Photoresponsive polymer

Abstract

To provide a photoresponsive polymer which sufficiently secures photoresponsiveness to be fluidized and un-fluidized by light irradiation, improves fixability when used in a toner, and has excellent image stability and good color reproducibility.SOLUTION: There is provided a photoresponsive polymer which includes a structural unit represented by the following general formula (1) and is fluidized and un-fluidized reversibly by light irradiation. Z1 and Z2 are CH or N and Z1≠Z2, R1 is an aromatic hydrocarbon group having a substituent Ra selected from the group consisting of an alkyl group, an alkoxy group, and a halogen atom, respectively, in two ortho-positions with respect to Z1, R2 is a substituted or unsubstituted aromatic heterocyclic group, and at least one of the R1 and R2 is bonded to a group containing a structure derived from a polymerizable group.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a photo-responsive polymer that is fluidized by light irradiation and reversibly non-fluidized.

Background Art

[0002] Photo-responsive materials are known as materials whose fluidity changes upon light irradiation. For example, the azobenzene compounds (azobenzene derivatives) described in Patent Document 1 or 2 undergo a phase change accompanying an isomerization reaction by light irradiation.

[0003] It is considered that the resulting molecular structure change induces a phase transition from the solid state to the fluid state. Further, by re-irradiating with light while changing the wavelength, heating, or leaving it in the dark at room temperature, a reverse reaction occurs and it solidifies again.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, it has been found that the azobenzene derivatives described in Patent Document 1 or 2 have relatively low molecular weights, so that their toughness as materials is low and sufficient fixing properties cannot be achieved. Further, it has been found that all of the azobenzene derivatives described in Patent Documents 1 and 2 have yellow to orange coloring, and there is a problem that the desired color cannot be reproduced when applied to industrial products such as toners and adhesives.

[0006] Therefore, an object of the present invention is to provide a photo-responsive polymer that is fluidized by light irradiation, sufficiently ensures photo-responsiveness to be reversibly non-fluidized, improves fixing properties when used as a toner, is excellent in image stability, and has good color reproducibility.

Means for Solving the Problems

[0007] In view of the above problems, the present inventors have intensively conducted research. As a result, they have found that the above problems can be solved by a polymer having a predetermined structural unit derived from an azomethine derivative, and have completed the present invention.

[0008] That is, the present invention is a photo-responsive polymer that includes a structural unit represented by the following general formula (1) and is fluidized by light irradiation and reversibly non-fluidized.

[0009]

Chemical formula

[0010] In the formula, Z 1 and Z 2 are CH or N, and Z 1 ≠Z 2 and R 1 is an aromatic hydrocarbon group having substituents R 1 selected from the group consisting of an alkyl group, an alkoxy group, and a halogen atom at two ortho positions with respect to Z a respectively, R 2 is a substituted or unsubstituted aromatic heterocyclic group, at least one of the above R 1 and the above R 2 is bonded to a group containing a structure derived from a polymerizable group.

Effects of the Invention

[0011] According to the present invention, there can be provided a photo-responsive polymer that is fluidized by light irradiation, sufficiently ensures photo-responsiveness to be reversibly non-fluidized, improves fixing property when used as a toner, has excellent image stability, and further has good color reproducibility.

Brief Description of Drawings

[0012]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0013] Hereinafter, preferred embodiments of the present invention will be described. In this specification, "X to Y" indicating a range means "X or more and Y or less". Further, in this specification, unless otherwise specified, measurements of operations and physical properties are performed under conditions of room temperature (20 to 25 ° C) / relative humidity 40 to 50% RH.

[0014] <Photo-responsive polymer> One embodiment of the present invention is a photo-responsive polymer that includes a structural unit represented by the following general formula (1) and is fluidized by light irradiation and reversibly non-fluidized.

[0015]

Chemical formula

[0016] In the formula, Z 1 and Z 2 are CH or N, Z 1 ≠Z 2 and R 1 is Z 1An aromatic hydrocarbon group having substituents R selected from the group consisting of alkyl groups, alkoxy groups, and halogen atoms at two ortho-positions with respect to a each, and R 2 is a substituted or unsubstituted aromatic heterocyclic group, wherein at least one of 1 said R 2 and said R

[0017] is bonded to a group containing a structure derived from a polymerizable group. 1 Here, when the general formula (1) is described using one of the following specific examples, as shown in the following formula, Z 1 (CH in the following formula) is bonded to an aromatic hydrocarbon group R such as a phenyl group 2 (N in the following formula) is bonded to an optionally substituted aromatic heterocyclic group R 2 . In the present embodiment, the aromatic hydrocarbon group R 1 has specific substituents R 1 on two carbon atoms at the ortho-position with respect to Z a (CH 3 group in the following formula) each. And R 1 has at least one bonding site to a group containing a structure derived from a polymerizable group not shown, as indicated by a dotted line thereon.

[0018] [Chemical formula]

[0019] In the present specification, the "photo-responsive polymer" may sometimes be simply referred to as a "polymer". By being a photo-responsive polymer containing a structural unit derived from such an azomethine derivative, it has sufficient photo-responsiveness to be fluidized by light irradiation and reversibly non-fluidized, improves the fixing property when used as a toner, has excellent image stability, and can further provide a photo-responsive polymer with good color reproducibility.

[0020] In this specification, "fluidized by light irradiation and reversibly defluidized" means changing from a non-fluid state to a fluid state by light irradiation and then returning to the non-fluid state. That is, the polymer of the present invention is in a non-fluid solid state when not irradiated with light at normal temperature and normal pressure, and softens and changes to a fluid state by light irradiation. When the light irradiation is stopped and left in a dark place at room temperature or under visible light irradiation, or heated, it returns to the non-fluid solid state. In this specification, the fluid state means a state that deforms under a small external force.

[0021] The mechanism by which such a technical effect is achieved is presumed to be as follows. However, the technical scope of the present invention is not limited to such a mechanism. That is, an azobenzene compound having a long-chain alkyl chain at the end, which is a conventional example, is a material that absorbs light and softens (photo phase transition) from a solid state, and it is considered that the photo phase transition occurs due to the collapse of the crystal structure by cis-trans isomerization. The azobenzene compounds described in Patent Document 1 or 2 cause a phase change along with the isomerization reaction by light irradiation, but the present inventors have found that such azobenzene compounds have a problem of low toughness as a material. Also, it has been found that there is a problem in that it shows strong absorption derived from n-π * transition in the visible light region and is colored orange, so it is difficult to reproduce the desired color when applied to industrial products.

[0022] In the present invention, a polymer containing a structural unit derived from an azomethine derivative is used. By doing so, it has been realized to provide a polymer that is fluidized by light irradiation, reversibly non-fluidized, highly tough, and has no significant coloring. Here, in a polymer containing a structural unit derived from an azomethine derivative, it is considered that the azomethine derivative absorbs light, and the heat energy released in the photoexcitation-deactivation process is transmitted to the repeating unit (structural unit) to which it binds (photo-thermal conversion), thereby inducing a reversible fluidization-non-fluidization phenomenon. In particular, when the polymer is in the trans form, in addition to the aforementioned photo-thermal conversion, trans-cis photoisomerization is more likely to occur by light irradiation, and a cis form with a low Tg is likely to be generated. When the non-fluid trans form (E) is irradiated with light and isomerizes to the cis form (Z), it is considered that the regular structure collapses due to many trans forms (E) changing to the cis form (Z), inducing a phase transition change, that is, a fluidization phenomenon. Also, it is considered that when the cis form (Z) returns to the trans form (E), a regular structure is formed again, inducing a non-fluidization phenomenon. Thereby, it is considered that a more efficient fluidization-non-fluidization phenomenon can be induced. Therefore, in order to induce the fluidization phenomenon, it is considered preferable that many trans forms (E) isomerize to the cis form (Z). However, generally, azomethine derivatives may have a faster cis-trans isomerization rate than azobenzene derivatives, and it was predicted that azomethine derivatives having unsubstituted benzene rings bonded to both ends of the C=N bond would be disadvantageous for inducing fluidization.

[0023] Therefore, in the present invention, in a polymer containing an azomethine derivative, an aromatic hydrocarbon group and an aromatic heterocyclic group are respectively provided at both ends of the C=N moiety, and a substituent R selected from the group consisting of an alkyl group, an alkoxy group, and a halogen atom is provided at two ortho positions of the aromatic hydrocarbon group a is introduced, whereby fluidization associated with the photoisomerization reaction can be efficiently induced. This is because by having the above-mentioned specific substituent R a at two ortho positions of the aromatic hydrocarbon group, compared to the case where it does not have the substituent or has the above-mentioned specific substituent R aCompared with the case of having [a certain condition], it is considered that the cis form is further stabilized and more cis form is generated.

[0024] By introducing the polymer of the present invention as a binder resin into the toner, a toner that can be fixed by light irradiation, has excellent fixing properties, excellent image storage properties, and high color reproducibility can be obtained. The specific substituent R at two ortho positions of the aromatic hydrocarbon group a By introducing [the substituent], the cis→trans reaction rate decreases, and further the cis form is stabilized, and more cis form can be generated. It is considered that this induces fluidization and promotes melting, thereby improving the fixing property and the image storage property. Furthermore, by introducing a substituent at the ortho position, an effect of strengthening the entanglement between the polymer chains is also exhibited, and it is presumed that the image stability is improved.

[0025] In one embodiment of the present invention, the photoreactive polymer has a structural unit derived from an azomethine derivative represented by the general formula (1) having a polymerizable group. That is, the R 1 and the R 2 Preferably, at least one of them includes at least one site bonded to a group containing a structure derived from a polymerizable group.

[0026] In one embodiment of the present invention, the photoreactive polymer has a structural unit derived from an azomethine derivative represented by the general formula (1) as a side chain in the repeating unit in the photoreactive polymer.

[0027] In one embodiment of the present invention, the photoreactive polymer has at least one site bonded to a group containing a structure derived from a polymerizable group at at least one of R 1 or R 2 in the structural unit represented by the general formula (1). For example, the aromatic hydrocarbon group constituting R 1 or R 2The aromatic heterocyclic group constituting the compound has at least one bonding site to a group containing a structure derived from a polymerizable group. Examples of the structure derived from a polymerizable group include a structure derived from (meth)acrylate, a structure derived from olefin, or a structure derived from vinyl ester. In one embodiment of the present invention, the photoresponsive polymer contains a structure derived from (meth)acrylate. By virtue of such an embodiment, there is a technical effect that polymerization is easy.

[0028] In one embodiment of the present invention, the photoresponsive polymer has the following general formula (2):

[0029]

Chemical formula

[0030] and contains a structural unit represented by In the general formula (2), r 1 is a hydrogen atom or a methyl group, A is one of the following general formulas (1-1) to (1-4):

[0031]

Chemical formula

[0032] represented by any of them, where * represents a bonding point, G is a divalent group, Z 1 and Z 2 are CH or N, Z 1 ≠Z 2 and R 1 is an aromatic hydrocarbon group having substituents R 1 selected from the group consisting of an alkyl group, an alkoxy group, and a halogen atom at two ortho positions with respect to Z a respectively, R 2 is a substituted or unsubstituted aromatic heterocyclic group. By virtue of such an embodiment, the intended effect of the present invention can be efficiently achieved.

[0033] Here, the above general formula (1-2) will be described using one of the following specific examples. Typically, the following formula:

[0034] [Chemical formula]

[0035] is represented by. "R 1 -", "-Z 1 =Z 2 -", "-R 2 " are as described above. G as a divalent group is an oxyalkylene group having 6 carbon atoms, and is bonded to the structural unit derived from (meth)acrylate using this as a bonding point.

[0036] Hereinafter, the structural unit represented by the general formula (1), particularly the general formula (2), will be further described.

[0037] (Z 1 and Z 2 ) In one embodiment of the present invention, as described above, Z 1 and Z 2 are N or CH, provided that Z 1 ≠Z 2 . When Z 1 is CH and Z 2 is N, it tends to be excellent in photo-melting property, which is more preferable.

[0038] (R 1 and R 2 ) In one embodiment of the present invention, as described above, R 1 is an aromatic hydrocarbon group having a substituent R 1 selected from the group consisting of an alkyl group, an alkoxy group, and a halogen atom at two ortho positions with respect to Z a , and R 2 is a substituted or unsubstituted aromatic heterocyclic group.

[0039] In one embodiment of the present invention, as the aromatic hydrocarbon group, Z 1 is not particularly limited as long as it has a predetermined substituent R a at two ortho positions with respect to it, but those derived from aromatic hydrocarbons having 6 to 30 carbon atoms are preferable, and examples thereof include groups derived from structures such as benzene, naphthalene, anthracene, phenanthrene, pyrene, and biphenyl. Among them, groups derived from benzene, naphthalene, and phenanthrene are preferable from the viewpoints that packing between molecular chains is likely to occur, high thermal motility is exhibited when trans-cis isomerization occurs, and a fluidization phenomenon is likely to be induced.

[0040] The carbon number of the alkyl group as the above R a is not particularly limited, but it is, for example, an alkyl group having 1 to 10 carbon atoms, preferably an alkyl group having 1 to 5 carbon atoms. The carbon number of the alkoxy group as the above R a is not particularly limited, but it is, for example, an alkoxy group having 1 to 10 carbon atoms, preferably an alkoxy group having 1 to 5 carbon atoms. If it is within the above range, the effects of the present invention can be obtained more remarkably. Also, it is preferable because synthesis is easy. Therefore, in a preferred embodiment of the present invention, R a is an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a halogen atom. Among them, since fluidization is more likely to occur and the fixing property and image stability when used in a toner are more excellent, R a is preferably an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms.

[0041] Note that the substituents R 1 present at two ortho positions with respect to Z a may be the same or different from each other. It is preferable that both of the two substituents R a are selected from the group consisting of an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, and a halogen atom.

[0042] Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an isobutyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an isopropyl group, a sec-butyl group, a t-butyl group and the like. Examples of the alkoxy group having 1 to 10 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group, an n-pentyloxy group, an n-hexyloxy group, an n-heptyloxy group, an n-octyloxy group, an n-nonyloxy group, an n-decyloxy group, a 1-methylpentyloxy group, a 4-methyl-2-pentyloxy group and the like. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like.

[0043] In one embodiment of the present invention, the aromatic heterocyclic group is not particularly limited, but preferably has 2 to 30 carbon atoms. Also, those having a high electron-donating property are preferred, and examples include those derived from the structures of thiophene, furan, pyrrole, pyrazole, imidazole, pyridine, pyrimidine, pyrazine, triazine, benzothiophene, benzimidazole, indole, isoindole, quinoline, isoquinoline, quinazoline, quinoxaline, naphthyridine, acridine, carbazole, dibenzothiophene and the like.

[0044] In one embodiment of the present invention, the aromatic hydrocarbon group is R aIt may also have other substituents. Further, the aromatic heterocyclic group may be unsubstituted or may have substituents. These substituents are not particularly limited, and examples thereof include a halogen atom, a cyano group, a nitro group, an amino group, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, an alkylamino group having 1 to 10 carbon atoms, a dialkylamino group having 2 to 10 carbon atoms, an acyl group having 2 to 19 carbon atoms, and an alkoxycarbonyl group having 2 to 19 carbon atoms. Preferably, they are a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, a dialkylamino group having 2 to 10 carbon atoms, an acyl group having 2 to 19 carbon atoms, and an alkoxycarbonyl group having 2 to 19 carbon atoms. At this time, it is preferable that at least one of the above substituents is a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, or a dialkylamino group having 2 to 10 carbon atoms. By having such a structure, cis-trans isomerization is more likely to proceed, and fluidization is more likely to occur. Among these, due to their high thermal motility, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, or a dialkylamino group having 2 to 10 carbon atoms is more preferable.

[0045] More preferably, the number of carbon atoms of the above substituents is such that the alkyl group is an alkyl group having 1 to 12 carbon atoms, and even more preferably, an alkyl group having 4 to 8 carbon atoms. Further, more preferably, the alkoxy group is an alkoxy group having 1 to 12 carbon atoms, and even more preferably an alkoxy group having 4 to 8 carbon atoms. Further, more preferably, the dialkylamino group is a dialkylamino group having 2 to 8 carbon atoms, and even more preferably a dialkylamino group having 4 to 6 carbon atoms. More preferably, the acyl group is an acyl group having 2 to 13 carbon atoms, and even more preferably an acyl group having 5 to 13 carbon atoms. Further, more preferably, the alkoxycarbonyl group is an alkoxycarbonyl group having 2 to 13 carbon atoms, and even more preferably an alkoxycarbonyl group having 5 to 13 carbon atoms is even more preferable. By introducing a long-chain substituent in this way, the crystal is likely to collapse, the photo-melting property is improved, and the fixing property is improved.

[0046] Examples of alkyl groups having 1 to 18 carbon atoms are not particularly limited, and include, for example, linear alkyl groups such as methyl group, ethyl group, n-propyl group, n-butyl group, isobutyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group; branched alkyl groups such as isopropyl group, sec-butyl group, t-butyl group, 1-methylpentyl group, 4-methyl-2-pentyl group, 3,3-dimethylbutyl group, 2-ethylbutyl group, 1-methylhexyl group, t-octyl group, 1-methylheptyl group, 2-ethylhexyl group, 2-propylpentyl group, 2,2-dimethylheptyl group, 2,6-dimethyl-4-heptyl group, 3,5,5-trimethylhexyl group, 1-methyldecyl group, 1-hexylheptyl group.

