JP6843563B2 - toner - Google Patents

Description

The present invention relates to toners used in image forming methods for visualizing electrophotographic and electrostatic charge images.

An image forming apparatus using an electrophotographic method is required to have higher image quality. In particular, users are strongly demanding to provide stable image quality that does not depend on the environment, and for this reason, there is a demand for the development of toner that exhibits excellent charging performance regardless of the usage environment. Further, in recent years, in addition to improving the image quality, there is a high demand for higher speed and longer life of the device, and there is a problem that it becomes more difficult for the toner to obtain stable chargeability.
Generally, in order to obtain stable chargeability even during long-term use, the toner contains inorganic fine particle powder such as a metal oxide as an external additive. Further, among the external additives, those in which the surface of the external additive is treated with a charge control agent have been proposed in order to obtain stable chargeability even during long-term use.
For example, Patent Document 1 proposes that a toner to which a charge control agent is treated on the surface of an external additive has excellent charge rising property and charge stability. However, when toner containing a charge control agent treated on the surface of the external additive is used in a high temperature and high humidity (32 ° C, 80% RT) environment, no effect on the charge performance of the toner is observed and fog occurs. I found out that In addition, it was also found that filming occurs on the photoconductor drum due to the fusion of toner particles and an external additive. That is, the external additive treated with the charge control agent could obtain the effect of charge stabilization only in a limited environment.
In order to solve this problem, Patent Document 2 states that a toner obtained by adding a charge control agent and a hydrophobizing agent to the surface of an external additive has excellent charge rise and charge stability. Proposals have been made. However, when a toner containing a charge control agent and a hydrophobizing agent treated on the surface of the external additive is used in a low temperature and low humidity (15 ° C., 30% RT) environment, a certain effect on the charge performance of the toner is obtained. However, it was found that image harmful effects derived from the photoconductor drum filming occur.
As described above, even if the external additive is treated with a charge control agent in order to obtain stable chargeability, there are still many technical problems in suppressing filming on the photoconductor drum, and there is still room for improvement. Have.

Japanese Unexamined Patent Publication No. 2006-301130 JP-A-2007-65373

An object of the present invention is to provide a toner that solves the above problems. Specifically, it is an object of the present invention to provide a toner that suppresses filming and fog on a photoconductor drum regardless of the usage environment.

The present invention is a toner having toner particles containing a binder resin and a colorant and an external additive A.
The external preparation A is
i) It has a shape with a density of 0.40 or more and 0.80 or less represented by the following formula (1).
Dense density = Area of external additive / Area of external additive surrounded by envelopes Equation (1)
ii) An external additive obtained by treating the surface of inorganic fine particles with a silane or silazane compound and then treating with a charge control agent.
iii) The present invention relates to a toner characterized in that the specific surface area of the inorganic fine particles is 30 m ² / g or more and 140 m ^{2 / g or less.}
Further, the present invention is a toner having toner particles containing a binder resin and a colorant and an external additive A.
The external preparation A is
i) It has a shape with a density of 0.40 or more and 0.80 or less represented by the following formula (1).
Dense density = Area of external additive / Area of external additive surrounded by envelopes Equation (1)
ii) After surface treatment with a silane or silazane compound, a metal compound of aromatic carboxylic acid, a metal compound of azo dye or azo pigment, a polymer compound having a sulfonic acid group or a carboxylic acid group as a substituent, a urea compound, or calix. It is an external preparation obtained by treating with a compound selected from the group consisting of an arene, a quaternary ammonium salt, a polymer compound having a quaternary ammonium salt in a side chain, a guanidine compound, a niglosin compound, and an imidazole compound. ,
iii) The present invention relates to a toner characterized in that the specific surface area of the inorganic fine particles is 30 m ² / g or more and 140 m ^{2 / g or less.}

According to the present invention, it is possible to provide a toner that suppresses filming and fog on a photoconductor drum regardless of the usage environment.

It is the schematic which shows the polycarbonate thin film adhesion measurement method. This is an example of a binarized image used for quantifying the shape of the external additive.

It is known that a toner to which an external additive which has been surface-treated with a charge control agent is added has excellent charge rising property and excellent charge stability. In addition, there is a feature that the difference in the amount of charge between the environments can be suppressed even when used in different environments (low temperature, low humidity, high temperature and high humidity). Therefore, from the viewpoint of improving the image quality, when the toner to which the external additive surface-treated with the charge control agent was added was evaluated, although there was a certain effect on the charge of the toner, the filming was performed on the photoconductor drum in any environment. Was generated, and it was found that the image was adversely affected.

As a result of analyzing the surface of the photoconductor drum that caused the filming, it was confirmed that the filming generated in the low temperature and low humidity environment was caused by the toner particles. The present inventors consider the reason as follows. The toner to which the external additive surface-treated by the charge control agent is added has an increased electrostatic charge amount of the toner, so that the electrostatic adhesion between the photoconductor drum and the toner increases and slips through the cleaning blade. As a result, it is considered that filming occurred because a part of the toner that had slipped through the cleaning part was rubbed against the photoconductor drum.

On the other hand, it was confirmed that the filming that occurred in the high temperature and high humidity environment was caused by the external additive that had migrated from the toner surface to the photoconductor drum surface. The present inventors consider the reason as follows. The inorganic fine particles constituting the external additive surface-treated with the charge control agent have many hydroxyl groups and are configured to easily adsorb moisture in the air. As a result, it is considered that the filming occurred because the adhesive force (liquid cross-linking force) between the photoconductor drum and the external additive increased and the external additive slipped through the cleaning blade.

As described above, in order to increase the speed and the life of the toner in the future, it is necessary to develop a toner capable of both stabilizing the charge of the toner and suppressing the filming. As a result of studies to solve the above-mentioned problems, the present inventors have come up with the idea that the above-mentioned problems can be solved by using a toner to which an external additive having the following characteristics is added.

That is, it is a toner having toner particles containing a binder resin and a colorant and an external additive A.
The external preparation A is
i) It has a shape with a density of 0.40 or more and 0.80 or less represented by the following formula (1).
Dense density = Area of external additive / Area of external additive surrounded by envelopes Equation (1)
ii) An external additive obtained by treating the surface of inorganic fine particles with a silane or silazane compound and then treating with a charge control agent.
iii) The specific surface area of the inorganic fine particles is 30 m ² / g or more and 140 m ² / g or less.

The external additive A used for the toner of the present invention will be specifically described below.

The external additive A used in the present invention is an external additive in which the surface of inorganic fine particles is treated with a charge control agent.

In the blade type cleaning device, a strong linear pressure is applied between the photoconductor drum and the blade to prevent the toner and external additive from slipping through, and when the deposits generated on the photoconductor drum pass through the blade nip. , Filming is likely to occur. Therefore, it is necessary to design the toner in consideration of forming a layer by retaining the external additive between the photoconductor drum and the blade and blocking the passage of deposits. As a means for forming the block layer, it is common that the external additive that adheres to the toner surface and adheres to the toner surface is transferred when it comes into contact with the surface of the photoconductor drum. However, the block layer is sandwiched between the photoconductor drum-blade nip portion, and when the frictional resistance of the block layer with respect to the rotating photoconductor drum is large, the block layer is drawn to the downstream side of the nip portion and is a block layer. Cannot be maintained. As described above, since the block layer is formed by the external additive that migrates from the toner when the toner comes into contact with the photoconductor drum, the external additive externally added to the toner slides well on the drum surface. Must show sex.

As a result of diligent studies by the present inventors focusing on the slipperiness of the external additive A, it was found that good slipperiness can be obtained by treating the surface of the inorganic fine particles with a charge control agent. The reason is not clear, but it is considered as follows.

Usually, the charge control agent has a polar substituent, and such a substituent is composed of an atom having a high electronegativity. In general, it is known that a substance having an atom having a large electronegativity has a small coefficient of friction, which can be understood by considering the definition of van der Waals force. The van der Waals force is the attractive force caused by the fluctuation of electrons generated by the approach of two atoms. Therefore, the van der Waals force is small for a substance having a high electronegativity and less likely to cause electron fluctuations. Therefore, the coefficient of friction also becomes small. For this reason, it is considered that the inorganic fine particles surface-treated with the charge control agent exhibit low friction characteristics with respect to the partner substance.

Since the compound used as a charge control agent in the toner particles is effective for the surface treatment of the fine particles A, the compound used for the surface treatment is called a "charge control agent", but the charge control function I'm not using.

