CN117321507A

CN117321507A - Toner for developing electrostatic charge image, electrostatic charge image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method

Info

Publication number: CN117321507A
Application number: CN202280034989.0A
Authority: CN
Inventors: 坂元梓也; 岩濑优辉; 田中佑实
Original assignee: Fujifilm Business Innovation Corp
Current assignee: Fujifilm Business Innovation Corp
Priority date: 2021-09-27
Filing date: 2022-09-26
Publication date: 2023-12-29

Abstract

In a dynamic viscoelasticity measurement of a toner for developing an electrostatic charge image, D1 (90), D50 (90), D1 (150) and D50 (150) are respectively set to 0.5 to 2.5, the value of D50 (150) -D1 (150) is set to D50 (90), the value of D50 (90) -D1 (90) is set to D50 (90), the loss tangent tan delta of 150 ℃ and 1% is set to D1 (150), and the loss tangent tan delta of 150 ℃ and 50% is set to D50 (150), wherein the values of D1 (90), D50 (90), D1 (150) and D50 (150) are respectively set to 0.5 to 2.5, D50 (150) -D1 (150) are set to less than 1.5, and the value of D50 (90) -D1 (90) is set to less than 1.0.

Description

Toner for developing electrostatic charge image, electrostatic charge image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method

Technical Field

The invention relates to an electrostatic charge image developing toner, an electrostatic charge image developer, a toner cartridge, a process cartridge, an image forming apparatus, and an image forming method.

Background

Patent document 1 discloses a toner for developing an electrostatic latent image, which contains toner particles containing a binder resin, wherein the binder resin contains an amorphous resin and a crystalline resin, and the dynamic viscoelasticity is measured by strain dispersion under conditions of a temperature of 130 ℃, a frequency of 1Hz, and a strain amplitude of 1.0 to 500%, and the integrated value of stress in a stress-strain curve at a strain amplitude of 100% is S130, and the slope of the long diameter is θ130, and the S130 exceeds 0Pa and is 350000Pa or less, and the θ130 exceeds 22 ° and is smaller than 90 °.

Patent document 2 discloses a toner for developing an electrostatic charge image, which contains at least a binder resin and a release agent, wherein the binder resin contains at least a crystalline resin, and the toner has a storage modulus satisfying a specific relationship when measured by changing strain from 0.01% to 1000% at a frequency of 1Hz and 150 ℃.

Patent document 3 discloses a toner for developing an electrostatic latent image, which contains toner particles containing a binder resin, wherein the binder resin contains an amorphous vinyl resin and a crystalline resin, and the dynamic viscoelasticity is measured by strain dispersion under conditions of a temperature of 130 ℃, a frequency of 1Hz, and a strain amplitude of 1.0 to 500%, and the integrated value of stress of a stress-strain curve at a strain amplitude of 100% is S130, and when the slope of the long diameter is θ130, the S130 exceeds 0Pa and is 350000Pa or less, and the θ130 is 0 ° or more and less than 10 °.

Patent document 4 discloses an electrostatic charge image developing toner comprising a toner base particle containing at least a binder resin and a release agent and an external additive, wherein the binder resin contains at least a crystalline resin, and the peak value tan delta 6 ℃/min of the loss tangent measured at a frequency of 1Hz and a temperature rise rate of 6 ℃/min from 25 ℃ to 100 ℃ and the peak value tan delta 3 ℃/min of the loss tangent measured at a frequency of 1Hz and a temperature rise rate of 3 ℃/min from 25 ℃ to 100 ℃ in the electrostatic charge image developing toner satisfy a specific relationship.

Patent document 5 discloses an electrostatic charge image developing toner comprising at least a binder resin, a colorant and a releasing agent, wherein the toner has a change rate γg 'of a storage modulus G' of 50% < γg '< 86%, a change rate γg "of a loss modulus G" of more than 50%, and a storage modulus G' of 5×10 in a range of 1 to 50% strain at a temperature of 150 ℃ ² ～3.5×10 ³ Pa·s, wherein the binder resin comprises an amorphous resin and a crystalline resin.

Patent documents 6 and 7 disclose toner for developing electrostatic charge images, which is composed of toner particles containing a binder resin, wherein the binder resin has a domain/matrix structure composed of a high-elasticity resin constituting domains and a low-elasticity resin constituting a matrix, and the arithmetic average value of the ratio (L/W) of the long diameter L to the short diameter W of each domain is in the range of 1.5 to 5.0, 80% or more domains exist in the range of 60 to 500nm, and 80% or more domains exist in the range of 45 to 100nm in an elastic image based on an Atomic Force Microscope (AFM) with respect to the cross section of the toner particles.

Technical literature of the prior art

Patent literature

Patent document 1: japanese patent laid-open No. 2020-042122

Patent document 2: japanese patent laid-open No. 2020-106685

Patent document 3: japanese patent laid-open No. 2020-042121

Patent document 4: japanese patent application laid-open No. 2019-144368

Patent document 5: japanese patent laid-open publication No. 2013-160886

Patent document 6: japanese patent laid-open publication No. 2011-237793

Patent document 7: japanese patent laid-open publication No. 2011-237792

Disclosure of Invention

Technical problem to be solved by the invention

In image formation using an electrostatic charge image developing toner, for example, a toner image transferred onto a recording medium is fixed on the recording medium by heating and pressurizing. In the case of using an electrostatic charge image developing toner containing toner particles that are easily melted by heating to obtain good fixability, the difference between the glossiness of a fixed image fixed under high-temperature and high-pressure conditions and the glossiness of a fixed image fixed under low-temperature and low-pressure conditions sometimes becomes large.

The technical problem of the present invention is to provide a toner for developing an electrostatic charge image, which can obtain good fixability and has a small difference in glossiness between a fixed image under low-temperature and low-pressure conditions and a fixed image under high-temperature and high-pressure conditions, compared with the case where any one of D1 (90), D50 (90), D1 (150) and D50 (150) is less than 0.5 or more, the value of D50 (150) -D1 (150) is 1.5 or more, the case where the toner particles contain no resin particles, or the case where the number average molecular weight of tetrahydrofuran soluble component in the toner particles is less than 5000 or more than 15000.

Means for solving the technical problems

The above technical problems are solved by the following method. That is to say,

＜1＞

a toner for developing an electrostatic charge image, comprising toner particles containing a binder resin, wherein,

in the dynamic viscoelasticity measurement of the toner for developing electrostatic charge image, when the loss tangent tan delta at 90 ℃ and strain amount of 1% is D1 (90), the loss tangent tan delta at 90 ℃ and strain amount of 50% is D50 (90), the loss tangent tan delta at 150 ℃ and strain amount of 1% is D1 (150), the loss tangent tan delta at 150 ℃ and strain amount of 50% is D50 (150),

d1 (90), D50 (90), D1 (150) and D50 (150) are respectively more than 0.5 and less than 2.5,

d50 The values of (150) -D1 (150) are less than 1.5,

d50 The value of (90) -D1 (90) is less than 1.0,

the toner particles further contain resin particles,

the tetrahydrofuran soluble component in the toner particles has a number average molecular weight of 5000 or more and 15000 or less.

＜2＞

The toner for developing an electrostatic charge image according to < 1 >, wherein,

the glass transition temperature Tg of the resin particles, which is determined by dynamic viscoelasticity measurement, is 10 ℃ to 45 ℃.

＜3＞

The toner for developing an electrostatic charge image according to < 1 > or < 2 >, wherein,

In the dynamic viscoelasticity measurement of the resin particles at a temperature rise of 2 ℃/min, the loss tangent tan delta in the range of 30 ℃ to 150 ℃ is 0.01 to 2.5.

＜4＞

The toner for developing an electrostatic charge image according to any one of < 1 > - < 3 >, wherein,

the number average particle diameter of the resin particles is 60nm to 300 nm.

＜5＞

The toner for developing an electrostatic charge image according to any one of < 1 > - < 4 >, wherein,

the content of the resin particles is 2 mass% or more and 30 mass% or less relative to the entire toner particles.

＜6＞

The toner for developing an electrostatic charge image according to any one of < 1 > - < 5 >, wherein,

the resin particles are crosslinked resin particles.

＜7＞

The toner for developing an electrostatic charge image according to < 6 >, wherein,

the crosslinked resin particles are styrene (meth) acrylic resin particles.

＜8＞

The toner for developing an electrostatic charge image according to any one of < 1 > - < 7 >, wherein,

the difference (SP value (S) -SP value (R)) between the solubility parameter SP value (S) of the resin particles and the solubility parameter SP value (R) of the binder resin is-0.32 or more and-0.12 or less.

＜9＞

The toner for developing an electrostatic charge image according to any one of < 1 > - < 8 >, wherein,

in a dynamic viscoelasticity measurement of the components of the toner particles from which the resin particles are removed at a temperature rise of 2 ℃ per minute, a storage modulus G' in a range of 30 ℃ to 50 ℃ inclusive is 1×10 ⁸ Pa or more, and a storage modulus G' of less than 1×10 ⁵ Pa is 65 ℃ to 90 ℃.

＜10＞

The toner for developing an electrostatic charge image according to < 9 >, wherein,

in a dynamic viscoelasticity measurement of the component from which the resin particles are removed from the toner particles at a temperature rise of 2 ℃/min, the storage modulus G' becomes less than 1×10 ⁵ The loss tangent tan delta at the temperature of Pa is 0.8 to 1.6.

＜11＞

The toner for developing an electrostatic charge image according to any one of < 1 > - < 10 >, wherein,

in the dynamic viscoelasticity measurement at a temperature rise of 2 ℃/min, the temperature is in the range of 90 ℃ to 150 DEG CThe storage modulus of the resin particles is G ' (p 90-150), the storage modulus of the toner particles is G ' (t 90-150), and the storage modulus of the components from which the resin particles are removed from the toner particles is G ' (r 90-150), 1×10 ⁴ Pa≤G’(p90-150)≤1×10 ⁶ Pa, and 1.0.ltoreq.logG '(t 90-150) -logG' (r 90-150). Ltoreq.4.0.

＜12＞

The toner for developing an electrostatic charge image according to any one of < 1 > - < 11 >, wherein,

in the dynamic viscoelasticity measurement of the toner for developing electrostatic charge image at a temperature rise of 2 ℃/min, the storage modulus G' is 1×10 in a range of 30 ℃ to 50 ℃ inclusive ⁸ Pa or more, and a storage modulus G' of less than 1×10 ⁵ Pa is 65 ℃ to 90 ℃.

＜13＞

The toner for developing an electrostatic charge image according to any one of < 1 > - < 12 >, wherein,

the binder resin contains a crystalline resin and,

the content of the crystalline resin is 4 mass% or more and 50 mass% or less relative to the entire binder resin.

＜14＞

The toner for developing an electrostatic charge image according to any one of < 1 > - < 13 >, wherein,

the binder resin contains a polyester resin.

＜15＞

The toner for developing an electrostatic charge image according to < 14 >, wherein,

the binder resin contains an amorphous polyester resin having an aliphatic dicarboxylic acid unit and a crystalline polyester resin having an aliphatic dicarboxylic acid unit.

＜16＞

The toner for developing an electrostatic charge image according to any one of < 1 > - < 15 >, wherein,

The resin particles have a difunctional alkyl acrylate as a structural unit, wherein the number of carbon atoms of an alkylene chain in the difunctional alkyl acrylate is 6 or more.

＜17＞

An electrostatic charge image developer comprising the toner for electrostatic charge image development described in any one of < 1 > - < 16 >.

＜18＞

A toner cartridge containing the toner for developing an electrostatic charge image of any one of < 1 > - < 16 >,

the toner cartridge is attached to and detached from the image forming apparatus.

＜19＞

A process cartridge comprising a developing unit which accommodates an electrostatic charge image developer described as < 17 > and develops an electrostatic charge image formed on a surface of an image holder into a toner image by using the electrostatic charge image developer,

the process cartridge is attached to and detached from the image forming apparatus.

＜20＞

An image forming apparatus includes:

an image holding body;

a charging unit that charges a surface of the image holding body;

a static charge image forming unit that forms a static charge image on a surface of the charged image holder;

a developing unit that accommodates the electrostatic charge image developer described as < 17 > and develops an electrostatic charge image formed on a surface of the image holder into a toner image with the electrostatic charge image developer;

A transfer unit that transfers the toner image formed on the surface of the image holder to the surface of a recording medium; and

and a fixing unit fixing the toner image transferred to the surface of the recording medium.

＜21＞

An image forming method, comprising:

a charging step of charging the surface of the image holder;

a static charge image forming step of forming a static charge image on the surface of the charged image holder;

a developing step of developing an electrostatic charge image formed on a surface of the image holder into a toner image using the electrostatic charge image developer described as < 17 >;

a transfer step of transferring the toner image formed on the surface of the image holder onto the surface of a recording medium; and

and a fixing step of fixing the toner image transferred to the surface of the recording medium.

Effects of the invention

According to < 1 >, there is provided a toner for developing an electrostatic charge image, which can obtain good fixability and has a small difference in glossiness between a fixed image under low-temperature and low-pressure conditions and a fixed image under high-temperature and high-pressure conditions, as compared with the case where any one of D1 (90), D50 (90), D1 (150) and D50 (150) is less than 0.5 or more, the value of D50 (150) -D1 (150) is 1.5 or more, or the case where the toner particles contain no resin particles, or the case where the number average molecular weight of a tetrahydrofuran-soluble component in the toner particles is less than 5000 or more 15000.

According to < 2 >, there is provided a toner for developing an electrostatic charge image which can obtain good fixability and has a small difference in glossiness between a fixed image under low-temperature and low-pressure conditions and a fixed image under high-temperature and high-pressure conditions, as compared with the case where the glass transition temperature Tg of the resin particles, which is determined from dynamic viscoelasticity measurement, is less than 10 ℃ or exceeds 45 ℃.

According to < 3 >, there is provided a toner for developing an electrostatic charge image, which has a smaller difference in glossiness between a fixed image under low-temperature and low-pressure conditions and a fixed image under high-temperature and high-pressure conditions than in the case where the loss tangent tan delta of resin particles at 150 ℃ exceeds 2.5.

According to < 4 >, there is provided a toner for developing an electrostatic charge image, which has a smaller difference in glossiness between a fixed image under low-temperature and low-pressure conditions and a fixed image under high-temperature and high-pressure conditions than in the case where the number average particle diameter of the resin particles exceeds 300 nm.

According to < 5 >, there is provided a toner for developing an electrostatic charge image, which has a smaller difference in glossiness between a fixed image under low-temperature and low-pressure conditions and a fixed image under high-temperature and high-pressure conditions than in the case where the content of resin particles is less than 2 mass%.

According to < 6 >, there is provided a toner for developing an electrostatic charge image, which has a smaller difference in glossiness between a fixed image under low-temperature and low-pressure conditions and a fixed image under high-temperature and high-pressure conditions than in the case where the resin particles are non-crosslinked resin particles.

According to < 7 >, there is provided a toner for developing an electrostatic charge image, which has a smaller difference in glossiness between a fixed image under low-temperature and low-pressure conditions and a fixed image under high-temperature and high-pressure conditions than in the case where the resin particles are polyester resin particles.

According to < 8 >, there is provided a toner for developing an electrostatic charge image, which has a smaller difference in glossiness between a fixed image under low-temperature and low-pressure conditions and a fixed image under high-temperature and high-pressure conditions than in the case where the difference (SP value (S) -SP value (R)) is smaller than-0.32.

According to < 9 >, there is provided a toner for developing an electrostatic charge image, having a storage modulus G' of less than 1X 10 with components from which resin particles are removed from toner particles ⁵ The fixing property is good when the temperature at Pa exceeds 90 ℃.

According to < 10 >, there is provided a toner for developing an electrostatic charge image, having a storage modulus G' of less than 1X 10 with components from which resin particles are removed from toner particles ⁵ The difference in glossiness between the fixed image under low temperature and low pressure conditions and the fixed image under high temperature and high pressure conditions is small compared to the case where the loss tangent tan δ at the temperature Pa exceeds 1.6.

According to < 11 >, there is provided a toner for developing an electrostatic charge image, and G' (p 90-150) is less than 1X 10 ⁴ Pa or more than 1X 10 ⁶ In the case of Pa, or in the case where log '(t 90-150) -log' (r 90-150) is smaller than 1.0 or exceeds 4.0, the difference in glossiness between the fixed image under low temperature and low pressure conditions and the fixed image under high temperature and high pressure conditions is small.

According to < 12 >, there is provided a toner for developing an electrostatic charge image, having a storage modulus G' of less than 1X 10 with the toner for developing an electrostatic charge image ⁵ The fixing property is good when the temperature at Pa exceeds 90 ℃.

According to < 13 >, there is provided a toner for developing an electrostatic charge image, which has a smaller difference in glossiness between a fixed image under low-temperature and low-pressure conditions and a fixed image under high-temperature and high-pressure conditions than in the case where the content of a crystalline resin exceeds 50 mass%.

According to < 14 >, there is provided a toner for developing an electrostatic charge image which is excellent in fixability as compared with the case where the binder resin is composed of a styrene acrylic resin.

According to < 15 >, there is provided a toner for developing an electrostatic charge image, which has a smaller difference in glossiness between a fixed image under low-temperature and low-pressure conditions and a fixed image under high-temperature and high-pressure conditions than in the case where the binder resin does not contain an amorphous polyester resin having an aliphatic dicarboxylic acid unit or a crystalline polyester resin having an aliphatic dicarboxylic acid unit.

