JP5895801B2 - Electrostatic image developing toner, electrostatic image developer, toner cartridge, process cartridge, image forming apparatus, image forming method, and croconium compound - Google Patents

Description

  The present invention relates to an electrostatic charge image developing toner, an electrostatic charge image developer, a toner cartridge, a process cartridge, an image forming apparatus, an image forming method, and a croconium compound.

Patent Document 1 discloses a method for producing squalium and croconium dyes containing a hetero 6-membered ring.
Patent Document 2 contains an infrared absorbing material having a spectral absorption maximum wavelength of 750 nm to 1100 nm and an absorbance at 650 nm of 5% or less of the absorbance at the spectral absorption maximum wavelength. A forming electrophotographic toner is disclosed.

Japanese Patent Laid-Open No. 2001-11070 JP 2002-146254

  SUMMARY OF THE INVENTION An object of the present invention is to provide a toner for developing an electrostatic charge image that suppresses color fog.

The above problem is solved by the following means. That is,
The invention according to claim 1
An electrostatic charge image developing toner comprising a binder resin and an infrared absorber represented by the following general formula (I).

In general formula (I), R ¹¹ , R ¹² , R ²¹ and R ²² each independently represent a halogen group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted alkoxy group. R ³¹ and R ³² each independently represent a hydrogen atom or an aliphatic group. n11 and n12 each independently represent an integer of 0 or more and 4 or less, and n21 and n22 each independently represent an integer of 0 or more and 5 or less. X represents an oxygen atom or a sulfur atom. When n11 represents an integer of 2 or more and 4 or less, the plurality of R ¹¹ may be independently the same or different and may be bonded to each other to form a ring. When n12 represents an integer of 2 or more and 4 or less, the plurality of R ¹² may be independently the same or different and may be bonded to each other to form a ring. When n21 represents an integer of 2 or more and 5 or less, the plurality of R ²¹ may be independently the same or different and may be bonded to each other to form a ring. When n22 represents an integer of 2 or more and 5 or less, the plurality of R ²² may be independently the same or different and may be bonded to each other to form a ring. However, R ¹¹ and R ²¹ , R ¹¹ and R ²² , R ¹² and R ²¹ , and R ¹² and R ²² are not bonded to each other to form a ring.

The invention according to claim 2
The electrostatic image developing toner according to claim 1, comprising a colorant.

The invention according to claim 3
3. The electrostatic charge image developing toner according to claim 1, wherein a maximum absorption wavelength of the infrared absorber is in a range of 860 nm to 1200 nm.

The invention according to claim 4
An electrostatic charge image developer comprising the electrostatic charge image developing toner according to claim 1.

The invention according to claim 5
A toner cartridge that accommodates the electrostatic image developing toner according to claim 1 and is detachable from an image forming apparatus.

The invention according to claim 6
5. A developing unit that stores the electrostatic image developer according to claim 4 and that develops the electrostatic latent image formed on the surface of the electrostatic latent image holding member with the electrostatic image developer to form a toner image. And a process cartridge that is detachable from the image forming apparatus.

The invention according to claim 7 provides:
An electrostatic latent image carrier;
Charging means for charging the surface of the electrostatic latent image holding member;
Electrostatic latent image forming means for forming an electrostatic latent image on the surface of the charged electrostatic latent image holding member;
5. A development for containing the electrostatic charge image developer according to claim 4 and developing a toner image by developing the electrostatic latent image formed on the surface of the electrostatic latent image holding member with the electrostatic charge image developer. Means,
Transfer means for transferring the toner image to a recording medium;
Fixing means for fixing the toner image transferred to the recording medium;
An image forming apparatus.

The invention according to claim 8 provides:
The image forming apparatus according to claim 7, wherein the fixing unit is a unit that fixes the toner image transferred to the recording medium with a laser beam.

The invention according to claim 9 is:
A charging step for charging the electrostatic latent image holding member;
An electrostatic latent image forming step of forming an electrostatic latent image on the surface of the charged electrostatic latent image holding member;
5. A development for containing the electrostatic charge image developer according to claim 4 and developing a toner image by developing the electrostatic latent image formed on the surface of the electrostatic latent image holding member with the electrostatic charge image developer. Process,
A transfer step of transferring the toner image to a recording medium;
A fixing step of fixing the toner image transferred to the recording medium;
Is an image forming method.

The invention according to claim 10 is:
The image forming method according to claim 9, wherein the fixing step is a step of fixing the toner image transferred to the recording medium with a laser beam.

The invention according to claim 11 is:
It is a croconium compound represented by the following general formula (II) or general formula (III).

In the general formula (II), R ¹¹¹ , R ¹¹² , R ²¹¹ , and R ²¹² each independently represent a halogen group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkoxy group, and R ³¹¹ and R ³¹² each independently represents a hydrogen atom or an aliphatic group. n111 and n112 each independently represent an integer of 0 or more and 4 or less, and n211 and n212 each independently represent an integer of 0 or more and 5 or less. X represents an oxygen atom or a sulfur atom. When n111 represents an integer of 2 or more and 4 or less, the plurality of R ¹¹¹ may be independently the same or different and are not bonded to each other to form a ring. If n112 is an integer of 2 to 4, a plurality of R ¹¹² are each independently may be the same or different, do not form a ring bonded to each other. If n211 represents an integer of 2 to 5, a plurality of R ²¹¹ are each independently may be the same or different, do not form a ring bonded to each other. When n212 represents an integer of 2 or more and 5 or less, the plurality of R ²¹² may be independently the same or different and are not bonded to each other to form a ring.

In general formula (III), R ²²¹ and R ²²² each independently represent a halogen group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkoxy group, and R ³²¹ and R ³²² are each independently Represents a hydrogen atom or an aliphatic group. n221 and n222 each independently represent an integer of 0 or more and 5 or less. X represents an oxygen atom or a sulfur atom. When n221 represents an integer of 2 or more and 5 or less, the plurality of R ²²¹ may be independently the same or different. When n222 represents an integer of 2 or more and 5 or less, the plurality of R ²²² may be independently the same or different and do not bond to each other to form a ring.

According to the first aspect of the invention, it is possible to provide a toner for developing an electrostatic charge image in which the occurrence of color fog is suppressed as compared with the case where the toner does not contain the infrared absorbent represented by the general formula (I).
According to the second aspect of the present invention, there is provided an electrostatic charge image developing toner containing a colorant that suppresses the occurrence of color fog as compared with a case where the toner does not contain an infrared absorber represented by the general formula (I). it can.
According to the invention of claim 3, the electrostatic charge image development in which the occurrence of color fog is suppressed as compared with the case where the maximum absorption wavelength of the infrared absorber represented by the general formula (I) contained in the toner is outside the above range. Toner can be provided.

According to the inventions according to claims 4 to 7, the electrostatic charge image developer that suppresses the occurrence of color fog as compared with the case where the toner containing the infrared absorber represented by the general formula (I) is not applied, A toner cartridge, an image forming apparatus, and an image forming method can be provided.
According to the eighth and tenth aspects, the image forming apparatus and the image forming which are superior in the fixability of the toner image by the laser beam compared to the case where the toner containing the infrared absorbent represented by the general formula (I) is not applied. Can provide a method.

  According to the eleventh aspect, it is possible to provide a novel croconium compound useful as an infrared absorber with less visible light absorption compared to the infrared absorbers represented by the comparative compounds H-01 and H-02.

1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an exemplary embodiment. It is a schematic block diagram which shows an example of the process cartridge which concerns on this embodiment.

  Embodiments that are examples of the present invention will be described below.

<Toner for electrostatic image development>
The electrostatic image developing toner according to the present embodiment (hereinafter referred to as “toner”) includes a binder resin and an infrared absorber represented by the general formula (I).

The toner according to the present exemplary embodiment suppresses the occurrence of color fog due to the above configuration.
The reason for this is not clear, but is thought to be due to the following reasons.

The infrared absorber represented by the general formula (I) has a spectral maximum absorption wavelength on the long wavelength side as compared with conventional infrared absorbers such as cyanine, aminium, phthalocyanine, and naphthalocyanine.
Here, since the infrared absorber represented by the general formula (I) has a spectral maximum absorption wavelength on the long wavelength side as described above, the absorption region on the short wavelength side from the spectral maximum wavelength region of the infrared absorber. However, even if it is not included or included in the range of the visible region, it is considered that there is no influence on the appearance of the toner image fixed on the recording medium using the toner according to the present embodiment.
As described above, the infrared absorbing agent efficiently absorbs light in the infrared region because the infrared absorbing agent has a resonance structure and the spatial spread of the π-conjugated system is relatively large. This is considered to contribute to the stabilization of the energy of the agent.
Since the infrared absorber represented by the general formula (I) has a larger number of benzene rings than a known croconium compound shown in a comparative example described later, the spatial spread of the π-conjugated system of the croconium compound is large. Conceivable. For this reason, the infrared absorber represented by the general formula (I) has a maximum absorption wavelength on the longer wavelength side as compared with the croconium compound shown in the comparative example, so that it is considered that absorption of light in the visible region hardly occurs. .
From the above, it is considered that the toner according to the present embodiment suppresses the occurrence of color fog.

When generation of color turbulence is suppressed, when the colorant is not contained in the toner, it is difficult to become opaque even if absorption in the visible region of the infrared absorber is not added or added. When the colorant is included in the toner, for example, when the color toner is used, the target color is easily reproduced even if the visible region of the infrared absorbent is not added or added.
Therefore, the toner image fixed on the recording medium obtained with the toner according to the present embodiment is reduced in color change and easily reproduces the target color.

In the case of a photo-fixing toner, the infrared absorber represented by the general formula (I) does not absorb or slightly absorbs light in the visible region. Therefore, the infrared absorber is mainly not visible light. The energy captured by absorbing infrared light is released as heat, and the binder resin is melted to fix the toner image on the recording medium.
Therefore, since visible light does not contribute to fixing of the toner image, even when a black toner and a colored toner having different visible light absorption amounts are used in combination, there is little difference in energy obtained from the irradiation light by the infrared absorber, It is considered that a difference in fixability hardly occurs depending on the type of toner. For the same reason, it is considered that when colored toner is used, a difference in fixability hardly occurs depending on the type of toner.

