JP2011107375A - Image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming method by which an image having no omission of images during transfer, excellent cleaning property and high definition can be obtained even in a high-speed developing system including a transfer conveyance belt and a wide transfer nip. <P>SOLUTION: The method is characterized in that: an intrusion amount i (mm) of a transfer conveyance belt to a photosensitive drum and the diameter d (mm) of the photosensitive drum satisfy the relationship of (1):d×0.05<i≤d×0.15; the toner comprises toner particles containing at least a binder resin and a colorant, and at least silica fine particles; the silica fine particles are treated with at least a silicone oil; and the fixation rate of the silicone oil on a carbon amount basis is 30 mass% or more and 95 mass% or less. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image forming method for visualizing an electrostatic charge image in electrophotography.

  Conventionally, many methods are known as electrophotographic methods. Generally, a charging step for charging a photoconductor using a photoconductive substance, and a step for forming an electrostatic latent image on the charged photoconductor. Go through.

  Thereafter, a development process for transferring the toner carried on the toner carrier to the electrostatic latent image for visualization, a transfer process for transferring the developed image to a transfer material by a transfer means, and a transfer process on the transfer material A target fixed product is obtained through a fixing step of heating and fixing the transferred image.

  As a transfer means, a transfer medium (hereinafter referred to as a transfer and transport belt) such as an endless belt is used from the viewpoint of stability of transportability and transfer quality, and the transfer material is sandwiched and transported between the photosensitive member and the toner. Transfer means for electrostatically transferring an image onto a transfer material has been used.

  At this time, the toner remaining on the transfer / conveying belt by the transfer is removed by the transfer / conveying belt cleaner to prepare for the next image forming process.

  By the way, in recent electrophotographic apparatuses for light printing (hereinafter referred to as POD), high image quality, high-speed printing, high durability, and the like are more severely demanded. Size). For this reason, transfer means using a transfer / conveying belt are regarded as important from the viewpoints of stability of conveyance and further improvement of transfer quality.

  Patent Document 1 describes that the image quality can be improved by increasing the transfer pressure between the photosensitive member and the transfer conveyance belt to widen the transfer nip and providing an ultrasonic vibrator in the transfer nip portion. There is. Widening the transfer nip is an advantageous direction from the viewpoint of preventing toner transfer splattering and the stability of transfer material transportability. It tends to cause image quality degradation. In the above document, in order to prevent these problems, an ultrasonic vibrator is provided to improve the releasability from the photosensitive member. However, there is room for improvement in order to increase the printing speed on the premise of light printing applications and to cope with various kinds of transfer materials.

  In Patent Document 2, as an approach from the toner side, it is disclosed that a specific inorganic fine powder is contained in the toner, so that high-definition and high-quality print quality can be stably maintained over a long period of time. By inserting particles that can be used as such spacers, a certain degree of effect is exhibited. However, depending on an apparatus having a wide transfer nip and a durability mode, the spacer particles can easily work as a free external additive. As a result, a small amount of free external additive may remain on the transfer / conveying belt or the photoconductor, leading to image defects. Such free external additives are liable to hinder the cleaning properties of the photoreceptor and the transfer / conveying belt cleaner.

  Japanese Patent Application Laid-Open No. H10-228667 describes that various problems at the time of transfer can be solved by containing a toner that defines the release rate of silicone oil. However, even though the technique disclosed here can cope with a printing speed of about 60 cpm, it is difficult to say that the effect of preventing transfer dropout is sufficient when light printing is used.

  Patent Document 4 describes silica fine particles that have been treated with a silicone oil and then crushed and treated with an alkylsilazane-based treating agent to increase the degree of hydrophobicity. Although it is certainly excellent in terms of hydrophobicity, there is still room for improvement in terms of processing uniformity. If the surface treatment is non-uniform, the silica fine particles become aggregates and are difficult to uniformly adhere to the toner particle surfaces. As a result, particularly when used in a high-speed developing system, the silica fine particles are easily released from the toner particles by a mechanical share such as agitation in the developing device, which often leads to an image defect due to free silica particles. Further, the free silica particles tend to hinder the cleaning performance of the transfer / conveying belt cleaner. Furthermore, there is a description that the particle size distribution is concentrated to 10 μm or more and 70 μm or less, so that it can be dispersed quickly at the time of toner formation. However, the addition of aggregates of 10 μm or more to several micron toner particles can cause free silica particles to be dispersed. As a result, it is easy to lead to the above adverse effects.

  In this way, in a high-speed development system and an image forming method with a wide transfer nip, it is possible to obtain a high-definition image that is compatible with a wide variety of transfer materials, has no transfer gaps, has excellent cleaning properties, and There is a current situation that is difficult.

JP 2006-162704 A JP 2006-145811 A JP 2002-174926 A JP 2004-168559 A

  An object of the present invention is to provide an image forming method that solves the above-mentioned problems. That is, an object of the present invention is to provide an image forming method that has a transfer conveying belt and has a transfer nip, has a transfer nip, has no transfer dropout, has excellent cleaning properties, and can obtain a high-definition image. That is.

In order to solve the above problems, the present invention is directed to charging a photosensitive member, forming an electrostatic charge image on the charged photosensitive member, and developing the electrostatic charge image using toner on a toner carrying member. In an image forming method in which a toner image is formed thereon and the toner image is transferred to a transfer material on a transfer conveyance belt,
The transfer conveyance belt is supported by at least two rollers installed upstream and downstream in the conveyance direction with respect to the transfer position,
When the amount of penetration of the transfer / conveying belt into the photosensitive drum is i (mm) and the diameter of the photosensitive drum is d (mm), the following equation (1) is satisfied:
d × 0.05 <i ≦ d × 0.15 (1)
The toner is a toner having at least a binder resin, a toner particle containing a colorant, and at least silica fine particles;
The present invention relates to an image forming method, wherein the silica fine particles are treated with at least silicone oil, and the carbon oil-based immobilization ratio of the silicone oil is 30% by mass or more and 95% by mass or less.

  According to the present invention, even in a high-speed development system having a wide transfer nip, it is possible to provide an image forming method capable of obtaining a high-definition image having excellent transferability without causing transfer dropout.

It is the schematic of a transfer process. It is a methanol dripping transmittance | permeability curve. It is a schematic diagram of a photoreceptor. FIG. 3 is a schematic diagram of a developing device having a plurality of toner carriers.

  In a high-speed development system, it is considered that one of the means is to widen the transfer nip in order to prevent the occurrence of conveyance deviation and transfer deviation and to obtain higher transfer quality. However, it has been found that when conventional toner is used in such a wide nip transfer system, it is likely to cause transfer deficiencies, poor cleaning properties, image defects, and the like.

  In other words, in order to improve transferability, the conventional method using spacer particles and the method of increasing the hydrophobicity of external additive particles are likely to generate free particles, and are compatible with a wide variety of transfer materials while being high speed. In addition, when considering light printing applications that require high image quality, there is a current situation that is difficult.

  Therefore, the present inventors paid attention to silica fine particles on the toner surface that are in direct contact with the transfer / conveying belt and greatly affect the charging characteristics. In other words, it was thought that controlling the silica fine particles could improve the releasability and charging characteristics with respect to the transfer / conveyance belt, and further the cleaning properties of the transfer / conveyance belt.

  First, attention was focused on silicone oil, which is one of the processing agents for silica fine particles. In general, silicone oil has excellent releasability and is almost 100% immobilized on the silica base. However, in examining belt transfer and its releasability, it has been found that it is more advantageous for belt transfer when silicone oil is released to some extent during transfer. One of the indices that show this is the immobilization rate of silicone oil.

  It has been found that this index and the characteristics at the time of belt transfer are closely related. The immobilization rate of the silicone oil can be obtained by stirring the treated silica fine particles in a solvent for a long time and measuring the amount of carbon before and after stirring. Therefore, silicone oil is difficult to peel off only with simple mechanical stirring, and it is assumed that free components are likely to be generated where a different share is applied in addition to this share. If this is replaced with an electrophotographic image forming method, the adhesive force of the silicone oil to the silica base material is slightly reduced by mechanical share such as stirring in the developing device, but it is considered that it has not yet been released. . After that, it is considered that the effect is exerted by releasing from the silica raw material at a place where pressure is applied to some extent as in the belt transfer system image forming method. In particular, in a system having a large transfer nip, it is considered that the effect appears more remarkably.

  Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings, and the relationship with toner powder characteristics will be further described.

  FIG. 1 shows an example of this embodiment, and shows a schematic diagram of a transfer process and a transfer conveyance belt cleaning process.

  The photoconductor 11 is provided with a photoconductive layer on a cylindrical conductive substrate, and the transfer conveyance belt 12 has two or more arranged on the upstream side and the downstream side in the conveyance direction with respect to the transfer position. It is supported by rollers (in FIG. 1, three rollers, a driving roller 13, a driven roller 14, and a cleaning backup roller 17). These rollers are driven to rotate in the direction of the arrow by a drive motor (not shown). The transfer conveyance belt 12 conveys the transfer material 19 in the direction of the arrow while the toner on the photoconductor 11 is pressed onto the transfer material 19 at a contact portion with the photoconductor 11 (that is, the transfer nip portion) under pressure contact conditions. Transcript with.

  A bias roller 15 serving as a transfer charge applying unit that applies a transfer bias by applying a transfer bias and a high-voltage power source 16 that applies a voltage to the bias roller 15 are attached to the transfer site. The bias roller 15 is provided so as to contact the inside of the transfer conveyance belt 12 at a position slightly downstream of the transfer nip portion in the rotation direction of the transfer conveyance belt 12. The bias roller 15 constitutes a contact electrode for applying a charge having a polarity opposite to the charge polarity of the toner developed on the photoreceptor 11 to the transfer / conveying belt. The transfer charge applying means may be a charger using corona discharge or a brush-like charger.

  The installation position of the transfer charge applying unit is not limited to the downstream side in the rotation direction of the transfer conveyance belt with respect to the transfer nip portion, and may be installed in the upstream direction.

In the present invention, the transfer / conveying belt 12 needs to be pressed against the photoconductor side with an appropriate pressure from the transfer / conveying belt 12 side at a contact portion with the photoconductor 11. That is, as shown in FIG. 1, it is necessary to satisfy the relationship of the following formula (1) when the penetration amount i (mm) of the transfer conveyance belt 12 with respect to the surface of the photoreceptor 11 and the diameter of the photosensitive drum is d (mm). .
d × 0.05 <i ≦ d × 0.15 (1)

  By setting the intrusion amount as described above, the transfer material is more stably transported, which leads to further improvement in transfer quality such as prevention of toner transfer scattering.

  When the intrusion amount i is less than the photosensitive drum diameter d × 0.05, this means that the amount of contact of the transfer / conveying belt with the photosensitive drum is small. Transfer scattering is worsened. On the other hand, when the diameter of the photosensitive drum exceeds d × 0.15, it indicates that the amount of contact of the transfer / conveying belt with the photosensitive drum is large, and image quality deterioration due to transfer is likely to occur, such as transfer skipping.

  The photosensitive member d is preferably 25 mm or more and 150 mm or less in order to obtain a desired penetration amount. When the photoreceptor d is less than 25 mm, the amount of penetration is extremely small. As a result, the transferability of the transfer material becomes unstable, and toner transfer scattering deteriorates. On the other hand, if it is larger than 150 mm, the intrusion amount becomes extremely large, and image quality deterioration due to transfer is likely to occur.

