JP2001272811A - Image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming method in which even a hot pressing means not coated with an anti-offsetting fluid is made adaptable to various transfer materials without impairing the performance of the means over a long period of time. SOLUTION: In the image forming method, a toner image on a transfer material is fixed by heat pressing by a heat pressing means to form a fixed image on the transfer material. The toner forming the toner image is a dry toner containing at least a bonding resin, a colorant, a wax component and an oxycarboxylic acid, and the mass A (mg) of the oxycarboxylic acid extracted from 1 g toner by methanol and the mass B (mg) of the oxycarboxylic acid extracted from 1 g toner by an aqueous sodium hydroxide solution having 0.1 mol/l concentration satisfy A/B=1.05-3.00 and B=0.10-3.50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method used in a recording method utilizing an electrophotographic method, an electrostatic recording method, a magnetic recording method, a toner jet method or the like. More specifically, the present invention relates to an image forming method used in an image recording apparatus that can be used for a copying machine, a printer, a facsimile, a plotter, and the like.

[0002]

2. Description of the Related Art Conventionally, electrophotography has been disclosed in U.S. Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910.
Numerous methods are known as described in Japanese Patent Application Laid-Open Publication No. Hei. Generally, a photoconductive substance is used to form an electric latent image on a photoreceptor by various means, and then the latent image is developed using toner, and if necessary, using direct or indirect means. After transferring a toner image to a transfer material such as paper, the toner image is fixed by heating, pressurizing, heating and pressing, or solvent vapor to obtain a fixed image. In the case where a step of transferring a toner image is provided, a step for removing the transfer residual toner on the photoconductor is usually provided, and the above-described steps are repeated.

In addition, particularly in full-color image formation, a multi-color image is generally developed by developing an electrostatic latent image using magenta toner, cyan toner, yellow toner and black toner and superimposing toner images of each color. The image is being reproduced.

In recent years, the field of application of the image forming apparatus using the electrophotography described above is not limited to a copying machine for copying an original document, but also to a printer as an output of a computer or a personal copy for an individual. Further, it is rapidly developing into plain paper fax and the like, and a variety of demands are increasing. In addition, digital copiers are also becoming more sophisticated.
In particular, the size, speed, and color of the image forming apparatus have been remarkably reduced, and high reliability and high resolution have been strongly demanded. For example, initially, 200-300 dpi
(Dot per inch) resolution is 400
1,200 dpi, and 2400 dpi.

[0005] In response to the above demands, image forming apparatuses have been designed with simpler components by using members having high functionality in various points. As a result, the functionality required of the toner has become higher, and if the performance of the toner cannot be improved, a better image forming apparatus cannot be realized.

For example, a fixing device for fixing a toner image generally includes a heating roller as a rotary heating member and a pressure roller as a rotary pressing member (hereinafter, both are referred to as a fixing roller). Although a heat-fixing unit of a heat roller type using a toner is used, when performing image formation at a higher speed, a large amount of heat energy is required instantaneously while applying a high pressing force. For this reason, unfavorable situations such as an increase in the size of the fixing device and a long preheating time at the time of startup are caused. From these viewpoints, it is preferable that the toner used in the image forming apparatus as described above exhibits a high sharp melt property when heated. Also,
Such a toner is excellent not only in low-temperature fixing property but also in color mixing property at the time of forming a full-color image, so that the color reproduction range of the obtained fixed image can be expanded.

However, since the above toner generally has a high affinity with the fixing roller, it tends to easily cause an offset phenomenon to be transferred to the surface of the fixing roller at the time of fixing. In particular, a yellow toner, a magenta toner This phenomenon occurs remarkably at the time of forming a color image in which a plurality of toner layers are formed by cyan toner and black toner.

On the other hand, for the purpose of preventing the toner from adhering to the surface of the fixing roller, for example, a material having excellent releasability from the toner, such as silicone rubber or fluorine resin, is used for the surface material of the fixing roller. In order to prevent the offset phenomenon and the deterioration of the fixing roller surface, the fixing roller surface is coated with a thin film of an anti-offset liquid.

However, although the above method is extremely effective in preventing the offset phenomenon,
(1) Since a device for supplying an offset preventing liquid is required, the fixing device becomes complicated, which is an obstacle to designing a small and inexpensive image forming apparatus; The liquid for preventing offset oozes into the fixing roller when heated, causing separation between the layers constituting the fixing roller, thereby shortening the life of the fixing roller. (3) Offset of the obtained fixed image The prevention liquid adheres, causing a sticky feeling, and the transparency is impaired, especially when a transparency film used for overhead projectors for presentation is used as the transfer material, so that the desired color reproducibility is obtained. (4) An adverse effect such as the offset prevention liquid contaminating the inside of the image forming apparatus occurs.

On the other hand, transfer materials used in the above-described image forming apparatuses have been diversified. For example, as the type of paper used as a transfer material, at present, not only the difference in basis weight but also the material and content of raw materials and fillers are different. Among these transfer materials, there are various transfer material qualities, such as those in which constituent materials are easily detached and those which easily adhere to constituent members of a fixing device. These transfer materials greatly affect the fixing device, which makes it difficult to reduce the size and extend the life of the fixing device.

Further, there is a problem that contaminants derived from the transfer material and the toner are clumped and fixed on the fixing roller to cause a decrease in the performance of the fixing device, and the quality of the fixed image is impaired due to the peeling off of the fixed material. Had occurred.

In recent years, in particular, recycled paper using recycled pulp obtained by deinking paper once used has been widely used from the viewpoint of environmental protection and the like. However, recycled paper often contains various contaminants. For example, JP-A-3-28789, JP-A-4-65596, JP-A-4-147152, and JP-A-5-100.
As disclosed in Japanese Patent Application Publication No. 465-465 and Japanese Patent Application Laid-Open No. 6-35221, in order to enable use in the above-described image forming apparatus, the content of contaminants in the recycled paper is required. The quantity and composition need to be specified.

At present, in recycled paper used for general office work, etc., the blending ratio of recycled pulp such as newspaper waste paper exceeds 70%, and the blending amount is expected to increase further in the future.
There is a concern that this may cause the above problems. Furthermore,
When a cleaning member for removing toner and the like remaining after fixing on the surface of the heating roller and a separating member for preventing winding of the transfer material are provided, particularly, a medium waste paper such as a newspaper or a magazine is used as a raw material. It has been confirmed that the medium-quality pulp fibers contained in the paper powder detached from the recycled paper cause scratches and shavings on the surface of the fixing roller, and the functions of the cleaning member and the separating member are significantly reduced. The phenomenon described above tends to become a serious problem when a fixing device in which the amount of the offset preventing liquid applied to the fixing roller is small or a fixing device in which the offset preventing liquid is not applied is used.

As described above, applying the offset preventing liquid to the surface of the fixing roller of the fixing device is very useful, but has various problems.

In view of the recent demand for image forming apparatuses such as miniaturization and weight reduction and the quality of the obtained fixed image, it is preferable to remove even an auxiliary apparatus for applying an anti-offset liquid.

Under these circumstances, it is essential to develop a technology for fixing the toner under heat and pressure, and several measures have been proposed for these.

Conventionally, there has been a number of methods for adding a wax component such as polyethylene or polypropylene of low molecular weight to a toner from the viewpoint of supplying the offset preventing liquid from the toner during heating without using an offset preventing liquid supply device. Proposed. However, in order to exhibit a sufficient effect, it is necessary to add a large amount of the wax component to the toner as described above. In this case, filming on the photoconductor or contamination of the surface of the toner carrier such as a carrier or a sleeve is required. And a new problem such as image deterioration occurs. Also,
If the amount of the wax component is small, it is necessary to provide a device for supplying a small amount of the liquid for preventing offset, or an auxiliary cleaning member such as a rewind-type cleaning web or a cleaning pad.
Especially when forming a full-color image, when a transparency film is used as a transfer material, the transparency and haze (haze value) of the fixed image are due to high crystallization of the wax component and a difference in the refractive index from the binder resin. The problem of worsening remains unresolved.

Japanese Patent Publication No. 52-3304, Japanese Patent Publication No. 52-3305, Japanese Patent Application Laid-Open No. 57-52574, Japanese Patent Application Laid-Open No. 60-217366, and Japanese Patent Application Laid-open No.
No. 52360, JP-A-60-252361,
JP-A-61-94062, JP-A-61-1382
No. 59, JP-A-61-273554, JP-A-62-14166, JP-A-1-109359, JP-A-2-79860 and JP-A-3-505
No. 59 discloses a technique of including a wax component in a toner, but it is difficult to highly improve various properties required of the toner by simply including a wax component in the toner. In addition, matching with an image forming apparatus using a heat-press fixing method is not sufficient.

Further, in Japanese Patent Application Laid-Open No. 4-35657 (corresponding to US Pat. No. 5,391,450), a heating member which is in pressure contact with a toner image is formed of a fluorine-containing substance.
The toner has a weight average molecular weight (Mw) of 500 to 1500
Is disclosed, but no consideration is given to matching with a fixing device.

In the art, it is widely known to use a charge control agent to improve the chargeability of a toner. As a negative charge, a metal complex salt of a monoazo dye, a metal complex salt of salicylic acid, Examples thereof include a metal complex salt of naphthoic acid, a metal complex salt of dicarboxylic acid, and a copper phthalocyanine pigment.

The charge control agent as described above imparts an appropriate amount of charge to the toner by frictional charging or the like. The charged toner is not only used for development but also required for fixing on the transfer material. During this time, it plays a role of keeping the toner image faithfully on the transfer material by the electrostatic force.

However, none of the above-mentioned toners containing a charge control agent is considered in the heat and pressure fixing method.

For example, JP-A-63-33755 discloses
JP-A-2-190869, JP-A-2-23016
No. 3 and JP-A-4-347632 disclose a method for controlling the charge of toner using salicylic acid or a derivative thereof. However, according to the study of the present inventors, salicylic acid and its derivatives are often colorless or white, and although they are particularly useful as charge control agents for color toners, they themselves have strong oxidizing ability and interface properties. Due to the activator-like behavior, the deterioration of the surface material of the fixing roller is promoted, or the effect of the addition of the wax component contained in the toner is lost, which may cause a problem during image fixing.

Japanese Patent Application Laid-Open Nos. 61-238846 and 5-13444437 disclose a method of depositing a charge control agent on the toner surface.
Japanese Patent Publication No. 8 discloses a technique relating to a toner in which the dye concentration of a charge control dye on the surface of toner particles is specified.
However, in these methods, no consideration is given to the influence of the charge control agent or the charge control dye transferred to the surface of the fixing roller.

In particular, these phenomena are caused by using recycled paper having a blending ratio of recycled pulp exceeding 70% as a transfer material,
When forming a color image in which a plurality of toner layers formed on a transfer material must be fixed at a time, or when a fixing device with a small amount of offset prevention liquid applied to a fixing roller, or an offset prevention liquid is applied. Notably, when a fixing device not used is used.

As described above, there is not yet enough comprehensive system design including the toner for the system design of the image forming apparatus using the heat and pressure fixing method.

[0027]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the problems of the prior art and to provide a heating and pressurizing means with a small amount of application of the offset preventing liquid, or a heating apparatus in which the application of the offset preventing liquid is not performed at all. It is an object of the present invention to provide an image forming method which can be applied to various transfer materials without deteriorating the performance of the heating / pressing means for a long time even if a pressing means is used.

An object of the present invention is to provide an image forming method capable of obtaining a fixed image with high resolution and high definition.

An object of the present invention is to provide an image forming method capable of obtaining a fixed image in a good fixed state.

An object of the present invention is to provide an image forming method capable of obtaining a high-quality full-color fixed image having excellent color reproducibility and no stickiness, and forming a fixed image having excellent transparency on a transparency film. It is an object of the present invention to provide an image forming method that can be performed.

[0031]

The present invention relates to an image forming method for forming a fixed image on a transfer material by heating and pressurizing and fixing a toner image on a transfer material by a heating and pressurizing means. Comprises: (i) a rotary heating member having at least a heating element, and a rotary pressing member for forming a nip portion by mutual pressure contact with the rotary heating member, and (ii) contact with the toner image on the transfer material. The consumption of the offset preventing liquid applied to the surface is set to 0 to 0.025 mg / cm ² (based on the unit area of the transfer material), and (iii) while nipping and transferring the transfer material in the nip portion, The toner image on the transfer material is heated and pressed by the rotary heating member and the rotary pressing member, and the toner forming the toner image includes at least a binder resin, a colorant, a wax component, and an oxycarboxylic acid. Containing dry In the toner, the mass A (mg) of oxycarboxylic acid extracted by methanol from 1 g of the toner and the mass B (mg) of oxycarboxylic acid extracted by 0.1 mol / liter sodium hydroxide aqueous solution are as follows. , A / B = 1.05 to 3.00 B = 0.10 to 3.50.

In view of the above, the present inventors have conducted intensive studies and as a result, have found that the heating and pressing means with a small application amount of the offset preventing liquid or the heating and pressurizing means with no application of the offset preventing liquid are applied. It has been found that by applying a toner whose acid content is specified, it is possible to adapt to various transfer materials without impairing the performance of the heating and pressurizing means over a long period of time and to form an excellent fixed image. Thus, the present invention has been completed.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to preferred embodiments of the present invention.

In the image forming method of the present invention, the "heating and pressurizing means" is to heat and pressurize and fix a toner image on a transfer material to form a fixed image.
(I) a rotary heating member having at least a heating element, and a rotary pressing member for forming a nip portion by mutual pressure contact with the rotary heating member; and (ii) a contact surface of the transfer material with the toner image. Consumption of the applied anti-offset liquid is 0 to
0.025 mg / cm ² (based on the unit area of the transfer material). (Iii) Toner on the transfer material by the rotary heating member and the rotary pressing member while nipping and transporting the transfer material in the nip portion. The image is heated and pressurized.

The "rotary heating member" constituting a part of the heating and fixing means is for applying heat for fixing a toner image on a transfer material, and is described later in (i) a heat roller system. (I) a cylindrical member having a heating element therein for applying heat to the toner image,
i) A cylindrical heater which is used for a film-type heating / pressurizing means and has a heating element fixedly supported by a support for applying heat to a toner image and which is driven to move while being pressed against the heating element. Heat-resistant endless film-like member; (iii) used for heating and pressurizing means of electromagnetic induction type, having a magnetic field generating means inside, and applying heat to the toner image by generating electromagnetic induction by the action of the magnetic field generating means. And a cylindrical heat-resistant endless film-like member having a heat-generating layer.

