JP5470731B2 - Image forming method and image forming apparatus - Google Patents

Description

The present invention relates to an image forming method and an image forming apparatus.

  As an image forming apparatus using an electrophotographic system, a number of systems are conventionally known. In the electrophotographic system, first, a latent image is electrically formed on a photosensitive member (image holding member) using a photoconductive substance by various means, and the latent image is developed as a toner image using toner. After transferring the toner image to a recording medium such as paper with or without an intermediate transfer member, the toner image is fixed by heating, pressing, heating and pressing, or solvent vapor. A fixed image is formed after that. The toner remaining on the image carrier is cleaned by various methods, and the plurality of steps are repeated.

  In recent years, due to technological advancement, the above-mentioned electrophotographic image forming apparatus has been used not only for copying machines and printers but also for printing applications. In addition to the high speed and high reliability of the apparatus, the copied material has become a printed material. In addition to having high image quality and hue comparable to each other, it is also an important characteristic that the formed image has high storage stability.

As means for improving high-speed aptitude and image glossiness, a toner containing a crystalline resin is disclosed (for example, see Patent Documents 1 and 2). Since the crystalline resin has a melting point and melts at a temperature equal to or higher than the melting point, the low temperature fixability is improved by including this in the binder resin, and as a result, high-speed fixing suitability can be realized. Further, since the crystalline resin has a low melt viscosity, it is an effective method for improving image glossiness.
As the binder resin, polyester is preferably used from the viewpoint of low-temperature fixability and storage stability. In recent years, styrene acrylic copolymer resins such as polymerized toners have been used from the viewpoint of manufacturability, but polyester has a more suitable melt property in order to obtain a high gloss image.

Further, a toner that defines the relationship between the melting point of the crystalline resin and the release agent is disclosed (for example, see Patent Documents 3 and 4). Furthermore, a toner containing a zirconium compound (see, for example, Patent Documents 5 and 6) and a method of synthesizing a crystalline resin using a strong acid salt compound of zirconium as a polycondensation auxiliary catalyst and using the toner for a toner are disclosed (for example, And Patent Document 7).
JP-A-1-35454 JP 2006-171692 A JP 2004-163846 A JP 2005-234046 A Japanese Patent Laid-Open No. 6-11900 JP 2004-340982 A JP 2006-265416 A

As described above, image storability is an important characteristic for an image formed on a recording medium. Examples of image storability include problems in which images deteriorate or adhere to each other when the images are stored in an overlapping manner.
In particular, in printing applications, there is a case where a bookmark is stored as a mark on a printed material, and a high load is locally applied, so that image deterioration is easily promoted. In particular, when a metal heel is used, since the heel itself is very hard, the influence on the image is great. For example, when a high load is applied for a long period of time such as one month or more, the gloss of the image changes only in the heel portion. The problem arises.
For this reason, an image forming method and an image forming apparatus capable of forming an image having excellent image strength have been demanded from the viewpoint of realizing excellent image storage stability.

That is, an object of the present invention is to provide an image forming method and an image forming apparatus capable of forming an image having excellent image strength.

The above-mentioned subject is achieved by the following present invention.
That is, the invention according to claim 1
A latent image forming step for forming a latent image on an image carrier, a developing step for developing the latent image into a toner image with a developer containing toner containing at least crystalline polyester, and the obtained toner image as a recording medium An image forming method comprising: a transfer step of transferring the toner image; and a fixing step of fixing the transferred toner image to a recording medium by a fixing unit, and satisfying the following [Condition 1] to [Condition 5 ]: Is the method.
The invention according to claim 4
A latent image forming means for forming a latent image on an image carrier, a developing means for developing the latent image into a toner image with a developer containing a toner containing at least crystalline polyester, and the obtained toner image as a recording medium An image forming apparatus comprising: a transfer unit that transfers the toner image to a recording medium; and a fixing unit that fixes the transferred toner image to a recording medium, wherein the following [Condition 1] to [Condition 5 ] are satisfied: .
[Condition 1]
The crystalline polyester includes at least one selected from HOOC— (CH ₂ ) ₈ —COOH and HOOC— (CH ₂ ) ₁₀ —COOH as an acid component, and HO— (CH ₂ ) ₆ —OH and HO as an alcohol component. A polyester resin reacted with at least one selected from — (CH ₂ ) ₉ —OH, and has a melting point of 67 ° C. or higher and 75 ° C. or lower by differential scanning calorimetry.
[Condition 2]
The toner contains 3% by mass to 9% by mass of the crystalline polyester as a binder resin.
[Condition 3]
In accordance with ASTM D3418-8, the formed fixed image was heated at a temperature increase rate of 10 ° C. per minute as the first measurement in a measurement temperature range of 10 ° C. to 150 ° C. and held for 5 minutes after reaching 150 ° C. Then, in the DSC spectrum measured through a step of cooling to 10 ° C. at a temperature drop rate of −10 ° C. and holding for 5 minutes and then raising the temperature to 150 ° C. at a temperature increase rate of 10 ° C./min as the second measurement, The temperature rise spectrum of the first DSC measurement has a minimum value M1 in the range of 57 ° C. or more and 73 ° C. or less, and the absolute value of the spectrum intensity (depth) from the baseline to the minimum value in M1 is M1p. The temperature rise spectrum of the second measurement has a minimum value M2 in the range of 57 ° C. or more and 73 ° C. or less, and the absolute value of the spectrum intensity (depth) from the baseline to the minimum value in M2 is M2p. When, with the M1p and M2p satisfy a relationship represented by the following formula (1) and (2).
Formula (1) 1.5 * M1p <= M2p <= 5 * M1p
Formula (2) 60 (mW / g) ≦ M2p ≦ 150 (mW / g)

[Condition 4]
The content of the zirconium element is Ru der 0.001 wt% to 1.0 wt% or less in the toner.
[Condition 5]
The fixing means includes at least a heating member and a pressure member, and the heating member is arranged to form a lower side in a contact area with the pressure member, and the image surface on which the recording medium is fixed Ru is discharged in the downward.

The invention according to claim 2
The image forming method according to claim 1, wherein the temperature during the fixing of prior SL pressurized heat member is less than 240 ° C. 190 ° C. or higher.
The invention according to claim 5
The image forming apparatus according to claim 4 in which the temperature during the fixing of prior SL pressurized heat member is equal to or less than 240 ° C. 190 ° C. or higher.

The invention according to claim 3
When the toner contains at least a release agent, and the melting point of the crystalline polyester is Tc (° C.) and the melting point of the release agent is Tw (° C.), the following formula (3) is satisfied, and Ac the content of the crystalline polyester in the toner, the Aw of the content of the release agent, when an image according to claim 1 or claim 2, characterized in that satisfies the following formula (4) It is a forming method.
The invention according to claim 6
When the toner contains at least a release agent, and the melting point of the crystalline polyester is Tc (° C.) and the melting point of the release agent is Tw (° C.), the following formula (3) is satisfied, and Ac the content of the crystalline polyester in the toner, the Aw of the content of the release agent, when an image according to claim 4 or claim 5, characterized in that satisfies the following formula (4) Forming device.
Formula (3) Tc-10 ≦ Tw ≦ Tc + 30
Formula (4) Aw × 0.4 ≦ Ac ≦ Aw × 0.9

According to the first or fourth aspect of the present invention, it is possible to form an image having excellent image strength as compared with the case where the expressions (1) and (2) are not satisfied.

In addition, according to the first or fourth aspect of the present invention, it is possible to form an image having a higher image strength than when the present configuration is not provided.

According to the invention which concerns on Claim 2 or 5 , compared with the case where the temperature of a heating member is not considered, the image excellent in image strength can be formed.

According to the invention of claim 3 or 6 , it is possible to form an image having a higher image strength than when the expressions (3) and (4) are not satisfied.

Hereinafter, preferred embodiments of the present invention will be described in detail.
The image forming method according to the present embodiment includes a latent image forming step of forming a latent image on an image carrier, and a developing step of developing the latent image into a toner image with a developer containing toner containing at least crystalline polyester. And a transfer step of transferring the obtained toner image onto the recording medium, and a fixing step of fixing the transferred toner image onto the recording medium by the fixing means, and the following conditions [1] to [ 5 ] ] Is satisfied.
The image forming apparatus according to the present embodiment includes a latent image forming unit that forms a latent image on an image holding member, and a developing unit that develops the latent image into a toner image with a developer containing toner containing at least crystalline polyester. And a transfer means for transferring the obtained toner image onto the recording medium, and a fixing means for fixing the transferred toner image to the recording medium, and satisfying the following conditions [1] to [ 5 ] It is characterized by that.

[Condition 1]
The crystalline polyester includes at least one selected from HOOC— (CH ₂ ) ₈ —COOH and HOOC— (CH ₂ ) ₁₀ —COOH as an acid component, and HO— (CH ₂ ) ₆ —OH and HO as an alcohol component. A polyester resin reacted with at least one selected from — (CH ₂ ) ₉ —OH, and has a melting point of 67 ° C. or higher and 75 ° C. or lower by differential scanning calorimetry.

[Condition 2]
The toner contains 3% by mass to 9% by mass of the crystalline polyester as a binder resin.

[Condition 3]
In accordance with ASTM D3418-8, the formed fixed image was heated at a temperature increase rate of 10 ° C. per minute as the first measurement in a measurement temperature range of 10 ° C. to 150 ° C. and held for 5 minutes after reaching 150 ° C. Then, in the DSC spectrum measured through a step of cooling to 10 ° C. at a temperature drop rate of −10 ° C. and holding for 5 minutes and then raising the temperature to 150 ° C. at a temperature increase rate of 10 ° C./min as the second measurement, The temperature rising spectrum of the first DSC measurement has a minimum value M1 in the range of 57 ° C. or more and 73 ° C. or less, and the absolute value of the spectrum intensity (depth) from the baseline to the minimum value in M1 is M1p,
Further, when the temperature rise spectrum of the second DSC measurement has a minimum value M2 in the range of 57 ° C. or more and 73 ° C. or less, and the absolute value of the spectrum intensity (depth) from the baseline to the minimum value in M2 is M2p. ,
Said M1p and M2p satisfy | fill the relationship of following formula (1) and Formula (2).
Formula (1) 1.5 * M1p <= M2p <= 5 * M1p
Formula (2) 60 (mW / g) ≦ M2p ≦ 150 (mW / g)
[Condition 4]
The content of zirconium element in the toner is 0.001% by mass or more and 1.0% by mass or less.
[Condition 5]
The fixing means includes at least a heating member and a pressure member, and the heating member is arranged to form a lower side in a contact area with the pressure member, and the image surface on which the recording medium is fixed Is discharged downward.

The crystalline polyester (crystalline resin) contained in the toner melts sharply with respect to temperature, but has a hysteresis between the melting point and the freezing point, so it takes time to solidify after melting once. It has been. Therefore, when the crystalline resin is not sufficiently solidified after fixing, the image strength is insufficient. There has been a problem that the image glossiness changes due to the slow deformation.
Since the image forming method and the image forming apparatus according to the present embodiment satisfy the above formulas (1) and (2), the crystallization of the crystalline polyester contained in the toner is favorably promoted. Is formed.

