JP6915571B2 - Manufacturing method of positively charged toner and positively charged toner - Google Patents

Description

The present invention relates to a positively charged toner and a method for producing a positively charged toner.

It has been proposed to attach an external additive to the surface of the toner matrix particles for the purpose of improving the fluidity and charging characteristics of the toner. For example, the two-component developer described in Patent Document 1 includes toner particles, resin fine particles as an external additive, inorganic fine particles as an external additive, and carriers.

Japanese Unexamined Patent Publication No. 2008-257095

However, it has been found by the study of the present inventor that the two-component developer described in Patent Document 1 has room for improvement in terms of charge stability of toner particles.

The present invention has been made in view of the above problems, and an object of the present invention is a positively charged toner having excellent charge stability even when images are continuously formed in a high temperature and high humidity environment, and positively charged. It is to provide a method of manufacturing a sex toner.

The positively charged toner according to the present invention contains toner particles. The toner particles include a toner mother particle and an external additive provided on the surface of the toner mother particle. The external additive contains resin particles. The resin particles and the toner mother particles are covalently bonded to each other.

The method for producing a positively charged toner according to the present invention includes an external addition step and a bonding step. In the external addition step, an external additive containing resin particles is attached to the surface of the toner matrix particles. In the bonding step, the resin particles and the toner mother particles are covalently bonded to each other to form toner particles.

The positively charged toner according to the present invention is excellent in charge stability even when images are continuously formed in a high temperature and high humidity environment. The positively charged toner produced by the production method according to the present invention is excellent in charge stability even when images are continuously formed in a high temperature and high humidity environment.

It is a figure which shows an example of the cross-sectional structure of the toner particle contained in the toner which concerns on embodiment of this invention. It is a figure which shows an example of the cross-sectional structure of the toner particle contained in the toner in the 1st aspect of the Embodiment of this invention. It is a figure which shows an example of the cross-sectional structure of the toner particle contained in the toner in the 2nd aspect of the Embodiment of this invention. In the first aspect of the embodiment of the present invention, it is a figure which shows typically an example of the reaction between a resin core and a material for forming a coat layer. It is a figure which shows typically an example of the reaction of a resin particle and a toner mother particle in the 1st aspect of the Embodiment of this invention. FIG. 5 is a diagram schematically showing an example of a reaction between a toner core and a material for forming a shell layer in the second aspect of the embodiment of the present invention. It is a figure which shows typically an example of the reaction of a resin particle and a toner mother particle in the 2nd aspect of the Embodiment of this invention. It is a figure which shows an example of the reaction apparatus used in a bonding process.

First, the meanings of the terms used in the present specification and the measurement method will be described. Unless otherwise specified, the evaluation results (values indicating shape or physical properties, etc.) of powders (more specifically, toner matrix particles, toner cores, external additives, resin particles, resin cores, toner, etc.) must be specified. It is the number average of the values measured for a considerable number of particles contained in the powder.

Unless otherwise specified, each of the particle size of the powder and the number average primary particle size is the equivalent circle diameter of the primary particles measured using a microscope (Haywood diameter: a circle having the same area as the projected area of the particles). It is the number average value of).

The volume median diameter (D ₅₀ ) of the powder was measured based on the Coulter principle (pore electrical resistance method) using "Coulter Counter Multisizer 3" manufactured by Beckman Coulter Co., Ltd., unless otherwise specified. The value. Hereinafter, the "median volume diameter" may be described _{as "D 50".}

Unless otherwise specified, the glass transition point (Tg) and melting point (Mp) are "JIS (Japanese Industrial Standards) K7121-" using a differential scanning calorimeter ("DSC-6220" manufactured by Seiko Instruments Inc.). It is a value measured according to "2012". In the heat absorption curve (vertical axis: heat flow (DSC signal), horizontal axis: temperature) of the sample measured by the differential scanning calorimeter, the temperature of the inflection point due to the glass transition corresponds to the glass transition point (Tg). .. The temperature of the inflection point due to the glass transition is, in particular, the temperature of the intersection of the baseline extrapolation line and the falling line extrapolation line. The temperature of the maximum endothermic peak in the endothermic curve corresponds to the melting point (Mp). Hereinafter, the "glass transition point" may be described as "Tg" and the "melting point" may be described as "Mp".

The softening point (Tm) is a value measured using an heightened flow tester (“CFT-500D” manufactured by Shimadzu Corporation) unless otherwise specified. In the S-curve (horizontal axis: temperature, vertical axis: stroke) of the sample measured by the heightened flow tester, the temperature at which "(baseline stroke value + maximum stroke value) / 2" is the softening point (Tm). ) Corresponds to. Hereinafter, the "softening point" may be described as "Tm".

Unless otherwise specified, each of the acid value and the hydroxyl value is a value measured according to "JIS (Japanese Industrial Standards) K0070-1992".

Each of the number average molecular weight (Mn) and the mass average molecular weight (Mw) is a value measured by gel permeation chromatography unless otherwise specified. Hereinafter, the "number average molecular weight" may be described as "Mn" and the "mass average molecular weight" may be described as "Mw".

The strength of chargeability is the ease of triboelectric charging with respect to the standard carrier provided by the Imaging Society of Japan, unless otherwise specified. For example, the toner is triboelectrically charged by mixing it with a standard carrier (anionic: N-01, cationic: P-01) provided by the Imaging Society of Japan and stirring it. For example, using KFM (Kelvin probe force microscope), the surface potential of the measurement target before and after triboelectric charging is measured, and the larger the change in potential before and after triboelectric charging, the stronger the chargeability. show.

Hereinafter, the compound and its derivative may be collectively referred to by adding "system" after the compound name. When the polymer name is represented by adding "system" after the compound name, it means that the repeating unit of the polymer is derived from the compound or its derivative. In addition, acrylics and methacryl may be collectively referred to as "(meth) acrylics". The meanings of the terms used in the present specification and the measurement method have been described above. Next, an embodiment of the present invention will be described.

[toner]
The present embodiment relates to a positively charged toner (hereinafter, may be referred to as toner). The toner contains toner particles. Toner is an aggregate (powder) of toner particles.

FIG. 1 shows an example of the cross-sectional structure of the toner particles 10 contained in the toner of the present embodiment. The toner particles 10 shown in FIG. 1 include a toner mother particle 11 and an external additive. The external additive is provided on the surface of the toner matrix particles 11. The external additive contains resin particles 12. The resin particles 12 and the toner mother particles 11 are covalently bonded to each other. The covalent bond is, for example, an amide bond.

The toner of this embodiment is excellent in charge stability. The charge stability of the toner is a characteristic that the charge amount of the toner can be maintained within a desired range when images are continuously formed by using the toner. In the toner of the present embodiment, the resin particles 12 and the toner mother particles 11 are covalently bonded to each other. By covalently bonding to each other, the resin particles 12 are less likely to be separated from the toner mother particles 11. Therefore, fluctuations in the amount of charge of the toner caused by the detachment of the resin particles 12 can be suppressed. As a result, the charge amount of the toner can be maintained within a desired range, and the charge stability of the toner can be improved.

Further, according to the toner having excellent charge stability, the amount of toner scattered can be suppressed to a desired value or less. The amount of toner scattered will be described by taking as an example the case of developing with a two-component developer in which toner and carriers are mixed. In image formation, toner adheres to the surface of the carrier due to electrostatic force. When the charge amount of the toner is lower than the charge amount in the desired range, the electrostatic adhesive force between the toner and the carrier is reduced. In the development process of image formation, carriers to which toner is attached are pumped up to the surface of a developing unit (for example, a developing roller). The carrier to which the toner is attached rotates according to the rotation of the developing unit while adhering to the surface of the developing unit. At this time, the toner having a reduced electrostatic adhesive force is detached from the carrier. The toner desorbed from the carrier adhering to the surface of the developing unit falls from the developing unit and collects in a container located below the developing unit. The amount of toner accumulated in the container is the amount of toner scattered. Since the toner of the present embodiment has excellent charge stability, the electrostatic adhesive force between the toner and the carrier is unlikely to decrease, and the amount of toner scattered can be suppressed to a desired value or less.

An example of the toner of this embodiment is as follows. One of the toner mother particles 11 and the resin particles 12 contains the first vinyl resin. The other of the toner mother particles 11 and the resin particles 12 has a carboxyl group on its surface. The first vinyl resin contains a unit represented by the following formula (A) and a unit represented by the following formula (B). Hereinafter, the "unit represented by the formula (A)" and the "unit represented by the formula (B)" may be described as the unit (A) and the unit (B), respectively. The covalent bond that binds the resin particles 12 and the toner mother particles 11 to each other is a first amide bond. The first amide bond is an amide bond contained in the unit (B).

In formula (A), R ¹ represents a hydrogen atom or an optionally substituted alkyl group. Examples of the alkyl group include a linear alkyl group, a branched chain alkyl group, and a cyclic alkyl group. The ^{alkyl group represented by R 1} may be substituted with a substituent. Examples of such a substituent include a phenyl group. R ¹ preferably represents a hydrogen atom or an alkyl group, more preferably represents a hydrogen atom, a methyl group, an ethyl group, or an isopropyl group, and further preferably represents a hydrogen atom.

In formula (B), R ¹ represents the same group as ^{R 1} in formula (A). When the resin particles 12 contain the first vinyl resin, R ² represents an atom constituting the toner mother particles 11. When the toner mother particles 11 contain the first vinyl resin, R ² represents the atoms constituting the resin particles 12.

When the resin particles 12 contain the first vinyl resin, the oxazoline group of some of the units (A) in the first vinyl resin is used as the carboxyl group on the surface of the toner mother particles 11. To react with. Thereby, the unit (B) can be further contained in the first vinyl resin containing the unit (A). When the toner mother particles 11 contain the first vinyl resin, the oxazoline group of a part of the units (A) in the first vinyl resin is used as the carboxyl group on the surface of the resin particles 12. To react with. Thereby, the unit (B) can be further contained in the first vinyl resin containing the unit (A).

Preferable examples of the toner of this embodiment include the first aspect and the second aspect shown below.

[Toner of the first aspect]
Hereinafter, the first aspect of the toner will be described with reference to FIG. The toner of the first aspect contains toner particles 20. The toner particles 20 include a toner mother particle 21 and an external additive. The external additive is provided on the surface of the toner matrix particles 21. The external additive contains resin particles 22. The resin particles 22 and the toner mother particles 21 are covalently bonded to each other. The resin particles 22 contain the first vinyl resin. The toner mother particle 21 has a carboxyl group on its surface. The resin particles 22 have a resin core 23 and a coat layer 24. The coat layer 24 covers the surface of the resin core 23. The first vinyl resin is contained in the coat layer 24. The first vinyl resin contained in the coat layer 24 contains a unit (A) and a unit (B). In the first aspect, the unit (B) is a unit represented by the following formula (B1). Hereinafter, the "unit represented by the formula (B1)" may be described as the "unit (B1)". The covalent bond that binds the resin particles 22 and the toner mother particles 21 to each other is a first amide bond. In the first aspect, the first amide bond is an amide bond contained in the unit (B1).

In formula (B1), R ¹ represents the same group as ^{R 1} in formula (A). R ²¹ represents an atom constituting the toner mother particle 21. The oxazoline group of a part of the units (A) in the first vinyl resin contained in the coat layer 24 is reacted with the carboxyl group on the surface of the toner matrix particles 21. Thereby, the unit (B1) can be further contained in the first vinyl resin containing the unit (A). Hereinafter, the "first vinyl resin containing the unit (A) and the unit (B1)" may be referred to as "specific first vinyl resin (A-B1)". Hereinafter, the resin particles 22 and the toner mother particles 21 included in the toner of the first aspect will be further described.

<Resin particles>
The resin particles 22 have a resin core 23 and a coat layer 24. The number average primary particle diameter of the resin particles 22 is preferably 60 nm or more and 120 nm or less, and more preferably 65 nm or more and 105 nm or less. When the number average primary particle diameter of the resin particles 22 is within such a range, the resin particles 22 and the toner mother particles 21 can be suitably bonded, and the resin particles 22 can be detached from the toner mother particles 21. It can be suitably suppressed. The number average primary particle diameter of the resin particles 22 may be 65 nm or more and 70 nm or less, 75 nm or more and 80 nm or less, 90 nm or more and 95 nm or less, 95 nm or more and 100 nm or less, or 100 nm or more and 105 nm or less.

When the number average primary particle diameter of the resin particles 22 is 60 nm or more and 120 nm or less, the following advantages can also be obtained. When the external additive contains external additive particles other than the resin particles 22 (hereinafter, may be referred to as “other external additive particles”), the other external additive particles are embedded in the toner mother particles 21. Can be suppressed. This advantage is particularly easy to obtain when the number average primary particle size of the other external additive particles is smaller than the number average primary particle size of the resin particles 22. When the other external additive particles are silica particles, it is possible to prevent the silica particles from being embedded in the toner mother particles 21. Therefore, the fluidity of the toner is easily ensured. When the other external additive particles are titanium oxide particles, it is possible to prevent the titanium oxide particles from being embedded in the toner mother particles 21. Therefore, it is easier to secure the charge stability of the toner. The other external additive particles will be described later.

