JP2011068803A - Liquid composition, inkjet recording method, inkjet recording device, and recorded image - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-speed rapidly curable liquid composition excellent in the time storage stability and the discharge stability and suitable for high-speed recording using inkjet. <P>SOLUTION: The liquid composition contains an amide compound, a vinyl aryl compound, and photoinitiator, and is cured by irradiation of an active energy ray, wherein the amide compound has a specific structure, and the vinyl aryl compound has a specific structure. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid composition, an ink jet recording method, an ink jet recording apparatus, and a recorded image.

  Conventionally, as a technique for image formation, a photocurable liquid composition and an active energy ray irradiation source are used, and the liquid composition (ink) is irradiated with active energy rays on an image substrate such as paper. There is known a method of obtaining an image by forming a cured film of the ink.

  As one of the liquid compositions used in this case, there is known a type that makes an active energy ray-curable resin composition itself containing a coloring material water-based. When a very common anionic dye or anionic dispersion pigment is used as a coloring material of this type of liquid composition, there are the following problems. That is, as the carboxylic acid is generated by hydrolysis of the ester group in the resin component, the pH of the liquid composition is lowered to the acidic range, and the dye that was present stably is precipitated, or the pigment dispersion is aggregated and settled As a result, the stability is impaired, and there are cases where the formation of a suitable image is hindered. On the other hand, the present applicant has proposed to use a polymerizable substance having an amide structure adjacent to the crosslinkable group of the curable substance (see Patent Document 1). By adopting such a configuration, the amount of carboxylic acid generated by hydrolysis can be suppressed, and high stability can be imparted to the liquid composition containing the color material regardless of the type of dispersion or color material used. Is possible.

  However, in recent years, in such image forming technology, the diversity according to the individual needs of customers and the necessity of high image quality have been dramatically increased. Accordingly, in the liquid composition of the type that makes the active energy ray-curable resin composition itself aqueous, it is extremely important to exhibit high curing characteristics in various recording media, which is higher than before. Technology that imparts curing properties is indispensable.

  Examples of techniques for imparting high curing characteristics by active energy ray curing include the following. The technique disclosed in Patent Document 2 is a technique in which an unsaturated compound having an electron accepting group such as maleic acid diester and an unsaturated compound having an electron donating group such as aryloxystyrene are polymerized by irradiating with ultraviolet rays. It is. In addition, the technology disclosed in Patent Document 3 improves the curing characteristics by copolymerizing a maleimide derivative and a compound such as vinyl ether in an active energy ray-curable inkjet ink, and reduces the amount of photoinitiator used. It is something that is going to be reduced.

JP 2005-307198 A Japanese Patent Laid-Open No. 06-298817 JP 2003-213171 A

  However, each of the conventional techniques described above has the following problems. That is, the technique disclosed in Patent Document 2 is a technique for a special system that does not use a photopolymerization initiator, and there is no mention of curing characteristics as an aqueous liquid. In the technique disclosed in Patent Document 3, the effect of improving the curing characteristics is not sufficient depending on the system to be applied, and no mention is made of the curing characteristics in aqueous ink.

  Accordingly, an object of the present invention is an aqueous liquid composition that is cured by irradiation with active energy rays, and can be suitably used as an ink containing a coloring material, and further has excellent stability and high curing characteristics. It is in providing the liquid composition which has this. Another object of the present invention is to provide an ink jet recording method, an ink jet recording apparatus, and a recorded image using the liquid composition.

（一般式（１）中、Ｒ₁はｎ（＝ｎ１＋ｎ２）価の有機基、Ｒ₂はそれぞれ独立に水素原子又は１価の有機基、Ｘは二重結合を有する２価の有機基、Ｙはアルカリ金属又は有機塩基である。ｎ１は１以上の整数であり、ｎ２は０以上の整数であり、かつ、ｎ（＝ｎ１＋ｎ２）は２以上の整数である。）

（一般式（２）中、Ｒ₃はｎ価の有機基、Ｒ₄及びＲ₅はそれぞれ独立に水素原子又は１価の有機基であり、ｎは１以上の整数である。）

（一般式（３）中の、Ｒ₁₂はｍ価の有機基、Ｒ₁₃は水素原子又は１価の有機基であり、ｍは１以上の整数であり、かつ、ｍ＋ｎ≧３である。） The above object is achieved by the present invention described below. That is, the present invention is an aqueous liquid composition comprising an amide compound, a vinylaryl compound, and a photopolymerization initiator and cured by irradiation with active energy rays, wherein the amide compound is: Including at least one amide compound represented by the general formula (1) and the following general formula (2), wherein the vinylaryl compound includes a vinylaryl compound represented by the following general formula (3): Liquid composition.

(In general formula (1), R ₁ is an n (= n1 + n2) valent organic group, R ₂ is independently a hydrogen atom or a monovalent organic group, X is a divalent organic group having a double bond, Y Is an alkali metal or an organic base, n1 is an integer of 1 or more, n2 is an integer of 0 or more, and n (= n1 + n2) is an integer of 2 or more.)

(In general formula (2), R ₃ is an n-valent organic group, R ₄ and R ₅ are each independently a hydrogen atom or a monovalent organic group, and n is an integer of 1 or more.)

(In general formula (3), R ₁₂ is an m-valent organic group, R ₁₃ is a hydrogen atom or a monovalent organic group, m is an integer of 1 or more, and m + n ≧ 3.)