  Further, at the drive roller 13 site, the transfer conveyance belt 12 and the transfer material 19 are separated by curvature separation. A fur brush 18 is installed on the cleaning backup roller 17 at a position opposite to the transfer conveyance belt 12, and the surface of the transfer conveyance belt is cleaned by rotating the transfer conveyance belt 12 in the advancing direction and the counter direction.

  As is clear from the schematic diagram of FIG. 1, when the transfer / conveyance belt is used, the toner developed on the photoreceptor is always pressed from the transfer / conveyance belt side in the transfer process. In this pressurized state, a part of the silicone oil is liberated from the silica fine particles, and the effect is exhibited. That is, since the free silicone oil exhibits a high release performance between the photosensitive member and the toner on the transfer material, image defects such as transfer dropout are unlikely to occur even in a system with a large transfer nip in which the pressing time is long.

  Further, in a system having a large transfer nip, the toner is pressed for a long time, so that the toner may be crushed and the toner image may be scattered during transfer (hereinafter referred to as transfer explosion). In particular, when transferring a line image onto cardboard, such a problem is likely to occur. However, since the free silicone oil acts as a buffer between the toner and the photoconductor, it also has an effect of preventing transfer explosion.

  The present invention is characterized in that the immobilization ratio of silica fine particles based on the carbon amount of the silicone oil is 30% by mass or more and 95% by mass or less, more preferably 60% by mass or more and 90% by mass or less. By controlling the fixing rate of the silicone oil in this way, a high-quality image can be obtained even in a transfer / conveying belt system having a wide nip.

  When the immobilization ratio is less than 30% by mass, it means that the amount of free oil is large, and the oil component tends to adhere to the photoreceptor. As a result, the free oil component that remains without being partially cleaned remains on the photoconductor, and a so-called white spot is easily generated where white spots are generated on the image. Further, a part of the free oil component remaining on the photoconductor moves from the photoconductor to the transfer conveyance belt at the paper interval portion. As a result, oil is accumulated in the transfer / conveying belt cleaning unit, leading to poor cleaning.

  On the other hand, when it is larger than 95% by mass, it indicates that there is almost no free oil, the releasability is deteriorated, and transfer omission is deteriorated. In addition, a transfer explosion is likely to occur when a cardboard is passed.

  The material of the transfer / conveying belt 12 is preferably selected from materials having low hygroscopicity and stable resistance, such as chloroprene rubber, urethane rubber, EPDM rubber, silicone rubber, and epichlorohydrin rubber. In this case, the structure which has a base material is more preferable.

  As described above, according to the present invention, by controlling the fixing rate of the silica fine particle silicone oil at the contact portion between the transfer conveyance belt and the photoconductor, it is possible to achieve high reliability, high definition, and high image quality for a long period of time. It is possible to continue to maintain.

  The measuring method of the silicone oil immobilization rate in the silica fine particles in the present invention is shown below.

<Measurement method of silicone oil immobilization rate>
(Extraction of free silicone oil)
1. Place 0.5 g of silica fine particles and 40 ml of chloroform in a beaker and stir for 2 hours.
2. Stop stirring and let stand for 12 hours.
3. The sample is filtered and washed 3 times with 40 ml of chloroform.

(Measurement of carbon content)
The sample is burned at 1100 ° C. under an oxygen stream, the amount of generated CO and CO ₂ is measured by IR absorbance, and the amount of carbon in the sample is measured. The carbon amount before and after extraction of the silicone oil is compared to calculate the immobilization rate based on the carbon amount of the silicone oil.
1. 2 g of sample is put into a cylindrical mold and pressed.
2. 0.15 g of the pressed sample is precisely weighed, placed on a combustion board, and measured with HORIBA, Ltd. EMA-11.
3.100- (carbon amount before extraction-carbon amount after extraction) / carbon amount before extraction × 100
Is the immobilization rate based on the carbon content of silicone oil.

  In addition, when the hydrophobic process is also performed with the silane compound etc., the immobilization rate after the process only of silicone oil is calculated, and the immobilization rate derived from silicone oil is calculated.

  The silica raw material used to obtain the silica fine particles of the present invention is produced from a dry process produced by vapor phase oxidation of a silicon halogen compound or dry silica called fumed silica, and water glass. Both wet silicas are mentioned. In the present invention, dry silica having less silanol groups on the surface and inside and no production residue is preferred.

  The silica fine particles used in the present invention are highly hydrophobic hydrophobized silica fine particles. Examples of the hydrophobizing treatment include a method of treating with an organosilicon compound that is chemically or physically adsorbed with a silica base. In order to obtain the effects of the present invention, at least treatment with silicone oil is required.

The silica fine particles of the present invention preferably have a BET specific surface area of the silica raw material before treatment of 50 m ² / g or more and 400 m ² / g or less for uniform silicone oil treatment.

  As a method for treating the silicone oil necessary for obtaining the silica fine particles of the present invention, the silica raw material and the silicone oil may be directly mixed using a mixer such as a Henschel mixer. Alternatively, a method may be used in which silicone oil is sprayed onto the silica base, or after dissolving or dispersing silicone oil in a suitable solvent, the silica base is mixed and the solvent is removed.

As the silicone oil, dimethyl silicone oil, methylphenyl silicone oil, and methyl hydrogen silicone oil can be used. In particular, dimethyl silicone oil is preferable, and the viscosity of the oil is preferably 300 mm ² / s or less at 25 ° C.

  The silica fine particles used in the present invention are treated with a silicone oil of 5.0 to 30.0 parts by mass, preferably 10.0 to 28.0 parts by mass with respect to 100 parts by mass of the silica raw material. It is preferable.

  When the silicone oil is chemically bonded to the surface of the silica base, the immobilization rate based on the carbon amount of the silicone oil increases. Therefore, as the amount of silicone oil to be added increases, the amount that cannot be chemically bonded to the surface of the silica base increases, so when the amount of silicone oil treated exceeds 30.0 parts by mass, the amount of free silicone oil increases too much, and the present invention. It becomes difficult to obtain the effect. When the processing amount of the silicone oil is less than 5.0 parts by mass, the hydrophobicity under high temperature and high humidity becomes insufficient and the developability tends to be lowered.

  A known technique is used for the surface treatment method of the silica base with silicone oil. In this treatment, in order to achieve the optimum immobilization ratio of the silicone oil to the silica base, the silica base is treated with heating. Is preferred. The treatment temperature is preferably in the range of 150 ° C. or higher and 350 ° C. or lower, more preferably 150 ° C. or higher and 250 ° C. or lower. By setting the temperature within this treatment temperature range, it is easy to increase the immobilization rate of the silicone oil to the surface of the silica base material while retaining an oil component that is partly free.

  In the present invention, an excellent effect is obtained when the content of the silica fine particles having the silicone oil immobilization ratio is 0.01 parts by mass or more and 3.00 parts by mass or less with respect to 100 parts by mass of the toner particles. When the amount exceeds 3.00 parts by mass, the ratio of the silica fine particles on the surface of the toner particles is excessively large, and the silica fine particles themselves are liberated, which easily leads to image defects such as white spots.

  The silica fine particles of the present invention are preferably surface treated with a silicone oil and then surface treated with a silane compound and / or a silazane compound from the viewpoint of obtaining appropriate charging characteristics. In particular, in order to cope with various kinds of transfer materials, it is necessary to have a certain charging characteristic. Surface treatment with a silane compound and / or a silazane compound is more preferable because the chargeability is improved and the transferability is improved as compared with the case of silicone oil alone.

  Examples of the silane compound used in the present invention include alkoxysilanes such as methoxysilane, ethoxysilane, and propoxysilane, halosilanes such as chlorosilane, bromosilane, and iodosilane, hydrosilanes, alkylsilanes, arylsilanes, vinylsilanes, and acrylics. Examples thereof include silanes, epoxy silanes, silyl compounds, siloxanes, silylureas, silylacetamides, and silane compounds having different substituents of these silane compounds at the same time. By using these silane compounds, fluidity, transferability and charge stabilization can be obtained. A plurality of these silane compounds may be used.

  Specific examples include trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyl. Trichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilyl mercaptan, trimethylsilyl mercaptan, triorganosilyl acrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, hexamethyldi Siloxane, 1,3-divinyltetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane And dimethylpolysiloxane containing 2 to 12 siloxane units per molecule and containing a hydroxyl group bonded to one Si at each terminal unit. You may use these as a 1 type, or 2 or more types of mixture.

  The silazane compound used in the present invention is a general term for compounds having a Si—N bond in the molecule. Specifically, dimethyldisilazane, trimethyldisilazane, tetramethyldisilazane, pentamethyldisilazane, hexamethyldisilazane, octamethyltrisilazane, hexamethylcyclotrisilazane, tetraethyltetramethylcyclotetrasilazane, tetraphenyldimethyldi Examples include silazane, dipropyltetramethyldisilazane, dibutyltetramethyldisilazane, dihexyltetramethyldisilazane, dioctyltetramethyldisilazane, diphenyltetramethyldisilazane, octamethylcyclotetrasilazane, and the like. Moreover, you may use the organic fluorine-containing silazane compound etc. which substituted these silazane compounds partially with the fluorine etc. Particularly in the present invention, hexamethyldisilazane is preferably used.

  In addition, when the silica fine particles of the present invention are applied to a positively chargeable toner, the following treatment agent is used.

  Examples of the silicone oil include silicone oil having a nitrogen atom in the side chain. As such a silicone oil, there is a silicone oil having a unit represented by the following formula (1) and / or (2).

［式中、Ｒ₁は水素原子，アルキル基，アリール基またはアルコキシ基を示し、Ｒ₂はアルキレン基またはフェニレン基を示し、Ｒ₃及びＲ₄は水素原子，アルキル基またはアリール基を示し、Ｒ₅は含窒素複素環基を示す。］

[Wherein R ₁ represents a hydrogen atom, an alkyl group, an aryl group or an alkoxy group, R ₂ represents an alkylene group or a phenylene group, R ₃ and R ₄ represent a hydrogen atom, an alkyl group or an aryl group; ₅ represents a nitrogen-containing heterocyclic group. ]

  Note that the alkyl group, aryl group, alkylene group, and phenylene group may have an organo group having a nitrogen atom, or may have a substituent such as a halogen atom.

  Examples of the silane compound include nitrogen-containing silane compounds.

  Specifically, aminopropyltrimethoxysilane, aminopropyltriethoxysilane, dimethylaminopropyltrimethoxysilane, diethylaminopropyltrimethoxysilane, dipropylaminopropyltrimethoxysilane, dibutylaminopropyltrimethoxysilane, monobutylaminopropyltri Methoxysilane, dioctylaminopropyltrimethoxysilane, dibutylaminopropyldimethoxysilane, dibutylaminopropylmonomethoxysilane, dimethylaminophenyltrimethoxysilane, trimethoxysilyl-γ-propylphenylamine, trimethoxysilyl-γ-propylbenzylamine, Trimethoxysilyl-γ-propylpiperidine, trimethoxysilyl-γ-propylmorpholine, trimethoxysilyl-γ- There are propylimidazole and the like. These treatment agents are used singly or as a mixture of two or more kinds or in combination or in multiple treatments.