(Coat layer)
The coat layer 24 covers the surface of the resin core 23. The coat layer 24 preferably covers the entire surface of the resin core 23, and more preferably completely covers the entire surface of the resin core 23. The coat layer 24 preferably contains a specific first vinyl resin (AB1), and more preferably contains only a specific first vinyl resin (AB1).

The specific first vinyl resin (A-B1) preferably further contains a unit represented by the following formula (C) in addition to the unit (A) and the unit (B1). Hereinafter, the "unit represented by the formula (C)" may be described as the "unit (C)". It is preferable that the resin core 23 has a carboxyl group and the coat layer 24 contains a specific first vinyl resin (AB1) containing a unit (C). The coat layer 24 preferably contains only a specific first vinyl resin (AB1) containing the unit (C). When the specific first vinyl resin (AB1) contained in the coat layer 24 contains the unit (C), the resin core 23 and the coat layer 24 are bonded to each other by a second amide bond. The second amide bond is an amide bond contained in the unit (C). By bonding the resin core 23 and the coat layer 24 to each other, it is possible to prevent the coat layer 24 from peeling off from the resin core 23.

In formula (C), R ¹ represents the same group as ^{R 1} in formula (A). R ³ represents an atom constituting the resin core 23. Of the large number of units (A) in the specific first vinyl resin (A-B1) contained in the coat layer 24, the oxazoline group of a part of the unit (A) is a carboxyl group on the surface of the resin core 23. To react with. Thereby, the unit (C) can be further contained in the specific first vinyl resin (AB1). The resin core 23 is bonded to the toner mother particles 21 via the first amide bond and the second amide bond in the first vinyl resin contained in the coat layer 24.

In the toner of the first aspect, the coat layer 24 contains the unit (A). Unit (A) comprises an unopened ring oxazoline group. The unopened ring oxazoline group has a cyclic structure and exhibits strong positive chargeability. Therefore, the toner provided with the resin particles 22 having such a coat layer 24 is excellent in positive chargeability. The unopened ring-opened oxazoline group in the unit (A) reacts with the carboxyl group to open the ring to form the unit (B1) or the unit (C). The positive chargeability of the ring-opened oxazoline group is lower than that of the unopened oxazoline group.

The specific first vinyl resin (AB1) contained in the coat layer 24 is preferably a polymer of a monomer containing a vinyl compound represented by the following formula (1). Hereinafter, the "vinyl compound represented by the formula (1)" may be referred to as "vinyl compound (1)".

In formula (1), R ¹ represents the same group as ^{R 1} in formula (A). ^{A preferred example of R 1} in formula (1) is the same as a preferred example ^{of R 1} in formula (A). Preferable examples of the vinyl compound (1) include 2-vinyl-2-oxazoline. When the vinyl compound (1) is 2-vinyl-2-oxazoline, R ¹ in the formula (1) is a hydrogen atom.

By polymerizing the monomer containing the vinyl compound (1), the unit (A) can be introduced into a specific first vinyl resin (AB1). The unit (A) corresponds to a repeating unit derived from the vinyl compound (1). The specific first vinyl resin (AB1) is a polymer of a vinyl compound. The vinyl compound contains at least one functional group of a vinyl group (CH ₂ = CH−), a vinylidene group (CH ₂ = C <) and a vinylene group (−CH = CH−) in the molecule. When the carbon double bond (C = C) contained in a functional group such as a vinyl group is cleaved and an addition polymerization reaction occurs, the vinyl compound becomes a polymer (vinyl resin).

The specific first vinyl resin (AB1) may be a polymer of only the vinyl compound (1). Alternatively, the specific first vinyl resin (AB1) may be a polymer of the vinyl compound (1) and a vinyl compound other than the vinyl compound (1). Hereinafter, "vinyl compounds other than the vinyl compound (1)" may be referred to as "other vinyl compounds".

Examples of other vinyl compounds include ethylene, propylene, butadiene, vinyl chloride, (meth) acrylic acid, (meth) acrylic acid ester, acrylonitrile, and styrene. As other vinyl compounds, (meth) acrylic acid ester is preferable, (meth) acrylic acid alkyl ester is more preferable, and methyl (meth) acrylate or butyl (meth) acrylate is further preferable. Only one other vinyl compound may be used, or two or more (eg, two) other vinyl compounds may be used.

When the other vinyl compound is a (meth) acrylic acid alkyl ester, the specific first vinyl resin (A-B1) is represented by the following formula (D) in addition to the unit (A) and the unit (B1). Further includes the units represented. The unit (D) contained in the specific first vinyl resin (AB1) may be only one type of unit (D), and may be two or more types (for example, two types) of unit (D). You may.

In formula (D), R ⁴ represents a hydrogen atom or a methyl group. When the other vinyl compound is an acrylic acid alkyl ester, R ⁴ represents a hydrogen atom. When the other vinyl compound is an alkyl methacrylate ester, R ⁴ represents a methyl group. R ⁵ represents an optionally substituted alkyl group. Examples of the alkyl group represented by R ⁵ include a linear alkyl group, a branched chain alkyl group, and a cyclic alkyl group. The ^{alkyl group represented by R 5} may be substituted with a substituent. Examples of such a substituent include a phenyl group. R ⁵ preferably represents an alkyl group, more preferably represents an alkyl group having 1 or more and 8 or less carbon atoms, and is a methyl group, an ethyl group, a propyl group (for example, an n-propyl group or an isopropyl group), or butyl. It is more preferable to represent a group (for example, an n-butyl group, a tert-butyl group, or an isobutyl group), or a 2-ethylhexyl group, and it is particularly preferable to represent a methyl group or a butyl group.

The specific first vinyl resin (AB1) is preferably a polymer of a monomer containing the vinyl compound (1) and the (meth) acrylic acid alkyl ester, and is preferably a polymer of the vinyl compound (1) and at least two kinds of (meth) acrylic acid alkyl esters. It is more preferable that it is a polymer of a monomer containing a meta) alkyl ester of acrylic acid, and further preferably it is a polymer of only a vinyl compound (1) and at least two kinds of alkyl esters of (meth) acrylic acid. A polymer of compound (1), methyl (meth) acrylate and butyl (meth) acrylate is more preferable, and a polymer of 2-vinyl-2-oxazoline, methyl methacrylate and butyl acrylate. It is even more preferable that the polymer is a polymer of 5 parts by mass of 2-vinyl-2-oxazoline, 4 parts by mass of methyl methacrylate and 1 part by mass of butyl acrylate. The Tg of the specific first vinyl resin (AB1) is preferably 30 ° C. or higher and 70 ° C. or lower, and more preferably 40 ° C. or higher and 60 ° C. or lower.

The thickness of the coat layer 24 is preferably 3.0 nm or less, more preferably 0.1 nm or more and 3.0 nm or less, and further preferably 1.6 nm or more and 1.8 nm or less. Since the specific first vinyl resin (A-B1) contains the unit (B1), the thickness of the coat layer 24 can be 3.0 nm or less. Thereby, the abundance of nitrogen atoms on the surface of the resin particles 22 can be adjusted to an appropriate amount. This makes it difficult for the resin particles 22 to adsorb water. As a result, it is possible to provide a toner having particularly excellent charge stability even when images are continuously formed in a high temperature and high humidity environment. The thickness of the coat layer 24 can be measured by the method described in Examples described later or a method similar thereto. The smaller the acid value of the resin core 23, the thinner the thickness of the coat layer 24 tends to be. For example, when the acid value of the resin core 23 is 5.0 mgKOH / g or less, the thickness of the coat layer 24 tends to be 3.0 nm or less.

The external additive may contain only one type of resin particles 22 as the resin particles 22, or may contain two or more types of resin particles 22. The amount of the resin particles 22 is preferably 0.5 parts by mass or more and 5.0 parts by mass or less with respect to 100.0 parts by mass of the toner mother particles 21. When the external additive contains two or more kinds of resin particles 22, the total amount of the resin particles 22 is 0.5 parts by mass or more and 5.0 parts by mass or less with respect to 100.0 parts by mass of the toner mother particles 21. Is preferable.

(Resin core)
The resin core 23 preferably contains a resin, and more preferably contains only the resin. As the resin contained in the resin core 23, a second vinyl resin is preferable. Examples of the monomer for synthesizing the second vinyl resin include a first vinyl monomer, a second vinyl monomer, and a third vinyl monomer. The first vinyl monomer is a vinyl monomer having one vinyl group and no carboxyl group. The second vinyl monomer is a vinyl monomer having one vinyl group and one carboxyl group. The third vinyl monomer is a vinyl monomer having at least two vinyl groups.

In order to include the unit (C) in the specific first vinyl resin (AB1) and bond the resin core 23 and the coat layer 24 to each other, it is preferable that the resin core 23 has a carboxyl group. In order to form such a resin core 23, it is preferable that the second vinyl resin is a second vinyl resin having a carboxyl group.

The second vinyl resin having a carboxyl group is preferably a polymer of a monomer containing a first vinyl monomer, a second vinyl monomer, and a third vinyl monomer. The second vinyl resin having a carboxyl group is more preferably a polymer of only the first vinyl monomer, the second vinyl monomer, and the third vinyl monomer. The second vinyl resin having a carboxyl group includes a first vinyl monomer of 128 parts by mass or more and 135 parts by mass or less, a second vinyl monomer of 5 parts by mass or more and 6 parts by mass or less, and a second vinyl monomer of 7 parts by mass or more and 13 parts by mass or less. 3 It is more preferable that it is a polymer with a vinyl monomer.

Examples of the first vinyl monomer include styrene, alkylstyrene, hydroxystyrene, styrene halide, vinyl acetate, (meth) acrylonitrile, (meth) acrylic acid alkyl ester, (meth) acrylic acid halogenated alkyl ester, and (meth). ) Acrylic acid hydroxyalkyl ester.

Examples of alkyl styrene include α-methyl styrene, m-methyl styrene, p-methyl styrene, p-ethyl styrene, and 4-tert-butyl styrene. Examples of hydroxystyrene include p-hydroxystyrene and m-hydroxystyrene. Examples of halogenated styrene include α-chlorostyrene, o-chlorostyrene, m-chlorostyrene, and p-chlorostyrene. Examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, iso-propyl (meth) acrylate, and n (meth) acrylate. -Butyl, iso-butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate can be mentioned. Examples of the (meth) acrylic acid halogenated alkyl ester include (meth) acrylic acid halide methyl, (meth) acrylic acid halogenated ethyl, (meth) acrylic acid halogenated n-propyl, and (meth) acrylic acid halogenated. Examples thereof include iso-propyl, n-butyl (meth) acrylate halide, iso-butyl (meth) acrylate halide, and 2-ethylhexyl (meth) acrylate halide. Examples of the (meth) acrylic acid hydroxyalkyl ester include (meth) acrylic acid 2-hydroxyethyl, (meth) acrylic acid 3-hydroxypropyl, (meth) acrylic acid 2-hydroxypropyl, and (meth) acrylic acid 4. -Hydroxybutyl can be mentioned.

As the first vinyl monomer, styrene, (meth) acrylic acid alkyl ester, (meth) acrylonitrile, or (meth) acrylic acid halogenated alkyl ester is preferable. As the (meth) acrylic acid alkyl ester, methyl (meth) acrylate is preferable, and methyl methacrylate is more preferable. As the (meth) acrylonitrile, acrylonitrile is preferable. As the (meth) acrylic acid halide alkyl ester, (meth) acrylic acid halide ethyl is preferable, (meth) acrylic acid trifluoroethyl is more preferable, acrylic acid trifluoroethyl is more preferable, and acrylic acid 2,2, 2-Trifluoroethyl (ie, 2,2,2-trifluoroacrylate) is particularly preferred.

Examples of the second vinyl monomer include (meth) acrylic acid.

Examples of the third vinyl monomer include divinylbenzene, trivinylbenzene, ethylene glycol dimethacrylate, and ethylene glycol diacrylate. As the third vinyl monomer, divinylbenzene or ethylene glycol dimethacrylate is preferable.

The second vinyl resin is preferably a polymer of styrene, acrylic acid and divinylbenzene. The second vinyl resin is also preferably a polymer of methyl methacrylate, methacrylic acid and ethylene glycol dimethacrylate. The second vinyl resin is also preferably a polymer of acrylonitrile, acrylic acid and divinylbenzene. The second vinyl resin is also preferably a polymer of 2,2,2-trifluoroacrylate, methacrylic acid and ethylene glycol dimethacrylate.

The resin contained in the resin core 23 preferably does not contain a nitrogen atom in the molecule. As a result, the amount of nitrogen atoms present in the resin core 23 can be adjusted to an appropriate amount, and the resin core 23 is less likely to adsorb water. This makes it difficult for the toner particles 20 to adsorb water. As a result, the charging stability of the toner when images are continuously formed in a high temperature and high humidity environment can be further improved.

<Toner mother particles>
The toner mother particles 21 may contain, for example, at least one of a binder resin, a colorant, a mold release agent, and a charge control agent. In the first aspect, the toner mother particle 21 has a carboxyl group on its surface. The carboxyl group of the toner mother particles 21 on the surface thereof is preferably the carboxyl group of the binder resin.

(Bundling resin)
The binding resin preferably contains a polyester resin. The binding resin may contain only polyester resin. Alternatively, the binder resin may further contain a thermoplastic resin other than the polyester resin in addition to the polyester resin. Examples of the thermoplastic resin other than the polyester resin include styrene resin, acrylic acid resin, olefin resin, vinyl resin, polyamide resin, and urethane resin. The toner mother particles 21 may contain only one type of binder resin, or may contain two or more types (for example, two types) of binder resin. Hereinafter, the polyester resin will be described.

