JP2009102455A - Polymerization initiator for active energy beam, curing type liquid composition containing the initiator, ink, inkjet recording method, recorded image, ink cartridge, recording unit, and inkjet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide polymerization sensitizer having excellent responsiveness to active energy beam and excellent efficiency for starting the generation of many radicals and to provide a liquid composition being quickly polymerized by active energy beams, having excellent adhesiveness to a basic material, and capable of achieving high degree of crosslinking of a substance to be cured. <P>SOLUTION: The active energy beam polymerization sensitizer is expressed in formula (I) (wherein, R<SB>1</SB>denotes -(A)-COOM or -(A)- SO<SB>3</SB>M (here, (A) denotes oxyalkylene group which may be single bonded or be branched and M denotes one of hydrogen atom, alkaline metal, alkaline earth metal, and ammonium), R<SB>2</SB>and R<SB>3</SB>are independent from each other and denote one of hydrogen atom, alkyl group, alkenyl group, and benzyl group, R<SB>4</SB>, R<SB>5</SB>, R<SB>6</SB>, and R<SB>7</SB>are independent from each other and denote one of alkyl group, benzyl group, and phenyl group or R<SB>4</SB>and R<SB>5</SB>and/or R<SB>6</SB>and R<SB>7</SB>form cyclic functional group, respectively) and the active energy beam curing type liquid composition contains the polymerization sensitizer and radical polymerizing substance. The liquid composition is useful as ink for inkjet recording. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a novel active energy ray polymerization initiator, a curable liquid composition containing the polymerization initiator, an ink, an ink jet recording method, a recorded image, an ink cartridge, a recording unit, and an ink jet recording apparatus.

  The active energy ray curable ink has excellent characteristics such as a reduction in the amount of VOC (volatile organic compound) generated, high energy efficiency, quick drying, and compatibility with various recording media. For this reason, it is widely used in printing fields such as offset printing, screen printing, and gravure printing. In addition, a technique for applying an active energy ray curable ink to an ink jet recording method is also known, and it is applied to the production of electronic circuit boards and display panels in addition to graphic art, printing of signs, displays, labels or packages. ing.

  Non-aqueous and aqueous inks are known as active energy ray curable inks. Non-aqueous inks are roughly classified into two types, and one type is a so-called oil-based ink in which a pigment is dispersed in an organic solvent such as toluene or methyl ethyl ketone. As another type, 100% curable ink (non-solvent ink) that does not use an organic solvent is known. However, when using the oil-based ink, since the organic solvent is volatilized in the atmosphere, sufficient consideration for the environment is necessary. The above-mentioned 100% curable ink has a large step between the recording portion and the non-recording portion on the recording medium, and it is difficult to obtain smoothness and glossiness of the image. Is currently difficult.

  On the other hand, since the aqueous one uses almost no organic solvent, it is more environmentally advantageous than the non-aqueous one. Further, when diluted with water, the solid content concentration is lowered, and the unevenness of the recorded image is alleviated, so that it is more advantageous than the non-aqueous one from the viewpoint of high image quality. For these reasons, there are high expectations for aqueous active energy ray-curable inks, particularly aqueous active energy ray-curable inks that can also be applied to inkjet recording. From this point of view, hydrophilic polymerizable substances (polymers, polyfunctional monomers, monofunctional monomers, etc.) applicable to water-based active energy ray-curable inks for ink jet recording, and hydrophilic photopolymerization initiators Development is required.

  Among these, as a hydrophilic polymerization initiator, Patent Document 1 discloses a thioxanthone polymerization initiator imparted with water solubility by adding a functional group containing a polyethylene oxide chain or a carboxyl group or a sulfone group. Yes.

  Patent Document 2 discloses an α-hydroxyphenyl ketone polymerization initiator imparted with water solubility by addition of a polyethylene oxide chain. In addition, Patent Document 3 discloses α-hydroxy having water solubility by adding a functional group including a carboxyl group and a sulfone group as a polymerization initiator useful for producing an aqueous polymer solution or polymer dispersion. A phenyl ketone polymerization initiator is disclosed.

  Furthermore, Patent Document 4 discloses acylphosphine oxides having an ionic functional group as a polymerization initiator useful for the polymerization of an aqueous polymerizable composition such as a coating material, printing ink, unsaturated polyester molding material or recording material. A polymerization initiator is disclosed.

JP 2002-186242 A JP 2002-187918 A JP-A-6-228218 JP 57-197289 A

  Aqueous active energy ray curable inks have the above-mentioned excellent characteristics. On the other hand, as described above, when diluted with water for the purpose of alleviating the unevenness of the recorded image, the curing performance decreases. Is concerned. Curing performance is improved by increasing the content of polymerizable substances and polymerization initiators. However, especially when applied to inkjet recording methods, it is restricted by the viscosity of the ink and must be contained in large amounts. I can't. For this reason, in such a case, the curing performance of the ink greatly depends on the characteristics of the individual materials constituting the ink.

  Further, it is a big problem that the black ink is hard to cure due to the absorption of the active energy rays by the coloring material. For this reason, in such a case, a polymerization initiator that exhibits high responsiveness to short-term active energy ray irradiation and is capable of generating many radicals is required. .

  Since the polymerization initiator described in Patent Document 1 is a hydrogen abstraction type, there is a problem that a hydrogen donor such as a tertiary amine is separately required. In addition, since the polymerization initiator itself is colored, there is also a problem that it is not suitable for a clear ink.

  The polymerization initiators described in Patent Document 2 and Patent Document 3 are excellent in compatibility with water and a polymerizable substance, but have a problem that they are somewhat insufficient in terms of initiation efficiency.

  The polymerization initiator described in Patent Document 4 has high quantum yield of radical generation, high reactivity of radicals having unpaired electrons on phosphorus atoms, and long lifetime of the generated radicals. It has characteristics and has high starting efficiency. Moreover, water solubility is also favorable. However, since oxygen is easily inhibited, there is a problem that the curability in a portion where oxygen is likely to diffuse, such as the vicinity of the surface of the ink droplet, is slightly insufficient.

  In addition, the present inventors have also studied a synergistic effect by using a combination of polymerization initiators having different characteristics. For example, a polymerization initiator of Patent Document 2 that is an α-hydroxyketone system that is excellent in surface curing and is not easily affected by oxygen inhibition, and a polymerization initiator of Patent Document 4 that is an acylphosphine oxide system that is excellent in internal curing and is susceptible to oxygen inhibition. We expected a synergistic effect when used in combination. However, the remarkable effect brought about by the combination of the above polymerization initiators was not observed.

  Accordingly, a first object of the present invention is to provide an active energy ray polymerization initiator that exhibits high responsiveness to active energy rays and is capable of generating many radicals and excellent in starting efficiency. .