Here, the calculation of M1, M2, M1p and M2p in the above formulas (1) and (2) is performed by the following method.
First, the image forming apparatus according to the present embodiment is used, and an image gloss of 60 or more (gross meter GM-26D (manufactured by Murakami Color Research Laboratory Co., Ltd.)) is used to set the incident light angle to the sample to 75 degrees. The fixed image of the image gloss measured in step 1 is formed on C2 paper (manufactured by Fuji Xerox Co., Ltd.), and the fixed image is scraped from the paper.
Next, differential scanning calorimetry is performed using a differential scanning calorimeter (DSC) in accordance with ASTM D3418-8. Differential scanning calorimetry uses a differential scanning calorimeter equipped with an automatic tangential processing system (manufactured by Mac Science: DSC3110, thermal analysis system 001) with a liquid nitrogen cooling device, and the sample amount is 8 mg or more and 10 mg or less, The measurement temperature range is 10 ° C to 150 ° C. First, as the first measurement, the temperature was raised at a rate of temperature increase of 10 ° C./minute, held for 5 minutes after reaching 150 ° C., and then cooled to 10 ° C. at a temperature decrease rate of −10 ° C./minute for 5 minutes. Hold. Thereafter, as the second measurement, the temperature is raised to 150 ° C. under the same conditions as in the first measurement. At this time, the spectra obtained by the first and second temperature rises are defined as the first temperature rise spectrum and the second temperature rise spectrum, respectively.
The entire spectrum of the first temperature rise spectrum and the second temperature rise spectrum is shifted so that the endothermic amount at 20 ° C. becomes 0, and the shift of the baseline is corrected. Further, the measured spectrum is divided by the sample amount used for the measurement, the spectrum intensity per unit mass is calculated, and the deviation of the spectrum intensity due to the sample amount is corrected.
Using the spectrum corrected in this way, in the first temperature rise spectrum, the minimum value in the range of 57 ° C. or more and 73 ° C. or less (in the case of having a plurality of minimum values, the absolute value of the spectrum intensity is the maximum). Is a minimum value), and the spectrum intensity at the minimum value M1 is M1p. Similarly, in the second temperature rise spectrum, the minimum value of 57 ° C. or more and 73 ° C. or less (in the case of having a plurality of minimum values, the minimum value of the spectrum intensity is the maximum value) is set to “minimum value”. M2 ”, and the spectrum intensity at the minimum value M2 is defined as M2p.
The numerical values described in this specification are calculated by the above method.

In measuring the content of the crystalline polyester in the toner, the crystalline polyester can be extracted from the components contained in the toner by the following method.
First, the toner is dissolved in methyl ethyl ketone (MEK) at room temperature (20 ° C. or more and 25 ° C. or less). This is because, for example, when a crystalline polyester and an amorphous resin are contained in the toner, almost only the amorphous resin is dissolved in MEK at room temperature. Therefore, the amorphous resin is contained in the MEK-soluble component. Therefore, after the dissolution, the amorphous resin is obtained from the supernatant separated by centrifugation, while the solid content after centrifugation is obtained. By heating at 65 ° C. for 60 minutes and dissolving in THF, and filtering this with a glass filter at 60 ° C., a crystalline polyester can be obtained from the filtered portion. In addition, since crystalline polyester will precipitate if temperature falls during this operation during filtration, it is operated quickly and in a state of keeping warm so that the temperature does not fall. The content is determined by measuring the amount of the crystalline polyester thus obtained.
The numerical values described in this specification are calculated by the above method.

Next, examples of the achievement means for satisfying the above formulas (1) and (2) include the following methods.
[1] Inclusion of zirconium element in toner and fixing means
In this embodiment, the content of zirconium element in the toner is controlled to 0.001% by mass or more and 1.0% by mass or less, and the fixing unit includes at least a heating member and a pressure member, and the heating unit member, with the arrangement that forms the lower side in the contact region with the pressure member, shall be the manner in which the recording medium is discharged in the downward fixed image plane.

  Here, “down” and “downward” in the above-mentioned direction means a downward direction with respect to the horizontal plane when the image forming apparatus is installed on the horizontal plane. In addition, “to form the lower side in the contact region” means that the relative relationship is the lower side in at least 50% or more of all the contact regions (when the tangent is drawn, the heating member side between the horizontal plane and the tangent is The angle (α) is 0 ° ≦ α ≦ | 90 ° |).

  In the toner, the zirconium element is presumed to exhibit an action as a crystal nucleating agent in crystallization of the crystalline polyester, and the content of the zirconium element is 0.001% by mass or more and 1.0% by mass or less. By being, the effect is expressed well.

The content of the zirconium element is more Ri der 0.001 wt% to 1.0 wt% or less, particularly preferably 0.005 wt% to 0.5 wt%.

The zirconium element content can be determined from the composition ratio calculated from the fluorescent X-ray analysis of the toner. The X-ray fluorescence analysis is obtained by using XRF-1500 (manufactured by Shimadzu Corp.) as a measuring device and measuring all elements at a tube voltage of 40 kV, a tube current of 90 mA, and a measurement time of 30 minutes. As the sample, a sample amount of 6 g of toner is used which is pressure-molded with a pressure molding machine with a load of 10 t and a pressure time of 1 minute. The composition ratio is calculated from the measured Net intensity in consideration of the element mass.
The numerical values described in this specification are calculated by the above method.

  Further, since the heating member forms the lower side in the contact area with the pressure member, the heat in the fixing device can be transferred well to the image and the recording medium, and the crystallization of the crystalline polyester is promoted well. . Furthermore, by discharging the recording medium on which the image surface is fixed downward, the heat retained in the image at the time of fixing is well maintained without diffusing into the air, and the crystalline polyester is crystallized. Promote well.

[2] Temperature of heating member It is preferable that the temperature at the time of fixing the heating member in the fixing unit is 190 ° C or higher and 240 ° C or lower.
The amount of heat applied to the image can be in a good range, the temperature in the fixing device as a fixing means can be controlled in a good range, and the crystallization of the crystalline polyester is promoted well. In addition, it is preferable that the temperature of the said heating member shall be 195 degreeC or more and 230 degrees C or less further.

[3] Relationship between melting point and content of crystalline polyester and release agent The toner contains at least a release agent, the melting point of the crystalline polyester is Tc (° C.), and the melting point of the release agent is Tw (° C. ), The following formula (3) is satisfied, and when the crystalline polyester content in the toner is Ac and the release agent content is Aw, the following formula (4) is satisfied. preferable.
Formula (3) Tc-10 ≦ Tw ≦ Tc + 30
Formula (4) Aw × 0.5 ≦ Ac ≦ Aw × 1.2

  When the melting point Tc (° C.) of the crystalline polyester and the melting point Tw (° C.) of the release agent are in the relationship of the above formula (3), the heat (crystallization heat) released when the release agent crystallizes, It is effectively used for crystallization of crystalline polyester and promotes crystallization.

  Further, since the content Ac of the crystalline polyester in the toner and the content Aw of the release agent are in the relationship of the above formula (4), the use of crystallization heat when the release agent is crystallized. Is carried out efficiently and promotes crystallization of the crystalline polyester.

  In addition, it is more preferable that the above formulas (3) and (4) further satisfy the following formulas (3 ′) and (4 ′).

Formula (3 ′) Tc−0 ≦ Tw ≦ Tc + 20
Formula (4 ′) Aw × 0.5 ≦ Ac ≦ Aw × 0.8

  Here, the above-mentioned melting point is measured by differential scanning calorimetry based on ASTM D3418-8. Specifically, a crystalline polyester or a release agent to be measured is set in a differential scanning calorimeter (manufactured by Mac Science: DSC3110, thermal analysis system 001) equipped with an automatic tangential processing system, and liquid nitrogen is set as a cooling medium. To do. Heat from 20 ° C. to 150 ° C. at a rate of temperature increase of 10 ° C./min (first temperature increase process) to obtain the relationship between temperature (° C.) and calorie (mW), and then decrease the temperature by −10 ° C./min The sample is cooled to 0 ° C. at a rate, and again heated to 150 ° C. at a rate of temperature increase of 10 ° C./min (second temperature increase process) to collect data. In addition, it hold | maintained for 5 minutes each at 0 degreeC and 150 degreeC. The endothermic peak temperature in the second temperature raising process can be regarded as the melting point. In addition, although several melting peaks may be shown, the maximum peak is regarded as the melting point.

The crystalline polyester can be extracted from the components contained in the toner by the method described above. Further, the mold release agent can be taken out by the following method.
In the above operation for taking out the crystalline polyester, the filtration residue is a component obtained by removing the amorphous resin and the crystalline polyester from the toner. In addition to the solvent-free mold release agent, the filtration residue contains a part of the pigment and the external additive. When the filtration residue is dried under reduced pressure to remove the solvent, and heated to 120 ° C., the infusible component is dispersed in the molten release agent. Since the infusible component settles by leaving it to stand for 96 hours in a heated state, the release agent is taken out by collecting the supernatant while taking care not to include the sediment component.
However, even with the above method, a part of the mold release agent remains together with the infusible component, and thus cannot be completely removed. Therefore, the amount of the amorphous resin and the crystalline resin contained in the toner is calculated from the amount of the amorphous resin and the crystalline polyester taken out by the above-mentioned method, and the taken-off release agent is obtained with respect to the amount ratio. Are added to the resin composition, 3% by mass, 6% by mass, 9% by mass, 12% by mass and 15% by mass, respectively, and the DSC spectrum of this resin composition is measured. A calibration curve of the spectral intensity with respect to the added amount of the release agent is prepared from the spectral intensity. From the spectrum intensity of the release agent obtained from the DSC spectrum of the actual toner, the amount of the release agent is calculated using the calibration curve.
The numerical values described in this specification are calculated by the above method.

  The melting point of the crystalline polyester is desirably in the range of 55 ° C. or higher and 120 ° C. or lower, and more preferably in the range of 65 ° C. or higher and 80 ° C. or lower.

Next, each configuration of the image forming apparatus according to the present embodiment will be described more specifically.
The image forming apparatus of the present embodiment includes each means (latent image forming means, developing means, transferring means, fixing means) for performing a latent image forming process, a developing process, a transferring process, a fixing process, etc. Each of these means may be provided separately for each type of toner, or one or two common means may be provided. Whether each means is commonly used or provided separately for each type of toner can be selected in consideration of downsizing of the apparatus, securing of image forming speed, image quality, and the like.
For example, when performing high-speed image formation, a so-called tandem-type image forming apparatus including an image forming unit corresponding to each type of toner (developer) can be provided, and a small-sized apparatus is desired. Can be an image forming apparatus employing a so-called rotary developing system in which a developing device for developing each type of toner (developer) is provided in one developing device.

  The image carrier used in the image forming apparatus of the present embodiment is not particularly limited and a conventionally known one can be used without any problem, and may be a single layer structure, or a multilayer structure and a function separation type. It may be. Further, the material may be an inorganic photoreceptor such as selenium or amorphous silicon, or an organic photoreceptor.