The "rotation pressing member" means that a nip portion is formed by mutual pressure contact with the rotation heating member, and the toner image on the transfer material is heated and pressed while nipping and transporting the transfer material at the nip portion. Things.

In the image forming method of the present invention, the consumption of the offset preventing liquid applied to the contact surface of the transfer material with the toner image is 0 to 0.025 mg / cm ² (based on the unit area of the transfer material). More preferably, the offset preventing liquid is set in a state where it is not applied at all. This makes it possible to solve the above-mentioned problems caused by the offset preventing liquid beforehand, and to maintain the performance of the above-mentioned heating and pressurizing means for a long period of time by using a toner described later, thereby obtaining an excellent fixed image. Can be obtained.

The consumption of the offset preventing liquid is measured by using recycled paper for general office use (the blending ratio of recycled pulp ≧ 70%) corresponding to the maximum paper passing area of the target heating and pressurizing means. It is defined as a value (mg / cm ² ) obtained by dividing the mass (mg) of the offset preventing liquid consumed when 100 sheets of paper are passed by the total area (cm ² ) of the used recycled paper.

As the liquid for preventing offset according to the present invention, a liquid which maintains a liquid state from -15 ° C. to nearly 300 ° C. and has excellent releasability is used. Specific examples include dimethyl silicone oil and modified silicones in which a part of the methyl group is replaced by other substituents, and mixtures thereof and those in which a small amount of a surfactant is added.
000 cSt is preferably used.

As a method of applying the above-described offset preventing liquid to the fixing roller, a conventionally known method is used. A method of applying the liquid by impregnating it into a coating felt, a felt pad, a felt roller, a web, a Poeflon rod, or the like. And a method of directly applying with an oil pan, a drawing roller or the like.

The preferred heating and pressurizing means used in the image forming method of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a cylindrical heating roller having a heating element therein as a rotary heating member, a cleaning member for removing toner remaining after fixing on the surface of the heating roller, and a winding member for preventing winding of the transfer material. It is the schematic of an example of the heating pressurizing means of a heat roller type in which a separation member is not arrange | positioned.

A rotary heating member comprising a cylindrical heating roller 11 having a heating element therein, such as a heater 11a;
The cylindrical pressure roller 12 as a rotary pressure member is
The two are pressed against each other to form a nip, and when activated, each rotates in the direction of the arrow.

The transfer material P as a material to be heated, which carries the unfixed toner T as a toner image, is transported by a transport belt 13 from the right side (upstream side) of the drawing.
By heating and pressurizing the transfer material P while nipping and transporting the same at the nip portion between the transfer material P and the pressure roller 12, a fixed image is formed on the transfer material P and discharged to the left (downstream side) in the drawing.

In the heating and pressurizing means according to the present invention, the separation claw 1 for separating the transfer material P from the heating roller 11 and the pressure roller 12 as shown in FIGS.
It does not have 4a or 14b.

Further, as shown in FIG. 2A, the brush-like fiber for applying the offset preventing liquid while removing the residual toner remaining on the surface of the heating roller 11 is formed into a cylindrical shape. An implanted cleaning roller 15, a felt-like oil pad 16 impregnated with an offset preventing liquid, and a cleaning roller 17 impregnated with an offset preventing liquid as shown in FIG. In this case, the consumption of the offset preventing liquid with respect to the transfer material is 0 to 0.025 mg / cm ^2.
Is set to be within the range.

Conventionally, since the offset preventing liquid also has a role of protecting the surface of the heating roller and the pressure roller, when the consumption of the offset preventing liquid is set in the above range, the role is sufficient. The surface of the heating roller 11 and the pressure roller 12 is liable to be scratched or scraped due to long-term use, and furthermore, the releasability is reduced due to them. In the heating and pressing means in such a state, the phenomenon of winding of the transfer material around the heating roller and the pressing roller is likely to occur, and when the separation claw as described above is eliminated, a serious problem occurs. By using the toner described below, the load on the heating and pressurizing means as described above is reduced, and an excellent fixed image can be obtained over a long period of time.

The heating roller 11 used in the heating and pressurizing means according to the present invention is, for example, an aluminum pipe having a thickness of about 2 to 5 mm as a core metal, and has a thickness of 20 mm on its outer peripheral surface.
Silicone rubber having a thickness of 0 to 500 μm or one coated with Teflon (registered trademark) is used.

As the pressure roller 12, for example, a roller in which a SUS pipe having a diameter of 10 mm is used as a core metal and its outer peripheral surface is coated with a silicone rubber to a thickness of about 3 mm is used.

As the heater 11a provided inside the heating roller 11, a tubular heating heater such as a halogen lamp is used. The heater generates heat when a predetermined voltage is applied, and the heating roller 11 is heated by radiant heat. . At this time, the heating roller 11 and the pressure roller 12 pressed against it are heated relatively slowly, but generally have a large heat capacity, and thus are often heated for a long time. 1
2 is susceptible to thermal degradation. In particular, when recycled paper is used or when the amount of the anti-offset liquid applied is small, the heating roller 11 and the pressure roller 12 are liable to be scratched or scraped. Problems arise due to a reduction in moldability. However, by using the toner described later, the load on the heating and pressurizing unit as described above is reduced, and it is possible to obtain an excellent fixed image over a long period of time.

FIG. 3A shows a cylindrical heat-resistant endless film which has a heating body fixedly supported by a support and is driven and moved while being pressed against the heating body. FIG. 3B is an exploded perspective view of an example of a film-type heating and pressing unit that heats and presses a toner image via a film, and FIG. 3B is an enlarged cross-sectional view of a main part of the heating and pressing unit.

A rotary heating member consisting of a cylindrical heat-resistant endless film 32 having a heating body 31 fixedly supported on a support inside, and a cylindrical heating member as a rotary pressing member via the heat-resistant endless film 32. The pressure roller 33 is pressed against each other to form a nip portion, and at the time of operation, rotates in the direction of the arrow to bring the transfer material as a heated body carrying the toner image into close contact with the heat-resistant endless film 32 and heat the body. 31 and is moved and driven together with the heat-resistant endless film 32.

The fixedly supported low heat capacity linear heating element 31
Is a heater substrate 31a, an energized heating resistor (heating element) 31
b, a surface protection layer 31c, a temperature sensing element 31d, and the like.

The heater substrate 31a has heat resistance, insulation,
A member exhibiting low heat capacity and high thermal conductivity is preferable, for example, an alumina substrate having a thickness of 1 mm, a width of 10 mm, and a length of 240 mm.

The heating element 31b is formed along the longitudinal direction substantially in the center of the lower surface of the heater substrate 31a (facing the film 32), for example, Ag-Pd (silver palladium), Ta ₂ N,
An electric resistance material such as RuO ₂ is about 10 μm in thickness and 1 to 3 in width.
mm in a linear or narrow band shape by screen printing or the like.
It was coated with 0 μm.

The temperature detecting element 31d is, for example, a heater substrate 3
This is a low-heat-capacity resistance thermometer, such as a Pt film, which is provided by coating a substantially central portion of the upper surface of 1a (the side opposite to the surface provided with the heating element 31b) by screen printing or the like. Note that a thermistor having a low heat capacity can be used instead.

The heating element 31 energizes the heating element 31b at a predetermined timing according to an image formation start signal, thereby causing the heating element 31b to generate heat over substantially the entire length.

The energization is performed at 100 VAC and the temperature detecting element 31
The supplied power is controlled by controlling the phase angle to be energized by an energization control circuit (not shown) including a triac according to the detected temperature of c.

Since the heating element 31 has a small heat capacity of the heater substrate 31a, the heating element 31b and the surface protection layer 31c, the surface of the heating element 31 rapidly rises to a desired fixing temperature by energizing the heating element 31b. When not used, since it is rapidly cooled to around room temperature, the thermal shock applied to the heat-resistant endless film 32 and the pressing roller 33 as a rotary pressing member is large, so that it is releasable. As a result, the load on the heating and pressurizing means as described above can be reduced, and an excellent fixed image can be obtained over a long period of time.

The cylindrical heat-resistant endless film 32 located between the rotary heating member and the rotary pressing member has a thickness of 2 mm from the viewpoint of heat resistance, strength assurance, durability and low heat capacity.
It is preferably a heat-resistant sheet composed of a single layer or a composite layer having a thickness of 0 to 100 μm. For example, polyimide, polyetherimide (PEI), polyethersulfone (P
ES) tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA), polyether ether ketone (PEEK), polyparabanic acid (PPA),
Alternatively, a composite layer film, for example, a polyimide film having a thickness of 20 μm, at least on the toner image contacting surface side, a fluororesin such as tetrafluoroethylene resin (PTFE), PAF, FEP, or a silicone resin, and further, carbon black, graphite, or the like. It is preferable that a release coating layer to which a conductive material such as a conductive whisker is added is applied to a thickness of 10 μm.

The pressing roller 3 which is a rotary pressing member
3 also serves as a drive roller for moving and driving the heat-resistant endless film 32 as described above, so that it not only has excellent releasability from toner and the like, but also has adhesion to the heat-resistant endless film 32. Preferably, for example, a rubber elastic body such as silicone rubber is used. As described above, the thermal shock applied to the pressure roller 33 is large, and the deterioration of the surface of the pressure roller 33 due to long-term use affects the drive function itself of the heating and pressure means as described above. As a result, the load on the heating and pressing means as described above can be reduced, and an excellent fixed image can be obtained over a long period of time.

FIG. 4 shows an electromagnetic induction heating device having a rotary heating member made of a cylindrical heat-resistant endless film having a magnetic field generating means inside and a heating layer for generating electromagnetic induction by the action of the magnetic field generating means. It is a schematic diagram of an example of a pressing means.

The excitation coil 40, the excitation coil 40
The heat-resistant endless film 4 supporting the coil core material (magnetic material) 42 and the excitation coil 40
7, a rotary heating member including a cylindrical heat-resistant endless film 47 which is driven to move while being pressed against the magnetic-field generating means, and a heat-resistant endless film 47. And a cylindrical pressing roller 48 serving as a rotary pressing member. The pressing member 48 is pressed against each other to form a nip portion N, and at the time of operation, rotates in the direction of an arrow to transfer a transfer material as a heated member carrying the toner image T. P is brought into close contact with the heat-resistant endless film 47 and pressed against the magnetic field generating means.
Together with it.

At this time, the magnetic field generated by the magnetic field generating means is 10 to 500 kHz from an excitation circuit (not shown).
When the alternating current of the frequency is applied, the magnetic flux H indicated by the arrow around the exciting coil 40 repeatedly generates and disappears. An eddy current A as shown by an arrow is generated in the conductive layer (induction magnetic material) 47b in the heat-resistant endless film 47 moving in the fluctuating magnetic field by electromagnetic induction so as to reduce a change in the magnetic field. . This eddy current is converted into Joule heat by the skin resistance of the conductive layer, and as a result, the conductive layer in the heat-resistant endless film 47 becomes a heating layer. As described above, since heat is directly generated near the surface layer of the heat-resistant endless film 47, rapid heating independent of the thermal conductivity and heat capacity of the film base layer and the thickness of the heat-resistant endless film can be realized.

The transfer material P carrying the toner image T as a member to be heated passes through the nip portion N in close contact with the heat-resistant endless film 47, whereby a fixed image can be obtained on the transfer material P.

The cylindrical heat-resistant endless film 47 used in the heating and pressurizing means according to the present invention is preferably composed of at least three layers: a film base layer 47a, a conductive layer 47b, and a surface layer 47c. Thickness 1
A heat-resistant resin such as polyimide having a thickness of 0 to 100 μm is used as the film base layer 47a, and a conductive layer 47b is formed on the outer peripheral surface of the base layer 47a (on the pressure-contact surface side of the body to be heated) by, for example, Ni, Cu, Cr.
Are formed in a thickness of 1 to 100 μm by plating or the like. Further, the surface layer 47c is formed by mixing or coating the free surface of the conductive layer 47b with a heat-resistant resin such as PFA or PTFE with good toner release, or by itself. Further, the film base layer 47a may have a role of a conductive layer to have a two-layer structure.

The coil core 42 is made of, for example, ferrite permalloy having a high magnetic permeability and a low residual magnetic flux density. A material having a low residual magnetic flux density is
In this case, the overcurrent generated in the core material itself can be suppressed, so that heat is not generated from the coil core material 42 and the efficiency is improved. Further, by using a material having a high magnetic permeability, the coil core material 42 becomes a path for the magnetic flux H, and leakage of the magnetic flux to the outside can be suppressed as much as possible.

The excitation coil 40 is formed by bundling a plurality of copper thin wires (bundled wires), each of which is insulated and coated, one by one as a conductive wire (electric wire), and is formed by winding this wire a plurality of times. Alternatively, a sheet coil substrate may be used in which the excitation coil pattern is multi-layer printed on a non-magnetic substrate plane such as epoxy resin containing glass (general-purpose electric substrate) or ceramic.

The sliding plate 43 is made of a heat-resistant resin such as a liquid crystal polymer or phenol.
In order to reduce the frictional resistance with the heat-resistant endless film 47, for example, a resin coat such as PFA or PTFE or a glass coat having a high slipperiness is applied to the surface facing the heat-resistant endless film 47.

The pressure roller 48 is formed by winding a silicone rubber, a fluorine rubber or the like around a cored bar. The pressure roller 48 is disposed by being pressed against the lower surface of the sliding plate 43 via a heat-resistant endless film 47 with a predetermined pressing force F by a bearing means and an urging means (neither is shown). The nip portion N is formed while sandwiching the heat-resistant endless film 47 therebetween.

Since the magnetic field generated by the magnetic field generating means is concentrated in the nip portion N, the vicinity of the surface layer of the heat-resistant endless film 47 rapidly and directly generates heat by electromagnetic induction heat generation. As a result, a large thermal shock is applied to the surface of the heat-resistant endless film 47 and the pressure roller 48, and the releasability to toner and the like and the heat-resistant endless film 47.
However, the use of the toner described below reduces the load on the heating and pressing means as described above, and makes it possible to obtain an excellent fixed image over a long period of time.

One of the features of the image forming method of the present invention is to use a toner whose oxycarboxylic acid content is specified.

The toner according to the present invention is a dry toner containing at least a binder resin, a colorant, a wax component, and oxycarboxylic acid, and the mass A of oxycarboxylic acid extracted from 1 g of the toner with methanol. (M
g) and the mass B (m) of oxycarboxylic acid extracted with a 0.1 mol / liter aqueous sodium hydroxide solution.
The content of the oxycarboxylic acid is specified so that g) satisfies A / B = 1.05 to 3.00 B = 0.10 to 3.50.