  A second object of the present invention is to provide an active energy ray-curable liquid composition that is rapidly polymerized by active energy rays, has a high degree of crosslinking of the cured product, and is excellent in adhesion to a substrate.

  The third object of the present invention is to provide a hydrophilic active energy ray-curable liquid composition that is rapidly polymerized by active energy rays, has a high degree of crosslinking of the cured product, and is excellent in adhesion to a substrate. is there. Furthermore, another object of the present invention is to provide an active energy ray-curable ink which exhibits such characteristics and can be applied to ink jet recording whose viscosity satisfies a level required for an ink jet recording method.

  The fourth object of the present invention is to rapidly polymerize by active energy rays, the degree of cross-linking of the cured product is high, the viscosity meets the low viscosity level required for the ink jet recording method, and high-quality images can be formed. Another ink jet recording method. Furthermore, an ink jet recording method using an active energy ray-curable ink that has excellent ejection stability even when the recording method is an ink jet recording method in which thermal energy corresponding to a recording signal is applied and ink droplets are ejected by the energy. It is to provide.

［一般式（Ｉ）中、Ｒ₁は、−（Ａ）−ＣＯＯＭ又は−（Ａ）−ＳＯ₃Ｍ（ここで（Ａ）は、単結合或いは分岐していてよいオキシアルキレン基を示し、Ｍは、水素原子、アルカリ金属、アルカリ土類金属及びアンモニウムのいずれかを示す）を示し、Ｒ₂及びＲ₃は互いに独立して、水素原子、アルキル基、アルケニル基及びベンジル基のいずれかを示し、Ｒ₄、Ｒ₅、Ｒ₆及びＲ₇は互いに独立して、アルキル基、ベンジル基及びフェニル基のいずれかを示すか、或いは、Ｒ₄とＲ₅及び／又はＲ₆とＲ₇はそれぞれ環状官能基を形成している。］ The above object is achieved by the present invention described below. As a first embodiment of the present invention, there is provided an active energy ray polymerization initiator (hereinafter sometimes simply referred to as “polymerization initiator”) characterized by being represented by the following general formula (I).

[In General Formula (I), R ₁ represents — (A) —COOM or — (A) —SO ₃ M (where (A) represents a single bond or branched oxyalkylene group; Represents any one of a hydrogen atom, an alkali metal, an alkaline earth metal and ammonium), and R ₂ and R ₃ each independently represent any one of a hydrogen atom, an alkyl group, an alkenyl group and a benzyl group. , R ₄ , R ₅ , R ₆ and R ₇ are independently of each other an alkyl group, a benzyl group or a phenyl group, or R ₄ and R ₅ and / or R ₆ and R ₇ are respectively A cyclic functional group is formed. ]

  Further, as a second embodiment of the present invention, it is characterized by containing at least an active energy ray polymerization initiator represented by the general formula (I) and a polymerizable substance that undergoes radical polymerization by active energy rays. An active energy ray-curable liquid composition is provided.

  In addition, the third embodiment of the present invention is characterized in that it contains at least the active energy ray polymerization initiator of the present invention, a polymerizable substance that undergoes radical polymerization with active energy rays, and a coloring material. An active energy ray-curable ink (hereinafter sometimes simply referred to as “ink”) is provided.

  Further, as a fourth embodiment of the present invention, a step of ejecting the ink of the present invention for inkjet recording onto a recording medium, and irradiating the recording medium with the ink irradiated with active energy rays There is provided an inkjet recording method comprising a step of curing the ink.

  Further, as a fifth embodiment of the present invention, a recording image formed by the ink jet recording method of the present invention, and an ink storage portion in which the ink of the present invention for ink jet recording is stored An ink cartridge for ink jet recording, and an ink storage portion for storing the ink of the present invention for ink jet recording, and a recording head for discharging the ink. A recording unit, means for applying the ink of the present invention for ink jet recording onto a recording medium, and means for irradiating the ink applied to the recording medium with active energy rays. An inkjet recording apparatus is provided.

  According to the first embodiment of the present invention, an active energy ray polymerization initiator that exhibits high responsiveness to short-term active energy ray irradiation and is capable of generating many radicals and excellent in starting efficiency. Is provided.

  According to the second embodiment of the present invention, there is provided an active energy ray-curable liquid composition that is rapidly polymerized by active energy rays, has a high degree of crosslinking of the cured product, and is excellent in adhesion to a substrate. .

  According to the third embodiment of the present invention, hydrophilic active energy ray curing suitable for ink jet recording, which is rapidly polymerized by active energy rays, has a high degree of crosslinking of the cured product, and is excellent in adhesion to a substrate. A mold ink is provided.

  According to the fourth embodiment of the present invention, it is possible to provide an ink jet recording method using an ink having excellent ejection stability even in an ink jet recording system in which ink droplets are ejected by applying thermal energy. it can.

  According to the fifth embodiment of the present invention, a recording image formed by the recording method, an ink cartridge having the ink, a recording unit, and an ink jet recording apparatus can be provided.

  Hereinafter, the present invention will be described in more detail with reference to preferred embodiments. In view of the above-mentioned object, the present inventors have found a polymerization initiator that generates radicals by active energy rays, represented by the following general formula (I), in the course of various studies. An active energy ray-curable ink composition or a liquid composition containing at least water, a polymerization initiator of the following general formula (I), and a hydrophilic polymerizable substance that undergoes radical polymerization by active energy rays It was prepared and evaluated by an image formation test. As a result, the active energy ray-curable ink having such a structure is rapidly polymerized by the active energy rays, and the formed cured product has a high degree of cross-linking, and also has an adhesive property to the recording medium as a substrate. As a result, the present invention was found out.

［一般式（Ｉ）中、Ｒ₁は、−(Ａ)−ＣＯＯＭ又は−(Ａ)−ＳＯ₃Ｍ（ここで（Ａ）は、単結合或いは分岐していてよいオキシアルキレン基を示し、Ｍは、水素原子、アルカリ金属、アルカリ土類金属及びアンモニウムのいずれかを示す）を示す。Ｒ₂及びＲ₃は互いに独立して、水素原子、アルキル基、アルケニル基及びベンジル基のいずれかを示す。Ｒ₄、Ｒ₅、Ｒ₆及びＲ₇は互いに独立して、アルキル基、ベンジル基及びフェニル基のいずれかを示すか、或いは、Ｒ₄とＲ₅及び／又はＲ₆とＲ₇はそれぞれ環状官能基を形成している。］