As the charging means, for example, conductive or semiconductive (in this specification, “conductive” means a volume resistivity of less than 10 ⁷ Ω · cm, and “semiconductive” means a volume resistivity of 10 ⁷ Ω · cm to 10 ¹³ Omega · cm means below) of the roller, brush, film, contact charging device using a rubber blade or the like, such as a non-contact type charging device such as corotron charger or a scorotron charger utilizing corona discharge, Means known per se can be used.

As the latent image forming means, a conventionally known exposure means such as a combination of a semiconductor laser and a scanning device, a laser comprising an optical system, or an LED head can be used. In order to realize a preferable mode of producing an exposure image with high resolution, it is preferable to use a laser or an LED head.
As the image signal forming apparatus, any conventionally known means can be used as long as a signal capable of forming a toner image at a desired position on the surface of the recording medium can be formed.

  As a toner image forming means (developing device), as long as it has a function of forming a high-resolution toner image on the electrostatic latent image on the surface of the photosensitive member, a conventionally known development is possible regardless of one-component system or two-component system. The device can be used. From the viewpoint that tone reproduction with good graininess can be performed, a two-component developing device is preferable.

  As the transfer means, for example, a conductive or semiconductive roller, brush, film, rubber blade or the like to which a voltage is applied is used to create an electric field in a region sandwiched between the photosensitive member and the recording medium or intermediate transfer member. , Means for transferring a toner image containing charged toner particles, corona charge using corona discharge, scorotron charger, etc., corona charging the back surface of the recording medium or intermediate transfer member, and containing charged toner particles Conventionally known means such as a means for transferring a toner image can be used.

As the intermediate transfer member, an insulating material (in this specification, “insulating” means a material having a volume resistivity exceeding 10 ¹³ Ω · cm) or a semiconductive belt material, an insulating material or a semiconductive material. A drum shape with a surface can be used. A semiconductive belt material is preferable from the viewpoint of stably maintaining transferability during continuous image formation and reducing the size of the apparatus. As this belt material, a belt material containing a resin material in which a conductive filler such as carbon fiber is dispersed is known. As this resin, for example, a polyimide resin is preferable.

  As the secondary transfer device used in the secondary transfer, for example, a conductive or semiconductive roller, brush, film, rubber blade, or the like to which a voltage is applied is used to sandwich the intermediate transfer body and the recording medium. The surface of the intermediate transfer member is corona-charged with a means for creating an electric field in the area to transfer the toner image having the charged toner particles, a corotron charger using a corona discharge, a scorotron charger, etc. Known means such as a means for transferring the toner image can be used.

In the present embodiment, as described above, the fixing unit includes at least a heating member and a pressure member, and the heating member is disposed so as to form a lower side in a contact area with the pressure member. Ru aspects der discharged by the image plane medium is fixed downward. Further, the temperature at the time of fixing the heating member in the fixing unit is preferably 190 ° C. or higher and 240 ° C. or lower.

  The heating member and the pressure member used for the fixing are not particularly limited, but an embodiment in which both are roll-shaped members are preferable, and one member is an endless belt-shaped member and the other member is a roll-shaped member. The aspect which is a member can also be used. Further, the heating source in the heating member is preferably built in the roll-shaped member in the case of a roll-shaped member, and arranged on the inner peripheral side in the case of an endless belt-shaped member. Further, when the heating member is an endless belt-like member, a fixing method using an electromagnetic induction heating method can also be adopted.

  FIG. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present exemplary embodiment. The image forming apparatus shown in FIG. 1 employs a rotary developing system for forming a full-color image. The color toner image forming apparatus (reference numerals 2 to 16) for forming a color toner image and the color toner are large. It is divided into a fixing device having a heating member 20 and a pressure member 30 for fixing an image on the surface of the recording medium, and both are connected by a conveying device 19 and a recording medium reversing means 40.

In the color toner image forming apparatus, first, the original 1 to be read is irradiated with light by the illumination 2, and the reflected light is read by the color scanner 3. The read signal is sent to an image processing device (image signal forming device) 4 where it is separated into colors of yellow Y, magenta M, cyan C and black K, and an image signal for controlling exposure is exposed to an exposure device ( (Latent image forming means).
In the optical system 6, the laser diode 5 emits light for each color component, and the surface of the organic photoreceptor (image holding member) 8 is irradiated with image-like light X for each color component. On the other hand, the organic photoreceptor 8 is rotated in the direction of arrow A, and the surface is first charged by the charger 7 and then exposed by the optical system 6 described above, and the developing devices (developing means) 9-12. It is used for development.

  For example, taking the yellow Y color as an example, the surface of the organic photoreceptor 8 is irradiated by the optical system 6 with the light color-separated into the yellow Y color component by the image processing device 4. The surface of the organic photoreceptor 8 is charged in advance by the charger 7, and the portion irradiated with the light is charged to the opposite polarity to form a latent image. Then, the latent image on the surface of the organic photoreceptor 8 is developed by the yellow developing device 9 with yellow Y color toner. Further, the organic photoreceptor 8 rotates in the direction of arrow A, and is transferred onto the surface of the intermediate transfer belt (intermediate transfer body) 13 by electrostatic attraction of the transfer corotron 14. After the transfer, the surface of the organic photoreceptor 8 is charged by the charger 7 by further rotation in the direction of the arrow A to prepare for image formation of the next color.

  Subsequent to the yellow Y color, the operations described above are performed for each of the magenta M, cyan C, and black K colors, and the latent image is sequentially developed by the magenta developing unit 10, the cyan developing unit 11, and the black developing unit 12, Laminated on the transfer belt 13. The intermediate transfer belt 13 rotates in the direction of arrow B as the organic photoconductor 8 rotates at the time of transferring each color. When the transfer is completed, the intermediate transfer belt 13 rotates in the opposite direction and returns to the original position, and the next color is transferred. When the image is printed, it is laminated on the color toner image transferred before that. When all four colors are stacked, they are rotated as they are in the direction of the arrow B, and sent to a transfer area sandwiched between transfer rolls (secondary transfer devices) 15 and 16. In the transfer area, a sheet 17 as a recording medium on which an image is to be formed is inserted in the direction of arrow C with the intermediate transfer belt 13 in contact with the surface. The laminated color toner images are transferred onto the surface of the paper (recording medium) 17 by the electrostatic action of the transfer rolls (transfer means) 15 and 16.

  The sheet 17 to which the color toner image has been transferred is conveyed by the conveying device 19 along the direction of arrow C to the recording medium reversing means 40 having a pair of rolls, and the sheet 17 is sandwiched between the pair of rolls. The paper 17 once sandwiched is conveyed in the direction of arrow D when the rotation of the pair of rolls in the recording medium reversing means 40 is reversed, and is conveyed to the fixing device in a state where the surface on which the toner image is formed is reversed. . As the pair of rolls in the recording medium reversing means 40, known rolls can be used, and FIG. 1 shows the recording medium reversing means having a pair of rolls, but other known means can also be used. .

  Next, the fixing device will be described with reference to FIG. 2 which is an enlarged view of the fixing device (fixing means) shown in FIG. The fixing device fixes the toner image on the paper 17 using heat, and includes a hollow cylindrical heating member 20 and a pressure member 30 disposed to face the heating member 20.

The heating member 20 includes a cored bar 24 and a surface resin tube layer 26 for preventing the offset phenomenon of the toner image on the surface of the cored bar 24, and further includes a heating source 22 inside.
As a material for forming the cored bar 24, generally, iron, stainless steel, aluminum having excellent thermal conductivity, or the like having excellent rigidity is used, but other metals or the like may be used.
Examples of the resin of the surface resin tube layer 26 include polytetrafluoroethylene (PTFE), perfluoroalkyl vinyl ether copolymer (PFA), and tetrafluoroethylene hexafluoropropylene copolymer. Of these, PFA is preferred. In addition, in order to improve adhesiveness with the core metal 24, a primer process etc. can be given to the tube inner surface. The thickness of the surface resin tube layer 26 is preferably in the range of 5 μm to 50 μm, more preferably 10 μm to 40 μm.
Examples of the heating source 22 include a Colts lamp and a ceramic heater, and the heating source 22 connected to an electric circuit that controls the heating state based on the outer peripheral surface temperature of the heating member 20 detected by a temperature sensor is used. Examples of the temperature sensor include a thermal resistance element such as a thermocouple and a thermistor. The surface temperature of the heating member 20 (the temperature at the time of fixing) is preferably controlled to 190 ° C. or higher and 240 ° C. or lower as described above.

  The pressure member 30 is formed of, for example, a metal core roll covered with silicone rubber or the like. The sheet 17 is arranged so that it can pass through the contact area with the heating member 20.

  As shown in FIG. 2, in the heating member 20 and the pressure member 30 according to the present embodiment, the angle (α) on the heating member 20 side formed by the tangent drawn in the contact area and the horizontal plane is −90 ° ≦ α ≦ + 90 °. In other words, the heating member 20 is arranged to form the lower side in the contact area with the pressure member 30. Further, as shown in FIG. 1, the sheet 17 is inserted into the contact area of the fixing device with the surface on which the toner image is formed reversed by the recording medium reversing means 40, and the fixing device with the fixed image surface facing downward. It is a mode to be discharged from.

  The sheet 17 on which the laminated color toner images are transferred is inserted into a contact area formed by the heating member 20 and the pressure member 30 in the fixing device as described above, and the toner image is formed by being heated and pressed. Fixing is performed, and an image is formed on the sheet 17.

Next, the toner and developer used in this embodiment will be described.
(toner)
As described above, the toner according to the exemplary embodiment is required to use a toner that includes at least crystalline polyester and satisfies the following [Condition 1] , [Condition 2], and [Condition 4] .
[Condition 1]
The crystalline polyester includes at least one selected from HOOC— (CH ₂ ) ₈ —COOH and HOOC— (CH ₂ ) ₁₀ —COOH as an acid component, and HO— (CH ₂ ) ₆ —OH and HO as an alcohol component. A polyester resin reacted with at least one selected from — (CH ₂ ) ₉ —OH, and has a melting point of 67 ° C. or higher and 75 ° C. or lower by differential scanning calorimetry.
[Condition 2]
The toner contains 3% by mass to 9% by mass of the crystalline polyester as a binder resin.

[Condition 4]
The content of zirconium element is 1.0 mass% or less than 0.001 wt% in the toner.
Further, when the melting point of the crystalline polyester is Tc (° C.) and the melting point of the release agent is Tw (° C.), the following formula (3) is satisfied, and the content of the crystalline polyester in the toner is Ac, When the content of the release agent is Aw, it is preferable to satisfy the following formula (4).
Formula (3) Tc-10 ≦ Tw ≦ Tc + 30
Formula (4) Aw × 0.5 ≦ Ac ≦ Aw × 1.2

-Binder resin-
In the present embodiment, the crystalline resin refers to a resin having a clear endothermic peak rather than a stepwise endothermic amount change in differential scanning calorimetry (DSC). Further, the endothermic peak may show a peak having a width of 40 ° C. or more and 50 ° C. or less when the toner is used. Regarding the crystalline polyester, in the case of a polymer obtained by copolymerizing other components with respect to the crystalline polyester main chain, if the other components are 5% by mass or less, this copolymer is also called crystalline polyester.
Hereinafter, a crystalline polyester will be described as an example of the crystalline resin. As described above, in this embodiment, it is necessary to use a crystalline polyester that satisfies the above [Condition 1].