  According to the present invention, it is an aqueous liquid composition that is cured by irradiation with active energy rays, and can be suitably used as an ink containing a coloring material, and further has excellent stability and high curing characteristics. A liquid composition can be provided. Further, according to the present invention, an ink jet recording method, an ink jet recording apparatus, and a recorded image using the liquid composition can be provided.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments.
In view of the above-described object, the present inventors, in the process of making various studies, at least one of amide compounds represented by the following general formulas (1) and (2) and the following general formula (3): A liquid composition comprising the represented vinylaryl compound and a photopolymerization initiator was prepared. Then, the liquid composition was used as a water-based ink cured by an active energy ray in a form containing a coloring material, and the ink was evaluated. As a result, it has been found that the liquid composition having such a configuration is excellent in curing performance such as crosslinking degree and adhesiveness even when irradiated with low energy active energy rays. Furthermore, it satisfies the level of low viscosity required for ink-jet liquid compositions, and is excellent in storage stability over time and ejection stability (hereinafter simply referred to as stability) required for aqueous inks. As a result, the present invention has been accomplished.

（一般式（１）中、Ｒ₁はｎ（＝ｎ１＋ｎ２）価の有機基、Ｒ₂はそれぞれ独立に水素原子又は１価の有機基、Ｘは二重結合を有する２価の有機基、Ｙはアルカリ金属又は有機塩基である。ｎ１は１以上の整数であり、ｎ２は０以上の整数であり、かつ、ｎ（＝ｎ１＋ｎ２）は２以上の整数である。）

（一般式（２）中、Ｒ₃はｎ価の有機基、Ｒ₄及びＲ₅はそれぞれ独立に水素原子又は１価の有機基であり、ｎは１以上の整数である。）

（一般式（３）中の、Ｒ₁₂はｍ価の有機基、Ｒ₁₃は水素原子又は１価の有機基であり、ｍは１以上の整数であり、かつ、ｍ＋ｎ≧３である。）

(In general formula (1), R ₁ is an n (= n1 + n2) valent organic group, R ₂ is independently a hydrogen atom or a monovalent organic group, X is a divalent organic group having a double bond, Y Is an alkali metal or an organic base, n1 is an integer of 1 or more, n2 is an integer of 0 or more, and n (= n1 + n2) is an integer of 2 or more.)

(In general formula (2), R ₃ is an n-valent organic group, R ₄ and R ₅ are each independently a hydrogen atom or a monovalent organic group, and n is an integer of 1 or more.)

(In general formula (3), R ₁₂ is an m-valent organic group, R ₁₃ is a hydrogen atom or a monovalent organic group, m is an integer of 1 or more, and m + n ≧ 3.)

-X- in the general formula (1) is a polymerizable group, and any structure may be used as long as it includes an amic acid or amidate structure. From the viewpoint of reactivity, It is preferably any one selected from the formulas (A), (B), (C), and (D).

  The present inventors presume the reason why the liquid composition of the present invention having the above-described configuration can achieve excellent results in both curing performance and stability as described above. First, the mechanism by which the curing performance of the liquid composition of the present invention is remarkably improved is estimated as follows. The amide compounds represented by the general formulas (1) and (2), which are polymerizable substances used in the present invention, have an electron withdrawing group for a vinyl group. The amide compound alone has less radical polymerization reactivity than a conventional compound having an acrylic group. However, since the vinyl aryl compound represented by the general formula (3), which is another polymerizable substance, has an electron donating group, the amide compound having an electron withdrawing group has a weak charge transfer complex with this electron donating group. Form. And when this is irradiated with active energy rays such as ultraviolet rays, radicals are generated, which act as an aqueous photopolymerization initiator. It is thought that this radical functions in addition to the aqueous photopolymerization initiator originally contained in the liquid composition, so that the amide compound and vinylaryl compound in the liquid composition are effectively copolymerized. ing.

  The present inventors presume the mechanism by which the storage stability over time of the liquid composition of the present invention is remarkably improved as follows. The amide compound and the vinyl aryl compound used in the present invention are less affected by hydrolysis of ester groups than aqueous hydrophilic polymerizable substances having a conventional acrylic ester structure in an aqueous liquid. The amount of acid is very low. Therefore, the pH drop to the acidic region of the liquid composition is suppressed, and dyes dissolved in water by anionic groups and pigment dispersions in which pigments are dispersed in water by anionic groups are stably dissolved. Or can be dispersed. As a result, it is presumed that the liquid composition of the present invention has excellent storage stability with time and improved discharge stability.

  As a main application example of the liquid composition concerning this invention, inkjet printing is mentioned. As the active energy ray used in the present invention, ultraviolet rays (UV), electron beams, and the like can be used. In the following, a liquid composition of a type that is radically polymerized and cured by ultraviolet rays will be described as a representative example. To proceed. However, this does not limit the scope of application of the present invention. In particular, the liquid composition (ink) of the present invention exhibits a remarkable effect on a recording medium such as plain paper, which has a liquid absorption property but it is difficult to improve the color development and scratch resistance of images. There is expected. The effect of the present invention is not only for plain paper, but also for recording media with less liquid absorbency, such as offset printing paper, foam paper, cardboard paper, and non-liquid-absorbing printing substrates made of metal or plastic. Is also expected. As in the present invention, in the presence of moisture, how the curing of the polymerizable substance that undergoes radical polymerization by active energy rays proceeds is important as a problem of the radical reaction rate. According to the study by the present inventors, it has not been observed that the polymerization in water in a system in which no coloring material is present is particularly slow compared with the case of a solventless system.

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

(Polymerizable material)
Since the liquid composition of the present invention must be stably present, the polymerizable substance used in the present invention is preferably hydrophilic. The polymerizable substance as used in the present invention is hydrophilic, meaning that the polymerizable substance is soluble in water at room temperature or soluble in an organic solvent miscible with water, and the solvent is It means that it is soluble in water at room temperature.

