JP5646427B2 - Ink composition, image forming method and printed matter - Google Patents

Description

  The present invention relates to an ink composition, an image forming method using the ink composition, and a printed matter obtained by the image forming method.

  As an image recording method for forming an image on a recording medium such as paper based on an image data signal, there are an electrophotographic method, a sublimation type and a melt type thermal transfer method, an ink jet method and the like. For example, the ink jet method can be implemented with an inexpensive apparatus, and the ink can be used efficiently and the running cost can be achieved because the image is directly formed on the recording medium by ejecting the ink only to the required image portion. Is cheap. Furthermore, there is little noise and it is excellent as an image recording method.

According to the ink jet method, printing is possible not only on plain paper but also on non-water-absorbing recording media such as plastic sheets and metal plates, but speeding up and high image quality when printing are important issues. The time required for drying and curing of the droplets after printing has the property of greatly affecting the productivity of the printed matter and the sharpness of the image obtained by printing.
As one of the ink jet methods, there is a recording method using an ink for ink jet recording that can be cured by irradiation with active energy rays. According to this method, the productivity of printing is improved and a sharp image can be formed by irradiating an active energy ray immediately after ink ejection or after a certain period of time to cure ink droplets.

  As an example of an ink composition that can be cured by irradiation with active energy rays, Patent Document 1 discloses that a partial structure selected from a fluorine-substituted hydrocarbon group, a siloxane skeleton, and a long-chain alkyl group and a radically polymerizable group are side chains. Ink compositions containing a polymer having improved flexibility, blocking resistance, dischargeability, processability (particularly embossing processability, vacuum forming processability) and the like are disclosed.

JP 2010-70692 A

  However, in the above technique, the processability under stricter conditions, that is, the image area even under conditions where a larger stress is applied to the image area than in normal embossing and molding processes such as drilling. It has not been studied at all to suppress cracking of the steel and impart higher workability.

  The present invention has been made in view of the above, and can achieve both the hardness and flexibility of the image portion within an appropriate range. In particular, the occurrence of cracks is suppressed even when a larger stress such as drilling is applied. It is an object of the present invention to provide an ink composition capable of forming a printed image, an image forming method using the ink composition, and a printed matter excellent in processing suitability.

Specific means for achieving the above object are as follows.
<1> (A) Polymer having urethane bond or urea bond in main chain structure and having polymerizable group in side chain, (B) polymerizable compound other than (A), and (C) polymerization initiation And (A) the polymer having any one of (a1) a fluorine-substituted hydrocarbon group and (a2) a group containing a siloxane structure at at least one end of the main chain structure. It is a thing.

<2> The ink composition according to <1>, wherein the polymerizable group of the polymer (A) is a (meth) acrylic acid ester group.

< 3 > The ink composition according to <1> or < 2>, wherein the polymer (A) has (a2) a group containing a siloxane structure at at least one end of the main chain structure.

< 4 > The content of the polymer (A) in the total content of the polymer (A) and the polymerizable compound (B) is 0.2 % by mass to 10% by mass. <1> to < 3 > The ink composition according to any one of the above.

< 5 > The ink composition according to any one of <1> to < 4 >, wherein the content of the polymerizable group in the polymer (A) is 0.3 mmol / g or more.

< 6 > The ink composition according to any one of <1> to < 5 >, wherein the content of the monofunctional monomer in the polymerizable compound (B) is 60 % by mass to 100% by mass.

< 7 > (D) The ink composition according to any one of <1> to < 6 >, further including a colorant.

< 8 > The ink composition according to any one of <1> to < 7 >, which is for inkjet recording.

< 9 > An image forming method including an ink application step of applying the ink composition according to any one of <1> to < 8 > onto a recording medium by an inkjet method.

< 10 > A printed matter obtained by the image forming method according to < 9 >.

  According to the present invention, the hardness and flexibility of the image portion can be compatible within an appropriate range, and an image in which cracking of the image portion is suppressed even when a larger stress such as drilling is applied is formed. Can be provided, an image forming method using the same, and a printed matter excellent in processing suitability.

[Ink composition]
The ink composition of the present invention is described in detail below. (A) A polymer containing a urethane bond or a urea bond in the main chain structure and having a polymerizable group in the side chain, and (B) other than the above (A) And (C) a polymerization initiator, and the polymer (A) includes (a1) a fluorine-substituted hydrocarbon group and (a2) a siloxane structure at at least one end of the main chain structure. group, and (a3) of the ink composition is a polymer having any one long chain alkyl group, of, as the (a) polymer, at least one end of the previous SL backbone structures, (a1) fluorine It is an ink composition comprising a polymer having any one of a substituted hydrocarbon group and (a2) a group containing a siloxane structure .
Although the action of the ink composition is not clear, at least one end of the main chain structure in the ink composition is (a1) a fluorine-substituted hydrocarbon group, (a2) a group containing a siloxane structure, and (a3) length. By including the polymer (A) having any one of the chain alkyl groups, the polymer (A) is oriented on the surface of the image formed by the ink composition, and the polymerizable group and the highly cohesive urethane ( (Urea) The polymer having a structure is unevenly distributed on the surface, so that the surface hardness is improved, and the image formed due to the physical properties of the polymer having a main chain with excellent flexibility is hardly cracked and has excellent processing suitability. It will be a thing. Furthermore, the polymer (A) has the specific group at the end of the main chain structure, so that it can be contained in the ink composition as compared with a polymer having the same specific group at another site, for example, a side chain. It is considered that it also has an advantage that the effect of uneven distribution on the surface is easily obtained.
Hereinafter, the essential components constituting the ink composition of the present invention will be described. In this specification, when referring to “acrylate” and / or “methacrylate”, it refers to “(meth) acrylate” and “acryl” and / or “methacryl”. May be described respectively.

<(A) Polymer>
(A) The polymer is a polymer ( A) containing a urethane bond or a urea bond in the main chain structure and having a polymerizable group in the side chain, and at least one terminal of the main chain structure, (a1) It has one of a fluorine-substituted hydrocarbon group, (a2) a group containing a siloxane structure, and (a3) a long-chain alkyl group . In addition, the (A) polymer contained in the ink composition of the present invention includes (a1) a fluorine-substituted hydrocarbon group and (a2) siloxane at at least one terminal of the main chain structure which is a preferred embodiment of the (A) polymer. A polymer having any one of the groups containing the structure . First, (a ) the fluorine-substituted hydrocarbon group, (a2) a group containing a siloxane structure, and (a3) a long-chain alkyl group that the polymer (A) has at least one terminal of the main chain structure will be described.
Hereinafter, the polymer (A) is also referred to as “surface segregation polymer” as appropriate.

((A1) Fluorine-substituted hydrocarbon group)
The fluorine-substituted hydrocarbon group in the (A) polymer (surface segregation polymer) in the present invention may be a hydrocarbon group substituted with at least one fluorine atom. For example, at least one hydrogen atom in the alkyl group The fluoroalkyl group substituted by the fluorine atom is mentioned, The perfluoroalkyl group which substituted all the hydrogen of the alkyl group by the fluorine is more preferable.

  As an alkyl group, C1-C20 is preferable, C4-C10 is more preferable, and C6-C8 is still more preferable.

Specific embodiments of the fluorine-substituted hydrocarbon group in the present invention will be described.
Preferred fluorine-substituted hydrocarbon groups that the surface segregation polymer has at the main chain terminals include those represented by the following general formula I.

In the above (general formula I), R ² and R ³ each represent a hydrogen atom or an alkyl group, X represents a single bond or a divalent linking group, m is an integer of 0 or more, and n is an integer of 1 or more. Represents. Y ¹ represents a hydrogen atom or a fluorine atom.
When m is 2 or more, functional groups on adjacent carbons (that is, R ² and R ³ bonded to adjacent carbons) may be bonded to form an aliphatic ring. . Moreover, * represents the position linked to the main chain end of the polymer.

  Among the groups represented by the above (General Formula I), those in which (n) in (General Formula I) is 1 to 20 are preferable, 1 to 8 are more preferable, and 4 or 6 is particularly preferable. .

The alkyl group represented by R ² and R ³ in (General Formula I) is preferably an alkyl group having 1 to 4 carbon atoms, and may have a linear structure or a branched structure. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, and the like, preferably a hydrogen atom or a methyl group, more preferably hydrogen. Is an atom.

In (General Formula I), when X is a single bond, it means that the polymer main chain and the carbon atom to which R ² and R ³ are bonded are directly connected.
Moreover, as a bivalent coupling group in case X represents a bivalent coupling group, -O-, -S-, -N (R < ⁴ >)-, etc. are mentioned. Among these, -O- is more preferable.
Here, R ⁴ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. The alkyl group may be a linear structure or a branched structure, and examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a tert-butyl group. Preferably, they are a hydrogen atom and a methyl group.

  In (General Formula I), m is preferably an integer of 2 to 8, and 2 is particularly preferable.

A specific method for introducing the structure represented by the above (general formula I) into the end of the main chain of the polymer (A) will be described later. A commercially available compound having a structure may be applied.
As the compound for introducing the terminal structure of the general formula I, an alcohol compound, an amine compound, a thiol compound, or the like including the structure represented by the (general formula I) can be used. Among these, the alcohol compound (Preferably monovalent) is preferred. Specific examples include 2- (perfluorohexyl) ethanol, (perfluorobutyl) methanol, and 3- (perfluorobutyl) propanol. Among these, 2- (perfluorohexyl) ethanol is preferable.

((A2) group containing a siloxane structure)
The group containing a siloxane structure contained in the polymer (A) (surface segregation polymer) in the present invention is not particularly limited as long as it has a “—Si—O—Si—” structure. Preferably has a group represented by the following general formula (a2-1) at the end of the main chain of the polymer (A).

In the general formula ((a2-1), Rs ¹ , Rs ^2, and Rs ³ are each independently an alkyl group having 1 to 4 carbon atoms, an aryl group, or a monovalent substitution represented by the following formula (S). X represents —O—, —S—, or —N (R ^S1 ) —, R ^S1 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and W represents a divalent group. Represents a linking group, * represents the position of linking to the main chain end of the polymer of the group represented by formula (a2-1).