  The crystalline polyester is a specific polyester synthesized from an acid (dicarboxylic acid) component and an alcohol (diol) component. In the following description, the constituent site that was an acid component before the synthesis of the polyester is “acid-derived constituent component”, the constituent site that was the alcohol component before the synthesis of the polyester is “alcohol-derived constituent component”, Express each one. In the case of crystalline polyester, the resin can be synthesized by transesterification, but the acid ester used at this time is also referred to as “acid-derived constituent component”.

(1) Acid-derived constituent component As shown in [Condition 1], the acid component to be the acid-derived constituent component is selected from HOOC— (CH ₂ ) ₈ —COOH and HOOC— (CH ₂ ) ₁₀ —COOH. At least one is used. In addition, it is preferable to use these components at least 50 mol% or more among all the acid components used for reaction of the said crystalline polyester, and it is more preferable to use 80 mol% or more further.

  Examples of the acid component used in combination include various dicarboxylic acids, but as the main acid-derived constituent components in the polyester, aliphatic dicarboxylic acids and aromatic dicarboxylic acids are desirable, and in particular, aliphatic dicarboxylic acids are linear. Carboxylic acid is preferred.

  Examples of the aliphatic dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelic acid, 1,9-nonanedicarboxylic acid, 1,11-undecanedicarboxylic acid, 1, 12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, 3,3′-thiodipropionic acid, etc. Or the lower alkyl ester and acid anhydride are mentioned, However, It is not this limitation.

  In this embodiment, aromatic dicarboxylic acid may be copolymerized. Examples thereof include terephthalic acid, isophthalic acid, orthophthalic acid, t-butylisophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-biphenyldicarboxylic acid, among which terephthalic acid, isophthalic acid, t-butylisophthalic acid These alkyl esters are preferable in terms of availability, easy formation of easily emulsifiable polymers, and the like. The copolymerization amount is preferably 10 mol% or less.

  In the present specification, “constituent mol%” means that the acid-derived constituent component in the whole acid-derived constituent component in the polyester or the alcohol constituent component in the whole alcohol-derived constituent component described later is 1 unit ( Mol).

  Examples of the acid-derived constituent component include the above-mentioned aliphatic dicarboxylic acid (main component) -derived constituent component and aromatic dicarboxylic acid (copolymerization component) -derived constituent component, dicarboxylic acid-derived constituent component having a double bond, and sulfonic acid. A constituent component such as a constituent component derived from a dicarboxylic acid having a group may be contained.

  In addition to the components derived from dicarboxylic acids having a double bond, the components derived from lower alkyl esters or acid anhydrides of dicarboxylic acids having a double bond are included in the components derived from dicarboxylic acids having a double bond. included. Further, the dicarboxylic acid-derived constituent component having a sulfonic acid group is derived from a lower alkyl ester or acid anhydride of a dicarboxylic acid having a sulfonic acid group, in addition to a constituent component derived from a dicarboxylic acid having a sulfonic acid group. Components are also included.

  A dicarboxylic acid having a double bond can be suitably used in order to prevent hot offset at the time of fixing since the entire resin can be cross-linked using the double bond. Examples of the dicarboxylic acid include, but are not limited to, fumaric acid, maleic acid, 3-hexenedioic acid, and 3-octenedioic acid. Moreover, these lower alkyl esters, acid anhydrides, etc. are also mentioned. Among these, fumaric acid, maleic acid and the like are preferable in terms of cost.

  The content of these dicarboxylic acid-derived components having double bonds in the total acid-derived components is preferably 10 component mol% or less.

  A dicarboxylic acid having a sulfonic acid group is effective in that it can favorably disperse a coloring material such as a pigment. Further, when the particles are prepared by emulsifying or suspending the entire resin in water, if the sulfonic acid group is present, the resin can be emulsified or suspended without using a surfactant as described later. Examples of the dicarboxylic acid having a sulfonic acid group include, but are not limited to, 2-sulfoterephthalic acid sodium salt, 5-sulfoisophthalic acid sodium salt, and sulfosuccinic acid sodium salt. Moreover, these lower alkyl esters, acid anhydrides, etc. are also mentioned. Among these, 5-sulfoisophthalic acid sodium salt is preferable from the viewpoint of cost.

  When the dicarboxylic acid-derived component having the sulfonic acid group is contained in the polymer, the content of the dicarboxylic acid-derived component having the sulfonic acid group in the total acid-derived component is 5 component mol% or less. It is desirable. Moreover, it is more desirable to use the above content in the range of 3 constituent mol% or less. Although not necessarily used as a copolymerization component, it may be used to assist emulsification of the resin.

(2) Alcohol-derived constituent component As shown in [Condition 1], the alcohol component to be the alcohol-derived constituent component is selected from HO— (CH ₂ ) ₆ —OH and HO— (CH ₂ ) ₉ —OH. At least one is used. In addition, it is preferable to use these components at least 50 mol% or more among all the alcohol components used for reaction in the said crystalline polyester, and it is more preferable to use 80 mol% or more further.

  The alcohol component used in combination is preferably an aliphatic diol, more preferably a linear aliphatic diol having a chain carbon number of 6 or more and 20 or less. The chain carbon number is more preferably 14 or less.

  Further, when a polyester is obtained by condensation polymerization with an aromatic dicarboxylic acid, the chain carbon number is preferably an odd number.

  Specific examples of the aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,7-heptanediol, and 1,8-octane. Diol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, 1,20-eico Examples include, but are not limited to, sundiol. Among these, ethylene glycol, 1,4-butanediol, and 1,10-decanediol are preferable in view of availability.

  The other components contained as necessary are components such as a diol-derived component having a double bond and a diol-derived component having a sulfonic acid group. Examples of the diol having a double bond include 2-butene-1,4-diol, 3-butene-1,6-diol, 4-butene-1,8-diol and the like.

  The content of these diol-derived components having double bonds in the total acid-derived component is preferably 20 component mol% or less, more preferably 2 component mol% or more and 10 component mol% or less.

  Examples of the diol having a sulfonic acid group include 1,4-dihydroxy-2-sulfonic acid benzene sodium salt, 1,3-dihydroxymethyl-5-sulfonic acid benzene sodium salt, and 2-sulfo-1,4-butanediol sodium. Examples include salts.

  The content of these diol-derived constituent components having a sulfonic acid group in the total acid-derived constituent components is preferably 5 constituent mol% or less, and only the minimum required amount is required. If it is not necessary, it is not necessary to use it as a copolymerization component, but a minimum amount may be used to assist emulsification of the resin. About the usage-amount, it is necessary to adjust the amount to the minimum especially with the dicarboxylic acid component which has the above-mentioned sulfonic acid group.

  When adding an alcohol-derived component other than these aliphatic diol-derived components (such as a diol-derived component having a double bond and a diol-derived component having a sulfonic acid group), the content in these alcohol-derived components Is preferably in the range of 0 constituent mol% to 10 constituent mol%.

  The crystalline polyester can be freely combined from the monomer components described above, for example, polycondensation (chemical doujin), polymer empiricals (polycondensation and polyaddition: Kyoritsu Publishing) and polyester handbook (Nikkan Kogyo Shimbun) Etc.) can be synthesized by using a conventionally known method as described in ed.), And a transesterification method, a direct polycondensation method, or the like can be used alone or in combination.

  The molecular weight of the crystalline polyester is preferably in the range of 1,000 to 200,000 in terms of weight average molecular weight Mw and in the range of 500 to 100,000 in terms of number average molecular weight Mn. The Mw of the crystalline polyester is more preferably from 5,000 to 100,000.

  The melting point of the crystalline polyester needs to be in the range of 67 ° C. or higher and 75 ° C. or lower. In addition, it is preferable to control so that said Formula (3) may be satisfy | filled in relation with melting | fusing point of the below-mentioned mold release agent.

  The content of the crystalline polyester in the toner needs to be in the range of 3% by mass to 9% by mass, and more preferably in the range of 4% by mass to 7.5% by mass. In addition, it is preferable to control so that said Formula (4) may be satisfy | filled in relation with content of the mold release agent mentioned later.

In the toner of this embodiment, it is desirable that the binder resin contains an amorphous resin. Although there is no restriction | limiting in particular as an amorphous resin, It is preferable that a glass transition temperature exists in the range of 40 to 75 degreeC. In the present embodiment, the amorphous resin refers to a resin having a stepwise endothermic change in differential scanning calorimetry (DSC).
As the amorphous resin, a conventional amorphous resin for toner can be applied as it is. Examples thereof include, but are not limited to, polystyrene, styrene butadiene polymer, styrene acrylic polymer, and polyester. These amorphous resins may be modified with urethane, urea, epoxy or the like. However, in this embodiment, since the above-mentioned crystalline polyester is used, it is desirable that the amorphous resin is also an amorphous polyester in consideration of compatibility with this during heating.

As a monomer used for amorphous polyester, for example, a conventionally known divalent or trivalent or higher carboxylic acid, which is a monomer component described in “Polymer Data Handbook: Basic Edition” (Science of Polymer Society: Bafukan) Examples thereof include acids and divalent or trihydric or higher alcohols.
Specific examples of these monomer components include divalent carboxylic acids such as succinic acid, glutaric acid, adipic acid, peric acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, and naphthalene-2. , 6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, cyclohexanedicarboxylic acid, malonic acid, mesaconic acid, dodecenyl succinic acid, and the like, and their anhydrides and their lower alkyl esters, maleic acid, fumaric acid Examples thereof include aliphatic unsaturated dicarboxylic acids such as acid, itaconic acid and citraconic acid. Examples of the trivalent or higher carboxylic acid include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, and the like, and anhydrides thereof. And lower alkyl esters. These may be used individually by 1 type and may use 2 or more types together.

Examples of the divalent alcohol include bisphenol A, hydrogenated bisphenol A, ethylene oxide and / or propylene oxide adduct of bisphenol A, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, ethylene glycol, diethylene glycol, propylene Examples include glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, and neopentyl glycol.
Examples of the trivalent or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like. These may be used individually by 1 type and may use 2 or more types together. If necessary, monovalent acids such as acetic acid and benzoic acid, and monovalent alcohols such as cyclohexanol and benzyl alcohol can be used for the purpose of adjusting the acid value and the hydroxyl value.

The amorphous polyester can also be obtained by a method for the crystalline polyester, for example, by using a polycondensation, a transesterification method, a direct polycondensation method or the like alone or in combination.
The weight average molecular weight of the amorphous polyester is preferably in the range of 10,000 to 40000, and more preferably in the range of 20000 to 30000.

