diacrylate; manufactured by Daicel Cytec Co., Ltd., polyfunctional monomer)

(Preparation of cyan pigment dispersion)
PB15: 3 (IRGALITE BLUE GLO) 30 parts by weight Rapicure DVE3 50 parts by weight BYK-168 20 parts by weight The above components were mixed and stirred with a stirrer for 1 hour. The mixture after stirring was dispersed by bead mill dispersion to obtain cyan pigment dispersion A. The bead mill 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 3 hours.

(Preparation of magenta pigment dispersion)
PV19 (CINQUASIA MAGENTA RT-355D) 30 parts by weight Rapicure DVE3 28 parts by weight BYK-168 42 parts by weight The above components were mixed and stirred with a stirrer for 1 hour. The mixture after stirring was dispersed by bead mill dispersion to obtain a magenta pigment dispersion A. The bead mill 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 6 hours.

(Preparation of yellow pigment dispersion)
PY120 (NOVOPERM YELLOW H2G) 30 parts by weight Rapid DVE3 28 parts by weight BYK-168 42 parts by weight The above components were mixed and stirred with a stirrer for 1 hour. The mixture after stirring was dispersed by bead mill dispersion to obtain a yellow pigment dispersion A. The bead mill 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 6 hours.

(Preparation of black pigment dispersion)
Carbon black (SPECIAL BLACK 250) 40 parts by weight Rapidure DVE3 29 parts by weight BYK-168 30 parts by weight Solsperse 5000 1 part by weight The above components were mixed and stirred with a stirrer for 1 hour. The mixture after stirring was dispersed by bead mill dispersion to obtain a black pigment dispersion A. The bead mill 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 3 hours.

(Preparation of liquid composition)
The components shown in Tables 1 to 4 (units are parts by weight) were stirred, mixed and dissolved to obtain liquid compositions. 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 was also in the range of 25 to 27 mN / m. On the other hand, the surface tension of the undercoat liquid was in the range of 20 to 22 mN / m.

Below, the abbreviation of the compound in Table 1-Table 4 is demonstrated.
Polymerizable compound A: DPGDA (dipropylene glycol diacrylate; manufactured by Daicel Cytec Co., Ltd., polyfunctional monomer)
Polymerizable compound B: A-TMPT (trimethylolpropane triacrylate; manufactured by Shin-Nakamura Chemical Co., Ltd., polyfunctional monomer)
Polymerizable compound C: FA512A (dicyclopentenyloxyethyl acrylate; manufactured by Hitachi Chemical Co., Ltd., monofunctional monomer)
Polymerizable compound D: OXT-221 (bis (3-ethyl-3-oxetanylmethyl) ether; manufactured by Toagosei Co., Ltd., compound having an oxetane ring)
Polymerizable compound E: Cel3000 (1,2: 8,9-diepoxy limonene; manufactured by Daicel Chemical Industries, Ltd., a compound having an oxirane ring)
Diluent A: Rapidure DVE3 (triethylene glycol divinyl ether; manufactured by GAF, diluent)
Surfactant A: BYK-307 (Bic Chemie, surfactant)
Inhibitor A: FIRSTCURE ST-1 (manufactured by Albemarle, polymerization inhibitor)
Initiator A: DAROCUR TPO (Ciba Specialty Chemicals, photopolymerization initiator)
Initiator B: IRGACURE 819 (Ciba Specialty Chemicals, photopolymerization initiator)
Initiator C: IRGACURE 369 (2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -1-butanone; photopolymerization initiator manufactured by Ciba Specialty Chemicals)
Initiator D: IRGACURE 907 (2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one; photopolymerization initiator, manufactured by Ciba Specialty Chemicals)
Initiator E: DAROCUR 250 ((4-methylphenyl) [4- (2-methylpropyl) phenyl] iodonium mixture of hexafluorophosphate and propylene carbonate; photopolymerization initiator manufactured by Ciba Specialty Chemicals)
Sensitizer A: Speedcure ITX (mixture of 2-isopropylthioxanthone and 4-isopropylthioxanthone; manufactured by Lambson, sensitizer)
Sensitizer B: 9,10-dibutoxyanthracene Therefore, a colored liquid (M1, C1, Y1, Bk1) containing a radical polymerizable compound is obtained from the components shown in Table 1, and cationic polymerization is performed from the components shown in Table 2. Colored liquid (M2, C2, Y2, Bk2) containing a reactive compound is obtained, and an undercoat liquid (L1) containing a radical polymerizable compound is obtained from the components shown in Table 3, and cationic polymerization is conducted from the components shown in Table 4. An undercoat liquid (L2) containing a functional compound is obtained.