[In the general formula (I), R ₁ represents — (A) —COOM or — (A) —SO ₃ M (wherein (A) represents an oxyalkylene group which may be a single bond or branched; Represents a hydrogen atom, an alkali metal, an alkaline earth metal, or ammonium). R ₂ and R ₃ each independently represent a hydrogen atom, an alkyl group, an alkenyl group or a benzyl group. R ₄ , R ₅ , R ₆ and R ₇ are each independently an alkyl group, a benzyl group or a phenyl group, or R ₄ and R ₅ and / or R ₆ and R ₇ are each cyclic. A functional group is formed. ]

  The liquid composition represented by the active energy ray-curable ink of the present invention includes an active energy ray polymerization initiator of the present invention represented by the general formula (I), a polymerizable substance that undergoes radical polymerization with active energy rays, It contains at least a color material. When an image is formed using the ink of the present invention having such a configuration, the reason why the ink component is rapidly polymerized by active energy rays and the formed cured product has a high degree of crosslinking is considered as follows. As is clear from the structural formula, the active energy ray polymerization initiator represented by the general formula (I) of the present invention is a bifunctional polymerization initiator having two radical generating sites in the molecular structure. is there. For this reason, the polymerization initiator of the present invention is cleaved into three parts by irradiation with active energy rays due to its structural characteristics to generate two monoradicals and one biradical. Thus, the generation of a large number of radical species locally at a time means that the number of radicals that avoid oxygen inhibition and start polymerization is increased. As a result, it is assumed that the polymerization rate is improved. Moreover, it is thought that the network of polymer chains grows when the generated biradical acts as a crosslinking agent. As a result, it is assumed that the degree of crosslinking of the cured product is improved.

  On the other hand, the α-hydroxyketone-based polymerization initiator such as the polymerization initiator of the present invention contained in the ink of the present invention itself is not susceptible to oxygen inhibition and absorbs in the ultraviolet short wavelength region. It has excellent surface curability because it has. When the surface is cured, diffusion of oxygen into the ink droplet is suppressed when applied to an ink jet recording method. As a result, it is assumed that curing proceeds efficiently.

  Furthermore, the polymerization initiator represented by the general formula (I) of the present invention is rendered hydrophilic by introducing a hydrophilic group into a portion that becomes a biradical after cleavage. Therefore, the biradical having the excellent characteristics as described above maintains high compatibility and diffusibility with respect to water and hydrophilic polymerizable substances. As a result, it is presumed that a network of polymer chains is efficiently formed over the entire ink droplet, and the degree of cross-linking of the cured product and the adhesion to the substrate are increased.

The operation and effect of printing by the ink jet recording method, which is a main application example of the ink of the present invention, will be described below.
When the active energy ray-curable ink of the present invention is printed by an aqueous ink jet recording method and irradiated with active energy rays, many radicals are instantaneously generated from the active energy ray polymerization initiator of the present invention. The rapid polymerization caused by the radicals increases the degree of cross-linking of the cured product and increases the adhesion to the substrate. By such an action, it is possible to expect effects such as suppression of scratches, improvement of marker resistance and improvement of fixability as printed matter. In addition, examples of active energy rays that can be used when the ink of the present invention is applied to an ink jet recording system include ultraviolet rays and electron beams, and the description will be given below using particularly preferred ultraviolet rays. However, this does not mean that the active energy ray referred to in the present invention is limited to ultraviolet rays.

  Next, each constituent material of the ink of the present invention having the above-described excellent actions and effects will be described.

(Hydrophilic polymerization initiator)
The active energy ray-curable liquid composition of the present invention or the ink of the present invention contains at least the active energy ray polymerization initiator of the present invention described below and a polymerizable substance that undergoes radical polymerization with active energy rays. It is characterized by that. Since the active energy ray polymerization initiator of the present invention has hydrophilicity, it is useful as an active energy ray-curable liquid composition or ink component that can be suitably used for inkjet recording. In the present invention, “the polymerization initiator is hydrophilic” means that the polymerization initiator includes any of the following states.
(1) It is soluble in an organic solvent miscible with water, and the organic solvent solution is water-soluble.
(2) Even if the polymerization initiator itself is water-insoluble, it is treated in a form that can be emulsified in water.
(3) It is water soluble.

［一般式（Ｉ）中、Ｒ₁は、−(Ａ)−ＣＯＯＭ又は−(Ａ)−ＳＯ₃Ｍ（ここで（Ａ）は、単結合或いは分岐していてよいオキシアルキレン基を示し、Ｍは、水素原子、アルカリ金属、アルカリ土類金属及びアンモニウムのいずれかを示す）を示す。Ｒ₂及びＲ₃は互いに独立して、水素原子、アルキル基、アルケニル基及びベンジル基のいずれかを示す。Ｒ₄、Ｒ₅、Ｒ₆及びＲ₇は互いに独立して、アルキル基、ベンジル基及びフェニル基のいずれかを示すか、或いは、Ｒ₄とＲ₅及び／又はＲ₆とＲ₇はそれぞれ環状官能基を形成している。］ The active energy ray polymerization initiator of the present invention is represented by the following general formula (I).

[In the general formula (I), R ₁ represents — (A) —COOM or — (A) —SO ₃ M (wherein (A) represents an oxyalkylene group which may be a single bond or branched; Represents a hydrogen atom, an alkali metal, an alkaline earth metal, or ammonium). R ₂ and R ₃ each independently represent a hydrogen atom, an alkyl group, an alkenyl group or a benzyl group. R ₄ , R ₅ , R ₆ and R ₇ are each independently an alkyl group, a benzyl group or a phenyl group, or R ₄ and R ₅ and / or R ₆ and R ₇ are each cyclic. A functional group is formed. ]

  The active energy ray polymerization initiator suitable for the liquid composition or ink of the present invention is a hydrophilic polymerization initiator having an anionic functional group in a portion that becomes a biradical after cleavage, as can be seen from the general formula (I). is there. Since the anionic functional group has a higher hydrophilicity than the nonionic functional group, a smaller number of functional groups than the nonionic functional group is required to obtain the desired hydrophilicity. As a result, the molecular weight as a polymerization initiator can be suppressed, and when formulated into a liquid composition or ink, it can be advantageous in terms of the number of moles contained.

In the active energy ray polymerization initiator of the present invention represented by the general formula (I) (hereinafter also simply referred to as polymerization initiator), the substitution position of the anionic functional group is represented by R ₁ . R ₁ is represented by-(A) -COOM or-(A) -SO ₃ M, and (A) is preferably a single bond, oxypropylene or oxybutylene. In addition, M is preferably a hydrogen atom, an alkali metal such as lithium, sodium and potassium, or ammonium such as ammonium, dimethylethanolammonium, methyldiethanolammonium, triethanolammonium and anilinium. R ₂ and R ₃ are preferably independently of each other a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 3 to 6 carbon atoms, or a benzyl group. R ₄ , R ₅ , R ₆ and R ₇ are preferably any one of an alkyl group having 1 to 8 carbon atoms, a benzyl group, a phenyl group and a cyclohexyl group, independently of each other. Of course, R _{1 to} R ₇ described above are not limited to the functional groups exemplified above.

