JP6266073B1 - Active energy ray-curable ink composition, laminate using this ink composition, image forming method for forming an image on a substrate, and method for producing printed matter - Google Patents

Abstract

Provided is an active energy ray-curable ink composition capable of forming a cured film that enables both stretchability and tack reduction. As active energy ray polymerizable monomers, 40% by mass or more of monomer A): a monofunctional monomer represented by formula (1) and 20% by mass or less of monomer B): represented by formula (2) An active energy ray-curable ink composition containing a polyfunctional monomer. (R1 is a functional group having an oxygen-containing heterocyclic structure; R2 is a C1-5 alkylene group; R3 is H or a C1-4 alkyl group) R4-CH = CR1-COOR2-O-CH = CH-R3.・ (2) [Selected figure] None

Description

  The present invention relates to an active energy ray-curable ink composition mainly used as an inkjet ink, a laminate on which the ink composition is printed, and an image and / or an uneven image on a substrate using the ink composition. The present invention relates to an image forming method to be formed, and a method for producing a printed matter using the ink composition.

  2. Description of the Related Art Conventionally, active energy ray-curable ink compositions that are cured by ultraviolet rays, electron beams, or other active energy rays have been developed. Since the active energy ray-curable ink composition is quick-drying, ink bleeding can be prevented even when printing on a substrate that does not absorb or hardly absorbs ink, such as plastic, glass, and coated paper. The active energy ray-curable ink composition is composed of an active energy ray polymerizable monomer, a coloring material, and other additives.

  For example, Patent Document 1 discloses an active energy ray-curable ink composition containing cyclic trimethylolpropane formal acrylate (CTFA) and containing almost no volatile compound.

  According to Patent Document 1, the active energy ray-curable ink composition containing cyclic trimethylolpropane formal acrylate (CTFA) has a low viscosity and a low odor. Furthermore, the cured film formed by the active energy ray-curable ink composition is excellent in the curing speed and flexibility (stretchability).

Special table 2010-540751 gazette

  Even if the cured film has stretchability, if the surface of the cured film is tacky, the surface of the cured film tends to adhere dust, dust, mud, soot, pitch, etc., which is preferable from the viewpoint of the design of the printed matter. However, when the cured film comes into contact with another substrate, there arises a problem that the cured film adheres to the other substrate. In this specification, the term “tack” means that the surface of the cured film is sticky when touched with a finger. Thus, stretchability and tack in the cured film are in a trade-off relationship.

  According to Patent Literature 1, the active energy ray-curable ink composition of Patent Literature 1 is said to have the curing speed and flexibility (stretchability) of a cured film formed from the active energy ray-curable ink composition. However, in Patent Document 1, no consideration has been given to the compatibility between stretchability and tack reduction in the cured film.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an active energy ray-curable ink capable of forming a cured film that enables both stretchability and tack reduction. It is to provide a composition.

  In order to solve the above-mentioned problems, the present inventor has conducted extensive research and found that it is an active energy ray-curable ink composition containing a monofunctional monomer and a polyfunctional monomer having a specific structure, each active energy ray. The present inventors have found that the above problems can be solved by an active energy ray-curable ink composition in which the content ratio of the polymerizable monomer is adjusted, and have completed the present invention. Specifically, the present invention provides the following.

（式中、Ｒ^１は含酸素複素環構造を有する官能基である。Ｒ^２は炭素数１以上５以下のアルキレン基を示す。Ｒ^３は水素原子又は炭素数１以上４以下のアルキル基を示す。）
Ｒ^４−ＣＨ＝ＣＲ^１−ＣＯＯＲ^２−Ｏ−ＣＨ＝ＣＨ−Ｒ^３ ・・・（２）
（式中、Ｒ^１は水素原子又はメチル基を示し、Ｒ^２は炭素数２以上２０以下の２価の有機残基を示し、Ｒ^３は水素原子又は炭素数１以上１１以下の１価の有機残基を示し、Ｒ^４は水素原子又は炭素数１以上４以下のアルキル基を示す。） (1) As an active energy ray polymerizable monomer,
Monomer A): a monofunctional monomer represented by the following general formula (1),
Monomer B): a polyfunctional monomer represented by the following general formula (2),
The total content of the monomer A) is 40% by mass or more based on the total amount of the active energy ray-curable ink composition,
An active energy ray-curable ink composition in which the total content of the monomers B) is 20% by mass or less based on the total amount of the active energy ray-curable ink composition.

(In the formula, R ¹ represents a functional group having an oxygen-containing heterocyclic structure. R ² represents an alkylene group having 1 to 5 carbon atoms. R ³ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Show.)
R ⁴ —CH═CR ¹ —COOR ² —O—CH═CH—R ³ (2)
(In the formula, R ¹ represents a hydrogen atom or a methyl group, R ² represents a divalent organic residue having 2 to 20 carbon atoms, and R ³ represents a hydrogen atom or a monovalent organic group having 1 to 11 carbon atoms. represents an organic residue, R ⁴ denotes a hydrogen atom or having 1 to 4 alkyl group carbon atoms.)

(2) The active energy ray-curable ink composition according to (1), wherein the heterocyclic structure of R ¹ in the monomer A) is a saturated heterocyclic structure.

  (3) The monomer A) includes at least a monomer A1) and a monomer A2) which are two types of monofunctional monomers having different molecular structures, and the glass transition point of the monomer A1) is the glass of the monomer A2). The active energy ray-curable ink composition according to (1) or (2), which is smaller than the transition point.

  (4) The active energy ray-curable ink composition according to (3), wherein the glass transition point of the monomer A1) is 25 ° C. or less smaller than the glass transition point of the monomer A2).

(5) The monomer A1) has a glass transition point of −5 ° C. or lower,
The active energy ray-curable ink composition according to (4), wherein the monomer A2) is a monomer having a glass transition point of 25 ° C. or higher.

（式中、Ｒ^１−１及びＲ^１−２は、それぞれ独立して、水素原子、直鎖、分岐鎖もしくは環状の炭素数１以上１８以下のアルキル基又はフェニル基であり、Ｒ^１−１とＲ^１−２とは結合して環を形成していても良い。Ｒ^２は炭素数１以上５以下のアルキレン基を示す。Ｒ^３は水素原子又は炭素数１以上５以下のアルキル基を示す。）
前記モノマーＡ２）が、下記一般式（４）で表されるモノマーである請求項３から５のいずれかに記載の活性エネルギー線硬化型インク組成物。

（式中、Ｒ^１−１及びＲ^１−２は、それぞれ独立に、水素原子、又は、炭素数１以上４以下のアルキル基を示す。Ｒ^２は炭素数１以上５以下のアルキレン基を示す。Ｒ^３は水素原子又は炭素数１以上４以下のアルキル基を示す。Ｒ^４は水素原子又は炭素数１以上４以下のアルキル基を示す。） (6) The monomer A1) is at least one monomer selected from the group consisting of tetrahydrofurfuryl acrylate and a monomer represented by the following general formula (3),

(In the formula, R ^1-1 and R ^1-2 are each independently a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms or a phenyl group, and R ^1-1. And R ^1-2 may be bonded to form a ring, R ² represents an alkylene group having 1 to 5 carbon atoms, R ³ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Show.)
6. The active energy ray-curable ink composition according to claim 3, wherein the monomer A2) is a monomer represented by the following general formula (4).

(In the formula, R ^1-1 and R ^1-2 each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R ² represents an alkylene group having 1 to 5 carbon atoms. R ³ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ⁴ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.)

  (7) The content ratio between the monomer A1) and the monomer A2) is 1.3 to 16 in terms of a mass ratio of monomer A1) / monomer A2), according to any one of (3) to (6) Active energy ray-curable ink composition.

  (8) The active energy ray-curable ink composition according to any one of (1) to (7), further comprising an alkylcycloalkyl acrylate.

  (9) The active energy ray-curable ink composition according to any one of (1) to (8), which is used as an inkjet ink.

  (10) The active energy ray-curable ink composition according to any one of (1) to (9) is formed on a vinyl chloride sheet having a thickness of 80 μm as a cured film having a thickness of 10 μm. When the cured film-forming substrate was subjected to a tensile test at 25 ° C. and a tensile speed of 10 mm / min as a dumbbell-shaped No. 6 type (JIS K6251-5) test piece, cracks in the cured film were observed. An active energy ray-curable ink composition having a cured film elongation at break of 50% or more.

  (11) A laminate in which an ink cured film layer that is a cured film of the active energy ray-curable ink composition according to any one of (1) to (10) is formed on a substrate.

  (12) An image forming method for forming an image and / or an uneven image on a substrate using the active energy ray-curable ink composition according to any one of (1) to (10).

  (13) A method for producing a printed material, wherein an image and / or a concavo-convex image is formed on a substrate using the active energy ray-curable ink composition according to any one of (1) to (10).

  The active energy ray-curable ink composition of the present invention is an active energy ray-curable ink composition capable of forming a cured film that enables both stretchability and tack reduction.