According to < 16 >, there is provided a toner for developing an electrostatic charge image, which has a smaller difference in glossiness between a fixed image under low-temperature and low-pressure conditions and a fixed image under high-temperature and high-pressure conditions than in the case where a difunctional alkyl acrylate is not used as a structural unit or in the case where a difunctional alkyl acrylate is used as a structural unit and the number of carbon atoms of an alkylene chain in the difunctional alkyl acrylate is 5 or less.

According to < 17 >, < 18 >, < 19 >, < 20 >, or < 21 >, there is provided an electrostatic charge image developer, a toner cartridge, a process cartridge, an image forming apparatus, or an image forming method, which can obtain good fixability and a difference in gloss between a fixed image at a low temperature and a low pressure and a fixed image at a high temperature and a high pressure, as compared with the case where an electrostatic charge image developing toner having any one of D1 (90), D50 (90), D1 (150), and D50 (150) of less than 0.5 or more than 2.5, a value of D50 (150) -D1 (150), or a value of D50 (90) -D1 (90) of 1.0 or more, the case where an electrostatic charge image developing toner having toner particles containing no resin particles is applied, or the case where an image developing toner having a number average molecular weight of tetrahydrofuran soluble component in toner particles of less than 5000 or more than 15000 is applied.

Drawings

Fig. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present embodiment.

Fig. 2 is a schematic configuration diagram showing an example of a process cartridge to be attached to and detached from the image forming apparatus according to the present embodiment.

Detailed Description

Hereinafter, an embodiment of the present invention will be described. The description and examples are illustrative of the embodiments and are not intended to limit the scope of the invention.

In the numerical ranges described in stages in the present specification, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of the numerical range described in other stages. In the numerical ranges described in the present specification, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the embodiment.

In the present specification, (meth) acrylic means both acrylic and methacrylic.

In the present specification, the term "process" includes not only an independent process but also a process which cannot be clearly distinguished from other processes, as long as the intended purpose of the process can be achieved.

Each component may also contain a plurality of corresponding substances.

When referring to the amounts of the ingredients in the composition, the presence in the composition of a plurality of substances corresponding to the ingredients, unless otherwise indicated, means the total amount of the plurality of substances present in the composition.

[ toner for developing Electrostatic Charge image ]

In the static charge image developing toner according to the present embodiment (hereinafter, also referred to as "toner") is a static charge image developing toner including toner particles containing a binder resin, in the dynamic viscoelasticity measurement of the static charge image developing toner, the loss tangent tan δ at 90 ℃ and 1% by strain is D1 (90), the loss tangent tan δ at 90 ℃ and 50% by strain is D50 (90), the loss tangent tan δ at 150 ℃ and 1% by strain is D1 (150), the loss tangent tan δ at 150 ℃ and 50% by strain is D50 (150), the loss tangent tan δ at 150 ℃ and 50% by strain is D1 (90), D1 (150), and D50 (150) are respectively 0.5 to 2.5, the values of D50 (150) -D1 (150) are smaller than 1.5, the values of D50 (90) -D1 (90) are smaller than 1.0, and the molecular weight of the toner particles in the toner further contains the toner particles is 15000 or less than the molecular weight of tetrahydrofuran.

Hereinafter, the tetrahydrofuran-soluble component is also referred to as "THF-soluble component". The following toners are also referred to as "specific toners": d1 (90), D50 (90), D1 (150) and D50 (150) are respectively 0.5 to 2.5, D50 (150) -D1 (150) is less than 1.5, D50 (90) -D1 (90) is less than 1.0, the toner particles also have resin particles, and the number average molecular weight of THF-soluble components in the toner particles is also 5000 to 15000.

With the toner according to the present embodiment, with the above-described configuration, good fixability can be obtained, and the difference in glossiness between the fixed image under low-temperature and low-pressure conditions and the fixed image under high-temperature and high-pressure conditions is reduced. The reason is presumed to be as follows. Hereinafter, the difference in glossiness between the fixed image under low temperature and low pressure conditions and the fixed image under high temperature and high pressure conditions is also referred to as "difference in glossiness condition".

As described above, in order to obtain good fixability, it is considered to use an electrostatic charge image developing toner containing toner particles that are easily melted by heating. On the other hand, if image formation is performed using toner containing toner particles that are easily melted by heating, there is a tendency that the difference in glossiness condition becomes large. This is presumably because the deformation amount of the toner particles at the high temperature and the high strain amount is larger than the deformation amount of the toner particles at the low temperature and the low strain amount.

The amount of strain in the dynamic viscoelasticity measurement of 1% means that a displacement of 1% is applied to the height (i.e., gap) of the test specimen. That is, the strain amount of 1% is applied with a small displacement, corresponding to the case where the fixer pressure is low in the fixing process of the toner. On the other hand, the strain amount of 50% corresponds to a case where the fixer pressure is high in the fixing process of the toner. The temperature of 90 ℃ and the strain amount of 1% correspond to the fixing condition at low temperature and low pressure, the temperature of 150 ℃ and the strain amount of 50% correspond to the fixing condition at high temperature and high pressure, and each loss tangent tan δ corresponds to the toner deformation amount at each fixing condition. It is estimated that by controlling the difference between the loss tangent tan δ at the strain amount of 1% and the loss tangent tan δ at the strain amount of 50% to be within a certain range, the deformation amount of the toner can be suppressed to a certain range and the difference in glossiness can be suppressed even when the fixer pressure is changed.

The toner of the present embodiment is the above specific toner. That is, D1 (90), D50 (90), D1 (150) and D50 (150) are each 0.5 to 2.5, the values of D50 (150) -D1 (150) are less than 1.5, the values of D50 (90) -D1 (90) are less than 1.0, the toner particles further contain resin particles, and the THF-soluble component in the toner particles has a number average molecular weight of 5000 to 15000. In the above specific toner, the change in loss tangent with respect to the change in strain amount is small at any of the temperatures of 90 ℃ and 150 ℃. Therefore, it is presumed that since the toner has similar viscoelasticity at a high temperature high strain amount and a low temperature low strain amount, even if an image is fixed under a high temperature and high pressure condition, a fixed image having a small difference in glossiness from the fixed image under a low temperature low pressure condition can be obtained.

In this embodiment, since D1 (90), D50 (90), D1 (150) and D50 (150) are all 0.5 or more, they are easily melted by heating at the time of fixing, and good fixability can be obtained, as compared with the case where they are all less than 0.5.

Further, it is presumed that since the toner particles contain resin particles, the deformation amount of the toner fixed image with respect to the fixing pressure can be suppressed, and a fixed image with a small difference in glossiness can be obtained.

Further, since the THF soluble component in the toner particles has a number average molecular weight of 5000 or more and 15000 or less, the change in loss tangent with respect to the change in strain amount is small, and even in the case of a high-viscoelasticity toner in which the deformation amount is suppressed, high fixability can be obtained. Specifically, since the THF soluble component has a number average molecular weight in the above range, it is possible to suppress the deformation amount of the toner particles from becoming large and the gloss difference from becoming large under high-temperature and high-pressure fixing conditions due to the presence of a large amount of low molecular weight components in the toner particles, as compared with the case where the number average molecular weight is too small. Since the THF soluble component has a number average molecular weight in the above range, the deformation amount of the toner particles is suppressed due to the presence of a large amount of high molecular weight component in the toner particles, and on the other hand, low-temperature fixability is suppressed from being easily obtained, as compared with the case where the number average molecular weight is excessively large. It is further preferable that the number average molecular weight of the THF-soluble component is 7000 or more and 10000 or less.

As described above, in the present embodiment, it is presumed that good fixability can be obtained, and the difference in glossiness between the fixed image under low-temperature and low-pressure conditions and the fixed image under high-temperature and high-pressure conditions is reduced.

The loss tangent of the toner was determined as follows.

Specifically, a measurement sample was prepared by molding a toner to be measured into a tablet at room temperature (25 ℃) using a press molding machine. Then, using the measurement sample, dynamic viscoelasticity was measured by a rheometer under the following conditions, and loss tangent tan δ at 90 ℃ or 150 ℃ and strain amount of 1% or 50% was obtained from each curve of the obtained storage modulus and loss modulus, to obtain D1 (90), D50 (90), D1 (150) and D50 (150).

Assay conditions-

Measurement device: rheometer ARES-G2 (TA Instruments Co., ltd.)

And (3) measuring a clamp: 8mm parallel plate

Gap: adjusted to 3mm

Frequency: 1Hz

Regarding the number average molecular weight of the THF-soluble component in the above toner particles, the THF-soluble component of the toner particles was prepared using two "HLC-8120GPC, SC-8020 (6.0 mmID. Times.15 cm manufactured by Tosoh Co., ltd.), and Tetrahydrofuran (THF) as an eluent.

Specifically, 0.5mg of toner particles to be measured was dissolved in 1g of THF, and then subjected to ultrasonic dispersion, and the concentration was adjusted so as to be 0.5 mass%.

The measurement was performed using an RI detector under conditions of a sample concentration of 0.5 mass%, a flow rate of 0.6ml/min, a sample injection amount of 10. Mu.l, and a measurement temperature of 40 ℃.

Calibration curves were prepared according to "Polystyrene Standard sample TSK Standard", from Tosoh Corp: 10 samples "A-500", "F-1", "F-10", "F-80", "F-380", "A-2500", "F-4", "F-40", "F-128", "F-700" were prepared.

When toner particles are obtained from an externally added toner, for example, the toner is dispersed to 10 mass% in a 0.2 mass% aqueous solution of polyethylene oxide (10) octylphenyl ether, and ultrasonic vibration (frequency 20kHz, output 30W) is applied for 60 minutes while maintaining a temperature of 30 ℃ or less, whereby the external additive is released. The toner particles are filtered and washed from the obtained dispersion liquid, whereby toner particles from which the external additive is removed are obtained.

The method for obtaining the specific toner is not particularly limited.

As a method for obtaining a specific toner, for example, the following methods are mentioned: in the dynamic viscoelasticity measurement at a temperature rise of 2 ℃/min, the storage modulus G' in the range of 90 ℃ to 150 ℃ inclusive is 1×10, wherein both the region near the surface of the toner particles and the region near the center of the toner particles are uniformly contained ⁴ Pa or more and 1×10 ⁶ Pa or less.

The storage modulus G' in the range of 90 ℃ to 150 ℃ is 1×10 ⁴ Pa or more and 1×10 ⁶ The resin particles Pa or below are referred to as "specific resin particles".

The reason why the specific toner is easily obtained by uniformly dispersing the specific resin particles in both the region near the surface of the toner particles and the region near the center of the toner particles cannot be determined, but is presumed as follows.

As described above, specific resin particlesIs that the storage modulus G' is 1X 10 even if the temperature is raised to 150 DEG C ⁴ Particles of Pa or more. That is, the specific resin particles are particles having a high elastic modulus at a high temperature. Therefore, it is assumed that the specific resin particles are contained in the toner particles, so that the loss tangent of the toner as a whole is not easily increased at high temperature and high strain, and the difference between the loss tangent of the toner as a whole at low temperature and low strain is reduced.

In particular, it is presumed that by uniformly dispersing the specific resin particles in both the region near the surface of the toner particles and the region near the center of the toner particles, the loss tangent of the toner is reduced at both the low-temperature low-strain amount and the high-temperature high-strain amount, and the difference thereof is also reduced, so that the specific toner is easily obtained.

In order to encapsulate the specific resin particles in the toner particles, the specific resin particles preferably have a high affinity with the binder resin. Specific examples of the method for improving the affinity include a method for controlling the SP value and a method for using a surfactant as a dispersant for specific resin particles. However, when specific resin particles having high affinity with the binder resin are used, the specific resin particles are formed of an organic polymer unlike inorganic fillers, carbon black, metal particles, and the like, and therefore are likely to be compatible with the binder resin, and the dispersibility may be lowered.

On the other hand, when specific resin particles having low affinity for the binder resin are used, the particles are difficult to be encapsulated in the toner particles and sometimes discharged to the surface of the toner particles or the outside of the toner particles.

By using specific resin particles having an intermediate affinity between specific resin particles having a high affinity for a binder resin and specific resin particles having a low affinity for a binder resin, specific resin particles can be contained to some extent in toner particles, but there is a case where the specific resin particles are biased to exist while maintaining a state of constant contact because of the same material when they are in contact with each other, irrespective of a toner manufacturing method such as an emulsion aggregation method or a kneading pulverization method, and it is difficult to uniformly arrange the specific resin particles in the toner particles. As for the reason for maintaining the state in which the specific resin particles are kept in contact with each other at all times, it is considered that entanglement of polymer chains constituting the polymer components of the specific resin particles is one of the reasons for contact.

Thus, by using the crosslinked resin particles as the specific resin particles, entanglement of the polymer chains can be suppressed, and the polymer chains are not easily brought into contact with each other at all times, and can be uniformly arranged in the toner particles.

The storage modulus G' and the loss tangent tan δ and the glass transition temperature Tg of the resin particles are obtained as follows.

Specifically, a disc-shaped sample having a thickness of 2mm and a diameter of 8mm was produced by applying pressure to the resin particles to be measured, and this was used as a measurement sample. In measuring the resin particles contained in the toner particles, the resin particles are taken out from the toner particles, and a measurement sample is prepared. Examples of the method for removing the resin particles from the toner particles include the following methods: the toner particles are immersed in a solvent in which the binder resin is dissolved and the resin particles are not dissolved, and the binder resin is dissolved in the solvent, whereby the resin particles are taken out.

Then, the obtained measurement sample, that is, a disk-shaped sample, was sandwiched between parallel plates having a diameter of 8mm, and the measurement temperature was raised from 10℃to 150℃at 2℃per minute at a strain of 0.1 to 100%, whereby dynamic viscoelasticity was measured under the following conditions. From the respective curves of the storage modulus and loss modulus obtained by the measurement, the storage modulus G' and the loss tangent tan δ were obtained. The peak temperature of the loss tangent tan delta is set to the glass transition temperature Tg.

Assay conditions-

Measurement device: rheometer ARES-G2 (TA Instruments Co., ltd.)

Gap: adjusted to 3mm

Frequency: 1Hz

The details of the toner according to the present embodiment will be described below.

The toner according to the present embodiment includes toner particles and an external additive as needed.

(toner particles)

The toner particles contain at least a binder resin and may contain other components as necessary.

As described above, from the viewpoint of obtaining a specific toner, it is preferable that the toner particles further contain specific resin particles.

Hereinafter, as an example of toner particles contained in the specific toner, toner particles containing a binder resin and specific resin particles will be described.

The toner particles are composed of, for example, a binder resin, specific resin particles, a colorant, a release agent, and other additives as needed.

Binding resin-

Examples of the binder resin include vinyl resins composed of homopolymers of monomers such as styrenes (e.g., styrene, p-chlorostyrene, α -methylstyrene, etc.), (meth) acrylates (e.g., methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc.), ethylenically unsaturated nitriles (e.g., acrylonitrile, methacrylonitrile, etc.), vinyl ethers (e.g., vinyl methyl ether, vinyl isobutyl ether, etc.), vinyl ketones (e.g., vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc.), olefins (e.g., ethylene, propylene, butadiene, etc.), or copolymers obtained by combining two or more of these monomers.

As the binder resin, for example, there may be mentioned: and non-vinyl resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and modified rosins, mixtures thereof with the vinyl resins, and graft polymers obtained by polymerizing vinyl monomers in the presence of the vinyl resins.

These binder resins may be used singly or in combination of two or more.

The binder resin preferably contains a polyester resin.

When styrene (meth) acrylic resin particles are used as the specific resin particles, the difference (SP value (S) -SP value (R)) between the solubility parameter SP value (S) of the specific resin particles and the solubility parameter SP value (R) of the binder resin, which will be described later, is easily within a preferable numerical range by containing the polyester resin as the binder resin. As a result, the specific resin particles are easily dispersed in the toner particles, and as a result, the difference in gloss conditions is reduced.

When the difference (SP value (S) -SP value (R)) is within the above range, the affinity of the binder resin to the specific resin particles is higher than that in the case of excessively small, and therefore, the dissolution of a part of the binder resin and the decrease in dispersibility can be suppressed. When the difference (SP value (S) -SP value (R)) is within the above range, the affinity between the binder resin and the specific resin particles is lower than that in the case of an excessive amount, and therefore, the specific resin particles are prevented from being discharged to the surface of the toner particles or from the outside of the toner particles without being contained in the toner particles.

The binder resin preferably contains a crystalline resin and an amorphous resin.

The crystalline resin is a resin having a distinct endothermic peak, not having a stepwise change in endothermic heat in Differential Scanning Calorimetry (DSC).

On the other hand, an amorphous resin refers to a resin that does not have a clear endothermic peak but has only a stepwise endothermic change in a thermal analysis measurement using Differential Scanning Calorimetry (DSC), and refers to a resin that is solid at normal temperature and is thermally plasticized at a temperature equal to or higher than the glass transition temperature.

Specifically, for example, a crystalline resin means that the half-peak width of an endothermic peak is within 10 ℃ when measured at a temperature rising rate of 10 ℃/min, and an amorphous resin means that the half-peak width exceeds 10 ℃ or that no definite endothermic peak is observed.

The crystalline resin will be described.

The crystalline resin may be: crystalline polyester resins, crystalline vinyl resins (e.g., polyalkylene resins, long-chain alkyl (meth) acrylate resins, etc.), and the like. Among them, crystalline polyester resins are preferable from the viewpoints of mechanical strength and low-temperature fixability of the toner.

