Photoresponsive compound, adhesive, switching material and toner using the same, and image forming method using the toner

Abstract

To provide a compound that is fluidized by light irradiation and reversibly non-fluidized, and is not significantly colored.SOLUTION: A compound fluidized by light irradiation and reversibly non-fluidized is represented by the general formula (1) in the figure. In the general formula (1), Ar1 and Ar2 each independently represent an aromatic hydrocarbon group optionally having a substituent, or an aromatic heterocyclic group optionally having a substituent; and Y, Z1 and Z2 each independently represent a hydrogen atom or a lower alkyl group.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a photoresponsive compound, an adhesive using the same, a switching material and a toner, and an image forming method using the toner.

Background Art

[0002] In the context of energy conservation and the expansion of compatible media, a system for fixing toner with energy different from heat has attracted attention. Among them, the fixing of toner by light has been attracting attention, and a developer that softens by light (photo-fusible toner) has also been reported.

[0003] The azobenzene compounds used in Patent Documents 1 and 2 are well-known compounds as photo-phase transition materials that absorb light and undergo a phase transition from a solid to a liquid. The photo-phase transition of the azobenzene compound is considered to occur due to the collapse of the crystal structure by trans-cis isomerization.

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, the azobenzene compounds described in Patent Documents 1 and 2 have strong absorption due to n-π * transition in the long wavelength region and exhibit orange color. This color causes problems when used as a colorant such as toner because it affects color reproducibility.

[0006] In addition, the toner containing the azobenzene compound described in Patent Documents 1 and 2 has a problem in color reproduction as a toner because the azobenzene compound has an orange color. Further, the toner that is fixed by an external stimulus other than heat fixing has a problem of low productivity because the softening rate required for fixing is not sufficient.

[0007] On the other hand, according to the research of the present inventors, an azomethine compound having a structure in which a benzene ring is connected by an azomethine group has a problem that even when it changes from a trans form to a cis form by light irradiation, the reverse reaction is too fast and it is insufficient to maintain the softening state required for fixing when applied to a toner.

[0008] Therefore, an object of the present invention is to provide a compound that is fluidized by light irradiation, reversibly non-fluidized, and has no significant coloring.

[0009] Another object of the present invention is to provide a toner containing the above compound that does not affect the desired color reproduction even when mixed with a colorant, has a significantly improved softening rate, and has good fixability by maintaining the softening state required for fixing.

[0010] Another object of the present invention is to provide an adhesive and a switching material using the above compound having good adhesiveness and switching properties.

[0011] Yet another object of the present invention is to provide an image forming method excellent in color reproducibility and fixability of an image using the above toner.

Means for Solving the Problems

[0012] In view of the above problems, the present inventors have intensively studied. As a result, considering photo-melting and achieving desired color reproduction when used as a coloring material such as toner, a compound of the above general formula (1) having an absorption at a wavelength of 300 nm to 400 nm and having a substantially colorless propenimine structure (also referred to as a propenimine compound) was found. That is, it has been found that the above propenimine compound is fluidized by light irradiation, reversibly non-fluidized, and becomes a photo-responsive compound with no significant coloring. Furthermore, by incorporating the above propenimine compound into toner, it has been found that the softening rate is significantly improved without affecting the color reproducibility of the toner, and good fixability is achieved by maintaining the softened state required for fixing, thus completing the present invention.

[0013] That is, the present invention is achieved by the photo-responsive compounds shown in the following 1 to 13, adhesives, switching materials, and toners using the same, and an image forming method using this toner.

[0014] 1. A compound represented by the following general formula (1) that is fluidized by light irradiation and reversibly non-fluidized:

[0015]

Chemical formula

[0016] In the above general formula (1), Ar1 and Ar2 each independently represent an aromatic hydrocarbon group that may have a substituent (a) or an aromatic heterocyclic group that may have a substituent (b). Y, Z1, and Z2 each independently represent a hydrogen atom or a lower alkyl group.

[0017] 2. The compound according to 1 above, wherein the substituents (a) and (b) are each independently an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, an aromatic hydrocarbon group that may have a substituent (c), or an aromatic heterocyclic group that may have a substituent (d).

[0018] 3. The compound according to 2 above, wherein the substituents (c) and (d) are each independently an alkyl group having 1 to 8 carbon atoms or an alkoxy group having 1 to 8 carbon atoms.

[0019] 4. The compound according to any one of 1 to 3 above, wherein the lower alkyl group is an alkyl group having 1 to 2 carbon atoms.

[0020] 5. A toner comprising the compound according to any one of 1 to 4 above.

[0021] 6. The toner according to 5 above, further comprising a binder resin.

[0022] 7. The toner according to 6 above, wherein the binder resin contains at least one selected from the group consisting of styrene-acrylic resins and polyester resins.

[0023] 8. The toner according to any one of 5 to 7 above, further comprising a colorant.

[0024] 9. A step of forming an image on a recording medium using the toner comprising the compound according to any one of 1 to 4 above, a step of irradiating the image formed on the recording medium with light in a wavelength region of 280 to 420 nm, a step of fixing the image, and an image forming method comprising the above steps.

[0025] 10. The image forming method according to 9 above, wherein the step of fixing the image on the recording medium includes a step of pressing the recording medium on which the image is formed with a pressing member.

[0026] 11. The image forming method according to 10 above, wherein the temperature of the pressing member is 30°C or higher and 100°C or lower.

[0027] 12. A photo-responsive adhesive using the compound according to any one of 1 to 4 above.

[0028] 13. A photoswitching material using the compound according to any one of the above items 1 to 4.

Advantages of the Invention

[0029] According to the present invention, it is possible to reversibly fluidize and non-fluidize by light irradiation, control the reaction rate from the cis form to the trans form, create a sufficient softening state, and provide a compound without significant coloring.

[0030] Further, according to the present invention, even when mixed with a colorant, it does not affect the desired color reproduction, significantly improves the softening rate of the toner by light irradiation, and can improve the image fixing property by maintaining the softening state required for fixing. A toner containing the above compound and an image forming method using this toner can be provided.

Brief Description of the Drawings

[0031]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0032] The present invention is a compound represented by the following general formula (1) that fluidizes by light irradiation and reversibly non-fluidizes.

[0033]

Chemical formula

[0034] In the general formula (1), Ar1 and Ar2 each independently represent an aromatic hydrocarbon group which may have a substituent (a) or an aromatic heterocyclic group which may have a substituent (b). Y, Z1 and Z2 each independently represent a hydrogen atom or a lower alkyl group.

[0035] The propenimine compound represented by the above general formula (1) is fluidized by light irradiation, reversibly non-fluidized, and when applied to a toner, it does not affect the desired color reproduction even when mixed with a colorant. As a result, the softening rate of the toner by light irradiation is significantly improved, and the fixability of the image can be improved by maintaining the softened state necessary for fixing.

[0036] Although the details of why the above effects can be obtained by the above compounds of the present invention and the toner containing the same are unclear, the following mechanism is conceivable. The following mechanism is based on speculation, and the present invention is not limited to the following mechanism. In the following description, the compound represented by the above general formula (1) is also referred to as a "propenimine compound".

[0037] The azobenzene compounds described in Patent Documents 1 and 2 have strong absorption due to n-π * transition in the long wavelength region, and when added to a toner, the desired color reproduction cannot be achieved when mixed with a colorant. On the other hand, the propenimine compound of the present invention can weaken the strong absorption due to n-π * transition existing in the long wavelength region, so that the desired color reproduction can be realized even when mixed with a colorant.

[0038] In addition, a compound that reversibly fluidizes and non-fluidizes with photoisomerization is considered to be able to induce a phase transition change, that is, a fluidization phenomenon, when the non-fluid trans form (E) is irradiated with light and isomerizes to the cis form (Z), and the regular structure collapses. Also, it is considered that when the cis form (Z) returns to the trans form (E), a regular structure is formed again, and a non-fluidization phenomenon can be induced.

[0039] Therefore, in order to induce the phenomenon of fluidization by light irradiation and reversibly non-fluidization, it is considered that many trans-forms (E) need to isomerize to cis-forms (Z) during fluidization. However, generally, azomethine compounds are known to have a faster reverse reaction rate of Z→E reaction (non-fluidization reaction) compared to azobenzene compounds. According to the research of the present inventors, in azomethine compounds with benzene rings introduced at both ends, it was predicted that it would be disadvantageous to induce the phenomenon of fluidization by light irradiation and reversibly non-fluidization. Also, the fact that the Z→E reaction rate is fast means that the energy barrier in the Z→E reaction is low, so it is considered that it quickly returns to the trans-form (E).

[0040] Therefore, in the present invention, it is considered that the Z→E reaction rate can be controlled by controlling the energy barrier in the Z→E reaction. By connecting a vinylene group with a high energy barrier and a slow Z→E reaction rate to an azomethine group with a low energy barrier, the inventors successfully controlled the Z→E reaction rate.

[0041] Also, the photophase transition of the azomethine compound is considered to occur by the collapse of the crystal structure due to trans-cis isomerization, similar to the azobenzene compound described above. Generally, azomethine compounds have strong intermolecular π-π interactions, so the photophase transition occurs only on the outermost surface of the crystal structure. In contrast, the propenimine compound of the present invention has an aromatic ring substituted with an alkyl group or an alkoxy group. The propenimine compound of the present invention forms a specific crystal structure in which an isotropically disordered structure coexists with a periodically structured structure dominated by π-π interactions due to the thermal motion of alkyl groups or alkoxy groups. Therefore, when the cis-trans isomerization reaction proceeds locally and the π-π interaction of the propenimine moiety is reduced, isotropic melting occurs chainwise throughout the system. Therefore, it is considered that the trans-cis isomerization becomes more likely to proceed and fluidization is more likely to occur.

[0042] For these reasons, it is considered that the propenimine compound of the present invention can induce a phenomenon of fluidization accompanied by photoisomerization while being colorless and reversibly non-fluidizing. By incorporating the compound into a toner, a toner that can be fixed by light irradiation and has high color reproducibility and an image forming method using the same can be obtained. Further, by irradiating the propenimine compound of the present invention with light to cause isomerization, a reversible fluidization and non-fluidization phenomenon can be induced, and it can also be used as an adhesive and a photoswitching material.

[0043] In addition, the fluidization in the present invention refers to a state of being deformed without an external force or with a small external force.

[0044] Hereinafter, preferred embodiments of the present invention will be described. In this specification, "X~Y" indicating a range means "X or more and Y or less". Also, in this specification, unless otherwise specified, measurements of operations and physical properties are carried out under the conditions of room temperature (20~25°C) / relative humidity 40~50%RH.

[0045] <Propenimine compound> The propenimine compound of the present invention is a compound represented by the following general formula (1) that is fluidized by light irradiation and reversibly non-fluidized. As shown in the above mechanism, the propenimine compound of the present invention can induce a phenomenon of fluidization accompanied by photoisomerization while being colorless and reversibly non-fluidizing. By incorporating the compound into a toner, a toner that can be fixed by light irradiation and has high color reproducibility can be obtained.

[0046]

Chemical formula

[0047] In general formula (1), Ar1 and Ar2 each independently represent an aromatic hydrocarbon group which may have a substituent (a) or an aromatic heterocyclic group which may have a substituent (b). The aromatic hydrocarbon group is a residue obtained by removing hydrogen from an aromatic hydrocarbon. The number of its carbon atoms is preferably 6 to 30, more preferably 6 to 20, from the viewpoints of exhibiting aromaticity and effectively expressing the effects of the invention. The aromatic heterocyclic group is a monocyclic or polycyclic (condensed) heterocyclic group exhibiting aromaticity and containing a hetero atom in addition to a carbon atom as a ring-constituting atom. Examples of the hetero atom include atoms other than a carbon atom and a hydrogen atom, such as an oxygen atom, a sulfur atom, a nitrogen atom, a phosphorus atom, a boron atom, an antimony atom, an arsenic atom, a bismuth atom, a selenium atom, a silicon atom, a tellurium atom, a tin atom, and a germanium atom. From the viewpoints of exhibiting aromaticity and effectively expressing the effects of the invention, an oxygen atom, a sulfur atom, and a nitrogen atom are preferable. The number of the hetero atoms may be 1 or more, and preferably 1 to 3, from the viewpoint of more effectively expressing the effects of the invention.

[0048] These aromatic hydrocarbon groups and aromatic heterocyclic groups (collectively also simply referred to as "aromatic ring") are not particularly limited, and examples thereof include a benzene ring group, a naphthalene ring group, a thiophene ring group, a furan ring group, a pyrrole ring group, a pyrazole ring group, an imidazole ring group, and a thiazole ring group.

[0049] More specifically, examples of the aromatic hydrocarbon group include a benzene ring group (phenyl group), a biphenyl ring group, a naphthalene ring group, an azulene ring group, an anthracene ring group, a phenanthrene ring group, a pyrene ring group, a chrysene ring group, a naphthacene ring group, a triphenylene ring group, an o-terphenyl ring group, an m-terphenyl ring group, a p-terphenyl ring group, an acenaphthene ring group, a coronene ring group, a fluorene ring group, a fluoranthene ring group, a pentacene ring group, a perylene ring group, a pentaphene ring group, a picene ring group, a pyranthrene ring group, and an anthraanthracene ring group.

[0050] Examples of the aromatic heterocyclic group include a furan ring group (furyl group), a thiophene ring group, a pyridine ring group (pyridyl group), a pyridazine ring group, a pyrimidine ring group, a pyrazine ring group, a pyrrole ring group (pyrrolyl group), a triazine ring group, an oxazole ring group (oxazolyl group), an oxadiazole ring group, a triazole ring group, an imidazole ring group (imidazolyl group), a pyrazole ring group, a thiazole ring group (thiazolyl group), an indole ring group, a benzimidazole ring group, a benzothiazole ring group, a benzoxazole ring group, a quinoxaline ring group, a quinazoline ring group, a phthalazine ring group, a benzofuran ring group, a dibenzofuran ring group, a benzothiophene ring group, a dibenzothiophene ring group, a carbazole ring group, and the like.