The polyester resin is obtained by polycondensing an alcohol monomer and a carboxylic acid monomer. The polyester resin is a polymer of an alcohol monomer and a carboxylic acid monomer.

Examples of alcohol monomers include diol monomers, bisphenol monomers, and trihydric or higher alcohol monomers.

Examples of diol monomers include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 2-butene-1,4-diol. , 1,5-Pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, 1,4-benzenediol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.

Examples of bisphenol monomers include bisphenol A, hydrogenated bisphenol A, bisphenol A ethylene oxide adduct, and bisphenol A propylene oxide adduct.

Examples of trihydric or higher alcohol monomers include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol. , 1,2,5-pentantriol, glycerol, diglycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, and 1,3,5-triol Hydroxylmethylbenzene can be mentioned.

Examples of the carboxylic acid monomer include a divalent carboxylic acid monomer and a trivalent or higher carboxylic acid monomer.

Examples of divalent carboxylic acid monomers include maleic acid, fumaric acid, citraconic acid, succinic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, 5-sulfoisophthalic acid, sodium 5-sulfoisophthalate, cyclohexanedicarboxylic acid. , Adipic acid, sebacic acid, azelaic acid, malonic acid, succinic acid, alkylsuccinic acid, and alkenylsuccinic acid. Examples of alkyl succinic acid include n-butyl succinic acid, isobutyl succinic acid, n-octyl succinic acid, n-dodecyl succinic acid, and isododecyl succinic acid. Examples of alkenyl succinic acid include n-butenyl succinic acid, isobutenyl succinic acid, n-octenyl succinic acid, n-dodecenyl succinic acid, and isododecenyl succinic acid.

Examples of trivalent or higher valent carboxylic acid monomers include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2. , 4-Butantricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxy-2-methyl-2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane , 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, and empole trimeric acid.

Only one kind of alcohol monomer may be used, or two or more kinds may be used. Only one kind of carboxylic acid monomer may be used, or two or more kinds may be used. Further, the carboxylic acid monomer may be derivatized into an ester-forming derivative and used. Examples of ester-forming derivatives include acid halides, acid anhydrides, and lower alkyl esters. The lower alkyl is, for example, an alkyl group having 1 or more carbon atoms and 6 or less carbon atoms.

The toner mother particles 21 preferably contain a non-crystalline polyester resin and a crystalline polyester resin as the binder resin. When the toner mother particles 21 contain a crystalline polyester resin, sharp meltability can be imparted to the toner. In order to achieve both heat-resistant storage and low-temperature fixability of the toner, the amount of crystalline polyester resin is 5 with respect to the total amount of polyester resin (total amount of crystalline polyester resin and non-crystalline polyester resin). It is preferably 8% by mass or more and 20% by mass or less, and more preferably 8% by mass or more and 12% by mass or less.

As the non-crystalline polyester resin, a polymer of at least one kind of bisphenol monomer and at least one kind of divalent carboxylic acid monomer is preferable. The non-crystalline polyester resin is more preferably a polymer of a bisphenol A ethylene oxide adduct, a bisphenol A propylene oxide adduct, terephthalic acid, and n-dodecenyl succinic acid.

The crystalline polyester resin is preferably a polymer of at least one diol monomer and at least one divalent carboxylic acid monomer. The crystalline polyester resin is more preferably a polymer of 1,4-butanediol, 1,6-hexanediol, 1,4-benzenediol, and fumaric acid.

In order for the toner core to have an appropriate sharp melt property, it is preferable to contain a crystalline polyester resin having a crystallinity index of 0.90 or more and 1.20 or less in the toner core. The crystallinity index of the polyester resin corresponds to the ratio of Tm of the polyester resin to Mp of the polyester resin (Tm / Mp). The crystallinity index of the crystalline polyester resin can be adjusted by changing the type or amount (blending ratio) of the material for synthesizing the crystalline polyester resin. For amorphous resins, it is often not possible to measure a clear Mp.

The Tg of the polyester resin is preferably 30 ° C. or higher and 80 ° C. or lower, and more preferably 55 ° C. or higher and 60 ° C. or lower. When the toner mother particles 21 contain an amorphous polyester resin, the Tg of the amorphous polyester resin is preferably 30 ° C. or higher and 80 ° C. or lower, and more preferably 55 ° C. or higher and 60 ° C. or lower.

The Mp of the polyester resin is preferably 50 ° C. or higher and 100 ° C. or lower, and more preferably 80 ° C. or higher and 85 ° C. or lower. When the toner mother particles 21 contain a crystalline polyester resin, the Mp of the crystalline polyester resin is preferably 50 ° C. or higher and 100 ° C. or lower, and more preferably 80 ° C. or higher and 85 ° C. or lower.

The Tm of the polyester resin is preferably 60 ° C. or higher and 130 ° C. or lower. When the toner mother particles 21 contain an amorphous polyester resin and a crystalline polyester resin, the Tm of the amorphous polyester resin is preferably 100 ° C. or higher and 130 ° C. or lower, and 125 ° C. or higher and 130 ° C. or lower. More preferred. In this case, the Tm of the crystalline polyester resin is preferably 60 ° C. or higher and 95 ° C. or lower, and more preferably 85 ° C. or higher and 90 ° C. or lower.

The Mw of the polyester resin is preferably 10,000 or more and 150,000 or less, and more preferably 25,000 or more and 110,000 or less. When the toner mother particles 21 contain an amorphous polyester resin and a crystalline polyester resin, the Mw of the amorphous polyester resin is preferably 70,000 or more and 150,000 or less, and is preferably 100,000 or more and 105,000 or less. Is more preferable. In this case, the Mw of the crystalline polyester resin is preferably 10,000 or more and 50,000 or less, and more preferably 25,000 or more and 30,000 or less.

The Mn of the polyester resin is preferably 2000 or more and 5000 or less, and more preferably 3500 or more and 4500 or less. When the toner mother particles 21 contain an amorphous polyester resin and a crystalline polyester resin, the Mn of the amorphous polyester resin is preferably more than 4000 and 5000 or less, and more preferably 4500 or more and 5000 or less. In this case, the Mn of the crystalline polyester resin is preferably 2000 or more and 4000 or less, and more preferably 3500 or more and 4000 or less.

The acid value of the polyester resin is preferably 1 mgKOH / g or more and 30 mgKOH / g or less, and more preferably 1 mgKOH / g or more and 15 mgKOH / g or less. When the toner mother particles 21 contain an amorphous polyester resin and a crystalline polyester resin, the acid value of the amorphous polyester resin is preferably 6 mgKOH / g or more and 30 mgKOH / g or less, and 10 mgKOH / g or more and 15 mgKOH / g. It is more preferably g or less. In this case, the acid value of the crystalline polyester resin is preferably 1 mgKOH / g or more and 5 mgKOH / g or less.

The hydroxyl value of the polyester resin is preferably 10 mgKOH / g or more and 50 mgKOH / g or less, and more preferably 15 mgKOH / g or more and 35 mgKOH / g or less. When the toner mother particles 21 contain an amorphous polyester resin and a crystalline polyester resin, the hydroxyl value of the amorphous polyester resin is preferably 25 mgKOH / g or more and 35 mgKOH / g or less, and 30 mgKOH / g or more and 35 mgKOH / g. It is more preferably g or less. In this case, the hydroxyl value of the crystalline polyester resin is preferably 15 mgKOH / g or more and less than 25 mgKOH / g.

(Colorant)
As the colorant, a pigment or dye known according to the color of the toner can be used. In order to form a high-quality image using toner, the amount of the colorant is preferably 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the binder resin. The toner mother particles 21 may contain only one kind of colorant, or may contain two or more kinds of colorants.

The toner mother particles 21 may contain a black colorant. An example of a black colorant is carbon black. Further, the black colorant may be a colorant that has been adjusted to black by using a yellow colorant, a magenta colorant, and a cyan colorant.

The toner mother particles 21 may contain a color colorant such as a yellow colorant, a magenta colorant, or a cyan colorant.

As the yellow colorant, for example, one or more compounds selected from the group consisting of condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and arylamide compounds can be used. Examples of the yellow colorant include C.I. I. Pigment Yellow (3, 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155 168, 174, 175, 176, 180, 181, 191 and 194), Naphthol Yellow S, Hansa Yellow G, and C.I. I. Bat yellow can be mentioned.

The magenta colorant is selected from the group consisting of, for example, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. One or more compounds can be used. Examples of the magenta colorant include C.I. I. Pigment Red (2, 3, 5, 6, 7, 19, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 144, 146, 150, 166, 169, 177 , 184, 185, 202, 206, 220, 221 and 254).

As the cyan colorant, for example, one or more compounds selected from the group consisting of copper phthalocyanine compounds, anthraquinone compounds, and base dye lake compounds can be used. Examples of the cyan colorant include C.I. I. Pigment Blue (1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, or 66), Phthalocyanine Blue, C.I. I. Bat Blue, and C.I. I. Acid blue can be mentioned.

(Release agent)
The release agent is used, for example, for the purpose of improving the fixability or high temperature offset resistance of the toner. In order to enhance the cationic property of the toner matrix particles 21, it is preferable to prepare the toner matrix particles 21 using a wax having a cationic property.

The release agent is, for example, an aliphatic hydrocarbon wax, a vegetable wax, an animal wax, a mineral wax, a wax containing a fatty acid ester as a main component, or a wax obtained by deoxidizing a part or all of the fatty acid ester. Is preferable. Examples of the aliphatic hydrocarbon wax include ester wax, low molecular weight polyethylene, low molecular weight polypropylene, polyolefin copolymer, polyolefin wax, microcrystalline wax, paraffin wax, and Fishertropch wax. Aliphatic hydrocarbon waxes also include these oxides. Examples of vegetable waxes include candelilla wax, carnauba wax, wood wax, jojoba wax, and rice wax. Animal waxes include, for example, beeswax, lanolin, and whale wax. Mineral waxes include, for example, ozokerite, ceresin, and petrolatum. Examples of waxes containing fatty acid ester as a main component include montanic acid ester wax and caster wax. The toner mother particles 21 may contain only one type of release agent, or may contain two or more types of release agents.

(Charge control agent)
The charge control agent is used, for example, for the purpose of improving the charge stability or charge rise characteristics of the toner. The charge rising characteristic of the toner is an index of whether or not the toner can be charged to a predetermined charge level in a short time. By incorporating a positively charged charge control agent into the toner mother particles 21, the cationic properties of the toner mother particles 21 can be strengthened. As the positively charged charge control agent, a quaternary ammonium salt is preferable. The toner mother particles 21 may contain only one kind of charge control agent, or may contain two or more kinds of charge control agents.

<Other external additive particles>
The external additive may further contain other external additive particles in addition to the resin particles 22. The other external additive particles are preferably silica particles or metal oxide particles. The metal oxide is preferably, for example, alumina, titanium oxide, magnesium oxide, zinc oxide, strontium titanate, or barium titanate. The external additive may contain one type of other external additive particles, or may contain two or more types of other external agent particles.

The amount of the other external additive particles is preferably 0.5 parts by mass or more and 10.0 parts by mass or less with respect to 100.0 parts by mass of the toner mother particles 21. When the external additive contains two or more kinds of other external additive particles, the total amount of the other external additive particles is 0.5 parts by mass or more and 10 parts by mass or more with respect to the toner mother particles 21 of 100.0 parts by mass. It is preferably 0.0 parts by mass or less. The number average primary particle size of the other external additive particles is preferably 0.5 times or less the number average primary particle size of the resin particles 22. The number of other external additive particles The average primary particle size is preferably 5 nm or more and 30 nm or less. The first aspect of the toner has been described above with reference to FIG.

[Toner of the second aspect]
Hereinafter, the second aspect of the toner will be described with reference to FIG. The toner of the second aspect contains toner particles 30. The toner particles 30 include a toner mother particle 31 and an external additive. The external additive is provided on the surface of the toner matrix particles 31. The external additive contains resin particles 32. The resin particles 32 and the toner mother particles 31 are covalently bonded to each other. The toner mother particles 31 contain the first vinyl resin, and the resin particles 32 have a carboxyl group on the surface thereof. The toner mother particle 31 has a toner core 33 and a shell layer 34. The shell layer 34 covers the surface of the toner core 33. The first vinyl resin is contained in the shell layer 34. The first vinyl resin contained in the shell layer 34 contains a unit (A) and a unit (B). In the second aspect, the unit (B) is a unit represented by the following formula (B2). Hereinafter, the "unit represented by the formula (B2)" may be described as the "unit (B2)". Further, the "first vinyl resin containing the unit (A) and the unit (B2)" may be described as "a specific first vinyl resin (A-B2)". The covalent bond that binds the resin particles 32 and the toner mother particles 31 to each other is the first amide bond. In the second aspect, the first amide bond is an amide bond contained in the unit (B2).

In formula (B2), R ¹ represents the same group as ^{R 1} in formula (A). R ²² represents an atom constituting the resin particle 32. The oxazoline group of a part of the units (A) in the first vinyl resin contained in the shell layer 34 is reacted with the carboxyl group on the surface of the resin particles 32. Thereby, the unit (B2) can be further contained in the first vinyl resin containing the unit (A). Hereinafter, the resin particles 32 and the toner mother particles 31 included in the toner of the second aspect will be described.