  A well-known technique is used for the method of processing with a silane compound and / or a silazane compound. For example, silica particles treated with silicone oil are put into a treatment tank, and a predetermined amount of silane compound and / or silazane compound is dropped or sprayed while stirring inside the treatment tank with a stirring member such as a stirring blade. To mix. At this time, the silane compound and / or silazane compound can be diluted with a solvent such as alcohol. The silica fine particles containing the mixed and dispersed treatment agent are heated to a treatment temperature of 150 ° C. or higher and 350 ° C. or lower (preferably 150 ° C. or higher and 250 ° C. or lower) in a nitrogen atmosphere and refluxed for 0.5 to 5 hours with stirring.

  As a preferred production method, silica fine particles treated with silicone oil are put into a treatment tank, and the treatment tank is held at a temperature not lower than the boiling point of the silane compound and / or silazane compound to be treated and not higher than the decomposition temperature. Water vapor is blown here so that the hydroxyl groups on the surface of the silica fine particles are easily reacted with the silane compound or silazane compound. Further, it is preferable to add a silane compound and / or a silazane compound and treat the surface of the silica fine particles by a gas phase reaction. Thereafter, it is also possible to remove surplus materials such as surplus treatment agents as necessary.

  In addition, it is preferable to perform the crushing treatment before treating the silane compound and / or the silazane compound, in order to perform a uniform treatment.

  The preferable processing amount of these alkoxysilanes or silazanes is 2.0 to 30.0 parts by mass with respect to 100 parts by mass of the silica base.

Thus, it is preferable that the wettability of the treated silica fine particles with respect to the methanol and water mixed solvent satisfies the following formula (2).
D70−D90 ≦ 5.0 (2)

  That is, the difference when the methanol concentration when the transmittance of light having a wavelength of 780 nm is 90% is D90% by volume and the methanol concentration when the transmittance is 70% is D70% by volume is 5.0% by volume or less. It is characterized by being.

  This is an index representing the uniformity of the treatment agent with respect to the silica raw material, and contributes to the stabilization of charging of the toner. In other words, by setting this value to 5.0% by volume or less, more stable charging characteristics can be obtained, and density fluctuations associated with environmental fluctuations and durability can be suppressed. As a result, good images can be maintained for a long period of time. Become.

  In the present invention, the wettability of the silica fine particles is determined from a methanol dropping transmittance curve obtained as follows.

<Measurement of wettability of silica fine particles>
70 ml of water-containing methanol solution consisting of 60% by volume of methanol and 40% by volume of water is placed in a cylindrical glass container having a diameter of 5 cm and a thickness of 1.75 mm, and ultrasonic waves are used to remove bubbles in the measurement sample. Disperse for 5 minutes in a disperser.

  Next, 0.1 g of silica fine particles are precisely weighed and added to the container containing the above-mentioned hydrated methanol solution to prepare a measurement sample solution.

  Then, the measurement sample liquid is set in a powder wettability tester WET-100P (manufactured by Reska). The sample liquid for measurement is stirred at a speed of 6.7 s-1 (400 rpm) using a magnetic stirrer. As the rotor of the magnetic stirrer, a spindle type rotor having a length of 25 mm and a maximum barrel diameter of 8 mm coated with a fluororesin is used. Next, the transmittance was measured with light having a wavelength of 780 nm while continuously adding methanol to the measurement sample solution at a dropping rate of 1.3 ml / min through the above-described apparatus, as shown in FIG. Create a methanol drop transmission curve.

The BET specific surface area of the silica fine particles used in the present invention is preferably 100 m ² / g or more and 400 m ² / g or less. When the BET specific surface area of the silica fine particles is larger than 400 m ² / g, the adhesion force between the silica fine particles becomes too large and tends to aggregate, so that it is difficult to uniformly disperse the toner particle surfaces. On the other hand, when the BET specific surface area of the silica fine particles is smaller than 100 m ² / g, the chargeability and fluidity of the toner may be lowered.

  In addition, it is preferable to design the degree of liberation of the external additive from the toner particles as follows in order to obtain the effects of the present invention.

  External additive particles containing silica fine particles present on the toner particle surface tend to be easily released at places where a certain amount of pressure is applied, such as a mechanical share such as stirring in the developing device or a transfer nip portion of a transfer conveyance belt. There is.

  However, in order to maximize the effects of the present invention, it is preferable that the external additive is released from the toner particles as little as possible and only the silicone oil component is released from the silica fine particles only at the time of transfer.

  For that purpose, the external addition process at the time of toner production becomes very important. In other words, it is necessary to make the external additive particles containing silica fine particles as uniform as possible to the toner particles and to adhere with the optimum physical adsorption force. For example, in a conventional mixer such as a Henschel mixer, it is possible to obtain a uniform and optimum adhesive force by mixing and mixing multiple times, such as external addition at low speed and then external addition at high speed. Therefore, it is preferable.

  The degree of liberation of the external additive of the toner thus prepared is measured by the following method.

<Measurement of external additive liberation>
[Sample preparation]
1) Put 50 ml of electrolytic solution in a glass 200 ml beaker. Contaminone N (Nonionic surfactant, anionic surfactant, 10% by weight aqueous solution of neutral detergent for pH measuring precision cleaning instrument consisting of organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) About 0.3 ml of a diluted solution diluted about 3 times by mass with ion-exchanged water is added.
2) Two oscillators with an oscillation frequency of 50 kHz are incorporated with the phase shifted by 180 degrees, and an ultrasonic disperser Ultrasonic Dissipation System Tetora 150 (manufactured by Nikkaki Bios Co., Ltd.) having an electrical output of 120 W is prepared. About 3.3 l of ion-exchanged water is placed in the water tank of the ultrasonic disperser, and about 2 ml of Contaminone N is added to the water tank.
3) The beaker of 1) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. And the height position of a beaker is adjusted so that the resonance state of the liquid level of the electrolyte solution in a beaker may become the maximum.
4) In a state where the electrolytic aqueous solution in the beaker of 3) is irradiated with ultrasonic waves, 0.2 g of toner particles are added to the electrolytic aqueous solution and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. In the ultrasonic dispersion, the temperature of the water tank is appropriately adjusted so as to be 10 ° C. or higher and 40 ° C. or lower.
5) After 60 seconds, the beaker is taken out and immediately placed on a magnet (for example, neodymium magnet 30φ × 15 mm manufactured by ASONE). After 30 seconds, 10 ml is collected from the supernatant with a micropipette.

(Measurement of external additive liberation)
The degree of liberation of external additives can be measured using, for example, a Shimadzu spectrophotometer UV3100PC (manufactured by Shimadzu Corporation) and a quartz cell having an optical path length of 1 cm.

  The obtained supernatant solution is put in a quartz cell having an optical path length of 1 cm and quickly set in an apparatus, and the transmittance T of the supernatant solution at a wavelength of 500 nm of incident light is measured. At this time, an electrolytic aqueous solution in which the toner is not dissolved is put in the control cell.

  The transmittance T is defined as the degree of liberation of the external additive. The larger the value, the smaller the amount of free components and the less the external additive is released from the toner particles.

  The transmittance by UV measurement is 55.0% or more, preferably 70.0% or more, more preferably 80.0% or more. A transmittance of 55.0% or more indicates that the external additive adheres to the toner particles with an optimum strength, and the effects of the present invention can be more easily obtained.

  On the other hand, when the degree of liberation of the external additive is less than 55.0%, it indicates that the external additive is easily liberated from the toner particles due to a mechanical share such as stirring in the developing device. In particular, when the treatment of the silica fine particles is uneven or when the silicone oil is too liberated, the physical adhesion is weakened and the silica fine particles themselves are likely to be liberated. As a result, it becomes a free external additive when endured for a long period of time, particularly in an environment where the fluidity is lowered, such as a high temperature and high humidity environment, and may lead to image defects such as white spots caused by the free external additive. .

  The photoconductor used in the present invention uses a photoconductor provided with a photoconductive layer containing amorphous silicon and a surface protective layer containing amorphous silicon and / or amorphous carbon and / or amorphous silicon nitride on a conductive substrate. Is preferred.

  Amorphous silicon photoconductors have higher surface hardness and excellent polishing resistance than, for example, organic photoconductors. In addition, since it has a property excellent in environmental characteristics, that is, moisture resistance, it is excellent in long life, stability in long-term use, and high reliability, and is suitably used in light printing applications.

  However, since amorphous silicon photoconductors have extremely high surface hardness and high smoothness, the toner compacted at the transfer nip portion adheres to the surface of the photoconductor when the transfer conveyance belt is pressed against and transferred. It tends to be easy.

  Therefore, excellent transfer performance can be obtained by using in combination with the toner containing silica fine particles used in the present invention.

  Further, in the present invention, when the amorphous silicon photoconductor is provided with a surface protective layer containing amorphous carbon or amorphous silicon nitride, the environmental resistance characteristics are improved and the releasing effect from the toner is improved. The effect of preventing voids appears more effectively.

  Section of an example of a photoreceptor used in the present invention, comprising a conductive substrate, a photoconductive layer containing amorphous silicon and a surface protective layer containing amorphous silicon and / or amorphous carbon and / or amorphous silicon nitride on the substrate. The figure is shown in FIG.

  As the conductive substrate 21 shown in FIG. 3, for example, aluminum (Al) is the most common. Also, chromium (Cr), molybdenum (Mo), gold (Au), indium (In), niobium (Nb), tellurium (Te), vanadium (V), titanium (Ti), platinum (Pt), lead (Pd ), Metals such as iron (Fe), and alloys thereof, for example, stainless steel.

  In addition, a transparent substrate such as glass or plastic, or an insulator such as ceramic is also made into a conductive substrate by conducting a conductive treatment on its surface, that is, the surface on the side where the photoconductive layer 23 is formed. Can do.

  Further, in the present invention, an amorphous silicon-based and / or amorphous carbon-based and / or amorphous silicon nitride-based surface protective layer 23 is provided on the photoconductive layer 22.

  The photoconductive layer 22 may be organic or inorganic as long as it has photoconductivity.

  As the inorganic photoconductive layer, for example, it is preferable to use mainly an amorphous material in which silicon atoms contain hydrogen atoms and / or halogen atoms (hereinafter abbreviated as a-Si (H, X)). Or inorganic materials, such as a-Se, can be combined suitably.

  Moreover, it is preferable that the photoconductive layer 22 contains an atom for controlling conductivity as required.

  The atoms that control conductivity may be uniformly distributed in the photoconductive layer 22 or may be unevenly distributed.

  Examples of the atoms that control conductivity include so-called impurities in the semiconductor field. Use atoms belonging to Group III of the periodic table giving p-type conductivity (hereinafter abbreviated as Group III atoms) or atoms belonging to Group V of the Periodic Table giving n-type conductivity (hereinafter abbreviated as Group V atoms). Can do.

  Specific examples of the group III atom include boron (B), aluminum (Al), gallium (Ga), indium (In), and thallium (Tl). In particular, boron (B), aluminum (Al), and gallium. (Ga) is preferred. Specific examples of the group V atom include phosphorus (P), arsenic (As), antimony (Sb), and bismuth (Bi), and phosphorus (P) and arsenic (As) are particularly preferable. By appropriately doping these impurities, the charging polarity of the amorphous photoreceptor can be determined.

  Further, in order to improve the photosensitive characteristics, the photoconductive layer 22 may have a plurality of layers such as a lower photoconductive layer 25 and an upper photoconductive layer 26. The film thickness of the photoconductive layer 22 is not particularly limited, but about 15 to 50 μm is appropriate from the viewpoint of manufacturing cost.