  Hereinafter, specific embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and may be implemented with appropriate modifications within the scope of the object of the present invention. can do.

<Active energy ray-curable ink composition>
The active energy ray-curable ink composition of one embodiment of the present invention includes a monomer A) which is a monofunctional monomer represented by the following general formula (1), and a polyfunctional monomer represented by the following general formula (2) And an active energy ray-curable ink composition containing the monomer B). In the present specification, “containing a monomer such as monomer A)” not only includes a single monomer A) having the same molecular structure but also two or more different molecular structures. It is also a concept that includes a monomer such as monomer A).

（式中、Ｒ^１は含酸素複素環構造を有する官能基である。Ｒ^２は炭素数１以上５以下のアルキレン基を示す。Ｒ^３は水素原子又は炭素数１以上４以下のアルキル基を示す。）

(In the formula, R ¹ represents a functional group having an oxygen-containing heterocyclic structure. R ² represents an alkylene group having 1 to 5 carbon atoms. R ³ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Show.)

R ⁴ —CH═CR ¹ —COOR ² —O—CH═CH—R ³ (2)
(In the formula, R ¹ represents a hydrogen atom or a methyl group, R ² represents a divalent organic residue having 2 to 20 carbon atoms, and R ³ represents a hydrogen atom or a monovalent organic group having 1 to 11 carbon atoms. Represents an organic residue, and R ⁴ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.)

  The monomer A) represented by the general formula (1) and the monomer B) represented by the general formula (2) have a low viscosity. Therefore, the active energy ray-curable ink composition containing the monomer A) represented by the general formula (1) and the monomer B) represented by the general formula (2) has a viscosity even at room temperature. The active energy ray-curable ink composition is low and has high ejection stability.

  In the active energy ray-curable ink composition of the present invention, the total content of the monomer A) represented by the general formula (1) is 40% by mass or more. Furthermore, the total content of the monomer B) represented by the general formula (2) is 20% by mass or less. By optimizing the contents of the monomer A) and the monomer B), it is possible to impart curability and stretchability to the cured film and to reduce tackiness on the surface of the cured film. Therefore, the active energy ray-curable ink composition of the present invention is an active energy ray-curable ink composition capable of forming a cured film that enables both stretchability and tack reduction.

  Moreover, since the monofunctional monomer represented by the general formula (1) and the polyfunctional monomer represented by the general formula (2) have a small odor, the odor of the active energy ray-curable ink composition containing these monomers is low. small. In the present specification, the low odor of the active energy ray curable ink composition means that the active energy ray curable ink composition itself has a low odor, and the active energy ray curable type has a low odor. If it is an ink composition, when handling an active energy ray-curable ink composition, when forming an image on a substrate using the active energy ray-curable ink composition, or an active energy ray-curable ink composition It is possible to concentrate on work without worrying about odors when manufacturing printed matter using, and even a worker with sensitive nose can work without a mask. There is a merit that it becomes.

  It is not always easy to develop an active energy ray-curable ink composition having a low odor and a low viscosity and satisfying all physical properties necessary for the active energy ray-curable ink composition. For example, if the active energy ray polymerizable monomer has a high boiling point, the active energy ray polymerizable monomer is hardly vaporized in a room temperature environment, and thus tends to be an active energy ray polymerizable monomer having a small odor. However, high-boiling active energy ray-polymerizable monomers often have high boiling points due to an increase in molecular force between active energy ray-polymerizable monomers due to an increase in molecular weight. Viscosity tends to increase. Therefore, the active energy ray-curable ink composition itself containing such an active energy ray-polymerizable monomer also has a high viscosity and is difficult to be ejected as an ink jet.

  Also, even if the active energy ray polymerizable monomer has a low odor and low viscosity, the glass transition point (Tg) is extremely low, and the curability of the cured film formed by the active energy ray polymerizable monomer is extremely inferior. There is also. Hereinafter, the “active energy ray-curable ink composition” has characteristics that the cured film formed by the active energy ray-polymerizable monomer has the curability of the “active energy ray-curable ink composition” or “ink” It may be referred to as “curability of the composition”.

  A monomer A) which is a monofunctional monomer represented by the general formula (1) and a monomer B) which is a polyfunctional monomer represented by the general formula (2), and each of the active energy ray polymerizable monomers The active energy ray-curable ink composition of the present invention with the content ratio adjusted is an active energy ray-curable ink composition having low viscosity and high ejection stability even at room temperature. It can be set as the active energy ray hardening-type ink composition which can satisfy | fill the physical property required for the ink composition used as ink.

  The viscosity at a measurement temperature of 25 ° C. measured based on JIS Z 8803: 2001 of the active energy ray-curable ink composition of the present invention is preferably 20 mPa · s or less, and preferably 10 mPa · s or less. It is more preferable, and it is still more preferable that it is 8 mPa * s or less. When the viscosity is 20 mPa · s or less, the ejection stability in inkjet is improved.

Hereinafter, the active energy ray polymerizable monomer contained in the active energy ray-curable ink composition of the present invention will be described.
(Monofunctional monomer)
[Monomer A): Monofunctional monomer represented by general formula (1)]
Monomer A) is a monofunctional monomer represented by the following general formula (1). By containing the monomer A), the curing by the active energy ray is affected, the curing speed is increased, and the curability of the ink composition can be improved. In addition, since a cured film having stretchability can be formed by adjusting the ratio of the content of monomer A) and monomer B) described later, the active energy ray-curable ink composition of the present invention is used. The cured film is a cured film having both stretchability and curability. Furthermore, since the monofunctional monomer represented by the following general formula (1) has a low odor, the active energy having a large odor due to the monomer A) being contained in the active energy ray-curable ink composition. It is not a linear curable ink composition. Furthermore, since the monofunctional monomer represented by the following general formula (1) has a low viscosity, the viscosity of the active energy ray-curable ink composition is increased due to the inclusion of the monomer A). Absent. For this reason, the active energy ray-curable ink composition containing the monomer A) has a very high ejection stability in inkjet, and can be an active energy ray-curable ink composition preferable as an inkjet ink.

（式中、Ｒ^１は含酸素複素環構造を有する官能基である。Ｒ^２は炭素数１以上５以下のアルキレン基を示す。Ｒ^３は水素原子又は炭素数１以上４以下のアルキル基を示す。）

(In the formula, R ¹ represents a functional group having an oxygen-containing heterocyclic structure. R ² represents an alkylene group having 1 to 5 carbon atoms. R ³ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Show.)

In this specification, the oxygen-containing heterocyclic structure means a cyclic molecular structure composed of at least an oxygen element and a carbon element. The functional group having an oxygen-containing heterocyclic structure means a functional group in which an oxygen-containing heterocyclic structure is included in a part of the molecular structure of the functional group. If R ¹ is a functional group having an oxygen-containing heterocyclic structure, for example, a structure having other substituents and the like branched to an oxygen-containing heterocyclic structure (for example, R ^1-1 or R in the following general formula (3)) ^1-2 , a structure having a substituent such as R ^1-1 , R ^1-2 or R ^{4 in the following} general formula (4) may be used.

The alkylene group having 1 to 5 carbon atoms of R ² means a linear, branched or cyclic alkylene group having 1 to 5 carbon atoms which may be substituted.

The hydrogen atom of R ³ or an alkyl group having 1 to 4 carbon atoms means a linear, branched or cyclic optionally substituted alkylene group having 1 to 4 carbon atoms.

R ¹ is a functional group having an oxygen-containing heterocyclic structure, but the oxygen-containing heterocyclic structure of R ¹ is preferably a saturated heterocyclic structure.

R ² is an alkylene group having 1 to 5 carbon atoms, but R ² is preferably a linear or branched alkylene group having 1 to 3 carbon atoms, and is a methylene group having 1 carbon atom. More preferably.

R ³ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, but R ² is preferably a hydrogen atom or a linear or branched alkyl group having 1 to 3 carbon atoms, Or it is more preferable that it is a C1-methyl group.

  Further, the total content of the monomers A) is preferably 40% by mass or more, more preferably 45% by mass or more, and most preferably 50% by mass or more in the total amount of the active energy ray-curable ink composition. preferable. When the total content of the monomers A) is less than 40% by mass in the total amount of the active energy ray-curable ink composition, the odor of the active energy ray-curable ink composition is reduced and a stretched cured film is formed. It becomes difficult.

  Further, the total content of the monomers A) is preferably 90% by mass or less, more preferably 80% by mass or less, and most preferably 70% by mass or less in the total amount of the active energy ray-curable ink composition. preferable. When the total content of the monomers A) is 90% by mass or less based on the total amount of the active energy ray-curable ink composition, the curability of the active energy ray-curable ink composition is improved and the surface of the cured film is tacked. Can be reduced.