  Particularly preferred specific examples of the active energy ray polymerization initiator represented by the general formula (I) include, for example, those having the structures shown below. However, the present invention is not limited to these. Two or more specific compounds corresponding to the active energy ray polymerization initiator disclosed in the present invention may be used in combination.

  The active energy ray polymerization initiator represented by the general formula (I) of the present invention can be produced by the following method.

(Synthesis method)
The method for synthesizing the bifunctional α-hydroxyketone polymerization initiator is described in, for example, JP-B-5-72898, JP-A-2005-508378, and International Publication No. 2004/099262. . The method for introducing a hydrophilic group is described in, for example, Japanese Patent Publication No. 7-2769.

［一般式（II）中、Ｒ₈はアルキル基又はフェニル基を示し、Ｒ₉はアルコキシ基又はフェニル基を示し、Ｒ₁₀は下記一般式（III）を示す。

一般式（III）中、Ｒ₁₁は、−[ＣＨ₂]_x1−（ｘ１は０又は１）又はフェニレン基を示し、ｍ１は０乃至１０のいずれかの整数を示し、ｎ１は０又は１を示す。Ｒ₁₂は、水素原子、スルホン基、カルボキシル基、ヒドロキシル基及びこれらの塩から選ばれるいずれかを示す。］ As a preferable form of the liquid composition or ink of the present invention, in addition to the active energy ray polymerization initiator represented by the general formula (I), an active energy ray polymerization initiator represented by the following general formula (II) Can be mentioned.

[In general formula (II), R ₈ represents an alkyl group or a phenyl group, R ₉ represents an alkoxy group or a phenyl group, and R ₁₀ represents the following general formula (III).

In the general formula (III), R ₁₁ represents — [CH ₂ ] _x1 — (x1 is 0 or 1) or a phenylene group, m1 represents an integer of 0 to 10, and n1 represents 0 or 1. Show. R ₁₂ represents any one selected from a hydrogen atom, a sulfone group, a carboxyl group, a hydroxyl group, and salts thereof. ]

  The acylphosphine oxide-based polymerization initiator represented by the general formula (II) has absorption in a longer wavelength region and is excellent in light transmittance than a conventionally used polymerization initiator. Moreover, it is cleaved by irradiation with active energy rays to generate a highly reactive phosphinoyl radical having an unpaired electron on the acyl radical and phosphorus atom. For this reason, since the starting efficiency is high and the internal curability is excellent, the surface curability is slightly inferior because it is susceptible to oxygen inhibition.

  According to the study by the present inventors, it has been found that the combination of the polymerization initiators as described above can provide a synergistic effect that could not be seen conventionally. That is, when the active energy ray polymerization initiator of the present invention represented by the general formula (I) excellent in surface curability and the active energy ray polymerization initiator represented by the general formula (II) excellent in internal curability are combined. Thus, improvement in curing performance due to these synergistic effects can be expected.

  As a particularly preferable specific example of the active energy ray polymerization initiator represented by the general formula (II), for example, those having the structures shown below can be mentioned. However, the present invention is not limited to these.

  As the active energy ray polymerization initiator having excellent internal curability, in addition to the acylphosphine oxide polymerization initiator represented by the general formula (II), a polymerization initiator such as an α-aminoketone or acyloxime ketone is also used. can do.

(Hydrophilic polymerizable substance)
The polymerizable substance used in the liquid composition or ink of the present invention is hydrophilic. In the present invention, the fact that the polymerizable substance is hydrophilic means that the polymerizable substance is in the following state.
(1) It is soluble in an organic solvent miscible with water, and the organic solvent solution is water-soluble.
(2) Even if the polymerizable substance itself is water-insoluble, it is treated in a form that can be emulsified in water.
(3) It is water soluble.

［一般式（IV）中、Ｚはポリオールの残基を示し、ｍ２は１乃至６の整数を示し、ｎ２は０乃至２の整数を示し、ｍ２＋ｎ２は２乃至６の整数を示し、Ｘは、水素原子、メチル基又はハロゲン原子を示す。また、（Ｂ）は、置換基を有していてもよいエチレンオキシド鎖及び置換基を有していてもよいプロピレンオキシド鎖の少なくとも一方を示し、かつ（Ｂ）におけるエチレンオキサイドユニットの数及びプロピレンオキサイドユニットの数の合計は１乃至６である。また、Ｒ₁₃は、単結合又は炭素数１乃至６の分岐していてもよい置換又は未置換のアルキレン基を示す。 The liquid composition or ink of the present invention comprises the active energy ray polymerization initiator of the present invention described above, a polymerizable substance that is radically polymerized by active energy rays (hereinafter simply referred to as a polymerizable substance), and a coloring material. It contains at least. The polymerizable substance used in this case is preferably a hydrophilic substance, and particularly preferably a compound represented by the following general formula (IV).

[In general formula (IV), Z represents a polyol residue, m2 represents an integer of 1 to 6, n2 represents an integer of 0 to 2, m2 + n2 represents an integer of 2 to 6, and X represents A hydrogen atom, a methyl group or a halogen atom is shown. (B) represents at least one of an ethylene oxide chain which may have a substituent and a propylene oxide chain which may have a substituent, and the number of ethylene oxide units and propylene oxide in (B) The total number of units is 1-6. R ₁₃ represents a single bond or a substituted or unsubstituted alkylene group having 1 to 6 carbon atoms which may be branched.

上記結合中、Ｒ₁₄、Ｒ₁₅、Ｒ₁₆、Ｒ₁₇は互いに独立して水素原子、メチル基及びエチル基のいずれか１つを示す。］ Further, (C) in the general formula (IV) represents any one selected from a linking group consisting of the following groups.

In the above bond, R ₁₄ , R ₁₅ , R ₁₆ and R ₁₇ each independently represent any one of a hydrogen atom, a methyl group and an ethyl group. ]

  The number of polymerizable functional groups of the polymerizable substance used in the liquid composition or ink of the present invention is preferably in the range of 2 to 6 from the viewpoint of curing performance and low viscosity of the liquid composition or ink. The range of 3 to 4 is preferable.

  The compound represented by the general formula (IV) suitable for the polymerizable material of the liquid composition or ink component of the present invention is an ethylene oxide chain / propylene oxide contained in the group (B) in the general formula (IV). Hydrophilicity is imparted by the chain and the hydroxyl group. The number of ethylene oxide chains or propylene oxide chains contained in the group (B) in the general formula (IV) is preferably in the range of 0 to 5, more preferably in the range of 1 to 3. In addition, the total number of ethylene oxide units and propylene oxide units in (B) is preferably 2 to 4.