Moreover, since the infrared absorption agent represented by the general formula (I) has a spectral maximum wavelength on the longer wavelength side as described above, fixing light that emits a wavelength corresponding to the spectral maximum wavelength is used. In particular, it becomes easy to use a laser having a wavelength of 860 nm or more that is excellent in energy conversion efficiency, that is, luminous efficiency. And it becomes easy to reduce the addition amount of the said infrared absorption wavelength by matching the spectral maximum absorption wavelength of an infrared absorber with the wavelength of a laser beam.
As described above, the spatial spread of the π-conjugated system of the infrared absorber represented by the general formula (I) is considered to contribute to the absorption in the infrared region. By controlling the size of the spatial structure of the resonance structure and π-conjugated system by introducing substituents into the infrared absorber and the bonding position of the introduced substituents, the desired maximum is within the infrared region. It will be easier to design for the absorption wavelength.

  Hereinafter, details of the toner according to the exemplary embodiment will be described.

The toner according to the exemplary embodiment includes, for example, toner particles and, if necessary, an external additive.
The toner particles include, for example, an infrared absorbent, a binder resin, and, if necessary, a colorant and other additives.

Hereinafter, an embodiment in which the infrared absorber is internally added to the toner particles will be described. However, the infrared absorber may be externally added to the toner particles.
However, it is better that the infrared absorber is internally added to the toner particles. This is because it is considered that heat is easily transferred to the entire binder resin of the toner particles without unevenness and the toner fixing property is improved as compared with the toner externally added with the infrared absorber.

[Infrared absorber]
An infrared absorber is an infrared absorber represented by the following general formula (I).

In general formula (I), R ¹¹ , R ¹² , R ²¹ and R ²² each independently represent a halogen group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted alkoxy group. R ³¹ and R ³² each independently represent a hydrogen atom or an aliphatic group.
n11 and n12 each independently represent an integer of 0 or more and 4 or less, and n21 and n22 each independently represent an integer of 0 or more and 5 or less.
X represents an oxygen atom or a sulfur atom.
When n11 represents an integer of 2 or more and 4 or less, the plurality of R ¹¹ may be independently the same or different and are bonded to each other to form a ring (eg, cyclic alkyl, cyclic alkenyl, aromatic ring (eg, benzene). Ring))) may be formed.
When n12 represents an integer of 2 or more and 4 or less, the plurality of R ¹² may be independently the same or different and are bonded to each other to form a ring (eg, cyclic alkyl, cyclic alkenyl, aromatic ring (eg, benzene). Ring))) may be formed.
When n21 represents an integer of 2 or more and 5 or less, the plurality of R ²¹ may be independently the same or different and are bonded to each other to form a ring (eg, cyclic alkyl, cyclic alkenyl, aromatic ring (eg, benzene). Ring))) may be formed.
When n22 represents an integer of 2 or more and 5 or less, the plurality of R ²² may be independently the same or different and are bonded to each other to form a ring (eg, cyclic alkyl, cyclic alkenyl, aromatic ring (eg, benzene). Ring))) may be formed.
However, R ¹¹ and R ²¹ , R ¹¹ and R ²² , R ¹² and R ²¹ , and R ¹² and R ²² are not bonded to each other to form a ring.

Examples of the halogen group represented by R ¹¹ , R ¹² , R ²¹ and R ²² in the general formula (I) include F, Cl, Br, I and the like. Of these, F and Cl are preferable.

The unsubstituted alkyl group represented by R ¹¹ , R ¹² , R ²¹ and R ²² in the general formula (I) has, for example, 1 to 18 carbon atoms, preferably 1 to 12 carbon atoms, and more Preferably 1 or more and 8 or less are more desirable, for example, linear, branched, cyclic, or a combination of two or more selected from these may be used. Specific examples of the unsubstituted alkyl group include linear groups such as a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-octyl group, and a butane-1,4-diyl group. An unsubstituted alkyl group; a branched unsubstituted alkyl group such as an iso-propyl group, a tert-butyl group, a 2-ethyl-hexyl group, a tert-octyl group; a cyclohexyl group, a 4-methylcyclohexyl group, a 4- Examples thereof include cyclic unsubstituted alkyl groups such as t-butylcyclohexyl group.

The unsubstituted alkenyl group represented by R ¹¹ , R ¹² , R ²¹ and R ²² in the general formula (I) has, for example, 2 to 18 carbon atoms, preferably 2 to 12 carbon atoms, and more The number is preferably 2 or more and 8 or less, and may be, for example, linear, branched, cyclic, or a combination of two or more selected from these. Specific examples of the unsubstituted alkenyl group include a linear unsubstituted alkenyl group such as an n-propenyl group, an n-butenyl group, a group; an isopropenyl group, and 2-methyl-1-propenyl. A branched unsubstituted alkenyl group such as a group; a cyclic unsubstituted alkenyl group such as a benzene ring and a cyclohexenyl group; and the like.

The unsubstituted alkoxy group represented as R ¹¹ , R ¹² , R ²¹ and R ²² in the general formula (I) has, for example, 1 to 18 carbon atoms, preferably 1 to 12 carbon atoms, and more Preferably they are 1 or more and 8 or less, for example, linear, branched, cyclic, or 2 or more types of combinations selected among these may be sufficient. Specific examples of the unsubstituted alkoxy group include linear chains such as a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group, an n-hexyloxy group, and an ethyl-1,2-dioxy group. -Like unsubstituted alkoxy group; branched unsubstituted alkoxy group such as iso-propoxy group, 2-methylpropyloxy group, tert-octyloxy group; cyclohexyloxy group, 4-t-butylcyclohexyloxy group, etc. Examples thereof include a cyclic unsubstituted alkoxy group.
Here, examples of the substituent that can substitute the alkyl group, the alkenyl group, and the alkoxy group include a halogen group, an alkoxy group, an aryloxy group, an amino group, a cyano group, a hydroxy group, and an alkoxycarbonyl group.

As the bonding position of R ¹¹ and R ¹² in the general formula (I), when n ¹¹ and n ¹² each independently represent 1, for example, 3-, 5-, 6-, 7-, 8- are mentioned. Of these, 7- and 8- are preferable.
When n11 and n12 each independently represent 2, for example, 7,8-, 6,7-, 5,6-6,8-, 5,7- can be mentioned. Of these, 7,8-, 6,7- are preferred.
When n11 and n12 each independently represent 3, for example, 5,6,7-, 3,5,7-, 5,7,8-, 5,6,8- can be mentioned. Of these, 5, 6, 7- is preferable.

As the bonding position of R ²¹ and R ²² in the general formula (I), when n ²¹ and n ²² each independently represent 1, for example, an ortho position, a meta position, and a para position may be mentioned. Of these, the para position is good.
When n21 and n22 each independently represent 2, for example, 2,3-, 2,4-, 2,5-, 2,6-, 3,4-, 3,5- can be mentioned. Of these, 2,4- and 3,5- are preferred.
When n21 and n22 each independently represents 3, for example, 2,3,4-, 2,3,5-, 2,3,6-, 2,4,6-, 3,4,5- Can be mentioned. Of these, 2, 4, 6 is preferable.
When n21 and n22 each independently represents 4, for example, 2,3,4,5-, 2,3,4,6-, 2,3,5,6- can be mentioned. Of these, 2,3,4,5- are preferable.

N11 and n12 in the general formula (I) each independently represents an integer of 0 or more and 4 or less, preferably an integer of 0 or more and 3 or less, and preferably an integer of 0 or more and 2 or less.
N21 and n22 in the general formula (I) each independently represents an integer of 0 or more and 5 or less, preferably an integer of 0 or more and 3 or less, and preferably an integer of 0 or more and 2 or less.

The hydrogen atom or aliphatic group represented by R ³¹ and R ³² in the general formula (I) is preferably a hydrogen atom or an aliphatic group having 1 to 3 carbon atoms, more preferably a hydrogen atom, Or it is a methyl group.

  X in the general formula (I) is represented by an oxygen atom or a sulfur atom, preferably an oxygen atom.

Examples of the compound suitable for the infrared absorber represented by the general formula (I) include croconium compounds represented by the following general formula (II) and general formula (III).

In the general formula (II), R ¹¹¹ , R ¹¹² , R ²¹¹ , and R ²¹² each independently represent a halogen group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkoxy group, and R ³¹¹ and R ³¹² each independently represents a hydrogen atom or an aliphatic group.
n111 and n112 each independently represent an integer of 0 or more and 4 or less, and n211 and n212 each independently represent an integer of 0 or more and 5 or less.
X represents an oxygen atom or a sulfur atom.
When n111 represents an integer of 2 or more and 4 or less, the plurality of R ¹¹¹ may be independently the same or different and are not bonded to each other to form a ring.
If n112 represents an integer of 2 to 4, a plurality of R ¹¹² are each independently may be the same or different, do not form a ring bonded to each other.
If n211 represents an integer of 2 to 5, a plurality of R ²¹¹ are each independently may be the same or different, do not form a ring bonded to each other.
When n212 represents an integer of 2 or more and 5 or less, the plurality of R ²¹² may be independently the same or different and are not bonded to each other to form a ring.

Here, R ¹¹¹ , R ¹¹² , R ²¹¹ , R ²¹² , R ³¹¹ , R ³¹² , n ¹¹¹ , n ¹¹² , n ²¹¹ , n ²¹² , and X in the general formula (II) are each described in the general formula (I). ^{R 11, R 12, R 21} , R 22, R 31, R 32, n11, n12, n21, n22, and is synonymous with X. However, the alkenyl group is excluded from the groups represented by R ¹¹¹ , R ¹¹² , R ²¹¹ , and R ²¹² .