  The compound having any one of the amide groups represented by the general formulas (1) and (2), which is one of the polymerizable substances used in the liquid composition of the present invention, has the following structure from the viewpoint of hydrophilicity. It is more preferable to have Divalent organic compounds having a hydrophilic linking group selected from the group consisting of a carboxyl group, a sulfonic acid group, a phosphoric acid group, an amino group, a hydroxyl group, and salts thereof, an amide group, an amide linking group, an ether linking group, and a sulfonic group. It is good to have a linking group containing at least one group.

  Similarly, the vinyl aryl compound represented by formula (3), which is one of the polymerizable substances used in the liquid composition of the present invention, is more preferably one having the following structure from the viewpoint of hydrophilicity. Hydrophilicity selected from the group consisting of carboxyl group, sulfonic acid group, phosphoric acid group, amino group, hydroxyl group and salts thereof, amide group, amide bonding group, ether bonding group, urethane bonding group, sulfone bonding group, carbonyl bonding group It is preferable to have a linking group containing at least one organic group having a linking group.

  As a more preferable form, it is preferable that the amide compound and the vinyl aryl compound are each dissolved in water at 1% by mass uniformly at room temperature, and more preferably 5% by mass or more. It is preferable that it has hydrophilicity.

  In the present invention, the number of polymerizable functional groups in each polymerizable substance that is polymerized by the active energy ray used is preferably in the range of 2 to 6 from the viewpoint of the curing performance and low viscosity of the liquid composition. The range of 3 to 4 is preferable. The higher the number of polymerized functional groups in the hydrophilic polymerizable material, the better the curing performance. However, as the number of functional groups increases, the viscosity of the liquid composition increases and is compatible with high-density nozzles for inkjet recording systems. It is difficult to obtain a liquid composition with good flow characteristics. Further, if the polymerizable substance has one polymerization functional group, the polymerization rate is slow, and the degree of cross-linking of the cured product is remarkably reduced, so that it is not preferable as a material used in the liquid composition of the present invention. The polymerizable substance used in the present invention may be a monofunctional monomer having a polymerization functional group of 1. In this case, an active energy ray polymerizable substance having two or more polymerizable functional groups is used in combination. It is particularly preferable to do this. For this reason, in the present invention, polymerization of at least one of the polymerizable substances represented by the general formulas (1) and (2) contained in the liquid composition and the polymerizable substance represented by the general formula (3) is performed. The total number of functional groups (m + n) is adjusted to be 3 or more.

  Hereinafter, some particularly preferred specific examples of the amide compound represented by the general formulas (1) and (2) and the vinylaryl compound represented by the general formula (3) are given. Of course, the scope of the present invention is not limited to these. The position where the maleimide group enters the end is not limited to the structure exemplified in each document, and may be present at any position.

"Specific examples of amide compounds"
<Specific Example of Amide Compound Represented by General Formula (2)>
Exemplified compounds 1 to 10 described in JP2007-119449A

<Specific Example of Amide Compound Represented by General Formula (1)>

"Specific examples of vinyl aryl compounds"
<Specific Example of Vinyl Aryl Compound Represented by General Formula (3)>

  Any conventionally known method can be used as a method for synthesizing the amide compound and vinylaryl compound as described above used in the present invention. As an example, a method for synthesizing an amide compound is described in, for example, Japanese Patent Application Laid-Open No. 2007-119449. Moreover, the synthesis method of a vinyl aryl compound is described in Unexamined-Japanese-Patent No. 2000-239192, for example.

  In the present invention, the mixing ratio of the amide compound and the vinylaryl compound contained in the liquid composition is preferably in the range of 5:95 to 95: 5, more preferably 1:10 to 10 in terms of mass ratio. Is more preferably in the range of 1: 1. Further, the total content of the amide compound and the vinylaryl compound in the liquid composition is preferably in the range of 1.0% by mass or more and 80.0% by mass or less based on the total mass of the liquid composition, and more preferably 5 More preferably, it is in the range of 0.0 mass% or more and 60.0 mass% or less.

(Photopolymerization initiator)
The photopolymerization initiator used in the present invention is preferably hydrophilic. In the present invention, “the polymerization initiator is hydrophilic” means that the polymerization initiator is soluble in an organic solvent miscible with water, the solvent is water-soluble, and the polymerization initiator itself is not. Even if it is water-soluble, it means that it has been treated in a form that can be emulsified in water, or that it is water-soluble.

  The hydrophilic photopolymerization initiator used in the present invention is preferably a photoradical generator that generates radicals by active energy rays, and examples include compounds represented by the following general formulas (5) to (9). Can be mentioned.

（一般式（５）中、Ｒ₁₃は、炭素数１乃至５のアルキル基、フェニル基（該フェニル基は非置換、又は、ハロゲン原子、炭素数１乃至５のアルキル基、炭素数１乃至５のアルキルオキシ基、スルホン酸基、カルボキシル基、ヒドロキシル基及びそれらの塩；−ＳＯ₃ ^-Ｍ⁺、−ＣＯ₂ ^-Ｍ⁺、−Ｏ^-Ｍ⁺、下記原子団（Ｅ）から選ばれる任意の置換基により１乃至４回置換されている）を表す。Ｒ₁₄は、炭素数１乃至５のアルキルオキシ基、又はフェニル基（該フェニル基は非置換、又はハロゲン原子、炭素数１乃至５のアルキル基、炭素数１乃至５のアルキルオキシ基から選ばれる任意の置換基により１乃至４回置換されている）を表す。Ｒ₁₅は下記原子団（Ｅ）を表す。）

(In the general formula (5), R ₁₃ is an alkyl group having 1 to 5 carbon atoms and a phenyl group (the phenyl group is unsubstituted, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or 1 to 5 carbon atoms). alkyloxy group, a sulfonic acid group, a carboxyl group, a hydroxyl group and salts ^{_{thereof; -SO 3 - M +, -CO}} 2 - M +, -O - M +, any selected from the following atomic groups (E) R ₁₄ represents an alkyloxy group having 1 to 5 carbon atoms or a phenyl group (the phenyl group is unsubstituted, a halogen atom, or having 1 to 5 carbon atoms). R ₁₅ represents the following atomic group (E): an alkyl group and an arbitrary substituent selected from an alkyloxy group having 1 to 5 carbon atoms).