  The polyol residue represented by Z in the general formula (IV) is obtained by removing two or more hydroxyl groups from a polyol. Preferred polyols in this case include the following. For example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1 , 4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,4-pentanediol, 2,4-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2 , 4-pentanediol, 1,5-hexanediol, 1,6-hexanediol, 2,5-hexanediol, glycerin, 1,2,4-butanetriol, 1,2,6-hexanetriol , 1,2,5-pentanetriol, thiodigly Lumpur, trimethylolpropane, ditrimethylolpropane, trimethylolethane, di-trimethylolpropane, neopentyl glycol, and pentaerythritol, dipentaerythritol, and the like of these condensates. Particularly preferred examples include glycerin, 1,2,4-butanetriol, 1,2,6-hexanetriol, 1,2,5-pentanetriol, trimethylolpropane, trimethylolethane, neopentyl glycol, An example is pentaerythritol.

  In the general formula (IV), the polymerizable substance used in the present invention is particularly preferably such that m2 + n2 is equal to the number of residues of the polyol. Specific preferred specific examples of the active energy ray-polymerizable substance represented by the general formula (IV) include, for example, those having the structures shown below. However, the present invention is not limited to these. The substances listed as specific examples are hydrophilic, have a polymerizability, have a high polymerization rate, have a low viscosity per se, and a viscosity of an aqueous solution is a conventionally known compound. The viscosity becomes much lower than that. Moreover, when setting it as the liquid composition or ink of this invention, it can use in combination of 2 or more types from the active energy ray polymeric substance described in this specification.

(Color material)
Since the ink of the present invention contains a coloring material in addition to the above-described components, it becomes a colored active energy ray-curable ink that can cure the ink components. The ink of the present invention having such a configuration makes it possible to form various images by applying it to an ink jet recording method that supports multi-color. The basic elements of the colorant that can be suitably used for the active energy ray-curable ink of the present invention include the above-described polymerizable substance and polymerization initiation essential for making the ink active energy ray-curable. It is necessary to satisfy the compatibility with the agent.

[Aqueous pigment dispersion]
The active energy ray curable liquid composition of the present invention is a colored active energy ray curable ink or an active energy ray curable paint that is cured by irradiation with an active energy ray or the like by containing a coloring material such as a pigment. It will be available. At this time, it is preferable to use an aqueous pigment dispersion in which a pigment is uniformly dispersed in an aqueous medium as a coloring material. As the aqueous pigment dispersion, it is particularly preferable to use an aqueous pigment dispersion in which a pigment is stably dispersed in water by an anionic functional group. For example, water-based gravure inks that are stable in nonionic or anionic systems, pigment dispersions for aqueous writing instruments, pigment dispersions for conventionally known ink jet recording inks, and the like can be applied as they are.

  Examples of pigment dispersions having an anionic dissociation group and dispersed using an alkali-soluble hydrophilic polymer include those disclosed in JP-A-5-247392 and JP-A-8-143802. Can be used. Further, as a pigment dispersion dispersed with a surfactant having an anionic dissociation group, those disclosed in JP-A-8-209048 can be used. In addition, as the pigment dispersion encapsulated with a polymer and dispersed by imparting an anionic dissociative group to the surface, the following can be used. For example, these are disclosed in JP-A-10-140065, JP-A-9-316353, JP-A-9-151342, JP-A-9-104834, and JP-A-9-031360. Further, disclosed in US Pat. No. 5,837,045 and US Pat. No. 5,851,280, in which pigments are dispersed by bonding anionic dissociation groups to the pigment surface by chemical reaction. Such pigment dispersions can be used. In the ink of the present invention, any of the various pigment dispersions described above can be used as the ink coloring material.

  When a pigment is used as the coloring material of the ink of the present invention, it is necessary to use a pigment dispersion in which the pigment is dispersed in a fine particle state in the medium. In particular, a pigment dispersion that can be suitably used for ink needs to have the following basic elements. Specifically, the pigment is dispersed in an aqueous medium, the particle size distribution as a dispersion is in the range of 25 nm to 350 nm in average particle size, and the viscosity of the final ink can be adjusted to a range that does not affect ejection. It will be necessary. The constituent materials that can be used for the pigment dispersion suitable for the present invention are described below.

[Pigment]
Examples of the pigment used for the black ink include carbon black. As carbon black, for example, carbon black produced by a furnace method or a channel method and having the following characteristics is preferable. That is, the primary particle size is 15 μm or more and 40 μm or less, the specific surface area by the BET method is 50 m ² / g or more and 300 m ² / g or less, the DBP oil absorption is 40 ml / 100 g or more and 150 ml / 100 g or less, and the volatile content is 0.5% or more and 10%. % Or less and a pH value of 2 to 9, etc. are preferred. Examples of commercially available products having such characteristics include No. 2300, no. 900, MCF88, No. 33, no. 40, no. 52, MA7, MA8, no. 2200B (Mitsubishi Chemical), Raven 1255 (Columbia), REGAL400R, REGAL330R, REGAL660R, MOGUL L (Cabot), Color Black FW1, Color Black FW18, Color Black S170, Color BlackPurSurP (Made by Degussa).

Examples of the organic pigment having a hue as a process color used in the color ink include those indicated by the following color index (CI) numbers.
C. I. Pigment Yellow 12, 13, 14, 17, 20, 24, 55, 74, 83, 86, 93, 97, 98, 109, 110, 117, 120, 125, 128, 137, 138, 139, 147, 148, 150, 151, 153, 154, 155, 166, 168, 180, 185
C. I. Pigment Orange 16, 36, 43, 51, 55, 59, 61, 71
C. I. Pigment Red 9, 48, 49, 52, 53, 57, 97, 122, 123, 149, 168, 175, 176, 177, 180, 192, 202, 209, 215, 216, 217, 220, 223, 224, 226, 227, 228, 238, 240, 254, 255, 272
C. I. Pigment Violet 19, 23, 29, 30, 37, 40, 50
C. I. Pigment Blue 15, 15: 1, 15: 3, 15: 4, 15: 6, 22, 60, 64
C. I. Pigment Green 7, 36
C. I. Pigment Brown 23, 25, 26

  The average particle diameter of the pigment particles when used in the ink of the present invention is in the range of about 25 nm to 350 nm, preferably in the range of 70 nm to 200 nm. Although this range depends on the use of the printed matter, it is sufficiently smaller than the wavelength of visible light, so that it can be said that the printed matter can be said to be sufficiently transparent if the light scattering is small.

[dye]
When a dye is used as a coloring material, unlike the case of using the above-mentioned pigment, it is difficult to use in a state where there is no fading due to active energy ray irradiation, and there is some fading. For this reason, when applying a dye as the colorant of the ink, it is preferable to use a so-called azo metal-containing dye in which a complex is formed with metal ions, because there is little fading due to light. However, if the level of fading is not a problem, even a general hydrophilic dye can be used at least as an ink.