In general formula (III), R ²²¹ and R ²²² each independently represent a halogen group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkoxy group, and R ³²¹ and R ³²² are each independently Represents a hydrogen atom or an aliphatic group.
n221 and n222 each independently represent an integer of 0 or more and 5 or less.
X represents an oxygen atom or a sulfur atom.
When n221 represents an integer of 2 or more and 5 or less, the plurality of R ²²¹ may be independently the same or different.
When n222 represents an integer of 2 or more and 5 or less, the plurality of R ²²² may be independently the same or different and do not bond to each other to form a ring.

Here, R ²²¹ , R ²²² , R ³²¹ , R ³²² , n221, n222, and X in the general formula (III) are R ²¹ , R ²² , R ³¹ , and R described in the general formula (I), respectively. Synonymous with R ³² , n21, n22, and X. However, the alkenyl group is excluded from the groups represented by R ²²¹ and R ²²² .

  Below, the specific example (exemplary compound) of the infrared absorber represented by general formula (I) is shown. In addition, the compound shown by general formula (I) is not limited at all by these.

A method for synthesizing the infrared absorbent represented by the general formula (I) will be described.
First, the infrared absorber represented by the general formula (I) is synthesized according to the following scheme 1, for example. However, in Scheme 1, in general formula (I), X = oxygen atom, R ¹¹ = R ¹² (denoted as R ¹ ), R ²¹ = R ²² (denoted as R ² ), n11 = n12 (denoted as n 1) , N21 = n22 (denoted as n2), R ³¹ = R ³² = H, a synthesis route of a symmetric infrared absorber is shown, and a methylating agent is used as an alkylating agent.

  Overall, in Scheme 1, the flavone or flavone derivative (1) is dissolved in a solvent, and the alkylating agent solution is added dropwise at room temperature (for example, 25 ° C.) and in a nitrogen atmosphere, and stirred while heating under reflux. Reaction is performed to obtain reaction mixture 1. An aqueous solution of an ionic compound (perchloric acid is used in Scheme 1) is added to the resulting reaction mixture 1, and the precipitated crystals are collected by filtration, washed with water, and intermediate (2) is obtained. obtain. The obtained intermediate (2) and croconic acid are dispersed in alcohol, pyridine is added, and the mixture is heated and refluxed with stirring to obtain a reaction mixture 2. The resulting reaction mixture 2 is allowed to cool and then collected by filtration and purified by chromatography to obtain compound (3) (an infrared absorber represented by general formula (I)).

In addition, when synthesizing an asymmetric infrared absorber, for example, two kinds of intermediates (2) are used. That is, the bonding position of ^{R 1} and ^{R 2, R 1} and ^{R 2} represents group number represented by the n1 and n2, of at least one of using two different kinds of intermediate (2).

Next, a synthesis route of an infrared absorber different from the infrared absorber obtained by the synthesis route shown in Scheme 1 is shown in Scheme 2. However, in Scheme 2, in general formula (I), X = sulfur atom, R ¹¹ = R ¹² (denoted as R ³ ), R ²¹ = R ²² (denoted as R ⁴ ), n11 = n12 (denoted as n3) , N21 = n22 (denoted as n4), R ³¹ = R ³² = H, a synthesis route of a symmetric infrared absorber is shown, and a methylating agent is used as an alkylating agent.

Phosphoric acid was added to diphosphorus pentoxide, stirred at room temperature (for example, 25 ° C.), further heated and stirred. Add thiophenol derivative (4) and stir. Subsequently, ethyl benzoyl acetate (5) is gradually added, and after the addition, the reaction is allowed to stir. Then cool to room temperature and add ice water. The precipitated solid is extracted with ethyl acetate, the separated organic phase is washed with water, dried over anhydrous sodium sulfate and concentrated, and the concentrated compound is purified by column chromatography to obtain intermediate (6). The intermediate (6) is dissolved in a solvent, and an alkylating agent solution is added dropwise under the conditions of room temperature and nitrogen atmosphere, and the mixture is reacted with stirring under heating to reflux to obtain a reaction mixture 2. An aqueous solution of an ionic compound (perchloric acid is used in Scheme 2) is added to the obtained reaction mixture 2, and the precipitated crystals are collected by filtration and washed with water to obtain intermediate (7). obtain.
And operation similar to the case where X is an oxygen atom is performed, and the compound (8) (infrared absorber represented by general formula (I)) in case X is a sulfur atom is obtained.

In addition, when synthesizing an asymmetrical infrared absorber, for example, two kinds of intermediates (7) are used. That is, the bonding positions of ^{R 3} and ^{R 4,} groups represented by ^{R 3} and ^{R 4,} the number represented by the n3 and n4, of at least one of using two different kinds of intermediate (7).

Here, the alkylating agent used in the synthesis of the infrared absorber is a compound that alkylates a ketone. Examples of the alkylating agent include methyl magnesium iodide (CH ₃ MgI), methyl magnesium bromide (CH ₃ MgBr), methyl lithium (CH ₃ Li), and ethyl magnesium bromide (C ₂ H ₅ MgBr). It is done.
Examples of the ionic compound include perfluoro acid, tetrafluoroboric acid, trifluoromethanesulfonic acid, ammonium bromide, and the like.

  The maximum absorption wavelength in the tetrahydrofuran (THF) solution of the infrared absorber represented by the general formula (I) is preferably in the range of 860 nm to 1200 nm, preferably in the range of 880 nm to 1200 nm, and more preferably 900 nm to 1150 nm. The following ranges are more desirable.

The molar extinction coefficient at the maximum absorption wavelength in the tetrahydrofuran (THF) solution of the infrared absorber represented by the general formula (I) is 1 × 10 ⁴ Lmol ⁻¹ cm ⁻¹ or more and 1 × 10 ⁶ Lmol ⁻¹ cm ^−1. The following is preferable, and 5 × 10 ⁴ Lmol ⁻¹ cm ⁻¹ or more and 1 × 10 ⁶ Lmol ⁻¹ cm ⁻¹ or less is desirable, and 1 × 10 ⁵ Lmol ⁻¹ cm ⁻¹ or more is 1 × 10 ⁶ Lmol ⁻¹ cm ⁻¹ or more. The following is more desirable.

  The content of the infrared absorber represented by the general formula (I) is desirably 0.05% by mass or more and 10% by mass or less, and 0.1% by mass or more and 5% by mass with respect to the total mass of the toner particles. It is more desirable that the content be 0.2% by mass or more and 3% by mass or less.

The infrared absorbent represented by the general formula (I) is preferably present in the toner in a molecular dispersed state, not in a solid dispersed state.
When the infrared absorber represented by the general formula (I) is present in the toner in an aggregated state, the mass average particle size is preferably 10 nm to 500 nm, preferably 10 nm to 300 nm, and preferably 10 nm to 200 nm. More desirable.

  The infrared light absorber represented by the general formula (I) is a known infrared light in addition to the above infrared absorber within a range in which the color of the toner of the present embodiment is effective in suppressing dust. An absorbent may be used. Known infrared absorbers include, for example, cyanine compounds, merocyanine compounds, benzenethiol metal complexes, mercaptophenol metal complexes, aromatic diamine metal complexes, diimonium compounds, aminium compounds, nickel complex compounds, phthalocyanine compounds, anthraquinones. Compounds, naphthalocyanine compounds, croconium compounds and the like can be used.

Specific examples of known infrared light absorbers include nickel metal complex infrared light absorbers (manufactured by Mitsui Chemicals, Inc .: SIR-130, SIR-132), bis (dithiobenzyl) nickel (manufactured by Midori Chemical Co., Ltd .: MIR). -101), bis [1,2-bis (p-methoxyphenyl) -1,2-ethylenedithiolate] nickel (manufactured by Midori Chemical Co., Ltd .: MIR-102), tetra-n-butylammonium bis (cis-1, 2-diphenyl-1,2-ethylenedithiolate) nickel (manufactured by Midori Chemical Co., Ltd .: MIR-1011), tetra-n-butylammonium bis [1,2-bis (p-methoxyphenyl) -1,2-ethylenedithio Rate] Nickel (Midori Chemical Co., Ltd .: MIR-1021), bis (4-tert-1,2-butyl-1,2-dithiophenolate) nickel-teto -N-butylammonium (manufactured by Sumitomo Seika Co., Ltd .: BBDT-NI), cyanine-based infrared light absorbers (manufactured by Fujifilm: IRF-106, IRF-107), cyanine-based infrared light absorbers (Yamamoto Kasei Co., Ltd.) YKR2900), aminium, diimonium-based infrared absorber (manufactured by Nagase Chemtech: NIR-AM1, IM1), imonium compound (manufactured by Nippon Carlit: CIR-1080, CIR-1081), aminium compound (Nippon Carlit) Manufactured: CIR-960, CIR-961), anthraquinone compound (Nippon Kayaku Co., Ltd .: IR-750), aminium compound (Nippon Kayaku Co., Ltd .: IRG-002, IRG-003, IRG-003K), polymethine Compounds (Nippon Kayaku Co., Ltd .: IR-820B), diimonium compounds (Nippon Kayaku Co., Ltd .: IRG-02) , IRG-023), dian compound (Nippon Kayaku Co., Ltd .: CY-2, CY-4, CY-9), soluble phthalocyanine (Nippon Shokubai Co., Ltd .: TX-305A), naphthalocyanine (Yamamoto Kasei Co., Ltd .: YKR5010) , Manufactured by Sanyo Dye Co., Ltd .: Sample 1), inorganic material system (manufactured by Shin-Etsu Chemical Co., Ltd .: ytterbium UU-HP, manufactured by Sumitomo Metals Co., Ltd .: indium tin oxide), and the like.
Among these, a diimonium compound or a croconium compound is preferable.

[Binder resin]
The binder resin is not particularly limited, and a known binder resin may be used. The main component of the binder resin is a copolymer of styrene and acrylic acid or methacrylic acid, polyvinyl chloride, phenol resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyolefin resin, polyurethane resin. Polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral resin, terpene resin, coumarone indene resin, petroleum resin, polyether polyol resin and the like are used alone or in combination.
The binder resin is preferably a polyester resin or a polyolefin resin, and more preferably a polyester resin or a norbornene polyolefin resin, from the viewpoints of durability and translucency. Moreover, a polyester resin is suitable from the viewpoint of generating less gas due to resin decomposition during light irradiation.
The polyester resin is obtained by condensation polymerization of a carboxylic acid component and an alcohol component. Specifically, a divalent or trivalent or higher carboxylic acid and a divalent or trivalent or higher alcohol component are used. .