  Examples of monomer A) include tetrahydrofurfuryl acrylate (THFA), trimethylolpropane formal acrylate (CTFA), (2-methyl-2-ethyl-1,3-dioxolan-4-yl) methyl acrylate, (2- And methyl-2-isobutyl-1,3-dioxolan-4-yl) methyl (meth) acrylate, (cyclohexanespiro-2- (1,3-dioxolan-4-yl)) methyl (meth) acrylate, and the like. Yes, but not limited to this. Among the monomers A), tetrahydrofurfuryl acrylate (THFA) and (2-methyl-2-ethyl-1,3-dioxolan-4-yl) methyl acrylate are preferable from the viewpoint of low viscosity and extremely low odor. Tetrahydrofurfuryl acrylate (THFA) is most preferred.

  The monomer A) may be only a single monomer having the same molecular structure as long as it is a monofunctional monomer represented by the general formula (1), but at least two monofunctional monomers having different molecular structures. It is preferable that the glass transition point of monomer A1) is smaller than the glass transition point of monomer A2). By including at least two types of monofunctional monomers having different glass transition points and having different molecular structures, it is possible to adjust the stretchability of the cured film, which is difficult to achieve both, and the reduction of tack to a more preferable range. Thereafter, in the active energy ray-curable ink composition containing two types of monomers A) having different molecular structures, the monomer A) having the lower glass transition point is changed to the monomer A1) and the monomer A having the higher glass transition point. ) May be referred to as monomer A2).

  As a method for adjusting the stretchability of the cured film and the reduction of tack to a more preferable range, for example, a method using two or more monomers A) having different glass transition points can be mentioned. For example, by containing a predetermined amount of monomer A1) having a low glass transition point, the stretchability of the cured film is improved, and by containing a predetermined amount of monomer A2) having a high glass transition point, the curability of the cured film is increased. Can be improved. By including two or more types of monomers A) having different glass transition points, it is possible to achieve both the stretchability of the cured film originally having a trade-off relationship and the reduction of tack. From the viewpoint of achieving both the stretchability of the cured film and the reduction of tack, the glass transition point of the monomer A1) is preferably 25 ° C. or more lower than the glass transition point of the monomer A2), more preferably 30 ° C. or less. Most preferably, it is smaller than 35 ° C.

  Monomers A1) and monomers A2) having different glass transition points are preferably selected from the monomers A) listed above so that the difference in glass transition points is a predetermined difference.

  As an example of selection of monomer A1) and monomer A2) having different glass transition points, monomer A1) has a glass transition point of −5 ° C. or lower, and monomer A2) has a glass transition point of 25 ° C. or higher. Mention may be made of certain monomers A1) and monomers A2). By setting the glass transition points of the monomer A1) and the monomer A2) within this range, it is possible to more effectively adjust the stretchability of the cured film and the reduction of tack to a preferable range. The monomer A1) is more preferably a monomer having a glass transition point of −10 ° C. or lower.

  Examples of the monomer A1) include, but are not limited to, tetrahydrofurfuryl acrylate (THFA), a monomer represented by the following general formula (3), and the like. From the viewpoint of low viscosity and extremely low odor, tetrahydrofurfuryl acrylate (THFA) is most preferable.

（式中、Ｒ^１−１及びＲ^１−２は、それぞれ独立して、水素原子、直鎖、分岐鎖もしくは環状の炭素数１以上１８以下のアルキル基又はフェニル基であり、Ｒ^１−１とＲ^１−２とは結合して環を形成していても良い。Ｒ^２は炭素数１以上５以下のアルキレン基を示す。Ｒ^３は水素原子又は炭素数１以上５以下のアルキル基を示す。）

(In the formula, R ^1-1 and R ^1-2 are each independently a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms or a phenyl group, and R ^1-1. And R ^1-2 may be bonded to form a ring, R ² represents an alkylene group having 1 to 5 carbon atoms, R ³ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Show.)

R ² represents an alkylene group having 1 to 5 carbon atoms, which may be a linear, branched or cyclic alkylene group having 1 to 5 carbon atoms. R ³ is an alkyl group having 1 to 5 carbon atoms, which means a linear, branched or cyclic alkyl group having 1 to 5 carbon atoms which may be substituted.

  Examples of the monomer A2) include a monomer represented by the following general formula (4). The monomer A2) is not limited to the monomer represented by the following general formula (4).

（式中、Ｒ^１−１及びＲ^１−２は、それぞれ独立に、水素原子、又は、炭素数１以上４以下のアルキル基を示す。Ｒ^２は炭素数１以上５以下のアルキレン基を示す。Ｒ^３は水素原子又は炭素数１以上４以下のアルキル基を示す。Ｒ^４は水素原子又は炭素数１以上４以下のアルキル基を示す。）

(In the formula, R ^1-1 and R ^1-2 each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R ² represents an alkylene group having 1 to 5 carbon atoms. R ³ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ⁴ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.)

  An alkylene group having 1 to 5 carbon atoms means a linear, branched or cyclic alkylene group having 1 to 5 carbon atoms which may be substituted.

  The hydrogen atom or the alkyl group having 1 to 4 carbon atoms means a linear, branched or cyclic alkylene group having 1 to 4 carbon atoms which may be substituted.

  A trimethylolpropane formal acrylate (CTFA) can be mentioned, but is not limited thereto. Trimethylolpropane formal acrylate (CTFA) is most preferable from the viewpoint of low viscosity and extremely low odor.

  The method for synthesizing the monomer represented by the general formula (4) is not particularly limited. For example, monohydroxy cyclic acetal and (meth) acrylate as described in JP-A-2015-189734 and JP-A-2006-056153 It can synthesize | combine by transesterification with. The monohydroxy cyclic acetal is not limited to the trimethylolpropane cyclic formal described in the above patent document. For example, various monohydroxy cyclic acetals are exemplified as described on page 11 of JP-A-2-01373. Hydroxy cyclic acetals can be used.

  The content ratio of the monomer A1) to the monomer A2) is preferably 1.3 or more, more preferably 1.5 or more, and more preferably 1.8 or more in terms of the mass ratio of monomer A1) / monomer A2). More preferably. By setting the content ratio of monomer A1) and monomer A2) to 1.3 or more in terms of the mass ratio of monomer A1) / monomer A2), it is possible to more effectively reduce the stretchability of the cured film and reduce tack. Can be adjusted.

  The content ratio of monomer A1) to monomer A2) is preferably 16 or less, more preferably 14 or less, and even more preferably 11 or less, in terms of mass ratio of monomer A1) / monomer A2). . By adjusting the content ratio of monomer A1) and monomer A2) to 16 or less by mass ratio of monomer A1) / monomer A2), the stretchability of the cured film and the reduction of tack are more effectively adjusted to the preferred range. can do.

[Monofunctional monomer other than monomer A)
The active energy ray-curable ink composition of the present invention may contain a monofunctional monomer other than the monomer A). As the monofunctional monomer other than the monomer A), any conventionally known monofunctional monomer can be used. For example, 4-tert-butylcyclohexyl acrylate, benzyl acrylate, 2-phenoxyethyl acrylate, which are alkylcycloalkyl acrylates, can be used. , Isobornyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, γ-butyrolactone acrylate, cresol acrylate, 2-acryloyloxyethyl phthalate, 2-acryloyloxyethyl-2-hydroxy Ethyl phthalate, 2-acryloyloxyethyl hexahydrophthalate, 2-acryloyloxypropyl phthalate, paracumylphenoxyethylene glycol acrylate , Nonylphenoxypolyethylene glycol acrylate, 1-adamantyl acrylate, cyclohexyl acrylate, 3-3-5-trimethylcyclohexanol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, acryloylmorpholine, N-vinylcaprolactam, imide acrylate, iso Octyl acrylate, tridecyl acrylate, lauryl acrylate, 2-hydroxyethyl acrylate, stearyl acrylate, isodecyl acrylate, caprolactone acrylate, methoxypolyethylene glycol acrylate, methoxypolypropylene glycol acrylate, 2-methoxyethyl acrylate, ethyl carbitol acrylate, 2-ethylhexyl Acrylate, and Examples of these acrylates include those having various modifications such as alkoxy modification and caprolactone modification. A monofunctional monomer other than the monomer A) is not essential in the active energy ray-curable ink composition of the present invention, but when a monofunctional monomer other than the monomer A) is used, it has a low odor and a low viscosity. From the viewpoint, it is preferable to use an alkylcycloalkyl acrylate such as 4-t-butylcyclohexyl acrylate.