  As the dye used in the black ink, the following can be suitably used. For example, a monoazo complex or a disazo complex coordinated with a polyvalent metal such as Cr, Cu, Mn, Al, Zn, or Fe. Further, as non-complex azo black dyes, C.I. I. Direct black 17, 19, 51, 154, 174, 195 or the like can be suitably used.

Examples of the dye species having a hue as a process color used in the color ink that can be used in the present invention include those indicated by the following color index (CI) numbers.
C. I. Acid Yellow 11, 17, 23, 25, 29, 42, 49, 61, 71
C. I. Direct yellow 12, 24, 26, 44, 86, 87, 98, 100, 130, 132, 142
C. I. Acid Red 1, 6, 8, 32, 35, 37, 51, 52, 80, 85, 87, 92, 94, 115, 180, 254, 256, 289, 315, 317
C. I. Direct Red 1, 4, 13, 17, 23, 28, 31, 62, 79, 81, 83, 89, 227, 240, 242, 243
C. I. Acid Blue 9, 22, 40, 59, 93, 102, 104, 113, 117, 120, 167, 229, 234, 254
C. I. Direct Blue 6, 22, 25, 71, 78, 86, 90, 106, 199

  A preferable content of the dye in the ink is 0.1% by mass or more and 10% by mass or less based on the total mass of the ink. When the content of the dye is low, for example, it is suitably applied to a so-called density-modulated ink light color ink.

(Reactive diluent component)
The solvent of the active energy ray-curable ink according to the present invention is mainly water, but other than that, a polymerization-reactive low-viscosity monomer can be used. The advantage of using such substances rather than ordinary solvents is that these substances do not remain as plasticizers in the solid after being cured with active energy rays, so that the influence on the solid physical properties is reduced. is there. As reactive diluent solvent components selected for such purposes, those listed below are preferably used. For example, acryloylmorpholine, N-vinyl-2-pyrrolidone, N-vinylformamide, acrylamide, methylenebisacrylamide, monosaccharide monoacrylate, oligoethylene oxide monoacrylate, and dibasic monoacrylate is there.

(Additive)
In the present invention, the active energy ray-curable ink may contain any additive other than the above substances. Examples of such additives include pH adjusters, leveling agents, viscosity modifiers, antioxidants, hindered amine light stabilizers (HALS), humectants, preservatives, fungicides and the like. When used, it is usually contained in the range of 0.1 mass% or more and 5 mass% or less with respect to the whole ink.

(Material composition in clear ink)
The active energy ray-curable liquid composition of the present invention can be used for various purposes as described below as a clear ink by forming a transparent form without containing a colorant as described above. For example, it can be used for applications such as an undercoat for imparting suitability for image printing to a recording medium, or an overcoat for the purpose of surface protection of an image formed with ordinary ink, or for decoration or gloss. . The clear ink (liquid composition) of the present invention may contain a dispersion of colorless pigments or fine particles that are not intended for coloring, depending on the use as described above. By adding a colorless pigment, fine particles, and the like, it is possible to improve various properties such as image quality, fastness, and workability (handling property) of the printed matter in both the undercoat and the overcoat. Prescription conditions for application to such clear ink are not particularly limited, but are preferably as follows. The active energy ray polymerizable substance is preferably contained in the clear ink at a ratio of 10% by mass to 70% by mass. In addition, the active energy ray polymerization initiator of the present invention is contained in an amount of 1 to 10 parts by mass with respect to 100 parts by mass of the polymerizable substance. It is preferable to prepare so as to contain 5 parts by mass.

(Material composition of colorant-containing ink)
When a color material, for example, a pigment is used in the ink of the present invention, the concentration of the pure pigment in the ink is generally 0.3% by mass or more and 10% by mass or less based on the total mass of the ink. The coloring power of the pigment depends on the dispersion state of the pigment particles, but when the concentration of the pure pigment is about 0.3% by mass or more and 1% by mass or less, the range is used as light-colored ink. On the other hand, if it is more than that, it gives a concentration used for general color coloring. The contents of the polymerizable substance and the polymerization initiator are preferably adjusted according to the absorption characteristics of the contained colorant. The content of the polymerizable substance is 1% by mass to 35% by mass, preferably 10% by mass to 20% by mass, based on the total mass of the ink. Although the polymerization initiator depends on the content of the polymerizable substance, it is generally 0.1% by mass or more and 7% by mass or less, preferably 0.3% by mass or more and 5% by mass or less with respect to the total mass of the ink. . The viscosity of the ink of the present invention is linear in a wide range, and when applied to the ink jet recording method, the upper limit is 15 mPa · s. When applied to an ink jet recording method using a recording head having fine high density and high driving frequency nozzles, the upper limit is 10 mPa · s.

(Inkjet recording device)
The ink of the present invention can be suitably applied to an ink jet recording type head, and the use form thereof is an ink storage container storing the ink of the present invention, or an ink for filling the container. Is also effective. In particular, the present invention provides an excellent effect in a bubble jet (registered trademark) type recording head and recording apparatus among ink jet recording methods.

  As for the typical configuration and principle, for example, those performed using the basic principle disclosed in US Pat. Nos. 4,723,129 and 4,740,796 are preferable. . This method can be applied to both a so-called on-demand type and a continuous type. In the case of the on-demand type, at least one that gives a rapid temperature rise exceeding the nucleate boiling corresponding to the recording information to the electrothermal transducer disposed corresponding to the sheet or liquid path holding the ink. One drive signal is applied. This is effective because heat energy is generated in the electrothermal transducer, and the film is boiled on the heat acting surface of the recording head. As a result, the drive signals can be made to correspond one-to-one and bubbles in the ink can be formed. By the growth and contraction of the bubbles, ink is ejected through the ejection openings to form at least one droplet. It is more preferable that the drive signal has a pulse shape, because the bubble growth and contraction is performed immediately and appropriately, and thus ink discharge with particularly excellent responsiveness can be achieved. As this pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further excellent recording can be performed by employing the conditions described in US Pat. No. 4,313,124 of the invention relating to the temperature rise rate of the heat acting surface.

  As a configuration of the recording head, a combination configuration (straight liquid flow path or right-angle liquid flow path) of an ejection port, a liquid path, and an electrothermal transducer as disclosed in each of the above specifications is effective. In addition, the configuration using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose the configuration in which the heat acting portion is arranged in the bent region, is also effectively applied. it can. Further, the air communication type discharge method described in Japanese Patent No. 2968280, Japanese Patent No. 3246949, and Japanese Patent Application Laid-Open No. 11-188870 can also be effectively applied. In addition, the present invention is also effective for a configuration (such as Japanese Patent Application Laid-Open No. 59-123670) in which a common discharge port is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters.