  Examples of the carboxylic acid component include terephthalic acid, isophthalic acid, phthalic acid, and anhydrides thereof. Of these, terephthalic acid or isophthalic acid is preferred. These carboxylic acid components may be used alone or in combination of two or more.

  Examples of other carboxylic acid components include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid and the like. Furthermore, n-butyl succinic acid, n-butenyl succinic acid, isobutyl succinic acid, isobutenyl succinic acid, n-octyl succinic acid, n-octenyl succinic acid, n-dodecyl succinic acid, n-dodecenyl succinic acid, isododecyl succinic acid, Examples thereof also include alkyl or alkenyl succinic acids such as isododecenyl succinic acid, anhydrides of these acids, lower alkyl esters having 1 to 5 carbon atoms, and other divalent carboxylic acids.

Moreover, in order to bridge | crosslink a polyester resin, a trivalent or more carboxylic acid component can also be used as another carboxylic acid component.
Examples of the trivalent or higher carboxylic acid component include 1,2,4-benzenetricarboxylic acid, 1,3,5-benzenetricarboxylic acid, other polycarboxylic acids, and anhydrides thereof.

  Examples of the alcohol component include bisphenol A alkylene oxide adducts. In the polyester resin, usually, 80 mol% or more of the alcohol component is composed of a bisphenol A alkylene oxide adduct. The content of the bisphenol A alkylene oxide adduct is desirably 90 mol% or more, more desirably 95 mol% or more.

  Examples of the bisphenol A alkylene oxide adduct include polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) -2,2-bis (4- Hydroxyphenyl) propane, polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, poly Oxypropylene (2.0) -polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, etc. Is mentioned. These compounds may be used alone or in combination of two or more.

If desired, other alcohol components may be used in combination with the bisphenol A alkylene oxide adduct.
Examples of other alcohol components include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1 , 5-pentanediol, diols such as 1,6-hexanediol, bisphenol A, hydrogenated bisphenol A and the like.

  In addition, trihydric or higher alcohols are also suitable as other alcohol components. Examples of such trivalent or higher alcohol components include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butane. Examples include triol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, and the like.

  Furthermore, in the reaction for synthesizing the polyester resin, an esterification catalyst such as zinc oxide, stannous oxide, dibutyltin oxide, dibutyltin dilaurate, titanium or the like may be used in order to promote the synthesis reaction.

  The glass transition temperature (Tg) of the binder resin is preferably in the range of 50 ° C. or higher and 70 ° C. or lower.

(Coloring agent)
As the colorant, known pigments, dyes and the like are used.
Specifically, the following are selected and used corresponding to the color of the toner.
In the cyan toner, as the colorant, for example, C.I. I. Pigment Blue 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 13, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 17, 17, 23, 60, 65, 73, 83, 180, C.I. I. Vat cyan 1, 3 and 20, etc., bitumen, cobalt blue, alkali blue lake, phthalocyanine blue, metal-free phthalocyanine blue, partially chlorinated products of phthalocyanine blue, fast sky blue, indanthrene blue BC cyan pigment, C.I. I. Examples include cyan dyes such as solvent cyan 79 and 162.

  In the magenta toner, as the colorant, for example, C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 49, 70, 51, 52, 53, 54, 55, 57, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90 112, 114, 122, 123, 163, 184, 185, 202, 206, 207, 209, 238, etc., pigment violet 19 magenta pigments, C.I. I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 30, 49, 81, 82, 83, 84, 100, 109, 121, C . I. Disper thread 9, C.I. I. Basic Red 1, 2, 9, 9, 13, 14, 15, 17, 17, 18, 22, 23, 24, 27, 29, 32, 34, the same Magenta dyes such as 35, 36, 37, 38, 39, 40, etc., Bengala, cadmium red, red lead, mercury sulfide, cadmium, permanent red 4R, risol red, pyrazolone red, watching red, calcium Examples include salt, lake red D, brilliant carmine 6B, eosin lake, rotamin lake B, alizarin lake, brilliant carmine 3B.

  In the yellow toner, as the colorant, for example, C.I. I. Pigment yellow 2, 3, 15, 16, 17, 74, 93, 97, 128, 155, 180, 185, 139, and the like.

In the black toner, examples of the colorant include carbon black, activated carbon, titanium black, magnetic powder, Mn-containing nonmagnetic powder, and nigrosine dye.
Alternatively, yellow, magenta, cyan, red, green, and blue pigments may be mixed to form black toner.

The content of the colorant is preferably in the range of 2% by mass to 15% by mass, and more preferably in the range of 3% by mass to 7% by mass with respect to the total mass of the toner particles.
In particular, the content of the colorant is preferably in the range of 0.5% by mass to 25% by mass with respect to the total mass of the toner particles, and more preferably in the range of 1% by mass to 15% by mass. desirable.

(Other additives)
In order to further improve the toner fixability, the toner particles may contain a charge control agent and a release agent as other additives.
Examples of the charge control agent include a positive charge property and a negative charge property charge control agent.
Examples of positively chargeable charge control agents include nigrosine dyes, quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and the like. Onium salts such as phosphonium salts and lake pigments thereof; triphenylmethane dyes; metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide and dicyclohexyltin oxide; diorganotin borates such as dibutyltin borate Guanidine compounds, imidazole compounds, aminoacrylic resins and the like.

Examples of negatively chargeable charge control agents include trimethylethane dyes, metal complexes of salicylic acid, metal complexes of benzyl acid, copper phthalocyanine, perylene, quinacridone, azo pigments, metal complex azo dyes, azochrome complexes Examples include heavy metal-containing acid dyes such as calixarene type phenolic condensates, cyclic polysaccharides, resins containing carboxyl groups and sulfonyl groups, resins containing carboxyl groups or sulfonyl groups, and the like.
As the charge control agent, only one kind may be used alone, or two or more kinds may be mixed and used.

  Examples of the release agent include ester wax, polyethylene, polypropylene, or a copolymer of polyethylene and polypropylene, polyglycerin wax, microcrystalline wax, paraffin wax, carnauba wax, sazol wax, montanic ester wax, deacidified carnauba wax. , Unsaturated fatty acids such as palmitic acid, stearic acid, montanic acid, brandic acid, eleostearic acid, valinalic acid, stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnauvyl alcohol, ceryl alcohol, melyl alcohol, or even longer Saturated alcohols such as long-chain alkyl alcohols having a chain alkyl group; polyhydric alcohols such as sorbitol; linoleic acid amide, oleic acid amide, laurin Fatty acid amides such as amides; Saturated fatty acid bisamides such as methylenebisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, hexamethylene bisstearic acid amide, ethylene bisoleic acid amide, hexamethylene bisoleic acid amide Unsaturated fatty acid amides such as N, N′-dioleyl adipic acid amide and N, N′-dioleyl sebacic acid amide; m-xylene bisstearic acid amide, N, N′-distearyl isophthalic acid amide and the like Aromatic bisamides; Fatty acid metal salts such as calcium stearate, calcium laurate, zinc stearate, magnesium stearate (generally called metal soap); aliphatic hydrocarbon waxes such as styrene and acrylic acid Vinyl monomer Fatty acids with polyhydric alcohols partial esters of behenic acid monoglyceride; grafted allowed the waxes using methyl ester compounds having hydroxyl groups obtained by hydrogenation or the like of the vegetable oil and the like.

  These release agents may be used alone or in combination of two or more. The content of the release agent in the toner is preferably in the range of 0.1% by mass to 10% by mass, and in the range of 0.5% by mass to 4% by mass with respect to the total mass of the toner particles. Is more desirable.

-External additive-
Next, the external additive that can be attached to the surface of the toner particles will be described.
By attaching the external additive to the toner particles, the fluidity of the toner particles can be improved, stickiness of the toner particles can be suppressed, and aggregation of the toner particles can be suppressed.

  External additives include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, oxidation Examples thereof include inorganic particles such as cerium, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. Further, resin particles such as fluororesin and silicone resin, and higher fatty acid metal salts represented by zinc stearate may be used.

  The content of the external additive in the toner is desirably in the range of 0.01% by mass to 5% by mass with respect to the total mass of the toner particles, and is 0.01% by mass to 2.0% by mass. A range is desirable.

(Toner production method)
The toner according to the exemplary embodiment can be manufactured using, as a raw material, at least a component that includes at least the infrared absorbent represented by the general formula (I) and the binder resin. Specifically, for example, it can be produced by externally adding an external additive after preparing toner particles containing at least an infrared absorber represented by the general formula (I) and a binder resin.

  For example, the toner particles may be prepared by pulverizing and classifying the resin lump in which each of the above raw materials is dispersed, a polymerization method in which monomers are polymerized while taking in the raw materials to produce particles, or emulsion aggregation / unification. Manufactured by the law.

  When producing toner particles by a mechanical pulverization method, other additives (for example, a colorant) are mixed together with the infrared absorber represented by the general formula (I) and a binder resin to obtain a mixture. The obtained mixture is melt-kneaded using a kneader, an extruder or the like. Further, the melt-kneaded material is coarsely pulverized and then finely pulverized by a jet mill or the like, and toner particles having a target particle diameter are obtained by an air classifier.

In the case of producing toner particles by the emulsion aggregation / unification method, a raw material dispersion in which each component constituting the toner particles is dispersed in an aqueous dispersion is prepared (emulsification step). Specifically, a dispersion liquid in which binder resin particles are dispersed (hereinafter referred to as “resin particle dispersion liquid”), an infrared absorbent dispersion liquid in which an infrared absorbent is dispersed, and various other types used as necessary. A dispersion liquid (colorant dispersion liquid or the like) is mixed to prepare a raw material dispersion liquid.
Next, toner particles are obtained through an aggregated particle forming step of aggregating the particles in the raw material dispersion to form aggregated particles and a fusion step of fusing the aggregated particles.
In addition, when producing a so-called core-shell structure type toner having core particles and a shell layer covering the core particles, the resin particle dispersion is added to the raw material dispersion after the aggregated particle formation step. Then, a resin layer is attached to the surface of the agglomerated particles that become core particles when the toner is formed, and a coating layer forming step is performed to form a coating layer that becomes a shell layer when the toner is formed, and then a fusion step is performed. carry out. In addition, the resin component used for a coating layer formation process may be the same as that of the resin component which comprises a core particle, or may differ.