  In this embodiment, the mass ratio (A / B) of the content A of the crystalline polyester and the content B of the amorphous polyester in the binder resin is in the range of 10/90 to 30/70. It is desirable to be. When the ratio between the two resins is within the above range, the effect of improving the toner image strength when the specific crystalline polyester is used can be effectively exhibited while maintaining the low-temperature fixability. The mass ratio is more preferably in the range of 15/85 to 20/80.

-Zirconium element-
That controls the content of the zirconium element below 1.0 wt% 0.001 wt% in the toner. Examples of the zirconium compound added to the toner include zirconia powder and the like, and zirconia powder having a particle size of 300 nm or less is particularly preferable.

-Release agent-
The release agent is generally used for the purpose of improving release properties.
Specific examples of the release agent include low molecular weight polyolefins such as polyethylene, polypropylene and polybutene; silicones having a softening temperature by heating; fatty acid amides such as oleic acid amide, erucic acid amide, ricinoleic acid amide, and stearic acid amide Plant waxes such as carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil; animal waxes such as beeswax; montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, etc. Mineral / petroleum waxes; ester waxes such as fatty acid esters, montanic acid esters, and carboxylic acid esters. These release agents may be used alone or in combination of two or more.

The addition amount of these release agents is preferably 0.5% by mass or more and 50% by mass or less, more preferably 1% by mass or more and 30% by mass or less, and still more preferably based on the total amount of toner particles. It is 5 mass% or more and 15 mass% or less.
In addition, it is preferable to select the kind of mold release agent so that said Formula (3) may be satisfy | filled in relation to melting | fusing point of the above-mentioned crystalline polyester. Moreover, it is preferable to control addition amount so that the said Formula (4) may be satisfy | filled in relation to content of crystalline polyester.

-Other ingredients-
In addition to the above, other components such as a colorant are used for the toner in this embodiment.
There is no restriction | limiting in particular as a coloring agent, A well-known coloring agent is mentioned, It can select according to the objective. One colorant may be used alone, or two or more colorants of the same system may be mixed and used. Further, two or more kinds of different colorants may be mixed and used. Further, these colorants may be used after surface treatment.

As the colorant, pigments and dyes of various colors are used, and specific examples include the following.
Examples of the black pigment include carbon black, copper oxide, manganese dioxide, aniline black, activated carbon, nonmagnetic ferrite, and magnetite. Examples of yellow pigments include yellow lead, zinc yellow, yellow iron oxide, cadmium yellow, chrome yellow, Hansa yellow, Hansa yellow 10G, benzidine yellow G, benzidine yellow GR, selenium yellow, quinoline yellow, permanent yellow NCG, and the like. it can.

  Examples of the orange pigment include red mouth yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan orange, benzidine orange G, indanthrene brilliant orange RK, indanthrene brilliant orange GK and the like. Red pigments include Bengala, cadmium red, red lead, mercury sulfide, watching red, permanent red 4R, risor red, brilliant carmine 3B, brilliant carmine 6B, pyrazolone red, rhodamine lake B, lake red C, rose bengal, eosin red. And alizarin lake.

Examples of blue pigments include bitumen, cobalt blue, alkali blue lake, Victoria blue lake, fast sky blue, indanthrene blue BC, ultramarine blue, phthalocyanine blue, and phthalocyanine green. Examples of purple pigments include manganese purple, fast violet B, and methyl violet lake.
Examples of the green pigment include chromium oxide, chromium green, pigment green B, malachite green lake, and final yellow green G. Examples of white pigments include zinc white, titanium oxide, antimony white, and zinc sulfide. Examples of extender pigments include barite powder, barium carbonate, clay, silica, white carbon, talc, and alumina white.
Examples of the dye include various dyes such as basic, acidic, dispersed, and direct dyes, such as nigrosine, methylene blue, rose bengal, and quinoline yellow.

The colorant used in the exemplary embodiment is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, light resistance, OHP permeability, and dispersibility in the toner. The colorant is preferably added in the range of 4% by mass to 15% by mass with respect to the total solid content of the toner in order to ensure the color developability at the time of fixing. It is more preferable to add in the range. However, when a magnetic material is used as the black colorant, it is preferably added in the range of 12% by mass to 48% by mass, and more preferably in the range of 15% by mass to 40% by mass.
By selecting the type of the colorant, each color toner such as yellow toner, magenta toner, cyan toner and black toner can be obtained.

The other components that can be used in the present embodiment are not particularly limited and can be selected according to the purpose. Examples thereof include various known additives such as inorganic particles, organic particles, charge control agents, and metal elements. .
The inorganic particles are generally used for the purpose of improving toner fluidity. Examples of the inorganic particles include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, cerium chloride. , Particles of bengara, chromium oxide, cerium oxide, antimony trioxide, magnesium oxide, silicon carbide, silicon nitride and the like. Among these, silica particles are preferable, and silica particles that have been hydrophobized are particularly preferable.

  The average primary particle diameter (number average particle diameter) of the inorganic particles is preferably in the range of 1 nm to 1000 nm, and the addition amount (external addition) is 0.01 parts by mass or more with respect to 100 parts by mass of the toner. A range of 20 parts by mass or less is preferable.

The organic particles are generally used for the purpose of improving cleaning properties, transfer properties, and charging properties. Examples of the organic particles include particles such as polystyrene, polymethyl methacrylate, polyvinylidene fluoride, and polystyrene-acrylic copolymer.
The charge control agent is generally used for the purpose of improving chargeability. Examples of the charge control agent include salicylic acid metal salts, metal-containing azo compounds, nigrosine and quaternary ammonium salts.

Although due to the addition of the aggregating agent, in the toner according to the exemplary embodiment, at least one metal element selected from aluminum, zinc, and calcium is added in an element composition ratio of 0.003 to 0.15% by mass. It is preferable to include the following. Among these, an aluminum element is preferable from the viewpoint of crosslinking density.
In addition, content of the said metal element is calculated | required from the total elemental analysis by a fluorescent X ray apparatus. As a sample, 6 g of toner was pressure-molded with a pressure molding machine with a load of 10 t and a pressurization time of 1 minute, and a fluorescent X-ray (XRF-1500) manufactured by Shimadzu Corporation was used. The measurement conditions were a tube voltage of 40 kV and a tube current of 90 mA. By measuring at a measurement time of 30 minutes, it can be determined from the elemental composition ratio. The numerical values described in the present specification are values measured by the above method.

-Toner structure and characteristics-
In this embodiment, it is preferable that the surface of the toner is covered with a surface layer. The surface layer is desirably thin, and when a resin coating layer is used, specifically, it is preferably within a range of 0.05 μm or more and 0.5 μm or less. In the case of a particle coating layer, the particle diameter is preferably 0.5 μm or less.

In order to form a thin surface layer with the above layer thickness, latex is adhered to the surface of toner particles including binder resin, its particles, colorant, inorganic particles that can be added, and other materials. Alternatively, it is preferable to adsorb and smooth the particles to form a coating layer.
Further, a method of adsorbing a raw material monomer of the resin and coating the resin while performing graft polymerization, interfacial polymerization, or chemical treatment may be used, but a method capable of simplifying the process of producing the toner is preferable.

  The volume average particle size of the toner in the exemplary embodiment is preferably in the range of 4 μm to 9 μm, more preferably in the range of 4.5 μm to 8.5 μm, and still more preferably in the range of 5 μm to 8 μm. .

  The volume average particle size can be measured using a Coulter Multisizer II (manufactured by Beckman Coulter, Inc.) with an aperture diameter of 50 μm. At this time, the measurement was performed after the toner was dispersed in an electrolyte aqueous solution (Isoton aqueous solution) and dispersed by ultrasonic waves for 30 seconds or more.

  In addition, the toner in the present exemplary embodiment preferably has a spherical shape with a shape factor SF1 in the range of 110 to 140. When the shape is spherical in this range, transfer efficiency and image density are improved, and high-quality image formation can be performed. The shape factor SF1 is more preferably in the range of 115 to 138.

Here, the shape factor SF1 is obtained by the following equation (5).
SF1 = (ML ² / A) × (π / 4) × 100 (5)
In the above formula (5), ML represents the absolute maximum length of the toner particles, and A represents the projected area of the toner particles. The SF1 is quantified mainly by analyzing a microscope image or a scanning electron microscope (SEM) image using an image analyzer, and can be calculated as follows, for example. That is, an optical microscope image of toner particles dispersed on the surface of a slide glass is taken into a Luzex image analyzer through a video camera, the maximum length and projected area of 100 particles are obtained, calculated by the above equation (5), and an average value thereof Is obtained.

-Manufacture of toner-
Next, a method for producing the toner will be described.
As a method for producing the toner, an aggregation and coalescence method that facilitates shape control and resin coating layer formation is preferable. The agglomeration coalescence method is a mixing step of mixing a resin particle dispersion in which resin particles are dispersed, a colorant particle dispersion in which colorant particles are dispersed, and a dispersed release agent particle dispersion, and the resin particles, The agglomeration step of forming an agglomerated particle dispersion of the colorant particles and the release agent particles is fused and united by heating to a temperature above the glass transition temperature of the resin particles (or above the melting point of the crystalline polyester). It is a manufacturing method having a fusion / unification process.

  Specifically, in general, a resin particle dispersion is prepared by an emulsion polymerization method, a phase inversion emulsification method, etc., and an ionic surfactant, a colorant particle dispersion, and a release agent particle dispersion are mixed to obtain an ionic interface. Aggregated particles having a toner diameter are formed by causing heteroaggregation with an aggregating agent having a polarity opposite to that of the activator, and then heated to a temperature equal to or higher than the glass transition temperature of the resin particles to fuse and coalesce the aggregated particles. Then, it is washed and dried to obtain a toner.

In particular, when a vinyl resin is used as the amorphous resin, a resin particle dispersion can be prepared by performing emulsion polymerization of a vinyl monomer using an ionic surfactant or the like. In addition, in the case of other resins, if the resin is soluble in an oily solvent with relatively low solubility in water, the resin is dissolved in those solvents, and a homogenizer together with an ionic surfactant or polymer electrolyte in water. A resin particle dispersion can be prepared by dispersing the particles in water using a disperser and then evaporating the solvent by heating or decompressing.
Alternatively, water is gradually added dropwise to a resin melted in a solvent at a high temperature, and the resin is dispersed as particles in water by phase inversion from a W / O emulsion to an O / W emulsion. By evaporating, a resin particle dispersion can be prepared.

Examples of the disperser used for dispersing the resin particle dispersion include a homogenizer, a homomixer, a pressure kneader, an extruder, and a media disperser.
The size of the resin particles is preferably in the range of 0.01 μm to 1.0 μm in terms of the average particle size (volume average particle size), more preferably 0.03 μm to 0.6 μm, and more preferably 0.03 μm to 0.03 μm. 4 μm or less is more desirable. In addition, the volume average particle diameter of the resin particles is measured with a laser diffraction particle size distribution analyzer (LA-700, manufactured by Horiba, Ltd.).

  The colorant is dispersed by a publicly known method. A high-pressure opposed collision type disperser or the like is preferably used.