  Furthermore, even when the ink of the present invention is applied to a full-line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, the effect of the present invention is more effectively exhibited. Specifically, the configuration of the recording apparatus of the present invention is a configuration in which the length is satisfied by a combination of a plurality of recording heads as disclosed in the above specification, or a single recording head formed integrally. It can be set as. In addition, it is mounted on the main body of the device so that it can be electrically connected to the main body of the device and supplied with ink from the main body of the device. It may be a cartridge type recording head.

  Further, the recording apparatus of the present invention may be provided with a recovery means for the recording head, preliminary auxiliary means, etc. provided as a configuration of the recording apparatus. Such a configuration is more preferable because the effect of the present invention can be further stabilized. Specific examples of these means are as follows. That is, a capping unit for the recording head, a cleaning unit, a pressurizing or sucking unit, a preheating unit using an electrothermal converter or a heating element different from this, or a combination thereof, and a preliminary unit performing ejection different from recording. It is a discharge mode.

  An example of the recording apparatus of the present invention is specifically shown using the schematic diagram of the front of the printer in FIG. Such a recording apparatus includes an ink storage unit 1 that stores active energy ray-curable ink, a head unit 2 that performs recording, a lamp unit 3 that performs ultraviolet irradiation for curing, a drive unit 4 that drives the head unit and the lamp unit, A paper discharge unit 5 for conveying a recording medium is provided. The head unit 2 uses a multi-head in which a large number of heads are arranged. The illustrated recording apparatus includes a wiping unit, a capping unit, a paper feeding unit, and a drive motor unit (not shown) in addition to these.

  In FIG. 1, the head portion 2 has nozzle portions for discharging active energy ray-curable ink arranged symmetrically for each color. Then, the head unit 2 and the lamp unit 3 are integrally scanned left and right, and after the aqueous active energy ray-curable ink composition is applied to the recording medium, ultraviolet irradiation is immediately performed (about the details of the lamp). Will be described later).

  Further, in the illustrated example, the ink container 1 constituting the ink cartridge has four colors of black (Bk), cyan (C), magenta (M), and yellow (Y). However, the present invention is not limited to this, and, for example, six colors to which light cyan (LC) or light magenta (LM) is added may be arranged in order to obtain a higher-definition recorded image. As the ink storage unit for storing the active energy ray-curable ink of the present invention, an ink storage unit that can block light is used. As the configuration of the recording apparatus of the present invention, in addition to the recording system described above, a lamp is disposed on the front surface of the paper discharge unit, a paper feed / discharge is wound around a rotating drum, The thing which provided the drying part separately can be selected suitably.

(UV irradiation lamp)
Hereinafter, an ultraviolet irradiation lamp (light source) that is particularly preferably used in curing the active energy ray-curable ink of the present invention will be described. However, the active energy ray irradiation unit used in the present invention is limited to the ultraviolet lamp. Is not to be done. The ultraviolet irradiation lamp is preferably a so-called low-pressure mercury lamp, high-pressure mercury lamp, mercury lamp coated with a phosphor, or the like in which the vapor pressure of mercury is 1 Pa to 10 Pa during lighting. The emission spectrum of these mercury lamps in the ultraviolet region is in the range of wavelength 184 nm or more and wavelength 450 nm or less, and is suitable for efficiently reacting the photopolymerizable substance in black or colored ink. In addition, it is suitable for mounting a power source in a printer because a small power source can be used. As the mercury lamp, for example, a metal halide lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a xenon flash lamp, a deep UV lamp, a lamp that uses a microwave to excite the mercury lamp from the outside without electrode, a UV laser, and the like are in practical use. Since these lamps include the above-mentioned range as the emission wavelength region, they are basically applicable as long as power supply size, input intensity, lamp shape, and the like are allowed. The irradiation intensity of ultraviolet light is preferably 500 mW / cm ² or more 5,000 MW / cm ² or less in wavelength region effective to cure. If the irradiation intensity is weak, the effect of the present invention cannot be obtained sufficiently. On the other hand, if the irradiation intensity is too high, the recording medium may be damaged or the color material may be faded.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. The present invention is not limited by the following examples unless it exceeds the gist. In the text, “part” or “%” is based on mass unless otherwise specified.

(Examples 1-8 and Examples 9-16)
The components shown in Table 1 and Table 2 below are mixed, sufficiently stirred and dissolved, and then subjected to pressure filtration with a 0.50 μm filter, and the non-aqueous liquid compositions of Examples 1 to 8, and The aqueous liquid compositions of Examples 9-16 were prepared respectively.

(Evaluation of film strength of liquid composition)
Using each liquid composition shown in Table 1 and Table 2, the film strength was evaluated as follows. Using a bar coater on a commercially available PET (polyethylene terephthalate) film, the non-aqueous liquid compositions of Examples 1 to 8 and the aqueous liquid compositions of Examples 9 to 16 were each 20 g / m ² and Coated so that The PET film obtained by coating each of the liquid compositions was applied to a UV irradiation apparatus. As a UV lamp, FUSION UV Systems Inc. A UV curable evaluation apparatus model LH6B manufactured by the company was used. The irradiation intensity on the irradiated surface was 1,500 mW / cm ² . The film conveyance speed was 0.2 m / s. The strength of the film thus formed was measured by a method based on JIS using a commercially available pencil hardness tester. The obtained measurement results are summarized in Tables 3 and 4. As a result, as shown in Tables 3 and 4, a pencil hardness with no practical problem was obtained regardless of whether a non-aqueous liquid composition or an aqueous liquid composition was used.

(Examples 17-21 and Comparative Examples 1-3)
First, a cyan pigment dispersion was prepared as follows. Pigment Blue 15: 3 was used as a pigment, and a random polymer of styrene / acrylic acid / ethyl acrylate (average molecular weight: 3,500, acid value: 150) was used as a dispersant. These components were dispersed by a bead mill, and finally a cyan pigment dispersion having a solid content of 10% by mass and a pigment / binder ratio (mass ratio) of P / B = 3: 1 was obtained. About the obtained pigment dispersion, the average particle diameter of the pigment measured by a laser light scattering type particle diameter measuring apparatus was 120 nm. Next, each component shown in Table 5 below containing the cyan pigment dispersion obtained above was mixed, sufficiently stirred and dissolved, and then filtered under pressure through a 0.50 μm filter. 21 inks and inks of Comparative Examples 1 to 3 were prepared. The pH of the ink was adjusted using a 0.2 N aqueous sodium hydroxide solution so that the pH was finally 8.5. In the inks of Comparative Examples 1 to 3, the following Comparative Compound 1 or Comparative Compound 2, which is another polymerization initiator that can be used in combination with the novel active energy ray polymerization initiator of the present invention, was used as a component of the ink. .