<Resin particles>
The resin particles 32 included in the toner of the second aspect correspond to the resin core 23 included in the toner of the first aspect. A preferred example of the resin particles 32 included in the toner of the second aspect is the same as a preferred example of the resin core 23 described in the toner of the first aspect. The resin particles 32 preferably do not have a coat layer. However, the resin particles 32 may include a coat layer (not shown in FIG. 3) made of a material other than the first vinyl resin. The number average primary particle diameter of the resin particles 32 is preferably 60 nm or more and 120 nm or less, more preferably 65 nm or more and 105 nm or less, and further preferably 95 nm or more and 100 nm or less.

<Toner mother particles>
The toner mother particle 31 has a toner core 33 and a shell layer 34. The shell layer 34 covers the surface of the toner core 33. The shell layer 34 preferably covers the entire surface of the toner core 33, and more preferably completely covers the entire surface of the toner core 33.

The toner core 33 in the second aspect corresponds to the toner mother particles 21 in the first aspect. A preferred example of the toner core 33 included in the toner of the second aspect is the same as a preferred example of the toner mother particles 21 included in the toner of the first aspect. The toner core 33 contains, for example, a binder resin. The toner core 33 may further contain at least one of a colorant, a mold release agent, and a charge control agent in addition to the binder resin. A preferred example of the material contained in the toner core 33 in the second aspect (eg, binder resin, colorant, mold release agent, and charge control agent) is the material contained in the toner mother particles 21 in the first aspect (eg, eg. It is the same as a preferable example of a binder resin, a colorant, a mold release agent, and a charge control agent). Next, the shell layer 34 included in the toner of the second aspect will be described.

(Shell layer)
The shell layer 34 preferably contains a resin, and more preferably contains only the resin. Hereinafter, the "resin contained in the shell layer 34" may be referred to as "shell resin". It is preferable that the shell layer 34 is substantially made of a shell resin. In the second aspect, the shell resin is a specific first vinyl resin (AB2).

In the toner of the second aspect, the shell layer 34 includes the unit (A). Unit (A) comprises an unopened ring oxazoline group. As already mentioned, the unopened ring oxazoline group has a cyclic structure and exhibits strong positive chargeability. Therefore, the toner provided with such a shell layer 34 is excellent in positive chargeability. The unopened ring-opened oxazoline group in the unit (A) reacts with the carboxyl group of the resin particle 32 to open the ring to form the unit (B2). The positive chargeability of the ring-opened oxazoline group is lower than that of the unopened oxazoline group.

The specific first vinyl resin (AB2) contained in the shell layer 34 is preferably a polymer of a monomer containing the vinyl compound (1). By polymerizing the monomer containing the vinyl compound (1), the unit (A) can be introduced into a specific first vinyl resin (A-B2). The unit (A) corresponds to a repeating unit derived from the vinyl compound (1). The specific first vinyl resin (AB2) may be a polymer of only the vinyl compound (1). Alternatively, the specific first vinyl resin (AB2) may be a polymer of the vinyl compound (1) and another vinyl compound. When the other vinyl compound is a (meth) acrylic acid alkyl ester, the particular first vinyl resin (A-B2) adds a unit (D) in addition to the unit (A) and the unit (B2). include.

The specific first vinyl resin (A-B2) contained in the shell layer 34 is preferably a polymer of a monomer containing the vinyl compound (1) and the (meth) acrylic acid alkyl ester, and the vinyl compound (1). It is more preferable that it is a polymer of a monomer containing at least two kinds of (meth) acrylic acid alkyl esters, and it is a polymer of only vinyl compound (1) and at least two kinds of (meth) acrylic acid alkyl esters. More preferably, it is a polymer of the vinyl compound (1), methyl (meth) acrylate and butyl (meth) acrylate, and 2-vinyl-2-oxazoline, methyl methacrylate and butyl acrylate are more preferable. It is even more preferable that the polymer is a polymer of 5 parts by mass of 2-vinyl-2-oxazoline, 4 parts by mass of methyl methacrylate, and 1 part by mass of butyl acrylate.

The Tg of the specific first vinyl resin (AB2) is preferably 30 ° C. or higher and 70 ° C. or lower, and more preferably 40 ° C. or higher and 60 ° C. or lower. A preferred example of the specific first vinyl resin (A-B2) is the specific first vinyl resin (A-B2) except that the unit (B1) and the unit (B2) are included instead of the unit (C). It is the same as the preferable example of B1).

The thickness of the shell layer 34 is preferably 20.0 nm or less, more preferably 10.0 nm or less, and even more preferably 3.0 nm or less. The lower limit of the thickness of the shell layer 34 is not particularly limited, but can be, for example, 0.1 nm or more. Since the resin particles 32 and the shell layer 34 are chemically bonded, the strength of the shell layer 34 can be improved and the thickness of the shell layer 34 can be reduced. The thickness of the shell layer 34 can be measured by the method described in Examples described later or a method similar thereto.

<Other external additive particles>
The toner particles 30 of the toner of the second aspect may include other external additive particles. The examples of the other external additive particles in the toner of the second aspect are the same as the examples of the other external additive particles in the toner of the first aspect. The second aspect of the toner has been described above with reference to FIG.

The toner of the present embodiment is an electrostatic latent image developing toner that can be suitably used for developing an electrostatic latent image. The toner of the present embodiment may form a one-component developer, or may form a two-component developer together with a carrier. When the toner constitutes a one-component developer, the toner is positively charged by rubbing against the developing sleeve or the toner charging member in the developing apparatus. The toner charging member is, for example, a doctor blade. When the toner constitutes a two-component developer, the toner is positively charged by rubbing against the carrier in the developing apparatus. In order to preferably form an image, the D _{50 of the} toner matrix particles is preferably 5 μm or more and 9 μm or less.

The toner of the present embodiment can be used for forming an image in, for example, an electrophotographic apparatus (image forming apparatus). Hereinafter, an example of an image forming method using an electrophotographic apparatus will be described. First, an electrostatic latent image is formed on the photosensitive layer of the photoconductor drum based on the image data. Next, the formed electrostatic latent image is developed using toner (development step). In the developing process, the developing apparatus supplies the toner on the developing sleeve to the photosensitive layer of the photoconductor drum and attaches it to the electrostatic latent image by electrostatic force. In this way, the electrostatic latent image is developed, and a toner image is formed on the photosensitive layer of the photoconductor drum. Subsequently, the toner image is transferred to a recording medium (for example, paper), and then the unfixed toner image is fixed to the recording medium by heating. As a result, an image is formed on the recording medium.

[Toner manufacturing method]
The method for producing toner of the present embodiment includes at least an external addition step and a bonding step. The method for producing toner of the present embodiment may further include a resin particle forming step and a toner mother particle forming step. First, with reference to FIG. 1 again, an outline of the external addition step and the joining step will be described.

<External process>
In the external addition step, an external additive containing the resin particles 12 is attached to the surface of the toner mother particles 11. Specifically, a mixer (for example, an FM mixer manufactured by Nippon Coke Industries Co., Ltd.) is used to mix the toner mother particles 11 and the external additive containing the resin particles 12. As a result, the external additive containing the resin particles 12 adheres to the surface of the toner mother particles 11. After the external addition step, the external additive containing the resin particles 12 adheres to the surface of the toner matrix particles 11 by physical force regardless of chemical bonding.

The amount of unopened ring oxazoline groups contained in 1 g of the resin particles 12 after the external addition step and before the bonding step shall be 0.002 mmol / g or more and 5.000 mmol / g or less as measured by gas chromatography-mass spectrometry. Is preferable. As already mentioned, the unopened ring oxazoline group exhibits strong positive chargeability. However, the unopened ring oxazoline group has water absorption. From these facts, by controlling the ring-opening ratio of the oxazoline group in the resin particles 22, it is possible to further improve the charge stability of the toner when images are continuously formed in a high temperature and high humidity environment. The amount of the unopened ring oxazoline group contained in 1 g of the resin particles 12 is more preferably 0.002 mmol / g or more and 3.000 mmol / g or less, and 0.002 mmol / g or more and 0.060 mmol / g or less. Is more preferable. The amount of unopened ring oxazoline groups contained in 1 g of the resin particles 12 is 0.002 mmol / g or more and 0.005 mmol / g or less, 0.031 mmol / g or more and less than 0.032 mmol / g, 0.032 mmol / g or more and 0. It may be less than 040 mmol / g, 0.040 mmol / g or more and 0.045 mmol / g or less, 0.050 mmol / g or more and less than 0.055 mmol / g, or 0.055 mmol / g or more and 0.060 mmol / g or less. The amount of the unopened ring oxazoline group contained in 1 g of the resin particles 12 can be determined by the method described in Examples described later or a method similar thereto.

<Joining process>
In the bonding step, the resin particles 12 and the toner mother particles 11 are covalently bonded to each other to form the toner particles 10. Preferable examples of the bonding step are as follows. One of the toner mother particles 11 and the resin particles 12 contains a first vinyl resin. The other of the toner mother particles 11 and the resin particles 12 has a carboxyl group on the surface. The first vinyl resin contains the unit (A). In the bonding step, the unit (A) of the first vinyl resin and the carboxyl group are reacted in the presence of an acid catalyst. As a result, the unit (B) is formed, and the resin particles 12 and the toner mother particles 11 are covalently bonded to each other. The covalent bond is the first amide bond. The first amide bond is an amide bond contained in the formed unit (B). After the bonding step, the resin particles 12 contained in the external additive are bonded to the surface of the toner mother particles 11 by chemical bonding.

As the acid catalyst, hydrogen halide is preferable, and hydrogen chloride is more preferable. It is preferable that the unit (A) of the first vinyl resin reacts with the carboxyl group in the presence of a gaseous acid catalyst. By using the gaseous acid catalyst, the reaction can proceed without separating the powder toner mother particles 11 and the powder resin particles 12 adhering by physical force. It is preferable not to use a solvent or a dispersion medium in the bonding step.

The toner mother particles 11 to which the external additive containing the resin particles 12 is attached are placed in the reaction vessel. Reduce the internal pressure of the reaction vessel to the specified pressure. An acid catalyst (preferably a gaseous acid catalyst) is placed in the reaction vessel. While stirring the toner mother particles 11 to which the external additive containing the resin particles 12 is attached, the internal pressure of the reaction vessel is set to a predetermined pressure and the temperature inside the reaction vessel is set to the first predetermined temperature in the presence of an acid catalyst for the first predetermined time. Keep in. The predetermined pressure is preferably larger than 0.0 Pa and 0.5 Pa or less. The first predetermined temperature is preferably 0 ° C. or higher and 50 ° C. or lower. The first predetermined time is preferably 0.5 minutes or more and 30 minutes or less, and more preferably 3 minutes or more and 7 minutes or less. While the first predetermined time is maintained, the resin particles 12 and the toner mother particles 11 are covalently bonded to each other. Specifically, the oxazoline group of the unit (A) contained in the first vinyl resin contained in one of the toner mother particles 11 and the resin particles 12 and the carboxyl group of the other of the toner mother particles 11 and the resin particles 12 on the surface thereof. , Reaction (specifically, dehydration reaction) to form the first amide bond. The outline of the external addition process and the bonding process has been described above with reference to FIG.

Hereinafter, the method for producing the toner of the first aspect will be described with reference to FIG. 2 again.

<Toner of the first aspect: Resin particle forming step>
The resin particle forming step includes, for example, a forming step of the resin core 23, a step of preparing a coating liquid, and a step of forming a coating layer 24. In addition to FIG. 2, a preferred method for forming the resin particles 22 will be described with reference to FIG. FIG. 4 schematically shows an example of the reaction between the resin core 23 and the material for forming the coat layer 24 (hereinafter, may be referred to as the coat layer material) 124 in the first aspect. In FIG. 4 and FIGS. 5 to 7 described later, the carbon atom and the hydrogen atom bonded to the carbon atom are omitted to describe the chemical formula. Further, in FIGS. 4 to 7, the ^{case where R 1} in the formula (A) represents a hydrogen atom is shown as an example.

(Resin core forming process)
In the process of forming the resin core 23, a dispersion liquid containing the resin core 23 (dispersion liquid of the resin core 23) is prepared. The resin core 23 has a carboxyl group on its surface. First, the monomer used for synthesizing the resin contained in the resin core 23 is polymerized (preferably emulsion polymerization) in an aqueous medium. The monomer may be polymerized in the presence of a polymerization initiator. Potassium persulfate is preferable as the polymerization initiator. The longer the polymerization time of the monomer, the larger the number average primary particle size of the resin core 23 tends to be.

The aqueous medium is preferably water or a dispersion medium containing water as a main component. When the aqueous medium is composed of water, the water is preferably ion-exchanged water or pure water. The aqueous medium containing water as a main component is preferably a mixed solution of a dispersion stabilizer and water. As the dispersion stabilizer, a surfactant or an emulsifier is preferable, and polyoxyethylene sorbitan monolaurate is more preferable.

Next, the resin core 23 is taken out from the dispersion liquid of the resin core 23. It is preferable not to dry the removed resin core 23.