Crystalline polyester resin

Examples of the crystalline polyester resin include polycondensates of polycarboxylic acids and polyols. As the crystalline polyester resin, a commercially available product or a synthetic resin can be used.

In order to easily form a crystalline structure, the crystalline polyester resin preferably uses a polycondensate of a polymerizable monomer having a linear aliphatic group as compared with a polymerizable monomer having an aromatic group.

Examples of the polycarboxylic acid include: aliphatic dicarboxylic acids (for example, oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1, 9-nonanedicarboxylic acid, 1, 10-decanedicarboxylic acid, 1, 12-dodecanedicarboxylic acid, 1, 14-tetradecanedicarboxylic acid, 1, 18-octadecanedicarboxylic acid, etc.), aromatic dicarboxylic acids (for example, dibasic acids such as phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2, 6-dicarboxylic acid, etc.), anhydrides thereof, or lower (for example, 1 to 5 carbon atoms) alkyl esters thereof.

The polycarboxylic acid may be used in combination with a dicarboxylic acid as a trivalent or more carboxylic acid having a crosslinked structure or a branched structure. Examples of the trivalent carboxylic acid include: aromatic carboxylic acids (e.g., 1,2, 3-benzenetricarboxylic acid, 1,2, 4-naphthalenetricarboxylic acid, etc.), anhydrides thereof, or lower (e.g., 1 to 5 carbon atoms) alkyl esters thereof.

As the polycarboxylic acid, a dicarboxylic acid having a sulfonic acid group or a dicarboxylic acid having an olefinic double bond may be used in combination with these dicarboxylic acids.

The polycarboxylic acid may be used singly or in combination of two or more.

Examples of the polyol include: aliphatic diols (for example, linear aliphatic diols having 7 to 20 carbon atoms in the main chain). Examples of the aliphatic diol include: ethylene glycol, 1, 3-propanediol, 1, 4-butanediol, 1, 5-pentanediol, 1, 6-hexanediol, 1, 7-heptanediol, 1, 8-octanediol, 1, 9-nonanediol, 1, 10-decanediol, 1, 11-undecanediol, 1, 12-dodecanediol, 1, 13-tridecanediol, 1, 14-tetradecanediol, 1, 18-octadecanediol, 1, 14-eicosanediol, and the like. Among them, preferred aliphatic diols are 1, 8-octanediol, 1, 9-nonanediol, and 1, 10-decanediol.

The polyhydric alcohol may be a trivalent or higher alcohol having a crosslinked structure or a branched structure. Examples of the trivalent or higher alcohol include glycerol, trimethylolethane, trimethylolpropane, pentaerythritol, and the like.

The polyhydric alcohol may be used singly or in combination of two or more.

The content of the aliphatic diol may be 80 mol%, and preferably 90 mol% or more.

The melting temperature of the crystalline polyester resin is preferably 50 ℃ or more and 100 ℃ or less, more preferably 55 ℃ or more and 90 ℃ or less, and still more preferably 60 ℃ or more and 85 ℃ or less.

The melting temperature was determined from a Differential Scanning Calorimeter (DSC) curve obtained by using the "melting peak temperature" described in the method for determining melting temperature of JIS K7121-1987 "method for measuring transition temperature of plastics".

The weight average molecular weight (Mw) of the crystalline polyester resin is preferably 6,000 to 35,000.

The crystalline polyester resin is obtained by a known production method, for example, in the same manner as the amorphous polyester.

When the toner particles contain the crystalline resin, the content of the crystalline resin to the entire binder resin is preferably 4% by mass or more and 50% by mass or less, more preferably 6% by mass or more and 30% by mass or less, and still more preferably 8% by mass or more and 20% by mass or less.

When the content of the crystalline resin is in the above range, good fixability can be easily obtained as compared with the case where the content is smaller than the above range. When the content of the crystalline resin is within the above range, an excessive increase in glossiness of the fixed image fixed under high temperature and high pressure conditions due to an excessive amount of the crystalline resin having relatively low elasticity can be suppressed as compared with a case where the content is greater than the above range. Thus, the difference in gloss conditions is reduced.

Amorphous resins are described.

Examples of the amorphous resin include: known amorphous resins such as amorphous polyester resins, amorphous vinyl resins (e.g., styrene acrylic resins, etc.), epoxy resins, polycarbonate resins, and polyurethane resins. Among them, amorphous polyester resins and amorphous vinyl resins (particularly styrene acrylic resins) are preferable, and amorphous polyester resins are more preferable.

Amorphous polyester resin

Examples of the amorphous polyester resin include polycondensates of polycarboxylic acids and polyols. As the amorphous polyester resin, commercially available ones may be used, or synthetic resins may be used.

Examples of the polycarboxylic acid include: aliphatic dicarboxylic acids (e.g., oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, alkenylsuccinic acid, adipic acid, sebacic acid, etc.), alicyclic dicarboxylic acids (e.g., cyclohexanedicarboxylic acid, etc.), aromatic dicarboxylic acids (e.g., terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc.), anhydrides thereof, or lower (e.g., 1 to 5 carbon atoms) alkyl esters thereof. Among them, for example, aromatic dicarboxylic acids are preferable as the polycarboxylic acid.

The polycarboxylic acid may be used in combination with a dicarboxylic acid as a trivalent or more carboxylic acid having a crosslinked structure or a branched structure. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, anhydrides thereof, and lower (for example, 1 to 5 carbon atoms) alkyl esters thereof.

The polycarboxylic acid may be used singly or in combination of two or more.

Examples of the polyol include: aliphatic diols (e.g., ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butylene glycol, hexylene glycol, neopentyl glycol, etc.), alicyclic diols (e.g., cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A, etc.), aromatic diols (e.g., ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, etc.). Among them, for example, aromatic diols and alicyclic diols are preferable, and aromatic diols are more preferable.

As the polyol, a trivalent or more polyol having a crosslinked structure or a branched structure may be used in combination with a diol. Examples of the trivalent or higher polyhydric alcohol include glycerol, trimethylolpropane and pentaerythritol.

The polyhydric alcohol may be used alone or in combination of two or more.

The glass transition temperature (Tg) of the amorphous polyester resin is preferably 50 ℃ or higher and 80 ℃ or lower, more preferably 50 ℃ or higher and 65 ℃ or lower.

The glass transition temperature is obtained from a Differential Scanning Calorimeter (DSC) curve obtained by DSC, more specifically, from an "extrapolated glass transition onset temperature" described in "method for measuring a transition temperature of plastics" in JIS K7121-1987.

The weight average molecular weight (Mw) of the amorphous polyester resin is preferably 5000 to 1000000, more preferably 7000 to 500000.

The number average molecular weight (Mn) of the amorphous polyester resin is preferably 2000 to 100000.

The molecular weight distribution Mw/Mn of the amorphous polyester resin is preferably 1.5 or more and 100 or less, more preferably 2 or more and 60 or less.

The weight average molecular weight and the number average molecular weight were measured by Gel Permeation Chromatography (GPC). GPC-based molecular weight measurement was performed in a THF solvent using GPC HLC-8120GPC manufactured by Tosoh as a measurement device and TSKgel SuperHM-M (15 cm) manufactured by Tosoh. The weight average molecular weight and the number average molecular weight were calculated using a molecular weight calibration curve prepared from the measurement result using a monodisperse polystyrene standard sample.

The amorphous polyester resin is obtained by a known production method. Specifically, for example, the polymerization temperature is set to 180 ℃ or higher and 230 ℃ or lower, the pressure in the reaction system is reduced as needed, and water or alcohol generated during the condensation is removed and reacted.

When the monomers of the starting materials are insoluble or incompatible at the reaction temperature, a high boiling point solvent may also be added as a cosolvent to dissolve them. In this case, the polycondensation reaction is performed while removing the cosolvent by distillation. When a monomer having poor compatibility is present, the monomer having poor compatibility may be condensed in advance with an acid or alcohol to be polycondensed with the monomer, followed by polycondensation with the main component.

The binder resin preferably contains a polyester resin having an aliphatic dicarboxylic acid unit (i.e., a structural unit derived from an aliphatic dicarboxylic acid). When the polyester resin as the binder resin has an aliphatic dicarboxylic acid unit, the binder resin has higher flexibility than when the polyester resin has only an aromatic dicarboxylic acid unit, and thus the specific resin particles can be dispersed in a more nearly uniform state, and the range of change in the loss tangent tan δ can be further reduced.

The binder resin preferably contains an amorphous polyester resin having an aliphatic dicarboxylic acid unit and a crystalline polyester resin having an aliphatic dicarboxylic acid unit. In the case where the binder resin contains an amorphous polyester resin and a crystalline polyester resin, since both have aliphatic dicarboxylic acid units, specific resin particles can be more uniformly dispersed.

As aliphatic dicarboxylic acids, for example, those of the general formula "HOOC- (CH) ₂ ) _n -COOH "represents a saturated aliphatic dicarboxylic acid. N in the above formula is preferably 4 to 20, more preferably 4 to 12.

The content of the binder resin is, for example, preferably 40% by mass or more and 95% by mass or less, more preferably 50% by mass or more and 90% by mass or less, and still more preferably 60% by mass or more and 85% by mass or less, relative to the entire toner particles.

When the content of the specific resin particles is 1, the ratio of the content of the crystalline resin to the content of the specific resin particles is preferably 0.2 or more and 10 or less, more preferably 1 or more and 5 or less.

Since the ratio of the content of the crystalline resin to the content of the specific resin particles is in the above range, the toner can be suppressed from being reduced in the melting property due to the fact that the low viscosity component of the toner is excessively small at 90 ℃ or more and 150 ℃ or less and the action of the specific resin particles as the high elastic component is increased, and the fixing property is improved, as compared with the case of less than 0.2.

Since the ratio of the content of the crystalline resin to the content of the specific resin particles is in the above range, it is possible to suppress the decrease in the excessive amount of the components and the increase in the deformation amount of the toner due to heat and pressure generated by the fixer, as compared with the case of exceeding 10, and the decrease in the gloss difference due to the fixing condition can be suppressed.

When the content of the specific resin particles is 1, the ratio of the content of the amorphous resin to the content of the specific resin particles is preferably 1.3 to 45, more preferably 3 to 15.

Specific resin particles-

The specific resin particles have a storage modulus G' of 1X 10 in the range of 90 ℃ to 150 ℃ in dynamic viscoelasticity measurement at a temperature rise of 2 ℃/min ⁴ Pa or more and 1×10 ⁶ The resin particles of Pa or less are not particularly limited.

The storage modulus G' of the specific resin particles in the range of 90 ℃ to 150 ℃ is preferably 1×10 ⁵ Pa or more and 8×10 ⁵ Pa or less, more preferably 1×10 ⁵ Pa or more and 6×10 ⁵ Pa or below.

By using the resin particles having the storage modulus G 'in the range of 90 ℃ to 150 ℃, excessive increase in glossiness of the fixed image fixed under high temperature and high pressure conditions can be suppressed as compared with the case of using the resin particles having a lower storage modulus G' than the range. Thus, the difference in gloss conditions is reduced. By using resin particles having a storage modulus G 'in the range of 90 ℃ to 150 ℃, it is possible to suppress the decrease in fixability due to the excessively high elasticity of the toner particles, and to easily obtain good fixability, as compared with the case of using resin particles having a higher storage modulus G' in the range.

The specific resin particles are preferably resin particles having a loss tangent tan delta in a range of 30 ℃ to 150 ℃ in dynamic viscoelasticity measurement at a temperature rise of 2 ℃/min of 0.01 to 2.5. The specific resin particles are more preferably resin particles having a loss tangent tan δ of 0.01 to 1.0, particularly preferably 0.01 to 0.5, in a range of 65 ℃ to 150 ℃.

Since the specific resin particles have a loss tangent tan δ in the range of 30 ℃ to 150 ℃, the toner particles are more likely to be deformed during fixing than in the case of being lower than the above range, and good fixability is more likely to be obtained. Further, since the loss tangent tan δ of the specific resin particles in the range of 65 ℃ or more and 150 ℃ or less, which is the temperature at which the toner particles are likely to be deformed further, is in the above range, an excessive increase in the glossiness of the fixed image fixed under high temperature and high pressure conditions can be suppressed as compared with the case where it is higher than the above range. Thus, the difference in gloss conditions is reduced.

The specific resin particles are preferably crosslinked resin particles.

The "crosslinked resin particles" refer to resin particles having a bridging structure between specific atoms in a polymer structure contained in the resin particles.

By setting the specific resin particles to be crosslinked resin particles, the storage modulus G' in the range of 90 ℃ to 150 ℃ is easily obtained, and the specific toner is easily obtained.

Examples of the crosslinked resin particles include crosslinked resin particles crosslinked by ionic bonds (ionic crosslinked resin particles) and crosslinked resin particles crosslinked by covalent bonds (covalent bond crosslinked resin particles). Among them, as the crosslinked resin particles, crosslinked resin particles crosslinked by covalent bonds are preferable.

Examples of the type of the resin used for the crosslinked resin particles include polyolefin-based resins (polyethylene, polypropylene, etc.), styrene-based resins (polystyrene, α -polymethylstyrene, etc.), (meth) acrylic resins (polymethyl methacrylate, polyacrylonitrile, etc.), epoxy resins, polyurethane resins, polyurea resins, polyamide resins, polycarbonate resins, polyether resins, polyester resins, and copolymer resins thereof. These resins may be used alone or in combination of two or more.

Among the resins mentioned above, styrene (meth) acrylic resins are preferable as the resin for crosslinking the resin particles.

That is, styrene (meth) acrylic resin particles are preferable as the crosslinked resin particles.

Since the crosslinked resin particles are styrene (meth) acrylic resin particles, the crosslinked resin particles easily have a storage modulus G' in the above range of 90 ℃ to 150 ℃ and thus a specific toner can be easily obtained.

Examples of the styrene (meth) acrylic resin include resins obtained by polymerizing the following styrene monomers and (meth) acrylic monomers by radical polymerization.

Examples of the styrene monomer include: alkyl-substituted styrenes having an alkyl chain such as styrene, α -methylstyrene, vinylnaphthalene, or 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-ethylstyrene, 3-ethylstyrene, 4-ethylstyrene, etc., halogenated styrenes such as 2-chlorostyrene, 3-chlorostyrene, 4-chlorostyrene, etc., and fluorine-substituted styrenes such as 4-fluorostyrene, 2, 5-difluorostyrene, etc. Among them, styrene and α -methylstyrene are preferable.

Examples of the (meth) acrylic monomer include (meth) acrylic acid, n-methyl (meth) acrylate, n-ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, n-heptyl (meth) acrylate, n-octyl (meth) acrylate, n-decyl (meth) acrylate, n-dodecyl (meth) acrylate, n-lauryl (meth) acrylate, n-tetradecyl (meth) acrylate, n-hexadecyl (meth) acrylate, n-octadecyl (meth) acrylate, isopropyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, isopentyl (meth) acrylate, pentyl (meth) acrylate, neopentyl (meth) acrylate, isohexyl (meth) acrylate, isoheptyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethyl (meth) acrylate, phenyl (meth) acrylate, biphenyl (meth) acrylate, diphenyl (meth) acrylate, tert-butyl (meth) acrylate, cyclohexyl (meth) acrylate, and (meth) hexyl (meth) acrylate Dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, methoxyethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-carboxyethyl (meth) acrylate, acrylonitrile, (meth) acrylamide, and the like. Among them, n-butyl (meth) acrylate and 2-carboxyethyl (meth) acrylate are preferable.

In the crosslinked resin particles, examples of the crosslinking agent for crosslinking the resin include: aromatic polyvinyl compounds such as divinylbenzene and divinylnaphthalene; polyvinyl esters of aromatic polycarboxylic acids such as divinyl phthalate, divinyl isophthalate, divinyl terephthalate, divinyl homophthalate, divinyl trimesic acid, trivinyl trimesic acid, divinyl naphthalene dicarboxylate and divinyl biphenyl carboxylate; divinyl esters of nitrogen-containing aromatic compounds such as divinyl pyridine dicarboxylic acid esters; vinyl esters of unsaturated heterocyclic carboxylic acids such as vinyl Jiao Nian acid ester, vinyl furan carboxylic acid ester, vinyl pyrrole-2-carboxylic acid ester and vinyl thiophene carboxylic acid ester; (meth) acrylic esters of linear polyols such as butanediol diacrylate, butanediol dimethacrylate, hexanediol diacrylate, hexanediol dimethacrylate, octanediol diacrylate, octanediol dimethacrylate, nonanediol diacrylate, nonanediol dimethacrylate, decanediol diacrylate, decanediol dimethacrylate, dodecanediol diacrylate, dodecanediol dimethacrylate, and the like; branched (meth) acrylates of substituted polyols such as neopentyl glycol dimethacrylate, 2-hydroxy, 1, 3-bisacryloyloxypropane and the like; polyethylene glycol di (meth) acrylates, polypropylene polyethylene glycol di (meth) acrylates, divinyl succinate, divinyl fumarate, vinyl maleate, divinyl diglycolate, vinyl itaconate, divinyl acetonate, divinyl glutarate, divinyl 3,3' -thiodipropionate, divinyl trans-aconitate, trivinyl trans-aconitate, divinyl adipate, divinyl pimelate, divinyl suberate, divinyl azelate, divinyl sebacate, divinyl dodecanedioate, divinyl brazilate and other polyvinyl esters of polycarboxylic acids. The crosslinking agent may be used alone or in combination of two or more.