  The center diameter (median diameter) of the colorant particles is preferably in the range of 100 nm to 330 nm, and more preferably in the range of 100 nm to 280 nm.

  With regard to the release agent, for example, it is dispersed in water together with an ionic surfactant, a polymer electrolyte such as a polymer acid or a polymer base, and is heated using a homogenizer or a pressure discharge type disperser while being heated above the melting temperature. By applying shearing, particles can be formed, and a dispersion of release agent particles of 1 μm or less can be prepared. The concentration of the surfactant used in the release agent dispersion is preferably 4% by mass or less with respect to the release agent.

  For example, the release agent is dispersed in the toner as particles having a volume average particle size in the range of 150 nm to 300 nm and contained in the range of 5% by mass to 25% by mass. Can be improved. A more preferable range is that the volume average particle diameter is 180 nm or more and 280 nm or less.

  Zirconium element can be added directly in the agglomeration step, but it is preferable to add the zirconium element dispersion to the agglomeration step after preparation. As a method for producing the zirconium element dispersion liquid, a cavitation mill such as a nanomizer, a high-pressure opposed collision type disperser such as an optimizer, or the like is used. The central diameter of the zirconium element is preferably in the range of 20 nm to 500 nm, and more preferably 30 nm to 300 nm.

  Examples of the surfactant used for the purpose of emulsion polymerization of the resin particles, dispersion of the colorant, dispersion of the release agent, aggregation thereof, stabilization thereof, and the like include sulfate ester, sulfonate, phosphate Anionic surfactants such as soaps and soaps, and cationic surfactants such as amine salt types and quaternary ammonium salt types can be used. It is also effective to use a nonionic surfactant such as polyethylene glycol, alkylphenol ethylene oxide adduct, and polyhydric alcohol. As these dispersing means, general means such as a rotary shear type homogenizer, a ball mill having a medium, a sand mill, a dyno mill and the like can be used.

  When using colorant particles coated with polar resin particles, the resin and colorant are dissolved and dispersed in a solvent (water, surfactant, alcohol, etc.), and then the above-mentioned appropriate dispersant (including the active agent). In addition, the coloring agent particles are fixed to the surface of the resin particles prepared by emulsion polymerization by dispersing in water, heating and decompressing, or by mechanical shearing force or electric adsorption force. A method etc. can be adopted.

  In the aggregation step, first, for example, the obtained crystalline polyester particle dispersion, amorphous polyester particle dispersion, colorant dispersion, release agent dispersion, and zirconium element dispersion are mixed and mixed. The liquid is heated and aggregated at a temperature not higher than the glass transition temperature of the amorphous polyester to form aggregated particles. Aggregated particles are formed by acidifying the pH of the mixed solution with stirring. As pH, the range of 2-7 is desirable, The range of 2.2-6 is more desirable, The range of 2.4-5 is further more desirable. At this time, it is also effective to use a flocculant. These are heated and agglomerated while being stirred and mixed.

  As the flocculant to be used, a surfactant having a reverse polarity to the surfactant used for the dispersant, an inorganic metal salt, and a metal complex having a valence of 2 or more can be preferably used. In particular, the use of a metal complex is particularly desirable because the amount of the surfactant used can be reduced and the charging characteristics are improved.

  Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate, and polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. Examples thereof include inorganic metal salt polymers. Of these, aluminum salts and polymers thereof are particularly preferred. In order to obtain a sharper particle size distribution, it is more suitable that the valence of the inorganic metal salt is bivalent than monovalent, trivalent than bivalent, and tetravalent than trivalent.

  When producing toner particles, it is desirable to first add only the resin particle dispersion into the agglomeration system, and after aggregating only the resin particles, it is preferable to add the colorant or release agent dispersion. . Thereby, inhibition of the aggregation of the resin particles due to the presence of the release agent particles or the like can be avoided, and the above-described desirable toner particle structure can be obtained efficiently.

  Further, when the aggregated particles have reached a desired particle size, a toner having a configuration in which the surface of the core aggregated particles is coated with amorphous polyester may be prepared by adding amorphous polyester particles. In the case of additional addition, a flocculant may be added or pH adjustment may be performed before additional addition.

  In the fusion and coalescence process, the agglomeration is stopped by increasing the pH of the suspension of aggregated particles to a range of 3 to 9 under stirring conditions in accordance with the aggregation process. The aggregated particles are fused by heating at a temperature equal to or higher than the melting temperature. Further, when coated with the amorphous polyester, the amorphous polyester is also fused to coat the core aggregated particles. The heating time may be performed to the extent that fusion is performed, and may be performed for 0.5 hour or more and 10 hours or less.

  After completion of the fusion / unification, a desired toner can be obtained through any washing step, solid-liquid separation step, and drying step. However, the washing step uses ion-exchanged water in order to develop and maintain chargeability. It is preferable to perform substitution cleaning. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration, centrifugal filtration, decanter and the like are preferably used from the viewpoint of productivity. Further, the drying process is not particularly limited, but from the viewpoint of productivity, aeration drying apparatus, spray drying apparatus, rotary drying apparatus, air flow drying apparatus, fluidized bed drying apparatus, heat transfer heating type drying apparatus, freeze drying apparatus, etc. are preferably used. It is done.

  Furthermore, metal salts such as calcium carbonate, metals such as silica, alumina, titania, barium titanate, strontium titanate, calcium titanate, cerium oxide, zirconium oxide, magnesium oxide, etc. for the purpose of imparting fluidity and improving cleaning properties Inorganic particles such as oxide compounds, ceramics, and carbon black, and resin particles such as vinyl resin, polyester, and silicone can be added to the toner surface by applying a shearing force in a dry state.

  These inorganic particles are preferably surface-treated with a coupling agent or the like in order to control conductivity, chargeability, and the like. Specific examples of the coupling agent include methyltrichlorosilane, methyldichlorosilane, and dimethyldichlorosilane. , Trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltri Ethoxysilane, diphenyldiethoxysilane, isobutyltrimethoxysilane, decyltrimethoxysilane, hexamethylsilazane, N, N- (bistrimethylsilyl) acetamide, N, -Bis (trimethylsilyl) urea, tert-butyldimethylchlorosilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, β- (3.4 epoxycyclohexyl) ethyltrimethoxysilane, Silane coupling agents and titanium coupling agents such as γ-glycidoxy propyl trimethoxy silane, γ-glycidoxy propyl methyl diethoxy silane, γ-mercaptopropyl trimethoxy silane, γ-chloropropyl trimethoxy silane, etc. Etc.

  As a method for adding particles, after the toner is dried, the toner may be attached to the toner surface by a dry method using a mixer such as a V blender or a Henschel mixer, or the particles may be added to water or an aqueous liquid such as water / alcohol. After being dispersed, it may be added to the toner in a slurry state and dried to allow an external additive to adhere to the toner surface. Moreover, you may dry, spraying a slurry on dry powder.

(Developer)
Next, the developer in this embodiment will be described.
The developer is not particularly limited except that it contains the toner in the present embodiment, and can have a component composition depending on the purpose. The developer in the present embodiment becomes a one-component developer when the toner is used alone, and becomes a two-component developer when the toner and carrier are used in combination.

The carrier is not particularly limited, and examples thereof include known carriers. For example, known carriers such as resin-coated carriers described in JP-A-62-39879, JP-A-56-11461, etc. Is mentioned.
Specific examples of the carrier include the following resin-coated carriers. Examples of the core particles of the carrier include normal iron powder, ferrite, and magnetite molding, and the volume average particle size is in the range of about 30 μm to 200 μm.

  Examples of the coating resin of the resin-coated carrier include styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, lauryl acrylate, and 2-ethylhexyl acrylate. Α-methylene fatty acid monocarboxylic acids such as methyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate; nitrogen-containing acrylics such as dimethylaminoethyl methacrylate; vinyl nitriles such as acrylonitrile and methacrylonitrile Vinyl pyridines such as 2-vinyl pyridine and 4-vinyl pyridine; vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone Homopolymers such as vinyl ketones such as ethylene; olefins such as ethylene and propylene; vinyl-based fluorine-containing monomers such as vinylidene fluoride, tetrafluoroethylene and hexafluoroethylene; and copolymers comprising two or more types of monomers, Furthermore, silicone resins including methylsilicone, methylphenylsilicone, etc., polyesters containing bisphenol, glycol, etc., epoxy resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, polycarbonate resins and the like can be mentioned. These resins may be used alone or in combination of two or more. The coating amount of the coating resin is preferably in the range of about 0.1 to 10 parts by mass and more preferably in the range of 0.5 to 3.0 parts by mass with respect to 100 parts by mass of the core particles. preferable.

For the production of the carrier, a heating kneader, a heating Henschel mixer, a UM mixer, or the like can be used. Depending on the amount of the coating resin, a heating fluidized rolling bed, a heating kiln, or the like can be used. .
In the developer used in the exemplary embodiment, the mixing ratio of the toner and the carrier is not particularly limited and can be selected according to the purpose.

  Hereinafter, although an example and a comparative example are given and the present invention is explained more concretely, the present invention is not limited to the following examples.

<Preparation of crystalline polyester dispersion (C8 / C9)>
・ 100 parts of 1,8-octanedicarboxylic acid (on a molar basis)
・ 100 parts of 1,9-nonanediol (on a molar basis)
The above components were put into a reaction vessel equipped with a stirrer, a thermometer, a condenser, and a nitrogen gas introduction pipe, and the inside of the reaction vessel was replaced with dry nitrogen gas, and then 0.1 parts of titanium tetrabutoxide was added to 100 parts by mass of the monomer component. Twenty-five parts by mass was added, and the reaction was stirred at 170 ° C. for 10 hours under a nitrogen gas stream. Furthermore, the temperature was raised to 210 ° C., the pressure in the reaction vessel was reduced to 3 kPa, and the reaction was stirred for 12 hours under reduced pressure to obtain a crystalline polyester.

Next, 200 parts by mass of the crystalline polyester was put into 800 parts by mass of distilled water, heated to 85 ° C., adjusted to pH 9.0 with ammonia, and an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd.). (Product: Neogen RK) 0.4 parts by mass (as an active ingredient) was added. While being heated to 85 ° C., it was dispersed at 8000 rpm for 5 minutes with a homogenizer (IKA Japan, Inc .: Ultra Tarax T50), and then subjected to a dispersion treatment corresponding to 10 passes at 110 ° C. using a pressure discharge type gorin homogenizer. A conductive polyester dispersion (C8 / C9) was prepared.
The crystalline polyester in the obtained crystalline polyester dispersion (C8 / C9) has a weight average molecular weight Mw = 26000, a number average molecular weight Mn = 11000, an oxidation AV = 9.3 mgKOH / g, a melting point Tc = 71.5 ° C., The volume average particle size was 220 nm and the solid content was 20% by mass.