[0047] Examples of alkoxy groups having 1 to 18 carbon atoms include linear alkoxy groups such as methoxy group, ethoxy group, n-propoxy group, n-butoxy group, n-hexyloxy group, n-heptyloxy group, n-octyloxy group, n-nonyloxy group, n-decyloxy group, n-undecyloxy group, n-dodecyloxy group, n-tridecyloxy group, n-tetradecyloxy group, n-pentadecyloxy group, n-hexadecyloxy group; branched alkoxy groups such as 1-methylpentyloxy group, 4-methyl-2-pentyloxy group, 3,3-dimethylbutyloxy group, 2-ethylbutyloxy group, 1-methylhexyloxy group, t-octyloxy group, 1-methylheptyloxy group, 2-ethylhexyloxy group, 2-propylpentyloxy group, 2,2-dimethylheptyloxy group, 2,6-dimethyl-4-heptyloxy group, 3,5,5-trimethylhexyloxy group, 1-methyldecyloxy group, 1-hexylheptyloxy group.

[0048] Examples of alkylamino groups having 1 to 10 carbon atoms include, for example, methylamino group, ethylamino group, n-propylamino group, n-butylamino group, isobutylamino group, n-hexylamino group, n-heptylamino group, n-octylamino group, n-nonylamino group, n-decylamino group, and the like.

[0049] Examples of dialkylamino groups having 2 to 10 carbon atoms include, for example, dimethylamino group, diethylamino group, di-n-propylamino group, di-n-butylamino group, di-isobutylamino group, methylethylamino group, and the like.

[0050] Examples of acyl groups having 2 to 19 carbon atoms are saturated or unsaturated straight-chain or branched-chain acyl groups, and include, for example, acetyl group, propanoyl group (propionyl group), butanoyl group (butyryl group), isobutanoyl group (isobutyryl group), pentanoyl group (valeryl group), isopentanoyl group (isovaleryl group), sec-pentanoyl group (2-methylbutyryl group), t-pentanoyl group (pivaloyl group), hexanoyl group, heptanoyl group, octanoyl group, t-octanoyl group (2,2-dimethylhexanoyl group), 2-ethylhexanoyl group, nonanoyl group, isononanoyl group, decanoyl group, isodecanoyl group, undecanoyl group, lauroyl group, myristoyl group, palmitoyl group, stearoyl group, behenoyl group, undecylenoyl group, oleoyl group, and the like.

[0051] Examples of the alkoxycarbonyl group having 2 to 19 carbon atoms include linear or branched ones, such as linear alkoxycarbonyl groups like methoxycarbonyl group, ethoxycarbonyl group, n-butoxycarbonyl group, n-hexyloxycarbonyl group, n-heptyloxycarbonyl group, n-octyloxycarbonyl group, n-nonyloxycarbonyl group, n-decyloxycarbonyl group, n-undecyloxycarbonyl group, n-dodecyloxycarbonyl group, n-tridecyloxycarbonyl group, n-tetradecyloxycarbonyl group, n-pentadecyloxycarbonyl group, n-hexadecyloxycarbonyl group: 1-methylpentyloxycarbonyl group, 4-methyl-2-pentyloxycarbonyl group, 3,3-dimethylbutyloxycarbonyl group, 2-ethylbutyloxycarbonyl group, 1-methylhexyloxycarbonyl group, t-octyloxycarbonyl group, 1-methylheptyloxycarbonyl group, 2-ethylhexyloxycarbonyl group, 2-propylpentyloxycarbonyl group, 2,2-dimethylheptyloxycarbonyl group, 2,6-dimethyl-4-heptyloxycarbonyl group, 3,5,5-trimethylhexyloxycarbonyl group, 1-methyldecyloxycarbonyl group, 1-hexylheptyloxycarbonyl group and other branched alkoxycarbonyl groups.

[0052] In a preferred embodiment of the present invention, R 2 is a carbon atom constituting the ring structure of the aromatic heterocyclic group, adjacent to the carbon atom bonded to the carbon atom or nitrogen atom of Z 2 and preferably has at least one carbon atom bonded to a hydrogen atom. That is, it is preferable that at least one carbon atom adjacent to the carbon atom in the aromatic heterocyclic structure bonded to Z 2 is bonded to a hydrogen atom. Thereby, since the cis isomer is more stabilized, the fluidization accompanying the photoisomerization can be induced more effectively, and the effects of the present invention can be obtained more remarkably. More preferably, R 2 is a carbon atom constituting the ring structure of the aromatic heterocyclic group, adjacent to the carbon atom of Z 2It is bonded adjacent to a carbon atom bonded to a carbon atom or a nitrogen atom, and has two carbon atoms bonded to a hydrogen atom. Thereby, the effects of the present invention can be obtained more remarkably.

[0053] (r 1 ) In one embodiment of the present invention, as described above, r in the general formula (2) 1 is a hydrogen atom or a methyl group. In such an embodiment, from the viewpoint of high fluidity and excellent fixing property when trans-cis isomerization occurs, it is preferably a hydrogen atom.

[0054] (A) In one embodiment of the present invention, as described above, A is

[0055]

Chemical formula

[0056] any of them, * represents a bonding point, G is a divalent group, Z 1 and Z 2 are CH or N, Z 1 ≠Z 2 and R 1 is an aromatic hydrocarbon group having substituents R 1 selected from the group consisting of an alkyl group, an alkoxy group, and a halogen atom at two ortho positions with respect to Z a respectively, R 2 is a substituted or unsubstituted aromatic heterocyclic group.

[0057] In one embodiment of the present invention, when G is a divalent group, there is no particular limitation, but it is preferably an alkylene group having 1 to 18 carbon atoms or an oxyalkylene group having 1 to 18 carbon atoms. By virtue of such an embodiment, the polymer of the present invention has high thermal motility and excellent photo-melting properties. In one embodiment of the present invention, G is an alkylene group having 2 to 16 carbon atoms, an alkylene group having 3 to 14 carbon atoms, or an alkylene group having 4 to 12 carbon atoms. In one embodiment of the present invention, the oxyalkylene group is -(E-O) n - and is represented by, where E is an alkylene group having 1 to 18 (2 to 16, 3 to 14, or 4 to 12) carbon atoms, n is 1 to 3, and preferably 1. Preferably, the side of the oxygen atom becomes the bonding point of the general formulas (1-2) and (1-4).

[0058] In one embodiment of the present invention, as an example of the alkylene group having 1 to 18 carbon atoms, a group obtained by removing one hydrogen atom from the groups described as examples of the alkyl group having 1 to 18 carbon atoms is suitable.

[0059] In a preferred embodiment of the present invention, A has a structure represented by the general formula (1-1) or the general formula (1-2). It is preferable that the polymerizable site is on the side of the aromatic hydrocarbon group because fluidization is likely to occur by light irradiation.

[0060] In one embodiment of the present invention, when A is represented by the general formula (1-1) or the general formula (1-2), R 2 is preferably a structure represented by the following formula.

[0061] [Chemical formula]

[0062] In the formula, R cis a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or an alkoxy group having 1 to 18 carbon atoms. Thereby, the intended effects of the present invention (particularly, the effects of improving fixability and image stability when used in a toner) can be efficiently achieved. Among them, an alkyl group having 1 to 18 carbon atoms is preferable.

[0063] <Method for producing a photoreactive polymer> The method for producing the photoreactive polymer of the present invention is not particularly limited. For example, the photoreactive polymer of the present invention can be obtained by preparing an azomethine derivative monomer having a polymerizable group and a predetermined structure and polymerizing it by a conventionally known method.

[0064] That is, according to one embodiment of the present invention, there is provided a method for producing a polymer of the present invention, which includes preparing an azomethine derivative monomer represented by any of the following general formulas (1-1') to (1-4') and polymerizing it:

[0065] [Chemical formula]

[0066] In the above general formulas (1-1') to (1-4'), J is a polymerizable group, G is a divalent group, Z 1 and Z 2 are CH or N, Z 1 ≠Z 2 and R 1 is an aromatic hydrocarbon group having substituents R 1 selected from the group consisting of an alkyl group, an alkoxy group, and a halogen atom at two ortho positions with respect to Z a respectively, R 2 is a substituted or unsubstituted aromatic heterocyclic group. Specific forms of the above G are the same as those described above. Also, specific forms of the aromatic hydrocarbon group, the aromatic heterocyclic group, and the substituent R a are the same as those described above. Examples of the polymerizable group include a (meth)acryloyl group, a vinyl group, or a group containing these.

[0067] (Specific Examples of Preparation Methods of Azomethine Derivatives Having Polymerizable Groups) The preparation of azomethine derivatives having polymerizable groups can be carried out by preparing an azomethine derivative represented by the general formula (1) and introducing a polymerizable group thereto.

[0068] For example, R 1 has a benzene ring having a predetermined substituent R a , Z 1 is NH, Z 2 is C, and R 2 has a pyrazole ring. When preparing an azomethine derivative, as the first step, an aniline derivative having a predetermined substituent R a is reacted with a pyrazolecarboxaldehyde derivative. At this time, if either the above aniline derivative or pyrazolecarboxaldehyde derivative has an OH group as a substituent, a polymerizable group can be easily introduced at the position of the OH group.

[0069] Also, for example, R 1 has a benzene ring having a predetermined substituent R a , Z 1 is C, Z 2 is NH, and R 2 has a pyrazole ring. When preparing an azomethine derivative, as the first step, a benzaldehyde derivative having a predetermined substituent R a is reacted with an aminopyrazole derivative. At this time, if either the above benzaldehyde derivative or aminopyrazole derivative has an OH group as a substituent, a polymerizable group can be easily introduced at the position of the OH group.

[0070] For example, as shown in the following formula, in a solvent such as methanol or ethanol, 2,6-dimethyl-4-hydroxybenzaldehyde and 4-amino-1-methylpyrazole are treated (heated to reflux for reaction), the reaction solution is filtered, the obtained powder is washed with cooled ethanol, and recrystallized with methanol / ethanol to obtain the target product.

[0071] [Chemistry]

[0072] Subsequently, as a second step, a polymerizable group is introduced into the intermediate A. The method for introducing the polymerizable group is not particularly limited. For example, when introducing -O-C 6 H 12 - as a linker to the intermediate A, as a halogenated alcohol compound, for example, Cl-C 6 H 12 -OH is allowed to act to obtain the following intermediate B.

[0073] The reaction conditions are not particularly limited. For example, in a solvent such as dimethylformamide (DMF), in the presence of potassium carbonate and potassium iodide, preferably within the range of 10°C or higher and 150°C or lower, more preferably within the range of 50°C or higher and 140°C or lower, and even more preferably within the range of 80°C or higher and 130°C or lower. It is preferable to carry out the reaction. Note that the addition order of potassium carbonate and potassium iodide is preferably that potassium carbonate is added first. Before adding potassium iodide after adding potassium carbonate, stirring is preferably carried out within the range of 0°C or higher and 100°C or lower, more preferably within the range of 0°C or higher and 60°C or lower, and even more preferably within the range of 0°C or higher and 40°C or lower.

[0074] [Chemistry]

[0075] Thereafter, as the third step, the intermediate B is reacted with a compound for forming a polymerizable group, for example, an acrylic acid halide or a methacrylic acid halide. As a result, the photoresponsive polymer will contain a structural unit derived from (meth)acrylic acid ester. At this time, the reaction conditions are not particularly limited. For example, it is preferable to carry out the reaction in a known organic solvent in the presence of tertiary amines such as triethylamine and triethanolamine. Preferably, while maintaining the mixed solution containing the above intermediate B, tertiary amines, and solvent at 0 to 10 °C, a compound for forming a polymerizable group such as an acrylic acid halide or a methacrylic acid halide is dropped into this mixed solution and mixed. Thereafter, the mixed solution is reacted at room temperature for about 5 to 10 hours, and an azomethine derivative having a polymerizable group can be obtained.

[0076]

Chemical formula

[0077] In addition, in the above first step, a desired azomethine derivative can be obtained by changing the raw materials used to other compounds.

[0078] Also, by changing the compounds added in the second step and the third step, groups having polymerizable groups with different structures can be introduced. A person skilled in the art can appropriately make the above changes and select appropriate reaction conditions to synthesize an azomethine derivative having a desired polymerizable group.

[0079] Also, in the above first step, a polymerizable group can be introduced into the intermediate A without performing the second step by appropriately selecting the raw materials used.

[0080] One embodiment of the present invention is a photoresponsive polymer containing a structural unit represented by the following general formula (1), which is fluidized by light irradiation and reversibly non-fluidized:

[0081]

Chemical formula

[0082] (In general formula (1), Z 1 and Z 2 are CH or N, and Z 1 ≠Z 2 ; R 1 is an aromatic hydrocarbon group having, for Z 1 substituents R a each selected from the group consisting of an alkyl group, an alkoxy group, and a halogen atom at two ortho positions, and R 2 is a substituted or unsubstituted aromatic heterocyclic group, and at least one of said R 1 and said R 2 is bonded to a group containing a structure derived from a polymerizable group.); However, it is a polymer excluding the following polymers (high molecular compounds) (1) to (4); (1) A polymer that contains a structural unit derived from an azomethine derivative having a polymerizable group and is reversibly fluidized and non-fluidized by light irradiation, represented by the following chemical formula (1):

[0083] [Chemical formula]

[0084] In the chemical formula (1), X is NR 10 , O or S, R 1 and R 2 are each independently a group having a polymerizable group, a hydrogen atom, a halogen atom, a cyano group, a nitro group, a hydroxy group, a carboxy group, an alkyl group having 1 to 16 carbon atoms, an alkoxy group having 1 to 16 carbon atoms, an acyl group having 2 to 16 carbon atoms, an alkoxycarbonyl group having 2 to 16 carbon atoms, or an acyloxy group having 2 to 16 carbon atoms, R 3 or R 4One of them is a group represented by Y, and the other is a group having a polymerizable group, a hydrogen atom, a halogen atom, a cyano group, a nitro group, a hydroxy group, a carboxy group, an alkyl group having 1 to 16 carbon atoms, an alkoxy group having 1 to 16 carbon atoms, an acyl group having 2 to 16 carbon atoms, an alkoxycarbonyl group having 2 to 16 carbon atoms, or an acyloxy group having 2 to 16 carbon atoms, R 10 is a group having a polymerizable group, a hydrogen atom, a halogen atom, a hydroxy group, an alkyl group having 1 to 16 carbon atoms, an alkoxy group having 1 to 16 carbon atoms, an acyl group having 2 to 16 carbon atoms, an alkoxycarbonyl group having 2 to 16 carbon atoms, or an acyloxy group having 2 to 16 carbon atoms, Z 1 Z 2 is N or CH, and Z 1 ≠Z 2 and R 5 ~R 7 are each independently a group having a polymerizable group, a hydrogen atom, a halogen atom, a cyano group, a nitro group, a hydroxy group, a carboxy group, an alkyl group having 1 to 16 carbon atoms, an alkoxy group having 1 to 16 carbon atoms, an acyl group having 2 to 16 carbon atoms, an alkoxycarbonyl group having 2 to 16 carbon atoms, or an acyloxy group having 2 to 16 carbon atoms, R 8 and R 9 are each independently a hydrogen atom, a halogen atom, a cyano group, a nitro group, a hydroxy group, a carboxy group, an alkyl group having 1 to 16 carbon atoms, an alkoxy group having 1 to 16 carbon atoms, an acyl group having 2 to 16 carbon atoms, an alkoxycarbonyl group having 2 to 16 carbon atoms, or an acyloxy group having 2 to 16 carbon atoms, At this time, at least one of those not selected as the group represented by Y among R 1 , R 2 , R 5 ~R 7 , R 10 , and R 3 or R 4 is a group having a polymerizable group, R 1 , R 2 , R 10 , and R 3 or R4 When at least one of those not selected as the group represented by Y among them is a group having a polymerizable group, R 1 , R 2 , R 10 , and R 3 or R 4 Among them, those other than the group having the polymerizable group and the group represented by Y are each independently selected from a hydrogen atom, a halogen atom, a cyano group, a nitro group, a hydroxy group, a carboxy group, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, provided that R 10 is selected from a hydrogen atom, a halogen atom, a hydroxy group, a carboxy group, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, R 5 ~R 7 When at least one of them is a group having a polymerizable group, among R 5 ~R 7 those other than the polymerizable group, R 8 and R 9 are each independently selected from a hydrogen atom, a halogen atom, a cyano group, a nitro group, a hydroxy group, a carboxy group, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, R 5 and R 9 are each independently selected from the group consisting of an alkyl group, an alkoxy group, and a halogen atom: (2) A polymer compound that is reversibly fluidized and non-fluidized by light irradiation, represented by the following general formula (1):

[0085] [Chemical formula]

[0086] In the above general formula (1), A is a polymer block containing a structural unit derived from an azomethine derivative having a polymerizable group represented by chemical formula (2), and B is a polymer block not containing the structure derived from the azomethine derivative represented by the chemical formula (2):

[0087] [Chemical formula]