（原子団（Ｅ）中、Ｒ₁₆は、−[ＣＨ₂]_X2−（Ｘ２は０又は１）、又は置換若しくは非置換のフェニレン基を表す。Ｒ₁₇は、水素原子、又はスルホン酸基、カルボキシル基、ヒドロキシル基及びそれらの塩；−ＳＯ₃ ^-Ｍ⁺、−ＣＯ₂ ^-Ｍ⁺、−Ｏ^-Ｍ⁺を表す。ｋは０乃至１０の整数、ｌ（エル）は０又は１を表す。また、上記Ｍ⁺はそれぞれ独立に、水素イオン、アルカリ金属イオン、アルカリ土類金属イオンの当量、又はＨＮＲ₁₈Ｒ₁₉Ｒ₂₀で表されるアンモニウムイオンを表す。該アンモニウムイオン中、Ｒ₁₈、Ｒ₁₉、Ｒ₂₀はそれぞれ独立に水素原子、炭素数１乃至５のアルキル基、モノヒドロキシル置換炭素数１乃至５のアルキル基、又はモノヒドロキシル置換フェニル基を表す。）

(In the atomic group (E), R ₁₆ represents — [CH ₂ ] _{X 2} — (X 2 is 0 or 1), or a substituted or unsubstituted phenylene group. R ₁₇ represents a hydrogen atom or a sulfonic acid group, carboxyl group, hydroxyl group and salts ^{_{thereof; -SO 3 - M +, -CO}} 2 - M +, -O - .k representing the M ⁺ is 0 to 10 integer, l (El) represents 0 or 1 In addition, each M ⁺ independently represents an equivalent of a hydrogen ion, an alkali metal ion, an alkaline earth metal ion, or an ammonium ion represented by HNR ₁₈ R ₁₉ R ₂₀ , wherein R ₁₈ , R ₁₉ and R ₂₀ each independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a monohydroxyl-substituted alkyl group having 1 to 5 carbon atoms, or a monohydroxyl-substituted phenyl group.

（一般式（６）中、ｍ３は１以上の整数を表し、ｎ３は０以上の整数を表し、ｍ３＋ｎ３は１乃至８の整数を表す。）

(In general formula (6), m3 represents an integer of 1 or more, n3 represents an integer of 0 or more, and m3 + n3 represents an integer of 1 to 8.)

（一般式（７）中、Ｒ₂₁及びＲ₂₂はそれぞれ独立に、水素原子又は炭素数１乃至５のアルキル基を表し、ｍ４は５乃至１０の整数を表す。）

(In general formula (7), R ₂₁ and R ₂₂ each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and m4 represents an integer of 5 to 10).

（一般式（８）中、Ｒ₂₃及びＲ₂₄はそれぞれ独立に、水素原子又は炭素数１乃至５のアルキル基を表し、Ｒ₂₅は、−(ＣＨ₂)_x−（ｘは０又は１）、−Ｏ−(ＣＨ₂)_y−（ｙは１又は２）又はフェニレン基を表し、Ｍは水素原子又はアルカリ金属を表す。）

(In General Formula (8), R ₂₃ and R ₂₄ each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ₂₅ represents — (CH ₂ ) _x — (x is 0 or 1). , —O— (CH ₂ ) _y — (y is 1 or 2) or a phenylene group, and M represents a hydrogen atom or an alkali metal.

（一般式（９）中、Ｒ₂₆及びＲ₂₇はそれぞれ独立に、水素原子又は炭素数１乃至５のアルキル基を表し、Ｍは水素原子又はアルカリ金属を表す。）

(In general formula (9), R ₂₆ and R ₂₇ each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and M represents a hydrogen atom or an alkali metal.)

Further, the alkyl group and phenyl group of R ₁₃ and the phenylene group of R _{16 in} the general formula (5) may have a substituent. Examples of such substituents include the following. Specifically, for example, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkyloxy group having 1 to 5 carbon atoms, a group represented by the above atomic group (E), a sulfonic acid group, a carboxyl group, a hydroxyl group And salts of sulfonic acid group, carboxyl group and hydroxyl group (—SO ₃ M, —CO ₂ M, —OM). Particularly preferred R ₁₃ is a phenyl group having an alkyl group having 1 to 5 carbon atoms as a substituent. M is independently a hydrogen atom, an alkali metal, an alkaline earth metal, or ammonium represented by HNR ₂₈ R ₂₉ R ₃₀ (R ₂₈ , R ₂₉ , R ₃₀ are each independently a hydrogen atom, carbon number, Represents a 1 to 5 alkyl group, a monohydroxyl-substituted alkyl group having 1 to 5 carbon atoms, or a monohydroxyl-substituted phenyl group.

Examples of the salt of R ₁₃ in the general formula (5) include —SO ₃ M, —CO ₂ M, and OM. Such M is independently a hydrogen atom, an alkali metal, an alkaline earth metal, or ammonium represented by HNR ₃₁ R ₃₂ R ₃₃ (R ₃₁ , R ₃₂ , R ₃₃ are each independently a hydrogen atom, carbon number 1 Or a monohydroxyl-substituted alkyl group having 1 to 5 carbon atoms, or a monohydroxyl-substituted phenyl group.