As a result of intensive studies, the present inventors have found that the heating and pressurizing means using a small amount of the anti-offset liquid or a heating and pressurizing means to which no anti-offset liquid is applied is used. It has been found that it is possible to adapt to various transfer materials without deteriorating the performance of the pressure means over a long period of time, and to obtain a high-resolution and high-definition fixed image.

The mass A of oxycarboxylic acid extracted with methanol from 1 g of toner (hereinafter referred to as “oxycarboxylic acid amount A”) is determined based on the surface of the toner particles and the surface layer portion where methanol can penetrate (near the surface). And the mass B of oxycarboxylic acid extracted from the toner with a 0.1 mol / L aqueous sodium hydroxide solution (hereinafter referred to as “oxycarboxylic acid amount B”). ) Is the amount (mg) of oxycarboxylic acid present on the surface of the toner particles, and the present inventors have determined that each of these is the charge of the toner just before forming a fixed image on the transfer material. It is thought that it controls the oxidizing ability and the appearance of surfactant-like behavior on the surface of the rotating and heating member and the rotating and pressing member of the heating and pressing means after the fixing image formation. There.

In the toner according to the present invention, by setting the amount B of oxycarboxylic acid to 0.10 to 3.50 mg, the formation of an unfixed toner image from the development step to the transfer step is improved only. Instead, the toner image formed on the transfer material can be held in an appropriate charged state.

That is, the amount B of oxycarboxylic acid is 0.10 m
If it is less than g, sufficient chargeability cannot be imparted to the toner particles, and problems such as image fogging and transfer failure tend to occur during toner image formation from the development step to the transfer step.
Further, after the toner image is formed, the image forming apparatus is easily affected by an impact or the like received while the toner image is conveyed to the heating and pressing means.

On the other hand, the amount B of oxycarboxylic acid is 3.50 m
g, the toner particles are excessively charged.
At the time of toner image formation from the development process to the transfer process, the image density and the reproducibility of the line image are likely to be reduced due to the reduction in development efficiency and transfer efficiency. In addition, when a fixed image is formed by the heating and pressing means, an offset phenomenon due to electrostatic attraction to a rotating heating member, scattering of a line image occurs, and adhesion of paper powder such as pulp or filler detached from a transfer material. Is generated. As a result, the surface of the rotation heating member or the rotation pressing member is scratched or scraped, and further, toner sticking occurs, causing toner contamination on the back surface of the fixed image or the printout image.

Further, since the oxycarboxylic acid in the toner has a high affinity with the paper powder as described above, it promotes thermal deterioration while adhering to the rotary heating member and the rotary pressing member together with the paper powder. The releasability and the mutual press-contact state of the surface of the member and the rotary pressing member are deteriorated. In particular, in the heating and pressurizing means of the film type or the electromagnetic induction type, there is a problem in the movement drive of the heat-resistant endless film.

The problem as described above is that when a transparency film or recycled paper or the like having a high blending ratio of recycled pulp is used as a transfer material, the rotating heating member of the heating and pressing means or the surface of the rotating and pressing member may be used for a long time. If you are tired,
Further, when the amount of the anti-offset liquid applied to the heating and pressurizing means is small, or when the anti-offset liquid is not applied at all, it becomes apparent that the toner according to the present invention contains oxycarboxylic acid in the toner. By specifying the state, the load on the heating and pressurizing means as described above is reduced, and an excellent fixed image can be obtained over a long period of time.

On the other hand, the toner according to the present invention provides quick and uniform charging characteristics by setting the ratio (A / B) of the oxycarboxylic acid amount A to the oxycarboxylic acid amount B to 1.05 to 3.00. It is possible to make the oxidizing ability and the surfactant-like behavior of the oxycarboxylic acid appropriate.

In particular, when the amount A of the oxycarboxylic acid and the amount B of the oxycarboxylic acid satisfy the relationship of A ≦ (3/4) B + 1, the above-mentioned problem is prevented beforehand, and the heating and pressing fixing means is used. Is more favorable.

When the ratio (A / B) of the amount A of the oxycarboxylic acid to the amount B of the oxycarboxylic acid is less than 1.05, the charging characteristics of the toner cannot be improved, and the ratio A / B is 3 .
If it exceeds 00, the oxidizing ability of the oxycarboxylic acid and the behavior as a surfactant become vigorous, so that not only the thermal deterioration of the rotary heating member and the rotary pressing member is promoted, but also the wax contained in the toner. The release effect of the component may be lost. In particular, when a full-color image is formed in which a plurality of toner layers are formed on a transfer material, or when the amount of applied anti-offset liquid is small, or when a heating and pressurizing unit in which no application of offset-preventive liquid is used is used, Partial fixing failure or offset phenomenon occurs.

The oxycarboxylic acids according to the present invention include:
Known compounds can be used, but compounds represented by the following formulas (1) and (2) are preferably used from the viewpoint of the charge imparting ability.

[0085]

Embedded image [In the above formula (1), (A) is selected from the following group, and X ₁
Represents a hydrogen atom, a sodium atom, a potassium atom, ammonium or an aliphatic ammonium. ]

[0086]

Embedded image

[0087]

Embedded image [In the above formula (2), X ₂ represents a hydrogen atom, a sodium atom, a potassium atom, ammonium, or an aliphatic ammonium, and R ₄ represents a C _{1 to} C ₂₂ alkyl group or alkenyl group, or an aryl group. , R ₅ are hydrogen atoms, C ₁ -C
_{22 represents} an alkyl group, an alkenyl group, an aryl group, and an alkoxy group. ]

Among the oxycarboxylic acids represented by the above formulas (1) and (2), those preferably used in the present invention are oxycarboxylic acids having an aromatic ring,
Monoalkyl aromatic oxycarboxylic acids or dialkyl aromatic oxycarboxylic acids are mentioned. In particular, salicylic acid, alkylsalicylic acid typified by di-tert-butylsalicylic acid and 5-tert-octylsalicylic acid, hydroxynaphthoic acid, benzylic acid, etc. are preferably used in the present invention because they can be easily fixed to the toner surface.

The following are typical examples of specific compounds.

[0090]

Embedded image

[0091]

Embedded image

[0092]

Embedded image

[0093]

Embedded image

[0094]

Embedded image

In the present invention, the amount A of the oxycarboxylic acid extracted from the toner with methanol is 0.1 m
The amount B of oxycarboxylic acid extracted with an aqueous solution of sodium hydroxide at ol / liter can be determined by a conventionally known analysis method. Specific examples are described below.

50 ml of a 0.1N aqueous sodium hydroxide solution containing methanol and 0.04 g of contaminone as a dispersing agent was prepared in separate containers, 1 g of the toner was weighed and added to each container, and a stirrer was used. 50 rpm
And uniformly disperse. After the dispersion treatment for 3 hours, the membrane filter (pore size: 0.45 μm)
m), and the absorbance of the obtained filtrate is measured. The absorbance is defined as the difference between the maximum value of one peak appearing in the range of 280 to 350 nm and the baseline. From the obtained results, the oxycarboxylic acid amount A and the oxycarboxylic acid amount B in the toner were calculated using a predetermined calibration curve.

In the toner according to the present invention, the effect of adding the oxycarboxylic acid present in the toner can be made efficient by producing a toner having particularly good circularity distribution.

In the toner according to the present invention, the circle-equivalent number average diameter D ₁ (μm) of the toner is 2 in the circle equivalent diameter-circularity scattergram based on the number of toners measured by the flow type particle image measuring apparatus. By controlling the particle shape of the toner precisely so that the average circularity of the toner is 0.920 to 0.995 and the circularity standard deviation is less than 0.040. The charging characteristics of the toner by the acid are improved in a well-balanced manner, and at the same time, the oxidizing ability of the oxycarboxylic acid to the heating and pressurizing means and the behavior as a surfactant become appropriate, so that the matching with the image forming apparatus is remarkably improved.

That is, the circle-equivalent number average diameter D ₁ (μ
By reducing the particle size of m) to 2 to 10 μm, the reproducibility of the contour portion of the image, particularly, the development of a character image or a line pattern becomes good. The average circularity of the circularity frequency distribution of the toner is 0.920 to 0.995, preferably 0.950 to 0.995, and more preferably 0.970 to 0.995.
By setting the ratio to 0.990, the charging characteristics of the toner exhibiting a small particle diameter, which has been difficult to control in the past, are greatly improved, and the developing ability for a low-potential latent image is significantly improved. In particular, the above tendency is very effective when developing a digital minute spot latent image or when forming a full-color image in which an intermediate transfer body is used to perform multiple transfers, and the matching with the image forming apparatus is also good. It becomes something.

Further, the toner of the present invention has a circularity standard deviation of the circularity frequency distribution of the toner of less than 0.040, preferably less than 0.035, and more preferably 0.015 or more.
By setting it to be less than 035, the problem relating to the developability can be significantly improved.

The average circularity of the circularity frequency distribution is equal to 0.
By setting the toner particles having a particle size of less than 950 to 15% or less, the development efficiency in image formation becomes a sufficient level, and the image formation becomes good.

As described above, the control of the average circularity, the circularity standard deviation and the number of toners having a circularity of less than 0.950 is controlled by the pH of the aqueous dispersion medium during the polymerization reaction in the production method of the toner by the polymerization method. It is possible.

The circle equivalent diameter, circularity, and frequency distribution of the toner in the present invention are used as a simple method for quantitatively expressing the shape of the toner particles. Equipment "FPIA-1000"
(Manufactured by Toa Medical Electronics Co., Ltd.) and calculated using the following equation.

[0104]

(Equation 2)

Here, the “particle projection area” is the area of the binarized toner particle image, and is the “perimeter of the particle projection image”.
Is defined as the length of the contour obtained by connecting the edge points of the toner particle image.

The circularity in the present invention is an index indicating the degree of unevenness of the toner. The circularity is 1.000 when the toner is perfectly spherical, and the circularity becomes smaller as the surface shape becomes more complicated.

In the present invention, the circle-equivalent number average diameter D ₁ (μ) means the average value of the particle size frequency distribution based on the number of toners.
m) and the particle size standard deviation SDd are calculated from the following equation, where di is the particle size (center value) at the dividing point i of the particle size distribution, and f _i is the frequency.

[0108]

(Equation 3)

[0109]

[0110]

(Equation 4)

As a specific measuring method, 10 ml of ion-exchanged water from which impure solids and the like have been removed in advance is prepared in a container, and a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersing agent thereto. Further, 0.02 g of the measurement sample is added and uniformly dispersed. As a means for dispersing, an ultrasonic disperser “UH-50 type” (manufactured by SMT Corporation) equipped with a titanium alloy chip of 5φ as a vibrator is used, and a dispersion treatment for 5 minutes is performed. I do. At this time, the dispersion is appropriately cooled so that the temperature of the dispersion does not become 40 ° C. or higher.

For the measurement of the shape of the toner, the above-mentioned flow type particle image measuring device was used.
The concentration of the dispersion is readjusted so as to be about 10,000 / μl, and 1,000 or more toner particles are measured. After the measurement, using this data, the equivalent circle diameter and circularity frequency distribution of the toner are obtained.

Examples of the wax component usable in the present invention include petroleum waxes such as paraffin wax, microcrystalline wax and petrolactam and derivatives thereof, montan wax and derivatives thereof,
Fischer-Tropsch hydrocarbon waxes and derivatives thereof, polyolefin waxes and derivatives thereof represented by polyethylene, natural waxes such as carnauba wax, candelilla wax and derivatives thereof, and the like. Derivatives include oxides and vinyl monomers. And a graft-modified product. In addition, alcohols such as higher aliphatic alcohols; fatty acids such as stearic acid and palmitic acid or compounds thereof; acid amides, esters, ketones, hydrogenated castor oil and derivatives thereof, vegetable waxes, and animal waxes. These can be used alone or in combination.

Among these, when polyolefin, hydrocarbon wax, petroleum wax, higher alcohol or higher ester obtained by Fischer-Tropsch method is used, the effect of improving developability and transferability is further enhanced. Note that an antioxidant may be added to these wax components as long as the chargeability of the toner is not affected. Further, these wax components are used as binder resin 100.
It is preferable to use 1 to 30 parts by mass with respect to parts by mass.

The wax component according to the present invention can be used in observation of a tomographic plane of a toner using a transmission electron microscope (TEM).
In a state where the wax component is not compatible with the binder resin, the wax component is dispersed in a substantially spherical and / or spindle-shaped island shape.

In the present invention, the dispersion state of the wax component as described above is defined as follows. In other words, the circle-equivalent weight average diameter D means the average value of the weight-based particle size frequency distribution of the toner measured by the above-mentioned flow type particle image measuring apparatus.
₄ (μm), D ₄ × 0.9 or more, and D ₄ × 1.
20 tomographic planes of toner having a major axis of 1 or less are selected. Then, the major axis R of the tomographic plane of each selected toner,
Among the phase separation structures caused by the wax component existing in the tomographic plane of the toner having the major diameter R, the largest major axis r is measured, and the arithmetic mean value of r / R (r / R) _st is _calculated . Ask. The arithmetic mean value (r / R) _{st of the} obtained r / R is 0.0
When the wax component is in a dispersion state satisfying 5 ≦ (r / R) _st ≦ 0.95, the wax component has a substantially spherical and / or spindle-shaped island dispersion state in a state in which the wax component is not compatible with the binder resin. It is assumed that

The arithmetic mean value of the above r / R (r / R)
_st is, by dispersing the wax component so as to satisfy the _{0.05 ≦ (r / R) st} ≦ 0.95, it is possible to localize oxycarboxylic acid efficiently toner surface, the toner charge Can contribute to stabilization of sex.
Further, since the wax component is included in the toner particles, deterioration of the toner surface and contamination of the image forming apparatus can be prevented, so that the effect of fixing the oxycarboxylic acid near the toner particle surface is maintained. be able to. Furthermore, the arithmetic mean value of r / R (r / R) _st is 0.25 ≦
(R / R) In a dispersion state satisfying _st ≦ 0.90,
It is preferable because good chargeability can be maintained and a toner image excellent in dot reproduction can be formed for a long period of time. Further, at the time of heating, the wax component efficiently acts on the heating and pressurizing means as described above, so that the oxidizing ability and the surfactant-like behavior of the oxycarboxylic acid contained in the toner are suppressed, and the heating and pressurizing means is suppressed. And the low-temperature fixability and the offset resistance are also good.