[0051] These aromatic rings (aromatic hydrocarbon groups and aromatic heterocyclic groups) may have the substituents (a) and (b). Specific examples of the substituents (a) and (b) include, for example, an alkyl group having 1 to 24 carbon atoms (methyl group, ethyl group, propyl group, isopropyl group, t-butyl group, pentyl group, hexyl group, octyl group, decyl group, dodecyl group, octadecyl group, cyclohexyl group, cyclopentyl group, etc.); an alkoxy group having 1 to 24 carbon atoms (methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group, decyloxy group, dodecyloxy group, octadecyloxy group, cyclohexyloxy group, cyclopentyloxy group, etc.); an aromatic hydrocarbon group which may have a substituent (c); an aromatic heterocyclic group which may have a substituent (d); a halogen atom (chlorine atom, bromine atom, iodine atom, fluorine atom, etc.), an aryloxy group (phenoxy group, etc.), an alkoxycarbonyl group (methyloxycarbonyl group, ethyloxycarbonyl group, etc.), a sulfonamide group (methanesulfonamide group, ethanesulfonamide group, butanesulfonamide group, hexanesulfonamide group, cyclohexanesulfonamide group, benzenesulfonamide group, etc.), a sulfamoyl group (aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, phenylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), a carbamoyl group (aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, etc.), an amide group (acetamide group, propionamide group, benzamide group, etc.), a sulfonyl group (methylsulfonyl group, ethylsulfonyl group, phenylsulfonyl group, etc.), an amino group (amino group, ethylamino group, dimethylamino group, etc.), a cyano group, a carboxyl group, a hydroxyl group, etc.

[0052] Moreover, the substituents (a) and (b) are each independently preferably an alkyl group having 1 to 18 carbon atoms, preferably 4 to 12 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, preferably 4 to 12 carbon atoms, an aromatic hydrocarbon group which may have a substituent (c), or an aromatic heterocyclic group which may have a substituent (d). When the number of carbon atoms of the alkyl group and alkoxy group of the substituents (a) and (b) is within the above range, the compound does not become a wax-like state, and when incorporated into the toner, the compatibility with the binder resin is good, which is preferable. In addition, by making the substituents (a) and (b) an alkyl group or an alkoxy group, it is excellent in that the intermolecular π-π interaction can be further reduced by thermal motility. Further, when an aromatic ring (aromatic hydrocarbon group or aromatic heterocyclic group) is introduced into the substituents (a) and (b), in the case of an unsubstituted aromatic ring, the intermolecular π-π interaction is strong, and it is difficult to isomerize and disrupt the molecular arrangement, so it is difficult to fluidize and requires high light irradiation energy. However, when incorporated into the toner, the light irradiation energy can be kept low during fixing, and by using pressure heating in combination, excellent softening speed and image fixing property can be exhibited.

[0053] Furthermore, by substituting the above aromatic ring with an alkyl group or an alkoxy group having thermal motility, the propenimine compound having such a substituent can form a specific crystal structure in which an isotropically disordered structure coexists due to the thermal motility of the alkyl group or alkoxy group in a periodic structure dominated by π-π interaction. Therefore, when the cis-trans isomerization reaction proceeds locally and the π-π interaction of the propenimine part is reduced, isotropic melting occurs chainwise throughout the system. Therefore, the trans-cis isomerization of the propenimine compound more easily proceeds and fluidization more easily occurs. Therefore, when the propenimine compound having such a substituent is incorporated into the toner, at the time of fixing, even without using pressure heating in combination and even with low light irradiation energy, an appropriate softening speed and excellent image fixing property can be exhibited.

[0054] Further, the aromatic rings (aromatic hydrocarbon group and aromatic heterocyclic group) of the substituents (a) and (b) may have the substituents (c) and (d). Preferred examples of the substituents (c) and (d) include an alkyl group having 1 to 8 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms (methyl group, ethyl group, propyl group, isopropyl group, t-butyl group, pentyl group, hexyl group, heptyl group, octyl group, cyclopentyl group, cyclohexyl group, etc.); preferably an alkoxy group having 1 to 8 carbon atoms, more preferably an alkoxy group having 1 to 3 carbon atoms (methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group, cyclopentyloxy group, cyclohexyloxy group, etc.). When the number of carbon atoms of the alkyl group and alkoxy group of the substituents (c) and (d) is 1 to 8, the molecular weight of the propenimine compound will not become too large. Therefore, by using the compound as a toner, good compatibility and solubility with the binder resin can be obtained. Further, the reason for introducing an alkyl group or an alkoxy group as the substituents (c) and (d) is as follows. That is, as the substituents (c) and (d), bulky substituents such as a halogen atom, a nitro group, a cyano group, and a dialkylamino group will be disadvantageous to the compatibility with the binder resin when the propenimine compound having such a substituent is used as a toner, and it is considered that electron-withdrawing substituents such as a halogen atom, a nitro group, and a cyano group will have an adverse effect on the photoisomerization reaction. Therefore, from the viewpoints of being a low-bulk substituent that does not cause such problems, being an electron-donating substituent, and facilitating the production of the propenimine compound, it is preferable to introduce an alkyl group or an alkoxy group having a small number of carbon atoms. Thereby, when the propenimine compound having such a substituent is used as a toner, it is excellent in compatibility with the binder resin, and since an electron-donating substituent is introduced, it can be easily fluidized by light irradiation and reversibly non-fluidized.

[0055] The number of the substituents (a) and (b) other than the hydrogen atom introduced into the aromatic ring is preferably 1 to 5 in each case. However, from the viewpoint that the melting point decreases as the number of substituents increases and the heat-resistant storage property of the toner is improved, the number of the substituents (a) and (b) other than the hydrogen atom is more preferably 1 to 2 in each case.

[0056] In the general formula (1), Y, Z1 and Z2 are each independently a hydrogen atom or a lower alkyl group. This is because in the general formula (1), introducing a large substituent at the positions of Y, Z1 and Z2 is sterically difficult in synthesis, and even if the synthesis is possible, it becomes a steric hindrance when photoisomerization occurs. Therefore, it is preferable not to introduce a large substituent. By introducing a small substituent such as a hydrogen atom or a lower alkyl group at the positions of Y, Z1 and Z2, it is excellent in that the above problems are less likely to occur. Here, the lower alkyl group is a linear or branched alkyl group having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms (methyl group, ethyl group, propyl group, isopropyl group, t-butyl group, pentyl group, hexyl group, etc.). If the substituent is not too large, there is no steric hindrance in synthesis and it can be easily synthesized, it is easy to secure the free volume necessary for the cis-trans isomerization reaction, and steric hindrance during photoisomerization is also less likely to occur, and the above problems are less likely to occur. From such a viewpoint, it is more preferably an alkyl group having 1 to 2 carbon atoms.

[0057] At least one, preferably 1 to 2 of Y, Z1 and Z2 are a linear or branched alkyl group having 1 to 6 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, more preferably an alkyl group having 1 to 2 carbon atoms. This is to induce the generation of lattice defects, the expression of free volume, the reduction of intermolecular π-π interaction, etc., which act advantageously on cis-trans isomerization.

[0058] As the propenimine compound of the present invention, in the general formula (1), an aromatic ring A (aromatic hydrocarbon group or aromatic heterocyclic group) as shown in Tables 1-1 to 1-5 below, and substituents (a) and (b) of each aromatic ring, R1 to R 10, compounds 1 to 57 and the like in which X (hetero group), Y, Z1, and Z2 are appropriately selected can be mentioned. Further, Table 1-5 shows Comparative Compounds 1 and 2 which are azobenzene compounds and stilbene compounds used in the examples of the patent document.

[0059]

Table 1-1

[0060]

Table 1-2

[0061]

Table 1-3

[0062]

Table 1-4

[0063]

Table 1-5

[0064] As described above, the alkyl group and alkoxy group of the substituent of the aromatic ring (the above R1 to R 10 ) may be either linear or branched.

[0065] The molecular weight of the compound represented by the general formula (1) of the present invention is not particularly limited, but is preferably 100 or more and 1000 or less, more preferably 200 or more and 850 or less, still more preferably 300 or more and 750 or less, and even more preferably 500 or more and 600 or less. Note that the compound represented by the general formula (1) of the present invention does not contain a polymer. In a preferred embodiment, the compound represented by the general formula (1) is composed without including a repeating unit. In a preferred embodiment, the propenimine compound represented by the general formula (1) is not obtained by polymerizing a monomer containing a polymerizable group.

[0066] When fluidizing the propenimine compound of the present invention by light irradiation, the wavelength of the irradiation light is preferably in the range of 280 nm or more and 420 nm or less, more preferably in the range of 300 nm or more and 400 nm or less, and even more preferably in the range of 330 nm or more and 390 nm or less. Within this range, light in the ultraviolet region is mainly well absorbed, the photo-melting property is improved, and the fixing property is improved when applied to a toner. Examples of the light source suitable for irradiating the ultraviolet light include a light-emitting diode (LED), a laser light source, and the like. Further, when fluidizing, in addition to light irradiation, heat or pressure may be applied to promote fluidization. By applying heat or pressure, the compound can be fluidized with a smaller amount of light irradiation. Therefore, by containing the propenimine compound in a toner, fixing by light irradiation at the above wavelength becomes possible, and a toner with high color reproducibility can be obtained even when a colorant is mixed. Note that the above wavelength range is in the ultraviolet region, but also includes a visible light region close to ultraviolet light. This is because the propenimine compound can be fluidized under the following irradiation conditions even with irradiation light in the visible light region close to ultraviolet light.

[0067] The irradiation amount of the irradiation light for fluidizing the propenimine compound is preferably in the range of 0.1 J / cm 2 or more and 200 J / cm 2 or less, more preferably in the range of 0.5 J / cm 2 or more and 100 J / cm 2 or less, and even more preferably 1.0 J / cm 250 J / cm or more 2 It is within the following range. When the light irradiation amount is 0.1 J / cm 2 or more of energy, the reaction from E to Z occurs over the energy barrier, the photo-melting property improves, and the propenimine compound can be fluidized. On the other hand, when the light irradiation amount is 200 J / cm 2 or less, the energy is not too large, and the propenimine compound can be fluidized well without being broken.

[0068] On the other hand, when reversibly non-fluidizing the propenimine compound, as shown in the examples, external forces (external energy) such as light, heat, and pressurization may not be applied, but light irradiation as shown below may be performed. When forming a toner using the propenimine compound, from the viewpoints of downsizing, simplification, energy saving of the image forming apparatus, and prevention of global warming by reducing exhaust heat and CO2 emissions, it is preferable to reversibly non-fluidize without applying external energy or external forces such as light irradiation, heating, and pressurization.

[0069] When irradiating light when reversibly non-fluidizing the propenimine compound, the wavelength of the irradiation light is preferably longer than the irradiation light when fluidizing, for example, within the range of 400 nm or more and 800 nm or less, preferably within the range of more than 420 nm and 800 nm or less, more preferably within the range of 430 nm or more and 730 nm or less, and still more preferably within the range of 450 nm or more and 650 nm or less. Within this range, by mainly absorbing light in the visible light region well, the photocuring property improves, and the fixing property improves when applied to the toner. Further, by irradiating the irradiation light with the above wavelength, it is possible to non-fluidize without applying heat or pressure. Therefore, by including the propenimine compound in the toner, the toner image on the recording paper can be more reliably solidified, the fixing property of the toner image to the recording paper can be further improved, and a toner with high color reproducibility can be obtained.

[0070] When irradiating light when reversibly non-fluidizing the propenimine compound, the irradiation amount of visible light is preferably 0.1 J / cm 2200 J / cm or more 2 within the following range, more preferably 0.5 J / cm 2 100 J / cm or more 2 within the following range, even more preferably 1.0 J / cm 2 50 J / cm or more 2 within the following range. If the light irradiation amount is 0.1 J / cm 2 or more, the reaction of Z→E (non-fluidization) occurs over the energy barrier, and the propenimine compound can be non-fluidized. On the other hand, if the light irradiation amount is 200 J / cm 2 or less, the energy is not too large, and the propenimine compound can be favorably non-fluidized and solidified (fixed, adhered, etc.) without being broken.

[0071] In addition, as a means for reversibly non-fluidizing the propenimine compound, as described above, without applying external energy or external force such as light irradiation, heating, or pressurization, it is most preferable to leave it at room temperature (non-heated; in the range of 25 ± 15 °C), that is, place it in a natural environment. At this time, it is good to place it in a dark place, but it may also receive visible light such as natural light or fluorescent light. When non-fluidizing using some means, it is preferable to use the means by light irradiation. This means can reversibly non-fluidize the propenimine compound in a short time, and since the image forming apparatus, particularly the fixing apparatus, can be made lightweight and compact, it is advantageous for toner fixing.

[0072] The method for synthesizing the propenimine compound of the present invention is not particularly limited, and a conventionally known synthesis method can be applied. For example, taking the compound No. 5 in Table 1-1 of the above general formula (1) as an example, it can be synthesized by the following method.

[0073]

Chemical formula

[0074] In ethanol (hereinafter also referred to as EtOH), 3-(4-(hexyloxy)phenyl)acetylaldehyde (raw material 1) as a raw material and 4-hexyloxyaniline (raw material 2) are stirred and heated to reflux. After confirming the disappearance of 4-hexyloxyaniline, the internal temperature is lowered to room temperature, and water is added to the reaction solution to stop the reaction. The target product is extracted with ethyl acetate, washed with water, the ethyl acetate solution is dried, and then concentrated to obtain crude crystals of Compound No. 5. This can be recrystallized with EtOH to obtain Compound No. 5 as the target product.