The toner particles obtained by the above method preferably have a volume average particle diameter D _{50v in} the range of 3 μm to 15 μm, and more preferably in the range of 3 μm to 10 μm.

  When external additives are externally added to the toner particles, the toner particles and the external additive may be added to a mixer such as a Henschel mixer and mixed sufficiently.

(Use)
The toner according to the exemplary embodiment may be a light fixing toner or a heat fixing toner. In addition, the toner according to the exemplary embodiment may be a color toner containing a colorant, or may be a transparent toner (so-called invisible toner) that does not contain a colorant. Here, the invisible toner is a toner that forms an image to be decoded (read) using invisible light such as infrared rays, and is fixed as a toner image on a recording medium (for example, paper). Means a toner that is difficult to be visually recognized (ideally not recognized at all).
The invisible toner may contain a colorant as long as the addition amount is not recognized as being present (for example, 1% by mass or less).

<Electrostatic image developer>
The electrostatic charge image developer containing the toner according to the exemplary embodiment (hereinafter sometimes referred to as “developer”) is a one-component developer composed of the toner or a two-component developer containing a carrier and the toner. Any of the agents may be used.
In the two-component developing method using a two-component developer, the toner and the carrier are brought into contact with each other, the toner is attached to the carrier using triboelectric charging, and the toner is further guided to the latent image portion for development. The law is representative.

Examples of the two-component developer carrier include a resin-coated carrier having a resin coating layer containing a conductive material and a crosslinkable resin on the surface of the core material.
As the carrier core material, known magnetite, ferrite, iron powder, glass beads and the like are used. The carrier coating agent is not particularly limited, but a silicone resin system is particularly desirable.

Specific examples of the conductive material include metals such as gold, silver and copper; carbon black; a conductive metal oxide simple substance such as titanium oxide and zinc oxide; titanium oxide, zinc oxide, aluminum borate and potassium titanate. , Tin oxide, indium tin oxide and the like, and a composite system in which the surface of a particle is coated with a conductive metal oxide. Note that the conductive particles preferably have conductivity with a volume resistivity of less than 10 ⁷ Ω · cm, for example.
Examples of the crosslinkable resin include a crosslinkable fluorine-based resin, an epoxy resin, and a crosslinkable silicone resin. Among these, an epoxy resin and a crosslinkable silicone resin are desirable, and as the crosslinkable silicone resin, a crosslinkable straight silicone resin and a fluorine-modified silicone resin are desirable.
The resin coating layer preferably has an outermost surface made of a crosslinkable resin from the viewpoint of suppressing the external additive of the toner particles from being buried in the carrier surface and changing the external additive structure of the toner particles.

In general, the average particle size of the core material of the carrier is desirably 10 μm or more and 100 μm or less, and more desirably 20 μm or more and 80 μm or less.
The mixing ratio of the toner and the carrier in the two-component developer (toner: carrier) is preferably in the range of 1: 100 to 30: 100 on a mass basis, and in the range of 3: 100 to 20: 100. Is more desirable.

<Image Forming Apparatus and Image Forming Method>
Next, an image forming apparatus and an image forming method according to this embodiment using the toner according to this embodiment will be described.
The image forming apparatus according to the present embodiment includes an electrostatic latent image holding member, a charging unit that charges the surface of the electrostatic latent image holding member, and an electrostatic latent image on the surface of the charged electrostatic latent image holding member. The electrostatic latent image forming means for forming the electrostatic latent image developer according to the present embodiment and the electrostatic latent image formed on the surface of the electrostatic latent image holding member are stored in the electrostatic image developer. Development means for forming a toner image by developing, a transfer means for transferring the toner image to a recording medium, and a fixing means for fixing the toner image transferred to the recording medium.

  According to the image forming apparatus according to the present embodiment, the charging step of charging the electrostatic latent image holding member and the electrostatic latent image forming step of forming an electrostatic latent image on the surface of the charged electrostatic latent image holding member. In addition, the electrostatic charge image developer according to the exemplary embodiment is accommodated, and the electrostatic latent image formed on the surface of the electrostatic latent image holding member is developed with the electrostatic charge image developer to form a toner image. The image forming apparatus includes a developing step, a transfer step for transferring the toner image to a recording medium, and a fixing step for fixing the toner image transferred to the recording medium.

  Image formation in the image forming apparatus according to the present embodiment is performed as follows when an electrophotographic photosensitive member (hereinafter referred to as “photosensitive member”) is used as the electrostatic latent image holding member. First, the surface of the photoconductor is charged by a corotron charger, a contact charger or the like and then exposed to form an electrostatic latent image. Next, the toner is attached to the electrostatic latent image in contact with or in proximity to a developing roll having a developer layer formed on the surface, thereby forming a toner image on the photoreceptor. The formed toner image is transferred onto the surface of a recording medium such as paper using a corotron charger or the like. Further, the toner image transferred to the surface of the recording medium is fixed by a fixing device, and an image is formed on the recording medium.

As the photoreceptor, generally, an inorganic photoreceptor such as amorphous silicon or selenium, or an organic photoreceptor using polysilane, phthalocyanine or the like as a charge generation material or a charge transport material is used. In particular, from the viewpoint of abrasion resistance, the photosensitive member is an amorphous silicon photosensitive member for an inorganic photosensitive member, and a resin layer having a crosslinked structure such as a melamine resin, a phenol resin, or a silicone resin on the outermost layer for an organic photosensitive member. It is desirable that the photoreceptor has a so-called overcoat layer.
When a positively chargeable toner is used as the toner, generally, an inorganic photoreceptor represented by amorphous silicon (sometimes abbreviated as “a-Si”) is used, and when a negatively charged toner is used, In general, an organic photoconductor (also referred to as OPC) is used.

  In the image forming apparatus and the image forming method in the present embodiment, the toner image may be fixed to the recording medium by light fixing by light irradiation or pressure / heat fixing using a heating member typified by a heating roll. Furthermore, pressurization / heat-fixing using a heating member and light-fixing by light irradiation may be used in combination.

As a fixing means for adopting a light fixing method in which a toner image is fixed by irradiating light, any means for fixing by light may be used, and a light fixing device (flash fixing device) is used.
Examples of the light source used in the light fixing device include a normal halogen lamp, a mercury lamp, a flash lamp, and an infrared laser.

As the heating member, a heating roll fixing device, an oven fixing device or the like is desirably used.
As the heating roll fixing device, generally, a heating roll type fixing device in which a pair of fixing rolls are pressed against each other is used. As a pair of fixing rolls, a heating roll and a pressure roll are provided facing each other, and a nip is formed by pressure contact. The heating roll has a metal hollow core with a heater lamp inside, and a surface layer made of an oil- and heat-resistant elastic body layer (elastic layer) and a fluororesin, etc. are sequentially formed. Accordingly, an oil- and heat-resistant elastic body layer and a surface layer are sequentially formed on a metal hollow core metal core having a heater lamp inside. The toner image is fixed by passing a recording medium on which the toner image is formed through a nip region formed by the heating roll and the pressure roll.

Among these, the fixing unit is preferably an apparatus that irradiates an infrared laser that irradiates a laser beam of 860 nm or more. This is because this infrared laser is excellent in energy conversion efficiency, that is, light emission efficiency, and it is easy to reduce energy required for fixing means.
In addition, the infrared absorbent represented by the general formula (I) has a maximum absorption wavelength in the wavelength region of 860 nm or more, and the absorption efficiency of the infrared laser light by the infrared absorbent is improved, so that It becomes easy to reduce the addition amount of the infrared absorber to be added.

  Hereinafter, an example of the image forming apparatus according to the present embodiment will be described, but the present invention is not limited thereto. In addition, the main part shown to a figure is demonstrated and the description is abbreviate | omitted about others.

  FIG. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present embodiment. The image forming apparatus shown in FIG. 1 is one that forms a toner image with toner obtained by adding black to three colors of cyan, magenta, and yellow.

  The image forming apparatus shown in FIG. 1 feeds the recording medium P wound in a roll shape by a paper feed roller 328, and on the one side of the recording medium P fed in this way, the recording medium P is fed upstream in the feeding direction. Four image forming units 312 (black (K), yellow (Y), magenta (M), cyan (C)) are provided in parallel from the side toward the downstream side. A light fixing type fixing device 326 is provided on the downstream side.

The black image forming unit 312K is a known electrophotographic image forming unit. Specifically, a charging unit 316K, an exposure unit 318K, a developing unit 320K, and a cleaner 322K are provided around the photosensitive member 314K, and a transfer unit 324K is provided via the recording medium P. The same applies to the other yellow, magenta, and cyan image forming units 312Y, 312M, and 312C.
When used for monochrome printing, only black (K) may be provided as the image forming unit 312.

  In the image forming apparatus shown in FIG. 1, toner images are sequentially transferred by a known electrophotographic method onto each recording medium P 312K, 312Y, 312M, and 312C on the recording medium P drawn from the roll state. The image is fixed by the fixing device 326 to form an image. A heating roll pair (not shown) for fixing the toner image to the recording medium P by pressurization and heating with the recording medium P interposed may be provided at a position where the fixing device 326 is installed. By providing a heating device such as a heater in the roll, the heating roll pair is heated, and when the toner image comes into contact with the heating roll pair, the toner image is melted and fixed on the recording medium P.

  Next, an image forming apparatus according to another embodiment will be described. FIG. 2 is a schematic configuration diagram illustrating an example of an image forming apparatus according to another embodiment.