(Preparation process of coating liquid)
In the coating liquid preparation step, a solution containing the coating layer material 124 is prepared. The coat layer material 124 comprises a unit (A). As the solution of the coat layer material 124, for example, "Epocross (registered trademark) WS-300" or "Epocross WS-700" manufactured by Nippon Shokubai Co., Ltd. can be used. Epocross WS-300 contains a polymer (water-soluble cross-linking agent) of 2-vinyl-2-oxazoline and methyl methacrylate. The mass ratio of the monomers constituting the polymer is (2-vinyl-2-oxazoline) :( methyl methacrylate) = 9: 1. Epocross WS-700 contains a polymer (water-soluble cross-linking agent) of 2-vinyl-2-oxazoline, methyl methacrylate and butyl acrylate. The mass ratio of the monomers constituting the polymer is (2-vinyl-2-oxazoline) :( methyl methacrylate) :( butyl acrylate) = 5: 4: 1.

(Coat layer forming process)
In the step of forming the coat layer 24, the coat layer 24 is formed. More specifically, the resin core 23 (preferably the resin core 23 in a non-dried state) and the solution (coating liquid) of the coating layer material 124 are mixed at a second predetermined temperature. Here, at the second predetermined temperature, the carboxyl group (carboxyl group existing on the surface of the resin core 23) and the oxazoline group (oxazoline group contained in the coat layer material 124) react to form the second amide bond Y2. It is above the temperature. As a result, the coat layer 24 is formed and the resin particles 22 are obtained. In each of the obtained resin particles 22, the surface of the resin core 23 is covered with the coat layer 24.

Specifically, first, the resin core 23 and the solution of the coat layer material 124 are mixed to obtain a dispersion liquid. Here, the coat layer material 124 adheres to the surface of the resin core 23 in the dispersion liquid. In order to uniformly adhere the coat layer material 124 to the surface of the resin core 23, it is preferable to highly disperse the resin core 23 in the dispersion liquid. In order to highly disperse the resin core 23 in the dispersion liquid, the dispersion liquid may contain a dispersion stabilizer, or may be dispersed using a powerful stirrer (for example, "Hibis Dispermix" manufactured by Primix Corporation). The liquid may be agitated.

Next, while stirring the dispersion liquid, the temperature of the dispersion liquid is raised to the second predetermined temperature at the second predetermined temperature rising rate. Then, while stirring the dispersion liquid, the temperature of the dispersion liquid is kept at the second predetermined temperature for a second predetermined time. While the temperature of the dispersion is maintained at the second predetermined temperature, the following reaction proceeds. Specifically, of the large number of oxazoline groups contained in the coat layer material 124, some oxazoline groups react with the carboxyl groups of the resin core 23 to open the ring. As a result, the second amide bond Y2 is formed. That is, the unit (C) is formed. On the other hand, of the large number of oxazoline groups contained in the coat layer material 124, the oxazoline group that does not react with the carboxyl group remains in the coat layer 24 as a unit (A) without ring-opening. The presence of the second amide bond Y2 can be confirmed by the method described in Examples described later or a method similar thereto.

The second predetermined temperature is preferably 50 ° C. or higher and 100 ° C. or lower. When the second predetermined temperature is 50 ° C. or higher, the reaction between the carboxyl group and the oxazoline group easily proceeds. When the second predetermined temperature is 100 ° C. or lower, it is possible to prevent the resin component from melting due to the formation of the coat layer 24. The resin component includes the resin contained in the resin core 23 and the coat layer material 124.

The second predetermined heating rate is preferably, for example, 0.1 ° C./min or more and 3 ° C./min or less. The second predetermined time is preferably, for example, 30 minutes or more and 5 hours or less. It is preferable to stir the dispersion under the condition that the rotation speed is 50 rpm or more and 500 rpm or less. As a result, the reaction between the carboxyl group and the oxazoline group can easily proceed.

<Toner of the first aspect: Toner mother particle forming step>
In the toner mother particle forming step, it is preferable to prepare the toner mother particles 21 by a known pulverization method or a known aggregation method.

An example of the crushing method will be described. First, the binder resin and components other than the binder resin (for example, at least one of a colorant, a charge control agent, a mold release agent, and a magnetic powder) are mixed to obtain a mixture. The mixture is kneaded while melting using a melt-kneading device (for example, a single-screw or twin-screw extruder) to obtain a kneaded product. The kneaded product is crushed and classified. As a result, the toner mother particles 21 having a desired particle size can be obtained.

An example of the agglutination method will be described. First, the particles of the binder resin and the particles of components other than the binder resin (for example, at least one of a colorant particle, a charge control agent particle, a mold release agent particle, and a magnetic powder particle) are included. These particles are agglomerated in an aqueous medium. As a result, agglomerated particles are formed. The agglomerated particles are heated to coalesce the components contained in the agglomerated particles. As a result, the toner mother particles 21 having a desired particle size can be obtained.

<Toner of the first aspect: external addition process>
In the external addition step, an external additive containing the resin particles 22 is attached to the surface of the toner mother particles 21.

<Toner of the first aspect: bonding step>
In the bonding step, the resin particles 22 and the toner mother particles 21 are covalently bonded to each other to form the toner particles 20. Hereinafter, a method of covalently bonding the resin particles 22 and the toner mother particles 21 to each other will be described with reference to FIG. FIG. 5 schematically shows an example of the reaction between the resin particles 22 and the toner mother particles 21 in the first aspect.

The coat layer 24 of the resin particles 22 contains a first vinyl resin. The toner mother particle 21 has a carboxyl group on its surface. The first vinyl resin contains the unit (A). The first vinyl resin preferably further contains the unit (C). In the bonding step, the unit (A) of the first vinyl resin and the carboxyl group on the surface of the toner mother particles 21 are reacted in the presence of an acid catalyst. As a result, the unit (B1) is formed, and a covalent bond is formed between the resin particles 22 and the toner mother particles 21. The covalent bond is the first amide bond Y1. The first amide bond Y1 is an amide bond contained in the formed unit (B1). As a result, the resin particles 22 and the toner mother particles 21 are covalently bonded to each other (specifically, the first amide bond Y1) to form the toner particles 20.

Specifically, while stirring the toner mother particles 21 to which the external additive containing the resin particles 22 is attached, the internal pressure of the reaction vessel is set to a predetermined pressure and the temperature inside the reaction vessel is set to a predetermined pressure in the presence of an acid catalyst for the first predetermined time. 1 Keep at a predetermined temperature. While maintaining the first predetermined temperature, the following reaction proceeds. Of the large number of oxazoline groups contained in the first vinyl resin contained in the coat layer 24 of the resin particles 22, some of the oxazoline groups react with the carboxyl groups on the surface of the toner mother particles 21 to open the ring. As a result, the first amide bond Y1 is formed. That is, the unit (B1) is formed. On the other hand, of the large number of oxazoline groups contained in the first vinyl resin contained in the coat layer 24, the oxazoline group that does not react with the carboxyl group remains in the coat layer 24 as the unit (A) without opening the ring. The presence of the first amide bond Y1 can be confirmed by the method described in Examples described later or a method similar thereto. The method for producing the toner of the first aspect has been described above with reference to FIGS. 2, 4, and 5.

[Method for producing toner of the second aspect]
Hereinafter, the method for producing the toner of the second aspect will be described with reference to FIG. 3 again.

<Toner of the second aspect: resin particle forming step>
The step of forming the resin particles 32 in the second aspect can be performed in the same manner as the step of forming the resin core 23 in the first aspect. The resin particles 32 in the second aspect correspond to the resin core 23 in the first aspect.

<Toner of the second aspect: Toner mother particle forming step>
In the second aspect, the step of forming the toner mother particles 31 includes, for example, a step of forming a toner core and a step of forming a shell layer.

(Toner core forming process)
The toner core forming step in the second aspect can be performed in the same manner as the toner mother particle forming step in the first aspect. The toner core 33 in the second aspect corresponds to the toner mother particles 21 in the first aspect.

(Shell layer forming process)
In the shell layer forming step, the shell layer 34 is formed on the surface of the toner core 33 to obtain the toner matrix particles 31. Examples of the method for forming the shell layer 34 include an in-situ polymerization method, an in-liquid curing coating method, and a core selvation method. For example, the toner core 33 is placed in an aqueous medium in which a material for forming the shell 34 layer (hereinafter sometimes referred to as “shell material”) 134 (see FIG. 6) is dissolved. The shell material 134 is, for example, water soluble. Subsequently, the aqueous medium is heated to allow the polymerization reaction of the shell material 134 to proceed. As a result, the shell layer 34 is formed on the surface of the toner core 33.

In the shell layer forming step, a covalent bond may be formed between the toner core 33 and the shell layer 34. Hereinafter, a method of forming a covalent bond between the toner core 33 and the shell layer 34 will be described with reference to FIG. FIG. 6 schematically shows an example of the reaction between the toner core 33 and the shell material 134 in the second aspect.

Shell material 134 includes unit (A). The toner core 33 has a carboxyl group on its surface. While heating the aqueous medium containing the shell material 134 and the toner core 33, the following reactions proceed. Specifically, of the large number of oxazoline groups contained in the shell material 134, some oxazoline groups react with the carboxyl groups on the surface of the toner core 33 to open the ring. As a result, the third amide bond Y3 is formed. The third amide bond Y3 is an amide bond contained in the unit represented by the following formula (E). On the other hand, of the large number of oxazoline groups contained in the shell material 134, the oxazoline group that does not react with the carboxyl group remains in the shell layer 34 as a unit (A) without ring-opening.

In formula (E), R ¹ represents the same group as ^{R 1} in formula (A). R ⁶ represents an atom constituting the toner core 33. When the third amide bond is formed, the toner core 33 is bonded to the resin particles 32 via the first amide bond and the third amide bond in the first vinyl resin contained in the shell layer 34. As the aqueous medium containing the shell material 134, for example, "Epocross WS-300" or "Epocross WS-700" manufactured by Nippon Shokubai Co., Ltd. can be used.

In forming the shell layer 34, resin particles for forming the shell layer 34 (hereinafter referred to as shell resin particles) may be used as the shell material 134. More specifically, the shell resin particles are attached to the surface of the toner core 33 in a liquid (for example, an aqueous medium) containing the shell resin particles and the toner core 33. Subsequently, by heating the liquid, the film formation of the resin particles for the shell is promoted, and the shell layer 34 is formed on the surface of the toner core 33. While the liquid is kept at a high temperature, the bonding between the shell resin particles (and thus the cross-linking reaction between the shell resin particles) can proceed on the surface of the toner core 33.

<Toner of the second aspect: external addition process>
In the external addition step, an external additive containing the resin particles 32 is attached to the surface of the toner mother particles 31.

<Toner of the second aspect: bonding step>
In the bonding step, the resin particles 32 and the toner mother particles 31 are covalently bonded to each other to form the toner particles 30. Hereinafter, a method of forming a covalent bond between the resin particles 32 and the toner mother particles 31 will be described with reference to FIG. 7. FIG. 7 schematically shows an example of the reaction between the resin particles 32 and the toner mother particles 31 in the second aspect.

The shell layer 34 of the toner mother particles 31 contains a first vinyl resin. The resin particles 32 have a carboxyl group on the surface. The first vinyl resin contains the unit (A). The first vinyl resin preferably further contains the unit (E). In the bonding step, the unit (A) of the first vinyl resin and the carboxyl group are reacted in the presence of an acid catalyst. As a result, the unit (B2) is formed, and a covalent bond is formed between the resin particles 32 and the toner mother particles 31. The covalent bond is the first amide bond Y1. The first amide bond Y1 is an amide bond contained in the formed unit (B2). As a result, the resin particles 32 and the toner mother particles 31 are bonded to each other by a covalent bond (first amide bond Y1).

Specifically, while stirring the toner mother particles 31 to which the external additive containing the resin particles 32 is attached, the internal pressure of the reaction vessel is set to a predetermined pressure and the temperature inside the reaction vessel is set to a predetermined pressure in the presence of an acid catalyst for the first predetermined time. 1 Keep at a predetermined temperature. While maintaining the first predetermined temperature, the following reaction proceeds. Of the large number of oxazoline groups contained in the first vinyl resin contained in the shell layer 34 of the toner mother particles 31, some oxazoline groups react with the carboxyl groups on the surface of the resin particles 32 to open the ring. As a result, the first amide bond Y1 is formed. That is, the unit (B2) is formed. On the other hand, of the large number of oxazoline groups contained in the first vinyl resin contained in the shell layer 34, the oxazoline group that does not react with the carboxyl group remains in the shell layer 34 as a unit (A) without ring-opening. The presence of the first amide bond Y1 can be confirmed by the method described in Examples described later or a method similar thereto. As described above, the method for producing the toner of the second aspect has been described with reference to FIGS. 3, 6, and 7.

The present invention will be further described with reference to examples. The present invention is not limited to the scope of the examples. Hereinafter, the manufacturing method, the measuring method, the evaluation method, and the evaluation result of the toners TA-1 to TA-5 and TB-1 will be described. In the evaluation in which an error occurs, a considerable number of measured values in which the error is sufficiently small are obtained, and the average number of the obtained measured values is used as the evaluation value.

[Toner manufacturing method]
<Formation process of resin particles>
Resin particles P-1 to P-5 for use in producing toners TA-1 to TA-5 and TB-1 were produced by the following methods. The composition of each of the resin particles P-1 to P-5 is shown in Table 1.