<Preparation of crystalline polyester dispersion (C10 / C9)>
・ 100 parts of 1,10-decanedicarboxylic acid (molar basis)
・ 100 parts of 1,9-nonanediol (on a molar basis)
A crystalline polyester is obtained by the method described in <Preparation of Crystalline Polyester Dispersion (C8 / C9)> except that the above components are used in place of 1,8-octanedicarboxylic acid and 1,9-nonanediol. A crystalline polyester dispersion (C10 / C9) was prepared.
The crystalline polyester in the obtained crystalline polyester dispersion (C10 / C9) has a weight average molecular weight Mw = 24500, a number average molecular weight Mn = 10100, an oxidation AV = 10.5 mgKOH / g, a melting point Tc = 73.8 ° C., The volume average particle size was 240 nm and the solid content was 20% by mass.

<Preparation of amorphous polyester dispersion>
・ Bisphenol A propylene oxide adduct 100 parts (molar basis)
(Sanyo Chemical Industry Co., Ltd., New Pole BP-2P)
・ 70 parts of terephthalic acid (on a molar basis)
・ 22 parts of dodecenyl succinic anhydride (on a molar basis)
・ Trimellitic anhydride 3 parts (molar basis)
In a reaction vessel equipped with a stirrer, a thermometer, a condenser, and a nitrogen gas introduction tube, 0.17 parts by mass of the monomer other than trimellitic anhydride and tin dioctanoate with respect to 100 parts by mass of the monomer component. Then, the mixture was reacted at 235 ° C. for 6 hours under a nitrogen gas stream. Next, the temperature was lowered to 190 ° C., and the trimellitic anhydride was added and reacted for 1 hour. Further, the temperature was raised to 220 ° C. over 4 hours, and polymerization was performed under a pressure of 10 kPa until a desired molecular weight was obtained, thereby obtaining a light yellow transparent amorphous polyester. Next, a considerable amount of a mixed solvent of ethyl acetate and isopropyl alcohol capable of dissolving the resin was charged into a 5 L separable flask. The amorphous polyester was gradually added thereto, stirred with a three-one motor, and dissolved to obtain an oil phase. An appropriate amount of dilute aqueous ammonia solution is added dropwise to the stirred oil phase, and ion-exchanged water is added dropwise to effect phase inversion emulsification. Further, the solvent is removed while reducing the pressure with an evaporator. A surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK) was added in an amount of 2% by mass (as an active ingredient) based on the amount of resin, and then the pH was adjusted to 3.0 using nitric acid to make it amorphous A polyester dispersion was obtained.
The amorphous polyester in the obtained amorphous polyester dispersion has a glass transition point Tg = 57 ° C., a weight average molecular weight Mw = 53000, a number average molecular weight Mn = 7800, a softening temperature = 120 ° C., and an acid value = 14 mgKOH / g. The volume average particle size was 150 nm and the solid content was 20% by mass.

<Preparation of zirconia dispersion>
-Tosoh Co., Ltd. zirconia powder (TZ-3Y-E) 12 parts by mass-Anionic surfactant 0.2 parts by mass (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK, active ingredient amount: 60% by weight)
・ Ion-exchanged water 85 parts by weight Ion-exchanged water and an anionic surfactant are added to a stainless steel container whose liquid level is about 1/3 of the height of the container when all of the above components are added. And the surfactant was fully dissolved. Thereafter, all of the above materials were added, and the mixture was stirred using a stirrer until there was no wet material, and was sufficiently degassed. After defoaming, the mixture was dispersed for 10 minutes at 5000 rpm using a homogenizer (manufactured by IKA, Ultra Tarrax T50), and then defoamed by stirring for one day with a stirrer. After defoaming, the mixture was dispersed again at 6000 rpm for 10 minutes using a homogenizer, and then defoamed by stirring for one day with a stirrer. Subsequently, the dispersion liquid was dispersed at a pressure of 240 MPa using a high-pressure impact disperser ultimateizer (manufactured by Sugino Machine Co., Ltd., HJP30006). Dispersion was performed for 10 passes in terms of the total charge and the processing capacity of the apparatus. Ion exchange water was added to the resulting dispersion to adjust the solid content concentration to 5% by mass.
The volume average particle diameter D50 of the particles in the dispersion was 130 nm. As the volume average particle diameter D50, an average value of three measurement values excluding the maximum value and the minimum value out of five times measured with an LS Coulter (manufactured by Beckman Coulter) was used.

<Preparation of release agent dispersion (1)>
-270 parts by weight of release agent (manufactured by Nippon Seiki Co., Ltd., trade name: FNP0115, melting point Tw 105.0 ° C.)
Anionic surfactant 13.5 parts by mass (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK, active ingredient amount: 60% by mass)
(As an active ingredient, 3.0% by mass with respect to the release agent)
・ Ion-exchanged water 721.6 parts by mass The above components were mixed, dispersed while being heated to 95 ° C. with a homogenizer (IKA, Ultra Tarrax T50), and then pressure-discharge type homogenizer (Gorin, Gorin homogenizer). Dispersion treatment was performed to obtain a release agent dispersion. The volume average particle diameter D50 of the particles in this dispersion was 220 nm. Thereafter, ion-exchanged water was added to adjust the solid content concentration to 20.0% by mass to obtain a release agent dispersion (1).

<Preparation of release agent dispersion (2)>
The release agent was dispersed by the method described in the preparation of the release agent dispersion (1), except that “Nippon Seiki Co., Ltd., trade name: FNP0090, melting point Tw 89.7 ° C.” was used as the release agent. A liquid (2) was obtained.

<Preparation of release agent dispersion (3)>
The release agent was dispersed by the method described in the preparation of the release agent dispersion (1), except that “Nippon Seiki Co., Ltd., trade name: HNP3, melting point Tw 65.7 ° C.” was used as the release agent. A liquid (3) was obtained.

<Preparation of release agent dispersion (4)>
The release agent was dispersed by the method described in the preparation of the release agent dispersion (1) except that “Nippon Seiki Co., Ltd., trade name: FNP0105, melting point Tw101.1 ° C.” was used as the release agent. A liquid (4) was obtained.

<Preparation of colorant dispersion>
・ 200 parts by weight of colorant (Cabot Japan KK, trade name: Regal 330)
・ 33 parts by weight of anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK, active ingredient amount: 60% by mass)
(As an active ingredient, 10.0% by mass with respect to the colorant)
・ Ion-exchanged water 780 parts by mass In a stainless steel container whose liquid level is about 1/3 of the height of the container when all of the above components are added, ion-exchanged water and an anionic surfactant are added. And the surfactant was fully dissolved. Thereafter, all of the above materials were added, and the mixture was stirred using a stirrer until there was no wet material, and was sufficiently degassed. After defoaming, the mixture was dispersed for 10 minutes at 5000 rpm using a homogenizer (manufactured by IKA, Ultra Tarrax T50), and then defoamed by stirring for one day with a stirrer. After defoaming, the mixture was dispersed again at 6000 rpm for 10 minutes using a homogenizer, and then defoamed by stirring for one day with a stirrer. Subsequently, the dispersion liquid was dispersed at a pressure of 240 MPa using a high-pressure impact disperser ultimateizer (manufactured by Sugino Machine Co., Ltd., HJP30006). Dispersion was performed for 10 passes in terms of the total charge and the processing capacity of the apparatus. Ion exchange water was added to the resulting dispersion to adjust the solid content concentration to 15% by mass.
The volume average particle diameter D50 of the particles in the dispersion was 100 nm. For the volume average particle diameter D50, an average value of three measured values excluding the maximum value and the minimum value out of five times measured by Microtrac UPA (manufactured by Nikkiso Co., Ltd.) was used.

<Manufacture of carriers>
Ferrite particles (volume average particle size: 35 μm) 500 parts by mass Toluene 70 parts by mass Perfluorooctylethyl methacrylate /
Methacrylate copolymer (copolymerization ratio: 15/85) 10 parts by mass Carbon black (VXC72: manufactured by Cabot Corporation) 1.0 part by mass First, the components except for the ferrite particles are mixed and stirred for 10 minutes in a sand mill. A coating liquid in which carbon black was dispersed was prepared. Next, this coating liquid and ferrite particles are put into a vacuum degassing type kneader, and while stirring, the pressure is reduced to 9.87 × 10 ⁴ Pa (−20 mHg) at 60 ° C., followed by mixing for 30 minutes, and then the temperature is increased / decreased. The carrier was obtained by stirring and drying at 90 ° C. at 5.33 × 10 ³ Pa (−720 mHg) for 30 minutes.

[Example 1]
-Crystalline polyester dispersion (C10 / C9) 85 parts by mass-Amorphous polyester resin dispersion 630 parts by mass-Zirconia dispersion 0.55 parts by mass-Release agent dispersion (2) 128 parts by mass-Colorant dispersion Liquid 110 parts by mass ・ Ion-exchanged water 220 parts by mass The above components were put into a 3 liter reaction vessel equipped with a thermometer, a pH meter, and a stirrer, and 5000 rpm was obtained with a homogenizer (manufactured by IKA Japan: Ultra Tarax T50). Then, 75 parts by mass of 1.0 mass% ammonium sulfate aqueous solution was added and dispersed for 6 minutes. Thereafter, a stirrer and a mantle heater were installed in the reaction vessel, and the temperature was raised at 0.05 ° C./min while adjusting the rotation speed of the stirrer so that the slurry was sufficiently stirred. Diameter: 50 μm, manufactured by Beckman-Coulter), and when the volume average particle diameter reached 5.0 μm, 350 parts by mass of an amorphous polyester resin dispersion was added. After the addition for 30 minutes, the pH was adjusted to 9.0 using a 5 mass% aqueous sodium hydroxide solution. Thereafter, while adjusting the pH to 9.0 every 5 ° C., the temperature was raised to 90 ° C. at a temperature rising rate of 1 ° C./min and held at 90 ° C. When the particle shape and surface property were observed with an optical microscope and a scanning electron microscope (FE-SEM) every 15 minutes, coalescence of the particles was confirmed at 1.0 hour. Cooled to 5 ° C. in 5 minutes.
The slurry after cooling was passed through a mesh with an opening of 20 μm to remove coarse powder, and then the reaction product was filtered under reduced pressure with an aspirator and washed with ion-exchanged water. When the filtrate had a conductivity of 10 mS or less, water flow was stopped and solid-liquid separation was performed. The separated cake-like particles are vacuum-dried in an oven at 40 ° C. for 24 hours, and the obtained powder is crushed in a sample mill and then vacuum-dried in an oven at 40 ° C. for 5 hours. Toner particles were obtained.
To 100 parts by mass of the obtained toner particles, 1.0 part by mass of hydrophobic silica (manufactured by Nippon Aerosil Co., Ltd., RY50) and 0.8 part by mass of hydrophobic titanium oxide (manufactured by Nippon Aerosil Co., Ltd., T805) are added, Using a sample mill, the mixture was blended at 13000 rpm for 30 seconds. Thereafter, the mixture was sieved with a vibration sieve having an opening of 45 μm to obtain toner (A1). The obtained toner had a volume average particle size of 6.0 μm, a shape factor of 0.960 (manufactured by Sysmex Corporation, FPIA-3000), and a zirconium element content of 0.001% by mass.