  The image forming apparatus shown in FIG. 2 is a quadruple tandem color image forming apparatus. The image forming apparatus shown in FIG. 2 is a first to first electrophotographic method that outputs yellow (Y), magenta (M), cyan (C), and black (K) images based on color-separated image data. Fourth image forming units 10Y, 10M, 10C, and 10K (image forming means) are provided. These image forming units (hereinafter simply referred to as “units”) 10Y, 10M, 10C, and 10K are juxtaposed in parallel in the horizontal direction. The units 10Y, 10M, 10C, and 10K may be process cartridges that are detachable from the main body of the image forming apparatus.

Above each of the units 10Y, 10M, 10C, and 10K, an intermediate transfer belt 20 as an intermediate transfer member is extended through each unit. The intermediate transfer belt 20 is provided by being wound around a driving roller 22 and a support roller 24 that are in contact with the inner surface of the intermediate transfer belt 20 that are spaced apart from each other in the left to right direction in FIG. The vehicle travels in the direction toward the unit 10K. The support roller 24 is urged away from the drive roller 22 by a spring or the like (not shown), and tension is applied to the intermediate transfer belt 20 wound around both. Further, an intermediate transfer member cleaning device 30 is provided on the side of the image carrier of the intermediate transfer belt 20 so as to face the driving roller 22.
Further, each of the developing devices (developing means) 4Y, 4M, 4C, and 4K of the units 10Y, 10M, 10C, and 10K includes yellow, magenta, cyan, and black contained in the toner cartridges 8Y, 8M, 8C, and 8K. The four colors of toner are supplied.

  Since the first to fourth units 10Y, 10M, 10C, and 10K described above have the same configuration, here, the first unit that forms a yellow image disposed on the upstream side in the intermediate transfer belt traveling direction. 10Y will be described as a representative. Note that the second to fourth units are denoted by reference numerals with magenta (M), cyan (C), and black (K) instead of yellow (Y) in the same parts as the first unit 10Y. Description of 10M, 10C, 10K is omitted.

The first unit 10Y has a photoreceptor 1Y that functions as an image holding member. Around the photoreceptor 1Y, a charging roller 2Y that charges the surface of the photoreceptor 1Y, and an exposure apparatus 3 that forms an electrostatic latent image by exposing the charged surface with a laser beam 3Y based on the color-separated image signal. A developing device (developing means) 4Y for supplying the electrostatic latent image with charged toner to develop the electrostatic latent image, and a primary transfer roller 5Y (primary transfer) for transferring the developed toner image onto the intermediate transfer belt 20 Means), and a photoreceptor cleaning device (cleaning means) 6Y for removing toner remaining on the surface of the photoreceptor 1Y after the primary transfer with a cleaning blade.
The primary transfer roller 5Y is disposed inside the intermediate transfer belt 20, and is provided at a position facing the photoreceptor 1Y. Further, a bias power source (not shown) for applying a primary transfer bias is connected to each of the primary transfer rollers 5Y, 5M, 5C, and 5K. Each bias power source varies the transfer bias applied to each primary transfer roller under the control of a control unit (not shown).

Hereinafter, an operation of forming a yellow image in the first unit 10Y will be described. First, prior to the operation, the surface of the photoreceptor 1Y is charged by the charging roller 2Y.
A laser beam 3Y is output to the surface of the charged photoreceptor 1Y via the exposure device 3 in accordance with yellow image data sent from a control unit (not shown). The laser beam 3Y is applied to the photosensitive layer on the surface of the photoreceptor 1Y, whereby an electrostatic latent image of a yellow print pattern is formed on the surface of the photoreceptor 1Y.

  The electrostatic latent image formed on the photoreceptor 1Y in this way is rotated to the development position as the photoreceptor 1Y travels. Then, at this development position, the electrostatic latent image on the photoreceptor 1Y is converted into a visible image (developed image) by the developing device 4Y.

  For example, yellow toner is accommodated in the developing device 4Y. The yellow toner is triboelectrically charged by being agitated inside the developing device 4Y, and is held on a developer roll (developer holder) having a charge of the same polarity as the charged electric charge on the photoreceptor 1Y. ing. As the surface of the photoreceptor 1Y passes through the developing device 4Y, the yellow toner is electrostatically attached to the latent image portion on the surface of the photoreceptor 1Y, and the latent image is developed with the yellow toner. . The photoreceptor 1Y on which the yellow toner image is formed continues to run, and the toner image developed on the photoreceptor 1Y is conveyed to the primary transfer position.

When the yellow toner image on the photoreceptor 1Y is conveyed to the primary transfer, a primary transfer bias is applied to the primary transfer roller 5Y, and an electrostatic force from the photoreceptor 1Y toward the primary transfer roller 5Y acts on the toner image. Then, the toner image on the photoreceptor 1Y is transferred onto the intermediate transfer belt 20. The transfer bias applied at this time has a polarity opposite to that of the toner, and is controlled to about +10 μA by the control unit (not shown) in the first unit 10Y, for example.
On the other hand, the toner remaining on the photoreceptor 1Y is removed and collected by the cleaning device 6Y.

Further, the primary transfer bias applied to the primary transfer rollers 5M, 5C, and 5K after the second unit 10M is also controlled according to the first unit.
Thus, the intermediate transfer belt 20 onto which the yellow toner image has been transferred by the first unit 10Y is sequentially conveyed through the second to fourth units 10M, 10C, and 10K, and the toner images of the respective colors are superimposed and transferred in a multiple manner.

  The intermediate transfer belt 20 onto which the four color toner images have been transferred through the first to fourth units is arranged on the image transfer surface side of the intermediate transfer belt 20 and the support roller 24 in contact with the inner surface of the intermediate transfer belt 20. The secondary transfer roller (secondary transfer means) 26 is connected to a secondary transfer portion. On the other hand, the recording medium P is fed through a supply mechanism into a gap where the secondary transfer roller 26 and the intermediate transfer belt 20 are pressed against each other, and a secondary transfer bias is applied to the support roller 24. The transfer bias applied at this time has the same polarity as the polarity of the toner, an electrostatic force from the intermediate transfer belt 20 toward the recording medium P is applied to the toner image, and the toner image on the intermediate transfer belt 20 is transferred to the recording medium. Transferred onto P. Note that the secondary transfer bias at this time is determined according to the resistance detected by a resistance detecting means (not shown) for detecting the resistance of the secondary transfer portion, and is voltage-controlled.

Thereafter, the recording medium P is sent to a heating roll type fixing device (fixing means) 28, where the toner image is heated, and the color-superposed toner image is melted and fixed on the recording medium P. By providing a heating device such as a heater in the heating roll, the heating roll pair is heated, and when the toner image comes into contact with the heating roll pair, the toner is melted and fixed on the recording medium P. The heating roll type fixing device (fixing means) 28 may be replaced with a fixing device (light source) for light fixing.
The recording medium P on which the color image has been fixed is unloaded to the discharge unit, and a series of color image forming operations is completed.
The image forming apparatus exemplified above is configured to transfer the toner image to the recording medium P via the intermediate transfer belt 20, but is not limited to this configuration, and the toner image is directly transferred from the photoconductor. It may be a structure that is transferred to a recording sheet.

<Process cartridge>
The process cartridge according to the present embodiment stores a developer and develops an electrostatic latent image formed on the surface of the electrostatic latent image holding member with the electrostatic image developer to form a toner image. And is detachable from the image forming apparatus. The developer according to the above embodiment is applied as the developer.

<Toner cartridge>
Next, the toner cartridge according to this embodiment will be described. The toner cartridge according to the present exemplary embodiment is a toner cartridge that stores toner and is detachable from the image forming apparatus. As the toner, the toner according to the present embodiment is applied.

  The image forming apparatus shown in FIG. 2 is an image forming apparatus having a configuration in which the toner cartridges 8Y, 8M, 8C, and 8K are attached and detached. The developing devices 4Y, 4M, 4C, and 4K each have their respective developing devices (colors). ) And a toner supply pipe (not shown). Further, when the amount of toner stored in the toner cartridge is low, the toner cartridge is replaced.

<New croconium compound>
The novel croconium compound according to this embodiment is a compound represented by the general formula (II) or (III) described above. The novel croconium compound according to the present embodiment is a compound that has less visible light absorption and is useful as an infrared absorber compared to the known comparative compounds H-01 and H-02.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. Unless otherwise specified, “part” and “%” are based on mass.

<Synthesis of infrared absorber>
(Synthesis of D-01)
According to the following scheme A, exemplary compound D-01 was synthesized.
Dissolve 2.22 g of flavone in 12 ml of THF, drop 15 ml of 1M THF solution of methylmagnesium iodide in a nitrogen atmosphere at room temperature (25 ° C.), and stir for 3 hours with heating under reflux to obtain a reaction mixture. It was. The obtained reaction mixture was added little by little to 130 ml of an aqueous solution of 10% perchloric acid. The precipitated crystals were collected by filtration and washed with water to obtain 3.0 g of intermediate (2a). (Yield 93.5%). Intermediate (2a) (0.64 g) and croconic acid (0.13 g) were dispersed in methanol (4 ml), pyridine (0.1 g) was added, and the mixture was heated to reflux for 3 hours with stirring. The reaction mixture was allowed to cool, then removed by filtration, and purified by column chromatography to obtain 0.18 g of a solid of exemplary compound D-01 (2 stage yield: 63%).
Identification of the infrared absorbent was carried out on the obtained solid by 1H-NMR spectrum and mass spectrum. As a result, it was confirmed that the obtained solid had a molecular structure represented by D-01. Shows the identification data below; IH-NMR spectrum _{(CDCl 3): 7.0~8.4 (16H} ), 8.5 (m, 4H), and 9.0 (m, 2H), and mass spectra ( FD): m / z = 546 (M +, 100%).
The maximum absorption wavelength of D-01 in the THF solution was ₉₉₅ nm, and the molar extinction coefficient ε ₉₉₅ at the maximum absorption wavelength in the THF solution of D-01 was 1.4 × 10 ⁵ Lmol ⁻¹ cm ⁻¹ . .
The identification of the infrared absorbent, the calculation of the maximum absorption wavelength of the infrared absorbent, and the mass average particle diameter of the infrared absorbent will be described later. The same applies hereinafter.