  The surface protective layer 23 is a non-single crystal (preferably amorphous) material (a-SiC (H, X)) containing a silicon atom as a base and containing a carbon atom and, if necessary, a hydrogen atom and / or a halogen atom. The base is a carbon atom.

  Further, a non-single crystal carbon containing a hydrogen atom and / or a halogen atom as necessary, a non-single crystal containing a silicon atom as a base and a nitrogen atom and optionally a hydrogen atom and / or a halogen atom (preferably Amorphous) material or the like. Moreover, it forms also by these combination.

  In the present invention, since the photoreceptor has such a surface protective layer, the contact property with the transfer / conveying belt is improved, and the releasing effect on the surface of the photoreceptor is improved. Are more likely to be expressed more efficiently.

  The film thickness of the surface protective layer 23 is not particularly limited, but about 0.05 to 2.00 μm is appropriate from the viewpoint that it is sufficient if it exists at the minimum necessary for actual use.

  In addition, it is preferable to provide an interface layer (or antireflection layer) 27 in which the interface composition between the photoconductive layer 22 and the surface protective layer 23 is continuously changed, and to control the interface reflection in this portion.

  In addition, the surface of the conductive substrate 21 is preferably formed into a concavo-convex groove or dimple shape by cutting or the like. By adopting such a surface shape, it is possible to make it difficult to see the interference fringes caused by the reflection of the exposure light that has reached the surface of the conductive substrate 21, and the substrate of the film formed on the conductive substrate 21. The adhesion with 21 is also improved.

  Further, the shape of the conductive substrate may be as desired according to the driving method of the photosensitive member.

  Of course, in addition to these layers, various functional layers such as the charge injection blocking layer 24 as shown may be provided as necessary.

  For example, by providing the charge injection blocking layer 24 and appropriately selecting the dopant from group III atoms, group V atoms, etc., charge polarity control such as positive charge or negative charge becomes possible.

  A simple method for preparing the toner particles used in the present invention will be described, but is not limited thereto.

  The toner particles of the present invention contain at least a binder resin and a colorant.

  Examples of the binder resin used in the toner of the present invention include the following. Vinyl resin, styrene resin, styrene copolymer resin, polyester resin, polyol resin, polyvinyl chloride resin, phenol resin, natural modified phenol resin, natural resin modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, Silicone resin, polyurethane resin, polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, terpene resin, coumarone indene resin, petroleum resin. Among these, vinyl resins and polyester resins are preferably used.

  Of these, polyester resins are preferred from the viewpoints of excellent fixability and high mechanical strength.

  The components of the polyester resin used in the present invention are as follows.

  The following are mentioned as a bivalent alcohol component. Ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol 2-ethyl-1,3-hexanediol, 1,4-cyclohexanedimethanol (CHDM), hydrogenated bisphenol A, bisphenol represented by formula (I) and derivatives thereof:

（式中、Ｒはエチレンまたはプロピレン基であり、ｘ、ｙはそれぞれ０以上の整数であり、かつ、ｘ＋ｙの平均値は０乃至１０である。）
および式（ＩＩ）で示されるジオール類。

(In the formula, R is an ethylene or propylene group, x and y are each an integer of 0 or more, and the average value of x + y is 0 to 10.)
And diols represented by formula (II).

  Examples of the divalent acid component include the following dicarboxylic acids or derivatives thereof. Benzene dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, phthalic anhydride or their anhydrides or lower alkyl esters thereof; alkyl dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, azelaic acid or their anhydrides or lower thereof Alkyl esters; alkenyl succinic acids or alkyl succinic acids such as n-dodecenyl succinic acid, n-dodecyl succinic acid, or anhydrides thereof or lower alkyl esters thereof; unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid, itaconic acid Or its anhydride or its lower alkyl ester. In particular, terephthalic acid and isophthalic acid are preferable.

  Moreover, it is preferable that the said polyester resin contains the polyester resin containing the crosslinked structure by the polyhydric carboxylic acid more than trivalence or its anhydride, and / or the trihydric or more polyhydric alcohol.

  Examples of the trivalent or higher polyvalent carboxylic acid or anhydride thereof include 1,2,4-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, and pyromellitic acid. And acid anhydrides or lower alkyl esters thereof.

  On the other hand, examples of the trihydric or higher polyhydric alcohol include 1,2,3-propanetriol, trimethylolpropane, hexanetriol, and pentaerythritol.

  Examples of the monomer used for the vinyl resin include the following known ones.

  For example, styrene; styrene derivatives such as o-methylstyrene and m-methylstyrene; α-methylene aliphatic monocarboxylic acid esters such as methyl methacrylate and ethyl methacrylate; methyl acrylate, ethyl acrylate, and acrylic acid n -Acrylic acid esters such as butyl.

  In the toner of the present invention, the vinyl resin used as the binder resin may have a crosslinked structure crosslinked with a crosslinking agent having two or more vinyl groups. Examples of the crosslinking agent used in this case include divinylbenzene and divinylnaphthalene. The addition amount of these crosslinking agents is preferably 0.001 part by mass or more and 10.000 parts by mass or less, and 0.002 part by mass or more and 1.000 parts by mass with respect to 100 parts by mass of the vinyl monomer component. The following is more preferable.

  As the polymerization initiator used for the polymerization of the vinyl polymer unit of the vinyl resin, the following known initiators are used. For example, 2,2′-azobisisobutyronitrile, 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), Etc.

  The binder resin may be used alone, but in the present invention, two types of resins having different viscosities, that is, a high viscosity resin and a low viscosity resin are mixed and used in the range from 90:10 to 10:90. It is preferable.

  This is because by using two or more kinds of resins having different melt viscosities, for example, when a toner is produced by melt kneading, the kneading load increases and the dispersibility of other raw materials is further improved.

  It is preferable that the binder resin has the following molecular weight distribution in the molecular weight distribution measured by gel permeation chromatography (GPC) soluble in tetrahydrofuran (THF).

  The high molecular weight resin used as the high viscosity resin preferably has a peak molecular weight (Mp) of 5,000 to 20,000, and a weight average molecular weight (Mw) of 100,000 to 900,000. Moreover, it is preferable that ratio (Mw / Mn) of a weight average molecular weight (Mw) and a number average molecular weight (Mn) is 10-45.

  The low molecular weight resin used as the low viscosity resin preferably has a peak molecular weight (Mp) of 2,000 to 10,000 and a weight average molecular weight (Mw) of 4,000 to 100,000. Moreover, it is preferable that ratio (Mw / Mn) of a weight average molecular weight (Mw) and a number average molecular weight (Mn) is 1-9.

  Furthermore, the glass transition temperature of the binder resin is preferably 53 ° C. or higher and 62 ° C. or lower from the viewpoint of fixability and storage stability.

  Further, from the viewpoint of imparting elasticity to the toner and further improving the material dispersibility, the THF-insoluble component in the high molecular weight resin is 3.0% by mass or more and 50.0% by mass or less, preferably 10.0% by mass or more and 40.% or less. It is preferable to contain 0% by mass or less.

  The toner using these resins has a peak molecular weight (Mp) of 4,000 or more and 12,000 or less, and a weight average molecular weight (Mw) of 50,000 or more and 1,000,000 or less. It is preferable from the viewpoint of offset resistance.

  Further, from the viewpoint of imparting elasticity to the toner and further improving the material dispersibility, the THF-insoluble component in the toner is 3.0% by mass or more and 40.0% by mass or less, preferably 10.0% by mass or more and 30.0%. It is preferable to contain it by mass% or less.

  In addition, the toner of the present invention may contain a release agent having a melting point defined by an endothermic peak temperature at the time of temperature increase by differential scanning calorimeter (DSC) measurement of 60 ° C. or more and 120 ° C. or less. The melting point of the release agent is preferably 70 to 115 ° C.

  The release agent is preferably added in an amount of 1 part by weight to 20 parts by weight with respect to 100 parts by weight of the binder resin. If the amount is less than 1 part by mass, the desired release effect cannot be sufficiently obtained. If the amount exceeds 20 parts by mass, the dispersion in the toner is poor, and the scattered toner adheres to the transfer / conveying belt, resulting in image defects. It becomes easy to cause.

  Examples of the release agent include aliphatic hydrocarbon waxes such as low molecular polyethylene, low molecular polypropylene, microcrystalline wax, and paraffin wax; oxides of aliphatic hydrocarbon waxes such as oxidized polyethylene wax; Block copolymer of hydrogen-based wax; waxes based on fatty acid esters such as carnauba wax, sazol wax and montanic acid ester wax; partially or fully deoxidized fatty acid esters such as deoxidized carnauba wax Things. In addition, saturated linear fatty acids such as palmitic acid, stearic acid, montanic acid, or long-chain alkyl carboxylic acids having a long-chain alkyl group; unsaturated fatty acids such as brassic acid, eleostearic acid, and valinal acid; Saturated alcohols such as stearic alcohol, aralkyl alcohol, behenyl alcohol, carnauvir alcohol, seryl alcohol, melyl alcohol, or long chain alkyl alcohols having a long chain alkyl group; polyhydric alcohols such as sorbitol: calcium stearate , Fatty acid metal salts such as calcium laurate, zinc stearate and magnesium stearate (generally called metal soap); vinyl monomers such as styrene and acrylic acid are used in aliphatic hydrocarbon waxes Grafted waxes; partially esterified products of fatty acids and polyhydric alcohols such as behenic monoglyceride; methyl ester compounds having hydroxyl groups obtained by hydrogenation of vegetable oils; long-chain alkyl alcohols having 12 or more carbon atoms or long Chain alkylcarboxylic acid; and the like.

  Examples of the release agent particularly preferably used in the present invention include aliphatic hydrocarbon waxes. As such an aliphatic hydrocarbon wax, for example, a low molecular weight alkylene polymer obtained by radical polymerization of alkylene under high pressure or a Ziegler catalyst under low pressure; Alkylene polymers obtained; synthetic hydrocarbon waxes obtained from the distillation residue of hydrocarbons obtained by the age method from synthesis gas containing carbon monoxide and hydrogen, and synthetic hydrocarbon waxes obtained by hydrogenating them; these aliphatics And hydrocarbon waxes separated by press sweating, solvent method, vacuum distillation and fractional crystallization.

  Examples of the hydrocarbon as the matrix of the aliphatic hydrocarbon wax include those synthesized by the reaction of carbon monoxide and hydrogen using a metal oxide catalyst (often a multi-component system of two or more types) (for example, Hydrocarbon compounds synthesized by the Gintor method and Hydrocol method (using a fluidized catalyst bed); Up to several hundred carbon atoms can be obtained by the Age method (using an identified catalyst bed) in which many waxy hydrocarbons are obtained Hydrocarbons; hydrocarbons obtained by polymerizing alkylene such as ethylene with a Ziegler catalyst. Among such hydrocarbons, in the present invention, it is preferable that the hydrocarbon is a linear hydrocarbon having a small number of branches and a long saturation, and particularly a hydrocarbon synthesized by a method not based on polymerization of alkylene has a molecular weight distribution. Is also preferable.