As a method for observing the tomographic plane of the toner,
An electron dyeing method that uses the difference in the microstructure between the crystalline phase and the amorphous phase of the wax component to be used and the binder resin that forms the outer periphery to increase the electron density of one component with heavy metal to give a contrast between the materials. It is preferable to use Specifically, after sufficiently dispersing the toner particles in a room temperature curable epoxy resin, the toner particles are cured for 2 days at an ambient temperature of 40 ° C., and the obtained cured product is ruthenium tetroxide (Ru).
O ₄ ) and, if necessary, osmium tetroxide (OsO ₄ )
And then performing electron staining, a flaky sample is cut out using an ultramicrotome equipped with a diamond knife, and the sectional layer morphology of the toner is observed using a transmission electron microscope (TEM).

A typical example is shown in FIGS. 5A and 5B. In the toner particles obtained in Examples described later, it was observed that the wax component was included in the binder resin.

The wax component used in the present invention has a main endothermic peak temperature (melting point) of 3 in a DSC curve measured according to “ASTM D3418-82”.
Compounds in the range 0-120 ° C, more preferably 40-90 ° C, are preferred.

By using the wax component having the above-mentioned thermal characteristics, not only good fixability of the obtained toner but also a releasing effect by the wax component is efficiently exhibited, and a sufficient fixing area is secured. In addition, it is possible to eliminate the adverse effects on the image forming apparatus and the developing property and blocking resistance due to the conventionally known wax component. In particular, since the specific surface area of the toner decreases as the particle shape of the toner becomes spherical, it is very effective to control the thermal characteristics and the dispersion state of the wax component.

For measurement of the main endothermic peak temperature (melting point) of the wax component, for example, "DSC-7" (manufactured by PerkinElmer) is used. The melting point of iridium and zinc is used for the temperature correction of the device detection unit, and the heat of fusion of iridium is used for the correction of the calorific value. At the time of measurement, a sample in an aluminum pan and a sample only in an aluminum pan (empty pan) were set for comparison, and
The main endothermic peak temperature (melting point) is obtained from a DSC curve obtained when the temperature of the measurement region at 180 ° C. is raised at a temperature rising rate of 10 ° C./min. When only the wax component is measured, the measurement is started after the temperature is raised and lowered under the same conditions as the measurement and the previous history is removed. When the wax component contained in the toner is measured, the measurement is performed as it is without performing the operation of removing the previous history.

Further, the wax component used in the present invention has a number average molecular weight (Mn) in the molecular weight distribution measured by gel permeation chromatography (GPC).
Is 200 to 2000, and the weight average molecular weight (Mw) is 400
It is preferable to use those having a Mw / Mn of 3.0 or less and 3.0 or less. When the number average molecular weight of the wax component is less than 200 or the weight average molecular weight is less than 400, the ratio of the low molecular weight component increases, and as a result, there is a problem in the chargeability of the toner and the matching with the image forming apparatus, which is not preferable. . When the number average molecular weight of the wax component exceeds 2,000, or when the weight average molecular weight is 3
If it exceeds 000, it becomes difficult to appropriately smooth the surface of the fixed image, which is not preferable from the viewpoint of lowering the color mixing. In addition, when toner particles are obtained by a polymerization method, since granulation and polymerization are performed in an aqueous dispersion medium, a wax component is mainly deposited during granulation, which is not preferable. In the present invention, the molecular weight distribution of the wax component is measured under the following conditions.

<GPC Measurement Conditions> Apparatus: GPC-150C (manufactured by Waters) Column: GMH-HT (manufactured by Tosoh Corporation) Duplex temperature: 135 ° C. Solvent: o-dichlorobenzene (addition of 0.1% ionol) Flow rate : 1.0 ml / min sample: 0.4 ml of 0.15 wt% sample was injected

The molecular weight of the sample was measured under the above conditions. The molecular weight of the sample was calculated using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample and converted to polyethylene by a conversion formula derived from the Mark-Houwink viscosity formula.

Examples of the binder resin for the toner used in the present invention include commonly used styrene- (meth) acrylic copolymers, polyester resins, epoxy resins, and styrene-butadiene copolymers. In a method of directly obtaining toner particles by a polymerization method, a monomer for forming them is used. Specifically, styrene; o
Styrene monomers such as-(m-, p-) methylstyrene and m- (p-) ethylstyrene; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (meth) ) Butyl acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth)
(Meth) acrylate monomers such as dimethylaminoethyl acrylate and diethylaminoethyl (meth) acrylate; ene monomers such as butadiene, isoprene, cyclohexene, (meth) acrylonitrile, and acrylamide are preferably used. Can be These can be used alone or generally in the published Polymer Handbook, 2nd Edition, III-P 139-192 (John Wiley).
& Sons Corporation) theoretical glass transition temperature (Tg)
However, it is used by appropriately mixing monomers so as to show a temperature of 40 to 75 ° C. If the theoretical glass transition temperature is lower than 40 ° C., problems tend to occur in terms of the storage stability and durability stability of the toner, while if it exceeds 75 ° C., the fixing point of the toner increases.

Further, in the present invention, it is preferable to use a crosslinking agent at the time of synthesizing the binder resin in order to increase the mechanical strength of the toner particles.

As the crosslinking agent used in the toner according to the present invention, divinyl benzene, bis (4-acryloxypolyethoxyphenyl) propane, ethylene glycol diacrylate, 1,3-butylene glycol Acrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate ,
Polyethylene glycol # 200, # 400, # 600
Each diacrylate, dipropylene glycol diacrylate, polypropylene glycol diacrylate,
Examples include polyester-type diacrylate (MANDA Nippon Kayaku) and those obtained by replacing the above diacrylate with methacrylate.

Examples of polyfunctional crosslinking agents include pentaerythritol triacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, oligoester acrylate and its methacrylate, 2,2
Examples include 2-bis (4-methacryloxy, polyethoxyphenyl) propane, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate and triallyl trimellitate.

These cross-linking agents can be used in combination with other vinyl monomers 1
The amount is preferably 0.05 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, based on 00 parts by mass.

In the present invention, a resin having polarity (hereinafter, referred to as “polar resin”) such as a polyester resin or a polycarbonate resin can be used together with the above-mentioned binder resin. By adding a polar resin to the toner,
It becomes easy to control the content of the oxycarboxylic acid in the toner to the specific state as described above.

For example, when a toner is directly produced by a suspension polymerization method or the like to be described later, when the above-mentioned polar resin is added during the polymerization reaction from the dispersion step to the polymerization step, the polymerizable monomer which becomes the toner particles is formed. Depending on the balance between the polarity of the composition and the aqueous dispersion medium, it is possible to control the added polar resin to form a thin layer on the surface of the toner particles or to exist with a gradient from the surface of the toner particles toward the center. it can. At this time, the presence of the oxycarboxylic acid in the toner can be changed to a desirable form by using a polar resin having an interaction of the oxycarboxylic acid. In particular, when a polar resin having an acid value of 1 to 20 mgKOH / g is used, it is easy to control the state of the oxycarboxylic acid.

The amount of the polar resin added is 100
It is preferable to use 1 to 25 parts by mass with respect to parts by mass,
More preferably, it is 2 to 15 parts by mass. If the amount is less than 1 part by mass, the existence state of the polar resin in the toner particles becomes non-uniform. If the amount exceeds 25 parts by mass, the thin layer of the polar resin formed on the surface of the toner particles becomes thick. It becomes difficult to control the content of the carboxylic acid, and the function cannot be sufficiently exhibited.

The composition of a typical polyester resin used as such a polar resin is as follows.

As the alcohol component of the polyester resin, 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-
Examples thereof include ethyl 1,3-hexanediol, hydrogenated bisphenol A, bisphenol derivatives represented by the following formula (A), and diols represented by the following formula (A).

[0136]

Embedded image

[0137]

Embedded image

The use of a reactive polyester resin or a polycarbonate resin as the polar resin is also a preferred embodiment of the present invention. When these polar resins are used, the charging characteristics of the toner are improved, image fogging and scattering are improved, and a high-quality image having excellent dot reproducibility can be obtained. In addition, it is possible to impart appropriate mechanical strength to the toner particles, minimize the effect of toner deterioration received from the image forming apparatus, and improve durability against multiple printouts and matching with an image forming apparatus described later. improves. Further, it is possible to minimize the influence of a toner manufacturing process such as a toner sphering process for achieving the toner shape distribution as described above and a drying process when directly manufacturing a toner by a polymerization method. Also,
Two or more polar resins can be used in combination, and the chargeability of the polar resin itself can be used.

The reactive polyester according to the present invention includes terephthalic acid, isophthalic acid, phthalic acid, adipic acid, maleic acid, succinic acid, sebacic acid, thiodiglycolic acid, diglycolic acid, malonic acid, glutanic acid, pimerine Acids, suberic acid, azelaic acid, succinic acid, cyclohexanedicarboxylic acid, polybasic acids such as trimellitic acid; and ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol,
1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-bis (hydroxymethyl) cyclohexane, 1,4-bis (2-hydroxyethyl) benzene, 1,4-cyclohexanedimethanol, Polyethylene glycol, polypropylene glycol, bisphenol A, hydrogenated bisphenol,
Ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, glycerin, trimethylolpropane, polycondensation with polyhydric alcohols such as pentaerythritol, the main chain of the obtained condensation polymer or It has a reactive group in the side chain. The reactive group is a carboxylic acid (or a salt thereof),
Examples thereof include sulfonic acid (or a salt thereof), ethyleneimino acid, epoxy group, isocyanate group, double bond, acid anhydride, halogen atom, and the like. Reacting with a functional crosslinking agent (eg, polyhydric alcohol, polybasic acid, etc.) and further reacting the reactive polyester with a vinyl monomer (eg, esterification, copolymerization, etc.) to obtain a THF-insoluble component Can be. For example, when a toner is obtained by a polymerization method, an unsaturated polyester resin is used as a reactive polyester resin, and a vinyl monomer (including a crosslinking agent such as divinylbenzene as necessary) is copolymerized.
In this case, the unsaturated polyester resin having polarity migrates to the vicinity of the toner surface with the progress of polymerization and forms a thin layer on the surface of the toner particles, so that a toner having particularly excellent blocking resistance and offset resistance is obtained. It is possible to get.

As the reactive polyester resin that can be used in the present invention, any resin may be used as long as it contains a reactive group as described above. However, if the Tg is too low, a polyester resin which does not participate in the crosslinking reaction may be used. When present on the toner surface, the blocking resistance and the offset resistance may be reduced. Further, if the Tg is too high, for example, when a toner is obtained by a polymerization method, it becomes difficult to dissolve the reactive polyester resin in a vinyl-based monomer.
Manufacturing becomes difficult. Therefore, the Tg of the reactive polyester resin is preferably about 40 to 80 ° C. for obtaining a toner having particularly excellent performance.

On the other hand, as the polycarbonate resin according to the present invention, a polycarbonate resin having a repeating unit represented by the following general formula (I) in its molecular structure is preferably used.

[0142]

Embedded image [Wherein, R represents an organic group. ]

The above-mentioned general formula (I) has various structures. For example, any known polycarbonate produced by reacting a dihydric phenol with a carbonate precursor by a solution method or a melting method may be used. The following general formula (II) can be mentioned as an example.

[0144]

Embedded image [In the formula, R ² is a hydrogen atom, an aliphatic hydrocarbon group, or an aromatic substituent. When a plurality of R ² are present, they may be the same or different, and m is , 0-4. Z is a single bond, an aliphatic hydrocarbon group, an aromatic substituent, -S -, - SO -, - SO 2 -, - O -, - CO
-Represents a bond represented by a bond. A polymer having a repeating unit having a structure represented by the following formula:

Although various polycarbonate resins can be used, the polycarbonate resins generally have the following general formulas (III) to (III):
(V)

[0146]

Embedded image

[0147]

Embedded image

[0148]

Embedded image Wherein R ² , m and Z are the same as above. And a carbonate precursor such as phosgene or a carbonate compound. That is, for example, by reacting a dihydric phenol with a carbonate precursor such as phosgene in a solvent such as methylene chloride in the presence of a known acid acceptor or a molecular weight regulator, or as in the case of dihydric phenol and diphenyl carbonate. It is produced by a transesterification reaction with a suitable carbonate precursor.

There are various dihydric phenols represented by the general formulas (III) to (V).
In addition to bis (4-hydroxyphenyl) propane [commonly known as bisphenol A], for example, bis (4-hydroxyphenyl) methane; bis (4-hydroxyphenyl)
Phenylmethane; bis (4-hydroxyphenyl) naphthylmethane; bis (4-hydroxyphenyl)-(4-
Isopropylphenyl) methane; bis (3,5-dimethyl-4-hydroxyphenyl) methane; 1,1-bis (4-hydroxyphenyl) ethane; 1-naphthyl-
1,1-bis (4-hydroxyphenyl) ethane; 1-
Phenyl-1,1-bis (4-hydroxyphenyl) ethane; 1,2-bis (4-hydroxyphenyl) ethane; 2-methyl-1,1-bis (4-hydroxyphenyl) propane; 2,2-bis (3,5-dimethyl-4-
(Hydroxyphenyl) propane; 1-ethyl-1,1-
Bis (4-hydroxyphenyl) propane; 2,2-bis (3-methyl-4-hydroxyphenyl) propane;
1,1-bis (4-hydroxyphenyl) butane; 2,
2-bis (4-hydroxyphenyl) butane; 1,4-
Bis (4-hydroxyphenyl) butane; 2,2-bis (4-hydroxyphenyl) pentane; 4-methyl-
2,2-bis (4-hydroxyphenyl) pentane;
1,1-bis (4-hydroxyphenyl) cyclohexane; 2,2-bis (4-hydroxyphenyl) hexane; 4,4-bis (4-hydroxyphenyl) heptane; 2,2-bis (4-hydroxyphenyl) Nonan;
1,10-bis (4-hydroxyphenyl) decane;
Dihydroxyarylalkanes such as 1,1-bis (4-hydroxyphenyl) cyclodecane; bis (4-hydroxyphenyl) sulfone; dihydroxyarylsulfones such as bis (3,5-dimethyl-4-hydroxyphenyl) sulfone; bis (4-hydroxyphenyl) ether; dihydroxyaryl ethers such as bis (3,5-dimethyl-4-hydroxyphenyl) ether; 4,4′-dihydroxybenzophenone;
Dihydroxyarylketones such as 3 ′, 5,5′-tetramethyl-4,4′-dihydroxybenzophenone, bis (4-hydroxyphenyl) sulfide; bis (3-methyl-4-hydroxyphenylsulfide; bis (3 Dihydroxyaryl sulfides such as 5-dimethyl-4-hydroxyphenyl) sulfide, dihydroxyaryl sulfoxides such as bis (4-hydroxyphenyl) sulfoxide, dihydroxy diphenyls such as 4,4′-dihydroxydiphenyl, hydroquinone; solcinol; Dihydroxybenzenes such as methylhydroquinone, 1,5-dihydroxynaphthalene;
And dihydroxynaphthalenes such as 2,6-dihydroxynaphthalene. These dihydric phenols may be used alone or in combination of two or more.