In the formula (S), R ^S1 represents an alkyl group having 1 to 4 carbon atoms. m represents an integer of 1 to 20.
Specific examples of the general formula (a2-1) include a group represented by the following general formula (a2-2). In the general formula (a2-2), Rs ¹ and Rs ² in the general formula (a2-1) are methyl groups, Rs ³ is an alkyl group or an aryl group, and W is represented by the following formula (S-2). It is an aspect showing the bivalent group containing group to be made. Wherein _{(S-2), n a2} represents an integer of 2 to 100.

In General Formula (a2-2), R ²¹ represents an alkyl group or an aryl group, W ²¹ represents a divalent linking group, and X ²¹ represents —O—, —S—, or —N ( R ²⁴ ) —. Here, R ²⁴ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. N _a2 represents an integer of 2 to 100, and * represents a position where the main chain terminal of the group of the group represented by the general formula (a2-2) is connected.

The alkyl group for R ²¹ preferably has 1 to 12 carbon atoms, and may have a linear structure or a branched structure. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group. Moreover, it is more preferable that it is a C1-C6 alkyl group, and it is further more preferable that it is a C1-C4 linear alkyl group.

The aryl group for R ²¹ preferably has 6 to 20 carbon atoms, and more preferably 6 to 14 carbon atoms. Specific examples of the aryl group for R ²¹ include a phenyl group, a biphenyl group, and a naphthyl group, and a phenyl group is more preferable.

The divalent linking group represented by W ²¹ is preferably an alkylene group having 1 to 20 carbon atoms or an arylene group. The alkylene group may have a linear structure or a branched structure. Moreover, even if it has a substituent, it may be unsubstituted. Examples of the substituent that may have include a halogen atom.

When W ²¹ is an alkylene group having 1 to 20 carbon atoms, it is preferably unsubstituted, more preferably an unsubstituted alkylene group having 1 to 10 carbon atoms, and still more preferably 1 to 4 carbon atoms. An unsubstituted alkylene group. Specific examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, an octylene group, and a decylene group.

When W ²¹ is an arylene group, an arylene group having 6 to 20 carbon atoms is preferable, and an arylene group having 6 to 12 carbon atoms is more preferable. Specifically, a phenylene group, a biphenylene group, a naphthylene group, and the like can be exemplified. Of these, a phenylene group is particularly preferable.

In addition, in the divalent linking group represented by W ²¹ , an imino bond (—NH—), an amide bond (—CONH—), an ester bond (—COO— or —OCO—), an ether bond (—O— -), sulfonamide bond (-NHSO ₂ - or _-SO 2 NH-), a urethane bond (-NHCOO- or -OCONH-), ureylene bond (-NHCONH-), carbonate bond (-OCOO-), or heterocycle (Specifically, a group in which two hydrogen atoms have been removed from a heterocyclic ring such as triazine, isocyanuric acid, and piperazine) may be present as a bonding group.

Among these, W ²¹ is more preferably an unsubstituted alkylene group having 1 to 4 carbon atoms, or an unsubstituted alkylene group having 1 to 7 carbon atoms including an ether bond (—O—) as a bonding group. preferable.

X ²¹ is —O—, —S—, or —N (R ²⁴ ) —. Here, R ²⁴ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and the alkyl group may be a straight chain structure or a branched structure. Examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a tert-butyl group. Among these, R ²⁴ is preferably a hydrogen atom or a methyl group.
X ²¹ is most preferably —O— among these.

Specific introduction of the group represented by the general formula (a2-1) or the group represented by the general formula (a2-2), which is a more specific aspect thereof, into the main chain terminal of the polymer (A). Such a method will be described later. For example, when a group represented by the general formula (a2-2) is to be introduced into the polymer, the group represented by the general formula (a2-2) is used during the synthesis of the polymer (A). A commercially available compound having the structure described above may be applied.
As the compound containing the structure represented by the general formula (a2-2), an alcohol compound, an amine compound, a thiol compound, or the like can be used, but an alcohol compound is preferable, and specifically, the following general formula A compound represented by formula (a2-3) is more preferable.

In formula ^{(a2-3), W 21, R} 21, and _{n a2} preferred ranges are also included, which is the same meaning as ^{W 21, R 21,} and _{n a2} in formula (a2-2).

Examples of the compound represented by the general formula (a2-3) include the following compounds (in the exemplified compound, n _a2 is an integer of ₂ to 100). However, the present invention is not limited to these.

By using the alcohol compound having the siloxane structure, the siloxane structure of the exemplary compound is introduced at the end of the polymer (A).
The alcohol compound represented by the general formula (a2-3) is available as a commercial product, for example, X-22-170BX, X-22-170DX, X-22 manufactured by Shin-Etsu Chemical Co., Ltd. -173DX, FM-0411, FM-0421, FM-0425, etc. manufactured by Chisso Corporation can be exemplified. By using the exemplified commercially available alcohol compound, a siloxane structure derived from the alcohol compound is bonded to the terminal of the (A) polymer.

As another example of the method for synthesizing the polymer (A) having a group containing a siloxane structure at at least one terminal, a method of introducing a compound having a siloxane structure as shown below other than the alcohol compound into the polymer terminal. Examples of commercially available products used in this method include Gelst MCR-A11 (one-end amino group-modified polydimethylsiloxane), MCR-C12, MCR-C18, MCR-C22, and (one-end carbinol-modified polydimethylsiloxane). Siloxane), MCR-C13 (both are trade names), and the like. Further, as a compound having a siloxane structure that can be used in this method by partial modification, reaction of UTT-1012 (trade name Gelest, acryloxypropyl- (dimethylsiloxane) copolymer) and mercaptoethanol Examples thereof include a reaction product of UTT-1012 and mercaptopropanol, a reaction product of MCR-E11 (trade name, one-end epoxy-modified polydimethylsiloxane, manufactured by Gelest) and propionic acid, and the like.
Although the example of the terminal structure which has a siloxane structure which can be introduce | transduced into the said (A) polymer is given below, this invention is not limited to this. In the following structure, * indicates a connecting portion with the end of the polymer main chain. n represents an integer of 5 to 100.

((A3) long chain alkyl group)
The (a3) long chain alkyl group contained in the surface segregation polymer in the present invention is preferably an alkyl group having 10 or more carbon atoms. More preferably, it is an alkyl group having 10 to 40 carbon atoms, more preferably an alkyl group having 10 to 30 carbon atoms, and most preferably an alkyl group having 10 to 20 carbon atoms. The long-chain alkyl group may contain a branched structure or a cyclic structure, but the number of carbon atoms in the straight-chain structure is preferably in the above-mentioned range, and all of the straight-chain structures are more preferable. That is, it is more preferably a long-chain alkyl group having a linear structure and having the above-mentioned preferable carbon number.

  Specifically, it is preferable to have a group represented by the following general formula (a3-1) at the main chain terminal of the polymer (A).

In General Formula (a3-1), W ³¹ represents a single bond or a divalent linking group, and X ³¹ represents —O—, —S—, or —N (R ³⁴ ) —. Here, R ³⁴ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. N _a3 represents an integer of 10 or more, and * represents a position to be connected to the end of the main chain of the polymer.

In general formula (a3-1), _na3 is preferably an integer of 10 to 40, more preferably an integer of 10 to 30, and most preferably an integer of 10 to 20.

X ³¹ is —O—, —S—, or —N (R ³⁴ ) —. Here, R ³⁴ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and the alkyl group may have a linear structure or a branched structure. Specifically, Examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a tert-butyl group. Among these, R ³⁴ is preferably a hydrogen atom or a methyl group.
X ³¹ is most preferably —O— among these.

Further, examples of the divalent linking group represented by ^{W 31, ** - R 311 COO} -, ** - R 311 OCO -, ** - R 311 CON (R 322) -, ** - R 311 N (R ³²² ) COO—, ** — R ³¹¹ O—, ** — R ³¹¹ NH—, ** — R ³¹¹ S—, and the like. Here, ** represents the bonding position with X ³¹ in formula (a3-1), and R ³¹¹ represents an alkylene group. R ³²² represents a hydrogen atom or an alkyl group. When R ³¹¹ represents an alkylene group, and when R ³²² represents an alkyl group, the alkylene group and the alkyl group preferably have 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, It is especially preferable that it is C1-C4. In addition, the alkyl group or alkylene group may have a linear structure or a branched structure, but is more preferably a linear structure alkyl group.

Among these, W ³¹ is preferably ** — R ³¹¹ COO—, and a combination in which R ³¹¹ is an alkyl group having 1 to 4 carbon atoms is particularly preferable.

A specific method for introducing the group represented by the general formula (a3-1) into the end of the main chain of the polymer (A) will be described later. At the time of synthesizing the polymer (A), the general formula (a3-1) A commercially available compound having a structure represented by
Specifically, the compound including the structure represented by the general formula (a3-1) is more preferably a compound represented by the following general formula (a3-2).

In formula ^{(a3-2), Y 31} represents a hydroxyl group, an amino group, or thiol ^{group, W 31} and _{n a3} preferred ranges are also included, the formula ^{W 31} in (a3-1) and _{n a3} Are synonymous with each other. However, the divalent linking group represented by W ³¹ is **-R ³¹¹ COO-, **-R ³¹¹ OCO-, **-R ³¹¹ CON (R ³²² )-, **-R ³¹¹ N (R ³²² ) COO-, **-R ³¹¹ O-, **-R ³¹¹ NH-, or **-R ³¹¹ S-, ** is a bond to Y ³¹ in the general formula (a3-2) Represents the position.

Y ³¹ is preferably a hydroxyl group.

  As a compound represented by general formula (a3-2), the following can be illustrated, for example. However, the present invention is not limited to these.

  Among the (a1) fluorine-substituted hydrocarbon group, (a2) group containing a siloxane structure, and (a3) a long-chain alkyl group, the polymer (A) according to the present invention has at least one terminal of the main chain structure. The (a1) fluorine-substituted hydrocarbon group or (a2) a group containing a siloxane structure is preferred, and (a2) a group containing a siloxane structure is particularly preferred.