(Image recording device)
The prepared colored liquids for four colors (M1 or M2, C1 or C2, Y1 or Y2, Bk1 or Bk2) are ink jet printers (Toshiba TEC head mounted = droplet ejection frequency: 6.2 KHz, number of nozzles: 636, Nozzle density: 300 npi (nozzle / inch, the same applies below), drop size: 6 pl to 42 pl are arranged in 7 stages, 2 variable heads are arranged in 600 npi and 4 sets of headsets are fully lined. did.
The head is fixed to the machine body in the order of yellow, cyan, magenta, and black in the order from the upstream side of the recording medium conveyance direction, and further, an undercoat liquid roll coater and a semi-curing light source (ultra-high pressure mercury lamp: light intensity 100 mW) upstream of the white ink head. / Cm ² ). Here, the undercoat liquid (L1 or L2) was used as the undercoat liquid.
For the yellow, cyan, and magenta heads that have a structure in which the recording medium can be moved immediately below the heads and that are loaded with colored liquids (M1 or M2, C1 or C2, Y1 or Y2, Bk1 or Bk2). each pinning light source in the traveling direction of the recording medium: the (ultra-high pressure mercury lamp light intensity 100 mW / cm ²⁾ is arranged on the downstream black ink head was placed a metal halide lamp (light intensity 3,000mW / cm ^2).
In addition, the portion irradiated with the semi-curing light source and the pinning light source and the portion irradiated with the metal halide lamp were provided with a plastic box to allow air with adjusted humidity to flow. Here, a precision air conditioning unit (PAU-A3500S-HC, manufactured by Apiste) was used to adjust the humidity in the flowing air. The relative humidity in the air of the portion irradiated with the former semi-curing light source and the pinning light source was set to 55% or more and 65% or less. On the other hand, the relative humidity in the air of the portion irradiated with the latter metal halide lamp was set to 30% or less.
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 A (thickness 50 μm; transparent polyethylene) and a plastic film B (thickness 100 μm; transparent PET) were used as recording media.

Example 1
First, using the above experimental machine, the printed matter A (600 × 600 dpi secondary color (cyan and magenta, yellow and cyan, yellow and magenta) background, or 600 × 600 dpi primary color (cyan, magenta, Black) “Fuji” (Times New Roman, 30 pt)) on the background of yellow), print B (600 × 600 dpi secondary color background (cyan and magenta, yellow and cyan, yellow and magenta)), or 600 × A missing letter “Fuji” (Times New Roman, 30 pt) was created on a background of 600 dpi primary colors (cyan, magenta, yellow). In addition, the undercoat liquid cured film has come out on the surface in the missing character part of the printed matter B here.

The printing procedure is shown in (1) to (10).
(1) The undercoat liquid (L2) was uniformly applied to a thickness of 5 μm by a roll coater (application speed: 400 mm / s).
(2) After applying the undercoat liquid (L2), exposure was performed with a light source for semi-curing (light intensity 100 mW / cm ² ), and the applied undercoat liquid was made into a semi-cured state.
(3) A yellow liquid was formed on the recording medium by a yellow head to form a yellow image.
(4) Exposure was performed with a light source for pinning (light intensity 100 mW / cm ² ), and the yellow colored liquid was made into a semi-cured state.
(5) A cyan color liquid (C1) was applied on the recording medium by a cyan head to form a cyan image.
(6) Exposure was performed with a light source for pinning (light intensity 100 mW / cm ² ), and the cyan coloring liquid was in a semi-cured state.
(7) A magenta color liquid (M1) was applied onto the recording medium by a magenta head to form a magenta image.
(8) Exposure was performed with a light source for pinning (light intensity 100 mW / cm ² ), and the magenta coloring liquid was made into a semi-cured state.
(9) A black colored liquid composition (Bk1) was applied on the recording medium by a black head to form a black image.
(10) Exposure was performed with a metal halide lamp (light intensity: 3,000 mW / cm ² ) to completely cure the image. The irradiation energy here was adjusted to 1,500 mJ / cm ² .

  Here, the conveyance speed of the non-recording medium was 400 mm / s, and the amount of colored liquid per dot was about 12 picoliters. 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. Further, the relative humidity in the air during the steps (2) to (8) is set to 55% or more and 65% or less, and the relative humidity in the air during the step (10) is 30% or less. Was set as follows.

(Comparative Examples 1-3)
As described in Table 3, an image was prepared in the same manner as in Example 1 except that the coloring liquid and the undercoat liquid were replaced.