Among them, as a crosslinking agent for crosslinking the resin, a difunctional alkyl acrylate having an alkylene chain of 6 or more carbon atoms is preferably used. That is, the crosslinked resin particles have a difunctional alkyl acrylate as a structural unit, and the number of carbon atoms of the alkylene chain in the difunctional alkyl acrylate is preferably 6 or more.

By using crosslinked resin particles having a difunctional alkyl acrylate as a structural unit and an alkylene chain having 6 or more carbon atoms, a specific toner can be easily obtained. In a specific toner, the deformation amount of toner particles is suppressed to a certain range even under high-pressure fixing conditions, which is important for suppression of the gloss difference. When the difference between the elasticity of the specific resin particles and the elasticity of the binder resin as the crosslinked resin particles is too large, it may be difficult to obtain the effect of suppressing the change in the loss tangent tan δ by the specific resin particles. Therefore, it is preferable to control the elasticity of the specific resin particles so as not to be excessively high. When the crosslinking density of the specific resin particles is high (i.e., the distance between the crosslinking points is short), in the case where a difunctional acrylate having a long alkylene chain is used as the crosslinking agent for the case where the elasticity is too high, it is possible to suppress the case where the crosslinking density becomes low (i.e., the distance between the crosslinking points is long) and the elasticity of the specific resin particles becomes too high. As a result, the difference in glossiness can be further suppressed.

The number of carbon atoms of the alkylene chain in the difunctional alkyl acrylate is preferably 6 or more, more preferably 6 or more and 12 or less, and still more preferably 8 or more and 12 or less, from the viewpoint of adjusting the crosslink density to an appropriate range. More specific examples of the difunctional alkyl acrylate include 1, 6-hexanediol acrylate, 1, 6-hexanediol methacrylate, 1, 8-octanediol diacrylate, 1, 8-octanediol dimethacrylate, 1, 9-nonanediol diacrylate, 1, 9-nonanediol dimethacrylate, 1, 10-decanediol diacrylate, 1, 10-decanediol dimethacrylate, 1, 12-dodecanediol diacrylate and 1, 12-dodecanediol dimethacrylate, and among these, 1, 10-decanediol diacrylate and 1, 10-decanediol dimethacrylate are preferable.

In the case where the specific resin particles are polymers of a composition for forming specific resin particles containing a styrene-based monomer, (meth) acrylic-based monomer and a crosslinking agent, the viscoelasticity of the specific resin particles can be controlled by adjusting the amount of the crosslinking agent contained in the composition. For example, by increasing the amount of the crosslinking agent contained in the composition, resin particles having a high storage modulus G' can be easily obtained. The content of the crosslinking agent in the composition for forming specific resin particles is, for example, preferably 0.3 parts by mass or more and 5.0 parts by mass or less, more preferably 0.5 parts by mass or more and 2.5 parts by mass or less, and still more preferably 1.0 parts by mass or more and 2.0 parts by mass or less, relative to 100 parts by mass of the total of the styrene-based monomer, (meth) acrylic-based monomer and the crosslinking agent.

The glass transition temperature Tg of the specific resin particles, which is determined by dynamic viscoelasticity measurement, is preferably 10℃or higher and 45℃or lower. When the glass transition temperature Tg of the specific resin particles is 10 ℃ or more and 45 ℃ or less, the toner is more excellent in fixability and reduced in difference in glossiness between a fixed image under low-temperature and low-pressure conditions and a fixed image under high-temperature and high-pressure conditions.

Further, the glass transition temperature Tg of the specific resin particles is preferably 15 ℃ or higher and 40 ℃ or lower, more preferably 20 ℃ or higher and 35 ℃ or lower.

When the glass transition temperature Tg of the specific resin particles is in the above range, a large difference from the Tg of the binder resin and a tendency of the resin particles to deviate from each other in the toner particles can be suppressed as compared with a case where Tg is too low, a dispersion state of the specific resin particles which is nearly uniform can be easily maintained, a deformation suppressing effect against pressurization can be easily obtained at the time of fixing, and a difference in glossiness becomes small. When the glass transition temperature Tg of the specific resin particles is in the above range, deterioration of low-temperature fixability due to deterioration of the meltability of the binder resin can be suppressed as compared with the case where Tg is excessively high.

The number average particle diameter of the specific resin particles is preferably 60nm to 300nm, more preferably 100nm to 200nm, still more preferably 130nm to 170 nm.

Since the number average particle diameter of the specific resin particles is in the above range, the toner particles are suppressed from being easily affected by the high elasticity of the specific resin particles, and good fixability can be obtained, as compared with the case where the number average particle diameter is smaller than the above range. Since the number average particle diameter of the specific resin particles is in the above range, the specific resin particles are easily dispersed in the toner particles in a nearly uniform state, and thus the toner is easily formed to have a nearly viscoelastic property at a high temperature and a low strain, as compared with the case where the number average particle diameter is larger than the above range. Thus, the difference in gloss conditions is reduced.

The number average particle diameter of the specific resin particles is a value measured by a Transmission Electron Microscope (TEM).

As the transmission electron microscope, JEM-1010, manufactured by JEOL corporation, japan, for example, can be used.

Hereinafter, a method for measuring the number average particle diameter of the specific resin particles will be specifically described.

The toner particles were cut into a thickness of about 0.3 μm by a microtome. A photograph of 4500 times the cross section of the toner particles was taken by a transmission electron microscope, the equivalent circle diameter of 1000 resin particles dispersed in the toner particles was calculated from the cross-sectional areas of the resin particles, and the number average particle diameter was obtained by arithmetic averaging the values.

The number average particle diameter of the specific resin particles may be a value obtained by measuring the dispersion of the specific resin particles by a laser diffraction particle size distribution measuring apparatus (for example, LA-700 manufactured by horiba, ltd.).

It is preferable that the specific resin particles be uniformly contained in both a region near the surface of the toner particles (hereinafter, also referred to as "surface region") and a region near the center of the toner particles (hereinafter, also referred to as "center region"). By containing the specific resin particles in both the surface region and the central region, the difference in gloss condition is reduced as compared with the case where only one of the surface region and the central region contains the specific resin particles.

For example, when a specific resin particle is contained only in the surface region, the deformation amount of the toner particle is thought to be small under the low temperature and low pressure condition due to the viscoelastic effect of the surface region, whereas the deformation amount of the toner particle is thought to be large under the high temperature and high pressure condition due to the viscoelastic effect of the center region. Therefore, the difference in gloss conditions sometimes becomes large. When the specific resin particles are contained only in the central region, the deformation amount of the toner particles is small under low temperature and low pressure conditions, whereas the dispersion state of the specific resin particles in the fixed image is poor (biased to exist), whereas under high temperature and high pressure conditions, the deformation amount of the toner particles is large, and the dispersion state of the specific resin particles in the fixed image is easily good (nearly uniform state). When the dispersion state of the specific resin particles in the fixed image is poor, the portion where the specific resin particles are present is hardly deformed to become a convex portion, and the portion where the specific resin particles are not present is easily deformed to become a concave portion, so that the glossiness is lowered. When the dispersion state is good, the above state is suppressed, and the glossiness increases. Therefore, the difference in gloss conditions sometimes becomes large.

On the other hand, it is assumed that the difference in gloss condition is reduced in the case where both the surface region and the center region contain specific resin particles, unlike the case where only the surface region and only the center region are contained.

The content of the specific resin particles is preferably 2% by mass or more and 30% by mass or less, more preferably 5% by mass or more and 25% by mass or less, and still more preferably 8% by mass or more and 20% by mass or less, relative to the entire toner particles.

Since the content of the specific resin particles is in the above range, the toner tends to have near viscoelasticity at a high temperature and a low strain, and the difference in glossiness condition is reduced, as compared with the case where the content is smaller than the above range. Since the content of the specific resin particles is in the above range, the decrease in fixability due to the excessively high elasticity of the toner particles can be suppressed, and good fixability can be obtained, as compared with the case where the content is more than the above range.

Coloring agent-

Examples of the colorant include various pigments such as carbon black, chrome yellow, hansa yellow, benzidine yellow, vat yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, fu Ergan orange, mo Chi ocean (watch young) red, permanent red, brilliant carmine 3B, brilliant carmine 6B, dupont oil red, pyrazolone red, lithol red, rhodamine B lake, lake red C, pigment red, rose bengal, aniline blue, ultramarine blue, copper oil blue, methylene chloride blue, phthalocyanine blue, pigment blue, phthalocyanine green, malachite green oxalate, various dyes such as acridine, xanthene, azo, benzoquinone, azine, anthraquinone, thioindigo, dioxazine, thiazine, azomethine, indigo, phthalocyanine, aniline black, polymethine, triphenylmethane, diphenylmethane, thiazole, and the like.

The colorant may be used alone or in combination of two or more.

The colorant may be used as the surface-treated colorant or may be used in combination with a dispersant as required. The colorant may be used in combination of plural kinds.

The content of the colorant is, for example, preferably 1% by mass or more and 30% by mass or less, more preferably 3% by mass or more and 15% by mass or less, relative to the entire toner particle.

Mold release agent-

Examples of the release agent include hydrocarbon waxes; natural waxes such as carnauba wax, rice bran wax, candelilla wax, etc.; synthetic or mineral/petroleum waxes such as montan wax; ester waxes such as fatty acid esters and montan acid esters. The mold release agent is not limited thereto.

The melting temperature of the release agent is preferably 50 ℃ or more and 110 ℃ or less, more preferably 60 ℃ or more and 100 ℃ or less.

The melting temperature was determined from a DSC curve obtained by Differential Scanning Calorimetry (DSC) by "melting peak temperature" described in the method for determining melting temperature of JIS K7121-1987 "method for measuring transition temperature of plastics".

The content of the release agent is, for example, preferably 1% by mass or more and 20% by mass or less, more preferably 5% by mass or more and 15% by mass or less, relative to the entire toner particle.

Other additives-

Examples of the other additives include known additives such as magnetic materials, charge control agents, and inorganic powders. These additives are contained in the toner particles as internal additives.

Relationship of the Components in the toner particles

Difference (SP value (S) -SP value (R))

The difference between the solubility parameter SP value (S) of the specific resin particles and the solubility parameter SP value (R) of the binder resin (SP value (S) -SP value (R)) is preferably-0.32 or more and-0.12 or less.

Since the difference (SP value (S) -SP value (R)) is in the above range, the affinity of the binder resin constituting the majority of the toner particles with the specific resin particles is appropriately maintained, and the specific resin particles are easily dispersed in the toner particles in a nearly uniform state, as compared with the case where the difference is smaller than the above range. Therefore, the toner tends to have near viscoelasticity at high temperature and high strain and low temperature and low strain, and the difference in glossiness condition is reduced. That is, when the affinity of the binder resin to the specific resin particles is too high and the specific resin particles are easy to operate in the toner particles, the specific resin particles partially aggregate and the effect of the specific resin particles is less likely to occur than when the difference (SP value (S) -SP value (R)) is smaller than the above range.

When the difference (SP value (S) -SP value (R)) is within the above range, an increase in melt viscosity of the entire toner due to excessive mixing and compatibility of the specific resin particles and the binder resin at the time of melting the toner can be suppressed as compared with the case where the difference is larger than the above range. This has an advantage that the decrease in fixability due to the excessive viscoelasticity can be suppressed, and good fixability can be obtained.

When the binder resin is a mixed resin, the solubility parameter of the binder resin containing the largest amount of resin is set to the SP value (R).

The difference (SP value (S) -SP value (R)) is more preferably-0.29 or more and-0.18 or less.

The solubility parameter SP value (S) of the specific resin particles is preferably 9.00 to 9.15, more preferably 9.03 to 9.12, and still more preferably 9.06 to 9.10.

Solubility parameter SP value (S) of specific resin particle and solubility parameter SP value (R) of binding resin (unit (cal/cm) ³ ) ^1/2 ) The calculation was performed by the Okitsu method. The Okitsu method is described in detail in Japanese society for bonding, vol.29, no.5 (1993).

Viscoelasticity of the component (excluding the component) from which the specific resin particles are removed

The storage modulus G' in the range of 30 ℃ to 50 ℃ inclusive, from which the components of the specific resin particles are removed from the toner particles, is preferably 1X 10 ⁸ Pa or more, and a storage modulus G' of less than 1×10 ⁵ The temperature Pa is preferably 65 ℃ or higher and 90 ℃ or lower. Hereinafter, the component from which the specific resin particles are removed from the toner particles is also referred to as an "excluded component", and the storage modulus G' is set to less than 1×10 ⁵ The temperature of Pa is also referred to as "specific elastic modulus reaching temperature". The other components than the components having the storage modulus G' satisfying the above conditions have a high elastic modulus at low temperatures, and a low elastic modulus at 65 ℃ or higher and 90 ℃ or lower. Therefore, when the storage modulus G 'of the other components satisfies the above condition, the storage modulus G' becomes less than 1X 10 ⁵ In comparison with the case where the temperature Pa exceeds 90 ℃, the toner particles are easily melted by heating, and the fixability is good.

The storage modulus G' of the other components is preferably 1X 10 at 30 ℃ to 50 ℃ inclusive ⁸ Pa or more, more preferably 1×10 ⁸ Pa or more and 1×10 ⁹ Pa or less, more preferably 2X 10 ⁸ Pa or more and 6×10 ⁸ Pa or below.

Since the storage modulus G' of the other components is 30 ℃ or higher and 50 ℃ or lower in the above range, the storage stability of the toner is good compared with the case of being lower than the above range, and good fixability is easily obtained compared with the case of being higher than the above range.

The specific elastic modulus of the other components is preferably 65℃or more and 90℃or less, more preferably 68℃or more and 80℃or less, and still more preferably 70℃or more and 75℃or less.

Since the specific elastic modulus in the other components reaches the temperature in the above range, the storage stability of the toner is good as compared with the case where the specific elastic modulus is lower than the above range, and good fixability is easily obtained as compared with the case where the specific elastic modulus is higher than the above range.

The specific modulus of elasticity of the other components is preferably 0.8 to 1.6, more preferably 0.9 to 1.5, and even more preferably 1.0 to 1.4.

Since the specific modulus of elasticity of the external component reaches the loss tangent tan δ at temperature in the above range, good fixability is easily obtained as compared with the case where it is lower than the above range. Since the specific modulus of elasticity of the excluded component reaches the loss tangent tan δ at temperature in the above range, the difference in gloss condition is reduced as compared with the case where it is higher than the above range.

The storage modulus G' and loss tangent tan delta of the other components were determined as follows.

Specifically, first, resin particles were removed from toner particles and only the external components were removed, and the external components were molded into tablets at 25 ℃ by a press molding machine, thereby producing a sample for measurement. As a method of removing the resin particles from the toner particles and taking out only the external components, for example, a method of immersing the toner particles in a solvent in which the binder resin is dissolved and the resin particles are not dissolved, and taking out the external components is mentioned.

Then, the obtained measurement sample was sandwiched between parallel plates having a diameter of 8mm, and the measurement temperature was raised from 30℃to 150℃at a rate of 2℃per minute at a strain of 0.1 to 100%, whereby dynamic viscoelasticity was measured under the following conditions. From the respective curves of the storage modulus and loss modulus obtained by the measurement, the storage modulus G' and the loss tangent tan δ were obtained.

Assay conditions-

Measurement device: rheometer ARES-G2 (TA Instruments Co., ltd.)

And (3) measuring a clamp: 8mm parallel plate

Gap: adjusted to 3mm

Frequency: 1Hz

Specific resin particles, toner particles, and relationship between other components

In the range of 90 ℃ to 150 ℃, the storage modulus of the specific resin particles is G '(p 90 to 150), the storage modulus of the toner particles is G' (t 90 to 150), and the storage modulus of the components from which the specific resin particles are removed from the toner particles is G '(r 90 to 150), preferably G' (p 90 to 150) is 1×10 ⁴ Pa or more and 1×10 ⁶ Pa or lower, and preferably a log G '(t 90-150) -log G' (r 90-150) of 1.0 or higher and 4.0 or lower.

The value of log '(t 90-150) -log' (r 90-150) is preferably 1.0 or more and 3.5 or less, more preferably 1.1 or more and 3.4 or less, particularly preferably 1.2 or more and 3.3 or less.

The values of log g '(t 90-150) -log g' (r 90-150) refer to differences in viscoelasticity of the toner particles caused by the presence or absence of the addition of specific resin particles. By dispersing the specific resin particles in a nearly uniform state and incorporating them in the toner particles, the influence of the viscoelasticity of the specific resin particles on the viscoelasticity of the toner particles as a whole is suppressed, and by controlling the values of log g '(t 90-150) -log g' (r 90-150) in the above-described range, both good fixability and reduction in the difference in gloss condition can be achieved as compared with the case where the values are smaller and larger than the above-described range.

Characteristics of toner particles and the like

The toner particles may be toner particles having a single-layer structure, or toner particles having a so-called core/shell structure, which are composed of a core (core particle) and a coating layer (shell layer) coating the core.

The toner particles having a core/shell structure may be constituted by, for example, a core portion containing a binder resin, specific resin particles, and other additives such as a colorant and a release agent as needed, and a coating layer containing a binder resin and specific resin particles.