(Evaluation of ink curing performance)
Using the ink shown in Table 5, the curing performance was evaluated as follows.

[Evaluation inkjet recording apparatus]
An on-demand type ink jet recording apparatus Pixus 550i (manufactured by Canon Inc.) that discharges ink by applying thermal energy corresponding to the recording signal to the ink has been modified to have the same configuration as that shown in FIG. . Specifically, a UV lamp that excites a mercury lamp with no electrode from the outside using a microwave is mounted adjacent to the recording head unit. The irradiation intensity on the irradiated surface was 1,500 mW / cm ² . This printer was used for evaluation according to the evaluation methods and evaluation criteria described in (1) and (2) below. The evaluation results are summarized in Table 6.

(1) Fixability Using each of the cyan inks of Examples 17 to 21 and Comparative Examples 1 to 3 and the inkjet recording apparatus, 100% solid printing was performed on offset paper OK Kinto made by Mitsubishi Paper Industries. In the present invention, a mode in which an area of one pixel of an image formed at 600 × 600 dpi is completely filled with about 5 pl of ink dots is called 100% solid printing. 10 seconds after printing, the sample was placed on the recording medium on which the printing was performed, and the paper was pulled with a load of 40 g / cm ^{2 on} the recording surface. It was visually observed whether or not stains were caused by rubbing of the printed part on the non-printed part (white background part) and the Sylbon paper of the recording medium, and evaluated according to the following criteria.
A: Almost no dirt due to rubbing B: Some dirt due to rubbing is slightly seen C: Some dirt due to rubbing is noticeable

(2) Marker resistance Using the cyan inks of Examples 17 to 21 and Comparative Examples 1 to 3 and the inkjet recording apparatus, 12 point characters were printed on Canon PPC paper. 1 minute after printing, the above-mentioned sample was marked once with a normal writing pressure using a fluorescent pen spotlight yellow manufactured by Pilot, and visually observed for the presence or absence of disorder of the characters, and evaluated according to the following criteria. .
A: Character disorder due to marker hardly occurs B: Character disorder due to marker slightly occurs C: Character disorder due to marker significantly occurs

  As described above, according to the present invention, the liquid composition has good curability, has practical curing performance even when it contains a colorant such as a pigment, and the cured product has excellent fixability and marker resistance. And ink can be provided. Further, the above-described embodiments are examples given to show the basic configuration of the present invention, and it goes without saying that, for example, ink having the same performance can be provided even when a dye is used as a coloring material.

It is a schematic front view which shows typically an example of the suitable inkjet recording device used for this invention.

Explanation of symbols

1: Ink storage unit 2 for storing the active energy ray-curable ink of the present invention 2: Head unit for recording with an ink storage unit 3: Lamp unit for ultraviolet irradiation for curing 4: Head unit and lamp unit Drive unit 5 for driving: paper discharge unit for conveying a recording medium to be recorded

Claims (15)

An active energy ray polymerization initiator represented by the following general formula (I):

[In the general formula (I), R ₁ represents — (A) —COOM or — (A) —SO ₃ M (wherein (A) represents an oxyalkylene group which may be a single bond or branched; Represents any one of a hydrogen atom, an alkali metal, an alkaline earth metal and ammonium), and R ₂ and R ₃ each independently represent any one of a hydrogen atom, an alkyl group, an alkenyl group and a benzyl group. , R ₄ , R ₅ , R ₆ and R ₇ are independently of each other an alkyl group, a benzyl group or a phenyl group, or R ₄ and R ₅ and / or R ₆ and R ₇ are respectively A cyclic functional group is formed. ] An active energy ray-curable liquid composition comprising at least an active energy ray polymerization initiator represented by the following general formula (I) and a polymerizable substance that undergoes radical polymerization by active energy rays.

[In the general formula (I), R ₁ represents — (A) —COOM or — (A) —SO ₃ M (wherein (A) represents an oxyalkylene group which may be a single bond or branched; Represents any one of a hydrogen atom, an alkali metal, an alkaline earth metal and ammonium), and R ₂ and R ₃ each independently represent any one of a hydrogen atom, an alkyl group, an alkenyl group and a benzyl group. , R ₄ , R ₅ , R ₆ and R ₇ are independently of each other an alkyl group, a benzyl group or a phenyl group, or R ₄ and R ₅ and / or R ₆ and R ₇ are respectively A cyclic functional group is formed. ] The active energy ray-curable liquid composition according to claim 2, further comprising an active energy ray polymerization initiator represented by the following general formula (II).

[In general formula (II), R ₈ represents an alkyl group or a phenyl group, R ₉ represents an alkoxy group or a phenyl group, and R ₁₀ represents the following general formula (III).

In the general formula (III), R ₁₁ represents — [CH ₂ ] _x1 — (x1 is 0 or 1) or a phenylene group, m1 represents an integer of 0 to 10, and n1 represents 0 or 1. R ₁₂ represents any one selected from a hydrogen atom, a sulfone group, a carboxyl group, a hydroxyl group, and salts thereof. ]   The active energy ray-curable liquid composition according to claim 2 or 3, further comprising water.   The active energy ray-curable liquid composition according to claim 2, wherein the polymerizable substance is a hydrophilic polymerizable substance.   An active energy ray-curable ink comprising at least the active energy ray polymerization initiator according to claim 1, a polymerizable substance that undergoes radical polymerization by active energy rays, and a coloring material.   The active energy ray-curable ink according to claim 6, further comprising the active energy ray polymerization initiator according to claim 3.   The active energy ray-curable ink according to claim 6, which is an inkjet recording ink.   A step of discharging the ink for inkjet recording according to claim 8 onto a recording medium, and a step of irradiating the recording medium to which the ink is applied with active energy rays to cure the ink. An inkjet recording method.   10. The ink jet recording method according to claim 9, wherein in the step of ejecting the ink for ink jet recording onto the recording medium, the ink is ejected onto the recording medium by applying thermal energy to the ink. .   A recorded image formed by the inkjet recording method according to claim 9.   An ink cartridge comprising an ink storage portion in which the ink for ink jet recording according to claim 8 is stored.   A recording unit comprising: an ink storage portion storing the ink for ink jet recording according to claim 8; and a recording head for discharging the ink.   An ink jet recording comprising: means for applying the ink for ink jet recording according to claim 8 on a recording medium; and means for irradiating active energy rays to the ink applied to the recording medium. apparatus. Means for irradiating the active energy ray, an ultraviolet radiation lamp having the following light source wavelength 450 nm, the irradiation intensity of the ultraviolet rays, to claim 14 which is 500 mW / cm ² or more 5,000 MW / cm ² or less in the range The ink jet recording apparatus described.

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