In the present invention, (a1) the fluorine-substituted hydrocarbon group, and (a2) content of the surface segregation polymer of at least one group selected from the group or Ranaru group including a siloxane structure (i.e., (A) in the polymer Content of the partial structure represented by the general formula I or the general formula (a2-1 ), and (A) a raw material compound that gives a terminal structure with respect to the number average molecular weight of the polymer (in the general formula I a compound containing a structure represented, or the general formula can be approximated by the ratio of the number average molecular weight of the compound of (a2-2))) is preferably from 0.1% to 30% by weight, respectively, more preferably 0 .3% by mass to 25% by mass, and more preferably 0.5% by mass to 20% by mass.
By setting it as the said range, the effect of this invention can be improved more.

  In addition, at least one group selected from (a1) a fluorine-substituted hydrocarbon group, (a2) a group containing a siloxane structure, or (a3) a long-chain alkyl group is at least a main chain structure in the (A) polymer. It may be contained in either one, but it may be contained in both ends, and it is particularly preferable that it is contained in both ends of the main chain structure. In addition, when it has several said specific group at the terminal of main chain structure, such as both ends of a main chain structure, they may mutually be same or different.

(Polymerizable group)
The surface segregation polymer in the present invention has a polymerizable group in the side chain. The polymerizable group is particularly preferably a radical polymerizable group.

Examples of the radical polymerizable group include a polymerizable group having an ethylenically unsaturated bond capable of radical polymerization.
Examples of polymerizable groups having an ethylenically unsaturated bond capable of radical polymerization include acrylic acid ester groups, methacrylic acid ester groups, itaconic acid ester groups, crotonic acid ester groups, isocrotonic acid ester groups, and maleic acid ester groups. Examples thereof include radically polymerizable groups such as unsaturated carboxylic acid ester groups and styrene groups. Among these, a methacrylic acid ester group and an acrylic acid ester group (that is, a (meth) acrylic acid ester group) are preferable.

  The content of the radical polymerizable group is preferably 0.3 mmol / g or more in the surface segregation polymer, more preferably 1.2 mmol / g to 6 mmol / g, still more preferably 1.8 mmol / g. ~ 4 mmol / g.

  As a method for introducing a radically polymerizable group into a surface segregation polymer, a monomer in which a reaction is blocked with a double bond of a radically polymerizable group using a protective group, this monomer is copolymerized, and the protective group is removed. A method of forming a radically polymerizable group (double bond), a method of introducing a low molecular compound having a radically polymerizable group into a surface segregation polymer by a polymer reaction, and a radically polymerizable group in a side chain as a diisocyanate compound or a diol compound The method of superposing | polymerizing using what has is mentioned.

(Main chain structure)
The surface segregation polymer contained in the ink composition of the present invention is a so-called polyurethane resin or polyurea resin containing a urethane bond (—NHCOO— or —OCONH—) or a urea bond (—NHCONH—) in the main chain structure. It is.

  The main chain structure of the surface segregation polymer can form a polyurethane structure by reacting a diisocyanate and a polyol component such as a diol, and can form a polyurea structure by reacting the diisocyanate and a diamine component. it can.

Examples of the diisocyanate that can form a polyurethane structure or a polyurea structure include tolylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, norbornene diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, diphenylmethane-4,4 ′. -Diisocyanate, dimer acid diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, hydrogenated m-xylylene diisocyanate, hydrogenated p-xylylene diisocyanate, tetramethyl-m-xylylene diisocyanate, hydrogenated diphenylmethane Examples include -4,4'-diisocyanate and 1,2-bisisocyanatoethoxyethane.
Among these, from the viewpoints of reactivity and ink curability, a structure containing tolylene diisocyanate, diphenylmethane-4,4′-diisocyanate, dimer acid diisocyanate, m-xylylene diisocyanate, and p-xylylene diisocyanate is more preferable.

Examples of polyol components that can form a polyurethane structure include ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,4-butanediol, 2,3-butanediol, 1,3-butanediol, neopentyl glycol, and methylpentane. Diol, 1,6-hexanediol, trimethylhexamethylenediol, 2-methyloctanediol, 1,9-nonanediol, 1,4-cyclohexanedimethanol, tricyclodecane dimethanol, polycaprolactone diol, polycarbonate diol, glycerin, Examples include trimethylolpropane, trimethyloloctane, pentaerythritol, polytetramethylene glycol and the like.
Among these, it is preferable to use a polyol having a molecular weight of 4000 or less.

  Examples of the diamine that can form a polyurea structure include ethylenediamine, N-alkylethylenediamine, propylenediamine, 2,2-dimethyl-1,3-propanediamine, N-alkylpropylenediamine, butylenediamine, N-alkylbutylenediamine, Pentanediamine, hexamethylenediamine, N-alkylhexamethylenediamine, heptanediamine, octanediamine, nonanediamine, decanediamine, dodecanediamine, hexadecanediamine, tolylenediamine, xylylenediamine, diaminodiphenylmethane, diaminodicyclohexylmethane, phenylenediamine, cyclohexyl Sylenediamine, bis (aminomethyl) cyclohexane, diaminodiphenylsulfone, isophoronediamine, 2-butyl 2-ethyl-1,5-pentamethylenediamine, 2,2,4- or 2,4,4-trimethyl-1,6-hexamethylenediamine, 2-aminopropylcyclohexylamine, 3 (4) -aminomethyl- Examples thereof include 1-methylcyclohexylamine, 1,4-diamino-4-methylpentane, amine-terminated polyoxyalkylene polyol (known as Jeffamines), and amine-terminated polytetramethylene glycol.

  When synthesizing a polymer containing a urethane bond (-NHCOO-, or -OCONH-) or a urea bond (-NHCONH-) in the main chain structure in the present invention, a diol having a polymerizable group or a polymerizable group is added. By using the diisocyanate having as a raw material, a polymerizable urethane compound can be obtained by a one-step reaction.

(Method of introducing (a1) a fluorine-substituted hydrocarbon group, (a2) a group containing a siloxane structure, or (a3) a long-chain alkyl group into at least one terminal of the main chain structure)
The polymer (A) contained in the ink composition of the present invention is any one of the (a1) fluorine-substituted hydrocarbon group, the (a2) group containing a siloxane structure, or the (a3) long-chain alkyl group. It is included at at least one end of the aforementioned main chain structure.
The details of the introduction method will be described below. In the present invention, the method for introducing the (a1) fluorine-substituted hydrocarbon group, the (a2) group containing a siloxane structure, or the (a3) long-chain alkyl group into the main chain is not limited thereto. Absent.

The (a1) fluorine-substituted hydrocarbon group, the group (a2) containing a siloxane structure, or the (a3) long-chain alkyl group is obtained by using a compound having these structures as a polymerization terminator (A) It can be introduced at the end of the main chain of the polymer. That is, at the time of synthesizing the polymer (A), a compound having a desired structure to be introduced may be appropriately selected and used as a polymerization terminator.
Examples of the compound having the (a1) fluorine-substituted hydrocarbon group, the group (a2) containing a siloxane structure, or the (a3) long-chain alkyl group include alcohol compounds (preferably monovalent (that is, one hydroxyl group). And alcohol compounds), thiol compounds, or amine compounds.

  That is, it has (a1) a fluorine-substituted hydrocarbon group, (a2) a group containing a siloxane structure, or (a3) a long-chain alkyl group, and has an alcoholic hydroxyl group, thiol group, or amino group at the terminal. Compounds can be used. Among these, the compound having the (a1) fluorine-substituted hydrocarbon group, the (a2) group containing a siloxane structure, or the (a3) long-chain alkyl group and having an alcoholic hydroxyl group at the terminal is particularly preferable.

Specifically, first, when obtaining the polyurethane structure by reacting the aforementioned diisocyanate and polyol, the total number of moles of isocyanate groups contained in the synthesis system is slightly excessive with respect to the total number of moles of hydroxyl groups contained. To obtain a polymer having an isocyanate group at the terminal.
Subsequently, a compound (preferably, having (a1) a fluorine-substituted hydrocarbon group, (a2) a group containing a siloxane structure, or (a3) a long-chain alkyl group) on the isocyanate group formed at the polymer terminal. By reacting an alcohol compound, a thiol compound, or an amine compound), the desired structure of (a1), (a2), or (a3) can be introduced into the main chain terminal of the polymer. It should be noted that how small the excess of isocyanate groups can be appropriately determined according to the molecular weight of the polymer (A) to be formed. Depending on the molecular weight of the polymer and the number of terminal groups to be introduced, a desired structure can be obtained even when the compound containing the structure (a1), (a2), or (a3) is reacted with diisocyanate and polyol at once. .

  In addition, when obtaining the polyurea structure by reacting the diisocyanate and the diamine component, the total number of isocyanate groups contained in the synthesis system is set to a small excess with respect to the total number of moles of amino groups contained. What is necessary is just to make it react similarly to the case of the above-mentioned polyurethane structure.

  In addition, an epoxy compound can also be used as the compound having (a1) a fluorine-substituted hydrocarbon group, (a2) a group containing a siloxane structure, or (a3) a long-chain alkyl group. In this case, when the diisocyanate and polyol (or diamine component) are reacted, the total number of hydroxyl groups (or amino groups) contained in the synthesis system is excessive with respect to the total number of moles of isocyanate groups contained. As described above, a polymer having a hydroxyl group (or amino group) at the terminal may be synthesized, and the epoxy compound may be reacted with the hydroxyl group (or amino group) formed at the polymer terminal. The same polymer can also be obtained by adding a small amount of a compound having one hydroxyl group and one carboxylic acid group in the molecule to synthesize a prepolymer having a carboxylic acid group at the terminal and then reacting the above epoxy compound. Can be obtained.

  The surface segregation polymer may be synthesized in a solvent, but is preferably synthesized in a polymerizable monomer using a polymerizable monomer as a reaction solvent. That is, (B) purification is performed after synthesis by synthesizing the polymer (A) in the polymerizable monomer [(B) component] contained in the ink composition as a polymerizable compound other than the polymer (A). In this case, the reaction product (A) polymer and the solvent (B) polymerizable monomer can be used as they are for the preparation of the ink composition. Specifically, for example, a method of synthesizing using N-vinylcaprolactam, tripropylene glycol diacrylate, tripropylene glycol diacrylate, tetrahydrofurfuryl acrylate, 2-phenoxyethyl acrylate, dimethylacrylamide or the like as a reaction solvent is preferable. It is done. Of these, N-vinylcaprolactam and dimethylacrylamide are more preferably used as the reaction solvent.