Examples of the carbonate compound include diaryl carbonates such as diphenyl carbonate and dialkyl carbonates such as dimethyl carbonate and diethyl carbonate.

The polycarbonate resin used in the present invention may be a homopolymer using one of these dihydric phenols, a copolymer using two or more of these dihydric phenols, or It may be a blend. Further, it may be a thermoplastic random branched polycarbonate resin obtained by reacting a polyfunctional aromatic compound with the above-mentioned dihydric phenol and / or carbonate precursor.

In order to adjust the glass transition temperature and the viscoelasticity of the polycarbonate resin, a part of the dihydric phenol is replaced with ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol,
1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-bis (hydroxymethyl) cyclohexane, 1,4-bis (2-hydroxyethyl) benzene, 1,4-cyclohexanedimethanol, Modification of polyethylene glycol, propylene glycol, hydrogenated bisphenol A and derivatives thereof, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, glycerin, trimethylolpropane, polyhydric alcohols such as pentaerythritol, etc. Polycarbonate resins are also preferably used. In this case, it is possible to produce by the above-mentioned method by simply substituting a part of the dihydric phenol, but as an example of another production method, dihydric phenol and aliphatic or aromatic bischloroformate And the like are reacted in a methylene chloride solvent using pyridine as a catalyst. Of course, synthesis by other production methods is also possible.

Further, in the present invention, as the polycarbonate resin, the above-mentioned polycarbonate and polystyrene, styrene- (meth) acrylic copolymer, polyester, polyurethane, epoxy resin, polyolefin,
Use of block copolymers with polyamides, polysulfones, polycyanoaryl ethers, polyarylene sulfides, etc. and graft-modified copolymers grafted with alkyl (meth) acrylate, (meth) acrylic acid, maleic acid, styrene-based monomers, etc. It is possible.

The molecular weight of the polycarbonate resin used in the present invention is not particularly limited, but those having a peak molecular weight measured by GPC in the range of 1,000 to 500,000 are preferable, and more preferably 2,000 to 50,000.
100,000. If the peak molecular weight is lower than 1,000, the charging characteristics may be adversely affected, and
If it is higher than this, the melt viscosity becomes too high, which may cause a problem in fixability. In producing the polycarbonate resin used in the present invention, a suitable molecular weight regulator, a branching agent for improving viscoelasticity, a catalyst for accelerating the reaction, and the like can be used as required.

Further, the polar resins as described above are not limited to one kind of polymer, respectively. For example, two or more kinds of reactive polyester resins may be used at the same time, and two or more kinds of vinyl polymers may be used. Possible and even completely different polymers, such as non-reactive polyester resin, epoxy resin, polycarbonate resin, polyolefin, polyvinyl acetate, polyvinyl chloride, polyalkyl vinyl ether, polyalkyl vinyl ketone,
Various polymers such as polystyrene, poly (meth) acrylic ester, melamine formaldehyde resin, polyethylene terephthalate, nylon, and polyurethane can be added to the binder resin as needed.

In general, the thin layer formed on the surface of the toner particles by the polar resin as described above is obtained by observing the tomographic plane of the toner particles using a transmission electron microscope (TEM) as described above, by using ruthenium tetroxide (RuO). ₄ ) and / or by electronic staining with osmium tetroxide (OsO ₄ ). At this time, the binder resin and the wax component are present in the thin layer formed on the surface of the toner particles in the direction toward the inside of the toner, and the wax component is substantially spherical and / or spindle-shaped island-shaped in the binder resin. Are simultaneously observed. Representative examples are shown in FIGS. 5 (c) and 5 (d).
A state in which the thin layer substantially uniformly covers the surface of the toner particles as shown in FIG. 5C is defined as a continuous layer.
A state in which the thin layer partially covers the surface of the toner particles as in (d) is defined as a discontinuous layer.

The coloring agents used in the present invention include the following yellow coloring agents, magenta coloring agents and cyan coloring agents. As black coloring agents, carbon black, magnetic materials or the following yellow coloring agents / magenta coloring agents / A mixture of a cyan colorant and a black color is used.

The carbon black used in the present invention preferably has a BET specific surface area of 15 to 300 m ² / g by nitrogen gas.

Regarding the BET specific surface area of the carbon black, if it is larger than 300 m ² / g, the primary particle diameter is fine, so that it is difficult to obtain a sufficient dispersion and it is difficult to make full use of the carbon black.

When the value is smaller than 15 m ² / g,
Even if the toner is well dispersed, there arises inconvenience that only a low-density image is obtained or toner consumption increases due to insufficient coloring power as a toner.

Regarding the BET specific surface area of the carbon black, the BET specific surface area is more preferably ²⁰ to 100 m ² / g, and the charge polarity and charge amount of the transfer residual toner by the charging member can be controlled more reliably and uniformly. Made
This is more advantageous in terms of the stability of the charge amount of the toner and the toner coloring power.

The measurement of the BET specific surface area of carbon black is performed according to “ASTM D3037-78”.

The D of the carbon black used in the present invention
The BP oil absorption is desirably 40 to 150 ml / 100 g.

When the DBP oil absorption is less than 40 ml / 100 g, carbon black having a short structure tends to have too low a charge amount of the toner. When it exceeds 150 ml / 100 g, fine dispersion of carbon black is difficult to obtain due to a strong long structure. .

The measurement of the DBP oil absorption was performed according to “ASTM D2
414-79 ".

As the yellow colorant used in the present invention, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds and allylamide compounds are used. Specifically, for example, C.I. I. Pigment Yellow 12, 1
3, 14, 15, 17, 62, 74, 83, 93, 9
4, 95, 97, 109, 110, 111, 120, 1,
27, 128, 129, 147, 168, 174, 17
6, 180, 181, 191 and the like are preferably used.

The magenta colorant used in the present invention includes condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds,
Thioindigo compounds and perylene compounds are used. Specifically, for example, C.I. I. Pigment Red 2, 3,
5, 6, 7, 23, 48: 2, 48: 3, 48: 4,5
7: 1, 81: 1, 144, 146, 166, 169,
177, 184, 185, 202, 206, 220, 2
It is particularly preferable to use 21, 254 or the like.

As the cyan colorant used in the present invention, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds and the like can be used.
Specifically, for example, C.I. I. Pigment Blue 1,
7, 15, 15: 1, 15: 2, 15: 3, 15: 4,
60, 62, 66, etc. are particularly preferred.

These coloring agents can be used alone or as a mixture, and can also be used in the form of a solid solution. When a magnetic material is used as the colorant, the amount of the colorant to be contained in the toner is preferably 40 to 150 parts by mass with respect to 100 parts by mass of the binder resin. When an agent is used, it is preferable to use 5 to 20 parts by mass based on 100 parts by mass of the polymerizable vinyl monomer.

In the present invention, a magnetic toner can be obtained by incorporating a magnetic material. In this case, the magnetic material can also serve as a colorant. Examples of the magnetic substance usable in the present invention include iron oxides such as magnetite, hematite, and ferrite; metals such as iron, cobalt, and nickel; or these metals, and aluminum, cobalt, copper, lead, magnesium, tin, and zinc. , Antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium and other metals and mixtures thereof.

Furthermore, as these magnetic materials used in the present invention, more preferably, surface-modified magnetic materials are used. In particular, when a toner is produced by a polymerization method, it is preferable to use a toner which has been subjected to a hydrophobic treatment with a surface modifier having no polymerization inhibition. Examples of such a surface modifier include a silane coupling agent and a titanium coupling agent.

Further, as these magnetic materials, those having an average particle diameter of 1 μm or less, preferably 0.1 to 1 μm may be used. As a magnetic material, 795.8 kA / m (10
The coercive force (H
_C ) is 1.59 to 23.9 Am ² / g (20 to 300
Oersted), saturation magnetization (σ _s ) is 50-200A
It is preferable to use those having m ² / g and residual magnetization (σ _r ) of 2 to 20 Am ² / g.

In the present invention, a known charge control agent can be used in combination with the above-mentioned oxycarboxylic acid. In particular, a charge control agent which has a high charging speed and can stably maintain a constant charge amount is preferable. Further, when a direct polymerization method is used for toner particles, a charge control agent having no polymerization inhibition and having no solubilized substance in an aqueous dispersion medium is preferable. Specific compounds include metal compounds of carboxylic acids such as salicylic acid, naphthoic acid and dicarboxylic acid as negative charge control agents;
Polymer type compounds having a sulfonic acid or carboxylic acid group in the side chain; boron compounds; urea compounds; silicon compounds; Examples of the positive charge control agent include a quaternary ammonium salt; a polymer compound having the quaternary ammonium salt in a side chain; a guanidine compound; and an imidazole compound.

However, in the present invention, the addition of a charge controlling agent is not essential. When a two-component developing method is used, frictional charging with a carrier is used, and a non-magnetic one-component blade coating developing method is used. In such a case, it is not always necessary to include a charge control agent in the toner particles by positively utilizing the triboelectric charging between the blade member and the sleeve member.

The addition of an inorganic fine powder to the toner according to the present invention is a preferred embodiment for improving developability, transferability, charging stability, fluidity and durability. As the inorganic fine powder, known ones can be used, and it is particularly preferable to be selected from silica, alumina, titania or a double oxide thereof. Further, silica is more preferable. For example, as the silica, both a so-called dry method produced by vapor phase oxidation of a silicon halide and an alkoxide, and a so-called wet silica produced from an alkoxide, a water glass and the like, and a dry silica called a fumed silica can be used. However, there are few silanol groups on the surface and inside the silica fine powder.
Dry silica with less production residue such as ₂ O and SO ₃ ^2- is more preferable. In the case of fumed silica, it is also possible to obtain a composite fine powder of silica and another metal oxide by using another metal halide such as aluminum chloride and titanium chloride together with a silicon halide in the manufacturing process. Is also included.

The inorganic fine powder used in the present invention is BET.
The specific surface area by measuring nitrogen adsorption 30 m ² / g or more by law, in particular 50 to 400 m ² / g give good results in the range of, used 0.3 to 8 parts by mass with respect to 100 mass parts of the toner , Preferably 0.5 to 5 parts by mass.

By coexisting the above-mentioned inorganic fine powder having a controlled specific surface area with the oxycarboxylic acid present near the toner surface, the amount of water adsorbed on the toner particles is controlled, and the triboelectric charge and the charge speed are reduced. The control effect increases.
Further, image defects due to contamination of the toner carrier and the like by oxycarboxylic acid are prevented beforehand. Further, since the toner has an appropriate fluidity, the uniform chargeability of the toner is synergistically improved, and the above-described excellent effect is maintained even when a large number of printouts are continuously performed.

When the specific surface area is less than 30 m ² / g,
It is difficult to impart appropriate fluidity to the toner, and the effect of preventing contamination of the toner carrier caused by oxycarboxylic acid is reduced. Specific surface area is 400m
If it exceeds ² / g, the fluidity of the toner may decrease because the inorganic fine powder is embedded in the surface of the toner particles during continuous printing.

When the addition amount of the inorganic fine powder is less than 0.3 parts by mass, the effect of addition is not exhibited, and when it exceeds 8 parts by mass, there arises a problem in chargeability and fixability of the toner. In addition, the loose inorganic fine powder significantly deteriorates the matching with the image forming apparatus.

The inorganic fine powder used in the present invention includes:
Silicon varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, silane coupling agents, silane coupling agents having functional groups, other organosilicon compounds, organic It is possible and preferable to use a treating agent such as a titanium compound or a combination of various treating agents.

The specific surface area was measured by using a specific surface area measuring apparatus “Autosorb 1” (manufactured by Yuasa Ionics) to adsorb nitrogen gas on the sample surface and calculating the specific surface area by the BET multipoint method.

In order to maintain a high charge amount and achieve a low consumption and a high transfer rate, it is more preferable that the inorganic fine powder is treated with at least silicone oil.

In the toner according to the present invention, other additives such as lubricant powders such as Teflon powder, zinc stearate powder, polyvinylidene fluoride powder, cerium oxide powder, Abrasives such as silicon powder and strontium titanate powder; fluidity-imparting agents such as titanium oxide powder and aluminum oxide powder; anti-caking agents; or conductivity-imparting agents such as carbon black powder, zinc oxide powder and tin oxide powder Further, organic fine particles and inorganic fine particles of opposite polarity can be used in a small amount as a developing property improver.

The toner according to the present invention can be used as it is as a one-component developer or as a two-component developer by mixing with a carrier.

When used as a two-component developer, for example, magnetic carriers to be mixed with toner include iron and iron.
It is composed of an element selected from copper, zinc, nickel, cobalt, manganese, chromium and the like, alone or in a composite ferrite state. The shape of the magnetic carrier used at this time includes a spherical shape, a flat shape, an irregular shape, and the like, and a shape in which the fine structure (for example, surface unevenness) of the surface state of the magnetic carrier is appropriately controlled may be used. it can. Also, a resin-coated carrier whose surface is coated with a resin can be suitably used. The average particle size of the carrier used is preferably 10 to
It is 100 μm, more preferably 20 to 50 μm. When the carrier and the toner are mixed to prepare a two-component developer, the toner concentration in the developer is preferably about 2 to 15% by weight.

In the method for producing the toner according to the present invention, a binder resin, a colorant, a wax component, etc. are melt-kneaded by a pressure kneader or the like, and then the cooled kneaded product is pulverized to a desired toner particle size. And a pulverization method in which a finely pulverized product is classified to adjust the particle size distribution to obtain a toner;
JP, JP-A-59-53856 and JP-A-59-53856
A method for producing a toner directly by using a suspension polymerization method described in JP-B-61842;
A method of producing a spherical toner by atomizing a melt-kneaded product into the air using a disk or a multi-fluid nozzle described in Japanese Patent Application Laid-Open No. H10-208, and a known method such as an emulsion polymerization method represented by a soap-free polymerization method. Although it is possible, it is preferable to manufacture a toner in which the content of oxycarboxylic acid is specified by a suspension polymerization method while controlling the pH of the aqueous dispersion medium during the polymerization reaction of the polymerizable vinyl monomer. .