When the toner particles have a core/shell structure, it is preferable that both the core particles and the shell layer contain specific resin particles. Since both the core particle and the shell layer contain the specific resin particles, the specific resin particles are contained in both the surface region and the center region of the toner particles, and thus the difference in gloss conditions is further reduced.

The volume average diameter (D50 v) of the toner particles is preferably 2 μm or more and 10 μm or less, more preferably 4 μm or more and 8 μm or less, and still more preferably 4 μm or more and 6 μm or less.

The toner particles were measured for various average particle diameters and various particle size distribution indexes using COULTER MULTISIZER II (manufactured by Backman Coulter Co.), and for the electrolyte using ISOTON-II (manufactured by Backman Coulter Co.).

In the measurement, 0.5mg to 50mg of a measurement sample is added as a dispersant to 2ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzenesulfonate). It is added to the electrolyte solution in a volume of 100ml to 150 ml.

The electrolyte in which the sample was suspended was subjected to a dispersion treatment for 1 minute by an ultrasonic disperser, and the particle size distribution of particles having a particle diameter in the range of 2 μm to 60 μm was measured by using COULTER MULTISIZER II and pores having a pore diameter of 100 μm. The sampled number of particles was 50000.

For a particle size range (Channel) divided based on a particle size distribution to be measured, a volume cumulative distribution and a number cumulative distribution are drawn from the small diameter side, respectively, the particle size at which 16% is cumulative is defined as a volume particle size D16v and a number particle size D16p, the particle size at which 50% is cumulative is defined as a volume average particle size D50v and a cumulative number average particle size D50p, and the particle size at which 84% is cumulative is defined as a volume particle size D84v and a number particle size D84p.

They are used (D84 v/D16 v) ^1/2 Calculating a volume particle size distribution index (GSDv) to (D84 p/D16 p) ^1/2 A number particle size distribution index (GSDp) was calculated.

The average circularity of the toner particles is preferably 0.94 or more and 1.00 or less, more preferably 0.95 or more and 0.98 or less.

The average circularity of the toner particles was obtained by (circle equivalent circumference)/(circumference) [ (circumference of circle having the same projection area as the particle image)/(circumference of particle projection image) ]. Specifically, the values were measured by the following methods.

First, toner particles to be measured are sucked and collected to form a flat flow, a particle image is taken as a still image by instantaneous strobe light emission, and an average circularity is determined by a flow type particle image analyzer (FPIA-3000 manufactured by Sysmex Corporation corporation) that performs image analysis on the particle image. The number of samples at the time of obtaining the average roundness is 3500.

When the toner has an external additive, the toner (developer) to be measured is dispersed in water containing a surfactant, and then subjected to ultrasonic treatment, whereby toner particles from which the external additive has been removed are obtained.

(external additive)

Examples of the external additive include inorganic particles. As the inorganic particles, siO may be mentioned ₂ 、TiO ₂ 、Al ₂ O ₃ 、CuO、ZnO、SnO ₂ 、CeO ₂ 、Fe ₂ O ₃ 、MgO、BaO、CaO、K ₂ O、Na ₂ O、ZrO ₂ 、CaO·SiO ₂ 、K ₂ O·(TiO ₂ )n、Al ₂ O ₃ ·2SiO ₂ 、CaCO ₃ 、MgCO ₃ 、BaSO ₄ 、MgSO ₄ Etc.

The surface of the inorganic particles as the external additive may be subjected to hydrophobization. The hydrophobizing treatment is performed, for example, by immersing inorganic particles in a hydrophobizing agent or the like. The hydrophobizing agent is not particularly limited, and examples thereof include silane-based coupling agents, silicone oils, titanate-based coupling agents, aluminum-based coupling agents, and the like. One kind of them may be used alone, or two or more kinds may be used in combination.

The amount of the hydrophobizing agent is usually, for example, 1 part by mass or more and 10 parts by mass or less per 100 parts by mass of the inorganic particles.

Examples of the external additive include resin particles (resin particles such as polystyrene, polymethyl methacrylate (PMMA), and melamine resin), and cleaning active agents (for example, metal salts of higher fatty acids typified by zinc stearate, and particles of fluorine-based high molecular weight bodies).

The external additive amount is, for example, preferably 0.01% by mass or more and 5.0% by mass or less, more preferably 0.01% by mass or more and 2.0% by mass or less, relative to the toner particles.

(Property of toner)

Viscoelasticity of the toner

The toner according to the present embodiment is a specific toner as described above. That is, D1 (90), D50 (90), D1 (150) and D50 (150) are all 0.5 to 2.5, the values of D50 (150) -D1 (150) are less than 1.5, and the values of D50 (90) -D1 (90) are less than 1.0.

D1 (90), D50 (90), D1 (150) and D50 (150) in the specific toner are each 0.5 to 2.5, preferably 0.5 to 2.0, more preferably 0.6 to 1.8, and even more preferably 0.8 to 1.6. Since D1 (90), D50 (90), D1 (150) and D50 (150) are all in the above ranges, good fixability can be obtained as compared with the case where the range is smaller, and the difference in gloss condition is reduced as compared with the case where the range is larger.

The value of D50 (150) -D1 (150) in the specific toner is less than 1.5, preferably 1.2 or less, and more preferably 1.0 or less. Since the values of D50 (150) -D1 (150) are in the above-described range, the difference in gloss condition is reduced as compared with the case where the values are larger than the above-described range. From the viewpoint of reduction in the difference in the glossiness conditions, the smaller the values of D50 (150) -D1 (150) are, the better.

D50 The lower limit value of the values of (150) -D1 (150) is not particularly limited.

The value of D50 (90) -D1 (90) in the specific toner is less than 1.0, preferably less than 0.5, more preferably 0.4 or less, and still more preferably 0.3 or less. Since the values of D50 (90) -D1 (90) are in the above-described range, the difference in gloss condition is reduced as compared with the case where the values are larger than the above-described range. From the viewpoint of reduction in the difference in the glossiness conditions, the smaller the values of D50 (90) -D1 (90) are, the better.

D50 The lower limit of the values of (90) -D1 (90) is not particularly limited.

In the dynamic viscoelasticity measurement of the toner at a temperature rise of 2℃per minute, the storage modulus G' in the range of preferably 30℃to 50℃is 1X 10 ⁸ Pa or more, and storage modulus G' of less than 1×10 ⁵ The temperature of Pa (i.e., the specific elastic modulus reaching temperature) is 65 ℃ or higher and 90 ℃ or lower. The toner having the storage modulus G' satisfying the above conditions has a high elastic modulus at low temperature, and has a low elastic modulus at 65 ℃ or higher and 90 ℃ or lower. Therefore, when the storage modulus G 'of the toner satisfies the above condition, the storage modulus G' becomes lower than 1×10 ⁵ In the case where the temperature Pa exceeds 90 ℃, the toner is easily melted by heating, and the fixing property is good.

The storage modulus G' of the toner is preferably 1X 10 at 30 ℃ or more and 50 ℃ or less ⁸ Pa or more, more preferably 1×10 ⁸ Pa or more and 1×10 ⁹ Pa or less, more preferably 2X 10 ⁸ Pa or more and 6×10 ⁸ Pa or below.

Since the storage modulus G' of the toner is 30 ℃ or higher and 50 ℃ or lower in the above range, the storage stability of the toner is good compared with the case of being lower than the above range, and good fixability is easily obtained compared with the case of being higher than the above range.

The specific elasticity of the toner is preferably 65 ℃ to 90 ℃, more preferably 70 ℃ to 87 ℃, still more preferably 75 ℃ to 84 ℃.

Since the specific elastic modulus in the toner reaches the temperature in the above range, the storage stability of the toner is good as compared with the case where the specific elastic modulus is lower than the above range, and good fixability is easily obtained as compared with the case where the specific elastic modulus is higher than the above range.

The storage modulus G' and specific modulus of elasticity of the toner were obtained as follows.

Specifically, a measurement sample was prepared by molding a toner to be measured into a tablet at room temperature (25 ℃) using a press molding machine. Then, the obtained measurement sample was sandwiched between parallel plates having a diameter of 8mm, and the measurement temperature was raised from 30℃to 150℃at a strain amount of 0.1 to 100℃per minute at 2℃C/min, whereby dynamic viscoelasticity was measured under the following conditions. The storage modulus G' was obtained from each curve of the storage modulus and the loss modulus obtained by the measurement.

Assay conditions-

Measurement device: rheometer ARES-G2 (TA Instruments Co., ltd.)

And (3) measuring a clamp: 8mm parallel plate

Gap: adjusted to 3mm

Frequency: 1Hz

(method for producing toner)

Next, a method for manufacturing the toner according to the present embodiment will be described.

The toner according to the present embodiment is obtained by adding an external additive to the toner particles as necessary after the toner particles are produced.

The toner particles can be produced by any one of a dry process (for example, a kneading and pulverizing process) and a wet process (for example, an aggregation and combination process, a suspension polymerization process, a dissolution and suspension process, and the like). The method for producing toner particles is not limited to these methods, and known methods can be used.

Among them, toner particles can be obtained by an aggregation and coalescence method.

Specifically, for example, in the case of producing toner particles by the aggregation and combination method, toner particles are produced through the following steps:

a step of preparing a resin particle dispersion in which resin particles to be a binder resin are dispersed and a specific resin particle dispersion to be specific resin particles (a resin particle dispersion preparation step); a step (aggregated particle forming step) of forming aggregated particles by aggregating resin particles (other particles, if necessary) in a resin particle dispersion (in a dispersion obtained by mixing other particle dispersions, if necessary); and a step (fusion/combination step) of heating the aggregated particle dispersion liquid in which the aggregated particles are dispersed to fuse/combine the aggregated particles, thereby forming toner particles.

Details of each step will be described below.

In the following description, a method of obtaining toner particles containing a colorant and a release agent is described, but the colorant and the release agent are used as needed. Of course, other additives than colorants and mold release agents may be used.

Preparation of resin particle Dispersion

First, for example, a colorant particle dispersion in which colorant particles are dispersed and a release agent particle dispersion in which release agent particles are dispersed are prepared together with a resin particle dispersion in which resin particles to be a binder resin are dispersed.

The resin particle dispersion liquid is prepared, for example, by dispersing resin particles in a dispersion medium using a surfactant.

Examples of the dispersion medium used for the resin particle dispersion liquid include aqueous media.

Examples of the aqueous medium include distilled water, water such as ion-exchanged water, alcohols, and the like. One kind of them may be used alone, or two or more kinds may be used in combination.

Examples of the surfactant include anionic surfactants such as sulfate salts, sulfonate salts, phosphate esters, and soaps; amine salt type and quaternary ammonium salt type cationic surfactants; nonionic surfactants such as polyethylene glycol-based, alkylphenol-ethylene oxide-based adducts and polyhydric alcohols-based surfactants. Among them, anionic surfactants and cationic surfactants are particularly mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant.

The surfactant may be used alone or in combination of two or more.

Examples of the method for dispersing the resin particles in the dispersion medium in the resin particle dispersion liquid include a rotary shear type homogenizer, a bead MILL having a medium, a sand MILL, and a common dispersing method such as DYNO-MILL. Depending on the type of the resin particles, for example, the resin particles may be dispersed in a resin particle dispersion liquid by using a phase inversion emulsification method.

The phase inversion emulsification method is the following method: the resin to be dispersed is dissolved in a hydrophobic organic solvent in which the resin is soluble, and after neutralization by adding an alkali to an organic continuous phase (O phase), an aqueous medium (W phase) is charged, whereby the resin is converted from W/O to O/W (so-called inversion phase) to be discontinuous, and the resin is dispersed in the form of particles in the aqueous medium.

The volume average particle diameter of the resin particles dispersed in the resin particle dispersion is, for example, preferably 0.01 μm or more and 1 μm or less, more preferably 0.08 μm or more and 0.8 μm or less, and still more preferably 0.1 μm or more and 0.6 μm or less.

As for the volume average particle diameter of the resin particles, a particle size distribution obtained by measurement by a laser diffraction particle size distribution measuring apparatus (for example, manufactured by horiba ltd, LA-700) was used, and for the divided particle size range (Channel), a cumulative distribution was drawn from the small particle diameter side with respect to the volume, and the particle diameter which was 50% of the total particles was measured as a volume average particle diameter D50v. The volume average particle diameter of the particles in the other dispersion was measured in the same manner.

The content of the resin particles contained in the resin particle dispersion is, for example, preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less.

For example, a colorant particle dispersion and a release agent particle dispersion are also prepared in the same manner as the resin particle dispersion. That is, the volume average particle diameter, the dispersion medium, the dispersion method, and the content of the particles in the resin particle dispersion are the same for the colorant particles dispersed in the colorant particle dispersion and the release agent particles dispersed in the release agent particle dispersion.

Preparation of specific resin particle Dispersion

As a method for preparing the specific resin particle dispersion, for example, a known method such as an emulsion polymerization method, a melt kneading method using a banbury mixer or kneader, a suspension polymerization method, or a spray drying method is applied, but an emulsion polymerization method is preferable.

From the viewpoint of setting the storage modulus G' and the loss tangent tan δ of the specific resin particles to the preferred ranges, it is preferable to use a styrene-based monomer and a (meth) acrylic monomer as monomers and to polymerize the monomers in the presence of a crosslinking agent.

In the production of the specific resin particles, it is preferable to perform emulsion polymerization a plurality of times.

Hereinafter, a method for producing specific resin particles will be described in more detail.

The method for producing the specific resin particle dispersion preferably includes:

a step of obtaining an emulsion containing a monomer, a crosslinking agent, a surfactant and water (emulsion preparation step);

a step of adding a polymerization initiator to the emulsion and heating the emulsion to polymerize the monomer (first emulsion polymerization step); and

and a step (second emulsion polymerization step) of adding an emulsion containing a monomer and a crosslinking agent to the reaction solution after the first emulsion polymerization step and heating the emulsion to polymerize the monomer.

Emulsion adjustment procedure

Is a step of obtaining an emulsion containing a monomer, a crosslinking agent, a surfactant and water.

The emulsion is preferably obtained by emulsifying the monomer, the crosslinking agent, the surfactant and water by an emulsifying machine.

Examples of the emulsifying machine include a rotary mixer having propeller-type, anchor-type, paddle-type or turbine-type stirring blades, a static mixer such as a static mixer, a rotor/stator-type emulsifying machine such as a homogenizer or a CERAMIX, a high-pressure emulsifying machine such as a mill-type emulsifying machine having a grinding function, a high-pressure nozzle-type emulsifying machine such as a Manton-Gaulin-type pressure emulsifying machine, a high-pressure collision-type emulsifying machine such as a high-pressure nozzle-type emulsifying machine which generates cavitation (cavitation) at high pressure, a micro-jet machine which applies a shearing force by causing liquids to collide with each other at high pressure, an ultrasonic emulsifying machine which generates cavitation by ultrasonic waves, and a membrane emulsifying machine which uniformly emulsifies through fine pores.

As the monomer, a styrene monomer and a (meth) acrylic monomer are preferably used.

As the crosslinking agent, the above-mentioned crosslinking agents are suitable.

Examples of the surfactant include anionic surfactants such as sulfate salts, sulfonate salts, phosphate esters, and soaps; amine salt type and quaternary ammonium salt type cationic surfactants; nonionic surfactants such as polyethylene glycol-based, alkylphenol-ethylene oxide-based adducts and polyhydric alcohols-based surfactants. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant. Among them, anionic surfactants are preferable. The surfactant may be used alone or in combination of two or more.

The emulsion may also contain a chain transfer agent. The chain transfer agent is not particularly limited, and a compound having a thiol component can be used. Specifically, alkyl thiols such as hexyl thiol, heptyl thiol, octyl thiol, nonyl thiol, decyl thiol, and dodecyl thiol are preferable.

From the viewpoint of setting the storage modulus G' and the loss tangent tan δ of the specific resin particles to the preferred ranges, the mass ratio of the styrene-based monomer and the (meth) acrylic monomer in the emulsion (styrene-based monomer/(meth) acrylic monomer) is preferably 0.2 to 1.1.

The content of the crosslinking agent relative to the entire emulsion is preferably 0.5 mass% or more and 3 mass% or less from the viewpoint of setting the storage modulus G' and the loss tangent tan δ of the specific resin particles to the preferable ranges.

First emulsion polymerization procedure

The step of adding a polymerization initiator to the emulsion and heating the emulsion to polymerize the monomer.

In the polymerization, the emulsion (reaction solution) containing the polymerization initiator is preferably stirred by a stirrer.

Examples of the stirrer include a rotary stirrer having a propeller-type, anchor-type, blade-type, or turbine-type stirring blade.

As the polymerization initiator, ammonium persulfate is preferably used.

When a polymerization initiator is used, the viscoelasticity of the obtained specific resin particles can also be controlled by adjusting the addition amount of the polymerization initiator. For example, by reducing the addition amount of the polymerization initiator, resin particles having a high storage modulus G' can be easily obtained.

Second emulsion polymerization procedure

The step of adding an emulsion containing a monomer to the reaction solution after the first emulsion polymerization step and heating the emulsion to polymerize the monomer.

In the polymerization, the reaction solution is preferably stirred in the same manner as in the first emulsion polymerization step.

In this step, the viscoelasticity of the obtained specific resin particles can also be controlled by adjusting the time taken to add the monomer-containing emulsion. For example, by extending the time taken to add the monomer-containing emulsion, resin particles having a high storage modulus G' can be easily obtained. Examples of the time taken to add the monomer-containing emulsion include a range of 2 hours to 5 hours.