[0075] Propeneimine compounds other than Compound No. 5 can also be synthesized by the same method as the synthesis of Compound No. 5 shown above. Specifically, 3-(4-(hexyloxy)phenyl)acetylaldehyde (raw material 1) and 4-hexyloxyaniline (raw material 2) are changed to the acetylaldehyde (raw material 1) and aniline (raw material 2) shown in Tables 2-1 to 2-3 of the examples, respectively. Compounds 1 to 4 and 6 to 57 as the target products can be synthesized by the same method as the synthesis of Compound No. 5 except for this.

[0076] The propeneimine compounds of the present invention can be used alone or in combination of two or more.

[0077] [Composition of Toner] The toner of the present invention contains the above-mentioned colorless propeneimine compound that is fluidized by light irradiation and reversibly non-fluidized. By containing the propeneimine compound in the toner, even when mixed with a colorant, it does not affect the desired color reproduction, and the softening rate of the toner by light irradiation is significantly improved. By maintaining the softened state necessary for fixing, the fixability of the image can be improved. Here, the toner refers to toner mother particles or an aggregate of toner particles. The toner particles are preferably those obtained by adding an external additive to the toner mother particles, but the toner mother 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 toner mother particles, toner particles, and toner, they are simply referred to as "toner".

[0078] [Binder Resin] In addition to the propenimine compound, the toner of the present invention preferably further contains a binder resin. It is generally known that toner particles having a substantially uniform particle size and shape can be produced by using the emulsion aggregation method described later as a method for producing toner. Even if the binder resin is not used and only the propenimine compound alone or other additives such as a colorant and a release agent are added, toner can be produced (see Example 83 in Table 3-2). However, by using the propenimine compound and the binder resin in combination, it is possible to produce toner particles having a substantially uniform particle size and shape by using salting out in the emulsion aggregation method. Therefore, the toner containing the propenimine compound and the binder resin can be easily applied by an electrophotographic toner.

[0079] As such a binder resin, resins generally used as binder resins constituting toner can be used without limitation. Specifically, for example, styrene resin, acrylic resin, styrene-acrylic resin, polyester resin, silicone resin, olefin resin, amide resin, and epoxy resin can be mentioned. These binder resins can be used alone or in combination of two or more.

[0080] 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 resin, acrylic resin, styrene-acrylic resin, and polyester resin, and more preferably contains at least one selected from the group consisting of styrene-acrylic resin and polyester resin.

[0081] Hereinafter, the styrene-acrylic resin (also referred to as styrene acrylic resin), which is a preferable binder resin, and the polyester resin will be described.

[0082] (Styrene-Acrylic Resin) The styrene acrylic resin referred to in the present invention is formed by performing polymerization using at least a styrene monomer and a (meth)acrylic acid ester monomer. Here, the styrene monomer includes not only styrene represented by the structural formula CH2=CH-C6H5 but also those having a structure with known side chains or functional groups in the styrene structure.

[0083] Also, the (meth)acrylic acid ester monomer has a functional group having an ester bond in the side chain. Specifically, it includes vinyl ester compounds such as acrylic acid ester monomers represented by CH2=CHCOOR (R is an alkyl group) and methacrylic acid ester monomers represented by CH2=C(CH3)COOR (R is an alkyl group).

[0084] Specific examples of the styrene monomer and the (meth)acrylic acid ester monomer capable of forming the styrene acrylic resin are shown below, but are not limited to those shown below.

[0085] Examples of the styrene monomer 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.

[0086] In addition, typical (meth)acrylic acid ester monomers include the acrylic acid ester monomers and methacrylic acid ester monomers shown below. Examples of acrylic acid ester monomers include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate, phenyl acrylate, etc. Examples of methacrylic acid ester monomers include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, dimethylaminoethyl methacrylate, etc.

[0087] These styrene monomers, acrylic acid ester monomers, or methacrylic acid ester monomers can be used alone or in combination of two or more.

[0088] In addition to the copolymer formed only from the above-mentioned styrene monomers and (meth)acrylic acid ester monomers, some styrene-acrylic copolymers are formed by using general vinyl monomers in combination with these styrene monomers and (meth)acrylic acid ester monomers. The following are examples of vinyl monomers that can be used in combination when forming the styrene-acrylic copolymer referred to in the present invention, but the vinyl monomers that can be used in combination are not limited to those shown below.

[0089] (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, acrylamide, etc.

[0090] 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 dissociable group in the side chain. Specific examples of the ionic dissociable 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 dissociable groups are shown below.

[0091] 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.

[0092] The method for forming the styrene-acrylic resin is not particularly limited, and examples include a method of polymerizing a monomer using a known oil-soluble or water-soluble polymerization initiator. If necessary, for example, a known chain transfer agent such as n-octyl mercaptan may be used.

[0093] When forming the styrene acrylic resin used in the present invention, the contents of the styrene monomer and the acrylate monomer are not particularly limited and can be appropriately adjusted from the viewpoint of controlling the softening temperature and glass transition temperature of the binder resin. Specifically, the content of the styrene monomer is preferably 40% by mass or more and 95% by mass or less, more preferably 50% by mass or more and 90% by mass or less, based on the total monomers. Also, the content of the acrylate monomer is preferably 5% by mass or more and 60% by mass or less, more preferably 10% by mass or more and 50% by mass or less, based on the total monomers.

[0094] 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. Specific examples of the oil-soluble polymerization initiator include azo-based or diazo-based polymerization initiators and peroxide-based polymerization initiators shown below.

[0095] 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, azobisisobutyronitrile, and the like.

[0096] 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, tris-(t-butylperoxy)triazine, and the like.

[0097] When forming styrene-acrylic resin particles by the emulsion polymerization method, a water-soluble radical polymerization initiator can be used. Examples of the water-soluble radical polymerization initiator include persulfates such as potassium persulfate and ammonium persulfate, azobisaminodipropanoic acid salts, azobiscyanovaleric acid and its salts, and hydrogen peroxide.

[0098] The polymerization temperature varies depending on the types of monomers and polymerization initiators used, but it is preferably in the range of 50°C or higher and 100°C or lower, and more preferably in the range of 55°C or higher and 90°C or lower. Also, the polymerization time varies depending on the types of monomers and polymerization initiators used, but it is preferably in the range of, for example, 2 hours or more and 12 hours or less.

[0099] The styrene-acrylic resin particles formed by the emulsion polymerization method can also have a structure of two or more layers 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 polymerization).

[0100] (Polyester resin) The polyester resin is a known 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.

[0101] The valences of the polyvalent carboxylic acid component and the polyvalent alcohol component are preferably 2 to 3, respectively, and particularly preferably 2, respectively. Therefore, a particularly preferred form in which the valences are both 2 (that is, a dicarboxylic acid component and a diol component) will be described.

[0102] 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; etc. Also, lower alkyl esters and acid anhydrides of these can be used. The dicarboxylic acid component may be used alone or in admixture of two or more.

[0103] In addition, polyvalent carboxylic acids having a valence of 3 or more such as trimellitic acid and pyromellitic acid, anhydrides of the above carboxylic acid compounds, or alkyl esters having 1 to 3 carbon atoms can also be used.

[0104] 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 aromatic diols such as alkylene oxide adducts of these bisphenols, such as ethylene oxide adducts and propylene oxide adducts of these bisphenols. Derivatives of these can also be used. The diol component may be used alone or in admixture of two or more thereof.

[0105] 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.

[0106] As catalysts that can be used in the production of polyester resins, there are 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, etc. Specifically, examples of tin compounds include dibutyltin oxide (dibutyltin oxide), tin octylate, tin dioctylate, and salts thereof. Examples of titanium compounds include titanium alkoxides such as tetra-n-butyl titanate (Ti(O-n-Bu)4), tetraisopropyl titanate, tetramethyl titanate, and tetrastearyl titanate; titanium acylates such as polyhydroxy titanium stearate; and titanium chelates such as titanium tetraacetylacetonate, titanium lactate, and titanium triethanolamine, etc. Examples of germanium compounds include germanium dioxide, etc. Further, examples of aluminum compounds include polyaluminum hydroxide, aluminum alkoxide, tributylaluminate, etc. These may be used alone or in combination of two or more.

[0107] The polymerization temperature is not particularly limited, but it is preferably in the range of 70°C or higher and 250°C or lower. Also, the polymerization time is not particularly limited, but it is preferably in the range of 0.5 hours or more and 10 hours or less. During polymerization, the inside of the reaction system may be depressurized as necessary.

[0108] When the toner of the present invention contains the propenimine compound and the binder resin, the content ratio of the propenimine compound to the binder resin depends on the compound type and resin type. From the viewpoints of fixability and color reproducibility, the range of propenimine compound: binder resin = 5:95 to 80:20 (mass ratio) is preferable. Within this range, the photophase transition of the propenimine compound is likely to occur, and the softening rate of the toner due to light irradiation becomes sufficient. From such a viewpoint, the range of propenimine compound: binder resin = 10:90 to 70:30 (mass ratio) is more preferable, and the range of 30:70 to 60:40 (mass ratio) is even more preferable.

[0109] Note that the toner containing the propenimine compound and the binder resin may have a single-layer structure or 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.

[0110] Also, from the viewpoint of heat-resistant storage properties and the like, the glass transition temperature Tg of the binder resin is preferably in the range of 35°C or higher and 70°C or lower, and more preferably in the range of 40°C or higher and 60°C or lower.

[0111] Here, the glass transition temperature Tg can be adjusted by appropriately selecting the monomer species used in the synthesis of the binder resin (binder) based on the glass transition temperature of the amorphous resin alone, adjusting the copolymerization ratio (mass ratio) and molecular weight of the monomers, and the like. For example, taking a styrene-(meth)acrylate copolymer as an example, by increasing the copolymerization ratio (mass ratio) of n-butyl acrylate having a low glass transition temperature with respect to the total monomers, Tg can be lowered, and by increasing the copolymerization ratio (mass ratio) of styrene having a high glass transition temperature, Tg can be raised. Also, taking an amorphous polyester resin as an example, the glass transition temperature can be controlled by adjusting the types of dicarboxylic acid monomers and diol monomers, as well as their mixing ratio (mass ratio). For example, by copolymerizing a trifunctional or higher polyfunctional monomer such as trimellitic acid at an arbitrary copolymerization ratio (mass ratio), crosslinking can occur intramolecularly and intermolecularly, and the glass transition temperature can be raised.

[0112] <Colorant> The toner of the present invention preferably further contains a colorant. The propenimine compound can induce reversible fluidization and non-fluidization phenomena accompanying photoisomerization while being colorless. Therefore, by introducing a desired colorant into the toner together with the propenimine compound, it becomes fixable by light irradiation, and a toner with high color reproducibility of the added colorant can be obtained. As the colorant, generally known dyes and pigments can be used.

[0113] 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, lamp black, etc. Examples of magnetic materials include ferrite, magnetite, etc.

[0114] 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; pigments such as C.I. Pigment Yellow 14, 17, 74, 93, 94, 138, 155, 180, 185.

[0115] Examples of the colorant for obtaining a magenta toner include dyes such as C.I. Solvent Red 1, 49, 52, 58, 63, 111, 122; pigments such as C.I. Pigment Red 5, 48:1, 53:1, 57:1, 122, 139, 144, 149, 166, 177, 178, 222.

[0116] Examples of the colorant for obtaining a cyan toner include dyes such as C.I. Solvent Blue 25, 36, 60, 70, 93, 95; pigments such as C.I. Pigment Blue 1, 7, 15, 15:3, 60, 62, 66, 76.

[0117] For the colorants for obtaining toners of various colors, one or a combination of two or more thereof can be used for each color.

[0118] The content ratio of the colorant is preferably in the range of 0.5% by mass or more and 20% by mass or less in the toner, and more preferably in the range of 2% by mass or more and 10% by mass or less.

[0119] <Release agent> The toner according to the present invention preferably further contains a release agent. By introducing a release agent into the toner together with the propenimine compound, a toner having more excellent fixability can be obtained.

[0120] The release agent to be used is not particularly limited, and various known waxes can be used. Examples of the wax include polyolefin waxes such as low molecular weight polypropylene, polyethylene, or oxidized low molecular weight polypropylene and polyethylene, paraffin waxes, synthetic ester waxes, etc. In particular, since it has a low melting point and low viscosity, it is preferable to use a synthetic ester wax, and it is particularly preferable to use behenyl behenate, glycerin tribehenate, pentaerythritol tetrabehenate, etc. as the synthetic ester wax.

[0121] The content ratio of the release agent is preferably in the range of 1% by mass or more and 30% by mass or less in the toner, and more preferably in the range of 3% by mass or more and 15% by mass or less.

[0122] <Charge control agent> The toner according to the present invention may further contain a charge control agent. The charge control agent to be used is a substance that can give 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.

[0123] The content ratio of the charge control agent is preferably in the range of 0.01% by mass or more and 30% by mass or less, more preferably in the range of 0.1% by mass or more and 10% by mass or less, in the toner.

[0124] <External additive> In order to improve the fluidity, chargeability, cleaning property, etc. of the toner, external additives such as fluidizing agents and cleaning aids, which are so-called post-treatment agents, may be added to the toner particles to form the toner of the present invention.

[0125] Examples of the external additive include inorganic particles such as 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 can be used alone or in combination of two or more.

[0126] These inorganic particles may be surface-treated with a silane coupling agent, a titanium coupling agent, a higher fatty acid, silicone oil, etc. to improve heat-resistant storage stability and environmental stability.

[0127] The addition amount of these external additives is preferably in the range of 0.05% by mass or more and 5% by mass or less, more preferably in the range of 0.1% by mass or more and 3% by mass or less, in the toner.