[0088] In the above chemical formula (2), X is NR 10 , O or S, and R 1 and R 2 are each independently a group having a polymerizable group, a hydrogen atom, a halogen atom, a cyano group, a nitro group, a hydroxy group, a carboxy group, an alkyl group having 1 to 16 carbon atoms, an alkoxy group having 1 to 16 carbon atoms, an acyl group having 2 to 16 carbon atoms, an alkoxycarbonyl group having 2 to 16 carbon atoms, or an acyloxy group having 2 to 16 carbon atoms, R 3 or R 4 is a group represented by Y, and the other is a group having a polymerizable group, a hydrogen atom, a halogen atom, a cyano group, a nitro group, a hydroxy group, a carboxy group, an alkyl group having 1 to 16 carbon atoms, an alkoxy group having 1 to 16 carbon atoms, an acyl group having 2 to 16 carbon atoms, an alkoxycarbonyl group having 2 to 16 carbon atoms, or an acyloxy group having 2 to 16 carbon atoms, R 10 is a group having a polymerizable group, a hydrogen atom, a halogen atom, a hydroxy group, an alkyl group having 1 to 16 carbon atoms, an alkoxy group having 1 to 16 carbon atoms, an acyl group having 2 to 16 carbon atoms, an alkoxycarbonyl group having 2 to 16 carbon atoms, or an acyloxy group having 2 to 16 carbon atoms, Z 1 and Z 2 are N or CH, and Z 1 ≠Z 2 and R 5 ~R 7 are each independently a group having a polymerizable group, a hydrogen atom, a halogen atom, a cyano group, a nitro group, a hydroxy group, a carboxy group, an alkyl group having 1 to 16 carbon atoms, an alkoxy group having 1 to 16 carbon atoms, an acyl group having 2 to 16 carbon atoms, an alkoxycarbonyl group having 2 to 16 carbon atoms, or an acyloxy group having 2 to 16 carbon atoms, R 8 and R 9Each is independently a hydrogen atom, a halogen atom, a cyano group, a nitro group, a hydroxy group, a carboxy group, an alkyl group having 1 to 16 carbon atoms, an alkoxy group having 1 to 16 carbon atoms, an acyl group having 2 to 16 carbon atoms, an alkoxycarbonyl group having 2 to 16 carbon atoms, or an acyloxy group having 2 to 16 carbon atoms, At this time, R 1 、R 2 、R 5 ~R 7 、R 10 、and R 3 or R 4 Of those not selected as the group represented by Y, at least one is a group having a polymerizable group, R 1 、R 2 、R 10 、and R 3 or R 4 When at least one of those not selected as the group represented by Y has a polymerizable group, R 1 、R 2 、R 10 、and R 3 or R 4 Among those other than the group having the polymerizable group and the group represented by Y are each independently selected from a hydrogen atom, a halogen atom, a cyano group, a nitro group, a hydroxy group, a carboxy group, an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, provided that R 10 is selected from a hydrogen atom, a halogen atom, a hydroxy group, a carboxy group, an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, R 5 ~R 7 When at least one has a polymerizable group, R 5 ~R 7 Among those other than the polymerizable group, R 8 and R 9 are each independently selected from a hydrogen atom, a halogen atom, a cyano group, a nitro group, a hydroxy group, a carboxy group, an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, R 5 and R 9Each independently selected from the group consisting of an alkyl group, an alkoxy group, and a halogen atom: (3) A photoreactive polymer that contains a structural unit represented by the following general formula (1) and that fluidizes upon light irradiation and reversibly becomes non-fluidized,

[0089]

Chemical formula

[0090] In general formula (1), r 1 is a hydrogen atom or a methyl group, A is a group having an azomethine structure represented by the following general formula (2),

[0091]

Chemical formula

[0092] In general formula (2), Z 1 and Z 2 each independently is N or CH, and Z 1 ≠ Z 2 and, B 1 each independently is a substituted or unsubstituted divalent aromatic hydrocarbon group or a substituted or unsubstituted divalent aromatic heterocyclic group, B 2 each independently is a substituted or unsubstituted monovalent aromatic hydrocarbon group or a substituted or unsubstituted monovalent aromatic heterocyclic group, -B 1 -Z 1 = Z 2 -B 2 is represented by any one of the following Structures 2 to 5,

[0093]

Chemical formula

[0094] (In Structure 2, Z 1 and Z 2 are N or CH, and Z 1 ≠ Z2 and R 53 is the linking moiety with the oxygen atom (in the case of (2-a) or (2-c)) or r 2 (in the case of (2-b)), X is S, O, or NR 61 and R 61 is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or an alkoxycarbonyl group having 2 to 19 carbon atoms, R 62 ~R 64 are each independently a hydrogen atom, a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, a dialkylamino group having 2 to 10 carbon atoms, an acyl group having 2 to 19 carbon atoms, or an alkoxycarbonyl group having 2 to 19 carbon atoms (in one embodiment, R 62 ~R 64 are all hydrogen atoms), R 51 , R 55 are each independently selected from the group consisting of a halogen atom, an alkyl group, and an alkoxy group, R 52 , R 54 are each independently a hydrogen atom, a halogen atom, a cyano group, a nitro group, an amino group, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, an alkylamino group having 1 to 10 carbon atoms, a dialkylamino group having 2 to 10 carbon atoms, an acyl group having 2 to 19 carbon atoms, or an alkoxycarbonyl group having 2 to 19 carbon atoms.)

[0095] [Chemical formula]

[0096] (In Structure 3, Z 1 , Z 2 , X, R 51 ~R 55 are the same as in Structure 2 above, R 65 ~R 67is independently a hydrogen atom, a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, a dialkylamino group having 2 to 10 carbon atoms, an acyl group having 2 to 19 carbon atoms, or an alkoxycarbonyl group having 2 to 19 carbon atoms.)

[0097]

Chemical formula

[0098] (In Structure 4, Z 1 , Z 2 , R 51 ~R 55 are the same as in Structure 2 above, R 68 ~R 70 are independently a hydrogen atom, a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, a dialkylamino group having 2 to 10 carbon atoms, an acyl group having 2 to 19 carbon atoms, or an alkoxycarbonyl group having 2 to 19 carbon atoms. In one embodiment, R 68 ~R 70 are all hydrogen atoms.)

[0099]

Chemical formula

[0100] (In Structure 5, Z 1 , Z 2 , R 51 ~R 55 are the same as in Structure 2 above, R 71 ~R 73 are independently a hydrogen atom, a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, a dialkylamino group having 2 to 10 carbon atoms, an acyl group having 2 to 19 carbon atoms, or an alkoxycarbonyl group having 2 to 19 carbon atoms.) r 2 are independently an alkylene group having 1 to 18 carbon atoms, A photosensitive polymer characterized in that the activation energy Ea represented by the following formula (1), in which a hydrogen atom is bonded in place of the oxygen atom bonded to A in the general formula (1), is 60 kJ / mol or more: Formula (1): Ea (kJ / mol) = (total energy of TS (kJ / mol)) - (total energy of cis isomer (kJ / mol)) In the above formula (1), TS refers to the transition state represented by the general formula (3), and the cis isomer refers to the isomer represented by the general formula (4);

[0101]

Chemical formula

[0102] (In calculating the activation energy Ea represented by the following formula (1), as the molecular structure of the cis isomer, the most stable molecular structure of the isomer represented by the above general formula (4) is calculated, and this total energy is taken as the total energy of the cis isomer. As the molecular structure of TS, for the transition state represented by the general formula (3), the saddle point of the corresponding molecular structure is calculated, and the total energy obtained at this time is taken as the total energy of TS. At this time, for calculating the molecular structure of the cis isomer, the total energy of the cis isomer, the molecular structure of TS, and the total energy of TS, Gaussian16 software manufactured by Gaussian can be used, and the density functional method (B3LYP / 6-31G(d)) can be used as the calculation method for calculation.): (4) A photosensitive polymer containing a structural unit represented by the following general formula (2), which is fluidized by light irradiation and reversibly non-fluidized:

[0103]

Chemical formula

[0104] In the above general formula (2), r 1 is a hydrogen atom, A is represented by the following formula.

[0105]

Chemical formula

[0106] (Other structural units) In one embodiment of the present invention, the photoresponsive polymer may contain structural units other than the structural units (other structural units) derived from the azomethine derivative represented by the general formula (1). When it is a copolymer containing other structural units, the arrangement form of the repeating units of the copolymer is not particularly limited, and it may be any of a random copolymer, a block copolymer, and an alternating copolymer.

[0107] As the above other structural units, those not containing the structural units derived from the azomethine derivative represented by the general formula (1) are preferable, and it is more preferable that they are structural units constituting a thermoplastic resin that softens by heating.

[0108] As the above other structural units, those having a vinyl polymerizable group are preferable because the synthesis of the copolymer is easy. That is, in one embodiment of the present invention, the photoresponsive polymer further contains other structural units derived from a monomer having a vinyl polymerizable group. Specifically, for example, styrene derivatives, (meth)acrylic acid derivatives, olefin derivatives, vinyl ester derivatives, vinyl ether derivatives, vinyl ketone derivatives, etc. are used, and it is preferable that they are structural units derived from styrene derivatives, (meth)acrylic acid derivatives, or olefin derivatives. That is, in one embodiment of the present invention, the monomer having a vinyl polymerizable group is at least one selected from the group consisting of styrene derivatives, (meth)acrylic acid derivatives, and olefin derivatives. By being such an embodiment, the intended effects of the present invention can be efficiently achieved.

[0109] Examples of styrene derivatives include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-t-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, and the like.

[0110] Examples of (meth)acrylic acid derivatives include (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, stearyl (meth)acrylate, dodecyl (meth)acrylate, phenyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, and the like.

[0111] Examples of olefin derivatives include ethylene, propylene, n-butylene, isobutylene, n-pentene, 3-methyl-1-pentene, and the like. The olefin derivatives may be linear or branched, and the number of carbon atoms in the carbon chain is not particularly limited.

[0112] Examples of vinyl ester derivatives include vinyl propionate, vinyl acetate, vinyl benzoate, and the like. Examples of vinyl ether derivatives include vinyl methyl ether, vinyl ethyl ether, and the like. Examples of vinyl ketone derivatives include vinyl methyl ketone, vinyl ethyl ketone, vinyl hexyl ketone, and the like.

[0113] The content of the other structural unit in the polymer is not particularly limited and can be appropriately selected. However, it is preferably 70% by mass or less, more preferably 40% by mass or less, based on 100% by mass of the total amount of all the structural units constituting the polymer. In one embodiment of the present invention, the content of the other structural unit in the polymer can be 5% by mass or more and 15% by mass or more.

[0114] In one embodiment of the present invention, the number average molecular weight Mn of the photoreactive polymer is not particularly limited, but is preferably 3000 or more, 3500 or more, 4000 or more, 5000 or more, or 10000 or more. In one embodiment of the present invention, the number average molecular weight Mn of the photoreactive polymer is not particularly limited, but is preferably 100000 or less, 70000 or less, 50000 or less, 40000 or less, or 30000 or less. If the number average molecular weight of the polymer is 3000 or more, it is preferably tough, and when used as a toner, a toner image excellent in fixability can be more easily obtained. Also, if the number average molecular weight is 100000 or less, the efficiency of isomerization and softening melting is high, which is preferable.

[0115] The number average molecular weight of the polymer of the present invention can be measured by gel permeation chromatography (GPC). Specifically, it can be measured by the method described in the examples below.

[0116] (Method for preparing polymer) The method for synthesizing the polymer of the present invention is not particularly limited, and a method of polymerizing an azomethine derivative represented by the general formula (1) having a polymerizable group as a monomer using a known polymerization initiator such as anionic polymerization, cationic polymerization, living radical polymerization, etc. can be used. A known chain transfer agent may be used as necessary.

[0117] As the polymerization initiator, for example, the azo-based or diazo-based polymerization initiators or peroxide-based polymerization initiators shown below are used.

[0118] Examples of azo-based or diazo-based polymerization initiators include azobisisobutyronitrile (AIBN) such as 2,2'-azobis-(2,4-dimethylvaleronitrile) and 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, and the like.

[0119] Examples of peroxide-based polymerization initiators include benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxydicarbonate, cumene hydroperoxide, t-butyl hydroperoxide, di-t-butyl peroxide, dicumyl peroxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, 2,2-bis-(4,4-t-butylperoxycyclohexyl)propane, tris-(t-butylperoxy)triazine, and the like.

[0120] Examples of the chain transfer agent include benzyl dithiobenzoate, 1-phenylethyl dithiobenzoate, 2-phenylprop-2-yl dithiobenzoate, 1-acetoxylethyl dithiobenzoate, hexakis(thiobenzoylthiomethyl)benzene, 1,4-bis(thiobenzoylthiomethyl)benzene, 1,2,4,5-tetrakis(thiobenzoylthiomethyl)benzene, 1,4-bis-(2-(thiobenzoylthio)prop-2-yl)benzene, 1-(4-methoxyphenyl)ethyl dithiobenzoate, benzyl dithioacetate; ethoxycarbonylmethyl dithioacetate, 2-(ethoxycarbonyl)prop-2-yl dithiobenzoate, 2-cyanoprop-2-yl dithiobenzoate, t-butyl dithiobenzoate, 2,4,4-trimethylpent-2-yl dithiobenzoate, 2-(4-chlorophenyl)prop-2-yl dithiobenzoate, 3- and 4-vinylbenzyl dithiobenzoate, S-benzyl diethoxyphosphinyldithioformate, t-butyl trithioperbenzoate, 2-phenylprop-2-yl 4-chlorodithiobenzoate, 2-phenylprop-2-yl 1-dithionaphthalate, 4-cyanopentanoic acid dithiobenzoate, dibenzyl tetrathioterephthalate, dibenzyl trithiocarbonate, carboxymethyl dithiobenzoate, and the like.

[0121] The polymerization temperature varies depending on the types of monomers and polymerization initiators used, but is preferably 50 to 100°C, more preferably 55 to 90°C. Also, the polymerization time varies depending on the types of monomers and polymerization initiators used, but is preferably, for example, 2 to 60 hours.

[0122] In addition, the preparation method of the copolymer containing structural units other than the structural units containing the group having an azomethine structure represented by the general formula (1) (other structural units) is not particularly limited.

[0123] For example, when preparing a random copolymer, in addition to the monomer for forming the structural unit represented by the general formula (1) as a raw material monomer, the monomer for forming the other structural units is mixed with a chain transfer agent, a polymerization initiator, etc., and a desired copolymer can be obtained by performing a polymerization reaction. The specific form of the monomer for forming the other structural units is as described above.

[0124] In one embodiment of the present invention, the photoreactive polymer is represented by the following general formula (3):

[0125]

Chemical formula

[0126] wherein α is independently a polymer block containing the structural unit represented by the general formula (2), β is independently a polymer block containing a structural unit other than the structural unit represented by the general formula (2). By virtue of such an embodiment, the azomethine derivative can easily form domains in the polymer and efficiently induce softening and melting, and a polymer having high toughness can be obtained by having a structural unit other than the structural unit represented by the general formula (2).

[0127] The polymer of the present invention polymerizes, and the azomethine structure part absorbs light, and the heat energy released in the photoexcitation and deactivation processes is transmitted to the repeating units (structural units) to be bonded (photo-thermal conversion), so that melting or softening can proceed. Further, by forming a block copolymer, the azomethine structure part is likely to form domains in the polymer, and it is considered that softening and melting are efficiently induced. Therefore, the effects of the present invention can be obtained more remarkably.

[0128] The specific form of the structural unit represented by the general formula (2) constituting the polymer block α is as described above.

[0129] The structural unit constituting the polymer block β does not include the azomethine structure (R 1 -Z 1 =Z 2 -R 2 ) in the general formula (1). Specifically, the form described as a structural unit other than the structural unit containing the above azomethine structure can be preferably used. In particular, from the viewpoint of applying to the synthesis of block copolymers by living radical polymerization methods such as ATRP method, ARGET-ATRP method or RAFT method, it is preferably one having a vinyl polymerizable group. Specifically, for example, styrene derivatives, (meth)acrylic acid derivatives, olefin derivatives, vinyl ester derivatives, vinyl ether derivatives, vinyl ketone derivatives, etc. are used, and styrene derivatives, (meth)acrylic acid derivatives, or olefin derivatives are preferred. That is, in one embodiment of the present invention, the photoresponsive polymer is a polymer block in which the β contains at least one structural unit selected from the group consisting of styrene derivatives, (meth)acrylic acid derivatives, and olefin derivatives. Such an embodiment has a technical effect that a polymer with high toughness can be obtained.

[0130] The number average molecular weight (total number average molecular weight) of the polymer block α contained in the polymer represented by the general formula (3) is not particularly limited, but is preferably 1000 or more, more preferably 1000 to 100000, still more preferably 1000 to 70000, even more preferably 1000 to 50000, and particularly preferably 3000 to 50000. If the total number average molecular weight of the polymer block α is 1000 or more, a toner image with excellent fixing property is more easily obtained when used as a toner, which is preferable. Also, if the total number average molecular weight of the polymer block α is 100000 or less, the efficiency of softening and melting becomes high, which is preferable. Here, the total number average molecular weight of the polymer block α refers to the number average molecular weight of the polymer block α when the polymer represented by the general formula (3) contains a single polymer block α, and in the case of containing a plurality of polymer blocks α, it means the sum of the number average molecular weights of each polymer block α.

[0131] The number average molecular weight (total number average molecular weight) of the polymer block β contained in the polymer represented by the general formula (3) is not particularly limited, but is preferably 1000 or more, more preferably 1100 to 100000, still more preferably 1500 to 70000, even more preferably 2000 to 50000, and particularly preferably 3000 to 40000. If the total number average molecular weight of the polymer block β is 1000 or more, a toner image excellent in fixability is more easily obtained when used as a toner, which is preferable. Also, if the total number average molecular weight of the polymer block β is 100000 or less, the efficiency of softening and melting is high, which is preferable. Here, the total number average molecular weight of the polymer block β refers to the number average molecular weight of the polymer block β when the polymer represented by the general formula (3) contains a single polymer block β, and in the case of containing a plurality of polymer blocks β, it means the sum of the number average molecular weights of each polymer block β.

[0132] Also, the total number average molecular weight Mn of the polymer represented by the general formula (3) is preferably 3000 or more, more preferably 3200 to 100000, still more preferably 3300 to 70000, even more preferably 3400 to 50000, and particularly preferably 3450 to 50000. If the total number average molecular weight of the polymer represented by the general formula (3) is 3000 or more, a toner image excellent in fixability is more easily obtained when used as a toner, which is preferable. Also, if the total number average molecular weight is 100000 or less, the efficiency of softening and melting is high, which is preferable.

[0133] That is, in one embodiment of the present invention, in the photoreactive polymer, the number average molecular weight of α is 1000 or more, the number average molecular weight of β is 1000 or more, and the total number average molecular weight is 3000 or more.