  The weight average molecular weight of the surface segregation polymer is preferably from 5,000 to 200,000, more preferably from 8,000 to 150,000, still more preferably from 10,000 to 100,000.

  The content of the polymer (A) relative to the total content of the polymer (A) and the polymerizable compound (B) is preferably 0.3% by mass to 15% by mass, It is more preferably 7.5% by mass, and further preferably 0.3% by mass to 5% by mass.

Further, the content of the polymer (A) contained in the ink composition of the present invention is preferably 0.2% by mass to 9% by mass, and preferably 0.2% by mass to 5% by mass in the total solid content of the ink composition. Is more preferable, and 0.2 mass%-3 mass% is still more preferable.
Here, the “total solid content” means the total amount of nonvolatile components contained in the ink composition.

Listed below are the preferred examples of Table Menhen析polymer [exemplary compound (SP-1) ~ (SP -18) ]. The (A) polymers contained in the ink composition of the present invention are the following exemplary compounds (SP-1) to (SP-3) and (SP-5) to (SP-18). The present invention is not limited to these specific examples. (Note that R in each formula represents a commercially available alcohol compound used for synthesis: FM-0411 or n-butyl group derived from FM-0411 (manufactured by Chisso)) and an exemplary compound (SP-1 ), N _a2 in (SP-1), (SP-2), (SP-5) to (SP-8) are each a mixture of 10 to 12.

Moreover, the surface segregation polymer [Exemplary compound (SP-19)-(SP-41)] which has the structural unit shown below and a terminal structure is also used suitably as a ( A) polymer. The polymer (A) contained in the ink composition of the present invention includes the following exemplary compounds (SP-19) to (SP-34) and (SP-39) to (SP-41).

<(B) Polymerizable compound other than (A) polymer (surface segregation polymer)>
In addition to the polymer (A) (surface segregation polymer), the ink composition of the present invention contains known polymerizable compounds generally used for curable compositions other than these. Specifically, it contains a polymerizable compound that does not have any structure of the above-mentioned (a1) fluorine-substituted hydrocarbon group, (a2) a group containing a siloxane structure, and (a3) a long-chain alkyl group.
Hereinafter, such a polymerizable compound is also referred to as (B) another polymerizable compound as appropriate. (B) The other polymerizable compound is preferably a radical polymerizable compound.

(B-1) Radical polymerizable compound (B) The radical polymerizable compound used as another polymerizable compound is a compound having an ethylenically unsaturated bond capable of radical polymerization, A compound having at least one radically polymerizable ethylenically unsaturated bond, which does not include the aforementioned (a1) fluorine-substituted hydrocarbon group, (a2) a group containing a siloxane structure, and (a3) a long-chain alkyl group Any organic compound may be used, including those having chemical forms such as monomers, oligomers, and polymers. Only one kind of radically polymerizable compound may be used, or two or more kinds thereof may be used in combination at an arbitrary ratio in order to improve desired properties.

  Examples of the polymerizable compound having an ethylenically unsaturated bond capable of radical polymerization include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, and salts thereof, Examples thereof include radically polymerizable compounds such as anhydrides having a saturated group, acrylonitrile, styrene, various unsaturated polyesters, unsaturated polyethers, unsaturated polyamides, and unsaturated urethanes.

  Specifically, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, butoxyethyl acrylate, carbitol acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, benzyl acrylate, bis (4-acryloxypolyethoxyphenyl) propane, neopentyl glycol Diacrylate, 1,6-hexanediol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, pentaerythritol triacrylate, pentaerythritol Tetraacrylate, dipentaery Acrylic acid derivatives such as lithol tetraacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, oligoester acrylate, N-methylol acrylamide, diacetone acrylamide, epoxy acrylate, methyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate , Lauryl methacrylate, allyl methacrylate, glycidyl methacrylate, benzyl methacrylate, dimethylaminomethyl methacrylate, 1,6-hexanediol dimethacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, trimethylol Methacryl derivatives such as tan trimethacrylate, trimethylolpropane trimethacrylate, 2,2-bis (4-methacryloxypolyethoxyphenyl) propane, and other derivatives of allyl compounds such as allyl glycidyl ether, diallyl phthalate, triallyl trimellitate More specifically, Shinzo Yamashita, “Cross-linking agent handbook”, (1981 Taiseisha); Kato Kiyomi, “UV / EB curing handbook (raw material)” (1985, Polymer publication) ); Rad-Tech Study Group, “Application and Market of UV / EB Curing Technology”, p. 79, (1989, CMC); Eiichiro Takiyama, “Polyester Resin Handbook”, (1988, Nikkan Kogyo Shimbun) Commercially available products described in the above, or radically polymerizable or crosslinkable monomers known in the industry, Ligomers and polymers can be used.

  Examples of the radical polymerizable compound include those disclosed in JP-A-7-159983, JP-B-7-31399, JP-A-8-224982, JP-A-10-863, JP-A-9-134011, and the like. Photo-curable polymerizable compound materials used for the described photopolymerizable compositions are known, and these can also be applied to the ink composition of the present invention.

Furthermore, it is also preferable to use a vinyl ether compound as the radical polymerizable compound. Suitable vinyl ether compounds include, for example, ethylene glycol divinyl ether, ethylene glycol monovinyl ether, diethylene glycol divinyl ether, triethylene glycol monovinyl ether, triethylene glycol divinyl ether, propylene glycol divinyl ether, dipropylene glycol divinyl ether, butanediol. Di- or trivinyl ether compounds such as divinyl ether, hexanediol divinyl ether, cyclohexanedimethanol divinyl ether, hydroxyethyl monovinyl ether, hydroxynonyl monovinyl ether, trimethylolpropane trivinyl ether, ethyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, octade Such as ruvinyl ether, cyclohexyl vinyl ether, hydroxybutyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexanedimethanol monovinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, isopropenyl ether-O-propylene carbonate, dodecyl vinyl ether, diethylene glycol monovinyl ether, and octadecyl vinyl ether And monovinyl ether compounds.
Of these vinyl ether compounds, divinyl ether compounds and trivinyl ether compounds are preferable from the viewpoints of curability, adhesion, and surface hardness, and divinyl ether compounds are particularly preferable. A vinyl ether compound may be used individually by 1 type, and may be used in combination of 2 or more type as appropriate.

In the total solid content of the ink composition of the present invention, the content of the (B-1) radical polymerizable compound is preferably 50% by mass to 90% by mass, and more preferably 55% by mass to 90% by mass. More preferably, it is 60 mass%-85 mass%.
In order to further improve the flexibility of the coating film, the content of the monofunctional monomer in the radical polymerizable compound is preferably 60% by mass to 100% by mass, more preferably 70% by mass to 100% by mass, and 80% by mass. More preferably, it is -100 mass%.

  Preferable examples of the monofunctional monomer include phenoxyethyl acrylate, N-vinylcaprolactam, tetrahydrofurfuryl acrylate, cyclic trimethylolpropane formal acrylate, isobornyl acrylate, and the like, more preferably phenoxyethyl acrylate. , N-vinylcaprolactam, and isobornyl acrylate.

(B-2) A compound having a ring-opening polymerization reaction site and a radical polymerization reaction site (B) As another polymerizable compound, a compound having a ring-opening polymerization reaction site and a radical polymerization reaction site can also be used. . As such a compound, Bremermer G (manufactured by Nippon Oil & Fats Co., Ltd.), OXE-10 (manufactured by Osaka Organic Chemical Industry Co., Ltd.), OXE-30 (manufactured by Osaka Organic Chemical Industry Co., Ltd.) are commercially available. ), Cyclomer A400 (manufactured by Daicel Chemical Industries, Ltd.), 4HBAGE (manufactured by Nippon Kasei Chemical Co., Ltd.), GBLA (manufactured by Osaka Organic Chemical Industries, Ltd.), M-GMA (manufactured by Daicel Chemical Industries, Ltd.) ), Cyclomer M100 (manufactured by Daicel Cytec Co., Ltd.) and the like.
Examples of the ring-opening polymerizable compound having a radical polymerizable group include the following compounds, but the present invention is not limited thereto.

<(C) Polymerization initiator>
The ink composition of the present invention contains (C) a polymerization initiator. (C) A polymerization initiator is a compound which produces | generates a polymerization start seed | species by irradiation of an active energy ray, and can select and use a well-known polymerization initiator suitably.
Here, the active energy ray is not particularly limited as long as it can impart energy capable of generating a starting species in the ink composition by irradiation, and α ray, γ ray, X ray, ultraviolet ray, Infrared rays, visible rays, electron beams and the like are included. Among these, from the viewpoint of curing sensitivity and device availability, ultraviolet rays or electron beams are preferable, and ultraviolet rays are more preferable. Therefore, the ink composition of the present invention is preferably one that can be cured by irradiating ultraviolet rays as active energy rays. As a light source for generating ultraviolet rays, a light source having a light emission wavelength of 300 nm to 400 nm is preferable. Low pressure mercury lamps, high pressure mercury lamps, short arc discharge lamps, ultraviolet light emitting diodes, semiconductor lasers, fluorescent lamps and the like, which are known ultraviolet lamps, are used. A xenon lamp belonging to a high-pressure mercury lamp, a metal halide lamp, or a short arc discharge lamp belonging to a high-pressure discharge lamp is preferably used depending on the light amount and wavelength suitable for the initiator. Moreover, an ultraviolet light emitting diode is also preferably used from the viewpoint of energy saving.

(C-1) Radical polymerization initiator The (C) polymerization initiator is preferably (C-1) a radical polymerization initiator, such as (a) aromatic ketones and (b) acylphosphine oxide compounds. (C) aromatic onium salt compound, (d) organic peroxide, (e) thio compound, (f) hexaarylbiimidazole compound, (g) ketoxime ester compound, (h) borate compound, (i) Examples thereof include azinium compounds, (j) metallocene compounds, (k) active ester compounds, (l) compounds having a carbon halogen bond, and (m) alkylamine compounds.