  Specific examples that can be used include Biscol (registered trademark) 330-P, 550-P, 660-P, TS-200 (Sanyo Chemical Industries), high wax 400P, 200P, 100P, 410P, 420P, 320P, 220P, 210P, 110P (Mitsui Chemicals), Sazol H1, H2, C80, C105, C77 (Sazol Wax), HNP-1, HNP-3, HNP-9, HNP-10, HNP-11, HNP- 12 (Nippon Seiwa Co., Ltd.), Unilin (registered trademark) 350, 425, 550, 700, Unicid (registered trademark), Unicid (registered trademark) 350, 425, 550, 700 (Toyo Petrolite Co., Ltd.) Beeswax, rice wax, candelilla wax, carnauba wax (available from Celerica NODA) And the like.

  The timing of adding the release agent may be added at the time of melt-kneading during toner production or may be at the time of binder resin production, and is appropriately selected from existing methods. These release agents may be used alone or in combination.

  The toner of the present invention may be a magnetic toner or a non-magnetic toner, but is preferably a magnetic toner from the viewpoint of durability and stability in a high speed machine.

Magnetic materials used in the present invention include magnetic iron oxides including iron oxides such as magnetite, maghemite and ferrite, and other metal oxides; metals such as Fe, Co and Ni, or these metals and Al, Examples thereof include alloys with metals such as Co, Pb, Mg, Ni, Sn, Zn, Sb, Be, Bf, Cd, Ca, Mn, Se, Ti, W, and V, and mixtures thereof. Conventionally, triiron tetroxide (Fe ₃ O ₄ ), iron sesquioxide (γ-Fe ₂ O ₃ ), zinc iron oxide (ZnFe ₂ O ₄ ), iron yttrium oxide (Y ₃ Fe ₅ O ₁₂ ), cadmium iron oxide (Cd ₃ Fe ₂ O ₄ ), iron gadolinium oxide (Gd ₃ Fe ₅ O ₁₂ ), iron oxide copper (CuFe ₂ O ₄ ), lead iron oxide (PbFe ₁₂ O ₁₉ ), nickel iron oxide (NiFe ₂ O ₄ ) , Iron oxide neodymium (NdFe ₂ O ₃ ), iron barium oxide (BaFe ₁₂ O ₁₉ ), iron oxide magnesium (MgFe ₂ O ₄ ), iron oxide manganese (MnFe ₂ O ₄ ), iron lanthanum oxide (LaFeO ₃ ), iron Powder (Fe), cobalt powder (Co), nickel powder (Ni), and the like are known. A particularly suitable magnetic material is a fine powder of iron tetroxide or γ-iron sesquioxide. Further, the above-described magnetic materials can be selected and used alone or in combination of two or more.

These magnetic materials have a magnetic property of 795.8 kA / m applied and a coercive force of 1.6 to 12.0 kA / m, and a saturation magnetization of 50.0 to 200.0 Am ² / kg (preferably 50.0 or more). 100.0 Am ² / kg or less). Further, the residual magnetization is preferably 2.0 or more and 20.0 Am ² / kg or less.

  The magnetic properties of the magnetic material can be measured using a vibration magnetometer such as VSM P-1-10 (manufactured by Toei Kogyo Co., Ltd.) under the conditions of 25 ° C. and an external magnetic field of 769 kA / m.

  The magnetic material is preferably added in an amount of 10 to 200 parts by mass with respect to 100 parts by mass of the binder resin.

  When used as a non-magnetic toner, carbon black and other conventionally known pigments and dyes, or one or more of them can be used as the colorant. The colorant is preferably 0.1 parts by mass or more and 60.0 parts by mass or less, and more preferably 0.5 or more and 50.0 parts by mass or less with respect to 100.0 parts by mass of the resin component.

  In the toner of the present invention, a charge control agent can be used to stabilize the chargeability.

  The charge control agent varies depending on the type and the physical properties of other toner particle constituent materials, but generally, the toner particles are contained in an amount of 0.1 to 10.0 parts by mass per 100 parts by mass of the binder resin. Is preferred.

  As such charge control agents, there are known ones for controlling the toner to be negatively charged and those for controlling the toner to be positively charged. One or two kinds of various kinds of charge control agents are used depending on the kind and use of the toner. The above can be used.

  For controlling the toner to be negatively charged, for example, an organometallic complex and a chelate compound are effective. Examples thereof include a monoazo metal complex; an acetylacetone metal complex; a metal complex of aromatic hydroxycarboxylic acid or aromatic dicarboxylic acid; A metal salt. In addition, examples of the toner that controls the toner to be negatively charged include aromatic mono- and polycarboxylic acids and metal salts and anhydrides thereof; phenol derivatives such as esters and bisphenol;

  Examples of toners that can be positively charged include, for example, modified products of nigrosine and fatty acid metal salts; quaternary ammoniums such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate and tetrabutylammonium tetrafluoroborate. Salts, and onium salts such as phosphonium salts and analogs thereof, and lake pigments thereof; triphenylmethane dyes and lake pigments thereof (including phosphotungstic acid, phosphomolybdic acid, phosphotungstic molybdic acid, Tannic acid, lauric acid, gallic acid, ferricyanic acid, ferrocyanic compound, etc.); metal salts of higher fatty acids and the like. In the present invention, these can be used alone or in combination. Among them, a charge control agent such as a nigrosine compound, a triphenylmethane lake pigment, a quaternary ammonium salt, etc. is particularly preferably used for controlling the toner to be positively charged.

  Specific examples that can be used include Spiron Black TRH, T-77, T-95, TN-105 (Hodogaya Chemical Co., Ltd.), BONTRON (registered trademark) S-34, S-44, E-84, E- 88 (Orient Chemical Co., Ltd.), and preferable examples for positive charging include TP-302, TP-415 (Hodogaya Chemical Co., Ltd.), BONTRON (registered trademark) N-01, N-04, N- 07, P-51 (Orient Chemical), and Copy Blue PR (Clariant).

  Moreover, charge control resins, such as a copolymer of a vinyl-type monomer and 2-acrylamido-2-methylpropanesulfonic acid, can be used, and it can also use together with the above-mentioned charge control agent.

  The chargeability of the toner of the present invention may be either positive or negative. However, since the polyester resin itself, which is a preferred binder resin, has high negative chargeability, it is preferably a negatively chargeable toner.

  In the toner of the present invention, inorganic fine powders other than silica fine particles can be used in combination for the purpose of imparting a polishing effect, chargeability and fluidity, and as a cleaning aid. The inorganic fine powder having such an abrasive effect is not particularly limited, since it can be added externally to the toner particles and exist on the surface of the toner particles, whereby the effect can be further increased as compared with before and after the addition. Examples of the inorganic fine powder having a polishing effect used in the present invention include titanates and / or silicates such as magnesium, zinc, cobalt, manganese, strontium, cerium, calcium, and barium.

In particular, strontium titanate (SrTiO ₃ ), calcium titanate (CaTiO ₃ ), strontium silicate (SrSiO ₃ ), and barium titanate (BaTiO ₃ ) are preferable.

  The inorganic fine powder used in the present invention is preferably produced by, for example, a sintering method, mechanically pulverized, and then subjected to air classification and having a desired particle size distribution.

  In the present invention, the inorganic fine powder having a polishing effect is used in an amount of 0.1 to 10.0 parts by weight, preferably 0.2 to 8.0 parts by weight, based on 100 parts by weight of the toner. Is good.

  The toner particles and toner of the present invention preferably have a weight average particle size of 3.0 or more and 9.0 μm or less from the viewpoint of image density and resolution.

  A method for measuring physical properties of the resin and toner of the present invention is as follows. Examples described later are also based on this method.

(1) Measurement of molecular weight distribution by GPC A column is stabilized in a heat chamber at 40 ° C., THF is flowed through the column at this temperature as a solvent at a flow rate of 1 ml per minute, and about 100 μl of a THF sample solution is injected and measured. .

In measuring the molecular weight of the sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithmic value and the count value of a calibration curve prepared from several types of monodisperse polystyrene standard samples. As a standard polystyrene sample for preparing a calibration curve, for example, about 10 ² to 10 ⁷ are used, and it is appropriate to use at least about 10 standard polystyrene samples.

  For example, TSK standard polystyrene manufactured by Tosoh Corporation (F-850, F-450, F-288, F-128, F-80, F-40, F-20, F-10, F-4, F-2, F -1, A-5000, A-2500, A-1000, A-500) can be used.

  The detector uses an RI (refractive index) detector. As a column, it is preferable to combine a plurality of commercially available polystyrene gel columns.

For example, combination or manufactured by Showa Denko KK of shodex GPC KF-801,802,803,804,805,806,807,800P, manufactured by Tosoh Corporation of _{TSKgel G1000H (H XL), G2000H} (H XL), G3000H (H XL ), G4000H (H _XL ), G5000H (H _XL ), G6000H (H _XL ), G7000H (H _XL ), and TSKgourd column.

  Moreover, a sample is produced as follows.

  0.2 g of toner or 0.1 g of resin is placed in 20 ml of THF and allowed to stand at 25 ° C. for 24 hours. Then, a sample processing filter (pore size of about 0.5 μm, for example, Mysori Disc H-25-2 (manufactured by Tosoh Corporation)) can be used as a GPC sample.

(2) Measurement of glass transition temperature of binder resin The glass transition temperature of the binder resin is measured according to ASTM D3418-82 using a differential scanning calorimeter analyzer Q1000 (manufactured by TA Instruments).

  The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of heat uses the heat of fusion of indium. Specifically, about 5 mg of the binder resin is precisely weighed and placed in an aluminum pan, and an empty aluminum pan is used as a reference, and the heating rate is 10 ° C. between a measurement range of 30 to 200 ° C. Measure at / min. In this temperature rising process, a specific heat change is obtained in the temperature range of 40 to 100 ° C. At this time, the intersection of the intermediate point line of the base line before and after the change in specific heat and the differential heat curve is defined as the glass transition temperature Tg of the binder resin.

(3) Measurement of melting point of wax The melting point of wax is measured according to ASTM D3418-82 using a differential scanning calorimeter analyzer Q1000 (manufactured by TA Instruments).

  The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of heat uses the heat of fusion of indium.

  Specifically, about 3 mg of wax is precisely weighed, placed in an aluminum pan, and an empty aluminum pan is used as a reference. Measurement is performed at ° C / min. In the measurement, the temperature is once raised to 200 ° C., subsequently lowered to 30 ° C., and then the temperature is raised again. The maximum endothermic peak of the DSC curve in the temperature range of 30 to 200 ° C. in the second temperature raising process is defined as the melting point of the wax.

(4) Measurement of THF-insoluble matter About 1.0 g of resin and toner are weighed (W1 g), placed in a cylindrical filter paper (for example, No. 86R size 28 × 100 mm, manufactured by Advantech Toyo Co., Ltd.), passed through a Soxhlet extractor, and 200 ml of THF as a solvent. And extract for 16 hours. At this time, extraction is performed at a reflux rate such that the solvent extraction cycle is about once every 4 minutes. After the extraction is completed, the cylindrical filter paper is taken out and vacuum-dried at 40 ° C. for 8 hours, and the extraction residue is weighed (W2 g).

  In the case of toner, the weight of incinerated residual ash in the toner (W3 g) is obtained by the following procedure.