In this step, the viscoelasticity of the obtained specific resin particles can also be controlled by adjusting the temperature at which the reaction solution is stirred. For example, by lowering the temperature at which the reaction solution is stirred, resin particles having a high storage modulus G' can be easily obtained. The temperature at which the reaction solution is stirred may be, for example, 55℃or more and 75℃or less.

For the emulsion containing the monomer, for example, it is preferable to obtain an emulsion by emulsifying the monomer, the surfactant and water by an emulsifying machine.

Agglomerated particle formation step

Next, the colorant particle dispersion liquid, the release agent particle dispersion liquid, and the specific resin particle dispersion liquid are mixed together with the resin particle dispersion liquid.

Then, in the mixed dispersion, the resin particles, the colorant particles, the release agent particles, and the specific resin particles are heterogeneous and aggregated to form aggregated particles containing the resin particles, the colorant particles, the release agent particles, and the specific resin particles, each having a diameter close to the diameter of the target toner particles.

Specifically, for example, an aggregating agent is added to the mixed dispersion, the pH of the mixed dispersion is adjusted to be acidic (for example, pH is 2 or more and 5 or less), and after adding a dispersion stabilizer as needed, the mixed dispersion is heated to a temperature of the glass transition temperature of the resin particles (specifically, for example, the glass transition temperature of the resin particles is-30 ℃ or more and-10 ℃ or less), and the particles dispersed in the mixed dispersion are aggregated to form aggregated particles.

In the agglomerated particle forming step, for example, the above-mentioned agglomerating agent may be added at room temperature (for example, 25 ℃) while stirring the mixed dispersion liquid with a rotary shear type homogenizer, the pH of the mixed dispersion liquid may be adjusted to be acidic (for example, pH is 2 or more and 5 or less), and the above-mentioned heating may be performed after adding the dispersion stabilizer as necessary.

In this step, the dispersion state of the specific resin particles in the obtained toner particles can also be controlled by adjusting the temperature of the mixed dispersion liquid when the coagulant is added. For example, by lowering the temperature of the mixed dispersion, the dispersibility of the specific resin particles becomes good. The temperature of the mixed dispersion liquid may be, for example, 5℃to 40 ℃.

In this step, the dispersion state of the specific resin particles in the obtained toner particles can also be controlled by adjusting the stirring speed after the addition of the coagulant. For example, by increasing the stirring speed after adding the coagulant, the dispersibility of the specific resin particles becomes good.

Examples of the aggregating agent include surfactants used as dispersants to be added to the mixed dispersion liquid, surfactants of opposite polarity, inorganic metal salts, and metal complexes having a valence of 2 or more. In particular, when a metal complex is used as the coagulant, the amount of the surfactant used is reduced, and the charging characteristics are improved.

Additives that form complexes or similar bonds with the metal ions of the agglutinating agent may also be used as desired. As the additive, a chelating agent is preferably used.

Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate, and inorganic metal salt polymers such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide.

As the chelating agent, a water-soluble chelating agent may also be used. Examples of the chelating agent include hydroxycarboxylic acids such as tartaric acid, citric acid, and gluconic acid, iminodiacetic acid (IDA), nitrilotriacetic acid (NTA), and ethylenediamine tetraacetic acid (EDTA).

The amount of the chelating agent to be added is, for example, preferably 0.01 to 5.0 parts by mass, more preferably 0.1 to less than 3.0 parts by mass, based on 100 parts by mass of the resin particles.

Fusion/consolidation procedure

Next, the aggregated particle dispersion liquid in which the aggregated particles are dispersed is heated to, for example, a temperature equal to or higher than the glass transition temperature of the resin particles (for example, a temperature equal to or higher than 10 to 30 ℃ higher than the glass transition temperature of the resin particles), and the aggregated particles are fused and combined to form toner particles.

Through the above steps, toner particles are obtained.

The toner particles may be produced by the following steps: a step of, after obtaining an aggregated particle dispersion in which aggregated particles are dispersed, further mixing the aggregated particle dispersion, a resin particle dispersion in which resin particles are dispersed, and a specific resin particle dispersion in which specific resin particles are dispersed, and performing aggregation to further adhere the resin particles and the specific resin particles to the surfaces of the aggregated particles, thereby forming second aggregated particles; and a step of heating the second aggregated particle dispersion liquid in which the second aggregated particles are dispersed, thereby fusing/combining the second aggregated particles, and forming toner particles having a core/shell structure.

In the step of forming the second aggregated particles, the addition of the resin particle dispersion liquid and the specific resin particle dispersion liquid and the adhesion of the resin particles and the specific resin particles to the surfaces of the aggregated particles may be repeated a plurality of times. By repeating the above steps a plurality of times, toner particles are obtained which uniformly contain specific resin particles in both the surface regions and the central regions of the toner particles.

After the fusion/merging step is completed, the toner particles formed in the solution are subjected to a known cleaning step, solid-liquid separation step, and drying step to obtain dry toner particles.

In the cleaning step, substitution cleaning with ion-exchanged water can be sufficiently performed in view of chargeability. The solid-liquid separation step is not particularly limited, but suction filtration, press filtration, and the like may be performed in view of productivity. The method of the drying step is not particularly limited, and may be freeze-drying, air-drying, flow-drying, vibration-type flow-drying, or the like in terms of productivity.

The toner according to the present embodiment is produced by adding an external additive to the obtained dry toner particles and mixing the resultant particles. The mixing may be performed by, for example, a V-type mixer, a henschel mixer, a rotkoff mixer, or the like. Further, coarse particles of the toner may be removed by using a vibration sieving machine, a wind sieving machine, or the like, as necessary.

< Electrostatic Charge image developer >)

The electrostatic charge image developer according to the present embodiment contains at least the toner according to the present embodiment.

The electrostatic charge image developer according to the present embodiment may be a one-component developer containing only the toner according to the present embodiment, or may be a two-component developer obtained by mixing the toner and a carrier.

The carrier is not particularly limited, and known carriers can be used. Examples of the carrier include a coated carrier in which a surface of a core material made of magnetic powder is coated with a coating resin; a magnetic powder dispersion type carrier in which a magnetic powder is dispersed/blended in a matrix resin; a resin-impregnated carrier in which a resin is impregnated into a porous magnetic powder.

The magnetic powder dispersion type carrier and the resin impregnation type carrier may be a carrier in which constituent particles of the carrier are formed as a core material and coated with a coating resin.

Examples of the magnetic powder include magnetic metals such as iron, nickel, and cobalt, and magnetic oxides such as ferrite and magnetite.

Examples of the coating resin and the matrix resin include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, a vinyl chloride-vinyl acetate copolymer, a styrene-acrylate copolymer, a linear silicone resin containing an organosiloxane bond or a modified product thereof, a fluororesin, a polyester, a polycarbonate, a phenolic resin, and an epoxy resin.

The coating resin and the matrix resin may contain other additives such as conductive particles.

Examples of the conductive particles include particles of metals such as gold, silver, and copper, carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, and potassium titanate.

Examples of the method for coating the surface of the core material with the coating resin include a method in which the core material is coated with a coating layer-forming solution obtained by dissolving the coating resin and various additives, if necessary, in an appropriate solvent. The solvent is not particularly limited, and may be selected in consideration of the coating resin used, coating suitability, and the like.

Specific examples of the resin coating method include a dipping method in which the core material is immersed in a coating layer forming solution, a spraying method in which the coating layer forming solution is sprayed onto the surface of the core material, a fluidized bed method in which the coating layer forming solution is sprayed in a state in which the core material is floated by flowing air, and a kneader coater method in which the core material of the carrier and the coating layer forming solution are mixed in a kneader coater and the solvent is removed.

The mixing ratio (mass ratio) of the toner to the carrier in the two-component developer is preferably toner: carrier=1:100 to 30:100, more preferably 3:100 to 20:100.

Image forming apparatus and image forming method

An image forming apparatus and an image forming method according to the present embodiment will be described.

The image forming apparatus according to the present embodiment includes: an image holding body; a charging unit that charges a surface of the image holder; a static charge image forming unit that forms a static charge image on a surface of the charged image holder; a developing unit that accommodates an electrostatic charge image developer and develops an electrostatic charge image formed on a surface of the image holder into a toner image with the electrostatic charge image developer; a transfer unit that transfers the toner image formed on the surface of the image holder to the surface of the recording medium; and a fixing unit that fixes the toner image that has been transferred to the surface of the recording medium. As the electrostatic charge image developer, the electrostatic charge image developer according to the present embodiment is applied.

In the image forming apparatus according to the present embodiment, an image forming method (image forming method according to the present embodiment) having the following steps is performed: a charging step of charging the surface of the image holder; a static charge image forming step of forming a static charge image on the surface of the charged image holder; a developing step of developing an electrostatic charge image formed on the surface of the image holder into a toner image using the electrostatic charge image developer according to the present embodiment; a transfer step of transferring the toner image formed on the surface of the image holder onto the surface of the recording medium; and a fixing step of fixing the toner image transferred to the surface of the recording medium.

The image forming apparatus according to the present embodiment is applied to a known image forming apparatus such as: a direct transfer system for directly transferring the toner image formed on the surface of the image holder to a recording medium; an intermediate transfer system for primarily transferring the toner image formed on the surface of the image holder onto the surface of the intermediate transfer body, and secondarily transferring the toner image transferred onto the surface of the intermediate transfer body onto the surface of the recording medium; a device including a cleaning unit that cleans a surface of the image holder before charging after transferring the toner image; the device is provided with a charge removing unit which irradiates the surface of the image holder with a charge removing light to remove the charge after the transfer of the toner image and before the charging.

In the case of an intermediate transfer type device, for example, a transfer unit having the following structure is applied: an intermediate transfer body having a toner image transferred onto a surface thereof; a primary transfer unit that primary transfers the toner image formed on the surface of the image holder to the surface of the intermediate transfer body; and a secondary transfer unit that secondarily transfers the toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium.

In the image forming apparatus according to the present embodiment, for example, the portion including the developing unit may be a cartridge structure (process cartridge) that is attached to or detached from the image forming apparatus. As the process cartridge, for example, a process cartridge having a developing unit that accommodates the electrostatic charge image developer according to the present embodiment is preferably used.

Hereinafter, an example of the image forming apparatus according to the present embodiment is shown, but not limited thereto. The main portions shown in the drawings will be described, and the other portions will be omitted.

Fig. 1 is a schematic configuration diagram showing an image forming apparatus according to the present embodiment.

The image forming apparatus shown in fig. 1 includes first to fourth image forming units 10Y, 10M, 10C, and 10K (image forming units) of an electrophotographic system that output yellow (Y), magenta (M), cyan (C), and black (K) images based on color-separated image data. These image forming units (hereinafter, sometimes simply referred to as "units") 10Y, 10M, 10C, 10K are arranged side by side with a predetermined distance therebetween in the horizontal direction. These units 10Y, 10M, 10C, and 10K may be process cartridges that are attached to and detached from the image forming apparatus.

An intermediate transfer belt 20 as an intermediate transfer body is provided to extend through each unit 10Y, 10M, 10C, and 10K above the drawing. The intermediate transfer belt 20 is wound around a driving roller 22 and a supporting roller 24 that are disposed apart from each other in the rightward direction from the left direction in the drawing, and is in contact with the inner surface of the intermediate transfer belt 20, and travels in the direction from the first unit 10Y toward the fourth unit 10K. A force is applied to the backup roller 24 in a direction away from the drive roller 22 by a spring or the like, not shown, so that tension is applied to the intermediate transfer belt 20 wound around both. An intermediate transfer body cleaning device 30 is provided on the image holding body side surface of the intermediate transfer belt 20 so as to face the driving roller 22.

Toners containing toners of four colors of yellow, magenta, cyan, and black contained in the toner cartridges 8Y, 8M, 8C, and 8K are supplied to developing devices (developing units) 4Y, 4M, 4C, and 4K of the respective units 10Y, 10M, 10C, and 10K, respectively.

Since the first to fourth units 10Y, 10M, 10C, and 10K have the same configuration, the first unit 10Y for forming a yellow image, which is disposed upstream in the traveling direction of the intermediate transfer belt, will be described as a representative. The same portions as those of the first unit 10Y are denoted by reference numerals for magenta (M), cyan (C), and black (K) instead of yellow (Y), and the descriptions of the second to fourth units 10M, 10C, and 10K are omitted.

The first unit 10Y has a photoconductor 1Y functioning as an image holder. Around the photoconductor 1Y, there are sequentially arranged: a charging roller (an example of a charging unit) 2Y for charging the surface of the photoconductor 1Y at a predetermined potential, an exposure device (an example of an electrostatic charge image forming unit) 3 for exposing the charged surface with a laser beam 3Y based on a color separation image signal to form an electrostatic charge image, a developing device (an example of a developing unit) 4Y for supplying a charged toner to the electrostatic charge image to develop the electrostatic charge image, a primary transfer roller 5Y (an example of a primary transfer unit) for transferring the developed toner image onto the intermediate transfer belt 20, and a photoconductor cleaning device (an example of a cleaning unit) 6Y for removing the toner remaining on the surface of the photoconductor 1Y after the primary transfer.

The primary transfer roller 5Y is disposed inside the intermediate transfer belt 20 and is disposed at a position facing the photoreceptor 1Y. Further, bias power supplies (not shown) for applying primary transfer biases are connected to the primary transfer rollers 5Y, 5M, 5C, and 5K, respectively. The bias power supplies vary the transfer bias applied to the primary transfer rollers under control of a control unit, not shown.

Hereinafter, an operation of forming a yellow image in the first unit 10Y will be described.

First, before the operation, the surface of the photoreceptor 1Y is charged at a potential of-600V to-800V by the charging roller 2Y.

The photoreceptor 1Y is conductive (for example, volume resistivity at 20 ℃ C.: 1X 10) ^-6 Ω cm or less) is formed by laminating a photosensitive layer on a substrate. The photosensitive layer is generally high in resistance (resistance of a general resin), but has a property that the resistivity of a portion irradiated with the laser beam changes when the laser beam 3Y is irradiated. Accordingly, the laser beam 3Y is output to the surface of the charged photoconductor 1Y via the exposure device 3 based on the image data for yellow transmitted from the control unit, not shown. The laser beam 3Y irradiates the photosensitive layer on the surface of the photosensitive body 1Y, thereby forming an electrostatic charge image of a yellow image pattern on the surface of the photosensitive body 1Y.

The electrostatic charge image is an image formed on the surface of the photoconductor 1Y by charging, and is a so-called negative latent image formed by: the laser beam 3Y reduces the resistivity of the irradiated portion of the photosensitive layer, and charges charged on the surface of the photosensitive body 1Y flow, while charges remain in the portion where the laser beam 3Y is not irradiated.

The electrostatic charge image formed on the photoconductor 1Y rotates to a preset development position as the photoconductor 1Y advances. Then, at this development position, the electrostatic charge image on the photoconductor 1Y is visualized (developed) into a toner image by the developing device 4Y.

An electrostatic charge image developer containing at least yellow toner and a carrier is accommodated in the developing device 4Y, for example. The yellow toner is triboelectrically charged by being stirred inside the developing device 4Y, and is thereby held by a developer roller (an example of a developer holder) with a charge of the same polarity (negative polarity) as the charge charged on the photoconductor 1Y. Further, since the surface of the photoconductor 1Y passes through the developing device 4Y, yellow toner is electrostatically attached to the charge-removed latent image portion on the surface of the photoconductor 1Y, and the latent image is developed by the yellow toner. The photoreceptor 1Y on which the yellow toner image is formed continues to travel at a predetermined speed, and the toner image developed on the photoreceptor 1Y is conveyed to a predetermined primary transfer position.

When the yellow toner image on the photoconductor 1Y is conveyed to the primary transfer position, a primary transfer bias is applied to the primary transfer roller 5Y, and an electrostatic force from the photoconductor 1Y toward the primary transfer roller 5Y acts on the toner image, and the toner image on the photoconductor 1Y is transferred onto the intermediate transfer belt 20. The transfer bias applied at this time is (+) in polarity opposite to the polarity (-) of the toner, and is controlled to +10μa by a control unit (not shown) in the first unit 10Y, for example.

On the other hand, the toner remaining on the photoconductor 1Y is removed and collected by the photoconductor cleaning device 6Y.

The primary transfer biases applied to the primary transfer rollers 5M, 5C, 5K by the second unit 10M and thereafter are also controlled based on the first unit.

In this way, the intermediate transfer belt 20 on which the yellow toner image is transferred in the first unit 10Y is sequentially conveyed by the second to fourth units 10M, 10C, 10K, and the toner images of the respective colors are superimposed and multiply transferred.

The intermediate transfer belt 20, on which the four color toner images are multiply transferred by the first to fourth units, reaches a secondary transfer portion composed of the intermediate transfer belt 20, a backup roller 24 that contacts the inner surface of the intermediate transfer belt, and a secondary transfer roller (an example of a secondary transfer unit) 26 that is disposed on the image holding surface side of the intermediate transfer belt 20. On the other hand, the recording paper (an example of a recording medium) P is supplied to a gap where the secondary transfer roller 26 and the intermediate transfer belt 20 are in contact at a predetermined timing via a supply mechanism, and a secondary transfer bias is applied to the backup roller 24. The transfer bias applied at this time is of the same polarity (-) as the polarity (-) of the toner, and an electrostatic force from the intermediate transfer belt 20 toward the recording paper P acts on the toner image, so that the toner image on the intermediate transfer belt 20 is transferred onto the recording paper P. The secondary transfer bias at this time is determined based on the resistance detected by a resistance detection unit (not shown) that detects the resistance of the secondary transfer portion, and is voltage-controlled.