  These radical polymerization initiators may be used alone or in combination of two or more of the compounds (a) to (m).

  Among these, (a) aromatic ketones, (b) acylphosphine compounds, and (e) thio compounds are preferred. Preferred examples of these are "RADIATION CURING IN POLYMER SCIENCE AND TECHNOLOGY", J. P. FOUASSIER, J. F. RABEK (1993), pp. Examples include compounds having a benzophenone skeleton or a thioxanthone skeleton described in 77-117. More preferable examples include α-thiobenzophenone compounds described in JP-B-47-6416, benzoin ether compounds described in JP-B-47-3981, α-substituted benzoin compounds described in JP-B-47-22326, Benzoin derivatives described in JP-B-47-23664, aroylphosphonic acid esters described in JP-A-57-30704, dialkoxybenzophenones described in JP-B-60-26483, JP-B-60-26403, JP-A Benzoin ethers described in JP-A-62-81345, JP-B-1-34242, US Pat. No. 4,318,791, α-aminobenzophenones described in European Patent 0284561A1, JP-A-2-21152 P-Di (dimethylaminobenzoyl) benze Thio-substituted aromatic ketones described in JP-A-61-194062, acylphosphine sulfides described in JP-B-2-9597, acylphosphines described in JP-B-2-9596, and JP-B-63-61950 Thioxanthones, and coumarins described in JP-B-59-42864.

  Furthermore, in the present invention, it is particularly preferable to use an acylphosphine oxide compound as a polymerization initiator, and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (Irgacure 819: manufactured by BASF Japan), bis (2 , 6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (Darocur TPO: manufactured by BASF Japan, Lucirin TPO: manufactured by BASF), 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one (Irgacure 907: manufactured by BASF Japan), 2-benzyl-2-dimethylamino-1- (4-morpholinopheny ) - butanone -1 (Irgacure 369: manufactured by BASF Japan Ltd.) and the like are preferable.

  The content of the (C) polymerization initiator in the present invention is preferably in the range of 1% by mass to 50% by mass, and preferably in the range of 2% by mass to 40% by mass with respect to the total solid content of the ink composition of the present invention. More preferably, the range of 3% by mass to 20% by mass is even more preferable.

~ Other ingredients ~
In the ink composition of the present invention, in addition to the components (A) to (C), other components can be used in combination for the purpose of improving physical properties, as long as the effects of the present invention are not impaired.
Hereinafter, these optional components will be described below.

<Colorant>
The ink composition of the present invention can form a visible image by adding a colorant. The colorant that can be used here is not particularly limited, and various known color materials (such as pigments, dyes, and resin particles dyed with dyes) may be appropriately selected and used depending on the application. Can do. For example, when forming an image excellent in weather resistance, a pigment is preferable. As the dye, both water-soluble dyes and oil-soluble dyes can be used, but oil-soluble dyes are preferred.

(Pigment)
The pigment preferably used in the present invention will be described.
The pigment is not particularly limited, and all commercially available organic and inorganic pigments or pigments dispersed in an insoluble resin or the like as a dispersion medium, or the resin is grafted onto the pigment surface Can be used.
Examples of these pigments include, for example, “Pigment Dictionary” (2000), edited by Seijiro Ito. Herbst, K.M. Hunger “Industrial Organic Pigments”, JP 2002-12607 A, JP 2002-188025 A, JP 2003-26978 A, and JP 2003-342503 A3.

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

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

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

As a pigment exhibiting green, C.I. I. Pigment green 7 (phthalocyanine green), C.I. I. Phthalocyanine pigments such as C.I. Pigment Green 36 (phthalocyanine green); I. And azo metal complex pigments such as CI Pigment Green 8 (Nitroso Green).
As a pigment exhibiting an orange color, C.I. I. An isoindoline pigment such as C.I. Pigment Orange 66 (isoindoline orange); I. And anthraquinone pigments such as CI Pigment Orange 51 (dichloropyrantron orange).

Examples of the black pigment include carbon black, titanium black, and aniline black.
Specific examples of the white pigment include basic lead carbonate (2PbCO ₃ Pb (OH) ₂ , so-called silver white), zinc oxide (ZnO, so-called zinc white), titanium oxide (TiO ₂ , so-called titanium white), Strontium titanate (SrTiO ₃ , so-called titanium strontium white) or the like can be used.

  Here, titanium oxide has a smaller specific gravity than other white pigments, a large refractive index, and is chemically and physically stable, and thus has a high hiding power and coloring power as a pigment. Excellent durability against other environments. Therefore, it is preferable to use titanium oxide as the white pigment. Of course, other white pigments (may be other than the listed white pigments) may be used as necessary.

For dispersing the pigment, for example, a dispersion device such as a ball mill, a sand mill, an attritor, a roll mill, a jet mill, a homogenizer, a paint shaker, a kneader, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a pearl mill, or a wet jet mill is used. be able to.
It is also possible to add a dispersant when dispersing the pigment. Examples of the dispersant include a hydroxyl group-containing carboxylic acid ester, a salt of a long-chain polyaminoamide and a high molecular weight acid ester, a salt of a high molecular weight polycarboxylic acid, a high molecular weight unsaturated acid ester, a high molecular weight copolymer, a modified polyacrylate, an aliphatic Examples thereof include polyvalent carboxylic acids, naphthalene sulfonic acid formalin condensates, polyoxyethylene alkyl phosphate esters, and pigment derivatives. It is also preferable to use a commercially available polymer dispersant such as Solsperse series manufactured by Nippon Lubrizol.
Moreover, it is also possible to use a synergist according to various pigments as a dispersion aid. These dispersants and dispersion aids are preferably added in an amount of 1 to 50 parts by weight per 100 parts by weight of the pigment.
In the ink composition, as a dispersion medium for various components such as pigments, a solvent may be added, and the above (B) other polymerizable compound which is a low molecular weight component without solvent is used as a dispersion medium. However, it is preferably solvent-free.

The average particle diameter of the pigment is preferably in the range of 0.02 μm to 0.4 μm, more preferably in the range of 0.02 μm to 0.1 μm, and more preferably 0.02 μm to 0.07 μm. It is a range.
The selection of pigment, dispersant, dispersion medium, dispersion conditions, and filtration conditions are set so that the average particle diameter of the pigment particles is within the above-mentioned preferable range. By controlling the particle size, clogging of the head nozzle can be suppressed, and ink storage stability, ink transparency, and curing sensitivity can be maintained.

(dye)
The dye used in the present invention is preferably oil-soluble. Specifically, it means that the solubility in water at 25 ° C. (the mass of the dye dissolved in 100 g of water) is 1 g or less, preferably 0.5 g or less, more preferably 0.1 g or less. Therefore, a so-called water-insoluble oil-soluble dye is preferably used.

The dye used in the present invention preferably has an oil-solubilizing group introduced into the above-described dye mother core in order to dissolve the necessary amount in the ink composition.
As the oil-solubilizing group, long chain, branched alkyl group, long chain, branched alkoxy group, long chain, branched alkylthio group, long chain, branched alkylsulfonyl group, long chain, branched acyloxy group, long chain, branched alkoxycarbonyl group, Long chain, branched acyl group, long chain, branched acylamino group long chain, branched alkylsulfonylamino group, long chain, branched alkylaminosulfonyl group and these long chains, aryl groups containing branched substituents, aryloxy groups, aryloxycarbonyl Group, arylcarbonyloxy group, arylaminocarbonyl group, arylaminosulfonyl group, arylsulfonylamino group and the like.
In addition, for water-soluble dyes having carboxylic acid and sulfonic acid, long chain, branched alcohol, amine, phenol, aniline derivatives are used as oil-solubilizing alkoxycarbonyl groups, aryloxycarbonyl groups, alkylaminosulfonyl groups, A dye may be obtained by conversion to an arylaminosulfonyl group.

The oil-soluble dye preferably has a melting point of 200 ° C. or lower, more preferably has a melting point of 150 ° C. or lower, and still more preferably has a melting point of 100 ° C. or lower. By using an oil-soluble dye having a low melting point, the precipitation of dye crystals in the ink composition is suppressed, and the storage stability of the ink composition is improved.
Further, it is desirable that the oxidation potential is noble (high) in order to improve fading, particularly resistance to oxidizing substances such as ozone and curing characteristics. For this reason, as the oil-soluble dye used in the present invention, those having an oxidation potential of 1.0 V (vs SCE) or more are preferably used. The oxidation potential is preferably higher, the oxidation potential is more preferably 1.1 V (vs SCE) or more, and particularly preferably 1.15 V (vs SCE) or more.

As the yellow dye, a compound having a structure represented by the general formula (Y-I) described in JP-A No. 2004-250483 is preferable.
Particularly preferred dyes are dyes represented by the general formulas (Y-II) to (Y-IV) described in paragraph [0034] of JP-A No. 2004-250483. And the compounds described in paragraph numbers [0060] to [0071] of JP-A-250483. The oil-soluble dye of the general formula (Y-I) described in the publication may be used not only for yellow but also for inks of any color such as black ink and red ink.

The magenta dye is preferably a compound having a structure represented by the general formulas (3) and (4) described in JP-A No. 2002-114930. Specific examples include paragraphs of JP-A No. 2002-114930. Examples include the compounds described in [0054] to [0073].
Particularly preferred dyes are azo dyes represented by the general formulas (M-1) to (M-2) described in paragraph numbers [0084] to [0122] of JP-A No. 2002-121414, and specific examples Examples thereof include compounds described in paragraph numbers [0123] to [0132] of JP-A No. 2002-121414. The oil-soluble dyes represented by the general formulas (3), (4) and (M-1) to (M-2) described in the publication are used not only for magenta but also for any color ink such as black ink and red ink. May be.