The oxycarboxylic acid added to the toner for the purpose of controlling the triboelectric charge and the charging speed has a large number of hydrophilic functional groups. When polymerizing the granulated particles of the composition to form toner particles, the oxycarboxylic acid is eluted into the aqueous medium. When the oxycarboxylic acid is eluted, the obtained toner particles do not sufficiently exhibit the effect of improving the charge amount and the charge speed. In addition, since the eluted oxycarboxylic acid acts as a surfactant, it is very difficult to maintain the shape of the toner particles in the polymerization step, and the toner cannot be controlled to a desired particle size distribution or spherical distribution. In particular, when the amount of oxycarboxylic acid eluted is large, particles having a finer particle diameter than the toner particles are produced as by-products, which hinders matching with the image forming apparatus.

On the other hand, the present inventors prevented the dissolution of oxycarboxylic acid by controlling the polymerization conversion rate of the polymerizable vinyl monomer and the pH in the aqueous dispersion medium,
It has been found that oxycarboxylic acid can be immobilized in a good condition near the surface of the toner.

That is, in the polymerization reaction of the polymerizable monomer composition from the granulation step to the polymerization step, the pH in the aqueous dispersion medium was adjusted to 4% until the polymerization conversion of the polymerizable vinyl monomer became 10% or more. 0.5 to 8.5.

Thus, elution of the oxycarboxylic acid is prevented, and the oxycarboxylic acid is encapsulated in the toner particles. Further, after the pH in the aqueous dispersion medium is readjusted to 9 to 13, the polymerization conversion rate is further increased to draw out the oxycarboxylic acid encapsulated in the toner to the vicinity of the surface of the toner particles which can participate in triboelectric charging. At the same time, the oxycarboxylic acid present on the surface can be dissolved and removed under an alkaline atmosphere.

As a result, the oxycarboxylic acid can be immobilized in the vicinity of the surface of the toner particles in a good state, and the toner obtained has very good charging characteristics. Further, since the particle size distribution and the shape distribution of the toner particles can be controlled to desired ones without inducing by-products of fine particle size, the charging characteristics are synergistically improved and the image forming apparatus is improved. Very good matching can be achieved. In particular, by carrying out the polymerization reaction of the polymerizable vinyl monomer while maintaining the pH in the aqueous medium at 4.5 to 6.0, the encapsulating property of the oxycarboxylic acid is further enhanced, so that the above-mentioned improvement effect is further enhanced. It will be good.

Further, when producing the toner according to the present invention, the pH in the aqueous dispersion medium is adjusted so that the oxycarboxylic acid amount A and the oxycarboxylic acid amount B satisfy the above relationship.
The polymerization conversion of the polymerizable vinyl monomer in the polymerizable monomer composition when the pH is changed in the aqueous dispersion medium is appropriately adjusted.

In the present invention, the “polymerization conversion” of the polymerizable vinyl monomer refers to the total mass (W ₁ ) of the polymerizable vinyl monomer used in the polymerizable monomer composition. Based on the total mass of unreacted polymerizable vinyl monomers (W
_It can be obtained from the following equation by quantifying ₂ ).

[0194]

(Equation 5)

The unreacted polymerizable vinyl monomer is
Immediately after sampling from the reaction vessel, a polymerization terminator or cold methanol is added to the collected sample to stop the polymerization reaction. ・ Using thermogravimetry (TG), which is measured as a mass loss upon heating using a thermobalance or the like The method can be quantified by applying a known method such as a method using gas chromatography (GC). Among these, the method using GC is useful.

In the present invention, the amount of the unreacted polymerizable vinyl monomer is determined under the following conditions.

<GC measurement conditions> Apparatus: GC-14A (manufactured by Shimadzu Corporation) Column: fused silica capillary column (J & W SC)
Manufactured by IENTIFC; size: 30m x 0.249m
m, liquid phase: DBWAX, film thickness: 0.25 μm) Sample: 2.55 mg of DMF as an internal standard
Add 0 ml of acetone to make a solvent containing the internal standard. Next, 400 mg of the toner is made into a 10 ml solution with the above solvent. After 30 minutes on an ultrasonic shaker, leave for 1 hour. Next, the mixture is filtered with a 0.5 μm filter. The volume of the implanted sample is 4 μl. Detector: FID (split ratio: 1:20) Carrier gas: N ₂ gas Oven temperature: 70 ° C. → 220 ° C. (After waiting at 70 ° C. for 2 minutes, the temperature is raised at a rate of 5 ° C./min.) Inlet temperature: 200 ° C. Detector temperature: 200 ° C. Calibration curve preparation: A DMF similar to the sample solution, a gas chromatographic measurement of a standard sample obtained by adding a target polymerizable vinyl monomer to an acetone solution, and a polymerizable vinyl The mass ratio / area ratio between the monomer and the internal standard DMF is determined.

In the method for producing a toner according to the present invention,
As the dispersant used for preparing the aqueous dispersion medium, known inorganic and organic dispersants can be used. Specifically, as the inorganic dispersant, for example,
Tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, magnesium carbonate, calcium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, alumina And the like. Further, as an organic dispersant, for example, polyvinyl alcohol, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose,
Starch or the like can be used.

It is also possible to use commercially available nonionic, anionic or cationic surfactants. For example, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, calcium oleate, and the like can be used.

In the method for producing a toner according to the present invention, a poorly water-soluble inorganic dispersant is preferable, and a poorly water-soluble inorganic dispersant which is soluble in an acid is preferably used. Further, in the present invention, when a water-based dispersion medium is prepared using a poorly water-soluble inorganic dispersant, these dispersants are used in an amount of 0.2 to 2. 0
It is preferable to use them in such a ratio that they become parts by mass. Further, in the present invention, it is preferable to prepare an aqueous dispersion medium by using 300 to 3,000 parts by mass of water with respect to 100 parts by mass of the polymerizable monomer composition.

In the present invention, when preparing an aqueous dispersion medium in which the above-mentioned poorly water-soluble inorganic dispersant is dispersed, the dispersion may be carried out using a commercially available dispersant as it is. In order to obtain dispersant particles having the following formula (I), a poorly water-soluble inorganic dispersant as described above may be formed in a liquid medium such as water under high-speed stirring. For example, when using tricalcium phosphate as a dispersant,
By mixing the aqueous sodium phosphate solution and the aqueous calcium chloride solution under high-speed stirring to form tricalcium phosphate fine particles, a preferable dispersant can be obtained.

According to the method for producing the toner of the present invention having the above-described structure, the amount of triboelectric charge under high humidity, which has conventionally been observed in a toner containing a charge control agent, and the low humidity In this case, it is possible to easily obtain a toner capable of suppressing a reduction in the frictional charging speed of the toner and effectively suppressing the occurrence of contamination of the toner carrier.

Next, the polymerizable monomer composition used in the method for producing a toner of the present invention will be described. The polymerizable monomer composition is at least a polymerizable vinyl monomer, a colorant, a charge control agent, and the oxycarboxylic acid described above, preferably, in addition to this, a wax component, and It is prepared by dissolving and mixing various additives accordingly.

As the polymerizable vinyl monomer used at this time, the above-mentioned polymerizable monomers are appropriately mixed and used so that the theoretical glass transition temperature (Tg) is 40 to 75 ° C. Can be In particular, when the Tg is high, when a color toner for forming a full-color image is manufactured, the color mixing property of each color toner at the time of fixing is reduced, the color reproducibility is poor, and the transparency of the OHP image is further reduced. Is not preferred.

Further, specific examples of the polymerization initiator used in the method for producing a toner according to the present invention include 2,2′-azobis- (2,4-dimethylvaleronitrile) and 2,2 ′.
-Azobisisobutyronitrile, 1,1, -azobis (cyclohexane-1-carbonitrile), 2,2'-
Azo or diazo polymerization initiators such as azobis-4-methoxy-2,4-dimethylvaleronitrile and azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichloro A peroxide-based polymerization initiator such as benzoyl peroxide and lauroyl peroxide is used. The amount of these polymerization initiators varies depending on the desired degree of polymerization, but is generally 5 to 20 parts by mass per 100 parts by mass of the polymerizable vinyl monomer. The type of the polymerization initiator varies slightly depending on the polymerization method, but is used alone or in combination with reference to the 10-hour half-life temperature.

In order to control the degree of polymerization, a known crosslinking agent, chain transfer agent, polymerization inhibitor and the like may be further added to the polymerizable monomer composition. These additives may be added to the polymerizable monomer composition in advance, or may be added as needed during the polymerization reaction.

[0207]

EXAMPLES The present invention will be described below with reference to specific examples, but the present invention is not limited to these examples.

(Production Example 1 of Toner) 700 parts by mass of ion-exchanged water and 0.1 mol / liter were placed in a two-liter four-necked flask equipped with a high-speed stirrer TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.). -na ₃ PO ₄ aqueous solution 800 parts by weight were charged, 12000 rpm rotational speed of the high-speed stirrer
And heated to 65 ° C. 1.0 mol here
An aqueous dispersion medium containing a minute hardly water-soluble dispersion stabilizer Ca ₃ (PO ₄ ) ₂ was prepared by adding 70 parts by mass of a 1 / liter-CaCl ₂ aqueous solution. Furthermore, p of aqueous dispersion medium is added with dilute hydrochloric acid.
It was re-prepared so that H became 5.0.

On the other hand, the dispersoids include: styrene monomer 77 parts by mass 2-ethylhexyl acrylate monomer 23 parts by mass divinylbenzene monomer 0.3 parts by mass Hydrophobized magnetic particles (particle size = 0) 90 parts by mass Polyester resin (weight average molecular weight = 7000) 5 parts by mass Polycarbonate resin (weight average molecular weight = 5000) 2 parts by mass Charge control agent (azo dye iron complex) 1 part by mass Acid (1-A) 0.7 parts by mass A mixture consisting of 10 parts by mass of an ester wax (melting point = 60 ° C.) is dispersed for 3 hours using an attritor (manufactured by Mitsui Kinzoku Co., Ltd.), and then 2,2′-azobis 4 parts by mass of (2,4-dimethylvaleronitrile) was added to prepare a polymerizable monomer composition.

Next, the polymerizable monomer was added to the aqueous dispersion medium.
The body composition is charged, and N at an internal temperature of 60 ° C. _TwoAtmosphere, high speed
While maintaining the rotation speed of the stirrer at 12000 rpm, 1
The mixture was stirred for 5 minutes to granulate the polymerizable monomer composition. That
After that, replace the stirring device with a paddle stirring blade,
While maintaining the same temperature while stirring at 80 rpm, a polymerizable vinyl
When the polymerization conversion of the monomer reaches 90%, the reaction is terminated.
1 mol / L aqueous solution of NaOH was added to
The pH of the dispersion medium was changed to 11. Further, the reaction temperature is 85 ° C.
And when the polymerization conversion reaches almost 100%
The polymerization reaction was completed.

After completion of the polymerization, the remaining monomer was distilled off under heating and reduced pressure, and then, after cooling, dilute hydrochloric acid was added to dissolve the poorly water-soluble dispersant. After repeating water washing several times,
Drying was performed using a conical ribbon dryer (manufactured by Okawara Seisakusho) to obtain polymer particles (A).

100 parts by mass of the above polymer particles (A) and hydrophobic
Silica fine powder (BET; 200m) ^Two/ G) 2 parts by mass
Dry-mix with a Henschel mixer (Mitsui Metals),
This was designated as Toner (A).

The amount A of oxycarboxylic acid extracted from 1 g of the toner (A) with methanol was 1.62 mg.
The amount B of oxycarboxylic acid extracted with a 0.1 mol / liter aqueous sodium hydroxide solution is 1.15 m
In g, the value of A / B was 1.41 and the value of (3/4) B + 1 was 1.86.

The average diameter of the circle-equivalent number was 5.6 μm.
The average circularity in the circularity frequency distribution was 0.980, the circularity standard deviation was 0.022, and the number of toner particles having a circularity less than 0.95 was 7.4% by number.

Further, when the tomographic plane of the toner (A) was observed by TEM, a continuous thin layer was formed on the surface of the toner particles as shown in the schematic diagram of FIG. Contains a binder resin and a wax component,
The value of (r / R) _st was 0.34.

(Toner Production Examples 2 to 5) Toner Production Example 1 except that the types and amounts of the oxycarboxylic acid and the wax component were changed and the pH conditions of the aqueous dispersion medium during the polymerization reaction were changed. After obtaining the polymer particles (B) to (E) in the same manner as in the above, toners (B) to (E) were prepared.

The types and amounts of the oxycarboxylic acid and the wax component in each of the production examples, and the toners (B) to (B)
The properties of (E) are summarized in Table 1.

(Production Examples 1 and 2 of Comparative Toner) The types and addition amounts of the oxycarboxylic acid and the wax component were changed, and the pH of the aqueous dispersion medium in the first reaction process (initial stage) and the polymerization conversion at the end of the process were changed. (Polymerization conversion rate at the time of switching the reaction course), and the pH of the aqueous dispersion medium in the second reaction course (late stage)
Comparative polymer particles (a) and (b) were obtained in the same manner as in Production Example 1 of the toner except that the above was changed, and then comparative toners (a) and (b) were prepared.

In the tomographic observation of the comparative toner (b) by TEM, formation of a thin layer on the surface of the toner particles was not confirmed, and the dispersed state of the wax component was formed as shown in the schematic diagram of FIG. 5 (b). It was substantially spherically dispersed in the resin and the (r / R) _st value was 0.02.

Table 1 shows the types and addition weights of the oxycarboxylic acid and the wax component and the conditions of the pH of the aqueous dispersion medium used in the production examples of the toner and the comparative toner, and various properties of the obtained toner. Are shown together.

[0221]

[Table 1]

Example 1 A commercially available laser beam printer L was used as an image forming apparatus.
BP-930 (manufactured by Canon Inc.) was modified and used in the following configuration.

As the fixing device, a heat roller type heating / pressing means shown in FIG. 1 was used, which was not provided with a separating claw or an offset prevention liquid applying mechanism.

The heating roller was subjected to a primer treatment with a cylindrical aluminum core bar, and then a 50 μm-thick layer was formed through an elastic layer of dimethyl silicone rubber and a primer layer.
Using a surface layer of a PFA tube,
On the other hand, the pressure roller is provided with an elastic layer of dimethyl silicone rubber after the SUS core is subjected to the primer treatment,
Further, the one provided with a surface layer by a PFA tube having a thickness of 50 μm via a primer layer was used.