“WS-700” in Table 1 indicates “Epocross WS-700” manufactured by Nippon Shokubai Co., Ltd. “Tween 20” in Table 1 indicates “Tween 20” manufactured by Tokyo Chemical Industry Co., Ltd. In Table 1, "amount" indicates the amount added (unit: g). "-" In Table 1 indicates that no addition was made.

(Preparation of resin particles P-1)
First, a resin core was formed. In a round bottom flask (capacity: 1 L) equipped with an anchor type stirring blade, 135 g of styrene, 5 g of acrylic acid, 7 g of divinylbenzene, 10 g of a water-soluble polymerization initiator (potassium persulfate), and 20 g. ("Tween 20" manufactured by Tokyo Kasei Kogyo Co., Ltd., component: polyoxyethylene sorbitan monolaurate) and 375 g of ion-exchanged water were added. While stirring the contents of the flask at a rotation speed of 100 rpm, the temperature inside the flask was raised to 70 ° C. at a temperature rising rate of 1 ° C./min. The contents of the flask were stirred at a rotation speed of 100 rpm for 8 hours while keeping the temperature inside the flask at 70 ° C. While the temperature inside the flask was kept at 70 ° C., the contents of the flask reacted (specifically, emulsion polymerization). In this way, a dispersion liquid of the resin core was obtained. Using a centrifuge (“Micro-cooled centrifuge 3740” manufactured by Kubota Seisakusho Co., Ltd.), the obtained dispersion was centrifuged under the condition of 10000 times the gravitational acceleration (10000 G) for 30 minutes. Then, the solid phase containing the resin core A was recovered. The solid phase containing the obtained resin core A was not dried.

Next, a coat layer was formed. In another round-bottomed flask (capacity: 1 L) equipped with an anchor-type stirring blade, the total amount of the obtained resin core A (specifically, the solid phase containing the undried resin core A) and 15 g of oxazoline. Group-containing polymer aqueous solution (“Epocross WS-700” manufactured by Nippon Catalyst Co., Ltd., monomer mass ratio: methyl methacrylate / 2-vinyl-2-oxazoline / butyl acrylate = 4/5/1, solid content concentration: 25 mass %, Tg: 50 ° C.) and 500 mL of ion-exchanged water were added. Dilute hydrochloric acid was further added to the flask to adjust the pH of the flask contents to 4.0. While stirring the contents of the flask at a rotation speed of 100 rpm, the temperature inside the flask was raised to 70 ° C. at a temperature rising rate of 1 ° C./min. The contents of the flask were stirred at a rotation speed of 100 rpm for 3 hours while keeping the temperature inside the flask at 70 ° C. While the temperature inside the flask was kept at 70 ° C., the carboxyl group on the surface of the resin core A reacted with the oxazoline group contained in the oxazoline group-containing polymer aqueous solution. Then, the temperature in the flask was cooled to room temperature (25 ° C.). In this way, a dispersion liquid containing resin particles was obtained.

The obtained dispersion was suction filtered using a Büchner funnel. The obtained solid content was redispersed in ion-exchanged water. The obtained dispersion was suction filtered using a Büchner funnel. Such a solid-liquid separation treatment was performed 5 times. The obtained solid content was dried to obtain a mass containing resin particles. The obtained mass was pulverized using a supersonic jet crusher (“Jet Mill IDS-2” manufactured by Nippon Pneumatic Industries Co., Ltd.) under the condition of a pulverization pressure of 0.6 MPa. The collision plate of the supersonic jet crusher was a flat plate made of ceramic. In this way, resin particles P-1 were obtained. The obtained resin particles P-1 were powders composed of a large number of resin particles P-1.

(Preparation of resin particles P-2)
Instead of 135 g of styrene, 5 g of acrylic acid and 7 g of divinylbenzene, 128 g of methyl methacrylate, 6 g of methacrylic acid and 13 g of ethylene glycol dimethacrylate were added. The amount of potassium persulfate added was changed from 10 g to 8 g. The amount of Tween 20 added was changed from 20 g to 25 g. A resin core B was obtained in the same manner as in the production of the resin core A except that these were changed. Resin particles P-2 were obtained by the same method as for producing the resin particles P-1, except that the resin core B was used instead of the resin core A.

(Preparation of resin particles P-3)
Instead of 135 g of styrene, 135 g of acrylonitrile was added. A resin core C was obtained in the same manner as in the production of the resin core A except that this was changed. Resin particles P-3 were obtained by the same method as for producing the resin particles P-1, except that the resin core C was used instead of the resin core A.

(Preparation of resin particles P-4)
Instead of 135 g of styrene, 5 g of acrylic acid and 7 g of divinylbenzene, 128 g of 2,2,2-trifluoroacrylate, 6 g of methacrylic acid and 13 g of ethylene glycol dimethacrylate were added. The amount of potassium persulfate added was changed from 10 g to 5 g. A resin core D was obtained in the same manner as in the production of the resin core A except that these were changed. Resin particles P-4 were obtained by the same method as for producing the resin particles P-1, except that the resin core D was used instead of the resin core A.

(Preparation of resin particles P-5)
No coat layer was formed on the resin core A obtained by producing the resin particles P-1. The solid phase containing the resin core A obtained in the preparation of the resin particles P-1 was dried to obtain a mass containing the resin core A. The obtained mass was pulverized using a supersonic jet crusher (“Jet Mill IDS-2” manufactured by Nippon Pneumatic Industries Co., Ltd.) under the condition of a pulverization pressure of 0.6 MPa. The collision plate of the supersonic jet crusher was a flat plate made of ceramic. In this way, the resin core A was obtained. The obtained resin core A was used as the resin particles P-5. The resin particles P-5 were powders composed of a large number of resin particles P-5 (resin core A).

<Toner mother particle forming process>
(Preparation of toner mother particle M-1)
Using an FM mixer (“FM-20B” manufactured by Nippon Coke Industries Co., Ltd.), 10 parts by mass of crystalline polyester resin, 90 parts by mass of amorphous polyester resin, and 3 parts by mass of ester wax (Nippon Oil Co., Ltd.) "Nissan Electol (registered trademark) WEP-8" manufactured by the company) and 1 part by mass of positive charge control agent (quaternary ammonium salt, "BONTRON (registered trademark) P-51" manufactured by Orient Chemical Industries Co., Ltd.) , 6 parts by mass of carbon black (“MA100” manufactured by Mitsubishi Chemical Industries Co., Ltd.) was mixed to obtain a mixture. Using a twin-screw extruder (“PCM-30” manufactured by Ikegai Co., Ltd.), knead while melting the mixture under the conditions of a material supply speed of 6 kg / hour, a shaft rotation speed of 160 rpm, and a set temperature (cylinder temperature) of 120 ° C. And got the kneaded product. The kneaded product was cooled. Using a crusher (“Rotoplex (registered trademark)” manufactured by Hosokawa Micron Co., Ltd.), the cooled kneaded product was coarsely pulverized to obtain a coarsely pulverized product. A pulverized product was pulverized using a pulverizer (“Turbo Mill RS type” manufactured by Freund Turbo Co., Ltd.) to obtain a pulverized product. The finely pulverized product was classified using a classification machine (“Elbow Jet EJ-LABO type” manufactured by Nittetsu Mining Co., Ltd.). As a result, toner mother particles M-1 were obtained. _{The D 50} of the toner mother particles M-1 was 7 μm.

(Synthesis of amorphous polyester resin)
The amorphous polyester resin used for producing the toner mother particles M-1 was synthesized by the following method. Specifically, 1600 g of bisphenol A propylene oxide adduct, 550 g of bisphenol A ethylene oxide adduct, and 600 g in a 5 L 4-necked flask equipped with a thermometer, a dehydration tube, a nitrogen introduction tube, and a stirrer. N-dodecenyl succinic anhydride, 400 g of terephthalic acid, and 4 g of dibutyltin oxide were added. Subsequently, the flask contents were reacted at a temperature of 220 ° C. for 9 hours. Subsequently, the contents of the flask were reacted at a temperature of 280 ° C. for 4 hours under a reduced pressure of 8 kPa to obtain an amorphous polyester resin. The obtained amorphous polyester resin has a Tm of 126.9 ° C., a Tg of 56.8 ° C., an acid value of 10.9 mgKOH / g, a hydroxyl value of 32 mgKOH / g, and a Mw of 102394. And Mn was 4602.

(Synthesis of crystalline polyester resin)
The crystalline polyester resin used for producing the toner mother particles M-1 was synthesized by the following method. Specifically, 990 g of 1,4-butanediol, 242 g of 1,6-hexanediol, and 1480 g were placed in a 5 L 4-necked flask equipped with a thermometer, a dehydration tube, a nitrogen introduction tube, and a stirrer. Fumaric acid and 2.5 g of 1,4-benzenediol were added. Subsequently, the flask contents were reacted at a temperature of 170 ° C. for 5 hours. Subsequently, the flask contents were reacted at a temperature of 210 ° C. for 1.5 hours. Subsequently, the contents of the flask were reacted for 1 hour at a temperature of 210 ° C. under a reduced pressure of 8 kPa to obtain a crystalline polyester resin. The Tm of the crystalline polyester resin is 88.8 ° C., the Mp is 82 ° C., the crystallinity index (Tm / Mp) is 1.08, the acid value is 3.1 mgKOH / g, and the hydroxyl value is It was 19 mgKOH / g, Mw was 27500, and Mn was 3620.

(Preparation of toner mother particle M-2)
In a 1 liter round bottom flask, 300 g of toner mother particles M-1 and 5 g of an oxazoline group-containing polymer aqueous solution (“Epocross (registered trademark) WS-700” manufactured by Nippon Catalyst Co., Ltd., monomer mass ratio: methyl methacrylate / 2-Vinyl-2-oxazoline / butyl acrylate = 4/5/1, solid content concentration: 25% by mass, Tg: 50 ° C.) and 500 mL of ion-exchanged water were added. Dilute hydrochloric acid was further added to the flask to adjust the pH of the flask contents to 4.0. While stirring the contents of the flask at a rotation speed of 100 rpm, the temperature inside the flask was raised to 70 ° C. at a temperature rising rate of 1 ° C./min. The contents of the flask were stirred at a rotation speed of 100 rpm for 8 hours while keeping the temperature inside the flask at 70 ° C. While the temperature inside the flask was kept at 70 ° C., a shell layer containing an oxazoline group-containing polymer was formed on the surface of the toner mother particles M-1 (corresponding to the toner core). The contents of the flask were suction filtered using a Büchner funnel to obtain a solid content. The solid content was dispersed in ion-exchanged water. The obtained dispersion was suction filtered again using a Büchner funnel. Such a solid-liquid separation treatment was performed 5 times. The obtained solid content was dried to obtain toner mother particles M-2. The toner mother particle M-2 provided a shell layer covering the surface of the toner core (corresponding to the toner mother particle M-1), and the shell layer contained an oxazoline group.

<External addition process and bonding process>
The external addition step and the bonding step were performed using any of the resin particles P-1 to P-5 and any of the toner mother particles M-1 to M-2. As a result, toners TA-1 to TA-5 and TB-1 were produced. The configurations of the toners TA-1 to TA-5 and TB-1 are shown in Table 2 described later.

(Toner TA-1)
The external attachment process was as follows. An FM mixer (“FM-10B” manufactured by Nippon Coke Industries Co., Ltd.) contains 100.0 parts by mass of toner mother particles M-1, 1.0 parts by mass of resin particles P-1, and 1.2 parts by mass. Hydrophobic silica particles (“AEROSIL® RA-200H” manufactured by Nippon Aerosil Co., Ltd.) were added. The toner mother particles M-1, the resin particles P-1, and the hydrophobic silica particles were mixed under the conditions of a rotation speed of 3000 rpm, a jacket temperature of 20 ° C., and a mixing time of 2 minutes. In this way, the resin particles P-1 and the hydrophobic silica particles were adhered to the surface of the toner mother particles M-1. As a result, toner mother particles M-1 to which resin particles P-1 and hydrophobic silica particles were attached (hereinafter, referred to as resin particle-attached toner mother particles) were obtained.

The joining process was as follows. Hereinafter, the reaction apparatus 100 used in the bonding step will be described with reference to FIG. The reaction apparatus 100 includes a reaction vessel 101, a stirring blade 102, a catalyst vessel 104, a pressure gauge 105, a vacuum pump 106, a first connecting pipe 109, a second connecting pipe 107, and a third connecting pipe 108. , A first cock 111 and a second cock 110 are provided. The reaction vessel 101 contains the toner mother particles T to which the resin particles are attached. The stirring blade 102 is arranged in the reaction vessel 101. The stirring blade 102 stirs the resin particle-adhered toner mother particles T in the reaction vessel 101. The catalyst container 104 houses the acid catalyst X. The reaction vessel 101 is connected to the vacuum gauge 105 via the third connecting pipe 108. The vacuum gauge 105 is connected to the vacuum pump 106 via the first connecting pipe 109. The vacuum pump 106 depressurizes the inside of the reaction vessel 101 via the third connecting pipe 108 and the first connecting pipe 109. The vacuum gauge 105 measures the internal pressure of the reaction vessel 101. The reaction vessel 101 is connected to the catalyst vessel 104 via the second connecting pipe 107. The first cock 111 opens and closes the first connecting pipe 109. The second cock 110 opens and closes the second connecting pipe 107.