Examples of the cyan dye include dyes represented by formulas (I) to (IV) described in JP-A No. 2001-181547, and paragraphs [0063] to [0078] of JP-A No. 2002-121414. The dyes represented by the general formulas (IV-1) to (IV-4) described above are preferred, and specific examples include paragraph numbers [0052] to [0066] of JP-A No. 2001-181547. Examples thereof include the compounds described in paragraph Nos. [0079] to [0081] of Kai 2002-121414.
Particularly preferred dyes are phthalocyanine dyes represented by general formulas (CI) and (C-II) described in paragraphs [0133] to [0196] of JP-A No. 2002-121414, A phthalocyanine dye represented by formula (C-II) is preferred. Specific examples thereof include the compounds described in JP-A No. 2002-121414, paragraph numbers [0198] to [0201]. The oil-soluble dyes of the formulas (I) to (IV), (IV-1) to (IV-4), (CI) and (C-II) are not only cyan but also black ink or green ink. The ink may be used for any color ink.

The colorant is preferably added in an amount of 1% by mass to 20% by mass in terms of solid content in the ink composition, and more preferably 2% by mass to 10% by mass.
When the content of the colorant is within the above range, it is preferable because a sufficient color density is obtained and appropriate curability is maintained.

<Ultraviolet absorber>
In the present invention, from the viewpoint of improving the weather resistance of an image to be obtained and preventing discoloration, an ultraviolet absorber can be used as long as the effects of the present invention are not impaired.
Examples of the ultraviolet absorber are described in JP-A-58-185679, JP-A-61-190537, JP-A-2-782, JP-A-5-97075, JP-A-9-34057, and the like. Benzotriazole compounds, benzophenone compounds described in JP-A No. 46-2784, JP-A No. 5-194843, US Pat. No. 3,214,463, etc., JP-B Nos. 48-30492 and 56-21141 Cinnamic acid compounds described in JP-A-10-88106, JP-A-4-298503, JP-A-8-53427, JP-A-8-239368, JP-A-10-182621, JP The triazine compounds described in JP-A-8-501291, Research Disclosure No. Examples thereof include compounds described in No. 24239, compounds that emit ultraviolet light by absorbing ultraviolet rays typified by stilbene and benzoxazole compounds, so-called fluorescent brighteners, and the like.
The addition amount is appropriately selected according to the purpose, but is generally about 0.5% by mass to 15% by mass in terms of solid content.

<Sensitizer>
If necessary, a sensitizer may be added to the ink composition of the present invention for the purpose of increasing the photosensitive wavelength. Any sensitizer may be used as long as it sensitizes the polymerization initiator by an electron transfer mechanism or an energy transfer mechanism.

<Antioxidant>
In order to improve the stability of the ink composition, an antioxidant can be added as long as the effects of the present invention are not impaired. Examples of the antioxidant include European published patents, 223739, 309401, 309402, 310551, 310552, 359416, and 3435443. JP, 54-85535, 62-262417, 63-113536, 63-163351, JP-A-2-262654, JP-A-2-71262, Examples thereof include those described in Kaihei 3-121449, JP-A-5-61166, JP-A-5-119449, US Pat. No. 4,814,262, US Pat. No. 4,980,275, and the like.
The addition amount is appropriately selected according to the purpose, but is generally about 0.1% by mass to 8% by mass in terms of solid content.

<Anti-fading agent>
In the ink composition of the present invention, various organic and metal complex anti-fading agents can be used. Examples of the organic anti-fading agent include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, and heterocycles. Examples of the metal complex anti-fading agent include nickel complexes and zinc complexes. No. 17643, No. VII, I to J, ibid. 15162, ibid. No. 18716, page 650, left column, ibid. No. 36544, page 527, ibid. No. 307105, page 872, ibid. The compounds described in the patent cited in No. 15162 and the compounds included in the general formulas and compound examples of representative compounds described in JP-A-62-215272, pages 127 to 137 can be used. .
The addition amount is appropriately selected according to the purpose, but is generally about 0.1% by mass to 8% by mass in terms of solid content.

<Conductive salts>
In the ink composition of the present invention, conductive salts such as potassium thiocyanate, lithium nitrate, ammonium thiocyanate, and dimethylamine hydrochloride are used for the purpose of controlling ejection properties when the ink composition is applied to an ink jet recording method. Can be added.

<Solvent>
In order to improve the adhesion to the recording medium, an extremely small amount of an organic solvent can be added to the ink composition of the present invention.
Examples of the solvent include ketone solvents such as acetone, methyl ethyl ketone, and diethyl ketone, alcohol solvents such as methanol, ethanol, 2-propanol, 1-propanol, 1-butanol, and tert-butanol, and chlorine such as chloroform and methylene chloride. Solvents, aromatic solvents such as benzene and toluene, ester solvents such as ethyl acetate, butyl acetate and isopropyl acetate, ether solvents such as diethyl ether, tetrahydrofuran and dioxane, glycols such as ethylene glycol monomethyl ether and ethylene glycol dimethyl ether And ether solvents.
In this case, it is possible to add in a range that does not cause a problem in solvent resistance and curability, and the amount is preferably 0.1% by mass to 5% by mass, and more preferably 0.1% by mass with respect to the entire ink composition. You may be contained in the range of mass%-3 mass%.

<Water>
In addition, the ink composition of the present invention may contain a very small amount of water as long as it does not impair the effects of the present invention, but is a non-aqueous ink composition that does not substantially contain water. Is preferred. Specifically, the water content is preferably 3% by mass or less, more preferably 2% by mass or less, and most preferably 1% by mass or less based on the total amount of the ink composition.

<Polymer compound>
Various polymer compounds can be added to the ink composition of the present invention in order to adjust film physical properties. High molecular compounds include acrylic polymers, polyvinyl butyral resins, polyurethane resins, polyamide resins, polyester resins, epoxy resins, phenol resins, polycarbonate resins, polyvinyl butyral resins, polyvinyl formal resins, shellacs, vinyl resins, acrylic resins. Rubber resins, waxes and other natural resins can be used. Two or more of these may be used in combination. Of these, vinyl copolymer obtained by copolymerization of acrylic monomers is preferred. Furthermore, a copolymer containing “carboxyl group-containing monomer”, “methacrylic acid alkyl ester”, or “acrylic acid alkyl ester” as a structural unit is also preferably used as the copolymer composition of the polymer binder.

<Surfactant>
A surfactant may be added to the ink composition of the present invention.
Examples of the surfactant include those described in JP-A Nos. 62-173463 and 62-183457. For example, anionic surfactants such as dialkylsulfosuccinates, alkylnaphthalenesulfonates, fatty acid salts, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols, polyoxyethylene / polyoxypropylene blocks Nonionic surfactants such as copolymers, and cationic surfactants such as alkylamine salts and quaternary ammonium salts. An organic fluoro compound having no polymerizable group may be used in place of the surfactant. The organic fluoro compound is preferably hydrophobic. Examples of the organic fluoro compounds include fluorine surfactants, oily fluorine compounds (eg, fluorine oil) and solid fluorine compound resins (eg, tetrafluoroethylene resin). No. (columns 8 to 17) and those described in JP-A Nos. 62-135826.

In addition to this, polymerization is not hindered to improve adhesion to recording media such as leveling additives, matting agents, waxes for adjusting film physical properties, polyolefins, PET, etc., if necessary. A tackifier or the like can be contained.
As the tackifier, specifically, a high molecular weight adhesive polymer described in JP-A-2001-49200, 5-6p (for example, (meth) acrylic acid and an alkyl group having 1 to 20 carbon atoms). An ester with an alcohol having, an ester of (meth) acrylic acid with an alicyclic alcohol having 3 to 14 carbon atoms, a copolymer comprising an ester of (meth) acrylic acid with an aromatic alcohol having 6 to 14 carbon atoms) And a low molecular weight tackifying resin having a polymerizable unsaturated bond.

  The ink composition of the present invention preferably has an ink viscosity of 7 mPa · s to 30 mPa · s, more preferably 7 mPa · s to 20 mPa · s at the temperature at the time of ejection, and is appropriately adjusted to be in the above range. It is preferable to adjust and determine the composition ratio. The ink viscosity at 25 ° C. to 30 ° C. is 35 mPa · s to 500 mPa · s, preferably 35 mPa · s to 200 mPa · s. By setting the viscosity at room temperature high, even when a porous recording medium is used, ink penetration into the recording medium can be prevented, uncured monomer can be reduced, and odor can be reduced. Can be suppressed, and as a result, the image quality is improved.

  The surface tension of the ink composition of the present invention is preferably 20 mN / m to 30 mN / m, more preferably 23 mN / m to 28 mN / m. When recording on various recording media such as polyolefin, PET, coated paper, and uncoated paper, 20 mN / m or more is preferable from the viewpoint of bleeding and penetration, and the wettability is preferably 30 mN / m or less.

The ink composition of the present invention thus prepared can be suitably used as an inkjet recording ink. When used as an ink for ink jet recording, the ink composition is ejected onto a recording medium by an ink jet printer, and then the ejected ink composition is irradiated with an active energy ray and cured to perform recording.
The ink composition of the present invention may be used in addition to image formation with ink. In particular, since the ink composition of the present invention is cured by irradiation with energy rays such as ultraviolet rays to obtain a cured film having high strength, for example, the ink composition is formed into an ink receiving layer (image portion) of a lithographic printing plate, etc. May be used for

(Image forming method)
Next, an image forming method suitable for the ink composition of the present invention will be described below.
The image forming method according to the present invention includes an ink application step of applying the above-described ink composition of the present invention onto a recording medium by an inkjet method, and irradiating the applied ink composition with active energy rays as necessary. And a curing step of curing the ink composition.

  In the image forming method according to the present invention, it is preferable that the ink composition is heated to 40 ° C. to 80 ° C. to lower the viscosity of the ink composition to 7 mPa · s to 30 mPa · s and then ejected. By using this, high injection stability can be realized. The control range of the ink composition temperature is preferably set temperature ± 5 ° C., more preferably set temperature ± 2 ° C., and still more preferably set temperature ± 1 ° C.

  The ink jet recording apparatus suitable for the image forming method according to the present invention preferably includes means for stabilizing the temperature of the ink composition, and the portion to be maintained at a constant temperature is ejected from an ink tank (an intermediate tank if an intermediate tank is provided). All piping systems and members up to the surface are targeted.