The alkyloxy group and phenyl group of R ₁₄ in the general formula (5) may have a substituent, such as a halogen atom, an alkyl group having 1 to 5 carbon atoms, or 1 to 5 carbon atoms. Of the alkyloxy group. Particularly preferred R ₁₄ is an alkyloxy group, and among them, —OC ₂ H ₅ and —OC (CH ₃ ) ₃ .

The alkyl groups of R _{21 to} R ₂₄ and R _{26 to} R _{27 in} the general formulas (7) to (9) may have a substituent. Examples of such substituents include the following. Specific examples include a halogen atom, a sulfonic acid group, a carboxyl group, a hydroxyl group and a sulfonic acid group, a carboxyl group, and a hydroxyl group salt (—SO ₃ M, —CO ₂ M, —OM). M is independently a hydrogen atom, an alkali metal, an alkaline earth metal, or ammonium represented by HNR ₃₄ R ₃₅ R ₃₆ (R ₃₄ , R ₃₅ , R ₃₆ are each independently a hydrogen atom, carbon number 1 Or a monohydroxyl-substituted alkyl group having 1 to 5 carbon atoms, or a monohydroxyl-substituted phenyl group.

  Among these, the hydrophilic acylphosphine oxide compound represented by the general formula (5) is particularly preferable. As these photopolymerization initiators, for example, Exemplified compounds 25 to 29 described in JP-A-2007-119449 can be used. Of course, the photopolymerization initiator used in the present invention is not limited to these.

  In the present invention, when a thioxanthone hydrophilic polymerization initiator or the like is used as the hydrophilic photopolymerization initiator, it is preferable to add a hydrogen donor. Examples of the hydrogen donor that can be used in the present invention include triethanolamine and monoethanolamine.

  In the present invention, two or more kinds of photopolymerization initiators can be used in combination. By using two or more types of photopolymerization initiators, it can be expected that light of a wavelength that cannot be effectively used by one type of photopolymerization initiator will be used to promote further generation of radicals and improve curing characteristics. .

(solvent)
As the solvent used in the liquid composition according to the present invention, water is preferably used. In the present invention, a water-soluble organic solvent can be used in combination with water for the purpose of assisting in uniformly dissolving the polymerizable substance, the photopolymerization initiator, and the like.

  As the water-soluble organic solvent, any conventionally known solvents can be used as long as they are soluble in water and can satisfy other ink jet characteristics. However, from the viewpoints of environmental impact, work odor, safety, etc., a composition in which 50.0% by mass or more in all solvents is water is preferable, and in particular, 90.0% by mass or more in all solvents is water. Such a configuration is extremely preferable.

  Examples of water-soluble organic solvents that can be used in the present invention are listed below. For example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monoallyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl Ethers, glycol ethers such as dipropylene glycol monomethyl ether, polyhydric alcohols such as glycerin, water-soluble amide compounds such as 2-pyrrolidone, and the like.

(Liquid composition containing no coloring material)
Moreover, the liquid composition concerning this invention can be used with transparency, without making it contain the coloring material which is mentioned later. In particular, when prepared so as to have ink jet recording characteristics, an active energy ray-curable transparent liquid composition for ink jet can be obtained. If the liquid composition in such a form is used, a clear film can be obtained because it does not contain a coloring material. The following are mentioned as a use of the liquid composition of the form which does not contain a coloring material. For example, for an undercoat for imparting image recording suitability to a recording medium, or for an overcoat for the purpose of surface protection of an image formed with ordinary ink, further decoration or glossiness, etc. Is mentioned. In such a liquid composition, colorless pigments or fine particles that are not intended for coloring can be dispersed and contained in accordance with applications such as oxidation prevention and fading prevention. By adding these, it is possible to improve various characteristics such as image quality, fastness and workability (handling property) of the recorded matter in both the undercoat and the overcoat.

  When applying to such a use, it is preferable that content of the said polymeric substance in a liquid composition is 10.0 to 70.0 mass% on the basis of the total mass of a liquid composition. In the present invention, the polymerization initiator is contained in an amount of 1.0 to 15.0 parts by mass with respect to 100.0 parts by mass of the polymerizable substance, and 100.0 parts by mass of the liquid composition. On the other hand, it is preferable to prepare so that the said polymerization initiator may contain 0.5 mass part or more.

  As described above, when the liquid composition of the present invention is used in a form that does not contain a coloring material, it is preferable to contain a polymerization-reactive low-viscosity monomer as a solvent. The advantage of using these substances rather than ordinary solvents is that these substances do not remain as plasticizers in the solid after reaction cured with active energy rays, so the effect on the physical properties of the solid is reduced. There is. Reactive diluent components selected for such purposes include acryloylmorpholine, acrylamide, methylenebisacrylamide, monosaccharide monoacrylate, oligoethylene oxide monoacrylate, and dibasic monoacrylate The compound of this is mentioned.

  Furthermore, when the liquid composition of the present invention is used in a form that does not contain a coloring material, it is preferable not to use an additive that imparts moisture retention as described later. This is because in this case, since no solid component such as a pigment is contained, there is little thickening, and even if there is some thickening, it can be easily recovered. Of course, additives having higher moisturizing properties as described later can be added to the minimum necessary level. Various additives such as a surfactant may be added. These can be selected from a large number of compounds conventionally used for aqueous liquids for inkjet.

Next, the case where the liquid composition of the present invention is used as a form (ink) containing a coloring material will be described.
(Coloring materials / pigments)
The liquid composition according to the present invention can contain a coloring material such as a pigment. In this case, it is preferable to use a pigment dispersion in which a pigment is uniformly dispersed in an aqueous medium as a coloring material. As the pigment dispersion, it is particularly preferable to use a pigment dispersion in which a pigment is stably dispersed in water by the action of an anionic group. For example, a pigment dispersion that is stable in a nonionic or anionic system and that is used in a conventionally known inkjet ink can be applied as it is.