The charge control agent used in the present invention may be any known charge control agent used for toner, and examples of the negative charge control agent include salicylic acid, alkylsalicylic acid, dialkylsalicylic acid, naphthoic acid, and dicarboxylic acid. Examples thereof include a metal compound of an aromatic carboxylic acid, a metal compound of an azo dye or an azo pigment, a polymer compound having a sulfonic acid group or a carboxylic acid group as a substituent, a urea compound, and calix arene. Examples of the positive charge control agent include a quaternary ammonium salt, a polymer compound having a quaternary ammonium salt in the side chain, a guanidine compound, a niglosin compound, and an imidazole compound. In the present invention, from the viewpoint of ease of treatment on the surface of the external additive, a polymer compound (charge control resin) is preferable, and a polymer compound having a sulfonic acid group or a salicylic acid group as a substituent is further used. It is preferable to use it. Further, it is more preferable that the weight average molecular weight (Mw) of the charge control resin is 1000 or more and 300,000 or less because the surface of the external additive can be uniformly treated. More preferably, it is 3000 or more and 50,000 or less.

The external additive A has a metal compound of an aromatic carboxylic acid, a metal compound of an azo dye or an azo pigment, a polymer having a sulfonic acid group or a carboxy group, a quaternary ammonium salt, and a polymer having a quaternary ammonium salt on the surface. It is preferable that the compound has a compound selected from the group consisting of a guanidine compound, a niglosin compound and an imidazole compound. Further, it is more preferable that the compound is a compound selected from the group consisting of a monoazo metal compound, a polymer having a sulfonic acid group or a carboxy group.

Examples of the polymer having a sulfonic acid group include resins derived from styrene sulfonic acid, 2-acrylamide-2-methylpropane sulfonic acid (AMPS), vinyl sulfonic acid, methacryl sulfonic acid, maleimide derivatives, styrene derivatives and the like, and the following. The maleic acid amide derivative of the formula (5) can be exemplified, and a resin having a partial structure derived from 2-acrylamide-2-methylpropanesulfonic acid is particularly preferable. The content of the partial structure derived from 2-acrylamide-2-methylpropanesulfonic acid in the charge control resin is preferably 0.3% by mass or more and 20.0% by mass or less.

Examples of the polymer having a carboxy group and the polymer having a salicylic acid group include 3-vinylsalicylic acid, 4-vinylsalicylic acid, 5-vinylsalicylic acid, 6-vinylsalicylic acid, 3-vinyl-5-isopropylsalicylic acid, and 3-vinyl-5. Examples of -t-butylsalicylic acid, 4-vinyl-6-t-butylsalicylic acid, and polymer A having a monovalent group a represented by the following formula (4) can be exemplified, and in particular, the monovalent represented by the following formula (4). Polymer A having the group a of is preferable.

（式中、Ｒ¹は、それぞれ独立して、ヒドロキシ基、カルボキシ基、炭素数が１以上１８以下のアルキル基、又は、炭素数が１以上１８以下のアルコキシ基を示し、Ｒ²は水素原子、ヒドロキシ基、炭素数１以上１８以下のアルキル基、又は、炭素数１以上１８以下のアルコキシ基を示し、ｇは１以上３以下の整数であり、ｈは０以上３以下の整数である。）

(In the formula, R ¹ independently represents a hydroxy group, a carboxy group, an alkyl group having 1 or more and 18 or less carbon atoms, or an alkoxy group having 1 or more and 18 or less carbon ^{atoms, and R 2} is a hydrogen atom. , A hydroxy group, an alkyl group having 1 or more and 18 or less carbon atoms, or an alkoxy group having 1 or more and 18 or less carbon atoms, g is an integer of 1 or more and 3 or less, and h is an integer of 0 or more and 3 or less. )

Examples of the alkyl group in R ¹ and R ² include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, an s-butyl group, a t-butyl group and the like, and examples of the alkoxy group include. Examples include a methoxy group, an ethoxy group, a propoxy group and the like.

The main chain structure of the polymer A is not particularly limited.

Examples thereof include vinyl-based polymers, polyester-based polymers, polyamide-based polymers, polyurethane-based polymers, and polyether-based polymers. In addition, a hybrid type polymer in which two or more of these are combined can also be mentioned. Among those listed here, a vinyl-based polymer is preferable in consideration of the adhesion to the toner matrix particles. The content of the monovalent group in the polymer A is preferably 0.3% by mass or more and 30% by mass or less.

The polymer A can be synthesized, for example, by using a compound having a polymerizable functional group such as a vinyl group at the substitution position of the group represented by the formula (4) as a monomer. In that case, the polymer A having a monovalent group a is represented by the following formula (4-2).

［前記式（４−２）中、Ｒ³は、それぞれ独立して、炭素数１以上１８以下（好ましくは１以上４以下）のアルキル基、又は、炭素数１以上１８以下（好ましくは１以上４以下）のアルコキシ基を表す。Ｒ⁴は、水素原子、ヒドロキシ基、炭素数１以上１８以下（好ましくは１以上４以下）のアルキル基、又は、炭素数１以上１８以下（好ましくは１以上４以下）のアルコキシ基を表す。Ｒ⁵は水素原子又はメチル基を表し、ｉは１以上３以下の整数を表し、ｊは０以上３以下の整数を表す。］

[In the above formula (4-2), R ³ is independently an alkyl group having 1 or more and 18 or less carbon atoms (preferably 1 or more and 4 or less) or 1 or more and 18 or less carbon atoms (preferably 1 or more). Represents an alkoxy group (4 or less). R ⁴ represents a hydrogen atom, a hydroxy group, an alkyl group having 1 or more and 18 or less carbon atoms (preferably 1 or more and 4 or less), or an alkoxy group having 1 or more and 18 or less carbon atoms (preferably 1 or more and 4 or less). R ⁵ represents a hydrogen atom or a methyl group, i represents an integer of 1 or more and 3 or less, and j represents an integer of 0 or more and 3 or less. ]

Further, the charge control resin used in the present invention preferably has an acid value of 15 mgKOH / mg or more and 35 mgKOH / mg or less. As described above, it is considered that the friction reducing effect in the present invention is expressed by a polar substituent. Therefore, by setting the acid value to 15 mgKOH / mg or more, a good friction reducing effect can be exhibited. Further, by setting the acid value value to 35 mgKOH / mg or less, it is preferable that moisture in the air is less likely to be adsorbed on the charge control agent and stable chargeability can be obtained, so that the occurrence of fog can be suppressed. The acid value can be controlled by the type of monomer used.

Further, in order to suppress the filming on the photoconductor drum even in different environments (low temperature and low humidity, high temperature and high humidity), it is necessary to treat the external additive A with a silane or a silazane compound. In addition, the order in which the charge control agent and the silane or silazane compound are surface-treated with respect to the external additive A is important. That is, it is necessary to add the external additive A obtained by treating the surface of the inorganic fine particles with a silane or a silazane compound and then treating with a charge control agent to the toner of the present invention.

As described above, the filming on the photoconductor drum that occurs in a high temperature and high humidity environment is performed between the photoconductor drum and the external additive by adsorbing moisture in the air to the hydroxyl groups existing on the surface of the inorganic fine particles. It is believed that this is due to the increase in the adhesive force (liquid cross-linking force) of the. Therefore, it is necessary to reduce the hydroxyl groups existing on the surface of the inorganic fine particles, and it is necessary to carry out a hydrophobizing treatment with a silane or a silazane compound. As a result, the adhesive force of the external additive to the photoconductor drum can be suppressed, and the filming on the drum in a high temperature and high humidity environment can be suppressed.

In addition, as a result of diligent studies by the present inventors focusing on the order of surface treatments, the slipperiness of the external additives is lost unless the surface treatments of the external additives are performed in a specific order. There was found. That is, in order to achieve both slipperiness and hydrophobicity of the external additive, the external additive A obtained by treating the surface of the inorganic fine particles with a silane or a silazane compound and then treating with a charge control agent is used. It is necessary to add.

In addition, an attempt was made to specify the surface composition of the external additive A treated in this order, but the laminated structure was specified because the amount of each was very small and the particle size was small. It was difficult to do. Therefore, in the present invention, the invention is specified by defining the order of processing.

The reason why the effect is particularly obtained when the processing is performed in the above order is not clear, but it is considered as follows.

As described above, in order for the external additive to exhibit good slipperiness, the substituent having the polarity of the charge control agent must be arranged on the outermost surface of the external additive and in contact with the surface of the photoconductor drum. Must be. On the other hand, the silane or silazane compound that has been coupled to the surface of the external additive has a sterically large structure. Therefore, when the treatment with the silane or the silazane compound is performed after the treatment with the charge control agent, the large three-dimensional structure of the silane or the silazane compound covers the polar substituent of the charge control agent. For this reason, it is considered that the slipperiness may be lost because the polar substituent is not arranged on the outermost surface of the external additive.