Subsequently, the bonding process will be described with reference to FIG. The first cock 111 and the second cock 110 of the reactor 100 were closed, respectively. Next, 300 g of the resin particle-adhered toner mother particles T obtained in the external addition step were placed in the reaction vessel 101. 50 mg of acid catalyst X (specifically, concentrated hydrochloric acid) was placed in the catalyst container 104. The reaction vessel 101 and the catalyst vessel 104 were each sealed. The stirring blade 102 in the reaction vessel 101 was rotated at a rotation speed of 60 rpm. The vacuum pump 106 was driven. The first cock 111 was opened with the second cock 110 closed. As a result, the pressure inside the reaction vessel 101 was reduced. When the internal pressure of the reaction vessel 101 indicated by the vacuum gauge 105 reached 0.3 Pa, the first cock 111 was closed and the second cock 110 was opened. As a result, the acid catalyst X (specifically, concentrated hydrochloric acid) in the catalyst container 104 was vaporized to generate a gaseous acid catalyst X (specifically, gaseous hydrogen chloride). The gaseous acid catalyst X flowed into the reaction vessel 101 through the second connecting tube 107. After the internal pressure of the reaction vessel 101 indicated by the vacuum gauge 105 did not change, the second cock 110 was closed and the first cock 111 was opened. As a result, the internal pressure of the reaction vessel 101 was adjusted to 0.3 Pa. The reaction vessel 101 was kept for 5 minutes while the internal pressure of the reaction vessel 101 was 0.3 Pa. While holding for 5 minutes, the resin particles and the toner mother particles contained in the resin particle-attached toner mother particles T were covalently bonded to each other. Specifically, while gaseous hydrogen chloride acts as an acid catalyst, the oxazoline group contained in the coat layer of the resin particles reacts (specifically, the dehydration reaction) with the carboxyl group on the surface of the toner matrix particles. A first amide bond was formed. As a result, toner TA-1 was obtained. As for the toner particles contained in the toner TA-1, the resin particles P-1 and the toner mother particles M-1 were bonded to each other by the first amide bond. The joining process has been described above with reference to FIG.

(Toner TA-2)
In the external addition step, the resin particles P-1 were changed to the resin particles P-2. Toner TA-2 was obtained by the same method as the external addition step and the bonding step of the toner TA-1 except that this was changed.

(Toner TA-3)
In the external addition step, the resin particles P-1 were changed to the resin particles P-3. Toner TA-3 was obtained by the same method as the external addition step and the bonding step of the toner TA-1 except that this was changed.

(Toner TA-4)
In the external addition step, the resin particles P-1 were changed to the resin particles P-4. Toner TA-4 was obtained by the same method as the external addition step and the bonding step of the toner TA-1 except that this was changed.

(Toner TA-5)
In the external addition step, the toner mother particle M-1 was changed to the toner mother particle M-2, and the resin particle P-1 was changed to the resin particle P-5. Toner TA-5 was obtained by the same method as the external addition step and the bonding step of the toner TA-1 except that these were changed. In the external addition step of the toner TA-5, the gaseous hydrogen chloride acts as an acid catalyst, and the oxazoline group contained in the shell layer of the toner mother particle M-2 and the surface of the resin particle P-5 The carboxyl group reacted (specifically, a dehydration reaction) to form a first amide bond.

(Toner TB-1)
The toner TB-1 externalizing step was performed in the same manner as the toner TA-1 externalizing step. Next, the bonding step was performed in the production of the toner TA-1, but the bonding step was not performed in the production of the toner TB-1. The toner mother particles M-1 to which the resin particles P-1 and the hydrophobic silica particles were attached, which were obtained in the external addition step, were used as the toner TB-1. In the toner particles contained in the toner TB-1, the resin particles P-1 were only physically attached to the toner mother particles M-1. In the toner particles contained in the toner TB-1, the resin particles P-1 and the toner mother particles M-1 were not bonded to each other by the first amide bond.

[Measuring method]
<Measurement of average primary particle size of resin particles>
The sample (resin particles) was dispersed in a room temperature curable epoxy resin and cured in an atmosphere of 40 ° C. for 2 days to obtain a cured product. The obtained cured product was stained with osmium tetroxide and then cut out using an ultramicrotome equipped with a diamond knife (“EM UC6” manufactured by Leica Microsystems, Inc.) to obtain a flaky sample having a thickness of 200 nm.

A cross section of a flaky sample was photographed using a field emission transmission electron microscope (TEM, "JEM-2100F" manufactured by JEOL Ltd.) under the conditions of an acceleration voltage of 200 kV and a magnification of 1,000,000 times to obtain a TEM photograph. TEM photographs of 100 or more resin particles were taken. From the obtained TEM photographs, TEM photographs of 100 resin particles were randomly selected. For the selected TEM photographs, the equivalent circle diameters of 100 resin particles were measured using image analysis software (“WinROOF” manufactured by Mitani Shoji Co., Ltd.). The average number of circle-equivalent diameters of the resin particles was calculated by dividing the sum of the measured circle-equivalent diameters of the 100 resin particles by the number of measurements (100). The calculated number average value was taken as the number average primary particle diameter of the resin particles. The calculation results are shown in Table 2.

<Measurement of coating layer thickness of resin particles>
A flaky sample of a sample (resin particles) was obtained by the same method as in the above <Measurement of average primary particle size of number of resin particles>. Then, a cross section of the flaky sample was photographed using a field emission transmission electron microscope (TEM, "JEM-2100F" manufactured by JEOL Ltd.) under the conditions of an acceleration voltage of 200 kV and a magnification of 1,000,000 times. Next, an electron energy loss spectroscopy (EELS) detector with an energy resolution of 1.0 eV and a beam diameter of 1.0 nm ("GIF TRIDEIM (registered trademark)" manufactured by Gatan) and image analysis software ("Mitani Shoji Co., Ltd." TEM photographs were analyzed using WinROOF 5.5.0 ”) to obtain distribution images of nitrogen elements. The nitrogen element was a characteristic element contained in the coat layer. Distribution images of nitrogen elements were obtained for 100 or more resin particles. From the obtained distribution images of nitrogen elements, distribution images of nitrogen elements of 100 resin particles were arbitrarily selected. The thickness of the coat layer contained in one resin particle was determined for each of the distribution images of arbitrarily selected nitrogen elements. The average number of the thicknesses of the coat layers of the resin particles was calculated by dividing the sum of the measured thicknesses of the coat layers of the 100 resin particles by the number of measurements (100). The calculated average number was taken as the thickness of the coat layer of the resin particles. The calculation results are shown in Table 2.

<Measurement of shell layer thickness of toner matrix particles>
The thickness of the shell layer of the toner mother particles was measured by the same method as the measurement of the thickness of the coat layer of the resin particles, except that the sample was changed from the resin particles to the toner mother particles. From the measurement results, the number average value of the thickness of the shell layer of the toner mother particles was calculated. The calculated average number was taken as the thickness of the shell layer of the toner mother particles. The calculation results are shown in Table 2.

<Measurement of the amount of unopened ring oxazoline group in resin particles>
Gas chromatography-mass spectrometry (GC / MS method) was performed on the resin particles. As the resin particles to be measured, each of the resin particles P-1 to P-5 after the resin particle forming step and before the externalizing step was used. In the GC / MS method, as measuring devices, a gas chromatograph mass spectrometer (“GCMS-QP2010 Ultra” manufactured by Shimadzu Corporation) and a multi-shot pyrolyzer (“FRONTIER LAB Multi-functional Pyrollyzer” manufactured by Frontier Lab Co., Ltd.) (registered) Trademark) PY-3030D ") was used. As a column, a GC column (“Agilent® J & W Ultoliner to Capillari GC Column DB-5ms” manufactured by Agilent Technologies, Inc., phase: an arylene phase in which arylene is added to a siloxane polymer to strengthen the main chain of the polymer, inner diameter: 0 .25 mm, film thickness: 0.25 μm, length: 30 m) was used. The measurement conditions by the GC / MS method were as follows.

(Gas chromatograph)
-Carrier gas: Helium (He) gas-Carrier flow rate: 1 mL / min-Vaporization chamber temperature: 210 ° C
-Pyrolysis temperature: Heating furnace "600 ° C", interface "320 ° C"
Temperature temperature condition: After holding at 40 ° C. for 3 minutes, the temperature was raised from 40 ° C. to 300 ° C. at a rate of 10 ° C./min and held at 300 ° C. for 15 minutes.

(Mass spectrometry)
-Ionization method: EI (Electron Impact) method-Ion source temperature: 200 ° C
-Interface temperature: 320 ° C
-Detection mode: Scan (Measurement range: 45 m / z to 500 m / z)

The mass spectrum measured under the above conditions was analyzed to determine the peak area derived from the unopened ring oxazoline group. The amount (unit: mmоl) of the unopened ring oxazoline group was determined from the peak area derived from the unopened ring oxazoline group. For the quantification, an oxazoline group-containing polymer aqueous solution (“Epocross WS-700” manufactured by Nippon Shokubai Co., Ltd.) dried to an absolute dry state was used as a standard substance. It is known that the amount of unopened ring oxazoline group of Epocross WS-700 in the solid state is 4.5 mmоl / g. From the mass of the resin particles used for the measurement (unit: g) and the quantified amount of unopened ring oxazoline groups (unit: mmоl), the amount of unopened ring oxazoline groups contained in 1 g of the resin particles (unit: mmоl / g). ) Was asked. The calculation results are shown in Table 2.

<Measurement of the amount of unopened ring oxazoline group in the toner mother particle>
The amount of the unopened ring oxazoline group of the toner mother particle was measured by the same method as the above <Measurement of the amount of the unopened ring oxazoline group of the resin particle> except that the measurement target was changed from the resin particle to the toner mother particle. As the toner mother particles to be measured, each of the toner mother particles M-1 and M-2 after the toner mother particle forming step and before the external addition step was used. From the mass of the toner matrix particles used for the measurement (unit: g) and the quantified amount of unopened ring oxazoline groups (unit: mmоl), the amount of unopened ring oxazoline groups contained in 1 g of the toner matrix particles (unit: mmоl). / G) was calculated. The calculation results are shown in Table 2.

<Method of confirming the presence or absence of amide bond (first method)>
The toner was measured by the attenuated total reflection (ATR) method using a Fourier transform infrared spectrophotometer (FT-IR), and an IR spectrum was obtained. As the toner to be measured, each of the toners TA-1 to TA-5 and TB-1 was used. As FT-IR, "FTS-60A / 896" manufactured by Agilent Technologies, Inc. was used. The measurement conditions for FT-IR were as follows.

(FT-IR measurement conditions)
Attachment: 1-reflection ATR attachment ("Silver Gate" manufactured by Specac)
Optical crystal: Ge
Incident angle: 45 °
Resolution: 4 cm ^-1
Accumulation number: 128 times

From the obtained IR spectrum, ^{the absorbance of the peak of 1680 cm -1} and the absorbance of the peak of 1630 cm ^-1 were determined. The absorbance of the peak at 1680 cm- ¹ is the absorbance of the peak derived from the unopened ring oxazoline group. The absorbance of the peak of 1630 cm ^-1 is the absorbance of the peak derived from the amide bond formed by the reaction of the carboxyl group and the unopened ring oxazoline group.

For the toners TA-1 to TA-5 and TB-1, ^{if a peak of 1680 cm-1} was confirmed in the obtained IR spectrum, it was estimated that the unit (A) was present in the coat layer of the resin particles.

For toners TA-1 to TA-4, ^{if a peak of 1630 cm -1} was confirmed in the obtained IR spectrum, it was estimated that the first amide bond and the second amide bond were present. For toners TA-1 to TA-4, ^{if a peak of 1630 cm-1} was confirmed in the obtained IR spectrum, it was estimated that units (B1) and units (C) were present in the coat layer of the resin particles. ..

For toner TA-5, ^{if a peak of 1630 cm -1} was confirmed in the obtained IR spectrum, it was estimated that the first amide bond was present. Further, for the toner TA-5, ^{if a peak of 1630 cm -1} was confirmed in the obtained IR spectrum, it was estimated that the unit (B2) was present in the shell layer of the toner mother particles.

For toner TB-1, ^{if a peak of 1630 cm -1} was confirmed in the obtained IR spectrum, it was estimated that a second amide bond was present. Further, for the toner TB-1, ^{if a peak of 1630 cm -1} was confirmed in the obtained IR spectrum, it was estimated that the unit (C) was present in the coat layer of the resin particles. In addition, in the production of the toner TB-1, the bonding step was not carried out. Therefore, ^{it was presumed that the peak of 1630 cm -1} was derived from the second amide bond, not the first amide bond. For the same reason, ^{it was estimated that the peak at 1630 cm -1} was derived from the unit (C) rather than the unit (B1).

Table 2 shows the confirmation results of the presence / absence of the unit (A), the unit (B1), the unit (B2), and the unit (C).

<Method of confirming the presence or absence of amide bond (second method)>
An aqueous solution (concentration: 2% by mass) of a nonionic surfactant (“Emulgen (registered trademark) 120” manufactured by Kao Co., Ltd., component: polyoxyethylene lauryl ether) is diluted 10-fold with water to prepare an aqueous surfactant solution. Prepared. 10 g of toner was dispersed in 500 mL of the obtained aqueous surfactant solution to obtain a toner dispersion liquid. As the toner to be measured, each of the toners TA-1 to TA-5 and TB-1 was used.