[0134] In the polymer represented by the general formula (3), the ratio of the total number-average molecular weight of the polymer block α to the total number-average molecular weight of the polymer block β is not particularly limited. However, from the viewpoints of ease of softening and melting and image strength, the ratio of the total number-average molecular weight of the polymer block α to the total number-average molecular weight of the polymer block β is preferably from 1:20 to 20:1, more preferably from 1:15 to 15:1.

[0135] The total number-average molecular weight of the polymer represented by the general formula (3), and the total number-average molecular weights of the polymer blocks α and β can be measured by gel permeation chromatography (GPC). Specifically, it can be measured by the method described in the examples below.

[0136] The method for synthesizing the block copolymer represented by the general formula (3) is not particularly limited, and known methods such as anionic polymerization, cationic polymerization, and living radical polymerization can be used. Among them, living radical polymerization methods such as atom transfer radical polymerization (ATRP method), ARGET-ATRP method, or RAFT method can be preferably used as a simple synthesis method.

[0137] Taking the ATRP method as an example, it can be carried out by a method such as using a compound containing a monofunctional, difunctional, trifunctional, or tetrafunctional halogen element as a starting material and polymerizing a monomer that becomes a structural unit of the polymer block α or β under a catalyst.

[0138] In the stage of polymerizing the monomer, for example, a monomer that becomes a structural unit of either the polymer block α or β (the block that becomes the core part of the block copolymer) is polymerized in the presence of an initiator, a catalyst, and a ligand to produce a macroinitiator.

[0139] Examples of the initiator include, but are not limited to, butyl 2-bromoisobutyrate, ethyl 2-bromoisobutyrate, ethylene bis(2-bromoisobutyrate), 1,1,1-tris(2-bromoisobutyryloxymethyl)ethane, pentaerythritol tetrakis(2-bromoisobutyrate), α,α'-dibromo-p-xylene, ethyl bromoacetate, 2-bromoisobutyryl bromide, or mixtures thereof.

[0140] Examples of the catalyst include copper(I) catalysts and iron(II) catalysts, such as Cu(I)Cl, Cu(I)Br, Fe(II)Cl, Fe(II)Br, or mixtures thereof.

[0141] Known ligands can be used, and one or more selected from the group consisting of 2,2'-bipyridyl, 4,4'-dimethyl-2,2'-bipyridyl, 4,4'-di-tert-butyl-2,2'-bipyridyl, 1,1,4,7,10,10-hexamethyltriethylenetetramine, N,N,N',N",N"-pentamethyldiethylenetriamine, cyclam(1,4,8,11-tetraazacyclotetradecane), 1,4,8,11-tetramethylcyclam(1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane), tris[2-(dimethylamino)ethyl]amine, etc. are preferred.

[0142] The amounts of the above catalyst and ligand used are not particularly limited and can be appropriately determined with reference to conventionally known knowledge.

[0143] Next, the macroinitiator obtained by the above polymerization is isolated and used as an initiator. In the presence of a catalyst and a ligand again, among the monomers that will form the structural units of the polymer block α or β, the monomer that has not been used in the synthesis of the macroinitiator is polymerized. Alternatively, when almost all of the monomers have been consumed in the synthesis of the macroinitiator, without isolating the macroinitiator, the monomer that has not been used in the synthesis of the macroinitiator can be added as it is and the polymerization can be continued. The target block copolymer can be obtained by these operations.

[0144] Each of the above reactions is preferably carried out in an inert atmosphere such as nitrogen or noble gases such as argon. Each of the above reactions can be carried out, for example, at a temperature of 25 to 160 °C, preferably 35 to 130 °C. Also, each of the above reactions may be carried out without using a solvent, or may be carried out in a solvent such as an organic solvent like anisole.

[0145] In addition, in the reaction of polymerizing a monomer that will form the structural unit of either the polymer block α or β to obtain a macroinitiator, and the reaction of reacting the macroinitiator with a monomer that will form the structural unit of the other polymer block to obtain a block copolymer, the types and amounts of the catalysts and ligands used, and conditions such as the temperature during the reaction may be the same or different.

[0146] <Fluidization and Reversible Non-fluidization by Light Irradiation> When the polymer of the present invention is fluidized by light irradiation, the wavelength of the irradiation light is preferably in the range of 280 nm or more and 480 nm or less, more preferably in the range of 300 nm or more and 420 nm or less, and even more preferably in the range of 330 nm or more and 420 nm or less. Within the above range, the crystal is likely to collapse (good photo-melting property), and the fixing property is improved. Also, when fluidizing, in addition to light irradiation, heat or pressure may be applied to promote fluidization. By irradiating the irradiation light with the above wavelength, even when heat or pressure is applied, fluidization can be achieved with less heat or pressure. Therefore, by introducing the polymer of the present invention into the toner, fixing at the above wavelength becomes possible, and a toner excellent in fixing property, image stability, and high color reproducibility can be obtained.

[0147] Note that a part of visible light is included in the above wavelength range. Therefore, the polymer of the present invention does not fluidize only by receiving light from sunlight (natural light) or illumination such as a fluorescent lamp, and it is desirable to fluidize under low-cost conditions with the irradiation amount and irradiation time suppressed as much as possible. From such a viewpoint, as the irradiation conditions of the irradiation light when the above polymer fluidizes, the irradiation amount is preferably 0.1 J / cm 2 to 200 J / cm 2 within the following range, more preferably 0.1 J / cm 2 to 100 J / cm 2 within the following range, still more preferably 0.1 J / cm 2 to 50 J / cm 2 within the following range.

[0148] When fluidizing the polymer, the polymer may be heated together with light irradiation. Thereby, it can be fluidized with a lower irradiation amount. The heating temperature at this time is, for example, within the range of 20°C or higher and 200°C or lower, preferably within the range of 20°C or higher and 150°C or lower.

[0149] On the other hand, the condition for non-fluidizing (re-solidifying) the polymer of the present invention is preferably to leave it at room temperature (in the range of 25 ± 15°C) (in a natural environment). At this time, it is good to place it in a dark place, but it may be exposed to visible light such as natural light or a fluorescent lamp. It is more preferable to apply heat during the process of non-fluidizing. Also, light may be applied.

[0150] When heating the polymer to non-fluidize it, the heating temperature is preferably within the range of 0°C or higher and 200°C or lower, more preferably within the range of 20°C or higher and 150°C or lower.

[0151] [Composition of toner] One embodiment of the present invention is a toner containing the polymer of the present invention. That is, the present invention provides a toner containing the photo-responsive polymer as a binder resin. By introducing the polymer of the present invention into the toner, a toner that can be fixed by light irradiation, has excellent fixing properties and image stability, and high color reproducibility can be obtained. Note that the toner refers to an aggregate of toner base particles or toner particles. The toner particles are preferably those obtained by adding an external additive to the toner base particles, but the toner base particles can also be used as the toner particles as they are. In the present invention, when there is no particular need to distinguish between the toner base particles, the toner particles, and the toner, they are simply referred to as "toner".

[0152] The content of the polymer in the toner depends on the azomethine structure (R 1 -Z 1 =Z 2 -R 2 ) in the general formula (1) and the types of other structural units. From the viewpoints of efficient fluidization and image strength, for example, it is in the range of 5 to 95% by mass with respect to the total amount of the binder resin, colorant, release agent, and the polymer of the present invention that constitute the toner.

[0153] (Other binder resins) The toner of the present invention may further contain other binder resins. By being such an embodiment, the viscosity during fluidization can be adjusted, and the image strength can be increased. The binder resin is a resin having no structure derived from other azomethine derivatives, that is, a resin that does not contain the azomethine structure (R 1 -Z 1 =Z 2 -R 2 ), and resins generally used as binder resins constituting toners can be used without limitation. As the binder resin, for example, styrene resin, acrylic resin, styrene-acrylic resin, polyester resin, silicone resin, olefin resin, amide resin, and epoxy resin can be used. These binder resins can be used alone or in combination of two or more.

[0154] Among these, from the viewpoint of becoming low-viscosity when melted and having high sharp meltability, the binder resin preferably contains at least one selected from the group consisting of styrene resins, acrylic resins, styrene-acrylic resins, and polyester resins, and more preferably contains at least one selected from the group consisting of styrene-acrylic resins and polyester resins. By being such an embodiment, the image intensity can be enhanced.

[0155] (Styrene-acrylic resin) The styrene-acrylic resin referred to in the present invention is a polymer containing at least a structural unit derived from a styrene monomer and a structural unit derived from a (meth)acrylic acid ester monomer. Here, the styrene monomer is CH 2 =CH-C 6 H 5 In addition to styrene represented by the structural formula of, those having a structure with known side chains or functional groups in the styrene structure are also included.

[0156] Examples of the styrene monomer include the same ones as the styrene monomers that can constitute the aforementioned polymer.

[0157] Further, the (meth)acrylic acid ester monomer has a functional group having an ester bond in the side chain. Specifically, in addition to the acrylic acid ester monomer represented by CH 2 =CHCOOR (R is an alkyl group), vinyl ester compounds such as methacrylic acid ester monomers represented by CH 2 =C(CH 3 )COOR (R is an alkyl group) are included. Note that (meth)acrylic acid in the (meth)acrylic acid ester monomer means acrylic acid and methacrylic acid.

[0158] Examples of the (meth)acrylic acid ester monomer include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, stearyl (meth)acrylate, dodecyl (meth)acrylate, phenyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, and the like.

[0159] The styrene monomer and the (meth)acrylic acid ester monomer can be used alone or in combination of two or more.

[0160] The contents of the structural unit derived from the styrene monomer and the structural unit derived from the (meth)acrylic acid ester monomer in the styrene acrylic resin are not particularly limited and can be appropriately adjusted from the viewpoint of controlling the softening point and glass transition temperature of the binder resin. Specifically, the content of the structural unit derived from the styrene monomer is preferably 40 to 95% by mass, more preferably 50 to 90% by mass, based on all the structural units constituting the styrene acrylic resin. Further, the content of the structural unit derived from the (meth)acrylic acid ester monomer is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, based on all the structural units.

[0161] The content ratio of the styrene acrylic resin is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, based on all the resins.

[0162] The styrene acrylic resin may further contain a structural unit derived from another monomer other than the styrene monomer and the (meth)acrylic acid ester monomer, if necessary. Examples of the other monomer include vinyl monomers. Hereinafter, vinyl monomers that can be used in combination when forming the styrene acrylic copolymer according to the present invention are exemplified, but the vinyl monomers that can be used in combination are not limited to those shown below.

[0163] (1) Olefins Ethylene, propylene, isobutylene, etc. (2) Vinyl esters Vinyl propionate, vinyl acetate, vinyl benzoate, etc. (3) Vinyl ethers Vinyl methyl ether, vinyl ethyl ether, etc. (4) Vinyl ketones Vinyl methyl ketone, vinyl ethyl ketone, vinyl hexyl ketone, etc. (5) N-vinyl compounds N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone, etc. (6) Others Vinyl compounds such as vinyl naphthalene and vinyl pyridine, acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide.

[0164] Also, it is possible to produce a resin having a crosslinked structure by using a polyfunctional vinyl monomer. Furthermore, it is also possible to use a vinyl monomer having an ionic dissociating group in the side chain. Specific examples of the ionic dissociating group include, for example, a carboxyl group, a sulfonic acid group, a phosphoric acid group, etc. Specific examples of the vinyl monomer having these ionic dissociating groups are shown below.

[0165] Specific examples of the vinyl monomer having a carboxyl group include, for example, acrylic acid, methacrylic acid, maleic acid, itaconic acid, cinnamic acid, fumaric acid, maleic acid monoalkyl ester, itaconic acid monoalkyl ester, etc.

[0166] When forming the styrene acrylic resin used in the present invention, the contents of the styrene monomer and the (meth)acrylic acid ester monomer are not particularly limited and can be appropriately adjusted from the viewpoint of controlling the softening point temperature and glass transition temperature of the binder resin. Specifically, the content of the styrene monomer is preferably 40 to 95% by mass, more preferably 50 to 90% by mass, based on the total monomers constituting the styrene acrylic resin. Also, the content of the (meth)acrylic acid ester monomer is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, based on the total monomers constituting the styrene acrylic resin.

[0167] The method for forming the styrene acrylic resin is not particularly limited, and examples include a method of polymerizing monomers using a known oil-soluble or water-soluble polymerization initiator. If necessary, a known chain transfer agent such as n-octyl mercaptan may be used. As the oil-soluble polymerization initiator, for example, the following azo-based or diazo-based polymerization initiators and peroxide-based polymerization initiators are used.

[0168] Examples of the azo-based or diazo-based polymerization initiator include 2,2'-azobis-(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, and azobisisobutyronitrile.

[0169] Examples of the peroxide-based polymerization initiator include benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxydicarbonate, cumene hydroperoxide, t-butyl hydroperoxide, di-t-butyl peroxide, dicumyl peroxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, 2,2-bis-(4,4-t-butylperoxycyclohexyl)propane, and tris-(t-butylperoxy)triazine.

[0170] When forming styrene acrylic resin particles by the emulsion polymerization method, a water-soluble radical polymerization initiator can be used. Examples of water-soluble radical polymerization initiators include persulfates such as potassium persulfate and ammonium persulfate, azobisaminodipropanoic acid salts, azobiscyanovaleric acid and its salts, hydrogen peroxide, and the like.

[0171] The polymerization temperature varies depending on the types of monomers and polymerization initiators used, but is preferably 50 to 100 °C, more preferably 55 to 90 °C. Also, the polymerization time varies depending on the types of monomers and polymerization initiators used, but is preferably, for example, 2 to 12 hours.

[0172] The styrene acrylic resin particles formed by the emulsion polymerization method can also have a two-layer or more structure composed of resins with different compositions. As a manufacturing method in this case, a multi-stage polymerization method can be adopted in which a polymerization initiator and a polymerizable monomer are added to a dispersion of resin particles prepared by an emulsion polymerization treatment (first-stage polymerization) according to a conventional method, and this system is subjected to a polymerization treatment (second-stage and third-stage polymerization).

[0173] (Polyester resin) The polyester resin is a polyester resin obtained by a polycondensation reaction of a dicarboxylic acid or higher (polyvalent carboxylic acid component) and a diol or higher (polyvalent alcohol component). The polyester resin may be amorphous or crystalline.

[0174] The valences of the polyvalent carboxylic acid component and the polyvalent alcohol component are preferably 2 to 3, more preferably 2 each. That is, the polyvalent carboxylic acid component preferably contains a dicarboxylic acid component, and the polyvalent alcohol component preferably contains a diol component.

[0175] Examples of the dicarboxylic acid component include saturated aliphatic dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid (dodecanedioic acid), 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid; unsaturated aliphatic dicarboxylic acids such as methylene succinic acid, fumaric acid, maleic acid, 3-hexenedioic acid, 3-octenedioic acid, dodecenyl succinic acid; unsaturated aromatic dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, t-butylisophthalic acid, tetrachlorophthalic acid, chlorophthalic acid, nitrophthalic acid, p-phenylenediacetic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, anthracenedicarboxylic acid; and the like. Further, lower alkyl esters and acid anhydrides thereof can also be used. The dicarboxylic acid component may be used alone or in admixture of two or more.

[0176] In addition, polyvalent carboxylic acids having a valence of 3 or more such as trimellitic acid and pyromellitic acid, and anhydrides thereof, or alkyl esters having 1 to 3 carbon atoms can also be used.

[0177] Examples of the diol component include saturated aliphatic diols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, 1,20-eicosanediol, neopentyl glycol; unsaturated aliphatic diols such as 2-butene-1,4-diol, 3-butene-1,4-diol, 2-butyne-1,4-diol, 3-butyne-1,4-diol, 9-octadecene-7,12-diol; bisphenols such as bisphenol A and bisphenol F, and alkylene oxide adducts of bisphenols such as ethylene oxide adducts and propylene oxide adducts of these, i.e., aromatic diols. Also, derivatives of these can be used. The diol component may be used alone or as a mixture of two or more.

[0178] The method for producing the polyester resin is not particularly limited, and it can be produced by polycondensing (esterifying) the above polyvalent carboxylic acid component and polyhydric alcohol component using a known esterification catalyst.

[0179] Examples of the catalyst that can be used in the production of the polyester resin include alkali metal compounds such as sodium and lithium; compounds containing Group 2 elements such as magnesium and calcium; compounds of metals such as aluminum, zinc, manganese, antimony, titanium, tin, zirconium, and germanium; phosphorous acid compounds; phosphoric acid compounds; and amine compounds. Specifically, examples of the tin compound include dibutyltin oxide, tin octylate, dioctyltin, and salts thereof. Examples of the titanium compound include tetra-n-butyl titanate (Ti(O-n-Bu) 4) Titanium alkoxides such as tetraisopropyl titanate, tetramethyl titanate, and tetrastearyl titanate; titanium acylates such as polyhydroxy titanium stearate; titanium chelates such as titanium tetraacetylacetonate, titanium lactate, and titanium triethanolamine, etc. can be mentioned. Examples of germanium compounds include germanium dioxide. Further, examples of aluminum compounds include polyaluminum hydroxide, aluminum alkoxide, tributylaluminate, etc. These may be used alone or in combination of two or more.

[0180] The polymerization temperature is not particularly limited, but it is preferably 70 to 250 °C. Also, the polymerization time is not particularly limited, but it is preferably 0.5 to 10 hours. During polymerization, the inside of the reaction system may be depressurized as necessary.

[0181] The content ratio of the polyester resin is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, based on the total resin.