It was also found that the slipperiness of the external additive was not exhibited even when the treatment with the charge control agent and the treatment with the silane or silazane compound were performed at the same time. It is considered that this is because the treatment with the silane or silazane compound involves a reaction time because it is a chemical bond, whereas the treatment with a charge control agent does not involve a reaction time because it is not a chemical bond. That is, even if the two treatment agents are treated at the same time, it is the charge control agent that finishes the treatment first, and then the treatment with the silane or silazane compound proceeds. As a result, it is suspected that the slipperiness may have been lost because the polar substituent of the charge control agent was not arranged on the outermost surface of the external additive.

As the silane or silazane compound used in the treatment of the external preparation of the present invention, known silane or silazane compounds can be used without particular limitation.

Specifically, hexamethyldisilazane, lymethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorsilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, brommethyldimethylchlor. Silane, α-chloroethyl trichlorosilane, β-chloroethyl trichlorosilane, chloromethyldimethylchlorosilane, triorganosilyl mercaptan, trimethylsilyl mercaptan, triorganosilyl acrylate, vinyl dimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyldi Examples thereof include ethoxysilane, isobutyltrimethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, octyltriethoxysilane, and decyltrimethoxysilane. Above all, it is preferable to use an alkyl group having 1 to 2 carbon atoms bonded to the silicon atom in that the immobilization rate of the charge control agent can be increased. Further, from the viewpoint of treatment uniformity and certainty of coupling bond, it is more preferable to use hexamethyldisilazane.

The treatment with at least one of alkoxysilane or silazane required to obtain the external preparation of the present invention utilizes a dry treatment in which the vaporized alkoxysilane or silazane is reacted with the external additive in the form of a cloud by stirring. Can be done. Further, a generally known treatment method such as a wet method in which the external additive is dispersed in a solvent and alkoxysilane or silazane is dropped and reacted can also be used.

As a result of further detailed examination using an external additive that satisfies the above conditions, it was found that it is not enough to devise the surface treatment of the external additive in order to suppress the filming on the drum. It was. The reason is not clear, but it is considered as follows.

As described above, the effect of using the external additive exhibiting low friction characteristics is to suppress the phenomenon that the block layer is drawn to the downstream side of the blade nip portion. As a result, while the block layer is stably maintained, the slipperiness between the external additives is also improved, so that the external agents are less likely to get caught, and the external agent rotates at high speed on the photoconductor drum. It ends up. Since the charge control agent surface-treated on the external additive is not chemically bonded to the surface of the external additive, the external additive keeps in contact with the photoconductor drum while rotating, so that the charge control agent gradually comes into contact with the photoconductor drum surface. It will be migrated and consumed. As a result, it was considered that filming was finally caused by the decrease in slipperiness of the block layer.

Therefore, the present inventors focused on the shape of the external additive and found that it was necessary to control the density of the external additive. That is, the external additive A used in the present invention needs to have a shape in which the average value of the density represented by the following formula (1) is 0.40 or more and 0.80 or less. The average value of the density is preferably 0.50 or more and 0.80 or less, and more preferably 0.60 or more and 0.75 or less.
Dense density = Area of external additive / Area of external additive surrounded by envelopes Equation (1)

The density is an index represented by the above formula (1), and is a value obtained by dividing the area of the external additive by the convex area of the external additive. The convex area is the area of the portion surrounded by the envelope created based on the contour of the target external additive. The density is an amount that is greater than 0 and takes a value of 1 or less, and the smaller the value, the more intricate the shape is. In other words, if the density value of the external additive used becomes small, the shape has many recesses, and the external additives are easily caught by each other and are difficult to roll. Therefore, even if they are sandwiched between the photoconductor drum and the blade, they do not rotate and easily stay in the nip. , I think that it is easy to form a stable block layer.

Further, the block layer is usually strongly pressed against the surface of the photoconductor drum by the pressure received from the blade nip portion, and accelerates the speed at which the charge control agent surface-treated by the external additive migrates to the surface of the photoconductor drum. I think there is. However, in the block layer formed of the external additive that satisfies the above range, the pressure received at the blade nip portion can be reduced due to the cavity provided by the concave portion of the external additive, and the friction is reduced, so that the charge control agent is consumed. I think that it also has the effect of suppressing. In addition, it is considered that good slipperiness can be maintained for a longer period of time by trapping and accumulating the charge control agent in which the recesses of the external additive migrate to the surface of the photoconductor drum and are consumed.

If the average density of the external additives is less than 0.40, there are too many recesses and the external additives are strongly entangled with each other, resulting in the generation of external additive aggregates causing filming on the photoconductor drum. It will promote. Further, when the average value of the density of the external additive is larger than 0.80, the number of recesses is reduced, so that the external additive easily rolls and filming on the drum occurs.

Incidentally, the aspect ratio conventionally used as an index of the shape of the external additive was insufficient to explain the above effect. This is because the aspect ratio is simply an index showing the length of the shape, and the elongated shape does not mean that the external additives are easily caught by each other.

The specific surface area of the inorganic fine particles used in the present invention is 30 m ² / g or more and 140 m ² / g or less. Further, it is preferably 40 m ² / g or more and 90 m ² / g or less.

If the specific surface area of the inorganic fine particles ^{is smaller than 30 m 2} / g, the contact area between the external additives becomes small, so that the block layer cannot be stably formed, and the filming on the photoconductor drum deteriorates. .. Further, when the specific surface area of the inorganic fine particles ^{is larger than 140 m 2} / g, it is difficult to uniformly treat the charge control agent, and good slipperiness cannot be obtained, so that the filming on the photoconductor drum is deteriorated.

As the external additive A used in the present invention, silica is preferably used because stable fluidity and chargeability can be obtained and fog can be suppressed. There are wet silica such as sedimentation method and sol-gel method, and dry silica such as explosive combustion method and fumed method. However, since it is easy to control the shape with many recesses, which is one of the features of the present invention, it should be dry silica. Is more preferable.

Dry silica is made from a silicon halogen compound or the like.

Silicon tetrachloride is used as the silicon halogen compound, but silanes such as methyltrichlorosilane and trichlorosilane can be used alone, or silicon tetrachloride and silanes can be mixed as a raw material.

After vaporizing the raw material, it reacts with water generated as an intermediate in an oxyhydrogen flame, that is, a so-called flame hydrolysis reaction to obtain the desired silica.

The method for producing the dry non-spherical silica used in the present invention will be described below.

After supplying oxygen gas to the burner and igniting the ignition burner, hydrogen gas was supplied to the burner to form a flame, and silicon tetrachloride, which is a raw material, was added to the burner to gasify it. Next, a flame hydrolysis reaction was carried out, and the produced silica powder was recovered.

The shape and shape of the external additive having many recesses can be arbitrarily adjusted by appropriately changing the silicon tetrachloride flow rate, the oxygen gas supply flow rate, the hydrogen gas supply flow rate, and the residence time of silica in the flame. As a means for controlling the shape having many recesses, the obtained silica powder may be transferred to an electric furnace, spread in a thin layer, and then heat-treated and sintered. By sintering, the coalescence strength of the external additive is increased, and the effect of suppressing drum scratches in the cleaning portion is more likely to be improved, which is preferable.

The amount of the external additive A added is not particularly limited as long as the desired characteristics can be obtained.

As a method for treating the surface of the external additive, for example, the charge control agent is dissolved in water or an organic solvent, and the solution is added dropwise or sprayed to the external additive, mixed, and then heat-treated. The surface treatment may be performed by removing water or an organic solvent. Thereby, the external additive A having the charge control agent treated on the surface can be obtained.

As a method for crushing the external additive A, for example, a crusher such as an atomizer (manufactured by Tokyo Atomizer Manufacturing Co., Ltd.) can be used. By arbitrarily adjusting the rotation speed of the crusher and the supply amount to the crusher, it is possible to control the density of the external additive A.

For charge control agents that are sparingly soluble in solvents and those that cannot be surface-treated with a single charge control agent, prepare a solution using a resin that is soluble in the solvent, and add the charge control agent to the solution. After mixing, it may be treated with an external additive.

Further, in the external additive A used in the present invention, when the specific surface area of the inorganic fine particles is X (m ² / g) and the amount treated by the charge control agent with respect to 100 parts by mass of the inorganic fine particles is Y (parts by mass). , A and B preferably satisfy the following formulas (2) and (3).
1 ≦ Y ≦ 30 (2)
Y / X ≤ 0.22 (3)

By setting the amount of treatment Y by the charge control agent to 1 or more, the surface of the inorganic fine particles can be easily treated, and good slipperiness can be obtained. Further, by setting the processing amount Y by the charge control agent to 30 or less, aggregates are less likely to be generated, and the generation of image streaks can be suppressed. In addition, when the external additive A satisfies the range of Y / X ≦ 0.22, aggregates are less likely to be generated, and the generation of image streaks can be suppressed.