(Transcription test)
In any of Example 1 and Comparative Examples 1 to 3, the maximum amount of the colored liquid applied per unit area applied in the steps (3), (5), (7), and (9) is 0 for each colored liquid. Within the range of .74 mg / cm ² to 0.87 mg / cm ² .
After the exposure with the semi-curing light source and the exposure with the pinning light source in the steps (2), (4), (6), (7), (8), the sample is extracted and the uncured primer solution is removed by a transfer test. was weighed, it was in the range of 0.10 mg / cm ² of 0.12 mg / cm ² even after any step.
Accordingly, 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.
Further, the amount of uncured yellow colored liquid after exposure to the light source for pinning in the step (4), the amount of uncured liquid of cyan colored liquid after the exposure to the light source for pinning in the step (6), and the light source for pinning in the step (8) The uncured liquid amount of the magenta coloring liquid after the exposure was measured by a transfer test after extracting a sample after each step. The amount of liquid also uncured for any coloring liquid was in the range of 0.10 mg / cm ² of 0.12 mg / cm ² even after any step.
Accordingly, in a combination of colored liquids having different hues, the weight M (colored liquid A) of the colored liquid A uncured portion applied first on the recording medium and the unit area of the colored liquid B applied later. The relationship of the maximum weight m (colored liquid B) per hit was m (colored liquid B) / 10 <M (colored liquid A) <m (colored liquid B) / 5.
The transfer test was performed 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 extracted, 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-section observation of the obtained printed matter)
Moreover, the obtained printed matter A (each printed matter A produced with three kinds of primary colors and secondary colors) was cut with a microtome and observed with an optical microscope (an optical microscope measuring microscope MM-40 manufactured by Nikon). did. A microtome (Leica Microtome RM2255) was used to obtain a section.

  In the primary color portion of the image obtained in Example 1, a part of the colored liquid cured product 12 is exposed on the surface as shown in FIG. I was submerged. Further, an undercoat layer 14 was observed below the colored liquid cured product 12. Furthermore, formation of the cured layer 12 of a uniform colored liquid was confirmed.

  In the image obtained in Example 1, the secondary color (when formed with the coloring liquid A and the coloring liquid B) is part of the colored liquid B cured product 22 as shown in FIG. It appeared on the surface, and part of it 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.

(Sensory evaluation of images)
Sensory evaluation was performed according to the following evaluation criteria. The results are shown in Table 5.
<Fixability evaluation criteria>
According to the following evaluation criteria, evaluation of image fixability was performed using printed materials A and B of secondary colors using yellow and cyan. The results are shown in Table 5.
The image was fixed by rubbing with an eraser and rubbing the characters and background. The evaluation criteria were as follows.
○ The film is not peeled or torn and the fixability is good △ Some of the film is peeled off and the fixability is poor and the fixability is poor × The entire surface is peeled off and the fixability is poor and the fixability is poor

<Evaluation criteria for printed curls>
For all printed matter A created using the secondary colors (cyan and magenta, yellow and cyan, yellow and magenta) and primary colors (cyan, magenta, yellow), the plastic film A cut to 10 × 10 cm The printed matter was placed on a horizontal base, the floating of each vertex was measured, and the degree of curling was evaluated. Evaluation criteria were as follows.
○ There was no floating of each vertex, and curling of printed matter did not occur.
(Triangle | delta) The float of each vertex was less than 1 cm, and the curl of the printed matter was small.
X The float of each vertex was 1 cm or more, and the curl of the printed matter was large. Some prints were completely bent.
In addition, in the description of the results in Table 5, when all the printed materials A and B are evaluated as “good”, none of the printed materials A and B are evaluated as “x”, and all When one of the printed materials A and B was evaluated as Δ, Δ was evaluated when the evaluation was × even when one of all printed materials A and B was evaluated as ×.

<Evaluation criteria for ejection stability>
For all prints A and B created using the secondary colors (cyan and magenta, yellow and cyan, yellow and magenta) and primary colors (cyan, magenta and yellow), prints A and B are 5 respectively. The ejection stability was evaluated based on the number of printed materials that were printed continuously for a period of time and non-ejection occurred (note that the exposure light source was kept on for 5 hours during printing). Evaluation criteria were as follows.
○ The number of streaks due to non-ejection was 5 or less, and the ejection stability was good.
Δ The number of streaks due to non-ejection was 6 to 20 and the ejection stability was poor.
X The number of streaks due to non-ejection was 21 or more, and the ejection stability was poor.
In addition, in the description of the results in Table 5, when all the printed materials A and B are evaluated as “good”, none of the printed materials A and B are evaluated as “x”, and all When one of the printed materials A and B was evaluated as Δ, Δ was evaluated when the evaluation was × even when one of all printed materials A and B was evaluated as ×.