[0128] <Average particle size of toner> The average particle size of the toner is preferably in the range of 4 μm or more and 10 μm or less, more preferably in the range of 6 μm or more and 9 μm or less, in terms of the volume-based median diameter (D50). When the volume-based median diameter (D50) is within the above range, the transfer efficiency is increased, the image quality of halftone is improved, and the image quality of fine lines and dots, etc. is improved.

[0129] In the present invention, the volume-based median diameter (D50) of the toner is measured and calculated using a measuring device connected to a computer system (manufactured by Beckman Coulter, Inc.) equipped with "Software V3.51" for data processing on a "Coulter Counter 3" (manufactured by Beckman Coulter, Inc.).

[0130] Specifically, 0.02 g of the measurement sample (toner) 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 times with pure water for the purpose of dispersing toner particles), and after being allowed to mix well, ultrasonic dispersion is performed for 1 minute to prepare a toner dispersion. This toner 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%.

[0131] Here, by setting the concentration range in this way, 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, and the frequency values are calculated by dividing the measurement range of 1 μm or more and 30 μm or less into 256 parts. The particle diameter at which the volume integration fraction is 50% from the larger side is defined as the volume-based median diameter (D50).

[0132] [Method for manufacturing toner] The method for manufacturing the toner of the present invention is not particularly limited. For example, when using only the propenimine compound as the toner, the propenimine compound obtained by the above synthesis method 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 is preferred.

[0133] When manufacturing a toner that contains the propenimine compound and additives such as a colorant and does not contain a binder resin, it is preferable to use a solvent in which both the propenimine compound and the additives such as the colorant are soluble to dissolve the propenimine compound and the additives such as the colorant to form a solution, then remove the solvent, and thereafter, perform pulverization and classification in the same manner as the method described above.

[0134] When manufacturing a toner that contains the propenimine compound, a binder resin, and additives such as a colorant, it is preferably a manufacturing method that utilizes an emulsion aggregation method that allows for easy control of the particle size and shape.

[0135] Such a manufacturing method (1A) Binder resin particle dispersion preparation step of preparing a dispersion of binder resin particles (1B) Colorant particle dispersion preparation step of preparing a dispersion of colorant particles (1C) Propenimine compound particle dispersion preparation step of preparing a dispersion of propenimine compound particles (2) Aggregation step of adding a flocculant to an aqueous medium in which binder resin particles, colorant particles, and propenimine compound particles are present, allowing salting out to proceed, and simultaneously performing aggregation and fusion to form aggregated particles (3) Aging step of forming toner particles by controlling the shape of the aggregated particles (4) Filtration and washing step of filtering out the toner particles from the aqueous medium and removing surfactants, etc. from the toner particles (5) Drying step of drying the washed toner particles (6) External additive addition step of adding an external additive to the dried toner particles preferably includes each of the following steps. Hereinafter, the steps (1A) to (1C) will be described.

[0136] (1A) Binder resin particle dispersion preparation step In this process, resin particles are formed by emulsion polymerization or the like, which is conventionally known, 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 into an aqueous medium and polymerizing these polymerizable monomers with a polymerization initiator.

[0137] In addition, as a method for obtaining a dispersion of binder resin particles, in addition to the method of polymerizing polymerizable monomers with a polymerization initiator in the above aqueous medium, for example, a method of performing a dispersion treatment in an aqueous medium without using a solvent, or a method of dissolving a binder resin (crystalline resin, etc.) 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, and then performing a solvent removal treatment, etc. can be mentioned.

[0138] At this time, if necessary, the binder resin may be preliminarily contained with a release agent (wax). Further, 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, dodecylbenzene sulfonic acid). Further, after mixing the surfactant, in order to impart aggregability, it is also preferable to add a base such as an aqueous sodium hydroxide solution to the mixture in advance and adjust the pH to 9 to 12. In addition, a release agent particle dispersion may be prepared in the same manner as in the coloring agent particle dispersion preparation step separately from the binder resin particle dispersion, and may be present in the aqueous medium in the association step of (2) above. The above surfactant may also be used when preparing a coloring agent particle dispersant or the like.

[0139] The median diameter of the binder resin particles in the dispersion on a volume basis is preferably in the range of 50 nm or more and 300 nm or less. 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.).

[0140] (1B) Coloring Agent Particle Dispersion Preparation Step This step of preparing the coloring agent particle dispersion liquid is a step of dispersing the coloring agent into fine particles in an aqueous medium to prepare a dispersion liquid of the coloring agent particles.

[0141] The dispersion of the coloring agent can be carried out by using mechanical energy. The median diameter of the coloring agent particles in the dispersion liquid is preferably in the range of 10 nm or more and 300 nm or less, and more preferably in the range of 50 nm or more and 200 nm or less, based on the number of particles. The median diameter of the coloring agent particles based on the number of particles can be measured using an electrophoretic light scattering photometer "ELS-800" (manufactured by Otsuka Electronics Co., Ltd.).

[0142] (1C) Step of preparing the propenimine compound particle dispersion liquid This step of preparing the propenimine compound particle dispersion liquid is a step of dispersing the propenimine compound into fine particles in an aqueous medium to prepare a dispersion liquid of the propenimine compound particles. In preparing the propenimine compound particle dispersion liquid, first, an emulsion of the propenimine compound is prepared. Examples of the method for preparing the emulsion of the propenimine compound include, for example, a method in which a propenimine compound solution obtained by dissolving the propenimine compound in an organic solvent is emulsified in an aqueous medium.

[0143] The method of dissolving the propenimine compound in an organic solvent is not particularly limited. For example, there is a method in which the propenimine compound is added to the organic solvent and stirred and mixed so that the propenimine compound is dissolved. The addition ratio of the propenimine compound is preferably in the range of 5 parts by mass or more and 100 parts by mass or less, and more preferably in the range of 10 parts by mass or more and 50 parts by mass or less, based on 100 parts by mass of the organic solvent.

[0144] Next, the propenimine compound solution and the aqueous medium are mixed and stirred using a known disperser such as a homogenizer. As a result, the propenimine compound becomes droplets and is emulsified in the aqueous medium, and an emulsion of the propenimine compound is prepared.

[0145] The addition ratio of the propenimine compound solution is preferably in the range of 10 parts by mass or more and 110 parts by mass or less, more preferably 20 parts by mass or more and 105 parts by mass or less, based on 100 parts by mass of the aqueous medium.

[0146] Also, when mixing the propenimine compound solution and the aqueous medium, the temperatures of the propenimine compound solution and the aqueous medium respectively are in a temperature range below the boiling point of the organic solvent, preferably in the range of 20°C or more and 80°C or less, more preferably 30°C or more and 75°C or less. When mixing the propenimine compound solution and the aqueous medium, the temperature of the propenimine compound solution and the temperature of the aqueous medium may be the same as or different from each other, and preferably they are the same as each other.

[0147] For example, when the volume of the disperser is 1 L or more and 3 L or less, the stirring conditions are preferably such that the rotation speed is in the range of 7000 rpm or more and 20000 rpm or less, and the stirring time is preferably in the range of 10 minutes or more and 30 minutes or less.

[0148] The propenimine compound particle dispersion is prepared by removing the organic solvent from the emulsion of the propenimine compound. Examples of the method for removing the organic solvent from the emulsion of the propenimine compound include known methods such as blowing, heating, reduced pressure, or a combination thereof.

[0149] As an example, the emulsion of the propenimine compound is heated, for example, in an inert gas atmosphere such as nitrogen, preferably in the range of 25°C or more and 90°C or less, more preferably 30°C or more and 80°C or less, until about 80% by mass or more and 95% by mass or less of the initial amount of the organic solvent is removed, whereby the organic solvent is removed. Thereby, the organic solvent is removed from the aqueous medium, and a propenimine compound particle dispersion in which the propenimine compound particles are dispersed in the aqueous medium is prepared.

[0150] The mass average particle diameter of the propenimine compound particles in the propenimine compound particle dispersion is preferably in the range of 90 nm or more and 1200 nm or less. The mass average particle diameter of the propenimine compound particles can be set within the above range by appropriately adjusting the viscosity when the propenimine compound is blended in an organic solvent, the blending ratio of the propenimine compound solution and water, the stirring speed of the disperser when preparing the emulsion of the propenimine compound, and the like. The mass average particle diameter of the propenimine compound particles in the propenimine compound particle dispersion can be measured using an electrophoretic light scattering photometer "ELS-800" (manufactured by Otsuka Electronics Co., Ltd.).

[0151] <organic solvent> The organic solvent used in this step is not particularly limited as long as it can dissolve the propenimine compound of the present invention 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.

[0152] Such organic solvents can be used alone or in combination of two or more. Among these organic solvents, ketones and halogenated hydrocarbons are preferred, and methyl ethyl ketone and dichloromethane are more preferred.

[0153] <aqueous medium> The aqueous medium used in this step includes water, or an aqueous medium containing water as a main component and blended with water-soluble solvents such as alcohols and glycols, and optional components such as surfactants and dispersants. The aqueous medium is preferably a mixture of water and a surfactant.

[0154] 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 lauryl ether, polyoxyethylene sorbitan monooleate ether, monodecanoyl sucrose, etc.

[0155] 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.

[0156] The addition amount of the surfactant is preferably in the range of 0.01 parts by mass or more and 10 parts by mass or less, more preferably 0.04 parts by mass or more and 1 part by mass or less, based on 100 parts by mass of the aqueous medium.

[0157] (2) The steps from the association step to the external additive addition step (6) can be carried out according to various conventionally known methods.

[0158] In addition, the flocculant used in the (2) meeting process 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 metal salts include sodium chloride, potassium chloride, lithium chloride, calcium chloride, magnesium chloride, zinc chloride, copper sulfate, magnesium sulfate, manganese sulfate, etc. Among these, it is particularly preferable to use divalent metal salts because aggregation can proceed with a smaller amount. These can be used alone or in combination of two or more.

[0159] [Developer] For example, when the toner of the present invention contains a magnetic substance and is used as a one-component magnetic toner, when it is mixed with a so-called carrier and used as a two-component developer, when a non-magnetic toner is used alone, etc. can be considered, and all can be preferably used.

[0160] As the above magnetic substance, for example, magnetite, γ - hematite, or various ferrites can be used.

[0161] As the carrier constituting 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.

[0162] As the carrier, it is preferable to use a coated carrier in which the surface of magnetic particles is coated with a coating agent such as resin, or a so-called 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, styrene resin, styrene-acrylic resin, silicone resin, polyester resin, fluororesin, or the like is used. Further, the resin for constituting the resin-dispersed carrier is not particularly limited, and known resins can be used, for example, acrylic resin, styrene-acrylic resin, polyester resin, fluororesin, phenol resin, or the like can be used.

[0163] The median diameter of the carrier based on volume is preferably in the range of 20 μm or more and 100 μm or less, and more preferably in the range of 25 μm or more and 80 μm or less. The median diameter of the carrier based on volume can typically be measured by a laser diffraction particle size distribution measuring device "HELOS" (manufactured by SYMPATEC) equipped with a wet disperser.

[0164] The mixing amount of the toner with respect to the carrier is preferably in the range of 2% by mass or more and 10% by mass or less, with the total mass of the toner and the carrier being 100% by mass.

[0165] [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 a monochrome image forming method or a full-color image forming method. In the full-color image forming method, it can be applied to any image forming method such as a 4-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.

[0166] An image forming method according to an embodiment of the present invention is an image forming method having a step of fixing an image by light irradiation, the method including: a step of forming an image on a recording medium using a toner containing the propenimine compound; a step of irradiating the image formed on the recording medium with light in a wavelength region preferably in the range of 280 nm or more and 420 nm or less, more preferably in the range of 300 nm or more and 400 nm or less, and even more preferably in the range of 330 nm or more and 390 nm or less; and a step of fixing the image. In the step of irradiating the light, using light in the wavelength region of 280 nm or more and 420 nm or less is suitable because it mainly well absorbs light in the ultraviolet region, improves the light fusibility, sufficiently fluidizes the propenimine compound in the toner, and quickly softens the image (toner image) on the recording medium. If the wavelength of the light irradiation becomes shorter than 280 nm, the energy increases and there is a risk that the compound (organic substance) will be broken (decomposed). On the other hand, if the wavelength of the light irradiation is longer than 420 nm, there is a risk that the propenimine compound having no absorption region on the long wavelength side will not be fluidized. From the viewpoint of obtaining better fixing property, the step of fixing the image on the recording medium preferably includes a step of pressing the recording medium on which the image is formed by a pressing member. Further, from the viewpoint of obtaining better fixing property, the temperature of the pressing member is preferably 30°C or more and 100°C or less.

[0167] 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. Although FIG. 1 shows an example of a monochrome image forming apparatus 100, the present invention can also be applied to a color image forming apparatus.

[0168] The image forming apparatus 100 is an apparatus for forming an image on a recording paper S as a recording medium, includes an image reading device 71 and an automatic document feeder 72, and forms an image on the recording paper S conveyed by a paper conveyance system 7 by an image forming unit 10, an irradiation unit 40, and a pressure bonding unit 9.

[0169] In addition, as the recording medium, the image forming apparatus 100 uses the recording paper S, but the medium to be subjected to image formation may be other than paper.

[0170] The 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 the 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.

[0171] 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, and the like. The trays 16 each accommodate recording paper S of a determined size, and operate the paper feeding unit 11 of the determined tray 16 in response to an instruction from the control unit 90 to supply the recording paper S. The conveyance rollers 12 convey the recording paper S sent out from the tray 16 by the paper feeding unit 11 or the recording paper S carried in from the manual paper feeding unit 15 to the image forming unit 10.

[0172] The image forming unit 10 is configured such that a charger 2, an exposure device 3, a developing unit 4, a transfer unit 5, a discharging unit 6, and a cleaning unit 8 are arranged in this order along the rotation direction of the photoreceptor 1 around the photoreceptor 1.