In order for such an external additive A to form a block layer, the external additive needs to move from the toner surface to the surface of the photoconductor drum and be supplied between the photoconductor drum and the blade nip. As a method of measuring the state, as a result of diligent studies by the present inventors, toner is deposited on the surface of the polycarbonate thin film, the toner is sucked and removed, and the surface of the polycarbonate thin film is observed with a scanning electron microscope (SEM). It turned out that it can be measured by the method.

That is, in the method for measuring the adhesion of the polycarbonate thin film, the toner of the present invention has an amount of the external additive A adhering to the polycarbonate thin film of 0.1 area% or more when the area of the polycarbonate thin film is 100.0 area%. It is preferably 5.0 area% or less.

By setting the adhesion amount of the external additive A to 0.1 area% or more, the external additive A is stably supplied to the blade nip portion, so that the block layer can be easily formed. Further, by setting the adhering amount of the external additive A to 5.0 area% or less, it is possible to prevent the members of the charging roller from being contaminated due to the excessive supply of the external additive A and to suppress the occurrence of image streaks. The adhesion amount of the external additive A can be controlled by changing the external addition strength and the addition amount.

The method for producing the toner particles of the present invention is not particularly limited. As a method for producing a toner having a high circularity having good charging characteristics, a method for directly producing the toner in a hydrophilic medium such as a suspension polymerization method, an interfacial polymerization method, and a dispersion polymerization method (hereinafter, also referred to as a polymerization method). ), A method of forming the pulverized toner into a thermosphere, and the like.

Among them, a toner produced by a suspension polymerization method is preferable because the individual particles are substantially spherical and the distribution of the amount of charge is relatively uniform, so that the toner has high transferability.

In the suspension polymerization method, a polymerizable monomer composition having a polymerizable monomer, a colorant, a wax, etc. is dispersed in an aqueous medium to produce droplets of the polymerizable monomer composition. It is a manufacturing method for producing toner particles through a step and a polymerization step of polymerizing a polymerizable monomer in a droplet.

The toner of the present invention is preferably a toner having toner particles having at least a core portion and a shell portion. By adopting such a structure, it is possible to prevent poor charging and blocking due to exudation of the core portion to the surface of the toner particles. Further, it is more preferable that a surface layer portion having a resin composition different from that of the shell portion is present on the surface of the shell portion. The presence of this surface layer can further improve environmental stability, durability, and blocking resistance.

A vinyl-based polymerizable monomer can be mentioned as a preferable polymerizable monomer that can be used to generate the toner particles of the present invention. For example, styrene; styrene derivatives such as α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene; methylacrylate, ethylacrylate, n-propylacrylate, Acrylic polymerizable monomers such as iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, 2-ethylhexyl acrylate; methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, Methacrylate-based polymerizable monomers such as n-butyl methacrylate, iso-butyl methacrylate, and tert-butyl methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, vinyl benzoate , Vinyl esters such as vinyl acetate.

The shell portion is preferably formed of a resin such as polyester, styrene-acrylic copolymer, or styrene-methacrylic copolymer.

The toner of the present invention preferably contains wax. Wax components that can be used in the toner according to the present invention include paraffin wax, microcrystalline wax, petroleum-based wax such as petrolatum and its derivatives, Montan wax and its derivatives, hydrocarbon wax and its derivatives by the Fisher Tropsch method, polyethylene, and the like. Polyethylene waxes and derivatives thereof such as polypropylene, natural waxes such as carnauba wax and candelilla wax and derivatives thereof, and the derivatives include oxides, block copolymers with vinyl-based monomers, and graft-modified products. Furthermore, fatty acids such as higher fatty alcohols, stearic acid and palmitic acid, or compounds thereof, acid amide waxes and ester waxes can also be used.

Examples of the colorant used in the present invention include the following organic pigments, organic dyes, and inorganic pigments.

As the black colorant, carbon black, a magnetic material, and a black colorant using the following yellow / magenta / cyan colorants are used.

Examples of the yellow colorant include compounds typified by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds. Specifically, the following C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 73, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 128, 129, 138, 147, 150, 151, 154, 155, 168, 180, 185, 214 can be mentioned.

Examples of the magenta colorant include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds and perylene compounds. Specifically, the following C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221 238, 254, 269, C.I. I. Pigment Violet 19 can be mentioned.

Examples of the cyan colorant include a copper phthalocyanine compound and its derivative, an anthraquinone compound, and a basic dye lake compound. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66.

These colorants can be used alone or in the form of a solid solution. The colorant is selected in terms of hue angle, saturation, lightness, light resistance, OHP transparency, and dispersibility in toner. The amount of the colorant added is preferably 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer or the binder resin.

Further, the toner of the present invention can be made into a magnetic toner by containing a magnetic substance as a colorant. In this case, the magnetic material can also serve as a colorant. Magnetic materials include metals such as iron oxide such as magnetite, hematite and ferrite, iron, cobalt and nickel, or aluminum, copper, magnesium, tin, zinc, beryllium, calcium, manganese, selenium, titanium, tungsten, etc. Examples include alloys of metals such as vanadium and mixtures thereof. The magnetic material is preferably a surface-modified magnetic material. When the magnetic toner is prepared by a polymerization method, it is preferable that the magnetic toner is hydrophobized with a surface modifier which is a substance that does not inhibit polymerization. Examples of such a surface modifier include a silane coupling agent and a titanium coupling agent. The number average particle diameter of these magnetic materials is preferably 2.0 μm or less, and more preferably 0.1 μm or more and 0.5 μm or less. The amount contained in the toner particles is 20 parts by mass or more and 200 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer or the binder resin, and particularly preferably 40 parts by mass or more and 150 parts by mass with respect to 100 parts by mass of the binder resin. The part or less is good.

The average circularity of the toner is preferably 0.960 or more. If it is 0.960 or more, the fine line reproducibility is improved. Preferably, when the average circularity of the toner is 0.970 or more, the fine line reproducibility becomes better.

Further, as a production method for producing toner particles by the pulverization method, the following examples can be mentioned.

In the raw material mixing step, as a material constituting the toner particles, a binder resin, a colorant, other additives and the like are weighed in a predetermined amount, mixed and mixed. Examples of the mixing device include a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, an FM mixer, a Nauter mixer, a mechano hybrid (manufactured by Nippon Coke Industries, Ltd.) and the like.

Next, the mixed materials are melt-kneaded to disperse the colorant and the like in the binder resin. In the melt-kneading step, a batch-type kneader such as a pressure kneader or a Bambary mixer or a continuous-type kneader can be used. Single-screw or twin-screw extruders have become the mainstream because of their superiority in continuous production. For example, KTK type twin-screw extruder (manufactured by Kobe Steel), TEM type twin-screw extruder (manufactured by Toshiba Machine Co., Ltd.), PCM kneader (manufactured by Ikekai), twin-screw extruder (manufactured by KTK). , Co-kneader (manufactured by Bus Co., Ltd.), Kneedex (manufactured by Nippon Coke Industries Co., Ltd.), etc. Further, the resin composition obtained by melt-kneading may be rolled with two rolls or the like and cooled with water or the like in the cooling step.

Then, the cooled product of the resin composition is pulverized to a desired particle size in the pulverization step. In the crushing process, after coarse crushing with a crusher such as a crusher, a hammer mill, or a feather mill, further, for example, a cryptron system (manufactured by Kawasaki Heavy Industries), a super rotor (manufactured by Nisshin Engineering Co., Ltd.), and a turbo mill (Made by Freund Turbo Co., Ltd.) or an air jet type crusher to pulverize.

After that, if necessary, classification such as inertial classification type elbow jet (manufactured by Nittetsu Mining Co., Ltd.), centrifugal force classification method turboplex (manufactured by Hosokawa Micron Co., Ltd.), TSP separator (manufactured by Hosokawa Micron Co., Ltd.), faculty (manufactured by Hosokawa Micron Co., Ltd.) Classify using a machine or a sieving machine to obtain toner particles.

As a method for making toner particles spherical, after crushing, a hybridization system (manufactured by Nara Machinery Co., Ltd.), a mechanofusion system (manufactured by Hosokawa Micron Co., Ltd.), a faculty (manufactured by Hosokawa Micron Co., Ltd.), and Meteole Invo MR Type (Nippon Pneumatic Industries) (Manufactured by the company).

FM mixer (manufactured by Nippon Coke Industries Co., Ltd.), super mixer (manufactured by Kawata Co., Ltd.), Nobilta (manufactured by Hosokawa Micron Co., Ltd.), hybridizer (manufactured by Nara Machinery Co., Ltd.) ).

In addition, examples of the sieving device used for sieving coarse particles after external addition include the following. Ultrasonic (manufactured by Koei Sangyo Co., Ltd.); Resona Sheave, Gyroshifter (manufactured by Tokuju Kogyo Co., Ltd.); Vibrasonic System (manufactured by Dalton); Soniclean (manufactured by Shinto Kogyo Co., Ltd.); Turbo Screener (manufactured by Freund Turboe Co., Ltd.) ); Use a micro shifter (manufactured by Makino Sangyo Co., Ltd.).