(Synthesis of D-03)
Exemplified compound D-03 was obtained in the same manner as in the synthesis of D-01 except that 2.22 g of flavone was changed to 2.72 g of benzoflavone.
The infrared absorber was identified by 1H-NMR spectrum and mass spectrum of the obtained solid. As a result, it was confirmed that the obtained solid had a molecular structure represented by D-03. Shows the identification data below; IH-NMR spectrum _{(CDCl 3): 7.2~8.1 (16H} ), 8.2~8.4 (m, 2H), 8.4~8.6 (4H) 8.7-8.8 (d, 2H), 9.4 (m, 2H), and mass spectrum (FD): m / z = 646 (M +, 100%).
The maximum absorption wavelength of the THF solution of D-03 was ₁₀₀₂ nm, and the molar extinction coefficient ε ₁₀₀₂ at the maximum absorption wavelength in the THF solution of D-03 was 1.0 × 10 ⁵ Lmol ⁻¹ cm ⁻¹ .

(Synthesis of D-36)
Exemplified compound D-36 was synthesized according to the following scheme B.
10.5 mL of phosphoric acid was added to 19.5 g of diphosphorus pentoxide, stirred at room temperature (25 ° C.) for 10 minutes, and stirred at 95 ° C. for 20 minutes. 4-isopropylthiophenol 2.29g was added and stirred. Next, 2.88 g of ethyl benzoyl acetate was gradually added over 1 hour and 30 minutes, and after the addition, the reaction was stirred for 30 minutes. The mixture was cooled to room temperature (25 ° C.), 20 mL of ice water was added, the precipitated solid was extracted with ethyl acetate, the separated organic phase was washed with water, dried over anhydrous sodium sulfate, and then concentrated. Purification by chromatography gave 2.9 g of intermediate (6b). 1.12 g of the intermediate (6b) is dissolved in 8 ml of THF, and 12 ml of 1M THF solution of methylmagnesium iodide in a nitrogen atmosphere is added dropwise at room temperature (25 ° C.) and stirred for 3 hours under heating and refluxing to react. It was. The reaction mixture was added in small portions to 100 ml of an aqueous solution of 10% perchloric acid. The precipitated crystals were collected by filtration and washed with water to obtain 1.4 g of intermediate (7b). Intermediate (7b) (0.34 g) and croconic acid (0.06 g) were added with 4 ml of methanol and 0.1 g of pyridine, and the mixture was heated to reflux for 3 hours with stirring. The reaction mixture was allowed to cool, then removed by filtration, and purified by column chromatography to obtain 0.18 g of crystals of Exemplified Compound D-36 (3 steps yield 38%).
In addition, identification of the infrared absorber was performed by 1H-NMR spectrum and mass spectrum for the obtained crystals. As a result, it was confirmed that the obtained solid had a molecular structure represented by D-36. Shows the identification data below; IH-NMR spectrum _{(CDCl 3): 1.4 (d} , 12H), 3.2 (m, 2H), 7.4~7.8 (6H), 7.9~8 .2 (6H), 8.5 (m, 2H), 8.8 (m, 4H), 9.9 (br, 2H), and mass spectrum (FD): m / z = 662 (M +, 100%) ).
The maximum absorption wavelength of the THF solution of D-36 was ₁₁₀₁ nm, and the molar extinction coefficient ε ₁₁₀₁ at the maximum absorption wavelength in the THF solution of D-36 was 1.6 × 10 ⁵ Lmol ⁻¹ cm ⁻¹ .

(Synthesis of D-38)
Except that 2.88 g of ethyl benzoyl acetate was changed to 3.09 g of ethyl 4-methylbenzoyl acetate in the synthesis of D-36, a solid of exemplary compound D-38 was obtained.
The infrared absorber was identified by 1H-NMR spectrum and mass spectrum of the obtained solid. As a result, it was confirmed that the obtained solid had a molecular structure represented by D-38. Shows the identification data below; IH-NMR spectrum _{(CDCl 3): 1.4 (d} , 12H), 2.4 (s, 6H), 3.2 (m, 2H), 7.4~7.8 (6H), 7.9-8.2 (6H), 8.5 (m, 2H), 8.8 (m, 4H), 9.9 (br, 2H), and mass spectrum (FD): m / Z = 690 (M +, 100%).
The maximum absorption wavelength of the THF solution of D-38 was ₁₁₀₃ nm, and the molar extinction coefficient ε ₁₁₀₃ at the maximum absorption wavelength in the THF solution of D-38 was 1.6 × 10 ⁵ Lmol ⁻¹ cm ⁻¹ .

(Synthesis of H-01 and H-02)
The following comparative compounds H-01 and H-02 were synthesized by the method disclosed in JP-A-2001-11070.

<Evaluation of infrared absorber>
-Identification of infrared absorbers-
The infrared absorber was identified by 1H-NMR spectrum and mass spectrum. The 1H-NMR spectrum was obtained by measuring a CDCl ₃ solution of an infrared absorber with a nuclear magnetic resonance apparatus (UNITY-300 manufactured by Varian). For the mass spectrum, an infrared absorber was obtained using a mass spectrometer (JMS SX102 manufactured by JEOL Ltd.).

-Calculation of maximum absorption wavelength-
The maximum absorption wavelength of the infrared absorbent was calculated from the absorption spectrum obtained by measuring the absorption spectrum of the infrared absorbent in a tetrahydrofuran solution (U4100 manufactured by Hitachi, Ltd.).

-Particle measurement method-
The mass average particle size of the infrared absorbent is calculated by converting the mass average particle size based on the mass distribution from the volume distribution measured using a laser diffraction / scattering particle size distribution analyzer (LA-910, manufactured by Horiba, Ltd.). Asked.

<Example 1>
(Preparation of colored toner 1)
-Preparation of colored toner 1-
0.1 parts by mass of Exemplified Compound D-01 as an infrared absorber, 95 parts by mass of polyester resin (condensate of bisphenol-propylene oxide adduct and fumaric acid (manufactured by Kao)), and 500 parts by mass of THF are mixed. , Dissolved. The obtained solution was dropped into water under stirring conditions, and the resulting solid was collected by filtration and dried under reduced pressure to obtain a resin powder containing an infrared absorber. 5 parts by mass of pigment: Pigment Blue 15: 3 (manufactured by Dainichi Seika), 1 part by mass of charge control agent (CCA100, manufactured by Chuo Synthetic Chemical), and 0.5 part by mass of wax: NP105 (Mitsui Chemicals) Each was prepared as a colored toner component. The entire amount of the colored toner component was put into a Henschel mixer, premixed, and melt kneaded with an extruder. Next, the obtained mixture was cooled and solidified, then coarsely pulverized with a hammer mill, and further finely pulverized with a jet mill. The resulting fine powder was classified with an airflow classifier to obtain blue colored particles (colored toner particles) having a volume average particle size of 8.5 μm. Subsequently, 0.5 parts by mass of hydrophobic silica particles (trade name: H3004, manufactured by Clariant Japan Co.) are added to the obtained colored toner particles, and an external addition process is performed with a Henschel mixer to produce a colored toner 1. did.

-Production of Developer 1-
Colored toner 1 and silicone resin-coated carrier (particle size 50 μm) were mixed to prepare developer 1.

<Evaluation>
-Image formation-
Developer 1 is used by an image forming apparatus (manufactured by Fuji Xerox Co., Ltd., trade name: Docu Center Color 2220) equipped with a semiconductor laser having an exposure wavelength of 980 nm (BPC80C-980-02 manufactured by OCLARO) as a light source of the light fixing device. A fixed image was obtained on the paper. The irradiation energy of the semiconductor laser in forming a fixed image was set to 1.5 J / cm ² (however, in the calculation of the color difference ΔE, the irradiation energy was set to 1.0 J / cm ² ).

-Fixability evaluation (crease evaluation)-
The fixing property of the colored toner was determined by visual observation of the image, and in the case where a good image was obtained without image blurring, the following crease evaluation was performed. In the evaluation of the crease, the paper on which the fixed image obtained by the above image formation was formed was bent once, and the opened and folded image portion was wiped with cotton, and the degree of peeling of the image was expressed by a numerical value. Specifically, an image having a diameter of 20 mm with a single layer of colored toner is folded once, opened and lightly wiped with a cotton, and the white width of the image is expressed in μm as an index. The following are acceptable ranges. From the numerical value (crease value) of the crease evaluation, fixability was determined according to the following criteria.
A: A good fixed image is obtained and a crease value of 40 or less B: A good fixed image is obtained and exceeds a crease value of 40 C: Many portions are not fixed and a good fixed image cannot be obtained

-Evaluation of color drift (color difference △)-
First, in the image forming method described above, a fixed image with a color developer was formed on a sheet. Next, a developer is prepared using a colored toner obtained by removing the infrared absorber from the colored toner, and in the image forming method described above, instead of fixing with an optical fixing device, the paper on which the colored toner is transferred Was sandwiched between Teflon (registered trademark) sheets and passed through a pouch laminator (manufactured by Nippon GC Corporation, GLM2500, speed setting 1, temperature setting 120 ° C.) to obtain a fixed image.
Using a reflection spectral densitometer (x-rite 939, manufactured by X-Rite Co., Ltd.), the color of a fixed image of a colored toner containing an infrared absorber and a fixed image of a colored toner not containing an infrared absorber are evaluated. L1, a1, b1, L2, a2, and b2 in (1) were measured, and a color difference ΔE was calculated.
Formula (1): ΔE = {(L1-L2) ² + (a1-a2) ² + (b1-b2) ² } ^1/2
(In the formula (1), L, a, and b represent CIELAB color space L ^* value, a ^* value, and b ^* value, respectively. L2, a2, and b2 are fixed images of colored toners produced in each example. represents ^{L *} value, ^{a *} and ^{b *} values in, L1, a1 and b1 represent ^{L *} value, ^{a *} and ^{b *} values in the fixed image of colored toner excluding the infrared absorber.)
The color difference Δ was evaluated according to the following criteria.
A: Less than 4 B: 4 or more and less than 10 C: 10 or more

(Examples 2-6, Comparative Examples 1-4)
-Preparation of colored toners 2-6, 20-23-
Colored toners 2-6 and 20-23 were prepared in the same manner as colored toner 1 except that the type and amount of the infrared absorber were changed based on the description in Table 1. Further, in the same manner as in Example 1, the fixing properties and colors of the colored toners 2 to 6 and 20 to 23 were evaluated, and the evaluation results are summarized in Table 1 together with the type and addition amount of the infrared absorber.
In Table 1, “−” in the color drift evaluation indicates that the fixability is poor and the color drift cannot be evaluated. This is because the color can be visually confirmed.