  The temperature control method is not particularly limited, but for example, it is preferable to provide a plurality of temperature sensors in each piping portion and perform heating control according to the ink composition flow rate and the environmental temperature. Moreover, it is preferable that the head unit to be heated is thermally shielded or insulated so that the apparatus main body is not affected by the temperature from the outside air. In order to shorten the printer start-up time required for heating or to reduce the loss of heat energy, it is preferable to insulate from other parts and reduce the heat capacity of the entire heating unit.

  Next, irradiation conditions of active energy rays will be described. A basic irradiation method is disclosed in JP-A-60-132767. Specifically, a light source is provided on both sides of the head unit, and the head and the light source are scanned by a shuttle method. Irradiation is performed after a certain period of time after ink landing. Further, the curing is completed by another light source that is not driven. In WO99 / 54415, as an irradiation method, a method using an optical fiber or a method in which a collimated light source is applied to a mirror surface provided on the side surface of the head unit to irradiate the recording unit with UV light is disclosed. In the present invention, these irradiation methods can be used.

  In the present invention, the ink composition is heated to a constant temperature, and the time from landing to irradiation is desirably 0.01 seconds to 0.5 seconds, preferably 0.01 seconds to 0.3 seconds. More preferably, the irradiation is performed after 0.01 seconds to 0.15 seconds. Thus, by controlling the time from landing to irradiation to an extremely short time, it is possible to prevent the landing ink from bleeding before being cured. In addition, since the ink composition can be exposed to a porous recording medium before it penetrates deeper than the light source reaches, unreacted monomer residue can be suppressed, and as a result, odor can be reduced. it can. By using the image forming method described above and the ink composition of the present invention in combination, a great synergistic effect is brought about. In particular, when an ink composition having an ink viscosity of 35 MP · s to 500 MP · s at 25 ° C. is used, a great effect can be obtained. By adopting such a recording method, the dot diameter of the landed ink can be kept constant even on various recording media having different surface wettability, and the image quality is improved. In addition, in order to obtain a color image, it is preferable to superimpose in order from the color with the lowest brightness.

  The ink jet recording apparatus that can be used in the image forming method according to the present invention is not particularly limited, and a commercially available ink jet recording apparatus can be used. That is, in the present invention, recording can be performed on a recording medium using a commercially available inkjet recording apparatus.

(recoding media)
The recording medium to which the ink composition of the present invention can be applied is not particularly limited, and various non-absorbent resin materials used for ordinary non-coated paper, coated paper, and so-called soft packaging, or films thereof. A resin film molded into a shape can be used, and examples of various plastic films include PET film, OPS film, OPP film, ONy film, PVC film, PE film, and TAC film. In addition, examples of the plastic that can be used as the recording medium material include polycarbonate, acrylic resin, ABS, polyacetal, PVA, and rubbers. Metals and glasses can also be used as a recording medium.

[Printed matter]
The printed matter of the present invention has the recording medium and an image formed on the recording medium with the ink composition. That is, for example, the ink composition is applied to a recording medium by an ink jet printer, and then, preferably, the applied ink composition is cured by irradiation or heating with active energy rays to obtain a printed matter. it can.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the forms in these examples.

  Unless otherwise specified, “part” and “%” are based on mass. The weight average molecular weight was measured by gel permeation chromatography (GPC). GPC uses HLC-8220GPC (manufactured by Tosoh Corp.), and TSKgeL SuperAWM-H (trade name, manufactured by Tosoh Corp.) is connected in series as a column, and N-methyl is used as an eluent. Pyrrolidone was used. The conditions were as follows: the sample concentration was 0.1% by mass, the flow rate was 0.5 ml / min, the sample injection amount was 10 μl, the measurement temperature was 40 ° C., and the RI detector was used. In addition, the calibration curve is “Standard sample TSK standard, polystyrene” manufactured by Tosoh Corporation: “F-80”, “F-10”, “F-2”, “A-2500”, “A-1000”. Made from 5 samples.

<Preparation of pigment dispersion>
(1. Preparation of pigment dispersion 1)
First, Pigment Dispersion 1 was prepared with the following composition.
In the following composition, first, a pigment and a pigment dispersant are added to the acrylate monomer, and the mill base is prepared by stirring until uniform with a high speed mixer, and then the obtained mill base is dispersed for about 1 hour in a horizontal sand mill. Pigment dispersion 1 was prepared.
(composition)
・ IRGALITE BLUE GLVO (cyan pigment, manufactured by BASF Japan) 27 parts ・ Solspers 32000 (pigment dispersant, manufactured by Nihon Lubrizol Corporation) 9 parts ・ Phenoxyethyl acrylate 64 parts

(Synthesis Example 1: Synthesis of Synthesis of Polymer SP-1 which is (A) Polymer According to the Present Invention)
In a 500 ml three-necked round bottom flask equipped with a condenser and a stirrer, 21.62 g (135 mmol) of Bremer GLM (manufactured by NOF Corporation), polypropylene glycol (Mw = 3000) (Wako Pure Chemical Industries, Ltd.) 45.00 g (15 mmol) was added and dissolved in 160 ml of tetrahydrofuran (THF (manufactured by Wako Pure Chemical Industries, Ltd.)). To this, 5.30 g (31.5 mmol) of 1,6-hexamethylene diisocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.), 31.53 g (126 mmol) of 4,4-diphenylmethane diisocyanate (manufactured by Aldrich) Then, 0.1 g of dibutyltin dilaurate (manufactured by Wako Pure Chemical Industries, Ltd.) was added, and the mixture was heated and stirred at 60 ° C. for 6 hours. Then, it heated to 70 degreeC, tetrahydrofuran (THF (made by Wako Pure Chemical Industries Ltd.)) 100ml was added, and also it heated for 2 hours. FM-0411 (monohydric alcohol containing siloxane structure (manufactured by Chisso Corporation)) and 50 ml were added and stirred for 30 minutes. The reaction solution was poured into 3 liters of hexane while stirring to precipitate a white polymer, and unreacted raw materials were removed. The polymer was filtered off, washed with water, and dried under vacuum to obtain 116 g of polymer. The synthesized specific polyurethane resin is represented by (SP-1) in the following table.
When the molecular weight was measured by gel permeation chromatography (GPC), the weight average molecular weight (polystyrene standard) was 40,000, and it was confirmed that no raw material remained. The composition ratio of the polymer was confirmed by ¹ H NMR, and the polysiloxane structure at the polymer terminal was confirmed.

(Synthesis Examples 2-7: Synthesis of Polymers SP-2 to SP-6 and SP-9 which are (A) Polymers According to the Present Invention)
The kind of monomer used for the synthesis of the polymer SP-1 is changed to the one described in Table 1 below, and the amount of each component used is the molar ratio of each structural unit described in (a) the exemplary compound of the polymer. Polymers SP-2 to SP-6 were synthesized in the same manner as the polymer SP-1, except that the adjustment was performed as described above. The weight average molecular weight by GPC of the produced | generated polymer (polymer) is as having shown in the below-mentioned structural formula, The terminal structure was confirmed similarly to SP-1, respectively.
In the table, FM-0411 and FM-0421 (both manufactured by Chisso Corporation) are monovalent alcohols containing a siloxane structure marketed under the same name. 2- (Perfluorohexyl) ethanol (a monovalent alcohol containing a fluorine-substituted hydrocarbon group) and 1-hexadecanol (a monovalent alcohol containing a long-chain alkyl group) are both Wako Pure Chemical Industries, Ltd. The reagent made from this was used. HDI is 1,6 hexamethylene diisocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.), MDI is 4,4-diphenylmethane diisocyanate (manufactured by Aldrich), and 1,4-PDI is 1,4-phenylene. Diisocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.), IPDI is isophorone diisocyanate (manufactured by Wako Pure Chemical Industries, Ltd.), Bremer GLM (manufactured by NOF Corporation), EE3000A (trade name: epoxy) Ester 3000A (manufactured by Kyoeisha Chemical Industry Co., Ltd.) is a commercially available diol compound. EDA is ethylenediamine (manufactured by Aldrich), which is a commercially available diamine compound.

M-1, M-2, and M-3 (all diol compounds) were synthesized by the following method.
~ Method for synthesizing M-1, M-2, and M-3 ~
2,2-dimethyl-1,3-dioxolane-4-methanol (manufactured by Wako Pure Chemical Industries, Ltd.) as a starting material, Tetrahedron Letters, 1985, 26, 3095, Angelwandte Chemie, 2007, 119, 4229, J Am. Chem. Soc. 2002, 124, 1590, refer to acryloylation, styryl group introduction, vinyl etherification, and then deacetalization using hydrogen chloride (methanol solution) etc. Got. The reaction steps and structures of M-1, M-2, and M-3 are shown below.

The structure of the obtained (A) polymer is shown below. (In the formula, R represents a commercially available alcohol compound used for synthesis: FM-0411 or n-butyl group derived from FM-0411 (manufactured by Chisso)) Among the polymers having the structures shown below (SP-4) is a reference polymer, and Example 4 using the reference polymer (SP-4) is a reference example.

(Synthesis Example 8: Synthesis of Comparative Polymer A-1)
Resin A-1 was synthesized according to Synthesis Example 1 of JP-A No. 2010-70692. Resin A-1 is a comparative polymer represented by the following structure, which does not contain any of the specific structures (a1), (a2), and (a3) of the present invention at the ends of the main chain.

<Example 1>
(Preparation of ink composition)
An ink composition of Example 1 was obtained by stirring and mixing the following components for 2 hours, confirming that there was no dissolution residue, filtering through a membrane filter, and removing coarse particles. The viscosity of the ink composition at the ink discharge temperature (45 ° C.) was in the range of 20 mPa · s.