[0182] From the viewpoints of fixability and heat-resistant storage stability, etc., the glass transition temperature (Tg) of the toner is preferably 25 to 100 °C, more preferably 30 to 80 °C. The glass transition temperature (Tg) of the toner can be adjusted by the molecular weight of the polymer, and when it contains structural units other than the structural unit of the general formula (1), by the type and content thereof. When the toner contains a binder resin, it can be further adjusted by the content ratio of the above polymer and the binder resin, the type of the binder resin, and the molecular weight, etc.

[0183] Note that the toner of the present invention may be particles having a single-layer structure or particles having a core-shell structure. The types of binder resins used for the core particles and the shell part of the core-shell structure are not particularly limited.

[0184] <Colorant> The toner of the present invention may further contain a colorant. Since the polymer of the present invention has no significant coloring, a toner with high color reproducibility of the colorant can be obtained. As the colorant, generally known dyes and pigments can be used.

[0185] Examples of the colorant for obtaining a black toner include carbon black, magnetic materials, iron-titanium composite oxide black, etc. Examples of carbon black include channel black, furnace black, acetylene black, thermal black, and lamp black. Examples of the magnetic material include ferrite, magnetite, etc.

[0186] Examples of the colorant for obtaining a yellow toner include dyes such as C.I. Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162; and pigments such as C.I. Pigment Yellow 14, 17, 74, 93, 94, 138, 155, 180, 185.

[0187] Examples of the colorant for obtaining a magenta toner include dyes such as C.I. Solvent Red 1, 49, 52, 58, 63, 111, 122; and pigments such as C.I. Pigment Red 5, 48:1, 53:1, 57:1, 122, 139, 144, 149, 166, 177, 178, 222.

[0188] Examples of the colorant for obtaining a cyan toner include dyes such as C.I. Solvent Blue 25, 36, 60, 70, 93, 95; and pigments such as C.I. Pigment Blue 1, 7, 15, 15:3, 60, 62, 66, 76.

[0189] For each color of toner, the colorants for obtaining the toners of each color can be used alone or in combination of two or more.

[0190] The content of the colorant is preferably 0.5 to 20% by mass, more preferably 2 to 10% by mass, in the toner particles (toner base particles) before the addition of the external additive.

[0191] <Release agent> The toner according to the present invention may further contain a release agent. By introducing the release agent into the toner, when heat fixing is performed together with light irradiation, a toner having more excellent fixing properties and high color reproducibility can be obtained.

[0192] The release agent to be used is not particularly limited, and various known waxes can be used. Examples of the wax include polyolefins such as low molecular weight polypropylene, polyethylene, or oxidized low molecular weight polypropylene, polyethylene, paraffin wax, synthetic ester wax, and the like. Among them, from the viewpoint of improving the storage stability of the toner, it is preferable to use paraffin wax.

[0193] The content of the release agent is preferably 1 to 30% by mass, more preferably 3 to 15% by mass, in the toner base particles.

[0194] <Charge control agent> The toner according to the present invention may contain a charge control agent. The charge control agent to be used is a substance capable of imparting positive or negative charge by triboelectrification, and is not particularly limited as long as it is colorless, and various known positive charge control agents and negative charge control agents can be used.

[0195] The content of the charge control agent is preferably 0.01 to 30% by mass, more preferably 0.1 to 10% by mass, in the toner base particles.

[0196] <External additive> In order to improve the fluidity, chargeability, cleaning property, etc. of the toner, external additives such as a fluidizing agent and a cleaning aid, which are so-called post-treatment agents, may be added to the toner base particles to constitute the toner according to the present invention.

[0197] Examples of the external additive include inorganic oxide particles such as silica particles, alumina particles, and titanium oxide particles; inorganic stearic acid compound particles such as aluminum stearate particles and zinc stearate particles; and inorganic titanate compound particles such as strontium titanate particles and zinc titanate particles. These inorganic particles may be hydrophobically treated as necessary. These can be used alone or in combination of two or more.

[0198] Among these, as the external additive, for example, sol-gel silica particles, silica particles with a hydrophobically treated surface (hydrophobic silica particles), or titanium oxide particles (hydrophobic titanium oxide particles) are preferable.

[0199] The number average primary particle size of the external additive is preferably in the range of 1 to 200 nm, more preferably 10 to 180 nm. When using a combination of two or more external additives, it is particularly preferable that at least one of the external additives is 30 nm or more and 180 nm or less.

[0200] The addition amount of these external additives is preferably 0.05 to 5% by mass in the toner, more preferably 0.1 to 3% by mass.

[0201] In one embodiment of the present invention, the addition amount of these external additives is preferably 0.05 to 5% by mass, more preferably 0.1 to 3% by mass, based on the toner base particles.

[0202] <Average particle size of toner> The average particle size of the toner (and the average particle size of the toner base particles) is preferably 4 to 20 μm in terms of the volume-based median diameter (D50), more preferably 5 to 15 μm. When the volume-based median diameter (D50) is within the above range, the transfer efficiency is increased, the halftone image quality is improved, and the image quality of fine lines and dots is improved.

[0203] The volume-based median diameter (D50) can be measured and calculated using a measuring device connected to a computer system (manufactured by Beckman Coulter, Inc.) equipped with data processing software "Software V3.51" and the "Coulter Counter 3" (manufactured by Beckman Coulter, Inc.).

[0204] Specifically, 0.02 g of a measurement sample (toner or toner mother particles) is added to 20 mL of a surfactant solution (for example, a surfactant solution obtained by diluting a neutral detergent containing a surfactant component 10-fold with pure water for the purpose of dispersing toner particles), and after allowing it to mix well, ultrasonic dispersion is performed for 1 minute to prepare a dispersion. This dispersion is pipetted into a beaker containing "ISOTON II" (manufactured by Beckman Coulter, Inc.) in a sample stand until the display concentration of the measuring device reaches 8%.

[0205] Here, by setting the display concentration within the above range, reproducible measurement values can be obtained. Then, in the measuring device, the number of measured particle counts is set to 25,000, the aperture diameter is set to 50 μm, the range of 1 to 30 μm, which is the measurement range, is divided into 256 parts to calculate frequency values, and the particle diameter at 50% from the larger volume integration fraction is defined as the volume-based median diameter (D50).

[0206] [Method for manufacturing toner] The method for manufacturing the toner of the present invention is not particularly limited. For example, when using only the polymer of the present invention as the toner, the polymer is pulverized using a device such as a hammer mill, a feather mill, or a counter jet mill, and then classified to a desired particle size using a dry classifier such as a spin air sieve, a crushier, or a micron classifier. A manufacturing method including this can be used. When manufacturing a toner further containing a colorant, the polymer and the colorant of the present invention are dissolved in a solvent in which both are soluble to form a solution, then the solvent is removed, and thereafter, pulverization and classification can be performed in the same manner as above.

[0207] In particular, the toner containing the polymer of the present invention and, if necessary, a binder and a colorant is preferably produced by a production method using an emulsion aggregation method that enables easy control of particle size and shape.

[0208] Such a production method (1A) A binder resin particle dispersion preparation step of preparing a dispersion of binder resin particles, if necessary (1B) A polymer particle dispersion preparation step of preparing a dispersion of the polymer particles of the present invention (1C) A colorant particle dispersion preparation step of preparing a dispersion of colorant particles, if necessary (2) An aggregation step of adding a flocculant to an aqueous medium in which polymer particles, and if necessary, binder resin particles and colorant particles are present, allowing salting out to proceed while performing aggregation and fusion to form aggregated particles (3) An aging step of forming toner mother particles by controlling the shape of the aggregated particles (4) A filtration and washing step of filtering out the toner mother particles from the aqueous medium and removing a surfactant or the like from the toner mother particles (5) A drying step of drying the washed toner mother particles (6) An external additive addition step of adding an external additive to the dried toner mother particles preferably includes each of the following steps.

[0209] Hereinafter, the steps (1A) to (1C) will be described.

[0210] (1A) Binder resin particle dispersion preparation step In this step, resin particles are formed by conventionally known emulsion polymerization or the like, and these resin particles are aggregated and fused to form binder resin particles. As an example, a dispersion of binder resin particles is prepared by introducing and dispersing polymerizable monomers constituting the binder resin into an aqueous medium and polymerizing these polymerizable monomers with a polymerization initiator.

[0211] In addition to the method of polymerizing a polymerizable monomer with a polymerization initiator in the above aqueous medium as a method for obtaining a binder resin particle dispersion, for example, a method of performing a dispersion treatment in an aqueous medium without using a solvent, or a method of dissolving a crystalline resin in a solvent such as ethyl acetate to form a solution, and then emulsifying and dispersing the solution in an aqueous medium using a disperser, followed by a desolvation treatment, etc. can be mentioned.

[0212] At this time, if necessary, a release agent may be previously contained in the binder resin. Also, for the purpose of dispersion, it is also preferable to polymerize in the presence of a known surfactant (for example, an anionic surfactant such as sodium polyoxyethylene (2) dodecyl ether sulfate, sodium dodecyl sulfate, dodecylbenzenesulfonic acid, etc.).

[0213] The median diameter of the binder resin particles in the dispersion on a volume basis is preferably 50 to 300 nm. The median diameter of the binder resin particles in the dispersion on a volume basis can be measured by the dynamic light scattering method using "Microtrac UPA-150" (manufactured by Nikkiso Co., Ltd.).

[0214] (1B) Polymer Particle Dispersion Preparation Step This polymer particle dispersion preparation step is a step of dispersing the polymer of the present invention in a particulate state in an aqueous medium to prepare a dispersion of the polymer particles.

[0215] In preparing the dispersion of the polymer particles, first, an emulsion of the polymer is prepared. Examples of the emulsion of the polymer include a method of dissolving the polymer in an organic solvent and then emulsifying the resulting solution in an aqueous medium.

[0216] The method of dissolving the polymer in an organic solvent is not particularly limited, and for example, a method of adding the polymer to an organic solvent and stirring and mixing so that the polymer dissolves can be mentioned. The addition amount of the polymer is preferably 5 parts by mass or more and 100 parts by mass or less, more preferably 10 parts by mass or more and 50 parts by mass or less, based on 100 parts by mass of the organic solvent.

[0217] Next, the obtained polymer solution and an aqueous medium are mixed and stirred using a known disperser such as a homogenizer. As a result, the polymer becomes droplets and is emulsified in the aqueous medium, and an emulsion of the polymer is prepared.

[0218] The addition amount of the polymer solution is preferably 10 parts by mass or more and 110 parts by mass or less with respect to 100 parts by mass of the aqueous medium.

[0219] When mixing the polymer solution and the aqueous medium, the temperatures of the polymer solution and the aqueous medium are each in a temperature range below the boiling point of the organic solvent, preferably 20°C or higher and 80°C or lower, more preferably 30°C or higher and 75°C or lower. When mixing the polymer solution and the aqueous medium, the temperature of the polymer solution and the temperature of the aqueous medium may be the same as or different from each other, and are preferably the same as each other.

[0220] For the stirring conditions of the disperser, for example, when the capacity of the stirring container is 1 to 3 L, the rotation speed is preferably 7000 rpm or more and 20000 rpm or less, and the stirring time is preferably 10 minutes or more and 30 minutes or less.

[0221] The dispersion of the polymer particles is prepared by removing the organic solvent from the emulsion of the polymer. Examples of the method for removing the organic solvent from the emulsion of the polymer include known methods such as blowing, heating, reduced pressure, or a combination thereof.

[0222] As an example, the emulsion of the polymer is heated, for example, in an inert gas atmosphere such as nitrogen, preferably at 25°C or higher and 90°C or lower, more preferably at 30°C or higher and 80°C or lower, until, for example, 80% by mass or more and 95% by mass or less of the initial amount of the organic solvent is removed (for example, 20 to 150 minutes), whereby the organic solvent is removed. As a result, the organic solvent is removed from the aqueous medium, and a dispersion of the polymer particles in which the polymer particles are dispersed in the aqueous medium is prepared.

[0223] The mass average particle size of the polymer particles in the dispersion of the polymer particles is preferably 90 nm or more and 1200 nm or less. The above mass average particle size can be set within the above range by appropriately adjusting the viscosity when the polymer is blended in an organic solvent, the blending ratio of the polymer solution and the aqueous medium, the stirring speed of the disperser when preparing the emulsion of the polymer, and the like. The mass average particle size of the polymer particles in the dispersion of the polymer particles can be measured using a Microtrac UPA-150 (manufactured by Nikkiso Co., Ltd.) or an electrophoretic light scattering photometer "ELS-800" (manufactured by Otsuka Electronics Co., Ltd.).

[0224] <organic solvent> The organic solvent used in this step is not particularly limited as long as it can dissolve the polymer and can be used. Specifically, esters such as ethyl acetate and butyl acetate, ethers such as diethyl ether, diisopropyl ether, and tetrahydrofuran, ketones such as acetone and methyl ethyl ketone, saturated hydrocarbons such as hexane and heptane, and halogenated hydrocarbons such as dichloromethane, dichloroethane, and carbon tetrachloride can be mentioned.

[0225] Such organic solvents can be used alone or in a mixture of two or more. Among these organic solvents, ketones and halogenated hydrocarbons are preferred, and methyl ethyl ketone and dichloromethane are more preferred.

[0226] <aqueous medium> The aqueous medium used in this step includes water, or an aqueous medium mainly composed of water and blended with water-soluble solvents such as alcohols and glycols, and optional components such as surfactants and dispersants. Preferably, an aqueous medium obtained by mixing water and a surfactant is used.

[0227] Examples of surfactants include cationic surfactants, anionic surfactants, nonionic surfactants, etc. Examples of cationic surfactants include dodecylammonium chloride, dodecylammonium bromide, dodecyltrimethylammonium bromide, dodecylpyridinium chloride, dodecylpyridinium bromide, hexadecyltrimethylammonium bromide, etc. Examples of anionic surfactants include fatty acid soaps such as sodium stearate and sodium dodecanoate, sodium dodecylbenzenesulfonate, sodium dodecyl sulfate, etc. Examples of nonionic surfactants include polyoxyethylene dodecyl ether, polyoxyethylene hexadecyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene dodecyl ether, polyoxyethylene sorbitan monooleate ether, monodecanoyl sucrose, etc.

[0228] Such surfactants can be used alone or in combination of two or more. Among the surfactants, anionic surfactants are preferably used, and sodium dodecylbenzenesulfonate is more preferably used.

[0229] The addition amount of the surfactant is preferably 0.01 part by mass or more and 10 parts by mass or less, more preferably 0.04 part by mass or more and 1 part by mass or less in terms of solid content based on 100 parts by mass of the aqueous medium.

[0230] (1C) Coloring agent particle dispersion preparation step This coloring agent particle dispersion preparation step is a step of dispersing the coloring agent in the form of fine particles in an aqueous medium to prepare a dispersion of the coloring agent particles.

[0231] The dispersion of the colorant can be carried out using mechanical energy. The median diameter of the colorant particles in the dispersion is preferably from 10 to 300 nm, more preferably from 50 to 200 nm, based on the number of particles. The median diameter of the colorant particles based on the number of particles can be measured using an electrophoretic light scattering photometer "ELS-800" (manufactured by Otsuka Electronics Co., Ltd.).

[0232] (2) Regarding the steps from the aggregation step to the external additive addition step (6), they can be carried out according to various conventionally known methods.

[0233] The flocculant used in the (2) aggregation step is not particularly limited, but those selected from metal salts are preferably used. Examples of metal salts include monovalent metal salts such as salts of alkali metals such as sodium, potassium, and lithium; divalent metal salts such as calcium, magnesium, manganese, and copper; trivalent metal salts such as iron and aluminum. Specific examples of metal salts include sodium chloride, potassium chloride, lithium chloride, calcium chloride, magnesium chloride, zinc chloride, copper sulfate, magnesium sulfate, manganese sulfate, etc. Among these, divalent metal salts are particularly preferably used because aggregation can proceed with a smaller amount. These can be used alone or in combination of two or more.

[0234] [Developer] The toner according to the present invention can be used, for example, when a magnetic material is contained and used as a one-component magnetic toner, when mixed with a so-called carrier and used as a two-component developer, or when a non-magnetic toner is used alone, and can be preferably used in any case.

[0235] As the magnetic material, for example, magnetite, γ-hematite, or various ferrites can be used.

[0236] As the carrier contained in the two-component developer, magnetic particles made of conventionally known materials such as metals such as iron, steel, nickel, cobalt, ferrite, and magnetite, and alloys of these metals with metals such as aluminum and lead can be used.

[0237] As the carrier, it may be a coated carrier in which the surface of the magnetic particles is coated with a coating agent such as resin, or a resin-dispersed carrier in which magnetic powder is dispersed in a binder resin. The resin for coating is not particularly limited, and for example, olefin resin, acrylic resin, styrene resin, styrene-acrylic resin, silicone resin, polyester resin, or fluororesin is used. Further, the resin for constituting the resin-dispersed carrier particles is not particularly limited, and known resins can be used. For example, acrylic resin, styrene-acrylic resin, polyester resin, fluororesin, phenol resin, etc. can be used.

[0238] The median diameter of the carrier on a volume basis is preferably 20 to 100 μm, more preferably 25 to 80 μm. The median diameter of the carrier on a volume basis can typically be measured by a laser diffraction particle size distribution measuring device "HELOS" (manufactured by SYMPATEC) equipped with a wet disperser.

[0239] The mixing amount of the toner with respect to the carrier is preferably 2 to 10% by mass, with the total mass of the toner and the carrier being 100% by mass.

[0240] [Image forming method] The toner of the present invention can be used in various known electrophotographic image forming methods. For example, it can be used in monochrome image forming methods and full-color image forming methods. In the full-color image forming method, it can be applied to any image forming method such as a four-cycle image forming method composed of four color developing devices for yellow, magenta, cyan, and black, respectively, and one photoreceptor, or a tandem image forming method in which image forming units having color developing devices and photoreceptors for each color are mounted separately for each color.