Next, a method for measuring each physical property of the toner of the present invention will be described.

<Measurement method of the density of the external additive>
The density of the external additive was measured by using the polycarbonate thin film adhesion measurement method.

Each process of the polycarbonate thin film adhesion measurement method is shown in FIG. In FIG. 1, as a method of arranging the toner T on the substrate 12, a stainless mesh sieve 11 having a mesh opening of 75 μm is used. As a substrate, in order to simulate the surface layer of a photoconductor, polycarbonate (Iupilon Z-400, Mitsubishi Engineering Plastics Co., Ltd., viscosity average molecular weight (Mv) 40,000) was added to toluene on an aluminum sheet having a thickness of 50 μm in an amount of 10% by mass. It was dissolved so as to be a coating liquid. This coating liquid was applied to the aluminum sheet using a 50-count Meyer bar and dried at 100 ° C. for 10 minutes to prepare a sheet having a polycarbonate film thickness of 10 μm on the aluminum sheet.

This sheet was held by the substrate holder 13. The substrate was a square with a side of about 3 mm. About 10 mg of toner was put into the sieve, and the substrate was placed at a distance of 20 mm directly below the sieve. The opening of the sieve has a diameter of 10 mm so that the toner dropped from the sieve is efficiently deposited on the substrate.

A saw waveform vibration with an amplitude of 1 mm and a duty ratio of 33%, which corresponds to an acceleration of 5 G, was applied to the frame holding the sieve at 5 Hz in the in-plane direction of the sieve for 30 seconds to deposit toner on the substrate.

-Step of applying vibration to the substrate on which the toner is placed Next, a saw waveform vibration with an amplitude of 1 mm and a duty ratio of 33%, which is equivalent to an acceleration of 0.5 G on the substrate on which the toner is deposited, is applied at 3 Hz in the in-plane direction of the substrate for 20 seconds. The application promoted the contact between the substrate and the toner.

-Step of removing toner from the substrate As a suction means 14 on the substrate after applying vibration, an elastomer suction port with an inner diameter of about 5 mm connected to the tip of the nozzle of the vacuum cleaner is brought close to the substrate so that it is perpendicular to the toner placement surface. Remove the adhered toner. The toner was removed while visually checking the degree of residue. In this embodiment, the distance between the end of the suction port and the substrate is about 1 mm, and the suction time is about 3 seconds. The suction pressure at that time was 6 kPa.

-Step of quantifying the amount of the external additive supplied to the substrate When quantifying the amount and shape of the external additive A remaining on the substrate 12 after removing the toner, observation and image measurement with a scanning electron microscope are performed. Using. First, Pt was sputtered on the substrate after removing the toner at a current of 20 mA for 60 seconds to prepare a sample for observation. Next, in the observation with a scanning electron microscope, an observation magnification capable of observing the external additive of about 100 nm can be arbitrarily selected. As the scanning electron microscope, a Hitachi ultra-high resolution field emission scanning electron microscope S-4800 (Hitachi High Technologies America, Inc.) is used, and observation is performed with a reflected electron image of S-4800. The observation magnification depends on the particle size of the external additive, but for example, if it is around 100 nm, it can be observed under the conditions of 20000 times, an acceleration voltage of 10 kV, and an operating distance of 3 mm. The observation area at 20000 times is a region of about 30 μm × 20 μm.

Since the image obtained by observation shows the external additive at high brightness and the substrate at low brightness, the amount of the external additive in the visual field can be quantified by binarization. The binarization conditions can be appropriately selected depending on the observation device and the sputtering conditions. Here, image analysis software Image J (developed by Wayne Rasband) is used for binarization, and the background luminance distribution is removed from the Subtract Bakkround menu with a flattening radius of 40 pixels, and then binarized at a luminance threshold of 50. An example of the obtained binarized image is shown in FIG.

The obtained binarized image is subjected to particle analysis with the image analysis software Image J to calculate the amount of the external additive attached. The amount of adhesion was calculated by defining the area and shape from the particles of the binarized image. As for the area of the particles, among the high-intensity external additives in the observation field, ^{the particles having a shape of 0.005 μm 2} or more and 1.0 μm ² or less and a density of 0.40 or more and 0.80 or less are image analysis software. It is a value extracted by specifying in. With the image analysis software Image J, it is possible to specify the numerical range of the density by the name of Solidity.

The area of the particles calculated by defining the area and shape from the particles of the binarized image is the ratio of the external additive area to the entire visual field when the area of the polycarbonate thin film in the observation area is 100%. Using. The above measurement was performed on 100 binarized images, and the average value was taken as the amount of the external additive A adhered.

<Measurement method of specific surface area of inorganic fine particles>
The specific surface area of the inorganic fine particles is measured according to JIS Z8830 (2001). The specific measurement method is as follows.

As the measuring device, an "automatic specific surface area / pore distribution measuring device TriStar3000 (manufactured by Shimadzu Corporation)" that employs a gas adsorption method based on a constant volume method is used. The setting of measurement conditions and the analysis of measurement data are performed using the dedicated software "TriStar3000 Version 4.00" attached to this device, and a vacuum pump, nitrogen gas pipe, and helium gas pipe are connected to the device. Nitrogen gas is used as the adsorbed gas, and the value calculated by the BET multipoint method is used as the BET specific surface area in the present invention.

The BET specific surface area is calculated as follows.

First, nitrogen gas is adsorbed on the inorganic fine particles, and the equilibrium pressure P (Pa) in the sample cell at that time and the nitrogen adsorption amount Va (mol g ^-1 ) of the inorganic fine particles are measured. Then, the horizontal axis is the relative pressure Pr, which is the value obtained by dividing the equilibrium pressure P (Pa) in the sample cell by the saturated vapor pressure Po (Pa) of nitrogen, and the vertical axis is the nitrogen adsorption amount Va (mol g ^-1 ). Obtain the adsorption isotherm. ^{Next, the adsorption amount Vm (mol · g -1} ) of the single molecule layer, which is the adsorption amount required to form the single molecule layer on the surface of the inorganic fine particles, is obtained by applying the following BET formula.
Pr / Va (1-Pr) = 1 / (Vm × C) + (C-1) × Pr / (Vm × C)
(Here, C is a BET parameter, which is a variable that varies depending on the measurement sample type, adsorbed gas type, and adsorption temperature.)

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

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

Further, the BET specific surface area S (m ² · g ^-1 ) of the inorganic fine particles is calculated from the molecular occupied cross-sectional area (0.162 nm ^{2) of Vm and the nitrogen molecule calculated above based on the following formula.}
S = Vm x N x 0.162 x 10 ^-18
(Here, N is Avogadro's number (mol- ¹ ).)

The measurement using this device follows the "TriStar 3000 Instruction Manual V4.0" attached to the device, but specifically, the measurement is performed by the following procedure.

Weigh the tare of a special glass sample cell (stem diameter 3/8 inch, volume about 5 ml) that has been thoroughly washed and dried. Then, about 0.1 g of inorganic fine particles are put into this sample cell using a funnel.

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

Next, a dedicated "isothermal jacket" is attached to the stem portion of the sample cell containing the inorganic fine particles. Then, a dedicated filler rod is inserted into the sample cell, and the sample cell is set in the analysis port of the apparatus. The isothermal jacket is a tubular member having a porous material on the inner surface and an impermeable material on the outer surface, which can suck up liquid nitrogen to a certain level by capillarity.

Subsequently, the free space of the sample cell including the connecting device is measured. In the free space, the volume of the sample cell was measured using helium gas at 23 ° C., and then the volume of the sample cell after cooling the sample cell with liquid nitrogen was also measured using helium gas. Calculated by converting from the difference in volume. Further, the saturated vapor pressure Po (Pa) of nitrogen is automatically measured separately by using the Po tube built in the apparatus.

Next, after performing vacuum degassing in the sample cell, the sample cell is cooled with liquid nitrogen while continuing the vacuum degassing. Then, nitrogen gas is introduced stepwise into the sample cell to adsorb nitrogen molecules on the inorganic fine particles. At this time, since the above-mentioned adsorption isotherm is obtained by measuring the equilibrium pressure P (Pa) at any time, this adsorption isotherm is converted into a BET plot. The points of the relative pressure Pr for collecting data are set to a total of 6 points of 0.05, 0.10, 0.15, 0.25, 0.25, and 0.30. A straight line is drawn from the obtained measurement data by the method of least squares, and Vm is calculated from the slope and intercept of the straight line. Further, using this value of Vm, the BET specific surface area of the inorganic fine particles is calculated as described above.