(Example 7)
-Preparation of transparent toner 7-
0.2 parts by mass of Exemplified Compound D-01 as an infrared absorber, 100 parts by mass of polyester resin (condensate of bisphenol-propylene oxide adduct and fumaric acid (manufactured by Kao Corporation)) and 500 parts by mass of tetrahydrofuran are mixed. And dissolve. The obtained solution was dropped into water under stirring conditions, and the resulting solid was collected by filtration and dried under reduced pressure to obtain a resin powder containing an infrared absorber. 1 part by mass of a charge control agent (CCA100, manufactured by Chuo Synthetic Chemical) and 0.5 part by mass of wax: NP105 (Mitsui Chemicals) were prepared as transparent toner components in the obtained powder. The entire amount of the transparent toner component was put into a Henschel mixer, premixed, and melt kneaded with an extruder. Next, the obtained mixture was cooled and solidified, then coarsely pulverized with a hammer mill, and further finely pulverized with a jet mill. The obtained fine powder was classified with an airflow classifier to obtain blue colored particles (transparent toner particles) having a volume average particle diameter of 7.5 μm. Subsequently, 0.5 parts by mass of hydrophobic silica particles (trade name: H3004, manufactured by Clariant Japan Co., Ltd.) are added to the obtained transparent toner particles, and an external addition process is performed using a Henschel mixer to produce transparent toner 7. did.

-Production of developer 7-
Transparent toner 7 and silicone resin coated carrier (particle size 50 μm) were mixed to prepare developer 7.
Further, in the same manner as in Example 1, the fixing property and color dust of the transparent toner 7 were evaluated, and the evaluation results are summarized in Table 1 together with the type and addition amount of the infrared absorber.

(Comparative Example 5)
-Preparation of transparent toner 24-
The transparent toner 24 was produced in the same manner as the transparent toner 11 except that the type and addition amount of the infrared absorbent were changed based on the description in Table 1. Further, in the same manner as in Example 1, the fixing property and color dust of the transparent toner 24 were evaluated, and the evaluation results are summarized in Table 1 together with the type and addition amount of the infrared absorber.

In the developers using the colored toners, in Examples 1 to 6, good results were obtained in both fixability and color as compared with Comparative Examples 1 to 4.
Further, Examples 1 to 3 using Exemplified Compound D-01 obtained better results in both fixing property and color than Comparative Examples 1 to 3 using Comparative Compound H-01. Thus, although the exemplified compound D-01 has a structure similar to that of the comparative compound H-01, it has optical characteristics such as having a maximum absorption wavelength of 860 nm or longer on the long wavelength side and a high molar extinction coefficient. You can see that
Further, in Example 5 using Exemplified Compound D-36, better results in both fixability and color were obtained than Comparative Example 4 using Comparative Compound H-02. Thereby, the exemplary compound D-36 has a maximum absorption wavelength of 1101 nm with respect to the exposure wavelength of 980 nm for fixing, and the difference between the maximum absorption wavelength and the exposure wavelength compared to the maximum absorption wavelength of 966 nm of the comparative compound H-02. It can be seen that the absorption efficiency of the laser beam is higher than that of the comparative compound H-02, that is, the molar extinction coefficient at the exposure wavelength is high. Exemplified Compound D-36 has a lower absorption efficiency in the visible region than Exemplified Compound H-02 and exhibits an absorption spectrum shape having no absorption band in the visible region (for example, Exemplified Compound H-02). It can be seen that it has a sharper absorption spectrum shape.
Also in the developer using the transparent toner, in Example 7, good results were obtained in comparison with Comparative Example 5 in both fixability and color.

1Y, 1M, 1C, 1K Photoconductor 2Y, 2M, 2C, 2K Charging roller 3Y, 3M, 3C, 3K Laser beam 3 Exposure device 4Y, 4M, 4C, 4K Developing device 5Y, 5M, 5C, 5K Primary transfer Rollers 6Y, 6M, 6C, 6K Cleaning devices 8Y, 8M, 8C, 8K Toner cartridges 10Y, 10M, 10C, 10K Image forming unit 20 Intermediate transfer belt 22 Drive roller 24 Support roller 26 Secondary transfer roller 28 Fixing device 30 Intermediate transfer Body cleaning devices 312Y, 312M, 312C, 312K Image forming units 314Y, 34M, 314C, 314K, 314K Photoconductors 316Y, 316M, 316C, 316K, 316K Chargers 318Y, 318M, 318C, 318K, 318K Exposure means 320Y, 320M, 320C, 320K , 320K Developer 322Y, 322M, 322C, 322K, 322K Cleaner 324Y, 324M, 324C, 324K, 324K Transfer device 326 Fixing device 328 Paper feed roller

Claims (11)

An electrostatic image developing toner comprising a binder resin and an infrared absorber represented by the following general formula (I):

(In the general formula (I), R ¹¹ , R ¹² , R ²¹ and R ²² are each independently a halogen group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, or a substituted or unsubstituted group. Represents an alkoxy group, R ³¹ and R ³² each independently represent a hydrogen atom or an aliphatic group, n11 and n12 each independently represents an integer of 0 or more and 4 or less, and n21 and n22 each represents Independently represents an integer of 0 to 5. X represents an oxygen atom or a sulfur atom, and when n11 represents an integer of 2 to 4, a plurality of R ¹¹ are independently the same or different. In the case where n12 represents an integer of 2 or more and 4 or less, a plurality of R ¹² may be independently the same or different, and may be bonded to each other. A ring may be formed, n When 21 represents an integer of 2 or more and 5 or less, the plurality of R ²¹ may be independently the same or different and may be bonded to each other to form a ring, and n22 is an integer of 2 or more and 5 or less. A plurality of R ^{22 s} may be the same or different and may be bonded to each other to form a ring, provided that R ¹¹ and R ²¹ , R ¹¹ and R ²² , R ¹² And R ²¹ , and R ¹² and R ²² are not bonded to each other to form a ring.)   The toner for developing an electrostatic image according to claim 1, comprising a colorant.   The electrostatic charge image developing toner according to claim 1, wherein a maximum absorption wavelength of the infrared absorber is in a range of 860 nm to 1200 nm.   An electrostatic charge image developer comprising the electrostatic charge image developing toner according to claim 1.   A toner cartridge that accommodates the electrostatic image developing toner according to claim 1 and is detachable from an image forming apparatus.   5. A developing unit that stores the electrostatic image developer according to claim 4 and that develops the electrostatic latent image formed on the surface of the electrostatic latent image holding member with the electrostatic image developer to form a toner image. And a process cartridge which is detachable from the image forming apparatus. An electrostatic latent image carrier;
Charging means for charging the surface of the electrostatic latent image holding member;
Electrostatic latent image forming means for forming an electrostatic latent image on the surface of the charged electrostatic latent image holding member;
5. A development for containing the electrostatic charge image developer according to claim 4 and developing a toner image by developing the electrostatic latent image formed on the surface of the electrostatic latent image holding member with the electrostatic charge image developer. Means,
Transfer means for transferring the toner image to a recording medium;
Fixing means for fixing the toner image transferred to the recording medium;
An image forming apparatus comprising:   The image forming apparatus according to claim 7, wherein the fixing unit is a unit that fixes the toner image transferred to the recording medium with a laser beam. A charging step for charging the electrostatic latent image holding member;
An electrostatic latent image forming step of forming an electrostatic latent image on the surface of the charged electrostatic latent image holding member;
5. A development for containing the electrostatic charge image developer according to claim 4 and developing a toner image by developing the electrostatic latent image formed on the surface of the electrostatic latent image holding member with the electrostatic charge image developer. Process,
A transfer step of transferring the toner image to a recording medium;
A fixing step of fixing the toner image transferred to the recording medium;
An image forming method comprising:   The image forming method according to claim 9, wherein the fixing step is a step of fixing the toner image transferred to the recording medium with a laser beam. The croconium compound represented by the following general formula (II) or general formula (III).

(In General Formula (II), R ¹¹¹ , R ¹¹² , R ²¹¹ , and R ²¹² each independently represent a halogen group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkoxy group, and R ³¹¹ And R ³¹² each independently represents a hydrogen atom or an aliphatic group, n111 and n112 each independently represents an integer of 0 or more and 4 or less, and n211 and n212 each independently represents 0 or more and 5 or less. X represents an oxygen atom or a sulfur atom, and when n111 represents an integer of 2 or more and 4 or less, a plurality of R ¹¹¹ may be independently the same or different and bonded to each other. If .n112 never form a ring Te represents an integer of 2 to 4, a plurality of R ¹¹² are each independently may be the same or different, to form a ring bonded to each other If There .n211 represents an integer of 2 to 5, a plurality of R ²¹¹ are each independently may be the same or different, .N212 never bonded to each other to form a ring of 2 to 5 A plurality of R ^{212 s} may be the same or different and are not bonded to each other to form a ring.

(In General Formula (III), R ²²¹ and R ²²² each independently represent a halogen group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkoxy group, and R ³²¹ and R ³²² are each independently N221 and n222 each independently represents an integer of 0 or more and 5 or less, X represents an oxygen atom or a sulfur atom, and n221 is 2 or more and 5 or less. In the case of representing an integer, the plurality of R ²²¹ may be independently the same or different, and when n222 represents an integer of 2 or more and 5 or less, the plurality of R ²²² are independently the same or different. And may not be bonded to each other to form a ring.)

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