About 2 g of a sample is placed in a 30 ml magnetic crucible that has been precisely weighed in advance, and weighed accurately, and the mass (Wag) of the sample is precisely weighed. The crucible is put in an electric furnace, heated at about 900 ° C. for about 3 hours, allowed to cool in the electric furnace, and allowed to cool in a desiccator for 1 hour or more at room temperature, and the mass of the crucible is precisely weighed. The incineration residual ash content (Wbg) is obtained from here.
(Wb / Wa) × 100 = Incineration residual ash content (mass%)

  The mass (W3g) of the incinerated residual ash content of the sample is determined from this content rate.

The THF-insoluble content of the toner can be obtained from the following formula.
Toner THF insoluble content = [W2-W3] / [W1-W3] × 100%

Further, the measurement of the THF-insoluble content of the binder resin is obtained from the following formula.
THF insoluble matter = W2 / W1 × 100 (%)

(5) Measuring method of weight average particle diameter (D4) The toner particles and the weight average particle diameter (D4) of the toner are calculated as follows. As a measuring device, a precise particle size distribution measuring device “Coulter Counter Multisizer 3” (registered trademark, manufactured by Beckman Coulter, Inc.) using a pore electrical resistance method equipped with a 100 μm aperture tube is used.

  For setting the measurement conditions and analyzing the measurement data, the attached dedicated software “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.) is used. Note that the measurement is performed with 25,000 effective measurement channels.

  As the electrolytic aqueous solution used for the measurement, special grade sodium chloride is dissolved in ion-exchanged water so as to have a concentration of about 1% by mass, for example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) can be used.

  Prior to measurement and analysis, the dedicated software was set as follows.

  On the “Change Standard Measurement Method (SOM)” screen of the dedicated software, set the total count in the control mode to 50,000 particles, set the number of measurements once, and set the Kd value to “standard particles 10.0 μm” (Beckman Coulter Set the value obtained using By pressing the “Threshold / Noise Level Measurement Button”, the threshold and noise level are automatically set. In addition, the current is set to 1600 μA, the gain is set to 2, the electrolyte is set to ISOTON II, and the “aperture tube flush after measurement” is checked.

  In the “Pulse to particle size conversion setting” screen of the dedicated software, the bin interval is set to logarithmic particle size, the particle size bin is set to 256 particle size bin, and the particle size range is set to 2 μm to 60 μm.

The specific measurement method is as follows.
1) About 200 ml of the electrolytic solution is placed in a 250 ml round bottom beaker made exclusively for Multisizer 3, set on a sample stand, and the stirrer rod is stirred counterclockwise at 24 rpm. Then, the dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the dedicated software.
2) About 30 ml of the electrolytic aqueous solution is put into a glass 100 ml flat bottom beaker. In this, "Contaminone N" (nonionic surfactant, anionic surfactant, 10% by weight aqueous solution of neutral detergent for pH7 precision measuring instrument cleaning, made by organic builder, manufactured by Wako Pure Chemical Industries, Ltd. About 0.3 ml of a diluted solution obtained by diluting 3) with ion-exchanged water is added.
3) Two oscillators with an oscillation frequency of 50 kHz are incorporated with the phase shifted by 180 degrees, and an ultrasonic disperser “Ultrasonic Dissipation System Tetora 150” (manufactured by Nikki Bios Co., Ltd.) having an electrical output of 120 W is prepared. About 3.3 l of ion-exchanged water is placed in the water tank of the ultrasonic disperser, and about 2 ml of Contaminone N is added to the water tank.
4) The beaker of 2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. And the height position of a beaker is adjusted so that the resonance state of the liquid level of the electrolyte solution in a beaker may become the maximum.
5) In the state where the electrolytic aqueous solution in the beaker of 4) is irradiated with ultrasonic waves, toner particles or about 10 mg of toner is added to the electrolytic aqueous solution little by little and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. In the ultrasonic dispersion, the temperature of the water tank is appropriately adjusted so as to be 10 ° C. or higher and 40 ° C. or lower.
6) The above 1. installed in the sample stand. The toner particles or the toner is dispersed in a round bottom beaker using a pipette. The aqueous electrolyte solution is dropped to adjust the measured concentration to about 5%. The measurement is performed until the number of measured particles reaches 50,000.
7) The measurement data is analyzed with the dedicated software attached to the apparatus, and the weight average particle diameter (D4) is calculated. The “average diameter” on the “analysis / volume statistics (arithmetic average)” screen when the graph / volume% is set by the dedicated software is the weight average particle diameter (D4).

(6) Measurement of BET specific surface area of silica fine particles and silica raw material The BET specific surface area of silica fine particles is measured according to JIS Z8830 (2001). A specific measurement method is as follows.

  As a measuring device, an “automatic specific surface area / pore distribution measuring device TriStar 3000 (manufactured by Shimadzu Corporation)” which employs a gas adsorption method by a constant volume method as a measuring method is used. Setting of measurement conditions and analysis of measurement data are performed using dedicated software “TriStar3000 Version 4.00” attached to the apparatus, and a vacuum pump, a nitrogen gas pipe, and a helium gas pipe are connected to the apparatus. The value calculated by the BET multipoint method using nitrogen gas as the adsorption gas is defined as the BET specific surface area in the present invention.

  The BET specific surface area is calculated as follows.

First, nitrogen gas is adsorbed on silica fine particles, and then the equilibrium pressure P (Pa) in the sample cell and the nitrogen adsorption amount Va (mol / g) of the silica fine particles are measured. The relative pressure Pr, which is a value obtained by dividing the equilibrium pressure P (Pa) in the sample cell by the saturated vapor pressure Po (Pa) of nitrogen, is plotted on the horizontal axis, and the nitrogen adsorption amount Va (mol / g) is plotted on the vertical axis. An adsorption isotherm is obtained. Next, a monomolecular layer adsorption amount Vm (mol / g), which is an adsorption amount necessary for forming a monomolecular layer on the surface of the silica fine particles, is obtained by applying the following BET equation.
Pr / Va (1-Pr) = 1 / (Vm * C) + (C-1) * Pr / (Vm * C)
(Here, C is a BET parameter, which is a variable that varies depending on the measurement sample type, adsorbed gas type, and adsorption temperature.)

The BET equation is interpreted as a straight line with an inclination of (C-1) / (Vm × C) and an intercept of 1 / (Vm × C), where Pr is X axis and Pr / Va (1-Pr) is Y axis. Yes (this line is called a BET plot).
Straight line slope = (C-1) / (Vm × C)
Straight line intercept = 1 / (Vm × C)

  When the measured value of Pr and the measured value of Pr / Va (1-Pr) are plotted on a graph and a straight line is drawn by the least square method, the slope and intercept value of the straight line can be calculated. Vm and C can be calculated by solving the above slope and intercept simultaneous equations using these values.

Further, the BET specific surface area S (m ² / g) of the silica fine particles is calculated from the calculated Vm and the molecular occupation cross-sectional area (0.162 nm ² ) of the nitrogen molecule based on the following formula.
S = Vm × N × 0.162 × 10 ⁻¹⁸
(N is Avogadro's number (mole- ¹ ).)

  The measurement using this apparatus follows the “TriStar 3000 Instruction Manual V4.0” attached to the apparatus, and specifically, the measurement is performed according to the following procedure.

  Thoroughly weigh the tare of a dedicated glass sample cell (stem diameter 3/8 inch, volume about 5 ml) that has been thoroughly cleaned and dried. Then, about 0.1 g of silica fine particles are put into the sample cell using a funnel.

  The sample cell containing the silica fine particles is set in a “pretreatment device Bacrepprep 061 (manufactured by Shimadzu Corporation)” connected with a vacuum pump and a nitrogen gas pipe, and vacuum degassing is continued at 23 ° C. for about 10 hours. In vacuum degassing, the gas is gradually degassed while adjusting the valve so that silica fine particles are not sucked into the vacuum pump. The pressure in the cell gradually decreases with deaeration and finally becomes about 0.4 Pa (about 3 mTorr). After completion of vacuum degassing, nitrogen gas is gradually injected to return the inside of the sample cell to atmospheric pressure, and the sample cell is removed from the pretreatment device. Then, the mass of the sample cell is precisely weighed, and the accurate mass of the silica fine particles is calculated from the difference from the tare. At this time, the sample cell is covered with a rubber plug during weighing so that the silica fine particles in the sample cell are not contaminated by moisture in the atmosphere.

  Next, a dedicated “isothermal jacket” is attached to the stem portion of the sample cell containing the silica fine particles. Then, a dedicated filler rod is inserted into the sample cell, and the sample cell is set in the analysis port of the apparatus. The isothermal jacket is a cylindrical member having an inner surface made of a porous material and an outer surface made of an impermeable material capable of sucking liquid nitrogen to a certain level by capillary action.

  Subsequently, the free space of the sample cell including the connection tool is measured. Free space is measured by measuring the volume of the sample cell with helium gas at 23 ° C., and then measuring the volume of the sample cell after cooling the sample cell with liquid nitrogen in the same manner using helium gas. Calculated from the difference in volume. Further, the saturated vapor pressure Po (Pa) of nitrogen is automatically measured separately using a Po tube built in the apparatus.

  Next, after performing vacuum deaeration in the sample cell, the sample cell is cooled with liquid nitrogen while continuing the vacuum deaeration. Thereafter, nitrogen gas is gradually introduced into the sample cell to adsorb nitrogen molecules on the silica fine particles. At this time, the adsorption isotherm is obtained by measuring the equilibrium pressure P (Pa) as needed, and the adsorption isotherm is converted into a BET plot. Note that the points of the relative pressure Pr for collecting data are set to a total of 6 points of 0.05, 0.10, 0.15, 0.20, 0.25, and 0.30. A straight line is drawn from the obtained measurement data by the least square method, and Vm is calculated from the slope and intercept of the straight line. Furthermore, using the value of Vm, the BET specific surface area of the silica fine particles is calculated as described above.

(8) Measurement of volume-based median diameter (D50) of strontium titanate Measured according to JIS Z8825-2 (2001), specifically, as follows.

  As a measuring device, a laser diffraction / scattering particle size distribution measuring device “LA-920” (manufactured by Horiba, Ltd.) is used. The dedicated software “HORIBA LA-920 for Windows (registered trademark) WET (LA-920) Ver. 2.02” attached to LA-920 is used for setting measurement conditions and analyzing measurement data. As the measurement solvent, ion-exchanged water from which impure solids are removed in advance is used.