[0173] The photoreceptor 1, which is an image carrier, is an image carrier having 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). A thermometer and hygrometer 17 for detecting the temperature and humidity inside the image forming apparatus 100 is provided near the photoreceptor 1.

[0174] The charger 2 uniformly applies charges to 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 on the photoreceptor 1 according to the image data. The developing unit 4 supplies the toner accommodated therein to the photoreceptor 1 to form a toner image based on the electrostatic latent image on the surface of the photoreceptor 1.

[0175] The transfer unit 5 faces the photoreceptor 1 via the recording paper S and transfers the toner image to the recording paper S. The charge removing unit removes the charge on the photoreceptor 1 after the toner image is transferred. 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.

[0176] The recording paper S on which the toner image is transferred is conveyed by the conveying belt 13, irradiated with light by the irradiation unit 40, and then conveyed to the pressure bonding unit 9. The pressure bonding unit 9 is optionally installed, and performs a fixing process on the recording paper S on 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 discharging unit 14 by the conveying roller and discharged out of the machine from the paper discharging unit 14.

[0177] In addition, 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 to the paper reversing unit 24 in front of the paper discharging unit 14, 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.

[0178] <Irradiation unit> Figure 2 is a schematic configuration diagram of the irradiation unit 40 in the image forming apparatus 100.

[0179] According to an embodiment of the present invention, an image forming apparatus 100 includes an irradiation unit 40 capable of irradiating a toner image on a recording paper S conveyed by a conveyance belt 13 with light under appropriate irradiation conditions above the conveyance belt 13 between the transfer unit 5 and the pressure bonding unit 9. Examples of devices constituting the irradiation unit 40 include a light emitting diode (LED), a laser light source, and the like. As the irradiation unit 40, for example, a scanning type irradiation unit 40 capable of performing scanning exposure (light irradiation) on the toner image on the recording paper at a (super) high speed to irradiate the entire toner image in a short time may be used. Alternatively, a fixed type irradiation unit 40 in which a large number of light sources are arranged without gaps in a horizontal row (a direction perpendicular to the conveyance direction) or vertically and horizontally so as to be able to irradiate the entire toner image on the recording paper at once may be used. There is no particular limitation, and conventionally known light irradiation techniques can be applied.

[0180] The irradiation unit 40 melts and fluidizes a compound (the propenimine compound of the present invention) that undergoes a phase transition by light absorption contained in the toner in the toner image (image) by light irradiation. The wavelength of the light irradiated by the irradiation unit 40 only needs to be such that it can be sufficiently fluidized, preferably in the range of 280 nm or more and 420 nm or less, more preferably in the range of 300 nm or more and 400 nm or less, and even more preferably in the range of 330 nm or more and 390 nm or less. It is ultraviolet light having a wavelength within this range. When the wavelength of the light irradiated by the irradiation unit 40 is within the above range, by well absorbing the light in the ultraviolet region, the light fusibility is improved, and the fixing property is improved when applied to the toner. Further, by irradiating the irradiation light having the above wavelength, it can be fluidized without applying heat or pressure. Therefore, by introducing the above propenimine compound into the toner, fixing at the above wavelength becomes possible, and a toner with high color reproducibility can be obtained. The light irradiation amount in the irradiation unit 40 only needs to be such that the propenimine compound of the present invention that undergoes a phase transition by light absorption contained in the toner of the developer can be sufficiently melted and fluidized, preferably 0.1 J / cm 2 or more and 200 J / cm 2 or less, more preferably 0.5 J / cm 2 or more and 100 J / cm 2 or less, and even more preferably 1.0 J / cm 2 or more and 50 J / cm2 Within the following range. When the light irradiation amount is 0.1 J / cm 2 or more energy, the reaction of E→Z (fluidization) occurs over the energy barrier, the photo-melting property improves, and the propenimine compound can be fluidized. On the other hand, when the light irradiation amount is 200 J / cm 2 or less, the energy is not too large, and the propenimine compound can be fluidized well without being broken.

[0181] When non-fluidizing the propenimine compound of the present invention that undergoes a phase transition by light absorption contained in the toner in the image, it may be left at room temperature (non-heated; in the range of 25 ± 15 °C) without applying external energy or external force such as light irradiation, heating, and pressurization. Specifically, after passing through the fixing unit 9 as necessary, it may be discharged by conveyance as it is and left at room temperature.

[0182] Note that even when non-fluidization is performed, the light irradiation shown below may be carried out. The irradiation part (not shown) during non-fluidization may be provided on the upstream side of the irradiation part 40. When the fixing part 9 is provided as necessary, an irradiation part capable of irradiating light on the toner image on the recording paper S conveyed by the conveyance belt above the conveyance belt on the downstream side of the fixing part 9 under appropriate irradiation conditions may be provided. The wavelength of the light irradiated by the irradiation part during non-fluidization only needs to be sufficient for non-fluidization and solidification, and is preferably longer than the irradiation light during fluidization. For example, it is in the range of 400 nm or more and 800 nm or less, preferably in the range of 420 nm or more and 800 nm or less, more preferably in the range of 430 nm or more and 730 nm or less. At wavelengths of 800 nm or less, since it does not enter the infrared region, heat generation does not occur, heat loss due to photothermal conversion can be prevented, and the irradiation energy can be efficiently used for the photoisomerization reaction. At wavelengths of 400 nm or more, since it does not enter the ultraviolet region, it can be appropriately non-fluidized without being fluidized. From these facts, the best region is in the range of 450 nm or more and 650 nm or less. In this range, by well absorbing light in the visible light region, the photocurability is improved, and the fixing property is improved when applied to the toner. Also, by irradiating the irradiation light of the above wavelength, non-fluidization can be achieved without applying heat or pressure. Therefore, by introducing the propenimine compound into the toner, the toner image on the recording paper can be more reliably solidified, the fixing property of the toner image to the recording paper can be further improved, and a toner with high color reproducibility can be obtained. The light irradiation amount in the irradiation part only needs to be sufficient for non-fluidizing and solidifying the propenimine compound of the present invention that undergoes phase transition due to light absorption contained in the toner of the developer, and is preferably 0.1 J / cm 2 or more and 200 J / cm 2 or less, more preferably 0.5 J / cm 2 or more and 100 J / cm 2 or less, and even more preferably 1.0 J / cm 2 or more and 50 J / cm 2 or less. When the light irradiation amount is 0.1 J / cm 2With the above energy, the reaction of Z→E (non-fluidization) occurs over the energy barrier, and the propenimine compound can be non-fluidized. On the other hand, if the light irradiation amount is 2 200 J / cm or less, the energy is not too large, and the propenimine compound can be satisfactorily non-fluidized and solidified (fixed, adhered, etc.) without being broken.

[0183] That is, the image forming method according to an embodiment of the present invention is an image forming method having a step of fixing an image by light irradiation, including a step of forming an image on a recording medium using a toner containing the propenimine compound, a step of irradiating light in a wavelength region of 280 nm or more and 420 nm or less to the image formed on the recording medium, and a step of fixing the image to the recording medium. If necessary, the step of fixing the image to the recording medium includes a step of irradiating light in a wavelength region of 400 nm or more and 800 nm or less to the softened image to solidify the image. In addition, in the fixing step, it is preferable to further include a step of pressing the softened image. In the pressing step, it is preferable to further heat the softened image at 30°C or more and 100°C or less. This is because heating can further soften the image.

[0184] The irradiation unit 40 and an optional irradiation unit (for non-fluidization; not shown) irradiate light toward the first surface on the photoreceptor side of the recording paper S that holds the image (toner image), and are arranged on the photoreceptor side with respect to the surface of the recording paper S nipped between the photoreceptor 1 and the transfer roller 50. Further, they are arranged in the order of the irradiation unit 40 and the optional irradiation unit along the conveyance direction (paper conveyance direction) of the recording paper S.

[0185] The irradiation unit 40 is arranged on the downstream side in the paper conveyance direction with respect to the nip position between the photoreceptor 1 and the transfer roller 40, and on the upstream side in the paper conveyance direction with respect to the pressure bonding unit 9.

[0186] Any irradiation unit is installed downstream of the irradiation unit 40 in the paper conveyance direction and upstream of the paper discharge unit 14 in the paper conveyance direction. The arbitrary irradiation unit can be installed between the crimping unit 9 and the paper discharge unit 14 in the paper conveyance direction.

[0187] According to the image forming method according to an embodiment of the present invention, after uniformly charging the photosensitive member 1 by the charger 2, the photosensitive member 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 a compound that undergoes a phase transition by light absorption (the propenimine compound of the present invention) is supplied onto the photosensitive member 1 by the developing unit 4.

[0188] When the toner image carried on the surface of the photosensitive member 1 transfers the recording paper S from the tray 16 to the image forming unit 10 in accordance with the position timing of the transfer member 50 by the rotation of the photosensitive member 1, the toner image on the photosensitive member 1 is transferred onto the recording paper S nipped between the transfer member 50 and the photosensitive member 1 by the transfer bias applied to the transfer member 50.

[0189] Further, the transfer member 50 also serves as a pressure member, and while the toner image can be transferred from the photosensitive member 1 to the recording paper S, the propenimine compound contained in the toner image can be surely adhered to the recording paper S.

[0190] 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 photosensitive member 1.

[0191] In the process in which the recording paper S onto which the toner image has been transferred is conveyed to the crimping unit 9 by the conveyance belt 13, the irradiation unit 40 irradiates the image formed by the toner image transferred onto the recording paper S with light in the wavelength range of 280 nm or more and 420 nm or less. By irradiating the image on the first surface of the recording paper S with the light in the above wavelength range by the irradiation unit 40, the image can be more surely melted, and the fixing property of the image to the recording paper S can be improved.

[0192] When the recording paper S holding the image reaches the pressure bonding part 9 by the conveyance belt 13, the pressure members 91 and 92 bond the image to the first surface of the recording paper S. Before the fixing process is performed by the pressure bonding part 9, since the image is softened by the light irradiation in the above wavelength region by the irradiation part 40, energy saving of the image pressure bonding to the recording paper S can be achieved. That is, the image forming method of the present invention preferably further includes a step of pressing the softened image by a pressure member before solidifying the image and fixing it to the recording medium as a step of solidifying the image and fixing it to the recording medium. By applying pressure by the pressure members 91 and 92, the fixability of the image to the recording paper S is further improved. The pressure members 91 and 92 preferably have a roller shape.

[0193] The pressure when pressing the image on the recording medium is not particularly limited, but is preferably 0.01 MPa or more and 5.0 MPa or less, and more preferably 0.05 MPa or more and 1.0 MPa or less. By setting the pressure to 0.01 MPa or more, the amount of deformation of the image can be increased, so the contact area between the 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 pressurization can be suppressed.

[0194] In addition, the pressure member 91 can heat the toner image (image) on the recording paper S when the recording paper S passes between the pressure members 91 and 92. The toner image (image) softened by light irradiation is further softened by this heating and then pressed, so that the fixability of the toner image (image) to the recording paper S is further improved. The temperature of the pressure member 91 when heating is preferably 30°C or more and 100°C or less, and preferably 40°C or more and 100°C or less. The pressure member 91 used as the heating member may be a contact type or a non-contact type as long as it can heat the toner, but a non-contact type heating member is preferred because it does not heat the toner until it is softened.

[0195] It is preferable that the recording paper S that has passed between the pressing members 91 and 92 is left at room temperature without providing means for non-fluidization until it reaches the paper discharge unit 14. By leaving it at room temperature without providing means for non-fluidization until it reaches the paper discharge unit 14, the image on the recording paper S can be surely solidified, and the fixing property of the toner image to the recording paper S can be improved. However, if necessary, an arbitrary irradiation unit may be provided to irradiate the image on the recording paper S with visible light in the wavelength range of 400 nm or more and 800 nm or less. By irradiating the visible light in the above wavelength range from this arbitrary irradiation unit, the image on the recording paper S can be surely solidified, and the fixing property of the toner image to the recording paper S can be improved.

[0196] In the image forming method of the present invention, the pressure bonding portion 9 in FIG. 2 may not be provided. That is, with respect to the image formed on the recording medium, after irradiating the image with light in the above wavelength range from the irradiation unit 40 to soften the image, without performing pressure bonding or heating, the recording paper S is left at room temperature without providing means for non-fluidization until it reaches the paper discharge unit 14, and it is preferable to solidify the image and fix (adhere) it to the recording medium. However, without performing pressure bonding or heating, the softened image may be irradiated with visible light in the above wavelength range from an arbitrary irradiation unit to solidify the image and fix (adhere) it to the recording medium.

[0197] When forming images on both sides of the recording paper S, the recording paper S subjected to the pressure bonding process is conveyed to the paper inversion unit 24 in front of the paper discharge unit 14, the front and back are inverted and discharged, or the recording paper S with the front and back inverted is conveyed to the image forming unit 10 again.

[0198] (Photoresponsive adhesive) Since the propenimine compound of the present invention is fluidized by light irradiation and reversibly immobilized, a photo-responsive adhesive that can be repeatedly used can be produced using the propenimine compound of the present invention. For example, corresponding to the change in viscosity (friction coefficient), it can be applied to various adhesion technologies as an adhesive that can be repeatedly detached by desorption (fluidization) by light irradiation and adhesion (immobilization) in a natural environment (left at room temperature).

[0199] The photo-responsive 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 at all.