[0241] That is, the image forming method according to an embodiment of the present invention includes: 1) a step of forming a toner image composed of the toner of the present invention on a recording medium; and 2) a step of irradiating the toner image with light to soften the toner image. By being such an embodiment, it has excellent fixability and further has high image quality.

[0242] Regarding the step of 1) In this step, a toner image composed of the toner of the present invention is formed on a recording medium.

[0243] (Recording medium) The recording medium is a member for holding a toner image. Examples of the recording medium include coated printing papers such as plain paper, high-quality paper, art paper, and coated paper, commercially available Japanese paper and postcard paper, resin films for OHP or packaging materials, and cloth.

[0244] The recording medium may be in the form of a sheet (single sheet) having a predetermined size, or may be in a long form that is wound into a roll after the toner image is fixed.

[0245] As will be described later, the formation of the toner image can be performed, for example, by transferring the toner image on the photoreceptor onto the recording medium.

[0246] Regarding the step of 2) In this step, the formed toner image is irradiated with light to soften the toner image. Thereby, the toner image can be adhered to the recording medium.

[0247] The wavelength of the light to be irradiated is not particularly limited as long as it can sufficiently soften the toner image by means of photothermal conversion by the polymer in the toner or the like, but is preferably 280 nm or more and 480 nm or less. If it is within the above range, the toner image can be softened more efficiently. Also, from the same viewpoint, the irradiation amount of light is preferably 0.1 to 200 J / cm 2 , more preferably 0.1 to 100 J / cm 2 , still more preferably 0.1 to 50 J / cm 2 .

[0248] As will be described later, the light irradiation can be performed using a light source such as a light emitting diode (LED) or a laser light source. Also, as will be described later, heating may be further performed together with the light irradiation.

[0249] After the step of 2), if necessary, a step of pressing the softened toner image may be further performed. By being such an embodiment, the fixability is improved.

[0250] Regarding the step of 3) In this step, the softened toner image is pressed.

[0251] The pressure when pressing the toner image on the recording medium is not particularly limited, but is preferably 0.01 to 5.0 MPa, and more preferably 0.05 to 1.0 MPa. By setting the pressure to 0.01 MPa or more, the amount of deformation of the toner image can be increased, so that the contact area between the toner image and the recording paper S increases, and it is easier to further improve the fixability of the image. Also, by setting the pressure to 5.0 MPa or less, shock noise during pressing can be suppressed.

[0252] The pressing step may be performed before or simultaneously with the step of irradiating light and softening the toner image (the step of 2) described above), but it is preferably performed after irradiating light because the toner image in a pre-softened state can be pressed, and as a result, the fixability of the image is further improved.

[0253] Also, in the pressing step, the softened toner image may be further heated. That is, the pressing step may be performed while heating the toner image. The temperature at that time (for example, the temperature of the pressing member) is preferably 15°C or higher, more preferably 20°C or higher, even more preferably higher than 20°C, still more preferably 30°C or higher, and even more preferably 40°C or higher. By being such an embodiment, the fixing property is remarkably improved. There is no particular limitation on the upper limit, but for example, it is 200°C or lower, 150°C or lower, or 100°C or lower.

[0254] The heating temperature of the toner image (the surface temperature of the toner image during heating) is preferably (Tg + 20) to (Tg + 100)°C, more preferably (Tg + 25) to (Tg + 80)°C, when the glass transition temperature of the toner is Tg. If the surface temperature of the toner image is (Tg + 20)°C or higher, the toner image is easily deformed by pressing, and if it is (Tg + 100)°C or lower, it is easy to suppress hot offset. Note that hot offset refers to a phenomenon in the fixing step where a part of the toner transfers to a pressing member such as a roller, and the toner layer is separated.

[0255] Also, before the step of 2), a step of 4) pre-heating the toner image may be further performed as necessary. By thus further performing the step of 4) pre-heating the toner image before the step of 2), the sensitivity of the polymer of the present invention to light can be further enhanced. Thereby, even if it is a polymer, the sensitivity to light is hardly impaired, and it is easy to promote the melting or softening of the toner image by light irradiation.

[0256] The image forming method of the present invention can be performed, for example, by using the following image forming apparatus.

[0257] FIG. 1 is a schematic configuration diagram showing an image forming apparatus 100 used in an image forming method according to an embodiment of the present invention. However, the image forming apparatus used in the present invention is not limited to the following forms and illustrated examples. FIG. 1 shows an example of a monochrome image forming apparatus 100, but the present invention can also be applied to a color image forming apparatus.

[0258] The image forming apparatus 100 is an apparatus that forms an image on a recording sheet S as a recording medium, includes an image reading device 71 and an automatic document feeder 72, and forms an image on the recording sheet S conveyed by a paper conveyance system 7 by an image forming unit 10, an irradiation unit 40, and a pressure bonding unit 9.

[0259] Also, as the recording medium, the image forming apparatus 100 uses a recording sheet S, but the medium to be subjected to image formation may be other than paper.

[0260] A document d placed on the document table of the automatic document feeder 72 is scanned and exposed by the optical system of the scanning exposure device of the image reading device 71 and read into an image sensor CCD. The analog signal photoelectrically converted by the image sensor CCD is input to the exposure device 3 of the image forming unit 10 after analog processing, A / D conversion, shading correction, image compression processing, etc. are performed in the image processing unit 20.

[0261] The paper conveyance system 7 includes a plurality of trays 16, a plurality of paper feeding units 11, conveyance rollers 12, a conveyance belt 13, etc. The trays 16 each accommodate a recording sheet S of a determined size, operate the paper feeding unit 11 of the determined tray 16 in response to an instruction from the control unit 90, and supply the recording sheet S. The conveyance rollers 12 convey the recording sheet S sent out from the tray 16 by the paper feeding unit 11 or the recording sheet S carried in from the manual paper feeding unit 15 to the image forming unit 10.

[0262] The image forming unit 10 is configured such that a charger 2, an exposure device 3, a developing unit 4, a transfer unit 5, and a cleaning unit 8 are arranged in this order along the rotation direction of the photoreceptor 1 around the photoreceptor 1.

[0263] The photoreceptor 1, which is an image carrier, is an image carrier with a photoconductive layer formed on its surface and is configured to be rotatable in the direction of the arrow in FIG. 1 by a driving device (not shown). Near the photoreceptor 1, a thermometer and hygrometer 17 for detecting the temperature and humidity inside the image forming apparatus 100 is provided.

[0264] The charger 2 uniformly charges the surface of the photoreceptor 1 to uniformly charge the surface of the photoreceptor 1. The exposure device 3 includes a beam light source such as a laser diode, and irradiates the surface of the charged photoreceptor 1 with beam light to eliminate the charges in the irradiated portion, thereby forming an electrostatic latent image corresponding to the image data on the photoreceptor 1. The developing unit 4 supplies the toner stored therein to the photoreceptor 1 to form a toner image based on the electrostatic latent image on the surface of the photoreceptor 1.

[0265] The transfer unit 5 faces the photoreceptor 1 through the recording paper S and transfers the toner image to the recording paper S. The cleaning unit 8 includes a blade 85. The blade 85 cleans the surface of the photoreceptor 1 to remove the developer remaining on the surface of the photoreceptor 1.

[0266] The recording paper S onto which the toner image is transferred is conveyed to the pressure bonding unit 9 by the conveying belt 13. The pressure bonding unit 9 is optionally installed, and performs a fixing process on the recording paper S onto which the toner image is transferred by applying only pressure or heat and pressure by the pressure applying members 91 and 92, thereby fixing the image on the recording paper S. The recording paper S on which the image is fixed is conveyed to the paper discharge unit 14 by the conveying roller and discharged outside the machine from the paper discharge unit 14.

[0267] Also, the image forming apparatus 100 includes a paper reversing unit 24, conveys the recording paper S on which the heat fixing process has been performed in front of the paper discharge unit 14 to the paper reversing unit 24, reverses the front and back sides and discharges it, or conveys the recording paper S with the front and back sides reversed back to the image forming unit 10 to enable image formation on both sides of the recording paper S.

[0268] <Irradiation unit> FIG. 2 is a schematic configuration diagram of the irradiation unit 40 in the image forming apparatus 100.

[0269] An image forming apparatus 100 according to an embodiment of the present invention includes an irradiation unit 40. The irradiation unit 40 includes a light source 41 and a heating member 93. Examples of devices constituting the light source 41 include a light emitting diode (LED), a laser light source, and the like.

[0270] The light source 41 irradiates light onto the toner image formed on the recording medium to soften the toner image. The conditions for light irradiation are not particularly limited as long as they can melt and fluidize the composition of the present invention contained in the toner of the developer. The wavelength of the light irradiated onto the toner image may be such that the composition can be sufficiently fluidized, preferably in the range of 280 nm or more and 480 nm or less, more preferably in the range of 300 nm or more and 420 nm or less, and even more preferably in the range of 330 nm or more and 420 nm or less. The light irradiation amount in the light source 41 may also be such that it can be sufficiently fluidized, for example, 0.1 J / cm 2 or more and 200 J / cm 2 or less, preferably 0.1 J / cm 2 or more and 100 J / cm 2 or less, more preferably 0.1 J / cm 2 or more and 50 J / cm 2 or less.

[0271] When irradiating the toner image with light from the light source 41 to soften the toner image, the toner image may be heated by the heating member 93 together with the light irradiation. Thereby, the softening and melting of the toner image can proceed more efficiently. The heating temperature at this time is, for example, in the range of 20°C or more and 200°C or less, preferably in the range of 20°C or more and 150°C or less.

[0272] The softened toner image can be solidified and fixed to the recording medium by leaving it at room temperature (in the range of 25 ± 15°C), heating it, or irradiating it with visible light. As will be described later, in the fixing step, it is preferable to further include a step of pressing the softened toner image. In the pressing step, it is preferable to further heat the softened toner image.

[0273] The light source 41 irradiates light toward the first surface on the photoreceptor side of the recording paper S that holds the toner image, and is disposed on the photoreceptor side with respect to the surface of the recording paper S nipped between the photoreceptor 1 and the transfer roller 5 which is the transfer unit. And, a heating member 93 is disposed on the side opposite to the light source 41 with respect to the surface of the recording paper S. Further, the light source 41 and the heating member 93 are disposed along the conveyance direction (paper conveyance direction) of the recording paper S.

[0274] The light source 41 and the heating member 93 are disposed on the downstream side in the paper conveyance direction with respect to the nip position between the photoreceptor 1 and the transfer roller 5, and on the upstream side in the paper conveyance direction with respect to the pressure bonding unit 9.

[0275] According to the image forming method according to an embodiment of the present invention, after uniformly charging the photoreceptor 1 by the charger 2, the photoreceptor 1 is scanned with a light beam irradiated by the exposure device 3 based on the original image data to form an electrostatic latent image. Next, a developer having toner containing the composition of the present invention is supplied onto the photoreceptor 1 by the developing unit 4.

[0276] When the recording paper S is conveyed from the tray 16 to the image forming unit 10 at the timing when the toner image carried on the surface of the photoreceptor 1 reaches the position of the transfer roller 5 which is the transfer unit due to the rotation of the photoreceptor 1, the transfer bias applied to the transfer roller 5 causes the toner image on the photoreceptor 1 to be transferred onto the recording paper S nipped between the transfer roller 5 and the photoreceptor 1.

[0277] Further, the transfer unit 5 also serves as a pressure member, and can reliably adhere the toner image to the recording paper S while transferring the toner image from the photoreceptor 1 to the recording paper S.

[0278] After the toner image is transferred to the recording paper S, the blade 85 of the cleaning unit 8 removes the developer remaining on the surface of the photoreceptor 1.

[0279] In the process where the recording paper S with the toner image transferred is conveyed to the pressure bonding part 9 by the conveying belt 13, the light source 41 irradiates light onto the toner image transferred onto the recording paper S. By irradiating light from the light source 41 toward the toner image on the first surface of the recording paper S, the toner image can be more reliably melted, and the fixability of the toner image to the recording paper S can be improved.

[0280] When the recording paper S holding the toner image reaches the pressure bonding part 9 by the conveying belt 13, the pressure applying members 91 and 92 press the toner image onto the first surface of the recording paper S. Before the fixing process is performed by the pressure bonding part 9, since the toner image is softened by the light irradiation from the light source 41, energy saving of the image pressure bonding to the recording paper S can be achieved. Further, in the step of solidifying the toner image and fixing it to the recording medium, by pressing the toner image with the pressure applying members 91 and 92, the fixability of the toner image to the recording paper S is further improved.

[0281] The pressure when pressing the toner image is as described above. Note that the pressing step may be performed before or simultaneously with the step of irradiating light to soften the toner image, or may be performed later. Since the toner image in a pre-softened state can be pressed, from the viewpoint of easily increasing the image intensity, it is preferable that the pressing step is performed after the light irradiation.

[0282] Also, the pressure applying member 91 can heat the toner image on the recording paper S when the recording paper S passes between the pressure applying members 91 and 92. The toner image softened by the light irradiation is further softened by this heating, and as a result, the fixability of the toner image to the recording paper S is further improved.

[0283] The heating temperature of the toner image is as described above. The heating temperature of the toner image (the surface temperature of the toner image) can be measured by a non-contact temperature sensor. Specifically, for example, a non-contact temperature sensor may be installed at the position where the recording medium is discharged from the pressure applying member to measure the surface temperature of the toner image on the recording medium.

[0284] The toner image pressed by the pressing members 91 and 92 is solidified and fixed on the recording paper S.

[0285] In one embodiment of the present invention, the fixing device has a pressure-bonding part including a pressing member.

[0286] In one embodiment of the present invention, the pressing member has a heating means.

[0287] In one embodiment of the present invention, the temperature of the pressing member is preferably 15°C or higher, more preferably 20°C or higher, even more preferably higher than 20°C, still more preferably 30°C or higher, and still more preferably 40°C or higher. There is no particular limitation on the upper limit, but for example, it is 200°C or lower, 150°C or lower, or 100°C or lower.

[0288] <Photoresponsive adhesive, photoswitching material> Since the polymer of the present invention is fluidized by light irradiation and reversibly non-fluidized, a photoresponsive adhesive (photosensitive adhesive) and a photoswitching material that can be repeatedly used can be produced using the polymer of the present invention. For example, it can be applied to various adhesion technologies as a photoresponsive adhesive that can be repeatedly photo-desorbed corresponding to a change in viscosity (friction coefficient). That is, one embodiment of the present invention is a photoresponsive adhesive or a photoswitching material containing the polymer of the present invention.

[0289] The photoresponsive adhesive of the present invention can be used for temporary fixing that can be repeatedly used and is also suitable for recycling, but is not limited thereto.

Examples

[0290] Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

[0291] <Synthesis of azomethine derivative monomer> (Synthesis of azomethine derivative monomer 1) Into a 100 ml four-necked flask, 2,6-dimethyl-4-hydroxybenzaldehyde (6.9 g, 0.046 mol), 4-amino-1-methylpyrazole (4.5 g, 0.046 mol), and 100 ml of ethanol were added, and the mixture was heated and stirred. The reaction solution was suction filtered, and the obtained powder was washed with cooled ethanol. Further, recrystallization was performed with methanol / ethanol to obtain the target product 1.

[0292]

Chemical formula

[0293] Next, in a 200 ml four-necked flask, the target product 1 (5 g, 0.022 mol) obtained above was dissolved in 25 ml of dimethylformamide (DMF). To this, 4.88 g (0.035 mol) of potassium carbonate was added, and the mixture was stirred while maintaining the temperature at 30 °C. To this, 10.2 mg (0.06 mmol) of potassium iodide and 3.5 g (0.026 mol) of 6-chloro-1-hexanol were added, and the reaction was carried out at 110 °C. This was cooled to room temperature, added to 650 g of ice, and then filtered. The crystals were dispersed in 400 ml of water, stirred and washed overnight, filtered, and dried. Further, recrystallization was performed with ethanol to obtain the target product 2.

[0294]

Chemical formula

[0295] Next, into a 100 ml four-necked flask, the target product 2 (3.30 g, 0.01 mol) obtained above, 1.34 ml (0.01 mol) of triethylamine, and 30 ml of tetrahydrofuran (THF) were added. At this time, the raw materials were in a dispersed state. While maintaining the internal temperature at 0 °C, a solution prepared by dissolving 1.0 g (0.011 mol) of acryloyl chloride in 10 ml of THF was added dropwise while maintaining the internal temperature at 0 - 5 °C. As the dropwise addition proceeded, the raw materials dissolved.

[0296] After the dropping was completed, the reaction solution was returned to room temperature and stirred. After the reaction was completed, THF was concentrated and removed, dissolved in ethyl acetate, and washed with dilute hydrochloric acid, aqueous sodium hydrogen carbonate solution, and saturated brine. The organic layer was dried over magnesium sulfate and then concentrated. The obtained crystals were purified by a silica gel column (ethyl acetate / heptane = 1 / 5) to obtain azomethine derivative monomer 1.

[0297] [Chemical formula]

[0298] (Synthesis of azomethine derivative monomers 2 - 15, comparative monomers 1 - 8) The synthesis of azomethine derivative monomers 2 - 15 and comparative monomers 1 - 8 was carried out in the same manner as the synthesis of azomethine derivative monomer 1 by changing the raw materials as follows to obtain the target products.

[0299] (Synthesis of azomethine derivative monomer 2) 4 - Amino - 1 - methylpyrazole was changed to 4 - amino - 1 - hexylpyrazole.

[0300] (Synthesis of azomethine derivative monomer 3) 2,6 - Dimethyl - 4 - hydroxybenzaldehyde was changed to 2,6 - diethyl - 4 - hydroxybenzaldehyde.

[0301] (Synthesis of azomethine derivative monomer 4) 2,6 - Dimethyl - 4 - hydroxybenzaldehyde was changed to 2,6 - dipropyl - 4 - hydroxybenzaldehyde.