The obtained toner dispersion was subjected to ultrasonic treatment for 5 minutes using an ultrasonic disperser (“Ultrasonic Mini Welder P128” manufactured by Ultrasonic Industry Co., Ltd., output: 100 W, oscillation frequency: 28 kHz). As a result, a dispersion liquid after ultrasonic treatment was obtained. The dispersion after sonication was centrifuged using a centrifuge. The solid phase contained in the liquid after centrifugation was visually confirmed. If the solid phase was separated into two layers (specifically, a layer of toner mother particles and a layer of silica particles), it was presumed that a covalent bond existed between the resin particles and the toner mother particles. If the solid phase is separated into three layers (specifically, a layer of toner mother particles, a layer of silica particles, and a layer of resin particles), a covalent bond exists between the resin particles and the toner mother particles. I presumed that it was not.

For toners TA-1 to TA-4, the solid phase was separated into two layers. From this, it was presumed that a covalent bond existed between the resin particles and the toner mother particles. From the confirmation result of the second method and the confirmation result of the first method, the toners TA-1 to TA-4 have a first amide bond and a second amide bond, and the coat layer of the resin particles has a unit (B1). ) And the unit (C) were shown to exist.

For the toner TA-5, the solid phase was separated into two layers. From this, it was presumed that a covalent bond existed between the resin particles and the toner mother particles. From the confirmation result of the second method and the confirmation result of the first method, it is shown that the first amide bond is present in the toner TA-5 and the unit (B2) is present in the shell layer of the toner mother particles. rice field.

For toner TB-1, the solid phase was separated into three layers. From this, it was estimated that there was no covalent bond between the resin particles and the toner mother particles. From the confirmation result of the second method and the confirmation result of the first method, the toner TB-1 does not have the first amide bond but the second amide bond exists, and the unit (B1) is present in the coat layer of the resin particles. It was shown that there is no unit (C) but there is a unit (C).

[Evaluation method]
<Evaluation of toner charge amount and toner scattering amount>
The toner charge amount and the toner scattering amount were evaluated for each of the toners TA-1 to TA-5 and TB-1 by the following method.

(Preparation of evaluation target)
Using a ball mill, 100 parts by mass of a carrier (carrier for "TASKalfa8002i" manufactured by Kyocera Document Solutions Co., Ltd.) and 10 parts by mass of toner (more specifically, toners TA-1 to TA-5 and TB-1). Each) and was mixed for 30 minutes. In this way, the evaluation target was obtained.

(Preparation of evaluation machine)
A multifunction device ("TASKalfa8002i" manufactured by Kyocera Document Solutions Co., Ltd.) was prepared. The evaluation target was placed in the black developing device of the multifunction device, and the replenishing toner was placed in the black toner container of the multifunction device. As the replenishing toner, the same toner as the toner included in the evaluation target was used. That is, the replenishing toner was any of the toners TA-1 to TA-5 and TB-1. In this way, the evaluation machine was prepared.

(Measurement of toner charge amount and toner scattering amount)
An image (printing rate: 5%) was continuously printed on plain paper (A4 size) using an evaluation machine in an environment of a temperature of 28 ° C. and a humidity of 80% RH (high temperature and high humidity environment). Then, the evaluation image was printed on plain paper (A4 size) using an evaluation machine in an environment of a temperature of 28 ° C. and a humidity of 80% RH. The evaluation image included a solid image portion and a blank paper portion (area without printing). Then, the toner charge amount was measured by the method shown below. In addition, the amount of toner scattered was measured by the method shown below.

The method of measuring the toner charge amount is shown. First, the evaluation target was taken out from the developing device of the evaluation machine. Next, 0.10 g of an evaluation target (more specifically, a two-component developer) was put into the measurement cell of the Q / m meter (“MODEL 210HS-1” manufactured by Trek Co., Ltd.), and only the toner was selected from the evaluation targets. It was sucked through a sieve (wire mesh) for 10 seconds. Then, the toner charge amount (unit: μC / g) was calculated based on the following formula.
Toner charge amount (unit: μC / g) = total electric amount of sucked toner (unit: μC) / mass of sucked toner (unit: g)

The method of measuring the amount of toner scattering is shown. Specifically, the mass of the toner recovered in the evaluation machine was measured using an electronic balance (“GF-3000” manufactured by A & D Co., Ltd.). More specifically, the evaluator was further equipped with a suction fan and a collection container. The suction fan was a device that sucks toner (for example, scattered toner) that is not excellent in the state of being adsorbed on the developing roller around the developing roller of the developing device. The collection container was connected to a suction fan and was a container for collecting the toner sucked by the suction fan. Then, the mass of the toner collected in the collection container was measured using an electronic balance.

The evaluation criteria for the amount of toner charged are shown below.
Good: The toner charge amount was 18.0 μC / g or more.
Defective: The toner charge amount was less than 18.0 μC / g.

The evaluation criteria for the amount of toner scattered are shown below.
Good: The amount of toner scattered was 5 g or less.
Defective: The amount of toner scattered was more than 5 g.

[Evaluation results]
Table 2 shows the evaluation results of the toner charge amount and the toner scattering amount. In Table 2, "particle size" indicates the number average primary particle size of the resin particles. In Table 2, "amount of oxazoline group" indicates the amount of unopened ring oxazoline group. In Table 2, "Yes" and "No" in the "Unit (A)" column of "Coat layer" indicate that the presence of unit (A) was confirmed in the coat layer and that it was not confirmed, respectively. show. In Table 2, "Yes" and "No" in the "Unit (B1)" column of "Coat layer" indicate that the presence of the unit (B1) was confirmed in the coat layer and that it was not confirmed, respectively. show. In Table 2, "Yes" and "No" in the "Unit (C)" column of "Coat layer" indicate that the presence of unit (C) was confirmed in the coat layer and that it was not confirmed, respectively. show. In Table 2, "Yes" and "No" in the "Unit (A)" column of "Shell layer" indicate that the existence of the unit (A) was confirmed in the shell layer and that it was not confirmed, respectively. show. In Table 2, "Yes" and "No" in the "Unit (B2)" column of "Shell layer" indicate that the existence of the unit (B2) was confirmed in the shell layer and that it was not confirmed, respectively. show. In Table 2, "Yes" in the "Covalent bond between the resin particle and the toner mother particle" column indicates the covalent bond between the resin particle and the toner mother particle (specifically, the unit (B1) or (B2)). Indicates that has been confirmed. In Table 2, "None" in the "Covalent bond between the resin particle and the toner mother particle" column indicates the covalent bond between the resin particle and the toner mother particle (specifically, the unit (B1) or (B2)). Indicates that was not confirmed.

As shown in Table 2, in each of the toners TA-1 to TA-5, the toner particles included a toner mother particle and an external additive provided on the surface of the toner mother particle. The external additive contained resin particles. The resin particles and the toner mother particles were covalently bonded to each other. Therefore, as shown in Table 2, when an image is formed in a high temperature and high humidity environment using each of the toners TA-1 to TA-5, the toner charge amount is within a desired range even after printing 300,000 sheets. The value could be maintained, and the amount of toner scattered could be suppressed below the desired value.

On the other hand, as shown in Table 2, in the toner TB-1, the resin particles and the toner mother particles were not bonded to each other by covalent bonds. Therefore, as shown in Table 2, when an image is formed in a high temperature and high humidity environment using the toner TB-1, the toner charge amount falls below the desired range after printing 300,000 sheets, and the toner scattering amount is a desired value. Beyond.

From the above, the toners TA-1 to TA-5 can maintain the toner charge amount within a desired range and suppress the toner scattering amount to a desired value or less as compared with the toner TB-1. Shown. From this, it was shown that the toner according to the present invention is excellent in charge stability.

The toner according to the present invention can be used for forming an image in, for example, a copying machine, a printer, or a multifunction device.

10, 20, 30: Toner particles 11, 21, 31: Toner mother particles 12, 22, 32: Resin particles 23: Resin core 24: Coat layer 33: Toner core 34: Shell layer Y1: First amide bond Y2: Second Amide bond Y3: Third amide bond

Claims (11)

Contains toner particles
The toner particles include a toner mother particle and an external additive provided on the surface of the toner mother particle.
The external additive contains resin particles and contains resin particles.
The resin particles and the toner mother particles are covalently bonded to each other .
One of the toner mother particles and the resin particles contains a portion of the first vinyl resin, and the toner mother particles and the resin particles contain a portion of the first vinyl resin.
The other of the toner mother particles and the resin particles has a carboxyl group on the surface and has a carboxyl group.
The portion of the first vinyl resin includes a unit represented by the following formula (A) and a unit represented by the following formula (B').
The covalent bond is a first amide bond and is
The first amide bond is a positively charged toner which is an amide bond contained in the unit represented by the formula (B').

(In the formula (A), R ¹ represents a hydrogen atom or an optionally substituted alkyl group.)

(In the formula (B ' ), R ¹ represents the same group as ^{R 1} in the formula (A).
When the resin particles contain the portion of the first vinyl resin, * ² represents a bond that binds to an atom constituting the toner mother particle.
When the toner mother particles contain a portion of the first vinyl resin, * ² represents a bond that binds to an atom constituting the resin particles. ) The resin particles contain the portion of the first vinyl resin, and the toner mother particles have the carboxyl group on the surface.
The resin particles have a resin core and a coat layer that covers the surface of the resin core.
The portion of the first vinyl resin is contained in the coat layer and is contained in the coat layer.
The unit represented by the above formula (B ' ) is the unit represented by the following formula (B1 ' ).
The positively charged toner according to claim 1 , wherein the first amide bond is an amide bond contained in a unit represented by the formula (B1').

(In the formula (B1 ' ), R ¹ represents the same group as ^{R 1} in the formula (A) , and * ²¹ represents a bond that binds to an atom constituting the toner mother particle.) The resin core has a carboxyl group and has a carboxyl group.
The portion of the first vinyl resin contained in the coat layer further contains a unit represented by the following formula (C ').
The resin core and the coat layer are bonded to each other by a second amide bond.
The positively charged toner according to claim 2 , wherein the second amide bond is an amide bond contained in a unit represented by the formula (C').

(In the formula (C ' ), R ¹ represents the same group as ^{R 1} in the formula (A) , and * ³ represents a bond that binds to an atom constituting the resin core.) The positively charged toner according to claim 2 or 3 , wherein the resin core contains a second vinyl resin having a carboxyl group. The positively charged toner according to any one of claims 2 to 4 , wherein the thickness of the coat layer is 3.0 nm or less. The positively charged toner according to any one of claims 2 to 5 , wherein the average primary particle diameter of the number of the resin particles is 60 nm or more and 120 nm or less. The toner mother particles contain the portion of the first vinyl resin, and the resin particles have the carboxyl group on the surface.
The toner mother particles have a toner core and a shell layer covering the surface of the toner core.
The portion of the first vinyl resin is contained in the shell layer and is contained in the shell layer.
The unit represented by the above formula (B ' ) is the unit represented by the following formula (B2 ' ).
The positively charged toner according to claim 1 , wherein the first amide bond is an amide bond contained in a unit represented by the formula (B2').

(In the formula (B2 ' ), R ¹ represents the same group as ^{R 1} in the formula (A) , and * ²² represents a bond that binds to an atom constituting the resin particle.) The positively charged toner according to claim 7 , wherein the resin particles contain the second vinyl resin having a carboxyl group. An external addition process in which an external additive containing resin particles is attached to the surface of the toner matrix particles,
Wherein the resin particles toner base particles and bonded together by a covalent bond to, look including a coupling step to form toner particles,
One of the toner mother particles and the resin particles contains a portion of the first vinyl resin, and the toner mother particles and the resin particles contain a portion of the first vinyl resin.
The other of the toner mother particles and the resin particles has a carboxyl group on the surface and has a carboxyl group.
The portion of the first vinyl resin contains a unit represented by the following formula (A).
In the bonding step, the unit represented by the formula (A) and the carboxyl group of the first vinyl resin portion are reacted in the presence of an acid catalyst, thereby being represented by the following formula (B'). Units are formed, and the resin particles and the toner mother particles are bonded to each other by the covalent bond.
The covalent bond is a first amide bond and is
The first amide bond is a method for producing a positively charged toner, which is an amide bond contained in a unit represented by the formula (B').

(In the formula (A), R ¹ represents a hydrogen atom or an optionally substituted alkyl group.)

(In the formula (B ' ), R ¹ represents the same group as ^{R 1} in the formula (A).
When the resin particles contain the portion of the first vinyl resin, * ² represents a bond that binds to an atom constituting the toner mother particle.
When the toner mother particles contain a portion of the first vinyl resin, * ² represents a bond that binds to an atom constituting the resin particles. ) The ninth aspect of claim 9, wherein the amount of the unopened ring oxazoline group contained in 1 g of the resin particles before the bonding step is 0.002 mmol / g or more and 5.000 mmol / g or less as measured by gas chromatography-mass spectrometry. Method for manufacturing positively charged toner. The method for producing a positively charged toner according to claim 9 or 10 , wherein the acid catalyst is gaseous hydrogen chloride.

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