  The average particle diameter of the pigment particles is preferably in the range of about 25 nm to 350 nm, more preferably in the range of 70 nm to 200 nm. Although this range depends on the use of the recorded material, it is sufficiently smaller than the wavelength of visible light, so that a clear recorded material with less light scattering can be obtained.

  When a pigment is used as the color material, the concentration of the pure pigment in the liquid composition is preferably about 0.3% by mass or more and 10% by mass or less based on the total mass of the liquid composition. . Although depending on the coloring power of the pigment and the dispersion state of the pigment particles, when the concentration of the pure pigment component 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 concentration of the pigment dispersion also depends on the viscosity and flow characteristics required by the recording apparatus.

(Coloring materials / dyes)
The liquid composition according to the present invention is not limited to the pigment as described above, and a conventionally known dye is used as a coloring material, and an ink containing a water-soluble dye in a dissolved state may be used. This is possible as long as fading due to irradiation does not cause a practical problem. Further, a color material dispersion containing a disperse dye, an oil-soluble dye, or the like in a dispersed state can be applied in the same manner as the above-described pigment dispersion. These are appropriately selected according to the application.

  A preferable content of the dye in the liquid composition is 0.1% by mass or more and 10% by mass or less based on the total mass of the liquid composition. When the content of the dye is low, it can be suitably applied to so-called light ink.

(Other additives)
When the liquid composition according to the present invention is used as an ink by containing a coloring material, various additives such as a water-soluble organic solvent and a surfactant can be added to the ink. The additive is used for the purpose of suppressing the volatility of the ink, lowering the viscosity, and controlling the wettability to the printing substrate.

  In the case where 10.0% by mass or more of the additive is added to the ink (liquid composition), the recording medium on which the image is formed is fixed in the sense of increasing the strength of the finally obtained ink film. It must be liquid-absorbing. That is, in the case of recording with water-based gravure ink, a recording medium imparted with constant wettability and permeability is used and forced drying is performed. Also in the present invention, when the additive is added to the ink (liquid composition), for example, 10.0% by mass or more, a pretreatment for imparting ink acceptability to the recording medium is performed, and the ink is added. It is preferable to perform natural or forced drying treatment after curing with active energy rays. Since various polymerizable substances disclosed in the present invention have a high affinity for water, they themselves have a certain moisturizing property (= volatility suppression ability). For this reason, in the present invention, although it depends on the composition, an ink composition without an additive is also possible. Of course, measures such as capping, ink suction at the start of recording, and preliminary ejection may be used to ensure printing reliability at a practical level.

  In addition, in the case of recording on a non-liquid-absorbing base material, since the additive cannot be expected to be absorbed into the base material, the amount of the additive is kept to a minimum, if possible, almost all of the polymerizable substance components It is preferable to configure so that is hardened and solidified.

  In the case where the liquid composition of the present invention is used as an ink containing a coloring material, examples of additives that can be suitably used include alcohols such as the glycol ethers and glycerin described above.

  When the liquid composition according to the present invention is used as an ink containing a color material, the concentration of the polymerization initiator and the polymerizable substance in the ink is adjusted according to the absorption characteristics of the contained color material. It is preferable to adjust. As the blending amount, the content of a solvent not involved in the polymerization reaction (water, organic solvent, etc.) is preferably 40.0% by mass or more and 90.0% by mass or less based on the total mass of the liquid composition. Furthermore, it is more preferable to set it as 60.0 mass% or more and 75.0 mass% or less. Furthermore, the content of the polymerizable substance in the liquid composition is preferably 1.0% by mass or more and 35.0% by mass or less, particularly 10.0% by mass based on the total mass of the liquid composition. More preferably, the content is 25.0% by mass or less. Further, the content of the polymerization initiator depends on the content of the polymerizable substance, but is preferably 0.1% by mass or more and 7.0% by mass or less based on the total mass of the liquid composition. In particular, the content is more preferably 0.3% by mass or more and 5.0% by mass or less.

(Inkjet recording device)
The liquid composition of the present invention is provided in an ink jet recording apparatus comprising means for applying the liquid composition to a recording medium and means for irradiating active energy rays to the liquid composition applied to the recording medium. Applicable. In the present invention, the above-described ink jet recording apparatus is provided with a UV lamp provided on the front surface of the paper discharge unit, a paper feed / discharge paper wound around a rotating drum, and a drying unit. Can be selected as appropriate.

  Next, an ultraviolet irradiation apparatus as means for irradiating active energy rays, which is used for curing a liquid composition particularly suitable in the present invention, will be described. As the ultraviolet irradiation device, a so-called low-pressure mercury lamp in which the vapor pressure of mercury is 1 Pa or more and 10 Pa or less during lighting, a high-pressure mercury lamp, a mercury lamp coated with a phosphor, or the like is preferable. The emission spectrum of these mercury lamps in the ultraviolet region is 450 nm or less, particularly 184 nm or more and 450 nm or less, and is suitable for efficiently reacting a polymerizable substance in a black or colored liquid composition (ink). ing. Also, a small power supply can be used for mounting the power supply in the printer, which is also suitable in that sense. As the mercury lamp, for example, a metal halide lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a xenon flash lamp, a deep UV lamp, a lamp that uses a microwave to excite a mercury lamp from the outside, and a UV laser are practically used. Since these mercury lamps include the above-mentioned range as the emission wavelength region, they are basically applicable as long as power source size, input intensity, lamp shape, etc. are allowed. The light source is selected according to the sensitivity of the catalyst used. Also, an ultraviolet irradiation device using a light emitting diode type UV-LED, a UV excimer lamp, or the like can be used very suitably.