<Measurement of weight average molecular weight (Mw)>
The weight average molecular weight (Mw) of the charge control resin is calculated by gel permeation chromatography (GPC) in terms of polystyrene. In the charge control resin having a sulfonic acid, the column elution rate also depends on the amount of the sulfonic acid group, so that the accurate molecular weight and the molecular weight distribution cannot be measured. Therefore, it is necessary to prepare a sample in which a sulfonic acid group is capped in advance. Methyl esterification is preferable for capping, and a commercially available methyl esterifying agent can be used. Specific examples thereof include a method of treating with trimethylsilyldiazomethane.

The molecular weight is measured by GPC as follows. A solution prepared by adding a charge control agent resin to THF (tetrahydrofuran) and allowing it to stand at room temperature for 24 hours is filtered through a solvent-resistant membrane filter "Mysholidisk" (manufactured by Tosoh Corporation) with a pore diameter of 0.2 μm to prepare a sample solution. Then, measure under the following conditions. In the sample preparation, the amount of THF is adjusted so that the concentration of the resin is 0.8% by mass. If the resin is difficult to dissolve in THF, a basic solvent such as DMF (N, N-dimethylformamide) can be used.
Equipment: HLC8120 GPC (Detector: RI) (manufactured by Tosoh Corporation)
Column: 7 stations of Shodex KF-801, 802, 803, 804, 805, 806, 807 (manufactured by Showa Denko KK)
Eluent: tetrahydrofuran (THF)
Flow velocity: 1.0 ml / min
Oven temperature: 40.0 ° C
Sample injection volume: 0.10 ml

In calculating the molecular weight of the sample, the molecular weight calibration curve prepared by using the standard polystyrene resin columns listed below is used. Specifically, the trade names "TSK Standard Polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F-10, F" manufactured by Toso Co., Ltd. -4, F-2, F-1, A-5000, A-2500, A-1000, A-500 ".

<Measurement of acid value>
The acid value is the number of mg of potassium hydroxide required to neutralize the acid contained in 1 g of the sample. The acid value of the charge control resin is measured according to JIS K 0070-1992, but specifically, it is measured according to the following procedure.

(1) Preparation of Reagents 1.0 g of phenolphthalein is dissolved in 90 ml of ethyl alcohol (95 vol%), and ion-exchanged water is added to make 100 ml to obtain a phenolphthalein solution.

Dissolve 7 g of special grade potassium hydroxide in 5 ml of water and add ethyl alcohol (95 vol%) to make 1 liter. Put it in an alkali-resistant container so as not to come into contact with carbon dioxide, leave it for 3 days, and then filter it to obtain a potassium hydroxide solution. The obtained potassium hydroxide solution is stored in an alkali-resistant container. The factor of the potassium hydroxide solution was that 25 ml of 0.1 mol / l hydrochloric acid was placed in a triangular flask, several drops of the phenolphthaline solution were added, titrated with the potassium hydroxide solution, and the hydroxylation required for neutralization was performed. Obtained from the amount of potassium solution. As the 0.1 mol / l hydrochloric acid, those prepared according to JIS K 8001-1998 are used.

(2) Operation (A) Main test 2.0 g of the sample is precisely weighed in a 200 ml Erlenmeyer flask, 100 ml of a mixed solution of toluene / ethanol (2: 1) is added, and the mixture is dissolved over 5 hours. Then, a few drops of the phenolphthalein solution are added as an indicator, and titration is performed using the potassium hydroxide solution. The end point of the titration is when the light red color of the indicator continues for about 30 seconds.

(B) Blank test Titration is performed in the same manner as described above except that no sample is used (that is, only a mixed solution of toluene / ethanol (2: 1) is used).

(3) Substitute the obtained result into the following formula to calculate the acid value.
A = [(CB) x f x 5.61] / S

Here, A: acid value (mgKOH / g), B: addition amount of potassium hydroxide solution in blank test (ml), C: addition amount of potassium hydroxide solution in this test (ml), f: potassium hydroxide Solution factor, S: sample (g).

<Measuring method of average circularity>
The average circularity of the toner is measured by the flow type particle image analyzer "FPIA-3000" (manufactured by Sysmex Corporation) under the measurement and analysis conditions at the time of calibration work.

The specific measurement method is as follows. First, about 20 ml of ion-exchanged water from which impure solids and the like have been removed in advance is placed in a glass container. Among them, as a dispersant, "Contaminone N" (a 10% by mass aqueous solution of a neutral detergent for cleaning a precision measuring instrument with a pH of 7 consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd. ) Is diluted about 3 times by mass with ion-exchanged water, and about 0.2 ml of the diluted solution is added. Further, about 0.02 g of the measurement sample is added, and the dispersion treatment is performed for 2 minutes using an ultrasonic disperser to prepare a dispersion liquid for measurement. At that time, the dispersion is appropriately cooled so that the temperature of the dispersion is 10 ° C. or higher and 40 ° C. or lower. As the ultrasonic disperser, a desktop ultrasonic cleaner disperser (for example, "VS-150" (manufactured by Vervocrea)) having an oscillation frequency of 50 kHz and an electrical output of 150 W is used, and a predetermined amount is contained in the water tank. Ion-exchanged water is added, and about 2 ml of the contaminanton N is added into the water tank.

For the measurement, the flow type particle image analyzer equipped with "UPlanApro" (magnification 10 times, numerical aperture 0.40) was used as the objective lens, and the particle sheath "PSE-900A" (manufactured by Sysmex) was used as the sheath liquid. It was used. The dispersion liquid adjusted according to the above procedure is introduced into the flow type particle image analyzer, and 3000 toner particles are measured in the total count mode in the HPF measurement mode. Then, the binarization threshold value at the time of particle analysis is set to 85%, the diameter of the analyzed particle is limited to 1.985 μm or more and less than 39.69 μm, and the average circularity of the toner particles is obtained.

In the measurement, automatic focus adjustment is performed using standard latex particles (for example, "RESAARCH AND TEST PARTICLES Latex Microsphere Suspensions 5200A" manufactured by Duke Scientific Co., Ltd. diluted with ion-exchanged water) before the start of the measurement. After that, it is preferable to perform focus adjustment every 2 hours from the start of measurement.

In the embodiment of the present application, a flow-type particle image analyzer for which a calibration work was performed by Sysmex Corporation and a calibration certificate issued by Sysmex Corporation was issued was used. The measurement was performed under the measurement and analysis conditions at the time of receiving the calibration certificate, except that the diameter of the analysis particle was limited to the equivalent circle diameter of 1.985 μm or more and less than 39.69 μm.

Hereinafter, the present invention will be specifically described based on Examples. However, this does not limit any embodiment of the present invention. The number of copies in the examples is parts by mass.

<Production example of charge control agent (for fine particle A surface treatment)>
<Manufacturing example of CCA1>
A 3 L flask equipped with a stirrer, a condenser, a thermometer, and a nitrogen introduction tube is charged with 1000 parts of pure water and 4 parts of sodium dodecyl sulfate as an emulsifier, and nitrogen substitution is performed for 30 minutes. Add 2 parts of potassium persulfate (KPS) and stir to dissolve. The contents are heated to 80 ° C. with nitrogen introduced. When the temperature reaches 80 ° C., 300 parts of styrene, 60 parts of -2-ethylhexyl acrylate (2-EHA) and 40 parts of 2-acrylamide-2-methylpropanesulfonic acid (AMPS) are added to 600 parts of pure water. The dissolved aqueous solution is added dropwise separately over 2 hours. Then, polymerization was carried out at 80 ° C. for 8 hours to obtain an emulsion solution. The emulsion solution was dried in a vacuum dryer at 50 ° C. until the water content became 1% or less to obtain CCA1 which is a styrene / 2-EHA / AMPS copolymer. The physical characteristics of this CCA1 are shown in Table 1.

<Manufacturing example of CCA2 to CCA5>
In the production example of CCA1, the amount of the monomer used was changed according to Table 2, and CCA2 to CCA5 were produced while controlling the molecular weight by adjusting the polymerization temperature and the polymerization time. The physical characteristics of CCA2 to CCA5 are shown in Table 1.

<Manufacturing example of CCA6>
18 parts of 2,4-dihydroxybenzoic acid was dissolved in 150 parts of methanol, 36.9 parts of potassium carbonate was added, and the mixture was heated to 65 ° C. A mixed solution of 18.7 parts of 4- (chloromethyl) styrene and 100 parts of methanol was added dropwise to this reaction solution, and the mixture was reacted at 65 ° C. for 3 hours. The reaction mixture was cooled, filtered, and the filtrate was concentrated to obtain a crude product. The crude product was dispersed in 1500 parts of water having a pH of 2, and ethyl acetate was added for extraction. Then, it was washed with water, dried over magnesium sulfate, and ethyl acetate was distilled off under reduced pressure to obtain a precipitate. The precipitate was washed with hexane and then purified by recrystallization from toluene and ethyl acetate to obtain a vinyl monomer represented by the chemical formula (6).