  Monofunctional monomers (alkyl cycloalkyl acrylates such as 4-t-butylcyclohexyl acrylate, benzyl acrylate, 2-phenoxyethyl acrylate, isobornyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl) other than the above-described monomer A) Acrylate, dicyclopentenyloxyethyl acrylate, γ-butyrolactone acrylate, cresol acrylate, 2-acryloyloxyethyl phthalate, 2-acryloyloxyethyl-2-hydroxyethyl phthalate, 2-acryloyloxyethyl hexahydrophthalate, 2- Acryloyloxypropyl phthalate, paracumylphenoxyethylene glycol acrylate, nonylphenoxy polyethylene glycol acrylate, -Adamantyl acrylate, cyclohexyl acrylate, 3-3-5-trimethylcyclohexanol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, acryloylmorpholine, N-vinylcaprolactam, imide acrylate, isooctyl acrylate, tridecyl acrylate, lauryl acrylate 2-hydroxyethyl acrylate, stearyl acrylate, isodecyl acrylate, caprolactone acrylate, methoxypolyethylene glycol acrylate, methoxypolypropylene glycol acrylate, 2-methoxyethyl acrylate, ethyl carbitol acrylate, 2-ethylhexyl acrylate, and alkoxy to these acrylates Modification and caprolactone modification Those having various modifications such as properties (hereinafter simply referred to as “monofunctional monomers other than the above-mentioned monomer A”)) are not essential in the active energy ray-curable ink composition of the present invention. When the monofunctional monomer other than the monomer A) described above is contained in the active energy ray curable ink composition of the present invention, the total content of the monofunctional monomer other than the monomer A) described above is the active energy ray curable type. The total amount of the ink composition is preferably 5% by mass or more, and more preferably 15% by mass or more. In addition, the total content of monofunctional monomers other than the monomer A) described above is preferably 35% by mass or less, more preferably 25% by mass or less, based on the total amount of the active energy ray-curable ink composition.

  The total content of the monofunctional monomer other than the monomer A) and / or the above-described monomer A) in the total amount of the monofunctional monomer is preferably 90% by mass or more, and 95% by mass or more in the content of the monofunctional monomer. It is more preferable that it is 99 mass% or more.

[Content of monofunctional monomer]
The total content of monofunctional monomers contained in the active energy ray-curable ink composition of the present invention is 60% by mass or more, preferably 70% by mass or more, based on the total amount of the active energy ray polymerizable monomer, and is 80% by mass. % Or more is more preferable. When the total content of monofunctional monomers contained in the active energy ray-curable ink composition of the present invention is 60% by mass or more, the stretchability of the cured film and the reduction of tack are more effectively adjusted to a preferable range. can do.

  Further, the total content of monofunctional monomers contained in the active energy ray-curable ink composition of the present invention is preferably 95% by mass or less, and 90% by mass or less, based on the total amount of the active energy ray polymerizable monomer. Is more preferable.

  The active energy ray-curable ink composition of the present invention imparts stretchability to a cured film by adjusting the ratio of the total content of monofunctional monomers including monomer A) in the total amount of active energy ray polymerizable monomers. Even when a flexible base material is used as a recording medium, cracks in the cured film can be suppressed.

[Monomer B): Multifunctional monomer represented by general formula (2)]
Monomer B) is a polyfunctional monomer represented by the following general formula (2). By containing the monomer B), it is possible to improve the curability of the active energy ray-curable ink composition and reduce the tack of the surface of the cured film. In addition, since a cured film having stretchability can be formed by adjusting the content ratio of the monomer A) and the monomer B), the active energy ray-curable ink composition of the present invention is used. The cured film is a cured film having both stretchability and curability. Further, the content ratio is adjusted. Since the polyfunctional monomer represented by the following general formula (2) has a low odor, the monomer B) is contained in the active energy ray-curable ink composition. It does not become an active energy ray-curable ink composition having a large odor. Furthermore, since the monofunctional monomer represented by the following general formula (2) has a low viscosity, the viscosity of the active energy ray-curable ink composition is increased due to the inclusion of the monomer B). Absent. For this reason, the active energy ray-curable ink composition containing the monomer B) can be an active energy ray-curable ink composition that is preferable as an inkjet ink.

R ⁴ —CH═CR ¹ —COOR ² —O—CH═CH—R ³ (2)
(In the formula, R ¹ represents a hydrogen atom or a methyl group, R ² represents a divalent organic residue having 2 to 20 carbon atoms, and R ³ represents a hydrogen atom or a monovalent organic group having 1 to 11 carbon atoms. Represents an organic residue, and R ⁴ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.)

In the general formula (2), the divalent organic residue represented by R ² is a linear, branched or cyclic alkylene group having 2 to 20 carbon atoms which may be substituted, An optionally substituted alkylene group having 2 to 20 carbon atoms, an oxygen group having at least one of an ether bond and an ester bond, an optionally substituted divalent aromatic group having 6 or more carbon atoms, and a carbon number 11 or less optionally substituted divalent aromatic groups are preferred. Among these, an alkylene group having 2 to 6 carbon atoms, such as an ethylene group, an n-propylene group, an isopropylene group, and a butylene group, an oxyethylene group, an oxy n-propylene group, an oxyisopropylene group, and an oxybutylene group An alkylene group having 2 or more carbon atoms or an alkylene group having 9 or less carbon atoms having an oxygen atom due to an ether bond in a structure such as is suitably used.

In the general formula (2), the monovalent organic residue having 1 to 11 carbon atoms represented by R ³ is linear, branched or cyclic substituted having 1 to 11 carbon atoms. A good alkyl group, an optionally substituted aromatic group having 6 or more carbon atoms, and an optionally substituted aromatic group having 11 or less carbon atoms are preferable. Among these, an alkyl group having 1 to 2 carbon atoms, which is a methyl group or an ethyl group, an aromatic group having 6 or more carbon atoms such as a phenyl group and a benzyl group, or an aromatic group having 8 or less carbon atoms is preferably used. It is done.

  In the general formula (2), when each organic residue is an optionally substituted group, the substituent is divided into a group containing a carbon atom and a group not containing a carbon atom. First, when the substituent is a group containing a carbon atom, the carbon atom is counted in the carbon number of the organic residue. Examples of the group containing a carbon atom include, but are not limited to, a carboxyl group and an alkoxy group. Next, examples of the group not containing a carbon atom include, but are not limited to, a hydroxyl group and a halo group.

In the general formula (2), the hydrogen atom represented by R ⁴ or the monovalent organic residue having 1 to 4 carbon atoms is a hydrogen atom or a straight chain, branched or 1 to 4 carbon atoms Cyclic optionally substituted alkyl groups are preferred. Of these, hydrogen atoms are preferably used.

  Specific examples of the monomer B) represented by the general formula (2) include, for example, 2-vinyloxyethyl (meth) acrylate, 3-vinyloxypropyl (meth) acrylate, and 1-methyl-2 (meth) acrylate. -Vinyloxyethyl, 2-vinyloxypropyl (meth) acrylate, 4-vinyloxybutyl (meth) acrylate, 1-methyl-3-vinyloxypropyl (meth) acrylate, 1-vinyloxymethylpropyl (meth) acrylate, 2-methyl-3-vinyloxypropyl (meth) acrylate, 1,1-dimethyl-2-vinyloxyethyl (meth) acrylate, 3-vinyloxybutyl (meth) acrylate, 1-methyl-2- (meth) acrylate Vinyloxypropyl, 2-vinyloxybutyl (meth) acrylate, 6-vinyloxyhexyl (meth) acrylate, (Meth) acrylic acid p-vinyloxymethylphenylmethyl, (meth) acrylic acid m-vinyloxymethylphenylmethyl, (meth) acrylic acid o-vinyloxymethylphenylmethyl, (meth) acrylic acid 2- (vinyloxyethoxy) Ethyl, 2- (vinyloxyisopropoxy) ethyl (meth) acrylate, 2- (vinyloxyethoxy) propyl (meth) acrylate, 2- (vinyloxyethoxy) isopropyl (meth) acrylate, (meth) acrylic acid 2- (vinyloxyisopropoxy) propyl, (meth) acrylic acid 2- (vinyloxyisopropoxy) isopropyl, (meth) acrylic acid 2- (vinyloxyethoxyethoxy) ethyl, (meth) acrylic acid 2- (vinyloxy) Ethoxyisopropoxy) ethyl, (meth) acrylic acid 2- (vinyloxy) Isopropoxyethoxy) ethyl, 2- (vinyloxyisopropoxyisopropoxy) ethyl (meth) acrylate, 2- (vinyloxyethoxyethoxy) propyl (meth) acrylate, 2- (vinyloxyethoxyiso) (meth) acrylate Propoxy) propyl, (meth) acrylic acid 2- (vinyloxyisopropoxyethoxy) propyl, (meth) acrylic acid 2- (vinyloxyisopropoxyisopropoxy) propyl, (meth) acrylic acid 2- (vinyloxyethoxyethoxy) Isopropyl, 2- (vinyloxyethoxyisopropoxy) isopropyl (meth) acrylate, 2- (vinyloxyisopropoxyethoxy) isopropyl (meth) acrylate, 2- (vinyloxyisopropoxyisopropoxy) isopropyl (meth) acrylate , ( (Meth) acrylic acid 2- (vinyloxyethoxyethoxyethoxy) ethyl, (meth) acrylic acid 2- (vinyloxyethoxyethoxyethoxyethoxy) ethyl, (meth) acrylic acid 2- (isopropenoxyethoxy) ethyl, (meth) 2- (isopropenoxyethoxyethoxyethoxy) ethyl acrylate, 2- (isopropenoxyethoxyethoxyethoxy) ethyl (meth) acrylate, 2- (isopropenoxyethoxyethoxyethoxyethoxy) ethyl (meth) acrylate, (meth ) Polyethylene glycol monovinyl ether acrylate, and polypropylene glycol monovinyl ether (meth) acrylate.