[0302] (Synthesis of azomethine derivative monomer 5) 2,6 - Dimethyl - 4 - hydroxybenzaldehyde was changed to 2,6 - dimethoxy - 4 - hydroxybenzaldehyde.

[0303] (Synthesis of azomethine derivative monomer 6) 2,6-Dimethyl-4-hydroxybenzaldehyde was changed to 2,6-fluoro-4-hydroxybenzaldehyde.

[0304] (Synthesis of azomethine derivative monomer 7) 4-Amino-1-methylpyrazole was changed to 1-methyl-1H-pyrrol-3-amine, and 6-chloro-1-hexanol was changed to 10-chloro-1-decanol.

[0305] (Synthesis of azomethine derivative monomer 8) 2,6-Dimethyl-4-hydroxybenzaldehyde was changed to 1-hexyl-1H-pyrrole-3-carboxaldehyde, and 4-amino-1-methylpyrazole was changed to 4-amino-3,5-dimethylphenol.

[0306] (Synthesis of azomethine derivative monomer 9) 4-Amino-1-methylpyrazole was changed to 1-methyl-1H-pyrrol-2-amine.

[0307] (Synthesis of azomethine derivative monomer 10) 4-Amino-1-methylpyrazole was changed to 6-aminoindole.

[0308] (Synthesis of azomethine derivative monomer 11) 4-Amino-1-methylpyrazole was changed to 3-amino-1-methylpyrazole.

[0309] (Synthesis of azomethine derivative monomer 12) 4-Amino-1-methylpyrazole was changed to 2-aminoimidazole, and 6-chloro-1-hexanol was changed to 10-chloro-1-decanol.

[0310] (Synthesis of azomethine derivative monomer 13) 4-Amino-1-methylpyrazole was changed to 5-hexyl-2-thiopheneamine, and 6-chloro-1-hexanol was changed to 10-chloro-1-decanol.

[0311] (Synthesis of Azomethine Derivative Monomer 14) 2,6-Dimethyl-4-hydroxybenzaldehyde was changed to 5-methylthiophene-2-carboxaldehyde, and 4-amino-1-methylpyrazole was changed to 4-amino-3,5-dimethylphenol.

[0312] (Synthesis of Azomethine Derivative Monomer 15) Acrylic acid chloride was changed to methacrylic acid chloride.

[0313] (Synthesis of Comparative Monomer 1) 2,6-Dimethyl-4-hydroxybenzaldehyde was changed to 2-methyl-4-hydroxybenzaldehyde, and 4-amino-1-methylpyrazole was changed to 4-amino-1-hexylpyrazole.

[0314] (Synthesis of Comparative Monomer 2) 2,6-Dimethyl-4-hydroxybenzaldehyde was changed to 2,5-dimethyl-4-hydroxybenzaldehyde.

[0315] (Synthesis of Comparative Monomer 3) 2,6-Dimethyl-4-hydroxybenzaldehyde was changed to 2-fluoro-4-hydroxybenzaldehyde, and 4-amino-1-methylpyrazole was changed to 4-amino-1-ethylpyrazole.

[0316] (Synthesis of Comparative Monomer 4) 2,6-Dimethyl-4-hydroxybenzaldehyde was changed to 1-methyl-1H-pyrazole-4-carboxaldehyde, and 4-amino-1-methylpyrazole was changed to 4-amino-2,5-dimethylphenol.

[0317] (Synthesis of Comparative Monomer 5) 2,6-Dimethyl-4-hydroxybenzaldehyde was changed to 1-methyl-1H-pyrazole-4-carboxaldehyde, and 4-amino-1-methylpyrazole was changed to 4-amino-3-fluorophenol.

[0318] (Synthesis of Comparative Monomer 6) 2,6 - Dimethyl - 4 - hydroxybenzaldehyde was changed to 1 - methyl - 1H - pyrazole - 4 - carboxaldehyde, and 4 - amino - 1 - methylpyrazole was changed to 4 - amino - 3 - methoxyphenol.

[0319] (Synthesis of Comparative Monomer 7) 2,6 - Dimethyl - 4 - hydroxybenzaldehyde was changed to 1 - hydroxypyrazole - 4 - carbaldehyde, and 4 - amino - 1 - methylpyrazole was changed to 4 - hexyloxy - 2,5 - dimethylaniline.

[0320] (Synthesis of Comparative Monomer 8) 2,6 - Dimethyl - 4 - hydroxybenzaldehyde was changed to - 4 - hydroxybenzaldehyde, and 4 - amino - 1 - methylpyrazole was changed to 1 - methyl - 1H - pyrrole - 3 - amine.

[0321] (Synthesis of Azobenzene Derivative (Comparative 9)) The following comparative compounds (number - average molecular weight Mn: 2870) were obtained by the method described in paragraphs 0217 - 0227 of JP - A - 2014 - 191078.

[0322]

Chemical formula

[0323] The structures of the obtained azomethine - derivative monomers 1 - 15 and comparative monomers 1 - 8 are shown in Table 1 below. In Table 1, the structure of A refers to A in the structural unit described in the above general formula (2).

[0324] [Synthesis of Polymer] (Synthesis of Polymer 1) In a 100 mL four-necked flask, 1.61 g (4.2 mmol) of the azomethine derivative monomer 1 obtained above, 5 mg (0.023 mmol) of dithiobenzoate 4-cyanopentanoate, and 1 mg (0.006 mmol) of AIBN were dissolved in 4 mL of anisole. Then, after creating an argon gas atmosphere by freeze-degassing, the temperature was raised to 75 °C and polymerization was carried out by stirring for 8 hours. To the obtained polymer solution, 40 mL of methanol was gradually added dropwise, and then THF was added to remove the unreacted azomethine derivative monomer 1. The separated polymer solution was dried in a vacuum drying oven at 40 °C for 24 hours to obtain an azomethine derivative-containing polymer 1. When the number average molecular weight Mn of the obtained polymer 1 was measured by the GPC method, it was 13,000.

[0325] In addition, the measurement of the molecular weight distribution by GPC was carried out as follows.

[0326] That is, using the apparatus "HLC-8220" (manufactured by Tosoh Corporation) and the column "TSKguardcolumn + TSKgel SuperHZM-M3 series" (manufactured by Tosoh Corporation), while maintaining the column temperature at 40 °C, tetrahydrofuran (THF) was used as the carrier solvent and flowed at a flow rate of 0.2 mL / min. The measurement sample was dissolved in tetrahydrofuran to a concentration of 1 mg / mL under dissolution conditions where it was treated for 5 minutes using an ultrasonic disperser at room temperature (25 °C). Then, it was treated with a membrane filter with a pore size of 0.2 μm to obtain a sample solution. 10 μL of this sample solution was injected into the apparatus together with the above carrier solvent, and detection was carried out using a refractive index detector (RI detector). The molecular weight distribution of the measurement sample was calculated using a calibration curve measured using monodisperse polystyrene standard particles. As the standard polystyrene sample for calibration curve measurement, those manufactured by Pressure Chemical with molecular weights of 6×10 2 , 2.1×10 3 , 4×10 3 , 1.75×10 4 , 5.1×10 4 , 1.1×10 5 , 3.9×10 5 , 8.6×10 5 , 2×10 6 , 4.48×106 Using this, 10 standard polystyrene samples were measured to create a calibration curve. Also, a refractive index detector was used as the detector.

[0327] The number average molecular weight Mn was calculated from the chromatogram showing the molecular weight distribution measured by GPC as described above.

[0328] <Synthesis of Polymers 2 - 16 and Comparative Polymers 1 - 8> In the synthesis of Polymer 1, by changing azomethine derivative monomer 1 to azomethine derivative monomers 2 - 15 and comparative polymers 1 - 8 and appropriately adjusting the polymerization conditions as necessary, Polymers 2 - 15 and comparative polymers 1 - 8 shown in Table 2 below were synthesized. Polymer 16 was prepared by appropriately changing the polymerization time in the synthesis of Polymer 1.

[0329] <Synthesis of Polymer 17> Polymer 17 was obtained in the same manner as in the synthesis of Polymer 1, except that 1.61 g of azomethine derivative monomer 1 was replaced with 1.01 g of azomethine derivative monomer and 0.6 g of styrene was used.

[0330] <Synthesis of Polymers 18 - 20> In the synthesis of Polymer 17, 0.6 g of styrene was changed to 0.6 g of ethyl acrylate, 0.6 g of n - butyl methacrylate, and 0.3 g / 0.3 g of styrene / methyl acrylate respectively to obtain Polymers 18 - 20.

[0331] <Synthesis of Polymer 21> Synthesis of Macroinitiator 21 In a 100 ml eggplant flask, 2,2'-bipyridyl (230 mg, 1.47 mmol) was placed, and in a glove box under a nitrogen atmosphere, Cu(I)Br (95 mg, 0.66 mmol), styrene (3.7 g, 36 mmol), and ethyl 2-bromoisobutyrate (35 mg, 0.18 mmol) were further added and sealed. This was heated and stirred in an oil bath at 100 °C. Then, an appropriate amount of tetrahydrofuran was added and passed through a neutral alumina column. This was purified by reprecipitation with methanol and centrifugation to obtain the macroinitiator 21. When the number average molecular weight (β Mn) of the obtained macroinitiator 21 was measured by the GPC method, it was 6000.

[0332] Synthesis of Polymer 21 In a 100 ml eggplant flask, the azomethine derivative monomer 1 (4.1 g, 10.7 mmol) obtained above and the above macroinitiator 21 (1.08 g, 0.18 mmol) were placed, and in a glove box under a nitrogen atmosphere, Cu(I)Cl (29 mg, 0.29 mmol), 1,1,4,7,10,10-hexamethyltriethylenetetramine (136 mg, 0.59 mmol), and anisole (4.9 g, 41.1 mmol) as a solvent were further added and sealed. Then, it was heated and stirred in an oil bath at 80 °C. Then, an appropriate amount of chloroform was added and passed through a basic alumina column. This was purified by reprecipitation with methanol and centrifugation to obtain Polymer 21. When the number average molecular weight Mn of the obtained Polymer 21 was measured by the GPC method, it was 16000. From this, the number average molecular weight (α Mn) of the structural unit derived from the azomethine derivative was determined to be 10000.

[0333] <Synthesis of Polymer 22> Synthesis of Macroinitiator 22 The macroinitiator 22 was obtained in the same manner as in the synthesis of the macroinitiator 21, except that ethyl 2-bromoisobutyrate was changed to α,α'-dibromo-p-xylene.

[0334] Synthesis of Polymer 22 The polymer 22 was obtained in the same manner as in the synthesis of the polymer 21, except that the macroinitiator 21 was changed to the macroinitiator 22.

[0335] <Synthesis of Polymer 23> Synthesis of Macroinitiator 23 The macroinitiator 23 was obtained in a similar manner to the synthesis of the macroinitiator 21, except that ethyl 2-bromoisobutyrate was changed to ethylene bis(2-bromoisobutyrate), 2,2'-bipyridyl was changed to 1,1,4,7,10,10-hexamethyltriethylenetetramine, styrene was changed to azomethine derivative monomer 1, and anisole was further added.

[0336] Synthesis of Polymer 23 The polymer 23 was obtained in a similar manner to the synthesis of the polymer 21, except that the macroinitiator 21 was changed to the macroinitiator 23, 1,1,4,7,10,10-hexamethyltriethylenetetramine was changed to 2,2'-bipyridyl, and azomethine derivative monomer 1 was changed to styrene.

[0337] <Synthesis of Polymer 24> The macroinitiator 24 was obtained in a similar manner to the synthesis of the macroinitiator 21, except that ethyl 2-bromoisobutyrate was changed to 1,1,1-tris(2-bromoisobutyryloxymethyl)ethane. The polymer 24 was obtained in a similar manner to the synthesis of the polymer 21, except that the macroinitiator 21 was changed to the macroinitiator 24.

[0338] <Synthesis of Polymer 25> The macroinitiator 25 was obtained in a similar manner to the synthesis of the macroinitiator 23, except that ethylene bis(2-bromoisobutyrate) was changed to 1,1,1-tris(2-bromoisobutyryloxymethyl)ethane. The polymer 25 was obtained in a similar manner to the synthesis of the polymer 23, except that the macroinitiator 23 was changed to the macroinitiator 32.

[0339] <Synthesis of Polymer 26> In the synthesis of macroinitiator 21, macroinitiator 26 was obtained in the same manner except that ethyl 2-bromoisobutyrate was changed to pentaerythritol tetrakis(2-bromoisobutyrate). In the synthesis of polymer 21, polymer 26 was obtained in the same manner except that macroinitiator 21 was changed to macroinitiator 26.

[0340] <Synthesis of Polymer 27> In the synthesis of macroinitiator 23, macroinitiator 27 was obtained in the same manner except that ethylenebis(2-bromoisobutyric acid) was changed to pentaerythritol tetrakis(2-bromoisobutyrate). In the synthesis of polymer 23, polymer 27 was obtained in the same manner except that macroinitiator 23 was changed to macroinitiator 27.

[0341] <Synthesis of Polymer 28> In the synthesis of macroinitiator 22, macroinitiator 28 was obtained in the same manner except that styrene was changed to methyl acrylate. In the synthesis of polymer 22, polymer 28 was obtained in the same manner except that macroinitiator 22 was changed to macroinitiator 28.

[0342] The polymer structure of the obtained polymers, the monomers constituting the polymers, the number-average molecular weight of the polymers, and the number-average molecular weight of each polymer block constituting the block copolymer are shown in Table 2.

[0343] [Preparation of Toner] <Preparation of Toner 1> (Preparation of Polymer Particle Dispersion Liquid 1) 80 parts by mass of dichloromethane and 20 parts by mass of Polymer 1 obtained above were mixed and stirred while heating at 50 °C to obtain a solution containing Polymer 1. To 100 parts by mass of the obtained solution, a mixed solution of 99.5 parts by mass of distilled water warmed to 50 °C and 0.5 parts by mass of a 20% by mass aqueous solution of sodium dodecylbenzenesulfonate was added. Then, it was stirred and emulsified at 16000 rpm for 20 minutes using a homogenizer (manufactured by Hielscher) equipped with a shaft generator 18F to obtain an emulsion of Polymer 1.

[0344] The obtained emulsion was put into a separable flask and heated and stirred at 40 °C for 90 minutes while introducing nitrogen into the gas phase to remove the organic solvent, thereby obtaining Polymer Particle Dispersion Liquid 1. When the particle diameter of the polymer particles in Polymer Particle Dispersion Liquid 1 was measured using Microtrac UPA-150 (manufactured by Nikkiso Co., Ltd.), the mass average particle diameter was 175 nm.

[0345] (Preparation of Black Colorant Particle Dispersion Liquid (Bk-1)) 90 parts by mass of sodium n-dodecyl sulfate was added to 1600 parts by mass of ion-exchanged water. While stirring this solution, 320 parts by mass of carbon black "Regal (registered trademark) 330R" (manufactured by Cabot Corporation) was gradually added to the solution, and then, by performing a dispersion treatment using a stirrer "Clear Mix" (manufactured by M. Technique Co., Ltd.), Black Colorant Particle Dispersion Liquid (Bk-1) was prepared. The median diameter of the colorant particles in the Black Colorant Particle Dispersion Liquid (Bk-1) based on volume was 110 nm.

[0346] (Preparation of Toner 1) 480 parts by mass (in terms of solid content) of the particle dispersion liquid of Polymer 1 and 2000 parts by mass of ion-exchanged water were put into a reaction vessel equipped with a stirrer, a temperature sensor, and a cooling pipe. Then, while stirring at 150 rpm, a 5 mol / L aqueous sodium hydroxide solution was added to adjust the pH (converted to 25 °C) to 10.

[0347] Thereafter, 24 parts by mass (in terms of solid content) of the colorant particle dispersion liquid (Cy1) was added, and then, an aqueous solution prepared by dissolving 60 parts by mass of magnesium chloride in 60 parts by mass of ion-exchanged water was added over 10 minutes at 30 °C while stirring at 150 rpm. After leaving this system standing for 3 minutes, the temperature was raised to 70 °C over 60 minutes while stirring at 200 rpm, and the particle growth reaction was continued while maintaining 70 °C. In this state, the particle diameter of the aggregated particles was measured with a "Coulter Multisizer 3" (manufactured by Beckman Coulter, Inc.), and the median diameter (D 50) When it reached 6.1 μm, an aqueous solution prepared by dissolving 20 parts by mass of sodium chloride in 80 parts by mass of ion-exchanged water was added to stop particle growth. After stirring at 70 °C for 1 hour, the temperature was further raised, and heating and stirring were carried out at 75 °C to promote particle fusion. Then, by cooling to 30 °C, a dispersion of toner mother particles was obtained.

[0348] Next, solid-liquid separation was performed, and the operation of redispersing the dehydrated toner cake in ion-exchanged water and performing solid-liquid separation was repeated three times for washing. Then, the toner mother particles were obtained by drying at 40 °C for 24 hours.

[0349] 1.5% by mass of hydrophobic silica (number-average primary particle size: 12 nm) was added to the obtained toner mother particles and mixed using a Henschel mixer (registered trademark) to obtain Toner 1.

[0350] <Preparation of Toners 2 to 28 and Comparative Toners 1 to 9> In the preparation of Toner 1, Toners 2 to 28 and Comparative Toners 1 to 8 were prepared in the same manner as Toner 1, except that Polymers 2 to 28 and Comparative Polymers 1 to 8 were used instead of Polymer 1. Comparative Toner 9 was prepared in the same procedure as Toner 1, except that Polymer 1 was changed to the above-mentioned azobenzene derivative (Comparative 9) which is a comparative compound.