[0200] (Photo-switching material) Since the propenimine compound (photo-responsive compound) of the present invention is fluidized by light irradiation and reversibly immobilized, a photo-switching material can be produced using the propenimine compound of the present invention. For example, a photo-switching material can be produced by utilizing changes in color, polarity, mass transfer, orientation, viscosity, and surface tension accompanying photo-isomerization. For example, in a liquid crystal material or the like, corresponding to the change in the orientation of molecules accompanying photo-isomerization, it can be applied to pattern drawing that can be repeatedly rewritten. Also, for example, microfabrication of the surface of a polymer film can be performed by utilizing the change in surface tension accompanying light irradiation and the resulting mass transfer. That is, one embodiment of the present invention is a photo-switching material containing the propenimine compound of the present invention. For example, the propenimine compound of this embodiment can be used as it is or with an appropriate amount of any known additive added as a photo-switching material.

[0201] The photo-switching material of the present invention can be used for liquid crystal display materials and surface processing of polymer films, but is not limited thereto at all.

Examples

[0202] The effects of the present invention will be described using the following examples and comparative examples. However, the technical scope of the present invention is not limited only to the following examples.

[0203] [Synthesis of Propeneimine Compound] (Synthesis of Compound No. 5)

[0204] [Chemical Formula]

[0205] To a 50 ml four-necked flask equipped with a condenser and a thermometer, 3-(4-(hexyloxy)phenyl)acetylaldehyde (5.00 g, 21.5 mmol) (Raw material 1), 4-hexyloxyaniline (4.16 g, 21.5 mmol) (Raw material 2), and 20 ml of ethanol were added and stirred. This was refluxed for 5 hours in the range of an internal temperature of 77 °C or higher and 78 °C or lower.

[0206] After confirming by thin-layer chromatography (TLC) that 4-hexyloxyaniline had disappeared and the internal temperature had dropped to room temperature, the reaction solution was added to 200 ml of water to stop the reaction. The target product was extracted with ethyl acetate and washed with water. After drying the ethyl acetate solution, it was concentrated to obtain crude crystals of Compound No. 5. This was recrystallized from ethanol to obtain 8.07 g (yield: 92%) of the target product, Compound No. 5.

[0207] 1 H-NMR (CDCl3, 400 MHz) δ (ppm); 8.70 (S, 1H), 7.22 (D, 1H), 6.85 (D, 1H), 6.96 (D, 2H), 7.68 (D, 2H), 7.39 (D, 2H), 7.01 (D, 2H), 6.96 (D, 2H), 4.11 (T, 4H), 1.80 (M, 4H), 1.47~1.37 (M, 12H), 0.89 (T, 6H).

[0208] (Synthesis of Compounds No. 1 to 4, 6 to 57) 3-(4-(hexyloxy)phenyl)acetylaldehyde (Raw material 1) and 4-hexylaniline (Raw material 2) were synthesized in the same manner as the synthesis of Compound No. 5, except that acetylaldehyde (Raw material 1) and aniline (Raw material 2) shown in Table 2-1, Table 2-2 and Table 2-3 below were used respectively, and the target compounds 1-4, 6-57 were synthesized.

[0209] Similar to Compound No. 5, 1 The formation of the compounds was confirmed by 1H NMR, and it was found that the target compounds 1-4, 6-57 were obtained. Among these, the 1H NMR of several compounds is shown below. 1 1H NMR of some compounds is shown below.

[0210] ·Compound No. 3 1 1H-NMR (CDCl3, 400 MHz) δ (ppm); 7.68 (M, 2H), 7.64 (S, 1H), 7.26 (D, 2H), 7.22 (D, 2H), 7.01 (M, 2H), 4.11 (M, 2H), 2.65 (M, 2H), 2.07 (S, 3H), 1.26 - 1.47 (M, 6H), 1.33 - 1.74 (M, 20H), 0.89 (T, 6H).

[0211] ·Compound No. 7 1 1H-NMR (CDCl3, 400 MHz) δ (ppm); 8.70 (S, 1H), 7.59 (D, 2H), 7.26 (D, 2H), 6.22 (D, 2H), 7.01 (D, 2H), 6.34 (S, 1H), 4.11 (T, 2H), 2.64 (T, 2H), 2.44 (M, 2H), 1.74 (M, 2H), 1.63 (M, 2H), 1.43 (M, 2H), 1.26 - 1.29 (M, 30H), 1.07 (T, 3H), 0.89 (T, 6H).

[0212] ·Compound No. 10 1H-NMR (CDCl3, 400 MHz) δ (ppm); 8.7 (S, 1H), 7.39 (D, 2H), 7.10 (S, 2H), 6.96 (D, 2H), 6.78 (S, 1H), 5.36 (S, 1H), 4.11 (T, 2H), 2.64 (T, 4H), 2.12 (S, 3H), 1.77 (M, 2H), 1.39 (M, 4H), 1.26 - 1.29 (M, 10H), 0.89 - 0.90 (M, 9H).

[0213] · Compound No. 14 1 H-NMR (CDCl3, 400 MHz) δ (ppm); 8.7 (S, 1H), 8.19 (S, 1H), 7.64 (D, 2H), 7.29 (D, 1H), 7.22 (D, 1H), 7.05 (D, 1H), 6.85 (D, 1H), 6.77 (D, 2H), 4.11 (T, 2H), 1.80 (M, 2H), 1.58 (M, 2H), 1.47 (M, 2H), 1.29 - 1.37 (M, 12H), 0.89 (T, 6H).

[0214] · Compound No. 22 1 H-NMR (CDCl3, 400 MHz) δ (ppm); 8.70 (S, 1H), 7.93 (S, 1H), 7.52 (D, 1H), 7.19 - 7.20 (M, 2H), 7.09 (T, 1H), 6.73 - 6.75 (M, 2H), 5.36 (S, 1H), 4.11 (T, 2H), 2.64 (T, 2H), 2.12 (S, 3H), 1.80 (M, 2H), 1.56 (M, 2H), 1.42 (M, 2H), 1.26 - 1.33 (M, 16H), 0.89 (T, 6H).

[0215] · Compound No. 23 1 H-NMR (CDCl3, 400 MHz) δ (ppm); 8.7 (S, 1H), 7.68 (D, 2H), 7.22 (D, 2H), 7.01 (D, 2H), 6.85 (D, 1H), 6.26 (S, 2H), 4.11 (T, 6H), 1.74 (M, 6H), 1.43 - 1.47 (M, 6H), 1.26 - 1.29 (M, 10H), 0.96 (T, 6H), 0.89 (T, 3H).

[0216] · Compound No. 27 1 H-NMR(CDCl3, 400 MHz) δ(ppm); 8.70 (S, 1H), 7.39 (D, 2H), 7.08 (D, 1H), 6.96 (D, 2H), 6.85 (D, 1H), 6.67 (D, 1H), 6.65 (M, 1H), 4.11 (T, 2H), 2.44 (S, 3H), 1.88 (M, 2H), 1.47 (M, 2H), 1.37 (M, 4H), 0.89 (T, 3H).

[0217] · Compound No. 29 1 H-NMR(CDCl3, 400 MHz) δ(ppm); 7.66 (S, 1H), 7.39 (D, 2H), 6.90 - 6.96 (M, 4H), 4.11 (T, 2H), 2.76 (M, 2H), 2.07 (S, 3H), 1.80 (M, 2H), 1.37 - 1.47 (M, 6H), 1.18 (T, 3H), 0.89 (T, 3H).

[0218] · Compound No. 31 1 H-NMR(CDCl3, 400 MHz) δ(ppm); 8.70 (S, 1H), 7.74 (D, 1H), 7.39 (D, 2H), 6.95 - 6.96 (T, 3H), 6.85 (D, 1H), 6.72 (D, 1H), 6.50 (T, 1H), 4.11 (T, 2H), 1.80 (M, 2H), 1.47 (M, 2H), 1.37 (M, 4H), 0.89 (T, 3H).

[0219] · Compound No. 34 1 H-NMR(CDCl3, 400 MHz) δ(ppm); 8.15 (S, 1H), 7.25 (D, 1H), 6.95 (D, 1H), 6.75 - 6.8 (M, 4H), 4.11 (T, 2H), 2.34 (S, 6H), 2.07)S, 3H), 1.77 (M, 2H), 1.39 (M, 4H), 0.90 (T, 3H).

[0220] · Compound No. 35 1H-NMR (CDCl3, 400 MHz) δ (ppm); 9.40 (S, 1H), 8.7 (S, 1H), 7.39 (D, 2H), 6.96 (D, 2H), 6.85 (D, 1H), 6.72 (D, 1H), 6.37 (D, 1H), 5.73 (D, 1H), 4.11 (T, 2H), 2.29 (S, 3H), 1.74 (M, 2H), 1.43 (M, 2H), 1.26 - 1.29 (M, 5H), 0.89 (T, 3H).

[0221] · Compound No. 37 1 H-NMR (CDCl3, 400 MHz) δ (ppm); 8.7 (S, 1H), 7.39 (D, 2H), 7.15 (D, 1H), 6.96 (D, 2H), 6.85 (D, 1H), 6.72 (D, 1H), 6.64 (D, 1H), 6.07 (T, 1H), 4.11 (T, 2H), 3.91 (S, 3H), 1,80 (M, 2H), 1.47 (T, 2H), 1.37 (M, 4H), 0.89 (T, 3H).

[0222] · Compound No. 39 1 H-NMR (CDCl3, 400 MHz) δ (ppm); 8.7 (S, 1H), 7.22 - 7.26 (M, 4H), 6.85 (D, 1H), 6.79 (D, 1H), 6.41 (S, 1H), 5.85 (S, 1H), 3.60 (S, 3H), 2.64 (T, 2H), 2.19 (S, 3H), 1.63 (T, 2H), 1.26 (M, 16H), 0.89 (T, 3H).

[0223] · Compound No. 41 1 H-NMR (CDCl3, 400 MHz) δ (ppm); 8.7 (S, 1H), 7.59 (D, 2H), 7.35 (D, 1H), 7.01 (D, 2H), 6.64 - 6.67 (M, 2H), 4.11 (T, 2H), 2.44 (S, 3H), 2.14 (S, 3H), 1.74 (M, 2H), 1.43 (M, 2H), 1.26 - 1.30 (M, 8H), 0.89 (T, 3H).

[0224] · Compound No. 44 1H-NMR (CDCl3, 400 MHz) δ (ppm); 8.7 (S, 1H), 7.68 (D, 2H), 7.44 (D, 1H), 7.22 (D, 1H), 7.01 (D, 2H), 6.85 (D, 1H), 6.35 - 6.38 (M, 2H), 4.11 (T, 2H), 1.80 (M, 2H), 1.47 (M, 2H), 1.37 (M, 4H), 0.89 (T, 3H).

[0225] · Compound No. 46 1 H-NMR (CDCl3, 400 MHz) δ (ppm); 8.7 (S, 1H), 7.29 (D, 1H), 7.16 (D, 1H), 6.92 (D, 2H), 6.77 (D, 2H), 5.36 (S, 1H), 2.71 (M, 2H), 2.64 (M, 2H), 2.12 (S, 3H), 1.63 (T, 2H), 1.26 (M, 12H), 1.18 (M, 3H), 0.89 (T, 3H).

[0226] · Compound No. 49 1 H-NMR (CDCl3, 400 MHz) δ (ppm); 8.7 (S, 1H), 7.59 - 7.60 (D, 3H), 7.01 (D, 2H), 6.34 (S, 1H), 6.06 (D, 1H), 5.88 (D, 1H), 4.11 (T, 2H), 2.44 (M, 2H), 2.29 (S, 3H), 1.77 (M, 2H), 1.39 (M, 4H), 1.07 (M, 3H), 0.90 (T, 3H).

[0227] · Compound No. 51 1 H-NMR (CDCl3, 400 MHz) δ (ppm); 8.7 (S, 1H), 7.68 (D, 2H), 7.22 (D, 2H), 7.01 (D, 2H), 6.85 (D, 2H), 6.05 (D, 1H), 5.94 (D, 1H), 4.24 (M, 2H), 4.11 (T, 2H), 2.19 (S, 3H), 1.80 (M, 2H), 1.47 (M, 2H), 1.33 (M, 4H), 1.06 (M, 3H), 0.89 (T, 3H).

[0228] · Compound No. 53 1H-NMR (CDCl3, 400 MHz) δ (ppm); 8.7 (S, 1H), 7.59 (D, 2H), 7.01 (D, 2H), 6.34 (D, 2H), 5.98 (D, 1H), 4.11 (T, 2H), 3.60 (S, 3H), 2.44 (M, 2H), 2.09 (S, 3H), 1.74 (M, 2H), 1.43 (M, 2H), 1.26 (M, 26H), 1.07 (T, 3H), 0.89 (T, 3H).

[0229] · Compound No. 54 1 H-NMR (CDCl3, 400 MHz) δ (ppm); 8.7 (S, 1H), 7.62 (M, 1H), 7.39 (D, 2H), 7.09 - 7.29 (M, 3H), 6.96 (D, 2H), 6.85 (D, 1H), 6.72 (D, 1H), 6.5 (S, 1H), 4.11 (T, 2H), 3.99 (S, 3H), 1.80 (M, 2H), 1.4 (M, 6H), 0.9 (T, 3H).

[0230] · Compound No. 56 1 H-NMR (CDCl3, 400 MHz) δ (ppm); 8.7 (S, 1H), 7.39 (D, 2H), 7.0 (M, 3H), 6.85 (D, 1H), 6.72 (D, 1H), 4.1 (T, 2H), 2.6 (M, 2H), 1.8 (M, 2H), 1.3 - 1.5 (M, 9H), 0.9 (T, 3H).

[0231]

Table 2-1

[0232]

Table 2-2

[0233]

Table 2-3

[0234] (Synthesis of Comparative Compound (Azobenzene Compound) 1) In the same manner as “Synthesis of (1-2-1) UV softening material B” described in paragraphs “0227” to “0237” of JP-A-2014-191078, comparative compound 1 (an azobenzene compound) represented by the following chemical formula (2) was obtained. Similar to Compound No. 5, 1 The formation of the comparative compound was confirmed by 1H NMR, and it was found that the target comparative compound 1 was obtained.