Further, a halogen heater is provided as a heating element inside the cylindrical cored bar of the heating roller so that the surface temperature of the fixing roller becomes 170 ° C. when the heating and pressurizing means is operated. 2 for roller and pressure roller
A contact pressure of 45 N (25 kgf) was applied to set a nip portion having a width of 5 mm.

The toner (A) obtained in Toner Production Example 1 is charged into the process cartridge of the above-described image forming apparatus, and “recycled paper EN-1” is used as a transfer material.
00 ”(mixing ratio of recycled pulp = 100%) and FIG.
The printout image obtained when printing 100,000 sheets of a line image composed of fine lines as shown in (1) at a printout speed of 24 sheets (A4 size) / minute, The matching was evaluated.

The results of these evaluations are shown in Table 2.

Examples 2 to 5 Evaluations were made in the same manner as in Example 1 except that each of the toners (B) to (E) was used.

Table 2 summarizes the results of these evaluations.

Example 6 A roller impregnated with dimethyl silicone oil as a mechanism for applying an anti-offset liquid was brought into contact with the heating roller of the heating and pressurizing means used in Example 1 to make contact with the toner image on the transfer material. As in Example 1, except that the consumption of the offset preventing liquid applied to the contact surface was set to be 0.015 to 0.020 mg / cm ² and the toner (E) was used. evaluated.

As a result, although the obtained image was slightly glossy, improvement was found in matching with the heating and pressing means.

The results of these evaluations are shown in Table 2.

Comparative Examples 1 and 2 Evaluation was made in the same manner as in Example 1 except that each of the comparative toners (a) and (b) was used.

The results of these evaluations are shown in Table 2.

The evaluation items and the evaluation criteria described in Examples 1 to 6 and Comparative Examples 1 and 2 will be described.

[Evaluation Items] <1> Reproducibility of Fine Lines This is an evaluation relating to the image quality of a graphical image, and the reproducibility of fine lines of a printout image was evaluated. A: Good reproducibility of fine lines B: Fluctuating width of small fine lines is observed C: Fine lines and scattering are noticeable D: Fine lines are torn in places and reproducibility is poor

<2> Fixing State of Fine Line The fixing state of the thin line of the printout image was evaluated. A: A good fine line fixing state is shown. B: When the fixing surface is strongly rubbed, a part of the thin line is peeled off, or a slight dot-like toner stain is seen on a printout image. Minor offset phenomena occur in the image area. D: Fine line peeling or offset phenomena occur in some places.

<3> Matching with Heating Roller After completion of the printout test, the state of adhesion of the residual toner to the heating roller and the effect on the printout image were visually evaluated. A: No toner adhesion occurred. B: Contamination by paper dust occurred, but almost no toner adhesion was observed. C: Contamination due to paper dust and toner adhesion to the edge were observed, but fixing was observed. The effect on the image is minor. D: The printout image wraps around during the printout test.

<4> Matching with Pressure Roller After the printout test was completed, the state of adhesion of the residual toner to the pressure roller and the contamination by paper dust detached from the transfer material and the effect on the printout image were visually observed. evaluated. A: No adhesion of toner or contamination by paper dust detached from the transfer material has not occurred. B: Contamination by paper dust has occurred, but toner adhesion has hardly occurred. C: Contamination by paper dust or to the edge. Although slight toner stain is generated on the back surface of the printout image due to the fixation of the toner, there is almost no effect on the fixed image. D: There is much toner fixation and the effect on the fixed image is observed.

<5> Releasability of Pressure Roller Surface Evaluation was made based on the decrease in the contact angle of the pressure roller surface with water before and after the printout test. In other words, the lower the contact angle of the pressure roller surface in the printout test, the more the releasability was lost. When measuring the contact angle, clean the surface of the pressure roller with a solvent or the like so as not to damage it, and then use pure water to contact the contact angle meter CA.
-DS type "(manufactured by Kyowa Interface Science Co., Ltd.). A: The decrease in the contact angle is less than 5 ° B: The decrease in the contact angle is 5 ° or more and less than 7 ° C: The decrease in the contact angle is 7 ° or more and less than 10 ° D: The decrease in the contact angle is 10 ° or more

[0241]

[Table 2]

(Production Example 6 of Toner) High-speed stirrer Claire
2 liters with mix (M-Technic)
700 parts by mass of ion-exchanged water in a four-necked flask
0.1 mol / liter-Na_ThreePO_Four800 mass of aqueous solution
And the rotation speed of the high-speed stirring device is 15,000 rpm
And heated to 70 ° C. 1.0 mol here
/ Liter-CaCl _TwoAdd 70 parts by mass of aqueous solution
Small sparingly water-soluble dispersion stabilizer Ca_Three(PO_Four)_TwoWater component containing
A dispersion medium was prepared. Furthermore, p of aqueous dispersion medium is added with dilute hydrochloric acid.
It was re-prepared so that H became 5.0.

On the other hand, dispersoids include: styrene monomer 83 parts by mass n-butyl acrylate monomer 17 parts by mass divinylbenzene monomer 0.2 parts by mass carbon black (oil absorption = 75 ml / 100 g) 5 parts by weight ・ Polyester resin 3 parts by weight (condensation polymer of epoxidized bisphenol A and isophthalic acid, Tg = 70 ° C.) ・ Unsaturated polyester resin 2 parts by weight (condensation polymer of epoxidized bisphenol A and fumaric acid, Tg = 1 part by mass of charge control agent (aluminum of salicylic acid) 1 part by mass of oxycarboxylic acid (1-A) 1 part by mass of ester wax (melting point = 60 ° C.) 15 parts by mass of attritor (Mitsui Metals Co., Ltd.) For 3 hours, and 5 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) was added. A polymerizable monomer composition was prepared.

Next, the polymerizable monomer was added to the aqueous dispersion medium.
The body composition is charged, and N at an internal temperature of 60 ° C. _TwoAtmosphere, high speed
While maintaining the rotation speed of the stirrer at 15000 rpm, 1
The mixture was stirred for 5 minutes to granulate the polymerizable monomer composition. That
After that, replace the stirring device with a paddle stirring blade,
While maintaining the same temperature while stirring at 80 rpm, a polymerizable vinyl
When the polymerization conversion of the monomer reaches 85%, the reaction is terminated.
1 mol / L aqueous solution of NaOH was added to
The pH of the dispersion medium was changed to 10. Further, the reaction temperature is 80 ° C.
And when the polymerization conversion reaches almost 100%
The polymerization reaction was completed.

After the completion of the polymerization, polymer particles (F) were obtained in the same manner as in Production Example 1 of the toner.

100 parts by mass of the polymer particles (F) and 1 part by mass of hydrophobic titanium oxide fine powder (BET; 200 m ² / g) were dry-mixed with a Henschel mixer (manufactured by Mitsui Kinzoku Co., Ltd.) to obtain a toner (F). And

The amount A of oxycarboxylic acid extracted from 1 g of the toner (F) with methanol was 1.73 mg.
The amount B of oxycarboxylic acid extracted with a 0.1 mol / liter aqueous sodium hydroxide solution is 1.20 m
In g, the value of A / B was 1.44 and the value of (3/4) B + 1 was 1.90.

The circle-equivalent number average diameter was 5.2 μm.
The average circularity in the circularity frequency distribution was 0.985, the circularity standard deviation was 0.019, and the number of toner particles having a circularity less than 0.95 was 2.8% by number.

Further, when the dispersion state of the wax component in the toner (F) was observed by TEM, it was found to be substantially spherical and dispersed in the binder resin as shown in the schematic diagram of FIG. The value of (r / R) _st was 0.40.

(Toner Production Examples 7 to 10) In addition to changing the types and amounts of the oxycarboxylic acid and the wax component,
After obtaining polymer particles (G) to (J) in the same manner as in Production Example 6 of the toner except that the conditions of the pH of the aqueous dispersion medium during the polymerization reaction were changed, the toners (G) to (J) were obtained. ) Was prepared.

The types and amounts of the oxycarboxylic acid and the wax component in each of the production examples, and the toner (G)
Table 3 summarizes the properties of (J).

(Production Examples 3 and 4 of Comparative Toner) The types and amounts of the oxycarboxylic acid and the wax component were changed, and the pH of the aqueous dispersion medium in the first reaction process (initial stage) and the polymerization conversion at the end of the process were changed. (Polymerization conversion rate at the time of switching the reaction course), and the pH of the aqueous dispersion medium in the second reaction course (late stage)
Comparative Polymer Particles (c) and (d) were obtained in the same manner as in Production Example 1 of the toner except that the above was changed, and then Comparative Toners (c) and (d) were prepared.

Table 3 shows the types and addition weights of the oxycarboxylic acid and the wax component, the conditions of the pH of the aqueous dispersion medium, and various properties of the obtained toner, which were used in the above-mentioned toner production examples and comparative toner production examples. Are shown together.

[0254]

[Table 3]

Example 7 A commercially available laser beam printer L was used as an image forming apparatus.
BP-220 (manufactured by Canon Inc.) was modified and used in the following configuration.

As the fixing device, a film-type heating / pressing means shown in FIG. 3 was used, which was not provided with a separation claw or a mechanism for applying an anti-offset liquid.

As the heat-resistant endless film, a 60-μm-thick polyimide film having a low-resistance release layer in which a conductive material is dispersed in PTFE on the contact surface with the transfer material is used. After priming the metal core, an elastic layer of dimethyl silicone rubber foam,
Further, an elastic layer of dimethylsilicone rubber and a surface layer of PTFE having a thickness of 20 μm were provided with a primer layer interposed therebetween.

Further, inside the heat-resistant endless film, a heating resistor is screen-printed on a heater substrate as a heating body, and a low-heat-capacity linear heating body provided with a heat-resistant surface protective layer is provided. When the pressure means is activated, the surface temperature of the fixing roller is adjusted to 170 ° C., and the heating element and the pressure roller are connected to each other through a heat-resistant endless film.
A contact pressure of N (10 kgf) was applied so that a nip portion having a width of 5 mm was formed.

A medium resistance rubber roller made of dimethyl silicone rubber in which carbon black is dispersed and whose resistance is adjusted is used as a toner carrier at the developing unit of the process cartridge of the above-mentioned image forming apparatus, and is brought into contact with the photosensitive drum. The toner (F) obtained in Toner Production Example 6 was charged, and a printout test was performed in the same manner as in Example 1 at a printout speed of 6 sheets (A4 size) / min. The matching between the printed image and the heating and pressing means was evaluated.

Table 4 shows the results of these evaluations.

Examples 8 to 11 Evaluations were made in the same manner as in Example 7 except that each of the toners (G) to (J) was used.

Table 4 shows the results of these evaluations.

Comparative Examples 3 and 4 Evaluations were made in the same manner as in Example 7 except that each of the comparative toners (c) and (d) was used.

Table 4 shows the results of these evaluations.

The evaluation items and the evaluation criteria described in Examples 7 to 11 and Comparative Examples 3 and 4 will be described.

[Evaluation Items] <1> Reproducibility of Fine Lines The conditions are as shown in Table 2.

<2> Fixing state of thin line The case shown in Table 2 is followed.

<3> Matching with Heat-Resistant Endless Film After the printout test, the state of fixation of the residual toner on the heat-resistant endless film and the effect on the printout image were visually evaluated. A: No toner adhesion occurred. B: Contamination due to paper dust occurred, but almost no toner adhesion was observed. C: Contamination due to paper dust and toner adhesion to edges were observed, but a fixed image was observed. D: The printout image is wrapped during the printout test

<4> Matching with pressure roller According to the case shown in Table 2.

<5> Releasability of Pressure Roller Surface Based on the case shown in Table 2.

[0271]

[Table 4]

(Production Example 11 of Toner)
2 liters equipped with AMICS (M-Technic)
And 700 parts by mass of ion-exchanged water
0.1 mol / liter-Na_ThreePO_Four800 mass of aqueous solution
And the rotation speed of the high-speed stirring device is 15,000 rpm
And heated to 60 ° C. 1.0 mol here
/ Liter-CaCl _TwoAdd 70 parts by mass of aqueous solution
Small sparingly water-soluble dispersion stabilizer Ca_Three(PO_Four)_TwoWater component containing
A dispersion medium was prepared. Furthermore, p of aqueous dispersion medium is added with dilute hydrochloric acid.
It was re-prepared so that H became 5.5.

On the other hand, as the dispersoids: 77 parts by mass of styrene monomer 23 parts by mass of 2-ethylhexyl acrylate monomer 0.3 part by mass of divinylbenzene monomer Carbon black (BET specific surface area = 35 m ² / g) 5 parts by mass ・ Polyester resin (acid value = 15 mg KOH / g) 3 parts by mass ・ Charge controlling agent (boron complex of benzyl acid) 2 parts by mass ・ 1 part by mass of oxycarboxylic acid (1-A) ・ Ester wax ( (Melting point = 55 ° C.) After dispersing the mixture consisting of 15 parts by mass using an attritor (manufactured by Mitsui Kinzoku Co., Ltd.) for 3 hours, 5 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) was added. A polymerizable monomer composition was prepared.

Next, the polymerizable monomer was added to the aqueous dispersion medium.
The body composition is charged, and N at an internal temperature of 60 ° C. _TwoAtmosphere, high speed
While maintaining the rotation speed of the stirrer at 15000 rpm, 1
The mixture was stirred for 5 minutes to granulate the polymerizable monomer composition. That
After that, replace the stirring device with a paddle stirring blade,
While maintaining the same temperature while stirring at 80 rpm, a polymerizable vinyl
When the polymerization conversion of the monomer reaches 95%, the reaction is terminated.
1 mol / L aqueous solution of NaOH was added to
The pH of the dispersion medium was changed to 11. Further, the reaction temperature is 85 ° C.
And when the polymerization conversion reaches almost 100%
The polymerization reaction was completed.

After the completion of the polymerization, polymer particles (K) were obtained in the same manner as in Production Example 1 of the toner.

The polymer particles (K) (100 parts by mass) and hydrophobic
Silica fine powder (BET; 200m) ^Two/ G) 2 parts by mass
Dry-mix with a Henschel mixer (Mitsui Metals),
The toner (K) was used.

The amount A of oxycarboxylic acid extracted from 1 g of the toner (K) with methanol was 1.55 mg.
The amount B of oxycarboxylic acid extracted with a 0.1 mol / liter aqueous sodium hydroxide solution is 0.94 m.
In g, the value of A / B was 1.65 and the value of (3/4) B + 1 was 1.71.