The measurement procedure is as follows.
1) Attach the batch type cell holder to LA-920.
2) Put a predetermined amount of ion-exchanged water in a batch cell and set the batch cell in a batch cell holder.
3) Stir the inside of the batch cell using a dedicated stirrer tip.
4) Press the “refractive index” button on the “display condition setting” screen and select the file “110A000I” (relative refractive index 1.10).
5) In the “display condition setting” screen, the particle diameter standard is set as the volume standard.
6) After performing warm-up operation for 1 hour or more, the optical axis is adjusted, the optical axis is finely adjusted, and blank measurement is performed.
7) Put about 60 ml of ion-exchanged water in a glass 100 ml flat bottom beaker. Among them, as a dispersant, “Contaminone N” (a nonionic surfactant, an anionic surfactant, a 10% by weight aqueous solution of a neutral detergent for washing a pH 7 precision measuring instrument comprising an organic builder, Wako Pure Chemical Industries, Ltd. About 0.3 ml of a diluted solution obtained by diluting the product (manufactured) with ion exchange water about 3 times by mass is added.
8) Two oscillators with an oscillation frequency of 50 kHz are incorporated with the phase shifted by 180 degrees, and an ultrasonic disperser “Ultrasonic Dissipation System Tetora 150” (manufactured by Nikki Bios Co., Ltd.) having an electrical output of 120 W is prepared. About 3.3 l of ion-exchanged water is placed in the water tank of the ultrasonic disperser, and about 2 ml of Contaminone N is added to the water tank.
9) The beaker of 7) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. And the height position of a beaker is adjusted so that the resonance state of the liquid level of the aqueous solution in a beaker may become the maximum.
10) In a state where the aqueous solution in the beaker of 9) is irradiated with ultrasonic waves, about 1 mg of strontium titanate is added to the aqueous solution in the beaker little by little and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. In this case, strontium titanate may solidify and float on the liquid surface. In this case, ultrasonic dispersion is performed for 60 seconds after the solid is submerged by shaking the beaker. Moreover, in ultrasonic dispersion, it adjusts suitably so that the water temperature of a water tank may become 10 to 40 degreeC.
11) The aqueous solution in which strontium titanate prepared in 10) is dispersed is immediately added little by little to a batch cell while taking care not to enter bubbles, and the transmittance of the tungsten lamp becomes 90% to 95%. Adjust as follows. Then, the particle size distribution is measured. The volume-based median diameter (D50) is calculated based on the obtained volume-based particle size distribution data.

  In order to produce the toner of the present invention, binder resin, colorant, other additives, etc. are sufficiently mixed by a mixer such as a Henschel mixer or a ball mill and then heat kneaded such as a heating roll, a kneader or an extruder. Melt and knead using a machine. Thereafter, after cooling and solidification, pulverization and classification are carried out, and further desired additives are sufficiently mixed and added by a mixer such as a Henschel mixer, whereby the toner of the present invention can be obtained.

  As described above, this external addition step is important in reducing the amount of free external additives and uniformly depositing on the toner particle surface.

  As a production apparatus, for example, as a mixer, a Henschel mixer (manufactured by Mitsui Mining); a super mixer (manufactured by Kawata); a ribocorn (manufactured by Okawara Seisakusho); a nauter mixer, a turbulizer, a cyclomix (manufactured by Hosokawa Micron) A spiral pin mixer (manufactured by Taiheiyo Kiko Co., Ltd.); As a kneading machine, KRC kneader (manufactured by Kurimoto Iron Works); Bus co-kneader (manufactured by Buss); TEM type extruder (manufactured by Toshiba Machine); PCM kneader (manufactured by Ikegai Iron Works); three roll mill, mixing roll mill, kneader (manufactured by Inoue Seisakusho); kneedex (manufactured by Mitsui Mining Co., Ltd.); MS pressure kneader, nider ruder (manufactured by Moriyama Seisakusho); Banbury mixer (manufactured by Kobe Steel) can be mentioned. Among them, TEM type extruder (manufactured by Toshiba Machine Co., Ltd.); TEX twin-screw kneader (manufactured by Nippon Steel Works); PCM kneader (manufactured by Ikegai Iron Works Co., Ltd.); preferable. As a pulverizer, a counter jet mill, a micron jet, an inomizer (manufactured by Hosokawa Micron); an IDS type mill, a PJM jet pulverizer (manufactured by Nippon Pneumatic Industry Co., Ltd.); a cross jet mill (manufactured by Kurimoto Iron Works Co., Ltd.); SK Jet Oh Mill (manufactured by Seishin Enterprise Co., Ltd.); Kryptron (manufactured by Kawasaki Heavy Industries, Ltd.); Turbo Mill (manufactured by Turboue Industry Co., Ltd.); Classifiers include: Classy, Micron Classifier, Spedic Classifier (manufactured by Seishin Enterprise); Turbo Classifier (manufactured by Nissin Engineering); Micron Separator, Turboplex (ATP), TSP Separator (manufactured by Hosokawa Micron) ;elbow ET (manufactured by Nippon Steel & Mining Co., Ltd.), dispersion separator (manufactured by Nippon Pneumatic Engineering Co., Ltd.); YM micro cut (manufactured by Yaskawa Shoji Co., Ltd.), Ultrasonic (manufactured by Sakae Sangyo Co., Ltd.); Resonator Sheave, Gyroshifter (Tokusu Kosakusha Co., Ltd.); Vibrasonic System (manufactured by Dalton Co.); Soniclean (manufactured by Shinto Kogyo Co., Ltd.); Micro shifter (manufactured by Hadano Sangyo Co., Ltd.); circular vibrating sieve and the like.

  Hereinafter, the present invention will be described with reference to specific examples, but the present invention is not limited thereto.

The production method of the silica fine particles used in this example is shown below. A silica base material having a BET specific surface area of 300 m ² / g was used.

(Example of production of silica fine particles 1)
20.0 parts by mass of dimethyl silicone oil (viscosity = 100 mm ² / s) is sprayed on 100 parts by mass of the silica raw material, and after stirring for 30 minutes, the temperature is raised to 200 ° C. while stirring and further 2 The reaction was complete after stirring for a period of time. After completion of the reaction, crushing treatment was performed. Subsequently, 5 parts by mass of hexamethyldisilazane was sprayed on 100 parts by mass of the oil-treated silica, and the silane compound was treated in a fluidized state of silica. After this reaction was continued for 60 minutes, the reaction was terminated and silica fine particles 1 used in the present invention were obtained. Table 1 shows various physical properties of the silica fine particles.

  The carbon oil-based immobilization rate of silicone oil was calculated by measuring the immobilization rates of both the intermediate after the oil treatment and the silica fine particles.

(Production example of silica fine particles 2 and 3)
Silica fine particles 2 and 3 were obtained in the same manner as in silica fine particle production example 1 except that the treatment amount of dimethyl silicone oil (viscosity = 100 mm ² / s) was changed as shown in Table 1.

(Production Example of Silica Fine Particle 4)
Silica fine particles 4 were obtained in the same manner as in silica fine particle production example 1 except that the treatment amount of dimethyl silicone oil (viscosity = 100 mm ² / s), the silane compound species and the treatment amount were changed to Table 1.

(Production example of silica fine particles 5)
Silica fine particles 5 were obtained in the same manner as in silica fine particle production example 1 except that the treatment amount and treatment temperature of dimethyl silicone oil (viscosity = 100 mm ² / s) were changed as shown in Table 1.

(Example of production of silica fine particles 6)
7.0 parts by mass of dimethyl silicone oil (viscosity = 100 mm ² / s) was sprayed on 100 parts by mass of the silica base, and after stirring for 30 minutes, the temperature was raised to 200 ° C. and further stirred for 2 hours. . Thereafter, 6.0 parts by mass of dimethyl silicone oil (viscosity = 100 mm ² / s) was further sprayed, stirred for 30 minutes, and further stirred at 200 ° C. for 2 hours.

  After completion of the reaction, pulverization was performed, and then 5 parts by mass of hexamethyldisilazane was sprayed on 100 parts by mass of the oil-treated silica, and the silane compound was treated in a fluidized state of silica. After this reaction was continued for 60 minutes, the reaction was terminated and silica fine particles 6 used in the present invention were obtained. Table 1 shows various physical properties of the silica fine particles 6.

(Production example of silica fine particles 7 and 8)
After spraying the amount of dimethyl silicone oil (viscosity = 50 mm ² / s) shown in Table 1 to 100 parts by mass of the silica raw material, stirring was continued for 30 minutes, and then the temperature was raised to 150 ° C. while stirring. After stirring for 2 hours, the reaction was completed to obtain silica fine particles 7 and 8 used in the present invention. Various physical properties of the silica fine particles 7 and 8 are shown in Table 1.

(Production example of silica fine particles 9)
Silica fine particles 9 were obtained in the same manner as in silica fine particle production example 1 except that the treatment amount and treatment temperature of dimethyl silicone oil (viscosity = 100 mm ² / s), the silane compound species and the treatment amount were changed as shown in Table 1. It was.

(Production Example of Silica Fine Particle 10)
After spraying 5.0 parts by mass of dimethyl silicone oil (viscosity = 1000 mm ² / s) with respect to 100 parts by mass of the silica raw material, stirring was continued for 30 minutes, and then the temperature was raised to 200 ° C. Reacted for hours. Thereafter, 5.0 parts by mass of dimethyl silicone oil (viscosity = 1000 mm ² / s) was sprayed, and stirring was further continued for 30 minutes, and the reaction was similarly performed at 200 ° C. for 2 hours. Further, 5.0 parts by mass of dimethyl silicone oil (viscosity = 1000 mm ² / s) was sprayed, and stirring was continued for 30 minutes. The temperature was raised to 200 ° C. while stirring, and the reaction was completed after stirring for 2 hours. Thus, silica fine particles 10 used in the present invention were obtained. Various physical properties of the silica fine particles 10 are shown in Table 1.

(Example of production of silica fine particles 11)
30 parts by mass of hexamethyldisilazane was sprayed on 100 parts by mass of the silica base material, and the silane compound treatment was performed in a fluidized state of silica. After this reaction was continued for 60 minutes, 10.0 parts by mass of dimethyl silicone oil (viscosity = 50 mm ² / s) was sprayed, and stirring was continued for 30 minutes. The reaction was complete after stirring for a period of time. After completion of the reaction, pulverization was performed to obtain silica fine particles 11 used in the present invention. Table 1 shows various physical properties of the silica fine particles 11.

(Example of binder resin production)
Terephthalic acid 500g
600 g dodecenyl succinic acid
Trimellitic acid 350g
2000 g of bisphenol derivative represented by the formula (I)
(Propylene oxide 2.2 mol adduct)
800 g of bisphenol derivative represented by the formula (I)
(Ethylene oxide 2.2 mol adduct)
The acid component and alcohol component shown above and 4 g of dibutyltin oxide were charged into a four-necked flask and equipped with a decompression device, a water separation device, a nitrogen gas introduction device, a temperature measurement device, and a stirring device, and 230 ° C. in a nitrogen atmosphere. The reaction was carried out at an elevated temperature.

  After completion of the reaction, the product is taken out of the container, cooled and pulverized, Mp is 9,000, weight average molecular weight (Mw) is 600,000, Mw / Mn is 25, Tg is 58 ° C., THF insoluble components are 20. A binder resin (H) of 0% by mass was obtained.

next,
400g terephthalic acid
650 g of fumaric acid
2800 g of bisphenol derivative represented by the formula (I)
(Propylene oxide 2.2 mol adduct)
The acid component and alcohol component shown above and 4 g of dibutyltin oxide were charged into a four-necked flask and equipped with a decompression device, a water separation device, a nitrogen gas introduction device, a temperature measurement device, and a stirring device, and 230 ° C. in a nitrogen atmosphere. The reaction was carried out at an elevated temperature. After completion of the reaction, the product is taken out of the container, cooled and pulverized, Mp is 5,000, weight average molecular weight (Mw) is 80,000, Mw / Mn is 8.0, Tg is 55 ° C., THF insoluble components are present. No binder resin (L) was obtained.

  Binder resin (H) 50 mass parts and binder resin (L) 50 mass parts were mixed with the Henschel mixer, and it was set as binder resin.

(Example of toner production)
Binder resin 100 parts by mass Magnetic iron oxide particles (average particle size 0.15 μm, Hc = 11.5 kA / m, σs = 88 Am ² / kg, σr = 14 Am ² / kg) 75 parts by mass Fischer-Tropsch wax (melting point : 101 ° C.) 4 parts by mass of charge control agent-b-1 2 parts by mass

  The above materials were premixed with a Henschel mixer and then melt kneaded with a biaxial kneading extruder.