[0235]

Chemical formula

[0236] (Synthesis of comparative compound (stilbene compound) 2)

[0237]

Chemical formula

[0238] To a 50 ml four-necked flask equipped with a condenser and a thermometer, 4-(hexyloxy)benzaldehyde (3.00 g, 14.5 mmol) (raw material 1), diethyl (4-(hexyloxy)benzyl)phosphonate (5.25 g, 16.0 mmol) (raw material 2), potassium t-butoxide (2.12 g, 18.9 mmol) and 25 ml of dimethylformamide (DMF) were added and stirred. This was heated and reacted at an internal temperature in the range of 60 °C or higher and 75 °C or lower for 3 hours.

[0239] It was confirmed by thin layer chromatography (TLC) that 4-(hexyloxy)benzaldehyde had disappeared. After the internal temperature had dropped to room temperature, the reaction solution was added to 250 ml of water to stop the reaction. The target product was extracted with ethyl acetate and washed with water. After drying the ethyl acetate solution, it was concentrated to obtain crude crystals of comparative compound 2. This was purified by silica gel column chromatography, and the concentrated crystals were recrystallized from ethanol to obtain 4.86 g (yield: 88%) of the target comparative compound 2. Similar to Compound No. 5, 1 The formation of the comparative compound was confirmed by 1H NMR, and it was found that the target comparative compound 2 was obtained.

[0240]

Chem.

[0241] For each substituent of Compounds 1 to 57 (the aromatic rings A (aromatic hydrocarbon group or aromatic heterocyclic group) of Ar1 and Ar2 in General Formula (1), the substituents (a) and (b) of each aromatic ring, R1 to R 10 , X (hetero group), Y, Z1, Z2), the constitution is as shown in Tables 1-1 to 1-5 above. Also, the structures of Comparative Compound (azobenzene compound) 1 and Comparative Compound (stilbene compound) 2 are as shown in Chemical Formulas (2) and (3) above.

[0242] <Evaluation Method> [Photoresponse Adhesion Test] For Compounds of Examples 1 to 20 and Comparative Examples 1 and 2 (Compound Nos. 2, 7, 10, 14, 18, 22, 25, 27, 29, 31, 34, 35, 39, 41, 46, 49, 51, 53, 54, 57 and Comparative Compounds 1 and 2), the change in adhesiveness accompanying light irradiation was evaluated by the following photoresponse adhesion test using the apparatus shown in Figure 3.

[0243] As shown in Figure 3, 2 mg of the compound was placed on a 18 mm square cover glass 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 compound at a position shifted by about 4 mm in a parallel direction with respect to cover glass 1. This was heated to melt the sample (compound), and cover glass 1 and cover glass 2 were adhered. Each obtained sample was subjected to the following non-fluid → fluid test, and then to the following fluid → non-fluid test.

[0244] <Non-fluid → Fluid Test (Fluidization Test)> The portion (A) shown in Figure 3 was fixed to the stage with cellophane tape, and a 30 cm long vinyl string with a 100 g weight attached was fixed to the portion (C) with cellophane tape. The portion (B) was irradiated with light having a wavelength of 365 nm at an irradiation amount of 30 J / cm 2Irradiate it and check whether the cover glass 2 peels off from the cover glass 1, and make a determination according to the following evaluation criteria. The obtained results are shown in Tables 2-1 to 2-5 below.

[0245] -Evaluation criteria for the test of non-fluidity → fluidity (fluidization test)- 〇: The cover glass 2 has completely peeled off from the cover glass 1 △: The cover glass 2 has shifted ×: The cover glass 2 did not move.

[0246] <Test of fluidity → non-fluidity (non-fluidization test)> Five minutes after the end of the light irradiation in the non-fluidity → fluidity test (the five minutes were left in the natural environment, that is, at room temperature), place a cover glass 3 (the same size as the cover glasses 1 and 2) so as to cover the sample part ((B) part) of the cover glass 1 used in the above test, and check whether the cover glass 1 and the cover glass 3 adhere, and make a determination according to the following evaluation criteria. The obtained results are shown in Tables 2-1 to 2-5.

[0247] -Evaluation criteria for the test of fluidity → non-fluidity (non-fluidization test)- 〇: Did not adhere (was non-fluidized) △: Partially adhered (partially maintained the fluidized state) ×: Adhered (maintained the fluidized state).

[0248]

Table 2-1

[0249]

Table 2-2

[0250]

Table 2-3

[0251]

Table 2-4

[0252]

Table 2-5

[0253] In Table 2-5, for Comparative Compound 2 of Comparative Example 2, in the non-fluidity → fluidity test (fluidization test), cover glass 2 did not move. Therefore, in the subsequent fluidity → non-fluidity test (non-fluidization test), cover glass 3 could not be placed to cover the sample portion ((B) portion) of cover glass 1. Thus, for Comparative Compound 2 of Comparative Example 2, the fluidity → non-fluidity test (non-fluidization test) could not be conducted and evaluated, so the evaluation column for the "non-fluidization test" was marked as "-".

[0254] [Preparation of Binder Resin] (Preparation of Styrene-Acrylic Resin Particle Dispersion Liquid 1 Containing Styrene-Acrylic Resin 1) (First Stage Polymerization) A solution prepared by dissolving 8 parts by mass of sodium dodecyl sulfate in 3000 parts by mass of ion-exchanged water was charged into a reaction vessel equipped with a stirring device, a temperature sensor, a cooling pipe, 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. After the temperature rise, a solution prepared by dissolving 10 parts by mass of potassium persulfate in 200 parts by mass of ion-exchanged water was added, and the solution temperature was set to 80°C again. A polymerizable monomer solution composed of 480 parts by mass of styrene, 250 parts by mass of n-butyl acrylate, 68.0 parts by mass of methacrylic acid, and 16.0 parts by mass of n-octyl-3-mercaptopropionate was added dropwise over 1 hour, and then polymerization was carried out by heating and stirring at 80°C for 2 hours to prepare a styrene-acrylic resin particle dispersion liquid (1A) containing styrene-acrylic resin particles (1a).

[0255] (Second Stage Polymerization) A solution prepared by dissolving 7 parts by mass of sodium polyoxyethylene-2-dodecyl ether sulfate in 800 parts by mass of ion-exchanged water was charged into a reaction vessel equipped with a stirring device, a temperature sensor, a cooling pipe, and a nitrogen introduction device. After heating to 98 °C, 260 parts by mass of the above styrene acrylic resin particle dispersion (1A), 245 parts by mass of styrene, 120 parts by mass of n-butyl acrylate, 1.5 parts by mass of n-octyl-3-mercaptopropionate, and 67 parts by mass of paraffin wax "HNP-11" (manufactured by Nippon Seiro Co., Ltd.) as a release agent, which was dissolved at 90 °C, were added as a polymerizable monomer solution. The mixture was mixed and dispersed for 1 hour by a mechanical disperser "CREARMIX" (manufactured by M Technique Co., Ltd.) having a circulation path to prepare a dispersion containing emulsified particles (oil droplets).

[0256] Next, an initiator solution prepared by dissolving 6 parts by mass of potassium persulfate in 200 parts by mass of ion-exchanged water was added to this dispersion, and the system was heated and stirred at 82 °C for 1 hour to perform polymerization, thereby preparing a styrene acrylic resin particle dispersion (1B) containing styrene acrylic resin particles (1b).

[0257] (Third-stage polymerization) A solution prepared by dissolving 11 parts by mass of potassium persulfate in 400 parts by mass of ion-exchanged water was added to the above styrene acrylic resin particle dispersion (1B). Under a temperature condition of 82 °C, a polymerizable monomer solution composed of 435 parts by mass of styrene, 130 parts by mass of n-butyl acrylate, 33 parts by mass of methacrylic acid, and 8 parts by mass of n-octyl-3-mercaptopropionate was added dropwise over 1 hour. After completion of the dropwise addition, polymerization was carried out by heating and stirring for 2 hours, and then cooled to 28 °C to obtain a styrene acrylic resin particle dispersion 1 containing styrene acrylic resin 1.

[0258] When the particle size of the styrene acrylic resin particles in the above styrene acrylic resin particle dispersion 1 was measured by the dynamic light scattering method using "Microtrac UPA-150" (manufactured by Nikkiso Co., Ltd.), the median diameter based on volume was 140 nm. Also, when the glass transition temperature Tg of this styrene acrylic resin 1 was measured, it was 45 °C.

[0259] (Preparation of Polyester Resin Particle Dispersion Liquid 1 Containing Polyester Resin 1) Into a 10-liter four-necked flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple, 524 parts by mass of a bisphenol A propylene oxide 2-mol adduct, 105 parts by mass of terephthalic acid, 69 parts by mass of fumaric acid, and 2 parts by mass of tin octylate (esterification catalyst) were charged, and a polycondensation reaction was carried out at a temperature of 230 °C for 8 hours. Further, after continuing the polycondensation reaction at 8 kPa for 1 hour, it was cooled to 160 °C to obtain Polyester Resin 1.

[0260] 100 parts by mass of the obtained Polyester Resin 1 was pulverized with a "Randmill Model: RM" (manufactured by Tokuju Kogyosho Co., Ltd.), mixed with 638 parts by mass of a 0.26 mass% aqueous sodium lauryl sulfate solution prepared in advance, and ultrasonic-dispersed at V-LEVEL and 300 μA for 30 minutes using an ultrasonic homogenizer "US-150T" (manufactured by Nippon Seiki Co., Ltd.) while stirring to obtain Polyester Resin Particle Dispersion Liquid 1.

[0261] When the particle diameter of the polyester resin particles in the above Polyester Resin Particle Dispersion Liquid 1 was measured by the dynamic light scattering method using a "Microtrac UPA-150" (manufactured by Nikkiso Co., Ltd.), the median diameter based on volume was 135 nm. Also, when the glass transition temperature Tg of this Polyester Resin 1 was measured, it was 42 °C.

[0262] [Example 25: Preparation of Toner 25] (Preparation of Cyan Colorant Particle Dispersion Liquid) 11.5 parts by mass of sodium n-dodecyl sulfate was dissolved in 1600 parts by mass of pure water, 25 parts by mass of copper phthalocyanine (C.I. Pigment Blue 15:3) was gradually added, and then a cyan colorant particle dispersion liquid was prepared using "Clear Mix (registered trademark) W Motion CLM-0.8" (manufactured by M-Technique Co., Ltd.).

[0263] The median diameter based on volume of the colorant particles in the cyan colorant particle dispersion liquid was 110 nm.

[0264] (Preparation of Propeneimine Compound Particle Dispersion 5) 80 parts by mass of dichloromethane and 20 parts by mass of the propeneimine compound 5 were mixed and stirred while heating at 50 °C to obtain a solution containing the propeneimine compound 5. To 100 parts by mass of this solution, a mixture of 99.5 parts by mass of distilled water warmed to 50 °C and 0.5 parts by mass of a 20 mass% aqueous sodium dodecylbenzenesulfonate solution 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 a propeneimine compound emulsion 5.

[0265] The obtained propeneimine compound emulsion 5 was put into a separable flask, and while introducing nitrogen into the gas phase, it was heated and stirred at 40 °C for 90 minutes to remove the organic solvent, thereby obtaining a propeneimine compound particle dispersion 5. The mass average particle diameter of the propeneimine compound particles in the obtained propeneimine compound particle dispersion 5 was 120 nm. The mass average particle diameter of the propeneimine compound particles in the propeneimine compound particle dispersion was measured using an electrophoretic light scattering photometer "ELS-800" (manufactured by Otsuka Electronics Co., Ltd.).

[0266] (Aggregation, Fusion) 504 parts by mass of the styrene-acrylic resin particle dispersion 1 prepared above in terms of solid content, 216 parts by mass of the propeneimine compound particle dispersion 5 in terms of solid content, 900 parts by mass of ion-exchanged water, and 70 parts by mass of the cyan coloring agent particle dispersion in terms of solid content were put into a reaction apparatus equipped with a stirrer, a temperature sensor, and a cooling pipe. The temperature inside the container was maintained at 30 °C, and a 5 mol / l aqueous sodium hydroxide solution was added to adjust the pH to 10.

[0267] Next, an aqueous solution prepared by dissolving 2 parts by mass of magnesium chloride hexahydrate in 1000 parts by mass of ion-exchanged water was added dropwise over 10 minutes with stirring, and then the temperature was raised. The system was heated to 70°C over 60 minutes and the particle growth reaction was continued while maintaining 70°C. In this state, the particle size of the aggregated particles was measured using a "Multisizer 3" (manufactured by Beckman Coulter, Inc.). When the median diameter (D50) on a volume basis reached 6.5 μm, an aqueous solution prepared by dissolving 190 parts by mass of sodium chloride in 760 parts by mass of ion-exchanged water was added to stop the particle growth. After stirring at 70°C for 1 hour, the temperature was further raised, and the particles were fused by heating and stirring at 75°C. Thereafter, the mixture was cooled to 30°C to obtain a dispersion of toner particles.

[0268] The dispersion of toner particles obtained above was separated into solid and liquid by a centrifuge to form a wet cake of toner particles. The wet cake was washed with ion-exchanged water at 35°C using the centrifuge until the electrical conductivity of the filtrate reached 5 μS / cm, and then transferred to a "Flash Jet Dryer" (manufactured by Seishin Enterprise Co., Ltd.) and dried until the moisture content reached 0.5% by mass to produce Toner 25.

[0269] [Examples 21 to 24 and 26 to 77; Preparation of Toners 21 to 24 and 26 to 77] Toners 21 to 24 and Toners 26 to 77 were prepared in the same manner as the preparation of Toner 25, except that the type of the propenimine compound was changed as described in Table 3.