The circle-equivalent number average diameter was 4.9 μm.
The average circularity in the circularity frequency distribution is 0.982, the circularity standard deviation is 0.021, the number of toner particles having a circularity of less than 0.95 is 5.3% by number, and the GPC of the binder resin in the toner is Was found to have a peak molecular weight of 170000 and Mw / Mn of 15.

Further, when the dispersion state of the wax component in the toner (K) was observed with a TEM, it was found to be substantially spherical and dispersed in the binder resin as shown in the schematic diagram of FIG. The value of (r / R) _st was 0.45.

(Toner Production Examples 12 to 15) The same procedures as those of the above-described toner were carried out except that the types and amounts of the colorant, oxycarboxylic acid and wax component were changed and the pH conditions of the aqueous dispersion medium during the polymerization reaction were changed. After obtaining polymer particles (L) to (O) in the same manner as in Production Example 11, toner (L)
~ (O) was prepared.

Table 5 summarizes the types and amounts of the colorants, oxycarboxylic acids and wax components and the properties of the toners (L) to (O) in each of the production examples.

(Production Example 5 of Comparative Toner) The following materials were previously mixed, melted and kneaded with a twin-screw extruder, and the cooled kneaded material was coarsely pulverized with a hammer mill, and the coarsely pulverized material was finely pulverized with a jet mill. The obtained finely pulverized product was classified to obtain a classified powder (e). -Binder resin 100 parts by mass (styrene-2-ethylhexyl acrylate-divinylbenzene copolymer peak molecular weight = 170000, Mw / Mn = 4.5, Tg = 60 ° C)-Used in toner production example 11 5 parts by mass of carbon black 3 parts by mass of polyester resin used in toner production example 11 2 parts by mass of charge control agent used in toner production example 11 2 parts by mass of oxycarboxylic acid (1-A) ester wax (Melting point = 75 ° C.) 7 parts by mass A comparative toner (e) was prepared in the same manner as in Production Example 11 of the toner using the classified powder (e).

When the dispersion state of the wax component in the comparative toner (e) was observed with a TEM, the wax component was finely dispersed, and the (r / R) _st was 0.01 or less.

(Production Examples 6 to 8 of Comparative Toner) Colorant,
After obtaining classified products (f) to (h) in the same manner as in Production Example 5 of the comparative toner except that the types and amounts of the oxycarboxylic acid and the wax component were changed, the comparative toner (f)
~ (H) was prepared.

Table 5 summarizes the types and addition weights of the colorant, the oxycarboxylic acid and the wax component and the properties of the comparative toners (f) to (h) in each of the production examples.

[0286]

[Table 5]

Example 12 As an image forming apparatus, a commercially available full-color laser beam printer LBP-2030 (manufactured by Canon Inc.) was modified and used as follows.

In the fixing device, an electromagnetic induction type heating / pressing means shown in FIG. 4 was used, which was not provided with a separating claw or an anti-offset liquid applying mechanism.

The heat-resistant endless film has a thickness of 50
A three-layer structure in which a cylindrical nickel film material of μm is used as a resistor layer that generates heat by electromagnetic induction, and its outer peripheral surface is covered with an elastic layer made of dimethyl silicone rubber and a release layer made of PFA, is used. After the SUS core is treated with a primer, the pressure roller is provided with an elastic layer of foam of dimethyl silicone rubber, and an elastic layer of dimethyl silicone rubber and a surface layer of 50 μm thick PFA tube through the primer layer. Was used.

A magnetic field generating means is provided inside the cylindrical heat-resistant endless film so that the surface temperature of the heat-resistant endless film becomes 180 ° C. when the heating and pressing means is operated. 245N (25k) is applied to the magnetic field generating means and the pressure roller via a film.
gf) was applied so that a nip portion having a width of 6 mm was formed.

The toner (K) obtained in Toner Production Example 11 is charged into the process cartridge of the above-described image forming apparatus, and 100,000 prints are performed in the monochrome mode at a printout speed of 12 prints (A4 size) / min. An out test was performed to evaluate the matching between the obtained printout image and the heating and pressing means.

The results of these evaluations are shown in Table 6.

Examples 13 to 16 Except for using the toners (L) to (O), respectively. Evaluation was performed in the same manner as in Example 12.

The results of these evaluations are shown in Table 6.

Comparative Examples 5 to 8 Evaluations were made in the same manner as in Example 12, except that each of the comparative toners (e) to (h) was used.

Table 6 shows the results of these evaluations.

The evaluation items and the evaluation criteria described in Examples 12 to 16 and Comparative Examples 5 to 8 will be described.

[Evaluation Items] <1> Reproducibility of Fine Lines The same as in the case shown in Table 2.

<2> Fixing state of fine line The same as in the case shown in Table 2.

<3> Matching with Heat-Resistant Endless Film After completion of the printout test, the state of fixation of the residual toner on the heat-resistant endless film and the effect on the printout image were visually evaluated. A: No toner adhesion occurred. B: Contamination due to paper dust occurred, but almost no toner adhesion was observed. C: Contamination due to paper dust and toner adhesion to edges were observed, but a fixed image was observed. D: The printout image is wrapped during the printout test

<4> Matching with pressure roller According to the case shown in Table 2.

<5> Releasability of Pressure Roller Surface According to the case shown in Table 2.

[0303]

[Table 6]

Example 17 The toner (K) as a black toner and the toners (M) to (O) as color toners were charged into a process cartridge, and “White recycled paper EW-100” was used as a transfer material. (A blending ratio of recycled pulp = 100%), a graphic image in which the image area ratio of each color is set to about 10% is printed at a printout speed of 3 sheets (A4 size) / min in full color mode.
10,000 printout tests were performed.

As a result, a vivid full-color image excellent in resolution was stably obtained, the fixed state of the fixed image was good, and there was no problem in matching with the heating and pressing means. Was.

Furthermore, even when a transparency film was used as the transfer material, no image scattering occurred, the fixed state of the fixed image was good, and a desired color reproduction was obtained in the projected image by the overhead projector.

Comparative Example 9 A print-out test was performed in the same manner as in Example 17 using the black toner and the comparative toners (e) to (h) as the color toners. The transfer material was transferred onto the heat-resistant endless film surface. Because of the frequent occurrence of the wrapping phenomenon, a roller for applying dimethyl silicone oil as an anti-offset liquid was disposed on the surface of the heat-resistant endless film, and the consumption of dimethyl silicone oil applied to the contact surface with the toner image was 0. When it was set to be from 0.30 to 0.035 mg / cm ² , the above-mentioned wrapping phenomenon was prevented.

However, when the printout test was continued in this state, the obtained image had a solid feeling and glossiness. Further, when a transparency film was used as the transfer material, the projection image produced by the overhead projector was clouded by dimethyl silicone oil, and the desired color reproduction was not obtained.

[0309]

As described above, according to the present invention,
By using a toner having a specified content of oxycarboxylic acid, the heating and pressurizing means with a small amount of application of the anti-offset liquid or the heating and pressurizing means with no application of the anti-offset liquid can be used. It is possible to adapt to various transfer materials without deteriorating the performance of the pressing means for a long period of time, and it is possible to obtain a high-resolution and high-definition fixed image.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of a heat roller type heating / pressing means used in an embodiment of the present invention.

FIG. 2 is a heating and pressing means using a heat roller method having a separation claw, which is provided with a brush-like cleaning roller (a) and a cleaning roller impregnated with an anti-offset liquid. It is a schematic explanatory drawing which shows (b).

FIG. 3 is an explanatory view showing an exploded perspective view (a) and an enlarged cross section (b) of a main part of a heating and pressing means using a film system used in an embodiment of the present invention.

FIG. 4 is a schematic explanatory view of an electromagnetic induction type heating / pressing means used in an embodiment of the present invention.

FIG. 5 is a schematic diagram illustrating an example of a cross section of a toner particle including a wax component.

FIG. 6 is an explanatory diagram of a line image for evaluating reproducibility of a fine line and a fixing state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Rotary heating member (heating roller) 11a Heating body (heater) 12 Rotating pressing member (pressure roller) 13 Conveyor belt 30 Stay 31 Heating body 31a Heater board 31b Heating body 31c Surface protection layer 31d Temperature sensor 32 Endless film 33 Addition Pressure roller 34 Coil spring 35 Film end regulating flange 36 Power supply connector 37 Disconnecting member 38 Inlet guide 39 Outlet guide (separation guide) 40 Exciting coil 42 Coil core material (magnetic material) 47 Endless film N Nip T Toner image P Transfer material

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Makoto Kambayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term within Canon Inc. (reference) 2H005 AA06 AA15 CA13 CA14 CA30 DA06 EA05 EA07 FB01 2H033 BA11 BA12 BA25 BA58 BB01 BB28 BE03 BE06 3K058 AA34 AA45 AA64 BA18 CE02 CE12 CE13 CE17 CE19 DA02 3K059 AB19 AB20 AB27 AB28 AD34 CD64 CD65 CD75 CD77

Claims (15)

[Claims] 1. An image forming method for heating and pressurizing and fixing a toner image on a transfer material by a heating and pressurizing means to form a fixed image on the transfer material, wherein the heating and pressurizing means comprises: And (ii) an anti-offset applied to the contact surface of the transfer material with the toner image. The liquid consumption is set to 0 to 0.025 mg / cm ² (based on the unit area of the transfer material), and (iii) the rotary heating member and the rotary pressurized while nipping and transferring the transfer material in the nip portion. The toner image on the transfer material is heated and pressed by a member, and the toner forming the toner image is a dry toner containing at least a binder resin, a colorant, a wax component, and an oxycarboxylic acid. The tona The mass A (mg) of oxycarboxylic acid extracted with methanol from −1 g and the mass B (mg) of oxycarboxylic acid extracted with 0.1 mol / liter aqueous sodium hydroxide solution are as follows: A / B = 1 0.05 to 3.00 B = 0.10 to 3.50. 2. A rotary heating member having a cylindrical heating roller having a heating element inside, a cleaning member for removing residual toner remaining on the surface of the heating roller and a separation member for preventing winding of the transfer material. 2. The image forming method according to claim 1, wherein a heat roller type heating / pressing unit not provided is used. 3. A cylindrical heat-resistant endless film which has a heating body fixedly supported on a support and is driven to move while being pressed against the heating body as a rotary heating member, and a toner is provided via the endless film. 2. The image forming method according to claim 1, wherein a film type heating / pressing unit for heating / pressing the image is used. 4. An electromagnetic induction system in which a heating element comprising a cylindrical heat-resistant endless film having a magnetic field generating means therein and having a heat generating layer for generating electromagnetic induction by the action of the magnetic field generating means is used as a rotary heating member. 2. The image forming method according to claim 1, wherein the heating and pressurizing unit is used. 5. The image forming apparatus according to claim 1, wherein a heating / pressurizing unit is used in which an offset preventing liquid is not applied to a contact surface of the transfer material with the toner image. Method. 6. The image forming method according to claim 1, wherein the oxycarboxylic acid is a compound represented by the following formula (1). Embedded image [In the above formula (1), (A) is selected from the following group, and X ₁
Represents a hydrogen atom, a sodium atom, a potassium atom, ammonium or an aliphatic ammonium. ] 7. The image forming method according to claim 1, wherein the oxycarboxylic acid is a compound represented by the following formula (2). Embedded image [In the above formula (2), X ₂ represents a hydrogen atom, a sodium atom, a potassium atom, ammonium, or an aliphatic ammonium, and R ₄ represents a C _{1 to} C ₂₂ alkyl group or alkenyl group, or an aryl group. , R ₅ are hydrogen atoms, C ₁ -C
_{22 represents} an alkyl group, an alkenyl group, an aryl group, and an alkoxy group. ] 8. The amount A of oxycarboxylic acid extracted with methanol from the toner and the amount B of oxycarboxylic acid extracted with a 0.1 mol / liter aqueous sodium hydroxide solution are represented by the following formula: The image forming method according to claim 1, wherein the following formula is satisfied. 9. In a scattergram of circle-based circularity-circularity based on the number of toners measured by a flow-type particle image measuring device, the circle-equivalent number average diameter D ₁ (μm) of the toner is 2
And the average circularity of the toner is 0.1 to 10 μm.
The image forming method according to any one of claims 1 to 8, wherein the circularity standard deviation is 920 to 0.995 and less than 0.040. 10. In the circle-equivalent diameter-circularity scattergram, the average circularity of the toner is 0.950 to 0.995.
The image forming method according to claim 9, wherein the circularity standard deviation is less than 0.035. 11. In a circle-equivalent diameter-circularity scattergram, the average circularity of the toner is 0.970 to 0.990.
The image forming method according to claim 9, wherein the circularity standard deviation is 0.015 or more and less than 0.035. 12. In a scattergram of circular equivalent diameter-circularity based on the number of toners measured by a flow-type particle image measuring device, toner particles having a circularity of less than 0.950 are not more than 15% by number. The image forming method according to claim 1. 13. A tomographic observation of toner particles using a transmission electron microscope (TEM): (1) A circle-equivalent weight average diameter D ₄ (μm ) To 0.9
Twenty tomographic planes of toner particles exhibiting a long diameter R (μm) satisfying the relationship of ≦ R / D ₄ ≦ 1.1 are selected. (2) A phase caused by a wax component present in the tomographic planes of the selected toner particles. Among the separation structures, the longest diameter r of the largest one is measured. (3) The arithmetic mean value (r / R) _{st of the obtained} r / R is 0.05 ≦ (r / R) _st ≦ 0. The image forming method according to any one of claims 1 to 12, wherein the wax component is dispersed in the binder resin in a substantially spherical and / or spindle-shaped island shape so as to satisfy 95. . 14. arithmetic mean value of r / R (r / R) st is substantially in 0.25 ≦ (r / R) the wax component so as to satisfy the _st ≦ 0.90 is binder resin 14. The image forming method according to claim 13, wherein the particles are dispersed in a spherical and / or spindle-shaped island shape. 15. In tomographic observation of toner particles using a transmission electron microscope (TEM), the surface of the toner particles is subjected to electron staining with ruthenium tetroxide (RuO ₄ ) and / or osmium tetroxide (OsO ₄ ). A thin layer of a material identified by the method is formed, and a binder resin and a wax component are present in the toner inner direction, and the wax component is substantially spherical and / or spindle-shaped in the binder resin. 15. The method according to claim 1, wherein the particles are dispersed in a shape.
The image forming method according to any one of the above.