  The obtained kneaded product is cooled, coarsely pulverized with a hammer mill, then pulverized with a turbo mill, and the obtained finely pulverized powder is classified using a multi-division classifier utilizing the Coanda effect to obtain a weight average particle diameter (D4 ) 7.1 μm negatively chargeable magnetic toner particles were obtained.

With respect to 100 parts by mass of magnetic toner particles, 1.0 part by mass of silica fine particles 1 and 3.0 parts by mass of strontium titanate fine powder (D50: 1.0 μm) as an abrasive are mixed under external addition condition A, and the mesh is opened. The toner 1 was obtained by sieving with a 150 μm mesh. The toner formulation and physical property results are shown in Table 2.
-External addition condition A; using Henschel mixer (Mitsui Mining Co., Ltd.) FM-10C, 33.3S-
After 60 seconds of rotation at 1 (2000 rpm), the number of rotations is increased to 66.6 s-1 (4000 rpm) and further rotated for 120 seconds.
External addition condition B: Henschel mixer (Mitsui Mining Co., Ltd.) FM-10C was used, and 66.6 s-
Rotate for 180 s at 1 (4000 rpm).

[Example 1]
The peripheral part of the transfer device of a commercially available digital copying machine iR5075 (75 cpm, a-Si photosensitive drum mounted, magnetic one-component jumping development method, manufactured by Canon Inc.) was remodeled into the transfer conveyance belt type shown in FIG. . Further, the machine body was modified so that the process speed (= the peripheral speed of the photosensitive drum) was 550 mm / sec. The print speed was 110 cpm.

  Chloroplane rubber was used as the surface layer material of the transfer conveyance belt, and the intrusion amount i of the transfer conveyance belt with respect to the photosensitive member was set to 8.0.

  In this embodiment, the transfer conveyance belt is moved to the photoconductor side except during the start-up operation and the stop operation of the image forming apparatus (that is, the process speed (= photoconductor surface speed) of the apparatus main body is unstable). Press contact. In this embodiment, the peripheral speed of the transfer conveyance belt is set to be the same as the peripheral speed of the photosensitive member.

Using toner 1, the image ratio is 4% in the order of 23 ° C./50% RH environment (NN environment), 23 ° C./5% RH environment (NL environment), and 30 ° C./80% RH environment (HH environment). An endurance test was performed in which 500,000 character images were continuously printed on one side by A4 horizontal feed. As the durable paper, an office planner 68 g / m ² was used. At the end of each endurance test, evaluation of transfer dropout and transfer efficiency was performed.

  Evaluation was performed according to the following indicators. Table 3 shows the results.

<Evaluation of transfer omission>
At the end of the endurance test in the NN environment, an 8 mm square grid chart composed of 200 μm, 500 μm, 1 mm, and 2 mm line widths was printed on 250 g / m ² (A4) paper. Arbitrary 10 places on the second side print were observed visually and with a magnifying glass (× 30) and classified into the following evaluation ranks. C and above are levels at which a sufficient effect can be obtained in the present invention. The evaluation results are shown in Table 3.
A: No transfer omission B: Transfer omission is confirmed in a small part of the field of view by observation using a 30x magnifier C: Transfer omission is observed in a part of the field of view using a 30x magnifying glass Confirmed D: Partial transfer omission confirmed visually

<Evaluation of white spot>
Pass through the black images of the initial, 10,000th, 100,000th, 250,000th, and 500,000th sheets during endurance in an NL environment (23 ° C / 5%). A solid black image was observed, and the number of white spots generated for each image was measured.

From the total number of white spots on the five images, A to E were evaluated according to the following criteria. The level C or higher is a level at which a sufficient effect can be obtained in the present invention. The evaluation results are shown in Table 3.
A: No white spots occur. B: 1 to 2 white spots occur in total of 5 solid black images. C: 3 to 4 white spots occur in total of 5 solid black images. D: 5 or more and 6 or less white spots occur in total of 5 solid black images E: 7 or more white spots occur in total of 5 solid black images

<Evaluation of cleaning performance of transfer conveyor belt>
In the durability test under the HH environment, the back surface of the office planner paper was observed, and the cleaning failure was visually evaluated and evaluated in five stages according to the following evaluation items with a loupe (× 30). C and above are levels at which a sufficient effect can be obtained in the present invention. The evaluation results are shown in Table 3.
A: No cleaning failure occurred.
B: There are several cleaning defects with a width of 0.1 mm or less on the paper, but this is a minor level and causes no problem on the image.
C: There are several streaks with a width of 0.1 mm or more due to poor cleaning on the paper, and although it occurs slightly on the paper, it is not a level that causes a problem in actual use.
D: There are 10 or more cleaning defects on the paper, and the paper also appears. The level at issue.
E: Streaks due to poor cleaning are present on the entire surface of the paper, and a large number of lines are generated on the paper. It is a problematic level and cannot withstand actual use.

<Transcription explosion evaluation>
After endurance in NL environment (23 ° C / 5%), prober bond paper (105 g / m2, manufactured by Fox River) was used as an evaluation paper, and a horizontal line solid line image with a line width of 0.5 mm was output at 10 mm intervals. The line width of the output image was measured. The obtained result was quantified based on the weight width. Further, in order to distinguish from an explosion at the time of fixing, an image before fixing was taken out and evaluated.

C and above are levels at which a sufficient effect can be obtained in the present invention. The evaluation results are shown in Table 3.
A: Very good Less than 105% B: Good 105% or more and less than 110% C: Possible 110% or more and less than 115% D: May be problematic in practical use 115% or more and less than 120% E: Difficult to use 120% or more

<Evaluation of environmental variability>
It was determined by measuring the image density of the initial 100th and 500,000th test charts in HH, NL, and NN environments. The environmental variability was evaluated by subtracting the minimum value from the maximum density value of these six sheets of evaluation paper. The smaller this value, the less environmental variability. The image density was measured by measuring the reflection density of a 5 mm round solid black image using an SPI filter with a Macbeth densitometer (Macbeth Co.) which is a reflection densitometer.

C and above are levels at which a sufficient effect can be obtained in the present invention. The evaluation results are shown in Table 3.
A: Very good Concentration difference is 0.01 or less B: Good Concentration difference is 0.02 or more and 0.03 or less C: Possible Concentration difference is 0.04 or more and 0.05 or less D: There may be a practical problem. Concentration difference is 0.06 or more and 0.08 or less E: Difficult to use Concentration difference is 0.09 or more

<Evaluation of concentration variability>
It was determined by measuring the image density of the initial 100th, 10,000th, 100,000th and 500,000th test charts in the NN environment. The density variability was evaluated by subtracting the minimum value from the maximum density value of these four evaluation papers. The smaller this value, the less the density variability. The image density was measured by measuring the reflection density of a 5 mm round solid black image using an SPI filter with a Macbeth densitometer (Macbeth Co.) which is a reflection densitometer.

C and above are levels at which a sufficient effect can be obtained in the present invention. The evaluation results are shown in Table 3.
A: Very good Concentration difference is 0.01 or less B: Good Concentration difference is 0.02 or more and 0.03 or less C: Possible Concentration difference is 0.04 or more and 0.05 or less D: There may be a practical problem. Concentration difference is 0.06 or more and 0.08 or less E: Difficult to use Concentration difference is 0.09 or more

  As for Example 1, good results were obtained in any evaluation.

[Examples 2 to 13, Comparative Examples 1 to 3]
Toners 2 to 11 were prepared in the same manner as in Example 1 except that the type of silica fine particles was changed to the formulation shown in Table 2. The physical properties of the toner are shown in Table 2.

  Moreover, the result evaluated similarly is shown in Table 3. The set transfer amount of the transfer conveyance belt and the photosensitive member diameter are as shown in Table 3.

Example 14
Evaluation was performed in the same manner as in Example 1 except that the developing device was changed to that shown in FIG.

  The developing device includes a developing container 32 (developing device main body) that stores toner, a first toner carrier 33a and a second toner carrier 33b that are installed above and below the photosensitive member 31. Further, stirring members 38 and 39 are provided below the toner hopper 40 and convey the toner to the vicinity of the toner carriers 33a and 33b.

  This developing device is provided with a magnetic doctor blade 36 for the first toner carrier 33a located on the upstream side in the rotation direction of the photoconductor 31, thereby restricting the toner coat of the first toner carrier 33a. On the other hand, the second toner carrier does not have a doctor blade, and toner coat regulation is performed by a magnetic binding force or the like in the gap between the first toner carrier 33a and the second toner carrier 33b. Since there are more opportunities to develop an electrostatic charge image than in the case of a single toner carrier, it is preferably used for high image quality development such as light printing applications.

  Otherwise, the evaluation was performed in the same manner as in Example 1. The evaluation results are shown in Table 3.

  DESCRIPTION OF SYMBOLS 11: Photoconductor, 12: Transfer conveyance belt, 13: Drive roller, 14: Driven roller, 15: Bias roller, 16: High voltage power supply, 17: Cleaning backup roller, 18: Fur brush, 19: Transfer material, 21: Conductivity 22: photoconductive layer, 23: surface protective layer, 24: charge injection blocking layer, 25: lower photoconductive layer, 26: upper photoconductive layer, 27: antireflection layer or interface layer, 31: photoconductor, 32: developing device, 33a: first toner carrier, 33b: second toner carrier, 34, 35: magnet, 36: toner regulating member, 37: opening, 38, 39: stirring member, 40: toner hopper, α: rotation direction of the photoconductor, 41: upper part of jig, 42: lower part of jig, 43: mesh, 44: suction port, 45: suction hose

Claims (4)

The photosensitive member is charged, an electrostatic charge image is formed on the charged photosensitive member, and the electrostatic charge image is developed using toner on a toner carrier to form a toner image on the photosensitive member. Is an image forming method for transferring the image to a transfer material on a transfer conveyance belt,
The transfer conveyance belt is supported by at least two rollers installed upstream and downstream in the conveyance direction with respect to the transfer position,
When the amount of penetration of the transfer / conveying belt into the photoconductor is i (mm) and the diameter of the photoconductor is d (mm), the following equation (1) is satisfied:
d × 0.05 <i ≦ d × 0.15 (1)
The toner has toner particles containing at least a binder resin and a colorant, and at least silica fine particles,
An image forming method, wherein the silica fine particles are treated with silicone oil, and the carbon oil-based immobilization ratio of the silicone oil is 30% by mass or more and 95% by mass or less.   2. The image forming method according to claim 1, wherein the silica fine particles are hydrophobic silica fine particles which have been surface-treated with a silicone oil and then surface-treated with a silane compound and / or a silazane compound. When the wettability of the silica fine particles with a mixed solvent of methanol and water is 90% light transmittance at a wavelength of 780 nm, the methanol concentration is D90 (volume%), and when the transmittance is 70%, the methanol concentration is D70 (volume%). The image forming method according to claim 1, wherein the following expression (2) is satisfied.
D70−D90 ≦ 5.0 (2)   The electrostatic image is developed using the first toner carrier and the second toner carrier, and the first toner carrier on the upstream side in the rotation direction of the photosensitive member is on the second toner carrier on the downstream side. The image forming method according to claim 1, wherein the toner amount is regulated to a predetermined amount.

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