Next, 13.1 part of the vinyl monomer represented by the chemical formula (6) and 81.9 parts of styrene were dissolved in 42.0 parts of toluene, stirred for 1 hour, and then heated to 110 ° C. A mixed solution of 3.0 parts of tert-butylperoxyisopropyl monocarbonate (manufactured by NOF CORPORATION, trade name: Perbutyl I) and 42 parts of toluene was added dropwise to this reaction solution. The reaction was further carried out at 110 ° C. for 4 hours. Then, it was cooled and added dropwise to 1000 parts of methanol to obtain a precipitate. The obtained precipitate was dissolved in 120 parts of THF and then added dropwise to 1800 parts of methanol to precipitate a white precipitate, which was filtered and dried at 90 ° C. under reduced pressure to obtain styrene and a vinyl chloride represented by the chemical formula (6). CCA6, which is a copolymer with a metric, was obtained. The physical characteristics of this CCA6 are shown in Table 1.

<CCA7>
T-77 (manufactured by Hodogaya Chemical Co., Ltd .; metal-containing azo dye) was used.

<Production example of inorganic fine particles>
<Production example of inorganic fine particles 1>
After supplying oxygen gas to the burner and igniting the ignition burner, hydrogen gas was supplied to the burner to form a flame, and silicon tetrachloride, which is a raw material, was added to the burner to gasify it to obtain silica fine particles. .. Specifically, the amount of silicon tetrachloride gas as the raw material is 150 kg / hr, the amount of hydrogen gas 50 Nm ³ / hr and the amount of oxygen gas 30 Nm ³ / hr, the silica concentration in the flame is ^{0.50 kg / Nm 3,} and the residence time is 0.020 sec. And said. The obtained silica fine particles were transferred to an electric furnace, spread in a thin layer, and then heat-treated at 700 ° C. for sintering and agglomeration to obtain inorganic fine particles 1. Table 3 shows the physical characteristics of the inorganic fine particles 1.

<Production examples of inorganic fine particles 2-7, 9, and 10>
Inorganic fine particles 2 to 7, 9 and 10 were obtained by adjusting the amount of silicon tetrachloride, the amount of oxygen gas, the amount of hydrogen gas, the silica concentration, the residence time, and the sintering conditions. Table 3 shows the physical characteristics of the inorganic fine particles 2 to 7, 9, and 10.

<Inorganic fine particles 8>
Alumina particles having a specific surface area of 81 m ² / g were prepared.

<Production example of external additive A>
<Production example of external additive A-1>
As the first treatment step, 15.0 parts of hexamethyldisilazane (hereinafter, also referred to as HMDS) was sprayed inside 1100 parts of the inorganic fine particles, and the silane compound was treated in a fluidized state of silica. After continuing this reaction for 60 minutes, the reaction was terminated.

As the second treatment step, the silica fine particles produced in the first treatment step were sprayed with a solution prepared by dissolving 5 parts of the charge control agent CCA1 in toluene, and the CCA1 was immobilized by stirring and mixing for 2 hours. Then, it was heat-treated at 200 ° C. to volatilize toluene to obtain an inorganic fine particle 1 / HMDS / CCA1 complex having CCA1 on its surface. Next, the obtained inorganic fine particle 1 / HMDS / CCA1 composite was crushed by a pulverizer atomizer TAP-1W (manufactured by Tokyo Atomizer Manufacturing Co., Ltd.), and the shape of the external additive A-1 was controlled. Obtained. The rotation speed of the crusher is 4000 rpm, and the amount supplied to the crusher is 5 kg / h. Table 4 shows the physical characteristics of the obtained external preparation A-1.

<Production examples of external additives A-2 to A-18, A-20, and A-24>
External preparations A-2 to A-2 to the same as in the production example of external preparation A-1, except that the combination of inorganic fine particles, silane or silazane compound, charge control agent, and crushing conditions were changed as shown in Table 4. A-18, A-20, and A-24 were obtained. Table 4 shows the physical characteristics of the obtained external additives A-2 to A-18, A-20, and A-24.

<Production example of external additive A-19>
As the first treatment step, 15.0 parts of HMDS was sprayed inside 2100 parts of the inorganic fine particles, and the silane compound was treated in a fluidized state of silica. After continuing this reaction for 60 minutes, the reaction was terminated.

As the second treatment step, 5 g of polyester resin (terephthalic acid-propylene oxide-modified bisphenol A (2 molar adduct) copolymer (molecular ratio = 51: 50), acid value 10 mgKOH / g, glass transition point 70 ° C., weight A dispersion solution of CCA7 was prepared by dissolving 10500 average molecular weight (Mw) and 3.2) weight average molecular weight (Mw) / number average molecular weight (Mn) 3.2) in toluene and further mixing 5 g of CCA7. The obtained dispersion solution was sprayed on the silica fine particles produced in the first treatment step, and CCA7 was immobilized by stirring and mixing for 2 hours. Then, it was heat-treated at 200 ° C. to volatilize toluene to obtain an inorganic fine particle 2 / HMDS / CCA7 complex having CCA7 on its surface. The crushing step was carried out by changing the conditions shown in Table 4 to obtain an external additive A-19. Table 4 shows the physical characteristics of the obtained external additive A-19.

<Production example of external additive A-21>
As the first treatment step, 100 parts of the inorganic fine particles were sprayed with a solution prepared by dissolving 5 parts of the charge control agent CCA1 in toluene, and CCA1 was immobilized by stirring and mixing for 2 hours. Then, heat treatment was performed at 200 ° C. to volatilize toluene, and surface treatment with CCA1 was performed.

As the second treatment step, 15.0 parts of HMDS was sprayed inside the silica fine particles produced in the first treatment step, and the silane compound was treated in a fluidized state of silica. After continuing this reaction for 60 minutes, the reaction was terminated to obtain an inorganic fine particle 2 / CCA1 / HMDS composite having CCA1 on the surface. The crushing step was carried out by changing the conditions shown in Table 4 to obtain an external additive A-21. Table 4 shows the physical characteristics of the obtained external preparation A-21.

<Production example of external additive A-22>
A solution prepared by dissolving 15.0 parts of HMDS and 5 parts of the charge control agent CCA1 in toluene was simultaneously sprayed on 100 parts of 2100 inorganic fine particles, and CCA1 was immobilized and treated with a silane compound by stirring and mixing for 2 hours. It was. Then, it was heat-treated at 200 ° C. to volatilize toluene to obtain an inorganic fine particle 2 / CCA1 / HMDS composite having CCA1 on its surface. The crushing step was carried out by changing the conditions shown in Table 4 to obtain an external additive A-22. Table 4 shows the physical characteristics of the obtained external additive A-22.

<Production example of external additive A-23>
A solution prepared by dissolving 5 parts of the charge control agent CCA1 in toluene was sprayed on 100 parts of 2100 parts of the inorganic fine particles, and CCA1 was immobilized by stirring and mixing for 2 hours. Then, it was heat-treated at 200 ° C. to volatilize toluene to obtain an inorganic fine particle 2 / CCA1 composite having CCA1 on the surface. The crushing step was carried out by changing the conditions shown in Table 4 to obtain an external additive A-23. Table 4 shows the physical characteristics of the obtained external preparation A-23.

<Manufacturing example of toner particles>
710 parts of ion-exchanged water and _{850 parts of a 0.1 mol / liter Na 3} PO ₄ aqueous solution were added to the four-mouthed container, and the high-speed agitator T.I. K. The temperature was maintained at 60 ° C. while stirring at 12,000 rpm using a homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.). 68 parts of a 1.0 mol / liter-CaCl ₂ aqueous solution was gradually added thereto to prepare an aqueous dispersion medium containing fine calcium phosphate.

Styrene 124 parts n-butyl acrylate 36 parts Copper phthalocyanine pigment (Pigment Blue 15: 3) 13 parts Polyester resin (terephthalic acid-propylene oxide modified bisphenol A (2 molar adduct) copolymer (molar ratio = 51: 50) , Acid value 10 mgKOH / mg, glass transition point 70 ° C., Mw 10500, Mw / Mn 3.2) 10 parts load electrical control agent (aluminum compound of 3,5-di-tert-butylsalicylic acid) 0.8 parts Fisher Tropschwax (heat absorption main peak temperature 78 ° C) 15 parts The above materials are stirred using an attritor (manufactured by Nippon Coke Industries Co., Ltd.) for 3 hours to disperse each component in a polymerizable monomer, and a monomer mixture. Was prepared. To the monomer mixture, 20.0 parts (50% of toluene solution) of 1,1,3,3-tetramethylbutylparoxy2-ethylhexanoate as a polymerization initiator was added, and the polymerizable monomer was added. The composition was prepared. The polymerizable monomer composition was put into the aqueous dispersion medium, and granulated for 5 minutes while maintaining the rotation speed of the stirrer at 10,000 rpm. Then, the high-speed stirrer was changed to a propeller-type stirrer, the internal temperature was raised to 70 ° C., and the reaction was carried out for 6 hours with slow stirring.