Note that ultraviolet intensity required degree 500 mW / cm ² or more 5,000 MW / cm ² or less is desirable from the sense of the polymerization rate. If the irradiation intensity is insufficient, the liquid composition of the present invention cannot be sufficiently cured. On the other hand, if the irradiation intensity is too strong, the printing substrate may be damaged or the color material may be discolored.

  Hereinafter, the present invention will be described more specifically with reference to examples, comparative examples, and reference examples. The present invention is not limited by the following examples unless it exceeds the gist.

(Examples 1-8, Comparative Examples 1-3)
After mixing each component shown in Table 1 and stirring sufficiently, pressure filtration was performed with a 1.2 micron filter, and the active energy ray-curable aqueous liquid compositions of Examples 1 to 8 and Comparative Examples 1 to 3 were used. Was prepared. Unless otherwise specified, the amount of a component in each liquid composition means “parts by mass”. The structures of Exemplified Compounds I-13, 15, 17, 18, 26, 27, II-1, 2, and 3 constituting each liquid composition are as described above. The structures of Comparative Compounds III and IV and Exemplary Compound 1 are shown below.

Comparative compound IV (water-insoluble acylphosphine photopolymerization initiator)
Irgacure 819DW manufactured by Ciba Specialty Chemicals

(Film formability evaluation)
Using each liquid composition having the composition shown in Table 1, the film formability was evaluated as follows. First, each liquid composition was coated on a commercially available PET (polyethylene terephthalate) film using a bar coater so as to be 5 g / m ² . Next, the PET film thus coated was applied to a UV irradiation apparatus. At this time, the UV lamp used was FUSION UV Systems Inc. Manufactured UV Curability Evaluation Device Model LH6B was used. The irradiation intensity was examined under the following three conditions. Condition A: 1,500 mW / cm ² , Condition B: 1,000 mW / cm ² , Condition C: 500 mW / cm ² , and the conveyance speed was 0.4 m / sec. The pencil hardness of the film thus formed was measured with a commercially available pencil hardness tester. The measurement results are summarized in Table 2. The pencil hardness measurement conforms to JIS.

  As shown in Table 2, when the liquid composition of the present invention was used, the curing characteristics were improved, high pencil hardness was achieved even under low irradiation conditions, and excellent curing characteristics were obtained.

(Examples 9-16, Comparative Examples 4-6)
First, a cyan pigment dispersion as a coloring material was prepared as follows. As a pigment, C.I. I. Pigment Blue 15: 3 was used. In addition, as a dispersing agent, a benzyl acrylate / methacrylic acid / ethylene glycol methacrylate ABC type block polymer (weight average molecular weight: 8,000, acid value: 350 mgKOH / g) neutralized with potassium hydroxide to a pH of about 7 Was used. Water was added to these and dispersed by a bead mill. Finally, a pigment dispersion having a pigment solid content of 10% by mass and a mass ratio of pigment to resin (P / B) = 3: 1 was obtained. The average particle size of the pigment used was 120 nm. The average particle size of the pigment was measured using a laser light scattering type particle size measuring device.

  Next, after mixing each component shown in Table 3 and stirring sufficiently, pressure filtration was performed using a filter having a pore size of 0.50 μm, and the liquid compositions (inks) of Examples 9 to 16 and Comparative Examples 4 to 6 were used. Was 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.

(Evaluation)
Each liquid composition (ink) prepared as described above was evaluated in the following manner.
An on-demand type ink jet recording apparatus Pixus 550i (manufactured by Canon) was prepared which ejects ink by applying thermal energy corresponding to the recording signal to the ink. A UV lamp that excites a mercury lamp with no electrode from the outside using a microwave is mounted at a position adjacent to the recording head portion of the recording apparatus. Next, this printer was used for evaluation according to the evaluation methods and evaluation criteria described in (1) to (3) below. The UV lamp used a D bulb. The intensity at the irradiation position was 1,500 mW / cm ² . The irradiation conditions were such that the integrated irradiation energy was Condition D: 800 mJ / cm ² , Condition E: 400 mJ / cm ² , and Condition F: 100 mJ / cm ² . The evaluation results are shown in Table 4.

(1) Ink curing performance A 100% solid image was recorded on a PET film using the inks of Examples 9 to 16 and Comparative Examples 4 to 6 and the above recording apparatus. In the present invention, recording in which one pixel of a recorded image formed at 600 × 600 dpi is completely filled with about 5 pL dots is called 100% solid. The pencil hardness of the film thus formed was measured using a commercially available pencil hardness tester in the same manner as the measurement methods in Examples 1 to 8 and Comparative Examples 1 to 3.

(2) Discharge stability The above printer was filled with each predetermined ink, and horizontal ruled lines were continuously recorded on PPC paper (manufactured by Canon), and the thickness of the lines and the dot landing positions were evaluated visually. .
A: There was no change in the thickness of the line, and there was no deviation in the landing position. B: There was a slight change in the thickness or landing deviation.

(3) Storage stability over time Predetermined ink was placed in a fluororesin sealed container free from disturbance due to elution, and stored in an oven at 60 ° C. in a dark place for 1 month. The rate of change was determined from the average particle diameter of the pigment in the ink stored in each environment, and evaluated according to the following criteria.
A: Change rate of average particle size is within ± 10% B: Change rate of average particle size is over ± 10% and within ± 15% C: Change rate of average particle size is over ± 15%

  As shown in Table 4, when the liquid composition (ink) of the present invention was used, sufficient pencil hardness was obtained even under low irradiation conditions for the curing characteristics. The liquid composition (ink) of the present invention was excellent in ejection stability and storage stability with time.