[0351] <Preparation of Toner 29> (Preparation of Styrene-Acrylic Resin Particle Dispersion) 5.0 parts by mass of sodium lauryl sulfate and 2500 parts by mass of ion-exchanged water were placed in a 5 L reaction vessel equipped with a stirrer, a temperature sensor, a cooling tube, and a nitrogen introduction device. While stirring at a stirring speed of 230 rpm under a nitrogen stream, the internal temperature was raised to 80 °C.

[0352] Next, an aqueous solution prepared by dissolving 15.0 parts by mass of potassium persulfate (KPS) in 300 parts by mass of ion-exchanged water was added, and the liquid temperature was set to 80 °C again. Then, a monomer mixture consisting of 840.0 parts by mass of styrene (St), 288.0 parts by mass of n-butyl acrylate (BA), 72.0 parts by mass of methacrylic acid (MAA), and 15 parts by mass of n-octyl mercaptan was added dropwise over 2 hours. After the addition was completed, polymerization was carried out by heating and stirring at 80 °C for 2 hours, and a dispersion liquid a1 of styrene acrylic resin A1 particles with a volume-based median diameter of 120 nm was prepared. The glass transition temperature (Tg) of the styrene acrylic resin A1 was 52.0 °C, and the weight average molecular weight (Mw) was 28,000.

[0353] (Preparation of Toner 29) In the preparation of Toner 1, Toner 29 was obtained in the same manner except that 480 parts by mass (in terms of solid content) of the polymer 1 particle dispersion liquid was changed to 336 parts by mass (in terms of solid content) of the polymer 1 particle dispersion liquid and 144 parts by mass (in terms of solid content) of the dispersion liquid a1 of styrene acrylic resin A1 particles.

[0354] (Preparation of Toner 30) (Preparation of Amorphous Polyester Resin Dispersion Liquid) Into a reaction vessel equipped with a stirrer, a thermometer, a condenser, and a nitrogen gas introduction tube, monomers having the following composition and 0.25 parts by mass of tin dioctylate with respect to a total of 100 parts by mass of the monomers having the following composition were charged. After reacting at 235 °C for 6 hours under a nitrogen gas stream, the temperature was lowered to 200 °C and reacted for 1 hour. The temperature was raised to 220 °C over 5 hours, and polymerization was carried out under a pressure of 10 kPa until the desired molecular weight was reached to obtain a pale yellow transparent amorphous polyester resin (B1). The weight average molecular weight of the amorphous polyester resin (B1) was 18,000, and the acid value was 17.8 mgKOH / g: Bisphenol A ethylene oxide 2 mol adduct 50.2 parts by mass Bisphenol A propylene oxide 2 mol adduct 249.8 parts by mass Terephthalic acid 82.5 parts by mass Fumaric acid 32.0 parts by mass.

[0355] 72 parts by mass of the above amorphous polyester resin (B1) was added to 72 parts by mass of methyl ethyl ketone and dissolved by stirring at 30 °C for 30 minutes. 2.1 parts by mass of a 25% by mass aqueous sodium hydroxide solution was added to this oil-phase liquid and placed in a reaction vessel equipped with a stirrer. While stirring the oil-phase liquid, 252 parts by mass of ion-exchanged water at 30 °C was added dropwise over 70 minutes and mixed. During the dropwise addition, the liquid in the container became turbid, and after the total amount was added dropwise, an emulsion in a uniform emulsified state was obtained.

[0356] This emulsion was heated to 60 °C using a diaphragm-type vacuum pump V-700 (manufactured by BUCHI) and stirred under a reduced pressure of 15 kPa (150 mbar) for 3 hours to distill off methyl ethyl ketone, thereby preparing an amorphous polyester resin particle dispersion (b1).

[0357] (Preparation of Toner 30) In the preparation of Toner 1, Toner 30 was obtained in the same manner except that 480 parts by mass (in terms of solid content) of the polymer 1 particle dispersion was changed to 336 parts by mass (in terms of solid content) of the polymer 1 particle dispersion and 144 parts by mass (in terms of solid content) of the dispersion b1 of amorphous polyester resin B1 particles.

[0358] (Preparation of Developer) Regarding the above-prepared Toners 1 to 30 and Comparative Toners 1 to 9, ferrite carrier particles with a volume average particle diameter of 30 μm coated with a copolymer resin of cyclohexane methacrylate and methyl methacrylate (monomer mass ratio 1:1) were mixed so that the toner particle concentration was 6% by mass to obtain Developers 1 to 30 and Comparative Developers 1 to 9. The mixing was carried out for 30 minutes using a V-type mixer.

[0359] [Evaluation: Photoresponse Adhesion Test of Polymer] Using the apparatus shown in Fig. 3, which shows the changes in adhesiveness accompanying light irradiation of the polymers 1 to 28, comparative polymers 1 to 8, and the azomethine derivative (Comparative 9) which is a comparative compound prepared above, the following photo-responsive adhesion test was evaluated. As shown in Fig. 3, 4 mg of the polymer was placed on a 18 mm square cover glass 1 within a radius of 6 mm from the center of the glass, and a cover glass 2 of the same size was placed so as to cover all of the polymer at a position shifted by about 4 mm in a direction parallel to cover glass 1. This was heated to melt the sample and bond cover glass 1 and cover glass 2 together. Each of the obtained samples was subjected to the following non-fluid → fluidity test, and then to the following fluidity → non-fluidity (return) test.

[0360] <Non-fluid → fluidity test> The (A) part shown in Fig. 3 was fixed to the table with cellophane tape, and a 30 cm long vinyl string with a 150 g weight attached to the (C) part was fixed with cellophane tape. The (B) part was irradiated with light of 365 nm at an irradiation dose of 18 J / cm 2 and it was confirmed whether cover glass 2 peeled off from cover glass 1, and judgment was made according to the following evaluation criteria: - Evaluation criteria for non-fluid → fluidity test - ◎: Cover glass 2 was completely peeled off from cover glass 1 〇: Cover glass 2 and cover glass 1 were displaced ×: Cover glass 2 did not move.

[0361] <Fluidity → non-fluidity (return) test> After the non-fluid → fluidity test was completed, the following experiment was conducted on the samples where cover glass 2 was completely peeled off and the displaced samples. For the displaced samples, cover glasses 1 and 2 were peeled off by hand. 10 minutes after the end of light irradiation in the non-fluid → fluidity test (10 minutes was left standing in a natural environment, i.e., at room temperature in a dark room), a cover glass 3 (the same size as cover glasses 1 and 2) was placed so as to cover the sample part ((B) part) of cover glass 1 used in the above test, and it was confirmed whether cover glass 1 and cover glass 3 adhered, and judgment was made according to the following evaluation criteria: - Evaluation criteria for fluidity → non-fluidity (return) test - ◎: Did not adhere (not fluidized) 〇: Partially adhered (partially maintained a fluidized state) ×: Adhered (maintained a fluidized state).

[0362] [Evaluation: Fixing test] The fixing test was carried out in a normal temperature and humidity environment (temperature 20°C, relative humidity 50%RH) using the developers 1 to 30 and comparative developers 1 to 9 obtained above. On one side was the developer, and on the other side was paper as a recording medium (Mondi color copy paper, basis weight: 120 g / m 2 ). The developer was placed while being slid by magnetic force between a pair of parallel plate (aluminum) electrodes, and the toner was developed under the conditions that the gap between the electrodes was 0.5 mm and the DC bias and AC bias were such that the toner adhesion amount was 5 g / m 2 . A toner layer was formed on the surface of the above paper and fixed by each fixing device to obtain a printed matter (image formation). The toner image of 1 cm square of this printed matter was rubbed 15 times with a "JK wiper (registered trademark)" (manufactured by Nippon Paper Crecia Co., Ltd.) under a pressure of 50 kPa, and the fixing rate of the image was evaluated. The results are shown in Table 3 below. A fixing rate of 75% or more was considered passing. The fixing rate of the image is a numerical value expressed as a percentage of the value obtained by dividing the reflection density of the image after rubbing by the reflection density of the solid image after printing, where the reflection densities of the image after printing and the image after rubbing were measured with a fluorescence spectroscopic densitometer "FD-7" (manufactured by Konica Minolta Inc.).

[0363] The following four types of fixing devices were used, which were configured by appropriately modifying the device shown in Figure 2: No.1: There is no crimping part 9 in Figure 2, the wavelength of the ultraviolet light irradiated from the irradiation part 40 is 365 nm (light source: LED light source with an emission wavelength of 365 nm ± 10 nm), and the irradiation amount is 12 J / cm 2 ; No.2: There is a crimping part 9 in Figure 2, the temperature of the pressing member 91 is 20°C, and the pressure during pressing is 0.2 MPa. The light source and irradiation amount of the irradiation part 40 are the same as those of No.1; No.3: There is a crimping part 9 in Figure 2. The temperature of the pressing member 91 is 50°C, and the pressure during pressing is 0.2 MPa. The light source and irradiation amount of the irradiation part 40 are the same as those in No.1; No.4: There is no crimping part 9 in Figure 2. The temperature of the heating member 93 is 50°C, and the wavelength and irradiation amount of the light source 41 are the same as those in No.1.

[0364] -Evaluation criteria for fixing property- ◎: Fixing rate is 85% or more ○: Fixing rate is 75% or more and less than 85% △: Fixing rate is 60% or more and less than 75% ×: Fixing rate is less than 60%.

[0365] [Resistance to document offset] Using the developers 1 to 30 and comparative developers 1 to 9 obtained above, prints were made under normal temperature and normal humidity environment (temperature 20°C, relative humidity 50%RH). On one side was the developer, and on the other side was paper (CF paper, basis weight: 80 g / m 2 ) placed between a pair of parallel plate (aluminum) electrodes. The developer was arranged while being slid by magnetic force. The gap between the electrodes was 0.5 mm, and the toner was developed under the conditions where the DC bias and AC bias were such that the toner adhesion amount was 8 g / m 2 . A toner layer was formed on the surface of the above paper and fixed by the fixing device of No.1 to obtain 10 prints (image formation). The wavelength of the ultraviolet light irradiated from the irradiation part 40 was 365 nm (light source: LED light source with an emission wavelength of 365 nm ± 10 nm), and the irradiation amount was 12 J / cm 2 .

[0366] Next, on a marble table, the 10 output prints were aligned and placed as they were, and for the overlapped part, 19.6 kPa (200 g / cm 2We placed weights so that the pressure of ) was applied. After leaving it in an environment of 35°C and 50% RH for 1 day in this state, we peeled off the overlapped printed materials and evaluated the anti-document offset property according to the following criteria for the image defects on the toner image and the degree of back transfer to the non-image area on the back of the paper, and used it as an index for image storability. A rank of 4 or higher was considered a pass. The evaluation results are shown in Table 3 below: 5: No image defects or image transfer are observed in both the image area and the non-image area 4: There are no image defects in the image area, but slight image transfer is observed in the non-image area on the back of the paper 3: There are almost no image defects in the image area and it is at an acceptable level, but slight transfer is observed in the non-image area on the back of the paper 2: White spots of image defects occur in some parts of the image area, and transfer to the non-image area on the back of the paper is also observed in some parts 1: The fixed image in the image area is peeled off, there are severe image defects, and obvious image transfer is observed in the non-image area on the back of the paper.

[0367] [Color reproducibility evaluation] Regarding the color reproducibility of the images of the examples and comparative examples obtained in the above fixing property test, it was evaluated according to the following evaluation criteria by visual evaluation by 10 monitors. Specifically, as a sample for evaluation comparison, a toner in which all of Polymer 1 was changed to a styrene-acrylic resin was prepared. Using this, a developer was prepared in the same manner as above, developed in the same manner as image formation in the above fixing property test, and fixed using the following fixing device No. 5.

[0368] Fixing device No. 5: It has a pressure bonding part 9 in Fig. 2, the temperature of the pressure applying member 91 is 150°C, the pressure during pressing is 0.2 MPa, and no light irradiation is performed.

[0369] We showed the evaluation comparison sample and the images obtained in the above examples and comparative examples to 10 monitors in turn and asked if the colors of the two images were clearly different. The judgment results according to the following evaluation criteria for color reproducibility are shown in Table 3 below.

[0370] -Evaluation criteria for color reproducibility- ◎: Less than 2 people answered that they were clearly different. ○: 3 - 4 people answered that they were clearly different. △: 5 - 7 people answered that they were clearly different. ×: 8 or more people answered that they were clearly different.

[0371]

Table 1 - 1

[0372]

Table 1 - 2

[0373]

Table 2

[0374]

Table 3

[0375] As is clear from Table 2 above, it was confirmed that the polymers of each example containing the specific structural unit represented by the above general formula (1) were fluidized by light irradiation and reversibly non - fluidized. In the polymers of Comparative Examples 1 - 8 that do not have the above - mentioned specific structural unit, fluidization by light irradiation was less likely to occur compared with the polymers of each example. Also, in the azobenzene derivative of Comparative Example 9, reversible non - fluidization after fluidization was not confirmed.

[0376] Also, as shown in Table 3 above, the toners using the polymers prepared in each example were all capable of fixing by light irradiation and showed high fixing property, high image stability and excellent color reproducibility. On the other hand, the toners using the polymers prepared in Comparative Examples 1 - 8 had insufficient fixing property and image stability. Also, it was found that the toner using the azobenzene derivative of Comparative Example 9 had low fixing property and image stability and low color reproducibility.

Explanation of Symbols

[0377] 1 Photoconductor, 2 Charger, 3 Exposure unit, 4 Developing unit, 5 Transfer unit (transfer roller), 7 Paper conveyance system, 8 Cleaning unit, 9 Pressing unit, 10 Image forming unit, 11 Paper feeding unit, 12 Conveying roller, 13 Conveying belt, 14 Paper discharging unit, 15 Manual paper feeding unit, 16 Tray, 17 Thermohygrometer, 20 Image processing unit, 24 Paper reversing unit, 40 Irradiation unit, 41 Light source, 71 Image reading device, 72 Automatic document feeder, 85 Blade, 90 Control unit, 91, 92 Pressing members, 93 Heating member, 100 Image forming apparatus, d Document, S Recording paper.

Claims

1. A photoreactive polymer that contains a structural unit represented by the following general formula (2), fluidizes upon light irradiation, and reversibly becomes non-fluidized: 【Chemical 1】 In the general formula (2), r1 is a hydrogen atom or a methyl group, A is represented by any one of the following general formulas (1-1) to (1-4): [Chemical 2] where, * represents a bonding point, G is a divalent group, Z1 and Z2 are CH or N, Z1 ≠ Z2, R1 is an aromatic hydrocarbon group having a substituent Ra selected from the group consisting of an alkyl group, an alkoxy group, and a halogen atom at two ortho positions with respect to Z1, R2 is a substituted or unsubstituted aromatic heterocyclic group.

2. The above-mentioned R ａ The polymer according to claim 1, wherein R is an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a halogen atom.

3. The polymer according to claim 1 or 2, wherein G is an alkylene group having 1 to 18 carbon atoms or an oxyalkylene group having 1 to 18 carbon atoms.

4. Said R ２ is a carbon atom constituting the ring structure of the aromatic heterocyclic group, which is bonded adjacent to the carbon atom bonded to the carbon atom or nitrogen atom of said Z ２ and has at least one carbon atom bonded to a hydrogen atom, and is the polymer according to any one of claims 1 to 3.

5. wherein A is represented by the general formula (1-1) or the general formula (1-2), and R ２ is represented by the following formula, and is the polymer according to any one of claims 1 to 4: [Chemical Formula 3] In the formula, R ｃ is a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or an alkoxy group having 1 to 18 carbon atoms.

6. The polymer according to any one of claims 1 to 5, wherein the number average molecular weight Mn is 3000 or more.

7. The polymer according to any one of claims 1 to 6, further comprising another structural unit derived from a monomer having a vinyl polymerizable group.

8. The polymer according to claim 7, wherein the monomer having a vinyl polymerizable group is at least one selected from the group consisting of a styrene derivative, a (meth)acrylic acid derivative, and an olefin derivative.

9. Represented by the following general formula (3): 【Chemical Formula 4】 where, α is, independently of each other, a polymer block containing a structural unit represented by the general formula (2), β is, independently of each other, a polymer block containing a structural unit other than the structural unit represented by the general formula (2), and the polymer according to any one of claims 1 to 8.

10. The number average molecular weight of α is 1000 or more, The number average molecular weight of β is 1000 or more, The polymer according to claim 9, wherein the total number average molecular weight is 3000 or more.

11. The polymer according to claim 9 or 10, wherein β is a polymer block containing at least one structural unit selected from the group consisting of a styrene derivative, a (meth)acrylic acid derivative, and an olefin derivative.

12. The polymer according to any one of claims 1 to 11, wherein the wavelength of the light in the light irradiation is 280 nm or more and 480 nm or less.

13. A toner containing the photoreactive polymer according to any one of claims 1 to 12 as a binder resin.

14. The toner according to claim 13, further comprising another binder resin.

15. The toner according to claim 14, wherein the other binder resin contains at least one selected from the group consisting of a styrene acrylic resin and a polyester resin.

16. An image forming method comprising: a step of forming a toner image composed of the toner according to any one of claims 13 to 15 on a recording medium; and a step of irradiating the toner image with light to soften the toner image.

17. The image forming method according to claim 16, wherein the wavelength of the light is 280 nm or more and 480 nm or less.

18. The image forming method according to claim 16 or 17, further comprising a step of pressing the toner image.

19. The image forming method according to claim 18, further comprising a step of further heating the toner image in the pressing step.

20. The image forming method according to any one of claims 16 to 19, wherein in the step of irradiating the toner image with light to soften the toner image, the toner image is heated together with the light irradiation.

21. A photo-responsive adhesive comprising the photo-responsive polymer according to any one of claims 1 to 12.

22. A photo-switching material comprising the photo-responsive polymer according to any one of claims 1 to 12.

Images