Next, the inside of the container was heated to a temperature of 80 ° C. and maintained for 4 hours, and then cooled to obtain slurry 1. Dilute hydrochloric acid was added to the container containing the slurry 1 to remove the dispersion stabilizer. Further, it was filtered, washed, and dried to obtain polymer particles (toner particles 1) having a weight average particle diameter (D4) of 6.2 μm. The average circularity of the toner particles 1 was 0.980.

[Example 1]
With respect to 100 parts of the obtained toner particles, 0.5 part of the external additive A-1 and the external agent B (the number average particle diameter (D1) of the primary particles is 9 nm, and the specific surface area is 215 m ² / g). Silica fine powder) 1.0 part was added. These materials were externally mixed by FM10C (manufactured by Nippon Coke Industries Co., Ltd.). The external addition conditions were as follows: the amount of toner particles charged was 1.8 kg, the rotation speed was 3600 rpm, and the external addition time was 5 minutes. Then, it was sieved with a mesh having a mesh size of 100 μm to obtain a negative triboelectric toner 1. Table 5 shows the physical characteristics of the obtained toner 1.

The following evaluation was performed using the obtained toner.

<Test>
The HP Laser Beam Printer HP Color LaserJet Enterprise M651n was used with the process speed modified to 400 mm / s in consideration of further speeding up and extending the life of the printer in the future. As the evaluation paper, CS-680 sold by Canon Marketing Japan was used. The evaluation of the filming on the drum was performed at a low printing ratio (1%). As a result, the amount of the external additive A supplied to the cleaning nip portion is reduced, which is a strict condition for the filming property on the drum.

<Filming on the photoconductor drum>
The filming on the photoconductor drum was evaluated visually and by image on the surface of the photoconductor drum. Printing in low-temperature and low-humidity environment (temperature 15 ° C: relative humidity 30%), normal temperature room environment (temperature 25 ° C: relative humidity 60%), and high-temperature and high-humidity environment (temperature 32 ° C: relative humidity 80%). The operation of outputting an image having a ratio of 1% was repeated, and each time the number of output sheets reached 500, the mixture was left overnight. Then, the process of outputting 500 images and leaving them to stand overnight was repeated as described above, and finally 5000 images were output. After that, five halftone images were continuously output, and the output images and the state of the surface of the photoconductor drum were evaluated according to the following criteria. A and B ranks were accepted.
A: No image defects or deposits on the surface of the photoconductor drum are observed.
B: No image defects are observed, but slight deposits are observed on the surface of the photoconductor drum.
C: Minor white spots (1 to 3 on average) can be seen on the image.
D: White spots (4 or more on average) can be seen on the image.

<Evaluation of fog>
In a high-temperature and high-humidity environment (temperature 32 ° C., relative humidity 80%), the operation of outputting an image having a printing ratio of 1% was repeated, and each time the number of output sheets reached 500, the image was left overnight. Then, the process of outputting 500 images and leaving them to stand overnight was repeated as described above, and finally 5000 images were output and evaluated by the following method.

In the above image output test, one image having a white background portion was output each time. After that, for the image having all the white background parts, the fog is obtained from the difference between the whiteness of the white background part of the image having the white background part (reflectance Ds (%)) and the whiteness of the transfer paper (average reflectance Dr (%)). The concentration (%) (= Dr (%) −Ds (%)) was calculated. The whiteness was measured by "REFLECTMER MODEL TC-6DS" (manufactured by Tokyo Denshoku Co., Ltd.). As the filter, an amber light filter was used. The ones with the worst fog were ranked as follows. A and B ranks were accepted.
A: The fog concentration is less than 1.0%.
B: The fog concentration is 1.0% or more and less than 2.0%.
C: The fog concentration is 2.0% or more and less than 3.0%.
D: The fog concentration is 3.0% or more.

<White streaks in a solid image on the entire surface (white streaks in a solid image)>
From the viewpoint of image quality, solid image white streaks were evaluated. After outputting 5000 images in the above image output, the power of the image forming apparatus was turned off and left for 1 week. After that, the image forming apparatus was restarted, and one chart having a solid image portion formed on the entire surface of the printing paper was output and evaluated according to the following criteria. A and B ranks were accepted.
A: No white streaky vertical lines can be seen on the image.
B: White streaky vertical lines are thinly seen on the image.
C: 1 to 3 clear white streaky vertical lines can be seen on the image.
D: Four or more clear white streaky vertical lines can be seen on the image.

[Examples 2 to 23]
Toners 2 to 23 were obtained in the same manner as in Example 1 except that the external preparations and external conditions shown in Table 5 were used. The physical characteristics of the toner are as shown in Table 5.

Table 6 shows the results of evaluation in the same manner as in Example 1.

[Comparative Examples 1 to 5]
Toners 24 to 28 were obtained in the same manner as in Example 1 except that the external preparations and external conditions shown in Table 5 were used. The physical characteristics of the toner are as shown in Table 5.

Table 6 shows the results of evaluation in the same manner as in Example 1.

T ... toner, A ... external additive, 11 ... sieve, 12 ... substrate, 13 ... substrate holder, 14 ... suction means

Claims (9)

A toner having toner particles containing a binder resin and a colorant and an external additive A.
The external preparation A is
i) It has a shape with a density of 0.40 or more and 0.80 or less represented by the following formula (1).
Dense density = Area of external additive / Area of external additive surrounded by envelopes Equation (1)
ii) An external additive obtained by treating the surface of inorganic fine particles with a silane or silazane compound and then treating with a charge control agent.
iii) A toner characterized in that the specific surface area of the inorganic fine particles is 30 m ² / g or more and 140 m ^{2 / g or less.} In the polycarbonate thin film adhesion measurement method, the amount of the external additive A adhering to the polycarbonate thin film is 0.1 area% or more and 5.0 area% or less when the area of the polycarbonate thin film is 100.0 area%. The toner according to claim 1. When the specific surface area of the inorganic fine particles is X (m ² / g) and the amount treated by the charge control agent with respect to 100 parts by mass of the inorganic fine particles is Y (parts by mass), the X and Y are the following formula (2). ) And (3). The toner according to claim 1 or 2.
1 ≦ Y ≦ 30 (2)
Y / X ≤ 0.22 (3) The toner according to any one of claims 1 to 3, wherein the charge control agent is a charge control resin, and the weight average molecular weight (Mw) of the charge control resin is 1000 or more and 300,000 or less. The toner according to claim 4, wherein the acid value of the charge control resin is 15 mgKOH / mg or more and 35 mgKOH / mg or less. The toner according to claim 4 or 5, wherein the charge control resin has a partial structure derived from salicylic acid and / or a sulfonic acid group or a sulfonic acid base. Any one of claims 4 to 6, wherein the charge control resin is a resin having a partial structure represented by the following formula (4) and / or a partial structure derived from 2-acrylamide-2-methylpropanesulfonic acid. Toner described in.

(In the formula, R ¹ represents a hydroxy group, a carboxy group, an alkyl group having 1 or more and 18 or less carbon atoms, or an alkoxy group having 1 or more and 18 or less ^{carbon atoms, and R 2} is a hydrogen atom, a hydroxy group, or a carbon number of carbon atoms. It represents an alkyl group of 1 or more and 18 or less, or an alkoxy group having 1 or more and 18 or less carbon atoms, g represents an integer of 1 or more and 3 or less, h represents an integer of 0 or more and 3 or less, and h represents 2 or 3. In this case, R ¹ can be selected independently.) A toner having toner particles containing a binder resin and a colorant and an external additive A.
The external preparation A is
i) It has a shape with a density of 0.40 or more and 0.80 or less represented by the following formula (1).
Dense density = Area of external additive / Area of external additive surrounded by envelopes Equation (1)
ii) After surface treatment with a silane or silazane compound, a metal compound of aromatic carboxylic acid, a metal compound of azo dye or azo pigment, a polymer compound having a sulfonic acid group or a carboxylic acid group as a substituent, a urea compound, or calix. It is an external preparation obtained by treating with a compound selected from the group consisting of an arene, a quaternary ammonium salt, a polymer compound having a quaternary ammonium salt in a side chain, a guanidine compound, a niglosin compound, and an imidazole compound. ,
iii) A toner characterized in that the specific surface area of the inorganic fine particles is 30 m ² / g or more and 140 m ^{2 / g or less.} An external preparation obtained by surface-treating with a silane or silazane compound and then treating with a compound selected from the group consisting of a monoazo metal compound, a sulfonic acid group or a polymer compound having a carboxylic acid group as a substituent. The toner according to claim 8.

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