  Among those described above, 2-vinyloxyethyl (meth) acrylate, 3-vinyloxypropyl (meth) acrylate, 1-methyl-2-vinyloxyethyl (meth) acrylate, 2-vinyloxypropyl (meth) acrylate, ( (Meth) acrylic acid 4-vinyloxybutyl, (meth) acrylic acid 5-vinyloxypentyl, (meth) acrylic acid 6-vinyloxyhexyl, (meth) acrylic acid 4-vinyloxymethylcyclohexylmethyl, (meth) acrylic acid p- Vinyloxymethylphenylmethyl, 2- (vinyloxyethoxy) ethyl (meth) acrylate, 2- (vinyloxyethoxyethoxy) ethyl (meth) acrylate, 2- (vinyloxyethoxyethoxyethoxy) ethyl (meth) acrylate Is preferred.

  Among these, since it has a low viscosity, a high flash point, and excellent curability of the active energy ray polymerizable monomer, (meth) acrylic acid 2- (vinyloxyethoxy) ethyl is preferable, and further, the odor is small, And since it is excellent in reactivity and adhesiveness, (meth) acrylic acid 2- (vinyloxyethoxy) ethyl is more preferable.

  Examples of 2- (vinyloxyethoxy) ethyl (meth) acrylate include 2- (2-vinyloxyethoxy) ethyl (meth) acrylate and 2- (1-vinyloxyethoxy) ethyl (meth) acrylate. Examples of 2- (vinyloxyethoxy) ethyl acrylate include 2- (2-vinyloxyethoxy) ethyl acrylate and 2- (1-vinyloxyethoxy) ethyl acrylate. Monomer B) may be used alone or in combination of two or more.

  Further, the content of the monomer B) is 20% by mass or less in the total amount of the active energy ray-curable ink composition, and preferably 17% by mass or less in the total amount of the active energy ray-curable ink composition. Most preferably, it is 15% by mass or less based on the total amount of the type ink composition. Since the content of the monomer B) is 20% by mass or less based on the total amount of the active energy ray-curable ink composition, stretchability can be imparted to the cured film. Even in this case, cracking of the cured film can be suppressed. Further, the content of the monomer B) is preferably 1% by mass or more in the total amount of the active energy ray-curable ink composition, more preferably 3% by mass or more in the total amount of the active energy ray-curable ink composition, Most preferably, it is 5% by mass or more based on the total amount of the active energy ray-curable ink composition.

[Polyfunctional monomers other than Monomer B)
Further, in addition to the monomer B), another polyfunctional monomer (polyfunctional monomer other than the polyfunctional monomer represented by the general formula (2)) may be appropriately added as long as the object of the present invention can be achieved.

  For example, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, hydroxypivalate neopentyl glycol diacrylate, polyalkylene glycol diacrylate, alkoxylated bisphenol A diacrylate, pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, Dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, 1,4-butanediol diacrylate, tetraethylene glycol diacrylate, dimethylol tricyclodecane diacrylate, trimethylol propane triacrylate, pentaerythritol triacrylate, glycerin triacrylate, And their modified number, modified species, structural differences It can be mentioned the (meth) acrylate.

  In addition, as the polyfunctional monomer other than the polyfunctional monomer represented by the general formula (2), a polyfunctional monomer capable of maintaining the viscosity of the active energy ray-curable ink composition to the extent that the ejection stability in inkjet can be improved, and / or Alternatively, it is preferable to use a polyfunctional monomer that does not increase the odor of the active energy ray-curable ink composition. An increase in viscosity and / or an increase in odor of the active energy ray-curable ink composition can be suppressed. The content of the active energy ray polymerizable monomer is preferably 10% by mass or less, more preferably 5% by mass or less, and still more preferably 1% by mass or less.

  In the present invention, a polymer component having no reactivity may be further contained. Examples of such polymer components include acrylic resins and cellulose acetate butyrate resins.

[Active energy ray polymerization initiator]
The active energy ray-curable ink composition may contain an active energy ray polymerization initiator as necessary. Active energy rays are energy rays that can trigger polymerization reactions such as radicals, cations, and anions. In addition to rays such as far ultraviolet rays, ultraviolet rays, near ultraviolet rays, and infrared rays, electromagnetic waves such as X-rays and γ rays, electron beams Any of proton beam, neutron beam and the like may be used, but curing by ultraviolet irradiation is preferable from the viewpoints of curing speed, availability of an irradiation apparatus, price, and the like. The active energy ray polymerization initiator is not particularly limited as long as it accelerates the polymerization reaction of the compound having an ethylenically unsaturated double bond in the active energy ray-curable ink composition by irradiation with active energy rays, Conventionally known active energy ray polymerization initiators can be used. Specific examples of active energy ray polymerization initiators include, for example, aromatic ketones containing thioxanthone, α-aminoalkylphenones, α-hydroxyketones, acylphosphine oxides, aromatic onium salts, organic peroxides Thio compounds, hexaarylbiimidazole compounds, ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having a carbon halogen bond, and alkylamine compounds.

  The amount of the active energy ray polymerization initiator may be an amount capable of appropriately starting the polymerization reaction of the active energy ray polymerizable monomer, and is 1.0% by mass or more based on the entire active energy ray curable ink composition. It is preferable that it is 3.0 mass% or more. Moreover, it is preferable that it is 20.0 mass% or less with respect to the whole active energy ray curable ink composition. In the present invention, the active energy ray polymerization initiator is not necessarily required. For example, when an electron beam is used as the active energy ray, the active energy ray polymerization initiator may not be used.

[Contents of Monomer A) and Monomer B)
The total content of the monomer A) and the monomer B) contained in the active energy ray-curable ink composition of the present invention is preferably 45% by mass or more based on the total amount of the active energy ray polymerizable monomer, and is active energy ray polymerizable. It is more preferably 53% by mass or more in the total amount of monomers, and further preferably 60% by mass or more in the total amount of active energy ray polymerizable monomers.

  The total content of monomer A) and monomer B) is 45% by mass or more based on the total amount of the active energy ray polymerizable monomer, thereby forming a cured film that enables both stretchability and tack reduction. An active energy ray-curable ink composition can be obtained.

  The total content of the monomer A) and the monomer B) contained in the active energy ray-curable ink composition of the present invention is preferably 90% by mass or less based on the total amount of the active energy ray polymerizable monomer, and is active energy ray polymerizable. It is more preferably 85% by mass or less in the total amount of monomers, and further preferably 80% by mass or less in the total amount of active energy ray polymerizable monomers.

  The total content of monomer A) and monomer B) is 45% by mass or more based on the total amount of the active energy ray polymerizable monomer, thereby forming a cured film that enables both stretchability and tack reduction. An active energy ray-curable ink composition can be obtained.

[Monomer content other than monomer A) and monomer B)]
In addition to “monomer A)” and “monomer B)” in the present invention, “monofunctional monomer other than the above-mentioned monomer A)” and “polyfunctional monomer other than the above-mentioned monomer B)” (1,6-hexanediol di) Acrylate, neopentyl glycol diacrylate, hydroxypivalate neopentyl glycol diacrylate, polyalkylene glycol diacrylate, alkoxylated bisphenol A diacrylate, pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol Hexaacrylate, 1,4-butanediol diacrylate, tetraethylene glycol diacrylate, dimethylol tricyclodecane diacrylate, trimer Roll propane triacrylate, pentaerythritol triacrylate, glycerin triacrylate, and (meth) acrylates (hereinafter simply referred to as “monomer B)” described above) having different numbers of modifications, different types of modifications, and different structures. In the case of an active energy ray curable ink composition containing at least one monomer selected from the group consisting of: The total monomer content of “polyfunctional monomers other than the above-described monomer B) is preferably 80% by mass or more in the total amount of active energy ray polymerizable monomers, More preferably 90% by mass or more, in the total amount of all active energy ray polymerizable monomers It is more preferably 5 mass% or more.

[Color material]
The active energy ray-curable ink composition of the present invention may contain a coloring material as necessary. By containing a color material, the cured film can be preferably used as a cured film for decoration. The coloring material may be any inorganic pigment or organic pigment that is usually used in conventional oil-based ink compositions, such as carbon black, cadmium red, molybdenum red, chrome yellow, and cadmium yellow. , Titanium yellow, titanium oxide, chromium oxide, viridian, titanium cobalt green, ultramarine blue, Prussian blue, cobalt blue, diketopyrrolopyrrole, anthraquinone, benzimidazolone, anthrapyrimidine, azo pigment, phthalocyanine pigment, quinacridone Pigment, isoindolinone pigment, dioxazine pigment, selenium pigment, perylene pigment, perinone pigment, thioindigo pigment, quinophthalone pigment, metal complex pigment, aluminum paste, silica, calcium carbonate, magnesium carbonate Beam, clay, precipitated barium sulfate, pearl pigments, and the like.