  After adding 40 parts by mass of the toner to 500 parts by mass of the carrier and blending for 20 minutes with a V-type blender, aggregates were removed by a vibrating screen having an aperture of 212 μm to obtain a developer (A1). Further, after adding 100 parts by mass of the toner to 20 parts by mass of the carrier and blending with a V-type blender for 20 minutes, the aggregate is removed by a vibrating screen having an aperture of 212 μm, and a replenishing developer (A1) is obtained. Obtained.

[Examples 2 to 5 and Comparative Examples 1 to 3]
Toners (A2) to (A5) and (B1) to (B1) are prepared by the method described in Example 1 except that the addition amount of the zirconia dispersion is adjusted so that the content of the zirconium element becomes the value described in Table 1 below. (B3) was obtained. Furthermore, developers (A2) to (A5) and (B1) to (B3) and replenishment developers (A2) to (A5) and (B1) to (B3) were obtained.

= Evaluation method =
The fixing device was removed, and the developer was set in the developing device of DocuCentre 505 (manufactured by Fuji Xerox Co., Ltd.) modified so as to produce an unfixed image, and the developer for replenishment was set in the toner cartridge. First, 20 sheets of A3 size C2r paper (manufactured by Fuji Xerox Office Supply Co., Ltd.) were passed through in an environmental room at a temperature of 25 ° C. and a relative humidity of 60% to charge the toner. Next, the developing toner amount of the single color solid image on the paper was adjusted to 4.5 g / m ² .

  The fixing device removed from the DocuCentre 505 is a bench modified so that it can be fixed off-line. The angle α in the fixing device (the angle on the heating member side formed by the tangent line drawn in the contact area between the heating member and the pressure member and the horizontal plane) ) Was set at the angles shown in Table 1 below.

A solid image of 150 mm × 150 mm was output to the center of the C2r paper, and the fixing device temperature was fixed at the temperature shown in Table 1 below. Place a SUS304 plate with a width of 25 mm x length of 250 mm x thickness of 1 mm on the image surface so that it passes through the center of the output image and is perpendicular to the paper vertical direction, and a glass plate larger than the entire image is placed on it. It was. Nine weights with a weight of 250 g were placed on the glass plate evenly and left in an environmental room at a temperature of 25 ° C. and a relative humidity of 60% for 10 days.
Measure the glossiness of the image surface of the image surface that was in contact with the SUS board after it had been left at 5 locations in the length direction, 3 times each, 5 from the higher glossiness and 5 from the lower glossiness The average value of the data from which the above data was deleted was defined as the image glossiness. In addition, the glossiness was measured three times for each of the six areas of the image surface where the SUS plate was not in contact, and the average of the data obtained by deleting the five data from the higher glossiness and the five data from the lower glossiness. The value was the image glossiness. The difference in glossiness was evaluated according to the following criteria.
○: Glossiness difference is less than 3 △: Glossiness difference is 3 or more and less than 5 ×: Glossiness difference is 5 or more

[Example 6]
The toner (A6) was prepared by the method described in Example 1 except that the crystalline polyester used, the crystalline polyester content Ac, the release agent used, and the release agent content Aw were changed to those shown in Table 2 below. Got.

  After adding 40 parts by mass of the toner to 500 parts by mass of the carrier and blending for 20 minutes with a V-type blender, aggregates were removed by a vibrating screen having an aperture of 212 μm to obtain a developer (A6). Further, after adding 100 parts by mass of the toner to 20 parts by mass of the carrier and blending for 20 minutes with a V-type blender, the aggregates are removed by a vibration sieve having an aperture of 212 μm, and a replenishment developer (A6) is obtained. Obtained.

[Examples 7 to 11 and Comparative Examples 4 to 6]
The toner (A7) was prepared by the method described in Example 6 except that the crystalline polyester used, the crystalline polyester content Ac, the release agent used, and the release agent content Aw were changed to those shown in Table 2 below. ) To (A11) and (B4) to (B6) were obtained. Furthermore, developers (A7) to (A11) and (B4) to (B6) and replenishment developers (A7) to (A11) and (B4) to (B6) were obtained.

  An evaluation test was performed by the method described in Example 1 except that the developer α and the replenishment developer were used and the angle α and the fixing device temperature in the fixing device were set to the temperatures shown in Table 2 below.

1 is a schematic configuration diagram illustrating an example of an image forming apparatus of the present invention. FIG. 3 is an enlarged view illustrating an example of a configuration of a fixing device according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Document 2 Illumination 3 Color scanner 4 Image processing apparatus 5 Laser diode 6 Optical system 7 Charger 8 Organic photoreceptor 9 Yellow developing device 10 Magenta developing device 11 Cyan developing device 12 Black developing device 13 Intermediate transfer belt 14 Transfer corotron 15 and 16 Transfer roll 17 Recording medium 19 Conveying device 20 Heating member 22 Heating source 24 Core metal 26 Surface resin tube layer 30 Pressure member 40 Recording medium reversing means

Claims (6)

A latent image forming step for forming a latent image on an image carrier, a developing step for developing the latent image into a toner image with a developer containing toner containing at least crystalline polyester, and the obtained toner image as a recording medium An image forming method comprising: a transfer step of transferring the toner image; and a fixing step of fixing the transferred toner image to a recording medium by a fixing unit, and satisfying the following [Condition 1] to [Condition 5 ]: Method.
[Condition 1]
The crystalline polyester includes at least one selected from HOOC— (CH ₂ ) ₈ —COOH and HOOC— (CH ₂ ) ₁₀ —COOH as an acid component, and HO— (CH ₂ ) ₆ —OH and HO as an alcohol component. A polyester resin reacted with at least one selected from — (CH ₂ ) ₉ —OH, and has a melting point of 67 ° C. or higher and 75 ° C. or lower by differential scanning calorimetry.
[Condition 2]
The toner contains 3% by mass to 9% by mass of the crystalline polyester as a binder resin.
[Condition 3]
In accordance with ASTM D3418-8, the formed fixed image was heated at a temperature increase rate of 10 ° C. per minute as the first measurement in a measurement temperature range of 10 ° C. to 150 ° C. and held for 5 minutes after reaching 150 ° C. Then, in the DSC spectrum measured through a step of cooling to 10 ° C. at a temperature drop rate of −10 ° C. and holding for 5 minutes and then raising the temperature to 150 ° C. at a temperature increase rate of 10 ° C./min as the second measurement, The temperature rising spectrum of the first DSC measurement has a minimum value M1 in the range of 57 ° C. or more and 73 ° C. or less, and the absolute value of the spectrum intensity (depth) from the baseline to the minimum value in M1 is M1p,
Further, when the temperature rise spectrum of the second DSC measurement has a minimum value M2 in the range of 57 ° C. or more and 73 ° C. or less, and the absolute value of the spectrum intensity (depth) from the baseline to the minimum value in M2 is M2p. ,
Said M1p and M2p satisfy | fill the relationship of following formula (1) and Formula (2).
Formula (1) 1.5 * M1p <= M2p <= 5 * M1p
Formula (2) 60 (mW / g) ≦ M2p ≦ 150 (mW / g)
[Condition 4]
The content of zirconium element in the toner is 0.001% by mass or more and 1.0% by mass or less.
[Condition 5]
The fixing means includes at least a heating member and a pressure member, and the heating member is arranged to form a lower side in a contact area with the pressure member, and the image surface on which the recording medium is fixed Is discharged downward. The image forming method according to claim 1 in which the temperature during the fixing of prior SL pressurized heat member is characterized in that at 240 ° C. or less 190 ° C. or higher. The toner contains at least a release agent;
When the melting point of the crystalline polyester is Tc (° C.) and the melting point of the release agent is Tw (° C.), the following formula (3) is satisfied:
And Ac the content of the crystalline polyester in the toner, the Aw of the content of the release agent, when, according to claim 1 or claim 2, characterized in that satisfies the following formula (4) Image forming method.
Formula (3) Tc-10 ≦ Tw ≦ Tc + 30
Formula (4) Aw × 0.4 ≦ Ac ≦ Aw × 0.9 A latent image forming means for forming a latent image on an image carrier, a developing means for developing the latent image into a toner image with a developer containing a toner containing at least crystalline polyester, and the obtained toner image as a recording medium An image forming apparatus comprising: transfer means for transferring the toner image; and fixing means for fixing the transferred toner image to a recording medium, wherein the following [Condition 1] to [Condition 5 ] are satisfied.
[Condition 1]
The crystalline polyester includes at least one selected from HOOC— (CH ₂ ) ₈ —COOH and HOOC— (CH ₂ ) ₁₀ —COOH as an acid component, and HO— (CH ₂ ) ₆ —OH and HO as an alcohol component. A polyester resin reacted with at least one selected from — (CH ₂ ) ₉ —OH, and has a melting point of 67 ° C. or higher and 75 ° C. or lower by differential scanning calorimetry.
[Condition 2]
The toner contains 3% by mass to 9% by mass of the crystalline polyester as a binder resin.
[Condition 3]
In accordance with ASTM D3418-8, the formed fixed image was heated at a temperature increase rate of 10 ° C. per minute as the first measurement in a measurement temperature range of 10 ° C. to 150 ° C. and held for 5 minutes after reaching 150 ° C. Then, in the DSC spectrum measured through a step of cooling to 10 ° C. at a temperature drop rate of −10 ° C. and holding for 5 minutes and then raising the temperature to 150 ° C. at a temperature increase rate of 10 ° C./min as the second measurement, The temperature rising spectrum of the first DSC measurement has a minimum value M1 in the range of 57 ° C. or more and 73 ° C. or less, and the absolute value of the spectrum intensity (depth) from the baseline to the minimum value in M1 is M1p,
Further, when the temperature rise spectrum of the second DSC measurement has a minimum value M2 in the range of 57 ° C. or more and 73 ° C. or less, and the absolute value of the spectrum intensity (depth) from the baseline to the minimum value in M2 is M2p. ,
Said M1p and M2p satisfy | fill the relationship of following formula (1) and Formula (2).
Formula (1) 1.5 * M1p <= M2p <= 5 * M1p
Formula (2) 60 (mW / g) ≦ M2p ≦ 150 (mW / g)
[Condition 4]
The content of zirconium element in the toner is 0.001% by mass or more and 1.0% by mass or less.
[Condition 5]
The fixing means includes at least a heating member and a pressure member, and the heating member is arranged to form a lower side in a contact area with the pressure member, and the image surface on which the recording medium is fixed Is discharged downward. The image forming apparatus according to claim 4 in which the temperature during the fixing of prior SL pressurized heat member is characterized in that at 240 ° C. or less 190 ° C. or higher. The toner contains at least a release agent;
When the melting point of the crystalline polyester is Tc (° C.) and the melting point of the release agent is Tw (° C.), the following formula (3) is satisfied:
And Ac the content of the crystalline polyester in the toner, the Aw of the content of the release agent, when, according to claim 4 or claim 5, characterized in that satisfies the following formula (4) Image forming apparatus.
Formula (3) Tc-10 ≦ Tw ≦ Tc + 30
Formula (4) Aw × 0.4 ≦ Ac ≦ Aw × 0.9

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