Thereafter, the recording sheet P is fed to a nip portion (nip portion) of a pair of fixing rollers in a fixing device (an example of a fixing unit) 28, and the toner image is fixed on the recording sheet P to form a fixed image.

The recording paper P on which the toner image is transferred includes, for example, plain paper used in electrophotographic copying machines, printers, and the like. The recording medium includes, in addition to the recording paper P, OHP paper and the like.

In order to further improve the smoothness of the image surface after fixing, the surface of the recording paper P is preferably also smooth, and for example, coated paper obtained by coating the surface of plain paper with a resin or the like, coated paper for printing, or the like is preferably used.

The recording paper P, on which the fixing of the color image is completed, is carried out toward the discharge unit, and a series of color image forming operations is completed.

Process cartridge/toner cartridge

A process cartridge according to the present embodiment will be described.

The process cartridge according to the present embodiment is the following process cartridge: the electrostatic image developing device includes a developing unit that accommodates the electrostatic image developer according to the present embodiment and develops an electrostatic image formed on a surface of an image holder into a toner image using the electrostatic image developer, and the process cartridge is attached to and detached from the image forming apparatus.

The process cartridge according to the present embodiment is not limited to the above-described configuration, and may be configured to include a developing device, and may include at least one member selected from the group consisting of an image holder, a charging unit, an electrostatic charge image forming unit, and a transfer unit, as necessary.

Hereinafter, an example of the process cartridge according to the present embodiment is shown, but the present invention is not limited thereto. The main parts shown in the drawings will be described, and the description thereof will be omitted in other parts.

Fig. 2 is a schematic configuration diagram showing a process cartridge according to the present embodiment.

The process cartridge 200 shown in fig. 2 is configured by integrally combining and holding the photoconductor 107 (an example of an image holder), the charging roller 108 (an example of a charging unit) provided around the photoconductor 107, the developing device 111 (an example of a developing unit), and the photoconductor cleaning device 113 (an example of a cleaning unit) with a frame 117 provided with a mounting rail 116 and an opening 118 for exposure, for example, and is formed in a box shape.

In fig. 2, 109 denotes an exposure device (an example of an electrostatic charge image forming unit), 112 denotes a transfer device (an example of a transfer unit), 115 denotes a fixing device (an example of a fixing unit), and 300 denotes a recording sheet (an example of a recording medium).

Next, a toner cartridge according to the present embodiment will be described.

The toner cartridge according to the present embodiment is a toner cartridge that accommodates the toner according to the present embodiment and is attached to and detached from an image forming apparatus. The toner cartridge accommodates replenishment toner for supply to a developing unit provided in the image forming apparatus.

The image forming apparatus shown in fig. 1 is an image forming apparatus having a structure in which toner cartridges 8Y, 8M, 8C, and 8K are attached and detached, and developing devices 4Y, 4M, 4C, and 4K are connected to toner cartridges corresponding to respective developing devices (colors) through toner supply pipes not shown. When the toner contained in the toner cartridge becomes smaller, the toner cartridge is replaced.

Examples

Hereinafter, examples will be described, but the present invention is not limited to these examples. In the following description, unless otherwise specified, "parts" and "%" are all on a mass basis.

[ preparation of specific resin particle Dispersion and comparative resin particle Dispersion ]

Preparation of specific resin particle Dispersion 1

Styrene: 47.9 parts of

N-butyl acrylate: 51.8 parts of

2-carboxyethyl acrylate: 0.3 part

Anionic surfactant (Dowfax 2A1, manufactured by Dow chemical Co.): 0.8 part

1, 10-decanediol diacrylate: 1.65 parts of

The above raw materials were mixed and dissolved, 60 parts of ion-exchanged water was added thereto, and dispersed and emulsified in a flask to prepare an emulsion.

Then, 1.3 parts of an anionic surfactant (Dowfax 2A1, manufactured by Dow chemical Co., ltd.) was dissolved in 90 parts of ion-exchanged water, 1 part of the emulsion was added thereto, and 10 parts of ion-exchanged water in which 5.4 parts of ammonium persulfate was dissolved was further added thereto.

After that, the remaining amount of the emulsion was charged for 180 minutes, the nitrogen substitution in the flask was performed, and the solution in the flask was heated to 65 ℃ in an oil bath while stirring, and emulsion polymerization was continued in this state for 500 minutes, to obtain a specific resin particle dispersion 1 having a solid content adjusted to 24.5 mass%.

Preparation of specific resin particle Dispersion 2-14, C1-C2 >

The same operations as for the specific resin particle dispersion 1 were conducted except that the amount of styrene added, the amount of n-butyl acrylate added, the amount of acrylic acid added, the amount of 2-carboxyethyl acrylate added, the total amount of anionic surfactant added, the amount of crosslinking agent added, the type of crosslinking agent (type of crosslinking agent in the table), the amount of ammonium peroxide added, the temperature heated in the oil bath (polymerization temperature in the table), the time for adding the balance of the emulsion (addition time in the table) and the time for continuing the emulsion polymerization after heating (holding time in the table) were set as shown in table 1, to obtain specific resin particle dispersions 2 to 14 and C1 to C2.

The number of carbon atoms of the alkylene chain (the number of carbon atoms in the table) in the crosslinking agent to be added is shown in table 1.

TABLE 1

The obtained specific resin particle dispersion and the resin particles contained in the comparative resin particle dispersion were subjected to the above-described method to obtain the minimum values (G '(small) 90 to 150 ℃ in the table) and the maximum values (G' (large) 90 to 150 ℃ in the table), the minimum values (tan δ (small) in the table) and the maximum values (tan δ (S) in the table) of the storage modulus G '(p 90 to 150 ℃ in the table) in the range of 90 to 150 ℃, the loss tangent tan δ in the range of 30 to 150 ℃, the loss tangent tan δ in the table in the range of 65 to 150 ℃, the storage modulus G' (p 90 to 150 ℃ in the table), the loss tangent tan δ in the range of 65 to 150 ℃ in the table, and the SP value, and the results thereof are shown in table 2.

TABLE 2

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Preparation of amorphous resin particle Dispersion 1

Terephthalic acid: 28 parts of

Fumaric acid: 164 parts

Adipic acid: 10 parts of

Bisphenol a ethylene oxide 2 molar adduct: 26 parts of

Bisphenol a propylene oxide 2 molar adduct: 542 parts of

The above material was charged into a reaction vessel equipped with a stirring device, a nitrogen inlet, a temperature sensor and a rectifying column, and the temperature was raised to 190℃over 1 hour, and 1.2 parts of dibutyltin oxide was charged into 100 parts of the above material. The reaction mixture was cooled after the dehydration condensation reaction was continued for 3 hours by raising the temperature to 240℃over 6 hours while removing the water produced by distillation, and maintaining the temperature at 240 ℃.

The reaction mixture was transferred to Cavitron CD1010 (manufactured by EUROTEC Co.) at a rate of 100 g/min in a molten state. Simultaneously, ammonia water having a concentration of 0.37 mass% was prepared separately and transferred to Cavitro CD1010 at a rate of 0.1 liter per minute while being heated to 120℃by a heat exchanger. At a rotor speed of 60Hz and a pressure of 5kg/cm ² Is a strip of (2)Cavitro CD1010 was run under the same conditions to obtain a resin particle dispersion in which resin particles of an amorphous polyester resin having a volume average particle diameter of 169nm were dispersed. Ion-exchanged water was added to the resin particle dispersion to adjust the solid content to 20 mass%, and the resultant was used as the amorphous resin particle dispersion 1.

The SP value (R) of the obtained amorphous polyester resin was 9.41.

Preparation of amorphous resin particle Dispersion 2

Styrene: 72 parts of

N-butyl acrylate: 27 parts of

2-carboxyethyl acrylate: 1.3 parts of

Dodecyl mercaptan: 2 parts of

In a flask, a mixture of the above materials was mixed and dissolved, and 1.2 parts by mass of an anionic surfactant (TAYCA power, manufactured by TAYCA corporation) was dispersed and emulsified in 100 parts by mass of ion-exchanged water. Then, an aqueous solution prepared by dissolving 6 parts by mass of ammonium persulfate in 50 parts by mass of ion-exchange water was charged for 20 minutes while stirring the flask. Next, after nitrogen substitution, the contents were heated to 75 ℃ in an oil bath while stirring the flask, and emulsion polymerization was continued for 4 hours at 75 ℃. Thus, a resin particle dispersion in which resin particles of an amorphous styrene acrylic resin having a volume average particle diameter of 160nm and a weight average molecular weight of 56000 were dispersed was obtained. Ion-exchanged water was added to the resin particle dispersion to adjust the solid content to 31.4 mass%, and the resultant was used as the amorphous resin particle dispersion 2.

The SP value (R) of the obtained amorphous styrene acrylic resin was 9.14.

Preparation of amorphous resin particle Dispersion 3

Terephthalic acid: 28 parts of

Fumaric acid: 174 parts of

Bisphenol a ethylene oxide 2 molar adduct: 26 parts of

Bisphenol a propylene oxide 2 molar adduct: 542 parts of

The above material was charged into a reaction vessel equipped with a stirring device, a nitrogen inlet, a temperature sensor and a rectifying column, and the temperature was raised to 190℃over 1 hour, and 1.2 parts of dibutyltin oxide was charged into 100 parts of the above material. The water produced was distilled off for 6 hours while the temperature was raised to 240℃and the dehydration condensation reaction was continued for 3 hours while maintaining 240℃and then the reaction product was cooled.

The reaction product was transferred to Cavitro CD1010 (manufactured by EUROTEC Co.) in a molten state at a rate of 100 g/min. Simultaneously, ammonia water having a concentration of 0.37 mass% was prepared separately and transferred to Cavitro CD1010 at a rate of 0.1 liter per minute while being heated to 120℃by a heat exchanger. At a rotor speed of 60Hz and a pressure of 5kg/cm ² Cavitro CD1010 was run under the conditions of (2) to obtain a resin particle dispersion in which resin particles of an amorphous polyester resin having a volume average diameter of 175nm were dispersed. Ion-exchanged water was added to the resin particle dispersion to adjust the solid content to 20 mass%, and the resultant was used as the amorphous resin particle dispersion 3.

The SP value (R) of the obtained amorphous polyester resin was 9.43.

Preparation of crystalline resin particle Dispersion

1, 10-dodecanedioic acid: 225 parts

1, 6-hexanediol: 143 parts of

The above materials were charged into a reaction vessel equipped with a stirring device, a nitrogen inlet tube, a temperature sensor and a rectifying column, and the temperature was raised to 160℃over 1 hour, followed by charging 0.8 part by mass of dibutyltin oxide. The dehydration condensation reaction was continued for 5 hours by raising the temperature to 180℃and maintaining 180℃over 6 hours while removing the water produced by distillation. Thereafter, the temperature was gradually raised to 230℃under reduced pressure, and 230℃was maintained and stirred for 2 hours. Thereafter, the reactants were cooled. After cooling, solid-liquid separation is performed, and the solid is dried to obtain a crystalline polyester resin.

Crystalline polyester resin: 100 parts of

Methyl ethyl ketone: 40 parts of

Isopropyl alcohol: 30 parts of

10% ammonia solution: 6 parts of

The above materials were added to a jacketed 3-liter reaction vessel (BJ-30N, manufactured by Tokyo physical and chemical instruments Co., ltd.) equipped with a condenser, a thermometer, a water dropping device, and an anchor wing, and the mixture was stirred and mixed at 100rpm while maintaining the temperature at 80℃in a water circulation type constant temperature vessel, to dissolve the resin. Then, the water circulation type thermostat was set to 50 ℃, 400 parts were added dropwise to ion-exchanged water kept at 50 ℃ at a rate of 7 parts by mass/min and phase-inverted, thereby obtaining an emulsion. 576 parts by mass of the obtained emulsion and 500 parts by mass of ion-exchanged water were placed in a 2 liter eggplant-shaped flask, and the mixture was placed in an evaporator (manufactured by tokyo physical and chemical instruments) equipped with a vacuum control unit via Trap balls (Trap ball). While heating the eggplant-shaped flask in a hot water bath at 60℃while rotating the flask, the flask was depressurized to 7kPa while taking care of the bumping, and the solvent was removed. The volume average particle diameter D50v of the resin particles in the dispersion was 185nm. Then, ion-exchanged water was added to obtain a crystalline resin particle dispersion having a solid content concentration of 22.1 mass%.

< preparation of colorant Dispersion >

Cyan pigment (PicementBuue 15:3 (copper phthalocyanine) manufactured by Dairy Co., ltd.): 98 parts of

Anionic surfactant (TaycaPower, manufactured by Imperial chemical Co., ltd.): 2 parts of

Ion-exchanged water: 420 parts

The above materials were mixed and dissolved, and dispersed for 10 minutes by a homogenizer (IKA ULTRA TURRAX) to obtain a colorant dispersion having a center particle diameter of 164nm and a solid content of 21.1 mass%.

< preparation of Release agent Dispersion >

Synthetic wax (manufactured by Nippon refined wax Co., ltd., FNP92, melting temperature Tw:92 ℃ C.): 50 parts of

Anionic surfactant (TaycaPower, manufactured by Imperial chemical Co., ltd.): 1 part of

Ion-exchanged water: 200 parts of

The above materials were mixed and heated to 130℃and dispersed by a homogenizer (ULTRA TURRAXT50, manufactured by IKA Co., ltd.) and then subjected to a dispersion treatment by a Manton Gaulin high-pressure homogenizer (manufactured by Gaulin Co., ltd.) to obtain a release agent dispersion (solid content: 20% by mass) in which release agent particles were dispersed. The volume average diameter of the release agent particles was 214nm.

Example 1 >

Amorphous resin particle dispersion 1:169 parts of

Specific resin particle dispersion 1:33 parts of

Crystalline resin particle dispersion: 53 parts

Mold release agent dispersion: 25 parts of

Colorant dispersion: 33 parts of

Anionic surfactant (Dowfax 2A1, manufactured by Dow chemical Co.): 4.8 parts of

The above raw materials having a liquid temperature of 10℃were placed in a 3L cylindrical stainless steel vessel, and dispersed and mixed for 2 minutes by applying a shearing force at 4000rpm by a homogenizer (ULTRA TURRAX T50, manufactured by IKA Co.).

Then, 1.75 parts of a 10% aqueous nitric acid solution of aluminum sulfate was slowly dropped as a coagulant, and the mixture was dispersed and mixed for 10 minutes at 10000rpm as a raw material dispersion.

Thereafter, the raw material dispersion was transferred to a polymerization reactor equipped with a stirring device using stirring blades of two paddles and a thermometer, and the stirring speed was set to 550rpm, and heating was started in a heating pack, thereby promoting the growth of agglomerated particles at 40 ℃. At this time, the pH of the raw material dispersion was controlled to be in the range of 2.2 to 3.5 with 0.3M nitric acid and 1M aqueous sodium hydroxide solution. The above pH range was maintained for about 2 hours to form agglomerated particles.

Subsequently, the amorphous resin particle dispersion liquid 1 was additionally added: 21 parts and specific resin particle dispersion 1:8 parts of the mixed dispersion was kept for 60 minutes, and resin particles of the binder resin and specific resin particles were adhered to the surfaces of the aggregated particles. Further, the temperature was raised to 53 ℃, and then, amorphous resin particle dispersion liquid 1 was additionally added: 21 parts and left for 60 minutes, and resin particles of the binder resin were attached to the surfaces of the agglomerated particles.

The agglomerated particles were aligned while confirming the size and morphology of the particles by an optical microscope and a particle/cell count and particle size analyzer (Multisizer) 3. Then, the pH was adjusted to 7.8 using 5% aqueous sodium hydroxide solution and maintained for 15 minutes.

Then, in order to fuse the aggregated particles, the pH was raised to 8.0, and then the temperature was raised to 85 ℃. After confirming fusion of the agglomerated particles by an optical microscope, heating was stopped after 2 hours, and cooling was performed at a cooling rate of 1.0 ℃/min. Then, the resultant was sieved through a 20 μm sieve, washed with water repeatedly, and dried by a vacuum dryer to obtain toner particles 1 having a volume average particle diameter of 5.3. Mu.m.

100 parts of the obtained toner particles and 0.7 part of dimethylsilicone-treated silica particles (RY 200 manufactured by AEROSIL Co., japan) were mixed by a Henschel mixer to obtain toner 1.

Examples 2 to 11, examples 29 to 32 and comparative examples C1 to C2 >, respectively

Toners 2 to 11, toners 29 to 32, and toners C1 to C2 were obtained in the same manner as in toner 1 except that the specific resin particle dispersion liquid or comparative resin particle dispersion liquid of the type shown in Table 3 was used in place of the specific resin particle dispersion liquid 1 in an amount such that the content ratio of the resin particles (i.e., the specific resin particles or comparative resin particles) relative to the entire toner particles became the values shown in Table 3.

Example 12 >

Toner 12 was obtained in the same manner as toner 1 except that specific resin particle dispersion 1 was used in such an amount that the content of the specific resin particles relative to the whole toner particles was the value shown in table 3, and the addition amount of the crystalline resin particle dispersion was adjusted so that the content of the crystalline resin relative to the whole binder resin was the value shown in table 3.