  A preferable dispersed particle diameter of the pigment of the active energy ray-curable ink composition of the present invention is preferably 10 nm or more in terms of a volume average particle diameter by a laser scattering method. In addition, a preferable dispersed particle diameter of the pigment of the active energy ray-curable ink composition of the present invention is preferably 300 nm or less in terms of volume average particle diameter by a laser scattering method. By setting the volume average particle size to 10 nm or more, 300 nm or less, or 10 nm or more and 300 nm or less, light resistance can be maintained and dispersion can be stabilized. Since it is possible to reduce the possibility of head clogging or ejection bending when ink is ejected, a more preferable active energy ray-curable ink composition can be obtained.

  In the present invention, when a pigment is used, its content may be adjusted as appropriate. Although it varies depending on the type of pigment, the content of the pigment in the total amount of the active energy ray-curable ink composition is preferably 0.1% by mass or more in the case of an organic pigment from the viewpoint of achieving both dispersibility and coloring power. 0.2 mass% or more is more preferable. In the case of an organic pigment, 20.0% by mass or less is preferable, and 10.0% by mass or less is more preferable in terms of achieving both dispersibility and coloring power. In the case of an inorganic pigment, 1.0% by mass or more is preferable, and 5.0% by mass or more is more preferable from the viewpoint of achieving both dispersibility and coloring power. Moreover, in the case of an inorganic pigment, 40.0 mass% or less is preferable, and 20.0 mass% or less is more preferable.

[Dispersant]
The active energy ray-curable ink composition of the present invention may contain a dispersant as necessary. Examples of the dispersant include a polymer dispersant. The main chain of this polymer dispersant is made of polyester, polyacrylic, polyurethane, polyamine, polycaprolactone, etc., and the polymer dispersant has amino groups, carboxyl groups, sulfone groups, hydroxyl groups, etc. as side chains. It is preferable to have a polar group or a salt thereof.

  A preferred polymer dispersant is a polyester-based dispersant. Specific examples include “Solsperse 33000”, “Solsperse 32000”, “Solsperse 24000” manufactured by Nippon Lubrizol; “Disperbyk168” manufactured by BYK Chemie, Inc .; manufactured by Ajinomoto Fine Techno Co. “Ajisper PB821”, “TEGO Dispers 685” manufactured by Evonik Japan, and the like can be mentioned.

[Surface conditioner]
The active energy ray-curable ink composition of the present invention may further contain a surface conditioner. Although it does not specifically limit as a surface conditioning agent, As a specific example, "BYK-306", "BYK-333", "BYK-371", "BYK-377", and Evonik Degussa Japan by the Big Chemie company which have dimethylpolysiloxane are included. “TegoRad2010”, “TegoRad2100”, “TegoRad2200N”, “TegoRad2300”, and the like manufactured by the company are listed.

  The content of the surface conditioner is preferably 0.1% by mass or more based on the total amount of the ink composition. The content of the surface conditioner is preferably 5.0% by mass or less with respect to the total amount of the ink composition. By setting the content to 0.1% by mass or more or 5.0% by mass or less, the ink composition has preferable wettability with respect to the thermoplastic resin substrate and the like, and recording is performed on the substrate (image formation). In this case, the active energy ray-curable ink composition can be spread and spread without causing repellency.

[Delustering agent]
The active energy ray-curable ink composition of the present invention may contain a matting agent as necessary. As the matting agent, for example, various powders such as silica, alumina, calcium carbonate and the like can be used. Matting agents may be used alone or in combination of two or more.

[Other additives]
Moreover, the active energy ray-curable ink composition of the present invention may contain various additives such as a plasticizer, a polymerization inhibitor, a light stabilizer, and an antioxidant as other additives. The solvent can be added within a range that achieves the object of the present application.

  In addition, the surface tension of the active energy ray-curable ink composition of the present invention is preferably 20 mN / m or more at 40 ° C. from the viewpoint of inkjet dischargeability and discharge stability. Further, the surface tension at 40 ° C. is preferably 40 mN / m or less.

<Method for producing active energy ray-curable ink composition>
The method for producing the active energy ray-curable ink composition of the present invention is not particularly limited, and a conventionally known method can be used. In addition, when using a granular color material, a granular matting agent, etc., use a disperser to disperse with an active energy ray polymerizable monomer, a dispersing agent, etc., and then, if necessary, an active energy ray polymerization initiator. The active energy ray-curable ink composition of the present invention can be obtained by adding a surface conditioner and the like, stirring uniformly, and further filtering through a filter.

<Method for producing laminate>
The laminate of the present invention is produced by printing the active energy ray-curable ink composition on a substrate, preferably by an ink jet method, and then curing with an active energy ray. The printing can be performed by a conventionally known method such as an offset printing method, a gravure printing method, a spray method, or a brush coating method, but an inkjet method is preferable in that it can cope with a wide variety of small lots. Moreover, when printing by an inkjet system, you may print in the state which heated the inkjet head, and may print with room temperature. Since the active energy ray-curable ink composition of the present invention contains the monomer A) and the monomer B) which are extremely low in viscosity even at room temperature, the low energy active energy ray is also used in the room temperature environment. A curable ink composition can be obtained. Therefore, it is possible to print on the substrate without heating the inkjet head.

  An image can be formed on a substrate using the active energy ray-curable ink composition of the present invention. For example, an ink set of an active energy ray-curable ink composition containing color materials of various shades is prepared, and after printing by an ink jet method, the ink composition is cured to display various images on the substrate. Can be formed. An active energy ray-curable ink composition for forming such a cured film and an image forming method for forming an image on a substrate are also within the scope of the present invention. In the present specification, the term “image” means a decorative image that can be recognized through vision including letters, diagrams, figures, symbols, photographs, etc. composed of a single color or a plurality of colors. Also included are patterns made of stone, cloth, sand, geometric patterns, letters, etc.

[Base material]
The substrate is not particularly limited, and for example, any of a coated paper, a non-coated paper, an absorbent body such as a fabric, and a non-absorbent substrate can be used. Specifically, as non-coated paper, renewed paper, medium-quality paper, high-quality paper, and coated paper as coated paper, art paper, cast paper, lightweight coated paper, fine coated paper, fabric, etc. Examples of the body include cotton, synthetic fabric, silk, hemp, fabric, non-woven fabric, leather, etc. Examples of the non-absorbent substrate include polyester resin, polypropylene synthetic paper, vinyl chloride resin, polyimide resin, metal, metal Examples thereof include foil-coated paper, glass, synthetic rubber, and natural rubber. Further, the active energy ray-curable ink composition of the present invention is not limited to the case where a non-flexible base material such as metal is used as a recording medium, and the flexible base material is a recording medium. Even when it is used as, it is possible to effectively suppress cracking of the cured film due to bending of the flexible substrate. Note that “having flexibility” means that the radius of curvature is usually 1 m, preferably 50 cm, more preferably 30 cm, still more preferably 10 cm, and particularly preferably 5 cm at room temperature. .

[Curing with active energy rays]
The active energy ray for forming a cured film (hereinafter, sometimes referred to as “cured film”) obtained by curing the active energy ray-curable ink composition of the present invention is light having a wavelength region of 200 nm or more. Preferably, light having a wavelength region of 250 nm or more is more preferable. The active energy ray for forming the cured film is preferably light having a wavelength region of 450 nm or less, and more preferably light having a wavelength region of 430 nm or less. The light source is not particularly limited, and examples thereof include a high pressure mercury lamp, a metal halide lamp, a low pressure mercury lamp, an ultrahigh pressure mercury lamp, an ultraviolet laser, sunlight, and an LED lamp. By using these light sources and irradiating active energy rays so that the integrated light quantity is 100 mJ / cm ² or more, preferably 200 mJ / cm ² or more, the ink composition can be cured instantaneously.

  The thickness of the cured film is preferably 1 μm or more. Moreover, it is preferable that the thickness of a cured film is 100 micrometers or less. By setting the thickness to 1 μm or more, the color density of the cured film containing the coloring material is not decreased, and physical properties such as a decrease in design properties, decorativeness, adhesion, and extensibility are improved. By setting the thickness to 100 μm or less, the ink composition can be sufficiently cured in a shorter time when the ink composition is irradiated with active energy rays, which is more preferable.

  The cured film thickness was measured by applying the active energy ray-curable ink composition of the present invention to a PET film (A4300, manufactured by Toyobo Co., Ltd.) under the same coating conditions as the prepared cured film, and then obtaining the cured film. The film thickness can be measured with a micrometer. In this specification, the thickness of the cured film is 10 locations per sample, and the average value of these is the thickness (the average thickness). The same applies to the protective layer and primer described later.