It is an example of the conceptual diagram of the inkjet recording device which can be used suitably for this invention. It is a conceptual diagram of the cross-sectional observation in the printed matter which gave the colored liquid in the semi-cured undercoat liquid layer. It is a conceptual diagram of the cross-sectional observation in the printed matter which gave the coloring liquid in the uncured undercoat liquid layer. It is another conceptual diagram of the cross-section observation in the printed matter which gave the coloring liquid in the uncured undercoat liquid layer. It is a conceptual diagram of the cross-sectional observation in the printed matter which gave the colored liquid in the undercoat liquid layer in a completely cured state. It is a conceptual diagram of the cross-sectional observation in the printed matter to which the colored liquid A layer gave the colored liquid B in a semi-cured state. It is a conceptual diagram of the cross-sectional observation in the printed matter which provided the coloring liquid B in the uncured colored liquid A layer. It is another conceptual diagram of the cross-sectional observation in the printed matter which provided the colored liquid B in the uncured colored liquid A layer. It is a conceptual diagram of cross-sectional observation in the printed matter to which the colored liquid A layer has been applied and the colored liquid B is applied in a completely cured state. It is a conceptual schematic diagram which shows the image formed in the Example.

Explanation of symbols

1 Means for applying undercoat liquid 2 Means for semi-curing undercoat liquid 3Y, 3C, 3M, 4K Means for applying colored liquid 4Y, 4C, 4M, 4K Means for semi-curing colored liquid 5 Means for completely curing image 6 Recording medium 7A, 7B Recording medium transport means 10 Image 12 Colored liquid cured product 14 Undercoat layer 16 in which colored liquid is applied to semi-cured undercoat liquid layer Base material 18 Colored liquid in uncured undercoat liquid layer The undercoat layer 20 provided with the undercoat layer 22 provided with the coloring liquid in the completely cured undercoat liquid layer The colored liquid B cured product 24 The colored liquid obtained by applying the colored liquid B to the semi-cured colored liquid A A cured product 26 Colored solution A cured product 28 obtained by applying colored solution B to uncured colored solution A Colored solution A cured product obtained by applying colored solution B to completely cured colored solution A Object 400 Background 401 Black ink Part 402 white area

Claims (11)

Applying an undercoat liquid onto the recording medium;
Semi-curing the undercoat liquid;
Discharging the colored liquid A onto the semi-cured undercoat liquid to form an image;
A step of semi-curing the colored liquid A;
A step of discharging the colored liquid B onto the semi-cured colored liquid A to form an image;
A step of completely curing the undercoat liquid, the colored liquid A and the colored liquid B,
The colored liquid A and the colored liquid B each contain at least a radical polymerizable compound, a radical polymerization initiator, and a colorant ,
Said undercoating liquid, at least a cationically polymerizable compound, and, characterized by a Turkey to contain a cationic polymerization initiator
Inkjet recording method . The inkjet recording method according to claim 1, wherein the cationically polymerizable compound is at least one oxetane ring-containing compound and at least one oxirane ring-containing compound. The inkjet recording method according to claim 1, wherein the radical polymerizable compound is at least one selected from the group consisting of a monofunctional (meth) acrylate and a bifunctional (meth) acrylate. The inkjet recording method according to claim 1, wherein the undercoat liquid contains a surfactant. The inkjet recording method according to claim 1, wherein γA> γB is satisfied, where γA is a surface tension of the colored liquid and γB is a surface tension of the undercoat liquid. In the step of semi-curing the undercoat liquid and / or the step of completely curing the undercoat liquid and the colored liquid , the relative humidity in the air in the region where the undercoat liquid is semi-cured is 40% or more and 80% or less, and / or, wherein the undercoating liquid and ink jet recording method according to any one of claims 1 to 5 for performing the colored liquid completely with a relative humidity in the air in the region to be hardened 50% or less.   The colored liquid A and the colored liquid B both contain isopropylthioxanthone as a sensitizer, and the undercoat liquid contains 9,10-dibutoxyanthracene as a sensitizer. The ink jet recording method described in 1.   The inkjet recording method according to claim 1, wherein both the radical polymerizable compound in the colored liquid A and the radical polymerizable compound in the colored liquid B include a vinyl ether compound.   The inkjet recording method according to claim 8, wherein both the radical polymerizable compound in the colored liquid A and the radical polymerizable compound in the colored liquid B contain tripropylene glycol divinyl ether.   Each of the radical polymerizable compound in the colored liquid A and the radical polymerizable compound in the colored liquid B includes monofunctional (meth) acrylate, bifunctional (meth) acrylate, and trifunctional (meth) acrylate. The ink jet recording method according to claim 1.   The inkjet recording according to any one of claims 1 to 10, wherein the cationically polymerizable compound includes bis (3-ethyl-3-oxetanylmethyl) ether and 1,2: 8,9-diepoxy limonene. Method.

Images