[0270] [Examples 78 to 83; Preparation of Toners 78 to 83] Toners 78 to 83 were prepared in the same manner as the preparation of Toner 25, except that the addition amount (ratio) of the propenimine compound was changed as described in Table 3.

[0271] [Examples 84 to 86; Preparation of Toners 84 to 86] Styrene-acrylic resin particle dispersion 1 was changed to polyester resin particle dispersion 1 (the binder resin was changed from styrene-acrylic resin to polyester resin as described in Table 3), and toners 84 to 86 were prepared in the same manner as for toner 25, except that the addition amount (ratio) of the propenimine compound was changed as described in Table 3.

[0272] Also, for Examples 87 and 88, toner 25 was used.

[0273] [Comparative Examples 3 - 4; Preparation of Toners 87 - 88] Toners 87 and 88 were prepared in the same manner as for toner 25, except that the propenimine compound was changed to Comparative Compound (azobenzene compound) 1 and Comparative Compound (stilbene compound) 2 described in Table 3.

[0274] [Preparation of Developers 21 - 88] 9.5 g of iron powder with a volume-based median diameter of 70 μm and 0.5 g of toner were placed in a 20 ml glass container and shaken at 200 times per minute, with a shaking angle of 45 degrees and an arm length of 50 cm for 20 minutes to prepare Developers 21 - 88.

[0275] [Image Formation and Its Evaluation Method] [Image Formation Method] Using each of the obtained developers, a toner image was formed on plain paper as a recording medium to obtain a printed matter. Specifically, on one side, the developer was placed, and on the other side, gloss-coated paper (basis weight: 128 g / m 2 ) was placed between a pair of parallel flat plate (aluminum) electrodes. The developer was arranged while being slid by magnetic force, and the toner was developed under the conditions that the electrode gap was 0.5 mm, and the DC bias and AC bias were such that the toner adhesion amount was 4 g / m 2 . A toner layer was formed on the surface of the plain paper and fixed by a fixing device to obtain a printed matter.

[0276] [Evaluation: Fixing Property Test] The 1-cm square image of this printed matter was rubbed 10 times with a pressure of 50 kPa using a "JK Wiper (registered trademark)" (manufactured by Nippon Paper Crecia Co., Ltd.) and evaluated based on the image fixing rate. A fixing rate of 50% or more was considered a pass. The evaluation results (fixing rate) of the obtained fixing property test are shown in Tables 3-1 and 3-2 below. The image fixing rate is a numerical value expressed as a percentage, which is obtained by measuring the density of the image after printing and the image after rubbing with a reflection densitometer "RD-918" (manufactured by Sakata Inx Engineering Co., Ltd.) and dividing the reflection density of the solid image after rubbing by the reflection density of the solid image after printing.

[0277] As the fixing device, the following three types of devices, which were configured by appropriately modifying the device shown in Fig. 2, were used.

[0278] Fixing device No. 1: There is no crimping part 9 in Fig. 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 10 J / cm 2 is.; Fixing device No. 2: There is a crimping part 9 in Fig. 2. The temperature of the pressing member 91 is 20 °C (non-heated), 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 the fixing device No. 1; Fixing device No. 3: There is a crimping part 9 in Fig. 2. The temperature of the pressing member 91 is 80 °C (heated), 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 the fixing device No. 1.

[0279] [Color reproducibility evaluation] The color reproducibility of the example images obtained above was evaluated according to the following evaluation criteria by visual evaluation by 10 monitors. Specifically, as evaluation comparison samples, for each toner described in each example, a toner excluding only the propenimine compound was prepared, and for the toners 91 and 92 described in Comparative Examples 3 and 4, a toner excluding only Comparative Compound (azobenzene compound) 1 and Comparative Compound (stilbene compound) 2 was prepared. They were developed in the same manner as the [image forming method] above and fixed using the following Fixing Device No. 4, which was configured by appropriately modifying the device shown in Fig. 2.

[0280] Fixing device No. 4: It has the crimping part 9 in Fig. 2. The temperature of the pressing member 91 is 150 °C (heating), and the pressure during pressing is 0.2 MPa. On the other hand, there is no irradiation part 40 in Fig. 2, and the device configuration is such that light irradiation is not carried out.

[0281] For 10 monitors, the evaluation comparison sample and the sample of the example were shown in order, and they were asked whether the colors of the two images were clearly different. The determination results according to the following color reproducibility evaluation criteria are shown in Table 3-1 and Table 3-2 below.

[0282] - Evaluation criteria for color reproducibility - ◎: Two or fewer people answered that they were clearly different. ○: Three to four people answered that they were clearly different. △: Five to seven people answered that they were clearly different. ×: Eight or more people answered that they were clearly different.

[0283] The composition of each compound, toner (developer), the type of fixing device, and the evaluation results (fixing rate (%), color reproducibility) are shown in Table 3-1 and Table 3-2 below.

[0284]

Table 3-1

[0285]

Table 3-2

[0286] "Compound No." in Table 3-1 and Table 3-2 refers to "Compound No." of the propenimine compound having each substituent of the general formula (1) shown in Tables 1-1 to 1-5. Comparative Compounds 1 and 2 in Table 3-2 refer to Comparative Compound 1 (azobenzene compound) and Comparative Compound 2 (stilbene compound) represented by the above chemical formulas (2) and (3). "Ratio" in Table 3-1 and Table 3-2 indicates the ratio (mass%) of the propenimine compound to the total amount of the propenimine compound and the binder resin in the toner. "Ratio" in Comparative Examples 3 and 4 of Table 3-2 indicates the ratio (mass%) of the azobenzene compound to the total amount of the azobenzene compound and the binder resin in the toner.

[0287] As is clear from Table 3-1 and Table 3-2 above, the toners of Examples 21 to 88 exhibited high fixing rates and excellent color reproducibility.

[0288] This is because the azobenzene compound and the stilbene compound contained in the toners of Comparative Examples 3 and 4 have a strong absorption due to the n-π * transition in the long wavelength region because the conjugation is extended by the introduction of the benzene ring. Therefore, even when mixed with a colorant, the azobenzene compound and the stilbene compound have a color, and the desired color reproduction could not be achieved. On the other hand, in the toner of this Example, by containing a propenimine compound represented by the general formula (1) having a -C=C-C=N- structure, the strong absorption due to the n-π * transition in the long wavelength region can be weakened, and the strong yellow color development disappears. Therefore, it was confirmed that the desired color reproduction can be realized even when mixed with a colorant.

[0289] Also, in the toner of this example, the aromatic ring of the above propenimine compound is substituted with an alkyl group or an alkoxy group (see Table 1). Since these alkyl groups and alkoxy groups have thermal motility, the propenimine compound contained in the toner of this example forms a specific crystal structure in which a structure isotropically disturbed by the thermal motility of the alkyl group or alkoxy group coexists in a periodic structure dominated by π-π interaction. Therefore, when the cis-trans isomerization reaction proceeds locally and the π-π interaction of the propenimine part is reduced, isotropic melting occurs chainwise throughout the system. Thus, it is considered that trans-cis isomerization becomes more likely to proceed, and fluidization of the toner due to light irradiation is likely to occur.

[0290] Furthermore, it is considered that the toner of this example was able to control the Z→E reaction rate by including a propenimine compound in which a vinylene group with a high energy barrier and a slow Z→E reaction rate was connected to an azomethine group with a low energy barrier. That is, even when the propenimine compound is irradiated with light and changes (fluidizes) from the trans form (E) to the cis form (Z), it was possible to control the Z→E reaction (non-fluidization) rate of the reverse reaction so that it was not too fast, and it is considered that the softened state necessary for fixing could be maintained.

[0291] From these facts, it is considered that by introducing a propenimine compound that is colorless but induces a reversible fluidization / non-fluidization phenomenon with isomerization into the toner, a high fixing rate and excellent color reproducibility due to light irradiation were ultimately achieved.

[0292] On the other hand, it was found that the toner of Comparative Example 3 had a fixing rate lower than 50% and poor color reproducibility. It was also found that the toner of Comparative Example 4 had a fixing rate significantly lower than 50%. Since the light irradiation conditions (ultraviolet light source and irradiation amount) by the irradiation unit 40 used in the fixing property test were constant throughout Examples 21 to 8 and Comparative Examples 1 and 2, it can be said that the toner of the examples was reversibly fluidized and non-fluidized by light irradiation and the effect of the propenimine compound without significant coloring was sufficiently exhibited compared to the toner of the comparative examples. That is, the toner of the examples was found to have good fixing properties with significantly improved softening rates (both the fluidization rate (E→Z reaction rate) and the reverse non-fluidization rate (Z→E reaction rate)) without affecting the desired color reproduction even when a colorant was added, as compared to the toner of the comparative examples. It was also found that an image forming method excellent in color reproducibility and fixing property of an image using the above toner could be provided.

[0293] When comparing fixing devices, it was found that sufficient fixing property was achieved even with only light irradiation by the No. 1 fixing device without using a pressure member and with light irradiation by the light irradiation device 40 under the same conditions. Also, it was found that the fixing property was improved by applying pressure by using the No. 2 fixing device with pressure applied by a pressure member, and further the No. 3 fixing device with pressure applied while heating with a pressure member (comparison of Examples 25, 87, and 88). Furthermore, it was impossible to fix with only pressure using a conventional toner, and the photo-melting toner of the present invention had better fixing property and required less light irradiation energy applied during fixing than the conventional fixing energy (heating + pressure energy) when heating and pressurizing a conventional toner. From this, it can be seen that the No. 1 fixing device that does not apply pressure or heat is most preferable from the viewpoints of simplification and miniaturization of the configuration, energy saving, and prevention of global warming (CO2 reduction).

[0294] In Examples, regarding the relationship between the type of binder resin in the toner and the "ratio" of the propenimine compound, in the case of polyester resin, the "ratio" of the propenimine compound is preferably in the range of 10% by mass or more and less than 70% by mass, more preferably in the range of 20% by mass or more and 60% by mass or less, and even more preferably in the range of 30% by mass or more and 50% by mass or less. In the case of styrene-acrylic resin, the "ratio" of the propenimine compound is preferably in the range of 10% by mass or more and 70% by mass or less, more preferably in the range of 20% by mass or more and 60% by mass or less, and even more preferably in the range of 20% by mass or more and 50% by mass or less. That is, when the ratio of the propenimine compound in the toner is within the above range, the ratio of the binder resin becomes sufficiently high, and high fixability can be obtained. From the above range of the "ratio", it can be said that either styrene-acrylic resin or polyester resin is good as the binder resin.

[0295] In Examples 25 to 77 where the propenimine compound in the toner was changed, from a wide range of viewpoints such as ease of production, manufacturing cost, yield, storage stability, ease of handling, durability, and further the influence on toner performance other than fixability and color reproducibility, in addition to the above fixability and color reproducibility, suitable compounds are Compound No. 2, 3, 5, and 10. Also, from the viewpoint of compatibility, suitable examples are Examples 22, 25, 35, and 57. Note that when considering only the fixability of the toner, Compound No. 2, 5, 6, 15, 31, 37, 44 (Examples 22, 25, 26, 35, 51, 57, 64) are preferable.

Explanation of Signs

[0296] 1 Photoconductor, 2 Charger, 3 Exposure device, 4 Developing unit, 5 Transfer unit, 6 Static eliminator, 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 discharge unit, 15 manual paper feed unit, 16 tray, 17 thermometer, 20 image processing unit, 24 paper inversion unit, 40 irradiation unit, 50 transfer roller, 71 image reading device, 72 automatic document feeder, 85 blade, 90 control unit, 91, 92 pressure members, 100 image forming apparatus, d document, S recording paper.

Claims

1. A compound represented by the following general formula (1): 【Chemical 1】 In the general formula (1), Ar １ and Ar ２ One of them is a phenyl group having a substituent (a), and the other is an aromatic heterocyclic group which may have a substituent (b). The aromatic heterocyclic group is selected from the group consisting of a pyridine ring group, a furan ring group, a thiophene ring group, a pyrrole ring group, an indole ring group, an imidazole ring group, and a thiazole ring group. the substituent (a) is at least an alkyl group having 4 to 18 carbon atoms or an alkoxy group having 4 to 18 carbon atoms, and the phenyl group having the substituent (a) may further have a substituent selected from the group consisting of an alkyl group having 1 to 3 carbon atoms and an alkoxy group having 1 to 3 carbon atoms; the substituent (b) is an alkyl group having 1 to 18 carbon atoms, an alkoxy group having 1 to 18 carbon atoms, or an aromatic hydrocarbon group which may have a substituent (c), and the substituent (c) is, independently of each other, an alkyl group having 1 to 8 carbon atoms or an alkoxy group having 1 to 8 carbon atoms; Y, Z １ and Z ２ each independently represents a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms.

2. The compound according to claim 1, wherein the linear or branched alkyl group having 1 to 6 carbon atoms is an alkyl group having 1 to 2 carbon atoms.

3. A toner containing the compound according to claim 1 or 2.

4. The toner according to claim 3, further containing a binder resin.

5. The toner according to claim 4, wherein the binder resin contains at least one selected from the group consisting of a styrene-acrylic resin and a polyester resin.

6. The toner according to any one of claims 3 to 5, further containing a colorant.

7. A step of forming an image on a recording medium using a toner containing the compound according to claim 1 or 2; A step of irradiating light in a wavelength region of 280 to 420 nm to the image formed on the recording medium; A step of fixing the image to the recording medium; An image forming method characterized by including the above steps.

8. The image forming method according to claim 7, wherein the step of fixing the image to the recording medium includes a step of pressing the recording medium on which the image is formed by a pressing member.

9. The image forming method according to claim 8, wherein the temperature of the pressing member is 30°C or higher and 100°C or lower.

10. A photo-responsive adhesive using the compound according to claim 1 or 2.

11. A photo-switching material using the compound according to claim 1 or 2.

Images