[Curing film]
The cured film formed from the active energy ray-curable ink composition of the present invention can be used as a decorative layer as long as it contains a coloring material as described above, but it can be added without adding a coloring material. If it discharges on a decoration layer, this cured film itself can also be utilized as an overcoat layer which protects a cured film. Further, it can be used as a primer layer for improving the adhesion between the substrate surface and the cured film. An active energy ray-curable ink composition that forms such a cured film is also within the scope of the present invention.

  The active energy ray-curable ink composition of the present invention may be used to form a decorative layer, an overcoat layer, or a primer layer independently only with a cured film formed by the active energy ray-curable ink composition of the present invention. Or a combination of these layers. For example, the active energy ray-curable ink composition of the present invention in which a coloring material is added to the active energy ray-curable ink composition of the present invention to form a decorative layer, and no coloring material is added on the decorative layer. An overcoat layer can also be formed by discharging. Moreover, the cured film formed with the active energy ray-curable ink composition of the present invention can also be used in combination with a decorative layer, overcoat layer or primer layer formed with a conventionally known ink composition. For example, when the active energy ray-curable ink composition of the present invention is used as a decorative layer, an overcoat layer can be formed on the decorative layer using a conventionally known overcoat composition.

  When an overcoat layer or a primer layer is formed on a substrate, any method may be used to form these layers. For example, spray coating, towel, sponge, nonwoven fabric, tissue coating, etc. , Dispenser, brush coating, gravure printing, flexographic printing, silk screen printing, inkjet, thermal transfer method, etc. may be used.

[Overcoat layer]
For the purpose of further improving the durability of the laminate, an overcoat layer comprising a conventionally known overcoat agent or the ink composition of the present invention is used as an overcoat agent on the surface of the cured film of the ink composition of the present invention. An overcoat layer formed by use may be further formed. The overcoat layer is not limited to being formed on the surface of the layer made of the cured film of the ink composition, but may be formed directly on the surface of the base material, or formed on the surface of the base material. You may form in the surface of the primer layer mentioned later.

  As the overcoat agent, the active energy ray-curable ink composition of the present invention can be preferably used. By using the active energy ray-curable ink composition of the present invention, excellent curability and stretchability can be realized. Furthermore, for example, when an overcoat layer is formed with an overcoat agent using the active energy ray-curable ink composition of the present invention on a cured film using the active energy ray-curable ink composition of the present invention, the curing is performed. Since the film and the overcoat layer have the same composition, their adhesion is extremely high. Therefore, it is particularly preferable to use the active energy ray-curable ink composition of the present invention as an overcoat agent for the cured film of the active energy ray-curable ink composition of the present invention.

  The thickness of the overcoat layer is preferably 1 μm or more. The thickness is preferably 1 μm or more because the cured film can be appropriately protected. The overcoat layer preferably has a thickness of 100 μm or less. The thickness is preferably 100 μm or less because the drying time is shortened to form the overcoat layer and the productivity is excellent.

  Further, when the overcoat layer is formed, the design properties are imparted to the overcoat layer by adjusting the conditions such as the discharge amount of the ink composition and the time from the discharge of the ink composition to the irradiation of the active energy ray. You can also. For example, it is also possible to form a three-dimensional and highly designed overcoat layer with irregularities by making the surface matt or glossy, or by making the surface film thickness non-uniform. Specifically, after discharging the ink composition, the surface can be made glossy by irradiating active energy rays after a predetermined time has elapsed, and the surface can be quickly irradiated by irradiating active energy rays after discharging. It can be matte. In addition, unevenness can be imparted by increasing / decreasing the discharge amount per time depending on the discharge location, and unevenness difference from other locations can be achieved by repeating the ejection of the ink composition and the irradiation of active energy rays at the same location. Can also be given. An active energy ray-curable ink composition for forming such a cured film and an image forming method for forming an uneven image are also within the scope of the present invention. Such an overcoat layer is desirably formed by an ink jet method from the viewpoint of easy condition adjustment. The concavo-convex image is not necessarily limited to what is visually recognized, and includes, for example, a colorless cured film or a cured film having a single color or a plurality of colors, as long as it has a concavo-convex shape. .

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention does not receive a restriction | limiting at all by these description.

<Preparation of Ink Composition (Examples 1-20, Comparative Examples 1-5)>
Table 1 shows mass parts of the active energy ray polymerizable monomer, active energy ray polymerization initiator, photopolymerization initiator, polymer dispersant, and pigment of the ink composition in the total amount of the ink composition in Examples and Comparative Examples. 2 (Examples) and Table 3 (Comparative Examples).

  In Tables 1 to 3, 2- (2-vinyloxyethoxy) ethyl acrylate corresponds to VEEA-AI (monomer B) manufactured by Nippon Shokubai Co., Ltd. ).

  In Table 3, PO-modified (× 2) neopentyl glycol diacrylate corresponds to a bifunctional monomer other than SR9003 (monomer B) manufactured by Arkema Co., Ltd. ).

  In Table 3, neopentyl glycol diacrylate corresponds to a bifunctional monomer other than SR247 (monomer B) manufactured by Arkema. ).

  In Tables 1-3, 4- (1,1-dimethylethyl) cyclohexyl acrylate corresponds to a monofunctional monomer other than SR217 (monomer A) manufactured by Arkema Co., Ltd. ).

  In Tables 1 to 3, tetrahydrofurfuryl acrylate is biscoat # 150 (monomer A) manufactured by Osaka Organic Chemical Industry Co., Ltd., and corresponds to monomer A1). ).

  In Tables 1-3, 5-ethyl-1,3-dioxan-5-ylmethyl acrylate is biscoat # 200 (monomer A) manufactured by Osaka Organic Chemical Industry Co., Ltd., and corresponds to monomer A2). ).

  In Tables 1 to 3, (2-methyl-2-ethyl-1,3-dioxolan-4-yl) methyl acrylate corresponds to MEDOL-10 (monomer A) manufactured by Osaka Organic Chemical Industry. ).

  In Table 3, isobornyl acrylate corresponds to a monofunctional monomer other than IXBA (monomer A) manufactured by Osaka Organic Chemical Industry. ).

  In Table 3, N-vinyl-ε-caprolactam corresponds to a monofunctional monomer other than V-CAP (monomer A) manufactured by ISP. ).

  In Table 2, the photopolymerization initiator A is bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, which is IRGACURE 819 manufactured by BASF.

  In Tables 1 to 3, the photopolymerization initiator B is diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide, which is IRGACURE TPO manufactured by BASF.

  In Table 2, photopolymerization initiator C is 2,4-diethylthioxanthen-9-one, which is DOUBLECURE DETX manufactured by Mitsubishi Corporation.

  In Tables 1 to 3, the photopolymerization inhibitor A is phenothiazine and is ANTAGE TDP manufactured by Kawaguchi Chemical Co., Ltd.

  In Table 2, the photopolymerization inhibitor B is Genorad22 manufactured by RAHN.

  In Tables 1 to 3, the surface conditioner is silicone polyether acrylate, which is Tegorad 2010 manufactured by Evonik Degussa Japan.

  In Tables 1-3, the polymer dispersant A is Solsperse 32000 manufactured by Nippon Lubrizol Corporation.

  In Table 2, the polymer dispersant B is TEGO Dispers 685 manufactured by Evonik Japan Co., Ltd.

  In Tables 1 to 3, Pigment A is C.I. I. Pigment Blue 15: 3, which is LIONOL BLUE FG7400G manufactured by Toyocolor Co., Ltd.

  In Tables 1 to 3, pigment B is carbon black, which is NEROX 56000 manufactured by Orion Engineered Carbons.

  In Tables 1 to 3, Pigment C is titanium oxide and is TITANIX JR407 manufactured by Teika Corporation.

  In Table 2, pigment D is C.I. I. Pigment Yellow 150, manufactured by LANXESS and Levasscreen Yellow.

  In Table 2, Pigment E is C.I. I. Pigment RED 122, a FASTOGEN Super Magenta RIS manufactured by DIC Corporation.

  In Tables 1 to 3, “monomer A) / ink composition” means the content (mass%) of monomer A) in the total amount of the active energy ray-curable ink composition.

  In Tables 1 to 3, “monomer B) / ink composition” means the content (mass%) of monomer B) in the total amount of the active energy ray-curable ink composition.

  In Tables 1 to 3, “monomer / ink composition” means the content (mass%) of the active energy ray-polymerizable monomer in the total amount of the active energy ray-curable ink composition.

  In Tables 1 to 3, “monofunctional monomer / monomer” means the content (mass%) of the monofunctional monomer in the total amount of the active energy ray polymerizable monomer.