-10 parts of the pigment dispersion 1-34 parts of N-vinylcaprolactam (NVC)-30 parts of 2-phenoxyethyl acrylate (PEA)-11 parts of isobornyl acrylate (IBOA)-Polymer SP-1 (in the synthesis example 1) Compound obtained) 2 parts ・ Lucirin TPO (polymerization initiator: manufactured by BASF Japan) 8 parts ・ benzophenone (polymerization initiator: manufactured by BASF Japan) 3 parts ・ Irgacure 184 (polymerization initiator: manufactured by BASF Japan) 2 parts

<Examples 2 to 10>
(Preparation of ink compositions of Examples 2 to 10)
Of the components in the preparation of the ink composition of Example 1, the examples except that the types and addition amounts of the (A) polymer and (B) other polymerizable compound according to the present invention were changed as shown in Table 2 below. In the same manner as in Example 1, ink compositions of Examples 2 to 10 were prepared.

<Comparative Example 1>
(Preparation of ink composition of Comparative Example 1)
An ink composition of Comparative Example 1 was prepared in the same manner as in Example 1 except that Comparative Polymer A-1 was used instead of Polymer SP-1 in the preparation of the ink composition of Example 1.

<Comparative example 2>
(Preparation of ink composition of Comparative Example 2)
An ink composition of Comparative Example 2 was prepared in the same manner as Comparative Example 1 except that Comparative Polymer A-1 was not added and PEA was increased.

<Evaluation of ink composition>
(Image recording)
First, each prepared ink composition was filtered with a filter having an absolute filtration accuracy of 2 μm.
Inkjet images were recorded using a UV curable ink inkjet printer LUXELJET UV250 (manufactured by Fuji Film Graphic Systems). A 100% solid image was printed on various recording media at a resolution of 600 × 450 dpi and a size of 2 m × 1 m. The apparatus performs drawing by operating an ink jet head, and one UV lamp is mounted on each end of the head, and two UV lamps are irradiated by one head operation. It has a form like this. The solid image was formed by alternately repeating ink droplets and UV irradiation by two lamps at the same location on the support 8 times. The lamp was equipped with SUB ZERO 085 H bulb lamp unit manufactured by Integration Technology, and the lamp intensity at the front and rear was set to level 3. When the road surface illuminance was measured during printing, it was 980 mW / cm ² . The time from ejection to exposure was 0.2 to 0.3 seconds. The discharge amount per drop was in the range of 6 to 42 pL. Moreover, the recording medium was selected according to each evaluation mentioned later.

  Under these conditions, the hardness, suitability for drilling, and flexibility of the image formed using the ink composition were evaluated by the following methods. The evaluation results are shown in Table 3 below.

(Evaluation of hardness)
Using a polycarbonate (PC) substrate (size: 10 cm × 10 cm, thickness: 500 μm) as a recording medium, an image was formed according to the above-described image recording. The obtained image part was evaluated according to the method described in JIS K5600-5-4. The evaluation criteria are as follows.

~Evaluation criteria~
5: 2H or more 4: H or more and less than 2H 3: F or more but less than H 2: HB or more but less than F 1: less than HB Among the above criteria, 4 and 5 are practically problematic ranges.

(Evaluation of drilling suitability)
A polycarbonate (PC) substrate (size: 10 cm × 10 cm, thickness: 500 μm) was used as a recording medium, and 20 images were prepared according to the above-described image recording. The obtained image part was punched out with a punch (Kokuyo Co., Ltd .: PN83NB), and the number of cracks around the hole was visually examined. The evaluation criteria are as follows.

~Evaluation criteria~
5: In all samples, cracks were not present 4: Cracks were observed in 1-2 samples 3: Cracks were observed in 3-4 samples 2: Cracks were observed in 5-9 samples 1: Ten or more samples were cracked. Of the above criteria, 4 and 5 are practically acceptable ranges.

(Evaluation of flexibility)
Images were formed according to the above-mentioned image recording using Fasson PE (Fasson polyethylene film: film thickness 100 μm) as a recording medium. The recording medium on which the image area is formed is cut into an axial length of 5 cm and a width of 2.5 cm, and stretched at a speed of 30 cm / min using a tensile tester (manufactured by Shimadzu Corporation, Autograph AGS-J). The elongation at which the (cured film) breaks was measured. The state of elongation from the initial length to twice the length was defined as 100% elongation.

~Evaluation criteria~
5: Stretch ratio 300% or more 4: Stretch ratio 200% or more but less than 300% 3: Stretch ratio 150% or more but less than 200% 2: Stretch ratio 100% or more but less than 150% 1: Stretch ratio 100% or less Of the above criteria, 4 and 5 is a practically non-problem range.

<Examples 11 to 17>
(Preparation of ink compositions of Examples 11 to 17)
Among the components in the preparation of the ink composition of Example 1, Example 1 was used except that the compounds shown in Table 4 below were used in the same amount as SP-1 in Example 1 as the polymer (A) according to the present invention. In the same manner, ink compositions of Examples 11 to 17 were prepared and evaluated in the same manner as in Example 1. The results are shown in Table 4 below.

  As is apparent from the results of Tables 3 and 4, the ink composition of the present invention can achieve both the hardness and flexibility of the image area within a favorable range, and has high drilling suitability. Even if a larger stress such as the above is applied, cracks in the image portion can be suppressed.

(Synthesis Example 9: Synthesis of Exemplary Compound SP-17 which is (A) Polymer According to the Present Invention)
N-vinylcaprolactam (manufactured by BASF) 273.48 g, FM-0411 (manufactured by JNC, one-end alcoholated dimethylsiloxane) 11.76 g, Bremer GLM (manufactured by NOF Corporation, glycerin monomethacrylate) 46.17 g, UV- 12 (manufactured by Chromachem, polymerization inhibitor) and 69.16 g of xylylene diisocyanate were weighed and added to a 1 L three-necked flask equipped with a condenser and a thermometer, and reacted at 60 ° C. for 4 hours. Thereafter, 1.33 g of Neostan U-600 (manufactured by Nitto Kasei Co., Ltd.) was added, and the reaction was further performed for 4 hours. Ethoxyethoxyethanol / ethoxyethoxyethyl acrylate = 1/9 was added and diluted to a solid content concentration of 15% to obtain a monomer solution of SP-17. The obtained polymer SP-17 had a styrene-converted weight average molecular weight of 42,000 as measured by GPC.

(Synthesis Example 10: Synthesis of Exemplary Compound SP-18 which is (A) Polymer According to the Present Invention)
Ethoxyethoxyethyl acrylate (manufactured by Wako Pure Chemical Industries, Ltd.) 127.82 g, FM-0411 2.24 g, Bremer GLM 11.65 g, p-benzoquinone 0.16 g, hexamethylene diisocyanate 2.6 g, diphenylmethane diisocyanate 15. 47 g was weighed and added to a 300 mL three-necked flask equipped with a condenser and a thermometer, and reacted at 60 degrees for 4 hours. Thereafter, 0.48 g of Neostan U-600 (manufactured by Nitto Kasei Co., Ltd.) was added, and the reaction was further performed for 4 hours. Ethoxyethoxyethanol / ethoxyethoxyethyl acrylate = 1/9 was added and diluted to a solid content concentration of 15% to obtain a monomer solution of SP-18. The obtained polymer SP-18 had a styrene-converted weight average molecular weight of 36,000 as measured by GPC.

(Synthesis Example 11: Synthesis of Exemplary Compound SP-19 which is (A) Polymer According to the Present Invention)
Hexamethylene diisocyanate 91.93 g, FM-0411 2.76 g, Blenmer GLM 15.57 g, p-benzoquinone 0.13 g, xylylene diisocyanate 15.81 g, diphenylmethane diisocyanate 5.26 g were cooled with a thermometer A weighed amount was added to the 300 mL three-necked flask provided, and the reaction was performed at 60 degrees for 4 hours. Thereafter, 0.39 g of Neostan U-600 (manufactured by Nitto Kasei Co., Ltd.) was added, and the reaction was further performed for 4 hours. Ethoxyethoxyethanol / ethoxyethoxyethyl acrylate = 1/9 was added and diluted to a solid concentration of 15% to obtain a monomer solution of SP-19. The obtained polymer SP-19 had a weight-average molecular weight in terms of styrene of 28,000 as measured by GPC.

<Examples 18 to 20>
(Preparation of ink compositions of Examples 18 to 20)
Among the respective components in the preparation of the ink composition of Example 1, the exemplary compounds (SP-17), (SP-18) and (SP) obtained by the synthesis example 8 to the synthesis example 11 by polymerizing (A) according to the present invention. Ink compositions of Examples 18 to 20 were prepared in the same manner as in Example 1 except that SP-19) was used in the same amount as SP-1 in Example 1, and evaluated in the same manner as in Example 1. . The results are shown in Table 5 below.

  As is apparent from the results in Table 5, the ink composition of the present invention can achieve both the hardness and flexibility of the image area within a favorable range even when the type of the polymer is changed, and the punching. The processability is high, and cracks in the image portion can be suppressed even when a larger stress such as drilling is applied.

Claims (10)

(A) a polymer containing a urethane bond or a urea bond in the main chain structure and having a polymerizable group in the side chain;
(B) a polymerizable compound other than (A),
(C) a polymerization initiator,
The (A) polymer is an ink composition in which at least one terminal of the main chain structure has any one of (a1) a fluorine-substituted hydrocarbon group and (a2) a group containing a siloxane structure.   The ink composition according to claim 1, wherein the polymerizable group of the (A) polymer is a (meth) acrylic acid ester group. (A) the polymer, at least one of the ends of the main chain structure, (a2) the ink composition according to claim 1 or claim 2 having a group containing a siloxane structure. (A) the polymer and the (B) any one of claims 1 to 3 content of the (A) polymer in the total content of the polymerizable compound is 0.2 wt% to 10 wt% 2. The ink composition according to item 1. The ink composition according to any one of claims 1 to 4 , wherein a content of the polymerizable group in the polymer (A) is 0.3 mmol / g or more. The ink composition according to any one of claims 1 to 5 , wherein the content of the monofunctional monomer in the polymerizable compound (B) is 60 % by mass to 100% by mass. The ink composition according to any one of claims 1 to 6 , further comprising (D) a colorant. The ink composition according to any one of claims 1 to 7 , which is for inkjet recording. An image forming method comprising an ink application step of applying the ink composition according to any one of claims 1 to 8 onto a recording medium by an inkjet method. A printed matter obtained by the image forming method according to claim 9 .