Example 13 >

Toner 13 was obtained in the same manner as toner 1 except that the addition amount of the crystalline resin particle dispersion was adjusted so that the content of the crystalline resin relative to the whole binder resin became the values shown in table 3.

Example 14 >

Toner 14 was obtained in the same manner as toner 1 except that the specific resin particle dispersion liquid or comparative resin particle dispersion liquid of the type shown in table 3 was used instead of specific resin particle dispersion liquid 1 in an amount such that the content of the resin particles (i.e., specific resin particles or comparative resin particles) relative to the entire toner particles became the values shown in table 3, and crystalline resin particle dispersion liquid was not added.

Example 15 and 28 >

Toners 15 and 28 were obtained in the same manner as in toner 1 except that the amorphous resin particle dispersion liquid of the type shown in table 3 was used in the amount shown in table 3 instead of using amorphous resin particle dispersion liquid 1.

Example 16 >

Toner 16 was obtained in the same manner as in toner 1 except that the rotational speed of the homogenizer was changed from 10000rpm to 5000 rpm.

Example 17 >

Toner 17 was obtained in the same manner as toner 1 except that the addition amount of the crystalline resin particle dispersion was adjusted so that the content of the crystalline resin relative to the whole binder resin became the values shown in table 3.

Example 18 >

Toner 18 was obtained in the same manner as toner 1 except that specific resin particle dispersion 1 was used in such an amount that the content of the specific resin particles relative to the whole toner particles was the value shown in table 3, and the addition amount of the crystalline resin particle dispersion was adjusted so that the content of the crystalline resin relative to the whole binder resin was the value shown in table 3.

Example 19 >

Toner 19 was obtained in the same manner as toner 1 except that the pH at the fusion of the aggregated particles was changed from 8.0 to 9.0.

Example 20 >

Toner 20 was obtained in the same manner as toner 1 except that the pH at the fusion of the aggregated particles was changed from 8.0 to 5.5.

Example 21 >

Toner 21 was obtained in the same manner as toner 1 except that specific resin particle dispersion 1 was used in an amount such that the content of the specific resin particles relative to the whole toner particles became the values shown in table 3, and the pH at the time of fusion of the aggregated particles was changed from 8.0 to 9.5.

Example 22 >

Toner 22 was obtained in the same manner as in toner 1 except that specific resin particle dispersion 1 was used in an amount such that the content of the specific resin particles relative to the whole toner particles became the value shown in table 3, the amount of specific resin particles 1 was changed from 10 to 19, and the pH at the time of fusion of the aggregated particles was changed from 8.0 to 6.0.

Examples 23 to 27 >

Toners 23 to 27 were obtained in the same manner as in toner 1 except that the specific resin particle dispersion liquid of the type shown in table 3 was used instead of the specific resin particle dispersion liquid 1 in such an amount that the content of the specific resin particles relative to the whole toner particles became the value shown in table 3, and the addition amount of the crystalline resin particle dispersion liquid was adjusted so that the content of the crystalline resin relative to the whole binder resin became the value shown in table 3.

Comparative example C3 >

Amorphous resin particle dispersion 1:169 parts of

Specific resin particle dispersion 1:33 parts of

Crystalline resin particle dispersion: 53 parts

Mold release agent dispersion: 25 parts of

Colorant dispersion: 33 parts of

Anionic surfactant (Dowfax 2A1, manufactured by Dow chemical Co.): 4.8 parts of

The above raw materials having a liquid temperature of 30℃were placed in a 3L cylindrical stainless steel vessel, and dispersed and mixed for 2 minutes by applying a shearing force at 4000rpm by a homogenizer (ULTRA TURRAX T50, manufactured by IKA Co.).

Then, 1.75 parts of a 10% aqueous nitric acid solution of aluminum sulfate was slowly dropped as a coagulant, and the mixture was dispersed and mixed for 3 minutes at 4000rpm to obtain a raw material dispersion.

Then, the raw material dispersion was transferred to a polymerization reactor equipped with a stirring device using stirring blades of two paddles and a thermometer, and the stirring speed was set to 550rpm, and heating was started in a heating pack, thereby promoting the growth of agglomerated particles at 40 ℃. At this time, the pH of the raw material dispersion was controlled to be in the range of 2.2 to 3.5 with 0.3M nitric acid and 1M aqueous sodium hydroxide solution. The above pH range was maintained for about 2 hours to form agglomerated particles.

Subsequently, the amorphous resin particle dispersion liquid 1 was additionally added: 21 parts and specific resin particle dispersion 1:8 parts of the mixed dispersion was kept for 60 minutes, and resin particles of the binder resin and specific resin particles were adhered to the surfaces of the aggregated particles. Further, the temperature was raised to 53 ℃, and then, the amorphous resin particle dispersion was additionally added: 21 parts, holding for 60 minutes, and adhering resin particles of the binder resin to the surface of the agglomerated particles.

The agglomerated particles were aligned while confirming the size and shape of the particles by an optical microscope and a particle/cell count and particle size analyzer 3. Then, the pH was adjusted to 7.8 using 5% aqueous sodium hydroxide solution and maintained for 15 minutes.

Then, in order to fuse the aggregated particles, the pH was raised to 8.0, and then the temperature was raised to 85 ℃. After confirming fusion of the agglomerated particles by an optical microscope, heating was stopped after 2 hours, and cooling was performed at a cooling rate of 1.0 ℃/min. Then, the resultant was sieved through a 20 μm sieve, washed with water repeatedly, and dried by a vacuum dryer to obtain toner particles C3.

100 parts of the obtained toner particles and 0.7 part of dimethylsilicone-treated silica particles (RY 200 manufactured by AEROSIL Co., japan) were mixed by a Henschel mixer to obtain toner C3.

Comparative example C4 >

Amorphous resin particle dispersion 1:169 parts of

Specific resin particle dispersion 1:41 parts of

Crystalline resin particle dispersion: 53 parts

Mold release agent dispersion: 25 parts of

Colorant dispersion: 33 parts of

Anionic surfactant (Dowfax 2A1, manufactured by Dow chemical Co.): 4.8 parts of

Next, amorphous resin particle dispersion 1 was additionally added: 42 parts and holding for 60 minutes, and the resin particles of the binder resin were adhered to the surfaces of the agglomerated particles.

Then, in order to fuse the aggregated particles, the pH was raised to 8.0, and then the temperature was raised to 85 ℃. After confirming fusion of the agglomerated particles by an optical microscope, heating was stopped after 2 hours, and cooling was performed at a cooling rate of 1.0 ℃/min. Then, the resultant was sieved through a 20 μm sieve, washed with water repeatedly, and dried by a vacuum dryer to obtain toner particles C4.

100 parts of the obtained toner particles and 0.7 part of dimethylsilicone-treated silica particles (RY 200 manufactured by AEROSIL Co., japan) were mixed by a Henschel mixer to obtain toner C4.

Comparative example C5 >

Amorphous resin particle dispersion 1:169 parts of

Crystalline resin particle dispersion: 53 parts

Mold release agent dispersion: 25 parts of

Colorant dispersion: 33 parts of

Anionic surfactant (Dowfax 2A1, manufactured by Dow chemical Co.): 4.8 parts of

Next, the mixed amorphous resin particle dispersion liquid 1:42 parts and specific resin particle dispersion 1: the 41 parts of the dispersion was divided into half parts, added in two portions, and held for 60 minutes to attach the resin particles of the binder resin and the specific resin particles to the surfaces of the aggregated particles.

Then, in order to fuse the aggregated particles, the pH was raised to 8.0, and then the temperature was raised to 85 ℃. After confirming fusion of the agglomerated particles by an optical microscope, heating was stopped after 2 hours, and cooling was performed at a cooling rate of 1.0 ℃/min. Then, the resultant was sieved through a 20 μm sieve, washed with water repeatedly, and dried by a vacuum dryer to obtain toner particles C5.

100 parts of the obtained toner particles and 0.7 part of dimethylsilicone-treated silica particles (RY 200 manufactured by AEROSIL Co., japan) were mixed by a Henschel mixer to obtain toner C5.

Comparative example C6 >

Toner C6 was obtained in the same manner as toner 1 except that the specific resin particle dispersion liquid 1 was not added.

Comparative example C7 >

Toner C7 was obtained in the same manner as in toner 1 except that the pH at the time of fusion of the aggregated particles was changed from 8.0 to 6.5, the temperature after the temperature rise was changed from 85 ℃ to 75 ℃, and 5.2 parts of an anionic surfactant (Dowfax 2A1, manufactured by dow chemical company) was added when the temperature reached 75 ℃.

Comparative example C8 >

Toner C8 was obtained in the same manner as in toner 1 except that the pH at the fusion of the aggregated particles was changed from 8.0 to 10.0 and the temperature after the temperature rise was changed from 85 ℃ to 95 ℃.

Table 3 shows the types of the specific resin particle dispersion liquid or the comparative resin particle dispersion liquid (the "particle types" in the table), the content of the specific resin particle or the comparative resin particle relative to the whole toner particle (the "particle content (%)" in the table), the content of the crystalline resin relative to the whole binder resin (the "crystalline resin content (%)" in the table), and the types of the amorphous resin particle dispersion liquid (the "amorphous resin types" in the table).

The ratio of the content of the crystalline resin to the content of the specific resin particles (the "crystalline content ratio vs particles" in the table) and the ratio of the content of the amorphous resin to the content of the specific resin particles (the "amorphous content ratio vs particles" in the table) in the obtained toner are shown in table 3 together.

The volume average particle diameters of the toner particles in the obtained toners are shown in table 3.

The storage modulus G '(in the table, "30 to 50 ℃ G' (Pa)") in the range of 30 ℃ to 50 ℃ inclusive of the excluded components, the specific elastic modulus reaching temperature (in the table, "reaching temperature (°c)") of the excluded components, and the loss tangent tan δ (in the table, "reaching temperature tan δ") at the specific elastic modulus reaching temperature were obtained by the above-described methods, and the results are shown together in tables 4 to 5.

The values of D1 (90), D50 (90), D1 (150), D50 (150) and D50 (150) -D1 (150) (the "difference (150)" in the table), the values of D50 (90) -D1 (90) (the "difference (90)" in the table), the number average molecular weight of THF-soluble components in the toner particles (Mn in the table), the storage modulus G '(the "30-50G' (Pa)" in the table) in the range of 30 ℃ to 50 ℃ and the specific elastic modulus reaching the temperature (the "reaching temperature (°c)" in the table), the values of log G '(t 90-150) -log G' (R90-150) (the "viscoelastic difference" in the table) and the difference (SP value (S) -SP value (R)) (the "SP value difference" in the table) were obtained by the above-described methods, and the results thereof are shown together in tables 4 to 5.

[ production of developer ]

The resulting toner 8 parts and the following carrier 100 parts were mixed to obtain a developer.

Preparation of the support

The above-mentioned components except ferrite particles were dispersed by a sand mill to prepare a dispersion, and the dispersion was put into a vacuum degassing kneader together with ferrite particles, and dried under reduced pressure while stirring, to obtain a carrier.

[ evaluation ]

< gloss Difference >

The obtained developer was charged in a developer of a color copier apeosPortIV C3370 (manufactured by Fuji film Co., ltd.) from which the fixer was taken out, so that the toner carrying amount became 0.45mg/cm ² Is adjusted and an unfixed image is output. Commercial use of Fuji film as recording mediumThe OS coated W paper manufactured by Innovative corporation was A4 size (basis weight 127 gsm). The output image is an image of 50mm x 50mm size with an image density of 100%.

As the fixing evaluation device, a device was used in which a fixing device of apeosoPort IV C3370 manufactured by Fuji film commercial innovations (ltd.) was removed and modified so that the nip pressure and fixing temperature could be changed. The treatment speed was 175mm/sec.

Under such conditions, the unfixed image was subjected to low temperature and low pressure conditions (specifically, the temperature of the fixing device was 120 ℃ C., the nip pressure was 1.6kgf/cm ² ) And under high temperature and high pressure conditions (specifically, the temperature of the fixer is 180 ℃ C., the nip pressure is 6.0 kgf/cm) ² ) Fixing is performed under these two conditions to obtain a fixed image. The glossiness of the fixed image portion was measured by 60 ° gross using a glossmeter micro-tri-gross manufactured by BYK corporation, and the difference in glossiness (i.e., difference in glossiness condition) of the fixed image under low-temperature low-pressure conditions and the fixed image under high-temperature high-pressure conditions was found. The results are shown in tables 4 to 5.

When the difference in glossiness is less than 5, the difference in glossiness is less than 5 and less than 10, and when the difference in glossiness is 10 or more and less than 15, the difference in glossiness is not less than 15, and when the difference in glossiness is not less than 15, the difference in glossiness is large and outside the allowable range, although the difference in glossiness is slightly recognizable.

< fixing Property >

For a fixed image under low temperature and low pressure conditions in the evaluation of the difference in glossiness, bending was performed using a weight, and the image quality was evaluated based on the degree of image defect in the portion. The evaluation criteria are shown in tables 4 to 5.

G1: no image defects were observed at all

And G2: image defects were observed, but very slight

And G3: image defects were slightly observed, but within the allowable range

And G4: image defects were observed

TABLE 3

TABLE 4

TABLE 5

From the above results, it is understood that the toner of the present embodiment can obtain good fixability, and the difference in glossiness between the fixed image under low-temperature low-pressure conditions and the fixed image under high-temperature high-pressure conditions is small.

The present application claims priority based on japanese patent applications 2021-157169 at 9 months of 2021 and japanese patent application 2022-145659 at 9 months of 2022.

Claims

1. A toner for developing an electrostatic charge image, comprising toner particles containing a binder resin, wherein,

d50 The values of (150) -D1 (150) are less than 1.5,

d50 The value of (90) -D1 (90) is less than 1.0,

the toner particles further contain resin particles,

2. The toner for developing an electrostatic charge image according to claim 1, wherein,

3. The toner for developing an electrostatic charge image according to claim 1, wherein,

4. The toner for developing an electrostatic charge image according to claim 1,

the number average particle diameter of the resin particles is 60nm to 300 nm.

5. The toner for developing an electrostatic charge image according to claim 1, wherein,

6. The toner for developing an electrostatic charge image according to claim 1, wherein,

the resin particles are crosslinked resin particles.

7. The toner for developing an electrostatic charge image according to claim 6, wherein,

the crosslinked resin particles are styrene (meth) acrylic resin particles.

8. The toner for developing an electrostatic charge image according to claim 1, wherein,

9. The toner for developing an electrostatic charge image according to claim 1, wherein,

10. The toner for developing an electrostatic charge image according to claim 9, wherein,

11. The toner for developing an electrostatic charge image according to claim 1, wherein,

in the dynamic viscoelasticity measurement at a temperature rise of 2 ℃/min, when the storage modulus of the resin particles in the range of 90 ℃ to 150 ℃ is G ' (p 90-150), the storage modulus of the toner particles is G ' (t 90-150), and the storage modulus of the components from which the resin particles are removed from the toner particles is G ' (r 90-150),

1×10 ⁴ Pa≤G’(p90-150)≤1×10 ⁶ Pa, and

1.0≤logG’(t90-150)-logG’(r90-150)≤4.0。

12. the toner for developing an electrostatic charge image according to claim 1, wherein,

13. The toner for developing an electrostatic charge image according to claim 1, wherein,

the binder resin contains a crystalline resin and,

14. The toner for developing an electrostatic charge image according to claim 1, wherein,

the binder resin contains a polyester resin.

15. The toner for developing an electrostatic charge image according to claim 14, wherein,

16. The toner for developing an electrostatic charge image according to claim 1, wherein,

17. The toner for developing an electrostatic charge image according to claim 1, wherein,

the glass transition temperature Tg of the resin particles, which is determined by dynamic viscoelasticity measurement, is 10 ℃ or higher and 45 ℃ or lower,

in the dynamic viscoelasticity measurement of the resin particles at a temperature rise of 2 ℃/min, the loss tangent tan delta in the range of 30 ℃ to 150 ℃ is 0.01 to 2.5,

the resin particles are cross-linked resin particles,

in the dynamic viscoelasticity measurement of the toner for developing electrostatic charge image at a temperature rise of 2 ℃/min, the storage modulus G' is 1×10 in a range of 30 ℃ to 50 ℃ inclusive ⁸ Pa or more, and storage modulus G'Up to less than 1X 10 ⁵ Pa is 65 ℃ to 90 ℃.

18. The toner for developing an electrostatic charge image according to claim 1, wherein,

the resin particles are cross-linked resin particles,

The crosslinked resin particles are styrene (meth) acrylic resin particles,

19. An electrostatic charge image developer comprising the toner for electrostatic charge image development according to any one of claims 1 to 18.

20. A toner cartridge containing the toner for developing an electrostatic charge image according to any one of claim 1 to claim 18,

21. A process cartridge comprising a developing unit that accommodates the electrostatic charge image developer according to claim 19 and develops an electrostatic charge image formed on a surface of an image holder into a toner image using the electrostatic charge image developer,

22. An image forming apparatus includes:

an image holding body;

a charging unit that charges a surface of the image holding body;

A developing unit that accommodates the electrostatic charge image developer according to claim 19 and develops an electrostatic charge image formed on a surface of the image holder into a toner image with the electrostatic charge image developer;

23. An image forming method, comprising:

a charging step of charging the surface of the image holder;

a developing step of developing an electrostatic charge image formed on a surface of the image holder into a toner image using the electrostatic charge image developer according to claim 19;