[Preparation of ink composition]
Each monomer material was mixed so that it may become a ratio shown in Tables 1-3, and it stirred at room temperature (20-25 degreeC) for 1 hour. Thereafter, it was confirmed that there was no undissolved residue. Then, it filtered using the membrane filter and prepared the ink composition of an Example and a comparative example.

<Viscosity measurement test>
The viscosity of the ink compositions of Examples and Comparative Examples was measured. Specifically, the viscosity was measured at 25 ° C. using a viscosity measurement tester (AMVn manufactured by Anton Paar) based on JIS Z 8803: 2001. The measurement results are shown in Tables 1 to 3 (in the table, viscosity and notation, the unit is Pa · s).

<Odor test>
An odor test was performed on the ink compositions of Examples and Comparative Examples. Specifically, the ink composition was diluted with polyethylene glycol (ink composition: polyethylene glycol = 1: 1000), five subjects were smelled, and sensory evaluation was performed according to the following criteria. When the majority evaluation is 3, “○” is indicated. When the majority evaluation is 1 or 2, “X” is indicated (indicated in the table as “odor”). The measurement results are shown in Tables 1-3.
Evaluation 3: There is no odor.
Evaluation 2: There is a slight odor.
Evaluation 1: There is an unpleasant odor.
[Manufacture of laminates]

A laminate was produced using vinyl chloride having a thickness of 80 μm as a base material. Each sample was produced on the surface of the base material by the inkjet method using the composition constituting the cured film shown in Tables 1 to 3. Then, the ink composition is cured using a UV-LED lamp (wavelength 385 nm) under the conditions of an integrated light amount of 100 mJ / cm ² and a peak illuminance of 1500 mW / cm ² (both UV-V wavelength region (375 to 415 nm)). did. Measurement of the integrated light quantity and peak illuminance was performed using an ultraviolet light quantity meter UV Power Pack 2 (manufactured by EIT). This produced the cured film.

<Extension test>
About the laminated body of an Example and a comparative example, 150% of the original length of a laminated body is obtained at 25 degreeC as a test piece of a dumbbell-shaped No. 6 form (JIS K6251-5) after a laminated body is produced for one day. It was confirmed whether or not substantial cracking of the cured film occurred when the laminate was stretched once at a strain rate of 100 mm / min within the range up to 1.5 times. Those where substantial cracks did not occur were indicated as “◯”, and those where they were generated were indicated as “X”. The evaluation results are shown in Tables 1 to 3 (in the table, expressed as extensibility). Here, the substantial crack means a crack in which a crack (crack) has progressed by 50% or more of the length of the sample piece.

<Curing test>
The curability was evaluated by rubbing the cured film with a cotton swab and checking for the presence or absence of color transfer. The results are shown in Tables 1-3. When no color transfer is observed with a cotton swab, “◎”, when there is almost no color transfer with a cotton swab, “○”, when color transfer is observed with a cotton swab, and substantially exceeds the allowable range Was marked “x” (indicated as “curability” in the table).

<Tack test>
Evaluation of tack was performed at room temperature.
The laminate was placed at room temperature, and the cured film was touched with a finger to check for stickiness. The results are shown in Tables 1-3. The case where there was no stickiness was designated as “◎”, the case where there was a slight stickiness but was substantially within the allowable range, “◯”, and the case where stickiness was strong and substantially exceeded the allowable range was indicated as “X” (in the table, “Tack”.)

<Evaluation results>
From Tables 1 to 3, the active energy ray-curable ink compositions of the examples are active energy ray-curable ink compositions capable of forming a cured film that enables both stretchability and tack reduction. I understand that.

  In particular, the active energy ray-curable ink compositions of Examples 1 to 6 and 9 to 20 in which the monomer A) includes the monomer A1) and the monomer A2), which are two types of monofunctional monomers having different molecular structures, In all tests, the evaluation was “◯”, and the active energy capable of forming a cured film that enables both the stretchability and the reduction of tack to be higher than those of Examples 7 and 8 in which monomer A) is alone. It turns out that it is a line curable ink composition.

  On the other hand, the active energy ray-curable ink composition of Comparative Example 1 using neopentyl glycol diacrylate, which is a bifunctional monomer that is not monomer B), instead of monomer B), or PO modification, which is a bifunctional monomer that is not monomer B) (× 2) The active energy ray-curable ink composition of Comparative Example 2 using neopentyl glycol diacrylate has poor stretchability or poor tack, and can achieve both balance of stretchability and reduction of tack. It can be seen that a cured film is not formed.

  Moreover, the active energy ray-curable type of Comparative Example 3 using isobornyl acrylate (IBXA) and N-vinyl-ε-caprolactam (V-CAP), which are monofunctional monomers that are not monomer A), instead of monomer A) In the ink composition, since the crack of the cured film occurs in the stretchability test, it can be seen that a cured film capable of achieving both stretchability and tack reduction cannot be formed.

  Comparison in which the content of monomer A) and monomer B) is not within the scope of the present invention (monomer A) is 40% by mass or more and the total content of monomer B) is 20% by mass or less). In the active energy ray-curable ink composition of Example 4, since the cured film was cracked in the stretchability test, it was not possible to form a cured film that could achieve both stretchability and tack reduction. I understand.

  Moreover, it turns out that the active energy ray hardening-type ink composition of the comparative example 5 which does not contain a bifunctional monomer is inferior in sclerosis | hardenability in the sclerosis | hardenability test, and has not formed the cured film which has sufficient sclerosis | hardenability.

Claims (10)

As an active energy ray polymerizable monomer,
Monomer A): a monofunctional monomer represented by the following general formula (1),
Monomer B): a polyfunctional monomer represented by the following general formula (2),
The total content of the monomer A) is 40% by mass or more based on the total amount of the active energy ray-curable ink composition,
Ri total content der 20 wt% or less in the active energy ray-curable ink composition the total amount of the monomers B),
The monomer A) includes at least a monomer A1) and a monomer A2) which are two types of monofunctional monomers having different molecular structures, and the glass transition point of the monomer A1) is higher than the glass transition point of the monomer A2). Is also small,
An active energy ray-curable ink composition in which a content ratio of the monomer A1) to the monomer A2) is 1.3 to 16 in terms of a mass ratio of monomer A1) / monomer A2) .
An active energy ray-curable ink composition.

(In the formula, R ¹ is a functional group having a 5- or 6-membered saturated heterocyclic structure in which the hetero atom is composed solely of oxygen. R ² represents an alkylene group having 1 to 5 carbon atoms. R ³ Represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.)
R ⁴ —CH═CR ¹ —COOR ² —O—CH═CH—R ³ (2)
(In the formula, R ¹ represents a hydrogen atom or a methyl group, R ² represents a divalent organic residue having 2 to 20 carbon atoms, and R ³ represents a hydrogen atom or a monovalent organic group having 1 to 11 carbon atoms. Represents an organic residue, and R ⁴ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.) Glass transition point, the active energy ray-curable ink composition according to small claim 1 25 ° C. or higher than the glass transition point of the monomer A2) of the monomer A1). The monomer A1) has a glass transition point of −5 ° C. or less,
The active energy ray-curable ink composition according to claim 2 , wherein the monomer A2) is a monomer having a glass transition point of 25 ° C or higher. The monomer A1) is at least one monomer selected from the group consisting of tetrahydrofurfuryl acrylate and a monomer represented by the following general formula (3):

(In the formula, R ^1-1 and R ^1-2 are each independently a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms or a phenyl group, and R ^1-1. And R ^1-2 may be bonded to form a ring, R ² represents an alkylene group having 1 to 5 carbon atoms, R ³ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Show.)
The active energy ray-curable ink composition according to any one of claims 1 to 3 , wherein the monomer A2) is a monomer represented by the following general formula (4).

(In the formula, R ^1-1 and R ^1-2 each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R ² represents an alkylene group having 1 to 5 carbon atoms. R ³ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ⁴ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.) Further, the active energy ray-curable ink composition according to any one of claims 1 containing alkylcycloalkyl acrylate 4. The active energy ray-curable ink composition according to any one of claims 1 to 5 , which is used as an inkjet ink. The active energy ray-curable ink composition according to any one of claims 1 to 6, formed as a cured film having a thickness of 10μm in the thickness 80μm on the vinyl chloride sheet, a cured film formed by this cured film is formed When a base material is subjected to a tensile test at 25 ° C. and a tensile speed of 10 mm / min as a test piece of dumbbell-shaped No. 6 (JIS K6251-5), the cured film breakage point at which the cured film breaks. An active energy ray-curable ink composition having an elongation percentage of 50% or more. A laminate in which an ink cured film layer that is a cured film of the active energy ray-curable ink composition according to any one of claims 1 to 7 is formed on a substrate. Image forming method of forming an image and / or topographic image on a substrate using an active energy ray-curable ink composition according to any one of claims 1 to 7. The manufacturing method of the printed matter which forms an image and / or an uneven | corrugated image on a base material using the active energy ray hardening-type ink composition in any one of Claim 1 to 7 .