(Examples 17-19, Comparative Examples 7-9)
Example 17, Comparative Example 7: Evaluation of Yellow Ink Example 18, Comparative Example 8: Evaluation of Magenta Ink Example 19, Comparative Example 9: Evaluation of Red Recording Portion

  Next, yellow and magenta pigment dispersions were prepared in exactly the same manner as the cyan pigment dispersions used in Examples 9-16.

(Preparation of yellow pigment dispersion)
As a pigment, C.I. I. Except for using Pigment Yellow 13, a yellow pigment dispersion having a pigment solid content of 10% by mass, P / B = 3/1, and an average particle size of 130 nm was prepared in the same manner as that for preparing a cyan pigment dispersion.

(Preparation of magenta pigment dispersion)
As a pigment, C.I. I. Except for using Pigment Red 122, a magenta pigment dispersion having a pigment solid content of 10% by mass, P / B = 3/1, and an average particle size of 125 nm was prepared in exactly the same manner as the preparation of the cyan pigment dispersion.

(Preparation of yellow ink and magenta ink)
Next, a yellow ink of Example 17 was prepared in exactly the same manner as the ink of Example 13 except that the cyan pigment dispersion was replaced with the yellow pigment dispersion prepared above. Next, a magenta ink of Example 18 was prepared in exactly the same manner as the ink of Example 13 except that the cyan pigment dispersion was replaced with the magenta pigment dispersion prepared above.

  In addition, as a comparative example, the yellow pigment dispersion and cyan pigment dispersion prepared above were used in the same manner as the inks of Examples 17 and 18 using the composition of Comparative Example 4 shown in Table 3. The yellow ink of Comparative Example 7 and the magenta ink of Comparative Example 8 were prepared using the body.

(Evaluation)
In addition to the yellow ink and magenta ink prepared above, the ink of Example 13 (cyan ink) was combined to form an ink set used for evaluation of Examples 17-19. Using this ink set, the same recording apparatus as used in the evaluation of Example 13 was used, and the following recording was performed on PET film and offset printing paper OK Kanto made by Mitsubishi Paper Industries. That is, 100% solid recording of yellow and magenta, and the secondary color red of Example 19 and Comparative Example 9 formed with yellow 100% solid and magenta 100% solid were recorded. Moreover, UV irradiation was performed by the completely same method as the conditions E in evaluation of Example 13. FIG. With respect to the yellow, magenta, and red portions of the recorded image thus formed, the pencil hardness test was performed on the PET film recorded material in the same manner as in Example 9. Further, the following fixability test was performed on the above-described offset printing paper. Further, using the yellow ink and magenta ink thus prepared, the following marker resistance test was performed. Further, using the yellow ink and the magenta ink prepared as described above, an ejection stability test and a storage stability test with time were performed in exactly the same manner as the ink of Example 13. The evaluation results are shown in Table 5.

-Fixability test 10 seconds after recording, the sample was placed on the recording medium on which the sylbon paper was placed, and the sylbon paper was pulled with a load of 40 g / cm ² on the recording surface. It was visually observed whether or not dirt was generated by rubbing of the recording portion on the non-recording portion (white background portion) and the Sylbon paper of the recording medium, and evaluated according to the following criteria.
A: No dirt due to rubbing B: Little dirt due to rubbing C: Dirt due to rubbing is conspicuous

Marker resistance test Using the yellow ink, magenta ink, and the printer described in Examples 17 and 18 and Comparative Examples 7 and 8, 12 point characters were recorded on PPC paper made by Canon. After 1 minute of recording, the above-mentioned sample was marked once with a normal pen pressure using a pilot fluorescent pen spot lighter yellow, 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 the marker does not occur B: Character disorder due to the marker slightly occurs C: Character disorder due to the marker significantly occurs

  As shown in Table 5, when the liquid composition (ink) of the present invention was used, it was excellent in curing characteristics and sufficient pencil hardness, fixing property, and marker resistance were obtained. The liquid composition (ink) of the present invention was excellent in ejection stability and stability over time.

Claims (8)

An aqueous liquid composition comprising an amide compound, a vinylaryl compound, and a photopolymerization initiator and cured by irradiation with active energy rays,
The amide compound includes at least one amide compound represented by the following general formula (1) and the following general formula (2), and the vinyl aryl compound is represented by the following general formula (3) A liquid composition comprising:

(In general formula (1), R ₁ is an n (= n1 + n2) valent organic group, R ₂ is independently a hydrogen atom or a monovalent organic group, X is a divalent organic group having a double bond, Y Is an alkali metal or an organic base, n1 is an integer of 1 or more, n2 is an integer of 0 or more, and n (= n1 + n2) is an integer of 2 or more.)

(In general formula (2), R ₃ is an n-valent organic group, R ₄ and R ₅ are each independently a hydrogen atom or a monovalent organic group, and n is an integer of 1 or more.)

(In general formula (3), R ₁₂ is an m-valent organic group, R ₁₃ is a hydrogen atom or a monovalent organic group, m is an integer of 1 or more, and m + n ≧ 3.)   The liquid composition according to claim 1, wherein the photopolymerization initiator is a photoradical generator.   The liquid composition according to claim 1 or 2, wherein at least one of the photopolymerization initiators is a hydrophilic acylphosphine oxide compound.   Furthermore, the liquid composition of any one of the Claims 1 thru | or 3 formed by containing a coloring material.   The liquid composition according to any one of claims 1 to 4, which is used for inkjet.   A step of discharging the liquid composition according to claim 5 onto a recording medium, and a step of curing the liquid composition by irradiating an active energy ray to the recording medium provided with the liquid composition. Inkjet recording method.   6. An ink jet recording comprising: means for applying the liquid composition according to claim 5 to a recording medium; and means for irradiating the liquid composition applied to the recording medium with active energy rays. apparatus.   A recorded image formed by the ink jet recording method according to claim 6.